xref: /linux/fs/ext4/super.c (revision 69050f8d6d075dc01af7a5f2f550a8067510366f)
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 #include <linux/fserror.h>
52 
53 #include "ext4.h"
54 #include "ext4_extents.h"	/* Needed for trace points definition */
55 #include "ext4_jbd2.h"
56 #include "xattr.h"
57 #include "acl.h"
58 #include "mballoc.h"
59 #include "fsmap.h"
60 
61 #define CREATE_TRACE_POINTS
62 #include <trace/events/ext4.h>
63 
64 static struct ext4_lazy_init *ext4_li_info;
65 static DEFINE_MUTEX(ext4_li_mtx);
66 static struct ratelimit_state ext4_mount_msg_ratelimit;
67 
68 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
69 			     unsigned long journal_devnum);
70 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
71 static void ext4_update_super(struct super_block *sb);
72 static int ext4_commit_super(struct super_block *sb);
73 static int ext4_mark_recovery_complete(struct super_block *sb,
74 					struct ext4_super_block *es);
75 static int ext4_clear_journal_err(struct super_block *sb,
76 				  struct ext4_super_block *es);
77 static int ext4_sync_fs(struct super_block *sb, int wait);
78 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
79 static int ext4_unfreeze(struct super_block *sb);
80 static int ext4_freeze(struct super_block *sb);
81 static inline int ext2_feature_set_ok(struct super_block *sb);
82 static inline int ext3_feature_set_ok(struct super_block *sb);
83 static 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, bool simu_fail)
165 {
166 	if (simu_fail) {
167 		clear_buffer_uptodate(bh);
168 		unlock_buffer(bh);
169 		return;
170 	}
171 
172 	/*
173 	 * buffer's verified bit is no longer valid after reading from
174 	 * disk again due to write out error, clear it to make sure we
175 	 * recheck the buffer contents.
176 	 */
177 	clear_buffer_verified(bh);
178 
179 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
180 	get_bh(bh);
181 	submit_bh(REQ_OP_READ | op_flags, bh);
182 }
183 
184 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
185 			 bh_end_io_t *end_io, bool simu_fail)
186 {
187 	BUG_ON(!buffer_locked(bh));
188 
189 	if (ext4_buffer_uptodate(bh)) {
190 		unlock_buffer(bh);
191 		return;
192 	}
193 	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
194 }
195 
196 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
197 		 bh_end_io_t *end_io, bool simu_fail)
198 {
199 	BUG_ON(!buffer_locked(bh));
200 
201 	if (ext4_buffer_uptodate(bh)) {
202 		unlock_buffer(bh);
203 		return 0;
204 	}
205 
206 	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
207 
208 	wait_on_buffer(bh);
209 	if (buffer_uptodate(bh))
210 		return 0;
211 	return -EIO;
212 }
213 
214 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
215 {
216 	lock_buffer(bh);
217 	if (!wait) {
218 		ext4_read_bh_nowait(bh, op_flags, NULL, false);
219 		return 0;
220 	}
221 	return ext4_read_bh(bh, op_flags, NULL, false);
222 }
223 
224 /*
225  * This works like __bread_gfp() except it uses ERR_PTR for error
226  * returns.  Currently with sb_bread it's impossible to distinguish
227  * between ENOMEM and EIO situations (since both result in a NULL
228  * return.
229  */
230 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
231 					       sector_t block,
232 					       blk_opf_t op_flags, gfp_t gfp)
233 {
234 	struct buffer_head *bh;
235 	int ret;
236 
237 	bh = sb_getblk_gfp(sb, block, gfp);
238 	if (bh == NULL)
239 		return ERR_PTR(-ENOMEM);
240 	if (ext4_buffer_uptodate(bh))
241 		return bh;
242 
243 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
244 	if (ret) {
245 		put_bh(bh);
246 		return ERR_PTR(ret);
247 	}
248 	return bh;
249 }
250 
251 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
252 				   blk_opf_t op_flags)
253 {
254 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
255 			~__GFP_FS) | __GFP_MOVABLE;
256 
257 	return __ext4_sb_bread_gfp(sb, block, op_flags, gfp);
258 }
259 
260 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
261 					    sector_t block)
262 {
263 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
264 			~__GFP_FS);
265 
266 	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
267 }
268 
269 struct buffer_head *ext4_sb_bread_nofail(struct super_block *sb,
270 					 sector_t block)
271 {
272 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
273 			~__GFP_FS) | __GFP_MOVABLE | __GFP_NOFAIL;
274 
275 	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
276 }
277 
278 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
279 {
280 	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
281 			sb->s_blocksize, GFP_NOWAIT);
282 
283 	if (likely(bh)) {
284 		if (trylock_buffer(bh))
285 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL, false);
286 		brelse(bh);
287 	}
288 }
289 
290 static int ext4_verify_csum_type(struct super_block *sb,
291 				 struct ext4_super_block *es)
292 {
293 	if (!ext4_has_feature_metadata_csum(sb))
294 		return 1;
295 
296 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
297 }
298 
299 __le32 ext4_superblock_csum(struct ext4_super_block *es)
300 {
301 	int offset = offsetof(struct ext4_super_block, s_checksum);
302 	__u32 csum;
303 
304 	csum = ext4_chksum(~0, (char *)es, offset);
305 
306 	return cpu_to_le32(csum);
307 }
308 
309 static int ext4_superblock_csum_verify(struct super_block *sb,
310 				       struct ext4_super_block *es)
311 {
312 	if (!ext4_has_feature_metadata_csum(sb))
313 		return 1;
314 
315 	return es->s_checksum == ext4_superblock_csum(es);
316 }
317 
318 void ext4_superblock_csum_set(struct super_block *sb)
319 {
320 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
321 
322 	if (!ext4_has_feature_metadata_csum(sb))
323 		return;
324 
325 	es->s_checksum = ext4_superblock_csum(es);
326 }
327 
328 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
329 			       struct ext4_group_desc *bg)
330 {
331 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
332 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
333 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
334 }
335 
336 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
337 			       struct ext4_group_desc *bg)
338 {
339 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
340 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
341 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
342 }
343 
344 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
345 			      struct ext4_group_desc *bg)
346 {
347 	return le32_to_cpu(bg->bg_inode_table_lo) |
348 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
349 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
350 }
351 
352 __u32 ext4_free_group_clusters(struct super_block *sb,
353 			       struct ext4_group_desc *bg)
354 {
355 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
356 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
357 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
358 }
359 
360 __u32 ext4_free_inodes_count(struct super_block *sb,
361 			      struct ext4_group_desc *bg)
362 {
363 	return le16_to_cpu(READ_ONCE(bg->bg_free_inodes_count_lo)) |
364 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
365 		 (__u32)le16_to_cpu(READ_ONCE(bg->bg_free_inodes_count_hi)) << 16 : 0);
366 }
367 
368 __u32 ext4_used_dirs_count(struct super_block *sb,
369 			      struct ext4_group_desc *bg)
370 {
371 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
372 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
373 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
374 }
375 
376 __u32 ext4_itable_unused_count(struct super_block *sb,
377 			      struct ext4_group_desc *bg)
378 {
379 	return le16_to_cpu(bg->bg_itable_unused_lo) |
380 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
381 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
382 }
383 
384 void ext4_block_bitmap_set(struct super_block *sb,
385 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
386 {
387 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
388 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
389 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
390 }
391 
392 void ext4_inode_bitmap_set(struct super_block *sb,
393 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
394 {
395 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
396 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
397 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
398 }
399 
400 void ext4_inode_table_set(struct super_block *sb,
401 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
402 {
403 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
404 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
405 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
406 }
407 
408 void ext4_free_group_clusters_set(struct super_block *sb,
409 				  struct ext4_group_desc *bg, __u32 count)
410 {
411 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
412 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
413 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
414 }
415 
416 void ext4_free_inodes_set(struct super_block *sb,
417 			  struct ext4_group_desc *bg, __u32 count)
418 {
419 	WRITE_ONCE(bg->bg_free_inodes_count_lo, cpu_to_le16((__u16)count));
420 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
421 		WRITE_ONCE(bg->bg_free_inodes_count_hi, cpu_to_le16(count >> 16));
422 }
423 
424 void ext4_used_dirs_set(struct super_block *sb,
425 			  struct ext4_group_desc *bg, __u32 count)
426 {
427 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
428 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
429 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
430 }
431 
432 void ext4_itable_unused_set(struct super_block *sb,
433 			  struct ext4_group_desc *bg, __u32 count)
434 {
435 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
436 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
437 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
438 }
439 
440 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
441 {
442 	now = clamp_val(now, 0, (1ull << 40) - 1);
443 
444 	*lo = cpu_to_le32(lower_32_bits(now));
445 	*hi = upper_32_bits(now);
446 }
447 
448 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
449 {
450 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
451 }
452 #define ext4_update_tstamp(es, tstamp) \
453 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
454 			     ktime_get_real_seconds())
455 #define ext4_get_tstamp(es, tstamp) \
456 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
457 
458 /*
459  * The ext4_maybe_update_superblock() function checks and updates the
460  * superblock if needed.
461  *
462  * This function is designed to update the on-disk superblock only under
463  * certain conditions to prevent excessive disk writes and unnecessary
464  * waking of the disk from sleep. The superblock will be updated if:
465  * 1. More than sbi->s_sb_update_sec (def: 1 hour) has passed since the last
466  *    superblock update
467  * 2. More than sbi->s_sb_update_kb (def: 16MB) kbs have been written since the
468  *    last superblock update.
469  *
470  * @sb: The superblock
471  */
472 static void ext4_maybe_update_superblock(struct super_block *sb)
473 {
474 	struct ext4_sb_info *sbi = EXT4_SB(sb);
475 	struct ext4_super_block *es = sbi->s_es;
476 	journal_t *journal = sbi->s_journal;
477 	time64_t now;
478 	__u64 last_update;
479 	__u64 lifetime_write_kbytes;
480 	__u64 diff_size;
481 
482 	if (ext4_emergency_state(sb) || sb_rdonly(sb) ||
483 	    !(sb->s_flags & SB_ACTIVE) || !journal ||
484 	    journal->j_flags & JBD2_UNMOUNT)
485 		return;
486 
487 	now = ktime_get_real_seconds();
488 	last_update = ext4_get_tstamp(es, s_wtime);
489 
490 	if (likely(now - last_update < sbi->s_sb_update_sec))
491 		return;
492 
493 	lifetime_write_kbytes = sbi->s_kbytes_written +
494 		((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
495 		  sbi->s_sectors_written_start) >> 1);
496 
497 	/* Get the number of kilobytes not written to disk to account
498 	 * for statistics and compare with a multiple of 16 MB. This
499 	 * is used to determine when the next superblock commit should
500 	 * occur (i.e. not more often than once per 16MB if there was
501 	 * less written in an hour).
502 	 */
503 	diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written);
504 
505 	if (diff_size > sbi->s_sb_update_kb)
506 		schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
507 }
508 
509 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
510 {
511 	struct super_block		*sb = journal->j_private;
512 
513 	BUG_ON(txn->t_state == T_FINISHED);
514 
515 	ext4_process_freed_data(sb, txn->t_tid);
516 	ext4_maybe_update_superblock(sb);
517 }
518 
519 static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode,
520 		struct folio *folio)
521 {
522 	struct buffer_head *bh, *head;
523 	struct journal_head *jh;
524 
525 	bh = head = folio_buffers(folio);
526 	do {
527 		/*
528 		 * We have to redirty a page in these cases:
529 		 * 1) If buffer is dirty, it means the page was dirty because it
530 		 * contains a buffer that needs checkpointing. So the dirty bit
531 		 * needs to be preserved so that checkpointing writes the buffer
532 		 * properly.
533 		 * 2) If buffer is not part of the committing transaction
534 		 * (we may have just accidentally come across this buffer because
535 		 * inode range tracking is not exact) or if the currently running
536 		 * transaction already contains this buffer as well, dirty bit
537 		 * needs to be preserved so that the buffer gets writeprotected
538 		 * properly on running transaction's commit.
539 		 */
540 		jh = bh2jh(bh);
541 		if (buffer_dirty(bh) ||
542 		    (jh && (jh->b_transaction != jinode->i_transaction ||
543 			    jh->b_next_transaction)))
544 			return true;
545 	} while ((bh = bh->b_this_page) != head);
546 
547 	return false;
548 }
549 
550 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
551 {
552 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
553 	struct writeback_control wbc = {
554 		.sync_mode =  WB_SYNC_ALL,
555 		.nr_to_write = LONG_MAX,
556 		.range_start = jinode->i_dirty_start,
557 		.range_end = jinode->i_dirty_end,
558         };
559 	struct folio *folio = NULL;
560 	int error;
561 
562 	/*
563 	 * writeback_iter() already checks for dirty pages and calls
564 	 * folio_clear_dirty_for_io(), which we want to write protect the
565 	 * folios.
566 	 *
567 	 * However, we may have to redirty a folio sometimes.
568 	 */
569 	while ((folio = writeback_iter(mapping, &wbc, folio, &error))) {
570 		if (ext4_journalled_writepage_needs_redirty(jinode, folio))
571 			folio_redirty_for_writepage(&wbc, folio);
572 		folio_unlock(folio);
573 	}
574 
575 	return error;
576 }
577 
578 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
579 {
580 	int ret;
581 
582 	if (ext4_should_journal_data(jinode->i_vfs_inode))
583 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
584 	else
585 		ret = ext4_normal_submit_inode_data_buffers(jinode);
586 	return ret;
587 }
588 
589 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
590 {
591 	int ret = 0;
592 
593 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
594 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
595 
596 	return ret;
597 }
598 
599 static bool system_going_down(void)
600 {
601 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
602 		|| system_state == SYSTEM_RESTART;
603 }
604 
605 struct ext4_err_translation {
606 	int code;
607 	int errno;
608 };
609 
610 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
611 
612 static struct ext4_err_translation err_translation[] = {
613 	EXT4_ERR_TRANSLATE(EIO),
614 	EXT4_ERR_TRANSLATE(ENOMEM),
615 	EXT4_ERR_TRANSLATE(EFSBADCRC),
616 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
617 	EXT4_ERR_TRANSLATE(ENOSPC),
618 	EXT4_ERR_TRANSLATE(ENOKEY),
619 	EXT4_ERR_TRANSLATE(EROFS),
620 	EXT4_ERR_TRANSLATE(EFBIG),
621 	EXT4_ERR_TRANSLATE(EEXIST),
622 	EXT4_ERR_TRANSLATE(ERANGE),
623 	EXT4_ERR_TRANSLATE(EOVERFLOW),
624 	EXT4_ERR_TRANSLATE(EBUSY),
625 	EXT4_ERR_TRANSLATE(ENOTDIR),
626 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
627 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
628 	EXT4_ERR_TRANSLATE(EFAULT),
629 };
630 
631 static int ext4_errno_to_code(int errno)
632 {
633 	int i;
634 
635 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
636 		if (err_translation[i].errno == errno)
637 			return err_translation[i].code;
638 	return EXT4_ERR_UNKNOWN;
639 }
640 
641 static void save_error_info(struct super_block *sb, int error,
642 			    __u32 ino, __u64 block,
643 			    const char *func, unsigned int line)
644 {
645 	struct ext4_sb_info *sbi = EXT4_SB(sb);
646 
647 	/* We default to EFSCORRUPTED error... */
648 	if (error == 0)
649 		error = EFSCORRUPTED;
650 
651 	spin_lock(&sbi->s_error_lock);
652 	sbi->s_add_error_count++;
653 	sbi->s_last_error_code = error;
654 	sbi->s_last_error_line = line;
655 	sbi->s_last_error_ino = ino;
656 	sbi->s_last_error_block = block;
657 	sbi->s_last_error_func = func;
658 	sbi->s_last_error_time = ktime_get_real_seconds();
659 	if (!sbi->s_first_error_time) {
660 		sbi->s_first_error_code = error;
661 		sbi->s_first_error_line = line;
662 		sbi->s_first_error_ino = ino;
663 		sbi->s_first_error_block = block;
664 		sbi->s_first_error_func = func;
665 		sbi->s_first_error_time = sbi->s_last_error_time;
666 	}
667 	spin_unlock(&sbi->s_error_lock);
668 }
669 
670 /* Deal with the reporting of failure conditions on a filesystem such as
671  * inconsistencies detected or read IO failures.
672  *
673  * On ext2, we can store the error state of the filesystem in the
674  * superblock.  That is not possible on ext4, because we may have other
675  * write ordering constraints on the superblock which prevent us from
676  * writing it out straight away; and given that the journal is about to
677  * be aborted, we can't rely on the current, or future, transactions to
678  * write out the superblock safely.
679  *
680  * We'll just use the jbd2_journal_abort() error code to record an error in
681  * the journal instead.  On recovery, the journal will complain about
682  * that error until we've noted it down and cleared it.
683  *
684  * If force_ro is set, we unconditionally force the filesystem into an
685  * ABORT|READONLY state, unless the error response on the fs has been set to
686  * panic in which case we take the easy way out and panic immediately. This is
687  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
688  * at a critical moment in log management.
689  */
690 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
691 			      __u32 ino, __u64 block,
692 			      const char *func, unsigned int line)
693 {
694 	journal_t *journal = EXT4_SB(sb)->s_journal;
695 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
696 
697 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
698 	if (test_opt(sb, WARN_ON_ERROR))
699 		WARN_ON_ONCE(1);
700 
701 	if (!continue_fs && !ext4_emergency_ro(sb) && journal)
702 		jbd2_journal_abort(journal, -error);
703 
704 	if (!bdev_read_only(sb->s_bdev)) {
705 		save_error_info(sb, error, ino, block, func, line);
706 		/*
707 		 * In case the fs should keep running, we need to writeout
708 		 * superblock through the journal. Due to lock ordering
709 		 * constraints, it may not be safe to do it right here so we
710 		 * defer superblock flushing to a workqueue. We just need to be
711 		 * careful when the journal is already shutting down. If we get
712 		 * here in that case, just update the sb directly as the last
713 		 * transaction won't commit anyway.
714 		 */
715 		if (continue_fs && journal &&
716 		    !ext4_test_mount_flag(sb, EXT4_MF_JOURNAL_DESTROY))
717 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
718 		else
719 			ext4_commit_super(sb);
720 	}
721 
722 	/*
723 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
724 	 * could panic during 'reboot -f' as the underlying device got already
725 	 * disabled.
726 	 */
727 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
728 		panic("EXT4-fs (device %s): panic forced after error\n",
729 			sb->s_id);
730 	}
731 
732 	if (ext4_emergency_ro(sb) || continue_fs)
733 		return;
734 
735 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
736 	/*
737 	 * We don't set SB_RDONLY because that requires sb->s_umount
738 	 * semaphore and setting it without proper remount procedure is
739 	 * confusing code such as freeze_super() leading to deadlocks
740 	 * and other problems.
741 	 */
742 	set_bit(EXT4_FLAGS_EMERGENCY_RO, &EXT4_SB(sb)->s_ext4_flags);
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 (!ext4_emergency_state(sbi->s_sb) &&
761 	    !sb_rdonly(sbi->s_sb) && journal) {
762 		struct buffer_head *sbh = sbi->s_sbh;
763 		bool call_notify_err = false;
764 
765 		handle = jbd2_journal_start(journal, 1);
766 		if (IS_ERR(handle))
767 			goto write_directly;
768 		if (jbd2_journal_get_write_access(handle, sbh)) {
769 			jbd2_journal_stop(handle);
770 			goto write_directly;
771 		}
772 
773 		if (sbi->s_add_error_count > 0)
774 			call_notify_err = true;
775 
776 		ext4_update_super(sbi->s_sb);
777 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
778 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
779 				 "superblock detected");
780 			clear_buffer_write_io_error(sbh);
781 			set_buffer_uptodate(sbh);
782 		}
783 
784 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
785 			jbd2_journal_stop(handle);
786 			goto write_directly;
787 		}
788 		jbd2_journal_stop(handle);
789 
790 		if (call_notify_err)
791 			ext4_notify_error_sysfs(sbi);
792 
793 		return;
794 	}
795 write_directly:
796 	/*
797 	 * Write through journal failed. Write sb directly to get error info
798 	 * out and hope for the best.
799 	 */
800 	ext4_commit_super(sbi->s_sb);
801 	ext4_notify_error_sysfs(sbi);
802 }
803 
804 #define ext4_error_ratelimit(sb)					\
805 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
806 			     "EXT4-fs error")
807 
808 void __ext4_error(struct super_block *sb, const char *function,
809 		  unsigned int line, bool force_ro, int error, __u64 block,
810 		  const char *fmt, ...)
811 {
812 	struct va_format vaf;
813 	va_list args;
814 
815 	if (unlikely(ext4_emergency_state(sb)))
816 		return;
817 
818 	trace_ext4_error(sb, function, line);
819 	if (ext4_error_ratelimit(sb)) {
820 		va_start(args, fmt);
821 		vaf.fmt = fmt;
822 		vaf.va = &args;
823 		printk(KERN_CRIT
824 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
825 		       sb->s_id, function, line, current->comm, &vaf);
826 		va_end(args);
827 	}
828 	fserror_report_metadata(sb, error ? -abs(error) : -EFSCORRUPTED,
829 				GFP_ATOMIC);
830 
831 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
832 }
833 
834 void __ext4_error_inode(struct inode *inode, const char *function,
835 			unsigned int line, ext4_fsblk_t block, int error,
836 			const char *fmt, ...)
837 {
838 	va_list args;
839 	struct va_format vaf;
840 
841 	if (unlikely(ext4_emergency_state(inode->i_sb)))
842 		return;
843 
844 	trace_ext4_error(inode->i_sb, function, line);
845 	if (ext4_error_ratelimit(inode->i_sb)) {
846 		va_start(args, fmt);
847 		vaf.fmt = fmt;
848 		vaf.va = &args;
849 		if (block)
850 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
851 			       "inode #%lu: block %llu: comm %s: %pV\n",
852 			       inode->i_sb->s_id, function, line, inode->i_ino,
853 			       block, current->comm, &vaf);
854 		else
855 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
856 			       "inode #%lu: comm %s: %pV\n",
857 			       inode->i_sb->s_id, function, line, inode->i_ino,
858 			       current->comm, &vaf);
859 		va_end(args);
860 	}
861 	fserror_report_file_metadata(inode,
862 				     error ? -abs(error) : -EFSCORRUPTED,
863 				     GFP_ATOMIC);
864 
865 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
866 			  function, line);
867 }
868 
869 void __ext4_error_file(struct file *file, const char *function,
870 		       unsigned int line, ext4_fsblk_t block,
871 		       const char *fmt, ...)
872 {
873 	va_list args;
874 	struct va_format vaf;
875 	struct inode *inode = file_inode(file);
876 	char pathname[80], *path;
877 
878 	if (unlikely(ext4_emergency_state(inode->i_sb)))
879 		return;
880 
881 	trace_ext4_error(inode->i_sb, function, line);
882 	if (ext4_error_ratelimit(inode->i_sb)) {
883 		path = file_path(file, pathname, sizeof(pathname));
884 		if (IS_ERR(path))
885 			path = "(unknown)";
886 		va_start(args, fmt);
887 		vaf.fmt = fmt;
888 		vaf.va = &args;
889 		if (block)
890 			printk(KERN_CRIT
891 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
892 			       "block %llu: comm %s: path %s: %pV\n",
893 			       inode->i_sb->s_id, function, line, inode->i_ino,
894 			       block, current->comm, path, &vaf);
895 		else
896 			printk(KERN_CRIT
897 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
898 			       "comm %s: path %s: %pV\n",
899 			       inode->i_sb->s_id, function, line, inode->i_ino,
900 			       current->comm, path, &vaf);
901 		va_end(args);
902 	}
903 	fserror_report_file_metadata(inode, -EFSCORRUPTED, GFP_ATOMIC);
904 
905 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
906 			  function, line);
907 }
908 
909 const char *ext4_decode_error(struct super_block *sb, int errno,
910 			      char nbuf[16])
911 {
912 	char *errstr = NULL;
913 
914 	switch (errno) {
915 	case -EFSCORRUPTED:
916 		errstr = "Corrupt filesystem";
917 		break;
918 	case -EFSBADCRC:
919 		errstr = "Filesystem failed CRC";
920 		break;
921 	case -EIO:
922 		errstr = "IO failure";
923 		break;
924 	case -ENOMEM:
925 		errstr = "Out of memory";
926 		break;
927 	case -EROFS:
928 		if (!sb || (EXT4_SB(sb)->s_journal &&
929 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
930 			errstr = "Journal has aborted";
931 		else
932 			errstr = "Readonly filesystem";
933 		break;
934 	default:
935 		/* If the caller passed in an extra buffer for unknown
936 		 * errors, textualise them now.  Else we just return
937 		 * NULL. */
938 		if (nbuf) {
939 			/* Check for truncated error codes... */
940 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
941 				errstr = nbuf;
942 		}
943 		break;
944 	}
945 
946 	return errstr;
947 }
948 
949 /* __ext4_std_error decodes expected errors from journaling functions
950  * automatically and invokes the appropriate error response.  */
951 
952 void __ext4_std_error(struct super_block *sb, const char *function,
953 		      unsigned int line, int errno)
954 {
955 	char nbuf[16];
956 	const char *errstr;
957 
958 	if (unlikely(ext4_emergency_state(sb)))
959 		return;
960 
961 	/* Special case: if the error is EROFS, and we're not already
962 	 * inside a transaction, then there's really no point in logging
963 	 * an error. */
964 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
965 		return;
966 
967 	if (ext4_error_ratelimit(sb)) {
968 		errstr = ext4_decode_error(sb, errno, nbuf);
969 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
970 		       sb->s_id, function, line, errstr);
971 	}
972 	fserror_report_metadata(sb, errno ? -abs(errno) : -EFSCORRUPTED,
973 				GFP_ATOMIC);
974 
975 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
976 }
977 
978 void __ext4_msg(struct super_block *sb,
979 		const char *prefix, const char *fmt, ...)
980 {
981 	struct va_format vaf;
982 	va_list args;
983 
984 	if (sb) {
985 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
986 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
987 				  "EXT4-fs"))
988 			return;
989 	}
990 
991 	va_start(args, fmt);
992 	vaf.fmt = fmt;
993 	vaf.va = &args;
994 	if (sb)
995 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
996 	else
997 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
998 	va_end(args);
999 }
1000 
1001 static int ext4_warning_ratelimit(struct super_block *sb)
1002 {
1003 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
1004 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1005 			    "EXT4-fs warning");
1006 }
1007 
1008 void __ext4_warning(struct super_block *sb, const char *function,
1009 		    unsigned int line, const char *fmt, ...)
1010 {
1011 	struct va_format vaf;
1012 	va_list args;
1013 
1014 	if (!ext4_warning_ratelimit(sb))
1015 		return;
1016 
1017 	va_start(args, fmt);
1018 	vaf.fmt = fmt;
1019 	vaf.va = &args;
1020 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1021 	       sb->s_id, function, line, &vaf);
1022 	va_end(args);
1023 }
1024 
1025 void __ext4_warning_inode(const struct inode *inode, const char *function,
1026 			  unsigned int line, const char *fmt, ...)
1027 {
1028 	struct va_format vaf;
1029 	va_list args;
1030 
1031 	if (!ext4_warning_ratelimit(inode->i_sb))
1032 		return;
1033 
1034 	va_start(args, fmt);
1035 	vaf.fmt = fmt;
1036 	vaf.va = &args;
1037 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1038 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
1039 	       function, line, inode->i_ino, current->comm, &vaf);
1040 	va_end(args);
1041 }
1042 
1043 void __ext4_grp_locked_error(const char *function, unsigned int line,
1044 			     struct super_block *sb, ext4_group_t grp,
1045 			     unsigned long ino, ext4_fsblk_t block,
1046 			     const char *fmt, ...)
1047 __releases(bitlock)
1048 __acquires(bitlock)
1049 {
1050 	struct va_format vaf;
1051 	va_list args;
1052 
1053 	if (unlikely(ext4_emergency_state(sb)))
1054 		return;
1055 
1056 	trace_ext4_error(sb, function, line);
1057 	if (ext4_error_ratelimit(sb)) {
1058 		va_start(args, fmt);
1059 		vaf.fmt = fmt;
1060 		vaf.va = &args;
1061 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1062 		       sb->s_id, function, line, grp);
1063 		if (ino)
1064 			printk(KERN_CONT "inode %lu: ", ino);
1065 		if (block)
1066 			printk(KERN_CONT "block %llu:",
1067 			       (unsigned long long) block);
1068 		printk(KERN_CONT "%pV\n", &vaf);
1069 		va_end(args);
1070 	}
1071 
1072 	if (test_opt(sb, ERRORS_CONT)) {
1073 		if (test_opt(sb, WARN_ON_ERROR))
1074 			WARN_ON_ONCE(1);
1075 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1076 		if (!bdev_read_only(sb->s_bdev)) {
1077 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1078 					line);
1079 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1080 		}
1081 		return;
1082 	}
1083 	ext4_unlock_group(sb, grp);
1084 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1085 	/*
1086 	 * We only get here in the ERRORS_RO case; relocking the group
1087 	 * may be dangerous, but nothing bad will happen since the
1088 	 * filesystem will have already been marked read/only and the
1089 	 * journal has been aborted.  We return 1 as a hint to callers
1090 	 * who might what to use the return value from
1091 	 * ext4_grp_locked_error() to distinguish between the
1092 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1093 	 * aggressively from the ext4 function in question, with a
1094 	 * more appropriate error code.
