xref: /linux/fs/ext4/super.c (revision 17b121ad0c43342bc894632f6710b894849ca372)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/cleancache.h>
43 #include <linux/uaccess.h>
44 #include <linux/iversion.h>
45 #include <linux/unicode.h>
46 #include <linux/part_stat.h>
47 #include <linux/kthread.h>
48 #include <linux/freezer.h>
49 
50 #include "ext4.h"
51 #include "ext4_extents.h"	/* Needed for trace points definition */
52 #include "ext4_jbd2.h"
53 #include "xattr.h"
54 #include "acl.h"
55 #include "mballoc.h"
56 #include "fsmap.h"
57 
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/ext4.h>
60 
61 static struct ext4_lazy_init *ext4_li_info;
62 static DEFINE_MUTEX(ext4_li_mtx);
63 static struct ratelimit_state ext4_mount_msg_ratelimit;
64 
65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
66 			     unsigned long journal_devnum);
67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
68 static void ext4_update_super(struct super_block *sb);
69 static int ext4_commit_super(struct super_block *sb);
70 static int ext4_mark_recovery_complete(struct super_block *sb,
71 					struct ext4_super_block *es);
72 static int ext4_clear_journal_err(struct super_block *sb,
73 				  struct ext4_super_block *es);
74 static int ext4_sync_fs(struct super_block *sb, int wait);
75 static int ext4_remount(struct super_block *sb, int *flags, char *data);
76 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
77 static int ext4_unfreeze(struct super_block *sb);
78 static int ext4_freeze(struct super_block *sb);
79 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
80 		       const char *dev_name, void *data);
81 static inline int ext2_feature_set_ok(struct super_block *sb);
82 static inline int ext3_feature_set_ok(struct super_block *sb);
83 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
84 static void ext4_destroy_lazyinit_thread(void);
85 static void ext4_unregister_li_request(struct super_block *sb);
86 static void ext4_clear_request_list(void);
87 static struct inode *ext4_get_journal_inode(struct super_block *sb,
88 					    unsigned int journal_inum);
89 
90 /*
91  * Lock ordering
92  *
93  * page fault path:
94  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
95  *   -> page lock -> i_data_sem (rw)
96  *
97  * buffered write path:
98  * sb_start_write -> i_mutex -> mmap_lock
99  * sb_start_write -> i_mutex -> transaction start -> page lock ->
100  *   i_data_sem (rw)
101  *
102  * truncate:
103  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
104  *   page lock
105  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
106  *   i_data_sem (rw)
107  *
108  * direct IO:
109  * sb_start_write -> i_mutex -> mmap_lock
110  * sb_start_write -> i_mutex -> 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 
144 static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags,
145 				  bh_end_io_t *end_io)
146 {
147 	/*
148 	 * buffer's verified bit is no longer valid after reading from
149 	 * disk again due to write out error, clear it to make sure we
150 	 * recheck the buffer contents.
151 	 */
152 	clear_buffer_verified(bh);
153 
154 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
155 	get_bh(bh);
156 	submit_bh(REQ_OP_READ, op_flags, bh);
157 }
158 
159 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
160 			 bh_end_io_t *end_io)
161 {
162 	BUG_ON(!buffer_locked(bh));
163 
164 	if (ext4_buffer_uptodate(bh)) {
165 		unlock_buffer(bh);
166 		return;
167 	}
168 	__ext4_read_bh(bh, op_flags, end_io);
169 }
170 
171 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
172 {
173 	BUG_ON(!buffer_locked(bh));
174 
175 	if (ext4_buffer_uptodate(bh)) {
176 		unlock_buffer(bh);
177 		return 0;
178 	}
179 
180 	__ext4_read_bh(bh, op_flags, end_io);
181 
182 	wait_on_buffer(bh);
183 	if (buffer_uptodate(bh))
184 		return 0;
185 	return -EIO;
186 }
187 
188 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
189 {
190 	if (trylock_buffer(bh)) {
191 		if (wait)
192 			return ext4_read_bh(bh, op_flags, NULL);
193 		ext4_read_bh_nowait(bh, op_flags, NULL);
194 		return 0;
195 	}
196 	if (wait) {
197 		wait_on_buffer(bh);
198 		if (buffer_uptodate(bh))
199 			return 0;
200 		return -EIO;
201 	}
202 	return 0;
203 }
204 
205 /*
206  * This works like __bread_gfp() except it uses ERR_PTR for error
207  * returns.  Currently with sb_bread it's impossible to distinguish
208  * between ENOMEM and EIO situations (since both result in a NULL
209  * return.
210  */
211 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
212 					       sector_t block, int op_flags,
213 					       gfp_t gfp)
214 {
215 	struct buffer_head *bh;
216 	int ret;
217 
218 	bh = sb_getblk_gfp(sb, block, gfp);
219 	if (bh == NULL)
220 		return ERR_PTR(-ENOMEM);
221 	if (ext4_buffer_uptodate(bh))
222 		return bh;
223 
224 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
225 	if (ret) {
226 		put_bh(bh);
227 		return ERR_PTR(ret);
228 	}
229 	return bh;
230 }
231 
232 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
233 				   int op_flags)
234 {
235 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
236 }
237 
238 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
239 					    sector_t block)
240 {
241 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
242 }
243 
244 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
245 {
246 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
247 
248 	if (likely(bh)) {
249 		ext4_read_bh_lock(bh, REQ_RAHEAD, false);
250 		brelse(bh);
251 	}
252 }
253 
254 static int ext4_verify_csum_type(struct super_block *sb,
255 				 struct ext4_super_block *es)
256 {
257 	if (!ext4_has_feature_metadata_csum(sb))
258 		return 1;
259 
260 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
261 }
262 
263 static __le32 ext4_superblock_csum(struct super_block *sb,
264 				   struct ext4_super_block *es)
265 {
266 	struct ext4_sb_info *sbi = EXT4_SB(sb);
267 	int offset = offsetof(struct ext4_super_block, s_checksum);
268 	__u32 csum;
269 
270 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
271 
272 	return cpu_to_le32(csum);
273 }
274 
275 static int ext4_superblock_csum_verify(struct super_block *sb,
276 				       struct ext4_super_block *es)
277 {
278 	if (!ext4_has_metadata_csum(sb))
279 		return 1;
280 
281 	return es->s_checksum == ext4_superblock_csum(sb, es);
282 }
283 
284 void ext4_superblock_csum_set(struct super_block *sb)
285 {
286 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
287 
288 	if (!ext4_has_metadata_csum(sb))
289 		return;
290 
291 	es->s_checksum = ext4_superblock_csum(sb, es);
292 }
293 
294 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
295 			       struct ext4_group_desc *bg)
296 {
297 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
298 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
299 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
300 }
301 
302 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
303 			       struct ext4_group_desc *bg)
304 {
305 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
306 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
307 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
308 }
309 
310 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
311 			      struct ext4_group_desc *bg)
312 {
313 	return le32_to_cpu(bg->bg_inode_table_lo) |
314 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
315 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
316 }
317 
318 __u32 ext4_free_group_clusters(struct super_block *sb,
319 			       struct ext4_group_desc *bg)
320 {
321 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
322 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
323 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
324 }
325 
326 __u32 ext4_free_inodes_count(struct super_block *sb,
327 			      struct ext4_group_desc *bg)
328 {
329 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
330 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
331 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
332 }
333 
334 __u32 ext4_used_dirs_count(struct super_block *sb,
335 			      struct ext4_group_desc *bg)
336 {
337 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
338 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
339 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
340 }
341 
342 __u32 ext4_itable_unused_count(struct super_block *sb,
343 			      struct ext4_group_desc *bg)
344 {
345 	return le16_to_cpu(bg->bg_itable_unused_lo) |
346 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
347 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
348 }
349 
350 void ext4_block_bitmap_set(struct super_block *sb,
351 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
352 {
353 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
354 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
355 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
356 }
357 
358 void ext4_inode_bitmap_set(struct super_block *sb,
359 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
360 {
361 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
362 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
363 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
364 }
365 
366 void ext4_inode_table_set(struct super_block *sb,
367 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
368 {
369 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
370 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
371 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
372 }
373 
374 void ext4_free_group_clusters_set(struct super_block *sb,
375 				  struct ext4_group_desc *bg, __u32 count)
376 {
377 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
378 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
379 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
380 }
381 
382 void ext4_free_inodes_set(struct super_block *sb,
383 			  struct ext4_group_desc *bg, __u32 count)
384 {
385 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
386 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
387 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
388 }
389 
390 void ext4_used_dirs_set(struct super_block *sb,
391 			  struct ext4_group_desc *bg, __u32 count)
392 {
393 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
394 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
395 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
396 }
397 
398 void ext4_itable_unused_set(struct super_block *sb,
399 			  struct ext4_group_desc *bg, __u32 count)
400 {
401 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
402 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
403 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
404 }
405 
406 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
407 {
408 	now = clamp_val(now, 0, (1ull << 40) - 1);
409 
410 	*lo = cpu_to_le32(lower_32_bits(now));
411 	*hi = upper_32_bits(now);
412 }
413 
414 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
415 {
416 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
417 }
418 #define ext4_update_tstamp(es, tstamp) \
419 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
420 			     ktime_get_real_seconds())
421 #define ext4_get_tstamp(es, tstamp) \
422 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
423 
424 /*
425  * The del_gendisk() function uninitializes the disk-specific data
426  * structures, including the bdi structure, without telling anyone
427  * else.  Once this happens, any attempt to call mark_buffer_dirty()
428  * (for example, by ext4_commit_super), will cause a kernel OOPS.
429  * This is a kludge to prevent these oops until we can put in a proper
430  * hook in del_gendisk() to inform the VFS and file system layers.
431  */
432 static int block_device_ejected(struct super_block *sb)
433 {
434 	struct inode *bd_inode = sb->s_bdev->bd_inode;
435 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
436 
437 	return bdi->dev == NULL;
438 }
439 
440 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
441 {
442 	struct super_block		*sb = journal->j_private;
443 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
444 	int				error = is_journal_aborted(journal);
445 	struct ext4_journal_cb_entry	*jce;
446 
447 	BUG_ON(txn->t_state == T_FINISHED);
448 
449 	ext4_process_freed_data(sb, txn->t_tid);
450 
451 	spin_lock(&sbi->s_md_lock);
452 	while (!list_empty(&txn->t_private_list)) {
453 		jce = list_entry(txn->t_private_list.next,
454 				 struct ext4_journal_cb_entry, jce_list);
455 		list_del_init(&jce->jce_list);
456 		spin_unlock(&sbi->s_md_lock);
457 		jce->jce_func(sb, jce, error);
458 		spin_lock(&sbi->s_md_lock);
459 	}
460 	spin_unlock(&sbi->s_md_lock);
461 }
462 
463 /*
464  * This writepage callback for write_cache_pages()
465  * takes care of a few cases after page cleaning.
466  *
467  * write_cache_pages() already checks for dirty pages
468  * and calls clear_page_dirty_for_io(), which we want,
469  * to write protect the pages.
470  *
471  * However, we may have to redirty a page (see below.)
472  */
473 static int ext4_journalled_writepage_callback(struct page *page,
474 					      struct writeback_control *wbc,
475 					      void *data)
476 {
477 	transaction_t *transaction = (transaction_t *) data;
478 	struct buffer_head *bh, *head;
479 	struct journal_head *jh;
480 
481 	bh = head = page_buffers(page);
482 	do {
483 		/*
484 		 * We have to redirty a page in these cases:
485 		 * 1) If buffer is dirty, it means the page was dirty because it
486 		 * contains a buffer that needs checkpointing. So the dirty bit
487 		 * needs to be preserved so that checkpointing writes the buffer
488 		 * properly.
489 		 * 2) If buffer is not part of the committing transaction
490 		 * (we may have just accidentally come across this buffer because
491 		 * inode range tracking is not exact) or if the currently running
492 		 * transaction already contains this buffer as well, dirty bit
493 		 * needs to be preserved so that the buffer gets writeprotected
494 		 * properly on running transaction's commit.
495 		 */
496 		jh = bh2jh(bh);
497 		if (buffer_dirty(bh) ||
498 		    (jh && (jh->b_transaction != transaction ||
499 			    jh->b_next_transaction))) {
500 			redirty_page_for_writepage(wbc, page);
501 			goto out;
502 		}
503 	} while ((bh = bh->b_this_page) != head);
504 
505 out:
506 	return AOP_WRITEPAGE_ACTIVATE;
507 }
508 
509 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
510 {
511 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
512 	struct writeback_control wbc = {
513 		.sync_mode =  WB_SYNC_ALL,
514 		.nr_to_write = LONG_MAX,
515 		.range_start = jinode->i_dirty_start,
516 		.range_end = jinode->i_dirty_end,
517         };
518 
519 	return write_cache_pages(mapping, &wbc,
520 				 ext4_journalled_writepage_callback,
521 				 jinode->i_transaction);
522 }
523 
524 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
525 {
526 	int ret;
527 
528 	if (ext4_should_journal_data(jinode->i_vfs_inode))
529 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
530 	else
531 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
532 
533 	return ret;
534 }
535 
536 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
537 {
538 	int ret = 0;
539 
540 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
541 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
542 
543 	return ret;
544 }
545 
546 static bool system_going_down(void)
547 {
548 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
549 		|| system_state == SYSTEM_RESTART;
550 }
551 
552 struct ext4_err_translation {
553 	int code;
554 	int errno;
555 };
556 
557 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
558 
559 static struct ext4_err_translation err_translation[] = {
560 	EXT4_ERR_TRANSLATE(EIO),
561 	EXT4_ERR_TRANSLATE(ENOMEM),
562 	EXT4_ERR_TRANSLATE(EFSBADCRC),
563 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
564 	EXT4_ERR_TRANSLATE(ENOSPC),
565 	EXT4_ERR_TRANSLATE(ENOKEY),
566 	EXT4_ERR_TRANSLATE(EROFS),
567 	EXT4_ERR_TRANSLATE(EFBIG),
568 	EXT4_ERR_TRANSLATE(EEXIST),
569 	EXT4_ERR_TRANSLATE(ERANGE),
570 	EXT4_ERR_TRANSLATE(EOVERFLOW),
571 	EXT4_ERR_TRANSLATE(EBUSY),
572 	EXT4_ERR_TRANSLATE(ENOTDIR),
573 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
574 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
575 	EXT4_ERR_TRANSLATE(EFAULT),
576 };
577 
578 static int ext4_errno_to_code(int errno)
579 {
580 	int i;
581 
582 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
583 		if (err_translation[i].errno == errno)
584 			return err_translation[i].code;
585 	return EXT4_ERR_UNKNOWN;
586 }
587 
588 static void save_error_info(struct super_block *sb, int error,
589 			    __u32 ino, __u64 block,
590 			    const char *func, unsigned int line)
591 {
592 	struct ext4_sb_info *sbi = EXT4_SB(sb);
593 
594 	/* We default to EFSCORRUPTED error... */
595 	if (error == 0)
596 		error = EFSCORRUPTED;
597 
598 	spin_lock(&sbi->s_error_lock);
599 	sbi->s_add_error_count++;
600 	sbi->s_last_error_code = error;
601 	sbi->s_last_error_line = line;
602 	sbi->s_last_error_ino = ino;
603 	sbi->s_last_error_block = block;
604 	sbi->s_last_error_func = func;
605 	sbi->s_last_error_time = ktime_get_real_seconds();
606 	if (!sbi->s_first_error_time) {
607 		sbi->s_first_error_code = error;
608 		sbi->s_first_error_line = line;
609 		sbi->s_first_error_ino = ino;
610 		sbi->s_first_error_block = block;
611 		sbi->s_first_error_func = func;
612 		sbi->s_first_error_time = sbi->s_last_error_time;
613 	}
614 	spin_unlock(&sbi->s_error_lock);
615 }
616 
617 /* Deal with the reporting of failure conditions on a filesystem such as
618  * inconsistencies detected or read IO failures.
619  *
620  * On ext2, we can store the error state of the filesystem in the
621  * superblock.  That is not possible on ext4, because we may have other
622  * write ordering constraints on the superblock which prevent us from
623  * writing it out straight away; and given that the journal is about to
624  * be aborted, we can't rely on the current, or future, transactions to
625  * write out the superblock safely.
626  *
627  * We'll just use the jbd2_journal_abort() error code to record an error in
628  * the journal instead.  On recovery, the journal will complain about
629  * that error until we've noted it down and cleared it.
630  *
631  * If force_ro is set, we unconditionally force the filesystem into an
632  * ABORT|READONLY state, unless the error response on the fs has been set to
633  * panic in which case we take the easy way out and panic immediately. This is
634  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
635  * at a critical moment in log management.
636  */
637 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
638 			      __u32 ino, __u64 block,
639 			      const char *func, unsigned int line)
640 {
641 	journal_t *journal = EXT4_SB(sb)->s_journal;
642 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
643 
644 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
645 	if (test_opt(sb, WARN_ON_ERROR))
646 		WARN_ON_ONCE(1);
647 
648 	if (!continue_fs && !sb_rdonly(sb)) {
649 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
650 		if (journal)
651 			jbd2_journal_abort(journal, -EIO);
652 	}
653 
654 	if (!bdev_read_only(sb->s_bdev)) {
655 		save_error_info(sb, error, ino, block, func, line);
656 		/*
657 		 * In case the fs should keep running, we need to writeout
658 		 * superblock through the journal. Due to lock ordering
659 		 * constraints, it may not be safe to do it right here so we
660 		 * defer superblock flushing to a workqueue.
661 		 */
662 		if (continue_fs)
663 			schedule_work(&EXT4_SB(sb)->s_error_work);
664 		else
665 			ext4_commit_super(sb);
666 	}
667 
668 	/*
669 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
670 	 * could panic during 'reboot -f' as the underlying device got already
671 	 * disabled.
672 	 */
673 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
674 		panic("EXT4-fs (device %s): panic forced after error\n",
675 			sb->s_id);
676 	}
677 
678 	if (sb_rdonly(sb) || continue_fs)
679 		return;
680 
681 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
682 	/*
683 	 * Make sure updated value of ->s_mount_flags will be visible before
684 	 * ->s_flags update
685 	 */
686 	smp_wmb();
687 	sb->s_flags |= SB_RDONLY;
688 }
689 
690 static void flush_stashed_error_work(struct work_struct *work)
691 {
692 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
693 						s_error_work);
694 	journal_t *journal = sbi->s_journal;
695 	handle_t *handle;
696 
697 	/*
698 	 * If the journal is still running, we have to write out superblock
699 	 * through the journal to avoid collisions of other journalled sb
700 	 * updates.
701 	 *
702 	 * We use directly jbd2 functions here to avoid recursing back into
703 	 * ext4 error handling code during handling of previous errors.
704 	 */
705 	if (!sb_rdonly(sbi->s_sb) && journal) {
706 		struct buffer_head *sbh = sbi->s_sbh;
707 		handle = jbd2_journal_start(journal, 1);
708 		if (IS_ERR(handle))
709 			goto write_directly;
710 		if (jbd2_journal_get_write_access(handle, sbh)) {
711 			jbd2_journal_stop(handle);
712 			goto write_directly;
713 		}
714 		ext4_update_super(sbi->s_sb);
715 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
716 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
717 				 "superblock detected");
718 			clear_buffer_write_io_error(sbh);
719 			set_buffer_uptodate(sbh);
720 		}
721 
722 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
723 			jbd2_journal_stop(handle);
724 			goto write_directly;
725 		}
726 		jbd2_journal_stop(handle);
727 		ext4_notify_error_sysfs(sbi);
728 		return;
729 	}
730 write_directly:
731 	/*
732 	 * Write through journal failed. Write sb directly to get error info
733 	 * out and hope for the best.
734 	 */
735 	ext4_commit_super(sbi->s_sb);
736 	ext4_notify_error_sysfs(sbi);
737 }
738 
739 #define ext4_error_ratelimit(sb)					\
740 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
741 			     "EXT4-fs error")
742 
743 void __ext4_error(struct super_block *sb, const char *function,
744 		  unsigned int line, bool force_ro, int error, __u64 block,
745 		  const char *fmt, ...)
746 {
747 	struct va_format vaf;
748 	va_list args;
749 
750 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
751 		return;
752 
753 	trace_ext4_error(sb, function, line);
754 	if (ext4_error_ratelimit(sb)) {
755 		va_start(args, fmt);
756 		vaf.fmt = fmt;
757 		vaf.va = &args;
758 		printk(KERN_CRIT
759 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
760 		       sb->s_id, function, line, current->comm, &vaf);
761 		va_end(args);
762 	}
763 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
764 }
765 
766 void __ext4_error_inode(struct inode *inode, const char *function,
767 			unsigned int line, ext4_fsblk_t block, int error,
768 			const char *fmt, ...)
769 {
770 	va_list args;
771 	struct va_format vaf;
772 
773 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
774 		return;
775 
776 	trace_ext4_error(inode->i_sb, function, line);
777 	if (ext4_error_ratelimit(inode->i_sb)) {
778 		va_start(args, fmt);
779 		vaf.fmt = fmt;
780 		vaf.va = &args;
781 		if (block)
782 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
783 			       "inode #%lu: block %llu: comm %s: %pV\n",
784 			       inode->i_sb->s_id, function, line, inode->i_ino,
785 			       block, current->comm, &vaf);
786 		else
787 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
788 			       "inode #%lu: comm %s: %pV\n",
789 			       inode->i_sb->s_id, function, line, inode->i_ino,
790 			       current->comm, &vaf);
791 		va_end(args);
792 	}
793 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
794 			  function, line);
795 }
796 
797 void __ext4_error_file(struct file *file, const char *function,
798 		       unsigned int line, ext4_fsblk_t block,
799 		       const char *fmt, ...)
800 {
801 	va_list args;
802 	struct va_format vaf;
803 	struct inode *inode = file_inode(file);
804 	char pathname[80], *path;
805 
806 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
807 		return;
808 
809 	trace_ext4_error(inode->i_sb, function, line);
810 	if (ext4_error_ratelimit(inode->i_sb)) {
811 		path = file_path(file, pathname, sizeof(pathname));
812 		if (IS_ERR(path))
813 			path = "(unknown)";
814 		va_start(args, fmt);
815 		vaf.fmt = fmt;
816 		vaf.va = &args;
817 		if (block)
818 			printk(KERN_CRIT
819 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
820 			       "block %llu: comm %s: path %s: %pV\n",
821 			       inode->i_sb->s_id, function, line, inode->i_ino,
822 			       block, current->comm, path, &vaf);
823 		else
824 			printk(KERN_CRIT
825 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
826 			       "comm %s: path %s: %pV\n",
827 			       inode->i_sb->s_id, function, line, inode->i_ino,
828 			       current->comm, path, &vaf);
829 		va_end(args);
830 	}
831 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
832 			  function, line);
833 }
834 
835 const char *ext4_decode_error(struct super_block *sb, int errno,
836 			      char nbuf[16])
837 {
838 	char *errstr = NULL;
839 
840 	switch (errno) {
841 	case -EFSCORRUPTED:
842 		errstr = "Corrupt filesystem";
843 		break;
844 	case -EFSBADCRC:
845 		errstr = "Filesystem failed CRC";
846 		break;
847 	case -EIO:
848 		errstr = "IO failure";
849 		break;
850 	case -ENOMEM:
851 		errstr = "Out of memory";
852 		break;
853 	case -EROFS:
854 		if (!sb || (EXT4_SB(sb)->s_journal &&
855 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
856 			errstr = "Journal has aborted";
857 		else
858 			errstr = "Readonly filesystem";
859 		break;
860 	default:
861 		/* If the caller passed in an extra buffer for unknown
862 		 * errors, textualise them now.  Else we just return
863 		 * NULL. */
864 		if (nbuf) {
865 			/* Check for truncated error codes... */
866 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
867 				errstr = nbuf;
868 		}
869 		break;
870 	}
871 
872 	return errstr;
873 }
874 
875 /* __ext4_std_error decodes expected errors from journaling functions
876  * automatically and invokes the appropriate error response.  */
877 
878 void __ext4_std_error(struct super_block *sb, const char *function,
879 		      unsigned int line, int errno)
880 {
881 	char nbuf[16];
882 	const char *errstr;
883 
884 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
885 		return;
886 
887 	/* Special case: if the error is EROFS, and we're not already
888 	 * inside a transaction, then there's really no point in logging
889 	 * an error. */
890 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
891 		return;
892 
893 	if (ext4_error_ratelimit(sb)) {
894 		errstr = ext4_decode_error(sb, errno, nbuf);
895 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
896 		       sb->s_id, function, line, errstr);
897 	}
898 
899 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
900 }
901 
902 void __ext4_msg(struct super_block *sb,
903 		const char *prefix, const char *fmt, ...)
904 {
905 	struct va_format vaf;
906 	va_list args;
907 
908 	atomic_inc(&EXT4_SB(sb)->s_msg_count);
909 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
910 		return;
911 
912 	va_start(args, fmt);
913 	vaf.fmt = fmt;
914 	vaf.va = &args;
915 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
916 	va_end(args);
917 }
918 
919 static int ext4_warning_ratelimit(struct super_block *sb)
920 {
921 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
922 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
923 			    "EXT4-fs warning");
924 }
925 
926 void __ext4_warning(struct super_block *sb, const char *function,
927 		    unsigned int line, const char *fmt, ...)
928 {
929 	struct va_format vaf;
930 	va_list args;
931 
932 	if (!ext4_warning_ratelimit(sb))
933 		return;
934 
935 	va_start(args, fmt);
936 	vaf.fmt = fmt;
937 	vaf.va = &args;
938 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
939 	       sb->s_id, function, line, &vaf);
940 	va_end(args);
941 }
942 
943 void __ext4_warning_inode(const struct inode *inode, const char *function,
944 			  unsigned int line, const char *fmt, ...)
945 {
946 	struct va_format vaf;
947 	va_list args;
948 
949 	if (!ext4_warning_ratelimit(inode->i_sb))
950 		return;
951 
952 	va_start(args, fmt);
953 	vaf.fmt = fmt;
954 	vaf.va = &args;
955 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
956 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
957 	       function, line, inode->i_ino, current->comm, &vaf);
958 	va_end(args);
959 }
960 
961 void __ext4_grp_locked_error(const char *function, unsigned int line,
962 			     struct super_block *sb, ext4_group_t grp,
963 			     unsigned long ino, ext4_fsblk_t block,
964 			     const char *fmt, ...)
