xref: /openbmc/linux/fs/ext4/super.c (revision 8730046c)
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/slab.h>
25 #include <linux/init.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.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/ctype.h>
38 #include <linux/log2.h>
39 #include <linux/crc16.h>
40 #include <linux/cleancache.h>
41 #include <linux/uaccess.h>
42 
43 #include <linux/kthread.h>
44 #include <linux/freezer.h>
45 
46 #include "ext4.h"
47 #include "ext4_extents.h"	/* Needed for trace points definition */
48 #include "ext4_jbd2.h"
49 #include "xattr.h"
50 #include "acl.h"
51 #include "mballoc.h"
52 
53 #define CREATE_TRACE_POINTS
54 #include <trace/events/ext4.h>
55 
56 static struct ext4_lazy_init *ext4_li_info;
57 static struct mutex ext4_li_mtx;
58 static struct ratelimit_state ext4_mount_msg_ratelimit;
59 
60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
61 			     unsigned long journal_devnum);
62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
63 static int ext4_commit_super(struct super_block *sb, int sync);
64 static void ext4_mark_recovery_complete(struct super_block *sb,
65 					struct ext4_super_block *es);
66 static void ext4_clear_journal_err(struct super_block *sb,
67 				   struct ext4_super_block *es);
68 static int ext4_sync_fs(struct super_block *sb, int wait);
69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
71 static int ext4_unfreeze(struct super_block *sb);
72 static int ext4_freeze(struct super_block *sb);
73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
74 		       const char *dev_name, void *data);
75 static inline int ext2_feature_set_ok(struct super_block *sb);
76 static inline int ext3_feature_set_ok(struct super_block *sb);
77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
78 static void ext4_destroy_lazyinit_thread(void);
79 static void ext4_unregister_li_request(struct super_block *sb);
80 static void ext4_clear_request_list(void);
81 static struct inode *ext4_get_journal_inode(struct super_block *sb,
82 					    unsigned int journal_inum);
83 
84 /*
85  * Lock ordering
86  *
87  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
88  * i_mmap_rwsem (inode->i_mmap_rwsem)!
89  *
90  * page fault path:
91  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
92  *   page lock -> i_data_sem (rw)
93  *
94  * buffered write path:
95  * sb_start_write -> i_mutex -> mmap_sem
96  * sb_start_write -> i_mutex -> transaction start -> page lock ->
97  *   i_data_sem (rw)
98  *
99  * truncate:
100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
101  *   i_mmap_rwsem (w) -> page lock
102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
103  *   transaction start -> i_data_sem (rw)
104  *
105  * direct IO:
106  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
107  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
108  *   transaction start -> i_data_sem (rw)
109  *
110  * writepages:
111  * transaction start -> page lock(s) -> i_data_sem (rw)
112  */
113 
114 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
115 static struct file_system_type ext2_fs_type = {
116 	.owner		= THIS_MODULE,
117 	.name		= "ext2",
118 	.mount		= ext4_mount,
119 	.kill_sb	= kill_block_super,
120 	.fs_flags	= FS_REQUIRES_DEV,
121 };
122 MODULE_ALIAS_FS("ext2");
123 MODULE_ALIAS("ext2");
124 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
125 #else
126 #define IS_EXT2_SB(sb) (0)
127 #endif
128 
129 
130 static struct file_system_type ext3_fs_type = {
131 	.owner		= THIS_MODULE,
132 	.name		= "ext3",
133 	.mount		= ext4_mount,
134 	.kill_sb	= kill_block_super,
135 	.fs_flags	= FS_REQUIRES_DEV,
136 };
137 MODULE_ALIAS_FS("ext3");
138 MODULE_ALIAS("ext3");
139 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
140 
141 static int ext4_verify_csum_type(struct super_block *sb,
142 				 struct ext4_super_block *es)
143 {
144 	if (!ext4_has_feature_metadata_csum(sb))
145 		return 1;
146 
147 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
148 }
149 
150 static __le32 ext4_superblock_csum(struct super_block *sb,
151 				   struct ext4_super_block *es)
152 {
153 	struct ext4_sb_info *sbi = EXT4_SB(sb);
154 	int offset = offsetof(struct ext4_super_block, s_checksum);
155 	__u32 csum;
156 
157 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
158 
159 	return cpu_to_le32(csum);
160 }
161 
162 static int ext4_superblock_csum_verify(struct super_block *sb,
163 				       struct ext4_super_block *es)
164 {
165 	if (!ext4_has_metadata_csum(sb))
166 		return 1;
167 
168 	return es->s_checksum == ext4_superblock_csum(sb, es);
169 }
170 
171 void ext4_superblock_csum_set(struct super_block *sb)
172 {
173 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
174 
175 	if (!ext4_has_metadata_csum(sb))
176 		return;
177 
178 	es->s_checksum = ext4_superblock_csum(sb, es);
179 }
180 
181 void *ext4_kvmalloc(size_t size, gfp_t flags)
182 {
183 	void *ret;
184 
185 	ret = kmalloc(size, flags | __GFP_NOWARN);
186 	if (!ret)
187 		ret = __vmalloc(size, flags, PAGE_KERNEL);
188 	return ret;
189 }
190 
191 void *ext4_kvzalloc(size_t size, gfp_t flags)
192 {
193 	void *ret;
194 
195 	ret = kzalloc(size, flags | __GFP_NOWARN);
196 	if (!ret)
197 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
198 	return ret;
199 }
200 
201 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
202 			       struct ext4_group_desc *bg)
203 {
204 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
205 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
206 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
207 }
208 
209 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
210 			       struct ext4_group_desc *bg)
211 {
212 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
213 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
214 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
215 }
216 
217 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
218 			      struct ext4_group_desc *bg)
219 {
220 	return le32_to_cpu(bg->bg_inode_table_lo) |
221 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
222 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
223 }
224 
225 __u32 ext4_free_group_clusters(struct super_block *sb,
226 			       struct ext4_group_desc *bg)
227 {
228 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
229 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
230 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
231 }
232 
233 __u32 ext4_free_inodes_count(struct super_block *sb,
234 			      struct ext4_group_desc *bg)
235 {
236 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
237 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
238 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
239 }
240 
241 __u32 ext4_used_dirs_count(struct super_block *sb,
242 			      struct ext4_group_desc *bg)
243 {
244 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
245 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
246 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
247 }
248 
249 __u32 ext4_itable_unused_count(struct super_block *sb,
250 			      struct ext4_group_desc *bg)
251 {
252 	return le16_to_cpu(bg->bg_itable_unused_lo) |
253 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
254 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
255 }
256 
257 void ext4_block_bitmap_set(struct super_block *sb,
258 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
259 {
260 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
261 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
262 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
263 }
264 
265 void ext4_inode_bitmap_set(struct super_block *sb,
266 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
267 {
268 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
269 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
270 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
271 }
272 
273 void ext4_inode_table_set(struct super_block *sb,
274 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
275 {
276 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
277 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
278 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
279 }
280 
281 void ext4_free_group_clusters_set(struct super_block *sb,
282 				  struct ext4_group_desc *bg, __u32 count)
283 {
284 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
285 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
286 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
287 }
288 
289 void ext4_free_inodes_set(struct super_block *sb,
290 			  struct ext4_group_desc *bg, __u32 count)
291 {
292 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
293 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
294 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
295 }
296 
297 void ext4_used_dirs_set(struct super_block *sb,
298 			  struct ext4_group_desc *bg, __u32 count)
299 {
300 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
301 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
302 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
303 }
304 
305 void ext4_itable_unused_set(struct super_block *sb,
306 			  struct ext4_group_desc *bg, __u32 count)
307 {
308 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
309 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
310 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
311 }
312 
313 
314 static void __save_error_info(struct super_block *sb, const char *func,
315 			    unsigned int line)
316 {
317 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
318 
319 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
320 	if (bdev_read_only(sb->s_bdev))
321 		return;
322 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
323 	es->s_last_error_time = cpu_to_le32(get_seconds());
324 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
325 	es->s_last_error_line = cpu_to_le32(line);
326 	if (!es->s_first_error_time) {
327 		es->s_first_error_time = es->s_last_error_time;
328 		strncpy(es->s_first_error_func, func,
329 			sizeof(es->s_first_error_func));
330 		es->s_first_error_line = cpu_to_le32(line);
331 		es->s_first_error_ino = es->s_last_error_ino;
332 		es->s_first_error_block = es->s_last_error_block;
333 	}
334 	/*
335 	 * Start the daily error reporting function if it hasn't been
336 	 * started already
337 	 */
338 	if (!es->s_error_count)
339 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
340 	le32_add_cpu(&es->s_error_count, 1);
341 }
342 
343 static void save_error_info(struct super_block *sb, const char *func,
344 			    unsigned int line)
345 {
346 	__save_error_info(sb, func, line);
347 	ext4_commit_super(sb, 1);
348 }
349 
350 /*
351  * The del_gendisk() function uninitializes the disk-specific data
352  * structures, including the bdi structure, without telling anyone
353  * else.  Once this happens, any attempt to call mark_buffer_dirty()
354  * (for example, by ext4_commit_super), will cause a kernel OOPS.
355  * This is a kludge to prevent these oops until we can put in a proper
356  * hook in del_gendisk() to inform the VFS and file system layers.
357  */
358 static int block_device_ejected(struct super_block *sb)
359 {
360 	struct inode *bd_inode = sb->s_bdev->bd_inode;
361 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
362 
363 	return bdi->dev == NULL;
364 }
365 
366 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
367 {
368 	struct super_block		*sb = journal->j_private;
369 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
370 	int				error = is_journal_aborted(journal);
371 	struct ext4_journal_cb_entry	*jce;
372 
373 	BUG_ON(txn->t_state == T_FINISHED);
374 	spin_lock(&sbi->s_md_lock);
375 	while (!list_empty(&txn->t_private_list)) {
376 		jce = list_entry(txn->t_private_list.next,
377 				 struct ext4_journal_cb_entry, jce_list);
378 		list_del_init(&jce->jce_list);
379 		spin_unlock(&sbi->s_md_lock);
380 		jce->jce_func(sb, jce, error);
381 		spin_lock(&sbi->s_md_lock);
382 	}
383 	spin_unlock(&sbi->s_md_lock);
384 }
385 
386 /* Deal with the reporting of failure conditions on a filesystem such as
387  * inconsistencies detected or read IO failures.
388  *
389  * On ext2, we can store the error state of the filesystem in the
390  * superblock.  That is not possible on ext4, because we may have other
391  * write ordering constraints on the superblock which prevent us from
392  * writing it out straight away; and given that the journal is about to
393  * be aborted, we can't rely on the current, or future, transactions to
394  * write out the superblock safely.
395  *
396  * We'll just use the jbd2_journal_abort() error code to record an error in
397  * the journal instead.  On recovery, the journal will complain about
398  * that error until we've noted it down and cleared it.
399  */
400 
401 static void ext4_handle_error(struct super_block *sb)
402 {
403 	if (sb->s_flags & MS_RDONLY)
404 		return;
405 
406 	if (!test_opt(sb, ERRORS_CONT)) {
407 		journal_t *journal = EXT4_SB(sb)->s_journal;
408 
409 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
410 		if (journal)
411 			jbd2_journal_abort(journal, -EIO);
412 	}
413 	if (test_opt(sb, ERRORS_RO)) {
414 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
415 		/*
416 		 * Make sure updated value of ->s_mount_flags will be visible
417 		 * before ->s_flags update
418 		 */
419 		smp_wmb();
420 		sb->s_flags |= MS_RDONLY;
421 	}
422 	if (test_opt(sb, ERRORS_PANIC)) {
423 		if (EXT4_SB(sb)->s_journal &&
424 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
425 			return;
426 		panic("EXT4-fs (device %s): panic forced after error\n",
427 			sb->s_id);
428 	}
429 }
430 
431 #define ext4_error_ratelimit(sb)					\
432 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
433 			     "EXT4-fs error")
434 
435 void __ext4_error(struct super_block *sb, const char *function,
436 		  unsigned int line, const char *fmt, ...)
437 {
438 	struct va_format vaf;
439 	va_list args;
440 
441 	if (ext4_error_ratelimit(sb)) {
442 		va_start(args, fmt);
443 		vaf.fmt = fmt;
444 		vaf.va = &args;
445 		printk(KERN_CRIT
446 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
447 		       sb->s_id, function, line, current->comm, &vaf);
448 		va_end(args);
449 	}
450 	save_error_info(sb, function, line);
451 	ext4_handle_error(sb);
452 }
453 
454 void __ext4_error_inode(struct inode *inode, const char *function,
455 			unsigned int line, ext4_fsblk_t block,
456 			const char *fmt, ...)
457 {
458 	va_list args;
459 	struct va_format vaf;
460 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
461 
462 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
463 	es->s_last_error_block = cpu_to_le64(block);
464 	if (ext4_error_ratelimit(inode->i_sb)) {
465 		va_start(args, fmt);
466 		vaf.fmt = fmt;
467 		vaf.va = &args;
468 		if (block)
469 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
470 			       "inode #%lu: block %llu: comm %s: %pV\n",
471 			       inode->i_sb->s_id, function, line, inode->i_ino,
472 			       block, current->comm, &vaf);
473 		else
474 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
475 			       "inode #%lu: comm %s: %pV\n",
476 			       inode->i_sb->s_id, function, line, inode->i_ino,
477 			       current->comm, &vaf);
478 		va_end(args);
479 	}
480 	save_error_info(inode->i_sb, function, line);
481 	ext4_handle_error(inode->i_sb);
482 }
483 
484 void __ext4_error_file(struct file *file, const char *function,
485 		       unsigned int line, ext4_fsblk_t block,
486 		       const char *fmt, ...)
487 {
488 	va_list args;
489 	struct va_format vaf;
490 	struct ext4_super_block *es;
491 	struct inode *inode = file_inode(file);
492 	char pathname[80], *path;
493 
494 	es = EXT4_SB(inode->i_sb)->s_es;
495 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
496 	if (ext4_error_ratelimit(inode->i_sb)) {
497 		path = file_path(file, pathname, sizeof(pathname));
498 		if (IS_ERR(path))
499 			path = "(unknown)";
500 		va_start(args, fmt);
501 		vaf.fmt = fmt;
502 		vaf.va = &args;
503 		if (block)
504 			printk(KERN_CRIT
505 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
506 			       "block %llu: comm %s: path %s: %pV\n",
507 			       inode->i_sb->s_id, function, line, inode->i_ino,
508 			       block, current->comm, path, &vaf);
509 		else
510 			printk(KERN_CRIT
511 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
512 			       "comm %s: path %s: %pV\n",
513 			       inode->i_sb->s_id, function, line, inode->i_ino,
514 			       current->comm, path, &vaf);
515 		va_end(args);
516 	}
517 	save_error_info(inode->i_sb, function, line);
518 	ext4_handle_error(inode->i_sb);
519 }
520 
521 const char *ext4_decode_error(struct super_block *sb, int errno,
522 			      char nbuf[16])
523 {
524 	char *errstr = NULL;
525 
526 	switch (errno) {
527 	case -EFSCORRUPTED:
528 		errstr = "Corrupt filesystem";
529 		break;
530 	case -EFSBADCRC:
531 		errstr = "Filesystem failed CRC";
532 		break;
533 	case -EIO:
534 		errstr = "IO failure";
535 		break;
536 	case -ENOMEM:
537 		errstr = "Out of memory";
538 		break;
539 	case -EROFS:
540 		if (!sb || (EXT4_SB(sb)->s_journal &&
541 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
542 			errstr = "Journal has aborted";
543 		else
544 			errstr = "Readonly filesystem";
545 		break;
546 	default:
547 		/* If the caller passed in an extra buffer for unknown
548 		 * errors, textualise them now.  Else we just return
549 		 * NULL. */
550 		if (nbuf) {
551 			/* Check for truncated error codes... */
552 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
553 				errstr = nbuf;
554 		}
555 		break;
556 	}
557 
558 	return errstr;
559 }
560 
561 /* __ext4_std_error decodes expected errors from journaling functions
562  * automatically and invokes the appropriate error response.  */
563 
564 void __ext4_std_error(struct super_block *sb, const char *function,
565 		      unsigned int line, int errno)
566 {
567 	char nbuf[16];
568 	const char *errstr;
569 
570 	/* Special case: if the error is EROFS, and we're not already
571 	 * inside a transaction, then there's really no point in logging
572 	 * an error. */
573 	if (errno == -EROFS && journal_current_handle() == NULL &&
574 	    (sb->s_flags & MS_RDONLY))
575 		return;
576 
577 	if (ext4_error_ratelimit(sb)) {
578 		errstr = ext4_decode_error(sb, errno, nbuf);
579 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
580 		       sb->s_id, function, line, errstr);
581 	}
582 
583 	save_error_info(sb, function, line);
584 	ext4_handle_error(sb);
585 }
586 
587 /*
588  * ext4_abort is a much stronger failure handler than ext4_error.  The
589  * abort function may be used to deal with unrecoverable failures such
590  * as journal IO errors or ENOMEM at a critical moment in log management.
591  *
592  * We unconditionally force the filesystem into an ABORT|READONLY state,
593  * unless the error response on the fs has been set to panic in which
594  * case we take the easy way out and panic immediately.
595  */
596 
597 void __ext4_abort(struct super_block *sb, const char *function,
598 		unsigned int line, const char *fmt, ...)
599 {
600 	struct va_format vaf;
601 	va_list args;
602 
603 	save_error_info(sb, function, line);
604 	va_start(args, fmt);
605 	vaf.fmt = fmt;
606 	vaf.va = &args;
607 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
608 	       sb->s_id, function, line, &vaf);
609 	va_end(args);
610 
611 	if ((sb->s_flags & MS_RDONLY) == 0) {
612 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
613 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
614 		/*
615 		 * Make sure updated value of ->s_mount_flags will be visible
616 		 * before ->s_flags update
617 		 */
618 		smp_wmb();
619 		sb->s_flags |= MS_RDONLY;
620 		if (EXT4_SB(sb)->s_journal)
621 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
622 		save_error_info(sb, function, line);
623 	}
624 	if (test_opt(sb, ERRORS_PANIC)) {
625 		if (EXT4_SB(sb)->s_journal &&
626 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
627 			return;
628 		panic("EXT4-fs panic from previous error\n");
629 	}
630 }
631 
632 void __ext4_msg(struct super_block *sb,
633 		const char *prefix, const char *fmt, ...)
634 {
635 	struct va_format vaf;
636 	va_list args;
637 
638 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
639 		return;
640 
641 	va_start(args, fmt);
642 	vaf.fmt = fmt;
643 	vaf.va = &args;
644 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
645 	va_end(args);
646 }
647 
648 #define ext4_warning_ratelimit(sb)					\
649 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
650 			     "EXT4-fs warning")
651 
652 void __ext4_warning(struct super_block *sb, const char *function,
653 		    unsigned int line, const char *fmt, ...)
654 {
655 	struct va_format vaf;
656 	va_list args;
657 
658 	if (!ext4_warning_ratelimit(sb))
659 		return;
660 
661 	va_start(args, fmt);
662 	vaf.fmt = fmt;
663 	vaf.va = &args;
664 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
665 	       sb->s_id, function, line, &vaf);
666 	va_end(args);
667 }
668 
669 void __ext4_warning_inode(const struct inode *inode, const char *function,
670 			  unsigned int line, const char *fmt, ...)
671 {
672 	struct va_format vaf;
673 	va_list args;
674 
675 	if (!ext4_warning_ratelimit(inode->i_sb))
676 		return;
677 
678 	va_start(args, fmt);
679 	vaf.fmt = fmt;
680 	vaf.va = &args;
681 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
682 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
683 	       function, line, inode->i_ino, current->comm, &vaf);
684 	va_end(args);
685 }
686 
687 void __ext4_grp_locked_error(const char *function, unsigned int line,
688 			     struct super_block *sb, ext4_group_t grp,
689 			     unsigned long ino, ext4_fsblk_t block,
690 			     const char *fmt, ...)
691 __releases(bitlock)
692 __acquires(bitlock)
693 {
694 	struct va_format vaf;
695 	va_list args;
696 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
697 
698 	es->s_last_error_ino = cpu_to_le32(ino);
699 	es->s_last_error_block = cpu_to_le64(block);
700 	__save_error_info(sb, function, line);
701 
702 	if (ext4_error_ratelimit(sb)) {
703 		va_start(args, fmt);
704 		vaf.fmt = fmt;
705 		vaf.va = &args;
706 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
707 		       sb->s_id, function, line, grp);
708 		if (ino)
709 			printk(KERN_CONT "inode %lu: ", ino);
710 		if (block)
711 			printk(KERN_CONT "block %llu:",
712 			       (unsigned long long) block);
713 		printk(KERN_CONT "%pV\n", &vaf);
714 		va_end(args);
715 	}
716 
717 	if (test_opt(sb, ERRORS_CONT)) {
718 		ext4_commit_super(sb, 0);
719 		return;
720 	}
721 
722 	ext4_unlock_group(sb, grp);
723 	ext4_handle_error(sb);
724 	/*
725 	 * We only get here in the ERRORS_RO case; relocking the group
726 	 * may be dangerous, but nothing bad will happen since the
727 	 * filesystem will have already been marked read/only and the
728 	 * journal has been aborted.  We return 1 as a hint to callers
729 	 * who might what to use the return value from
730 	 * ext4_grp_locked_error() to distinguish between the
731 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
732 	 * aggressively from the ext4 function in question, with a
733 	 * more appropriate error code.
734 	 */
735 	ext4_lock_group(sb, grp);
736 	return;
737 }
738 
739 void ext4_update_dynamic_rev(struct super_block *sb)
740 {
741 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
742 
743 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
744 		return;
745 
746 	ext4_warning(sb,
747 		     "updating to rev %d because of new feature flag, "
748 		     "running e2fsck is recommended",
749 		     EXT4_DYNAMIC_REV);
750 
751 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
752 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
753 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
754 	/* leave es->s_feature_*compat flags alone */
755 	/* es->s_uuid will be set by e2fsck if empty */
756 
757 	/*
758 	 * The rest of the superblock fields should be zero, and if not it
759 	 * means they are likely already in use, so leave them alone.  We
760 	 * can leave it up to e2fsck to clean up any inconsistencies there.
