xref: /openbmc/linux/fs/ext4/super.c (revision bb0eb050)
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/dax.h>
41 #include <linux/cleancache.h>
42 #include <linux/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 #include "fsmap.h"
54 
55 #define CREATE_TRACE_POINTS
56 #include <trace/events/ext4.h>
57 
58 static struct ext4_lazy_init *ext4_li_info;
59 static struct mutex ext4_li_mtx;
60 static struct ratelimit_state ext4_mount_msg_ratelimit;
61 
62 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
63 			     unsigned long journal_devnum);
64 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
65 static int ext4_commit_super(struct super_block *sb, int sync);
66 static void ext4_mark_recovery_complete(struct super_block *sb,
67 					struct ext4_super_block *es);
68 static void ext4_clear_journal_err(struct super_block *sb,
69 				   struct ext4_super_block *es);
70 static int ext4_sync_fs(struct super_block *sb, int wait);
71 static int ext4_remount(struct super_block *sb, int *flags, char *data);
72 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
73 static int ext4_unfreeze(struct super_block *sb);
74 static int ext4_freeze(struct super_block *sb);
75 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
76 		       const char *dev_name, void *data);
77 static inline int ext2_feature_set_ok(struct super_block *sb);
78 static inline int ext3_feature_set_ok(struct super_block *sb);
79 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
80 static void ext4_destroy_lazyinit_thread(void);
81 static void ext4_unregister_li_request(struct super_block *sb);
82 static void ext4_clear_request_list(void);
83 static struct inode *ext4_get_journal_inode(struct super_block *sb,
84 					    unsigned int journal_inum);
85 
86 /*
87  * Lock ordering
88  *
89  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
90  * i_mmap_rwsem (inode->i_mmap_rwsem)!
91  *
92  * page fault path:
93  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
94  *   page lock -> i_data_sem (rw)
95  *
96  * buffered write path:
97  * sb_start_write -> i_mutex -> mmap_sem
98  * sb_start_write -> i_mutex -> transaction start -> page lock ->
99  *   i_data_sem (rw)
100  *
101  * truncate:
102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
103  *   i_mmap_rwsem (w) -> page lock
104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
105  *   transaction start -> i_data_sem (rw)
106  *
107  * direct IO:
108  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
109  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
110  *   transaction start -> i_data_sem (rw)
111  *
112  * writepages:
113  * transaction start -> page lock(s) -> i_data_sem (rw)
114  */
115 
116 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
117 static struct file_system_type ext2_fs_type = {
118 	.owner		= THIS_MODULE,
119 	.name		= "ext2",
120 	.mount		= ext4_mount,
121 	.kill_sb	= kill_block_super,
122 	.fs_flags	= FS_REQUIRES_DEV,
123 };
124 MODULE_ALIAS_FS("ext2");
125 MODULE_ALIAS("ext2");
126 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
127 #else
128 #define IS_EXT2_SB(sb) (0)
129 #endif
130 
131 
132 static struct file_system_type ext3_fs_type = {
133 	.owner		= THIS_MODULE,
134 	.name		= "ext3",
135 	.mount		= ext4_mount,
136 	.kill_sb	= kill_block_super,
137 	.fs_flags	= FS_REQUIRES_DEV,
138 };
139 MODULE_ALIAS_FS("ext3");
140 MODULE_ALIAS("ext3");
141 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
142 
143 static int ext4_verify_csum_type(struct super_block *sb,
144 				 struct ext4_super_block *es)
145 {
146 	if (!ext4_has_feature_metadata_csum(sb))
147 		return 1;
148 
149 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
150 }
151 
152 static __le32 ext4_superblock_csum(struct super_block *sb,
153 				   struct ext4_super_block *es)
154 {
155 	struct ext4_sb_info *sbi = EXT4_SB(sb);
156 	int offset = offsetof(struct ext4_super_block, s_checksum);
157 	__u32 csum;
158 
159 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
160 
161 	return cpu_to_le32(csum);
162 }
163 
164 static int ext4_superblock_csum_verify(struct super_block *sb,
165 				       struct ext4_super_block *es)
166 {
167 	if (!ext4_has_metadata_csum(sb))
168 		return 1;
169 
170 	return es->s_checksum == ext4_superblock_csum(sb, es);
171 }
172 
173 void ext4_superblock_csum_set(struct super_block *sb)
174 {
175 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
176 
177 	if (!ext4_has_metadata_csum(sb))
178 		return;
179 
180 	es->s_checksum = ext4_superblock_csum(sb, es);
181 }
182 
183 void *ext4_kvmalloc(size_t size, gfp_t flags)
184 {
185 	void *ret;
186 
187 	ret = kmalloc(size, flags | __GFP_NOWARN);
188 	if (!ret)
189 		ret = __vmalloc(size, flags, PAGE_KERNEL);
190 	return ret;
191 }
192 
193 void *ext4_kvzalloc(size_t size, gfp_t flags)
194 {
195 	void *ret;
196 
197 	ret = kzalloc(size, flags | __GFP_NOWARN);
198 	if (!ret)
199 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
200 	return ret;
201 }
202 
203 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
204 			       struct ext4_group_desc *bg)
205 {
206 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
207 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
208 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
209 }
210 
211 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
212 			       struct ext4_group_desc *bg)
213 {
214 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
215 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
216 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
217 }
218 
219 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
220 			      struct ext4_group_desc *bg)
221 {
222 	return le32_to_cpu(bg->bg_inode_table_lo) |
223 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
224 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
225 }
226 
227 __u32 ext4_free_group_clusters(struct super_block *sb,
228 			       struct ext4_group_desc *bg)
229 {
230 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
231 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
233 }
234 
235 __u32 ext4_free_inodes_count(struct super_block *sb,
236 			      struct ext4_group_desc *bg)
237 {
238 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
239 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
241 }
242 
243 __u32 ext4_used_dirs_count(struct super_block *sb,
244 			      struct ext4_group_desc *bg)
245 {
246 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
247 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
249 }
250 
251 __u32 ext4_itable_unused_count(struct super_block *sb,
252 			      struct ext4_group_desc *bg)
253 {
254 	return le16_to_cpu(bg->bg_itable_unused_lo) |
255 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
257 }
258 
259 void ext4_block_bitmap_set(struct super_block *sb,
260 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
261 {
262 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
263 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
264 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
265 }
266 
267 void ext4_inode_bitmap_set(struct super_block *sb,
268 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
269 {
270 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
271 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
272 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
273 }
274 
275 void ext4_inode_table_set(struct super_block *sb,
276 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
277 {
278 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
279 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
280 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
281 }
282 
283 void ext4_free_group_clusters_set(struct super_block *sb,
284 				  struct ext4_group_desc *bg, __u32 count)
285 {
286 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
287 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
289 }
290 
291 void ext4_free_inodes_set(struct super_block *sb,
292 			  struct ext4_group_desc *bg, __u32 count)
293 {
294 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
295 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
297 }
298 
299 void ext4_used_dirs_set(struct super_block *sb,
300 			  struct ext4_group_desc *bg, __u32 count)
301 {
302 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
303 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
305 }
306 
307 void ext4_itable_unused_set(struct super_block *sb,
308 			  struct ext4_group_desc *bg, __u32 count)
309 {
310 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
311 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
313 }
314 
315 
316 static void __save_error_info(struct super_block *sb, const char *func,
317 			    unsigned int line)
318 {
319 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
320 
321 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
322 	if (bdev_read_only(sb->s_bdev))
323 		return;
324 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
325 	es->s_last_error_time = cpu_to_le32(get_seconds());
326 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
327 	es->s_last_error_line = cpu_to_le32(line);
328 	if (!es->s_first_error_time) {
329 		es->s_first_error_time = es->s_last_error_time;
330 		strncpy(es->s_first_error_func, func,
331 			sizeof(es->s_first_error_func));
332 		es->s_first_error_line = cpu_to_le32(line);
333 		es->s_first_error_ino = es->s_last_error_ino;
334 		es->s_first_error_block = es->s_last_error_block;
335 	}
336 	/*
337 	 * Start the daily error reporting function if it hasn't been
338 	 * started already
339 	 */
340 	if (!es->s_error_count)
341 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
342 	le32_add_cpu(&es->s_error_count, 1);
343 }
344 
345 static void save_error_info(struct super_block *sb, const char *func,
346 			    unsigned int line)
347 {
348 	__save_error_info(sb, func, line);
349 	ext4_commit_super(sb, 1);
350 }
351 
352 /*
353  * The del_gendisk() function uninitializes the disk-specific data
354  * structures, including the bdi structure, without telling anyone
355  * else.  Once this happens, any attempt to call mark_buffer_dirty()
356  * (for example, by ext4_commit_super), will cause a kernel OOPS.
357  * This is a kludge to prevent these oops until we can put in a proper
358  * hook in del_gendisk() to inform the VFS and file system layers.
359  */
360 static int block_device_ejected(struct super_block *sb)
361 {
362 	struct inode *bd_inode = sb->s_bdev->bd_inode;
363 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
364 
365 	return bdi->dev == NULL;
366 }
367 
368 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
369 {
370 	struct super_block		*sb = journal->j_private;
371 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
372 	int				error = is_journal_aborted(journal);
373 	struct ext4_journal_cb_entry	*jce;
374 
375 	BUG_ON(txn->t_state == T_FINISHED);
376 	spin_lock(&sbi->s_md_lock);
377 	while (!list_empty(&txn->t_private_list)) {
378 		jce = list_entry(txn->t_private_list.next,
379 				 struct ext4_journal_cb_entry, jce_list);
380 		list_del_init(&jce->jce_list);
381 		spin_unlock(&sbi->s_md_lock);
382 		jce->jce_func(sb, jce, error);
383 		spin_lock(&sbi->s_md_lock);
384 	}
385 	spin_unlock(&sbi->s_md_lock);
386 }
387 
388 /* Deal with the reporting of failure conditions on a filesystem such as
389  * inconsistencies detected or read IO failures.
390  *
391  * On ext2, we can store the error state of the filesystem in the
392  * superblock.  That is not possible on ext4, because we may have other
393  * write ordering constraints on the superblock which prevent us from
394  * writing it out straight away; and given that the journal is about to
395  * be aborted, we can't rely on the current, or future, transactions to
396  * write out the superblock safely.
397  *
398  * We'll just use the jbd2_journal_abort() error code to record an error in
399  * the journal instead.  On recovery, the journal will complain about
400  * that error until we've noted it down and cleared it.
401  */
402 
403 static void ext4_handle_error(struct super_block *sb)
404 {
405 	if (sb->s_flags & MS_RDONLY)
406 		return;
407 
408 	if (!test_opt(sb, ERRORS_CONT)) {
409 		journal_t *journal = EXT4_SB(sb)->s_journal;
410 
411 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
412 		if (journal)
413 			jbd2_journal_abort(journal, -EIO);
414 	}
415 	if (test_opt(sb, ERRORS_RO)) {
416 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
417 		/*
418 		 * Make sure updated value of ->s_mount_flags will be visible
419 		 * before ->s_flags update
420 		 */
421 		smp_wmb();
422 		sb->s_flags |= MS_RDONLY;
423 	}
424 	if (test_opt(sb, ERRORS_PANIC)) {
425 		if (EXT4_SB(sb)->s_journal &&
426 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
427 			return;
428 		panic("EXT4-fs (device %s): panic forced after error\n",
429 			sb->s_id);
430 	}
431 }
432 
433 #define ext4_error_ratelimit(sb)					\
434 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
435 			     "EXT4-fs error")
436 
437 void __ext4_error(struct super_block *sb, const char *function,
438 		  unsigned int line, const char *fmt, ...)
439 {
440 	struct va_format vaf;
441 	va_list args;
442 
443 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
444 		return;
445 
446 	if (ext4_error_ratelimit(sb)) {
447 		va_start(args, fmt);
448 		vaf.fmt = fmt;
449 		vaf.va = &args;
450 		printk(KERN_CRIT
451 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
452 		       sb->s_id, function, line, current->comm, &vaf);
453 		va_end(args);
454 	}
455 	save_error_info(sb, function, line);
456 	ext4_handle_error(sb);
457 }
458 
459 void __ext4_error_inode(struct inode *inode, const char *function,
460 			unsigned int line, ext4_fsblk_t block,
461 			const char *fmt, ...)
462 {
463 	va_list args;
464 	struct va_format vaf;
465 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
466 
467 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
468 		return;
469 
470 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
471 	es->s_last_error_block = cpu_to_le64(block);
472 	if (ext4_error_ratelimit(inode->i_sb)) {
473 		va_start(args, fmt);
474 		vaf.fmt = fmt;
475 		vaf.va = &args;
476 		if (block)
477 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
478 			       "inode #%lu: block %llu: comm %s: %pV\n",
479 			       inode->i_sb->s_id, function, line, inode->i_ino,
480 			       block, current->comm, &vaf);
481 		else
482 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
483 			       "inode #%lu: comm %s: %pV\n",
484 			       inode->i_sb->s_id, function, line, inode->i_ino,
485 			       current->comm, &vaf);
486 		va_end(args);
487 	}
488 	save_error_info(inode->i_sb, function, line);
489 	ext4_handle_error(inode->i_sb);
490 }
491 
492 void __ext4_error_file(struct file *file, const char *function,
493 		       unsigned int line, ext4_fsblk_t block,
494 		       const char *fmt, ...)
495 {
496 	va_list args;
497 	struct va_format vaf;
498 	struct ext4_super_block *es;
499 	struct inode *inode = file_inode(file);
500 	char pathname[80], *path;
501 
502 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
503 		return;
504 
505 	es = EXT4_SB(inode->i_sb)->s_es;
506 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
507 	if (ext4_error_ratelimit(inode->i_sb)) {
508 		path = file_path(file, pathname, sizeof(pathname));
509 		if (IS_ERR(path))
510 			path = "(unknown)";
511 		va_start(args, fmt);
512 		vaf.fmt = fmt;
513 		vaf.va = &args;
514 		if (block)
515 			printk(KERN_CRIT
516 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
517 			       "block %llu: comm %s: path %s: %pV\n",
518 			       inode->i_sb->s_id, function, line, inode->i_ino,
519 			       block, current->comm, path, &vaf);
520 		else
521 			printk(KERN_CRIT
522 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
523 			       "comm %s: path %s: %pV\n",
524 			       inode->i_sb->s_id, function, line, inode->i_ino,
525 			       current->comm, path, &vaf);
526 		va_end(args);
527 	}
528 	save_error_info(inode->i_sb, function, line);
529 	ext4_handle_error(inode->i_sb);
530 }
531 
532 const char *ext4_decode_error(struct super_block *sb, int errno,
533 			      char nbuf[16])
534 {
535 	char *errstr = NULL;
536 
537 	switch (errno) {
538 	case -EFSCORRUPTED:
539 		errstr = "Corrupt filesystem";
540 		break;
541 	case -EFSBADCRC:
542 		errstr = "Filesystem failed CRC";
543 		break;
544 	case -EIO:
545 		errstr = "IO failure";
546 		break;
547 	case -ENOMEM:
548 		errstr = "Out of memory";
549 		break;
550 	case -EROFS:
551 		if (!sb || (EXT4_SB(sb)->s_journal &&
552 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
553 			errstr = "Journal has aborted";
554 		else
555 			errstr = "Readonly filesystem";
556 		break;
557 	default:
558 		/* If the caller passed in an extra buffer for unknown
559 		 * errors, textualise them now.  Else we just return
560 		 * NULL. */
561 		if (nbuf) {
562 			/* Check for truncated error codes... */
563 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
564 				errstr = nbuf;
565 		}
566 		break;
567 	}
568 
569 	return errstr;
570 }
571 
572 /* __ext4_std_error decodes expected errors from journaling functions
573  * automatically and invokes the appropriate error response.  */
574 
575 void __ext4_std_error(struct super_block *sb, const char *function,
576 		      unsigned int line, int errno)
577 {
578 	char nbuf[16];
579 	const char *errstr;
580 
581 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
582 		return;
583 
584 	/* Special case: if the error is EROFS, and we're not already
585 	 * inside a transaction, then there's really no point in logging
586 	 * an error. */
587 	if (errno == -EROFS && journal_current_handle() == NULL &&
588 	    (sb->s_flags & MS_RDONLY))
589 		return;
590 
591 	if (ext4_error_ratelimit(sb)) {
592 		errstr = ext4_decode_error(sb, errno, nbuf);
593 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
594 		       sb->s_id, function, line, errstr);
595 	}
596 
597 	save_error_info(sb, function, line);
598 	ext4_handle_error(sb);
599 }
600 
601 /*
602  * ext4_abort is a much stronger failure handler than ext4_error.  The
603  * abort function may be used to deal with unrecoverable failures such
604  * as journal IO errors or ENOMEM at a critical moment in log management.
605  *
606  * We unconditionally force the filesystem into an ABORT|READONLY state,
607  * unless the error response on the fs has been set to panic in which
608  * case we take the easy way out and panic immediately.
609  */
610 
611 void __ext4_abort(struct super_block *sb, const char *function,
612 		unsigned int line, const char *fmt, ...)
613 {
614 	struct va_format vaf;
615 	va_list args;
616 
617 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
618 		return;
619 
620 	save_error_info(sb, function, line);
621 	va_start(args, fmt);
622 	vaf.fmt = fmt;
623 	vaf.va = &args;
624 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
625 	       sb->s_id, function, line, &vaf);
626 	va_end(args);
627 
628 	if ((sb->s_flags & MS_RDONLY) == 0) {
629 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
630 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
631 		/*
632 		 * Make sure updated value of ->s_mount_flags will be visible
633 		 * before ->s_flags update
634 		 */
635 		smp_wmb();
636 		sb->s_flags |= MS_RDONLY;
637 		if (EXT4_SB(sb)->s_journal)
638 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
639 		save_error_info(sb, function, line);
640 	}
641 	if (test_opt(sb, ERRORS_PANIC)) {
642 		if (EXT4_SB(sb)->s_journal &&
643 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
644 			return;
645 		panic("EXT4-fs panic from previous error\n");
646 	}
647 }
648 
649 void __ext4_msg(struct super_block *sb,
650 		const char *prefix, const char *fmt, ...)
651 {
652 	struct va_format vaf;
653 	va_list args;
654 
655 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
656 		return;
657 
658 	va_start(args, fmt);
659 	vaf.fmt = fmt;
660 	vaf.va = &args;
661 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
662 	va_end(args);
663 }
664 
665 #define ext4_warning_ratelimit(sb)					\
666 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
667 			     "EXT4-fs warning")
668 
669 void __ext4_warning(struct super_block *sb, const char *function,
670 		    unsigned int line, const char *fmt, ...)
671 {
672 	struct va_format vaf;
673 	va_list args;
674 
675 	if (!ext4_warning_ratelimit(sb))
676 		return;
677 
678 	va_start(args, fmt);
679 	vaf.fmt = fmt;
680 	vaf.va = &args;
681 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
682 	       sb->s_id, function, line, &vaf);
683 	va_end(args);
684 }
685 
686 void __ext4_warning_inode(const struct inode *inode, const char *function,
687 			  unsigned int line, const char *fmt, ...)
688 {
689 	struct va_format vaf;
690 	va_list args;
691 
692 	if (!ext4_warning_ratelimit(inode->i_sb))
693 		return;
694 
695 	va_start(args, fmt);
696 	vaf.fmt = fmt;
697 	vaf.va = &args;
698 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
699 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
700 	       function, line, inode->i_ino, current->comm, &vaf);
701 	va_end(args);
702 }
703 
704 void __ext4_grp_locked_error(const char *function, unsigned int line,
705 			     struct super_block *sb, ext4_group_t grp,
706 			     unsigned long ino, ext4_fsblk_t block,
707 			     const char *fmt, ...)
708 __releases(bitlock)
709 __acquires(bitlock)
710 {
711 	struct va_format vaf;
712 	va_list args;
713 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
714 
715 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
716 		return;
717 
718 	es->s_last_error_ino = cpu_to_le32(ino);
719 	es->s_last_error_block = cpu_to_le64(block);
720 	__save_error_info(sb, function, line);
721 
722 	if (ext4_error_ratelimit(sb)) {
723 		va_start(args, fmt);
724 		vaf.fmt = fmt;
725 		vaf.va = &args;
726 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
727 		       sb->s_id, function, line, grp);
728 		if (ino)
729 			printk(KERN_CONT "inode %lu: ", ino);
730 		if (block)
731 			printk(KERN_CONT "block %llu:",
732 			       (unsigned long long) block);
733 		printk(KERN_CONT "%pV\n", &vaf);
734 		va_end(args);
735 	}
736 
737 	if (test_opt(sb, ERRORS_CONT)) {
738 		ext4_commit_super(sb, 0);
739 		return;
740 	}
741 
742 	ext4_unlock_group(sb, grp);
743 	ext4_handle_error(sb);
744 	/*
745 	 * We only get here in the ERRORS_RO case; relocking the group
746 	 * may be dangerous, but nothing bad will happen since the
747 	 * filesystem will have already been marked read/only and the
748 	 * journal has been aborted.  We return 1 as a hint to callers
749 	 * who might what to use the return value from
750 	 * ext4_grp_locked_error() to distinguish between the
751 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
752 	 * aggressively from the ext4 function in question, with a
753 	 * more appropriate error code.
754 	 */
755 	ext4_lock_group(sb, grp);
756 	return;
757 }
758 
759 void ext4_update_dynamic_rev(struct super_block *sb)
760 {
761 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
762 
763 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
764 		return;
765 
766 	ext4_warning(sb,
767 		     "updating to rev %d because of new feature flag, "
768 		     "running e2fsck is recommended",
769 		     EXT4_DYNAMIC_REV);
770 
771 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
772 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
773 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
774 	/* leave es->s_feature_*compat flags alone */
775 	/* es->s_uuid will be set by e2fsck if empty */
776 
777 	/*
778 	 * The rest of the superblock fields should be zero, and if not it
779 	 * means they are likely already in use, so leave them alone.  We
780 	 * can leave it up to e2fsck to clean up any inconsistencies there.
