xref: /openbmc/linux/fs/ext4/super.c (revision 4ba3fcdde7e36af93610ceb3cc38365b14539865)
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 	/*
671 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
672 	 * could panic during 'reboot -f' as the underlying device got already
673 	 * disabled.
674 	 */
675 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
676 		panic("EXT4-fs (device %s): panic forced after error\n",
677 			sb->s_id);
678 	}
679 
680 	if (sb_rdonly(sb) || continue_fs)
681 		return;
682 
683 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
684 	/*
685 	 * Make sure updated value of ->s_mount_flags will be visible before
686 	 * ->s_flags update
687 	 */
688 	smp_wmb();
689 	sb->s_flags |= SB_RDONLY;
690 }
691 
692 static void flush_stashed_error_work(struct work_struct *work)
693 {
694 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
695 						s_error_work);
696 	journal_t *journal = sbi->s_journal;
697 	handle_t *handle;
698 
699 	/*
700 	 * If the journal is still running, we have to write out superblock
701 	 * through the journal to avoid collisions of other journalled sb
702 	 * updates.
703 	 *
704 	 * We use directly jbd2 functions here to avoid recursing back into
705 	 * ext4 error handling code during handling of previous errors.
706 	 */
707 	if (!sb_rdonly(sbi->s_sb) && journal) {
708 		handle = jbd2_journal_start(journal, 1);
709 		if (IS_ERR(handle))
710 			goto write_directly;
711 		if (jbd2_journal_get_write_access(handle, sbi->s_sbh)) {
712 			jbd2_journal_stop(handle);
713 			goto write_directly;
714 		}
715 		ext4_update_super(sbi->s_sb);
716 		if (jbd2_journal_dirty_metadata(handle, sbi->s_sbh)) {
717 			jbd2_journal_stop(handle);
718 			goto write_directly;
719 		}
720 		jbd2_journal_stop(handle);
721 		return;
722 	}
723 write_directly:
724 	/*
725 	 * Write through journal failed. Write sb directly to get error info
726 	 * out and hope for the best.
727 	 */
728 	ext4_commit_super(sbi->s_sb);
729 }
730 
731 #define ext4_error_ratelimit(sb)					\
732 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
733 			     "EXT4-fs error")
734 
735 void __ext4_error(struct super_block *sb, const char *function,
736 		  unsigned int line, bool force_ro, int error, __u64 block,
737 		  const char *fmt, ...)
738 {
739 	struct va_format vaf;
740 	va_list args;
741 
742 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
743 		return;
744 
745 	trace_ext4_error(sb, function, line);
746 	if (ext4_error_ratelimit(sb)) {
747 		va_start(args, fmt);
748 		vaf.fmt = fmt;
749 		vaf.va = &args;
750 		printk(KERN_CRIT
751 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
752 		       sb->s_id, function, line, current->comm, &vaf);
753 		va_end(args);
754 	}
755 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
756 }
757 
758 void __ext4_error_inode(struct inode *inode, const char *function,
759 			unsigned int line, ext4_fsblk_t block, int error,
760 			const char *fmt, ...)
761 {
762 	va_list args;
763 	struct va_format vaf;
764 
765 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
766 		return;
767 
768 	trace_ext4_error(inode->i_sb, function, line);
769 	if (ext4_error_ratelimit(inode->i_sb)) {
770 		va_start(args, fmt);
771 		vaf.fmt = fmt;
772 		vaf.va = &args;
773 		if (block)
774 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
775 			       "inode #%lu: block %llu: comm %s: %pV\n",
776 			       inode->i_sb->s_id, function, line, inode->i_ino,
777 			       block, current->comm, &vaf);
778 		else
779 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
780 			       "inode #%lu: comm %s: %pV\n",
781 			       inode->i_sb->s_id, function, line, inode->i_ino,
782 			       current->comm, &vaf);
783 		va_end(args);
784 	}
785 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
786 			  function, line);
787 }
788 
789 void __ext4_error_file(struct file *file, const char *function,
790 		       unsigned int line, ext4_fsblk_t block,
791 		       const char *fmt, ...)
792 {
793 	va_list args;
794 	struct va_format vaf;
795 	struct inode *inode = file_inode(file);
796 	char pathname[80], *path;
797 
798 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
799 		return;
800 
801 	trace_ext4_error(inode->i_sb, function, line);
802 	if (ext4_error_ratelimit(inode->i_sb)) {
803 		path = file_path(file, pathname, sizeof(pathname));
804 		if (IS_ERR(path))
805 			path = "(unknown)";
806 		va_start(args, fmt);
807 		vaf.fmt = fmt;
808 		vaf.va = &args;
809 		if (block)
810 			printk(KERN_CRIT
811 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
812 			       "block %llu: comm %s: path %s: %pV\n",
813 			       inode->i_sb->s_id, function, line, inode->i_ino,
814 			       block, current->comm, path, &vaf);
815 		else
816 			printk(KERN_CRIT
817 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
818 			       "comm %s: path %s: %pV\n",
819 			       inode->i_sb->s_id, function, line, inode->i_ino,
820 			       current->comm, path, &vaf);
821 		va_end(args);
822 	}
823 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
824 			  function, line);
825 }
826 
827 const char *ext4_decode_error(struct super_block *sb, int errno,
828 			      char nbuf[16])
829 {
830 	char *errstr = NULL;
831 
832 	switch (errno) {
833 	case -EFSCORRUPTED:
834 		errstr = "Corrupt filesystem";
835 		break;
836 	case -EFSBADCRC:
837 		errstr = "Filesystem failed CRC";
838 		break;
839 	case -EIO:
840 		errstr = "IO failure";
841 		break;
842 	case -ENOMEM:
843 		errstr = "Out of memory";
844 		break;
845 	case -EROFS:
846 		if (!sb || (EXT4_SB(sb)->s_journal &&
847 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
848 			errstr = "Journal has aborted";
849 		else
850 			errstr = "Readonly filesystem";
851 		break;
852 	default:
853 		/* If the caller passed in an extra buffer for unknown
854 		 * errors, textualise them now.  Else we just return
855 		 * NULL. */
856 		if (nbuf) {
857 			/* Check for truncated error codes... */
858 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
859 				errstr = nbuf;
860 		}
861 		break;
862 	}
863 
864 	return errstr;
865 }
866 
867 /* __ext4_std_error decodes expected errors from journaling functions
868  * automatically and invokes the appropriate error response.  */
869 
870 void __ext4_std_error(struct super_block *sb, const char *function,
871 		      unsigned int line, int errno)
872 {
873 	char nbuf[16];
874 	const char *errstr;
875 
876 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
877 		return;
878 
879 	/* Special case: if the error is EROFS, and we're not already
880 	 * inside a transaction, then there's really no point in logging
881 	 * an error. */
882 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
883 		return;
884 
885 	if (ext4_error_ratelimit(sb)) {
886 		errstr = ext4_decode_error(sb, errno, nbuf);
887 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
888 		       sb->s_id, function, line, errstr);
889 	}
890 
891 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
892 }
893 
894 void __ext4_msg(struct super_block *sb,
895 		const char *prefix, const char *fmt, ...)
896 {
897 	struct va_format vaf;
898 	va_list args;
899 
900 	atomic_inc(&EXT4_SB(sb)->s_msg_count);
901 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
902 		return;
903 
904 	va_start(args, fmt);
905 	vaf.fmt = fmt;
906 	vaf.va = &args;
907 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
908 	va_end(args);
909 }
910 
911 static int ext4_warning_ratelimit(struct super_block *sb)
912 {
913 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
914 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
915 			    "EXT4-fs warning");
916 }
917 
918 void __ext4_warning(struct super_block *sb, const char *function,
919 		    unsigned int line, const char *fmt, ...)
920 {
921 	struct va_format vaf;
922 	va_list args;
923 
924 	if (!ext4_warning_ratelimit(sb))
925 		return;
926 
927 	va_start(args, fmt);
928 	vaf.fmt = fmt;
929 	vaf.va = &args;
930 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
931 	       sb->s_id, function, line, &vaf);
932 	va_end(args);
933 }
934 
935 void __ext4_warning_inode(const struct inode *inode, const char *function,
936 			  unsigned int line, const char *fmt, ...)
937 {
938 	struct va_format vaf;
939 	va_list args;
940 
941 	if (!ext4_warning_ratelimit(inode->i_sb))
942 		return;
943 
944 	va_start(args, fmt);
945 	vaf.fmt = fmt;
946 	vaf.va = &args;
947 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
948 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
949 	       function, line, inode->i_ino, current->comm, &vaf);
950 	va_end(args);
951 }
952 
953 void __ext4_grp_locked_error(const char *function, unsigned int line,
954 			     struct super_block *sb, ext4_group_t grp,
955 			     unsigned long ino, ext4_fsblk_t block,
956 			     const char *fmt, ...)
957 __releases(bitlock)
958 __acquires(bitlock)
959 {
960 	struct va_format vaf;
961 	va_list args;
962 
963 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
964 		return;
965 
966 	trace_ext4_error(sb, function, line);
967 	if (ext4_error_ratelimit(sb)) {
968 		va_start(args, fmt);
969 		vaf.fmt = fmt;
970 		vaf.va = &args;
971 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
972 		       sb->s_id, function, line, grp);
973 		if (ino)
974 			printk(KERN_CONT "inode %lu: ", ino);
975 		if (block)
976 			printk(KERN_CONT "block %llu:",
977 			       (unsigned long long) block);
978 		printk(KERN_CONT "%pV\n", &vaf);
979 		va_end(args);
980 	}
981 
982 	if (test_opt(sb, ERRORS_CONT)) {
983 		if (test_opt(sb, WARN_ON_ERROR))
984 			WARN_ON_ONCE(1);
985 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
986 		if (!bdev_read_only(sb->s_bdev)) {
987 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
988 					line);
989 			schedule_work(&EXT4_SB(sb)->s_error_work);
990 		}
991 		return;
992 	}
993 	ext4_unlock_group(sb, grp);
994 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
995 	/*
996 	 * We only get here in the ERRORS_RO case; relocking the group
997 	 * may be dangerous, but nothing bad will happen since the
998 	 * filesystem will have already been marked read/only and the
999 	 * journal has been aborted.  We return 1 as a hint to callers
1000 	 * who might what to use the return value from
1001 	 * ext4_grp_locked_error() to distinguish between the
1002 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1003 	 * aggressively from the ext4 function in question, with a
1004 	 * more appropriate error code.
1005 	 */
1006 	ext4_lock_group(sb, grp);
1007 	return;
1008 }
1009 
1010 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1011 				     ext4_group_t group,
1012 				     unsigned int flags)
1013 {
1014 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1015 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1016 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1017 	int ret;
1018 
1019 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1020 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1021 					    &grp->bb_state);
1022 		if (!ret)
1023 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1024 					   grp->bb_free);
1025 	}
1026 
1027 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1028 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1029 					    &grp->bb_state);
1030 		if (!ret && gdp) {
1031 			int count;
1032 
1033 			count = ext4_free_inodes_count(sb, gdp);
1034 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1035 					   count);
1036 		}
1037 	}
1038 }
1039 
1040 void ext4_update_dynamic_rev(struct super_block *sb)
1041 {
1042 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1043 
1044 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1045 		return;
1046 
1047 	ext4_warning(sb,
1048 		     "updating to rev %d because of new feature flag, "
1049 		     "running e2fsck is recommended",
1050 		     EXT4_DYNAMIC_REV);
1051 
1052 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1053 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1054 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1055 	/* leave es->s_feature_*compat flags alone */
1056 	/* es->s_uuid will be set by e2fsck if empty */
1057 
1058 	/*
1059 	 * The rest of the superblock fields should be zero, and if not it
1060 	 * means they are likely already in use, so leave them alone.  We
1061 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1062 	 */
1063 }
1064 
1065 /*
1066  * Open the external journal device
1067  */
1068 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1069 {
1070 	struct block_device *bdev;
1071 
1072 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1073 	if (IS_ERR(bdev))
1074 		goto fail;
1075 	return bdev;
1076 
1077 fail:
1078 	ext4_msg(sb, KERN_ERR,
1079 		 "failed to open journal device unknown-block(%u,%u) %ld",
1080 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1081 	return NULL;
1082 }
1083 
1084 /*
1085  * Release the journal device
1086  */
1087 static void ext4_blkdev_put(struct block_device *bdev)
1088 {
1089 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1090 }
1091 
1092 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1093 {
1094 	struct block_device *bdev;
1095 	bdev = sbi->s_journal_bdev;
1096 	if (bdev) {
1097 		ext4_blkdev_put(bdev);
1098 		sbi->s_journal_bdev = NULL;
1099 	}
1100 }
1101 
1102 static inline struct inode *orphan_list_entry(struct list_head *l)
1103 {
1104 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1105 }
1106 
1107 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1108 {
1109 	struct list_head *l;
1110 
1111 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1112 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1113 
1114 	printk(KERN_ERR "sb_info orphan list:\n");
1115 	list_for_each(l, &sbi->s_orphan) {
1116 		struct inode *inode = orphan_list_entry(l);
1117 		printk(KERN_ERR "  "
1118 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1119 		       inode->i_sb->s_id, inode->i_ino, inode,
1120 		       inode->i_mode, inode->i_nlink,
1121 		       NEXT_ORPHAN(inode));
1122 	}
1123 }
1124 
1125 #ifdef CONFIG_QUOTA
1126 static int ext4_quota_off(struct super_block *sb, int type);
1127 
1128 static inline void ext4_quota_off_umount(struct super_block *sb)
1129 {
1130 	int type;
1131 
1132 	/* Use our quota_off function to clear inode flags etc. */
1133 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1134 		ext4_quota_off(sb, type);
1135 }
1136 
1137 /*
1138  * This is a helper function which is used in the mount/remount
1139  * codepaths (which holds s_umount) to fetch the quota file name.
1140  */
1141 static inline char *get_qf_name(struct super_block *sb,
1142 				struct ext4_sb_info *sbi,
1143 				int type)
1144 {
1145 	return rcu_dereference_protected(sbi->s_qf_names[type],
1146 					 lockdep_is_held(&sb->s_umount));
1147 }
1148 #else
1149 static inline void ext4_quota_off_umount(struct super_block *sb)
1150 {
1151 }
1152 #endif
1153 
1154 static void ext4_put_super(struct super_block *sb)
1155 {
1156 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1157 	struct ext4_super_block *es = sbi->s_es;
1158 	struct buffer_head **group_desc;
1159 	struct flex_groups **flex_groups;
1160 	int aborted = 0;
1161 	int i, err;
1162 
1163 	ext4_unregister_li_request(sb);
1164 	ext4_quota_off_umount(sb);
1165 
1166 	flush_work(&sbi->s_error_work);
1167 	destroy_workqueue(sbi->rsv_conversion_wq);
1168 
1169 	/*
1170 	 * Unregister sysfs before destroying jbd2 journal.
1171 	 * Since we could still access attr_journal_task attribute via sysfs
1172 	 * path which could have sbi->s_journal->j_task as NULL
1173 	 */
1174 	ext4_unregister_sysfs(sb);
1175 
1176 	if (sbi->s_journal) {
1177 		jbd2_journal_unregister_shrinker(sbi->s_journal);
1178 		aborted = is_journal_aborted(sbi->s_journal);
1179 		err = jbd2_journal_destroy(sbi->s_journal);
1180 		sbi->s_journal = NULL;
1181 		if ((err < 0) && !aborted) {
1182 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1183 		}
1184 	}
1185 
1186 	ext4_es_unregister_shrinker(sbi);
1187 	del_timer_sync(&sbi->s_err_report);
1188 	ext4_release_system_zone(sb);
1189 	ext4_mb_release(sb);
1190 	ext4_ext_release(sb);
1191 
1192 	if (!sb_rdonly(sb) && !aborted) {
1193 		ext4_clear_feature_journal_needs_recovery(sb);
1194 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1195 	}
1196 	if (!sb_rdonly(sb))
1197 		ext4_commit_super(sb);
1198 
1199 	rcu_read_lock();
1200 	group_desc = rcu_dereference(sbi->s_group_desc);
1201 	for (i = 0; i < sbi->s_gdb_count; i++)
1202 		brelse(group_desc[i]);
1203 	kvfree(group_desc);
1204 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1205 	if (flex_groups) {
1206 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1207 			kvfree(flex_groups[i]);
1208 		kvfree(flex_groups);
1209 	}
1210 	rcu_read_unlock();
1211 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1212 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1213 	percpu_counter_destroy(&sbi->s_dirs_counter);
1214 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1215 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1216 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1217 #ifdef CONFIG_QUOTA
1218 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1219 		kfree(get_qf_name(sb, sbi, i));
1220 #endif
1221 
1222 	/* Debugging code just in case the in-memory inode orphan list
1223 	 * isn't empty.  The on-disk one can be non-empty if we've
1224 	 * detected an error and taken the fs readonly, but the
1225 	 * in-memory list had better be clean by this point. */
1226 	if (!list_empty(&sbi->s_orphan))
1227 		dump_orphan_list(sb, sbi);
1228 	ASSERT(list_empty(&sbi->s_orphan));
1229 
1230 	sync_blockdev(sb->s_bdev);
1231 	invalidate_bdev(sb->s_bdev);
1232 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1233 		/*
1234 		 * Invalidate the journal device's buffers.  We don't want them
1235 		 * floating about in memory - the physical journal device may
1236 		 * hotswapped, and it breaks the `ro-after' testing code.
1237 		 */
1238 		sync_blockdev(sbi->s_journal_bdev);
1239 		invalidate_bdev(sbi->s_journal_bdev);
1240 		ext4_blkdev_remove(sbi);
1241 	}
1242 
1243 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1244 	sbi->s_ea_inode_cache = NULL;
1245 
1246 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1247 	sbi->s_ea_block_cache = NULL;
1248 
1249 	ext4_stop_mmpd(sbi);
1250 
1251 	brelse(sbi->s_sbh);
1252 	sb->s_fs_info = NULL;
1253 	/*
1254 	 * Now that we are completely done shutting down the
1255 	 * superblock, we need to actually destroy the kobject.
1256 	 */
1257 	kobject_put(&sbi->s_kobj);
1258 	wait_for_completion(&sbi->s_kobj_unregister);
1259 	if (sbi->s_chksum_driver)
1260 		crypto_free_shash(sbi->s_chksum_driver);
1261 	kfree(sbi->s_blockgroup_lock);
1262 	fs_put_dax(sbi->s_daxdev);
1263 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1264 #ifdef CONFIG_UNICODE
1265 	utf8_unload(sb->s_encoding);
1266 #endif
1267 	kfree(sbi);
1268 }
1269 
1270 static struct kmem_cache *ext4_inode_cachep;
1271 
1272 /*
1273  * Called inside transaction, so use GFP_NOFS
1274  */
1275 static struct inode *ext4_alloc_inode(struct super_block *sb)
1276 {
1277 	struct ext4_inode_info *ei;
1278 
1279 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1280 	if (!ei)
1281 		return NULL;
1282 
1283 	inode_set_iversion(&ei->vfs_inode, 1);
1284 	spin_lock_init(&ei->i_raw_lock);
1285 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1286 	atomic_set(&ei->i_prealloc_active, 0);
1287 	spin_lock_init(&ei->i_prealloc_lock);
1288 	ext4_es_init_tree(&ei->i_es_tree);
1289 	rwlock_init(&ei->i_es_lock);
1290 	INIT_LIST_HEAD(&ei->i_es_list);
1291 	ei->i_es_all_nr = 0;
1292 	ei->i_es_shk_nr = 0;
1293 	ei->i_es_shrink_lblk = 0;
1294 	ei->i_reserved_data_blocks = 0;
1295 	spin_lock_init(&(ei->i_block_reservation_lock));
1296 	ext4_init_pending_tree(&ei->i_pending_tree);
1297 #ifdef CONFIG_QUOTA
1298 	ei->i_reserved_quota = 0;
1299 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1300 #endif
1301 	ei->jinode = NULL;
1302 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1303 	spin_lock_init(&ei->i_completed_io_lock);
1304 	ei->i_sync_tid = 0;
1305 	ei->i_datasync_tid = 0;
1306 	atomic_set(&ei->i_unwritten, 0);
1307 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1308 	ext4_fc_init_inode(&ei->vfs_inode);
1309 	mutex_init(&ei->i_fc_lock);
1310 	return &ei->vfs_inode;
1311 }
1312 
1313 static int ext4_drop_inode(struct inode *inode)
1314 {
1315 	int drop = generic_drop_inode(inode);
1316 
1317 	if (!drop)
1318 		drop = fscrypt_drop_inode(inode);
1319 
1320 	trace_ext4_drop_inode(inode, drop);
1321 	return drop;
1322 }
1323 
1324 static void ext4_free_in_core_inode(struct inode *inode)
1325 {
1326 	fscrypt_free_inode(inode);
1327 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1328 		pr_warn("%s: inode %ld still in fc list",
1329 			__func__, inode->i_ino);
1330 	}
1331 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1332 }
1333 
1334 static void ext4_destroy_inode(struct inode *inode)
1335 {
1336 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1337 		ext4_msg(inode->i_sb, KERN_ERR,
1338 			 "Inode %lu (%p): orphan list check failed!",
1339 			 inode->i_ino, EXT4_I(inode));
1340 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1341 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1342 				true);
1343 		dump_stack();
1344 	}
1345 }
1346 
1347 static void init_once(void *foo)
1348 {
1349 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1350 
1351 	INIT_LIST_HEAD(&ei->i_orphan);
1352 	init_rwsem(&ei->xattr_sem);
1353 	init_rwsem(&ei->i_data_sem);
1354 	init_rwsem(&ei->i_mmap_sem);
1355 	inode_init_once(&ei->vfs_inode);
1356 	ext4_fc_init_inode(&ei->vfs_inode);
1357 }
1358 
1359 static int __init init_inodecache(void)
1360 {
1361 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1362 				sizeof(struct ext4_inode_info), 0,
1363 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1364 					SLAB_ACCOUNT),
1365 				offsetof(struct ext4_inode_info, i_data),
1366 				sizeof_field(struct ext4_inode_info, i_data),
1367 				init_once);
1368 	if (ext4_inode_cachep == NULL)
1369 		return -ENOMEM;
1370 	return 0;
1371 }
1372 
1373 static void destroy_inodecache(void)
1374 {
1375 	/*
1376 	 * Make sure all delayed rcu free inodes are flushed before we
1377 	 * destroy cache.
1378 	 */
1379 	rcu_barrier();
1380 	kmem_cache_destroy(ext4_inode_cachep);
1381 }
1382 
1383 void ext4_clear_inode(struct inode *inode)
1384 {
1385 	ext4_fc_del(inode);
1386 	invalidate_inode_buffers(inode);
1387 	clear_inode(inode);
1388 	ext4_discard_preallocations(inode, 0);
1389 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1390 	dquot_drop(inode);
1391 	if (EXT4_I(inode)->jinode) {
1392 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1393 					       EXT4_I(inode)->jinode);
1394 		jbd2_free_inode(EXT4_I(inode)->jinode);
1395 		EXT4_I(inode)->jinode = NULL;
1396 	}
1397 	fscrypt_put_encryption_info(inode);
1398 	fsverity_cleanup_inode(inode);
1399 }
1400 
1401 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1402 					u64 ino, u32 generation)
1403 {
1404 	struct inode *inode;
1405 
1406 	/*
1407 	 * Currently we don't know the generation for parent directory, so
1408 	 * a generation of 0 means "accept any"
1409 	 */
1410 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1411 	if (IS_ERR(inode))
1412 		return ERR_CAST(inode);
1413 	if (generation && inode->i_generation != generation) {
1414 		iput(inode);
1415 		return ERR_PTR(-ESTALE);
1416 	}
1417 
1418 	return inode;
1419 }
1420 
1421 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1422 					int fh_len, int fh_type)
1423 {
1424 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1425 				    ext4_nfs_get_inode);
1426 }
1427 
1428 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1429 					int fh_len, int fh_type)
1430 {
1431 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1432 				    ext4_nfs_get_inode);
1433 }
1434 
1435 static int ext4_nfs_commit_metadata(struct inode *inode)
1436 {
1437 	struct writeback_control wbc = {
1438 		.sync_mode = WB_SYNC_ALL
1439 	};
1440 
1441 	trace_ext4_nfs_commit_metadata(inode);
1442 	return ext4_write_inode(inode, &wbc);
1443 }
1444 
1445 /*
1446  * Try to release metadata pages (indirect blocks, directories) which are
1447  * mapped via the block device.  Since these pages could have journal heads
1448  * which would prevent try_to_free_buffers() from freeing them, we must use
1449  * jbd2 layer's try_to_free_buffers() function to release them.
