xref: /linux/fs/ext4/super.c (revision fbeea4db51a6eaf62b4784f718844726dd2199b9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_unregister_li_request(struct super_block *sb);
83 static void ext4_clear_request_list(void);
84 static struct inode *ext4_get_journal_inode(struct super_block *sb,
85 					    unsigned int journal_inum);
86 static int ext4_validate_options(struct fs_context *fc);
87 static int ext4_check_opt_consistency(struct fs_context *fc,
88 				      struct super_block *sb);
89 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
90 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
91 static int ext4_get_tree(struct fs_context *fc);
92 static int ext4_reconfigure(struct fs_context *fc);
93 static void ext4_fc_free(struct fs_context *fc);
94 static int ext4_init_fs_context(struct fs_context *fc);
95 static void ext4_kill_sb(struct super_block *sb);
96 static const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= ext4_kill_sb,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_type == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= ext4_kill_sb,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_type == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
163 				  bh_end_io_t *end_io, bool simu_fail)
164 {
165 	if (simu_fail) {
166 		clear_buffer_uptodate(bh);
167 		unlock_buffer(bh);
168 		return;
169 	}
170 
171 	/*
172 	 * buffer's verified bit is no longer valid after reading from
173 	 * disk again due to write out error, clear it to make sure we
174 	 * recheck the buffer contents.
175 	 */
176 	clear_buffer_verified(bh);
177 
178 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
179 	get_bh(bh);
180 	submit_bh(REQ_OP_READ | op_flags, bh);
181 }
182 
183 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
184 			 bh_end_io_t *end_io, bool simu_fail)
185 {
186 	BUG_ON(!buffer_locked(bh));
187 
188 	if (ext4_buffer_uptodate(bh)) {
189 		unlock_buffer(bh);
190 		return;
191 	}
192 	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
193 }
194 
195 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
196 		 bh_end_io_t *end_io, bool simu_fail)
197 {
198 	BUG_ON(!buffer_locked(bh));
199 
200 	if (ext4_buffer_uptodate(bh)) {
201 		unlock_buffer(bh);
202 		return 0;
203 	}
204 
205 	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
206 
207 	wait_on_buffer(bh);
208 	if (buffer_uptodate(bh))
209 		return 0;
210 	return -EIO;
211 }
212 
213 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
214 {
215 	lock_buffer(bh);
216 	if (!wait) {
217 		ext4_read_bh_nowait(bh, op_flags, NULL, false);
218 		return 0;
219 	}
220 	return ext4_read_bh(bh, op_flags, NULL, false);
221 }
222 
223 /*
224  * This works like __bread_gfp() except it uses ERR_PTR for error
225  * returns.  Currently with sb_bread it's impossible to distinguish
226  * between ENOMEM and EIO situations (since both result in a NULL
227  * return.
228  */
229 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
230 					       sector_t block,
231 					       blk_opf_t op_flags, gfp_t gfp)
232 {
233 	struct buffer_head *bh;
234 	int ret;
235 
236 	bh = sb_getblk_gfp(sb, block, gfp);
237 	if (bh == NULL)
238 		return ERR_PTR(-ENOMEM);
239 	if (ext4_buffer_uptodate(bh))
240 		return bh;
241 
242 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
243 	if (ret) {
244 		put_bh(bh);
245 		return ERR_PTR(ret);
246 	}
247 	return bh;
248 }
249 
250 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
251 				   blk_opf_t op_flags)
252 {
253 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
254 			~__GFP_FS) | __GFP_MOVABLE;
255 
256 	return __ext4_sb_bread_gfp(sb, block, op_flags, gfp);
257 }
258 
259 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
260 					    sector_t block)
261 {
262 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
263 			~__GFP_FS);
264 
265 	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
266 }
267 
268 struct buffer_head *ext4_sb_bread_nofail(struct super_block *sb,
269 					 sector_t block)
270 {
271 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
272 			~__GFP_FS) | __GFP_MOVABLE | __GFP_NOFAIL;
273 
274 	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
275 }
276 
277 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
278 {
279 	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
280 			sb->s_blocksize, GFP_NOWAIT);
281 
282 	if (likely(bh)) {
283 		if (trylock_buffer(bh))
284 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL, false);
285 		brelse(bh);
286 	}
287 }
288 
289 static int ext4_verify_csum_type(struct super_block *sb,
290 				 struct ext4_super_block *es)
291 {
292 	if (!ext4_has_feature_metadata_csum(sb))
293 		return 1;
294 
295 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
296 }
297 
298 __le32 ext4_superblock_csum(struct ext4_super_block *es)
299 {
300 	int offset = offsetof(struct ext4_super_block, s_checksum);
301 	__u32 csum;
302 
303 	csum = ext4_chksum(~0, (char *)es, offset);
304 
305 	return cpu_to_le32(csum);
306 }
307 
308 static int ext4_superblock_csum_verify(struct super_block *sb,
309 				       struct ext4_super_block *es)
310 {
311 	if (!ext4_has_feature_metadata_csum(sb))
312 		return 1;
313 
314 	return es->s_checksum == ext4_superblock_csum(es);
315 }
316 
317 void ext4_superblock_csum_set(struct super_block *sb)
318 {
319 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
320 
321 	if (!ext4_has_feature_metadata_csum(sb))
322 		return;
323 
324 	es->s_checksum = ext4_superblock_csum(es);
325 }
326 
327 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
328 			       struct ext4_group_desc *bg)
329 {
330 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
331 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
332 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
333 }
334 
335 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
336 			       struct ext4_group_desc *bg)
337 {
338 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
339 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
340 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
341 }
342 
343 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
344 			      struct ext4_group_desc *bg)
345 {
346 	return le32_to_cpu(bg->bg_inode_table_lo) |
347 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
348 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
349 }
350 
351 __u32 ext4_free_group_clusters(struct super_block *sb,
352 			       struct ext4_group_desc *bg)
353 {
354 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
355 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
356 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
357 }
358 
359 __u32 ext4_free_inodes_count(struct super_block *sb,
360 			      struct ext4_group_desc *bg)
361 {
362 	return le16_to_cpu(READ_ONCE(bg->bg_free_inodes_count_lo)) |
363 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
364 		 (__u32)le16_to_cpu(READ_ONCE(bg->bg_free_inodes_count_hi)) << 16 : 0);
365 }
366 
367 __u32 ext4_used_dirs_count(struct super_block *sb,
368 			      struct ext4_group_desc *bg)
369 {
370 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
371 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
372 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
373 }
374 
375 __u32 ext4_itable_unused_count(struct super_block *sb,
376 			      struct ext4_group_desc *bg)
377 {
378 	return le16_to_cpu(bg->bg_itable_unused_lo) |
379 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
380 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
381 }
382 
383 void ext4_block_bitmap_set(struct super_block *sb,
384 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
385 {
386 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
387 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
388 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
389 }
390 
391 void ext4_inode_bitmap_set(struct super_block *sb,
392 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
393 {
394 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
395 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
396 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
397 }
398 
399 void ext4_inode_table_set(struct super_block *sb,
400 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
401 {
402 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
403 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
404 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
405 }
406 
407 void ext4_free_group_clusters_set(struct super_block *sb,
408 				  struct ext4_group_desc *bg, __u32 count)
409 {
410 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
411 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
412 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
413 }
414 
415 void ext4_free_inodes_set(struct super_block *sb,
416 			  struct ext4_group_desc *bg, __u32 count)
417 {
418 	WRITE_ONCE(bg->bg_free_inodes_count_lo, cpu_to_le16((__u16)count));
419 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
420 		WRITE_ONCE(bg->bg_free_inodes_count_hi, cpu_to_le16(count >> 16));
421 }
422 
423 void ext4_used_dirs_set(struct super_block *sb,
424 			  struct ext4_group_desc *bg, __u32 count)
425 {
426 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
427 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
428 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
429 }
430 
431 void ext4_itable_unused_set(struct super_block *sb,
432 			  struct ext4_group_desc *bg, __u32 count)
433 {
434 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
435 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
436 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
437 }
438 
439 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
440 {
441 	now = clamp_val(now, 0, (1ull << 40) - 1);
442 
443 	*lo = cpu_to_le32(lower_32_bits(now));
444 	*hi = upper_32_bits(now);
445 }
446 
447 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
448 {
449 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
450 }
451 #define ext4_update_tstamp(es, tstamp) \
452 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
453 			     ktime_get_real_seconds())
454 #define ext4_get_tstamp(es, tstamp) \
455 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
456 
457 /*
458  * The ext4_maybe_update_superblock() function checks and updates the
459  * superblock if needed.
460  *
461  * This function is designed to update the on-disk superblock only under
462  * certain conditions to prevent excessive disk writes and unnecessary
463  * waking of the disk from sleep. The superblock will be updated if:
464  * 1. More than sbi->s_sb_update_sec (def: 1 hour) has passed since the last
465  *    superblock update
466  * 2. More than sbi->s_sb_update_kb (def: 16MB) kbs have been written since the
467  *    last superblock update.
468  *
469  * @sb: The superblock
470  */
471 static void ext4_maybe_update_superblock(struct super_block *sb)
472 {
473 	struct ext4_sb_info *sbi = EXT4_SB(sb);
474 	struct ext4_super_block *es = sbi->s_es;
475 	journal_t *journal = sbi->s_journal;
476 	time64_t now;
477 	__u64 last_update;
478 	__u64 lifetime_write_kbytes;
479 	__u64 diff_size;
480 
481 	if (ext4_emergency_state(sb) || sb_rdonly(sb) ||
482 	    !(sb->s_flags & SB_ACTIVE) || !journal ||
483 	    journal->j_flags & JBD2_UNMOUNT)
484 		return;
485 
486 	now = ktime_get_real_seconds();
487 	last_update = ext4_get_tstamp(es, s_wtime);
488 
489 	if (likely(now - last_update < sbi->s_sb_update_sec))
490 		return;
491 
492 	lifetime_write_kbytes = sbi->s_kbytes_written +
493 		((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
494 		  sbi->s_sectors_written_start) >> 1);
495 
496 	/* Get the number of kilobytes not written to disk to account
497 	 * for statistics and compare with a multiple of 16 MB. This
498 	 * is used to determine when the next superblock commit should
499 	 * occur (i.e. not more often than once per 16MB if there was
500 	 * less written in an hour).
501 	 */
502 	diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written);
503 
504 	if (diff_size > sbi->s_sb_update_kb)
505 		schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
506 }
507 
508 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
509 {
510 	struct super_block		*sb = journal->j_private;
511 
512 	BUG_ON(txn->t_state == T_FINISHED);
513 
514 	ext4_process_freed_data(sb, txn->t_tid);
515 	ext4_maybe_update_superblock(sb);
516 }
517 
518 static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode,
519 		struct folio *folio)
520 {
521 	struct buffer_head *bh, *head;
522 	struct journal_head *jh;
523 
524 	bh = head = folio_buffers(folio);
525 	do {
526 		/*
527 		 * We have to redirty a page in these cases:
528 		 * 1) If buffer is dirty, it means the page was dirty because it
529 		 * contains a buffer that needs checkpointing. So the dirty bit
530 		 * needs to be preserved so that checkpointing writes the buffer
531 		 * properly.
532 		 * 2) If buffer is not part of the committing transaction
533 		 * (we may have just accidentally come across this buffer because
534 		 * inode range tracking is not exact) or if the currently running
535 		 * transaction already contains this buffer as well, dirty bit
536 		 * needs to be preserved so that the buffer gets writeprotected
537 		 * properly on running transaction's commit.
538 		 */
539 		jh = bh2jh(bh);
540 		if (buffer_dirty(bh) ||
541 		    (jh && (jh->b_transaction != jinode->i_transaction ||
542 			    jh->b_next_transaction)))
543 			return true;
544 	} while ((bh = bh->b_this_page) != head);
545 
546 	return false;
547 }
548 
549 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
550 {
551 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
552 	struct writeback_control wbc = {
553 		.sync_mode =  WB_SYNC_ALL,
554 		.nr_to_write = LONG_MAX,
555 		.range_start = jinode->i_dirty_start,
556 		.range_end = jinode->i_dirty_end,
557         };
558 	struct folio *folio = NULL;
559 	int error;
560 
561 	/*
562 	 * writeback_iter() already checks for dirty pages and calls
563 	 * folio_clear_dirty_for_io(), which we want to write protect the
564 	 * folios.
565 	 *
566 	 * However, we may have to redirty a folio sometimes.
567 	 */
568 	while ((folio = writeback_iter(mapping, &wbc, folio, &error))) {
569 		if (ext4_journalled_writepage_needs_redirty(jinode, folio))
570 			folio_redirty_for_writepage(&wbc, folio);
571 		folio_unlock(folio);
572 	}
573 
574 	return error;
575 }
576 
577 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
578 {
579 	int ret;
580 
581 	if (ext4_should_journal_data(jinode->i_vfs_inode))
582 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
583 	else
584 		ret = ext4_normal_submit_inode_data_buffers(jinode);
585 	return ret;
586 }
587 
588 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
589 {
590 	int ret = 0;
591 
592 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
593 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
594 
595 	return ret;
596 }
597 
598 static bool system_going_down(void)
599 {
600 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
601 		|| system_state == SYSTEM_RESTART;
602 }
603 
604 struct ext4_err_translation {
605 	int code;
606 	int errno;
607 };
608 
609 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
610 
611 static struct ext4_err_translation err_translation[] = {
612 	EXT4_ERR_TRANSLATE(EIO),
613 	EXT4_ERR_TRANSLATE(ENOMEM),
614 	EXT4_ERR_TRANSLATE(EFSBADCRC),
615 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
616 	EXT4_ERR_TRANSLATE(ENOSPC),
617 	EXT4_ERR_TRANSLATE(ENOKEY),
618 	EXT4_ERR_TRANSLATE(EROFS),
619 	EXT4_ERR_TRANSLATE(EFBIG),
620 	EXT4_ERR_TRANSLATE(EEXIST),
621 	EXT4_ERR_TRANSLATE(ERANGE),
622 	EXT4_ERR_TRANSLATE(EOVERFLOW),
623 	EXT4_ERR_TRANSLATE(EBUSY),
624 	EXT4_ERR_TRANSLATE(ENOTDIR),
625 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
626 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
627 	EXT4_ERR_TRANSLATE(EFAULT),
628 };
629 
630 static int ext4_errno_to_code(int errno)
631 {
632 	int i;
633 
634 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
635 		if (err_translation[i].errno == errno)
636 			return err_translation[i].code;
637 	return EXT4_ERR_UNKNOWN;
638 }
639 
640 static void save_error_info(struct super_block *sb, int error,
641 			    __u32 ino, __u64 block,
642 			    const char *func, unsigned int line)
643 {
644 	struct ext4_sb_info *sbi = EXT4_SB(sb);
645 
646 	/* We default to EFSCORRUPTED error... */
647 	if (error == 0)
648 		error = EFSCORRUPTED;
649 
650 	spin_lock(&sbi->s_error_lock);
651 	sbi->s_add_error_count++;
652 	sbi->s_last_error_code = error;
653 	sbi->s_last_error_line = line;
654 	sbi->s_last_error_ino = ino;
655 	sbi->s_last_error_block = block;
656 	sbi->s_last_error_func = func;
657 	sbi->s_last_error_time = ktime_get_real_seconds();
658 	if (!sbi->s_first_error_time) {
659 		sbi->s_first_error_code = error;
660 		sbi->s_first_error_line = line;
661 		sbi->s_first_error_ino = ino;
662 		sbi->s_first_error_block = block;
663 		sbi->s_first_error_func = func;
664 		sbi->s_first_error_time = sbi->s_last_error_time;
665 	}
666 	spin_unlock(&sbi->s_error_lock);
667 }
668 
669 /* Deal with the reporting of failure conditions on a filesystem such as
670  * inconsistencies detected or read IO failures.
671  *
672  * On ext2, we can store the error state of the filesystem in the
673  * superblock.  That is not possible on ext4, because we may have other
674  * write ordering constraints on the superblock which prevent us from
675  * writing it out straight away; and given that the journal is about to
676  * be aborted, we can't rely on the current, or future, transactions to
677  * write out the superblock safely.
678  *
679  * We'll just use the jbd2_journal_abort() error code to record an error in
680  * the journal instead.  On recovery, the journal will complain about
681  * that error until we've noted it down and cleared it.
682  *
683  * If force_ro is set, we unconditionally force the filesystem into an
684  * ABORT|READONLY state, unless the error response on the fs has been set to
685  * panic in which case we take the easy way out and panic immediately. This is
686  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
687  * at a critical moment in log management.
688  */
689 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
690 			      __u32 ino, __u64 block,
691 			      const char *func, unsigned int line)
692 {
693 	journal_t *journal = EXT4_SB(sb)->s_journal;
694 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
695 
696 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
697 	if (test_opt(sb, WARN_ON_ERROR))
698 		WARN_ON_ONCE(1);
699 
700 	if (!continue_fs && !ext4_emergency_ro(sb) && journal)
701 		jbd2_journal_abort(journal, -error);
702 
703 	if (!bdev_read_only(sb->s_bdev)) {
704 		save_error_info(sb, error, ino, block, func, line);
705 		/*
706 		 * In case the fs should keep running, we need to writeout
707 		 * superblock through the journal. Due to lock ordering
708 		 * constraints, it may not be safe to do it right here so we
709 		 * defer superblock flushing to a workqueue. We just need to be
710 		 * careful when the journal is already shutting down. If we get
711 		 * here in that case, just update the sb directly as the last
712 		 * transaction won't commit anyway.
713 		 */
714 		if (continue_fs && journal &&
715 		    !ext4_test_mount_flag(sb, EXT4_MF_JOURNAL_DESTROY))
716 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
717 		else
718 			ext4_commit_super(sb);
719 	}
720 
721 	/*
722 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
723 	 * could panic during 'reboot -f' as the underlying device got already
724 	 * disabled.
725 	 */
726 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
727 		panic("EXT4-fs (device %s): panic forced after error\n",
728 			sb->s_id);
729 	}
730 
731 	if (ext4_emergency_ro(sb) || continue_fs)
732 		return;
733 
734 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
735 	/*
736 	 * We don't set SB_RDONLY because that requires sb->s_umount
737 	 * semaphore and setting it without proper remount procedure is
738 	 * confusing code such as freeze_super() leading to deadlocks
739 	 * and other problems.
740 	 */
741 	set_bit(EXT4_FLAGS_EMERGENCY_RO, &EXT4_SB(sb)->s_ext4_flags);
742 }
743 
744 static void update_super_work(struct work_struct *work)
745 {
746 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
747 						s_sb_upd_work);
748 	journal_t *journal = sbi->s_journal;
749 	handle_t *handle;
750 
751 	/*
752 	 * If the journal is still running, we have to write out superblock
753 	 * through the journal to avoid collisions of other journalled sb
754 	 * updates.
755 	 *
756 	 * We use directly jbd2 functions here to avoid recursing back into
757 	 * ext4 error handling code during handling of previous errors.
758 	 */
759 	if (!ext4_emergency_state(sbi->s_sb) &&
760 	    !sb_rdonly(sbi->s_sb) && journal) {
761 		struct buffer_head *sbh = sbi->s_sbh;
762 		bool call_notify_err = false;
763 
764 		handle = jbd2_journal_start(journal, 1);
765 		if (IS_ERR(handle))
766 			goto write_directly;
767 		if (jbd2_journal_get_write_access(handle, sbh)) {
768 			jbd2_journal_stop(handle);
769 			goto write_directly;
770 		}
771 
772 		if (sbi->s_add_error_count > 0)
773 			call_notify_err = true;
774 
775 		ext4_update_super(sbi->s_sb);
776 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
777 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
778 				 "superblock detected");
779 			clear_buffer_write_io_error(sbh);
780 			set_buffer_uptodate(sbh);
781 		}
782 
783 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
784 			jbd2_journal_stop(handle);
785 			goto write_directly;
786 		}
787 		jbd2_journal_stop(handle);
788 
789 		if (call_notify_err)
790 			ext4_notify_error_sysfs(sbi);
791 
792 		return;
793 	}
794 write_directly:
795 	/*
796 	 * Write through journal failed. Write sb directly to get error info
797 	 * out and hope for the best.
798 	 */
799 	ext4_commit_super(sbi->s_sb);
800 	ext4_notify_error_sysfs(sbi);
801 }
802 
803 #define ext4_error_ratelimit(sb)					\
804 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
805 			     "EXT4-fs error")
806 
807 void __ext4_error(struct super_block *sb, const char *function,
808 		  unsigned int line, bool force_ro, int error, __u64 block,
809 		  const char *fmt, ...)
