xref: /openbmc/linux/fs/ext4/super.c (revision 232b0b08)
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 (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
442 		return;
443 
444 	if (ext4_error_ratelimit(sb)) {
445 		va_start(args, fmt);
446 		vaf.fmt = fmt;
447 		vaf.va = &args;
448 		printk(KERN_CRIT
449 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
450 		       sb->s_id, function, line, current->comm, &vaf);
451 		va_end(args);
452 	}
453 	save_error_info(sb, function, line);
454 	ext4_handle_error(sb);
455 }
456 
457 void __ext4_error_inode(struct inode *inode, const char *function,
458 			unsigned int line, ext4_fsblk_t block,
459 			const char *fmt, ...)
460 {
461 	va_list args;
462 	struct va_format vaf;
463 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
464 
465 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
466 		return;
467 
468 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
469 	es->s_last_error_block = cpu_to_le64(block);
470 	if (ext4_error_ratelimit(inode->i_sb)) {
471 		va_start(args, fmt);
472 		vaf.fmt = fmt;
473 		vaf.va = &args;
474 		if (block)
475 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
476 			       "inode #%lu: block %llu: comm %s: %pV\n",
477 			       inode->i_sb->s_id, function, line, inode->i_ino,
478 			       block, current->comm, &vaf);
479 		else
480 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
481 			       "inode #%lu: comm %s: %pV\n",
482 			       inode->i_sb->s_id, function, line, inode->i_ino,
483 			       current->comm, &vaf);
484 		va_end(args);
485 	}
486 	save_error_info(inode->i_sb, function, line);
487 	ext4_handle_error(inode->i_sb);
488 }
489 
490 void __ext4_error_file(struct file *file, const char *function,
491 		       unsigned int line, ext4_fsblk_t block,
492 		       const char *fmt, ...)
493 {
494 	va_list args;
495 	struct va_format vaf;
496 	struct ext4_super_block *es;
497 	struct inode *inode = file_inode(file);
498 	char pathname[80], *path;
499 
500 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
501 		return;
502 
503 	es = EXT4_SB(inode->i_sb)->s_es;
504 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
505 	if (ext4_error_ratelimit(inode->i_sb)) {
506 		path = file_path(file, pathname, sizeof(pathname));
507 		if (IS_ERR(path))
508 			path = "(unknown)";
509 		va_start(args, fmt);
510 		vaf.fmt = fmt;
511 		vaf.va = &args;
512 		if (block)
513 			printk(KERN_CRIT
514 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
515 			       "block %llu: comm %s: path %s: %pV\n",
516 			       inode->i_sb->s_id, function, line, inode->i_ino,
517 			       block, current->comm, path, &vaf);
518 		else
519 			printk(KERN_CRIT
520 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
521 			       "comm %s: path %s: %pV\n",
522 			       inode->i_sb->s_id, function, line, inode->i_ino,
523 			       current->comm, path, &vaf);
524 		va_end(args);
525 	}
526 	save_error_info(inode->i_sb, function, line);
527 	ext4_handle_error(inode->i_sb);
528 }
529 
530 const char *ext4_decode_error(struct super_block *sb, int errno,
531 			      char nbuf[16])
532 {
533 	char *errstr = NULL;
534 
535 	switch (errno) {
536 	case -EFSCORRUPTED:
537 		errstr = "Corrupt filesystem";
538 		break;
539 	case -EFSBADCRC:
540 		errstr = "Filesystem failed CRC";
541 		break;
542 	case -EIO:
543 		errstr = "IO failure";
544 		break;
545 	case -ENOMEM:
546 		errstr = "Out of memory";
547 		break;
548 	case -EROFS:
549 		if (!sb || (EXT4_SB(sb)->s_journal &&
550 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
551 			errstr = "Journal has aborted";
552 		else
553 			errstr = "Readonly filesystem";
554 		break;
555 	default:
556 		/* If the caller passed in an extra buffer for unknown
557 		 * errors, textualise them now.  Else we just return
558 		 * NULL. */
559 		if (nbuf) {
560 			/* Check for truncated error codes... */
561 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
562 				errstr = nbuf;
563 		}
564 		break;
565 	}
566 
567 	return errstr;
568 }
569 
570 /* __ext4_std_error decodes expected errors from journaling functions
571  * automatically and invokes the appropriate error response.  */
572 
573 void __ext4_std_error(struct super_block *sb, const char *function,
574 		      unsigned int line, int errno)
575 {
576 	char nbuf[16];
577 	const char *errstr;
578 
579 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
580 		return;
581 
582 	/* Special case: if the error is EROFS, and we're not already
583 	 * inside a transaction, then there's really no point in logging
584 	 * an error. */
585 	if (errno == -EROFS && journal_current_handle() == NULL &&
586 	    (sb->s_flags & MS_RDONLY))
587 		return;
588 
589 	if (ext4_error_ratelimit(sb)) {
590 		errstr = ext4_decode_error(sb, errno, nbuf);
591 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
592 		       sb->s_id, function, line, errstr);
593 	}
594 
595 	save_error_info(sb, function, line);
596 	ext4_handle_error(sb);
597 }
598 
599 /*
600  * ext4_abort is a much stronger failure handler than ext4_error.  The
601  * abort function may be used to deal with unrecoverable failures such
602  * as journal IO errors or ENOMEM at a critical moment in log management.
603  *
604  * We unconditionally force the filesystem into an ABORT|READONLY state,
605  * unless the error response on the fs has been set to panic in which
606  * case we take the easy way out and panic immediately.
607  */
608 
609 void __ext4_abort(struct super_block *sb, const char *function,
610 		unsigned int line, const char *fmt, ...)
611 {
612 	struct va_format vaf;
613 	va_list args;
614 
615 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
616 		return;
617 
618 	save_error_info(sb, function, line);
619 	va_start(args, fmt);
620 	vaf.fmt = fmt;
621 	vaf.va = &args;
622 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
623 	       sb->s_id, function, line, &vaf);
624 	va_end(args);
625 
626 	if ((sb->s_flags & MS_RDONLY) == 0) {
627 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
628 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
629 		/*
630 		 * Make sure updated value of ->s_mount_flags will be visible
631 		 * before ->s_flags update
632 		 */
633 		smp_wmb();
634 		sb->s_flags |= MS_RDONLY;
635 		if (EXT4_SB(sb)->s_journal)
636 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
637 		save_error_info(sb, function, line);
638 	}
639 	if (test_opt(sb, ERRORS_PANIC)) {
640 		if (EXT4_SB(sb)->s_journal &&
641 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
642 			return;
643 		panic("EXT4-fs panic from previous error\n");
644 	}
645 }
646 
647 void __ext4_msg(struct super_block *sb,
648 		const char *prefix, const char *fmt, ...)
649 {
650 	struct va_format vaf;
651 	va_list args;
652 
653 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
654 		return;
655 
656 	va_start(args, fmt);
657 	vaf.fmt = fmt;
658 	vaf.va = &args;
659 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
660 	va_end(args);
661 }
662 
663 #define ext4_warning_ratelimit(sb)					\
664 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
665 			     "EXT4-fs warning")
666 
667 void __ext4_warning(struct super_block *sb, const char *function,
668 		    unsigned int line, const char *fmt, ...)
669 {
670 	struct va_format vaf;
671 	va_list args;
672 
673 	if (!ext4_warning_ratelimit(sb))
674 		return;
675 
676 	va_start(args, fmt);
677 	vaf.fmt = fmt;
678 	vaf.va = &args;
679 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
680 	       sb->s_id, function, line, &vaf);
681 	va_end(args);
682 }
683 
684 void __ext4_warning_inode(const struct inode *inode, const char *function,
685 			  unsigned int line, const char *fmt, ...)
686 {
687 	struct va_format vaf;
688 	va_list args;
689 
690 	if (!ext4_warning_ratelimit(inode->i_sb))
691 		return;
692 
693 	va_start(args, fmt);
694 	vaf.fmt = fmt;
695 	vaf.va = &args;
696 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
697 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
698 	       function, line, inode->i_ino, current->comm, &vaf);
699 	va_end(args);
700 }
701 
702 void __ext4_grp_locked_error(const char *function, unsigned int line,
703 			     struct super_block *sb, ext4_group_t grp,
704 			     unsigned long ino, ext4_fsblk_t block,
705 			     const char *fmt, ...)
706 __releases(bitlock)
707 __acquires(bitlock)
708 {
709 	struct va_format vaf;
710 	va_list args;
711 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
712 
713 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
714 		return;
715 
716 	es->s_last_error_ino = cpu_to_le32(ino);
717 	es->s_last_error_block = cpu_to_le64(block);
718 	__save_error_info(sb, function, line);
719 
720 	if (ext4_error_ratelimit(sb)) {
721 		va_start(args, fmt);
722 		vaf.fmt = fmt;
723 		vaf.va = &args;
724 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
725 		       sb->s_id, function, line, grp);
726 		if (ino)
727 			printk(KERN_CONT "inode %lu: ", ino);
728 		if (block)
729 			printk(KERN_CONT "block %llu:",
730 			       (unsigned long long) block);
731 		printk(KERN_CONT "%pV\n", &vaf);
732 		va_end(args);
733 	}
734 
735 	if (test_opt(sb, ERRORS_CONT)) {
736 		ext4_commit_super(sb, 0);
737 		return;
738 	}
739 
740 	ext4_unlock_group(sb, grp);
741 	ext4_handle_error(sb);
742 	/*
743 	 * We only get here in the ERRORS_RO case; relocking the group
744 	 * may be dangerous, but nothing bad will happen since the
745 	 * filesystem will have already been marked read/only and the
746 	 * journal has been aborted.  We return 1 as a hint to callers
747 	 * who might what to use the return value from
748 	 * ext4_grp_locked_error() to distinguish between the
749 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
750 	 * aggressively from the ext4 function in question, with a
751 	 * more appropriate error code.
752 	 */
753 	ext4_lock_group(sb, grp);
754 	return;
755 }
756 
757 void ext4_update_dynamic_rev(struct super_block *sb)
758 {
759 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
760 
761 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
762 		return;
763 
764 	ext4_warning(sb,
765 		     "updating to rev %d because of new feature flag, "
766 		     "running e2fsck is recommended",
767 		     EXT4_DYNAMIC_REV);
768 
769 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
770 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
771 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
772 	/* leave es->s_feature_*compat flags alone */
773 	/* es->s_uuid will be set by e2fsck if empty */
774 
775 	/*
776 	 * The rest of the superblock fields should be zero, and if not it
777 	 * means they are likely already in use, so leave them alone.  We
778 	 * can leave it up to e2fsck to clean up any inconsistencies there.
779 	 */
780 }
781 
782 /*
783  * Open the external journal device
784  */
785 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
786 {
787 	struct block_device *bdev;
788 	char b[BDEVNAME_SIZE];
789 
790 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
791 	if (IS_ERR(bdev))
792 		goto fail;
793 	return bdev;
794 
795 fail:
796 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
797 			__bdevname(dev, b), PTR_ERR(bdev));
798 	return NULL;
799 }
800 
801 /*
802  * Release the journal device
803  */
804 static void ext4_blkdev_put(struct block_device *bdev)
805 {
806 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
807 }
808 
809 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
810 {
811 	struct block_device *bdev;
812 	bdev = sbi->journal_bdev;
813 	if (bdev) {
814 		ext4_blkdev_put(bdev);
815 		sbi->journal_bdev = NULL;
816 	}
817 }
818 
819 static inline struct inode *orphan_list_entry(struct list_head *l)
820 {
821 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
822 }
823 
824 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
825 {
826 	struct list_head *l;
827 
828 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
829 		 le32_to_cpu(sbi->s_es->s_last_orphan));
830 
831 	printk(KERN_ERR "sb_info orphan list:\n");
832 	list_for_each(l, &sbi->s_orphan) {
833 		struct inode *inode = orphan_list_entry(l);
834 		printk(KERN_ERR "  "
835 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
836 		       inode->i_sb->s_id, inode->i_ino, inode,
837 		       inode->i_mode, inode->i_nlink,
838 		       NEXT_ORPHAN(inode));
839 	}
840 }
841 
842 static void ext4_put_super(struct super_block *sb)
843 {
844 	struct ext4_sb_info *sbi = EXT4_SB(sb);
845 	struct ext4_super_block *es = sbi->s_es;
846 	int aborted = 0;
847 	int i, err;
848 
849 	ext4_unregister_li_request(sb);
850 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
851 
852 	flush_workqueue(sbi->rsv_conversion_wq);
853 	destroy_workqueue(sbi->rsv_conversion_wq);
854 
855 	if (sbi->s_journal) {
856 		aborted = is_journal_aborted(sbi->s_journal);
857 		err = jbd2_journal_destroy(sbi->s_journal);
858 		sbi->s_journal = NULL;
859 		if ((err < 0) && !aborted)
860 			ext4_abort(sb, "Couldn't clean up the journal");
861 	}
862 
863 	ext4_unregister_sysfs(sb);
864 	ext4_es_unregister_shrinker(sbi);
865 	del_timer_sync(&sbi->s_err_report);
866 	ext4_release_system_zone(sb);
867 	ext4_mb_release(sb);
868 	ext4_ext_release(sb);
869 
870 	if (!(sb->s_flags & MS_RDONLY) && !aborted) {
871 		ext4_clear_feature_journal_needs_recovery(sb);
872 		es->s_state = cpu_to_le16(sbi->s_mount_state);
873 	}
874 	if (!(sb->s_flags & MS_RDONLY))
875 		ext4_commit_super(sb, 1);
876 
877 	for (i = 0; i < sbi->s_gdb_count; i++)
878 		brelse(sbi->s_group_desc[i]);
879 	kvfree(sbi->s_group_desc);
880 	kvfree(sbi->s_flex_groups);
881 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
882 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
883 	percpu_counter_destroy(&sbi->s_dirs_counter);
884 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
885 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
886 #ifdef CONFIG_QUOTA
887 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
888 		kfree(sbi->s_qf_names[i]);
889 #endif
890 
891 	/* Debugging code just in case the in-memory inode orphan list
892 	 * isn't empty.  The on-disk one can be non-empty if we've
893 	 * detected an error and taken the fs readonly, but the
894 	 * in-memory list had better be clean by this point. */
895 	if (!list_empty(&sbi->s_orphan))
896 		dump_orphan_list(sb, sbi);
897 	J_ASSERT(list_empty(&sbi->s_orphan));
898 
899 	sync_blockdev(sb->s_bdev);
900 	invalidate_bdev(sb->s_bdev);
901 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
902 		/*
903 		 * Invalidate the journal device's buffers.  We don't want them
904 		 * floating about in memory - the physical journal device may
905 		 * hotswapped, and it breaks the `ro-after' testing code.
906 		 */
907 		sync_blockdev(sbi->journal_bdev);
908 		invalidate_bdev(sbi->journal_bdev);
909 		ext4_blkdev_remove(sbi);
910 	}
911 	if (sbi->s_mb_cache) {
912 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
913 		sbi->s_mb_cache = NULL;
914 	}
915 	if (sbi->s_mmp_tsk)
916 		kthread_stop(sbi->s_mmp_tsk);
917 	brelse(sbi->s_sbh);
918 	sb->s_fs_info = NULL;
919 	/*
920 	 * Now that we are completely done shutting down the
921 	 * superblock, we need to actually destroy the kobject.
922 	 */
923 	kobject_put(&sbi->s_kobj);
924 	wait_for_completion(&sbi->s_kobj_unregister);
925 	if (sbi->s_chksum_driver)
926 		crypto_free_shash(sbi->s_chksum_driver);
927 	kfree(sbi->s_blockgroup_lock);
928 	kfree(sbi);
929 }
930 
931 static struct kmem_cache *ext4_inode_cachep;
932 
933 /*
934  * Called inside transaction, so use GFP_NOFS
935  */
936 static struct inode *ext4_alloc_inode(struct super_block *sb)
937 {
938 	struct ext4_inode_info *ei;
939 
940 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
941 	if (!ei)
942 		return NULL;
943 
944 	ei->vfs_inode.i_version = 1;
945 	spin_lock_init(&ei->i_raw_lock);
946 	INIT_LIST_HEAD(&ei->i_prealloc_list);
947 	spin_lock_init(&ei->i_prealloc_lock);
948 	ext4_es_init_tree(&ei->i_es_tree);
949 	rwlock_init(&ei->i_es_lock);
950 	INIT_LIST_HEAD(&ei->i_es_list);
951 	ei->i_es_all_nr = 0;
952 	ei->i_es_shk_nr = 0;
953 	ei->i_es_shrink_lblk = 0;
954 	ei->i_reserved_data_blocks = 0;
955 	ei->i_reserved_meta_blocks = 0;
956 	ei->i_allocated_meta_blocks = 0;
957 	ei->i_da_metadata_calc_len = 0;
958 	ei->i_da_metadata_calc_last_lblock = 0;
959 	spin_lock_init(&(ei->i_block_reservation_lock));
960 #ifdef CONFIG_QUOTA
961 	ei->i_reserved_quota = 0;
962 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
963 #endif
964 	ei->jinode = NULL;
965 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
966 	spin_lock_init(&ei->i_completed_io_lock);
967 	ei->i_sync_tid = 0;
968 	ei->i_datasync_tid = 0;
969 	atomic_set(&ei->i_unwritten, 0);
970 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
971 	return &ei->vfs_inode;
972 }
973 
974 static int ext4_drop_inode(struct inode *inode)
975 {
976 	int drop = generic_drop_inode(inode);
977 
978 	trace_ext4_drop_inode(inode, drop);
979 	return drop;
980 }
981 
982 static void ext4_i_callback(struct rcu_head *head)
983 {
984 	struct inode *inode = container_of(head, struct inode, i_rcu);
985 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
986 }
987 
988 static void ext4_destroy_inode(struct inode *inode)
989 {
990 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
991 		ext4_msg(inode->i_sb, KERN_ERR,
992 			 "Inode %lu (%p): orphan list check failed!",
993 			 inode->i_ino, EXT4_I(inode));
994 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
995 				EXT4_I(inode), sizeof(struct ext4_inode_info),
996 				true);
997 		dump_stack();
998 	}
999 	call_rcu(&inode->i_rcu, ext4_i_callback);
1000 }
1001 
1002 static void init_once(void *foo)
1003 {
1004 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1005 
1006 	INIT_LIST_HEAD(&ei->i_orphan);
1007 	init_rwsem(&ei->xattr_sem);
1008 	init_rwsem(&ei->i_data_sem);
1009 	init_rwsem(&ei->i_mmap_sem);
1010 	inode_init_once(&ei->vfs_inode);
1011 }
1012 
1013 static int __init init_inodecache(void)
1014 {
1015 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1016 					     sizeof(struct ext4_inode_info),
1017 					     0, (SLAB_RECLAIM_ACCOUNT|
1018 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1019 					     init_once);
1020 	if (ext4_inode_cachep == NULL)
1021 		return -ENOMEM;
1022 	return 0;
1023 }
1024 
1025 static void destroy_inodecache(void)
1026 {
1027 	/*
1028 	 * Make sure all delayed rcu free inodes are flushed before we
1029 	 * destroy cache.
1030 	 */
1031 	rcu_barrier();
1032 	kmem_cache_destroy(ext4_inode_cachep);
1033 }
1034 
1035 void ext4_clear_inode(struct inode *inode)
1036 {
1037 	invalidate_inode_buffers(inode);
1038 	clear_inode(inode);
1039 	dquot_drop(inode);
1040 	ext4_discard_preallocations(inode);
1041 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1042 	if (EXT4_I(inode)->jinode) {
1043 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1044 					       EXT4_I(inode)->jinode);
1045 		jbd2_free_inode(EXT4_I(inode)->jinode);
1046 		EXT4_I(inode)->jinode = NULL;
1047 	}
1048 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1049 	fscrypt_put_encryption_info(inode, NULL);
1050 #endif
1051 }
1052 
1053 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1054 					u64 ino, u32 generation)
1055 {
1056 	struct inode *inode;
1057 
1058 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1059 		return ERR_PTR(-ESTALE);
1060 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1061 		return ERR_PTR(-ESTALE);
1062 
1063 	/* iget isn't really right if the inode is currently unallocated!!
1064 	 *
1065 	 * ext4_read_inode will return a bad_inode if the inode had been
1066 	 * deleted, so we should be safe.
1067 	 *
1068 	 * Currently we don't know the generation for parent directory, so
1069 	 * a generation of 0 means "accept any"
1070 	 */
1071 	inode = ext4_iget_normal(sb, ino);
1072 	if (IS_ERR(inode))
1073 		return ERR_CAST(inode);
1074 	if (generation && inode->i_generation != generation) {
1075 		iput(inode);
1076 		return ERR_PTR(-ESTALE);
1077 	}
1078 
1079 	return inode;
1080 }
1081 
1082 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1083 					int fh_len, int fh_type)
1084 {
1085 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1086 				    ext4_nfs_get_inode);
1087 }
1088 
1089 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1090 					int fh_len, int fh_type)
1091 {
1092 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1093 				    ext4_nfs_get_inode);
1094 }
1095 
1096 /*
1097  * Try to release metadata pages (indirect blocks, directories) which are
1098  * mapped via the block device.  Since these pages could have journal heads
1099  * which would prevent try_to_free_buffers() from freeing them, we must use
1100  * jbd2 layer's try_to_free_buffers() function to release them.