761 	 */
762 }
763 
764 /*
765  * Open the external journal device
766  */
767 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
768 {
769 	struct block_device *bdev;
770 	char b[BDEVNAME_SIZE];
771 
772 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
773 	if (IS_ERR(bdev))
774 		goto fail;
775 	return bdev;
776 
777 fail:
778 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
779 			__bdevname(dev, b), PTR_ERR(bdev));
780 	return NULL;
781 }
782 
783 /*
784  * Release the journal device
785  */
786 static void ext4_blkdev_put(struct block_device *bdev)
787 {
788 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
789 }
790 
791 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
792 {
793 	struct block_device *bdev;
794 	bdev = sbi->journal_bdev;
795 	if (bdev) {
796 		ext4_blkdev_put(bdev);
797 		sbi->journal_bdev = NULL;
798 	}
799 }
800 
801 static inline struct inode *orphan_list_entry(struct list_head *l)
802 {
803 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
804 }
805 
806 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
807 {
808 	struct list_head *l;
809 
810 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
811 		 le32_to_cpu(sbi->s_es->s_last_orphan));
812 
813 	printk(KERN_ERR "sb_info orphan list:\n");
814 	list_for_each(l, &sbi->s_orphan) {
815 		struct inode *inode = orphan_list_entry(l);
816 		printk(KERN_ERR "  "
817 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
818 		       inode->i_sb->s_id, inode->i_ino, inode,
819 		       inode->i_mode, inode->i_nlink,
820 		       NEXT_ORPHAN(inode));
821 	}
822 }
823 
824 static void ext4_put_super(struct super_block *sb)
825 {
826 	struct ext4_sb_info *sbi = EXT4_SB(sb);
827 	struct ext4_super_block *es = sbi->s_es;
828 	int i, err;
829 
830 	ext4_unregister_li_request(sb);
831 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
832 
833 	flush_workqueue(sbi->rsv_conversion_wq);
834 	destroy_workqueue(sbi->rsv_conversion_wq);
835 
836 	if (sbi->s_journal) {
837 		err = jbd2_journal_destroy(sbi->s_journal);
838 		sbi->s_journal = NULL;
839 		if (err < 0)
840 			ext4_abort(sb, "Couldn't clean up the journal");
841 	}
842 
843 	ext4_unregister_sysfs(sb);
844 	ext4_es_unregister_shrinker(sbi);
845 	del_timer_sync(&sbi->s_err_report);
846 	ext4_release_system_zone(sb);
847 	ext4_mb_release(sb);
848 	ext4_ext_release(sb);
849 
850 	if (!(sb->s_flags & MS_RDONLY)) {
851 		ext4_clear_feature_journal_needs_recovery(sb);
852 		es->s_state = cpu_to_le16(sbi->s_mount_state);
853 	}
854 	if (!(sb->s_flags & MS_RDONLY))
855 		ext4_commit_super(sb, 1);
856 
857 	for (i = 0; i < sbi->s_gdb_count; i++)
858 		brelse(sbi->s_group_desc[i]);
859 	kvfree(sbi->s_group_desc);
860 	kvfree(sbi->s_flex_groups);
861 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
862 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
863 	percpu_counter_destroy(&sbi->s_dirs_counter);
864 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
865 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
866 #ifdef CONFIG_QUOTA
867 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
868 		kfree(sbi->s_qf_names[i]);
869 #endif
870 
871 	/* Debugging code just in case the in-memory inode orphan list
872 	 * isn't empty.  The on-disk one can be non-empty if we've
873 	 * detected an error and taken the fs readonly, but the
874 	 * in-memory list had better be clean by this point. */
875 	if (!list_empty(&sbi->s_orphan))
876 		dump_orphan_list(sb, sbi);
877 	J_ASSERT(list_empty(&sbi->s_orphan));
878 
879 	sync_blockdev(sb->s_bdev);
880 	invalidate_bdev(sb->s_bdev);
881 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
882 		/*
883 		 * Invalidate the journal device's buffers.  We don't want them
884 		 * floating about in memory - the physical journal device may
885 		 * hotswapped, and it breaks the `ro-after' testing code.
886 		 */
887 		sync_blockdev(sbi->journal_bdev);
888 		invalidate_bdev(sbi->journal_bdev);
889 		ext4_blkdev_remove(sbi);
890 	}
891 	if (sbi->s_mb_cache) {
892 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
893 		sbi->s_mb_cache = NULL;
894 	}
895 	if (sbi->s_mmp_tsk)
896 		kthread_stop(sbi->s_mmp_tsk);
897 	brelse(sbi->s_sbh);
898 	sb->s_fs_info = NULL;
899 	/*
900 	 * Now that we are completely done shutting down the
901 	 * superblock, we need to actually destroy the kobject.
902 	 */
903 	kobject_put(&sbi->s_kobj);
904 	wait_for_completion(&sbi->s_kobj_unregister);
905 	if (sbi->s_chksum_driver)
906 		crypto_free_shash(sbi->s_chksum_driver);
907 	kfree(sbi->s_blockgroup_lock);
908 	kfree(sbi);
909 }
910 
911 static struct kmem_cache *ext4_inode_cachep;
912 
913 /*
914  * Called inside transaction, so use GFP_NOFS
915  */
916 static struct inode *ext4_alloc_inode(struct super_block *sb)
917 {
918 	struct ext4_inode_info *ei;
919 
920 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
921 	if (!ei)
922 		return NULL;
923 
924 	ei->vfs_inode.i_version = 1;
925 	spin_lock_init(&ei->i_raw_lock);
926 	INIT_LIST_HEAD(&ei->i_prealloc_list);
927 	spin_lock_init(&ei->i_prealloc_lock);
928 	ext4_es_init_tree(&ei->i_es_tree);
929 	rwlock_init(&ei->i_es_lock);
930 	INIT_LIST_HEAD(&ei->i_es_list);
931 	ei->i_es_all_nr = 0;
932 	ei->i_es_shk_nr = 0;
933 	ei->i_es_shrink_lblk = 0;
934 	ei->i_reserved_data_blocks = 0;
935 	ei->i_reserved_meta_blocks = 0;
936 	ei->i_allocated_meta_blocks = 0;
937 	ei->i_da_metadata_calc_len = 0;
938 	ei->i_da_metadata_calc_last_lblock = 0;
939 	spin_lock_init(&(ei->i_block_reservation_lock));
940 #ifdef CONFIG_QUOTA
941 	ei->i_reserved_quota = 0;
942 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
943 #endif
944 	ei->jinode = NULL;
945 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
946 	spin_lock_init(&ei->i_completed_io_lock);
947 	ei->i_sync_tid = 0;
948 	ei->i_datasync_tid = 0;
949 	atomic_set(&ei->i_unwritten, 0);
950 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
951 	return &ei->vfs_inode;
952 }
953 
954 static int ext4_drop_inode(struct inode *inode)
955 {
956 	int drop = generic_drop_inode(inode);
957 
958 	trace_ext4_drop_inode(inode, drop);
959 	return drop;
960 }
961 
962 static void ext4_i_callback(struct rcu_head *head)
963 {
964 	struct inode *inode = container_of(head, struct inode, i_rcu);
965 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
966 }
967 
968 static void ext4_destroy_inode(struct inode *inode)
969 {
970 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
971 		ext4_msg(inode->i_sb, KERN_ERR,
972 			 "Inode %lu (%p): orphan list check failed!",
973 			 inode->i_ino, EXT4_I(inode));
974 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
975 				EXT4_I(inode), sizeof(struct ext4_inode_info),
976 				true);
977 		dump_stack();
978 	}
979 	call_rcu(&inode->i_rcu, ext4_i_callback);
980 }
981 
982 static void init_once(void *foo)
983 {
984 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
985 
986 	INIT_LIST_HEAD(&ei->i_orphan);
987 	init_rwsem(&ei->xattr_sem);
988 	init_rwsem(&ei->i_data_sem);
989 	init_rwsem(&ei->i_mmap_sem);
990 	inode_init_once(&ei->vfs_inode);
991 }
992 
993 static int __init init_inodecache(void)
994 {
995 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
996 					     sizeof(struct ext4_inode_info),
997 					     0, (SLAB_RECLAIM_ACCOUNT|
998 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
999 					     init_once);
1000 	if (ext4_inode_cachep == NULL)
1001 		return -ENOMEM;
1002 	return 0;
1003 }
1004 
1005 static void destroy_inodecache(void)
1006 {
1007 	/*
1008 	 * Make sure all delayed rcu free inodes are flushed before we
1009 	 * destroy cache.
1010 	 */
1011 	rcu_barrier();
1012 	kmem_cache_destroy(ext4_inode_cachep);
1013 }
1014 
1015 void ext4_clear_inode(struct inode *inode)
1016 {
1017 	invalidate_inode_buffers(inode);
1018 	clear_inode(inode);
1019 	dquot_drop(inode);
1020 	ext4_discard_preallocations(inode);
1021 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1022 	if (EXT4_I(inode)->jinode) {
1023 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1024 					       EXT4_I(inode)->jinode);
1025 		jbd2_free_inode(EXT4_I(inode)->jinode);
1026 		EXT4_I(inode)->jinode = NULL;
1027 	}
1028 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1029 	fscrypt_put_encryption_info(inode, NULL);
1030 #endif
1031 }
1032 
1033 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1034 					u64 ino, u32 generation)
1035 {
1036 	struct inode *inode;
1037 
1038 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1039 		return ERR_PTR(-ESTALE);
1040 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1041 		return ERR_PTR(-ESTALE);
1042 
1043 	/* iget isn't really right if the inode is currently unallocated!!
1044 	 *
1045 	 * ext4_read_inode will return a bad_inode if the inode had been
1046 	 * deleted, so we should be safe.
1047 	 *
1048 	 * Currently we don't know the generation for parent directory, so
1049 	 * a generation of 0 means "accept any"
1050 	 */
1051 	inode = ext4_iget_normal(sb, ino);
1052 	if (IS_ERR(inode))
1053 		return ERR_CAST(inode);
1054 	if (generation && inode->i_generation != generation) {
1055 		iput(inode);
1056 		return ERR_PTR(-ESTALE);
1057 	}
1058 
1059 	return inode;
1060 }
1061 
1062 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1063 					int fh_len, int fh_type)
1064 {
1065 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1066 				    ext4_nfs_get_inode);
1067 }
1068 
1069 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1070 					int fh_len, int fh_type)
1071 {
1072 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1073 				    ext4_nfs_get_inode);
1074 }
1075 
1076 /*
1077  * Try to release metadata pages (indirect blocks, directories) which are
1078  * mapped via the block device.  Since these pages could have journal heads
1079  * which would prevent try_to_free_buffers() from freeing them, we must use
1080  * jbd2 layer's try_to_free_buffers() function to release them.
1081  */
1082 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1083 				 gfp_t wait)
1084 {
1085 	journal_t *journal = EXT4_SB(sb)->s_journal;
1086 
1087 	WARN_ON(PageChecked(page));
1088 	if (!page_has_buffers(page))
1089 		return 0;
1090 	if (journal)
1091 		return jbd2_journal_try_to_free_buffers(journal, page,
1092 						wait & ~__GFP_DIRECT_RECLAIM);
1093 	return try_to_free_buffers(page);
1094 }
1095 
1096 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1097 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1098 {
1099 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1100 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1101 }
1102 
1103 static int ext4_key_prefix(struct inode *inode, u8 **key)
1104 {
1105 	*key = EXT4_SB(inode->i_sb)->key_prefix;
1106 	return EXT4_SB(inode->i_sb)->key_prefix_size;
1107 }
1108 
1109 static int ext4_prepare_context(struct inode *inode)
1110 {
1111 	return ext4_convert_inline_data(inode);
1112 }
1113 
1114 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1115 							void *fs_data)
1116 {
1117 	handle_t *handle = fs_data;
1118 	int res, res2, retries = 0;
1119 
1120 	/*
1121 	 * If a journal handle was specified, then the encryption context is
1122 	 * being set on a new inode via inheritance and is part of a larger
1123 	 * transaction to create the inode.  Otherwise the encryption context is
1124 	 * being set on an existing inode in its own transaction.  Only in the
1125 	 * latter case should the "retry on ENOSPC" logic be used.
1126 	 */
1127 
1128 	if (handle) {
1129 		res = ext4_xattr_set_handle(handle, inode,
1130 					    EXT4_XATTR_INDEX_ENCRYPTION,
1131 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1132 					    ctx, len, 0);
1133 		if (!res) {
1134 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1135 			ext4_clear_inode_state(inode,
1136 					EXT4_STATE_MAY_INLINE_DATA);
1137 			/*
1138 			 * Update inode->i_flags - e.g. S_DAX may get disabled
1139 			 */
1140 			ext4_set_inode_flags(inode);
1141 		}
1142 		return res;
1143 	}
1144 
1145 retry:
1146 	handle = ext4_journal_start(inode, EXT4_HT_MISC,
1147 			ext4_jbd2_credits_xattr(inode));
1148 	if (IS_ERR(handle))
1149 		return PTR_ERR(handle);
1150 
1151 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1152 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1153 				    ctx, len, 0);
1154 	if (!res) {
1155 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1156 		/* Update inode->i_flags - e.g. S_DAX may get disabled */
1157 		ext4_set_inode_flags(inode);
1158 		res = ext4_mark_inode_dirty(handle, inode);
1159 		if (res)
1160 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1161 	}
1162 	res2 = ext4_journal_stop(handle);
1163 
1164 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1165 		goto retry;
1166 	if (!res)
1167 		res = res2;
1168 	return res;
1169 }
1170 
1171 static int ext4_dummy_context(struct inode *inode)
1172 {
1173 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1174 }
1175 
1176 static unsigned ext4_max_namelen(struct inode *inode)
1177 {
1178 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1179 		EXT4_NAME_LEN;
1180 }
1181 
1182 static struct fscrypt_operations ext4_cryptops = {
1183 	.get_context		= ext4_get_context,
1184 	.key_prefix		= ext4_key_prefix,
1185 	.prepare_context	= ext4_prepare_context,
1186 	.set_context		= ext4_set_context,
1187 	.dummy_context		= ext4_dummy_context,
1188 	.is_encrypted		= ext4_encrypted_inode,
1189 	.empty_dir		= ext4_empty_dir,
1190 	.max_namelen		= ext4_max_namelen,
1191 };
1192 #else
1193 static struct fscrypt_operations ext4_cryptops = {
1194 	.is_encrypted		= ext4_encrypted_inode,
1195 };
1196 #endif
1197 
1198 #ifdef CONFIG_QUOTA
1199 static char *quotatypes[] = INITQFNAMES;
1200 #define QTYPE2NAME(t) (quotatypes[t])
1201 
1202 static int ext4_write_dquot(struct dquot *dquot);
1203 static int ext4_acquire_dquot(struct dquot *dquot);
1204 static int ext4_release_dquot(struct dquot *dquot);
1205 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1206 static int ext4_write_info(struct super_block *sb, int type);
1207 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1208 			 const struct path *path);
1209 static int ext4_quota_off(struct super_block *sb, int type);
1210 static int ext4_quota_on_mount(struct super_block *sb, int type);
1211 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1212 			       size_t len, loff_t off);
1213 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1214 				const char *data, size_t len, loff_t off);
1215 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1216 			     unsigned int flags);
1217 static int ext4_enable_quotas(struct super_block *sb);
1218 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1219 
1220 static struct dquot **ext4_get_dquots(struct inode *inode)
1221 {
1222 	return EXT4_I(inode)->i_dquot;
1223 }
1224 
1225 static const struct dquot_operations ext4_quota_operations = {
1226 	.get_reserved_space = ext4_get_reserved_space,
1227 	.write_dquot	= ext4_write_dquot,
1228 	.acquire_dquot	= ext4_acquire_dquot,
1229 	.release_dquot	= ext4_release_dquot,
1230 	.mark_dirty	= ext4_mark_dquot_dirty,
1231 	.write_info	= ext4_write_info,
1232 	.alloc_dquot	= dquot_alloc,
1233 	.destroy_dquot	= dquot_destroy,
1234 	.get_projid	= ext4_get_projid,
1235 	.get_next_id	= ext4_get_next_id,
1236 };
1237 
1238 static const struct quotactl_ops ext4_qctl_operations = {
1239 	.quota_on	= ext4_quota_on,
1240 	.quota_off	= ext4_quota_off,
1241 	.quota_sync	= dquot_quota_sync,
1242 	.get_state	= dquot_get_state,
1243 	.set_info	= dquot_set_dqinfo,
1244 	.get_dqblk	= dquot_get_dqblk,
1245 	.set_dqblk	= dquot_set_dqblk,
1246 	.get_nextdqblk	= dquot_get_next_dqblk,
1247 };
1248 #endif
1249 
1250 static const struct super_operations ext4_sops = {
1251 	.alloc_inode	= ext4_alloc_inode,
1252 	.destroy_inode	= ext4_destroy_inode,
1253 	.write_inode	= ext4_write_inode,
1254 	.dirty_inode	= ext4_dirty_inode,
1255 	.drop_inode	= ext4_drop_inode,
1256 	.evict_inode	= ext4_evict_inode,
1257 	.put_super	= ext4_put_super,
1258 	.sync_fs	= ext4_sync_fs,
1259 	.freeze_fs	= ext4_freeze,
1260 	.unfreeze_fs	= ext4_unfreeze,
1261 	.statfs		= ext4_statfs,
1262 	.remount_fs	= ext4_remount,
1263 	.show_options	= ext4_show_options,
1264 #ifdef CONFIG_QUOTA
1265 	.quota_read	= ext4_quota_read,
1266 	.quota_write	= ext4_quota_write,
1267 	.get_dquots	= ext4_get_dquots,
1268 #endif
1269 	.bdev_try_to_free_page = bdev_try_to_free_page,
1270 };
1271 
1272 static const struct export_operations ext4_export_ops = {
1273 	.fh_to_dentry = ext4_fh_to_dentry,
1274 	.fh_to_parent = ext4_fh_to_parent,
1275 	.get_parent = ext4_get_parent,
1276 };
1277 
1278 enum {
1279 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1280 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1281 	Opt_nouid32, Opt_debug, Opt_removed,
1282 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1283 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1284 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1285 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1286 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1287 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1288 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1289 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1290 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1291 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1292 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1293 	Opt_lazytime, Opt_nolazytime,
1294 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1295 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1296 	Opt_dioread_nolock, Opt_dioread_lock,
1297 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1298 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1299 };
1300 
1301 static const match_table_t tokens = {
1302 	{Opt_bsd_df, "bsddf"},
1303 	{Opt_minix_df, "minixdf"},
1304 	{Opt_grpid, "grpid"},
1305 	{Opt_grpid, "bsdgroups"},
1306 	{Opt_nogrpid, "nogrpid"},
1307 	{Opt_nogrpid, "sysvgroups"},
1308 	{Opt_resgid, "resgid=%u"},
1309 	{Opt_resuid, "resuid=%u"},
1310 	{Opt_sb, "sb=%u"},
1311 	{Opt_err_cont, "errors=continue"},
1312 	{Opt_err_panic, "errors=panic"},
1313 	{Opt_err_ro, "errors=remount-ro"},
1314 	{Opt_nouid32, "nouid32"},
1315 	{Opt_debug, "debug"},
1316 	{Opt_removed, "oldalloc"},
1317 	{Opt_removed, "orlov"},
1318 	{Opt_user_xattr, "user_xattr"},
1319 	{Opt_nouser_xattr, "nouser_xattr"},
1320 	{Opt_acl, "acl"},
1321 	{Opt_noacl, "noacl"},
1322 	{Opt_noload, "norecovery"},
1323 	{Opt_noload, "noload"},
1324 	{Opt_removed, "nobh"},
1325 	{Opt_removed, "bh"},
1326 	{Opt_commit, "commit=%u"},
1327 	{Opt_min_batch_time, "min_batch_time=%u"},
1328 	{Opt_max_batch_time, "max_batch_time=%u"},
1329 	{Opt_journal_dev, "journal_dev=%u"},
1330 	{Opt_journal_path, "journal_path=%s"},
1331 	{Opt_journal_checksum, "journal_checksum"},
1332 	{Opt_nojournal_checksum, "nojournal_checksum"},
1333 	{Opt_journal_async_commit, "journal_async_commit"},
1334 	{Opt_abort, "abort"},
1335 	{Opt_data_journal, "data=journal"},
1336 	{Opt_data_ordered, "data=ordered"},
1337 	{Opt_data_writeback, "data=writeback"},
1338 	{Opt_data_err_abort, "data_err=abort"},
1339 	{Opt_data_err_ignore, "data_err=ignore"},
1340 	{Opt_offusrjquota, "usrjquota="},
1341 	{Opt_usrjquota, "usrjquota=%s"},
1342 	{Opt_offgrpjquota, "grpjquota="},
1343 	{Opt_grpjquota, "grpjquota=%s"},
1344 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1345 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1346 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1347 	{Opt_grpquota, "grpquota"},
1348 	{Opt_noquota, "noquota"},
1349 	{Opt_quota, "quota"},
1350 	{Opt_usrquota, "usrquota"},
1351 	{Opt_prjquota, "prjquota"},
1352 	{Opt_barrier, "barrier=%u"},
1353 	{Opt_barrier, "barrier"},
1354 	{Opt_nobarrier, "nobarrier"},
1355 	{Opt_i_version, "i_version"},
1356 	{Opt_dax, "dax"},
1357 	{Opt_stripe, "stripe=%u"},
1358 	{Opt_delalloc, "delalloc"},
1359 	{Opt_lazytime, "lazytime"},
1360 	{Opt_nolazytime, "nolazytime"},
1361 	{Opt_nodelalloc, "nodelalloc"},
1362 	{Opt_removed, "mblk_io_submit"},
1363 	{Opt_removed, "nomblk_io_submit"},
1364 	{Opt_block_validity, "block_validity"},
1365 	{Opt_noblock_validity, "noblock_validity"},
1366 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1367 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1368 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1369 	{Opt_auto_da_alloc, "auto_da_alloc"},
1370 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1371 	{Opt_dioread_nolock, "dioread_nolock"},
1372 	{Opt_dioread_lock, "dioread_lock"},
1373 	{Opt_discard, "discard"},
1374 	{Opt_nodiscard, "nodiscard"},
1375 	{Opt_init_itable, "init_itable=%u"},
1376 	{Opt_init_itable, "init_itable"},
1377 	{Opt_noinit_itable, "noinit_itable"},
1378 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1379 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1380 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1381 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1382 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1383 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1384 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1385 	{Opt_err, NULL},
1386 };
1387 
1388 static ext4_fsblk_t get_sb_block(void **data)
1389 {
1390 	ext4_fsblk_t	sb_block;
1391 	char		*options = (char *) *data;
1392 
1393 	if (!options || strncmp(options, "sb=", 3) != 0)
1394 		return 1;	/* Default location */
1395 
1396 	options += 3;
1397 	/* TODO: use simple_strtoll with >32bit ext4 */
1398 	sb_block = simple_strtoul(options, &options, 0);
1399 	if (*options && *options != ',') {
1400 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1401 		       (char *) *data);
1402 		return 1;
1403 	}
1404 	if (*options == ',')
1405 		options++;
1406 	*data = (void *) options;
1407 
1408 	return sb_block;
1409 }
1410 
1411 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1412 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1413 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1414 
1415 #ifdef CONFIG_QUOTA
1416 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1417 {
1418 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1419 	char *qname;
1420 	int ret = -1;
1421 
1422 	if (sb_any_quota_loaded(sb) &&
1423 		!sbi->s_qf_names[qtype]) {
1424 		ext4_msg(sb, KERN_ERR,
1425 			"Cannot change journaled "
1426 			"quota options when quota turned on");
1427 		return -1;
1428 	}
1429 	if (ext4_has_feature_quota(sb)) {
1430 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1431 			 "ignored when QUOTA feature is enabled");
1432 		return 1;
1433 	}
1434 	qname = match_strdup(args);
1435 	if (!qname) {
1436 		ext4_msg(sb, KERN_ERR,
1437 			"Not enough memory for storing quotafile name");
1438 		return -1;
1439 	}
1440 	if (sbi->s_qf_names[qtype]) {
1441 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1442 			ret = 1;
1443 		else
1444 			ext4_msg(sb, KERN_ERR,
1445 				 "%s quota file already specified",
1446 				 QTYPE2NAME(qtype));
1447 		goto errout;
1448 	}
1449 	if (strchr(qname, '/')) {
1450 		ext4_msg(sb, KERN_ERR,
1451 			"quotafile must be on filesystem root");
1452 		goto errout;
1453 	}
1454 	sbi->s_qf_names[qtype] = qname;
1455 	set_opt(sb, QUOTA);
1456 	return 1;
1457 errout:
1458 	kfree(qname);
1459 	return ret;
1460 }
1461 
1462 static int clear_qf_name(struct super_block *sb, int qtype)
1463 {
1464 
1465 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1466 
1467 	if (sb_any_quota_loaded(sb) &&
1468 		sbi->s_qf_names[qtype]) {
1469 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1470 			" when quota turned on");
1471 		return -1;
1472 	}
1473 	kfree(sbi->s_qf_names[qtype]);
1474 	sbi->s_qf_names[qtype] = NULL;
1475 	return 1;
1476 }
1477 #endif
1478 
1479 #define MOPT_SET	0x0001
1480 #define MOPT_CLEAR	0x0002
1481 #define MOPT_NOSUPPORT	0x0004
1482 #define MOPT_EXPLICIT	0x0008
1483 #define MOPT_CLEAR_ERR	0x0010
1484 #define MOPT_GTE0	0x0020
1485 #ifdef CONFIG_QUOTA
1486 #define MOPT_Q		0
1487 #define MOPT_QFMT	0x0040
1488 #else
1489 #define MOPT_Q		MOPT_NOSUPPORT
1490 #define MOPT_QFMT	MOPT_NOSUPPORT
1491 #endif
1492 #define MOPT_DATAJ	0x0080
1493 #define MOPT_NO_EXT2	0x0100
1494 #define MOPT_NO_EXT3	0x0200
1495 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1496 #define MOPT_STRING	0x0400
1497 
1498 static const struct mount_opts {
1499 	int	token;
1500 	int	mount_opt;
1501 	int	flags;
1502 } ext4_mount_opts[] = {
1503 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1504 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1505 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1506 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1507 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1508 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1509 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1510 	 MOPT_EXT4_ONLY | MOPT_SET},
1511 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1512 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1513 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1514 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1515 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1516 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1517 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1518 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1519 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1520 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1521 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1522 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1523 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1524 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1525 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1526 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1527 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1528 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1529 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1530 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1531 	 MOPT_NO_EXT2},
1532 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1533 	 MOPT_NO_EXT2},
1534 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1535 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1536 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1537 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1538 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1539 	{Opt_commit, 0, MOPT_GTE0},
1540 	{Opt_max_batch_time, 0, MOPT_GTE0},
1541 	{Opt_min_batch_time, 0, MOPT_GTE0},
1542 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1543 	{Opt_init_itable, 0, MOPT_GTE0},
1544 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1545 	{Opt_stripe, 0, MOPT_GTE0},
1546 	{Opt_resuid, 0, MOPT_GTE0},
1547 	{Opt_resgid, 0, MOPT_GTE0},