965 __releases(bitlock)
966 __acquires(bitlock)
967 {
968 	struct va_format vaf;
969 	va_list args;
970 
971 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
972 		return;
973 
974 	trace_ext4_error(sb, function, line);
975 	if (ext4_error_ratelimit(sb)) {
976 		va_start(args, fmt);
977 		vaf.fmt = fmt;
978 		vaf.va = &args;
979 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
980 		       sb->s_id, function, line, grp);
981 		if (ino)
982 			printk(KERN_CONT "inode %lu: ", ino);
983 		if (block)
984 			printk(KERN_CONT "block %llu:",
985 			       (unsigned long long) block);
986 		printk(KERN_CONT "%pV\n", &vaf);
987 		va_end(args);
988 	}
989 
990 	if (test_opt(sb, ERRORS_CONT)) {
991 		if (test_opt(sb, WARN_ON_ERROR))
992 			WARN_ON_ONCE(1);
993 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
994 		if (!bdev_read_only(sb->s_bdev)) {
995 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
996 					line);
997 			schedule_work(&EXT4_SB(sb)->s_error_work);
998 		}
999 		return;
1000 	}
1001 	ext4_unlock_group(sb, grp);
1002 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1003 	/*
1004 	 * We only get here in the ERRORS_RO case; relocking the group
1005 	 * may be dangerous, but nothing bad will happen since the
1006 	 * filesystem will have already been marked read/only and the
1007 	 * journal has been aborted.  We return 1 as a hint to callers
1008 	 * who might what to use the return value from
1009 	 * ext4_grp_locked_error() to distinguish between the
1010 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1011 	 * aggressively from the ext4 function in question, with a
1012 	 * more appropriate error code.
1013 	 */
1014 	ext4_lock_group(sb, grp);
1015 	return;
1016 }
1017 
1018 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1019 				     ext4_group_t group,
1020 				     unsigned int flags)
1021 {
1022 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1023 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1024 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1025 	int ret;
1026 
1027 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1028 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1029 					    &grp->bb_state);
1030 		if (!ret)
1031 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1032 					   grp->bb_free);
1033 	}
1034 
1035 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1036 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1037 					    &grp->bb_state);
1038 		if (!ret && gdp) {
1039 			int count;
1040 
1041 			count = ext4_free_inodes_count(sb, gdp);
1042 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1043 					   count);
1044 		}
1045 	}
1046 }
1047 
1048 void ext4_update_dynamic_rev(struct super_block *sb)
1049 {
1050 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1051 
1052 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1053 		return;
1054 
1055 	ext4_warning(sb,
1056 		     "updating to rev %d because of new feature flag, "
1057 		     "running e2fsck is recommended",
1058 		     EXT4_DYNAMIC_REV);
1059 
1060 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1061 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1062 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1063 	/* leave es->s_feature_*compat flags alone */
1064 	/* es->s_uuid will be set by e2fsck if empty */
1065 
1066 	/*
1067 	 * The rest of the superblock fields should be zero, and if not it
1068 	 * means they are likely already in use, so leave them alone.  We
1069 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1070 	 */
1071 }
1072 
1073 /*
1074  * Open the external journal device
1075  */
1076 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1077 {
1078 	struct block_device *bdev;
1079 
1080 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1081 	if (IS_ERR(bdev))
1082 		goto fail;
1083 	return bdev;
1084 
1085 fail:
1086 	ext4_msg(sb, KERN_ERR,
1087 		 "failed to open journal device unknown-block(%u,%u) %ld",
1088 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1089 	return NULL;
1090 }
1091 
1092 /*
1093  * Release the journal device
1094  */
1095 static void ext4_blkdev_put(struct block_device *bdev)
1096 {
1097 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1098 }
1099 
1100 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1101 {
1102 	struct block_device *bdev;
1103 	bdev = sbi->s_journal_bdev;
1104 	if (bdev) {
1105 		ext4_blkdev_put(bdev);
1106 		sbi->s_journal_bdev = NULL;
1107 	}
1108 }
1109 
1110 static inline struct inode *orphan_list_entry(struct list_head *l)
1111 {
1112 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1113 }
1114 
1115 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1116 {
1117 	struct list_head *l;
1118 
1119 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1120 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1121 
1122 	printk(KERN_ERR "sb_info orphan list:\n");
1123 	list_for_each(l, &sbi->s_orphan) {
1124 		struct inode *inode = orphan_list_entry(l);
1125 		printk(KERN_ERR "  "
1126 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1127 		       inode->i_sb->s_id, inode->i_ino, inode,
1128 		       inode->i_mode, inode->i_nlink,
1129 		       NEXT_ORPHAN(inode));
1130 	}
1131 }
1132 
1133 #ifdef CONFIG_QUOTA
1134 static int ext4_quota_off(struct super_block *sb, int type);
1135 
1136 static inline void ext4_quota_off_umount(struct super_block *sb)
1137 {
1138 	int type;
1139 
1140 	/* Use our quota_off function to clear inode flags etc. */
1141 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1142 		ext4_quota_off(sb, type);
1143 }
1144 
1145 /*
1146  * This is a helper function which is used in the mount/remount
1147  * codepaths (which holds s_umount) to fetch the quota file name.
1148  */
1149 static inline char *get_qf_name(struct super_block *sb,
1150 				struct ext4_sb_info *sbi,
1151 				int type)
1152 {
1153 	return rcu_dereference_protected(sbi->s_qf_names[type],
1154 					 lockdep_is_held(&sb->s_umount));
1155 }
1156 #else
1157 static inline void ext4_quota_off_umount(struct super_block *sb)
1158 {
1159 }
1160 #endif
1161 
1162 static void ext4_put_super(struct super_block *sb)
1163 {
1164 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1165 	struct ext4_super_block *es = sbi->s_es;
1166 	struct buffer_head **group_desc;
1167 	struct flex_groups **flex_groups;
1168 	int aborted = 0;
1169 	int i, err;
1170 
1171 	ext4_unregister_li_request(sb);
1172 	ext4_quota_off_umount(sb);
1173 
1174 	flush_work(&sbi->s_error_work);
1175 	destroy_workqueue(sbi->rsv_conversion_wq);
1176 
1177 	/*
1178 	 * Unregister sysfs before destroying jbd2 journal.
1179 	 * Since we could still access attr_journal_task attribute via sysfs
1180 	 * path which could have sbi->s_journal->j_task as NULL
1181 	 */
1182 	ext4_unregister_sysfs(sb);
1183 
1184 	if (sbi->s_journal) {
1185 		aborted = is_journal_aborted(sbi->s_journal);
1186 		err = jbd2_journal_destroy(sbi->s_journal);
1187 		sbi->s_journal = NULL;
1188 		if ((err < 0) && !aborted) {
1189 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1190 		}
1191 	}
1192 
1193 	ext4_es_unregister_shrinker(sbi);
1194 	del_timer_sync(&sbi->s_err_report);
1195 	ext4_release_system_zone(sb);
1196 	ext4_mb_release(sb);
1197 	ext4_ext_release(sb);
1198 
1199 	if (!sb_rdonly(sb) && !aborted) {
1200 		ext4_clear_feature_journal_needs_recovery(sb);
1201 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1202 	}
1203 	if (!sb_rdonly(sb))
1204 		ext4_commit_super(sb);
1205 
1206 	rcu_read_lock();
1207 	group_desc = rcu_dereference(sbi->s_group_desc);
1208 	for (i = 0; i < sbi->s_gdb_count; i++)
1209 		brelse(group_desc[i]);
1210 	kvfree(group_desc);
1211 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1212 	if (flex_groups) {
1213 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1214 			kvfree(flex_groups[i]);
1215 		kvfree(flex_groups);
1216 	}
1217 	rcu_read_unlock();
1218 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1219 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1220 	percpu_counter_destroy(&sbi->s_dirs_counter);
1221 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1222 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1223 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1224 #ifdef CONFIG_QUOTA
1225 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1226 		kfree(get_qf_name(sb, sbi, i));
1227 #endif
1228 
1229 	/* Debugging code just in case the in-memory inode orphan list
1230 	 * isn't empty.  The on-disk one can be non-empty if we've
1231 	 * detected an error and taken the fs readonly, but the
1232 	 * in-memory list had better be clean by this point. */
1233 	if (!list_empty(&sbi->s_orphan))
1234 		dump_orphan_list(sb, sbi);
1235 	ASSERT(list_empty(&sbi->s_orphan));
1236 
1237 	sync_blockdev(sb->s_bdev);
1238 	invalidate_bdev(sb->s_bdev);
1239 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1240 		/*
1241 		 * Invalidate the journal device's buffers.  We don't want them
1242 		 * floating about in memory - the physical journal device may
1243 		 * hotswapped, and it breaks the `ro-after' testing code.
1244 		 */
1245 		sync_blockdev(sbi->s_journal_bdev);
1246 		invalidate_bdev(sbi->s_journal_bdev);
1247 		ext4_blkdev_remove(sbi);
1248 	}
1249 
1250 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1251 	sbi->s_ea_inode_cache = NULL;
1252 
1253 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1254 	sbi->s_ea_block_cache = NULL;
1255 
1256 	ext4_stop_mmpd(sbi);
1257 
1258 	brelse(sbi->s_sbh);
1259 	sb->s_fs_info = NULL;
1260 	/*
1261 	 * Now that we are completely done shutting down the
1262 	 * superblock, we need to actually destroy the kobject.
1263 	 */
1264 	kobject_put(&sbi->s_kobj);
1265 	wait_for_completion(&sbi->s_kobj_unregister);
1266 	if (sbi->s_chksum_driver)
1267 		crypto_free_shash(sbi->s_chksum_driver);
1268 	kfree(sbi->s_blockgroup_lock);
1269 	fs_put_dax(sbi->s_daxdev);
1270 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1271 #ifdef CONFIG_UNICODE
1272 	utf8_unload(sb->s_encoding);
1273 #endif
1274 	kfree(sbi);
1275 }
1276 
1277 static struct kmem_cache *ext4_inode_cachep;
1278 
1279 /*
1280  * Called inside transaction, so use GFP_NOFS
1281  */
1282 static struct inode *ext4_alloc_inode(struct super_block *sb)
1283 {
1284 	struct ext4_inode_info *ei;
1285 
1286 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1287 	if (!ei)
1288 		return NULL;
1289 
1290 	inode_set_iversion(&ei->vfs_inode, 1);
1291 	spin_lock_init(&ei->i_raw_lock);
1292 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1293 	atomic_set(&ei->i_prealloc_active, 0);
1294 	spin_lock_init(&ei->i_prealloc_lock);
1295 	ext4_es_init_tree(&ei->i_es_tree);
1296 	rwlock_init(&ei->i_es_lock);
1297 	INIT_LIST_HEAD(&ei->i_es_list);
1298 	ei->i_es_all_nr = 0;
1299 	ei->i_es_shk_nr = 0;
1300 	ei->i_es_shrink_lblk = 0;
1301 	ei->i_reserved_data_blocks = 0;
1302 	spin_lock_init(&(ei->i_block_reservation_lock));
1303 	ext4_init_pending_tree(&ei->i_pending_tree);
1304 #ifdef CONFIG_QUOTA
1305 	ei->i_reserved_quota = 0;
1306 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1307 #endif
1308 	ei->jinode = NULL;
1309 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1310 	spin_lock_init(&ei->i_completed_io_lock);
1311 	ei->i_sync_tid = 0;
1312 	ei->i_datasync_tid = 0;
1313 	atomic_set(&ei->i_unwritten, 0);
1314 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1315 	ext4_fc_init_inode(&ei->vfs_inode);
1316 	mutex_init(&ei->i_fc_lock);
1317 	return &ei->vfs_inode;
1318 }
1319 
1320 static int ext4_drop_inode(struct inode *inode)
1321 {
1322 	int drop = generic_drop_inode(inode);
1323 
1324 	if (!drop)
1325 		drop = fscrypt_drop_inode(inode);
1326 
1327 	trace_ext4_drop_inode(inode, drop);
1328 	return drop;
1329 }
1330 
1331 static void ext4_free_in_core_inode(struct inode *inode)
1332 {
1333 	fscrypt_free_inode(inode);
1334 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1335 		pr_warn("%s: inode %ld still in fc list",
1336 			__func__, inode->i_ino);
1337 	}
1338 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1339 }
1340 
1341 static void ext4_destroy_inode(struct inode *inode)
1342 {
1343 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1344 		ext4_msg(inode->i_sb, KERN_ERR,
1345 			 "Inode %lu (%p): orphan list check failed!",
1346 			 inode->i_ino, EXT4_I(inode));
1347 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1348 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1349 				true);
1350 		dump_stack();
1351 	}
1352 }
1353 
1354 static void init_once(void *foo)
1355 {
1356 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1357 
1358 	INIT_LIST_HEAD(&ei->i_orphan);
1359 	init_rwsem(&ei->xattr_sem);
1360 	init_rwsem(&ei->i_data_sem);
1361 	inode_init_once(&ei->vfs_inode);
1362 	ext4_fc_init_inode(&ei->vfs_inode);
1363 }
1364 
1365 static int __init init_inodecache(void)
1366 {
1367 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1368 				sizeof(struct ext4_inode_info), 0,
1369 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1370 					SLAB_ACCOUNT),
1371 				offsetof(struct ext4_inode_info, i_data),
1372 				sizeof_field(struct ext4_inode_info, i_data),
1373 				init_once);
1374 	if (ext4_inode_cachep == NULL)
1375 		return -ENOMEM;
1376 	return 0;
1377 }
1378 
1379 static void destroy_inodecache(void)
1380 {
1381 	/*
1382 	 * Make sure all delayed rcu free inodes are flushed before we
1383 	 * destroy cache.
1384 	 */
1385 	rcu_barrier();
1386 	kmem_cache_destroy(ext4_inode_cachep);
1387 }
1388 
1389 void ext4_clear_inode(struct inode *inode)
1390 {
1391 	ext4_fc_del(inode);
1392 	invalidate_inode_buffers(inode);
1393 	clear_inode(inode);
1394 	ext4_discard_preallocations(inode, 0);
1395 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1396 	dquot_drop(inode);
1397 	if (EXT4_I(inode)->jinode) {
1398 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1399 					       EXT4_I(inode)->jinode);
1400 		jbd2_free_inode(EXT4_I(inode)->jinode);
1401 		EXT4_I(inode)->jinode = NULL;
1402 	}
1403 	fscrypt_put_encryption_info(inode);
1404 	fsverity_cleanup_inode(inode);
1405 }
1406 
1407 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1408 					u64 ino, u32 generation)
1409 {
1410 	struct inode *inode;
1411 
1412 	/*
1413 	 * Currently we don't know the generation for parent directory, so
1414 	 * a generation of 0 means "accept any"
1415 	 */
1416 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1417 	if (IS_ERR(inode))
1418 		return ERR_CAST(inode);
1419 	if (generation && inode->i_generation != generation) {
1420 		iput(inode);
1421 		return ERR_PTR(-ESTALE);
1422 	}
1423 
1424 	return inode;
1425 }
1426 
1427 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1428 					int fh_len, int fh_type)
1429 {
1430 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1431 				    ext4_nfs_get_inode);
1432 }
1433 
1434 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1435 					int fh_len, int fh_type)
1436 {
1437 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1438 				    ext4_nfs_get_inode);
1439 }
1440 
1441 static int ext4_nfs_commit_metadata(struct inode *inode)
1442 {
1443 	struct writeback_control wbc = {
1444 		.sync_mode = WB_SYNC_ALL
1445 	};
1446 
1447 	trace_ext4_nfs_commit_metadata(inode);
1448 	return ext4_write_inode(inode, &wbc);
1449 }
1450 
1451 #ifdef CONFIG_FS_ENCRYPTION
1452 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1453 {
1454 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1455 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1456 }
1457 
1458 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1459 							void *fs_data)
1460 {
1461 	handle_t *handle = fs_data;
1462 	int res, res2, credits, retries = 0;
1463 
1464 	/*
1465 	 * Encrypting the root directory is not allowed because e2fsck expects
1466 	 * lost+found to exist and be unencrypted, and encrypting the root
1467 	 * directory would imply encrypting the lost+found directory as well as
1468 	 * the filename "lost+found" itself.
1469 	 */
1470 	if (inode->i_ino == EXT4_ROOT_INO)
1471 		return -EPERM;
1472 
1473 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1474 		return -EINVAL;
1475 
1476 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1477 		return -EOPNOTSUPP;
1478 
1479 	res = ext4_convert_inline_data(inode);
1480 	if (res)
1481 		return res;
1482 
1483 	/*
1484 	 * If a journal handle was specified, then the encryption context is
1485 	 * being set on a new inode via inheritance and is part of a larger
1486 	 * transaction to create the inode.  Otherwise the encryption context is
1487 	 * being set on an existing inode in its own transaction.  Only in the
1488 	 * latter case should the "retry on ENOSPC" logic be used.
1489 	 */
1490 
1491 	if (handle) {
1492 		res = ext4_xattr_set_handle(handle, inode,
1493 					    EXT4_XATTR_INDEX_ENCRYPTION,
1494 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1495 					    ctx, len, 0);
1496 		if (!res) {
1497 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1498 			ext4_clear_inode_state(inode,
1499 					EXT4_STATE_MAY_INLINE_DATA);
1500 			/*
1501 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1502 			 * S_DAX may be disabled
1503 			 */
1504 			ext4_set_inode_flags(inode, false);
1505 		}
1506 		return res;
1507 	}
1508 
1509 	res = dquot_initialize(inode);
1510 	if (res)
1511 		return res;
1512 retry:
1513 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1514 				     &credits);
1515 	if (res)
1516 		return res;
1517 
1518 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1519 	if (IS_ERR(handle))
1520 		return PTR_ERR(handle);
1521 
1522 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1523 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1524 				    ctx, len, 0);
1525 	if (!res) {
1526 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1527 		/*
1528 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1529 		 * S_DAX may be disabled
1530 		 */
1531 		ext4_set_inode_flags(inode, false);
1532 		res = ext4_mark_inode_dirty(handle, inode);
1533 		if (res)
1534 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1535 	}
1536 	res2 = ext4_journal_stop(handle);
1537 
1538 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1539 		goto retry;
1540 	if (!res)
1541 		res = res2;
1542 	return res;
1543 }
1544 
1545 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1546 {
1547 	return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1548 }
1549 
1550 static bool ext4_has_stable_inodes(struct super_block *sb)
1551 {
1552 	return ext4_has_feature_stable_inodes(sb);
1553 }
1554 
1555 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1556 				       int *ino_bits_ret, int *lblk_bits_ret)
1557 {
1558 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1559 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1560 }
1561 
1562 static const struct fscrypt_operations ext4_cryptops = {
1563 	.key_prefix		= "ext4:",
1564 	.get_context		= ext4_get_context,
1565 	.set_context		= ext4_set_context,
1566 	.get_dummy_policy	= ext4_get_dummy_policy,
1567 	.empty_dir		= ext4_empty_dir,
1568 	.max_namelen		= EXT4_NAME_LEN,
1569 	.has_stable_inodes	= ext4_has_stable_inodes,
1570 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1571 };
1572 #endif
1573 
1574 #ifdef CONFIG_QUOTA
1575 static const char * const quotatypes[] = INITQFNAMES;
1576 #define QTYPE2NAME(t) (quotatypes[t])
1577 
1578 static int ext4_write_dquot(struct dquot *dquot);
1579 static int ext4_acquire_dquot(struct dquot *dquot);
1580 static int ext4_release_dquot(struct dquot *dquot);
1581 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1582 static int ext4_write_info(struct super_block *sb, int type);
1583 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1584 			 const struct path *path);
1585 static int ext4_quota_on_mount(struct super_block *sb, int type);
1586 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1587 			       size_t len, loff_t off);
1588 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1589 				const char *data, size_t len, loff_t off);
1590 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1591 			     unsigned int flags);
1592 static int ext4_enable_quotas(struct super_block *sb);
1593 
1594 static struct dquot **ext4_get_dquots(struct inode *inode)
1595 {
1596 	return EXT4_I(inode)->i_dquot;
1597 }
1598 
1599 static const struct dquot_operations ext4_quota_operations = {
1600 	.get_reserved_space	= ext4_get_reserved_space,
1601 	.write_dquot		= ext4_write_dquot,
1602 	.acquire_dquot		= ext4_acquire_dquot,
1603 	.release_dquot		= ext4_release_dquot,
1604 	.mark_dirty		= ext4_mark_dquot_dirty,
1605 	.write_info		= ext4_write_info,
1606 	.alloc_dquot		= dquot_alloc,
1607 	.destroy_dquot		= dquot_destroy,
1608 	.get_projid		= ext4_get_projid,
1609 	.get_inode_usage	= ext4_get_inode_usage,
1610 	.get_next_id		= dquot_get_next_id,
1611 };
1612 
1613 static const struct quotactl_ops ext4_qctl_operations = {
1614 	.quota_on	= ext4_quota_on,
1615 	.quota_off	= ext4_quota_off,
1616 	.quota_sync	= dquot_quota_sync,
1617 	.get_state	= dquot_get_state,
1618 	.set_info	= dquot_set_dqinfo,
1619 	.get_dqblk	= dquot_get_dqblk,
1620 	.set_dqblk	= dquot_set_dqblk,
1621 	.get_nextdqblk	= dquot_get_next_dqblk,
1622 };
1623 #endif
1624 
1625 static const struct super_operations ext4_sops = {
1626 	.alloc_inode	= ext4_alloc_inode,
1627 	.free_inode	= ext4_free_in_core_inode,
1628 	.destroy_inode	= ext4_destroy_inode,
1629 	.write_inode	= ext4_write_inode,
1630 	.dirty_inode	= ext4_dirty_inode,
1631 	.drop_inode	= ext4_drop_inode,
1632 	.evict_inode	= ext4_evict_inode,
1633 	.put_super	= ext4_put_super,
1634 	.sync_fs	= ext4_sync_fs,
1635 	.freeze_fs	= ext4_freeze,
1636 	.unfreeze_fs	= ext4_unfreeze,
1637 	.statfs		= ext4_statfs,
1638 	.remount_fs	= ext4_remount,
1639 	.show_options	= ext4_show_options,
1640 #ifdef CONFIG_QUOTA
1641 	.quota_read	= ext4_quota_read,
1642 	.quota_write	= ext4_quota_write,
1643 	.get_dquots	= ext4_get_dquots,
1644 #endif
1645 };
1646 
1647 static const struct export_operations ext4_export_ops = {
1648 	.fh_to_dentry = ext4_fh_to_dentry,
1649 	.fh_to_parent = ext4_fh_to_parent,
1650 	.get_parent = ext4_get_parent,
1651 	.commit_metadata = ext4_nfs_commit_metadata,
1652 };
1653 
1654 enum {
1655 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1656 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1657 	Opt_nouid32, Opt_debug, Opt_removed,
1658 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1659 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1660 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1661 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1662 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1663 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1664 	Opt_inlinecrypt,
1665 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1666 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1667 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1668 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1669 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1670 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1671 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1672 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1673 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1674 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1675 	Opt_dioread_nolock, Opt_dioread_lock,
1676 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1677 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1678 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1679 #ifdef CONFIG_EXT4_DEBUG
1680 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1681 #endif
1682 };
1683 
1684 static const match_table_t tokens = {
1685 	{Opt_bsd_df, "bsddf"},
1686 	{Opt_minix_df, "minixdf"},
1687 	{Opt_grpid, "grpid"},
1688 	{Opt_grpid, "bsdgroups"},
1689 	{Opt_nogrpid, "nogrpid"},
1690 	{Opt_nogrpid, "sysvgroups"},
1691 	{Opt_resgid, "resgid=%u"},
1692 	{Opt_resuid, "resuid=%u"},
1693 	{Opt_sb, "sb=%u"},
1694 	{Opt_err_cont, "errors=continue"},
1695 	{Opt_err_panic, "errors=panic"},
1696 	{Opt_err_ro, "errors=remount-ro"},
1697 	{Opt_nouid32, "nouid32"},
1698 	{Opt_debug, "debug"},
1699 	{Opt_removed, "oldalloc"},
1700 	{Opt_removed, "orlov"},
1701 	{Opt_user_xattr, "user_xattr"},
1702 	{Opt_nouser_xattr, "nouser_xattr"},
1703 	{Opt_acl, "acl"},
1704 	{Opt_noacl, "noacl"},
1705 	{Opt_noload, "norecovery"},
1706 	{Opt_noload, "noload"},
1707 	{Opt_removed, "nobh"},
1708 	{Opt_removed, "bh"},
1709 	{Opt_commit, "commit=%u"},
1710 	{Opt_min_batch_time, "min_batch_time=%u"},
1711 	{Opt_max_batch_time, "max_batch_time=%u"},
1712 	{Opt_journal_dev, "journal_dev=%u"},
1713 	{Opt_journal_path, "journal_path=%s"},
1714 	{Opt_journal_checksum, "journal_checksum"},
1715 	{Opt_nojournal_checksum, "nojournal_checksum"},
1716 	{Opt_journal_async_commit, "journal_async_commit"},
1717 	{Opt_abort, "abort"},
1718 	{Opt_data_journal, "data=journal"},
1719 	{Opt_data_ordered, "data=ordered"},
1720 	{Opt_data_writeback, "data=writeback"},
1721 	{Opt_data_err_abort, "data_err=abort"},
1722 	{Opt_data_err_ignore, "data_err=ignore"},
1723 	{Opt_offusrjquota, "usrjquota="},
1724 	{Opt_usrjquota, "usrjquota=%s"},
1725 	{Opt_offgrpjquota, "grpjquota="},
1726 	{Opt_grpjquota, "grpjquota=%s"},
1727 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1728 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1729 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1730 	{Opt_grpquota, "grpquota"},
1731 	{Opt_noquota, "noquota"},