1095 	 */
1096 	ext4_lock_group(sb, grp);
1097 	return;
1098 }
1099 
1100 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1101 				     ext4_group_t group,
1102 				     unsigned int flags)
1103 {
1104 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1105 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1106 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1107 	int ret;
1108 
1109 	if (!grp || !gdp)
1110 		return;
1111 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1112 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1113 					    &grp->bb_state);
1114 		if (!ret)
1115 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1116 					   grp->bb_free);
1117 	}
1118 
1119 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1120 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1121 					    &grp->bb_state);
1122 		if (!ret && gdp) {
1123 			int count;
1124 
1125 			count = ext4_free_inodes_count(sb, gdp);
1126 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1127 					   count);
1128 		}
1129 	}
1130 }
1131 
1132 void ext4_update_dynamic_rev(struct super_block *sb)
1133 {
1134 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1135 
1136 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1137 		return;
1138 
1139 	ext4_warning(sb,
1140 		     "updating to rev %d because of new feature flag, "
1141 		     "running e2fsck is recommended",
1142 		     EXT4_DYNAMIC_REV);
1143 
1144 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1145 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1146 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1147 	/* leave es->s_feature_*compat flags alone */
1148 	/* es->s_uuid will be set by e2fsck if empty */
1149 
1150 	/*
1151 	 * The rest of the superblock fields should be zero, and if not it
1152 	 * means they are likely already in use, so leave them alone.  We
1153 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1154 	 */
1155 }
1156 
1157 static inline struct inode *orphan_list_entry(struct list_head *l)
1158 {
1159 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1160 }
1161 
1162 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1163 {
1164 	struct list_head *l;
1165 
1166 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1167 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1168 
1169 	printk(KERN_ERR "sb_info orphan list:\n");
1170 	list_for_each(l, &sbi->s_orphan) {
1171 		struct inode *inode = orphan_list_entry(l);
1172 		printk(KERN_ERR "  "
1173 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1174 		       inode->i_sb->s_id, inode->i_ino, inode,
1175 		       inode->i_mode, inode->i_nlink,
1176 		       NEXT_ORPHAN(inode));
1177 	}
1178 }
1179 
1180 #ifdef CONFIG_QUOTA
1181 static int ext4_quota_off(struct super_block *sb, int type);
1182 
1183 static inline void ext4_quotas_off(struct super_block *sb, int type)
1184 {
1185 	BUG_ON(type > EXT4_MAXQUOTAS);
1186 
1187 	/* Use our quota_off function to clear inode flags etc. */
1188 	for (type--; type >= 0; type--)
1189 		ext4_quota_off(sb, type);
1190 }
1191 
1192 /*
1193  * This is a helper function which is used in the mount/remount
1194  * codepaths (which holds s_umount) to fetch the quota file name.
1195  */
1196 static inline char *get_qf_name(struct super_block *sb,
1197 				struct ext4_sb_info *sbi,
1198 				int type)
1199 {
1200 	return rcu_dereference_protected(sbi->s_qf_names[type],
1201 					 lockdep_is_held(&sb->s_umount));
1202 }
1203 #else
1204 static inline void ext4_quotas_off(struct super_block *sb, int type)
1205 {
1206 }
1207 #endif
1208 
1209 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1210 {
1211 	ext4_fsblk_t block;
1212 	int err;
1213 
1214 	block = ext4_count_free_clusters(sbi->s_sb);
1215 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1216 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1217 				  GFP_KERNEL);
1218 	if (!err) {
1219 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1220 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1221 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1222 					  GFP_KERNEL);
1223 	}
1224 	if (!err)
1225 		err = percpu_counter_init(&sbi->s_dirs_counter,
1226 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1227 	if (!err)
1228 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1229 					  GFP_KERNEL);
1230 	if (!err)
1231 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1232 					  GFP_KERNEL);
1233 	if (!err)
1234 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1235 
1236 	if (err)
1237 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1238 
1239 	return err;
1240 }
1241 
1242 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1243 {
1244 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1245 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1246 	percpu_counter_destroy(&sbi->s_dirs_counter);
1247 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1248 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1249 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1250 }
1251 
1252 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1253 {
1254 	struct buffer_head **group_desc;
1255 	int i;
1256 
1257 	rcu_read_lock();
1258 	group_desc = rcu_dereference(sbi->s_group_desc);
1259 	for (i = 0; i < sbi->s_gdb_count; i++)
1260 		brelse(group_desc[i]);
1261 	kvfree(group_desc);
1262 	rcu_read_unlock();
1263 }
1264 
1265 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1266 {
1267 	struct flex_groups **flex_groups;
1268 	int i;
1269 
1270 	rcu_read_lock();
1271 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1272 	if (flex_groups) {
1273 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1274 			kvfree(flex_groups[i]);
1275 		kvfree(flex_groups);
1276 	}
1277 	rcu_read_unlock();
1278 }
1279 
1280 static void ext4_put_super(struct super_block *sb)
1281 {
1282 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1283 	struct ext4_super_block *es = sbi->s_es;
1284 	int aborted = 0;
1285 	int err;
1286 
1287 	/*
1288 	 * Unregister sysfs before destroying jbd2 journal.
1289 	 * Since we could still access attr_journal_task attribute via sysfs
1290 	 * path which could have sbi->s_journal->j_task as NULL
1291 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1292 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1293 	 * read metadata verify failed then will queue error work.
1294 	 * update_super_work will call start_this_handle may trigger
1295 	 * BUG_ON.
1296 	 */
1297 	ext4_unregister_sysfs(sb);
1298 
1299 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1300 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1301 			 &sb->s_uuid);
1302 
1303 	ext4_unregister_li_request(sb);
1304 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1305 
1306 	destroy_workqueue(sbi->rsv_conversion_wq);
1307 	ext4_release_orphan_info(sb);
1308 
1309 	if (sbi->s_journal) {
1310 		aborted = is_journal_aborted(sbi->s_journal);
1311 		err = ext4_journal_destroy(sbi, sbi->s_journal);
1312 		if ((err < 0) && !aborted) {
1313 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1314 		}
1315 	} else
1316 		flush_work(&sbi->s_sb_upd_work);
1317 
1318 	ext4_es_unregister_shrinker(sbi);
1319 	timer_shutdown_sync(&sbi->s_err_report);
1320 	ext4_release_system_zone(sb);
1321 	ext4_mb_release(sb);
1322 	ext4_ext_release(sb);
1323 
1324 	if (!ext4_emergency_state(sb) && !sb_rdonly(sb)) {
1325 		if (!aborted) {
1326 			ext4_clear_feature_journal_needs_recovery(sb);
1327 			ext4_clear_feature_orphan_present(sb);
1328 			es->s_state = cpu_to_le16(sbi->s_mount_state);
1329 		}
1330 		ext4_commit_super(sb);
1331 	}
1332 
1333 	ext4_group_desc_free(sbi);
1334 	ext4_flex_groups_free(sbi);
1335 
1336 	WARN_ON_ONCE(!(sbi->s_mount_state & EXT4_ERROR_FS) &&
1337 		     percpu_counter_sum(&sbi->s_dirtyclusters_counter));
1338 	ext4_percpu_param_destroy(sbi);
1339 #ifdef CONFIG_QUOTA
1340 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1341 		kfree(get_qf_name(sb, sbi, i));
1342 #endif
1343 
1344 	/* Debugging code just in case the in-memory inode orphan list
1345 	 * isn't empty.  The on-disk one can be non-empty if we've
1346 	 * detected an error and taken the fs readonly, but the
1347 	 * in-memory list had better be clean by this point. */
1348 	if (!list_empty(&sbi->s_orphan))
1349 		dump_orphan_list(sb, sbi);
1350 	ASSERT(list_empty(&sbi->s_orphan));
1351 
1352 	sync_blockdev(sb->s_bdev);
1353 	invalidate_bdev(sb->s_bdev);
1354 	if (sbi->s_journal_bdev_file) {
1355 		/*
1356 		 * Invalidate the journal device's buffers.  We don't want them
1357 		 * floating about in memory - the physical journal device may
1358 		 * hotswapped, and it breaks the `ro-after' testing code.
1359 		 */
1360 		sync_blockdev(file_bdev(sbi->s_journal_bdev_file));
1361 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
1362 	}
1363 
1364 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1365 	sbi->s_ea_inode_cache = NULL;
1366 
1367 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1368 	sbi->s_ea_block_cache = NULL;
1369 
1370 	ext4_stop_mmpd(sbi);
1371 
1372 	brelse(sbi->s_sbh);
1373 	sb->s_fs_info = NULL;
1374 	/*
1375 	 * Now that we are completely done shutting down the
1376 	 * superblock, we need to actually destroy the kobject.
1377 	 */
1378 	kobject_put(&sbi->s_kobj);
1379 	wait_for_completion(&sbi->s_kobj_unregister);
1380 	kfree(sbi->s_blockgroup_lock);
1381 	fs_put_dax(sbi->s_daxdev, NULL);
1382 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1383 #if IS_ENABLED(CONFIG_UNICODE)
1384 	utf8_unload(sb->s_encoding);
1385 #endif
1386 	kfree(sbi);
1387 }
1388 
1389 static struct kmem_cache *ext4_inode_cachep;
1390 
1391 /*
1392  * Called inside transaction, so use GFP_NOFS
1393  */
1394 static struct inode *ext4_alloc_inode(struct super_block *sb)
1395 {
1396 	struct ext4_inode_info *ei;
1397 
1398 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1399 	if (!ei)
1400 		return NULL;
1401 
1402 	inode_set_iversion(&ei->vfs_inode, 1);
1403 	ei->i_flags = 0;
1404 	ext4_clear_state_flags(ei);	/* Only relevant on 32-bit archs */
1405 	spin_lock_init(&ei->i_raw_lock);
1406 	ei->i_prealloc_node = RB_ROOT;
1407 	atomic_set(&ei->i_prealloc_active, 0);
1408 	rwlock_init(&ei->i_prealloc_lock);
1409 	ext4_es_init_tree(&ei->i_es_tree);
1410 	rwlock_init(&ei->i_es_lock);
1411 	INIT_LIST_HEAD(&ei->i_es_list);
1412 	ei->i_es_all_nr = 0;
1413 	ei->i_es_shk_nr = 0;
1414 	ei->i_es_shrink_lblk = 0;
1415 	ei->i_es_seq = 0;
1416 	ei->i_reserved_data_blocks = 0;
1417 	spin_lock_init(&(ei->i_block_reservation_lock));
1418 	ext4_init_pending_tree(&ei->i_pending_tree);
1419 #ifdef CONFIG_QUOTA
1420 	ei->i_reserved_quota = 0;
1421 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1422 #endif
1423 	ei->jinode = NULL;
1424 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1425 	spin_lock_init(&ei->i_completed_io_lock);
1426 	ei->i_sync_tid = 0;
1427 	ei->i_datasync_tid = 0;
1428 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1429 	ext4_fc_init_inode(&ei->vfs_inode);
1430 	spin_lock_init(&ei->i_fc_lock);
1431 	return &ei->vfs_inode;
1432 }
1433 
1434 static int ext4_drop_inode(struct inode *inode)
1435 {
1436 	int drop = inode_generic_drop(inode);
1437 
1438 	if (!drop)
1439 		drop = fscrypt_drop_inode(inode);
1440 
1441 	trace_ext4_drop_inode(inode, drop);
1442 	return drop;
1443 }
1444 
1445 static void ext4_free_in_core_inode(struct inode *inode)
1446 {
1447 	fscrypt_free_inode(inode);
1448 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1449 		pr_warn("%s: inode %ld still in fc list",
1450 			__func__, inode->i_ino);
1451 	}
1452 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1453 }
1454 
1455 static void ext4_destroy_inode(struct inode *inode)
1456 {
1457 	if (ext4_inode_orphan_tracked(inode)) {
1458 		ext4_msg(inode->i_sb, KERN_ERR,
1459 			 "Inode %lu (%p): inode tracked as orphan!",
1460 			 inode->i_ino, EXT4_I(inode));
1461 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1462 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1463 				true);
1464 		dump_stack();
1465 	}
1466 
1467 	if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
1468 	    WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
1469 		ext4_msg(inode->i_sb, KERN_ERR,
1470 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1471 			 inode->i_ino, EXT4_I(inode),
1472 			 EXT4_I(inode)->i_reserved_data_blocks);
1473 }
1474 
1475 static void ext4_shutdown(struct super_block *sb)
1476 {
1477        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1478 }
1479 
1480 static void init_once(void *foo)
1481 {
1482 	struct ext4_inode_info *ei = foo;
1483 
1484 	INIT_LIST_HEAD(&ei->i_orphan);
1485 	init_rwsem(&ei->xattr_sem);
1486 	init_rwsem(&ei->i_data_sem);
1487 	inode_init_once(&ei->vfs_inode);
1488 	ext4_fc_init_inode(&ei->vfs_inode);
1489 #ifdef CONFIG_FS_ENCRYPTION
1490 	ei->i_crypt_info = NULL;
1491 #endif
1492 }
1493 
1494 static int __init init_inodecache(void)
1495 {
1496 	struct kmem_cache_args args = {
1497 		.useroffset = offsetof(struct ext4_inode_info, i_data),
1498 		.usersize = sizeof_field(struct ext4_inode_info, i_data),
1499 		.use_freeptr_offset = true,
1500 		.freeptr_offset = offsetof(struct ext4_inode_info, i_flags),
1501 		.ctor = init_once,
1502 	};
1503 
1504 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1505 				sizeof(struct ext4_inode_info),
1506 				&args,
1507 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT);
1508 
1509 	if (ext4_inode_cachep == NULL)
1510 		return -ENOMEM;
1511 	return 0;
1512 }
1513 
1514 static void destroy_inodecache(void)
1515 {
1516 	/*
1517 	 * Make sure all delayed rcu free inodes are flushed before we
1518 	 * destroy cache.
1519 	 */
1520 	rcu_barrier();
1521 	kmem_cache_destroy(ext4_inode_cachep);
1522 }
1523 
1524 void ext4_clear_inode(struct inode *inode)
1525 {
1526 	ext4_fc_del(inode);
1527 	invalidate_inode_buffers(inode);
1528 	clear_inode(inode);
1529 	ext4_discard_preallocations(inode);
1530 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1531 	dquot_drop(inode);
1532 	if (EXT4_I(inode)->jinode) {
1533 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1534 					       EXT4_I(inode)->jinode);
1535 		jbd2_free_inode(EXT4_I(inode)->jinode);
1536 		EXT4_I(inode)->jinode = NULL;
1537 	}
1538 	fscrypt_put_encryption_info(inode);
1539 }
1540 
1541 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1542 					u64 ino, u32 generation)
1543 {
1544 	struct inode *inode;
1545 
1546 	/*
1547 	 * Currently we don't know the generation for parent directory, so
1548 	 * a generation of 0 means "accept any"
1549 	 */
1550 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1551 	if (IS_ERR(inode))
1552 		return ERR_CAST(inode);
1553 	if (generation && inode->i_generation != generation) {
1554 		iput(inode);
1555 		return ERR_PTR(-ESTALE);
1556 	}
1557 
1558 	return inode;
1559 }
1560 
1561 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1562 					int fh_len, int fh_type)
1563 {
1564 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1565 				    ext4_nfs_get_inode);
1566 }
1567 
1568 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1569 					int fh_len, int fh_type)
1570 {
1571 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1572 				    ext4_nfs_get_inode);
1573 }
1574 
1575 static int ext4_nfs_commit_metadata(struct inode *inode)
1576 {
1577 	struct writeback_control wbc = {
1578 		.sync_mode = WB_SYNC_ALL
1579 	};
1580 
1581 	trace_ext4_nfs_commit_metadata(inode);
1582 	return ext4_write_inode(inode, &wbc);
1583 }
1584 
1585 #ifdef CONFIG_QUOTA
1586 static const char * const quotatypes[] = INITQFNAMES;
1587 #define QTYPE2NAME(t) (quotatypes[t])
1588 
1589 static int ext4_write_dquot(struct dquot *dquot);
1590 static int ext4_acquire_dquot(struct dquot *dquot);
1591 static int ext4_release_dquot(struct dquot *dquot);
1592 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1593 static int ext4_write_info(struct super_block *sb, int type);
1594 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1595 			 const struct path *path);
1596 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1597 			       size_t len, loff_t off);
1598 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1599 				const char *data, size_t len, loff_t off);
1600 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1601 			     unsigned int flags);
1602 
1603 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1604 {
1605 	return EXT4_I(inode)->i_dquot;
1606 }
1607 
1608 static const struct dquot_operations ext4_quota_operations = {
1609 	.get_reserved_space	= ext4_get_reserved_space,
1610 	.write_dquot		= ext4_write_dquot,
1611 	.acquire_dquot		= ext4_acquire_dquot,
1612 	.release_dquot		= ext4_release_dquot,
1613 	.mark_dirty		= ext4_mark_dquot_dirty,
1614 	.write_info		= ext4_write_info,
1615 	.alloc_dquot		= dquot_alloc,
1616 	.destroy_dquot		= dquot_destroy,
1617 	.get_projid		= ext4_get_projid,
1618 	.get_inode_usage	= ext4_get_inode_usage,
1619 	.get_next_id		= dquot_get_next_id,
1620 };
1621 
1622 static const struct quotactl_ops ext4_qctl_operations = {
1623 	.quota_on	= ext4_quota_on,
1624 	.quota_off	= ext4_quota_off,
1625 	.quota_sync	= dquot_quota_sync,
1626 	.get_state	= dquot_get_state,
1627 	.set_info	= dquot_set_dqinfo,
1628 	.get_dqblk	= dquot_get_dqblk,
1629 	.set_dqblk	= dquot_set_dqblk,
1630 	.get_nextdqblk	= dquot_get_next_dqblk,
1631 };
1632 #endif
1633 
1634 static const struct super_operations ext4_sops = {
1635 	.alloc_inode	= ext4_alloc_inode,
1636 	.free_inode	= ext4_free_in_core_inode,
1637 	.destroy_inode	= ext4_destroy_inode,
1638 	.write_inode	= ext4_write_inode,
1639 	.dirty_inode	= ext4_dirty_inode,
1640 	.drop_inode	= ext4_drop_inode,
1641 	.evict_inode	= ext4_evict_inode,
1642 	.put_super	= ext4_put_super,
1643 	.sync_fs	= ext4_sync_fs,
1644 	.freeze_fs	= ext4_freeze,
1645 	.unfreeze_fs	= ext4_unfreeze,
1646 	.statfs		= ext4_statfs,
1647 	.show_options	= ext4_show_options,
1648 	.shutdown	= ext4_shutdown,
1649 #ifdef CONFIG_QUOTA
1650 	.quota_read	= ext4_quota_read,
1651 	.quota_write	= ext4_quota_write,
1652 	.get_dquots	= ext4_get_dquots,
1653 #endif
1654 };
1655 
1656 static const struct export_operations ext4_export_ops = {
1657 	.encode_fh = generic_encode_ino32_fh,
1658 	.fh_to_dentry = ext4_fh_to_dentry,
1659 	.fh_to_parent = ext4_fh_to_parent,
1660 	.get_parent = ext4_get_parent,
1661 	.commit_metadata = ext4_nfs_commit_metadata,
1662 };
1663 
1664 enum {
1665 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1666 	Opt_resgid, Opt_resuid, Opt_sb,
1667 	Opt_nouid32, Opt_debug, Opt_removed,
1668 	Opt_user_xattr, Opt_acl,
1669 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1670 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1671 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1672 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1673 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1674 	Opt_inlinecrypt,
1675 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1676 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1677 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1678 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1679 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1680 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1681 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1682 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1683 	Opt_dioread_nolock, Opt_dioread_lock,
1684 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1685 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1686 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1687 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1688 #ifdef CONFIG_EXT4_DEBUG
1689 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1690 #endif
1691 };
1692 
1693 static const struct constant_table ext4_param_errors[] = {
1694 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1695 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1696 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1697 	{}
1698 };
1699 
1700 static const struct constant_table ext4_param_data[] = {
1701 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1702 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1703 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1704 	{}
1705 };
1706 
1707 static const struct constant_table ext4_param_data_err[] = {
1708 	{"abort",	Opt_data_err_abort},
1709 	{"ignore",	Opt_data_err_ignore},
1710 	{}
1711 };
1712 
1713 static const struct constant_table ext4_param_jqfmt[] = {
1714 	{"vfsold",	QFMT_VFS_OLD},
1715 	{"vfsv0",	QFMT_VFS_V0},
1716 	{"vfsv1",	QFMT_VFS_V1},
1717 	{}
1718 };
1719 
1720 static const struct constant_table ext4_param_dax[] = {
1721 	{"always",	Opt_dax_always},
1722 	{"inode",	Opt_dax_inode},
1723 	{"never",	Opt_dax_never},
1724 	{}
1725 };
1726 
1727 /*
1728  * Mount option specification
1729  * We don't use fsparam_flag_no because of the way we set the
1730  * options and the way we show them in _ext4_show_options(). To
1731  * keep the changes to a minimum, let's keep the negative options
1732  * separate for now.
1733  */
1734 static const struct fs_parameter_spec ext4_param_specs[] = {
1735 	fsparam_flag	("bsddf",		Opt_bsd_df),
1736 	fsparam_flag	("minixdf",		Opt_minix_df),
1737 	fsparam_flag	("grpid",		Opt_grpid),
1738 	fsparam_flag	("bsdgroups",		Opt_grpid),
1739 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1740 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1741 	fsparam_gid	("resgid",		Opt_resgid),
1742 	fsparam_uid	("resuid",		Opt_resuid),
1743 	fsparam_u32	("sb",			Opt_sb),
1744 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1745 	fsparam_flag	("nouid32",		Opt_nouid32),
1746 	fsparam_flag	("debug",		Opt_debug),
1747 	fsparam_flag	("oldalloc",		Opt_removed),
1748 	fsparam_flag	("orlov",		Opt_removed),
1749 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1750 	fsparam_flag	("acl",			Opt_acl),
1751 	fsparam_flag	("norecovery",		Opt_noload),
1752 	fsparam_flag	("noload",		Opt_noload),
1753 	fsparam_flag	("bh",			Opt_removed),
1754 	fsparam_flag	("nobh",		Opt_removed),
1755 	fsparam_u32	("commit",		Opt_commit),
1756 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1757 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1758 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1759 	fsparam_bdev	("journal_path",	Opt_journal_path),
1760 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1761 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1762 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1763 	fsparam_flag	("abort",		Opt_abort),
1764 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1765 	fsparam_enum	("data_err",		Opt_data_err,
1766 						ext4_param_data_err),
1767 	fsparam_string_empty
1768 			("usrjquota",		Opt_usrjquota),
1769 	fsparam_string_empty
1770 			("grpjquota",		Opt_grpjquota),
1771 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1772 	fsparam_flag	("grpquota",		Opt_grpquota),
1773 	fsparam_flag	("quota",		Opt_quota),
1774 	fsparam_flag	("noquota",		Opt_noquota),
1775 	fsparam_flag	("usrquota",		Opt_usrquota),
1776 	fsparam_flag	("prjquota",		Opt_prjquota),
1777 	fsparam_flag	("barrier",		Opt_barrier),
1778 	fsparam_u32	("barrier",		Opt_barrier),
1779 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1780 	fsparam_flag	("i_version",		Opt_removed),
1781 	fsparam_flag	("dax",			Opt_dax),
1782 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1783 	fsparam_u32	("stripe",		Opt_stripe),
1784 	fsparam_flag	("delalloc",		Opt_delalloc),
1785 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1786 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1787 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1788 	fsparam_u32	("debug_want_extra_isize",
1789 						Opt_debug_want_extra_isize),
1790 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1791 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1792 	fsparam_flag	("block_validity",	Opt_block_validity),
1793 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1794 	fsparam_u32	("inode_readahead_blks",
1795 						Opt_inode_readahead_blks),
1796 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1797 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1798 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1799 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1800 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1801 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1802 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1803 	fsparam_flag	("discard",		Opt_discard),
1804 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1805 	fsparam_u32	("init_itable",		Opt_init_itable),
1806 	fsparam_flag	("init_itable",		Opt_init_itable),
1807 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1808 #ifdef CONFIG_EXT4_DEBUG
1809 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1810 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1811 #endif
1812 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1813 	fsparam_flag	("test_dummy_encryption",
1814 						Opt_test_dummy_encryption),
1815 	fsparam_string	("test_dummy_encryption",
1816 						Opt_test_dummy_encryption),
1817 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1818 	fsparam_flag	("nombcache",		Opt_nombcache),
1819 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1820 	fsparam_flag	("prefetch_block_bitmaps",
1821 						Opt_removed),
1822 	fsparam_flag	("no_prefetch_block_bitmaps",
1823 						Opt_no_prefetch_block_bitmaps),
1824 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1825 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1826 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1827 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1828 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1829 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1830 	{}
1831 };
1832 
1833 
1834 #define MOPT_SET	0x0001
1835 #define MOPT_CLEAR	0x0002
1836 #define MOPT_NOSUPPORT	0x0004
1837 #define MOPT_EXPLICIT	0x0008
1838 #ifdef CONFIG_QUOTA
1839 #define MOPT_Q		0
1840 #define MOPT_QFMT	0x0010
1841 #else
1842 #define MOPT_Q		MOPT_NOSUPPORT
1843 #define MOPT_QFMT	MOPT_NOSUPPORT
1844 #endif
1845 #define MOPT_NO_EXT2	0x0020
1846 #define MOPT_NO_EXT3	0x0040
1847 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1848 #define MOPT_SKIP	0x0080
1849 #define	MOPT_2		0x0100
1850 
1851 static const struct mount_opts {
1852 	int	token;
1853 	int	mount_opt;
1854 	int	flags;
1855 } ext4_mount_opts[] = {
1856 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1857 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1858 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1859 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1860 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1861 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1862 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1863 	 MOPT_EXT4_ONLY | MOPT_SET},
1864 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1865 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1866 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1867 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1868 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1869 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1870 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1871 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1872 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1873 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1874 	{Opt_commit, 0, MOPT_NO_EXT2},
1875 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1876 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1877 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1878 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1879 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1880 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1881 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1882 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1883 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1884 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1885 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1886 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1887 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1888 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1889 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1890 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1891 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1892 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1893 	{Opt_data, 0, MOPT_NO_EXT2},
1894 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1895 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1896 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1897 #else
1898 	{Opt_acl, 0, MOPT_NOSUPPORT},
1899 #endif
1900 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1901 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1902 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1903 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1904 							MOPT_SET | MOPT_Q},
1905 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1906 							MOPT_SET | MOPT_Q},
1907 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1908 							MOPT_SET | MOPT_Q},
1909 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1910 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1911 							MOPT_CLEAR | MOPT_Q},
1912 	{Opt_usrjquota, 0, MOPT_Q},
1913 	{Opt_grpjquota, 0, MOPT_Q},
1914 	{Opt_jqfmt, 0, MOPT_QFMT},
1915 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1916 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1917 	 MOPT_SET},
1918 #ifdef CONFIG_EXT4_DEBUG
1919 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1920 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1921 #endif
1922 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1923 	{Opt_err, 0, 0}
1924 };
1925 
1926 #if IS_ENABLED(CONFIG_UNICODE)
1927 static const struct ext4_sb_encodings {
1928 	__u16 magic;
1929 	char *name;
1930 	unsigned int version;
1931 } ext4_sb_encoding_map[] = {
1932 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1933 };
1934 
1935 static const struct ext4_sb_encodings *
1936 ext4_sb_read_encoding(const struct ext4_super_block *es)
1937 {
1938 	__u16 magic = le16_to_cpu(es->s_encoding);
1939 	int i;
1940 
1941 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1942 		if (magic == ext4_sb_encoding_map[i].magic)
1943 			return &ext4_sb_encoding_map[i];
1944 
1945 	return NULL;
1946 }
1947 #endif
1948 
1949 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1950 #define EXT4_SPEC_JQFMT				(1 <<  1)
1951 #define EXT4_SPEC_DATAJ				(1 <<  2)
1952 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1953 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1954 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1955 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1956 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1957 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1958 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1959 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1960 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1961 #define EXT4_SPEC_s_stripe			(1 << 13)
1962 #define EXT4_SPEC_s_resuid			(1 << 14)
1963 #define EXT4_SPEC_s_resgid			(1 << 15)
1964 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1965 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1966 #define EXT4_SPEC_s_sb_block			(1 << 18)
1967 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1968 
1969 struct ext4_fs_context {
1970 	char		*s_qf_names[EXT4_MAXQUOTAS];
1971 	struct fscrypt_dummy_policy dummy_enc_policy;
1972 	int		s_jquota_fmt;	/* Format of quota to use */
1973 #ifdef CONFIG_EXT4_DEBUG
1974 	int s_fc_debug_max_replay;
1975 #endif
1976 	unsigned short	qname_spec;
1977 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1978 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1979 	unsigned long	journal_devnum;
1980 	unsigned long	s_commit_interval;
1981 	unsigned long	s_stripe;
1982 	unsigned int	s_inode_readahead_blks;
1983 	unsigned int	s_want_extra_isize;
1984 	unsigned int	s_li_wait_mult;
1985 	unsigned int	s_max_dir_size_kb;
1986 	unsigned int	journal_ioprio;
1987 	unsigned int	vals_s_mount_opt;
1988 	unsigned int	mask_s_mount_opt;
1989 	unsigned int	vals_s_mount_opt2;
1990 	unsigned int	mask_s_mount_opt2;
1991 	unsigned int	opt_flags;	/* MOPT flags */
1992 	unsigned int	spec;
1993 	u32		s_max_batch_time;
1994 	u32		s_min_batch_time;
1995 	kuid_t		s_resuid;
1996 	kgid_t		s_resgid;
1997 	ext4_fsblk_t	s_sb_block;
1998 };
1999 
2000 static void ext4_fc_free(struct fs_context *fc)
2001 {
2002 	struct ext4_fs_context *ctx = fc->fs_private;
2003 	int i;
2004 
2005 	if (!ctx)
2006 		return;
2007 
2008 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2009 		kfree(ctx->s_qf_names[i]);
2010 
2011 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2012 	kfree(ctx);
2013 }
2014 
2015 int ext4_init_fs_context(struct fs_context *fc)
2016 {
2017 	struct ext4_fs_context *ctx;
2018 
2019 	ctx = kzalloc_obj(struct ext4_fs_context, GFP_KERNEL);
2020 	if (!ctx)
2021 		return -ENOMEM;
2022 
2023 	fc->fs_private = ctx;
2024 	fc->ops = &ext4_context_ops;
2025 
2026 	/* i_version is always enabled now */
2027 	fc->sb_flags |= SB_I_VERSION;
2028 
2029 	return 0;
2030 }
2031 
2032 #ifdef CONFIG_QUOTA
2033 /*
2034  * Note the name of the specified quota file.