1101  */
1102 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1103 				 gfp_t wait)
1104 {
1105 	journal_t *journal = EXT4_SB(sb)->s_journal;
1106 
1107 	WARN_ON(PageChecked(page));
1108 	if (!page_has_buffers(page))
1109 		return 0;
1110 	if (journal)
1111 		return jbd2_journal_try_to_free_buffers(journal, page,
1112 						wait & ~__GFP_DIRECT_RECLAIM);
1113 	return try_to_free_buffers(page);
1114 }
1115 
1116 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1117 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1118 {
1119 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1120 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1121 }
1122 
1123 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1124 							void *fs_data)
1125 {
1126 	handle_t *handle = fs_data;
1127 	int res, res2, retries = 0;
1128 
1129 	res = ext4_convert_inline_data(inode);
1130 	if (res)
1131 		return res;
1132 
1133 	/*
1134 	 * If a journal handle was specified, then the encryption context is
1135 	 * being set on a new inode via inheritance and is part of a larger
1136 	 * transaction to create the inode.  Otherwise the encryption context is
1137 	 * being set on an existing inode in its own transaction.  Only in the
1138 	 * latter case should the "retry on ENOSPC" logic be used.
1139 	 */
1140 
1141 	if (handle) {
1142 		res = ext4_xattr_set_handle(handle, inode,
1143 					    EXT4_XATTR_INDEX_ENCRYPTION,
1144 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1145 					    ctx, len, 0);
1146 		if (!res) {
1147 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1148 			ext4_clear_inode_state(inode,
1149 					EXT4_STATE_MAY_INLINE_DATA);
1150 			/*
1151 			 * Update inode->i_flags - e.g. S_DAX may get disabled
1152 			 */
1153 			ext4_set_inode_flags(inode);
1154 		}
1155 		return res;
1156 	}
1157 
1158 retry:
1159 	handle = ext4_journal_start(inode, EXT4_HT_MISC,
1160 			ext4_jbd2_credits_xattr(inode));
1161 	if (IS_ERR(handle))
1162 		return PTR_ERR(handle);
1163 
1164 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1165 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1166 				    ctx, len, 0);
1167 	if (!res) {
1168 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1169 		/* Update inode->i_flags - e.g. S_DAX may get disabled */
1170 		ext4_set_inode_flags(inode);
1171 		res = ext4_mark_inode_dirty(handle, inode);
1172 		if (res)
1173 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1174 	}
1175 	res2 = ext4_journal_stop(handle);
1176 
1177 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1178 		goto retry;
1179 	if (!res)
1180 		res = res2;
1181 	return res;
1182 }
1183 
1184 static int ext4_dummy_context(struct inode *inode)
1185 {
1186 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1187 }
1188 
1189 static unsigned ext4_max_namelen(struct inode *inode)
1190 {
1191 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1192 		EXT4_NAME_LEN;
1193 }
1194 
1195 static const struct fscrypt_operations ext4_cryptops = {
1196 	.key_prefix		= "ext4:",
1197 	.get_context		= ext4_get_context,
1198 	.set_context		= ext4_set_context,
1199 	.dummy_context		= ext4_dummy_context,
1200 	.is_encrypted		= ext4_encrypted_inode,
1201 	.empty_dir		= ext4_empty_dir,
1202 	.max_namelen		= ext4_max_namelen,
1203 };
1204 #else
1205 static const struct fscrypt_operations ext4_cryptops = {
1206 	.is_encrypted		= ext4_encrypted_inode,
1207 };
1208 #endif
1209 
1210 #ifdef CONFIG_QUOTA
1211 static char *quotatypes[] = INITQFNAMES;
1212 #define QTYPE2NAME(t) (quotatypes[t])
1213 
1214 static int ext4_write_dquot(struct dquot *dquot);
1215 static int ext4_acquire_dquot(struct dquot *dquot);
1216 static int ext4_release_dquot(struct dquot *dquot);
1217 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1218 static int ext4_write_info(struct super_block *sb, int type);
1219 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1220 			 const struct path *path);
1221 static int ext4_quota_off(struct super_block *sb, int type);
1222 static int ext4_quota_on_mount(struct super_block *sb, int type);
1223 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1224 			       size_t len, loff_t off);
1225 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1226 				const char *data, size_t len, loff_t off);
1227 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1228 			     unsigned int flags);
1229 static int ext4_enable_quotas(struct super_block *sb);
1230 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1231 
1232 static struct dquot **ext4_get_dquots(struct inode *inode)
1233 {
1234 	return EXT4_I(inode)->i_dquot;
1235 }
1236 
1237 static const struct dquot_operations ext4_quota_operations = {
1238 	.get_reserved_space = ext4_get_reserved_space,
1239 	.write_dquot	= ext4_write_dquot,
1240 	.acquire_dquot	= ext4_acquire_dquot,
1241 	.release_dquot	= ext4_release_dquot,
1242 	.mark_dirty	= ext4_mark_dquot_dirty,
1243 	.write_info	= ext4_write_info,
1244 	.alloc_dquot	= dquot_alloc,
1245 	.destroy_dquot	= dquot_destroy,
1246 	.get_projid	= ext4_get_projid,
1247 	.get_next_id	= ext4_get_next_id,
1248 };
1249 
1250 static const struct quotactl_ops ext4_qctl_operations = {
1251 	.quota_on	= ext4_quota_on,
1252 	.quota_off	= ext4_quota_off,
1253 	.quota_sync	= dquot_quota_sync,
1254 	.get_state	= dquot_get_state,
1255 	.set_info	= dquot_set_dqinfo,
1256 	.get_dqblk	= dquot_get_dqblk,
1257 	.set_dqblk	= dquot_set_dqblk,
1258 	.get_nextdqblk	= dquot_get_next_dqblk,
1259 };
1260 #endif
1261 
1262 static const struct super_operations ext4_sops = {
1263 	.alloc_inode	= ext4_alloc_inode,
1264 	.destroy_inode	= ext4_destroy_inode,
1265 	.write_inode	= ext4_write_inode,
1266 	.dirty_inode	= ext4_dirty_inode,
1267 	.drop_inode	= ext4_drop_inode,
1268 	.evict_inode	= ext4_evict_inode,
1269 	.put_super	= ext4_put_super,
1270 	.sync_fs	= ext4_sync_fs,
1271 	.freeze_fs	= ext4_freeze,
1272 	.unfreeze_fs	= ext4_unfreeze,
1273 	.statfs		= ext4_statfs,
1274 	.remount_fs	= ext4_remount,
1275 	.show_options	= ext4_show_options,
1276 #ifdef CONFIG_QUOTA
1277 	.quota_read	= ext4_quota_read,
1278 	.quota_write	= ext4_quota_write,
1279 	.get_dquots	= ext4_get_dquots,
1280 #endif
1281 	.bdev_try_to_free_page = bdev_try_to_free_page,
1282 };
1283 
1284 static const struct export_operations ext4_export_ops = {
1285 	.fh_to_dentry = ext4_fh_to_dentry,
1286 	.fh_to_parent = ext4_fh_to_parent,
1287 	.get_parent = ext4_get_parent,
1288 };
1289 
1290 enum {
1291 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1292 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1293 	Opt_nouid32, Opt_debug, Opt_removed,
1294 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1295 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1296 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1297 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1298 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1299 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1300 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1301 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1302 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1303 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1304 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1305 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1306 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1307 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1308 	Opt_dioread_nolock, Opt_dioread_lock,
1309 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1310 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1311 };
1312 
1313 static const match_table_t tokens = {
1314 	{Opt_bsd_df, "bsddf"},
1315 	{Opt_minix_df, "minixdf"},
1316 	{Opt_grpid, "grpid"},
1317 	{Opt_grpid, "bsdgroups"},
1318 	{Opt_nogrpid, "nogrpid"},
1319 	{Opt_nogrpid, "sysvgroups"},
1320 	{Opt_resgid, "resgid=%u"},
1321 	{Opt_resuid, "resuid=%u"},
1322 	{Opt_sb, "sb=%u"},
1323 	{Opt_err_cont, "errors=continue"},
1324 	{Opt_err_panic, "errors=panic"},
1325 	{Opt_err_ro, "errors=remount-ro"},
1326 	{Opt_nouid32, "nouid32"},
1327 	{Opt_debug, "debug"},
1328 	{Opt_removed, "oldalloc"},
1329 	{Opt_removed, "orlov"},
1330 	{Opt_user_xattr, "user_xattr"},
1331 	{Opt_nouser_xattr, "nouser_xattr"},
1332 	{Opt_acl, "acl"},
1333 	{Opt_noacl, "noacl"},
1334 	{Opt_noload, "norecovery"},
1335 	{Opt_noload, "noload"},
1336 	{Opt_removed, "nobh"},
1337 	{Opt_removed, "bh"},
1338 	{Opt_commit, "commit=%u"},
1339 	{Opt_min_batch_time, "min_batch_time=%u"},
1340 	{Opt_max_batch_time, "max_batch_time=%u"},
1341 	{Opt_journal_dev, "journal_dev=%u"},
1342 	{Opt_journal_path, "journal_path=%s"},
1343 	{Opt_journal_checksum, "journal_checksum"},
1344 	{Opt_nojournal_checksum, "nojournal_checksum"},
1345 	{Opt_journal_async_commit, "journal_async_commit"},
1346 	{Opt_abort, "abort"},
1347 	{Opt_data_journal, "data=journal"},
1348 	{Opt_data_ordered, "data=ordered"},
1349 	{Opt_data_writeback, "data=writeback"},
1350 	{Opt_data_err_abort, "data_err=abort"},
1351 	{Opt_data_err_ignore, "data_err=ignore"},
1352 	{Opt_offusrjquota, "usrjquota="},
1353 	{Opt_usrjquota, "usrjquota=%s"},
1354 	{Opt_offgrpjquota, "grpjquota="},
1355 	{Opt_grpjquota, "grpjquota=%s"},
1356 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1357 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1358 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1359 	{Opt_grpquota, "grpquota"},
1360 	{Opt_noquota, "noquota"},
1361 	{Opt_quota, "quota"},
1362 	{Opt_usrquota, "usrquota"},
1363 	{Opt_prjquota, "prjquota"},
1364 	{Opt_barrier, "barrier=%u"},
1365 	{Opt_barrier, "barrier"},
1366 	{Opt_nobarrier, "nobarrier"},
1367 	{Opt_i_version, "i_version"},
1368 	{Opt_dax, "dax"},
1369 	{Opt_stripe, "stripe=%u"},
1370 	{Opt_delalloc, "delalloc"},
1371 	{Opt_lazytime, "lazytime"},
1372 	{Opt_nolazytime, "nolazytime"},
1373 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1374 	{Opt_nodelalloc, "nodelalloc"},
1375 	{Opt_removed, "mblk_io_submit"},
1376 	{Opt_removed, "nomblk_io_submit"},
1377 	{Opt_block_validity, "block_validity"},
1378 	{Opt_noblock_validity, "noblock_validity"},
1379 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1380 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1381 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1382 	{Opt_auto_da_alloc, "auto_da_alloc"},
1383 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1384 	{Opt_dioread_nolock, "dioread_nolock"},
1385 	{Opt_dioread_lock, "dioread_lock"},
1386 	{Opt_discard, "discard"},
1387 	{Opt_nodiscard, "nodiscard"},
1388 	{Opt_init_itable, "init_itable=%u"},
1389 	{Opt_init_itable, "init_itable"},
1390 	{Opt_noinit_itable, "noinit_itable"},
1391 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1392 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1393 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1394 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1395 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1396 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1397 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1398 	{Opt_err, NULL},
1399 };
1400 
1401 static ext4_fsblk_t get_sb_block(void **data)
1402 {
1403 	ext4_fsblk_t	sb_block;
1404 	char		*options = (char *) *data;
1405 
1406 	if (!options || strncmp(options, "sb=", 3) != 0)
1407 		return 1;	/* Default location */
1408 
1409 	options += 3;
1410 	/* TODO: use simple_strtoll with >32bit ext4 */
1411 	sb_block = simple_strtoul(options, &options, 0);
1412 	if (*options && *options != ',') {
1413 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1414 		       (char *) *data);
1415 		return 1;
1416 	}
1417 	if (*options == ',')
1418 		options++;
1419 	*data = (void *) options;
1420 
1421 	return sb_block;
1422 }
1423 
1424 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1425 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1426 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1427 
1428 #ifdef CONFIG_QUOTA
1429 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1430 {
1431 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1432 	char *qname;
1433 	int ret = -1;
1434 
1435 	if (sb_any_quota_loaded(sb) &&
1436 		!sbi->s_qf_names[qtype]) {
1437 		ext4_msg(sb, KERN_ERR,
1438 			"Cannot change journaled "
1439 			"quota options when quota turned on");
1440 		return -1;
1441 	}
1442 	if (ext4_has_feature_quota(sb)) {
1443 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1444 			 "ignored when QUOTA feature is enabled");
1445 		return 1;
1446 	}
1447 	qname = match_strdup(args);
1448 	if (!qname) {
1449 		ext4_msg(sb, KERN_ERR,
1450 			"Not enough memory for storing quotafile name");
1451 		return -1;
1452 	}
1453 	if (sbi->s_qf_names[qtype]) {
1454 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1455 			ret = 1;
1456 		else
1457 			ext4_msg(sb, KERN_ERR,
1458 				 "%s quota file already specified",
1459 				 QTYPE2NAME(qtype));
1460 		goto errout;
1461 	}
1462 	if (strchr(qname, '/')) {
1463 		ext4_msg(sb, KERN_ERR,
1464 			"quotafile must be on filesystem root");
1465 		goto errout;
1466 	}
1467 	sbi->s_qf_names[qtype] = qname;
1468 	set_opt(sb, QUOTA);
1469 	return 1;
1470 errout:
1471 	kfree(qname);
1472 	return ret;
1473 }
1474 
1475 static int clear_qf_name(struct super_block *sb, int qtype)
1476 {
1477 
1478 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1479 
1480 	if (sb_any_quota_loaded(sb) &&
1481 		sbi->s_qf_names[qtype]) {
1482 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1483 			" when quota turned on");
1484 		return -1;
1485 	}
1486 	kfree(sbi->s_qf_names[qtype]);
1487 	sbi->s_qf_names[qtype] = NULL;
1488 	return 1;
1489 }
1490 #endif
1491 
1492 #define MOPT_SET	0x0001
1493 #define MOPT_CLEAR	0x0002
1494 #define MOPT_NOSUPPORT	0x0004
1495 #define MOPT_EXPLICIT	0x0008
1496 #define MOPT_CLEAR_ERR	0x0010
1497 #define MOPT_GTE0	0x0020
1498 #ifdef CONFIG_QUOTA
1499 #define MOPT_Q		0
1500 #define MOPT_QFMT	0x0040
1501 #else
1502 #define MOPT_Q		MOPT_NOSUPPORT
1503 #define MOPT_QFMT	MOPT_NOSUPPORT
1504 #endif
1505 #define MOPT_DATAJ	0x0080
1506 #define MOPT_NO_EXT2	0x0100
1507 #define MOPT_NO_EXT3	0x0200
1508 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1509 #define MOPT_STRING	0x0400
1510 
1511 static const struct mount_opts {
1512 	int	token;
1513 	int	mount_opt;
1514 	int	flags;
1515 } ext4_mount_opts[] = {
1516 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1517 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1518 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1519 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1520 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1521 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1522 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1523 	 MOPT_EXT4_ONLY | MOPT_SET},
1524 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1525 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1526 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1527 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1528 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1529 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1530 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1531 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1532 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1533 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1534 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1535 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1536 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1537 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1538 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1539 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1540 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1541 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1542 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1543 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1544 	 MOPT_NO_EXT2},
1545 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1546 	 MOPT_NO_EXT2},
1547 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1548 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1549 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1550 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1551 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1552 	{Opt_commit, 0, MOPT_GTE0},
1553 	{Opt_max_batch_time, 0, MOPT_GTE0},
1554 	{Opt_min_batch_time, 0, MOPT_GTE0},
1555 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1556 	{Opt_init_itable, 0, MOPT_GTE0},
1557 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1558 	{Opt_stripe, 0, MOPT_GTE0},
1559 	{Opt_resuid, 0, MOPT_GTE0},
1560 	{Opt_resgid, 0, MOPT_GTE0},
1561 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1562 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1563 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1564 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1565 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1566 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1567 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1568 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1569 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1570 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1571 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1572 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1573 #else
1574 	{Opt_acl, 0, MOPT_NOSUPPORT},
1575 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1576 #endif
1577 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1578 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1579 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1580 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1581 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1582 							MOPT_SET | MOPT_Q},
1583 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1584 							MOPT_SET | MOPT_Q},
1585 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1586 							MOPT_SET | MOPT_Q},
1587 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1588 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1589 							MOPT_CLEAR | MOPT_Q},
1590 	{Opt_usrjquota, 0, MOPT_Q},
1591 	{Opt_grpjquota, 0, MOPT_Q},
1592 	{Opt_offusrjquota, 0, MOPT_Q},
1593 	{Opt_offgrpjquota, 0, MOPT_Q},
1594 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1595 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1596 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1597 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1598 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1599 	{Opt_err, 0, 0}
1600 };
1601 
1602 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1603 			    substring_t *args, unsigned long *journal_devnum,
1604 			    unsigned int *journal_ioprio, int is_remount)
1605 {
1606 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1607 	const struct mount_opts *m;
1608 	kuid_t uid;
1609 	kgid_t gid;
1610 	int arg = 0;
1611 
1612 #ifdef CONFIG_QUOTA
1613 	if (token == Opt_usrjquota)
1614 		return set_qf_name(sb, USRQUOTA, &args[0]);
1615 	else if (token == Opt_grpjquota)
1616 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1617 	else if (token == Opt_offusrjquota)
1618 		return clear_qf_name(sb, USRQUOTA);
1619 	else if (token == Opt_offgrpjquota)
1620 		return clear_qf_name(sb, GRPQUOTA);
1621 #endif
1622 	switch (token) {
1623 	case Opt_noacl:
1624 	case Opt_nouser_xattr:
1625 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1626 		break;
1627 	case Opt_sb:
1628 		return 1;	/* handled by get_sb_block() */
1629 	case Opt_removed:
1630 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1631 		return 1;
1632 	case Opt_abort:
1633 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1634 		return 1;
1635 	case Opt_i_version:
1636 		sb->s_flags |= MS_I_VERSION;
1637 		return 1;
1638 	case Opt_lazytime:
1639 		sb->s_flags |= MS_LAZYTIME;
1640 		return 1;
1641 	case Opt_nolazytime:
1642 		sb->s_flags &= ~MS_LAZYTIME;
1643 		return 1;
1644 	}
1645 
1646 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1647 		if (token == m->token)
1648 			break;
1649 
1650 	if (m->token == Opt_err) {
1651 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1652 			 "or missing value", opt);
1653 		return -1;
1654 	}
1655 
1656 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1657 		ext4_msg(sb, KERN_ERR,
1658 			 "Mount option \"%s\" incompatible with ext2", opt);
1659 		return -1;
1660 	}
1661 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1662 		ext4_msg(sb, KERN_ERR,
1663 			 "Mount option \"%s\" incompatible with ext3", opt);
1664 		return -1;
1665 	}
1666 
1667 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1668 		return -1;
1669 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1670 		return -1;
1671 	if (m->flags & MOPT_EXPLICIT) {
1672 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1673 			set_opt2(sb, EXPLICIT_DELALLOC);
1674 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1675 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1676 		} else
1677 			return -1;
1678 	}
1679 	if (m->flags & MOPT_CLEAR_ERR)
1680 		clear_opt(sb, ERRORS_MASK);
1681 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1682 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1683 			 "options when quota turned on");
1684 		return -1;
1685 	}
1686 
1687 	if (m->flags & MOPT_NOSUPPORT) {
1688 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1689 	} else if (token == Opt_commit) {
1690 		if (arg == 0)
1691 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1692 		sbi->s_commit_interval = HZ * arg;
1693 	} else if (token == Opt_debug_want_extra_isize) {
1694 		sbi->s_want_extra_isize = arg;
1695 	} else if (token == Opt_max_batch_time) {
1696 		sbi->s_max_batch_time = arg;
1697 	} else if (token == Opt_min_batch_time) {
1698 		sbi->s_min_batch_time = arg;
1699 	} else if (token == Opt_inode_readahead_blks) {
1700 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1701 			ext4_msg(sb, KERN_ERR,
1702 				 "EXT4-fs: inode_readahead_blks must be "
1703 				 "0 or a power of 2 smaller than 2^31");
1704 			return -1;
1705 		}
1706 		sbi->s_inode_readahead_blks = arg;
1707 	} else if (token == Opt_init_itable) {
1708 		set_opt(sb, INIT_INODE_TABLE);
1709 		if (!args->from)
1710 			arg = EXT4_DEF_LI_WAIT_MULT;
1711 		sbi->s_li_wait_mult = arg;
1712 	} else if (token == Opt_max_dir_size_kb) {
1713 		sbi->s_max_dir_size_kb = arg;
1714 	} else if (token == Opt_stripe) {
1715 		sbi->s_stripe = arg;
1716 	} else if (token == Opt_resuid) {
1717 		uid = make_kuid(current_user_ns(), arg);
1718 		if (!uid_valid(uid)) {
1719 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1720 			return -1;
1721 		}
1722 		sbi->s_resuid = uid;
1723 	} else if (token == Opt_resgid) {
1724 		gid = make_kgid(current_user_ns(), arg);
1725 		if (!gid_valid(gid)) {
1726 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1727 			return -1;
1728 		}
1729 		sbi->s_resgid = gid;
1730 	} else if (token == Opt_journal_dev) {
1731 		if (is_remount) {
1732 			ext4_msg(sb, KERN_ERR,
1733 				 "Cannot specify journal on remount");
1734 			return -1;
1735 		}
1736 		*journal_devnum = arg;
1737 	} else if (token == Opt_journal_path) {
1738 		char *journal_path;
1739 		struct inode *journal_inode;
1740 		struct path path;
1741 		int error;
1742 
1743 		if (is_remount) {
1744 			ext4_msg(sb, KERN_ERR,
1745 				 "Cannot specify journal on remount");
1746 			return -1;
1747 		}
1748 		journal_path = match_strdup(&args[0]);
1749 		if (!journal_path) {
1750 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1751 				"journal device string");
1752 			return -1;
1753 		}
1754 
1755 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1756 		if (error) {
1757 			ext4_msg(sb, KERN_ERR, "error: could not find "
1758 				"journal device path: error %d", error);
1759 			kfree(journal_path);
1760 			return -1;
1761 		}
1762 
1763 		journal_inode = d_inode(path.dentry);
1764 		if (!S_ISBLK(journal_inode->i_mode)) {
1765 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1766 				"is not a block device", journal_path);
1767 			path_put(&path);
1768 			kfree(journal_path);
1769 			return -1;
1770 		}
1771 
1772 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1773 		path_put(&path);
1774 		kfree(journal_path);
1775 	} else if (token == Opt_journal_ioprio) {
1776 		if (arg > 7) {
1777 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1778 				 " (must be 0-7)");
1779 			return -1;
1780 		}
1781 		*journal_ioprio =
1782 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1783 	} else if (token == Opt_test_dummy_encryption) {
1784 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1785 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1786 		ext4_msg(sb, KERN_WARNING,
1787 			 "Test dummy encryption mode enabled");
1788 #else
1789 		ext4_msg(sb, KERN_WARNING,
1790 			 "Test dummy encryption mount option ignored");
1791 #endif
1792 	} else if (m->flags & MOPT_DATAJ) {
1793 		if (is_remount) {
1794 			if (!sbi->s_journal)
1795 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1796 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1797 				ext4_msg(sb, KERN_ERR,
1798 					 "Cannot change data mode on remount");
1799 				return -1;
1800 			}
1801 		} else {
1802 			clear_opt(sb, DATA_FLAGS);
1803 			sbi->s_mount_opt |= m->mount_opt;
1804 		}
1805 #ifdef CONFIG_QUOTA
1806 	} else if (m->flags & MOPT_QFMT) {
1807 		if (sb_any_quota_loaded(sb) &&
1808 		    sbi->s_jquota_fmt != m->mount_opt) {
1809 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1810 				 "quota options when quota turned on");
1811 			return -1;
1812 		}
1813 		if (ext4_has_feature_quota(sb)) {
1814 			ext4_msg(sb, KERN_INFO,
1815 				 "Quota format mount options ignored "
1816 				 "when QUOTA feature is enabled");
1817 			return 1;
1818 		}
1819 		sbi->s_jquota_fmt = m->mount_opt;
1820 #endif
1821 	} else if (token == Opt_dax) {
1822 #ifdef CONFIG_FS_DAX
1823 		ext4_msg(sb, KERN_WARNING,
1824 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1825 			sbi->s_mount_opt |= m->mount_opt;
1826 #else
1827 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1828 		return -1;
1829 #endif
1830 	} else if (token == Opt_data_err_abort) {
1831 		sbi->s_mount_opt |= m->mount_opt;
1832 	} else if (token == Opt_data_err_ignore) {
1833 		sbi->s_mount_opt &= ~m->mount_opt;
1834 	} else {
1835 		if (!args->from)
1836 			arg = 1;
1837 		if (m->flags & MOPT_CLEAR)
1838 			arg = !arg;
1839 		else if (unlikely(!(m->flags & MOPT_SET))) {
1840 			ext4_msg(sb, KERN_WARNING,
1841 				 "buggy handling of option %s", opt);
1842 			WARN_ON(1);
1843 			return -1;
1844 		}
1845 		if (arg != 0)
1846 			sbi->s_mount_opt |= m->mount_opt;
1847 		else
1848 			sbi->s_mount_opt &= ~m->mount_opt;
1849 	}
1850 	return 1;
1851 }
1852 
1853 static int parse_options(char *options, struct super_block *sb,
1854 			 unsigned long *journal_devnum,
1855 			 unsigned int *journal_ioprio,
1856 			 int is_remount)
1857 {
1858 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1859 	char *p;
1860 	substring_t args[MAX_OPT_ARGS];
1861 	int token;
1862 
1863 	if (!options)
1864 		return 1;
1865 
1866 	while ((p = strsep(&options, ",")) != NULL) {
1867 		if (!*p)
1868 			continue;
1869 		/*
1870 		 * Initialize args struct so we know whether arg was
1871 		 * found; some options take optional arguments.