781 	 */
782 }
783 
784 /*
785  * Open the external journal device
786  */
787 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
788 {
789 	struct block_device *bdev;
790 	char b[BDEVNAME_SIZE];
791 
792 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
793 	if (IS_ERR(bdev))
794 		goto fail;
795 	return bdev;
796 
797 fail:
798 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
799 			__bdevname(dev, b), PTR_ERR(bdev));
800 	return NULL;
801 }
802 
803 /*
804  * Release the journal device
805  */
806 static void ext4_blkdev_put(struct block_device *bdev)
807 {
808 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
809 }
810 
811 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
812 {
813 	struct block_device *bdev;
814 	bdev = sbi->journal_bdev;
815 	if (bdev) {
816 		ext4_blkdev_put(bdev);
817 		sbi->journal_bdev = NULL;
818 	}
819 }
820 
821 static inline struct inode *orphan_list_entry(struct list_head *l)
822 {
823 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
824 }
825 
826 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
827 {
828 	struct list_head *l;
829 
830 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
831 		 le32_to_cpu(sbi->s_es->s_last_orphan));
832 
833 	printk(KERN_ERR "sb_info orphan list:\n");
834 	list_for_each(l, &sbi->s_orphan) {
835 		struct inode *inode = orphan_list_entry(l);
836 		printk(KERN_ERR "  "
837 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
838 		       inode->i_sb->s_id, inode->i_ino, inode,
839 		       inode->i_mode, inode->i_nlink,
840 		       NEXT_ORPHAN(inode));
841 	}
842 }
843 
844 #ifdef CONFIG_QUOTA
845 static int ext4_quota_off(struct super_block *sb, int type);
846 
847 static inline void ext4_quota_off_umount(struct super_block *sb)
848 {
849 	int type;
850 
851 	if (ext4_has_feature_quota(sb)) {
852 		dquot_disable(sb, -1,
853 			      DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
854 	} else {
855 		/* Use our quota_off function to clear inode flags etc. */
856 		for (type = 0; type < EXT4_MAXQUOTAS; type++)
857 			ext4_quota_off(sb, type);
858 	}
859 }
860 #else
861 static inline void ext4_quota_off_umount(struct super_block *sb)
862 {
863 }
864 #endif
865 
866 static void ext4_put_super(struct super_block *sb)
867 {
868 	struct ext4_sb_info *sbi = EXT4_SB(sb);
869 	struct ext4_super_block *es = sbi->s_es;
870 	int aborted = 0;
871 	int i, err;
872 
873 	ext4_unregister_li_request(sb);
874 	ext4_quota_off_umount(sb);
875 
876 	flush_workqueue(sbi->rsv_conversion_wq);
877 	destroy_workqueue(sbi->rsv_conversion_wq);
878 
879 	if (sbi->s_journal) {
880 		aborted = is_journal_aborted(sbi->s_journal);
881 		err = jbd2_journal_destroy(sbi->s_journal);
882 		sbi->s_journal = NULL;
883 		if ((err < 0) && !aborted)
884 			ext4_abort(sb, "Couldn't clean up the journal");
885 	}
886 
887 	ext4_unregister_sysfs(sb);
888 	ext4_es_unregister_shrinker(sbi);
889 	del_timer_sync(&sbi->s_err_report);
890 	ext4_release_system_zone(sb);
891 	ext4_mb_release(sb);
892 	ext4_ext_release(sb);
893 
894 	if (!(sb->s_flags & MS_RDONLY) && !aborted) {
895 		ext4_clear_feature_journal_needs_recovery(sb);
896 		es->s_state = cpu_to_le16(sbi->s_mount_state);
897 	}
898 	if (!(sb->s_flags & MS_RDONLY))
899 		ext4_commit_super(sb, 1);
900 
901 	for (i = 0; i < sbi->s_gdb_count; i++)
902 		brelse(sbi->s_group_desc[i]);
903 	kvfree(sbi->s_group_desc);
904 	kvfree(sbi->s_flex_groups);
905 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
906 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
907 	percpu_counter_destroy(&sbi->s_dirs_counter);
908 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
909 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
910 #ifdef CONFIG_QUOTA
911 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
912 		kfree(sbi->s_qf_names[i]);
913 #endif
914 
915 	/* Debugging code just in case the in-memory inode orphan list
916 	 * isn't empty.  The on-disk one can be non-empty if we've
917 	 * detected an error and taken the fs readonly, but the
918 	 * in-memory list had better be clean by this point. */
919 	if (!list_empty(&sbi->s_orphan))
920 		dump_orphan_list(sb, sbi);
921 	J_ASSERT(list_empty(&sbi->s_orphan));
922 
923 	sync_blockdev(sb->s_bdev);
924 	invalidate_bdev(sb->s_bdev);
925 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
926 		/*
927 		 * Invalidate the journal device's buffers.  We don't want them
928 		 * floating about in memory - the physical journal device may
929 		 * hotswapped, and it breaks the `ro-after' testing code.
930 		 */
931 		sync_blockdev(sbi->journal_bdev);
932 		invalidate_bdev(sbi->journal_bdev);
933 		ext4_blkdev_remove(sbi);
934 	}
935 	if (sbi->s_mb_cache) {
936 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
937 		sbi->s_mb_cache = NULL;
938 	}
939 	if (sbi->s_mmp_tsk)
940 		kthread_stop(sbi->s_mmp_tsk);
941 	brelse(sbi->s_sbh);
942 	sb->s_fs_info = NULL;
943 	/*
944 	 * Now that we are completely done shutting down the
945 	 * superblock, we need to actually destroy the kobject.
946 	 */
947 	kobject_put(&sbi->s_kobj);
948 	wait_for_completion(&sbi->s_kobj_unregister);
949 	if (sbi->s_chksum_driver)
950 		crypto_free_shash(sbi->s_chksum_driver);
951 	kfree(sbi->s_blockgroup_lock);
952 	kfree(sbi);
953 }
954 
955 static struct kmem_cache *ext4_inode_cachep;
956 
957 /*
958  * Called inside transaction, so use GFP_NOFS
959  */
960 static struct inode *ext4_alloc_inode(struct super_block *sb)
961 {
962 	struct ext4_inode_info *ei;
963 
964 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
965 	if (!ei)
966 		return NULL;
967 
968 	ei->vfs_inode.i_version = 1;
969 	spin_lock_init(&ei->i_raw_lock);
970 	INIT_LIST_HEAD(&ei->i_prealloc_list);
971 	spin_lock_init(&ei->i_prealloc_lock);
972 	ext4_es_init_tree(&ei->i_es_tree);
973 	rwlock_init(&ei->i_es_lock);
974 	INIT_LIST_HEAD(&ei->i_es_list);
975 	ei->i_es_all_nr = 0;
976 	ei->i_es_shk_nr = 0;
977 	ei->i_es_shrink_lblk = 0;
978 	ei->i_reserved_data_blocks = 0;
979 	ei->i_reserved_meta_blocks = 0;
980 	ei->i_allocated_meta_blocks = 0;
981 	ei->i_da_metadata_calc_len = 0;
982 	ei->i_da_metadata_calc_last_lblock = 0;
983 	spin_lock_init(&(ei->i_block_reservation_lock));
984 #ifdef CONFIG_QUOTA
985 	ei->i_reserved_quota = 0;
986 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
987 #endif
988 	ei->jinode = NULL;
989 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
990 	spin_lock_init(&ei->i_completed_io_lock);
991 	ei->i_sync_tid = 0;
992 	ei->i_datasync_tid = 0;
993 	atomic_set(&ei->i_unwritten, 0);
994 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
995 	return &ei->vfs_inode;
996 }
997 
998 static int ext4_drop_inode(struct inode *inode)
999 {
1000 	int drop = generic_drop_inode(inode);
1001 
1002 	trace_ext4_drop_inode(inode, drop);
1003 	return drop;
1004 }
1005 
1006 static void ext4_i_callback(struct rcu_head *head)
1007 {
1008 	struct inode *inode = container_of(head, struct inode, i_rcu);
1009 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1010 }
1011 
1012 static void ext4_destroy_inode(struct inode *inode)
1013 {
1014 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1015 		ext4_msg(inode->i_sb, KERN_ERR,
1016 			 "Inode %lu (%p): orphan list check failed!",
1017 			 inode->i_ino, EXT4_I(inode));
1018 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1019 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1020 				true);
1021 		dump_stack();
1022 	}
1023 	call_rcu(&inode->i_rcu, ext4_i_callback);
1024 }
1025 
1026 static void init_once(void *foo)
1027 {
1028 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1029 
1030 	INIT_LIST_HEAD(&ei->i_orphan);
1031 	init_rwsem(&ei->xattr_sem);
1032 	init_rwsem(&ei->i_data_sem);
1033 	init_rwsem(&ei->i_mmap_sem);
1034 	inode_init_once(&ei->vfs_inode);
1035 }
1036 
1037 static int __init init_inodecache(void)
1038 {
1039 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1040 					     sizeof(struct ext4_inode_info),
1041 					     0, (SLAB_RECLAIM_ACCOUNT|
1042 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1043 					     init_once);
1044 	if (ext4_inode_cachep == NULL)
1045 		return -ENOMEM;
1046 	return 0;
1047 }
1048 
1049 static void destroy_inodecache(void)
1050 {
1051 	/*
1052 	 * Make sure all delayed rcu free inodes are flushed before we
1053 	 * destroy cache.
1054 	 */
1055 	rcu_barrier();
1056 	kmem_cache_destroy(ext4_inode_cachep);
1057 }
1058 
1059 void ext4_clear_inode(struct inode *inode)
1060 {
1061 	invalidate_inode_buffers(inode);
1062 	clear_inode(inode);
1063 	dquot_drop(inode);
1064 	ext4_discard_preallocations(inode);
1065 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1066 	if (EXT4_I(inode)->jinode) {
1067 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1068 					       EXT4_I(inode)->jinode);
1069 		jbd2_free_inode(EXT4_I(inode)->jinode);
1070 		EXT4_I(inode)->jinode = NULL;
1071 	}
1072 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1073 	fscrypt_put_encryption_info(inode, NULL);
1074 #endif
1075 }
1076 
1077 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1078 					u64 ino, u32 generation)
1079 {
1080 	struct inode *inode;
1081 
1082 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1083 		return ERR_PTR(-ESTALE);
1084 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1085 		return ERR_PTR(-ESTALE);
1086 
1087 	/* iget isn't really right if the inode is currently unallocated!!
1088 	 *
1089 	 * ext4_read_inode will return a bad_inode if the inode had been
1090 	 * deleted, so we should be safe.
1091 	 *
1092 	 * Currently we don't know the generation for parent directory, so
1093 	 * a generation of 0 means "accept any"
1094 	 */
1095 	inode = ext4_iget_normal(sb, ino);
1096 	if (IS_ERR(inode))
1097 		return ERR_CAST(inode);
1098 	if (generation && inode->i_generation != generation) {
1099 		iput(inode);
1100 		return ERR_PTR(-ESTALE);
1101 	}
1102 
1103 	return inode;
1104 }
1105 
1106 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1107 					int fh_len, int fh_type)
1108 {
1109 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1110 				    ext4_nfs_get_inode);
1111 }
1112 
1113 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1114 					int fh_len, int fh_type)
1115 {
1116 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1117 				    ext4_nfs_get_inode);
1118 }
1119 
1120 /*
1121  * Try to release metadata pages (indirect blocks, directories) which are
1122  * mapped via the block device.  Since these pages could have journal heads
1123  * which would prevent try_to_free_buffers() from freeing them, we must use
1124  * jbd2 layer's try_to_free_buffers() function to release them.
1125  */
1126 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1127 				 gfp_t wait)
1128 {
1129 	journal_t *journal = EXT4_SB(sb)->s_journal;
1130 
1131 	WARN_ON(PageChecked(page));
1132 	if (!page_has_buffers(page))
1133 		return 0;
1134 	if (journal)
1135 		return jbd2_journal_try_to_free_buffers(journal, page,
1136 						wait & ~__GFP_DIRECT_RECLAIM);
1137 	return try_to_free_buffers(page);
1138 }
1139 
1140 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1141 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1142 {
1143 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1144 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1145 }
1146 
1147 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1148 							void *fs_data)
1149 {
1150 	handle_t *handle = fs_data;
1151 	int res, res2, retries = 0;
1152 
1153 	res = ext4_convert_inline_data(inode);
1154 	if (res)
1155 		return res;
1156 
1157 	/*
1158 	 * If a journal handle was specified, then the encryption context is
1159 	 * being set on a new inode via inheritance and is part of a larger
1160 	 * transaction to create the inode.  Otherwise the encryption context is
1161 	 * being set on an existing inode in its own transaction.  Only in the
1162 	 * latter case should the "retry on ENOSPC" logic be used.
1163 	 */
1164 
1165 	if (handle) {
1166 		res = ext4_xattr_set_handle(handle, inode,
1167 					    EXT4_XATTR_INDEX_ENCRYPTION,
1168 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1169 					    ctx, len, 0);
1170 		if (!res) {
1171 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1172 			ext4_clear_inode_state(inode,
1173 					EXT4_STATE_MAY_INLINE_DATA);
1174 			/*
1175 			 * Update inode->i_flags - e.g. S_DAX may get disabled
1176 			 */
1177 			ext4_set_inode_flags(inode);
1178 		}
1179 		return res;
1180 	}
1181 
1182 retry:
1183 	handle = ext4_journal_start(inode, EXT4_HT_MISC,
1184 			ext4_jbd2_credits_xattr(inode));
1185 	if (IS_ERR(handle))
1186 		return PTR_ERR(handle);
1187 
1188 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1189 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1190 				    ctx, len, 0);
1191 	if (!res) {
1192 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1193 		/* Update inode->i_flags - e.g. S_DAX may get disabled */
1194 		ext4_set_inode_flags(inode);
1195 		res = ext4_mark_inode_dirty(handle, inode);
1196 		if (res)
1197 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1198 	}
1199 	res2 = ext4_journal_stop(handle);
1200 
1201 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1202 		goto retry;
1203 	if (!res)
1204 		res = res2;
1205 	return res;
1206 }
1207 
1208 static int ext4_dummy_context(struct inode *inode)
1209 {
1210 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1211 }
1212 
1213 static unsigned ext4_max_namelen(struct inode *inode)
1214 {
1215 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1216 		EXT4_NAME_LEN;
1217 }
1218 
1219 static const struct fscrypt_operations ext4_cryptops = {
1220 	.key_prefix		= "ext4:",
1221 	.get_context		= ext4_get_context,
1222 	.set_context		= ext4_set_context,
1223 	.dummy_context		= ext4_dummy_context,
1224 	.is_encrypted		= ext4_encrypted_inode,
1225 	.empty_dir		= ext4_empty_dir,
1226 	.max_namelen		= ext4_max_namelen,
1227 };
1228 #else
1229 static const struct fscrypt_operations ext4_cryptops = {
1230 	.is_encrypted		= ext4_encrypted_inode,
1231 };
1232 #endif
1233 
1234 #ifdef CONFIG_QUOTA
1235 static const char * const quotatypes[] = INITQFNAMES;
1236 #define QTYPE2NAME(t) (quotatypes[t])
1237 
1238 static int ext4_write_dquot(struct dquot *dquot);
1239 static int ext4_acquire_dquot(struct dquot *dquot);
1240 static int ext4_release_dquot(struct dquot *dquot);
1241 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1242 static int ext4_write_info(struct super_block *sb, int type);
1243 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1244 			 const struct path *path);
1245 static int ext4_quota_on_mount(struct super_block *sb, int type);
1246 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1247 			       size_t len, loff_t off);
1248 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1249 				const char *data, size_t len, loff_t off);
1250 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1251 			     unsigned int flags);
1252 static int ext4_enable_quotas(struct super_block *sb);
1253 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1254 
1255 static struct dquot **ext4_get_dquots(struct inode *inode)
1256 {
1257 	return EXT4_I(inode)->i_dquot;
1258 }
1259 
1260 static const struct dquot_operations ext4_quota_operations = {
1261 	.get_reserved_space = ext4_get_reserved_space,
1262 	.write_dquot	= ext4_write_dquot,
1263 	.acquire_dquot	= ext4_acquire_dquot,
1264 	.release_dquot	= ext4_release_dquot,
1265 	.mark_dirty	= ext4_mark_dquot_dirty,
1266 	.write_info	= ext4_write_info,
1267 	.alloc_dquot	= dquot_alloc,
1268 	.destroy_dquot	= dquot_destroy,
1269 	.get_projid	= ext4_get_projid,
1270 	.get_next_id	= ext4_get_next_id,
1271 };
1272 
1273 static const struct quotactl_ops ext4_qctl_operations = {
1274 	.quota_on	= ext4_quota_on,
1275 	.quota_off	= ext4_quota_off,
1276 	.quota_sync	= dquot_quota_sync,
1277 	.get_state	= dquot_get_state,
1278 	.set_info	= dquot_set_dqinfo,
1279 	.get_dqblk	= dquot_get_dqblk,
1280 	.set_dqblk	= dquot_set_dqblk,
1281 	.get_nextdqblk	= dquot_get_next_dqblk,
1282 };
1283 #endif
1284 
1285 static const struct super_operations ext4_sops = {
1286 	.alloc_inode	= ext4_alloc_inode,
1287 	.destroy_inode	= ext4_destroy_inode,
1288 	.write_inode	= ext4_write_inode,
1289 	.dirty_inode	= ext4_dirty_inode,
1290 	.drop_inode	= ext4_drop_inode,
1291 	.evict_inode	= ext4_evict_inode,
1292 	.put_super	= ext4_put_super,
1293 	.sync_fs	= ext4_sync_fs,
1294 	.freeze_fs	= ext4_freeze,
1295 	.unfreeze_fs	= ext4_unfreeze,
1296 	.statfs		= ext4_statfs,
1297 	.remount_fs	= ext4_remount,
1298 	.show_options	= ext4_show_options,
1299 #ifdef CONFIG_QUOTA
1300 	.quota_read	= ext4_quota_read,
1301 	.quota_write	= ext4_quota_write,
1302 	.get_dquots	= ext4_get_dquots,
1303 #endif
1304 	.bdev_try_to_free_page = bdev_try_to_free_page,
1305 };
1306 
1307 static const struct export_operations ext4_export_ops = {
1308 	.fh_to_dentry = ext4_fh_to_dentry,
1309 	.fh_to_parent = ext4_fh_to_parent,
1310 	.get_parent = ext4_get_parent,
1311 };
1312 
1313 enum {
1314 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1315 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1316 	Opt_nouid32, Opt_debug, Opt_removed,
1317 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1318 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1319 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1320 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1321 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1322 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1323 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1324 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1325 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1326 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1327 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1328 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1329 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1330 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1331 	Opt_dioread_nolock, Opt_dioread_lock,
1332 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1333 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1334 };
1335 
1336 static const match_table_t tokens = {
1337 	{Opt_bsd_df, "bsddf"},
1338 	{Opt_minix_df, "minixdf"},
1339 	{Opt_grpid, "grpid"},
1340 	{Opt_grpid, "bsdgroups"},
1341 	{Opt_nogrpid, "nogrpid"},
1342 	{Opt_nogrpid, "sysvgroups"},
1343 	{Opt_resgid, "resgid=%u"},
1344 	{Opt_resuid, "resuid=%u"},
1345 	{Opt_sb, "sb=%u"},
1346 	{Opt_err_cont, "errors=continue"},
1347 	{Opt_err_panic, "errors=panic"},
1348 	{Opt_err_ro, "errors=remount-ro"},
1349 	{Opt_nouid32, "nouid32"},
1350 	{Opt_debug, "debug"},
1351 	{Opt_removed, "oldalloc"},
1352 	{Opt_removed, "orlov"},
1353 	{Opt_user_xattr, "user_xattr"},
1354 	{Opt_nouser_xattr, "nouser_xattr"},
1355 	{Opt_acl, "acl"},
1356 	{Opt_noacl, "noacl"},
1357 	{Opt_noload, "norecovery"},
1358 	{Opt_noload, "noload"},
1359 	{Opt_removed, "nobh"},
1360 	{Opt_removed, "bh"},
1361 	{Opt_commit, "commit=%u"},
1362 	{Opt_min_batch_time, "min_batch_time=%u"},
1363 	{Opt_max_batch_time, "max_batch_time=%u"},
1364 	{Opt_journal_dev, "journal_dev=%u"},
1365 	{Opt_journal_path, "journal_path=%s"},
1366 	{Opt_journal_checksum, "journal_checksum"},
1367 	{Opt_nojournal_checksum, "nojournal_checksum"},
1368 	{Opt_journal_async_commit, "journal_async_commit"},
1369 	{Opt_abort, "abort"},
1370 	{Opt_data_journal, "data=journal"},
1371 	{Opt_data_ordered, "data=ordered"},
1372 	{Opt_data_writeback, "data=writeback"},
1373 	{Opt_data_err_abort, "data_err=abort"},
1374 	{Opt_data_err_ignore, "data_err=ignore"},
1375 	{Opt_offusrjquota, "usrjquota="},
1376 	{Opt_usrjquota, "usrjquota=%s"},
1377 	{Opt_offgrpjquota, "grpjquota="},
1378 	{Opt_grpjquota, "grpjquota=%s"},
1379 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1380 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1381 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1382 	{Opt_grpquota, "grpquota"},
1383 	{Opt_noquota, "noquota"},
1384 	{Opt_quota, "quota"},
1385 	{Opt_usrquota, "usrquota"},
1386 	{Opt_prjquota, "prjquota"},
1387 	{Opt_barrier, "barrier=%u"},
1388 	{Opt_barrier, "barrier"},
1389 	{Opt_nobarrier, "nobarrier"},
1390 	{Opt_i_version, "i_version"},
1391 	{Opt_dax, "dax"},
1392 	{Opt_stripe, "stripe=%u"},
1393 	{Opt_delalloc, "delalloc"},
1394 	{Opt_lazytime, "lazytime"},
1395 	{Opt_nolazytime, "nolazytime"},
1396 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1397 	{Opt_nodelalloc, "nodelalloc"},
1398 	{Opt_removed, "mblk_io_submit"},
1399 	{Opt_removed, "nomblk_io_submit"},
1400 	{Opt_block_validity, "block_validity"},
1401 	{Opt_noblock_validity, "noblock_validity"},
1402 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1403 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1404 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1405 	{Opt_auto_da_alloc, "auto_da_alloc"},
1406 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1407 	{Opt_dioread_nolock, "dioread_nolock"},
1408 	{Opt_dioread_lock, "dioread_lock"},
1409 	{Opt_discard, "discard"},
1410 	{Opt_nodiscard, "nodiscard"},
1411 	{Opt_init_itable, "init_itable=%u"},
1412 	{Opt_init_itable, "init_itable"},
1413 	{Opt_noinit_itable, "noinit_itable"},
1414 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1415 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1416 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1417 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1418 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1419 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1420 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1421 	{Opt_err, NULL},
1422 };
1423 
1424 static ext4_fsblk_t get_sb_block(void **data)
1425 {
1426 	ext4_fsblk_t	sb_block;
1427 	char		*options = (char *) *data;
1428 
1429 	if (!options || strncmp(options, "sb=", 3) != 0)
1430 		return 1;	/* Default location */
1431 
1432 	options += 3;
1433 	/* TODO: use simple_strtoll with >32bit ext4 */
1434 	sb_block = simple_strtoul(options, &options, 0);
1435 	if (*options && *options != ',') {
1436 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1437 		       (char *) *data);
1438 		return 1;
1439 	}
1440 	if (*options == ',')
1441 		options++;
1442 	*data = (void *) options;
1443 
1444 	return sb_block;
1445 }
1446 
1447 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1448 static const char deprecated_msg[] =
1449 	"Mount option \"%s\" will be removed by %s\n"
1450 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1451 
1452 #ifdef CONFIG_QUOTA
1453 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1454 {
1455 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1456 	char *qname;
1457 	int ret = -1;
1458 
1459 	if (sb_any_quota_loaded(sb) &&
1460 		!sbi->s_qf_names[qtype]) {
1461 		ext4_msg(sb, KERN_ERR,
1462 			"Cannot change journaled "
1463 			"quota options when quota turned on");
1464 		return -1;
1465 	}
1466 	if (ext4_has_feature_quota(sb)) {
1467 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1468 			 "ignored when QUOTA feature is enabled");
1469 		return 1;
1470 	}
1471 	qname = match_strdup(args);
1472 	if (!qname) {
1473 		ext4_msg(sb, KERN_ERR,
1474 			"Not enough memory for storing quotafile name");
1475 		return -1;
1476 	}
1477 	if (sbi->s_qf_names[qtype]) {
1478 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1479 			ret = 1;
1480 		else
1481 			ext4_msg(sb, KERN_ERR,
1482 				 "%s quota file already specified",
1483 				 QTYPE2NAME(qtype));
1484 		goto errout;
1485 	}
1486 	if (strchr(qname, '/')) {
1487 		ext4_msg(sb, KERN_ERR,
1488 			"quotafile must be on filesystem root");
1489 		goto errout;
1490 	}
1491 	sbi->s_qf_names[qtype] = qname;
1492 	set_opt(sb, QUOTA);
1493 	return 1;
1494 errout:
1495 	kfree(qname);
1496 	return ret;
1497 }
1498 
1499 static int clear_qf_name(struct super_block *sb, int qtype)
1500 {
1501 
1502 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1503 
1504 	if (sb_any_quota_loaded(sb) &&
1505 		sbi->s_qf_names[qtype]) {
1506 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1507 			" when quota turned on");
1508 		return -1;
1509 	}
1510 	kfree(sbi->s_qf_names[qtype]);
1511 	sbi->s_qf_names[qtype] = NULL;
1512 	return 1;
1513 }
1514 #endif
1515 
1516 #define MOPT_SET	0x0001
1517 #define MOPT_CLEAR	0x0002
1518 #define MOPT_NOSUPPORT	0x0004
1519 #define MOPT_EXPLICIT	0x0008
1520 #define MOPT_CLEAR_ERR	0x0010
1521 #define MOPT_GTE0	0x0020
1522 #ifdef CONFIG_QUOTA
1523 #define MOPT_Q		0
1524 #define MOPT_QFMT	0x0040
1525 #else
1526 #define MOPT_Q		MOPT_NOSUPPORT
1527 #define MOPT_QFMT	MOPT_NOSUPPORT
1528 #endif
1529 #define MOPT_DATAJ	0x0080
1530 #define MOPT_NO_EXT2	0x0100
1531 #define MOPT_NO_EXT3	0x0200
1532 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1533 #define MOPT_STRING	0x0400
1534 
1535 static const struct mount_opts {
1536 	int	token;
1537 	int	mount_opt;
1538 	int	flags;
1539 } ext4_mount_opts[] = {
1540 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1541 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1542 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1543 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1544 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1545 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1546 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1547 	 MOPT_EXT4_ONLY | MOPT_SET},
1548 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1549 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1550 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1551 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1552 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1553 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1554 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1555 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1556 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1557 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1558 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1559 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1560 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1561 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1562 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1563 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1564 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1565 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1566 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1567 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1568 	 MOPT_NO_EXT2},
1569 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1570 	 MOPT_NO_EXT2},
1571 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1572 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1573 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1574 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1575 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1576 	{Opt_commit, 0, MOPT_GTE0},
1577 	{Opt_max_batch_time, 0, MOPT_GTE0},
1578 	{Opt_min_batch_time, 0, MOPT_GTE0},
1579 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1580 	{Opt_init_itable, 0, MOPT_GTE0},
1581 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1582 	{Opt_stripe, 0, MOPT_GTE0},
