xref: /linux/fs/ext4/super.c (revision e7cd4b811c9e019f5acbce85699c622b30194c24)
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/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static void ext4_kill_sb(struct super_block *sb);
97 static const struct fs_parameter_spec ext4_param_specs[];
98 
99 /*
100  * Lock ordering
101  *
102  * page fault path:
103  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
104  *   -> page lock -> i_data_sem (rw)
105  *
106  * buffered write path:
107  * sb_start_write -> i_mutex -> mmap_lock
108  * sb_start_write -> i_mutex -> transaction start -> page lock ->
109  *   i_data_sem (rw)
110  *
111  * truncate:
112  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
113  *   page lock
114  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
115  *   i_data_sem (rw)
116  *
117  * direct IO:
118  * sb_start_write -> i_mutex -> mmap_lock
119  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
120  *
121  * writepages:
122  * transaction start -> page lock(s) -> i_data_sem (rw)
123  */
124 
125 static const struct fs_context_operations ext4_context_ops = {
126 	.parse_param	= ext4_parse_param,
127 	.get_tree	= ext4_get_tree,
128 	.reconfigure	= ext4_reconfigure,
129 	.free		= ext4_fc_free,
130 };
131 
132 
133 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
134 static struct file_system_type ext2_fs_type = {
135 	.owner			= THIS_MODULE,
136 	.name			= "ext2",
137 	.init_fs_context	= ext4_init_fs_context,
138 	.parameters		= ext4_param_specs,
139 	.kill_sb		= ext4_kill_sb,
140 	.fs_flags		= FS_REQUIRES_DEV,
141 };
142 MODULE_ALIAS_FS("ext2");
143 MODULE_ALIAS("ext2");
144 #define IS_EXT2_SB(sb) ((sb)->s_type == &ext2_fs_type)
145 #else
146 #define IS_EXT2_SB(sb) (0)
147 #endif
148 
149 
150 static struct file_system_type ext3_fs_type = {
151 	.owner			= THIS_MODULE,
152 	.name			= "ext3",
153 	.init_fs_context	= ext4_init_fs_context,
154 	.parameters		= ext4_param_specs,
155 	.kill_sb		= ext4_kill_sb,
156 	.fs_flags		= FS_REQUIRES_DEV,
157 };
158 MODULE_ALIAS_FS("ext3");
159 MODULE_ALIAS("ext3");
160 #define IS_EXT3_SB(sb) ((sb)->s_type == &ext3_fs_type)
161 
162 
163 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
164 				  bh_end_io_t *end_io)
165 {
166 	/*
167 	 * buffer's verified bit is no longer valid after reading from
168 	 * disk again due to write out error, clear it to make sure we
169 	 * recheck the buffer contents.
170 	 */
171 	clear_buffer_verified(bh);
172 
173 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
174 	get_bh(bh);
175 	submit_bh(REQ_OP_READ | op_flags, bh);
176 }
177 
178 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
179 			 bh_end_io_t *end_io)
180 {
181 	BUG_ON(!buffer_locked(bh));
182 
183 	if (ext4_buffer_uptodate(bh)) {
184 		unlock_buffer(bh);
185 		return;
186 	}
187 	__ext4_read_bh(bh, op_flags, end_io);
188 }
189 
190 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
191 {
192 	BUG_ON(!buffer_locked(bh));
193 
194 	if (ext4_buffer_uptodate(bh)) {
195 		unlock_buffer(bh);
196 		return 0;
197 	}
198 
199 	__ext4_read_bh(bh, op_flags, end_io);
200 
201 	wait_on_buffer(bh);
202 	if (buffer_uptodate(bh))
203 		return 0;
204 	return -EIO;
205 }
206 
207 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
208 {
209 	lock_buffer(bh);
210 	if (!wait) {
211 		ext4_read_bh_nowait(bh, op_flags, NULL);
212 		return 0;
213 	}
214 	return ext4_read_bh(bh, op_flags, NULL);
215 }
216 
217 /*
218  * This works like __bread_gfp() except it uses ERR_PTR for error
219  * returns.  Currently with sb_bread it's impossible to distinguish
220  * between ENOMEM and EIO situations (since both result in a NULL
221  * return.
222  */
223 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
224 					       sector_t block,
225 					       blk_opf_t op_flags, gfp_t gfp)
226 {
227 	struct buffer_head *bh;
228 	int ret;
229 
230 	bh = sb_getblk_gfp(sb, block, gfp);
231 	if (bh == NULL)
232 		return ERR_PTR(-ENOMEM);
233 	if (ext4_buffer_uptodate(bh))
234 		return bh;
235 
236 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
237 	if (ret) {
238 		put_bh(bh);
239 		return ERR_PTR(ret);
240 	}
241 	return bh;
242 }
243 
244 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
245 				   blk_opf_t op_flags)
246 {
247 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
248 			~__GFP_FS) | __GFP_MOVABLE;
249 
250 	return __ext4_sb_bread_gfp(sb, block, op_flags, gfp);
251 }
252 
253 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
254 					    sector_t block)
255 {
256 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
257 			~__GFP_FS);
258 
259 	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
260 }
261 
262 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
263 {
264 	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
265 			sb->s_blocksize, GFP_NOWAIT | __GFP_NOWARN);
266 
267 	if (likely(bh)) {
268 		if (trylock_buffer(bh))
269 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
270 		brelse(bh);
271 	}
272 }
273 
274 static int ext4_verify_csum_type(struct super_block *sb,
275 				 struct ext4_super_block *es)
276 {
277 	if (!ext4_has_feature_metadata_csum(sb))
278 		return 1;
279 
280 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
281 }
282 
283 __le32 ext4_superblock_csum(struct super_block *sb,
284 			    struct ext4_super_block *es)
285 {
286 	struct ext4_sb_info *sbi = EXT4_SB(sb);
287 	int offset = offsetof(struct ext4_super_block, s_checksum);
288 	__u32 csum;
289 
290 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
291 
292 	return cpu_to_le32(csum);
293 }
294 
295 static int ext4_superblock_csum_verify(struct super_block *sb,
296 				       struct ext4_super_block *es)
297 {
298 	if (!ext4_has_metadata_csum(sb))
299 		return 1;
300 
301 	return es->s_checksum == ext4_superblock_csum(sb, es);
302 }
303 
304 void ext4_superblock_csum_set(struct super_block *sb)
305 {
306 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
307 
308 	if (!ext4_has_metadata_csum(sb))
309 		return;
310 
311 	es->s_checksum = ext4_superblock_csum(sb, es);
312 }
313 
314 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
323 			       struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
328 }
329 
330 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
331 			      struct ext4_group_desc *bg)
332 {
333 	return le32_to_cpu(bg->bg_inode_table_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
336 }
337 
338 __u32 ext4_free_group_clusters(struct super_block *sb,
339 			       struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_free_inodes_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
352 }
353 
354 __u32 ext4_used_dirs_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
360 }
361 
362 __u32 ext4_itable_unused_count(struct super_block *sb,
363 			      struct ext4_group_desc *bg)
364 {
365 	return le16_to_cpu(bg->bg_itable_unused_lo) |
366 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
367 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
368 }
369 
370 void ext4_block_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_bitmap_set(struct super_block *sb,
379 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_inode_table_set(struct super_block *sb,
387 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
388 {
389 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
392 }
393 
394 void ext4_free_group_clusters_set(struct super_block *sb,
395 				  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_free_inodes_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
408 }
409 
410 void ext4_used_dirs_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
416 }
417 
418 void ext4_itable_unused_set(struct super_block *sb,
419 			  struct ext4_group_desc *bg, __u32 count)
420 {
421 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
422 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
423 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
424 }
425 
426 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
427 {
428 	now = clamp_val(now, 0, (1ull << 40) - 1);
429 
430 	*lo = cpu_to_le32(lower_32_bits(now));
431 	*hi = upper_32_bits(now);
432 }
433 
434 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
435 {
436 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
437 }
438 #define ext4_update_tstamp(es, tstamp) \
439 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
440 			     ktime_get_real_seconds())
441 #define ext4_get_tstamp(es, tstamp) \
442 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
443 
444 #define EXT4_SB_REFRESH_INTERVAL_SEC (3600) /* seconds (1 hour) */
445 #define EXT4_SB_REFRESH_INTERVAL_KB (16384) /* kilobytes (16MB) */
446 
447 /*
448  * The ext4_maybe_update_superblock() function checks and updates the
449  * superblock if needed.
450  *
451  * This function is designed to update the on-disk superblock only under
452  * certain conditions to prevent excessive disk writes and unnecessary
453  * waking of the disk from sleep. The superblock will be updated if:
454  * 1. More than an hour has passed since the last superblock update, and
455  * 2. More than 16MB have been written since the last superblock update.
456  *
457  * @sb: The superblock
458  */
459 static void ext4_maybe_update_superblock(struct super_block *sb)
460 {
461 	struct ext4_sb_info *sbi = EXT4_SB(sb);
462 	struct ext4_super_block *es = sbi->s_es;
463 	journal_t *journal = sbi->s_journal;
464 	time64_t now;
465 	__u64 last_update;
466 	__u64 lifetime_write_kbytes;
467 	__u64 diff_size;
468 
469 	if (sb_rdonly(sb) || !(sb->s_flags & SB_ACTIVE) ||
470 	    !journal || (journal->j_flags & JBD2_UNMOUNT))
471 		return;
472 
473 	now = ktime_get_real_seconds();
474 	last_update = ext4_get_tstamp(es, s_wtime);
475 
476 	if (likely(now - last_update < EXT4_SB_REFRESH_INTERVAL_SEC))
477 		return;
478 
479 	lifetime_write_kbytes = sbi->s_kbytes_written +
480 		((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
481 		  sbi->s_sectors_written_start) >> 1);
482 
483 	/* Get the number of kilobytes not written to disk to account
484 	 * for statistics and compare with a multiple of 16 MB. This
485 	 * is used to determine when the next superblock commit should
486 	 * occur (i.e. not more often than once per 16MB if there was
487 	 * less written in an hour).
488 	 */
489 	diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written);
490 
491 	if (diff_size > EXT4_SB_REFRESH_INTERVAL_KB)
492 		schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
493 }
494 
495 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
496 {
497 	struct super_block		*sb = journal->j_private;
498 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
499 	int				error = is_journal_aborted(journal);
500 	struct ext4_journal_cb_entry	*jce;
501 
502 	BUG_ON(txn->t_state == T_FINISHED);
503 
504 	ext4_process_freed_data(sb, txn->t_tid);
505 	ext4_maybe_update_superblock(sb);
506 
507 	spin_lock(&sbi->s_md_lock);
508 	while (!list_empty(&txn->t_private_list)) {
509 		jce = list_entry(txn->t_private_list.next,
510 				 struct ext4_journal_cb_entry, jce_list);
511 		list_del_init(&jce->jce_list);
512 		spin_unlock(&sbi->s_md_lock);
513 		jce->jce_func(sb, jce, error);
514 		spin_lock(&sbi->s_md_lock);
515 	}
516 	spin_unlock(&sbi->s_md_lock);
517 }
518 
519 /*
520  * This writepage callback for write_cache_pages()
521  * takes care of a few cases after page cleaning.
522  *
523  * write_cache_pages() already checks for dirty pages
524  * and calls clear_page_dirty_for_io(), which we want,
525  * to write protect the pages.
526  *
527  * However, we may have to redirty a page (see below.)
528  */
529 static int ext4_journalled_writepage_callback(struct folio *folio,
530 					      struct writeback_control *wbc,
531 					      void *data)
532 {
533 	transaction_t *transaction = (transaction_t *) data;
534 	struct buffer_head *bh, *head;
535 	struct journal_head *jh;
536 
537 	bh = head = folio_buffers(folio);
538 	do {
539 		/*
540 		 * We have to redirty a page in these cases:
541 		 * 1) If buffer is dirty, it means the page was dirty because it
542 		 * contains a buffer that needs checkpointing. So the dirty bit
543 		 * needs to be preserved so that checkpointing writes the buffer
544 		 * properly.
545 		 * 2) If buffer is not part of the committing transaction
546 		 * (we may have just accidentally come across this buffer because
547 		 * inode range tracking is not exact) or if the currently running
548 		 * transaction already contains this buffer as well, dirty bit
549 		 * needs to be preserved so that the buffer gets writeprotected
550 		 * properly on running transaction's commit.
551 		 */
552 		jh = bh2jh(bh);
553 		if (buffer_dirty(bh) ||
554 		    (jh && (jh->b_transaction != transaction ||
555 			    jh->b_next_transaction))) {
556 			folio_redirty_for_writepage(wbc, folio);
557 			goto out;
558 		}
559 	} while ((bh = bh->b_this_page) != head);
560 
561 out:
562 	return AOP_WRITEPAGE_ACTIVATE;
563 }
564 
565 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
566 {
567 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
568 	struct writeback_control wbc = {
569 		.sync_mode =  WB_SYNC_ALL,
570 		.nr_to_write = LONG_MAX,
571 		.range_start = jinode->i_dirty_start,
572 		.range_end = jinode->i_dirty_end,
573         };
574 
575 	return write_cache_pages(mapping, &wbc,
576 				 ext4_journalled_writepage_callback,
577 				 jinode->i_transaction);
578 }
579 
580 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
581 {
582 	int ret;
583 
584 	if (ext4_should_journal_data(jinode->i_vfs_inode))
585 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
586 	else
587 		ret = ext4_normal_submit_inode_data_buffers(jinode);
588 	return ret;
589 }
590 
591 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
592 {
593 	int ret = 0;
594 
595 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
596 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
597 
598 	return ret;
599 }
600 
601 static bool system_going_down(void)
602 {
603 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
604 		|| system_state == SYSTEM_RESTART;
605 }
606 
607 struct ext4_err_translation {
608 	int code;
609 	int errno;
610 };
611 
612 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
613 
614 static struct ext4_err_translation err_translation[] = {
615 	EXT4_ERR_TRANSLATE(EIO),
616 	EXT4_ERR_TRANSLATE(ENOMEM),
617 	EXT4_ERR_TRANSLATE(EFSBADCRC),
618 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
619 	EXT4_ERR_TRANSLATE(ENOSPC),
620 	EXT4_ERR_TRANSLATE(ENOKEY),
621 	EXT4_ERR_TRANSLATE(EROFS),
622 	EXT4_ERR_TRANSLATE(EFBIG),
623 	EXT4_ERR_TRANSLATE(EEXIST),
624 	EXT4_ERR_TRANSLATE(ERANGE),
625 	EXT4_ERR_TRANSLATE(EOVERFLOW),
626 	EXT4_ERR_TRANSLATE(EBUSY),
627 	EXT4_ERR_TRANSLATE(ENOTDIR),
628 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
629 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
630 	EXT4_ERR_TRANSLATE(EFAULT),
631 };
632 
633 static int ext4_errno_to_code(int errno)
634 {
635 	int i;
636 
637 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
638 		if (err_translation[i].errno == errno)
639 			return err_translation[i].code;
640 	return EXT4_ERR_UNKNOWN;
641 }
642 
643 static void save_error_info(struct super_block *sb, int error,
644 			    __u32 ino, __u64 block,
645 			    const char *func, unsigned int line)
646 {
647 	struct ext4_sb_info *sbi = EXT4_SB(sb);
648 
649 	/* We default to EFSCORRUPTED error... */
650 	if (error == 0)
651 		error = EFSCORRUPTED;
652 
653 	spin_lock(&sbi->s_error_lock);
654 	sbi->s_add_error_count++;
655 	sbi->s_last_error_code = error;
656 	sbi->s_last_error_line = line;
657 	sbi->s_last_error_ino = ino;
658 	sbi->s_last_error_block = block;
659 	sbi->s_last_error_func = func;
660 	sbi->s_last_error_time = ktime_get_real_seconds();
661 	if (!sbi->s_first_error_time) {
662 		sbi->s_first_error_code = error;
663 		sbi->s_first_error_line = line;
664 		sbi->s_first_error_ino = ino;
665 		sbi->s_first_error_block = block;
666 		sbi->s_first_error_func = func;
667 		sbi->s_first_error_time = sbi->s_last_error_time;
668 	}
669 	spin_unlock(&sbi->s_error_lock);
670 }
671 
672 /* Deal with the reporting of failure conditions on a filesystem such as
673  * inconsistencies detected or read IO failures.
674  *
675  * On ext2, we can store the error state of the filesystem in the
676  * superblock.  That is not possible on ext4, because we may have other
677  * write ordering constraints on the superblock which prevent us from
678  * writing it out straight away; and given that the journal is about to
679  * be aborted, we can't rely on the current, or future, transactions to
680  * write out the superblock safely.
681  *
682  * We'll just use the jbd2_journal_abort() error code to record an error in
683  * the journal instead.  On recovery, the journal will complain about
684  * that error until we've noted it down and cleared it.
685  *
686  * If force_ro is set, we unconditionally force the filesystem into an
687  * ABORT|READONLY state, unless the error response on the fs has been set to
688  * panic in which case we take the easy way out and panic immediately. This is
689  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
690  * at a critical moment in log management.
691  */
692 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
693 			      __u32 ino, __u64 block,
694 			      const char *func, unsigned int line)
695 {
696 	journal_t *journal = EXT4_SB(sb)->s_journal;
697 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
698 
699 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
700 	if (test_opt(sb, WARN_ON_ERROR))
701 		WARN_ON_ONCE(1);
702 
703 	if (!continue_fs && !sb_rdonly(sb)) {
704 		set_bit(EXT4_FLAGS_SHUTDOWN, &EXT4_SB(sb)->s_ext4_flags);
705 		if (journal)
706 			jbd2_journal_abort(journal, -EIO);
707 	}
708 
709 	if (!bdev_read_only(sb->s_bdev)) {
710 		save_error_info(sb, error, ino, block, func, line);
711 		/*
712 		 * In case the fs should keep running, we need to writeout
713 		 * superblock through the journal. Due to lock ordering
714 		 * constraints, it may not be safe to do it right here so we
715 		 * defer superblock flushing to a workqueue.
716 		 */
717 		if (continue_fs && journal)
718 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
719 		else
720 			ext4_commit_super(sb);
721 	}
722 
723 	/*
724 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
725 	 * could panic during 'reboot -f' as the underlying device got already
726 	 * disabled.
727 	 */
728 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
729 		panic("EXT4-fs (device %s): panic forced after error\n",
730 			sb->s_id);
731 	}
732 
733 	if (sb_rdonly(sb) || continue_fs)
734 		return;
735 
736 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
737 	/*
738 	 * EXT4_FLAGS_SHUTDOWN was set which stops all filesystem
739 	 * modifications. We don't set SB_RDONLY because that requires
740 	 * sb->s_umount semaphore and setting it without proper remount
741 	 * procedure is confusing code such as freeze_super() leading to
742 	 * deadlocks and other problems.
743 	 */
744 }
745 
746 static void update_super_work(struct work_struct *work)
747 {
748 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
749 						s_sb_upd_work);
750 	journal_t *journal = sbi->s_journal;
751 	handle_t *handle;
752 
753 	/*
754 	 * If the journal is still running, we have to write out superblock
755 	 * through the journal to avoid collisions of other journalled sb
756 	 * updates.
757 	 *
758 	 * We use directly jbd2 functions here to avoid recursing back into
759 	 * ext4 error handling code during handling of previous errors.
760 	 */
761 	if (!sb_rdonly(sbi->s_sb) && journal) {
762 		struct buffer_head *sbh = sbi->s_sbh;
763 		bool call_notify_err = false;
764 
765 		handle = jbd2_journal_start(journal, 1);
766 		if (IS_ERR(handle))
767 			goto write_directly;
768 		if (jbd2_journal_get_write_access(handle, sbh)) {
769 			jbd2_journal_stop(handle);
770 			goto write_directly;
771 		}
772 
773 		if (sbi->s_add_error_count > 0)
774 			call_notify_err = true;
775 
776 		ext4_update_super(sbi->s_sb);
777 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
778 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
779 				 "superblock detected");
780 			clear_buffer_write_io_error(sbh);
781 			set_buffer_uptodate(sbh);
782 		}
783 
784 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
785 			jbd2_journal_stop(handle);
786 			goto write_directly;
787 		}
788 		jbd2_journal_stop(handle);
789 
790 		if (call_notify_err)
791 			ext4_notify_error_sysfs(sbi);
792 
793 		return;
794 	}
795 write_directly:
796 	/*
797 	 * Write through journal failed. Write sb directly to get error info
798 	 * out and hope for the best.
799 	 */
800 	ext4_commit_super(sbi->s_sb);
801 	ext4_notify_error_sysfs(sbi);
802 }
803 
804 #define ext4_error_ratelimit(sb)					\
805 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
806 			     "EXT4-fs error")
807 
808 void __ext4_error(struct super_block *sb, const char *function,
809 		  unsigned int line, bool force_ro, int error, __u64 block,
810 		  const char *fmt, ...)
811 {
812 	struct va_format vaf;
813 	va_list args;
814 
815 	if (unlikely(ext4_forced_shutdown(sb)))
816 		return;
817 
818 	trace_ext4_error(sb, function, line);
819 	if (ext4_error_ratelimit(sb)) {
820 		va_start(args, fmt);
821 		vaf.fmt = fmt;
822 		vaf.va = &args;
823 		printk(KERN_CRIT
824 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
825 		       sb->s_id, function, line, current->comm, &vaf);
826 		va_end(args);
827 	}
828 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
829 
830 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
831 }
832 
833 void __ext4_error_inode(struct inode *inode, const char *function,
834 			unsigned int line, ext4_fsblk_t block, int error,
835 			const char *fmt, ...)
836 {
837 	va_list args;
838 	struct va_format vaf;
839 
840 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
841 		return;
842 
843 	trace_ext4_error(inode->i_sb, function, line);
844 	if (ext4_error_ratelimit(inode->i_sb)) {
845 		va_start(args, fmt);
846 		vaf.fmt = fmt;
847 		vaf.va = &args;
848 		if (block)
849 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
850 			       "inode #%lu: block %llu: comm %s: %pV\n",
851 			       inode->i_sb->s_id, function, line, inode->i_ino,
852 			       block, current->comm, &vaf);
853 		else
854 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
855 			       "inode #%lu: comm %s: %pV\n",
856 			       inode->i_sb->s_id, function, line, inode->i_ino,
857 			       current->comm, &vaf);
858 		va_end(args);
859 	}
860 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
861 
862 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
863 			  function, line);
864 }
865 
866 void __ext4_error_file(struct file *file, const char *function,
867 		       unsigned int line, ext4_fsblk_t block,
868 		       const char *fmt, ...)
869 {
870 	va_list args;
871 	struct va_format vaf;
872 	struct inode *inode = file_inode(file);
873 	char pathname[80], *path;
874 
875 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
876 		return;
877 
878 	trace_ext4_error(inode->i_sb, function, line);
879 	if (ext4_error_ratelimit(inode->i_sb)) {
880 		path = file_path(file, pathname, sizeof(pathname));
881 		if (IS_ERR(path))
882 			path = "(unknown)";
883 		va_start(args, fmt);
884 		vaf.fmt = fmt;
885 		vaf.va = &args;
886 		if (block)
887 			printk(KERN_CRIT
888 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
889 			       "block %llu: comm %s: path %s: %pV\n",
890 			       inode->i_sb->s_id, function, line, inode->i_ino,
891 			       block, current->comm, path, &vaf);
892 		else
893 			printk(KERN_CRIT
894 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
895 			       "comm %s: path %s: %pV\n",
896 			       inode->i_sb->s_id, function, line, inode->i_ino,
897 			       current->comm, path, &vaf);
898 		va_end(args);
899 	}
900 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
901 
902 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
903 			  function, line);
904 }
905 
906 const char *ext4_decode_error(struct super_block *sb, int errno,
907 			      char nbuf[16])
908 {
909 	char *errstr = NULL;
910 
911 	switch (errno) {
912 	case -EFSCORRUPTED:
913 		errstr = "Corrupt filesystem";
914 		break;
915 	case -EFSBADCRC:
916 		errstr = "Filesystem failed CRC";
917 		break;
918 	case -EIO:
919 		errstr = "IO failure";
920 		break;
921 	case -ENOMEM:
922 		errstr = "Out of memory";
923 		break;
924 	case -EROFS:
925 		if (!sb || (EXT4_SB(sb)->s_journal &&
926 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
927 			errstr = "Journal has aborted";
928 		else
929 			errstr = "Readonly filesystem";
930 		break;
931 	default:
932 		/* If the caller passed in an extra buffer for unknown
933 		 * errors, textualise them now.  Else we just return
934 		 * NULL. */
935 		if (nbuf) {
936 			/* Check for truncated error codes... */
937 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
938 				errstr = nbuf;
939 		}
940 		break;
941 	}
942 
943 	return errstr;
944 }
945 
946 /* __ext4_std_error decodes expected errors from journaling functions
947  * automatically and invokes the appropriate error response.  */
948 
949 void __ext4_std_error(struct super_block *sb, const char *function,
950 		      unsigned int line, int errno)
951 {
952 	char nbuf[16];
953 	const char *errstr;
954 
955 	if (unlikely(ext4_forced_shutdown(sb)))
956 		return;
957 
958 	/* Special case: if the error is EROFS, and we're not already
959 	 * inside a transaction, then there's really no point in logging
960 	 * an error. */
961 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
962 		return;
963 
964 	if (ext4_error_ratelimit(sb)) {
965 		errstr = ext4_decode_error(sb, errno, nbuf);
966 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
967 		       sb->s_id, function, line, errstr);
968 	}
969 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
970 
971 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
972 }
973 
974 void __ext4_msg(struct super_block *sb,
975 		const char *prefix, const char *fmt, ...)
976 {
977 	struct va_format vaf;
978 	va_list args;
979 
980 	if (sb) {
981 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
982 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
983 				  "EXT4-fs"))
984 			return;
985 	}
986 
987 	va_start(args, fmt);
988 	vaf.fmt = fmt;
989 	vaf.va = &args;
990 	if (sb)
991 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
992 	else
993 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
994 	va_end(args);
995 }
996 
997 static int ext4_warning_ratelimit(struct super_block *sb)
998 {
999 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
1000 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1001 			    "EXT4-fs warning");
1002 }
1003 
1004 void __ext4_warning(struct super_block *sb, const char *function,
1005 		    unsigned int line, const char *fmt, ...)
1006 {
1007 	struct va_format vaf;
1008 	va_list args;
1009 
1010 	if (!ext4_warning_ratelimit(sb))
1011 		return;
1012 
1013 	va_start(args, fmt);
1014 	vaf.fmt = fmt;
1015 	vaf.va = &args;
1016 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1017 	       sb->s_id, function, line, &vaf);
1018 	va_end(args);
1019 }
1020 
1021 void __ext4_warning_inode(const struct inode *inode, const char *function,
1022 			  unsigned int line, const char *fmt, ...)
1023 {
1024 	struct va_format vaf;
1025 	va_list args;
1026 
1027 	if (!ext4_warning_ratelimit(inode->i_sb))
1028 		return;
1029 
1030 	va_start(args, fmt);
1031 	vaf.fmt = fmt;
1032 	vaf.va = &args;
1033 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1034 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
1035 	       function, line, inode->i_ino, current->comm, &vaf);
1036 	va_end(args);
1037 }
1038 
1039 void __ext4_grp_locked_error(const char *function, unsigned int line,
1040 			     struct super_block *sb, ext4_group_t grp,
1041 			     unsigned long ino, ext4_fsblk_t block,
1042 			     const char *fmt, ...)
1043 __releases(bitlock)
1044 __acquires(bitlock)
1045 {
1046 	struct va_format vaf;
1047 	va_list args;
1048 
1049 	if (unlikely(ext4_forced_shutdown(sb)))
1050 		return;
1051 
1052 	trace_ext4_error(sb, function, line);
1053 	if (ext4_error_ratelimit(sb)) {
1054 		va_start(args, fmt);
1055 		vaf.fmt = fmt;
1056 		vaf.va = &args;
1057 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1058 		       sb->s_id, function, line, grp);
1059 		if (ino)
1060 			printk(KERN_CONT "inode %lu: ", ino);
1061 		if (block)
1062 			printk(KERN_CONT "block %llu:",
1063 			       (unsigned long long) block);
1064 		printk(KERN_CONT "%pV\n", &vaf);
1065 		va_end(args);
1066 	}
1067 
1068 	if (test_opt(sb, ERRORS_CONT)) {
1069 		if (test_opt(sb, WARN_ON_ERROR))
1070 			WARN_ON_ONCE(1);
1071 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1072 		if (!bdev_read_only(sb->s_bdev)) {
1073 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1074 					line);
1075 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1076 		}
1077 		return;
1078 	}
1079 	ext4_unlock_group(sb, grp);
1080 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1081 	/*
1082 	 * We only get here in the ERRORS_RO case; relocking the group
1083 	 * may be dangerous, but nothing bad will happen since the
1084 	 * filesystem will have already been marked read/only and the
1085 	 * journal has been aborted.  We return 1 as a hint to callers
1086 	 * who might what to use the return value from
1087 	 * ext4_grp_locked_error() to distinguish between the
1088 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1089 	 * aggressively from the ext4 function in question, with a
1090 	 * more appropriate error code.