810 {
811 	struct va_format vaf;
812 	va_list args;
813 
814 	if (unlikely(ext4_emergency_state(sb)))
815 		return;
816 
817 	trace_ext4_error(sb, function, line);
818 	if (ext4_error_ratelimit(sb)) {
819 		va_start(args, fmt);
820 		vaf.fmt = fmt;
821 		vaf.va = &args;
822 		printk(KERN_CRIT
823 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
824 		       sb->s_id, function, line, current->comm, &vaf);
825 		va_end(args);
826 	}
827 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
828 
829 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
830 }
831 
832 void __ext4_error_inode(struct inode *inode, const char *function,
833 			unsigned int line, ext4_fsblk_t block, int error,
834 			const char *fmt, ...)
835 {
836 	va_list args;
837 	struct va_format vaf;
838 
839 	if (unlikely(ext4_emergency_state(inode->i_sb)))
840 		return;
841 
842 	trace_ext4_error(inode->i_sb, function, line);
843 	if (ext4_error_ratelimit(inode->i_sb)) {
844 		va_start(args, fmt);
845 		vaf.fmt = fmt;
846 		vaf.va = &args;
847 		if (block)
848 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
849 			       "inode #%lu: block %llu: comm %s: %pV\n",
850 			       inode->i_sb->s_id, function, line, inode->i_ino,
851 			       block, current->comm, &vaf);
852 		else
853 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
854 			       "inode #%lu: comm %s: %pV\n",
855 			       inode->i_sb->s_id, function, line, inode->i_ino,
856 			       current->comm, &vaf);
857 		va_end(args);
858 	}
859 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
860 
861 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
862 			  function, line);
863 }
864 
865 void __ext4_error_file(struct file *file, const char *function,
866 		       unsigned int line, ext4_fsblk_t block,
867 		       const char *fmt, ...)
868 {
869 	va_list args;
870 	struct va_format vaf;
871 	struct inode *inode = file_inode(file);
872 	char pathname[80], *path;
873 
874 	if (unlikely(ext4_emergency_state(inode->i_sb)))
875 		return;
876 
877 	trace_ext4_error(inode->i_sb, function, line);
878 	if (ext4_error_ratelimit(inode->i_sb)) {
879 		path = file_path(file, pathname, sizeof(pathname));
880 		if (IS_ERR(path))
881 			path = "(unknown)";
882 		va_start(args, fmt);
883 		vaf.fmt = fmt;
884 		vaf.va = &args;
885 		if (block)
886 			printk(KERN_CRIT
887 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
888 			       "block %llu: comm %s: path %s: %pV\n",
889 			       inode->i_sb->s_id, function, line, inode->i_ino,
890 			       block, current->comm, path, &vaf);
891 		else
892 			printk(KERN_CRIT
893 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
894 			       "comm %s: path %s: %pV\n",
895 			       inode->i_sb->s_id, function, line, inode->i_ino,
896 			       current->comm, path, &vaf);
897 		va_end(args);
898 	}
899 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
900 
901 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
902 			  function, line);
903 }
904 
905 const char *ext4_decode_error(struct super_block *sb, int errno,
906 			      char nbuf[16])
907 {
908 	char *errstr = NULL;
909 
910 	switch (errno) {
911 	case -EFSCORRUPTED:
912 		errstr = "Corrupt filesystem";
913 		break;
914 	case -EFSBADCRC:
915 		errstr = "Filesystem failed CRC";
916 		break;
917 	case -EIO:
918 		errstr = "IO failure";
919 		break;
920 	case -ENOMEM:
921 		errstr = "Out of memory";
922 		break;
923 	case -EROFS:
924 		if (!sb || (EXT4_SB(sb)->s_journal &&
925 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
926 			errstr = "Journal has aborted";
927 		else
928 			errstr = "Readonly filesystem";
929 		break;
930 	default:
931 		/* If the caller passed in an extra buffer for unknown
932 		 * errors, textualise them now.  Else we just return
933 		 * NULL. */
934 		if (nbuf) {
935 			/* Check for truncated error codes... */
936 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
937 				errstr = nbuf;
938 		}
939 		break;
940 	}
941 
942 	return errstr;
943 }
944 
945 /* __ext4_std_error decodes expected errors from journaling functions
946  * automatically and invokes the appropriate error response.  */
947 
948 void __ext4_std_error(struct super_block *sb, const char *function,
949 		      unsigned int line, int errno)
950 {
951 	char nbuf[16];
952 	const char *errstr;
953 
954 	if (unlikely(ext4_emergency_state(sb)))
955 		return;
956 
957 	/* Special case: if the error is EROFS, and we're not already
958 	 * inside a transaction, then there's really no point in logging
959 	 * an error. */
960 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
961 		return;
962 
963 	if (ext4_error_ratelimit(sb)) {
964 		errstr = ext4_decode_error(sb, errno, nbuf);
965 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
966 		       sb->s_id, function, line, errstr);
967 	}
968 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
969 
970 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
971 }
972 
973 void __ext4_msg(struct super_block *sb,
974 		const char *prefix, const char *fmt, ...)
975 {
976 	struct va_format vaf;
977 	va_list args;
978 
979 	if (sb) {
980 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
981 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
982 				  "EXT4-fs"))
983 			return;
984 	}
985 
986 	va_start(args, fmt);
987 	vaf.fmt = fmt;
988 	vaf.va = &args;
989 	if (sb)
990 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
991 	else
992 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
993 	va_end(args);
994 }
995 
996 static int ext4_warning_ratelimit(struct super_block *sb)
997 {
998 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
999 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1000 			    "EXT4-fs warning");
1001 }
1002 
1003 void __ext4_warning(struct super_block *sb, const char *function,
1004 		    unsigned int line, const char *fmt, ...)
1005 {
1006 	struct va_format vaf;
1007 	va_list args;
1008 
1009 	if (!ext4_warning_ratelimit(sb))
1010 		return;
1011 
1012 	va_start(args, fmt);
1013 	vaf.fmt = fmt;
1014 	vaf.va = &args;
1015 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1016 	       sb->s_id, function, line, &vaf);
1017 	va_end(args);
1018 }
1019 
1020 void __ext4_warning_inode(const struct inode *inode, const char *function,
1021 			  unsigned int line, const char *fmt, ...)
1022 {
1023 	struct va_format vaf;
1024 	va_list args;
1025 
1026 	if (!ext4_warning_ratelimit(inode->i_sb))
1027 		return;
1028 
1029 	va_start(args, fmt);
1030 	vaf.fmt = fmt;
1031 	vaf.va = &args;
1032 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1033 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
1034 	       function, line, inode->i_ino, current->comm, &vaf);
1035 	va_end(args);
1036 }
1037 
1038 void __ext4_grp_locked_error(const char *function, unsigned int line,
1039 			     struct super_block *sb, ext4_group_t grp,
1040 			     unsigned long ino, ext4_fsblk_t block,
1041 			     const char *fmt, ...)
1042 __releases(bitlock)
1043 __acquires(bitlock)
1044 {
1045 	struct va_format vaf;
1046 	va_list args;
1047 
1048 	if (unlikely(ext4_emergency_state(sb)))
1049 		return;
1050 
1051 	trace_ext4_error(sb, function, line);
1052 	if (ext4_error_ratelimit(sb)) {
1053 		va_start(args, fmt);
1054 		vaf.fmt = fmt;
1055 		vaf.va = &args;
1056 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1057 		       sb->s_id, function, line, grp);
1058 		if (ino)
1059 			printk(KERN_CONT "inode %lu: ", ino);
1060 		if (block)
1061 			printk(KERN_CONT "block %llu:",
1062 			       (unsigned long long) block);
1063 		printk(KERN_CONT "%pV\n", &vaf);
1064 		va_end(args);
1065 	}
1066 
1067 	if (test_opt(sb, ERRORS_CONT)) {
1068 		if (test_opt(sb, WARN_ON_ERROR))
1069 			WARN_ON_ONCE(1);
1070 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1071 		if (!bdev_read_only(sb->s_bdev)) {
1072 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1073 					line);
1074 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1075 		}
1076 		return;
1077 	}
1078 	ext4_unlock_group(sb, grp);
1079 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1080 	/*
1081 	 * We only get here in the ERRORS_RO case; relocking the group
1082 	 * may be dangerous, but nothing bad will happen since the
1083 	 * filesystem will have already been marked read/only and the
1084 	 * journal has been aborted.  We return 1 as a hint to callers
1085 	 * who might what to use the return value from
1086 	 * ext4_grp_locked_error() to distinguish between the
1087 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1088 	 * aggressively from the ext4 function in question, with a
1089 	 * more appropriate error code.
1090 	 */
1091 	ext4_lock_group(sb, grp);
1092 	return;
1093 }
1094 
1095 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1096 				     ext4_group_t group,
1097 				     unsigned int flags)
1098 {
1099 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1100 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1101 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1102 	int ret;
1103 
1104 	if (!grp || !gdp)
1105 		return;
1106 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1107 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1108 					    &grp->bb_state);
1109 		if (!ret)
1110 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1111 					   grp->bb_free);
1112 	}
1113 
1114 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1115 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1116 					    &grp->bb_state);
1117 		if (!ret && gdp) {
1118 			int count;
1119 
1120 			count = ext4_free_inodes_count(sb, gdp);
1121 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1122 					   count);
1123 		}
1124 	}
1125 }
1126 
1127 void ext4_update_dynamic_rev(struct super_block *sb)
1128 {
1129 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1130 
1131 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1132 		return;
1133 
1134 	ext4_warning(sb,
1135 		     "updating to rev %d because of new feature flag, "
1136 		     "running e2fsck is recommended",
1137 		     EXT4_DYNAMIC_REV);
1138 
1139 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1140 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1141 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1142 	/* leave es->s_feature_*compat flags alone */
1143 	/* es->s_uuid will be set by e2fsck if empty */
1144 
1145 	/*
1146 	 * The rest of the superblock fields should be zero, and if not it
1147 	 * means they are likely already in use, so leave them alone.  We
1148 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1149 	 */
1150 }
1151 
1152 static inline struct inode *orphan_list_entry(struct list_head *l)
1153 {
1154 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1155 }
1156 
1157 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1158 {
1159 	struct list_head *l;
1160 
1161 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1162 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1163 
1164 	printk(KERN_ERR "sb_info orphan list:\n");
1165 	list_for_each(l, &sbi->s_orphan) {
1166 		struct inode *inode = orphan_list_entry(l);
1167 		printk(KERN_ERR "  "
1168 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1169 		       inode->i_sb->s_id, inode->i_ino, inode,
1170 		       inode->i_mode, inode->i_nlink,
1171 		       NEXT_ORPHAN(inode));
1172 	}
1173 }
1174 
1175 #ifdef CONFIG_QUOTA
1176 static int ext4_quota_off(struct super_block *sb, int type);
1177 
1178 static inline void ext4_quotas_off(struct super_block *sb, int type)
1179 {
1180 	BUG_ON(type > EXT4_MAXQUOTAS);
1181 
1182 	/* Use our quota_off function to clear inode flags etc. */
1183 	for (type--; type >= 0; type--)
1184 		ext4_quota_off(sb, type);
1185 }
1186 
1187 /*
1188  * This is a helper function which is used in the mount/remount
1189  * codepaths (which holds s_umount) to fetch the quota file name.
1190  */
1191 static inline char *get_qf_name(struct super_block *sb,
1192 				struct ext4_sb_info *sbi,
1193 				int type)
1194 {
1195 	return rcu_dereference_protected(sbi->s_qf_names[type],
1196 					 lockdep_is_held(&sb->s_umount));
1197 }
1198 #else
1199 static inline void ext4_quotas_off(struct super_block *sb, int type)
1200 {
1201 }
1202 #endif
1203 
1204 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1205 {
1206 	ext4_fsblk_t block;
1207 	int err;
1208 
1209 	block = ext4_count_free_clusters(sbi->s_sb);
1210 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1211 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1212 				  GFP_KERNEL);
1213 	if (!err) {
1214 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1215 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1216 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1217 					  GFP_KERNEL);
1218 	}
1219 	if (!err)
1220 		err = percpu_counter_init(&sbi->s_dirs_counter,
1221 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1222 	if (!err)
1223 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1224 					  GFP_KERNEL);
1225 	if (!err)
1226 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1227 					  GFP_KERNEL);
1228 	if (!err)
1229 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1230 
1231 	if (err)
1232 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1233 
1234 	return err;
1235 }
1236 
1237 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1238 {
1239 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1240 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1241 	percpu_counter_destroy(&sbi->s_dirs_counter);
1242 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1243 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1244 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1245 }
1246 
1247 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1248 {
1249 	struct buffer_head **group_desc;
1250 	int i;
1251 
1252 	rcu_read_lock();
1253 	group_desc = rcu_dereference(sbi->s_group_desc);
1254 	for (i = 0; i < sbi->s_gdb_count; i++)
1255 		brelse(group_desc[i]);
1256 	kvfree(group_desc);
1257 	rcu_read_unlock();
1258 }
1259 
1260 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1261 {
1262 	struct flex_groups **flex_groups;
1263 	int i;
1264 
1265 	rcu_read_lock();
1266 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1267 	if (flex_groups) {
1268 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1269 			kvfree(flex_groups[i]);
1270 		kvfree(flex_groups);
1271 	}
1272 	rcu_read_unlock();
1273 }
1274 
1275 static void ext4_put_super(struct super_block *sb)
1276 {
1277 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1278 	struct ext4_super_block *es = sbi->s_es;
1279 	int aborted = 0;
1280 	int err;
1281 
1282 	/*
1283 	 * Unregister sysfs before destroying jbd2 journal.
1284 	 * Since we could still access attr_journal_task attribute via sysfs
1285 	 * path which could have sbi->s_journal->j_task as NULL
1286 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1287 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1288 	 * read metadata verify failed then will queue error work.
1289 	 * update_super_work will call start_this_handle may trigger
1290 	 * BUG_ON.
1291 	 */
1292 	ext4_unregister_sysfs(sb);
1293 
1294 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1295 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1296 			 &sb->s_uuid);
1297 
1298 	ext4_unregister_li_request(sb);
1299 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1300 
1301 	destroy_workqueue(sbi->rsv_conversion_wq);
1302 	ext4_release_orphan_info(sb);
1303 
1304 	if (sbi->s_journal) {
1305 		aborted = is_journal_aborted(sbi->s_journal);
1306 		err = ext4_journal_destroy(sbi, sbi->s_journal);
1307 		if ((err < 0) && !aborted) {
1308 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1309 		}
1310 	} else
1311 		flush_work(&sbi->s_sb_upd_work);
1312 
1313 	ext4_es_unregister_shrinker(sbi);
1314 	timer_shutdown_sync(&sbi->s_err_report);
1315 	ext4_release_system_zone(sb);
1316 	ext4_mb_release(sb);
1317 	ext4_ext_release(sb);
1318 
1319 	if (!ext4_emergency_state(sb) && !sb_rdonly(sb)) {
1320 		if (!aborted) {
1321 			ext4_clear_feature_journal_needs_recovery(sb);
1322 			ext4_clear_feature_orphan_present(sb);
1323 			es->s_state = cpu_to_le16(sbi->s_mount_state);
1324 		}
1325 		ext4_commit_super(sb);
1326 	}
1327 
1328 	ext4_group_desc_free(sbi);
1329 	ext4_flex_groups_free(sbi);
1330 
1331 	WARN_ON_ONCE(!(sbi->s_mount_state & EXT4_ERROR_FS) &&
1332 		     percpu_counter_sum(&sbi->s_dirtyclusters_counter));
1333 	ext4_percpu_param_destroy(sbi);
1334 #ifdef CONFIG_QUOTA
1335 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1336 		kfree(get_qf_name(sb, sbi, i));
1337 #endif
1338 
1339 	/* Debugging code just in case the in-memory inode orphan list
1340 	 * isn't empty.  The on-disk one can be non-empty if we've
1341 	 * detected an error and taken the fs readonly, but the
1342 	 * in-memory list had better be clean by this point. */
1343 	if (!list_empty(&sbi->s_orphan))
1344 		dump_orphan_list(sb, sbi);
1345 	ASSERT(list_empty(&sbi->s_orphan));
1346 
1347 	sync_blockdev(sb->s_bdev);
1348 	invalidate_bdev(sb->s_bdev);
1349 	if (sbi->s_journal_bdev_file) {
1350 		/*
1351 		 * Invalidate the journal device's buffers.  We don't want them
1352 		 * floating about in memory - the physical journal device may
1353 		 * hotswapped, and it breaks the `ro-after' testing code.
1354 		 */
1355 		sync_blockdev(file_bdev(sbi->s_journal_bdev_file));
1356 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
1357 	}
1358 
1359 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1360 	sbi->s_ea_inode_cache = NULL;
1361 
1362 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1363 	sbi->s_ea_block_cache = NULL;
1364 
1365 	ext4_stop_mmpd(sbi);
1366 
1367 	brelse(sbi->s_sbh);
1368 	sb->s_fs_info = NULL;
1369 	/*
1370 	 * Now that we are completely done shutting down the
1371 	 * superblock, we need to actually destroy the kobject.
1372 	 */
1373 	kobject_put(&sbi->s_kobj);
1374 	wait_for_completion(&sbi->s_kobj_unregister);
1375 	kfree(sbi->s_blockgroup_lock);
1376 	fs_put_dax(sbi->s_daxdev, NULL);
1377 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1378 #if IS_ENABLED(CONFIG_UNICODE)
1379 	utf8_unload(sb->s_encoding);
1380 #endif
1381 	kfree(sbi);
1382 }
1383 
1384 static struct kmem_cache *ext4_inode_cachep;
1385 
1386 /*
1387  * Called inside transaction, so use GFP_NOFS
1388  */
1389 static struct inode *ext4_alloc_inode(struct super_block *sb)
1390 {
1391 	struct ext4_inode_info *ei;
1392 
1393 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1394 	if (!ei)
1395 		return NULL;
1396 
1397 	inode_set_iversion(&ei->vfs_inode, 1);
1398 	ei->i_flags = 0;
1399 	ext4_clear_state_flags(ei);	/* Only relevant on 32-bit archs */
1400 	spin_lock_init(&ei->i_raw_lock);
1401 	ei->i_prealloc_node = RB_ROOT;
1402 	atomic_set(&ei->i_prealloc_active, 0);
1403 	rwlock_init(&ei->i_prealloc_lock);
1404 	ext4_es_init_tree(&ei->i_es_tree);
1405 	rwlock_init(&ei->i_es_lock);
1406 	INIT_LIST_HEAD(&ei->i_es_list);
1407 	ei->i_es_all_nr = 0;
1408 	ei->i_es_shk_nr = 0;
1409 	ei->i_es_shrink_lblk = 0;
1410 	ei->i_es_seq = 0;
1411 	ei->i_reserved_data_blocks = 0;
1412 	spin_lock_init(&(ei->i_block_reservation_lock));
1413 	ext4_init_pending_tree(&ei->i_pending_tree);
1414 #ifdef CONFIG_QUOTA
1415 	ei->i_reserved_quota = 0;
1416 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1417 #endif
1418 	ei->jinode = NULL;
1419 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1420 	spin_lock_init(&ei->i_completed_io_lock);
1421 	ei->i_sync_tid = 0;
1422 	ei->i_datasync_tid = 0;
1423 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1424 	ext4_fc_init_inode(&ei->vfs_inode);
1425 	spin_lock_init(&ei->i_fc_lock);
1426 	return &ei->vfs_inode;
1427 }
1428 
1429 static int ext4_drop_inode(struct inode *inode)
1430 {
1431 	int drop = inode_generic_drop(inode);
1432 
1433 	if (!drop)
1434 		drop = fscrypt_drop_inode(inode);
1435 
1436 	trace_ext4_drop_inode(inode, drop);
1437 	return drop;
1438 }
1439 
1440 static void ext4_free_in_core_inode(struct inode *inode)
1441 {
1442 	fscrypt_free_inode(inode);
1443 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1444 		pr_warn("%s: inode %ld still in fc list",
1445 			__func__, inode->i_ino);
1446 	}
1447 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1448 }
1449 
1450 static void ext4_destroy_inode(struct inode *inode)
1451 {
1452 	if (ext4_inode_orphan_tracked(inode)) {
1453 		ext4_msg(inode->i_sb, KERN_ERR,
1454 			 "Inode %lu (%p): inode tracked as orphan!",
1455 			 inode->i_ino, EXT4_I(inode));
1456 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1457 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1458 				true);
1459 		dump_stack();
1460 	}
1461 
1462 	if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
1463 	    WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
1464 		ext4_msg(inode->i_sb, KERN_ERR,
1465 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1466 			 inode->i_ino, EXT4_I(inode),
1467 			 EXT4_I(inode)->i_reserved_data_blocks);
1468 }
1469 
1470 static void ext4_shutdown(struct super_block *sb)
1471 {
1472        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1473 }
1474 
1475 static void init_once(void *foo)
1476 {
1477 	struct ext4_inode_info *ei = foo;
1478 
1479 	INIT_LIST_HEAD(&ei->i_orphan);
1480 	init_rwsem(&ei->xattr_sem);
1481 	init_rwsem(&ei->i_data_sem);
1482 	inode_init_once(&ei->vfs_inode);
1483 	ext4_fc_init_inode(&ei->vfs_inode);
1484 #ifdef CONFIG_FS_ENCRYPTION
1485 	ei->i_crypt_info = NULL;
1486 #endif
1487 #ifdef CONFIG_FS_VERITY
1488 	ei->i_verity_info = NULL;
1489 #endif
1490 }
1491 
1492 static int __init init_inodecache(void)
1493 {
1494 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1495 				sizeof(struct ext4_inode_info), 0,
1496 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
1497 				offsetof(struct ext4_inode_info, i_data),
1498 				sizeof_field(struct ext4_inode_info, i_data),
1499 				init_once);
1500 	if (ext4_inode_cachep == NULL)
1501 		return -ENOMEM;
1502 	return 0;
1503 }
1504 
1505 static void destroy_inodecache(void)
1506 {
1507 	/*
1508 	 * Make sure all delayed rcu free inodes are flushed before we
1509 	 * destroy cache.
