xref: /linux/fs/ext4/super.c (revision 2697b79a469b68e3ad3640f55284359c1396278d)
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 	 * Make sure updated value of ->s_mount_flags will be visible before
739 	 * ->s_flags update
740 	 */
741 	smp_wmb();
742 	sb->s_flags |= SB_RDONLY;
743 }
744 
745 static void update_super_work(struct work_struct *work)
746 {
747 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
748 						s_sb_upd_work);
749 	journal_t *journal = sbi->s_journal;
750 	handle_t *handle;
751 
752 	/*
753 	 * If the journal is still running, we have to write out superblock
754 	 * through the journal to avoid collisions of other journalled sb
755 	 * updates.
756 	 *
757 	 * We use directly jbd2 functions here to avoid recursing back into
758 	 * ext4 error handling code during handling of previous errors.
759 	 */
760 	if (!sb_rdonly(sbi->s_sb) && journal) {
761 		struct buffer_head *sbh = sbi->s_sbh;
762 		bool call_notify_err = false;
763 
764 		handle = jbd2_journal_start(journal, 1);
765 		if (IS_ERR(handle))
766 			goto write_directly;
767 		if (jbd2_journal_get_write_access(handle, sbh)) {
768 			jbd2_journal_stop(handle);
769 			goto write_directly;
770 		}
771 
772 		if (sbi->s_add_error_count > 0)
773 			call_notify_err = true;
774 
775 		ext4_update_super(sbi->s_sb);
776 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
777 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
778 				 "superblock detected");
779 			clear_buffer_write_io_error(sbh);
780 			set_buffer_uptodate(sbh);
781 		}
782 
783 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
784 			jbd2_journal_stop(handle);
785 			goto write_directly;
786 		}
787 		jbd2_journal_stop(handle);
788 
789 		if (call_notify_err)
790 			ext4_notify_error_sysfs(sbi);
791 
792 		return;
793 	}
794 write_directly:
795 	/*
796 	 * Write through journal failed. Write sb directly to get error info
797 	 * out and hope for the best.
798 	 */
799 	ext4_commit_super(sbi->s_sb);
800 	ext4_notify_error_sysfs(sbi);
801 }
802 
803 #define ext4_error_ratelimit(sb)					\
804 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
805 			     "EXT4-fs error")
806 
807 void __ext4_error(struct super_block *sb, const char *function,
808 		  unsigned int line, bool force_ro, int error, __u64 block,
809 		  const char *fmt, ...)
810 {
811 	struct va_format vaf;
812 	va_list args;
813 
814 	if (unlikely(ext4_forced_shutdown(sb)))
815 		return;
816 
817 	trace_ext4_error(sb, function, line);
818 	if (ext4_error_ratelimit(sb)) {
819 		va_start(args, fmt);
820 		vaf.fmt = fmt;
821 		vaf.va = &args;
822 		printk(KERN_CRIT
823 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
824 		       sb->s_id, function, line, current->comm, &vaf);
825 		va_end(args);
826 	}
827 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
828 
829 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
830 }
831 
832 void __ext4_error_inode(struct inode *inode, const char *function,
833 			unsigned int line, ext4_fsblk_t block, int error,
834 			const char *fmt, ...)
835 {
836 	va_list args;
837 	struct va_format vaf;
838 
839 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
840 		return;
841 
842 	trace_ext4_error(inode->i_sb, function, line);
843 	if (ext4_error_ratelimit(inode->i_sb)) {
844 		va_start(args, fmt);
845 		vaf.fmt = fmt;
846 		vaf.va = &args;
847 		if (block)
848 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
849 			       "inode #%lu: block %llu: comm %s: %pV\n",
850 			       inode->i_sb->s_id, function, line, inode->i_ino,
851 			       block, current->comm, &vaf);
852 		else
853 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
854 			       "inode #%lu: comm %s: %pV\n",
855 			       inode->i_sb->s_id, function, line, inode->i_ino,
856 			       current->comm, &vaf);
857 		va_end(args);
858 	}
859 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
860 
861 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
862 			  function, line);
863 }
864 
865 void __ext4_error_file(struct file *file, const char *function,
866 		       unsigned int line, ext4_fsblk_t block,
867 		       const char *fmt, ...)
868 {
869 	va_list args;
870 	struct va_format vaf;
871 	struct inode *inode = file_inode(file);
872 	char pathname[80], *path;
873 
874 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
875 		return;
876 
877 	trace_ext4_error(inode->i_sb, function, line);
878 	if (ext4_error_ratelimit(inode->i_sb)) {
879 		path = file_path(file, pathname, sizeof(pathname));
880 		if (IS_ERR(path))
881 			path = "(unknown)";
882 		va_start(args, fmt);
883 		vaf.fmt = fmt;
884 		vaf.va = &args;
885 		if (block)
886 			printk(KERN_CRIT
887 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
888 			       "block %llu: comm %s: path %s: %pV\n",
889 			       inode->i_sb->s_id, function, line, inode->i_ino,
890 			       block, current->comm, path, &vaf);
891 		else
892 			printk(KERN_CRIT
893 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
894 			       "comm %s: path %s: %pV\n",
895 			       inode->i_sb->s_id, function, line, inode->i_ino,
896 			       current->comm, path, &vaf);
897 		va_end(args);
898 	}
899 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
900 
901 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
902 			  function, line);
903 }
904 
905 const char *ext4_decode_error(struct super_block *sb, int errno,
906 			      char nbuf[16])
907 {
908 	char *errstr = NULL;
909 
910 	switch (errno) {
911 	case -EFSCORRUPTED:
912 		errstr = "Corrupt filesystem";
913 		break;
914 	case -EFSBADCRC:
915 		errstr = "Filesystem failed CRC";
916 		break;
917 	case -EIO:
918 		errstr = "IO failure";
919 		break;
920 	case -ENOMEM:
921 		errstr = "Out of memory";
922 		break;
923 	case -EROFS:
924 		if (!sb || (EXT4_SB(sb)->s_journal &&
925 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
926 			errstr = "Journal has aborted";
927 		else
928 			errstr = "Readonly filesystem";
929 		break;
930 	default:
931 		/* If the caller passed in an extra buffer for unknown
932 		 * errors, textualise them now.  Else we just return
933 		 * NULL. */
934 		if (nbuf) {
935 			/* Check for truncated error codes... */
936 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
937 				errstr = nbuf;
938 		}
939 		break;
940 	}
941 
942 	return errstr;
943 }
944 
945 /* __ext4_std_error decodes expected errors from journaling functions
946  * automatically and invokes the appropriate error response.  */
947 
948 void __ext4_std_error(struct super_block *sb, const char *function,
949 		      unsigned int line, int errno)
950 {
951 	char nbuf[16];
952 	const char *errstr;
953 
954 	if (unlikely(ext4_forced_shutdown(sb)))
955 		return;
956 
957 	/* Special case: if the error is EROFS, and we're not already
958 	 * inside a transaction, then there's really no point in logging
959 	 * an error. */
960 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
961 		return;
962 
963 	if (ext4_error_ratelimit(sb)) {
964 		errstr = ext4_decode_error(sb, errno, nbuf);
965 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
966 		       sb->s_id, function, line, errstr);
967 	}
968 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
969 
970 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
971 }
972 
973 void __ext4_msg(struct super_block *sb,
974 		const char *prefix, const char *fmt, ...)
975 {
976 	struct va_format vaf;
977 	va_list args;
978 
979 	if (sb) {
980 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
981 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
982 				  "EXT4-fs"))
983 			return;
984 	}
985 
986 	va_start(args, fmt);
987 	vaf.fmt = fmt;
988 	vaf.va = &args;
989 	if (sb)
990 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
991 	else
992 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
993 	va_end(args);
994 }
995 
996 static int ext4_warning_ratelimit(struct super_block *sb)
997 {
998 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
999 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1000 			    "EXT4-fs warning");
1001 }
1002 
1003 void __ext4_warning(struct super_block *sb, const char *function,
1004 		    unsigned int line, const char *fmt, ...)
1005 {
1006 	struct va_format vaf;
1007 	va_list args;
1008 
1009 	if (!ext4_warning_ratelimit(sb))
1010 		return;
1011 
1012 	va_start(args, fmt);
1013 	vaf.fmt = fmt;
1014 	vaf.va = &args;
1015 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1016 	       sb->s_id, function, line, &vaf);
1017 	va_end(args);
1018 }
1019 
1020 void __ext4_warning_inode(const struct inode *inode, const char *function,
1021 			  unsigned int line, const char *fmt, ...)
1022 {
1023 	struct va_format vaf;
1024 	va_list args;
1025 
1026 	if (!ext4_warning_ratelimit(inode->i_sb))
1027 		return;
1028 
1029 	va_start(args, fmt);
1030 	vaf.fmt = fmt;
1031 	vaf.va = &args;
1032 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1033 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
1034 	       function, line, inode->i_ino, current->comm, &vaf);
1035 	va_end(args);
1036 }
1037 
1038 void __ext4_grp_locked_error(const char *function, unsigned int line,
1039 			     struct super_block *sb, ext4_group_t grp,
1040 			     unsigned long ino, ext4_fsblk_t block,
1041 			     const char *fmt, ...)
1042 __releases(bitlock)
1043 __acquires(bitlock)
1044 {
1045 	struct va_format vaf;
1046 	va_list args;
1047 
1048 	if (unlikely(ext4_forced_shutdown(sb)))
1049 		return;
1050 
1051 	trace_ext4_error(sb, function, line);
1052 	if (ext4_error_ratelimit(sb)) {
1053 		va_start(args, fmt);
1054 		vaf.fmt = fmt;
1055 		vaf.va = &args;
1056 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1057 		       sb->s_id, function, line, grp);
1058 		if (ino)
1059 			printk(KERN_CONT "inode %lu: ", ino);
1060 		if (block)
1061 			printk(KERN_CONT "block %llu:",
1062 			       (unsigned long long) block);
1063 		printk(KERN_CONT "%pV\n", &vaf);
1064 		va_end(args);
1065 	}
1066 
1067 	if (test_opt(sb, ERRORS_CONT)) {
1068 		if (test_opt(sb, WARN_ON_ERROR))
1069 			WARN_ON_ONCE(1);
1070 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1071 		if (!bdev_read_only(sb->s_bdev)) {
1072 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1073 					line);
1074 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1075 		}
1076 		return;
1077 	}
1078 	ext4_unlock_group(sb, grp);
1079 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1080 	/*
1081 	 * We only get here in the ERRORS_RO case; relocking the group
1082 	 * may be dangerous, but nothing bad will happen since the
1083 	 * filesystem will have already been marked read/only and the
1084 	 * journal has been aborted.  We return 1 as a hint to callers
1085 	 * who might what to use the return value from
1086 	 * ext4_grp_locked_error() to distinguish between the
1087 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1088 	 * aggressively from the ext4 function in question, with a
1089 	 * more appropriate error code.
1090 	 */
1091 	ext4_lock_group(sb, grp);
1092 	return;
1093 }
1094 
1095 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1096 				     ext4_group_t group,
1097 				     unsigned int flags)
1098 {
1099 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1100 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1101 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1102 	int ret;
1103 
1104 	if (!grp || !gdp)
1105 		return;
1106 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1107 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1108 					    &grp->bb_state);
1109 		if (!ret)
1110 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1111 					   grp->bb_free);
1112 	}
1113 
1114 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1115 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1116 					    &grp->bb_state);
1117 		if (!ret && gdp) {
1118 			int count;
1119 
1120 			count = ext4_free_inodes_count(sb, gdp);
1121 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1122 					   count);
1123 		}
1124 	}
1125 }
1126 
1127 void ext4_update_dynamic_rev(struct super_block *sb)
1128 {
1129 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1130 
1131 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1132 		return;
1133 
1134 	ext4_warning(sb,
1135 		     "updating to rev %d because of new feature flag, "
1136 		     "running e2fsck is recommended",
1137 		     EXT4_DYNAMIC_REV);
1138 
1139 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1140 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1141 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1142 	/* leave es->s_feature_*compat flags alone */
1143 	/* es->s_uuid will be set by e2fsck if empty */
1144 
1145 	/*
1146 	 * The rest of the superblock fields should be zero, and if not it
1147 	 * means they are likely already in use, so leave them alone.  We
1148 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1149 	 */
1150 }
1151 
1152 static inline struct inode *orphan_list_entry(struct list_head *l)
1153 {
1154 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1155 }
1156 
1157 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1158 {
1159 	struct list_head *l;
1160 
1161 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1162 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1163 
1164 	printk(KERN_ERR "sb_info orphan list:\n");
1165 	list_for_each(l, &sbi->s_orphan) {
1166 		struct inode *inode = orphan_list_entry(l);
1167 		printk(KERN_ERR "  "
1168 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1169 		       inode->i_sb->s_id, inode->i_ino, inode,
1170 		       inode->i_mode, inode->i_nlink,
1171 		       NEXT_ORPHAN(inode));
1172 	}
1173 }
1174 
1175 #ifdef CONFIG_QUOTA
1176 static int ext4_quota_off(struct super_block *sb, int type);
1177 
1178 static inline void ext4_quotas_off(struct super_block *sb, int type)
1179 {
1180 	BUG_ON(type > EXT4_MAXQUOTAS);
1181 
1182 	/* Use our quota_off function to clear inode flags etc. */
1183 	for (type--; type >= 0; type--)
1184 		ext4_quota_off(sb, type);
1185 }
1186 
1187 /*
1188  * This is a helper function which is used in the mount/remount
1189  * codepaths (which holds s_umount) to fetch the quota file name.
1190  */
1191 static inline char *get_qf_name(struct super_block *sb,
1192 				struct ext4_sb_info *sbi,
1193 				int type)
1194 {
1195 	return rcu_dereference_protected(sbi->s_qf_names[type],
1196 					 lockdep_is_held(&sb->s_umount));
1197 }
1198 #else
1199 static inline void ext4_quotas_off(struct super_block *sb, int type)
1200 {
1201 }
1202 #endif
1203 
1204 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1205 {
1206 	ext4_fsblk_t block;
1207 	int err;
1208 
1209 	block = ext4_count_free_clusters(sbi->s_sb);
1210 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1211 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1212 				  GFP_KERNEL);
1213 	if (!err) {
1214 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1215 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1216 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1217 					  GFP_KERNEL);
1218 	}
1219 	if (!err)
1220 		err = percpu_counter_init(&sbi->s_dirs_counter,
1221 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1222 	if (!err)
1223 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1224 					  GFP_KERNEL);
1225 	if (!err)
1226 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1227 					  GFP_KERNEL);
1228 	if (!err)
1229 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1230 
1231 	if (err)
1232 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1233 
1234 	return err;
1235 }
1236 
1237 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1238 {
1239 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1240 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1241 	percpu_counter_destroy(&sbi->s_dirs_counter);
1242 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1243 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1244 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1245 }
1246 
1247 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1248 {
1249 	struct buffer_head **group_desc;
1250 	int i;
1251 
1252 	rcu_read_lock();
1253 	group_desc = rcu_dereference(sbi->s_group_desc);
1254 	for (i = 0; i < sbi->s_gdb_count; i++)
1255 		brelse(group_desc[i]);
1256 	kvfree(group_desc);
1257 	rcu_read_unlock();
1258 }
1259 
1260 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1261 {
1262 	struct flex_groups **flex_groups;
1263 	int i;
1264 
1265 	rcu_read_lock();
1266 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1267 	if (flex_groups) {
1268 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1269 			kvfree(flex_groups[i]);
1270 		kvfree(flex_groups);
1271 	}
1272 	rcu_read_unlock();
1273 }
1274 
1275 static void ext4_put_super(struct super_block *sb)
1276 {
1277 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1278 	struct ext4_super_block *es = sbi->s_es;
1279 	int aborted = 0;
1280 	int err;
1281 
1282 	/*
1283 	 * Unregister sysfs before destroying jbd2 journal.
1284 	 * Since we could still access attr_journal_task attribute via sysfs
1285 	 * path which could have sbi->s_journal->j_task as NULL
1286 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1287 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1288 	 * read metadata verify failed then will queue error work.
1289 	 * update_super_work will call start_this_handle may trigger
1290 	 * BUG_ON.
1291 	 */
1292 	ext4_unregister_sysfs(sb);
1293 
1294 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1295 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1296 			 &sb->s_uuid);
1297 
1298 	ext4_unregister_li_request(sb);
1299 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1300 
1301 	flush_work(&sbi->s_sb_upd_work);
1302 	destroy_workqueue(sbi->rsv_conversion_wq);
1303 	ext4_release_orphan_info(sb);
1304 
1305 	if (sbi->s_journal) {
1306 		aborted = is_journal_aborted(sbi->s_journal);
1307 		err = jbd2_journal_destroy(sbi->s_journal);
1308 		sbi->s_journal = NULL;
1309 		if ((err < 0) && !aborted) {
1310 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1311 		}
1312 	}
1313 
1314 	ext4_es_unregister_shrinker(sbi);
1315 	timer_shutdown_sync(&sbi->s_err_report);
1316 	ext4_release_system_zone(sb);
1317 	ext4_mb_release(sb);
1318 	ext4_ext_release(sb);
1319 
1320 	if (!sb_rdonly(sb) && !aborted) {
1321 		ext4_clear_feature_journal_needs_recovery(sb);
1322 		ext4_clear_feature_orphan_present(sb);
1323 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1324 	}
1325 	if (!sb_rdonly(sb))
1326 		ext4_commit_super(sb);
1327 
1328 	ext4_group_desc_free(sbi);
1329 	ext4_flex_groups_free(sbi);
1330 	ext4_percpu_param_destroy(sbi);
1331 #ifdef CONFIG_QUOTA
1332 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1333 		kfree(get_qf_name(sb, sbi, i));
1334 #endif
1335 
1336 	/* Debugging code just in case the in-memory inode orphan list
1337 	 * isn't empty.  The on-disk one can be non-empty if we've
1338 	 * detected an error and taken the fs readonly, but the
1339 	 * in-memory list had better be clean by this point. */
1340 	if (!list_empty(&sbi->s_orphan))
1341 		dump_orphan_list(sb, sbi);
1342 	ASSERT(list_empty(&sbi->s_orphan));
1343 
1344 	sync_blockdev(sb->s_bdev);
1345 	invalidate_bdev(sb->s_bdev);
1346 	if (sbi->s_journal_bdev_file) {
1347 		/*
1348 		 * Invalidate the journal device's buffers.  We don't want them
1349 		 * floating about in memory - the physical journal device may
1350 		 * hotswapped, and it breaks the `ro-after' testing code.
1351 		 */
1352 		sync_blockdev(file_bdev(sbi->s_journal_bdev_file));
1353 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
1354 	}
1355 
1356 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1357 	sbi->s_ea_inode_cache = NULL;
1358 
1359 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1360 	sbi->s_ea_block_cache = NULL;
1361 
1362 	ext4_stop_mmpd(sbi);
1363 
1364 	brelse(sbi->s_sbh);
1365 	sb->s_fs_info = NULL;
1366 	/*
1367 	 * Now that we are completely done shutting down the
1368 	 * superblock, we need to actually destroy the kobject.
1369 	 */
1370 	kobject_put(&sbi->s_kobj);
1371 	wait_for_completion(&sbi->s_kobj_unregister);
1372 	if (sbi->s_chksum_driver)
1373 		crypto_free_shash(sbi->s_chksum_driver);
1374 	kfree(sbi->s_blockgroup_lock);
1375 	fs_put_dax(sbi->s_daxdev, NULL);
1376 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1377 #if IS_ENABLED(CONFIG_UNICODE)
1378 	utf8_unload(sb->s_encoding);
1379 #endif
1380 	kfree(sbi);
1381 }
1382 
1383 static struct kmem_cache *ext4_inode_cachep;
1384 
1385 /*
1386  * Called inside transaction, so use GFP_NOFS
1387  */
1388 static struct inode *ext4_alloc_inode(struct super_block *sb)
1389 {
1390 	struct ext4_inode_info *ei;
1391 
1392 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1393 	if (!ei)
1394 		return NULL;
1395 
1396 	inode_set_iversion(&ei->vfs_inode, 1);
1397 	ei->i_flags = 0;
1398 	spin_lock_init(&ei->i_raw_lock);
1399 	ei->i_prealloc_node = RB_ROOT;
1400 	atomic_set(&ei->i_prealloc_active, 0);
1401 	rwlock_init(&ei->i_prealloc_lock);
1402 	ext4_es_init_tree(&ei->i_es_tree);
1403 	rwlock_init(&ei->i_es_lock);
1404 	INIT_LIST_HEAD(&ei->i_es_list);
1405 	ei->i_es_all_nr = 0;
1406 	ei->i_es_shk_nr = 0;
1407 	ei->i_es_shrink_lblk = 0;
1408 	ei->i_reserved_data_blocks = 0;
1409 	spin_lock_init(&(ei->i_block_reservation_lock));
1410 	ext4_init_pending_tree(&ei->i_pending_tree);
1411 #ifdef CONFIG_QUOTA
1412 	ei->i_reserved_quota = 0;
1413 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1414 #endif
1415 	ei->jinode = NULL;
1416 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1417 	spin_lock_init(&ei->i_completed_io_lock);
1418 	ei->i_sync_tid = 0;
1419 	ei->i_datasync_tid = 0;
1420 	atomic_set(&ei->i_unwritten, 0);
1421 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1422 	ext4_fc_init_inode(&ei->vfs_inode);
1423 	mutex_init(&ei->i_fc_lock);
1424 	return &ei->vfs_inode;
1425 }
1426 
1427 static int ext4_drop_inode(struct inode *inode)
1428 {
1429 	int drop = generic_drop_inode(inode);
1430 
1431 	if (!drop)
1432 		drop = fscrypt_drop_inode(inode);
1433 
1434 	trace_ext4_drop_inode(inode, drop);
1435 	return drop;
1436 }
1437 
1438 static void ext4_free_in_core_inode(struct inode *inode)
1439 {
1440 	fscrypt_free_inode(inode);
1441 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1442 		pr_warn("%s: inode %ld still in fc list",
1443 			__func__, inode->i_ino);
1444 	}
1445 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1446 }
1447 
1448 static void ext4_destroy_inode(struct inode *inode)
1449 {
1450 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1451 		ext4_msg(inode->i_sb, KERN_ERR,
1452 			 "Inode %lu (%p): orphan list check failed!",
1453 			 inode->i_ino, EXT4_I(inode));
1454 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1455 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1456 				true);
1457 		dump_stack();
1458 	}
1459 
1460 	if (EXT4_I(inode)->i_reserved_data_blocks)
1461 		ext4_msg(inode->i_sb, KERN_ERR,
1462 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1463 			 inode->i_ino, EXT4_I(inode),
1464 			 EXT4_I(inode)->i_reserved_data_blocks);
1465 }
1466 
1467 static void ext4_shutdown(struct super_block *sb)
1468 {
1469        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1470 }
1471 
1472 static void init_once(void *foo)
1473 {
1474 	struct ext4_inode_info *ei = foo;
1475 
1476 	INIT_LIST_HEAD(&ei->i_orphan);
1477 	init_rwsem(&ei->xattr_sem);
1478 	init_rwsem(&ei->i_data_sem);
1479 	inode_init_once(&ei->vfs_inode);
1480 	ext4_fc_init_inode(&ei->vfs_inode);
1481 }
1482 
1483 static int __init init_inodecache(void)
1484 {
1485 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1486 				sizeof(struct ext4_inode_info), 0,
1487 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
1488 				offsetof(struct ext4_inode_info, i_data),
1489 				sizeof_field(struct ext4_inode_info, i_data),
1490 				init_once);
1491 	if (ext4_inode_cachep == NULL)
1492 		return -ENOMEM;
1493 	return 0;
1494 }
1495 
1496 static void destroy_inodecache(void)
1497 {
1498 	/*
1499 	 * Make sure all delayed rcu free inodes are flushed before we
1500 	 * destroy cache.