1091 	 */
1092 	ext4_lock_group(sb, grp);
1093 	return;
1094 }
1095 
1096 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1097 				     ext4_group_t group,
1098 				     unsigned int flags)
1099 {
1100 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1101 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1102 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1103 	int ret;
1104 
1105 	if (!grp || !gdp)
1106 		return;
1107 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1108 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1109 					    &grp->bb_state);
1110 		if (!ret)
1111 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1112 					   grp->bb_free);
1113 	}
1114 
1115 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1116 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1117 					    &grp->bb_state);
1118 		if (!ret && gdp) {
1119 			int count;
1120 
1121 			count = ext4_free_inodes_count(sb, gdp);
1122 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1123 					   count);
1124 		}
1125 	}
1126 }
1127 
1128 void ext4_update_dynamic_rev(struct super_block *sb)
1129 {
1130 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1131 
1132 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1133 		return;
1134 
1135 	ext4_warning(sb,
1136 		     "updating to rev %d because of new feature flag, "
1137 		     "running e2fsck is recommended",
1138 		     EXT4_DYNAMIC_REV);
1139 
1140 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1141 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1142 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1143 	/* leave es->s_feature_*compat flags alone */
1144 	/* es->s_uuid will be set by e2fsck if empty */
1145 
1146 	/*
1147 	 * The rest of the superblock fields should be zero, and if not it
1148 	 * means they are likely already in use, so leave them alone.  We
1149 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1150 	 */
1151 }
1152 
1153 static inline struct inode *orphan_list_entry(struct list_head *l)
1154 {
1155 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1156 }
1157 
1158 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1159 {
1160 	struct list_head *l;
1161 
1162 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1163 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1164 
1165 	printk(KERN_ERR "sb_info orphan list:\n");
1166 	list_for_each(l, &sbi->s_orphan) {
1167 		struct inode *inode = orphan_list_entry(l);
1168 		printk(KERN_ERR "  "
1169 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1170 		       inode->i_sb->s_id, inode->i_ino, inode,
1171 		       inode->i_mode, inode->i_nlink,
1172 		       NEXT_ORPHAN(inode));
1173 	}
1174 }
1175 
1176 #ifdef CONFIG_QUOTA
1177 static int ext4_quota_off(struct super_block *sb, int type);
1178 
1179 static inline void ext4_quotas_off(struct super_block *sb, int type)
1180 {
1181 	BUG_ON(type > EXT4_MAXQUOTAS);
1182 
1183 	/* Use our quota_off function to clear inode flags etc. */
1184 	for (type--; type >= 0; type--)
1185 		ext4_quota_off(sb, type);
1186 }
1187 
1188 /*
1189  * This is a helper function which is used in the mount/remount
1190  * codepaths (which holds s_umount) to fetch the quota file name.
1191  */
1192 static inline char *get_qf_name(struct super_block *sb,
1193 				struct ext4_sb_info *sbi,
1194 				int type)
1195 {
1196 	return rcu_dereference_protected(sbi->s_qf_names[type],
1197 					 lockdep_is_held(&sb->s_umount));
1198 }
1199 #else
1200 static inline void ext4_quotas_off(struct super_block *sb, int type)
1201 {
1202 }
1203 #endif
1204 
1205 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1206 {
1207 	ext4_fsblk_t block;
1208 	int err;
1209 
1210 	block = ext4_count_free_clusters(sbi->s_sb);
1211 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1212 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1213 				  GFP_KERNEL);
1214 	if (!err) {
1215 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1216 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1217 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1218 					  GFP_KERNEL);
1219 	}
1220 	if (!err)
1221 		err = percpu_counter_init(&sbi->s_dirs_counter,
1222 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1223 	if (!err)
1224 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1225 					  GFP_KERNEL);
1226 	if (!err)
1227 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1228 					  GFP_KERNEL);
1229 	if (!err)
1230 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1231 
1232 	if (err)
1233 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1234 
1235 	return err;
1236 }
1237 
1238 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1239 {
1240 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1241 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1242 	percpu_counter_destroy(&sbi->s_dirs_counter);
1243 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1244 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1245 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1246 }
1247 
1248 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1249 {
1250 	struct buffer_head **group_desc;
1251 	int i;
1252 
1253 	rcu_read_lock();
1254 	group_desc = rcu_dereference(sbi->s_group_desc);
1255 	for (i = 0; i < sbi->s_gdb_count; i++)
1256 		brelse(group_desc[i]);
1257 	kvfree(group_desc);
1258 	rcu_read_unlock();
1259 }
1260 
1261 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1262 {
1263 	struct flex_groups **flex_groups;
1264 	int i;
1265 
1266 	rcu_read_lock();
1267 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1268 	if (flex_groups) {
1269 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1270 			kvfree(flex_groups[i]);
1271 		kvfree(flex_groups);
1272 	}
1273 	rcu_read_unlock();
1274 }
1275 
1276 static void ext4_put_super(struct super_block *sb)
1277 {
1278 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1279 	struct ext4_super_block *es = sbi->s_es;
1280 	int aborted = 0;
1281 	int err;
1282 
1283 	/*
1284 	 * Unregister sysfs before destroying jbd2 journal.
1285 	 * Since we could still access attr_journal_task attribute via sysfs
1286 	 * path which could have sbi->s_journal->j_task as NULL
1287 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1288 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1289 	 * read metadata verify failed then will queue error work.
1290 	 * update_super_work will call start_this_handle may trigger
1291 	 * BUG_ON.
1292 	 */
1293 	ext4_unregister_sysfs(sb);
1294 
1295 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1296 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1297 			 &sb->s_uuid);
1298 
1299 	ext4_unregister_li_request(sb);
1300 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1301 
1302 	flush_work(&sbi->s_sb_upd_work);
1303 	destroy_workqueue(sbi->rsv_conversion_wq);
1304 	ext4_release_orphan_info(sb);
1305 
1306 	if (sbi->s_journal) {
1307 		aborted = is_journal_aborted(sbi->s_journal);
1308 		err = jbd2_journal_destroy(sbi->s_journal);
1309 		sbi->s_journal = NULL;
1310 		if ((err < 0) && !aborted) {
1311 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1312 		}
1313 	}
1314 
1315 	ext4_es_unregister_shrinker(sbi);
1316 	timer_shutdown_sync(&sbi->s_err_report);
1317 	ext4_release_system_zone(sb);
1318 	ext4_mb_release(sb);
1319 	ext4_ext_release(sb);
1320 
1321 	if (!sb_rdonly(sb) && !aborted) {
1322 		ext4_clear_feature_journal_needs_recovery(sb);
1323 		ext4_clear_feature_orphan_present(sb);
1324 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1325 	}
1326 	if (!sb_rdonly(sb))
1327 		ext4_commit_super(sb);
1328 
1329 	ext4_group_desc_free(sbi);
1330 	ext4_flex_groups_free(sbi);
1331 
1332 	WARN_ON_ONCE(!(sbi->s_mount_state & EXT4_ERROR_FS) &&
1333 		     percpu_counter_sum(&sbi->s_dirtyclusters_counter));
1334 	ext4_percpu_param_destroy(sbi);
1335 #ifdef CONFIG_QUOTA
1336 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1337 		kfree(get_qf_name(sb, sbi, i));
1338 #endif
1339 
1340 	/* Debugging code just in case the in-memory inode orphan list
1341 	 * isn't empty.  The on-disk one can be non-empty if we've
1342 	 * detected an error and taken the fs readonly, but the
1343 	 * in-memory list had better be clean by this point. */
1344 	if (!list_empty(&sbi->s_orphan))
1345 		dump_orphan_list(sb, sbi);
1346 	ASSERT(list_empty(&sbi->s_orphan));
1347 
1348 	sync_blockdev(sb->s_bdev);
1349 	invalidate_bdev(sb->s_bdev);
1350 	if (sbi->s_journal_bdev_file) {
1351 		/*
1352 		 * Invalidate the journal device's buffers.  We don't want them
1353 		 * floating about in memory - the physical journal device may
1354 		 * hotswapped, and it breaks the `ro-after' testing code.
1355 		 */
1356 		sync_blockdev(file_bdev(sbi->s_journal_bdev_file));
1357 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
1358 	}
1359 
1360 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1361 	sbi->s_ea_inode_cache = NULL;
1362 
1363 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1364 	sbi->s_ea_block_cache = NULL;
1365 
1366 	ext4_stop_mmpd(sbi);
1367 
1368 	brelse(sbi->s_sbh);
1369 	sb->s_fs_info = NULL;
1370 	/*
1371 	 * Now that we are completely done shutting down the
1372 	 * superblock, we need to actually destroy the kobject.
1373 	 */
1374 	kobject_put(&sbi->s_kobj);
1375 	wait_for_completion(&sbi->s_kobj_unregister);
1376 	if (sbi->s_chksum_driver)
1377 		crypto_free_shash(sbi->s_chksum_driver);
1378 	kfree(sbi->s_blockgroup_lock);
1379 	fs_put_dax(sbi->s_daxdev, NULL);
1380 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1381 #if IS_ENABLED(CONFIG_UNICODE)
1382 	utf8_unload(sb->s_encoding);
1383 #endif
1384 	kfree(sbi);
1385 }
1386 
1387 static struct kmem_cache *ext4_inode_cachep;
1388 
1389 /*
1390  * Called inside transaction, so use GFP_NOFS
1391  */
1392 static struct inode *ext4_alloc_inode(struct super_block *sb)
1393 {
1394 	struct ext4_inode_info *ei;
1395 
1396 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1397 	if (!ei)
1398 		return NULL;
1399 
1400 	inode_set_iversion(&ei->vfs_inode, 1);
1401 	ei->i_flags = 0;
1402 	spin_lock_init(&ei->i_raw_lock);
1403 	ei->i_prealloc_node = RB_ROOT;
1404 	atomic_set(&ei->i_prealloc_active, 0);
1405 	rwlock_init(&ei->i_prealloc_lock);
1406 	ext4_es_init_tree(&ei->i_es_tree);
1407 	rwlock_init(&ei->i_es_lock);
1408 	INIT_LIST_HEAD(&ei->i_es_list);
1409 	ei->i_es_all_nr = 0;
1410 	ei->i_es_shk_nr = 0;
1411 	ei->i_es_shrink_lblk = 0;
1412 	ei->i_reserved_data_blocks = 0;
1413 	spin_lock_init(&(ei->i_block_reservation_lock));
1414 	ext4_init_pending_tree(&ei->i_pending_tree);
1415 #ifdef CONFIG_QUOTA
1416 	ei->i_reserved_quota = 0;
1417 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1418 #endif
1419 	ei->jinode = NULL;
1420 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1421 	spin_lock_init(&ei->i_completed_io_lock);
1422 	ei->i_sync_tid = 0;
1423 	ei->i_datasync_tid = 0;
1424 	atomic_set(&ei->i_unwritten, 0);
1425 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1426 	ext4_fc_init_inode(&ei->vfs_inode);
1427 	mutex_init(&ei->i_fc_lock);
1428 	return &ei->vfs_inode;
1429 }
1430 
1431 static int ext4_drop_inode(struct inode *inode)
1432 {
1433 	int drop = generic_drop_inode(inode);
1434 
1435 	if (!drop)
1436 		drop = fscrypt_drop_inode(inode);
1437 
1438 	trace_ext4_drop_inode(inode, drop);
1439 	return drop;
1440 }
1441 
1442 static void ext4_free_in_core_inode(struct inode *inode)
1443 {
1444 	fscrypt_free_inode(inode);
1445 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1446 		pr_warn("%s: inode %ld still in fc list",
1447 			__func__, inode->i_ino);
1448 	}
1449 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1450 }
1451 
1452 static void ext4_destroy_inode(struct inode *inode)
1453 {
1454 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1455 		ext4_msg(inode->i_sb, KERN_ERR,
1456 			 "Inode %lu (%p): orphan list check failed!",
1457 			 inode->i_ino, EXT4_I(inode));
1458 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1459 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1460 				true);
1461 		dump_stack();
1462 	}
1463 
1464 	if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
1465 	    WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
1466 		ext4_msg(inode->i_sb, KERN_ERR,
1467 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1468 			 inode->i_ino, EXT4_I(inode),
1469 			 EXT4_I(inode)->i_reserved_data_blocks);
1470 }
1471 
1472 static void ext4_shutdown(struct super_block *sb)
1473 {
1474        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1475 }
1476 
1477 static void init_once(void *foo)
1478 {
1479 	struct ext4_inode_info *ei = foo;
1480 
1481 	INIT_LIST_HEAD(&ei->i_orphan);
1482 	init_rwsem(&ei->xattr_sem);
1483 	init_rwsem(&ei->i_data_sem);
1484 	inode_init_once(&ei->vfs_inode);
1485 	ext4_fc_init_inode(&ei->vfs_inode);
1486 }
1487 
1488 static int __init init_inodecache(void)
1489 {
1490 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1491 				sizeof(struct ext4_inode_info), 0,
1492 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
1493 				offsetof(struct ext4_inode_info, i_data),
1494 				sizeof_field(struct ext4_inode_info, i_data),
1495 				init_once);
1496 	if (ext4_inode_cachep == NULL)
1497 		return -ENOMEM;
1498 	return 0;
1499 }
1500 
1501 static void destroy_inodecache(void)
1502 {
1503 	/*
1504 	 * Make sure all delayed rcu free inodes are flushed before we
1505 	 * destroy cache.
1506 	 */
1507 	rcu_barrier();
1508 	kmem_cache_destroy(ext4_inode_cachep);
1509 }
1510 
1511 void ext4_clear_inode(struct inode *inode)
1512 {
1513 	ext4_fc_del(inode);
1514 	invalidate_inode_buffers(inode);
1515 	clear_inode(inode);
1516 	ext4_discard_preallocations(inode);
1517 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1518 	dquot_drop(inode);
1519 	if (EXT4_I(inode)->jinode) {
1520 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1521 					       EXT4_I(inode)->jinode);
1522 		jbd2_free_inode(EXT4_I(inode)->jinode);
1523 		EXT4_I(inode)->jinode = NULL;
1524 	}
1525 	fscrypt_put_encryption_info(inode);
1526 	fsverity_cleanup_inode(inode);
1527 }
1528 
1529 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1530 					u64 ino, u32 generation)
1531 {
1532 	struct inode *inode;
1533 
1534 	/*
1535 	 * Currently we don't know the generation for parent directory, so
1536 	 * a generation of 0 means "accept any"
1537 	 */
1538 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1539 	if (IS_ERR(inode))
1540 		return ERR_CAST(inode);
1541 	if (generation && inode->i_generation != generation) {
1542 		iput(inode);
1543 		return ERR_PTR(-ESTALE);
1544 	}
1545 
1546 	return inode;
1547 }
1548 
1549 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1550 					int fh_len, int fh_type)
1551 {
1552 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1553 				    ext4_nfs_get_inode);
1554 }
1555 
1556 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1557 					int fh_len, int fh_type)
1558 {
1559 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1560 				    ext4_nfs_get_inode);
1561 }
1562 
1563 static int ext4_nfs_commit_metadata(struct inode *inode)
1564 {
1565 	struct writeback_control wbc = {
1566 		.sync_mode = WB_SYNC_ALL
1567 	};
1568 
1569 	trace_ext4_nfs_commit_metadata(inode);
1570 	return ext4_write_inode(inode, &wbc);
1571 }
1572 
1573 #ifdef CONFIG_QUOTA
1574 static const char * const quotatypes[] = INITQFNAMES;
1575 #define QTYPE2NAME(t) (quotatypes[t])
1576 
1577 static int ext4_write_dquot(struct dquot *dquot);
1578 static int ext4_acquire_dquot(struct dquot *dquot);
1579 static int ext4_release_dquot(struct dquot *dquot);
1580 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1581 static int ext4_write_info(struct super_block *sb, int type);
1582 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1583 			 const struct path *path);
1584 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1585 			       size_t len, loff_t off);
1586 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1587 				const char *data, size_t len, loff_t off);
1588 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1589 			     unsigned int flags);
1590 
1591 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1592 {
1593 	return EXT4_I(inode)->i_dquot;
1594 }
1595 
1596 static const struct dquot_operations ext4_quota_operations = {
1597 	.get_reserved_space	= ext4_get_reserved_space,
1598 	.write_dquot		= ext4_write_dquot,
1599 	.acquire_dquot		= ext4_acquire_dquot,
1600 	.release_dquot		= ext4_release_dquot,
1601 	.mark_dirty		= ext4_mark_dquot_dirty,
1602 	.write_info		= ext4_write_info,
1603 	.alloc_dquot		= dquot_alloc,
1604 	.destroy_dquot		= dquot_destroy,
1605 	.get_projid		= ext4_get_projid,
1606 	.get_inode_usage	= ext4_get_inode_usage,
1607 	.get_next_id		= dquot_get_next_id,
1608 };
1609 
1610 static const struct quotactl_ops ext4_qctl_operations = {
1611 	.quota_on	= ext4_quota_on,
1612 	.quota_off	= ext4_quota_off,
1613 	.quota_sync	= dquot_quota_sync,
1614 	.get_state	= dquot_get_state,
1615 	.set_info	= dquot_set_dqinfo,
1616 	.get_dqblk	= dquot_get_dqblk,
1617 	.set_dqblk	= dquot_set_dqblk,
1618 	.get_nextdqblk	= dquot_get_next_dqblk,
1619 };
1620 #endif
1621 
1622 static const struct super_operations ext4_sops = {
1623 	.alloc_inode	= ext4_alloc_inode,
1624 	.free_inode	= ext4_free_in_core_inode,
1625 	.destroy_inode	= ext4_destroy_inode,
1626 	.write_inode	= ext4_write_inode,
1627 	.dirty_inode	= ext4_dirty_inode,
1628 	.drop_inode	= ext4_drop_inode,
1629 	.evict_inode	= ext4_evict_inode,
1630 	.put_super	= ext4_put_super,
1631 	.sync_fs	= ext4_sync_fs,
1632 	.freeze_fs	= ext4_freeze,
1633 	.unfreeze_fs	= ext4_unfreeze,
1634 	.statfs		= ext4_statfs,
1635 	.show_options	= ext4_show_options,
1636 	.shutdown	= ext4_shutdown,
1637 #ifdef CONFIG_QUOTA
1638 	.quota_read	= ext4_quota_read,
1639 	.quota_write	= ext4_quota_write,
1640 	.get_dquots	= ext4_get_dquots,
1641 #endif
1642 };
1643 
1644 static const struct export_operations ext4_export_ops = {
1645 	.encode_fh = generic_encode_ino32_fh,
1646 	.fh_to_dentry = ext4_fh_to_dentry,
1647 	.fh_to_parent = ext4_fh_to_parent,
1648 	.get_parent = ext4_get_parent,
1649 	.commit_metadata = ext4_nfs_commit_metadata,
1650 };
1651 
1652 enum {
1653 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1654 	Opt_resgid, Opt_resuid, Opt_sb,
1655 	Opt_nouid32, Opt_debug, Opt_removed,
1656 	Opt_user_xattr, Opt_acl,
1657 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1658 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1659 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1660 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1661 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1662 	Opt_inlinecrypt,
1663 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1664 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1665 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1666 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1667 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1668 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1669 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1670 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1671 	Opt_dioread_nolock, Opt_dioread_lock,
1672 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1673 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1674 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1675 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1676 #ifdef CONFIG_EXT4_DEBUG
1677 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1678 #endif
1679 };
1680 
1681 static const struct constant_table ext4_param_errors[] = {
1682 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1683 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1684 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1685 	{}
1686 };
1687 
1688 static const struct constant_table ext4_param_data[] = {
1689 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1690 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1691 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1692 	{}
1693 };
1694 
1695 static const struct constant_table ext4_param_data_err[] = {
1696 	{"abort",	Opt_data_err_abort},
1697 	{"ignore",	Opt_data_err_ignore},
1698 	{}
1699 };
1700 
1701 static const struct constant_table ext4_param_jqfmt[] = {
1702 	{"vfsold",	QFMT_VFS_OLD},
1703 	{"vfsv0",	QFMT_VFS_V0},
1704 	{"vfsv1",	QFMT_VFS_V1},
1705 	{}
1706 };
1707 
1708 static const struct constant_table ext4_param_dax[] = {
1709 	{"always",	Opt_dax_always},
1710 	{"inode",	Opt_dax_inode},
1711 	{"never",	Opt_dax_never},
1712 	{}
1713 };
1714 
1715 /*
1716  * Mount option specification
1717  * We don't use fsparam_flag_no because of the way we set the
1718  * options and the way we show them in _ext4_show_options(). To
1719  * keep the changes to a minimum, let's keep the negative options
1720  * separate for now.
1721  */
1722 static const struct fs_parameter_spec ext4_param_specs[] = {
1723 	fsparam_flag	("bsddf",		Opt_bsd_df),
1724 	fsparam_flag	("minixdf",		Opt_minix_df),
1725 	fsparam_flag	("grpid",		Opt_grpid),
1726 	fsparam_flag	("bsdgroups",		Opt_grpid),
1727 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1728 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1729 	fsparam_gid	("resgid",		Opt_resgid),
1730 	fsparam_uid	("resuid",		Opt_resuid),
1731 	fsparam_u32	("sb",			Opt_sb),
1732 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1733 	fsparam_flag	("nouid32",		Opt_nouid32),
1734 	fsparam_flag	("debug",		Opt_debug),
1735 	fsparam_flag	("oldalloc",		Opt_removed),
1736 	fsparam_flag	("orlov",		Opt_removed),
1737 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1738 	fsparam_flag	("acl",			Opt_acl),
1739 	fsparam_flag	("norecovery",		Opt_noload),
1740 	fsparam_flag	("noload",		Opt_noload),
1741 	fsparam_flag	("bh",			Opt_removed),
1742 	fsparam_flag	("nobh",		Opt_removed),
1743 	fsparam_u32	("commit",		Opt_commit),
1744 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1745 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1746 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1747 	fsparam_bdev	("journal_path",	Opt_journal_path),
1748 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1749 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1750 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1751 	fsparam_flag	("abort",		Opt_abort),
1752 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1753 	fsparam_enum	("data_err",		Opt_data_err,
1754 						ext4_param_data_err),
1755 	fsparam_string_empty
1756 			("usrjquota",		Opt_usrjquota),
1757 	fsparam_string_empty
1758 			("grpjquota",		Opt_grpjquota),
1759 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1760 	fsparam_flag	("grpquota",		Opt_grpquota),
1761 	fsparam_flag	("quota",		Opt_quota),
1762 	fsparam_flag	("noquota",		Opt_noquota),
1763 	fsparam_flag	("usrquota",		Opt_usrquota),
1764 	fsparam_flag	("prjquota",		Opt_prjquota),
1765 	fsparam_flag	("barrier",		Opt_barrier),
1766 	fsparam_u32	("barrier",		Opt_barrier),
1767 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1768 	fsparam_flag	("i_version",		Opt_removed),
1769 	fsparam_flag	("dax",			Opt_dax),
1770 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1771 	fsparam_u32	("stripe",		Opt_stripe),
1772 	fsparam_flag	("delalloc",		Opt_delalloc),
1773 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1774 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1775 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1776 	fsparam_u32	("debug_want_extra_isize",
1777 						Opt_debug_want_extra_isize),
1778 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1779 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1780 	fsparam_flag	("block_validity",	Opt_block_validity),
1781 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1782 	fsparam_u32	("inode_readahead_blks",
1783 						Opt_inode_readahead_blks),
1784 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1785 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1786 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1787 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1788 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1789 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1790 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1791 	fsparam_flag	("discard",		Opt_discard),
1792 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1793 	fsparam_u32	("init_itable",		Opt_init_itable),
1794 	fsparam_flag	("init_itable",		Opt_init_itable),
1795 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1796 #ifdef CONFIG_EXT4_DEBUG
1797 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1798 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1799 #endif
1800 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1801 	fsparam_flag	("test_dummy_encryption",
1802 						Opt_test_dummy_encryption),
1803 	fsparam_string	("test_dummy_encryption",
1804 						Opt_test_dummy_encryption),
1805 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1806 	fsparam_flag	("nombcache",		Opt_nombcache),
1807 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1808 	fsparam_flag	("prefetch_block_bitmaps",
1809 						Opt_removed),
1810 	fsparam_flag	("no_prefetch_block_bitmaps",
1811 						Opt_no_prefetch_block_bitmaps),
1812 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1813 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1814 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1815 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1816 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1817 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1818 	{}
1819 };
1820 
1821 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1822 
1823 #define MOPT_SET	0x0001
1824 #define MOPT_CLEAR	0x0002
1825 #define MOPT_NOSUPPORT	0x0004
1826 #define MOPT_EXPLICIT	0x0008
1827 #ifdef CONFIG_QUOTA
1828 #define MOPT_Q		0
1829 #define MOPT_QFMT	0x0010
1830 #else
1831 #define MOPT_Q		MOPT_NOSUPPORT
1832 #define MOPT_QFMT	MOPT_NOSUPPORT
1833 #endif
1834 #define MOPT_NO_EXT2	0x0020
1835 #define MOPT_NO_EXT3	0x0040
1836 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1837 #define MOPT_SKIP	0x0080
1838 #define	MOPT_2		0x0100
1839 
1840 static const struct mount_opts {
1841 	int	token;
1842 	int	mount_opt;
1843 	int	flags;
1844 } ext4_mount_opts[] = {
1845 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1846 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1847 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1848 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1849 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1850 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1851 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1852 	 MOPT_EXT4_ONLY | MOPT_SET},
1853 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1854 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1855 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1856 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1857 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1858 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1859 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1860 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1861 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1862 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1863 	{Opt_commit, 0, MOPT_NO_EXT2},
1864 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1865 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1866 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1867 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1868 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1869 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1870 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1871 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1872 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1873 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1874 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1875 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1876 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1877 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1878 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1879 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1880 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1881 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1882 	{Opt_data, 0, MOPT_NO_EXT2},
1883 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1884 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1885 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1886 #else
1887 	{Opt_acl, 0, MOPT_NOSUPPORT},
1888 #endif
1889 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1890 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1891 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1892 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1893 							MOPT_SET | MOPT_Q},
1894 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1895 							MOPT_SET | MOPT_Q},
1896 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1897 							MOPT_SET | MOPT_Q},
1898 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1899 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1900 							MOPT_CLEAR | MOPT_Q},
1901 	{Opt_usrjquota, 0, MOPT_Q},
1902 	{Opt_grpjquota, 0, MOPT_Q},
1903 	{Opt_jqfmt, 0, MOPT_QFMT},
1904 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1905 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1906 	 MOPT_SET},
1907 #ifdef CONFIG_EXT4_DEBUG
1908 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1909 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1910 #endif
1911 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1912 	{Opt_err, 0, 0}
1913 };
1914 
1915 #if IS_ENABLED(CONFIG_UNICODE)
1916 static const struct ext4_sb_encodings {
1917 	__u16 magic;
1918 	char *name;
1919 	unsigned int version;
1920 } ext4_sb_encoding_map[] = {
1921 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1922 };
1923 
1924 static const struct ext4_sb_encodings *
1925 ext4_sb_read_encoding(const struct ext4_super_block *es)
1926 {
1927 	__u16 magic = le16_to_cpu(es->s_encoding);
1928 	int i;
1929 
1930 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1931 		if (magic == ext4_sb_encoding_map[i].magic)
1932 			return &ext4_sb_encoding_map[i];
1933 
1934 	return NULL;
1935 }
1936 #endif
1937 
1938 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1939 #define EXT4_SPEC_JQFMT				(1 <<  1)
1940 #define EXT4_SPEC_DATAJ				(1 <<  2)
1941 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1942 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1943 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1944 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1945 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1946 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1947 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1948 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1949 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1950 #define EXT4_SPEC_s_stripe			(1 << 13)
1951 #define EXT4_SPEC_s_resuid			(1 << 14)
1952 #define EXT4_SPEC_s_resgid			(1 << 15)
1953 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1954 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1955 #define EXT4_SPEC_s_sb_block			(1 << 18)
1956 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1957 
1958 struct ext4_fs_context {
1959 	char		*s_qf_names[EXT4_MAXQUOTAS];
1960 	struct fscrypt_dummy_policy dummy_enc_policy;
1961 	int		s_jquota_fmt;	/* Format of quota to use */
1962 #ifdef CONFIG_EXT4_DEBUG
1963 	int s_fc_debug_max_replay;
1964 #endif
1965 	unsigned short	qname_spec;
1966 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1967 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1968 	unsigned long	journal_devnum;
1969 	unsigned long	s_commit_interval;
1970 	unsigned long	s_stripe;
1971 	unsigned int	s_inode_readahead_blks;
1972 	unsigned int	s_want_extra_isize;
1973 	unsigned int	s_li_wait_mult;
1974 	unsigned int	s_max_dir_size_kb;
1975 	unsigned int	journal_ioprio;
1976 	unsigned int	vals_s_mount_opt;
1977 	unsigned int	mask_s_mount_opt;
1978 	unsigned int	vals_s_mount_opt2;
1979 	unsigned int	mask_s_mount_opt2;
1980 	unsigned int	opt_flags;	/* MOPT flags */
1981 	unsigned int	spec;
1982 	u32		s_max_batch_time;
1983 	u32		s_min_batch_time;
1984 	kuid_t		s_resuid;
1985 	kgid_t		s_resgid;
1986 	ext4_fsblk_t	s_sb_block;
1987 };
1988 
1989 static void ext4_fc_free(struct fs_context *fc)
1990 {
1991 	struct ext4_fs_context *ctx = fc->fs_private;
1992 	int i;
1993 
1994 	if (!ctx)
1995 		return;
1996 
1997 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1998 		kfree(ctx->s_qf_names[i]);
1999 
2000 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2001 	kfree(ctx);
2002 }
2003 
2004 int ext4_init_fs_context(struct fs_context *fc)
2005 {
2006 	struct ext4_fs_context *ctx;
2007 
2008 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2009 	if (!ctx)
2010 		return -ENOMEM;
2011 
2012 	fc->fs_private = ctx;
2013 	fc->ops = &ext4_context_ops;
2014 
2015 	return 0;
2016 }
2017 
2018 #ifdef CONFIG_QUOTA
2019 /*
2020  * Note the name of the specified quota file.