1732 	{Opt_quota, "quota"},
1733 	{Opt_usrquota, "usrquota"},
1734 	{Opt_prjquota, "prjquota"},
1735 	{Opt_barrier, "barrier=%u"},
1736 	{Opt_barrier, "barrier"},
1737 	{Opt_nobarrier, "nobarrier"},
1738 	{Opt_i_version, "i_version"},
1739 	{Opt_dax, "dax"},
1740 	{Opt_dax_always, "dax=always"},
1741 	{Opt_dax_inode, "dax=inode"},
1742 	{Opt_dax_never, "dax=never"},
1743 	{Opt_stripe, "stripe=%u"},
1744 	{Opt_delalloc, "delalloc"},
1745 	{Opt_warn_on_error, "warn_on_error"},
1746 	{Opt_nowarn_on_error, "nowarn_on_error"},
1747 	{Opt_lazytime, "lazytime"},
1748 	{Opt_nolazytime, "nolazytime"},
1749 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1750 	{Opt_nodelalloc, "nodelalloc"},
1751 	{Opt_removed, "mblk_io_submit"},
1752 	{Opt_removed, "nomblk_io_submit"},
1753 	{Opt_block_validity, "block_validity"},
1754 	{Opt_noblock_validity, "noblock_validity"},
1755 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1756 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1757 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1758 	{Opt_auto_da_alloc, "auto_da_alloc"},
1759 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1760 	{Opt_dioread_nolock, "dioread_nolock"},
1761 	{Opt_dioread_lock, "nodioread_nolock"},
1762 	{Opt_dioread_lock, "dioread_lock"},
1763 	{Opt_discard, "discard"},
1764 	{Opt_nodiscard, "nodiscard"},
1765 	{Opt_init_itable, "init_itable=%u"},
1766 	{Opt_init_itable, "init_itable"},
1767 	{Opt_noinit_itable, "noinit_itable"},
1768 #ifdef CONFIG_EXT4_DEBUG
1769 	{Opt_fc_debug_force, "fc_debug_force"},
1770 	{Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
1771 #endif
1772 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1773 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1774 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1775 	{Opt_inlinecrypt, "inlinecrypt"},
1776 	{Opt_nombcache, "nombcache"},
1777 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1778 	{Opt_removed, "prefetch_block_bitmaps"},
1779 	{Opt_no_prefetch_block_bitmaps, "no_prefetch_block_bitmaps"},
1780 	{Opt_mb_optimize_scan, "mb_optimize_scan=%d"},
1781 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1782 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1783 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1784 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1785 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1786 	{Opt_err, NULL},
1787 };
1788 
1789 static ext4_fsblk_t get_sb_block(void **data)
1790 {
1791 	ext4_fsblk_t	sb_block;
1792 	char		*options = (char *) *data;
1793 
1794 	if (!options || strncmp(options, "sb=", 3) != 0)
1795 		return 1;	/* Default location */
1796 
1797 	options += 3;
1798 	/* TODO: use simple_strtoll with >32bit ext4 */
1799 	sb_block = simple_strtoul(options, &options, 0);
1800 	if (*options && *options != ',') {
1801 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1802 		       (char *) *data);
1803 		return 1;
1804 	}
1805 	if (*options == ',')
1806 		options++;
1807 	*data = (void *) options;
1808 
1809 	return sb_block;
1810 }
1811 
1812 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1813 #define DEFAULT_MB_OPTIMIZE_SCAN	(-1)
1814 
1815 static const char deprecated_msg[] =
1816 	"Mount option \"%s\" will be removed by %s\n"
1817 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1818 
1819 #ifdef CONFIG_QUOTA
1820 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1821 {
1822 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1823 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1824 	int ret = -1;
1825 
1826 	if (sb_any_quota_loaded(sb) && !old_qname) {
1827 		ext4_msg(sb, KERN_ERR,
1828 			"Cannot change journaled "
1829 			"quota options when quota turned on");
1830 		return -1;
1831 	}
1832 	if (ext4_has_feature_quota(sb)) {
1833 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1834 			 "ignored when QUOTA feature is enabled");
1835 		return 1;
1836 	}
1837 	qname = match_strdup(args);
1838 	if (!qname) {
1839 		ext4_msg(sb, KERN_ERR,
1840 			"Not enough memory for storing quotafile name");
1841 		return -1;
1842 	}
1843 	if (old_qname) {
1844 		if (strcmp(old_qname, qname) == 0)
1845 			ret = 1;
1846 		else
1847 			ext4_msg(sb, KERN_ERR,
1848 				 "%s quota file already specified",
1849 				 QTYPE2NAME(qtype));
1850 		goto errout;
1851 	}
1852 	if (strchr(qname, '/')) {
1853 		ext4_msg(sb, KERN_ERR,
1854 			"quotafile must be on filesystem root");
1855 		goto errout;
1856 	}
1857 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1858 	set_opt(sb, QUOTA);
1859 	return 1;
1860 errout:
1861 	kfree(qname);
1862 	return ret;
1863 }
1864 
1865 static int clear_qf_name(struct super_block *sb, int qtype)
1866 {
1867 
1868 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1869 	char *old_qname = get_qf_name(sb, sbi, qtype);
1870 
1871 	if (sb_any_quota_loaded(sb) && old_qname) {
1872 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1873 			" when quota turned on");
1874 		return -1;
1875 	}
1876 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1877 	synchronize_rcu();
1878 	kfree(old_qname);
1879 	return 1;
1880 }
1881 #endif
1882 
1883 #define MOPT_SET	0x0001
1884 #define MOPT_CLEAR	0x0002
1885 #define MOPT_NOSUPPORT	0x0004
1886 #define MOPT_EXPLICIT	0x0008
1887 #define MOPT_CLEAR_ERR	0x0010
1888 #define MOPT_GTE0	0x0020
1889 #ifdef CONFIG_QUOTA
1890 #define MOPT_Q		0
1891 #define MOPT_QFMT	0x0040
1892 #else
1893 #define MOPT_Q		MOPT_NOSUPPORT
1894 #define MOPT_QFMT	MOPT_NOSUPPORT
1895 #endif
1896 #define MOPT_DATAJ	0x0080
1897 #define MOPT_NO_EXT2	0x0100
1898 #define MOPT_NO_EXT3	0x0200
1899 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1900 #define MOPT_STRING	0x0400
1901 #define MOPT_SKIP	0x0800
1902 #define	MOPT_2		0x1000
1903 
1904 static const struct mount_opts {
1905 	int	token;
1906 	int	mount_opt;
1907 	int	flags;
1908 } ext4_mount_opts[] = {
1909 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1910 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1911 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1912 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1913 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1914 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1915 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1916 	 MOPT_EXT4_ONLY | MOPT_SET},
1917 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1918 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1919 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1920 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1921 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1922 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1923 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1924 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1925 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1926 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1927 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1928 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1929 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1930 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1931 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1932 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1933 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1934 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1935 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1936 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1937 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1938 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1939 	 MOPT_NO_EXT2},
1940 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1941 	 MOPT_NO_EXT2},
1942 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1943 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1944 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1945 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1946 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1947 	{Opt_commit, 0, MOPT_GTE0},
1948 	{Opt_max_batch_time, 0, MOPT_GTE0},
1949 	{Opt_min_batch_time, 0, MOPT_GTE0},
1950 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1951 	{Opt_init_itable, 0, MOPT_GTE0},
1952 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1953 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1954 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1955 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1956 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1957 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1958 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1959 	{Opt_stripe, 0, MOPT_GTE0},
1960 	{Opt_resuid, 0, MOPT_GTE0},
1961 	{Opt_resgid, 0, MOPT_GTE0},
1962 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1963 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1964 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1965 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1966 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1967 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1968 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1969 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1970 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1971 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1972 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1973 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1974 #else
1975 	{Opt_acl, 0, MOPT_NOSUPPORT},
1976 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1977 #endif
1978 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1979 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1980 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1981 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1982 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1983 							MOPT_SET | MOPT_Q},
1984 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1985 							MOPT_SET | MOPT_Q},
1986 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1987 							MOPT_SET | MOPT_Q},
1988 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1989 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1990 							MOPT_CLEAR | MOPT_Q},
1991 	{Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
1992 	{Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
1993 	{Opt_offusrjquota, 0, MOPT_Q},
1994 	{Opt_offgrpjquota, 0, MOPT_Q},
1995 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1996 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1997 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1998 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1999 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
2000 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
2001 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
2002 	 MOPT_SET},
2003 	{Opt_mb_optimize_scan, EXT4_MOUNT2_MB_OPTIMIZE_SCAN, MOPT_GTE0},
2004 #ifdef CONFIG_EXT4_DEBUG
2005 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2006 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
2007 	{Opt_fc_debug_max_replay, 0, MOPT_GTE0},
2008 #endif
2009 	{Opt_err, 0, 0}
2010 };
2011 
2012 #ifdef CONFIG_UNICODE
2013 static const struct ext4_sb_encodings {
2014 	__u16 magic;
2015 	char *name;
2016 	char *version;
2017 } ext4_sb_encoding_map[] = {
2018 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
2019 };
2020 
2021 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
2022 				 const struct ext4_sb_encodings **encoding,
2023 				 __u16 *flags)
2024 {
2025 	__u16 magic = le16_to_cpu(es->s_encoding);
2026 	int i;
2027 
2028 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
2029 		if (magic == ext4_sb_encoding_map[i].magic)
2030 			break;
2031 
2032 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
2033 		return -EINVAL;
2034 
2035 	*encoding = &ext4_sb_encoding_map[i];
2036 	*flags = le16_to_cpu(es->s_encoding_flags);
2037 
2038 	return 0;
2039 }
2040 #endif
2041 
2042 static int ext4_set_test_dummy_encryption(struct super_block *sb,
2043 					  const char *opt,
2044 					  const substring_t *arg,
2045 					  bool is_remount)
2046 {
2047 #ifdef CONFIG_FS_ENCRYPTION
2048 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2049 	int err;
2050 
2051 	/*
2052 	 * This mount option is just for testing, and it's not worthwhile to
2053 	 * implement the extra complexity (e.g. RCU protection) that would be
2054 	 * needed to allow it to be set or changed during remount.  We do allow
2055 	 * it to be specified during remount, but only if there is no change.
2056 	 */
2057 	if (is_remount && !sbi->s_dummy_enc_policy.policy) {
2058 		ext4_msg(sb, KERN_WARNING,
2059 			 "Can't set test_dummy_encryption on remount");
2060 		return -1;
2061 	}
2062 	err = fscrypt_set_test_dummy_encryption(sb, arg->from,
2063 						&sbi->s_dummy_enc_policy);
2064 	if (err) {
2065 		if (err == -EEXIST)
2066 			ext4_msg(sb, KERN_WARNING,
2067 				 "Can't change test_dummy_encryption on remount");
2068 		else if (err == -EINVAL)
2069 			ext4_msg(sb, KERN_WARNING,
2070 				 "Value of option \"%s\" is unrecognized", opt);
2071 		else
2072 			ext4_msg(sb, KERN_WARNING,
2073 				 "Error processing option \"%s\" [%d]",
2074 				 opt, err);
2075 		return -1;
2076 	}
2077 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2078 #else
2079 	ext4_msg(sb, KERN_WARNING,
2080 		 "Test dummy encryption mount option ignored");
2081 #endif
2082 	return 1;
2083 }
2084 
2085 struct ext4_parsed_options {
2086 	unsigned long journal_devnum;
2087 	unsigned int journal_ioprio;
2088 	int mb_optimize_scan;
2089 };
2090 
2091 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
2092 			    substring_t *args, struct ext4_parsed_options *parsed_opts,
2093 			    int is_remount)
2094 {
2095 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2096 	const struct mount_opts *m;
2097 	kuid_t uid;
2098 	kgid_t gid;
2099 	int arg = 0;
2100 
2101 #ifdef CONFIG_QUOTA
2102 	if (token == Opt_usrjquota)
2103 		return set_qf_name(sb, USRQUOTA, &args[0]);
2104 	else if (token == Opt_grpjquota)
2105 		return set_qf_name(sb, GRPQUOTA, &args[0]);
2106 	else if (token == Opt_offusrjquota)
2107 		return clear_qf_name(sb, USRQUOTA);
2108 	else if (token == Opt_offgrpjquota)
2109 		return clear_qf_name(sb, GRPQUOTA);
2110 #endif
2111 	switch (token) {
2112 	case Opt_noacl:
2113 	case Opt_nouser_xattr:
2114 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
2115 		break;
2116 	case Opt_sb:
2117 		return 1;	/* handled by get_sb_block() */
2118 	case Opt_removed:
2119 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
2120 		return 1;
2121 	case Opt_abort:
2122 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
2123 		return 1;
2124 	case Opt_i_version:
2125 		sb->s_flags |= SB_I_VERSION;
2126 		return 1;
2127 	case Opt_lazytime:
2128 		sb->s_flags |= SB_LAZYTIME;
2129 		return 1;
2130 	case Opt_nolazytime:
2131 		sb->s_flags &= ~SB_LAZYTIME;
2132 		return 1;
2133 	case Opt_inlinecrypt:
2134 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2135 		sb->s_flags |= SB_INLINECRYPT;
2136 #else
2137 		ext4_msg(sb, KERN_ERR, "inline encryption not supported");
2138 #endif
2139 		return 1;
2140 	}
2141 
2142 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2143 		if (token == m->token)
2144 			break;
2145 
2146 	if (m->token == Opt_err) {
2147 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
2148 			 "or missing value", opt);
2149 		return -1;
2150 	}
2151 
2152 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2153 		ext4_msg(sb, KERN_ERR,
2154 			 "Mount option \"%s\" incompatible with ext2", opt);
2155 		return -1;
2156 	}
2157 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2158 		ext4_msg(sb, KERN_ERR,
2159 			 "Mount option \"%s\" incompatible with ext3", opt);
2160 		return -1;
2161 	}
2162 
2163 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
2164 		return -1;
2165 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
2166 		return -1;
2167 	if (m->flags & MOPT_EXPLICIT) {
2168 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2169 			set_opt2(sb, EXPLICIT_DELALLOC);
2170 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2171 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
2172 		} else
2173 			return -1;
2174 	}
2175 	if (m->flags & MOPT_CLEAR_ERR)
2176 		clear_opt(sb, ERRORS_MASK);
2177 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
2178 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
2179 			 "options when quota turned on");
2180 		return -1;
2181 	}
2182 
2183 	if (m->flags & MOPT_NOSUPPORT) {
2184 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
2185 	} else if (token == Opt_commit) {
2186 		if (arg == 0)
2187 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
2188 		else if (arg > INT_MAX / HZ) {
2189 			ext4_msg(sb, KERN_ERR,
2190 				 "Invalid commit interval %d, "
2191 				 "must be smaller than %d",
2192 				 arg, INT_MAX / HZ);
2193 			return -1;
2194 		}
2195 		sbi->s_commit_interval = HZ * arg;
2196 	} else if (token == Opt_debug_want_extra_isize) {
2197 		if ((arg & 1) ||
2198 		    (arg < 4) ||
2199 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2200 			ext4_msg(sb, KERN_ERR,
2201 				 "Invalid want_extra_isize %d", arg);
2202 			return -1;
2203 		}
2204 		sbi->s_want_extra_isize = arg;
2205 	} else if (token == Opt_max_batch_time) {
2206 		sbi->s_max_batch_time = arg;
2207 	} else if (token == Opt_min_batch_time) {
2208 		sbi->s_min_batch_time = arg;
2209 	} else if (token == Opt_inode_readahead_blks) {
2210 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2211 			ext4_msg(sb, KERN_ERR,
2212 				 "EXT4-fs: inode_readahead_blks must be "
2213 				 "0 or a power of 2 smaller than 2^31");
2214 			return -1;
2215 		}
2216 		sbi->s_inode_readahead_blks = arg;
2217 	} else if (token == Opt_init_itable) {
2218 		set_opt(sb, INIT_INODE_TABLE);
2219 		if (!args->from)
2220 			arg = EXT4_DEF_LI_WAIT_MULT;
2221 		sbi->s_li_wait_mult = arg;
2222 	} else if (token == Opt_max_dir_size_kb) {
2223 		sbi->s_max_dir_size_kb = arg;
2224 #ifdef CONFIG_EXT4_DEBUG
2225 	} else if (token == Opt_fc_debug_max_replay) {
2226 		sbi->s_fc_debug_max_replay = arg;
2227 #endif
2228 	} else if (token == Opt_stripe) {
2229 		sbi->s_stripe = arg;
2230 	} else if (token == Opt_resuid) {
2231 		uid = make_kuid(current_user_ns(), arg);
2232 		if (!uid_valid(uid)) {
2233 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2234 			return -1;
2235 		}
2236 		sbi->s_resuid = uid;
2237 	} else if (token == Opt_resgid) {
2238 		gid = make_kgid(current_user_ns(), arg);
2239 		if (!gid_valid(gid)) {
2240 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2241 			return -1;
2242 		}
2243 		sbi->s_resgid = gid;
2244 	} else if (token == Opt_journal_dev) {
2245 		if (is_remount) {
2246 			ext4_msg(sb, KERN_ERR,
2247 				 "Cannot specify journal on remount");
2248 			return -1;
2249 		}
2250 		parsed_opts->journal_devnum = arg;
2251 	} else if (token == Opt_journal_path) {
2252 		char *journal_path;
2253 		struct inode *journal_inode;
2254 		struct path path;
2255 		int error;
2256 
2257 		if (is_remount) {
2258 			ext4_msg(sb, KERN_ERR,
2259 				 "Cannot specify journal on remount");
2260 			return -1;
2261 		}
2262 		journal_path = match_strdup(&args[0]);
2263 		if (!journal_path) {
2264 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2265 				"journal device string");
2266 			return -1;
2267 		}
2268 
2269 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2270 		if (error) {
2271 			ext4_msg(sb, KERN_ERR, "error: could not find "
2272 				"journal device path: error %d", error);
2273 			kfree(journal_path);
2274 			return -1;
2275 		}
2276 
2277 		journal_inode = d_inode(path.dentry);
2278 		if (!S_ISBLK(journal_inode->i_mode)) {
2279 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2280 				"is not a block device", journal_path);
2281 			path_put(&path);
2282 			kfree(journal_path);
2283 			return -1;
2284 		}
2285 
2286 		parsed_opts->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2287 		path_put(&path);
2288 		kfree(journal_path);
2289 	} else if (token == Opt_journal_ioprio) {
2290 		if (arg > 7) {
2291 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2292 				 " (must be 0-7)");
2293 			return -1;
2294 		}
2295 		parsed_opts->journal_ioprio =
2296 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2297 	} else if (token == Opt_test_dummy_encryption) {
2298 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2299 						      is_remount);
2300 	} else if (m->flags & MOPT_DATAJ) {
2301 		if (is_remount) {
2302 			if (!sbi->s_journal)
2303 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2304 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2305 				ext4_msg(sb, KERN_ERR,
2306 					 "Cannot change data mode on remount");
2307 				return -1;
2308 			}
2309 		} else {
2310 			clear_opt(sb, DATA_FLAGS);
2311 			sbi->s_mount_opt |= m->mount_opt;
2312 		}
2313 #ifdef CONFIG_QUOTA
2314 	} else if (m->flags & MOPT_QFMT) {
2315 		if (sb_any_quota_loaded(sb) &&
2316 		    sbi->s_jquota_fmt != m->mount_opt) {
2317 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2318 				 "quota options when quota turned on");
2319 			return -1;
2320 		}
2321 		if (ext4_has_feature_quota(sb)) {
2322 			ext4_msg(sb, KERN_INFO,
2323 				 "Quota format mount options ignored "
2324 				 "when QUOTA feature is enabled");
2325 			return 1;
2326 		}
2327 		sbi->s_jquota_fmt = m->mount_opt;
2328 #endif
2329 	} else if (token == Opt_dax || token == Opt_dax_always ||
2330 		   token == Opt_dax_inode || token == Opt_dax_never) {
2331 #ifdef CONFIG_FS_DAX
2332 		switch (token) {
2333 		case Opt_dax:
2334 		case Opt_dax_always:
2335 			if (is_remount &&
2336 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2337 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2338 			fail_dax_change_remount:
2339 				ext4_msg(sb, KERN_ERR, "can't change "
2340 					 "dax mount option while remounting");
2341 				return -1;
2342 			}
2343 			if (is_remount &&
2344 			    (test_opt(sb, DATA_FLAGS) ==
2345 			     EXT4_MOUNT_JOURNAL_DATA)) {
2346 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2347 					     "both data=journal and dax");
2348 				    return -1;
2349 			}
2350 			ext4_msg(sb, KERN_WARNING,
2351 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2352 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2353 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2354 			break;
2355 		case Opt_dax_never:
2356 			if (is_remount &&
2357 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2358 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2359 				goto fail_dax_change_remount;
2360 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2361 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2362 			break;
2363 		case Opt_dax_inode:
2364 			if (is_remount &&
2365 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2366 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2367 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2368 				goto fail_dax_change_remount;
2369 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2370 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2371 			/* Strictly for printing options */
2372 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2373 			break;
2374 		}
2375 #else
2376 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2377 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2378 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2379 		return -1;
2380 #endif
2381 	} else if (token == Opt_data_err_abort) {
2382 		sbi->s_mount_opt |= m->mount_opt;
2383 	} else if (token == Opt_data_err_ignore) {
2384 		sbi->s_mount_opt &= ~m->mount_opt;
2385 	} else if (token == Opt_mb_optimize_scan) {
2386 		if (arg != 0 && arg != 1) {
2387 			ext4_msg(sb, KERN_WARNING,
2388 				 "mb_optimize_scan should be set to 0 or 1.");
2389 			return -1;
2390 		}
2391 		parsed_opts->mb_optimize_scan = arg;
2392 	} else {
2393 		if (!args->from)
2394 			arg = 1;
2395 		if (m->flags & MOPT_CLEAR)
2396 			arg = !arg;
2397 		else if (unlikely(!(m->flags & MOPT_SET))) {
2398 			ext4_msg(sb, KERN_WARNING,
2399 				 "buggy handling of option %s", opt);
2400 			WARN_ON(1);
2401 			return -1;
2402 		}
2403 		if (m->flags & MOPT_2) {
2404 			if (arg != 0)
2405 				sbi->s_mount_opt2 |= m->mount_opt;
2406 			else
2407 				sbi->s_mount_opt2 &= ~m->mount_opt;
2408 		} else {
2409 			if (arg != 0)
2410 				sbi->s_mount_opt |= m->mount_opt;
2411 			else
2412 				sbi->s_mount_opt &= ~m->mount_opt;
2413 		}
2414 	}
2415 	return 1;
2416 }
2417 
2418 static int parse_options(char *options, struct super_block *sb,
2419 			 struct ext4_parsed_options *ret_opts,
2420 			 int is_remount)
2421 {
2422 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2423 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2424 	substring_t args[MAX_OPT_ARGS];
2425 	int token;
2426 
2427 	if (!options)
2428 		return 1;
2429 
2430 	while ((p = strsep(&options, ",")) != NULL) {
2431 		if (!*p)
2432 			continue;
2433 		/*
2434 		 * Initialize args struct so we know whether arg was
2435 		 * found; some options take optional arguments.
2436 		 */
2437 		args[0].to = args[0].from = NULL;
2438 		token = match_token(p, tokens, args);
2439 		if (handle_mount_opt(sb, p, token, args, ret_opts,
2440 				     is_remount) < 0)
2441 			return 0;
2442 	}
2443 #ifdef CONFIG_QUOTA
2444 	/*
2445 	 * We do the test below only for project quotas. 'usrquota' and
2446 	 * 'grpquota' mount options are allowed even without quota feature
2447 	 * to support legacy quotas in quota files.