1510 	 */
1511 	rcu_barrier();
1512 	kmem_cache_destroy(ext4_inode_cachep);
1513 }
1514 
1515 void ext4_clear_inode(struct inode *inode)
1516 {
1517 	ext4_fc_del(inode);
1518 	invalidate_inode_buffers(inode);
1519 	clear_inode(inode);
1520 	ext4_discard_preallocations(inode);
1521 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1522 	dquot_drop(inode);
1523 	if (EXT4_I(inode)->jinode) {
1524 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1525 					       EXT4_I(inode)->jinode);
1526 		jbd2_free_inode(EXT4_I(inode)->jinode);
1527 		EXT4_I(inode)->jinode = NULL;
1528 	}
1529 	fscrypt_put_encryption_info(inode);
1530 	fsverity_cleanup_inode(inode);
1531 }
1532 
1533 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1534 					u64 ino, u32 generation)
1535 {
1536 	struct inode *inode;
1537 
1538 	/*
1539 	 * Currently we don't know the generation for parent directory, so
1540 	 * a generation of 0 means "accept any"
1541 	 */
1542 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1543 	if (IS_ERR(inode))
1544 		return ERR_CAST(inode);
1545 	if (generation && inode->i_generation != generation) {
1546 		iput(inode);
1547 		return ERR_PTR(-ESTALE);
1548 	}
1549 
1550 	return inode;
1551 }
1552 
1553 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1554 					int fh_len, int fh_type)
1555 {
1556 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1557 				    ext4_nfs_get_inode);
1558 }
1559 
1560 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1561 					int fh_len, int fh_type)
1562 {
1563 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1564 				    ext4_nfs_get_inode);
1565 }
1566 
1567 static int ext4_nfs_commit_metadata(struct inode *inode)
1568 {
1569 	struct writeback_control wbc = {
1570 		.sync_mode = WB_SYNC_ALL
1571 	};
1572 
1573 	trace_ext4_nfs_commit_metadata(inode);
1574 	return ext4_write_inode(inode, &wbc);
1575 }
1576 
1577 #ifdef CONFIG_QUOTA
1578 static const char * const quotatypes[] = INITQFNAMES;
1579 #define QTYPE2NAME(t) (quotatypes[t])
1580 
1581 static int ext4_write_dquot(struct dquot *dquot);
1582 static int ext4_acquire_dquot(struct dquot *dquot);
1583 static int ext4_release_dquot(struct dquot *dquot);
1584 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1585 static int ext4_write_info(struct super_block *sb, int type);
1586 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1587 			 const struct path *path);
1588 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1589 			       size_t len, loff_t off);
1590 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1591 				const char *data, size_t len, loff_t off);
1592 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1593 			     unsigned int flags);
1594 
1595 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1596 {
1597 	return EXT4_I(inode)->i_dquot;
1598 }
1599 
1600 static const struct dquot_operations ext4_quota_operations = {
1601 	.get_reserved_space	= ext4_get_reserved_space,
1602 	.write_dquot		= ext4_write_dquot,
1603 	.acquire_dquot		= ext4_acquire_dquot,
1604 	.release_dquot		= ext4_release_dquot,
1605 	.mark_dirty		= ext4_mark_dquot_dirty,
1606 	.write_info		= ext4_write_info,
1607 	.alloc_dquot		= dquot_alloc,
1608 	.destroy_dquot		= dquot_destroy,
1609 	.get_projid		= ext4_get_projid,
1610 	.get_inode_usage	= ext4_get_inode_usage,
1611 	.get_next_id		= dquot_get_next_id,
1612 };
1613 
1614 static const struct quotactl_ops ext4_qctl_operations = {
1615 	.quota_on	= ext4_quota_on,
1616 	.quota_off	= ext4_quota_off,
1617 	.quota_sync	= dquot_quota_sync,
1618 	.get_state	= dquot_get_state,
1619 	.set_info	= dquot_set_dqinfo,
1620 	.get_dqblk	= dquot_get_dqblk,
1621 	.set_dqblk	= dquot_set_dqblk,
1622 	.get_nextdqblk	= dquot_get_next_dqblk,
1623 };
1624 #endif
1625 
1626 static const struct super_operations ext4_sops = {
1627 	.alloc_inode	= ext4_alloc_inode,
1628 	.free_inode	= ext4_free_in_core_inode,
1629 	.destroy_inode	= ext4_destroy_inode,
1630 	.write_inode	= ext4_write_inode,
1631 	.dirty_inode	= ext4_dirty_inode,
1632 	.drop_inode	= ext4_drop_inode,
1633 	.evict_inode	= ext4_evict_inode,
1634 	.put_super	= ext4_put_super,
1635 	.sync_fs	= ext4_sync_fs,
1636 	.freeze_fs	= ext4_freeze,
1637 	.unfreeze_fs	= ext4_unfreeze,
1638 	.statfs		= ext4_statfs,
1639 	.show_options	= ext4_show_options,
1640 	.shutdown	= ext4_shutdown,
1641 #ifdef CONFIG_QUOTA
1642 	.quota_read	= ext4_quota_read,
1643 	.quota_write	= ext4_quota_write,
1644 	.get_dquots	= ext4_get_dquots,
1645 #endif
1646 };
1647 
1648 static const struct export_operations ext4_export_ops = {
1649 	.encode_fh = generic_encode_ino32_fh,
1650 	.fh_to_dentry = ext4_fh_to_dentry,
1651 	.fh_to_parent = ext4_fh_to_parent,
1652 	.get_parent = ext4_get_parent,
1653 	.commit_metadata = ext4_nfs_commit_metadata,
1654 };
1655 
1656 enum {
1657 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1658 	Opt_resgid, Opt_resuid, Opt_sb,
1659 	Opt_nouid32, Opt_debug, Opt_removed,
1660 	Opt_user_xattr, Opt_acl,
1661 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1662 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1663 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1664 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1665 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1666 	Opt_inlinecrypt,
1667 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1668 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1669 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1670 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1671 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1672 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1673 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1674 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1675 	Opt_dioread_nolock, Opt_dioread_lock,
1676 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1677 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1678 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1679 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1680 #ifdef CONFIG_EXT4_DEBUG
1681 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1682 #endif
1683 };
1684 
1685 static const struct constant_table ext4_param_errors[] = {
1686 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1687 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1688 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1689 	{}
1690 };
1691 
1692 static const struct constant_table ext4_param_data[] = {
1693 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1694 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1695 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1696 	{}
1697 };
1698 
1699 static const struct constant_table ext4_param_data_err[] = {
1700 	{"abort",	Opt_data_err_abort},
1701 	{"ignore",	Opt_data_err_ignore},
1702 	{}
1703 };
1704 
1705 static const struct constant_table ext4_param_jqfmt[] = {
1706 	{"vfsold",	QFMT_VFS_OLD},
1707 	{"vfsv0",	QFMT_VFS_V0},
1708 	{"vfsv1",	QFMT_VFS_V1},
1709 	{}
1710 };
1711 
1712 static const struct constant_table ext4_param_dax[] = {
1713 	{"always",	Opt_dax_always},
1714 	{"inode",	Opt_dax_inode},
1715 	{"never",	Opt_dax_never},
1716 	{}
1717 };
1718 
1719 /*
1720  * Mount option specification
1721  * We don't use fsparam_flag_no because of the way we set the
1722  * options and the way we show them in _ext4_show_options(). To
1723  * keep the changes to a minimum, let's keep the negative options
1724  * separate for now.
1725  */
1726 static const struct fs_parameter_spec ext4_param_specs[] = {
1727 	fsparam_flag	("bsddf",		Opt_bsd_df),
1728 	fsparam_flag	("minixdf",		Opt_minix_df),
1729 	fsparam_flag	("grpid",		Opt_grpid),
1730 	fsparam_flag	("bsdgroups",		Opt_grpid),
1731 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1732 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1733 	fsparam_gid	("resgid",		Opt_resgid),
1734 	fsparam_uid	("resuid",		Opt_resuid),
1735 	fsparam_u32	("sb",			Opt_sb),
1736 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1737 	fsparam_flag	("nouid32",		Opt_nouid32),
1738 	fsparam_flag	("debug",		Opt_debug),
1739 	fsparam_flag	("oldalloc",		Opt_removed),
1740 	fsparam_flag	("orlov",		Opt_removed),
1741 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1742 	fsparam_flag	("acl",			Opt_acl),
1743 	fsparam_flag	("norecovery",		Opt_noload),
1744 	fsparam_flag	("noload",		Opt_noload),
1745 	fsparam_flag	("bh",			Opt_removed),
1746 	fsparam_flag	("nobh",		Opt_removed),
1747 	fsparam_u32	("commit",		Opt_commit),
1748 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1749 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1750 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1751 	fsparam_bdev	("journal_path",	Opt_journal_path),
1752 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1753 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1754 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1755 	fsparam_flag	("abort",		Opt_abort),
1756 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1757 	fsparam_enum	("data_err",		Opt_data_err,
1758 						ext4_param_data_err),
1759 	fsparam_string_empty
1760 			("usrjquota",		Opt_usrjquota),
1761 	fsparam_string_empty
1762 			("grpjquota",		Opt_grpjquota),
1763 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1764 	fsparam_flag	("grpquota",		Opt_grpquota),
1765 	fsparam_flag	("quota",		Opt_quota),
1766 	fsparam_flag	("noquota",		Opt_noquota),
1767 	fsparam_flag	("usrquota",		Opt_usrquota),
1768 	fsparam_flag	("prjquota",		Opt_prjquota),
1769 	fsparam_flag	("barrier",		Opt_barrier),
1770 	fsparam_u32	("barrier",		Opt_barrier),
1771 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1772 	fsparam_flag	("i_version",		Opt_removed),
1773 	fsparam_flag	("dax",			Opt_dax),
1774 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1775 	fsparam_u32	("stripe",		Opt_stripe),
1776 	fsparam_flag	("delalloc",		Opt_delalloc),
1777 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1778 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1779 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1780 	fsparam_u32	("debug_want_extra_isize",
1781 						Opt_debug_want_extra_isize),
1782 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1783 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1784 	fsparam_flag	("block_validity",	Opt_block_validity),
1785 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1786 	fsparam_u32	("inode_readahead_blks",
1787 						Opt_inode_readahead_blks),
1788 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1789 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1790 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1791 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1792 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1793 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1794 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1795 	fsparam_flag	("discard",		Opt_discard),
1796 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1797 	fsparam_u32	("init_itable",		Opt_init_itable),
1798 	fsparam_flag	("init_itable",		Opt_init_itable),
1799 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1800 #ifdef CONFIG_EXT4_DEBUG
1801 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1802 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1803 #endif
1804 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1805 	fsparam_flag	("test_dummy_encryption",
1806 						Opt_test_dummy_encryption),
1807 	fsparam_string	("test_dummy_encryption",
1808 						Opt_test_dummy_encryption),
1809 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1810 	fsparam_flag	("nombcache",		Opt_nombcache),
1811 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1812 	fsparam_flag	("prefetch_block_bitmaps",
1813 						Opt_removed),
1814 	fsparam_flag	("no_prefetch_block_bitmaps",
1815 						Opt_no_prefetch_block_bitmaps),
1816 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1817 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1818 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1819 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1820 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1821 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1822 	{}
1823 };
1824 
1825 
1826 #define MOPT_SET	0x0001
1827 #define MOPT_CLEAR	0x0002
1828 #define MOPT_NOSUPPORT	0x0004
1829 #define MOPT_EXPLICIT	0x0008
1830 #ifdef CONFIG_QUOTA
1831 #define MOPT_Q		0
1832 #define MOPT_QFMT	0x0010
1833 #else
1834 #define MOPT_Q		MOPT_NOSUPPORT
1835 #define MOPT_QFMT	MOPT_NOSUPPORT
1836 #endif
1837 #define MOPT_NO_EXT2	0x0020
1838 #define MOPT_NO_EXT3	0x0040
1839 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1840 #define MOPT_SKIP	0x0080
1841 #define	MOPT_2		0x0100
1842 
1843 static const struct mount_opts {
1844 	int	token;
1845 	int	mount_opt;
1846 	int	flags;
1847 } ext4_mount_opts[] = {
1848 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1849 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1850 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1851 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1852 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1853 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1854 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1855 	 MOPT_EXT4_ONLY | MOPT_SET},
1856 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1857 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1858 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1859 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1860 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1861 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1862 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1863 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1864 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1865 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1866 	{Opt_commit, 0, MOPT_NO_EXT2},
1867 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1868 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1869 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1870 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1871 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1872 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1873 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1874 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1875 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1876 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1877 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1878 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1879 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1880 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1881 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1882 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1883 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1884 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1885 	{Opt_data, 0, MOPT_NO_EXT2},
1886 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1887 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1888 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1889 #else
1890 	{Opt_acl, 0, MOPT_NOSUPPORT},
1891 #endif
1892 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1893 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1894 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1895 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1896 							MOPT_SET | MOPT_Q},
1897 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1898 							MOPT_SET | MOPT_Q},
1899 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1900 							MOPT_SET | MOPT_Q},
1901 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1902 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1903 							MOPT_CLEAR | MOPT_Q},
1904 	{Opt_usrjquota, 0, MOPT_Q},
1905 	{Opt_grpjquota, 0, MOPT_Q},
1906 	{Opt_jqfmt, 0, MOPT_QFMT},
1907 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1908 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1909 	 MOPT_SET},
1910 #ifdef CONFIG_EXT4_DEBUG
1911 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1912 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1913 #endif
1914 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1915 	{Opt_err, 0, 0}
1916 };
1917 
1918 #if IS_ENABLED(CONFIG_UNICODE)
1919 static const struct ext4_sb_encodings {
1920 	__u16 magic;
1921 	char *name;
1922 	unsigned int version;
1923 } ext4_sb_encoding_map[] = {
1924 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1925 };
1926 
1927 static const struct ext4_sb_encodings *
1928 ext4_sb_read_encoding(const struct ext4_super_block *es)
1929 {
1930 	__u16 magic = le16_to_cpu(es->s_encoding);
1931 	int i;
1932 
1933 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1934 		if (magic == ext4_sb_encoding_map[i].magic)
1935 			return &ext4_sb_encoding_map[i];
1936 
1937 	return NULL;
1938 }
1939 #endif
1940 
1941 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1942 #define EXT4_SPEC_JQFMT				(1 <<  1)
1943 #define EXT4_SPEC_DATAJ				(1 <<  2)
1944 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1945 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1946 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1947 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1948 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1949 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1950 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1951 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1952 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1953 #define EXT4_SPEC_s_stripe			(1 << 13)
1954 #define EXT4_SPEC_s_resuid			(1 << 14)
1955 #define EXT4_SPEC_s_resgid			(1 << 15)
1956 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1957 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1958 #define EXT4_SPEC_s_sb_block			(1 << 18)
1959 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1960 
1961 struct ext4_fs_context {
1962 	char		*s_qf_names[EXT4_MAXQUOTAS];
1963 	struct fscrypt_dummy_policy dummy_enc_policy;
1964 	int		s_jquota_fmt;	/* Format of quota to use */
1965 #ifdef CONFIG_EXT4_DEBUG
1966 	int s_fc_debug_max_replay;
1967 #endif
1968 	unsigned short	qname_spec;
1969 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1970 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1971 	unsigned long	journal_devnum;
1972 	unsigned long	s_commit_interval;
1973 	unsigned long	s_stripe;
1974 	unsigned int	s_inode_readahead_blks;
1975 	unsigned int	s_want_extra_isize;
1976 	unsigned int	s_li_wait_mult;
1977 	unsigned int	s_max_dir_size_kb;
1978 	unsigned int	journal_ioprio;
1979 	unsigned int	vals_s_mount_opt;
1980 	unsigned int	mask_s_mount_opt;
1981 	unsigned int	vals_s_mount_opt2;
1982 	unsigned int	mask_s_mount_opt2;
1983 	unsigned int	opt_flags;	/* MOPT flags */
1984 	unsigned int	spec;
1985 	u32		s_max_batch_time;
1986 	u32		s_min_batch_time;
1987 	kuid_t		s_resuid;
1988 	kgid_t		s_resgid;
1989 	ext4_fsblk_t	s_sb_block;
1990 };
1991 
1992 static void ext4_fc_free(struct fs_context *fc)
1993 {
1994 	struct ext4_fs_context *ctx = fc->fs_private;
1995 	int i;
1996 
1997 	if (!ctx)
1998 		return;
1999 
2000 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2001 		kfree(ctx->s_qf_names[i]);
2002 
2003 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2004 	kfree(ctx);
2005 }
2006 
2007 int ext4_init_fs_context(struct fs_context *fc)
2008 {
2009 	struct ext4_fs_context *ctx;
2010 
2011 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2012 	if (!ctx)
2013 		return -ENOMEM;
2014 
2015 	fc->fs_private = ctx;
2016 	fc->ops = &ext4_context_ops;
2017 
2018 	/* i_version is always enabled now */
2019 	fc->sb_flags |= SB_I_VERSION;
2020 
2021 	return 0;
2022 }
2023 
2024 #ifdef CONFIG_QUOTA
2025 /*
2026  * Note the name of the specified quota file.
2027  */
2028 static int note_qf_name(struct fs_context *fc, int qtype,
2029 		       struct fs_parameter *param)
2030 {
2031 	struct ext4_fs_context *ctx = fc->fs_private;
2032 	char *qname;
2033 
2034 	if (param->size < 1) {
2035 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2036 		return -EINVAL;
2037 	}
2038 	if (strchr(param->string, '/')) {
2039 		ext4_msg(NULL, KERN_ERR,
2040 			 "quotafile must be on filesystem root");
2041 		return -EINVAL;
2042 	}
2043 	if (ctx->s_qf_names[qtype]) {
2044 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2045 			ext4_msg(NULL, KERN_ERR,
2046 				 "%s quota file already specified",
2047 				 QTYPE2NAME(qtype));
2048 			return -EINVAL;
2049 		}
2050 		return 0;
2051 	}
2052 
2053 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2054 	if (!qname) {
2055 		ext4_msg(NULL, KERN_ERR,
2056 			 "Not enough memory for storing quotafile name");
2057 		return -ENOMEM;
2058 	}
2059 	ctx->s_qf_names[qtype] = qname;
2060 	ctx->qname_spec |= 1 << qtype;
2061 	ctx->spec |= EXT4_SPEC_JQUOTA;
2062 	return 0;
2063 }
2064 
2065 /*
2066  * Clear the name of the specified quota file.