2021  */
2022 static int note_qf_name(struct fs_context *fc, int qtype,
2023 		       struct fs_parameter *param)
2024 {
2025 	struct ext4_fs_context *ctx = fc->fs_private;
2026 	char *qname;
2027 
2028 	if (param->size < 1) {
2029 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2030 		return -EINVAL;
2031 	}
2032 	if (strchr(param->string, '/')) {
2033 		ext4_msg(NULL, KERN_ERR,
2034 			 "quotafile must be on filesystem root");
2035 		return -EINVAL;
2036 	}
2037 	if (ctx->s_qf_names[qtype]) {
2038 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2039 			ext4_msg(NULL, KERN_ERR,
2040 				 "%s quota file already specified",
2041 				 QTYPE2NAME(qtype));
2042 			return -EINVAL;
2043 		}
2044 		return 0;
2045 	}
2046 
2047 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2048 	if (!qname) {
2049 		ext4_msg(NULL, KERN_ERR,
2050 			 "Not enough memory for storing quotafile name");
2051 		return -ENOMEM;
2052 	}
2053 	ctx->s_qf_names[qtype] = qname;
2054 	ctx->qname_spec |= 1 << qtype;
2055 	ctx->spec |= EXT4_SPEC_JQUOTA;
2056 	return 0;
2057 }
2058 
2059 /*
2060  * Clear the name of the specified quota file.
2061  */
2062 static int unnote_qf_name(struct fs_context *fc, int qtype)
2063 {
2064 	struct ext4_fs_context *ctx = fc->fs_private;
2065 
2066 	kfree(ctx->s_qf_names[qtype]);
2067 
2068 	ctx->s_qf_names[qtype] = NULL;
2069 	ctx->qname_spec |= 1 << qtype;
2070 	ctx->spec |= EXT4_SPEC_JQUOTA;
2071 	return 0;
2072 }
2073 #endif
2074 
2075 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2076 					    struct ext4_fs_context *ctx)
2077 {
2078 	int err;
2079 
2080 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2081 		ext4_msg(NULL, KERN_WARNING,
2082 			 "test_dummy_encryption option not supported");
2083 		return -EINVAL;
2084 	}
2085 	err = fscrypt_parse_test_dummy_encryption(param,
2086 						  &ctx->dummy_enc_policy);
2087 	if (err == -EINVAL) {
2088 		ext4_msg(NULL, KERN_WARNING,
2089 			 "Value of option \"%s\" is unrecognized", param->key);
2090 	} else if (err == -EEXIST) {
2091 		ext4_msg(NULL, KERN_WARNING,
2092 			 "Conflicting test_dummy_encryption options");
2093 		return -EINVAL;
2094 	}
2095 	return err;
2096 }
2097 
2098 #define EXT4_SET_CTX(name)						\
2099 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2100 				  unsigned long flag)			\
2101 {									\
2102 	ctx->mask_s_##name |= flag;					\
2103 	ctx->vals_s_##name |= flag;					\
2104 }
2105 
2106 #define EXT4_CLEAR_CTX(name)						\
2107 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2108 				    unsigned long flag)			\
2109 {									\
2110 	ctx->mask_s_##name |= flag;					\
2111 	ctx->vals_s_##name &= ~flag;					\
2112 }
2113 
2114 #define EXT4_TEST_CTX(name)						\
2115 static inline unsigned long						\
2116 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2117 {									\
2118 	return (ctx->vals_s_##name & flag);				\
2119 }
2120 
2121 EXT4_SET_CTX(flags); /* set only */
2122 EXT4_SET_CTX(mount_opt);
2123 EXT4_CLEAR_CTX(mount_opt);
2124 EXT4_TEST_CTX(mount_opt);
2125 EXT4_SET_CTX(mount_opt2);
2126 EXT4_CLEAR_CTX(mount_opt2);
2127 EXT4_TEST_CTX(mount_opt2);
2128 
2129 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2130 {
2131 	struct ext4_fs_context *ctx = fc->fs_private;
2132 	struct fs_parse_result result;
2133 	const struct mount_opts *m;
2134 	int is_remount;
2135 	int token;
2136 
2137 	token = fs_parse(fc, ext4_param_specs, param, &result);
2138 	if (token < 0)
2139 		return token;
2140 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2141 
2142 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2143 		if (token == m->token)
2144 			break;
2145 
2146 	ctx->opt_flags |= m->flags;
2147 
2148 	if (m->flags & MOPT_EXPLICIT) {
2149 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2150 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2151 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2152 			ctx_set_mount_opt2(ctx,
2153 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2154 		} else
2155 			return -EINVAL;
2156 	}
2157 
2158 	if (m->flags & MOPT_NOSUPPORT) {
2159 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2160 			 param->key);
2161 		return 0;
2162 	}
2163 
2164 	switch (token) {
2165 #ifdef CONFIG_QUOTA
2166 	case Opt_usrjquota:
2167 		if (!*param->string)
2168 			return unnote_qf_name(fc, USRQUOTA);
2169 		else
2170 			return note_qf_name(fc, USRQUOTA, param);
2171 	case Opt_grpjquota:
2172 		if (!*param->string)
2173 			return unnote_qf_name(fc, GRPQUOTA);
2174 		else
2175 			return note_qf_name(fc, GRPQUOTA, param);
2176 #endif
2177 	case Opt_sb:
2178 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2179 			ext4_msg(NULL, KERN_WARNING,
2180 				 "Ignoring %s option on remount", param->key);
2181 		} else {
2182 			ctx->s_sb_block = result.uint_32;
2183 			ctx->spec |= EXT4_SPEC_s_sb_block;
2184 		}
2185 		return 0;
2186 	case Opt_removed:
2187 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2188 			 param->key);
2189 		return 0;
2190 	case Opt_inlinecrypt:
2191 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2192 		ctx_set_flags(ctx, SB_INLINECRYPT);
2193 #else
2194 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2195 #endif
2196 		return 0;
2197 	case Opt_errors:
2198 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2199 		ctx_set_mount_opt(ctx, result.uint_32);
2200 		return 0;
2201 #ifdef CONFIG_QUOTA
2202 	case Opt_jqfmt:
2203 		ctx->s_jquota_fmt = result.uint_32;
2204 		ctx->spec |= EXT4_SPEC_JQFMT;
2205 		return 0;
2206 #endif
2207 	case Opt_data:
2208 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2209 		ctx_set_mount_opt(ctx, result.uint_32);
2210 		ctx->spec |= EXT4_SPEC_DATAJ;
2211 		return 0;
2212 	case Opt_commit:
2213 		if (result.uint_32 == 0)
2214 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2215 		else if (result.uint_32 > INT_MAX / HZ) {
2216 			ext4_msg(NULL, KERN_ERR,
2217 				 "Invalid commit interval %d, "
2218 				 "must be smaller than %d",
2219 				 result.uint_32, INT_MAX / HZ);
2220 			return -EINVAL;
2221 		}
2222 		ctx->s_commit_interval = HZ * result.uint_32;
2223 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2224 		return 0;
2225 	case Opt_debug_want_extra_isize:
2226 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2227 			ext4_msg(NULL, KERN_ERR,
2228 				 "Invalid want_extra_isize %d", result.uint_32);
2229 			return -EINVAL;
2230 		}
2231 		ctx->s_want_extra_isize = result.uint_32;
2232 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2233 		return 0;
2234 	case Opt_max_batch_time:
2235 		ctx->s_max_batch_time = result.uint_32;
2236 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2237 		return 0;
2238 	case Opt_min_batch_time:
2239 		ctx->s_min_batch_time = result.uint_32;
2240 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2241 		return 0;
2242 	case Opt_inode_readahead_blks:
2243 		if (result.uint_32 &&
2244 		    (result.uint_32 > (1 << 30) ||
2245 		     !is_power_of_2(result.uint_32))) {
2246 			ext4_msg(NULL, KERN_ERR,
2247 				 "EXT4-fs: inode_readahead_blks must be "
2248 				 "0 or a power of 2 smaller than 2^31");
2249 			return -EINVAL;
2250 		}
2251 		ctx->s_inode_readahead_blks = result.uint_32;
2252 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2253 		return 0;
2254 	case Opt_init_itable:
2255 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2256 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2257 		if (param->type == fs_value_is_string)
2258 			ctx->s_li_wait_mult = result.uint_32;
2259 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2260 		return 0;
2261 	case Opt_max_dir_size_kb:
2262 		ctx->s_max_dir_size_kb = result.uint_32;
2263 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2264 		return 0;
2265 #ifdef CONFIG_EXT4_DEBUG
2266 	case Opt_fc_debug_max_replay:
2267 		ctx->s_fc_debug_max_replay = result.uint_32;
2268 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2269 		return 0;
2270 #endif
2271 	case Opt_stripe:
2272 		ctx->s_stripe = result.uint_32;
2273 		ctx->spec |= EXT4_SPEC_s_stripe;
2274 		return 0;
2275 	case Opt_resuid:
2276 		ctx->s_resuid = result.uid;
2277 		ctx->spec |= EXT4_SPEC_s_resuid;
2278 		return 0;
2279 	case Opt_resgid:
2280 		ctx->s_resgid = result.gid;
2281 		ctx->spec |= EXT4_SPEC_s_resgid;
2282 		return 0;
2283 	case Opt_journal_dev:
2284 		if (is_remount) {
2285 			ext4_msg(NULL, KERN_ERR,
2286 				 "Cannot specify journal on remount");
2287 			return -EINVAL;
2288 		}
2289 		ctx->journal_devnum = result.uint_32;
2290 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2291 		return 0;
2292 	case Opt_journal_path:
2293 	{
2294 		struct inode *journal_inode;
2295 		struct path path;
2296 		int error;
2297 
2298 		if (is_remount) {
2299 			ext4_msg(NULL, KERN_ERR,
2300 				 "Cannot specify journal on remount");
2301 			return -EINVAL;
2302 		}
2303 
2304 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2305 		if (error) {
2306 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2307 				 "journal device path");
2308 			return -EINVAL;
2309 		}
2310 
2311 		journal_inode = d_inode(path.dentry);
2312 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2313 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2314 		path_put(&path);
2315 		return 0;
2316 	}
2317 	case Opt_journal_ioprio:
2318 		if (result.uint_32 > 7) {
2319 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2320 				 " (must be 0-7)");
2321 			return -EINVAL;
2322 		}
2323 		ctx->journal_ioprio =
2324 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2325 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2326 		return 0;
2327 	case Opt_test_dummy_encryption:
2328 		return ext4_parse_test_dummy_encryption(param, ctx);
2329 	case Opt_dax:
2330 	case Opt_dax_type:
2331 #ifdef CONFIG_FS_DAX
2332 	{
2333 		int type = (token == Opt_dax) ?
2334 			   Opt_dax : result.uint_32;
2335 
2336 		switch (type) {
2337 		case Opt_dax:
2338 		case Opt_dax_always:
2339 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2340 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2341 			break;
2342 		case Opt_dax_never:
2343 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2344 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2345 			break;
2346 		case Opt_dax_inode:
2347 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2348 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2349 			/* Strictly for printing options */
2350 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2351 			break;
2352 		}
2353 		return 0;
2354 	}
2355 #else
2356 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2357 		return -EINVAL;
2358 #endif
2359 	case Opt_data_err:
2360 		if (result.uint_32 == Opt_data_err_abort)
2361 			ctx_set_mount_opt(ctx, m->mount_opt);
2362 		else if (result.uint_32 == Opt_data_err_ignore)
2363 			ctx_clear_mount_opt(ctx, m->mount_opt);
2364 		return 0;
2365 	case Opt_mb_optimize_scan:
2366 		if (result.int_32 == 1) {
2367 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2368 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2369 		} else if (result.int_32 == 0) {
2370 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2371 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2372 		} else {
2373 			ext4_msg(NULL, KERN_WARNING,
2374 				 "mb_optimize_scan should be set to 0 or 1.");
2375 			return -EINVAL;
2376 		}
2377 		return 0;
2378 	}
2379 
2380 	/*
2381 	 * At this point we should only be getting options requiring MOPT_SET,
2382 	 * or MOPT_CLEAR. Anything else is a bug
2383 	 */
2384 	if (m->token == Opt_err) {
2385 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2386 			 param->key);
2387 		WARN_ON(1);
2388 		return -EINVAL;
2389 	}
2390 
2391 	else {
2392 		unsigned int set = 0;
2393 
2394 		if ((param->type == fs_value_is_flag) ||
2395 		    result.uint_32 > 0)
2396 			set = 1;
2397 
2398 		if (m->flags & MOPT_CLEAR)
2399 			set = !set;
2400 		else if (unlikely(!(m->flags & MOPT_SET))) {
2401 			ext4_msg(NULL, KERN_WARNING,
2402 				 "buggy handling of option %s",
2403 				 param->key);
2404 			WARN_ON(1);
2405 			return -EINVAL;
2406 		}
2407 		if (m->flags & MOPT_2) {
2408 			if (set != 0)
2409 				ctx_set_mount_opt2(ctx, m->mount_opt);
2410 			else
2411 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2412 		} else {
2413 			if (set != 0)
2414 				ctx_set_mount_opt(ctx, m->mount_opt);
2415 			else
2416 				ctx_clear_mount_opt(ctx, m->mount_opt);
2417 		}
2418 	}
2419 
2420 	return 0;
2421 }
2422 
2423 static int parse_options(struct fs_context *fc, char *options)
2424 {
2425 	struct fs_parameter param;
2426 	int ret;
2427 	char *key;
2428 
2429 	if (!options)
2430 		return 0;
2431 
2432 	while ((key = strsep(&options, ",")) != NULL) {
2433 		if (*key) {
2434 			size_t v_len = 0;
2435 			char *value = strchr(key, '=');
2436 
2437 			param.type = fs_value_is_flag;
2438 			param.string = NULL;
2439 
2440 			if (value) {
2441 				if (value == key)
2442 					continue;
2443 
2444 				*value++ = 0;
2445 				v_len = strlen(value);
2446 				param.string = kmemdup_nul(value, v_len,
2447 							   GFP_KERNEL);
2448 				if (!param.string)
2449 					return -ENOMEM;
2450 				param.type = fs_value_is_string;
2451 			}
2452 
2453 			param.key = key;
2454 			param.size = v_len;
2455 
2456 			ret = ext4_parse_param(fc, &param);
2457 			kfree(param.string);
2458 			if (ret < 0)
2459 				return ret;
2460 		}
2461 	}
2462 
2463 	ret = ext4_validate_options(fc);
2464 	if (ret < 0)
2465 		return ret;
2466 
2467 	return 0;
2468 }
2469 
2470 static int parse_apply_sb_mount_options(struct super_block *sb,
2471 					struct ext4_fs_context *m_ctx)
2472 {
2473 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2474 	char *s_mount_opts = NULL;
2475 	struct ext4_fs_context *s_ctx = NULL;
2476 	struct fs_context *fc = NULL;
2477 	int ret = -ENOMEM;
2478 
2479 	if (!sbi->s_es->s_mount_opts[0])
2480 		return 0;
2481 
2482 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2483 				sizeof(sbi->s_es->s_mount_opts),
2484 				GFP_KERNEL);
2485 	if (!s_mount_opts)
2486 		return ret;
2487 
2488 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2489 	if (!fc)
2490 		goto out_free;
2491 
2492 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2493 	if (!s_ctx)
2494 		goto out_free;
2495 
2496 	fc->fs_private = s_ctx;
2497 	fc->s_fs_info = sbi;
2498 
2499 	ret = parse_options(fc, s_mount_opts);
2500 	if (ret < 0)
2501 		goto parse_failed;
2502 
2503 	ret = ext4_check_opt_consistency(fc, sb);
2504 	if (ret < 0) {
2505 parse_failed:
2506 		ext4_msg(sb, KERN_WARNING,
2507 			 "failed to parse options in superblock: %s",
2508 			 s_mount_opts);
2509 		ret = 0;
2510 		goto out_free;
2511 	}
2512 
2513 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2514 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2515 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2516 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2517 
2518 	ext4_apply_options(fc, sb);
2519 	ret = 0;
2520 
2521 out_free:
2522 	if (fc) {
2523 		ext4_fc_free(fc);
2524 		kfree(fc);
2525 	}
2526 	kfree(s_mount_opts);
2527 	return ret;
2528 }
2529 
2530 static void ext4_apply_quota_options(struct fs_context *fc,
2531 				     struct super_block *sb)
2532 {
2533 #ifdef CONFIG_QUOTA
2534 	bool quota_feature = ext4_has_feature_quota(sb);
2535 	struct ext4_fs_context *ctx = fc->fs_private;
2536 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2537 	char *qname;
2538 	int i;
2539 
2540 	if (quota_feature)
2541 		return;
2542 
2543 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2544 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2545 			if (!(ctx->qname_spec & (1 << i)))
2546 				continue;
2547 
2548 			qname = ctx->s_qf_names[i]; /* May be NULL */
2549 			if (qname)
2550 				set_opt(sb, QUOTA);
2551 			ctx->s_qf_names[i] = NULL;
2552 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2553 						lockdep_is_held(&sb->s_umount));
2554 			if (qname)
2555 				kfree_rcu_mightsleep(qname);
2556 		}
2557 	}
2558 
2559 	if (ctx->spec & EXT4_SPEC_JQFMT)
2560 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2561 #endif
2562 }
2563 
2564 /*
2565  * Check quota settings consistency.
2566  */
2567 static int ext4_check_quota_consistency(struct fs_context *fc,
2568 					struct super_block *sb)
2569 {
2570 #ifdef CONFIG_QUOTA
2571 	struct ext4_fs_context *ctx = fc->fs_private;
2572 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2573 	bool quota_feature = ext4_has_feature_quota(sb);
2574 	bool quota_loaded = sb_any_quota_loaded(sb);
2575 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2576 	int quota_flags, i;
2577 
2578 	/*
2579 	 * We do the test below only for project quotas. 'usrquota' and
2580 	 * 'grpquota' mount options are allowed even without quota feature
2581 	 * to support legacy quotas in quota files.
2582 	 */
2583 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2584 	    !ext4_has_feature_project(sb)) {
2585 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2586 			 "Cannot enable project quota enforcement.");
2587 		return -EINVAL;
2588 	}
2589 
2590 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2591 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2592 	if (quota_loaded &&
2593 	    ctx->mask_s_mount_opt & quota_flags &&
2594 	    !ctx_test_mount_opt(ctx, quota_flags))
2595 		goto err_quota_change;
2596 
2597 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2598 
2599 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2600 			if (!(ctx->qname_spec & (1 << i)))
2601 				continue;
2602 
2603 			if (quota_loaded &&
2604 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2605 				goto err_jquota_change;
2606 
2607 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2608 			    strcmp(get_qf_name(sb, sbi, i),
2609 				   ctx->s_qf_names[i]) != 0)
2610 				goto err_jquota_specified;
2611 		}
2612 
2613 		if (quota_feature) {
2614 			ext4_msg(NULL, KERN_INFO,
2615 				 "Journaled quota options ignored when "
2616 				 "QUOTA feature is enabled");
2617 			return 0;
2618 		}
2619 	}
2620 
2621 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2622 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2623 			goto err_jquota_change;
2624 		if (quota_feature) {
2625 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2626 				 "ignored when QUOTA feature is enabled");
2627 			return 0;
2628 		}
2629 	}
2630 
2631 	/* Make sure we don't mix old and new quota format */
2632 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2633 		       ctx->s_qf_names[USRQUOTA]);
2634 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2635 		       ctx->s_qf_names[GRPQUOTA]);
2636 
2637 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2638 		    test_opt(sb, USRQUOTA));
2639 
2640 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2641 		    test_opt(sb, GRPQUOTA));
2642 
2643 	if (usr_qf_name) {
2644 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2645 		usrquota = false;
2646 	}
2647 	if (grp_qf_name) {
2648 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2649 		grpquota = false;
2650 	}
2651 
2652 	if (usr_qf_name || grp_qf_name) {
2653 		if (usrquota || grpquota) {
2654 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2655 				 "format mixing");
2656 			return -EINVAL;
2657 		}
2658 
2659 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2660 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2661 				 "not specified");
2662 			return -EINVAL;
2663 		}
2664 	}
2665 
2666 	return 0;
2667 
2668 err_quota_change:
2669 	ext4_msg(NULL, KERN_ERR,
2670 		 "Cannot change quota options when quota turned on");
2671 	return -EINVAL;
2672 err_jquota_change:
2673 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2674 		 "options when quota turned on");
2675 	return -EINVAL;
2676 err_jquota_specified:
2677 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2678 		 QTYPE2NAME(i));
2679 	return -EINVAL;
2680 #else
2681 	return 0;
2682 #endif
2683 }
2684 
2685 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2686 					    struct super_block *sb)
2687 {
2688 	const struct ext4_fs_context *ctx = fc->fs_private;
2689 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2690 
2691 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2692 		return 0;
2693 
2694 	if (!ext4_has_feature_encrypt(sb)) {
2695 		ext4_msg(NULL, KERN_WARNING,
2696 			 "test_dummy_encryption requires encrypt feature");
2697 		return -EINVAL;
2698 	}
2699 	/*
2700 	 * This mount option is just for testing, and it's not worthwhile to
2701 	 * implement the extra complexity (e.g. RCU protection) that would be
2702 	 * needed to allow it to be set or changed during remount.  We do allow
2703 	 * it to be specified during remount, but only if there is no change.
