xref: /openbmc/linux/fs/ext4/super.c (revision 8938c48f)
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  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
94  * i_mmap_rwsem (inode->i_mmap_rwsem)!
95  *
96  * page fault path:
97  * mmap_lock -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
98  *   page lock -> i_data_sem (rw)
99  *
100  * buffered write path:
101  * sb_start_write -> i_mutex -> mmap_lock
102  * sb_start_write -> i_mutex -> transaction start -> page lock ->
103  *   i_data_sem (rw)
104  *
105  * truncate:
106  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
107  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
108  *   i_data_sem (rw)
109  *
110  * direct IO:
111  * sb_start_write -> i_mutex -> mmap_lock
112  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
113  *
114  * writepages:
115  * transaction start -> page lock(s) -> i_data_sem (rw)
116  */
117 
118 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
119 static struct file_system_type ext2_fs_type = {
120 	.owner		= THIS_MODULE,
121 	.name		= "ext2",
122 	.mount		= ext4_mount,
123 	.kill_sb	= kill_block_super,
124 	.fs_flags	= FS_REQUIRES_DEV,
125 };
126 MODULE_ALIAS_FS("ext2");
127 MODULE_ALIAS("ext2");
128 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
129 #else
130 #define IS_EXT2_SB(sb) (0)
131 #endif
132 
133 
134 static struct file_system_type ext3_fs_type = {
135 	.owner		= THIS_MODULE,
136 	.name		= "ext3",
137 	.mount		= ext4_mount,
138 	.kill_sb	= kill_block_super,
139 	.fs_flags	= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext3");
142 MODULE_ALIAS("ext3");
143 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
144 
145 
146 static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags,
147 				  bh_end_io_t *end_io)
148 {
149 	/*
150 	 * buffer's verified bit is no longer valid after reading from
151 	 * disk again due to write out error, clear it to make sure we
152 	 * recheck the buffer contents.
153 	 */
154 	clear_buffer_verified(bh);
155 
156 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
157 	get_bh(bh);
158 	submit_bh(REQ_OP_READ, op_flags, bh);
159 }
160 
161 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
162 			 bh_end_io_t *end_io)
163 {
164 	BUG_ON(!buffer_locked(bh));
165 
166 	if (ext4_buffer_uptodate(bh)) {
167 		unlock_buffer(bh);
168 		return;
169 	}
170 	__ext4_read_bh(bh, op_flags, end_io);
171 }
172 
173 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
174 {
175 	BUG_ON(!buffer_locked(bh));
176 
177 	if (ext4_buffer_uptodate(bh)) {
178 		unlock_buffer(bh);
179 		return 0;
180 	}
181 
182 	__ext4_read_bh(bh, op_flags, end_io);
183 
184 	wait_on_buffer(bh);
185 	if (buffer_uptodate(bh))
186 		return 0;
187 	return -EIO;
188 }
189 
190 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
191 {
192 	if (trylock_buffer(bh)) {
193 		if (wait)
194 			return ext4_read_bh(bh, op_flags, NULL);
195 		ext4_read_bh_nowait(bh, op_flags, NULL);
196 		return 0;
197 	}
198 	if (wait) {
199 		wait_on_buffer(bh);
200 		if (buffer_uptodate(bh))
201 			return 0;
202 		return -EIO;
203 	}
204 	return 0;
205 }
206 
207 /*
208  * This works like __bread_gfp() except it uses ERR_PTR for error
209  * returns.  Currently with sb_bread it's impossible to distinguish
210  * between ENOMEM and EIO situations (since both result in a NULL
211  * return.
212  */
213 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
214 					       sector_t block, int op_flags,
215 					       gfp_t gfp)
216 {
217 	struct buffer_head *bh;
218 	int ret;
219 
220 	bh = sb_getblk_gfp(sb, block, gfp);
221 	if (bh == NULL)
222 		return ERR_PTR(-ENOMEM);
223 	if (ext4_buffer_uptodate(bh))
224 		return bh;
225 
226 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
227 	if (ret) {
228 		put_bh(bh);
229 		return ERR_PTR(ret);
230 	}
231 	return bh;
232 }
233 
234 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
235 				   int op_flags)
236 {
237 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
238 }
239 
240 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
241 					    sector_t block)
242 {
243 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
244 }
245 
246 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
247 {
248 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
249 
250 	if (likely(bh)) {
251 		ext4_read_bh_lock(bh, REQ_RAHEAD, false);
252 		brelse(bh);
253 	}
254 }
255 
256 static int ext4_verify_csum_type(struct super_block *sb,
257 				 struct ext4_super_block *es)
258 {
259 	if (!ext4_has_feature_metadata_csum(sb))
260 		return 1;
261 
262 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
263 }
264 
265 static __le32 ext4_superblock_csum(struct super_block *sb,
266 				   struct ext4_super_block *es)
267 {
268 	struct ext4_sb_info *sbi = EXT4_SB(sb);
269 	int offset = offsetof(struct ext4_super_block, s_checksum);
270 	__u32 csum;
271 
272 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
273 
274 	return cpu_to_le32(csum);
275 }
276 
277 static int ext4_superblock_csum_verify(struct super_block *sb,
278 				       struct ext4_super_block *es)
279 {
280 	if (!ext4_has_metadata_csum(sb))
281 		return 1;
282 
283 	return es->s_checksum == ext4_superblock_csum(sb, es);
284 }
285 
286 void ext4_superblock_csum_set(struct super_block *sb)
287 {
288 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
289 
290 	if (!ext4_has_metadata_csum(sb))
291 		return;
292 
293 	es->s_checksum = ext4_superblock_csum(sb, es);
294 }
295 
296 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
297 			       struct ext4_group_desc *bg)
298 {
299 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
300 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
301 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
302 }
303 
304 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
305 			       struct ext4_group_desc *bg)
306 {
307 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
308 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
309 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
310 }
311 
312 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
313 			      struct ext4_group_desc *bg)
314 {
315 	return le32_to_cpu(bg->bg_inode_table_lo) |
316 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
317 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
318 }
319 
320 __u32 ext4_free_group_clusters(struct super_block *sb,
321 			       struct ext4_group_desc *bg)
322 {
323 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
324 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
325 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
326 }
327 
328 __u32 ext4_free_inodes_count(struct super_block *sb,
329 			      struct ext4_group_desc *bg)
330 {
331 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
332 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
333 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
334 }
335 
336 __u32 ext4_used_dirs_count(struct super_block *sb,
337 			      struct ext4_group_desc *bg)
338 {
339 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
340 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
341 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
342 }
343 
344 __u32 ext4_itable_unused_count(struct super_block *sb,
345 			      struct ext4_group_desc *bg)
346 {
347 	return le16_to_cpu(bg->bg_itable_unused_lo) |
348 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
349 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
350 }
351 
352 void ext4_block_bitmap_set(struct super_block *sb,
353 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
354 {
355 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
356 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
357 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
358 }
359 
360 void ext4_inode_bitmap_set(struct super_block *sb,
361 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
362 {
363 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
364 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
365 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
366 }
367 
368 void ext4_inode_table_set(struct super_block *sb,
369 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
370 {
371 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
372 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
373 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
374 }
375 
376 void ext4_free_group_clusters_set(struct super_block *sb,
377 				  struct ext4_group_desc *bg, __u32 count)
378 {
379 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
380 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
381 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
382 }
383 
384 void ext4_free_inodes_set(struct super_block *sb,
385 			  struct ext4_group_desc *bg, __u32 count)
386 {
387 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
388 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
389 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
390 }
391 
392 void ext4_used_dirs_set(struct super_block *sb,
393 			  struct ext4_group_desc *bg, __u32 count)
394 {
395 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
396 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
397 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
398 }
399 
400 void ext4_itable_unused_set(struct super_block *sb,
401 			  struct ext4_group_desc *bg, __u32 count)
402 {
403 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
404 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
405 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
406 }
407 
408 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
409 {
410 	now = clamp_val(now, 0, (1ull << 40) - 1);
411 
412 	*lo = cpu_to_le32(lower_32_bits(now));
413 	*hi = upper_32_bits(now);
414 }
415 
416 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
417 {
418 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
419 }
420 #define ext4_update_tstamp(es, tstamp) \
421 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
422 			     ktime_get_real_seconds())
423 #define ext4_get_tstamp(es, tstamp) \
424 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
425 
426 /*
427  * The del_gendisk() function uninitializes the disk-specific data
428  * structures, including the bdi structure, without telling anyone
429  * else.  Once this happens, any attempt to call mark_buffer_dirty()
430  * (for example, by ext4_commit_super), will cause a kernel OOPS.
431  * This is a kludge to prevent these oops until we can put in a proper
432  * hook in del_gendisk() to inform the VFS and file system layers.
433  */
434 static int block_device_ejected(struct super_block *sb)
435 {
436 	struct inode *bd_inode = sb->s_bdev->bd_inode;
437 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
438 
439 	return bdi->dev == NULL;
440 }
441 
442 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
443 {
444 	struct super_block		*sb = journal->j_private;
445 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
446 	int				error = is_journal_aborted(journal);
447 	struct ext4_journal_cb_entry	*jce;
448 
449 	BUG_ON(txn->t_state == T_FINISHED);
450 
451 	ext4_process_freed_data(sb, txn->t_tid);
452 
453 	spin_lock(&sbi->s_md_lock);
454 	while (!list_empty(&txn->t_private_list)) {
455 		jce = list_entry(txn->t_private_list.next,
456 				 struct ext4_journal_cb_entry, jce_list);
457 		list_del_init(&jce->jce_list);
458 		spin_unlock(&sbi->s_md_lock);
459 		jce->jce_func(sb, jce, error);
460 		spin_lock(&sbi->s_md_lock);
461 	}
462 	spin_unlock(&sbi->s_md_lock);
463 }
464 
465 /*
466  * This writepage callback for write_cache_pages()
467  * takes care of a few cases after page cleaning.
468  *
469  * write_cache_pages() already checks for dirty pages
470  * and calls clear_page_dirty_for_io(), which we want,
471  * to write protect the pages.
472  *
473  * However, we may have to redirty a page (see below.)
474  */
475 static int ext4_journalled_writepage_callback(struct page *page,
476 					      struct writeback_control *wbc,
477 					      void *data)
478 {
479 	transaction_t *transaction = (transaction_t *) data;
480 	struct buffer_head *bh, *head;
481 	struct journal_head *jh;
482 
483 	bh = head = page_buffers(page);
484 	do {
485 		/*
486 		 * We have to redirty a page in these cases:
487 		 * 1) If buffer is dirty, it means the page was dirty because it
488 		 * contains a buffer that needs checkpointing. So the dirty bit
489 		 * needs to be preserved so that checkpointing writes the buffer
490 		 * properly.
491 		 * 2) If buffer is not part of the committing transaction
492 		 * (we may have just accidentally come across this buffer because
493 		 * inode range tracking is not exact) or if the currently running
494 		 * transaction already contains this buffer as well, dirty bit
495 		 * needs to be preserved so that the buffer gets writeprotected
496 		 * properly on running transaction's commit.
497 		 */
498 		jh = bh2jh(bh);
499 		if (buffer_dirty(bh) ||
500 		    (jh && (jh->b_transaction != transaction ||
501 			    jh->b_next_transaction))) {
502 			redirty_page_for_writepage(wbc, page);
503 			goto out;
504 		}
505 	} while ((bh = bh->b_this_page) != head);
506 
507 out:
508 	return AOP_WRITEPAGE_ACTIVATE;
509 }
510 
511 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
512 {
513 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
514 	struct writeback_control wbc = {
515 		.sync_mode =  WB_SYNC_ALL,
516 		.nr_to_write = LONG_MAX,
517 		.range_start = jinode->i_dirty_start,
518 		.range_end = jinode->i_dirty_end,
519         };
520 
521 	return write_cache_pages(mapping, &wbc,
522 				 ext4_journalled_writepage_callback,
523 				 jinode->i_transaction);
524 }
525 
526 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
527 {
528 	int ret;
529 
530 	if (ext4_should_journal_data(jinode->i_vfs_inode))
531 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
532 	else
533 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
534 
535 	return ret;
536 }
537 
538 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
539 {
540 	int ret = 0;
541 
542 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
543 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
544 
545 	return ret;
546 }
547 
548 static bool system_going_down(void)
549 {
550 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
551 		|| system_state == SYSTEM_RESTART;
552 }
553 
554 struct ext4_err_translation {
555 	int code;
556 	int errno;
557 };
558 
559 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
560 
561 static struct ext4_err_translation err_translation[] = {
562 	EXT4_ERR_TRANSLATE(EIO),
563 	EXT4_ERR_TRANSLATE(ENOMEM),
564 	EXT4_ERR_TRANSLATE(EFSBADCRC),
565 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
566 	EXT4_ERR_TRANSLATE(ENOSPC),
567 	EXT4_ERR_TRANSLATE(ENOKEY),
568 	EXT4_ERR_TRANSLATE(EROFS),
569 	EXT4_ERR_TRANSLATE(EFBIG),
570 	EXT4_ERR_TRANSLATE(EEXIST),
571 	EXT4_ERR_TRANSLATE(ERANGE),
572 	EXT4_ERR_TRANSLATE(EOVERFLOW),
573 	EXT4_ERR_TRANSLATE(EBUSY),
574 	EXT4_ERR_TRANSLATE(ENOTDIR),
575 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
576 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
577 	EXT4_ERR_TRANSLATE(EFAULT),
578 };
579 
580 static int ext4_errno_to_code(int errno)
581 {
582 	int i;
583 
584 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
585 		if (err_translation[i].errno == errno)
586 			return err_translation[i].code;
587 	return EXT4_ERR_UNKNOWN;
588 }
589 
590 static void save_error_info(struct super_block *sb, int error,
591 			    __u32 ino, __u64 block,
592 			    const char *func, unsigned int line)
593 {
594 	struct ext4_sb_info *sbi = EXT4_SB(sb);
595 
596 	/* We default to EFSCORRUPTED error... */
597 	if (error == 0)
598 		error = EFSCORRUPTED;
599 
600 	spin_lock(&sbi->s_error_lock);
601 	sbi->s_add_error_count++;
602 	sbi->s_last_error_code = error;
603 	sbi->s_last_error_line = line;
604 	sbi->s_last_error_ino = ino;
605 	sbi->s_last_error_block = block;
606 	sbi->s_last_error_func = func;
607 	sbi->s_last_error_time = ktime_get_real_seconds();
608 	if (!sbi->s_first_error_time) {
609 		sbi->s_first_error_code = error;
610 		sbi->s_first_error_line = line;
611 		sbi->s_first_error_ino = ino;
612 		sbi->s_first_error_block = block;
613 		sbi->s_first_error_func = func;
614 		sbi->s_first_error_time = sbi->s_last_error_time;
615 	}
616 	spin_unlock(&sbi->s_error_lock);
617 }
618 
619 /* Deal with the reporting of failure conditions on a filesystem such as
620  * inconsistencies detected or read IO failures.
621  *
622  * On ext2, we can store the error state of the filesystem in the
623  * superblock.  That is not possible on ext4, because we may have other
624  * write ordering constraints on the superblock which prevent us from
625  * writing it out straight away; and given that the journal is about to
626  * be aborted, we can't rely on the current, or future, transactions to
627  * write out the superblock safely.
628  *
629  * We'll just use the jbd2_journal_abort() error code to record an error in
630  * the journal instead.  On recovery, the journal will complain about
631  * that error until we've noted it down and cleared it.
632  *
633  * If force_ro is set, we unconditionally force the filesystem into an
634  * ABORT|READONLY state, unless the error response on the fs has been set to
635  * panic in which case we take the easy way out and panic immediately. This is
636  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
637  * at a critical moment in log management.
638  */
639 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
640 			      __u32 ino, __u64 block,
641 			      const char *func, unsigned int line)
642 {
643 	journal_t *journal = EXT4_SB(sb)->s_journal;
644 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
645 
646 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
647 	if (test_opt(sb, WARN_ON_ERROR))
648 		WARN_ON_ONCE(1);
649 
650 	if (!continue_fs && !sb_rdonly(sb)) {
651 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
652 		if (journal)
653 			jbd2_journal_abort(journal, -EIO);
654 	}
655 
656 	if (!bdev_read_only(sb->s_bdev)) {
657 		save_error_info(sb, error, ino, block, func, line);
658 		/*
659 		 * In case the fs should keep running, we need to writeout
660 		 * superblock through the journal. Due to lock ordering
661 		 * constraints, it may not be safe to do it right here so we
662 		 * defer superblock flushing to a workqueue.
663 		 */
664 		if (continue_fs)
665 			schedule_work(&EXT4_SB(sb)->s_error_work);
666 		else
667 			ext4_commit_super(sb);
668 	}
669 
670 	if (sb_rdonly(sb) || continue_fs)
671 		return;
672 
673 	/*
674 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
675 	 * could panic during 'reboot -f' as the underlying device got already
676 	 * disabled.
677 	 */
678 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
679 		panic("EXT4-fs (device %s): panic forced after error\n",
680 			sb->s_id);
681 	}
682 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
683 	/*
684 	 * Make sure updated value of ->s_mount_flags will be visible before
685 	 * ->s_flags update
686 	 */
687 	smp_wmb();
688 	sb->s_flags |= SB_RDONLY;
689 }
690 
691 static void flush_stashed_error_work(struct work_struct *work)
692 {
693 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
694 						s_error_work);
695 	journal_t *journal = sbi->s_journal;
696 	handle_t *handle;
697 
698 	/*
699 	 * If the journal is still running, we have to write out superblock
700 	 * through the journal to avoid collisions of other journalled sb
701 	 * updates.
702 	 *
703 	 * We use directly jbd2 functions here to avoid recursing back into
704 	 * ext4 error handling code during handling of previous errors.
705 	 */
706 	if (!sb_rdonly(sbi->s_sb) && journal) {
707 		handle = jbd2_journal_start(journal, 1);
708 		if (IS_ERR(handle))
709 			goto write_directly;
710 		if (jbd2_journal_get_write_access(handle, sbi->s_sbh)) {
711 			jbd2_journal_stop(handle);
712 			goto write_directly;
713 		}
714 		ext4_update_super(sbi->s_sb);
715 		if (jbd2_journal_dirty_metadata(handle, sbi->s_sbh)) {
716 			jbd2_journal_stop(handle);
717 			goto write_directly;
718 		}
719 		jbd2_journal_stop(handle);
720 		return;
721 	}
722 write_directly:
723 	/*
724 	 * Write through journal failed. Write sb directly to get error info
725 	 * out and hope for the best.
726 	 */
727 	ext4_commit_super(sbi->s_sb);
728 }
729 
730 #define ext4_error_ratelimit(sb)					\
731 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
732 			     "EXT4-fs error")
733 
734 void __ext4_error(struct super_block *sb, const char *function,
735 		  unsigned int line, bool force_ro, int error, __u64 block,
736 		  const char *fmt, ...)
737 {
738 	struct va_format vaf;
739 	va_list args;
740 
741 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
742 		return;
743 
744 	trace_ext4_error(sb, function, line);
745 	if (ext4_error_ratelimit(sb)) {
746 		va_start(args, fmt);
747 		vaf.fmt = fmt;
748 		vaf.va = &args;
749 		printk(KERN_CRIT
750 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
751 		       sb->s_id, function, line, current->comm, &vaf);
752 		va_end(args);
753 	}
754 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
755 }
756 
757 void __ext4_error_inode(struct inode *inode, const char *function,
758 			unsigned int line, ext4_fsblk_t block, int error,
759 			const char *fmt, ...)
760 {
761 	va_list args;
762 	struct va_format vaf;
763 
764 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
765 		return;
766 
767 	trace_ext4_error(inode->i_sb, function, line);
768 	if (ext4_error_ratelimit(inode->i_sb)) {
769 		va_start(args, fmt);
770 		vaf.fmt = fmt;
771 		vaf.va = &args;
772 		if (block)
773 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
774 			       "inode #%lu: block %llu: comm %s: %pV\n",
775 			       inode->i_sb->s_id, function, line, inode->i_ino,
776 			       block, current->comm, &vaf);
777 		else
778 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
779 			       "inode #%lu: comm %s: %pV\n",
780 			       inode->i_sb->s_id, function, line, inode->i_ino,
781 			       current->comm, &vaf);
782 		va_end(args);
783 	}
784 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
785 			  function, line);
786 }
787 
788 void __ext4_error_file(struct file *file, const char *function,
789 		       unsigned int line, ext4_fsblk_t block,
790 		       const char *fmt, ...)
791 {
792 	va_list args;
793 	struct va_format vaf;
794 	struct inode *inode = file_inode(file);
795 	char pathname[80], *path;
796 
797 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
798 		return;
799 
800 	trace_ext4_error(inode->i_sb, function, line);
801 	if (ext4_error_ratelimit(inode->i_sb)) {
802 		path = file_path(file, pathname, sizeof(pathname));
803 		if (IS_ERR(path))
804 			path = "(unknown)";
805 		va_start(args, fmt);
806 		vaf.fmt = fmt;
807 		vaf.va = &args;
808 		if (block)
809 			printk(KERN_CRIT
810 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
811 			       "block %llu: comm %s: path %s: %pV\n",
812 			       inode->i_sb->s_id, function, line, inode->i_ino,
813 			       block, current->comm, path, &vaf);
814 		else
815 			printk(KERN_CRIT
816 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
817 			       "comm %s: path %s: %pV\n",
818 			       inode->i_sb->s_id, function, line, inode->i_ino,
819 			       current->comm, path, &vaf);
820 		va_end(args);
821 	}
822 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
823 			  function, line);
824 }
825 
826 const char *ext4_decode_error(struct super_block *sb, int errno,
827 			      char nbuf[16])
828 {
829 	char *errstr = NULL;
830 
831 	switch (errno) {
832 	case -EFSCORRUPTED:
833 		errstr = "Corrupt filesystem";
834 		break;
835 	case -EFSBADCRC:
836 		errstr = "Filesystem failed CRC";
837 		break;
838 	case -EIO:
839 		errstr = "IO failure";
840 		break;
841 	case -ENOMEM:
842 		errstr = "Out of memory";
843 		break;
844 	case -EROFS:
845 		if (!sb || (EXT4_SB(sb)->s_journal &&
846 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
847 			errstr = "Journal has aborted";
848 		else
849 			errstr = "Readonly filesystem";
850 		break;
851 	default:
852 		/* If the caller passed in an extra buffer for unknown
853 		 * errors, textualise them now.  Else we just return
854 		 * NULL. */
855 		if (nbuf) {
856 			/* Check for truncated error codes... */
857 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
858 				errstr = nbuf;
859 		}
860 		break;
861 	}
862 
863 	return errstr;
864 }
865 
866 /* __ext4_std_error decodes expected errors from journaling functions
867  * automatically and invokes the appropriate error response.  */
868 
869 void __ext4_std_error(struct super_block *sb, const char *function,
870 		      unsigned int line, int errno)
871 {
872 	char nbuf[16];
873 	const char *errstr;
874 
875 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
876 		return;
877 
878 	/* Special case: if the error is EROFS, and we're not already
879 	 * inside a transaction, then there's really no point in logging
880 	 * an error. */
881 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
882 		return;
883 
884 	if (ext4_error_ratelimit(sb)) {
885 		errstr = ext4_decode_error(sb, errno, nbuf);
886 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
887 		       sb->s_id, function, line, errstr);
888 	}
889 
890 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
891 }
892 
893 void __ext4_msg(struct super_block *sb,
894 		const char *prefix, const char *fmt, ...)
895 {
896 	struct va_format vaf;
897 	va_list args;
898 
899 	atomic_inc(&EXT4_SB(sb)->s_msg_count);
900 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
901 		return;
902 
903 	va_start(args, fmt);
904 	vaf.fmt = fmt;
905 	vaf.va = &args;
906 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
907 	va_end(args);
908 }
909 
910 static int ext4_warning_ratelimit(struct super_block *sb)
911 {
912 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
913 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
914 			    "EXT4-fs warning");
915 }
916 
917 void __ext4_warning(struct super_block *sb, const char *function,
918 		    unsigned int line, const char *fmt, ...)
919 {
920 	struct va_format vaf;
921 	va_list args;
922 
923 	if (!ext4_warning_ratelimit(sb))
924 		return;
925 
926 	va_start(args, fmt);
927 	vaf.fmt = fmt;
928 	vaf.va = &args;
929 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
930 	       sb->s_id, function, line, &vaf);
931 	va_end(args);
932 }
933 
934 void __ext4_warning_inode(const struct inode *inode, const char *function,
935 			  unsigned int line, const char *fmt, ...)
936 {
937 	struct va_format vaf;
938 	va_list args;
939 
940 	if (!ext4_warning_ratelimit(inode->i_sb))
941 		return;
942 
943 	va_start(args, fmt);
944 	vaf.fmt = fmt;
945 	vaf.va = &args;
946 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
947 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
948 	       function, line, inode->i_ino, current->comm, &vaf);
949 	va_end(args);
950 }
951 
952 void __ext4_grp_locked_error(const char *function, unsigned int line,
953 			     struct super_block *sb, ext4_group_t grp,
954 			     unsigned long ino, ext4_fsblk_t block,
955 			     const char *fmt, ...)
956 __releases(bitlock)
957 __acquires(bitlock)
958 {
959 	struct va_format vaf;
960 	va_list args;
961 
962 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
963 		return;
964 
965 	trace_ext4_error(sb, function, line);
966 	if (ext4_error_ratelimit(sb)) {
967 		va_start(args, fmt);
968 		vaf.fmt = fmt;
969 		vaf.va = &args;
970 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
971 		       sb->s_id, function, line, grp);
972 		if (ino)
973 			printk(KERN_CONT "inode %lu: ", ino);
974 		if (block)
975 			printk(KERN_CONT "block %llu:",
976 			       (unsigned long long) block);
977 		printk(KERN_CONT "%pV\n", &vaf);
978 		va_end(args);
979 	}
980 
981 	if (test_opt(sb, ERRORS_CONT)) {
982 		if (test_opt(sb, WARN_ON_ERROR))
983 			WARN_ON_ONCE(1);
984 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
985 		if (!bdev_read_only(sb->s_bdev)) {
986 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
987 					line);
988 			schedule_work(&EXT4_SB(sb)->s_error_work);
989 		}
990 		return;
991 	}
992 	ext4_unlock_group(sb, grp);
993 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
994 	/*
995 	 * We only get here in the ERRORS_RO case; relocking the group
996 	 * may be dangerous, but nothing bad will happen since the
997 	 * filesystem will have already been marked read/only and the
998 	 * journal has been aborted.  We return 1 as a hint to callers
999 	 * who might what to use the return value from
1000 	 * ext4_grp_locked_error() to distinguish between the
1001 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1002 	 * aggressively from the ext4 function in question, with a
1003 	 * more appropriate error code.