1548 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1549 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1550 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1551 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1552 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1553 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1554 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1555 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1556 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1557 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1558 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1559 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1560 #else
1561 	{Opt_acl, 0, MOPT_NOSUPPORT},
1562 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1563 #endif
1564 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1565 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1566 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1567 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1568 							MOPT_SET | MOPT_Q},
1569 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1570 							MOPT_SET | MOPT_Q},
1571 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1572 							MOPT_SET | MOPT_Q},
1573 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1574 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1575 							MOPT_CLEAR | MOPT_Q},
1576 	{Opt_usrjquota, 0, MOPT_Q},
1577 	{Opt_grpjquota, 0, MOPT_Q},
1578 	{Opt_offusrjquota, 0, MOPT_Q},
1579 	{Opt_offgrpjquota, 0, MOPT_Q},
1580 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1581 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1582 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1583 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1584 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1585 	{Opt_err, 0, 0}
1586 };
1587 
1588 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1589 			    substring_t *args, unsigned long *journal_devnum,
1590 			    unsigned int *journal_ioprio, int is_remount)
1591 {
1592 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1593 	const struct mount_opts *m;
1594 	kuid_t uid;
1595 	kgid_t gid;
1596 	int arg = 0;
1597 
1598 #ifdef CONFIG_QUOTA
1599 	if (token == Opt_usrjquota)
1600 		return set_qf_name(sb, USRQUOTA, &args[0]);
1601 	else if (token == Opt_grpjquota)
1602 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1603 	else if (token == Opt_offusrjquota)
1604 		return clear_qf_name(sb, USRQUOTA);
1605 	else if (token == Opt_offgrpjquota)
1606 		return clear_qf_name(sb, GRPQUOTA);
1607 #endif
1608 	switch (token) {
1609 	case Opt_noacl:
1610 	case Opt_nouser_xattr:
1611 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1612 		break;
1613 	case Opt_sb:
1614 		return 1;	/* handled by get_sb_block() */
1615 	case Opt_removed:
1616 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1617 		return 1;
1618 	case Opt_abort:
1619 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1620 		return 1;
1621 	case Opt_i_version:
1622 		sb->s_flags |= MS_I_VERSION;
1623 		return 1;
1624 	case Opt_lazytime:
1625 		sb->s_flags |= MS_LAZYTIME;
1626 		return 1;
1627 	case Opt_nolazytime:
1628 		sb->s_flags &= ~MS_LAZYTIME;
1629 		return 1;
1630 	}
1631 
1632 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1633 		if (token == m->token)
1634 			break;
1635 
1636 	if (m->token == Opt_err) {
1637 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1638 			 "or missing value", opt);
1639 		return -1;
1640 	}
1641 
1642 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1643 		ext4_msg(sb, KERN_ERR,
1644 			 "Mount option \"%s\" incompatible with ext2", opt);
1645 		return -1;
1646 	}
1647 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1648 		ext4_msg(sb, KERN_ERR,
1649 			 "Mount option \"%s\" incompatible with ext3", opt);
1650 		return -1;
1651 	}
1652 
1653 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1654 		return -1;
1655 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1656 		return -1;
1657 	if (m->flags & MOPT_EXPLICIT) {
1658 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1659 			set_opt2(sb, EXPLICIT_DELALLOC);
1660 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1661 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1662 		} else
1663 			return -1;
1664 	}
1665 	if (m->flags & MOPT_CLEAR_ERR)
1666 		clear_opt(sb, ERRORS_MASK);
1667 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1668 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1669 			 "options when quota turned on");
1670 		return -1;
1671 	}
1672 
1673 	if (m->flags & MOPT_NOSUPPORT) {
1674 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1675 	} else if (token == Opt_commit) {
1676 		if (arg == 0)
1677 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1678 		sbi->s_commit_interval = HZ * arg;
1679 	} else if (token == Opt_max_batch_time) {
1680 		sbi->s_max_batch_time = arg;
1681 	} else if (token == Opt_min_batch_time) {
1682 		sbi->s_min_batch_time = arg;
1683 	} else if (token == Opt_inode_readahead_blks) {
1684 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1685 			ext4_msg(sb, KERN_ERR,
1686 				 "EXT4-fs: inode_readahead_blks must be "
1687 				 "0 or a power of 2 smaller than 2^31");
1688 			return -1;
1689 		}
1690 		sbi->s_inode_readahead_blks = arg;
1691 	} else if (token == Opt_init_itable) {
1692 		set_opt(sb, INIT_INODE_TABLE);
1693 		if (!args->from)
1694 			arg = EXT4_DEF_LI_WAIT_MULT;
1695 		sbi->s_li_wait_mult = arg;
1696 	} else if (token == Opt_max_dir_size_kb) {
1697 		sbi->s_max_dir_size_kb = arg;
1698 	} else if (token == Opt_stripe) {
1699 		sbi->s_stripe = arg;
1700 	} else if (token == Opt_resuid) {
1701 		uid = make_kuid(current_user_ns(), arg);
1702 		if (!uid_valid(uid)) {
1703 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1704 			return -1;
1705 		}
1706 		sbi->s_resuid = uid;
1707 	} else if (token == Opt_resgid) {
1708 		gid = make_kgid(current_user_ns(), arg);
1709 		if (!gid_valid(gid)) {
1710 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1711 			return -1;
1712 		}
1713 		sbi->s_resgid = gid;
1714 	} else if (token == Opt_journal_dev) {
1715 		if (is_remount) {
1716 			ext4_msg(sb, KERN_ERR,
1717 				 "Cannot specify journal on remount");
1718 			return -1;
1719 		}
1720 		*journal_devnum = arg;
1721 	} else if (token == Opt_journal_path) {
1722 		char *journal_path;
1723 		struct inode *journal_inode;
1724 		struct path path;
1725 		int error;
1726 
1727 		if (is_remount) {
1728 			ext4_msg(sb, KERN_ERR,
1729 				 "Cannot specify journal on remount");
1730 			return -1;
1731 		}
1732 		journal_path = match_strdup(&args[0]);
1733 		if (!journal_path) {
1734 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1735 				"journal device string");
1736 			return -1;
1737 		}
1738 
1739 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1740 		if (error) {
1741 			ext4_msg(sb, KERN_ERR, "error: could not find "
1742 				"journal device path: error %d", error);
1743 			kfree(journal_path);
1744 			return -1;
1745 		}
1746 
1747 		journal_inode = d_inode(path.dentry);
1748 		if (!S_ISBLK(journal_inode->i_mode)) {
1749 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1750 				"is not a block device", journal_path);
1751 			path_put(&path);
1752 			kfree(journal_path);
1753 			return -1;
1754 		}
1755 
1756 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1757 		path_put(&path);
1758 		kfree(journal_path);
1759 	} else if (token == Opt_journal_ioprio) {
1760 		if (arg > 7) {
1761 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1762 				 " (must be 0-7)");
1763 			return -1;
1764 		}
1765 		*journal_ioprio =
1766 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1767 	} else if (token == Opt_test_dummy_encryption) {
1768 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1769 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1770 		ext4_msg(sb, KERN_WARNING,
1771 			 "Test dummy encryption mode enabled");
1772 #else
1773 		ext4_msg(sb, KERN_WARNING,
1774 			 "Test dummy encryption mount option ignored");
1775 #endif
1776 	} else if (m->flags & MOPT_DATAJ) {
1777 		if (is_remount) {
1778 			if (!sbi->s_journal)
1779 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1780 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1781 				ext4_msg(sb, KERN_ERR,
1782 					 "Cannot change data mode on remount");
1783 				return -1;
1784 			}
1785 		} else {
1786 			clear_opt(sb, DATA_FLAGS);
1787 			sbi->s_mount_opt |= m->mount_opt;
1788 		}
1789 #ifdef CONFIG_QUOTA
1790 	} else if (m->flags & MOPT_QFMT) {
1791 		if (sb_any_quota_loaded(sb) &&
1792 		    sbi->s_jquota_fmt != m->mount_opt) {
1793 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1794 				 "quota options when quota turned on");
1795 			return -1;
1796 		}
1797 		if (ext4_has_feature_quota(sb)) {
1798 			ext4_msg(sb, KERN_INFO,
1799 				 "Quota format mount options ignored "
1800 				 "when QUOTA feature is enabled");
1801 			return 1;
1802 		}
1803 		sbi->s_jquota_fmt = m->mount_opt;
1804 #endif
1805 	} else if (token == Opt_dax) {
1806 #ifdef CONFIG_FS_DAX
1807 		ext4_msg(sb, KERN_WARNING,
1808 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1809 			sbi->s_mount_opt |= m->mount_opt;
1810 #else
1811 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1812 		return -1;
1813 #endif
1814 	} else if (token == Opt_data_err_abort) {
1815 		sbi->s_mount_opt |= m->mount_opt;
1816 	} else if (token == Opt_data_err_ignore) {
1817 		sbi->s_mount_opt &= ~m->mount_opt;
1818 	} else {
1819 		if (!args->from)
1820 			arg = 1;
1821 		if (m->flags & MOPT_CLEAR)
1822 			arg = !arg;
1823 		else if (unlikely(!(m->flags & MOPT_SET))) {
1824 			ext4_msg(sb, KERN_WARNING,
1825 				 "buggy handling of option %s", opt);
1826 			WARN_ON(1);
1827 			return -1;
1828 		}
1829 		if (arg != 0)
1830 			sbi->s_mount_opt |= m->mount_opt;
1831 		else
1832 			sbi->s_mount_opt &= ~m->mount_opt;
1833 	}
1834 	return 1;
1835 }
1836 
1837 static int parse_options(char *options, struct super_block *sb,
1838 			 unsigned long *journal_devnum,
1839 			 unsigned int *journal_ioprio,
1840 			 int is_remount)
1841 {
1842 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1843 	char *p;
1844 	substring_t args[MAX_OPT_ARGS];
1845 	int token;
1846 
1847 	if (!options)
1848 		return 1;
1849 
1850 	while ((p = strsep(&options, ",")) != NULL) {
1851 		if (!*p)
1852 			continue;
1853 		/*
1854 		 * Initialize args struct so we know whether arg was
1855 		 * found; some options take optional arguments.
1856 		 */
1857 		args[0].to = args[0].from = NULL;
1858 		token = match_token(p, tokens, args);
1859 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1860 				     journal_ioprio, is_remount) < 0)
1861 			return 0;
1862 	}
1863 #ifdef CONFIG_QUOTA
1864 	/*
1865 	 * We do the test below only for project quotas. 'usrquota' and
1866 	 * 'grpquota' mount options are allowed even without quota feature
1867 	 * to support legacy quotas in quota files.
1868 	 */
1869 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1870 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1871 			 "Cannot enable project quota enforcement.");
1872 		return 0;
1873 	}
1874 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1875 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1876 			clear_opt(sb, USRQUOTA);
1877 
1878 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1879 			clear_opt(sb, GRPQUOTA);
1880 
1881 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1882 			ext4_msg(sb, KERN_ERR, "old and new quota "
1883 					"format mixing");
1884 			return 0;
1885 		}
1886 
1887 		if (!sbi->s_jquota_fmt) {
1888 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1889 					"not specified");
1890 			return 0;
1891 		}
1892 	}
1893 #endif
1894 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1895 		int blocksize =
1896 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1897 
1898 		if (blocksize < PAGE_SIZE) {
1899 			ext4_msg(sb, KERN_ERR, "can't mount with "
1900 				 "dioread_nolock if block size != PAGE_SIZE");
1901 			return 0;
1902 		}
1903 	}
1904 	return 1;
1905 }
1906 
1907 static inline void ext4_show_quota_options(struct seq_file *seq,
1908 					   struct super_block *sb)
1909 {
1910 #if defined(CONFIG_QUOTA)
1911 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1912 
1913 	if (sbi->s_jquota_fmt) {
1914 		char *fmtname = "";
1915 
1916 		switch (sbi->s_jquota_fmt) {
1917 		case QFMT_VFS_OLD:
1918 			fmtname = "vfsold";
1919 			break;
1920 		case QFMT_VFS_V0:
1921 			fmtname = "vfsv0";
1922 			break;
1923 		case QFMT_VFS_V1:
1924 			fmtname = "vfsv1";
1925 			break;
1926 		}
1927 		seq_printf(seq, ",jqfmt=%s", fmtname);
1928 	}
1929 
1930 	if (sbi->s_qf_names[USRQUOTA])
1931 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1932 
1933 	if (sbi->s_qf_names[GRPQUOTA])
1934 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1935 #endif
1936 }
1937 
1938 static const char *token2str(int token)
1939 {
1940 	const struct match_token *t;
1941 
1942 	for (t = tokens; t->token != Opt_err; t++)
1943 		if (t->token == token && !strchr(t->pattern, '='))
1944 			break;
1945 	return t->pattern;
1946 }
1947 
1948 /*
1949  * Show an option if
1950  *  - it's set to a non-default value OR
1951  *  - if the per-sb default is different from the global default
1952  */
1953 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1954 			      int nodefs)
1955 {
1956 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1957 	struct ext4_super_block *es = sbi->s_es;
1958 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1959 	const struct mount_opts *m;
1960 	char sep = nodefs ? '\n' : ',';
1961 
1962 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1963 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1964 
1965 	if (sbi->s_sb_block != 1)
1966 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1967 
1968 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1969 		int want_set = m->flags & MOPT_SET;
1970 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1971 		    (m->flags & MOPT_CLEAR_ERR))
1972 			continue;
1973 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1974 			continue; /* skip if same as the default */
1975 		if ((want_set &&
1976 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1977 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1978 			continue; /* select Opt_noFoo vs Opt_Foo */
1979 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1980 	}
1981 
1982 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1983 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1984 		SEQ_OPTS_PRINT("resuid=%u",
1985 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1986 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1987 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1988 		SEQ_OPTS_PRINT("resgid=%u",
1989 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1990 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1991 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1992 		SEQ_OPTS_PUTS("errors=remount-ro");
1993 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1994 		SEQ_OPTS_PUTS("errors=continue");
1995 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1996 		SEQ_OPTS_PUTS("errors=panic");
1997 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1998 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1999 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2000 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2001 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2002 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2003 	if (sb->s_flags & MS_I_VERSION)
2004 		SEQ_OPTS_PUTS("i_version");
2005 	if (nodefs || sbi->s_stripe)
2006 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2007 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2008 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2009 			SEQ_OPTS_PUTS("data=journal");
2010 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2011 			SEQ_OPTS_PUTS("data=ordered");
2012 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2013 			SEQ_OPTS_PUTS("data=writeback");
2014 	}
2015 	if (nodefs ||
2016 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2017 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2018 			       sbi->s_inode_readahead_blks);
2019 
2020 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2021 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2022 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2023 	if (nodefs || sbi->s_max_dir_size_kb)
2024 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2025 	if (test_opt(sb, DATA_ERR_ABORT))
2026 		SEQ_OPTS_PUTS("data_err=abort");
2027 
2028 	ext4_show_quota_options(seq, sb);
2029 	return 0;
2030 }
2031 
2032 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2033 {
2034 	return _ext4_show_options(seq, root->d_sb, 0);
2035 }
2036 
2037 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2038 {
2039 	struct super_block *sb = seq->private;
2040 	int rc;
2041 
2042 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2043 	rc = _ext4_show_options(seq, sb, 1);
2044 	seq_puts(seq, "\n");
2045 	return rc;
2046 }
2047 
2048 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2049 			    int read_only)
2050 {
2051 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2052 	int res = 0;
2053 
2054 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2055 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2056 			 "forcing read-only mode");
2057 		res = MS_RDONLY;
2058 	}
2059 	if (read_only)
2060 		goto done;
2061 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2062 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2063 			 "running e2fsck is recommended");
2064 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2065 		ext4_msg(sb, KERN_WARNING,
2066 			 "warning: mounting fs with errors, "
2067 			 "running e2fsck is recommended");
2068 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2069 		 le16_to_cpu(es->s_mnt_count) >=
2070 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2071 		ext4_msg(sb, KERN_WARNING,
2072 			 "warning: maximal mount count reached, "
2073 			 "running e2fsck is recommended");
2074 	else if (le32_to_cpu(es->s_checkinterval) &&
2075 		(le32_to_cpu(es->s_lastcheck) +
2076 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2077 		ext4_msg(sb, KERN_WARNING,
2078 			 "warning: checktime reached, "
2079 			 "running e2fsck is recommended");
2080 	if (!sbi->s_journal)
2081 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2082 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2083 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2084 	le16_add_cpu(&es->s_mnt_count, 1);
2085 	es->s_mtime = cpu_to_le32(get_seconds());
2086 	ext4_update_dynamic_rev(sb);
2087 	if (sbi->s_journal)
2088 		ext4_set_feature_journal_needs_recovery(sb);
2089 
2090 	ext4_commit_super(sb, 1);
2091 done:
2092 	if (test_opt(sb, DEBUG))
2093 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2094 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2095 			sb->s_blocksize,
2096 			sbi->s_groups_count,
2097 			EXT4_BLOCKS_PER_GROUP(sb),
2098 			EXT4_INODES_PER_GROUP(sb),
2099 			sbi->s_mount_opt, sbi->s_mount_opt2);
2100 
2101 	cleancache_init_fs(sb);
2102 	return res;
2103 }
2104 
2105 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2106 {
2107 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2108 	struct flex_groups *new_groups;
2109 	int size;
2110 
2111 	if (!sbi->s_log_groups_per_flex)
2112 		return 0;
2113 
2114 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2115 	if (size <= sbi->s_flex_groups_allocated)
2116 		return 0;
2117 
2118 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2119 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2120 	if (!new_groups) {
2121 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2122 			 size / (int) sizeof(struct flex_groups));
2123 		return -ENOMEM;
2124 	}
2125 
2126 	if (sbi->s_flex_groups) {
2127 		memcpy(new_groups, sbi->s_flex_groups,
2128 		       (sbi->s_flex_groups_allocated *
2129 			sizeof(struct flex_groups)));
2130 		kvfree(sbi->s_flex_groups);
2131 	}
2132 	sbi->s_flex_groups = new_groups;
2133 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2134 	return 0;
2135 }
2136 
2137 static int ext4_fill_flex_info(struct super_block *sb)
2138 {
2139 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2140 	struct ext4_group_desc *gdp = NULL;
2141 	ext4_group_t flex_group;
2142 	int i, err;
2143 
2144 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2145 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2146 		sbi->s_log_groups_per_flex = 0;
2147 		return 1;
2148 	}
2149 
2150 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2151 	if (err)
2152 		goto failed;
2153 
2154 	for (i = 0; i < sbi->s_groups_count; i++) {
2155 		gdp = ext4_get_group_desc(sb, i, NULL);
2156 
2157 		flex_group = ext4_flex_group(sbi, i);
2158 		atomic_add(ext4_free_inodes_count(sb, gdp),
2159 			   &sbi->s_flex_groups[flex_group].free_inodes);
2160 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2161 			     &sbi->s_flex_groups[flex_group].free_clusters);
2162 		atomic_add(ext4_used_dirs_count(sb, gdp),
2163 			   &sbi->s_flex_groups[flex_group].used_dirs);
2164 	}
2165 
2166 	return 1;
2167 failed:
2168 	return 0;
2169 }
2170 
2171 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2172 				   struct ext4_group_desc *gdp)
2173 {
2174 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2175 	__u16 crc = 0;
2176 	__le32 le_group = cpu_to_le32(block_group);
2177 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2178 
2179 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2180 		/* Use new metadata_csum algorithm */
2181 		__u32 csum32;
2182 		__u16 dummy_csum = 0;
2183 
2184 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2185 				     sizeof(le_group));
2186 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2187 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2188 				     sizeof(dummy_csum));
2189 		offset += sizeof(dummy_csum);
2190 		if (offset < sbi->s_desc_size)
2191 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2192 					     sbi->s_desc_size - offset);
2193 
2194 		crc = csum32 & 0xFFFF;
2195 		goto out;
2196 	}
2197 
2198 	/* old crc16 code */
2199 	if (!ext4_has_feature_gdt_csum(sb))
2200 		return 0;
2201 
2202 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2203 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2204 	crc = crc16(crc, (__u8 *)gdp, offset);
2205 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2206 	/* for checksum of struct ext4_group_desc do the rest...*/
2207 	if (ext4_has_feature_64bit(sb) &&
2208 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2209 		crc = crc16(crc, (__u8 *)gdp + offset,
2210 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2211 				offset);
2212 
2213 out:
2214 	return cpu_to_le16(crc);
2215 }
2216 
2217 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2218 				struct ext4_group_desc *gdp)
2219 {
2220 	if (ext4_has_group_desc_csum(sb) &&
2221 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2222 		return 0;
2223 
2224 	return 1;
2225 }
2226 
2227 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2228 			      struct ext4_group_desc *gdp)
2229 {
2230 	if (!ext4_has_group_desc_csum(sb))
2231 		return;
2232 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2233 }
2234 
2235 /* Called at mount-time, super-block is locked */
2236 static int ext4_check_descriptors(struct super_block *sb,
2237 				  ext4_fsblk_t sb_block,
2238 				  ext4_group_t *first_not_zeroed)
2239 {
2240 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2241 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2242 	ext4_fsblk_t last_block;
2243 	ext4_fsblk_t block_bitmap;
2244 	ext4_fsblk_t inode_bitmap;
2245 	ext4_fsblk_t inode_table;
2246 	int flexbg_flag = 0;
2247 	ext4_group_t i, grp = sbi->s_groups_count;
2248 
2249 	if (ext4_has_feature_flex_bg(sb))
2250 		flexbg_flag = 1;
2251 
2252 	ext4_debug("Checking group descriptors");
2253 
2254 	for (i = 0; i < sbi->s_groups_count; i++) {
2255 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2256 
2257 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2258 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2259 		else
2260 			last_block = first_block +
2261 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2262 
2263 		if ((grp == sbi->s_groups_count) &&
2264 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2265 			grp = i;
2266 
2267 		block_bitmap = ext4_block_bitmap(sb, gdp);
2268 		if (block_bitmap == sb_block) {
2269 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2270 				 "Block bitmap for group %u overlaps "
2271 				 "superblock", i);
2272 		}
2273 		if (block_bitmap < first_block || block_bitmap > last_block) {
2274 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2275 			       "Block bitmap for group %u not in group "
2276 			       "(block %llu)!", i, block_bitmap);
2277 			return 0;
2278 		}
2279 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2280 		if (inode_bitmap == sb_block) {
2281 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2282 				 "Inode bitmap for group %u overlaps "
2283 				 "superblock", i);
2284 		}
2285 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2286 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2287 			       "Inode bitmap for group %u not in group "
2288 			       "(block %llu)!", i, inode_bitmap);
2289 			return 0;
2290 		}
2291 		inode_table = ext4_inode_table(sb, gdp);
2292 		if (inode_table == sb_block) {
2293 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2294 				 "Inode table for group %u overlaps "
2295 				 "superblock", i);
2296 		}
2297 		if (inode_table < first_block ||
2298 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2299 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2300 			       "Inode table for group %u not in group "
2301 			       "(block %llu)!", i, inode_table);
2302 			return 0;
2303 		}
2304 		ext4_lock_group(sb, i);
2305 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2306 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2307 				 "Checksum for group %u failed (%u!=%u)",
2308 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2309 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2310 			if (!(sb->s_flags & MS_RDONLY)) {
2311 				ext4_unlock_group(sb, i);
2312 				return 0;
2313 			}
2314 		}
2315 		ext4_unlock_group(sb, i);
2316 		if (!flexbg_flag)
2317 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2318 	}
2319 	if (NULL != first_not_zeroed)
2320 		*first_not_zeroed = grp;
2321 	return 1;
2322 }
2323 
2324 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2325  * the superblock) which were deleted from all directories, but held open by
2326  * a process at the time of a crash.  We walk the list and try to delete these
2327  * inodes at recovery time (only with a read-write filesystem).