2448 	 */
2449 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2450 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2451 			 "Cannot enable project quota enforcement.");
2452 		return 0;
2453 	}
2454 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2455 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2456 	if (usr_qf_name || grp_qf_name) {
2457 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2458 			clear_opt(sb, USRQUOTA);
2459 
2460 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2461 			clear_opt(sb, GRPQUOTA);
2462 
2463 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2464 			ext4_msg(sb, KERN_ERR, "old and new quota "
2465 					"format mixing");
2466 			return 0;
2467 		}
2468 
2469 		if (!sbi->s_jquota_fmt) {
2470 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2471 					"not specified");
2472 			return 0;
2473 		}
2474 	}
2475 #endif
2476 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2477 		int blocksize =
2478 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2479 		if (blocksize < PAGE_SIZE)
2480 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2481 				 "experimental mount option 'dioread_nolock' "
2482 				 "for blocksize < PAGE_SIZE");
2483 	}
2484 	return 1;
2485 }
2486 
2487 static inline void ext4_show_quota_options(struct seq_file *seq,
2488 					   struct super_block *sb)
2489 {
2490 #if defined(CONFIG_QUOTA)
2491 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2492 	char *usr_qf_name, *grp_qf_name;
2493 
2494 	if (sbi->s_jquota_fmt) {
2495 		char *fmtname = "";
2496 
2497 		switch (sbi->s_jquota_fmt) {
2498 		case QFMT_VFS_OLD:
2499 			fmtname = "vfsold";
2500 			break;
2501 		case QFMT_VFS_V0:
2502 			fmtname = "vfsv0";
2503 			break;
2504 		case QFMT_VFS_V1:
2505 			fmtname = "vfsv1";
2506 			break;
2507 		}
2508 		seq_printf(seq, ",jqfmt=%s", fmtname);
2509 	}
2510 
2511 	rcu_read_lock();
2512 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2513 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2514 	if (usr_qf_name)
2515 		seq_show_option(seq, "usrjquota", usr_qf_name);
2516 	if (grp_qf_name)
2517 		seq_show_option(seq, "grpjquota", grp_qf_name);
2518 	rcu_read_unlock();
2519 #endif
2520 }
2521 
2522 static const char *token2str(int token)
2523 {
2524 	const struct match_token *t;
2525 
2526 	for (t = tokens; t->token != Opt_err; t++)
2527 		if (t->token == token && !strchr(t->pattern, '='))
2528 			break;
2529 	return t->pattern;
2530 }
2531 
2532 /*
2533  * Show an option if
2534  *  - it's set to a non-default value OR
2535  *  - if the per-sb default is different from the global default
2536  */
2537 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2538 			      int nodefs)
2539 {
2540 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2541 	struct ext4_super_block *es = sbi->s_es;
2542 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2543 	const struct mount_opts *m;
2544 	char sep = nodefs ? '\n' : ',';
2545 
2546 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2547 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2548 
2549 	if (sbi->s_sb_block != 1)
2550 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2551 
2552 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2553 		int want_set = m->flags & MOPT_SET;
2554 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2555 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2556 			continue;
2557 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2558 			continue; /* skip if same as the default */
2559 		if ((want_set &&
2560 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2561 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2562 			continue; /* select Opt_noFoo vs Opt_Foo */
2563 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2564 	}
2565 
2566 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2567 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2568 		SEQ_OPTS_PRINT("resuid=%u",
2569 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2570 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2571 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2572 		SEQ_OPTS_PRINT("resgid=%u",
2573 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2574 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2575 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2576 		SEQ_OPTS_PUTS("errors=remount-ro");
2577 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2578 		SEQ_OPTS_PUTS("errors=continue");
2579 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2580 		SEQ_OPTS_PUTS("errors=panic");
2581 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2582 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2583 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2584 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2585 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2586 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2587 	if (sb->s_flags & SB_I_VERSION)
2588 		SEQ_OPTS_PUTS("i_version");
2589 	if (nodefs || sbi->s_stripe)
2590 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2591 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2592 			(sbi->s_mount_opt ^ def_mount_opt)) {
2593 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2594 			SEQ_OPTS_PUTS("data=journal");
2595 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2596 			SEQ_OPTS_PUTS("data=ordered");
2597 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2598 			SEQ_OPTS_PUTS("data=writeback");
2599 	}
2600 	if (nodefs ||
2601 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2602 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2603 			       sbi->s_inode_readahead_blks);
2604 
2605 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2606 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2607 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2608 	if (nodefs || sbi->s_max_dir_size_kb)
2609 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2610 	if (test_opt(sb, DATA_ERR_ABORT))
2611 		SEQ_OPTS_PUTS("data_err=abort");
2612 
2613 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2614 
2615 	if (sb->s_flags & SB_INLINECRYPT)
2616 		SEQ_OPTS_PUTS("inlinecrypt");
2617 
2618 	if (test_opt(sb, DAX_ALWAYS)) {
2619 		if (IS_EXT2_SB(sb))
2620 			SEQ_OPTS_PUTS("dax");
2621 		else
2622 			SEQ_OPTS_PUTS("dax=always");
2623 	} else if (test_opt2(sb, DAX_NEVER)) {
2624 		SEQ_OPTS_PUTS("dax=never");
2625 	} else if (test_opt2(sb, DAX_INODE)) {
2626 		SEQ_OPTS_PUTS("dax=inode");
2627 	}
2628 	ext4_show_quota_options(seq, sb);
2629 	return 0;
2630 }
2631 
2632 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2633 {
2634 	return _ext4_show_options(seq, root->d_sb, 0);
2635 }
2636 
2637 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2638 {
2639 	struct super_block *sb = seq->private;
2640 	int rc;
2641 
2642 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2643 	rc = _ext4_show_options(seq, sb, 1);
2644 	seq_puts(seq, "\n");
2645 	return rc;
2646 }
2647 
2648 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2649 			    int read_only)
2650 {
2651 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2652 	int err = 0;
2653 
2654 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2655 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2656 			 "forcing read-only mode");
2657 		err = -EROFS;
2658 		goto done;
2659 	}
2660 	if (read_only)
2661 		goto done;
2662 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2663 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2664 			 "running e2fsck is recommended");
2665 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2666 		ext4_msg(sb, KERN_WARNING,
2667 			 "warning: mounting fs with errors, "
2668 			 "running e2fsck is recommended");
2669 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2670 		 le16_to_cpu(es->s_mnt_count) >=
2671 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2672 		ext4_msg(sb, KERN_WARNING,
2673 			 "warning: maximal mount count reached, "
2674 			 "running e2fsck is recommended");
2675 	else if (le32_to_cpu(es->s_checkinterval) &&
2676 		 (ext4_get_tstamp(es, s_lastcheck) +
2677 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2678 		ext4_msg(sb, KERN_WARNING,
2679 			 "warning: checktime reached, "
2680 			 "running e2fsck is recommended");
2681 	if (!sbi->s_journal)
2682 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2683 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2684 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2685 	le16_add_cpu(&es->s_mnt_count, 1);
2686 	ext4_update_tstamp(es, s_mtime);
2687 	if (sbi->s_journal)
2688 		ext4_set_feature_journal_needs_recovery(sb);
2689 
2690 	err = ext4_commit_super(sb);
2691 done:
2692 	if (test_opt(sb, DEBUG))
2693 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2694 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2695 			sb->s_blocksize,
2696 			sbi->s_groups_count,
2697 			EXT4_BLOCKS_PER_GROUP(sb),
2698 			EXT4_INODES_PER_GROUP(sb),
2699 			sbi->s_mount_opt, sbi->s_mount_opt2);
2700 
2701 	cleancache_init_fs(sb);
2702 	return err;
2703 }
2704 
2705 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2706 {
2707 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2708 	struct flex_groups **old_groups, **new_groups;
2709 	int size, i, j;
2710 
2711 	if (!sbi->s_log_groups_per_flex)
2712 		return 0;
2713 
2714 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2715 	if (size <= sbi->s_flex_groups_allocated)
2716 		return 0;
2717 
2718 	new_groups = kvzalloc(roundup_pow_of_two(size *
2719 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2720 	if (!new_groups) {
2721 		ext4_msg(sb, KERN_ERR,
2722 			 "not enough memory for %d flex group pointers", size);
2723 		return -ENOMEM;
2724 	}
2725 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2726 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2727 					 sizeof(struct flex_groups)),
2728 					 GFP_KERNEL);
2729 		if (!new_groups[i]) {
2730 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2731 				kvfree(new_groups[j]);
2732 			kvfree(new_groups);
2733 			ext4_msg(sb, KERN_ERR,
2734 				 "not enough memory for %d flex groups", size);
2735 			return -ENOMEM;
2736 		}
2737 	}
2738 	rcu_read_lock();
2739 	old_groups = rcu_dereference(sbi->s_flex_groups);
2740 	if (old_groups)
2741 		memcpy(new_groups, old_groups,
2742 		       (sbi->s_flex_groups_allocated *
2743 			sizeof(struct flex_groups *)));
2744 	rcu_read_unlock();
2745 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2746 	sbi->s_flex_groups_allocated = size;
2747 	if (old_groups)
2748 		ext4_kvfree_array_rcu(old_groups);
2749 	return 0;
2750 }
2751 
2752 static int ext4_fill_flex_info(struct super_block *sb)
2753 {
2754 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2755 	struct ext4_group_desc *gdp = NULL;
2756 	struct flex_groups *fg;
2757 	ext4_group_t flex_group;
2758 	int i, err;
2759 
2760 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2761 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2762 		sbi->s_log_groups_per_flex = 0;
2763 		return 1;
2764 	}
2765 
2766 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2767 	if (err)
2768 		goto failed;
2769 
2770 	for (i = 0; i < sbi->s_groups_count; i++) {
2771 		gdp = ext4_get_group_desc(sb, i, NULL);
2772 
2773 		flex_group = ext4_flex_group(sbi, i);
2774 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2775 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2776 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2777 			     &fg->free_clusters);
2778 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2779 	}
2780 
2781 	return 1;
2782 failed:
2783 	return 0;
2784 }
2785 
2786 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2787 				   struct ext4_group_desc *gdp)
2788 {
2789 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2790 	__u16 crc = 0;
2791 	__le32 le_group = cpu_to_le32(block_group);
2792 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2793 
2794 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2795 		/* Use new metadata_csum algorithm */
2796 		__u32 csum32;
2797 		__u16 dummy_csum = 0;
2798 
2799 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2800 				     sizeof(le_group));
2801 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2802 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2803 				     sizeof(dummy_csum));
2804 		offset += sizeof(dummy_csum);
2805 		if (offset < sbi->s_desc_size)
2806 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2807 					     sbi->s_desc_size - offset);
2808 
2809 		crc = csum32 & 0xFFFF;
2810 		goto out;
2811 	}
2812 
2813 	/* old crc16 code */
2814 	if (!ext4_has_feature_gdt_csum(sb))
2815 		return 0;
2816 
2817 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2818 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2819 	crc = crc16(crc, (__u8 *)gdp, offset);
2820 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2821 	/* for checksum of struct ext4_group_desc do the rest...*/
2822 	if (ext4_has_feature_64bit(sb) &&
2823 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2824 		crc = crc16(crc, (__u8 *)gdp + offset,
2825 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2826 				offset);
2827 
2828 out:
2829 	return cpu_to_le16(crc);
2830 }
2831 
2832 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2833 				struct ext4_group_desc *gdp)
2834 {
2835 	if (ext4_has_group_desc_csum(sb) &&
2836 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2837 		return 0;
2838 
2839 	return 1;
2840 }
2841 
2842 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2843 			      struct ext4_group_desc *gdp)
2844 {
2845 	if (!ext4_has_group_desc_csum(sb))
2846 		return;
2847 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2848 }
2849 
2850 /* Called at mount-time, super-block is locked */
2851 static int ext4_check_descriptors(struct super_block *sb,
2852 				  ext4_fsblk_t sb_block,
2853 				  ext4_group_t *first_not_zeroed)
2854 {
2855 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2856 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2857 	ext4_fsblk_t last_block;
2858 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2859 	ext4_fsblk_t block_bitmap;
2860 	ext4_fsblk_t inode_bitmap;
2861 	ext4_fsblk_t inode_table;
2862 	int flexbg_flag = 0;
2863 	ext4_group_t i, grp = sbi->s_groups_count;
2864 
2865 	if (ext4_has_feature_flex_bg(sb))
2866 		flexbg_flag = 1;
2867 
2868 	ext4_debug("Checking group descriptors");
2869 
2870 	for (i = 0; i < sbi->s_groups_count; i++) {
2871 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2872 
2873 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2874 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2875 		else
2876 			last_block = first_block +
2877 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2878 
2879 		if ((grp == sbi->s_groups_count) &&
2880 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2881 			grp = i;
2882 
2883 		block_bitmap = ext4_block_bitmap(sb, gdp);
2884 		if (block_bitmap == sb_block) {
2885 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2886 				 "Block bitmap for group %u overlaps "
2887 				 "superblock", i);
2888 			if (!sb_rdonly(sb))
2889 				return 0;
2890 		}
2891 		if (block_bitmap >= sb_block + 1 &&
2892 		    block_bitmap <= last_bg_block) {
2893 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2894 				 "Block bitmap for group %u overlaps "
2895 				 "block group descriptors", i);
2896 			if (!sb_rdonly(sb))
2897 				return 0;
2898 		}
2899 		if (block_bitmap < first_block || block_bitmap > last_block) {
2900 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2901 			       "Block bitmap for group %u not in group "
2902 			       "(block %llu)!", i, block_bitmap);
2903 			return 0;
2904 		}
2905 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2906 		if (inode_bitmap == sb_block) {
2907 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2908 				 "Inode bitmap for group %u overlaps "
2909 				 "superblock", i);
2910 			if (!sb_rdonly(sb))
2911 				return 0;
2912 		}
2913 		if (inode_bitmap >= sb_block + 1 &&
2914 		    inode_bitmap <= last_bg_block) {
2915 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2916 				 "Inode bitmap for group %u overlaps "
2917 				 "block group descriptors", i);
2918 			if (!sb_rdonly(sb))
2919 				return 0;
2920 		}
2921 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2922 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2923 			       "Inode bitmap for group %u not in group "
2924 			       "(block %llu)!", i, inode_bitmap);
2925 			return 0;
2926 		}
2927 		inode_table = ext4_inode_table(sb, gdp);
2928 		if (inode_table == sb_block) {
2929 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2930 				 "Inode table for group %u overlaps "
2931 				 "superblock", i);
2932 			if (!sb_rdonly(sb))
2933 				return 0;
2934 		}
2935 		if (inode_table >= sb_block + 1 &&
2936 		    inode_table <= last_bg_block) {
2937 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2938 				 "Inode table for group %u overlaps "
2939 				 "block group descriptors", i);
2940 			if (!sb_rdonly(sb))
2941 				return 0;
2942 		}
2943 		if (inode_table < first_block ||
2944 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2945 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2946 			       "Inode table for group %u not in group "
2947 			       "(block %llu)!", i, inode_table);
2948 			return 0;
2949 		}
2950 		ext4_lock_group(sb, i);
2951 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2952 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2953 				 "Checksum for group %u failed (%u!=%u)",
2954 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2955 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2956 			if (!sb_rdonly(sb)) {
2957 				ext4_unlock_group(sb, i);
2958 				return 0;
2959 			}
2960 		}
2961 		ext4_unlock_group(sb, i);
2962 		if (!flexbg_flag)
2963 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2964 	}
2965 	if (NULL != first_not_zeroed)
2966 		*first_not_zeroed = grp;
2967 	return 1;
2968 }
2969 
2970 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2971  * the superblock) which were deleted from all directories, but held open by
2972  * a process at the time of a crash.  We walk the list and try to delete these
2973  * inodes at recovery time (only with a read-write filesystem).
2974  *
2975  * In order to keep the orphan inode chain consistent during traversal (in
2976  * case of crash during recovery), we link each inode into the superblock
2977  * orphan list_head and handle it the same way as an inode deletion during
2978  * normal operation (which journals the operations for us).
2979  *
2980  * We only do an iget() and an iput() on each inode, which is very safe if we
2981  * accidentally point at an in-use or already deleted inode.  The worst that
2982  * can happen in this case is that we get a "bit already cleared" message from
2983  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2984  * e2fsck was run on this filesystem, and it must have already done the orphan
2985  * inode cleanup for us, so we can safely abort without any further action.
2986  */
2987 static void ext4_orphan_cleanup(struct super_block *sb,
2988 				struct ext4_super_block *es)
2989 {
2990 	unsigned int s_flags = sb->s_flags;
2991 	int ret, nr_orphans = 0, nr_truncates = 0;
2992 #ifdef CONFIG_QUOTA
2993 	int quota_update = 0;
2994 	int i;
2995 #endif
2996 	if (!es->s_last_orphan) {
2997 		jbd_debug(4, "no orphan inodes to clean up\n");
2998 		return;
2999 	}
3000 
3001 	if (bdev_read_only(sb->s_bdev)) {
3002 		ext4_msg(sb, KERN_ERR, "write access "
3003 			"unavailable, skipping orphan cleanup");
3004 		return;
3005 	}
3006 
3007 	/* Check if feature set would not allow a r/w mount */
3008 	if (!ext4_feature_set_ok(sb, 0)) {
3009 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
3010 			 "unknown ROCOMPAT features");
3011 		return;
3012 	}
3013 
3014 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3015 		/* don't clear list on RO mount w/ errors */
3016 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
3017 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
3018 				  "clearing orphan list.\n");
3019 			es->s_last_orphan = 0;
3020 		}
3021 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3022 		return;
3023 	}
3024 
3025 	if (s_flags & SB_RDONLY) {
3026 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
3027 		sb->s_flags &= ~SB_RDONLY;
3028 	}
3029 #ifdef CONFIG_QUOTA
3030 	/*
3031 	 * Turn on quotas which were not enabled for read-only mounts if
3032 	 * filesystem has quota feature, so that they are updated correctly.
3033 	 */
3034 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
3035 		int ret = ext4_enable_quotas(sb);
3036 
3037 		if (!ret)
3038 			quota_update = 1;
3039 		else
3040 			ext4_msg(sb, KERN_ERR,
3041 				"Cannot turn on quotas: error %d", ret);
3042 	}
3043 
3044 	/* Turn on journaled quotas used for old sytle */
3045 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3046 		if (EXT4_SB(sb)->s_qf_names[i]) {
3047 			int ret = ext4_quota_on_mount(sb, i);
3048 
3049 			if (!ret)
3050 				quota_update = 1;
3051 			else
3052 				ext4_msg(sb, KERN_ERR,
3053 					"Cannot turn on journaled "
3054 					"quota: type %d: error %d", i, ret);
3055 		}
3056 	}
3057 #endif
3058 
3059 	while (es->s_last_orphan) {
3060 		struct inode *inode;
3061 
3062 		/*
3063 		 * We may have encountered an error during cleanup; if
3064 		 * so, skip the rest.
3065 		 */
3066 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3067 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3068 			es->s_last_orphan = 0;
3069 			break;
3070 		}
3071 
3072 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
3073 		if (IS_ERR(inode)) {
3074 			es->s_last_orphan = 0;
3075 			break;
3076 		}
3077 
3078 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
3079 		dquot_initialize(inode);
3080 		if (inode->i_nlink) {
3081 			if (test_opt(sb, DEBUG))
3082 				ext4_msg(sb, KERN_DEBUG,
3083 					"%s: truncating inode %lu to %lld bytes",
3084 					__func__, inode->i_ino, inode->i_size);
3085 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
3086 				  inode->i_ino, inode->i_size);
3087 			inode_lock(inode);
3088 			truncate_inode_pages(inode->i_mapping, inode->i_size);
3089 			ret = ext4_truncate(inode);
3090 			if (ret) {
3091 				/*
3092 				 * We need to clean up the in-core orphan list
3093 				 * manually if ext4_truncate() failed to get a
3094 				 * transaction handle.
3095 				 */
3096 				ext4_orphan_del(NULL, inode);
3097 				ext4_std_error(inode->i_sb, ret);
3098 			}
3099 			inode_unlock(inode);
3100 			nr_truncates++;
3101 		} else {
3102 			if (test_opt(sb, DEBUG))
3103 				ext4_msg(sb, KERN_DEBUG,
3104 					"%s: deleting unreferenced inode %lu",
3105 					__func__, inode->i_ino);
3106 			jbd_debug(2, "deleting unreferenced inode %lu\n",
3107 				  inode->i_ino);
3108 			nr_orphans++;
3109 		}
3110 		iput(inode);  /* The delete magic happens here! */
3111 	}
3112 
3113 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
3114 
3115 	if (nr_orphans)
3116 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
3117 		       PLURAL(nr_orphans));
3118 	if (nr_truncates)
3119 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
3120 		       PLURAL(nr_truncates));
3121 #ifdef CONFIG_QUOTA
3122 	/* Turn off quotas if they were enabled for orphan cleanup */
3123 	if (quota_update) {
3124 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3125 			if (sb_dqopt(sb)->files[i])
3126 				dquot_quota_off(sb, i);
3127 		}
3128 	}
3129 #endif
3130 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
3131 }
3132 
3133 /*
3134  * Maximal extent format file size.
3135  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3136  * extent format containers, within a sector_t, and within i_blocks
3137  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3138  * so that won't be a limiting factor.
3139  *
3140  * However there is other limiting factor. We do store extents in the form
3141  * of starting block and length, hence the resulting length of the extent
3142  * covering maximum file size must fit into on-disk format containers as
3143  * well. Given that length is always by 1 unit bigger than max unit (because
3144  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3145  *
3146  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3147  */
3148 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3149 {
3150 	loff_t res;
3151 	loff_t upper_limit = MAX_LFS_FILESIZE;
3152 
3153 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3154 
3155 	if (!has_huge_files) {
3156 		upper_limit = (1LL << 32) - 1;
3157 
3158 		/* total blocks in file system block size */
3159 		upper_limit >>= (blkbits - 9);
3160 		upper_limit <<= blkbits;
3161 	}
3162 
3163 	/*
3164 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3165 	 * by one fs block, so ee_len can cover the extent of maximum file
3166 	 * size
3167 	 */
3168 	res = (1LL << 32) - 1;
3169 	res <<= blkbits;
3170 
3171 	/* Sanity check against vm- & vfs- imposed limits */
3172 	if (res > upper_limit)
3173 		res = upper_limit;
3174 
3175 	return res;
3176 }
3177 
3178 /*
3179  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3180  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3181  * We need to be 1 filesystem block less than the 2^48 sector limit.
3182  */
3183 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3184 {
3185 	loff_t res = EXT4_NDIR_BLOCKS;
3186 	int meta_blocks;
3187 	loff_t upper_limit;
3188 	/* This is calculated to be the largest file size for a dense, block
3189 	 * mapped file such that the file's total number of 512-byte sectors,
3190 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3191 	 *
3192 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3193 	 * number of 512-byte sectors of the file.
3194 	 */
3195 
3196 	if (!has_huge_files) {
3197 		/*
3198 		 * !has_huge_files or implies that the inode i_block field
3199 		 * represents total file blocks in 2^32 512-byte sectors ==
3200 		 * size of vfs inode i_blocks * 8
3201 		 */
3202 		upper_limit = (1LL << 32) - 1;
3203 
3204 		/* total blocks in file system block size */
3205 		upper_limit >>= (bits - 9);
3206 
3207 	} else {
3208 		/*
3209 		 * We use 48 bit ext4_inode i_blocks
3210 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3211 		 * represent total number of blocks in
3212 		 * file system block size
3213 		 */
3214 		upper_limit = (1LL << 48) - 1;
3215 
3216 	}
3217 
3218 	/* indirect blocks */
3219 	meta_blocks = 1;
3220 	/* double indirect blocks */
3221 	meta_blocks += 1 + (1LL << (bits-2));
3222 	/* tripple indirect blocks */
3223 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3224 
3225 	upper_limit -= meta_blocks;
3226 	upper_limit <<= bits;
3227 
3228 	res += 1LL << (bits-2);
3229 	res += 1LL << (2*(bits-2));
3230 	res += 1LL << (3*(bits-2));
3231 	res <<= bits;
3232 	if (res > upper_limit)
3233 		res = upper_limit;
3234 
3235 	if (res > MAX_LFS_FILESIZE)
3236 		res = MAX_LFS_FILESIZE;
3237 
3238 	return res;
3239 }
3240 
3241 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3242 				   ext4_fsblk_t logical_sb_block, int nr)
3243 {
3244 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3245 	ext4_group_t bg, first_meta_bg;
3246 	int has_super = 0;
3247 
3248 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3249 
3250 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3251 		return logical_sb_block + nr + 1;
3252 	bg = sbi->s_desc_per_block * nr;
3253 	if (ext4_bg_has_super(sb, bg))
3254 		has_super = 1;
3255 
3256 	/*
3257 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3258 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3259 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3260 	 * compensate.
3261 	 */
3262 	if (sb->s_blocksize == 1024 && nr == 0 &&
3263 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3264 		has_super++;
3265 
3266 	return (has_super + ext4_group_first_block_no(sb, bg));
3267 }
3268 
3269 /**
3270  * ext4_get_stripe_size: Get the stripe size.
3271  * @sbi: In memory super block info
3272  *
3273  * If we have specified it via mount option, then
3274  * use the mount option value. If the value specified at mount time is
3275  * greater than the blocks per group use the super block value.
3276  * If the super block value is greater than blocks per group return 0.
3277  * Allocator needs it be less than blocks per group.
3278  *
3279  */
3280 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3281 {
3282 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3283 	unsigned long stripe_width =
3284 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3285 	int ret;
3286 
3287 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3288 		ret = sbi->s_stripe;
3289 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3290 		ret = stripe_width;
3291 	else if (stride && stride <= sbi->s_blocks_per_group)
3292 		ret = stride;
3293 	else
3294 		ret = 0;
3295 
3296 	/*
3297 	 * If the stripe width is 1, this makes no sense and
3298 	 * we set it to 0 to turn off stripe handling code.
3299 	 */
3300 	if (ret <= 1)
3301 		ret = 0;
3302 
3303 	return ret;
3304 }
3305 
3306 /*
3307  * Check whether this filesystem can be mounted based on
3308  * the features present and the RDONLY/RDWR mount requested.
3309  * Returns 1 if this filesystem can be mounted as requested,
3310  * 0 if it cannot be.
3311  */
3312 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3313 {
3314 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3315 		ext4_msg(sb, KERN_ERR,
3316 			"Couldn't mount because of "
3317 			"unsupported optional features (%x)",
3318 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3319 			~EXT4_FEATURE_INCOMPAT_SUPP));
3320 		return 0;
3321 	}
3322 
3323 #ifndef CONFIG_UNICODE
3324 	if (ext4_has_feature_casefold(sb)) {
3325 		ext4_msg(sb, KERN_ERR,
3326 			 "Filesystem with casefold feature cannot be "
3327 			 "mounted without CONFIG_UNICODE");
3328 		return 0;
3329 	}
3330 #endif
3331 
3332 	if (readonly)
3333 		return 1;
3334 
3335 	if (ext4_has_feature_readonly(sb)) {
3336 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3337 		sb->s_flags |= SB_RDONLY;
3338 		return 1;
3339 	}
3340 
3341 	/* Check that feature set is OK for a read-write mount */
3342 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3343 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3344 			 "unsupported optional features (%x)",
3345 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3346 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3347 		return 0;
3348 	}
3349 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3350 		ext4_msg(sb, KERN_ERR,
3351 			 "Can't support bigalloc feature without "
3352 			 "extents feature\n");
3353 		return 0;
3354 	}
3355 
3356 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3357 	if (!readonly && (ext4_has_feature_quota(sb) ||
3358 			  ext4_has_feature_project(sb))) {
3359 		ext4_msg(sb, KERN_ERR,
3360 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3361 		return 0;
3362 	}
3363 #endif  /* CONFIG_QUOTA */
3364 	return 1;
3365 }
3366 
3367 /*
3368  * This function is called once a day if we have errors logged
3369  * on the file system
3370  */
3371 static void print_daily_error_info(struct timer_list *t)
3372 {
3373 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3374 	struct super_block *sb = sbi->s_sb;
3375 	struct ext4_super_block *es = sbi->s_es;
3376 
3377 	if (es->s_error_count)
3378 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3379 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3380 			 le32_to_cpu(es->s_error_count));
3381 	if (es->s_first_error_time) {
3382 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3383 		       sb->s_id,
3384 		       ext4_get_tstamp(es, s_first_error_time),
3385 		       (int) sizeof(es->s_first_error_func),
3386 		       es->s_first_error_func,
3387 		       le32_to_cpu(es->s_first_error_line));
3388 		if (es->s_first_error_ino)
3389 			printk(KERN_CONT ": inode %u",
3390 			       le32_to_cpu(es->s_first_error_ino));
3391 		if (es->s_first_error_block)
3392 			printk(KERN_CONT ": block %llu", (unsigned long long)
3393 			       le64_to_cpu(es->s_first_error_block));
3394 		printk(KERN_CONT "\n");
3395 	}
3396 	if (es->s_last_error_time) {
3397 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3398 		       sb->s_id,
3399 		       ext4_get_tstamp(es, s_last_error_time),
3400 		       (int) sizeof(es->s_last_error_func),
3401 		       es->s_last_error_func,
3402 		       le32_to_cpu(es->s_last_error_line));
3403 		if (es->s_last_error_ino)
3404 			printk(KERN_CONT ": inode %u",
3405 			       le32_to_cpu(es->s_last_error_ino));
3406 		if (es->s_last_error_block)
3407 			printk(KERN_CONT ": block %llu", (unsigned long long)
3408 			       le64_to_cpu(es->s_last_error_block));
3409 		printk(KERN_CONT "\n");
3410 	}
3411 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3412 }
3413 
3414 /* Find next suitable group and run ext4_init_inode_table */
3415 static int ext4_run_li_request(struct ext4_li_request *elr)
3416 {
3417 	struct ext4_group_desc *gdp = NULL;
3418 	struct super_block *sb = elr->lr_super;
3419 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3420 	ext4_group_t group = elr->lr_next_group;
3421 	unsigned long timeout = 0;
3422 	unsigned int prefetch_ios = 0;
3423 	int ret = 0;
3424 
3425 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3426 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3427 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3428 		if (prefetch_ios)
3429 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3430 					      prefetch_ios);
3431 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3432 					    prefetch_ios);
3433 		if (group >= elr->lr_next_group) {
3434 			ret = 1;
3435 			if (elr->lr_first_not_zeroed != ngroups &&
3436 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3437 				elr->lr_next_group = elr->lr_first_not_zeroed;
3438 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3439 				ret = 0;
3440 			}
3441 		}
3442 		return ret;
3443 	}
3444 
3445 	for (; group < ngroups; group++) {
3446 		gdp = ext4_get_group_desc(sb, group, NULL);
3447 		if (!gdp) {
3448 			ret = 1;
3449 			break;
3450 		}
3451 
3452 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3453 			break;
3454 	}
3455 
3456 	if (group >= ngroups)
3457 		ret = 1;
3458 
3459 	if (!ret) {
3460 		timeout = jiffies;
3461 		ret = ext4_init_inode_table(sb, group,
3462 					    elr->lr_timeout ? 0 : 1);
3463 		trace_ext4_lazy_itable_init(sb, group);
3464 		if (elr->lr_timeout == 0) {
3465 			timeout = (jiffies - timeout) *
3466 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3467 			elr->lr_timeout = timeout;
3468 		}
3469 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3470 		elr->lr_next_group = group + 1;
3471 	}
3472 	return ret;
3473 }
3474 
3475 /*
3476  * Remove lr_request from the list_request and free the
3477  * request structure. Should be called with li_list_mtx held
3478  */
3479 static void ext4_remove_li_request(struct ext4_li_request *elr)
3480 {
3481 	if (!elr)
3482 		return;
3483 
3484 	list_del(&elr->lr_request);
3485 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3486 	kfree(elr);
3487 }
3488 
3489 static void ext4_unregister_li_request(struct super_block *sb)
3490 {
3491 	mutex_lock(&ext4_li_mtx);
3492 	if (!ext4_li_info) {
3493 		mutex_unlock(&ext4_li_mtx);
3494 		return;
3495 	}
3496 
3497 	mutex_lock(&ext4_li_info->li_list_mtx);
3498 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3499 	mutex_unlock(&ext4_li_info->li_list_mtx);
3500 	mutex_unlock(&ext4_li_mtx);
3501 }
3502 
3503 static struct task_struct *ext4_lazyinit_task;
3504 
3505 /*
3506  * This is the function where ext4lazyinit thread lives. It walks
3507  * through the request list searching for next scheduled filesystem.