1872 		 */
1873 		args[0].to = args[0].from = NULL;
1874 		token = match_token(p, tokens, args);
1875 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1876 				     journal_ioprio, is_remount) < 0)
1877 			return 0;
1878 	}
1879 #ifdef CONFIG_QUOTA
1880 	/*
1881 	 * We do the test below only for project quotas. 'usrquota' and
1882 	 * 'grpquota' mount options are allowed even without quota feature
1883 	 * to support legacy quotas in quota files.
1884 	 */
1885 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1886 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1887 			 "Cannot enable project quota enforcement.");
1888 		return 0;
1889 	}
1890 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1891 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1892 			clear_opt(sb, USRQUOTA);
1893 
1894 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1895 			clear_opt(sb, GRPQUOTA);
1896 
1897 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1898 			ext4_msg(sb, KERN_ERR, "old and new quota "
1899 					"format mixing");
1900 			return 0;
1901 		}
1902 
1903 		if (!sbi->s_jquota_fmt) {
1904 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1905 					"not specified");
1906 			return 0;
1907 		}
1908 	}
1909 #endif
1910 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1911 		int blocksize =
1912 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1913 
1914 		if (blocksize < PAGE_SIZE) {
1915 			ext4_msg(sb, KERN_ERR, "can't mount with "
1916 				 "dioread_nolock if block size != PAGE_SIZE");
1917 			return 0;
1918 		}
1919 	}
1920 	return 1;
1921 }
1922 
1923 static inline void ext4_show_quota_options(struct seq_file *seq,
1924 					   struct super_block *sb)
1925 {
1926 #if defined(CONFIG_QUOTA)
1927 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1928 
1929 	if (sbi->s_jquota_fmt) {
1930 		char *fmtname = "";
1931 
1932 		switch (sbi->s_jquota_fmt) {
1933 		case QFMT_VFS_OLD:
1934 			fmtname = "vfsold";
1935 			break;
1936 		case QFMT_VFS_V0:
1937 			fmtname = "vfsv0";
1938 			break;
1939 		case QFMT_VFS_V1:
1940 			fmtname = "vfsv1";
1941 			break;
1942 		}
1943 		seq_printf(seq, ",jqfmt=%s", fmtname);
1944 	}
1945 
1946 	if (sbi->s_qf_names[USRQUOTA])
1947 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1948 
1949 	if (sbi->s_qf_names[GRPQUOTA])
1950 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1951 #endif
1952 }
1953 
1954 static const char *token2str(int token)
1955 {
1956 	const struct match_token *t;
1957 
1958 	for (t = tokens; t->token != Opt_err; t++)
1959 		if (t->token == token && !strchr(t->pattern, '='))
1960 			break;
1961 	return t->pattern;
1962 }
1963 
1964 /*
1965  * Show an option if
1966  *  - it's set to a non-default value OR
1967  *  - if the per-sb default is different from the global default
1968  */
1969 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1970 			      int nodefs)
1971 {
1972 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1973 	struct ext4_super_block *es = sbi->s_es;
1974 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1975 	const struct mount_opts *m;
1976 	char sep = nodefs ? '\n' : ',';
1977 
1978 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1979 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1980 
1981 	if (sbi->s_sb_block != 1)
1982 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1983 
1984 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1985 		int want_set = m->flags & MOPT_SET;
1986 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1987 		    (m->flags & MOPT_CLEAR_ERR))
1988 			continue;
1989 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1990 			continue; /* skip if same as the default */
1991 		if ((want_set &&
1992 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1993 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1994 			continue; /* select Opt_noFoo vs Opt_Foo */
1995 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1996 	}
1997 
1998 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1999 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2000 		SEQ_OPTS_PRINT("resuid=%u",
2001 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2002 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2003 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2004 		SEQ_OPTS_PRINT("resgid=%u",
2005 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2006 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2007 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2008 		SEQ_OPTS_PUTS("errors=remount-ro");
2009 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2010 		SEQ_OPTS_PUTS("errors=continue");
2011 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2012 		SEQ_OPTS_PUTS("errors=panic");
2013 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2014 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2015 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2016 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2017 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2018 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2019 	if (sb->s_flags & MS_I_VERSION)
2020 		SEQ_OPTS_PUTS("i_version");
2021 	if (nodefs || sbi->s_stripe)
2022 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2023 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2024 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2025 			SEQ_OPTS_PUTS("data=journal");
2026 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2027 			SEQ_OPTS_PUTS("data=ordered");
2028 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2029 			SEQ_OPTS_PUTS("data=writeback");
2030 	}
2031 	if (nodefs ||
2032 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2033 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2034 			       sbi->s_inode_readahead_blks);
2035 
2036 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2037 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2038 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2039 	if (nodefs || sbi->s_max_dir_size_kb)
2040 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2041 	if (test_opt(sb, DATA_ERR_ABORT))
2042 		SEQ_OPTS_PUTS("data_err=abort");
2043 
2044 	ext4_show_quota_options(seq, sb);
2045 	return 0;
2046 }
2047 
2048 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2049 {
2050 	return _ext4_show_options(seq, root->d_sb, 0);
2051 }
2052 
2053 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2054 {
2055 	struct super_block *sb = seq->private;
2056 	int rc;
2057 
2058 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2059 	rc = _ext4_show_options(seq, sb, 1);
2060 	seq_puts(seq, "\n");
2061 	return rc;
2062 }
2063 
2064 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2065 			    int read_only)
2066 {
2067 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2068 	int res = 0;
2069 
2070 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2071 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2072 			 "forcing read-only mode");
2073 		res = MS_RDONLY;
2074 	}
2075 	if (read_only)
2076 		goto done;
2077 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2078 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2079 			 "running e2fsck is recommended");
2080 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2081 		ext4_msg(sb, KERN_WARNING,
2082 			 "warning: mounting fs with errors, "
2083 			 "running e2fsck is recommended");
2084 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2085 		 le16_to_cpu(es->s_mnt_count) >=
2086 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2087 		ext4_msg(sb, KERN_WARNING,
2088 			 "warning: maximal mount count reached, "
2089 			 "running e2fsck is recommended");
2090 	else if (le32_to_cpu(es->s_checkinterval) &&
2091 		(le32_to_cpu(es->s_lastcheck) +
2092 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2093 		ext4_msg(sb, KERN_WARNING,
2094 			 "warning: checktime reached, "
2095 			 "running e2fsck is recommended");
2096 	if (!sbi->s_journal)
2097 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2098 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2099 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2100 	le16_add_cpu(&es->s_mnt_count, 1);
2101 	es->s_mtime = cpu_to_le32(get_seconds());
2102 	ext4_update_dynamic_rev(sb);
2103 	if (sbi->s_journal)
2104 		ext4_set_feature_journal_needs_recovery(sb);
2105 
2106 	ext4_commit_super(sb, 1);
2107 done:
2108 	if (test_opt(sb, DEBUG))
2109 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2110 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2111 			sb->s_blocksize,
2112 			sbi->s_groups_count,
2113 			EXT4_BLOCKS_PER_GROUP(sb),
2114 			EXT4_INODES_PER_GROUP(sb),
2115 			sbi->s_mount_opt, sbi->s_mount_opt2);
2116 
2117 	cleancache_init_fs(sb);
2118 	return res;
2119 }
2120 
2121 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2122 {
2123 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2124 	struct flex_groups *new_groups;
2125 	int size;
2126 
2127 	if (!sbi->s_log_groups_per_flex)
2128 		return 0;
2129 
2130 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2131 	if (size <= sbi->s_flex_groups_allocated)
2132 		return 0;
2133 
2134 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2135 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2136 	if (!new_groups) {
2137 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2138 			 size / (int) sizeof(struct flex_groups));
2139 		return -ENOMEM;
2140 	}
2141 
2142 	if (sbi->s_flex_groups) {
2143 		memcpy(new_groups, sbi->s_flex_groups,
2144 		       (sbi->s_flex_groups_allocated *
2145 			sizeof(struct flex_groups)));
2146 		kvfree(sbi->s_flex_groups);
2147 	}
2148 	sbi->s_flex_groups = new_groups;
2149 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2150 	return 0;
2151 }
2152 
2153 static int ext4_fill_flex_info(struct super_block *sb)
2154 {
2155 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2156 	struct ext4_group_desc *gdp = NULL;
2157 	ext4_group_t flex_group;
2158 	int i, err;
2159 
2160 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2161 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2162 		sbi->s_log_groups_per_flex = 0;
2163 		return 1;
2164 	}
2165 
2166 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2167 	if (err)
2168 		goto failed;
2169 
2170 	for (i = 0; i < sbi->s_groups_count; i++) {
2171 		gdp = ext4_get_group_desc(sb, i, NULL);
2172 
2173 		flex_group = ext4_flex_group(sbi, i);
2174 		atomic_add(ext4_free_inodes_count(sb, gdp),
2175 			   &sbi->s_flex_groups[flex_group].free_inodes);
2176 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2177 			     &sbi->s_flex_groups[flex_group].free_clusters);
2178 		atomic_add(ext4_used_dirs_count(sb, gdp),
2179 			   &sbi->s_flex_groups[flex_group].used_dirs);
2180 	}
2181 
2182 	return 1;
2183 failed:
2184 	return 0;
2185 }
2186 
2187 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2188 				   struct ext4_group_desc *gdp)
2189 {
2190 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2191 	__u16 crc = 0;
2192 	__le32 le_group = cpu_to_le32(block_group);
2193 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2194 
2195 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2196 		/* Use new metadata_csum algorithm */
2197 		__u32 csum32;
2198 		__u16 dummy_csum = 0;
2199 
2200 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2201 				     sizeof(le_group));
2202 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2203 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2204 				     sizeof(dummy_csum));
2205 		offset += sizeof(dummy_csum);
2206 		if (offset < sbi->s_desc_size)
2207 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2208 					     sbi->s_desc_size - offset);
2209 
2210 		crc = csum32 & 0xFFFF;
2211 		goto out;
2212 	}
2213 
2214 	/* old crc16 code */
2215 	if (!ext4_has_feature_gdt_csum(sb))
2216 		return 0;
2217 
2218 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2219 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2220 	crc = crc16(crc, (__u8 *)gdp, offset);
2221 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2222 	/* for checksum of struct ext4_group_desc do the rest...*/
2223 	if (ext4_has_feature_64bit(sb) &&
2224 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2225 		crc = crc16(crc, (__u8 *)gdp + offset,
2226 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2227 				offset);
2228 
2229 out:
2230 	return cpu_to_le16(crc);
2231 }
2232 
2233 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2234 				struct ext4_group_desc *gdp)
2235 {
2236 	if (ext4_has_group_desc_csum(sb) &&
2237 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2238 		return 0;
2239 
2240 	return 1;
2241 }
2242 
2243 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2244 			      struct ext4_group_desc *gdp)
2245 {
2246 	if (!ext4_has_group_desc_csum(sb))
2247 		return;
2248 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2249 }
2250 
2251 /* Called at mount-time, super-block is locked */
2252 static int ext4_check_descriptors(struct super_block *sb,
2253 				  ext4_fsblk_t sb_block,
2254 				  ext4_group_t *first_not_zeroed)
2255 {
2256 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2257 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2258 	ext4_fsblk_t last_block;
2259 	ext4_fsblk_t block_bitmap;
2260 	ext4_fsblk_t inode_bitmap;
2261 	ext4_fsblk_t inode_table;
2262 	int flexbg_flag = 0;
2263 	ext4_group_t i, grp = sbi->s_groups_count;
2264 
2265 	if (ext4_has_feature_flex_bg(sb))
2266 		flexbg_flag = 1;
2267 
2268 	ext4_debug("Checking group descriptors");
2269 
2270 	for (i = 0; i < sbi->s_groups_count; i++) {
2271 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2272 
2273 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2274 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2275 		else
2276 			last_block = first_block +
2277 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2278 
2279 		if ((grp == sbi->s_groups_count) &&
2280 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2281 			grp = i;
2282 
2283 		block_bitmap = ext4_block_bitmap(sb, gdp);
2284 		if (block_bitmap == sb_block) {
2285 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2286 				 "Block bitmap for group %u overlaps "
2287 				 "superblock", i);
2288 		}
2289 		if (block_bitmap < first_block || block_bitmap > last_block) {
2290 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2291 			       "Block bitmap for group %u not in group "
2292 			       "(block %llu)!", i, block_bitmap);
2293 			return 0;
2294 		}
2295 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2296 		if (inode_bitmap == sb_block) {
2297 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2298 				 "Inode bitmap for group %u overlaps "
2299 				 "superblock", i);
2300 		}
2301 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2302 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2303 			       "Inode bitmap for group %u not in group "
2304 			       "(block %llu)!", i, inode_bitmap);
2305 			return 0;
2306 		}
2307 		inode_table = ext4_inode_table(sb, gdp);
2308 		if (inode_table == sb_block) {
2309 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2310 				 "Inode table for group %u overlaps "
2311 				 "superblock", i);
2312 		}
2313 		if (inode_table < first_block ||
2314 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2315 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2316 			       "Inode table for group %u not in group "
2317 			       "(block %llu)!", i, inode_table);
2318 			return 0;
2319 		}
2320 		ext4_lock_group(sb, i);
2321 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2322 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2323 				 "Checksum for group %u failed (%u!=%u)",
2324 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2325 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2326 			if (!(sb->s_flags & MS_RDONLY)) {
2327 				ext4_unlock_group(sb, i);
2328 				return 0;
2329 			}
2330 		}
2331 		ext4_unlock_group(sb, i);
2332 		if (!flexbg_flag)
2333 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2334 	}
2335 	if (NULL != first_not_zeroed)
2336 		*first_not_zeroed = grp;
2337 	return 1;
2338 }
2339 
2340 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2341  * the superblock) which were deleted from all directories, but held open by
2342  * a process at the time of a crash.  We walk the list and try to delete these
2343  * inodes at recovery time (only with a read-write filesystem).
2344  *
2345  * In order to keep the orphan inode chain consistent during traversal (in
2346  * case of crash during recovery), we link each inode into the superblock
2347  * orphan list_head and handle it the same way as an inode deletion during
2348  * normal operation (which journals the operations for us).
2349  *
2350  * We only do an iget() and an iput() on each inode, which is very safe if we
2351  * accidentally point at an in-use or already deleted inode.  The worst that
2352  * can happen in this case is that we get a "bit already cleared" message from
2353  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2354  * e2fsck was run on this filesystem, and it must have already done the orphan
2355  * inode cleanup for us, so we can safely abort without any further action.