2328  *
2329  * In order to keep the orphan inode chain consistent during traversal (in
2330  * case of crash during recovery), we link each inode into the superblock
2331  * orphan list_head and handle it the same way as an inode deletion during
2332  * normal operation (which journals the operations for us).
2333  *
2334  * We only do an iget() and an iput() on each inode, which is very safe if we
2335  * accidentally point at an in-use or already deleted inode.  The worst that
2336  * can happen in this case is that we get a "bit already cleared" message from
2337  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2338  * e2fsck was run on this filesystem, and it must have already done the orphan
2339  * inode cleanup for us, so we can safely abort without any further action.
2340  */
2341 static void ext4_orphan_cleanup(struct super_block *sb,
2342 				struct ext4_super_block *es)
2343 {
2344 	unsigned int s_flags = sb->s_flags;
2345 	int ret, nr_orphans = 0, nr_truncates = 0;
2346 #ifdef CONFIG_QUOTA
2347 	int i;
2348 #endif
2349 	if (!es->s_last_orphan) {
2350 		jbd_debug(4, "no orphan inodes to clean up\n");
2351 		return;
2352 	}
2353 
2354 	if (bdev_read_only(sb->s_bdev)) {
2355 		ext4_msg(sb, KERN_ERR, "write access "
2356 			"unavailable, skipping orphan cleanup");
2357 		return;
2358 	}
2359 
2360 	/* Check if feature set would not allow a r/w mount */
2361 	if (!ext4_feature_set_ok(sb, 0)) {
2362 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2363 			 "unknown ROCOMPAT features");
2364 		return;
2365 	}
2366 
2367 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2368 		/* don't clear list on RO mount w/ errors */
2369 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2370 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2371 				  "clearing orphan list.\n");
2372 			es->s_last_orphan = 0;
2373 		}
2374 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2375 		return;
2376 	}
2377 
2378 	if (s_flags & MS_RDONLY) {
2379 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2380 		sb->s_flags &= ~MS_RDONLY;
2381 	}
2382 #ifdef CONFIG_QUOTA
2383 	/* Needed for iput() to work correctly and not trash data */
2384 	sb->s_flags |= MS_ACTIVE;
2385 	/* Turn on quotas so that they are updated correctly */
2386 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2387 		if (EXT4_SB(sb)->s_qf_names[i]) {
2388 			int ret = ext4_quota_on_mount(sb, i);
2389 			if (ret < 0)
2390 				ext4_msg(sb, KERN_ERR,
2391 					"Cannot turn on journaled "
2392 					"quota: error %d", ret);
2393 		}
2394 	}
2395 #endif
2396 
2397 	while (es->s_last_orphan) {
2398 		struct inode *inode;
2399 
2400 		/*
2401 		 * We may have encountered an error during cleanup; if
2402 		 * so, skip the rest.
2403 		 */
2404 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2405 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2406 			es->s_last_orphan = 0;
2407 			break;
2408 		}
2409 
2410 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2411 		if (IS_ERR(inode)) {
2412 			es->s_last_orphan = 0;
2413 			break;
2414 		}
2415 
2416 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2417 		dquot_initialize(inode);
2418 		if (inode->i_nlink) {
2419 			if (test_opt(sb, DEBUG))
2420 				ext4_msg(sb, KERN_DEBUG,
2421 					"%s: truncating inode %lu to %lld bytes",
2422 					__func__, inode->i_ino, inode->i_size);
2423 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2424 				  inode->i_ino, inode->i_size);
2425 			inode_lock(inode);
2426 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2427 			ret = ext4_truncate(inode);
2428 			if (ret)
2429 				ext4_std_error(inode->i_sb, ret);
2430 			inode_unlock(inode);
2431 			nr_truncates++;
2432 		} else {
2433 			if (test_opt(sb, DEBUG))
2434 				ext4_msg(sb, KERN_DEBUG,
2435 					"%s: deleting unreferenced inode %lu",
2436 					__func__, inode->i_ino);
2437 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2438 				  inode->i_ino);
2439 			nr_orphans++;
2440 		}
2441 		iput(inode);  /* The delete magic happens here! */
2442 	}
2443 
2444 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2445 
2446 	if (nr_orphans)
2447 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2448 		       PLURAL(nr_orphans));
2449 	if (nr_truncates)
2450 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2451 		       PLURAL(nr_truncates));
2452 #ifdef CONFIG_QUOTA
2453 	/* Turn quotas off */
2454 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2455 		if (sb_dqopt(sb)->files[i])
2456 			dquot_quota_off(sb, i);
2457 	}
2458 #endif
2459 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2460 }
2461 
2462 /*
2463  * Maximal extent format file size.
2464  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2465  * extent format containers, within a sector_t, and within i_blocks
2466  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2467  * so that won't be a limiting factor.
2468  *
2469  * However there is other limiting factor. We do store extents in the form
2470  * of starting block and length, hence the resulting length of the extent
2471  * covering maximum file size must fit into on-disk format containers as
2472  * well. Given that length is always by 1 unit bigger than max unit (because
2473  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2474  *
2475  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2476  */
2477 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2478 {
2479 	loff_t res;
2480 	loff_t upper_limit = MAX_LFS_FILESIZE;
2481 
2482 	/* small i_blocks in vfs inode? */
2483 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2484 		/*
2485 		 * CONFIG_LBDAF is not enabled implies the inode
2486 		 * i_block represent total blocks in 512 bytes
2487 		 * 32 == size of vfs inode i_blocks * 8
2488 		 */
2489 		upper_limit = (1LL << 32) - 1;
2490 
2491 		/* total blocks in file system block size */
2492 		upper_limit >>= (blkbits - 9);
2493 		upper_limit <<= blkbits;
2494 	}
2495 
2496 	/*
2497 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2498 	 * by one fs block, so ee_len can cover the extent of maximum file
2499 	 * size
2500 	 */
2501 	res = (1LL << 32) - 1;
2502 	res <<= blkbits;
2503 
2504 	/* Sanity check against vm- & vfs- imposed limits */
2505 	if (res > upper_limit)
2506 		res = upper_limit;
2507 
2508 	return res;
2509 }
2510 
2511 /*
2512  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2513  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2514  * We need to be 1 filesystem block less than the 2^48 sector limit.
2515  */
2516 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2517 {
2518 	loff_t res = EXT4_NDIR_BLOCKS;
2519 	int meta_blocks;
2520 	loff_t upper_limit;
2521 	/* This is calculated to be the largest file size for a dense, block
2522 	 * mapped file such that the file's total number of 512-byte sectors,
2523 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2524 	 *
2525 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2526 	 * number of 512-byte sectors of the file.
2527 	 */
2528 
2529 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2530 		/*
2531 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2532 		 * the inode i_block field represents total file blocks in
2533 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2534 		 */
2535 		upper_limit = (1LL << 32) - 1;
2536 
2537 		/* total blocks in file system block size */
2538 		upper_limit >>= (bits - 9);
2539 
2540 	} else {
2541 		/*
2542 		 * We use 48 bit ext4_inode i_blocks
2543 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2544 		 * represent total number of blocks in
2545 		 * file system block size
2546 		 */
2547 		upper_limit = (1LL << 48) - 1;
2548 
2549 	}
2550 
2551 	/* indirect blocks */
2552 	meta_blocks = 1;
2553 	/* double indirect blocks */
2554 	meta_blocks += 1 + (1LL << (bits-2));
2555 	/* tripple indirect blocks */
2556 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2557 
2558 	upper_limit -= meta_blocks;
2559 	upper_limit <<= bits;
2560 
2561 	res += 1LL << (bits-2);
2562 	res += 1LL << (2*(bits-2));
2563 	res += 1LL << (3*(bits-2));
2564 	res <<= bits;
2565 	if (res > upper_limit)
2566 		res = upper_limit;
2567 
2568 	if (res > MAX_LFS_FILESIZE)
2569 		res = MAX_LFS_FILESIZE;
2570 
2571 	return res;
2572 }
2573 
2574 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2575 				   ext4_fsblk_t logical_sb_block, int nr)
2576 {
2577 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2578 	ext4_group_t bg, first_meta_bg;
2579 	int has_super = 0;
2580 
2581 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2582 
2583 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2584 		return logical_sb_block + nr + 1;
2585 	bg = sbi->s_desc_per_block * nr;
2586 	if (ext4_bg_has_super(sb, bg))
2587 		has_super = 1;
2588 
2589 	/*
2590 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2591 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2592 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2593 	 * compensate.
2594 	 */
2595 	if (sb->s_blocksize == 1024 && nr == 0 &&
2596 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2597 		has_super++;
2598 
2599 	return (has_super + ext4_group_first_block_no(sb, bg));
2600 }
2601 
2602 /**
2603  * ext4_get_stripe_size: Get the stripe size.
2604  * @sbi: In memory super block info
2605  *
2606  * If we have specified it via mount option, then
2607  * use the mount option value. If the value specified at mount time is
2608  * greater than the blocks per group use the super block value.
2609  * If the super block value is greater than blocks per group return 0.
2610  * Allocator needs it be less than blocks per group.
2611  *
2612  */
2613 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2614 {
2615 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2616 	unsigned long stripe_width =
2617 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2618 	int ret;
2619 
2620 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2621 		ret = sbi->s_stripe;
2622 	else if (stripe_width <= sbi->s_blocks_per_group)
2623 		ret = stripe_width;
2624 	else if (stride <= sbi->s_blocks_per_group)
2625 		ret = stride;
2626 	else
2627 		ret = 0;
2628 
2629 	/*
2630 	 * If the stripe width is 1, this makes no sense and
2631 	 * we set it to 0 to turn off stripe handling code.
2632 	 */
2633 	if (ret <= 1)
2634 		ret = 0;
2635 
2636 	return ret;
2637 }
2638 
2639 /*
2640  * Check whether this filesystem can be mounted based on
2641  * the features present and the RDONLY/RDWR mount requested.
2642  * Returns 1 if this filesystem can be mounted as requested,
2643  * 0 if it cannot be.
2644  */
2645 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2646 {
2647 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2648 		ext4_msg(sb, KERN_ERR,
2649 			"Couldn't mount because of "
2650 			"unsupported optional features (%x)",
2651 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2652 			~EXT4_FEATURE_INCOMPAT_SUPP));
2653 		return 0;
2654 	}
2655 
2656 	if (readonly)
2657 		return 1;
2658 
2659 	if (ext4_has_feature_readonly(sb)) {
2660 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2661 		sb->s_flags |= MS_RDONLY;
2662 		return 1;
2663 	}
2664 
2665 	/* Check that feature set is OK for a read-write mount */
2666 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2667 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2668 			 "unsupported optional features (%x)",
2669 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2670 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2671 		return 0;
2672 	}
2673 	/*
2674 	 * Large file size enabled file system can only be mounted
2675 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2676 	 */
2677 	if (ext4_has_feature_huge_file(sb)) {
2678 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2679 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2680 				 "cannot be mounted RDWR without "
2681 				 "CONFIG_LBDAF");
2682 			return 0;
2683 		}
2684 	}
2685 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2686 		ext4_msg(sb, KERN_ERR,
2687 			 "Can't support bigalloc feature without "
2688 			 "extents feature\n");
2689 		return 0;
2690 	}
2691 
2692 #ifndef CONFIG_QUOTA
2693 	if (ext4_has_feature_quota(sb) && !readonly) {
2694 		ext4_msg(sb, KERN_ERR,
2695 			 "Filesystem with quota feature cannot be mounted RDWR "
2696 			 "without CONFIG_QUOTA");
2697 		return 0;
2698 	}
2699 	if (ext4_has_feature_project(sb) && !readonly) {
2700 		ext4_msg(sb, KERN_ERR,
2701 			 "Filesystem with project quota feature cannot be mounted RDWR "
2702 			 "without CONFIG_QUOTA");
2703 		return 0;
2704 	}
2705 #endif  /* CONFIG_QUOTA */
2706 	return 1;
2707 }
2708 
2709 /*
2710  * This function is called once a day if we have errors logged
2711  * on the file system
2712  */
2713 static void print_daily_error_info(unsigned long arg)
2714 {
2715 	struct super_block *sb = (struct super_block *) arg;
2716 	struct ext4_sb_info *sbi;
2717 	struct ext4_super_block *es;
2718 
2719 	sbi = EXT4_SB(sb);
2720 	es = sbi->s_es;
2721 
2722 	if (es->s_error_count)
2723 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2724 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2725 			 le32_to_cpu(es->s_error_count));
2726 	if (es->s_first_error_time) {
2727 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2728 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2729 		       (int) sizeof(es->s_first_error_func),
2730 		       es->s_first_error_func,
2731 		       le32_to_cpu(es->s_first_error_line));
2732 		if (es->s_first_error_ino)
2733 			printk(KERN_CONT ": inode %u",
2734 			       le32_to_cpu(es->s_first_error_ino));
2735 		if (es->s_first_error_block)
2736 			printk(KERN_CONT ": block %llu", (unsigned long long)
2737 			       le64_to_cpu(es->s_first_error_block));
2738 		printk(KERN_CONT "\n");
2739 	}
2740 	if (es->s_last_error_time) {
2741 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2742 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2743 		       (int) sizeof(es->s_last_error_func),
2744 		       es->s_last_error_func,
2745 		       le32_to_cpu(es->s_last_error_line));
2746 		if (es->s_last_error_ino)
2747 			printk(KERN_CONT ": inode %u",
2748 			       le32_to_cpu(es->s_last_error_ino));
2749 		if (es->s_last_error_block)
2750 			printk(KERN_CONT ": block %llu", (unsigned long long)
2751 			       le64_to_cpu(es->s_last_error_block));
2752 		printk(KERN_CONT "\n");
2753 	}
2754 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2755 }
2756 
2757 /* Find next suitable group and run ext4_init_inode_table */
2758 static int ext4_run_li_request(struct ext4_li_request *elr)
2759 {
2760 	struct ext4_group_desc *gdp = NULL;
2761 	ext4_group_t group, ngroups;
2762 	struct super_block *sb;
2763 	unsigned long timeout = 0;
2764 	int ret = 0;
2765 
2766 	sb = elr->lr_super;
2767 	ngroups = EXT4_SB(sb)->s_groups_count;
2768 
2769 	for (group = elr->lr_next_group; group < ngroups; group++) {
2770 		gdp = ext4_get_group_desc(sb, group, NULL);
2771 		if (!gdp) {
2772 			ret = 1;
2773 			break;
2774 		}
2775 
2776 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2777 			break;
2778 	}
2779 
2780 	if (group >= ngroups)
2781 		ret = 1;
2782 
2783 	if (!ret) {
2784 		timeout = jiffies;
2785 		ret = ext4_init_inode_table(sb, group,
2786 					    elr->lr_timeout ? 0 : 1);
2787 		if (elr->lr_timeout == 0) {
2788 			timeout = (jiffies - timeout) *
2789 				  elr->lr_sbi->s_li_wait_mult;
2790 			elr->lr_timeout = timeout;
2791 		}
2792 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2793 		elr->lr_next_group = group + 1;
2794 	}
2795 	return ret;
2796 }
2797 
2798 /*
2799  * Remove lr_request from the list_request and free the
2800  * request structure. Should be called with li_list_mtx held
2801  */
2802 static void ext4_remove_li_request(struct ext4_li_request *elr)
2803 {
2804 	struct ext4_sb_info *sbi;
2805 
2806 	if (!elr)
2807 		return;
2808 
2809 	sbi = elr->lr_sbi;
2810 
2811 	list_del(&elr->lr_request);
2812 	sbi->s_li_request = NULL;
2813 	kfree(elr);
2814 }
2815 
2816 static void ext4_unregister_li_request(struct super_block *sb)
2817 {
2818 	mutex_lock(&ext4_li_mtx);
2819 	if (!ext4_li_info) {
2820 		mutex_unlock(&ext4_li_mtx);
2821 		return;
2822 	}
2823 
2824 	mutex_lock(&ext4_li_info->li_list_mtx);
2825 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2826 	mutex_unlock(&ext4_li_info->li_list_mtx);
2827 	mutex_unlock(&ext4_li_mtx);
2828 }
2829 
2830 static struct task_struct *ext4_lazyinit_task;
2831 
2832 /*
2833  * This is the function where ext4lazyinit thread lives. It walks
2834  * through the request list searching for next scheduled filesystem.
2835  * When such a fs is found, run the lazy initialization request
2836  * (ext4_rn_li_request) and keep track of the time spend in this
2837  * function. Based on that time we compute next schedule time of
2838  * the request. When walking through the list is complete, compute
2839  * next waking time and put itself into sleep.