3508  * When such a fs is found, run the lazy initialization request
3509  * (ext4_rn_li_request) and keep track of the time spend in this
3510  * function. Based on that time we compute next schedule time of
3511  * the request. When walking through the list is complete, compute
3512  * next waking time and put itself into sleep.
3513  */
3514 static int ext4_lazyinit_thread(void *arg)
3515 {
3516 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3517 	struct list_head *pos, *n;
3518 	struct ext4_li_request *elr;
3519 	unsigned long next_wakeup, cur;
3520 
3521 	BUG_ON(NULL == eli);
3522 
3523 cont_thread:
3524 	while (true) {
3525 		next_wakeup = MAX_JIFFY_OFFSET;
3526 
3527 		mutex_lock(&eli->li_list_mtx);
3528 		if (list_empty(&eli->li_request_list)) {
3529 			mutex_unlock(&eli->li_list_mtx);
3530 			goto exit_thread;
3531 		}
3532 		list_for_each_safe(pos, n, &eli->li_request_list) {
3533 			int err = 0;
3534 			int progress = 0;
3535 			elr = list_entry(pos, struct ext4_li_request,
3536 					 lr_request);
3537 
3538 			if (time_before(jiffies, elr->lr_next_sched)) {
3539 				if (time_before(elr->lr_next_sched, next_wakeup))
3540 					next_wakeup = elr->lr_next_sched;
3541 				continue;
3542 			}
3543 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3544 				if (sb_start_write_trylock(elr->lr_super)) {
3545 					progress = 1;
3546 					/*
3547 					 * We hold sb->s_umount, sb can not
3548 					 * be removed from the list, it is
3549 					 * now safe to drop li_list_mtx
3550 					 */
3551 					mutex_unlock(&eli->li_list_mtx);
3552 					err = ext4_run_li_request(elr);
3553 					sb_end_write(elr->lr_super);
3554 					mutex_lock(&eli->li_list_mtx);
3555 					n = pos->next;
3556 				}
3557 				up_read((&elr->lr_super->s_umount));
3558 			}
3559 			/* error, remove the lazy_init job */
3560 			if (err) {
3561 				ext4_remove_li_request(elr);
3562 				continue;
3563 			}
3564 			if (!progress) {
3565 				elr->lr_next_sched = jiffies +
3566 					(prandom_u32()
3567 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3568 			}
3569 			if (time_before(elr->lr_next_sched, next_wakeup))
3570 				next_wakeup = elr->lr_next_sched;
3571 		}
3572 		mutex_unlock(&eli->li_list_mtx);
3573 
3574 		try_to_freeze();
3575 
3576 		cur = jiffies;
3577 		if ((time_after_eq(cur, next_wakeup)) ||
3578 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3579 			cond_resched();
3580 			continue;
3581 		}
3582 
3583 		schedule_timeout_interruptible(next_wakeup - cur);
3584 
3585 		if (kthread_should_stop()) {
3586 			ext4_clear_request_list();
3587 			goto exit_thread;
3588 		}
3589 	}
3590 
3591 exit_thread:
3592 	/*
3593 	 * It looks like the request list is empty, but we need
3594 	 * to check it under the li_list_mtx lock, to prevent any
3595 	 * additions into it, and of course we should lock ext4_li_mtx
3596 	 * to atomically free the list and ext4_li_info, because at
3597 	 * this point another ext4 filesystem could be registering
3598 	 * new one.
3599 	 */
3600 	mutex_lock(&ext4_li_mtx);
3601 	mutex_lock(&eli->li_list_mtx);
3602 	if (!list_empty(&eli->li_request_list)) {
3603 		mutex_unlock(&eli->li_list_mtx);
3604 		mutex_unlock(&ext4_li_mtx);
3605 		goto cont_thread;
3606 	}
3607 	mutex_unlock(&eli->li_list_mtx);
3608 	kfree(ext4_li_info);
3609 	ext4_li_info = NULL;
3610 	mutex_unlock(&ext4_li_mtx);
3611 
3612 	return 0;
3613 }
3614 
3615 static void ext4_clear_request_list(void)
3616 {
3617 	struct list_head *pos, *n;
3618 	struct ext4_li_request *elr;
3619 
3620 	mutex_lock(&ext4_li_info->li_list_mtx);
3621 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3622 		elr = list_entry(pos, struct ext4_li_request,
3623 				 lr_request);
3624 		ext4_remove_li_request(elr);
3625 	}
3626 	mutex_unlock(&ext4_li_info->li_list_mtx);
3627 }
3628 
3629 static int ext4_run_lazyinit_thread(void)
3630 {
3631 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3632 					 ext4_li_info, "ext4lazyinit");
3633 	if (IS_ERR(ext4_lazyinit_task)) {
3634 		int err = PTR_ERR(ext4_lazyinit_task);
3635 		ext4_clear_request_list();
3636 		kfree(ext4_li_info);
3637 		ext4_li_info = NULL;
3638 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3639 				 "initialization thread\n",
3640 				 err);
3641 		return err;
3642 	}
3643 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3644 	return 0;
3645 }
3646 
3647 /*
3648  * Check whether it make sense to run itable init. thread or not.
3649  * If there is at least one uninitialized inode table, return
3650  * corresponding group number, else the loop goes through all
3651  * groups and return total number of groups.
3652  */
3653 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3654 {
3655 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3656 	struct ext4_group_desc *gdp = NULL;
3657 
3658 	if (!ext4_has_group_desc_csum(sb))
3659 		return ngroups;
3660 
3661 	for (group = 0; group < ngroups; group++) {
3662 		gdp = ext4_get_group_desc(sb, group, NULL);
3663 		if (!gdp)
3664 			continue;
3665 
3666 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3667 			break;
3668 	}
3669 
3670 	return group;
3671 }
3672 
3673 static int ext4_li_info_new(void)
3674 {
3675 	struct ext4_lazy_init *eli = NULL;
3676 
3677 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3678 	if (!eli)
3679 		return -ENOMEM;
3680 
3681 	INIT_LIST_HEAD(&eli->li_request_list);
3682 	mutex_init(&eli->li_list_mtx);
3683 
3684 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3685 
3686 	ext4_li_info = eli;
3687 
3688 	return 0;
3689 }
3690 
3691 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3692 					    ext4_group_t start)
3693 {
3694 	struct ext4_li_request *elr;
3695 
3696 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3697 	if (!elr)
3698 		return NULL;
3699 
3700 	elr->lr_super = sb;
3701 	elr->lr_first_not_zeroed = start;
3702 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3703 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3704 		elr->lr_next_group = start;
3705 	} else {
3706 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3707 	}
3708 
3709 	/*
3710 	 * Randomize first schedule time of the request to
3711 	 * spread the inode table initialization requests
3712 	 * better.
3713 	 */
3714 	elr->lr_next_sched = jiffies + (prandom_u32() %
3715 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3716 	return elr;
3717 }
3718 
3719 int ext4_register_li_request(struct super_block *sb,
3720 			     ext4_group_t first_not_zeroed)
3721 {
3722 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3723 	struct ext4_li_request *elr = NULL;
3724 	ext4_group_t ngroups = sbi->s_groups_count;
3725 	int ret = 0;
3726 
3727 	mutex_lock(&ext4_li_mtx);
3728 	if (sbi->s_li_request != NULL) {
3729 		/*
3730 		 * Reset timeout so it can be computed again, because
3731 		 * s_li_wait_mult might have changed.
3732 		 */
3733 		sbi->s_li_request->lr_timeout = 0;
3734 		goto out;
3735 	}
3736 
3737 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3738 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3739 	     !test_opt(sb, INIT_INODE_TABLE)))
3740 		goto out;
3741 
3742 	elr = ext4_li_request_new(sb, first_not_zeroed);
3743 	if (!elr) {
3744 		ret = -ENOMEM;
3745 		goto out;
3746 	}
3747 
3748 	if (NULL == ext4_li_info) {
3749 		ret = ext4_li_info_new();
3750 		if (ret)
3751 			goto out;
3752 	}
3753 
3754 	mutex_lock(&ext4_li_info->li_list_mtx);
3755 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3756 	mutex_unlock(&ext4_li_info->li_list_mtx);
3757 
3758 	sbi->s_li_request = elr;
3759 	/*
3760 	 * set elr to NULL here since it has been inserted to
3761 	 * the request_list and the removal and free of it is
3762 	 * handled by ext4_clear_request_list from now on.
3763 	 */
3764 	elr = NULL;
3765 
3766 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3767 		ret = ext4_run_lazyinit_thread();
3768 		if (ret)
3769 			goto out;
3770 	}
3771 out:
3772 	mutex_unlock(&ext4_li_mtx);
3773 	if (ret)
3774 		kfree(elr);
3775 	return ret;
3776 }
3777 
3778 /*
3779  * We do not need to lock anything since this is called on
3780  * module unload.
3781  */
3782 static void ext4_destroy_lazyinit_thread(void)
3783 {
3784 	/*
3785 	 * If thread exited earlier
3786 	 * there's nothing to be done.
3787 	 */
3788 	if (!ext4_li_info || !ext4_lazyinit_task)
3789 		return;
3790 
3791 	kthread_stop(ext4_lazyinit_task);
3792 }
3793 
3794 static int set_journal_csum_feature_set(struct super_block *sb)
3795 {
3796 	int ret = 1;
3797 	int compat, incompat;
3798 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3799 
3800 	if (ext4_has_metadata_csum(sb)) {
3801 		/* journal checksum v3 */
3802 		compat = 0;
3803 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3804 	} else {
3805 		/* journal checksum v1 */
3806 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3807 		incompat = 0;
3808 	}
3809 
3810 	jbd2_journal_clear_features(sbi->s_journal,
3811 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3812 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3813 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3814 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3815 		ret = jbd2_journal_set_features(sbi->s_journal,
3816 				compat, 0,
3817 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3818 				incompat);
3819 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3820 		ret = jbd2_journal_set_features(sbi->s_journal,
3821 				compat, 0,
3822 				incompat);
3823 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3824 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3825 	} else {
3826 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3827 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3828 	}
3829 
3830 	return ret;
3831 }
3832 
3833 /*
3834  * Note: calculating the overhead so we can be compatible with
3835  * historical BSD practice is quite difficult in the face of
3836  * clusters/bigalloc.  This is because multiple metadata blocks from
3837  * different block group can end up in the same allocation cluster.
3838  * Calculating the exact overhead in the face of clustered allocation
3839  * requires either O(all block bitmaps) in memory or O(number of block
3840  * groups**2) in time.  We will still calculate the superblock for
3841  * older file systems --- and if we come across with a bigalloc file
3842  * system with zero in s_overhead_clusters the estimate will be close to
3843  * correct especially for very large cluster sizes --- but for newer
3844  * file systems, it's better to calculate this figure once at mkfs
3845  * time, and store it in the superblock.  If the superblock value is
3846  * present (even for non-bigalloc file systems), we will use it.
3847  */
3848 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3849 			  char *buf)
3850 {
3851 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3852 	struct ext4_group_desc	*gdp;
3853 	ext4_fsblk_t		first_block, last_block, b;
3854 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3855 	int			s, j, count = 0;
3856 
3857 	if (!ext4_has_feature_bigalloc(sb))
3858 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3859 			sbi->s_itb_per_group + 2);
3860 
3861 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3862 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3863 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3864 	for (i = 0; i < ngroups; i++) {
3865 		gdp = ext4_get_group_desc(sb, i, NULL);
3866 		b = ext4_block_bitmap(sb, gdp);
3867 		if (b >= first_block && b <= last_block) {
3868 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3869 			count++;
3870 		}
3871 		b = ext4_inode_bitmap(sb, gdp);
3872 		if (b >= first_block && b <= last_block) {
3873 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3874 			count++;
3875 		}
3876 		b = ext4_inode_table(sb, gdp);
3877 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3878 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3879 				int c = EXT4_B2C(sbi, b - first_block);
3880 				ext4_set_bit(c, buf);
3881 				count++;
3882 			}
3883 		if (i != grp)
3884 			continue;
3885 		s = 0;
3886 		if (ext4_bg_has_super(sb, grp)) {
3887 			ext4_set_bit(s++, buf);
3888 			count++;
3889 		}
3890 		j = ext4_bg_num_gdb(sb, grp);
3891 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3892 			ext4_error(sb, "Invalid number of block group "
3893 				   "descriptor blocks: %d", j);
3894 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3895 		}
3896 		count += j;
3897 		for (; j > 0; j--)
3898 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3899 	}
3900 	if (!count)
3901 		return 0;
3902 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3903 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3904 }
3905 
3906 /*
3907  * Compute the overhead and stash it in sbi->s_overhead
3908  */
3909 int ext4_calculate_overhead(struct super_block *sb)
3910 {
3911 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3912 	struct ext4_super_block *es = sbi->s_es;
3913 	struct inode *j_inode;
3914 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3915 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3916 	ext4_fsblk_t overhead = 0;
3917 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3918 
3919 	if (!buf)
3920 		return -ENOMEM;
3921 
3922 	/*
3923 	 * Compute the overhead (FS structures).  This is constant
3924 	 * for a given filesystem unless the number of block groups
3925 	 * changes so we cache the previous value until it does.
3926 	 */
3927 
3928 	/*
3929 	 * All of the blocks before first_data_block are overhead
3930 	 */
3931 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3932 
3933 	/*
3934 	 * Add the overhead found in each block group
3935 	 */
3936 	for (i = 0; i < ngroups; i++) {
3937 		int blks;
3938 
3939 		blks = count_overhead(sb, i, buf);
3940 		overhead += blks;
3941 		if (blks)
3942 			memset(buf, 0, PAGE_SIZE);
3943 		cond_resched();
3944 	}
3945 
3946 	/*
3947 	 * Add the internal journal blocks whether the journal has been
3948 	 * loaded or not
3949 	 */
3950 	if (sbi->s_journal && !sbi->s_journal_bdev)
3951 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
3952 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3953 		/* j_inum for internal journal is non-zero */
3954 		j_inode = ext4_get_journal_inode(sb, j_inum);
3955 		if (j_inode) {
3956 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3957 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3958 			iput(j_inode);
3959 		} else {
3960 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3961 		}
3962 	}
3963 	sbi->s_overhead = overhead;
3964 	smp_wmb();
3965 	free_page((unsigned long) buf);
3966 	return 0;
3967 }
3968 
3969 static void ext4_set_resv_clusters(struct super_block *sb)
3970 {
3971 	ext4_fsblk_t resv_clusters;
3972 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3973 
3974 	/*
3975 	 * There's no need to reserve anything when we aren't using extents.
3976 	 * The space estimates are exact, there are no unwritten extents,
3977 	 * hole punching doesn't need new metadata... This is needed especially
3978 	 * to keep ext2/3 backward compatibility.
3979 	 */
3980 	if (!ext4_has_feature_extents(sb))
3981 		return;
3982 	/*
3983 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3984 	 * This should cover the situations where we can not afford to run
3985 	 * out of space like for example punch hole, or converting
3986 	 * unwritten extents in delalloc path. In most cases such
3987 	 * allocation would require 1, or 2 blocks, higher numbers are
3988 	 * very rare.
3989 	 */
3990 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3991 			 sbi->s_cluster_bits);
3992 
3993 	do_div(resv_clusters, 50);
3994 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3995 
3996 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3997 }
3998 
3999 static const char *ext4_quota_mode(struct super_block *sb)
4000 {
4001 #ifdef CONFIG_QUOTA
4002 	if (!ext4_quota_capable(sb))
4003 		return "none";
4004 
4005 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4006 		return "journalled";
4007 	else
4008 		return "writeback";
4009 #else
4010 	return "disabled";
4011 #endif
4012 }
4013 
4014 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
4015 {
4016 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
4017 	char *orig_data = kstrdup(data, GFP_KERNEL);
4018 	struct buffer_head *bh, **group_desc;
4019 	struct ext4_super_block *es = NULL;
4020 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4021 	struct flex_groups **flex_groups;
4022 	ext4_fsblk_t block;
4023 	ext4_fsblk_t sb_block = get_sb_block(&data);
4024 	ext4_fsblk_t logical_sb_block;
4025 	unsigned long offset = 0;
4026 	unsigned long def_mount_opts;
4027 	struct inode *root;
4028 	const char *descr;
4029 	int ret = -ENOMEM;
4030 	int blocksize, clustersize;
4031 	unsigned int db_count;
4032 	unsigned int i;
4033 	int needs_recovery, has_huge_files;
4034 	__u64 blocks_count;
4035 	int err = 0;
4036 	ext4_group_t first_not_zeroed;
4037 	struct ext4_parsed_options parsed_opts;
4038 
4039 	/* Set defaults for the variables that will be set during parsing */
4040 	parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4041 	parsed_opts.journal_devnum = 0;
4042 	parsed_opts.mb_optimize_scan = DEFAULT_MB_OPTIMIZE_SCAN;
4043 
4044 	if ((data && !orig_data) || !sbi)
4045 		goto out_free_base;
4046 
4047 	sbi->s_daxdev = dax_dev;
4048 	sbi->s_blockgroup_lock =
4049 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4050 	if (!sbi->s_blockgroup_lock)
4051 		goto out_free_base;
4052 
4053 	sb->s_fs_info = sbi;
4054 	sbi->s_sb = sb;
4055 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4056 	sbi->s_sb_block = sb_block;
4057 	sbi->s_sectors_written_start =
4058 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4059 
4060 	/* Cleanup superblock name */
4061 	strreplace(sb->s_id, '/', '!');
4062 
4063 	/* -EINVAL is default */
4064 	ret = -EINVAL;
4065 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4066 	if (!blocksize) {
4067 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4068 		goto out_fail;
4069 	}
4070 
4071 	/*
4072 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4073 	 * block sizes.  We need to calculate the offset from buffer start.
4074 	 */
4075 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4076 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4077 		offset = do_div(logical_sb_block, blocksize);
4078 	} else {
4079 		logical_sb_block = sb_block;
4080 	}
4081 
4082 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4083 	if (IS_ERR(bh)) {
4084 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4085 		ret = PTR_ERR(bh);
4086 		goto out_fail;
4087 	}
4088 	/*
4089 	 * Note: s_es must be initialized as soon as possible because
4090 	 *       some ext4 macro-instructions depend on its value
4091 	 */
4092 	es = (struct ext4_super_block *) (bh->b_data + offset);
4093 	sbi->s_es = es;
4094 	sb->s_magic = le16_to_cpu(es->s_magic);
4095 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4096 		goto cantfind_ext4;
4097 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4098 
4099 	/* Warn if metadata_csum and gdt_csum are both set. */
4100 	if (ext4_has_feature_metadata_csum(sb) &&
4101 	    ext4_has_feature_gdt_csum(sb))
4102 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4103 			     "redundant flags; please run fsck.");
4104 
4105 	/* Check for a known checksum algorithm */
4106 	if (!ext4_verify_csum_type(sb, es)) {
4107 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4108 			 "unknown checksum algorithm.");
4109 		silent = 1;
4110 		goto cantfind_ext4;
4111 	}
4112 
4113 	/* Load the checksum driver */
4114 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4115 	if (IS_ERR(sbi->s_chksum_driver)) {
4116 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4117 		ret = PTR_ERR(sbi->s_chksum_driver);
4118 		sbi->s_chksum_driver = NULL;
4119 		goto failed_mount;
4120 	}
4121 
4122 	/* Check superblock checksum */
4123 	if (!ext4_superblock_csum_verify(sb, es)) {
4124 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4125 			 "invalid superblock checksum.  Run e2fsck?");
4126 		silent = 1;
4127 		ret = -EFSBADCRC;
4128 		goto cantfind_ext4;
4129 	}
4130 
4131 	/* Precompute checksum seed for all metadata */
4132 	if (ext4_has_feature_csum_seed(sb))
4133 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4134 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4135 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4136 					       sizeof(es->s_uuid));
4137 
4138 	/* Set defaults before we parse the mount options */
4139 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4140 	set_opt(sb, INIT_INODE_TABLE);
4141 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4142 		set_opt(sb, DEBUG);
4143 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4144 		set_opt(sb, GRPID);
4145 	if (def_mount_opts & EXT4_DEFM_UID16)
4146 		set_opt(sb, NO_UID32);
4147 	/* xattr user namespace & acls are now defaulted on */
4148 	set_opt(sb, XATTR_USER);
4149 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4150 	set_opt(sb, POSIX_ACL);
4151 #endif
4152 	if (ext4_has_feature_fast_commit(sb))
4153 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4154 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4155 	if (ext4_has_metadata_csum(sb))
4156 		set_opt(sb, JOURNAL_CHECKSUM);
4157 
4158 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4159 		set_opt(sb, JOURNAL_DATA);
4160 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4161 		set_opt(sb, ORDERED_DATA);
4162 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4163 		set_opt(sb, WRITEBACK_DATA);
4164 
4165 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4166 		set_opt(sb, ERRORS_PANIC);
4167 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4168 		set_opt(sb, ERRORS_CONT);
4169 	else
4170 		set_opt(sb, ERRORS_RO);
4171 	/* block_validity enabled by default; disable with noblock_validity */
4172 	set_opt(sb, BLOCK_VALIDITY);
4173 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4174 		set_opt(sb, DISCARD);
4175 
4176 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4177 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4178 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4179 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4180 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4181 
4182 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4183 		set_opt(sb, BARRIER);
4184 
4185 	/*
4186 	 * enable delayed allocation by default
4187 	 * Use -o nodelalloc to turn it off
4188 	 */
4189 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4190 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4191 		set_opt(sb, DELALLOC);
4192 
4193 	/*
4194 	 * set default s_li_wait_mult for lazyinit, for the case there is
4195 	 * no mount option specified.
4196 	 */
4197 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4198 
4199 	if (le32_to_cpu(es->s_log_block_size) >
4200 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4201 		ext4_msg(sb, KERN_ERR,
4202 			 "Invalid log block size: %u",
4203 			 le32_to_cpu(es->s_log_block_size));
4204 		goto failed_mount;
4205 	}
4206 	if (le32_to_cpu(es->s_log_cluster_size) >
4207 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4208 		ext4_msg(sb, KERN_ERR,
4209 			 "Invalid log cluster size: %u",
4210 			 le32_to_cpu(es->s_log_cluster_size));
4211 		goto failed_mount;
4212 	}
4213 
4214 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4215 
4216 	if (blocksize == PAGE_SIZE)
4217 		set_opt(sb, DIOREAD_NOLOCK);
4218 
4219 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4220 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4221 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4222 	} else {
4223 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4224 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4225 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4226 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4227 				 sbi->s_first_ino);
4228 			goto failed_mount;
4229 		}
4230 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4231 		    (!is_power_of_2(sbi->s_inode_size)) ||
4232 		    (sbi->s_inode_size > blocksize)) {
4233 			ext4_msg(sb, KERN_ERR,
4234 			       "unsupported inode size: %d",
4235 			       sbi->s_inode_size);
4236 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4237 			goto failed_mount;
4238 		}
4239 		/*
4240 		 * i_atime_extra is the last extra field available for
4241 		 * [acm]times in struct ext4_inode. Checking for that
4242 		 * field should suffice to ensure we have extra space
4243 		 * for all three.