1583 	{Opt_resuid, 0, MOPT_GTE0},
1584 	{Opt_resgid, 0, MOPT_GTE0},
1585 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1586 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1587 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1588 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1589 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1590 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1591 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1592 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1593 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1594 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1595 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1596 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1597 #else
1598 	{Opt_acl, 0, MOPT_NOSUPPORT},
1599 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1600 #endif
1601 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1602 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1603 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1604 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1605 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1606 							MOPT_SET | MOPT_Q},
1607 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1608 							MOPT_SET | MOPT_Q},
1609 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1610 							MOPT_SET | MOPT_Q},
1611 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1612 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1613 							MOPT_CLEAR | MOPT_Q},
1614 	{Opt_usrjquota, 0, MOPT_Q},
1615 	{Opt_grpjquota, 0, MOPT_Q},
1616 	{Opt_offusrjquota, 0, MOPT_Q},
1617 	{Opt_offgrpjquota, 0, MOPT_Q},
1618 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1619 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1620 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1621 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1622 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1623 	{Opt_err, 0, 0}
1624 };
1625 
1626 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1627 			    substring_t *args, unsigned long *journal_devnum,
1628 			    unsigned int *journal_ioprio, int is_remount)
1629 {
1630 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1631 	const struct mount_opts *m;
1632 	kuid_t uid;
1633 	kgid_t gid;
1634 	int arg = 0;
1635 
1636 #ifdef CONFIG_QUOTA
1637 	if (token == Opt_usrjquota)
1638 		return set_qf_name(sb, USRQUOTA, &args[0]);
1639 	else if (token == Opt_grpjquota)
1640 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1641 	else if (token == Opt_offusrjquota)
1642 		return clear_qf_name(sb, USRQUOTA);
1643 	else if (token == Opt_offgrpjquota)
1644 		return clear_qf_name(sb, GRPQUOTA);
1645 #endif
1646 	switch (token) {
1647 	case Opt_noacl:
1648 	case Opt_nouser_xattr:
1649 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1650 		break;
1651 	case Opt_sb:
1652 		return 1;	/* handled by get_sb_block() */
1653 	case Opt_removed:
1654 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1655 		return 1;
1656 	case Opt_abort:
1657 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1658 		return 1;
1659 	case Opt_i_version:
1660 		sb->s_flags |= MS_I_VERSION;
1661 		return 1;
1662 	case Opt_lazytime:
1663 		sb->s_flags |= MS_LAZYTIME;
1664 		return 1;
1665 	case Opt_nolazytime:
1666 		sb->s_flags &= ~MS_LAZYTIME;
1667 		return 1;
1668 	}
1669 
1670 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1671 		if (token == m->token)
1672 			break;
1673 
1674 	if (m->token == Opt_err) {
1675 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1676 			 "or missing value", opt);
1677 		return -1;
1678 	}
1679 
1680 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1681 		ext4_msg(sb, KERN_ERR,
1682 			 "Mount option \"%s\" incompatible with ext2", opt);
1683 		return -1;
1684 	}
1685 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1686 		ext4_msg(sb, KERN_ERR,
1687 			 "Mount option \"%s\" incompatible with ext3", opt);
1688 		return -1;
1689 	}
1690 
1691 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1692 		return -1;
1693 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1694 		return -1;
1695 	if (m->flags & MOPT_EXPLICIT) {
1696 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1697 			set_opt2(sb, EXPLICIT_DELALLOC);
1698 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1699 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1700 		} else
1701 			return -1;
1702 	}
1703 	if (m->flags & MOPT_CLEAR_ERR)
1704 		clear_opt(sb, ERRORS_MASK);
1705 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1706 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1707 			 "options when quota turned on");
1708 		return -1;
1709 	}
1710 
1711 	if (m->flags & MOPT_NOSUPPORT) {
1712 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1713 	} else if (token == Opt_commit) {
1714 		if (arg == 0)
1715 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1716 		sbi->s_commit_interval = HZ * arg;
1717 	} else if (token == Opt_debug_want_extra_isize) {
1718 		sbi->s_want_extra_isize = arg;
1719 	} else if (token == Opt_max_batch_time) {
1720 		sbi->s_max_batch_time = arg;
1721 	} else if (token == Opt_min_batch_time) {
1722 		sbi->s_min_batch_time = arg;
1723 	} else if (token == Opt_inode_readahead_blks) {
1724 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1725 			ext4_msg(sb, KERN_ERR,
1726 				 "EXT4-fs: inode_readahead_blks must be "
1727 				 "0 or a power of 2 smaller than 2^31");
1728 			return -1;
1729 		}
1730 		sbi->s_inode_readahead_blks = arg;
1731 	} else if (token == Opt_init_itable) {
1732 		set_opt(sb, INIT_INODE_TABLE);
1733 		if (!args->from)
1734 			arg = EXT4_DEF_LI_WAIT_MULT;
1735 		sbi->s_li_wait_mult = arg;
1736 	} else if (token == Opt_max_dir_size_kb) {
1737 		sbi->s_max_dir_size_kb = arg;
1738 	} else if (token == Opt_stripe) {
1739 		sbi->s_stripe = arg;
1740 	} else if (token == Opt_resuid) {
1741 		uid = make_kuid(current_user_ns(), arg);
1742 		if (!uid_valid(uid)) {
1743 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1744 			return -1;
1745 		}
1746 		sbi->s_resuid = uid;
1747 	} else if (token == Opt_resgid) {
1748 		gid = make_kgid(current_user_ns(), arg);
1749 		if (!gid_valid(gid)) {
1750 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1751 			return -1;
1752 		}
1753 		sbi->s_resgid = gid;
1754 	} else if (token == Opt_journal_dev) {
1755 		if (is_remount) {
1756 			ext4_msg(sb, KERN_ERR,
1757 				 "Cannot specify journal on remount");
1758 			return -1;
1759 		}
1760 		*journal_devnum = arg;
1761 	} else if (token == Opt_journal_path) {
1762 		char *journal_path;
1763 		struct inode *journal_inode;
1764 		struct path path;
1765 		int error;
1766 
1767 		if (is_remount) {
1768 			ext4_msg(sb, KERN_ERR,
1769 				 "Cannot specify journal on remount");
1770 			return -1;
1771 		}
1772 		journal_path = match_strdup(&args[0]);
1773 		if (!journal_path) {
1774 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1775 				"journal device string");
1776 			return -1;
1777 		}
1778 
1779 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1780 		if (error) {
1781 			ext4_msg(sb, KERN_ERR, "error: could not find "
1782 				"journal device path: error %d", error);
1783 			kfree(journal_path);
1784 			return -1;
1785 		}
1786 
1787 		journal_inode = d_inode(path.dentry);
1788 		if (!S_ISBLK(journal_inode->i_mode)) {
1789 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1790 				"is not a block device", journal_path);
1791 			path_put(&path);
1792 			kfree(journal_path);
1793 			return -1;
1794 		}
1795 
1796 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1797 		path_put(&path);
1798 		kfree(journal_path);
1799 	} else if (token == Opt_journal_ioprio) {
1800 		if (arg > 7) {
1801 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1802 				 " (must be 0-7)");
1803 			return -1;
1804 		}
1805 		*journal_ioprio =
1806 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1807 	} else if (token == Opt_test_dummy_encryption) {
1808 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1809 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1810 		ext4_msg(sb, KERN_WARNING,
1811 			 "Test dummy encryption mode enabled");
1812 #else
1813 		ext4_msg(sb, KERN_WARNING,
1814 			 "Test dummy encryption mount option ignored");
1815 #endif
1816 	} else if (m->flags & MOPT_DATAJ) {
1817 		if (is_remount) {
1818 			if (!sbi->s_journal)
1819 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1820 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1821 				ext4_msg(sb, KERN_ERR,
1822 					 "Cannot change data mode on remount");
1823 				return -1;
1824 			}
1825 		} else {
1826 			clear_opt(sb, DATA_FLAGS);
1827 			sbi->s_mount_opt |= m->mount_opt;
1828 		}
1829 #ifdef CONFIG_QUOTA
1830 	} else if (m->flags & MOPT_QFMT) {
1831 		if (sb_any_quota_loaded(sb) &&
1832 		    sbi->s_jquota_fmt != m->mount_opt) {
1833 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1834 				 "quota options when quota turned on");
1835 			return -1;
1836 		}
1837 		if (ext4_has_feature_quota(sb)) {
1838 			ext4_msg(sb, KERN_INFO,
1839 				 "Quota format mount options ignored "
1840 				 "when QUOTA feature is enabled");
1841 			return 1;
1842 		}
1843 		sbi->s_jquota_fmt = m->mount_opt;
1844 #endif
1845 	} else if (token == Opt_dax) {
1846 #ifdef CONFIG_FS_DAX
1847 		ext4_msg(sb, KERN_WARNING,
1848 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1849 			sbi->s_mount_opt |= m->mount_opt;
1850 #else
1851 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1852 		return -1;
1853 #endif
1854 	} else if (token == Opt_data_err_abort) {
1855 		sbi->s_mount_opt |= m->mount_opt;
1856 	} else if (token == Opt_data_err_ignore) {
1857 		sbi->s_mount_opt &= ~m->mount_opt;
1858 	} else {
1859 		if (!args->from)
1860 			arg = 1;
1861 		if (m->flags & MOPT_CLEAR)
1862 			arg = !arg;
1863 		else if (unlikely(!(m->flags & MOPT_SET))) {
1864 			ext4_msg(sb, KERN_WARNING,
1865 				 "buggy handling of option %s", opt);
1866 			WARN_ON(1);
1867 			return -1;
1868 		}
1869 		if (arg != 0)
1870 			sbi->s_mount_opt |= m->mount_opt;
1871 		else
1872 			sbi->s_mount_opt &= ~m->mount_opt;
1873 	}
1874 	return 1;
1875 }
1876 
1877 static int parse_options(char *options, struct super_block *sb,
1878 			 unsigned long *journal_devnum,
1879 			 unsigned int *journal_ioprio,
1880 			 int is_remount)
1881 {
1882 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1883 	char *p;
1884 	substring_t args[MAX_OPT_ARGS];
1885 	int token;
1886 
1887 	if (!options)
1888 		return 1;
1889 
1890 	while ((p = strsep(&options, ",")) != NULL) {
1891 		if (!*p)
1892 			continue;
1893 		/*
1894 		 * Initialize args struct so we know whether arg was
1895 		 * found; some options take optional arguments.
1896 		 */
1897 		args[0].to = args[0].from = NULL;
1898 		token = match_token(p, tokens, args);
1899 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1900 				     journal_ioprio, is_remount) < 0)
1901 			return 0;
1902 	}
1903 #ifdef CONFIG_QUOTA
1904 	/*
1905 	 * We do the test below only for project quotas. 'usrquota' and
1906 	 * 'grpquota' mount options are allowed even without quota feature
1907 	 * to support legacy quotas in quota files.
1908 	 */
1909 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1910 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1911 			 "Cannot enable project quota enforcement.");
1912 		return 0;
1913 	}
1914 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1915 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1916 			clear_opt(sb, USRQUOTA);
1917 
1918 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1919 			clear_opt(sb, GRPQUOTA);
1920 
1921 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1922 			ext4_msg(sb, KERN_ERR, "old and new quota "
1923 					"format mixing");
1924 			return 0;
1925 		}
1926 
1927 		if (!sbi->s_jquota_fmt) {
1928 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1929 					"not specified");
1930 			return 0;
1931 		}
1932 	}
1933 #endif
1934 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1935 		int blocksize =
1936 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1937 
1938 		if (blocksize < PAGE_SIZE) {
1939 			ext4_msg(sb, KERN_ERR, "can't mount with "
1940 				 "dioread_nolock if block size != PAGE_SIZE");
1941 			return 0;
1942 		}
1943 	}
1944 	return 1;
1945 }
1946 
1947 static inline void ext4_show_quota_options(struct seq_file *seq,
1948 					   struct super_block *sb)
1949 {
1950 #if defined(CONFIG_QUOTA)
1951 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1952 
1953 	if (sbi->s_jquota_fmt) {
1954 		char *fmtname = "";
1955 
1956 		switch (sbi->s_jquota_fmt) {
1957 		case QFMT_VFS_OLD:
1958 			fmtname = "vfsold";
1959 			break;
1960 		case QFMT_VFS_V0:
1961 			fmtname = "vfsv0";
1962 			break;
1963 		case QFMT_VFS_V1:
1964 			fmtname = "vfsv1";
1965 			break;
1966 		}
1967 		seq_printf(seq, ",jqfmt=%s", fmtname);
1968 	}
1969 
1970 	if (sbi->s_qf_names[USRQUOTA])
1971 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1972 
1973 	if (sbi->s_qf_names[GRPQUOTA])
1974 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1975 #endif
1976 }
1977 
1978 static const char *token2str(int token)
1979 {
1980 	const struct match_token *t;
1981 
1982 	for (t = tokens; t->token != Opt_err; t++)
1983 		if (t->token == token && !strchr(t->pattern, '='))
1984 			break;
1985 	return t->pattern;
1986 }
1987 
1988 /*
1989  * Show an option if
1990  *  - it's set to a non-default value OR
1991  *  - if the per-sb default is different from the global default
1992  */
1993 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1994 			      int nodefs)
1995 {
1996 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1997 	struct ext4_super_block *es = sbi->s_es;
1998 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1999 	const struct mount_opts *m;
2000 	char sep = nodefs ? '\n' : ',';
2001 
2002 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2003 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2004 
2005 	if (sbi->s_sb_block != 1)
2006 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2007 
2008 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2009 		int want_set = m->flags & MOPT_SET;
2010 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2011 		    (m->flags & MOPT_CLEAR_ERR))
2012 			continue;
2013 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2014 			continue; /* skip if same as the default */
2015 		if ((want_set &&
2016 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2017 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2018 			continue; /* select Opt_noFoo vs Opt_Foo */
2019 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2020 	}
2021 
2022 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2023 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2024 		SEQ_OPTS_PRINT("resuid=%u",
2025 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2026 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2027 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2028 		SEQ_OPTS_PRINT("resgid=%u",
2029 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2030 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2031 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2032 		SEQ_OPTS_PUTS("errors=remount-ro");
2033 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2034 		SEQ_OPTS_PUTS("errors=continue");
2035 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2036 		SEQ_OPTS_PUTS("errors=panic");
2037 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2038 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2039 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2040 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2041 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2042 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2043 	if (sb->s_flags & MS_I_VERSION)
2044 		SEQ_OPTS_PUTS("i_version");
2045 	if (nodefs || sbi->s_stripe)
2046 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2047 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2048 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2049 			SEQ_OPTS_PUTS("data=journal");
2050 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2051 			SEQ_OPTS_PUTS("data=ordered");
2052 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2053 			SEQ_OPTS_PUTS("data=writeback");
2054 	}
2055 	if (nodefs ||
2056 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2057 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2058 			       sbi->s_inode_readahead_blks);
2059 
2060 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2061 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2062 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2063 	if (nodefs || sbi->s_max_dir_size_kb)
2064 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2065 	if (test_opt(sb, DATA_ERR_ABORT))
2066 		SEQ_OPTS_PUTS("data_err=abort");
2067 
2068 	ext4_show_quota_options(seq, sb);
2069 	return 0;
2070 }
2071 
2072 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2073 {
2074 	return _ext4_show_options(seq, root->d_sb, 0);
2075 }
2076 
2077 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2078 {
2079 	struct super_block *sb = seq->private;
2080 	int rc;
2081 
2082 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2083 	rc = _ext4_show_options(seq, sb, 1);
2084 	seq_puts(seq, "\n");
2085 	return rc;
2086 }
2087 
2088 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2089 			    int read_only)
2090 {
2091 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2092 	int res = 0;
2093 
2094 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2095 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2096 			 "forcing read-only mode");
2097 		res = MS_RDONLY;
2098 	}
2099 	if (read_only)
2100 		goto done;
2101 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2102 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2103 			 "running e2fsck is recommended");
2104 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2105 		ext4_msg(sb, KERN_WARNING,
2106 			 "warning: mounting fs with errors, "
2107 			 "running e2fsck is recommended");
2108 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2109 		 le16_to_cpu(es->s_mnt_count) >=
2110 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2111 		ext4_msg(sb, KERN_WARNING,
2112 			 "warning: maximal mount count reached, "
2113 			 "running e2fsck is recommended");
2114 	else if (le32_to_cpu(es->s_checkinterval) &&
2115 		(le32_to_cpu(es->s_lastcheck) +
2116 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2117 		ext4_msg(sb, KERN_WARNING,
2118 			 "warning: checktime reached, "
2119 			 "running e2fsck is recommended");
2120 	if (!sbi->s_journal)
2121 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2122 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2123 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2124 	le16_add_cpu(&es->s_mnt_count, 1);
2125 	es->s_mtime = cpu_to_le32(get_seconds());
2126 	ext4_update_dynamic_rev(sb);
2127 	if (sbi->s_journal)
2128 		ext4_set_feature_journal_needs_recovery(sb);
2129 
2130 	ext4_commit_super(sb, 1);
2131 done:
2132 	if (test_opt(sb, DEBUG))
2133 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2134 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2135 			sb->s_blocksize,
2136 			sbi->s_groups_count,
2137 			EXT4_BLOCKS_PER_GROUP(sb),
2138 			EXT4_INODES_PER_GROUP(sb),
2139 			sbi->s_mount_opt, sbi->s_mount_opt2);
2140 
2141 	cleancache_init_fs(sb);
2142 	return res;
2143 }
2144 
2145 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2146 {
2147 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2148 	struct flex_groups *new_groups;
2149 	int size;
2150 
2151 	if (!sbi->s_log_groups_per_flex)
2152 		return 0;
2153 
2154 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2155 	if (size <= sbi->s_flex_groups_allocated)
2156 		return 0;
2157 
2158 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2159 	new_groups = kvzalloc(size, GFP_KERNEL);
2160 	if (!new_groups) {
2161 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2162 			 size / (int) sizeof(struct flex_groups));
2163 		return -ENOMEM;
2164 	}
2165 
2166 	if (sbi->s_flex_groups) {
2167 		memcpy(new_groups, sbi->s_flex_groups,
2168 		       (sbi->s_flex_groups_allocated *
2169 			sizeof(struct flex_groups)));
2170 		kvfree(sbi->s_flex_groups);
2171 	}
2172 	sbi->s_flex_groups = new_groups;
2173 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2174 	return 0;
2175 }
2176 
2177 static int ext4_fill_flex_info(struct super_block *sb)
2178 {
2179 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2180 	struct ext4_group_desc *gdp = NULL;
2181 	ext4_group_t flex_group;
2182 	int i, err;
2183 
2184 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2185 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2186 		sbi->s_log_groups_per_flex = 0;
2187 		return 1;
2188 	}
2189 
2190 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2191 	if (err)
2192 		goto failed;
2193 
2194 	for (i = 0; i < sbi->s_groups_count; i++) {
2195 		gdp = ext4_get_group_desc(sb, i, NULL);
2196 
2197 		flex_group = ext4_flex_group(sbi, i);
2198 		atomic_add(ext4_free_inodes_count(sb, gdp),
2199 			   &sbi->s_flex_groups[flex_group].free_inodes);
2200 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2201 			     &sbi->s_flex_groups[flex_group].free_clusters);
2202 		atomic_add(ext4_used_dirs_count(sb, gdp),
2203 			   &sbi->s_flex_groups[flex_group].used_dirs);
2204 	}
2205 
2206 	return 1;
2207 failed:
2208 	return 0;
2209 }
2210 
2211 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2212 				   struct ext4_group_desc *gdp)
2213 {
2214 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2215 	__u16 crc = 0;
2216 	__le32 le_group = cpu_to_le32(block_group);
2217 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2218 
2219 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2220 		/* Use new metadata_csum algorithm */
2221 		__u32 csum32;
2222 		__u16 dummy_csum = 0;
2223 
2224 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2225 				     sizeof(le_group));
2226 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2227 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2228 				     sizeof(dummy_csum));
2229 		offset += sizeof(dummy_csum);
2230 		if (offset < sbi->s_desc_size)
2231 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2232 					     sbi->s_desc_size - offset);
2233 
2234 		crc = csum32 & 0xFFFF;
2235 		goto out;
2236 	}
2237 
2238 	/* old crc16 code */
2239 	if (!ext4_has_feature_gdt_csum(sb))
2240 		return 0;
2241 
2242 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2243 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2244 	crc = crc16(crc, (__u8 *)gdp, offset);
2245 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2246 	/* for checksum of struct ext4_group_desc do the rest...*/
2247 	if (ext4_has_feature_64bit(sb) &&
2248 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2249 		crc = crc16(crc, (__u8 *)gdp + offset,
2250 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2251 				offset);
2252 
2253 out:
2254 	return cpu_to_le16(crc);
2255 }
2256 
2257 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2258 				struct ext4_group_desc *gdp)
2259 {
2260 	if (ext4_has_group_desc_csum(sb) &&
2261 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2262 		return 0;
2263 
2264 	return 1;
2265 }
2266 
2267 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2268 			      struct ext4_group_desc *gdp)
2269 {
2270 	if (!ext4_has_group_desc_csum(sb))
2271 		return;
2272 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2273 }
2274 
2275 /* Called at mount-time, super-block is locked */
2276 static int ext4_check_descriptors(struct super_block *sb,
2277 				  ext4_fsblk_t sb_block,
2278 				  ext4_group_t *first_not_zeroed)
2279 {
2280 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2281 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2282 	ext4_fsblk_t last_block;
2283 	ext4_fsblk_t block_bitmap;
2284 	ext4_fsblk_t inode_bitmap;
2285 	ext4_fsblk_t inode_table;
2286 	int flexbg_flag = 0;
2287 	ext4_group_t i, grp = sbi->s_groups_count;
2288 
2289 	if (ext4_has_feature_flex_bg(sb))
2290 		flexbg_flag = 1;
2291 
2292 	ext4_debug("Checking group descriptors");
2293 
2294 	for (i = 0; i < sbi->s_groups_count; i++) {
2295 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2296 
2297 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2298 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2299 		else
2300 			last_block = first_block +
2301 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2302 
2303 		if ((grp == sbi->s_groups_count) &&
2304 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2305 			grp = i;
2306 
2307 		block_bitmap = ext4_block_bitmap(sb, gdp);
2308 		if (block_bitmap == sb_block) {
2309 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2310 				 "Block bitmap for group %u overlaps "
2311 				 "superblock", i);
2312 		}
2313 		if (block_bitmap < first_block || block_bitmap > last_block) {
2314 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2315 			       "Block bitmap for group %u not in group "
2316 			       "(block %llu)!", i, block_bitmap);
2317 			return 0;
2318 		}
2319 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2320 		if (inode_bitmap == sb_block) {
2321 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2322 				 "Inode bitmap for group %u overlaps "
2323 				 "superblock", i);
2324 		}
2325 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2326 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2327 			       "Inode bitmap for group %u not in group "
2328 			       "(block %llu)!", i, inode_bitmap);
2329 			return 0;
2330 		}
2331 		inode_table = ext4_inode_table(sb, gdp);
2332 		if (inode_table == sb_block) {
2333 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2334 				 "Inode table for group %u overlaps "
2335 				 "superblock", i);
2336 		}
2337 		if (inode_table < first_block ||
2338 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2339 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2340 			       "Inode table for group %u not in group "
2341 			       "(block %llu)!", i, inode_table);
2342 			return 0;
2343 		}
2344 		ext4_lock_group(sb, i);
2345 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2346 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2347 				 "Checksum for group %u failed (%u!=%u)",
2348 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2349 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2350 			if (!(sb->s_flags & MS_RDONLY)) {
2351 				ext4_unlock_group(sb, i);
2352 				return 0;
2353 			}
2354 		}
2355 		ext4_unlock_group(sb, i);
2356 		if (!flexbg_flag)
2357 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2358 	}
2359 	if (NULL != first_not_zeroed)
2360 		*first_not_zeroed = grp;
2361 	return 1;
2362 }
2363 
2364 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2365  * the superblock) which were deleted from all directories, but held open by
2366  * a process at the time of a crash.  We walk the list and try to delete these
2367  * inodes at recovery time (only with a read-write filesystem).