1501 	 */
1502 	rcu_barrier();
1503 	kmem_cache_destroy(ext4_inode_cachep);
1504 }
1505 
1506 void ext4_clear_inode(struct inode *inode)
1507 {
1508 	ext4_fc_del(inode);
1509 	invalidate_inode_buffers(inode);
1510 	clear_inode(inode);
1511 	ext4_discard_preallocations(inode);
1512 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1513 	dquot_drop(inode);
1514 	if (EXT4_I(inode)->jinode) {
1515 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1516 					       EXT4_I(inode)->jinode);
1517 		jbd2_free_inode(EXT4_I(inode)->jinode);
1518 		EXT4_I(inode)->jinode = NULL;
1519 	}
1520 	fscrypt_put_encryption_info(inode);
1521 	fsverity_cleanup_inode(inode);
1522 }
1523 
1524 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1525 					u64 ino, u32 generation)
1526 {
1527 	struct inode *inode;
1528 
1529 	/*
1530 	 * Currently we don't know the generation for parent directory, so
1531 	 * a generation of 0 means "accept any"
1532 	 */
1533 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1534 	if (IS_ERR(inode))
1535 		return ERR_CAST(inode);
1536 	if (generation && inode->i_generation != generation) {
1537 		iput(inode);
1538 		return ERR_PTR(-ESTALE);
1539 	}
1540 
1541 	return inode;
1542 }
1543 
1544 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1545 					int fh_len, int fh_type)
1546 {
1547 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1548 				    ext4_nfs_get_inode);
1549 }
1550 
1551 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1552 					int fh_len, int fh_type)
1553 {
1554 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1555 				    ext4_nfs_get_inode);
1556 }
1557 
1558 static int ext4_nfs_commit_metadata(struct inode *inode)
1559 {
1560 	struct writeback_control wbc = {
1561 		.sync_mode = WB_SYNC_ALL
1562 	};
1563 
1564 	trace_ext4_nfs_commit_metadata(inode);
1565 	return ext4_write_inode(inode, &wbc);
1566 }
1567 
1568 #ifdef CONFIG_QUOTA
1569 static const char * const quotatypes[] = INITQFNAMES;
1570 #define QTYPE2NAME(t) (quotatypes[t])
1571 
1572 static int ext4_write_dquot(struct dquot *dquot);
1573 static int ext4_acquire_dquot(struct dquot *dquot);
1574 static int ext4_release_dquot(struct dquot *dquot);
1575 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1576 static int ext4_write_info(struct super_block *sb, int type);
1577 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1578 			 const struct path *path);
1579 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1580 			       size_t len, loff_t off);
1581 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1582 				const char *data, size_t len, loff_t off);
1583 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1584 			     unsigned int flags);
1585 
1586 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1587 {
1588 	return EXT4_I(inode)->i_dquot;
1589 }
1590 
1591 static const struct dquot_operations ext4_quota_operations = {
1592 	.get_reserved_space	= ext4_get_reserved_space,
1593 	.write_dquot		= ext4_write_dquot,
1594 	.acquire_dquot		= ext4_acquire_dquot,
1595 	.release_dquot		= ext4_release_dquot,
1596 	.mark_dirty		= ext4_mark_dquot_dirty,
1597 	.write_info		= ext4_write_info,
1598 	.alloc_dquot		= dquot_alloc,
1599 	.destroy_dquot		= dquot_destroy,
1600 	.get_projid		= ext4_get_projid,
1601 	.get_inode_usage	= ext4_get_inode_usage,
1602 	.get_next_id		= dquot_get_next_id,
1603 };
1604 
1605 static const struct quotactl_ops ext4_qctl_operations = {
1606 	.quota_on	= ext4_quota_on,
1607 	.quota_off	= ext4_quota_off,
1608 	.quota_sync	= dquot_quota_sync,
1609 	.get_state	= dquot_get_state,
1610 	.set_info	= dquot_set_dqinfo,
1611 	.get_dqblk	= dquot_get_dqblk,
1612 	.set_dqblk	= dquot_set_dqblk,
1613 	.get_nextdqblk	= dquot_get_next_dqblk,
1614 };
1615 #endif
1616 
1617 static const struct super_operations ext4_sops = {
1618 	.alloc_inode	= ext4_alloc_inode,
1619 	.free_inode	= ext4_free_in_core_inode,
1620 	.destroy_inode	= ext4_destroy_inode,
1621 	.write_inode	= ext4_write_inode,
1622 	.dirty_inode	= ext4_dirty_inode,
1623 	.drop_inode	= ext4_drop_inode,
1624 	.evict_inode	= ext4_evict_inode,
1625 	.put_super	= ext4_put_super,
1626 	.sync_fs	= ext4_sync_fs,
1627 	.freeze_fs	= ext4_freeze,
1628 	.unfreeze_fs	= ext4_unfreeze,
1629 	.statfs		= ext4_statfs,
1630 	.show_options	= ext4_show_options,
1631 	.shutdown	= ext4_shutdown,
1632 #ifdef CONFIG_QUOTA
1633 	.quota_read	= ext4_quota_read,
1634 	.quota_write	= ext4_quota_write,
1635 	.get_dquots	= ext4_get_dquots,
1636 #endif
1637 };
1638 
1639 static const struct export_operations ext4_export_ops = {
1640 	.encode_fh = generic_encode_ino32_fh,
1641 	.fh_to_dentry = ext4_fh_to_dentry,
1642 	.fh_to_parent = ext4_fh_to_parent,
1643 	.get_parent = ext4_get_parent,
1644 	.commit_metadata = ext4_nfs_commit_metadata,
1645 };
1646 
1647 enum {
1648 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1649 	Opt_resgid, Opt_resuid, Opt_sb,
1650 	Opt_nouid32, Opt_debug, Opt_removed,
1651 	Opt_user_xattr, Opt_acl,
1652 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1653 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1654 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1655 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1656 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1657 	Opt_inlinecrypt,
1658 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1659 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1660 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1661 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1662 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1663 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1664 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1665 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1666 	Opt_dioread_nolock, Opt_dioread_lock,
1667 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1668 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1669 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1670 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1671 #ifdef CONFIG_EXT4_DEBUG
1672 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1673 #endif
1674 };
1675 
1676 static const struct constant_table ext4_param_errors[] = {
1677 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1678 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1679 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1680 	{}
1681 };
1682 
1683 static const struct constant_table ext4_param_data[] = {
1684 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1685 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1686 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1687 	{}
1688 };
1689 
1690 static const struct constant_table ext4_param_data_err[] = {
1691 	{"abort",	Opt_data_err_abort},
1692 	{"ignore",	Opt_data_err_ignore},
1693 	{}
1694 };
1695 
1696 static const struct constant_table ext4_param_jqfmt[] = {
1697 	{"vfsold",	QFMT_VFS_OLD},
1698 	{"vfsv0",	QFMT_VFS_V0},
1699 	{"vfsv1",	QFMT_VFS_V1},
1700 	{}
1701 };
1702 
1703 static const struct constant_table ext4_param_dax[] = {
1704 	{"always",	Opt_dax_always},
1705 	{"inode",	Opt_dax_inode},
1706 	{"never",	Opt_dax_never},
1707 	{}
1708 };
1709 
1710 /*
1711  * Mount option specification
1712  * We don't use fsparam_flag_no because of the way we set the
1713  * options and the way we show them in _ext4_show_options(). To
1714  * keep the changes to a minimum, let's keep the negative options
1715  * separate for now.
1716  */
1717 static const struct fs_parameter_spec ext4_param_specs[] = {
1718 	fsparam_flag	("bsddf",		Opt_bsd_df),
1719 	fsparam_flag	("minixdf",		Opt_minix_df),
1720 	fsparam_flag	("grpid",		Opt_grpid),
1721 	fsparam_flag	("bsdgroups",		Opt_grpid),
1722 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1723 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1724 	fsparam_u32	("resgid",		Opt_resgid),
1725 	fsparam_u32	("resuid",		Opt_resuid),
1726 	fsparam_u32	("sb",			Opt_sb),
1727 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1728 	fsparam_flag	("nouid32",		Opt_nouid32),
1729 	fsparam_flag	("debug",		Opt_debug),
1730 	fsparam_flag	("oldalloc",		Opt_removed),
1731 	fsparam_flag	("orlov",		Opt_removed),
1732 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1733 	fsparam_flag	("acl",			Opt_acl),
1734 	fsparam_flag	("norecovery",		Opt_noload),
1735 	fsparam_flag	("noload",		Opt_noload),
1736 	fsparam_flag	("bh",			Opt_removed),
1737 	fsparam_flag	("nobh",		Opt_removed),
1738 	fsparam_u32	("commit",		Opt_commit),
1739 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1740 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1741 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1742 	fsparam_bdev	("journal_path",	Opt_journal_path),
1743 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1744 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1745 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1746 	fsparam_flag	("abort",		Opt_abort),
1747 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1748 	fsparam_enum	("data_err",		Opt_data_err,
1749 						ext4_param_data_err),
1750 	fsparam_string_empty
1751 			("usrjquota",		Opt_usrjquota),
1752 	fsparam_string_empty
1753 			("grpjquota",		Opt_grpjquota),
1754 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1755 	fsparam_flag	("grpquota",		Opt_grpquota),
1756 	fsparam_flag	("quota",		Opt_quota),
1757 	fsparam_flag	("noquota",		Opt_noquota),
1758 	fsparam_flag	("usrquota",		Opt_usrquota),
1759 	fsparam_flag	("prjquota",		Opt_prjquota),
1760 	fsparam_flag	("barrier",		Opt_barrier),
1761 	fsparam_u32	("barrier",		Opt_barrier),
1762 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1763 	fsparam_flag	("i_version",		Opt_removed),
1764 	fsparam_flag	("dax",			Opt_dax),
1765 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1766 	fsparam_u32	("stripe",		Opt_stripe),
1767 	fsparam_flag	("delalloc",		Opt_delalloc),
1768 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1769 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1770 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1771 	fsparam_u32	("debug_want_extra_isize",
1772 						Opt_debug_want_extra_isize),
1773 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1774 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1775 	fsparam_flag	("block_validity",	Opt_block_validity),
1776 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1777 	fsparam_u32	("inode_readahead_blks",
1778 						Opt_inode_readahead_blks),
1779 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1780 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1781 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1782 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1783 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1784 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1785 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1786 	fsparam_flag	("discard",		Opt_discard),
1787 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1788 	fsparam_u32	("init_itable",		Opt_init_itable),
1789 	fsparam_flag	("init_itable",		Opt_init_itable),
1790 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1791 #ifdef CONFIG_EXT4_DEBUG
1792 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1793 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1794 #endif
1795 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1796 	fsparam_flag	("test_dummy_encryption",
1797 						Opt_test_dummy_encryption),
1798 	fsparam_string	("test_dummy_encryption",
1799 						Opt_test_dummy_encryption),
1800 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1801 	fsparam_flag	("nombcache",		Opt_nombcache),
1802 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1803 	fsparam_flag	("prefetch_block_bitmaps",
1804 						Opt_removed),
1805 	fsparam_flag	("no_prefetch_block_bitmaps",
1806 						Opt_no_prefetch_block_bitmaps),
1807 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1808 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1809 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1810 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1811 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1812 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1813 	{}
1814 };
1815 
1816 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1817 
1818 #define MOPT_SET	0x0001
1819 #define MOPT_CLEAR	0x0002
1820 #define MOPT_NOSUPPORT	0x0004
1821 #define MOPT_EXPLICIT	0x0008
1822 #ifdef CONFIG_QUOTA
1823 #define MOPT_Q		0
1824 #define MOPT_QFMT	0x0010
1825 #else
1826 #define MOPT_Q		MOPT_NOSUPPORT
1827 #define MOPT_QFMT	MOPT_NOSUPPORT
1828 #endif
1829 #define MOPT_NO_EXT2	0x0020
1830 #define MOPT_NO_EXT3	0x0040
1831 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1832 #define MOPT_SKIP	0x0080
1833 #define	MOPT_2		0x0100
1834 
1835 static const struct mount_opts {
1836 	int	token;
1837 	int	mount_opt;
1838 	int	flags;
1839 } ext4_mount_opts[] = {
1840 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1841 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1842 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1843 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1844 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1845 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1846 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1847 	 MOPT_EXT4_ONLY | MOPT_SET},
1848 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1849 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1850 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1851 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1852 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1853 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1854 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1855 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1856 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1857 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1858 	{Opt_commit, 0, MOPT_NO_EXT2},
1859 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1860 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1861 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1862 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1863 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1864 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1865 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1866 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1867 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1868 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1869 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1870 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1871 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1872 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1873 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1874 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1875 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1876 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1877 	{Opt_data, 0, MOPT_NO_EXT2},
1878 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1879 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1880 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1881 #else
1882 	{Opt_acl, 0, MOPT_NOSUPPORT},
1883 #endif
1884 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1885 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1886 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1887 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1888 							MOPT_SET | MOPT_Q},
1889 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1890 							MOPT_SET | MOPT_Q},
1891 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1892 							MOPT_SET | MOPT_Q},
1893 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1894 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1895 							MOPT_CLEAR | MOPT_Q},
1896 	{Opt_usrjquota, 0, MOPT_Q},
1897 	{Opt_grpjquota, 0, MOPT_Q},
1898 	{Opt_jqfmt, 0, MOPT_QFMT},
1899 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1900 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1901 	 MOPT_SET},
1902 #ifdef CONFIG_EXT4_DEBUG
1903 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1904 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1905 #endif
1906 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1907 	{Opt_err, 0, 0}
1908 };
1909 
1910 #if IS_ENABLED(CONFIG_UNICODE)
1911 static const struct ext4_sb_encodings {
1912 	__u16 magic;
1913 	char *name;
1914 	unsigned int version;
1915 } ext4_sb_encoding_map[] = {
1916 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1917 };
1918 
1919 static const struct ext4_sb_encodings *
1920 ext4_sb_read_encoding(const struct ext4_super_block *es)
1921 {
1922 	__u16 magic = le16_to_cpu(es->s_encoding);
1923 	int i;
1924 
1925 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1926 		if (magic == ext4_sb_encoding_map[i].magic)
1927 			return &ext4_sb_encoding_map[i];
1928 
1929 	return NULL;
1930 }
1931 #endif
1932 
1933 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1934 #define EXT4_SPEC_JQFMT				(1 <<  1)
1935 #define EXT4_SPEC_DATAJ				(1 <<  2)
1936 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1937 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1938 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1939 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1940 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1941 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1942 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1943 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1944 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1945 #define EXT4_SPEC_s_stripe			(1 << 13)
1946 #define EXT4_SPEC_s_resuid			(1 << 14)
1947 #define EXT4_SPEC_s_resgid			(1 << 15)
1948 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1949 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1950 #define EXT4_SPEC_s_sb_block			(1 << 18)
1951 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1952 
1953 struct ext4_fs_context {
1954 	char		*s_qf_names[EXT4_MAXQUOTAS];
1955 	struct fscrypt_dummy_policy dummy_enc_policy;
1956 	int		s_jquota_fmt;	/* Format of quota to use */
1957 #ifdef CONFIG_EXT4_DEBUG
1958 	int s_fc_debug_max_replay;
1959 #endif
1960 	unsigned short	qname_spec;
1961 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1962 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1963 	unsigned long	journal_devnum;
1964 	unsigned long	s_commit_interval;
1965 	unsigned long	s_stripe;
1966 	unsigned int	s_inode_readahead_blks;
1967 	unsigned int	s_want_extra_isize;
1968 	unsigned int	s_li_wait_mult;
1969 	unsigned int	s_max_dir_size_kb;
1970 	unsigned int	journal_ioprio;
1971 	unsigned int	vals_s_mount_opt;
1972 	unsigned int	mask_s_mount_opt;
1973 	unsigned int	vals_s_mount_opt2;
1974 	unsigned int	mask_s_mount_opt2;
1975 	unsigned int	opt_flags;	/* MOPT flags */
1976 	unsigned int	spec;
1977 	u32		s_max_batch_time;
1978 	u32		s_min_batch_time;
1979 	kuid_t		s_resuid;
1980 	kgid_t		s_resgid;
1981 	ext4_fsblk_t	s_sb_block;
1982 };
1983 
1984 static void ext4_fc_free(struct fs_context *fc)
1985 {
1986 	struct ext4_fs_context *ctx = fc->fs_private;
1987 	int i;
1988 
1989 	if (!ctx)
1990 		return;
1991 
1992 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1993 		kfree(ctx->s_qf_names[i]);
1994 
1995 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1996 	kfree(ctx);
1997 }
1998 
1999 int ext4_init_fs_context(struct fs_context *fc)
2000 {
2001 	struct ext4_fs_context *ctx;
2002 
2003 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2004 	if (!ctx)
2005 		return -ENOMEM;
2006 
2007 	fc->fs_private = ctx;
2008 	fc->ops = &ext4_context_ops;
2009 
2010 	return 0;
2011 }
2012 
2013 #ifdef CONFIG_QUOTA
2014 /*
2015  * Note the name of the specified quota file.
2016  */
2017 static int note_qf_name(struct fs_context *fc, int qtype,
2018 		       struct fs_parameter *param)
2019 {
2020 	struct ext4_fs_context *ctx = fc->fs_private;
2021 	char *qname;
2022 
2023 	if (param->size < 1) {
2024 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2025 		return -EINVAL;
2026 	}
2027 	if (strchr(param->string, '/')) {
2028 		ext4_msg(NULL, KERN_ERR,
2029 			 "quotafile must be on filesystem root");
2030 		return -EINVAL;
2031 	}
2032 	if (ctx->s_qf_names[qtype]) {
2033 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2034 			ext4_msg(NULL, KERN_ERR,
2035 				 "%s quota file already specified",
2036 				 QTYPE2NAME(qtype));
2037 			return -EINVAL;
2038 		}
2039 		return 0;
2040 	}
2041 
2042 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2043 	if (!qname) {
2044 		ext4_msg(NULL, KERN_ERR,
2045 			 "Not enough memory for storing quotafile name");
2046 		return -ENOMEM;
2047 	}
2048 	ctx->s_qf_names[qtype] = qname;
2049 	ctx->qname_spec |= 1 << qtype;
2050 	ctx->spec |= EXT4_SPEC_JQUOTA;
2051 	return 0;
2052 }
2053 
2054 /*
2055  * Clear the name of the specified quota file.
2056  */
2057 static int unnote_qf_name(struct fs_context *fc, int qtype)
2058 {
2059 	struct ext4_fs_context *ctx = fc->fs_private;
2060 
2061 	kfree(ctx->s_qf_names[qtype]);
2062 
2063 	ctx->s_qf_names[qtype] = NULL;
2064 	ctx->qname_spec |= 1 << qtype;
2065 	ctx->spec |= EXT4_SPEC_JQUOTA;
2066 	return 0;
2067 }
2068 #endif
2069 
2070 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2071 					    struct ext4_fs_context *ctx)
2072 {
2073 	int err;
2074 
2075 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2076 		ext4_msg(NULL, KERN_WARNING,
2077 			 "test_dummy_encryption option not supported");
2078 		return -EINVAL;
2079 	}
2080 	err = fscrypt_parse_test_dummy_encryption(param,
2081 						  &ctx->dummy_enc_policy);
2082 	if (err == -EINVAL) {
2083 		ext4_msg(NULL, KERN_WARNING,
2084 			 "Value of option \"%s\" is unrecognized", param->key);
2085 	} else if (err == -EEXIST) {
2086 		ext4_msg(NULL, KERN_WARNING,
2087 			 "Conflicting test_dummy_encryption options");
2088 		return -EINVAL;
2089 	}
2090 	return err;
2091 }
2092 
2093 #define EXT4_SET_CTX(name)						\
2094 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2095 				  unsigned long flag)			\
2096 {									\
2097 	ctx->mask_s_##name |= flag;					\
2098 	ctx->vals_s_##name |= flag;					\
2099 }
2100 
2101 #define EXT4_CLEAR_CTX(name)						\
2102 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2103 				    unsigned long flag)			\
2104 {									\
2105 	ctx->mask_s_##name |= flag;					\
2106 	ctx->vals_s_##name &= ~flag;					\
2107 }
2108 
2109 #define EXT4_TEST_CTX(name)						\
2110 static inline unsigned long						\
2111 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2112 {									\
2113 	return (ctx->vals_s_##name & flag);				\
2114 }
2115 
2116 EXT4_SET_CTX(flags); /* set only */
2117 EXT4_SET_CTX(mount_opt);
2118 EXT4_CLEAR_CTX(mount_opt);
2119 EXT4_TEST_CTX(mount_opt);
2120 EXT4_SET_CTX(mount_opt2);
2121 EXT4_CLEAR_CTX(mount_opt2);
2122 EXT4_TEST_CTX(mount_opt2);
2123 
2124 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2125 {
2126 	struct ext4_fs_context *ctx = fc->fs_private;
2127 	struct fs_parse_result result;
2128 	const struct mount_opts *m;
2129 	int is_remount;
2130 	kuid_t uid;
2131 	kgid_t gid;
2132 	int token;
2133 
2134 	token = fs_parse(fc, ext4_param_specs, param, &result);
2135 	if (token < 0)
2136 		return token;
2137 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2138 
2139 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2140 		if (token == m->token)
2141 			break;
2142 
2143 	ctx->opt_flags |= m->flags;
2144 
2145 	if (m->flags & MOPT_EXPLICIT) {
2146 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2147 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2148 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2149 			ctx_set_mount_opt2(ctx,
2150 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2151 		} else
2152 			return -EINVAL;
2153 	}
2154 
2155 	if (m->flags & MOPT_NOSUPPORT) {
2156 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2157 			 param->key);
2158 		return 0;
2159 	}
2160 
2161 	switch (token) {
2162 #ifdef CONFIG_QUOTA
2163 	case Opt_usrjquota:
2164 		if (!*param->string)
2165 			return unnote_qf_name(fc, USRQUOTA);
2166 		else
2167 			return note_qf_name(fc, USRQUOTA, param);
2168 	case Opt_grpjquota:
2169 		if (!*param->string)
2170 			return unnote_qf_name(fc, GRPQUOTA);
2171 		else
2172 			return note_qf_name(fc, GRPQUOTA, param);
2173 #endif
2174 	case Opt_sb:
2175 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2176 			ext4_msg(NULL, KERN_WARNING,
2177 				 "Ignoring %s option on remount", param->key);
2178 		} else {
2179 			ctx->s_sb_block = result.uint_32;
2180 			ctx->spec |= EXT4_SPEC_s_sb_block;
2181 		}
2182 		return 0;
2183 	case Opt_removed:
2184 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2185 			 param->key);
2186 		return 0;
2187 	case Opt_inlinecrypt:
2188 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2189 		ctx_set_flags(ctx, SB_INLINECRYPT);
2190 #else
2191 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2192 #endif
2193 		return 0;
2194 	case Opt_errors:
2195 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2196 		ctx_set_mount_opt(ctx, result.uint_32);
2197 		return 0;
2198 #ifdef CONFIG_QUOTA
2199 	case Opt_jqfmt:
2200 		ctx->s_jquota_fmt = result.uint_32;
2201 		ctx->spec |= EXT4_SPEC_JQFMT;
2202 		return 0;
2203 #endif
2204 	case Opt_data:
2205 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2206 		ctx_set_mount_opt(ctx, result.uint_32);
2207 		ctx->spec |= EXT4_SPEC_DATAJ;
2208 		return 0;
2209 	case Opt_commit:
2210 		if (result.uint_32 == 0)
2211 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2212 		else if (result.uint_32 > INT_MAX / HZ) {
2213 			ext4_msg(NULL, KERN_ERR,
2214 				 "Invalid commit interval %d, "
2215 				 "must be smaller than %d",
2216 				 result.uint_32, INT_MAX / HZ);
2217 			return -EINVAL;
2218 		}
2219 		ctx->s_commit_interval = HZ * result.uint_32;
2220 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2221 		return 0;
2222 	case Opt_debug_want_extra_isize:
2223 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2224 			ext4_msg(NULL, KERN_ERR,
2225 				 "Invalid want_extra_isize %d", result.uint_32);
2226 			return -EINVAL;
2227 		}
2228 		ctx->s_want_extra_isize = result.uint_32;
2229 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2230 		return 0;
2231 	case Opt_max_batch_time:
2232 		ctx->s_max_batch_time = result.uint_32;
2233 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2234 		return 0;
2235 	case Opt_min_batch_time:
2236 		ctx->s_min_batch_time = result.uint_32;
2237 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2238 		return 0;
2239 	case Opt_inode_readahead_blks:
2240 		if (result.uint_32 &&
2241 		    (result.uint_32 > (1 << 30) ||
2242 		     !is_power_of_2(result.uint_32))) {
2243 			ext4_msg(NULL, KERN_ERR,
2244 				 "EXT4-fs: inode_readahead_blks must be "
2245 				 "0 or a power of 2 smaller than 2^31");
2246 			return -EINVAL;
2247 		}
2248 		ctx->s_inode_readahead_blks = result.uint_32;
2249 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2250 		return 0;
2251 	case Opt_init_itable:
2252 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2253 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2254 		if (param->type == fs_value_is_string)
2255 			ctx->s_li_wait_mult = result.uint_32;
2256 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2257 		return 0;
2258 	case Opt_max_dir_size_kb:
2259 		ctx->s_max_dir_size_kb = result.uint_32;
2260 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2261 		return 0;
2262 #ifdef CONFIG_EXT4_DEBUG
2263 	case Opt_fc_debug_max_replay:
2264 		ctx->s_fc_debug_max_replay = result.uint_32;
2265 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2266 		return 0;
2267 #endif
2268 	case Opt_stripe:
2269 		ctx->s_stripe = result.uint_32;
2270 		ctx->spec |= EXT4_SPEC_s_stripe;
2271 		return 0;
2272 	case Opt_resuid:
2273 		uid = make_kuid(current_user_ns(), result.uint_32);
2274 		if (!uid_valid(uid)) {
2275 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2276 				 result.uint_32);
2277 			return -EINVAL;
2278 		}
2279 		ctx->s_resuid = uid;
2280 		ctx->spec |= EXT4_SPEC_s_resuid;
2281 		return 0;
2282 	case Opt_resgid:
2283 		gid = make_kgid(current_user_ns(), result.uint_32);
2284 		if (!gid_valid(gid)) {
2285 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2286 				 result.uint_32);
2287 			return -EINVAL;
2288 		}
2289 		ctx->s_resgid = gid;
2290 		ctx->spec |= EXT4_SPEC_s_resgid;
2291 		return 0;
2292 	case Opt_journal_dev:
2293 		if (is_remount) {
2294 			ext4_msg(NULL, KERN_ERR,
2295 				 "Cannot specify journal on remount");
2296 			return -EINVAL;
2297 		}
2298 		ctx->journal_devnum = result.uint_32;
2299 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2300 		return 0;
2301 	case Opt_journal_path:
2302 	{
2303 		struct inode *journal_inode;
2304 		struct path path;
2305 		int error;
2306 
2307 		if (is_remount) {
2308 			ext4_msg(NULL, KERN_ERR,
2309 				 "Cannot specify journal on remount");
2310 			return -EINVAL;
2311 		}
2312 
2313 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2314 		if (error) {
2315 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2316 				 "journal device path");
2317 			return -EINVAL;
2318 		}
2319 
2320 		journal_inode = d_inode(path.dentry);
2321 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2322 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2323 		path_put(&path);
2324 		return 0;
2325 	}
2326 	case Opt_journal_ioprio:
2327 		if (result.uint_32 > 7) {
2328 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2329 				 " (must be 0-7)");
2330 			return -EINVAL;
2331 		}
2332 		ctx->journal_ioprio =
2333 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2334 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2335 		return 0;
2336 	case Opt_test_dummy_encryption:
2337 		return ext4_parse_test_dummy_encryption(param, ctx);
2338 	case Opt_dax:
2339 	case Opt_dax_type:
2340 #ifdef CONFIG_FS_DAX
2341 	{
2342 		int type = (token == Opt_dax) ?