2356  */
2357 static void ext4_orphan_cleanup(struct super_block *sb,
2358 				struct ext4_super_block *es)
2359 {
2360 	unsigned int s_flags = sb->s_flags;
2361 	int ret, nr_orphans = 0, nr_truncates = 0;
2362 #ifdef CONFIG_QUOTA
2363 	int i;
2364 #endif
2365 	if (!es->s_last_orphan) {
2366 		jbd_debug(4, "no orphan inodes to clean up\n");
2367 		return;
2368 	}
2369 
2370 	if (bdev_read_only(sb->s_bdev)) {
2371 		ext4_msg(sb, KERN_ERR, "write access "
2372 			"unavailable, skipping orphan cleanup");
2373 		return;
2374 	}
2375 
2376 	/* Check if feature set would not allow a r/w mount */
2377 	if (!ext4_feature_set_ok(sb, 0)) {
2378 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2379 			 "unknown ROCOMPAT features");
2380 		return;
2381 	}
2382 
2383 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2384 		/* don't clear list on RO mount w/ errors */
2385 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2386 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2387 				  "clearing orphan list.\n");
2388 			es->s_last_orphan = 0;
2389 		}
2390 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2391 		return;
2392 	}
2393 
2394 	if (s_flags & MS_RDONLY) {
2395 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2396 		sb->s_flags &= ~MS_RDONLY;
2397 	}
2398 #ifdef CONFIG_QUOTA
2399 	/* Needed for iput() to work correctly and not trash data */
2400 	sb->s_flags |= MS_ACTIVE;
2401 	/* Turn on quotas so that they are updated correctly */
2402 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2403 		if (EXT4_SB(sb)->s_qf_names[i]) {
2404 			int ret = ext4_quota_on_mount(sb, i);
2405 			if (ret < 0)
2406 				ext4_msg(sb, KERN_ERR,
2407 					"Cannot turn on journaled "
2408 					"quota: error %d", ret);
2409 		}
2410 	}
2411 #endif
2412 
2413 	while (es->s_last_orphan) {
2414 		struct inode *inode;
2415 
2416 		/*
2417 		 * We may have encountered an error during cleanup; if
2418 		 * so, skip the rest.
2419 		 */
2420 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2421 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2422 			es->s_last_orphan = 0;
2423 			break;
2424 		}
2425 
2426 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2427 		if (IS_ERR(inode)) {
2428 			es->s_last_orphan = 0;
2429 			break;
2430 		}
2431 
2432 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2433 		dquot_initialize(inode);
2434 		if (inode->i_nlink) {
2435 			if (test_opt(sb, DEBUG))
2436 				ext4_msg(sb, KERN_DEBUG,
2437 					"%s: truncating inode %lu to %lld bytes",
2438 					__func__, inode->i_ino, inode->i_size);
2439 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2440 				  inode->i_ino, inode->i_size);
2441 			inode_lock(inode);
2442 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2443 			ret = ext4_truncate(inode);
2444 			if (ret)
2445 				ext4_std_error(inode->i_sb, ret);
2446 			inode_unlock(inode);
2447 			nr_truncates++;
2448 		} else {
2449 			if (test_opt(sb, DEBUG))
2450 				ext4_msg(sb, KERN_DEBUG,
2451 					"%s: deleting unreferenced inode %lu",
2452 					__func__, inode->i_ino);
2453 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2454 				  inode->i_ino);
2455 			nr_orphans++;
2456 		}
2457 		iput(inode);  /* The delete magic happens here! */
2458 	}
2459 
2460 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2461 
2462 	if (nr_orphans)
2463 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2464 		       PLURAL(nr_orphans));
2465 	if (nr_truncates)
2466 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2467 		       PLURAL(nr_truncates));
2468 #ifdef CONFIG_QUOTA
2469 	/* Turn quotas off */
2470 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2471 		if (sb_dqopt(sb)->files[i])
2472 			dquot_quota_off(sb, i);
2473 	}
2474 #endif
2475 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2476 }
2477 
2478 /*
2479  * Maximal extent format file size.
2480  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2481  * extent format containers, within a sector_t, and within i_blocks
2482  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2483  * so that won't be a limiting factor.
2484  *
2485  * However there is other limiting factor. We do store extents in the form
2486  * of starting block and length, hence the resulting length of the extent
2487  * covering maximum file size must fit into on-disk format containers as
2488  * well. Given that length is always by 1 unit bigger than max unit (because
2489  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2490  *
2491  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2492  */
2493 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2494 {
2495 	loff_t res;
2496 	loff_t upper_limit = MAX_LFS_FILESIZE;
2497 
2498 	/* small i_blocks in vfs inode? */
2499 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2500 		/*
2501 		 * CONFIG_LBDAF is not enabled implies the inode
2502 		 * i_block represent total blocks in 512 bytes
2503 		 * 32 == size of vfs inode i_blocks * 8
2504 		 */
2505 		upper_limit = (1LL << 32) - 1;
2506 
2507 		/* total blocks in file system block size */
2508 		upper_limit >>= (blkbits - 9);
2509 		upper_limit <<= blkbits;
2510 	}
2511 
2512 	/*
2513 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2514 	 * by one fs block, so ee_len can cover the extent of maximum file
2515 	 * size
2516 	 */
2517 	res = (1LL << 32) - 1;
2518 	res <<= blkbits;
2519 
2520 	/* Sanity check against vm- & vfs- imposed limits */
2521 	if (res > upper_limit)
2522 		res = upper_limit;
2523 
2524 	return res;
2525 }
2526 
2527 /*
2528  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2529  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2530  * We need to be 1 filesystem block less than the 2^48 sector limit.
2531  */
2532 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2533 {
2534 	loff_t res = EXT4_NDIR_BLOCKS;
2535 	int meta_blocks;
2536 	loff_t upper_limit;
2537 	/* This is calculated to be the largest file size for a dense, block
2538 	 * mapped file such that the file's total number of 512-byte sectors,
2539 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2540 	 *
2541 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2542 	 * number of 512-byte sectors of the file.
2543 	 */
2544 
2545 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2546 		/*
2547 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2548 		 * the inode i_block field represents total file blocks in
2549 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2550 		 */
2551 		upper_limit = (1LL << 32) - 1;
2552 
2553 		/* total blocks in file system block size */
2554 		upper_limit >>= (bits - 9);
2555 
2556 	} else {
2557 		/*
2558 		 * We use 48 bit ext4_inode i_blocks
2559 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2560 		 * represent total number of blocks in
2561 		 * file system block size
2562 		 */
2563 		upper_limit = (1LL << 48) - 1;
2564 
2565 	}
2566 
2567 	/* indirect blocks */
2568 	meta_blocks = 1;
2569 	/* double indirect blocks */
2570 	meta_blocks += 1 + (1LL << (bits-2));
2571 	/* tripple indirect blocks */
2572 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2573 
2574 	upper_limit -= meta_blocks;
2575 	upper_limit <<= bits;
2576 
2577 	res += 1LL << (bits-2);
2578 	res += 1LL << (2*(bits-2));
2579 	res += 1LL << (3*(bits-2));
2580 	res <<= bits;
2581 	if (res > upper_limit)
2582 		res = upper_limit;
2583 
2584 	if (res > MAX_LFS_FILESIZE)
2585 		res = MAX_LFS_FILESIZE;
2586 
2587 	return res;
2588 }
2589 
2590 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2591 				   ext4_fsblk_t logical_sb_block, int nr)
2592 {
2593 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2594 	ext4_group_t bg, first_meta_bg;
2595 	int has_super = 0;
2596 
2597 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2598 
2599 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2600 		return logical_sb_block + nr + 1;
2601 	bg = sbi->s_desc_per_block * nr;
2602 	if (ext4_bg_has_super(sb, bg))
2603 		has_super = 1;
2604 
2605 	/*
2606 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2607 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2608 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2609 	 * compensate.
2610 	 */
2611 	if (sb->s_blocksize == 1024 && nr == 0 &&
2612 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2613 		has_super++;
2614 
2615 	return (has_super + ext4_group_first_block_no(sb, bg));
2616 }
2617 
2618 /**
2619  * ext4_get_stripe_size: Get the stripe size.
2620  * @sbi: In memory super block info
2621  *
2622  * If we have specified it via mount option, then
2623  * use the mount option value. If the value specified at mount time is
2624  * greater than the blocks per group use the super block value.
2625  * If the super block value is greater than blocks per group return 0.
2626  * Allocator needs it be less than blocks per group.
2627  *
2628  */
2629 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2630 {
2631 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2632 	unsigned long stripe_width =
2633 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2634 	int ret;
2635 
2636 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2637 		ret = sbi->s_stripe;
2638 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2639 		ret = stripe_width;
2640 	else if (stride && stride <= sbi->s_blocks_per_group)
2641 		ret = stride;
2642 	else
2643 		ret = 0;
2644 
2645 	/*
2646 	 * If the stripe width is 1, this makes no sense and
2647 	 * we set it to 0 to turn off stripe handling code.
2648 	 */
2649 	if (ret <= 1)
2650 		ret = 0;
2651 
2652 	return ret;
2653 }
2654 
2655 /*
2656  * Check whether this filesystem can be mounted based on
2657  * the features present and the RDONLY/RDWR mount requested.
2658  * Returns 1 if this filesystem can be mounted as requested,
2659  * 0 if it cannot be.
2660  */
2661 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2662 {
2663 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2664 		ext4_msg(sb, KERN_ERR,
2665 			"Couldn't mount because of "
2666 			"unsupported optional features (%x)",
2667 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2668 			~EXT4_FEATURE_INCOMPAT_SUPP));
2669 		return 0;
2670 	}
2671 
2672 	if (readonly)
2673 		return 1;
2674 
2675 	if (ext4_has_feature_readonly(sb)) {
2676 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2677 		sb->s_flags |= MS_RDONLY;
2678 		return 1;
2679 	}
2680 
2681 	/* Check that feature set is OK for a read-write mount */
2682 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2683 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2684 			 "unsupported optional features (%x)",
2685 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2686 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2687 		return 0;
2688 	}
2689 	/*
2690 	 * Large file size enabled file system can only be mounted
2691 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2692 	 */
2693 	if (ext4_has_feature_huge_file(sb)) {
2694 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2695 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2696 				 "cannot be mounted RDWR without "
2697 				 "CONFIG_LBDAF");
2698 			return 0;
2699 		}
2700 	}
2701 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2702 		ext4_msg(sb, KERN_ERR,
2703 			 "Can't support bigalloc feature without "
2704 			 "extents feature\n");
2705 		return 0;
2706 	}
2707 
2708 #ifndef CONFIG_QUOTA
2709 	if (ext4_has_feature_quota(sb) && !readonly) {
2710 		ext4_msg(sb, KERN_ERR,
2711 			 "Filesystem with quota feature cannot be mounted RDWR "
2712 			 "without CONFIG_QUOTA");
2713 		return 0;
2714 	}
2715 	if (ext4_has_feature_project(sb) && !readonly) {
2716 		ext4_msg(sb, KERN_ERR,
2717 			 "Filesystem with project quota feature cannot be mounted RDWR "
2718 			 "without CONFIG_QUOTA");
2719 		return 0;
2720 	}
2721 #endif  /* CONFIG_QUOTA */
2722 	return 1;
2723 }
2724 
2725 /*
2726  * This function is called once a day if we have errors logged
2727  * on the file system
2728  */
2729 static void print_daily_error_info(unsigned long arg)
2730 {
2731 	struct super_block *sb = (struct super_block *) arg;
2732 	struct ext4_sb_info *sbi;
2733 	struct ext4_super_block *es;
2734 
2735 	sbi = EXT4_SB(sb);
2736 	es = sbi->s_es;
2737 
2738 	if (es->s_error_count)
2739 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2740 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2741 			 le32_to_cpu(es->s_error_count));
2742 	if (es->s_first_error_time) {
2743 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2744 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2745 		       (int) sizeof(es->s_first_error_func),
2746 		       es->s_first_error_func,
2747 		       le32_to_cpu(es->s_first_error_line));
2748 		if (es->s_first_error_ino)
2749 			printk(KERN_CONT ": inode %u",
2750 			       le32_to_cpu(es->s_first_error_ino));
2751 		if (es->s_first_error_block)
2752 			printk(KERN_CONT ": block %llu", (unsigned long long)
2753 			       le64_to_cpu(es->s_first_error_block));
2754 		printk(KERN_CONT "\n");
2755 	}
2756 	if (es->s_last_error_time) {
2757 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2758 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2759 		       (int) sizeof(es->s_last_error_func),
2760 		       es->s_last_error_func,
2761 		       le32_to_cpu(es->s_last_error_line));
2762 		if (es->s_last_error_ino)
2763 			printk(KERN_CONT ": inode %u",
2764 			       le32_to_cpu(es->s_last_error_ino));
2765 		if (es->s_last_error_block)
2766 			printk(KERN_CONT ": block %llu", (unsigned long long)
2767 			       le64_to_cpu(es->s_last_error_block));
2768 		printk(KERN_CONT "\n");
2769 	}
2770 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2771 }
2772 
2773 /* Find next suitable group and run ext4_init_inode_table */
2774 static int ext4_run_li_request(struct ext4_li_request *elr)
2775 {
2776 	struct ext4_group_desc *gdp = NULL;
2777 	ext4_group_t group, ngroups;
2778 	struct super_block *sb;
2779 	unsigned long timeout = 0;
2780 	int ret = 0;
2781 
2782 	sb = elr->lr_super;
2783 	ngroups = EXT4_SB(sb)->s_groups_count;
2784 
2785 	for (group = elr->lr_next_group; group < ngroups; group++) {
2786 		gdp = ext4_get_group_desc(sb, group, NULL);
2787 		if (!gdp) {
2788 			ret = 1;
2789 			break;
2790 		}
2791 
2792 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2793 			break;
2794 	}
2795 
2796 	if (group >= ngroups)
2797 		ret = 1;
2798 
2799 	if (!ret) {
2800 		timeout = jiffies;
2801 		ret = ext4_init_inode_table(sb, group,
2802 					    elr->lr_timeout ? 0 : 1);
2803 		if (elr->lr_timeout == 0) {
2804 			timeout = (jiffies - timeout) *
2805 				  elr->lr_sbi->s_li_wait_mult;
2806 			elr->lr_timeout = timeout;
2807 		}
2808 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2809 		elr->lr_next_group = group + 1;
2810 	}
2811 	return ret;
2812 }
2813 
2814 /*
2815  * Remove lr_request from the list_request and free the
2816  * request structure. Should be called with li_list_mtx held
2817  */
2818 static void ext4_remove_li_request(struct ext4_li_request *elr)
2819 {
2820 	struct ext4_sb_info *sbi;
2821 
2822 	if (!elr)
2823 		return;
2824 
2825 	sbi = elr->lr_sbi;
2826 
2827 	list_del(&elr->lr_request);
2828 	sbi->s_li_request = NULL;
2829 	kfree(elr);
2830 }
2831 
2832 static void ext4_unregister_li_request(struct super_block *sb)
2833 {
2834 	mutex_lock(&ext4_li_mtx);
2835 	if (!ext4_li_info) {
2836 		mutex_unlock(&ext4_li_mtx);
2837 		return;
2838 	}
2839 
2840 	mutex_lock(&ext4_li_info->li_list_mtx);
2841 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2842 	mutex_unlock(&ext4_li_info->li_list_mtx);
2843 	mutex_unlock(&ext4_li_mtx);
2844 }
2845 
2846 static struct task_struct *ext4_lazyinit_task;
2847 
2848 /*
2849  * This is the function where ext4lazyinit thread lives. It walks
2850  * through the request list searching for next scheduled filesystem.
2851  * When such a fs is found, run the lazy initialization request
2852  * (ext4_rn_li_request) and keep track of the time spend in this
2853  * function. Based on that time we compute next schedule time of
2854  * the request. When walking through the list is complete, compute
2855  * next waking time and put itself into sleep.
2856  */
2857 static int ext4_lazyinit_thread(void *arg)
2858 {
2859 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2860 	struct list_head *pos, *n;
2861 	struct ext4_li_request *elr;
2862 	unsigned long next_wakeup, cur;
2863 
2864 	BUG_ON(NULL == eli);
2865 
2866 cont_thread:
2867 	while (true) {
2868 		next_wakeup = MAX_JIFFY_OFFSET;
2869 
2870 		mutex_lock(&eli->li_list_mtx);
2871 		if (list_empty(&eli->li_request_list)) {
2872 			mutex_unlock(&eli->li_list_mtx);
2873 			goto exit_thread;
2874 		}
2875 		list_for_each_safe(pos, n, &eli->li_request_list) {
2876 			int err = 0;
2877 			int progress = 0;
2878 			elr = list_entry(pos, struct ext4_li_request,
2879 					 lr_request);
2880 
2881 			if (time_before(jiffies, elr->lr_next_sched)) {
2882 				if (time_before(elr->lr_next_sched, next_wakeup))
2883 					next_wakeup = elr->lr_next_sched;
2884 				continue;
2885 			}
2886 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2887 				if (sb_start_write_trylock(elr->lr_super)) {
2888 					progress = 1;
2889 					/*
2890 					 * We hold sb->s_umount, sb can not
2891 					 * be removed from the list, it is
2892 					 * now safe to drop li_list_mtx
2893 					 */
2894 					mutex_unlock(&eli->li_list_mtx);
2895 					err = ext4_run_li_request(elr);
2896 					sb_end_write(elr->lr_super);
2897 					mutex_lock(&eli->li_list_mtx);
2898 					n = pos->next;
2899 				}
2900 				up_read((&elr->lr_super->s_umount));
2901 			}
2902 			/* error, remove the lazy_init job */
2903 			if (err) {
2904 				ext4_remove_li_request(elr);
2905 				continue;
2906 			}
2907 			if (!progress) {
2908 				elr->lr_next_sched = jiffies +
2909 					(prandom_u32()
2910 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2911 			}
2912 			if (time_before(elr->lr_next_sched, next_wakeup))
2913 				next_wakeup = elr->lr_next_sched;
2914 		}
2915 		mutex_unlock(&eli->li_list_mtx);
2916 
2917 		try_to_freeze();
2918 
2919 		cur = jiffies;
2920 		if ((time_after_eq(cur, next_wakeup)) ||
2921 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2922 			cond_resched();
2923 			continue;
2924 		}
2925 
2926 		schedule_timeout_interruptible(next_wakeup - cur);
2927 
2928 		if (kthread_should_stop()) {
2929 			ext4_clear_request_list();
2930 			goto exit_thread;
2931 		}
2932 	}
2933 
2934 exit_thread:
2935 	/*
2936 	 * It looks like the request list is empty, but we need
2937 	 * to check it under the li_list_mtx lock, to prevent any
2938 	 * additions into it, and of course we should lock ext4_li_mtx
2939 	 * to atomically free the list and ext4_li_info, because at
2940 	 * this point another ext4 filesystem could be registering
2941 	 * new one.
2942 	 */
2943 	mutex_lock(&ext4_li_mtx);
2944 	mutex_lock(&eli->li_list_mtx);
2945 	if (!list_empty(&eli->li_request_list)) {
2946 		mutex_unlock(&eli->li_list_mtx);
2947 		mutex_unlock(&ext4_li_mtx);
2948 		goto cont_thread;
2949 	}
2950 	mutex_unlock(&eli->li_list_mtx);
2951 	kfree(ext4_li_info);
2952 	ext4_li_info = NULL;
2953 	mutex_unlock(&ext4_li_mtx);
2954 
2955 	return 0;
2956 }
2957 
2958 static void ext4_clear_request_list(void)
2959 {
2960 	struct list_head *pos, *n;
2961 	struct ext4_li_request *elr;
2962 
2963 	mutex_lock(&ext4_li_info->li_list_mtx);
2964 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2965 		elr = list_entry(pos, struct ext4_li_request,
2966 				 lr_request);
2967 		ext4_remove_li_request(elr);
2968 	}
2969 	mutex_unlock(&ext4_li_info->li_list_mtx);
2970 }
2971 
2972 static int ext4_run_lazyinit_thread(void)
2973 {
2974 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2975 					 ext4_li_info, "ext4lazyinit");
2976 	if (IS_ERR(ext4_lazyinit_task)) {
2977 		int err = PTR_ERR(ext4_lazyinit_task);
2978 		ext4_clear_request_list();
2979 		kfree(ext4_li_info);
2980 		ext4_li_info = NULL;
2981 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2982 				 "initialization thread\n",
2983 				 err);
2984 		return err;
2985 	}
2986 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2987 	return 0;
2988 }
2989 
2990 /*
2991  * Check whether it make sense to run itable init. thread or not.
2992  * If there is at least one uninitialized inode table, return
2993  * corresponding group number, else the loop goes through all
2994  * groups and return total number of groups.
2995  */
2996 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2997 {
2998 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2999 	struct ext4_group_desc *gdp = NULL;
3000 
3001 	for (group = 0; group < ngroups; group++) {
3002 		gdp = ext4_get_group_desc(sb, group, NULL);
3003 		if (!gdp)
3004 			continue;
3005 
3006 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3007 			break;
3008 	}
3009 
3010 	return group;
3011 }
3012 
3013 static int ext4_li_info_new(void)
3014 {
3015 	struct ext4_lazy_init *eli = NULL;
3016 
3017 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3018 	if (!eli)
3019 		return -ENOMEM;
3020 
3021 	INIT_LIST_HEAD(&eli->li_request_list);
3022 	mutex_init(&eli->li_list_mtx);
3023 
3024 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3025 
3026 	ext4_li_info = eli;
3027 
3028 	return 0;
3029 }
3030 
3031 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3032 					    ext4_group_t start)
3033 {
3034 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3035 	struct ext4_li_request *elr;
3036 
3037 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3038 	if (!elr)
3039 		return NULL;
3040 
3041 	elr->lr_super = sb;
3042 	elr->lr_sbi = sbi;
3043 	elr->lr_next_group = start;
3044 
3045 	/*
3046 	 * Randomize first schedule time of the request to
3047 	 * spread the inode table initialization requests
3048 	 * better.