1450  */
1451 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1452 				 gfp_t wait)
1453 {
1454 	journal_t *journal = EXT4_SB(sb)->s_journal;
1455 
1456 	WARN_ON(PageChecked(page));
1457 	if (!page_has_buffers(page))
1458 		return 0;
1459 	if (journal)
1460 		return jbd2_journal_try_to_free_buffers(journal, page);
1461 
1462 	return try_to_free_buffers(page);
1463 }
1464 
1465 #ifdef CONFIG_FS_ENCRYPTION
1466 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1467 {
1468 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1469 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1470 }
1471 
1472 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1473 							void *fs_data)
1474 {
1475 	handle_t *handle = fs_data;
1476 	int res, res2, credits, retries = 0;
1477 
1478 	/*
1479 	 * Encrypting the root directory is not allowed because e2fsck expects
1480 	 * lost+found to exist and be unencrypted, and encrypting the root
1481 	 * directory would imply encrypting the lost+found directory as well as
1482 	 * the filename "lost+found" itself.
1483 	 */
1484 	if (inode->i_ino == EXT4_ROOT_INO)
1485 		return -EPERM;
1486 
1487 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1488 		return -EINVAL;
1489 
1490 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1491 		return -EOPNOTSUPP;
1492 
1493 	res = ext4_convert_inline_data(inode);
1494 	if (res)
1495 		return res;
1496 
1497 	/*
1498 	 * If a journal handle was specified, then the encryption context is
1499 	 * being set on a new inode via inheritance and is part of a larger
1500 	 * transaction to create the inode.  Otherwise the encryption context is
1501 	 * being set on an existing inode in its own transaction.  Only in the
1502 	 * latter case should the "retry on ENOSPC" logic be used.
1503 	 */
1504 
1505 	if (handle) {
1506 		res = ext4_xattr_set_handle(handle, inode,
1507 					    EXT4_XATTR_INDEX_ENCRYPTION,
1508 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1509 					    ctx, len, 0);
1510 		if (!res) {
1511 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1512 			ext4_clear_inode_state(inode,
1513 					EXT4_STATE_MAY_INLINE_DATA);
1514 			/*
1515 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1516 			 * S_DAX may be disabled
1517 			 */
1518 			ext4_set_inode_flags(inode, false);
1519 		}
1520 		return res;
1521 	}
1522 
1523 	res = dquot_initialize(inode);
1524 	if (res)
1525 		return res;
1526 retry:
1527 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1528 				     &credits);
1529 	if (res)
1530 		return res;
1531 
1532 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1533 	if (IS_ERR(handle))
1534 		return PTR_ERR(handle);
1535 
1536 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1537 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1538 				    ctx, len, 0);
1539 	if (!res) {
1540 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1541 		/*
1542 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1543 		 * S_DAX may be disabled
1544 		 */
1545 		ext4_set_inode_flags(inode, false);
1546 		res = ext4_mark_inode_dirty(handle, inode);
1547 		if (res)
1548 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1549 	}
1550 	res2 = ext4_journal_stop(handle);
1551 
1552 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1553 		goto retry;
1554 	if (!res)
1555 		res = res2;
1556 	return res;
1557 }
1558 
1559 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1560 {
1561 	return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1562 }
1563 
1564 static bool ext4_has_stable_inodes(struct super_block *sb)
1565 {
1566 	return ext4_has_feature_stable_inodes(sb);
1567 }
1568 
1569 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1570 				       int *ino_bits_ret, int *lblk_bits_ret)
1571 {
1572 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1573 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1574 }
1575 
1576 static const struct fscrypt_operations ext4_cryptops = {
1577 	.key_prefix		= "ext4:",
1578 	.get_context		= ext4_get_context,
1579 	.set_context		= ext4_set_context,
1580 	.get_dummy_policy	= ext4_get_dummy_policy,
1581 	.empty_dir		= ext4_empty_dir,
1582 	.max_namelen		= EXT4_NAME_LEN,
1583 	.has_stable_inodes	= ext4_has_stable_inodes,
1584 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1585 };
1586 #endif
1587 
1588 #ifdef CONFIG_QUOTA
1589 static const char * const quotatypes[] = INITQFNAMES;
1590 #define QTYPE2NAME(t) (quotatypes[t])
1591 
1592 static int ext4_write_dquot(struct dquot *dquot);
1593 static int ext4_acquire_dquot(struct dquot *dquot);
1594 static int ext4_release_dquot(struct dquot *dquot);
1595 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1596 static int ext4_write_info(struct super_block *sb, int type);
1597 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1598 			 const struct path *path);
1599 static int ext4_quota_on_mount(struct super_block *sb, int type);
1600 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1601 			       size_t len, loff_t off);
1602 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1603 				const char *data, size_t len, loff_t off);
1604 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1605 			     unsigned int flags);
1606 static int ext4_enable_quotas(struct super_block *sb);
1607 
1608 static struct dquot **ext4_get_dquots(struct inode *inode)
1609 {
1610 	return EXT4_I(inode)->i_dquot;
1611 }
1612 
1613 static const struct dquot_operations ext4_quota_operations = {
1614 	.get_reserved_space	= ext4_get_reserved_space,
1615 	.write_dquot		= ext4_write_dquot,
1616 	.acquire_dquot		= ext4_acquire_dquot,
1617 	.release_dquot		= ext4_release_dquot,
1618 	.mark_dirty		= ext4_mark_dquot_dirty,
1619 	.write_info		= ext4_write_info,
1620 	.alloc_dquot		= dquot_alloc,
1621 	.destroy_dquot		= dquot_destroy,
1622 	.get_projid		= ext4_get_projid,
1623 	.get_inode_usage	= ext4_get_inode_usage,
1624 	.get_next_id		= dquot_get_next_id,
1625 };
1626 
1627 static const struct quotactl_ops ext4_qctl_operations = {
1628 	.quota_on	= ext4_quota_on,
1629 	.quota_off	= ext4_quota_off,
1630 	.quota_sync	= dquot_quota_sync,
1631 	.get_state	= dquot_get_state,
1632 	.set_info	= dquot_set_dqinfo,
1633 	.get_dqblk	= dquot_get_dqblk,
1634 	.set_dqblk	= dquot_set_dqblk,
1635 	.get_nextdqblk	= dquot_get_next_dqblk,
1636 };
1637 #endif
1638 
1639 static const struct super_operations ext4_sops = {
1640 	.alloc_inode	= ext4_alloc_inode,
1641 	.free_inode	= ext4_free_in_core_inode,
1642 	.destroy_inode	= ext4_destroy_inode,
1643 	.write_inode	= ext4_write_inode,
1644 	.dirty_inode	= ext4_dirty_inode,
1645 	.drop_inode	= ext4_drop_inode,
1646 	.evict_inode	= ext4_evict_inode,
1647 	.put_super	= ext4_put_super,
1648 	.sync_fs	= ext4_sync_fs,
1649 	.freeze_fs	= ext4_freeze,
1650 	.unfreeze_fs	= ext4_unfreeze,
1651 	.statfs		= ext4_statfs,
1652 	.remount_fs	= ext4_remount,
1653 	.show_options	= ext4_show_options,
1654 #ifdef CONFIG_QUOTA
1655 	.quota_read	= ext4_quota_read,
1656 	.quota_write	= ext4_quota_write,
1657 	.get_dquots	= ext4_get_dquots,
1658 #endif
1659 	.bdev_try_to_free_page = bdev_try_to_free_page,
1660 };
1661 
1662 static const struct export_operations ext4_export_ops = {
1663 	.fh_to_dentry = ext4_fh_to_dentry,
1664 	.fh_to_parent = ext4_fh_to_parent,
1665 	.get_parent = ext4_get_parent,
1666 	.commit_metadata = ext4_nfs_commit_metadata,
1667 };
1668 
1669 enum {
1670 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1671 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1672 	Opt_nouid32, Opt_debug, Opt_removed,
1673 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1674 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1675 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1676 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1677 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1678 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1679 	Opt_inlinecrypt,
1680 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1681 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1682 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1683 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1684 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1685 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1686 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1687 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1688 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1689 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1690 	Opt_dioread_nolock, Opt_dioread_lock,
1691 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1692 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1693 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1694 #ifdef CONFIG_EXT4_DEBUG
1695 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1696 #endif
1697 };
1698 
1699 static const match_table_t tokens = {
1700 	{Opt_bsd_df, "bsddf"},
1701 	{Opt_minix_df, "minixdf"},
1702 	{Opt_grpid, "grpid"},
1703 	{Opt_grpid, "bsdgroups"},
1704 	{Opt_nogrpid, "nogrpid"},
1705 	{Opt_nogrpid, "sysvgroups"},
1706 	{Opt_resgid, "resgid=%u"},
1707 	{Opt_resuid, "resuid=%u"},
1708 	{Opt_sb, "sb=%u"},
1709 	{Opt_err_cont, "errors=continue"},
1710 	{Opt_err_panic, "errors=panic"},
1711 	{Opt_err_ro, "errors=remount-ro"},
1712 	{Opt_nouid32, "nouid32"},
1713 	{Opt_debug, "debug"},
1714 	{Opt_removed, "oldalloc"},
1715 	{Opt_removed, "orlov"},
1716 	{Opt_user_xattr, "user_xattr"},
1717 	{Opt_nouser_xattr, "nouser_xattr"},
1718 	{Opt_acl, "acl"},
1719 	{Opt_noacl, "noacl"},
1720 	{Opt_noload, "norecovery"},
1721 	{Opt_noload, "noload"},
1722 	{Opt_removed, "nobh"},
1723 	{Opt_removed, "bh"},
1724 	{Opt_commit, "commit=%u"},
1725 	{Opt_min_batch_time, "min_batch_time=%u"},
1726 	{Opt_max_batch_time, "max_batch_time=%u"},
1727 	{Opt_journal_dev, "journal_dev=%u"},
1728 	{Opt_journal_path, "journal_path=%s"},
1729 	{Opt_journal_checksum, "journal_checksum"},
1730 	{Opt_nojournal_checksum, "nojournal_checksum"},
1731 	{Opt_journal_async_commit, "journal_async_commit"},
1732 	{Opt_abort, "abort"},
1733 	{Opt_data_journal, "data=journal"},
1734 	{Opt_data_ordered, "data=ordered"},
1735 	{Opt_data_writeback, "data=writeback"},
1736 	{Opt_data_err_abort, "data_err=abort"},
1737 	{Opt_data_err_ignore, "data_err=ignore"},
1738 	{Opt_offusrjquota, "usrjquota="},
1739 	{Opt_usrjquota, "usrjquota=%s"},
1740 	{Opt_offgrpjquota, "grpjquota="},
1741 	{Opt_grpjquota, "grpjquota=%s"},
1742 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1743 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1744 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1745 	{Opt_grpquota, "grpquota"},
1746 	{Opt_noquota, "noquota"},
1747 	{Opt_quota, "quota"},
1748 	{Opt_usrquota, "usrquota"},
1749 	{Opt_prjquota, "prjquota"},
1750 	{Opt_barrier, "barrier=%u"},
1751 	{Opt_barrier, "barrier"},
1752 	{Opt_nobarrier, "nobarrier"},
1753 	{Opt_i_version, "i_version"},
1754 	{Opt_dax, "dax"},
1755 	{Opt_dax_always, "dax=always"},
1756 	{Opt_dax_inode, "dax=inode"},
1757 	{Opt_dax_never, "dax=never"},
1758 	{Opt_stripe, "stripe=%u"},
1759 	{Opt_delalloc, "delalloc"},
1760 	{Opt_warn_on_error, "warn_on_error"},
1761 	{Opt_nowarn_on_error, "nowarn_on_error"},
1762 	{Opt_lazytime, "lazytime"},
1763 	{Opt_nolazytime, "nolazytime"},
1764 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1765 	{Opt_nodelalloc, "nodelalloc"},
1766 	{Opt_removed, "mblk_io_submit"},
1767 	{Opt_removed, "nomblk_io_submit"},
1768 	{Opt_block_validity, "block_validity"},
1769 	{Opt_noblock_validity, "noblock_validity"},
1770 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1771 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1772 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1773 	{Opt_auto_da_alloc, "auto_da_alloc"},
1774 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1775 	{Opt_dioread_nolock, "dioread_nolock"},
1776 	{Opt_dioread_lock, "nodioread_nolock"},
1777 	{Opt_dioread_lock, "dioread_lock"},
1778 	{Opt_discard, "discard"},
1779 	{Opt_nodiscard, "nodiscard"},
1780 	{Opt_init_itable, "init_itable=%u"},
1781 	{Opt_init_itable, "init_itable"},
1782 	{Opt_noinit_itable, "noinit_itable"},
1783 #ifdef CONFIG_EXT4_DEBUG
1784 	{Opt_fc_debug_force, "fc_debug_force"},
1785 	{Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
1786 #endif
1787 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1788 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1789 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1790 	{Opt_inlinecrypt, "inlinecrypt"},
1791 	{Opt_nombcache, "nombcache"},
1792 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1793 	{Opt_removed, "prefetch_block_bitmaps"},
1794 	{Opt_no_prefetch_block_bitmaps, "no_prefetch_block_bitmaps"},
1795 	{Opt_mb_optimize_scan, "mb_optimize_scan=%d"},
1796 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1797 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1798 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1799 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1800 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1801 	{Opt_err, NULL},
1802 };
1803 
1804 static ext4_fsblk_t get_sb_block(void **data)
1805 {
1806 	ext4_fsblk_t	sb_block;
1807 	char		*options = (char *) *data;
1808 
1809 	if (!options || strncmp(options, "sb=", 3) != 0)
1810 		return 1;	/* Default location */
1811 
1812 	options += 3;
1813 	/* TODO: use simple_strtoll with >32bit ext4 */
1814 	sb_block = simple_strtoul(options, &options, 0);
1815 	if (*options && *options != ',') {
1816 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1817 		       (char *) *data);
1818 		return 1;
1819 	}
1820 	if (*options == ',')
1821 		options++;
1822 	*data = (void *) options;
1823 
1824 	return sb_block;
1825 }
1826 
1827 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1828 #define DEFAULT_MB_OPTIMIZE_SCAN	(-1)
1829 
1830 static const char deprecated_msg[] =
1831 	"Mount option \"%s\" will be removed by %s\n"
1832 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1833 
1834 #ifdef CONFIG_QUOTA
1835 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1836 {
1837 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1838 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1839 	int ret = -1;
1840 
1841 	if (sb_any_quota_loaded(sb) && !old_qname) {
1842 		ext4_msg(sb, KERN_ERR,
1843 			"Cannot change journaled "
1844 			"quota options when quota turned on");
1845 		return -1;
1846 	}
1847 	if (ext4_has_feature_quota(sb)) {
1848 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1849 			 "ignored when QUOTA feature is enabled");
1850 		return 1;
1851 	}
1852 	qname = match_strdup(args);
1853 	if (!qname) {
1854 		ext4_msg(sb, KERN_ERR,
1855 			"Not enough memory for storing quotafile name");
1856 		return -1;
1857 	}
1858 	if (old_qname) {
1859 		if (strcmp(old_qname, qname) == 0)
1860 			ret = 1;
1861 		else
1862 			ext4_msg(sb, KERN_ERR,
1863 				 "%s quota file already specified",
1864 				 QTYPE2NAME(qtype));
1865 		goto errout;
1866 	}
1867 	if (strchr(qname, '/')) {
1868 		ext4_msg(sb, KERN_ERR,
1869 			"quotafile must be on filesystem root");
1870 		goto errout;
1871 	}
1872 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1873 	set_opt(sb, QUOTA);
1874 	return 1;
1875 errout:
1876 	kfree(qname);
1877 	return ret;
1878 }
1879 
1880 static int clear_qf_name(struct super_block *sb, int qtype)
1881 {
1882 
1883 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1884 	char *old_qname = get_qf_name(sb, sbi, qtype);
1885 
1886 	if (sb_any_quota_loaded(sb) && old_qname) {
1887 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1888 			" when quota turned on");
1889 		return -1;
1890 	}
1891 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1892 	synchronize_rcu();
1893 	kfree(old_qname);
1894 	return 1;
1895 }
1896 #endif
1897 
1898 #define MOPT_SET	0x0001
1899 #define MOPT_CLEAR	0x0002
1900 #define MOPT_NOSUPPORT	0x0004
1901 #define MOPT_EXPLICIT	0x0008
1902 #define MOPT_CLEAR_ERR	0x0010
1903 #define MOPT_GTE0	0x0020
1904 #ifdef CONFIG_QUOTA
1905 #define MOPT_Q		0
1906 #define MOPT_QFMT	0x0040
1907 #else
1908 #define MOPT_Q		MOPT_NOSUPPORT
1909 #define MOPT_QFMT	MOPT_NOSUPPORT
1910 #endif
1911 #define MOPT_DATAJ	0x0080
1912 #define MOPT_NO_EXT2	0x0100
1913 #define MOPT_NO_EXT3	0x0200
1914 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1915 #define MOPT_STRING	0x0400
1916 #define MOPT_SKIP	0x0800
1917 #define	MOPT_2		0x1000
1918 
1919 static const struct mount_opts {
1920 	int	token;
1921 	int	mount_opt;
1922 	int	flags;
1923 } ext4_mount_opts[] = {
1924 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1925 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1926 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1927 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1928 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1929 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1930 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1931 	 MOPT_EXT4_ONLY | MOPT_SET},
1932 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1933 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1934 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1935 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1936 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1937 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1938 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1939 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1940 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1941 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1942 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1943 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1944 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1945 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1946 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1947 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1948 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1949 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1950 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1951 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1952 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1953 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1954 	 MOPT_NO_EXT2},
1955 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1956 	 MOPT_NO_EXT2},
1957 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1958 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1959 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1960 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1961 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1962 	{Opt_commit, 0, MOPT_GTE0},
1963 	{Opt_max_batch_time, 0, MOPT_GTE0},
1964 	{Opt_min_batch_time, 0, MOPT_GTE0},
1965 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1966 	{Opt_init_itable, 0, MOPT_GTE0},
1967 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1968 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1969 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1970 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1971 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1972 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1973 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1974 	{Opt_stripe, 0, MOPT_GTE0},
1975 	{Opt_resuid, 0, MOPT_GTE0},
1976 	{Opt_resgid, 0, MOPT_GTE0},
1977 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1978 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1979 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1980 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1981 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1982 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1983 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1984 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1985 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1986 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1987 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1988 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1989 #else
1990 	{Opt_acl, 0, MOPT_NOSUPPORT},
1991 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1992 #endif
1993 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1994 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1995 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1996 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1997 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1998 							MOPT_SET | MOPT_Q},
1999 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
2000 							MOPT_SET | MOPT_Q},
2001 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
2002 							MOPT_SET | MOPT_Q},
2003 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2004 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
2005 							MOPT_CLEAR | MOPT_Q},
2006 	{Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
2007 	{Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
2008 	{Opt_offusrjquota, 0, MOPT_Q},
2009 	{Opt_offgrpjquota, 0, MOPT_Q},
2010 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
2011 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
2012 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
2013 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
2014 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
2015 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
2016 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
2017 	 MOPT_SET},
2018 	{Opt_mb_optimize_scan, EXT4_MOUNT2_MB_OPTIMIZE_SCAN, MOPT_GTE0},
2019 #ifdef CONFIG_EXT4_DEBUG
2020 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2021 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
2022 	{Opt_fc_debug_max_replay, 0, MOPT_GTE0},
2023 #endif
2024 	{Opt_err, 0, 0}
2025 };
2026 
2027 #ifdef CONFIG_UNICODE
2028 static const struct ext4_sb_encodings {
2029 	__u16 magic;
2030 	char *name;
2031 	char *version;
2032 } ext4_sb_encoding_map[] = {
2033 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
2034 };
2035 
2036 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
2037 				 const struct ext4_sb_encodings **encoding,
2038 				 __u16 *flags)
2039 {
2040 	__u16 magic = le16_to_cpu(es->s_encoding);
2041 	int i;
2042 
2043 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
2044 		if (magic == ext4_sb_encoding_map[i].magic)
2045 			break;
2046 
2047 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
2048 		return -EINVAL;
2049 
2050 	*encoding = &ext4_sb_encoding_map[i];
2051 	*flags = le16_to_cpu(es->s_encoding_flags);
2052 
2053 	return 0;
2054 }
2055 #endif
2056 
2057 static int ext4_set_test_dummy_encryption(struct super_block *sb,
2058 					  const char *opt,
2059 					  const substring_t *arg,
2060 					  bool is_remount)
2061 {
2062 #ifdef CONFIG_FS_ENCRYPTION
2063 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2064 	int err;
2065 
2066 	/*
2067 	 * This mount option is just for testing, and it's not worthwhile to
2068 	 * implement the extra complexity (e.g. RCU protection) that would be
2069 	 * needed to allow it to be set or changed during remount.  We do allow
2070 	 * it to be specified during remount, but only if there is no change.