2343 			   Opt_dax : result.uint_32;
2344 
2345 		switch (type) {
2346 		case Opt_dax:
2347 		case Opt_dax_always:
2348 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2349 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2350 			break;
2351 		case Opt_dax_never:
2352 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2353 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2354 			break;
2355 		case Opt_dax_inode:
2356 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2357 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2358 			/* Strictly for printing options */
2359 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2360 			break;
2361 		}
2362 		return 0;
2363 	}
2364 #else
2365 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2366 		return -EINVAL;
2367 #endif
2368 	case Opt_data_err:
2369 		if (result.uint_32 == Opt_data_err_abort)
2370 			ctx_set_mount_opt(ctx, m->mount_opt);
2371 		else if (result.uint_32 == Opt_data_err_ignore)
2372 			ctx_clear_mount_opt(ctx, m->mount_opt);
2373 		return 0;
2374 	case Opt_mb_optimize_scan:
2375 		if (result.int_32 == 1) {
2376 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2377 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2378 		} else if (result.int_32 == 0) {
2379 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2380 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2381 		} else {
2382 			ext4_msg(NULL, KERN_WARNING,
2383 				 "mb_optimize_scan should be set to 0 or 1.");
2384 			return -EINVAL;
2385 		}
2386 		return 0;
2387 	}
2388 
2389 	/*
2390 	 * At this point we should only be getting options requiring MOPT_SET,
2391 	 * or MOPT_CLEAR. Anything else is a bug
2392 	 */
2393 	if (m->token == Opt_err) {
2394 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2395 			 param->key);
2396 		WARN_ON(1);
2397 		return -EINVAL;
2398 	}
2399 
2400 	else {
2401 		unsigned int set = 0;
2402 
2403 		if ((param->type == fs_value_is_flag) ||
2404 		    result.uint_32 > 0)
2405 			set = 1;
2406 
2407 		if (m->flags & MOPT_CLEAR)
2408 			set = !set;
2409 		else if (unlikely(!(m->flags & MOPT_SET))) {
2410 			ext4_msg(NULL, KERN_WARNING,
2411 				 "buggy handling of option %s",
2412 				 param->key);
2413 			WARN_ON(1);
2414 			return -EINVAL;
2415 		}
2416 		if (m->flags & MOPT_2) {
2417 			if (set != 0)
2418 				ctx_set_mount_opt2(ctx, m->mount_opt);
2419 			else
2420 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2421 		} else {
2422 			if (set != 0)
2423 				ctx_set_mount_opt(ctx, m->mount_opt);
2424 			else
2425 				ctx_clear_mount_opt(ctx, m->mount_opt);
2426 		}
2427 	}
2428 
2429 	return 0;
2430 }
2431 
2432 static int parse_options(struct fs_context *fc, char *options)
2433 {
2434 	struct fs_parameter param;
2435 	int ret;
2436 	char *key;
2437 
2438 	if (!options)
2439 		return 0;
2440 
2441 	while ((key = strsep(&options, ",")) != NULL) {
2442 		if (*key) {
2443 			size_t v_len = 0;
2444 			char *value = strchr(key, '=');
2445 
2446 			param.type = fs_value_is_flag;
2447 			param.string = NULL;
2448 
2449 			if (value) {
2450 				if (value == key)
2451 					continue;
2452 
2453 				*value++ = 0;
2454 				v_len = strlen(value);
2455 				param.string = kmemdup_nul(value, v_len,
2456 							   GFP_KERNEL);
2457 				if (!param.string)
2458 					return -ENOMEM;
2459 				param.type = fs_value_is_string;
2460 			}
2461 
2462 			param.key = key;
2463 			param.size = v_len;
2464 
2465 			ret = ext4_parse_param(fc, &param);
2466 			kfree(param.string);
2467 			if (ret < 0)
2468 				return ret;
2469 		}
2470 	}
2471 
2472 	ret = ext4_validate_options(fc);
2473 	if (ret < 0)
2474 		return ret;
2475 
2476 	return 0;
2477 }
2478 
2479 static int parse_apply_sb_mount_options(struct super_block *sb,
2480 					struct ext4_fs_context *m_ctx)
2481 {
2482 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2483 	char *s_mount_opts = NULL;
2484 	struct ext4_fs_context *s_ctx = NULL;
2485 	struct fs_context *fc = NULL;
2486 	int ret = -ENOMEM;
2487 
2488 	if (!sbi->s_es->s_mount_opts[0])
2489 		return 0;
2490 
2491 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2492 				sizeof(sbi->s_es->s_mount_opts),
2493 				GFP_KERNEL);
2494 	if (!s_mount_opts)
2495 		return ret;
2496 
2497 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2498 	if (!fc)
2499 		goto out_free;
2500 
2501 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2502 	if (!s_ctx)
2503 		goto out_free;
2504 
2505 	fc->fs_private = s_ctx;
2506 	fc->s_fs_info = sbi;
2507 
2508 	ret = parse_options(fc, s_mount_opts);
2509 	if (ret < 0)
2510 		goto parse_failed;
2511 
2512 	ret = ext4_check_opt_consistency(fc, sb);
2513 	if (ret < 0) {
2514 parse_failed:
2515 		ext4_msg(sb, KERN_WARNING,
2516 			 "failed to parse options in superblock: %s",
2517 			 s_mount_opts);
2518 		ret = 0;
2519 		goto out_free;
2520 	}
2521 
2522 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2523 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2524 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2525 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2526 
2527 	ext4_apply_options(fc, sb);
2528 	ret = 0;
2529 
2530 out_free:
2531 	if (fc) {
2532 		ext4_fc_free(fc);
2533 		kfree(fc);
2534 	}
2535 	kfree(s_mount_opts);
2536 	return ret;
2537 }
2538 
2539 static void ext4_apply_quota_options(struct fs_context *fc,
2540 				     struct super_block *sb)
2541 {
2542 #ifdef CONFIG_QUOTA
2543 	bool quota_feature = ext4_has_feature_quota(sb);
2544 	struct ext4_fs_context *ctx = fc->fs_private;
2545 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2546 	char *qname;
2547 	int i;
2548 
2549 	if (quota_feature)
2550 		return;
2551 
2552 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2553 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2554 			if (!(ctx->qname_spec & (1 << i)))
2555 				continue;
2556 
2557 			qname = ctx->s_qf_names[i]; /* May be NULL */
2558 			if (qname)
2559 				set_opt(sb, QUOTA);
2560 			ctx->s_qf_names[i] = NULL;
2561 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2562 						lockdep_is_held(&sb->s_umount));
2563 			if (qname)
2564 				kfree_rcu_mightsleep(qname);
2565 		}
2566 	}
2567 
2568 	if (ctx->spec & EXT4_SPEC_JQFMT)
2569 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2570 #endif
2571 }
2572 
2573 /*
2574  * Check quota settings consistency.
2575  */
2576 static int ext4_check_quota_consistency(struct fs_context *fc,
2577 					struct super_block *sb)
2578 {
2579 #ifdef CONFIG_QUOTA
2580 	struct ext4_fs_context *ctx = fc->fs_private;
2581 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2582 	bool quota_feature = ext4_has_feature_quota(sb);
2583 	bool quota_loaded = sb_any_quota_loaded(sb);
2584 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2585 	int quota_flags, i;
2586 
2587 	/*
2588 	 * We do the test below only for project quotas. 'usrquota' and
2589 	 * 'grpquota' mount options are allowed even without quota feature
2590 	 * to support legacy quotas in quota files.
2591 	 */
2592 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2593 	    !ext4_has_feature_project(sb)) {
2594 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2595 			 "Cannot enable project quota enforcement.");
2596 		return -EINVAL;
2597 	}
2598 
2599 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2600 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2601 	if (quota_loaded &&
2602 	    ctx->mask_s_mount_opt & quota_flags &&
2603 	    !ctx_test_mount_opt(ctx, quota_flags))
2604 		goto err_quota_change;
2605 
2606 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2607 
2608 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2609 			if (!(ctx->qname_spec & (1 << i)))
2610 				continue;
2611 
2612 			if (quota_loaded &&
2613 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2614 				goto err_jquota_change;
2615 
2616 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2617 			    strcmp(get_qf_name(sb, sbi, i),
2618 				   ctx->s_qf_names[i]) != 0)
2619 				goto err_jquota_specified;
2620 		}
2621 
2622 		if (quota_feature) {
2623 			ext4_msg(NULL, KERN_INFO,
2624 				 "Journaled quota options ignored when "
2625 				 "QUOTA feature is enabled");
2626 			return 0;
2627 		}
2628 	}
2629 
2630 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2631 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2632 			goto err_jquota_change;
2633 		if (quota_feature) {
2634 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2635 				 "ignored when QUOTA feature is enabled");
2636 			return 0;
2637 		}
2638 	}
2639 
2640 	/* Make sure we don't mix old and new quota format */
2641 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2642 		       ctx->s_qf_names[USRQUOTA]);
2643 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2644 		       ctx->s_qf_names[GRPQUOTA]);
2645 
2646 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2647 		    test_opt(sb, USRQUOTA));
2648 
2649 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2650 		    test_opt(sb, GRPQUOTA));
2651 
2652 	if (usr_qf_name) {
2653 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2654 		usrquota = false;
2655 	}
2656 	if (grp_qf_name) {
2657 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2658 		grpquota = false;
2659 	}
2660 
2661 	if (usr_qf_name || grp_qf_name) {
2662 		if (usrquota || grpquota) {
2663 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2664 				 "format mixing");
2665 			return -EINVAL;
2666 		}
2667 
2668 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2669 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2670 				 "not specified");
2671 			return -EINVAL;
2672 		}
2673 	}
2674 
2675 	return 0;
2676 
2677 err_quota_change:
2678 	ext4_msg(NULL, KERN_ERR,
2679 		 "Cannot change quota options when quota turned on");
2680 	return -EINVAL;
2681 err_jquota_change:
2682 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2683 		 "options when quota turned on");
2684 	return -EINVAL;
2685 err_jquota_specified:
2686 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2687 		 QTYPE2NAME(i));
2688 	return -EINVAL;
2689 #else
2690 	return 0;
2691 #endif
2692 }
2693 
2694 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2695 					    struct super_block *sb)
2696 {
2697 	const struct ext4_fs_context *ctx = fc->fs_private;
2698 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2699 
2700 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2701 		return 0;
2702 
2703 	if (!ext4_has_feature_encrypt(sb)) {
2704 		ext4_msg(NULL, KERN_WARNING,
2705 			 "test_dummy_encryption requires encrypt feature");
2706 		return -EINVAL;
2707 	}
2708 	/*
2709 	 * This mount option is just for testing, and it's not worthwhile to
2710 	 * implement the extra complexity (e.g. RCU protection) that would be
2711 	 * needed to allow it to be set or changed during remount.  We do allow
2712 	 * it to be specified during remount, but only if there is no change.
2713 	 */
2714 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
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 			 "Can't set or change test_dummy_encryption on remount");
2720 		return -EINVAL;
2721 	}
2722 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2723 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2724 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2725 						 &ctx->dummy_enc_policy))
2726 			return 0;
2727 		ext4_msg(NULL, KERN_WARNING,
2728 			 "Conflicting test_dummy_encryption options");
2729 		return -EINVAL;
2730 	}
2731 	return 0;
2732 }
2733 
2734 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2735 					     struct super_block *sb)
2736 {
2737 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2738 	    /* if already set, it was already verified to be the same */
2739 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2740 		return;
2741 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2742 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2743 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2744 }
2745 
2746 static int ext4_check_opt_consistency(struct fs_context *fc,
2747 				      struct super_block *sb)
2748 {
2749 	struct ext4_fs_context *ctx = fc->fs_private;
2750 	struct ext4_sb_info *sbi = fc->s_fs_info;
2751 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2752 	int err;
2753 
2754 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2755 		ext4_msg(NULL, KERN_ERR,
2756 			 "Mount option(s) incompatible with ext2");
2757 		return -EINVAL;
2758 	}
2759 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2760 		ext4_msg(NULL, KERN_ERR,
2761 			 "Mount option(s) incompatible with ext3");
2762 		return -EINVAL;
2763 	}
2764 
2765 	if (ctx->s_want_extra_isize >
2766 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2767 		ext4_msg(NULL, KERN_ERR,
2768 			 "Invalid want_extra_isize %d",
2769 			 ctx->s_want_extra_isize);
2770 		return -EINVAL;
2771 	}
2772 
2773 	err = ext4_check_test_dummy_encryption(fc, sb);
2774 	if (err)
2775 		return err;
2776 
2777 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2778 		if (!sbi->s_journal) {
2779 			ext4_msg(NULL, KERN_WARNING,
2780 				 "Remounting file system with no journal "
2781 				 "so ignoring journalled data option");
2782 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2783 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2784 			   test_opt(sb, DATA_FLAGS)) {
2785 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2786 				 "on remount");
2787 			return -EINVAL;
2788 		}
2789 	}
2790 
2791 	if (is_remount) {
2792 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2793 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2794 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2795 				 "both data=journal and dax");
2796 			return -EINVAL;
2797 		}
2798 
2799 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2800 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2801 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2802 fail_dax_change_remount:
2803 			ext4_msg(NULL, KERN_ERR, "can't change "
2804 				 "dax mount option while remounting");
2805 			return -EINVAL;
2806 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2807 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2808 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2809 			goto fail_dax_change_remount;
2810 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2811 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2812 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2813 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2814 			goto fail_dax_change_remount;
2815 		}
2816 	}
2817 
2818 	return ext4_check_quota_consistency(fc, sb);
2819 }
2820 
2821 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2822 {
2823 	struct ext4_fs_context *ctx = fc->fs_private;
2824 	struct ext4_sb_info *sbi = fc->s_fs_info;
2825 
2826 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2827 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2828 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2829 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2830 	sb->s_flags &= ~ctx->mask_s_flags;
2831 	sb->s_flags |= ctx->vals_s_flags;
2832 
2833 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2834 	APPLY(s_commit_interval);
2835 	APPLY(s_stripe);
2836 	APPLY(s_max_batch_time);
2837 	APPLY(s_min_batch_time);
2838 	APPLY(s_want_extra_isize);
2839 	APPLY(s_inode_readahead_blks);
2840 	APPLY(s_max_dir_size_kb);
2841 	APPLY(s_li_wait_mult);
2842 	APPLY(s_resgid);
2843 	APPLY(s_resuid);
2844 
2845 #ifdef CONFIG_EXT4_DEBUG
2846 	APPLY(s_fc_debug_max_replay);
2847 #endif
2848 
2849 	ext4_apply_quota_options(fc, sb);
2850 	ext4_apply_test_dummy_encryption(ctx, sb);
2851 }
2852 
2853 
2854 static int ext4_validate_options(struct fs_context *fc)
2855 {
2856 #ifdef CONFIG_QUOTA
2857 	struct ext4_fs_context *ctx = fc->fs_private;
2858 	char *usr_qf_name, *grp_qf_name;
2859 
2860 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2861 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2862 
2863 	if (usr_qf_name || grp_qf_name) {
2864 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2865 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2866 
2867 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2868 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2869 
2870 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2871 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2872 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2873 				 "format mixing");
2874 			return -EINVAL;
2875 		}
2876 	}
2877 #endif
2878 	return 1;
2879 }
2880 
2881 static inline void ext4_show_quota_options(struct seq_file *seq,
2882 					   struct super_block *sb)
2883 {
2884 #if defined(CONFIG_QUOTA)
2885 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2886 	char *usr_qf_name, *grp_qf_name;
2887 
2888 	if (sbi->s_jquota_fmt) {
2889 		char *fmtname = "";
2890 
2891 		switch (sbi->s_jquota_fmt) {
2892 		case QFMT_VFS_OLD:
2893 			fmtname = "vfsold";
2894 			break;
2895 		case QFMT_VFS_V0:
2896 			fmtname = "vfsv0";
2897 			break;
2898 		case QFMT_VFS_V1:
2899 			fmtname = "vfsv1";
2900 			break;
2901 		}
2902 		seq_printf(seq, ",jqfmt=%s", fmtname);
2903 	}
2904 
2905 	rcu_read_lock();
2906 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2907 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2908 	if (usr_qf_name)
2909 		seq_show_option(seq, "usrjquota", usr_qf_name);
2910 	if (grp_qf_name)
2911 		seq_show_option(seq, "grpjquota", grp_qf_name);
2912 	rcu_read_unlock();
2913 #endif
2914 }
2915 
2916 static const char *token2str(int token)
2917 {
2918 	const struct fs_parameter_spec *spec;
2919 
2920 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2921 		if (spec->opt == token && !spec->type)
2922 			break;
2923 	return spec->name;
2924 }
2925 
2926 /*
2927  * Show an option if
2928  *  - it's set to a non-default value OR
2929  *  - if the per-sb default is different from the global default
2930  */
2931 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2932 			      int nodefs)
2933 {
2934 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2935 	struct ext4_super_block *es = sbi->s_es;
2936 	int def_errors;
2937 	const struct mount_opts *m;
2938 	char sep = nodefs ? '\n' : ',';
2939 
2940 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2941 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2942 
2943 	if (sbi->s_sb_block != 1)
2944 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2945 
2946 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2947 		int want_set = m->flags & MOPT_SET;
2948 		int opt_2 = m->flags & MOPT_2;
2949 		unsigned int mount_opt, def_mount_opt;
2950 
2951 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2952 		    m->flags & MOPT_SKIP)
2953 			continue;
2954 
2955 		if (opt_2) {
2956 			mount_opt = sbi->s_mount_opt2;
2957 			def_mount_opt = sbi->s_def_mount_opt2;
2958 		} else {
2959 			mount_opt = sbi->s_mount_opt;
2960 			def_mount_opt = sbi->s_def_mount_opt;
2961 		}
2962 		/* skip if same as the default */
2963 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2964 			continue;
2965 		/* select Opt_noFoo vs Opt_Foo */
2966 		if ((want_set &&
2967 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2968 		    (!want_set && (mount_opt & m->mount_opt)))
2969 			continue;
2970 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2971 	}
2972 
2973 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2974 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2975 		SEQ_OPTS_PRINT("resuid=%u",
2976 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2977 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2978 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2979 		SEQ_OPTS_PRINT("resgid=%u",
2980 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2981 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2982 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2983 		SEQ_OPTS_PUTS("errors=remount-ro");
2984 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2985 		SEQ_OPTS_PUTS("errors=continue");
2986 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2987 		SEQ_OPTS_PUTS("errors=panic");
2988 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2989 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2990 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2991 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2992 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2993 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2994 	if (nodefs || sbi->s_stripe)
2995 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2996 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2997 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
2998 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2999 			SEQ_OPTS_PUTS("data=journal");
3000 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3001 			SEQ_OPTS_PUTS("data=ordered");
3002 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3003 			SEQ_OPTS_PUTS("data=writeback");
3004 	}
3005 	if (nodefs ||
3006 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3007 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3008 			       sbi->s_inode_readahead_blks);
3009 
3010 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3011 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3012 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3013 	if (nodefs || sbi->s_max_dir_size_kb)
3014 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3015 	if (test_opt(sb, DATA_ERR_ABORT))
3016 		SEQ_OPTS_PUTS("data_err=abort");
3017 
3018 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3019 
3020 	if (sb->s_flags & SB_INLINECRYPT)
3021 		SEQ_OPTS_PUTS("inlinecrypt");
3022 
3023 	if (test_opt(sb, DAX_ALWAYS)) {
3024 		if (IS_EXT2_SB(sb))
3025 			SEQ_OPTS_PUTS("dax");
3026 		else
3027 			SEQ_OPTS_PUTS("dax=always");
3028 	} else if (test_opt2(sb, DAX_NEVER)) {
3029 		SEQ_OPTS_PUTS("dax=never");
3030 	} else if (test_opt2(sb, DAX_INODE)) {
3031 		SEQ_OPTS_PUTS("dax=inode");
3032 	}
3033 
3034 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3035 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3036 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3037 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3038 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3039 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3040 	}
3041 
3042 	ext4_show_quota_options(seq, sb);
3043 	return 0;
3044 }
3045 
3046 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3047 {
3048 	return _ext4_show_options(seq, root->d_sb, 0);
3049 }
3050 
3051 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3052 {
3053 	struct super_block *sb = seq->private;
3054 	int rc;
3055 
3056 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3057 	rc = _ext4_show_options(seq, sb, 1);
3058 	seq_puts(seq, "\n");
3059 	return rc;
3060 }
3061 
3062 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3063 			    int read_only)
3064 {
3065 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3066 	int err = 0;
3067 
3068 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3069 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3070 			 "forcing read-only mode");
3071 		err = -EROFS;
3072 		goto done;
3073 	}
3074 	if (read_only)
3075 		goto done;
3076 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3077 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3078 			 "running e2fsck is recommended");
3079 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3080 		ext4_msg(sb, KERN_WARNING,
3081 			 "warning: mounting fs with errors, "
3082 			 "running e2fsck is recommended");
3083 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3084 		 le16_to_cpu(es->s_mnt_count) >=
3085 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3086 		ext4_msg(sb, KERN_WARNING,
3087 			 "warning: maximal mount count reached, "
3088 			 "running e2fsck is recommended");
3089 	else if (le32_to_cpu(es->s_checkinterval) &&
3090 		 (ext4_get_tstamp(es, s_lastcheck) +
3091 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3092 		ext4_msg(sb, KERN_WARNING,
3093 			 "warning: checktime reached, "
3094 			 "running e2fsck is recommended");
3095 	if (!sbi->s_journal)
3096 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3097 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3098 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3099 	le16_add_cpu(&es->s_mnt_count, 1);
3100 	ext4_update_tstamp(es, s_mtime);
3101 	if (sbi->s_journal) {
3102 		ext4_set_feature_journal_needs_recovery(sb);
3103 		if (ext4_has_feature_orphan_file(sb))
3104 			ext4_set_feature_orphan_present(sb);
3105 	}
3106 
3107 	err = ext4_commit_super(sb);
3108 done:
3109 	if (test_opt(sb, DEBUG))
3110 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3111 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3112 			sb->s_blocksize,
3113 			sbi->s_groups_count,
3114 			EXT4_BLOCKS_PER_GROUP(sb),
3115 			EXT4_INODES_PER_GROUP(sb),
3116 			sbi->s_mount_opt, sbi->s_mount_opt2);
3117 	return err;
3118 }
3119 
3120 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3121 {
3122 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3123 	struct flex_groups **old_groups, **new_groups;
3124 	int size, i, j;
3125 
3126 	if (!sbi->s_log_groups_per_flex)
3127 		return 0;
3128 
3129 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3130 	if (size <= sbi->s_flex_groups_allocated)
3131 		return 0;
3132 
3133 	new_groups = kvzalloc(roundup_pow_of_two(size *
3134 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3135 	if (!new_groups) {
3136 		ext4_msg(sb, KERN_ERR,
3137 			 "not enough memory for %d flex group pointers", size);
3138 		return -ENOMEM;
3139 	}
3140 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3141 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3142 					 sizeof(struct flex_groups)),
3143 					 GFP_KERNEL);
3144 		if (!new_groups[i]) {
3145 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3146 				kvfree(new_groups[j]);
3147 			kvfree(new_groups);
3148 			ext4_msg(sb, KERN_ERR,
3149 				 "not enough memory for %d flex groups", size);
3150 			return -ENOMEM;
3151 		}
3152 	}
3153 	rcu_read_lock();
3154 	old_groups = rcu_dereference(sbi->s_flex_groups);
3155 	if (old_groups)
3156 		memcpy(new_groups, old_groups,
3157 		       (sbi->s_flex_groups_allocated *
3158 			sizeof(struct flex_groups *)));
3159 	rcu_read_unlock();
3160 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3161 	sbi->s_flex_groups_allocated = size;
3162 	if (old_groups)
3163 		ext4_kvfree_array_rcu(old_groups);
3164 	return 0;
3165 }
3166 
3167 static int ext4_fill_flex_info(struct super_block *sb)
3168 {
3169 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3170 	struct ext4_group_desc *gdp = NULL;
3171 	struct flex_groups *fg;
3172 	ext4_group_t flex_group;
3173 	int i, err;
3174 
3175 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3176 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3177 		sbi->s_log_groups_per_flex = 0;
3178 		return 1;
3179 	}
3180 
3181 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3182 	if (err)
3183 		goto failed;
3184 
3185 	for (i = 0; i < sbi->s_groups_count; i++) {
3186 		gdp = ext4_get_group_desc(sb, i, NULL);
3187 
3188 		flex_group = ext4_flex_group(sbi, i);
3189 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3190 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3191 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3192 			     &fg->free_clusters);
3193 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3194 	}
3195 
3196 	return 1;
3197 failed:
3198 	return 0;
3199 }
3200 
3201 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3202 				   struct ext4_group_desc *gdp)
3203 {
3204 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3205 	__u16 crc = 0;
3206 	__le32 le_group = cpu_to_le32(block_group);
3207 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3208 
3209 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3210 		/* Use new metadata_csum algorithm */
3211 		__u32 csum32;
3212 		__u16 dummy_csum = 0;
3213 
3214 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3215 				     sizeof(le_group));
3216 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3217 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3218 				     sizeof(dummy_csum));
3219 		offset += sizeof(dummy_csum);
3220 		if (offset < sbi->s_desc_size)
3221 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3222 					     sbi->s_desc_size - offset);
3223 
3224 		crc = csum32 & 0xFFFF;
3225 		goto out;
3226 	}
3227 
3228 	/* old crc16 code */
3229 	if (!ext4_has_feature_gdt_csum(sb))
3230 		return 0;
3231 
3232 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3233 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3234 	crc = crc16(crc, (__u8 *)gdp, offset);
3235 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3236 	/* for checksum of struct ext4_group_desc do the rest...*/
3237 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3238 		crc = crc16(crc, (__u8 *)gdp + offset,
3239 			    sbi->s_desc_size - offset);
3240 
3241 out:
3242 	return cpu_to_le16(crc);
3243 }
3244 
3245 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3246 				struct ext4_group_desc *gdp)
3247 {
3248 	if (ext4_has_group_desc_csum(sb) &&
3249 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3250 		return 0;
3251 
3252 	return 1;
3253 }
3254 
3255 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3256 			      struct ext4_group_desc *gdp)
3257 {
3258 	if (!ext4_has_group_desc_csum(sb))
3259 		return;
3260 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3261 }
3262 
3263 /* Called at mount-time, super-block is locked */
3264 static int ext4_check_descriptors(struct super_block *sb,
3265 				  ext4_fsblk_t sb_block,
3266 				  ext4_group_t *first_not_zeroed)
3267 {
3268 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3269 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3270 	ext4_fsblk_t last_block;
3271 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3272 	ext4_fsblk_t block_bitmap;
3273 	ext4_fsblk_t inode_bitmap;
3274 	ext4_fsblk_t inode_table;
3275 	int flexbg_flag = 0;
3276 	ext4_group_t i, grp = sbi->s_groups_count;
3277 
3278 	if (ext4_has_feature_flex_bg(sb))
3279 		flexbg_flag = 1;
3280 
3281 	ext4_debug("Checking group descriptors");
3282 
3283 	for (i = 0; i < sbi->s_groups_count; i++) {
3284 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3285 
3286 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3287 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3288 		else
3289 			last_block = first_block +
3290 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3291 
3292 		if ((grp == sbi->s_groups_count) &&
3293 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3294 			grp = i;
3295 
3296 		block_bitmap = ext4_block_bitmap(sb, gdp);
3297 		if (block_bitmap == sb_block) {
3298 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3299 				 "Block bitmap for group %u overlaps "
3300 				 "superblock", i);
3301 			if (!sb_rdonly(sb))
3302 				return 0;
3303 		}
3304 		if (block_bitmap >= sb_block + 1 &&
3305 		    block_bitmap <= last_bg_block) {
3306 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3307 				 "Block bitmap for group %u overlaps "
3308 				 "block group descriptors", i);
3309 			if (!sb_rdonly(sb))
3310 				return 0;
3311 		}
3312 		if (block_bitmap < first_block || block_bitmap > last_block) {
3313 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3314 			       "Block bitmap for group %u not in group "
3315 			       "(block %llu)!", i, block_bitmap);
3316 			return 0;
3317 		}
3318 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3319 		if (inode_bitmap == sb_block) {
3320 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3321 				 "Inode bitmap for group %u overlaps "
3322 				 "superblock", i);
3323 			if (!sb_rdonly(sb))
3324 				return 0;
3325 		}
3326 		if (inode_bitmap >= sb_block + 1 &&
3327 		    inode_bitmap <= last_bg_block) {
3328 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3329 				 "Inode bitmap for group %u overlaps "
3330 				 "block group descriptors", i);
3331 			if (!sb_rdonly(sb))
3332 				return 0;
3333 		}
3334 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3335 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3336 			       "Inode bitmap for group %u not in group "
3337 			       "(block %llu)!", i, inode_bitmap);
3338 			return 0;
3339 		}
3340 		inode_table = ext4_inode_table(sb, gdp);
3341 		if (inode_table == sb_block) {
3342 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3343 				 "Inode table for group %u overlaps "
3344 				 "superblock", i);
3345 			if (!sb_rdonly(sb))
3346 				return 0;
3347 		}
3348 		if (inode_table >= sb_block + 1 &&
3349 		    inode_table <= last_bg_block) {
3350 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3351 				 "Inode table for group %u overlaps "
3352 				 "block group descriptors", i);
3353 			if (!sb_rdonly(sb))
3354 				return 0;
3355 		}
3356 		if (inode_table < first_block ||
3357 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3358 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3359 			       "Inode table for group %u not in group "
3360 			       "(block %llu)!", i, inode_table);
3361 			return 0;
3362 		}
3363 		ext4_lock_group(sb, i);
3364 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3365 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3366 				 "Checksum for group %u failed (%u!=%u)",
3367 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3368 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3369 			if (!sb_rdonly(sb)) {
3370 				ext4_unlock_group(sb, i);
3371 				return 0;
3372 			}
3373 		}
3374 		ext4_unlock_group(sb, i);
3375 		if (!flexbg_flag)
3376 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3377 	}
3378 	if (NULL != first_not_zeroed)
3379 		*first_not_zeroed = grp;
3380 	return 1;
3381 }
3382 
3383 /*
3384  * Maximal extent format file size.