1004 	 */
1005 	ext4_lock_group(sb, grp);
1006 	return;
1007 }
1008 
1009 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1010 				     ext4_group_t group,
1011 				     unsigned int flags)
1012 {
1013 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1014 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1015 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1016 	int ret;
1017 
1018 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1019 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1020 					    &grp->bb_state);
1021 		if (!ret)
1022 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1023 					   grp->bb_free);
1024 	}
1025 
1026 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1027 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1028 					    &grp->bb_state);
1029 		if (!ret && gdp) {
1030 			int count;
1031 
1032 			count = ext4_free_inodes_count(sb, gdp);
1033 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1034 					   count);
1035 		}
1036 	}
1037 }
1038 
1039 void ext4_update_dynamic_rev(struct super_block *sb)
1040 {
1041 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1042 
1043 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1044 		return;
1045 
1046 	ext4_warning(sb,
1047 		     "updating to rev %d because of new feature flag, "
1048 		     "running e2fsck is recommended",
1049 		     EXT4_DYNAMIC_REV);
1050 
1051 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1052 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1053 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1054 	/* leave es->s_feature_*compat flags alone */
1055 	/* es->s_uuid will be set by e2fsck if empty */
1056 
1057 	/*
1058 	 * The rest of the superblock fields should be zero, and if not it
1059 	 * means they are likely already in use, so leave them alone.  We
1060 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1061 	 */
1062 }
1063 
1064 /*
1065  * Open the external journal device
1066  */
1067 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1068 {
1069 	struct block_device *bdev;
1070 
1071 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1072 	if (IS_ERR(bdev))
1073 		goto fail;
1074 	return bdev;
1075 
1076 fail:
1077 	ext4_msg(sb, KERN_ERR,
1078 		 "failed to open journal device unknown-block(%u,%u) %ld",
1079 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1080 	return NULL;
1081 }
1082 
1083 /*
1084  * Release the journal device
1085  */
1086 static void ext4_blkdev_put(struct block_device *bdev)
1087 {
1088 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1089 }
1090 
1091 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1092 {
1093 	struct block_device *bdev;
1094 	bdev = sbi->s_journal_bdev;
1095 	if (bdev) {
1096 		ext4_blkdev_put(bdev);
1097 		sbi->s_journal_bdev = NULL;
1098 	}
1099 }
1100 
1101 static inline struct inode *orphan_list_entry(struct list_head *l)
1102 {
1103 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1104 }
1105 
1106 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1107 {
1108 	struct list_head *l;
1109 
1110 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1111 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1112 
1113 	printk(KERN_ERR "sb_info orphan list:\n");
1114 	list_for_each(l, &sbi->s_orphan) {
1115 		struct inode *inode = orphan_list_entry(l);
1116 		printk(KERN_ERR "  "
1117 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1118 		       inode->i_sb->s_id, inode->i_ino, inode,
1119 		       inode->i_mode, inode->i_nlink,
1120 		       NEXT_ORPHAN(inode));
1121 	}
1122 }
1123 
1124 #ifdef CONFIG_QUOTA
1125 static int ext4_quota_off(struct super_block *sb, int type);
1126 
1127 static inline void ext4_quota_off_umount(struct super_block *sb)
1128 {
1129 	int type;
1130 
1131 	/* Use our quota_off function to clear inode flags etc. */
1132 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1133 		ext4_quota_off(sb, type);
1134 }
1135 
1136 /*
1137  * This is a helper function which is used in the mount/remount
1138  * codepaths (which holds s_umount) to fetch the quota file name.
1139  */
1140 static inline char *get_qf_name(struct super_block *sb,
1141 				struct ext4_sb_info *sbi,
1142 				int type)
1143 {
1144 	return rcu_dereference_protected(sbi->s_qf_names[type],
1145 					 lockdep_is_held(&sb->s_umount));
1146 }
1147 #else
1148 static inline void ext4_quota_off_umount(struct super_block *sb)
1149 {
1150 }
1151 #endif
1152 
1153 static void ext4_put_super(struct super_block *sb)
1154 {
1155 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1156 	struct ext4_super_block *es = sbi->s_es;
1157 	struct buffer_head **group_desc;
1158 	struct flex_groups **flex_groups;
1159 	int aborted = 0;
1160 	int i, err;
1161 
1162 	ext4_unregister_li_request(sb);
1163 	ext4_quota_off_umount(sb);
1164 
1165 	flush_work(&sbi->s_error_work);
1166 	destroy_workqueue(sbi->rsv_conversion_wq);
1167 
1168 	/*
1169 	 * Unregister sysfs before destroying jbd2 journal.
1170 	 * Since we could still access attr_journal_task attribute via sysfs
1171 	 * path which could have sbi->s_journal->j_task as NULL
1172 	 */
1173 	ext4_unregister_sysfs(sb);
1174 
1175 	if (sbi->s_journal) {
1176 		aborted = is_journal_aborted(sbi->s_journal);
1177 		err = jbd2_journal_destroy(sbi->s_journal);
1178 		sbi->s_journal = NULL;
1179 		if ((err < 0) && !aborted) {
1180 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1181 		}
1182 	}
1183 
1184 	ext4_es_unregister_shrinker(sbi);
1185 	del_timer_sync(&sbi->s_err_report);
1186 	ext4_release_system_zone(sb);
1187 	ext4_mb_release(sb);
1188 	ext4_ext_release(sb);
1189 
1190 	if (!sb_rdonly(sb) && !aborted) {
1191 		ext4_clear_feature_journal_needs_recovery(sb);
1192 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1193 	}
1194 	if (!sb_rdonly(sb))
1195 		ext4_commit_super(sb);
1196 
1197 	rcu_read_lock();
1198 	group_desc = rcu_dereference(sbi->s_group_desc);
1199 	for (i = 0; i < sbi->s_gdb_count; i++)
1200 		brelse(group_desc[i]);
1201 	kvfree(group_desc);
1202 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1203 	if (flex_groups) {
1204 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1205 			kvfree(flex_groups[i]);
1206 		kvfree(flex_groups);
1207 	}
1208 	rcu_read_unlock();
1209 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1210 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1211 	percpu_counter_destroy(&sbi->s_dirs_counter);
1212 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1213 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1214 #ifdef CONFIG_QUOTA
1215 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1216 		kfree(get_qf_name(sb, sbi, i));
1217 #endif
1218 
1219 	/* Debugging code just in case the in-memory inode orphan list
1220 	 * isn't empty.  The on-disk one can be non-empty if we've
1221 	 * detected an error and taken the fs readonly, but the
1222 	 * in-memory list had better be clean by this point. */
1223 	if (!list_empty(&sbi->s_orphan))
1224 		dump_orphan_list(sb, sbi);
1225 	ASSERT(list_empty(&sbi->s_orphan));
1226 
1227 	sync_blockdev(sb->s_bdev);
1228 	invalidate_bdev(sb->s_bdev);
1229 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1230 		/*
1231 		 * Invalidate the journal device's buffers.  We don't want them
1232 		 * floating about in memory - the physical journal device may
1233 		 * hotswapped, and it breaks the `ro-after' testing code.
1234 		 */
1235 		sync_blockdev(sbi->s_journal_bdev);
1236 		invalidate_bdev(sbi->s_journal_bdev);
1237 		ext4_blkdev_remove(sbi);
1238 	}
1239 
1240 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1241 	sbi->s_ea_inode_cache = NULL;
1242 
1243 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1244 	sbi->s_ea_block_cache = NULL;
1245 
1246 	if (sbi->s_mmp_tsk)
1247 		kthread_stop(sbi->s_mmp_tsk);
1248 	brelse(sbi->s_sbh);
1249 	sb->s_fs_info = NULL;
1250 	/*
1251 	 * Now that we are completely done shutting down the
1252 	 * superblock, we need to actually destroy the kobject.
1253 	 */
1254 	kobject_put(&sbi->s_kobj);
1255 	wait_for_completion(&sbi->s_kobj_unregister);
1256 	if (sbi->s_chksum_driver)
1257 		crypto_free_shash(sbi->s_chksum_driver);
1258 	kfree(sbi->s_blockgroup_lock);
1259 	fs_put_dax(sbi->s_daxdev);
1260 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1261 #ifdef CONFIG_UNICODE
1262 	utf8_unload(sb->s_encoding);
1263 #endif
1264 	kfree(sbi);
1265 }
1266 
1267 static struct kmem_cache *ext4_inode_cachep;
1268 
1269 /*
1270  * Called inside transaction, so use GFP_NOFS
1271  */
1272 static struct inode *ext4_alloc_inode(struct super_block *sb)
1273 {
1274 	struct ext4_inode_info *ei;
1275 
1276 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1277 	if (!ei)
1278 		return NULL;
1279 
1280 	inode_set_iversion(&ei->vfs_inode, 1);
1281 	spin_lock_init(&ei->i_raw_lock);
1282 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1283 	atomic_set(&ei->i_prealloc_active, 0);
1284 	spin_lock_init(&ei->i_prealloc_lock);
1285 	ext4_es_init_tree(&ei->i_es_tree);
1286 	rwlock_init(&ei->i_es_lock);
1287 	INIT_LIST_HEAD(&ei->i_es_list);
1288 	ei->i_es_all_nr = 0;
1289 	ei->i_es_shk_nr = 0;
1290 	ei->i_es_shrink_lblk = 0;
1291 	ei->i_reserved_data_blocks = 0;
1292 	spin_lock_init(&(ei->i_block_reservation_lock));
1293 	ext4_init_pending_tree(&ei->i_pending_tree);
1294 #ifdef CONFIG_QUOTA
1295 	ei->i_reserved_quota = 0;
1296 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1297 #endif
1298 	ei->jinode = NULL;
1299 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1300 	spin_lock_init(&ei->i_completed_io_lock);
1301 	ei->i_sync_tid = 0;
1302 	ei->i_datasync_tid = 0;
1303 	atomic_set(&ei->i_unwritten, 0);
1304 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1305 	ext4_fc_init_inode(&ei->vfs_inode);
1306 	mutex_init(&ei->i_fc_lock);
1307 	return &ei->vfs_inode;
1308 }
1309 
1310 static int ext4_drop_inode(struct inode *inode)
1311 {
1312 	int drop = generic_drop_inode(inode);
1313 
1314 	if (!drop)
1315 		drop = fscrypt_drop_inode(inode);
1316 
1317 	trace_ext4_drop_inode(inode, drop);
1318 	return drop;
1319 }
1320 
1321 static void ext4_free_in_core_inode(struct inode *inode)
1322 {
1323 	fscrypt_free_inode(inode);
1324 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1325 		pr_warn("%s: inode %ld still in fc list",
1326 			__func__, inode->i_ino);
1327 	}
1328 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1329 }
1330 
1331 static void ext4_destroy_inode(struct inode *inode)
1332 {
1333 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1334 		ext4_msg(inode->i_sb, KERN_ERR,
1335 			 "Inode %lu (%p): orphan list check failed!",
1336 			 inode->i_ino, EXT4_I(inode));
1337 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1338 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1339 				true);
1340 		dump_stack();
1341 	}
1342 }
1343 
1344 static void init_once(void *foo)
1345 {
1346 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1347 
1348 	INIT_LIST_HEAD(&ei->i_orphan);
1349 	init_rwsem(&ei->xattr_sem);
1350 	init_rwsem(&ei->i_data_sem);
1351 	init_rwsem(&ei->i_mmap_sem);
1352 	inode_init_once(&ei->vfs_inode);
1353 	ext4_fc_init_inode(&ei->vfs_inode);
1354 }
1355 
1356 static int __init init_inodecache(void)
1357 {
1358 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1359 				sizeof(struct ext4_inode_info), 0,
1360 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1361 					SLAB_ACCOUNT),
1362 				offsetof(struct ext4_inode_info, i_data),
1363 				sizeof_field(struct ext4_inode_info, i_data),
1364 				init_once);
1365 	if (ext4_inode_cachep == NULL)
1366 		return -ENOMEM;
1367 	return 0;
1368 }
1369 
1370 static void destroy_inodecache(void)
1371 {
1372 	/*
1373 	 * Make sure all delayed rcu free inodes are flushed before we
1374 	 * destroy cache.
1375 	 */
1376 	rcu_barrier();
1377 	kmem_cache_destroy(ext4_inode_cachep);
1378 }
1379 
1380 void ext4_clear_inode(struct inode *inode)
1381 {
1382 	ext4_fc_del(inode);
1383 	invalidate_inode_buffers(inode);
1384 	clear_inode(inode);
1385 	ext4_discard_preallocations(inode, 0);
1386 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1387 	dquot_drop(inode);
1388 	if (EXT4_I(inode)->jinode) {
1389 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1390 					       EXT4_I(inode)->jinode);
1391 		jbd2_free_inode(EXT4_I(inode)->jinode);
1392 		EXT4_I(inode)->jinode = NULL;
1393 	}
1394 	fscrypt_put_encryption_info(inode);
1395 	fsverity_cleanup_inode(inode);
1396 }
1397 
1398 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1399 					u64 ino, u32 generation)
1400 {
1401 	struct inode *inode;
1402 
1403 	/*
1404 	 * Currently we don't know the generation for parent directory, so
1405 	 * a generation of 0 means "accept any"
1406 	 */
1407 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1408 	if (IS_ERR(inode))
1409 		return ERR_CAST(inode);
1410 	if (generation && inode->i_generation != generation) {
1411 		iput(inode);
1412 		return ERR_PTR(-ESTALE);
1413 	}
1414 
1415 	return inode;
1416 }
1417 
1418 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1419 					int fh_len, int fh_type)
1420 {
1421 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1422 				    ext4_nfs_get_inode);
1423 }
1424 
1425 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1426 					int fh_len, int fh_type)
1427 {
1428 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1429 				    ext4_nfs_get_inode);
1430 }
1431 
1432 static int ext4_nfs_commit_metadata(struct inode *inode)
1433 {
1434 	struct writeback_control wbc = {
1435 		.sync_mode = WB_SYNC_ALL
1436 	};
1437 
1438 	trace_ext4_nfs_commit_metadata(inode);
1439 	return ext4_write_inode(inode, &wbc);
1440 }
1441 
1442 /*
1443  * Try to release metadata pages (indirect blocks, directories) which are
1444  * mapped via the block device.  Since these pages could have journal heads
1445  * which would prevent try_to_free_buffers() from freeing them, we must use
1446  * jbd2 layer's try_to_free_buffers() function to release them.
1447  */
1448 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1449 				 gfp_t wait)
1450 {
1451 	journal_t *journal = EXT4_SB(sb)->s_journal;
1452 
1453 	WARN_ON(PageChecked(page));
1454 	if (!page_has_buffers(page))
1455 		return 0;
1456 	if (journal)
1457 		return jbd2_journal_try_to_free_buffers(journal, page);
1458 
1459 	return try_to_free_buffers(page);
1460 }
1461 
1462 #ifdef CONFIG_FS_ENCRYPTION
1463 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1464 {
1465 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1466 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1467 }
1468 
1469 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1470 							void *fs_data)
1471 {
1472 	handle_t *handle = fs_data;
1473 	int res, res2, credits, retries = 0;
1474 
1475 	/*
1476 	 * Encrypting the root directory is not allowed because e2fsck expects
1477 	 * lost+found to exist and be unencrypted, and encrypting the root
1478 	 * directory would imply encrypting the lost+found directory as well as
1479 	 * the filename "lost+found" itself.
1480 	 */
1481 	if (inode->i_ino == EXT4_ROOT_INO)
1482 		return -EPERM;
1483 
1484 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1485 		return -EINVAL;
1486 
1487 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1488 		return -EOPNOTSUPP;
1489 
1490 	res = ext4_convert_inline_data(inode);
1491 	if (res)
1492 		return res;
1493 
1494 	/*
1495 	 * If a journal handle was specified, then the encryption context is
1496 	 * being set on a new inode via inheritance and is part of a larger
1497 	 * transaction to create the inode.  Otherwise the encryption context is
1498 	 * being set on an existing inode in its own transaction.  Only in the
1499 	 * latter case should the "retry on ENOSPC" logic be used.
1500 	 */
1501 
1502 	if (handle) {
1503 		res = ext4_xattr_set_handle(handle, inode,
1504 					    EXT4_XATTR_INDEX_ENCRYPTION,
1505 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1506 					    ctx, len, 0);
1507 		if (!res) {
1508 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1509 			ext4_clear_inode_state(inode,
1510 					EXT4_STATE_MAY_INLINE_DATA);
1511 			/*
1512 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1513 			 * S_DAX may be disabled
1514 			 */
1515 			ext4_set_inode_flags(inode, false);
1516 		}
1517 		return res;
1518 	}
1519 
1520 	res = dquot_initialize(inode);
1521 	if (res)
1522 		return res;
1523 retry:
1524 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1525 				     &credits);
1526 	if (res)
1527 		return res;
1528 
1529 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1530 	if (IS_ERR(handle))
1531 		return PTR_ERR(handle);
1532 
1533 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1534 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1535 				    ctx, len, 0);
1536 	if (!res) {
1537 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1538 		/*
1539 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1540 		 * S_DAX may be disabled
1541 		 */
1542 		ext4_set_inode_flags(inode, false);
1543 		res = ext4_mark_inode_dirty(handle, inode);
1544 		if (res)
1545 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1546 	}
1547 	res2 = ext4_journal_stop(handle);
1548 
1549 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1550 		goto retry;
1551 	if (!res)
1552 		res = res2;
1553 	return res;
1554 }
1555 
1556 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1557 {
1558 	return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1559 }
1560 
1561 static bool ext4_has_stable_inodes(struct super_block *sb)
1562 {
1563 	return ext4_has_feature_stable_inodes(sb);
1564 }
1565 
1566 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1567 				       int *ino_bits_ret, int *lblk_bits_ret)
1568 {
1569 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1570 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1571 }
1572 
1573 static const struct fscrypt_operations ext4_cryptops = {
1574 	.key_prefix		= "ext4:",
1575 	.get_context		= ext4_get_context,
1576 	.set_context		= ext4_set_context,
1577 	.get_dummy_policy	= ext4_get_dummy_policy,
1578 	.empty_dir		= ext4_empty_dir,
1579 	.max_namelen		= EXT4_NAME_LEN,
1580 	.has_stable_inodes	= ext4_has_stable_inodes,
1581 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1582 };
1583 #endif
1584 
1585 #ifdef CONFIG_QUOTA
1586 static const char * const quotatypes[] = INITQFNAMES;
1587 #define QTYPE2NAME(t) (quotatypes[t])
1588 
1589 static int ext4_write_dquot(struct dquot *dquot);
1590 static int ext4_acquire_dquot(struct dquot *dquot);
1591 static int ext4_release_dquot(struct dquot *dquot);
1592 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1593 static int ext4_write_info(struct super_block *sb, int type);
1594 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1595 			 const struct path *path);
1596 static int ext4_quota_on_mount(struct super_block *sb, int type);
1597 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1598 			       size_t len, loff_t off);
1599 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1600 				const char *data, size_t len, loff_t off);
1601 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1602 			     unsigned int flags);
1603 static int ext4_enable_quotas(struct super_block *sb);
1604 
1605 static struct dquot **ext4_get_dquots(struct inode *inode)
1606 {
1607 	return EXT4_I(inode)->i_dquot;
1608 }
1609 
1610 static const struct dquot_operations ext4_quota_operations = {
1611 	.get_reserved_space	= ext4_get_reserved_space,
1612 	.write_dquot		= ext4_write_dquot,
1613 	.acquire_dquot		= ext4_acquire_dquot,
1614 	.release_dquot		= ext4_release_dquot,
1615 	.mark_dirty		= ext4_mark_dquot_dirty,
1616 	.write_info		= ext4_write_info,
1617 	.alloc_dquot		= dquot_alloc,
1618 	.destroy_dquot		= dquot_destroy,
1619 	.get_projid		= ext4_get_projid,
1620 	.get_inode_usage	= ext4_get_inode_usage,
1621 	.get_next_id		= dquot_get_next_id,
1622 };
1623 
1624 static const struct quotactl_ops ext4_qctl_operations = {
1625 	.quota_on	= ext4_quota_on,
1626 	.quota_off	= ext4_quota_off,
1627 	.quota_sync	= dquot_quota_sync,
1628 	.get_state	= dquot_get_state,
1629 	.set_info	= dquot_set_dqinfo,
1630 	.get_dqblk	= dquot_get_dqblk,
1631 	.set_dqblk	= dquot_set_dqblk,
1632 	.get_nextdqblk	= dquot_get_next_dqblk,
1633 };
1634 #endif
1635 
1636 static const struct super_operations ext4_sops = {
1637 	.alloc_inode	= ext4_alloc_inode,
1638 	.free_inode	= ext4_free_in_core_inode,
1639 	.destroy_inode	= ext4_destroy_inode,
1640 	.write_inode	= ext4_write_inode,
1641 	.dirty_inode	= ext4_dirty_inode,
1642 	.drop_inode	= ext4_drop_inode,
1643 	.evict_inode	= ext4_evict_inode,
1644 	.put_super	= ext4_put_super,
1645 	.sync_fs	= ext4_sync_fs,
1646 	.freeze_fs	= ext4_freeze,
1647 	.unfreeze_fs	= ext4_unfreeze,
1648 	.statfs		= ext4_statfs,
1649 	.remount_fs	= ext4_remount,
1650 	.show_options	= ext4_show_options,
1651 #ifdef CONFIG_QUOTA
1652 	.quota_read	= ext4_quota_read,
1653 	.quota_write	= ext4_quota_write,
1654 	.get_dquots	= ext4_get_dquots,
1655 #endif
1656 	.bdev_try_to_free_page = bdev_try_to_free_page,
1657 };
1658 
1659 static const struct export_operations ext4_export_ops = {
1660 	.fh_to_dentry = ext4_fh_to_dentry,
1661 	.fh_to_parent = ext4_fh_to_parent,
1662 	.get_parent = ext4_get_parent,
1663 	.commit_metadata = ext4_nfs_commit_metadata,
1664 };
1665 
1666 enum {
1667 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1668 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1669 	Opt_nouid32, Opt_debug, Opt_removed,
1670 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1671 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1672 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1673 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1674 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1675 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1676 	Opt_inlinecrypt,
1677 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1678 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1679 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1680 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1681 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1682 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1683 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1684 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1685 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1686 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1687 	Opt_dioread_nolock, Opt_dioread_lock,
1688 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1689 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1690 	Opt_prefetch_block_bitmaps,
1691 #ifdef CONFIG_EXT4_DEBUG
1692 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1693 #endif
1694 };
1695 
1696 static const match_table_t tokens = {
1697 	{Opt_bsd_df, "bsddf"},
1698 	{Opt_minix_df, "minixdf"},
1699 	{Opt_grpid, "grpid"},
1700 	{Opt_grpid, "bsdgroups"},
1701 	{Opt_nogrpid, "nogrpid"},
1702 	{Opt_nogrpid, "sysvgroups"},
1703 	{Opt_resgid, "resgid=%u"},
1704 	{Opt_resuid, "resuid=%u"},
1705 	{Opt_sb, "sb=%u"},
1706 	{Opt_err_cont, "errors=continue"},
1707 	{Opt_err_panic, "errors=panic"},
1708 	{Opt_err_ro, "errors=remount-ro"},
1709 	{Opt_nouid32, "nouid32"},
1710 	{Opt_debug, "debug"},
1711 	{Opt_removed, "oldalloc"},
1712 	{Opt_removed, "orlov"},
1713 	{Opt_user_xattr, "user_xattr"},
1714 	{Opt_nouser_xattr, "nouser_xattr"},
1715 	{Opt_acl, "acl"},
1716 	{Opt_noacl, "noacl"},
1717 	{Opt_noload, "norecovery"},
1718 	{Opt_noload, "noload"},
1719 	{Opt_removed, "nobh"},
1720 	{Opt_removed, "bh"},
1721 	{Opt_commit, "commit=%u"},
1722 	{Opt_min_batch_time, "min_batch_time=%u"},
1723 	{Opt_max_batch_time, "max_batch_time=%u"},
1724 	{Opt_journal_dev, "journal_dev=%u"},
1725 	{Opt_journal_path, "journal_path=%s"},
1726 	{Opt_journal_checksum, "journal_checksum"},
1727 	{Opt_nojournal_checksum, "nojournal_checksum"},
1728 	{Opt_journal_async_commit, "journal_async_commit"},
1729 	{Opt_abort, "abort"},
1730 	{Opt_data_journal, "data=journal"},
1731 	{Opt_data_ordered, "data=ordered"},
1732 	{Opt_data_writeback, "data=writeback"},
1733 	{Opt_data_err_abort, "data_err=abort"},
1734 	{Opt_data_err_ignore, "data_err=ignore"},
1735 	{Opt_offusrjquota, "usrjquota="},
1736 	{Opt_usrjquota, "usrjquota=%s"},
1737 	{Opt_offgrpjquota, "grpjquota="},
1738 	{Opt_grpjquota, "grpjquota=%s"},
1739 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1740 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1741 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1742 	{Opt_grpquota, "grpquota"},
1743 	{Opt_noquota, "noquota"},
1744 	{Opt_quota, "quota"},
1745 	{Opt_usrquota, "usrquota"},
1746 	{Opt_prjquota, "prjquota"},
1747 	{Opt_barrier, "barrier=%u"},
1748 	{Opt_barrier, "barrier"},