3049 	 */
3050 	elr->lr_next_sched = jiffies + (prandom_u32() %
3051 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3052 	return elr;
3053 }
3054 
3055 int ext4_register_li_request(struct super_block *sb,
3056 			     ext4_group_t first_not_zeroed)
3057 {
3058 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3059 	struct ext4_li_request *elr = NULL;
3060 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3061 	int ret = 0;
3062 
3063 	mutex_lock(&ext4_li_mtx);
3064 	if (sbi->s_li_request != NULL) {
3065 		/*
3066 		 * Reset timeout so it can be computed again, because
3067 		 * s_li_wait_mult might have changed.
3068 		 */
3069 		sbi->s_li_request->lr_timeout = 0;
3070 		goto out;
3071 	}
3072 
3073 	if (first_not_zeroed == ngroups ||
3074 	    (sb->s_flags & MS_RDONLY) ||
3075 	    !test_opt(sb, INIT_INODE_TABLE))
3076 		goto out;
3077 
3078 	elr = ext4_li_request_new(sb, first_not_zeroed);
3079 	if (!elr) {
3080 		ret = -ENOMEM;
3081 		goto out;
3082 	}
3083 
3084 	if (NULL == ext4_li_info) {
3085 		ret = ext4_li_info_new();
3086 		if (ret)
3087 			goto out;
3088 	}
3089 
3090 	mutex_lock(&ext4_li_info->li_list_mtx);
3091 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3092 	mutex_unlock(&ext4_li_info->li_list_mtx);
3093 
3094 	sbi->s_li_request = elr;
3095 	/*
3096 	 * set elr to NULL here since it has been inserted to
3097 	 * the request_list and the removal and free of it is
3098 	 * handled by ext4_clear_request_list from now on.
3099 	 */
3100 	elr = NULL;
3101 
3102 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3103 		ret = ext4_run_lazyinit_thread();
3104 		if (ret)
3105 			goto out;
3106 	}
3107 out:
3108 	mutex_unlock(&ext4_li_mtx);
3109 	if (ret)
3110 		kfree(elr);
3111 	return ret;
3112 }
3113 
3114 /*
3115  * We do not need to lock anything since this is called on
3116  * module unload.
3117  */
3118 static void ext4_destroy_lazyinit_thread(void)
3119 {
3120 	/*
3121 	 * If thread exited earlier
3122 	 * there's nothing to be done.
3123 	 */
3124 	if (!ext4_li_info || !ext4_lazyinit_task)
3125 		return;
3126 
3127 	kthread_stop(ext4_lazyinit_task);
3128 }
3129 
3130 static int set_journal_csum_feature_set(struct super_block *sb)
3131 {
3132 	int ret = 1;
3133 	int compat, incompat;
3134 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3135 
3136 	if (ext4_has_metadata_csum(sb)) {
3137 		/* journal checksum v3 */
3138 		compat = 0;
3139 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3140 	} else {
3141 		/* journal checksum v1 */
3142 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3143 		incompat = 0;
3144 	}
3145 
3146 	jbd2_journal_clear_features(sbi->s_journal,
3147 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3148 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3149 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3150 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3151 		ret = jbd2_journal_set_features(sbi->s_journal,
3152 				compat, 0,
3153 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3154 				incompat);
3155 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3156 		ret = jbd2_journal_set_features(sbi->s_journal,
3157 				compat, 0,
3158 				incompat);
3159 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3160 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3161 	} else {
3162 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3163 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3164 	}
3165 
3166 	return ret;
3167 }
3168 
3169 /*
3170  * Note: calculating the overhead so we can be compatible with
3171  * historical BSD practice is quite difficult in the face of
3172  * clusters/bigalloc.  This is because multiple metadata blocks from
3173  * different block group can end up in the same allocation cluster.
3174  * Calculating the exact overhead in the face of clustered allocation
3175  * requires either O(all block bitmaps) in memory or O(number of block
3176  * groups**2) in time.  We will still calculate the superblock for
3177  * older file systems --- and if we come across with a bigalloc file
3178  * system with zero in s_overhead_clusters the estimate will be close to
3179  * correct especially for very large cluster sizes --- but for newer
3180  * file systems, it's better to calculate this figure once at mkfs
3181  * time, and store it in the superblock.  If the superblock value is
3182  * present (even for non-bigalloc file systems), we will use it.
3183  */
3184 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3185 			  char *buf)
3186 {
3187 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3188 	struct ext4_group_desc	*gdp;
3189 	ext4_fsblk_t		first_block, last_block, b;
3190 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3191 	int			s, j, count = 0;
3192 
3193 	if (!ext4_has_feature_bigalloc(sb))
3194 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3195 			sbi->s_itb_per_group + 2);
3196 
3197 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3198 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3199 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3200 	for (i = 0; i < ngroups; i++) {
3201 		gdp = ext4_get_group_desc(sb, i, NULL);
3202 		b = ext4_block_bitmap(sb, gdp);
3203 		if (b >= first_block && b <= last_block) {
3204 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3205 			count++;
3206 		}
3207 		b = ext4_inode_bitmap(sb, gdp);
3208 		if (b >= first_block && b <= last_block) {
3209 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3210 			count++;
3211 		}
3212 		b = ext4_inode_table(sb, gdp);
3213 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3214 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3215 				int c = EXT4_B2C(sbi, b - first_block);
3216 				ext4_set_bit(c, buf);
3217 				count++;
3218 			}
3219 		if (i != grp)
3220 			continue;
3221 		s = 0;
3222 		if (ext4_bg_has_super(sb, grp)) {
3223 			ext4_set_bit(s++, buf);
3224 			count++;
3225 		}
3226 		j = ext4_bg_num_gdb(sb, grp);
3227 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3228 			ext4_error(sb, "Invalid number of block group "
3229 				   "descriptor blocks: %d", j);
3230 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3231 		}
3232 		count += j;
3233 		for (; j > 0; j--)
3234 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3235 	}
3236 	if (!count)
3237 		return 0;
3238 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3239 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3240 }
3241 
3242 /*
3243  * Compute the overhead and stash it in sbi->s_overhead
3244  */
3245 int ext4_calculate_overhead(struct super_block *sb)
3246 {
3247 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3248 	struct ext4_super_block *es = sbi->s_es;
3249 	struct inode *j_inode;
3250 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3251 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3252 	ext4_fsblk_t overhead = 0;
3253 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3254 
3255 	if (!buf)
3256 		return -ENOMEM;
3257 
3258 	/*
3259 	 * Compute the overhead (FS structures).  This is constant
3260 	 * for a given filesystem unless the number of block groups
3261 	 * changes so we cache the previous value until it does.
3262 	 */
3263 
3264 	/*
3265 	 * All of the blocks before first_data_block are overhead
3266 	 */
3267 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3268 
3269 	/*
3270 	 * Add the overhead found in each block group
3271 	 */
3272 	for (i = 0; i < ngroups; i++) {
3273 		int blks;
3274 
3275 		blks = count_overhead(sb, i, buf);
3276 		overhead += blks;
3277 		if (blks)
3278 			memset(buf, 0, PAGE_SIZE);
3279 		cond_resched();
3280 	}
3281 
3282 	/*
3283 	 * Add the internal journal blocks whether the journal has been
3284 	 * loaded or not
3285 	 */
3286 	if (sbi->s_journal && !sbi->journal_bdev)
3287 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3288 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3289 		j_inode = ext4_get_journal_inode(sb, j_inum);
3290 		if (j_inode) {
3291 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3292 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3293 			iput(j_inode);
3294 		} else {
3295 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3296 		}
3297 	}
3298 	sbi->s_overhead = overhead;
3299 	smp_wmb();
3300 	free_page((unsigned long) buf);
3301 	return 0;
3302 }
3303 
3304 static void ext4_set_resv_clusters(struct super_block *sb)
3305 {
3306 	ext4_fsblk_t resv_clusters;
3307 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3308 
3309 	/*
3310 	 * There's no need to reserve anything when we aren't using extents.
3311 	 * The space estimates are exact, there are no unwritten extents,
3312 	 * hole punching doesn't need new metadata... This is needed especially
3313 	 * to keep ext2/3 backward compatibility.
3314 	 */
3315 	if (!ext4_has_feature_extents(sb))
3316 		return;
3317 	/*
3318 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3319 	 * This should cover the situations where we can not afford to run
3320 	 * out of space like for example punch hole, or converting
3321 	 * unwritten extents in delalloc path. In most cases such
3322 	 * allocation would require 1, or 2 blocks, higher numbers are
3323 	 * very rare.
3324 	 */
3325 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3326 			 sbi->s_cluster_bits);
3327 
3328 	do_div(resv_clusters, 50);
3329 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3330 
3331 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3332 }
3333 
3334 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3335 {
3336 	char *orig_data = kstrdup(data, GFP_KERNEL);
3337 	struct buffer_head *bh;
3338 	struct ext4_super_block *es = NULL;
3339 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3340 	ext4_fsblk_t block;
3341 	ext4_fsblk_t sb_block = get_sb_block(&data);
3342 	ext4_fsblk_t logical_sb_block;
3343 	unsigned long offset = 0;
3344 	unsigned long journal_devnum = 0;
3345 	unsigned long def_mount_opts;
3346 	struct inode *root;
3347 	const char *descr;
3348 	int ret = -ENOMEM;
3349 	int blocksize, clustersize;
3350 	unsigned int db_count;
3351 	unsigned int i;
3352 	int needs_recovery, has_huge_files, has_bigalloc;
3353 	__u64 blocks_count;
3354 	int err = 0;
3355 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3356 	ext4_group_t first_not_zeroed;
3357 
3358 	if ((data && !orig_data) || !sbi)
3359 		goto out_free_base;
3360 
3361 	sbi->s_blockgroup_lock =
3362 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3363 	if (!sbi->s_blockgroup_lock)
3364 		goto out_free_base;
3365 
3366 	sb->s_fs_info = sbi;
3367 	sbi->s_sb = sb;
3368 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3369 	sbi->s_sb_block = sb_block;
3370 	if (sb->s_bdev->bd_part)
3371 		sbi->s_sectors_written_start =
3372 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3373 
3374 	/* Cleanup superblock name */
3375 	strreplace(sb->s_id, '/', '!');
3376 
3377 	/* -EINVAL is default */
3378 	ret = -EINVAL;
3379 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3380 	if (!blocksize) {
3381 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3382 		goto out_fail;
3383 	}
3384 
3385 	/*
3386 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3387 	 * block sizes.  We need to calculate the offset from buffer start.
3388 	 */
3389 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3390 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3391 		offset = do_div(logical_sb_block, blocksize);
3392 	} else {
3393 		logical_sb_block = sb_block;
3394 	}
3395 
3396 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3397 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3398 		goto out_fail;
3399 	}
3400 	/*
3401 	 * Note: s_es must be initialized as soon as possible because
3402 	 *       some ext4 macro-instructions depend on its value
3403 	 */
3404 	es = (struct ext4_super_block *) (bh->b_data + offset);
3405 	sbi->s_es = es;
3406 	sb->s_magic = le16_to_cpu(es->s_magic);
3407 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3408 		goto cantfind_ext4;
3409 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3410 
3411 	/* Warn if metadata_csum and gdt_csum are both set. */
3412 	if (ext4_has_feature_metadata_csum(sb) &&
3413 	    ext4_has_feature_gdt_csum(sb))
3414 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3415 			     "redundant flags; please run fsck.");
3416 
3417 	/* Check for a known checksum algorithm */
3418 	if (!ext4_verify_csum_type(sb, es)) {
3419 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3420 			 "unknown checksum algorithm.");
3421 		silent = 1;
3422 		goto cantfind_ext4;
3423 	}
3424 
3425 	/* Load the checksum driver */
3426 	if (ext4_has_feature_metadata_csum(sb)) {
3427 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3428 		if (IS_ERR(sbi->s_chksum_driver)) {
3429 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3430 			ret = PTR_ERR(sbi->s_chksum_driver);
3431 			sbi->s_chksum_driver = NULL;
3432 			goto failed_mount;
3433 		}
3434 	}
3435 
3436 	/* Check superblock checksum */
3437 	if (!ext4_superblock_csum_verify(sb, es)) {
3438 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3439 			 "invalid superblock checksum.  Run e2fsck?");
3440 		silent = 1;
3441 		ret = -EFSBADCRC;
3442 		goto cantfind_ext4;
3443 	}
3444 
3445 	/* Precompute checksum seed for all metadata */
3446 	if (ext4_has_feature_csum_seed(sb))
3447 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3448 	else if (ext4_has_metadata_csum(sb))
3449 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3450 					       sizeof(es->s_uuid));
3451 
3452 	/* Set defaults before we parse the mount options */
3453 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3454 	set_opt(sb, INIT_INODE_TABLE);
3455 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3456 		set_opt(sb, DEBUG);
3457 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3458 		set_opt(sb, GRPID);
3459 	if (def_mount_opts & EXT4_DEFM_UID16)
3460 		set_opt(sb, NO_UID32);
3461 	/* xattr user namespace & acls are now defaulted on */
3462 	set_opt(sb, XATTR_USER);
3463 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3464 	set_opt(sb, POSIX_ACL);
3465 #endif
3466 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3467 	if (ext4_has_metadata_csum(sb))
3468 		set_opt(sb, JOURNAL_CHECKSUM);
3469 
3470 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3471 		set_opt(sb, JOURNAL_DATA);
3472 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3473 		set_opt(sb, ORDERED_DATA);
3474 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3475 		set_opt(sb, WRITEBACK_DATA);
3476 
3477 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3478 		set_opt(sb, ERRORS_PANIC);
3479 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3480 		set_opt(sb, ERRORS_CONT);
3481 	else
3482 		set_opt(sb, ERRORS_RO);
3483 	/* block_validity enabled by default; disable with noblock_validity */
3484 	set_opt(sb, BLOCK_VALIDITY);
3485 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3486 		set_opt(sb, DISCARD);
3487 
3488 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3489 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3490 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3491 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3492 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3493 
3494 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3495 		set_opt(sb, BARRIER);
3496 
3497 	/*
3498 	 * enable delayed allocation by default
3499 	 * Use -o nodelalloc to turn it off
3500 	 */
3501 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3502 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3503 		set_opt(sb, DELALLOC);
3504 
3505 	/*
3506 	 * set default s_li_wait_mult for lazyinit, for the case there is
3507 	 * no mount option specified.
3508 	 */
3509 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3510 
3511 	if (sbi->s_es->s_mount_opts[0]) {
3512 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3513 					      sizeof(sbi->s_es->s_mount_opts),
3514 					      GFP_KERNEL);
3515 		if (!s_mount_opts)
3516 			goto failed_mount;
3517 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3518 				   &journal_ioprio, 0)) {
3519 			ext4_msg(sb, KERN_WARNING,
3520 				 "failed to parse options in superblock: %s",
3521 				 s_mount_opts);
3522 		}
3523 		kfree(s_mount_opts);
3524 	}
3525 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3526 	if (!parse_options((char *) data, sb, &journal_devnum,
3527 			   &journal_ioprio, 0))
3528 		goto failed_mount;
3529 
3530 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3531 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3532 			    "with data=journal disables delayed "
3533 			    "allocation and O_DIRECT support!\n");
3534 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3535 			ext4_msg(sb, KERN_ERR, "can't mount with "
3536 				 "both data=journal and delalloc");
3537 			goto failed_mount;
3538 		}
3539 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3540 			ext4_msg(sb, KERN_ERR, "can't mount with "
3541 				 "both data=journal and dioread_nolock");
3542 			goto failed_mount;
3543 		}
3544 		if (test_opt(sb, DAX)) {
3545 			ext4_msg(sb, KERN_ERR, "can't mount with "
3546 				 "both data=journal and dax");
3547 			goto failed_mount;
3548 		}
3549 		if (ext4_has_feature_encrypt(sb)) {
3550 			ext4_msg(sb, KERN_WARNING,
3551 				 "encrypted files will use data=ordered "
3552 				 "instead of data journaling mode");
3553 		}
3554 		if (test_opt(sb, DELALLOC))
3555 			clear_opt(sb, DELALLOC);
3556 	} else {
3557 		sb->s_iflags |= SB_I_CGROUPWB;
3558 	}
3559 
3560 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3561 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3562 
3563 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3564 	    (ext4_has_compat_features(sb) ||
3565 	     ext4_has_ro_compat_features(sb) ||
3566 	     ext4_has_incompat_features(sb)))
3567 		ext4_msg(sb, KERN_WARNING,
3568 		       "feature flags set on rev 0 fs, "
3569 		       "running e2fsck is recommended");
3570 
3571 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3572 		set_opt2(sb, HURD_COMPAT);
3573 		if (ext4_has_feature_64bit(sb)) {
3574 			ext4_msg(sb, KERN_ERR,
3575 				 "The Hurd can't support 64-bit file systems");
3576 			goto failed_mount;
3577 		}
3578 	}
3579 
3580 	if (IS_EXT2_SB(sb)) {
3581 		if (ext2_feature_set_ok(sb))
3582 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3583 				 "using the ext4 subsystem");
3584 		else {
3585 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3586 				 "to feature incompatibilities");
3587 			goto failed_mount;
3588 		}
3589 	}
3590 
3591 	if (IS_EXT3_SB(sb)) {
3592 		if (ext3_feature_set_ok(sb))
3593 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3594 				 "using the ext4 subsystem");
3595 		else {
3596 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3597 				 "to feature incompatibilities");
3598 			goto failed_mount;
3599 		}
3600 	}
3601 
3602 	/*
3603 	 * Check feature flags regardless of the revision level, since we
3604 	 * previously didn't change the revision level when setting the flags,
3605 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3606 	 */
3607 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3608 		goto failed_mount;
3609 
3610 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3611 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3612 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3613 		ext4_msg(sb, KERN_ERR,
3614 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3615 			 blocksize, le32_to_cpu(es->s_log_block_size));
3616 		goto failed_mount;
3617 	}
3618 	if (le32_to_cpu(es->s_log_block_size) >
3619 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3620 		ext4_msg(sb, KERN_ERR,
3621 			 "Invalid log block size: %u",
3622 			 le32_to_cpu(es->s_log_block_size));
3623 		goto failed_mount;
3624 	}
3625 
3626 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3627 		ext4_msg(sb, KERN_ERR,
3628 			 "Number of reserved GDT blocks insanely large: %d",
3629 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3630 		goto failed_mount;
3631 	}
3632 
3633 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3634 		err = bdev_dax_supported(sb, blocksize);
3635 		if (err)
3636 			goto failed_mount;
3637 	}
3638 
3639 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3640 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3641 			 es->s_encryption_level);
3642 		goto failed_mount;
3643 	}
3644 
3645 	if (sb->s_blocksize != blocksize) {
3646 		/* Validate the filesystem blocksize */
3647 		if (!sb_set_blocksize(sb, blocksize)) {
3648 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3649 					blocksize);
3650 			goto failed_mount;
3651 		}
3652 
3653 		brelse(bh);
3654 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3655 		offset = do_div(logical_sb_block, blocksize);
3656 		bh = sb_bread_unmovable(sb, logical_sb_block);
3657 		if (!bh) {
3658 			ext4_msg(sb, KERN_ERR,
3659 			       "Can't read superblock on 2nd try");
3660 			goto failed_mount;
3661 		}
3662 		es = (struct ext4_super_block *)(bh->b_data + offset);
3663 		sbi->s_es = es;
3664 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3665 			ext4_msg(sb, KERN_ERR,
3666 			       "Magic mismatch, very weird!");
3667 			goto failed_mount;
3668 		}
3669 	}
3670 
3671 	has_huge_files = ext4_has_feature_huge_file(sb);
3672 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3673 						      has_huge_files);
3674 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3675 
3676 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3677 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3678 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3679 	} else {
3680 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3681 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3682 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3683 		    (!is_power_of_2(sbi->s_inode_size)) ||
3684 		    (sbi->s_inode_size > blocksize)) {
3685 			ext4_msg(sb, KERN_ERR,
3686 			       "unsupported inode size: %d",
3687 			       sbi->s_inode_size);
3688 			goto failed_mount;
3689 		}
3690 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3691 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3692 	}
3693 
3694 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3695 	if (ext4_has_feature_64bit(sb)) {
3696 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3697 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3698 		    !is_power_of_2(sbi->s_desc_size)) {
3699 			ext4_msg(sb, KERN_ERR,
3700 			       "unsupported descriptor size %lu",
3701 			       sbi->s_desc_size);
3702 			goto failed_mount;
3703 		}
3704 	} else
3705 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3706 
3707 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3708 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3709 
3710 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3711 	if (sbi->s_inodes_per_block == 0)
3712 		goto cantfind_ext4;
3713 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3714 	    sbi->s_inodes_per_group > blocksize * 8) {
3715 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3716 			 sbi->s_blocks_per_group);
3717 		goto failed_mount;
3718 	}
3719 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3720 					sbi->s_inodes_per_block;
3721 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3722 	sbi->s_sbh = bh;
3723 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3724 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3725 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3726 
3727 	for (i = 0; i < 4; i++)
3728 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3729 	sbi->s_def_hash_version = es->s_def_hash_version;
3730 	if (ext4_has_feature_dir_index(sb)) {
3731 		i = le32_to_cpu(es->s_flags);
3732 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3733 			sbi->s_hash_unsigned = 3;
3734 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3735 #ifdef __CHAR_UNSIGNED__
3736 			if (!(sb->s_flags & MS_RDONLY))
3737 				es->s_flags |=
3738 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3739 			sbi->s_hash_unsigned = 3;
3740 #else
3741 			if (!(sb->s_flags & MS_RDONLY))
3742 				es->s_flags |=
3743 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3744 #endif
3745 		}
3746 	}
3747 
3748 	/* Handle clustersize */
3749 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3750 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3751 	if (has_bigalloc) {
3752 		if (clustersize < blocksize) {
3753 			ext4_msg(sb, KERN_ERR,
3754 				 "cluster size (%d) smaller than "
3755 				 "block size (%d)", clustersize, blocksize);
3756 			goto failed_mount;
3757 		}
3758 		if (le32_to_cpu(es->s_log_cluster_size) >
3759 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3760 			ext4_msg(sb, KERN_ERR,
3761 				 "Invalid log cluster size: %u",
3762 				 le32_to_cpu(es->s_log_cluster_size));
3763 			goto failed_mount;
3764 		}
3765 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3766 			le32_to_cpu(es->s_log_block_size);
3767 		sbi->s_clusters_per_group =
3768 			le32_to_cpu(es->s_clusters_per_group);
3769 		if (sbi->s_clusters_per_group > blocksize * 8) {
3770 			ext4_msg(sb, KERN_ERR,
3771 				 "#clusters per group too big: %lu",
3772 				 sbi->s_clusters_per_group);
3773 			goto failed_mount;
3774 		}
3775 		if (sbi->s_blocks_per_group !=
3776 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3777 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3778 				 "clusters per group (%lu) inconsistent",
3779 				 sbi->s_blocks_per_group,
3780 				 sbi->s_clusters_per_group);
3781 			goto failed_mount;
3782 		}
3783 	} else {
3784 		if (clustersize != blocksize) {
3785 			ext4_warning(sb, "fragment/cluster size (%d) != "
3786 				     "block size (%d)", clustersize,
3787 				     blocksize);
3788 			clustersize = blocksize;
3789 		}
3790 		if (sbi->s_blocks_per_group > blocksize * 8) {
3791 			ext4_msg(sb, KERN_ERR,
3792 				 "#blocks per group too big: %lu",
3793 				 sbi->s_blocks_per_group);
3794 			goto failed_mount;
3795 		}
3796 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3797 		sbi->s_cluster_bits = 0;
3798 	}
3799 	sbi->s_cluster_ratio = clustersize / blocksize;
3800 
3801 	/* Do we have standard group size of clustersize * 8 blocks ? */
3802 	if (sbi->s_blocks_per_group == clustersize << 3)
3803 		set_opt2(sb, STD_GROUP_SIZE);
3804 
3805 	/*
3806 	 * Test whether we have more sectors than will fit in sector_t,
3807 	 * and whether the max offset is addressable by the page cache.