2840  */
2841 static int ext4_lazyinit_thread(void *arg)
2842 {
2843 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2844 	struct list_head *pos, *n;
2845 	struct ext4_li_request *elr;
2846 	unsigned long next_wakeup, cur;
2847 
2848 	BUG_ON(NULL == eli);
2849 
2850 cont_thread:
2851 	while (true) {
2852 		next_wakeup = MAX_JIFFY_OFFSET;
2853 
2854 		mutex_lock(&eli->li_list_mtx);
2855 		if (list_empty(&eli->li_request_list)) {
2856 			mutex_unlock(&eli->li_list_mtx);
2857 			goto exit_thread;
2858 		}
2859 		list_for_each_safe(pos, n, &eli->li_request_list) {
2860 			int err = 0;
2861 			int progress = 0;
2862 			elr = list_entry(pos, struct ext4_li_request,
2863 					 lr_request);
2864 
2865 			if (time_before(jiffies, elr->lr_next_sched)) {
2866 				if (time_before(elr->lr_next_sched, next_wakeup))
2867 					next_wakeup = elr->lr_next_sched;
2868 				continue;
2869 			}
2870 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2871 				if (sb_start_write_trylock(elr->lr_super)) {
2872 					progress = 1;
2873 					/*
2874 					 * We hold sb->s_umount, sb can not
2875 					 * be removed from the list, it is
2876 					 * now safe to drop li_list_mtx
2877 					 */
2878 					mutex_unlock(&eli->li_list_mtx);
2879 					err = ext4_run_li_request(elr);
2880 					sb_end_write(elr->lr_super);
2881 					mutex_lock(&eli->li_list_mtx);
2882 					n = pos->next;
2883 				}
2884 				up_read((&elr->lr_super->s_umount));
2885 			}
2886 			/* error, remove the lazy_init job */
2887 			if (err) {
2888 				ext4_remove_li_request(elr);
2889 				continue;
2890 			}
2891 			if (!progress) {
2892 				elr->lr_next_sched = jiffies +
2893 					(prandom_u32()
2894 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2895 			}
2896 			if (time_before(elr->lr_next_sched, next_wakeup))
2897 				next_wakeup = elr->lr_next_sched;
2898 		}
2899 		mutex_unlock(&eli->li_list_mtx);
2900 
2901 		try_to_freeze();
2902 
2903 		cur = jiffies;
2904 		if ((time_after_eq(cur, next_wakeup)) ||
2905 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2906 			cond_resched();
2907 			continue;
2908 		}
2909 
2910 		schedule_timeout_interruptible(next_wakeup - cur);
2911 
2912 		if (kthread_should_stop()) {
2913 			ext4_clear_request_list();
2914 			goto exit_thread;
2915 		}
2916 	}
2917 
2918 exit_thread:
2919 	/*
2920 	 * It looks like the request list is empty, but we need
2921 	 * to check it under the li_list_mtx lock, to prevent any
2922 	 * additions into it, and of course we should lock ext4_li_mtx
2923 	 * to atomically free the list and ext4_li_info, because at
2924 	 * this point another ext4 filesystem could be registering
2925 	 * new one.
2926 	 */
2927 	mutex_lock(&ext4_li_mtx);
2928 	mutex_lock(&eli->li_list_mtx);
2929 	if (!list_empty(&eli->li_request_list)) {
2930 		mutex_unlock(&eli->li_list_mtx);
2931 		mutex_unlock(&ext4_li_mtx);
2932 		goto cont_thread;
2933 	}
2934 	mutex_unlock(&eli->li_list_mtx);
2935 	kfree(ext4_li_info);
2936 	ext4_li_info = NULL;
2937 	mutex_unlock(&ext4_li_mtx);
2938 
2939 	return 0;
2940 }
2941 
2942 static void ext4_clear_request_list(void)
2943 {
2944 	struct list_head *pos, *n;
2945 	struct ext4_li_request *elr;
2946 
2947 	mutex_lock(&ext4_li_info->li_list_mtx);
2948 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2949 		elr = list_entry(pos, struct ext4_li_request,
2950 				 lr_request);
2951 		ext4_remove_li_request(elr);
2952 	}
2953 	mutex_unlock(&ext4_li_info->li_list_mtx);
2954 }
2955 
2956 static int ext4_run_lazyinit_thread(void)
2957 {
2958 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2959 					 ext4_li_info, "ext4lazyinit");
2960 	if (IS_ERR(ext4_lazyinit_task)) {
2961 		int err = PTR_ERR(ext4_lazyinit_task);
2962 		ext4_clear_request_list();
2963 		kfree(ext4_li_info);
2964 		ext4_li_info = NULL;
2965 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2966 				 "initialization thread\n",
2967 				 err);
2968 		return err;
2969 	}
2970 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2971 	return 0;
2972 }
2973 
2974 /*
2975  * Check whether it make sense to run itable init. thread or not.
2976  * If there is at least one uninitialized inode table, return
2977  * corresponding group number, else the loop goes through all
2978  * groups and return total number of groups.
2979  */
2980 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2981 {
2982 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2983 	struct ext4_group_desc *gdp = NULL;
2984 
2985 	for (group = 0; group < ngroups; group++) {
2986 		gdp = ext4_get_group_desc(sb, group, NULL);
2987 		if (!gdp)
2988 			continue;
2989 
2990 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2991 			break;
2992 	}
2993 
2994 	return group;
2995 }
2996 
2997 static int ext4_li_info_new(void)
2998 {
2999 	struct ext4_lazy_init *eli = NULL;
3000 
3001 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3002 	if (!eli)
3003 		return -ENOMEM;
3004 
3005 	INIT_LIST_HEAD(&eli->li_request_list);
3006 	mutex_init(&eli->li_list_mtx);
3007 
3008 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3009 
3010 	ext4_li_info = eli;
3011 
3012 	return 0;
3013 }
3014 
3015 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3016 					    ext4_group_t start)
3017 {
3018 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3019 	struct ext4_li_request *elr;
3020 
3021 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3022 	if (!elr)
3023 		return NULL;
3024 
3025 	elr->lr_super = sb;
3026 	elr->lr_sbi = sbi;
3027 	elr->lr_next_group = start;
3028 
3029 	/*
3030 	 * Randomize first schedule time of the request to
3031 	 * spread the inode table initialization requests
3032 	 * better.
3033 	 */
3034 	elr->lr_next_sched = jiffies + (prandom_u32() %
3035 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3036 	return elr;
3037 }
3038 
3039 int ext4_register_li_request(struct super_block *sb,
3040 			     ext4_group_t first_not_zeroed)
3041 {
3042 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3043 	struct ext4_li_request *elr = NULL;
3044 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3045 	int ret = 0;
3046 
3047 	mutex_lock(&ext4_li_mtx);
3048 	if (sbi->s_li_request != NULL) {
3049 		/*
3050 		 * Reset timeout so it can be computed again, because
3051 		 * s_li_wait_mult might have changed.
3052 		 */
3053 		sbi->s_li_request->lr_timeout = 0;
3054 		goto out;
3055 	}
3056 
3057 	if (first_not_zeroed == ngroups ||
3058 	    (sb->s_flags & MS_RDONLY) ||
3059 	    !test_opt(sb, INIT_INODE_TABLE))
3060 		goto out;
3061 
3062 	elr = ext4_li_request_new(sb, first_not_zeroed);
3063 	if (!elr) {
3064 		ret = -ENOMEM;
3065 		goto out;
3066 	}
3067 
3068 	if (NULL == ext4_li_info) {
3069 		ret = ext4_li_info_new();
3070 		if (ret)
3071 			goto out;
3072 	}
3073 
3074 	mutex_lock(&ext4_li_info->li_list_mtx);
3075 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3076 	mutex_unlock(&ext4_li_info->li_list_mtx);
3077 
3078 	sbi->s_li_request = elr;
3079 	/*
3080 	 * set elr to NULL here since it has been inserted to
3081 	 * the request_list and the removal and free of it is
3082 	 * handled by ext4_clear_request_list from now on.
3083 	 */
3084 	elr = NULL;
3085 
3086 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3087 		ret = ext4_run_lazyinit_thread();
3088 		if (ret)
3089 			goto out;
3090 	}
3091 out:
3092 	mutex_unlock(&ext4_li_mtx);
3093 	if (ret)
3094 		kfree(elr);
3095 	return ret;
3096 }
3097 
3098 /*
3099  * We do not need to lock anything since this is called on
3100  * module unload.
3101  */
3102 static void ext4_destroy_lazyinit_thread(void)
3103 {
3104 	/*
3105 	 * If thread exited earlier
3106 	 * there's nothing to be done.
3107 	 */
3108 	if (!ext4_li_info || !ext4_lazyinit_task)
3109 		return;
3110 
3111 	kthread_stop(ext4_lazyinit_task);
3112 }
3113 
3114 static int set_journal_csum_feature_set(struct super_block *sb)
3115 {
3116 	int ret = 1;
3117 	int compat, incompat;
3118 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3119 
3120 	if (ext4_has_metadata_csum(sb)) {
3121 		/* journal checksum v3 */
3122 		compat = 0;
3123 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3124 	} else {
3125 		/* journal checksum v1 */
3126 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3127 		incompat = 0;
3128 	}
3129 
3130 	jbd2_journal_clear_features(sbi->s_journal,
3131 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3132 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3133 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3134 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3135 		ret = jbd2_journal_set_features(sbi->s_journal,
3136 				compat, 0,
3137 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3138 				incompat);
3139 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3140 		ret = jbd2_journal_set_features(sbi->s_journal,
3141 				compat, 0,
3142 				incompat);
3143 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3144 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3145 	} else {
3146 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3147 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3148 	}
3149 
3150 	return ret;
3151 }
3152 
3153 /*
3154  * Note: calculating the overhead so we can be compatible with
3155  * historical BSD practice is quite difficult in the face of
3156  * clusters/bigalloc.  This is because multiple metadata blocks from
3157  * different block group can end up in the same allocation cluster.
3158  * Calculating the exact overhead in the face of clustered allocation
3159  * requires either O(all block bitmaps) in memory or O(number of block
3160  * groups**2) in time.  We will still calculate the superblock for
3161  * older file systems --- and if we come across with a bigalloc file
3162  * system with zero in s_overhead_clusters the estimate will be close to
3163  * correct especially for very large cluster sizes --- but for newer
3164  * file systems, it's better to calculate this figure once at mkfs
3165  * time, and store it in the superblock.  If the superblock value is
3166  * present (even for non-bigalloc file systems), we will use it.
3167  */
3168 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3169 			  char *buf)
3170 {
3171 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3172 	struct ext4_group_desc	*gdp;
3173 	ext4_fsblk_t		first_block, last_block, b;
3174 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3175 	int			s, j, count = 0;
3176 
3177 	if (!ext4_has_feature_bigalloc(sb))
3178 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3179 			sbi->s_itb_per_group + 2);
3180 
3181 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3182 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3183 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3184 	for (i = 0; i < ngroups; i++) {
3185 		gdp = ext4_get_group_desc(sb, i, NULL);
3186 		b = ext4_block_bitmap(sb, gdp);
3187 		if (b >= first_block && b <= last_block) {
3188 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3189 			count++;
3190 		}
3191 		b = ext4_inode_bitmap(sb, gdp);
3192 		if (b >= first_block && b <= last_block) {
3193 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3194 			count++;
3195 		}
3196 		b = ext4_inode_table(sb, gdp);
3197 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3198 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3199 				int c = EXT4_B2C(sbi, b - first_block);
3200 				ext4_set_bit(c, buf);
3201 				count++;
3202 			}
3203 		if (i != grp)
3204 			continue;
3205 		s = 0;
3206 		if (ext4_bg_has_super(sb, grp)) {
3207 			ext4_set_bit(s++, buf);
3208 			count++;
3209 		}
3210 		j = ext4_bg_num_gdb(sb, grp);
3211 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3212 			ext4_error(sb, "Invalid number of block group "
3213 				   "descriptor blocks: %d", j);
3214 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3215 		}
3216 		count += j;
3217 		for (; j > 0; j--)
3218 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3219 	}
3220 	if (!count)
3221 		return 0;
3222 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3223 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3224 }
3225 
3226 /*
3227  * Compute the overhead and stash it in sbi->s_overhead
3228  */
3229 int ext4_calculate_overhead(struct super_block *sb)
3230 {
3231 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3232 	struct ext4_super_block *es = sbi->s_es;
3233 	struct inode *j_inode;
3234 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3235 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3236 	ext4_fsblk_t overhead = 0;
3237 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3238 
3239 	if (!buf)
3240 		return -ENOMEM;
3241 
3242 	/*
3243 	 * Compute the overhead (FS structures).  This is constant
3244 	 * for a given filesystem unless the number of block groups
3245 	 * changes so we cache the previous value until it does.
3246 	 */
3247 
3248 	/*
3249 	 * All of the blocks before first_data_block are overhead
3250 	 */
3251 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3252 
3253 	/*
3254 	 * Add the overhead found in each block group
3255 	 */
3256 	for (i = 0; i < ngroups; i++) {
3257 		int blks;
3258 
3259 		blks = count_overhead(sb, i, buf);
3260 		overhead += blks;
3261 		if (blks)
3262 			memset(buf, 0, PAGE_SIZE);
3263 		cond_resched();
3264 	}
3265 
3266 	/*
3267 	 * Add the internal journal blocks whether the journal has been
3268 	 * loaded or not
3269 	 */
3270 	if (sbi->s_journal && !sbi->journal_bdev)
3271 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3272 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3273 		j_inode = ext4_get_journal_inode(sb, j_inum);
3274 		if (j_inode) {
3275 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3276 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3277 			iput(j_inode);
3278 		} else {
3279 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3280 		}
3281 	}
3282 	sbi->s_overhead = overhead;
3283 	smp_wmb();
3284 	free_page((unsigned long) buf);
3285 	return 0;
3286 }
3287 
3288 static void ext4_set_resv_clusters(struct super_block *sb)
3289 {
3290 	ext4_fsblk_t resv_clusters;
3291 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3292 
3293 	/*
3294 	 * There's no need to reserve anything when we aren't using extents.
3295 	 * The space estimates are exact, there are no unwritten extents,
3296 	 * hole punching doesn't need new metadata... This is needed especially
3297 	 * to keep ext2/3 backward compatibility.
3298 	 */
3299 	if (!ext4_has_feature_extents(sb))
3300 		return;
3301 	/*
3302 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3303 	 * This should cover the situations where we can not afford to run
3304 	 * out of space like for example punch hole, or converting
3305 	 * unwritten extents in delalloc path. In most cases such
3306 	 * allocation would require 1, or 2 blocks, higher numbers are
3307 	 * very rare.
3308 	 */
3309 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3310 			 sbi->s_cluster_bits);
3311 
3312 	do_div(resv_clusters, 50);
3313 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3314 
3315 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3316 }
3317 
3318 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3319 {
3320 	char *orig_data = kstrdup(data, GFP_KERNEL);
3321 	struct buffer_head *bh;
3322 	struct ext4_super_block *es = NULL;
3323 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3324 	ext4_fsblk_t block;
3325 	ext4_fsblk_t sb_block = get_sb_block(&data);
3326 	ext4_fsblk_t logical_sb_block;
3327 	unsigned long offset = 0;
3328 	unsigned long journal_devnum = 0;
3329 	unsigned long def_mount_opts;
3330 	struct inode *root;
3331 	const char *descr;
3332 	int ret = -ENOMEM;
3333 	int blocksize, clustersize;
3334 	unsigned int db_count;
3335 	unsigned int i;
3336 	int needs_recovery, has_huge_files, has_bigalloc;
3337 	__u64 blocks_count;
3338 	int err = 0;
3339 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3340 	ext4_group_t first_not_zeroed;
3341 
3342 	if ((data && !orig_data) || !sbi)
3343 		goto out_free_base;
3344 
3345 	sbi->s_blockgroup_lock =
3346 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3347 	if (!sbi->s_blockgroup_lock)
3348 		goto out_free_base;
3349 
3350 	sb->s_fs_info = sbi;
3351 	sbi->s_sb = sb;
3352 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3353 	sbi->s_sb_block = sb_block;
3354 	if (sb->s_bdev->bd_part)
3355 		sbi->s_sectors_written_start =
3356 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3357 
3358 	/* Cleanup superblock name */
3359 	strreplace(sb->s_id, '/', '!');
3360 
3361 	/* -EINVAL is default */
3362 	ret = -EINVAL;
3363 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3364 	if (!blocksize) {
3365 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3366 		goto out_fail;
3367 	}
3368 
3369 	/*
3370 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3371 	 * block sizes.  We need to calculate the offset from buffer start.
3372 	 */
3373 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3374 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3375 		offset = do_div(logical_sb_block, blocksize);
3376 	} else {
3377 		logical_sb_block = sb_block;
3378 	}
3379 
3380 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3381 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3382 		goto out_fail;
3383 	}
3384 	/*
3385 	 * Note: s_es must be initialized as soon as possible because
3386 	 *       some ext4 macro-instructions depend on its value
3387 	 */
3388 	es = (struct ext4_super_block *) (bh->b_data + offset);
3389 	sbi->s_es = es;
3390 	sb->s_magic = le16_to_cpu(es->s_magic);
3391 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3392 		goto cantfind_ext4;
3393 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3394 
3395 	/* Warn if metadata_csum and gdt_csum are both set. */
3396 	if (ext4_has_feature_metadata_csum(sb) &&
3397 	    ext4_has_feature_gdt_csum(sb))
3398 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3399 			     "redundant flags; please run fsck.");
3400 
3401 	/* Check for a known checksum algorithm */
3402 	if (!ext4_verify_csum_type(sb, es)) {
3403 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3404 			 "unknown checksum algorithm.");
3405 		silent = 1;
3406 		goto cantfind_ext4;
3407 	}
3408 
3409 	/* Load the checksum driver */
3410 	if (ext4_has_feature_metadata_csum(sb)) {
3411 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3412 		if (IS_ERR(sbi->s_chksum_driver)) {
3413 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3414 			ret = PTR_ERR(sbi->s_chksum_driver);
3415 			sbi->s_chksum_driver = NULL;
3416 			goto failed_mount;
3417 		}
3418 	}
3419 
3420 	/* Check superblock checksum */
3421 	if (!ext4_superblock_csum_verify(sb, es)) {
3422 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3423 			 "invalid superblock checksum.  Run e2fsck?");
3424 		silent = 1;
3425 		ret = -EFSBADCRC;
3426 		goto cantfind_ext4;
3427 	}
3428 
3429 	/* Precompute checksum seed for all metadata */
3430 	if (ext4_has_feature_csum_seed(sb))
3431 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3432 	else if (ext4_has_metadata_csum(sb))
3433 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3434 					       sizeof(es->s_uuid));
3435 
3436 	/* Set defaults before we parse the mount options */
3437 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3438 	set_opt(sb, INIT_INODE_TABLE);
3439 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3440 		set_opt(sb, DEBUG);
3441 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3442 		set_opt(sb, GRPID);
3443 	if (def_mount_opts & EXT4_DEFM_UID16)
3444 		set_opt(sb, NO_UID32);
3445 	/* xattr user namespace & acls are now defaulted on */
3446 	set_opt(sb, XATTR_USER);
3447 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3448 	set_opt(sb, POSIX_ACL);
3449 #endif
3450 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3451 	if (ext4_has_metadata_csum(sb))
3452 		set_opt(sb, JOURNAL_CHECKSUM);
3453 
3454 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3455 		set_opt(sb, JOURNAL_DATA);
3456 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3457 		set_opt(sb, ORDERED_DATA);
3458 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3459 		set_opt(sb, WRITEBACK_DATA);
3460 
3461 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3462 		set_opt(sb, ERRORS_PANIC);
3463 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3464 		set_opt(sb, ERRORS_CONT);
3465 	else
3466 		set_opt(sb, ERRORS_RO);
3467 	/* block_validity enabled by default; disable with noblock_validity */
3468 	set_opt(sb, BLOCK_VALIDITY);
3469 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3470 		set_opt(sb, DISCARD);
3471 
3472 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3473 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3474 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3475 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3476 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3477 
3478 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3479 		set_opt(sb, BARRIER);
3480 
3481 	/*
3482 	 * enable delayed allocation by default
3483 	 * Use -o nodelalloc to turn it off
3484 	 */
3485 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3486 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3487 		set_opt(sb, DELALLOC);
3488 
3489 	/*
3490 	 * set default s_li_wait_mult for lazyinit, for the case there is
3491 	 * no mount option specified.