2035  */
2036 static int note_qf_name(struct fs_context *fc, int qtype,
2037 		       struct fs_parameter *param)
2038 {
2039 	struct ext4_fs_context *ctx = fc->fs_private;
2040 	char *qname;
2041 
2042 	if (param->size < 1) {
2043 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2044 		return -EINVAL;
2045 	}
2046 	if (strchr(param->string, '/')) {
2047 		ext4_msg(NULL, KERN_ERR,
2048 			 "quotafile must be on filesystem root");
2049 		return -EINVAL;
2050 	}
2051 	if (ctx->s_qf_names[qtype]) {
2052 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2053 			ext4_msg(NULL, KERN_ERR,
2054 				 "%s quota file already specified",
2055 				 QTYPE2NAME(qtype));
2056 			return -EINVAL;
2057 		}
2058 		return 0;
2059 	}
2060 
2061 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2062 	if (!qname) {
2063 		ext4_msg(NULL, KERN_ERR,
2064 			 "Not enough memory for storing quotafile name");
2065 		return -ENOMEM;
2066 	}
2067 	ctx->s_qf_names[qtype] = qname;
2068 	ctx->qname_spec |= 1 << qtype;
2069 	ctx->spec |= EXT4_SPEC_JQUOTA;
2070 	return 0;
2071 }
2072 
2073 /*
2074  * Clear the name of the specified quota file.
2075  */
2076 static int unnote_qf_name(struct fs_context *fc, int qtype)
2077 {
2078 	struct ext4_fs_context *ctx = fc->fs_private;
2079 
2080 	kfree(ctx->s_qf_names[qtype]);
2081 
2082 	ctx->s_qf_names[qtype] = NULL;
2083 	ctx->qname_spec |= 1 << qtype;
2084 	ctx->spec |= EXT4_SPEC_JQUOTA;
2085 	return 0;
2086 }
2087 #endif
2088 
2089 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2090 					    struct ext4_fs_context *ctx)
2091 {
2092 	int err;
2093 
2094 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2095 		ext4_msg(NULL, KERN_WARNING,
2096 			 "test_dummy_encryption option not supported");
2097 		return -EINVAL;
2098 	}
2099 	err = fscrypt_parse_test_dummy_encryption(param,
2100 						  &ctx->dummy_enc_policy);
2101 	if (err == -EINVAL) {
2102 		ext4_msg(NULL, KERN_WARNING,
2103 			 "Value of option \"%s\" is unrecognized", param->key);
2104 	} else if (err == -EEXIST) {
2105 		ext4_msg(NULL, KERN_WARNING,
2106 			 "Conflicting test_dummy_encryption options");
2107 		return -EINVAL;
2108 	}
2109 	return err;
2110 }
2111 
2112 #define EXT4_SET_CTX(name)						\
2113 static inline __maybe_unused						\
2114 void ctx_set_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2115 {									\
2116 	ctx->mask_s_##name |= flag;					\
2117 	ctx->vals_s_##name |= flag;					\
2118 }
2119 
2120 #define EXT4_CLEAR_CTX(name)						\
2121 static inline __maybe_unused						\
2122 void ctx_clear_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2123 {									\
2124 	ctx->mask_s_##name |= flag;					\
2125 	ctx->vals_s_##name &= ~flag;					\
2126 }
2127 
2128 #define EXT4_TEST_CTX(name)						\
2129 static inline unsigned long						\
2130 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2131 {									\
2132 	return (ctx->vals_s_##name & flag);				\
2133 }
2134 
2135 EXT4_SET_CTX(flags); /* set only */
2136 EXT4_SET_CTX(mount_opt);
2137 EXT4_CLEAR_CTX(mount_opt);
2138 EXT4_TEST_CTX(mount_opt);
2139 EXT4_SET_CTX(mount_opt2);
2140 EXT4_CLEAR_CTX(mount_opt2);
2141 EXT4_TEST_CTX(mount_opt2);
2142 
2143 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2144 {
2145 	struct ext4_fs_context *ctx = fc->fs_private;
2146 	struct fs_parse_result result;
2147 	const struct mount_opts *m;
2148 	int is_remount;
2149 	int token;
2150 
2151 	token = fs_parse(fc, ext4_param_specs, param, &result);
2152 	if (token < 0)
2153 		return token;
2154 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2155 
2156 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2157 		if (token == m->token)
2158 			break;
2159 
2160 	ctx->opt_flags |= m->flags;
2161 
2162 	if (m->flags & MOPT_EXPLICIT) {
2163 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2164 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2165 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2166 			ctx_set_mount_opt2(ctx,
2167 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2168 		} else
2169 			return -EINVAL;
2170 	}
2171 
2172 	if (m->flags & MOPT_NOSUPPORT) {
2173 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2174 			 param->key);
2175 		return 0;
2176 	}
2177 
2178 	switch (token) {
2179 #ifdef CONFIG_QUOTA
2180 	case Opt_usrjquota:
2181 		if (!*param->string)
2182 			return unnote_qf_name(fc, USRQUOTA);
2183 		else
2184 			return note_qf_name(fc, USRQUOTA, param);
2185 	case Opt_grpjquota:
2186 		if (!*param->string)
2187 			return unnote_qf_name(fc, GRPQUOTA);
2188 		else
2189 			return note_qf_name(fc, GRPQUOTA, param);
2190 #endif
2191 	case Opt_sb:
2192 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2193 			ext4_msg(NULL, KERN_WARNING,
2194 				 "Ignoring %s option on remount", param->key);
2195 		} else {
2196 			ctx->s_sb_block = result.uint_32;
2197 			ctx->spec |= EXT4_SPEC_s_sb_block;
2198 		}
2199 		return 0;
2200 	case Opt_removed:
2201 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2202 			 param->key);
2203 		return 0;
2204 	case Opt_inlinecrypt:
2205 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2206 		ctx_set_flags(ctx, SB_INLINECRYPT);
2207 #else
2208 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2209 #endif
2210 		return 0;
2211 	case Opt_errors:
2212 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2213 		ctx_set_mount_opt(ctx, result.uint_32);
2214 		return 0;
2215 #ifdef CONFIG_QUOTA
2216 	case Opt_jqfmt:
2217 		ctx->s_jquota_fmt = result.uint_32;
2218 		ctx->spec |= EXT4_SPEC_JQFMT;
2219 		return 0;
2220 #endif
2221 	case Opt_data:
2222 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2223 		ctx_set_mount_opt(ctx, result.uint_32);
2224 		ctx->spec |= EXT4_SPEC_DATAJ;
2225 		return 0;
2226 	case Opt_commit:
2227 		if (result.uint_32 == 0)
2228 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2229 		else if (result.uint_32 > INT_MAX / HZ) {
2230 			ext4_msg(NULL, KERN_ERR,
2231 				 "Invalid commit interval %d, "
2232 				 "must be smaller than %d",
2233 				 result.uint_32, INT_MAX / HZ);
2234 			return -EINVAL;
2235 		}
2236 		ctx->s_commit_interval = HZ * result.uint_32;
2237 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2238 		return 0;
2239 	case Opt_debug_want_extra_isize:
2240 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2241 			ext4_msg(NULL, KERN_ERR,
2242 				 "Invalid want_extra_isize %d", result.uint_32);
2243 			return -EINVAL;
2244 		}
2245 		ctx->s_want_extra_isize = result.uint_32;
2246 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2247 		return 0;
2248 	case Opt_max_batch_time:
2249 		ctx->s_max_batch_time = result.uint_32;
2250 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2251 		return 0;
2252 	case Opt_min_batch_time:
2253 		ctx->s_min_batch_time = result.uint_32;
2254 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2255 		return 0;
2256 	case Opt_inode_readahead_blks:
2257 		if (result.uint_32 &&
2258 		    (result.uint_32 > (1 << 30) ||
2259 		     !is_power_of_2(result.uint_32))) {
2260 			ext4_msg(NULL, KERN_ERR,
2261 				 "EXT4-fs: inode_readahead_blks must be "
2262 				 "0 or a power of 2 smaller than 2^31");
2263 			return -EINVAL;
2264 		}
2265 		ctx->s_inode_readahead_blks = result.uint_32;
2266 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2267 		return 0;
2268 	case Opt_init_itable:
2269 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2270 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2271 		if (param->type == fs_value_is_string)
2272 			ctx->s_li_wait_mult = result.uint_32;
2273 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2274 		return 0;
2275 	case Opt_max_dir_size_kb:
2276 		ctx->s_max_dir_size_kb = result.uint_32;
2277 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2278 		return 0;
2279 #ifdef CONFIG_EXT4_DEBUG
2280 	case Opt_fc_debug_max_replay:
2281 		ctx->s_fc_debug_max_replay = result.uint_32;
2282 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2283 		return 0;
2284 #endif
2285 	case Opt_stripe:
2286 		ctx->s_stripe = result.uint_32;
2287 		ctx->spec |= EXT4_SPEC_s_stripe;
2288 		return 0;
2289 	case Opt_resuid:
2290 		ctx->s_resuid = result.uid;
2291 		ctx->spec |= EXT4_SPEC_s_resuid;
2292 		return 0;
2293 	case Opt_resgid:
2294 		ctx->s_resgid = result.gid;
2295 		ctx->spec |= EXT4_SPEC_s_resgid;
2296 		return 0;
2297 	case Opt_journal_dev:
2298 		if (is_remount) {
2299 			ext4_msg(NULL, KERN_ERR,
2300 				 "Cannot specify journal on remount");
2301 			return -EINVAL;
2302 		}
2303 		ctx->journal_devnum = result.uint_32;
2304 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2305 		return 0;
2306 	case Opt_journal_path:
2307 	{
2308 		struct inode *journal_inode;
2309 		struct path path;
2310 		int error;
2311 
2312 		if (is_remount) {
2313 			ext4_msg(NULL, KERN_ERR,
2314 				 "Cannot specify journal on remount");
2315 			return -EINVAL;
2316 		}
2317 
2318 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2319 		if (error) {
2320 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2321 				 "journal device path");
2322 			return -EINVAL;
2323 		}
2324 
2325 		journal_inode = d_inode(path.dentry);
2326 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2327 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2328 		path_put(&path);
2329 		return 0;
2330 	}
2331 	case Opt_journal_ioprio:
2332 		if (result.uint_32 > 7) {
2333 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2334 				 " (must be 0-7)");
2335 			return -EINVAL;
2336 		}
2337 		ctx->journal_ioprio =
2338 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2339 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2340 		return 0;
2341 	case Opt_test_dummy_encryption:
2342 		return ext4_parse_test_dummy_encryption(param, ctx);
2343 	case Opt_dax:
2344 	case Opt_dax_type:
2345 #ifdef CONFIG_FS_DAX
2346 	{
2347 		int type = (token == Opt_dax) ?
2348 			   Opt_dax : result.uint_32;
2349 
2350 		switch (type) {
2351 		case Opt_dax:
2352 		case Opt_dax_always:
2353 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2354 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2355 			break;
2356 		case Opt_dax_never:
2357 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2358 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2359 			break;
2360 		case Opt_dax_inode:
2361 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2362 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2363 			/* Strictly for printing options */
2364 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2365 			break;
2366 		}
2367 		return 0;
2368 	}
2369 #else
2370 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2371 		return -EINVAL;
2372 #endif
2373 	case Opt_data_err:
2374 		if (result.uint_32 == Opt_data_err_abort)
2375 			ctx_set_mount_opt(ctx, m->mount_opt);
2376 		else if (result.uint_32 == Opt_data_err_ignore)
2377 			ctx_clear_mount_opt(ctx, m->mount_opt);
2378 		return 0;
2379 	case Opt_mb_optimize_scan:
2380 		if (result.int_32 == 1) {
2381 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2382 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2383 		} else if (result.int_32 == 0) {
2384 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2385 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2386 		} else {
2387 			ext4_msg(NULL, KERN_WARNING,
2388 				 "mb_optimize_scan should be set to 0 or 1.");
2389 			return -EINVAL;
2390 		}
2391 		return 0;
2392 	}
2393 
2394 	/*
2395 	 * At this point we should only be getting options requiring MOPT_SET,
2396 	 * or MOPT_CLEAR. Anything else is a bug
2397 	 */
2398 	if (m->token == Opt_err) {
2399 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2400 			 param->key);
2401 		WARN_ON(1);
2402 		return -EINVAL;
2403 	}
2404 
2405 	else {
2406 		unsigned int set = 0;
2407 
2408 		if ((param->type == fs_value_is_flag) ||
2409 		    result.uint_32 > 0)
2410 			set = 1;
2411 
2412 		if (m->flags & MOPT_CLEAR)
2413 			set = !set;
2414 		else if (unlikely(!(m->flags & MOPT_SET))) {
2415 			ext4_msg(NULL, KERN_WARNING,
2416 				 "buggy handling of option %s",
2417 				 param->key);
2418 			WARN_ON(1);
2419 			return -EINVAL;
2420 		}
2421 		if (m->flags & MOPT_2) {
2422 			if (set != 0)
2423 				ctx_set_mount_opt2(ctx, m->mount_opt);
2424 			else
2425 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2426 		} else {
2427 			if (set != 0)
2428 				ctx_set_mount_opt(ctx, m->mount_opt);
2429 			else
2430 				ctx_clear_mount_opt(ctx, m->mount_opt);
2431 		}
2432 	}
2433 
2434 	return 0;
2435 }
2436 
2437 static int parse_options(struct fs_context *fc, char *options)
2438 {
2439 	struct fs_parameter param;
2440 	int ret;
2441 	char *key;
2442 
2443 	if (!options)
2444 		return 0;
2445 
2446 	while ((key = strsep(&options, ",")) != NULL) {
2447 		if (*key) {
2448 			size_t v_len = 0;
2449 			char *value = strchr(key, '=');
2450 
2451 			param.type = fs_value_is_flag;
2452 			param.string = NULL;
2453 
2454 			if (value) {
2455 				if (value == key)
2456 					continue;
2457 
2458 				*value++ = 0;
2459 				v_len = strlen(value);
2460 				param.string = kmemdup_nul(value, v_len,
2461 							   GFP_KERNEL);
2462 				if (!param.string)
2463 					return -ENOMEM;
2464 				param.type = fs_value_is_string;
2465 			}
2466 
2467 			param.key = key;
2468 			param.size = v_len;
2469 
2470 			ret = ext4_parse_param(fc, &param);
2471 			kfree(param.string);
2472 			if (ret < 0)
2473 				return ret;
2474 		}
2475 	}
2476 
2477 	ret = ext4_validate_options(fc);
2478 	if (ret < 0)
2479 		return ret;
2480 
2481 	return 0;
2482 }
2483 
2484 static int parse_apply_sb_mount_options(struct super_block *sb,
2485 					struct ext4_fs_context *m_ctx)
2486 {
2487 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2488 	char s_mount_opts[64];
2489 	struct ext4_fs_context *s_ctx = NULL;
2490 	struct fs_context *fc = NULL;
2491 	int ret = -ENOMEM;
2492 
2493 	if (!sbi->s_es->s_mount_opts[0])
2494 		return 0;
2495 
2496 	if (strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts) < 0)
2497 		return -E2BIG;
2498 
2499 	fc = kzalloc_obj(struct fs_context, GFP_KERNEL);
2500 	if (!fc)
2501 		return -ENOMEM;
2502 
2503 	s_ctx = kzalloc_obj(struct ext4_fs_context, GFP_KERNEL);
2504 	if (!s_ctx)
2505 		goto out_free;
2506 
2507 	fc->fs_private = s_ctx;
2508 	fc->s_fs_info = sbi;
2509 
2510 	ret = parse_options(fc, s_mount_opts);
2511 	if (ret < 0)
2512 		goto parse_failed;
2513 
2514 	ret = ext4_check_opt_consistency(fc, sb);
2515 	if (ret < 0) {
2516 parse_failed:
2517 		ext4_msg(sb, KERN_WARNING,
2518 			 "failed to parse options in superblock: %s",
2519 			 s_mount_opts);
2520 		ret = 0;
2521 		goto out_free;
2522 	}
2523 
2524 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2525 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2526 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2527 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2528 
2529 	ext4_apply_options(fc, sb);
2530 	ret = 0;
2531 
2532 out_free:
2533 	ext4_fc_free(fc);
2534 	kfree(fc);
2535 	return ret;
2536 }
2537 
2538 static void ext4_apply_quota_options(struct fs_context *fc,
2539 				     struct super_block *sb)
2540 {
2541 #ifdef CONFIG_QUOTA
2542 	bool quota_feature = ext4_has_feature_quota(sb);
2543 	struct ext4_fs_context *ctx = fc->fs_private;
2544 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2545 	char *qname;
2546 	int i;
2547 
2548 	if (quota_feature)
2549 		return;
2550 
2551 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2552 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2553 			if (!(ctx->qname_spec & (1 << i)))
2554 				continue;
2555 
2556 			qname = ctx->s_qf_names[i]; /* May be NULL */
2557 			if (qname)
2558 				set_opt(sb, QUOTA);
2559 			ctx->s_qf_names[i] = NULL;
2560 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2561 						lockdep_is_held(&sb->s_umount));
2562 			if (qname)
2563 				kfree_rcu_mightsleep(qname);
2564 		}
2565 	}
2566 
2567 	if (ctx->spec & EXT4_SPEC_JQFMT)
2568 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2569 #endif
2570 }
2571 
2572 /*
2573  * Check quota settings consistency.
2574  */
2575 static int ext4_check_quota_consistency(struct fs_context *fc,
2576 					struct super_block *sb)
2577 {
2578 #ifdef CONFIG_QUOTA
2579 	struct ext4_fs_context *ctx = fc->fs_private;
2580 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2581 	bool quota_feature = ext4_has_feature_quota(sb);
2582 	bool quota_loaded = sb_any_quota_loaded(sb);
2583 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2584 	int quota_flags, i;
2585 
2586 	/*
2587 	 * We do the test below only for project quotas. 'usrquota' and
2588 	 * 'grpquota' mount options are allowed even without quota feature
2589 	 * to support legacy quotas in quota files.
2590 	 */
2591 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2592 	    !ext4_has_feature_project(sb)) {
2593 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2594 			 "Cannot enable project quota enforcement.");
2595 		return -EINVAL;
2596 	}
2597 
2598 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2599 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2600 	if (quota_loaded &&
2601 	    ctx->mask_s_mount_opt & quota_flags &&
2602 	    !ctx_test_mount_opt(ctx, quota_flags))
2603 		goto err_quota_change;
2604 
2605 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2606 
2607 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2608 			if (!(ctx->qname_spec & (1 << i)))
2609 				continue;
2610 
2611 			if (quota_loaded &&
2612 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2613 				goto err_jquota_change;
2614 
2615 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2616 			    strcmp(get_qf_name(sb, sbi, i),
2617 				   ctx->s_qf_names[i]) != 0)
2618 				goto err_jquota_specified;
2619 		}
2620 
2621 		if (quota_feature) {
2622 			ext4_msg(NULL, KERN_INFO,
2623 				 "Journaled quota options ignored when "
2624 				 "QUOTA feature is enabled");
2625 			return 0;
2626 		}
2627 	}
2628 
2629 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2630 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2631 			goto err_jquota_change;
2632 		if (quota_feature) {
2633 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2634 				 "ignored when QUOTA feature is enabled");
2635 			return 0;
2636 		}
2637 	}
2638 
2639 	/* Make sure we don't mix old and new quota format */
2640 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2641 		       ctx->s_qf_names[USRQUOTA]);
2642 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2643 		       ctx->s_qf_names[GRPQUOTA]);
2644 
2645 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2646 		    test_opt(sb, USRQUOTA));
2647 
2648 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2649 		    test_opt(sb, GRPQUOTA));
2650 
2651 	if (usr_qf_name) {
2652 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2653 		usrquota = false;
2654 	}
2655 	if (grp_qf_name) {
2656 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2657 		grpquota = false;
2658 	}
2659 
2660 	if (usr_qf_name || grp_qf_name) {
2661 		if (usrquota || grpquota) {
2662 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2663 				 "format mixing");
2664 			return -EINVAL;
2665 		}
2666 
2667 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2668 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2669 				 "not specified");
2670 			return -EINVAL;
2671 		}
2672 	}
2673 
2674 	return 0;
2675 
2676 err_quota_change:
2677 	ext4_msg(NULL, KERN_ERR,
2678 		 "Cannot change quota options when quota turned on");
2679 	return -EINVAL;
2680 err_jquota_change:
2681 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2682 		 "options when quota turned on");
2683 	return -EINVAL;
2684 err_jquota_specified:
2685 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2686 		 QTYPE2NAME(i));
2687 	return -EINVAL;
2688 #else
2689 	return 0;
2690 #endif
2691 }
2692 
2693 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2694 					    struct super_block *sb)
2695 {
2696 	const struct ext4_fs_context *ctx = fc->fs_private;
2697 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2698 
2699 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2700 		return 0;
2701 
2702 	if (!ext4_has_feature_encrypt(sb)) {
2703 		ext4_msg(NULL, KERN_WARNING,
2704 			 "test_dummy_encryption requires encrypt feature");
2705 		return -EINVAL;
2706 	}
2707 	/*
2708 	 * This mount option is just for testing, and it's not worthwhile to
2709 	 * implement the extra complexity (e.g. RCU protection) that would be
2710 	 * needed to allow it to be set or changed during remount.  We do allow
2711 	 * it to be specified during remount, but only if there is no change.