2067  */
2068 static int unnote_qf_name(struct fs_context *fc, int qtype)
2069 {
2070 	struct ext4_fs_context *ctx = fc->fs_private;
2071 
2072 	kfree(ctx->s_qf_names[qtype]);
2073 
2074 	ctx->s_qf_names[qtype] = NULL;
2075 	ctx->qname_spec |= 1 << qtype;
2076 	ctx->spec |= EXT4_SPEC_JQUOTA;
2077 	return 0;
2078 }
2079 #endif
2080 
2081 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2082 					    struct ext4_fs_context *ctx)
2083 {
2084 	int err;
2085 
2086 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2087 		ext4_msg(NULL, KERN_WARNING,
2088 			 "test_dummy_encryption option not supported");
2089 		return -EINVAL;
2090 	}
2091 	err = fscrypt_parse_test_dummy_encryption(param,
2092 						  &ctx->dummy_enc_policy);
2093 	if (err == -EINVAL) {
2094 		ext4_msg(NULL, KERN_WARNING,
2095 			 "Value of option \"%s\" is unrecognized", param->key);
2096 	} else if (err == -EEXIST) {
2097 		ext4_msg(NULL, KERN_WARNING,
2098 			 "Conflicting test_dummy_encryption options");
2099 		return -EINVAL;
2100 	}
2101 	return err;
2102 }
2103 
2104 #define EXT4_SET_CTX(name)						\
2105 static inline __maybe_unused						\
2106 void ctx_set_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2107 {									\
2108 	ctx->mask_s_##name |= flag;					\
2109 	ctx->vals_s_##name |= flag;					\
2110 }
2111 
2112 #define EXT4_CLEAR_CTX(name)						\
2113 static inline __maybe_unused						\
2114 void ctx_clear_##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_TEST_CTX(name)						\
2121 static inline unsigned long						\
2122 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2123 {									\
2124 	return (ctx->vals_s_##name & flag);				\
2125 }
2126 
2127 EXT4_SET_CTX(flags); /* set only */
2128 EXT4_SET_CTX(mount_opt);
2129 EXT4_CLEAR_CTX(mount_opt);
2130 EXT4_TEST_CTX(mount_opt);
2131 EXT4_SET_CTX(mount_opt2);
2132 EXT4_CLEAR_CTX(mount_opt2);
2133 EXT4_TEST_CTX(mount_opt2);
2134 
2135 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2136 {
2137 	struct ext4_fs_context *ctx = fc->fs_private;
2138 	struct fs_parse_result result;
2139 	const struct mount_opts *m;
2140 	int is_remount;
2141 	int token;
2142 
2143 	token = fs_parse(fc, ext4_param_specs, param, &result);
2144 	if (token < 0)
2145 		return token;
2146 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2147 
2148 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2149 		if (token == m->token)
2150 			break;
2151 
2152 	ctx->opt_flags |= m->flags;
2153 
2154 	if (m->flags & MOPT_EXPLICIT) {
2155 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2156 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2157 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2158 			ctx_set_mount_opt2(ctx,
2159 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2160 		} else
2161 			return -EINVAL;
2162 	}
2163 
2164 	if (m->flags & MOPT_NOSUPPORT) {
2165 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2166 			 param->key);
2167 		return 0;
2168 	}
2169 
2170 	switch (token) {
2171 #ifdef CONFIG_QUOTA
2172 	case Opt_usrjquota:
2173 		if (!*param->string)
2174 			return unnote_qf_name(fc, USRQUOTA);
2175 		else
2176 			return note_qf_name(fc, USRQUOTA, param);
2177 	case Opt_grpjquota:
2178 		if (!*param->string)
2179 			return unnote_qf_name(fc, GRPQUOTA);
2180 		else
2181 			return note_qf_name(fc, GRPQUOTA, param);
2182 #endif
2183 	case Opt_sb:
2184 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2185 			ext4_msg(NULL, KERN_WARNING,
2186 				 "Ignoring %s option on remount", param->key);
2187 		} else {
2188 			ctx->s_sb_block = result.uint_32;
2189 			ctx->spec |= EXT4_SPEC_s_sb_block;
2190 		}
2191 		return 0;
2192 	case Opt_removed:
2193 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2194 			 param->key);
2195 		return 0;
2196 	case Opt_inlinecrypt:
2197 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2198 		ctx_set_flags(ctx, SB_INLINECRYPT);
2199 #else
2200 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2201 #endif
2202 		return 0;
2203 	case Opt_errors:
2204 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2205 		ctx_set_mount_opt(ctx, result.uint_32);
2206 		return 0;
2207 #ifdef CONFIG_QUOTA
2208 	case Opt_jqfmt:
2209 		ctx->s_jquota_fmt = result.uint_32;
2210 		ctx->spec |= EXT4_SPEC_JQFMT;
2211 		return 0;
2212 #endif
2213 	case Opt_data:
2214 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2215 		ctx_set_mount_opt(ctx, result.uint_32);
2216 		ctx->spec |= EXT4_SPEC_DATAJ;
2217 		return 0;
2218 	case Opt_commit:
2219 		if (result.uint_32 == 0)
2220 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2221 		else if (result.uint_32 > INT_MAX / HZ) {
2222 			ext4_msg(NULL, KERN_ERR,
2223 				 "Invalid commit interval %d, "
2224 				 "must be smaller than %d",
2225 				 result.uint_32, INT_MAX / HZ);
2226 			return -EINVAL;
2227 		}
2228 		ctx->s_commit_interval = HZ * result.uint_32;
2229 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2230 		return 0;
2231 	case Opt_debug_want_extra_isize:
2232 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2233 			ext4_msg(NULL, KERN_ERR,
2234 				 "Invalid want_extra_isize %d", result.uint_32);
2235 			return -EINVAL;
2236 		}
2237 		ctx->s_want_extra_isize = result.uint_32;
2238 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2239 		return 0;
2240 	case Opt_max_batch_time:
2241 		ctx->s_max_batch_time = result.uint_32;
2242 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2243 		return 0;
2244 	case Opt_min_batch_time:
2245 		ctx->s_min_batch_time = result.uint_32;
2246 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2247 		return 0;
2248 	case Opt_inode_readahead_blks:
2249 		if (result.uint_32 &&
2250 		    (result.uint_32 > (1 << 30) ||
2251 		     !is_power_of_2(result.uint_32))) {
2252 			ext4_msg(NULL, KERN_ERR,
2253 				 "EXT4-fs: inode_readahead_blks must be "
2254 				 "0 or a power of 2 smaller than 2^31");
2255 			return -EINVAL;
2256 		}
2257 		ctx->s_inode_readahead_blks = result.uint_32;
2258 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2259 		return 0;
2260 	case Opt_init_itable:
2261 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2262 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2263 		if (param->type == fs_value_is_string)
2264 			ctx->s_li_wait_mult = result.uint_32;
2265 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2266 		return 0;
2267 	case Opt_max_dir_size_kb:
2268 		ctx->s_max_dir_size_kb = result.uint_32;
2269 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2270 		return 0;
2271 #ifdef CONFIG_EXT4_DEBUG
2272 	case Opt_fc_debug_max_replay:
2273 		ctx->s_fc_debug_max_replay = result.uint_32;
2274 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2275 		return 0;
2276 #endif
2277 	case Opt_stripe:
2278 		ctx->s_stripe = result.uint_32;
2279 		ctx->spec |= EXT4_SPEC_s_stripe;
2280 		return 0;
2281 	case Opt_resuid:
2282 		ctx->s_resuid = result.uid;
2283 		ctx->spec |= EXT4_SPEC_s_resuid;
2284 		return 0;
2285 	case Opt_resgid:
2286 		ctx->s_resgid = result.gid;
2287 		ctx->spec |= EXT4_SPEC_s_resgid;
2288 		return 0;
2289 	case Opt_journal_dev:
2290 		if (is_remount) {
2291 			ext4_msg(NULL, KERN_ERR,
2292 				 "Cannot specify journal on remount");
2293 			return -EINVAL;
2294 		}
2295 		ctx->journal_devnum = result.uint_32;
2296 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2297 		return 0;
2298 	case Opt_journal_path:
2299 	{
2300 		struct inode *journal_inode;
2301 		struct path path;
2302 		int error;
2303 
2304 		if (is_remount) {
2305 			ext4_msg(NULL, KERN_ERR,
2306 				 "Cannot specify journal on remount");
2307 			return -EINVAL;
2308 		}
2309 
2310 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2311 		if (error) {
2312 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2313 				 "journal device path");
2314 			return -EINVAL;
2315 		}
2316 
2317 		journal_inode = d_inode(path.dentry);
2318 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2319 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2320 		path_put(&path);
2321 		return 0;
2322 	}
2323 	case Opt_journal_ioprio:
2324 		if (result.uint_32 > 7) {
2325 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2326 				 " (must be 0-7)");
2327 			return -EINVAL;
2328 		}
2329 		ctx->journal_ioprio =
2330 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2331 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2332 		return 0;
2333 	case Opt_test_dummy_encryption:
2334 		return ext4_parse_test_dummy_encryption(param, ctx);
2335 	case Opt_dax:
2336 	case Opt_dax_type:
2337 #ifdef CONFIG_FS_DAX
2338 	{
2339 		int type = (token == Opt_dax) ?
2340 			   Opt_dax : result.uint_32;
2341 
2342 		switch (type) {
2343 		case Opt_dax:
2344 		case Opt_dax_always:
2345 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2346 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2347 			break;
2348 		case Opt_dax_never:
2349 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2350 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2351 			break;
2352 		case Opt_dax_inode:
2353 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2354 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2355 			/* Strictly for printing options */
2356 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2357 			break;
2358 		}
2359 		return 0;
2360 	}
2361 #else
2362 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2363 		return -EINVAL;
2364 #endif
2365 	case Opt_data_err:
2366 		if (result.uint_32 == Opt_data_err_abort)
2367 			ctx_set_mount_opt(ctx, m->mount_opt);
2368 		else if (result.uint_32 == Opt_data_err_ignore)
2369 			ctx_clear_mount_opt(ctx, m->mount_opt);
2370 		return 0;
2371 	case Opt_mb_optimize_scan:
2372 		if (result.int_32 == 1) {
2373 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2374 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2375 		} else if (result.int_32 == 0) {
2376 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2377 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2378 		} else {
2379 			ext4_msg(NULL, KERN_WARNING,
2380 				 "mb_optimize_scan should be set to 0 or 1.");
2381 			return -EINVAL;
2382 		}
2383 		return 0;
2384 	}
2385 
2386 	/*
2387 	 * At this point we should only be getting options requiring MOPT_SET,
2388 	 * or MOPT_CLEAR. Anything else is a bug
2389 	 */
2390 	if (m->token == Opt_err) {
2391 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2392 			 param->key);
2393 		WARN_ON(1);
2394 		return -EINVAL;
2395 	}
2396 
2397 	else {
2398 		unsigned int set = 0;
2399 
2400 		if ((param->type == fs_value_is_flag) ||
2401 		    result.uint_32 > 0)
2402 			set = 1;
2403 
2404 		if (m->flags & MOPT_CLEAR)
2405 			set = !set;
2406 		else if (unlikely(!(m->flags & MOPT_SET))) {
2407 			ext4_msg(NULL, KERN_WARNING,
2408 				 "buggy handling of option %s",
2409 				 param->key);
2410 			WARN_ON(1);
2411 			return -EINVAL;
2412 		}
2413 		if (m->flags & MOPT_2) {
2414 			if (set != 0)
2415 				ctx_set_mount_opt2(ctx, m->mount_opt);
2416 			else
2417 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2418 		} else {
2419 			if (set != 0)
2420 				ctx_set_mount_opt(ctx, m->mount_opt);
2421 			else
2422 				ctx_clear_mount_opt(ctx, m->mount_opt);
2423 		}
2424 	}
2425 
2426 	return 0;
2427 }
2428 
2429 static int parse_options(struct fs_context *fc, char *options)
2430 {
2431 	struct fs_parameter param;
2432 	int ret;
2433 	char *key;
2434 
2435 	if (!options)
2436 		return 0;
2437 
2438 	while ((key = strsep(&options, ",")) != NULL) {
2439 		if (*key) {
2440 			size_t v_len = 0;
2441 			char *value = strchr(key, '=');
2442 
2443 			param.type = fs_value_is_flag;
2444 			param.string = NULL;
2445 
2446 			if (value) {
2447 				if (value == key)
2448 					continue;
2449 
2450 				*value++ = 0;
2451 				v_len = strlen(value);
2452 				param.string = kmemdup_nul(value, v_len,
2453 							   GFP_KERNEL);
2454 				if (!param.string)
2455 					return -ENOMEM;
2456 				param.type = fs_value_is_string;
2457 			}
2458 
2459 			param.key = key;
2460 			param.size = v_len;
2461 
2462 			ret = ext4_parse_param(fc, &param);
2463 			kfree(param.string);
2464 			if (ret < 0)
2465 				return ret;
2466 		}
2467 	}
2468 
2469 	ret = ext4_validate_options(fc);
2470 	if (ret < 0)
2471 		return ret;
2472 
2473 	return 0;
2474 }
2475 
2476 static int parse_apply_sb_mount_options(struct super_block *sb,
2477 					struct ext4_fs_context *m_ctx)
2478 {
2479 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2480 	char s_mount_opts[64];
2481 	struct ext4_fs_context *s_ctx = NULL;
2482 	struct fs_context *fc = NULL;
2483 	int ret = -ENOMEM;
2484 
2485 	if (!sbi->s_es->s_mount_opts[0])
2486 		return 0;
2487 
2488 	if (strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts) < 0)
2489 		return -E2BIG;
2490 
2491 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2492 	if (!fc)
2493 		return -ENOMEM;
2494 
2495 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2496 	if (!s_ctx)
2497 		goto out_free;
2498 
2499 	fc->fs_private = s_ctx;
2500 	fc->s_fs_info = sbi;
2501 
2502 	ret = parse_options(fc, s_mount_opts);
2503 	if (ret < 0)
2504 		goto parse_failed;
2505 
2506 	ret = ext4_check_opt_consistency(fc, sb);
2507 	if (ret < 0) {
2508 parse_failed:
2509 		ext4_msg(sb, KERN_WARNING,
2510 			 "failed to parse options in superblock: %s",
2511 			 s_mount_opts);
2512 		ret = 0;
2513 		goto out_free;
2514 	}
2515 
2516 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2517 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2518 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2519 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2520 
2521 	ext4_apply_options(fc, sb);
2522 	ret = 0;
2523 
2524 out_free:
2525 	ext4_fc_free(fc);
2526 	kfree(fc);
2527 	return ret;
2528 }
2529 
2530 static void ext4_apply_quota_options(struct fs_context *fc,
2531 				     struct super_block *sb)
2532 {
2533 #ifdef CONFIG_QUOTA
2534 	bool quota_feature = ext4_has_feature_quota(sb);
2535 	struct ext4_fs_context *ctx = fc->fs_private;
2536 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2537 	char *qname;
2538 	int i;
2539 
2540 	if (quota_feature)
2541 		return;
2542 
2543 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2544 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2545 			if (!(ctx->qname_spec & (1 << i)))
2546 				continue;
2547 
2548 			qname = ctx->s_qf_names[i]; /* May be NULL */
2549 			if (qname)
2550 				set_opt(sb, QUOTA);
2551 			ctx->s_qf_names[i] = NULL;
2552 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2553 						lockdep_is_held(&sb->s_umount));
2554 			if (qname)
2555 				kfree_rcu_mightsleep(qname);
2556 		}
2557 	}
2558 
2559 	if (ctx->spec & EXT4_SPEC_JQFMT)
2560 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2561 #endif
2562 }
2563 
2564 /*
2565  * Check quota settings consistency.
2566  */
2567 static int ext4_check_quota_consistency(struct fs_context *fc,
2568 					struct super_block *sb)
2569 {
2570 #ifdef CONFIG_QUOTA
2571 	struct ext4_fs_context *ctx = fc->fs_private;
2572 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2573 	bool quota_feature = ext4_has_feature_quota(sb);
2574 	bool quota_loaded = sb_any_quota_loaded(sb);
2575 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2576 	int quota_flags, i;
2577 
2578 	/*
2579 	 * We do the test below only for project quotas. 'usrquota' and
2580 	 * 'grpquota' mount options are allowed even without quota feature
2581 	 * to support legacy quotas in quota files.
2582 	 */
2583 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2584 	    !ext4_has_feature_project(sb)) {
2585 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2586 			 "Cannot enable project quota enforcement.");
2587 		return -EINVAL;
2588 	}
2589 
2590 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2591 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2592 	if (quota_loaded &&
2593 	    ctx->mask_s_mount_opt & quota_flags &&
2594 	    !ctx_test_mount_opt(ctx, quota_flags))
2595 		goto err_quota_change;
2596 
2597 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2598 
2599 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2600 			if (!(ctx->qname_spec & (1 << i)))
2601 				continue;
2602 
2603 			if (quota_loaded &&
2604 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2605 				goto err_jquota_change;
2606 
2607 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2608 			    strcmp(get_qf_name(sb, sbi, i),
2609 				   ctx->s_qf_names[i]) != 0)
2610 				goto err_jquota_specified;
2611 		}
2612 
2613 		if (quota_feature) {
2614 			ext4_msg(NULL, KERN_INFO,
2615 				 "Journaled quota options ignored when "
2616 				 "QUOTA feature is enabled");
2617 			return 0;
2618 		}
2619 	}
2620 
2621 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2622 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2623 			goto err_jquota_change;
2624 		if (quota_feature) {
2625 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2626 				 "ignored when QUOTA feature is enabled");
2627 			return 0;
2628 		}
2629 	}
2630 
2631 	/* Make sure we don't mix old and new quota format */
2632 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2633 		       ctx->s_qf_names[USRQUOTA]);
2634 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2635 		       ctx->s_qf_names[GRPQUOTA]);
2636 
2637 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2638 		    test_opt(sb, USRQUOTA));
2639 
2640 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2641 		    test_opt(sb, GRPQUOTA));
2642 
2643 	if (usr_qf_name) {
2644 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2645 		usrquota = false;
2646 	}
2647 	if (grp_qf_name) {
2648 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2649 		grpquota = false;
2650 	}
2651 
2652 	if (usr_qf_name || grp_qf_name) {
2653 		if (usrquota || grpquota) {
2654 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2655 				 "format mixing");
2656 			return -EINVAL;
2657 		}
2658 
2659 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2660 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2661 				 "not specified");
2662 			return -EINVAL;
2663 		}
2664 	}
2665 
2666 	return 0;
2667 
2668 err_quota_change:
2669 	ext4_msg(NULL, KERN_ERR,
2670 		 "Cannot change quota options when quota turned on");
2671 	return -EINVAL;
2672 err_jquota_change:
2673 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2674 		 "options when quota turned on");
2675 	return -EINVAL;
2676 err_jquota_specified:
2677 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2678 		 QTYPE2NAME(i));
2679 	return -EINVAL;
2680 #else
2681 	return 0;
2682 #endif
2683 }
2684 
2685 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2686 					    struct super_block *sb)
2687 {
2688 	const struct ext4_fs_context *ctx = fc->fs_private;
2689 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2690 
2691 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2692 		return 0;
2693 
2694 	if (!ext4_has_feature_encrypt(sb)) {
2695 		ext4_msg(NULL, KERN_WARNING,
2696 			 "test_dummy_encryption requires encrypt feature");
2697 		return -EINVAL;
2698 	}
2699 	/*
2700 	 * This mount option is just for testing, and it's not worthwhile to
2701 	 * implement the extra complexity (e.g. RCU protection) that would be
2702 	 * needed to allow it to be set or changed during remount.  We do allow
2703 	 * it to be specified during remount, but only if there is no change.