2368  *
2369  * In order to keep the orphan inode chain consistent during traversal (in
2370  * case of crash during recovery), we link each inode into the superblock
2371  * orphan list_head and handle it the same way as an inode deletion during
2372  * normal operation (which journals the operations for us).
2373  *
2374  * We only do an iget() and an iput() on each inode, which is very safe if we
2375  * accidentally point at an in-use or already deleted inode.  The worst that
2376  * can happen in this case is that we get a "bit already cleared" message from
2377  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2378  * e2fsck was run on this filesystem, and it must have already done the orphan
2379  * inode cleanup for us, so we can safely abort without any further action.
2380  */
2381 static void ext4_orphan_cleanup(struct super_block *sb,
2382 				struct ext4_super_block *es)
2383 {
2384 	unsigned int s_flags = sb->s_flags;
2385 	int ret, nr_orphans = 0, nr_truncates = 0;
2386 #ifdef CONFIG_QUOTA
2387 	int i;
2388 #endif
2389 	if (!es->s_last_orphan) {
2390 		jbd_debug(4, "no orphan inodes to clean up\n");
2391 		return;
2392 	}
2393 
2394 	if (bdev_read_only(sb->s_bdev)) {
2395 		ext4_msg(sb, KERN_ERR, "write access "
2396 			"unavailable, skipping orphan cleanup");
2397 		return;
2398 	}
2399 
2400 	/* Check if feature set would not allow a r/w mount */
2401 	if (!ext4_feature_set_ok(sb, 0)) {
2402 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2403 			 "unknown ROCOMPAT features");
2404 		return;
2405 	}
2406 
2407 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2408 		/* don't clear list on RO mount w/ errors */
2409 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2410 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2411 				  "clearing orphan list.\n");
2412 			es->s_last_orphan = 0;
2413 		}
2414 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2415 		return;
2416 	}
2417 
2418 	if (s_flags & MS_RDONLY) {
2419 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2420 		sb->s_flags &= ~MS_RDONLY;
2421 	}
2422 #ifdef CONFIG_QUOTA
2423 	/* Needed for iput() to work correctly and not trash data */
2424 	sb->s_flags |= MS_ACTIVE;
2425 	/* Turn on quotas so that they are updated correctly */
2426 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2427 		if (EXT4_SB(sb)->s_qf_names[i]) {
2428 			int ret = ext4_quota_on_mount(sb, i);
2429 			if (ret < 0)
2430 				ext4_msg(sb, KERN_ERR,
2431 					"Cannot turn on journaled "
2432 					"quota: error %d", ret);
2433 		}
2434 	}
2435 #endif
2436 
2437 	while (es->s_last_orphan) {
2438 		struct inode *inode;
2439 
2440 		/*
2441 		 * We may have encountered an error during cleanup; if
2442 		 * so, skip the rest.
2443 		 */
2444 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2445 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2446 			es->s_last_orphan = 0;
2447 			break;
2448 		}
2449 
2450 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2451 		if (IS_ERR(inode)) {
2452 			es->s_last_orphan = 0;
2453 			break;
2454 		}
2455 
2456 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2457 		dquot_initialize(inode);
2458 		if (inode->i_nlink) {
2459 			if (test_opt(sb, DEBUG))
2460 				ext4_msg(sb, KERN_DEBUG,
2461 					"%s: truncating inode %lu to %lld bytes",
2462 					__func__, inode->i_ino, inode->i_size);
2463 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2464 				  inode->i_ino, inode->i_size);
2465 			inode_lock(inode);
2466 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2467 			ret = ext4_truncate(inode);
2468 			if (ret)
2469 				ext4_std_error(inode->i_sb, ret);
2470 			inode_unlock(inode);
2471 			nr_truncates++;
2472 		} else {
2473 			if (test_opt(sb, DEBUG))
2474 				ext4_msg(sb, KERN_DEBUG,
2475 					"%s: deleting unreferenced inode %lu",
2476 					__func__, inode->i_ino);
2477 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2478 				  inode->i_ino);
2479 			nr_orphans++;
2480 		}
2481 		iput(inode);  /* The delete magic happens here! */
2482 	}
2483 
2484 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2485 
2486 	if (nr_orphans)
2487 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2488 		       PLURAL(nr_orphans));
2489 	if (nr_truncates)
2490 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2491 		       PLURAL(nr_truncates));
2492 #ifdef CONFIG_QUOTA
2493 	/* Turn quotas off */
2494 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2495 		if (sb_dqopt(sb)->files[i])
2496 			dquot_quota_off(sb, i);
2497 	}
2498 #endif
2499 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2500 }
2501 
2502 /*
2503  * Maximal extent format file size.
2504  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2505  * extent format containers, within a sector_t, and within i_blocks
2506  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2507  * so that won't be a limiting factor.
2508  *
2509  * However there is other limiting factor. We do store extents in the form
2510  * of starting block and length, hence the resulting length of the extent
2511  * covering maximum file size must fit into on-disk format containers as
2512  * well. Given that length is always by 1 unit bigger than max unit (because
2513  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2514  *
2515  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2516  */
2517 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2518 {
2519 	loff_t res;
2520 	loff_t upper_limit = MAX_LFS_FILESIZE;
2521 
2522 	/* small i_blocks in vfs inode? */
2523 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2524 		/*
2525 		 * CONFIG_LBDAF is not enabled implies the inode
2526 		 * i_block represent total blocks in 512 bytes
2527 		 * 32 == size of vfs inode i_blocks * 8
2528 		 */
2529 		upper_limit = (1LL << 32) - 1;
2530 
2531 		/* total blocks in file system block size */
2532 		upper_limit >>= (blkbits - 9);
2533 		upper_limit <<= blkbits;
2534 	}
2535 
2536 	/*
2537 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2538 	 * by one fs block, so ee_len can cover the extent of maximum file
2539 	 * size
2540 	 */
2541 	res = (1LL << 32) - 1;
2542 	res <<= blkbits;
2543 
2544 	/* Sanity check against vm- & vfs- imposed limits */
2545 	if (res > upper_limit)
2546 		res = upper_limit;
2547 
2548 	return res;
2549 }
2550 
2551 /*
2552  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2553  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2554  * We need to be 1 filesystem block less than the 2^48 sector limit.
2555  */
2556 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2557 {
2558 	loff_t res = EXT4_NDIR_BLOCKS;
2559 	int meta_blocks;
2560 	loff_t upper_limit;
2561 	/* This is calculated to be the largest file size for a dense, block
2562 	 * mapped file such that the file's total number of 512-byte sectors,
2563 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2564 	 *
2565 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2566 	 * number of 512-byte sectors of the file.
2567 	 */
2568 
2569 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2570 		/*
2571 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2572 		 * the inode i_block field represents total file blocks in
2573 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2574 		 */
2575 		upper_limit = (1LL << 32) - 1;
2576 
2577 		/* total blocks in file system block size */
2578 		upper_limit >>= (bits - 9);
2579 
2580 	} else {
2581 		/*
2582 		 * We use 48 bit ext4_inode i_blocks
2583 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2584 		 * represent total number of blocks in
2585 		 * file system block size
2586 		 */
2587 		upper_limit = (1LL << 48) - 1;
2588 
2589 	}
2590 
2591 	/* indirect blocks */
2592 	meta_blocks = 1;
2593 	/* double indirect blocks */
2594 	meta_blocks += 1 + (1LL << (bits-2));
2595 	/* tripple indirect blocks */
2596 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2597 
2598 	upper_limit -= meta_blocks;
2599 	upper_limit <<= bits;
2600 
2601 	res += 1LL << (bits-2);
2602 	res += 1LL << (2*(bits-2));
2603 	res += 1LL << (3*(bits-2));
2604 	res <<= bits;
2605 	if (res > upper_limit)
2606 		res = upper_limit;
2607 
2608 	if (res > MAX_LFS_FILESIZE)
2609 		res = MAX_LFS_FILESIZE;
2610 
2611 	return res;
2612 }
2613 
2614 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2615 				   ext4_fsblk_t logical_sb_block, int nr)
2616 {
2617 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2618 	ext4_group_t bg, first_meta_bg;
2619 	int has_super = 0;
2620 
2621 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2622 
2623 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2624 		return logical_sb_block + nr + 1;
2625 	bg = sbi->s_desc_per_block * nr;
2626 	if (ext4_bg_has_super(sb, bg))
2627 		has_super = 1;
2628 
2629 	/*
2630 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2631 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2632 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2633 	 * compensate.
2634 	 */
2635 	if (sb->s_blocksize == 1024 && nr == 0 &&
2636 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2637 		has_super++;
2638 
2639 	return (has_super + ext4_group_first_block_no(sb, bg));
2640 }
2641 
2642 /**
2643  * ext4_get_stripe_size: Get the stripe size.
2644  * @sbi: In memory super block info
2645  *
2646  * If we have specified it via mount option, then
2647  * use the mount option value. If the value specified at mount time is
2648  * greater than the blocks per group use the super block value.
2649  * If the super block value is greater than blocks per group return 0.
2650  * Allocator needs it be less than blocks per group.
2651  *
2652  */
2653 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2654 {
2655 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2656 	unsigned long stripe_width =
2657 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2658 	int ret;
2659 
2660 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2661 		ret = sbi->s_stripe;
2662 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2663 		ret = stripe_width;
2664 	else if (stride && stride <= sbi->s_blocks_per_group)
2665 		ret = stride;
2666 	else
2667 		ret = 0;
2668 
2669 	/*
2670 	 * If the stripe width is 1, this makes no sense and
2671 	 * we set it to 0 to turn off stripe handling code.
2672 	 */
2673 	if (ret <= 1)
2674 		ret = 0;
2675 
2676 	return ret;
2677 }
2678 
2679 /*
2680  * Check whether this filesystem can be mounted based on
2681  * the features present and the RDONLY/RDWR mount requested.
2682  * Returns 1 if this filesystem can be mounted as requested,
2683  * 0 if it cannot be.
2684  */
2685 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2686 {
2687 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2688 		ext4_msg(sb, KERN_ERR,
2689 			"Couldn't mount because of "
2690 			"unsupported optional features (%x)",
2691 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2692 			~EXT4_FEATURE_INCOMPAT_SUPP));
2693 		return 0;
2694 	}
2695 
2696 	if (readonly)
2697 		return 1;
2698 
2699 	if (ext4_has_feature_readonly(sb)) {
2700 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2701 		sb->s_flags |= MS_RDONLY;
2702 		return 1;
2703 	}
2704 
2705 	/* Check that feature set is OK for a read-write mount */
2706 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2707 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2708 			 "unsupported optional features (%x)",
2709 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2710 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2711 		return 0;
2712 	}
2713 	/*
2714 	 * Large file size enabled file system can only be mounted
2715 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2716 	 */
2717 	if (ext4_has_feature_huge_file(sb)) {
2718 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2719 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2720 				 "cannot be mounted RDWR without "
2721 				 "CONFIG_LBDAF");
2722 			return 0;
2723 		}
2724 	}
2725 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2726 		ext4_msg(sb, KERN_ERR,
2727 			 "Can't support bigalloc feature without "
2728 			 "extents feature\n");
2729 		return 0;
2730 	}
2731 
2732 #ifndef CONFIG_QUOTA
2733 	if (ext4_has_feature_quota(sb) && !readonly) {
2734 		ext4_msg(sb, KERN_ERR,
2735 			 "Filesystem with quota feature cannot be mounted RDWR "
2736 			 "without CONFIG_QUOTA");
2737 		return 0;
2738 	}
2739 	if (ext4_has_feature_project(sb) && !readonly) {
2740 		ext4_msg(sb, KERN_ERR,
2741 			 "Filesystem with project quota feature cannot be mounted RDWR "
2742 			 "without CONFIG_QUOTA");
2743 		return 0;
2744 	}
2745 #endif  /* CONFIG_QUOTA */
2746 	return 1;
2747 }
2748 
2749 /*
2750  * This function is called once a day if we have errors logged
2751  * on the file system
2752  */
2753 static void print_daily_error_info(unsigned long arg)
2754 {
2755 	struct super_block *sb = (struct super_block *) arg;
2756 	struct ext4_sb_info *sbi;
2757 	struct ext4_super_block *es;
2758 
2759 	sbi = EXT4_SB(sb);
2760 	es = sbi->s_es;
2761 
2762 	if (es->s_error_count)
2763 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2764 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2765 			 le32_to_cpu(es->s_error_count));
2766 	if (es->s_first_error_time) {
2767 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2768 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2769 		       (int) sizeof(es->s_first_error_func),
2770 		       es->s_first_error_func,
2771 		       le32_to_cpu(es->s_first_error_line));
2772 		if (es->s_first_error_ino)
2773 			printk(KERN_CONT ": inode %u",
2774 			       le32_to_cpu(es->s_first_error_ino));
2775 		if (es->s_first_error_block)
2776 			printk(KERN_CONT ": block %llu", (unsigned long long)
2777 			       le64_to_cpu(es->s_first_error_block));
2778 		printk(KERN_CONT "\n");
2779 	}
2780 	if (es->s_last_error_time) {
2781 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2782 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2783 		       (int) sizeof(es->s_last_error_func),
2784 		       es->s_last_error_func,
2785 		       le32_to_cpu(es->s_last_error_line));
2786 		if (es->s_last_error_ino)
2787 			printk(KERN_CONT ": inode %u",
2788 			       le32_to_cpu(es->s_last_error_ino));
2789 		if (es->s_last_error_block)
2790 			printk(KERN_CONT ": block %llu", (unsigned long long)
2791 			       le64_to_cpu(es->s_last_error_block));
2792 		printk(KERN_CONT "\n");
2793 	}
2794 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2795 }
2796 
2797 /* Find next suitable group and run ext4_init_inode_table */
2798 static int ext4_run_li_request(struct ext4_li_request *elr)
2799 {
2800 	struct ext4_group_desc *gdp = NULL;
2801 	ext4_group_t group, ngroups;
2802 	struct super_block *sb;
2803 	unsigned long timeout = 0;
2804 	int ret = 0;
2805 
2806 	sb = elr->lr_super;
2807 	ngroups = EXT4_SB(sb)->s_groups_count;
2808 
2809 	for (group = elr->lr_next_group; group < ngroups; group++) {
2810 		gdp = ext4_get_group_desc(sb, group, NULL);
2811 		if (!gdp) {
2812 			ret = 1;
2813 			break;
2814 		}
2815 
2816 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2817 			break;
2818 	}
2819 
2820 	if (group >= ngroups)
2821 		ret = 1;
2822 
2823 	if (!ret) {
2824 		timeout = jiffies;
2825 		ret = ext4_init_inode_table(sb, group,
2826 					    elr->lr_timeout ? 0 : 1);
2827 		if (elr->lr_timeout == 0) {
2828 			timeout = (jiffies - timeout) *
2829 				  elr->lr_sbi->s_li_wait_mult;
2830 			elr->lr_timeout = timeout;
2831 		}
2832 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2833 		elr->lr_next_group = group + 1;
2834 	}
2835 	return ret;
2836 }
2837 
2838 /*
2839  * Remove lr_request from the list_request and free the
2840  * request structure. Should be called with li_list_mtx held
2841  */
2842 static void ext4_remove_li_request(struct ext4_li_request *elr)
2843 {
2844 	struct ext4_sb_info *sbi;
2845 
2846 	if (!elr)
2847 		return;
2848 
2849 	sbi = elr->lr_sbi;
2850 
2851 	list_del(&elr->lr_request);
2852 	sbi->s_li_request = NULL;
2853 	kfree(elr);
2854 }
2855 
2856 static void ext4_unregister_li_request(struct super_block *sb)
2857 {
2858 	mutex_lock(&ext4_li_mtx);
2859 	if (!ext4_li_info) {
2860 		mutex_unlock(&ext4_li_mtx);
2861 		return;
2862 	}
2863 
2864 	mutex_lock(&ext4_li_info->li_list_mtx);
2865 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2866 	mutex_unlock(&ext4_li_info->li_list_mtx);
2867 	mutex_unlock(&ext4_li_mtx);
2868 }
2869 
2870 static struct task_struct *ext4_lazyinit_task;
2871 
2872 /*
2873  * This is the function where ext4lazyinit thread lives. It walks
2874  * through the request list searching for next scheduled filesystem.
2875  * When such a fs is found, run the lazy initialization request
2876  * (ext4_rn_li_request) and keep track of the time spend in this
2877  * function. Based on that time we compute next schedule time of
2878  * the request. When walking through the list is complete, compute
2879  * next waking time and put itself into sleep.