3385  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3386  * extent format containers, within a sector_t, and within i_blocks
3387  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3388  * so that won't be a limiting factor.
3389  *
3390  * However there is other limiting factor. We do store extents in the form
3391  * of starting block and length, hence the resulting length of the extent
3392  * covering maximum file size must fit into on-disk format containers as
3393  * well. Given that length is always by 1 unit bigger than max unit (because
3394  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3395  *
3396  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3397  */
3398 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3399 {
3400 	loff_t res;
3401 	loff_t upper_limit = MAX_LFS_FILESIZE;
3402 
3403 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3404 
3405 	if (!has_huge_files) {
3406 		upper_limit = (1LL << 32) - 1;
3407 
3408 		/* total blocks in file system block size */
3409 		upper_limit >>= (blkbits - 9);
3410 		upper_limit <<= blkbits;
3411 	}
3412 
3413 	/*
3414 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3415 	 * by one fs block, so ee_len can cover the extent of maximum file
3416 	 * size
3417 	 */
3418 	res = (1LL << 32) - 1;
3419 	res <<= blkbits;
3420 
3421 	/* Sanity check against vm- & vfs- imposed limits */
3422 	if (res > upper_limit)
3423 		res = upper_limit;
3424 
3425 	return res;
3426 }
3427 
3428 /*
3429  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3430  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3431  * We need to be 1 filesystem block less than the 2^48 sector limit.
3432  */
3433 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3434 {
3435 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3436 	int meta_blocks;
3437 	unsigned int ppb = 1 << (bits - 2);
3438 
3439 	/*
3440 	 * This is calculated to be the largest file size for a dense, block
3441 	 * mapped file such that the file's total number of 512-byte sectors,
3442 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3443 	 *
3444 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3445 	 * number of 512-byte sectors of the file.
3446 	 */
3447 	if (!has_huge_files) {
3448 		/*
3449 		 * !has_huge_files or implies that the inode i_block field
3450 		 * represents total file blocks in 2^32 512-byte sectors ==
3451 		 * size of vfs inode i_blocks * 8
3452 		 */
3453 		upper_limit = (1LL << 32) - 1;
3454 
3455 		/* total blocks in file system block size */
3456 		upper_limit >>= (bits - 9);
3457 
3458 	} else {
3459 		/*
3460 		 * We use 48 bit ext4_inode i_blocks
3461 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3462 		 * represent total number of blocks in
3463 		 * file system block size
3464 		 */
3465 		upper_limit = (1LL << 48) - 1;
3466 
3467 	}
3468 
3469 	/* Compute how many blocks we can address by block tree */
3470 	res += ppb;
3471 	res += ppb * ppb;
3472 	res += ((loff_t)ppb) * ppb * ppb;
3473 	/* Compute how many metadata blocks are needed */
3474 	meta_blocks = 1;
3475 	meta_blocks += 1 + ppb;
3476 	meta_blocks += 1 + ppb + ppb * ppb;
3477 	/* Does block tree limit file size? */
3478 	if (res + meta_blocks <= upper_limit)
3479 		goto check_lfs;
3480 
3481 	res = upper_limit;
3482 	/* How many metadata blocks are needed for addressing upper_limit? */
3483 	upper_limit -= EXT4_NDIR_BLOCKS;
3484 	/* indirect blocks */
3485 	meta_blocks = 1;
3486 	upper_limit -= ppb;
3487 	/* double indirect blocks */
3488 	if (upper_limit < ppb * ppb) {
3489 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3490 		res -= meta_blocks;
3491 		goto check_lfs;
3492 	}
3493 	meta_blocks += 1 + ppb;
3494 	upper_limit -= ppb * ppb;
3495 	/* tripple indirect blocks for the rest */
3496 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3497 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3498 	res -= meta_blocks;
3499 check_lfs:
3500 	res <<= bits;
3501 	if (res > MAX_LFS_FILESIZE)
3502 		res = MAX_LFS_FILESIZE;
3503 
3504 	return res;
3505 }
3506 
3507 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3508 				   ext4_fsblk_t logical_sb_block, int nr)
3509 {
3510 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3511 	ext4_group_t bg, first_meta_bg;
3512 	int has_super = 0;
3513 
3514 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3515 
3516 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3517 		return logical_sb_block + nr + 1;
3518 	bg = sbi->s_desc_per_block * nr;
3519 	if (ext4_bg_has_super(sb, bg))
3520 		has_super = 1;
3521 
3522 	/*
3523 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3524 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3525 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3526 	 * compensate.
3527 	 */
3528 	if (sb->s_blocksize == 1024 && nr == 0 &&
3529 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3530 		has_super++;
3531 
3532 	return (has_super + ext4_group_first_block_no(sb, bg));
3533 }
3534 
3535 /**
3536  * ext4_get_stripe_size: Get the stripe size.
3537  * @sbi: In memory super block info
3538  *
3539  * If we have specified it via mount option, then
3540  * use the mount option value. If the value specified at mount time is
3541  * greater than the blocks per group use the super block value.
3542  * If the super block value is greater than blocks per group return 0.
3543  * Allocator needs it be less than blocks per group.
3544  *
3545  */
3546 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3547 {
3548 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3549 	unsigned long stripe_width =
3550 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3551 	int ret;
3552 
3553 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3554 		ret = sbi->s_stripe;
3555 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3556 		ret = stripe_width;
3557 	else if (stride && stride <= sbi->s_blocks_per_group)
3558 		ret = stride;
3559 	else
3560 		ret = 0;
3561 
3562 	/*
3563 	 * If the stripe width is 1, this makes no sense and
3564 	 * we set it to 0 to turn off stripe handling code.
3565 	 */
3566 	if (ret <= 1)
3567 		ret = 0;
3568 
3569 	return ret;
3570 }
3571 
3572 /*
3573  * Check whether this filesystem can be mounted based on
3574  * the features present and the RDONLY/RDWR mount requested.
3575  * Returns 1 if this filesystem can be mounted as requested,
3576  * 0 if it cannot be.
3577  */
3578 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3579 {
3580 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3581 		ext4_msg(sb, KERN_ERR,
3582 			"Couldn't mount because of "
3583 			"unsupported optional features (%x)",
3584 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3585 			~EXT4_FEATURE_INCOMPAT_SUPP));
3586 		return 0;
3587 	}
3588 
3589 #if !IS_ENABLED(CONFIG_UNICODE)
3590 	if (ext4_has_feature_casefold(sb)) {
3591 		ext4_msg(sb, KERN_ERR,
3592 			 "Filesystem with casefold feature cannot be "
3593 			 "mounted without CONFIG_UNICODE");
3594 		return 0;
3595 	}
3596 #endif
3597 
3598 	if (readonly)
3599 		return 1;
3600 
3601 	if (ext4_has_feature_readonly(sb)) {
3602 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3603 		sb->s_flags |= SB_RDONLY;
3604 		return 1;
3605 	}
3606 
3607 	/* Check that feature set is OK for a read-write mount */
3608 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3609 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3610 			 "unsupported optional features (%x)",
3611 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3612 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3613 		return 0;
3614 	}
3615 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3616 		ext4_msg(sb, KERN_ERR,
3617 			 "Can't support bigalloc feature without "
3618 			 "extents feature\n");
3619 		return 0;
3620 	}
3621 
3622 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3623 	if (!readonly && (ext4_has_feature_quota(sb) ||
3624 			  ext4_has_feature_project(sb))) {
3625 		ext4_msg(sb, KERN_ERR,
3626 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3627 		return 0;
3628 	}
3629 #endif  /* CONFIG_QUOTA */
3630 	return 1;
3631 }
3632 
3633 /*
3634  * This function is called once a day if we have errors logged
3635  * on the file system
3636  */
3637 static void print_daily_error_info(struct timer_list *t)
3638 {
3639 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3640 	struct super_block *sb = sbi->s_sb;
3641 	struct ext4_super_block *es = sbi->s_es;
3642 
3643 	if (es->s_error_count)
3644 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3645 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3646 			 le32_to_cpu(es->s_error_count));
3647 	if (es->s_first_error_time) {
3648 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3649 		       sb->s_id,
3650 		       ext4_get_tstamp(es, s_first_error_time),
3651 		       (int) sizeof(es->s_first_error_func),
3652 		       es->s_first_error_func,
3653 		       le32_to_cpu(es->s_first_error_line));
3654 		if (es->s_first_error_ino)
3655 			printk(KERN_CONT ": inode %u",
3656 			       le32_to_cpu(es->s_first_error_ino));
3657 		if (es->s_first_error_block)
3658 			printk(KERN_CONT ": block %llu", (unsigned long long)
3659 			       le64_to_cpu(es->s_first_error_block));
3660 		printk(KERN_CONT "\n");
3661 	}
3662 	if (es->s_last_error_time) {
3663 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3664 		       sb->s_id,
3665 		       ext4_get_tstamp(es, s_last_error_time),
3666 		       (int) sizeof(es->s_last_error_func),
3667 		       es->s_last_error_func,
3668 		       le32_to_cpu(es->s_last_error_line));
3669 		if (es->s_last_error_ino)
3670 			printk(KERN_CONT ": inode %u",
3671 			       le32_to_cpu(es->s_last_error_ino));
3672 		if (es->s_last_error_block)
3673 			printk(KERN_CONT ": block %llu", (unsigned long long)
3674 			       le64_to_cpu(es->s_last_error_block));
3675 		printk(KERN_CONT "\n");
3676 	}
3677 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3678 }
3679 
3680 /* Find next suitable group and run ext4_init_inode_table */
3681 static int ext4_run_li_request(struct ext4_li_request *elr)
3682 {
3683 	struct ext4_group_desc *gdp = NULL;
3684 	struct super_block *sb = elr->lr_super;
3685 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3686 	ext4_group_t group = elr->lr_next_group;
3687 	unsigned int prefetch_ios = 0;
3688 	int ret = 0;
3689 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3690 	u64 start_time;
3691 
3692 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3693 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3694 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3695 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3696 		if (group >= elr->lr_next_group) {
3697 			ret = 1;
3698 			if (elr->lr_first_not_zeroed != ngroups &&
3699 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3700 				elr->lr_next_group = elr->lr_first_not_zeroed;
3701 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3702 				ret = 0;
3703 			}
3704 		}
3705 		return ret;
3706 	}
3707 
3708 	for (; group < ngroups; group++) {
3709 		gdp = ext4_get_group_desc(sb, group, NULL);
3710 		if (!gdp) {
3711 			ret = 1;
3712 			break;
3713 		}
3714 
3715 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3716 			break;
3717 	}
3718 
3719 	if (group >= ngroups)
3720 		ret = 1;
3721 
3722 	if (!ret) {
3723 		start_time = ktime_get_real_ns();
3724 		ret = ext4_init_inode_table(sb, group,
3725 					    elr->lr_timeout ? 0 : 1);
3726 		trace_ext4_lazy_itable_init(sb, group);
3727 		if (elr->lr_timeout == 0) {
3728 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3729 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3730 		}
3731 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3732 		elr->lr_next_group = group + 1;
3733 	}
3734 	return ret;
3735 }
3736 
3737 /*
3738  * Remove lr_request from the list_request and free the
3739  * request structure. Should be called with li_list_mtx held
3740  */
3741 static void ext4_remove_li_request(struct ext4_li_request *elr)
3742 {
3743 	if (!elr)
3744 		return;
3745 
3746 	list_del(&elr->lr_request);
3747 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3748 	kfree(elr);
3749 }
3750 
3751 static void ext4_unregister_li_request(struct super_block *sb)
3752 {
3753 	mutex_lock(&ext4_li_mtx);
3754 	if (!ext4_li_info) {
3755 		mutex_unlock(&ext4_li_mtx);
3756 		return;
3757 	}
3758 
3759 	mutex_lock(&ext4_li_info->li_list_mtx);
3760 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3761 	mutex_unlock(&ext4_li_info->li_list_mtx);
3762 	mutex_unlock(&ext4_li_mtx);
3763 }
3764 
3765 static struct task_struct *ext4_lazyinit_task;
3766 
3767 /*
3768  * This is the function where ext4lazyinit thread lives. It walks
3769  * through the request list searching for next scheduled filesystem.
3770  * When such a fs is found, run the lazy initialization request
3771  * (ext4_rn_li_request) and keep track of the time spend in this
3772  * function. Based on that time we compute next schedule time of
3773  * the request. When walking through the list is complete, compute
3774  * next waking time and put itself into sleep.
3775  */
3776 static int ext4_lazyinit_thread(void *arg)
3777 {
3778 	struct ext4_lazy_init *eli = arg;
3779 	struct list_head *pos, *n;
3780 	struct ext4_li_request *elr;
3781 	unsigned long next_wakeup, cur;
3782 
3783 	BUG_ON(NULL == eli);
3784 	set_freezable();
3785 
3786 cont_thread:
3787 	while (true) {
3788 		next_wakeup = MAX_JIFFY_OFFSET;
3789 
3790 		mutex_lock(&eli->li_list_mtx);
3791 		if (list_empty(&eli->li_request_list)) {
3792 			mutex_unlock(&eli->li_list_mtx);
3793 			goto exit_thread;
3794 		}
3795 		list_for_each_safe(pos, n, &eli->li_request_list) {
3796 			int err = 0;
3797 			int progress = 0;
3798 			elr = list_entry(pos, struct ext4_li_request,
3799 					 lr_request);
3800 
3801 			if (time_before(jiffies, elr->lr_next_sched)) {
3802 				if (time_before(elr->lr_next_sched, next_wakeup))
3803 					next_wakeup = elr->lr_next_sched;
3804 				continue;
3805 			}
3806 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3807 				if (sb_start_write_trylock(elr->lr_super)) {
3808 					progress = 1;
3809 					/*
3810 					 * We hold sb->s_umount, sb can not
3811 					 * be removed from the list, it is
3812 					 * now safe to drop li_list_mtx
3813 					 */
3814 					mutex_unlock(&eli->li_list_mtx);
3815 					err = ext4_run_li_request(elr);
3816 					sb_end_write(elr->lr_super);
3817 					mutex_lock(&eli->li_list_mtx);
3818 					n = pos->next;
3819 				}
3820 				up_read((&elr->lr_super->s_umount));
3821 			}
3822 			/* error, remove the lazy_init job */
3823 			if (err) {
3824 				ext4_remove_li_request(elr);
3825 				continue;
3826 			}
3827 			if (!progress) {
3828 				elr->lr_next_sched = jiffies +
3829 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3830 			}
3831 			if (time_before(elr->lr_next_sched, next_wakeup))
3832 				next_wakeup = elr->lr_next_sched;
3833 		}
3834 		mutex_unlock(&eli->li_list_mtx);
3835 
3836 		try_to_freeze();
3837 
3838 		cur = jiffies;
3839 		if ((time_after_eq(cur, next_wakeup)) ||
3840 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3841 			cond_resched();
3842 			continue;
3843 		}
3844 
3845 		schedule_timeout_interruptible(next_wakeup - cur);
3846 
3847 		if (kthread_should_stop()) {
3848 			ext4_clear_request_list();
3849 			goto exit_thread;
3850 		}
3851 	}
3852 
3853 exit_thread:
3854 	/*
3855 	 * It looks like the request list is empty, but we need
3856 	 * to check it under the li_list_mtx lock, to prevent any
3857 	 * additions into it, and of course we should lock ext4_li_mtx
3858 	 * to atomically free the list and ext4_li_info, because at
3859 	 * this point another ext4 filesystem could be registering
3860 	 * new one.
3861 	 */
3862 	mutex_lock(&ext4_li_mtx);
3863 	mutex_lock(&eli->li_list_mtx);
3864 	if (!list_empty(&eli->li_request_list)) {
3865 		mutex_unlock(&eli->li_list_mtx);
3866 		mutex_unlock(&ext4_li_mtx);
3867 		goto cont_thread;
3868 	}
3869 	mutex_unlock(&eli->li_list_mtx);
3870 	kfree(ext4_li_info);
3871 	ext4_li_info = NULL;
3872 	mutex_unlock(&ext4_li_mtx);
3873 
3874 	return 0;
3875 }
3876 
3877 static void ext4_clear_request_list(void)
3878 {
3879 	struct list_head *pos, *n;
3880 	struct ext4_li_request *elr;
3881 
3882 	mutex_lock(&ext4_li_info->li_list_mtx);
3883 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3884 		elr = list_entry(pos, struct ext4_li_request,
3885 				 lr_request);
3886 		ext4_remove_li_request(elr);
3887 	}
3888 	mutex_unlock(&ext4_li_info->li_list_mtx);
3889 }
3890 
3891 static int ext4_run_lazyinit_thread(void)
3892 {
3893 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3894 					 ext4_li_info, "ext4lazyinit");
3895 	if (IS_ERR(ext4_lazyinit_task)) {
3896 		int err = PTR_ERR(ext4_lazyinit_task);
3897 		ext4_clear_request_list();
3898 		kfree(ext4_li_info);
3899 		ext4_li_info = NULL;
3900 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3901 				 "initialization thread\n",
3902 				 err);
3903 		return err;
3904 	}
3905 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3906 	return 0;
3907 }
3908 
3909 /*
3910  * Check whether it make sense to run itable init. thread or not.
3911  * If there is at least one uninitialized inode table, return
3912  * corresponding group number, else the loop goes through all
3913  * groups and return total number of groups.
3914  */
3915 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3916 {
3917 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3918 	struct ext4_group_desc *gdp = NULL;
3919 
3920 	if (!ext4_has_group_desc_csum(sb))
3921 		return ngroups;
3922 
3923 	for (group = 0; group < ngroups; group++) {
3924 		gdp = ext4_get_group_desc(sb, group, NULL);
3925 		if (!gdp)
3926 			continue;
3927 
3928 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3929 			break;
3930 	}
3931 
3932 	return group;
3933 }
3934 
3935 static int ext4_li_info_new(void)
3936 {
3937 	struct ext4_lazy_init *eli = NULL;
3938 
3939 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3940 	if (!eli)
3941 		return -ENOMEM;
3942 
3943 	INIT_LIST_HEAD(&eli->li_request_list);
3944 	mutex_init(&eli->li_list_mtx);
3945 
3946 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3947 
3948 	ext4_li_info = eli;
3949 
3950 	return 0;
3951 }
3952 
3953 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3954 					    ext4_group_t start)
3955 {
3956 	struct ext4_li_request *elr;
3957 
3958 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3959 	if (!elr)
3960 		return NULL;
3961 
3962 	elr->lr_super = sb;
3963 	elr->lr_first_not_zeroed = start;
3964 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3965 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3966 		elr->lr_next_group = start;
3967 	} else {
3968 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3969 	}
3970 
3971 	/*
3972 	 * Randomize first schedule time of the request to
3973 	 * spread the inode table initialization requests
3974 	 * better.
3975 	 */
3976 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3977 	return elr;
3978 }
3979 
3980 int ext4_register_li_request(struct super_block *sb,
3981 			     ext4_group_t first_not_zeroed)
3982 {
3983 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3984 	struct ext4_li_request *elr = NULL;
3985 	ext4_group_t ngroups = sbi->s_groups_count;
3986 	int ret = 0;
3987 
3988 	mutex_lock(&ext4_li_mtx);
3989 	if (sbi->s_li_request != NULL) {
3990 		/*
3991 		 * Reset timeout so it can be computed again, because
3992 		 * s_li_wait_mult might have changed.
3993 		 */
3994 		sbi->s_li_request->lr_timeout = 0;
3995 		goto out;
3996 	}
3997 
3998 	if (sb_rdonly(sb) ||
3999 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4000 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4001 		goto out;
4002 
4003 	elr = ext4_li_request_new(sb, first_not_zeroed);
4004 	if (!elr) {
4005 		ret = -ENOMEM;
4006 		goto out;
4007 	}
4008 
4009 	if (NULL == ext4_li_info) {
4010 		ret = ext4_li_info_new();
4011 		if (ret)
4012 			goto out;
4013 	}
4014 
4015 	mutex_lock(&ext4_li_info->li_list_mtx);
4016 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4017 	mutex_unlock(&ext4_li_info->li_list_mtx);
4018 
4019 	sbi->s_li_request = elr;
4020 	/*
4021 	 * set elr to NULL here since it has been inserted to
4022 	 * the request_list and the removal and free of it is
4023 	 * handled by ext4_clear_request_list from now on.
4024 	 */
4025 	elr = NULL;
4026 
4027 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4028 		ret = ext4_run_lazyinit_thread();
4029 		if (ret)
4030 			goto out;
4031 	}
4032 out:
4033 	mutex_unlock(&ext4_li_mtx);
4034 	if (ret)
4035 		kfree(elr);
4036 	return ret;
4037 }
4038 
4039 /*
4040  * We do not need to lock anything since this is called on
4041  * module unload.
4042  */
4043 static void ext4_destroy_lazyinit_thread(void)
4044 {
4045 	/*
4046 	 * If thread exited earlier
4047 	 * there's nothing to be done.
4048 	 */
4049 	if (!ext4_li_info || !ext4_lazyinit_task)
4050 		return;
4051 
4052 	kthread_stop(ext4_lazyinit_task);
4053 }
4054 
4055 static int set_journal_csum_feature_set(struct super_block *sb)
4056 {
4057 	int ret = 1;
4058 	int compat, incompat;
4059 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4060 
4061 	if (ext4_has_metadata_csum(sb)) {
4062 		/* journal checksum v3 */
4063 		compat = 0;
4064 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4065 	} else {
4066 		/* journal checksum v1 */
4067 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4068 		incompat = 0;
4069 	}
4070 
4071 	jbd2_journal_clear_features(sbi->s_journal,
4072 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4073 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4074 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4075 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4076 		ret = jbd2_journal_set_features(sbi->s_journal,
4077 				compat, 0,
4078 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4079 				incompat);
4080 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4081 		ret = jbd2_journal_set_features(sbi->s_journal,
4082 				compat, 0,
4083 				incompat);
4084 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4085 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4086 	} else {
4087 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4088 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4089 	}
4090 
4091 	return ret;
4092 }
4093 
4094 /*
4095  * Note: calculating the overhead so we can be compatible with
4096  * historical BSD practice is quite difficult in the face of
4097  * clusters/bigalloc.  This is because multiple metadata blocks from
4098  * different block group can end up in the same allocation cluster.