2704 	 */
2705 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2706 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2707 						 &ctx->dummy_enc_policy))
2708 			return 0;
2709 		ext4_msg(NULL, KERN_WARNING,
2710 			 "Can't set or change test_dummy_encryption on remount");
2711 		return -EINVAL;
2712 	}
2713 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2714 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2715 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2716 						 &ctx->dummy_enc_policy))
2717 			return 0;
2718 		ext4_msg(NULL, KERN_WARNING,
2719 			 "Conflicting test_dummy_encryption options");
2720 		return -EINVAL;
2721 	}
2722 	return 0;
2723 }
2724 
2725 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2726 					     struct super_block *sb)
2727 {
2728 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2729 	    /* if already set, it was already verified to be the same */
2730 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2731 		return;
2732 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2733 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2734 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2735 }
2736 
2737 static int ext4_check_opt_consistency(struct fs_context *fc,
2738 				      struct super_block *sb)
2739 {
2740 	struct ext4_fs_context *ctx = fc->fs_private;
2741 	struct ext4_sb_info *sbi = fc->s_fs_info;
2742 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2743 	int err;
2744 
2745 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2746 		ext4_msg(NULL, KERN_ERR,
2747 			 "Mount option(s) incompatible with ext2");
2748 		return -EINVAL;
2749 	}
2750 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2751 		ext4_msg(NULL, KERN_ERR,
2752 			 "Mount option(s) incompatible with ext3");
2753 		return -EINVAL;
2754 	}
2755 
2756 	if (ctx->s_want_extra_isize >
2757 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2758 		ext4_msg(NULL, KERN_ERR,
2759 			 "Invalid want_extra_isize %d",
2760 			 ctx->s_want_extra_isize);
2761 		return -EINVAL;
2762 	}
2763 
2764 	err = ext4_check_test_dummy_encryption(fc, sb);
2765 	if (err)
2766 		return err;
2767 
2768 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2769 		if (!sbi->s_journal) {
2770 			ext4_msg(NULL, KERN_WARNING,
2771 				 "Remounting file system with no journal "
2772 				 "so ignoring journalled data option");
2773 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2774 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2775 			   test_opt(sb, DATA_FLAGS)) {
2776 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2777 				 "on remount");
2778 			return -EINVAL;
2779 		}
2780 	}
2781 
2782 	if (is_remount) {
2783 		if (!sbi->s_journal &&
2784 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT)) {
2785 			ext4_msg(NULL, KERN_WARNING,
2786 				 "Remounting fs w/o journal so ignoring data_err option");
2787 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT);
2788 		}
2789 
2790 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2791 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2792 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2793 				 "both data=journal and dax");
2794 			return -EINVAL;
2795 		}
2796 
2797 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2798 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2799 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2800 fail_dax_change_remount:
2801 			ext4_msg(NULL, KERN_ERR, "can't change "
2802 				 "dax mount option while remounting");
2803 			return -EINVAL;
2804 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2805 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2806 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2807 			goto fail_dax_change_remount;
2808 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2809 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2810 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2811 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2812 			goto fail_dax_change_remount;
2813 		}
2814 	}
2815 
2816 	return ext4_check_quota_consistency(fc, sb);
2817 }
2818 
2819 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2820 {
2821 	struct ext4_fs_context *ctx = fc->fs_private;
2822 	struct ext4_sb_info *sbi = fc->s_fs_info;
2823 
2824 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2825 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2826 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2827 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2828 	sb->s_flags &= ~ctx->mask_s_flags;
2829 	sb->s_flags |= ctx->vals_s_flags;
2830 
2831 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2832 	APPLY(s_commit_interval);
2833 	APPLY(s_stripe);
2834 	APPLY(s_max_batch_time);
2835 	APPLY(s_min_batch_time);
2836 	APPLY(s_want_extra_isize);
2837 	APPLY(s_inode_readahead_blks);
2838 	APPLY(s_max_dir_size_kb);
2839 	APPLY(s_li_wait_mult);
2840 	APPLY(s_resgid);
2841 	APPLY(s_resuid);
2842 
2843 #ifdef CONFIG_EXT4_DEBUG
2844 	APPLY(s_fc_debug_max_replay);
2845 #endif
2846 
2847 	ext4_apply_quota_options(fc, sb);
2848 	ext4_apply_test_dummy_encryption(ctx, sb);
2849 }
2850 
2851 
2852 static int ext4_validate_options(struct fs_context *fc)
2853 {
2854 #ifdef CONFIG_QUOTA
2855 	struct ext4_fs_context *ctx = fc->fs_private;
2856 	char *usr_qf_name, *grp_qf_name;
2857 
2858 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2859 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2860 
2861 	if (usr_qf_name || grp_qf_name) {
2862 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2863 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2864 
2865 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2866 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2867 
2868 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2869 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2870 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2871 				 "format mixing");
2872 			return -EINVAL;
2873 		}
2874 	}
2875 #endif
2876 	return 1;
2877 }
2878 
2879 static inline void ext4_show_quota_options(struct seq_file *seq,
2880 					   struct super_block *sb)
2881 {
2882 #if defined(CONFIG_QUOTA)
2883 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2884 	char *usr_qf_name, *grp_qf_name;
2885 
2886 	if (sbi->s_jquota_fmt) {
2887 		char *fmtname = "";
2888 
2889 		switch (sbi->s_jquota_fmt) {
2890 		case QFMT_VFS_OLD:
2891 			fmtname = "vfsold";
2892 			break;
2893 		case QFMT_VFS_V0:
2894 			fmtname = "vfsv0";
2895 			break;
2896 		case QFMT_VFS_V1:
2897 			fmtname = "vfsv1";
2898 			break;
2899 		}
2900 		seq_printf(seq, ",jqfmt=%s", fmtname);
2901 	}
2902 
2903 	rcu_read_lock();
2904 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2905 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2906 	if (usr_qf_name)
2907 		seq_show_option(seq, "usrjquota", usr_qf_name);
2908 	if (grp_qf_name)
2909 		seq_show_option(seq, "grpjquota", grp_qf_name);
2910 	rcu_read_unlock();
2911 #endif
2912 }
2913 
2914 static const char *token2str(int token)
2915 {
2916 	const struct fs_parameter_spec *spec;
2917 
2918 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2919 		if (spec->opt == token && !spec->type)
2920 			break;
2921 	return spec->name;
2922 }
2923 
2924 /*
2925  * Show an option if
2926  *  - it's set to a non-default value OR
2927  *  - if the per-sb default is different from the global default
2928  */
2929 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2930 			      int nodefs)
2931 {
2932 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2933 	struct ext4_super_block *es = sbi->s_es;
2934 	int def_errors;
2935 	const struct mount_opts *m;
2936 	char sep = nodefs ? '\n' : ',';
2937 
2938 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2939 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2940 
2941 	if (sbi->s_sb_block != 1)
2942 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2943 
2944 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2945 		int want_set = m->flags & MOPT_SET;
2946 		int opt_2 = m->flags & MOPT_2;
2947 		unsigned int mount_opt, def_mount_opt;
2948 
2949 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2950 		    m->flags & MOPT_SKIP)
2951 			continue;
2952 
2953 		if (opt_2) {
2954 			mount_opt = sbi->s_mount_opt2;
2955 			def_mount_opt = sbi->s_def_mount_opt2;
2956 		} else {
2957 			mount_opt = sbi->s_mount_opt;
2958 			def_mount_opt = sbi->s_def_mount_opt;
2959 		}
2960 		/* skip if same as the default */
2961 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2962 			continue;
2963 		/* select Opt_noFoo vs Opt_Foo */
2964 		if ((want_set &&
2965 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2966 		    (!want_set && (mount_opt & m->mount_opt)))
2967 			continue;
2968 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2969 	}
2970 
2971 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2972 	    ext4_get_resuid(es) != EXT4_DEF_RESUID)
2973 		SEQ_OPTS_PRINT("resuid=%u",
2974 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2975 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2976 	    ext4_get_resgid(es) != EXT4_DEF_RESGID)
2977 		SEQ_OPTS_PRINT("resgid=%u",
2978 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2979 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2980 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2981 		SEQ_OPTS_PUTS("errors=remount-ro");
2982 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2983 		SEQ_OPTS_PUTS("errors=continue");
2984 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2985 		SEQ_OPTS_PUTS("errors=panic");
2986 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2987 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2988 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2989 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2990 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2991 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2992 	if (nodefs && sb->s_flags & SB_I_VERSION)
2993 		SEQ_OPTS_PUTS("i_version");
2994 	if (nodefs || sbi->s_stripe)
2995 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2996 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2997 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
2998 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2999 			SEQ_OPTS_PUTS("data=journal");
3000 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3001 			SEQ_OPTS_PUTS("data=ordered");
3002 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3003 			SEQ_OPTS_PUTS("data=writeback");
3004 	}
3005 	if (nodefs ||
3006 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3007 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3008 			       sbi->s_inode_readahead_blks);
3009 
3010 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3011 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3012 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3013 	if (nodefs || sbi->s_max_dir_size_kb)
3014 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3015 	if (test_opt(sb, DATA_ERR_ABORT))
3016 		SEQ_OPTS_PUTS("data_err=abort");
3017 
3018 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3019 
3020 	if (sb->s_flags & SB_INLINECRYPT)
3021 		SEQ_OPTS_PUTS("inlinecrypt");
3022 
3023 	if (test_opt(sb, DAX_ALWAYS)) {
3024 		if (IS_EXT2_SB(sb))
3025 			SEQ_OPTS_PUTS("dax");
3026 		else
3027 			SEQ_OPTS_PUTS("dax=always");
3028 	} else if (test_opt2(sb, DAX_NEVER)) {
3029 		SEQ_OPTS_PUTS("dax=never");
3030 	} else if (test_opt2(sb, DAX_INODE)) {
3031 		SEQ_OPTS_PUTS("dax=inode");
3032 	}
3033 
3034 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3035 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3036 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3037 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3038 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3039 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3040 	}
3041 
3042 	if (nodefs && !test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS))
3043 		SEQ_OPTS_PUTS("prefetch_block_bitmaps");
3044 
3045 	if (ext4_emergency_ro(sb))
3046 		SEQ_OPTS_PUTS("emergency_ro");
3047 
3048 	if (ext4_forced_shutdown(sb))
3049 		SEQ_OPTS_PUTS("shutdown");
3050 
3051 	ext4_show_quota_options(seq, sb);
3052 	return 0;
3053 }
3054 
3055 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3056 {
3057 	return _ext4_show_options(seq, root->d_sb, 0);
3058 }
3059 
3060 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3061 {
3062 	struct super_block *sb = seq->private;
3063 	int rc;
3064 
3065 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3066 	rc = _ext4_show_options(seq, sb, 1);
3067 	seq_putc(seq, '\n');
3068 	return rc;
3069 }
3070 
3071 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3072 			    int read_only)
3073 {
3074 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3075 	int err = 0;
3076 
3077 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3078 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3079 			 "forcing read-only mode");
3080 		err = -EROFS;
3081 		goto done;
3082 	}
3083 	if (read_only)
3084 		goto done;
3085 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3086 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3087 			 "running e2fsck is recommended");
3088 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3089 		ext4_msg(sb, KERN_WARNING,
3090 			 "warning: mounting fs with errors, "
3091 			 "running e2fsck is recommended");
3092 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3093 		 le16_to_cpu(es->s_mnt_count) >=
3094 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3095 		ext4_msg(sb, KERN_WARNING,
3096 			 "warning: maximal mount count reached, "
3097 			 "running e2fsck is recommended");
3098 	else if (le32_to_cpu(es->s_checkinterval) &&
3099 		 (ext4_get_tstamp(es, s_lastcheck) +
3100 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3101 		ext4_msg(sb, KERN_WARNING,
3102 			 "warning: checktime reached, "
3103 			 "running e2fsck is recommended");
3104 	if (!sbi->s_journal)
3105 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3106 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3107 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3108 	le16_add_cpu(&es->s_mnt_count, 1);
3109 	ext4_update_tstamp(es, s_mtime);
3110 	if (sbi->s_journal) {
3111 		ext4_set_feature_journal_needs_recovery(sb);
3112 		if (ext4_has_feature_orphan_file(sb))
3113 			ext4_set_feature_orphan_present(sb);
3114 	}
3115 
3116 	err = ext4_commit_super(sb);
3117 done:
3118 	if (test_opt(sb, DEBUG))
3119 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3120 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3121 			sb->s_blocksize,
3122 			sbi->s_groups_count,
3123 			EXT4_BLOCKS_PER_GROUP(sb),
3124 			EXT4_INODES_PER_GROUP(sb),
3125 			sbi->s_mount_opt, sbi->s_mount_opt2);
3126 	return err;
3127 }
3128 
3129 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3130 {
3131 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3132 	struct flex_groups **old_groups, **new_groups;
3133 	int size, i, j;
3134 
3135 	if (!sbi->s_log_groups_per_flex)
3136 		return 0;
3137 
3138 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3139 	if (size <= sbi->s_flex_groups_allocated)
3140 		return 0;
3141 
3142 	new_groups = kvzalloc(roundup_pow_of_two(size *
3143 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3144 	if (!new_groups) {
3145 		ext4_msg(sb, KERN_ERR,
3146 			 "not enough memory for %d flex group pointers", size);
3147 		return -ENOMEM;
3148 	}
3149 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3150 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3151 					 sizeof(struct flex_groups)),
3152 					 GFP_KERNEL);
3153 		if (!new_groups[i]) {
3154 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3155 				kvfree(new_groups[j]);
3156 			kvfree(new_groups);
3157 			ext4_msg(sb, KERN_ERR,
3158 				 "not enough memory for %d flex groups", size);
3159 			return -ENOMEM;
3160 		}
3161 	}
3162 	rcu_read_lock();
3163 	old_groups = rcu_dereference(sbi->s_flex_groups);
3164 	if (old_groups)
3165 		memcpy(new_groups, old_groups,
3166 		       (sbi->s_flex_groups_allocated *
3167 			sizeof(struct flex_groups *)));
3168 	rcu_read_unlock();
3169 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3170 	sbi->s_flex_groups_allocated = size;
3171 	if (old_groups)
3172 		ext4_kvfree_array_rcu(old_groups);
3173 	return 0;
3174 }
3175 
3176 static int ext4_fill_flex_info(struct super_block *sb)
3177 {
3178 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3179 	struct ext4_group_desc *gdp = NULL;
3180 	struct flex_groups *fg;
3181 	ext4_group_t flex_group;
3182 	int i, err;
3183 
3184 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3185 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3186 		sbi->s_log_groups_per_flex = 0;
3187 		return 1;
3188 	}
3189 
3190 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3191 	if (err)
3192 		goto failed;
3193 
3194 	for (i = 0; i < sbi->s_groups_count; i++) {
3195 		gdp = ext4_get_group_desc(sb, i, NULL);
3196 
3197 		flex_group = ext4_flex_group(sbi, i);
3198 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3199 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3200 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3201 			     &fg->free_clusters);
3202 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3203 	}
3204 
3205 	return 1;
3206 failed:
3207 	return 0;
3208 }
3209 
3210 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3211 				   struct ext4_group_desc *gdp)
3212 {
3213 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3214 	__u16 crc = 0;
3215 	__le32 le_group = cpu_to_le32(block_group);
3216 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3217 
3218 	if (ext4_has_feature_metadata_csum(sbi->s_sb)) {
3219 		/* Use new metadata_csum algorithm */
3220 		__u32 csum32;
3221 		__u16 dummy_csum = 0;
3222 
3223 		csum32 = ext4_chksum(sbi->s_csum_seed, (__u8 *)&le_group,
3224 				     sizeof(le_group));
3225 		csum32 = ext4_chksum(csum32, (__u8 *)gdp, offset);
3226 		csum32 = ext4_chksum(csum32, (__u8 *)&dummy_csum,
3227 				     sizeof(dummy_csum));
3228 		offset += sizeof(dummy_csum);
3229 		if (offset < sbi->s_desc_size)
3230 			csum32 = ext4_chksum(csum32, (__u8 *)gdp + offset,
3231 					     sbi->s_desc_size - offset);
3232 
3233 		crc = csum32 & 0xFFFF;
3234 		goto out;
3235 	}
3236 
3237 	/* old crc16 code */
3238 	if (!ext4_has_feature_gdt_csum(sb))
3239 		return 0;
3240 
3241 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3242 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3243 	crc = crc16(crc, (__u8 *)gdp, offset);
3244 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3245 	/* for checksum of struct ext4_group_desc do the rest...*/
3246 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3247 		crc = crc16(crc, (__u8 *)gdp + offset,
3248 			    sbi->s_desc_size - offset);
3249 
3250 out:
3251 	return cpu_to_le16(crc);
3252 }
3253 
3254 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3255 				struct ext4_group_desc *gdp)
3256 {
3257 	if (ext4_has_group_desc_csum(sb) &&
3258 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3259 		return 0;
3260 
3261 	return 1;
3262 }
3263 
3264 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3265 			      struct ext4_group_desc *gdp)
3266 {
3267 	if (!ext4_has_group_desc_csum(sb))
3268 		return;
3269 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3270 }
3271 
3272 /* Called at mount-time, super-block is locked */
3273 static int ext4_check_descriptors(struct super_block *sb,
3274 				  ext4_fsblk_t sb_block,
3275 				  ext4_group_t *first_not_zeroed)
3276 {
3277 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3278 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3279 	ext4_fsblk_t last_block;
3280 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3281 	ext4_fsblk_t block_bitmap;
3282 	ext4_fsblk_t inode_bitmap;
3283 	ext4_fsblk_t inode_table;
3284 	int flexbg_flag = 0;
3285 	ext4_group_t i, grp = sbi->s_groups_count;
3286 
3287 	if (ext4_has_feature_flex_bg(sb))
3288 		flexbg_flag = 1;
3289 
3290 	ext4_debug("Checking group descriptors");
3291 
3292 	for (i = 0; i < sbi->s_groups_count; i++) {
3293 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3294 
3295 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3296 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3297 		else
3298 			last_block = first_block +
3299 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3300 
3301 		if ((grp == sbi->s_groups_count) &&
3302 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3303 			grp = i;
3304 
3305 		block_bitmap = ext4_block_bitmap(sb, gdp);
3306 		if (block_bitmap == sb_block) {
3307 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3308 				 "Block bitmap for group %u overlaps "
3309 				 "superblock", i);
3310 			if (!sb_rdonly(sb))
3311 				return 0;
3312 		}
3313 		if (block_bitmap >= sb_block + 1 &&
3314 		    block_bitmap <= last_bg_block) {
3315 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3316 				 "Block bitmap for group %u overlaps "
3317 				 "block group descriptors", i);
3318 			if (!sb_rdonly(sb))
3319 				return 0;
3320 		}
3321 		if (block_bitmap < first_block || block_bitmap > last_block) {
3322 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3323 			       "Block bitmap for group %u not in group "
3324 			       "(block %llu)!", i, block_bitmap);
3325 			return 0;
3326 		}
3327 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3328 		if (inode_bitmap == sb_block) {
3329 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3330 				 "Inode bitmap for group %u overlaps "
3331 				 "superblock", i);
3332 			if (!sb_rdonly(sb))
3333 				return 0;
3334 		}
3335 		if (inode_bitmap >= sb_block + 1 &&
3336 		    inode_bitmap <= last_bg_block) {
3337 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3338 				 "Inode bitmap for group %u overlaps "
3339 				 "block group descriptors", i);
3340 			if (!sb_rdonly(sb))
3341 				return 0;
3342 		}
3343 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3344 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3345 			       "Inode bitmap for group %u not in group "
3346 			       "(block %llu)!", i, inode_bitmap);
3347 			return 0;
3348 		}
3349 		inode_table = ext4_inode_table(sb, gdp);
3350 		if (inode_table == sb_block) {
3351 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3352 				 "Inode table for group %u overlaps "
3353 				 "superblock", i);
3354 			if (!sb_rdonly(sb))
3355 				return 0;
3356 		}
3357 		if (inode_table >= sb_block + 1 &&
3358 		    inode_table <= last_bg_block) {
3359 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3360 				 "Inode table for group %u overlaps "
3361 				 "block group descriptors", i);
3362 			if (!sb_rdonly(sb))
3363 				return 0;
3364 		}
3365 		if (inode_table < first_block ||
3366 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3367 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3368 			       "Inode table for group %u not in group "
3369 			       "(block %llu)!", i, inode_table);
3370 			return 0;
3371 		}
3372 		ext4_lock_group(sb, i);
3373 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3374 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3375 				 "Checksum for group %u failed (%u!=%u)",
3376 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3377 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3378 			if (!sb_rdonly(sb)) {
3379 				ext4_unlock_group(sb, i);
3380 				return 0;
3381 			}
3382 		}
3383 		ext4_unlock_group(sb, i);
3384 		if (!flexbg_flag)
3385 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3386 	}
3387 	if (NULL != first_not_zeroed)
3388 		*first_not_zeroed = grp;
3389 	return 1;
3390 }
3391 
3392 /*
3393  * Maximal extent format file size.
3394  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3395  * extent format containers, within a sector_t, and within i_blocks
3396  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3397  * so that won't be a limiting factor.