2071 	 */
2072 	if (is_remount && !sbi->s_dummy_enc_policy.policy) {
2073 		ext4_msg(sb, KERN_WARNING,
2074 			 "Can't set test_dummy_encryption on remount");
2075 		return -1;
2076 	}
2077 	err = fscrypt_set_test_dummy_encryption(sb, arg->from,
2078 						&sbi->s_dummy_enc_policy);
2079 	if (err) {
2080 		if (err == -EEXIST)
2081 			ext4_msg(sb, KERN_WARNING,
2082 				 "Can't change test_dummy_encryption on remount");
2083 		else if (err == -EINVAL)
2084 			ext4_msg(sb, KERN_WARNING,
2085 				 "Value of option \"%s\" is unrecognized", opt);
2086 		else
2087 			ext4_msg(sb, KERN_WARNING,
2088 				 "Error processing option \"%s\" [%d]",
2089 				 opt, err);
2090 		return -1;
2091 	}
2092 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2093 #else
2094 	ext4_msg(sb, KERN_WARNING,
2095 		 "Test dummy encryption mount option ignored");
2096 #endif
2097 	return 1;
2098 }
2099 
2100 struct ext4_parsed_options {
2101 	unsigned long journal_devnum;
2102 	unsigned int journal_ioprio;
2103 	int mb_optimize_scan;
2104 };
2105 
2106 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
2107 			    substring_t *args, struct ext4_parsed_options *parsed_opts,
2108 			    int is_remount)
2109 {
2110 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2111 	const struct mount_opts *m;
2112 	kuid_t uid;
2113 	kgid_t gid;
2114 	int arg = 0;
2115 
2116 #ifdef CONFIG_QUOTA
2117 	if (token == Opt_usrjquota)
2118 		return set_qf_name(sb, USRQUOTA, &args[0]);
2119 	else if (token == Opt_grpjquota)
2120 		return set_qf_name(sb, GRPQUOTA, &args[0]);
2121 	else if (token == Opt_offusrjquota)
2122 		return clear_qf_name(sb, USRQUOTA);
2123 	else if (token == Opt_offgrpjquota)
2124 		return clear_qf_name(sb, GRPQUOTA);
2125 #endif
2126 	switch (token) {
2127 	case Opt_noacl:
2128 	case Opt_nouser_xattr:
2129 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
2130 		break;
2131 	case Opt_sb:
2132 		return 1;	/* handled by get_sb_block() */
2133 	case Opt_removed:
2134 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
2135 		return 1;
2136 	case Opt_abort:
2137 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
2138 		return 1;
2139 	case Opt_i_version:
2140 		sb->s_flags |= SB_I_VERSION;
2141 		return 1;
2142 	case Opt_lazytime:
2143 		sb->s_flags |= SB_LAZYTIME;
2144 		return 1;
2145 	case Opt_nolazytime:
2146 		sb->s_flags &= ~SB_LAZYTIME;
2147 		return 1;
2148 	case Opt_inlinecrypt:
2149 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2150 		sb->s_flags |= SB_INLINECRYPT;
2151 #else
2152 		ext4_msg(sb, KERN_ERR, "inline encryption not supported");
2153 #endif
2154 		return 1;
2155 	}
2156 
2157 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2158 		if (token == m->token)
2159 			break;
2160 
2161 	if (m->token == Opt_err) {
2162 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
2163 			 "or missing value", opt);
2164 		return -1;
2165 	}
2166 
2167 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2168 		ext4_msg(sb, KERN_ERR,
2169 			 "Mount option \"%s\" incompatible with ext2", opt);
2170 		return -1;
2171 	}
2172 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2173 		ext4_msg(sb, KERN_ERR,
2174 			 "Mount option \"%s\" incompatible with ext3", opt);
2175 		return -1;
2176 	}
2177 
2178 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
2179 		return -1;
2180 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
2181 		return -1;
2182 	if (m->flags & MOPT_EXPLICIT) {
2183 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2184 			set_opt2(sb, EXPLICIT_DELALLOC);
2185 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2186 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
2187 		} else
2188 			return -1;
2189 	}
2190 	if (m->flags & MOPT_CLEAR_ERR)
2191 		clear_opt(sb, ERRORS_MASK);
2192 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
2193 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
2194 			 "options when quota turned on");
2195 		return -1;
2196 	}
2197 
2198 	if (m->flags & MOPT_NOSUPPORT) {
2199 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
2200 	} else if (token == Opt_commit) {
2201 		if (arg == 0)
2202 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
2203 		else if (arg > INT_MAX / HZ) {
2204 			ext4_msg(sb, KERN_ERR,
2205 				 "Invalid commit interval %d, "
2206 				 "must be smaller than %d",
2207 				 arg, INT_MAX / HZ);
2208 			return -1;
2209 		}
2210 		sbi->s_commit_interval = HZ * arg;
2211 	} else if (token == Opt_debug_want_extra_isize) {
2212 		if ((arg & 1) ||
2213 		    (arg < 4) ||
2214 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2215 			ext4_msg(sb, KERN_ERR,
2216 				 "Invalid want_extra_isize %d", arg);
2217 			return -1;
2218 		}
2219 		sbi->s_want_extra_isize = arg;
2220 	} else if (token == Opt_max_batch_time) {
2221 		sbi->s_max_batch_time = arg;
2222 	} else if (token == Opt_min_batch_time) {
2223 		sbi->s_min_batch_time = arg;
2224 	} else if (token == Opt_inode_readahead_blks) {
2225 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2226 			ext4_msg(sb, KERN_ERR,
2227 				 "EXT4-fs: inode_readahead_blks must be "
2228 				 "0 or a power of 2 smaller than 2^31");
2229 			return -1;
2230 		}
2231 		sbi->s_inode_readahead_blks = arg;
2232 	} else if (token == Opt_init_itable) {
2233 		set_opt(sb, INIT_INODE_TABLE);
2234 		if (!args->from)
2235 			arg = EXT4_DEF_LI_WAIT_MULT;
2236 		sbi->s_li_wait_mult = arg;
2237 	} else if (token == Opt_max_dir_size_kb) {
2238 		sbi->s_max_dir_size_kb = arg;
2239 #ifdef CONFIG_EXT4_DEBUG
2240 	} else if (token == Opt_fc_debug_max_replay) {
2241 		sbi->s_fc_debug_max_replay = arg;
2242 #endif
2243 	} else if (token == Opt_stripe) {
2244 		sbi->s_stripe = arg;
2245 	} else if (token == Opt_resuid) {
2246 		uid = make_kuid(current_user_ns(), arg);
2247 		if (!uid_valid(uid)) {
2248 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2249 			return -1;
2250 		}
2251 		sbi->s_resuid = uid;
2252 	} else if (token == Opt_resgid) {
2253 		gid = make_kgid(current_user_ns(), arg);
2254 		if (!gid_valid(gid)) {
2255 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2256 			return -1;
2257 		}
2258 		sbi->s_resgid = gid;
2259 	} else if (token == Opt_journal_dev) {
2260 		if (is_remount) {
2261 			ext4_msg(sb, KERN_ERR,
2262 				 "Cannot specify journal on remount");
2263 			return -1;
2264 		}
2265 		parsed_opts->journal_devnum = arg;
2266 	} else if (token == Opt_journal_path) {
2267 		char *journal_path;
2268 		struct inode *journal_inode;
2269 		struct path path;
2270 		int error;
2271 
2272 		if (is_remount) {
2273 			ext4_msg(sb, KERN_ERR,
2274 				 "Cannot specify journal on remount");
2275 			return -1;
2276 		}
2277 		journal_path = match_strdup(&args[0]);
2278 		if (!journal_path) {
2279 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2280 				"journal device string");
2281 			return -1;
2282 		}
2283 
2284 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2285 		if (error) {
2286 			ext4_msg(sb, KERN_ERR, "error: could not find "
2287 				"journal device path: error %d", error);
2288 			kfree(journal_path);
2289 			return -1;
2290 		}
2291 
2292 		journal_inode = d_inode(path.dentry);
2293 		if (!S_ISBLK(journal_inode->i_mode)) {
2294 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2295 				"is not a block device", journal_path);
2296 			path_put(&path);
2297 			kfree(journal_path);
2298 			return -1;
2299 		}
2300 
2301 		parsed_opts->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2302 		path_put(&path);
2303 		kfree(journal_path);
2304 	} else if (token == Opt_journal_ioprio) {
2305 		if (arg > 7) {
2306 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2307 				 " (must be 0-7)");
2308 			return -1;
2309 		}
2310 		parsed_opts->journal_ioprio =
2311 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2312 	} else if (token == Opt_test_dummy_encryption) {
2313 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2314 						      is_remount);
2315 	} else if (m->flags & MOPT_DATAJ) {
2316 		if (is_remount) {
2317 			if (!sbi->s_journal)
2318 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2319 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2320 				ext4_msg(sb, KERN_ERR,
2321 					 "Cannot change data mode on remount");
2322 				return -1;
2323 			}
2324 		} else {
2325 			clear_opt(sb, DATA_FLAGS);
2326 			sbi->s_mount_opt |= m->mount_opt;
2327 		}
2328 #ifdef CONFIG_QUOTA
2329 	} else if (m->flags & MOPT_QFMT) {
2330 		if (sb_any_quota_loaded(sb) &&
2331 		    sbi->s_jquota_fmt != m->mount_opt) {
2332 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2333 				 "quota options when quota turned on");
2334 			return -1;
2335 		}
2336 		if (ext4_has_feature_quota(sb)) {
2337 			ext4_msg(sb, KERN_INFO,
2338 				 "Quota format mount options ignored "
2339 				 "when QUOTA feature is enabled");
2340 			return 1;
2341 		}
2342 		sbi->s_jquota_fmt = m->mount_opt;
2343 #endif
2344 	} else if (token == Opt_dax || token == Opt_dax_always ||
2345 		   token == Opt_dax_inode || token == Opt_dax_never) {
2346 #ifdef CONFIG_FS_DAX
2347 		switch (token) {
2348 		case Opt_dax:
2349 		case Opt_dax_always:
2350 			if (is_remount &&
2351 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2352 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2353 			fail_dax_change_remount:
2354 				ext4_msg(sb, KERN_ERR, "can't change "
2355 					 "dax mount option while remounting");
2356 				return -1;
2357 			}
2358 			if (is_remount &&
2359 			    (test_opt(sb, DATA_FLAGS) ==
2360 			     EXT4_MOUNT_JOURNAL_DATA)) {
2361 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2362 					     "both data=journal and dax");
2363 				    return -1;
2364 			}
2365 			ext4_msg(sb, KERN_WARNING,
2366 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2367 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2368 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2369 			break;
2370 		case Opt_dax_never:
2371 			if (is_remount &&
2372 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2373 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2374 				goto fail_dax_change_remount;
2375 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2376 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2377 			break;
2378 		case Opt_dax_inode:
2379 			if (is_remount &&
2380 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2381 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2382 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2383 				goto fail_dax_change_remount;
2384 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2385 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2386 			/* Strictly for printing options */
2387 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2388 			break;
2389 		}
2390 #else
2391 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2392 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2393 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2394 		return -1;
2395 #endif
2396 	} else if (token == Opt_data_err_abort) {
2397 		sbi->s_mount_opt |= m->mount_opt;
2398 	} else if (token == Opt_data_err_ignore) {
2399 		sbi->s_mount_opt &= ~m->mount_opt;
2400 	} else if (token == Opt_mb_optimize_scan) {
2401 		if (arg != 0 && arg != 1) {
2402 			ext4_msg(sb, KERN_WARNING,
2403 				 "mb_optimize_scan should be set to 0 or 1.");
2404 			return -1;
2405 		}
2406 		parsed_opts->mb_optimize_scan = arg;
2407 	} else {
2408 		if (!args->from)
2409 			arg = 1;
2410 		if (m->flags & MOPT_CLEAR)
2411 			arg = !arg;
2412 		else if (unlikely(!(m->flags & MOPT_SET))) {
2413 			ext4_msg(sb, KERN_WARNING,
2414 				 "buggy handling of option %s", opt);
2415 			WARN_ON(1);
2416 			return -1;
2417 		}
2418 		if (m->flags & MOPT_2) {
2419 			if (arg != 0)
2420 				sbi->s_mount_opt2 |= m->mount_opt;
2421 			else
2422 				sbi->s_mount_opt2 &= ~m->mount_opt;
2423 		} else {
2424 			if (arg != 0)
2425 				sbi->s_mount_opt |= m->mount_opt;
2426 			else
2427 				sbi->s_mount_opt &= ~m->mount_opt;
2428 		}
2429 	}
2430 	return 1;
2431 }
2432 
2433 static int parse_options(char *options, struct super_block *sb,
2434 			 struct ext4_parsed_options *ret_opts,
2435 			 int is_remount)
2436 {
2437 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2438 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2439 	substring_t args[MAX_OPT_ARGS];
2440 	int token;
2441 
2442 	if (!options)
2443 		return 1;
2444 
2445 	while ((p = strsep(&options, ",")) != NULL) {
2446 		if (!*p)
2447 			continue;
2448 		/*
2449 		 * Initialize args struct so we know whether arg was
2450 		 * found; some options take optional arguments.
2451 		 */
2452 		args[0].to = args[0].from = NULL;
2453 		token = match_token(p, tokens, args);
2454 		if (handle_mount_opt(sb, p, token, args, ret_opts,
2455 				     is_remount) < 0)
2456 			return 0;
2457 	}
2458 #ifdef CONFIG_QUOTA
2459 	/*
2460 	 * We do the test below only for project quotas. 'usrquota' and
2461 	 * 'grpquota' mount options are allowed even without quota feature
2462 	 * to support legacy quotas in quota files.
2463 	 */
2464 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2465 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2466 			 "Cannot enable project quota enforcement.");
2467 		return 0;
2468 	}
2469 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2470 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2471 	if (usr_qf_name || grp_qf_name) {
2472 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2473 			clear_opt(sb, USRQUOTA);
2474 
2475 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2476 			clear_opt(sb, GRPQUOTA);
2477 
2478 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2479 			ext4_msg(sb, KERN_ERR, "old and new quota "
2480 					"format mixing");
2481 			return 0;
2482 		}
2483 
2484 		if (!sbi->s_jquota_fmt) {
2485 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2486 					"not specified");
2487 			return 0;
2488 		}
2489 	}
2490 #endif
2491 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2492 		int blocksize =
2493 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2494 		if (blocksize < PAGE_SIZE)
2495 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2496 				 "experimental mount option 'dioread_nolock' "
2497 				 "for blocksize < PAGE_SIZE");
2498 	}
2499 	return 1;
2500 }
2501 
2502 static inline void ext4_show_quota_options(struct seq_file *seq,
2503 					   struct super_block *sb)
2504 {
2505 #if defined(CONFIG_QUOTA)
2506 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2507 	char *usr_qf_name, *grp_qf_name;
2508 
2509 	if (sbi->s_jquota_fmt) {
2510 		char *fmtname = "";
2511 
2512 		switch (sbi->s_jquota_fmt) {
2513 		case QFMT_VFS_OLD:
2514 			fmtname = "vfsold";
2515 			break;
2516 		case QFMT_VFS_V0:
2517 			fmtname = "vfsv0";
2518 			break;
2519 		case QFMT_VFS_V1:
2520 			fmtname = "vfsv1";
2521 			break;
2522 		}
2523 		seq_printf(seq, ",jqfmt=%s", fmtname);
2524 	}
2525 
2526 	rcu_read_lock();
2527 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2528 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2529 	if (usr_qf_name)
2530 		seq_show_option(seq, "usrjquota", usr_qf_name);
2531 	if (grp_qf_name)
2532 		seq_show_option(seq, "grpjquota", grp_qf_name);
2533 	rcu_read_unlock();
2534 #endif
2535 }
2536 
2537 static const char *token2str(int token)
2538 {
2539 	const struct match_token *t;
2540 
2541 	for (t = tokens; t->token != Opt_err; t++)
2542 		if (t->token == token && !strchr(t->pattern, '='))
2543 			break;
2544 	return t->pattern;
2545 }
2546 
2547 /*
2548  * Show an option if
2549  *  - it's set to a non-default value OR
2550  *  - if the per-sb default is different from the global default
2551  */
2552 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2553 			      int nodefs)
2554 {
2555 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2556 	struct ext4_super_block *es = sbi->s_es;
2557 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2558 	const struct mount_opts *m;
2559 	char sep = nodefs ? '\n' : ',';
2560 
2561 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2562 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2563 
2564 	if (sbi->s_sb_block != 1)
2565 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2566 
2567 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2568 		int want_set = m->flags & MOPT_SET;
2569 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2570 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2571 			continue;
2572 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2573 			continue; /* skip if same as the default */
2574 		if ((want_set &&
2575 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2576 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2577 			continue; /* select Opt_noFoo vs Opt_Foo */
2578 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2579 	}
2580 
2581 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2582 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2583 		SEQ_OPTS_PRINT("resuid=%u",
2584 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2585 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2586 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2587 		SEQ_OPTS_PRINT("resgid=%u",
2588 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2589 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2590 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2591 		SEQ_OPTS_PUTS("errors=remount-ro");
2592 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2593 		SEQ_OPTS_PUTS("errors=continue");
2594 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2595 		SEQ_OPTS_PUTS("errors=panic");
2596 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2597 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2598 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2599 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2600 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2601 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2602 	if (sb->s_flags & SB_I_VERSION)
2603 		SEQ_OPTS_PUTS("i_version");
2604 	if (nodefs || sbi->s_stripe)
2605 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2606 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2607 			(sbi->s_mount_opt ^ def_mount_opt)) {
2608 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2609 			SEQ_OPTS_PUTS("data=journal");
2610 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2611 			SEQ_OPTS_PUTS("data=ordered");
2612 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2613 			SEQ_OPTS_PUTS("data=writeback");
2614 	}
2615 	if (nodefs ||
2616 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2617 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2618 			       sbi->s_inode_readahead_blks);
2619 
2620 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2621 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2622 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2623 	if (nodefs || sbi->s_max_dir_size_kb)
2624 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2625 	if (test_opt(sb, DATA_ERR_ABORT))
2626 		SEQ_OPTS_PUTS("data_err=abort");
2627 
2628 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2629 
2630 	if (sb->s_flags & SB_INLINECRYPT)
2631 		SEQ_OPTS_PUTS("inlinecrypt");
2632 
2633 	if (test_opt(sb, DAX_ALWAYS)) {
2634 		if (IS_EXT2_SB(sb))
2635 			SEQ_OPTS_PUTS("dax");
2636 		else
2637 			SEQ_OPTS_PUTS("dax=always");
2638 	} else if (test_opt2(sb, DAX_NEVER)) {
2639 		SEQ_OPTS_PUTS("dax=never");
2640 	} else if (test_opt2(sb, DAX_INODE)) {
2641 		SEQ_OPTS_PUTS("dax=inode");
2642 	}
2643 	ext4_show_quota_options(seq, sb);
2644 	return 0;
2645 }
2646 
2647 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2648 {
2649 	return _ext4_show_options(seq, root->d_sb, 0);
2650 }
2651 
2652 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2653 {
2654 	struct super_block *sb = seq->private;
2655 	int rc;
2656 
2657 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2658 	rc = _ext4_show_options(seq, sb, 1);
2659 	seq_puts(seq, "\n");
2660 	return rc;
2661 }
2662 
2663 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2664 			    int read_only)
2665 {
2666 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2667 	int err = 0;
2668 
2669 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2670 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2671 			 "forcing read-only mode");
2672 		err = -EROFS;
2673 		goto done;
2674 	}
2675 	if (read_only)
2676 		goto done;
2677 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2678 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2679 			 "running e2fsck is recommended");
2680 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2681 		ext4_msg(sb, KERN_WARNING,
2682 			 "warning: mounting fs with errors, "
2683 			 "running e2fsck is recommended");
2684 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2685 		 le16_to_cpu(es->s_mnt_count) >=
2686 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2687 		ext4_msg(sb, KERN_WARNING,
2688 			 "warning: maximal mount count reached, "
2689 			 "running e2fsck is recommended");
2690 	else if (le32_to_cpu(es->s_checkinterval) &&
2691 		 (ext4_get_tstamp(es, s_lastcheck) +
2692 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2693 		ext4_msg(sb, KERN_WARNING,
2694 			 "warning: checktime reached, "
2695 			 "running e2fsck is recommended");
2696 	if (!sbi->s_journal)
2697 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2698 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2699 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2700 	le16_add_cpu(&es->s_mnt_count, 1);
2701 	ext4_update_tstamp(es, s_mtime);
2702 	if (sbi->s_journal)
2703 		ext4_set_feature_journal_needs_recovery(sb);
2704 
2705 	err = ext4_commit_super(sb);
2706 done:
2707 	if (test_opt(sb, DEBUG))
2708 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2709 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2710 			sb->s_blocksize,
2711 			sbi->s_groups_count,
2712 			EXT4_BLOCKS_PER_GROUP(sb),
2713 			EXT4_INODES_PER_GROUP(sb),
2714 			sbi->s_mount_opt, sbi->s_mount_opt2);
2715 
2716 	cleancache_init_fs(sb);
2717 	return err;
2718 }
2719 
2720 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2721 {
2722 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2723 	struct flex_groups **old_groups, **new_groups;
2724 	int size, i, j;
2725 
2726 	if (!sbi->s_log_groups_per_flex)
2727 		return 0;
2728 
2729 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2730 	if (size <= sbi->s_flex_groups_allocated)
2731 		return 0;
2732 
2733 	new_groups = kvzalloc(roundup_pow_of_two(size *
2734 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2735 	if (!new_groups) {
2736 		ext4_msg(sb, KERN_ERR,
2737 			 "not enough memory for %d flex group pointers", size);
2738 		return -ENOMEM;
2739 	}
2740 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2741 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2742 					 sizeof(struct flex_groups)),
2743 					 GFP_KERNEL);
2744 		if (!new_groups[i]) {
2745 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2746 				kvfree(new_groups[j]);
2747 			kvfree(new_groups);
2748 			ext4_msg(sb, KERN_ERR,
2749 				 "not enough memory for %d flex groups", size);
2750 			return -ENOMEM;
2751 		}
2752 	}
2753 	rcu_read_lock();
2754 	old_groups = rcu_dereference(sbi->s_flex_groups);
2755 	if (old_groups)
2756 		memcpy(new_groups, old_groups,
2757 		       (sbi->s_flex_groups_allocated *
2758 			sizeof(struct flex_groups *)));
2759 	rcu_read_unlock();
2760 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2761 	sbi->s_flex_groups_allocated = size;
2762 	if (old_groups)
2763 		ext4_kvfree_array_rcu(old_groups);
2764 	return 0;
2765 }
2766 
2767 static int ext4_fill_flex_info(struct super_block *sb)
2768 {
2769 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2770 	struct ext4_group_desc *gdp = NULL;
2771 	struct flex_groups *fg;
2772 	ext4_group_t flex_group;
2773 	int i, err;
2774 
2775 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2776 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2777 		sbi->s_log_groups_per_flex = 0;
2778 		return 1;
2779 	}
2780 
2781 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2782 	if (err)
2783 		goto failed;
2784 
2785 	for (i = 0; i < sbi->s_groups_count; i++) {
2786 		gdp = ext4_get_group_desc(sb, i, NULL);
2787 
2788 		flex_group = ext4_flex_group(sbi, i);
2789 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2790 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2791 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2792 			     &fg->free_clusters);
2793 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2794 	}
2795 
2796 	return 1;
2797 failed:
2798 	return 0;
2799 }
2800 
2801 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2802 				   struct ext4_group_desc *gdp)
2803 {
2804 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2805 	__u16 crc = 0;
2806 	__le32 le_group = cpu_to_le32(block_group);
2807 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2808 
2809 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2810 		/* Use new metadata_csum algorithm */
2811 		__u32 csum32;
2812 		__u16 dummy_csum = 0;
2813 
2814 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2815 				     sizeof(le_group));
2816 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2817 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2818 				     sizeof(dummy_csum));
2819 		offset += sizeof(dummy_csum);
2820 		if (offset < sbi->s_desc_size)
2821 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2822 					     sbi->s_desc_size - offset);
2823 
2824 		crc = csum32 & 0xFFFF;
2825 		goto out;
2826 	}
2827 
2828 	/* old crc16 code */
2829 	if (!ext4_has_feature_gdt_csum(sb))
2830 		return 0;
2831 
2832 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2833 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2834 	crc = crc16(crc, (__u8 *)gdp, offset);
2835 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2836 	/* for checksum of struct ext4_group_desc do the rest...*/
2837 	if (ext4_has_feature_64bit(sb) &&
2838 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2839 		crc = crc16(crc, (__u8 *)gdp + offset,
2840 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2841 				offset);
2842 
2843 out:
2844 	return cpu_to_le16(crc);
2845 }
2846 
2847 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2848 				struct ext4_group_desc *gdp)
2849 {
2850 	if (ext4_has_group_desc_csum(sb) &&
2851 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2852 		return 0;
2853 
2854 	return 1;
2855 }
2856 
2857 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2858 			      struct ext4_group_desc *gdp)
2859 {
2860 	if (!ext4_has_group_desc_csum(sb))
2861 		return;
2862 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2863 }
2864 
2865 /* Called at mount-time, super-block is locked */
2866 static int ext4_check_descriptors(struct super_block *sb,
2867 				  ext4_fsblk_t sb_block,
2868 				  ext4_group_t *first_not_zeroed)
2869 {
2870 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2871 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2872 	ext4_fsblk_t last_block;
2873 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2874 	ext4_fsblk_t block_bitmap;
2875 	ext4_fsblk_t inode_bitmap;
2876 	ext4_fsblk_t inode_table;
2877 	int flexbg_flag = 0;
2878 	ext4_group_t i, grp = sbi->s_groups_count;
2879 
2880 	if (ext4_has_feature_flex_bg(sb))
2881 		flexbg_flag = 1;
2882 
2883 	ext4_debug("Checking group descriptors");
2884 
2885 	for (i = 0; i < sbi->s_groups_count; i++) {
2886 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2887 
2888 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2889 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2890 		else
2891 			last_block = first_block +
2892 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2893 
2894 		if ((grp == sbi->s_groups_count) &&
2895 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2896 			grp = i;
2897 
2898 		block_bitmap = ext4_block_bitmap(sb, gdp);
2899 		if (block_bitmap == sb_block) {
2900 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2901 				 "Block bitmap for group %u overlaps "
2902 				 "superblock", i);
2903 			if (!sb_rdonly(sb))
2904 				return 0;
2905 		}
2906 		if (block_bitmap >= sb_block + 1 &&
2907 		    block_bitmap <= last_bg_block) {
2908 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2909 				 "Block bitmap for group %u overlaps "
2910 				 "block group descriptors", i);
2911 			if (!sb_rdonly(sb))
2912 				return 0;
2913 		}
2914 		if (block_bitmap < first_block || block_bitmap > last_block) {
2915 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2916 			       "Block bitmap for group %u not in group "
2917 			       "(block %llu)!", i, block_bitmap);
2918 			return 0;
2919 		}
2920 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2921 		if (inode_bitmap == sb_block) {
2922 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2923 				 "Inode bitmap for group %u overlaps "
2924 				 "superblock", i);
2925 			if (!sb_rdonly(sb))
2926 				return 0;
2927 		}
2928 		if (inode_bitmap >= sb_block + 1 &&
2929 		    inode_bitmap <= last_bg_block) {
2930 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2931 				 "Inode bitmap for group %u overlaps "
2932 				 "block group descriptors", i);
2933 			if (!sb_rdonly(sb))
2934 				return 0;
2935 		}
2936 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2937 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2938 			       "Inode bitmap for group %u not in group "
2939 			       "(block %llu)!", i, inode_bitmap);
2940 			return 0;
2941 		}
2942 		inode_table = ext4_inode_table(sb, gdp);
2943 		if (inode_table == sb_block) {
2944 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2945 				 "Inode table for group %u overlaps "
2946 				 "superblock", i);
2947 			if (!sb_rdonly(sb))
2948 				return 0;
2949 		}
2950 		if (inode_table >= sb_block + 1 &&
2951 		    inode_table <= last_bg_block) {
2952 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2953 				 "Inode table for group %u overlaps "
2954 				 "block group descriptors", i);
2955 			if (!sb_rdonly(sb))
2956 				return 0;
2957 		}
2958 		if (inode_table < first_block ||
2959 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2960 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2961 			       "Inode table for group %u not in group "
2962 			       "(block %llu)!", i, inode_table);
2963 			return 0;
2964 		}
2965 		ext4_lock_group(sb, i);
2966 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2967 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2968 				 "Checksum for group %u failed (%u!=%u)",
2969 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2970 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2971 			if (!sb_rdonly(sb)) {
2972 				ext4_unlock_group(sb, i);
2973 				return 0;
2974 			}
2975 		}
2976 		ext4_unlock_group(sb, i);
2977 		if (!flexbg_flag)
2978 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2979 	}
2980 	if (NULL != first_not_zeroed)
2981 		*first_not_zeroed = grp;
2982 	return 1;
2983 }
2984 
2985 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2986  * the superblock) which were deleted from all directories, but held open by
2987  * a process at the time of a crash.  We walk the list and try to delete these
2988  * inodes at recovery time (only with a read-write filesystem).