4244 		 */
4245 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4246 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4247 			sb->s_time_gran = 1;
4248 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4249 		} else {
4250 			sb->s_time_gran = NSEC_PER_SEC;
4251 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4252 		}
4253 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4254 	}
4255 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4256 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4257 			EXT4_GOOD_OLD_INODE_SIZE;
4258 		if (ext4_has_feature_extra_isize(sb)) {
4259 			unsigned v, max = (sbi->s_inode_size -
4260 					   EXT4_GOOD_OLD_INODE_SIZE);
4261 
4262 			v = le16_to_cpu(es->s_want_extra_isize);
4263 			if (v > max) {
4264 				ext4_msg(sb, KERN_ERR,
4265 					 "bad s_want_extra_isize: %d", v);
4266 				goto failed_mount;
4267 			}
4268 			if (sbi->s_want_extra_isize < v)
4269 				sbi->s_want_extra_isize = v;
4270 
4271 			v = le16_to_cpu(es->s_min_extra_isize);
4272 			if (v > max) {
4273 				ext4_msg(sb, KERN_ERR,
4274 					 "bad s_min_extra_isize: %d", v);
4275 				goto failed_mount;
4276 			}
4277 			if (sbi->s_want_extra_isize < v)
4278 				sbi->s_want_extra_isize = v;
4279 		}
4280 	}
4281 
4282 	if (sbi->s_es->s_mount_opts[0]) {
4283 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4284 					      sizeof(sbi->s_es->s_mount_opts),
4285 					      GFP_KERNEL);
4286 		if (!s_mount_opts)
4287 			goto failed_mount;
4288 		if (!parse_options(s_mount_opts, sb, &parsed_opts, 0)) {
4289 			ext4_msg(sb, KERN_WARNING,
4290 				 "failed to parse options in superblock: %s",
4291 				 s_mount_opts);
4292 		}
4293 		kfree(s_mount_opts);
4294 	}
4295 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4296 	if (!parse_options((char *) data, sb, &parsed_opts, 0))
4297 		goto failed_mount;
4298 
4299 #ifdef CONFIG_UNICODE
4300 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4301 		const struct ext4_sb_encodings *encoding_info;
4302 		struct unicode_map *encoding;
4303 		__u16 encoding_flags;
4304 
4305 		if (ext4_sb_read_encoding(es, &encoding_info,
4306 					  &encoding_flags)) {
4307 			ext4_msg(sb, KERN_ERR,
4308 				 "Encoding requested by superblock is unknown");
4309 			goto failed_mount;
4310 		}
4311 
4312 		encoding = utf8_load(encoding_info->version);
4313 		if (IS_ERR(encoding)) {
4314 			ext4_msg(sb, KERN_ERR,
4315 				 "can't mount with superblock charset: %s-%s "
4316 				 "not supported by the kernel. flags: 0x%x.",
4317 				 encoding_info->name, encoding_info->version,
4318 				 encoding_flags);
4319 			goto failed_mount;
4320 		}
4321 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4322 			 "%s-%s with flags 0x%hx", encoding_info->name,
4323 			 encoding_info->version?:"\b", encoding_flags);
4324 
4325 		sb->s_encoding = encoding;
4326 		sb->s_encoding_flags = encoding_flags;
4327 	}
4328 #endif
4329 
4330 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4331 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4332 		/* can't mount with both data=journal and dioread_nolock. */
4333 		clear_opt(sb, DIOREAD_NOLOCK);
4334 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4335 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4336 			ext4_msg(sb, KERN_ERR, "can't mount with "
4337 				 "both data=journal and delalloc");
4338 			goto failed_mount;
4339 		}
4340 		if (test_opt(sb, DAX_ALWAYS)) {
4341 			ext4_msg(sb, KERN_ERR, "can't mount with "
4342 				 "both data=journal and dax");
4343 			goto failed_mount;
4344 		}
4345 		if (ext4_has_feature_encrypt(sb)) {
4346 			ext4_msg(sb, KERN_WARNING,
4347 				 "encrypted files will use data=ordered "
4348 				 "instead of data journaling mode");
4349 		}
4350 		if (test_opt(sb, DELALLOC))
4351 			clear_opt(sb, DELALLOC);
4352 	} else {
4353 		sb->s_iflags |= SB_I_CGROUPWB;
4354 	}
4355 
4356 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4357 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4358 
4359 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4360 	    (ext4_has_compat_features(sb) ||
4361 	     ext4_has_ro_compat_features(sb) ||
4362 	     ext4_has_incompat_features(sb)))
4363 		ext4_msg(sb, KERN_WARNING,
4364 		       "feature flags set on rev 0 fs, "
4365 		       "running e2fsck is recommended");
4366 
4367 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4368 		set_opt2(sb, HURD_COMPAT);
4369 		if (ext4_has_feature_64bit(sb)) {
4370 			ext4_msg(sb, KERN_ERR,
4371 				 "The Hurd can't support 64-bit file systems");
4372 			goto failed_mount;
4373 		}
4374 
4375 		/*
4376 		 * ea_inode feature uses l_i_version field which is not
4377 		 * available in HURD_COMPAT mode.
4378 		 */
4379 		if (ext4_has_feature_ea_inode(sb)) {
4380 			ext4_msg(sb, KERN_ERR,
4381 				 "ea_inode feature is not supported for Hurd");
4382 			goto failed_mount;
4383 		}
4384 	}
4385 
4386 	if (IS_EXT2_SB(sb)) {
4387 		if (ext2_feature_set_ok(sb))
4388 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4389 				 "using the ext4 subsystem");
4390 		else {
4391 			/*
4392 			 * If we're probing be silent, if this looks like
4393 			 * it's actually an ext[34] filesystem.
4394 			 */
4395 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4396 				goto failed_mount;
4397 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4398 				 "to feature incompatibilities");
4399 			goto failed_mount;
4400 		}
4401 	}
4402 
4403 	if (IS_EXT3_SB(sb)) {
4404 		if (ext3_feature_set_ok(sb))
4405 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4406 				 "using the ext4 subsystem");
4407 		else {
4408 			/*
4409 			 * If we're probing be silent, if this looks like
4410 			 * it's actually an ext4 filesystem.
4411 			 */
4412 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4413 				goto failed_mount;
4414 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4415 				 "to feature incompatibilities");
4416 			goto failed_mount;
4417 		}
4418 	}
4419 
4420 	/*
4421 	 * Check feature flags regardless of the revision level, since we
4422 	 * previously didn't change the revision level when setting the flags,
4423 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4424 	 */
4425 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4426 		goto failed_mount;
4427 
4428 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4429 		ext4_msg(sb, KERN_ERR,
4430 			 "Number of reserved GDT blocks insanely large: %d",
4431 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4432 		goto failed_mount;
4433 	}
4434 
4435 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4436 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4437 
4438 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4439 		if (ext4_has_feature_inline_data(sb)) {
4440 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4441 					" that may contain inline data");
4442 			goto failed_mount;
4443 		}
4444 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4445 			ext4_msg(sb, KERN_ERR,
4446 				"DAX unsupported by block device.");
4447 			goto failed_mount;
4448 		}
4449 	}
4450 
4451 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4452 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4453 			 es->s_encryption_level);
4454 		goto failed_mount;
4455 	}
4456 
4457 	if (sb->s_blocksize != blocksize) {
4458 		/*
4459 		 * bh must be released before kill_bdev(), otherwise
4460 		 * it won't be freed and its page also. kill_bdev()
4461 		 * is called by sb_set_blocksize().
4462 		 */
4463 		brelse(bh);
4464 		/* Validate the filesystem blocksize */
4465 		if (!sb_set_blocksize(sb, blocksize)) {
4466 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4467 					blocksize);
4468 			bh = NULL;
4469 			goto failed_mount;
4470 		}
4471 
4472 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4473 		offset = do_div(logical_sb_block, blocksize);
4474 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4475 		if (IS_ERR(bh)) {
4476 			ext4_msg(sb, KERN_ERR,
4477 			       "Can't read superblock on 2nd try");
4478 			ret = PTR_ERR(bh);
4479 			bh = NULL;
4480 			goto failed_mount;
4481 		}
4482 		es = (struct ext4_super_block *)(bh->b_data + offset);
4483 		sbi->s_es = es;
4484 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4485 			ext4_msg(sb, KERN_ERR,
4486 			       "Magic mismatch, very weird!");
4487 			goto failed_mount;
4488 		}
4489 	}
4490 
4491 	has_huge_files = ext4_has_feature_huge_file(sb);
4492 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4493 						      has_huge_files);
4494 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4495 
4496 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4497 	if (ext4_has_feature_64bit(sb)) {
4498 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4499 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4500 		    !is_power_of_2(sbi->s_desc_size)) {
4501 			ext4_msg(sb, KERN_ERR,
4502 			       "unsupported descriptor size %lu",
4503 			       sbi->s_desc_size);
4504 			goto failed_mount;
4505 		}
4506 	} else
4507 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4508 
4509 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4510 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4511 
4512 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4513 	if (sbi->s_inodes_per_block == 0)
4514 		goto cantfind_ext4;
4515 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4516 	    sbi->s_inodes_per_group > blocksize * 8) {
4517 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4518 			 sbi->s_inodes_per_group);
4519 		goto failed_mount;
4520 	}
4521 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4522 					sbi->s_inodes_per_block;
4523 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4524 	sbi->s_sbh = bh;
4525 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4526 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4527 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4528 
4529 	for (i = 0; i < 4; i++)
4530 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4531 	sbi->s_def_hash_version = es->s_def_hash_version;
4532 	if (ext4_has_feature_dir_index(sb)) {
4533 		i = le32_to_cpu(es->s_flags);
4534 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4535 			sbi->s_hash_unsigned = 3;
4536 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4537 #ifdef __CHAR_UNSIGNED__
4538 			if (!sb_rdonly(sb))
4539 				es->s_flags |=
4540 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4541 			sbi->s_hash_unsigned = 3;
4542 #else
4543 			if (!sb_rdonly(sb))
4544 				es->s_flags |=
4545 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4546 #endif
4547 		}
4548 	}
4549 
4550 	/* Handle clustersize */
4551 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4552 	if (ext4_has_feature_bigalloc(sb)) {
4553 		if (clustersize < blocksize) {
4554 			ext4_msg(sb, KERN_ERR,
4555 				 "cluster size (%d) smaller than "
4556 				 "block size (%d)", clustersize, blocksize);
4557 			goto failed_mount;
4558 		}
4559 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4560 			le32_to_cpu(es->s_log_block_size);
4561 		sbi->s_clusters_per_group =
4562 			le32_to_cpu(es->s_clusters_per_group);
4563 		if (sbi->s_clusters_per_group > blocksize * 8) {
4564 			ext4_msg(sb, KERN_ERR,
4565 				 "#clusters per group too big: %lu",
4566 				 sbi->s_clusters_per_group);
4567 			goto failed_mount;
4568 		}
4569 		if (sbi->s_blocks_per_group !=
4570 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4571 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4572 				 "clusters per group (%lu) inconsistent",
4573 				 sbi->s_blocks_per_group,
4574 				 sbi->s_clusters_per_group);
4575 			goto failed_mount;
4576 		}
4577 	} else {
4578 		if (clustersize != blocksize) {
4579 			ext4_msg(sb, KERN_ERR,
4580 				 "fragment/cluster size (%d) != "
4581 				 "block size (%d)", clustersize, blocksize);
4582 			goto failed_mount;
4583 		}
4584 		if (sbi->s_blocks_per_group > blocksize * 8) {
4585 			ext4_msg(sb, KERN_ERR,
4586 				 "#blocks per group too big: %lu",
4587 				 sbi->s_blocks_per_group);
4588 			goto failed_mount;
4589 		}
4590 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4591 		sbi->s_cluster_bits = 0;
4592 	}
4593 	sbi->s_cluster_ratio = clustersize / blocksize;
4594 
4595 	/* Do we have standard group size of clustersize * 8 blocks ? */
4596 	if (sbi->s_blocks_per_group == clustersize << 3)
4597 		set_opt2(sb, STD_GROUP_SIZE);
4598 
4599 	/*
4600 	 * Test whether we have more sectors than will fit in sector_t,
4601 	 * and whether the max offset is addressable by the page cache.
4602 	 */
4603 	err = generic_check_addressable(sb->s_blocksize_bits,
4604 					ext4_blocks_count(es));
4605 	if (err) {
4606 		ext4_msg(sb, KERN_ERR, "filesystem"
4607 			 " too large to mount safely on this system");
4608 		goto failed_mount;
4609 	}
4610 
4611 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4612 		goto cantfind_ext4;
4613 
4614 	/* check blocks count against device size */
4615 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4616 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4617 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4618 		       "exceeds size of device (%llu blocks)",
4619 		       ext4_blocks_count(es), blocks_count);
4620 		goto failed_mount;
4621 	}
4622 
4623 	/*
4624 	 * It makes no sense for the first data block to be beyond the end
4625 	 * of the filesystem.
4626 	 */
4627 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4628 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4629 			 "block %u is beyond end of filesystem (%llu)",
4630 			 le32_to_cpu(es->s_first_data_block),
4631 			 ext4_blocks_count(es));
4632 		goto failed_mount;
4633 	}
4634 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4635 	    (sbi->s_cluster_ratio == 1)) {
4636 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4637 			 "block is 0 with a 1k block and cluster size");
4638 		goto failed_mount;
4639 	}
4640 
4641 	blocks_count = (ext4_blocks_count(es) -
4642 			le32_to_cpu(es->s_first_data_block) +
4643 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4644 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4645 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4646 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4647 		       "(block count %llu, first data block %u, "
4648 		       "blocks per group %lu)", blocks_count,
4649 		       ext4_blocks_count(es),
4650 		       le32_to_cpu(es->s_first_data_block),
4651 		       EXT4_BLOCKS_PER_GROUP(sb));
4652 		goto failed_mount;
4653 	}
4654 	sbi->s_groups_count = blocks_count;
4655 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4656 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4657 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4658 	    le32_to_cpu(es->s_inodes_count)) {
4659 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4660 			 le32_to_cpu(es->s_inodes_count),
4661 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4662 		ret = -EINVAL;
4663 		goto failed_mount;
4664 	}
4665 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4666 		   EXT4_DESC_PER_BLOCK(sb);
4667 	if (ext4_has_feature_meta_bg(sb)) {
4668 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4669 			ext4_msg(sb, KERN_WARNING,
4670 				 "first meta block group too large: %u "
4671 				 "(group descriptor block count %u)",
4672 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4673 			goto failed_mount;
4674 		}
4675 	}
4676 	rcu_assign_pointer(sbi->s_group_desc,
4677 			   kvmalloc_array(db_count,
4678 					  sizeof(struct buffer_head *),
4679 					  GFP_KERNEL));
4680 	if (sbi->s_group_desc == NULL) {
4681 		ext4_msg(sb, KERN_ERR, "not enough memory");
4682 		ret = -ENOMEM;
4683 		goto failed_mount;
4684 	}
4685 
4686 	bgl_lock_init(sbi->s_blockgroup_lock);
4687 
4688 	/* Pre-read the descriptors into the buffer cache */
4689 	for (i = 0; i < db_count; i++) {
4690 		block = descriptor_loc(sb, logical_sb_block, i);
4691 		ext4_sb_breadahead_unmovable(sb, block);
4692 	}
4693 
4694 	for (i = 0; i < db_count; i++) {
4695 		struct buffer_head *bh;
4696 
4697 		block = descriptor_loc(sb, logical_sb_block, i);
4698 		bh = ext4_sb_bread_unmovable(sb, block);
4699 		if (IS_ERR(bh)) {
4700 			ext4_msg(sb, KERN_ERR,
4701 			       "can't read group descriptor %d", i);
4702 			db_count = i;
4703 			ret = PTR_ERR(bh);
4704 			goto failed_mount2;
4705 		}
4706 		rcu_read_lock();
4707 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4708 		rcu_read_unlock();
4709 	}
4710 	sbi->s_gdb_count = db_count;
4711 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4712 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4713 		ret = -EFSCORRUPTED;
4714 		goto failed_mount2;
4715 	}
4716 
4717 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4718 	spin_lock_init(&sbi->s_error_lock);
4719 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
4720 
4721 	/* Register extent status tree shrinker */
4722 	if (ext4_es_register_shrinker(sbi))
4723 		goto failed_mount3;
4724 
4725 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4726 	sbi->s_extent_max_zeroout_kb = 32;
4727 
4728 	/*
4729 	 * set up enough so that it can read an inode
4730 	 */
4731 	sb->s_op = &ext4_sops;
4732 	sb->s_export_op = &ext4_export_ops;
4733 	sb->s_xattr = ext4_xattr_handlers;
4734 #ifdef CONFIG_FS_ENCRYPTION
4735 	sb->s_cop = &ext4_cryptops;
4736 #endif
4737 #ifdef CONFIG_FS_VERITY
4738 	sb->s_vop = &ext4_verityops;
4739 #endif
4740 #ifdef CONFIG_QUOTA
4741 	sb->dq_op = &ext4_quota_operations;
4742 	if (ext4_has_feature_quota(sb))
4743 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4744 	else
4745 		sb->s_qcop = &ext4_qctl_operations;
4746 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4747 #endif
4748 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4749 
4750 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4751 	mutex_init(&sbi->s_orphan_lock);
4752 
4753 	/* Initialize fast commit stuff */
4754 	atomic_set(&sbi->s_fc_subtid, 0);
4755 	atomic_set(&sbi->s_fc_ineligible_updates, 0);
4756 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4757 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4758 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4759 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4760 	sbi->s_fc_bytes = 0;
4761 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4762 	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
4763 	spin_lock_init(&sbi->s_fc_lock);
4764 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4765 	sbi->s_fc_replay_state.fc_regions = NULL;
4766 	sbi->s_fc_replay_state.fc_regions_size = 0;
4767 	sbi->s_fc_replay_state.fc_regions_used = 0;
4768 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4769 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4770 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4771 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4772 
4773 	sb->s_root = NULL;
4774 
4775 	needs_recovery = (es->s_last_orphan != 0 ||
4776 			  ext4_has_feature_journal_needs_recovery(sb));
4777 
4778 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4779 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4780 			goto failed_mount3a;
4781 
4782 	/*
4783 	 * The first inode we look at is the journal inode.  Don't try
4784 	 * root first: it may be modified in the journal!
4785 	 */
4786 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4787 		err = ext4_load_journal(sb, es, parsed_opts.journal_devnum);
4788 		if (err)
4789 			goto failed_mount3a;
4790 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4791 		   ext4_has_feature_journal_needs_recovery(sb)) {
4792 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4793 		       "suppressed and not mounted read-only");
4794 		goto failed_mount_wq;
4795 	} else {
4796 		/* Nojournal mode, all journal mount options are illegal */
4797 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4798 			ext4_msg(sb, KERN_ERR, "can't mount with "
4799 				 "journal_checksum, fs mounted w/o journal");
4800 			goto failed_mount_wq;
4801 		}
4802 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4803 			ext4_msg(sb, KERN_ERR, "can't mount with "
4804 				 "journal_async_commit, fs mounted w/o journal");
4805 			goto failed_mount_wq;
4806 		}
4807 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4808 			ext4_msg(sb, KERN_ERR, "can't mount with "
4809 				 "commit=%lu, fs mounted w/o journal",
4810 				 sbi->s_commit_interval / HZ);
4811 			goto failed_mount_wq;
4812 		}
4813 		if (EXT4_MOUNT_DATA_FLAGS &
4814 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4815 			ext4_msg(sb, KERN_ERR, "can't mount with "
4816 				 "data=, fs mounted w/o journal");
4817 			goto failed_mount_wq;
4818 		}
4819 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4820 		clear_opt(sb, JOURNAL_CHECKSUM);
4821 		clear_opt(sb, DATA_FLAGS);
4822 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4823 		sbi->s_journal = NULL;
4824 		needs_recovery = 0;
4825 		goto no_journal;
4826 	}
4827 
4828 	if (ext4_has_feature_64bit(sb) &&
4829 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4830 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4831 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4832 		goto failed_mount_wq;
4833 	}
4834 
4835 	if (!set_journal_csum_feature_set(sb)) {
4836 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4837 			 "feature set");
4838 		goto failed_mount_wq;
4839 	}
4840 
4841 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4842 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4843 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4844 		ext4_msg(sb, KERN_ERR,
4845 			"Failed to set fast commit journal feature");
4846 		goto failed_mount_wq;
4847 	}
4848 
4849 	/* We have now updated the journal if required, so we can
4850 	 * validate the data journaling mode. */
4851 	switch (test_opt(sb, DATA_FLAGS)) {
4852 	case 0:
4853 		/* No mode set, assume a default based on the journal
4854 		 * capabilities: ORDERED_DATA if the journal can
4855 		 * cope, else JOURNAL_DATA
4856 		 */
4857 		if (jbd2_journal_check_available_features
4858 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4859 			set_opt(sb, ORDERED_DATA);
4860 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4861 		} else {
4862 			set_opt(sb, JOURNAL_DATA);
4863 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4864 		}
4865 		break;
4866 
4867 	case EXT4_MOUNT_ORDERED_DATA:
4868 	case EXT4_MOUNT_WRITEBACK_DATA:
4869 		if (!jbd2_journal_check_available_features
4870 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4871 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4872 			       "requested data journaling mode");
4873 			goto failed_mount_wq;
4874 		}
4875 		break;
4876 	default:
4877 		break;
4878 	}
4879 
4880 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4881 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4882 		ext4_msg(sb, KERN_ERR, "can't mount with "
4883 			"journal_async_commit in data=ordered mode");
4884 		goto failed_mount_wq;
4885 	}
4886 
4887 	set_task_ioprio(sbi->s_journal->j_task, parsed_opts.journal_ioprio);
4888 
4889 	sbi->s_journal->j_submit_inode_data_buffers =
4890 		ext4_journal_submit_inode_data_buffers;
4891 	sbi->s_journal->j_finish_inode_data_buffers =
4892 		ext4_journal_finish_inode_data_buffers;
4893 
4894 no_journal:
4895 	if (!test_opt(sb, NO_MBCACHE)) {
4896 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4897 		if (!sbi->s_ea_block_cache) {
4898 			ext4_msg(sb, KERN_ERR,
4899 				 "Failed to create ea_block_cache");
4900 			goto failed_mount_wq;
4901 		}
4902 
4903 		if (ext4_has_feature_ea_inode(sb)) {
4904 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4905 			if (!sbi->s_ea_inode_cache) {
4906 				ext4_msg(sb, KERN_ERR,
4907 					 "Failed to create ea_inode_cache");
4908 				goto failed_mount_wq;
4909 			}
4910 		}
4911 	}
4912 
4913 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4914 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4915 		goto failed_mount_wq;
4916 	}
4917 
4918 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4919 	    !ext4_has_feature_encrypt(sb)) {
4920 		ext4_set_feature_encrypt(sb);
4921 		ext4_commit_super(sb);
4922 	}
4923 
4924 	/*
4925 	 * Get the # of file system overhead blocks from the
4926 	 * superblock if present.
4927 	 */
4928 	if (es->s_overhead_clusters)
4929 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4930 	else {
4931 		err = ext4_calculate_overhead(sb);
4932 		if (err)
4933 			goto failed_mount_wq;
4934 	}
4935 
4936 	/*
4937 	 * The maximum number of concurrent works can be high and
4938 	 * concurrency isn't really necessary.  Limit it to 1.
4939 	 */
4940 	EXT4_SB(sb)->rsv_conversion_wq =
4941 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4942 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4943 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4944 		ret = -ENOMEM;
4945 		goto failed_mount4;
4946 	}
4947 
4948 	/*
4949 	 * The jbd2_journal_load will have done any necessary log recovery,
4950 	 * so we can safely mount the rest of the filesystem now.
4951 	 */
4952 
4953 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4954 	if (IS_ERR(root)) {
4955 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4956 		ret = PTR_ERR(root);
4957 		root = NULL;
4958 		goto failed_mount4;
4959 	}
4960 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4961 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4962 		iput(root);
4963 		goto failed_mount4;
4964 	}
4965 
4966 	sb->s_root = d_make_root(root);
4967 	if (!sb->s_root) {
4968 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4969 		ret = -ENOMEM;
4970 		goto failed_mount4;
4971 	}
4972 
4973 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4974 	if (ret == -EROFS) {
4975 		sb->s_flags |= SB_RDONLY;
4976 		ret = 0;
4977 	} else if (ret)
4978 		goto failed_mount4a;
4979 
4980 	ext4_set_resv_clusters(sb);
4981 
4982 	if (test_opt(sb, BLOCK_VALIDITY)) {
4983 		err = ext4_setup_system_zone(sb);
4984 		if (err) {
4985 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
4986 				 "zone (%d)", err);
4987 			goto failed_mount4a;
4988 		}
4989 	}
4990 	ext4_fc_replay_cleanup(sb);
4991 
4992 	ext4_ext_init(sb);
4993 
4994 	/*
4995 	 * Enable optimize_scan if number of groups is > threshold. This can be
4996 	 * turned off by passing "mb_optimize_scan=0". This can also be
4997 	 * turned on forcefully by passing "mb_optimize_scan=1".
4998 	 */
4999 	if (parsed_opts.mb_optimize_scan == 1)
5000 		set_opt2(sb, MB_OPTIMIZE_SCAN);
5001 	else if (parsed_opts.mb_optimize_scan == 0)
5002 		clear_opt2(sb, MB_OPTIMIZE_SCAN);
5003 	else if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5004 		set_opt2(sb, MB_OPTIMIZE_SCAN);
5005 
5006 	err = ext4_mb_init(sb);
5007 	if (err) {
5008 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5009 			 err);
5010 		goto failed_mount5;
5011 	}
5012 
5013 	/*
5014 	 * We can only set up the journal commit callback once
5015 	 * mballoc is initialized
5016 	 */
5017 	if (sbi->s_journal)
5018 		sbi->s_journal->j_commit_callback =
5019 			ext4_journal_commit_callback;
5020 
5021 	block = ext4_count_free_clusters(sb);
5022 	ext4_free_blocks_count_set(sbi->s_es,
5023 				   EXT4_C2B(sbi, block));
5024 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5025 				  GFP_KERNEL);
5026 	if (!err) {
5027 		unsigned long freei = ext4_count_free_inodes(sb);
5028 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5029 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5030 					  GFP_KERNEL);
5031 	}
5032 	if (!err)
5033 		err = percpu_counter_init(&sbi->s_dirs_counter,
5034 					  ext4_count_dirs(sb), GFP_KERNEL);
5035 	if (!err)
5036 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5037 					  GFP_KERNEL);
5038 	if (!err)
5039 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5040 					  GFP_KERNEL);
5041 	if (!err)
5042 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5043 
5044 	if (err) {
5045 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5046 		goto failed_mount6;
5047 	}
5048 
5049 	if (ext4_has_feature_flex_bg(sb))
5050 		if (!ext4_fill_flex_info(sb)) {
5051 			ext4_msg(sb, KERN_ERR,
5052 			       "unable to initialize "
5053 			       "flex_bg meta info!");
5054 			ret = -ENOMEM;
5055 			goto failed_mount6;
5056 		}
5057 
5058 	err = ext4_register_li_request(sb, first_not_zeroed);
5059 	if (err)
5060 		goto failed_mount6;
5061 
5062 	err = ext4_register_sysfs(sb);
5063 	if (err)
5064 		goto failed_mount7;
5065 
5066 #ifdef CONFIG_QUOTA
5067 	/* Enable quota usage during mount. */
5068 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5069 		err = ext4_enable_quotas(sb);
5070 		if (err)
5071 			goto failed_mount8;
5072 	}
5073 #endif  /* CONFIG_QUOTA */
5074 
5075 	/*
5076 	 * Save the original bdev mapping's wb_err value which could be
5077 	 * used to detect the metadata async write error.