3808 	 */
3809 	err = generic_check_addressable(sb->s_blocksize_bits,
3810 					ext4_blocks_count(es));
3811 	if (err) {
3812 		ext4_msg(sb, KERN_ERR, "filesystem"
3813 			 " too large to mount safely on this system");
3814 		if (sizeof(sector_t) < 8)
3815 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3816 		goto failed_mount;
3817 	}
3818 
3819 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3820 		goto cantfind_ext4;
3821 
3822 	/* check blocks count against device size */
3823 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3824 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3825 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3826 		       "exceeds size of device (%llu blocks)",
3827 		       ext4_blocks_count(es), blocks_count);
3828 		goto failed_mount;
3829 	}
3830 
3831 	/*
3832 	 * It makes no sense for the first data block to be beyond the end
3833 	 * of the filesystem.
3834 	 */
3835 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3836 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3837 			 "block %u is beyond end of filesystem (%llu)",
3838 			 le32_to_cpu(es->s_first_data_block),
3839 			 ext4_blocks_count(es));
3840 		goto failed_mount;
3841 	}
3842 	blocks_count = (ext4_blocks_count(es) -
3843 			le32_to_cpu(es->s_first_data_block) +
3844 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3845 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3846 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3847 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3848 		       "(block count %llu, first data block %u, "
3849 		       "blocks per group %lu)", sbi->s_groups_count,
3850 		       ext4_blocks_count(es),
3851 		       le32_to_cpu(es->s_first_data_block),
3852 		       EXT4_BLOCKS_PER_GROUP(sb));
3853 		goto failed_mount;
3854 	}
3855 	sbi->s_groups_count = blocks_count;
3856 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3857 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3858 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3859 		   EXT4_DESC_PER_BLOCK(sb);
3860 	if (ext4_has_feature_meta_bg(sb)) {
3861 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3862 			ext4_msg(sb, KERN_WARNING,
3863 				 "first meta block group too large: %u "
3864 				 "(group descriptor block count %u)",
3865 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3866 			goto failed_mount;
3867 		}
3868 	}
3869 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3870 					  sizeof(struct buffer_head *),
3871 					  GFP_KERNEL);
3872 	if (sbi->s_group_desc == NULL) {
3873 		ext4_msg(sb, KERN_ERR, "not enough memory");
3874 		ret = -ENOMEM;
3875 		goto failed_mount;
3876 	}
3877 
3878 	bgl_lock_init(sbi->s_blockgroup_lock);
3879 
3880 	for (i = 0; i < db_count; i++) {
3881 		block = descriptor_loc(sb, logical_sb_block, i);
3882 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3883 		if (!sbi->s_group_desc[i]) {
3884 			ext4_msg(sb, KERN_ERR,
3885 			       "can't read group descriptor %d", i);
3886 			db_count = i;
3887 			goto failed_mount2;
3888 		}
3889 	}
3890 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3891 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3892 		ret = -EFSCORRUPTED;
3893 		goto failed_mount2;
3894 	}
3895 
3896 	sbi->s_gdb_count = db_count;
3897 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3898 	spin_lock_init(&sbi->s_next_gen_lock);
3899 
3900 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3901 		(unsigned long) sb);
3902 
3903 	/* Register extent status tree shrinker */
3904 	if (ext4_es_register_shrinker(sbi))
3905 		goto failed_mount3;
3906 
3907 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3908 	sbi->s_extent_max_zeroout_kb = 32;
3909 
3910 	/*
3911 	 * set up enough so that it can read an inode
3912 	 */
3913 	sb->s_op = &ext4_sops;
3914 	sb->s_export_op = &ext4_export_ops;
3915 	sb->s_xattr = ext4_xattr_handlers;
3916 	sb->s_cop = &ext4_cryptops;
3917 #ifdef CONFIG_QUOTA
3918 	sb->dq_op = &ext4_quota_operations;
3919 	if (ext4_has_feature_quota(sb))
3920 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3921 	else
3922 		sb->s_qcop = &ext4_qctl_operations;
3923 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3924 #endif
3925 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3926 
3927 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3928 	mutex_init(&sbi->s_orphan_lock);
3929 
3930 	sb->s_root = NULL;
3931 
3932 	needs_recovery = (es->s_last_orphan != 0 ||
3933 			  ext4_has_feature_journal_needs_recovery(sb));
3934 
3935 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3936 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3937 			goto failed_mount3a;
3938 
3939 	/*
3940 	 * The first inode we look at is the journal inode.  Don't try
3941 	 * root first: it may be modified in the journal!
3942 	 */
3943 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3944 		err = ext4_load_journal(sb, es, journal_devnum);
3945 		if (err)
3946 			goto failed_mount3a;
3947 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3948 		   ext4_has_feature_journal_needs_recovery(sb)) {
3949 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3950 		       "suppressed and not mounted read-only");
3951 		goto failed_mount_wq;
3952 	} else {
3953 		/* Nojournal mode, all journal mount options are illegal */
3954 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3955 			ext4_msg(sb, KERN_ERR, "can't mount with "
3956 				 "journal_checksum, fs mounted w/o journal");
3957 			goto failed_mount_wq;
3958 		}
3959 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3960 			ext4_msg(sb, KERN_ERR, "can't mount with "
3961 				 "journal_async_commit, fs mounted w/o journal");
3962 			goto failed_mount_wq;
3963 		}
3964 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3965 			ext4_msg(sb, KERN_ERR, "can't mount with "
3966 				 "commit=%lu, fs mounted w/o journal",
3967 				 sbi->s_commit_interval / HZ);
3968 			goto failed_mount_wq;
3969 		}
3970 		if (EXT4_MOUNT_DATA_FLAGS &
3971 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3972 			ext4_msg(sb, KERN_ERR, "can't mount with "
3973 				 "data=, fs mounted w/o journal");
3974 			goto failed_mount_wq;
3975 		}
3976 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3977 		clear_opt(sb, JOURNAL_CHECKSUM);
3978 		clear_opt(sb, DATA_FLAGS);
3979 		sbi->s_journal = NULL;
3980 		needs_recovery = 0;
3981 		goto no_journal;
3982 	}
3983 
3984 	if (ext4_has_feature_64bit(sb) &&
3985 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3986 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3987 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3988 		goto failed_mount_wq;
3989 	}
3990 
3991 	if (!set_journal_csum_feature_set(sb)) {
3992 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3993 			 "feature set");
3994 		goto failed_mount_wq;
3995 	}
3996 
3997 	/* We have now updated the journal if required, so we can
3998 	 * validate the data journaling mode. */
3999 	switch (test_opt(sb, DATA_FLAGS)) {
4000 	case 0:
4001 		/* No mode set, assume a default based on the journal
4002 		 * capabilities: ORDERED_DATA if the journal can
4003 		 * cope, else JOURNAL_DATA
4004 		 */
4005 		if (jbd2_journal_check_available_features
4006 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4007 			set_opt(sb, ORDERED_DATA);
4008 		else
4009 			set_opt(sb, JOURNAL_DATA);
4010 		break;
4011 
4012 	case EXT4_MOUNT_ORDERED_DATA:
4013 	case EXT4_MOUNT_WRITEBACK_DATA:
4014 		if (!jbd2_journal_check_available_features
4015 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4016 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4017 			       "requested data journaling mode");
4018 			goto failed_mount_wq;
4019 		}
4020 	default:
4021 		break;
4022 	}
4023 
4024 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4025 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4026 		ext4_msg(sb, KERN_ERR, "can't mount with "
4027 			"journal_async_commit in data=ordered mode");
4028 		goto failed_mount_wq;
4029 	}
4030 
4031 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4032 
4033 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4034 
4035 no_journal:
4036 	sbi->s_mb_cache = ext4_xattr_create_cache();
4037 	if (!sbi->s_mb_cache) {
4038 		ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4039 		goto failed_mount_wq;
4040 	}
4041 
4042 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4043 	    (blocksize != PAGE_SIZE)) {
4044 		ext4_msg(sb, KERN_ERR,
4045 			 "Unsupported blocksize for fs encryption");
4046 		goto failed_mount_wq;
4047 	}
4048 
4049 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4050 	    !ext4_has_feature_encrypt(sb)) {
4051 		ext4_set_feature_encrypt(sb);
4052 		ext4_commit_super(sb, 1);
4053 	}
4054 
4055 	/*
4056 	 * Get the # of file system overhead blocks from the
4057 	 * superblock if present.
4058 	 */
4059 	if (es->s_overhead_clusters)
4060 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4061 	else {
4062 		err = ext4_calculate_overhead(sb);
4063 		if (err)
4064 			goto failed_mount_wq;
4065 	}
4066 
4067 	/*
4068 	 * The maximum number of concurrent works can be high and
4069 	 * concurrency isn't really necessary.  Limit it to 1.
4070 	 */
4071 	EXT4_SB(sb)->rsv_conversion_wq =
4072 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4073 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4074 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4075 		ret = -ENOMEM;
4076 		goto failed_mount4;
4077 	}
4078 
4079 	/*
4080 	 * The jbd2_journal_load will have done any necessary log recovery,
4081 	 * so we can safely mount the rest of the filesystem now.
4082 	 */
4083 
4084 	root = ext4_iget(sb, EXT4_ROOT_INO);
4085 	if (IS_ERR(root)) {
4086 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4087 		ret = PTR_ERR(root);
4088 		root = NULL;
4089 		goto failed_mount4;
4090 	}
4091 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4092 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4093 		iput(root);
4094 		goto failed_mount4;
4095 	}
4096 	sb->s_root = d_make_root(root);
4097 	if (!sb->s_root) {
4098 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4099 		ret = -ENOMEM;
4100 		goto failed_mount4;
4101 	}
4102 
4103 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4104 		sb->s_flags |= MS_RDONLY;
4105 
4106 	/* determine the minimum size of new large inodes, if present */
4107 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4108 	    sbi->s_want_extra_isize == 0) {
4109 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4110 						     EXT4_GOOD_OLD_INODE_SIZE;
4111 		if (ext4_has_feature_extra_isize(sb)) {
4112 			if (sbi->s_want_extra_isize <
4113 			    le16_to_cpu(es->s_want_extra_isize))
4114 				sbi->s_want_extra_isize =
4115 					le16_to_cpu(es->s_want_extra_isize);
4116 			if (sbi->s_want_extra_isize <
4117 			    le16_to_cpu(es->s_min_extra_isize))
4118 				sbi->s_want_extra_isize =
4119 					le16_to_cpu(es->s_min_extra_isize);
4120 		}
4121 	}
4122 	/* Check if enough inode space is available */
4123 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4124 							sbi->s_inode_size) {
4125 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4126 						       EXT4_GOOD_OLD_INODE_SIZE;
4127 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4128 			 "available");
4129 	}
4130 
4131 	ext4_set_resv_clusters(sb);
4132 
4133 	err = ext4_setup_system_zone(sb);
4134 	if (err) {
4135 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4136 			 "zone (%d)", err);
4137 		goto failed_mount4a;
4138 	}
4139 
4140 	ext4_ext_init(sb);
4141 	err = ext4_mb_init(sb);
4142 	if (err) {
4143 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4144 			 err);
4145 		goto failed_mount5;
4146 	}
4147 
4148 	block = ext4_count_free_clusters(sb);
4149 	ext4_free_blocks_count_set(sbi->s_es,
4150 				   EXT4_C2B(sbi, block));
4151 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4152 				  GFP_KERNEL);
4153 	if (!err) {
4154 		unsigned long freei = ext4_count_free_inodes(sb);
4155 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4156 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4157 					  GFP_KERNEL);
4158 	}
4159 	if (!err)
4160 		err = percpu_counter_init(&sbi->s_dirs_counter,
4161 					  ext4_count_dirs(sb), GFP_KERNEL);
4162 	if (!err)
4163 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4164 					  GFP_KERNEL);
4165 	if (!err)
4166 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4167 
4168 	if (err) {
4169 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4170 		goto failed_mount6;
4171 	}
4172 
4173 	if (ext4_has_feature_flex_bg(sb))
4174 		if (!ext4_fill_flex_info(sb)) {
4175 			ext4_msg(sb, KERN_ERR,
4176 			       "unable to initialize "
4177 			       "flex_bg meta info!");
4178 			goto failed_mount6;
4179 		}
4180 
4181 	err = ext4_register_li_request(sb, first_not_zeroed);
4182 	if (err)
4183 		goto failed_mount6;
4184 
4185 	err = ext4_register_sysfs(sb);
4186 	if (err)
4187 		goto failed_mount7;
4188 
4189 #ifdef CONFIG_QUOTA
4190 	/* Enable quota usage during mount. */
4191 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4192 		err = ext4_enable_quotas(sb);
4193 		if (err)
4194 			goto failed_mount8;
4195 	}
4196 #endif  /* CONFIG_QUOTA */
4197 
4198 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4199 	ext4_orphan_cleanup(sb, es);
4200 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4201 	if (needs_recovery) {
4202 		ext4_msg(sb, KERN_INFO, "recovery complete");
4203 		ext4_mark_recovery_complete(sb, es);
4204 	}
4205 	if (EXT4_SB(sb)->s_journal) {
4206 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4207 			descr = " journalled data mode";
4208 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4209 			descr = " ordered data mode";
4210 		else
4211 			descr = " writeback data mode";
4212 	} else
4213 		descr = "out journal";
4214 
4215 	if (test_opt(sb, DISCARD)) {
4216 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4217 		if (!blk_queue_discard(q))
4218 			ext4_msg(sb, KERN_WARNING,
4219 				 "mounting with \"discard\" option, but "
4220 				 "the device does not support discard");
4221 	}
4222 
4223 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4224 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4225 			 "Opts: %.*s%s%s", descr,
4226 			 (int) sizeof(sbi->s_es->s_mount_opts),
4227 			 sbi->s_es->s_mount_opts,
4228 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4229 
4230 	if (es->s_error_count)
4231 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4232 
4233 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4234 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4235 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4236 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4237 
4238 	kfree(orig_data);
4239 	return 0;
4240 
4241 cantfind_ext4:
4242 	if (!silent)
4243 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4244 	goto failed_mount;
4245 
4246 #ifdef CONFIG_QUOTA
4247 failed_mount8:
4248 	ext4_unregister_sysfs(sb);
4249 #endif
4250 failed_mount7:
4251 	ext4_unregister_li_request(sb);
4252 failed_mount6:
4253 	ext4_mb_release(sb);
4254 	if (sbi->s_flex_groups)
4255 		kvfree(sbi->s_flex_groups);
4256 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4257 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4258 	percpu_counter_destroy(&sbi->s_dirs_counter);
4259 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4260 failed_mount5:
4261 	ext4_ext_release(sb);
4262 	ext4_release_system_zone(sb);
4263 failed_mount4a:
4264 	dput(sb->s_root);
4265 	sb->s_root = NULL;
4266 failed_mount4:
4267 	ext4_msg(sb, KERN_ERR, "mount failed");
4268 	if (EXT4_SB(sb)->rsv_conversion_wq)
4269 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4270 failed_mount_wq:
4271 	if (sbi->s_mb_cache) {
4272 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
4273 		sbi->s_mb_cache = NULL;
4274 	}
4275 	if (sbi->s_journal) {
4276 		jbd2_journal_destroy(sbi->s_journal);
4277 		sbi->s_journal = NULL;
4278 	}
4279 failed_mount3a:
4280 	ext4_es_unregister_shrinker(sbi);
4281 failed_mount3:
4282 	del_timer_sync(&sbi->s_err_report);
4283 	if (sbi->s_mmp_tsk)
4284 		kthread_stop(sbi->s_mmp_tsk);
4285 failed_mount2:
4286 	for (i = 0; i < db_count; i++)
4287 		brelse(sbi->s_group_desc[i]);
4288 	kvfree(sbi->s_group_desc);
4289 failed_mount:
4290 	if (sbi->s_chksum_driver)
4291 		crypto_free_shash(sbi->s_chksum_driver);
4292 #ifdef CONFIG_QUOTA
4293 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4294 		kfree(sbi->s_qf_names[i]);
4295 #endif
4296 	ext4_blkdev_remove(sbi);
4297 	brelse(bh);
4298 out_fail:
4299 	sb->s_fs_info = NULL;
4300 	kfree(sbi->s_blockgroup_lock);
4301 out_free_base:
4302 	kfree(sbi);
4303 	kfree(orig_data);
4304 	return err ? err : ret;
4305 }
4306 
4307 /*
4308  * Setup any per-fs journal parameters now.  We'll do this both on
4309  * initial mount, once the journal has been initialised but before we've
4310  * done any recovery; and again on any subsequent remount.
4311  */
4312 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4313 {
4314 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4315 
4316 	journal->j_commit_interval = sbi->s_commit_interval;
4317 	journal->j_min_batch_time = sbi->s_min_batch_time;
4318 	journal->j_max_batch_time = sbi->s_max_batch_time;
4319 
4320 	write_lock(&journal->j_state_lock);
4321 	if (test_opt(sb, BARRIER))
4322 		journal->j_flags |= JBD2_BARRIER;
4323 	else
4324 		journal->j_flags &= ~JBD2_BARRIER;
4325 	if (test_opt(sb, DATA_ERR_ABORT))
4326 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4327 	else
4328 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4329 	write_unlock(&journal->j_state_lock);
4330 }
4331 
4332 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4333 					     unsigned int journal_inum)
4334 {
4335 	struct inode *journal_inode;
4336 
4337 	/*
4338 	 * Test for the existence of a valid inode on disk.  Bad things
4339 	 * happen if we iget() an unused inode, as the subsequent iput()
4340 	 * will try to delete it.