2712 	 */
2713 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2714 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2715 						 &ctx->dummy_enc_policy))
2716 			return 0;
2717 		ext4_msg(NULL, KERN_WARNING,
2718 			 "Can't set or change test_dummy_encryption on remount");
2719 		return -EINVAL;
2720 	}
2721 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2722 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2723 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2724 						 &ctx->dummy_enc_policy))
2725 			return 0;
2726 		ext4_msg(NULL, KERN_WARNING,
2727 			 "Conflicting test_dummy_encryption options");
2728 		return -EINVAL;
2729 	}
2730 	return 0;
2731 }
2732 
2733 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2734 					     struct super_block *sb)
2735 {
2736 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2737 	    /* if already set, it was already verified to be the same */
2738 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2739 		return;
2740 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2741 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2742 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2743 }
2744 
2745 static int ext4_check_opt_consistency(struct fs_context *fc,
2746 				      struct super_block *sb)
2747 {
2748 	struct ext4_fs_context *ctx = fc->fs_private;
2749 	struct ext4_sb_info *sbi = fc->s_fs_info;
2750 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2751 	int err;
2752 
2753 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2754 		ext4_msg(NULL, KERN_ERR,
2755 			 "Mount option(s) incompatible with ext2");
2756 		return -EINVAL;
2757 	}
2758 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2759 		ext4_msg(NULL, KERN_ERR,
2760 			 "Mount option(s) incompatible with ext3");
2761 		return -EINVAL;
2762 	}
2763 
2764 	if (ctx->s_want_extra_isize >
2765 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2766 		ext4_msg(NULL, KERN_ERR,
2767 			 "Invalid want_extra_isize %d",
2768 			 ctx->s_want_extra_isize);
2769 		return -EINVAL;
2770 	}
2771 
2772 	err = ext4_check_test_dummy_encryption(fc, sb);
2773 	if (err)
2774 		return err;
2775 
2776 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2777 		if (!sbi->s_journal) {
2778 			ext4_msg(NULL, KERN_WARNING,
2779 				 "Remounting file system with no journal "
2780 				 "so ignoring journalled data option");
2781 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2782 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2783 			   test_opt(sb, DATA_FLAGS)) {
2784 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2785 				 "on remount");
2786 			return -EINVAL;
2787 		}
2788 	}
2789 
2790 	if (is_remount) {
2791 		if (!sbi->s_journal &&
2792 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT)) {
2793 			ext4_msg(NULL, KERN_WARNING,
2794 				 "Remounting fs w/o journal so ignoring data_err option");
2795 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT);
2796 		}
2797 
2798 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2799 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2800 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2801 				 "both data=journal and dax");
2802 			return -EINVAL;
2803 		}
2804 
2805 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2806 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2807 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2808 fail_dax_change_remount:
2809 			ext4_msg(NULL, KERN_ERR, "can't change "
2810 				 "dax mount option while remounting");
2811 			return -EINVAL;
2812 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2813 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2814 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2815 			goto fail_dax_change_remount;
2816 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2817 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2818 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2819 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2820 			goto fail_dax_change_remount;
2821 		}
2822 	}
2823 
2824 	return ext4_check_quota_consistency(fc, sb);
2825 }
2826 
2827 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2828 {
2829 	struct ext4_fs_context *ctx = fc->fs_private;
2830 	struct ext4_sb_info *sbi = fc->s_fs_info;
2831 
2832 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2833 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2834 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2835 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2836 	sb->s_flags &= ~ctx->mask_s_flags;
2837 	sb->s_flags |= ctx->vals_s_flags;
2838 
2839 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2840 	APPLY(s_commit_interval);
2841 	APPLY(s_stripe);
2842 	APPLY(s_max_batch_time);
2843 	APPLY(s_min_batch_time);
2844 	APPLY(s_want_extra_isize);
2845 	APPLY(s_inode_readahead_blks);
2846 	APPLY(s_max_dir_size_kb);
2847 	APPLY(s_li_wait_mult);
2848 	APPLY(s_resgid);
2849 	APPLY(s_resuid);
2850 
2851 #ifdef CONFIG_EXT4_DEBUG
2852 	APPLY(s_fc_debug_max_replay);
2853 #endif
2854 
2855 	ext4_apply_quota_options(fc, sb);
2856 	ext4_apply_test_dummy_encryption(ctx, sb);
2857 }
2858 
2859 
2860 static int ext4_validate_options(struct fs_context *fc)
2861 {
2862 #ifdef CONFIG_QUOTA
2863 	struct ext4_fs_context *ctx = fc->fs_private;
2864 	char *usr_qf_name, *grp_qf_name;
2865 
2866 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2867 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2868 
2869 	if (usr_qf_name || grp_qf_name) {
2870 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2871 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2872 
2873 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2874 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2875 
2876 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2877 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2878 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2879 				 "format mixing");
2880 			return -EINVAL;
2881 		}
2882 	}
2883 #endif
2884 	return 1;
2885 }
2886 
2887 static inline void ext4_show_quota_options(struct seq_file *seq,
2888 					   struct super_block *sb)
2889 {
2890 #if defined(CONFIG_QUOTA)
2891 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2892 	char *usr_qf_name, *grp_qf_name;
2893 
2894 	if (sbi->s_jquota_fmt) {
2895 		char *fmtname = "";
2896 
2897 		switch (sbi->s_jquota_fmt) {
2898 		case QFMT_VFS_OLD:
2899 			fmtname = "vfsold";
2900 			break;
2901 		case QFMT_VFS_V0:
2902 			fmtname = "vfsv0";
2903 			break;
2904 		case QFMT_VFS_V1:
2905 			fmtname = "vfsv1";
2906 			break;
2907 		}
2908 		seq_printf(seq, ",jqfmt=%s", fmtname);
2909 	}
2910 
2911 	rcu_read_lock();
2912 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2913 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2914 	if (usr_qf_name)
2915 		seq_show_option(seq, "usrjquota", usr_qf_name);
2916 	if (grp_qf_name)
2917 		seq_show_option(seq, "grpjquota", grp_qf_name);
2918 	rcu_read_unlock();
2919 #endif
2920 }
2921 
2922 static const char *token2str(int token)
2923 {
2924 	const struct fs_parameter_spec *spec;
2925 
2926 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2927 		if (spec->opt == token && !spec->type)
2928 			break;
2929 	return spec->name;
2930 }
2931 
2932 /*
2933  * Show an option if
2934  *  - it's set to a non-default value OR
2935  *  - if the per-sb default is different from the global default
2936  */
2937 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2938 			      int nodefs)
2939 {
2940 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2941 	struct ext4_super_block *es = sbi->s_es;
2942 	int def_errors;
2943 	const struct mount_opts *m;
2944 	char sep = nodefs ? '\n' : ',';
2945 
2946 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2947 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2948 
2949 	if (sbi->s_sb_block != 1)
2950 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2951 
2952 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2953 		int want_set = m->flags & MOPT_SET;
2954 		int opt_2 = m->flags & MOPT_2;
2955 		unsigned int mount_opt, def_mount_opt;
2956 
2957 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2958 		    m->flags & MOPT_SKIP)
2959 			continue;
2960 
2961 		if (opt_2) {
2962 			mount_opt = sbi->s_mount_opt2;
2963 			def_mount_opt = sbi->s_def_mount_opt2;
2964 		} else {
2965 			mount_opt = sbi->s_mount_opt;
2966 			def_mount_opt = sbi->s_def_mount_opt;
2967 		}
2968 		/* skip if same as the default */
2969 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2970 			continue;
2971 		/* select Opt_noFoo vs Opt_Foo */
2972 		if ((want_set &&
2973 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2974 		    (!want_set && (mount_opt & m->mount_opt)))
2975 			continue;
2976 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2977 	}
2978 
2979 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2980 	    ext4_get_resuid(es) != EXT4_DEF_RESUID)
2981 		SEQ_OPTS_PRINT("resuid=%u",
2982 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2983 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2984 	    ext4_get_resgid(es) != EXT4_DEF_RESGID)
2985 		SEQ_OPTS_PRINT("resgid=%u",
2986 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2987 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2988 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2989 		SEQ_OPTS_PUTS("errors=remount-ro");
2990 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2991 		SEQ_OPTS_PUTS("errors=continue");
2992 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2993 		SEQ_OPTS_PUTS("errors=panic");
2994 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2995 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2996 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2997 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2998 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2999 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3000 	if (nodefs && sb->s_flags & SB_I_VERSION)
3001 		SEQ_OPTS_PUTS("i_version");
3002 	if (nodefs || sbi->s_stripe)
3003 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3004 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3005 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3006 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3007 			SEQ_OPTS_PUTS("data=journal");
3008 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3009 			SEQ_OPTS_PUTS("data=ordered");
3010 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3011 			SEQ_OPTS_PUTS("data=writeback");
3012 	}
3013 	if (nodefs ||
3014 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3015 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3016 			       sbi->s_inode_readahead_blks);
3017 
3018 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3019 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3020 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3021 	if (nodefs || sbi->s_max_dir_size_kb)
3022 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3023 	if (test_opt(sb, DATA_ERR_ABORT))
3024 		SEQ_OPTS_PUTS("data_err=abort");
3025 
3026 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3027 
3028 	if (sb->s_flags & SB_INLINECRYPT)
3029 		SEQ_OPTS_PUTS("inlinecrypt");
3030 
3031 	if (test_opt(sb, DAX_ALWAYS)) {
3032 		if (IS_EXT2_SB(sb))
3033 			SEQ_OPTS_PUTS("dax");
3034 		else
3035 			SEQ_OPTS_PUTS("dax=always");
3036 	} else if (test_opt2(sb, DAX_NEVER)) {
3037 		SEQ_OPTS_PUTS("dax=never");
3038 	} else if (test_opt2(sb, DAX_INODE)) {
3039 		SEQ_OPTS_PUTS("dax=inode");
3040 	}
3041 
3042 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3043 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3044 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3045 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3046 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3047 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3048 	}
3049 
3050 	if (nodefs && !test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS))
3051 		SEQ_OPTS_PUTS("prefetch_block_bitmaps");
3052 
3053 	if (ext4_emergency_ro(sb))
3054 		SEQ_OPTS_PUTS("emergency_ro");
3055 
3056 	if (ext4_forced_shutdown(sb))
3057 		SEQ_OPTS_PUTS("shutdown");
3058 
3059 	ext4_show_quota_options(seq, sb);
3060 	return 0;
3061 }
3062 
3063 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3064 {
3065 	return _ext4_show_options(seq, root->d_sb, 0);
3066 }
3067 
3068 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3069 {
3070 	struct super_block *sb = seq->private;
3071 	int rc;
3072 
3073 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3074 	rc = _ext4_show_options(seq, sb, 1);
3075 	seq_putc(seq, '\n');
3076 	return rc;
3077 }
3078 
3079 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3080 			    int read_only)
3081 {
3082 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3083 	int err = 0;
3084 
3085 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3086 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3087 			 "forcing read-only mode");
3088 		err = -EROFS;
3089 		goto done;
3090 	}
3091 	if (read_only)
3092 		goto done;
3093 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3094 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3095 			 "running e2fsck is recommended");
3096 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3097 		ext4_msg(sb, KERN_WARNING,
3098 			 "warning: mounting fs with errors, "
3099 			 "running e2fsck is recommended");
3100 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3101 		 le16_to_cpu(es->s_mnt_count) >=
3102 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3103 		ext4_msg(sb, KERN_WARNING,
3104 			 "warning: maximal mount count reached, "
3105 			 "running e2fsck is recommended");
3106 	else if (le32_to_cpu(es->s_checkinterval) &&
3107 		 (ext4_get_tstamp(es, s_lastcheck) +
3108 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3109 		ext4_msg(sb, KERN_WARNING,
3110 			 "warning: checktime reached, "
3111 			 "running e2fsck is recommended");
3112 	if (!sbi->s_journal)
3113 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3114 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3115 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3116 	le16_add_cpu(&es->s_mnt_count, 1);
3117 	ext4_update_tstamp(es, s_mtime);
3118 	if (sbi->s_journal) {
3119 		ext4_set_feature_journal_needs_recovery(sb);
3120 		if (ext4_has_feature_orphan_file(sb))
3121 			ext4_set_feature_orphan_present(sb);
3122 	}
3123 
3124 	err = ext4_commit_super(sb);
3125 done:
3126 	if (test_opt(sb, DEBUG))
3127 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3128 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3129 			sb->s_blocksize,
3130 			sbi->s_groups_count,
3131 			EXT4_BLOCKS_PER_GROUP(sb),
3132 			EXT4_INODES_PER_GROUP(sb),
3133 			sbi->s_mount_opt, sbi->s_mount_opt2);
3134 	return err;
3135 }
3136 
3137 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3138 {
3139 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3140 	struct flex_groups **old_groups, **new_groups;
3141 	int size, i, j;
3142 
3143 	if (!sbi->s_log_groups_per_flex)
3144 		return 0;
3145 
3146 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3147 	if (size <= sbi->s_flex_groups_allocated)
3148 		return 0;
3149 
3150 	new_groups = kvzalloc(roundup_pow_of_two(size *
3151 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3152 	if (!new_groups) {
3153 		ext4_msg(sb, KERN_ERR,
3154 			 "not enough memory for %d flex group pointers", size);
3155 		return -ENOMEM;
3156 	}
3157 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3158 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3159 					 sizeof(struct flex_groups)),
3160 					 GFP_KERNEL);
3161 		if (!new_groups[i]) {
3162 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3163 				kvfree(new_groups[j]);
3164 			kvfree(new_groups);
3165 			ext4_msg(sb, KERN_ERR,
3166 				 "not enough memory for %d flex groups", size);
3167 			return -ENOMEM;
3168 		}
3169 	}
3170 	rcu_read_lock();
3171 	old_groups = rcu_dereference(sbi->s_flex_groups);
3172 	if (old_groups)
3173 		memcpy(new_groups, old_groups,
3174 		       (sbi->s_flex_groups_allocated *
3175 			sizeof(struct flex_groups *)));
3176 	rcu_read_unlock();
3177 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3178 	sbi->s_flex_groups_allocated = size;
3179 	if (old_groups)
3180 		ext4_kvfree_array_rcu(old_groups);
3181 	return 0;
3182 }
3183 
3184 static int ext4_fill_flex_info(struct super_block *sb)
3185 {
3186 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3187 	struct ext4_group_desc *gdp = NULL;
3188 	struct flex_groups *fg;
3189 	ext4_group_t flex_group;
3190 	int i, err;
3191 
3192 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3193 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3194 		sbi->s_log_groups_per_flex = 0;
3195 		return 1;
3196 	}
3197 
3198 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3199 	if (err)
3200 		goto failed;
3201 
3202 	for (i = 0; i < sbi->s_groups_count; i++) {
3203 		gdp = ext4_get_group_desc(sb, i, NULL);
3204 
3205 		flex_group = ext4_flex_group(sbi, i);
3206 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3207 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3208 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3209 			     &fg->free_clusters);
3210 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3211 	}
3212 
3213 	return 1;
3214 failed:
3215 	return 0;
3216 }
3217 
3218 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3219 				   struct ext4_group_desc *gdp)
3220 {
3221 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3222 	__u16 crc = 0;
3223 	__le32 le_group = cpu_to_le32(block_group);
3224 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3225 
3226 	if (ext4_has_feature_metadata_csum(sbi->s_sb)) {
3227 		/* Use new metadata_csum algorithm */
3228 		__u32 csum32;
3229 		__u16 dummy_csum = 0;
3230 
3231 		csum32 = ext4_chksum(sbi->s_csum_seed, (__u8 *)&le_group,
3232 				     sizeof(le_group));
3233 		csum32 = ext4_chksum(csum32, (__u8 *)gdp, offset);
3234 		csum32 = ext4_chksum(csum32, (__u8 *)&dummy_csum,
3235 				     sizeof(dummy_csum));
3236 		offset += sizeof(dummy_csum);
3237 		if (offset < sbi->s_desc_size)
3238 			csum32 = ext4_chksum(csum32, (__u8 *)gdp + offset,
3239 					     sbi->s_desc_size - offset);
3240 
3241 		crc = csum32 & 0xFFFF;
3242 		goto out;
3243 	}
3244 
3245 	/* old crc16 code */
3246 	if (!ext4_has_feature_gdt_csum(sb))
3247 		return 0;
3248 
3249 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3250 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3251 	crc = crc16(crc, (__u8 *)gdp, offset);
3252 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3253 	/* for checksum of struct ext4_group_desc do the rest...*/
3254 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3255 		crc = crc16(crc, (__u8 *)gdp + offset,
3256 			    sbi->s_desc_size - offset);
3257 
3258 out:
3259 	return cpu_to_le16(crc);
3260 }
3261 
3262 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3263 				struct ext4_group_desc *gdp)
3264 {
3265 	if (ext4_has_group_desc_csum(sb) &&
3266 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3267 		return 0;
3268 
3269 	return 1;
3270 }
3271 
3272 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3273 			      struct ext4_group_desc *gdp)
3274 {
3275 	if (!ext4_has_group_desc_csum(sb))
3276 		return;
3277 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3278 }
3279 
3280 /* Called at mount-time, super-block is locked */
3281 static int ext4_check_descriptors(struct super_block *sb,
3282 				  ext4_fsblk_t sb_block,
3283 				  ext4_group_t *first_not_zeroed)
3284 {
3285 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3286 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3287 	ext4_fsblk_t last_block;
3288 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3289 	ext4_fsblk_t block_bitmap;
3290 	ext4_fsblk_t inode_bitmap;
3291 	ext4_fsblk_t inode_table;
3292 	int flexbg_flag = 0;
3293 	ext4_group_t i, grp = sbi->s_groups_count;
3294 
3295 	if (ext4_has_feature_flex_bg(sb))
3296 		flexbg_flag = 1;
3297 
3298 	ext4_debug("Checking group descriptors");
3299 
3300 	for (i = 0; i < sbi->s_groups_count; i++) {
3301 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3302 
3303 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3304 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3305 		else
3306 			last_block = first_block +
3307 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3308 
3309 		if ((grp == sbi->s_groups_count) &&
3310 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3311 			grp = i;
3312 
3313 		block_bitmap = ext4_block_bitmap(sb, gdp);
3314 		if (block_bitmap == sb_block) {
3315 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3316 				 "Block bitmap for group %u overlaps "
3317 				 "superblock", i);
3318 			if (!sb_rdonly(sb))
3319 				return 0;
3320 		}
3321 		if (block_bitmap >= sb_block + 1 &&
3322 		    block_bitmap <= last_bg_block) {
3323 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3324 				 "Block bitmap for group %u overlaps "
3325 				 "block group descriptors", i);
3326 			if (!sb_rdonly(sb))
3327 				return 0;
3328 		}
3329 		if (block_bitmap < first_block || block_bitmap > last_block) {
3330 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3331 			       "Block bitmap for group %u not in group "
3332 			       "(block %llu)!", i, block_bitmap);
3333 			return 0;
3334 		}
3335 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3336 		if (inode_bitmap == sb_block) {
3337 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3338 				 "Inode bitmap for group %u overlaps "
3339 				 "superblock", i);
3340 			if (!sb_rdonly(sb))
3341 				return 0;
3342 		}
3343 		if (inode_bitmap >= sb_block + 1 &&
3344 		    inode_bitmap <= last_bg_block) {
3345 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3346 				 "Inode bitmap for group %u overlaps "
3347 				 "block group descriptors", i);
3348 			if (!sb_rdonly(sb))
3349 				return 0;
3350 		}
3351 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3352 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3353 			       "Inode bitmap for group %u not in group "
3354 			       "(block %llu)!", i, inode_bitmap);
3355 			return 0;
3356 		}
3357 		inode_table = ext4_inode_table(sb, gdp);
3358 		if (inode_table == sb_block) {
3359 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3360 				 "Inode table for group %u overlaps "
3361 				 "superblock", i);
3362 			if (!sb_rdonly(sb))
3363 				return 0;
3364 		}
3365 		if (inode_table >= sb_block + 1 &&
3366 		    inode_table <= last_bg_block) {
3367 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3368 				 "Inode table for group %u overlaps "
3369 				 "block group descriptors", i);
3370 			if (!sb_rdonly(sb))
3371 				return 0;
3372 		}
3373 		if (inode_table < first_block ||
3374 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3375 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3376 			       "Inode table for group %u not in group "
3377 			       "(block %llu)!", i, inode_table);
3378 			return 0;
3379 		}
3380 		ext4_lock_group(sb, i);
3381 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3382 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3383 				 "Checksum for group %u failed (%u!=%u)",
3384 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3385 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3386 			if (!sb_rdonly(sb)) {
3387 				ext4_unlock_group(sb, i);
3388 				return 0;
3389 			}
3390 		}
3391 		ext4_unlock_group(sb, i);
3392 		if (!flexbg_flag)
3393 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3394 	}
3395 	if (NULL != first_not_zeroed)
3396 		*first_not_zeroed = grp;
3397 	return 1;
3398 }
3399 
3400 /*
3401  * Maximal extent format file size.
3402  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3403  * extent format containers, within a sector_t, and within i_blocks
3404  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3405  * so that won't be a limiting factor.
3406  *
3407  * However there is other limiting factor. We do store extents in the form
3408  * of starting block and length, hence the resulting length of the extent
3409  * covering maximum file size must fit into on-disk format containers as
3410  * well. Given that length is always by 1 unit bigger than max unit (because
3411  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3412  *
3413  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3414  */
3415 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3416 {
3417 	loff_t res;
3418 	loff_t upper_limit = MAX_LFS_FILESIZE;
3419 
3420 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3421 
3422 	if (!has_huge_files) {
3423 		upper_limit = (1LL << 32) - 1;
3424 
3425 		/* total blocks in file system block size */
3426 		upper_limit >>= (blkbits - 9);
3427 		upper_limit <<= blkbits;
3428 	}
3429 
3430 	/*
3431 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3432 	 * by one fs block, so ee_len can cover the extent of maximum file
3433 	 * size
3434 	 */
3435 	res = (1LL << 32) - 1;
3436 	res <<= blkbits;
3437 
3438 	/* Sanity check against vm- & vfs- imposed limits */
3439 	if (res > upper_limit)
3440 		res = upper_limit;
3441 
3442 	return res;
3443 }
3444 
3445 /*
3446  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3447  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3448  * We need to be 1 filesystem block less than the 2^48 sector limit.
3449  */
3450 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3451 {
3452 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3453 	int meta_blocks;
3454 	unsigned int ppb = 1 << (bits - 2);
3455 
3456 	/*
3457 	 * This is calculated to be the largest file size for a dense, block
3458 	 * mapped file such that the file's total number of 512-byte sectors,
3459 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3460 	 *
3461 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3462 	 * number of 512-byte sectors of the file.
3463 	 */
3464 	if (!has_huge_files) {
3465 		/*
3466 		 * !has_huge_files or implies that the inode i_block field
3467 		 * represents total file blocks in 2^32 512-byte sectors ==
3468 		 * size of vfs inode i_blocks * 8
3469 		 */
3470 		upper_limit = (1LL << 32) - 1;
3471 
3472 		/* total blocks in file system block size */
3473 		upper_limit >>= (bits - 9);
3474 
3475 	} else {
3476 		/*
3477 		 * We use 48 bit ext4_inode i_blocks
3478 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3479 		 * represent total number of blocks in
3480 		 * file system block size
3481 		 */
3482 		upper_limit = (1LL << 48) - 1;
3483 
3484 	}
3485 
3486 	/* Compute how many blocks we can address by block tree */
3487 	res += ppb;
3488 	res += ppb * ppb;
3489 	res += ((loff_t)ppb) * ppb * ppb;
3490 	/* Compute how many metadata blocks are needed */
3491 	meta_blocks = 1;
3492 	meta_blocks += 1 + ppb;
3493 	meta_blocks += 1 + ppb + ppb * ppb;
3494 	/* Does block tree limit file size? */
3495 	if (res + meta_blocks <= upper_limit)
3496 		goto check_lfs;
3497 
3498 	res = upper_limit;
3499 	/* How many metadata blocks are needed for addressing upper_limit? */
3500 	upper_limit -= EXT4_NDIR_BLOCKS;
3501 	/* indirect blocks */
3502 	meta_blocks = 1;
3503 	upper_limit -= ppb;
3504 	/* double indirect blocks */
3505 	if (upper_limit < ppb * ppb) {
3506 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3507 		res -= meta_blocks;
3508 		goto check_lfs;
3509 	}
3510 	meta_blocks += 1 + ppb;
3511 	upper_limit -= ppb * ppb;
3512 	/* tripple indirect blocks for the rest */
3513 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3514 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3515 	res -= meta_blocks;
3516 check_lfs:
3517 	res <<= bits;
3518 	if (res > MAX_LFS_FILESIZE)
3519 		res = MAX_LFS_FILESIZE;
3520 
3521 	return res;
3522 }
3523 
3524 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3525 				   ext4_fsblk_t logical_sb_block, int nr)
3526 {
3527 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3528 	ext4_group_t bg, first_meta_bg;
3529 	int has_super = 0;
3530 
3531 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3532 
3533 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3534 		return logical_sb_block + nr + 1;
3535 	bg = sbi->s_desc_per_block * nr;
3536 	if (ext4_bg_has_super(sb, bg))
3537 		has_super = 1;
3538 
3539 	/*
3540 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3541 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3542 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3543 	 * compensate.
3544 	 */
3545 	if (sb->s_blocksize == 1024 && nr == 0 &&
3546 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3547 		has_super++;
3548 
3549 	return (has_super + ext4_group_first_block_no(sb, bg));
3550 }
3551 
3552 /**
3553  * ext4_get_stripe_size: Get the stripe size.
3554  * @sbi: In memory super block info
3555  *
3556  * If we have specified it via mount option, then
3557  * use the mount option value. If the value specified at mount time is
3558  * greater than the blocks per group use the super block value.
3559  * If the super block value is greater than blocks per group return 0.
3560  * Allocator needs it be less than blocks per group.
3561  *
3562  */
3563 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3564 {
3565 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3566 	unsigned long stripe_width =
3567 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3568 	int ret;
3569 
3570 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3571 		ret = sbi->s_stripe;
3572 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3573 		ret = stripe_width;
3574 	else if (stride && stride <= sbi->s_blocks_per_group)
3575 		ret = stride;
3576 	else
3577 		ret = 0;
3578 
3579 	/*
3580 	 * If the stripe width is 1, this makes no sense and
3581 	 * we set it to 0 to turn off stripe handling code.
3582 	 */
3583 	if (ret <= 1)
3584 		ret = 0;
3585 
3586 	return ret;
3587 }
3588 
3589 /*
3590  * Check whether this filesystem can be mounted based on
3591  * the features present and the RDONLY/RDWR mount requested.
3592  * Returns 1 if this filesystem can be mounted as requested,
3593  * 0 if it cannot be.
3594  */
3595 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3596 {
3597 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3598 		ext4_msg(sb, KERN_ERR,
3599 			"Couldn't mount because of "
3600 			"unsupported optional features (%x)",
3601 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3602 			~EXT4_FEATURE_INCOMPAT_SUPP));
3603 		return 0;
3604 	}
3605 
3606 	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
3607 		ext4_msg(sb, KERN_ERR,
3608 			 "Filesystem with casefold feature cannot be "
3609 			 "mounted without CONFIG_UNICODE");
3610 		return 0;
3611 	}
3612 
3613 	if (readonly)
3614 		return 1;
3615 
3616 	if (ext4_has_feature_readonly(sb)) {
3617 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3618 		sb->s_flags |= SB_RDONLY;
3619 		return 1;
3620 	}
3621 
3622 	/* Check that feature set is OK for a read-write mount */
3623 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3624 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3625 			 "unsupported optional features (%x)",
3626 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3627 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3628 		return 0;
3629 	}
3630 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3631 		ext4_msg(sb, KERN_ERR,
3632 			 "Can't support bigalloc feature without "
3633 			 "extents feature\n");
3634 		return 0;
3635 	}
3636 
3637 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3638 	if (!readonly && (ext4_has_feature_quota(sb) ||
3639 			  ext4_has_feature_project(sb))) {
3640 		ext4_msg(sb, KERN_ERR,
3641 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3642 		return 0;
3643 	}
3644 #endif  /* CONFIG_QUOTA */
3645 	return 1;
3646 }
3647 
3648 /*
3649  * This function is called once a day by default if we have errors logged
3650  * on the file system.
3651  * Use the err_report_sec sysfs attribute to disable or adjust its call
3652  * freequency.
3653  */
3654 void print_daily_error_info(struct timer_list *t)
3655 {
3656 	struct ext4_sb_info *sbi = timer_container_of(sbi, t, s_err_report);
3657 	struct super_block *sb = sbi->s_sb;
3658 	struct ext4_super_block *es = sbi->s_es;
3659 
3660 	if (es->s_error_count)
3661 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3662 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3663 			 le32_to_cpu(es->s_error_count));
3664 	if (es->s_first_error_time) {
3665 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3666 		       sb->s_id,
3667 		       ext4_get_tstamp(es, s_first_error_time),
3668 		       (int) sizeof(es->s_first_error_func),
3669 		       es->s_first_error_func,
3670 		       le32_to_cpu(es->s_first_error_line));
3671 		if (es->s_first_error_ino)
3672 			printk(KERN_CONT ": inode %u",
3673 			       le32_to_cpu(es->s_first_error_ino));
3674 		if (es->s_first_error_block)
3675 			printk(KERN_CONT ": block %llu", (unsigned long long)
3676 			       le64_to_cpu(es->s_first_error_block));
3677 		printk(KERN_CONT "\n");
3678 	}
3679 	if (es->s_last_error_time) {
3680 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3681 		       sb->s_id,
3682 		       ext4_get_tstamp(es, s_last_error_time),
3683 		       (int) sizeof(es->s_last_error_func),
3684 		       es->s_last_error_func,
3685 		       le32_to_cpu(es->s_last_error_line));
3686 		if (es->s_last_error_ino)
3687 			printk(KERN_CONT ": inode %u",
3688 			       le32_to_cpu(es->s_last_error_ino));
3689 		if (es->s_last_error_block)
3690 			printk(KERN_CONT ": block %llu", (unsigned long long)
3691 			       le64_to_cpu(es->s_last_error_block));
3692 		printk(KERN_CONT "\n");
3693 	}
3694 
3695 	if (sbi->s_err_report_sec)
3696 		mod_timer(&sbi->s_err_report, jiffies + secs_to_jiffies(sbi->s_err_report_sec));
3697 }
3698 
3699 /* Find next suitable group and run ext4_init_inode_table */
3700 static int ext4_run_li_request(struct ext4_li_request *elr)
3701 {
3702 	struct ext4_group_desc *gdp = NULL;
3703 	struct super_block *sb = elr->lr_super;
3704 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3705 	ext4_group_t group = elr->lr_next_group;
3706 	unsigned int prefetch_ios = 0;
3707 	int ret = 0;
3708 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3709 	u64 start_time;
3710 
3711 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3712 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3713 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3714 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3715 		if (group >= elr->lr_next_group) {
3716 			ret = 1;
3717 			if (elr->lr_first_not_zeroed != ngroups &&
3718 			    !ext4_emergency_state(sb) && !sb_rdonly(sb) &&
3719 			    test_opt(sb, INIT_INODE_TABLE)) {
3720 				elr->lr_next_group = elr->lr_first_not_zeroed;
3721 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3722 				ret = 0;
3723 			}
3724 		}
3725 		return ret;
3726 	}
3727 
3728 	for (; group < ngroups; group++) {
3729 		gdp = ext4_get_group_desc(sb, group, NULL);
3730 		if (!gdp) {
3731 			ret = 1;
3732 			break;
3733 		}
3734 
3735 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3736 			break;
3737 	}
3738 
3739 	if (group >= ngroups)
3740 		ret = 1;
3741 
3742 	if (!ret) {
3743 		start_time = ktime_get_ns();
3744 		ret = ext4_init_inode_table(sb, group,
3745 					    elr->lr_timeout ? 0 : 1);
3746 		trace_ext4_lazy_itable_init(sb, group);
3747 		if (elr->lr_timeout == 0) {
3748 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_ns() - start_time) *
3749 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3750 		}
3751 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3752 		elr->lr_next_group = group + 1;
3753 	}
3754 	return ret;
3755 }
3756 
3757 /*
3758  * Remove lr_request from the list_request and free the
3759  * request structure. Should be called with li_list_mtx held
3760  */
3761 static void ext4_remove_li_request(struct ext4_li_request *elr)
3762 {
3763 	if (!elr)
3764 		return;
3765 
3766 	list_del(&elr->lr_request);
3767 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3768 	kfree(elr);
3769 }
3770 
3771 static void ext4_unregister_li_request(struct super_block *sb)
3772 {
3773 	mutex_lock(&ext4_li_mtx);
3774 	if (!ext4_li_info) {
3775 		mutex_unlock(&ext4_li_mtx);
3776 		return;
3777 	}
3778 
3779 	mutex_lock(&ext4_li_info->li_list_mtx);
3780 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3781 	mutex_unlock(&ext4_li_info->li_list_mtx);
3782 	mutex_unlock(&ext4_li_mtx);
3783 }
3784 
3785 static struct task_struct *ext4_lazyinit_task;
3786 
3787 /*
3788  * This is the function where ext4lazyinit thread lives. It walks
3789  * through the request list searching for next scheduled filesystem.
3790  * When such a fs is found, run the lazy initialization request
3791  * (ext4_rn_li_request) and keep track of the time spend in this
3792  * function. Based on that time we compute next schedule time of
3793  * the request. When walking through the list is complete, compute
3794  * next waking time and put itself into sleep.
3795  */
3796 static int ext4_lazyinit_thread(void *arg)
3797 {
3798 	struct ext4_lazy_init *eli = arg;
3799 	struct list_head *pos, *n;
3800 	struct ext4_li_request *elr;
3801 	unsigned long next_wakeup, cur;
3802 
3803 	BUG_ON(NULL == eli);
3804 	set_freezable();
3805 
3806 cont_thread:
3807 	while (true) {
3808 		bool next_wakeup_initialized = false;
3809 
3810 		next_wakeup = 0;
3811 		mutex_lock(&eli->li_list_mtx);
3812 		if (list_empty(&eli->li_request_list)) {
3813 			mutex_unlock(&eli->li_list_mtx);
3814 			goto exit_thread;
3815 		}
3816 		list_for_each_safe(pos, n, &eli->li_request_list) {
3817 			int err = 0;
3818 			int progress = 0;
3819 			elr = list_entry(pos, struct ext4_li_request,
3820 					 lr_request);
3821 
3822 			if (time_before(jiffies, elr->lr_next_sched)) {
3823 				if (!next_wakeup_initialized ||
3824 				    time_before(elr->lr_next_sched, next_wakeup)) {
3825 					next_wakeup = elr->lr_next_sched;
3826 					next_wakeup_initialized = true;
3827 				}
3828 				continue;
3829 			}
3830 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3831 				if (sb_start_write_trylock(elr->lr_super)) {
3832 					progress = 1;
3833 					/*
3834 					 * We hold sb->s_umount, sb can not
3835 					 * be removed from the list, it is
3836 					 * now safe to drop li_list_mtx
3837 					 */
3838 					mutex_unlock(&eli->li_list_mtx);
3839 					err = ext4_run_li_request(elr);
3840 					sb_end_write(elr->lr_super);
3841 					mutex_lock(&eli->li_list_mtx);
3842 					n = pos->next;
3843 				}
3844 				up_read((&elr->lr_super->s_umount));
3845 			}
3846 			/* error, remove the lazy_init job */
3847 			if (err) {
3848 				ext4_remove_li_request(elr);
3849 				continue;
3850 			}
3851 			if (!progress) {
3852 				elr->lr_next_sched = jiffies +
3853 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3854 			}
3855 			if (!next_wakeup_initialized ||
3856 			    time_before(elr->lr_next_sched, next_wakeup)) {
3857 				next_wakeup = elr->lr_next_sched;
3858 				next_wakeup_initialized = true;
3859 			}
3860 		}
3861 		mutex_unlock(&eli->li_list_mtx);
3862 
3863 		try_to_freeze();
3864 
3865 		cur = jiffies;
3866 		if (!next_wakeup_initialized || time_after_eq(cur, next_wakeup)) {
3867 			cond_resched();
3868 			continue;
3869 		}
3870 
3871 		schedule_timeout_interruptible(next_wakeup - cur);
3872 
3873 		if (kthread_should_stop()) {
3874 			ext4_clear_request_list();
3875 			goto exit_thread;
3876 		}
3877 	}
3878 
3879 exit_thread:
3880 	/*
3881 	 * It looks like the request list is empty, but we need
3882 	 * to check it under the li_list_mtx lock, to prevent any
3883 	 * additions into it, and of course we should lock ext4_li_mtx
3884 	 * to atomically free the list and ext4_li_info, because at
3885 	 * this point another ext4 filesystem could be registering
3886 	 * new one.