1749 	{Opt_nobarrier, "nobarrier"},
1750 	{Opt_i_version, "i_version"},
1751 	{Opt_dax, "dax"},
1752 	{Opt_dax_always, "dax=always"},
1753 	{Opt_dax_inode, "dax=inode"},
1754 	{Opt_dax_never, "dax=never"},
1755 	{Opt_stripe, "stripe=%u"},
1756 	{Opt_delalloc, "delalloc"},
1757 	{Opt_warn_on_error, "warn_on_error"},
1758 	{Opt_nowarn_on_error, "nowarn_on_error"},
1759 	{Opt_lazytime, "lazytime"},
1760 	{Opt_nolazytime, "nolazytime"},
1761 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1762 	{Opt_nodelalloc, "nodelalloc"},
1763 	{Opt_removed, "mblk_io_submit"},
1764 	{Opt_removed, "nomblk_io_submit"},
1765 	{Opt_block_validity, "block_validity"},
1766 	{Opt_noblock_validity, "noblock_validity"},
1767 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1768 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1769 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1770 	{Opt_auto_da_alloc, "auto_da_alloc"},
1771 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1772 	{Opt_dioread_nolock, "dioread_nolock"},
1773 	{Opt_dioread_lock, "nodioread_nolock"},
1774 	{Opt_dioread_lock, "dioread_lock"},
1775 	{Opt_discard, "discard"},
1776 	{Opt_nodiscard, "nodiscard"},
1777 	{Opt_init_itable, "init_itable=%u"},
1778 	{Opt_init_itable, "init_itable"},
1779 	{Opt_noinit_itable, "noinit_itable"},
1780 #ifdef CONFIG_EXT4_DEBUG
1781 	{Opt_fc_debug_force, "fc_debug_force"},
1782 	{Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
1783 #endif
1784 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1785 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1786 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1787 	{Opt_inlinecrypt, "inlinecrypt"},
1788 	{Opt_nombcache, "nombcache"},
1789 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1790 	{Opt_prefetch_block_bitmaps, "prefetch_block_bitmaps"},
1791 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1792 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1793 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1794 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1795 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1796 	{Opt_err, NULL},
1797 };
1798 
1799 static ext4_fsblk_t get_sb_block(void **data)
1800 {
1801 	ext4_fsblk_t	sb_block;
1802 	char		*options = (char *) *data;
1803 
1804 	if (!options || strncmp(options, "sb=", 3) != 0)
1805 		return 1;	/* Default location */
1806 
1807 	options += 3;
1808 	/* TODO: use simple_strtoll with >32bit ext4 */
1809 	sb_block = simple_strtoul(options, &options, 0);
1810 	if (*options && *options != ',') {
1811 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1812 		       (char *) *data);
1813 		return 1;
1814 	}
1815 	if (*options == ',')
1816 		options++;
1817 	*data = (void *) options;
1818 
1819 	return sb_block;
1820 }
1821 
1822 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1823 static const char deprecated_msg[] =
1824 	"Mount option \"%s\" will be removed by %s\n"
1825 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1826 
1827 #ifdef CONFIG_QUOTA
1828 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1829 {
1830 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1831 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1832 	int ret = -1;
1833 
1834 	if (sb_any_quota_loaded(sb) && !old_qname) {
1835 		ext4_msg(sb, KERN_ERR,
1836 			"Cannot change journaled "
1837 			"quota options when quota turned on");
1838 		return -1;
1839 	}
1840 	if (ext4_has_feature_quota(sb)) {
1841 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1842 			 "ignored when QUOTA feature is enabled");
1843 		return 1;
1844 	}
1845 	qname = match_strdup(args);
1846 	if (!qname) {
1847 		ext4_msg(sb, KERN_ERR,
1848 			"Not enough memory for storing quotafile name");
1849 		return -1;
1850 	}
1851 	if (old_qname) {
1852 		if (strcmp(old_qname, qname) == 0)
1853 			ret = 1;
1854 		else
1855 			ext4_msg(sb, KERN_ERR,
1856 				 "%s quota file already specified",
1857 				 QTYPE2NAME(qtype));
1858 		goto errout;
1859 	}
1860 	if (strchr(qname, '/')) {
1861 		ext4_msg(sb, KERN_ERR,
1862 			"quotafile must be on filesystem root");
1863 		goto errout;
1864 	}
1865 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1866 	set_opt(sb, QUOTA);
1867 	return 1;
1868 errout:
1869 	kfree(qname);
1870 	return ret;
1871 }
1872 
1873 static int clear_qf_name(struct super_block *sb, int qtype)
1874 {
1875 
1876 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1877 	char *old_qname = get_qf_name(sb, sbi, qtype);
1878 
1879 	if (sb_any_quota_loaded(sb) && old_qname) {
1880 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1881 			" when quota turned on");
1882 		return -1;
1883 	}
1884 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1885 	synchronize_rcu();
1886 	kfree(old_qname);
1887 	return 1;
1888 }
1889 #endif
1890 
1891 #define MOPT_SET	0x0001
1892 #define MOPT_CLEAR	0x0002
1893 #define MOPT_NOSUPPORT	0x0004
1894 #define MOPT_EXPLICIT	0x0008
1895 #define MOPT_CLEAR_ERR	0x0010
1896 #define MOPT_GTE0	0x0020
1897 #ifdef CONFIG_QUOTA
1898 #define MOPT_Q		0
1899 #define MOPT_QFMT	0x0040
1900 #else
1901 #define MOPT_Q		MOPT_NOSUPPORT
1902 #define MOPT_QFMT	MOPT_NOSUPPORT
1903 #endif
1904 #define MOPT_DATAJ	0x0080
1905 #define MOPT_NO_EXT2	0x0100
1906 #define MOPT_NO_EXT3	0x0200
1907 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1908 #define MOPT_STRING	0x0400
1909 #define MOPT_SKIP	0x0800
1910 #define	MOPT_2		0x1000
1911 
1912 static const struct mount_opts {
1913 	int	token;
1914 	int	mount_opt;
1915 	int	flags;
1916 } ext4_mount_opts[] = {
1917 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1918 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1919 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1920 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1921 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1922 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1923 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1924 	 MOPT_EXT4_ONLY | MOPT_SET},
1925 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1926 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1927 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1928 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1929 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1930 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1931 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1932 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1933 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1934 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1935 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1936 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1937 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1938 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1939 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1940 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1941 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1942 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1943 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1944 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1945 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1946 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1947 	 MOPT_NO_EXT2},
1948 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1949 	 MOPT_NO_EXT2},
1950 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1951 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1952 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1953 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1954 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1955 	{Opt_commit, 0, MOPT_GTE0},
1956 	{Opt_max_batch_time, 0, MOPT_GTE0},
1957 	{Opt_min_batch_time, 0, MOPT_GTE0},
1958 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1959 	{Opt_init_itable, 0, MOPT_GTE0},
1960 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1961 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1962 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1963 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1964 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1965 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1966 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1967 	{Opt_stripe, 0, MOPT_GTE0},
1968 	{Opt_resuid, 0, MOPT_GTE0},
1969 	{Opt_resgid, 0, MOPT_GTE0},
1970 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1971 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1972 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1973 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1974 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1975 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1976 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1977 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1978 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1979 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1980 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1981 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1982 #else
1983 	{Opt_acl, 0, MOPT_NOSUPPORT},
1984 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1985 #endif
1986 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1987 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1988 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1989 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1990 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1991 							MOPT_SET | MOPT_Q},
1992 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1993 							MOPT_SET | MOPT_Q},
1994 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1995 							MOPT_SET | MOPT_Q},
1996 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1997 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1998 							MOPT_CLEAR | MOPT_Q},
1999 	{Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
2000 	{Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
2001 	{Opt_offusrjquota, 0, MOPT_Q},
2002 	{Opt_offgrpjquota, 0, MOPT_Q},
2003 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
2004 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
2005 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
2006 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
2007 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
2008 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
2009 	{Opt_prefetch_block_bitmaps, EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS,
2010 	 MOPT_SET},
2011 #ifdef CONFIG_EXT4_DEBUG
2012 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2013 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
2014 	{Opt_fc_debug_max_replay, 0, MOPT_GTE0},
2015 #endif
2016 	{Opt_err, 0, 0}
2017 };
2018 
2019 #ifdef CONFIG_UNICODE
2020 static const struct ext4_sb_encodings {
2021 	__u16 magic;
2022 	char *name;
2023 	char *version;
2024 } ext4_sb_encoding_map[] = {
2025 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
2026 };
2027 
2028 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
2029 				 const struct ext4_sb_encodings **encoding,
2030 				 __u16 *flags)
2031 {
2032 	__u16 magic = le16_to_cpu(es->s_encoding);
2033 	int i;
2034 
2035 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
2036 		if (magic == ext4_sb_encoding_map[i].magic)
2037 			break;
2038 
2039 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
2040 		return -EINVAL;
2041 
2042 	*encoding = &ext4_sb_encoding_map[i];
2043 	*flags = le16_to_cpu(es->s_encoding_flags);
2044 
2045 	return 0;
2046 }
2047 #endif
2048 
2049 static int ext4_set_test_dummy_encryption(struct super_block *sb,
2050 					  const char *opt,
2051 					  const substring_t *arg,
2052 					  bool is_remount)
2053 {
2054 #ifdef CONFIG_FS_ENCRYPTION
2055 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2056 	int err;
2057 
2058 	/*
2059 	 * This mount option is just for testing, and it's not worthwhile to
2060 	 * implement the extra complexity (e.g. RCU protection) that would be
2061 	 * needed to allow it to be set or changed during remount.  We do allow
2062 	 * it to be specified during remount, but only if there is no change.
2063 	 */
2064 	if (is_remount && !sbi->s_dummy_enc_policy.policy) {
2065 		ext4_msg(sb, KERN_WARNING,
2066 			 "Can't set test_dummy_encryption on remount");
2067 		return -1;
2068 	}
2069 	err = fscrypt_set_test_dummy_encryption(sb, arg->from,
2070 						&sbi->s_dummy_enc_policy);
2071 	if (err) {
2072 		if (err == -EEXIST)
2073 			ext4_msg(sb, KERN_WARNING,
2074 				 "Can't change test_dummy_encryption on remount");
2075 		else if (err == -EINVAL)
2076 			ext4_msg(sb, KERN_WARNING,
2077 				 "Value of option \"%s\" is unrecognized", opt);
2078 		else
2079 			ext4_msg(sb, KERN_WARNING,
2080 				 "Error processing option \"%s\" [%d]",
2081 				 opt, err);
2082 		return -1;
2083 	}
2084 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2085 #else
2086 	ext4_msg(sb, KERN_WARNING,
2087 		 "Test dummy encryption mount option ignored");
2088 #endif
2089 	return 1;
2090 }
2091 
2092 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
2093 			    substring_t *args, unsigned long *journal_devnum,
2094 			    unsigned int *journal_ioprio, int is_remount)
2095 {
2096 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2097 	const struct mount_opts *m;
2098 	kuid_t uid;
2099 	kgid_t gid;
2100 	int arg = 0;
2101 
2102 #ifdef CONFIG_QUOTA
2103 	if (token == Opt_usrjquota)
2104 		return set_qf_name(sb, USRQUOTA, &args[0]);
2105 	else if (token == Opt_grpjquota)
2106 		return set_qf_name(sb, GRPQUOTA, &args[0]);
2107 	else if (token == Opt_offusrjquota)
2108 		return clear_qf_name(sb, USRQUOTA);
2109 	else if (token == Opt_offgrpjquota)
2110 		return clear_qf_name(sb, GRPQUOTA);
2111 #endif
2112 	switch (token) {
2113 	case Opt_noacl:
2114 	case Opt_nouser_xattr:
2115 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
2116 		break;
2117 	case Opt_sb:
2118 		return 1;	/* handled by get_sb_block() */
2119 	case Opt_removed:
2120 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
2121 		return 1;
2122 	case Opt_abort:
2123 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
2124 		return 1;
2125 	case Opt_i_version:
2126 		sb->s_flags |= SB_I_VERSION;
2127 		return 1;
2128 	case Opt_lazytime:
2129 		sb->s_flags |= SB_LAZYTIME;
2130 		return 1;
2131 	case Opt_nolazytime:
2132 		sb->s_flags &= ~SB_LAZYTIME;
2133 		return 1;
2134 	case Opt_inlinecrypt:
2135 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2136 		sb->s_flags |= SB_INLINECRYPT;
2137 #else
2138 		ext4_msg(sb, KERN_ERR, "inline encryption not supported");
2139 #endif
2140 		return 1;
2141 	}
2142 
2143 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2144 		if (token == m->token)
2145 			break;
2146 
2147 	if (m->token == Opt_err) {
2148 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
2149 			 "or missing value", opt);
2150 		return -1;
2151 	}
2152 
2153 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2154 		ext4_msg(sb, KERN_ERR,
2155 			 "Mount option \"%s\" incompatible with ext2", opt);
2156 		return -1;
2157 	}
2158 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2159 		ext4_msg(sb, KERN_ERR,
2160 			 "Mount option \"%s\" incompatible with ext3", opt);
2161 		return -1;
2162 	}
2163 
2164 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
2165 		return -1;
2166 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
2167 		return -1;
2168 	if (m->flags & MOPT_EXPLICIT) {
2169 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2170 			set_opt2(sb, EXPLICIT_DELALLOC);
2171 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2172 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
2173 		} else
2174 			return -1;
2175 	}
2176 	if (m->flags & MOPT_CLEAR_ERR)
2177 		clear_opt(sb, ERRORS_MASK);
2178 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
2179 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
2180 			 "options when quota turned on");
2181 		return -1;
2182 	}
2183 
2184 	if (m->flags & MOPT_NOSUPPORT) {
2185 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
2186 	} else if (token == Opt_commit) {
2187 		if (arg == 0)
2188 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
2189 		else if (arg > INT_MAX / HZ) {
2190 			ext4_msg(sb, KERN_ERR,
2191 				 "Invalid commit interval %d, "
2192 				 "must be smaller than %d",
2193 				 arg, INT_MAX / HZ);
2194 			return -1;
2195 		}
2196 		sbi->s_commit_interval = HZ * arg;
2197 	} else if (token == Opt_debug_want_extra_isize) {
2198 		if ((arg & 1) ||
2199 		    (arg < 4) ||
2200 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2201 			ext4_msg(sb, KERN_ERR,
2202 				 "Invalid want_extra_isize %d", arg);
2203 			return -1;
2204 		}
2205 		sbi->s_want_extra_isize = arg;
2206 	} else if (token == Opt_max_batch_time) {
2207 		sbi->s_max_batch_time = arg;
2208 	} else if (token == Opt_min_batch_time) {
2209 		sbi->s_min_batch_time = arg;
2210 	} else if (token == Opt_inode_readahead_blks) {
2211 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2212 			ext4_msg(sb, KERN_ERR,
2213 				 "EXT4-fs: inode_readahead_blks must be "
2214 				 "0 or a power of 2 smaller than 2^31");
2215 			return -1;
2216 		}
2217 		sbi->s_inode_readahead_blks = arg;
2218 	} else if (token == Opt_init_itable) {
2219 		set_opt(sb, INIT_INODE_TABLE);
2220 		if (!args->from)
2221 			arg = EXT4_DEF_LI_WAIT_MULT;
2222 		sbi->s_li_wait_mult = arg;
2223 	} else if (token == Opt_max_dir_size_kb) {
2224 		sbi->s_max_dir_size_kb = arg;
2225 #ifdef CONFIG_EXT4_DEBUG
2226 	} else if (token == Opt_fc_debug_max_replay) {
2227 		sbi->s_fc_debug_max_replay = arg;
2228 #endif
2229 	} else if (token == Opt_stripe) {
2230 		sbi->s_stripe = arg;
2231 	} else if (token == Opt_resuid) {
2232 		uid = make_kuid(current_user_ns(), arg);
2233 		if (!uid_valid(uid)) {
2234 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2235 			return -1;
2236 		}
2237 		sbi->s_resuid = uid;
2238 	} else if (token == Opt_resgid) {
2239 		gid = make_kgid(current_user_ns(), arg);
2240 		if (!gid_valid(gid)) {
2241 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2242 			return -1;
2243 		}
2244 		sbi->s_resgid = gid;
2245 	} else if (token == Opt_journal_dev) {
2246 		if (is_remount) {
2247 			ext4_msg(sb, KERN_ERR,
2248 				 "Cannot specify journal on remount");
2249 			return -1;
2250 		}
2251 		*journal_devnum = arg;
2252 	} else if (token == Opt_journal_path) {
2253 		char *journal_path;
2254 		struct inode *journal_inode;
2255 		struct path path;
2256 		int error;
2257 
2258 		if (is_remount) {
2259 			ext4_msg(sb, KERN_ERR,
2260 				 "Cannot specify journal on remount");
2261 			return -1;
2262 		}
2263 		journal_path = match_strdup(&args[0]);
2264 		if (!journal_path) {
2265 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2266 				"journal device string");
2267 			return -1;
2268 		}
2269 
2270 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2271 		if (error) {
2272 			ext4_msg(sb, KERN_ERR, "error: could not find "
2273 				"journal device path: error %d", error);
2274 			kfree(journal_path);
2275 			return -1;
2276 		}
2277 
2278 		journal_inode = d_inode(path.dentry);
2279 		if (!S_ISBLK(journal_inode->i_mode)) {
2280 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2281 				"is not a block device", journal_path);
2282 			path_put(&path);
2283 			kfree(journal_path);
2284 			return -1;
2285 		}
2286 
2287 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2288 		path_put(&path);
2289 		kfree(journal_path);
2290 	} else if (token == Opt_journal_ioprio) {
2291 		if (arg > 7) {
2292 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2293 				 " (must be 0-7)");
2294 			return -1;
2295 		}
2296 		*journal_ioprio =
2297 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2298 	} else if (token == Opt_test_dummy_encryption) {
2299 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2300 						      is_remount);
2301 	} else if (m->flags & MOPT_DATAJ) {
2302 		if (is_remount) {
2303 			if (!sbi->s_journal)
2304 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2305 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2306 				ext4_msg(sb, KERN_ERR,
2307 					 "Cannot change data mode on remount");
2308 				return -1;
2309 			}
2310 		} else {
2311 			clear_opt(sb, DATA_FLAGS);
2312 			sbi->s_mount_opt |= m->mount_opt;
2313 		}
2314 #ifdef CONFIG_QUOTA
2315 	} else if (m->flags & MOPT_QFMT) {
2316 		if (sb_any_quota_loaded(sb) &&
2317 		    sbi->s_jquota_fmt != m->mount_opt) {
2318 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2319 				 "quota options when quota turned on");
2320 			return -1;
2321 		}
2322 		if (ext4_has_feature_quota(sb)) {
2323 			ext4_msg(sb, KERN_INFO,
2324 				 "Quota format mount options ignored "
2325 				 "when QUOTA feature is enabled");
2326 			return 1;
2327 		}
2328 		sbi->s_jquota_fmt = m->mount_opt;
2329 #endif
2330 	} else if (token == Opt_dax || token == Opt_dax_always ||
2331 		   token == Opt_dax_inode || token == Opt_dax_never) {
2332 #ifdef CONFIG_FS_DAX
2333 		switch (token) {
2334 		case Opt_dax:
2335 		case Opt_dax_always:
2336 			if (is_remount &&
2337 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2338 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2339 			fail_dax_change_remount:
2340 				ext4_msg(sb, KERN_ERR, "can't change "
2341 					 "dax mount option while remounting");
2342 				return -1;
2343 			}
2344 			if (is_remount &&
2345 			    (test_opt(sb, DATA_FLAGS) ==
2346 			     EXT4_MOUNT_JOURNAL_DATA)) {
2347 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2348 					     "both data=journal and dax");
2349 				    return -1;
2350 			}
2351 			ext4_msg(sb, KERN_WARNING,
2352 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2353 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2354 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2355 			break;
2356 		case Opt_dax_never:
2357 			if (is_remount &&
2358 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2359 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2360 				goto fail_dax_change_remount;
2361 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2362 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2363 			break;
2364 		case Opt_dax_inode:
2365 			if (is_remount &&
2366 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2367 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2368 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2369 				goto fail_dax_change_remount;
2370 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2371 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2372 			/* Strictly for printing options */
2373 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2374 			break;
2375 		}
2376 #else
2377 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2378 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2379 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2380 		return -1;
2381 #endif
2382 	} else if (token == Opt_data_err_abort) {
2383 		sbi->s_mount_opt |= m->mount_opt;
2384 	} else if (token == Opt_data_err_ignore) {
2385 		sbi->s_mount_opt &= ~m->mount_opt;
2386 	} else {
2387 		if (!args->from)
2388 			arg = 1;
2389 		if (m->flags & MOPT_CLEAR)
2390 			arg = !arg;
2391 		else if (unlikely(!(m->flags & MOPT_SET))) {
2392 			ext4_msg(sb, KERN_WARNING,
2393 				 "buggy handling of option %s", opt);
2394 			WARN_ON(1);
2395 			return -1;
2396 		}
2397 		if (m->flags & MOPT_2) {
2398 			if (arg != 0)
2399 				sbi->s_mount_opt2 |= m->mount_opt;
2400 			else
2401 				sbi->s_mount_opt2 &= ~m->mount_opt;
2402 		} else {
2403 			if (arg != 0)
2404 				sbi->s_mount_opt |= m->mount_opt;
2405 			else
2406 				sbi->s_mount_opt &= ~m->mount_opt;
2407 		}
2408 	}
2409 	return 1;
2410 }
2411 
2412 static int parse_options(char *options, struct super_block *sb,
2413 			 unsigned long *journal_devnum,
2414 			 unsigned int *journal_ioprio,
2415 			 int is_remount)
2416 {
2417 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2418 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2419 	substring_t args[MAX_OPT_ARGS];
2420 	int token;
2421 
2422 	if (!options)
2423 		return 1;
2424 
2425 	while ((p = strsep(&options, ",")) != NULL) {
2426 		if (!*p)
2427 			continue;
2428 		/*
2429 		 * Initialize args struct so we know whether arg was
2430 		 * found; some options take optional arguments.
2431 		 */
2432 		args[0].to = args[0].from = NULL;
2433 		token = match_token(p, tokens, args);
2434 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2435 				     journal_ioprio, is_remount) < 0)
2436 			return 0;
2437 	}
2438 #ifdef CONFIG_QUOTA
2439 	/*
2440 	 * We do the test below only for project quotas. 'usrquota' and
2441 	 * 'grpquota' mount options are allowed even without quota feature
2442 	 * to support legacy quotas in quota files.