2989  *
2990  * In order to keep the orphan inode chain consistent during traversal (in
2991  * case of crash during recovery), we link each inode into the superblock
2992  * orphan list_head and handle it the same way as an inode deletion during
2993  * normal operation (which journals the operations for us).
2994  *
2995  * We only do an iget() and an iput() on each inode, which is very safe if we
2996  * accidentally point at an in-use or already deleted inode.  The worst that
2997  * can happen in this case is that we get a "bit already cleared" message from
2998  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2999  * e2fsck was run on this filesystem, and it must have already done the orphan
3000  * inode cleanup for us, so we can safely abort without any further action.
3001  */
3002 static void ext4_orphan_cleanup(struct super_block *sb,
3003 				struct ext4_super_block *es)
3004 {
3005 	unsigned int s_flags = sb->s_flags;
3006 	int ret, nr_orphans = 0, nr_truncates = 0;
3007 #ifdef CONFIG_QUOTA
3008 	int quota_update = 0;
3009 	int i;
3010 #endif
3011 	if (!es->s_last_orphan) {
3012 		jbd_debug(4, "no orphan inodes to clean up\n");
3013 		return;
3014 	}
3015 
3016 	if (bdev_read_only(sb->s_bdev)) {
3017 		ext4_msg(sb, KERN_ERR, "write access "
3018 			"unavailable, skipping orphan cleanup");
3019 		return;
3020 	}
3021 
3022 	/* Check if feature set would not allow a r/w mount */
3023 	if (!ext4_feature_set_ok(sb, 0)) {
3024 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
3025 			 "unknown ROCOMPAT features");
3026 		return;
3027 	}
3028 
3029 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3030 		/* don't clear list on RO mount w/ errors */
3031 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
3032 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
3033 				  "clearing orphan list.\n");
3034 			es->s_last_orphan = 0;
3035 		}
3036 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3037 		return;
3038 	}
3039 
3040 	if (s_flags & SB_RDONLY) {
3041 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
3042 		sb->s_flags &= ~SB_RDONLY;
3043 	}
3044 #ifdef CONFIG_QUOTA
3045 	/*
3046 	 * Turn on quotas which were not enabled for read-only mounts if
3047 	 * filesystem has quota feature, so that they are updated correctly.
3048 	 */
3049 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
3050 		int ret = ext4_enable_quotas(sb);
3051 
3052 		if (!ret)
3053 			quota_update = 1;
3054 		else
3055 			ext4_msg(sb, KERN_ERR,
3056 				"Cannot turn on quotas: error %d", ret);
3057 	}
3058 
3059 	/* Turn on journaled quotas used for old sytle */
3060 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3061 		if (EXT4_SB(sb)->s_qf_names[i]) {
3062 			int ret = ext4_quota_on_mount(sb, i);
3063 
3064 			if (!ret)
3065 				quota_update = 1;
3066 			else
3067 				ext4_msg(sb, KERN_ERR,
3068 					"Cannot turn on journaled "
3069 					"quota: type %d: error %d", i, ret);
3070 		}
3071 	}
3072 #endif
3073 
3074 	while (es->s_last_orphan) {
3075 		struct inode *inode;
3076 
3077 		/*
3078 		 * We may have encountered an error during cleanup; if
3079 		 * so, skip the rest.
3080 		 */
3081 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3082 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3083 			es->s_last_orphan = 0;
3084 			break;
3085 		}
3086 
3087 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
3088 		if (IS_ERR(inode)) {
3089 			es->s_last_orphan = 0;
3090 			break;
3091 		}
3092 
3093 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
3094 		dquot_initialize(inode);
3095 		if (inode->i_nlink) {
3096 			if (test_opt(sb, DEBUG))
3097 				ext4_msg(sb, KERN_DEBUG,
3098 					"%s: truncating inode %lu to %lld bytes",
3099 					__func__, inode->i_ino, inode->i_size);
3100 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
3101 				  inode->i_ino, inode->i_size);
3102 			inode_lock(inode);
3103 			truncate_inode_pages(inode->i_mapping, inode->i_size);
3104 			ret = ext4_truncate(inode);
3105 			if (ret) {
3106 				/*
3107 				 * We need to clean up the in-core orphan list
3108 				 * manually if ext4_truncate() failed to get a
3109 				 * transaction handle.
3110 				 */
3111 				ext4_orphan_del(NULL, inode);
3112 				ext4_std_error(inode->i_sb, ret);
3113 			}
3114 			inode_unlock(inode);
3115 			nr_truncates++;
3116 		} else {
3117 			if (test_opt(sb, DEBUG))
3118 				ext4_msg(sb, KERN_DEBUG,
3119 					"%s: deleting unreferenced inode %lu",
3120 					__func__, inode->i_ino);
3121 			jbd_debug(2, "deleting unreferenced inode %lu\n",
3122 				  inode->i_ino);
3123 			nr_orphans++;
3124 		}
3125 		iput(inode);  /* The delete magic happens here! */
3126 	}
3127 
3128 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
3129 
3130 	if (nr_orphans)
3131 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
3132 		       PLURAL(nr_orphans));
3133 	if (nr_truncates)
3134 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
3135 		       PLURAL(nr_truncates));
3136 #ifdef CONFIG_QUOTA
3137 	/* Turn off quotas if they were enabled for orphan cleanup */
3138 	if (quota_update) {
3139 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3140 			if (sb_dqopt(sb)->files[i])
3141 				dquot_quota_off(sb, i);
3142 		}
3143 	}
3144 #endif
3145 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
3146 }
3147 
3148 /*
3149  * Maximal extent format file size.
3150  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3151  * extent format containers, within a sector_t, and within i_blocks
3152  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3153  * so that won't be a limiting factor.
3154  *
3155  * However there is other limiting factor. We do store extents in the form
3156  * of starting block and length, hence the resulting length of the extent
3157  * covering maximum file size must fit into on-disk format containers as
3158  * well. Given that length is always by 1 unit bigger than max unit (because
3159  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3160  *
3161  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3162  */
3163 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3164 {
3165 	loff_t res;
3166 	loff_t upper_limit = MAX_LFS_FILESIZE;
3167 
3168 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3169 
3170 	if (!has_huge_files) {
3171 		upper_limit = (1LL << 32) - 1;
3172 
3173 		/* total blocks in file system block size */
3174 		upper_limit >>= (blkbits - 9);
3175 		upper_limit <<= blkbits;
3176 	}
3177 
3178 	/*
3179 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3180 	 * by one fs block, so ee_len can cover the extent of maximum file
3181 	 * size
3182 	 */
3183 	res = (1LL << 32) - 1;
3184 	res <<= blkbits;
3185 
3186 	/* Sanity check against vm- & vfs- imposed limits */
3187 	if (res > upper_limit)
3188 		res = upper_limit;
3189 
3190 	return res;
3191 }
3192 
3193 /*
3194  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3195  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3196  * We need to be 1 filesystem block less than the 2^48 sector limit.
3197  */
3198 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3199 {
3200 	loff_t res = EXT4_NDIR_BLOCKS;
3201 	int meta_blocks;
3202 	loff_t upper_limit;
3203 	/* This is calculated to be the largest file size for a dense, block
3204 	 * mapped file such that the file's total number of 512-byte sectors,
3205 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3206 	 *
3207 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3208 	 * number of 512-byte sectors of the file.
3209 	 */
3210 
3211 	if (!has_huge_files) {
3212 		/*
3213 		 * !has_huge_files or implies that the inode i_block field
3214 		 * represents total file blocks in 2^32 512-byte sectors ==
3215 		 * size of vfs inode i_blocks * 8
3216 		 */
3217 		upper_limit = (1LL << 32) - 1;
3218 
3219 		/* total blocks in file system block size */
3220 		upper_limit >>= (bits - 9);
3221 
3222 	} else {
3223 		/*
3224 		 * We use 48 bit ext4_inode i_blocks
3225 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3226 		 * represent total number of blocks in
3227 		 * file system block size
3228 		 */
3229 		upper_limit = (1LL << 48) - 1;
3230 
3231 	}
3232 
3233 	/* indirect blocks */
3234 	meta_blocks = 1;
3235 	/* double indirect blocks */
3236 	meta_blocks += 1 + (1LL << (bits-2));
3237 	/* tripple indirect blocks */
3238 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3239 
3240 	upper_limit -= meta_blocks;
3241 	upper_limit <<= bits;
3242 
3243 	res += 1LL << (bits-2);
3244 	res += 1LL << (2*(bits-2));
3245 	res += 1LL << (3*(bits-2));
3246 	res <<= bits;
3247 	if (res > upper_limit)
3248 		res = upper_limit;
3249 
3250 	if (res > MAX_LFS_FILESIZE)
3251 		res = MAX_LFS_FILESIZE;
3252 
3253 	return res;
3254 }
3255 
3256 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3257 				   ext4_fsblk_t logical_sb_block, int nr)
3258 {
3259 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3260 	ext4_group_t bg, first_meta_bg;
3261 	int has_super = 0;
3262 
3263 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3264 
3265 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3266 		return logical_sb_block + nr + 1;
3267 	bg = sbi->s_desc_per_block * nr;
3268 	if (ext4_bg_has_super(sb, bg))
3269 		has_super = 1;
3270 
3271 	/*
3272 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3273 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3274 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3275 	 * compensate.
3276 	 */
3277 	if (sb->s_blocksize == 1024 && nr == 0 &&
3278 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3279 		has_super++;
3280 
3281 	return (has_super + ext4_group_first_block_no(sb, bg));
3282 }
3283 
3284 /**
3285  * ext4_get_stripe_size: Get the stripe size.
3286  * @sbi: In memory super block info
3287  *
3288  * If we have specified it via mount option, then
3289  * use the mount option value. If the value specified at mount time is
3290  * greater than the blocks per group use the super block value.
3291  * If the super block value is greater than blocks per group return 0.
3292  * Allocator needs it be less than blocks per group.
3293  *
3294  */
3295 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3296 {
3297 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3298 	unsigned long stripe_width =
3299 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3300 	int ret;
3301 
3302 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3303 		ret = sbi->s_stripe;
3304 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3305 		ret = stripe_width;
3306 	else if (stride && stride <= sbi->s_blocks_per_group)
3307 		ret = stride;
3308 	else
3309 		ret = 0;
3310 
3311 	/*
3312 	 * If the stripe width is 1, this makes no sense and
3313 	 * we set it to 0 to turn off stripe handling code.
3314 	 */
3315 	if (ret <= 1)
3316 		ret = 0;
3317 
3318 	return ret;
3319 }
3320 
3321 /*
3322  * Check whether this filesystem can be mounted based on
3323  * the features present and the RDONLY/RDWR mount requested.
3324  * Returns 1 if this filesystem can be mounted as requested,
3325  * 0 if it cannot be.
3326  */
3327 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3328 {
3329 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3330 		ext4_msg(sb, KERN_ERR,
3331 			"Couldn't mount because of "
3332 			"unsupported optional features (%x)",
3333 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3334 			~EXT4_FEATURE_INCOMPAT_SUPP));
3335 		return 0;
3336 	}
3337 
3338 #ifndef CONFIG_UNICODE
3339 	if (ext4_has_feature_casefold(sb)) {
3340 		ext4_msg(sb, KERN_ERR,
3341 			 "Filesystem with casefold feature cannot be "
3342 			 "mounted without CONFIG_UNICODE");
3343 		return 0;
3344 	}
3345 #endif
3346 
3347 	if (readonly)
3348 		return 1;
3349 
3350 	if (ext4_has_feature_readonly(sb)) {
3351 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3352 		sb->s_flags |= SB_RDONLY;
3353 		return 1;
3354 	}
3355 
3356 	/* Check that feature set is OK for a read-write mount */
3357 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3358 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3359 			 "unsupported optional features (%x)",
3360 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3361 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3362 		return 0;
3363 	}
3364 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3365 		ext4_msg(sb, KERN_ERR,
3366 			 "Can't support bigalloc feature without "
3367 			 "extents feature\n");
3368 		return 0;
3369 	}
3370 
3371 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3372 	if (!readonly && (ext4_has_feature_quota(sb) ||
3373 			  ext4_has_feature_project(sb))) {
3374 		ext4_msg(sb, KERN_ERR,
3375 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3376 		return 0;
3377 	}
3378 #endif  /* CONFIG_QUOTA */
3379 	return 1;
3380 }
3381 
3382 /*
3383  * This function is called once a day if we have errors logged
3384  * on the file system
3385  */
3386 static void print_daily_error_info(struct timer_list *t)
3387 {
3388 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3389 	struct super_block *sb = sbi->s_sb;
3390 	struct ext4_super_block *es = sbi->s_es;
3391 
3392 	if (es->s_error_count)
3393 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3394 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3395 			 le32_to_cpu(es->s_error_count));
3396 	if (es->s_first_error_time) {
3397 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3398 		       sb->s_id,
3399 		       ext4_get_tstamp(es, s_first_error_time),
3400 		       (int) sizeof(es->s_first_error_func),
3401 		       es->s_first_error_func,
3402 		       le32_to_cpu(es->s_first_error_line));
3403 		if (es->s_first_error_ino)
3404 			printk(KERN_CONT ": inode %u",
3405 			       le32_to_cpu(es->s_first_error_ino));
3406 		if (es->s_first_error_block)
3407 			printk(KERN_CONT ": block %llu", (unsigned long long)
3408 			       le64_to_cpu(es->s_first_error_block));
3409 		printk(KERN_CONT "\n");
3410 	}
3411 	if (es->s_last_error_time) {
3412 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3413 		       sb->s_id,
3414 		       ext4_get_tstamp(es, s_last_error_time),
3415 		       (int) sizeof(es->s_last_error_func),
3416 		       es->s_last_error_func,
3417 		       le32_to_cpu(es->s_last_error_line));
3418 		if (es->s_last_error_ino)
3419 			printk(KERN_CONT ": inode %u",
3420 			       le32_to_cpu(es->s_last_error_ino));
3421 		if (es->s_last_error_block)
3422 			printk(KERN_CONT ": block %llu", (unsigned long long)
3423 			       le64_to_cpu(es->s_last_error_block));
3424 		printk(KERN_CONT "\n");
3425 	}
3426 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3427 }
3428 
3429 /* Find next suitable group and run ext4_init_inode_table */
3430 static int ext4_run_li_request(struct ext4_li_request *elr)
3431 {
3432 	struct ext4_group_desc *gdp = NULL;
3433 	struct super_block *sb = elr->lr_super;
3434 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3435 	ext4_group_t group = elr->lr_next_group;
3436 	unsigned long timeout = 0;
3437 	unsigned int prefetch_ios = 0;
3438 	int ret = 0;
3439 
3440 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3441 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3442 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3443 		if (prefetch_ios)
3444 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3445 					      prefetch_ios);
3446 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3447 					    prefetch_ios);
3448 		if (group >= elr->lr_next_group) {
3449 			ret = 1;
3450 			if (elr->lr_first_not_zeroed != ngroups &&
3451 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3452 				elr->lr_next_group = elr->lr_first_not_zeroed;
3453 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3454 				ret = 0;
3455 			}
3456 		}
3457 		return ret;
3458 	}
3459 
3460 	for (; group < ngroups; group++) {
3461 		gdp = ext4_get_group_desc(sb, group, NULL);
3462 		if (!gdp) {
3463 			ret = 1;
3464 			break;
3465 		}
3466 
3467 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3468 			break;
3469 	}
3470 
3471 	if (group >= ngroups)
3472 		ret = 1;
3473 
3474 	if (!ret) {
3475 		timeout = jiffies;
3476 		ret = ext4_init_inode_table(sb, group,
3477 					    elr->lr_timeout ? 0 : 1);
3478 		trace_ext4_lazy_itable_init(sb, group);
3479 		if (elr->lr_timeout == 0) {
3480 			timeout = (jiffies - timeout) *
3481 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3482 			elr->lr_timeout = timeout;
3483 		}
3484 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3485 		elr->lr_next_group = group + 1;
3486 	}
3487 	return ret;
3488 }
3489 
3490 /*
3491  * Remove lr_request from the list_request and free the
3492  * request structure. Should be called with li_list_mtx held
3493  */
3494 static void ext4_remove_li_request(struct ext4_li_request *elr)
3495 {
3496 	if (!elr)
3497 		return;
3498 
3499 	list_del(&elr->lr_request);
3500 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3501 	kfree(elr);
3502 }
3503 
3504 static void ext4_unregister_li_request(struct super_block *sb)
3505 {
3506 	mutex_lock(&ext4_li_mtx);
3507 	if (!ext4_li_info) {
3508 		mutex_unlock(&ext4_li_mtx);
3509 		return;
3510 	}
3511 
3512 	mutex_lock(&ext4_li_info->li_list_mtx);
3513 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3514 	mutex_unlock(&ext4_li_info->li_list_mtx);
3515 	mutex_unlock(&ext4_li_mtx);
3516 }
3517 
3518 static struct task_struct *ext4_lazyinit_task;
3519 
3520 /*
3521  * This is the function where ext4lazyinit thread lives. It walks
3522  * through the request list searching for next scheduled filesystem.
3523  * When such a fs is found, run the lazy initialization request
3524  * (ext4_rn_li_request) and keep track of the time spend in this
3525  * function. Based on that time we compute next schedule time of
3526  * the request. When walking through the list is complete, compute
3527  * next waking time and put itself into sleep.
3528  */
3529 static int ext4_lazyinit_thread(void *arg)
3530 {
3531 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3532 	struct list_head *pos, *n;
3533 	struct ext4_li_request *elr;
3534 	unsigned long next_wakeup, cur;
3535 
3536 	BUG_ON(NULL == eli);
3537 
3538 cont_thread:
3539 	while (true) {
3540 		next_wakeup = MAX_JIFFY_OFFSET;
3541 
3542 		mutex_lock(&eli->li_list_mtx);
3543 		if (list_empty(&eli->li_request_list)) {
3544 			mutex_unlock(&eli->li_list_mtx);
3545 			goto exit_thread;
3546 		}
3547 		list_for_each_safe(pos, n, &eli->li_request_list) {
3548 			int err = 0;
3549 			int progress = 0;
3550 			elr = list_entry(pos, struct ext4_li_request,
3551 					 lr_request);
3552 
3553 			if (time_before(jiffies, elr->lr_next_sched)) {
3554 				if (time_before(elr->lr_next_sched, next_wakeup))
3555 					next_wakeup = elr->lr_next_sched;
3556 				continue;
3557 			}
3558 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3559 				if (sb_start_write_trylock(elr->lr_super)) {
3560 					progress = 1;
3561 					/*
3562 					 * We hold sb->s_umount, sb can not
3563 					 * be removed from the list, it is
3564 					 * now safe to drop li_list_mtx
3565 					 */
3566 					mutex_unlock(&eli->li_list_mtx);
3567 					err = ext4_run_li_request(elr);
3568 					sb_end_write(elr->lr_super);
3569 					mutex_lock(&eli->li_list_mtx);
3570 					n = pos->next;
3571 				}
3572 				up_read((&elr->lr_super->s_umount));
3573 			}
3574 			/* error, remove the lazy_init job */
3575 			if (err) {
3576 				ext4_remove_li_request(elr);
3577 				continue;
3578 			}
3579 			if (!progress) {
3580 				elr->lr_next_sched = jiffies +
3581 					(prandom_u32()
3582 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3583 			}
3584 			if (time_before(elr->lr_next_sched, next_wakeup))
3585 				next_wakeup = elr->lr_next_sched;
3586 		}
3587 		mutex_unlock(&eli->li_list_mtx);
3588 
3589 		try_to_freeze();
3590 
3591 		cur = jiffies;
3592 		if ((time_after_eq(cur, next_wakeup)) ||
3593 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3594 			cond_resched();
3595 			continue;
3596 		}
3597 
3598 		schedule_timeout_interruptible(next_wakeup - cur);
3599 
3600 		if (kthread_should_stop()) {
3601 			ext4_clear_request_list();
3602 			goto exit_thread;
3603 		}
3604 	}
3605 
3606 exit_thread:
3607 	/*
3608 	 * It looks like the request list is empty, but we need
3609 	 * to check it under the li_list_mtx lock, to prevent any
3610 	 * additions into it, and of course we should lock ext4_li_mtx
3611 	 * to atomically free the list and ext4_li_info, because at
3612 	 * this point another ext4 filesystem could be registering
3613 	 * new one.
3614 	 */
3615 	mutex_lock(&ext4_li_mtx);
3616 	mutex_lock(&eli->li_list_mtx);
3617 	if (!list_empty(&eli->li_request_list)) {
3618 		mutex_unlock(&eli->li_list_mtx);
3619 		mutex_unlock(&ext4_li_mtx);
3620 		goto cont_thread;
3621 	}
3622 	mutex_unlock(&eli->li_list_mtx);
3623 	kfree(ext4_li_info);
3624 	ext4_li_info = NULL;
3625 	mutex_unlock(&ext4_li_mtx);
3626 
3627 	return 0;
3628 }
3629 
3630 static void ext4_clear_request_list(void)
3631 {
3632 	struct list_head *pos, *n;
3633 	struct ext4_li_request *elr;
3634 
3635 	mutex_lock(&ext4_li_info->li_list_mtx);
3636 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3637 		elr = list_entry(pos, struct ext4_li_request,
3638 				 lr_request);
3639 		ext4_remove_li_request(elr);
3640 	}
3641 	mutex_unlock(&ext4_li_info->li_list_mtx);
3642 }
3643 
3644 static int ext4_run_lazyinit_thread(void)
3645 {
3646 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3647 					 ext4_li_info, "ext4lazyinit");
3648 	if (IS_ERR(ext4_lazyinit_task)) {
3649 		int err = PTR_ERR(ext4_lazyinit_task);
3650 		ext4_clear_request_list();
3651 		kfree(ext4_li_info);
3652 		ext4_li_info = NULL;
3653 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3654 				 "initialization thread\n",
3655 				 err);
3656 		return err;
3657 	}
3658 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3659 	return 0;
3660 }
3661 
3662 /*
3663  * Check whether it make sense to run itable init. thread or not.
3664  * If there is at least one uninitialized inode table, return
3665  * corresponding group number, else the loop goes through all
3666  * groups and return total number of groups.
3667  */
3668 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3669 {
3670 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3671 	struct ext4_group_desc *gdp = NULL;
3672 
3673 	if (!ext4_has_group_desc_csum(sb))
3674 		return ngroups;
3675 
3676 	for (group = 0; group < ngroups; group++) {
3677 		gdp = ext4_get_group_desc(sb, group, NULL);
3678 		if (!gdp)
3679 			continue;
3680 
3681 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3682 			break;
3683 	}
3684 
3685 	return group;
3686 }
3687 
3688 static int ext4_li_info_new(void)
3689 {
3690 	struct ext4_lazy_init *eli = NULL;
3691 
3692 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3693 	if (!eli)
3694 		return -ENOMEM;
3695 
3696 	INIT_LIST_HEAD(&eli->li_request_list);
3697 	mutex_init(&eli->li_list_mtx);
3698 
3699 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3700 
3701 	ext4_li_info = eli;
3702 
3703 	return 0;
3704 }
3705 
3706 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3707 					    ext4_group_t start)
3708 {
3709 	struct ext4_li_request *elr;
3710 
3711 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3712 	if (!elr)
3713 		return NULL;
3714 
3715 	elr->lr_super = sb;
3716 	elr->lr_first_not_zeroed = start;
3717 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3718 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3719 		elr->lr_next_group = start;
3720 	} else {
3721 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3722 	}
3723 
3724 	/*
3725 	 * Randomize first schedule time of the request to
3726 	 * spread the inode table initialization requests
3727 	 * better.