2880  */
2881 static int ext4_lazyinit_thread(void *arg)
2882 {
2883 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2884 	struct list_head *pos, *n;
2885 	struct ext4_li_request *elr;
2886 	unsigned long next_wakeup, cur;
2887 
2888 	BUG_ON(NULL == eli);
2889 
2890 cont_thread:
2891 	while (true) {
2892 		next_wakeup = MAX_JIFFY_OFFSET;
2893 
2894 		mutex_lock(&eli->li_list_mtx);
2895 		if (list_empty(&eli->li_request_list)) {
2896 			mutex_unlock(&eli->li_list_mtx);
2897 			goto exit_thread;
2898 		}
2899 		list_for_each_safe(pos, n, &eli->li_request_list) {
2900 			int err = 0;
2901 			int progress = 0;
2902 			elr = list_entry(pos, struct ext4_li_request,
2903 					 lr_request);
2904 
2905 			if (time_before(jiffies, elr->lr_next_sched)) {
2906 				if (time_before(elr->lr_next_sched, next_wakeup))
2907 					next_wakeup = elr->lr_next_sched;
2908 				continue;
2909 			}
2910 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2911 				if (sb_start_write_trylock(elr->lr_super)) {
2912 					progress = 1;
2913 					/*
2914 					 * We hold sb->s_umount, sb can not
2915 					 * be removed from the list, it is
2916 					 * now safe to drop li_list_mtx
2917 					 */
2918 					mutex_unlock(&eli->li_list_mtx);
2919 					err = ext4_run_li_request(elr);
2920 					sb_end_write(elr->lr_super);
2921 					mutex_lock(&eli->li_list_mtx);
2922 					n = pos->next;
2923 				}
2924 				up_read((&elr->lr_super->s_umount));
2925 			}
2926 			/* error, remove the lazy_init job */
2927 			if (err) {
2928 				ext4_remove_li_request(elr);
2929 				continue;
2930 			}
2931 			if (!progress) {
2932 				elr->lr_next_sched = jiffies +
2933 					(prandom_u32()
2934 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2935 			}
2936 			if (time_before(elr->lr_next_sched, next_wakeup))
2937 				next_wakeup = elr->lr_next_sched;
2938 		}
2939 		mutex_unlock(&eli->li_list_mtx);
2940 
2941 		try_to_freeze();
2942 
2943 		cur = jiffies;
2944 		if ((time_after_eq(cur, next_wakeup)) ||
2945 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2946 			cond_resched();
2947 			continue;
2948 		}
2949 
2950 		schedule_timeout_interruptible(next_wakeup - cur);
2951 
2952 		if (kthread_should_stop()) {
2953 			ext4_clear_request_list();
2954 			goto exit_thread;
2955 		}
2956 	}
2957 
2958 exit_thread:
2959 	/*
2960 	 * It looks like the request list is empty, but we need
2961 	 * to check it under the li_list_mtx lock, to prevent any
2962 	 * additions into it, and of course we should lock ext4_li_mtx
2963 	 * to atomically free the list and ext4_li_info, because at
2964 	 * this point another ext4 filesystem could be registering
2965 	 * new one.
2966 	 */
2967 	mutex_lock(&ext4_li_mtx);
2968 	mutex_lock(&eli->li_list_mtx);
2969 	if (!list_empty(&eli->li_request_list)) {
2970 		mutex_unlock(&eli->li_list_mtx);
2971 		mutex_unlock(&ext4_li_mtx);
2972 		goto cont_thread;
2973 	}
2974 	mutex_unlock(&eli->li_list_mtx);
2975 	kfree(ext4_li_info);
2976 	ext4_li_info = NULL;
2977 	mutex_unlock(&ext4_li_mtx);
2978 
2979 	return 0;
2980 }
2981 
2982 static void ext4_clear_request_list(void)
2983 {
2984 	struct list_head *pos, *n;
2985 	struct ext4_li_request *elr;
2986 
2987 	mutex_lock(&ext4_li_info->li_list_mtx);
2988 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2989 		elr = list_entry(pos, struct ext4_li_request,
2990 				 lr_request);
2991 		ext4_remove_li_request(elr);
2992 	}
2993 	mutex_unlock(&ext4_li_info->li_list_mtx);
2994 }
2995 
2996 static int ext4_run_lazyinit_thread(void)
2997 {
2998 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2999 					 ext4_li_info, "ext4lazyinit");
3000 	if (IS_ERR(ext4_lazyinit_task)) {
3001 		int err = PTR_ERR(ext4_lazyinit_task);
3002 		ext4_clear_request_list();
3003 		kfree(ext4_li_info);
3004 		ext4_li_info = NULL;
3005 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3006 				 "initialization thread\n",
3007 				 err);
3008 		return err;
3009 	}
3010 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3011 	return 0;
3012 }
3013 
3014 /*
3015  * Check whether it make sense to run itable init. thread or not.
3016  * If there is at least one uninitialized inode table, return
3017  * corresponding group number, else the loop goes through all
3018  * groups and return total number of groups.
3019  */
3020 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3021 {
3022 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3023 	struct ext4_group_desc *gdp = NULL;
3024 
3025 	for (group = 0; group < ngroups; group++) {
3026 		gdp = ext4_get_group_desc(sb, group, NULL);
3027 		if (!gdp)
3028 			continue;
3029 
3030 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3031 			break;
3032 	}
3033 
3034 	return group;
3035 }
3036 
3037 static int ext4_li_info_new(void)
3038 {
3039 	struct ext4_lazy_init *eli = NULL;
3040 
3041 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3042 	if (!eli)
3043 		return -ENOMEM;
3044 
3045 	INIT_LIST_HEAD(&eli->li_request_list);
3046 	mutex_init(&eli->li_list_mtx);
3047 
3048 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3049 
3050 	ext4_li_info = eli;
3051 
3052 	return 0;
3053 }
3054 
3055 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3056 					    ext4_group_t start)
3057 {
3058 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3059 	struct ext4_li_request *elr;
3060 
3061 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3062 	if (!elr)
3063 		return NULL;
3064 
3065 	elr->lr_super = sb;
3066 	elr->lr_sbi = sbi;
3067 	elr->lr_next_group = start;
3068 
3069 	/*
3070 	 * Randomize first schedule time of the request to
3071 	 * spread the inode table initialization requests
3072 	 * better.
3073 	 */
3074 	elr->lr_next_sched = jiffies + (prandom_u32() %
3075 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3076 	return elr;
3077 }
3078 
3079 int ext4_register_li_request(struct super_block *sb,
3080 			     ext4_group_t first_not_zeroed)
3081 {
3082 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3083 	struct ext4_li_request *elr = NULL;
3084 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3085 	int ret = 0;
3086 
3087 	mutex_lock(&ext4_li_mtx);
3088 	if (sbi->s_li_request != NULL) {
3089 		/*
3090 		 * Reset timeout so it can be computed again, because
3091 		 * s_li_wait_mult might have changed.
3092 		 */
3093 		sbi->s_li_request->lr_timeout = 0;
3094 		goto out;
3095 	}
3096 
3097 	if (first_not_zeroed == ngroups ||
3098 	    (sb->s_flags & MS_RDONLY) ||
3099 	    !test_opt(sb, INIT_INODE_TABLE))
3100 		goto out;
3101 
3102 	elr = ext4_li_request_new(sb, first_not_zeroed);
3103 	if (!elr) {
3104 		ret = -ENOMEM;
3105 		goto out;
3106 	}
3107 
3108 	if (NULL == ext4_li_info) {
3109 		ret = ext4_li_info_new();
3110 		if (ret)
3111 			goto out;
3112 	}
3113 
3114 	mutex_lock(&ext4_li_info->li_list_mtx);
3115 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3116 	mutex_unlock(&ext4_li_info->li_list_mtx);
3117 
3118 	sbi->s_li_request = elr;
3119 	/*
3120 	 * set elr to NULL here since it has been inserted to
3121 	 * the request_list and the removal and free of it is
3122 	 * handled by ext4_clear_request_list from now on.
3123 	 */
3124 	elr = NULL;
3125 
3126 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3127 		ret = ext4_run_lazyinit_thread();
3128 		if (ret)
3129 			goto out;
3130 	}
3131 out:
3132 	mutex_unlock(&ext4_li_mtx);
3133 	if (ret)
3134 		kfree(elr);
3135 	return ret;
3136 }
3137 
3138 /*
3139  * We do not need to lock anything since this is called on
3140  * module unload.
3141  */
3142 static void ext4_destroy_lazyinit_thread(void)
3143 {
3144 	/*
3145 	 * If thread exited earlier
3146 	 * there's nothing to be done.
3147 	 */
3148 	if (!ext4_li_info || !ext4_lazyinit_task)
3149 		return;
3150 
3151 	kthread_stop(ext4_lazyinit_task);
3152 }
3153 
3154 static int set_journal_csum_feature_set(struct super_block *sb)
3155 {
3156 	int ret = 1;
3157 	int compat, incompat;
3158 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3159 
3160 	if (ext4_has_metadata_csum(sb)) {
3161 		/* journal checksum v3 */
3162 		compat = 0;
3163 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3164 	} else {
3165 		/* journal checksum v1 */
3166 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3167 		incompat = 0;
3168 	}
3169 
3170 	jbd2_journal_clear_features(sbi->s_journal,
3171 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3172 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3173 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3174 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3175 		ret = jbd2_journal_set_features(sbi->s_journal,
3176 				compat, 0,
3177 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3178 				incompat);
3179 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3180 		ret = jbd2_journal_set_features(sbi->s_journal,
3181 				compat, 0,
3182 				incompat);
3183 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3184 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3185 	} else {
3186 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3187 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3188 	}
3189 
3190 	return ret;
3191 }
3192 
3193 /*
3194  * Note: calculating the overhead so we can be compatible with
3195  * historical BSD practice is quite difficult in the face of
3196  * clusters/bigalloc.  This is because multiple metadata blocks from
3197  * different block group can end up in the same allocation cluster.
3198  * Calculating the exact overhead in the face of clustered allocation
3199  * requires either O(all block bitmaps) in memory or O(number of block
3200  * groups**2) in time.  We will still calculate the superblock for
3201  * older file systems --- and if we come across with a bigalloc file
3202  * system with zero in s_overhead_clusters the estimate will be close to
3203  * correct especially for very large cluster sizes --- but for newer
3204  * file systems, it's better to calculate this figure once at mkfs
3205  * time, and store it in the superblock.  If the superblock value is
3206  * present (even for non-bigalloc file systems), we will use it.
3207  */
3208 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3209 			  char *buf)
3210 {
3211 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3212 	struct ext4_group_desc	*gdp;
3213 	ext4_fsblk_t		first_block, last_block, b;
3214 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3215 	int			s, j, count = 0;
3216 
3217 	if (!ext4_has_feature_bigalloc(sb))
3218 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3219 			sbi->s_itb_per_group + 2);
3220 
3221 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3222 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3223 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3224 	for (i = 0; i < ngroups; i++) {
3225 		gdp = ext4_get_group_desc(sb, i, NULL);
3226 		b = ext4_block_bitmap(sb, gdp);
3227 		if (b >= first_block && b <= last_block) {
3228 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3229 			count++;
3230 		}
3231 		b = ext4_inode_bitmap(sb, gdp);
3232 		if (b >= first_block && b <= last_block) {
3233 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3234 			count++;
3235 		}
3236 		b = ext4_inode_table(sb, gdp);
3237 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3238 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3239 				int c = EXT4_B2C(sbi, b - first_block);
3240 				ext4_set_bit(c, buf);
3241 				count++;
3242 			}
3243 		if (i != grp)
3244 			continue;
3245 		s = 0;
3246 		if (ext4_bg_has_super(sb, grp)) {
3247 			ext4_set_bit(s++, buf);
3248 			count++;
3249 		}
3250 		j = ext4_bg_num_gdb(sb, grp);
3251 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3252 			ext4_error(sb, "Invalid number of block group "
3253 				   "descriptor blocks: %d", j);
3254 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3255 		}
3256 		count += j;
3257 		for (; j > 0; j--)
3258 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3259 	}
3260 	if (!count)
3261 		return 0;
3262 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3263 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3264 }
3265 
3266 /*
3267  * Compute the overhead and stash it in sbi->s_overhead
3268  */
3269 int ext4_calculate_overhead(struct super_block *sb)
3270 {
3271 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3272 	struct ext4_super_block *es = sbi->s_es;
3273 	struct inode *j_inode;
3274 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3275 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3276 	ext4_fsblk_t overhead = 0;
3277 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3278 
3279 	if (!buf)
3280 		return -ENOMEM;
3281 
3282 	/*
3283 	 * Compute the overhead (FS structures).  This is constant
3284 	 * for a given filesystem unless the number of block groups
3285 	 * changes so we cache the previous value until it does.
3286 	 */
3287 
3288 	/*
3289 	 * All of the blocks before first_data_block are overhead
3290 	 */
3291 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3292 
3293 	/*
3294 	 * Add the overhead found in each block group
3295 	 */
3296 	for (i = 0; i < ngroups; i++) {
3297 		int blks;
3298 
3299 		blks = count_overhead(sb, i, buf);
3300 		overhead += blks;
3301 		if (blks)
3302 			memset(buf, 0, PAGE_SIZE);
3303 		cond_resched();
3304 	}
3305 
3306 	/*
3307 	 * Add the internal journal blocks whether the journal has been
3308 	 * loaded or not
3309 	 */
3310 	if (sbi->s_journal && !sbi->journal_bdev)
3311 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3312 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3313 		j_inode = ext4_get_journal_inode(sb, j_inum);
3314 		if (j_inode) {
3315 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3316 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3317 			iput(j_inode);
3318 		} else {
3319 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3320 		}
3321 	}
3322 	sbi->s_overhead = overhead;
3323 	smp_wmb();
3324 	free_page((unsigned long) buf);
3325 	return 0;
3326 }
3327 
3328 static void ext4_set_resv_clusters(struct super_block *sb)
3329 {
3330 	ext4_fsblk_t resv_clusters;
3331 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3332 
3333 	/*
3334 	 * There's no need to reserve anything when we aren't using extents.
3335 	 * The space estimates are exact, there are no unwritten extents,
3336 	 * hole punching doesn't need new metadata... This is needed especially
3337 	 * to keep ext2/3 backward compatibility.
3338 	 */
3339 	if (!ext4_has_feature_extents(sb))
3340 		return;
3341 	/*
3342 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3343 	 * This should cover the situations where we can not afford to run
3344 	 * out of space like for example punch hole, or converting
3345 	 * unwritten extents in delalloc path. In most cases such
3346 	 * allocation would require 1, or 2 blocks, higher numbers are
3347 	 * very rare.
3348 	 */
3349 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3350 			 sbi->s_cluster_bits);
3351 
3352 	do_div(resv_clusters, 50);
3353 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3354 
3355 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3356 }
3357 
3358 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3359 {
3360 	char *orig_data = kstrdup(data, GFP_KERNEL);
3361 	struct buffer_head *bh;
3362 	struct ext4_super_block *es = NULL;
3363 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3364 	ext4_fsblk_t block;
3365 	ext4_fsblk_t sb_block = get_sb_block(&data);
3366 	ext4_fsblk_t logical_sb_block;
3367 	unsigned long offset = 0;
3368 	unsigned long journal_devnum = 0;
3369 	unsigned long def_mount_opts;
3370 	struct inode *root;
3371 	const char *descr;
3372 	int ret = -ENOMEM;
3373 	int blocksize, clustersize;
3374 	unsigned int db_count;
3375 	unsigned int i;
3376 	int needs_recovery, has_huge_files, has_bigalloc;
3377 	__u64 blocks_count;
3378 	int err = 0;
3379 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3380 	ext4_group_t first_not_zeroed;
3381 
3382 	if ((data && !orig_data) || !sbi)
3383 		goto out_free_base;
3384 
3385 	sbi->s_blockgroup_lock =
3386 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3387 	if (!sbi->s_blockgroup_lock)
3388 		goto out_free_base;
3389 
3390 	sb->s_fs_info = sbi;
3391 	sbi->s_sb = sb;
3392 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3393 	sbi->s_sb_block = sb_block;
3394 	if (sb->s_bdev->bd_part)
3395 		sbi->s_sectors_written_start =
3396 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3397 
3398 	/* Cleanup superblock name */
3399 	strreplace(sb->s_id, '/', '!');
3400 
3401 	/* -EINVAL is default */
3402 	ret = -EINVAL;
3403 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3404 	if (!blocksize) {
3405 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3406 		goto out_fail;
3407 	}
3408 
3409 	/*
3410 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3411 	 * block sizes.  We need to calculate the offset from buffer start.
3412 	 */
3413 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3414 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3415 		offset = do_div(logical_sb_block, blocksize);
3416 	} else {
3417 		logical_sb_block = sb_block;
3418 	}
3419 
3420 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3421 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3422 		goto out_fail;
3423 	}
3424 	/*
3425 	 * Note: s_es must be initialized as soon as possible because
3426 	 *       some ext4 macro-instructions depend on its value
3427 	 */
3428 	es = (struct ext4_super_block *) (bh->b_data + offset);
3429 	sbi->s_es = es;
3430 	sb->s_magic = le16_to_cpu(es->s_magic);
3431 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3432 		goto cantfind_ext4;
3433 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3434 
3435 	/* Warn if metadata_csum and gdt_csum are both set. */
3436 	if (ext4_has_feature_metadata_csum(sb) &&
3437 	    ext4_has_feature_gdt_csum(sb))
3438 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3439 			     "redundant flags; please run fsck.");
3440 
3441 	/* Check for a known checksum algorithm */
3442 	if (!ext4_verify_csum_type(sb, es)) {
3443 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3444 			 "unknown checksum algorithm.");
3445 		silent = 1;
3446 		goto cantfind_ext4;
3447 	}
3448 
3449 	/* Load the checksum driver */
3450 	if (ext4_has_feature_metadata_csum(sb)) {
3451 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3452 		if (IS_ERR(sbi->s_chksum_driver)) {
3453 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3454 			ret = PTR_ERR(sbi->s_chksum_driver);
3455 			sbi->s_chksum_driver = NULL;
3456 			goto failed_mount;
3457 		}
3458 	}
3459 
3460 	/* Check superblock checksum */
3461 	if (!ext4_superblock_csum_verify(sb, es)) {
3462 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3463 			 "invalid superblock checksum.  Run e2fsck?");
3464 		silent = 1;
3465 		ret = -EFSBADCRC;
3466 		goto cantfind_ext4;
3467 	}
3468 
3469 	/* Precompute checksum seed for all metadata */
3470 	if (ext4_has_feature_csum_seed(sb))
3471 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3472 	else if (ext4_has_metadata_csum(sb))
3473 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3474 					       sizeof(es->s_uuid));
3475 
3476 	/* Set defaults before we parse the mount options */
3477 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3478 	set_opt(sb, INIT_INODE_TABLE);
3479 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3480 		set_opt(sb, DEBUG);
3481 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3482 		set_opt(sb, GRPID);
3483 	if (def_mount_opts & EXT4_DEFM_UID16)
3484 		set_opt(sb, NO_UID32);
3485 	/* xattr user namespace & acls are now defaulted on */
3486 	set_opt(sb, XATTR_USER);
3487 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3488 	set_opt(sb, POSIX_ACL);
3489 #endif
3490 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3491 	if (ext4_has_metadata_csum(sb))
3492 		set_opt(sb, JOURNAL_CHECKSUM);
3493 
3494 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3495 		set_opt(sb, JOURNAL_DATA);
3496 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3497 		set_opt(sb, ORDERED_DATA);
3498 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3499 		set_opt(sb, WRITEBACK_DATA);
3500 
3501 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3502 		set_opt(sb, ERRORS_PANIC);
3503 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3504 		set_opt(sb, ERRORS_CONT);
3505 	else
3506 		set_opt(sb, ERRORS_RO);
3507 	/* block_validity enabled by default; disable with noblock_validity */
3508 	set_opt(sb, BLOCK_VALIDITY);
3509 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3510 		set_opt(sb, DISCARD);
3511 
3512 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3513 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3514 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3515 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3516 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3517 
3518 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3519 		set_opt(sb, BARRIER);
3520 
3521 	/*
3522 	 * enable delayed allocation by default
3523 	 * Use -o nodelalloc to turn it off
3524 	 */
3525 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3526 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3527 		set_opt(sb, DELALLOC);
3528 
3529 	/*
3530 	 * set default s_li_wait_mult for lazyinit, for the case there is
3531 	 * no mount option specified.