3887 	 */
3888 	mutex_lock(&ext4_li_mtx);
3889 	mutex_lock(&eli->li_list_mtx);
3890 	if (!list_empty(&eli->li_request_list)) {
3891 		mutex_unlock(&eli->li_list_mtx);
3892 		mutex_unlock(&ext4_li_mtx);
3893 		goto cont_thread;
3894 	}
3895 	mutex_unlock(&eli->li_list_mtx);
3896 	kfree(ext4_li_info);
3897 	ext4_li_info = NULL;
3898 	mutex_unlock(&ext4_li_mtx);
3899 
3900 	return 0;
3901 }
3902 
3903 static void ext4_clear_request_list(void)
3904 {
3905 	struct list_head *pos, *n;
3906 	struct ext4_li_request *elr;
3907 
3908 	mutex_lock(&ext4_li_info->li_list_mtx);
3909 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3910 		elr = list_entry(pos, struct ext4_li_request,
3911 				 lr_request);
3912 		ext4_remove_li_request(elr);
3913 	}
3914 	mutex_unlock(&ext4_li_info->li_list_mtx);
3915 }
3916 
3917 static int ext4_run_lazyinit_thread(void)
3918 {
3919 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3920 					 ext4_li_info, "ext4lazyinit");
3921 	if (IS_ERR(ext4_lazyinit_task)) {
3922 		int err = PTR_ERR(ext4_lazyinit_task);
3923 		ext4_clear_request_list();
3924 		kfree(ext4_li_info);
3925 		ext4_li_info = NULL;
3926 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3927 				 "initialization thread\n",
3928 				 err);
3929 		return err;
3930 	}
3931 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3932 	return 0;
3933 }
3934 
3935 /*
3936  * Check whether it make sense to run itable init. thread or not.
3937  * If there is at least one uninitialized inode table, return
3938  * corresponding group number, else the loop goes through all
3939  * groups and return total number of groups.
3940  */
3941 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3942 {
3943 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3944 	struct ext4_group_desc *gdp = NULL;
3945 
3946 	if (!ext4_has_group_desc_csum(sb))
3947 		return ngroups;
3948 
3949 	for (group = 0; group < ngroups; group++) {
3950 		gdp = ext4_get_group_desc(sb, group, NULL);
3951 		if (!gdp)
3952 			continue;
3953 
3954 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3955 			break;
3956 	}
3957 
3958 	return group;
3959 }
3960 
3961 static int ext4_li_info_new(void)
3962 {
3963 	struct ext4_lazy_init *eli = NULL;
3964 
3965 	eli = kzalloc_obj(*eli, GFP_KERNEL);
3966 	if (!eli)
3967 		return -ENOMEM;
3968 
3969 	INIT_LIST_HEAD(&eli->li_request_list);
3970 	mutex_init(&eli->li_list_mtx);
3971 
3972 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3973 
3974 	ext4_li_info = eli;
3975 
3976 	return 0;
3977 }
3978 
3979 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3980 					    ext4_group_t start)
3981 {
3982 	struct ext4_li_request *elr;
3983 
3984 	elr = kzalloc_obj(*elr, GFP_KERNEL);
3985 	if (!elr)
3986 		return NULL;
3987 
3988 	elr->lr_super = sb;
3989 	elr->lr_first_not_zeroed = start;
3990 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3991 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3992 		elr->lr_next_group = start;
3993 	} else {
3994 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3995 	}
3996 
3997 	/*
3998 	 * Randomize first schedule time of the request to
3999 	 * spread the inode table initialization requests
4000 	 * better.
4001 	 */
4002 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
4003 	return elr;
4004 }
4005 
4006 int ext4_register_li_request(struct super_block *sb,
4007 			     ext4_group_t first_not_zeroed)
4008 {
4009 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4010 	struct ext4_li_request *elr = NULL;
4011 	ext4_group_t ngroups = sbi->s_groups_count;
4012 	int ret = 0;
4013 
4014 	mutex_lock(&ext4_li_mtx);
4015 	if (sbi->s_li_request != NULL) {
4016 		/*
4017 		 * Reset timeout so it can be computed again, because
4018 		 * s_li_wait_mult might have changed.
4019 		 */
4020 		sbi->s_li_request->lr_timeout = 0;
4021 		goto out;
4022 	}
4023 
4024 	if (ext4_emergency_state(sb) || sb_rdonly(sb) ||
4025 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4026 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4027 		goto out;
4028 
4029 	elr = ext4_li_request_new(sb, first_not_zeroed);
4030 	if (!elr) {
4031 		ret = -ENOMEM;
4032 		goto out;
4033 	}
4034 
4035 	if (NULL == ext4_li_info) {
4036 		ret = ext4_li_info_new();
4037 		if (ret)
4038 			goto out;
4039 	}
4040 
4041 	mutex_lock(&ext4_li_info->li_list_mtx);
4042 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4043 	mutex_unlock(&ext4_li_info->li_list_mtx);
4044 
4045 	sbi->s_li_request = elr;
4046 	/*
4047 	 * set elr to NULL here since it has been inserted to
4048 	 * the request_list and the removal and free of it is
4049 	 * handled by ext4_clear_request_list from now on.
4050 	 */
4051 	elr = NULL;
4052 
4053 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4054 		ret = ext4_run_lazyinit_thread();
4055 		if (ret)
4056 			goto out;
4057 	}
4058 out:
4059 	mutex_unlock(&ext4_li_mtx);
4060 	if (ret)
4061 		kfree(elr);
4062 	return ret;
4063 }
4064 
4065 /*
4066  * We do not need to lock anything since this is called on
4067  * module unload.
4068  */
4069 static void ext4_destroy_lazyinit_thread(void)
4070 {
4071 	/*
4072 	 * If thread exited earlier
4073 	 * there's nothing to be done.
4074 	 */
4075 	if (!ext4_li_info || !ext4_lazyinit_task)
4076 		return;
4077 
4078 	kthread_stop(ext4_lazyinit_task);
4079 }
4080 
4081 static int set_journal_csum_feature_set(struct super_block *sb)
4082 {
4083 	int ret = 1;
4084 	int compat, incompat;
4085 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4086 
4087 	if (ext4_has_feature_metadata_csum(sb)) {
4088 		/* journal checksum v3 */
4089 		compat = 0;
4090 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4091 	} else {
4092 		/* journal checksum v1 */
4093 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4094 		incompat = 0;
4095 	}
4096 
4097 	jbd2_journal_clear_features(sbi->s_journal,
4098 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4099 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4100 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4101 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4102 		ret = jbd2_journal_set_features(sbi->s_journal,
4103 				compat, 0,
4104 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4105 				incompat);
4106 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4107 		ret = jbd2_journal_set_features(sbi->s_journal,
4108 				compat, 0,
4109 				incompat);
4110 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4111 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4112 	} else {
4113 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4114 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4115 	}
4116 
4117 	return ret;
4118 }
4119 
4120 /*
4121  * Note: calculating the overhead so we can be compatible with
4122  * historical BSD practice is quite difficult in the face of
4123  * clusters/bigalloc.  This is because multiple metadata blocks from
4124  * different block group can end up in the same allocation cluster.
4125  * Calculating the exact overhead in the face of clustered allocation
4126  * requires either O(all block bitmaps) in memory or O(number of block
4127  * groups**2) in time.  We will still calculate the superblock for
4128  * older file systems --- and if we come across with a bigalloc file
4129  * system with zero in s_overhead_clusters the estimate will be close to
4130  * correct especially for very large cluster sizes --- but for newer
4131  * file systems, it's better to calculate this figure once at mkfs
4132  * time, and store it in the superblock.  If the superblock value is
4133  * present (even for non-bigalloc file systems), we will use it.
4134  */
4135 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4136 			  char *buf)
4137 {
4138 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4139 	struct ext4_group_desc	*gdp;
4140 	ext4_fsblk_t		first_block, last_block, b;
4141 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4142 	int			s, j, count = 0;
4143 	int			has_super = ext4_bg_has_super(sb, grp);
4144 
4145 	if (!ext4_has_feature_bigalloc(sb))
4146 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4147 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4148 			sbi->s_itb_per_group + 2);
4149 
4150 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4151 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4152 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4153 	for (i = 0; i < ngroups; i++) {
4154 		gdp = ext4_get_group_desc(sb, i, NULL);
4155 		b = ext4_block_bitmap(sb, gdp);
4156 		if (b >= first_block && b <= last_block) {
4157 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4158 			count++;
4159 		}
4160 		b = ext4_inode_bitmap(sb, gdp);
4161 		if (b >= first_block && b <= last_block) {
4162 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4163 			count++;
4164 		}
4165 		b = ext4_inode_table(sb, gdp);
4166 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4167 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4168 				int c = EXT4_B2C(sbi, b - first_block);
4169 				ext4_set_bit(c, buf);
4170 				count++;
4171 			}
4172 		if (i != grp)
4173 			continue;
4174 		s = 0;
4175 		if (ext4_bg_has_super(sb, grp)) {
4176 			ext4_set_bit(s++, buf);
4177 			count++;
4178 		}
4179 		j = ext4_bg_num_gdb(sb, grp);
4180 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4181 			ext4_error(sb, "Invalid number of block group "
4182 				   "descriptor blocks: %d", j);
4183 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4184 		}
4185 		count += j;
4186 		for (; j > 0; j--)
4187 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4188 	}
4189 	if (!count)
4190 		return 0;
4191 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4192 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4193 }
4194 
4195 /*
4196  * Compute the overhead and stash it in sbi->s_overhead
4197  */
4198 int ext4_calculate_overhead(struct super_block *sb)
4199 {
4200 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4201 	struct ext4_super_block *es = sbi->s_es;
4202 	struct inode *j_inode;
4203 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4204 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4205 	ext4_fsblk_t overhead = 0;
4206 	char *buf = kvmalloc(sb->s_blocksize, GFP_NOFS | __GFP_ZERO);
4207 
4208 	if (!buf)
4209 		return -ENOMEM;
4210 
4211 	/*
4212 	 * Compute the overhead (FS structures).  This is constant
4213 	 * for a given filesystem unless the number of block groups
4214 	 * changes so we cache the previous value until it does.
4215 	 */
4216 
4217 	/*
4218 	 * All of the blocks before first_data_block are overhead
4219 	 */
4220 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4221 
4222 	/*
4223 	 * Add the overhead found in each block group
4224 	 */
4225 	for (i = 0; i < ngroups; i++) {
4226 		int blks;
4227 
4228 		blks = count_overhead(sb, i, buf);
4229 		overhead += blks;
4230 		if (blks)
4231 			memset(buf, 0, sb->s_blocksize);
4232 		cond_resched();
4233 	}
4234 
4235 	/*
4236 	 * Add the internal journal blocks whether the journal has been
4237 	 * loaded or not
4238 	 */
4239 	if (sbi->s_journal && !sbi->s_journal_bdev_file)
4240 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4241 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4242 		/* j_inum for internal journal is non-zero */
4243 		j_inode = ext4_get_journal_inode(sb, j_inum);
4244 		if (!IS_ERR(j_inode)) {
4245 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4246 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4247 			iput(j_inode);
4248 		} else {
4249 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4250 		}
4251 	}
4252 	sbi->s_overhead = overhead;
4253 	smp_wmb();
4254 	kvfree(buf);
4255 	return 0;
4256 }
4257 
4258 static void ext4_set_resv_clusters(struct super_block *sb)
4259 {
4260 	ext4_fsblk_t resv_clusters;
4261 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4262 
4263 	/*
4264 	 * There's no need to reserve anything when we aren't using extents.
4265 	 * The space estimates are exact, there are no unwritten extents,
4266 	 * hole punching doesn't need new metadata... This is needed especially
4267 	 * to keep ext2/3 backward compatibility.
4268 	 */
4269 	if (!ext4_has_feature_extents(sb))
4270 		return;
4271 	/*
4272 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4273 	 * This should cover the situations where we can not afford to run
4274 	 * out of space like for example punch hole, or converting
4275 	 * unwritten extents in delalloc path. In most cases such
4276 	 * allocation would require 1, or 2 blocks, higher numbers are
4277 	 * very rare.
4278 	 */
4279 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4280 			 sbi->s_cluster_bits);
4281 
4282 	do_div(resv_clusters, 50);
4283 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4284 
4285 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4286 }
4287 
4288 static const char *ext4_quota_mode(struct super_block *sb)
4289 {
4290 #ifdef CONFIG_QUOTA
4291 	if (!ext4_quota_capable(sb))
4292 		return "none";
4293 
4294 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4295 		return "journalled";
4296 	else
4297 		return "writeback";
4298 #else
4299 	return "disabled";
4300 #endif
4301 }
4302 
4303 static void ext4_setup_csum_trigger(struct super_block *sb,
4304 				    enum ext4_journal_trigger_type type,
4305 				    void (*trigger)(
4306 					struct jbd2_buffer_trigger_type *type,
4307 					struct buffer_head *bh,
4308 					void *mapped_data,
4309 					size_t size))
4310 {
4311 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4312 
4313 	sbi->s_journal_triggers[type].sb = sb;
4314 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4315 }
4316 
4317 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4318 {
4319 	if (!sbi)
4320 		return;
4321 
4322 	kfree(sbi->s_blockgroup_lock);
4323 	fs_put_dax(sbi->s_daxdev, NULL);
4324 	kfree(sbi);
4325 }
4326 
4327 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4328 {
4329 	struct ext4_sb_info *sbi;
4330 
4331 	sbi = kzalloc_obj(*sbi, GFP_KERNEL);
4332 	if (!sbi)
4333 		return NULL;
4334 
4335 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4336 					   NULL, NULL);
4337 
4338 	sbi->s_blockgroup_lock =
4339 		kzalloc_obj(struct blockgroup_lock, GFP_KERNEL);
4340 
4341 	if (!sbi->s_blockgroup_lock)
4342 		goto err_out;
4343 
4344 	sb->s_fs_info = sbi;
4345 	sbi->s_sb = sb;
4346 	return sbi;
4347 err_out:
4348 	fs_put_dax(sbi->s_daxdev, NULL);
4349 	kfree(sbi);
4350 	return NULL;
4351 }
4352 
4353 static void ext4_set_def_opts(struct super_block *sb,
4354 			      struct ext4_super_block *es)
4355 {
4356 	unsigned long def_mount_opts;
4357 
4358 	/* Set defaults before we parse the mount options */
4359 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4360 	set_opt(sb, INIT_INODE_TABLE);
4361 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4362 		set_opt(sb, DEBUG);
4363 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4364 		set_opt(sb, GRPID);
4365 	if (def_mount_opts & EXT4_DEFM_UID16)
4366 		set_opt(sb, NO_UID32);
4367 	/* xattr user namespace & acls are now defaulted on */
4368 	set_opt(sb, XATTR_USER);
4369 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4370 	set_opt(sb, POSIX_ACL);
4371 #endif
4372 	if (ext4_has_feature_fast_commit(sb))
4373 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4374 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4375 	if (ext4_has_feature_metadata_csum(sb))
4376 		set_opt(sb, JOURNAL_CHECKSUM);
4377 
4378 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4379 		set_opt(sb, JOURNAL_DATA);
4380 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4381 		set_opt(sb, ORDERED_DATA);
4382 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4383 		set_opt(sb, WRITEBACK_DATA);
4384 
4385 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4386 		set_opt(sb, ERRORS_PANIC);
4387 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4388 		set_opt(sb, ERRORS_CONT);
4389 	else
4390 		set_opt(sb, ERRORS_RO);
4391 	/* block_validity enabled by default; disable with noblock_validity */
4392 	set_opt(sb, BLOCK_VALIDITY);
4393 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4394 		set_opt(sb, DISCARD);
4395 
4396 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4397 		set_opt(sb, BARRIER);
4398 
4399 	/*
4400 	 * enable delayed allocation by default
4401 	 * Use -o nodelalloc to turn it off
4402 	 */
4403 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4404 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4405 		set_opt(sb, DELALLOC);
4406 
4407 	set_opt(sb, DIOREAD_NOLOCK);
4408 }
4409 
4410 static int ext4_handle_clustersize(struct super_block *sb)
4411 {
4412 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4413 	struct ext4_super_block *es = sbi->s_es;
4414 	int clustersize;
4415 
4416 	/* Handle clustersize */
4417 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4418 	if (ext4_has_feature_bigalloc(sb)) {
4419 		if (clustersize < sb->s_blocksize) {
4420 			ext4_msg(sb, KERN_ERR,
4421 				 "cluster size (%d) smaller than "
4422 				 "block size (%lu)", clustersize, sb->s_blocksize);
4423 			return -EINVAL;
4424 		}
4425 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4426 			le32_to_cpu(es->s_log_block_size);
4427 	} else {
4428 		if (clustersize != sb->s_blocksize) {
4429 			ext4_msg(sb, KERN_ERR,
4430 				 "fragment/cluster size (%d) != "
4431 				 "block size (%lu)", clustersize, sb->s_blocksize);
4432 			return -EINVAL;
4433 		}
4434 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4435 			ext4_msg(sb, KERN_ERR,
4436 				 "#blocks per group too big: %lu",
4437 				 sbi->s_blocks_per_group);
4438 			return -EINVAL;
4439 		}
4440 		sbi->s_cluster_bits = 0;
4441 	}
4442 	sbi->s_clusters_per_group = le32_to_cpu(es->s_clusters_per_group);
4443 	if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4444 		ext4_msg(sb, KERN_ERR, "#clusters per group too big: %lu",
4445 			 sbi->s_clusters_per_group);
4446 		return -EINVAL;
4447 	}
4448 	if (sbi->s_blocks_per_group !=
4449 	    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4450 		ext4_msg(sb, KERN_ERR,
4451 			 "blocks per group (%lu) and clusters per group (%lu) inconsistent",
4452 			 sbi->s_blocks_per_group, sbi->s_clusters_per_group);
4453 		return -EINVAL;
4454 	}
4455 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4456 
4457 	/* Do we have standard group size of clustersize * 8 blocks ? */
4458 	if (sbi->s_blocks_per_group == clustersize << 3)
4459 		set_opt2(sb, STD_GROUP_SIZE);
4460 
4461 	return 0;
4462 }
4463 
4464 /*
4465  * ext4_atomic_write_init: Initializes filesystem min & max atomic write units.
4466  * With non-bigalloc filesystem awu will be based upon filesystem blocksize
4467  * & bdev awu units.
4468  * With bigalloc it will be based upon bigalloc cluster size & bdev awu units.
4469  * @sb: super block
4470  */
4471 static void ext4_atomic_write_init(struct super_block *sb)
4472 {
4473 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4474 	struct block_device *bdev = sb->s_bdev;
4475 	unsigned int clustersize = EXT4_CLUSTER_SIZE(sb);
4476 
4477 	if (!bdev_can_atomic_write(bdev))
4478 		return;
4479 
4480 	if (!ext4_has_feature_extents(sb))
4481 		return;
4482 
4483 	sbi->s_awu_min = max(sb->s_blocksize,
4484 			      bdev_atomic_write_unit_min_bytes(bdev));
4485 	sbi->s_awu_max = min(clustersize,
4486 			      bdev_atomic_write_unit_max_bytes(bdev));
4487 	if (sbi->s_awu_min && sbi->s_awu_max &&
4488 	    sbi->s_awu_min <= sbi->s_awu_max) {
4489 		ext4_msg(sb, KERN_NOTICE, "Supports (experimental) DIO atomic writes awu_min: %u, awu_max: %u",
4490 			 sbi->s_awu_min, sbi->s_awu_max);
4491 	} else {
4492 		sbi->s_awu_min = 0;
4493 		sbi->s_awu_max = 0;
4494 	}
4495 }
4496 
4497 static void ext4_fast_commit_init(struct super_block *sb)
4498 {
4499 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4500 
4501 	/* Initialize fast commit stuff */
4502 	atomic_set(&sbi->s_fc_subtid, 0);
4503 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4504 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4505 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4506 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4507 	sbi->s_fc_bytes = 0;
4508 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4509 	sbi->s_fc_ineligible_tid = 0;
4510 	mutex_init(&sbi->s_fc_lock);
4511 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4512 	sbi->s_fc_replay_state.fc_regions = NULL;
4513 	sbi->s_fc_replay_state.fc_regions_size = 0;
4514 	sbi->s_fc_replay_state.fc_regions_used = 0;
4515 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4516 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4517 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4518 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4519 }
4520 
4521 static int ext4_inode_info_init(struct super_block *sb,
4522 				struct ext4_super_block *es)
4523 {
4524 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4525 
4526 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4527 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4528 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4529 	} else {
4530 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4531 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4532 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4533 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4534 				 sbi->s_first_ino);
4535 			return -EINVAL;
4536 		}
4537 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4538 		    (!is_power_of_2(sbi->s_inode_size)) ||
4539 		    (sbi->s_inode_size > sb->s_blocksize)) {
4540 			ext4_msg(sb, KERN_ERR,
4541 			       "unsupported inode size: %d",
4542 			       sbi->s_inode_size);
4543 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4544 			return -EINVAL;
4545 		}
4546 		/*
4547 		 * i_atime_extra is the last extra field available for
4548 		 * [acm]times in struct ext4_inode. Checking for that
4549 		 * field should suffice to ensure we have extra space
4550 		 * for all three.
4551 		 */
4552 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4553 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4554 			sb->s_time_gran = 1;
4555 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4556 		} else {
4557 			sb->s_time_gran = NSEC_PER_SEC;
4558 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4559 		}
4560 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4561 	}
4562 
4563 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4564 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4565 			EXT4_GOOD_OLD_INODE_SIZE;
4566 		if (ext4_has_feature_extra_isize(sb)) {
4567 			unsigned v, max = (sbi->s_inode_size -
4568 					   EXT4_GOOD_OLD_INODE_SIZE);
4569 
4570 			v = le16_to_cpu(es->s_want_extra_isize);
4571 			if (v > max) {
4572 				ext4_msg(sb, KERN_ERR,
4573 					 "bad s_want_extra_isize: %d", v);
4574 				return -EINVAL;
4575 			}
4576 			if (sbi->s_want_extra_isize < v)
4577 				sbi->s_want_extra_isize = v;
4578 
4579 			v = le16_to_cpu(es->s_min_extra_isize);
4580 			if (v > max) {
4581 				ext4_msg(sb, KERN_ERR,
4582 					 "bad s_min_extra_isize: %d", v);
4583 				return -EINVAL;
4584 			}
4585 			if (sbi->s_want_extra_isize < v)
4586 				sbi->s_want_extra_isize = v;
4587 		}
4588 	}
4589 
4590 	return 0;
4591 }
4592 
4593 #if IS_ENABLED(CONFIG_UNICODE)
4594 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4595 {
4596 	const struct ext4_sb_encodings *encoding_info;
4597 	struct unicode_map *encoding;
4598 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4599 
4600 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4601 		return 0;
4602 
4603 	encoding_info = ext4_sb_read_encoding(es);
4604 	if (!encoding_info) {
4605 		ext4_msg(sb, KERN_ERR,
4606 			"Encoding requested by superblock is unknown");
4607 		return -EINVAL;
4608 	}
4609 
4610 	encoding = utf8_load(encoding_info->version);
4611 	if (IS_ERR(encoding)) {
4612 		ext4_msg(sb, KERN_ERR,
4613 			"can't mount with superblock charset: %s-%u.%u.%u "
4614 			"not supported by the kernel. flags: 0x%x.",
4615 			encoding_info->name,
4616 			unicode_major(encoding_info->version),
4617 			unicode_minor(encoding_info->version),
4618 			unicode_rev(encoding_info->version),
4619 			encoding_flags);
4620 		return -EINVAL;
4621 	}
4622 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4623 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4624 		unicode_major(encoding_info->version),
4625 		unicode_minor(encoding_info->version),
4626 		unicode_rev(encoding_info->version),
4627 		encoding_flags);
4628 
4629 	sb->s_encoding = encoding;
4630 	sb->s_encoding_flags = encoding_flags;
4631 
4632 	return 0;
4633 }
4634 #else
4635 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4636 {
4637 	return 0;
4638 }
4639 #endif
4640 
4641 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4642 {
4643 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4644 
4645 	/* Warn if metadata_csum and gdt_csum are both set. */
4646 	if (ext4_has_feature_metadata_csum(sb) &&
4647 	    ext4_has_feature_gdt_csum(sb))
4648 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4649 			     "redundant flags; please run fsck.");
4650 
4651 	/* Check for a known checksum algorithm */
4652 	if (!ext4_verify_csum_type(sb, es)) {
4653 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4654 			 "unknown checksum algorithm.");
4655 		return -EINVAL;
4656 	}
4657 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4658 				ext4_orphan_file_block_trigger);
4659 
4660 	/* Check superblock checksum */
4661 	if (!ext4_superblock_csum_verify(sb, es)) {
4662 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4663 			 "invalid superblock checksum.  Run e2fsck?");
4664 		return -EFSBADCRC;
4665 	}
4666 
4667 	/* Precompute checksum seed for all metadata */
4668 	if (ext4_has_feature_csum_seed(sb))
4669 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4670 	else if (ext4_has_feature_metadata_csum(sb) ||
4671 		 ext4_has_feature_ea_inode(sb))
4672 		sbi->s_csum_seed = ext4_chksum(~0, es->s_uuid,
4673 					       sizeof(es->s_uuid));
4674 	return 0;
4675 }
4676 
4677 static int ext4_check_feature_compatibility(struct super_block *sb,
4678 					    struct ext4_super_block *es,
4679 					    int silent)
4680 {
4681 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4682 
4683 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4684 	    (ext4_has_compat_features(sb) ||
4685 	     ext4_has_ro_compat_features(sb) ||
4686 	     ext4_has_incompat_features(sb)))
4687 		ext4_msg(sb, KERN_WARNING,
4688 		       "feature flags set on rev 0 fs, "
4689 		       "running e2fsck is recommended");
4690 
4691 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4692 		set_opt2(sb, HURD_COMPAT);
4693 		if (ext4_has_feature_64bit(sb)) {
4694 			ext4_msg(sb, KERN_ERR,
4695 				 "The Hurd can't support 64-bit file systems");
4696 			return -EINVAL;
4697 		}
4698 
4699 		/*
4700 		 * ea_inode feature uses l_i_version field which is not
4701 		 * available in HURD_COMPAT mode.
4702 		 */
4703 		if (ext4_has_feature_ea_inode(sb)) {
4704 			ext4_msg(sb, KERN_ERR,
4705 				 "ea_inode feature is not supported for Hurd");
4706 			return -EINVAL;
4707 		}
4708 	}
4709 
4710 	if (IS_EXT2_SB(sb)) {
4711 		if (ext2_feature_set_ok(sb))
4712 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4713 				 "using the ext4 subsystem");
4714 		else {
4715 			/*
4716 			 * If we're probing be silent, if this looks like
4717 			 * it's actually an ext[34] filesystem.
4718 			 */
4719 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4720 				return -EINVAL;
4721 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4722 				 "to feature incompatibilities");
4723 			return -EINVAL;
4724 		}
4725 	}
4726 
4727 	if (IS_EXT3_SB(sb)) {
4728 		if (ext3_feature_set_ok(sb))
4729 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4730 				 "using the ext4 subsystem");
4731 		else {
4732 			/*
4733 			 * If we're probing be silent, if this looks like
4734 			 * it's actually an ext4 filesystem.
4735 			 */
4736 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4737 				return -EINVAL;
4738 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4739 				 "to feature incompatibilities");
4740 			return -EINVAL;
4741 		}
4742 	}
4743 
4744 	/*
4745 	 * Check feature flags regardless of the revision level, since we
4746 	 * previously didn't change the revision level when setting the flags,
4747 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4748 	 */
4749 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4750 		return -EINVAL;
4751 
4752 	if (sbi->s_daxdev) {
4753 		if (sb->s_blocksize == PAGE_SIZE)
4754 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4755 		else
4756 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4757 	}
4758 
4759 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4760 		if (ext4_has_feature_inline_data(sb)) {
4761 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4762 					" that may contain inline data");
4763 			return -EINVAL;
4764 		}
4765 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4766 			ext4_msg(sb, KERN_ERR,
4767 				"DAX unsupported by block device.");
4768 			return -EINVAL;
4769 		}
4770 	}
4771 
4772 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4773 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4774 			 es->s_encryption_level);
4775 		return -EINVAL;
4776 	}
4777 
4778 	return 0;
4779 }
4780 
4781 static int ext4_check_geometry(struct super_block *sb,
4782 			       struct ext4_super_block *es)
4783 {
4784 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4785 	__u64 blocks_count;
4786 	int err;
4787 
4788 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4789 		ext4_msg(sb, KERN_ERR,
4790 			 "Number of reserved GDT blocks insanely large: %d",
4791 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4792 		return -EINVAL;
4793 	}
4794 	/*
4795 	 * Test whether we have more sectors than will fit in sector_t,
4796 	 * and whether the max offset is addressable by the page cache.
4797 	 */
4798 	err = generic_check_addressable(sb->s_blocksize_bits,
4799 					ext4_blocks_count(es));
4800 	if (err) {
4801 		ext4_msg(sb, KERN_ERR, "filesystem"
4802 			 " too large to mount safely on this system");
4803 		return err;
4804 	}
4805 
4806 	/* check blocks count against device size */
4807 	blocks_count = sb_bdev_nr_blocks(sb);
4808 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4809 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4810 		       "exceeds size of device (%llu blocks)",
4811 		       ext4_blocks_count(es), blocks_count);
4812 		return -EINVAL;
4813 	}
4814 
4815 	/*
4816 	 * It makes no sense for the first data block to be beyond the end
4817 	 * of the filesystem.