2704 	 */
2705 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2706 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2707 						 &ctx->dummy_enc_policy))
2708 			return 0;
2709 		ext4_msg(NULL, KERN_WARNING,
2710 			 "Can't set or change test_dummy_encryption on remount");
2711 		return -EINVAL;
2712 	}
2713 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2714 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2715 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2716 						 &ctx->dummy_enc_policy))
2717 			return 0;
2718 		ext4_msg(NULL, KERN_WARNING,
2719 			 "Conflicting test_dummy_encryption options");
2720 		return -EINVAL;
2721 	}
2722 	return 0;
2723 }
2724 
2725 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2726 					     struct super_block *sb)
2727 {
2728 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2729 	    /* if already set, it was already verified to be the same */
2730 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2731 		return;
2732 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2733 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2734 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2735 }
2736 
2737 static int ext4_check_opt_consistency(struct fs_context *fc,
2738 				      struct super_block *sb)
2739 {
2740 	struct ext4_fs_context *ctx = fc->fs_private;
2741 	struct ext4_sb_info *sbi = fc->s_fs_info;
2742 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2743 	int err;
2744 
2745 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2746 		ext4_msg(NULL, KERN_ERR,
2747 			 "Mount option(s) incompatible with ext2");
2748 		return -EINVAL;
2749 	}
2750 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2751 		ext4_msg(NULL, KERN_ERR,
2752 			 "Mount option(s) incompatible with ext3");
2753 		return -EINVAL;
2754 	}
2755 
2756 	if (ctx->s_want_extra_isize >
2757 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2758 		ext4_msg(NULL, KERN_ERR,
2759 			 "Invalid want_extra_isize %d",
2760 			 ctx->s_want_extra_isize);
2761 		return -EINVAL;
2762 	}
2763 
2764 	err = ext4_check_test_dummy_encryption(fc, sb);
2765 	if (err)
2766 		return err;
2767 
2768 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2769 		if (!sbi->s_journal) {
2770 			ext4_msg(NULL, KERN_WARNING,
2771 				 "Remounting file system with no journal "
2772 				 "so ignoring journalled data option");
2773 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2774 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2775 			   test_opt(sb, DATA_FLAGS)) {
2776 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2777 				 "on remount");
2778 			return -EINVAL;
2779 		}
2780 	}
2781 
2782 	if (is_remount) {
2783 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2784 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2785 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2786 				 "both data=journal and dax");
2787 			return -EINVAL;
2788 		}
2789 
2790 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2791 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2792 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2793 fail_dax_change_remount:
2794 			ext4_msg(NULL, KERN_ERR, "can't change "
2795 				 "dax mount option while remounting");
2796 			return -EINVAL;
2797 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2798 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2799 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2800 			goto fail_dax_change_remount;
2801 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2802 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2803 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2804 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2805 			goto fail_dax_change_remount;
2806 		}
2807 	}
2808 
2809 	return ext4_check_quota_consistency(fc, sb);
2810 }
2811 
2812 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2813 {
2814 	struct ext4_fs_context *ctx = fc->fs_private;
2815 	struct ext4_sb_info *sbi = fc->s_fs_info;
2816 
2817 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2818 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2819 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2820 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2821 	sb->s_flags &= ~ctx->mask_s_flags;
2822 	sb->s_flags |= ctx->vals_s_flags;
2823 
2824 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2825 	APPLY(s_commit_interval);
2826 	APPLY(s_stripe);
2827 	APPLY(s_max_batch_time);
2828 	APPLY(s_min_batch_time);
2829 	APPLY(s_want_extra_isize);
2830 	APPLY(s_inode_readahead_blks);
2831 	APPLY(s_max_dir_size_kb);
2832 	APPLY(s_li_wait_mult);
2833 	APPLY(s_resgid);
2834 	APPLY(s_resuid);
2835 
2836 #ifdef CONFIG_EXT4_DEBUG
2837 	APPLY(s_fc_debug_max_replay);
2838 #endif
2839 
2840 	ext4_apply_quota_options(fc, sb);
2841 	ext4_apply_test_dummy_encryption(ctx, sb);
2842 }
2843 
2844 
2845 static int ext4_validate_options(struct fs_context *fc)
2846 {
2847 #ifdef CONFIG_QUOTA
2848 	struct ext4_fs_context *ctx = fc->fs_private;
2849 	char *usr_qf_name, *grp_qf_name;
2850 
2851 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2852 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2853 
2854 	if (usr_qf_name || grp_qf_name) {
2855 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2856 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2857 
2858 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2859 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2860 
2861 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2862 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2863 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2864 				 "format mixing");
2865 			return -EINVAL;
2866 		}
2867 	}
2868 #endif
2869 	return 1;
2870 }
2871 
2872 static inline void ext4_show_quota_options(struct seq_file *seq,
2873 					   struct super_block *sb)
2874 {
2875 #if defined(CONFIG_QUOTA)
2876 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2877 	char *usr_qf_name, *grp_qf_name;
2878 
2879 	if (sbi->s_jquota_fmt) {
2880 		char *fmtname = "";
2881 
2882 		switch (sbi->s_jquota_fmt) {
2883 		case QFMT_VFS_OLD:
2884 			fmtname = "vfsold";
2885 			break;
2886 		case QFMT_VFS_V0:
2887 			fmtname = "vfsv0";
2888 			break;
2889 		case QFMT_VFS_V1:
2890 			fmtname = "vfsv1";
2891 			break;
2892 		}
2893 		seq_printf(seq, ",jqfmt=%s", fmtname);
2894 	}
2895 
2896 	rcu_read_lock();
2897 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2898 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2899 	if (usr_qf_name)
2900 		seq_show_option(seq, "usrjquota", usr_qf_name);
2901 	if (grp_qf_name)
2902 		seq_show_option(seq, "grpjquota", grp_qf_name);
2903 	rcu_read_unlock();
2904 #endif
2905 }
2906 
2907 static const char *token2str(int token)
2908 {
2909 	const struct fs_parameter_spec *spec;
2910 
2911 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2912 		if (spec->opt == token && !spec->type)
2913 			break;
2914 	return spec->name;
2915 }
2916 
2917 /*
2918  * Show an option if
2919  *  - it's set to a non-default value OR
2920  *  - if the per-sb default is different from the global default
2921  */
2922 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2923 			      int nodefs)
2924 {
2925 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2926 	struct ext4_super_block *es = sbi->s_es;
2927 	int def_errors;
2928 	const struct mount_opts *m;
2929 	char sep = nodefs ? '\n' : ',';
2930 
2931 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2932 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2933 
2934 	if (sbi->s_sb_block != 1)
2935 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2936 
2937 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2938 		int want_set = m->flags & MOPT_SET;
2939 		int opt_2 = m->flags & MOPT_2;
2940 		unsigned int mount_opt, def_mount_opt;
2941 
2942 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2943 		    m->flags & MOPT_SKIP)
2944 			continue;
2945 
2946 		if (opt_2) {
2947 			mount_opt = sbi->s_mount_opt2;
2948 			def_mount_opt = sbi->s_def_mount_opt2;
2949 		} else {
2950 			mount_opt = sbi->s_mount_opt;
2951 			def_mount_opt = sbi->s_def_mount_opt;
2952 		}
2953 		/* skip if same as the default */
2954 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2955 			continue;
2956 		/* select Opt_noFoo vs Opt_Foo */
2957 		if ((want_set &&
2958 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2959 		    (!want_set && (mount_opt & m->mount_opt)))
2960 			continue;
2961 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2962 	}
2963 
2964 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2965 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2966 		SEQ_OPTS_PRINT("resuid=%u",
2967 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2968 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2969 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2970 		SEQ_OPTS_PRINT("resgid=%u",
2971 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2972 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2973 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2974 		SEQ_OPTS_PUTS("errors=remount-ro");
2975 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2976 		SEQ_OPTS_PUTS("errors=continue");
2977 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2978 		SEQ_OPTS_PUTS("errors=panic");
2979 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2980 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2981 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2982 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2983 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2984 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2985 	if (nodefs || sbi->s_stripe)
2986 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2987 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2988 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
2989 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2990 			SEQ_OPTS_PUTS("data=journal");
2991 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2992 			SEQ_OPTS_PUTS("data=ordered");
2993 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2994 			SEQ_OPTS_PUTS("data=writeback");
2995 	}
2996 	if (nodefs ||
2997 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2998 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2999 			       sbi->s_inode_readahead_blks);
3000 
3001 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3002 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3003 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3004 	if (nodefs || sbi->s_max_dir_size_kb)
3005 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3006 	if (test_opt(sb, DATA_ERR_ABORT))
3007 		SEQ_OPTS_PUTS("data_err=abort");
3008 
3009 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3010 
3011 	if (sb->s_flags & SB_INLINECRYPT)
3012 		SEQ_OPTS_PUTS("inlinecrypt");
3013 
3014 	if (test_opt(sb, DAX_ALWAYS)) {
3015 		if (IS_EXT2_SB(sb))
3016 			SEQ_OPTS_PUTS("dax");
3017 		else
3018 			SEQ_OPTS_PUTS("dax=always");
3019 	} else if (test_opt2(sb, DAX_NEVER)) {
3020 		SEQ_OPTS_PUTS("dax=never");
3021 	} else if (test_opt2(sb, DAX_INODE)) {
3022 		SEQ_OPTS_PUTS("dax=inode");
3023 	}
3024 
3025 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3026 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3027 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3028 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3029 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3030 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3031 	}
3032 
3033 	ext4_show_quota_options(seq, sb);
3034 	return 0;
3035 }
3036 
3037 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3038 {
3039 	return _ext4_show_options(seq, root->d_sb, 0);
3040 }
3041 
3042 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3043 {
3044 	struct super_block *sb = seq->private;
3045 	int rc;
3046 
3047 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3048 	rc = _ext4_show_options(seq, sb, 1);
3049 	seq_putc(seq, '\n');
3050 	return rc;
3051 }
3052 
3053 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3054 			    int read_only)
3055 {
3056 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3057 	int err = 0;
3058 
3059 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3060 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3061 			 "forcing read-only mode");
3062 		err = -EROFS;
3063 		goto done;
3064 	}
3065 	if (read_only)
3066 		goto done;
3067 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3068 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3069 			 "running e2fsck is recommended");
3070 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3071 		ext4_msg(sb, KERN_WARNING,
3072 			 "warning: mounting fs with errors, "
3073 			 "running e2fsck is recommended");
3074 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3075 		 le16_to_cpu(es->s_mnt_count) >=
3076 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3077 		ext4_msg(sb, KERN_WARNING,
3078 			 "warning: maximal mount count reached, "
3079 			 "running e2fsck is recommended");
3080 	else if (le32_to_cpu(es->s_checkinterval) &&
3081 		 (ext4_get_tstamp(es, s_lastcheck) +
3082 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3083 		ext4_msg(sb, KERN_WARNING,
3084 			 "warning: checktime reached, "
3085 			 "running e2fsck is recommended");
3086 	if (!sbi->s_journal)
3087 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3088 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3089 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3090 	le16_add_cpu(&es->s_mnt_count, 1);
3091 	ext4_update_tstamp(es, s_mtime);
3092 	if (sbi->s_journal) {
3093 		ext4_set_feature_journal_needs_recovery(sb);
3094 		if (ext4_has_feature_orphan_file(sb))
3095 			ext4_set_feature_orphan_present(sb);
3096 	}
3097 
3098 	err = ext4_commit_super(sb);
3099 done:
3100 	if (test_opt(sb, DEBUG))
3101 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3102 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3103 			sb->s_blocksize,
3104 			sbi->s_groups_count,
3105 			EXT4_BLOCKS_PER_GROUP(sb),
3106 			EXT4_INODES_PER_GROUP(sb),
3107 			sbi->s_mount_opt, sbi->s_mount_opt2);
3108 	return err;
3109 }
3110 
3111 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3112 {
3113 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3114 	struct flex_groups **old_groups, **new_groups;
3115 	int size, i, j;
3116 
3117 	if (!sbi->s_log_groups_per_flex)
3118 		return 0;
3119 
3120 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3121 	if (size <= sbi->s_flex_groups_allocated)
3122 		return 0;
3123 
3124 	new_groups = kvzalloc(roundup_pow_of_two(size *
3125 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3126 	if (!new_groups) {
3127 		ext4_msg(sb, KERN_ERR,
3128 			 "not enough memory for %d flex group pointers", size);
3129 		return -ENOMEM;
3130 	}
3131 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3132 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3133 					 sizeof(struct flex_groups)),
3134 					 GFP_KERNEL);
3135 		if (!new_groups[i]) {
3136 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3137 				kvfree(new_groups[j]);
3138 			kvfree(new_groups);
3139 			ext4_msg(sb, KERN_ERR,
3140 				 "not enough memory for %d flex groups", size);
3141 			return -ENOMEM;
3142 		}
3143 	}
3144 	rcu_read_lock();
3145 	old_groups = rcu_dereference(sbi->s_flex_groups);
3146 	if (old_groups)
3147 		memcpy(new_groups, old_groups,
3148 		       (sbi->s_flex_groups_allocated *
3149 			sizeof(struct flex_groups *)));
3150 	rcu_read_unlock();
3151 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3152 	sbi->s_flex_groups_allocated = size;
3153 	if (old_groups)
3154 		ext4_kvfree_array_rcu(old_groups);
3155 	return 0;
3156 }
3157 
3158 static int ext4_fill_flex_info(struct super_block *sb)
3159 {
3160 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3161 	struct ext4_group_desc *gdp = NULL;
3162 	struct flex_groups *fg;
3163 	ext4_group_t flex_group;
3164 	int i, err;
3165 
3166 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3167 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3168 		sbi->s_log_groups_per_flex = 0;
3169 		return 1;
3170 	}
3171 
3172 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3173 	if (err)
3174 		goto failed;
3175 
3176 	for (i = 0; i < sbi->s_groups_count; i++) {
3177 		gdp = ext4_get_group_desc(sb, i, NULL);
3178 
3179 		flex_group = ext4_flex_group(sbi, i);
3180 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3181 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3182 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3183 			     &fg->free_clusters);
3184 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3185 	}
3186 
3187 	return 1;
3188 failed:
3189 	return 0;
3190 }
3191 
3192 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3193 				   struct ext4_group_desc *gdp)
3194 {
3195 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3196 	__u16 crc = 0;
3197 	__le32 le_group = cpu_to_le32(block_group);
3198 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3199 
3200 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3201 		/* Use new metadata_csum algorithm */
3202 		__u32 csum32;
3203 		__u16 dummy_csum = 0;
3204 
3205 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3206 				     sizeof(le_group));
3207 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3208 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3209 				     sizeof(dummy_csum));
3210 		offset += sizeof(dummy_csum);
3211 		if (offset < sbi->s_desc_size)
3212 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3213 					     sbi->s_desc_size - offset);
3214 
3215 		crc = csum32 & 0xFFFF;
3216 		goto out;
3217 	}
3218 
3219 	/* old crc16 code */
3220 	if (!ext4_has_feature_gdt_csum(sb))
3221 		return 0;
3222 
3223 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3224 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3225 	crc = crc16(crc, (__u8 *)gdp, offset);
3226 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3227 	/* for checksum of struct ext4_group_desc do the rest...*/
3228 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3229 		crc = crc16(crc, (__u8 *)gdp + offset,
3230 			    sbi->s_desc_size - offset);
3231 
3232 out:
3233 	return cpu_to_le16(crc);
3234 }
3235 
3236 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3237 				struct ext4_group_desc *gdp)
3238 {
3239 	if (ext4_has_group_desc_csum(sb) &&
3240 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3241 		return 0;
3242 
3243 	return 1;
3244 }
3245 
3246 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3247 			      struct ext4_group_desc *gdp)
3248 {
3249 	if (!ext4_has_group_desc_csum(sb))
3250 		return;
3251 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3252 }
3253 
3254 /* Called at mount-time, super-block is locked */
3255 static int ext4_check_descriptors(struct super_block *sb,
3256 				  ext4_fsblk_t sb_block,
3257 				  ext4_group_t *first_not_zeroed)
3258 {
3259 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3260 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3261 	ext4_fsblk_t last_block;
3262 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3263 	ext4_fsblk_t block_bitmap;
3264 	ext4_fsblk_t inode_bitmap;
3265 	ext4_fsblk_t inode_table;
3266 	int flexbg_flag = 0;
3267 	ext4_group_t i, grp = sbi->s_groups_count;
3268 
3269 	if (ext4_has_feature_flex_bg(sb))
3270 		flexbg_flag = 1;
3271 
3272 	ext4_debug("Checking group descriptors");
3273 
3274 	for (i = 0; i < sbi->s_groups_count; i++) {
3275 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3276 
3277 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3278 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3279 		else
3280 			last_block = first_block +
3281 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3282 
3283 		if ((grp == sbi->s_groups_count) &&
3284 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3285 			grp = i;
3286 
3287 		block_bitmap = ext4_block_bitmap(sb, gdp);
3288 		if (block_bitmap == sb_block) {
3289 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3290 				 "Block bitmap for group %u overlaps "
3291 				 "superblock", i);
3292 			if (!sb_rdonly(sb))
3293 				return 0;
3294 		}
3295 		if (block_bitmap >= sb_block + 1 &&
3296 		    block_bitmap <= last_bg_block) {
3297 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3298 				 "Block bitmap for group %u overlaps "
3299 				 "block group descriptors", i);
3300 			if (!sb_rdonly(sb))
3301 				return 0;
3302 		}
3303 		if (block_bitmap < first_block || block_bitmap > last_block) {
3304 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3305 			       "Block bitmap for group %u not in group "
3306 			       "(block %llu)!", i, block_bitmap);
3307 			return 0;
3308 		}
3309 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3310 		if (inode_bitmap == sb_block) {
3311 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3312 				 "Inode bitmap for group %u overlaps "
3313 				 "superblock", i);
3314 			if (!sb_rdonly(sb))
3315 				return 0;
3316 		}
3317 		if (inode_bitmap >= sb_block + 1 &&
3318 		    inode_bitmap <= last_bg_block) {
3319 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3320 				 "Inode bitmap for group %u overlaps "
3321 				 "block group descriptors", i);
3322 			if (!sb_rdonly(sb))
3323 				return 0;
3324 		}
3325 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3326 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3327 			       "Inode bitmap for group %u not in group "
3328 			       "(block %llu)!", i, inode_bitmap);
3329 			return 0;
3330 		}
3331 		inode_table = ext4_inode_table(sb, gdp);
3332 		if (inode_table == sb_block) {
3333 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3334 				 "Inode table for group %u overlaps "
3335 				 "superblock", i);
3336 			if (!sb_rdonly(sb))
3337 				return 0;
3338 		}
3339 		if (inode_table >= sb_block + 1 &&
3340 		    inode_table <= last_bg_block) {
3341 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3342 				 "Inode table for group %u overlaps "
3343 				 "block group descriptors", i);
3344 			if (!sb_rdonly(sb))
3345 				return 0;
3346 		}
3347 		if (inode_table < first_block ||
3348 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3349 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3350 			       "Inode table for group %u not in group "
3351 			       "(block %llu)!", i, inode_table);
3352 			return 0;
3353 		}
3354 		ext4_lock_group(sb, i);
3355 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3356 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3357 				 "Checksum for group %u failed (%u!=%u)",
3358 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3359 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3360 			if (!sb_rdonly(sb)) {
3361 				ext4_unlock_group(sb, i);
3362 				return 0;
3363 			}
3364 		}
3365 		ext4_unlock_group(sb, i);
3366 		if (!flexbg_flag)
3367 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3368 	}
3369 	if (NULL != first_not_zeroed)
3370 		*first_not_zeroed = grp;
3371 	return 1;
3372 }
3373 
3374 /*
3375  * Maximal extent format file size.
3376  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3377  * extent format containers, within a sector_t, and within i_blocks
3378  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3379  * so that won't be a limiting factor.
3380  *
3381  * However there is other limiting factor. We do store extents in the form
3382  * of starting block and length, hence the resulting length of the extent
3383  * covering maximum file size must fit into on-disk format containers as
3384  * well. Given that length is always by 1 unit bigger than max unit (because
3385  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3386  *
3387  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3388  */
3389 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3390 {
3391 	loff_t res;
3392 	loff_t upper_limit = MAX_LFS_FILESIZE;
3393 
3394 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3395 
3396 	if (!has_huge_files) {
3397 		upper_limit = (1LL << 32) - 1;
3398 
3399 		/* total blocks in file system block size */
3400 		upper_limit >>= (blkbits - 9);
3401 		upper_limit <<= blkbits;
3402 	}
3403 
3404 	/*
3405 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3406 	 * by one fs block, so ee_len can cover the extent of maximum file
3407 	 * size
3408 	 */
3409 	res = (1LL << 32) - 1;
3410 	res <<= blkbits;
3411 
3412 	/* Sanity check against vm- & vfs- imposed limits */
3413 	if (res > upper_limit)
3414 		res = upper_limit;
3415 
3416 	return res;
3417 }
3418 
3419 /*
3420  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3421  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3422  * We need to be 1 filesystem block less than the 2^48 sector limit.
3423  */
3424 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3425 {
3426 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3427 	int meta_blocks;
3428 	unsigned int ppb = 1 << (bits - 2);
3429 
3430 	/*
3431 	 * This is calculated to be the largest file size for a dense, block
3432 	 * mapped file such that the file's total number of 512-byte sectors,
3433 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3434 	 *
3435 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3436 	 * number of 512-byte sectors of the file.
3437 	 */
3438 	if (!has_huge_files) {
3439 		/*
3440 		 * !has_huge_files or implies that the inode i_block field
3441 		 * represents total file blocks in 2^32 512-byte sectors ==
3442 		 * size of vfs inode i_blocks * 8
3443 		 */
3444 		upper_limit = (1LL << 32) - 1;
3445 
3446 		/* total blocks in file system block size */
3447 		upper_limit >>= (bits - 9);
3448 
3449 	} else {
3450 		/*
3451 		 * We use 48 bit ext4_inode i_blocks
3452 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3453 		 * represent total number of blocks in
3454 		 * file system block size
3455 		 */
3456 		upper_limit = (1LL << 48) - 1;
3457 
3458 	}
3459 
3460 	/* Compute how many blocks we can address by block tree */
3461 	res += ppb;
3462 	res += ppb * ppb;
3463 	res += ((loff_t)ppb) * ppb * ppb;
3464 	/* Compute how many metadata blocks are needed */
3465 	meta_blocks = 1;
3466 	meta_blocks += 1 + ppb;
3467 	meta_blocks += 1 + ppb + ppb * ppb;
3468 	/* Does block tree limit file size? */
3469 	if (res + meta_blocks <= upper_limit)
3470 		goto check_lfs;
3471 
3472 	res = upper_limit;
3473 	/* How many metadata blocks are needed for addressing upper_limit? */
3474 	upper_limit -= EXT4_NDIR_BLOCKS;
3475 	/* indirect blocks */
3476 	meta_blocks = 1;
3477 	upper_limit -= ppb;
3478 	/* double indirect blocks */
3479 	if (upper_limit < ppb * ppb) {
3480 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3481 		res -= meta_blocks;
3482 		goto check_lfs;
3483 	}
3484 	meta_blocks += 1 + ppb;
3485 	upper_limit -= ppb * ppb;
3486 	/* tripple indirect blocks for the rest */
3487 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3488 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3489 	res -= meta_blocks;
3490 check_lfs:
3491 	res <<= bits;
3492 	if (res > MAX_LFS_FILESIZE)
3493 		res = MAX_LFS_FILESIZE;
3494 
3495 	return res;
3496 }
3497 
3498 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3499 				   ext4_fsblk_t logical_sb_block, int nr)
3500 {
3501 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3502 	ext4_group_t bg, first_meta_bg;
3503 	int has_super = 0;
3504 
3505 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3506 
3507 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3508 		return logical_sb_block + nr + 1;
3509 	bg = sbi->s_desc_per_block * nr;
3510 	if (ext4_bg_has_super(sb, bg))
3511 		has_super = 1;
3512 
3513 	/*
3514 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3515 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3516 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3517 	 * compensate.
3518 	 */
3519 	if (sb->s_blocksize == 1024 && nr == 0 &&
3520 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3521 		has_super++;
3522 
3523 	return (has_super + ext4_group_first_block_no(sb, bg));
3524 }
3525 
3526 /**
3527  * ext4_get_stripe_size: Get the stripe size.
3528  * @sbi: In memory super block info
3529  *
3530  * If we have specified it via mount option, then
3531  * use the mount option value. If the value specified at mount time is
3532  * greater than the blocks per group use the super block value.
3533  * If the super block value is greater than blocks per group return 0.
3534  * Allocator needs it be less than blocks per group.
3535  *
3536  */
3537 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3538 {
3539 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3540 	unsigned long stripe_width =
3541 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3542 	int ret;
3543 
3544 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3545 		ret = sbi->s_stripe;
3546 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3547 		ret = stripe_width;
3548 	else if (stride && stride <= sbi->s_blocks_per_group)
3549 		ret = stride;
3550 	else
3551 		ret = 0;
3552 
3553 	/*
3554 	 * If the stripe width is 1, this makes no sense and
3555 	 * we set it to 0 to turn off stripe handling code.
3556 	 */
3557 	if (ret <= 1)
3558 		ret = 0;
3559 
3560 	return ret;
3561 }
3562 
3563 /*
3564  * Check whether this filesystem can be mounted based on
3565  * the features present and the RDONLY/RDWR mount requested.
3566  * Returns 1 if this filesystem can be mounted as requested,
3567  * 0 if it cannot be.
3568  */
3569 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3570 {
3571 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3572 		ext4_msg(sb, KERN_ERR,
3573 			"Couldn't mount because of "
3574 			"unsupported optional features (%x)",
3575 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3576 			~EXT4_FEATURE_INCOMPAT_SUPP));
3577 		return 0;
3578 	}
3579 
3580 	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
3581 		ext4_msg(sb, KERN_ERR,
3582 			 "Filesystem with casefold feature cannot be "
3583 			 "mounted without CONFIG_UNICODE");
3584 		return 0;
3585 	}
3586 
3587 	if (readonly)
3588 		return 1;
3589 
3590 	if (ext4_has_feature_readonly(sb)) {
3591 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3592 		sb->s_flags |= SB_RDONLY;
3593 		return 1;
3594 	}
3595 
3596 	/* Check that feature set is OK for a read-write mount */
3597 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3598 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3599 			 "unsupported optional features (%x)",
3600 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3601 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3602 		return 0;
3603 	}
3604 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3605 		ext4_msg(sb, KERN_ERR,
3606 			 "Can't support bigalloc feature without "
3607 			 "extents feature\n");
3608 		return 0;
3609 	}
3610 
3611 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3612 	if (!readonly && (ext4_has_feature_quota(sb) ||
3613 			  ext4_has_feature_project(sb))) {
3614 		ext4_msg(sb, KERN_ERR,
3615 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3616 		return 0;
3617 	}
3618 #endif  /* CONFIG_QUOTA */
3619 	return 1;
3620 }
3621 
3622 /*
3623  * This function is called once a day if we have errors logged
3624  * on the file system
3625  */
3626 static void print_daily_error_info(struct timer_list *t)
3627 {
3628 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3629 	struct super_block *sb = sbi->s_sb;
3630 	struct ext4_super_block *es = sbi->s_es;
3631 
3632 	if (es->s_error_count)
3633 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3634 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3635 			 le32_to_cpu(es->s_error_count));
3636 	if (es->s_first_error_time) {
3637 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3638 		       sb->s_id,
3639 		       ext4_get_tstamp(es, s_first_error_time),
3640 		       (int) sizeof(es->s_first_error_func),
3641 		       es->s_first_error_func,
3642 		       le32_to_cpu(es->s_first_error_line));
3643 		if (es->s_first_error_ino)
3644 			printk(KERN_CONT ": inode %u",
3645 			       le32_to_cpu(es->s_first_error_ino));
3646 		if (es->s_first_error_block)
3647 			printk(KERN_CONT ": block %llu", (unsigned long long)
3648 			       le64_to_cpu(es->s_first_error_block));
3649 		printk(KERN_CONT "\n");
3650 	}
3651 	if (es->s_last_error_time) {
3652 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3653 		       sb->s_id,
3654 		       ext4_get_tstamp(es, s_last_error_time),
3655 		       (int) sizeof(es->s_last_error_func),
3656 		       es->s_last_error_func,
3657 		       le32_to_cpu(es->s_last_error_line));
3658 		if (es->s_last_error_ino)
3659 			printk(KERN_CONT ": inode %u",
3660 			       le32_to_cpu(es->s_last_error_ino));
3661 		if (es->s_last_error_block)
3662 			printk(KERN_CONT ": block %llu", (unsigned long long)
3663 			       le64_to_cpu(es->s_last_error_block));
3664 		printk(KERN_CONT "\n");
3665 	}
3666 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3667 }
3668 
3669 /* Find next suitable group and run ext4_init_inode_table */
3670 static int ext4_run_li_request(struct ext4_li_request *elr)
3671 {
3672 	struct ext4_group_desc *gdp = NULL;
3673 	struct super_block *sb = elr->lr_super;
3674 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3675 	ext4_group_t group = elr->lr_next_group;
3676 	unsigned int prefetch_ios = 0;
3677 	int ret = 0;
3678 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3679 	u64 start_time;
3680 
3681 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3682 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3683 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3684 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3685 		if (group >= elr->lr_next_group) {
3686 			ret = 1;
3687 			if (elr->lr_first_not_zeroed != ngroups &&
3688 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3689 				elr->lr_next_group = elr->lr_first_not_zeroed;
3690 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3691 				ret = 0;
3692 			}
3693 		}
3694 		return ret;
3695 	}
3696 
3697 	for (; group < ngroups; group++) {
3698 		gdp = ext4_get_group_desc(sb, group, NULL);
3699 		if (!gdp) {
3700 			ret = 1;
3701 			break;
3702 		}
3703 
3704 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3705 			break;
3706 	}
3707 
3708 	if (group >= ngroups)
3709 		ret = 1;
3710 
3711 	if (!ret) {
3712 		start_time = ktime_get_real_ns();
3713 		ret = ext4_init_inode_table(sb, group,
3714 					    elr->lr_timeout ? 0 : 1);
3715 		trace_ext4_lazy_itable_init(sb, group);
3716 		if (elr->lr_timeout == 0) {
3717 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3718 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3719 		}
3720 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3721 		elr->lr_next_group = group + 1;
3722 	}
3723 	return ret;
3724 }
3725 
3726 /*
3727  * Remove lr_request from the list_request and free the
3728  * request structure. Should be called with li_list_mtx held
3729  */
3730 static void ext4_remove_li_request(struct ext4_li_request *elr)
3731 {
3732 	if (!elr)
3733 		return;
3734 
3735 	list_del(&elr->lr_request);
3736 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3737 	kfree(elr);
3738 }
3739 
3740 static void ext4_unregister_li_request(struct super_block *sb)
3741 {
3742 	mutex_lock(&ext4_li_mtx);
3743 	if (!ext4_li_info) {
3744 		mutex_unlock(&ext4_li_mtx);
3745 		return;
3746 	}
3747 
3748 	mutex_lock(&ext4_li_info->li_list_mtx);
3749 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3750 	mutex_unlock(&ext4_li_info->li_list_mtx);
3751 	mutex_unlock(&ext4_li_mtx);
3752 }
3753 
3754 static struct task_struct *ext4_lazyinit_task;
3755 
3756 /*
3757  * This is the function where ext4lazyinit thread lives. It walks
3758  * through the request list searching for next scheduled filesystem.
3759  * When such a fs is found, run the lazy initialization request
3760  * (ext4_rn_li_request) and keep track of the time spend in this
3761  * function. Based on that time we compute next schedule time of
3762  * the request. When walking through the list is complete, compute
3763  * next waking time and put itself into sleep.
3764  */
3765 static int ext4_lazyinit_thread(void *arg)
3766 {
3767 	struct ext4_lazy_init *eli = arg;
3768 	struct list_head *pos, *n;
3769 	struct ext4_li_request *elr;
3770 	unsigned long next_wakeup, cur;
3771 
3772 	BUG_ON(NULL == eli);
3773 	set_freezable();
3774 
3775 cont_thread:
3776 	while (true) {
3777 		next_wakeup = MAX_JIFFY_OFFSET;
3778 
3779 		mutex_lock(&eli->li_list_mtx);
3780 		if (list_empty(&eli->li_request_list)) {
3781 			mutex_unlock(&eli->li_list_mtx);
3782 			goto exit_thread;
3783 		}
3784 		list_for_each_safe(pos, n, &eli->li_request_list) {
3785 			int err = 0;
3786 			int progress = 0;
3787 			elr = list_entry(pos, struct ext4_li_request,
3788 					 lr_request);
3789 
3790 			if (time_before(jiffies, elr->lr_next_sched)) {
3791 				if (time_before(elr->lr_next_sched, next_wakeup))
3792 					next_wakeup = elr->lr_next_sched;
3793 				continue;
3794 			}
3795 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3796 				if (sb_start_write_trylock(elr->lr_super)) {
3797 					progress = 1;
3798 					/*
3799 					 * We hold sb->s_umount, sb can not
3800 					 * be removed from the list, it is
3801 					 * now safe to drop li_list_mtx
3802 					 */
3803 					mutex_unlock(&eli->li_list_mtx);
3804 					err = ext4_run_li_request(elr);
3805 					sb_end_write(elr->lr_super);
3806 					mutex_lock(&eli->li_list_mtx);
3807 					n = pos->next;
3808 				}
3809 				up_read((&elr->lr_super->s_umount));
3810 			}
3811 			/* error, remove the lazy_init job */
3812 			if (err) {
3813 				ext4_remove_li_request(elr);
3814 				continue;
3815 			}
3816 			if (!progress) {
3817 				elr->lr_next_sched = jiffies +
3818 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3819 			}
3820 			if (time_before(elr->lr_next_sched, next_wakeup))
3821 				next_wakeup = elr->lr_next_sched;
3822 		}
3823 		mutex_unlock(&eli->li_list_mtx);
3824 
3825 		try_to_freeze();
3826 
3827 		cur = jiffies;
3828 		if ((time_after_eq(cur, next_wakeup)) ||
3829 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3830 			cond_resched();
3831 			continue;
3832 		}
3833 
3834 		schedule_timeout_interruptible(next_wakeup - cur);
3835 
3836 		if (kthread_should_stop()) {
3837 			ext4_clear_request_list();
3838 			goto exit_thread;
3839 		}
3840 	}
3841 
3842 exit_thread:
3843 	/*
3844 	 * It looks like the request list is empty, but we need
3845 	 * to check it under the li_list_mtx lock, to prevent any
3846 	 * additions into it, and of course we should lock ext4_li_mtx
3847 	 * to atomically free the list and ext4_li_info, because at
3848 	 * this point another ext4 filesystem could be registering
3849 	 * new one.