2443 	 */
2444 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2445 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2446 			 "Cannot enable project quota enforcement.");
2447 		return 0;
2448 	}
2449 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2450 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2451 	if (usr_qf_name || grp_qf_name) {
2452 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2453 			clear_opt(sb, USRQUOTA);
2454 
2455 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2456 			clear_opt(sb, GRPQUOTA);
2457 
2458 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2459 			ext4_msg(sb, KERN_ERR, "old and new quota "
2460 					"format mixing");
2461 			return 0;
2462 		}
2463 
2464 		if (!sbi->s_jquota_fmt) {
2465 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2466 					"not specified");
2467 			return 0;
2468 		}
2469 	}
2470 #endif
2471 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2472 		int blocksize =
2473 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2474 		if (blocksize < PAGE_SIZE)
2475 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2476 				 "experimental mount option 'dioread_nolock' "
2477 				 "for blocksize < PAGE_SIZE");
2478 	}
2479 	return 1;
2480 }
2481 
2482 static inline void ext4_show_quota_options(struct seq_file *seq,
2483 					   struct super_block *sb)
2484 {
2485 #if defined(CONFIG_QUOTA)
2486 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2487 	char *usr_qf_name, *grp_qf_name;
2488 
2489 	if (sbi->s_jquota_fmt) {
2490 		char *fmtname = "";
2491 
2492 		switch (sbi->s_jquota_fmt) {
2493 		case QFMT_VFS_OLD:
2494 			fmtname = "vfsold";
2495 			break;
2496 		case QFMT_VFS_V0:
2497 			fmtname = "vfsv0";
2498 			break;
2499 		case QFMT_VFS_V1:
2500 			fmtname = "vfsv1";
2501 			break;
2502 		}
2503 		seq_printf(seq, ",jqfmt=%s", fmtname);
2504 	}
2505 
2506 	rcu_read_lock();
2507 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2508 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2509 	if (usr_qf_name)
2510 		seq_show_option(seq, "usrjquota", usr_qf_name);
2511 	if (grp_qf_name)
2512 		seq_show_option(seq, "grpjquota", grp_qf_name);
2513 	rcu_read_unlock();
2514 #endif
2515 }
2516 
2517 static const char *token2str(int token)
2518 {
2519 	const struct match_token *t;
2520 
2521 	for (t = tokens; t->token != Opt_err; t++)
2522 		if (t->token == token && !strchr(t->pattern, '='))
2523 			break;
2524 	return t->pattern;
2525 }
2526 
2527 /*
2528  * Show an option if
2529  *  - it's set to a non-default value OR
2530  *  - if the per-sb default is different from the global default
2531  */
2532 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2533 			      int nodefs)
2534 {
2535 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2536 	struct ext4_super_block *es = sbi->s_es;
2537 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2538 	const struct mount_opts *m;
2539 	char sep = nodefs ? '\n' : ',';
2540 
2541 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2542 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2543 
2544 	if (sbi->s_sb_block != 1)
2545 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2546 
2547 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2548 		int want_set = m->flags & MOPT_SET;
2549 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2550 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2551 			continue;
2552 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2553 			continue; /* skip if same as the default */
2554 		if ((want_set &&
2555 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2556 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2557 			continue; /* select Opt_noFoo vs Opt_Foo */
2558 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2559 	}
2560 
2561 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2562 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2563 		SEQ_OPTS_PRINT("resuid=%u",
2564 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2565 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2566 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2567 		SEQ_OPTS_PRINT("resgid=%u",
2568 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2569 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2570 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2571 		SEQ_OPTS_PUTS("errors=remount-ro");
2572 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2573 		SEQ_OPTS_PUTS("errors=continue");
2574 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2575 		SEQ_OPTS_PUTS("errors=panic");
2576 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2577 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2578 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2579 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2580 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2581 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2582 	if (sb->s_flags & SB_I_VERSION)
2583 		SEQ_OPTS_PUTS("i_version");
2584 	if (nodefs || sbi->s_stripe)
2585 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2586 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2587 			(sbi->s_mount_opt ^ def_mount_opt)) {
2588 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2589 			SEQ_OPTS_PUTS("data=journal");
2590 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2591 			SEQ_OPTS_PUTS("data=ordered");
2592 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2593 			SEQ_OPTS_PUTS("data=writeback");
2594 	}
2595 	if (nodefs ||
2596 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2597 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2598 			       sbi->s_inode_readahead_blks);
2599 
2600 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2601 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2602 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2603 	if (nodefs || sbi->s_max_dir_size_kb)
2604 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2605 	if (test_opt(sb, DATA_ERR_ABORT))
2606 		SEQ_OPTS_PUTS("data_err=abort");
2607 
2608 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2609 
2610 	if (sb->s_flags & SB_INLINECRYPT)
2611 		SEQ_OPTS_PUTS("inlinecrypt");
2612 
2613 	if (test_opt(sb, DAX_ALWAYS)) {
2614 		if (IS_EXT2_SB(sb))
2615 			SEQ_OPTS_PUTS("dax");
2616 		else
2617 			SEQ_OPTS_PUTS("dax=always");
2618 	} else if (test_opt2(sb, DAX_NEVER)) {
2619 		SEQ_OPTS_PUTS("dax=never");
2620 	} else if (test_opt2(sb, DAX_INODE)) {
2621 		SEQ_OPTS_PUTS("dax=inode");
2622 	}
2623 	ext4_show_quota_options(seq, sb);
2624 	return 0;
2625 }
2626 
2627 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2628 {
2629 	return _ext4_show_options(seq, root->d_sb, 0);
2630 }
2631 
2632 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2633 {
2634 	struct super_block *sb = seq->private;
2635 	int rc;
2636 
2637 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2638 	rc = _ext4_show_options(seq, sb, 1);
2639 	seq_puts(seq, "\n");
2640 	return rc;
2641 }
2642 
2643 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2644 			    int read_only)
2645 {
2646 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2647 	int err = 0;
2648 
2649 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2650 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2651 			 "forcing read-only mode");
2652 		err = -EROFS;
2653 		goto done;
2654 	}
2655 	if (read_only)
2656 		goto done;
2657 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2658 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2659 			 "running e2fsck is recommended");
2660 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2661 		ext4_msg(sb, KERN_WARNING,
2662 			 "warning: mounting fs with errors, "
2663 			 "running e2fsck is recommended");
2664 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2665 		 le16_to_cpu(es->s_mnt_count) >=
2666 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2667 		ext4_msg(sb, KERN_WARNING,
2668 			 "warning: maximal mount count reached, "
2669 			 "running e2fsck is recommended");
2670 	else if (le32_to_cpu(es->s_checkinterval) &&
2671 		 (ext4_get_tstamp(es, s_lastcheck) +
2672 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2673 		ext4_msg(sb, KERN_WARNING,
2674 			 "warning: checktime reached, "
2675 			 "running e2fsck is recommended");
2676 	if (!sbi->s_journal)
2677 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2678 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2679 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2680 	le16_add_cpu(&es->s_mnt_count, 1);
2681 	ext4_update_tstamp(es, s_mtime);
2682 	if (sbi->s_journal)
2683 		ext4_set_feature_journal_needs_recovery(sb);
2684 
2685 	err = ext4_commit_super(sb);
2686 done:
2687 	if (test_opt(sb, DEBUG))
2688 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2689 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2690 			sb->s_blocksize,
2691 			sbi->s_groups_count,
2692 			EXT4_BLOCKS_PER_GROUP(sb),
2693 			EXT4_INODES_PER_GROUP(sb),
2694 			sbi->s_mount_opt, sbi->s_mount_opt2);
2695 
2696 	cleancache_init_fs(sb);
2697 	return err;
2698 }
2699 
2700 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2701 {
2702 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2703 	struct flex_groups **old_groups, **new_groups;
2704 	int size, i, j;
2705 
2706 	if (!sbi->s_log_groups_per_flex)
2707 		return 0;
2708 
2709 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2710 	if (size <= sbi->s_flex_groups_allocated)
2711 		return 0;
2712 
2713 	new_groups = kvzalloc(roundup_pow_of_two(size *
2714 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2715 	if (!new_groups) {
2716 		ext4_msg(sb, KERN_ERR,
2717 			 "not enough memory for %d flex group pointers", size);
2718 		return -ENOMEM;
2719 	}
2720 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2721 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2722 					 sizeof(struct flex_groups)),
2723 					 GFP_KERNEL);
2724 		if (!new_groups[i]) {
2725 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2726 				kvfree(new_groups[j]);
2727 			kvfree(new_groups);
2728 			ext4_msg(sb, KERN_ERR,
2729 				 "not enough memory for %d flex groups", size);
2730 			return -ENOMEM;
2731 		}
2732 	}
2733 	rcu_read_lock();
2734 	old_groups = rcu_dereference(sbi->s_flex_groups);
2735 	if (old_groups)
2736 		memcpy(new_groups, old_groups,
2737 		       (sbi->s_flex_groups_allocated *
2738 			sizeof(struct flex_groups *)));
2739 	rcu_read_unlock();
2740 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2741 	sbi->s_flex_groups_allocated = size;
2742 	if (old_groups)
2743 		ext4_kvfree_array_rcu(old_groups);
2744 	return 0;
2745 }
2746 
2747 static int ext4_fill_flex_info(struct super_block *sb)
2748 {
2749 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2750 	struct ext4_group_desc *gdp = NULL;
2751 	struct flex_groups *fg;
2752 	ext4_group_t flex_group;
2753 	int i, err;
2754 
2755 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2756 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2757 		sbi->s_log_groups_per_flex = 0;
2758 		return 1;
2759 	}
2760 
2761 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2762 	if (err)
2763 		goto failed;
2764 
2765 	for (i = 0; i < sbi->s_groups_count; i++) {
2766 		gdp = ext4_get_group_desc(sb, i, NULL);
2767 
2768 		flex_group = ext4_flex_group(sbi, i);
2769 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2770 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2771 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2772 			     &fg->free_clusters);
2773 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2774 	}
2775 
2776 	return 1;
2777 failed:
2778 	return 0;
2779 }
2780 
2781 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2782 				   struct ext4_group_desc *gdp)
2783 {
2784 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2785 	__u16 crc = 0;
2786 	__le32 le_group = cpu_to_le32(block_group);
2787 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2788 
2789 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2790 		/* Use new metadata_csum algorithm */
2791 		__u32 csum32;
2792 		__u16 dummy_csum = 0;
2793 
2794 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2795 				     sizeof(le_group));
2796 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2797 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2798 				     sizeof(dummy_csum));
2799 		offset += sizeof(dummy_csum);
2800 		if (offset < sbi->s_desc_size)
2801 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2802 					     sbi->s_desc_size - offset);
2803 
2804 		crc = csum32 & 0xFFFF;
2805 		goto out;
2806 	}
2807 
2808 	/* old crc16 code */
2809 	if (!ext4_has_feature_gdt_csum(sb))
2810 		return 0;
2811 
2812 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2813 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2814 	crc = crc16(crc, (__u8 *)gdp, offset);
2815 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2816 	/* for checksum of struct ext4_group_desc do the rest...*/
2817 	if (ext4_has_feature_64bit(sb) &&
2818 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2819 		crc = crc16(crc, (__u8 *)gdp + offset,
2820 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2821 				offset);
2822 
2823 out:
2824 	return cpu_to_le16(crc);
2825 }
2826 
2827 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2828 				struct ext4_group_desc *gdp)
2829 {
2830 	if (ext4_has_group_desc_csum(sb) &&
2831 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2832 		return 0;
2833 
2834 	return 1;
2835 }
2836 
2837 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2838 			      struct ext4_group_desc *gdp)
2839 {
2840 	if (!ext4_has_group_desc_csum(sb))
2841 		return;
2842 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2843 }
2844 
2845 /* Called at mount-time, super-block is locked */
2846 static int ext4_check_descriptors(struct super_block *sb,
2847 				  ext4_fsblk_t sb_block,
2848 				  ext4_group_t *first_not_zeroed)
2849 {
2850 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2851 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2852 	ext4_fsblk_t last_block;
2853 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2854 	ext4_fsblk_t block_bitmap;
2855 	ext4_fsblk_t inode_bitmap;
2856 	ext4_fsblk_t inode_table;
2857 	int flexbg_flag = 0;
2858 	ext4_group_t i, grp = sbi->s_groups_count;
2859 
2860 	if (ext4_has_feature_flex_bg(sb))
2861 		flexbg_flag = 1;
2862 
2863 	ext4_debug("Checking group descriptors");
2864 
2865 	for (i = 0; i < sbi->s_groups_count; i++) {
2866 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2867 
2868 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2869 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2870 		else
2871 			last_block = first_block +
2872 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2873 
2874 		if ((grp == sbi->s_groups_count) &&
2875 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2876 			grp = i;
2877 
2878 		block_bitmap = ext4_block_bitmap(sb, gdp);
2879 		if (block_bitmap == sb_block) {
2880 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2881 				 "Block bitmap for group %u overlaps "
2882 				 "superblock", i);
2883 			if (!sb_rdonly(sb))
2884 				return 0;
2885 		}
2886 		if (block_bitmap >= sb_block + 1 &&
2887 		    block_bitmap <= last_bg_block) {
2888 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2889 				 "Block bitmap for group %u overlaps "
2890 				 "block group descriptors", i);
2891 			if (!sb_rdonly(sb))
2892 				return 0;
2893 		}
2894 		if (block_bitmap < first_block || block_bitmap > last_block) {
2895 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2896 			       "Block bitmap for group %u not in group "
2897 			       "(block %llu)!", i, block_bitmap);
2898 			return 0;
2899 		}
2900 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2901 		if (inode_bitmap == sb_block) {
2902 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2903 				 "Inode bitmap for group %u overlaps "
2904 				 "superblock", i);
2905 			if (!sb_rdonly(sb))
2906 				return 0;
2907 		}
2908 		if (inode_bitmap >= sb_block + 1 &&
2909 		    inode_bitmap <= last_bg_block) {
2910 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2911 				 "Inode bitmap for group %u overlaps "
2912 				 "block group descriptors", i);
2913 			if (!sb_rdonly(sb))
2914 				return 0;
2915 		}
2916 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2917 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2918 			       "Inode bitmap for group %u not in group "
2919 			       "(block %llu)!", i, inode_bitmap);
2920 			return 0;
2921 		}
2922 		inode_table = ext4_inode_table(sb, gdp);
2923 		if (inode_table == sb_block) {
2924 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2925 				 "Inode table for group %u overlaps "
2926 				 "superblock", i);
2927 			if (!sb_rdonly(sb))
2928 				return 0;
2929 		}
2930 		if (inode_table >= sb_block + 1 &&
2931 		    inode_table <= last_bg_block) {
2932 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2933 				 "Inode table for group %u overlaps "
2934 				 "block group descriptors", i);
2935 			if (!sb_rdonly(sb))
2936 				return 0;
2937 		}
2938 		if (inode_table < first_block ||
2939 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2940 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2941 			       "Inode table for group %u not in group "
2942 			       "(block %llu)!", i, inode_table);
2943 			return 0;
2944 		}
2945 		ext4_lock_group(sb, i);
2946 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2947 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2948 				 "Checksum for group %u failed (%u!=%u)",
2949 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2950 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2951 			if (!sb_rdonly(sb)) {
2952 				ext4_unlock_group(sb, i);
2953 				return 0;
2954 			}
2955 		}
2956 		ext4_unlock_group(sb, i);
2957 		if (!flexbg_flag)
2958 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2959 	}
2960 	if (NULL != first_not_zeroed)
2961 		*first_not_zeroed = grp;
2962 	return 1;
2963 }
2964 
2965 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2966  * the superblock) which were deleted from all directories, but held open by
2967  * a process at the time of a crash.  We walk the list and try to delete these
2968  * inodes at recovery time (only with a read-write filesystem).
2969  *
2970  * In order to keep the orphan inode chain consistent during traversal (in
2971  * case of crash during recovery), we link each inode into the superblock
2972  * orphan list_head and handle it the same way as an inode deletion during
2973  * normal operation (which journals the operations for us).
2974  *
2975  * We only do an iget() and an iput() on each inode, which is very safe if we
2976  * accidentally point at an in-use or already deleted inode.  The worst that
2977  * can happen in this case is that we get a "bit already cleared" message from
2978  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2979  * e2fsck was run on this filesystem, and it must have already done the orphan
2980  * inode cleanup for us, so we can safely abort without any further action.
2981  */
2982 static void ext4_orphan_cleanup(struct super_block *sb,
2983 				struct ext4_super_block *es)
2984 {
2985 	unsigned int s_flags = sb->s_flags;
2986 	int ret, nr_orphans = 0, nr_truncates = 0;
2987 #ifdef CONFIG_QUOTA
2988 	int quota_update = 0;
2989 	int i;
2990 #endif
2991 	if (!es->s_last_orphan) {
2992 		jbd_debug(4, "no orphan inodes to clean up\n");
2993 		return;
2994 	}
2995 
2996 	if (bdev_read_only(sb->s_bdev)) {
2997 		ext4_msg(sb, KERN_ERR, "write access "
2998 			"unavailable, skipping orphan cleanup");
2999 		return;
3000 	}
3001 
3002 	/* Check if feature set would not allow a r/w mount */
3003 	if (!ext4_feature_set_ok(sb, 0)) {
3004 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
3005 			 "unknown ROCOMPAT features");
3006 		return;
3007 	}
3008 
3009 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3010 		/* don't clear list on RO mount w/ errors */
3011 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
3012 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
3013 				  "clearing orphan list.\n");
3014 			es->s_last_orphan = 0;
3015 		}
3016 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3017 		return;
3018 	}
3019 
3020 	if (s_flags & SB_RDONLY) {
3021 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
3022 		sb->s_flags &= ~SB_RDONLY;
3023 	}
3024 #ifdef CONFIG_QUOTA
3025 	/* Needed for iput() to work correctly and not trash data */
3026 	sb->s_flags |= SB_ACTIVE;
3027 
3028 	/*
3029 	 * Turn on quotas which were not enabled for read-only mounts if
3030 	 * filesystem has quota feature, so that they are updated correctly.
3031 	 */
3032 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
3033 		int ret = ext4_enable_quotas(sb);
3034 
3035 		if (!ret)
3036 			quota_update = 1;
3037 		else
3038 			ext4_msg(sb, KERN_ERR,
3039 				"Cannot turn on quotas: error %d", ret);
3040 	}
3041 
3042 	/* Turn on journaled quotas used for old sytle */
3043 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3044 		if (EXT4_SB(sb)->s_qf_names[i]) {
3045 			int ret = ext4_quota_on_mount(sb, i);
3046 
3047 			if (!ret)
3048 				quota_update = 1;
3049 			else
3050 				ext4_msg(sb, KERN_ERR,
3051 					"Cannot turn on journaled "
3052 					"quota: type %d: error %d", i, ret);
3053 		}
3054 	}
3055 #endif
3056 
3057 	while (es->s_last_orphan) {
3058 		struct inode *inode;
3059 
3060 		/*
3061 		 * We may have encountered an error during cleanup; if
3062 		 * so, skip the rest.
3063 		 */
3064 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3065 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3066 			es->s_last_orphan = 0;
3067 			break;
3068 		}
3069 
3070 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
3071 		if (IS_ERR(inode)) {
3072 			es->s_last_orphan = 0;
3073 			break;
3074 		}
3075 
3076 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
3077 		dquot_initialize(inode);
3078 		if (inode->i_nlink) {
3079 			if (test_opt(sb, DEBUG))
3080 				ext4_msg(sb, KERN_DEBUG,
3081 					"%s: truncating inode %lu to %lld bytes",
3082 					__func__, inode->i_ino, inode->i_size);
3083 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
3084 				  inode->i_ino, inode->i_size);
3085 			inode_lock(inode);
3086 			truncate_inode_pages(inode->i_mapping, inode->i_size);
3087 			ret = ext4_truncate(inode);
3088 			if (ret)
3089 				ext4_std_error(inode->i_sb, ret);
3090 			inode_unlock(inode);
3091 			nr_truncates++;
3092 		} else {
3093 			if (test_opt(sb, DEBUG))
3094 				ext4_msg(sb, KERN_DEBUG,
3095 					"%s: deleting unreferenced inode %lu",
3096 					__func__, inode->i_ino);
3097 			jbd_debug(2, "deleting unreferenced inode %lu\n",
3098 				  inode->i_ino);
3099 			nr_orphans++;
3100 		}
3101 		iput(inode);  /* The delete magic happens here! */
3102 	}
3103 
3104 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
3105 
3106 	if (nr_orphans)
3107 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
3108 		       PLURAL(nr_orphans));
3109 	if (nr_truncates)
3110 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
3111 		       PLURAL(nr_truncates));
3112 #ifdef CONFIG_QUOTA
3113 	/* Turn off quotas if they were enabled for orphan cleanup */
3114 	if (quota_update) {
3115 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3116 			if (sb_dqopt(sb)->files[i])
3117 				dquot_quota_off(sb, i);
3118 		}
3119 	}
3120 #endif
3121 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
3122 }
3123 
3124 /*
3125  * Maximal extent format file size.
3126  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3127  * extent format containers, within a sector_t, and within i_blocks
3128  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3129  * so that won't be a limiting factor.
3130  *
3131  * However there is other limiting factor. We do store extents in the form
3132  * of starting block and length, hence the resulting length of the extent
3133  * covering maximum file size must fit into on-disk format containers as
3134  * well. Given that length is always by 1 unit bigger than max unit (because
3135  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3136  *
3137  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3138  */
3139 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3140 {
3141 	loff_t res;
3142 	loff_t upper_limit = MAX_LFS_FILESIZE;
3143 
3144 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3145 
3146 	if (!has_huge_files) {
3147 		upper_limit = (1LL << 32) - 1;
3148 
3149 		/* total blocks in file system block size */
3150 		upper_limit >>= (blkbits - 9);
3151 		upper_limit <<= blkbits;
3152 	}
3153 
3154 	/*
3155 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3156 	 * by one fs block, so ee_len can cover the extent of maximum file
3157 	 * size
3158 	 */
3159 	res = (1LL << 32) - 1;
3160 	res <<= blkbits;
3161 
3162 	/* Sanity check against vm- & vfs- imposed limits */
3163 	if (res > upper_limit)
3164 		res = upper_limit;
3165 
3166 	return res;
3167 }
3168 
3169 /*
3170  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3171  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3172  * We need to be 1 filesystem block less than the 2^48 sector limit.
3173  */
3174 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3175 {
3176 	loff_t res = EXT4_NDIR_BLOCKS;
3177 	int meta_blocks;
3178 	loff_t upper_limit;
3179 	/* This is calculated to be the largest file size for a dense, block
3180 	 * mapped file such that the file's total number of 512-byte sectors,
3181 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3182 	 *
3183 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3184 	 * number of 512-byte sectors of the file.
3185 	 */
3186 
3187 	if (!has_huge_files) {
3188 		/*
3189 		 * !has_huge_files or implies that the inode i_block field
3190 		 * represents total file blocks in 2^32 512-byte sectors ==
3191 		 * size of vfs inode i_blocks * 8
3192 		 */
3193 		upper_limit = (1LL << 32) - 1;
3194 
3195 		/* total blocks in file system block size */
3196 		upper_limit >>= (bits - 9);
3197 
3198 	} else {
3199 		/*
3200 		 * We use 48 bit ext4_inode i_blocks
3201 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3202 		 * represent total number of blocks in
3203 		 * file system block size
3204 		 */
3205 		upper_limit = (1LL << 48) - 1;
3206 
3207 	}
3208 
3209 	/* indirect blocks */
3210 	meta_blocks = 1;
3211 	/* double indirect blocks */
3212 	meta_blocks += 1 + (1LL << (bits-2));
3213 	/* tripple indirect blocks */
3214 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3215 
3216 	upper_limit -= meta_blocks;
3217 	upper_limit <<= bits;
3218 
3219 	res += 1LL << (bits-2);
3220 	res += 1LL << (2*(bits-2));
3221 	res += 1LL << (3*(bits-2));
3222 	res <<= bits;
3223 	if (res > upper_limit)
3224 		res = upper_limit;
3225 
3226 	if (res > MAX_LFS_FILESIZE)
3227 		res = MAX_LFS_FILESIZE;
3228 
3229 	return res;
3230 }
3231 
3232 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3233 				   ext4_fsblk_t logical_sb_block, int nr)
3234 {
3235 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3236 	ext4_group_t bg, first_meta_bg;
3237 	int has_super = 0;
3238 
3239 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3240 
3241 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3242 		return logical_sb_block + nr + 1;
3243 	bg = sbi->s_desc_per_block * nr;
3244 	if (ext4_bg_has_super(sb, bg))
3245 		has_super = 1;
3246 
3247 	/*
3248 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3249 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3250 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3251 	 * compensate.
3252 	 */
3253 	if (sb->s_blocksize == 1024 && nr == 0 &&
3254 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3255 		has_super++;
3256 
3257 	return (has_super + ext4_group_first_block_no(sb, bg));
3258 }
3259 
3260 /**
3261  * ext4_get_stripe_size: Get the stripe size.
3262  * @sbi: In memory super block info
3263  *
3264  * If we have specified it via mount option, then
3265  * use the mount option value. If the value specified at mount time is
3266  * greater than the blocks per group use the super block value.
3267  * If the super block value is greater than blocks per group return 0.
3268  * Allocator needs it be less than blocks per group.
3269  *
3270  */
3271 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3272 {
3273 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3274 	unsigned long stripe_width =
3275 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3276 	int ret;
3277 
3278 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3279 		ret = sbi->s_stripe;
3280 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3281 		ret = stripe_width;
3282 	else if (stride && stride <= sbi->s_blocks_per_group)
3283 		ret = stride;
3284 	else
3285 		ret = 0;
3286 
3287 	/*
3288 	 * If the stripe width is 1, this makes no sense and
3289 	 * we set it to 0 to turn off stripe handling code.
3290 	 */
3291 	if (ret <= 1)
3292 		ret = 0;
3293 
3294 	return ret;
3295 }
3296 
3297 /*
3298  * Check whether this filesystem can be mounted based on
3299  * the features present and the RDONLY/RDWR mount requested.
3300  * Returns 1 if this filesystem can be mounted as requested,
3301  * 0 if it cannot be.
3302  */
3303 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3304 {
3305 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3306 		ext4_msg(sb, KERN_ERR,
3307 			"Couldn't mount because of "
3308 			"unsupported optional features (%x)",
3309 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3310 			~EXT4_FEATURE_INCOMPAT_SUPP));
3311 		return 0;
3312 	}
3313 
3314 #ifndef CONFIG_UNICODE
3315 	if (ext4_has_feature_casefold(sb)) {
3316 		ext4_msg(sb, KERN_ERR,
3317 			 "Filesystem with casefold feature cannot be "
3318 			 "mounted without CONFIG_UNICODE");
3319 		return 0;
3320 	}
3321 #endif
3322 
3323 	if (readonly)
3324 		return 1;
3325 
3326 	if (ext4_has_feature_readonly(sb)) {
3327 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3328 		sb->s_flags |= SB_RDONLY;
3329 		return 1;
3330 	}
3331 
3332 	/* Check that feature set is OK for a read-write mount */
3333 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3334 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3335 			 "unsupported optional features (%x)",
3336 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3337 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3338 		return 0;
3339 	}
3340 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3341 		ext4_msg(sb, KERN_ERR,
3342 			 "Can't support bigalloc feature without "
3343 			 "extents feature\n");
3344 		return 0;
3345 	}
3346 
3347 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3348 	if (!readonly && (ext4_has_feature_quota(sb) ||
3349 			  ext4_has_feature_project(sb))) {
3350 		ext4_msg(sb, KERN_ERR,
3351 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3352 		return 0;
3353 	}
3354 #endif  /* CONFIG_QUOTA */
3355 	return 1;
3356 }
3357 
3358 /*
3359  * This function is called once a day if we have errors logged
3360  * on the file system
3361  */
3362 static void print_daily_error_info(struct timer_list *t)
3363 {
3364 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3365 	struct super_block *sb = sbi->s_sb;
3366 	struct ext4_super_block *es = sbi->s_es;
3367 
3368 	if (es->s_error_count)
3369 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3370 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3371 			 le32_to_cpu(es->s_error_count));
3372 	if (es->s_first_error_time) {
3373 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3374 		       sb->s_id,
3375 		       ext4_get_tstamp(es, s_first_error_time),
3376 		       (int) sizeof(es->s_first_error_func),
3377 		       es->s_first_error_func,
3378 		       le32_to_cpu(es->s_first_error_line));
3379 		if (es->s_first_error_ino)
3380 			printk(KERN_CONT ": inode %u",
3381 			       le32_to_cpu(es->s_first_error_ino));
3382 		if (es->s_first_error_block)
3383 			printk(KERN_CONT ": block %llu", (unsigned long long)
3384 			       le64_to_cpu(es->s_first_error_block));
3385 		printk(KERN_CONT "\n");
3386 	}
3387 	if (es->s_last_error_time) {
3388 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3389 		       sb->s_id,
3390 		       ext4_get_tstamp(es, s_last_error_time),
3391 		       (int) sizeof(es->s_last_error_func),
3392 		       es->s_last_error_func,
3393 		       le32_to_cpu(es->s_last_error_line));
3394 		if (es->s_last_error_ino)
3395 			printk(KERN_CONT ": inode %u",
3396 			       le32_to_cpu(es->s_last_error_ino));
3397 		if (es->s_last_error_block)
3398 			printk(KERN_CONT ": block %llu", (unsigned long long)
3399 			       le64_to_cpu(es->s_last_error_block));
3400 		printk(KERN_CONT "\n");
3401 	}
3402 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3403 }
3404 
3405 /* Find next suitable group and run ext4_init_inode_table */
3406 static int ext4_run_li_request(struct ext4_li_request *elr)
3407 {
3408 	struct ext4_group_desc *gdp = NULL;
3409 	struct super_block *sb = elr->lr_super;
3410 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3411 	ext4_group_t group = elr->lr_next_group;
3412 	unsigned long timeout = 0;
3413 	unsigned int prefetch_ios = 0;
3414 	int ret = 0;
3415 
3416 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3417 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3418 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3419 		if (prefetch_ios)
3420 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3421 					      prefetch_ios);
3422 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3423 					    prefetch_ios);
3424 		if (group >= elr->lr_next_group) {
3425 			ret = 1;
3426 			if (elr->lr_first_not_zeroed != ngroups &&
3427 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3428 				elr->lr_next_group = elr->lr_first_not_zeroed;
3429 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3430 				ret = 0;
3431 			}
3432 		}
3433 		return ret;
3434 	}
3435 
3436 	for (; group < ngroups; group++) {
3437 		gdp = ext4_get_group_desc(sb, group, NULL);
3438 		if (!gdp) {
3439 			ret = 1;
3440 			break;
3441 		}
3442 
3443 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3444 			break;
3445 	}
3446 
3447 	if (group >= ngroups)
3448 		ret = 1;
3449 
3450 	if (!ret) {
3451 		timeout = jiffies;
3452 		ret = ext4_init_inode_table(sb, group,
3453 					    elr->lr_timeout ? 0 : 1);
3454 		trace_ext4_lazy_itable_init(sb, group);
3455 		if (elr->lr_timeout == 0) {
3456 			timeout = (jiffies - timeout) *
3457 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3458 			elr->lr_timeout = timeout;
3459 		}
3460 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3461 		elr->lr_next_group = group + 1;
3462 	}
3463 	return ret;
3464 }
3465 
3466 /*
3467  * Remove lr_request from the list_request and free the
3468  * request structure. Should be called with li_list_mtx held
3469  */
3470 static void ext4_remove_li_request(struct ext4_li_request *elr)
3471 {
3472 	if (!elr)
3473 		return;
3474 
3475 	list_del(&elr->lr_request);
3476 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3477 	kfree(elr);
3478 }
3479 
3480 static void ext4_unregister_li_request(struct super_block *sb)
3481 {
3482 	mutex_lock(&ext4_li_mtx);
3483 	if (!ext4_li_info) {
3484 		mutex_unlock(&ext4_li_mtx);
3485 		return;
3486 	}
3487 
3488 	mutex_lock(&ext4_li_info->li_list_mtx);
3489 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3490 	mutex_unlock(&ext4_li_info->li_list_mtx);
3491 	mutex_unlock(&ext4_li_mtx);
3492 }
3493 
3494 static struct task_struct *ext4_lazyinit_task;
3495 
3496 /*
3497  * This is the function where ext4lazyinit thread lives. It walks
3498  * through the request list searching for next scheduled filesystem.