3532 	 */
3533 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3534 
3535 	if (sbi->s_es->s_mount_opts[0]) {
3536 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3537 					      sizeof(sbi->s_es->s_mount_opts),
3538 					      GFP_KERNEL);
3539 		if (!s_mount_opts)
3540 			goto failed_mount;
3541 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3542 				   &journal_ioprio, 0)) {
3543 			ext4_msg(sb, KERN_WARNING,
3544 				 "failed to parse options in superblock: %s",
3545 				 s_mount_opts);
3546 		}
3547 		kfree(s_mount_opts);
3548 	}
3549 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3550 	if (!parse_options((char *) data, sb, &journal_devnum,
3551 			   &journal_ioprio, 0))
3552 		goto failed_mount;
3553 
3554 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3555 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3556 			    "with data=journal disables delayed "
3557 			    "allocation and O_DIRECT support!\n");
3558 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3559 			ext4_msg(sb, KERN_ERR, "can't mount with "
3560 				 "both data=journal and delalloc");
3561 			goto failed_mount;
3562 		}
3563 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3564 			ext4_msg(sb, KERN_ERR, "can't mount with "
3565 				 "both data=journal and dioread_nolock");
3566 			goto failed_mount;
3567 		}
3568 		if (test_opt(sb, DAX)) {
3569 			ext4_msg(sb, KERN_ERR, "can't mount with "
3570 				 "both data=journal and dax");
3571 			goto failed_mount;
3572 		}
3573 		if (ext4_has_feature_encrypt(sb)) {
3574 			ext4_msg(sb, KERN_WARNING,
3575 				 "encrypted files will use data=ordered "
3576 				 "instead of data journaling mode");
3577 		}
3578 		if (test_opt(sb, DELALLOC))
3579 			clear_opt(sb, DELALLOC);
3580 	} else {
3581 		sb->s_iflags |= SB_I_CGROUPWB;
3582 	}
3583 
3584 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3585 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3586 
3587 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3588 	    (ext4_has_compat_features(sb) ||
3589 	     ext4_has_ro_compat_features(sb) ||
3590 	     ext4_has_incompat_features(sb)))
3591 		ext4_msg(sb, KERN_WARNING,
3592 		       "feature flags set on rev 0 fs, "
3593 		       "running e2fsck is recommended");
3594 
3595 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3596 		set_opt2(sb, HURD_COMPAT);
3597 		if (ext4_has_feature_64bit(sb)) {
3598 			ext4_msg(sb, KERN_ERR,
3599 				 "The Hurd can't support 64-bit file systems");
3600 			goto failed_mount;
3601 		}
3602 	}
3603 
3604 	if (IS_EXT2_SB(sb)) {
3605 		if (ext2_feature_set_ok(sb))
3606 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3607 				 "using the ext4 subsystem");
3608 		else {
3609 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3610 				 "to feature incompatibilities");
3611 			goto failed_mount;
3612 		}
3613 	}
3614 
3615 	if (IS_EXT3_SB(sb)) {
3616 		if (ext3_feature_set_ok(sb))
3617 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3618 				 "using the ext4 subsystem");
3619 		else {
3620 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3621 				 "to feature incompatibilities");
3622 			goto failed_mount;
3623 		}
3624 	}
3625 
3626 	/*
3627 	 * Check feature flags regardless of the revision level, since we
3628 	 * previously didn't change the revision level when setting the flags,
3629 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3630 	 */
3631 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3632 		goto failed_mount;
3633 
3634 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3635 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3636 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3637 		ext4_msg(sb, KERN_ERR,
3638 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3639 			 blocksize, le32_to_cpu(es->s_log_block_size));
3640 		goto failed_mount;
3641 	}
3642 	if (le32_to_cpu(es->s_log_block_size) >
3643 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3644 		ext4_msg(sb, KERN_ERR,
3645 			 "Invalid log block size: %u",
3646 			 le32_to_cpu(es->s_log_block_size));
3647 		goto failed_mount;
3648 	}
3649 
3650 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3651 		ext4_msg(sb, KERN_ERR,
3652 			 "Number of reserved GDT blocks insanely large: %d",
3653 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3654 		goto failed_mount;
3655 	}
3656 
3657 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3658 		err = bdev_dax_supported(sb, blocksize);
3659 		if (err)
3660 			goto failed_mount;
3661 	}
3662 
3663 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3664 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3665 			 es->s_encryption_level);
3666 		goto failed_mount;
3667 	}
3668 
3669 	if (sb->s_blocksize != blocksize) {
3670 		/* Validate the filesystem blocksize */
3671 		if (!sb_set_blocksize(sb, blocksize)) {
3672 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3673 					blocksize);
3674 			goto failed_mount;
3675 		}
3676 
3677 		brelse(bh);
3678 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3679 		offset = do_div(logical_sb_block, blocksize);
3680 		bh = sb_bread_unmovable(sb, logical_sb_block);
3681 		if (!bh) {
3682 			ext4_msg(sb, KERN_ERR,
3683 			       "Can't read superblock on 2nd try");
3684 			goto failed_mount;
3685 		}
3686 		es = (struct ext4_super_block *)(bh->b_data + offset);
3687 		sbi->s_es = es;
3688 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3689 			ext4_msg(sb, KERN_ERR,
3690 			       "Magic mismatch, very weird!");
3691 			goto failed_mount;
3692 		}
3693 	}
3694 
3695 	has_huge_files = ext4_has_feature_huge_file(sb);
3696 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3697 						      has_huge_files);
3698 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3699 
3700 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3701 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3702 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3703 	} else {
3704 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3705 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3706 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3707 		    (!is_power_of_2(sbi->s_inode_size)) ||
3708 		    (sbi->s_inode_size > blocksize)) {
3709 			ext4_msg(sb, KERN_ERR,
3710 			       "unsupported inode size: %d",
3711 			       sbi->s_inode_size);
3712 			goto failed_mount;
3713 		}
3714 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3715 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3716 	}
3717 
3718 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3719 	if (ext4_has_feature_64bit(sb)) {
3720 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3721 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3722 		    !is_power_of_2(sbi->s_desc_size)) {
3723 			ext4_msg(sb, KERN_ERR,
3724 			       "unsupported descriptor size %lu",
3725 			       sbi->s_desc_size);
3726 			goto failed_mount;
3727 		}
3728 	} else
3729 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3730 
3731 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3732 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3733 
3734 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3735 	if (sbi->s_inodes_per_block == 0)
3736 		goto cantfind_ext4;
3737 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3738 	    sbi->s_inodes_per_group > blocksize * 8) {
3739 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3740 			 sbi->s_blocks_per_group);
3741 		goto failed_mount;
3742 	}
3743 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3744 					sbi->s_inodes_per_block;
3745 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3746 	sbi->s_sbh = bh;
3747 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3748 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3749 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3750 
3751 	for (i = 0; i < 4; i++)
3752 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3753 	sbi->s_def_hash_version = es->s_def_hash_version;
3754 	if (ext4_has_feature_dir_index(sb)) {
3755 		i = le32_to_cpu(es->s_flags);
3756 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3757 			sbi->s_hash_unsigned = 3;
3758 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3759 #ifdef __CHAR_UNSIGNED__
3760 			if (!(sb->s_flags & MS_RDONLY))
3761 				es->s_flags |=
3762 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3763 			sbi->s_hash_unsigned = 3;
3764 #else
3765 			if (!(sb->s_flags & MS_RDONLY))
3766 				es->s_flags |=
3767 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3768 #endif
3769 		}
3770 	}
3771 
3772 	/* Handle clustersize */
3773 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3774 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3775 	if (has_bigalloc) {
3776 		if (clustersize < blocksize) {
3777 			ext4_msg(sb, KERN_ERR,
3778 				 "cluster size (%d) smaller than "
3779 				 "block size (%d)", clustersize, blocksize);
3780 			goto failed_mount;
3781 		}
3782 		if (le32_to_cpu(es->s_log_cluster_size) >
3783 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3784 			ext4_msg(sb, KERN_ERR,
3785 				 "Invalid log cluster size: %u",
3786 				 le32_to_cpu(es->s_log_cluster_size));
3787 			goto failed_mount;
3788 		}
3789 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3790 			le32_to_cpu(es->s_log_block_size);
3791 		sbi->s_clusters_per_group =
3792 			le32_to_cpu(es->s_clusters_per_group);
3793 		if (sbi->s_clusters_per_group > blocksize * 8) {
3794 			ext4_msg(sb, KERN_ERR,
3795 				 "#clusters per group too big: %lu",
3796 				 sbi->s_clusters_per_group);
3797 			goto failed_mount;
3798 		}
3799 		if (sbi->s_blocks_per_group !=
3800 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3801 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3802 				 "clusters per group (%lu) inconsistent",
3803 				 sbi->s_blocks_per_group,
3804 				 sbi->s_clusters_per_group);
3805 			goto failed_mount;
3806 		}
3807 	} else {
3808 		if (clustersize != blocksize) {
3809 			ext4_warning(sb, "fragment/cluster size (%d) != "
3810 				     "block size (%d)", clustersize,
3811 				     blocksize);
3812 			clustersize = blocksize;
3813 		}
3814 		if (sbi->s_blocks_per_group > blocksize * 8) {
3815 			ext4_msg(sb, KERN_ERR,
3816 				 "#blocks per group too big: %lu",
3817 				 sbi->s_blocks_per_group);
3818 			goto failed_mount;
3819 		}
3820 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3821 		sbi->s_cluster_bits = 0;
3822 	}
3823 	sbi->s_cluster_ratio = clustersize / blocksize;
3824 
3825 	/* Do we have standard group size of clustersize * 8 blocks ? */
3826 	if (sbi->s_blocks_per_group == clustersize << 3)
3827 		set_opt2(sb, STD_GROUP_SIZE);
3828 
3829 	/*
3830 	 * Test whether we have more sectors than will fit in sector_t,
3831 	 * and whether the max offset is addressable by the page cache.
3832 	 */
3833 	err = generic_check_addressable(sb->s_blocksize_bits,
3834 					ext4_blocks_count(es));
3835 	if (err) {
3836 		ext4_msg(sb, KERN_ERR, "filesystem"
3837 			 " too large to mount safely on this system");
3838 		if (sizeof(sector_t) < 8)
3839 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3840 		goto failed_mount;
3841 	}
3842 
3843 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3844 		goto cantfind_ext4;
3845 
3846 	/* check blocks count against device size */
3847 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3848 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3849 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3850 		       "exceeds size of device (%llu blocks)",
3851 		       ext4_blocks_count(es), blocks_count);
3852 		goto failed_mount;
3853 	}
3854 
3855 	/*
3856 	 * It makes no sense for the first data block to be beyond the end
3857 	 * of the filesystem.
3858 	 */
3859 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3860 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3861 			 "block %u is beyond end of filesystem (%llu)",
3862 			 le32_to_cpu(es->s_first_data_block),
3863 			 ext4_blocks_count(es));
3864 		goto failed_mount;
3865 	}
3866 	blocks_count = (ext4_blocks_count(es) -
3867 			le32_to_cpu(es->s_first_data_block) +
3868 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3869 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3870 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3871 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3872 		       "(block count %llu, first data block %u, "
3873 		       "blocks per group %lu)", sbi->s_groups_count,
3874 		       ext4_blocks_count(es),
3875 		       le32_to_cpu(es->s_first_data_block),
3876 		       EXT4_BLOCKS_PER_GROUP(sb));
3877 		goto failed_mount;
3878 	}
3879 	sbi->s_groups_count = blocks_count;
3880 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3881 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3882 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3883 		   EXT4_DESC_PER_BLOCK(sb);
3884 	if (ext4_has_feature_meta_bg(sb)) {
3885 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3886 			ext4_msg(sb, KERN_WARNING,
3887 				 "first meta block group too large: %u "
3888 				 "(group descriptor block count %u)",
3889 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3890 			goto failed_mount;
3891 		}
3892 	}
3893 	sbi->s_group_desc = kvmalloc(db_count *
3894 					  sizeof(struct buffer_head *),
3895 					  GFP_KERNEL);
3896 	if (sbi->s_group_desc == NULL) {
3897 		ext4_msg(sb, KERN_ERR, "not enough memory");
3898 		ret = -ENOMEM;
3899 		goto failed_mount;
3900 	}
3901 
3902 	bgl_lock_init(sbi->s_blockgroup_lock);
3903 
3904 	/* Pre-read the descriptors into the buffer cache */
3905 	for (i = 0; i < db_count; i++) {
3906 		block = descriptor_loc(sb, logical_sb_block, i);
3907 		sb_breadahead(sb, block);
3908 	}
3909 
3910 	for (i = 0; i < db_count; i++) {
3911 		block = descriptor_loc(sb, logical_sb_block, i);
3912 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3913 		if (!sbi->s_group_desc[i]) {
3914 			ext4_msg(sb, KERN_ERR,
3915 			       "can't read group descriptor %d", i);
3916 			db_count = i;
3917 			goto failed_mount2;
3918 		}
3919 	}
3920 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3921 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3922 		ret = -EFSCORRUPTED;
3923 		goto failed_mount2;
3924 	}
3925 
3926 	sbi->s_gdb_count = db_count;
3927 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3928 	spin_lock_init(&sbi->s_next_gen_lock);
3929 
3930 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3931 		(unsigned long) sb);
3932 
3933 	/* Register extent status tree shrinker */
3934 	if (ext4_es_register_shrinker(sbi))
3935 		goto failed_mount3;
3936 
3937 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3938 	sbi->s_extent_max_zeroout_kb = 32;
3939 
3940 	/*
3941 	 * set up enough so that it can read an inode
3942 	 */
3943 	sb->s_op = &ext4_sops;
3944 	sb->s_export_op = &ext4_export_ops;
3945 	sb->s_xattr = ext4_xattr_handlers;
3946 	sb->s_cop = &ext4_cryptops;
3947 #ifdef CONFIG_QUOTA
3948 	sb->dq_op = &ext4_quota_operations;
3949 	if (ext4_has_feature_quota(sb))
3950 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3951 	else
3952 		sb->s_qcop = &ext4_qctl_operations;
3953 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3954 #endif
3955 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3956 
3957 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3958 	mutex_init(&sbi->s_orphan_lock);
3959 
3960 	sb->s_root = NULL;
3961 
3962 	needs_recovery = (es->s_last_orphan != 0 ||
3963 			  ext4_has_feature_journal_needs_recovery(sb));
3964 
3965 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3966 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3967 			goto failed_mount3a;
3968 
3969 	/*
3970 	 * The first inode we look at is the journal inode.  Don't try
3971 	 * root first: it may be modified in the journal!
3972 	 */
3973 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3974 		err = ext4_load_journal(sb, es, journal_devnum);
3975 		if (err)
3976 			goto failed_mount3a;
3977 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3978 		   ext4_has_feature_journal_needs_recovery(sb)) {
3979 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3980 		       "suppressed and not mounted read-only");
3981 		goto failed_mount_wq;
3982 	} else {
3983 		/* Nojournal mode, all journal mount options are illegal */
3984 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3985 			ext4_msg(sb, KERN_ERR, "can't mount with "
3986 				 "journal_checksum, fs mounted w/o journal");
3987 			goto failed_mount_wq;
3988 		}
3989 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3990 			ext4_msg(sb, KERN_ERR, "can't mount with "
3991 				 "journal_async_commit, fs mounted w/o journal");
3992 			goto failed_mount_wq;
3993 		}
3994 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3995 			ext4_msg(sb, KERN_ERR, "can't mount with "
3996 				 "commit=%lu, fs mounted w/o journal",
3997 				 sbi->s_commit_interval / HZ);
3998 			goto failed_mount_wq;
3999 		}
4000 		if (EXT4_MOUNT_DATA_FLAGS &
4001 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4002 			ext4_msg(sb, KERN_ERR, "can't mount with "
4003 				 "data=, fs mounted w/o journal");
4004 			goto failed_mount_wq;
4005 		}
4006 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4007 		clear_opt(sb, JOURNAL_CHECKSUM);
4008 		clear_opt(sb, DATA_FLAGS);
4009 		sbi->s_journal = NULL;
4010 		needs_recovery = 0;
4011 		goto no_journal;
4012 	}
4013 
4014 	if (ext4_has_feature_64bit(sb) &&
4015 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4016 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4017 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4018 		goto failed_mount_wq;
4019 	}
4020 
4021 	if (!set_journal_csum_feature_set(sb)) {
4022 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4023 			 "feature set");
4024 		goto failed_mount_wq;
4025 	}
4026 
4027 	/* We have now updated the journal if required, so we can
4028 	 * validate the data journaling mode. */
4029 	switch (test_opt(sb, DATA_FLAGS)) {
4030 	case 0:
4031 		/* No mode set, assume a default based on the journal
4032 		 * capabilities: ORDERED_DATA if the journal can
4033 		 * cope, else JOURNAL_DATA
4034 		 */
4035 		if (jbd2_journal_check_available_features
4036 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4037 			set_opt(sb, ORDERED_DATA);
4038 		else
4039 			set_opt(sb, JOURNAL_DATA);
4040 		break;
4041 
4042 	case EXT4_MOUNT_ORDERED_DATA:
4043 	case EXT4_MOUNT_WRITEBACK_DATA:
4044 		if (!jbd2_journal_check_available_features
4045 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4046 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4047 			       "requested data journaling mode");
4048 			goto failed_mount_wq;
4049 		}
4050 	default:
4051 		break;
4052 	}
4053 
4054 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4055 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4056 		ext4_msg(sb, KERN_ERR, "can't mount with "
4057 			"journal_async_commit in data=ordered mode");
4058 		goto failed_mount_wq;
4059 	}
4060 
4061 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4062 
4063 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4064 
4065 no_journal:
4066 	sbi->s_mb_cache = ext4_xattr_create_cache();
4067 	if (!sbi->s_mb_cache) {
4068 		ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4069 		goto failed_mount_wq;
4070 	}
4071 
4072 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4073 	    (blocksize != PAGE_SIZE)) {
4074 		ext4_msg(sb, KERN_ERR,
4075 			 "Unsupported blocksize for fs encryption");
4076 		goto failed_mount_wq;
4077 	}
4078 
4079 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4080 	    !ext4_has_feature_encrypt(sb)) {
4081 		ext4_set_feature_encrypt(sb);
4082 		ext4_commit_super(sb, 1);
4083 	}
4084 
4085 	/*
4086 	 * Get the # of file system overhead blocks from the
4087 	 * superblock if present.
4088 	 */
4089 	if (es->s_overhead_clusters)
4090 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4091 	else {
4092 		err = ext4_calculate_overhead(sb);
4093 		if (err)
4094 			goto failed_mount_wq;
4095 	}
4096 
4097 	/*
4098 	 * The maximum number of concurrent works can be high and
4099 	 * concurrency isn't really necessary.  Limit it to 1.
4100 	 */
4101 	EXT4_SB(sb)->rsv_conversion_wq =
4102 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4103 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4104 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4105 		ret = -ENOMEM;
4106 		goto failed_mount4;
4107 	}
4108 
4109 	/*
4110 	 * The jbd2_journal_load will have done any necessary log recovery,
4111 	 * so we can safely mount the rest of the filesystem now.
4112 	 */
4113 
4114 	root = ext4_iget(sb, EXT4_ROOT_INO);
4115 	if (IS_ERR(root)) {
4116 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4117 		ret = PTR_ERR(root);
4118 		root = NULL;
4119 		goto failed_mount4;
4120 	}
4121 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4122 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4123 		iput(root);
4124 		goto failed_mount4;
4125 	}
4126 	sb->s_root = d_make_root(root);
4127 	if (!sb->s_root) {
4128 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4129 		ret = -ENOMEM;
4130 		goto failed_mount4;
4131 	}
4132 
4133 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4134 		sb->s_flags |= MS_RDONLY;
4135 
4136 	/* determine the minimum size of new large inodes, if present */
4137 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4138 	    sbi->s_want_extra_isize == 0) {
4139 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4140 						     EXT4_GOOD_OLD_INODE_SIZE;
4141 		if (ext4_has_feature_extra_isize(sb)) {
4142 			if (sbi->s_want_extra_isize <
4143 			    le16_to_cpu(es->s_want_extra_isize))
4144 				sbi->s_want_extra_isize =
4145 					le16_to_cpu(es->s_want_extra_isize);
4146 			if (sbi->s_want_extra_isize <
4147 			    le16_to_cpu(es->s_min_extra_isize))
4148 				sbi->s_want_extra_isize =
4149 					le16_to_cpu(es->s_min_extra_isize);
4150 		}
4151 	}
4152 	/* Check if enough inode space is available */
4153 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4154 							sbi->s_inode_size) {
4155 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4156 						       EXT4_GOOD_OLD_INODE_SIZE;
4157 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4158 			 "available");
4159 	}
4160 
4161 	ext4_set_resv_clusters(sb);
4162 
4163 	err = ext4_setup_system_zone(sb);
4164 	if (err) {
4165 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4166 			 "zone (%d)", err);
4167 		goto failed_mount4a;
4168 	}
4169 
4170 	ext4_ext_init(sb);
4171 	err = ext4_mb_init(sb);
4172 	if (err) {
4173 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4174 			 err);
4175 		goto failed_mount5;
4176 	}
4177 
4178 	block = ext4_count_free_clusters(sb);
4179 	ext4_free_blocks_count_set(sbi->s_es,
4180 				   EXT4_C2B(sbi, block));
4181 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4182 				  GFP_KERNEL);
4183 	if (!err) {
4184 		unsigned long freei = ext4_count_free_inodes(sb);
4185 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4186 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4187 					  GFP_KERNEL);
4188 	}
4189 	if (!err)
4190 		err = percpu_counter_init(&sbi->s_dirs_counter,
4191 					  ext4_count_dirs(sb), GFP_KERNEL);
4192 	if (!err)
4193 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4194 					  GFP_KERNEL);
4195 	if (!err)
4196 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4197 
4198 	if (err) {
4199 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4200 		goto failed_mount6;
4201 	}
4202 
4203 	if (ext4_has_feature_flex_bg(sb))
4204 		if (!ext4_fill_flex_info(sb)) {
4205 			ext4_msg(sb, KERN_ERR,
4206 			       "unable to initialize "
4207 			       "flex_bg meta info!");
4208 			goto failed_mount6;
4209 		}
4210 
4211 	err = ext4_register_li_request(sb, first_not_zeroed);
4212 	if (err)
4213 		goto failed_mount6;
4214 
4215 	err = ext4_register_sysfs(sb);
4216 	if (err)
4217 		goto failed_mount7;
4218 
4219 #ifdef CONFIG_QUOTA
4220 	/* Enable quota usage during mount. */
4221 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4222 		err = ext4_enable_quotas(sb);
4223 		if (err)
4224 			goto failed_mount8;
4225 	}
4226 #endif  /* CONFIG_QUOTA */
4227 
4228 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4229 	ext4_orphan_cleanup(sb, es);
4230 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4231 	if (needs_recovery) {
4232 		ext4_msg(sb, KERN_INFO, "recovery complete");
4233 		ext4_mark_recovery_complete(sb, es);
4234 	}
4235 	if (EXT4_SB(sb)->s_journal) {
4236 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4237 			descr = " journalled data mode";
4238 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4239 			descr = " ordered data mode";
4240 		else
4241 			descr = " writeback data mode";
4242 	} else
4243 		descr = "out journal";
4244 
4245 	if (test_opt(sb, DISCARD)) {
4246 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4247 		if (!blk_queue_discard(q))
4248 			ext4_msg(sb, KERN_WARNING,
4249 				 "mounting with \"discard\" option, but "
4250 				 "the device does not support discard");
4251 	}
4252 
4253 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4254 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4255 			 "Opts: %.*s%s%s", descr,
4256 			 (int) sizeof(sbi->s_es->s_mount_opts),
4257 			 sbi->s_es->s_mount_opts,
4258 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4259 
4260 	if (es->s_error_count)
4261 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4262 
4263 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4264 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4265 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4266 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4267 
4268 	kfree(orig_data);
4269 	return 0;
4270 
4271 cantfind_ext4:
4272 	if (!silent)
4273 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4274 	goto failed_mount;
4275 
4276 #ifdef CONFIG_QUOTA
4277 failed_mount8:
4278 	ext4_unregister_sysfs(sb);
4279 #endif
4280 failed_mount7:
4281 	ext4_unregister_li_request(sb);
4282 failed_mount6:
4283 	ext4_mb_release(sb);
4284 	if (sbi->s_flex_groups)
4285 		kvfree(sbi->s_flex_groups);
4286 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4287 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4288 	percpu_counter_destroy(&sbi->s_dirs_counter);
4289 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4290 failed_mount5:
4291 	ext4_ext_release(sb);
4292 	ext4_release_system_zone(sb);
4293 failed_mount4a:
4294 	dput(sb->s_root);
4295 	sb->s_root = NULL;
4296 failed_mount4:
4297 	ext4_msg(sb, KERN_ERR, "mount failed");
4298 	if (EXT4_SB(sb)->rsv_conversion_wq)
4299 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4300 failed_mount_wq:
4301 	if (sbi->s_mb_cache) {
4302 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
4303 		sbi->s_mb_cache = NULL;
4304 	}
4305 	if (sbi->s_journal) {
4306 		jbd2_journal_destroy(sbi->s_journal);
4307 		sbi->s_journal = NULL;
4308 	}
4309 failed_mount3a:
4310 	ext4_es_unregister_shrinker(sbi);
4311 failed_mount3:
4312 	del_timer_sync(&sbi->s_err_report);
4313 	if (sbi->s_mmp_tsk)
4314 		kthread_stop(sbi->s_mmp_tsk);
4315 failed_mount2:
4316 	for (i = 0; i < db_count; i++)
4317 		brelse(sbi->s_group_desc[i]);
4318 	kvfree(sbi->s_group_desc);
4319 failed_mount:
4320 	if (sbi->s_chksum_driver)
4321 		crypto_free_shash(sbi->s_chksum_driver);
4322 #ifdef CONFIG_QUOTA
4323 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4324 		kfree(sbi->s_qf_names[i]);
4325 #endif
4326 	ext4_blkdev_remove(sbi);
4327 	brelse(bh);
4328 out_fail:
4329 	sb->s_fs_info = NULL;
4330 	kfree(sbi->s_blockgroup_lock);
4331 out_free_base:
4332 	kfree(sbi);
4333 	kfree(orig_data);
4334 	return err ? err : ret;
4335 }
4336 
4337 /*
4338  * Setup any per-fs journal parameters now.  We'll do this both on
4339  * initial mount, once the journal has been initialised but before we've
4340  * done any recovery; and again on any subsequent remount.