4818 	 */
4819 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4820 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4821 			 "block %u is beyond end of filesystem (%llu)",
4822 			 le32_to_cpu(es->s_first_data_block),
4823 			 ext4_blocks_count(es));
4824 		return -EINVAL;
4825 	}
4826 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4827 	    (sbi->s_cluster_ratio == 1)) {
4828 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4829 			 "block is 0 with a 1k block and cluster size");
4830 		return -EINVAL;
4831 	}
4832 
4833 	blocks_count = (ext4_blocks_count(es) -
4834 			le32_to_cpu(es->s_first_data_block) +
4835 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4836 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4837 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4838 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4839 		       "(block count %llu, first data block %u, "
4840 		       "blocks per group %lu)", blocks_count,
4841 		       ext4_blocks_count(es),
4842 		       le32_to_cpu(es->s_first_data_block),
4843 		       EXT4_BLOCKS_PER_GROUP(sb));
4844 		return -EINVAL;
4845 	}
4846 	sbi->s_groups_count = blocks_count;
4847 	sbi->s_blockfile_groups = min(sbi->s_groups_count,
4848 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4849 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4850 	    le32_to_cpu(es->s_inodes_count)) {
4851 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4852 			 le32_to_cpu(es->s_inodes_count),
4853 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4854 		return -EINVAL;
4855 	}
4856 
4857 	return 0;
4858 }
4859 
4860 static int ext4_group_desc_init(struct super_block *sb,
4861 				struct ext4_super_block *es,
4862 				ext4_fsblk_t logical_sb_block,
4863 				ext4_group_t *first_not_zeroed)
4864 {
4865 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4866 	unsigned int db_count;
4867 	ext4_fsblk_t block;
4868 	int i;
4869 
4870 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4871 		   EXT4_DESC_PER_BLOCK(sb);
4872 	if (ext4_has_feature_meta_bg(sb)) {
4873 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4874 			ext4_msg(sb, KERN_WARNING,
4875 				 "first meta block group too large: %u "
4876 				 "(group descriptor block count %u)",
4877 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4878 			return -EINVAL;
4879 		}
4880 	}
4881 	rcu_assign_pointer(sbi->s_group_desc,
4882 			   kvmalloc_objs(struct buffer_head *, db_count, GFP_KERNEL));
4883 	if (sbi->s_group_desc == NULL) {
4884 		ext4_msg(sb, KERN_ERR, "not enough memory");
4885 		return -ENOMEM;
4886 	}
4887 
4888 	bgl_lock_init(sbi->s_blockgroup_lock);
4889 
4890 	/* Pre-read the descriptors into the buffer cache */
4891 	for (i = 0; i < db_count; i++) {
4892 		block = descriptor_loc(sb, logical_sb_block, i);
4893 		ext4_sb_breadahead_unmovable(sb, block);
4894 	}
4895 
4896 	for (i = 0; i < db_count; i++) {
4897 		struct buffer_head *bh;
4898 
4899 		block = descriptor_loc(sb, logical_sb_block, i);
4900 		bh = ext4_sb_bread_unmovable(sb, block);
4901 		if (IS_ERR(bh)) {
4902 			ext4_msg(sb, KERN_ERR,
4903 			       "can't read group descriptor %d", i);
4904 			sbi->s_gdb_count = i;
4905 			return PTR_ERR(bh);
4906 		}
4907 		rcu_read_lock();
4908 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4909 		rcu_read_unlock();
4910 	}
4911 	sbi->s_gdb_count = db_count;
4912 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4913 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4914 		return -EFSCORRUPTED;
4915 	}
4916 
4917 	return 0;
4918 }
4919 
4920 static int ext4_load_and_init_journal(struct super_block *sb,
4921 				      struct ext4_super_block *es,
4922 				      struct ext4_fs_context *ctx)
4923 {
4924 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4925 	int err;
4926 
4927 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4928 	if (err)
4929 		return err;
4930 
4931 	if (ext4_has_feature_64bit(sb) &&
4932 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4933 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4934 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4935 		goto out;
4936 	}
4937 
4938 	if (!set_journal_csum_feature_set(sb)) {
4939 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4940 			 "feature set");
4941 		goto out;
4942 	}
4943 
4944 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4945 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4946 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4947 		ext4_msg(sb, KERN_ERR,
4948 			"Failed to set fast commit journal feature");
4949 		goto out;
4950 	}
4951 
4952 	/* We have now updated the journal if required, so we can
4953 	 * validate the data journaling mode. */
4954 	switch (test_opt(sb, DATA_FLAGS)) {
4955 	case 0:
4956 		/* No mode set, assume a default based on the journal
4957 		 * capabilities: ORDERED_DATA if the journal can
4958 		 * cope, else JOURNAL_DATA
4959 		 */
4960 		if (jbd2_journal_check_available_features
4961 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4962 			set_opt(sb, ORDERED_DATA);
4963 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4964 		} else {
4965 			set_opt(sb, JOURNAL_DATA);
4966 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4967 		}
4968 		break;
4969 
4970 	case EXT4_MOUNT_ORDERED_DATA:
4971 	case EXT4_MOUNT_WRITEBACK_DATA:
4972 		if (!jbd2_journal_check_available_features
4973 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4974 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4975 			       "requested data journaling mode");
4976 			goto out;
4977 		}
4978 		break;
4979 	default:
4980 		break;
4981 	}
4982 
4983 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4984 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4985 		ext4_msg(sb, KERN_ERR, "can't mount with "
4986 			"journal_async_commit in data=ordered mode");
4987 		goto out;
4988 	}
4989 
4990 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4991 
4992 	sbi->s_journal->j_submit_inode_data_buffers =
4993 		ext4_journal_submit_inode_data_buffers;
4994 	sbi->s_journal->j_finish_inode_data_buffers =
4995 		ext4_journal_finish_inode_data_buffers;
4996 
4997 	return 0;
4998 
4999 out:
5000 	ext4_journal_destroy(sbi, sbi->s_journal);
5001 	return -EINVAL;
5002 }
5003 
5004 static int ext4_check_journal_data_mode(struct super_block *sb)
5005 {
5006 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5007 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
5008 			    "data=journal disables delayed allocation, "
5009 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
5010 		/* can't mount with both data=journal and dioread_nolock. */
5011 		clear_opt(sb, DIOREAD_NOLOCK);
5012 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5013 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5014 			ext4_msg(sb, KERN_ERR, "can't mount with "
5015 				 "both data=journal and delalloc");
5016 			return -EINVAL;
5017 		}
5018 		if (test_opt(sb, DAX_ALWAYS)) {
5019 			ext4_msg(sb, KERN_ERR, "can't mount with "
5020 				 "both data=journal and dax");
5021 			return -EINVAL;
5022 		}
5023 		if (ext4_has_feature_encrypt(sb)) {
5024 			ext4_msg(sb, KERN_WARNING,
5025 				 "encrypted files will use data=ordered "
5026 				 "instead of data journaling mode");
5027 		}
5028 		if (test_opt(sb, DELALLOC))
5029 			clear_opt(sb, DELALLOC);
5030 	} else {
5031 		sb->s_iflags |= SB_I_CGROUPWB;
5032 	}
5033 
5034 	return 0;
5035 }
5036 
5037 static const char *ext4_has_journal_option(struct super_block *sb)
5038 {
5039 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5040 
5041 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
5042 		return "journal_async_commit";
5043 	if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM))
5044 		return "journal_checksum";
5045 	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
5046 		return "commit=";
5047 	if (EXT4_MOUNT_DATA_FLAGS &
5048 	    (sbi->s_mount_opt ^ sbi->s_def_mount_opt))
5049 		return "data=";
5050 	if (test_opt(sb, DATA_ERR_ABORT))
5051 		return "data_err=abort";
5052 	return NULL;
5053 }
5054 
5055 /*
5056  * Limit the maximum folio order to 2048 blocks to prevent overestimation
5057  * of reserve handle credits during the folio writeback in environments
5058  * where the PAGE_SIZE exceeds 4KB.
5059  */
5060 #define EXT4_MAX_PAGECACHE_ORDER(sb)		\
5061 		umin(MAX_PAGECACHE_ORDER, (11 + (sb)->s_blocksize_bits - PAGE_SHIFT))
5062 static void ext4_set_max_mapping_order(struct super_block *sb)
5063 {
5064 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5065 
5066 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5067 		sbi->s_max_folio_order = sbi->s_min_folio_order;
5068 	else
5069 		sbi->s_max_folio_order = EXT4_MAX_PAGECACHE_ORDER(sb);
5070 }
5071 
5072 static int ext4_check_large_folio(struct super_block *sb)
5073 {
5074 	const char *err_str = NULL;
5075 
5076 	if (ext4_has_feature_encrypt(sb))
5077 		err_str = "encrypt";
5078 
5079 	if (!err_str) {
5080 		ext4_set_max_mapping_order(sb);
5081 	} else if (sb->s_blocksize > PAGE_SIZE) {
5082 		ext4_msg(sb, KERN_ERR, "bs(%lu) > ps(%lu) unsupported for %s",
5083 			 sb->s_blocksize, PAGE_SIZE, err_str);
5084 		return -EINVAL;
5085 	}
5086 
5087 	return 0;
5088 }
5089 
5090 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5091 			   int silent)
5092 {
5093 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5094 	struct ext4_super_block *es;
5095 	ext4_fsblk_t logical_sb_block;
5096 	unsigned long offset = 0;
5097 	struct buffer_head *bh;
5098 	int ret = -EINVAL;
5099 	int blocksize;
5100 
5101 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5102 	if (!blocksize) {
5103 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5104 		return -EINVAL;
5105 	}
5106 
5107 	/*
5108 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5109 	 * block sizes.  We need to calculate the offset from buffer start.
5110 	 */
5111 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5112 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5113 		offset = do_div(logical_sb_block, blocksize);
5114 	} else {
5115 		logical_sb_block = sbi->s_sb_block;
5116 	}
5117 
5118 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5119 	if (IS_ERR(bh)) {
5120 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5121 		return PTR_ERR(bh);
5122 	}
5123 	/*
5124 	 * Note: s_es must be initialized as soon as possible because
5125 	 *       some ext4 macro-instructions depend on its value
5126 	 */
5127 	es = (struct ext4_super_block *) (bh->b_data + offset);
5128 	sbi->s_es = es;
5129 	sb->s_magic = le16_to_cpu(es->s_magic);
5130 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5131 		if (!silent)
5132 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5133 		goto out;
5134 	}
5135 
5136 	if (le32_to_cpu(es->s_log_block_size) >
5137 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5138 		ext4_msg(sb, KERN_ERR,
5139 			 "Invalid log block size: %u",
5140 			 le32_to_cpu(es->s_log_block_size));
5141 		goto out;
5142 	}
5143 	if (le32_to_cpu(es->s_log_cluster_size) >
5144 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5145 		ext4_msg(sb, KERN_ERR,
5146 			 "Invalid log cluster size: %u",
5147 			 le32_to_cpu(es->s_log_cluster_size));
5148 		goto out;
5149 	}
5150 
5151 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5152 
5153 	/*
5154 	 * If the default block size is not the same as the real block size,
5155 	 * we need to reload it.
5156 	 */
5157 	if (sb->s_blocksize == blocksize)
5158 		goto success;
5159 
5160 	/*
5161 	 * bh must be released before kill_bdev(), otherwise
5162 	 * it won't be freed and its page also. kill_bdev()
5163 	 * is called by sb_set_blocksize().
5164 	 */
5165 	brelse(bh);
5166 	/* Validate the filesystem blocksize */
5167 	if (!sb_set_blocksize(sb, blocksize)) {
5168 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5169 				blocksize);
5170 		bh = NULL;
5171 		goto out;
5172 	}
5173 
5174 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5175 	offset = do_div(logical_sb_block, blocksize);
5176 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5177 	if (IS_ERR(bh)) {
5178 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5179 		ret = PTR_ERR(bh);
5180 		bh = NULL;
5181 		goto out;
5182 	}
5183 	es = (struct ext4_super_block *)(bh->b_data + offset);
5184 	sbi->s_es = es;
5185 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5186 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5187 		goto out;
5188 	}
5189 
5190 success:
5191 	sbi->s_min_folio_order = get_order(blocksize);
5192 	*lsb = logical_sb_block;
5193 	sbi->s_sbh = bh;
5194 	return 0;
5195 out:
5196 	brelse(bh);
5197 	return ret;
5198 }
5199 
5200 static int ext4_hash_info_init(struct super_block *sb)
5201 {
5202 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5203 	struct ext4_super_block *es = sbi->s_es;
5204 	unsigned int i;
5205 
5206 	sbi->s_def_hash_version = es->s_def_hash_version;
5207 
5208 	if (sbi->s_def_hash_version > DX_HASH_LAST) {
5209 		ext4_msg(sb, KERN_ERR,
5210 			 "Invalid default hash set in the superblock");
5211 		return -EINVAL;
5212 	} else if (sbi->s_def_hash_version == DX_HASH_SIPHASH) {
5213 		ext4_msg(sb, KERN_ERR,
5214 			 "SIPHASH is not a valid default hash value");
5215 		return -EINVAL;
5216 	}
5217 
5218 	for (i = 0; i < 4; i++)
5219 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5220 
5221 	if (ext4_has_feature_dir_index(sb)) {
5222 		i = le32_to_cpu(es->s_flags);
5223 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5224 			sbi->s_hash_unsigned = 3;
5225 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5226 #ifdef __CHAR_UNSIGNED__
5227 			if (!sb_rdonly(sb))
5228 				es->s_flags |=
5229 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5230 			sbi->s_hash_unsigned = 3;
5231 #else
5232 			if (!sb_rdonly(sb))
5233 				es->s_flags |=
5234 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5235 #endif
5236 		}
5237 	}
5238 	return 0;
5239 }
5240 
5241 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5242 {
5243 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5244 	struct ext4_super_block *es = sbi->s_es;
5245 	int has_huge_files;
5246 
5247 	has_huge_files = ext4_has_feature_huge_file(sb);
5248 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5249 						      has_huge_files);
5250 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5251 
5252 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5253 	if (ext4_has_feature_64bit(sb)) {
5254 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5255 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5256 		    !is_power_of_2(sbi->s_desc_size)) {
5257 			ext4_msg(sb, KERN_ERR,
5258 			       "unsupported descriptor size %lu",
5259 			       sbi->s_desc_size);
5260 			return -EINVAL;
5261 		}
5262 	} else
5263 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5264 
5265 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5266 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5267 
5268 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5269 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5270 		if (!silent)
5271 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5272 		return -EINVAL;
5273 	}
5274 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5275 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5276 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5277 			 sbi->s_inodes_per_group);
5278 		return -EINVAL;
5279 	}
5280 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5281 					sbi->s_inodes_per_block;
5282 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5283 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5284 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5285 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5286 
5287 	return 0;
5288 }
5289 
5290 /*
5291  * It's hard to get stripe aligned blocks if stripe is not aligned with
5292  * cluster, just disable stripe and alert user to simplify code and avoid
5293  * stripe aligned allocation which will rarely succeed.
5294  */
5295 static bool ext4_is_stripe_incompatible(struct super_block *sb, unsigned long stripe)
5296 {
5297 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5298 	return (stripe > 0 && sbi->s_cluster_ratio > 1 &&
5299 		stripe % sbi->s_cluster_ratio != 0);
5300 }
5301 
5302 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5303 {
5304 	struct ext4_super_block *es = NULL;
5305 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5306 	ext4_fsblk_t logical_sb_block;
5307 	struct inode *root;
5308 	int needs_recovery;
5309 	int err;
5310 	ext4_group_t first_not_zeroed;
5311 	struct ext4_fs_context *ctx = fc->fs_private;
5312 	int silent = fc->sb_flags & SB_SILENT;
5313 
5314 	/* Set defaults for the variables that will be set during parsing */
5315 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5316 		ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
5317 
5318 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5319 	sbi->s_sectors_written_start =
5320 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5321 
5322 	err = ext4_load_super(sb, &logical_sb_block, silent);
5323 	if (err)
5324 		goto out_fail;
5325 
5326 	es = sbi->s_es;
5327 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5328 
5329 	err = ext4_init_metadata_csum(sb, es);
5330 	if (err)
5331 		goto failed_mount;
5332 
5333 	ext4_set_def_opts(sb, es);
5334 
5335 	sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
5336 	sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
5337 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5338 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5339 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5340 	sbi->s_sb_update_kb = EXT4_DEF_SB_UPDATE_INTERVAL_KB;
5341 	sbi->s_sb_update_sec = EXT4_DEF_SB_UPDATE_INTERVAL_SEC;
5342 
5343 	/*
5344 	 * set default s_li_wait_mult for lazyinit, for the case there is
5345 	 * no mount option specified.
5346 	 */
5347 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5348 
5349 	err = ext4_inode_info_init(sb, es);
5350 	if (err)
5351 		goto failed_mount;
5352 
5353 	err = parse_apply_sb_mount_options(sb, ctx);
5354 	if (err < 0)
5355 		goto failed_mount;
5356 
5357 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5358 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5359 
5360 	err = ext4_check_opt_consistency(fc, sb);
5361 	if (err < 0)
5362 		goto failed_mount;
5363 
5364 	ext4_apply_options(fc, sb);
5365 
5366 	err = ext4_check_large_folio(sb);
5367 	if (err < 0)
5368 		goto failed_mount;
5369 
5370 	err = ext4_encoding_init(sb, es);
5371 	if (err)
5372 		goto failed_mount;
5373 
5374 	err = ext4_check_journal_data_mode(sb);
5375 	if (err)
5376 		goto failed_mount;
5377 
5378 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5379 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5380 
5381 	/* HSM events are allowed by default. */
5382 	sb->s_iflags |= SB_I_ALLOW_HSM;
5383 
5384 	err = ext4_check_feature_compatibility(sb, es, silent);
5385 	if (err)
5386 		goto failed_mount;
5387 
5388 	err = ext4_block_group_meta_init(sb, silent);
5389 	if (err)
5390 		goto failed_mount;
5391 
5392 	err = ext4_hash_info_init(sb);
5393 	if (err)
5394 		goto failed_mount;
5395 
5396 	err = ext4_handle_clustersize(sb);
5397 	if (err)
5398 		goto failed_mount;
5399 
5400 	err = ext4_check_geometry(sb, es);
5401 	if (err)
5402 		goto failed_mount;
5403 
5404 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5405 	spin_lock_init(&sbi->s_error_lock);
5406 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5407 
5408 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5409 	if (err)
5410 		goto failed_mount3;
5411 
5412 	err = ext4_es_register_shrinker(sbi);
5413 	if (err)
5414 		goto failed_mount3;
5415 
5416 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5417 	if (ext4_is_stripe_incompatible(sb, sbi->s_stripe)) {
5418 		ext4_msg(sb, KERN_WARNING,
5419 			 "stripe (%lu) is not aligned with cluster size (%u), "
5420 			 "stripe is disabled",
5421 			 sbi->s_stripe, sbi->s_cluster_ratio);
5422 		sbi->s_stripe = 0;
5423 	}
5424 	sbi->s_extent_max_zeroout_kb = 32;
5425 
5426 	/*
5427 	 * set up enough so that it can read an inode
5428 	 */
5429 	sb->s_op = &ext4_sops;
5430 	sb->s_export_op = &ext4_export_ops;
5431 	sb->s_xattr = ext4_xattr_handlers;
5432 #ifdef CONFIG_FS_ENCRYPTION
5433 	sb->s_cop = &ext4_cryptops;
5434 #endif
5435 #ifdef CONFIG_FS_VERITY
5436 	sb->s_vop = &ext4_verityops;
5437 #endif
5438 #ifdef CONFIG_QUOTA
5439 	sb->dq_op = &ext4_quota_operations;
5440 	if (ext4_has_feature_quota(sb))
5441 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5442 	else
5443 		sb->s_qcop = &ext4_qctl_operations;
5444 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5445 #endif
5446 	super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));
5447 	super_set_sysfs_name_bdev(sb);
5448 
5449 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5450 	mutex_init(&sbi->s_orphan_lock);
5451 
5452 	spin_lock_init(&sbi->s_bdev_wb_lock);
5453 
5454 	ext4_atomic_write_init(sb);
5455 	ext4_fast_commit_init(sb);
5456 
5457 	sb->s_root = NULL;
5458 
5459 	needs_recovery = (es->s_last_orphan != 0 ||
5460 			  ext4_has_feature_orphan_present(sb) ||
5461 			  ext4_has_feature_journal_needs_recovery(sb));
5462 
5463 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5464 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5465 		if (err)
5466 			goto failed_mount3a;
5467 	}
5468 
5469 	err = -EINVAL;
5470 	/*
5471 	 * The first inode we look at is the journal inode.  Don't try
5472 	 * root first: it may be modified in the journal!
5473 	 */
5474 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5475 		err = ext4_load_and_init_journal(sb, es, ctx);
5476 		if (err)
5477 			goto failed_mount3a;
5478 		if (bdev_read_only(sb->s_bdev))
5479 		    needs_recovery = 0;
5480 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5481 		   ext4_has_feature_journal_needs_recovery(sb)) {
5482 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5483 		       "suppressed and not mounted read-only");
5484 		goto failed_mount3a;
5485 	} else {
5486 		const char *journal_option;
5487 
5488 		/* Nojournal mode, all journal mount options are illegal */
5489 		journal_option = ext4_has_journal_option(sb);
5490 		if (journal_option != NULL) {
5491 			ext4_msg(sb, KERN_ERR,
5492 				 "can't mount with %s, fs mounted w/o journal",
5493 				 journal_option);
5494 			goto failed_mount3a;
5495 		}
5496 
5497 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5498 		clear_opt(sb, JOURNAL_CHECKSUM);
5499 		clear_opt(sb, DATA_FLAGS);
5500 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5501 		sbi->s_journal = NULL;
5502 		needs_recovery = 0;
5503 	}
5504 
5505 	if (!test_opt(sb, NO_MBCACHE)) {
5506 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5507 		if (!sbi->s_ea_block_cache) {
5508 			ext4_msg(sb, KERN_ERR,
5509 				 "Failed to create ea_block_cache");
5510 			err = -EINVAL;
5511 			goto failed_mount_wq;
5512 		}
5513 
5514 		if (ext4_has_feature_ea_inode(sb)) {
5515 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5516 			if (!sbi->s_ea_inode_cache) {
5517 				ext4_msg(sb, KERN_ERR,
5518 					 "Failed to create ea_inode_cache");
5519 				err = -EINVAL;
5520 				goto failed_mount_wq;
5521 			}
5522 		}
5523 	}
5524 
5525 	/*
5526 	 * Get the # of file system overhead blocks from the
5527 	 * superblock if present.
5528 	 */
5529 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5530 	/* ignore the precalculated value if it is ridiculous */
5531 	if (sbi->s_overhead > ext4_blocks_count(es))
5532 		sbi->s_overhead = 0;
5533 	/*
5534 	 * If the bigalloc feature is not enabled recalculating the
5535 	 * overhead doesn't take long, so we might as well just redo
5536 	 * it to make sure we are using the correct value.
5537 	 */
5538 	if (!ext4_has_feature_bigalloc(sb))
5539 		sbi->s_overhead = 0;
5540 	if (sbi->s_overhead == 0) {
5541 		err = ext4_calculate_overhead(sb);
5542 		if (err)
5543 			goto failed_mount_wq;
5544 	}
5545 
5546 	/*
5547 	 * The maximum number of concurrent works can be high and
5548 	 * concurrency isn't really necessary.  Limit it to 1.
5549 	 */
5550 	EXT4_SB(sb)->rsv_conversion_wq =
5551 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5552 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5553 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5554 		err = -ENOMEM;
5555 		goto failed_mount4;
5556 	}
5557 
5558 	/*
5559 	 * The jbd2_journal_load will have done any necessary log recovery,
5560 	 * so we can safely mount the rest of the filesystem now.
5561 	 */
5562 
5563 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5564 	if (IS_ERR(root)) {
5565 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5566 		err = PTR_ERR(root);
5567 		root = NULL;
5568 		goto failed_mount4;
5569 	}
5570 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5571 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5572 		iput(root);
5573 		err = -EFSCORRUPTED;
5574 		goto failed_mount4;
5575 	}
5576 
5577 	generic_set_sb_d_ops(sb);
5578 	sb->s_root = d_make_root(root);
5579 	if (!sb->s_root) {
5580 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5581 		err = -ENOMEM;
5582 		goto failed_mount4;
5583 	}
5584 
5585 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5586 	if (err == -EROFS) {
5587 		sb->s_flags |= SB_RDONLY;
5588 	} else if (err)
5589 		goto failed_mount4a;
5590 
5591 	ext4_set_resv_clusters(sb);
5592 
5593 	if (test_opt(sb, BLOCK_VALIDITY)) {
5594 		err = ext4_setup_system_zone(sb);
5595 		if (err) {
5596 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5597 				 "zone (%d)", err);
5598 			goto failed_mount4a;
5599 		}
5600 	}
5601 	ext4_fc_replay_cleanup(sb);
5602 
5603 	ext4_ext_init(sb);
5604 
5605 	/*
5606 	 * Enable optimize_scan if number of groups is > threshold. This can be
5607 	 * turned off by passing "mb_optimize_scan=0". This can also be
5608 	 * turned on forcefully by passing "mb_optimize_scan=1".
5609 	 */
5610 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5611 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5612 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5613 		else
5614 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5615 	}
5616 
5617 	err = ext4_percpu_param_init(sbi);
5618 	if (err)
5619 		goto failed_mount5;
5620 
5621 	err = ext4_mb_init(sb);
5622 	if (err) {
5623 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5624 			 err);
5625 		goto failed_mount5;
5626 	}
5627 
5628 	/*
5629 	 * We can only set up the journal commit callback once
5630 	 * mballoc is initialized
5631 	 */
5632 	if (sbi->s_journal)
5633 		sbi->s_journal->j_commit_callback =
5634 			ext4_journal_commit_callback;
5635 
5636 	if (ext4_has_feature_flex_bg(sb))
5637 		if (!ext4_fill_flex_info(sb)) {
5638 			ext4_msg(sb, KERN_ERR,
5639 			       "unable to initialize "
5640 			       "flex_bg meta info!");
5641 			err = -ENOMEM;
5642 			goto failed_mount6;
5643 		}
5644 
5645 	err = ext4_register_li_request(sb, first_not_zeroed);
5646 	if (err)
5647 		goto failed_mount6;
5648 
5649 	err = ext4_init_orphan_info(sb);
5650 	if (err)
5651 		goto failed_mount7;
5652 #ifdef CONFIG_QUOTA
5653 	/* Enable quota usage during mount. */
5654 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5655 		err = ext4_enable_quotas(sb);
5656 		if (err)
5657 			goto failed_mount8;
5658 	}
5659 #endif  /* CONFIG_QUOTA */
5660 
5661 	/*
5662 	 * Save the original bdev mapping's wb_err value which could be
5663 	 * used to detect the metadata async write error.
5664 	 */
5665 	errseq_check_and_advance(&sb->s_bdev->bd_mapping->wb_err,
5666 				 &sbi->s_bdev_wb_err);
5667 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5668 	ext4_orphan_cleanup(sb, es);
5669 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5670 	/*
5671 	 * Update the checksum after updating free space/inode counters and
5672 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5673 	 * checksum in the buffer cache until it is written out and
5674 	 * e2fsprogs programs trying to open a file system immediately
5675 	 * after it is mounted can fail.