3728 	 */
3729 	elr->lr_next_sched = jiffies + (prandom_u32() %
3730 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3731 	return elr;
3732 }
3733 
3734 int ext4_register_li_request(struct super_block *sb,
3735 			     ext4_group_t first_not_zeroed)
3736 {
3737 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3738 	struct ext4_li_request *elr = NULL;
3739 	ext4_group_t ngroups = sbi->s_groups_count;
3740 	int ret = 0;
3741 
3742 	mutex_lock(&ext4_li_mtx);
3743 	if (sbi->s_li_request != NULL) {
3744 		/*
3745 		 * Reset timeout so it can be computed again, because
3746 		 * s_li_wait_mult might have changed.
3747 		 */
3748 		sbi->s_li_request->lr_timeout = 0;
3749 		goto out;
3750 	}
3751 
3752 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3753 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3754 	     !test_opt(sb, INIT_INODE_TABLE)))
3755 		goto out;
3756 
3757 	elr = ext4_li_request_new(sb, first_not_zeroed);
3758 	if (!elr) {
3759 		ret = -ENOMEM;
3760 		goto out;
3761 	}
3762 
3763 	if (NULL == ext4_li_info) {
3764 		ret = ext4_li_info_new();
3765 		if (ret)
3766 			goto out;
3767 	}
3768 
3769 	mutex_lock(&ext4_li_info->li_list_mtx);
3770 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3771 	mutex_unlock(&ext4_li_info->li_list_mtx);
3772 
3773 	sbi->s_li_request = elr;
3774 	/*
3775 	 * set elr to NULL here since it has been inserted to
3776 	 * the request_list and the removal and free of it is
3777 	 * handled by ext4_clear_request_list from now on.
3778 	 */
3779 	elr = NULL;
3780 
3781 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3782 		ret = ext4_run_lazyinit_thread();
3783 		if (ret)
3784 			goto out;
3785 	}
3786 out:
3787 	mutex_unlock(&ext4_li_mtx);
3788 	if (ret)
3789 		kfree(elr);
3790 	return ret;
3791 }
3792 
3793 /*
3794  * We do not need to lock anything since this is called on
3795  * module unload.
3796  */
3797 static void ext4_destroy_lazyinit_thread(void)
3798 {
3799 	/*
3800 	 * If thread exited earlier
3801 	 * there's nothing to be done.
3802 	 */
3803 	if (!ext4_li_info || !ext4_lazyinit_task)
3804 		return;
3805 
3806 	kthread_stop(ext4_lazyinit_task);
3807 }
3808 
3809 static int set_journal_csum_feature_set(struct super_block *sb)
3810 {
3811 	int ret = 1;
3812 	int compat, incompat;
3813 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3814 
3815 	if (ext4_has_metadata_csum(sb)) {
3816 		/* journal checksum v3 */
3817 		compat = 0;
3818 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3819 	} else {
3820 		/* journal checksum v1 */
3821 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3822 		incompat = 0;
3823 	}
3824 
3825 	jbd2_journal_clear_features(sbi->s_journal,
3826 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3827 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3828 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3829 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3830 		ret = jbd2_journal_set_features(sbi->s_journal,
3831 				compat, 0,
3832 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3833 				incompat);
3834 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3835 		ret = jbd2_journal_set_features(sbi->s_journal,
3836 				compat, 0,
3837 				incompat);
3838 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3839 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3840 	} else {
3841 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3842 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3843 	}
3844 
3845 	return ret;
3846 }
3847 
3848 /*
3849  * Note: calculating the overhead so we can be compatible with
3850  * historical BSD practice is quite difficult in the face of
3851  * clusters/bigalloc.  This is because multiple metadata blocks from
3852  * different block group can end up in the same allocation cluster.
3853  * Calculating the exact overhead in the face of clustered allocation
3854  * requires either O(all block bitmaps) in memory or O(number of block
3855  * groups**2) in time.  We will still calculate the superblock for
3856  * older file systems --- and if we come across with a bigalloc file
3857  * system with zero in s_overhead_clusters the estimate will be close to
3858  * correct especially for very large cluster sizes --- but for newer
3859  * file systems, it's better to calculate this figure once at mkfs
3860  * time, and store it in the superblock.  If the superblock value is
3861  * present (even for non-bigalloc file systems), we will use it.
3862  */
3863 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3864 			  char *buf)
3865 {
3866 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3867 	struct ext4_group_desc	*gdp;
3868 	ext4_fsblk_t		first_block, last_block, b;
3869 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3870 	int			s, j, count = 0;
3871 
3872 	if (!ext4_has_feature_bigalloc(sb))
3873 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3874 			sbi->s_itb_per_group + 2);
3875 
3876 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3877 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3878 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3879 	for (i = 0; i < ngroups; i++) {
3880 		gdp = ext4_get_group_desc(sb, i, NULL);
3881 		b = ext4_block_bitmap(sb, gdp);
3882 		if (b >= first_block && b <= last_block) {
3883 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3884 			count++;
3885 		}
3886 		b = ext4_inode_bitmap(sb, gdp);
3887 		if (b >= first_block && b <= last_block) {
3888 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3889 			count++;
3890 		}
3891 		b = ext4_inode_table(sb, gdp);
3892 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3893 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3894 				int c = EXT4_B2C(sbi, b - first_block);
3895 				ext4_set_bit(c, buf);
3896 				count++;
3897 			}
3898 		if (i != grp)
3899 			continue;
3900 		s = 0;
3901 		if (ext4_bg_has_super(sb, grp)) {
3902 			ext4_set_bit(s++, buf);
3903 			count++;
3904 		}
3905 		j = ext4_bg_num_gdb(sb, grp);
3906 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3907 			ext4_error(sb, "Invalid number of block group "
3908 				   "descriptor blocks: %d", j);
3909 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3910 		}
3911 		count += j;
3912 		for (; j > 0; j--)
3913 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3914 	}
3915 	if (!count)
3916 		return 0;
3917 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3918 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3919 }
3920 
3921 /*
3922  * Compute the overhead and stash it in sbi->s_overhead
3923  */
3924 int ext4_calculate_overhead(struct super_block *sb)
3925 {
3926 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3927 	struct ext4_super_block *es = sbi->s_es;
3928 	struct inode *j_inode;
3929 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3930 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3931 	ext4_fsblk_t overhead = 0;
3932 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3933 
3934 	if (!buf)
3935 		return -ENOMEM;
3936 
3937 	/*
3938 	 * Compute the overhead (FS structures).  This is constant
3939 	 * for a given filesystem unless the number of block groups
3940 	 * changes so we cache the previous value until it does.
3941 	 */
3942 
3943 	/*
3944 	 * All of the blocks before first_data_block are overhead
3945 	 */
3946 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3947 
3948 	/*
3949 	 * Add the overhead found in each block group
3950 	 */
3951 	for (i = 0; i < ngroups; i++) {
3952 		int blks;
3953 
3954 		blks = count_overhead(sb, i, buf);
3955 		overhead += blks;
3956 		if (blks)
3957 			memset(buf, 0, PAGE_SIZE);
3958 		cond_resched();
3959 	}
3960 
3961 	/*
3962 	 * Add the internal journal blocks whether the journal has been
3963 	 * loaded or not
3964 	 */
3965 	if (sbi->s_journal && !sbi->s_journal_bdev)
3966 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
3967 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3968 		/* j_inum for internal journal is non-zero */
3969 		j_inode = ext4_get_journal_inode(sb, j_inum);
3970 		if (j_inode) {
3971 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3972 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3973 			iput(j_inode);
3974 		} else {
3975 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3976 		}
3977 	}
3978 	sbi->s_overhead = overhead;
3979 	smp_wmb();
3980 	free_page((unsigned long) buf);
3981 	return 0;
3982 }
3983 
3984 static void ext4_set_resv_clusters(struct super_block *sb)
3985 {
3986 	ext4_fsblk_t resv_clusters;
3987 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3988 
3989 	/*
3990 	 * There's no need to reserve anything when we aren't using extents.
3991 	 * The space estimates are exact, there are no unwritten extents,
3992 	 * hole punching doesn't need new metadata... This is needed especially
3993 	 * to keep ext2/3 backward compatibility.
3994 	 */
3995 	if (!ext4_has_feature_extents(sb))
3996 		return;
3997 	/*
3998 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3999 	 * This should cover the situations where we can not afford to run
4000 	 * out of space like for example punch hole, or converting
4001 	 * unwritten extents in delalloc path. In most cases such
4002 	 * allocation would require 1, or 2 blocks, higher numbers are
4003 	 * very rare.
4004 	 */
4005 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4006 			 sbi->s_cluster_bits);
4007 
4008 	do_div(resv_clusters, 50);
4009 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4010 
4011 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4012 }
4013 
4014 static const char *ext4_quota_mode(struct super_block *sb)
4015 {
4016 #ifdef CONFIG_QUOTA
4017 	if (!ext4_quota_capable(sb))
4018 		return "none";
4019 
4020 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4021 		return "journalled";
4022 	else
4023 		return "writeback";
4024 #else
4025 	return "disabled";
4026 #endif
4027 }
4028 
4029 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
4030 {
4031 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
4032 	char *orig_data = kstrdup(data, GFP_KERNEL);
4033 	struct buffer_head *bh, **group_desc;
4034 	struct ext4_super_block *es = NULL;
4035 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4036 	struct flex_groups **flex_groups;
4037 	ext4_fsblk_t block;
4038 	ext4_fsblk_t sb_block = get_sb_block(&data);
4039 	ext4_fsblk_t logical_sb_block;
4040 	unsigned long offset = 0;
4041 	unsigned long def_mount_opts;
4042 	struct inode *root;
4043 	const char *descr;
4044 	int ret = -ENOMEM;
4045 	int blocksize, clustersize;
4046 	unsigned int db_count;
4047 	unsigned int i;
4048 	int needs_recovery, has_huge_files;
4049 	__u64 blocks_count;
4050 	int err = 0;
4051 	ext4_group_t first_not_zeroed;
4052 	struct ext4_parsed_options parsed_opts;
4053 
4054 	/* Set defaults for the variables that will be set during parsing */
4055 	parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4056 	parsed_opts.journal_devnum = 0;
4057 	parsed_opts.mb_optimize_scan = DEFAULT_MB_OPTIMIZE_SCAN;
4058 
4059 	if ((data && !orig_data) || !sbi)
4060 		goto out_free_base;
4061 
4062 	sbi->s_daxdev = dax_dev;
4063 	sbi->s_blockgroup_lock =
4064 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4065 	if (!sbi->s_blockgroup_lock)
4066 		goto out_free_base;
4067 
4068 	sb->s_fs_info = sbi;
4069 	sbi->s_sb = sb;
4070 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4071 	sbi->s_sb_block = sb_block;
4072 	sbi->s_sectors_written_start =
4073 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4074 
4075 	/* Cleanup superblock name */
4076 	strreplace(sb->s_id, '/', '!');
4077 
4078 	/* -EINVAL is default */
4079 	ret = -EINVAL;
4080 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4081 	if (!blocksize) {
4082 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4083 		goto out_fail;
4084 	}
4085 
4086 	/*
4087 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4088 	 * block sizes.  We need to calculate the offset from buffer start.
4089 	 */
4090 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4091 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4092 		offset = do_div(logical_sb_block, blocksize);
4093 	} else {
4094 		logical_sb_block = sb_block;
4095 	}
4096 
4097 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4098 	if (IS_ERR(bh)) {
4099 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4100 		ret = PTR_ERR(bh);
4101 		goto out_fail;
4102 	}
4103 	/*
4104 	 * Note: s_es must be initialized as soon as possible because
4105 	 *       some ext4 macro-instructions depend on its value
4106 	 */
4107 	es = (struct ext4_super_block *) (bh->b_data + offset);
4108 	sbi->s_es = es;
4109 	sb->s_magic = le16_to_cpu(es->s_magic);
4110 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4111 		goto cantfind_ext4;
4112 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4113 
4114 	/* Warn if metadata_csum and gdt_csum are both set. */
4115 	if (ext4_has_feature_metadata_csum(sb) &&
4116 	    ext4_has_feature_gdt_csum(sb))
4117 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4118 			     "redundant flags; please run fsck.");
4119 
4120 	/* Check for a known checksum algorithm */
4121 	if (!ext4_verify_csum_type(sb, es)) {
4122 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4123 			 "unknown checksum algorithm.");
4124 		silent = 1;
4125 		goto cantfind_ext4;
4126 	}
4127 
4128 	/* Load the checksum driver */
4129 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4130 	if (IS_ERR(sbi->s_chksum_driver)) {
4131 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4132 		ret = PTR_ERR(sbi->s_chksum_driver);
4133 		sbi->s_chksum_driver = NULL;
4134 		goto failed_mount;
4135 	}
4136 
4137 	/* Check superblock checksum */
4138 	if (!ext4_superblock_csum_verify(sb, es)) {
4139 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4140 			 "invalid superblock checksum.  Run e2fsck?");
4141 		silent = 1;
4142 		ret = -EFSBADCRC;
4143 		goto cantfind_ext4;
4144 	}
4145 
4146 	/* Precompute checksum seed for all metadata */
4147 	if (ext4_has_feature_csum_seed(sb))
4148 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4149 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4150 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4151 					       sizeof(es->s_uuid));
4152 
4153 	/* Set defaults before we parse the mount options */
4154 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4155 	set_opt(sb, INIT_INODE_TABLE);
4156 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4157 		set_opt(sb, DEBUG);
4158 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4159 		set_opt(sb, GRPID);
4160 	if (def_mount_opts & EXT4_DEFM_UID16)
4161 		set_opt(sb, NO_UID32);
4162 	/* xattr user namespace & acls are now defaulted on */
4163 	set_opt(sb, XATTR_USER);
4164 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4165 	set_opt(sb, POSIX_ACL);
4166 #endif
4167 	if (ext4_has_feature_fast_commit(sb))
4168 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4169 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4170 	if (ext4_has_metadata_csum(sb))
4171 		set_opt(sb, JOURNAL_CHECKSUM);
4172 
4173 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4174 		set_opt(sb, JOURNAL_DATA);
4175 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4176 		set_opt(sb, ORDERED_DATA);
4177 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4178 		set_opt(sb, WRITEBACK_DATA);
4179 
4180 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4181 		set_opt(sb, ERRORS_PANIC);
4182 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4183 		set_opt(sb, ERRORS_CONT);
4184 	else
4185 		set_opt(sb, ERRORS_RO);
4186 	/* block_validity enabled by default; disable with noblock_validity */
4187 	set_opt(sb, BLOCK_VALIDITY);
4188 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4189 		set_opt(sb, DISCARD);
4190 
4191 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4192 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4193 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4194 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4195 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4196 
4197 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4198 		set_opt(sb, BARRIER);
4199 
4200 	/*
4201 	 * enable delayed allocation by default
4202 	 * Use -o nodelalloc to turn it off
4203 	 */
4204 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4205 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4206 		set_opt(sb, DELALLOC);
4207 
4208 	/*
4209 	 * set default s_li_wait_mult for lazyinit, for the case there is
4210 	 * no mount option specified.
4211 	 */
4212 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4213 
4214 	if (le32_to_cpu(es->s_log_block_size) >
4215 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4216 		ext4_msg(sb, KERN_ERR,
4217 			 "Invalid log block size: %u",
4218 			 le32_to_cpu(es->s_log_block_size));
4219 		goto failed_mount;
4220 	}
4221 	if (le32_to_cpu(es->s_log_cluster_size) >
4222 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4223 		ext4_msg(sb, KERN_ERR,
4224 			 "Invalid log cluster size: %u",
4225 			 le32_to_cpu(es->s_log_cluster_size));
4226 		goto failed_mount;
4227 	}
4228 
4229 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4230 
4231 	if (blocksize == PAGE_SIZE)
4232 		set_opt(sb, DIOREAD_NOLOCK);
4233 
4234 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4235 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4236 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4237 	} else {
4238 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4239 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4240 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4241 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4242 				 sbi->s_first_ino);
4243 			goto failed_mount;
4244 		}
4245 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4246 		    (!is_power_of_2(sbi->s_inode_size)) ||
4247 		    (sbi->s_inode_size > blocksize)) {
4248 			ext4_msg(sb, KERN_ERR,
4249 			       "unsupported inode size: %d",
4250 			       sbi->s_inode_size);
4251 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4252 			goto failed_mount;
4253 		}
4254 		/*
4255 		 * i_atime_extra is the last extra field available for
4256 		 * [acm]times in struct ext4_inode. Checking for that
4257 		 * field should suffice to ensure we have extra space
4258 		 * for all three.
4259 		 */
4260 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4261 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4262 			sb->s_time_gran = 1;
4263 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4264 		} else {
4265 			sb->s_time_gran = NSEC_PER_SEC;
4266 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4267 		}
4268 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4269 	}
4270 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4271 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4272 			EXT4_GOOD_OLD_INODE_SIZE;
4273 		if (ext4_has_feature_extra_isize(sb)) {
4274 			unsigned v, max = (sbi->s_inode_size -
4275 					   EXT4_GOOD_OLD_INODE_SIZE);
4276 
4277 			v = le16_to_cpu(es->s_want_extra_isize);
4278 			if (v > max) {
4279 				ext4_msg(sb, KERN_ERR,
4280 					 "bad s_want_extra_isize: %d", v);
4281 				goto failed_mount;
4282 			}
4283 			if (sbi->s_want_extra_isize < v)
4284 				sbi->s_want_extra_isize = v;
4285 
4286 			v = le16_to_cpu(es->s_min_extra_isize);
4287 			if (v > max) {
4288 				ext4_msg(sb, KERN_ERR,
4289 					 "bad s_min_extra_isize: %d", v);
4290 				goto failed_mount;
4291 			}
4292 			if (sbi->s_want_extra_isize < v)
4293 				sbi->s_want_extra_isize = v;
4294 		}
4295 	}
4296 
4297 	if (sbi->s_es->s_mount_opts[0]) {
4298 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4299 					      sizeof(sbi->s_es->s_mount_opts),
4300 					      GFP_KERNEL);
4301 		if (!s_mount_opts)
4302 			goto failed_mount;
4303 		if (!parse_options(s_mount_opts, sb, &parsed_opts, 0)) {
4304 			ext4_msg(sb, KERN_WARNING,
4305 				 "failed to parse options in superblock: %s",
4306 				 s_mount_opts);
4307 		}
4308 		kfree(s_mount_opts);
4309 	}
4310 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4311 	if (!parse_options((char *) data, sb, &parsed_opts, 0))
4312 		goto failed_mount;
4313 
4314 #ifdef CONFIG_UNICODE
4315 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4316 		const struct ext4_sb_encodings *encoding_info;
4317 		struct unicode_map *encoding;
4318 		__u16 encoding_flags;
4319 
4320 		if (ext4_sb_read_encoding(es, &encoding_info,
4321 					  &encoding_flags)) {
4322 			ext4_msg(sb, KERN_ERR,
4323 				 "Encoding requested by superblock is unknown");
4324 			goto failed_mount;
4325 		}
4326 
4327 		encoding = utf8_load(encoding_info->version);
4328 		if (IS_ERR(encoding)) {
4329 			ext4_msg(sb, KERN_ERR,
4330 				 "can't mount with superblock charset: %s-%s "
4331 				 "not supported by the kernel. flags: 0x%x.",
4332 				 encoding_info->name, encoding_info->version,
4333 				 encoding_flags);
4334 			goto failed_mount;
4335 		}
4336 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4337 			 "%s-%s with flags 0x%hx", encoding_info->name,
4338 			 encoding_info->version?:"\b", encoding_flags);
4339 
4340 		sb->s_encoding = encoding;
4341 		sb->s_encoding_flags = encoding_flags;
4342 	}
4343 #endif
4344 
4345 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4346 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4347 		/* can't mount with both data=journal and dioread_nolock. */
4348 		clear_opt(sb, DIOREAD_NOLOCK);
4349 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4350 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4351 			ext4_msg(sb, KERN_ERR, "can't mount with "
4352 				 "both data=journal and delalloc");
4353 			goto failed_mount;
4354 		}
4355 		if (test_opt(sb, DAX_ALWAYS)) {
4356 			ext4_msg(sb, KERN_ERR, "can't mount with "
4357 				 "both data=journal and dax");
4358 			goto failed_mount;
4359 		}
4360 		if (ext4_has_feature_encrypt(sb)) {
4361 			ext4_msg(sb, KERN_WARNING,
4362 				 "encrypted files will use data=ordered "
4363 				 "instead of data journaling mode");
4364 		}
4365 		if (test_opt(sb, DELALLOC))
4366 			clear_opt(sb, DELALLOC);
4367 	} else {
4368 		sb->s_iflags |= SB_I_CGROUPWB;
4369 	}
4370 
4371 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4372 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4373 
4374 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4375 	    (ext4_has_compat_features(sb) ||
4376 	     ext4_has_ro_compat_features(sb) ||
4377 	     ext4_has_incompat_features(sb)))
4378 		ext4_msg(sb, KERN_WARNING,
4379 		       "feature flags set on rev 0 fs, "
4380 		       "running e2fsck is recommended");
4381 
4382 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4383 		set_opt2(sb, HURD_COMPAT);
4384 		if (ext4_has_feature_64bit(sb)) {
4385 			ext4_msg(sb, KERN_ERR,
4386 				 "The Hurd can't support 64-bit file systems");
4387 			goto failed_mount;
4388 		}
4389 
4390 		/*
4391 		 * ea_inode feature uses l_i_version field which is not
4392 		 * available in HURD_COMPAT mode.
4393 		 */
4394 		if (ext4_has_feature_ea_inode(sb)) {
4395 			ext4_msg(sb, KERN_ERR,
4396 				 "ea_inode feature is not supported for Hurd");
4397 			goto failed_mount;
4398 		}
4399 	}
4400 
4401 	if (IS_EXT2_SB(sb)) {
4402 		if (ext2_feature_set_ok(sb))
4403 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4404 				 "using the ext4 subsystem");
4405 		else {
4406 			/*
4407 			 * If we're probing be silent, if this looks like
4408 			 * it's actually an ext[34] filesystem.
4409 			 */
4410 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4411 				goto failed_mount;
4412 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4413 				 "to feature incompatibilities");
4414 			goto failed_mount;
4415 		}
4416 	}
4417 
4418 	if (IS_EXT3_SB(sb)) {
4419 		if (ext3_feature_set_ok(sb))
4420 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4421 				 "using the ext4 subsystem");
4422 		else {
4423 			/*
4424 			 * If we're probing be silent, if this looks like
4425 			 * it's actually an ext4 filesystem.
4426 			 */
4427 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4428 				goto failed_mount;
4429 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4430 				 "to feature incompatibilities");
4431 			goto failed_mount;
4432 		}
4433 	}
4434 
4435 	/*
4436 	 * Check feature flags regardless of the revision level, since we
4437 	 * previously didn't change the revision level when setting the flags,
4438 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4439 	 */
4440 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4441 		goto failed_mount;
4442 
4443 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4444 		ext4_msg(sb, KERN_ERR,
4445 			 "Number of reserved GDT blocks insanely large: %d",
4446 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4447 		goto failed_mount;
4448 	}
4449 
4450 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4451 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4452 
4453 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4454 		if (ext4_has_feature_inline_data(sb)) {
4455 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4456 					" that may contain inline data");
4457 			goto failed_mount;
4458 		}
4459 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4460 			ext4_msg(sb, KERN_ERR,
4461 				"DAX unsupported by block device.");
4462 			goto failed_mount;
4463 		}
4464 	}
4465 
4466 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4467 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4468 			 es->s_encryption_level);
4469 		goto failed_mount;
4470 	}
4471 
4472 	if (sb->s_blocksize != blocksize) {
4473 		/*
4474 		 * bh must be released before kill_bdev(), otherwise
4475 		 * it won't be freed and its page also. kill_bdev()
4476 		 * is called by sb_set_blocksize().