4341  */
4342 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4343 {
4344 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4345 
4346 	journal->j_commit_interval = sbi->s_commit_interval;
4347 	journal->j_min_batch_time = sbi->s_min_batch_time;
4348 	journal->j_max_batch_time = sbi->s_max_batch_time;
4349 
4350 	write_lock(&journal->j_state_lock);
4351 	if (test_opt(sb, BARRIER))
4352 		journal->j_flags |= JBD2_BARRIER;
4353 	else
4354 		journal->j_flags &= ~JBD2_BARRIER;
4355 	if (test_opt(sb, DATA_ERR_ABORT))
4356 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4357 	else
4358 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4359 	write_unlock(&journal->j_state_lock);
4360 }
4361 
4362 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4363 					     unsigned int journal_inum)
4364 {
4365 	struct inode *journal_inode;
4366 
4367 	/*
4368 	 * Test for the existence of a valid inode on disk.  Bad things
4369 	 * happen if we iget() an unused inode, as the subsequent iput()
4370 	 * will try to delete it.
4371 	 */
4372 	journal_inode = ext4_iget(sb, journal_inum);
4373 	if (IS_ERR(journal_inode)) {
4374 		ext4_msg(sb, KERN_ERR, "no journal found");
4375 		return NULL;
4376 	}
4377 	if (!journal_inode->i_nlink) {
4378 		make_bad_inode(journal_inode);
4379 		iput(journal_inode);
4380 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4381 		return NULL;
4382 	}
4383 
4384 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4385 		  journal_inode, journal_inode->i_size);
4386 	if (!S_ISREG(journal_inode->i_mode)) {
4387 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4388 		iput(journal_inode);
4389 		return NULL;
4390 	}
4391 	return journal_inode;
4392 }
4393 
4394 static journal_t *ext4_get_journal(struct super_block *sb,
4395 				   unsigned int journal_inum)
4396 {
4397 	struct inode *journal_inode;
4398 	journal_t *journal;
4399 
4400 	BUG_ON(!ext4_has_feature_journal(sb));
4401 
4402 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4403 	if (!journal_inode)
4404 		return NULL;
4405 
4406 	journal = jbd2_journal_init_inode(journal_inode);
4407 	if (!journal) {
4408 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4409 		iput(journal_inode);
4410 		return NULL;
4411 	}
4412 	journal->j_private = sb;
4413 	ext4_init_journal_params(sb, journal);
4414 	return journal;
4415 }
4416 
4417 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4418 				       dev_t j_dev)
4419 {
4420 	struct buffer_head *bh;
4421 	journal_t *journal;
4422 	ext4_fsblk_t start;
4423 	ext4_fsblk_t len;
4424 	int hblock, blocksize;
4425 	ext4_fsblk_t sb_block;
4426 	unsigned long offset;
4427 	struct ext4_super_block *es;
4428 	struct block_device *bdev;
4429 
4430 	BUG_ON(!ext4_has_feature_journal(sb));
4431 
4432 	bdev = ext4_blkdev_get(j_dev, sb);
4433 	if (bdev == NULL)
4434 		return NULL;
4435 
4436 	blocksize = sb->s_blocksize;
4437 	hblock = bdev_logical_block_size(bdev);
4438 	if (blocksize < hblock) {
4439 		ext4_msg(sb, KERN_ERR,
4440 			"blocksize too small for journal device");
4441 		goto out_bdev;
4442 	}
4443 
4444 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4445 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4446 	set_blocksize(bdev, blocksize);
4447 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4448 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4449 		       "external journal");
4450 		goto out_bdev;
4451 	}
4452 
4453 	es = (struct ext4_super_block *) (bh->b_data + offset);
4454 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4455 	    !(le32_to_cpu(es->s_feature_incompat) &
4456 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4457 		ext4_msg(sb, KERN_ERR, "external journal has "
4458 					"bad superblock");
4459 		brelse(bh);
4460 		goto out_bdev;
4461 	}
4462 
4463 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4464 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4465 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4466 		ext4_msg(sb, KERN_ERR, "external journal has "
4467 				       "corrupt superblock");
4468 		brelse(bh);
4469 		goto out_bdev;
4470 	}
4471 
4472 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4473 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4474 		brelse(bh);
4475 		goto out_bdev;
4476 	}
4477 
4478 	len = ext4_blocks_count(es);
4479 	start = sb_block + 1;
4480 	brelse(bh);	/* we're done with the superblock */
4481 
4482 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4483 					start, len, blocksize);
4484 	if (!journal) {
4485 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4486 		goto out_bdev;
4487 	}
4488 	journal->j_private = sb;
4489 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4490 	wait_on_buffer(journal->j_sb_buffer);
4491 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4492 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4493 		goto out_journal;
4494 	}
4495 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4496 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4497 					"user (unsupported) - %d",
4498 			be32_to_cpu(journal->j_superblock->s_nr_users));
4499 		goto out_journal;
4500 	}
4501 	EXT4_SB(sb)->journal_bdev = bdev;
4502 	ext4_init_journal_params(sb, journal);
4503 	return journal;
4504 
4505 out_journal:
4506 	jbd2_journal_destroy(journal);
4507 out_bdev:
4508 	ext4_blkdev_put(bdev);
4509 	return NULL;
4510 }
4511 
4512 static int ext4_load_journal(struct super_block *sb,
4513 			     struct ext4_super_block *es,
4514 			     unsigned long journal_devnum)
4515 {
4516 	journal_t *journal;
4517 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4518 	dev_t journal_dev;
4519 	int err = 0;
4520 	int really_read_only;
4521 
4522 	BUG_ON(!ext4_has_feature_journal(sb));
4523 
4524 	if (journal_devnum &&
4525 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4526 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4527 			"numbers have changed");
4528 		journal_dev = new_decode_dev(journal_devnum);
4529 	} else
4530 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4531 
4532 	really_read_only = bdev_read_only(sb->s_bdev);
4533 
4534 	/*
4535 	 * Are we loading a blank journal or performing recovery after a
4536 	 * crash?  For recovery, we need to check in advance whether we
4537 	 * can get read-write access to the device.
4538 	 */
4539 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4540 		if (sb->s_flags & MS_RDONLY) {
4541 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4542 					"required on readonly filesystem");
4543 			if (really_read_only) {
4544 				ext4_msg(sb, KERN_ERR, "write access "
4545 					"unavailable, cannot proceed");
4546 				return -EROFS;
4547 			}
4548 			ext4_msg(sb, KERN_INFO, "write access will "
4549 			       "be enabled during recovery");
4550 		}
4551 	}
4552 
4553 	if (journal_inum && journal_dev) {
4554 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4555 		       "and inode journals!");
4556 		return -EINVAL;
4557 	}
4558 
4559 	if (journal_inum) {
4560 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4561 			return -EINVAL;
4562 	} else {
4563 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4564 			return -EINVAL;
4565 	}
4566 
4567 	if (!(journal->j_flags & JBD2_BARRIER))
4568 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4569 
4570 	if (!ext4_has_feature_journal_needs_recovery(sb))
4571 		err = jbd2_journal_wipe(journal, !really_read_only);
4572 	if (!err) {
4573 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4574 		if (save)
4575 			memcpy(save, ((char *) es) +
4576 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4577 		err = jbd2_journal_load(journal);
4578 		if (save)
4579 			memcpy(((char *) es) + EXT4_S_ERR_START,
4580 			       save, EXT4_S_ERR_LEN);
4581 		kfree(save);
4582 	}
4583 
4584 	if (err) {
4585 		ext4_msg(sb, KERN_ERR, "error loading journal");
4586 		jbd2_journal_destroy(journal);
4587 		return err;
4588 	}
4589 
4590 	EXT4_SB(sb)->s_journal = journal;
4591 	ext4_clear_journal_err(sb, es);
4592 
4593 	if (!really_read_only && journal_devnum &&
4594 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4595 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4596 
4597 		/* Make sure we flush the recovery flag to disk. */
4598 		ext4_commit_super(sb, 1);
4599 	}
4600 
4601 	return 0;
4602 }
4603 
4604 static int ext4_commit_super(struct super_block *sb, int sync)
4605 {
4606 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4607 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4608 	int error = 0;
4609 
4610 	if (!sbh || block_device_ejected(sb))
4611 		return error;
4612 	/*
4613 	 * If the file system is mounted read-only, don't update the
4614 	 * superblock write time.  This avoids updating the superblock
4615 	 * write time when we are mounting the root file system
4616 	 * read/only but we need to replay the journal; at that point,
4617 	 * for people who are east of GMT and who make their clock
4618 	 * tick in localtime for Windows bug-for-bug compatibility,
4619 	 * the clock is set in the future, and this will cause e2fsck
4620 	 * to complain and force a full file system check.
4621 	 */
4622 	if (!(sb->s_flags & MS_RDONLY))
4623 		es->s_wtime = cpu_to_le32(get_seconds());
4624 	if (sb->s_bdev->bd_part)
4625 		es->s_kbytes_written =
4626 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4627 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4628 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4629 	else
4630 		es->s_kbytes_written =
4631 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4632 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4633 		ext4_free_blocks_count_set(es,
4634 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4635 				&EXT4_SB(sb)->s_freeclusters_counter)));
4636 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4637 		es->s_free_inodes_count =
4638 			cpu_to_le32(percpu_counter_sum_positive(
4639 				&EXT4_SB(sb)->s_freeinodes_counter));
4640 	BUFFER_TRACE(sbh, "marking dirty");
4641 	ext4_superblock_csum_set(sb);
4642 	if (sync)
4643 		lock_buffer(sbh);
4644 	if (buffer_write_io_error(sbh)) {
4645 		/*
4646 		 * Oh, dear.  A previous attempt to write the
4647 		 * superblock failed.  This could happen because the
4648 		 * USB device was yanked out.  Or it could happen to
4649 		 * be a transient write error and maybe the block will
4650 		 * be remapped.  Nothing we can do but to retry the
4651 		 * write and hope for the best.
4652 		 */
4653 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4654 		       "superblock detected");
4655 		clear_buffer_write_io_error(sbh);
4656 		set_buffer_uptodate(sbh);
4657 	}
4658 	mark_buffer_dirty(sbh);
4659 	if (sync) {
4660 		unlock_buffer(sbh);
4661 		error = __sync_dirty_buffer(sbh,
4662 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4663 		if (error)
4664 			return error;
4665 
4666 		error = buffer_write_io_error(sbh);
4667 		if (error) {
4668 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4669 			       "superblock");
4670 			clear_buffer_write_io_error(sbh);
4671 			set_buffer_uptodate(sbh);
4672 		}
4673 	}
4674 	return error;
4675 }
4676 
4677 /*
4678  * Have we just finished recovery?  If so, and if we are mounting (or
4679  * remounting) the filesystem readonly, then we will end up with a
4680  * consistent fs on disk.  Record that fact.
4681  */
4682 static void ext4_mark_recovery_complete(struct super_block *sb,
4683 					struct ext4_super_block *es)
4684 {
4685 	journal_t *journal = EXT4_SB(sb)->s_journal;
4686 
4687 	if (!ext4_has_feature_journal(sb)) {
4688 		BUG_ON(journal != NULL);
4689 		return;
4690 	}
4691 	jbd2_journal_lock_updates(journal);
4692 	if (jbd2_journal_flush(journal) < 0)
4693 		goto out;
4694 
4695 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4696 	    sb->s_flags & MS_RDONLY) {
4697 		ext4_clear_feature_journal_needs_recovery(sb);
4698 		ext4_commit_super(sb, 1);
4699 	}
4700 
4701 out:
4702 	jbd2_journal_unlock_updates(journal);
4703 }
4704 
4705 /*
4706  * If we are mounting (or read-write remounting) a filesystem whose journal
4707  * has recorded an error from a previous lifetime, move that error to the
4708  * main filesystem now.
4709  */
4710 static void ext4_clear_journal_err(struct super_block *sb,
4711 				   struct ext4_super_block *es)
4712 {
4713 	journal_t *journal;
4714 	int j_errno;
4715 	const char *errstr;
4716 
4717 	BUG_ON(!ext4_has_feature_journal(sb));
4718 
4719 	journal = EXT4_SB(sb)->s_journal;
4720 
4721 	/*
4722 	 * Now check for any error status which may have been recorded in the
4723 	 * journal by a prior ext4_error() or ext4_abort()
4724 	 */
4725 
4726 	j_errno = jbd2_journal_errno(journal);
4727 	if (j_errno) {
4728 		char nbuf[16];
4729 
4730 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4731 		ext4_warning(sb, "Filesystem error recorded "
4732 			     "from previous mount: %s", errstr);
4733 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4734 
4735 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4736 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4737 		ext4_commit_super(sb, 1);
4738 
4739 		jbd2_journal_clear_err(journal);
4740 		jbd2_journal_update_sb_errno(journal);
4741 	}
4742 }
4743 
4744 /*
4745  * Force the running and committing transactions to commit,
4746  * and wait on the commit.
4747  */
4748 int ext4_force_commit(struct super_block *sb)
4749 {
4750 	journal_t *journal;
4751 
4752 	if (sb->s_flags & MS_RDONLY)
4753 		return 0;
4754 
4755 	journal = EXT4_SB(sb)->s_journal;
4756 	return ext4_journal_force_commit(journal);
4757 }
4758 
4759 static int ext4_sync_fs(struct super_block *sb, int wait)
4760 {
4761 	int ret = 0;
4762 	tid_t target;
4763 	bool needs_barrier = false;
4764 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4765 
4766 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4767 		return 0;
4768 
4769 	trace_ext4_sync_fs(sb, wait);
4770 	flush_workqueue(sbi->rsv_conversion_wq);
4771 	/*
4772 	 * Writeback quota in non-journalled quota case - journalled quota has
4773 	 * no dirty dquots
4774 	 */
4775 	dquot_writeback_dquots(sb, -1);
4776 	/*
4777 	 * Data writeback is possible w/o journal transaction, so barrier must
4778 	 * being sent at the end of the function. But we can skip it if
4779 	 * transaction_commit will do it for us.
4780 	 */
4781 	if (sbi->s_journal) {
4782 		target = jbd2_get_latest_transaction(sbi->s_journal);
4783 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4784 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4785 			needs_barrier = true;
4786 
4787 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4788 			if (wait)
4789 				ret = jbd2_log_wait_commit(sbi->s_journal,
4790 							   target);
4791 		}
4792 	} else if (wait && test_opt(sb, BARRIER))
4793 		needs_barrier = true;
4794 	if (needs_barrier) {
4795 		int err;
4796 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4797 		if (!ret)
4798 			ret = err;
4799 	}
4800 
4801 	return ret;
4802 }
4803 
4804 /*
4805  * LVM calls this function before a (read-only) snapshot is created.  This
4806  * gives us a chance to flush the journal completely and mark the fs clean.
4807  *
4808  * Note that only this function cannot bring a filesystem to be in a clean
4809  * state independently. It relies on upper layer to stop all data & metadata
4810  * modifications.
4811  */
4812 static int ext4_freeze(struct super_block *sb)
4813 {
4814 	int error = 0;
4815 	journal_t *journal;
4816 
4817 	if (sb->s_flags & MS_RDONLY)
4818 		return 0;
4819 
4820 	journal = EXT4_SB(sb)->s_journal;
4821 
4822 	if (journal) {
4823 		/* Now we set up the journal barrier. */
4824 		jbd2_journal_lock_updates(journal);
4825 
4826 		/*
4827 		 * Don't clear the needs_recovery flag if we failed to
4828 		 * flush the journal.
4829 		 */
4830 		error = jbd2_journal_flush(journal);
4831 		if (error < 0)
4832 			goto out;
4833 
4834 		/* Journal blocked and flushed, clear needs_recovery flag. */
4835 		ext4_clear_feature_journal_needs_recovery(sb);
4836 	}
4837 
4838 	error = ext4_commit_super(sb, 1);
4839 out:
4840 	if (journal)
4841 		/* we rely on upper layer to stop further updates */
4842 		jbd2_journal_unlock_updates(journal);
4843 	return error;
4844 }
4845 
4846 /*
4847  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4848  * flag here, even though the filesystem is not technically dirty yet.
4849  */
4850 static int ext4_unfreeze(struct super_block *sb)
4851 {
4852 	if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4853 		return 0;
4854 
4855 	if (EXT4_SB(sb)->s_journal) {
4856 		/* Reset the needs_recovery flag before the fs is unlocked. */
4857 		ext4_set_feature_journal_needs_recovery(sb);
4858 	}
4859 
4860 	ext4_commit_super(sb, 1);
4861 	return 0;
4862 }
4863 
4864 /*
4865  * Structure to save mount options for ext4_remount's benefit
4866  */
4867 struct ext4_mount_options {
4868 	unsigned long s_mount_opt;
4869 	unsigned long s_mount_opt2;
4870 	kuid_t s_resuid;
4871 	kgid_t s_resgid;
4872 	unsigned long s_commit_interval;
4873 	u32 s_min_batch_time, s_max_batch_time;
4874 #ifdef CONFIG_QUOTA
4875 	int s_jquota_fmt;
4876 	char *s_qf_names[EXT4_MAXQUOTAS];
4877 #endif
4878 };
4879 
4880 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4881 {
4882 	struct ext4_super_block *es;
4883 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4884 	unsigned long old_sb_flags;
4885 	struct ext4_mount_options old_opts;
4886 	int enable_quota = 0;
4887 	ext4_group_t g;
4888 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4889 	int err = 0;
4890 #ifdef CONFIG_QUOTA
4891 	int i, j;
4892 #endif
4893 	char *orig_data = kstrdup(data, GFP_KERNEL);
4894 
4895 	/* Store the original options */
4896 	old_sb_flags = sb->s_flags;
4897 	old_opts.s_mount_opt = sbi->s_mount_opt;
4898 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4899 	old_opts.s_resuid = sbi->s_resuid;
4900 	old_opts.s_resgid = sbi->s_resgid;
4901 	old_opts.s_commit_interval = sbi->s_commit_interval;
4902 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4903 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4904 #ifdef CONFIG_QUOTA
4905 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4906 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4907 		if (sbi->s_qf_names[i]) {
4908 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4909 							 GFP_KERNEL);
4910 			if (!old_opts.s_qf_names[i]) {
4911 				for (j = 0; j < i; j++)
4912 					kfree(old_opts.s_qf_names[j]);
4913 				kfree(orig_data);
4914 				return -ENOMEM;
4915 			}
4916 		} else
4917 			old_opts.s_qf_names[i] = NULL;
4918 #endif
4919 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4920 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4921 
4922 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4923 		err = -EINVAL;
4924 		goto restore_opts;
4925 	}
4926 
4927 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4928 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4929 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4930 			 "during remount not supported; ignoring");
4931 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4932 	}
4933 
4934 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4935 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4936 			ext4_msg(sb, KERN_ERR, "can't mount with "
4937 				 "both data=journal and delalloc");
4938 			err = -EINVAL;
4939 			goto restore_opts;
4940 		}
4941 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4942 			ext4_msg(sb, KERN_ERR, "can't mount with "
4943 				 "both data=journal and dioread_nolock");
4944 			err = -EINVAL;
4945 			goto restore_opts;
4946 		}
4947 		if (test_opt(sb, DAX)) {
4948 			ext4_msg(sb, KERN_ERR, "can't mount with "
4949 				 "both data=journal and dax");
4950 			err = -EINVAL;
4951 			goto restore_opts;
4952 		}
4953 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
4954 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4955 			ext4_msg(sb, KERN_ERR, "can't mount with "
4956 				"journal_async_commit in data=ordered mode");
4957 			err = -EINVAL;
4958 			goto restore_opts;
4959 		}
4960 	}
4961 
4962 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4963 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4964 			"dax flag with busy inodes while remounting");
4965 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4966 	}
4967 
4968 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4969 		ext4_abort(sb, "Abort forced by user");
4970 
4971 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4972 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4973 
4974 	es = sbi->s_es;
4975 
4976 	if (sbi->s_journal) {
4977 		ext4_init_journal_params(sb, sbi->s_journal);
4978 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4979 	}
4980 
4981 	if (*flags & MS_LAZYTIME)
4982 		sb->s_flags |= MS_LAZYTIME;
4983 
4984 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4985 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4986 			err = -EROFS;
4987 			goto restore_opts;
4988 		}
4989 
4990 		if (*flags & MS_RDONLY) {
4991 			err = sync_filesystem(sb);
4992 			if (err < 0)
4993 				goto restore_opts;
4994 			err = dquot_suspend(sb, -1);
4995 			if (err < 0)
4996 				goto restore_opts;
4997 
4998 			/*
4999 			 * First of all, the unconditional stuff we have to do
5000 			 * to disable replay of the journal when we next remount
5001 			 */
5002 			sb->s_flags |= MS_RDONLY;
5003 
5004 			/*
5005 			 * OK, test if we are remounting a valid rw partition
5006 			 * readonly, and if so set the rdonly flag and then
5007 			 * mark the partition as valid again.
5008 			 */
5009 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5010 			    (sbi->s_mount_state & EXT4_VALID_FS))
5011 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5012 
5013 			if (sbi->s_journal)
5014 				ext4_mark_recovery_complete(sb, es);
5015 		} else {
5016 			/* Make sure we can mount this feature set readwrite */
5017 			if (ext4_has_feature_readonly(sb) ||
5018 			    !ext4_feature_set_ok(sb, 0)) {
5019 				err = -EROFS;
5020 				goto restore_opts;
5021 			}
5022 			/*
5023 			 * Make sure the group descriptor checksums
5024 			 * are sane.  If they aren't, refuse to remount r/w.
5025 			 */
5026 			for (g = 0; g < sbi->s_groups_count; g++) {
5027 				struct ext4_group_desc *gdp =
5028 					ext4_get_group_desc(sb, g, NULL);
5029 
5030 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5031 					ext4_msg(sb, KERN_ERR,
5032 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5033 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5034 					       le16_to_cpu(gdp->bg_checksum));
5035 					err = -EFSBADCRC;
5036 					goto restore_opts;
5037 				}
5038 			}
5039 
5040 			/*
5041 			 * If we have an unprocessed orphan list hanging
5042 			 * around from a previously readonly bdev mount,
5043 			 * require a full umount/remount for now.