3398  *
3399  * However there is other limiting factor. We do store extents in the form
3400  * of starting block and length, hence the resulting length of the extent
3401  * covering maximum file size must fit into on-disk format containers as
3402  * well. Given that length is always by 1 unit bigger than max unit (because
3403  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3404  *
3405  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3406  */
3407 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3408 {
3409 	loff_t res;
3410 	loff_t upper_limit = MAX_LFS_FILESIZE;
3411 
3412 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3413 
3414 	if (!has_huge_files) {
3415 		upper_limit = (1LL << 32) - 1;
3416 
3417 		/* total blocks in file system block size */
3418 		upper_limit >>= (blkbits - 9);
3419 		upper_limit <<= blkbits;
3420 	}
3421 
3422 	/*
3423 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3424 	 * by one fs block, so ee_len can cover the extent of maximum file
3425 	 * size
3426 	 */
3427 	res = (1LL << 32) - 1;
3428 	res <<= blkbits;
3429 
3430 	/* Sanity check against vm- & vfs- imposed limits */
3431 	if (res > upper_limit)
3432 		res = upper_limit;
3433 
3434 	return res;
3435 }
3436 
3437 /*
3438  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3439  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3440  * We need to be 1 filesystem block less than the 2^48 sector limit.
3441  */
3442 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3443 {
3444 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3445 	int meta_blocks;
3446 	unsigned int ppb = 1 << (bits - 2);
3447 
3448 	/*
3449 	 * This is calculated to be the largest file size for a dense, block
3450 	 * mapped file such that the file's total number of 512-byte sectors,
3451 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3452 	 *
3453 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3454 	 * number of 512-byte sectors of the file.
3455 	 */
3456 	if (!has_huge_files) {
3457 		/*
3458 		 * !has_huge_files or implies that the inode i_block field
3459 		 * represents total file blocks in 2^32 512-byte sectors ==
3460 		 * size of vfs inode i_blocks * 8
3461 		 */
3462 		upper_limit = (1LL << 32) - 1;
3463 
3464 		/* total blocks in file system block size */
3465 		upper_limit >>= (bits - 9);
3466 
3467 	} else {
3468 		/*
3469 		 * We use 48 bit ext4_inode i_blocks
3470 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3471 		 * represent total number of blocks in
3472 		 * file system block size
3473 		 */
3474 		upper_limit = (1LL << 48) - 1;
3475 
3476 	}
3477 
3478 	/* Compute how many blocks we can address by block tree */
3479 	res += ppb;
3480 	res += ppb * ppb;
3481 	res += ((loff_t)ppb) * ppb * ppb;
3482 	/* Compute how many metadata blocks are needed */
3483 	meta_blocks = 1;
3484 	meta_blocks += 1 + ppb;
3485 	meta_blocks += 1 + ppb + ppb * ppb;
3486 	/* Does block tree limit file size? */
3487 	if (res + meta_blocks <= upper_limit)
3488 		goto check_lfs;
3489 
3490 	res = upper_limit;
3491 	/* How many metadata blocks are needed for addressing upper_limit? */
3492 	upper_limit -= EXT4_NDIR_BLOCKS;
3493 	/* indirect blocks */
3494 	meta_blocks = 1;
3495 	upper_limit -= ppb;
3496 	/* double indirect blocks */
3497 	if (upper_limit < ppb * ppb) {
3498 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3499 		res -= meta_blocks;
3500 		goto check_lfs;
3501 	}
3502 	meta_blocks += 1 + ppb;
3503 	upper_limit -= ppb * ppb;
3504 	/* tripple indirect blocks for the rest */
3505 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3506 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3507 	res -= meta_blocks;
3508 check_lfs:
3509 	res <<= bits;
3510 	if (res > MAX_LFS_FILESIZE)
3511 		res = MAX_LFS_FILESIZE;
3512 
3513 	return res;
3514 }
3515 
3516 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3517 				   ext4_fsblk_t logical_sb_block, int nr)
3518 {
3519 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3520 	ext4_group_t bg, first_meta_bg;
3521 	int has_super = 0;
3522 
3523 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3524 
3525 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3526 		return logical_sb_block + nr + 1;
3527 	bg = sbi->s_desc_per_block * nr;
3528 	if (ext4_bg_has_super(sb, bg))
3529 		has_super = 1;
3530 
3531 	/*
3532 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3533 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3534 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3535 	 * compensate.
3536 	 */
3537 	if (sb->s_blocksize == 1024 && nr == 0 &&
3538 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3539 		has_super++;
3540 
3541 	return (has_super + ext4_group_first_block_no(sb, bg));
3542 }
3543 
3544 /**
3545  * ext4_get_stripe_size: Get the stripe size.
3546  * @sbi: In memory super block info
3547  *
3548  * If we have specified it via mount option, then
3549  * use the mount option value. If the value specified at mount time is
3550  * greater than the blocks per group use the super block value.
3551  * If the super block value is greater than blocks per group return 0.
3552  * Allocator needs it be less than blocks per group.
3553  *
3554  */
3555 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3556 {
3557 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3558 	unsigned long stripe_width =
3559 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3560 	int ret;
3561 
3562 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3563 		ret = sbi->s_stripe;
3564 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3565 		ret = stripe_width;
3566 	else if (stride && stride <= sbi->s_blocks_per_group)
3567 		ret = stride;
3568 	else
3569 		ret = 0;
3570 
3571 	/*
3572 	 * If the stripe width is 1, this makes no sense and
3573 	 * we set it to 0 to turn off stripe handling code.
3574 	 */
3575 	if (ret <= 1)
3576 		ret = 0;
3577 
3578 	return ret;
3579 }
3580 
3581 /*
3582  * Check whether this filesystem can be mounted based on
3583  * the features present and the RDONLY/RDWR mount requested.
3584  * Returns 1 if this filesystem can be mounted as requested,
3585  * 0 if it cannot be.
3586  */
3587 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3588 {
3589 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3590 		ext4_msg(sb, KERN_ERR,
3591 			"Couldn't mount because of "
3592 			"unsupported optional features (%x)",
3593 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3594 			~EXT4_FEATURE_INCOMPAT_SUPP));
3595 		return 0;
3596 	}
3597 
3598 	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
3599 		ext4_msg(sb, KERN_ERR,
3600 			 "Filesystem with casefold feature cannot be "
3601 			 "mounted without CONFIG_UNICODE");
3602 		return 0;
3603 	}
3604 
3605 	if (readonly)
3606 		return 1;
3607 
3608 	if (ext4_has_feature_readonly(sb)) {
3609 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3610 		sb->s_flags |= SB_RDONLY;
3611 		return 1;
3612 	}
3613 
3614 	/* Check that feature set is OK for a read-write mount */
3615 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3616 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3617 			 "unsupported optional features (%x)",
3618 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3619 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3620 		return 0;
3621 	}
3622 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3623 		ext4_msg(sb, KERN_ERR,
3624 			 "Can't support bigalloc feature without "
3625 			 "extents feature\n");
3626 		return 0;
3627 	}
3628 
3629 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3630 	if (!readonly && (ext4_has_feature_quota(sb) ||
3631 			  ext4_has_feature_project(sb))) {
3632 		ext4_msg(sb, KERN_ERR,
3633 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3634 		return 0;
3635 	}
3636 #endif  /* CONFIG_QUOTA */
3637 	return 1;
3638 }
3639 
3640 /*
3641  * This function is called once a day if we have errors logged
3642  * on the file system
3643  */
3644 static void print_daily_error_info(struct timer_list *t)
3645 {
3646 	struct ext4_sb_info *sbi = timer_container_of(sbi, t, s_err_report);
3647 	struct super_block *sb = sbi->s_sb;
3648 	struct ext4_super_block *es = sbi->s_es;
3649 
3650 	if (es->s_error_count)
3651 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3652 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3653 			 le32_to_cpu(es->s_error_count));
3654 	if (es->s_first_error_time) {
3655 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3656 		       sb->s_id,
3657 		       ext4_get_tstamp(es, s_first_error_time),
3658 		       (int) sizeof(es->s_first_error_func),
3659 		       es->s_first_error_func,
3660 		       le32_to_cpu(es->s_first_error_line));
3661 		if (es->s_first_error_ino)
3662 			printk(KERN_CONT ": inode %u",
3663 			       le32_to_cpu(es->s_first_error_ino));
3664 		if (es->s_first_error_block)
3665 			printk(KERN_CONT ": block %llu", (unsigned long long)
3666 			       le64_to_cpu(es->s_first_error_block));
3667 		printk(KERN_CONT "\n");
3668 	}
3669 	if (es->s_last_error_time) {
3670 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3671 		       sb->s_id,
3672 		       ext4_get_tstamp(es, s_last_error_time),
3673 		       (int) sizeof(es->s_last_error_func),
3674 		       es->s_last_error_func,
3675 		       le32_to_cpu(es->s_last_error_line));
3676 		if (es->s_last_error_ino)
3677 			printk(KERN_CONT ": inode %u",
3678 			       le32_to_cpu(es->s_last_error_ino));
3679 		if (es->s_last_error_block)
3680 			printk(KERN_CONT ": block %llu", (unsigned long long)
3681 			       le64_to_cpu(es->s_last_error_block));
3682 		printk(KERN_CONT "\n");
3683 	}
3684 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3685 }
3686 
3687 /* Find next suitable group and run ext4_init_inode_table */
3688 static int ext4_run_li_request(struct ext4_li_request *elr)
3689 {
3690 	struct ext4_group_desc *gdp = NULL;
3691 	struct super_block *sb = elr->lr_super;
3692 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3693 	ext4_group_t group = elr->lr_next_group;
3694 	unsigned int prefetch_ios = 0;
3695 	int ret = 0;
3696 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3697 	u64 start_time;
3698 
3699 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3700 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3701 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3702 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3703 		if (group >= elr->lr_next_group) {
3704 			ret = 1;
3705 			if (elr->lr_first_not_zeroed != ngroups &&
3706 			    !ext4_emergency_state(sb) && !sb_rdonly(sb) &&
3707 			    test_opt(sb, INIT_INODE_TABLE)) {
3708 				elr->lr_next_group = elr->lr_first_not_zeroed;
3709 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3710 				ret = 0;
3711 			}
3712 		}
3713 		return ret;
3714 	}
3715 
3716 	for (; group < ngroups; group++) {
3717 		gdp = ext4_get_group_desc(sb, group, NULL);
3718 		if (!gdp) {
3719 			ret = 1;
3720 			break;
3721 		}
3722 
3723 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3724 			break;
3725 	}
3726 
3727 	if (group >= ngroups)
3728 		ret = 1;
3729 
3730 	if (!ret) {
3731 		start_time = ktime_get_ns();
3732 		ret = ext4_init_inode_table(sb, group,
3733 					    elr->lr_timeout ? 0 : 1);
3734 		trace_ext4_lazy_itable_init(sb, group);
3735 		if (elr->lr_timeout == 0) {
3736 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_ns() - start_time) *
3737 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3738 		}
3739 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3740 		elr->lr_next_group = group + 1;
3741 	}
3742 	return ret;
3743 }
3744 
3745 /*
3746  * Remove lr_request from the list_request and free the
3747  * request structure. Should be called with li_list_mtx held
3748  */
3749 static void ext4_remove_li_request(struct ext4_li_request *elr)
3750 {
3751 	if (!elr)
3752 		return;
3753 
3754 	list_del(&elr->lr_request);
3755 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3756 	kfree(elr);
3757 }
3758 
3759 static void ext4_unregister_li_request(struct super_block *sb)
3760 {
3761 	mutex_lock(&ext4_li_mtx);
3762 	if (!ext4_li_info) {
3763 		mutex_unlock(&ext4_li_mtx);
3764 		return;
3765 	}
3766 
3767 	mutex_lock(&ext4_li_info->li_list_mtx);
3768 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3769 	mutex_unlock(&ext4_li_info->li_list_mtx);
3770 	mutex_unlock(&ext4_li_mtx);
3771 }
3772 
3773 static struct task_struct *ext4_lazyinit_task;
3774 
3775 /*
3776  * This is the function where ext4lazyinit thread lives. It walks
3777  * through the request list searching for next scheduled filesystem.
3778  * When such a fs is found, run the lazy initialization request
3779  * (ext4_rn_li_request) and keep track of the time spend in this
3780  * function. Based on that time we compute next schedule time of
3781  * the request. When walking through the list is complete, compute
3782  * next waking time and put itself into sleep.
3783  */
3784 static int ext4_lazyinit_thread(void *arg)
3785 {
3786 	struct ext4_lazy_init *eli = arg;
3787 	struct list_head *pos, *n;
3788 	struct ext4_li_request *elr;
3789 	unsigned long next_wakeup, cur;
3790 
3791 	BUG_ON(NULL == eli);
3792 	set_freezable();
3793 
3794 cont_thread:
3795 	while (true) {
3796 		bool next_wakeup_initialized = false;
3797 
3798 		next_wakeup = 0;
3799 		mutex_lock(&eli->li_list_mtx);
3800 		if (list_empty(&eli->li_request_list)) {
3801 			mutex_unlock(&eli->li_list_mtx);
3802 			goto exit_thread;
3803 		}
3804 		list_for_each_safe(pos, n, &eli->li_request_list) {
3805 			int err = 0;
3806 			int progress = 0;
3807 			elr = list_entry(pos, struct ext4_li_request,
3808 					 lr_request);
3809 
3810 			if (time_before(jiffies, elr->lr_next_sched)) {
3811 				if (!next_wakeup_initialized ||
3812 				    time_before(elr->lr_next_sched, next_wakeup)) {
3813 					next_wakeup = elr->lr_next_sched;
3814 					next_wakeup_initialized = true;
3815 				}
3816 				continue;
3817 			}
3818 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3819 				if (sb_start_write_trylock(elr->lr_super)) {
3820 					progress = 1;
3821 					/*
3822 					 * We hold sb->s_umount, sb can not
3823 					 * be removed from the list, it is
3824 					 * now safe to drop li_list_mtx
3825 					 */
3826 					mutex_unlock(&eli->li_list_mtx);
3827 					err = ext4_run_li_request(elr);
3828 					sb_end_write(elr->lr_super);
3829 					mutex_lock(&eli->li_list_mtx);
3830 					n = pos->next;
3831 				}
3832 				up_read((&elr->lr_super->s_umount));
3833 			}
3834 			/* error, remove the lazy_init job */
3835 			if (err) {
3836 				ext4_remove_li_request(elr);
3837 				continue;
3838 			}
3839 			if (!progress) {
3840 				elr->lr_next_sched = jiffies +
3841 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3842 			}
3843 			if (!next_wakeup_initialized ||
3844 			    time_before(elr->lr_next_sched, next_wakeup)) {
3845 				next_wakeup = elr->lr_next_sched;
3846 				next_wakeup_initialized = true;
3847 			}
3848 		}
3849 		mutex_unlock(&eli->li_list_mtx);
3850 
3851 		try_to_freeze();
3852 
3853 		cur = jiffies;
3854 		if (!next_wakeup_initialized || time_after_eq(cur, next_wakeup)) {
3855 			cond_resched();
3856 			continue;
3857 		}
3858 
3859 		schedule_timeout_interruptible(next_wakeup - cur);
3860 
3861 		if (kthread_should_stop()) {
3862 			ext4_clear_request_list();
3863 			goto exit_thread;
3864 		}
3865 	}
3866 
3867 exit_thread:
3868 	/*
3869 	 * It looks like the request list is empty, but we need
3870 	 * to check it under the li_list_mtx lock, to prevent any
3871 	 * additions into it, and of course we should lock ext4_li_mtx
3872 	 * to atomically free the list and ext4_li_info, because at
3873 	 * this point another ext4 filesystem could be registering
3874 	 * new one.
3875 	 */
3876 	mutex_lock(&ext4_li_mtx);
3877 	mutex_lock(&eli->li_list_mtx);
3878 	if (!list_empty(&eli->li_request_list)) {
3879 		mutex_unlock(&eli->li_list_mtx);
3880 		mutex_unlock(&ext4_li_mtx);
3881 		goto cont_thread;
3882 	}
3883 	mutex_unlock(&eli->li_list_mtx);
3884 	kfree(ext4_li_info);
3885 	ext4_li_info = NULL;
3886 	mutex_unlock(&ext4_li_mtx);
3887 
3888 	return 0;
3889 }
3890 
3891 static void ext4_clear_request_list(void)
3892 {
3893 	struct list_head *pos, *n;
3894 	struct ext4_li_request *elr;
3895 
3896 	mutex_lock(&ext4_li_info->li_list_mtx);
3897 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3898 		elr = list_entry(pos, struct ext4_li_request,
3899 				 lr_request);
3900 		ext4_remove_li_request(elr);
3901 	}
3902 	mutex_unlock(&ext4_li_info->li_list_mtx);
3903 }
3904 
3905 static int ext4_run_lazyinit_thread(void)
3906 {
3907 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3908 					 ext4_li_info, "ext4lazyinit");
3909 	if (IS_ERR(ext4_lazyinit_task)) {
3910 		int err = PTR_ERR(ext4_lazyinit_task);
3911 		ext4_clear_request_list();
3912 		kfree(ext4_li_info);
3913 		ext4_li_info = NULL;
3914 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3915 				 "initialization thread\n",
3916 				 err);
3917 		return err;
3918 	}
3919 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3920 	return 0;
3921 }
3922 
3923 /*
3924  * Check whether it make sense to run itable init. thread or not.
3925  * If there is at least one uninitialized inode table, return
3926  * corresponding group number, else the loop goes through all
3927  * groups and return total number of groups.
3928  */
3929 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3930 {
3931 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3932 	struct ext4_group_desc *gdp = NULL;
3933 
3934 	if (!ext4_has_group_desc_csum(sb))
3935 		return ngroups;
3936 
3937 	for (group = 0; group < ngroups; group++) {
3938 		gdp = ext4_get_group_desc(sb, group, NULL);
3939 		if (!gdp)
3940 			continue;
3941 
3942 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3943 			break;
3944 	}
3945 
3946 	return group;
3947 }
3948 
3949 static int ext4_li_info_new(void)
3950 {
3951 	struct ext4_lazy_init *eli = NULL;
3952 
3953 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3954 	if (!eli)
3955 		return -ENOMEM;
3956 
3957 	INIT_LIST_HEAD(&eli->li_request_list);
3958 	mutex_init(&eli->li_list_mtx);
3959 
3960 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3961 
3962 	ext4_li_info = eli;
3963 
3964 	return 0;
3965 }
3966 
3967 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3968 					    ext4_group_t start)
3969 {
3970 	struct ext4_li_request *elr;
3971 
3972 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3973 	if (!elr)
3974 		return NULL;
3975 
3976 	elr->lr_super = sb;
3977 	elr->lr_first_not_zeroed = start;
3978 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3979 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3980 		elr->lr_next_group = start;
3981 	} else {
3982 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3983 	}
3984 
3985 	/*
3986 	 * Randomize first schedule time of the request to
3987 	 * spread the inode table initialization requests
3988 	 * better.
3989 	 */
3990 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3991 	return elr;
3992 }
3993 
3994 int ext4_register_li_request(struct super_block *sb,
3995 			     ext4_group_t first_not_zeroed)
3996 {
3997 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3998 	struct ext4_li_request *elr = NULL;
3999 	ext4_group_t ngroups = sbi->s_groups_count;
4000 	int ret = 0;
4001 
4002 	mutex_lock(&ext4_li_mtx);
4003 	if (sbi->s_li_request != NULL) {
4004 		/*
4005 		 * Reset timeout so it can be computed again, because
4006 		 * s_li_wait_mult might have changed.
4007 		 */
4008 		sbi->s_li_request->lr_timeout = 0;
4009 		goto out;
4010 	}
4011 
4012 	if (ext4_emergency_state(sb) || sb_rdonly(sb) ||
4013 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4014 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4015 		goto out;
4016 
4017 	elr = ext4_li_request_new(sb, first_not_zeroed);
4018 	if (!elr) {
4019 		ret = -ENOMEM;
4020 		goto out;
4021 	}
4022 
4023 	if (NULL == ext4_li_info) {
4024 		ret = ext4_li_info_new();
4025 		if (ret)
4026 			goto out;
4027 	}
4028 
4029 	mutex_lock(&ext4_li_info->li_list_mtx);
4030 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4031 	mutex_unlock(&ext4_li_info->li_list_mtx);
4032 
4033 	sbi->s_li_request = elr;
4034 	/*
4035 	 * set elr to NULL here since it has been inserted to
4036 	 * the request_list and the removal and free of it is
4037 	 * handled by ext4_clear_request_list from now on.