3850 	 */
3851 	mutex_lock(&ext4_li_mtx);
3852 	mutex_lock(&eli->li_list_mtx);
3853 	if (!list_empty(&eli->li_request_list)) {
3854 		mutex_unlock(&eli->li_list_mtx);
3855 		mutex_unlock(&ext4_li_mtx);
3856 		goto cont_thread;
3857 	}
3858 	mutex_unlock(&eli->li_list_mtx);
3859 	kfree(ext4_li_info);
3860 	ext4_li_info = NULL;
3861 	mutex_unlock(&ext4_li_mtx);
3862 
3863 	return 0;
3864 }
3865 
3866 static void ext4_clear_request_list(void)
3867 {
3868 	struct list_head *pos, *n;
3869 	struct ext4_li_request *elr;
3870 
3871 	mutex_lock(&ext4_li_info->li_list_mtx);
3872 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3873 		elr = list_entry(pos, struct ext4_li_request,
3874 				 lr_request);
3875 		ext4_remove_li_request(elr);
3876 	}
3877 	mutex_unlock(&ext4_li_info->li_list_mtx);
3878 }
3879 
3880 static int ext4_run_lazyinit_thread(void)
3881 {
3882 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3883 					 ext4_li_info, "ext4lazyinit");
3884 	if (IS_ERR(ext4_lazyinit_task)) {
3885 		int err = PTR_ERR(ext4_lazyinit_task);
3886 		ext4_clear_request_list();
3887 		kfree(ext4_li_info);
3888 		ext4_li_info = NULL;
3889 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3890 				 "initialization thread\n",
3891 				 err);
3892 		return err;
3893 	}
3894 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3895 	return 0;
3896 }
3897 
3898 /*
3899  * Check whether it make sense to run itable init. thread or not.
3900  * If there is at least one uninitialized inode table, return
3901  * corresponding group number, else the loop goes through all
3902  * groups and return total number of groups.
3903  */
3904 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3905 {
3906 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3907 	struct ext4_group_desc *gdp = NULL;
3908 
3909 	if (!ext4_has_group_desc_csum(sb))
3910 		return ngroups;
3911 
3912 	for (group = 0; group < ngroups; group++) {
3913 		gdp = ext4_get_group_desc(sb, group, NULL);
3914 		if (!gdp)
3915 			continue;
3916 
3917 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3918 			break;
3919 	}
3920 
3921 	return group;
3922 }
3923 
3924 static int ext4_li_info_new(void)
3925 {
3926 	struct ext4_lazy_init *eli = NULL;
3927 
3928 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3929 	if (!eli)
3930 		return -ENOMEM;
3931 
3932 	INIT_LIST_HEAD(&eli->li_request_list);
3933 	mutex_init(&eli->li_list_mtx);
3934 
3935 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3936 
3937 	ext4_li_info = eli;
3938 
3939 	return 0;
3940 }
3941 
3942 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3943 					    ext4_group_t start)
3944 {
3945 	struct ext4_li_request *elr;
3946 
3947 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3948 	if (!elr)
3949 		return NULL;
3950 
3951 	elr->lr_super = sb;
3952 	elr->lr_first_not_zeroed = start;
3953 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3954 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3955 		elr->lr_next_group = start;
3956 	} else {
3957 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3958 	}
3959 
3960 	/*
3961 	 * Randomize first schedule time of the request to
3962 	 * spread the inode table initialization requests
3963 	 * better.
3964 	 */
3965 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3966 	return elr;
3967 }
3968 
3969 int ext4_register_li_request(struct super_block *sb,
3970 			     ext4_group_t first_not_zeroed)
3971 {
3972 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3973 	struct ext4_li_request *elr = NULL;
3974 	ext4_group_t ngroups = sbi->s_groups_count;
3975 	int ret = 0;
3976 
3977 	mutex_lock(&ext4_li_mtx);
3978 	if (sbi->s_li_request != NULL) {
3979 		/*
3980 		 * Reset timeout so it can be computed again, because
3981 		 * s_li_wait_mult might have changed.
3982 		 */
3983 		sbi->s_li_request->lr_timeout = 0;
3984 		goto out;
3985 	}
3986 
3987 	if (sb_rdonly(sb) ||
3988 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3989 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
3990 		goto out;
3991 
3992 	elr = ext4_li_request_new(sb, first_not_zeroed);
3993 	if (!elr) {
3994 		ret = -ENOMEM;
3995 		goto out;
3996 	}
3997 
3998 	if (NULL == ext4_li_info) {
3999 		ret = ext4_li_info_new();
4000 		if (ret)
4001 			goto out;
4002 	}
4003 
4004 	mutex_lock(&ext4_li_info->li_list_mtx);
4005 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4006 	mutex_unlock(&ext4_li_info->li_list_mtx);
4007 
4008 	sbi->s_li_request = elr;
4009 	/*
4010 	 * set elr to NULL here since it has been inserted to
4011 	 * the request_list and the removal and free of it is
4012 	 * handled by ext4_clear_request_list from now on.
4013 	 */
4014 	elr = NULL;
4015 
4016 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4017 		ret = ext4_run_lazyinit_thread();
4018 		if (ret)
4019 			goto out;
4020 	}
4021 out:
4022 	mutex_unlock(&ext4_li_mtx);
4023 	if (ret)
4024 		kfree(elr);
4025 	return ret;
4026 }
4027 
4028 /*
4029  * We do not need to lock anything since this is called on
4030  * module unload.
4031  */
4032 static void ext4_destroy_lazyinit_thread(void)
4033 {
4034 	/*
4035 	 * If thread exited earlier
4036 	 * there's nothing to be done.
4037 	 */
4038 	if (!ext4_li_info || !ext4_lazyinit_task)
4039 		return;
4040 
4041 	kthread_stop(ext4_lazyinit_task);
4042 }
4043 
4044 static int set_journal_csum_feature_set(struct super_block *sb)
4045 {
4046 	int ret = 1;
4047 	int compat, incompat;
4048 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4049 
4050 	if (ext4_has_metadata_csum(sb)) {
4051 		/* journal checksum v3 */
4052 		compat = 0;
4053 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4054 	} else {
4055 		/* journal checksum v1 */
4056 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4057 		incompat = 0;
4058 	}
4059 
4060 	jbd2_journal_clear_features(sbi->s_journal,
4061 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4062 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4063 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4064 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4065 		ret = jbd2_journal_set_features(sbi->s_journal,
4066 				compat, 0,
4067 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4068 				incompat);
4069 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4070 		ret = jbd2_journal_set_features(sbi->s_journal,
4071 				compat, 0,
4072 				incompat);
4073 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4074 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4075 	} else {
4076 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4077 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4078 	}
4079 
4080 	return ret;
4081 }
4082 
4083 /*
4084  * Note: calculating the overhead so we can be compatible with
4085  * historical BSD practice is quite difficult in the face of
4086  * clusters/bigalloc.  This is because multiple metadata blocks from
4087  * different block group can end up in the same allocation cluster.
4088  * Calculating the exact overhead in the face of clustered allocation
4089  * requires either O(all block bitmaps) in memory or O(number of block
4090  * groups**2) in time.  We will still calculate the superblock for
4091  * older file systems --- and if we come across with a bigalloc file
4092  * system with zero in s_overhead_clusters the estimate will be close to
4093  * correct especially for very large cluster sizes --- but for newer
4094  * file systems, it's better to calculate this figure once at mkfs
4095  * time, and store it in the superblock.  If the superblock value is
4096  * present (even for non-bigalloc file systems), we will use it.
4097  */
4098 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4099 			  char *buf)
4100 {
4101 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4102 	struct ext4_group_desc	*gdp;
4103 	ext4_fsblk_t		first_block, last_block, b;
4104 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4105 	int			s, j, count = 0;
4106 	int			has_super = ext4_bg_has_super(sb, grp);
4107 
4108 	if (!ext4_has_feature_bigalloc(sb))
4109 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4110 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4111 			sbi->s_itb_per_group + 2);
4112 
4113 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4114 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4115 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4116 	for (i = 0; i < ngroups; i++) {
4117 		gdp = ext4_get_group_desc(sb, i, NULL);
4118 		b = ext4_block_bitmap(sb, gdp);
4119 		if (b >= first_block && b <= last_block) {
4120 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4121 			count++;
4122 		}
4123 		b = ext4_inode_bitmap(sb, gdp);
4124 		if (b >= first_block && b <= last_block) {
4125 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4126 			count++;
4127 		}
4128 		b = ext4_inode_table(sb, gdp);
4129 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4130 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4131 				int c = EXT4_B2C(sbi, b - first_block);
4132 				ext4_set_bit(c, buf);
4133 				count++;
4134 			}
4135 		if (i != grp)
4136 			continue;
4137 		s = 0;
4138 		if (ext4_bg_has_super(sb, grp)) {
4139 			ext4_set_bit(s++, buf);
4140 			count++;
4141 		}
4142 		j = ext4_bg_num_gdb(sb, grp);
4143 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4144 			ext4_error(sb, "Invalid number of block group "
4145 				   "descriptor blocks: %d", j);
4146 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4147 		}
4148 		count += j;
4149 		for (; j > 0; j--)
4150 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4151 	}
4152 	if (!count)
4153 		return 0;
4154 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4155 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4156 }
4157 
4158 /*
4159  * Compute the overhead and stash it in sbi->s_overhead
4160  */
4161 int ext4_calculate_overhead(struct super_block *sb)
4162 {
4163 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4164 	struct ext4_super_block *es = sbi->s_es;
4165 	struct inode *j_inode;
4166 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4167 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4168 	ext4_fsblk_t overhead = 0;
4169 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4170 
4171 	if (!buf)
4172 		return -ENOMEM;
4173 
4174 	/*
4175 	 * Compute the overhead (FS structures).  This is constant
4176 	 * for a given filesystem unless the number of block groups
4177 	 * changes so we cache the previous value until it does.
4178 	 */
4179 
4180 	/*
4181 	 * All of the blocks before first_data_block are overhead
4182 	 */
4183 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4184 
4185 	/*
4186 	 * Add the overhead found in each block group
4187 	 */
4188 	for (i = 0; i < ngroups; i++) {
4189 		int blks;
4190 
4191 		blks = count_overhead(sb, i, buf);
4192 		overhead += blks;
4193 		if (blks)
4194 			memset(buf, 0, PAGE_SIZE);
4195 		cond_resched();
4196 	}
4197 
4198 	/*
4199 	 * Add the internal journal blocks whether the journal has been
4200 	 * loaded or not
4201 	 */
4202 	if (sbi->s_journal && !sbi->s_journal_bdev_file)
4203 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4204 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4205 		/* j_inum for internal journal is non-zero */
4206 		j_inode = ext4_get_journal_inode(sb, j_inum);
4207 		if (!IS_ERR(j_inode)) {
4208 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4209 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4210 			iput(j_inode);
4211 		} else {
4212 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4213 		}
4214 	}
4215 	sbi->s_overhead = overhead;
4216 	smp_wmb();
4217 	free_page((unsigned long) buf);
4218 	return 0;
4219 }
4220 
4221 static void ext4_set_resv_clusters(struct super_block *sb)
4222 {
4223 	ext4_fsblk_t resv_clusters;
4224 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4225 
4226 	/*
4227 	 * There's no need to reserve anything when we aren't using extents.
4228 	 * The space estimates are exact, there are no unwritten extents,
4229 	 * hole punching doesn't need new metadata... This is needed especially
4230 	 * to keep ext2/3 backward compatibility.
4231 	 */
4232 	if (!ext4_has_feature_extents(sb))
4233 		return;
4234 	/*
4235 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4236 	 * This should cover the situations where we can not afford to run
4237 	 * out of space like for example punch hole, or converting
4238 	 * unwritten extents in delalloc path. In most cases such
4239 	 * allocation would require 1, or 2 blocks, higher numbers are
4240 	 * very rare.
4241 	 */
4242 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4243 			 sbi->s_cluster_bits);
4244 
4245 	do_div(resv_clusters, 50);
4246 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4247 
4248 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4249 }
4250 
4251 static const char *ext4_quota_mode(struct super_block *sb)
4252 {
4253 #ifdef CONFIG_QUOTA
4254 	if (!ext4_quota_capable(sb))
4255 		return "none";
4256 
4257 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4258 		return "journalled";
4259 	else
4260 		return "writeback";
4261 #else
4262 	return "disabled";
4263 #endif
4264 }
4265 
4266 static void ext4_setup_csum_trigger(struct super_block *sb,
4267 				    enum ext4_journal_trigger_type type,
4268 				    void (*trigger)(
4269 					struct jbd2_buffer_trigger_type *type,
4270 					struct buffer_head *bh,
4271 					void *mapped_data,
4272 					size_t size))
4273 {
4274 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4275 
4276 	sbi->s_journal_triggers[type].sb = sb;
4277 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4278 }
4279 
4280 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4281 {
4282 	if (!sbi)
4283 		return;
4284 
4285 	kfree(sbi->s_blockgroup_lock);
4286 	fs_put_dax(sbi->s_daxdev, NULL);
4287 	kfree(sbi);
4288 }
4289 
4290 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4291 {
4292 	struct ext4_sb_info *sbi;
4293 
4294 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4295 	if (!sbi)
4296 		return NULL;
4297 
4298 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4299 					   NULL, NULL);
4300 
4301 	sbi->s_blockgroup_lock =
4302 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4303 
4304 	if (!sbi->s_blockgroup_lock)
4305 		goto err_out;
4306 
4307 	sb->s_fs_info = sbi;
4308 	sbi->s_sb = sb;
4309 	return sbi;
4310 err_out:
4311 	fs_put_dax(sbi->s_daxdev, NULL);
4312 	kfree(sbi);
4313 	return NULL;
4314 }
4315 
4316 static void ext4_set_def_opts(struct super_block *sb,
4317 			      struct ext4_super_block *es)
4318 {
4319 	unsigned long def_mount_opts;
4320 
4321 	/* Set defaults before we parse the mount options */
4322 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4323 	set_opt(sb, INIT_INODE_TABLE);
4324 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4325 		set_opt(sb, DEBUG);
4326 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4327 		set_opt(sb, GRPID);
4328 	if (def_mount_opts & EXT4_DEFM_UID16)
4329 		set_opt(sb, NO_UID32);
4330 	/* xattr user namespace & acls are now defaulted on */
4331 	set_opt(sb, XATTR_USER);
4332 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4333 	set_opt(sb, POSIX_ACL);
4334 #endif
4335 	if (ext4_has_feature_fast_commit(sb))
4336 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4337 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4338 	if (ext4_has_metadata_csum(sb))
4339 		set_opt(sb, JOURNAL_CHECKSUM);
4340 
4341 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4342 		set_opt(sb, JOURNAL_DATA);
4343 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4344 		set_opt(sb, ORDERED_DATA);
4345 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4346 		set_opt(sb, WRITEBACK_DATA);
4347 
4348 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4349 		set_opt(sb, ERRORS_PANIC);
4350 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4351 		set_opt(sb, ERRORS_CONT);
4352 	else
4353 		set_opt(sb, ERRORS_RO);
4354 	/* block_validity enabled by default; disable with noblock_validity */
4355 	set_opt(sb, BLOCK_VALIDITY);
4356 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4357 		set_opt(sb, DISCARD);
4358 
4359 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4360 		set_opt(sb, BARRIER);
4361 
4362 	/*
4363 	 * enable delayed allocation by default
4364 	 * Use -o nodelalloc to turn it off
4365 	 */
4366 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4367 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4368 		set_opt(sb, DELALLOC);
4369 
4370 	if (sb->s_blocksize <= PAGE_SIZE)
4371 		set_opt(sb, DIOREAD_NOLOCK);
4372 }
4373 
4374 static int ext4_handle_clustersize(struct super_block *sb)
4375 {
4376 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4377 	struct ext4_super_block *es = sbi->s_es;
4378 	int clustersize;
4379 
4380 	/* Handle clustersize */
4381 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4382 	if (ext4_has_feature_bigalloc(sb)) {
4383 		if (clustersize < sb->s_blocksize) {
4384 			ext4_msg(sb, KERN_ERR,
4385 				 "cluster size (%d) smaller than "
4386 				 "block size (%lu)", clustersize, sb->s_blocksize);
4387 			return -EINVAL;
4388 		}
4389 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4390 			le32_to_cpu(es->s_log_block_size);
4391 	} else {
4392 		if (clustersize != sb->s_blocksize) {
4393 			ext4_msg(sb, KERN_ERR,
4394 				 "fragment/cluster size (%d) != "
4395 				 "block size (%lu)", clustersize, sb->s_blocksize);
4396 			return -EINVAL;
4397 		}
4398 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4399 			ext4_msg(sb, KERN_ERR,
4400 				 "#blocks per group too big: %lu",
4401 				 sbi->s_blocks_per_group);
4402 			return -EINVAL;
4403 		}
4404 		sbi->s_cluster_bits = 0;
4405 	}
4406 	sbi->s_clusters_per_group = le32_to_cpu(es->s_clusters_per_group);
4407 	if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4408 		ext4_msg(sb, KERN_ERR, "#clusters per group too big: %lu",
4409 			 sbi->s_clusters_per_group);
4410 		return -EINVAL;
4411 	}
4412 	if (sbi->s_blocks_per_group !=
4413 	    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4414 		ext4_msg(sb, KERN_ERR,
4415 			 "blocks per group (%lu) and clusters per group (%lu) inconsistent",
4416 			 sbi->s_blocks_per_group, sbi->s_clusters_per_group);
4417 		return -EINVAL;
4418 	}
4419 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4420 
4421 	/* Do we have standard group size of clustersize * 8 blocks ? */
4422 	if (sbi->s_blocks_per_group == clustersize << 3)
4423 		set_opt2(sb, STD_GROUP_SIZE);
4424 
4425 	return 0;
4426 }
4427 
4428 static void ext4_fast_commit_init(struct super_block *sb)
4429 {
4430 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4431 
4432 	/* Initialize fast commit stuff */
4433 	atomic_set(&sbi->s_fc_subtid, 0);
4434 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4435 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4436 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4437 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4438 	sbi->s_fc_bytes = 0;
4439 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4440 	sbi->s_fc_ineligible_tid = 0;
4441 	spin_lock_init(&sbi->s_fc_lock);
4442 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4443 	sbi->s_fc_replay_state.fc_regions = NULL;
4444 	sbi->s_fc_replay_state.fc_regions_size = 0;
4445 	sbi->s_fc_replay_state.fc_regions_used = 0;
4446 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4447 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4448 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4449 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4450 }
4451 
4452 static int ext4_inode_info_init(struct super_block *sb,
4453 				struct ext4_super_block *es)
4454 {
4455 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4456 
4457 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4458 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4459 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4460 	} else {
4461 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4462 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4463 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4464 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4465 				 sbi->s_first_ino);
4466 			return -EINVAL;
4467 		}
4468 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4469 		    (!is_power_of_2(sbi->s_inode_size)) ||
4470 		    (sbi->s_inode_size > sb->s_blocksize)) {
4471 			ext4_msg(sb, KERN_ERR,
4472 			       "unsupported inode size: %d",
4473 			       sbi->s_inode_size);
4474 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4475 			return -EINVAL;
4476 		}
4477 		/*
4478 		 * i_atime_extra is the last extra field available for
4479 		 * [acm]times in struct ext4_inode. Checking for that
4480 		 * field should suffice to ensure we have extra space
4481 		 * for all three.
4482 		 */
4483 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4484 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4485 			sb->s_time_gran = 1;
4486 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4487 		} else {
4488 			sb->s_time_gran = NSEC_PER_SEC;
4489 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4490 		}
4491 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4492 	}
4493 
4494 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4495 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4496 			EXT4_GOOD_OLD_INODE_SIZE;
4497 		if (ext4_has_feature_extra_isize(sb)) {
4498 			unsigned v, max = (sbi->s_inode_size -
4499 					   EXT4_GOOD_OLD_INODE_SIZE);
4500 
4501 			v = le16_to_cpu(es->s_want_extra_isize);
4502 			if (v > max) {
4503 				ext4_msg(sb, KERN_ERR,
4504 					 "bad s_want_extra_isize: %d", v);
4505 				return -EINVAL;
4506 			}
4507 			if (sbi->s_want_extra_isize < v)
4508 				sbi->s_want_extra_isize = v;
4509 
4510 			v = le16_to_cpu(es->s_min_extra_isize);
4511 			if (v > max) {
4512 				ext4_msg(sb, KERN_ERR,
4513 					 "bad s_min_extra_isize: %d", v);
4514 				return -EINVAL;
4515 			}
4516 			if (sbi->s_want_extra_isize < v)
4517 				sbi->s_want_extra_isize = v;
4518 		}
4519 	}
4520 
4521 	return 0;
4522 }
4523 
4524 #if IS_ENABLED(CONFIG_UNICODE)
4525 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4526 {
4527 	const struct ext4_sb_encodings *encoding_info;
4528 	struct unicode_map *encoding;
4529 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4530 
4531 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4532 		return 0;
4533 
4534 	encoding_info = ext4_sb_read_encoding(es);
4535 	if (!encoding_info) {
4536 		ext4_msg(sb, KERN_ERR,
4537 			"Encoding requested by superblock is unknown");
4538 		return -EINVAL;
4539 	}
4540 
4541 	encoding = utf8_load(encoding_info->version);
4542 	if (IS_ERR(encoding)) {
4543 		ext4_msg(sb, KERN_ERR,
4544 			"can't mount with superblock charset: %s-%u.%u.%u "
4545 			"not supported by the kernel. flags: 0x%x.",
4546 			encoding_info->name,
4547 			unicode_major(encoding_info->version),
4548 			unicode_minor(encoding_info->version),
4549 			unicode_rev(encoding_info->version),
4550 			encoding_flags);
4551 		return -EINVAL;
4552 	}
4553 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4554 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4555 		unicode_major(encoding_info->version),
4556 		unicode_minor(encoding_info->version),
4557 		unicode_rev(encoding_info->version),
4558 		encoding_flags);
4559 
4560 	sb->s_encoding = encoding;
4561 	sb->s_encoding_flags = encoding_flags;
4562 
4563 	return 0;
4564 }
4565 #else
4566 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4567 {
4568 	return 0;
4569 }
4570 #endif
4571 
4572 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4573 {
4574 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4575 
4576 	/* Warn if metadata_csum and gdt_csum are both set. */
4577 	if (ext4_has_feature_metadata_csum(sb) &&
4578 	    ext4_has_feature_gdt_csum(sb))
4579 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4580 			     "redundant flags; please run fsck.");
4581 
4582 	/* Check for a known checksum algorithm */
4583 	if (!ext4_verify_csum_type(sb, es)) {
4584 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4585 			 "unknown checksum algorithm.");
4586 		return -EINVAL;
4587 	}
4588 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4589 				ext4_orphan_file_block_trigger);
4590 
4591 	/* Load the checksum driver */
4592 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4593 	if (IS_ERR(sbi->s_chksum_driver)) {
4594 		int ret = PTR_ERR(sbi->s_chksum_driver);
4595 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4596 		sbi->s_chksum_driver = NULL;
4597 		return ret;
4598 	}
4599 
4600 	/* Check superblock checksum */
4601 	if (!ext4_superblock_csum_verify(sb, es)) {
4602 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4603 			 "invalid superblock checksum.  Run e2fsck?");
4604 		return -EFSBADCRC;
4605 	}
4606 
4607 	/* Precompute checksum seed for all metadata */
4608 	if (ext4_has_feature_csum_seed(sb))
4609 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4610 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4611 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4612 					       sizeof(es->s_uuid));
4613 	return 0;
4614 }
4615 
4616 static int ext4_check_feature_compatibility(struct super_block *sb,
4617 					    struct ext4_super_block *es,
4618 					    int silent)
4619 {
4620 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4621 
4622 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4623 	    (ext4_has_compat_features(sb) ||
4624 	     ext4_has_ro_compat_features(sb) ||
4625 	     ext4_has_incompat_features(sb)))
4626 		ext4_msg(sb, KERN_WARNING,
4627 		       "feature flags set on rev 0 fs, "
4628 		       "running e2fsck is recommended");
4629 
4630 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4631 		set_opt2(sb, HURD_COMPAT);
4632 		if (ext4_has_feature_64bit(sb)) {
4633 			ext4_msg(sb, KERN_ERR,
4634 				 "The Hurd can't support 64-bit file systems");
4635 			return -EINVAL;
4636 		}
4637 
4638 		/*
4639 		 * ea_inode feature uses l_i_version field which is not
4640 		 * available in HURD_COMPAT mode.
4641 		 */
4642 		if (ext4_has_feature_ea_inode(sb)) {
4643 			ext4_msg(sb, KERN_ERR,
4644 				 "ea_inode feature is not supported for Hurd");
4645 			return -EINVAL;
4646 		}
4647 	}
4648 
4649 	if (IS_EXT2_SB(sb)) {
4650 		if (ext2_feature_set_ok(sb))
4651 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4652 				 "using the ext4 subsystem");
4653 		else {
4654 			/*
4655 			 * If we're probing be silent, if this looks like
4656 			 * it's actually an ext[34] filesystem.
4657 			 */
4658 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4659 				return -EINVAL;
4660 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4661 				 "to feature incompatibilities");
4662 			return -EINVAL;
4663 		}
4664 	}
4665 
4666 	if (IS_EXT3_SB(sb)) {
4667 		if (ext3_feature_set_ok(sb))
4668 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4669 				 "using the ext4 subsystem");
4670 		else {
4671 			/*
4672 			 * If we're probing be silent, if this looks like
4673 			 * it's actually an ext4 filesystem.
4674 			 */
4675 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4676 				return -EINVAL;
4677 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4678 				 "to feature incompatibilities");
4679 			return -EINVAL;
4680 		}
4681 	}
4682 
4683 	/*
4684 	 * Check feature flags regardless of the revision level, since we
4685 	 * previously didn't change the revision level when setting the flags,
4686 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4687 	 */
4688 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4689 		return -EINVAL;
4690 
4691 	if (sbi->s_daxdev) {
4692 		if (sb->s_blocksize == PAGE_SIZE)
4693 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4694 		else
4695 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4696 	}
4697 
4698 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4699 		if (ext4_has_feature_inline_data(sb)) {
4700 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4701 					" that may contain inline data");
4702 			return -EINVAL;
4703 		}
4704 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4705 			ext4_msg(sb, KERN_ERR,
4706 				"DAX unsupported by block device.");
4707 			return -EINVAL;
4708 		}
4709 	}
4710 
4711 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4712 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4713 			 es->s_encryption_level);
4714 		return -EINVAL;
4715 	}
4716 
4717 	return 0;
4718 }
4719 
4720 static int ext4_check_geometry(struct super_block *sb,
4721 			       struct ext4_super_block *es)
4722 {
4723 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4724 	__u64 blocks_count;
4725 	int err;
4726 
4727 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4728 		ext4_msg(sb, KERN_ERR,
4729 			 "Number of reserved GDT blocks insanely large: %d",
4730 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4731 		return -EINVAL;
4732 	}
4733 	/*
4734 	 * Test whether we have more sectors than will fit in sector_t,
4735 	 * and whether the max offset is addressable by the page cache.