5676 	 */
5677 	ext4_superblock_csum_set(sb);
5678 	if (needs_recovery) {
5679 		ext4_msg(sb, KERN_INFO, "recovery complete");
5680 		err = ext4_mark_recovery_complete(sb, es);
5681 		if (err)
5682 			goto failed_mount9;
5683 	}
5684 
5685 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev)) {
5686 		ext4_msg(sb, KERN_WARNING,
5687 			 "mounting with \"discard\" option, but the device does not support discard");
5688 		clear_opt(sb, DISCARD);
5689 	}
5690 
5691 	if (es->s_error_count) {
5692 		sbi->s_err_report_sec = 5*60;	/* first time  5 minutes */
5693 		mod_timer(&sbi->s_err_report,
5694 				  jiffies + secs_to_jiffies(sbi->s_err_report_sec));
5695 	}
5696 	sbi->s_err_report_sec = 24*60*60; /* Once a day */
5697 
5698 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5699 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5700 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5701 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5702 	atomic_set(&sbi->s_warning_count, 0);
5703 	atomic_set(&sbi->s_msg_count, 0);
5704 
5705 	/* Register sysfs after all initializations are complete. */
5706 	err = ext4_register_sysfs(sb);
5707 	if (err)
5708 		goto failed_mount9;
5709 
5710 	return 0;
5711 
5712 failed_mount9:
5713 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5714 failed_mount8: __maybe_unused
5715 	ext4_release_orphan_info(sb);
5716 failed_mount7:
5717 	ext4_unregister_li_request(sb);
5718 failed_mount6:
5719 	ext4_mb_release(sb);
5720 	ext4_flex_groups_free(sbi);
5721 failed_mount5:
5722 	ext4_percpu_param_destroy(sbi);
5723 	ext4_ext_release(sb);
5724 	ext4_release_system_zone(sb);
5725 failed_mount4a:
5726 	dput(sb->s_root);
5727 	sb->s_root = NULL;
5728 failed_mount4:
5729 	ext4_msg(sb, KERN_ERR, "mount failed");
5730 	if (EXT4_SB(sb)->rsv_conversion_wq)
5731 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5732 failed_mount_wq:
5733 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5734 	sbi->s_ea_inode_cache = NULL;
5735 
5736 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5737 	sbi->s_ea_block_cache = NULL;
5738 
5739 	if (sbi->s_journal) {
5740 		ext4_journal_destroy(sbi, sbi->s_journal);
5741 	}
5742 failed_mount3a:
5743 	ext4_es_unregister_shrinker(sbi);
5744 failed_mount3:
5745 	/* flush s_sb_upd_work before sbi destroy */
5746 	flush_work(&sbi->s_sb_upd_work);
5747 	ext4_stop_mmpd(sbi);
5748 	timer_delete_sync(&sbi->s_err_report);
5749 	ext4_group_desc_free(sbi);
5750 failed_mount:
5751 #if IS_ENABLED(CONFIG_UNICODE)
5752 	utf8_unload(sb->s_encoding);
5753 #endif
5754 
5755 #ifdef CONFIG_QUOTA
5756 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5757 		kfree(get_qf_name(sb, sbi, i));
5758 #endif
5759 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5760 	brelse(sbi->s_sbh);
5761 	if (sbi->s_journal_bdev_file) {
5762 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
5763 		bdev_fput(sbi->s_journal_bdev_file);
5764 	}
5765 out_fail:
5766 	invalidate_bdev(sb->s_bdev);
5767 	sb->s_fs_info = NULL;
5768 	return err;
5769 }
5770 
5771 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5772 {
5773 	struct ext4_fs_context *ctx = fc->fs_private;
5774 	struct ext4_sb_info *sbi;
5775 	const char *descr;
5776 	int ret;
5777 
5778 	sbi = ext4_alloc_sbi(sb);
5779 	if (!sbi)
5780 		return -ENOMEM;
5781 
5782 	fc->s_fs_info = sbi;
5783 
5784 	/* Cleanup superblock name */
5785 	strreplace(sb->s_id, '/', '!');
5786 
5787 	sbi->s_sb_block = 1;	/* Default super block location */
5788 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5789 		sbi->s_sb_block = ctx->s_sb_block;
5790 
5791 	ret = __ext4_fill_super(fc, sb);
5792 	if (ret < 0)
5793 		goto free_sbi;
5794 
5795 	if (sbi->s_journal) {
5796 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5797 			descr = " journalled data mode";
5798 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5799 			descr = " ordered data mode";
5800 		else
5801 			descr = " writeback data mode";
5802 	} else
5803 		descr = "out journal";
5804 
5805 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5806 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5807 			 "Quota mode: %s.", &sb->s_uuid,
5808 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5809 			 ext4_quota_mode(sb));
5810 
5811 	/* Update the s_overhead_clusters if necessary */
5812 	ext4_update_overhead(sb, false);
5813 	return 0;
5814 
5815 free_sbi:
5816 	ext4_free_sbi(sbi);
5817 	fc->s_fs_info = NULL;
5818 	return ret;
5819 }
5820 
5821 static int ext4_get_tree(struct fs_context *fc)
5822 {
5823 	return get_tree_bdev(fc, ext4_fill_super);
5824 }
5825 
5826 /*
5827  * Setup any per-fs journal parameters now.  We'll do this both on
5828  * initial mount, once the journal has been initialised but before we've
5829  * done any recovery; and again on any subsequent remount.
5830  */
5831 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5832 {
5833 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5834 
5835 	journal->j_commit_interval = sbi->s_commit_interval;
5836 	journal->j_min_batch_time = sbi->s_min_batch_time;
5837 	journal->j_max_batch_time = sbi->s_max_batch_time;
5838 	ext4_fc_init(sb, journal);
5839 
5840 	write_lock(&journal->j_state_lock);
5841 	if (test_opt(sb, BARRIER))
5842 		journal->j_flags |= JBD2_BARRIER;
5843 	else
5844 		journal->j_flags &= ~JBD2_BARRIER;
5845 	/*
5846 	 * Always enable journal cycle record option, letting the journal
5847 	 * records log transactions continuously between each mount.
5848 	 */
5849 	journal->j_flags |= JBD2_CYCLE_RECORD;
5850 	write_unlock(&journal->j_state_lock);
5851 }
5852 
5853 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5854 					     unsigned int journal_inum)
5855 {
5856 	struct inode *journal_inode;
5857 
5858 	/*
5859 	 * Test for the existence of a valid inode on disk.  Bad things
5860 	 * happen if we iget() an unused inode, as the subsequent iput()
5861 	 * will try to delete it.
5862 	 */
5863 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5864 	if (IS_ERR(journal_inode)) {
5865 		ext4_msg(sb, KERN_ERR, "no journal found");
5866 		return ERR_CAST(journal_inode);
5867 	}
5868 	if (!journal_inode->i_nlink) {
5869 		make_bad_inode(journal_inode);
5870 		iput(journal_inode);
5871 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5872 		return ERR_PTR(-EFSCORRUPTED);
5873 	}
5874 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5875 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5876 		iput(journal_inode);
5877 		return ERR_PTR(-EFSCORRUPTED);
5878 	}
5879 
5880 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5881 		  journal_inode, journal_inode->i_size);
5882 	return journal_inode;
5883 }
5884 
5885 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5886 {
5887 	struct ext4_map_blocks map;
5888 	int ret;
5889 
5890 	if (journal->j_inode == NULL)
5891 		return 0;
5892 
5893 	map.m_lblk = *block;
5894 	map.m_len = 1;
5895 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5896 	if (ret <= 0) {
5897 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5898 			 "journal bmap failed: block %llu ret %d\n",
5899 			 *block, ret);
5900 		jbd2_journal_abort(journal, ret ? ret : -EFSCORRUPTED);
5901 		return ret;
5902 	}
5903 	*block = map.m_pblk;
5904 	return 0;
5905 }
5906 
5907 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5908 					  unsigned int journal_inum)
5909 {
5910 	struct inode *journal_inode;
5911 	journal_t *journal;
5912 
5913 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5914 	if (IS_ERR(journal_inode))
5915 		return ERR_CAST(journal_inode);
5916 
5917 	journal = jbd2_journal_init_inode(journal_inode);
5918 	if (IS_ERR(journal)) {
5919 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5920 		iput(journal_inode);
5921 		return ERR_CAST(journal);
5922 	}
5923 	journal->j_private = sb;
5924 	journal->j_bmap = ext4_journal_bmap;
5925 	ext4_init_journal_params(sb, journal);
5926 	return journal;
5927 }
5928 
5929 static struct file *ext4_get_journal_blkdev(struct super_block *sb,
5930 					dev_t j_dev, ext4_fsblk_t *j_start,
5931 					ext4_fsblk_t *j_len)
5932 {
5933 	struct buffer_head *bh;
5934 	struct block_device *bdev;
5935 	struct file *bdev_file;
5936 	int hblock, blocksize;
5937 	ext4_fsblk_t sb_block;
5938 	unsigned long offset;
5939 	struct ext4_super_block *es;
5940 	int errno;
5941 
5942 	bdev_file = bdev_file_open_by_dev(j_dev,
5943 		BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
5944 		sb, &fs_holder_ops);
5945 	if (IS_ERR(bdev_file)) {
5946 		ext4_msg(sb, KERN_ERR,
5947 			 "failed to open journal device unknown-block(%u,%u) %ld",
5948 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev_file));
5949 		return bdev_file;
5950 	}
5951 
5952 	bdev = file_bdev(bdev_file);
5953 	blocksize = sb->s_blocksize;
5954 	hblock = bdev_logical_block_size(bdev);
5955 	if (blocksize < hblock) {
5956 		ext4_msg(sb, KERN_ERR,
5957 			"blocksize too small for journal device");
5958 		errno = -EINVAL;
5959 		goto out_bdev;
5960 	}
5961 
5962 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5963 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5964 	set_blocksize(bdev_file, blocksize);
5965 	bh = __bread(bdev, sb_block, blocksize);
5966 	if (!bh) {
5967 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5968 		       "external journal");
5969 		errno = -EINVAL;
5970 		goto out_bdev;
5971 	}
5972 
5973 	es = (struct ext4_super_block *) (bh->b_data + offset);
5974 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5975 	    !(le32_to_cpu(es->s_feature_incompat) &
5976 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5977 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
5978 		errno = -EFSCORRUPTED;
5979 		goto out_bh;
5980 	}
5981 
5982 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5983 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5984 	    es->s_checksum != ext4_superblock_csum(es)) {
5985 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
5986 		errno = -EFSCORRUPTED;
5987 		goto out_bh;
5988 	}
5989 
5990 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5991 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5992 		errno = -EFSCORRUPTED;
5993 		goto out_bh;
5994 	}
5995 
5996 	*j_start = sb_block + 1;
5997 	*j_len = ext4_blocks_count(es);
5998 	brelse(bh);
5999 	return bdev_file;
6000 
6001 out_bh:
6002 	brelse(bh);
6003 out_bdev:
6004 	bdev_fput(bdev_file);
6005 	return ERR_PTR(errno);
6006 }
6007 
6008 static journal_t *ext4_open_dev_journal(struct super_block *sb,
6009 					dev_t j_dev)
6010 {
6011 	journal_t *journal;
6012 	ext4_fsblk_t j_start;
6013 	ext4_fsblk_t j_len;
6014 	struct file *bdev_file;
6015 	int errno = 0;
6016 
6017 	bdev_file = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
6018 	if (IS_ERR(bdev_file))
6019 		return ERR_CAST(bdev_file);
6020 
6021 	journal = jbd2_journal_init_dev(file_bdev(bdev_file), sb->s_bdev, j_start,
6022 					j_len, sb->s_blocksize);
6023 	if (IS_ERR(journal)) {
6024 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
6025 		errno = PTR_ERR(journal);
6026 		goto out_bdev;
6027 	}
6028 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
6029 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
6030 					"user (unsupported) - %d",
6031 			be32_to_cpu(journal->j_superblock->s_nr_users));
6032 		errno = -EINVAL;
6033 		goto out_journal;
6034 	}
6035 	journal->j_private = sb;
6036 	EXT4_SB(sb)->s_journal_bdev_file = bdev_file;
6037 	ext4_init_journal_params(sb, journal);
6038 	return journal;
6039 
6040 out_journal:
6041 	ext4_journal_destroy(EXT4_SB(sb), journal);
6042 out_bdev:
6043 	bdev_fput(bdev_file);
6044 	return ERR_PTR(errno);
6045 }
6046 
6047 static int ext4_load_journal(struct super_block *sb,
6048 			     struct ext4_super_block *es,
6049 			     unsigned long journal_devnum)
6050 {
6051 	journal_t *journal;
6052 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
6053 	dev_t journal_dev;
6054 	int err = 0;
6055 	int really_read_only;
6056 	int journal_dev_ro;
6057 
6058 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
6059 		return -EFSCORRUPTED;
6060 
6061 	if (journal_devnum &&
6062 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6063 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
6064 			"numbers have changed");
6065 		journal_dev = new_decode_dev(journal_devnum);
6066 	} else
6067 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
6068 
6069 	if (journal_inum && journal_dev) {
6070 		ext4_msg(sb, KERN_ERR,
6071 			 "filesystem has both journal inode and journal device!");
6072 		return -EINVAL;
6073 	}
6074 
6075 	if (journal_inum) {
6076 		journal = ext4_open_inode_journal(sb, journal_inum);
6077 		if (IS_ERR(journal))
6078 			return PTR_ERR(journal);
6079 	} else {
6080 		journal = ext4_open_dev_journal(sb, journal_dev);
6081 		if (IS_ERR(journal))
6082 			return PTR_ERR(journal);
6083 	}
6084 
6085 	journal_dev_ro = bdev_read_only(journal->j_dev);
6086 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
6087 
6088 	if (journal_dev_ro && !sb_rdonly(sb)) {
6089 		ext4_msg(sb, KERN_ERR,
6090 			 "journal device read-only, try mounting with '-o ro'");
6091 		err = -EROFS;
6092 		goto err_out;
6093 	}
6094 
6095 	/*
6096 	 * Are we loading a blank journal or performing recovery after a
6097 	 * crash?  For recovery, we need to check in advance whether we
6098 	 * can get read-write access to the device.
6099 	 */
6100 	if (ext4_has_feature_journal_needs_recovery(sb)) {
6101 		if (sb_rdonly(sb)) {
6102 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
6103 					"required on readonly filesystem");
6104 			if (really_read_only) {
6105 				ext4_msg(sb, KERN_ERR, "write access "
6106 					"unavailable, cannot proceed "
6107 					"(try mounting with noload)");
6108 				err = -EROFS;
6109 				goto err_out;
6110 			}
6111 			ext4_msg(sb, KERN_INFO, "write access will "
6112 			       "be enabled during recovery");
6113 		}
6114 	}
6115 
6116 	if (!(journal->j_flags & JBD2_BARRIER))
6117 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6118 
6119 	if (!ext4_has_feature_journal_needs_recovery(sb))
6120 		err = jbd2_journal_wipe(journal, !really_read_only);
6121 	if (!err) {
6122 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6123 		__le16 orig_state;
6124 		bool changed = false;
6125 
6126 		if (save)
6127 			memcpy(save, ((char *) es) +
6128 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6129 		err = jbd2_journal_load(journal);
6130 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6131 				   save, EXT4_S_ERR_LEN)) {
6132 			memcpy(((char *) es) + EXT4_S_ERR_START,
6133 			       save, EXT4_S_ERR_LEN);
6134 			changed = true;
6135 		}
6136 		kfree(save);
6137 		orig_state = es->s_state;
6138 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6139 					   EXT4_ERROR_FS);
6140 		if (orig_state != es->s_state)
6141 			changed = true;
6142 		/* Write out restored error information to the superblock */
6143 		if (changed && !really_read_only) {
6144 			int err2;
6145 			err2 = ext4_commit_super(sb);
6146 			err = err ? : err2;
6147 		}
6148 	}
6149 
6150 	if (err) {
6151 		ext4_msg(sb, KERN_ERR, "error loading journal");
6152 		goto err_out;
6153 	}
6154 
6155 	EXT4_SB(sb)->s_journal = journal;
6156 	err = ext4_clear_journal_err(sb, es);
6157 	if (err) {
6158 		ext4_journal_destroy(EXT4_SB(sb), journal);
6159 		return err;
6160 	}
6161 
6162 	if (!really_read_only && journal_devnum &&
6163 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6164 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6165 		ext4_commit_super(sb);
6166 	}
6167 	if (!really_read_only && journal_inum &&
6168 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6169 		es->s_journal_inum = cpu_to_le32(journal_inum);
6170 		ext4_commit_super(sb);
6171 	}
6172 
6173 	return 0;
6174 
6175 err_out:
6176 	ext4_journal_destroy(EXT4_SB(sb), journal);
6177 	return err;
6178 }
6179 
6180 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6181 static void ext4_update_super(struct super_block *sb)
6182 {
6183 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6184 	struct ext4_super_block *es = sbi->s_es;
6185 	struct buffer_head *sbh = sbi->s_sbh;
6186 
6187 	lock_buffer(sbh);
6188 	/*
6189 	 * If the file system is mounted read-only, don't update the
6190 	 * superblock write time.  This avoids updating the superblock
6191 	 * write time when we are mounting the root file system
6192 	 * read/only but we need to replay the journal; at that point,
6193 	 * for people who are east of GMT and who make their clock
6194 	 * tick in localtime for Windows bug-for-bug compatibility,
6195 	 * the clock is set in the future, and this will cause e2fsck
6196 	 * to complain and force a full file system check.
6197 	 */
6198 	if (!sb_rdonly(sb))
6199 		ext4_update_tstamp(es, s_wtime);
6200 	es->s_kbytes_written =
6201 		cpu_to_le64(sbi->s_kbytes_written +
6202 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6203 		      sbi->s_sectors_written_start) >> 1));
6204 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6205 		ext4_free_blocks_count_set(es,
6206 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6207 				&sbi->s_freeclusters_counter)));
6208 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6209 		es->s_free_inodes_count =
6210 			cpu_to_le32(percpu_counter_sum_positive(
6211 				&sbi->s_freeinodes_counter));
6212 	/* Copy error information to the on-disk superblock */
6213 	spin_lock(&sbi->s_error_lock);
6214 	if (sbi->s_add_error_count > 0) {
6215 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6216 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6217 			__ext4_update_tstamp(&es->s_first_error_time,
6218 					     &es->s_first_error_time_hi,
6219 					     sbi->s_first_error_time);
6220 			strtomem_pad(es->s_first_error_func,
6221 				     sbi->s_first_error_func, 0);
6222 			es->s_first_error_line =
6223 				cpu_to_le32(sbi->s_first_error_line);
6224 			es->s_first_error_ino =
6225 				cpu_to_le32(sbi->s_first_error_ino);
6226 			es->s_first_error_block =
6227 				cpu_to_le64(sbi->s_first_error_block);
6228 			es->s_first_error_errcode =
6229 				ext4_errno_to_code(sbi->s_first_error_code);
6230 		}
6231 		__ext4_update_tstamp(&es->s_last_error_time,
6232 				     &es->s_last_error_time_hi,
6233 				     sbi->s_last_error_time);
6234 		strtomem_pad(es->s_last_error_func, sbi->s_last_error_func, 0);
6235 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6236 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6237 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6238 		es->s_last_error_errcode =
6239 				ext4_errno_to_code(sbi->s_last_error_code);
6240 		/*
6241 		 * Start the daily error reporting function if it hasn't been
6242 		 * started already and sbi->s_err_report_sec is not zero
6243 		 */
6244 		if (!es->s_error_count && !sbi->s_err_report_sec)
6245 			mod_timer(&sbi->s_err_report,
6246 					  jiffies + secs_to_jiffies(sbi->s_err_report_sec));
6247 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6248 		sbi->s_add_error_count = 0;
6249 	}
6250 	spin_unlock(&sbi->s_error_lock);
6251 
6252 	ext4_superblock_csum_set(sb);
6253 	unlock_buffer(sbh);
6254 }
6255 
6256 static int ext4_commit_super(struct super_block *sb)
6257 {
6258 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6259 
6260 	if (!sbh)
6261 		return -EINVAL;
6262 
6263 	ext4_update_super(sb);
6264 
6265 	lock_buffer(sbh);
6266 	/* Buffer got discarded which means block device got invalidated */
6267 	if (!buffer_mapped(sbh)) {
6268 		unlock_buffer(sbh);
6269 		return -EIO;
6270 	}
6271 
6272 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6273 		/*
6274 		 * Oh, dear.  A previous attempt to write the
6275 		 * superblock failed.  This could happen because the
6276 		 * USB device was yanked out.  Or it could happen to
6277 		 * be a transient write error and maybe the block will
6278 		 * be remapped.  Nothing we can do but to retry the
6279 		 * write and hope for the best.
6280 		 */
6281 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6282 		       "superblock detected");
6283 		clear_buffer_write_io_error(sbh);
6284 		set_buffer_uptodate(sbh);
6285 	}
6286 	get_bh(sbh);
6287 	/* Clear potential dirty bit if it was journalled update */
6288 	clear_buffer_dirty(sbh);
6289 	sbh->b_end_io = end_buffer_write_sync;
6290 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6291 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6292 	wait_on_buffer(sbh);
6293 	if (buffer_write_io_error(sbh)) {
6294 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6295 		       "superblock");
6296 		clear_buffer_write_io_error(sbh);
6297 		set_buffer_uptodate(sbh);
6298 		return -EIO;
6299 	}
6300 	return 0;
6301 }
6302 
6303 /*
6304  * Have we just finished recovery?  If so, and if we are mounting (or
6305  * remounting) the filesystem readonly, then we will end up with a
6306  * consistent fs on disk.  Record that fact.
6307  */
6308 static int ext4_mark_recovery_complete(struct super_block *sb,
6309 				       struct ext4_super_block *es)
6310 {
6311 	int err;
6312 	journal_t *journal = EXT4_SB(sb)->s_journal;
6313 
6314 	if (!ext4_has_feature_journal(sb)) {
6315 		if (journal != NULL) {
6316 			ext4_error(sb, "Journal got removed while the fs was "
6317 				   "mounted!");
6318 			return -EFSCORRUPTED;
6319 		}
6320 		return 0;
6321 	}
6322 	jbd2_journal_lock_updates(journal);
6323 	err = jbd2_journal_flush(journal, 0);
6324 	if (err < 0)
6325 		goto out;
6326 
6327 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6328 	    ext4_has_feature_orphan_present(sb))) {
6329 		if (!ext4_orphan_file_empty(sb)) {
6330 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6331 			err = -EFSCORRUPTED;
6332 			goto out;
6333 		}
6334 		ext4_clear_feature_journal_needs_recovery(sb);
6335 		ext4_clear_feature_orphan_present(sb);
6336 		ext4_commit_super(sb);
6337 	}
6338 out:
6339 	jbd2_journal_unlock_updates(journal);
6340 	return err;
6341 }
6342 
6343 /*
6344  * If we are mounting (or read-write remounting) a filesystem whose journal
6345  * has recorded an error from a previous lifetime, move that error to the
6346  * main filesystem now.
6347  */
6348 static int ext4_clear_journal_err(struct super_block *sb,
6349 				   struct ext4_super_block *es)
6350 {
6351 	journal_t *journal;
6352 	int j_errno;
6353 	const char *errstr;
6354 
6355 	if (!ext4_has_feature_journal(sb)) {
6356 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6357 		return -EFSCORRUPTED;
6358 	}
6359 
6360 	journal = EXT4_SB(sb)->s_journal;
6361 
6362 	/*
6363 	 * Now check for any error status which may have been recorded in the
6364 	 * journal by a prior ext4_error() or ext4_abort()
6365 	 */
6366 
6367 	j_errno = jbd2_journal_errno(journal);
6368 	if (j_errno) {
6369 		char nbuf[16];
6370 
6371 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6372 		ext4_warning(sb, "Filesystem error recorded "
6373 			     "from previous mount: %s", errstr);
6374 
6375 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6376 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6377 		j_errno = ext4_commit_super(sb);
6378 		if (j_errno)
6379 			return j_errno;
6380 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6381 
6382 		jbd2_journal_clear_err(journal);
6383 		jbd2_journal_update_sb_errno(journal);
6384 	}
6385 	return 0;
6386 }
6387 
6388 /*
6389  * Force the running and committing transactions to commit,
6390  * and wait on the commit.
6391  */
6392 int ext4_force_commit(struct super_block *sb)
6393 {
6394 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6395 }
6396 
6397 static int ext4_sync_fs(struct super_block *sb, int wait)
6398 {
6399 	int ret = 0;
6400 	tid_t target;
6401 	bool needs_barrier = false;
6402 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6403 
6404 	ret = ext4_emergency_state(sb);
6405 	if (unlikely(ret))
6406 		return ret;
6407 
6408 	trace_ext4_sync_fs(sb, wait);
6409 	flush_workqueue(sbi->rsv_conversion_wq);
6410 	/*
6411 	 * Writeback quota in non-journalled quota case - journalled quota has
6412 	 * no dirty dquots
6413 	 */
6414 	dquot_writeback_dquots(sb, -1);
6415 	/*
6416 	 * Data writeback is possible w/o journal transaction, so barrier must
6417 	 * being sent at the end of the function. But we can skip it if
6418 	 * transaction_commit will do it for us.
6419 	 */
6420 	if (sbi->s_journal) {
6421 		target = jbd2_get_latest_transaction(sbi->s_journal);
6422 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6423 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6424 			needs_barrier = true;
6425 
6426 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6427 			if (wait)
6428 				ret = jbd2_log_wait_commit(sbi->s_journal,
6429 							   target);
6430 		}
6431 	} else if (wait && test_opt(sb, BARRIER))
6432 		needs_barrier = true;
6433 	if (needs_barrier) {
6434 		int err;
6435 		err = blkdev_issue_flush(sb->s_bdev);
6436 		if (!ret)
6437 			ret = err;
6438 	}
6439 
6440 	return ret;
6441 }
6442 
6443 /*
6444  * LVM calls this function before a (read-only) snapshot is created.  This
6445  * gives us a chance to flush the journal completely and mark the fs clean.
6446  *
6447  * Note that only this function cannot bring a filesystem to be in a clean
6448  * state independently. It relies on upper layer to stop all data & metadata
6449  * modifications.
6450  */
6451 static int ext4_freeze(struct super_block *sb)
6452 {
6453 	int error = 0;
6454 	journal_t *journal = EXT4_SB(sb)->s_journal;
6455 
6456 	if (journal) {
6457 		/* Now we set up the journal barrier. */
6458 		jbd2_journal_lock_updates(journal);
6459 
6460 		/*
6461 		 * Don't clear the needs_recovery flag if we failed to
6462 		 * flush the journal.
6463 		 */
6464 		error = jbd2_journal_flush(journal, 0);
6465 		if (error < 0)
6466 			goto out;
6467 
6468 		/* Journal blocked and flushed, clear needs_recovery flag. */
6469 		ext4_clear_feature_journal_needs_recovery(sb);
6470 		if (ext4_orphan_file_empty(sb))
6471 			ext4_clear_feature_orphan_present(sb);
6472 	}
6473 
6474 	error = ext4_commit_super(sb);
6475 out:
6476 	if (journal)
6477 		/* we rely on upper layer to stop further updates */
6478 		jbd2_journal_unlock_updates(journal);
6479 	return error;
6480 }
6481 
6482 /*
6483  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6484  * flag here, even though the filesystem is not technically dirty yet.
6485  */
6486 static int ext4_unfreeze(struct super_block *sb)
6487 {
6488 	if (ext4_emergency_state(sb))
6489 		return 0;
6490 
6491 	if (EXT4_SB(sb)->s_journal) {
6492 		/* Reset the needs_recovery flag before the fs is unlocked. */
6493 		ext4_set_feature_journal_needs_recovery(sb);
6494 		if (ext4_has_feature_orphan_file(sb))
6495 			ext4_set_feature_orphan_present(sb);
6496 	}
6497 
6498 	ext4_commit_super(sb);
6499 	return 0;
6500 }
6501 
6502 /*
6503  * Structure to save mount options for ext4_remount's benefit
6504  */
6505 struct ext4_mount_options {
6506 	unsigned long s_mount_opt;
6507 	unsigned long s_mount_opt2;
6508 	kuid_t s_resuid;
6509 	kgid_t s_resgid;
6510 	unsigned long s_commit_interval;
6511 	u32 s_min_batch_time, s_max_batch_time;
6512 #ifdef CONFIG_QUOTA
6513 	int s_jquota_fmt;
6514 	char *s_qf_names[EXT4_MAXQUOTAS];
6515 #endif
6516 };
6517 
6518 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6519 {
6520 	struct ext4_fs_context *ctx = fc->fs_private;
6521 	struct ext4_super_block *es;
6522 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6523 	unsigned long old_sb_flags;
6524 	struct ext4_mount_options old_opts;
6525 	ext4_group_t g;
6526 	int err = 0;
6527 	int alloc_ctx;
6528 #ifdef CONFIG_QUOTA
6529 	int enable_quota = 0;
6530 	int i, j;
6531 	char *to_free[EXT4_MAXQUOTAS];
6532 #endif
6533 
6534 
6535 	/* Store the original options */
6536 	old_sb_flags = sb->s_flags;
6537 	old_opts.s_mount_opt = sbi->s_mount_opt;
6538 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6539 	old_opts.s_resuid = sbi->s_resuid;
6540 	old_opts.s_resgid = sbi->s_resgid;
6541 	old_opts.s_commit_interval = sbi->s_commit_interval;
6542 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6543 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6544 #ifdef CONFIG_QUOTA
6545 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6546 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6547 		if (sbi->s_qf_names[i]) {
6548 			char *qf_name = get_qf_name(sb, sbi, i);
6549 
6550 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6551 			if (!old_opts.s_qf_names[i]) {
6552 				for (j = 0; j < i; j++)
6553 					kfree(old_opts.s_qf_names[j]);
6554 				return -ENOMEM;
6555 			}
6556 		} else
6557 			old_opts.s_qf_names[i] = NULL;
6558 #endif
6559 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6560 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6561 			ctx->journal_ioprio =
6562 				sbi->s_journal->j_task->io_context->ioprio;
6563 		else
6564 			ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
6565 
6566 	}
6567 
6568 	if ((ctx->spec & EXT4_SPEC_s_stripe) &&
6569 	    ext4_is_stripe_incompatible(sb, ctx->s_stripe)) {
6570 		ext4_msg(sb, KERN_WARNING,
6571 			 "stripe (%lu) is not aligned with cluster size (%u), "
6572 			 "stripe is disabled",
6573 			 ctx->s_stripe, sbi->s_cluster_ratio);
6574 		ctx->s_stripe = 0;
6575 	}
6576 
6577 	/*
6578 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6579 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6580 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6581 	 * here s_writepages_rwsem to avoid race between writepages ops and
6582 	 * remount.