4099  * Calculating the exact overhead in the face of clustered allocation
4100  * requires either O(all block bitmaps) in memory or O(number of block
4101  * groups**2) in time.  We will still calculate the superblock for
4102  * older file systems --- and if we come across with a bigalloc file
4103  * system with zero in s_overhead_clusters the estimate will be close to
4104  * correct especially for very large cluster sizes --- but for newer
4105  * file systems, it's better to calculate this figure once at mkfs
4106  * time, and store it in the superblock.  If the superblock value is
4107  * present (even for non-bigalloc file systems), we will use it.
4108  */
4109 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4110 			  char *buf)
4111 {
4112 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4113 	struct ext4_group_desc	*gdp;
4114 	ext4_fsblk_t		first_block, last_block, b;
4115 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4116 	int			s, j, count = 0;
4117 	int			has_super = ext4_bg_has_super(sb, grp);
4118 
4119 	if (!ext4_has_feature_bigalloc(sb))
4120 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4121 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4122 			sbi->s_itb_per_group + 2);
4123 
4124 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4125 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4126 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4127 	for (i = 0; i < ngroups; i++) {
4128 		gdp = ext4_get_group_desc(sb, i, NULL);
4129 		b = ext4_block_bitmap(sb, gdp);
4130 		if (b >= first_block && b <= last_block) {
4131 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4132 			count++;
4133 		}
4134 		b = ext4_inode_bitmap(sb, gdp);
4135 		if (b >= first_block && b <= last_block) {
4136 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4137 			count++;
4138 		}
4139 		b = ext4_inode_table(sb, gdp);
4140 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4141 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4142 				int c = EXT4_B2C(sbi, b - first_block);
4143 				ext4_set_bit(c, buf);
4144 				count++;
4145 			}
4146 		if (i != grp)
4147 			continue;
4148 		s = 0;
4149 		if (ext4_bg_has_super(sb, grp)) {
4150 			ext4_set_bit(s++, buf);
4151 			count++;
4152 		}
4153 		j = ext4_bg_num_gdb(sb, grp);
4154 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4155 			ext4_error(sb, "Invalid number of block group "
4156 				   "descriptor blocks: %d", j);
4157 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4158 		}
4159 		count += j;
4160 		for (; j > 0; j--)
4161 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4162 	}
4163 	if (!count)
4164 		return 0;
4165 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4166 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4167 }
4168 
4169 /*
4170  * Compute the overhead and stash it in sbi->s_overhead
4171  */
4172 int ext4_calculate_overhead(struct super_block *sb)
4173 {
4174 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4175 	struct ext4_super_block *es = sbi->s_es;
4176 	struct inode *j_inode;
4177 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4178 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4179 	ext4_fsblk_t overhead = 0;
4180 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4181 
4182 	if (!buf)
4183 		return -ENOMEM;
4184 
4185 	/*
4186 	 * Compute the overhead (FS structures).  This is constant
4187 	 * for a given filesystem unless the number of block groups
4188 	 * changes so we cache the previous value until it does.
4189 	 */
4190 
4191 	/*
4192 	 * All of the blocks before first_data_block are overhead
4193 	 */
4194 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4195 
4196 	/*
4197 	 * Add the overhead found in each block group
4198 	 */
4199 	for (i = 0; i < ngroups; i++) {
4200 		int blks;
4201 
4202 		blks = count_overhead(sb, i, buf);
4203 		overhead += blks;
4204 		if (blks)
4205 			memset(buf, 0, PAGE_SIZE);
4206 		cond_resched();
4207 	}
4208 
4209 	/*
4210 	 * Add the internal journal blocks whether the journal has been
4211 	 * loaded or not
4212 	 */
4213 	if (sbi->s_journal && !sbi->s_journal_bdev_file)
4214 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4215 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4216 		/* j_inum for internal journal is non-zero */
4217 		j_inode = ext4_get_journal_inode(sb, j_inum);
4218 		if (!IS_ERR(j_inode)) {
4219 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4220 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4221 			iput(j_inode);
4222 		} else {
4223 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4224 		}
4225 	}
4226 	sbi->s_overhead = overhead;
4227 	smp_wmb();
4228 	free_page((unsigned long) buf);
4229 	return 0;
4230 }
4231 
4232 static void ext4_set_resv_clusters(struct super_block *sb)
4233 {
4234 	ext4_fsblk_t resv_clusters;
4235 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4236 
4237 	/*
4238 	 * There's no need to reserve anything when we aren't using extents.
4239 	 * The space estimates are exact, there are no unwritten extents,
4240 	 * hole punching doesn't need new metadata... This is needed especially
4241 	 * to keep ext2/3 backward compatibility.
4242 	 */
4243 	if (!ext4_has_feature_extents(sb))
4244 		return;
4245 	/*
4246 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4247 	 * This should cover the situations where we can not afford to run
4248 	 * out of space like for example punch hole, or converting
4249 	 * unwritten extents in delalloc path. In most cases such
4250 	 * allocation would require 1, or 2 blocks, higher numbers are
4251 	 * very rare.
4252 	 */
4253 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4254 			 sbi->s_cluster_bits);
4255 
4256 	do_div(resv_clusters, 50);
4257 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4258 
4259 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4260 }
4261 
4262 static const char *ext4_quota_mode(struct super_block *sb)
4263 {
4264 #ifdef CONFIG_QUOTA
4265 	if (!ext4_quota_capable(sb))
4266 		return "none";
4267 
4268 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4269 		return "journalled";
4270 	else
4271 		return "writeback";
4272 #else
4273 	return "disabled";
4274 #endif
4275 }
4276 
4277 static void ext4_setup_csum_trigger(struct super_block *sb,
4278 				    enum ext4_journal_trigger_type type,
4279 				    void (*trigger)(
4280 					struct jbd2_buffer_trigger_type *type,
4281 					struct buffer_head *bh,
4282 					void *mapped_data,
4283 					size_t size))
4284 {
4285 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4286 
4287 	sbi->s_journal_triggers[type].sb = sb;
4288 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4289 }
4290 
4291 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4292 {
4293 	if (!sbi)
4294 		return;
4295 
4296 	kfree(sbi->s_blockgroup_lock);
4297 	fs_put_dax(sbi->s_daxdev, NULL);
4298 	kfree(sbi);
4299 }
4300 
4301 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4302 {
4303 	struct ext4_sb_info *sbi;
4304 
4305 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4306 	if (!sbi)
4307 		return NULL;
4308 
4309 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4310 					   NULL, NULL);
4311 
4312 	sbi->s_blockgroup_lock =
4313 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4314 
4315 	if (!sbi->s_blockgroup_lock)
4316 		goto err_out;
4317 
4318 	sb->s_fs_info = sbi;
4319 	sbi->s_sb = sb;
4320 	return sbi;
4321 err_out:
4322 	fs_put_dax(sbi->s_daxdev, NULL);
4323 	kfree(sbi);
4324 	return NULL;
4325 }
4326 
4327 static void ext4_set_def_opts(struct super_block *sb,
4328 			      struct ext4_super_block *es)
4329 {
4330 	unsigned long def_mount_opts;
4331 
4332 	/* Set defaults before we parse the mount options */
4333 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4334 	set_opt(sb, INIT_INODE_TABLE);
4335 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4336 		set_opt(sb, DEBUG);
4337 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4338 		set_opt(sb, GRPID);
4339 	if (def_mount_opts & EXT4_DEFM_UID16)
4340 		set_opt(sb, NO_UID32);
4341 	/* xattr user namespace & acls are now defaulted on */
4342 	set_opt(sb, XATTR_USER);
4343 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4344 	set_opt(sb, POSIX_ACL);
4345 #endif
4346 	if (ext4_has_feature_fast_commit(sb))
4347 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4348 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4349 	if (ext4_has_metadata_csum(sb))
4350 		set_opt(sb, JOURNAL_CHECKSUM);
4351 
4352 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4353 		set_opt(sb, JOURNAL_DATA);
4354 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4355 		set_opt(sb, ORDERED_DATA);
4356 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4357 		set_opt(sb, WRITEBACK_DATA);
4358 
4359 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4360 		set_opt(sb, ERRORS_PANIC);
4361 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4362 		set_opt(sb, ERRORS_CONT);
4363 	else
4364 		set_opt(sb, ERRORS_RO);
4365 	/* block_validity enabled by default; disable with noblock_validity */
4366 	set_opt(sb, BLOCK_VALIDITY);
4367 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4368 		set_opt(sb, DISCARD);
4369 
4370 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4371 		set_opt(sb, BARRIER);
4372 
4373 	/*
4374 	 * enable delayed allocation by default
4375 	 * Use -o nodelalloc to turn it off
4376 	 */
4377 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4378 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4379 		set_opt(sb, DELALLOC);
4380 
4381 	if (sb->s_blocksize <= PAGE_SIZE)
4382 		set_opt(sb, DIOREAD_NOLOCK);
4383 }
4384 
4385 static int ext4_handle_clustersize(struct super_block *sb)
4386 {
4387 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4388 	struct ext4_super_block *es = sbi->s_es;
4389 	int clustersize;
4390 
4391 	/* Handle clustersize */
4392 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4393 	if (ext4_has_feature_bigalloc(sb)) {
4394 		if (clustersize < sb->s_blocksize) {
4395 			ext4_msg(sb, KERN_ERR,
4396 				 "cluster size (%d) smaller than "
4397 				 "block size (%lu)", clustersize, sb->s_blocksize);
4398 			return -EINVAL;
4399 		}
4400 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4401 			le32_to_cpu(es->s_log_block_size);
4402 	} else {
4403 		if (clustersize != sb->s_blocksize) {
4404 			ext4_msg(sb, KERN_ERR,
4405 				 "fragment/cluster size (%d) != "
4406 				 "block size (%lu)", clustersize, sb->s_blocksize);
4407 			return -EINVAL;
4408 		}
4409 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4410 			ext4_msg(sb, KERN_ERR,
4411 				 "#blocks per group too big: %lu",
4412 				 sbi->s_blocks_per_group);
4413 			return -EINVAL;
4414 		}
4415 		sbi->s_cluster_bits = 0;
4416 	}
4417 	sbi->s_clusters_per_group = le32_to_cpu(es->s_clusters_per_group);
4418 	if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4419 		ext4_msg(sb, KERN_ERR, "#clusters per group too big: %lu",
4420 			 sbi->s_clusters_per_group);
4421 		return -EINVAL;
4422 	}
4423 	if (sbi->s_blocks_per_group !=
4424 	    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4425 		ext4_msg(sb, KERN_ERR,
4426 			 "blocks per group (%lu) and clusters per group (%lu) inconsistent",
4427 			 sbi->s_blocks_per_group, sbi->s_clusters_per_group);
4428 		return -EINVAL;
4429 	}
4430 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4431 
4432 	/* Do we have standard group size of clustersize * 8 blocks ? */
4433 	if (sbi->s_blocks_per_group == clustersize << 3)
4434 		set_opt2(sb, STD_GROUP_SIZE);
4435 
4436 	return 0;
4437 }
4438 
4439 static void ext4_fast_commit_init(struct super_block *sb)
4440 {
4441 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4442 
4443 	/* Initialize fast commit stuff */
4444 	atomic_set(&sbi->s_fc_subtid, 0);
4445 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4446 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4447 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4448 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4449 	sbi->s_fc_bytes = 0;
4450 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4451 	sbi->s_fc_ineligible_tid = 0;
4452 	spin_lock_init(&sbi->s_fc_lock);
4453 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4454 	sbi->s_fc_replay_state.fc_regions = NULL;
4455 	sbi->s_fc_replay_state.fc_regions_size = 0;
4456 	sbi->s_fc_replay_state.fc_regions_used = 0;
4457 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4458 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4459 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4460 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4461 }
4462 
4463 static int ext4_inode_info_init(struct super_block *sb,
4464 				struct ext4_super_block *es)
4465 {
4466 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4467 
4468 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4469 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4470 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4471 	} else {
4472 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4473 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4474 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4475 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4476 				 sbi->s_first_ino);
4477 			return -EINVAL;
4478 		}
4479 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4480 		    (!is_power_of_2(sbi->s_inode_size)) ||
4481 		    (sbi->s_inode_size > sb->s_blocksize)) {
4482 			ext4_msg(sb, KERN_ERR,
4483 			       "unsupported inode size: %d",
4484 			       sbi->s_inode_size);
4485 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4486 			return -EINVAL;
4487 		}
4488 		/*
4489 		 * i_atime_extra is the last extra field available for
4490 		 * [acm]times in struct ext4_inode. Checking for that
4491 		 * field should suffice to ensure we have extra space
4492 		 * for all three.
4493 		 */
4494 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4495 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4496 			sb->s_time_gran = 1;
4497 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4498 		} else {
4499 			sb->s_time_gran = NSEC_PER_SEC;
4500 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4501 		}
4502 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4503 	}
4504 
4505 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4506 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4507 			EXT4_GOOD_OLD_INODE_SIZE;
4508 		if (ext4_has_feature_extra_isize(sb)) {
4509 			unsigned v, max = (sbi->s_inode_size -
4510 					   EXT4_GOOD_OLD_INODE_SIZE);
4511 
4512 			v = le16_to_cpu(es->s_want_extra_isize);
4513 			if (v > max) {
4514 				ext4_msg(sb, KERN_ERR,
4515 					 "bad s_want_extra_isize: %d", v);
4516 				return -EINVAL;
4517 			}
4518 			if (sbi->s_want_extra_isize < v)
4519 				sbi->s_want_extra_isize = v;
4520 
4521 			v = le16_to_cpu(es->s_min_extra_isize);
4522 			if (v > max) {
4523 				ext4_msg(sb, KERN_ERR,
4524 					 "bad s_min_extra_isize: %d", v);
4525 				return -EINVAL;
4526 			}
4527 			if (sbi->s_want_extra_isize < v)
4528 				sbi->s_want_extra_isize = v;
4529 		}
4530 	}
4531 
4532 	return 0;
4533 }
4534 
4535 #if IS_ENABLED(CONFIG_UNICODE)
4536 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4537 {
4538 	const struct ext4_sb_encodings *encoding_info;
4539 	struct unicode_map *encoding;
4540 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4541 
4542 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4543 		return 0;
4544 
4545 	encoding_info = ext4_sb_read_encoding(es);
4546 	if (!encoding_info) {
4547 		ext4_msg(sb, KERN_ERR,
4548 			"Encoding requested by superblock is unknown");
4549 		return -EINVAL;
4550 	}
4551 
4552 	encoding = utf8_load(encoding_info->version);
4553 	if (IS_ERR(encoding)) {
4554 		ext4_msg(sb, KERN_ERR,
4555 			"can't mount with superblock charset: %s-%u.%u.%u "
4556 			"not supported by the kernel. flags: 0x%x.",
4557 			encoding_info->name,
4558 			unicode_major(encoding_info->version),
4559 			unicode_minor(encoding_info->version),
4560 			unicode_rev(encoding_info->version),
4561 			encoding_flags);
4562 		return -EINVAL;
4563 	}
4564 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4565 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4566 		unicode_major(encoding_info->version),
4567 		unicode_minor(encoding_info->version),
4568 		unicode_rev(encoding_info->version),
4569 		encoding_flags);
4570 
4571 	sb->s_encoding = encoding;
4572 	sb->s_encoding_flags = encoding_flags;
4573 
4574 	return 0;
4575 }
4576 #else
4577 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4578 {
4579 	return 0;
4580 }
4581 #endif
4582 
4583 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4584 {
4585 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4586 
4587 	/* Warn if metadata_csum and gdt_csum are both set. */
4588 	if (ext4_has_feature_metadata_csum(sb) &&
4589 	    ext4_has_feature_gdt_csum(sb))
4590 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4591 			     "redundant flags; please run fsck.");
4592 
4593 	/* Check for a known checksum algorithm */
4594 	if (!ext4_verify_csum_type(sb, es)) {
4595 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4596 			 "unknown checksum algorithm.");
4597 		return -EINVAL;
4598 	}
4599 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4600 				ext4_orphan_file_block_trigger);
4601 
4602 	/* Load the checksum driver */
4603 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4604 	if (IS_ERR(sbi->s_chksum_driver)) {
4605 		int ret = PTR_ERR(sbi->s_chksum_driver);
4606 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4607 		sbi->s_chksum_driver = NULL;
4608 		return ret;
4609 	}
4610 
4611 	/* Check superblock checksum */
4612 	if (!ext4_superblock_csum_verify(sb, es)) {
4613 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4614 			 "invalid superblock checksum.  Run e2fsck?");
4615 		return -EFSBADCRC;
4616 	}
4617 
4618 	/* Precompute checksum seed for all metadata */
4619 	if (ext4_has_feature_csum_seed(sb))
4620 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4621 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4622 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4623 					       sizeof(es->s_uuid));
4624 	return 0;
4625 }
4626 
4627 static int ext4_check_feature_compatibility(struct super_block *sb,
4628 					    struct ext4_super_block *es,
4629 					    int silent)
4630 {
4631 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4632 
4633 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4634 	    (ext4_has_compat_features(sb) ||
4635 	     ext4_has_ro_compat_features(sb) ||
4636 	     ext4_has_incompat_features(sb)))
4637 		ext4_msg(sb, KERN_WARNING,
4638 		       "feature flags set on rev 0 fs, "
4639 		       "running e2fsck is recommended");
4640 
4641 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4642 		set_opt2(sb, HURD_COMPAT);
4643 		if (ext4_has_feature_64bit(sb)) {
4644 			ext4_msg(sb, KERN_ERR,
4645 				 "The Hurd can't support 64-bit file systems");
4646 			return -EINVAL;
4647 		}
4648 
4649 		/*
4650 		 * ea_inode feature uses l_i_version field which is not
4651 		 * available in HURD_COMPAT mode.
4652 		 */
4653 		if (ext4_has_feature_ea_inode(sb)) {
4654 			ext4_msg(sb, KERN_ERR,
4655 				 "ea_inode feature is not supported for Hurd");
4656 			return -EINVAL;
4657 		}
4658 	}
4659 
4660 	if (IS_EXT2_SB(sb)) {
4661 		if (ext2_feature_set_ok(sb))
4662 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4663 				 "using the ext4 subsystem");
4664 		else {
4665 			/*
4666 			 * If we're probing be silent, if this looks like
4667 			 * it's actually an ext[34] filesystem.
4668 			 */
4669 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4670 				return -EINVAL;
4671 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4672 				 "to feature incompatibilities");
4673 			return -EINVAL;
4674 		}
4675 	}
4676 
4677 	if (IS_EXT3_SB(sb)) {
4678 		if (ext3_feature_set_ok(sb))
4679 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4680 				 "using the ext4 subsystem");
4681 		else {
4682 			/*
4683 			 * If we're probing be silent, if this looks like
4684 			 * it's actually an ext4 filesystem.
4685 			 */
4686 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4687 				return -EINVAL;
4688 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4689 				 "to feature incompatibilities");
4690 			return -EINVAL;
4691 		}
4692 	}
4693 
4694 	/*
4695 	 * Check feature flags regardless of the revision level, since we
4696 	 * previously didn't change the revision level when setting the flags,
4697 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4698 	 */
4699 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4700 		return -EINVAL;
4701 
4702 	if (sbi->s_daxdev) {
4703 		if (sb->s_blocksize == PAGE_SIZE)
4704 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4705 		else
4706 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4707 	}
4708 
4709 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4710 		if (ext4_has_feature_inline_data(sb)) {
4711 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4712 					" that may contain inline data");
4713 			return -EINVAL;
4714 		}
4715 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4716 			ext4_msg(sb, KERN_ERR,
4717 				"DAX unsupported by block device.");
4718 			return -EINVAL;
4719 		}
4720 	}
4721 
4722 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4723 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4724 			 es->s_encryption_level);
4725 		return -EINVAL;
4726 	}
4727 
4728 	return 0;
4729 }
4730 
4731 static int ext4_check_geometry(struct super_block *sb,
4732 			       struct ext4_super_block *es)
4733 {
4734 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4735 	__u64 blocks_count;
4736 	int err;
4737 
4738 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4739 		ext4_msg(sb, KERN_ERR,
4740 			 "Number of reserved GDT blocks insanely large: %d",
4741 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4742 		return -EINVAL;
4743 	}
4744 	/*
4745 	 * Test whether we have more sectors than will fit in sector_t,
4746 	 * and whether the max offset is addressable by the page cache.
4747 	 */
4748 	err = generic_check_addressable(sb->s_blocksize_bits,
4749 					ext4_blocks_count(es));
4750 	if (err) {
4751 		ext4_msg(sb, KERN_ERR, "filesystem"
4752 			 " too large to mount safely on this system");
4753 		return err;
4754 	}
4755 
4756 	/* check blocks count against device size */
4757 	blocks_count = sb_bdev_nr_blocks(sb);
4758 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4759 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4760 		       "exceeds size of device (%llu blocks)",
4761 		       ext4_blocks_count(es), blocks_count);
4762 		return -EINVAL;
4763 	}
4764 
4765 	/*
4766 	 * It makes no sense for the first data block to be beyond the end
4767 	 * of the filesystem.
4768 	 */
4769 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4770 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4771 			 "block %u is beyond end of filesystem (%llu)",
4772 			 le32_to_cpu(es->s_first_data_block),
4773 			 ext4_blocks_count(es));
4774 		return -EINVAL;
4775 	}
4776 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4777 	    (sbi->s_cluster_ratio == 1)) {
4778 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4779 			 "block is 0 with a 1k block and cluster size");
4780 		return -EINVAL;
4781 	}
4782 
4783 	blocks_count = (ext4_blocks_count(es) -
4784 			le32_to_cpu(es->s_first_data_block) +
4785 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4786 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4787 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4788 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4789 		       "(block count %llu, first data block %u, "
4790 		       "blocks per group %lu)", blocks_count,
4791 		       ext4_blocks_count(es),
4792 		       le32_to_cpu(es->s_first_data_block),
4793 		       EXT4_BLOCKS_PER_GROUP(sb));
4794 		return -EINVAL;
4795 	}
4796 	sbi->s_groups_count = blocks_count;
4797 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4798 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4799 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4800 	    le32_to_cpu(es->s_inodes_count)) {
4801 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4802 			 le32_to_cpu(es->s_inodes_count),
4803 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4804 		return -EINVAL;
4805 	}
4806 
4807 	return 0;
4808 }
4809 
4810 static int ext4_group_desc_init(struct super_block *sb,
4811 				struct ext4_super_block *es,
4812 				ext4_fsblk_t logical_sb_block,
4813 				ext4_group_t *first_not_zeroed)
4814 {
4815 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4816 	unsigned int db_count;
4817 	ext4_fsblk_t block;
4818 	int i;
4819 
4820 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4821 		   EXT4_DESC_PER_BLOCK(sb);
4822 	if (ext4_has_feature_meta_bg(sb)) {
4823 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4824 			ext4_msg(sb, KERN_WARNING,
4825 				 "first meta block group too large: %u "
4826 				 "(group descriptor block count %u)",
4827 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4828 			return -EINVAL;
4829 		}
4830 	}
4831 	rcu_assign_pointer(sbi->s_group_desc,
4832 			   kvmalloc_array(db_count,
4833 					  sizeof(struct buffer_head *),
4834 					  GFP_KERNEL));
4835 	if (sbi->s_group_desc == NULL) {
4836 		ext4_msg(sb, KERN_ERR, "not enough memory");
4837 		return -ENOMEM;
4838 	}
4839 
4840 	bgl_lock_init(sbi->s_blockgroup_lock);
4841 
4842 	/* Pre-read the descriptors into the buffer cache */
4843 	for (i = 0; i < db_count; i++) {
4844 		block = descriptor_loc(sb, logical_sb_block, i);
4845 		ext4_sb_breadahead_unmovable(sb, block);
4846 	}
4847 
4848 	for (i = 0; i < db_count; i++) {
4849 		struct buffer_head *bh;
4850 
4851 		block = descriptor_loc(sb, logical_sb_block, i);
4852 		bh = ext4_sb_bread_unmovable(sb, block);
4853 		if (IS_ERR(bh)) {
4854 			ext4_msg(sb, KERN_ERR,
4855 			       "can't read group descriptor %d", i);
4856 			sbi->s_gdb_count = i;
4857 			return PTR_ERR(bh);
4858 		}
4859 		rcu_read_lock();
4860 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4861 		rcu_read_unlock();
4862 	}
4863 	sbi->s_gdb_count = db_count;
4864 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4865 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4866 		return -EFSCORRUPTED;
4867 	}
4868 
4869 	return 0;
4870 }
4871 
4872 static int ext4_load_and_init_journal(struct super_block *sb,
4873 				      struct ext4_super_block *es,
4874 				      struct ext4_fs_context *ctx)
4875 {
4876 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4877 	int err;
4878 
4879 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4880 	if (err)
4881 		return err;
4882 
4883 	if (ext4_has_feature_64bit(sb) &&
4884 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4885 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4886 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4887 		goto out;
4888 	}
4889 
4890 	if (!set_journal_csum_feature_set(sb)) {
4891 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4892 			 "feature set");
4893 		goto out;
4894 	}
4895 
4896 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4897 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4898 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4899 		ext4_msg(sb, KERN_ERR,
4900 			"Failed to set fast commit journal feature");
4901 		goto out;
4902 	}
4903 
4904 	/* We have now updated the journal if required, so we can
4905 	 * validate the data journaling mode. */
4906 	switch (test_opt(sb, DATA_FLAGS)) {
4907 	case 0:
4908 		/* No mode set, assume a default based on the journal
4909 		 * capabilities: ORDERED_DATA if the journal can
4910 		 * cope, else JOURNAL_DATA
4911 		 */
4912 		if (jbd2_journal_check_available_features
4913 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4914 			set_opt(sb, ORDERED_DATA);
4915 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4916 		} else {
4917 			set_opt(sb, JOURNAL_DATA);
4918 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4919 		}
4920 		break;
4921 
4922 	case EXT4_MOUNT_ORDERED_DATA:
4923 	case EXT4_MOUNT_WRITEBACK_DATA:
4924 		if (!jbd2_journal_check_available_features
4925 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4926 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4927 			       "requested data journaling mode");
4928 			goto out;
4929 		}
4930 		break;
4931 	default:
4932 		break;
4933 	}
4934 
4935 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4936 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4937 		ext4_msg(sb, KERN_ERR, "can't mount with "
4938 			"journal_async_commit in data=ordered mode");
4939 		goto out;
4940 	}
4941 
4942 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4943 
4944 	sbi->s_journal->j_submit_inode_data_buffers =
4945 		ext4_journal_submit_inode_data_buffers;
4946 	sbi->s_journal->j_finish_inode_data_buffers =
4947 		ext4_journal_finish_inode_data_buffers;
4948 
4949 	return 0;
4950 
4951 out:
4952 	/* flush s_sb_upd_work before destroying the journal. */
4953 	flush_work(&sbi->s_sb_upd_work);
4954 	jbd2_journal_destroy(sbi->s_journal);
4955 	sbi->s_journal = NULL;
4956 	return -EINVAL;
4957 }
4958 
4959 static int ext4_check_journal_data_mode(struct super_block *sb)
4960 {
4961 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4962 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4963 			    "data=journal disables delayed allocation, "
4964 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4965 		/* can't mount with both data=journal and dioread_nolock. */
4966 		clear_opt(sb, DIOREAD_NOLOCK);
4967 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4968 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4969 			ext4_msg(sb, KERN_ERR, "can't mount with "
4970 				 "both data=journal and delalloc");
4971 			return -EINVAL;
4972 		}
4973 		if (test_opt(sb, DAX_ALWAYS)) {
4974 			ext4_msg(sb, KERN_ERR, "can't mount with "
4975 				 "both data=journal and dax");
4976 			return -EINVAL;
4977 		}
4978 		if (ext4_has_feature_encrypt(sb)) {
4979 			ext4_msg(sb, KERN_WARNING,
4980 				 "encrypted files will use data=ordered "
4981 				 "instead of data journaling mode");
4982 		}
4983 		if (test_opt(sb, DELALLOC))
4984 			clear_opt(sb, DELALLOC);
4985 	} else {
4986 		sb->s_iflags |= SB_I_CGROUPWB;
4987 	}
4988 
4989 	return 0;
4990 }
4991 
4992 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
4993 			   int silent)
4994 {
4995 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4996 	struct ext4_super_block *es;
4997 	ext4_fsblk_t logical_sb_block;
4998 	unsigned long offset = 0;
4999 	struct buffer_head *bh;
5000 	int ret = -EINVAL;
5001 	int blocksize;
5002 
5003 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5004 	if (!blocksize) {
5005 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5006 		return -EINVAL;
5007 	}
5008 
5009 	/*
5010 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5011 	 * block sizes.  We need to calculate the offset from buffer start.