4736 	 */
4737 	err = generic_check_addressable(sb->s_blocksize_bits,
4738 					ext4_blocks_count(es));
4739 	if (err) {
4740 		ext4_msg(sb, KERN_ERR, "filesystem"
4741 			 " too large to mount safely on this system");
4742 		return err;
4743 	}
4744 
4745 	/* check blocks count against device size */
4746 	blocks_count = sb_bdev_nr_blocks(sb);
4747 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4748 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4749 		       "exceeds size of device (%llu blocks)",
4750 		       ext4_blocks_count(es), blocks_count);
4751 		return -EINVAL;
4752 	}
4753 
4754 	/*
4755 	 * It makes no sense for the first data block to be beyond the end
4756 	 * of the filesystem.
4757 	 */
4758 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4759 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4760 			 "block %u is beyond end of filesystem (%llu)",
4761 			 le32_to_cpu(es->s_first_data_block),
4762 			 ext4_blocks_count(es));
4763 		return -EINVAL;
4764 	}
4765 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4766 	    (sbi->s_cluster_ratio == 1)) {
4767 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4768 			 "block is 0 with a 1k block and cluster size");
4769 		return -EINVAL;
4770 	}
4771 
4772 	blocks_count = (ext4_blocks_count(es) -
4773 			le32_to_cpu(es->s_first_data_block) +
4774 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4775 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4776 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4777 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4778 		       "(block count %llu, first data block %u, "
4779 		       "blocks per group %lu)", blocks_count,
4780 		       ext4_blocks_count(es),
4781 		       le32_to_cpu(es->s_first_data_block),
4782 		       EXT4_BLOCKS_PER_GROUP(sb));
4783 		return -EINVAL;
4784 	}
4785 	sbi->s_groups_count = blocks_count;
4786 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4787 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4788 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4789 	    le32_to_cpu(es->s_inodes_count)) {
4790 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4791 			 le32_to_cpu(es->s_inodes_count),
4792 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4793 		return -EINVAL;
4794 	}
4795 
4796 	return 0;
4797 }
4798 
4799 static int ext4_group_desc_init(struct super_block *sb,
4800 				struct ext4_super_block *es,
4801 				ext4_fsblk_t logical_sb_block,
4802 				ext4_group_t *first_not_zeroed)
4803 {
4804 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4805 	unsigned int db_count;
4806 	ext4_fsblk_t block;
4807 	int i;
4808 
4809 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4810 		   EXT4_DESC_PER_BLOCK(sb);
4811 	if (ext4_has_feature_meta_bg(sb)) {
4812 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4813 			ext4_msg(sb, KERN_WARNING,
4814 				 "first meta block group too large: %u "
4815 				 "(group descriptor block count %u)",
4816 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4817 			return -EINVAL;
4818 		}
4819 	}
4820 	rcu_assign_pointer(sbi->s_group_desc,
4821 			   kvmalloc_array(db_count,
4822 					  sizeof(struct buffer_head *),
4823 					  GFP_KERNEL));
4824 	if (sbi->s_group_desc == NULL) {
4825 		ext4_msg(sb, KERN_ERR, "not enough memory");
4826 		return -ENOMEM;
4827 	}
4828 
4829 	bgl_lock_init(sbi->s_blockgroup_lock);
4830 
4831 	/* Pre-read the descriptors into the buffer cache */
4832 	for (i = 0; i < db_count; i++) {
4833 		block = descriptor_loc(sb, logical_sb_block, i);
4834 		ext4_sb_breadahead_unmovable(sb, block);
4835 	}
4836 
4837 	for (i = 0; i < db_count; i++) {
4838 		struct buffer_head *bh;
4839 
4840 		block = descriptor_loc(sb, logical_sb_block, i);
4841 		bh = ext4_sb_bread_unmovable(sb, block);
4842 		if (IS_ERR(bh)) {
4843 			ext4_msg(sb, KERN_ERR,
4844 			       "can't read group descriptor %d", i);
4845 			sbi->s_gdb_count = i;
4846 			return PTR_ERR(bh);
4847 		}
4848 		rcu_read_lock();
4849 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4850 		rcu_read_unlock();
4851 	}
4852 	sbi->s_gdb_count = db_count;
4853 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4854 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4855 		return -EFSCORRUPTED;
4856 	}
4857 
4858 	return 0;
4859 }
4860 
4861 static int ext4_load_and_init_journal(struct super_block *sb,
4862 				      struct ext4_super_block *es,
4863 				      struct ext4_fs_context *ctx)
4864 {
4865 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4866 	int err;
4867 
4868 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4869 	if (err)
4870 		return err;
4871 
4872 	if (ext4_has_feature_64bit(sb) &&
4873 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4874 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4875 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4876 		goto out;
4877 	}
4878 
4879 	if (!set_journal_csum_feature_set(sb)) {
4880 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4881 			 "feature set");
4882 		goto out;
4883 	}
4884 
4885 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4886 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4887 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4888 		ext4_msg(sb, KERN_ERR,
4889 			"Failed to set fast commit journal feature");
4890 		goto out;
4891 	}
4892 
4893 	/* We have now updated the journal if required, so we can
4894 	 * validate the data journaling mode. */
4895 	switch (test_opt(sb, DATA_FLAGS)) {
4896 	case 0:
4897 		/* No mode set, assume a default based on the journal
4898 		 * capabilities: ORDERED_DATA if the journal can
4899 		 * cope, else JOURNAL_DATA
4900 		 */
4901 		if (jbd2_journal_check_available_features
4902 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4903 			set_opt(sb, ORDERED_DATA);
4904 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4905 		} else {
4906 			set_opt(sb, JOURNAL_DATA);
4907 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4908 		}
4909 		break;
4910 
4911 	case EXT4_MOUNT_ORDERED_DATA:
4912 	case EXT4_MOUNT_WRITEBACK_DATA:
4913 		if (!jbd2_journal_check_available_features
4914 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4915 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4916 			       "requested data journaling mode");
4917 			goto out;
4918 		}
4919 		break;
4920 	default:
4921 		break;
4922 	}
4923 
4924 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4925 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4926 		ext4_msg(sb, KERN_ERR, "can't mount with "
4927 			"journal_async_commit in data=ordered mode");
4928 		goto out;
4929 	}
4930 
4931 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4932 
4933 	sbi->s_journal->j_submit_inode_data_buffers =
4934 		ext4_journal_submit_inode_data_buffers;
4935 	sbi->s_journal->j_finish_inode_data_buffers =
4936 		ext4_journal_finish_inode_data_buffers;
4937 
4938 	return 0;
4939 
4940 out:
4941 	/* flush s_sb_upd_work before destroying the journal. */
4942 	flush_work(&sbi->s_sb_upd_work);
4943 	jbd2_journal_destroy(sbi->s_journal);
4944 	sbi->s_journal = NULL;
4945 	return -EINVAL;
4946 }
4947 
4948 static int ext4_check_journal_data_mode(struct super_block *sb)
4949 {
4950 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4951 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4952 			    "data=journal disables delayed allocation, "
4953 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4954 		/* can't mount with both data=journal and dioread_nolock. */
4955 		clear_opt(sb, DIOREAD_NOLOCK);
4956 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4957 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4958 			ext4_msg(sb, KERN_ERR, "can't mount with "
4959 				 "both data=journal and delalloc");
4960 			return -EINVAL;
4961 		}
4962 		if (test_opt(sb, DAX_ALWAYS)) {
4963 			ext4_msg(sb, KERN_ERR, "can't mount with "
4964 				 "both data=journal and dax");
4965 			return -EINVAL;
4966 		}
4967 		if (ext4_has_feature_encrypt(sb)) {
4968 			ext4_msg(sb, KERN_WARNING,
4969 				 "encrypted files will use data=ordered "
4970 				 "instead of data journaling mode");
4971 		}
4972 		if (test_opt(sb, DELALLOC))
4973 			clear_opt(sb, DELALLOC);
4974 	} else {
4975 		sb->s_iflags |= SB_I_CGROUPWB;
4976 	}
4977 
4978 	return 0;
4979 }
4980 
4981 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
4982 			   int silent)
4983 {
4984 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4985 	struct ext4_super_block *es;
4986 	ext4_fsblk_t logical_sb_block;
4987 	unsigned long offset = 0;
4988 	struct buffer_head *bh;
4989 	int ret = -EINVAL;
4990 	int blocksize;
4991 
4992 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4993 	if (!blocksize) {
4994 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4995 		return -EINVAL;
4996 	}
4997 
4998 	/*
4999 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5000 	 * block sizes.  We need to calculate the offset from buffer start.
5001 	 */
5002 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5003 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5004 		offset = do_div(logical_sb_block, blocksize);
5005 	} else {
5006 		logical_sb_block = sbi->s_sb_block;
5007 	}
5008 
5009 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5010 	if (IS_ERR(bh)) {
5011 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5012 		return PTR_ERR(bh);
5013 	}
5014 	/*
5015 	 * Note: s_es must be initialized as soon as possible because
5016 	 *       some ext4 macro-instructions depend on its value
5017 	 */
5018 	es = (struct ext4_super_block *) (bh->b_data + offset);
5019 	sbi->s_es = es;
5020 	sb->s_magic = le16_to_cpu(es->s_magic);
5021 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5022 		if (!silent)
5023 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5024 		goto out;
5025 	}
5026 
5027 	if (le32_to_cpu(es->s_log_block_size) >
5028 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5029 		ext4_msg(sb, KERN_ERR,
5030 			 "Invalid log block size: %u",
5031 			 le32_to_cpu(es->s_log_block_size));
5032 		goto out;
5033 	}
5034 	if (le32_to_cpu(es->s_log_cluster_size) >
5035 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5036 		ext4_msg(sb, KERN_ERR,
5037 			 "Invalid log cluster size: %u",
5038 			 le32_to_cpu(es->s_log_cluster_size));
5039 		goto out;
5040 	}
5041 
5042 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5043 
5044 	/*
5045 	 * If the default block size is not the same as the real block size,
5046 	 * we need to reload it.
5047 	 */
5048 	if (sb->s_blocksize == blocksize) {
5049 		*lsb = logical_sb_block;
5050 		sbi->s_sbh = bh;
5051 		return 0;
5052 	}
5053 
5054 	/*
5055 	 * bh must be released before kill_bdev(), otherwise
5056 	 * it won't be freed and its page also. kill_bdev()
5057 	 * is called by sb_set_blocksize().
5058 	 */
5059 	brelse(bh);
5060 	/* Validate the filesystem blocksize */
5061 	if (!sb_set_blocksize(sb, blocksize)) {
5062 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5063 				blocksize);
5064 		bh = NULL;
5065 		goto out;
5066 	}
5067 
5068 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5069 	offset = do_div(logical_sb_block, blocksize);
5070 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5071 	if (IS_ERR(bh)) {
5072 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5073 		ret = PTR_ERR(bh);
5074 		bh = NULL;
5075 		goto out;
5076 	}
5077 	es = (struct ext4_super_block *)(bh->b_data + offset);
5078 	sbi->s_es = es;
5079 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5080 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5081 		goto out;
5082 	}
5083 	*lsb = logical_sb_block;
5084 	sbi->s_sbh = bh;
5085 	return 0;
5086 out:
5087 	brelse(bh);
5088 	return ret;
5089 }
5090 
5091 static int ext4_hash_info_init(struct super_block *sb)
5092 {
5093 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5094 	struct ext4_super_block *es = sbi->s_es;
5095 	unsigned int i;
5096 
5097 	sbi->s_def_hash_version = es->s_def_hash_version;
5098 
5099 	if (sbi->s_def_hash_version > DX_HASH_LAST) {
5100 		ext4_msg(sb, KERN_ERR,
5101 			 "Invalid default hash set in the superblock");
5102 		return -EINVAL;
5103 	} else if (sbi->s_def_hash_version == DX_HASH_SIPHASH) {
5104 		ext4_msg(sb, KERN_ERR,
5105 			 "SIPHASH is not a valid default hash value");
5106 		return -EINVAL;
5107 	}
5108 
5109 	for (i = 0; i < 4; i++)
5110 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5111 
5112 	if (ext4_has_feature_dir_index(sb)) {
5113 		i = le32_to_cpu(es->s_flags);
5114 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5115 			sbi->s_hash_unsigned = 3;
5116 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5117 #ifdef __CHAR_UNSIGNED__
5118 			if (!sb_rdonly(sb))
5119 				es->s_flags |=
5120 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5121 			sbi->s_hash_unsigned = 3;
5122 #else
5123 			if (!sb_rdonly(sb))
5124 				es->s_flags |=
5125 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5126 #endif
5127 		}
5128 	}
5129 	return 0;
5130 }
5131 
5132 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5133 {
5134 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5135 	struct ext4_super_block *es = sbi->s_es;
5136 	int has_huge_files;
5137 
5138 	has_huge_files = ext4_has_feature_huge_file(sb);
5139 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5140 						      has_huge_files);
5141 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5142 
5143 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5144 	if (ext4_has_feature_64bit(sb)) {
5145 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5146 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5147 		    !is_power_of_2(sbi->s_desc_size)) {
5148 			ext4_msg(sb, KERN_ERR,
5149 			       "unsupported descriptor size %lu",
5150 			       sbi->s_desc_size);
5151 			return -EINVAL;
5152 		}
5153 	} else
5154 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5155 
5156 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5157 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5158 
5159 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5160 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5161 		if (!silent)
5162 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5163 		return -EINVAL;
5164 	}
5165 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5166 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5167 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5168 			 sbi->s_inodes_per_group);
5169 		return -EINVAL;
5170 	}
5171 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5172 					sbi->s_inodes_per_block;
5173 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5174 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5175 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5176 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5177 
5178 	return 0;
5179 }
5180 
5181 /*
5182  * It's hard to get stripe aligned blocks if stripe is not aligned with
5183  * cluster, just disable stripe and alert user to simplify code and avoid
5184  * stripe aligned allocation which will rarely succeed.
5185  */
5186 static bool ext4_is_stripe_incompatible(struct super_block *sb, unsigned long stripe)
5187 {
5188 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5189 	return (stripe > 0 && sbi->s_cluster_ratio > 1 &&
5190 		stripe % sbi->s_cluster_ratio != 0);
5191 }
5192 
5193 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5194 {
5195 	struct ext4_super_block *es = NULL;
5196 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5197 	ext4_fsblk_t logical_sb_block;
5198 	struct inode *root;
5199 	int needs_recovery;
5200 	int err;
5201 	ext4_group_t first_not_zeroed;
5202 	struct ext4_fs_context *ctx = fc->fs_private;
5203 	int silent = fc->sb_flags & SB_SILENT;
5204 
5205 	/* Set defaults for the variables that will be set during parsing */
5206 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5207 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5208 
5209 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5210 	sbi->s_sectors_written_start =
5211 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5212 
5213 	err = ext4_load_super(sb, &logical_sb_block, silent);
5214 	if (err)
5215 		goto out_fail;
5216 
5217 	es = sbi->s_es;
5218 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5219 
5220 	err = ext4_init_metadata_csum(sb, es);
5221 	if (err)
5222 		goto failed_mount;
5223 
5224 	ext4_set_def_opts(sb, es);
5225 
5226 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5227 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5228 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5229 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5230 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5231 
5232 	/*
5233 	 * set default s_li_wait_mult for lazyinit, for the case there is
5234 	 * no mount option specified.
5235 	 */
5236 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5237 
5238 	err = ext4_inode_info_init(sb, es);
5239 	if (err)
5240 		goto failed_mount;
5241 
5242 	err = parse_apply_sb_mount_options(sb, ctx);
5243 	if (err < 0)
5244 		goto failed_mount;
5245 
5246 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5247 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5248 
5249 	err = ext4_check_opt_consistency(fc, sb);
5250 	if (err < 0)
5251 		goto failed_mount;
5252 
5253 	ext4_apply_options(fc, sb);
5254 
5255 	err = ext4_encoding_init(sb, es);
5256 	if (err)
5257 		goto failed_mount;
5258 
5259 	err = ext4_check_journal_data_mode(sb);
5260 	if (err)
5261 		goto failed_mount;
5262 
5263 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5264 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5265 
5266 	/* i_version is always enabled now */
5267 	sb->s_flags |= SB_I_VERSION;
5268 
5269 	err = ext4_check_feature_compatibility(sb, es, silent);
5270 	if (err)
5271 		goto failed_mount;
5272 
5273 	err = ext4_block_group_meta_init(sb, silent);
5274 	if (err)
5275 		goto failed_mount;
5276 
5277 	err = ext4_hash_info_init(sb);
5278 	if (err)
5279 		goto failed_mount;
5280 
5281 	err = ext4_handle_clustersize(sb);
5282 	if (err)
5283 		goto failed_mount;
5284 
5285 	err = ext4_check_geometry(sb, es);
5286 	if (err)
5287 		goto failed_mount;
5288 
5289 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5290 	spin_lock_init(&sbi->s_error_lock);
5291 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5292 
5293 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5294 	if (err)
5295 		goto failed_mount3;
5296 
5297 	err = ext4_es_register_shrinker(sbi);
5298 	if (err)
5299 		goto failed_mount3;
5300 
5301 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5302 	if (ext4_is_stripe_incompatible(sb, sbi->s_stripe)) {
5303 		ext4_msg(sb, KERN_WARNING,
5304 			 "stripe (%lu) is not aligned with cluster size (%u), "
5305 			 "stripe is disabled",
5306 			 sbi->s_stripe, sbi->s_cluster_ratio);
5307 		sbi->s_stripe = 0;
5308 	}
5309 	sbi->s_extent_max_zeroout_kb = 32;
5310 
5311 	/*
5312 	 * set up enough so that it can read an inode
5313 	 */
5314 	sb->s_op = &ext4_sops;
5315 	sb->s_export_op = &ext4_export_ops;
5316 	sb->s_xattr = ext4_xattr_handlers;
5317 #ifdef CONFIG_FS_ENCRYPTION
5318 	sb->s_cop = &ext4_cryptops;
5319 #endif
5320 #ifdef CONFIG_FS_VERITY
5321 	sb->s_vop = &ext4_verityops;
5322 #endif
5323 #ifdef CONFIG_QUOTA
5324 	sb->dq_op = &ext4_quota_operations;
5325 	if (ext4_has_feature_quota(sb))
5326 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5327 	else
5328 		sb->s_qcop = &ext4_qctl_operations;
5329 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5330 #endif
5331 	super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));
5332 	super_set_sysfs_name_bdev(sb);
5333 
5334 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5335 	mutex_init(&sbi->s_orphan_lock);
5336 
5337 	spin_lock_init(&sbi->s_bdev_wb_lock);
5338 
5339 	ext4_fast_commit_init(sb);
5340 
5341 	sb->s_root = NULL;
5342 
5343 	needs_recovery = (es->s_last_orphan != 0 ||
5344 			  ext4_has_feature_orphan_present(sb) ||
5345 			  ext4_has_feature_journal_needs_recovery(sb));
5346 
5347 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5348 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5349 		if (err)
5350 			goto failed_mount3a;
5351 	}
5352 
5353 	err = -EINVAL;
5354 	/*
5355 	 * The first inode we look at is the journal inode.  Don't try
5356 	 * root first: it may be modified in the journal!
5357 	 */
5358 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5359 		err = ext4_load_and_init_journal(sb, es, ctx);
5360 		if (err)
5361 			goto failed_mount3a;
5362 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5363 		   ext4_has_feature_journal_needs_recovery(sb)) {
5364 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5365 		       "suppressed and not mounted read-only");
5366 		goto failed_mount3a;
5367 	} else {
5368 		/* Nojournal mode, all journal mount options are illegal */
5369 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5370 			ext4_msg(sb, KERN_ERR, "can't mount with "
5371 				 "journal_async_commit, fs mounted w/o journal");
5372 			goto failed_mount3a;
5373 		}
5374 
5375 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5376 			ext4_msg(sb, KERN_ERR, "can't mount with "
5377 				 "journal_checksum, fs mounted w/o journal");
5378 			goto failed_mount3a;
5379 		}
5380 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5381 			ext4_msg(sb, KERN_ERR, "can't mount with "
5382 				 "commit=%lu, fs mounted w/o journal",
5383 				 sbi->s_commit_interval / HZ);
5384 			goto failed_mount3a;
5385 		}
5386 		if (EXT4_MOUNT_DATA_FLAGS &
5387 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5388 			ext4_msg(sb, KERN_ERR, "can't mount with "
5389 				 "data=, fs mounted w/o journal");
5390 			goto failed_mount3a;
5391 		}
5392 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5393 		clear_opt(sb, JOURNAL_CHECKSUM);
5394 		clear_opt(sb, DATA_FLAGS);
5395 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5396 		sbi->s_journal = NULL;
5397 		needs_recovery = 0;
5398 	}
5399 
5400 	if (!test_opt(sb, NO_MBCACHE)) {
5401 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5402 		if (!sbi->s_ea_block_cache) {
5403 			ext4_msg(sb, KERN_ERR,
5404 				 "Failed to create ea_block_cache");
5405 			err = -EINVAL;
5406 			goto failed_mount_wq;
5407 		}
5408 
5409 		if (ext4_has_feature_ea_inode(sb)) {
5410 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5411 			if (!sbi->s_ea_inode_cache) {
5412 				ext4_msg(sb, KERN_ERR,
5413 					 "Failed to create ea_inode_cache");
5414 				err = -EINVAL;
5415 				goto failed_mount_wq;
5416 			}
5417 		}
5418 	}
5419 
5420 	/*
5421 	 * Get the # of file system overhead blocks from the
5422 	 * superblock if present.
5423 	 */
5424 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5425 	/* ignore the precalculated value if it is ridiculous */
5426 	if (sbi->s_overhead > ext4_blocks_count(es))
5427 		sbi->s_overhead = 0;
5428 	/*
5429 	 * If the bigalloc feature is not enabled recalculating the
5430 	 * overhead doesn't take long, so we might as well just redo
5431 	 * it to make sure we are using the correct value.
5432 	 */
5433 	if (!ext4_has_feature_bigalloc(sb))
5434 		sbi->s_overhead = 0;
5435 	if (sbi->s_overhead == 0) {
5436 		err = ext4_calculate_overhead(sb);
5437 		if (err)
5438 			goto failed_mount_wq;
5439 	}
5440 
5441 	/*
5442 	 * The maximum number of concurrent works can be high and
5443 	 * concurrency isn't really necessary.  Limit it to 1.
5444 	 */
5445 	EXT4_SB(sb)->rsv_conversion_wq =
5446 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5447 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5448 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5449 		err = -ENOMEM;
5450 		goto failed_mount4;
5451 	}
5452 
5453 	/*
5454 	 * The jbd2_journal_load will have done any necessary log recovery,
5455 	 * so we can safely mount the rest of the filesystem now.
5456 	 */
5457 
5458 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5459 	if (IS_ERR(root)) {
5460 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5461 		err = PTR_ERR(root);
5462 		root = NULL;
5463 		goto failed_mount4;
5464 	}
5465 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5466 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5467 		iput(root);
5468 		err = -EFSCORRUPTED;
5469 		goto failed_mount4;
5470 	}
5471 
5472 	generic_set_sb_d_ops(sb);
5473 	sb->s_root = d_make_root(root);
5474 	if (!sb->s_root) {
5475 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5476 		err = -ENOMEM;
5477 		goto failed_mount4;
5478 	}
5479 
5480 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5481 	if (err == -EROFS) {
5482 		sb->s_flags |= SB_RDONLY;
5483 	} else if (err)
5484 		goto failed_mount4a;
5485 
5486 	ext4_set_resv_clusters(sb);
5487 
5488 	if (test_opt(sb, BLOCK_VALIDITY)) {
5489 		err = ext4_setup_system_zone(sb);
5490 		if (err) {
5491 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5492 				 "zone (%d)", err);
5493 			goto failed_mount4a;
5494 		}
5495 	}
5496 	ext4_fc_replay_cleanup(sb);
5497 
5498 	ext4_ext_init(sb);
5499 
5500 	/*
5501 	 * Enable optimize_scan if number of groups is > threshold. This can be
5502 	 * turned off by passing "mb_optimize_scan=0". This can also be
5503 	 * turned on forcefully by passing "mb_optimize_scan=1".
5504 	 */
5505 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5506 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5507 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5508 		else
5509 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5510 	}
5511 
5512 	err = ext4_mb_init(sb);
5513 	if (err) {
5514 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5515 			 err);
5516 		goto failed_mount5;
5517 	}
5518 
5519 	/*
5520 	 * We can only set up the journal commit callback once
5521 	 * mballoc is initialized
5522 	 */
5523 	if (sbi->s_journal)
5524 		sbi->s_journal->j_commit_callback =
5525 			ext4_journal_commit_callback;
5526 
5527 	err = ext4_percpu_param_init(sbi);
5528 	if (err)
5529 		goto failed_mount6;
5530 
5531 	if (ext4_has_feature_flex_bg(sb))
5532 		if (!ext4_fill_flex_info(sb)) {
5533 			ext4_msg(sb, KERN_ERR,
5534 			       "unable to initialize "
5535 			       "flex_bg meta info!");
5536 			err = -ENOMEM;
5537 			goto failed_mount6;
5538 		}
5539 
5540 	err = ext4_register_li_request(sb, first_not_zeroed);
5541 	if (err)
5542 		goto failed_mount6;
5543 
5544 	err = ext4_init_orphan_info(sb);
5545 	if (err)
5546 		goto failed_mount7;
5547 #ifdef CONFIG_QUOTA
5548 	/* Enable quota usage during mount. */
5549 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5550 		err = ext4_enable_quotas(sb);
5551 		if (err)
5552 			goto failed_mount8;
5553 	}
5554 #endif  /* CONFIG_QUOTA */
5555 
5556 	/*
5557 	 * Save the original bdev mapping's wb_err value which could be
5558 	 * used to detect the metadata async write error.
5559 	 */
5560 	errseq_check_and_advance(&sb->s_bdev->bd_mapping->wb_err,
5561 				 &sbi->s_bdev_wb_err);
5562 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5563 	ext4_orphan_cleanup(sb, es);
5564 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5565 	/*
5566 	 * Update the checksum after updating free space/inode counters and
5567 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5568 	 * checksum in the buffer cache until it is written out and
5569 	 * e2fsprogs programs trying to open a file system immediately
5570 	 * after it is mounted can fail.
5571 	 */
5572 	ext4_superblock_csum_set(sb);
5573 	if (needs_recovery) {
5574 		ext4_msg(sb, KERN_INFO, "recovery complete");
5575 		err = ext4_mark_recovery_complete(sb, es);
5576 		if (err)
5577 			goto failed_mount9;
5578 	}
5579 
5580 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5581 		ext4_msg(sb, KERN_WARNING,
5582 			 "mounting with \"discard\" option, but the device does not support discard");
5583 
5584 	if (es->s_error_count)
5585 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5586 
5587 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5588 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5589 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5590 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5591 	atomic_set(&sbi->s_warning_count, 0);
5592 	atomic_set(&sbi->s_msg_count, 0);
5593 
5594 	/* Register sysfs after all initializations are complete. */
5595 	err = ext4_register_sysfs(sb);
5596 	if (err)
5597 		goto failed_mount9;
5598 
5599 	return 0;
5600 
5601 failed_mount9:
5602 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5603 failed_mount8: __maybe_unused
5604 	ext4_release_orphan_info(sb);
5605 failed_mount7:
5606 	ext4_unregister_li_request(sb);
5607 failed_mount6:
5608 	ext4_mb_release(sb);
5609 	ext4_flex_groups_free(sbi);
5610 	ext4_percpu_param_destroy(sbi);
5611 failed_mount5:
5612 	ext4_ext_release(sb);
5613 	ext4_release_system_zone(sb);
5614 failed_mount4a:
5615 	dput(sb->s_root);
5616 	sb->s_root = NULL;
5617 failed_mount4:
5618 	ext4_msg(sb, KERN_ERR, "mount failed");
5619 	if (EXT4_SB(sb)->rsv_conversion_wq)
5620 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5621 failed_mount_wq:
5622 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5623 	sbi->s_ea_inode_cache = NULL;
5624 
5625 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5626 	sbi->s_ea_block_cache = NULL;
5627 
5628 	if (sbi->s_journal) {
5629 		/* flush s_sb_upd_work before journal destroy. */
5630 		flush_work(&sbi->s_sb_upd_work);
5631 		jbd2_journal_destroy(sbi->s_journal);
5632 		sbi->s_journal = NULL;
5633 	}
5634 failed_mount3a:
5635 	ext4_es_unregister_shrinker(sbi);
5636 failed_mount3:
5637 	/* flush s_sb_upd_work before sbi destroy */
5638 	flush_work(&sbi->s_sb_upd_work);
5639 	ext4_stop_mmpd(sbi);
5640 	del_timer_sync(&sbi->s_err_report);
5641 	ext4_group_desc_free(sbi);
5642 failed_mount:
5643 	if (sbi->s_chksum_driver)
5644 		crypto_free_shash(sbi->s_chksum_driver);
5645 
5646 #if IS_ENABLED(CONFIG_UNICODE)
5647 	utf8_unload(sb->s_encoding);
5648 #endif
5649 
5650 #ifdef CONFIG_QUOTA
5651 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5652 		kfree(get_qf_name(sb, sbi, i));
5653 #endif
5654 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5655 	brelse(sbi->s_sbh);
5656 	if (sbi->s_journal_bdev_file) {
5657 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
5658 		bdev_fput(sbi->s_journal_bdev_file);
5659 	}
5660 out_fail:
5661 	invalidate_bdev(sb->s_bdev);
5662 	sb->s_fs_info = NULL;
5663 	return err;
5664 }
5665 
5666 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5667 {
5668 	struct ext4_fs_context *ctx = fc->fs_private;
5669 	struct ext4_sb_info *sbi;
5670 	const char *descr;
5671 	int ret;
5672 
5673 	sbi = ext4_alloc_sbi(sb);
5674 	if (!sbi)
5675 		return -ENOMEM;
5676 
5677 	fc->s_fs_info = sbi;
5678 
5679 	/* Cleanup superblock name */
5680 	strreplace(sb->s_id, '/', '!');
5681 
5682 	sbi->s_sb_block = 1;	/* Default super block location */
5683 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5684 		sbi->s_sb_block = ctx->s_sb_block;
5685 
5686 	ret = __ext4_fill_super(fc, sb);
5687 	if (ret < 0)
5688 		goto free_sbi;
5689 
5690 	if (sbi->s_journal) {
5691 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5692 			descr = " journalled data mode";
5693 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5694 			descr = " ordered data mode";
5695 		else
5696 			descr = " writeback data mode";
5697 	} else
5698 		descr = "out journal";
5699 
5700 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5701 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5702 			 "Quota mode: %s.", &sb->s_uuid,
5703 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5704 			 ext4_quota_mode(sb));
5705 
5706 	/* Update the s_overhead_clusters if necessary */
5707 	ext4_update_overhead(sb, false);
5708 	return 0;
5709 
5710 free_sbi:
5711 	ext4_free_sbi(sbi);
5712 	fc->s_fs_info = NULL;
5713 	return ret;
5714 }
5715 
5716 static int ext4_get_tree(struct fs_context *fc)
5717 {
5718 	return get_tree_bdev(fc, ext4_fill_super);
5719 }
5720 
5721 /*
5722  * Setup any per-fs journal parameters now.  We'll do this both on
5723  * initial mount, once the journal has been initialised but before we've
5724  * done any recovery; and again on any subsequent remount.