3499  * When such a fs is found, run the lazy initialization request
3500  * (ext4_rn_li_request) and keep track of the time spend in this
3501  * function. Based on that time we compute next schedule time of
3502  * the request. When walking through the list is complete, compute
3503  * next waking time and put itself into sleep.
3504  */
3505 static int ext4_lazyinit_thread(void *arg)
3506 {
3507 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3508 	struct list_head *pos, *n;
3509 	struct ext4_li_request *elr;
3510 	unsigned long next_wakeup, cur;
3511 
3512 	BUG_ON(NULL == eli);
3513 
3514 cont_thread:
3515 	while (true) {
3516 		next_wakeup = MAX_JIFFY_OFFSET;
3517 
3518 		mutex_lock(&eli->li_list_mtx);
3519 		if (list_empty(&eli->li_request_list)) {
3520 			mutex_unlock(&eli->li_list_mtx);
3521 			goto exit_thread;
3522 		}
3523 		list_for_each_safe(pos, n, &eli->li_request_list) {
3524 			int err = 0;
3525 			int progress = 0;
3526 			elr = list_entry(pos, struct ext4_li_request,
3527 					 lr_request);
3528 
3529 			if (time_before(jiffies, elr->lr_next_sched)) {
3530 				if (time_before(elr->lr_next_sched, next_wakeup))
3531 					next_wakeup = elr->lr_next_sched;
3532 				continue;
3533 			}
3534 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3535 				if (sb_start_write_trylock(elr->lr_super)) {
3536 					progress = 1;
3537 					/*
3538 					 * We hold sb->s_umount, sb can not
3539 					 * be removed from the list, it is
3540 					 * now safe to drop li_list_mtx
3541 					 */
3542 					mutex_unlock(&eli->li_list_mtx);
3543 					err = ext4_run_li_request(elr);
3544 					sb_end_write(elr->lr_super);
3545 					mutex_lock(&eli->li_list_mtx);
3546 					n = pos->next;
3547 				}
3548 				up_read((&elr->lr_super->s_umount));
3549 			}
3550 			/* error, remove the lazy_init job */
3551 			if (err) {
3552 				ext4_remove_li_request(elr);
3553 				continue;
3554 			}
3555 			if (!progress) {
3556 				elr->lr_next_sched = jiffies +
3557 					(prandom_u32()
3558 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3559 			}
3560 			if (time_before(elr->lr_next_sched, next_wakeup))
3561 				next_wakeup = elr->lr_next_sched;
3562 		}
3563 		mutex_unlock(&eli->li_list_mtx);
3564 
3565 		try_to_freeze();
3566 
3567 		cur = jiffies;
3568 		if ((time_after_eq(cur, next_wakeup)) ||
3569 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3570 			cond_resched();
3571 			continue;
3572 		}
3573 
3574 		schedule_timeout_interruptible(next_wakeup - cur);
3575 
3576 		if (kthread_should_stop()) {
3577 			ext4_clear_request_list();
3578 			goto exit_thread;
3579 		}
3580 	}
3581 
3582 exit_thread:
3583 	/*
3584 	 * It looks like the request list is empty, but we need
3585 	 * to check it under the li_list_mtx lock, to prevent any
3586 	 * additions into it, and of course we should lock ext4_li_mtx
3587 	 * to atomically free the list and ext4_li_info, because at
3588 	 * this point another ext4 filesystem could be registering
3589 	 * new one.
3590 	 */
3591 	mutex_lock(&ext4_li_mtx);
3592 	mutex_lock(&eli->li_list_mtx);
3593 	if (!list_empty(&eli->li_request_list)) {
3594 		mutex_unlock(&eli->li_list_mtx);
3595 		mutex_unlock(&ext4_li_mtx);
3596 		goto cont_thread;
3597 	}
3598 	mutex_unlock(&eli->li_list_mtx);
3599 	kfree(ext4_li_info);
3600 	ext4_li_info = NULL;
3601 	mutex_unlock(&ext4_li_mtx);
3602 
3603 	return 0;
3604 }
3605 
3606 static void ext4_clear_request_list(void)
3607 {
3608 	struct list_head *pos, *n;
3609 	struct ext4_li_request *elr;
3610 
3611 	mutex_lock(&ext4_li_info->li_list_mtx);
3612 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3613 		elr = list_entry(pos, struct ext4_li_request,
3614 				 lr_request);
3615 		ext4_remove_li_request(elr);
3616 	}
3617 	mutex_unlock(&ext4_li_info->li_list_mtx);
3618 }
3619 
3620 static int ext4_run_lazyinit_thread(void)
3621 {
3622 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3623 					 ext4_li_info, "ext4lazyinit");
3624 	if (IS_ERR(ext4_lazyinit_task)) {
3625 		int err = PTR_ERR(ext4_lazyinit_task);
3626 		ext4_clear_request_list();
3627 		kfree(ext4_li_info);
3628 		ext4_li_info = NULL;
3629 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3630 				 "initialization thread\n",
3631 				 err);
3632 		return err;
3633 	}
3634 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3635 	return 0;
3636 }
3637 
3638 /*
3639  * Check whether it make sense to run itable init. thread or not.
3640  * If there is at least one uninitialized inode table, return
3641  * corresponding group number, else the loop goes through all
3642  * groups and return total number of groups.
3643  */
3644 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3645 {
3646 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3647 	struct ext4_group_desc *gdp = NULL;
3648 
3649 	if (!ext4_has_group_desc_csum(sb))
3650 		return ngroups;
3651 
3652 	for (group = 0; group < ngroups; group++) {
3653 		gdp = ext4_get_group_desc(sb, group, NULL);
3654 		if (!gdp)
3655 			continue;
3656 
3657 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3658 			break;
3659 	}
3660 
3661 	return group;
3662 }
3663 
3664 static int ext4_li_info_new(void)
3665 {
3666 	struct ext4_lazy_init *eli = NULL;
3667 
3668 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3669 	if (!eli)
3670 		return -ENOMEM;
3671 
3672 	INIT_LIST_HEAD(&eli->li_request_list);
3673 	mutex_init(&eli->li_list_mtx);
3674 
3675 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3676 
3677 	ext4_li_info = eli;
3678 
3679 	return 0;
3680 }
3681 
3682 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3683 					    ext4_group_t start)
3684 {
3685 	struct ext4_li_request *elr;
3686 
3687 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3688 	if (!elr)
3689 		return NULL;
3690 
3691 	elr->lr_super = sb;
3692 	elr->lr_first_not_zeroed = start;
3693 	if (test_opt(sb, PREFETCH_BLOCK_BITMAPS))
3694 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3695 	else {
3696 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3697 		elr->lr_next_group = start;
3698 	}
3699 
3700 	/*
3701 	 * Randomize first schedule time of the request to
3702 	 * spread the inode table initialization requests
3703 	 * better.
3704 	 */
3705 	elr->lr_next_sched = jiffies + (prandom_u32() %
3706 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3707 	return elr;
3708 }
3709 
3710 int ext4_register_li_request(struct super_block *sb,
3711 			     ext4_group_t first_not_zeroed)
3712 {
3713 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3714 	struct ext4_li_request *elr = NULL;
3715 	ext4_group_t ngroups = sbi->s_groups_count;
3716 	int ret = 0;
3717 
3718 	mutex_lock(&ext4_li_mtx);
3719 	if (sbi->s_li_request != NULL) {
3720 		/*
3721 		 * Reset timeout so it can be computed again, because
3722 		 * s_li_wait_mult might have changed.
3723 		 */
3724 		sbi->s_li_request->lr_timeout = 0;
3725 		goto out;
3726 	}
3727 
3728 	if (!test_opt(sb, PREFETCH_BLOCK_BITMAPS) &&
3729 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3730 	     !test_opt(sb, INIT_INODE_TABLE)))
3731 		goto out;
3732 
3733 	elr = ext4_li_request_new(sb, first_not_zeroed);
3734 	if (!elr) {
3735 		ret = -ENOMEM;
3736 		goto out;
3737 	}
3738 
3739 	if (NULL == ext4_li_info) {
3740 		ret = ext4_li_info_new();
3741 		if (ret)
3742 			goto out;
3743 	}
3744 
3745 	mutex_lock(&ext4_li_info->li_list_mtx);
3746 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3747 	mutex_unlock(&ext4_li_info->li_list_mtx);
3748 
3749 	sbi->s_li_request = elr;
3750 	/*
3751 	 * set elr to NULL here since it has been inserted to
3752 	 * the request_list and the removal and free of it is
3753 	 * handled by ext4_clear_request_list from now on.
3754 	 */
3755 	elr = NULL;
3756 
3757 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3758 		ret = ext4_run_lazyinit_thread();
3759 		if (ret)
3760 			goto out;
3761 	}
3762 out:
3763 	mutex_unlock(&ext4_li_mtx);
3764 	if (ret)
3765 		kfree(elr);
3766 	return ret;
3767 }
3768 
3769 /*
3770  * We do not need to lock anything since this is called on
3771  * module unload.
3772  */
3773 static void ext4_destroy_lazyinit_thread(void)
3774 {
3775 	/*
3776 	 * If thread exited earlier
3777 	 * there's nothing to be done.
3778 	 */
3779 	if (!ext4_li_info || !ext4_lazyinit_task)
3780 		return;
3781 
3782 	kthread_stop(ext4_lazyinit_task);
3783 }
3784 
3785 static int set_journal_csum_feature_set(struct super_block *sb)
3786 {
3787 	int ret = 1;
3788 	int compat, incompat;
3789 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3790 
3791 	if (ext4_has_metadata_csum(sb)) {
3792 		/* journal checksum v3 */
3793 		compat = 0;
3794 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3795 	} else {
3796 		/* journal checksum v1 */
3797 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3798 		incompat = 0;
3799 	}
3800 
3801 	jbd2_journal_clear_features(sbi->s_journal,
3802 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3803 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3804 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3805 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3806 		ret = jbd2_journal_set_features(sbi->s_journal,
3807 				compat, 0,
3808 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3809 				incompat);
3810 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3811 		ret = jbd2_journal_set_features(sbi->s_journal,
3812 				compat, 0,
3813 				incompat);
3814 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3815 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3816 	} else {
3817 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3818 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3819 	}
3820 
3821 	return ret;
3822 }
3823 
3824 /*
3825  * Note: calculating the overhead so we can be compatible with
3826  * historical BSD practice is quite difficult in the face of
3827  * clusters/bigalloc.  This is because multiple metadata blocks from
3828  * different block group can end up in the same allocation cluster.
3829  * Calculating the exact overhead in the face of clustered allocation
3830  * requires either O(all block bitmaps) in memory or O(number of block
3831  * groups**2) in time.  We will still calculate the superblock for
3832  * older file systems --- and if we come across with a bigalloc file
3833  * system with zero in s_overhead_clusters the estimate will be close to
3834  * correct especially for very large cluster sizes --- but for newer
3835  * file systems, it's better to calculate this figure once at mkfs
3836  * time, and store it in the superblock.  If the superblock value is
3837  * present (even for non-bigalloc file systems), we will use it.
3838  */
3839 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3840 			  char *buf)
3841 {
3842 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3843 	struct ext4_group_desc	*gdp;
3844 	ext4_fsblk_t		first_block, last_block, b;
3845 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3846 	int			s, j, count = 0;
3847 
3848 	if (!ext4_has_feature_bigalloc(sb))
3849 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3850 			sbi->s_itb_per_group + 2);
3851 
3852 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3853 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3854 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3855 	for (i = 0; i < ngroups; i++) {
3856 		gdp = ext4_get_group_desc(sb, i, NULL);
3857 		b = ext4_block_bitmap(sb, gdp);
3858 		if (b >= first_block && b <= last_block) {
3859 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3860 			count++;
3861 		}
3862 		b = ext4_inode_bitmap(sb, gdp);
3863 		if (b >= first_block && b <= last_block) {
3864 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3865 			count++;
3866 		}
3867 		b = ext4_inode_table(sb, gdp);
3868 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3869 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3870 				int c = EXT4_B2C(sbi, b - first_block);
3871 				ext4_set_bit(c, buf);
3872 				count++;
3873 			}
3874 		if (i != grp)
3875 			continue;
3876 		s = 0;
3877 		if (ext4_bg_has_super(sb, grp)) {
3878 			ext4_set_bit(s++, buf);
3879 			count++;
3880 		}
3881 		j = ext4_bg_num_gdb(sb, grp);
3882 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3883 			ext4_error(sb, "Invalid number of block group "
3884 				   "descriptor blocks: %d", j);
3885 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3886 		}
3887 		count += j;
3888 		for (; j > 0; j--)
3889 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3890 	}
3891 	if (!count)
3892 		return 0;
3893 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3894 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3895 }
3896 
3897 /*
3898  * Compute the overhead and stash it in sbi->s_overhead
3899  */
3900 int ext4_calculate_overhead(struct super_block *sb)
3901 {
3902 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3903 	struct ext4_super_block *es = sbi->s_es;
3904 	struct inode *j_inode;
3905 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3906 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3907 	ext4_fsblk_t overhead = 0;
3908 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3909 
3910 	if (!buf)
3911 		return -ENOMEM;
3912 
3913 	/*
3914 	 * Compute the overhead (FS structures).  This is constant
3915 	 * for a given filesystem unless the number of block groups
3916 	 * changes so we cache the previous value until it does.
3917 	 */
3918 
3919 	/*
3920 	 * All of the blocks before first_data_block are overhead
3921 	 */
3922 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3923 
3924 	/*
3925 	 * Add the overhead found in each block group
3926 	 */
3927 	for (i = 0; i < ngroups; i++) {
3928 		int blks;
3929 
3930 		blks = count_overhead(sb, i, buf);
3931 		overhead += blks;
3932 		if (blks)
3933 			memset(buf, 0, PAGE_SIZE);
3934 		cond_resched();
3935 	}
3936 
3937 	/*
3938 	 * Add the internal journal blocks whether the journal has been
3939 	 * loaded or not
3940 	 */
3941 	if (sbi->s_journal && !sbi->s_journal_bdev)
3942 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
3943 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3944 		/* j_inum for internal journal is non-zero */
3945 		j_inode = ext4_get_journal_inode(sb, j_inum);
3946 		if (j_inode) {
3947 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3948 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3949 			iput(j_inode);
3950 		} else {
3951 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3952 		}
3953 	}
3954 	sbi->s_overhead = overhead;
3955 	smp_wmb();
3956 	free_page((unsigned long) buf);
3957 	return 0;
3958 }
3959 
3960 static void ext4_set_resv_clusters(struct super_block *sb)
3961 {
3962 	ext4_fsblk_t resv_clusters;
3963 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3964 
3965 	/*
3966 	 * There's no need to reserve anything when we aren't using extents.
3967 	 * The space estimates are exact, there are no unwritten extents,
3968 	 * hole punching doesn't need new metadata... This is needed especially
3969 	 * to keep ext2/3 backward compatibility.
3970 	 */
3971 	if (!ext4_has_feature_extents(sb))
3972 		return;
3973 	/*
3974 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3975 	 * This should cover the situations where we can not afford to run
3976 	 * out of space like for example punch hole, or converting
3977 	 * unwritten extents in delalloc path. In most cases such
3978 	 * allocation would require 1, or 2 blocks, higher numbers are
3979 	 * very rare.
3980 	 */
3981 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3982 			 sbi->s_cluster_bits);
3983 
3984 	do_div(resv_clusters, 50);
3985 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3986 
3987 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3988 }
3989 
3990 static const char *ext4_quota_mode(struct super_block *sb)
3991 {
3992 #ifdef CONFIG_QUOTA
3993 	if (!ext4_quota_capable(sb))
3994 		return "none";
3995 
3996 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
3997 		return "journalled";
3998 	else
3999 		return "writeback";
4000 #else
4001 	return "disabled";
4002 #endif
4003 }
4004 
4005 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
4006 {
4007 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
4008 	char *orig_data = kstrdup(data, GFP_KERNEL);
4009 	struct buffer_head *bh, **group_desc;
4010 	struct ext4_super_block *es = NULL;
4011 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4012 	struct flex_groups **flex_groups;
4013 	ext4_fsblk_t block;
4014 	ext4_fsblk_t sb_block = get_sb_block(&data);
4015 	ext4_fsblk_t logical_sb_block;
4016 	unsigned long offset = 0;
4017 	unsigned long journal_devnum = 0;
4018 	unsigned long def_mount_opts;
4019 	struct inode *root;
4020 	const char *descr;
4021 	int ret = -ENOMEM;
4022 	int blocksize, clustersize;
4023 	unsigned int db_count;
4024 	unsigned int i;
4025 	int needs_recovery, has_huge_files;
4026 	__u64 blocks_count;
4027 	int err = 0;
4028 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4029 	ext4_group_t first_not_zeroed;
4030 
4031 	if ((data && !orig_data) || !sbi)
4032 		goto out_free_base;
4033 
4034 	sbi->s_daxdev = dax_dev;
4035 	sbi->s_blockgroup_lock =
4036 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4037 	if (!sbi->s_blockgroup_lock)
4038 		goto out_free_base;
4039 
4040 	sb->s_fs_info = sbi;
4041 	sbi->s_sb = sb;
4042 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4043 	sbi->s_sb_block = sb_block;
4044 	sbi->s_sectors_written_start =
4045 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4046 
4047 	/* Cleanup superblock name */
4048 	strreplace(sb->s_id, '/', '!');
4049 
4050 	/* -EINVAL is default */
4051 	ret = -EINVAL;
4052 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4053 	if (!blocksize) {
4054 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4055 		goto out_fail;
4056 	}
4057 
4058 	/*
4059 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4060 	 * block sizes.  We need to calculate the offset from buffer start.
4061 	 */
4062 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4063 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4064 		offset = do_div(logical_sb_block, blocksize);
4065 	} else {
4066 		logical_sb_block = sb_block;
4067 	}
4068 
4069 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4070 	if (IS_ERR(bh)) {
4071 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4072 		ret = PTR_ERR(bh);
4073 		goto out_fail;
4074 	}
4075 	/*
4076 	 * Note: s_es must be initialized as soon as possible because
4077 	 *       some ext4 macro-instructions depend on its value
4078 	 */
4079 	es = (struct ext4_super_block *) (bh->b_data + offset);
4080 	sbi->s_es = es;
4081 	sb->s_magic = le16_to_cpu(es->s_magic);
4082 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4083 		goto cantfind_ext4;
4084 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4085 
4086 	/* Warn if metadata_csum and gdt_csum are both set. */
4087 	if (ext4_has_feature_metadata_csum(sb) &&
4088 	    ext4_has_feature_gdt_csum(sb))
4089 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4090 			     "redundant flags; please run fsck.");
4091 
4092 	/* Check for a known checksum algorithm */
4093 	if (!ext4_verify_csum_type(sb, es)) {
4094 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4095 			 "unknown checksum algorithm.");
4096 		silent = 1;
4097 		goto cantfind_ext4;
4098 	}
4099 
4100 	/* Load the checksum driver */
4101 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4102 	if (IS_ERR(sbi->s_chksum_driver)) {
4103 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4104 		ret = PTR_ERR(sbi->s_chksum_driver);
4105 		sbi->s_chksum_driver = NULL;
4106 		goto failed_mount;
4107 	}
4108 
4109 	/* Check superblock checksum */
4110 	if (!ext4_superblock_csum_verify(sb, es)) {
4111 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4112 			 "invalid superblock checksum.  Run e2fsck?");
4113 		silent = 1;
4114 		ret = -EFSBADCRC;
4115 		goto cantfind_ext4;
4116 	}
4117 
4118 	/* Precompute checksum seed for all metadata */
4119 	if (ext4_has_feature_csum_seed(sb))
4120 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4121 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4122 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4123 					       sizeof(es->s_uuid));
4124 
4125 	/* Set defaults before we parse the mount options */
4126 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4127 	set_opt(sb, INIT_INODE_TABLE);
4128 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4129 		set_opt(sb, DEBUG);
4130 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4131 		set_opt(sb, GRPID);
4132 	if (def_mount_opts & EXT4_DEFM_UID16)
4133 		set_opt(sb, NO_UID32);
4134 	/* xattr user namespace & acls are now defaulted on */
4135 	set_opt(sb, XATTR_USER);
4136 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4137 	set_opt(sb, POSIX_ACL);
4138 #endif
4139 	if (ext4_has_feature_fast_commit(sb))
4140 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4141 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4142 	if (ext4_has_metadata_csum(sb))
4143 		set_opt(sb, JOURNAL_CHECKSUM);
4144 
4145 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4146 		set_opt(sb, JOURNAL_DATA);
4147 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4148 		set_opt(sb, ORDERED_DATA);
4149 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4150 		set_opt(sb, WRITEBACK_DATA);
4151 
4152 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4153 		set_opt(sb, ERRORS_PANIC);
4154 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4155 		set_opt(sb, ERRORS_CONT);
4156 	else
4157 		set_opt(sb, ERRORS_RO);
4158 	/* block_validity enabled by default; disable with noblock_validity */
4159 	set_opt(sb, BLOCK_VALIDITY);
4160 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4161 		set_opt(sb, DISCARD);
4162 
4163 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4164 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4165 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4166 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4167 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4168 
4169 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4170 		set_opt(sb, BARRIER);
4171 
4172 	/*
4173 	 * enable delayed allocation by default
4174 	 * Use -o nodelalloc to turn it off
4175 	 */
4176 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4177 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4178 		set_opt(sb, DELALLOC);
4179 
4180 	/*
4181 	 * set default s_li_wait_mult for lazyinit, for the case there is
4182 	 * no mount option specified.
4183 	 */
4184 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4185 
4186 	if (le32_to_cpu(es->s_log_block_size) >
4187 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4188 		ext4_msg(sb, KERN_ERR,
4189 			 "Invalid log block size: %u",
4190 			 le32_to_cpu(es->s_log_block_size));
4191 		goto failed_mount;
4192 	}
4193 	if (le32_to_cpu(es->s_log_cluster_size) >
4194 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4195 		ext4_msg(sb, KERN_ERR,
4196 			 "Invalid log cluster size: %u",
4197 			 le32_to_cpu(es->s_log_cluster_size));
4198 		goto failed_mount;
4199 	}
4200 
4201 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4202 
4203 	if (blocksize == PAGE_SIZE)
4204 		set_opt(sb, DIOREAD_NOLOCK);
4205 
4206 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4207 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4208 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4209 	} else {
4210 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4211 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4212 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4213 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4214 				 sbi->s_first_ino);
4215 			goto failed_mount;
4216 		}
4217 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4218 		    (!is_power_of_2(sbi->s_inode_size)) ||
4219 		    (sbi->s_inode_size > blocksize)) {
4220 			ext4_msg(sb, KERN_ERR,
4221 			       "unsupported inode size: %d",
4222 			       sbi->s_inode_size);
4223 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4224 			goto failed_mount;
4225 		}
4226 		/*
4227 		 * i_atime_extra is the last extra field available for
4228 		 * [acm]times in struct ext4_inode. Checking for that
4229 		 * field should suffice to ensure we have extra space
4230 		 * for all three.