5012 	 */
5013 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5014 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5015 		offset = do_div(logical_sb_block, blocksize);
5016 	} else {
5017 		logical_sb_block = sbi->s_sb_block;
5018 	}
5019 
5020 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5021 	if (IS_ERR(bh)) {
5022 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5023 		return PTR_ERR(bh);
5024 	}
5025 	/*
5026 	 * Note: s_es must be initialized as soon as possible because
5027 	 *       some ext4 macro-instructions depend on its value
5028 	 */
5029 	es = (struct ext4_super_block *) (bh->b_data + offset);
5030 	sbi->s_es = es;
5031 	sb->s_magic = le16_to_cpu(es->s_magic);
5032 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5033 		if (!silent)
5034 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5035 		goto out;
5036 	}
5037 
5038 	if (le32_to_cpu(es->s_log_block_size) >
5039 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5040 		ext4_msg(sb, KERN_ERR,
5041 			 "Invalid log block size: %u",
5042 			 le32_to_cpu(es->s_log_block_size));
5043 		goto out;
5044 	}
5045 	if (le32_to_cpu(es->s_log_cluster_size) >
5046 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5047 		ext4_msg(sb, KERN_ERR,
5048 			 "Invalid log cluster size: %u",
5049 			 le32_to_cpu(es->s_log_cluster_size));
5050 		goto out;
5051 	}
5052 
5053 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5054 
5055 	/*
5056 	 * If the default block size is not the same as the real block size,
5057 	 * we need to reload it.
5058 	 */
5059 	if (sb->s_blocksize == blocksize) {
5060 		*lsb = logical_sb_block;
5061 		sbi->s_sbh = bh;
5062 		return 0;
5063 	}
5064 
5065 	/*
5066 	 * bh must be released before kill_bdev(), otherwise
5067 	 * it won't be freed and its page also. kill_bdev()
5068 	 * is called by sb_set_blocksize().
5069 	 */
5070 	brelse(bh);
5071 	/* Validate the filesystem blocksize */
5072 	if (!sb_set_blocksize(sb, blocksize)) {
5073 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5074 				blocksize);
5075 		bh = NULL;
5076 		goto out;
5077 	}
5078 
5079 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5080 	offset = do_div(logical_sb_block, blocksize);
5081 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5082 	if (IS_ERR(bh)) {
5083 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5084 		ret = PTR_ERR(bh);
5085 		bh = NULL;
5086 		goto out;
5087 	}
5088 	es = (struct ext4_super_block *)(bh->b_data + offset);
5089 	sbi->s_es = es;
5090 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5091 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5092 		goto out;
5093 	}
5094 	*lsb = logical_sb_block;
5095 	sbi->s_sbh = bh;
5096 	return 0;
5097 out:
5098 	brelse(bh);
5099 	return ret;
5100 }
5101 
5102 static void ext4_hash_info_init(struct super_block *sb)
5103 {
5104 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5105 	struct ext4_super_block *es = sbi->s_es;
5106 	unsigned int i;
5107 
5108 	for (i = 0; i < 4; i++)
5109 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5110 
5111 	sbi->s_def_hash_version = es->s_def_hash_version;
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 }
5130 
5131 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5132 {
5133 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5134 	struct ext4_super_block *es = sbi->s_es;
5135 	int has_huge_files;
5136 
5137 	has_huge_files = ext4_has_feature_huge_file(sb);
5138 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5139 						      has_huge_files);
5140 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5141 
5142 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5143 	if (ext4_has_feature_64bit(sb)) {
5144 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5145 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5146 		    !is_power_of_2(sbi->s_desc_size)) {
5147 			ext4_msg(sb, KERN_ERR,
5148 			       "unsupported descriptor size %lu",
5149 			       sbi->s_desc_size);
5150 			return -EINVAL;
5151 		}
5152 	} else
5153 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5154 
5155 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5156 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5157 
5158 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5159 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5160 		if (!silent)
5161 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5162 		return -EINVAL;
5163 	}
5164 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5165 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5166 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5167 			 sbi->s_inodes_per_group);
5168 		return -EINVAL;
5169 	}
5170 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5171 					sbi->s_inodes_per_block;
5172 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5173 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5174 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5175 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5176 
5177 	return 0;
5178 }
5179 
5180 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5181 {
5182 	struct ext4_super_block *es = NULL;
5183 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5184 	ext4_fsblk_t logical_sb_block;
5185 	struct inode *root;
5186 	int needs_recovery;
5187 	int err;
5188 	ext4_group_t first_not_zeroed;
5189 	struct ext4_fs_context *ctx = fc->fs_private;
5190 	int silent = fc->sb_flags & SB_SILENT;
5191 
5192 	/* Set defaults for the variables that will be set during parsing */
5193 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5194 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5195 
5196 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5197 	sbi->s_sectors_written_start =
5198 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5199 
5200 	err = ext4_load_super(sb, &logical_sb_block, silent);
5201 	if (err)
5202 		goto out_fail;
5203 
5204 	es = sbi->s_es;
5205 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5206 
5207 	err = ext4_init_metadata_csum(sb, es);
5208 	if (err)
5209 		goto failed_mount;
5210 
5211 	ext4_set_def_opts(sb, es);
5212 
5213 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5214 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5215 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5216 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5217 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5218 
5219 	/*
5220 	 * set default s_li_wait_mult for lazyinit, for the case there is
5221 	 * no mount option specified.
5222 	 */
5223 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5224 
5225 	err = ext4_inode_info_init(sb, es);
5226 	if (err)
5227 		goto failed_mount;
5228 
5229 	err = parse_apply_sb_mount_options(sb, ctx);
5230 	if (err < 0)
5231 		goto failed_mount;
5232 
5233 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5234 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5235 
5236 	err = ext4_check_opt_consistency(fc, sb);
5237 	if (err < 0)
5238 		goto failed_mount;
5239 
5240 	ext4_apply_options(fc, sb);
5241 
5242 	err = ext4_encoding_init(sb, es);
5243 	if (err)
5244 		goto failed_mount;
5245 
5246 	err = ext4_check_journal_data_mode(sb);
5247 	if (err)
5248 		goto failed_mount;
5249 
5250 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5251 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5252 
5253 	/* i_version is always enabled now */
5254 	sb->s_flags |= SB_I_VERSION;
5255 
5256 	err = ext4_check_feature_compatibility(sb, es, silent);
5257 	if (err)
5258 		goto failed_mount;
5259 
5260 	err = ext4_block_group_meta_init(sb, silent);
5261 	if (err)
5262 		goto failed_mount;
5263 
5264 	ext4_hash_info_init(sb);
5265 
5266 	err = ext4_handle_clustersize(sb);
5267 	if (err)
5268 		goto failed_mount;
5269 
5270 	err = ext4_check_geometry(sb, es);
5271 	if (err)
5272 		goto failed_mount;
5273 
5274 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5275 	spin_lock_init(&sbi->s_error_lock);
5276 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5277 
5278 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5279 	if (err)
5280 		goto failed_mount3;
5281 
5282 	err = ext4_es_register_shrinker(sbi);
5283 	if (err)
5284 		goto failed_mount3;
5285 
5286 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5287 	/*
5288 	 * It's hard to get stripe aligned blocks if stripe is not aligned with
5289 	 * cluster, just disable stripe and alert user to simpfy code and avoid
5290 	 * stripe aligned allocation which will rarely successes.
5291 	 */
5292 	if (sbi->s_stripe > 0 && sbi->s_cluster_ratio > 1 &&
5293 	    sbi->s_stripe % sbi->s_cluster_ratio != 0) {
5294 		ext4_msg(sb, KERN_WARNING,
5295 			 "stripe (%lu) is not aligned with cluster size (%u), "
5296 			 "stripe is disabled",
5297 			 sbi->s_stripe, sbi->s_cluster_ratio);
5298 		sbi->s_stripe = 0;
5299 	}
5300 	sbi->s_extent_max_zeroout_kb = 32;
5301 
5302 	/*
5303 	 * set up enough so that it can read an inode
5304 	 */
5305 	sb->s_op = &ext4_sops;
5306 	sb->s_export_op = &ext4_export_ops;
5307 	sb->s_xattr = ext4_xattr_handlers;
5308 #ifdef CONFIG_FS_ENCRYPTION
5309 	sb->s_cop = &ext4_cryptops;
5310 #endif
5311 #ifdef CONFIG_FS_VERITY
5312 	sb->s_vop = &ext4_verityops;
5313 #endif
5314 #ifdef CONFIG_QUOTA
5315 	sb->dq_op = &ext4_quota_operations;
5316 	if (ext4_has_feature_quota(sb))
5317 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5318 	else
5319 		sb->s_qcop = &ext4_qctl_operations;
5320 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5321 #endif
5322 	super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));
5323 	super_set_sysfs_name_bdev(sb);
5324 
5325 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5326 	mutex_init(&sbi->s_orphan_lock);
5327 
5328 	ext4_fast_commit_init(sb);
5329 
5330 	sb->s_root = NULL;
5331 
5332 	needs_recovery = (es->s_last_orphan != 0 ||
5333 			  ext4_has_feature_orphan_present(sb) ||
5334 			  ext4_has_feature_journal_needs_recovery(sb));
5335 
5336 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5337 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5338 		if (err)
5339 			goto failed_mount3a;
5340 	}
5341 
5342 	err = -EINVAL;
5343 	/*
5344 	 * The first inode we look at is the journal inode.  Don't try
5345 	 * root first: it may be modified in the journal!
5346 	 */
5347 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5348 		err = ext4_load_and_init_journal(sb, es, ctx);
5349 		if (err)
5350 			goto failed_mount3a;
5351 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5352 		   ext4_has_feature_journal_needs_recovery(sb)) {
5353 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5354 		       "suppressed and not mounted read-only");
5355 		goto failed_mount3a;
5356 	} else {
5357 		/* Nojournal mode, all journal mount options are illegal */
5358 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5359 			ext4_msg(sb, KERN_ERR, "can't mount with "
5360 				 "journal_async_commit, fs mounted w/o journal");
5361 			goto failed_mount3a;
5362 		}
5363 
5364 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5365 			ext4_msg(sb, KERN_ERR, "can't mount with "
5366 				 "journal_checksum, fs mounted w/o journal");
5367 			goto failed_mount3a;
5368 		}
5369 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5370 			ext4_msg(sb, KERN_ERR, "can't mount with "
5371 				 "commit=%lu, fs mounted w/o journal",
5372 				 sbi->s_commit_interval / HZ);
5373 			goto failed_mount3a;
5374 		}
5375 		if (EXT4_MOUNT_DATA_FLAGS &
5376 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5377 			ext4_msg(sb, KERN_ERR, "can't mount with "
5378 				 "data=, fs mounted w/o journal");
5379 			goto failed_mount3a;
5380 		}
5381 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5382 		clear_opt(sb, JOURNAL_CHECKSUM);
5383 		clear_opt(sb, DATA_FLAGS);
5384 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5385 		sbi->s_journal = NULL;
5386 		needs_recovery = 0;
5387 	}
5388 
5389 	if (!test_opt(sb, NO_MBCACHE)) {
5390 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5391 		if (!sbi->s_ea_block_cache) {
5392 			ext4_msg(sb, KERN_ERR,
5393 				 "Failed to create ea_block_cache");
5394 			err = -EINVAL;
5395 			goto failed_mount_wq;
5396 		}
5397 
5398 		if (ext4_has_feature_ea_inode(sb)) {
5399 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5400 			if (!sbi->s_ea_inode_cache) {
5401 				ext4_msg(sb, KERN_ERR,
5402 					 "Failed to create ea_inode_cache");
5403 				err = -EINVAL;
5404 				goto failed_mount_wq;
5405 			}
5406 		}
5407 	}
5408 
5409 	/*
5410 	 * Get the # of file system overhead blocks from the
5411 	 * superblock if present.
5412 	 */
5413 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5414 	/* ignore the precalculated value if it is ridiculous */
5415 	if (sbi->s_overhead > ext4_blocks_count(es))
5416 		sbi->s_overhead = 0;
5417 	/*
5418 	 * If the bigalloc feature is not enabled recalculating the
5419 	 * overhead doesn't take long, so we might as well just redo
5420 	 * it to make sure we are using the correct value.
5421 	 */
5422 	if (!ext4_has_feature_bigalloc(sb))
5423 		sbi->s_overhead = 0;
5424 	if (sbi->s_overhead == 0) {
5425 		err = ext4_calculate_overhead(sb);
5426 		if (err)
5427 			goto failed_mount_wq;
5428 	}
5429 
5430 	/*
5431 	 * The maximum number of concurrent works can be high and
5432 	 * concurrency isn't really necessary.  Limit it to 1.
5433 	 */
5434 	EXT4_SB(sb)->rsv_conversion_wq =
5435 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5436 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5437 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5438 		err = -ENOMEM;
5439 		goto failed_mount4;
5440 	}
5441 
5442 	/*
5443 	 * The jbd2_journal_load will have done any necessary log recovery,
5444 	 * so we can safely mount the rest of the filesystem now.
5445 	 */
5446 
5447 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5448 	if (IS_ERR(root)) {
5449 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5450 		err = PTR_ERR(root);
5451 		root = NULL;
5452 		goto failed_mount4;
5453 	}
5454 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5455 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5456 		iput(root);
5457 		err = -EFSCORRUPTED;
5458 		goto failed_mount4;
5459 	}
5460 
5461 	generic_set_sb_d_ops(sb);
5462 	sb->s_root = d_make_root(root);
5463 	if (!sb->s_root) {
5464 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5465 		err = -ENOMEM;
5466 		goto failed_mount4;
5467 	}
5468 
5469 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5470 	if (err == -EROFS) {
5471 		sb->s_flags |= SB_RDONLY;
5472 	} else if (err)
5473 		goto failed_mount4a;
5474 
5475 	ext4_set_resv_clusters(sb);
5476 
5477 	if (test_opt(sb, BLOCK_VALIDITY)) {
5478 		err = ext4_setup_system_zone(sb);
5479 		if (err) {
5480 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5481 				 "zone (%d)", err);
5482 			goto failed_mount4a;
5483 		}
5484 	}
5485 	ext4_fc_replay_cleanup(sb);
5486 
5487 	ext4_ext_init(sb);
5488 
5489 	/*
5490 	 * Enable optimize_scan if number of groups is > threshold. This can be
5491 	 * turned off by passing "mb_optimize_scan=0". This can also be
5492 	 * turned on forcefully by passing "mb_optimize_scan=1".
5493 	 */
5494 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5495 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5496 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5497 		else
5498 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5499 	}
5500 
5501 	err = ext4_mb_init(sb);
5502 	if (err) {
5503 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5504 			 err);
5505 		goto failed_mount5;
5506 	}
5507 
5508 	/*
5509 	 * We can only set up the journal commit callback once
5510 	 * mballoc is initialized
5511 	 */
5512 	if (sbi->s_journal)
5513 		sbi->s_journal->j_commit_callback =
5514 			ext4_journal_commit_callback;
5515 
5516 	err = ext4_percpu_param_init(sbi);
5517 	if (err)
5518 		goto failed_mount6;
5519 
5520 	if (ext4_has_feature_flex_bg(sb))
5521 		if (!ext4_fill_flex_info(sb)) {
5522 			ext4_msg(sb, KERN_ERR,
5523 			       "unable to initialize "
5524 			       "flex_bg meta info!");
5525 			err = -ENOMEM;
5526 			goto failed_mount6;
5527 		}
5528 
5529 	err = ext4_register_li_request(sb, first_not_zeroed);
5530 	if (err)
5531 		goto failed_mount6;
5532 
5533 	err = ext4_init_orphan_info(sb);
5534 	if (err)
5535 		goto failed_mount7;
5536 #ifdef CONFIG_QUOTA
5537 	/* Enable quota usage during mount. */
5538 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5539 		err = ext4_enable_quotas(sb);
5540 		if (err)
5541 			goto failed_mount8;
5542 	}
5543 #endif  /* CONFIG_QUOTA */
5544 
5545 	/*
5546 	 * Save the original bdev mapping's wb_err value which could be
5547 	 * used to detect the metadata async write error.
5548 	 */
5549 	spin_lock_init(&sbi->s_bdev_wb_lock);
5550 	errseq_check_and_advance(&sb->s_bdev->bd_mapping->wb_err,
5551 				 &sbi->s_bdev_wb_err);
5552 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5553 	ext4_orphan_cleanup(sb, es);
5554 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5555 	/*
5556 	 * Update the checksum after updating free space/inode counters and
5557 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5558 	 * checksum in the buffer cache until it is written out and
5559 	 * e2fsprogs programs trying to open a file system immediately
5560 	 * after it is mounted can fail.
5561 	 */
5562 	ext4_superblock_csum_set(sb);
5563 	if (needs_recovery) {
5564 		ext4_msg(sb, KERN_INFO, "recovery complete");
5565 		err = ext4_mark_recovery_complete(sb, es);
5566 		if (err)
5567 			goto failed_mount9;
5568 	}
5569 
5570 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5571 		ext4_msg(sb, KERN_WARNING,
5572 			 "mounting with \"discard\" option, but the device does not support discard");
5573 
5574 	if (es->s_error_count)
5575 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5576 
5577 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5578 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5579 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5580 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5581 	atomic_set(&sbi->s_warning_count, 0);
5582 	atomic_set(&sbi->s_msg_count, 0);
5583 
5584 	/* Register sysfs after all initializations are complete. */
5585 	err = ext4_register_sysfs(sb);
5586 	if (err)
5587 		goto failed_mount9;
5588 
5589 	return 0;
5590 
5591 failed_mount9:
5592 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5593 failed_mount8: __maybe_unused
5594 	ext4_release_orphan_info(sb);
5595 failed_mount7:
5596 	ext4_unregister_li_request(sb);
5597 failed_mount6:
5598 	ext4_mb_release(sb);
5599 	ext4_flex_groups_free(sbi);
5600 	ext4_percpu_param_destroy(sbi);
5601 failed_mount5:
5602 	ext4_ext_release(sb);
5603 	ext4_release_system_zone(sb);
5604 failed_mount4a:
5605 	dput(sb->s_root);
5606 	sb->s_root = NULL;
5607 failed_mount4:
5608 	ext4_msg(sb, KERN_ERR, "mount failed");
5609 	if (EXT4_SB(sb)->rsv_conversion_wq)
5610 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5611 failed_mount_wq:
5612 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5613 	sbi->s_ea_inode_cache = NULL;
5614 
5615 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5616 	sbi->s_ea_block_cache = NULL;
5617 
5618 	if (sbi->s_journal) {
5619 		/* flush s_sb_upd_work before journal destroy. */
5620 		flush_work(&sbi->s_sb_upd_work);
5621 		jbd2_journal_destroy(sbi->s_journal);
5622 		sbi->s_journal = NULL;
5623 	}
5624 failed_mount3a:
5625 	ext4_es_unregister_shrinker(sbi);
5626 failed_mount3:
5627 	/* flush s_sb_upd_work before sbi destroy */
5628 	flush_work(&sbi->s_sb_upd_work);
5629 	del_timer_sync(&sbi->s_err_report);
5630 	ext4_stop_mmpd(sbi);
5631 	ext4_group_desc_free(sbi);
5632 failed_mount:
5633 	if (sbi->s_chksum_driver)
5634 		crypto_free_shash(sbi->s_chksum_driver);
5635 
5636 #if IS_ENABLED(CONFIG_UNICODE)
5637 	utf8_unload(sb->s_encoding);
5638 #endif
5639 
5640 #ifdef CONFIG_QUOTA
5641 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5642 		kfree(get_qf_name(sb, sbi, i));
5643 #endif
5644 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5645 	brelse(sbi->s_sbh);
5646 	if (sbi->s_journal_bdev_file) {
5647 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
5648 		bdev_fput(sbi->s_journal_bdev_file);
5649 	}
5650 out_fail:
5651 	invalidate_bdev(sb->s_bdev);
5652 	sb->s_fs_info = NULL;
5653 	return err;
5654 }
5655 
5656 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5657 {
5658 	struct ext4_fs_context *ctx = fc->fs_private;
5659 	struct ext4_sb_info *sbi;
5660 	const char *descr;
5661 	int ret;
5662 
5663 	sbi = ext4_alloc_sbi(sb);
5664 	if (!sbi)
5665 		return -ENOMEM;
5666 
5667 	fc->s_fs_info = sbi;
5668 
5669 	/* Cleanup superblock name */
5670 	strreplace(sb->s_id, '/', '!');
5671 
5672 	sbi->s_sb_block = 1;	/* Default super block location */
5673 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5674 		sbi->s_sb_block = ctx->s_sb_block;
5675 
5676 	ret = __ext4_fill_super(fc, sb);
5677 	if (ret < 0)
5678 		goto free_sbi;
5679 
5680 	if (sbi->s_journal) {
5681 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5682 			descr = " journalled data mode";
5683 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5684 			descr = " ordered data mode";
5685 		else
5686 			descr = " writeback data mode";
5687 	} else
5688 		descr = "out journal";
5689 
5690 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5691 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5692 			 "Quota mode: %s.", &sb->s_uuid,
5693 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5694 			 ext4_quota_mode(sb));
5695 
5696 	/* Update the s_overhead_clusters if necessary */
5697 	ext4_update_overhead(sb, false);
5698 	return 0;
5699 
5700 free_sbi:
5701 	ext4_free_sbi(sbi);
5702 	fc->s_fs_info = NULL;
5703 	return ret;
5704 }
5705 
5706 static int ext4_get_tree(struct fs_context *fc)
5707 {
5708 	return get_tree_bdev(fc, ext4_fill_super);
5709 }
5710 
5711 /*
5712  * Setup any per-fs journal parameters now.  We'll do this both on
5713  * initial mount, once the journal has been initialised but before we've
5714  * done any recovery; and again on any subsequent remount.
5715  */
5716 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5717 {
5718 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5719 
5720 	journal->j_commit_interval = sbi->s_commit_interval;
5721 	journal->j_min_batch_time = sbi->s_min_batch_time;
5722 	journal->j_max_batch_time = sbi->s_max_batch_time;
5723 	ext4_fc_init(sb, journal);
5724 
5725 	write_lock(&journal->j_state_lock);
5726 	if (test_opt(sb, BARRIER))
5727 		journal->j_flags |= JBD2_BARRIER;
5728 	else
5729 		journal->j_flags &= ~JBD2_BARRIER;
5730 	if (test_opt(sb, DATA_ERR_ABORT))
5731 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5732 	else
5733 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5734 	/*
5735 	 * Always enable journal cycle record option, letting the journal
5736 	 * records log transactions continuously between each mount.
5737 	 */
5738 	journal->j_flags |= JBD2_CYCLE_RECORD;
5739 	write_unlock(&journal->j_state_lock);
5740 }
5741 
5742 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5743 					     unsigned int journal_inum)
5744 {
5745 	struct inode *journal_inode;
5746 
5747 	/*
5748 	 * Test for the existence of a valid inode on disk.  Bad things
5749 	 * happen if we iget() an unused inode, as the subsequent iput()
5750 	 * will try to delete it.