4341 	 */
4342 	journal_inode = ext4_iget(sb, journal_inum);
4343 	if (IS_ERR(journal_inode)) {
4344 		ext4_msg(sb, KERN_ERR, "no journal found");
4345 		return NULL;
4346 	}
4347 	if (!journal_inode->i_nlink) {
4348 		make_bad_inode(journal_inode);
4349 		iput(journal_inode);
4350 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4351 		return NULL;
4352 	}
4353 
4354 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4355 		  journal_inode, journal_inode->i_size);
4356 	if (!S_ISREG(journal_inode->i_mode)) {
4357 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4358 		iput(journal_inode);
4359 		return NULL;
4360 	}
4361 	return journal_inode;
4362 }
4363 
4364 static journal_t *ext4_get_journal(struct super_block *sb,
4365 				   unsigned int journal_inum)
4366 {
4367 	struct inode *journal_inode;
4368 	journal_t *journal;
4369 
4370 	BUG_ON(!ext4_has_feature_journal(sb));
4371 
4372 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4373 	if (!journal_inode)
4374 		return NULL;
4375 
4376 	journal = jbd2_journal_init_inode(journal_inode);
4377 	if (!journal) {
4378 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4379 		iput(journal_inode);
4380 		return NULL;
4381 	}
4382 	journal->j_private = sb;
4383 	ext4_init_journal_params(sb, journal);
4384 	return journal;
4385 }
4386 
4387 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4388 				       dev_t j_dev)
4389 {
4390 	struct buffer_head *bh;
4391 	journal_t *journal;
4392 	ext4_fsblk_t start;
4393 	ext4_fsblk_t len;
4394 	int hblock, blocksize;
4395 	ext4_fsblk_t sb_block;
4396 	unsigned long offset;
4397 	struct ext4_super_block *es;
4398 	struct block_device *bdev;
4399 
4400 	BUG_ON(!ext4_has_feature_journal(sb));
4401 
4402 	bdev = ext4_blkdev_get(j_dev, sb);
4403 	if (bdev == NULL)
4404 		return NULL;
4405 
4406 	blocksize = sb->s_blocksize;
4407 	hblock = bdev_logical_block_size(bdev);
4408 	if (blocksize < hblock) {
4409 		ext4_msg(sb, KERN_ERR,
4410 			"blocksize too small for journal device");
4411 		goto out_bdev;
4412 	}
4413 
4414 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4415 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4416 	set_blocksize(bdev, blocksize);
4417 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4418 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4419 		       "external journal");
4420 		goto out_bdev;
4421 	}
4422 
4423 	es = (struct ext4_super_block *) (bh->b_data + offset);
4424 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4425 	    !(le32_to_cpu(es->s_feature_incompat) &
4426 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4427 		ext4_msg(sb, KERN_ERR, "external journal has "
4428 					"bad superblock");
4429 		brelse(bh);
4430 		goto out_bdev;
4431 	}
4432 
4433 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4434 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4435 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4436 		ext4_msg(sb, KERN_ERR, "external journal has "
4437 				       "corrupt superblock");
4438 		brelse(bh);
4439 		goto out_bdev;
4440 	}
4441 
4442 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4443 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4444 		brelse(bh);
4445 		goto out_bdev;
4446 	}
4447 
4448 	len = ext4_blocks_count(es);
4449 	start = sb_block + 1;
4450 	brelse(bh);	/* we're done with the superblock */
4451 
4452 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4453 					start, len, blocksize);
4454 	if (!journal) {
4455 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4456 		goto out_bdev;
4457 	}
4458 	journal->j_private = sb;
4459 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4460 	wait_on_buffer(journal->j_sb_buffer);
4461 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4462 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4463 		goto out_journal;
4464 	}
4465 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4466 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4467 					"user (unsupported) - %d",
4468 			be32_to_cpu(journal->j_superblock->s_nr_users));
4469 		goto out_journal;
4470 	}
4471 	EXT4_SB(sb)->journal_bdev = bdev;
4472 	ext4_init_journal_params(sb, journal);
4473 	return journal;
4474 
4475 out_journal:
4476 	jbd2_journal_destroy(journal);
4477 out_bdev:
4478 	ext4_blkdev_put(bdev);
4479 	return NULL;
4480 }
4481 
4482 static int ext4_load_journal(struct super_block *sb,
4483 			     struct ext4_super_block *es,
4484 			     unsigned long journal_devnum)
4485 {
4486 	journal_t *journal;
4487 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4488 	dev_t journal_dev;
4489 	int err = 0;
4490 	int really_read_only;
4491 
4492 	BUG_ON(!ext4_has_feature_journal(sb));
4493 
4494 	if (journal_devnum &&
4495 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4496 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4497 			"numbers have changed");
4498 		journal_dev = new_decode_dev(journal_devnum);
4499 	} else
4500 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4501 
4502 	really_read_only = bdev_read_only(sb->s_bdev);
4503 
4504 	/*
4505 	 * Are we loading a blank journal or performing recovery after a
4506 	 * crash?  For recovery, we need to check in advance whether we
4507 	 * can get read-write access to the device.
4508 	 */
4509 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4510 		if (sb->s_flags & MS_RDONLY) {
4511 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4512 					"required on readonly filesystem");
4513 			if (really_read_only) {
4514 				ext4_msg(sb, KERN_ERR, "write access "
4515 					"unavailable, cannot proceed");
4516 				return -EROFS;
4517 			}
4518 			ext4_msg(sb, KERN_INFO, "write access will "
4519 			       "be enabled during recovery");
4520 		}
4521 	}
4522 
4523 	if (journal_inum && journal_dev) {
4524 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4525 		       "and inode journals!");
4526 		return -EINVAL;
4527 	}
4528 
4529 	if (journal_inum) {
4530 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4531 			return -EINVAL;
4532 	} else {
4533 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4534 			return -EINVAL;
4535 	}
4536 
4537 	if (!(journal->j_flags & JBD2_BARRIER))
4538 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4539 
4540 	if (!ext4_has_feature_journal_needs_recovery(sb))
4541 		err = jbd2_journal_wipe(journal, !really_read_only);
4542 	if (!err) {
4543 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4544 		if (save)
4545 			memcpy(save, ((char *) es) +
4546 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4547 		err = jbd2_journal_load(journal);
4548 		if (save)
4549 			memcpy(((char *) es) + EXT4_S_ERR_START,
4550 			       save, EXT4_S_ERR_LEN);
4551 		kfree(save);
4552 	}
4553 
4554 	if (err) {
4555 		ext4_msg(sb, KERN_ERR, "error loading journal");
4556 		jbd2_journal_destroy(journal);
4557 		return err;
4558 	}
4559 
4560 	EXT4_SB(sb)->s_journal = journal;
4561 	ext4_clear_journal_err(sb, es);
4562 
4563 	if (!really_read_only && journal_devnum &&
4564 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4565 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4566 
4567 		/* Make sure we flush the recovery flag to disk. */
4568 		ext4_commit_super(sb, 1);
4569 	}
4570 
4571 	return 0;
4572 }
4573 
4574 static int ext4_commit_super(struct super_block *sb, int sync)
4575 {
4576 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4577 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4578 	int error = 0;
4579 
4580 	if (!sbh || block_device_ejected(sb))
4581 		return error;
4582 	/*
4583 	 * If the file system is mounted read-only, don't update the
4584 	 * superblock write time.  This avoids updating the superblock
4585 	 * write time when we are mounting the root file system
4586 	 * read/only but we need to replay the journal; at that point,
4587 	 * for people who are east of GMT and who make their clock
4588 	 * tick in localtime for Windows bug-for-bug compatibility,
4589 	 * the clock is set in the future, and this will cause e2fsck
4590 	 * to complain and force a full file system check.
4591 	 */
4592 	if (!(sb->s_flags & MS_RDONLY))
4593 		es->s_wtime = cpu_to_le32(get_seconds());
4594 	if (sb->s_bdev->bd_part)
4595 		es->s_kbytes_written =
4596 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4597 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4598 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4599 	else
4600 		es->s_kbytes_written =
4601 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4602 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4603 		ext4_free_blocks_count_set(es,
4604 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4605 				&EXT4_SB(sb)->s_freeclusters_counter)));
4606 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4607 		es->s_free_inodes_count =
4608 			cpu_to_le32(percpu_counter_sum_positive(
4609 				&EXT4_SB(sb)->s_freeinodes_counter));
4610 	BUFFER_TRACE(sbh, "marking dirty");
4611 	ext4_superblock_csum_set(sb);
4612 	if (sync)
4613 		lock_buffer(sbh);
4614 	if (buffer_write_io_error(sbh)) {
4615 		/*
4616 		 * Oh, dear.  A previous attempt to write the
4617 		 * superblock failed.  This could happen because the
4618 		 * USB device was yanked out.  Or it could happen to
4619 		 * be a transient write error and maybe the block will
4620 		 * be remapped.  Nothing we can do but to retry the
4621 		 * write and hope for the best.
4622 		 */
4623 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4624 		       "superblock detected");
4625 		clear_buffer_write_io_error(sbh);
4626 		set_buffer_uptodate(sbh);
4627 	}
4628 	mark_buffer_dirty(sbh);
4629 	if (sync) {
4630 		unlock_buffer(sbh);
4631 		error = __sync_dirty_buffer(sbh,
4632 			test_opt(sb, BARRIER) ? REQ_FUA : REQ_SYNC);
4633 		if (error)
4634 			return error;
4635 
4636 		error = buffer_write_io_error(sbh);
4637 		if (error) {
4638 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4639 			       "superblock");
4640 			clear_buffer_write_io_error(sbh);
4641 			set_buffer_uptodate(sbh);
4642 		}
4643 	}
4644 	return error;
4645 }
4646 
4647 /*
4648  * Have we just finished recovery?  If so, and if we are mounting (or
4649  * remounting) the filesystem readonly, then we will end up with a
4650  * consistent fs on disk.  Record that fact.
4651  */
4652 static void ext4_mark_recovery_complete(struct super_block *sb,
4653 					struct ext4_super_block *es)
4654 {
4655 	journal_t *journal = EXT4_SB(sb)->s_journal;
4656 
4657 	if (!ext4_has_feature_journal(sb)) {
4658 		BUG_ON(journal != NULL);
4659 		return;
4660 	}
4661 	jbd2_journal_lock_updates(journal);
4662 	if (jbd2_journal_flush(journal) < 0)
4663 		goto out;
4664 
4665 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4666 	    sb->s_flags & MS_RDONLY) {
4667 		ext4_clear_feature_journal_needs_recovery(sb);
4668 		ext4_commit_super(sb, 1);
4669 	}
4670 
4671 out:
4672 	jbd2_journal_unlock_updates(journal);
4673 }
4674 
4675 /*
4676  * If we are mounting (or read-write remounting) a filesystem whose journal
4677  * has recorded an error from a previous lifetime, move that error to the
4678  * main filesystem now.
4679  */
4680 static void ext4_clear_journal_err(struct super_block *sb,
4681 				   struct ext4_super_block *es)
4682 {
4683 	journal_t *journal;
4684 	int j_errno;
4685 	const char *errstr;
4686 
4687 	BUG_ON(!ext4_has_feature_journal(sb));
4688 
4689 	journal = EXT4_SB(sb)->s_journal;
4690 
4691 	/*
4692 	 * Now check for any error status which may have been recorded in the
4693 	 * journal by a prior ext4_error() or ext4_abort()
4694 	 */
4695 
4696 	j_errno = jbd2_journal_errno(journal);
4697 	if (j_errno) {
4698 		char nbuf[16];
4699 
4700 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4701 		ext4_warning(sb, "Filesystem error recorded "
4702 			     "from previous mount: %s", errstr);
4703 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4704 
4705 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4706 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4707 		ext4_commit_super(sb, 1);
4708 
4709 		jbd2_journal_clear_err(journal);
4710 		jbd2_journal_update_sb_errno(journal);
4711 	}
4712 }
4713 
4714 /*
4715  * Force the running and committing transactions to commit,
4716  * and wait on the commit.
4717  */
4718 int ext4_force_commit(struct super_block *sb)
4719 {
4720 	journal_t *journal;
4721 
4722 	if (sb->s_flags & MS_RDONLY)
4723 		return 0;
4724 
4725 	journal = EXT4_SB(sb)->s_journal;
4726 	return ext4_journal_force_commit(journal);
4727 }
4728 
4729 static int ext4_sync_fs(struct super_block *sb, int wait)
4730 {
4731 	int ret = 0;
4732 	tid_t target;
4733 	bool needs_barrier = false;
4734 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4735 
4736 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4737 		return 0;
4738 
4739 	trace_ext4_sync_fs(sb, wait);
4740 	flush_workqueue(sbi->rsv_conversion_wq);
4741 	/*
4742 	 * Writeback quota in non-journalled quota case - journalled quota has
4743 	 * no dirty dquots
4744 	 */
4745 	dquot_writeback_dquots(sb, -1);
4746 	/*
4747 	 * Data writeback is possible w/o journal transaction, so barrier must
4748 	 * being sent at the end of the function. But we can skip it if
4749 	 * transaction_commit will do it for us.
4750 	 */
4751 	if (sbi->s_journal) {
4752 		target = jbd2_get_latest_transaction(sbi->s_journal);
4753 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4754 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4755 			needs_barrier = true;
4756 
4757 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4758 			if (wait)
4759 				ret = jbd2_log_wait_commit(sbi->s_journal,
4760 							   target);
4761 		}
4762 	} else if (wait && test_opt(sb, BARRIER))
4763 		needs_barrier = true;
4764 	if (needs_barrier) {
4765 		int err;
4766 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4767 		if (!ret)
4768 			ret = err;
4769 	}
4770 
4771 	return ret;
4772 }
4773 
4774 /*
4775  * LVM calls this function before a (read-only) snapshot is created.  This
4776  * gives us a chance to flush the journal completely and mark the fs clean.
4777  *
4778  * Note that only this function cannot bring a filesystem to be in a clean
4779  * state independently. It relies on upper layer to stop all data & metadata
4780  * modifications.
4781  */
4782 static int ext4_freeze(struct super_block *sb)
4783 {
4784 	int error = 0;
4785 	journal_t *journal;
4786 
4787 	if (sb->s_flags & MS_RDONLY)
4788 		return 0;
4789 
4790 	journal = EXT4_SB(sb)->s_journal;
4791 
4792 	if (journal) {
4793 		/* Now we set up the journal barrier. */
4794 		jbd2_journal_lock_updates(journal);
4795 
4796 		/*
4797 		 * Don't clear the needs_recovery flag if we failed to
4798 		 * flush the journal.
4799 		 */
4800 		error = jbd2_journal_flush(journal);
4801 		if (error < 0)
4802 			goto out;
4803 
4804 		/* Journal blocked and flushed, clear needs_recovery flag. */
4805 		ext4_clear_feature_journal_needs_recovery(sb);
4806 	}
4807 
4808 	error = ext4_commit_super(sb, 1);
4809 out:
4810 	if (journal)
4811 		/* we rely on upper layer to stop further updates */
4812 		jbd2_journal_unlock_updates(journal);
4813 	return error;
4814 }
4815 
4816 /*
4817  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4818  * flag here, even though the filesystem is not technically dirty yet.
4819  */
4820 static int ext4_unfreeze(struct super_block *sb)
4821 {
4822 	if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4823 		return 0;
4824 
4825 	if (EXT4_SB(sb)->s_journal) {
4826 		/* Reset the needs_recovery flag before the fs is unlocked. */
4827 		ext4_set_feature_journal_needs_recovery(sb);
4828 	}
4829 
4830 	ext4_commit_super(sb, 1);
4831 	return 0;
4832 }
4833 
4834 /*
4835  * Structure to save mount options for ext4_remount's benefit
4836  */
4837 struct ext4_mount_options {
4838 	unsigned long s_mount_opt;
4839 	unsigned long s_mount_opt2;
4840 	kuid_t s_resuid;
4841 	kgid_t s_resgid;
4842 	unsigned long s_commit_interval;
4843 	u32 s_min_batch_time, s_max_batch_time;
4844 #ifdef CONFIG_QUOTA
4845 	int s_jquota_fmt;
4846 	char *s_qf_names[EXT4_MAXQUOTAS];
4847 #endif
4848 };
4849 
4850 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4851 {
4852 	struct ext4_super_block *es;
4853 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4854 	unsigned long old_sb_flags;
4855 	struct ext4_mount_options old_opts;
4856 	int enable_quota = 0;
4857 	ext4_group_t g;
4858 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4859 	int err = 0;
4860 #ifdef CONFIG_QUOTA
4861 	int i, j;
4862 #endif
4863 	char *orig_data = kstrdup(data, GFP_KERNEL);
4864 
4865 	/* Store the original options */
4866 	old_sb_flags = sb->s_flags;
4867 	old_opts.s_mount_opt = sbi->s_mount_opt;
4868 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4869 	old_opts.s_resuid = sbi->s_resuid;
4870 	old_opts.s_resgid = sbi->s_resgid;
4871 	old_opts.s_commit_interval = sbi->s_commit_interval;
4872 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4873 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4874 #ifdef CONFIG_QUOTA
4875 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4876 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4877 		if (sbi->s_qf_names[i]) {
4878 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4879 							 GFP_KERNEL);
4880 			if (!old_opts.s_qf_names[i]) {
4881 				for (j = 0; j < i; j++)
4882 					kfree(old_opts.s_qf_names[j]);
4883 				kfree(orig_data);
4884 				return -ENOMEM;
4885 			}
4886 		} else
4887 			old_opts.s_qf_names[i] = NULL;
4888 #endif
4889 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4890 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4891 
4892 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4893 		err = -EINVAL;
4894 		goto restore_opts;
4895 	}
4896 
4897 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4898 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4899 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4900 			 "during remount not supported; ignoring");
4901 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4902 	}
4903 
4904 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4905 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4906 			ext4_msg(sb, KERN_ERR, "can't mount with "
4907 				 "both data=journal and delalloc");
4908 			err = -EINVAL;
4909 			goto restore_opts;
4910 		}
4911 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4912 			ext4_msg(sb, KERN_ERR, "can't mount with "
4913 				 "both data=journal and dioread_nolock");
4914 			err = -EINVAL;
4915 			goto restore_opts;
4916 		}
4917 		if (test_opt(sb, DAX)) {
4918 			ext4_msg(sb, KERN_ERR, "can't mount with "
4919 				 "both data=journal and dax");
4920 			err = -EINVAL;
4921 			goto restore_opts;
4922 		}
4923 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
4924 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4925 			ext4_msg(sb, KERN_ERR, "can't mount with "
4926 				"journal_async_commit in data=ordered mode");
4927 			err = -EINVAL;
4928 			goto restore_opts;
4929 		}
4930 	}
4931 
4932 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4933 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4934 			"dax flag with busy inodes while remounting");
4935 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4936 	}
4937 
4938 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4939 		ext4_abort(sb, "Abort forced by user");
4940 
4941 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4942 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4943 
4944 	es = sbi->s_es;
4945 
4946 	if (sbi->s_journal) {
4947 		ext4_init_journal_params(sb, sbi->s_journal);
4948 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4949 	}
4950 
4951 	if (*flags & MS_LAZYTIME)
4952 		sb->s_flags |= MS_LAZYTIME;
4953 
4954 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4955 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4956 			err = -EROFS;
4957 			goto restore_opts;
4958 		}
4959 
4960 		if (*flags & MS_RDONLY) {
4961 			err = sync_filesystem(sb);
4962 			if (err < 0)
4963 				goto restore_opts;
4964 			err = dquot_suspend(sb, -1);
4965 			if (err < 0)
4966 				goto restore_opts;
4967 
4968 			/*
4969 			 * First of all, the unconditional stuff we have to do
4970 			 * to disable replay of the journal when we next remount
4971 			 */
4972 			sb->s_flags |= MS_RDONLY;
4973 
4974 			/*
4975 			 * OK, test if we are remounting a valid rw partition
4976 			 * readonly, and if so set the rdonly flag and then
4977 			 * mark the partition as valid again.
4978 			 */
4979 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4980 			    (sbi->s_mount_state & EXT4_VALID_FS))
4981 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4982 
4983 			if (sbi->s_journal)
4984 				ext4_mark_recovery_complete(sb, es);
4985 		} else {
4986 			/* Make sure we can mount this feature set readwrite */
4987 			if (ext4_has_feature_readonly(sb) ||
4988 			    !ext4_feature_set_ok(sb, 0)) {
4989 				err = -EROFS;
4990 				goto restore_opts;
4991 			}
4992 			/*
4993 			 * Make sure the group descriptor checksums
4994 			 * are sane.  If they aren't, refuse to remount r/w.
4995 			 */
4996 			for (g = 0; g < sbi->s_groups_count; g++) {
4997 				struct ext4_group_desc *gdp =
4998 					ext4_get_group_desc(sb, g, NULL);
4999 
5000 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5001 					ext4_msg(sb, KERN_ERR,
5002 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5003 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5004 					       le16_to_cpu(gdp->bg_checksum));
5005 					err = -EFSBADCRC;
5006 					goto restore_opts;
5007 				}
5008 			}
5009 
5010 			/*
5011 			 * If we have an unprocessed orphan list hanging
5012 			 * around from a previously readonly bdev mount,
5013 			 * require a full umount/remount for now.
5014 			 */
5015 			if (es->s_last_orphan) {
5016 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5017 				       "remount RDWR because of unprocessed "
5018 				       "orphan inode list.  Please "
5019 				       "umount/remount instead");
5020 				err = -EINVAL;
5021 				goto restore_opts;
5022 			}
5023 
5024 			/*
5025 			 * Mounting a RDONLY partition read-write, so reread
5026 			 * and store the current valid flag.  (It may have
5027 			 * been changed by e2fsck since we originally mounted
5028 			 * the partition.)