4231 		 */
4232 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4233 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4234 			sb->s_time_gran = 1;
4235 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4236 		} else {
4237 			sb->s_time_gran = NSEC_PER_SEC;
4238 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4239 		}
4240 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4241 	}
4242 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4243 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4244 			EXT4_GOOD_OLD_INODE_SIZE;
4245 		if (ext4_has_feature_extra_isize(sb)) {
4246 			unsigned v, max = (sbi->s_inode_size -
4247 					   EXT4_GOOD_OLD_INODE_SIZE);
4248 
4249 			v = le16_to_cpu(es->s_want_extra_isize);
4250 			if (v > max) {
4251 				ext4_msg(sb, KERN_ERR,
4252 					 "bad s_want_extra_isize: %d", v);
4253 				goto failed_mount;
4254 			}
4255 			if (sbi->s_want_extra_isize < v)
4256 				sbi->s_want_extra_isize = v;
4257 
4258 			v = le16_to_cpu(es->s_min_extra_isize);
4259 			if (v > max) {
4260 				ext4_msg(sb, KERN_ERR,
4261 					 "bad s_min_extra_isize: %d", v);
4262 				goto failed_mount;
4263 			}
4264 			if (sbi->s_want_extra_isize < v)
4265 				sbi->s_want_extra_isize = v;
4266 		}
4267 	}
4268 
4269 	if (sbi->s_es->s_mount_opts[0]) {
4270 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4271 					      sizeof(sbi->s_es->s_mount_opts),
4272 					      GFP_KERNEL);
4273 		if (!s_mount_opts)
4274 			goto failed_mount;
4275 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
4276 				   &journal_ioprio, 0)) {
4277 			ext4_msg(sb, KERN_WARNING,
4278 				 "failed to parse options in superblock: %s",
4279 				 s_mount_opts);
4280 		}
4281 		kfree(s_mount_opts);
4282 	}
4283 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4284 	if (!parse_options((char *) data, sb, &journal_devnum,
4285 			   &journal_ioprio, 0))
4286 		goto failed_mount;
4287 
4288 #ifdef CONFIG_UNICODE
4289 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4290 		const struct ext4_sb_encodings *encoding_info;
4291 		struct unicode_map *encoding;
4292 		__u16 encoding_flags;
4293 
4294 		if (ext4_has_feature_encrypt(sb)) {
4295 			ext4_msg(sb, KERN_ERR,
4296 				 "Can't mount with encoding and encryption");
4297 			goto failed_mount;
4298 		}
4299 
4300 		if (ext4_sb_read_encoding(es, &encoding_info,
4301 					  &encoding_flags)) {
4302 			ext4_msg(sb, KERN_ERR,
4303 				 "Encoding requested by superblock is unknown");
4304 			goto failed_mount;
4305 		}
4306 
4307 		encoding = utf8_load(encoding_info->version);
4308 		if (IS_ERR(encoding)) {
4309 			ext4_msg(sb, KERN_ERR,
4310 				 "can't mount with superblock charset: %s-%s "
4311 				 "not supported by the kernel. flags: 0x%x.",
4312 				 encoding_info->name, encoding_info->version,
4313 				 encoding_flags);
4314 			goto failed_mount;
4315 		}
4316 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4317 			 "%s-%s with flags 0x%hx", encoding_info->name,
4318 			 encoding_info->version?:"\b", encoding_flags);
4319 
4320 		sb->s_encoding = encoding;
4321 		sb->s_encoding_flags = encoding_flags;
4322 	}
4323 #endif
4324 
4325 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4326 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4327 		/* can't mount with both data=journal and dioread_nolock. */
4328 		clear_opt(sb, DIOREAD_NOLOCK);
4329 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4330 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4331 			ext4_msg(sb, KERN_ERR, "can't mount with "
4332 				 "both data=journal and delalloc");
4333 			goto failed_mount;
4334 		}
4335 		if (test_opt(sb, DAX_ALWAYS)) {
4336 			ext4_msg(sb, KERN_ERR, "can't mount with "
4337 				 "both data=journal and dax");
4338 			goto failed_mount;
4339 		}
4340 		if (ext4_has_feature_encrypt(sb)) {
4341 			ext4_msg(sb, KERN_WARNING,
4342 				 "encrypted files will use data=ordered "
4343 				 "instead of data journaling mode");
4344 		}
4345 		if (test_opt(sb, DELALLOC))
4346 			clear_opt(sb, DELALLOC);
4347 	} else {
4348 		sb->s_iflags |= SB_I_CGROUPWB;
4349 	}
4350 
4351 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4352 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4353 
4354 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4355 	    (ext4_has_compat_features(sb) ||
4356 	     ext4_has_ro_compat_features(sb) ||
4357 	     ext4_has_incompat_features(sb)))
4358 		ext4_msg(sb, KERN_WARNING,
4359 		       "feature flags set on rev 0 fs, "
4360 		       "running e2fsck is recommended");
4361 
4362 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4363 		set_opt2(sb, HURD_COMPAT);
4364 		if (ext4_has_feature_64bit(sb)) {
4365 			ext4_msg(sb, KERN_ERR,
4366 				 "The Hurd can't support 64-bit file systems");
4367 			goto failed_mount;
4368 		}
4369 
4370 		/*
4371 		 * ea_inode feature uses l_i_version field which is not
4372 		 * available in HURD_COMPAT mode.
4373 		 */
4374 		if (ext4_has_feature_ea_inode(sb)) {
4375 			ext4_msg(sb, KERN_ERR,
4376 				 "ea_inode feature is not supported for Hurd");
4377 			goto failed_mount;
4378 		}
4379 	}
4380 
4381 	if (IS_EXT2_SB(sb)) {
4382 		if (ext2_feature_set_ok(sb))
4383 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4384 				 "using the ext4 subsystem");
4385 		else {
4386 			/*
4387 			 * If we're probing be silent, if this looks like
4388 			 * it's actually an ext[34] filesystem.
4389 			 */
4390 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4391 				goto failed_mount;
4392 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4393 				 "to feature incompatibilities");
4394 			goto failed_mount;
4395 		}
4396 	}
4397 
4398 	if (IS_EXT3_SB(sb)) {
4399 		if (ext3_feature_set_ok(sb))
4400 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4401 				 "using the ext4 subsystem");
4402 		else {
4403 			/*
4404 			 * If we're probing be silent, if this looks like
4405 			 * it's actually an ext4 filesystem.
4406 			 */
4407 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4408 				goto failed_mount;
4409 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4410 				 "to feature incompatibilities");
4411 			goto failed_mount;
4412 		}
4413 	}
4414 
4415 	/*
4416 	 * Check feature flags regardless of the revision level, since we
4417 	 * previously didn't change the revision level when setting the flags,
4418 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4419 	 */
4420 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4421 		goto failed_mount;
4422 
4423 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4424 		ext4_msg(sb, KERN_ERR,
4425 			 "Number of reserved GDT blocks insanely large: %d",
4426 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4427 		goto failed_mount;
4428 	}
4429 
4430 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4431 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4432 
4433 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4434 		if (ext4_has_feature_inline_data(sb)) {
4435 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4436 					" that may contain inline data");
4437 			goto failed_mount;
4438 		}
4439 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4440 			ext4_msg(sb, KERN_ERR,
4441 				"DAX unsupported by block device.");
4442 			goto failed_mount;
4443 		}
4444 	}
4445 
4446 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4447 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4448 			 es->s_encryption_level);
4449 		goto failed_mount;
4450 	}
4451 
4452 	if (sb->s_blocksize != blocksize) {
4453 		/* Validate the filesystem blocksize */
4454 		if (!sb_set_blocksize(sb, blocksize)) {
4455 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4456 					blocksize);
4457 			goto failed_mount;
4458 		}
4459 
4460 		brelse(bh);
4461 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4462 		offset = do_div(logical_sb_block, blocksize);
4463 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4464 		if (IS_ERR(bh)) {
4465 			ext4_msg(sb, KERN_ERR,
4466 			       "Can't read superblock on 2nd try");
4467 			ret = PTR_ERR(bh);
4468 			bh = NULL;
4469 			goto failed_mount;
4470 		}
4471 		es = (struct ext4_super_block *)(bh->b_data + offset);
4472 		sbi->s_es = es;
4473 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4474 			ext4_msg(sb, KERN_ERR,
4475 			       "Magic mismatch, very weird!");
4476 			goto failed_mount;
4477 		}
4478 	}
4479 
4480 	has_huge_files = ext4_has_feature_huge_file(sb);
4481 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4482 						      has_huge_files);
4483 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4484 
4485 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4486 	if (ext4_has_feature_64bit(sb)) {
4487 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4488 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4489 		    !is_power_of_2(sbi->s_desc_size)) {
4490 			ext4_msg(sb, KERN_ERR,
4491 			       "unsupported descriptor size %lu",
4492 			       sbi->s_desc_size);
4493 			goto failed_mount;
4494 		}
4495 	} else
4496 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4497 
4498 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4499 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4500 
4501 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4502 	if (sbi->s_inodes_per_block == 0)
4503 		goto cantfind_ext4;
4504 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4505 	    sbi->s_inodes_per_group > blocksize * 8) {
4506 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4507 			 sbi->s_inodes_per_group);
4508 		goto failed_mount;
4509 	}
4510 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4511 					sbi->s_inodes_per_block;
4512 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4513 	sbi->s_sbh = bh;
4514 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4515 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4516 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4517 
4518 	for (i = 0; i < 4; i++)
4519 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4520 	sbi->s_def_hash_version = es->s_def_hash_version;
4521 	if (ext4_has_feature_dir_index(sb)) {
4522 		i = le32_to_cpu(es->s_flags);
4523 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4524 			sbi->s_hash_unsigned = 3;
4525 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4526 #ifdef __CHAR_UNSIGNED__
4527 			if (!sb_rdonly(sb))
4528 				es->s_flags |=
4529 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4530 			sbi->s_hash_unsigned = 3;
4531 #else
4532 			if (!sb_rdonly(sb))
4533 				es->s_flags |=
4534 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4535 #endif
4536 		}
4537 	}
4538 
4539 	/* Handle clustersize */
4540 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4541 	if (ext4_has_feature_bigalloc(sb)) {
4542 		if (clustersize < blocksize) {
4543 			ext4_msg(sb, KERN_ERR,
4544 				 "cluster size (%d) smaller than "
4545 				 "block size (%d)", clustersize, blocksize);
4546 			goto failed_mount;
4547 		}
4548 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4549 			le32_to_cpu(es->s_log_block_size);
4550 		sbi->s_clusters_per_group =
4551 			le32_to_cpu(es->s_clusters_per_group);
4552 		if (sbi->s_clusters_per_group > blocksize * 8) {
4553 			ext4_msg(sb, KERN_ERR,
4554 				 "#clusters per group too big: %lu",
4555 				 sbi->s_clusters_per_group);
4556 			goto failed_mount;
4557 		}
4558 		if (sbi->s_blocks_per_group !=
4559 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4560 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4561 				 "clusters per group (%lu) inconsistent",
4562 				 sbi->s_blocks_per_group,
4563 				 sbi->s_clusters_per_group);
4564 			goto failed_mount;
4565 		}
4566 	} else {
4567 		if (clustersize != blocksize) {
4568 			ext4_msg(sb, KERN_ERR,
4569 				 "fragment/cluster size (%d) != "
4570 				 "block size (%d)", clustersize, blocksize);
4571 			goto failed_mount;
4572 		}
4573 		if (sbi->s_blocks_per_group > blocksize * 8) {
4574 			ext4_msg(sb, KERN_ERR,
4575 				 "#blocks per group too big: %lu",
4576 				 sbi->s_blocks_per_group);
4577 			goto failed_mount;
4578 		}
4579 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4580 		sbi->s_cluster_bits = 0;
4581 	}
4582 	sbi->s_cluster_ratio = clustersize / blocksize;
4583 
4584 	/* Do we have standard group size of clustersize * 8 blocks ? */
4585 	if (sbi->s_blocks_per_group == clustersize << 3)
4586 		set_opt2(sb, STD_GROUP_SIZE);
4587 
4588 	/*
4589 	 * Test whether we have more sectors than will fit in sector_t,
4590 	 * and whether the max offset is addressable by the page cache.
4591 	 */
4592 	err = generic_check_addressable(sb->s_blocksize_bits,
4593 					ext4_blocks_count(es));
4594 	if (err) {
4595 		ext4_msg(sb, KERN_ERR, "filesystem"
4596 			 " too large to mount safely on this system");
4597 		goto failed_mount;
4598 	}
4599 
4600 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4601 		goto cantfind_ext4;
4602 
4603 	/* check blocks count against device size */
4604 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4605 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4606 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4607 		       "exceeds size of device (%llu blocks)",
4608 		       ext4_blocks_count(es), blocks_count);
4609 		goto failed_mount;
4610 	}
4611 
4612 	/*
4613 	 * It makes no sense for the first data block to be beyond the end
4614 	 * of the filesystem.
4615 	 */
4616 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4617 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4618 			 "block %u is beyond end of filesystem (%llu)",
4619 			 le32_to_cpu(es->s_first_data_block),
4620 			 ext4_blocks_count(es));
4621 		goto failed_mount;
4622 	}
4623 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4624 	    (sbi->s_cluster_ratio == 1)) {
4625 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4626 			 "block is 0 with a 1k block and cluster size");
4627 		goto failed_mount;
4628 	}
4629 
4630 	blocks_count = (ext4_blocks_count(es) -
4631 			le32_to_cpu(es->s_first_data_block) +
4632 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4633 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4634 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4635 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4636 		       "(block count %llu, first data block %u, "
4637 		       "blocks per group %lu)", blocks_count,
4638 		       ext4_blocks_count(es),
4639 		       le32_to_cpu(es->s_first_data_block),
4640 		       EXT4_BLOCKS_PER_GROUP(sb));
4641 		goto failed_mount;
4642 	}
4643 	sbi->s_groups_count = blocks_count;
4644 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4645 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4646 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4647 	    le32_to_cpu(es->s_inodes_count)) {
4648 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4649 			 le32_to_cpu(es->s_inodes_count),
4650 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4651 		ret = -EINVAL;
4652 		goto failed_mount;
4653 	}
4654 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4655 		   EXT4_DESC_PER_BLOCK(sb);
4656 	if (ext4_has_feature_meta_bg(sb)) {
4657 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4658 			ext4_msg(sb, KERN_WARNING,
4659 				 "first meta block group too large: %u "
4660 				 "(group descriptor block count %u)",
4661 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4662 			goto failed_mount;
4663 		}
4664 	}
4665 	rcu_assign_pointer(sbi->s_group_desc,
4666 			   kvmalloc_array(db_count,
4667 					  sizeof(struct buffer_head *),
4668 					  GFP_KERNEL));
4669 	if (sbi->s_group_desc == NULL) {
4670 		ext4_msg(sb, KERN_ERR, "not enough memory");
4671 		ret = -ENOMEM;
4672 		goto failed_mount;
4673 	}
4674 
4675 	bgl_lock_init(sbi->s_blockgroup_lock);
4676 
4677 	/* Pre-read the descriptors into the buffer cache */
4678 	for (i = 0; i < db_count; i++) {
4679 		block = descriptor_loc(sb, logical_sb_block, i);
4680 		ext4_sb_breadahead_unmovable(sb, block);
4681 	}
4682 
4683 	for (i = 0; i < db_count; i++) {
4684 		struct buffer_head *bh;
4685 
4686 		block = descriptor_loc(sb, logical_sb_block, i);
4687 		bh = ext4_sb_bread_unmovable(sb, block);
4688 		if (IS_ERR(bh)) {
4689 			ext4_msg(sb, KERN_ERR,
4690 			       "can't read group descriptor %d", i);
4691 			db_count = i;
4692 			ret = PTR_ERR(bh);
4693 			goto failed_mount2;
4694 		}
4695 		rcu_read_lock();
4696 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4697 		rcu_read_unlock();
4698 	}
4699 	sbi->s_gdb_count = db_count;
4700 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4701 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4702 		ret = -EFSCORRUPTED;
4703 		goto failed_mount2;
4704 	}
4705 
4706 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4707 	spin_lock_init(&sbi->s_error_lock);
4708 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
4709 
4710 	/* Register extent status tree shrinker */
4711 	if (ext4_es_register_shrinker(sbi))
4712 		goto failed_mount3;
4713 
4714 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4715 	sbi->s_extent_max_zeroout_kb = 32;
4716 
4717 	/*
4718 	 * set up enough so that it can read an inode
4719 	 */
4720 	sb->s_op = &ext4_sops;
4721 	sb->s_export_op = &ext4_export_ops;
4722 	sb->s_xattr = ext4_xattr_handlers;
4723 #ifdef CONFIG_FS_ENCRYPTION
4724 	sb->s_cop = &ext4_cryptops;
4725 #endif
4726 #ifdef CONFIG_FS_VERITY
4727 	sb->s_vop = &ext4_verityops;
4728 #endif
4729 #ifdef CONFIG_QUOTA
4730 	sb->dq_op = &ext4_quota_operations;
4731 	if (ext4_has_feature_quota(sb))
4732 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4733 	else
4734 		sb->s_qcop = &ext4_qctl_operations;
4735 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4736 #endif
4737 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4738 
4739 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4740 	mutex_init(&sbi->s_orphan_lock);
4741 
4742 	/* Initialize fast commit stuff */
4743 	atomic_set(&sbi->s_fc_subtid, 0);
4744 	atomic_set(&sbi->s_fc_ineligible_updates, 0);
4745 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4746 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4747 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4748 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4749 	sbi->s_fc_bytes = 0;
4750 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4751 	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
4752 	spin_lock_init(&sbi->s_fc_lock);
4753 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4754 	sbi->s_fc_replay_state.fc_regions = NULL;
4755 	sbi->s_fc_replay_state.fc_regions_size = 0;
4756 	sbi->s_fc_replay_state.fc_regions_used = 0;
4757 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4758 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4759 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4760 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4761 
4762 	sb->s_root = NULL;
4763 
4764 	needs_recovery = (es->s_last_orphan != 0 ||
4765 			  ext4_has_feature_journal_needs_recovery(sb));
4766 
4767 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4768 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4769 			goto failed_mount3a;
4770 
4771 	/*
4772 	 * The first inode we look at is the journal inode.  Don't try
4773 	 * root first: it may be modified in the journal!
4774 	 */
4775 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4776 		err = ext4_load_journal(sb, es, journal_devnum);
4777 		if (err)
4778 			goto failed_mount3a;
4779 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4780 		   ext4_has_feature_journal_needs_recovery(sb)) {
4781 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4782 		       "suppressed and not mounted read-only");
4783 		goto failed_mount_wq;
4784 	} else {
4785 		/* Nojournal mode, all journal mount options are illegal */
4786 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4787 			ext4_msg(sb, KERN_ERR, "can't mount with "
4788 				 "journal_checksum, fs mounted w/o journal");
4789 			goto failed_mount_wq;
4790 		}
4791 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4792 			ext4_msg(sb, KERN_ERR, "can't mount with "
4793 				 "journal_async_commit, fs mounted w/o journal");
4794 			goto failed_mount_wq;
4795 		}
4796 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4797 			ext4_msg(sb, KERN_ERR, "can't mount with "
4798 				 "commit=%lu, fs mounted w/o journal",
4799 				 sbi->s_commit_interval / HZ);
4800 			goto failed_mount_wq;
4801 		}
4802 		if (EXT4_MOUNT_DATA_FLAGS &
4803 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4804 			ext4_msg(sb, KERN_ERR, "can't mount with "
4805 				 "data=, fs mounted w/o journal");
4806 			goto failed_mount_wq;
4807 		}
4808 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4809 		clear_opt(sb, JOURNAL_CHECKSUM);
4810 		clear_opt(sb, DATA_FLAGS);
4811 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4812 		sbi->s_journal = NULL;
4813 		needs_recovery = 0;
4814 		goto no_journal;
4815 	}
4816 
4817 	if (ext4_has_feature_64bit(sb) &&
4818 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4819 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4820 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4821 		goto failed_mount_wq;
4822 	}
4823 
4824 	if (!set_journal_csum_feature_set(sb)) {
4825 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4826 			 "feature set");
4827 		goto failed_mount_wq;
4828 	}
4829 
4830 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4831 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4832 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4833 		ext4_msg(sb, KERN_ERR,
4834 			"Failed to set fast commit journal feature");
4835 		goto failed_mount_wq;
4836 	}
4837 
4838 	/* We have now updated the journal if required, so we can
4839 	 * validate the data journaling mode. */
4840 	switch (test_opt(sb, DATA_FLAGS)) {
4841 	case 0:
4842 		/* No mode set, assume a default based on the journal
4843 		 * capabilities: ORDERED_DATA if the journal can
4844 		 * cope, else JOURNAL_DATA
4845 		 */
4846 		if (jbd2_journal_check_available_features
4847 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4848 			set_opt(sb, ORDERED_DATA);
4849 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4850 		} else {
4851 			set_opt(sb, JOURNAL_DATA);
4852 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4853 		}
4854 		break;
4855 
4856 	case EXT4_MOUNT_ORDERED_DATA:
4857 	case EXT4_MOUNT_WRITEBACK_DATA:
4858 		if (!jbd2_journal_check_available_features
4859 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4860 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4861 			       "requested data journaling mode");
4862 			goto failed_mount_wq;
4863 		}
4864 		break;
4865 	default:
4866 		break;
4867 	}
4868 
4869 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4870 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4871 		ext4_msg(sb, KERN_ERR, "can't mount with "
4872 			"journal_async_commit in data=ordered mode");
4873 		goto failed_mount_wq;
4874 	}
4875 
4876 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4877 
4878 	sbi->s_journal->j_submit_inode_data_buffers =
4879 		ext4_journal_submit_inode_data_buffers;
4880 	sbi->s_journal->j_finish_inode_data_buffers =
4881 		ext4_journal_finish_inode_data_buffers;
4882 
4883 no_journal:
4884 	if (!test_opt(sb, NO_MBCACHE)) {
4885 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4886 		if (!sbi->s_ea_block_cache) {
4887 			ext4_msg(sb, KERN_ERR,
4888 				 "Failed to create ea_block_cache");
4889 			goto failed_mount_wq;
4890 		}
4891 
4892 		if (ext4_has_feature_ea_inode(sb)) {
4893 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4894 			if (!sbi->s_ea_inode_cache) {
4895 				ext4_msg(sb, KERN_ERR,
4896 					 "Failed to create ea_inode_cache");
4897 				goto failed_mount_wq;
4898 			}
4899 		}
4900 	}
4901 
4902 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4903 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4904 		goto failed_mount_wq;
4905 	}
4906 
4907 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4908 	    !ext4_has_feature_encrypt(sb)) {
4909 		ext4_set_feature_encrypt(sb);
4910 		ext4_commit_super(sb);
4911 	}
4912 
4913 	/*
4914 	 * Get the # of file system overhead blocks from the
4915 	 * superblock if present.
4916 	 */
4917 	if (es->s_overhead_clusters)
4918 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4919 	else {
4920 		err = ext4_calculate_overhead(sb);
4921 		if (err)
4922 			goto failed_mount_wq;
4923 	}
4924 
4925 	/*
4926 	 * The maximum number of concurrent works can be high and
4927 	 * concurrency isn't really necessary.  Limit it to 1.
4928 	 */
4929 	EXT4_SB(sb)->rsv_conversion_wq =
4930 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4931 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4932 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4933 		ret = -ENOMEM;
4934 		goto failed_mount4;
4935 	}
4936 
4937 	/*
4938 	 * The jbd2_journal_load will have done any necessary log recovery,
4939 	 * so we can safely mount the rest of the filesystem now.
4940 	 */
4941 
4942 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4943 	if (IS_ERR(root)) {
4944 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4945 		ret = PTR_ERR(root);
4946 		root = NULL;
4947 		goto failed_mount4;
4948 	}
4949 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4950 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4951 		iput(root);
4952 		goto failed_mount4;
4953 	}
4954 
4955 	sb->s_root = d_make_root(root);
4956 	if (!sb->s_root) {
4957 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4958 		ret = -ENOMEM;
4959 		goto failed_mount4;
4960 	}
4961 
4962 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4963 	if (ret == -EROFS) {
4964 		sb->s_flags |= SB_RDONLY;
4965 		ret = 0;
4966 	} else if (ret)
4967 		goto failed_mount4a;
4968 
4969 	ext4_set_resv_clusters(sb);
4970 
4971 	if (test_opt(sb, BLOCK_VALIDITY)) {
4972 		err = ext4_setup_system_zone(sb);
4973 		if (err) {
4974 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
4975 				 "zone (%d)", err);
4976 			goto failed_mount4a;
4977 		}
4978 	}
4979 	ext4_fc_replay_cleanup(sb);
4980 
4981 	ext4_ext_init(sb);
4982 	err = ext4_mb_init(sb);
4983 	if (err) {
4984 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4985 			 err);
4986 		goto failed_mount5;
4987 	}
4988 
4989 	/*
4990 	 * We can only set up the journal commit callback once
4991 	 * mballoc is initialized
4992 	 */
4993 	if (sbi->s_journal)
4994 		sbi->s_journal->j_commit_callback =
4995 			ext4_journal_commit_callback;
4996 
4997 	block = ext4_count_free_clusters(sb);
4998 	ext4_free_blocks_count_set(sbi->s_es,
4999 				   EXT4_C2B(sbi, block));
5000 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5001 				  GFP_KERNEL);
5002 	if (!err) {
5003 		unsigned long freei = ext4_count_free_inodes(sb);
5004 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5005 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5006 					  GFP_KERNEL);
5007 	}
5008 	if (!err)
5009 		err = percpu_counter_init(&sbi->s_dirs_counter,
5010 					  ext4_count_dirs(sb), GFP_KERNEL);
5011 	if (!err)
5012 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5013 					  GFP_KERNEL);
5014 	if (!err)
5015 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5016 
5017 	if (err) {
5018 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5019 		goto failed_mount6;
5020 	}
5021 
5022 	if (ext4_has_feature_flex_bg(sb))
5023 		if (!ext4_fill_flex_info(sb)) {
5024 			ext4_msg(sb, KERN_ERR,
5025 			       "unable to initialize "
5026 			       "flex_bg meta info!");
5027 			goto failed_mount6;
5028 		}
5029 
5030 	err = ext4_register_li_request(sb, first_not_zeroed);
5031 	if (err)
5032 		goto failed_mount6;
5033 
5034 	err = ext4_register_sysfs(sb);
5035 	if (err)
5036 		goto failed_mount7;
5037 
5038 #ifdef CONFIG_QUOTA
5039 	/* Enable quota usage during mount. */
5040 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5041 		err = ext4_enable_quotas(sb);
5042 		if (err)
5043 			goto failed_mount8;
5044 	}
5045 #endif  /* CONFIG_QUOTA */
5046 
5047 	/*
5048 	 * Save the original bdev mapping's wb_err value which could be
5049 	 * used to detect the metadata async write error.