3492 	 */
3493 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3494 
3495 	if (sbi->s_es->s_mount_opts[0]) {
3496 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3497 					      sizeof(sbi->s_es->s_mount_opts),
3498 					      GFP_KERNEL);
3499 		if (!s_mount_opts)
3500 			goto failed_mount;
3501 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3502 				   &journal_ioprio, 0)) {
3503 			ext4_msg(sb, KERN_WARNING,
3504 				 "failed to parse options in superblock: %s",
3505 				 s_mount_opts);
3506 		}
3507 		kfree(s_mount_opts);
3508 	}
3509 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3510 	if (!parse_options((char *) data, sb, &journal_devnum,
3511 			   &journal_ioprio, 0))
3512 		goto failed_mount;
3513 
3514 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3515 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3516 			    "with data=journal disables delayed "
3517 			    "allocation and O_DIRECT support!\n");
3518 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3519 			ext4_msg(sb, KERN_ERR, "can't mount with "
3520 				 "both data=journal and delalloc");
3521 			goto failed_mount;
3522 		}
3523 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3524 			ext4_msg(sb, KERN_ERR, "can't mount with "
3525 				 "both data=journal and dioread_nolock");
3526 			goto failed_mount;
3527 		}
3528 		if (test_opt(sb, DAX)) {
3529 			ext4_msg(sb, KERN_ERR, "can't mount with "
3530 				 "both data=journal and dax");
3531 			goto failed_mount;
3532 		}
3533 		if (ext4_has_feature_encrypt(sb)) {
3534 			ext4_msg(sb, KERN_WARNING,
3535 				 "encrypted files will use data=ordered "
3536 				 "instead of data journaling mode");
3537 		}
3538 		if (test_opt(sb, DELALLOC))
3539 			clear_opt(sb, DELALLOC);
3540 	} else {
3541 		sb->s_iflags |= SB_I_CGROUPWB;
3542 	}
3543 
3544 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3545 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3546 
3547 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3548 	    (ext4_has_compat_features(sb) ||
3549 	     ext4_has_ro_compat_features(sb) ||
3550 	     ext4_has_incompat_features(sb)))
3551 		ext4_msg(sb, KERN_WARNING,
3552 		       "feature flags set on rev 0 fs, "
3553 		       "running e2fsck is recommended");
3554 
3555 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3556 		set_opt2(sb, HURD_COMPAT);
3557 		if (ext4_has_feature_64bit(sb)) {
3558 			ext4_msg(sb, KERN_ERR,
3559 				 "The Hurd can't support 64-bit file systems");
3560 			goto failed_mount;
3561 		}
3562 	}
3563 
3564 	if (IS_EXT2_SB(sb)) {
3565 		if (ext2_feature_set_ok(sb))
3566 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3567 				 "using the ext4 subsystem");
3568 		else {
3569 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3570 				 "to feature incompatibilities");
3571 			goto failed_mount;
3572 		}
3573 	}
3574 
3575 	if (IS_EXT3_SB(sb)) {
3576 		if (ext3_feature_set_ok(sb))
3577 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3578 				 "using the ext4 subsystem");
3579 		else {
3580 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3581 				 "to feature incompatibilities");
3582 			goto failed_mount;
3583 		}
3584 	}
3585 
3586 	/*
3587 	 * Check feature flags regardless of the revision level, since we
3588 	 * previously didn't change the revision level when setting the flags,
3589 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3590 	 */
3591 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3592 		goto failed_mount;
3593 
3594 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3595 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3596 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3597 		ext4_msg(sb, KERN_ERR,
3598 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3599 			 blocksize, le32_to_cpu(es->s_log_block_size));
3600 		goto failed_mount;
3601 	}
3602 	if (le32_to_cpu(es->s_log_block_size) >
3603 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3604 		ext4_msg(sb, KERN_ERR,
3605 			 "Invalid log block size: %u",
3606 			 le32_to_cpu(es->s_log_block_size));
3607 		goto failed_mount;
3608 	}
3609 
3610 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3611 		ext4_msg(sb, KERN_ERR,
3612 			 "Number of reserved GDT blocks insanely large: %d",
3613 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3614 		goto failed_mount;
3615 	}
3616 
3617 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3618 		err = bdev_dax_supported(sb, blocksize);
3619 		if (err)
3620 			goto failed_mount;
3621 	}
3622 
3623 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3624 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3625 			 es->s_encryption_level);
3626 		goto failed_mount;
3627 	}
3628 
3629 	if (sb->s_blocksize != blocksize) {
3630 		/* Validate the filesystem blocksize */
3631 		if (!sb_set_blocksize(sb, blocksize)) {
3632 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3633 					blocksize);
3634 			goto failed_mount;
3635 		}
3636 
3637 		brelse(bh);
3638 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3639 		offset = do_div(logical_sb_block, blocksize);
3640 		bh = sb_bread_unmovable(sb, logical_sb_block);
3641 		if (!bh) {
3642 			ext4_msg(sb, KERN_ERR,
3643 			       "Can't read superblock on 2nd try");
3644 			goto failed_mount;
3645 		}
3646 		es = (struct ext4_super_block *)(bh->b_data + offset);
3647 		sbi->s_es = es;
3648 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3649 			ext4_msg(sb, KERN_ERR,
3650 			       "Magic mismatch, very weird!");
3651 			goto failed_mount;
3652 		}
3653 	}
3654 
3655 	has_huge_files = ext4_has_feature_huge_file(sb);
3656 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3657 						      has_huge_files);
3658 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3659 
3660 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3661 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3662 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3663 	} else {
3664 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3665 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3666 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3667 		    (!is_power_of_2(sbi->s_inode_size)) ||
3668 		    (sbi->s_inode_size > blocksize)) {
3669 			ext4_msg(sb, KERN_ERR,
3670 			       "unsupported inode size: %d",
3671 			       sbi->s_inode_size);
3672 			goto failed_mount;
3673 		}
3674 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3675 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3676 	}
3677 
3678 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3679 	if (ext4_has_feature_64bit(sb)) {
3680 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3681 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3682 		    !is_power_of_2(sbi->s_desc_size)) {
3683 			ext4_msg(sb, KERN_ERR,
3684 			       "unsupported descriptor size %lu",
3685 			       sbi->s_desc_size);
3686 			goto failed_mount;
3687 		}
3688 	} else
3689 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3690 
3691 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3692 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3693 
3694 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3695 	if (sbi->s_inodes_per_block == 0)
3696 		goto cantfind_ext4;
3697 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3698 	    sbi->s_inodes_per_group > blocksize * 8) {
3699 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3700 			 sbi->s_blocks_per_group);
3701 		goto failed_mount;
3702 	}
3703 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3704 					sbi->s_inodes_per_block;
3705 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3706 	sbi->s_sbh = bh;
3707 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3708 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3709 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3710 
3711 	for (i = 0; i < 4; i++)
3712 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3713 	sbi->s_def_hash_version = es->s_def_hash_version;
3714 	if (ext4_has_feature_dir_index(sb)) {
3715 		i = le32_to_cpu(es->s_flags);
3716 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3717 			sbi->s_hash_unsigned = 3;
3718 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3719 #ifdef __CHAR_UNSIGNED__
3720 			if (!(sb->s_flags & MS_RDONLY))
3721 				es->s_flags |=
3722 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3723 			sbi->s_hash_unsigned = 3;
3724 #else
3725 			if (!(sb->s_flags & MS_RDONLY))
3726 				es->s_flags |=
3727 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3728 #endif
3729 		}
3730 	}
3731 
3732 	/* Handle clustersize */
3733 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3734 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3735 	if (has_bigalloc) {
3736 		if (clustersize < blocksize) {
3737 			ext4_msg(sb, KERN_ERR,
3738 				 "cluster size (%d) smaller than "
3739 				 "block size (%d)", clustersize, blocksize);
3740 			goto failed_mount;
3741 		}
3742 		if (le32_to_cpu(es->s_log_cluster_size) >
3743 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3744 			ext4_msg(sb, KERN_ERR,
3745 				 "Invalid log cluster size: %u",
3746 				 le32_to_cpu(es->s_log_cluster_size));
3747 			goto failed_mount;
3748 		}
3749 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3750 			le32_to_cpu(es->s_log_block_size);
3751 		sbi->s_clusters_per_group =
3752 			le32_to_cpu(es->s_clusters_per_group);
3753 		if (sbi->s_clusters_per_group > blocksize * 8) {
3754 			ext4_msg(sb, KERN_ERR,
3755 				 "#clusters per group too big: %lu",
3756 				 sbi->s_clusters_per_group);
3757 			goto failed_mount;
3758 		}
3759 		if (sbi->s_blocks_per_group !=
3760 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3761 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3762 				 "clusters per group (%lu) inconsistent",
3763 				 sbi->s_blocks_per_group,
3764 				 sbi->s_clusters_per_group);
3765 			goto failed_mount;
3766 		}
3767 	} else {
3768 		if (clustersize != blocksize) {
3769 			ext4_warning(sb, "fragment/cluster size (%d) != "
3770 				     "block size (%d)", clustersize,
3771 				     blocksize);
3772 			clustersize = blocksize;
3773 		}
3774 		if (sbi->s_blocks_per_group > blocksize * 8) {
3775 			ext4_msg(sb, KERN_ERR,
3776 				 "#blocks per group too big: %lu",
3777 				 sbi->s_blocks_per_group);
3778 			goto failed_mount;
3779 		}
3780 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3781 		sbi->s_cluster_bits = 0;
3782 	}
3783 	sbi->s_cluster_ratio = clustersize / blocksize;
3784 
3785 	/* Do we have standard group size of clustersize * 8 blocks ? */
3786 	if (sbi->s_blocks_per_group == clustersize << 3)
3787 		set_opt2(sb, STD_GROUP_SIZE);
3788 
3789 	/*
3790 	 * Test whether we have more sectors than will fit in sector_t,
3791 	 * and whether the max offset is addressable by the page cache.
3792 	 */
3793 	err = generic_check_addressable(sb->s_blocksize_bits,
3794 					ext4_blocks_count(es));
3795 	if (err) {
3796 		ext4_msg(sb, KERN_ERR, "filesystem"
3797 			 " too large to mount safely on this system");
3798 		if (sizeof(sector_t) < 8)
3799 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3800 		goto failed_mount;
3801 	}
3802 
3803 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3804 		goto cantfind_ext4;
3805 
3806 	/* check blocks count against device size */
3807 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3808 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3809 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3810 		       "exceeds size of device (%llu blocks)",
3811 		       ext4_blocks_count(es), blocks_count);
3812 		goto failed_mount;
3813 	}
3814 
3815 	/*
3816 	 * It makes no sense for the first data block to be beyond the end
3817 	 * of the filesystem.
3818 	 */
3819 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3820 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3821 			 "block %u is beyond end of filesystem (%llu)",
3822 			 le32_to_cpu(es->s_first_data_block),
3823 			 ext4_blocks_count(es));
3824 		goto failed_mount;
3825 	}
3826 	blocks_count = (ext4_blocks_count(es) -
3827 			le32_to_cpu(es->s_first_data_block) +
3828 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3829 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3830 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3831 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3832 		       "(block count %llu, first data block %u, "
3833 		       "blocks per group %lu)", sbi->s_groups_count,
3834 		       ext4_blocks_count(es),
3835 		       le32_to_cpu(es->s_first_data_block),
3836 		       EXT4_BLOCKS_PER_GROUP(sb));
3837 		goto failed_mount;
3838 	}
3839 	sbi->s_groups_count = blocks_count;
3840 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3841 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3842 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3843 		   EXT4_DESC_PER_BLOCK(sb);
3844 	if (ext4_has_feature_meta_bg(sb)) {
3845 		if (le32_to_cpu(es->s_first_meta_bg) >= db_count) {
3846 			ext4_msg(sb, KERN_WARNING,
3847 				 "first meta block group too large: %u "
3848 				 "(group descriptor block count %u)",
3849 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3850 			goto failed_mount;
3851 		}
3852 	}
3853 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3854 					  sizeof(struct buffer_head *),
3855 					  GFP_KERNEL);
3856 	if (sbi->s_group_desc == NULL) {
3857 		ext4_msg(sb, KERN_ERR, "not enough memory");
3858 		ret = -ENOMEM;
3859 		goto failed_mount;
3860 	}
3861 
3862 	bgl_lock_init(sbi->s_blockgroup_lock);
3863 
3864 	for (i = 0; i < db_count; i++) {
3865 		block = descriptor_loc(sb, logical_sb_block, i);
3866 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3867 		if (!sbi->s_group_desc[i]) {
3868 			ext4_msg(sb, KERN_ERR,
3869 			       "can't read group descriptor %d", i);
3870 			db_count = i;
3871 			goto failed_mount2;
3872 		}
3873 	}
3874 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3875 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3876 		ret = -EFSCORRUPTED;
3877 		goto failed_mount2;
3878 	}
3879 
3880 	sbi->s_gdb_count = db_count;
3881 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3882 	spin_lock_init(&sbi->s_next_gen_lock);
3883 
3884 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3885 		(unsigned long) sb);
3886 
3887 	/* Register extent status tree shrinker */
3888 	if (ext4_es_register_shrinker(sbi))
3889 		goto failed_mount3;
3890 
3891 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3892 	sbi->s_extent_max_zeroout_kb = 32;
3893 
3894 	/*
3895 	 * set up enough so that it can read an inode
3896 	 */
3897 	sb->s_op = &ext4_sops;
3898 	sb->s_export_op = &ext4_export_ops;
3899 	sb->s_xattr = ext4_xattr_handlers;
3900 	sb->s_cop = &ext4_cryptops;
3901 #ifdef CONFIG_QUOTA
3902 	sb->dq_op = &ext4_quota_operations;
3903 	if (ext4_has_feature_quota(sb))
3904 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3905 	else
3906 		sb->s_qcop = &ext4_qctl_operations;
3907 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3908 #endif
3909 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3910 
3911 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3912 	mutex_init(&sbi->s_orphan_lock);
3913 
3914 	sb->s_root = NULL;
3915 
3916 	needs_recovery = (es->s_last_orphan != 0 ||
3917 			  ext4_has_feature_journal_needs_recovery(sb));
3918 
3919 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3920 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3921 			goto failed_mount3a;
3922 
3923 	/*
3924 	 * The first inode we look at is the journal inode.  Don't try
3925 	 * root first: it may be modified in the journal!
3926 	 */
3927 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3928 		if (ext4_load_journal(sb, es, journal_devnum))
3929 			goto failed_mount3a;
3930 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3931 		   ext4_has_feature_journal_needs_recovery(sb)) {
3932 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3933 		       "suppressed and not mounted read-only");
3934 		goto failed_mount_wq;
3935 	} else {
3936 		/* Nojournal mode, all journal mount options are illegal */
3937 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3938 			ext4_msg(sb, KERN_ERR, "can't mount with "
3939 				 "journal_checksum, fs mounted w/o journal");
3940 			goto failed_mount_wq;
3941 		}
3942 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3943 			ext4_msg(sb, KERN_ERR, "can't mount with "
3944 				 "journal_async_commit, fs mounted w/o journal");
3945 			goto failed_mount_wq;
3946 		}
3947 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3948 			ext4_msg(sb, KERN_ERR, "can't mount with "
3949 				 "commit=%lu, fs mounted w/o journal",
3950 				 sbi->s_commit_interval / HZ);
3951 			goto failed_mount_wq;
3952 		}
3953 		if (EXT4_MOUNT_DATA_FLAGS &
3954 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3955 			ext4_msg(sb, KERN_ERR, "can't mount with "
3956 				 "data=, fs mounted w/o journal");
3957 			goto failed_mount_wq;
3958 		}
3959 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3960 		clear_opt(sb, JOURNAL_CHECKSUM);
3961 		clear_opt(sb, DATA_FLAGS);
3962 		sbi->s_journal = NULL;
3963 		needs_recovery = 0;
3964 		goto no_journal;
3965 	}
3966 
3967 	if (ext4_has_feature_64bit(sb) &&
3968 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3969 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3970 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3971 		goto failed_mount_wq;
3972 	}
3973 
3974 	if (!set_journal_csum_feature_set(sb)) {
3975 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3976 			 "feature set");
3977 		goto failed_mount_wq;
3978 	}
3979 
3980 	/* We have now updated the journal if required, so we can
3981 	 * validate the data journaling mode. */
3982 	switch (test_opt(sb, DATA_FLAGS)) {
3983 	case 0:
3984 		/* No mode set, assume a default based on the journal
3985 		 * capabilities: ORDERED_DATA if the journal can
3986 		 * cope, else JOURNAL_DATA
3987 		 */
3988 		if (jbd2_journal_check_available_features
3989 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3990 			set_opt(sb, ORDERED_DATA);
3991 		else
3992 			set_opt(sb, JOURNAL_DATA);
3993 		break;
3994 
3995 	case EXT4_MOUNT_ORDERED_DATA:
3996 	case EXT4_MOUNT_WRITEBACK_DATA:
3997 		if (!jbd2_journal_check_available_features
3998 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3999 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4000 			       "requested data journaling mode");
4001 			goto failed_mount_wq;
4002 		}
4003 	default:
4004 		break;
4005 	}
4006 
4007 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4008 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4009 		ext4_msg(sb, KERN_ERR, "can't mount with "
4010 			"journal_async_commit in data=ordered mode");
4011 		goto failed_mount_wq;
4012 	}
4013 
4014 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4015 
4016 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4017 
4018 no_journal:
4019 	sbi->s_mb_cache = ext4_xattr_create_cache();
4020 	if (!sbi->s_mb_cache) {
4021 		ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4022 		goto failed_mount_wq;
4023 	}
4024 
4025 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4026 	    (blocksize != PAGE_SIZE)) {
4027 		ext4_msg(sb, KERN_ERR,
4028 			 "Unsupported blocksize for fs encryption");
4029 		goto failed_mount_wq;
4030 	}
4031 
4032 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4033 	    !ext4_has_feature_encrypt(sb)) {
4034 		ext4_set_feature_encrypt(sb);
4035 		ext4_commit_super(sb, 1);
4036 	}
4037 
4038 	/*
4039 	 * Get the # of file system overhead blocks from the
4040 	 * superblock if present.
4041 	 */
4042 	if (es->s_overhead_clusters)
4043 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4044 	else {
4045 		err = ext4_calculate_overhead(sb);
4046 		if (err)
4047 			goto failed_mount_wq;
4048 	}
4049 
4050 	/*
4051 	 * The maximum number of concurrent works can be high and
4052 	 * concurrency isn't really necessary.  Limit it to 1.
4053 	 */
4054 	EXT4_SB(sb)->rsv_conversion_wq =
4055 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4056 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4057 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4058 		ret = -ENOMEM;
4059 		goto failed_mount4;
4060 	}
4061 
4062 	/*
4063 	 * The jbd2_journal_load will have done any necessary log recovery,
4064 	 * so we can safely mount the rest of the filesystem now.
4065 	 */
4066 
4067 	root = ext4_iget(sb, EXT4_ROOT_INO);
4068 	if (IS_ERR(root)) {
4069 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4070 		ret = PTR_ERR(root);
4071 		root = NULL;
4072 		goto failed_mount4;
4073 	}
4074 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4075 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4076 		iput(root);
4077 		goto failed_mount4;
4078 	}
4079 	sb->s_root = d_make_root(root);
4080 	if (!sb->s_root) {
4081 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4082 		ret = -ENOMEM;
4083 		goto failed_mount4;
4084 	}
4085 
4086 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4087 		sb->s_flags |= MS_RDONLY;
4088 
4089 	/* determine the minimum size of new large inodes, if present */
4090 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4091 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4092 						     EXT4_GOOD_OLD_INODE_SIZE;
4093 		if (ext4_has_feature_extra_isize(sb)) {
4094 			if (sbi->s_want_extra_isize <
4095 			    le16_to_cpu(es->s_want_extra_isize))
4096 				sbi->s_want_extra_isize =
4097 					le16_to_cpu(es->s_want_extra_isize);
4098 			if (sbi->s_want_extra_isize <
4099 			    le16_to_cpu(es->s_min_extra_isize))
4100 				sbi->s_want_extra_isize =
4101 					le16_to_cpu(es->s_min_extra_isize);
4102 		}
4103 	}
4104 	/* Check if enough inode space is available */
4105 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4106 							sbi->s_inode_size) {
4107 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4108 						       EXT4_GOOD_OLD_INODE_SIZE;
4109 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4110 			 "available");
4111 	}
4112 
4113 	ext4_set_resv_clusters(sb);
4114 
4115 	err = ext4_setup_system_zone(sb);
4116 	if (err) {
4117 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4118 			 "zone (%d)", err);
4119 		goto failed_mount4a;
4120 	}
4121 
4122 	ext4_ext_init(sb);
4123 	err = ext4_mb_init(sb);
4124 	if (err) {
4125 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4126 			 err);
4127 		goto failed_mount5;
4128 	}
4129 
4130 	block = ext4_count_free_clusters(sb);
4131 	ext4_free_blocks_count_set(sbi->s_es,
4132 				   EXT4_C2B(sbi, block));
4133 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4134 				  GFP_KERNEL);
4135 	if (!err) {
4136 		unsigned long freei = ext4_count_free_inodes(sb);
4137 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4138 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4139 					  GFP_KERNEL);
4140 	}
4141 	if (!err)
4142 		err = percpu_counter_init(&sbi->s_dirs_counter,
4143 					  ext4_count_dirs(sb), GFP_KERNEL);
4144 	if (!err)
4145 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4146 					  GFP_KERNEL);
4147 	if (!err)
4148 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4149 
4150 	if (err) {
4151 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4152 		goto failed_mount6;
4153 	}
4154 
4155 	if (ext4_has_feature_flex_bg(sb))
4156 		if (!ext4_fill_flex_info(sb)) {
4157 			ext4_msg(sb, KERN_ERR,
4158 			       "unable to initialize "
4159 			       "flex_bg meta info!");
4160 			goto failed_mount6;
4161 		}
4162 
4163 	err = ext4_register_li_request(sb, first_not_zeroed);
4164 	if (err)
4165 		goto failed_mount6;
4166 
4167 	err = ext4_register_sysfs(sb);
4168 	if (err)
4169 		goto failed_mount7;
4170 
4171 #ifdef CONFIG_QUOTA
4172 	/* Enable quota usage during mount. */
4173 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4174 		err = ext4_enable_quotas(sb);
4175 		if (err)
4176 			goto failed_mount8;
4177 	}
4178 #endif  /* CONFIG_QUOTA */
4179 
4180 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4181 	ext4_orphan_cleanup(sb, es);
4182 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4183 	if (needs_recovery) {
4184 		ext4_msg(sb, KERN_INFO, "recovery complete");
4185 		ext4_mark_recovery_complete(sb, es);
4186 	}
4187 	if (EXT4_SB(sb)->s_journal) {
4188 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4189 			descr = " journalled data mode";
4190 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4191 			descr = " ordered data mode";
4192 		else
4193 			descr = " writeback data mode";
4194 	} else
4195 		descr = "out journal";
4196 
4197 	if (test_opt(sb, DISCARD)) {
4198 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4199 		if (!blk_queue_discard(q))
4200 			ext4_msg(sb, KERN_WARNING,
4201 				 "mounting with \"discard\" option, but "
4202 				 "the device does not support discard");
4203 	}
4204 
4205 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4206 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4207 			 "Opts: %.*s%s%s", descr,
4208 			 (int) sizeof(sbi->s_es->s_mount_opts),
4209 			 sbi->s_es->s_mount_opts,
4210 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4211 
4212 	if (es->s_error_count)
4213 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4214 
4215 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4216 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4217 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4218 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4219 
4220 	kfree(orig_data);
4221 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4222 	memcpy(sbi->key_prefix, EXT4_KEY_DESC_PREFIX,
4223 				EXT4_KEY_DESC_PREFIX_SIZE);
4224 	sbi->key_prefix_size = EXT4_KEY_DESC_PREFIX_SIZE;
4225 #endif
4226 	return 0;
4227 
4228 cantfind_ext4:
4229 	if (!silent)
4230 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4231 	goto failed_mount;
4232 
4233 #ifdef CONFIG_QUOTA
4234 failed_mount8:
4235 	ext4_unregister_sysfs(sb);
4236 #endif
4237 failed_mount7:
4238 	ext4_unregister_li_request(sb);
4239 failed_mount6:
4240 	ext4_mb_release(sb);
4241 	if (sbi->s_flex_groups)
4242 		kvfree(sbi->s_flex_groups);
4243 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4244 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4245 	percpu_counter_destroy(&sbi->s_dirs_counter);
4246 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4247 failed_mount5:
4248 	ext4_ext_release(sb);
4249 	ext4_release_system_zone(sb);
4250 failed_mount4a:
4251 	dput(sb->s_root);
4252 	sb->s_root = NULL;
4253 failed_mount4:
4254 	ext4_msg(sb, KERN_ERR, "mount failed");
4255 	if (EXT4_SB(sb)->rsv_conversion_wq)
4256 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4257 failed_mount_wq:
4258 	if (sbi->s_mb_cache) {
4259 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
4260 		sbi->s_mb_cache = NULL;
4261 	}
4262 	if (sbi->s_journal) {
4263 		jbd2_journal_destroy(sbi->s_journal);
4264 		sbi->s_journal = NULL;
4265 	}
4266 failed_mount3a:
4267 	ext4_es_unregister_shrinker(sbi);
4268 failed_mount3:
4269 	del_timer_sync(&sbi->s_err_report);
4270 	if (sbi->s_mmp_tsk)
4271 		kthread_stop(sbi->s_mmp_tsk);
4272 failed_mount2:
4273 	for (i = 0; i < db_count; i++)
4274 		brelse(sbi->s_group_desc[i]);
4275 	kvfree(sbi->s_group_desc);
4276 failed_mount:
4277 	if (sbi->s_chksum_driver)
4278 		crypto_free_shash(sbi->s_chksum_driver);
4279 #ifdef CONFIG_QUOTA
4280 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4281 		kfree(sbi->s_qf_names[i]);
4282 #endif
4283 	ext4_blkdev_remove(sbi);
4284 	brelse(bh);
4285 out_fail:
4286 	sb->s_fs_info = NULL;
4287 	kfree(sbi->s_blockgroup_lock);
4288 out_free_base:
4289 	kfree(sbi);
4290 	kfree(orig_data);
4291 	return err ? err : ret;
4292 }
4293 
4294 /*
4295  * Setup any per-fs journal parameters now.  We'll do this both on
4296  * initial mount, once the journal has been initialised but before we've
4297  * done any recovery; and again on any subsequent remount.