5078 	 */
5079 	spin_lock_init(&sbi->s_bdev_wb_lock);
5080 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5081 				 &sbi->s_bdev_wb_err);
5082 	sb->s_bdev->bd_super = sb;
5083 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5084 	ext4_orphan_cleanup(sb, es);
5085 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5086 	if (needs_recovery) {
5087 		ext4_msg(sb, KERN_INFO, "recovery complete");
5088 		err = ext4_mark_recovery_complete(sb, es);
5089 		if (err)
5090 			goto failed_mount8;
5091 	}
5092 	if (EXT4_SB(sb)->s_journal) {
5093 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5094 			descr = " journalled data mode";
5095 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5096 			descr = " ordered data mode";
5097 		else
5098 			descr = " writeback data mode";
5099 	} else
5100 		descr = "out journal";
5101 
5102 	if (test_opt(sb, DISCARD)) {
5103 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5104 		if (!blk_queue_discard(q))
5105 			ext4_msg(sb, KERN_WARNING,
5106 				 "mounting with \"discard\" option, but "
5107 				 "the device does not support discard");
5108 	}
5109 
5110 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5111 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5112 			 "Opts: %.*s%s%s. Quota mode: %s.", descr,
5113 			 (int) sizeof(sbi->s_es->s_mount_opts),
5114 			 sbi->s_es->s_mount_opts,
5115 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data,
5116 			 ext4_quota_mode(sb));
5117 
5118 	if (es->s_error_count)
5119 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5120 
5121 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5122 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5123 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5124 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5125 	atomic_set(&sbi->s_warning_count, 0);
5126 	atomic_set(&sbi->s_msg_count, 0);
5127 
5128 	kfree(orig_data);
5129 	return 0;
5130 
5131 cantfind_ext4:
5132 	if (!silent)
5133 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5134 	goto failed_mount;
5135 
5136 failed_mount8:
5137 	ext4_unregister_sysfs(sb);
5138 	kobject_put(&sbi->s_kobj);
5139 failed_mount7:
5140 	ext4_unregister_li_request(sb);
5141 failed_mount6:
5142 	ext4_mb_release(sb);
5143 	rcu_read_lock();
5144 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5145 	if (flex_groups) {
5146 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5147 			kvfree(flex_groups[i]);
5148 		kvfree(flex_groups);
5149 	}
5150 	rcu_read_unlock();
5151 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5152 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5153 	percpu_counter_destroy(&sbi->s_dirs_counter);
5154 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5155 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5156 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5157 failed_mount5:
5158 	ext4_ext_release(sb);
5159 	ext4_release_system_zone(sb);
5160 failed_mount4a:
5161 	dput(sb->s_root);
5162 	sb->s_root = NULL;
5163 failed_mount4:
5164 	ext4_msg(sb, KERN_ERR, "mount failed");
5165 	if (EXT4_SB(sb)->rsv_conversion_wq)
5166 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5167 failed_mount_wq:
5168 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5169 	sbi->s_ea_inode_cache = NULL;
5170 
5171 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5172 	sbi->s_ea_block_cache = NULL;
5173 
5174 	if (sbi->s_journal) {
5175 		jbd2_journal_destroy(sbi->s_journal);
5176 		sbi->s_journal = NULL;
5177 	}
5178 failed_mount3a:
5179 	ext4_es_unregister_shrinker(sbi);
5180 failed_mount3:
5181 	flush_work(&sbi->s_error_work);
5182 	del_timer_sync(&sbi->s_err_report);
5183 	ext4_stop_mmpd(sbi);
5184 failed_mount2:
5185 	rcu_read_lock();
5186 	group_desc = rcu_dereference(sbi->s_group_desc);
5187 	for (i = 0; i < db_count; i++)
5188 		brelse(group_desc[i]);
5189 	kvfree(group_desc);
5190 	rcu_read_unlock();
5191 failed_mount:
5192 	if (sbi->s_chksum_driver)
5193 		crypto_free_shash(sbi->s_chksum_driver);
5194 
5195 #ifdef CONFIG_UNICODE
5196 	utf8_unload(sb->s_encoding);
5197 #endif
5198 
5199 #ifdef CONFIG_QUOTA
5200 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5201 		kfree(get_qf_name(sb, sbi, i));
5202 #endif
5203 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5204 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5205 	brelse(bh);
5206 	ext4_blkdev_remove(sbi);
5207 out_fail:
5208 	sb->s_fs_info = NULL;
5209 	kfree(sbi->s_blockgroup_lock);
5210 out_free_base:
5211 	kfree(sbi);
5212 	kfree(orig_data);
5213 	fs_put_dax(dax_dev);
5214 	return err ? err : ret;
5215 }
5216 
5217 /*
5218  * Setup any per-fs journal parameters now.  We'll do this both on
5219  * initial mount, once the journal has been initialised but before we've
5220  * done any recovery; and again on any subsequent remount.
5221  */
5222 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5223 {
5224 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5225 
5226 	journal->j_commit_interval = sbi->s_commit_interval;
5227 	journal->j_min_batch_time = sbi->s_min_batch_time;
5228 	journal->j_max_batch_time = sbi->s_max_batch_time;
5229 	ext4_fc_init(sb, journal);
5230 
5231 	write_lock(&journal->j_state_lock);
5232 	if (test_opt(sb, BARRIER))
5233 		journal->j_flags |= JBD2_BARRIER;
5234 	else
5235 		journal->j_flags &= ~JBD2_BARRIER;
5236 	if (test_opt(sb, DATA_ERR_ABORT))
5237 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5238 	else
5239 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5240 	write_unlock(&journal->j_state_lock);
5241 }
5242 
5243 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5244 					     unsigned int journal_inum)
5245 {
5246 	struct inode *journal_inode;
5247 
5248 	/*
5249 	 * Test for the existence of a valid inode on disk.  Bad things
5250 	 * happen if we iget() an unused inode, as the subsequent iput()
5251 	 * will try to delete it.
5252 	 */
5253 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5254 	if (IS_ERR(journal_inode)) {
5255 		ext4_msg(sb, KERN_ERR, "no journal found");
5256 		return NULL;
5257 	}
5258 	if (!journal_inode->i_nlink) {
5259 		make_bad_inode(journal_inode);
5260 		iput(journal_inode);
5261 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5262 		return NULL;
5263 	}
5264 
5265 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5266 		  journal_inode, journal_inode->i_size);
5267 	if (!S_ISREG(journal_inode->i_mode)) {
5268 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5269 		iput(journal_inode);
5270 		return NULL;
5271 	}
5272 	return journal_inode;
5273 }
5274 
5275 static journal_t *ext4_get_journal(struct super_block *sb,
5276 				   unsigned int journal_inum)
5277 {
5278 	struct inode *journal_inode;
5279 	journal_t *journal;
5280 
5281 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5282 		return NULL;
5283 
5284 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5285 	if (!journal_inode)
5286 		return NULL;
5287 
5288 	journal = jbd2_journal_init_inode(journal_inode);
5289 	if (!journal) {
5290 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5291 		iput(journal_inode);
5292 		return NULL;
5293 	}
5294 	journal->j_private = sb;
5295 	ext4_init_journal_params(sb, journal);
5296 	return journal;
5297 }
5298 
5299 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5300 				       dev_t j_dev)
5301 {
5302 	struct buffer_head *bh;
5303 	journal_t *journal;
5304 	ext4_fsblk_t start;
5305 	ext4_fsblk_t len;
5306 	int hblock, blocksize;
5307 	ext4_fsblk_t sb_block;
5308 	unsigned long offset;
5309 	struct ext4_super_block *es;
5310 	struct block_device *bdev;
5311 
5312 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5313 		return NULL;
5314 
5315 	bdev = ext4_blkdev_get(j_dev, sb);
5316 	if (bdev == NULL)
5317 		return NULL;
5318 
5319 	blocksize = sb->s_blocksize;
5320 	hblock = bdev_logical_block_size(bdev);
5321 	if (blocksize < hblock) {
5322 		ext4_msg(sb, KERN_ERR,
5323 			"blocksize too small for journal device");
5324 		goto out_bdev;
5325 	}
5326 
5327 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5328 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5329 	set_blocksize(bdev, blocksize);
5330 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5331 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5332 		       "external journal");
5333 		goto out_bdev;
5334 	}
5335 
5336 	es = (struct ext4_super_block *) (bh->b_data + offset);
5337 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5338 	    !(le32_to_cpu(es->s_feature_incompat) &
5339 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5340 		ext4_msg(sb, KERN_ERR, "external journal has "
5341 					"bad superblock");
5342 		brelse(bh);
5343 		goto out_bdev;
5344 	}
5345 
5346 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5347 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5348 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5349 		ext4_msg(sb, KERN_ERR, "external journal has "
5350 				       "corrupt superblock");
5351 		brelse(bh);
5352 		goto out_bdev;
5353 	}
5354 
5355 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5356 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5357 		brelse(bh);
5358 		goto out_bdev;
5359 	}
5360 
5361 	len = ext4_blocks_count(es);
5362 	start = sb_block + 1;
5363 	brelse(bh);	/* we're done with the superblock */
5364 
5365 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5366 					start, len, blocksize);
5367 	if (!journal) {
5368 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5369 		goto out_bdev;
5370 	}
5371 	journal->j_private = sb;
5372 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5373 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5374 		goto out_journal;
5375 	}
5376 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5377 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5378 					"user (unsupported) - %d",
5379 			be32_to_cpu(journal->j_superblock->s_nr_users));
5380 		goto out_journal;
5381 	}
5382 	EXT4_SB(sb)->s_journal_bdev = bdev;
5383 	ext4_init_journal_params(sb, journal);
5384 	return journal;
5385 
5386 out_journal:
5387 	jbd2_journal_destroy(journal);
5388 out_bdev:
5389 	ext4_blkdev_put(bdev);
5390 	return NULL;
5391 }
5392 
5393 static int ext4_load_journal(struct super_block *sb,
5394 			     struct ext4_super_block *es,
5395 			     unsigned long journal_devnum)
5396 {
5397 	journal_t *journal;
5398 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5399 	dev_t journal_dev;
5400 	int err = 0;
5401 	int really_read_only;
5402 	int journal_dev_ro;
5403 
5404 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5405 		return -EFSCORRUPTED;
5406 
5407 	if (journal_devnum &&
5408 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5409 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5410 			"numbers have changed");
5411 		journal_dev = new_decode_dev(journal_devnum);
5412 	} else
5413 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5414 
5415 	if (journal_inum && journal_dev) {
5416 		ext4_msg(sb, KERN_ERR,
5417 			 "filesystem has both journal inode and journal device!");
5418 		return -EINVAL;
5419 	}
5420 
5421 	if (journal_inum) {
5422 		journal = ext4_get_journal(sb, journal_inum);
5423 		if (!journal)
5424 			return -EINVAL;
5425 	} else {
5426 		journal = ext4_get_dev_journal(sb, journal_dev);
5427 		if (!journal)
5428 			return -EINVAL;
5429 	}
5430 
5431 	journal_dev_ro = bdev_read_only(journal->j_dev);
5432 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5433 
5434 	if (journal_dev_ro && !sb_rdonly(sb)) {
5435 		ext4_msg(sb, KERN_ERR,
5436 			 "journal device read-only, try mounting with '-o ro'");
5437 		err = -EROFS;
5438 		goto err_out;
5439 	}
5440 
5441 	/*
5442 	 * Are we loading a blank journal or performing recovery after a
5443 	 * crash?  For recovery, we need to check in advance whether we
5444 	 * can get read-write access to the device.
5445 	 */
5446 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5447 		if (sb_rdonly(sb)) {
5448 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5449 					"required on readonly filesystem");
5450 			if (really_read_only) {
5451 				ext4_msg(sb, KERN_ERR, "write access "
5452 					"unavailable, cannot proceed "
5453 					"(try mounting with noload)");
5454 				err = -EROFS;
5455 				goto err_out;
5456 			}
5457 			ext4_msg(sb, KERN_INFO, "write access will "
5458 			       "be enabled during recovery");
5459 		}
5460 	}
5461 
5462 	if (!(journal->j_flags & JBD2_BARRIER))
5463 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5464 
5465 	if (!ext4_has_feature_journal_needs_recovery(sb))
5466 		err = jbd2_journal_wipe(journal, !really_read_only);
5467 	if (!err) {
5468 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5469 		if (save)
5470 			memcpy(save, ((char *) es) +
5471 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5472 		err = jbd2_journal_load(journal);
5473 		if (save)
5474 			memcpy(((char *) es) + EXT4_S_ERR_START,
5475 			       save, EXT4_S_ERR_LEN);
5476 		kfree(save);
5477 	}
5478 
5479 	if (err) {
5480 		ext4_msg(sb, KERN_ERR, "error loading journal");
5481 		goto err_out;
5482 	}
5483 
5484 	EXT4_SB(sb)->s_journal = journal;
5485 	err = ext4_clear_journal_err(sb, es);
5486 	if (err) {
5487 		EXT4_SB(sb)->s_journal = NULL;
5488 		jbd2_journal_destroy(journal);
5489 		return err;
5490 	}
5491 
5492 	if (!really_read_only && journal_devnum &&
5493 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5494 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5495 
5496 		/* Make sure we flush the recovery flag to disk. */
5497 		ext4_commit_super(sb);
5498 	}
5499 
5500 	return 0;
5501 
5502 err_out:
5503 	jbd2_journal_destroy(journal);
5504 	return err;
5505 }
5506 
5507 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5508 static void ext4_update_super(struct super_block *sb)
5509 {
5510 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5511 	struct ext4_super_block *es = sbi->s_es;
5512 	struct buffer_head *sbh = sbi->s_sbh;
5513 
5514 	lock_buffer(sbh);
5515 	/*
5516 	 * If the file system is mounted read-only, don't update the
5517 	 * superblock write time.  This avoids updating the superblock
5518 	 * write time when we are mounting the root file system
5519 	 * read/only but we need to replay the journal; at that point,
5520 	 * for people who are east of GMT and who make their clock
5521 	 * tick in localtime for Windows bug-for-bug compatibility,
5522 	 * the clock is set in the future, and this will cause e2fsck
5523 	 * to complain and force a full file system check.
5524 	 */
5525 	if (!(sb->s_flags & SB_RDONLY))
5526 		ext4_update_tstamp(es, s_wtime);
5527 	es->s_kbytes_written =
5528 		cpu_to_le64(sbi->s_kbytes_written +
5529 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5530 		      sbi->s_sectors_written_start) >> 1));
5531 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5532 		ext4_free_blocks_count_set(es,
5533 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5534 				&sbi->s_freeclusters_counter)));
5535 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5536 		es->s_free_inodes_count =
5537 			cpu_to_le32(percpu_counter_sum_positive(
5538 				&sbi->s_freeinodes_counter));
5539 	/* Copy error information to the on-disk superblock */
5540 	spin_lock(&sbi->s_error_lock);
5541 	if (sbi->s_add_error_count > 0) {
5542 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5543 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5544 			__ext4_update_tstamp(&es->s_first_error_time,
5545 					     &es->s_first_error_time_hi,
5546 					     sbi->s_first_error_time);
5547 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5548 				sizeof(es->s_first_error_func));
5549 			es->s_first_error_line =
5550 				cpu_to_le32(sbi->s_first_error_line);
5551 			es->s_first_error_ino =
5552 				cpu_to_le32(sbi->s_first_error_ino);
5553 			es->s_first_error_block =
5554 				cpu_to_le64(sbi->s_first_error_block);
5555 			es->s_first_error_errcode =
5556 				ext4_errno_to_code(sbi->s_first_error_code);
5557 		}
5558 		__ext4_update_tstamp(&es->s_last_error_time,
5559 				     &es->s_last_error_time_hi,
5560 				     sbi->s_last_error_time);
5561 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5562 			sizeof(es->s_last_error_func));
5563 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5564 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5565 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5566 		es->s_last_error_errcode =
5567 				ext4_errno_to_code(sbi->s_last_error_code);
5568 		/*
5569 		 * Start the daily error reporting function if it hasn't been
5570 		 * started already
5571 		 */
5572 		if (!es->s_error_count)
5573 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5574 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5575 		sbi->s_add_error_count = 0;
5576 	}
5577 	spin_unlock(&sbi->s_error_lock);
5578 
5579 	ext4_superblock_csum_set(sb);
5580 	unlock_buffer(sbh);
5581 }
5582 
5583 static int ext4_commit_super(struct super_block *sb)
5584 {
5585 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5586 	int error = 0;
5587 
5588 	if (!sbh)
5589 		return -EINVAL;
5590 	if (block_device_ejected(sb))
5591 		return -ENODEV;
5592 
5593 	ext4_update_super(sb);
5594 
5595 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5596 		/*
5597 		 * Oh, dear.  A previous attempt to write the
5598 		 * superblock failed.  This could happen because the
5599 		 * USB device was yanked out.  Or it could happen to
5600 		 * be a transient write error and maybe the block will
5601 		 * be remapped.  Nothing we can do but to retry the
5602 		 * write and hope for the best.
5603 		 */
5604 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5605 		       "superblock detected");
5606 		clear_buffer_write_io_error(sbh);
5607 		set_buffer_uptodate(sbh);
5608 	}
5609 	BUFFER_TRACE(sbh, "marking dirty");
5610 	mark_buffer_dirty(sbh);
5611 	error = __sync_dirty_buffer(sbh,
5612 		REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5613 	if (buffer_write_io_error(sbh)) {
5614 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
5615 		       "superblock");
5616 		clear_buffer_write_io_error(sbh);
5617 		set_buffer_uptodate(sbh);
5618 	}
5619 	return error;
5620 }
5621 
5622 /*
5623  * Have we just finished recovery?  If so, and if we are mounting (or
5624  * remounting) the filesystem readonly, then we will end up with a
5625  * consistent fs on disk.  Record that fact.
5626  */
5627 static int ext4_mark_recovery_complete(struct super_block *sb,
5628 				       struct ext4_super_block *es)
5629 {
5630 	int err;
5631 	journal_t *journal = EXT4_SB(sb)->s_journal;
5632 
5633 	if (!ext4_has_feature_journal(sb)) {
5634 		if (journal != NULL) {
5635 			ext4_error(sb, "Journal got removed while the fs was "
5636 				   "mounted!");
5637 			return -EFSCORRUPTED;
5638 		}
5639 		return 0;
5640 	}
5641 	jbd2_journal_lock_updates(journal);
5642 	err = jbd2_journal_flush(journal, 0);
5643 	if (err < 0)
5644 		goto out;
5645 
5646 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5647 		ext4_clear_feature_journal_needs_recovery(sb);
5648 		ext4_commit_super(sb);
5649 	}
5650 out:
5651 	jbd2_journal_unlock_updates(journal);
5652 	return err;
5653 }
5654 
5655 /*
5656  * If we are mounting (or read-write remounting) a filesystem whose journal
5657  * has recorded an error from a previous lifetime, move that error to the
5658  * main filesystem now.
5659  */
5660 static int ext4_clear_journal_err(struct super_block *sb,
5661 				   struct ext4_super_block *es)
5662 {
5663 	journal_t *journal;
5664 	int j_errno;
5665 	const char *errstr;
5666 
5667 	if (!ext4_has_feature_journal(sb)) {
5668 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5669 		return -EFSCORRUPTED;
5670 	}
5671 
5672 	journal = EXT4_SB(sb)->s_journal;
5673 
5674 	/*
5675 	 * Now check for any error status which may have been recorded in the
5676 	 * journal by a prior ext4_error() or ext4_abort()
5677 	 */
5678 
5679 	j_errno = jbd2_journal_errno(journal);
5680 	if (j_errno) {
5681 		char nbuf[16];
5682 
5683 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5684 		ext4_warning(sb, "Filesystem error recorded "
5685 			     "from previous mount: %s", errstr);
5686 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5687 
5688 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5689 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5690 		ext4_commit_super(sb);
5691 
5692 		jbd2_journal_clear_err(journal);
5693 		jbd2_journal_update_sb_errno(journal);
5694 	}
5695 	return 0;
5696 }
5697 
5698 /*
5699  * Force the running and committing transactions to commit,
5700  * and wait on the commit.
5701  */
5702 int ext4_force_commit(struct super_block *sb)
5703 {
5704 	journal_t *journal;
5705 
5706 	if (sb_rdonly(sb))
5707 		return 0;
5708 
5709 	journal = EXT4_SB(sb)->s_journal;
5710 	return ext4_journal_force_commit(journal);
5711 }
5712 
5713 static int ext4_sync_fs(struct super_block *sb, int wait)
5714 {
5715 	int ret = 0;
5716 	tid_t target;
5717 	bool needs_barrier = false;
5718 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5719 
5720 	if (unlikely(ext4_forced_shutdown(sbi)))
5721 		return 0;
5722 
5723 	trace_ext4_sync_fs(sb, wait);
5724 	flush_workqueue(sbi->rsv_conversion_wq);
5725 	/*
5726 	 * Writeback quota in non-journalled quota case - journalled quota has
5727 	 * no dirty dquots
5728 	 */
5729 	dquot_writeback_dquots(sb, -1);
5730 	/*
5731 	 * Data writeback is possible w/o journal transaction, so barrier must
5732 	 * being sent at the end of the function. But we can skip it if
5733 	 * transaction_commit will do it for us.
5734 	 */
5735 	if (sbi->s_journal) {
5736 		target = jbd2_get_latest_transaction(sbi->s_journal);
5737 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5738 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5739 			needs_barrier = true;
5740 
5741 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5742 			if (wait)
5743 				ret = jbd2_log_wait_commit(sbi->s_journal,
5744 							   target);
5745 		}
5746 	} else if (wait && test_opt(sb, BARRIER))
5747 		needs_barrier = true;
5748 	if (needs_barrier) {
5749 		int err;
5750 		err = blkdev_issue_flush(sb->s_bdev);
5751 		if (!ret)
5752 			ret = err;
5753 	}
5754 
5755 	return ret;
5756 }
5757 
5758 /*
5759  * LVM calls this function before a (read-only) snapshot is created.  This
5760  * gives us a chance to flush the journal completely and mark the fs clean.
5761  *
5762  * Note that only this function cannot bring a filesystem to be in a clean
5763  * state independently. It relies on upper layer to stop all data & metadata
5764  * modifications.
5765  */
5766 static int ext4_freeze(struct super_block *sb)
5767 {
5768 	int error = 0;
5769 	journal_t *journal;
5770 
5771 	if (sb_rdonly(sb))
5772 		return 0;
5773 
5774 	journal = EXT4_SB(sb)->s_journal;
5775 
5776 	if (journal) {
5777 		/* Now we set up the journal barrier. */
5778 		jbd2_journal_lock_updates(journal);
5779 
5780 		/*
5781 		 * Don't clear the needs_recovery flag if we failed to
5782 		 * flush the journal.
5783 		 */
5784 		error = jbd2_journal_flush(journal, 0);
5785 		if (error < 0)
5786 			goto out;
5787 
5788 		/* Journal blocked and flushed, clear needs_recovery flag. */
5789 		ext4_clear_feature_journal_needs_recovery(sb);
5790 	}
5791 
5792 	error = ext4_commit_super(sb);
5793 out:
5794 	if (journal)
5795 		/* we rely on upper layer to stop further updates */
5796 		jbd2_journal_unlock_updates(journal);
5797 	return error;
5798 }
5799 
5800 /*
5801  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5802  * flag here, even though the filesystem is not technically dirty yet.
5803  */
5804 static int ext4_unfreeze(struct super_block *sb)
5805 {
5806 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5807 		return 0;
5808 
5809 	if (EXT4_SB(sb)->s_journal) {
5810 		/* Reset the needs_recovery flag before the fs is unlocked. */
5811 		ext4_set_feature_journal_needs_recovery(sb);
5812 	}
5813 
5814 	ext4_commit_super(sb);
5815 	return 0;
5816 }
5817 
5818 /*
5819  * Structure to save mount options for ext4_remount's benefit
5820  */
5821 struct ext4_mount_options {
5822 	unsigned long s_mount_opt;
5823 	unsigned long s_mount_opt2;
5824 	kuid_t s_resuid;
5825 	kgid_t s_resgid;
5826 	unsigned long s_commit_interval;
5827 	u32 s_min_batch_time, s_max_batch_time;
5828 #ifdef CONFIG_QUOTA
5829 	int s_jquota_fmt;
5830 	char *s_qf_names[EXT4_MAXQUOTAS];
5831 #endif
5832 };
5833 
5834 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5835 {
5836 	struct ext4_super_block *es;
5837 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5838 	unsigned long old_sb_flags, vfs_flags;
5839 	struct ext4_mount_options old_opts;
5840 	int enable_quota = 0;
5841 	ext4_group_t g;
5842 	int err = 0;
5843 #ifdef CONFIG_QUOTA
5844 	int i, j;
5845 	char *to_free[EXT4_MAXQUOTAS];
5846 #endif
5847 	char *orig_data = kstrdup(data, GFP_KERNEL);
5848 	struct ext4_parsed_options parsed_opts;
5849 
5850 	parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5851 	parsed_opts.journal_devnum = 0;
5852 
5853 	if (data && !orig_data)
5854 		return -ENOMEM;
5855 
5856 	/* Store the original options */
5857 	old_sb_flags = sb->s_flags;
5858 	old_opts.s_mount_opt = sbi->s_mount_opt;
5859 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5860 	old_opts.s_resuid = sbi->s_resuid;
5861 	old_opts.s_resgid = sbi->s_resgid;
5862 	old_opts.s_commit_interval = sbi->s_commit_interval;
5863 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5864 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5865 #ifdef CONFIG_QUOTA
5866 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5867 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5868 		if (sbi->s_qf_names[i]) {
5869 			char *qf_name = get_qf_name(sb, sbi, i);
5870 
5871 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5872 			if (!old_opts.s_qf_names[i]) {
5873 				for (j = 0; j < i; j++)
5874 					kfree(old_opts.s_qf_names[j]);
5875 				kfree(orig_data);
5876 				return -ENOMEM;
5877 			}
5878 		} else
5879 			old_opts.s_qf_names[i] = NULL;
5880 #endif
5881 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5882 		parsed_opts.journal_ioprio =
5883 			sbi->s_journal->j_task->io_context->ioprio;
5884 
5885 	/*
5886 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5887 	 * either way we need to make sure it matches in both *flags and
5888 	 * s_flags. Copy those selected flags from *flags to s_flags
5889 	 */
5890 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5891 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5892 
5893 	if (!parse_options(data, sb, &parsed_opts, 1)) {
5894 		err = -EINVAL;
5895 		goto restore_opts;
5896 	}
5897 
5898 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5899 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5900 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5901 			 "during remount not supported; ignoring");
5902 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5903 	}
5904 
5905 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5906 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5907 			ext4_msg(sb, KERN_ERR, "can't mount with "
5908 				 "both data=journal and delalloc");
5909 			err = -EINVAL;
5910 			goto restore_opts;
5911 		}
5912 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5913 			ext4_msg(sb, KERN_ERR, "can't mount with "
5914 				 "both data=journal and dioread_nolock");
5915 			err = -EINVAL;
5916 			goto restore_opts;
5917 		}
5918 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5919 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5920 			ext4_msg(sb, KERN_ERR, "can't mount with "
5921 				"journal_async_commit in data=ordered mode");
5922 			err = -EINVAL;
5923 			goto restore_opts;
5924 		}
5925 	}
5926 
5927 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5928 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5929 		err = -EINVAL;
5930 		goto restore_opts;
5931 	}
5932 
5933 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5934 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5935 
5936 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5937 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5938 
5939 	es = sbi->s_es;
5940 
5941 	if (sbi->s_journal) {
5942 		ext4_init_journal_params(sb, sbi->s_journal);
5943 		set_task_ioprio(sbi->s_journal->j_task, parsed_opts.journal_ioprio);
5944 	}
5945 
5946 	/* Flush outstanding errors before changing fs state */
5947 	flush_work(&sbi->s_error_work);
5948 
5949 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5950 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
5951 			err = -EROFS;
5952 			goto restore_opts;
5953 		}
5954 
5955 		if (*flags & SB_RDONLY) {
5956 			err = sync_filesystem(sb);
5957 			if (err < 0)
5958 				goto restore_opts;
5959 			err = dquot_suspend(sb, -1);
5960 			if (err < 0)
5961 				goto restore_opts;
5962 
5963 			/*
5964 			 * First of all, the unconditional stuff we have to do
5965 			 * to disable replay of the journal when we next remount
5966 			 */
5967 			sb->s_flags |= SB_RDONLY;
5968 
5969 			/*
5970 			 * OK, test if we are remounting a valid rw partition
5971 			 * readonly, and if so set the rdonly flag and then
5972 			 * mark the partition as valid again.