5050 	 */
5051 	spin_lock_init(&sbi->s_bdev_wb_lock);
5052 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5053 				 &sbi->s_bdev_wb_err);
5054 	sb->s_bdev->bd_super = sb;
5055 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5056 	ext4_orphan_cleanup(sb, es);
5057 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5058 	if (needs_recovery) {
5059 		ext4_msg(sb, KERN_INFO, "recovery complete");
5060 		err = ext4_mark_recovery_complete(sb, es);
5061 		if (err)
5062 			goto failed_mount8;
5063 	}
5064 	if (EXT4_SB(sb)->s_journal) {
5065 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5066 			descr = " journalled data mode";
5067 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5068 			descr = " ordered data mode";
5069 		else
5070 			descr = " writeback data mode";
5071 	} else
5072 		descr = "out journal";
5073 
5074 	if (test_opt(sb, DISCARD)) {
5075 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5076 		if (!blk_queue_discard(q))
5077 			ext4_msg(sb, KERN_WARNING,
5078 				 "mounting with \"discard\" option, but "
5079 				 "the device does not support discard");
5080 	}
5081 
5082 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5083 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5084 			 "Opts: %.*s%s%s. Quota mode: %s.", descr,
5085 			 (int) sizeof(sbi->s_es->s_mount_opts),
5086 			 sbi->s_es->s_mount_opts,
5087 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data,
5088 			 ext4_quota_mode(sb));
5089 
5090 	if (es->s_error_count)
5091 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5092 
5093 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5094 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5095 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5096 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5097 	atomic_set(&sbi->s_warning_count, 0);
5098 	atomic_set(&sbi->s_msg_count, 0);
5099 
5100 	kfree(orig_data);
5101 	return 0;
5102 
5103 cantfind_ext4:
5104 	if (!silent)
5105 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5106 	goto failed_mount;
5107 
5108 failed_mount8:
5109 	ext4_unregister_sysfs(sb);
5110 	kobject_put(&sbi->s_kobj);
5111 failed_mount7:
5112 	ext4_unregister_li_request(sb);
5113 failed_mount6:
5114 	ext4_mb_release(sb);
5115 	rcu_read_lock();
5116 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5117 	if (flex_groups) {
5118 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5119 			kvfree(flex_groups[i]);
5120 		kvfree(flex_groups);
5121 	}
5122 	rcu_read_unlock();
5123 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5124 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5125 	percpu_counter_destroy(&sbi->s_dirs_counter);
5126 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5127 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5128 failed_mount5:
5129 	ext4_ext_release(sb);
5130 	ext4_release_system_zone(sb);
5131 failed_mount4a:
5132 	dput(sb->s_root);
5133 	sb->s_root = NULL;
5134 failed_mount4:
5135 	ext4_msg(sb, KERN_ERR, "mount failed");
5136 	if (EXT4_SB(sb)->rsv_conversion_wq)
5137 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5138 failed_mount_wq:
5139 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5140 	sbi->s_ea_inode_cache = NULL;
5141 
5142 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5143 	sbi->s_ea_block_cache = NULL;
5144 
5145 	if (sbi->s_journal) {
5146 		jbd2_journal_destroy(sbi->s_journal);
5147 		sbi->s_journal = NULL;
5148 	}
5149 failed_mount3a:
5150 	ext4_es_unregister_shrinker(sbi);
5151 failed_mount3:
5152 	del_timer_sync(&sbi->s_err_report);
5153 	flush_work(&sbi->s_error_work);
5154 	if (sbi->s_mmp_tsk)
5155 		kthread_stop(sbi->s_mmp_tsk);
5156 failed_mount2:
5157 	rcu_read_lock();
5158 	group_desc = rcu_dereference(sbi->s_group_desc);
5159 	for (i = 0; i < db_count; i++)
5160 		brelse(group_desc[i]);
5161 	kvfree(group_desc);
5162 	rcu_read_unlock();
5163 failed_mount:
5164 	if (sbi->s_chksum_driver)
5165 		crypto_free_shash(sbi->s_chksum_driver);
5166 
5167 #ifdef CONFIG_UNICODE
5168 	utf8_unload(sb->s_encoding);
5169 #endif
5170 
5171 #ifdef CONFIG_QUOTA
5172 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5173 		kfree(get_qf_name(sb, sbi, i));
5174 #endif
5175 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5176 	ext4_blkdev_remove(sbi);
5177 	brelse(bh);
5178 out_fail:
5179 	sb->s_fs_info = NULL;
5180 	kfree(sbi->s_blockgroup_lock);
5181 out_free_base:
5182 	kfree(sbi);
5183 	kfree(orig_data);
5184 	fs_put_dax(dax_dev);
5185 	return err ? err : ret;
5186 }
5187 
5188 /*
5189  * Setup any per-fs journal parameters now.  We'll do this both on
5190  * initial mount, once the journal has been initialised but before we've
5191  * done any recovery; and again on any subsequent remount.
5192  */
5193 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5194 {
5195 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5196 
5197 	journal->j_commit_interval = sbi->s_commit_interval;
5198 	journal->j_min_batch_time = sbi->s_min_batch_time;
5199 	journal->j_max_batch_time = sbi->s_max_batch_time;
5200 	ext4_fc_init(sb, journal);
5201 
5202 	write_lock(&journal->j_state_lock);
5203 	if (test_opt(sb, BARRIER))
5204 		journal->j_flags |= JBD2_BARRIER;
5205 	else
5206 		journal->j_flags &= ~JBD2_BARRIER;
5207 	if (test_opt(sb, DATA_ERR_ABORT))
5208 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5209 	else
5210 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5211 	write_unlock(&journal->j_state_lock);
5212 }
5213 
5214 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5215 					     unsigned int journal_inum)
5216 {
5217 	struct inode *journal_inode;
5218 
5219 	/*
5220 	 * Test for the existence of a valid inode on disk.  Bad things
5221 	 * happen if we iget() an unused inode, as the subsequent iput()
5222 	 * will try to delete it.
5223 	 */
5224 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5225 	if (IS_ERR(journal_inode)) {
5226 		ext4_msg(sb, KERN_ERR, "no journal found");
5227 		return NULL;
5228 	}
5229 	if (!journal_inode->i_nlink) {
5230 		make_bad_inode(journal_inode);
5231 		iput(journal_inode);
5232 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5233 		return NULL;
5234 	}
5235 
5236 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5237 		  journal_inode, journal_inode->i_size);
5238 	if (!S_ISREG(journal_inode->i_mode)) {
5239 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5240 		iput(journal_inode);
5241 		return NULL;
5242 	}
5243 	return journal_inode;
5244 }
5245 
5246 static journal_t *ext4_get_journal(struct super_block *sb,
5247 				   unsigned int journal_inum)
5248 {
5249 	struct inode *journal_inode;
5250 	journal_t *journal;
5251 
5252 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5253 		return NULL;
5254 
5255 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5256 	if (!journal_inode)
5257 		return NULL;
5258 
5259 	journal = jbd2_journal_init_inode(journal_inode);
5260 	if (!journal) {
5261 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5262 		iput(journal_inode);
5263 		return NULL;
5264 	}
5265 	journal->j_private = sb;
5266 	ext4_init_journal_params(sb, journal);
5267 	return journal;
5268 }
5269 
5270 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5271 				       dev_t j_dev)
5272 {
5273 	struct buffer_head *bh;
5274 	journal_t *journal;
5275 	ext4_fsblk_t start;
5276 	ext4_fsblk_t len;
5277 	int hblock, blocksize;
5278 	ext4_fsblk_t sb_block;
5279 	unsigned long offset;
5280 	struct ext4_super_block *es;
5281 	struct block_device *bdev;
5282 
5283 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5284 		return NULL;
5285 
5286 	bdev = ext4_blkdev_get(j_dev, sb);
5287 	if (bdev == NULL)
5288 		return NULL;
5289 
5290 	blocksize = sb->s_blocksize;
5291 	hblock = bdev_logical_block_size(bdev);
5292 	if (blocksize < hblock) {
5293 		ext4_msg(sb, KERN_ERR,
5294 			"blocksize too small for journal device");
5295 		goto out_bdev;
5296 	}
5297 
5298 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5299 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5300 	set_blocksize(bdev, blocksize);
5301 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5302 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5303 		       "external journal");
5304 		goto out_bdev;
5305 	}
5306 
5307 	es = (struct ext4_super_block *) (bh->b_data + offset);
5308 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5309 	    !(le32_to_cpu(es->s_feature_incompat) &
5310 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5311 		ext4_msg(sb, KERN_ERR, "external journal has "
5312 					"bad superblock");
5313 		brelse(bh);
5314 		goto out_bdev;
5315 	}
5316 
5317 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5318 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5319 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5320 		ext4_msg(sb, KERN_ERR, "external journal has "
5321 				       "corrupt superblock");
5322 		brelse(bh);
5323 		goto out_bdev;
5324 	}
5325 
5326 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5327 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5328 		brelse(bh);
5329 		goto out_bdev;
5330 	}
5331 
5332 	len = ext4_blocks_count(es);
5333 	start = sb_block + 1;
5334 	brelse(bh);	/* we're done with the superblock */
5335 
5336 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5337 					start, len, blocksize);
5338 	if (!journal) {
5339 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5340 		goto out_bdev;
5341 	}
5342 	journal->j_private = sb;
5343 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5344 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5345 		goto out_journal;
5346 	}
5347 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5348 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5349 					"user (unsupported) - %d",
5350 			be32_to_cpu(journal->j_superblock->s_nr_users));
5351 		goto out_journal;
5352 	}
5353 	EXT4_SB(sb)->s_journal_bdev = bdev;
5354 	ext4_init_journal_params(sb, journal);
5355 	return journal;
5356 
5357 out_journal:
5358 	jbd2_journal_destroy(journal);
5359 out_bdev:
5360 	ext4_blkdev_put(bdev);
5361 	return NULL;
5362 }
5363 
5364 static int ext4_load_journal(struct super_block *sb,
5365 			     struct ext4_super_block *es,
5366 			     unsigned long journal_devnum)
5367 {
5368 	journal_t *journal;
5369 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5370 	dev_t journal_dev;
5371 	int err = 0;
5372 	int really_read_only;
5373 	int journal_dev_ro;
5374 
5375 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5376 		return -EFSCORRUPTED;
5377 
5378 	if (journal_devnum &&
5379 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5380 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5381 			"numbers have changed");
5382 		journal_dev = new_decode_dev(journal_devnum);
5383 	} else
5384 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5385 
5386 	if (journal_inum && journal_dev) {
5387 		ext4_msg(sb, KERN_ERR,
5388 			 "filesystem has both journal inode and journal device!");
5389 		return -EINVAL;
5390 	}
5391 
5392 	if (journal_inum) {
5393 		journal = ext4_get_journal(sb, journal_inum);
5394 		if (!journal)
5395 			return -EINVAL;
5396 	} else {
5397 		journal = ext4_get_dev_journal(sb, journal_dev);
5398 		if (!journal)
5399 			return -EINVAL;
5400 	}
5401 
5402 	journal_dev_ro = bdev_read_only(journal->j_dev);
5403 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5404 
5405 	if (journal_dev_ro && !sb_rdonly(sb)) {
5406 		ext4_msg(sb, KERN_ERR,
5407 			 "journal device read-only, try mounting with '-o ro'");
5408 		err = -EROFS;
5409 		goto err_out;
5410 	}
5411 
5412 	/*
5413 	 * Are we loading a blank journal or performing recovery after a
5414 	 * crash?  For recovery, we need to check in advance whether we
5415 	 * can get read-write access to the device.
5416 	 */
5417 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5418 		if (sb_rdonly(sb)) {
5419 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5420 					"required on readonly filesystem");
5421 			if (really_read_only) {
5422 				ext4_msg(sb, KERN_ERR, "write access "
5423 					"unavailable, cannot proceed "
5424 					"(try mounting with noload)");
5425 				err = -EROFS;
5426 				goto err_out;
5427 			}
5428 			ext4_msg(sb, KERN_INFO, "write access will "
5429 			       "be enabled during recovery");
5430 		}
5431 	}
5432 
5433 	if (!(journal->j_flags & JBD2_BARRIER))
5434 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5435 
5436 	if (!ext4_has_feature_journal_needs_recovery(sb))
5437 		err = jbd2_journal_wipe(journal, !really_read_only);
5438 	if (!err) {
5439 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5440 		if (save)
5441 			memcpy(save, ((char *) es) +
5442 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5443 		err = jbd2_journal_load(journal);
5444 		if (save)
5445 			memcpy(((char *) es) + EXT4_S_ERR_START,
5446 			       save, EXT4_S_ERR_LEN);
5447 		kfree(save);
5448 	}
5449 
5450 	if (err) {
5451 		ext4_msg(sb, KERN_ERR, "error loading journal");
5452 		goto err_out;
5453 	}
5454 
5455 	EXT4_SB(sb)->s_journal = journal;
5456 	err = ext4_clear_journal_err(sb, es);
5457 	if (err) {
5458 		EXT4_SB(sb)->s_journal = NULL;
5459 		jbd2_journal_destroy(journal);
5460 		return err;
5461 	}
5462 
5463 	if (!really_read_only && journal_devnum &&
5464 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5465 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5466 
5467 		/* Make sure we flush the recovery flag to disk. */
5468 		ext4_commit_super(sb);
5469 	}
5470 
5471 	return 0;
5472 
5473 err_out:
5474 	jbd2_journal_destroy(journal);
5475 	return err;
5476 }
5477 
5478 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5479 static void ext4_update_super(struct super_block *sb)
5480 {
5481 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5482 	struct ext4_super_block *es = sbi->s_es;
5483 	struct buffer_head *sbh = sbi->s_sbh;
5484 
5485 	lock_buffer(sbh);
5486 	/*
5487 	 * If the file system is mounted read-only, don't update the
5488 	 * superblock write time.  This avoids updating the superblock
5489 	 * write time when we are mounting the root file system
5490 	 * read/only but we need to replay the journal; at that point,
5491 	 * for people who are east of GMT and who make their clock
5492 	 * tick in localtime for Windows bug-for-bug compatibility,
5493 	 * the clock is set in the future, and this will cause e2fsck
5494 	 * to complain and force a full file system check.
5495 	 */
5496 	if (!(sb->s_flags & SB_RDONLY))
5497 		ext4_update_tstamp(es, s_wtime);
5498 	es->s_kbytes_written =
5499 		cpu_to_le64(sbi->s_kbytes_written +
5500 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5501 		      sbi->s_sectors_written_start) >> 1));
5502 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5503 		ext4_free_blocks_count_set(es,
5504 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5505 				&sbi->s_freeclusters_counter)));
5506 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5507 		es->s_free_inodes_count =
5508 			cpu_to_le32(percpu_counter_sum_positive(
5509 				&sbi->s_freeinodes_counter));
5510 	/* Copy error information to the on-disk superblock */
5511 	spin_lock(&sbi->s_error_lock);
5512 	if (sbi->s_add_error_count > 0) {
5513 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5514 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5515 			__ext4_update_tstamp(&es->s_first_error_time,
5516 					     &es->s_first_error_time_hi,
5517 					     sbi->s_first_error_time);
5518 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5519 				sizeof(es->s_first_error_func));
5520 			es->s_first_error_line =
5521 				cpu_to_le32(sbi->s_first_error_line);
5522 			es->s_first_error_ino =
5523 				cpu_to_le32(sbi->s_first_error_ino);
5524 			es->s_first_error_block =
5525 				cpu_to_le64(sbi->s_first_error_block);
5526 			es->s_first_error_errcode =
5527 				ext4_errno_to_code(sbi->s_first_error_code);
5528 		}
5529 		__ext4_update_tstamp(&es->s_last_error_time,
5530 				     &es->s_last_error_time_hi,
5531 				     sbi->s_last_error_time);
5532 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5533 			sizeof(es->s_last_error_func));
5534 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5535 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5536 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5537 		es->s_last_error_errcode =
5538 				ext4_errno_to_code(sbi->s_last_error_code);
5539 		/*
5540 		 * Start the daily error reporting function if it hasn't been
5541 		 * started already
5542 		 */
5543 		if (!es->s_error_count)
5544 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5545 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5546 		sbi->s_add_error_count = 0;
5547 	}
5548 	spin_unlock(&sbi->s_error_lock);
5549 
5550 	ext4_superblock_csum_set(sb);
5551 	unlock_buffer(sbh);
5552 }
5553 
5554 static int ext4_commit_super(struct super_block *sb)
5555 {
5556 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5557 	int error = 0;
5558 
5559 	if (!sbh || block_device_ejected(sb))
5560 		return error;
5561 
5562 	ext4_update_super(sb);
5563 
5564 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5565 		/*
5566 		 * Oh, dear.  A previous attempt to write the
5567 		 * superblock failed.  This could happen because the
5568 		 * USB device was yanked out.  Or it could happen to
5569 		 * be a transient write error and maybe the block will
5570 		 * be remapped.  Nothing we can do but to retry the
5571 		 * write and hope for the best.
5572 		 */
5573 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5574 		       "superblock detected");
5575 		clear_buffer_write_io_error(sbh);
5576 		set_buffer_uptodate(sbh);
5577 	}
5578 	BUFFER_TRACE(sbh, "marking dirty");
5579 	mark_buffer_dirty(sbh);
5580 	error = __sync_dirty_buffer(sbh,
5581 		REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5582 	if (buffer_write_io_error(sbh)) {
5583 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
5584 		       "superblock");
5585 		clear_buffer_write_io_error(sbh);
5586 		set_buffer_uptodate(sbh);
5587 	}
5588 	return error;
5589 }
5590 
5591 /*
5592  * Have we just finished recovery?  If so, and if we are mounting (or
5593  * remounting) the filesystem readonly, then we will end up with a
5594  * consistent fs on disk.  Record that fact.
5595  */
5596 static int ext4_mark_recovery_complete(struct super_block *sb,
5597 				       struct ext4_super_block *es)
5598 {
5599 	int err;
5600 	journal_t *journal = EXT4_SB(sb)->s_journal;
5601 
5602 	if (!ext4_has_feature_journal(sb)) {
5603 		if (journal != NULL) {
5604 			ext4_error(sb, "Journal got removed while the fs was "
5605 				   "mounted!");
5606 			return -EFSCORRUPTED;
5607 		}
5608 		return 0;
5609 	}
5610 	jbd2_journal_lock_updates(journal);
5611 	err = jbd2_journal_flush(journal);
5612 	if (err < 0)
5613 		goto out;
5614 
5615 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5616 		ext4_clear_feature_journal_needs_recovery(sb);
5617 		ext4_commit_super(sb);
5618 	}
5619 out:
5620 	jbd2_journal_unlock_updates(journal);
5621 	return err;
5622 }
5623 
5624 /*
5625  * If we are mounting (or read-write remounting) a filesystem whose journal
5626  * has recorded an error from a previous lifetime, move that error to the
5627  * main filesystem now.
5628  */
5629 static int ext4_clear_journal_err(struct super_block *sb,
5630 				   struct ext4_super_block *es)
5631 {
5632 	journal_t *journal;
5633 	int j_errno;
5634 	const char *errstr;
5635 
5636 	if (!ext4_has_feature_journal(sb)) {
5637 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5638 		return -EFSCORRUPTED;
5639 	}
5640 
5641 	journal = EXT4_SB(sb)->s_journal;
5642 
5643 	/*
5644 	 * Now check for any error status which may have been recorded in the
5645 	 * journal by a prior ext4_error() or ext4_abort()
5646 	 */
5647 
5648 	j_errno = jbd2_journal_errno(journal);
5649 	if (j_errno) {
5650 		char nbuf[16];
5651 
5652 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5653 		ext4_warning(sb, "Filesystem error recorded "
5654 			     "from previous mount: %s", errstr);
5655 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5656 
5657 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5658 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5659 		ext4_commit_super(sb);
5660 
5661 		jbd2_journal_clear_err(journal);
5662 		jbd2_journal_update_sb_errno(journal);
5663 	}
5664 	return 0;
5665 }
5666 
5667 /*
5668  * Force the running and committing transactions to commit,
5669  * and wait on the commit.
5670  */
5671 int ext4_force_commit(struct super_block *sb)
5672 {
5673 	journal_t *journal;
5674 
5675 	if (sb_rdonly(sb))
5676 		return 0;
5677 
5678 	journal = EXT4_SB(sb)->s_journal;
5679 	return ext4_journal_force_commit(journal);
5680 }
5681 
5682 static int ext4_sync_fs(struct super_block *sb, int wait)
5683 {
5684 	int ret = 0;
5685 	tid_t target;
5686 	bool needs_barrier = false;
5687 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5688 
5689 	if (unlikely(ext4_forced_shutdown(sbi)))
5690 		return 0;
5691 
5692 	trace_ext4_sync_fs(sb, wait);
5693 	flush_workqueue(sbi->rsv_conversion_wq);
5694 	/*
5695 	 * Writeback quota in non-journalled quota case - journalled quota has
5696 	 * no dirty dquots
5697 	 */
5698 	dquot_writeback_dquots(sb, -1);
5699 	/*
5700 	 * Data writeback is possible w/o journal transaction, so barrier must
5701 	 * being sent at the end of the function. But we can skip it if
5702 	 * transaction_commit will do it for us.
5703 	 */
5704 	if (sbi->s_journal) {
5705 		target = jbd2_get_latest_transaction(sbi->s_journal);
5706 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5707 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5708 			needs_barrier = true;
5709 
5710 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5711 			if (wait)
5712 				ret = jbd2_log_wait_commit(sbi->s_journal,
5713 							   target);
5714 		}
5715 	} else if (wait && test_opt(sb, BARRIER))
5716 		needs_barrier = true;
5717 	if (needs_barrier) {
5718 		int err;
5719 		err = blkdev_issue_flush(sb->s_bdev);
5720 		if (!ret)
5721 			ret = err;
5722 	}
5723 
5724 	return ret;
5725 }
5726 
5727 /*
5728  * LVM calls this function before a (read-only) snapshot is created.  This
5729  * gives us a chance to flush the journal completely and mark the fs clean.
5730  *
5731  * Note that only this function cannot bring a filesystem to be in a clean
5732  * state independently. It relies on upper layer to stop all data & metadata
5733  * modifications.
5734  */
5735 static int ext4_freeze(struct super_block *sb)
5736 {
5737 	int error = 0;
5738 	journal_t *journal;
5739 
5740 	if (sb_rdonly(sb))
5741 		return 0;
5742 
5743 	journal = EXT4_SB(sb)->s_journal;
5744 
5745 	if (journal) {
5746 		/* Now we set up the journal barrier. */
5747 		jbd2_journal_lock_updates(journal);
5748 
5749 		/*
5750 		 * Don't clear the needs_recovery flag if we failed to
5751 		 * flush the journal.
5752 		 */
5753 		error = jbd2_journal_flush(journal);
5754 		if (error < 0)
5755 			goto out;
5756 
5757 		/* Journal blocked and flushed, clear needs_recovery flag. */
5758 		ext4_clear_feature_journal_needs_recovery(sb);
5759 	}
5760 
5761 	error = ext4_commit_super(sb);
5762 out:
5763 	if (journal)
5764 		/* we rely on upper layer to stop further updates */
5765 		jbd2_journal_unlock_updates(journal);
5766 	return error;
5767 }
5768 
5769 /*
5770  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5771  * flag here, even though the filesystem is not technically dirty yet.
5772  */
5773 static int ext4_unfreeze(struct super_block *sb)
5774 {
5775 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5776 		return 0;
5777 
5778 	if (EXT4_SB(sb)->s_journal) {
5779 		/* Reset the needs_recovery flag before the fs is unlocked. */
5780 		ext4_set_feature_journal_needs_recovery(sb);
5781 	}
5782 
5783 	ext4_commit_super(sb);
5784 	return 0;
5785 }
5786 
5787 /*
5788  * Structure to save mount options for ext4_remount's benefit
5789  */
5790 struct ext4_mount_options {
5791 	unsigned long s_mount_opt;
5792 	unsigned long s_mount_opt2;
5793 	kuid_t s_resuid;
5794 	kgid_t s_resgid;
5795 	unsigned long s_commit_interval;
5796 	u32 s_min_batch_time, s_max_batch_time;
5797 #ifdef CONFIG_QUOTA
5798 	int s_jquota_fmt;
5799 	char *s_qf_names[EXT4_MAXQUOTAS];
5800 #endif
5801 };
5802 
5803 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5804 {
5805 	struct ext4_super_block *es;
5806 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5807 	unsigned long old_sb_flags, vfs_flags;
5808 	struct ext4_mount_options old_opts;
5809 	int enable_quota = 0;
5810 	ext4_group_t g;
5811 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5812 	int err = 0;
5813 #ifdef CONFIG_QUOTA
5814 	int i, j;
5815 	char *to_free[EXT4_MAXQUOTAS];
5816 #endif
5817 	char *orig_data = kstrdup(data, GFP_KERNEL);
5818 
5819 	if (data && !orig_data)
5820 		return -ENOMEM;
5821 
5822 	/* Store the original options */
5823 	old_sb_flags = sb->s_flags;
5824 	old_opts.s_mount_opt = sbi->s_mount_opt;
5825 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5826 	old_opts.s_resuid = sbi->s_resuid;
5827 	old_opts.s_resgid = sbi->s_resgid;
5828 	old_opts.s_commit_interval = sbi->s_commit_interval;
5829 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5830 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5831 #ifdef CONFIG_QUOTA
5832 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5833 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5834 		if (sbi->s_qf_names[i]) {
5835 			char *qf_name = get_qf_name(sb, sbi, i);
5836 
5837 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5838 			if (!old_opts.s_qf_names[i]) {
5839 				for (j = 0; j < i; j++)
5840 					kfree(old_opts.s_qf_names[j]);
5841 				kfree(orig_data);
5842 				return -ENOMEM;
5843 			}
5844 		} else
5845 			old_opts.s_qf_names[i] = NULL;
5846 #endif
5847 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5848 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5849 
5850 	/*
5851 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5852 	 * either way we need to make sure it matches in both *flags and
5853 	 * s_flags. Copy those selected flags from *flags to s_flags
5854 	 */
5855 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5856 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5857 
5858 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5859 		err = -EINVAL;
5860 		goto restore_opts;
5861 	}
5862 
5863 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5864 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5865 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5866 			 "during remount not supported; ignoring");
5867 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5868 	}
5869 
5870 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5871 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5872 			ext4_msg(sb, KERN_ERR, "can't mount with "
5873 				 "both data=journal and delalloc");
5874 			err = -EINVAL;
5875 			goto restore_opts;
5876 		}
5877 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5878 			ext4_msg(sb, KERN_ERR, "can't mount with "
5879 				 "both data=journal and dioread_nolock");
5880 			err = -EINVAL;
5881 			goto restore_opts;
5882 		}
5883 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5884 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5885 			ext4_msg(sb, KERN_ERR, "can't mount with "
5886 				"journal_async_commit in data=ordered mode");
5887 			err = -EINVAL;
5888 			goto restore_opts;
5889 		}
5890 	}
5891 
5892 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5893 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5894 		err = -EINVAL;
5895 		goto restore_opts;
5896 	}
5897 
5898 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5899 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5900 
5901 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5902 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5903 
5904 	es = sbi->s_es;
5905 
5906 	if (sbi->s_journal) {
5907 		ext4_init_journal_params(sb, sbi->s_journal);
5908 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5909 	}
5910 
5911 	/* Flush outstanding errors before changing fs state */
5912 	flush_work(&sbi->s_error_work);
5913 
5914 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5915 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
5916 			err = -EROFS;
5917 			goto restore_opts;
5918 		}
5919 
5920 		if (*flags & SB_RDONLY) {
5921 			err = sync_filesystem(sb);
5922 			if (err < 0)
5923 				goto restore_opts;
5924 			err = dquot_suspend(sb, -1);
5925 			if (err < 0)
5926 				goto restore_opts;
5927 
5928 			/*
5929 			 * First of all, the unconditional stuff we have to do
5930 			 * to disable replay of the journal when we next remount
5931 			 */
5932 			sb->s_flags |= SB_RDONLY;
5933 
5934 			/*
5935 			 * OK, test if we are remounting a valid rw partition
5936 			 * readonly, and if so set the rdonly flag and then
5937 			 * mark the partition as valid again.