5725  */
5726 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5727 {
5728 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5729 
5730 	journal->j_commit_interval = sbi->s_commit_interval;
5731 	journal->j_min_batch_time = sbi->s_min_batch_time;
5732 	journal->j_max_batch_time = sbi->s_max_batch_time;
5733 	ext4_fc_init(sb, journal);
5734 
5735 	write_lock(&journal->j_state_lock);
5736 	if (test_opt(sb, BARRIER))
5737 		journal->j_flags |= JBD2_BARRIER;
5738 	else
5739 		journal->j_flags &= ~JBD2_BARRIER;
5740 	if (test_opt(sb, DATA_ERR_ABORT))
5741 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5742 	else
5743 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5744 	/*
5745 	 * Always enable journal cycle record option, letting the journal
5746 	 * records log transactions continuously between each mount.
5747 	 */
5748 	journal->j_flags |= JBD2_CYCLE_RECORD;
5749 	write_unlock(&journal->j_state_lock);
5750 }
5751 
5752 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5753 					     unsigned int journal_inum)
5754 {
5755 	struct inode *journal_inode;
5756 
5757 	/*
5758 	 * Test for the existence of a valid inode on disk.  Bad things
5759 	 * happen if we iget() an unused inode, as the subsequent iput()
5760 	 * will try to delete it.
5761 	 */
5762 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5763 	if (IS_ERR(journal_inode)) {
5764 		ext4_msg(sb, KERN_ERR, "no journal found");
5765 		return ERR_CAST(journal_inode);
5766 	}
5767 	if (!journal_inode->i_nlink) {
5768 		make_bad_inode(journal_inode);
5769 		iput(journal_inode);
5770 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5771 		return ERR_PTR(-EFSCORRUPTED);
5772 	}
5773 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5774 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5775 		iput(journal_inode);
5776 		return ERR_PTR(-EFSCORRUPTED);
5777 	}
5778 
5779 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5780 		  journal_inode, journal_inode->i_size);
5781 	return journal_inode;
5782 }
5783 
5784 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5785 {
5786 	struct ext4_map_blocks map;
5787 	int ret;
5788 
5789 	if (journal->j_inode == NULL)
5790 		return 0;
5791 
5792 	map.m_lblk = *block;
5793 	map.m_len = 1;
5794 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5795 	if (ret <= 0) {
5796 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5797 			 "journal bmap failed: block %llu ret %d\n",
5798 			 *block, ret);
5799 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5800 		return ret;
5801 	}
5802 	*block = map.m_pblk;
5803 	return 0;
5804 }
5805 
5806 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5807 					  unsigned int journal_inum)
5808 {
5809 	struct inode *journal_inode;
5810 	journal_t *journal;
5811 
5812 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5813 	if (IS_ERR(journal_inode))
5814 		return ERR_CAST(journal_inode);
5815 
5816 	journal = jbd2_journal_init_inode(journal_inode);
5817 	if (IS_ERR(journal)) {
5818 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5819 		iput(journal_inode);
5820 		return ERR_CAST(journal);
5821 	}
5822 	journal->j_private = sb;
5823 	journal->j_bmap = ext4_journal_bmap;
5824 	ext4_init_journal_params(sb, journal);
5825 	return journal;
5826 }
5827 
5828 static struct file *ext4_get_journal_blkdev(struct super_block *sb,
5829 					dev_t j_dev, ext4_fsblk_t *j_start,
5830 					ext4_fsblk_t *j_len)
5831 {
5832 	struct buffer_head *bh;
5833 	struct block_device *bdev;
5834 	struct file *bdev_file;
5835 	int hblock, blocksize;
5836 	ext4_fsblk_t sb_block;
5837 	unsigned long offset;
5838 	struct ext4_super_block *es;
5839 	int errno;
5840 
5841 	bdev_file = bdev_file_open_by_dev(j_dev,
5842 		BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
5843 		sb, &fs_holder_ops);
5844 	if (IS_ERR(bdev_file)) {
5845 		ext4_msg(sb, KERN_ERR,
5846 			 "failed to open journal device unknown-block(%u,%u) %ld",
5847 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev_file));
5848 		return bdev_file;
5849 	}
5850 
5851 	bdev = file_bdev(bdev_file);
5852 	blocksize = sb->s_blocksize;
5853 	hblock = bdev_logical_block_size(bdev);
5854 	if (blocksize < hblock) {
5855 		ext4_msg(sb, KERN_ERR,
5856 			"blocksize too small for journal device");
5857 		errno = -EINVAL;
5858 		goto out_bdev;
5859 	}
5860 
5861 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5862 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5863 	set_blocksize(bdev_file, blocksize);
5864 	bh = __bread(bdev, sb_block, blocksize);
5865 	if (!bh) {
5866 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5867 		       "external journal");
5868 		errno = -EINVAL;
5869 		goto out_bdev;
5870 	}
5871 
5872 	es = (struct ext4_super_block *) (bh->b_data + offset);
5873 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5874 	    !(le32_to_cpu(es->s_feature_incompat) &
5875 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5876 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
5877 		errno = -EFSCORRUPTED;
5878 		goto out_bh;
5879 	}
5880 
5881 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5882 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5883 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5884 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
5885 		errno = -EFSCORRUPTED;
5886 		goto out_bh;
5887 	}
5888 
5889 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5890 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5891 		errno = -EFSCORRUPTED;
5892 		goto out_bh;
5893 	}
5894 
5895 	*j_start = sb_block + 1;
5896 	*j_len = ext4_blocks_count(es);
5897 	brelse(bh);
5898 	return bdev_file;
5899 
5900 out_bh:
5901 	brelse(bh);
5902 out_bdev:
5903 	bdev_fput(bdev_file);
5904 	return ERR_PTR(errno);
5905 }
5906 
5907 static journal_t *ext4_open_dev_journal(struct super_block *sb,
5908 					dev_t j_dev)
5909 {
5910 	journal_t *journal;
5911 	ext4_fsblk_t j_start;
5912 	ext4_fsblk_t j_len;
5913 	struct file *bdev_file;
5914 	int errno = 0;
5915 
5916 	bdev_file = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
5917 	if (IS_ERR(bdev_file))
5918 		return ERR_CAST(bdev_file);
5919 
5920 	journal = jbd2_journal_init_dev(file_bdev(bdev_file), sb->s_bdev, j_start,
5921 					j_len, sb->s_blocksize);
5922 	if (IS_ERR(journal)) {
5923 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5924 		errno = PTR_ERR(journal);
5925 		goto out_bdev;
5926 	}
5927 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5928 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5929 					"user (unsupported) - %d",
5930 			be32_to_cpu(journal->j_superblock->s_nr_users));
5931 		errno = -EINVAL;
5932 		goto out_journal;
5933 	}
5934 	journal->j_private = sb;
5935 	EXT4_SB(sb)->s_journal_bdev_file = bdev_file;
5936 	ext4_init_journal_params(sb, journal);
5937 	return journal;
5938 
5939 out_journal:
5940 	jbd2_journal_destroy(journal);
5941 out_bdev:
5942 	bdev_fput(bdev_file);
5943 	return ERR_PTR(errno);
5944 }
5945 
5946 static int ext4_load_journal(struct super_block *sb,
5947 			     struct ext4_super_block *es,
5948 			     unsigned long journal_devnum)
5949 {
5950 	journal_t *journal;
5951 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5952 	dev_t journal_dev;
5953 	int err = 0;
5954 	int really_read_only;
5955 	int journal_dev_ro;
5956 
5957 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5958 		return -EFSCORRUPTED;
5959 
5960 	if (journal_devnum &&
5961 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5962 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5963 			"numbers have changed");
5964 		journal_dev = new_decode_dev(journal_devnum);
5965 	} else
5966 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5967 
5968 	if (journal_inum && journal_dev) {
5969 		ext4_msg(sb, KERN_ERR,
5970 			 "filesystem has both journal inode and journal device!");
5971 		return -EINVAL;
5972 	}
5973 
5974 	if (journal_inum) {
5975 		journal = ext4_open_inode_journal(sb, journal_inum);
5976 		if (IS_ERR(journal))
5977 			return PTR_ERR(journal);
5978 	} else {
5979 		journal = ext4_open_dev_journal(sb, journal_dev);
5980 		if (IS_ERR(journal))
5981 			return PTR_ERR(journal);
5982 	}
5983 
5984 	journal_dev_ro = bdev_read_only(journal->j_dev);
5985 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5986 
5987 	if (journal_dev_ro && !sb_rdonly(sb)) {
5988 		ext4_msg(sb, KERN_ERR,
5989 			 "journal device read-only, try mounting with '-o ro'");
5990 		err = -EROFS;
5991 		goto err_out;
5992 	}
5993 
5994 	/*
5995 	 * Are we loading a blank journal or performing recovery after a
5996 	 * crash?  For recovery, we need to check in advance whether we
5997 	 * can get read-write access to the device.
5998 	 */
5999 	if (ext4_has_feature_journal_needs_recovery(sb)) {
6000 		if (sb_rdonly(sb)) {
6001 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
6002 					"required on readonly filesystem");
6003 			if (really_read_only) {
6004 				ext4_msg(sb, KERN_ERR, "write access "
6005 					"unavailable, cannot proceed "
6006 					"(try mounting with noload)");
6007 				err = -EROFS;
6008 				goto err_out;
6009 			}
6010 			ext4_msg(sb, KERN_INFO, "write access will "
6011 			       "be enabled during recovery");
6012 		}
6013 	}
6014 
6015 	if (!(journal->j_flags & JBD2_BARRIER))
6016 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6017 
6018 	if (!ext4_has_feature_journal_needs_recovery(sb))
6019 		err = jbd2_journal_wipe(journal, !really_read_only);
6020 	if (!err) {
6021 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6022 		__le16 orig_state;
6023 		bool changed = false;
6024 
6025 		if (save)
6026 			memcpy(save, ((char *) es) +
6027 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6028 		err = jbd2_journal_load(journal);
6029 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6030 				   save, EXT4_S_ERR_LEN)) {
6031 			memcpy(((char *) es) + EXT4_S_ERR_START,
6032 			       save, EXT4_S_ERR_LEN);
6033 			changed = true;
6034 		}
6035 		kfree(save);
6036 		orig_state = es->s_state;
6037 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6038 					   EXT4_ERROR_FS);
6039 		if (orig_state != es->s_state)
6040 			changed = true;
6041 		/* Write out restored error information to the superblock */
6042 		if (changed && !really_read_only) {
6043 			int err2;
6044 			err2 = ext4_commit_super(sb);
6045 			err = err ? : err2;
6046 		}
6047 	}
6048 
6049 	if (err) {
6050 		ext4_msg(sb, KERN_ERR, "error loading journal");
6051 		goto err_out;
6052 	}
6053 
6054 	EXT4_SB(sb)->s_journal = journal;
6055 	err = ext4_clear_journal_err(sb, es);
6056 	if (err) {
6057 		EXT4_SB(sb)->s_journal = NULL;
6058 		jbd2_journal_destroy(journal);
6059 		return err;
6060 	}
6061 
6062 	if (!really_read_only && journal_devnum &&
6063 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6064 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6065 		ext4_commit_super(sb);
6066 	}
6067 	if (!really_read_only && journal_inum &&
6068 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6069 		es->s_journal_inum = cpu_to_le32(journal_inum);
6070 		ext4_commit_super(sb);
6071 	}
6072 
6073 	return 0;
6074 
6075 err_out:
6076 	jbd2_journal_destroy(journal);
6077 	return err;
6078 }
6079 
6080 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6081 static void ext4_update_super(struct super_block *sb)
6082 {
6083 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6084 	struct ext4_super_block *es = sbi->s_es;
6085 	struct buffer_head *sbh = sbi->s_sbh;
6086 
6087 	lock_buffer(sbh);
6088 	/*
6089 	 * If the file system is mounted read-only, don't update the
6090 	 * superblock write time.  This avoids updating the superblock
6091 	 * write time when we are mounting the root file system
6092 	 * read/only but we need to replay the journal; at that point,
6093 	 * for people who are east of GMT and who make their clock
6094 	 * tick in localtime for Windows bug-for-bug compatibility,
6095 	 * the clock is set in the future, and this will cause e2fsck
6096 	 * to complain and force a full file system check.
6097 	 */
6098 	if (!sb_rdonly(sb))
6099 		ext4_update_tstamp(es, s_wtime);
6100 	es->s_kbytes_written =
6101 		cpu_to_le64(sbi->s_kbytes_written +
6102 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6103 		      sbi->s_sectors_written_start) >> 1));
6104 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6105 		ext4_free_blocks_count_set(es,
6106 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6107 				&sbi->s_freeclusters_counter)));
6108 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6109 		es->s_free_inodes_count =
6110 			cpu_to_le32(percpu_counter_sum_positive(
6111 				&sbi->s_freeinodes_counter));
6112 	/* Copy error information to the on-disk superblock */
6113 	spin_lock(&sbi->s_error_lock);
6114 	if (sbi->s_add_error_count > 0) {
6115 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6116 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6117 			__ext4_update_tstamp(&es->s_first_error_time,
6118 					     &es->s_first_error_time_hi,
6119 					     sbi->s_first_error_time);
6120 			strtomem_pad(es->s_first_error_func,
6121 				     sbi->s_first_error_func, 0);
6122 			es->s_first_error_line =
6123 				cpu_to_le32(sbi->s_first_error_line);
6124 			es->s_first_error_ino =
6125 				cpu_to_le32(sbi->s_first_error_ino);
6126 			es->s_first_error_block =
6127 				cpu_to_le64(sbi->s_first_error_block);
6128 			es->s_first_error_errcode =
6129 				ext4_errno_to_code(sbi->s_first_error_code);
6130 		}
6131 		__ext4_update_tstamp(&es->s_last_error_time,
6132 				     &es->s_last_error_time_hi,
6133 				     sbi->s_last_error_time);
6134 		strtomem_pad(es->s_last_error_func, sbi->s_last_error_func, 0);
6135 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6136 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6137 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6138 		es->s_last_error_errcode =
6139 				ext4_errno_to_code(sbi->s_last_error_code);
6140 		/*
6141 		 * Start the daily error reporting function if it hasn't been
6142 		 * started already
6143 		 */
6144 		if (!es->s_error_count)
6145 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6146 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6147 		sbi->s_add_error_count = 0;
6148 	}
6149 	spin_unlock(&sbi->s_error_lock);
6150 
6151 	ext4_superblock_csum_set(sb);
6152 	unlock_buffer(sbh);
6153 }
6154 
6155 static int ext4_commit_super(struct super_block *sb)
6156 {
6157 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6158 
6159 	if (!sbh)
6160 		return -EINVAL;
6161 
6162 	ext4_update_super(sb);
6163 
6164 	lock_buffer(sbh);
6165 	/* Buffer got discarded which means block device got invalidated */
6166 	if (!buffer_mapped(sbh)) {
6167 		unlock_buffer(sbh);
6168 		return -EIO;
6169 	}
6170 
6171 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6172 		/*
6173 		 * Oh, dear.  A previous attempt to write the
6174 		 * superblock failed.  This could happen because the
6175 		 * USB device was yanked out.  Or it could happen to
6176 		 * be a transient write error and maybe the block will
6177 		 * be remapped.  Nothing we can do but to retry the
6178 		 * write and hope for the best.
6179 		 */
6180 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6181 		       "superblock detected");
6182 		clear_buffer_write_io_error(sbh);
6183 		set_buffer_uptodate(sbh);
6184 	}
6185 	get_bh(sbh);
6186 	/* Clear potential dirty bit if it was journalled update */
6187 	clear_buffer_dirty(sbh);
6188 	sbh->b_end_io = end_buffer_write_sync;
6189 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6190 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6191 	wait_on_buffer(sbh);
6192 	if (buffer_write_io_error(sbh)) {
6193 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6194 		       "superblock");
6195 		clear_buffer_write_io_error(sbh);
6196 		set_buffer_uptodate(sbh);
6197 		return -EIO;
6198 	}
6199 	return 0;
6200 }
6201 
6202 /*
6203  * Have we just finished recovery?  If so, and if we are mounting (or
6204  * remounting) the filesystem readonly, then we will end up with a
6205  * consistent fs on disk.  Record that fact.
6206  */
6207 static int ext4_mark_recovery_complete(struct super_block *sb,
6208 				       struct ext4_super_block *es)
6209 {
6210 	int err;
6211 	journal_t *journal = EXT4_SB(sb)->s_journal;
6212 
6213 	if (!ext4_has_feature_journal(sb)) {
6214 		if (journal != NULL) {
6215 			ext4_error(sb, "Journal got removed while the fs was "
6216 				   "mounted!");
6217 			return -EFSCORRUPTED;
6218 		}
6219 		return 0;
6220 	}
6221 	jbd2_journal_lock_updates(journal);
6222 	err = jbd2_journal_flush(journal, 0);
6223 	if (err < 0)
6224 		goto out;
6225 
6226 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6227 	    ext4_has_feature_orphan_present(sb))) {
6228 		if (!ext4_orphan_file_empty(sb)) {
6229 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6230 			err = -EFSCORRUPTED;
6231 			goto out;
6232 		}
6233 		ext4_clear_feature_journal_needs_recovery(sb);
6234 		ext4_clear_feature_orphan_present(sb);
6235 		ext4_commit_super(sb);
6236 	}
6237 out:
6238 	jbd2_journal_unlock_updates(journal);
6239 	return err;
6240 }
6241 
6242 /*
6243  * If we are mounting (or read-write remounting) a filesystem whose journal
6244  * has recorded an error from a previous lifetime, move that error to the
6245  * main filesystem now.
6246  */
6247 static int ext4_clear_journal_err(struct super_block *sb,
6248 				   struct ext4_super_block *es)
6249 {
6250 	journal_t *journal;
6251 	int j_errno;
6252 	const char *errstr;
6253 
6254 	if (!ext4_has_feature_journal(sb)) {
6255 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6256 		return -EFSCORRUPTED;
6257 	}
6258 
6259 	journal = EXT4_SB(sb)->s_journal;
6260 
6261 	/*
6262 	 * Now check for any error status which may have been recorded in the
6263 	 * journal by a prior ext4_error() or ext4_abort()
6264 	 */
6265 
6266 	j_errno = jbd2_journal_errno(journal);
6267 	if (j_errno) {
6268 		char nbuf[16];
6269 
6270 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6271 		ext4_warning(sb, "Filesystem error recorded "
6272 			     "from previous mount: %s", errstr);
6273 
6274 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6275 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6276 		j_errno = ext4_commit_super(sb);
6277 		if (j_errno)
6278 			return j_errno;
6279 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6280 
6281 		jbd2_journal_clear_err(journal);
6282 		jbd2_journal_update_sb_errno(journal);
6283 	}
6284 	return 0;
6285 }
6286 
6287 /*
6288  * Force the running and committing transactions to commit,
6289  * and wait on the commit.
6290  */
6291 int ext4_force_commit(struct super_block *sb)
6292 {
6293 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6294 }
6295 
6296 static int ext4_sync_fs(struct super_block *sb, int wait)
6297 {
6298 	int ret = 0;
6299 	tid_t target;
6300 	bool needs_barrier = false;
6301 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6302 
6303 	if (unlikely(ext4_forced_shutdown(sb)))
6304 		return 0;
6305 
6306 	trace_ext4_sync_fs(sb, wait);
6307 	flush_workqueue(sbi->rsv_conversion_wq);
6308 	/*
6309 	 * Writeback quota in non-journalled quota case - journalled quota has
6310 	 * no dirty dquots
6311 	 */
6312 	dquot_writeback_dquots(sb, -1);
6313 	/*
6314 	 * Data writeback is possible w/o journal transaction, so barrier must
6315 	 * being sent at the end of the function. But we can skip it if
6316 	 * transaction_commit will do it for us.
6317 	 */
6318 	if (sbi->s_journal) {
6319 		target = jbd2_get_latest_transaction(sbi->s_journal);
6320 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6321 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6322 			needs_barrier = true;
6323 
6324 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6325 			if (wait)
6326 				ret = jbd2_log_wait_commit(sbi->s_journal,
6327 							   target);
6328 		}
6329 	} else if (wait && test_opt(sb, BARRIER))
6330 		needs_barrier = true;
6331 	if (needs_barrier) {
6332 		int err;
6333 		err = blkdev_issue_flush(sb->s_bdev);
6334 		if (!ret)
6335 			ret = err;
6336 	}
6337 
6338 	return ret;
6339 }
6340 
6341 /*
6342  * LVM calls this function before a (read-only) snapshot is created.  This
6343  * gives us a chance to flush the journal completely and mark the fs clean.
6344  *
6345  * Note that only this function cannot bring a filesystem to be in a clean
6346  * state independently. It relies on upper layer to stop all data & metadata
6347  * modifications.
6348  */
6349 static int ext4_freeze(struct super_block *sb)
6350 {
6351 	int error = 0;
6352 	journal_t *journal = EXT4_SB(sb)->s_journal;
6353 
6354 	if (journal) {
6355 		/* Now we set up the journal barrier. */
6356 		jbd2_journal_lock_updates(journal);
6357 
6358 		/*
6359 		 * Don't clear the needs_recovery flag if we failed to
6360 		 * flush the journal.
6361 		 */
6362 		error = jbd2_journal_flush(journal, 0);
6363 		if (error < 0)
6364 			goto out;
6365 
6366 		/* Journal blocked and flushed, clear needs_recovery flag. */
6367 		ext4_clear_feature_journal_needs_recovery(sb);
6368 		if (ext4_orphan_file_empty(sb))
6369 			ext4_clear_feature_orphan_present(sb);
6370 	}
6371 
6372 	error = ext4_commit_super(sb);
6373 out:
6374 	if (journal)
6375 		/* we rely on upper layer to stop further updates */
6376 		jbd2_journal_unlock_updates(journal);
6377 	return error;
6378 }
6379 
6380 /*
6381  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6382  * flag here, even though the filesystem is not technically dirty yet.
6383  */
6384 static int ext4_unfreeze(struct super_block *sb)
6385 {
6386 	if (ext4_forced_shutdown(sb))
6387 		return 0;
6388 
6389 	if (EXT4_SB(sb)->s_journal) {
6390 		/* Reset the needs_recovery flag before the fs is unlocked. */
6391 		ext4_set_feature_journal_needs_recovery(sb);
6392 		if (ext4_has_feature_orphan_file(sb))
6393 			ext4_set_feature_orphan_present(sb);
6394 	}
6395 
6396 	ext4_commit_super(sb);
6397 	return 0;
6398 }
6399 
6400 /*
6401  * Structure to save mount options for ext4_remount's benefit
6402  */
6403 struct ext4_mount_options {
6404 	unsigned long s_mount_opt;
6405 	unsigned long s_mount_opt2;
6406 	kuid_t s_resuid;
6407 	kgid_t s_resgid;
6408 	unsigned long s_commit_interval;
6409 	u32 s_min_batch_time, s_max_batch_time;
6410 #ifdef CONFIG_QUOTA
6411 	int s_jquota_fmt;
6412 	char *s_qf_names[EXT4_MAXQUOTAS];
6413 #endif
6414 };
6415 
6416 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6417 {
6418 	struct ext4_fs_context *ctx = fc->fs_private;
6419 	struct ext4_super_block *es;
6420 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6421 	unsigned long old_sb_flags;
6422 	struct ext4_mount_options old_opts;
6423 	ext4_group_t g;
6424 	int err = 0;
6425 	int alloc_ctx;
6426 #ifdef CONFIG_QUOTA
6427 	int enable_quota = 0;
6428 	int i, j;
6429 	char *to_free[EXT4_MAXQUOTAS];
6430 #endif
6431 
6432 
6433 	/* Store the original options */
6434 	old_sb_flags = sb->s_flags;
6435 	old_opts.s_mount_opt = sbi->s_mount_opt;
6436 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6437 	old_opts.s_resuid = sbi->s_resuid;
6438 	old_opts.s_resgid = sbi->s_resgid;
6439 	old_opts.s_commit_interval = sbi->s_commit_interval;
6440 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6441 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6442 #ifdef CONFIG_QUOTA
6443 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6444 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6445 		if (sbi->s_qf_names[i]) {
6446 			char *qf_name = get_qf_name(sb, sbi, i);
6447 
6448 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6449 			if (!old_opts.s_qf_names[i]) {
6450 				for (j = 0; j < i; j++)
6451 					kfree(old_opts.s_qf_names[j]);
6452 				return -ENOMEM;
6453 			}
6454 		} else
6455 			old_opts.s_qf_names[i] = NULL;
6456 #endif
6457 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6458 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6459 			ctx->journal_ioprio =
6460 				sbi->s_journal->j_task->io_context->ioprio;
6461 		else
6462 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6463 
6464 	}
6465 
6466 	if ((ctx->spec & EXT4_SPEC_s_stripe) &&
6467 	    ext4_is_stripe_incompatible(sb, ctx->s_stripe)) {
6468 		ext4_msg(sb, KERN_WARNING,
6469 			 "stripe (%lu) is not aligned with cluster size (%u), "
6470 			 "stripe is disabled",
6471 			 ctx->s_stripe, sbi->s_cluster_ratio);
6472 		ctx->s_stripe = 0;
6473 	}
6474 
6475 	/*
6476 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6477 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6478 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6479 	 * here s_writepages_rwsem to avoid race between writepages ops and
6480 	 * remount.