5973 			 */
5974 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5975 			    (sbi->s_mount_state & EXT4_VALID_FS))
5976 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5977 
5978 			if (sbi->s_journal) {
5979 				/*
5980 				 * We let remount-ro finish even if marking fs
5981 				 * as clean failed...
5982 				 */
5983 				ext4_mark_recovery_complete(sb, es);
5984 			}
5985 		} else {
5986 			/* Make sure we can mount this feature set readwrite */
5987 			if (ext4_has_feature_readonly(sb) ||
5988 			    !ext4_feature_set_ok(sb, 0)) {
5989 				err = -EROFS;
5990 				goto restore_opts;
5991 			}
5992 			/*
5993 			 * Make sure the group descriptor checksums
5994 			 * are sane.  If they aren't, refuse to remount r/w.
5995 			 */
5996 			for (g = 0; g < sbi->s_groups_count; g++) {
5997 				struct ext4_group_desc *gdp =
5998 					ext4_get_group_desc(sb, g, NULL);
5999 
6000 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6001 					ext4_msg(sb, KERN_ERR,
6002 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6003 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6004 					       le16_to_cpu(gdp->bg_checksum));
6005 					err = -EFSBADCRC;
6006 					goto restore_opts;
6007 				}
6008 			}
6009 
6010 			/*
6011 			 * If we have an unprocessed orphan list hanging
6012 			 * around from a previously readonly bdev mount,
6013 			 * require a full umount/remount for now.
6014 			 */
6015 			if (es->s_last_orphan) {
6016 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6017 				       "remount RDWR because of unprocessed "
6018 				       "orphan inode list.  Please "
6019 				       "umount/remount instead");
6020 				err = -EINVAL;
6021 				goto restore_opts;
6022 			}
6023 
6024 			/*
6025 			 * Mounting a RDONLY partition read-write, so reread
6026 			 * and store the current valid flag.  (It may have
6027 			 * been changed by e2fsck since we originally mounted
6028 			 * the partition.)
6029 			 */
6030 			if (sbi->s_journal) {
6031 				err = ext4_clear_journal_err(sb, es);
6032 				if (err)
6033 					goto restore_opts;
6034 			}
6035 			sbi->s_mount_state = le16_to_cpu(es->s_state);
6036 
6037 			err = ext4_setup_super(sb, es, 0);
6038 			if (err)
6039 				goto restore_opts;
6040 
6041 			sb->s_flags &= ~SB_RDONLY;
6042 			if (ext4_has_feature_mmp(sb))
6043 				if (ext4_multi_mount_protect(sb,
6044 						le64_to_cpu(es->s_mmp_block))) {
6045 					err = -EROFS;
6046 					goto restore_opts;
6047 				}
6048 			enable_quota = 1;
6049 		}
6050 	}
6051 
6052 	/*
6053 	 * Reinitialize lazy itable initialization thread based on
6054 	 * current settings
6055 	 */
6056 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6057 		ext4_unregister_li_request(sb);
6058 	else {
6059 		ext4_group_t first_not_zeroed;
6060 		first_not_zeroed = ext4_has_uninit_itable(sb);
6061 		ext4_register_li_request(sb, first_not_zeroed);
6062 	}
6063 
6064 	/*
6065 	 * Handle creation of system zone data early because it can fail.
6066 	 * Releasing of existing data is done when we are sure remount will
6067 	 * succeed.
6068 	 */
6069 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6070 		err = ext4_setup_system_zone(sb);
6071 		if (err)
6072 			goto restore_opts;
6073 	}
6074 
6075 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6076 		err = ext4_commit_super(sb);
6077 		if (err)
6078 			goto restore_opts;
6079 	}
6080 
6081 #ifdef CONFIG_QUOTA
6082 	/* Release old quota file names */
6083 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6084 		kfree(old_opts.s_qf_names[i]);
6085 	if (enable_quota) {
6086 		if (sb_any_quota_suspended(sb))
6087 			dquot_resume(sb, -1);
6088 		else if (ext4_has_feature_quota(sb)) {
6089 			err = ext4_enable_quotas(sb);
6090 			if (err)
6091 				goto restore_opts;
6092 		}
6093 	}
6094 #endif
6095 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6096 		ext4_release_system_zone(sb);
6097 
6098 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6099 		ext4_stop_mmpd(sbi);
6100 
6101 	/*
6102 	 * Some options can be enabled by ext4 and/or by VFS mount flag
6103 	 * either way we need to make sure it matches in both *flags and
6104 	 * s_flags. Copy those selected flags from s_flags to *flags
6105 	 */
6106 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6107 
6108 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s. Quota mode: %s.",
6109 		 orig_data, ext4_quota_mode(sb));
6110 	kfree(orig_data);
6111 	return 0;
6112 
6113 restore_opts:
6114 	sb->s_flags = old_sb_flags;
6115 	sbi->s_mount_opt = old_opts.s_mount_opt;
6116 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6117 	sbi->s_resuid = old_opts.s_resuid;
6118 	sbi->s_resgid = old_opts.s_resgid;
6119 	sbi->s_commit_interval = old_opts.s_commit_interval;
6120 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6121 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6122 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6123 		ext4_release_system_zone(sb);
6124 #ifdef CONFIG_QUOTA
6125 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6126 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6127 		to_free[i] = get_qf_name(sb, sbi, i);
6128 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6129 	}
6130 	synchronize_rcu();
6131 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6132 		kfree(to_free[i]);
6133 #endif
6134 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6135 		ext4_stop_mmpd(sbi);
6136 	kfree(orig_data);
6137 	return err;
6138 }
6139 
6140 #ifdef CONFIG_QUOTA
6141 static int ext4_statfs_project(struct super_block *sb,
6142 			       kprojid_t projid, struct kstatfs *buf)
6143 {
6144 	struct kqid qid;
6145 	struct dquot *dquot;
6146 	u64 limit;
6147 	u64 curblock;
6148 
6149 	qid = make_kqid_projid(projid);
6150 	dquot = dqget(sb, qid);
6151 	if (IS_ERR(dquot))
6152 		return PTR_ERR(dquot);
6153 	spin_lock(&dquot->dq_dqb_lock);
6154 
6155 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6156 			     dquot->dq_dqb.dqb_bhardlimit);
6157 	limit >>= sb->s_blocksize_bits;
6158 
6159 	if (limit && buf->f_blocks > limit) {
6160 		curblock = (dquot->dq_dqb.dqb_curspace +
6161 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6162 		buf->f_blocks = limit;
6163 		buf->f_bfree = buf->f_bavail =
6164 			(buf->f_blocks > curblock) ?
6165 			 (buf->f_blocks - curblock) : 0;
6166 	}
6167 
6168 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6169 			     dquot->dq_dqb.dqb_ihardlimit);
6170 	if (limit && buf->f_files > limit) {
6171 		buf->f_files = limit;
6172 		buf->f_ffree =
6173 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6174 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6175 	}
6176 
6177 	spin_unlock(&dquot->dq_dqb_lock);
6178 	dqput(dquot);
6179 	return 0;
6180 }
6181 #endif
6182 
6183 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6184 {
6185 	struct super_block *sb = dentry->d_sb;
6186 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6187 	struct ext4_super_block *es = sbi->s_es;
6188 	ext4_fsblk_t overhead = 0, resv_blocks;
6189 	s64 bfree;
6190 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6191 
6192 	if (!test_opt(sb, MINIX_DF))
6193 		overhead = sbi->s_overhead;
6194 
6195 	buf->f_type = EXT4_SUPER_MAGIC;
6196 	buf->f_bsize = sb->s_blocksize;
6197 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6198 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6199 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6200 	/* prevent underflow in case that few free space is available */
6201 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6202 	buf->f_bavail = buf->f_bfree -
6203 			(ext4_r_blocks_count(es) + resv_blocks);
6204 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6205 		buf->f_bavail = 0;
6206 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6207 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6208 	buf->f_namelen = EXT4_NAME_LEN;
6209 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6210 
6211 #ifdef CONFIG_QUOTA
6212 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6213 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6214 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6215 #endif
6216 	return 0;
6217 }
6218 
6219 
6220 #ifdef CONFIG_QUOTA
6221 
6222 /*
6223  * Helper functions so that transaction is started before we acquire dqio_sem
6224  * to keep correct lock ordering of transaction > dqio_sem
6225  */
6226 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6227 {
6228 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6229 }
6230 
6231 static int ext4_write_dquot(struct dquot *dquot)
6232 {
6233 	int ret, err;
6234 	handle_t *handle;
6235 	struct inode *inode;
6236 
6237 	inode = dquot_to_inode(dquot);
6238 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6239 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6240 	if (IS_ERR(handle))
6241 		return PTR_ERR(handle);
6242 	ret = dquot_commit(dquot);
6243 	err = ext4_journal_stop(handle);
6244 	if (!ret)
6245 		ret = err;
6246 	return ret;
6247 }
6248 
6249 static int ext4_acquire_dquot(struct dquot *dquot)
6250 {
6251 	int ret, err;
6252 	handle_t *handle;
6253 
6254 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6255 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6256 	if (IS_ERR(handle))
6257 		return PTR_ERR(handle);
6258 	ret = dquot_acquire(dquot);
6259 	err = ext4_journal_stop(handle);
6260 	if (!ret)
6261 		ret = err;
6262 	return ret;
6263 }
6264 
6265 static int ext4_release_dquot(struct dquot *dquot)
6266 {
6267 	int ret, err;
6268 	handle_t *handle;
6269 
6270 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6271 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6272 	if (IS_ERR(handle)) {
6273 		/* Release dquot anyway to avoid endless cycle in dqput() */
6274 		dquot_release(dquot);
6275 		return PTR_ERR(handle);
6276 	}
6277 	ret = dquot_release(dquot);
6278 	err = ext4_journal_stop(handle);
6279 	if (!ret)
6280 		ret = err;
6281 	return ret;
6282 }
6283 
6284 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6285 {
6286 	struct super_block *sb = dquot->dq_sb;
6287 
6288 	if (ext4_is_quota_journalled(sb)) {
6289 		dquot_mark_dquot_dirty(dquot);
6290 		return ext4_write_dquot(dquot);
6291 	} else {
6292 		return dquot_mark_dquot_dirty(dquot);
6293 	}
6294 }
6295 
6296 static int ext4_write_info(struct super_block *sb, int type)
6297 {
6298 	int ret, err;
6299 	handle_t *handle;
6300 
6301 	/* Data block + inode block */
6302 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6303 	if (IS_ERR(handle))
6304 		return PTR_ERR(handle);
6305 	ret = dquot_commit_info(sb, type);
6306 	err = ext4_journal_stop(handle);
6307 	if (!ret)
6308 		ret = err;
6309 	return ret;
6310 }
6311 
6312 /*
6313  * Turn on quotas during mount time - we need to find
6314  * the quota file and such...
6315  */
6316 static int ext4_quota_on_mount(struct super_block *sb, int type)
6317 {
6318 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6319 					EXT4_SB(sb)->s_jquota_fmt, type);
6320 }
6321 
6322 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6323 {
6324 	struct ext4_inode_info *ei = EXT4_I(inode);
6325 
6326 	/* The first argument of lockdep_set_subclass has to be
6327 	 * *exactly* the same as the argument to init_rwsem() --- in
6328 	 * this case, in init_once() --- or lockdep gets unhappy
6329 	 * because the name of the lock is set using the
6330 	 * stringification of the argument to init_rwsem().
6331 	 */
6332 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6333 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6334 }
6335 
6336 /*
6337  * Standard function to be called on quota_on
6338  */
6339 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6340 			 const struct path *path)
6341 {
6342 	int err;
6343 
6344 	if (!test_opt(sb, QUOTA))
6345 		return -EINVAL;
6346 
6347 	/* Quotafile not on the same filesystem? */
6348 	if (path->dentry->d_sb != sb)
6349 		return -EXDEV;
6350 
6351 	/* Quota already enabled for this file? */
6352 	if (IS_NOQUOTA(d_inode(path->dentry)))
6353 		return -EBUSY;
6354 
6355 	/* Journaling quota? */
6356 	if (EXT4_SB(sb)->s_qf_names[type]) {
6357 		/* Quotafile not in fs root? */
6358 		if (path->dentry->d_parent != sb->s_root)
6359 			ext4_msg(sb, KERN_WARNING,
6360 				"Quota file not on filesystem root. "
6361 				"Journaled quota will not work");
6362 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6363 	} else {
6364 		/*
6365 		 * Clear the flag just in case mount options changed since
6366 		 * last time.
6367 		 */
6368 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6369 	}
6370 
6371 	/*
6372 	 * When we journal data on quota file, we have to flush journal to see
6373 	 * all updates to the file when we bypass pagecache...
6374 	 */
6375 	if (EXT4_SB(sb)->s_journal &&
6376 	    ext4_should_journal_data(d_inode(path->dentry))) {
6377 		/*
6378 		 * We don't need to lock updates but journal_flush() could
6379 		 * otherwise be livelocked...
6380 		 */
6381 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6382 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6383 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6384 		if (err)
6385 			return err;
6386 	}
6387 
6388 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6389 	err = dquot_quota_on(sb, type, format_id, path);
6390 	if (err) {
6391 		lockdep_set_quota_inode(path->dentry->d_inode,
6392 					     I_DATA_SEM_NORMAL);
6393 	} else {
6394 		struct inode *inode = d_inode(path->dentry);
6395 		handle_t *handle;
6396 
6397 		/*
6398 		 * Set inode flags to prevent userspace from messing with quota
6399 		 * files. If this fails, we return success anyway since quotas
6400 		 * are already enabled and this is not a hard failure.
6401 		 */
6402 		inode_lock(inode);
6403 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6404 		if (IS_ERR(handle))
6405 			goto unlock_inode;
6406 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6407 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6408 				S_NOATIME | S_IMMUTABLE);
6409 		err = ext4_mark_inode_dirty(handle, inode);
6410 		ext4_journal_stop(handle);
6411 	unlock_inode:
6412 		inode_unlock(inode);
6413 	}
6414 	return err;
6415 }
6416 
6417 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6418 			     unsigned int flags)
6419 {
6420 	int err;
6421 	struct inode *qf_inode;
6422 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6423 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6424 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6425 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6426 	};
6427 
6428 	BUG_ON(!ext4_has_feature_quota(sb));
6429 
6430 	if (!qf_inums[type])
6431 		return -EPERM;
6432 
6433 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6434 	if (IS_ERR(qf_inode)) {
6435 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6436 		return PTR_ERR(qf_inode);
6437 	}
6438 
6439 	/* Don't account quota for quota files to avoid recursion */
6440 	qf_inode->i_flags |= S_NOQUOTA;
6441 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6442 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6443 	if (err)
6444 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6445 	iput(qf_inode);
6446 
6447 	return err;
6448 }
6449 
6450 /* Enable usage tracking for all quota types. */
6451 static int ext4_enable_quotas(struct super_block *sb)
6452 {
6453 	int type, err = 0;
6454 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6455 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6456 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6457 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6458 	};
6459 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6460 		test_opt(sb, USRQUOTA),
6461 		test_opt(sb, GRPQUOTA),
6462 		test_opt(sb, PRJQUOTA),
6463 	};
6464 
6465 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6466 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6467 		if (qf_inums[type]) {
6468 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6469 				DQUOT_USAGE_ENABLED |
6470 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6471 			if (err) {
6472 				ext4_warning(sb,
6473 					"Failed to enable quota tracking "
6474 					"(type=%d, err=%d). Please run "
6475 					"e2fsck to fix.", type, err);
6476 				for (type--; type >= 0; type--)
6477 					dquot_quota_off(sb, type);
6478 
6479 				return err;
6480 			}
6481 		}
6482 	}
6483 	return 0;
6484 }
6485 
6486 static int ext4_quota_off(struct super_block *sb, int type)
6487 {
6488 	struct inode *inode = sb_dqopt(sb)->files[type];
6489 	handle_t *handle;
6490 	int err;
6491 
6492 	/* Force all delayed allocation blocks to be allocated.
6493 	 * Caller already holds s_umount sem */
6494 	if (test_opt(sb, DELALLOC))
6495 		sync_filesystem(sb);
6496 
6497 	if (!inode || !igrab(inode))
6498 		goto out;
6499 
6500 	err = dquot_quota_off(sb, type);
6501 	if (err || ext4_has_feature_quota(sb))
6502 		goto out_put;
6503 
6504 	inode_lock(inode);
6505 	/*
6506 	 * Update modification times of quota files when userspace can
6507 	 * start looking at them. If we fail, we return success anyway since
6508 	 * this is not a hard failure and quotas are already disabled.
6509 	 */
6510 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6511 	if (IS_ERR(handle)) {
6512 		err = PTR_ERR(handle);
6513 		goto out_unlock;
6514 	}
6515 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6516 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6517 	inode->i_mtime = inode->i_ctime = current_time(inode);
6518 	err = ext4_mark_inode_dirty(handle, inode);
6519 	ext4_journal_stop(handle);
6520 out_unlock:
6521 	inode_unlock(inode);
6522 out_put:
6523 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6524 	iput(inode);
6525 	return err;
6526 out:
6527 	return dquot_quota_off(sb, type);
6528 }
6529 
6530 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6531  * acquiring the locks... As quota files are never truncated and quota code
6532  * itself serializes the operations (and no one else should touch the files)
6533  * we don't have to be afraid of races */
6534 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6535 			       size_t len, loff_t off)
6536 {
6537 	struct inode *inode = sb_dqopt(sb)->files[type];
6538 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6539 	int offset = off & (sb->s_blocksize - 1);
6540 	int tocopy;
6541 	size_t toread;
6542 	struct buffer_head *bh;
6543 	loff_t i_size = i_size_read(inode);
6544 
6545 	if (off > i_size)
6546 		return 0;
6547 	if (off+len > i_size)
6548 		len = i_size-off;
6549 	toread = len;
6550 	while (toread > 0) {
6551 		tocopy = sb->s_blocksize - offset < toread ?
6552 				sb->s_blocksize - offset : toread;
6553 		bh = ext4_bread(NULL, inode, blk, 0);
6554 		if (IS_ERR(bh))
6555 			return PTR_ERR(bh);
6556 		if (!bh)	/* A hole? */
6557 			memset(data, 0, tocopy);
6558 		else
6559 			memcpy(data, bh->b_data+offset, tocopy);
6560 		brelse(bh);
6561 		offset = 0;
6562 		toread -= tocopy;
6563 		data += tocopy;
6564 		blk++;
6565 	}
6566 	return len;
6567 }
6568 
6569 /* Write to quotafile (we know the transaction is already started and has
6570  * enough credits) */
6571 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6572 				const char *data, size_t len, loff_t off)
6573 {
6574 	struct inode *inode = sb_dqopt(sb)->files[type];
6575 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6576 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6577 	int retries = 0;
6578 	struct buffer_head *bh;
6579 	handle_t *handle = journal_current_handle();
6580 
6581 	if (EXT4_SB(sb)->s_journal && !handle) {
6582 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6583 			" cancelled because transaction is not started",
6584 			(unsigned long long)off, (unsigned long long)len);
6585 		return -EIO;
6586 	}
6587 	/*
6588 	 * Since we account only one data block in transaction credits,
6589 	 * then it is impossible to cross a block boundary.
6590 	 */
6591 	if (sb->s_blocksize - offset < len) {
6592 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6593 			" cancelled because not block aligned",
6594 			(unsigned long long)off, (unsigned long long)len);
6595 		return -EIO;
6596 	}
6597 
6598 	do {
6599 		bh = ext4_bread(handle, inode, blk,
6600 				EXT4_GET_BLOCKS_CREATE |
6601 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6602 	} while (PTR_ERR(bh) == -ENOSPC &&
6603 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6604 	if (IS_ERR(bh))
6605 		return PTR_ERR(bh);
6606 	if (!bh)
6607 		goto out;
6608 	BUFFER_TRACE(bh, "get write access");
6609 	err = ext4_journal_get_write_access(handle, bh);
6610 	if (err) {
6611 		brelse(bh);
6612 		return err;
6613 	}
6614 	lock_buffer(bh);
6615 	memcpy(bh->b_data+offset, data, len);
6616 	flush_dcache_page(bh->b_page);
6617 	unlock_buffer(bh);
6618 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6619 	brelse(bh);
6620 out:
6621 	if (inode->i_size < off + len) {
6622 		i_size_write(inode, off + len);
6623 		EXT4_I(inode)->i_disksize = inode->i_size;
6624 		err2 = ext4_mark_inode_dirty(handle, inode);
6625 		if (unlikely(err2 && !err))
6626 			err = err2;
6627 	}
6628 	return err ? err : len;
6629 }
6630 #endif
6631 
6632 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6633 		       const char *dev_name, void *data)
6634 {
6635 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6636 }
6637 
6638 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6639 static inline void register_as_ext2(void)
6640 {
6641 	int err = register_filesystem(&ext2_fs_type);
6642 	if (err)
6643 		printk(KERN_WARNING
6644 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6645 }
6646 
6647 static inline void unregister_as_ext2(void)
6648 {
6649 	unregister_filesystem(&ext2_fs_type);
6650 }
6651 
6652 static inline int ext2_feature_set_ok(struct super_block *sb)
6653 {
6654 	if (ext4_has_unknown_ext2_incompat_features(sb))
6655 		return 0;
6656 	if (sb_rdonly(sb))
6657 		return 1;
6658 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6659 		return 0;
6660 	return 1;
6661 }
6662 #else
6663 static inline void register_as_ext2(void) { }
6664 static inline void unregister_as_ext2(void) { }
6665 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6666 #endif
6667 
6668 static inline void register_as_ext3(void)
6669 {
6670 	int err = register_filesystem(&ext3_fs_type);
6671 	if (err)
6672 		printk(KERN_WARNING
6673 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6674 }
6675 
6676 static inline void unregister_as_ext3(void)
6677 {
6678 	unregister_filesystem(&ext3_fs_type);
6679 }
6680 
6681 static inline int ext3_feature_set_ok(struct super_block *sb)
6682 {
6683 	if (ext4_has_unknown_ext3_incompat_features(sb))
6684 		return 0;
6685 	if (!ext4_has_feature_journal(sb))
6686 		return 0;
6687 	if (sb_rdonly(sb))
6688 		return 1;
6689 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6690 		return 0;
6691 	return 1;
6692 }
6693 
6694 static struct file_system_type ext4_fs_type = {
6695 	.owner		= THIS_MODULE,
6696 	.name		= "ext4",
6697 	.mount		= ext4_mount,
6698 	.kill_sb	= kill_block_super,
6699 	.fs_flags	= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
6700 };
6701 MODULE_ALIAS_FS("ext4");
6702 
6703 /* Shared across all ext4 file systems */
6704 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6705 
6706 static int __init ext4_init_fs(void)
6707 {
6708 	int i, err;
6709 
6710 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6711 	ext4_li_info = NULL;
6712 
6713 	/* Build-time check for flags consistency */
6714 	ext4_check_flag_values();
6715 
6716 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6717 		init_waitqueue_head(&ext4__ioend_wq[i]);
6718 
6719 	err = ext4_init_es();
6720 	if (err)
6721 		return err;
6722 
6723 	err = ext4_init_pending();
6724 	if (err)
6725 		goto out7;
6726 
6727 	err = ext4_init_post_read_processing();
6728 	if (err)
6729 		goto out6;
6730 
6731 	err = ext4_init_pageio();
6732 	if (err)
6733 		goto out5;
6734 
6735 	err = ext4_init_system_zone();
6736 	if (err)
6737 		goto out4;
6738 
6739 	err = ext4_init_sysfs();
6740 	if (err)
6741 		goto out3;
6742 
6743 	err = ext4_init_mballoc();
6744 	if (err)
6745 		goto out2;
6746 	err = init_inodecache();
6747 	if (err)
6748 		goto out1;
6749 
6750 	err = ext4_fc_init_dentry_cache();
6751 	if (err)
6752 		goto out05;
6753 
6754 	register_as_ext3();
6755 	register_as_ext2();
6756 	err = register_filesystem(&ext4_fs_type);
6757 	if (err)
6758 		goto out;
6759 
6760 	return 0;
6761 out:
6762 	unregister_as_ext2();
6763 	unregister_as_ext3();
6764 out05:
6765 	destroy_inodecache();
6766 out1:
6767 	ext4_exit_mballoc();
6768 out2:
6769 	ext4_exit_sysfs();
6770 out3:
6771 	ext4_exit_system_zone();
6772 out4:
6773 	ext4_exit_pageio();
6774 out5:
6775 	ext4_exit_post_read_processing();
6776 out6:
6777 	ext4_exit_pending();
6778 out7:
6779 	ext4_exit_es();
6780 
6781 	return err;
6782 }
6783 
6784 static void __exit ext4_exit_fs(void)
6785 {
6786 	ext4_destroy_lazyinit_thread();
6787 	unregister_as_ext2();
6788 	unregister_as_ext3();
6789 	unregister_filesystem(&ext4_fs_type);
6790 	destroy_inodecache();
6791 	ext4_exit_mballoc();
6792 	ext4_exit_sysfs();
6793 	ext4_exit_system_zone();
6794 	ext4_exit_pageio();
6795 	ext4_exit_post_read_processing();
6796 	ext4_exit_es();
6797 	ext4_exit_pending();
6798 }
6799 
6800 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6801 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6802 MODULE_LICENSE("GPL");
6803 MODULE_SOFTDEP("pre: crc32c");
6804 module_init(ext4_init_fs)
6805 module_exit(ext4_exit_fs)
6806