5938 			 */
5939 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5940 			    (sbi->s_mount_state & EXT4_VALID_FS))
5941 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5942 
5943 			if (sbi->s_journal) {
5944 				/*
5945 				 * We let remount-ro finish even if marking fs
5946 				 * as clean failed...
5947 				 */
5948 				ext4_mark_recovery_complete(sb, es);
5949 			}
5950 			if (sbi->s_mmp_tsk)
5951 				kthread_stop(sbi->s_mmp_tsk);
5952 		} else {
5953 			/* Make sure we can mount this feature set readwrite */
5954 			if (ext4_has_feature_readonly(sb) ||
5955 			    !ext4_feature_set_ok(sb, 0)) {
5956 				err = -EROFS;
5957 				goto restore_opts;
5958 			}
5959 			/*
5960 			 * Make sure the group descriptor checksums
5961 			 * are sane.  If they aren't, refuse to remount r/w.
5962 			 */
5963 			for (g = 0; g < sbi->s_groups_count; g++) {
5964 				struct ext4_group_desc *gdp =
5965 					ext4_get_group_desc(sb, g, NULL);
5966 
5967 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5968 					ext4_msg(sb, KERN_ERR,
5969 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5970 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5971 					       le16_to_cpu(gdp->bg_checksum));
5972 					err = -EFSBADCRC;
5973 					goto restore_opts;
5974 				}
5975 			}
5976 
5977 			/*
5978 			 * If we have an unprocessed orphan list hanging
5979 			 * around from a previously readonly bdev mount,
5980 			 * require a full umount/remount for now.
5981 			 */
5982 			if (es->s_last_orphan) {
5983 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5984 				       "remount RDWR because of unprocessed "
5985 				       "orphan inode list.  Please "
5986 				       "umount/remount instead");
5987 				err = -EINVAL;
5988 				goto restore_opts;
5989 			}
5990 
5991 			/*
5992 			 * Mounting a RDONLY partition read-write, so reread
5993 			 * and store the current valid flag.  (It may have
5994 			 * been changed by e2fsck since we originally mounted
5995 			 * the partition.)
5996 			 */
5997 			if (sbi->s_journal) {
5998 				err = ext4_clear_journal_err(sb, es);
5999 				if (err)
6000 					goto restore_opts;
6001 			}
6002 			sbi->s_mount_state = le16_to_cpu(es->s_state);
6003 
6004 			err = ext4_setup_super(sb, es, 0);
6005 			if (err)
6006 				goto restore_opts;
6007 
6008 			sb->s_flags &= ~SB_RDONLY;
6009 			if (ext4_has_feature_mmp(sb))
6010 				if (ext4_multi_mount_protect(sb,
6011 						le64_to_cpu(es->s_mmp_block))) {
6012 					err = -EROFS;
6013 					goto restore_opts;
6014 				}
6015 			enable_quota = 1;
6016 		}
6017 	}
6018 
6019 	/*
6020 	 * Reinitialize lazy itable initialization thread based on
6021 	 * current settings
6022 	 */
6023 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6024 		ext4_unregister_li_request(sb);
6025 	else {
6026 		ext4_group_t first_not_zeroed;
6027 		first_not_zeroed = ext4_has_uninit_itable(sb);
6028 		ext4_register_li_request(sb, first_not_zeroed);
6029 	}
6030 
6031 	/*
6032 	 * Handle creation of system zone data early because it can fail.
6033 	 * Releasing of existing data is done when we are sure remount will
6034 	 * succeed.
6035 	 */
6036 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6037 		err = ext4_setup_system_zone(sb);
6038 		if (err)
6039 			goto restore_opts;
6040 	}
6041 
6042 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6043 		err = ext4_commit_super(sb);
6044 		if (err)
6045 			goto restore_opts;
6046 	}
6047 
6048 #ifdef CONFIG_QUOTA
6049 	/* Release old quota file names */
6050 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6051 		kfree(old_opts.s_qf_names[i]);
6052 	if (enable_quota) {
6053 		if (sb_any_quota_suspended(sb))
6054 			dquot_resume(sb, -1);
6055 		else if (ext4_has_feature_quota(sb)) {
6056 			err = ext4_enable_quotas(sb);
6057 			if (err)
6058 				goto restore_opts;
6059 		}
6060 	}
6061 #endif
6062 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6063 		ext4_release_system_zone(sb);
6064 
6065 	/*
6066 	 * Some options can be enabled by ext4 and/or by VFS mount flag
6067 	 * either way we need to make sure it matches in both *flags and
6068 	 * s_flags. Copy those selected flags from s_flags to *flags
6069 	 */
6070 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6071 
6072 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s. Quota mode: %s.",
6073 		 orig_data, ext4_quota_mode(sb));
6074 	kfree(orig_data);
6075 	return 0;
6076 
6077 restore_opts:
6078 	sb->s_flags = old_sb_flags;
6079 	sbi->s_mount_opt = old_opts.s_mount_opt;
6080 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6081 	sbi->s_resuid = old_opts.s_resuid;
6082 	sbi->s_resgid = old_opts.s_resgid;
6083 	sbi->s_commit_interval = old_opts.s_commit_interval;
6084 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6085 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6086 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6087 		ext4_release_system_zone(sb);
6088 #ifdef CONFIG_QUOTA
6089 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6090 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6091 		to_free[i] = get_qf_name(sb, sbi, i);
6092 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6093 	}
6094 	synchronize_rcu();
6095 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6096 		kfree(to_free[i]);
6097 #endif
6098 	kfree(orig_data);
6099 	return err;
6100 }
6101 
6102 #ifdef CONFIG_QUOTA
6103 static int ext4_statfs_project(struct super_block *sb,
6104 			       kprojid_t projid, struct kstatfs *buf)
6105 {
6106 	struct kqid qid;
6107 	struct dquot *dquot;
6108 	u64 limit;
6109 	u64 curblock;
6110 
6111 	qid = make_kqid_projid(projid);
6112 	dquot = dqget(sb, qid);
6113 	if (IS_ERR(dquot))
6114 		return PTR_ERR(dquot);
6115 	spin_lock(&dquot->dq_dqb_lock);
6116 
6117 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6118 			     dquot->dq_dqb.dqb_bhardlimit);
6119 	limit >>= sb->s_blocksize_bits;
6120 
6121 	if (limit && buf->f_blocks > limit) {
6122 		curblock = (dquot->dq_dqb.dqb_curspace +
6123 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6124 		buf->f_blocks = limit;
6125 		buf->f_bfree = buf->f_bavail =
6126 			(buf->f_blocks > curblock) ?
6127 			 (buf->f_blocks - curblock) : 0;
6128 	}
6129 
6130 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6131 			     dquot->dq_dqb.dqb_ihardlimit);
6132 	if (limit && buf->f_files > limit) {
6133 		buf->f_files = limit;
6134 		buf->f_ffree =
6135 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6136 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6137 	}
6138 
6139 	spin_unlock(&dquot->dq_dqb_lock);
6140 	dqput(dquot);
6141 	return 0;
6142 }
6143 #endif
6144 
6145 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6146 {
6147 	struct super_block *sb = dentry->d_sb;
6148 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6149 	struct ext4_super_block *es = sbi->s_es;
6150 	ext4_fsblk_t overhead = 0, resv_blocks;
6151 	u64 fsid;
6152 	s64 bfree;
6153 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6154 
6155 	if (!test_opt(sb, MINIX_DF))
6156 		overhead = sbi->s_overhead;
6157 
6158 	buf->f_type = EXT4_SUPER_MAGIC;
6159 	buf->f_bsize = sb->s_blocksize;
6160 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6161 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6162 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6163 	/* prevent underflow in case that few free space is available */
6164 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6165 	buf->f_bavail = buf->f_bfree -
6166 			(ext4_r_blocks_count(es) + resv_blocks);
6167 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6168 		buf->f_bavail = 0;
6169 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6170 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6171 	buf->f_namelen = EXT4_NAME_LEN;
6172 	fsid = le64_to_cpup((void *)es->s_uuid) ^
6173 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
6174 	buf->f_fsid = u64_to_fsid(fsid);
6175 
6176 #ifdef CONFIG_QUOTA
6177 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6178 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6179 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6180 #endif
6181 	return 0;
6182 }
6183 
6184 
6185 #ifdef CONFIG_QUOTA
6186 
6187 /*
6188  * Helper functions so that transaction is started before we acquire dqio_sem
6189  * to keep correct lock ordering of transaction > dqio_sem
6190  */
6191 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6192 {
6193 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6194 }
6195 
6196 static int ext4_write_dquot(struct dquot *dquot)
6197 {
6198 	int ret, err;
6199 	handle_t *handle;
6200 	struct inode *inode;
6201 
6202 	inode = dquot_to_inode(dquot);
6203 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6204 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6205 	if (IS_ERR(handle))
6206 		return PTR_ERR(handle);
6207 	ret = dquot_commit(dquot);
6208 	err = ext4_journal_stop(handle);
6209 	if (!ret)
6210 		ret = err;
6211 	return ret;
6212 }
6213 
6214 static int ext4_acquire_dquot(struct dquot *dquot)
6215 {
6216 	int ret, err;
6217 	handle_t *handle;
6218 
6219 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6220 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6221 	if (IS_ERR(handle))
6222 		return PTR_ERR(handle);
6223 	ret = dquot_acquire(dquot);
6224 	err = ext4_journal_stop(handle);
6225 	if (!ret)
6226 		ret = err;
6227 	return ret;
6228 }
6229 
6230 static int ext4_release_dquot(struct dquot *dquot)
6231 {
6232 	int ret, err;
6233 	handle_t *handle;
6234 
6235 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6236 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6237 	if (IS_ERR(handle)) {
6238 		/* Release dquot anyway to avoid endless cycle in dqput() */
6239 		dquot_release(dquot);
6240 		return PTR_ERR(handle);
6241 	}
6242 	ret = dquot_release(dquot);
6243 	err = ext4_journal_stop(handle);
6244 	if (!ret)
6245 		ret = err;
6246 	return ret;
6247 }
6248 
6249 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6250 {
6251 	struct super_block *sb = dquot->dq_sb;
6252 
6253 	if (ext4_is_quota_journalled(sb)) {
6254 		dquot_mark_dquot_dirty(dquot);
6255 		return ext4_write_dquot(dquot);
6256 	} else {
6257 		return dquot_mark_dquot_dirty(dquot);
6258 	}
6259 }
6260 
6261 static int ext4_write_info(struct super_block *sb, int type)
6262 {
6263 	int ret, err;
6264 	handle_t *handle;
6265 
6266 	/* Data block + inode block */
6267 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6268 	if (IS_ERR(handle))
6269 		return PTR_ERR(handle);
6270 	ret = dquot_commit_info(sb, type);
6271 	err = ext4_journal_stop(handle);
6272 	if (!ret)
6273 		ret = err;
6274 	return ret;
6275 }
6276 
6277 /*
6278  * Turn on quotas during mount time - we need to find
6279  * the quota file and such...
6280  */
6281 static int ext4_quota_on_mount(struct super_block *sb, int type)
6282 {
6283 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6284 					EXT4_SB(sb)->s_jquota_fmt, type);
6285 }
6286 
6287 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6288 {
6289 	struct ext4_inode_info *ei = EXT4_I(inode);
6290 
6291 	/* The first argument of lockdep_set_subclass has to be
6292 	 * *exactly* the same as the argument to init_rwsem() --- in
6293 	 * this case, in init_once() --- or lockdep gets unhappy
6294 	 * because the name of the lock is set using the
6295 	 * stringification of the argument to init_rwsem().
6296 	 */
6297 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6298 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6299 }
6300 
6301 /*
6302  * Standard function to be called on quota_on
6303  */
6304 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6305 			 const struct path *path)
6306 {
6307 	int err;
6308 
6309 	if (!test_opt(sb, QUOTA))
6310 		return -EINVAL;
6311 
6312 	/* Quotafile not on the same filesystem? */
6313 	if (path->dentry->d_sb != sb)
6314 		return -EXDEV;
6315 
6316 	/* Quota already enabled for this file? */
6317 	if (IS_NOQUOTA(d_inode(path->dentry)))
6318 		return -EBUSY;
6319 
6320 	/* Journaling quota? */
6321 	if (EXT4_SB(sb)->s_qf_names[type]) {
6322 		/* Quotafile not in fs root? */
6323 		if (path->dentry->d_parent != sb->s_root)
6324 			ext4_msg(sb, KERN_WARNING,
6325 				"Quota file not on filesystem root. "
6326 				"Journaled quota will not work");
6327 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6328 	} else {
6329 		/*
6330 		 * Clear the flag just in case mount options changed since
6331 		 * last time.
6332 		 */
6333 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6334 	}
6335 
6336 	/*
6337 	 * When we journal data on quota file, we have to flush journal to see
6338 	 * all updates to the file when we bypass pagecache...
6339 	 */
6340 	if (EXT4_SB(sb)->s_journal &&
6341 	    ext4_should_journal_data(d_inode(path->dentry))) {
6342 		/*
6343 		 * We don't need to lock updates but journal_flush() could
6344 		 * otherwise be livelocked...
6345 		 */
6346 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6347 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
6348 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6349 		if (err)
6350 			return err;
6351 	}
6352 
6353 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6354 	err = dquot_quota_on(sb, type, format_id, path);
6355 	if (err) {
6356 		lockdep_set_quota_inode(path->dentry->d_inode,
6357 					     I_DATA_SEM_NORMAL);
6358 	} else {
6359 		struct inode *inode = d_inode(path->dentry);
6360 		handle_t *handle;
6361 
6362 		/*
6363 		 * Set inode flags to prevent userspace from messing with quota
6364 		 * files. If this fails, we return success anyway since quotas
6365 		 * are already enabled and this is not a hard failure.
6366 		 */
6367 		inode_lock(inode);
6368 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6369 		if (IS_ERR(handle))
6370 			goto unlock_inode;
6371 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6372 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6373 				S_NOATIME | S_IMMUTABLE);
6374 		err = ext4_mark_inode_dirty(handle, inode);
6375 		ext4_journal_stop(handle);
6376 	unlock_inode:
6377 		inode_unlock(inode);
6378 	}
6379 	return err;
6380 }
6381 
6382 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6383 			     unsigned int flags)
6384 {
6385 	int err;
6386 	struct inode *qf_inode;
6387 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6388 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6389 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6390 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6391 	};
6392 
6393 	BUG_ON(!ext4_has_feature_quota(sb));
6394 
6395 	if (!qf_inums[type])
6396 		return -EPERM;
6397 
6398 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6399 	if (IS_ERR(qf_inode)) {
6400 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6401 		return PTR_ERR(qf_inode);
6402 	}
6403 
6404 	/* Don't account quota for quota files to avoid recursion */
6405 	qf_inode->i_flags |= S_NOQUOTA;
6406 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6407 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6408 	if (err)
6409 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6410 	iput(qf_inode);
6411 
6412 	return err;
6413 }
6414 
6415 /* Enable usage tracking for all quota types. */
6416 static int ext4_enable_quotas(struct super_block *sb)
6417 {
6418 	int type, err = 0;
6419 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6420 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6421 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6422 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6423 	};
6424 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6425 		test_opt(sb, USRQUOTA),
6426 		test_opt(sb, GRPQUOTA),
6427 		test_opt(sb, PRJQUOTA),
6428 	};
6429 
6430 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6431 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6432 		if (qf_inums[type]) {
6433 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6434 				DQUOT_USAGE_ENABLED |
6435 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6436 			if (err) {
6437 				ext4_warning(sb,
6438 					"Failed to enable quota tracking "
6439 					"(type=%d, err=%d). Please run "
6440 					"e2fsck to fix.", type, err);
6441 				for (type--; type >= 0; type--)
6442 					dquot_quota_off(sb, type);
6443 
6444 				return err;
6445 			}
6446 		}
6447 	}
6448 	return 0;
6449 }
6450 
6451 static int ext4_quota_off(struct super_block *sb, int type)
6452 {
6453 	struct inode *inode = sb_dqopt(sb)->files[type];
6454 	handle_t *handle;
6455 	int err;
6456 
6457 	/* Force all delayed allocation blocks to be allocated.
6458 	 * Caller already holds s_umount sem */
6459 	if (test_opt(sb, DELALLOC))
6460 		sync_filesystem(sb);
6461 
6462 	if (!inode || !igrab(inode))
6463 		goto out;
6464 
6465 	err = dquot_quota_off(sb, type);
6466 	if (err || ext4_has_feature_quota(sb))
6467 		goto out_put;
6468 
6469 	inode_lock(inode);
6470 	/*
6471 	 * Update modification times of quota files when userspace can
6472 	 * start looking at them. If we fail, we return success anyway since
6473 	 * this is not a hard failure and quotas are already disabled.
6474 	 */
6475 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6476 	if (IS_ERR(handle)) {
6477 		err = PTR_ERR(handle);
6478 		goto out_unlock;
6479 	}
6480 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6481 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6482 	inode->i_mtime = inode->i_ctime = current_time(inode);
6483 	err = ext4_mark_inode_dirty(handle, inode);
6484 	ext4_journal_stop(handle);
6485 out_unlock:
6486 	inode_unlock(inode);
6487 out_put:
6488 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6489 	iput(inode);
6490 	return err;
6491 out:
6492 	return dquot_quota_off(sb, type);
6493 }
6494 
6495 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6496  * acquiring the locks... As quota files are never truncated and quota code
6497  * itself serializes the operations (and no one else should touch the files)
6498  * we don't have to be afraid of races */
6499 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6500 			       size_t len, loff_t off)
6501 {
6502 	struct inode *inode = sb_dqopt(sb)->files[type];
6503 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6504 	int offset = off & (sb->s_blocksize - 1);
6505 	int tocopy;
6506 	size_t toread;
6507 	struct buffer_head *bh;
6508 	loff_t i_size = i_size_read(inode);
6509 
6510 	if (off > i_size)
6511 		return 0;
6512 	if (off+len > i_size)
6513 		len = i_size-off;
6514 	toread = len;
6515 	while (toread > 0) {
6516 		tocopy = sb->s_blocksize - offset < toread ?
6517 				sb->s_blocksize - offset : toread;
6518 		bh = ext4_bread(NULL, inode, blk, 0);
6519 		if (IS_ERR(bh))
6520 			return PTR_ERR(bh);
6521 		if (!bh)	/* A hole? */
6522 			memset(data, 0, tocopy);
6523 		else
6524 			memcpy(data, bh->b_data+offset, tocopy);
6525 		brelse(bh);
6526 		offset = 0;
6527 		toread -= tocopy;
6528 		data += tocopy;
6529 		blk++;
6530 	}
6531 	return len;
6532 }
6533 
6534 /* Write to quotafile (we know the transaction is already started and has
6535  * enough credits) */
6536 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6537 				const char *data, size_t len, loff_t off)
6538 {
6539 	struct inode *inode = sb_dqopt(sb)->files[type];
6540 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6541 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6542 	int retries = 0;
6543 	struct buffer_head *bh;
6544 	handle_t *handle = journal_current_handle();
6545 
6546 	if (EXT4_SB(sb)->s_journal && !handle) {
6547 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6548 			" cancelled because transaction is not started",
6549 			(unsigned long long)off, (unsigned long long)len);
6550 		return -EIO;
6551 	}
6552 	/*
6553 	 * Since we account only one data block in transaction credits,
6554 	 * then it is impossible to cross a block boundary.
6555 	 */
6556 	if (sb->s_blocksize - offset < len) {
6557 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6558 			" cancelled because not block aligned",
6559 			(unsigned long long)off, (unsigned long long)len);
6560 		return -EIO;
6561 	}
6562 
6563 	do {
6564 		bh = ext4_bread(handle, inode, blk,
6565 				EXT4_GET_BLOCKS_CREATE |
6566 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6567 	} while (PTR_ERR(bh) == -ENOSPC &&
6568 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6569 	if (IS_ERR(bh))
6570 		return PTR_ERR(bh);
6571 	if (!bh)
6572 		goto out;
6573 	BUFFER_TRACE(bh, "get write access");
6574 	err = ext4_journal_get_write_access(handle, bh);
6575 	if (err) {
6576 		brelse(bh);
6577 		return err;
6578 	}
6579 	lock_buffer(bh);
6580 	memcpy(bh->b_data+offset, data, len);
6581 	flush_dcache_page(bh->b_page);
6582 	unlock_buffer(bh);
6583 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6584 	brelse(bh);
6585 out:
6586 	if (inode->i_size < off + len) {
6587 		i_size_write(inode, off + len);
6588 		EXT4_I(inode)->i_disksize = inode->i_size;
6589 		err2 = ext4_mark_inode_dirty(handle, inode);
6590 		if (unlikely(err2 && !err))
6591 			err = err2;
6592 	}
6593 	return err ? err : len;
6594 }
6595 #endif
6596 
6597 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6598 		       const char *dev_name, void *data)
6599 {
6600 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6601 }
6602 
6603 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6604 static inline void register_as_ext2(void)
6605 {
6606 	int err = register_filesystem(&ext2_fs_type);
6607 	if (err)
6608 		printk(KERN_WARNING
6609 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6610 }
6611 
6612 static inline void unregister_as_ext2(void)
6613 {
6614 	unregister_filesystem(&ext2_fs_type);
6615 }
6616 
6617 static inline int ext2_feature_set_ok(struct super_block *sb)
6618 {
6619 	if (ext4_has_unknown_ext2_incompat_features(sb))
6620 		return 0;
6621 	if (sb_rdonly(sb))
6622 		return 1;
6623 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6624 		return 0;
6625 	return 1;
6626 }
6627 #else
6628 static inline void register_as_ext2(void) { }
6629 static inline void unregister_as_ext2(void) { }
6630 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6631 #endif
6632 
6633 static inline void register_as_ext3(void)
6634 {
6635 	int err = register_filesystem(&ext3_fs_type);
6636 	if (err)
6637 		printk(KERN_WARNING
6638 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6639 }
6640 
6641 static inline void unregister_as_ext3(void)
6642 {
6643 	unregister_filesystem(&ext3_fs_type);
6644 }
6645 
6646 static inline int ext3_feature_set_ok(struct super_block *sb)
6647 {
6648 	if (ext4_has_unknown_ext3_incompat_features(sb))
6649 		return 0;
6650 	if (!ext4_has_feature_journal(sb))
6651 		return 0;
6652 	if (sb_rdonly(sb))
6653 		return 1;
6654 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6655 		return 0;
6656 	return 1;
6657 }
6658 
6659 static struct file_system_type ext4_fs_type = {
6660 	.owner		= THIS_MODULE,
6661 	.name		= "ext4",
6662 	.mount		= ext4_mount,
6663 	.kill_sb	= kill_block_super,
6664 	.fs_flags	= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
6665 };
6666 MODULE_ALIAS_FS("ext4");
6667 
6668 /* Shared across all ext4 file systems */
6669 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6670 
6671 static int __init ext4_init_fs(void)
6672 {
6673 	int i, err;
6674 
6675 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6676 	ext4_li_info = NULL;
6677 
6678 	/* Build-time check for flags consistency */
6679 	ext4_check_flag_values();
6680 
6681 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6682 		init_waitqueue_head(&ext4__ioend_wq[i]);
6683 
6684 	err = ext4_init_es();
6685 	if (err)
6686 		return err;
6687 
6688 	err = ext4_init_pending();
6689 	if (err)
6690 		goto out7;
6691 
6692 	err = ext4_init_post_read_processing();
6693 	if (err)
6694 		goto out6;
6695 
6696 	err = ext4_init_pageio();
6697 	if (err)
6698 		goto out5;
6699 
6700 	err = ext4_init_system_zone();
6701 	if (err)
6702 		goto out4;
6703 
6704 	err = ext4_init_sysfs();
6705 	if (err)
6706 		goto out3;
6707 
6708 	err = ext4_init_mballoc();
6709 	if (err)
6710 		goto out2;
6711 	err = init_inodecache();
6712 	if (err)
6713 		goto out1;
6714 
6715 	err = ext4_fc_init_dentry_cache();
6716 	if (err)
6717 		goto out05;
6718 
6719 	register_as_ext3();
6720 	register_as_ext2();
6721 	err = register_filesystem(&ext4_fs_type);
6722 	if (err)
6723 		goto out;
6724 
6725 	return 0;
6726 out:
6727 	unregister_as_ext2();
6728 	unregister_as_ext3();
6729 out05:
6730 	destroy_inodecache();
6731 out1:
6732 	ext4_exit_mballoc();
6733 out2:
6734 	ext4_exit_sysfs();
6735 out3:
6736 	ext4_exit_system_zone();
6737 out4:
6738 	ext4_exit_pageio();
6739 out5:
6740 	ext4_exit_post_read_processing();
6741 out6:
6742 	ext4_exit_pending();
6743 out7:
6744 	ext4_exit_es();
6745 
6746 	return err;
6747 }
6748 
6749 static void __exit ext4_exit_fs(void)
6750 {
6751 	ext4_destroy_lazyinit_thread();
6752 	unregister_as_ext2();
6753 	unregister_as_ext3();
6754 	unregister_filesystem(&ext4_fs_type);
6755 	destroy_inodecache();
6756 	ext4_exit_mballoc();
6757 	ext4_exit_sysfs();
6758 	ext4_exit_system_zone();
6759 	ext4_exit_pageio();
6760 	ext4_exit_post_read_processing();
6761 	ext4_exit_es();
6762 	ext4_exit_pending();
6763 }
6764 
6765 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6766 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6767 MODULE_LICENSE("GPL");
6768 MODULE_SOFTDEP("pre: crc32c");
6769 module_init(ext4_init_fs)
6770 module_exit(ext4_exit_fs)
6771