6583 	 */
6584 	alloc_ctx = ext4_writepages_down_write(sb);
6585 	ext4_apply_options(fc, sb);
6586 	ext4_writepages_up_write(sb, alloc_ctx);
6587 
6588 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6589 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6590 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6591 			 "during remount not supported; ignoring");
6592 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6593 	}
6594 
6595 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6596 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6597 			ext4_msg(sb, KERN_ERR, "can't mount with "
6598 				 "both data=journal and delalloc");
6599 			err = -EINVAL;
6600 			goto restore_opts;
6601 		}
6602 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6603 			ext4_msg(sb, KERN_ERR, "can't mount with "
6604 				 "both data=journal and dioread_nolock");
6605 			err = -EINVAL;
6606 			goto restore_opts;
6607 		}
6608 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6609 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6610 			ext4_msg(sb, KERN_ERR, "can't mount with "
6611 				"journal_async_commit in data=ordered mode");
6612 			err = -EINVAL;
6613 			goto restore_opts;
6614 		}
6615 	}
6616 
6617 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6618 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6619 		err = -EINVAL;
6620 		goto restore_opts;
6621 	}
6622 
6623 	if ((old_opts.s_mount_opt & EXT4_MOUNT_DELALLOC) &&
6624 	    !test_opt(sb, DELALLOC)) {
6625 		ext4_msg(sb, KERN_ERR, "can't disable delalloc during remount");
6626 		err = -EINVAL;
6627 		goto restore_opts;
6628 	}
6629 
6630 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6631 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6632 
6633 	es = sbi->s_es;
6634 
6635 	if (sbi->s_journal) {
6636 		ext4_init_journal_params(sb, sbi->s_journal);
6637 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6638 	}
6639 
6640 	/* Flush outstanding errors before changing fs state */
6641 	flush_work(&sbi->s_sb_upd_work);
6642 
6643 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6644 		if (ext4_emergency_state(sb)) {
6645 			err = -EROFS;
6646 			goto restore_opts;
6647 		}
6648 
6649 		if (fc->sb_flags & SB_RDONLY) {
6650 			err = sync_filesystem(sb);
6651 			if (err < 0)
6652 				goto restore_opts;
6653 			err = dquot_suspend(sb, -1);
6654 			if (err < 0)
6655 				goto restore_opts;
6656 
6657 			/*
6658 			 * First of all, the unconditional stuff we have to do
6659 			 * to disable replay of the journal when we next remount
6660 			 */
6661 			sb->s_flags |= SB_RDONLY;
6662 
6663 			/*
6664 			 * OK, test if we are remounting a valid rw partition
6665 			 * readonly, and if so set the rdonly flag and then
6666 			 * mark the partition as valid again.
6667 			 */
6668 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6669 			    (sbi->s_mount_state & EXT4_VALID_FS))
6670 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6671 
6672 			if (sbi->s_journal) {
6673 				/*
6674 				 * We let remount-ro finish even if marking fs
6675 				 * as clean failed...
6676 				 */
6677 				ext4_mark_recovery_complete(sb, es);
6678 			}
6679 		} else {
6680 			/* Make sure we can mount this feature set readwrite */
6681 			if (ext4_has_feature_readonly(sb) ||
6682 			    !ext4_feature_set_ok(sb, 0)) {
6683 				err = -EROFS;
6684 				goto restore_opts;
6685 			}
6686 			/*
6687 			 * Make sure the group descriptor checksums
6688 			 * are sane.  If they aren't, refuse to remount r/w.
6689 			 */
6690 			for (g = 0; g < sbi->s_groups_count; g++) {
6691 				struct ext4_group_desc *gdp =
6692 					ext4_get_group_desc(sb, g, NULL);
6693 
6694 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6695 					ext4_msg(sb, KERN_ERR,
6696 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6697 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6698 					       le16_to_cpu(gdp->bg_checksum));
6699 					err = -EFSBADCRC;
6700 					goto restore_opts;
6701 				}
6702 			}
6703 
6704 			/*
6705 			 * If we have an unprocessed orphan list hanging
6706 			 * around from a previously readonly bdev mount,
6707 			 * require a full umount/remount for now.
6708 			 */
6709 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6710 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6711 				       "remount RDWR because of unprocessed "
6712 				       "orphan inode list.  Please "
6713 				       "umount/remount instead");
6714 				err = -EINVAL;
6715 				goto restore_opts;
6716 			}
6717 
6718 			/*
6719 			 * Mounting a RDONLY partition read-write, so reread
6720 			 * and store the current valid flag.  (It may have
6721 			 * been changed by e2fsck since we originally mounted
6722 			 * the partition.)
6723 			 */
6724 			if (sbi->s_journal) {
6725 				err = ext4_clear_journal_err(sb, es);
6726 				if (err)
6727 					goto restore_opts;
6728 			}
6729 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6730 					      ~EXT4_FC_REPLAY);
6731 
6732 			err = ext4_setup_super(sb, es, 0);
6733 			if (err)
6734 				goto restore_opts;
6735 
6736 			sb->s_flags &= ~SB_RDONLY;
6737 			if (ext4_has_feature_mmp(sb)) {
6738 				err = ext4_multi_mount_protect(sb,
6739 						le64_to_cpu(es->s_mmp_block));
6740 				if (err)
6741 					goto restore_opts;
6742 			}
6743 #ifdef CONFIG_QUOTA
6744 			enable_quota = 1;
6745 #endif
6746 		}
6747 	}
6748 
6749 	/*
6750 	 * Handle creation of system zone data early because it can fail.
6751 	 * Releasing of existing data is done when we are sure remount will
6752 	 * succeed.
6753 	 */
6754 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6755 		err = ext4_setup_system_zone(sb);
6756 		if (err)
6757 			goto restore_opts;
6758 	}
6759 
6760 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6761 		err = ext4_commit_super(sb);
6762 		if (err)
6763 			goto restore_opts;
6764 	}
6765 
6766 #ifdef CONFIG_QUOTA
6767 	if (enable_quota) {
6768 		if (sb_any_quota_suspended(sb))
6769 			dquot_resume(sb, -1);
6770 		else if (ext4_has_feature_quota(sb)) {
6771 			err = ext4_enable_quotas(sb);
6772 			if (err)
6773 				goto restore_opts;
6774 		}
6775 	}
6776 	/* Release old quota file names */
6777 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6778 		kfree(old_opts.s_qf_names[i]);
6779 #endif
6780 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6781 		ext4_release_system_zone(sb);
6782 
6783 	/*
6784 	 * Reinitialize lazy itable initialization thread based on
6785 	 * current settings
6786 	 */
6787 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6788 		ext4_unregister_li_request(sb);
6789 	else {
6790 		ext4_group_t first_not_zeroed;
6791 		first_not_zeroed = ext4_has_uninit_itable(sb);
6792 		ext4_register_li_request(sb, first_not_zeroed);
6793 	}
6794 
6795 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6796 		ext4_stop_mmpd(sbi);
6797 
6798 	/*
6799 	 * Handle aborting the filesystem as the last thing during remount to
6800 	 * avoid obsure errors during remount when some option changes fail to
6801 	 * apply due to shutdown filesystem.
6802 	 */
6803 	if (test_opt2(sb, ABORT))
6804 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6805 
6806 	return 0;
6807 
6808 restore_opts:
6809 	/*
6810 	 * If there was a failing r/w to ro transition, we may need to
6811 	 * re-enable quota
6812 	 */
6813 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6814 	    sb_any_quota_suspended(sb))
6815 		dquot_resume(sb, -1);
6816 
6817 	alloc_ctx = ext4_writepages_down_write(sb);
6818 	sb->s_flags = old_sb_flags;
6819 	sbi->s_mount_opt = old_opts.s_mount_opt;
6820 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6821 	sbi->s_resuid = old_opts.s_resuid;
6822 	sbi->s_resgid = old_opts.s_resgid;
6823 	sbi->s_commit_interval = old_opts.s_commit_interval;
6824 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6825 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6826 	ext4_writepages_up_write(sb, alloc_ctx);
6827 
6828 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6829 		ext4_release_system_zone(sb);
6830 #ifdef CONFIG_QUOTA
6831 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6832 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6833 		to_free[i] = get_qf_name(sb, sbi, i);
6834 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6835 	}
6836 	synchronize_rcu();
6837 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6838 		kfree(to_free[i]);
6839 #endif
6840 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6841 		ext4_stop_mmpd(sbi);
6842 	return err;
6843 }
6844 
6845 static int ext4_reconfigure(struct fs_context *fc)
6846 {
6847 	struct super_block *sb = fc->root->d_sb;
6848 	int ret;
6849 	bool old_ro = sb_rdonly(sb);
6850 
6851 	fc->s_fs_info = EXT4_SB(sb);
6852 
6853 	ret = ext4_check_opt_consistency(fc, sb);
6854 	if (ret < 0)
6855 		return ret;
6856 
6857 	ret = __ext4_remount(fc, sb);
6858 	if (ret < 0)
6859 		return ret;
6860 
6861 	ext4_msg(sb, KERN_INFO, "re-mounted %pU%s.",
6862 		 &sb->s_uuid,
6863 		 (old_ro != sb_rdonly(sb)) ? (sb_rdonly(sb) ? " ro" : " r/w") : "");
6864 
6865 	return 0;
6866 }
6867 
6868 #ifdef CONFIG_QUOTA
6869 static int ext4_statfs_project(struct super_block *sb,
6870 			       kprojid_t projid, struct kstatfs *buf)
6871 {
6872 	struct kqid qid;
6873 	struct dquot *dquot;
6874 	u64 limit;
6875 	u64 curblock;
6876 
6877 	qid = make_kqid_projid(projid);
6878 	dquot = dqget(sb, qid);
6879 	if (IS_ERR(dquot))
6880 		return PTR_ERR(dquot);
6881 	spin_lock(&dquot->dq_dqb_lock);
6882 
6883 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6884 			     dquot->dq_dqb.dqb_bhardlimit);
6885 	limit >>= sb->s_blocksize_bits;
6886 
6887 	if (limit) {
6888 		uint64_t	remaining = 0;
6889 
6890 		curblock = (dquot->dq_dqb.dqb_curspace +
6891 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6892 		if (limit > curblock)
6893 			remaining = limit - curblock;
6894 
6895 		buf->f_blocks = min(buf->f_blocks, limit);
6896 		buf->f_bfree = min(buf->f_bfree, remaining);
6897 		buf->f_bavail = min(buf->f_bavail, remaining);
6898 	}
6899 
6900 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6901 			     dquot->dq_dqb.dqb_ihardlimit);
6902 	if (limit) {
6903 		uint64_t	remaining = 0;
6904 
6905 		if (limit > dquot->dq_dqb.dqb_curinodes)
6906 			remaining = limit - dquot->dq_dqb.dqb_curinodes;
6907 
6908 		buf->f_files = min(buf->f_files, limit);
6909 		buf->f_ffree = min(buf->f_ffree, remaining);
6910 	}
6911 
6912 	spin_unlock(&dquot->dq_dqb_lock);
6913 	dqput(dquot);
6914 	return 0;
6915 }
6916 #endif
6917 
6918 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6919 {
6920 	struct super_block *sb = dentry->d_sb;
6921 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6922 	struct ext4_super_block *es = sbi->s_es;
6923 	ext4_fsblk_t overhead = 0, resv_blocks;
6924 	s64 bfree;
6925 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6926 
6927 	if (!test_opt(sb, MINIX_DF))
6928 		overhead = sbi->s_overhead;
6929 
6930 	buf->f_type = EXT4_SUPER_MAGIC;
6931 	buf->f_bsize = sb->s_blocksize;
6932 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6933 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6934 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6935 	/* prevent underflow in case that few free space is available */
6936 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6937 	buf->f_bavail = buf->f_bfree -
6938 			(ext4_r_blocks_count(es) + resv_blocks);
6939 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6940 		buf->f_bavail = 0;
6941 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6942 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6943 	buf->f_namelen = EXT4_NAME_LEN;
6944 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6945 
6946 #ifdef CONFIG_QUOTA
6947 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6948 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6949 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6950 #endif
6951 	return 0;
6952 }
6953 
6954 
6955 #ifdef CONFIG_QUOTA
6956 
6957 /*
6958  * Helper functions so that transaction is started before we acquire dqio_sem
6959  * to keep correct lock ordering of transaction > dqio_sem
6960  */
6961 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6962 {
6963 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6964 }
6965 
6966 static int ext4_write_dquot(struct dquot *dquot)
6967 {
6968 	int ret, err;
6969 	handle_t *handle;
6970 	struct inode *inode;
6971 
6972 	inode = dquot_to_inode(dquot);
6973 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6974 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6975 	if (IS_ERR(handle))
6976 		return PTR_ERR(handle);
6977 	ret = dquot_commit(dquot);
6978 	if (ret < 0)
6979 		ext4_error_err(dquot->dq_sb, -ret,
6980 			       "Failed to commit dquot type %d",
6981 			       dquot->dq_id.type);
6982 	err = ext4_journal_stop(handle);
6983 	if (!ret)
6984 		ret = err;
6985 	return ret;
6986 }
6987 
6988 static int ext4_acquire_dquot(struct dquot *dquot)
6989 {
6990 	int ret, err;
6991 	handle_t *handle;
6992 
6993 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6994 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6995 	if (IS_ERR(handle))
6996 		return PTR_ERR(handle);
6997 	ret = dquot_acquire(dquot);
6998 	if (ret < 0)
6999 		ext4_error_err(dquot->dq_sb, -ret,
7000 			      "Failed to acquire dquot type %d",
7001 			      dquot->dq_id.type);
7002 	err = ext4_journal_stop(handle);
7003 	if (!ret)
7004 		ret = err;
7005 	return ret;
7006 }
7007 
7008 static int ext4_release_dquot(struct dquot *dquot)
7009 {
7010 	int ret, err;
7011 	handle_t *handle;
7012 	bool freeze_protected = false;
7013 
7014 	/*
7015 	 * Trying to sb_start_intwrite() in a running transaction
7016 	 * can result in a deadlock. Further, running transactions
7017 	 * are already protected from freezing.
7018 	 */
7019 	if (!ext4_journal_current_handle()) {
7020 		sb_start_intwrite(dquot->dq_sb);
7021 		freeze_protected = true;
7022 	}
7023 
7024 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
7025 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
7026 	if (IS_ERR(handle)) {
7027 		/* Release dquot anyway to avoid endless cycle in dqput() */
7028 		dquot_release(dquot);
7029 		if (freeze_protected)
7030 			sb_end_intwrite(dquot->dq_sb);
7031 		return PTR_ERR(handle);
7032 	}
7033 	ret = dquot_release(dquot);
7034 	if (ret < 0)
7035 		ext4_error_err(dquot->dq_sb, -ret,
7036 			       "Failed to release dquot type %d",
7037 			       dquot->dq_id.type);
7038 	err = ext4_journal_stop(handle);
7039 	if (!ret)
7040 		ret = err;
7041 
7042 	if (freeze_protected)
7043 		sb_end_intwrite(dquot->dq_sb);
7044 
7045 	return ret;
7046 }
7047 
7048 static int ext4_mark_dquot_dirty(struct dquot *dquot)
7049 {
7050 	struct super_block *sb = dquot->dq_sb;
7051 
7052 	if (ext4_is_quota_journalled(sb)) {
7053 		dquot_mark_dquot_dirty(dquot);
7054 		return ext4_write_dquot(dquot);
7055 	} else {
7056 		return dquot_mark_dquot_dirty(dquot);
7057 	}
7058 }
7059 
7060 static int ext4_write_info(struct super_block *sb, int type)
7061 {
7062 	int ret, err;
7063 	handle_t *handle;
7064 
7065 	/* Data block + inode block */
7066 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
7067 	if (IS_ERR(handle))
7068 		return PTR_ERR(handle);
7069 	ret = dquot_commit_info(sb, type);
7070 	err = ext4_journal_stop(handle);
7071 	if (!ret)
7072 		ret = err;
7073 	return ret;
7074 }
7075 
7076 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
7077 {
7078 	struct ext4_inode_info *ei = EXT4_I(inode);
7079 
7080 	/* The first argument of lockdep_set_subclass has to be
7081 	 * *exactly* the same as the argument to init_rwsem() --- in
7082 	 * this case, in init_once() --- or lockdep gets unhappy
7083 	 * because the name of the lock is set using the
7084 	 * stringification of the argument to init_rwsem().
7085 	 */
7086 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
7087 	lockdep_set_subclass(&ei->i_data_sem, subclass);
7088 }
7089 
7090 /*
7091  * Standard function to be called on quota_on
7092  */
7093 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
7094 			 const struct path *path)
7095 {
7096 	int err;
7097 
7098 	if (!test_opt(sb, QUOTA))
7099 		return -EINVAL;
7100 
7101 	/* Quotafile not on the same filesystem? */
7102 	if (path->dentry->d_sb != sb)
7103 		return -EXDEV;
7104 
7105 	/* Quota already enabled for this file? */
7106 	if (IS_NOQUOTA(d_inode(path->dentry)))
7107 		return -EBUSY;
7108 
7109 	/* Journaling quota? */
7110 	if (EXT4_SB(sb)->s_qf_names[type]) {
7111 		/* Quotafile not in fs root? */
7112 		if (path->dentry->d_parent != sb->s_root)
7113 			ext4_msg(sb, KERN_WARNING,
7114 				"Quota file not on filesystem root. "
7115 				"Journaled quota will not work");
7116 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
7117 	} else {
7118 		/*
7119 		 * Clear the flag just in case mount options changed since
7120 		 * last time.
7121 		 */
7122 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
7123 	}
7124 
7125 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
7126 	err = dquot_quota_on(sb, type, format_id, path);
7127 	if (!err) {
7128 		struct inode *inode = d_inode(path->dentry);
7129 		handle_t *handle;
7130 
7131 		/*
7132 		 * Set inode flags to prevent userspace from messing with quota
7133 		 * files. If this fails, we return success anyway since quotas
7134 		 * are already enabled and this is not a hard failure.
7135 		 */
7136 		inode_lock(inode);
7137 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7138 		if (IS_ERR(handle))
7139 			goto unlock_inode;
7140 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
7141 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
7142 				S_NOATIME | S_IMMUTABLE);
7143 		err = ext4_mark_inode_dirty(handle, inode);
7144 		ext4_journal_stop(handle);
7145 	unlock_inode:
7146 		inode_unlock(inode);
7147 		if (err)
7148 			dquot_quota_off(sb, type);
7149 	}
7150 	if (err)
7151 		lockdep_set_quota_inode(path->dentry->d_inode,
7152 					     I_DATA_SEM_NORMAL);
7153 	return err;
7154 }
7155 
7156 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
7157 {
7158 	switch (type) {
7159 	case USRQUOTA:
7160 		return qf_inum == EXT4_USR_QUOTA_INO;
7161 	case GRPQUOTA:
7162 		return qf_inum == EXT4_GRP_QUOTA_INO;
7163 	case PRJQUOTA:
7164 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7165 	default:
7166 		BUG();
7167 	}
7168 }
7169 
7170 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7171 			     unsigned int flags)
7172 {
7173 	int err;
7174 	struct inode *qf_inode;
7175 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7176 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7177 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7178 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7179 	};
7180 
7181 	BUG_ON(!ext4_has_feature_quota(sb));
7182 
7183 	if (!qf_inums[type])
7184 		return -EPERM;
7185 
7186 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7187 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7188 				qf_inums[type], type);
7189 		return -EUCLEAN;
7190 	}
7191 
7192 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7193 	if (IS_ERR(qf_inode)) {
7194 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7195 				qf_inums[type], type);
7196 		return PTR_ERR(qf_inode);
7197 	}
7198 
7199 	/* Don't account quota for quota files to avoid recursion */
7200 	qf_inode->i_flags |= S_NOQUOTA;
7201 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7202 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7203 	if (err)
7204 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7205 	iput(qf_inode);
7206 
7207 	return err;
7208 }
7209 
7210 /* Enable usage tracking for all quota types. */
7211 int ext4_enable_quotas(struct super_block *sb)
7212 {
7213 	int type, err = 0;
7214 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7215 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7216 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7217 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7218 	};
7219 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7220 		test_opt(sb, USRQUOTA),
7221 		test_opt(sb, GRPQUOTA),
7222 		test_opt(sb, PRJQUOTA),
7223 	};
7224 
7225 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7226 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7227 		if (qf_inums[type]) {
7228 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7229 				DQUOT_USAGE_ENABLED |
7230 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7231 			if (err) {
7232 				ext4_warning(sb,
7233 					"Failed to enable quota tracking "
7234 					"(type=%d, err=%d, ino=%lu). "
7235 					"Please run e2fsck to fix.", type,
7236 					err, qf_inums[type]);
7237 
7238 				ext4_quotas_off(sb, type);
7239 				return err;
7240 			}
7241 		}
7242 	}
7243 	return 0;
7244 }
7245 
7246 static int ext4_quota_off(struct super_block *sb, int type)
7247 {
7248 	struct inode *inode = sb_dqopt(sb)->files[type];
7249 	handle_t *handle;
7250 	int err;
7251 
7252 	/* Force all delayed allocation blocks to be allocated.
7253 	 * Caller already holds s_umount sem */
7254 	if (test_opt(sb, DELALLOC))
7255 		sync_filesystem(sb);
7256 
7257 	if (!inode || !igrab(inode))
7258 		goto out;
7259 
7260 	err = dquot_quota_off(sb, type);
7261 	if (err || ext4_has_feature_quota(sb))
7262 		goto out_put;
7263 	/*
7264 	 * When the filesystem was remounted read-only first, we cannot cleanup
7265 	 * inode flags here. Bad luck but people should be using QUOTA feature
7266 	 * these days anyway.
7267 	 */
7268 	if (sb_rdonly(sb))
7269 		goto out_put;
7270 
7271 	inode_lock(inode);
7272 	/*
7273 	 * Update modification times of quota files when userspace can
7274 	 * start looking at them. If we fail, we return success anyway since
7275 	 * this is not a hard failure and quotas are already disabled.
7276 	 */
7277 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7278 	if (IS_ERR(handle)) {
7279 		err = PTR_ERR(handle);
7280 		goto out_unlock;
7281 	}
7282 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7283 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7284 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
7285 	err = ext4_mark_inode_dirty(handle, inode);
7286 	ext4_journal_stop(handle);
7287 out_unlock:
7288 	inode_unlock(inode);
7289 out_put:
7290 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7291 	iput(inode);
7292 	return err;
7293 out:
7294 	return dquot_quota_off(sb, type);
7295 }
7296 
7297 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7298  * acquiring the locks... As quota files are never truncated and quota code
7299  * itself serializes the operations (and no one else should touch the files)
7300  * we don't have to be afraid of races */
7301 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7302 			       size_t len, loff_t off)
7303 {
7304 	struct inode *inode = sb_dqopt(sb)->files[type];
7305 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7306 	int offset = off & (sb->s_blocksize - 1);
7307 	int tocopy;
7308 	size_t toread;
7309 	struct buffer_head *bh;
7310 	loff_t i_size = i_size_read(inode);
7311 
7312 	if (off > i_size)
7313 		return 0;
7314 	if (off+len > i_size)
7315 		len = i_size-off;
7316 	toread = len;
7317 	while (toread > 0) {
7318 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7319 		bh = ext4_bread(NULL, inode, blk, 0);
7320 		if (IS_ERR(bh))
7321 			return PTR_ERR(bh);
7322 		if (!bh)	/* A hole? */
7323 			memset(data, 0, tocopy);
7324 		else
7325 			memcpy(data, bh->b_data+offset, tocopy);
7326 		brelse(bh);
7327 		offset = 0;
7328 		toread -= tocopy;
7329 		data += tocopy;
7330 		blk++;
7331 	}
7332 	return len;
7333 }
7334 
7335 /* Write to quotafile (we know the transaction is already started and has
7336  * enough credits) */
7337 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7338 				const char *data, size_t len, loff_t off)
7339 {
7340 	struct inode *inode = sb_dqopt(sb)->files[type];
7341 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7342 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7343 	int retries = 0;
7344 	struct buffer_head *bh;
7345 	handle_t *handle = journal_current_handle();
7346 
7347 	if (!handle) {
7348 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7349 			" cancelled because transaction is not started",
7350 			(unsigned long long)off, (unsigned long long)len);
7351 		return -EIO;
7352 	}
7353 	/*
7354 	 * Since we account only one data block in transaction credits,
7355 	 * then it is impossible to cross a block boundary.
7356 	 */
7357 	if (sb->s_blocksize - offset < len) {
7358 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7359 			" cancelled because not block aligned",
7360 			(unsigned long long)off, (unsigned long long)len);
7361 		return -EIO;
7362 	}
7363 
7364 	do {
7365 		bh = ext4_bread(handle, inode, blk,
7366 				EXT4_GET_BLOCKS_CREATE |
7367 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7368 	} while (PTR_ERR(bh) == -ENOSPC &&
7369 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7370 	if (IS_ERR(bh))
7371 		return PTR_ERR(bh);
7372 	if (!bh)
7373 		goto out;
7374 	BUFFER_TRACE(bh, "get write access");
7375 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7376 	if (err) {
7377 		brelse(bh);
7378 		return err;
7379 	}
7380 	lock_buffer(bh);
7381 	memcpy(bh->b_data+offset, data, len);
7382 	flush_dcache_folio(bh->b_folio);
7383 	unlock_buffer(bh);
7384 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7385 	brelse(bh);
7386 out:
7387 	if (inode->i_size < off + len) {
7388 		i_size_write(inode, off + len);
7389 		EXT4_I(inode)->i_disksize = inode->i_size;
7390 		err2 = ext4_mark_inode_dirty(handle, inode);
7391 		if (unlikely(err2 && !err))
7392 			err = err2;
7393 	}
7394 	return err ? err : len;
7395 }
7396 #endif
7397 
7398 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7399 static inline void register_as_ext2(void)
7400 {
7401 	int err = register_filesystem(&ext2_fs_type);
7402 	if (err)
7403 		printk(KERN_WARNING
7404 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7405 }
7406 
7407 static inline void unregister_as_ext2(void)
7408 {
7409 	unregister_filesystem(&ext2_fs_type);
7410 }
7411 
7412 static inline int ext2_feature_set_ok(struct super_block *sb)
7413 {
7414 	if (ext4_has_unknown_ext2_incompat_features(sb))
7415 		return 0;
7416 	if (sb_rdonly(sb))
7417 		return 1;
7418 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7419 		return 0;
7420 	return 1;
7421 }
7422 #else
7423 static inline void register_as_ext2(void) { }
7424 static inline void unregister_as_ext2(void) { }
7425 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7426 #endif
7427 
7428 static inline void register_as_ext3(void)
7429 {
7430 	int err = register_filesystem(&ext3_fs_type);
7431 	if (err)
7432 		printk(KERN_WARNING
7433 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7434 }
7435 
7436 static inline void unregister_as_ext3(void)
7437 {
7438 	unregister_filesystem(&ext3_fs_type);
7439 }
7440 
7441 static inline int ext3_feature_set_ok(struct super_block *sb)
7442 {
7443 	if (ext4_has_unknown_ext3_incompat_features(sb))
7444 		return 0;
7445 	if (!ext4_has_feature_journal(sb))
7446 		return 0;
7447 	if (sb_rdonly(sb))
7448 		return 1;
7449 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7450 		return 0;
7451 	return 1;
7452 }
7453 
7454 static void ext4_kill_sb(struct super_block *sb)
7455 {
7456 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7457 	struct file *bdev_file = sbi ? sbi->s_journal_bdev_file : NULL;
7458 
7459 	kill_block_super(sb);
7460 
7461 	if (bdev_file)
7462 		bdev_fput(bdev_file);
7463 }
7464 
7465 static struct file_system_type ext4_fs_type = {
7466 	.owner			= THIS_MODULE,
7467 	.name			= "ext4",
7468 	.init_fs_context	= ext4_init_fs_context,
7469 	.parameters		= ext4_param_specs,
7470 	.kill_sb		= ext4_kill_sb,
7471 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME |
7472 				  FS_LBS,
7473 };
7474 MODULE_ALIAS_FS("ext4");
7475 
7476 static int __init ext4_init_fs(void)
7477 {
7478 	int err;
7479 
7480 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7481 	ext4_li_info = NULL;
7482 
7483 	/* Build-time check for flags consistency */
7484 	ext4_check_flag_values();
7485 
7486 	err = ext4_init_es();
7487 	if (err)
7488 		return err;
7489 
7490 	err = ext4_init_pending();
7491 	if (err)
7492 		goto out7;
7493 
7494 	err = ext4_init_post_read_processing();
7495 	if (err)
7496 		goto out6;
7497 
7498 	err = ext4_init_pageio();
7499 	if (err)
7500 		goto out5;
7501 
7502 	err = ext4_init_system_zone();
7503 	if (err)
7504 		goto out4;
7505 
7506 	err = ext4_init_sysfs();
7507 	if (err)
7508 		goto out3;
7509 
7510 	err = ext4_init_mballoc();
7511 	if (err)
7512 		goto out2;
7513 	err = init_inodecache();
7514 	if (err)
7515 		goto out1;
7516 
7517 	err = ext4_fc_init_dentry_cache();
7518 	if (err)
7519 		goto out05;
7520 
7521 	register_as_ext3();
7522 	register_as_ext2();
7523 	err = register_filesystem(&ext4_fs_type);
7524 	if (err)
7525 		goto out;
7526 
7527 	return 0;
7528 out:
7529 	unregister_as_ext2();
7530 	unregister_as_ext3();
7531 	ext4_fc_destroy_dentry_cache();
7532 out05:
7533 	destroy_inodecache();
7534 out1:
7535 	ext4_exit_mballoc();
7536 out2:
7537 	ext4_exit_sysfs();
7538 out3:
7539 	ext4_exit_system_zone();
7540 out4:
7541 	ext4_exit_pageio();
7542 out5:
7543 	ext4_exit_post_read_processing();
7544 out6:
7545 	ext4_exit_pending();
7546 out7:
7547 	ext4_exit_es();
7548 
7549 	return err;
7550 }
7551 
7552 static void __exit ext4_exit_fs(void)
7553 {
7554 	ext4_destroy_lazyinit_thread();
7555 	unregister_as_ext2();
7556 	unregister_as_ext3();
7557 	unregister_filesystem(&ext4_fs_type);
7558 	ext4_fc_destroy_dentry_cache();
7559 	destroy_inodecache();
7560 	ext4_exit_mballoc();
7561 	ext4_exit_sysfs();
7562 	ext4_exit_system_zone();
7563 	ext4_exit_pageio();
7564 	ext4_exit_post_read_processing();
7565 	ext4_exit_es();
7566 	ext4_exit_pending();
7567 }
7568 
7569 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7570 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7571 MODULE_LICENSE("GPL");
7572 module_init(ext4_init_fs)
7573 module_exit(ext4_exit_fs)
7574