5029 			 */
5030 			if (sbi->s_journal)
5031 				ext4_clear_journal_err(sb, es);
5032 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5033 			if (!ext4_setup_super(sb, es, 0))
5034 				sb->s_flags &= ~MS_RDONLY;
5035 			if (ext4_has_feature_mmp(sb))
5036 				if (ext4_multi_mount_protect(sb,
5037 						le64_to_cpu(es->s_mmp_block))) {
5038 					err = -EROFS;
5039 					goto restore_opts;
5040 				}
5041 			enable_quota = 1;
5042 		}
5043 	}
5044 
5045 	/*
5046 	 * Reinitialize lazy itable initialization thread based on
5047 	 * current settings
5048 	 */
5049 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5050 		ext4_unregister_li_request(sb);
5051 	else {
5052 		ext4_group_t first_not_zeroed;
5053 		first_not_zeroed = ext4_has_uninit_itable(sb);
5054 		ext4_register_li_request(sb, first_not_zeroed);
5055 	}
5056 
5057 	ext4_setup_system_zone(sb);
5058 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5059 		ext4_commit_super(sb, 1);
5060 
5061 #ifdef CONFIG_QUOTA
5062 	/* Release old quota file names */
5063 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5064 		kfree(old_opts.s_qf_names[i]);
5065 	if (enable_quota) {
5066 		if (sb_any_quota_suspended(sb))
5067 			dquot_resume(sb, -1);
5068 		else if (ext4_has_feature_quota(sb)) {
5069 			err = ext4_enable_quotas(sb);
5070 			if (err)
5071 				goto restore_opts;
5072 		}
5073 	}
5074 #endif
5075 
5076 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5077 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5078 	kfree(orig_data);
5079 	return 0;
5080 
5081 restore_opts:
5082 	sb->s_flags = old_sb_flags;
5083 	sbi->s_mount_opt = old_opts.s_mount_opt;
5084 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5085 	sbi->s_resuid = old_opts.s_resuid;
5086 	sbi->s_resgid = old_opts.s_resgid;
5087 	sbi->s_commit_interval = old_opts.s_commit_interval;
5088 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5089 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5090 #ifdef CONFIG_QUOTA
5091 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5092 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5093 		kfree(sbi->s_qf_names[i]);
5094 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5095 	}
5096 #endif
5097 	kfree(orig_data);
5098 	return err;
5099 }
5100 
5101 #ifdef CONFIG_QUOTA
5102 static int ext4_statfs_project(struct super_block *sb,
5103 			       kprojid_t projid, struct kstatfs *buf)
5104 {
5105 	struct kqid qid;
5106 	struct dquot *dquot;
5107 	u64 limit;
5108 	u64 curblock;
5109 
5110 	qid = make_kqid_projid(projid);
5111 	dquot = dqget(sb, qid);
5112 	if (IS_ERR(dquot))
5113 		return PTR_ERR(dquot);
5114 	spin_lock(&dq_data_lock);
5115 
5116 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5117 		 dquot->dq_dqb.dqb_bsoftlimit :
5118 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5119 	if (limit && buf->f_blocks > limit) {
5120 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5121 		buf->f_blocks = limit;
5122 		buf->f_bfree = buf->f_bavail =
5123 			(buf->f_blocks > curblock) ?
5124 			 (buf->f_blocks - curblock) : 0;
5125 	}
5126 
5127 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5128 		dquot->dq_dqb.dqb_isoftlimit :
5129 		dquot->dq_dqb.dqb_ihardlimit;
5130 	if (limit && buf->f_files > limit) {
5131 		buf->f_files = limit;
5132 		buf->f_ffree =
5133 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5134 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5135 	}
5136 
5137 	spin_unlock(&dq_data_lock);
5138 	dqput(dquot);
5139 	return 0;
5140 }
5141 #endif
5142 
5143 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5144 {
5145 	struct super_block *sb = dentry->d_sb;
5146 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5147 	struct ext4_super_block *es = sbi->s_es;
5148 	ext4_fsblk_t overhead = 0, resv_blocks;
5149 	u64 fsid;
5150 	s64 bfree;
5151 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5152 
5153 	if (!test_opt(sb, MINIX_DF))
5154 		overhead = sbi->s_overhead;
5155 
5156 	buf->f_type = EXT4_SUPER_MAGIC;
5157 	buf->f_bsize = sb->s_blocksize;
5158 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5159 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5160 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5161 	/* prevent underflow in case that few free space is available */
5162 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5163 	buf->f_bavail = buf->f_bfree -
5164 			(ext4_r_blocks_count(es) + resv_blocks);
5165 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5166 		buf->f_bavail = 0;
5167 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5168 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5169 	buf->f_namelen = EXT4_NAME_LEN;
5170 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5171 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5172 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5173 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5174 
5175 #ifdef CONFIG_QUOTA
5176 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5177 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5178 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5179 #endif
5180 	return 0;
5181 }
5182 
5183 /* Helper function for writing quotas on sync - we need to start transaction
5184  * before quota file is locked for write. Otherwise the are possible deadlocks:
5185  * Process 1                         Process 2
5186  * ext4_create()                     quota_sync()
5187  *   jbd2_journal_start()                  write_dquot()
5188  *   dquot_initialize()                         down(dqio_mutex)
5189  *     down(dqio_mutex)                    jbd2_journal_start()
5190  *
5191  */
5192 
5193 #ifdef CONFIG_QUOTA
5194 
5195 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5196 {
5197 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5198 }
5199 
5200 static int ext4_write_dquot(struct dquot *dquot)
5201 {
5202 	int ret, err;
5203 	handle_t *handle;
5204 	struct inode *inode;
5205 
5206 	inode = dquot_to_inode(dquot);
5207 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5208 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5209 	if (IS_ERR(handle))
5210 		return PTR_ERR(handle);
5211 	ret = dquot_commit(dquot);
5212 	err = ext4_journal_stop(handle);
5213 	if (!ret)
5214 		ret = err;
5215 	return ret;
5216 }
5217 
5218 static int ext4_acquire_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_INIT_BLOCKS(dquot->dq_sb));
5225 	if (IS_ERR(handle))
5226 		return PTR_ERR(handle);
5227 	ret = dquot_acquire(dquot);
5228 	err = ext4_journal_stop(handle);
5229 	if (!ret)
5230 		ret = err;
5231 	return ret;
5232 }
5233 
5234 static int ext4_release_dquot(struct dquot *dquot)
5235 {
5236 	int ret, err;
5237 	handle_t *handle;
5238 
5239 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5240 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5241 	if (IS_ERR(handle)) {
5242 		/* Release dquot anyway to avoid endless cycle in dqput() */
5243 		dquot_release(dquot);
5244 		return PTR_ERR(handle);
5245 	}
5246 	ret = dquot_release(dquot);
5247 	err = ext4_journal_stop(handle);
5248 	if (!ret)
5249 		ret = err;
5250 	return ret;
5251 }
5252 
5253 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5254 {
5255 	struct super_block *sb = dquot->dq_sb;
5256 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5257 
5258 	/* Are we journaling quotas? */
5259 	if (ext4_has_feature_quota(sb) ||
5260 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5261 		dquot_mark_dquot_dirty(dquot);
5262 		return ext4_write_dquot(dquot);
5263 	} else {
5264 		return dquot_mark_dquot_dirty(dquot);
5265 	}
5266 }
5267 
5268 static int ext4_write_info(struct super_block *sb, int type)
5269 {
5270 	int ret, err;
5271 	handle_t *handle;
5272 
5273 	/* Data block + inode block */
5274 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5275 	if (IS_ERR(handle))
5276 		return PTR_ERR(handle);
5277 	ret = dquot_commit_info(sb, type);
5278 	err = ext4_journal_stop(handle);
5279 	if (!ret)
5280 		ret = err;
5281 	return ret;
5282 }
5283 
5284 /*
5285  * Turn on quotas during mount time - we need to find
5286  * the quota file and such...
5287  */
5288 static int ext4_quota_on_mount(struct super_block *sb, int type)
5289 {
5290 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5291 					EXT4_SB(sb)->s_jquota_fmt, type);
5292 }
5293 
5294 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5295 {
5296 	struct ext4_inode_info *ei = EXT4_I(inode);
5297 
5298 	/* The first argument of lockdep_set_subclass has to be
5299 	 * *exactly* the same as the argument to init_rwsem() --- in
5300 	 * this case, in init_once() --- or lockdep gets unhappy
5301 	 * because the name of the lock is set using the
5302 	 * stringification of the argument to init_rwsem().
5303 	 */
5304 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5305 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5306 }
5307 
5308 /*
5309  * Standard function to be called on quota_on
5310  */
5311 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5312 			 const struct path *path)
5313 {
5314 	int err;
5315 
5316 	if (!test_opt(sb, QUOTA))
5317 		return -EINVAL;
5318 
5319 	/* Quotafile not on the same filesystem? */
5320 	if (path->dentry->d_sb != sb)
5321 		return -EXDEV;
5322 	/* Journaling quota? */
5323 	if (EXT4_SB(sb)->s_qf_names[type]) {
5324 		/* Quotafile not in fs root? */
5325 		if (path->dentry->d_parent != sb->s_root)
5326 			ext4_msg(sb, KERN_WARNING,
5327 				"Quota file not on filesystem root. "
5328 				"Journaled quota will not work");
5329 	}
5330 
5331 	/*
5332 	 * When we journal data on quota file, we have to flush journal to see
5333 	 * all updates to the file when we bypass pagecache...
5334 	 */
5335 	if (EXT4_SB(sb)->s_journal &&
5336 	    ext4_should_journal_data(d_inode(path->dentry))) {
5337 		/*
5338 		 * We don't need to lock updates but journal_flush() could
5339 		 * otherwise be livelocked...
5340 		 */
5341 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5342 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5343 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5344 		if (err)
5345 			return err;
5346 	}
5347 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5348 	err = dquot_quota_on(sb, type, format_id, path);
5349 	if (err)
5350 		lockdep_set_quota_inode(path->dentry->d_inode,
5351 					     I_DATA_SEM_NORMAL);
5352 	return err;
5353 }
5354 
5355 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5356 			     unsigned int flags)
5357 {
5358 	int err;
5359 	struct inode *qf_inode;
5360 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5361 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5362 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5363 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5364 	};
5365 
5366 	BUG_ON(!ext4_has_feature_quota(sb));
5367 
5368 	if (!qf_inums[type])
5369 		return -EPERM;
5370 
5371 	qf_inode = ext4_iget(sb, qf_inums[type]);
5372 	if (IS_ERR(qf_inode)) {
5373 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5374 		return PTR_ERR(qf_inode);
5375 	}
5376 
5377 	/* Don't account quota for quota files to avoid recursion */
5378 	qf_inode->i_flags |= S_NOQUOTA;
5379 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5380 	err = dquot_enable(qf_inode, type, format_id, flags);
5381 	iput(qf_inode);
5382 	if (err)
5383 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5384 
5385 	return err;
5386 }
5387 
5388 /* Enable usage tracking for all quota types. */
5389 static int ext4_enable_quotas(struct super_block *sb)
5390 {
5391 	int type, err = 0;
5392 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5393 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5394 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5395 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5396 	};
5397 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5398 		test_opt(sb, USRQUOTA),
5399 		test_opt(sb, GRPQUOTA),
5400 		test_opt(sb, PRJQUOTA),
5401 	};
5402 
5403 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5404 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5405 		if (qf_inums[type]) {
5406 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5407 				DQUOT_USAGE_ENABLED |
5408 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5409 			if (err) {
5410 				ext4_warning(sb,
5411 					"Failed to enable quota tracking "
5412 					"(type=%d, err=%d). Please run "
5413 					"e2fsck to fix.", type, err);
5414 				return err;
5415 			}
5416 		}
5417 	}
5418 	return 0;
5419 }
5420 
5421 static int ext4_quota_off(struct super_block *sb, int type)
5422 {
5423 	struct inode *inode = sb_dqopt(sb)->files[type];
5424 	handle_t *handle;
5425 
5426 	/* Force all delayed allocation blocks to be allocated.
5427 	 * Caller already holds s_umount sem */
5428 	if (test_opt(sb, DELALLOC))
5429 		sync_filesystem(sb);
5430 
5431 	if (!inode)
5432 		goto out;
5433 
5434 	/* Update modification times of quota files when userspace can
5435 	 * start looking at them */
5436 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5437 	if (IS_ERR(handle))
5438 		goto out;
5439 	inode->i_mtime = inode->i_ctime = current_time(inode);
5440 	ext4_mark_inode_dirty(handle, inode);
5441 	ext4_journal_stop(handle);
5442 
5443 out:
5444 	return dquot_quota_off(sb, type);
5445 }
5446 
5447 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5448  * acquiring the locks... As quota files are never truncated and quota code
5449  * itself serializes the operations (and no one else should touch the files)
5450  * we don't have to be afraid of races */
5451 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5452 			       size_t len, loff_t off)
5453 {
5454 	struct inode *inode = sb_dqopt(sb)->files[type];
5455 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5456 	int offset = off & (sb->s_blocksize - 1);
5457 	int tocopy;
5458 	size_t toread;
5459 	struct buffer_head *bh;
5460 	loff_t i_size = i_size_read(inode);
5461 
5462 	if (off > i_size)
5463 		return 0;
5464 	if (off+len > i_size)
5465 		len = i_size-off;
5466 	toread = len;
5467 	while (toread > 0) {
5468 		tocopy = sb->s_blocksize - offset < toread ?
5469 				sb->s_blocksize - offset : toread;
5470 		bh = ext4_bread(NULL, inode, blk, 0);
5471 		if (IS_ERR(bh))
5472 			return PTR_ERR(bh);
5473 		if (!bh)	/* A hole? */
5474 			memset(data, 0, tocopy);
5475 		else
5476 			memcpy(data, bh->b_data+offset, tocopy);
5477 		brelse(bh);
5478 		offset = 0;
5479 		toread -= tocopy;
5480 		data += tocopy;
5481 		blk++;
5482 	}
5483 	return len;
5484 }
5485 
5486 /* Write to quotafile (we know the transaction is already started and has
5487  * enough credits) */
5488 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5489 				const char *data, size_t len, loff_t off)
5490 {
5491 	struct inode *inode = sb_dqopt(sb)->files[type];
5492 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5493 	int err, offset = off & (sb->s_blocksize - 1);
5494 	int retries = 0;
5495 	struct buffer_head *bh;
5496 	handle_t *handle = journal_current_handle();
5497 
5498 	if (EXT4_SB(sb)->s_journal && !handle) {
5499 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5500 			" cancelled because transaction is not started",
5501 			(unsigned long long)off, (unsigned long long)len);
5502 		return -EIO;
5503 	}
5504 	/*
5505 	 * Since we account only one data block in transaction credits,
5506 	 * then it is impossible to cross a block boundary.
5507 	 */
5508 	if (sb->s_blocksize - offset < len) {
5509 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5510 			" cancelled because not block aligned",
5511 			(unsigned long long)off, (unsigned long long)len);
5512 		return -EIO;
5513 	}
5514 
5515 	do {
5516 		bh = ext4_bread(handle, inode, blk,
5517 				EXT4_GET_BLOCKS_CREATE |
5518 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5519 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5520 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5521 	if (IS_ERR(bh))
5522 		return PTR_ERR(bh);
5523 	if (!bh)
5524 		goto out;
5525 	BUFFER_TRACE(bh, "get write access");
5526 	err = ext4_journal_get_write_access(handle, bh);
5527 	if (err) {
5528 		brelse(bh);
5529 		return err;
5530 	}
5531 	lock_buffer(bh);
5532 	memcpy(bh->b_data+offset, data, len);
5533 	flush_dcache_page(bh->b_page);
5534 	unlock_buffer(bh);
5535 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5536 	brelse(bh);
5537 out:
5538 	if (inode->i_size < off + len) {
5539 		i_size_write(inode, off + len);
5540 		EXT4_I(inode)->i_disksize = inode->i_size;
5541 		ext4_mark_inode_dirty(handle, inode);
5542 	}
5543 	return len;
5544 }
5545 
5546 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5547 {
5548 	const struct quota_format_ops	*ops;
5549 
5550 	if (!sb_has_quota_loaded(sb, qid->type))
5551 		return -ESRCH;
5552 	ops = sb_dqopt(sb)->ops[qid->type];
5553 	if (!ops || !ops->get_next_id)
5554 		return -ENOSYS;
5555 	return dquot_get_next_id(sb, qid);
5556 }
5557 #endif
5558 
5559 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5560 		       const char *dev_name, void *data)
5561 {
5562 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5563 }
5564 
5565 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5566 static inline void register_as_ext2(void)
5567 {
5568 	int err = register_filesystem(&ext2_fs_type);
5569 	if (err)
5570 		printk(KERN_WARNING
5571 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5572 }
5573 
5574 static inline void unregister_as_ext2(void)
5575 {
5576 	unregister_filesystem(&ext2_fs_type);
5577 }
5578 
5579 static inline int ext2_feature_set_ok(struct super_block *sb)
5580 {
5581 	if (ext4_has_unknown_ext2_incompat_features(sb))
5582 		return 0;
5583 	if (sb->s_flags & MS_RDONLY)
5584 		return 1;
5585 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5586 		return 0;
5587 	return 1;
5588 }
5589 #else
5590 static inline void register_as_ext2(void) { }
5591 static inline void unregister_as_ext2(void) { }
5592 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5593 #endif
5594 
5595 static inline void register_as_ext3(void)
5596 {
5597 	int err = register_filesystem(&ext3_fs_type);
5598 	if (err)
5599 		printk(KERN_WARNING
5600 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5601 }
5602 
5603 static inline void unregister_as_ext3(void)
5604 {
5605 	unregister_filesystem(&ext3_fs_type);
5606 }
5607 
5608 static inline int ext3_feature_set_ok(struct super_block *sb)
5609 {
5610 	if (ext4_has_unknown_ext3_incompat_features(sb))
5611 		return 0;
5612 	if (!ext4_has_feature_journal(sb))
5613 		return 0;
5614 	if (sb->s_flags & MS_RDONLY)
5615 		return 1;
5616 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5617 		return 0;
5618 	return 1;
5619 }
5620 
5621 static struct file_system_type ext4_fs_type = {
5622 	.owner		= THIS_MODULE,
5623 	.name		= "ext4",
5624 	.mount		= ext4_mount,
5625 	.kill_sb	= kill_block_super,
5626 	.fs_flags	= FS_REQUIRES_DEV,
5627 };
5628 MODULE_ALIAS_FS("ext4");
5629 
5630 /* Shared across all ext4 file systems */
5631 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5632 
5633 static int __init ext4_init_fs(void)
5634 {
5635 	int i, err;
5636 
5637 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5638 	ext4_li_info = NULL;
5639 	mutex_init(&ext4_li_mtx);
5640 
5641 	/* Build-time check for flags consistency */
5642 	ext4_check_flag_values();
5643 
5644 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5645 		init_waitqueue_head(&ext4__ioend_wq[i]);
5646 
5647 	err = ext4_init_es();
5648 	if (err)
5649 		return err;
5650 
5651 	err = ext4_init_pageio();
5652 	if (err)
5653 		goto out5;
5654 
5655 	err = ext4_init_system_zone();
5656 	if (err)
5657 		goto out4;
5658 
5659 	err = ext4_init_sysfs();
5660 	if (err)
5661 		goto out3;
5662 
5663 	err = ext4_init_mballoc();
5664 	if (err)
5665 		goto out2;
5666 	err = init_inodecache();
5667 	if (err)
5668 		goto out1;
5669 	register_as_ext3();
5670 	register_as_ext2();
5671 	err = register_filesystem(&ext4_fs_type);
5672 	if (err)
5673 		goto out;
5674 
5675 	return 0;
5676 out:
5677 	unregister_as_ext2();
5678 	unregister_as_ext3();
5679 	destroy_inodecache();
5680 out1:
5681 	ext4_exit_mballoc();
5682 out2:
5683 	ext4_exit_sysfs();
5684 out3:
5685 	ext4_exit_system_zone();
5686 out4:
5687 	ext4_exit_pageio();
5688 out5:
5689 	ext4_exit_es();
5690 
5691 	return err;
5692 }
5693 
5694 static void __exit ext4_exit_fs(void)
5695 {
5696 	ext4_destroy_lazyinit_thread();
5697 	unregister_as_ext2();
5698 	unregister_as_ext3();
5699 	unregister_filesystem(&ext4_fs_type);
5700 	destroy_inodecache();
5701 	ext4_exit_mballoc();
5702 	ext4_exit_sysfs();
5703 	ext4_exit_system_zone();
5704 	ext4_exit_pageio();
5705 	ext4_exit_es();
5706 }
5707 
5708 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5709 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5710 MODULE_LICENSE("GPL");
5711 module_init(ext4_init_fs)
5712 module_exit(ext4_exit_fs)
5713