4298  */
4299 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4300 {
4301 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4302 
4303 	journal->j_commit_interval = sbi->s_commit_interval;
4304 	journal->j_min_batch_time = sbi->s_min_batch_time;
4305 	journal->j_max_batch_time = sbi->s_max_batch_time;
4306 
4307 	write_lock(&journal->j_state_lock);
4308 	if (test_opt(sb, BARRIER))
4309 		journal->j_flags |= JBD2_BARRIER;
4310 	else
4311 		journal->j_flags &= ~JBD2_BARRIER;
4312 	if (test_opt(sb, DATA_ERR_ABORT))
4313 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4314 	else
4315 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4316 	write_unlock(&journal->j_state_lock);
4317 }
4318 
4319 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4320 					     unsigned int journal_inum)
4321 {
4322 	struct inode *journal_inode;
4323 
4324 	/*
4325 	 * Test for the existence of a valid inode on disk.  Bad things
4326 	 * happen if we iget() an unused inode, as the subsequent iput()
4327 	 * will try to delete it.
4328 	 */
4329 	journal_inode = ext4_iget(sb, journal_inum);
4330 	if (IS_ERR(journal_inode)) {
4331 		ext4_msg(sb, KERN_ERR, "no journal found");
4332 		return NULL;
4333 	}
4334 	if (!journal_inode->i_nlink) {
4335 		make_bad_inode(journal_inode);
4336 		iput(journal_inode);
4337 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4338 		return NULL;
4339 	}
4340 
4341 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4342 		  journal_inode, journal_inode->i_size);
4343 	if (!S_ISREG(journal_inode->i_mode)) {
4344 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4345 		iput(journal_inode);
4346 		return NULL;
4347 	}
4348 	return journal_inode;
4349 }
4350 
4351 static journal_t *ext4_get_journal(struct super_block *sb,
4352 				   unsigned int journal_inum)
4353 {
4354 	struct inode *journal_inode;
4355 	journal_t *journal;
4356 
4357 	BUG_ON(!ext4_has_feature_journal(sb));
4358 
4359 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4360 	if (!journal_inode)
4361 		return NULL;
4362 
4363 	journal = jbd2_journal_init_inode(journal_inode);
4364 	if (!journal) {
4365 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4366 		iput(journal_inode);
4367 		return NULL;
4368 	}
4369 	journal->j_private = sb;
4370 	ext4_init_journal_params(sb, journal);
4371 	return journal;
4372 }
4373 
4374 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4375 				       dev_t j_dev)
4376 {
4377 	struct buffer_head *bh;
4378 	journal_t *journal;
4379 	ext4_fsblk_t start;
4380 	ext4_fsblk_t len;
4381 	int hblock, blocksize;
4382 	ext4_fsblk_t sb_block;
4383 	unsigned long offset;
4384 	struct ext4_super_block *es;
4385 	struct block_device *bdev;
4386 
4387 	BUG_ON(!ext4_has_feature_journal(sb));
4388 
4389 	bdev = ext4_blkdev_get(j_dev, sb);
4390 	if (bdev == NULL)
4391 		return NULL;
4392 
4393 	blocksize = sb->s_blocksize;
4394 	hblock = bdev_logical_block_size(bdev);
4395 	if (blocksize < hblock) {
4396 		ext4_msg(sb, KERN_ERR,
4397 			"blocksize too small for journal device");
4398 		goto out_bdev;
4399 	}
4400 
4401 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4402 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4403 	set_blocksize(bdev, blocksize);
4404 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4405 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4406 		       "external journal");
4407 		goto out_bdev;
4408 	}
4409 
4410 	es = (struct ext4_super_block *) (bh->b_data + offset);
4411 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4412 	    !(le32_to_cpu(es->s_feature_incompat) &
4413 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4414 		ext4_msg(sb, KERN_ERR, "external journal has "
4415 					"bad superblock");
4416 		brelse(bh);
4417 		goto out_bdev;
4418 	}
4419 
4420 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4421 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4422 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4423 		ext4_msg(sb, KERN_ERR, "external journal has "
4424 				       "corrupt superblock");
4425 		brelse(bh);
4426 		goto out_bdev;
4427 	}
4428 
4429 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4430 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4431 		brelse(bh);
4432 		goto out_bdev;
4433 	}
4434 
4435 	len = ext4_blocks_count(es);
4436 	start = sb_block + 1;
4437 	brelse(bh);	/* we're done with the superblock */
4438 
4439 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4440 					start, len, blocksize);
4441 	if (!journal) {
4442 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4443 		goto out_bdev;
4444 	}
4445 	journal->j_private = sb;
4446 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4447 	wait_on_buffer(journal->j_sb_buffer);
4448 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4449 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4450 		goto out_journal;
4451 	}
4452 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4453 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4454 					"user (unsupported) - %d",
4455 			be32_to_cpu(journal->j_superblock->s_nr_users));
4456 		goto out_journal;
4457 	}
4458 	EXT4_SB(sb)->journal_bdev = bdev;
4459 	ext4_init_journal_params(sb, journal);
4460 	return journal;
4461 
4462 out_journal:
4463 	jbd2_journal_destroy(journal);
4464 out_bdev:
4465 	ext4_blkdev_put(bdev);
4466 	return NULL;
4467 }
4468 
4469 static int ext4_load_journal(struct super_block *sb,
4470 			     struct ext4_super_block *es,
4471 			     unsigned long journal_devnum)
4472 {
4473 	journal_t *journal;
4474 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4475 	dev_t journal_dev;
4476 	int err = 0;
4477 	int really_read_only;
4478 
4479 	BUG_ON(!ext4_has_feature_journal(sb));
4480 
4481 	if (journal_devnum &&
4482 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4483 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4484 			"numbers have changed");
4485 		journal_dev = new_decode_dev(journal_devnum);
4486 	} else
4487 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4488 
4489 	really_read_only = bdev_read_only(sb->s_bdev);
4490 
4491 	/*
4492 	 * Are we loading a blank journal or performing recovery after a
4493 	 * crash?  For recovery, we need to check in advance whether we
4494 	 * can get read-write access to the device.
4495 	 */
4496 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4497 		if (sb->s_flags & MS_RDONLY) {
4498 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4499 					"required on readonly filesystem");
4500 			if (really_read_only) {
4501 				ext4_msg(sb, KERN_ERR, "write access "
4502 					"unavailable, cannot proceed");
4503 				return -EROFS;
4504 			}
4505 			ext4_msg(sb, KERN_INFO, "write access will "
4506 			       "be enabled during recovery");
4507 		}
4508 	}
4509 
4510 	if (journal_inum && journal_dev) {
4511 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4512 		       "and inode journals!");
4513 		return -EINVAL;
4514 	}
4515 
4516 	if (journal_inum) {
4517 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4518 			return -EINVAL;
4519 	} else {
4520 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4521 			return -EINVAL;
4522 	}
4523 
4524 	if (!(journal->j_flags & JBD2_BARRIER))
4525 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4526 
4527 	if (!ext4_has_feature_journal_needs_recovery(sb))
4528 		err = jbd2_journal_wipe(journal, !really_read_only);
4529 	if (!err) {
4530 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4531 		if (save)
4532 			memcpy(save, ((char *) es) +
4533 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4534 		err = jbd2_journal_load(journal);
4535 		if (save)
4536 			memcpy(((char *) es) + EXT4_S_ERR_START,
4537 			       save, EXT4_S_ERR_LEN);
4538 		kfree(save);
4539 	}
4540 
4541 	if (err) {
4542 		ext4_msg(sb, KERN_ERR, "error loading journal");
4543 		jbd2_journal_destroy(journal);
4544 		return err;
4545 	}
4546 
4547 	EXT4_SB(sb)->s_journal = journal;
4548 	ext4_clear_journal_err(sb, es);
4549 
4550 	if (!really_read_only && journal_devnum &&
4551 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4552 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4553 
4554 		/* Make sure we flush the recovery flag to disk. */
4555 		ext4_commit_super(sb, 1);
4556 	}
4557 
4558 	return 0;
4559 }
4560 
4561 static int ext4_commit_super(struct super_block *sb, int sync)
4562 {
4563 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4564 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4565 	int error = 0;
4566 
4567 	if (!sbh || block_device_ejected(sb))
4568 		return error;
4569 	/*
4570 	 * If the file system is mounted read-only, don't update the
4571 	 * superblock write time.  This avoids updating the superblock
4572 	 * write time when we are mounting the root file system
4573 	 * read/only but we need to replay the journal; at that point,
4574 	 * for people who are east of GMT and who make their clock
4575 	 * tick in localtime for Windows bug-for-bug compatibility,
4576 	 * the clock is set in the future, and this will cause e2fsck
4577 	 * to complain and force a full file system check.
4578 	 */
4579 	if (!(sb->s_flags & MS_RDONLY))
4580 		es->s_wtime = cpu_to_le32(get_seconds());
4581 	if (sb->s_bdev->bd_part)
4582 		es->s_kbytes_written =
4583 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4584 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4585 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4586 	else
4587 		es->s_kbytes_written =
4588 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4589 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4590 		ext4_free_blocks_count_set(es,
4591 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4592 				&EXT4_SB(sb)->s_freeclusters_counter)));
4593 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4594 		es->s_free_inodes_count =
4595 			cpu_to_le32(percpu_counter_sum_positive(
4596 				&EXT4_SB(sb)->s_freeinodes_counter));
4597 	BUFFER_TRACE(sbh, "marking dirty");
4598 	ext4_superblock_csum_set(sb);
4599 	if (sync)
4600 		lock_buffer(sbh);
4601 	if (buffer_write_io_error(sbh)) {
4602 		/*
4603 		 * Oh, dear.  A previous attempt to write the
4604 		 * superblock failed.  This could happen because the
4605 		 * USB device was yanked out.  Or it could happen to
4606 		 * be a transient write error and maybe the block will
4607 		 * be remapped.  Nothing we can do but to retry the
4608 		 * write and hope for the best.
4609 		 */
4610 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4611 		       "superblock detected");
4612 		clear_buffer_write_io_error(sbh);
4613 		set_buffer_uptodate(sbh);
4614 	}
4615 	mark_buffer_dirty(sbh);
4616 	if (sync) {
4617 		unlock_buffer(sbh);
4618 		error = __sync_dirty_buffer(sbh,
4619 			test_opt(sb, BARRIER) ? REQ_FUA : REQ_SYNC);
4620 		if (error)
4621 			return error;
4622 
4623 		error = buffer_write_io_error(sbh);
4624 		if (error) {
4625 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4626 			       "superblock");
4627 			clear_buffer_write_io_error(sbh);
4628 			set_buffer_uptodate(sbh);
4629 		}
4630 	}
4631 	return error;
4632 }
4633 
4634 /*
4635  * Have we just finished recovery?  If so, and if we are mounting (or
4636  * remounting) the filesystem readonly, then we will end up with a
4637  * consistent fs on disk.  Record that fact.
4638  */
4639 static void ext4_mark_recovery_complete(struct super_block *sb,
4640 					struct ext4_super_block *es)
4641 {
4642 	journal_t *journal = EXT4_SB(sb)->s_journal;
4643 
4644 	if (!ext4_has_feature_journal(sb)) {
4645 		BUG_ON(journal != NULL);
4646 		return;
4647 	}
4648 	jbd2_journal_lock_updates(journal);
4649 	if (jbd2_journal_flush(journal) < 0)
4650 		goto out;
4651 
4652 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4653 	    sb->s_flags & MS_RDONLY) {
4654 		ext4_clear_feature_journal_needs_recovery(sb);
4655 		ext4_commit_super(sb, 1);
4656 	}
4657 
4658 out:
4659 	jbd2_journal_unlock_updates(journal);
4660 }
4661 
4662 /*
4663  * If we are mounting (or read-write remounting) a filesystem whose journal
4664  * has recorded an error from a previous lifetime, move that error to the
4665  * main filesystem now.
4666  */
4667 static void ext4_clear_journal_err(struct super_block *sb,
4668 				   struct ext4_super_block *es)
4669 {
4670 	journal_t *journal;
4671 	int j_errno;
4672 	const char *errstr;
4673 
4674 	BUG_ON(!ext4_has_feature_journal(sb));
4675 
4676 	journal = EXT4_SB(sb)->s_journal;
4677 
4678 	/*
4679 	 * Now check for any error status which may have been recorded in the
4680 	 * journal by a prior ext4_error() or ext4_abort()
4681 	 */
4682 
4683 	j_errno = jbd2_journal_errno(journal);
4684 	if (j_errno) {
4685 		char nbuf[16];
4686 
4687 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4688 		ext4_warning(sb, "Filesystem error recorded "
4689 			     "from previous mount: %s", errstr);
4690 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4691 
4692 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4693 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4694 		ext4_commit_super(sb, 1);
4695 
4696 		jbd2_journal_clear_err(journal);
4697 		jbd2_journal_update_sb_errno(journal);
4698 	}
4699 }
4700 
4701 /*
4702  * Force the running and committing transactions to commit,
4703  * and wait on the commit.
4704  */
4705 int ext4_force_commit(struct super_block *sb)
4706 {
4707 	journal_t *journal;
4708 
4709 	if (sb->s_flags & MS_RDONLY)
4710 		return 0;
4711 
4712 	journal = EXT4_SB(sb)->s_journal;
4713 	return ext4_journal_force_commit(journal);
4714 }
4715 
4716 static int ext4_sync_fs(struct super_block *sb, int wait)
4717 {
4718 	int ret = 0;
4719 	tid_t target;
4720 	bool needs_barrier = false;
4721 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4722 
4723 	trace_ext4_sync_fs(sb, wait);
4724 	flush_workqueue(sbi->rsv_conversion_wq);
4725 	/*
4726 	 * Writeback quota in non-journalled quota case - journalled quota has
4727 	 * no dirty dquots
4728 	 */
4729 	dquot_writeback_dquots(sb, -1);
4730 	/*
4731 	 * Data writeback is possible w/o journal transaction, so barrier must
4732 	 * being sent at the end of the function. But we can skip it if
4733 	 * transaction_commit will do it for us.
4734 	 */
4735 	if (sbi->s_journal) {
4736 		target = jbd2_get_latest_transaction(sbi->s_journal);
4737 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4738 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4739 			needs_barrier = true;
4740 
4741 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4742 			if (wait)
4743 				ret = jbd2_log_wait_commit(sbi->s_journal,
4744 							   target);
4745 		}
4746 	} else if (wait && test_opt(sb, BARRIER))
4747 		needs_barrier = true;
4748 	if (needs_barrier) {
4749 		int err;
4750 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4751 		if (!ret)
4752 			ret = err;
4753 	}
4754 
4755 	return ret;
4756 }
4757 
4758 /*
4759  * LVM calls this function before a (read-only) snapshot is created.  This
4760  * gives us a chance to flush the journal completely and mark the fs clean.
4761  *
4762  * Note that only this function cannot bring a filesystem to be in a clean
4763  * state independently. It relies on upper layer to stop all data & metadata
4764  * modifications.
4765  */
4766 static int ext4_freeze(struct super_block *sb)
4767 {
4768 	int error = 0;
4769 	journal_t *journal;
4770 
4771 	if (sb->s_flags & MS_RDONLY)
4772 		return 0;
4773 
4774 	journal = EXT4_SB(sb)->s_journal;
4775 
4776 	if (journal) {
4777 		/* Now we set up the journal barrier. */
4778 		jbd2_journal_lock_updates(journal);
4779 
4780 		/*
4781 		 * Don't clear the needs_recovery flag if we failed to
4782 		 * flush the journal.
4783 		 */
4784 		error = jbd2_journal_flush(journal);
4785 		if (error < 0)
4786 			goto out;
4787 
4788 		/* Journal blocked and flushed, clear needs_recovery flag. */
4789 		ext4_clear_feature_journal_needs_recovery(sb);
4790 	}
4791 
4792 	error = ext4_commit_super(sb, 1);
4793 out:
4794 	if (journal)
4795 		/* we rely on upper layer to stop further updates */
4796 		jbd2_journal_unlock_updates(journal);
4797 	return error;
4798 }
4799 
4800 /*
4801  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4802  * flag here, even though the filesystem is not technically dirty yet.
4803  */
4804 static int ext4_unfreeze(struct super_block *sb)
4805 {
4806 	if (sb->s_flags & MS_RDONLY)
4807 		return 0;
4808 
4809 	if (EXT4_SB(sb)->s_journal) {
4810 		/* Reset the needs_recovery flag before the fs is unlocked. */
4811 		ext4_set_feature_journal_needs_recovery(sb);
4812 	}
4813 
4814 	ext4_commit_super(sb, 1);
4815 	return 0;
4816 }
4817 
4818 /*
4819  * Structure to save mount options for ext4_remount's benefit
4820  */
4821 struct ext4_mount_options {
4822 	unsigned long s_mount_opt;
4823 	unsigned long s_mount_opt2;
4824 	kuid_t s_resuid;
4825 	kgid_t s_resgid;
4826 	unsigned long s_commit_interval;
4827 	u32 s_min_batch_time, s_max_batch_time;
4828 #ifdef CONFIG_QUOTA
4829 	int s_jquota_fmt;
4830 	char *s_qf_names[EXT4_MAXQUOTAS];
4831 #endif
4832 };
4833 
4834 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4835 {
4836 	struct ext4_super_block *es;
4837 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4838 	unsigned long old_sb_flags;
4839 	struct ext4_mount_options old_opts;
4840 	int enable_quota = 0;
4841 	ext4_group_t g;
4842 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4843 	int err = 0;
4844 #ifdef CONFIG_QUOTA
4845 	int i, j;
4846 #endif
4847 	char *orig_data = kstrdup(data, GFP_KERNEL);
4848 
4849 	/* Store the original options */
4850 	old_sb_flags = sb->s_flags;
4851 	old_opts.s_mount_opt = sbi->s_mount_opt;
4852 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4853 	old_opts.s_resuid = sbi->s_resuid;
4854 	old_opts.s_resgid = sbi->s_resgid;
4855 	old_opts.s_commit_interval = sbi->s_commit_interval;
4856 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4857 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4858 #ifdef CONFIG_QUOTA
4859 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4860 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4861 		if (sbi->s_qf_names[i]) {
4862 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4863 							 GFP_KERNEL);
4864 			if (!old_opts.s_qf_names[i]) {
4865 				for (j = 0; j < i; j++)
4866 					kfree(old_opts.s_qf_names[j]);
4867 				kfree(orig_data);
4868 				return -ENOMEM;
4869 			}
4870 		} else
4871 			old_opts.s_qf_names[i] = NULL;
4872 #endif
4873 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4874 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4875 
4876 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4877 		err = -EINVAL;
4878 		goto restore_opts;
4879 	}
4880 
4881 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4882 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4883 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4884 			 "during remount not supported; ignoring");
4885 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4886 	}
4887 
4888 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4889 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4890 			ext4_msg(sb, KERN_ERR, "can't mount with "
4891 				 "both data=journal and delalloc");
4892 			err = -EINVAL;
4893 			goto restore_opts;
4894 		}
4895 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4896 			ext4_msg(sb, KERN_ERR, "can't mount with "
4897 				 "both data=journal and dioread_nolock");
4898 			err = -EINVAL;
4899 			goto restore_opts;
4900 		}
4901 		if (test_opt(sb, DAX)) {
4902 			ext4_msg(sb, KERN_ERR, "can't mount with "
4903 				 "both data=journal and dax");
4904 			err = -EINVAL;
4905 			goto restore_opts;
4906 		}
4907 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
4908 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4909 			ext4_msg(sb, KERN_ERR, "can't mount with "
4910 				"journal_async_commit in data=ordered mode");
4911 			err = -EINVAL;
4912 			goto restore_opts;
4913 		}
4914 	}
4915 
4916 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4917 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4918 			"dax flag with busy inodes while remounting");
4919 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4920 	}
4921 
4922 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4923 		ext4_abort(sb, "Abort forced by user");
4924 
4925 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4926 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4927 
4928 	es = sbi->s_es;
4929 
4930 	if (sbi->s_journal) {
4931 		ext4_init_journal_params(sb, sbi->s_journal);
4932 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4933 	}
4934 
4935 	if (*flags & MS_LAZYTIME)
4936 		sb->s_flags |= MS_LAZYTIME;
4937 
4938 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4939 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4940 			err = -EROFS;
4941 			goto restore_opts;
4942 		}
4943 
4944 		if (*flags & MS_RDONLY) {
4945 			err = sync_filesystem(sb);
4946 			if (err < 0)
4947 				goto restore_opts;
4948 			err = dquot_suspend(sb, -1);
4949 			if (err < 0)
4950 				goto restore_opts;
4951 
4952 			/*
4953 			 * First of all, the unconditional stuff we have to do
4954 			 * to disable replay of the journal when we next remount
4955 			 */
4956 			sb->s_flags |= MS_RDONLY;
4957 
4958 			/*
4959 			 * OK, test if we are remounting a valid rw partition
4960 			 * readonly, and if so set the rdonly flag and then
4961 			 * mark the partition as valid again.