4038 	 */
4039 	elr = NULL;
4040 
4041 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4042 		ret = ext4_run_lazyinit_thread();
4043 		if (ret)
4044 			goto out;
4045 	}
4046 out:
4047 	mutex_unlock(&ext4_li_mtx);
4048 	if (ret)
4049 		kfree(elr);
4050 	return ret;
4051 }
4052 
4053 /*
4054  * We do not need to lock anything since this is called on
4055  * module unload.
4056  */
4057 static void ext4_destroy_lazyinit_thread(void)
4058 {
4059 	/*
4060 	 * If thread exited earlier
4061 	 * there's nothing to be done.
4062 	 */
4063 	if (!ext4_li_info || !ext4_lazyinit_task)
4064 		return;
4065 
4066 	kthread_stop(ext4_lazyinit_task);
4067 }
4068 
4069 static int set_journal_csum_feature_set(struct super_block *sb)
4070 {
4071 	int ret = 1;
4072 	int compat, incompat;
4073 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4074 
4075 	if (ext4_has_feature_metadata_csum(sb)) {
4076 		/* journal checksum v3 */
4077 		compat = 0;
4078 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4079 	} else {
4080 		/* journal checksum v1 */
4081 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4082 		incompat = 0;
4083 	}
4084 
4085 	jbd2_journal_clear_features(sbi->s_journal,
4086 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4087 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4088 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4089 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4090 		ret = jbd2_journal_set_features(sbi->s_journal,
4091 				compat, 0,
4092 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4093 				incompat);
4094 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4095 		ret = jbd2_journal_set_features(sbi->s_journal,
4096 				compat, 0,
4097 				incompat);
4098 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4099 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4100 	} else {
4101 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4102 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4103 	}
4104 
4105 	return ret;
4106 }
4107 
4108 /*
4109  * Note: calculating the overhead so we can be compatible with
4110  * historical BSD practice is quite difficult in the face of
4111  * clusters/bigalloc.  This is because multiple metadata blocks from
4112  * different block group can end up in the same allocation cluster.
4113  * Calculating the exact overhead in the face of clustered allocation
4114  * requires either O(all block bitmaps) in memory or O(number of block
4115  * groups**2) in time.  We will still calculate the superblock for
4116  * older file systems --- and if we come across with a bigalloc file
4117  * system with zero in s_overhead_clusters the estimate will be close to
4118  * correct especially for very large cluster sizes --- but for newer
4119  * file systems, it's better to calculate this figure once at mkfs
4120  * time, and store it in the superblock.  If the superblock value is
4121  * present (even for non-bigalloc file systems), we will use it.
4122  */
4123 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4124 			  char *buf)
4125 {
4126 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4127 	struct ext4_group_desc	*gdp;
4128 	ext4_fsblk_t		first_block, last_block, b;
4129 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4130 	int			s, j, count = 0;
4131 	int			has_super = ext4_bg_has_super(sb, grp);
4132 
4133 	if (!ext4_has_feature_bigalloc(sb))
4134 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4135 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4136 			sbi->s_itb_per_group + 2);
4137 
4138 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4139 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4140 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4141 	for (i = 0; i < ngroups; i++) {
4142 		gdp = ext4_get_group_desc(sb, i, NULL);
4143 		b = ext4_block_bitmap(sb, gdp);
4144 		if (b >= first_block && b <= last_block) {
4145 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4146 			count++;
4147 		}
4148 		b = ext4_inode_bitmap(sb, gdp);
4149 		if (b >= first_block && b <= last_block) {
4150 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4151 			count++;
4152 		}
4153 		b = ext4_inode_table(sb, gdp);
4154 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4155 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4156 				int c = EXT4_B2C(sbi, b - first_block);
4157 				ext4_set_bit(c, buf);
4158 				count++;
4159 			}
4160 		if (i != grp)
4161 			continue;
4162 		s = 0;
4163 		if (ext4_bg_has_super(sb, grp)) {
4164 			ext4_set_bit(s++, buf);
4165 			count++;
4166 		}
4167 		j = ext4_bg_num_gdb(sb, grp);
4168 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4169 			ext4_error(sb, "Invalid number of block group "
4170 				   "descriptor blocks: %d", j);
4171 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4172 		}
4173 		count += j;
4174 		for (; j > 0; j--)
4175 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4176 	}
4177 	if (!count)
4178 		return 0;
4179 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4180 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4181 }
4182 
4183 /*
4184  * Compute the overhead and stash it in sbi->s_overhead
4185  */
4186 int ext4_calculate_overhead(struct super_block *sb)
4187 {
4188 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4189 	struct ext4_super_block *es = sbi->s_es;
4190 	struct inode *j_inode;
4191 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4192 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4193 	ext4_fsblk_t overhead = 0;
4194 	char *buf = kvmalloc(sb->s_blocksize, GFP_NOFS | __GFP_ZERO);
4195 
4196 	if (!buf)
4197 		return -ENOMEM;
4198 
4199 	/*
4200 	 * Compute the overhead (FS structures).  This is constant
4201 	 * for a given filesystem unless the number of block groups
4202 	 * changes so we cache the previous value until it does.
4203 	 */
4204 
4205 	/*
4206 	 * All of the blocks before first_data_block are overhead
4207 	 */
4208 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4209 
4210 	/*
4211 	 * Add the overhead found in each block group
4212 	 */
4213 	for (i = 0; i < ngroups; i++) {
4214 		int blks;
4215 
4216 		blks = count_overhead(sb, i, buf);
4217 		overhead += blks;
4218 		if (blks)
4219 			memset(buf, 0, sb->s_blocksize);
4220 		cond_resched();
4221 	}
4222 
4223 	/*
4224 	 * Add the internal journal blocks whether the journal has been
4225 	 * loaded or not
4226 	 */
4227 	if (sbi->s_journal && !sbi->s_journal_bdev_file)
4228 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4229 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4230 		/* j_inum for internal journal is non-zero */
4231 		j_inode = ext4_get_journal_inode(sb, j_inum);
4232 		if (!IS_ERR(j_inode)) {
4233 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4234 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4235 			iput(j_inode);
4236 		} else {
4237 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4238 		}
4239 	}
4240 	sbi->s_overhead = overhead;
4241 	smp_wmb();
4242 	kvfree(buf);
4243 	return 0;
4244 }
4245 
4246 static void ext4_set_resv_clusters(struct super_block *sb)
4247 {
4248 	ext4_fsblk_t resv_clusters;
4249 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4250 
4251 	/*
4252 	 * There's no need to reserve anything when we aren't using extents.
4253 	 * The space estimates are exact, there are no unwritten extents,
4254 	 * hole punching doesn't need new metadata... This is needed especially
4255 	 * to keep ext2/3 backward compatibility.
4256 	 */
4257 	if (!ext4_has_feature_extents(sb))
4258 		return;
4259 	/*
4260 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4261 	 * This should cover the situations where we can not afford to run
4262 	 * out of space like for example punch hole, or converting
4263 	 * unwritten extents in delalloc path. In most cases such
4264 	 * allocation would require 1, or 2 blocks, higher numbers are
4265 	 * very rare.
4266 	 */
4267 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4268 			 sbi->s_cluster_bits);
4269 
4270 	do_div(resv_clusters, 50);
4271 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4272 
4273 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4274 }
4275 
4276 static const char *ext4_quota_mode(struct super_block *sb)
4277 {
4278 #ifdef CONFIG_QUOTA
4279 	if (!ext4_quota_capable(sb))
4280 		return "none";
4281 
4282 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4283 		return "journalled";
4284 	else
4285 		return "writeback";
4286 #else
4287 	return "disabled";
4288 #endif
4289 }
4290 
4291 static void ext4_setup_csum_trigger(struct super_block *sb,
4292 				    enum ext4_journal_trigger_type type,
4293 				    void (*trigger)(
4294 					struct jbd2_buffer_trigger_type *type,
4295 					struct buffer_head *bh,
4296 					void *mapped_data,
4297 					size_t size))
4298 {
4299 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4300 
4301 	sbi->s_journal_triggers[type].sb = sb;
4302 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4303 }
4304 
4305 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4306 {
4307 	if (!sbi)
4308 		return;
4309 
4310 	kfree(sbi->s_blockgroup_lock);
4311 	fs_put_dax(sbi->s_daxdev, NULL);
4312 	kfree(sbi);
4313 }
4314 
4315 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4316 {
4317 	struct ext4_sb_info *sbi;
4318 
4319 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4320 	if (!sbi)
4321 		return NULL;
4322 
4323 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4324 					   NULL, NULL);
4325 
4326 	sbi->s_blockgroup_lock =
4327 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4328 
4329 	if (!sbi->s_blockgroup_lock)
4330 		goto err_out;
4331 
4332 	sb->s_fs_info = sbi;
4333 	sbi->s_sb = sb;
4334 	return sbi;
4335 err_out:
4336 	fs_put_dax(sbi->s_daxdev, NULL);
4337 	kfree(sbi);
4338 	return NULL;
4339 }
4340 
4341 static void ext4_set_def_opts(struct super_block *sb,
4342 			      struct ext4_super_block *es)
4343 {
4344 	unsigned long def_mount_opts;
4345 
4346 	/* Set defaults before we parse the mount options */
4347 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4348 	set_opt(sb, INIT_INODE_TABLE);
4349 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4350 		set_opt(sb, DEBUG);
4351 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4352 		set_opt(sb, GRPID);
4353 	if (def_mount_opts & EXT4_DEFM_UID16)
4354 		set_opt(sb, NO_UID32);
4355 	/* xattr user namespace & acls are now defaulted on */
4356 	set_opt(sb, XATTR_USER);
4357 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4358 	set_opt(sb, POSIX_ACL);
4359 #endif
4360 	if (ext4_has_feature_fast_commit(sb))
4361 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4362 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4363 	if (ext4_has_feature_metadata_csum(sb))
4364 		set_opt(sb, JOURNAL_CHECKSUM);
4365 
4366 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4367 		set_opt(sb, JOURNAL_DATA);
4368 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4369 		set_opt(sb, ORDERED_DATA);
4370 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4371 		set_opt(sb, WRITEBACK_DATA);
4372 
4373 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4374 		set_opt(sb, ERRORS_PANIC);
4375 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4376 		set_opt(sb, ERRORS_CONT);
4377 	else
4378 		set_opt(sb, ERRORS_RO);
4379 	/* block_validity enabled by default; disable with noblock_validity */
4380 	set_opt(sb, BLOCK_VALIDITY);
4381 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4382 		set_opt(sb, DISCARD);
4383 
4384 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4385 		set_opt(sb, BARRIER);
4386 
4387 	/*
4388 	 * enable delayed allocation by default
4389 	 * Use -o nodelalloc to turn it off
4390 	 */
4391 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4392 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4393 		set_opt(sb, DELALLOC);
4394 
4395 	set_opt(sb, DIOREAD_NOLOCK);
4396 }
4397 
4398 static int ext4_handle_clustersize(struct super_block *sb)
4399 {
4400 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4401 	struct ext4_super_block *es = sbi->s_es;
4402 	int clustersize;
4403 
4404 	/* Handle clustersize */
4405 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4406 	if (ext4_has_feature_bigalloc(sb)) {
4407 		if (clustersize < sb->s_blocksize) {
4408 			ext4_msg(sb, KERN_ERR,
4409 				 "cluster size (%d) smaller than "
4410 				 "block size (%lu)", clustersize, sb->s_blocksize);
4411 			return -EINVAL;
4412 		}
4413 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4414 			le32_to_cpu(es->s_log_block_size);
4415 	} else {
4416 		if (clustersize != sb->s_blocksize) {
4417 			ext4_msg(sb, KERN_ERR,
4418 				 "fragment/cluster size (%d) != "
4419 				 "block size (%lu)", clustersize, sb->s_blocksize);
4420 			return -EINVAL;
4421 		}
4422 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4423 			ext4_msg(sb, KERN_ERR,
4424 				 "#blocks per group too big: %lu",
4425 				 sbi->s_blocks_per_group);
4426 			return -EINVAL;
4427 		}
4428 		sbi->s_cluster_bits = 0;
4429 	}
4430 	sbi->s_clusters_per_group = le32_to_cpu(es->s_clusters_per_group);
4431 	if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4432 		ext4_msg(sb, KERN_ERR, "#clusters per group too big: %lu",
4433 			 sbi->s_clusters_per_group);
4434 		return -EINVAL;
4435 	}
4436 	if (sbi->s_blocks_per_group !=
4437 	    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4438 		ext4_msg(sb, KERN_ERR,
4439 			 "blocks per group (%lu) and clusters per group (%lu) inconsistent",
4440 			 sbi->s_blocks_per_group, sbi->s_clusters_per_group);
4441 		return -EINVAL;
4442 	}
4443 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4444 
4445 	/* Do we have standard group size of clustersize * 8 blocks ? */
4446 	if (sbi->s_blocks_per_group == clustersize << 3)
4447 		set_opt2(sb, STD_GROUP_SIZE);
4448 
4449 	return 0;
4450 }
4451 
4452 /*
4453  * ext4_atomic_write_init: Initializes filesystem min & max atomic write units.
4454  * With non-bigalloc filesystem awu will be based upon filesystem blocksize
4455  * & bdev awu units.
4456  * With bigalloc it will be based upon bigalloc cluster size & bdev awu units.
4457  * @sb: super block
4458  */
4459 static void ext4_atomic_write_init(struct super_block *sb)
4460 {
4461 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4462 	struct block_device *bdev = sb->s_bdev;
4463 	unsigned int clustersize = EXT4_CLUSTER_SIZE(sb);
4464 
4465 	if (!bdev_can_atomic_write(bdev))
4466 		return;
4467 
4468 	if (!ext4_has_feature_extents(sb))
4469 		return;
4470 
4471 	sbi->s_awu_min = max(sb->s_blocksize,
4472 			      bdev_atomic_write_unit_min_bytes(bdev));
4473 	sbi->s_awu_max = min(clustersize,
4474 			      bdev_atomic_write_unit_max_bytes(bdev));
4475 	if (sbi->s_awu_min && sbi->s_awu_max &&
4476 	    sbi->s_awu_min <= sbi->s_awu_max) {
4477 		ext4_msg(sb, KERN_NOTICE, "Supports (experimental) DIO atomic writes awu_min: %u, awu_max: %u",
4478 			 sbi->s_awu_min, sbi->s_awu_max);
4479 	} else {
4480 		sbi->s_awu_min = 0;
4481 		sbi->s_awu_max = 0;
4482 	}
4483 }
4484 
4485 static void ext4_fast_commit_init(struct super_block *sb)
4486 {
4487 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4488 
4489 	/* Initialize fast commit stuff */
4490 	atomic_set(&sbi->s_fc_subtid, 0);
4491 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4492 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4493 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4494 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4495 	sbi->s_fc_bytes = 0;
4496 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4497 	sbi->s_fc_ineligible_tid = 0;
4498 	mutex_init(&sbi->s_fc_lock);
4499 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4500 	sbi->s_fc_replay_state.fc_regions = NULL;
4501 	sbi->s_fc_replay_state.fc_regions_size = 0;
4502 	sbi->s_fc_replay_state.fc_regions_used = 0;
4503 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4504 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4505 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4506 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4507 }
4508 
4509 static int ext4_inode_info_init(struct super_block *sb,
4510 				struct ext4_super_block *es)
4511 {
4512 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4513 
4514 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4515 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4516 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4517 	} else {
4518 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4519 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4520 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4521 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4522 				 sbi->s_first_ino);
4523 			return -EINVAL;
4524 		}
4525 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4526 		    (!is_power_of_2(sbi->s_inode_size)) ||
4527 		    (sbi->s_inode_size > sb->s_blocksize)) {
4528 			ext4_msg(sb, KERN_ERR,
4529 			       "unsupported inode size: %d",
4530 			       sbi->s_inode_size);
4531 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4532 			return -EINVAL;
4533 		}
4534 		/*
4535 		 * i_atime_extra is the last extra field available for
4536 		 * [acm]times in struct ext4_inode. Checking for that
4537 		 * field should suffice to ensure we have extra space
4538 		 * for all three.
4539 		 */
4540 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4541 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4542 			sb->s_time_gran = 1;
4543 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4544 		} else {
4545 			sb->s_time_gran = NSEC_PER_SEC;
4546 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4547 		}
4548 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4549 	}
4550 
4551 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4552 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4553 			EXT4_GOOD_OLD_INODE_SIZE;
4554 		if (ext4_has_feature_extra_isize(sb)) {
4555 			unsigned v, max = (sbi->s_inode_size -
4556 					   EXT4_GOOD_OLD_INODE_SIZE);
4557 
4558 			v = le16_to_cpu(es->s_want_extra_isize);
4559 			if (v > max) {
4560 				ext4_msg(sb, KERN_ERR,
4561 					 "bad s_want_extra_isize: %d", v);
4562 				return -EINVAL;
4563 			}
4564 			if (sbi->s_want_extra_isize < v)
4565 				sbi->s_want_extra_isize = v;
4566 
4567 			v = le16_to_cpu(es->s_min_extra_isize);
4568 			if (v > max) {
4569 				ext4_msg(sb, KERN_ERR,
4570 					 "bad s_min_extra_isize: %d", v);
4571 				return -EINVAL;
4572 			}
4573 			if (sbi->s_want_extra_isize < v)
4574 				sbi->s_want_extra_isize = v;
4575 		}
4576 	}
4577 
4578 	return 0;
4579 }
4580 
4581 #if IS_ENABLED(CONFIG_UNICODE)
4582 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4583 {
4584 	const struct ext4_sb_encodings *encoding_info;
4585 	struct unicode_map *encoding;
4586 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4587 
4588 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4589 		return 0;
4590 
4591 	encoding_info = ext4_sb_read_encoding(es);
4592 	if (!encoding_info) {
4593 		ext4_msg(sb, KERN_ERR,
4594 			"Encoding requested by superblock is unknown");
4595 		return -EINVAL;
4596 	}
4597 
4598 	encoding = utf8_load(encoding_info->version);
4599 	if (IS_ERR(encoding)) {
4600 		ext4_msg(sb, KERN_ERR,
4601 			"can't mount with superblock charset: %s-%u.%u.%u "
4602 			"not supported by the kernel. flags: 0x%x.",
4603 			encoding_info->name,
4604 			unicode_major(encoding_info->version),
4605 			unicode_minor(encoding_info->version),
4606 			unicode_rev(encoding_info->version),
4607 			encoding_flags);
4608 		return -EINVAL;
4609 	}
4610 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4611 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4612 		unicode_major(encoding_info->version),
4613 		unicode_minor(encoding_info->version),
4614 		unicode_rev(encoding_info->version),
4615 		encoding_flags);
4616 
4617 	sb->s_encoding = encoding;
4618 	sb->s_encoding_flags = encoding_flags;
4619 
4620 	return 0;
4621 }
4622 #else
4623 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4624 {
4625 	return 0;
4626 }
4627 #endif
4628 
4629 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4630 {
4631 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4632 
4633 	/* Warn if metadata_csum and gdt_csum are both set. */
4634 	if (ext4_has_feature_metadata_csum(sb) &&
4635 	    ext4_has_feature_gdt_csum(sb))
4636 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4637 			     "redundant flags; please run fsck.");
4638 
4639 	/* Check for a known checksum algorithm */
4640 	if (!ext4_verify_csum_type(sb, es)) {
4641 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4642 			 "unknown checksum algorithm.");
4643 		return -EINVAL;
4644 	}
4645 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4646 				ext4_orphan_file_block_trigger);
4647 
4648 	/* Check superblock checksum */
4649 	if (!ext4_superblock_csum_verify(sb, es)) {
4650 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4651 			 "invalid superblock checksum.  Run e2fsck?");
4652 		return -EFSBADCRC;
4653 	}
4654 
4655 	/* Precompute checksum seed for all metadata */
4656 	if (ext4_has_feature_csum_seed(sb))
4657 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4658 	else if (ext4_has_feature_metadata_csum(sb) ||
4659 		 ext4_has_feature_ea_inode(sb))
4660 		sbi->s_csum_seed = ext4_chksum(~0, es->s_uuid,
4661 					       sizeof(es->s_uuid));
4662 	return 0;
4663 }
4664 
4665 static int ext4_check_feature_compatibility(struct super_block *sb,
4666 					    struct ext4_super_block *es,
4667 					    int silent)
4668 {
4669 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4670 
4671 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4672 	    (ext4_has_compat_features(sb) ||
4673 	     ext4_has_ro_compat_features(sb) ||
4674 	     ext4_has_incompat_features(sb)))
4675 		ext4_msg(sb, KERN_WARNING,
4676 		       "feature flags set on rev 0 fs, "
4677 		       "running e2fsck is recommended");
4678 
4679 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4680 		set_opt2(sb, HURD_COMPAT);
4681 		if (ext4_has_feature_64bit(sb)) {
4682 			ext4_msg(sb, KERN_ERR,
4683 				 "The Hurd can't support 64-bit file systems");
4684 			return -EINVAL;
4685 		}
4686 
4687 		/*
4688 		 * ea_inode feature uses l_i_version field which is not
4689 		 * available in HURD_COMPAT mode.