4477 		 */
4478 		brelse(bh);
4479 		/* Validate the filesystem blocksize */
4480 		if (!sb_set_blocksize(sb, blocksize)) {
4481 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4482 					blocksize);
4483 			bh = NULL;
4484 			goto failed_mount;
4485 		}
4486 
4487 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4488 		offset = do_div(logical_sb_block, blocksize);
4489 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4490 		if (IS_ERR(bh)) {
4491 			ext4_msg(sb, KERN_ERR,
4492 			       "Can't read superblock on 2nd try");
4493 			ret = PTR_ERR(bh);
4494 			bh = NULL;
4495 			goto failed_mount;
4496 		}
4497 		es = (struct ext4_super_block *)(bh->b_data + offset);
4498 		sbi->s_es = es;
4499 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4500 			ext4_msg(sb, KERN_ERR,
4501 			       "Magic mismatch, very weird!");
4502 			goto failed_mount;
4503 		}
4504 	}
4505 
4506 	has_huge_files = ext4_has_feature_huge_file(sb);
4507 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4508 						      has_huge_files);
4509 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4510 
4511 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4512 	if (ext4_has_feature_64bit(sb)) {
4513 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4514 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4515 		    !is_power_of_2(sbi->s_desc_size)) {
4516 			ext4_msg(sb, KERN_ERR,
4517 			       "unsupported descriptor size %lu",
4518 			       sbi->s_desc_size);
4519 			goto failed_mount;
4520 		}
4521 	} else
4522 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4523 
4524 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4525 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4526 
4527 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4528 	if (sbi->s_inodes_per_block == 0)
4529 		goto cantfind_ext4;
4530 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4531 	    sbi->s_inodes_per_group > blocksize * 8) {
4532 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4533 			 sbi->s_inodes_per_group);
4534 		goto failed_mount;
4535 	}
4536 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4537 					sbi->s_inodes_per_block;
4538 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4539 	sbi->s_sbh = bh;
4540 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4541 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4542 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4543 
4544 	for (i = 0; i < 4; i++)
4545 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4546 	sbi->s_def_hash_version = es->s_def_hash_version;
4547 	if (ext4_has_feature_dir_index(sb)) {
4548 		i = le32_to_cpu(es->s_flags);
4549 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4550 			sbi->s_hash_unsigned = 3;
4551 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4552 #ifdef __CHAR_UNSIGNED__
4553 			if (!sb_rdonly(sb))
4554 				es->s_flags |=
4555 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4556 			sbi->s_hash_unsigned = 3;
4557 #else
4558 			if (!sb_rdonly(sb))
4559 				es->s_flags |=
4560 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4561 #endif
4562 		}
4563 	}
4564 
4565 	/* Handle clustersize */
4566 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4567 	if (ext4_has_feature_bigalloc(sb)) {
4568 		if (clustersize < blocksize) {
4569 			ext4_msg(sb, KERN_ERR,
4570 				 "cluster size (%d) smaller than "
4571 				 "block size (%d)", clustersize, blocksize);
4572 			goto failed_mount;
4573 		}
4574 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4575 			le32_to_cpu(es->s_log_block_size);
4576 		sbi->s_clusters_per_group =
4577 			le32_to_cpu(es->s_clusters_per_group);
4578 		if (sbi->s_clusters_per_group > blocksize * 8) {
4579 			ext4_msg(sb, KERN_ERR,
4580 				 "#clusters per group too big: %lu",
4581 				 sbi->s_clusters_per_group);
4582 			goto failed_mount;
4583 		}
4584 		if (sbi->s_blocks_per_group !=
4585 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4586 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4587 				 "clusters per group (%lu) inconsistent",
4588 				 sbi->s_blocks_per_group,
4589 				 sbi->s_clusters_per_group);
4590 			goto failed_mount;
4591 		}
4592 	} else {
4593 		if (clustersize != blocksize) {
4594 			ext4_msg(sb, KERN_ERR,
4595 				 "fragment/cluster size (%d) != "
4596 				 "block size (%d)", clustersize, blocksize);
4597 			goto failed_mount;
4598 		}
4599 		if (sbi->s_blocks_per_group > blocksize * 8) {
4600 			ext4_msg(sb, KERN_ERR,
4601 				 "#blocks per group too big: %lu",
4602 				 sbi->s_blocks_per_group);
4603 			goto failed_mount;
4604 		}
4605 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4606 		sbi->s_cluster_bits = 0;
4607 	}
4608 	sbi->s_cluster_ratio = clustersize / blocksize;
4609 
4610 	/* Do we have standard group size of clustersize * 8 blocks ? */
4611 	if (sbi->s_blocks_per_group == clustersize << 3)
4612 		set_opt2(sb, STD_GROUP_SIZE);
4613 
4614 	/*
4615 	 * Test whether we have more sectors than will fit in sector_t,
4616 	 * and whether the max offset is addressable by the page cache.
4617 	 */
4618 	err = generic_check_addressable(sb->s_blocksize_bits,
4619 					ext4_blocks_count(es));
4620 	if (err) {
4621 		ext4_msg(sb, KERN_ERR, "filesystem"
4622 			 " too large to mount safely on this system");
4623 		goto failed_mount;
4624 	}
4625 
4626 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4627 		goto cantfind_ext4;
4628 
4629 	/* check blocks count against device size */
4630 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4631 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4632 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4633 		       "exceeds size of device (%llu blocks)",
4634 		       ext4_blocks_count(es), blocks_count);
4635 		goto failed_mount;
4636 	}
4637 
4638 	/*
4639 	 * It makes no sense for the first data block to be beyond the end
4640 	 * of the filesystem.
4641 	 */
4642 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4643 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4644 			 "block %u is beyond end of filesystem (%llu)",
4645 			 le32_to_cpu(es->s_first_data_block),
4646 			 ext4_blocks_count(es));
4647 		goto failed_mount;
4648 	}
4649 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4650 	    (sbi->s_cluster_ratio == 1)) {
4651 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4652 			 "block is 0 with a 1k block and cluster size");
4653 		goto failed_mount;
4654 	}
4655 
4656 	blocks_count = (ext4_blocks_count(es) -
4657 			le32_to_cpu(es->s_first_data_block) +
4658 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4659 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4660 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4661 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4662 		       "(block count %llu, first data block %u, "
4663 		       "blocks per group %lu)", blocks_count,
4664 		       ext4_blocks_count(es),
4665 		       le32_to_cpu(es->s_first_data_block),
4666 		       EXT4_BLOCKS_PER_GROUP(sb));
4667 		goto failed_mount;
4668 	}
4669 	sbi->s_groups_count = blocks_count;
4670 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4671 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4672 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4673 	    le32_to_cpu(es->s_inodes_count)) {
4674 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4675 			 le32_to_cpu(es->s_inodes_count),
4676 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4677 		ret = -EINVAL;
4678 		goto failed_mount;
4679 	}
4680 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4681 		   EXT4_DESC_PER_BLOCK(sb);
4682 	if (ext4_has_feature_meta_bg(sb)) {
4683 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4684 			ext4_msg(sb, KERN_WARNING,
4685 				 "first meta block group too large: %u "
4686 				 "(group descriptor block count %u)",
4687 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4688 			goto failed_mount;
4689 		}
4690 	}
4691 	rcu_assign_pointer(sbi->s_group_desc,
4692 			   kvmalloc_array(db_count,
4693 					  sizeof(struct buffer_head *),
4694 					  GFP_KERNEL));
4695 	if (sbi->s_group_desc == NULL) {
4696 		ext4_msg(sb, KERN_ERR, "not enough memory");
4697 		ret = -ENOMEM;
4698 		goto failed_mount;
4699 	}
4700 
4701 	bgl_lock_init(sbi->s_blockgroup_lock);
4702 
4703 	/* Pre-read the descriptors into the buffer cache */
4704 	for (i = 0; i < db_count; i++) {
4705 		block = descriptor_loc(sb, logical_sb_block, i);
4706 		ext4_sb_breadahead_unmovable(sb, block);
4707 	}
4708 
4709 	for (i = 0; i < db_count; i++) {
4710 		struct buffer_head *bh;
4711 
4712 		block = descriptor_loc(sb, logical_sb_block, i);
4713 		bh = ext4_sb_bread_unmovable(sb, block);
4714 		if (IS_ERR(bh)) {
4715 			ext4_msg(sb, KERN_ERR,
4716 			       "can't read group descriptor %d", i);
4717 			db_count = i;
4718 			ret = PTR_ERR(bh);
4719 			goto failed_mount2;
4720 		}
4721 		rcu_read_lock();
4722 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4723 		rcu_read_unlock();
4724 	}
4725 	sbi->s_gdb_count = db_count;
4726 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4727 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4728 		ret = -EFSCORRUPTED;
4729 		goto failed_mount2;
4730 	}
4731 
4732 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4733 	spin_lock_init(&sbi->s_error_lock);
4734 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
4735 
4736 	/* Register extent status tree shrinker */
4737 	if (ext4_es_register_shrinker(sbi))
4738 		goto failed_mount3;
4739 
4740 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4741 	sbi->s_extent_max_zeroout_kb = 32;
4742 
4743 	/*
4744 	 * set up enough so that it can read an inode
4745 	 */
4746 	sb->s_op = &ext4_sops;
4747 	sb->s_export_op = &ext4_export_ops;
4748 	sb->s_xattr = ext4_xattr_handlers;
4749 #ifdef CONFIG_FS_ENCRYPTION
4750 	sb->s_cop = &ext4_cryptops;
4751 #endif
4752 #ifdef CONFIG_FS_VERITY
4753 	sb->s_vop = &ext4_verityops;
4754 #endif
4755 #ifdef CONFIG_QUOTA
4756 	sb->dq_op = &ext4_quota_operations;
4757 	if (ext4_has_feature_quota(sb))
4758 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4759 	else
4760 		sb->s_qcop = &ext4_qctl_operations;
4761 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4762 #endif
4763 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4764 
4765 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4766 	mutex_init(&sbi->s_orphan_lock);
4767 
4768 	/* Initialize fast commit stuff */
4769 	atomic_set(&sbi->s_fc_subtid, 0);
4770 	atomic_set(&sbi->s_fc_ineligible_updates, 0);
4771 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4772 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4773 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4774 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4775 	sbi->s_fc_bytes = 0;
4776 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4777 	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
4778 	spin_lock_init(&sbi->s_fc_lock);
4779 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4780 	sbi->s_fc_replay_state.fc_regions = NULL;
4781 	sbi->s_fc_replay_state.fc_regions_size = 0;
4782 	sbi->s_fc_replay_state.fc_regions_used = 0;
4783 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4784 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4785 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4786 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4787 
4788 	sb->s_root = NULL;
4789 
4790 	needs_recovery = (es->s_last_orphan != 0 ||
4791 			  ext4_has_feature_journal_needs_recovery(sb));
4792 
4793 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4794 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4795 			goto failed_mount3a;
4796 
4797 	/*
4798 	 * The first inode we look at is the journal inode.  Don't try
4799 	 * root first: it may be modified in the journal!
4800 	 */
4801 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4802 		err = ext4_load_journal(sb, es, parsed_opts.journal_devnum);
4803 		if (err)
4804 			goto failed_mount3a;
4805 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4806 		   ext4_has_feature_journal_needs_recovery(sb)) {
4807 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4808 		       "suppressed and not mounted read-only");
4809 		goto failed_mount_wq;
4810 	} else {
4811 		/* Nojournal mode, all journal mount options are illegal */
4812 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4813 			ext4_msg(sb, KERN_ERR, "can't mount with "
4814 				 "journal_checksum, fs mounted w/o journal");
4815 			goto failed_mount_wq;
4816 		}
4817 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4818 			ext4_msg(sb, KERN_ERR, "can't mount with "
4819 				 "journal_async_commit, fs mounted w/o journal");
4820 			goto failed_mount_wq;
4821 		}
4822 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4823 			ext4_msg(sb, KERN_ERR, "can't mount with "
4824 				 "commit=%lu, fs mounted w/o journal",
4825 				 sbi->s_commit_interval / HZ);
4826 			goto failed_mount_wq;
4827 		}
4828 		if (EXT4_MOUNT_DATA_FLAGS &
4829 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4830 			ext4_msg(sb, KERN_ERR, "can't mount with "
4831 				 "data=, fs mounted w/o journal");
4832 			goto failed_mount_wq;
4833 		}
4834 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4835 		clear_opt(sb, JOURNAL_CHECKSUM);
4836 		clear_opt(sb, DATA_FLAGS);
4837 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4838 		sbi->s_journal = NULL;
4839 		needs_recovery = 0;
4840 		goto no_journal;
4841 	}
4842 
4843 	if (ext4_has_feature_64bit(sb) &&
4844 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4845 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4846 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4847 		goto failed_mount_wq;
4848 	}
4849 
4850 	if (!set_journal_csum_feature_set(sb)) {
4851 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4852 			 "feature set");
4853 		goto failed_mount_wq;
4854 	}
4855 
4856 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4857 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4858 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4859 		ext4_msg(sb, KERN_ERR,
4860 			"Failed to set fast commit journal feature");
4861 		goto failed_mount_wq;
4862 	}
4863 
4864 	/* We have now updated the journal if required, so we can
4865 	 * validate the data journaling mode. */
4866 	switch (test_opt(sb, DATA_FLAGS)) {
4867 	case 0:
4868 		/* No mode set, assume a default based on the journal
4869 		 * capabilities: ORDERED_DATA if the journal can
4870 		 * cope, else JOURNAL_DATA
4871 		 */
4872 		if (jbd2_journal_check_available_features
4873 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4874 			set_opt(sb, ORDERED_DATA);
4875 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4876 		} else {
4877 			set_opt(sb, JOURNAL_DATA);
4878 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4879 		}
4880 		break;
4881 
4882 	case EXT4_MOUNT_ORDERED_DATA:
4883 	case EXT4_MOUNT_WRITEBACK_DATA:
4884 		if (!jbd2_journal_check_available_features
4885 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4886 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4887 			       "requested data journaling mode");
4888 			goto failed_mount_wq;
4889 		}
4890 		break;
4891 	default:
4892 		break;
4893 	}
4894 
4895 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4896 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4897 		ext4_msg(sb, KERN_ERR, "can't mount with "
4898 			"journal_async_commit in data=ordered mode");
4899 		goto failed_mount_wq;
4900 	}
4901 
4902 	set_task_ioprio(sbi->s_journal->j_task, parsed_opts.journal_ioprio);
4903 
4904 	sbi->s_journal->j_submit_inode_data_buffers =
4905 		ext4_journal_submit_inode_data_buffers;
4906 	sbi->s_journal->j_finish_inode_data_buffers =
4907 		ext4_journal_finish_inode_data_buffers;
4908 
4909 no_journal:
4910 	if (!test_opt(sb, NO_MBCACHE)) {
4911 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4912 		if (!sbi->s_ea_block_cache) {
4913 			ext4_msg(sb, KERN_ERR,
4914 				 "Failed to create ea_block_cache");
4915 			goto failed_mount_wq;
4916 		}
4917 
4918 		if (ext4_has_feature_ea_inode(sb)) {
4919 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4920 			if (!sbi->s_ea_inode_cache) {
4921 				ext4_msg(sb, KERN_ERR,
4922 					 "Failed to create ea_inode_cache");
4923 				goto failed_mount_wq;
4924 			}
4925 		}
4926 	}
4927 
4928 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4929 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4930 		goto failed_mount_wq;
4931 	}
4932 
4933 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4934 	    !ext4_has_feature_encrypt(sb)) {
4935 		ext4_set_feature_encrypt(sb);
4936 		ext4_commit_super(sb);
4937 	}
4938 
4939 	/*
4940 	 * Get the # of file system overhead blocks from the
4941 	 * superblock if present.
4942 	 */
4943 	if (es->s_overhead_clusters)
4944 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4945 	else {
4946 		err = ext4_calculate_overhead(sb);
4947 		if (err)
4948 			goto failed_mount_wq;
4949 	}
4950 
4951 	/*
4952 	 * The maximum number of concurrent works can be high and
4953 	 * concurrency isn't really necessary.  Limit it to 1.
4954 	 */
4955 	EXT4_SB(sb)->rsv_conversion_wq =
4956 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4957 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4958 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4959 		ret = -ENOMEM;
4960 		goto failed_mount4;
4961 	}
4962 
4963 	/*
4964 	 * The jbd2_journal_load will have done any necessary log recovery,
4965 	 * so we can safely mount the rest of the filesystem now.
4966 	 */
4967 
4968 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4969 	if (IS_ERR(root)) {
4970 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4971 		ret = PTR_ERR(root);
4972 		root = NULL;
4973 		goto failed_mount4;
4974 	}
4975 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4976 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4977 		iput(root);
4978 		goto failed_mount4;
4979 	}
4980 
4981 	sb->s_root = d_make_root(root);
4982 	if (!sb->s_root) {
4983 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4984 		ret = -ENOMEM;
4985 		goto failed_mount4;
4986 	}
4987 
4988 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4989 	if (ret == -EROFS) {
4990 		sb->s_flags |= SB_RDONLY;
4991 		ret = 0;
4992 	} else if (ret)
4993 		goto failed_mount4a;
4994 
4995 	ext4_set_resv_clusters(sb);
4996 
4997 	if (test_opt(sb, BLOCK_VALIDITY)) {
4998 		err = ext4_setup_system_zone(sb);
4999 		if (err) {
5000 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5001 				 "zone (%d)", err);
5002 			goto failed_mount4a;
5003 		}
5004 	}
5005 	ext4_fc_replay_cleanup(sb);
5006 
5007 	ext4_ext_init(sb);
5008 
5009 	/*
5010 	 * Enable optimize_scan if number of groups is > threshold. This can be
5011 	 * turned off by passing "mb_optimize_scan=0". This can also be
5012 	 * turned on forcefully by passing "mb_optimize_scan=1".
5013 	 */
5014 	if (parsed_opts.mb_optimize_scan == 1)
5015 		set_opt2(sb, MB_OPTIMIZE_SCAN);
5016 	else if (parsed_opts.mb_optimize_scan == 0)
5017 		clear_opt2(sb, MB_OPTIMIZE_SCAN);
5018 	else if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5019 		set_opt2(sb, MB_OPTIMIZE_SCAN);
5020 
5021 	err = ext4_mb_init(sb);
5022 	if (err) {
5023 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5024 			 err);
5025 		goto failed_mount5;
5026 	}
5027 
5028 	/*
5029 	 * We can only set up the journal commit callback once
5030 	 * mballoc is initialized
5031 	 */
5032 	if (sbi->s_journal)
5033 		sbi->s_journal->j_commit_callback =
5034 			ext4_journal_commit_callback;
5035 
5036 	block = ext4_count_free_clusters(sb);
5037 	ext4_free_blocks_count_set(sbi->s_es,
5038 				   EXT4_C2B(sbi, block));
5039 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5040 				  GFP_KERNEL);
5041 	if (!err) {
5042 		unsigned long freei = ext4_count_free_inodes(sb);
5043 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5044 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5045 					  GFP_KERNEL);
5046 	}
5047 	if (!err)
5048 		err = percpu_counter_init(&sbi->s_dirs_counter,
5049 					  ext4_count_dirs(sb), GFP_KERNEL);
5050 	if (!err)
5051 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5052 					  GFP_KERNEL);
5053 	if (!err)
5054 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5055 					  GFP_KERNEL);
5056 	if (!err)
5057 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5058 
5059 	if (err) {
5060 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5061 		goto failed_mount6;
5062 	}
5063 
5064 	if (ext4_has_feature_flex_bg(sb))
5065 		if (!ext4_fill_flex_info(sb)) {
5066 			ext4_msg(sb, KERN_ERR,
5067 			       "unable to initialize "
5068 			       "flex_bg meta info!");
5069 			ret = -ENOMEM;
5070 			goto failed_mount6;
5071 		}
5072 
5073 	err = ext4_register_li_request(sb, first_not_zeroed);
5074 	if (err)
5075 		goto failed_mount6;
5076 
5077 	err = ext4_register_sysfs(sb);
5078 	if (err)
5079 		goto failed_mount7;
5080 
5081 #ifdef CONFIG_QUOTA
5082 	/* Enable quota usage during mount. */
5083 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5084 		err = ext4_enable_quotas(sb);
5085 		if (err)
5086 			goto failed_mount8;
5087 	}
5088 #endif  /* CONFIG_QUOTA */
5089 
5090 	/*
5091 	 * Save the original bdev mapping's wb_err value which could be
5092 	 * used to detect the metadata async write error.
5093 	 */
5094 	spin_lock_init(&sbi->s_bdev_wb_lock);
5095 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5096 				 &sbi->s_bdev_wb_err);
5097 	sb->s_bdev->bd_super = sb;
5098 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5099 	ext4_orphan_cleanup(sb, es);
5100 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5101 	if (needs_recovery) {
5102 		ext4_msg(sb, KERN_INFO, "recovery complete");
5103 		err = ext4_mark_recovery_complete(sb, es);
5104 		if (err)
5105 			goto failed_mount8;
5106 	}
5107 	if (EXT4_SB(sb)->s_journal) {
5108 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5109 			descr = " journalled data mode";
5110 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5111 			descr = " ordered data mode";
5112 		else
5113 			descr = " writeback data mode";
5114 	} else
5115 		descr = "out journal";
5116 
5117 	if (test_opt(sb, DISCARD)) {
5118 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5119 		if (!blk_queue_discard(q))
5120 			ext4_msg(sb, KERN_WARNING,
5121 				 "mounting with \"discard\" option, but "
5122 				 "the device does not support discard");
5123 	}
5124 
5125 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5126 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5127 			 "Opts: %.*s%s%s. Quota mode: %s.", descr,
5128 			 (int) sizeof(sbi->s_es->s_mount_opts),
5129 			 sbi->s_es->s_mount_opts,
5130 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data,
5131 			 ext4_quota_mode(sb));
5132 
5133 	if (es->s_error_count)
5134 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5135 
5136 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5137 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5138 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5139 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5140 	atomic_set(&sbi->s_warning_count, 0);
5141 	atomic_set(&sbi->s_msg_count, 0);
5142 
5143 	kfree(orig_data);
5144 	return 0;
5145 
5146 cantfind_ext4:
5147 	if (!silent)
5148 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5149 	goto failed_mount;
5150 
5151 failed_mount8:
5152 	ext4_unregister_sysfs(sb);
5153 	kobject_put(&sbi->s_kobj);
5154 failed_mount7:
5155 	ext4_unregister_li_request(sb);
5156 failed_mount6:
5157 	ext4_mb_release(sb);
5158 	rcu_read_lock();
5159 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5160 	if (flex_groups) {
5161 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5162 			kvfree(flex_groups[i]);
5163 		kvfree(flex_groups);
5164 	}
5165 	rcu_read_unlock();
5166 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5167 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5168 	percpu_counter_destroy(&sbi->s_dirs_counter);
5169 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5170 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5171 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5172 failed_mount5:
5173 	ext4_ext_release(sb);
5174 	ext4_release_system_zone(sb);
5175 failed_mount4a:
5176 	dput(sb->s_root);
5177 	sb->s_root = NULL;
5178 failed_mount4:
5179 	ext4_msg(sb, KERN_ERR, "mount failed");
5180 	if (EXT4_SB(sb)->rsv_conversion_wq)
5181 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5182 failed_mount_wq:
5183 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5184 	sbi->s_ea_inode_cache = NULL;
5185 
5186 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5187 	sbi->s_ea_block_cache = NULL;
5188 
5189 	if (sbi->s_journal) {
5190 		jbd2_journal_unregister_shrinker(sbi->s_journal);
5191 		jbd2_journal_destroy(sbi->s_journal);
5192 		sbi->s_journal = NULL;
5193 	}
5194 failed_mount3a:
5195 	ext4_es_unregister_shrinker(sbi);
5196 failed_mount3:
5197 	flush_work(&sbi->s_error_work);
5198 	del_timer_sync(&sbi->s_err_report);
5199 	ext4_stop_mmpd(sbi);
5200 failed_mount2:
5201 	rcu_read_lock();
5202 	group_desc = rcu_dereference(sbi->s_group_desc);
5203 	for (i = 0; i < db_count; i++)
5204 		brelse(group_desc[i]);
5205 	kvfree(group_desc);
5206 	rcu_read_unlock();
5207 failed_mount:
5208 	if (sbi->s_chksum_driver)
5209 		crypto_free_shash(sbi->s_chksum_driver);
5210 
5211 #ifdef CONFIG_UNICODE
5212 	utf8_unload(sb->s_encoding);
5213 #endif
5214 
5215 #ifdef CONFIG_QUOTA
5216 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5217 		kfree(get_qf_name(sb, sbi, i));
5218 #endif
5219 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5220 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5221 	brelse(bh);
5222 	ext4_blkdev_remove(sbi);
5223 out_fail:
5224 	sb->s_fs_info = NULL;
5225 	kfree(sbi->s_blockgroup_lock);
5226 out_free_base:
5227 	kfree(sbi);
5228 	kfree(orig_data);
5229 	fs_put_dax(dax_dev);
5230 	return err ? err : ret;
5231 }
5232 
5233 /*
5234  * Setup any per-fs journal parameters now.  We'll do this both on
5235  * initial mount, once the journal has been initialised but before we've
5236  * done any recovery; and again on any subsequent remount.