4962 			 */
4963 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4964 			    (sbi->s_mount_state & EXT4_VALID_FS))
4965 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4966 
4967 			if (sbi->s_journal)
4968 				ext4_mark_recovery_complete(sb, es);
4969 		} else {
4970 			/* Make sure we can mount this feature set readwrite */
4971 			if (ext4_has_feature_readonly(sb) ||
4972 			    !ext4_feature_set_ok(sb, 0)) {
4973 				err = -EROFS;
4974 				goto restore_opts;
4975 			}
4976 			/*
4977 			 * Make sure the group descriptor checksums
4978 			 * are sane.  If they aren't, refuse to remount r/w.
4979 			 */
4980 			for (g = 0; g < sbi->s_groups_count; g++) {
4981 				struct ext4_group_desc *gdp =
4982 					ext4_get_group_desc(sb, g, NULL);
4983 
4984 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4985 					ext4_msg(sb, KERN_ERR,
4986 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4987 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4988 					       le16_to_cpu(gdp->bg_checksum));
4989 					err = -EFSBADCRC;
4990 					goto restore_opts;
4991 				}
4992 			}
4993 
4994 			/*
4995 			 * If we have an unprocessed orphan list hanging
4996 			 * around from a previously readonly bdev mount,
4997 			 * require a full umount/remount for now.
4998 			 */
4999 			if (es->s_last_orphan) {
5000 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5001 				       "remount RDWR because of unprocessed "
5002 				       "orphan inode list.  Please "
5003 				       "umount/remount instead");
5004 				err = -EINVAL;
5005 				goto restore_opts;
5006 			}
5007 
5008 			/*
5009 			 * Mounting a RDONLY partition read-write, so reread
5010 			 * and store the current valid flag.  (It may have
5011 			 * been changed by e2fsck since we originally mounted
5012 			 * the partition.)
5013 			 */
5014 			if (sbi->s_journal)
5015 				ext4_clear_journal_err(sb, es);
5016 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5017 			if (!ext4_setup_super(sb, es, 0))
5018 				sb->s_flags &= ~MS_RDONLY;
5019 			if (ext4_has_feature_mmp(sb))
5020 				if (ext4_multi_mount_protect(sb,
5021 						le64_to_cpu(es->s_mmp_block))) {
5022 					err = -EROFS;
5023 					goto restore_opts;
5024 				}
5025 			enable_quota = 1;
5026 		}
5027 	}
5028 
5029 	/*
5030 	 * Reinitialize lazy itable initialization thread based on
5031 	 * current settings
5032 	 */
5033 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5034 		ext4_unregister_li_request(sb);
5035 	else {
5036 		ext4_group_t first_not_zeroed;
5037 		first_not_zeroed = ext4_has_uninit_itable(sb);
5038 		ext4_register_li_request(sb, first_not_zeroed);
5039 	}
5040 
5041 	ext4_setup_system_zone(sb);
5042 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5043 		ext4_commit_super(sb, 1);
5044 
5045 #ifdef CONFIG_QUOTA
5046 	/* Release old quota file names */
5047 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5048 		kfree(old_opts.s_qf_names[i]);
5049 	if (enable_quota) {
5050 		if (sb_any_quota_suspended(sb))
5051 			dquot_resume(sb, -1);
5052 		else if (ext4_has_feature_quota(sb)) {
5053 			err = ext4_enable_quotas(sb);
5054 			if (err)
5055 				goto restore_opts;
5056 		}
5057 	}
5058 #endif
5059 
5060 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5061 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5062 	kfree(orig_data);
5063 	return 0;
5064 
5065 restore_opts:
5066 	sb->s_flags = old_sb_flags;
5067 	sbi->s_mount_opt = old_opts.s_mount_opt;
5068 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5069 	sbi->s_resuid = old_opts.s_resuid;
5070 	sbi->s_resgid = old_opts.s_resgid;
5071 	sbi->s_commit_interval = old_opts.s_commit_interval;
5072 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5073 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5074 #ifdef CONFIG_QUOTA
5075 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5076 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5077 		kfree(sbi->s_qf_names[i]);
5078 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5079 	}
5080 #endif
5081 	kfree(orig_data);
5082 	return err;
5083 }
5084 
5085 #ifdef CONFIG_QUOTA
5086 static int ext4_statfs_project(struct super_block *sb,
5087 			       kprojid_t projid, struct kstatfs *buf)
5088 {
5089 	struct kqid qid;
5090 	struct dquot *dquot;
5091 	u64 limit;
5092 	u64 curblock;
5093 
5094 	qid = make_kqid_projid(projid);
5095 	dquot = dqget(sb, qid);
5096 	if (IS_ERR(dquot))
5097 		return PTR_ERR(dquot);
5098 	spin_lock(&dq_data_lock);
5099 
5100 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5101 		 dquot->dq_dqb.dqb_bsoftlimit :
5102 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5103 	if (limit && buf->f_blocks > limit) {
5104 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5105 		buf->f_blocks = limit;
5106 		buf->f_bfree = buf->f_bavail =
5107 			(buf->f_blocks > curblock) ?
5108 			 (buf->f_blocks - curblock) : 0;
5109 	}
5110 
5111 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5112 		dquot->dq_dqb.dqb_isoftlimit :
5113 		dquot->dq_dqb.dqb_ihardlimit;
5114 	if (limit && buf->f_files > limit) {
5115 		buf->f_files = limit;
5116 		buf->f_ffree =
5117 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5118 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5119 	}
5120 
5121 	spin_unlock(&dq_data_lock);
5122 	dqput(dquot);
5123 	return 0;
5124 }
5125 #endif
5126 
5127 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5128 {
5129 	struct super_block *sb = dentry->d_sb;
5130 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5131 	struct ext4_super_block *es = sbi->s_es;
5132 	ext4_fsblk_t overhead = 0, resv_blocks;
5133 	u64 fsid;
5134 	s64 bfree;
5135 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5136 
5137 	if (!test_opt(sb, MINIX_DF))
5138 		overhead = sbi->s_overhead;
5139 
5140 	buf->f_type = EXT4_SUPER_MAGIC;
5141 	buf->f_bsize = sb->s_blocksize;
5142 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5143 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5144 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5145 	/* prevent underflow in case that few free space is available */
5146 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5147 	buf->f_bavail = buf->f_bfree -
5148 			(ext4_r_blocks_count(es) + resv_blocks);
5149 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5150 		buf->f_bavail = 0;
5151 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5152 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5153 	buf->f_namelen = EXT4_NAME_LEN;
5154 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5155 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5156 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5157 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5158 
5159 #ifdef CONFIG_QUOTA
5160 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5161 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5162 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5163 #endif
5164 	return 0;
5165 }
5166 
5167 /* Helper function for writing quotas on sync - we need to start transaction
5168  * before quota file is locked for write. Otherwise the are possible deadlocks:
5169  * Process 1                         Process 2
5170  * ext4_create()                     quota_sync()
5171  *   jbd2_journal_start()                  write_dquot()
5172  *   dquot_initialize()                         down(dqio_mutex)
5173  *     down(dqio_mutex)                    jbd2_journal_start()
5174  *
5175  */
5176 
5177 #ifdef CONFIG_QUOTA
5178 
5179 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5180 {
5181 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5182 }
5183 
5184 static int ext4_write_dquot(struct dquot *dquot)
5185 {
5186 	int ret, err;
5187 	handle_t *handle;
5188 	struct inode *inode;
5189 
5190 	inode = dquot_to_inode(dquot);
5191 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5192 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5193 	if (IS_ERR(handle))
5194 		return PTR_ERR(handle);
5195 	ret = dquot_commit(dquot);
5196 	err = ext4_journal_stop(handle);
5197 	if (!ret)
5198 		ret = err;
5199 	return ret;
5200 }
5201 
5202 static int ext4_acquire_dquot(struct dquot *dquot)
5203 {
5204 	int ret, err;
5205 	handle_t *handle;
5206 
5207 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5208 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5209 	if (IS_ERR(handle))
5210 		return PTR_ERR(handle);
5211 	ret = dquot_acquire(dquot);
5212 	err = ext4_journal_stop(handle);
5213 	if (!ret)
5214 		ret = err;
5215 	return ret;
5216 }
5217 
5218 static int ext4_release_dquot(struct dquot *dquot)
5219 {
5220 	int ret, err;
5221 	handle_t *handle;
5222 
5223 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5224 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5225 	if (IS_ERR(handle)) {
5226 		/* Release dquot anyway to avoid endless cycle in dqput() */
5227 		dquot_release(dquot);
5228 		return PTR_ERR(handle);
5229 	}
5230 	ret = dquot_release(dquot);
5231 	err = ext4_journal_stop(handle);
5232 	if (!ret)
5233 		ret = err;
5234 	return ret;
5235 }
5236 
5237 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5238 {
5239 	struct super_block *sb = dquot->dq_sb;
5240 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5241 
5242 	/* Are we journaling quotas? */
5243 	if (ext4_has_feature_quota(sb) ||
5244 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5245 		dquot_mark_dquot_dirty(dquot);
5246 		return ext4_write_dquot(dquot);
5247 	} else {
5248 		return dquot_mark_dquot_dirty(dquot);
5249 	}
5250 }
5251 
5252 static int ext4_write_info(struct super_block *sb, int type)
5253 {
5254 	int ret, err;
5255 	handle_t *handle;
5256 
5257 	/* Data block + inode block */
5258 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5259 	if (IS_ERR(handle))
5260 		return PTR_ERR(handle);
5261 	ret = dquot_commit_info(sb, type);
5262 	err = ext4_journal_stop(handle);
5263 	if (!ret)
5264 		ret = err;
5265 	return ret;
5266 }
5267 
5268 /*
5269  * Turn on quotas during mount time - we need to find
5270  * the quota file and such...
5271  */
5272 static int ext4_quota_on_mount(struct super_block *sb, int type)
5273 {
5274 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5275 					EXT4_SB(sb)->s_jquota_fmt, type);
5276 }
5277 
5278 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5279 {
5280 	struct ext4_inode_info *ei = EXT4_I(inode);
5281 
5282 	/* The first argument of lockdep_set_subclass has to be
5283 	 * *exactly* the same as the argument to init_rwsem() --- in
5284 	 * this case, in init_once() --- or lockdep gets unhappy
5285 	 * because the name of the lock is set using the
5286 	 * stringification of the argument to init_rwsem().
5287 	 */
5288 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5289 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5290 }
5291 
5292 /*
5293  * Standard function to be called on quota_on
5294  */
5295 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5296 			 const struct path *path)
5297 {
5298 	int err;
5299 
5300 	if (!test_opt(sb, QUOTA))
5301 		return -EINVAL;
5302 
5303 	/* Quotafile not on the same filesystem? */
5304 	if (path->dentry->d_sb != sb)
5305 		return -EXDEV;
5306 	/* Journaling quota? */
5307 	if (EXT4_SB(sb)->s_qf_names[type]) {
5308 		/* Quotafile not in fs root? */
5309 		if (path->dentry->d_parent != sb->s_root)
5310 			ext4_msg(sb, KERN_WARNING,
5311 				"Quota file not on filesystem root. "
5312 				"Journaled quota will not work");
5313 	}
5314 
5315 	/*
5316 	 * When we journal data on quota file, we have to flush journal to see
5317 	 * all updates to the file when we bypass pagecache...
5318 	 */
5319 	if (EXT4_SB(sb)->s_journal &&
5320 	    ext4_should_journal_data(d_inode(path->dentry))) {
5321 		/*
5322 		 * We don't need to lock updates but journal_flush() could
5323 		 * otherwise be livelocked...
5324 		 */
5325 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5326 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5327 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5328 		if (err)
5329 			return err;
5330 	}
5331 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5332 	err = dquot_quota_on(sb, type, format_id, path);
5333 	if (err)
5334 		lockdep_set_quota_inode(path->dentry->d_inode,
5335 					     I_DATA_SEM_NORMAL);
5336 	return err;
5337 }
5338 
5339 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5340 			     unsigned int flags)
5341 {
5342 	int err;
5343 	struct inode *qf_inode;
5344 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5345 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5346 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5347 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5348 	};
5349 
5350 	BUG_ON(!ext4_has_feature_quota(sb));
5351 
5352 	if (!qf_inums[type])
5353 		return -EPERM;
5354 
5355 	qf_inode = ext4_iget(sb, qf_inums[type]);
5356 	if (IS_ERR(qf_inode)) {
5357 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5358 		return PTR_ERR(qf_inode);
5359 	}
5360 
5361 	/* Don't account quota for quota files to avoid recursion */
5362 	qf_inode->i_flags |= S_NOQUOTA;
5363 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5364 	err = dquot_enable(qf_inode, type, format_id, flags);
5365 	iput(qf_inode);
5366 	if (err)
5367 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5368 
5369 	return err;
5370 }
5371 
5372 /* Enable usage tracking for all quota types. */
5373 static int ext4_enable_quotas(struct super_block *sb)
5374 {
5375 	int type, err = 0;
5376 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5377 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5378 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5379 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5380 	};
5381 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5382 		test_opt(sb, USRQUOTA),
5383 		test_opt(sb, GRPQUOTA),
5384 		test_opt(sb, PRJQUOTA),
5385 	};
5386 
5387 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5388 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5389 		if (qf_inums[type]) {
5390 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5391 				DQUOT_USAGE_ENABLED |
5392 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5393 			if (err) {
5394 				ext4_warning(sb,
5395 					"Failed to enable quota tracking "
5396 					"(type=%d, err=%d). Please run "
5397 					"e2fsck to fix.", type, err);
5398 				return err;
5399 			}
5400 		}
5401 	}
5402 	return 0;
5403 }
5404 
5405 static int ext4_quota_off(struct super_block *sb, int type)
5406 {
5407 	struct inode *inode = sb_dqopt(sb)->files[type];
5408 	handle_t *handle;
5409 
5410 	/* Force all delayed allocation blocks to be allocated.
5411 	 * Caller already holds s_umount sem */
5412 	if (test_opt(sb, DELALLOC))
5413 		sync_filesystem(sb);
5414 
5415 	if (!inode)
5416 		goto out;
5417 
5418 	/* Update modification times of quota files when userspace can
5419 	 * start looking at them */
5420 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5421 	if (IS_ERR(handle))
5422 		goto out;
5423 	inode->i_mtime = inode->i_ctime = current_time(inode);
5424 	ext4_mark_inode_dirty(handle, inode);
5425 	ext4_journal_stop(handle);
5426 
5427 out:
5428 	return dquot_quota_off(sb, type);
5429 }
5430 
5431 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5432  * acquiring the locks... As quota files are never truncated and quota code
5433  * itself serializes the operations (and no one else should touch the files)
5434  * we don't have to be afraid of races */
5435 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5436 			       size_t len, loff_t off)
5437 {
5438 	struct inode *inode = sb_dqopt(sb)->files[type];
5439 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5440 	int offset = off & (sb->s_blocksize - 1);
5441 	int tocopy;
5442 	size_t toread;
5443 	struct buffer_head *bh;
5444 	loff_t i_size = i_size_read(inode);
5445 
5446 	if (off > i_size)
5447 		return 0;
5448 	if (off+len > i_size)
5449 		len = i_size-off;
5450 	toread = len;
5451 	while (toread > 0) {
5452 		tocopy = sb->s_blocksize - offset < toread ?
5453 				sb->s_blocksize - offset : toread;
5454 		bh = ext4_bread(NULL, inode, blk, 0);
5455 		if (IS_ERR(bh))
5456 			return PTR_ERR(bh);
5457 		if (!bh)	/* A hole? */
5458 			memset(data, 0, tocopy);
5459 		else
5460 			memcpy(data, bh->b_data+offset, tocopy);
5461 		brelse(bh);
5462 		offset = 0;
5463 		toread -= tocopy;
5464 		data += tocopy;
5465 		blk++;
5466 	}
5467 	return len;
5468 }
5469 
5470 /* Write to quotafile (we know the transaction is already started and has
5471  * enough credits) */
5472 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5473 				const char *data, size_t len, loff_t off)
5474 {
5475 	struct inode *inode = sb_dqopt(sb)->files[type];
5476 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5477 	int err, offset = off & (sb->s_blocksize - 1);
5478 	int retries = 0;
5479 	struct buffer_head *bh;
5480 	handle_t *handle = journal_current_handle();
5481 
5482 	if (EXT4_SB(sb)->s_journal && !handle) {
5483 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5484 			" cancelled because transaction is not started",
5485 			(unsigned long long)off, (unsigned long long)len);
5486 		return -EIO;
5487 	}
5488 	/*
5489 	 * Since we account only one data block in transaction credits,
5490 	 * then it is impossible to cross a block boundary.
5491 	 */
5492 	if (sb->s_blocksize - offset < len) {
5493 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5494 			" cancelled because not block aligned",
5495 			(unsigned long long)off, (unsigned long long)len);
5496 		return -EIO;
5497 	}
5498 
5499 	do {
5500 		bh = ext4_bread(handle, inode, blk,
5501 				EXT4_GET_BLOCKS_CREATE |
5502 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5503 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5504 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5505 	if (IS_ERR(bh))
5506 		return PTR_ERR(bh);
5507 	if (!bh)
5508 		goto out;
5509 	BUFFER_TRACE(bh, "get write access");
5510 	err = ext4_journal_get_write_access(handle, bh);
5511 	if (err) {
5512 		brelse(bh);
5513 		return err;
5514 	}
5515 	lock_buffer(bh);
5516 	memcpy(bh->b_data+offset, data, len);
5517 	flush_dcache_page(bh->b_page);
5518 	unlock_buffer(bh);
5519 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5520 	brelse(bh);
5521 out:
5522 	if (inode->i_size < off + len) {
5523 		i_size_write(inode, off + len);
5524 		EXT4_I(inode)->i_disksize = inode->i_size;
5525 		ext4_mark_inode_dirty(handle, inode);
5526 	}
5527 	return len;
5528 }
5529 
5530 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5531 {
5532 	const struct quota_format_ops	*ops;
5533 
5534 	if (!sb_has_quota_loaded(sb, qid->type))
5535 		return -ESRCH;
5536 	ops = sb_dqopt(sb)->ops[qid->type];
5537 	if (!ops || !ops->get_next_id)
5538 		return -ENOSYS;
5539 	return dquot_get_next_id(sb, qid);
5540 }
5541 #endif
5542 
5543 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5544 		       const char *dev_name, void *data)
5545 {
5546 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5547 }
5548 
5549 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5550 static inline void register_as_ext2(void)
5551 {
5552 	int err = register_filesystem(&ext2_fs_type);
5553 	if (err)
5554 		printk(KERN_WARNING
5555 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5556 }
5557 
5558 static inline void unregister_as_ext2(void)
5559 {
5560 	unregister_filesystem(&ext2_fs_type);
5561 }
5562 
5563 static inline int ext2_feature_set_ok(struct super_block *sb)
5564 {
5565 	if (ext4_has_unknown_ext2_incompat_features(sb))
5566 		return 0;
5567 	if (sb->s_flags & MS_RDONLY)
5568 		return 1;
5569 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5570 		return 0;
5571 	return 1;
5572 }
5573 #else
5574 static inline void register_as_ext2(void) { }
5575 static inline void unregister_as_ext2(void) { }
5576 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5577 #endif
5578 
5579 static inline void register_as_ext3(void)
5580 {
5581 	int err = register_filesystem(&ext3_fs_type);
5582 	if (err)
5583 		printk(KERN_WARNING
5584 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5585 }
5586 
5587 static inline void unregister_as_ext3(void)
5588 {
5589 	unregister_filesystem(&ext3_fs_type);
5590 }
5591 
5592 static inline int ext3_feature_set_ok(struct super_block *sb)
5593 {
5594 	if (ext4_has_unknown_ext3_incompat_features(sb))
5595 		return 0;
5596 	if (!ext4_has_feature_journal(sb))
5597 		return 0;
5598 	if (sb->s_flags & MS_RDONLY)
5599 		return 1;
5600 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5601 		return 0;
5602 	return 1;
5603 }
5604 
5605 static struct file_system_type ext4_fs_type = {
5606 	.owner		= THIS_MODULE,
5607 	.name		= "ext4",
5608 	.mount		= ext4_mount,
5609 	.kill_sb	= kill_block_super,
5610 	.fs_flags	= FS_REQUIRES_DEV,
5611 };
5612 MODULE_ALIAS_FS("ext4");
5613 
5614 /* Shared across all ext4 file systems */
5615 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5616 
5617 static int __init ext4_init_fs(void)
5618 {
5619 	int i, err;
5620 
5621 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5622 	ext4_li_info = NULL;
5623 	mutex_init(&ext4_li_mtx);
5624 
5625 	/* Build-time check for flags consistency */
5626 	ext4_check_flag_values();
5627 
5628 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5629 		init_waitqueue_head(&ext4__ioend_wq[i]);
5630 
5631 	err = ext4_init_es();
5632 	if (err)
5633 		return err;
5634 
5635 	err = ext4_init_pageio();
5636 	if (err)
5637 		goto out5;
5638 
5639 	err = ext4_init_system_zone();
5640 	if (err)
5641 		goto out4;
5642 
5643 	err = ext4_init_sysfs();
5644 	if (err)
5645 		goto out3;
5646 
5647 	err = ext4_init_mballoc();
5648 	if (err)
5649 		goto out2;
5650 	err = init_inodecache();
5651 	if (err)
5652 		goto out1;
5653 	register_as_ext3();
5654 	register_as_ext2();
5655 	err = register_filesystem(&ext4_fs_type);
5656 	if (err)
5657 		goto out;
5658 
5659 	return 0;
5660 out:
5661 	unregister_as_ext2();
5662 	unregister_as_ext3();
5663 	destroy_inodecache();
5664 out1:
5665 	ext4_exit_mballoc();
5666 out2:
5667 	ext4_exit_sysfs();
5668 out3:
5669 	ext4_exit_system_zone();
5670 out4:
5671 	ext4_exit_pageio();
5672 out5:
5673 	ext4_exit_es();
5674 
5675 	return err;
5676 }
5677 
5678 static void __exit ext4_exit_fs(void)
5679 {
5680 	ext4_destroy_lazyinit_thread();
5681 	unregister_as_ext2();
5682 	unregister_as_ext3();
5683 	unregister_filesystem(&ext4_fs_type);
5684 	destroy_inodecache();
5685 	ext4_exit_mballoc();
5686 	ext4_exit_sysfs();
5687 	ext4_exit_system_zone();
5688 	ext4_exit_pageio();
5689 	ext4_exit_es();
5690 }
5691 
5692 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5693 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5694 MODULE_LICENSE("GPL");
5695 module_init(ext4_init_fs)
5696 module_exit(ext4_exit_fs)
5697