5751 	 */
5752 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5753 	if (IS_ERR(journal_inode)) {
5754 		ext4_msg(sb, KERN_ERR, "no journal found");
5755 		return ERR_CAST(journal_inode);
5756 	}
5757 	if (!journal_inode->i_nlink) {
5758 		make_bad_inode(journal_inode);
5759 		iput(journal_inode);
5760 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5761 		return ERR_PTR(-EFSCORRUPTED);
5762 	}
5763 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5764 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5765 		iput(journal_inode);
5766 		return ERR_PTR(-EFSCORRUPTED);
5767 	}
5768 
5769 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5770 		  journal_inode, journal_inode->i_size);
5771 	return journal_inode;
5772 }
5773 
5774 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5775 {
5776 	struct ext4_map_blocks map;
5777 	int ret;
5778 
5779 	if (journal->j_inode == NULL)
5780 		return 0;
5781 
5782 	map.m_lblk = *block;
5783 	map.m_len = 1;
5784 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5785 	if (ret <= 0) {
5786 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5787 			 "journal bmap failed: block %llu ret %d\n",
5788 			 *block, ret);
5789 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5790 		return ret;
5791 	}
5792 	*block = map.m_pblk;
5793 	return 0;
5794 }
5795 
5796 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5797 					  unsigned int journal_inum)
5798 {
5799 	struct inode *journal_inode;
5800 	journal_t *journal;
5801 
5802 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5803 	if (IS_ERR(journal_inode))
5804 		return ERR_CAST(journal_inode);
5805 
5806 	journal = jbd2_journal_init_inode(journal_inode);
5807 	if (IS_ERR(journal)) {
5808 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5809 		iput(journal_inode);
5810 		return ERR_CAST(journal);
5811 	}
5812 	journal->j_private = sb;
5813 	journal->j_bmap = ext4_journal_bmap;
5814 	ext4_init_journal_params(sb, journal);
5815 	return journal;
5816 }
5817 
5818 static struct file *ext4_get_journal_blkdev(struct super_block *sb,
5819 					dev_t j_dev, ext4_fsblk_t *j_start,
5820 					ext4_fsblk_t *j_len)
5821 {
5822 	struct buffer_head *bh;
5823 	struct block_device *bdev;
5824 	struct file *bdev_file;
5825 	int hblock, blocksize;
5826 	ext4_fsblk_t sb_block;
5827 	unsigned long offset;
5828 	struct ext4_super_block *es;
5829 	int errno;
5830 
5831 	bdev_file = bdev_file_open_by_dev(j_dev,
5832 		BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
5833 		sb, &fs_holder_ops);
5834 	if (IS_ERR(bdev_file)) {
5835 		ext4_msg(sb, KERN_ERR,
5836 			 "failed to open journal device unknown-block(%u,%u) %ld",
5837 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev_file));
5838 		return bdev_file;
5839 	}
5840 
5841 	bdev = file_bdev(bdev_file);
5842 	blocksize = sb->s_blocksize;
5843 	hblock = bdev_logical_block_size(bdev);
5844 	if (blocksize < hblock) {
5845 		ext4_msg(sb, KERN_ERR,
5846 			"blocksize too small for journal device");
5847 		errno = -EINVAL;
5848 		goto out_bdev;
5849 	}
5850 
5851 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5852 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5853 	set_blocksize(bdev_file, blocksize);
5854 	bh = __bread(bdev, sb_block, blocksize);
5855 	if (!bh) {
5856 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5857 		       "external journal");
5858 		errno = -EINVAL;
5859 		goto out_bdev;
5860 	}
5861 
5862 	es = (struct ext4_super_block *) (bh->b_data + offset);
5863 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5864 	    !(le32_to_cpu(es->s_feature_incompat) &
5865 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5866 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
5867 		errno = -EFSCORRUPTED;
5868 		goto out_bh;
5869 	}
5870 
5871 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5872 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5873 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5874 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
5875 		errno = -EFSCORRUPTED;
5876 		goto out_bh;
5877 	}
5878 
5879 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5880 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5881 		errno = -EFSCORRUPTED;
5882 		goto out_bh;
5883 	}
5884 
5885 	*j_start = sb_block + 1;
5886 	*j_len = ext4_blocks_count(es);
5887 	brelse(bh);
5888 	return bdev_file;
5889 
5890 out_bh:
5891 	brelse(bh);
5892 out_bdev:
5893 	bdev_fput(bdev_file);
5894 	return ERR_PTR(errno);
5895 }
5896 
5897 static journal_t *ext4_open_dev_journal(struct super_block *sb,
5898 					dev_t j_dev)
5899 {
5900 	journal_t *journal;
5901 	ext4_fsblk_t j_start;
5902 	ext4_fsblk_t j_len;
5903 	struct file *bdev_file;
5904 	int errno = 0;
5905 
5906 	bdev_file = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
5907 	if (IS_ERR(bdev_file))
5908 		return ERR_CAST(bdev_file);
5909 
5910 	journal = jbd2_journal_init_dev(file_bdev(bdev_file), sb->s_bdev, j_start,
5911 					j_len, sb->s_blocksize);
5912 	if (IS_ERR(journal)) {
5913 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5914 		errno = PTR_ERR(journal);
5915 		goto out_bdev;
5916 	}
5917 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5918 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5919 					"user (unsupported) - %d",
5920 			be32_to_cpu(journal->j_superblock->s_nr_users));
5921 		errno = -EINVAL;
5922 		goto out_journal;
5923 	}
5924 	journal->j_private = sb;
5925 	EXT4_SB(sb)->s_journal_bdev_file = bdev_file;
5926 	ext4_init_journal_params(sb, journal);
5927 	return journal;
5928 
5929 out_journal:
5930 	jbd2_journal_destroy(journal);
5931 out_bdev:
5932 	bdev_fput(bdev_file);
5933 	return ERR_PTR(errno);
5934 }
5935 
5936 static int ext4_load_journal(struct super_block *sb,
5937 			     struct ext4_super_block *es,
5938 			     unsigned long journal_devnum)
5939 {
5940 	journal_t *journal;
5941 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5942 	dev_t journal_dev;
5943 	int err = 0;
5944 	int really_read_only;
5945 	int journal_dev_ro;
5946 
5947 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5948 		return -EFSCORRUPTED;
5949 
5950 	if (journal_devnum &&
5951 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5952 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5953 			"numbers have changed");
5954 		journal_dev = new_decode_dev(journal_devnum);
5955 	} else
5956 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5957 
5958 	if (journal_inum && journal_dev) {
5959 		ext4_msg(sb, KERN_ERR,
5960 			 "filesystem has both journal inode and journal device!");
5961 		return -EINVAL;
5962 	}
5963 
5964 	if (journal_inum) {
5965 		journal = ext4_open_inode_journal(sb, journal_inum);
5966 		if (IS_ERR(journal))
5967 			return PTR_ERR(journal);
5968 	} else {
5969 		journal = ext4_open_dev_journal(sb, journal_dev);
5970 		if (IS_ERR(journal))
5971 			return PTR_ERR(journal);
5972 	}
5973 
5974 	journal_dev_ro = bdev_read_only(journal->j_dev);
5975 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5976 
5977 	if (journal_dev_ro && !sb_rdonly(sb)) {
5978 		ext4_msg(sb, KERN_ERR,
5979 			 "journal device read-only, try mounting with '-o ro'");
5980 		err = -EROFS;
5981 		goto err_out;
5982 	}
5983 
5984 	/*
5985 	 * Are we loading a blank journal or performing recovery after a
5986 	 * crash?  For recovery, we need to check in advance whether we
5987 	 * can get read-write access to the device.
5988 	 */
5989 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5990 		if (sb_rdonly(sb)) {
5991 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5992 					"required on readonly filesystem");
5993 			if (really_read_only) {
5994 				ext4_msg(sb, KERN_ERR, "write access "
5995 					"unavailable, cannot proceed "
5996 					"(try mounting with noload)");
5997 				err = -EROFS;
5998 				goto err_out;
5999 			}
6000 			ext4_msg(sb, KERN_INFO, "write access will "
6001 			       "be enabled during recovery");
6002 		}
6003 	}
6004 
6005 	if (!(journal->j_flags & JBD2_BARRIER))
6006 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6007 
6008 	if (!ext4_has_feature_journal_needs_recovery(sb))
6009 		err = jbd2_journal_wipe(journal, !really_read_only);
6010 	if (!err) {
6011 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6012 		__le16 orig_state;
6013 		bool changed = false;
6014 
6015 		if (save)
6016 			memcpy(save, ((char *) es) +
6017 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6018 		err = jbd2_journal_load(journal);
6019 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6020 				   save, EXT4_S_ERR_LEN)) {
6021 			memcpy(((char *) es) + EXT4_S_ERR_START,
6022 			       save, EXT4_S_ERR_LEN);
6023 			changed = true;
6024 		}
6025 		kfree(save);
6026 		orig_state = es->s_state;
6027 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6028 					   EXT4_ERROR_FS);
6029 		if (orig_state != es->s_state)
6030 			changed = true;
6031 		/* Write out restored error information to the superblock */
6032 		if (changed && !really_read_only) {
6033 			int err2;
6034 			err2 = ext4_commit_super(sb);
6035 			err = err ? : err2;
6036 		}
6037 	}
6038 
6039 	if (err) {
6040 		ext4_msg(sb, KERN_ERR, "error loading journal");
6041 		goto err_out;
6042 	}
6043 
6044 	EXT4_SB(sb)->s_journal = journal;
6045 	err = ext4_clear_journal_err(sb, es);
6046 	if (err) {
6047 		EXT4_SB(sb)->s_journal = NULL;
6048 		jbd2_journal_destroy(journal);
6049 		return err;
6050 	}
6051 
6052 	if (!really_read_only && journal_devnum &&
6053 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6054 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6055 		ext4_commit_super(sb);
6056 	}
6057 	if (!really_read_only && journal_inum &&
6058 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6059 		es->s_journal_inum = cpu_to_le32(journal_inum);
6060 		ext4_commit_super(sb);
6061 	}
6062 
6063 	return 0;
6064 
6065 err_out:
6066 	jbd2_journal_destroy(journal);
6067 	return err;
6068 }
6069 
6070 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6071 static void ext4_update_super(struct super_block *sb)
6072 {
6073 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6074 	struct ext4_super_block *es = sbi->s_es;
6075 	struct buffer_head *sbh = sbi->s_sbh;
6076 
6077 	lock_buffer(sbh);
6078 	/*
6079 	 * If the file system is mounted read-only, don't update the
6080 	 * superblock write time.  This avoids updating the superblock
6081 	 * write time when we are mounting the root file system
6082 	 * read/only but we need to replay the journal; at that point,
6083 	 * for people who are east of GMT and who make their clock
6084 	 * tick in localtime for Windows bug-for-bug compatibility,
6085 	 * the clock is set in the future, and this will cause e2fsck
6086 	 * to complain and force a full file system check.
6087 	 */
6088 	if (!sb_rdonly(sb))
6089 		ext4_update_tstamp(es, s_wtime);
6090 	es->s_kbytes_written =
6091 		cpu_to_le64(sbi->s_kbytes_written +
6092 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6093 		      sbi->s_sectors_written_start) >> 1));
6094 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6095 		ext4_free_blocks_count_set(es,
6096 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6097 				&sbi->s_freeclusters_counter)));
6098 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6099 		es->s_free_inodes_count =
6100 			cpu_to_le32(percpu_counter_sum_positive(
6101 				&sbi->s_freeinodes_counter));
6102 	/* Copy error information to the on-disk superblock */
6103 	spin_lock(&sbi->s_error_lock);
6104 	if (sbi->s_add_error_count > 0) {
6105 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6106 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6107 			__ext4_update_tstamp(&es->s_first_error_time,
6108 					     &es->s_first_error_time_hi,
6109 					     sbi->s_first_error_time);
6110 			strtomem_pad(es->s_first_error_func,
6111 				     sbi->s_first_error_func, 0);
6112 			es->s_first_error_line =
6113 				cpu_to_le32(sbi->s_first_error_line);
6114 			es->s_first_error_ino =
6115 				cpu_to_le32(sbi->s_first_error_ino);
6116 			es->s_first_error_block =
6117 				cpu_to_le64(sbi->s_first_error_block);
6118 			es->s_first_error_errcode =
6119 				ext4_errno_to_code(sbi->s_first_error_code);
6120 		}
6121 		__ext4_update_tstamp(&es->s_last_error_time,
6122 				     &es->s_last_error_time_hi,
6123 				     sbi->s_last_error_time);
6124 		strtomem_pad(es->s_last_error_func, sbi->s_last_error_func, 0);
6125 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6126 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6127 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6128 		es->s_last_error_errcode =
6129 				ext4_errno_to_code(sbi->s_last_error_code);
6130 		/*
6131 		 * Start the daily error reporting function if it hasn't been
6132 		 * started already
6133 		 */
6134 		if (!es->s_error_count)
6135 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6136 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6137 		sbi->s_add_error_count = 0;
6138 	}
6139 	spin_unlock(&sbi->s_error_lock);
6140 
6141 	ext4_superblock_csum_set(sb);
6142 	unlock_buffer(sbh);
6143 }
6144 
6145 static int ext4_commit_super(struct super_block *sb)
6146 {
6147 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6148 
6149 	if (!sbh)
6150 		return -EINVAL;
6151 
6152 	ext4_update_super(sb);
6153 
6154 	lock_buffer(sbh);
6155 	/* Buffer got discarded which means block device got invalidated */
6156 	if (!buffer_mapped(sbh)) {
6157 		unlock_buffer(sbh);
6158 		return -EIO;
6159 	}
6160 
6161 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6162 		/*
6163 		 * Oh, dear.  A previous attempt to write the
6164 		 * superblock failed.  This could happen because the
6165 		 * USB device was yanked out.  Or it could happen to
6166 		 * be a transient write error and maybe the block will
6167 		 * be remapped.  Nothing we can do but to retry the
6168 		 * write and hope for the best.
6169 		 */
6170 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6171 		       "superblock detected");
6172 		clear_buffer_write_io_error(sbh);
6173 		set_buffer_uptodate(sbh);
6174 	}
6175 	get_bh(sbh);
6176 	/* Clear potential dirty bit if it was journalled update */
6177 	clear_buffer_dirty(sbh);
6178 	sbh->b_end_io = end_buffer_write_sync;
6179 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6180 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6181 	wait_on_buffer(sbh);
6182 	if (buffer_write_io_error(sbh)) {
6183 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6184 		       "superblock");
6185 		clear_buffer_write_io_error(sbh);
6186 		set_buffer_uptodate(sbh);
6187 		return -EIO;
6188 	}
6189 	return 0;
6190 }
6191 
6192 /*
6193  * Have we just finished recovery?  If so, and if we are mounting (or
6194  * remounting) the filesystem readonly, then we will end up with a
6195  * consistent fs on disk.  Record that fact.
6196  */
6197 static int ext4_mark_recovery_complete(struct super_block *sb,
6198 				       struct ext4_super_block *es)
6199 {
6200 	int err;
6201 	journal_t *journal = EXT4_SB(sb)->s_journal;
6202 
6203 	if (!ext4_has_feature_journal(sb)) {
6204 		if (journal != NULL) {
6205 			ext4_error(sb, "Journal got removed while the fs was "
6206 				   "mounted!");
6207 			return -EFSCORRUPTED;
6208 		}
6209 		return 0;
6210 	}
6211 	jbd2_journal_lock_updates(journal);
6212 	err = jbd2_journal_flush(journal, 0);
6213 	if (err < 0)
6214 		goto out;
6215 
6216 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6217 	    ext4_has_feature_orphan_present(sb))) {
6218 		if (!ext4_orphan_file_empty(sb)) {
6219 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6220 			err = -EFSCORRUPTED;
6221 			goto out;
6222 		}
6223 		ext4_clear_feature_journal_needs_recovery(sb);
6224 		ext4_clear_feature_orphan_present(sb);
6225 		ext4_commit_super(sb);
6226 	}
6227 out:
6228 	jbd2_journal_unlock_updates(journal);
6229 	return err;
6230 }
6231 
6232 /*
6233  * If we are mounting (or read-write remounting) a filesystem whose journal
6234  * has recorded an error from a previous lifetime, move that error to the
6235  * main filesystem now.
6236  */
6237 static int ext4_clear_journal_err(struct super_block *sb,
6238 				   struct ext4_super_block *es)
6239 {
6240 	journal_t *journal;
6241 	int j_errno;
6242 	const char *errstr;
6243 
6244 	if (!ext4_has_feature_journal(sb)) {
6245 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6246 		return -EFSCORRUPTED;
6247 	}
6248 
6249 	journal = EXT4_SB(sb)->s_journal;
6250 
6251 	/*
6252 	 * Now check for any error status which may have been recorded in the
6253 	 * journal by a prior ext4_error() or ext4_abort()
6254 	 */
6255 
6256 	j_errno = jbd2_journal_errno(journal);
6257 	if (j_errno) {
6258 		char nbuf[16];
6259 
6260 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6261 		ext4_warning(sb, "Filesystem error recorded "
6262 			     "from previous mount: %s", errstr);
6263 
6264 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6265 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6266 		j_errno = ext4_commit_super(sb);
6267 		if (j_errno)
6268 			return j_errno;
6269 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6270 
6271 		jbd2_journal_clear_err(journal);
6272 		jbd2_journal_update_sb_errno(journal);
6273 	}
6274 	return 0;
6275 }
6276 
6277 /*
6278  * Force the running and committing transactions to commit,
6279  * and wait on the commit.
6280  */
6281 int ext4_force_commit(struct super_block *sb)
6282 {
6283 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6284 }
6285 
6286 static int ext4_sync_fs(struct super_block *sb, int wait)
6287 {
6288 	int ret = 0;
6289 	tid_t target;
6290 	bool needs_barrier = false;
6291 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6292 
6293 	if (unlikely(ext4_forced_shutdown(sb)))
6294 		return 0;
6295 
6296 	trace_ext4_sync_fs(sb, wait);
6297 	flush_workqueue(sbi->rsv_conversion_wq);
6298 	/*
6299 	 * Writeback quota in non-journalled quota case - journalled quota has
6300 	 * no dirty dquots
6301 	 */
6302 	dquot_writeback_dquots(sb, -1);
6303 	/*
6304 	 * Data writeback is possible w/o journal transaction, so barrier must
6305 	 * being sent at the end of the function. But we can skip it if
6306 	 * transaction_commit will do it for us.
6307 	 */
6308 	if (sbi->s_journal) {
6309 		target = jbd2_get_latest_transaction(sbi->s_journal);
6310 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6311 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6312 			needs_barrier = true;
6313 
6314 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6315 			if (wait)
6316 				ret = jbd2_log_wait_commit(sbi->s_journal,
6317 							   target);
6318 		}
6319 	} else if (wait && test_opt(sb, BARRIER))
6320 		needs_barrier = true;
6321 	if (needs_barrier) {
6322 		int err;
6323 		err = blkdev_issue_flush(sb->s_bdev);
6324 		if (!ret)
6325 			ret = err;
6326 	}
6327 
6328 	return ret;
6329 }
6330 
6331 /*
6332  * LVM calls this function before a (read-only) snapshot is created.  This
6333  * gives us a chance to flush the journal completely and mark the fs clean.
6334  *
6335  * Note that only this function cannot bring a filesystem to be in a clean
6336  * state independently. It relies on upper layer to stop all data & metadata
6337  * modifications.
6338  */
6339 static int ext4_freeze(struct super_block *sb)
6340 {
6341 	int error = 0;
6342 	journal_t *journal = EXT4_SB(sb)->s_journal;
6343 
6344 	if (journal) {
6345 		/* Now we set up the journal barrier. */
6346 		jbd2_journal_lock_updates(journal);
6347 
6348 		/*
6349 		 * Don't clear the needs_recovery flag if we failed to
6350 		 * flush the journal.
6351 		 */
6352 		error = jbd2_journal_flush(journal, 0);
6353 		if (error < 0)
6354 			goto out;
6355 
6356 		/* Journal blocked and flushed, clear needs_recovery flag. */
6357 		ext4_clear_feature_journal_needs_recovery(sb);
6358 		if (ext4_orphan_file_empty(sb))
6359 			ext4_clear_feature_orphan_present(sb);
6360 	}
6361 
6362 	error = ext4_commit_super(sb);
6363 out:
6364 	if (journal)
6365 		/* we rely on upper layer to stop further updates */
6366 		jbd2_journal_unlock_updates(journal);
6367 	return error;
6368 }
6369 
6370 /*
6371  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6372  * flag here, even though the filesystem is not technically dirty yet.
6373  */
6374 static int ext4_unfreeze(struct super_block *sb)
6375 {
6376 	if (ext4_forced_shutdown(sb))
6377 		return 0;
6378 
6379 	if (EXT4_SB(sb)->s_journal) {
6380 		/* Reset the needs_recovery flag before the fs is unlocked. */
6381 		ext4_set_feature_journal_needs_recovery(sb);
6382 		if (ext4_has_feature_orphan_file(sb))
6383 			ext4_set_feature_orphan_present(sb);
6384 	}
6385 
6386 	ext4_commit_super(sb);
6387 	return 0;
6388 }
6389 
6390 /*
6391  * Structure to save mount options for ext4_remount's benefit
6392  */
6393 struct ext4_mount_options {
6394 	unsigned long s_mount_opt;
6395 	unsigned long s_mount_opt2;
6396 	kuid_t s_resuid;
6397 	kgid_t s_resgid;
6398 	unsigned long s_commit_interval;
6399 	u32 s_min_batch_time, s_max_batch_time;
6400 #ifdef CONFIG_QUOTA
6401 	int s_jquota_fmt;
6402 	char *s_qf_names[EXT4_MAXQUOTAS];
6403 #endif
6404 };
6405 
6406 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6407 {
6408 	struct ext4_fs_context *ctx = fc->fs_private;
6409 	struct ext4_super_block *es;
6410 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6411 	unsigned long old_sb_flags;
6412 	struct ext4_mount_options old_opts;
6413 	ext4_group_t g;
6414 	int err = 0;
6415 	int alloc_ctx;
6416 #ifdef CONFIG_QUOTA
6417 	int enable_quota = 0;
6418 	int i, j;
6419 	char *to_free[EXT4_MAXQUOTAS];
6420 #endif
6421 
6422 
6423 	/* Store the original options */
6424 	old_sb_flags = sb->s_flags;
6425 	old_opts.s_mount_opt = sbi->s_mount_opt;
6426 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6427 	old_opts.s_resuid = sbi->s_resuid;
6428 	old_opts.s_resgid = sbi->s_resgid;
6429 	old_opts.s_commit_interval = sbi->s_commit_interval;
6430 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6431 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6432 #ifdef CONFIG_QUOTA
6433 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6434 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6435 		if (sbi->s_qf_names[i]) {
6436 			char *qf_name = get_qf_name(sb, sbi, i);
6437 
6438 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6439 			if (!old_opts.s_qf_names[i]) {
6440 				for (j = 0; j < i; j++)
6441 					kfree(old_opts.s_qf_names[j]);
6442 				return -ENOMEM;
6443 			}
6444 		} else
6445 			old_opts.s_qf_names[i] = NULL;
6446 #endif
6447 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6448 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6449 			ctx->journal_ioprio =
6450 				sbi->s_journal->j_task->io_context->ioprio;
6451 		else
6452 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6453 
6454 	}
6455 
6456 	/*
6457 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6458 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6459 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6460 	 * here s_writepages_rwsem to avoid race between writepages ops and
6461 	 * remount.
6462 	 */
6463 	alloc_ctx = ext4_writepages_down_write(sb);
6464 	ext4_apply_options(fc, sb);
6465 	ext4_writepages_up_write(sb, alloc_ctx);
6466 
6467 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6468 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6469 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6470 			 "during remount not supported; ignoring");
6471 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6472 	}
6473 
6474 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6475 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6476 			ext4_msg(sb, KERN_ERR, "can't mount with "
6477 				 "both data=journal and delalloc");
6478 			err = -EINVAL;
6479 			goto restore_opts;
6480 		}
6481 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6482 			ext4_msg(sb, KERN_ERR, "can't mount with "
6483 				 "both data=journal and dioread_nolock");
6484 			err = -EINVAL;
6485 			goto restore_opts;
6486 		}
6487 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6488 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6489 			ext4_msg(sb, KERN_ERR, "can't mount with "
6490 				"journal_async_commit in data=ordered mode");
6491 			err = -EINVAL;
6492 			goto restore_opts;
6493 		}
6494 	}
6495 
6496 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6497 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6498 		err = -EINVAL;
6499 		goto restore_opts;
6500 	}
6501 
6502 	if (test_opt2(sb, ABORT))
6503 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6504 
6505 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6506 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6507 
6508 	es = sbi->s_es;
6509 
6510 	if (sbi->s_journal) {
6511 		ext4_init_journal_params(sb, sbi->s_journal);
6512 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6513 	}
6514 
6515 	/* Flush outstanding errors before changing fs state */
6516 	flush_work(&sbi->s_sb_upd_work);
6517 
6518 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6519 		if (ext4_forced_shutdown(sb)) {
6520 			err = -EROFS;
6521 			goto restore_opts;
6522 		}
6523 
6524 		if (fc->sb_flags & SB_RDONLY) {
6525 			err = sync_filesystem(sb);
6526 			if (err < 0)
6527 				goto restore_opts;
6528 			err = dquot_suspend(sb, -1);
6529 			if (err < 0)
6530 				goto restore_opts;
6531 
6532 			/*
6533 			 * First of all, the unconditional stuff we have to do
6534 			 * to disable replay of the journal when we next remount
6535 			 */
6536 			sb->s_flags |= SB_RDONLY;
6537 
6538 			/*
6539 			 * OK, test if we are remounting a valid rw partition
6540 			 * readonly, and if so set the rdonly flag and then
6541 			 * mark the partition as valid again.
6542 			 */
6543 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6544 			    (sbi->s_mount_state & EXT4_VALID_FS))
6545 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6546 
6547 			if (sbi->s_journal) {
6548 				/*
6549 				 * We let remount-ro finish even if marking fs
6550 				 * as clean failed...
6551 				 */
6552 				ext4_mark_recovery_complete(sb, es);
6553 			}
6554 		} else {
6555 			/* Make sure we can mount this feature set readwrite */
6556 			if (ext4_has_feature_readonly(sb) ||
6557 			    !ext4_feature_set_ok(sb, 0)) {
6558 				err = -EROFS;
6559 				goto restore_opts;
6560 			}
6561 			/*
6562 			 * Make sure the group descriptor checksums
6563 			 * are sane.  If they aren't, refuse to remount r/w.