5237  */
5238 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5239 {
5240 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5241 
5242 	journal->j_commit_interval = sbi->s_commit_interval;
5243 	journal->j_min_batch_time = sbi->s_min_batch_time;
5244 	journal->j_max_batch_time = sbi->s_max_batch_time;
5245 	ext4_fc_init(sb, journal);
5246 
5247 	write_lock(&journal->j_state_lock);
5248 	if (test_opt(sb, BARRIER))
5249 		journal->j_flags |= JBD2_BARRIER;
5250 	else
5251 		journal->j_flags &= ~JBD2_BARRIER;
5252 	if (test_opt(sb, DATA_ERR_ABORT))
5253 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5254 	else
5255 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5256 	write_unlock(&journal->j_state_lock);
5257 }
5258 
5259 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5260 					     unsigned int journal_inum)
5261 {
5262 	struct inode *journal_inode;
5263 
5264 	/*
5265 	 * Test for the existence of a valid inode on disk.  Bad things
5266 	 * happen if we iget() an unused inode, as the subsequent iput()
5267 	 * will try to delete it.
5268 	 */
5269 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5270 	if (IS_ERR(journal_inode)) {
5271 		ext4_msg(sb, KERN_ERR, "no journal found");
5272 		return NULL;
5273 	}
5274 	if (!journal_inode->i_nlink) {
5275 		make_bad_inode(journal_inode);
5276 		iput(journal_inode);
5277 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5278 		return NULL;
5279 	}
5280 
5281 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5282 		  journal_inode, journal_inode->i_size);
5283 	if (!S_ISREG(journal_inode->i_mode)) {
5284 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5285 		iput(journal_inode);
5286 		return NULL;
5287 	}
5288 	return journal_inode;
5289 }
5290 
5291 static journal_t *ext4_get_journal(struct super_block *sb,
5292 				   unsigned int journal_inum)
5293 {
5294 	struct inode *journal_inode;
5295 	journal_t *journal;
5296 
5297 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5298 		return NULL;
5299 
5300 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5301 	if (!journal_inode)
5302 		return NULL;
5303 
5304 	journal = jbd2_journal_init_inode(journal_inode);
5305 	if (!journal) {
5306 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5307 		iput(journal_inode);
5308 		return NULL;
5309 	}
5310 	journal->j_private = sb;
5311 	ext4_init_journal_params(sb, journal);
5312 	return journal;
5313 }
5314 
5315 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5316 				       dev_t j_dev)
5317 {
5318 	struct buffer_head *bh;
5319 	journal_t *journal;
5320 	ext4_fsblk_t start;
5321 	ext4_fsblk_t len;
5322 	int hblock, blocksize;
5323 	ext4_fsblk_t sb_block;
5324 	unsigned long offset;
5325 	struct ext4_super_block *es;
5326 	struct block_device *bdev;
5327 
5328 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5329 		return NULL;
5330 
5331 	bdev = ext4_blkdev_get(j_dev, sb);
5332 	if (bdev == NULL)
5333 		return NULL;
5334 
5335 	blocksize = sb->s_blocksize;
5336 	hblock = bdev_logical_block_size(bdev);
5337 	if (blocksize < hblock) {
5338 		ext4_msg(sb, KERN_ERR,
5339 			"blocksize too small for journal device");
5340 		goto out_bdev;
5341 	}
5342 
5343 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5344 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5345 	set_blocksize(bdev, blocksize);
5346 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5347 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5348 		       "external journal");
5349 		goto out_bdev;
5350 	}
5351 
5352 	es = (struct ext4_super_block *) (bh->b_data + offset);
5353 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5354 	    !(le32_to_cpu(es->s_feature_incompat) &
5355 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5356 		ext4_msg(sb, KERN_ERR, "external journal has "
5357 					"bad superblock");
5358 		brelse(bh);
5359 		goto out_bdev;
5360 	}
5361 
5362 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5363 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5364 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5365 		ext4_msg(sb, KERN_ERR, "external journal has "
5366 				       "corrupt superblock");
5367 		brelse(bh);
5368 		goto out_bdev;
5369 	}
5370 
5371 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5372 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5373 		brelse(bh);
5374 		goto out_bdev;
5375 	}
5376 
5377 	len = ext4_blocks_count(es);
5378 	start = sb_block + 1;
5379 	brelse(bh);	/* we're done with the superblock */
5380 
5381 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5382 					start, len, blocksize);
5383 	if (!journal) {
5384 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5385 		goto out_bdev;
5386 	}
5387 	journal->j_private = sb;
5388 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5389 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5390 		goto out_journal;
5391 	}
5392 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5393 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5394 					"user (unsupported) - %d",
5395 			be32_to_cpu(journal->j_superblock->s_nr_users));
5396 		goto out_journal;
5397 	}
5398 	EXT4_SB(sb)->s_journal_bdev = bdev;
5399 	ext4_init_journal_params(sb, journal);
5400 	return journal;
5401 
5402 out_journal:
5403 	jbd2_journal_destroy(journal);
5404 out_bdev:
5405 	ext4_blkdev_put(bdev);
5406 	return NULL;
5407 }
5408 
5409 static int ext4_load_journal(struct super_block *sb,
5410 			     struct ext4_super_block *es,
5411 			     unsigned long journal_devnum)
5412 {
5413 	journal_t *journal;
5414 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5415 	dev_t journal_dev;
5416 	int err = 0;
5417 	int really_read_only;
5418 	int journal_dev_ro;
5419 
5420 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5421 		return -EFSCORRUPTED;
5422 
5423 	if (journal_devnum &&
5424 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5425 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5426 			"numbers have changed");
5427 		journal_dev = new_decode_dev(journal_devnum);
5428 	} else
5429 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5430 
5431 	if (journal_inum && journal_dev) {
5432 		ext4_msg(sb, KERN_ERR,
5433 			 "filesystem has both journal inode and journal device!");
5434 		return -EINVAL;
5435 	}
5436 
5437 	if (journal_inum) {
5438 		journal = ext4_get_journal(sb, journal_inum);
5439 		if (!journal)
5440 			return -EINVAL;
5441 	} else {
5442 		journal = ext4_get_dev_journal(sb, journal_dev);
5443 		if (!journal)
5444 			return -EINVAL;
5445 	}
5446 
5447 	journal_dev_ro = bdev_read_only(journal->j_dev);
5448 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5449 
5450 	if (journal_dev_ro && !sb_rdonly(sb)) {
5451 		ext4_msg(sb, KERN_ERR,
5452 			 "journal device read-only, try mounting with '-o ro'");
5453 		err = -EROFS;
5454 		goto err_out;
5455 	}
5456 
5457 	/*
5458 	 * Are we loading a blank journal or performing recovery after a
5459 	 * crash?  For recovery, we need to check in advance whether we
5460 	 * can get read-write access to the device.
5461 	 */
5462 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5463 		if (sb_rdonly(sb)) {
5464 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5465 					"required on readonly filesystem");
5466 			if (really_read_only) {
5467 				ext4_msg(sb, KERN_ERR, "write access "
5468 					"unavailable, cannot proceed "
5469 					"(try mounting with noload)");
5470 				err = -EROFS;
5471 				goto err_out;
5472 			}
5473 			ext4_msg(sb, KERN_INFO, "write access will "
5474 			       "be enabled during recovery");
5475 		}
5476 	}
5477 
5478 	if (!(journal->j_flags & JBD2_BARRIER))
5479 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5480 
5481 	if (!ext4_has_feature_journal_needs_recovery(sb))
5482 		err = jbd2_journal_wipe(journal, !really_read_only);
5483 	if (!err) {
5484 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5485 		if (save)
5486 			memcpy(save, ((char *) es) +
5487 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5488 		err = jbd2_journal_load(journal);
5489 		if (save)
5490 			memcpy(((char *) es) + EXT4_S_ERR_START,
5491 			       save, EXT4_S_ERR_LEN);
5492 		kfree(save);
5493 	}
5494 
5495 	if (err) {
5496 		ext4_msg(sb, KERN_ERR, "error loading journal");
5497 		goto err_out;
5498 	}
5499 
5500 	EXT4_SB(sb)->s_journal = journal;
5501 	err = ext4_clear_journal_err(sb, es);
5502 	if (err) {
5503 		EXT4_SB(sb)->s_journal = NULL;
5504 		jbd2_journal_destroy(journal);
5505 		return err;
5506 	}
5507 
5508 	if (!really_read_only && journal_devnum &&
5509 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5510 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5511 
5512 		/* Make sure we flush the recovery flag to disk. */
5513 		ext4_commit_super(sb);
5514 	}
5515 
5516 	err = jbd2_journal_register_shrinker(journal);
5517 	if (err) {
5518 		EXT4_SB(sb)->s_journal = NULL;
5519 		goto err_out;
5520 	}
5521 
5522 	return 0;
5523 
5524 err_out:
5525 	jbd2_journal_destroy(journal);
5526 	return err;
5527 }
5528 
5529 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5530 static void ext4_update_super(struct super_block *sb)
5531 {
5532 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5533 	struct ext4_super_block *es = sbi->s_es;
5534 	struct buffer_head *sbh = sbi->s_sbh;
5535 
5536 	lock_buffer(sbh);
5537 	/*
5538 	 * If the file system is mounted read-only, don't update the
5539 	 * superblock write time.  This avoids updating the superblock
5540 	 * write time when we are mounting the root file system
5541 	 * read/only but we need to replay the journal; at that point,
5542 	 * for people who are east of GMT and who make their clock
5543 	 * tick in localtime for Windows bug-for-bug compatibility,
5544 	 * the clock is set in the future, and this will cause e2fsck
5545 	 * to complain and force a full file system check.
5546 	 */
5547 	if (!(sb->s_flags & SB_RDONLY))
5548 		ext4_update_tstamp(es, s_wtime);
5549 	es->s_kbytes_written =
5550 		cpu_to_le64(sbi->s_kbytes_written +
5551 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5552 		      sbi->s_sectors_written_start) >> 1));
5553 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5554 		ext4_free_blocks_count_set(es,
5555 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5556 				&sbi->s_freeclusters_counter)));
5557 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5558 		es->s_free_inodes_count =
5559 			cpu_to_le32(percpu_counter_sum_positive(
5560 				&sbi->s_freeinodes_counter));
5561 	/* Copy error information to the on-disk superblock */
5562 	spin_lock(&sbi->s_error_lock);
5563 	if (sbi->s_add_error_count > 0) {
5564 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5565 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5566 			__ext4_update_tstamp(&es->s_first_error_time,
5567 					     &es->s_first_error_time_hi,
5568 					     sbi->s_first_error_time);
5569 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5570 				sizeof(es->s_first_error_func));
5571 			es->s_first_error_line =
5572 				cpu_to_le32(sbi->s_first_error_line);
5573 			es->s_first_error_ino =
5574 				cpu_to_le32(sbi->s_first_error_ino);
5575 			es->s_first_error_block =
5576 				cpu_to_le64(sbi->s_first_error_block);
5577 			es->s_first_error_errcode =
5578 				ext4_errno_to_code(sbi->s_first_error_code);
5579 		}
5580 		__ext4_update_tstamp(&es->s_last_error_time,
5581 				     &es->s_last_error_time_hi,
5582 				     sbi->s_last_error_time);
5583 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5584 			sizeof(es->s_last_error_func));
5585 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5586 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5587 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5588 		es->s_last_error_errcode =
5589 				ext4_errno_to_code(sbi->s_last_error_code);
5590 		/*
5591 		 * Start the daily error reporting function if it hasn't been
5592 		 * started already
5593 		 */
5594 		if (!es->s_error_count)
5595 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5596 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5597 		sbi->s_add_error_count = 0;
5598 	}
5599 	spin_unlock(&sbi->s_error_lock);
5600 
5601 	ext4_superblock_csum_set(sb);
5602 	unlock_buffer(sbh);
5603 }
5604 
5605 static int ext4_commit_super(struct super_block *sb)
5606 {
5607 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5608 	int error = 0;
5609 
5610 	if (!sbh)
5611 		return -EINVAL;
5612 	if (block_device_ejected(sb))
5613 		return -ENODEV;
5614 
5615 	ext4_update_super(sb);
5616 
5617 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5618 		/*
5619 		 * Oh, dear.  A previous attempt to write the
5620 		 * superblock failed.  This could happen because the
5621 		 * USB device was yanked out.  Or it could happen to
5622 		 * be a transient write error and maybe the block will
5623 		 * be remapped.  Nothing we can do but to retry the
5624 		 * write and hope for the best.
5625 		 */
5626 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5627 		       "superblock detected");
5628 		clear_buffer_write_io_error(sbh);
5629 		set_buffer_uptodate(sbh);
5630 	}
5631 	BUFFER_TRACE(sbh, "marking dirty");
5632 	mark_buffer_dirty(sbh);
5633 	error = __sync_dirty_buffer(sbh,
5634 		REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5635 	if (buffer_write_io_error(sbh)) {
5636 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
5637 		       "superblock");
5638 		clear_buffer_write_io_error(sbh);
5639 		set_buffer_uptodate(sbh);
5640 	}
5641 	return error;
5642 }
5643 
5644 /*
5645  * Have we just finished recovery?  If so, and if we are mounting (or
5646  * remounting) the filesystem readonly, then we will end up with a
5647  * consistent fs on disk.  Record that fact.
5648  */
5649 static int ext4_mark_recovery_complete(struct super_block *sb,
5650 				       struct ext4_super_block *es)
5651 {
5652 	int err;
5653 	journal_t *journal = EXT4_SB(sb)->s_journal;
5654 
5655 	if (!ext4_has_feature_journal(sb)) {
5656 		if (journal != NULL) {
5657 			ext4_error(sb, "Journal got removed while the fs was "
5658 				   "mounted!");
5659 			return -EFSCORRUPTED;
5660 		}
5661 		return 0;
5662 	}
5663 	jbd2_journal_lock_updates(journal);
5664 	err = jbd2_journal_flush(journal, 0);
5665 	if (err < 0)
5666 		goto out;
5667 
5668 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5669 		ext4_clear_feature_journal_needs_recovery(sb);
5670 		ext4_commit_super(sb);
5671 	}
5672 out:
5673 	jbd2_journal_unlock_updates(journal);
5674 	return err;
5675 }
5676 
5677 /*
5678  * If we are mounting (or read-write remounting) a filesystem whose journal
5679  * has recorded an error from a previous lifetime, move that error to the
5680  * main filesystem now.
5681  */
5682 static int ext4_clear_journal_err(struct super_block *sb,
5683 				   struct ext4_super_block *es)
5684 {
5685 	journal_t *journal;
5686 	int j_errno;
5687 	const char *errstr;
5688 
5689 	if (!ext4_has_feature_journal(sb)) {
5690 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5691 		return -EFSCORRUPTED;
5692 	}
5693 
5694 	journal = EXT4_SB(sb)->s_journal;
5695 
5696 	/*
5697 	 * Now check for any error status which may have been recorded in the
5698 	 * journal by a prior ext4_error() or ext4_abort()
5699 	 */
5700 
5701 	j_errno = jbd2_journal_errno(journal);
5702 	if (j_errno) {
5703 		char nbuf[16];
5704 
5705 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5706 		ext4_warning(sb, "Filesystem error recorded "
5707 			     "from previous mount: %s", errstr);
5708 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5709 
5710 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5711 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5712 		ext4_commit_super(sb);
5713 
5714 		jbd2_journal_clear_err(journal);
5715 		jbd2_journal_update_sb_errno(journal);
5716 	}
5717 	return 0;
5718 }
5719 
5720 /*
5721  * Force the running and committing transactions to commit,
5722  * and wait on the commit.
5723  */
5724 int ext4_force_commit(struct super_block *sb)
5725 {
5726 	journal_t *journal;
5727 
5728 	if (sb_rdonly(sb))
5729 		return 0;
5730 
5731 	journal = EXT4_SB(sb)->s_journal;
5732 	return ext4_journal_force_commit(journal);
5733 }
5734 
5735 static int ext4_sync_fs(struct super_block *sb, int wait)
5736 {
5737 	int ret = 0;
5738 	tid_t target;
5739 	bool needs_barrier = false;
5740 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5741 
5742 	if (unlikely(ext4_forced_shutdown(sbi)))
5743 		return 0;
5744 
5745 	trace_ext4_sync_fs(sb, wait);
5746 	flush_workqueue(sbi->rsv_conversion_wq);
5747 	/*
5748 	 * Writeback quota in non-journalled quota case - journalled quota has
5749 	 * no dirty dquots
5750 	 */
5751 	dquot_writeback_dquots(sb, -1);
5752 	/*
5753 	 * Data writeback is possible w/o journal transaction, so barrier must
5754 	 * being sent at the end of the function. But we can skip it if
5755 	 * transaction_commit will do it for us.
5756 	 */
5757 	if (sbi->s_journal) {
5758 		target = jbd2_get_latest_transaction(sbi->s_journal);
5759 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5760 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5761 			needs_barrier = true;
5762 
5763 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5764 			if (wait)
5765 				ret = jbd2_log_wait_commit(sbi->s_journal,
5766 							   target);
5767 		}
5768 	} else if (wait && test_opt(sb, BARRIER))
5769 		needs_barrier = true;
5770 	if (needs_barrier) {
5771 		int err;
5772 		err = blkdev_issue_flush(sb->s_bdev);
5773 		if (!ret)
5774 			ret = err;
5775 	}
5776 
5777 	return ret;
5778 }
5779 
5780 /*
5781  * LVM calls this function before a (read-only) snapshot is created.  This
5782  * gives us a chance to flush the journal completely and mark the fs clean.
5783  *
5784  * Note that only this function cannot bring a filesystem to be in a clean
5785  * state independently. It relies on upper layer to stop all data & metadata
5786  * modifications.
5787  */
5788 static int ext4_freeze(struct super_block *sb)
5789 {
5790 	int error = 0;
5791 	journal_t *journal;
5792 
5793 	if (sb_rdonly(sb))
5794 		return 0;
5795 
5796 	journal = EXT4_SB(sb)->s_journal;
5797 
5798 	if (journal) {
5799 		/* Now we set up the journal barrier. */
5800 		jbd2_journal_lock_updates(journal);
5801 
5802 		/*
5803 		 * Don't clear the needs_recovery flag if we failed to
5804 		 * flush the journal.
5805 		 */
5806 		error = jbd2_journal_flush(journal, 0);
5807 		if (error < 0)
5808 			goto out;
5809 
5810 		/* Journal blocked and flushed, clear needs_recovery flag. */
5811 		ext4_clear_feature_journal_needs_recovery(sb);
5812 	}
5813 
5814 	error = ext4_commit_super(sb);
5815 out:
5816 	if (journal)
5817 		/* we rely on upper layer to stop further updates */
5818 		jbd2_journal_unlock_updates(journal);
5819 	return error;
5820 }
5821 
5822 /*
5823  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5824  * flag here, even though the filesystem is not technically dirty yet.
5825  */
5826 static int ext4_unfreeze(struct super_block *sb)
5827 {
5828 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5829 		return 0;
5830 
5831 	if (EXT4_SB(sb)->s_journal) {
5832 		/* Reset the needs_recovery flag before the fs is unlocked. */
5833 		ext4_set_feature_journal_needs_recovery(sb);
5834 	}
5835 
5836 	ext4_commit_super(sb);
5837 	return 0;
5838 }
5839 
5840 /*
5841  * Structure to save mount options for ext4_remount's benefit
5842  */
5843 struct ext4_mount_options {
5844 	unsigned long s_mount_opt;
5845 	unsigned long s_mount_opt2;
5846 	kuid_t s_resuid;
5847 	kgid_t s_resgid;
5848 	unsigned long s_commit_interval;
5849 	u32 s_min_batch_time, s_max_batch_time;
5850 #ifdef CONFIG_QUOTA
5851 	int s_jquota_fmt;
5852 	char *s_qf_names[EXT4_MAXQUOTAS];
5853 #endif
5854 };
5855 
5856 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5857 {
5858 	struct ext4_super_block *es;
5859 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5860 	unsigned long old_sb_flags, vfs_flags;
5861 	struct ext4_mount_options old_opts;
5862 	int enable_quota = 0;
5863 	ext4_group_t g;
5864 	int err = 0;
5865 #ifdef CONFIG_QUOTA
5866 	int i, j;
5867 	char *to_free[EXT4_MAXQUOTAS];
5868 #endif
5869 	char *orig_data = kstrdup(data, GFP_KERNEL);
5870 	struct ext4_parsed_options parsed_opts;
5871 
5872 	parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5873 	parsed_opts.journal_devnum = 0;
5874 
5875 	if (data && !orig_data)
5876 		return -ENOMEM;
5877 
5878 	/* Store the original options */
5879 	old_sb_flags = sb->s_flags;
5880 	old_opts.s_mount_opt = sbi->s_mount_opt;
5881 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5882 	old_opts.s_resuid = sbi->s_resuid;
5883 	old_opts.s_resgid = sbi->s_resgid;
5884 	old_opts.s_commit_interval = sbi->s_commit_interval;
5885 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5886 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5887 #ifdef CONFIG_QUOTA
5888 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5889 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5890 		if (sbi->s_qf_names[i]) {
5891 			char *qf_name = get_qf_name(sb, sbi, i);
5892 
5893 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5894 			if (!old_opts.s_qf_names[i]) {
5895 				for (j = 0; j < i; j++)
5896 					kfree(old_opts.s_qf_names[j]);
5897 				kfree(orig_data);
5898 				return -ENOMEM;
5899 			}
5900 		} else
5901 			old_opts.s_qf_names[i] = NULL;
5902 #endif
5903 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5904 		parsed_opts.journal_ioprio =
5905 			sbi->s_journal->j_task->io_context->ioprio;
5906 
5907 	/*
5908 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5909 	 * either way we need to make sure it matches in both *flags and
5910 	 * s_flags. Copy those selected flags from *flags to s_flags
5911 	 */
5912 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5913 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5914 
5915 	if (!parse_options(data, sb, &parsed_opts, 1)) {
5916 		err = -EINVAL;
5917 		goto restore_opts;
5918 	}
5919 
5920 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5921 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5922 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5923 			 "during remount not supported; ignoring");
5924 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5925 	}
5926 
5927 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5928 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5929 			ext4_msg(sb, KERN_ERR, "can't mount with "
5930 				 "both data=journal and delalloc");
5931 			err = -EINVAL;
5932 			goto restore_opts;
5933 		}
5934 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5935 			ext4_msg(sb, KERN_ERR, "can't mount with "
5936 				 "both data=journal and dioread_nolock");
5937 			err = -EINVAL;
5938 			goto restore_opts;
5939 		}
5940 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5941 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5942 			ext4_msg(sb, KERN_ERR, "can't mount with "
5943 				"journal_async_commit in data=ordered mode");
5944 			err = -EINVAL;
5945 			goto restore_opts;
5946 		}
5947 	}
5948 
5949 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5950 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5951 		err = -EINVAL;
5952 		goto restore_opts;
5953 	}
5954 
5955 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5956 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5957 
5958 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5959 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5960 
5961 	es = sbi->s_es;
5962 
5963 	if (sbi->s_journal) {
5964 		ext4_init_journal_params(sb, sbi->s_journal);
5965 		set_task_ioprio(sbi->s_journal->j_task, parsed_opts.journal_ioprio);
5966 	}
5967 
5968 	/* Flush outstanding errors before changing fs state */
5969 	flush_work(&sbi->s_error_work);
5970 
5971 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5972 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
5973 			err = -EROFS;
5974 			goto restore_opts;
5975 		}
5976 
5977 		if (*flags & SB_RDONLY) {
5978 			err = sync_filesystem(sb);
5979 			if (err < 0)
5980 				goto restore_opts;
5981 			err = dquot_suspend(sb, -1);
5982 			if (err < 0)
5983 				goto restore_opts;
5984 
5985 			/*
5986 			 * First of all, the unconditional stuff we have to do
5987 			 * to disable replay of the journal when we next remount
5988 			 */
5989 			sb->s_flags |= SB_RDONLY;
5990 
5991 			/*
5992 			 * OK, test if we are remounting a valid rw partition
5993 			 * readonly, and if so set the rdonly flag and then
5994 			 * mark the partition as valid again.
5995 			 */
5996 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5997 			    (sbi->s_mount_state & EXT4_VALID_FS))
5998 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5999 
6000 			if (sbi->s_journal) {
6001 				/*
6002 				 * We let remount-ro finish even if marking fs
6003 				 * as clean failed...
6004 				 */
6005 				ext4_mark_recovery_complete(sb, es);
6006 			}
6007 			ext4_stop_mmpd(sbi);
6008 		} else {
6009 			/* Make sure we can mount this feature set readwrite */
6010 			if (ext4_has_feature_readonly(sb) ||
6011 			    !ext4_feature_set_ok(sb, 0)) {
6012 				err = -EROFS;
6013 				goto restore_opts;
6014 			}
6015 			/*
6016 			 * Make sure the group descriptor checksums
6017 			 * are sane.  If they aren't, refuse to remount r/w.