5044 			 */
5045 			if (es->s_last_orphan) {
5046 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5047 				       "remount RDWR because of unprocessed "
5048 				       "orphan inode list.  Please "
5049 				       "umount/remount instead");
5050 				err = -EINVAL;
5051 				goto restore_opts;
5052 			}
5053 
5054 			/*
5055 			 * Mounting a RDONLY partition read-write, so reread
5056 			 * and store the current valid flag.  (It may have
5057 			 * been changed by e2fsck since we originally mounted
5058 			 * the partition.)
5059 			 */
5060 			if (sbi->s_journal)
5061 				ext4_clear_journal_err(sb, es);
5062 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5063 			if (!ext4_setup_super(sb, es, 0))
5064 				sb->s_flags &= ~MS_RDONLY;
5065 			if (ext4_has_feature_mmp(sb))
5066 				if (ext4_multi_mount_protect(sb,
5067 						le64_to_cpu(es->s_mmp_block))) {
5068 					err = -EROFS;
5069 					goto restore_opts;
5070 				}
5071 			enable_quota = 1;
5072 		}
5073 	}
5074 
5075 	/*
5076 	 * Reinitialize lazy itable initialization thread based on
5077 	 * current settings
5078 	 */
5079 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5080 		ext4_unregister_li_request(sb);
5081 	else {
5082 		ext4_group_t first_not_zeroed;
5083 		first_not_zeroed = ext4_has_uninit_itable(sb);
5084 		ext4_register_li_request(sb, first_not_zeroed);
5085 	}
5086 
5087 	ext4_setup_system_zone(sb);
5088 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5089 		ext4_commit_super(sb, 1);
5090 
5091 #ifdef CONFIG_QUOTA
5092 	/* Release old quota file names */
5093 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5094 		kfree(old_opts.s_qf_names[i]);
5095 	if (enable_quota) {
5096 		if (sb_any_quota_suspended(sb))
5097 			dquot_resume(sb, -1);
5098 		else if (ext4_has_feature_quota(sb)) {
5099 			err = ext4_enable_quotas(sb);
5100 			if (err)
5101 				goto restore_opts;
5102 		}
5103 	}
5104 #endif
5105 
5106 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5107 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5108 	kfree(orig_data);
5109 	return 0;
5110 
5111 restore_opts:
5112 	sb->s_flags = old_sb_flags;
5113 	sbi->s_mount_opt = old_opts.s_mount_opt;
5114 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5115 	sbi->s_resuid = old_opts.s_resuid;
5116 	sbi->s_resgid = old_opts.s_resgid;
5117 	sbi->s_commit_interval = old_opts.s_commit_interval;
5118 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5119 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5120 #ifdef CONFIG_QUOTA
5121 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5122 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5123 		kfree(sbi->s_qf_names[i]);
5124 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5125 	}
5126 #endif
5127 	kfree(orig_data);
5128 	return err;
5129 }
5130 
5131 #ifdef CONFIG_QUOTA
5132 static int ext4_statfs_project(struct super_block *sb,
5133 			       kprojid_t projid, struct kstatfs *buf)
5134 {
5135 	struct kqid qid;
5136 	struct dquot *dquot;
5137 	u64 limit;
5138 	u64 curblock;
5139 
5140 	qid = make_kqid_projid(projid);
5141 	dquot = dqget(sb, qid);
5142 	if (IS_ERR(dquot))
5143 		return PTR_ERR(dquot);
5144 	spin_lock(&dq_data_lock);
5145 
5146 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5147 		 dquot->dq_dqb.dqb_bsoftlimit :
5148 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5149 	if (limit && buf->f_blocks > limit) {
5150 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5151 		buf->f_blocks = limit;
5152 		buf->f_bfree = buf->f_bavail =
5153 			(buf->f_blocks > curblock) ?
5154 			 (buf->f_blocks - curblock) : 0;
5155 	}
5156 
5157 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5158 		dquot->dq_dqb.dqb_isoftlimit :
5159 		dquot->dq_dqb.dqb_ihardlimit;
5160 	if (limit && buf->f_files > limit) {
5161 		buf->f_files = limit;
5162 		buf->f_ffree =
5163 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5164 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5165 	}
5166 
5167 	spin_unlock(&dq_data_lock);
5168 	dqput(dquot);
5169 	return 0;
5170 }
5171 #endif
5172 
5173 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5174 {
5175 	struct super_block *sb = dentry->d_sb;
5176 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5177 	struct ext4_super_block *es = sbi->s_es;
5178 	ext4_fsblk_t overhead = 0, resv_blocks;
5179 	u64 fsid;
5180 	s64 bfree;
5181 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5182 
5183 	if (!test_opt(sb, MINIX_DF))
5184 		overhead = sbi->s_overhead;
5185 
5186 	buf->f_type = EXT4_SUPER_MAGIC;
5187 	buf->f_bsize = sb->s_blocksize;
5188 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5189 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5190 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5191 	/* prevent underflow in case that few free space is available */
5192 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5193 	buf->f_bavail = buf->f_bfree -
5194 			(ext4_r_blocks_count(es) + resv_blocks);
5195 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5196 		buf->f_bavail = 0;
5197 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5198 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5199 	buf->f_namelen = EXT4_NAME_LEN;
5200 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5201 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5202 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5203 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5204 
5205 #ifdef CONFIG_QUOTA
5206 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5207 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5208 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5209 #endif
5210 	return 0;
5211 }
5212 
5213 /* Helper function for writing quotas on sync - we need to start transaction
5214  * before quota file is locked for write. Otherwise the are possible deadlocks:
5215  * Process 1                         Process 2
5216  * ext4_create()                     quota_sync()
5217  *   jbd2_journal_start()                  write_dquot()
5218  *   dquot_initialize()                         down(dqio_mutex)
5219  *     down(dqio_mutex)                    jbd2_journal_start()
5220  *
5221  */
5222 
5223 #ifdef CONFIG_QUOTA
5224 
5225 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5226 {
5227 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5228 }
5229 
5230 static int ext4_write_dquot(struct dquot *dquot)
5231 {
5232 	int ret, err;
5233 	handle_t *handle;
5234 	struct inode *inode;
5235 
5236 	inode = dquot_to_inode(dquot);
5237 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5238 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5239 	if (IS_ERR(handle))
5240 		return PTR_ERR(handle);
5241 	ret = dquot_commit(dquot);
5242 	err = ext4_journal_stop(handle);
5243 	if (!ret)
5244 		ret = err;
5245 	return ret;
5246 }
5247 
5248 static int ext4_acquire_dquot(struct dquot *dquot)
5249 {
5250 	int ret, err;
5251 	handle_t *handle;
5252 
5253 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5254 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5255 	if (IS_ERR(handle))
5256 		return PTR_ERR(handle);
5257 	ret = dquot_acquire(dquot);
5258 	err = ext4_journal_stop(handle);
5259 	if (!ret)
5260 		ret = err;
5261 	return ret;
5262 }
5263 
5264 static int ext4_release_dquot(struct dquot *dquot)
5265 {
5266 	int ret, err;
5267 	handle_t *handle;
5268 
5269 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5270 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5271 	if (IS_ERR(handle)) {
5272 		/* Release dquot anyway to avoid endless cycle in dqput() */
5273 		dquot_release(dquot);
5274 		return PTR_ERR(handle);
5275 	}
5276 	ret = dquot_release(dquot);
5277 	err = ext4_journal_stop(handle);
5278 	if (!ret)
5279 		ret = err;
5280 	return ret;
5281 }
5282 
5283 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5284 {
5285 	struct super_block *sb = dquot->dq_sb;
5286 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5287 
5288 	/* Are we journaling quotas? */
5289 	if (ext4_has_feature_quota(sb) ||
5290 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5291 		dquot_mark_dquot_dirty(dquot);
5292 		return ext4_write_dquot(dquot);
5293 	} else {
5294 		return dquot_mark_dquot_dirty(dquot);
5295 	}
5296 }
5297 
5298 static int ext4_write_info(struct super_block *sb, int type)
5299 {
5300 	int ret, err;
5301 	handle_t *handle;
5302 
5303 	/* Data block + inode block */
5304 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5305 	if (IS_ERR(handle))
5306 		return PTR_ERR(handle);
5307 	ret = dquot_commit_info(sb, type);
5308 	err = ext4_journal_stop(handle);
5309 	if (!ret)
5310 		ret = err;
5311 	return ret;
5312 }
5313 
5314 /*
5315  * Turn on quotas during mount time - we need to find
5316  * the quota file and such...
5317  */
5318 static int ext4_quota_on_mount(struct super_block *sb, int type)
5319 {
5320 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5321 					EXT4_SB(sb)->s_jquota_fmt, type);
5322 }
5323 
5324 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5325 {
5326 	struct ext4_inode_info *ei = EXT4_I(inode);
5327 
5328 	/* The first argument of lockdep_set_subclass has to be
5329 	 * *exactly* the same as the argument to init_rwsem() --- in
5330 	 * this case, in init_once() --- or lockdep gets unhappy
5331 	 * because the name of the lock is set using the
5332 	 * stringification of the argument to init_rwsem().
5333 	 */
5334 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5335 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5336 }
5337 
5338 /*
5339  * Standard function to be called on quota_on
5340  */
5341 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5342 			 const struct path *path)
5343 {
5344 	int err;
5345 
5346 	if (!test_opt(sb, QUOTA))
5347 		return -EINVAL;
5348 
5349 	/* Quotafile not on the same filesystem? */
5350 	if (path->dentry->d_sb != sb)
5351 		return -EXDEV;
5352 	/* Journaling quota? */
5353 	if (EXT4_SB(sb)->s_qf_names[type]) {
5354 		/* Quotafile not in fs root? */
5355 		if (path->dentry->d_parent != sb->s_root)
5356 			ext4_msg(sb, KERN_WARNING,
5357 				"Quota file not on filesystem root. "
5358 				"Journaled quota will not work");
5359 	}
5360 
5361 	/*
5362 	 * When we journal data on quota file, we have to flush journal to see
5363 	 * all updates to the file when we bypass pagecache...
5364 	 */
5365 	if (EXT4_SB(sb)->s_journal &&
5366 	    ext4_should_journal_data(d_inode(path->dentry))) {
5367 		/*
5368 		 * We don't need to lock updates but journal_flush() could
5369 		 * otherwise be livelocked...
5370 		 */
5371 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5372 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5373 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5374 		if (err)
5375 			return err;
5376 	}
5377 
5378 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5379 	err = dquot_quota_on(sb, type, format_id, path);
5380 	if (err) {
5381 		lockdep_set_quota_inode(path->dentry->d_inode,
5382 					     I_DATA_SEM_NORMAL);
5383 	} else {
5384 		struct inode *inode = d_inode(path->dentry);
5385 		handle_t *handle;
5386 
5387 		/*
5388 		 * Set inode flags to prevent userspace from messing with quota
5389 		 * files. If this fails, we return success anyway since quotas
5390 		 * are already enabled and this is not a hard failure.
5391 		 */
5392 		inode_lock(inode);
5393 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5394 		if (IS_ERR(handle))
5395 			goto unlock_inode;
5396 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5397 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5398 				S_NOATIME | S_IMMUTABLE);
5399 		ext4_mark_inode_dirty(handle, inode);
5400 		ext4_journal_stop(handle);
5401 	unlock_inode:
5402 		inode_unlock(inode);
5403 	}
5404 	return err;
5405 }
5406 
5407 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5408 			     unsigned int flags)
5409 {
5410 	int err;
5411 	struct inode *qf_inode;
5412 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5413 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5414 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5415 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5416 	};
5417 
5418 	BUG_ON(!ext4_has_feature_quota(sb));
5419 
5420 	if (!qf_inums[type])
5421 		return -EPERM;
5422 
5423 	qf_inode = ext4_iget(sb, qf_inums[type]);
5424 	if (IS_ERR(qf_inode)) {
5425 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5426 		return PTR_ERR(qf_inode);
5427 	}
5428 
5429 	/* Don't account quota for quota files to avoid recursion */
5430 	qf_inode->i_flags |= S_NOQUOTA;
5431 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5432 	err = dquot_enable(qf_inode, type, format_id, flags);
5433 	iput(qf_inode);
5434 	if (err)
5435 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5436 
5437 	return err;
5438 }
5439 
5440 /* Enable usage tracking for all quota types. */
5441 static int ext4_enable_quotas(struct super_block *sb)
5442 {
5443 	int type, err = 0;
5444 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5445 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5446 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5447 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5448 	};
5449 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5450 		test_opt(sb, USRQUOTA),
5451 		test_opt(sb, GRPQUOTA),
5452 		test_opt(sb, PRJQUOTA),
5453 	};
5454 
5455 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5456 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5457 		if (qf_inums[type]) {
5458 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5459 				DQUOT_USAGE_ENABLED |
5460 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5461 			if (err) {
5462 				ext4_warning(sb,
5463 					"Failed to enable quota tracking "
5464 					"(type=%d, err=%d). Please run "
5465 					"e2fsck to fix.", type, err);
5466 				return err;
5467 			}
5468 		}
5469 	}
5470 	return 0;
5471 }
5472 
5473 static int ext4_quota_off(struct super_block *sb, int type)
5474 {
5475 	struct inode *inode = sb_dqopt(sb)->files[type];
5476 	handle_t *handle;
5477 	int err;
5478 
5479 	/* Force all delayed allocation blocks to be allocated.
5480 	 * Caller already holds s_umount sem */
5481 	if (test_opt(sb, DELALLOC))
5482 		sync_filesystem(sb);
5483 
5484 	if (!inode || !igrab(inode))
5485 		goto out;
5486 
5487 	err = dquot_quota_off(sb, type);
5488 	if (err)
5489 		goto out_put;
5490 
5491 	inode_lock(inode);
5492 	/*
5493 	 * Update modification times of quota files when userspace can
5494 	 * start looking at them. If we fail, we return success anyway since
5495 	 * this is not a hard failure and quotas are already disabled.
5496 	 */
5497 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5498 	if (IS_ERR(handle))
5499 		goto out_unlock;
5500 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5501 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5502 	inode->i_mtime = inode->i_ctime = current_time(inode);
5503 	ext4_mark_inode_dirty(handle, inode);
5504 	ext4_journal_stop(handle);
5505 out_unlock:
5506 	inode_unlock(inode);
5507 out_put:
5508 	iput(inode);
5509 	return err;
5510 out:
5511 	return dquot_quota_off(sb, type);
5512 }
5513 
5514 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5515  * acquiring the locks... As quota files are never truncated and quota code
5516  * itself serializes the operations (and no one else should touch the files)
5517  * we don't have to be afraid of races */
5518 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5519 			       size_t len, loff_t off)
5520 {
5521 	struct inode *inode = sb_dqopt(sb)->files[type];
5522 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5523 	int offset = off & (sb->s_blocksize - 1);
5524 	int tocopy;
5525 	size_t toread;
5526 	struct buffer_head *bh;
5527 	loff_t i_size = i_size_read(inode);
5528 
5529 	if (off > i_size)
5530 		return 0;
5531 	if (off+len > i_size)
5532 		len = i_size-off;
5533 	toread = len;
5534 	while (toread > 0) {
5535 		tocopy = sb->s_blocksize - offset < toread ?
5536 				sb->s_blocksize - offset : toread;
5537 		bh = ext4_bread(NULL, inode, blk, 0);
5538 		if (IS_ERR(bh))
5539 			return PTR_ERR(bh);
5540 		if (!bh)	/* A hole? */
5541 			memset(data, 0, tocopy);
5542 		else
5543 			memcpy(data, bh->b_data+offset, tocopy);
5544 		brelse(bh);
5545 		offset = 0;
5546 		toread -= tocopy;
5547 		data += tocopy;
5548 		blk++;
5549 	}
5550 	return len;
5551 }
5552 
5553 /* Write to quotafile (we know the transaction is already started and has
5554  * enough credits) */
5555 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5556 				const char *data, size_t len, loff_t off)
5557 {
5558 	struct inode *inode = sb_dqopt(sb)->files[type];
5559 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5560 	int err, offset = off & (sb->s_blocksize - 1);
5561 	int retries = 0;
5562 	struct buffer_head *bh;
5563 	handle_t *handle = journal_current_handle();
5564 
5565 	if (EXT4_SB(sb)->s_journal && !handle) {
5566 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5567 			" cancelled because transaction is not started",
5568 			(unsigned long long)off, (unsigned long long)len);
5569 		return -EIO;
5570 	}
5571 	/*
5572 	 * Since we account only one data block in transaction credits,
5573 	 * then it is impossible to cross a block boundary.
5574 	 */
5575 	if (sb->s_blocksize - offset < len) {
5576 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5577 			" cancelled because not block aligned",
5578 			(unsigned long long)off, (unsigned long long)len);
5579 		return -EIO;
5580 	}
5581 
5582 	do {
5583 		bh = ext4_bread(handle, inode, blk,
5584 				EXT4_GET_BLOCKS_CREATE |
5585 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5586 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5587 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5588 	if (IS_ERR(bh))
5589 		return PTR_ERR(bh);
5590 	if (!bh)
5591 		goto out;
5592 	BUFFER_TRACE(bh, "get write access");
5593 	err = ext4_journal_get_write_access(handle, bh);
5594 	if (err) {
5595 		brelse(bh);
5596 		return err;
5597 	}
5598 	lock_buffer(bh);
5599 	memcpy(bh->b_data+offset, data, len);
5600 	flush_dcache_page(bh->b_page);
5601 	unlock_buffer(bh);
5602 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5603 	brelse(bh);
5604 out:
5605 	if (inode->i_size < off + len) {
5606 		i_size_write(inode, off + len);
5607 		EXT4_I(inode)->i_disksize = inode->i_size;
5608 		ext4_mark_inode_dirty(handle, inode);
5609 	}
5610 	return len;
5611 }
5612 
5613 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5614 {
5615 	const struct quota_format_ops	*ops;
5616 
5617 	if (!sb_has_quota_loaded(sb, qid->type))
5618 		return -ESRCH;
5619 	ops = sb_dqopt(sb)->ops[qid->type];
5620 	if (!ops || !ops->get_next_id)
5621 		return -ENOSYS;
5622 	return dquot_get_next_id(sb, qid);
5623 }
5624 #endif
5625 
5626 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5627 		       const char *dev_name, void *data)
5628 {
5629 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5630 }
5631 
5632 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5633 static inline void register_as_ext2(void)
5634 {
5635 	int err = register_filesystem(&ext2_fs_type);
5636 	if (err)
5637 		printk(KERN_WARNING
5638 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5639 }
5640 
5641 static inline void unregister_as_ext2(void)
5642 {
5643 	unregister_filesystem(&ext2_fs_type);
5644 }
5645 
5646 static inline int ext2_feature_set_ok(struct super_block *sb)
5647 {
5648 	if (ext4_has_unknown_ext2_incompat_features(sb))
5649 		return 0;
5650 	if (sb->s_flags & MS_RDONLY)
5651 		return 1;
5652 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5653 		return 0;
5654 	return 1;
5655 }
5656 #else
5657 static inline void register_as_ext2(void) { }
5658 static inline void unregister_as_ext2(void) { }
5659 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5660 #endif
5661 
5662 static inline void register_as_ext3(void)
5663 {
5664 	int err = register_filesystem(&ext3_fs_type);
5665 	if (err)
5666 		printk(KERN_WARNING
5667 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5668 }
5669 
5670 static inline void unregister_as_ext3(void)
5671 {
5672 	unregister_filesystem(&ext3_fs_type);
5673 }
5674 
5675 static inline int ext3_feature_set_ok(struct super_block *sb)
5676 {
5677 	if (ext4_has_unknown_ext3_incompat_features(sb))
5678 		return 0;
5679 	if (!ext4_has_feature_journal(sb))
5680 		return 0;
5681 	if (sb->s_flags & MS_RDONLY)
5682 		return 1;
5683 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5684 		return 0;
5685 	return 1;
5686 }
5687 
5688 static struct file_system_type ext4_fs_type = {
5689 	.owner		= THIS_MODULE,
5690 	.name		= "ext4",
5691 	.mount		= ext4_mount,
5692 	.kill_sb	= kill_block_super,
5693 	.fs_flags	= FS_REQUIRES_DEV,
5694 };
5695 MODULE_ALIAS_FS("ext4");
5696 
5697 /* Shared across all ext4 file systems */
5698 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5699 
5700 static int __init ext4_init_fs(void)
5701 {
5702 	int i, err;
5703 
5704 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5705 	ext4_li_info = NULL;
5706 	mutex_init(&ext4_li_mtx);
5707 
5708 	/* Build-time check for flags consistency */
5709 	ext4_check_flag_values();
5710 
5711 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5712 		init_waitqueue_head(&ext4__ioend_wq[i]);
5713 
5714 	err = ext4_init_es();
5715 	if (err)
5716 		return err;
5717 
5718 	err = ext4_init_pageio();
5719 	if (err)
5720 		goto out5;
5721 
5722 	err = ext4_init_system_zone();
5723 	if (err)
5724 		goto out4;
5725 
5726 	err = ext4_init_sysfs();
5727 	if (err)
5728 		goto out3;
5729 
5730 	err = ext4_init_mballoc();
5731 	if (err)
5732 		goto out2;
5733 	err = init_inodecache();
5734 	if (err)
5735 		goto out1;
5736 	register_as_ext3();
5737 	register_as_ext2();
5738 	err = register_filesystem(&ext4_fs_type);
5739 	if (err)
5740 		goto out;
5741 
5742 	return 0;
5743 out:
5744 	unregister_as_ext2();
5745 	unregister_as_ext3();
5746 	destroy_inodecache();
5747 out1:
5748 	ext4_exit_mballoc();
5749 out2:
5750 	ext4_exit_sysfs();
5751 out3:
5752 	ext4_exit_system_zone();
5753 out4:
5754 	ext4_exit_pageio();
5755 out5:
5756 	ext4_exit_es();
5757 
5758 	return err;
5759 }
5760 
5761 static void __exit ext4_exit_fs(void)
5762 {
5763 	ext4_destroy_lazyinit_thread();
5764 	unregister_as_ext2();
5765 	unregister_as_ext3();
5766 	unregister_filesystem(&ext4_fs_type);
5767 	destroy_inodecache();
5768 	ext4_exit_mballoc();
5769 	ext4_exit_sysfs();
5770 	ext4_exit_system_zone();
5771 	ext4_exit_pageio();
5772 	ext4_exit_es();
5773 }
5774 
5775 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5776 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5777 MODULE_LICENSE("GPL");
5778 module_init(ext4_init_fs)
5779 module_exit(ext4_exit_fs)
5780