6564 			 */
6565 			for (g = 0; g < sbi->s_groups_count; g++) {
6566 				struct ext4_group_desc *gdp =
6567 					ext4_get_group_desc(sb, g, NULL);
6568 
6569 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6570 					ext4_msg(sb, KERN_ERR,
6571 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6572 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6573 					       le16_to_cpu(gdp->bg_checksum));
6574 					err = -EFSBADCRC;
6575 					goto restore_opts;
6576 				}
6577 			}
6578 
6579 			/*
6580 			 * If we have an unprocessed orphan list hanging
6581 			 * around from a previously readonly bdev mount,
6582 			 * require a full umount/remount for now.
6583 			 */
6584 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6585 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6586 				       "remount RDWR because of unprocessed "
6587 				       "orphan inode list.  Please "
6588 				       "umount/remount instead");
6589 				err = -EINVAL;
6590 				goto restore_opts;
6591 			}
6592 
6593 			/*
6594 			 * Mounting a RDONLY partition read-write, so reread
6595 			 * and store the current valid flag.  (It may have
6596 			 * been changed by e2fsck since we originally mounted
6597 			 * the partition.)
6598 			 */
6599 			if (sbi->s_journal) {
6600 				err = ext4_clear_journal_err(sb, es);
6601 				if (err)
6602 					goto restore_opts;
6603 			}
6604 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6605 					      ~EXT4_FC_REPLAY);
6606 
6607 			err = ext4_setup_super(sb, es, 0);
6608 			if (err)
6609 				goto restore_opts;
6610 
6611 			sb->s_flags &= ~SB_RDONLY;
6612 			if (ext4_has_feature_mmp(sb)) {
6613 				err = ext4_multi_mount_protect(sb,
6614 						le64_to_cpu(es->s_mmp_block));
6615 				if (err)
6616 					goto restore_opts;
6617 			}
6618 #ifdef CONFIG_QUOTA
6619 			enable_quota = 1;
6620 #endif
6621 		}
6622 	}
6623 
6624 	/*
6625 	 * Handle creation of system zone data early because it can fail.
6626 	 * Releasing of existing data is done when we are sure remount will
6627 	 * succeed.
6628 	 */
6629 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6630 		err = ext4_setup_system_zone(sb);
6631 		if (err)
6632 			goto restore_opts;
6633 	}
6634 
6635 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6636 		err = ext4_commit_super(sb);
6637 		if (err)
6638 			goto restore_opts;
6639 	}
6640 
6641 #ifdef CONFIG_QUOTA
6642 	if (enable_quota) {
6643 		if (sb_any_quota_suspended(sb))
6644 			dquot_resume(sb, -1);
6645 		else if (ext4_has_feature_quota(sb)) {
6646 			err = ext4_enable_quotas(sb);
6647 			if (err)
6648 				goto restore_opts;
6649 		}
6650 	}
6651 	/* Release old quota file names */
6652 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6653 		kfree(old_opts.s_qf_names[i]);
6654 #endif
6655 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6656 		ext4_release_system_zone(sb);
6657 
6658 	/*
6659 	 * Reinitialize lazy itable initialization thread based on
6660 	 * current settings
6661 	 */
6662 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6663 		ext4_unregister_li_request(sb);
6664 	else {
6665 		ext4_group_t first_not_zeroed;
6666 		first_not_zeroed = ext4_has_uninit_itable(sb);
6667 		ext4_register_li_request(sb, first_not_zeroed);
6668 	}
6669 
6670 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6671 		ext4_stop_mmpd(sbi);
6672 
6673 	return 0;
6674 
6675 restore_opts:
6676 	/*
6677 	 * If there was a failing r/w to ro transition, we may need to
6678 	 * re-enable quota
6679 	 */
6680 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6681 	    sb_any_quota_suspended(sb))
6682 		dquot_resume(sb, -1);
6683 
6684 	alloc_ctx = ext4_writepages_down_write(sb);
6685 	sb->s_flags = old_sb_flags;
6686 	sbi->s_mount_opt = old_opts.s_mount_opt;
6687 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6688 	sbi->s_resuid = old_opts.s_resuid;
6689 	sbi->s_resgid = old_opts.s_resgid;
6690 	sbi->s_commit_interval = old_opts.s_commit_interval;
6691 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6692 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6693 	ext4_writepages_up_write(sb, alloc_ctx);
6694 
6695 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6696 		ext4_release_system_zone(sb);
6697 #ifdef CONFIG_QUOTA
6698 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6699 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6700 		to_free[i] = get_qf_name(sb, sbi, i);
6701 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6702 	}
6703 	synchronize_rcu();
6704 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6705 		kfree(to_free[i]);
6706 #endif
6707 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6708 		ext4_stop_mmpd(sbi);
6709 	return err;
6710 }
6711 
6712 static int ext4_reconfigure(struct fs_context *fc)
6713 {
6714 	struct super_block *sb = fc->root->d_sb;
6715 	int ret;
6716 
6717 	fc->s_fs_info = EXT4_SB(sb);
6718 
6719 	ret = ext4_check_opt_consistency(fc, sb);
6720 	if (ret < 0)
6721 		return ret;
6722 
6723 	ret = __ext4_remount(fc, sb);
6724 	if (ret < 0)
6725 		return ret;
6726 
6727 	ext4_msg(sb, KERN_INFO, "re-mounted %pU %s. Quota mode: %s.",
6728 		 &sb->s_uuid, sb_rdonly(sb) ? "ro" : "r/w",
6729 		 ext4_quota_mode(sb));
6730 
6731 	return 0;
6732 }
6733 
6734 #ifdef CONFIG_QUOTA
6735 static int ext4_statfs_project(struct super_block *sb,
6736 			       kprojid_t projid, struct kstatfs *buf)
6737 {
6738 	struct kqid qid;
6739 	struct dquot *dquot;
6740 	u64 limit;
6741 	u64 curblock;
6742 
6743 	qid = make_kqid_projid(projid);
6744 	dquot = dqget(sb, qid);
6745 	if (IS_ERR(dquot))
6746 		return PTR_ERR(dquot);
6747 	spin_lock(&dquot->dq_dqb_lock);
6748 
6749 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6750 			     dquot->dq_dqb.dqb_bhardlimit);
6751 	limit >>= sb->s_blocksize_bits;
6752 
6753 	if (limit && buf->f_blocks > limit) {
6754 		curblock = (dquot->dq_dqb.dqb_curspace +
6755 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6756 		buf->f_blocks = limit;
6757 		buf->f_bfree = buf->f_bavail =
6758 			(buf->f_blocks > curblock) ?
6759 			 (buf->f_blocks - curblock) : 0;
6760 	}
6761 
6762 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6763 			     dquot->dq_dqb.dqb_ihardlimit);
6764 	if (limit && buf->f_files > limit) {
6765 		buf->f_files = limit;
6766 		buf->f_ffree =
6767 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6768 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6769 	}
6770 
6771 	spin_unlock(&dquot->dq_dqb_lock);
6772 	dqput(dquot);
6773 	return 0;
6774 }
6775 #endif
6776 
6777 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6778 {
6779 	struct super_block *sb = dentry->d_sb;
6780 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6781 	struct ext4_super_block *es = sbi->s_es;
6782 	ext4_fsblk_t overhead = 0, resv_blocks;
6783 	s64 bfree;
6784 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6785 
6786 	if (!test_opt(sb, MINIX_DF))
6787 		overhead = sbi->s_overhead;
6788 
6789 	buf->f_type = EXT4_SUPER_MAGIC;
6790 	buf->f_bsize = sb->s_blocksize;
6791 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6792 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6793 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6794 	/* prevent underflow in case that few free space is available */
6795 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6796 	buf->f_bavail = buf->f_bfree -
6797 			(ext4_r_blocks_count(es) + resv_blocks);
6798 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6799 		buf->f_bavail = 0;
6800 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6801 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6802 	buf->f_namelen = EXT4_NAME_LEN;
6803 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6804 
6805 #ifdef CONFIG_QUOTA
6806 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6807 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6808 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6809 #endif
6810 	return 0;
6811 }
6812 
6813 
6814 #ifdef CONFIG_QUOTA
6815 
6816 /*
6817  * Helper functions so that transaction is started before we acquire dqio_sem
6818  * to keep correct lock ordering of transaction > dqio_sem
6819  */
6820 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6821 {
6822 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6823 }
6824 
6825 static int ext4_write_dquot(struct dquot *dquot)
6826 {
6827 	int ret, err;
6828 	handle_t *handle;
6829 	struct inode *inode;
6830 
6831 	inode = dquot_to_inode(dquot);
6832 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6833 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6834 	if (IS_ERR(handle))
6835 		return PTR_ERR(handle);
6836 	ret = dquot_commit(dquot);
6837 	if (ret < 0)
6838 		ext4_error_err(dquot->dq_sb, -ret,
6839 			       "Failed to commit dquot type %d",
6840 			       dquot->dq_id.type);
6841 	err = ext4_journal_stop(handle);
6842 	if (!ret)
6843 		ret = err;
6844 	return ret;
6845 }
6846 
6847 static int ext4_acquire_dquot(struct dquot *dquot)
6848 {
6849 	int ret, err;
6850 	handle_t *handle;
6851 
6852 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6853 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6854 	if (IS_ERR(handle))
6855 		return PTR_ERR(handle);
6856 	ret = dquot_acquire(dquot);
6857 	if (ret < 0)
6858 		ext4_error_err(dquot->dq_sb, -ret,
6859 			      "Failed to acquire dquot type %d",
6860 			      dquot->dq_id.type);
6861 	err = ext4_journal_stop(handle);
6862 	if (!ret)
6863 		ret = err;
6864 	return ret;
6865 }
6866 
6867 static int ext4_release_dquot(struct dquot *dquot)
6868 {
6869 	int ret, err;
6870 	handle_t *handle;
6871 
6872 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6873 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6874 	if (IS_ERR(handle)) {
6875 		/* Release dquot anyway to avoid endless cycle in dqput() */
6876 		dquot_release(dquot);
6877 		return PTR_ERR(handle);
6878 	}
6879 	ret = dquot_release(dquot);
6880 	if (ret < 0)
6881 		ext4_error_err(dquot->dq_sb, -ret,
6882 			       "Failed to release dquot type %d",
6883 			       dquot->dq_id.type);
6884 	err = ext4_journal_stop(handle);
6885 	if (!ret)
6886 		ret = err;
6887 	return ret;
6888 }
6889 
6890 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6891 {
6892 	struct super_block *sb = dquot->dq_sb;
6893 
6894 	if (ext4_is_quota_journalled(sb)) {
6895 		dquot_mark_dquot_dirty(dquot);
6896 		return ext4_write_dquot(dquot);
6897 	} else {
6898 		return dquot_mark_dquot_dirty(dquot);
6899 	}
6900 }
6901 
6902 static int ext4_write_info(struct super_block *sb, int type)
6903 {
6904 	int ret, err;
6905 	handle_t *handle;
6906 
6907 	/* Data block + inode block */
6908 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6909 	if (IS_ERR(handle))
6910 		return PTR_ERR(handle);
6911 	ret = dquot_commit_info(sb, type);
6912 	err = ext4_journal_stop(handle);
6913 	if (!ret)
6914 		ret = err;
6915 	return ret;
6916 }
6917 
6918 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6919 {
6920 	struct ext4_inode_info *ei = EXT4_I(inode);
6921 
6922 	/* The first argument of lockdep_set_subclass has to be
6923 	 * *exactly* the same as the argument to init_rwsem() --- in
6924 	 * this case, in init_once() --- or lockdep gets unhappy
6925 	 * because the name of the lock is set using the
6926 	 * stringification of the argument to init_rwsem().
6927 	 */
6928 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6929 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6930 }
6931 
6932 /*
6933  * Standard function to be called on quota_on
6934  */
6935 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6936 			 const struct path *path)
6937 {
6938 	int err;
6939 
6940 	if (!test_opt(sb, QUOTA))
6941 		return -EINVAL;
6942 
6943 	/* Quotafile not on the same filesystem? */
6944 	if (path->dentry->d_sb != sb)
6945 		return -EXDEV;
6946 
6947 	/* Quota already enabled for this file? */
6948 	if (IS_NOQUOTA(d_inode(path->dentry)))
6949 		return -EBUSY;
6950 
6951 	/* Journaling quota? */
6952 	if (EXT4_SB(sb)->s_qf_names[type]) {
6953 		/* Quotafile not in fs root? */
6954 		if (path->dentry->d_parent != sb->s_root)
6955 			ext4_msg(sb, KERN_WARNING,
6956 				"Quota file not on filesystem root. "
6957 				"Journaled quota will not work");
6958 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6959 	} else {
6960 		/*
6961 		 * Clear the flag just in case mount options changed since
6962 		 * last time.
6963 		 */
6964 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6965 	}
6966 
6967 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6968 	err = dquot_quota_on(sb, type, format_id, path);
6969 	if (!err) {
6970 		struct inode *inode = d_inode(path->dentry);
6971 		handle_t *handle;
6972 
6973 		/*
6974 		 * Set inode flags to prevent userspace from messing with quota
6975 		 * files. If this fails, we return success anyway since quotas
6976 		 * are already enabled and this is not a hard failure.
6977 		 */
6978 		inode_lock(inode);
6979 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6980 		if (IS_ERR(handle))
6981 			goto unlock_inode;
6982 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6983 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6984 				S_NOATIME | S_IMMUTABLE);
6985 		err = ext4_mark_inode_dirty(handle, inode);
6986 		ext4_journal_stop(handle);
6987 	unlock_inode:
6988 		inode_unlock(inode);
6989 		if (err)
6990 			dquot_quota_off(sb, type);
6991 	}
6992 	if (err)
6993 		lockdep_set_quota_inode(path->dentry->d_inode,
6994 					     I_DATA_SEM_NORMAL);
6995 	return err;
6996 }
6997 
6998 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
6999 {
7000 	switch (type) {
7001 	case USRQUOTA:
7002 		return qf_inum == EXT4_USR_QUOTA_INO;
7003 	case GRPQUOTA:
7004 		return qf_inum == EXT4_GRP_QUOTA_INO;
7005 	case PRJQUOTA:
7006 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7007 	default:
7008 		BUG();
7009 	}
7010 }
7011 
7012 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7013 			     unsigned int flags)
7014 {
7015 	int err;
7016 	struct inode *qf_inode;
7017 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7018 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7019 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7020 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7021 	};
7022 
7023 	BUG_ON(!ext4_has_feature_quota(sb));
7024 
7025 	if (!qf_inums[type])
7026 		return -EPERM;
7027 
7028 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7029 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7030 				qf_inums[type], type);
7031 		return -EUCLEAN;
7032 	}
7033 
7034 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7035 	if (IS_ERR(qf_inode)) {
7036 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7037 				qf_inums[type], type);
7038 		return PTR_ERR(qf_inode);
7039 	}
7040 
7041 	/* Don't account quota for quota files to avoid recursion */
7042 	qf_inode->i_flags |= S_NOQUOTA;
7043 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7044 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7045 	if (err)
7046 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7047 	iput(qf_inode);
7048 
7049 	return err;
7050 }
7051 
7052 /* Enable usage tracking for all quota types. */
7053 int ext4_enable_quotas(struct super_block *sb)
7054 {
7055 	int type, err = 0;
7056 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7057 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7058 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7059 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7060 	};
7061 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7062 		test_opt(sb, USRQUOTA),
7063 		test_opt(sb, GRPQUOTA),
7064 		test_opt(sb, PRJQUOTA),
7065 	};
7066 
7067 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7068 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7069 		if (qf_inums[type]) {
7070 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7071 				DQUOT_USAGE_ENABLED |
7072 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7073 			if (err) {
7074 				ext4_warning(sb,
7075 					"Failed to enable quota tracking "
7076 					"(type=%d, err=%d, ino=%lu). "
7077 					"Please run e2fsck to fix.", type,
7078 					err, qf_inums[type]);
7079 
7080 				ext4_quotas_off(sb, type);
7081 				return err;
7082 			}
7083 		}
7084 	}
7085 	return 0;
7086 }
7087 
7088 static int ext4_quota_off(struct super_block *sb, int type)
7089 {
7090 	struct inode *inode = sb_dqopt(sb)->files[type];
7091 	handle_t *handle;
7092 	int err;
7093 
7094 	/* Force all delayed allocation blocks to be allocated.
7095 	 * Caller already holds s_umount sem */
7096 	if (test_opt(sb, DELALLOC))
7097 		sync_filesystem(sb);
7098 
7099 	if (!inode || !igrab(inode))
7100 		goto out;
7101 
7102 	err = dquot_quota_off(sb, type);
7103 	if (err || ext4_has_feature_quota(sb))
7104 		goto out_put;
7105 	/*
7106 	 * When the filesystem was remounted read-only first, we cannot cleanup
7107 	 * inode flags here. Bad luck but people should be using QUOTA feature
7108 	 * these days anyway.
7109 	 */
7110 	if (sb_rdonly(sb))
7111 		goto out_put;
7112 
7113 	inode_lock(inode);
7114 	/*
7115 	 * Update modification times of quota files when userspace can
7116 	 * start looking at them. If we fail, we return success anyway since
7117 	 * this is not a hard failure and quotas are already disabled.
7118 	 */
7119 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7120 	if (IS_ERR(handle)) {
7121 		err = PTR_ERR(handle);
7122 		goto out_unlock;
7123 	}
7124 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7125 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7126 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
7127 	err = ext4_mark_inode_dirty(handle, inode);
7128 	ext4_journal_stop(handle);
7129 out_unlock:
7130 	inode_unlock(inode);
7131 out_put:
7132 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7133 	iput(inode);
7134 	return err;
7135 out:
7136 	return dquot_quota_off(sb, type);
7137 }
7138 
7139 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7140  * acquiring the locks... As quota files are never truncated and quota code
7141  * itself serializes the operations (and no one else should touch the files)
7142  * we don't have to be afraid of races */
7143 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7144 			       size_t len, loff_t off)
7145 {
7146 	struct inode *inode = sb_dqopt(sb)->files[type];
7147 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7148 	int offset = off & (sb->s_blocksize - 1);
7149 	int tocopy;
7150 	size_t toread;
7151 	struct buffer_head *bh;
7152 	loff_t i_size = i_size_read(inode);
7153 
7154 	if (off > i_size)
7155 		return 0;
7156 	if (off+len > i_size)
7157 		len = i_size-off;
7158 	toread = len;
7159 	while (toread > 0) {
7160 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7161 		bh = ext4_bread(NULL, inode, blk, 0);
7162 		if (IS_ERR(bh))
7163 			return PTR_ERR(bh);
7164 		if (!bh)	/* A hole? */
7165 			memset(data, 0, tocopy);
7166 		else
7167 			memcpy(data, bh->b_data+offset, tocopy);
7168 		brelse(bh);
7169 		offset = 0;
7170 		toread -= tocopy;
7171 		data += tocopy;
7172 		blk++;
7173 	}
7174 	return len;
7175 }
7176 
7177 /* Write to quotafile (we know the transaction is already started and has
7178  * enough credits) */
7179 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7180 				const char *data, size_t len, loff_t off)
7181 {
7182 	struct inode *inode = sb_dqopt(sb)->files[type];
7183 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7184 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7185 	int retries = 0;
7186 	struct buffer_head *bh;
7187 	handle_t *handle = journal_current_handle();
7188 
7189 	if (!handle) {
7190 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7191 			" cancelled because transaction is not started",
7192 			(unsigned long long)off, (unsigned long long)len);
7193 		return -EIO;
7194 	}
7195 	/*
7196 	 * Since we account only one data block in transaction credits,
7197 	 * then it is impossible to cross a block boundary.
7198 	 */
7199 	if (sb->s_blocksize - offset < len) {
7200 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7201 			" cancelled because not block aligned",
7202 			(unsigned long long)off, (unsigned long long)len);
7203 		return -EIO;
7204 	}
7205 
7206 	do {
7207 		bh = ext4_bread(handle, inode, blk,
7208 				EXT4_GET_BLOCKS_CREATE |
7209 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7210 	} while (PTR_ERR(bh) == -ENOSPC &&
7211 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7212 	if (IS_ERR(bh))
7213 		return PTR_ERR(bh);
7214 	if (!bh)
7215 		goto out;
7216 	BUFFER_TRACE(bh, "get write access");
7217 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7218 	if (err) {
7219 		brelse(bh);
7220 		return err;
7221 	}
7222 	lock_buffer(bh);
7223 	memcpy(bh->b_data+offset, data, len);
7224 	flush_dcache_page(bh->b_page);
7225 	unlock_buffer(bh);
7226 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7227 	brelse(bh);
7228 out:
7229 	if (inode->i_size < off + len) {
7230 		i_size_write(inode, off + len);
7231 		EXT4_I(inode)->i_disksize = inode->i_size;
7232 		err2 = ext4_mark_inode_dirty(handle, inode);
7233 		if (unlikely(err2 && !err))
7234 			err = err2;
7235 	}
7236 	return err ? err : len;
7237 }
7238 #endif
7239 
7240 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7241 static inline void register_as_ext2(void)
7242 {
7243 	int err = register_filesystem(&ext2_fs_type);
7244 	if (err)
7245 		printk(KERN_WARNING
7246 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7247 }
7248 
7249 static inline void unregister_as_ext2(void)
7250 {
7251 	unregister_filesystem(&ext2_fs_type);
7252 }
7253 
7254 static inline int ext2_feature_set_ok(struct super_block *sb)
7255 {
7256 	if (ext4_has_unknown_ext2_incompat_features(sb))
7257 		return 0;
7258 	if (sb_rdonly(sb))
7259 		return 1;
7260 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7261 		return 0;
7262 	return 1;
7263 }
7264 #else
7265 static inline void register_as_ext2(void) { }
7266 static inline void unregister_as_ext2(void) { }
7267 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7268 #endif
7269 
7270 static inline void register_as_ext3(void)
7271 {
7272 	int err = register_filesystem(&ext3_fs_type);
7273 	if (err)
7274 		printk(KERN_WARNING
7275 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7276 }
7277 
7278 static inline void unregister_as_ext3(void)
7279 {
7280 	unregister_filesystem(&ext3_fs_type);
7281 }
7282 
7283 static inline int ext3_feature_set_ok(struct super_block *sb)
7284 {
7285 	if (ext4_has_unknown_ext3_incompat_features(sb))
7286 		return 0;
7287 	if (!ext4_has_feature_journal(sb))
7288 		return 0;
7289 	if (sb_rdonly(sb))
7290 		return 1;
7291 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7292 		return 0;
7293 	return 1;
7294 }
7295 
7296 static void ext4_kill_sb(struct super_block *sb)
7297 {
7298 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7299 	struct file *bdev_file = sbi ? sbi->s_journal_bdev_file : NULL;
7300 
7301 	kill_block_super(sb);
7302 
7303 	if (bdev_file)
7304 		bdev_fput(bdev_file);
7305 }
7306 
7307 static struct file_system_type ext4_fs_type = {
7308 	.owner			= THIS_MODULE,
7309 	.name			= "ext4",
7310 	.init_fs_context	= ext4_init_fs_context,
7311 	.parameters		= ext4_param_specs,
7312 	.kill_sb		= ext4_kill_sb,
7313 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7314 };
7315 MODULE_ALIAS_FS("ext4");
7316 
7317 /* Shared across all ext4 file systems */
7318 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7319 
7320 static int __init ext4_init_fs(void)
7321 {
7322 	int i, err;
7323 
7324 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7325 	ext4_li_info = NULL;
7326 
7327 	/* Build-time check for flags consistency */
7328 	ext4_check_flag_values();
7329 
7330 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7331 		init_waitqueue_head(&ext4__ioend_wq[i]);
7332 
7333 	err = ext4_init_es();
7334 	if (err)
7335 		return err;
7336 
7337 	err = ext4_init_pending();
7338 	if (err)
7339 		goto out7;
7340 
7341 	err = ext4_init_post_read_processing();
7342 	if (err)
7343 		goto out6;
7344 
7345 	err = ext4_init_pageio();
7346 	if (err)
7347 		goto out5;
7348 
7349 	err = ext4_init_system_zone();
7350 	if (err)
7351 		goto out4;
7352 
7353 	err = ext4_init_sysfs();
7354 	if (err)
7355 		goto out3;
7356 
7357 	err = ext4_init_mballoc();
7358 	if (err)
7359 		goto out2;
7360 	err = init_inodecache();
7361 	if (err)
7362 		goto out1;
7363 
7364 	err = ext4_fc_init_dentry_cache();
7365 	if (err)
7366 		goto out05;
7367 
7368 	register_as_ext3();
7369 	register_as_ext2();
7370 	err = register_filesystem(&ext4_fs_type);
7371 	if (err)
7372 		goto out;
7373 
7374 	return 0;
7375 out:
7376 	unregister_as_ext2();
7377 	unregister_as_ext3();
7378 	ext4_fc_destroy_dentry_cache();
7379 out05:
7380 	destroy_inodecache();
7381 out1:
7382 	ext4_exit_mballoc();
7383 out2:
7384 	ext4_exit_sysfs();
7385 out3:
7386 	ext4_exit_system_zone();
7387 out4:
7388 	ext4_exit_pageio();
7389 out5:
7390 	ext4_exit_post_read_processing();
7391 out6:
7392 	ext4_exit_pending();
7393 out7:
7394 	ext4_exit_es();
7395 
7396 	return err;
7397 }
7398 
7399 static void __exit ext4_exit_fs(void)
7400 {
7401 	ext4_destroy_lazyinit_thread();
7402 	unregister_as_ext2();
7403 	unregister_as_ext3();
7404 	unregister_filesystem(&ext4_fs_type);
7405 	ext4_fc_destroy_dentry_cache();
7406 	destroy_inodecache();
7407 	ext4_exit_mballoc();
7408 	ext4_exit_sysfs();
7409 	ext4_exit_system_zone();
7410 	ext4_exit_pageio();
7411 	ext4_exit_post_read_processing();
7412 	ext4_exit_es();
7413 	ext4_exit_pending();
7414 }
7415 
7416 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7417 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7418 MODULE_LICENSE("GPL");
7419 MODULE_SOFTDEP("pre: crc32c");
7420 module_init(ext4_init_fs)
7421 module_exit(ext4_exit_fs)
7422