6018 			 */
6019 			for (g = 0; g < sbi->s_groups_count; g++) {
6020 				struct ext4_group_desc *gdp =
6021 					ext4_get_group_desc(sb, g, NULL);
6022 
6023 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6024 					ext4_msg(sb, KERN_ERR,
6025 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6026 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6027 					       le16_to_cpu(gdp->bg_checksum));
6028 					err = -EFSBADCRC;
6029 					goto restore_opts;
6030 				}
6031 			}
6032 
6033 			/*
6034 			 * If we have an unprocessed orphan list hanging
6035 			 * around from a previously readonly bdev mount,
6036 			 * require a full umount/remount for now.
6037 			 */
6038 			if (es->s_last_orphan) {
6039 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6040 				       "remount RDWR because of unprocessed "
6041 				       "orphan inode list.  Please "
6042 				       "umount/remount instead");
6043 				err = -EINVAL;
6044 				goto restore_opts;
6045 			}
6046 
6047 			/*
6048 			 * Mounting a RDONLY partition read-write, so reread
6049 			 * and store the current valid flag.  (It may have
6050 			 * been changed by e2fsck since we originally mounted
6051 			 * the partition.)
6052 			 */
6053 			if (sbi->s_journal) {
6054 				err = ext4_clear_journal_err(sb, es);
6055 				if (err)
6056 					goto restore_opts;
6057 			}
6058 			sbi->s_mount_state = le16_to_cpu(es->s_state);
6059 
6060 			err = ext4_setup_super(sb, es, 0);
6061 			if (err)
6062 				goto restore_opts;
6063 
6064 			sb->s_flags &= ~SB_RDONLY;
6065 			if (ext4_has_feature_mmp(sb))
6066 				if (ext4_multi_mount_protect(sb,
6067 						le64_to_cpu(es->s_mmp_block))) {
6068 					err = -EROFS;
6069 					goto restore_opts;
6070 				}
6071 			enable_quota = 1;
6072 		}
6073 	}
6074 
6075 	/*
6076 	 * Reinitialize lazy itable initialization thread based on
6077 	 * current settings
6078 	 */
6079 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6080 		ext4_unregister_li_request(sb);
6081 	else {
6082 		ext4_group_t first_not_zeroed;
6083 		first_not_zeroed = ext4_has_uninit_itable(sb);
6084 		ext4_register_li_request(sb, first_not_zeroed);
6085 	}
6086 
6087 	/*
6088 	 * Handle creation of system zone data early because it can fail.
6089 	 * Releasing of existing data is done when we are sure remount will
6090 	 * succeed.
6091 	 */
6092 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6093 		err = ext4_setup_system_zone(sb);
6094 		if (err)
6095 			goto restore_opts;
6096 	}
6097 
6098 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6099 		err = ext4_commit_super(sb);
6100 		if (err)
6101 			goto restore_opts;
6102 	}
6103 
6104 #ifdef CONFIG_QUOTA
6105 	/* Release old quota file names */
6106 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6107 		kfree(old_opts.s_qf_names[i]);
6108 	if (enable_quota) {
6109 		if (sb_any_quota_suspended(sb))
6110 			dquot_resume(sb, -1);
6111 		else if (ext4_has_feature_quota(sb)) {
6112 			err = ext4_enable_quotas(sb);
6113 			if (err)
6114 				goto restore_opts;
6115 		}
6116 	}
6117 #endif
6118 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6119 		ext4_release_system_zone(sb);
6120 
6121 	/*
6122 	 * Some options can be enabled by ext4 and/or by VFS mount flag
6123 	 * either way we need to make sure it matches in both *flags and
6124 	 * s_flags. Copy those selected flags from s_flags to *flags
6125 	 */
6126 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6127 
6128 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s. Quota mode: %s.",
6129 		 orig_data, ext4_quota_mode(sb));
6130 	kfree(orig_data);
6131 	return 0;
6132 
6133 restore_opts:
6134 	sb->s_flags = old_sb_flags;
6135 	sbi->s_mount_opt = old_opts.s_mount_opt;
6136 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6137 	sbi->s_resuid = old_opts.s_resuid;
6138 	sbi->s_resgid = old_opts.s_resgid;
6139 	sbi->s_commit_interval = old_opts.s_commit_interval;
6140 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6141 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6142 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6143 		ext4_release_system_zone(sb);
6144 #ifdef CONFIG_QUOTA
6145 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6146 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6147 		to_free[i] = get_qf_name(sb, sbi, i);
6148 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6149 	}
6150 	synchronize_rcu();
6151 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6152 		kfree(to_free[i]);
6153 #endif
6154 	kfree(orig_data);
6155 	return err;
6156 }
6157 
6158 #ifdef CONFIG_QUOTA
6159 static int ext4_statfs_project(struct super_block *sb,
6160 			       kprojid_t projid, struct kstatfs *buf)
6161 {
6162 	struct kqid qid;
6163 	struct dquot *dquot;
6164 	u64 limit;
6165 	u64 curblock;
6166 
6167 	qid = make_kqid_projid(projid);
6168 	dquot = dqget(sb, qid);
6169 	if (IS_ERR(dquot))
6170 		return PTR_ERR(dquot);
6171 	spin_lock(&dquot->dq_dqb_lock);
6172 
6173 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6174 			     dquot->dq_dqb.dqb_bhardlimit);
6175 	limit >>= sb->s_blocksize_bits;
6176 
6177 	if (limit && buf->f_blocks > limit) {
6178 		curblock = (dquot->dq_dqb.dqb_curspace +
6179 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6180 		buf->f_blocks = limit;
6181 		buf->f_bfree = buf->f_bavail =
6182 			(buf->f_blocks > curblock) ?
6183 			 (buf->f_blocks - curblock) : 0;
6184 	}
6185 
6186 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6187 			     dquot->dq_dqb.dqb_ihardlimit);
6188 	if (limit && buf->f_files > limit) {
6189 		buf->f_files = limit;
6190 		buf->f_ffree =
6191 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6192 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6193 	}
6194 
6195 	spin_unlock(&dquot->dq_dqb_lock);
6196 	dqput(dquot);
6197 	return 0;
6198 }
6199 #endif
6200 
6201 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6202 {
6203 	struct super_block *sb = dentry->d_sb;
6204 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6205 	struct ext4_super_block *es = sbi->s_es;
6206 	ext4_fsblk_t overhead = 0, resv_blocks;
6207 	s64 bfree;
6208 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6209 
6210 	if (!test_opt(sb, MINIX_DF))
6211 		overhead = sbi->s_overhead;
6212 
6213 	buf->f_type = EXT4_SUPER_MAGIC;
6214 	buf->f_bsize = sb->s_blocksize;
6215 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6216 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6217 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6218 	/* prevent underflow in case that few free space is available */
6219 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6220 	buf->f_bavail = buf->f_bfree -
6221 			(ext4_r_blocks_count(es) + resv_blocks);
6222 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6223 		buf->f_bavail = 0;
6224 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6225 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6226 	buf->f_namelen = EXT4_NAME_LEN;
6227 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6228 
6229 #ifdef CONFIG_QUOTA
6230 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6231 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6232 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6233 #endif
6234 	return 0;
6235 }
6236 
6237 
6238 #ifdef CONFIG_QUOTA
6239 
6240 /*
6241  * Helper functions so that transaction is started before we acquire dqio_sem
6242  * to keep correct lock ordering of transaction > dqio_sem
6243  */
6244 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6245 {
6246 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6247 }
6248 
6249 static int ext4_write_dquot(struct dquot *dquot)
6250 {
6251 	int ret, err;
6252 	handle_t *handle;
6253 	struct inode *inode;
6254 
6255 	inode = dquot_to_inode(dquot);
6256 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6257 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6258 	if (IS_ERR(handle))
6259 		return PTR_ERR(handle);
6260 	ret = dquot_commit(dquot);
6261 	err = ext4_journal_stop(handle);
6262 	if (!ret)
6263 		ret = err;
6264 	return ret;
6265 }
6266 
6267 static int ext4_acquire_dquot(struct dquot *dquot)
6268 {
6269 	int ret, err;
6270 	handle_t *handle;
6271 
6272 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6273 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6274 	if (IS_ERR(handle))
6275 		return PTR_ERR(handle);
6276 	ret = dquot_acquire(dquot);
6277 	err = ext4_journal_stop(handle);
6278 	if (!ret)
6279 		ret = err;
6280 	return ret;
6281 }
6282 
6283 static int ext4_release_dquot(struct dquot *dquot)
6284 {
6285 	int ret, err;
6286 	handle_t *handle;
6287 
6288 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6289 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6290 	if (IS_ERR(handle)) {
6291 		/* Release dquot anyway to avoid endless cycle in dqput() */
6292 		dquot_release(dquot);
6293 		return PTR_ERR(handle);
6294 	}
6295 	ret = dquot_release(dquot);
6296 	err = ext4_journal_stop(handle);
6297 	if (!ret)
6298 		ret = err;
6299 	return ret;
6300 }
6301 
6302 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6303 {
6304 	struct super_block *sb = dquot->dq_sb;
6305 
6306 	if (ext4_is_quota_journalled(sb)) {
6307 		dquot_mark_dquot_dirty(dquot);
6308 		return ext4_write_dquot(dquot);
6309 	} else {
6310 		return dquot_mark_dquot_dirty(dquot);
6311 	}
6312 }
6313 
6314 static int ext4_write_info(struct super_block *sb, int type)
6315 {
6316 	int ret, err;
6317 	handle_t *handle;
6318 
6319 	/* Data block + inode block */
6320 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6321 	if (IS_ERR(handle))
6322 		return PTR_ERR(handle);
6323 	ret = dquot_commit_info(sb, type);
6324 	err = ext4_journal_stop(handle);
6325 	if (!ret)
6326 		ret = err;
6327 	return ret;
6328 }
6329 
6330 /*
6331  * Turn on quotas during mount time - we need to find
6332  * the quota file and such...
6333  */
6334 static int ext4_quota_on_mount(struct super_block *sb, int type)
6335 {
6336 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6337 					EXT4_SB(sb)->s_jquota_fmt, type);
6338 }
6339 
6340 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6341 {
6342 	struct ext4_inode_info *ei = EXT4_I(inode);
6343 
6344 	/* The first argument of lockdep_set_subclass has to be
6345 	 * *exactly* the same as the argument to init_rwsem() --- in
6346 	 * this case, in init_once() --- or lockdep gets unhappy
6347 	 * because the name of the lock is set using the
6348 	 * stringification of the argument to init_rwsem().
6349 	 */
6350 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6351 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6352 }
6353 
6354 /*
6355  * Standard function to be called on quota_on
6356  */
6357 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6358 			 const struct path *path)
6359 {
6360 	int err;
6361 
6362 	if (!test_opt(sb, QUOTA))
6363 		return -EINVAL;
6364 
6365 	/* Quotafile not on the same filesystem? */
6366 	if (path->dentry->d_sb != sb)
6367 		return -EXDEV;
6368 
6369 	/* Quota already enabled for this file? */
6370 	if (IS_NOQUOTA(d_inode(path->dentry)))
6371 		return -EBUSY;
6372 
6373 	/* Journaling quota? */
6374 	if (EXT4_SB(sb)->s_qf_names[type]) {
6375 		/* Quotafile not in fs root? */
6376 		if (path->dentry->d_parent != sb->s_root)
6377 			ext4_msg(sb, KERN_WARNING,
6378 				"Quota file not on filesystem root. "
6379 				"Journaled quota will not work");
6380 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6381 	} else {
6382 		/*
6383 		 * Clear the flag just in case mount options changed since
6384 		 * last time.
6385 		 */
6386 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6387 	}
6388 
6389 	/*
6390 	 * When we journal data on quota file, we have to flush journal to see
6391 	 * all updates to the file when we bypass pagecache...
6392 	 */
6393 	if (EXT4_SB(sb)->s_journal &&
6394 	    ext4_should_journal_data(d_inode(path->dentry))) {
6395 		/*
6396 		 * We don't need to lock updates but journal_flush() could
6397 		 * otherwise be livelocked...
6398 		 */
6399 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6400 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6401 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6402 		if (err)
6403 			return err;
6404 	}
6405 
6406 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6407 	err = dquot_quota_on(sb, type, format_id, path);
6408 	if (err) {
6409 		lockdep_set_quota_inode(path->dentry->d_inode,
6410 					     I_DATA_SEM_NORMAL);
6411 	} else {
6412 		struct inode *inode = d_inode(path->dentry);
6413 		handle_t *handle;
6414 
6415 		/*
6416 		 * Set inode flags to prevent userspace from messing with quota
6417 		 * files. If this fails, we return success anyway since quotas
6418 		 * are already enabled and this is not a hard failure.
6419 		 */
6420 		inode_lock(inode);
6421 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6422 		if (IS_ERR(handle))
6423 			goto unlock_inode;
6424 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6425 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6426 				S_NOATIME | S_IMMUTABLE);
6427 		err = ext4_mark_inode_dirty(handle, inode);
6428 		ext4_journal_stop(handle);
6429 	unlock_inode:
6430 		inode_unlock(inode);
6431 	}
6432 	return err;
6433 }
6434 
6435 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6436 			     unsigned int flags)
6437 {
6438 	int err;
6439 	struct inode *qf_inode;
6440 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6441 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6442 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6443 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6444 	};
6445 
6446 	BUG_ON(!ext4_has_feature_quota(sb));
6447 
6448 	if (!qf_inums[type])
6449 		return -EPERM;
6450 
6451 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6452 	if (IS_ERR(qf_inode)) {
6453 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6454 		return PTR_ERR(qf_inode);
6455 	}
6456 
6457 	/* Don't account quota for quota files to avoid recursion */
6458 	qf_inode->i_flags |= S_NOQUOTA;
6459 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6460 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6461 	if (err)
6462 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6463 	iput(qf_inode);
6464 
6465 	return err;
6466 }
6467 
6468 /* Enable usage tracking for all quota types. */
6469 static int ext4_enable_quotas(struct super_block *sb)
6470 {
6471 	int type, err = 0;
6472 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6473 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6474 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6475 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6476 	};
6477 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6478 		test_opt(sb, USRQUOTA),
6479 		test_opt(sb, GRPQUOTA),
6480 		test_opt(sb, PRJQUOTA),
6481 	};
6482 
6483 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6484 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6485 		if (qf_inums[type]) {
6486 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6487 				DQUOT_USAGE_ENABLED |
6488 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6489 			if (err) {
6490 				ext4_warning(sb,
6491 					"Failed to enable quota tracking "
6492 					"(type=%d, err=%d). Please run "
6493 					"e2fsck to fix.", type, err);
6494 				for (type--; type >= 0; type--)
6495 					dquot_quota_off(sb, type);
6496 
6497 				return err;
6498 			}
6499 		}
6500 	}
6501 	return 0;
6502 }
6503 
6504 static int ext4_quota_off(struct super_block *sb, int type)
6505 {
6506 	struct inode *inode = sb_dqopt(sb)->files[type];
6507 	handle_t *handle;
6508 	int err;
6509 
6510 	/* Force all delayed allocation blocks to be allocated.
6511 	 * Caller already holds s_umount sem */
6512 	if (test_opt(sb, DELALLOC))
6513 		sync_filesystem(sb);
6514 
6515 	if (!inode || !igrab(inode))
6516 		goto out;
6517 
6518 	err = dquot_quota_off(sb, type);
6519 	if (err || ext4_has_feature_quota(sb))
6520 		goto out_put;
6521 
6522 	inode_lock(inode);
6523 	/*
6524 	 * Update modification times of quota files when userspace can
6525 	 * start looking at them. If we fail, we return success anyway since
6526 	 * this is not a hard failure and quotas are already disabled.
6527 	 */
6528 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6529 	if (IS_ERR(handle)) {
6530 		err = PTR_ERR(handle);
6531 		goto out_unlock;
6532 	}
6533 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6534 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6535 	inode->i_mtime = inode->i_ctime = current_time(inode);
6536 	err = ext4_mark_inode_dirty(handle, inode);
6537 	ext4_journal_stop(handle);
6538 out_unlock:
6539 	inode_unlock(inode);
6540 out_put:
6541 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6542 	iput(inode);
6543 	return err;
6544 out:
6545 	return dquot_quota_off(sb, type);
6546 }
6547 
6548 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6549  * acquiring the locks... As quota files are never truncated and quota code
6550  * itself serializes the operations (and no one else should touch the files)
6551  * we don't have to be afraid of races */
6552 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6553 			       size_t len, loff_t off)
6554 {
6555 	struct inode *inode = sb_dqopt(sb)->files[type];
6556 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6557 	int offset = off & (sb->s_blocksize - 1);
6558 	int tocopy;
6559 	size_t toread;
6560 	struct buffer_head *bh;
6561 	loff_t i_size = i_size_read(inode);
6562 
6563 	if (off > i_size)
6564 		return 0;
6565 	if (off+len > i_size)
6566 		len = i_size-off;
6567 	toread = len;
6568 	while (toread > 0) {
6569 		tocopy = sb->s_blocksize - offset < toread ?
6570 				sb->s_blocksize - offset : toread;
6571 		bh = ext4_bread(NULL, inode, blk, 0);
6572 		if (IS_ERR(bh))
6573 			return PTR_ERR(bh);
6574 		if (!bh)	/* A hole? */
6575 			memset(data, 0, tocopy);
6576 		else
6577 			memcpy(data, bh->b_data+offset, tocopy);
6578 		brelse(bh);
6579 		offset = 0;
6580 		toread -= tocopy;
6581 		data += tocopy;
6582 		blk++;
6583 	}
6584 	return len;
6585 }
6586 
6587 /* Write to quotafile (we know the transaction is already started and has
6588  * enough credits) */
6589 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6590 				const char *data, size_t len, loff_t off)
6591 {
6592 	struct inode *inode = sb_dqopt(sb)->files[type];
6593 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6594 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6595 	int retries = 0;
6596 	struct buffer_head *bh;
6597 	handle_t *handle = journal_current_handle();
6598 
6599 	if (EXT4_SB(sb)->s_journal && !handle) {
6600 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6601 			" cancelled because transaction is not started",
6602 			(unsigned long long)off, (unsigned long long)len);
6603 		return -EIO;
6604 	}
6605 	/*
6606 	 * Since we account only one data block in transaction credits,
6607 	 * then it is impossible to cross a block boundary.
6608 	 */
6609 	if (sb->s_blocksize - offset < len) {
6610 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6611 			" cancelled because not block aligned",
6612 			(unsigned long long)off, (unsigned long long)len);
6613 		return -EIO;
6614 	}
6615 
6616 	do {
6617 		bh = ext4_bread(handle, inode, blk,
6618 				EXT4_GET_BLOCKS_CREATE |
6619 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6620 	} while (PTR_ERR(bh) == -ENOSPC &&
6621 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6622 	if (IS_ERR(bh))
6623 		return PTR_ERR(bh);
6624 	if (!bh)
6625 		goto out;
6626 	BUFFER_TRACE(bh, "get write access");
6627 	err = ext4_journal_get_write_access(handle, bh);
6628 	if (err) {
6629 		brelse(bh);
6630 		return err;
6631 	}
6632 	lock_buffer(bh);
6633 	memcpy(bh->b_data+offset, data, len);
6634 	flush_dcache_page(bh->b_page);
6635 	unlock_buffer(bh);
6636 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6637 	brelse(bh);
6638 out:
6639 	if (inode->i_size < off + len) {
6640 		i_size_write(inode, off + len);
6641 		EXT4_I(inode)->i_disksize = inode->i_size;
6642 		err2 = ext4_mark_inode_dirty(handle, inode);
6643 		if (unlikely(err2 && !err))
6644 			err = err2;
6645 	}
6646 	return err ? err : len;
6647 }
6648 #endif
6649 
6650 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6651 		       const char *dev_name, void *data)
6652 {
6653 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6654 }
6655 
6656 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6657 static inline void register_as_ext2(void)
6658 {
6659 	int err = register_filesystem(&ext2_fs_type);
6660 	if (err)
6661 		printk(KERN_WARNING
6662 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6663 }
6664 
6665 static inline void unregister_as_ext2(void)
6666 {
6667 	unregister_filesystem(&ext2_fs_type);
6668 }
6669 
6670 static inline int ext2_feature_set_ok(struct super_block *sb)
6671 {
6672 	if (ext4_has_unknown_ext2_incompat_features(sb))
6673 		return 0;
6674 	if (sb_rdonly(sb))
6675 		return 1;
6676 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6677 		return 0;
6678 	return 1;
6679 }
6680 #else
6681 static inline void register_as_ext2(void) { }
6682 static inline void unregister_as_ext2(void) { }
6683 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6684 #endif
6685 
6686 static inline void register_as_ext3(void)
6687 {
6688 	int err = register_filesystem(&ext3_fs_type);
6689 	if (err)
6690 		printk(KERN_WARNING
6691 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6692 }
6693 
6694 static inline void unregister_as_ext3(void)
6695 {
6696 	unregister_filesystem(&ext3_fs_type);
6697 }
6698 
6699 static inline int ext3_feature_set_ok(struct super_block *sb)
6700 {
6701 	if (ext4_has_unknown_ext3_incompat_features(sb))
6702 		return 0;
6703 	if (!ext4_has_feature_journal(sb))
6704 		return 0;
6705 	if (sb_rdonly(sb))
6706 		return 1;
6707 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6708 		return 0;
6709 	return 1;
6710 }
6711 
6712 static struct file_system_type ext4_fs_type = {
6713 	.owner		= THIS_MODULE,
6714 	.name		= "ext4",
6715 	.mount		= ext4_mount,
6716 	.kill_sb	= kill_block_super,
6717 	.fs_flags	= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
6718 };
6719 MODULE_ALIAS_FS("ext4");
6720 
6721 /* Shared across all ext4 file systems */
6722 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6723 
6724 static int __init ext4_init_fs(void)
6725 {
6726 	int i, err;
6727 
6728 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6729 	ext4_li_info = NULL;
6730 
6731 	/* Build-time check for flags consistency */
6732 	ext4_check_flag_values();
6733 
6734 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6735 		init_waitqueue_head(&ext4__ioend_wq[i]);
6736 
6737 	err = ext4_init_es();
6738 	if (err)
6739 		return err;
6740 
6741 	err = ext4_init_pending();
6742 	if (err)
6743 		goto out7;
6744 
6745 	err = ext4_init_post_read_processing();
6746 	if (err)
6747 		goto out6;
6748 
6749 	err = ext4_init_pageio();
6750 	if (err)
6751 		goto out5;
6752 
6753 	err = ext4_init_system_zone();
6754 	if (err)
6755 		goto out4;
6756 
6757 	err = ext4_init_sysfs();
6758 	if (err)
6759 		goto out3;
6760 
6761 	err = ext4_init_mballoc();
6762 	if (err)
6763 		goto out2;
6764 	err = init_inodecache();
6765 	if (err)
6766 		goto out1;
6767 
6768 	err = ext4_fc_init_dentry_cache();
6769 	if (err)
6770 		goto out05;
6771 
6772 	register_as_ext3();
6773 	register_as_ext2();
6774 	err = register_filesystem(&ext4_fs_type);
6775 	if (err)
6776 		goto out;
6777 
6778 	return 0;
6779 out:
6780 	unregister_as_ext2();
6781 	unregister_as_ext3();
6782 out05:
6783 	destroy_inodecache();
6784 out1:
6785 	ext4_exit_mballoc();
6786 out2:
6787 	ext4_exit_sysfs();
6788 out3:
6789 	ext4_exit_system_zone();
6790 out4:
6791 	ext4_exit_pageio();
6792 out5:
6793 	ext4_exit_post_read_processing();
6794 out6:
6795 	ext4_exit_pending();
6796 out7:
6797 	ext4_exit_es();
6798 
6799 	return err;
6800 }
6801 
6802 static void __exit ext4_exit_fs(void)
6803 {
6804 	ext4_destroy_lazyinit_thread();
6805 	unregister_as_ext2();
6806 	unregister_as_ext3();
6807 	unregister_filesystem(&ext4_fs_type);
6808 	destroy_inodecache();
6809 	ext4_exit_mballoc();
6810 	ext4_exit_sysfs();
6811 	ext4_exit_system_zone();
6812 	ext4_exit_pageio();
6813 	ext4_exit_post_read_processing();
6814 	ext4_exit_es();
6815 	ext4_exit_pending();
6816 }
6817 
6818 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6819 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6820 MODULE_LICENSE("GPL");
6821 MODULE_SOFTDEP("pre: crc32c");
6822 module_init(ext4_init_fs)
6823 module_exit(ext4_exit_fs)
6824