6481 	 */
6482 	alloc_ctx = ext4_writepages_down_write(sb);
6483 	ext4_apply_options(fc, sb);
6484 	ext4_writepages_up_write(sb, alloc_ctx);
6485 
6486 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6487 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6488 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6489 			 "during remount not supported; ignoring");
6490 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6491 	}
6492 
6493 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6494 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6495 			ext4_msg(sb, KERN_ERR, "can't mount with "
6496 				 "both data=journal and delalloc");
6497 			err = -EINVAL;
6498 			goto restore_opts;
6499 		}
6500 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6501 			ext4_msg(sb, KERN_ERR, "can't mount with "
6502 				 "both data=journal and dioread_nolock");
6503 			err = -EINVAL;
6504 			goto restore_opts;
6505 		}
6506 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6507 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6508 			ext4_msg(sb, KERN_ERR, "can't mount with "
6509 				"journal_async_commit in data=ordered mode");
6510 			err = -EINVAL;
6511 			goto restore_opts;
6512 		}
6513 	}
6514 
6515 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6516 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6517 		err = -EINVAL;
6518 		goto restore_opts;
6519 	}
6520 
6521 	if (test_opt2(sb, ABORT))
6522 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6523 
6524 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6525 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6526 
6527 	es = sbi->s_es;
6528 
6529 	if (sbi->s_journal) {
6530 		ext4_init_journal_params(sb, sbi->s_journal);
6531 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6532 	}
6533 
6534 	/* Flush outstanding errors before changing fs state */
6535 	flush_work(&sbi->s_sb_upd_work);
6536 
6537 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6538 		if (ext4_forced_shutdown(sb)) {
6539 			err = -EROFS;
6540 			goto restore_opts;
6541 		}
6542 
6543 		if (fc->sb_flags & SB_RDONLY) {
6544 			err = sync_filesystem(sb);
6545 			if (err < 0)
6546 				goto restore_opts;
6547 			err = dquot_suspend(sb, -1);
6548 			if (err < 0)
6549 				goto restore_opts;
6550 
6551 			/*
6552 			 * First of all, the unconditional stuff we have to do
6553 			 * to disable replay of the journal when we next remount
6554 			 */
6555 			sb->s_flags |= SB_RDONLY;
6556 
6557 			/*
6558 			 * OK, test if we are remounting a valid rw partition
6559 			 * readonly, and if so set the rdonly flag and then
6560 			 * mark the partition as valid again.
6561 			 */
6562 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6563 			    (sbi->s_mount_state & EXT4_VALID_FS))
6564 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6565 
6566 			if (sbi->s_journal) {
6567 				/*
6568 				 * We let remount-ro finish even if marking fs
6569 				 * as clean failed...
6570 				 */
6571 				ext4_mark_recovery_complete(sb, es);
6572 			}
6573 		} else {
6574 			/* Make sure we can mount this feature set readwrite */
6575 			if (ext4_has_feature_readonly(sb) ||
6576 			    !ext4_feature_set_ok(sb, 0)) {
6577 				err = -EROFS;
6578 				goto restore_opts;
6579 			}
6580 			/*
6581 			 * Make sure the group descriptor checksums
6582 			 * are sane.  If they aren't, refuse to remount r/w.
6583 			 */
6584 			for (g = 0; g < sbi->s_groups_count; g++) {
6585 				struct ext4_group_desc *gdp =
6586 					ext4_get_group_desc(sb, g, NULL);
6587 
6588 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6589 					ext4_msg(sb, KERN_ERR,
6590 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6591 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6592 					       le16_to_cpu(gdp->bg_checksum));
6593 					err = -EFSBADCRC;
6594 					goto restore_opts;
6595 				}
6596 			}
6597 
6598 			/*
6599 			 * If we have an unprocessed orphan list hanging
6600 			 * around from a previously readonly bdev mount,
6601 			 * require a full umount/remount for now.
6602 			 */
6603 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6604 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6605 				       "remount RDWR because of unprocessed "
6606 				       "orphan inode list.  Please "
6607 				       "umount/remount instead");
6608 				err = -EINVAL;
6609 				goto restore_opts;
6610 			}
6611 
6612 			/*
6613 			 * Mounting a RDONLY partition read-write, so reread
6614 			 * and store the current valid flag.  (It may have
6615 			 * been changed by e2fsck since we originally mounted
6616 			 * the partition.)
6617 			 */
6618 			if (sbi->s_journal) {
6619 				err = ext4_clear_journal_err(sb, es);
6620 				if (err)
6621 					goto restore_opts;
6622 			}
6623 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6624 					      ~EXT4_FC_REPLAY);
6625 
6626 			err = ext4_setup_super(sb, es, 0);
6627 			if (err)
6628 				goto restore_opts;
6629 
6630 			sb->s_flags &= ~SB_RDONLY;
6631 			if (ext4_has_feature_mmp(sb)) {
6632 				err = ext4_multi_mount_protect(sb,
6633 						le64_to_cpu(es->s_mmp_block));
6634 				if (err)
6635 					goto restore_opts;
6636 			}
6637 #ifdef CONFIG_QUOTA
6638 			enable_quota = 1;
6639 #endif
6640 		}
6641 	}
6642 
6643 	/*
6644 	 * Handle creation of system zone data early because it can fail.
6645 	 * Releasing of existing data is done when we are sure remount will
6646 	 * succeed.
6647 	 */
6648 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6649 		err = ext4_setup_system_zone(sb);
6650 		if (err)
6651 			goto restore_opts;
6652 	}
6653 
6654 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6655 		err = ext4_commit_super(sb);
6656 		if (err)
6657 			goto restore_opts;
6658 	}
6659 
6660 #ifdef CONFIG_QUOTA
6661 	if (enable_quota) {
6662 		if (sb_any_quota_suspended(sb))
6663 			dquot_resume(sb, -1);
6664 		else if (ext4_has_feature_quota(sb)) {
6665 			err = ext4_enable_quotas(sb);
6666 			if (err)
6667 				goto restore_opts;
6668 		}
6669 	}
6670 	/* Release old quota file names */
6671 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6672 		kfree(old_opts.s_qf_names[i]);
6673 #endif
6674 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6675 		ext4_release_system_zone(sb);
6676 
6677 	/*
6678 	 * Reinitialize lazy itable initialization thread based on
6679 	 * current settings
6680 	 */
6681 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6682 		ext4_unregister_li_request(sb);
6683 	else {
6684 		ext4_group_t first_not_zeroed;
6685 		first_not_zeroed = ext4_has_uninit_itable(sb);
6686 		ext4_register_li_request(sb, first_not_zeroed);
6687 	}
6688 
6689 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6690 		ext4_stop_mmpd(sbi);
6691 
6692 	return 0;
6693 
6694 restore_opts:
6695 	/*
6696 	 * If there was a failing r/w to ro transition, we may need to
6697 	 * re-enable quota
6698 	 */
6699 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6700 	    sb_any_quota_suspended(sb))
6701 		dquot_resume(sb, -1);
6702 
6703 	alloc_ctx = ext4_writepages_down_write(sb);
6704 	sb->s_flags = old_sb_flags;
6705 	sbi->s_mount_opt = old_opts.s_mount_opt;
6706 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6707 	sbi->s_resuid = old_opts.s_resuid;
6708 	sbi->s_resgid = old_opts.s_resgid;
6709 	sbi->s_commit_interval = old_opts.s_commit_interval;
6710 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6711 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6712 	ext4_writepages_up_write(sb, alloc_ctx);
6713 
6714 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6715 		ext4_release_system_zone(sb);
6716 #ifdef CONFIG_QUOTA
6717 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6718 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6719 		to_free[i] = get_qf_name(sb, sbi, i);
6720 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6721 	}
6722 	synchronize_rcu();
6723 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6724 		kfree(to_free[i]);
6725 #endif
6726 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6727 		ext4_stop_mmpd(sbi);
6728 	return err;
6729 }
6730 
6731 static int ext4_reconfigure(struct fs_context *fc)
6732 {
6733 	struct super_block *sb = fc->root->d_sb;
6734 	int ret;
6735 
6736 	fc->s_fs_info = EXT4_SB(sb);
6737 
6738 	ret = ext4_check_opt_consistency(fc, sb);
6739 	if (ret < 0)
6740 		return ret;
6741 
6742 	ret = __ext4_remount(fc, sb);
6743 	if (ret < 0)
6744 		return ret;
6745 
6746 	ext4_msg(sb, KERN_INFO, "re-mounted %pU %s. Quota mode: %s.",
6747 		 &sb->s_uuid, sb_rdonly(sb) ? "ro" : "r/w",
6748 		 ext4_quota_mode(sb));
6749 
6750 	return 0;
6751 }
6752 
6753 #ifdef CONFIG_QUOTA
6754 static int ext4_statfs_project(struct super_block *sb,
6755 			       kprojid_t projid, struct kstatfs *buf)
6756 {
6757 	struct kqid qid;
6758 	struct dquot *dquot;
6759 	u64 limit;
6760 	u64 curblock;
6761 
6762 	qid = make_kqid_projid(projid);
6763 	dquot = dqget(sb, qid);
6764 	if (IS_ERR(dquot))
6765 		return PTR_ERR(dquot);
6766 	spin_lock(&dquot->dq_dqb_lock);
6767 
6768 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6769 			     dquot->dq_dqb.dqb_bhardlimit);
6770 	limit >>= sb->s_blocksize_bits;
6771 
6772 	if (limit && buf->f_blocks > limit) {
6773 		curblock = (dquot->dq_dqb.dqb_curspace +
6774 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6775 		buf->f_blocks = limit;
6776 		buf->f_bfree = buf->f_bavail =
6777 			(buf->f_blocks > curblock) ?
6778 			 (buf->f_blocks - curblock) : 0;
6779 	}
6780 
6781 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6782 			     dquot->dq_dqb.dqb_ihardlimit);
6783 	if (limit && buf->f_files > limit) {
6784 		buf->f_files = limit;
6785 		buf->f_ffree =
6786 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6787 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6788 	}
6789 
6790 	spin_unlock(&dquot->dq_dqb_lock);
6791 	dqput(dquot);
6792 	return 0;
6793 }
6794 #endif
6795 
6796 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6797 {
6798 	struct super_block *sb = dentry->d_sb;
6799 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6800 	struct ext4_super_block *es = sbi->s_es;
6801 	ext4_fsblk_t overhead = 0, resv_blocks;
6802 	s64 bfree;
6803 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6804 
6805 	if (!test_opt(sb, MINIX_DF))
6806 		overhead = sbi->s_overhead;
6807 
6808 	buf->f_type = EXT4_SUPER_MAGIC;
6809 	buf->f_bsize = sb->s_blocksize;
6810 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6811 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6812 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6813 	/* prevent underflow in case that few free space is available */
6814 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6815 	buf->f_bavail = buf->f_bfree -
6816 			(ext4_r_blocks_count(es) + resv_blocks);
6817 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6818 		buf->f_bavail = 0;
6819 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6820 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6821 	buf->f_namelen = EXT4_NAME_LEN;
6822 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6823 
6824 #ifdef CONFIG_QUOTA
6825 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6826 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6827 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6828 #endif
6829 	return 0;
6830 }
6831 
6832 
6833 #ifdef CONFIG_QUOTA
6834 
6835 /*
6836  * Helper functions so that transaction is started before we acquire dqio_sem
6837  * to keep correct lock ordering of transaction > dqio_sem
6838  */
6839 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6840 {
6841 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6842 }
6843 
6844 static int ext4_write_dquot(struct dquot *dquot)
6845 {
6846 	int ret, err;
6847 	handle_t *handle;
6848 	struct inode *inode;
6849 
6850 	inode = dquot_to_inode(dquot);
6851 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6852 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6853 	if (IS_ERR(handle))
6854 		return PTR_ERR(handle);
6855 	ret = dquot_commit(dquot);
6856 	if (ret < 0)
6857 		ext4_error_err(dquot->dq_sb, -ret,
6858 			       "Failed to commit dquot type %d",
6859 			       dquot->dq_id.type);
6860 	err = ext4_journal_stop(handle);
6861 	if (!ret)
6862 		ret = err;
6863 	return ret;
6864 }
6865 
6866 static int ext4_acquire_dquot(struct dquot *dquot)
6867 {
6868 	int ret, err;
6869 	handle_t *handle;
6870 
6871 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6872 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6873 	if (IS_ERR(handle))
6874 		return PTR_ERR(handle);
6875 	ret = dquot_acquire(dquot);
6876 	if (ret < 0)
6877 		ext4_error_err(dquot->dq_sb, -ret,
6878 			      "Failed to acquire dquot type %d",
6879 			      dquot->dq_id.type);
6880 	err = ext4_journal_stop(handle);
6881 	if (!ret)
6882 		ret = err;
6883 	return ret;
6884 }
6885 
6886 static int ext4_release_dquot(struct dquot *dquot)
6887 {
6888 	int ret, err;
6889 	handle_t *handle;
6890 
6891 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6892 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6893 	if (IS_ERR(handle)) {
6894 		/* Release dquot anyway to avoid endless cycle in dqput() */
6895 		dquot_release(dquot);
6896 		return PTR_ERR(handle);
6897 	}
6898 	ret = dquot_release(dquot);
6899 	if (ret < 0)
6900 		ext4_error_err(dquot->dq_sb, -ret,
6901 			       "Failed to release dquot type %d",
6902 			       dquot->dq_id.type);
6903 	err = ext4_journal_stop(handle);
6904 	if (!ret)
6905 		ret = err;
6906 	return ret;
6907 }
6908 
6909 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6910 {
6911 	struct super_block *sb = dquot->dq_sb;
6912 
6913 	if (ext4_is_quota_journalled(sb)) {
6914 		dquot_mark_dquot_dirty(dquot);
6915 		return ext4_write_dquot(dquot);
6916 	} else {
6917 		return dquot_mark_dquot_dirty(dquot);
6918 	}
6919 }
6920 
6921 static int ext4_write_info(struct super_block *sb, int type)
6922 {
6923 	int ret, err;
6924 	handle_t *handle;
6925 
6926 	/* Data block + inode block */
6927 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6928 	if (IS_ERR(handle))
6929 		return PTR_ERR(handle);
6930 	ret = dquot_commit_info(sb, type);
6931 	err = ext4_journal_stop(handle);
6932 	if (!ret)
6933 		ret = err;
6934 	return ret;
6935 }
6936 
6937 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6938 {
6939 	struct ext4_inode_info *ei = EXT4_I(inode);
6940 
6941 	/* The first argument of lockdep_set_subclass has to be
6942 	 * *exactly* the same as the argument to init_rwsem() --- in
6943 	 * this case, in init_once() --- or lockdep gets unhappy
6944 	 * because the name of the lock is set using the
6945 	 * stringification of the argument to init_rwsem().
6946 	 */
6947 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6948 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6949 }
6950 
6951 /*
6952  * Standard function to be called on quota_on
6953  */
6954 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6955 			 const struct path *path)
6956 {
6957 	int err;
6958 
6959 	if (!test_opt(sb, QUOTA))
6960 		return -EINVAL;
6961 
6962 	/* Quotafile not on the same filesystem? */
6963 	if (path->dentry->d_sb != sb)
6964 		return -EXDEV;
6965 
6966 	/* Quota already enabled for this file? */
6967 	if (IS_NOQUOTA(d_inode(path->dentry)))
6968 		return -EBUSY;
6969 
6970 	/* Journaling quota? */
6971 	if (EXT4_SB(sb)->s_qf_names[type]) {
6972 		/* Quotafile not in fs root? */
6973 		if (path->dentry->d_parent != sb->s_root)
6974 			ext4_msg(sb, KERN_WARNING,
6975 				"Quota file not on filesystem root. "
6976 				"Journaled quota will not work");
6977 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6978 	} else {
6979 		/*
6980 		 * Clear the flag just in case mount options changed since
6981 		 * last time.
6982 		 */
6983 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6984 	}
6985 
6986 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6987 	err = dquot_quota_on(sb, type, format_id, path);
6988 	if (!err) {
6989 		struct inode *inode = d_inode(path->dentry);
6990 		handle_t *handle;
6991 
6992 		/*
6993 		 * Set inode flags to prevent userspace from messing with quota
6994 		 * files. If this fails, we return success anyway since quotas
6995 		 * are already enabled and this is not a hard failure.
6996 		 */
6997 		inode_lock(inode);
6998 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6999 		if (IS_ERR(handle))
7000 			goto unlock_inode;
7001 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
7002 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
7003 				S_NOATIME | S_IMMUTABLE);
7004 		err = ext4_mark_inode_dirty(handle, inode);
7005 		ext4_journal_stop(handle);
7006 	unlock_inode:
7007 		inode_unlock(inode);
7008 		if (err)
7009 			dquot_quota_off(sb, type);
7010 	}
7011 	if (err)
7012 		lockdep_set_quota_inode(path->dentry->d_inode,
7013 					     I_DATA_SEM_NORMAL);
7014 	return err;
7015 }
7016 
7017 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
7018 {
7019 	switch (type) {
7020 	case USRQUOTA:
7021 		return qf_inum == EXT4_USR_QUOTA_INO;
7022 	case GRPQUOTA:
7023 		return qf_inum == EXT4_GRP_QUOTA_INO;
7024 	case PRJQUOTA:
7025 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7026 	default:
7027 		BUG();
7028 	}
7029 }
7030 
7031 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7032 			     unsigned int flags)
7033 {
7034 	int err;
7035 	struct inode *qf_inode;
7036 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7037 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7038 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7039 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7040 	};
7041 
7042 	BUG_ON(!ext4_has_feature_quota(sb));
7043 
7044 	if (!qf_inums[type])
7045 		return -EPERM;
7046 
7047 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7048 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7049 				qf_inums[type], type);
7050 		return -EUCLEAN;
7051 	}
7052 
7053 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7054 	if (IS_ERR(qf_inode)) {
7055 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7056 				qf_inums[type], type);
7057 		return PTR_ERR(qf_inode);
7058 	}
7059 
7060 	/* Don't account quota for quota files to avoid recursion */
7061 	qf_inode->i_flags |= S_NOQUOTA;
7062 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7063 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7064 	if (err)
7065 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7066 	iput(qf_inode);
7067 
7068 	return err;
7069 }
7070 
7071 /* Enable usage tracking for all quota types. */
7072 int ext4_enable_quotas(struct super_block *sb)
7073 {
7074 	int type, err = 0;
7075 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7076 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7077 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7078 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7079 	};
7080 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7081 		test_opt(sb, USRQUOTA),
7082 		test_opt(sb, GRPQUOTA),
7083 		test_opt(sb, PRJQUOTA),
7084 	};
7085 
7086 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7087 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7088 		if (qf_inums[type]) {
7089 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7090 				DQUOT_USAGE_ENABLED |
7091 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7092 			if (err) {
7093 				ext4_warning(sb,
7094 					"Failed to enable quota tracking "
7095 					"(type=%d, err=%d, ino=%lu). "
7096 					"Please run e2fsck to fix.", type,
7097 					err, qf_inums[type]);
7098 
7099 				ext4_quotas_off(sb, type);
7100 				return err;
7101 			}
7102 		}
7103 	}
7104 	return 0;
7105 }
7106 
7107 static int ext4_quota_off(struct super_block *sb, int type)
7108 {
7109 	struct inode *inode = sb_dqopt(sb)->files[type];
7110 	handle_t *handle;
7111 	int err;
7112 
7113 	/* Force all delayed allocation blocks to be allocated.
7114 	 * Caller already holds s_umount sem */
7115 	if (test_opt(sb, DELALLOC))
7116 		sync_filesystem(sb);
7117 
7118 	if (!inode || !igrab(inode))
7119 		goto out;
7120 
7121 	err = dquot_quota_off(sb, type);
7122 	if (err || ext4_has_feature_quota(sb))
7123 		goto out_put;
7124 	/*
7125 	 * When the filesystem was remounted read-only first, we cannot cleanup
7126 	 * inode flags here. Bad luck but people should be using QUOTA feature
7127 	 * these days anyway.
7128 	 */
7129 	if (sb_rdonly(sb))
7130 		goto out_put;
7131 
7132 	inode_lock(inode);
7133 	/*
7134 	 * Update modification times of quota files when userspace can
7135 	 * start looking at them. If we fail, we return success anyway since
7136 	 * this is not a hard failure and quotas are already disabled.
7137 	 */
7138 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7139 	if (IS_ERR(handle)) {
7140 		err = PTR_ERR(handle);
7141 		goto out_unlock;
7142 	}
7143 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7144 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7145 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
7146 	err = ext4_mark_inode_dirty(handle, inode);
7147 	ext4_journal_stop(handle);
7148 out_unlock:
7149 	inode_unlock(inode);
7150 out_put:
7151 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7152 	iput(inode);
7153 	return err;
7154 out:
7155 	return dquot_quota_off(sb, type);
7156 }
7157 
7158 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7159  * acquiring the locks... As quota files are never truncated and quota code
7160  * itself serializes the operations (and no one else should touch the files)
7161  * we don't have to be afraid of races */
7162 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7163 			       size_t len, loff_t off)
7164 {
7165 	struct inode *inode = sb_dqopt(sb)->files[type];
7166 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7167 	int offset = off & (sb->s_blocksize - 1);
7168 	int tocopy;
7169 	size_t toread;
7170 	struct buffer_head *bh;
7171 	loff_t i_size = i_size_read(inode);
7172 
7173 	if (off > i_size)
7174 		return 0;
7175 	if (off+len > i_size)
7176 		len = i_size-off;
7177 	toread = len;
7178 	while (toread > 0) {
7179 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7180 		bh = ext4_bread(NULL, inode, blk, 0);
7181 		if (IS_ERR(bh))
7182 			return PTR_ERR(bh);
7183 		if (!bh)	/* A hole? */
7184 			memset(data, 0, tocopy);
7185 		else
7186 			memcpy(data, bh->b_data+offset, tocopy);
7187 		brelse(bh);
7188 		offset = 0;
7189 		toread -= tocopy;
7190 		data += tocopy;
7191 		blk++;
7192 	}
7193 	return len;
7194 }
7195 
7196 /* Write to quotafile (we know the transaction is already started and has
7197  * enough credits) */
7198 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7199 				const char *data, size_t len, loff_t off)
7200 {
7201 	struct inode *inode = sb_dqopt(sb)->files[type];
7202 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7203 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7204 	int retries = 0;
7205 	struct buffer_head *bh;
7206 	handle_t *handle = journal_current_handle();
7207 
7208 	if (!handle) {
7209 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7210 			" cancelled because transaction is not started",
7211 			(unsigned long long)off, (unsigned long long)len);
7212 		return -EIO;
7213 	}
7214 	/*
7215 	 * Since we account only one data block in transaction credits,
7216 	 * then it is impossible to cross a block boundary.
7217 	 */
7218 	if (sb->s_blocksize - offset < len) {
7219 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7220 			" cancelled because not block aligned",
7221 			(unsigned long long)off, (unsigned long long)len);
7222 		return -EIO;
7223 	}
7224 
7225 	do {
7226 		bh = ext4_bread(handle, inode, blk,
7227 				EXT4_GET_BLOCKS_CREATE |
7228 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7229 	} while (PTR_ERR(bh) == -ENOSPC &&
7230 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7231 	if (IS_ERR(bh))
7232 		return PTR_ERR(bh);
7233 	if (!bh)
7234 		goto out;
7235 	BUFFER_TRACE(bh, "get write access");
7236 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7237 	if (err) {
7238 		brelse(bh);
7239 		return err;
7240 	}
7241 	lock_buffer(bh);
7242 	memcpy(bh->b_data+offset, data, len);
7243 	flush_dcache_page(bh->b_page);
7244 	unlock_buffer(bh);
7245 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7246 	brelse(bh);
7247 out:
7248 	if (inode->i_size < off + len) {
7249 		i_size_write(inode, off + len);
7250 		EXT4_I(inode)->i_disksize = inode->i_size;
7251 		err2 = ext4_mark_inode_dirty(handle, inode);
7252 		if (unlikely(err2 && !err))
7253 			err = err2;
7254 	}
7255 	return err ? err : len;
7256 }
7257 #endif
7258 
7259 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7260 static inline void register_as_ext2(void)
7261 {
7262 	int err = register_filesystem(&ext2_fs_type);
7263 	if (err)
7264 		printk(KERN_WARNING
7265 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7266 }
7267 
7268 static inline void unregister_as_ext2(void)
7269 {
7270 	unregister_filesystem(&ext2_fs_type);
7271 }
7272 
7273 static inline int ext2_feature_set_ok(struct super_block *sb)
7274 {
7275 	if (ext4_has_unknown_ext2_incompat_features(sb))
7276 		return 0;
7277 	if (sb_rdonly(sb))
7278 		return 1;
7279 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7280 		return 0;
7281 	return 1;
7282 }
7283 #else
7284 static inline void register_as_ext2(void) { }
7285 static inline void unregister_as_ext2(void) { }
7286 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7287 #endif
7288 
7289 static inline void register_as_ext3(void)
7290 {
7291 	int err = register_filesystem(&ext3_fs_type);
7292 	if (err)
7293 		printk(KERN_WARNING
7294 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7295 }
7296 
7297 static inline void unregister_as_ext3(void)
7298 {
7299 	unregister_filesystem(&ext3_fs_type);
7300 }
7301 
7302 static inline int ext3_feature_set_ok(struct super_block *sb)
7303 {
7304 	if (ext4_has_unknown_ext3_incompat_features(sb))
7305 		return 0;
7306 	if (!ext4_has_feature_journal(sb))
7307 		return 0;
7308 	if (sb_rdonly(sb))
7309 		return 1;
7310 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7311 		return 0;
7312 	return 1;
7313 }
7314 
7315 static void ext4_kill_sb(struct super_block *sb)
7316 {
7317 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7318 	struct file *bdev_file = sbi ? sbi->s_journal_bdev_file : NULL;
7319 
7320 	kill_block_super(sb);
7321 
7322 	if (bdev_file)
7323 		bdev_fput(bdev_file);
7324 }
7325 
7326 static struct file_system_type ext4_fs_type = {
7327 	.owner			= THIS_MODULE,
7328 	.name			= "ext4",
7329 	.init_fs_context	= ext4_init_fs_context,
7330 	.parameters		= ext4_param_specs,
7331 	.kill_sb		= ext4_kill_sb,
7332 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7333 };
7334 MODULE_ALIAS_FS("ext4");
7335 
7336 /* Shared across all ext4 file systems */
7337 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7338 
7339 static int __init ext4_init_fs(void)
7340 {
7341 	int i, err;
7342 
7343 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7344 	ext4_li_info = NULL;
7345 
7346 	/* Build-time check for flags consistency */
7347 	ext4_check_flag_values();
7348 
7349 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7350 		init_waitqueue_head(&ext4__ioend_wq[i]);
7351 
7352 	err = ext4_init_es();
7353 	if (err)
7354 		return err;
7355 
7356 	err = ext4_init_pending();
7357 	if (err)
7358 		goto out7;
7359 
7360 	err = ext4_init_post_read_processing();
7361 	if (err)
7362 		goto out6;
7363 
7364 	err = ext4_init_pageio();
7365 	if (err)
7366 		goto out5;
7367 
7368 	err = ext4_init_system_zone();
7369 	if (err)
7370 		goto out4;
7371 
7372 	err = ext4_init_sysfs();
7373 	if (err)
7374 		goto out3;
7375 
7376 	err = ext4_init_mballoc();
7377 	if (err)
7378 		goto out2;
7379 	err = init_inodecache();
7380 	if (err)
7381 		goto out1;
7382 
7383 	err = ext4_fc_init_dentry_cache();
7384 	if (err)
7385 		goto out05;
7386 
7387 	register_as_ext3();
7388 	register_as_ext2();
7389 	err = register_filesystem(&ext4_fs_type);
7390 	if (err)
7391 		goto out;
7392 
7393 	return 0;
7394 out:
7395 	unregister_as_ext2();
7396 	unregister_as_ext3();
7397 	ext4_fc_destroy_dentry_cache();
7398 out05:
7399 	destroy_inodecache();
7400 out1:
7401 	ext4_exit_mballoc();
7402 out2:
7403 	ext4_exit_sysfs();
7404 out3:
7405 	ext4_exit_system_zone();
7406 out4:
7407 	ext4_exit_pageio();
7408 out5:
7409 	ext4_exit_post_read_processing();
7410 out6:
7411 	ext4_exit_pending();
7412 out7:
7413 	ext4_exit_es();
7414 
7415 	return err;
7416 }
7417 
7418 static void __exit ext4_exit_fs(void)
7419 {
7420 	ext4_destroy_lazyinit_thread();
7421 	unregister_as_ext2();
7422 	unregister_as_ext3();
7423 	unregister_filesystem(&ext4_fs_type);
7424 	ext4_fc_destroy_dentry_cache();
7425 	destroy_inodecache();
7426 	ext4_exit_mballoc();
7427 	ext4_exit_sysfs();
7428 	ext4_exit_system_zone();
7429 	ext4_exit_pageio();
7430 	ext4_exit_post_read_processing();
7431 	ext4_exit_es();
7432 	ext4_exit_pending();
7433 }
7434 
7435 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7436 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7437 MODULE_LICENSE("GPL");
7438 MODULE_SOFTDEP("pre: crc32c");
7439 module_init(ext4_init_fs)
7440 module_exit(ext4_exit_fs)
7441