4690 		 */
4691 		if (ext4_has_feature_ea_inode(sb)) {
4692 			ext4_msg(sb, KERN_ERR,
4693 				 "ea_inode feature is not supported for Hurd");
4694 			return -EINVAL;
4695 		}
4696 	}
4697 
4698 	if (IS_EXT2_SB(sb)) {
4699 		if (ext2_feature_set_ok(sb))
4700 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4701 				 "using the ext4 subsystem");
4702 		else {
4703 			/*
4704 			 * If we're probing be silent, if this looks like
4705 			 * it's actually an ext[34] filesystem.
4706 			 */
4707 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4708 				return -EINVAL;
4709 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4710 				 "to feature incompatibilities");
4711 			return -EINVAL;
4712 		}
4713 	}
4714 
4715 	if (IS_EXT3_SB(sb)) {
4716 		if (ext3_feature_set_ok(sb))
4717 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4718 				 "using the ext4 subsystem");
4719 		else {
4720 			/*
4721 			 * If we're probing be silent, if this looks like
4722 			 * it's actually an ext4 filesystem.
4723 			 */
4724 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4725 				return -EINVAL;
4726 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4727 				 "to feature incompatibilities");
4728 			return -EINVAL;
4729 		}
4730 	}
4731 
4732 	/*
4733 	 * Check feature flags regardless of the revision level, since we
4734 	 * previously didn't change the revision level when setting the flags,
4735 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4736 	 */
4737 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4738 		return -EINVAL;
4739 
4740 	if (sbi->s_daxdev) {
4741 		if (sb->s_blocksize == PAGE_SIZE)
4742 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4743 		else
4744 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4745 	}
4746 
4747 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4748 		if (ext4_has_feature_inline_data(sb)) {
4749 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4750 					" that may contain inline data");
4751 			return -EINVAL;
4752 		}
4753 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4754 			ext4_msg(sb, KERN_ERR,
4755 				"DAX unsupported by block device.");
4756 			return -EINVAL;
4757 		}
4758 	}
4759 
4760 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4761 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4762 			 es->s_encryption_level);
4763 		return -EINVAL;
4764 	}
4765 
4766 	return 0;
4767 }
4768 
4769 static int ext4_check_geometry(struct super_block *sb,
4770 			       struct ext4_super_block *es)
4771 {
4772 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4773 	__u64 blocks_count;
4774 	int err;
4775 
4776 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4777 		ext4_msg(sb, KERN_ERR,
4778 			 "Number of reserved GDT blocks insanely large: %d",
4779 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4780 		return -EINVAL;
4781 	}
4782 	/*
4783 	 * Test whether we have more sectors than will fit in sector_t,
4784 	 * and whether the max offset is addressable by the page cache.
4785 	 */
4786 	err = generic_check_addressable(sb->s_blocksize_bits,
4787 					ext4_blocks_count(es));
4788 	if (err) {
4789 		ext4_msg(sb, KERN_ERR, "filesystem"
4790 			 " too large to mount safely on this system");
4791 		return err;
4792 	}
4793 
4794 	/* check blocks count against device size */
4795 	blocks_count = sb_bdev_nr_blocks(sb);
4796 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4797 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4798 		       "exceeds size of device (%llu blocks)",
4799 		       ext4_blocks_count(es), blocks_count);
4800 		return -EINVAL;
4801 	}
4802 
4803 	/*
4804 	 * It makes no sense for the first data block to be beyond the end
4805 	 * of the filesystem.
4806 	 */
4807 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4808 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4809 			 "block %u is beyond end of filesystem (%llu)",
4810 			 le32_to_cpu(es->s_first_data_block),
4811 			 ext4_blocks_count(es));
4812 		return -EINVAL;
4813 	}
4814 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4815 	    (sbi->s_cluster_ratio == 1)) {
4816 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4817 			 "block is 0 with a 1k block and cluster size");
4818 		return -EINVAL;
4819 	}
4820 
4821 	blocks_count = (ext4_blocks_count(es) -
4822 			le32_to_cpu(es->s_first_data_block) +
4823 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4824 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4825 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4826 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4827 		       "(block count %llu, first data block %u, "
4828 		       "blocks per group %lu)", blocks_count,
4829 		       ext4_blocks_count(es),
4830 		       le32_to_cpu(es->s_first_data_block),
4831 		       EXT4_BLOCKS_PER_GROUP(sb));
4832 		return -EINVAL;
4833 	}
4834 	sbi->s_groups_count = blocks_count;
4835 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4836 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4837 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4838 	    le32_to_cpu(es->s_inodes_count)) {
4839 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4840 			 le32_to_cpu(es->s_inodes_count),
4841 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4842 		return -EINVAL;
4843 	}
4844 
4845 	return 0;
4846 }
4847 
4848 static int ext4_group_desc_init(struct super_block *sb,
4849 				struct ext4_super_block *es,
4850 				ext4_fsblk_t logical_sb_block,
4851 				ext4_group_t *first_not_zeroed)
4852 {
4853 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4854 	unsigned int db_count;
4855 	ext4_fsblk_t block;
4856 	int i;
4857 
4858 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4859 		   EXT4_DESC_PER_BLOCK(sb);
4860 	if (ext4_has_feature_meta_bg(sb)) {
4861 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4862 			ext4_msg(sb, KERN_WARNING,
4863 				 "first meta block group too large: %u "
4864 				 "(group descriptor block count %u)",
4865 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4866 			return -EINVAL;
4867 		}
4868 	}
4869 	rcu_assign_pointer(sbi->s_group_desc,
4870 			   kvmalloc_array(db_count,
4871 					  sizeof(struct buffer_head *),
4872 					  GFP_KERNEL));
4873 	if (sbi->s_group_desc == NULL) {
4874 		ext4_msg(sb, KERN_ERR, "not enough memory");
4875 		return -ENOMEM;
4876 	}
4877 
4878 	bgl_lock_init(sbi->s_blockgroup_lock);
4879 
4880 	/* Pre-read the descriptors into the buffer cache */
4881 	for (i = 0; i < db_count; i++) {
4882 		block = descriptor_loc(sb, logical_sb_block, i);
4883 		ext4_sb_breadahead_unmovable(sb, block);
4884 	}
4885 
4886 	for (i = 0; i < db_count; i++) {
4887 		struct buffer_head *bh;
4888 
4889 		block = descriptor_loc(sb, logical_sb_block, i);
4890 		bh = ext4_sb_bread_unmovable(sb, block);
4891 		if (IS_ERR(bh)) {
4892 			ext4_msg(sb, KERN_ERR,
4893 			       "can't read group descriptor %d", i);
4894 			sbi->s_gdb_count = i;
4895 			return PTR_ERR(bh);
4896 		}
4897 		rcu_read_lock();
4898 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4899 		rcu_read_unlock();
4900 	}
4901 	sbi->s_gdb_count = db_count;
4902 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4903 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4904 		return -EFSCORRUPTED;
4905 	}
4906 
4907 	return 0;
4908 }
4909 
4910 static int ext4_load_and_init_journal(struct super_block *sb,
4911 				      struct ext4_super_block *es,
4912 				      struct ext4_fs_context *ctx)
4913 {
4914 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4915 	int err;
4916 
4917 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4918 	if (err)
4919 		return err;
4920 
4921 	if (ext4_has_feature_64bit(sb) &&
4922 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4923 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4924 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4925 		goto out;
4926 	}
4927 
4928 	if (!set_journal_csum_feature_set(sb)) {
4929 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4930 			 "feature set");
4931 		goto out;
4932 	}
4933 
4934 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4935 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4936 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4937 		ext4_msg(sb, KERN_ERR,
4938 			"Failed to set fast commit journal feature");
4939 		goto out;
4940 	}
4941 
4942 	/* We have now updated the journal if required, so we can
4943 	 * validate the data journaling mode. */
4944 	switch (test_opt(sb, DATA_FLAGS)) {
4945 	case 0:
4946 		/* No mode set, assume a default based on the journal
4947 		 * capabilities: ORDERED_DATA if the journal can
4948 		 * cope, else JOURNAL_DATA
4949 		 */
4950 		if (jbd2_journal_check_available_features
4951 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4952 			set_opt(sb, ORDERED_DATA);
4953 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4954 		} else {
4955 			set_opt(sb, JOURNAL_DATA);
4956 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4957 		}
4958 		break;
4959 
4960 	case EXT4_MOUNT_ORDERED_DATA:
4961 	case EXT4_MOUNT_WRITEBACK_DATA:
4962 		if (!jbd2_journal_check_available_features
4963 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4964 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4965 			       "requested data journaling mode");
4966 			goto out;
4967 		}
4968 		break;
4969 	default:
4970 		break;
4971 	}
4972 
4973 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4974 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4975 		ext4_msg(sb, KERN_ERR, "can't mount with "
4976 			"journal_async_commit in data=ordered mode");
4977 		goto out;
4978 	}
4979 
4980 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4981 
4982 	sbi->s_journal->j_submit_inode_data_buffers =
4983 		ext4_journal_submit_inode_data_buffers;
4984 	sbi->s_journal->j_finish_inode_data_buffers =
4985 		ext4_journal_finish_inode_data_buffers;
4986 
4987 	return 0;
4988 
4989 out:
4990 	ext4_journal_destroy(sbi, sbi->s_journal);
4991 	return -EINVAL;
4992 }
4993 
4994 static int ext4_check_journal_data_mode(struct super_block *sb)
4995 {
4996 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4997 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4998 			    "data=journal disables delayed allocation, "
4999 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
5000 		/* can't mount with both data=journal and dioread_nolock. */
5001 		clear_opt(sb, DIOREAD_NOLOCK);
5002 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5003 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5004 			ext4_msg(sb, KERN_ERR, "can't mount with "
5005 				 "both data=journal and delalloc");
5006 			return -EINVAL;
5007 		}
5008 		if (test_opt(sb, DAX_ALWAYS)) {
5009 			ext4_msg(sb, KERN_ERR, "can't mount with "
5010 				 "both data=journal and dax");
5011 			return -EINVAL;
5012 		}
5013 		if (ext4_has_feature_encrypt(sb)) {
5014 			ext4_msg(sb, KERN_WARNING,
5015 				 "encrypted files will use data=ordered "
5016 				 "instead of data journaling mode");
5017 		}
5018 		if (test_opt(sb, DELALLOC))
5019 			clear_opt(sb, DELALLOC);
5020 	} else {
5021 		sb->s_iflags |= SB_I_CGROUPWB;
5022 	}
5023 
5024 	return 0;
5025 }
5026 
5027 static const char *ext4_has_journal_option(struct super_block *sb)
5028 {
5029 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5030 
5031 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
5032 		return "journal_async_commit";
5033 	if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM))
5034 		return "journal_checksum";
5035 	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
5036 		return "commit=";
5037 	if (EXT4_MOUNT_DATA_FLAGS &
5038 	    (sbi->s_mount_opt ^ sbi->s_def_mount_opt))
5039 		return "data=";
5040 	if (test_opt(sb, DATA_ERR_ABORT))
5041 		return "data_err=abort";
5042 	return NULL;
5043 }
5044 
5045 /*
5046  * Limit the maximum folio order to 2048 blocks to prevent overestimation
5047  * of reserve handle credits during the folio writeback in environments
5048  * where the PAGE_SIZE exceeds 4KB.
5049  */
5050 #define EXT4_MAX_PAGECACHE_ORDER(sb)		\
5051 		umin(MAX_PAGECACHE_ORDER, (11 + (sb)->s_blocksize_bits - PAGE_SHIFT))
5052 static void ext4_set_max_mapping_order(struct super_block *sb)
5053 {
5054 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5055 
5056 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5057 		sbi->s_max_folio_order = sbi->s_min_folio_order;
5058 	else
5059 		sbi->s_max_folio_order = EXT4_MAX_PAGECACHE_ORDER(sb);
5060 }
5061 
5062 static int ext4_check_large_folio(struct super_block *sb)
5063 {
5064 	const char *err_str = NULL;
5065 
5066 	if (ext4_has_feature_encrypt(sb))
5067 		err_str = "encrypt";
5068 
5069 	if (!err_str) {
5070 		ext4_set_max_mapping_order(sb);
5071 	} else if (sb->s_blocksize > PAGE_SIZE) {
5072 		ext4_msg(sb, KERN_ERR, "bs(%lu) > ps(%lu) unsupported for %s",
5073 			 sb->s_blocksize, PAGE_SIZE, err_str);
5074 		return -EINVAL;
5075 	}
5076 
5077 	return 0;
5078 }
5079 
5080 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5081 			   int silent)
5082 {
5083 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5084 	struct ext4_super_block *es;
5085 	ext4_fsblk_t logical_sb_block;
5086 	unsigned long offset = 0;
5087 	struct buffer_head *bh;
5088 	int ret = -EINVAL;
5089 	int blocksize;
5090 
5091 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5092 	if (!blocksize) {
5093 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5094 		return -EINVAL;
5095 	}
5096 
5097 	/*
5098 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5099 	 * block sizes.  We need to calculate the offset from buffer start.
5100 	 */
5101 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5102 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5103 		offset = do_div(logical_sb_block, blocksize);
5104 	} else {
5105 		logical_sb_block = sbi->s_sb_block;
5106 	}
5107 
5108 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5109 	if (IS_ERR(bh)) {
5110 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5111 		return PTR_ERR(bh);
5112 	}
5113 	/*
5114 	 * Note: s_es must be initialized as soon as possible because
5115 	 *       some ext4 macro-instructions depend on its value
5116 	 */
5117 	es = (struct ext4_super_block *) (bh->b_data + offset);
5118 	sbi->s_es = es;
5119 	sb->s_magic = le16_to_cpu(es->s_magic);
5120 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5121 		if (!silent)
5122 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5123 		goto out;
5124 	}
5125 
5126 	if (le32_to_cpu(es->s_log_block_size) >
5127 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5128 		ext4_msg(sb, KERN_ERR,
5129 			 "Invalid log block size: %u",
5130 			 le32_to_cpu(es->s_log_block_size));
5131 		goto out;
5132 	}
5133 	if (le32_to_cpu(es->s_log_cluster_size) >
5134 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5135 		ext4_msg(sb, KERN_ERR,
5136 			 "Invalid log cluster size: %u",
5137 			 le32_to_cpu(es->s_log_cluster_size));
5138 		goto out;
5139 	}
5140 
5141 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5142 
5143 	/*
5144 	 * If the default block size is not the same as the real block size,
5145 	 * we need to reload it.
5146 	 */
5147 	if (sb->s_blocksize == blocksize)
5148 		goto success;
5149 
5150 	/*
5151 	 * bh must be released before kill_bdev(), otherwise
5152 	 * it won't be freed and its page also. kill_bdev()
5153 	 * is called by sb_set_blocksize().
5154 	 */
5155 	brelse(bh);
5156 	/* Validate the filesystem blocksize */
5157 	if (!sb_set_blocksize(sb, blocksize)) {
5158 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5159 				blocksize);
5160 		bh = NULL;
5161 		goto out;
5162 	}
5163 
5164 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5165 	offset = do_div(logical_sb_block, blocksize);
5166 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5167 	if (IS_ERR(bh)) {
5168 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5169 		ret = PTR_ERR(bh);
5170 		bh = NULL;
5171 		goto out;
5172 	}
5173 	es = (struct ext4_super_block *)(bh->b_data + offset);
5174 	sbi->s_es = es;
5175 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5176 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5177 		goto out;
5178 	}
5179 
5180 success:
5181 	sbi->s_min_folio_order = get_order(blocksize);
5182 	*lsb = logical_sb_block;
5183 	sbi->s_sbh = bh;
5184 	return 0;
5185 out:
5186 	brelse(bh);
5187 	return ret;
5188 }
5189 
5190 static int ext4_hash_info_init(struct super_block *sb)
5191 {
5192 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5193 	struct ext4_super_block *es = sbi->s_es;
5194 	unsigned int i;
5195 
5196 	sbi->s_def_hash_version = es->s_def_hash_version;
5197 
5198 	if (sbi->s_def_hash_version > DX_HASH_LAST) {
5199 		ext4_msg(sb, KERN_ERR,
5200 			 "Invalid default hash set in the superblock");
5201 		return -EINVAL;
5202 	} else if (sbi->s_def_hash_version == DX_HASH_SIPHASH) {
5203 		ext4_msg(sb, KERN_ERR,
5204 			 "SIPHASH is not a valid default hash value");
5205 		return -EINVAL;
5206 	}
5207 
5208 	for (i = 0; i < 4; i++)
5209 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5210 
5211 	if (ext4_has_feature_dir_index(sb)) {
5212 		i = le32_to_cpu(es->s_flags);
5213 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5214 			sbi->s_hash_unsigned = 3;
5215 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5216 #ifdef __CHAR_UNSIGNED__
5217 			if (!sb_rdonly(sb))
5218 				es->s_flags |=
5219 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5220 			sbi->s_hash_unsigned = 3;
5221 #else
5222 			if (!sb_rdonly(sb))
5223 				es->s_flags |=
5224 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5225 #endif
5226 		}
5227 	}
5228 	return 0;
5229 }
5230 
5231 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5232 {
5233 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5234 	struct ext4_super_block *es = sbi->s_es;
5235 	int has_huge_files;
5236 
5237 	has_huge_files = ext4_has_feature_huge_file(sb);
5238 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5239 						      has_huge_files);
5240 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5241 
5242 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5243 	if (ext4_has_feature_64bit(sb)) {
5244 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5245 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5246 		    !is_power_of_2(sbi->s_desc_size)) {
5247 			ext4_msg(sb, KERN_ERR,
5248 			       "unsupported descriptor size %lu",
5249 			       sbi->s_desc_size);
5250 			return -EINVAL;
5251 		}
5252 	} else
5253 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5254 
5255 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5256 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5257 
5258 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5259 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5260 		if (!silent)
5261 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5262 		return -EINVAL;
5263 	}
5264 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5265 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5266 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5267 			 sbi->s_inodes_per_group);
5268 		return -EINVAL;
5269 	}
5270 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5271 					sbi->s_inodes_per_block;
5272 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5273 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5274 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5275 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5276 
5277 	return 0;
5278 }
5279 
5280 /*
5281  * It's hard to get stripe aligned blocks if stripe is not aligned with
5282  * cluster, just disable stripe and alert user to simplify code and avoid
5283  * stripe aligned allocation which will rarely succeed.
5284  */
5285 static bool ext4_is_stripe_incompatible(struct super_block *sb, unsigned long stripe)
5286 {
5287 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5288 	return (stripe > 0 && sbi->s_cluster_ratio > 1 &&
5289 		stripe % sbi->s_cluster_ratio != 0);
5290 }
5291 
5292 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5293 {
5294 	struct ext4_super_block *es = NULL;
5295 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5296 	ext4_fsblk_t logical_sb_block;
5297 	struct inode *root;
5298 	int needs_recovery;
5299 	int err;
5300 	ext4_group_t first_not_zeroed;
5301 	struct ext4_fs_context *ctx = fc->fs_private;
5302 	int silent = fc->sb_flags & SB_SILENT;
5303 
5304 	/* Set defaults for the variables that will be set during parsing */
5305 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5306 		ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
5307 
5308 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5309 	sbi->s_sectors_written_start =
5310 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5311 
5312 	err = ext4_load_super(sb, &logical_sb_block, silent);
5313 	if (err)
5314 		goto out_fail;
5315 
5316 	es = sbi->s_es;
5317 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5318 
5319 	err = ext4_init_metadata_csum(sb, es);
5320 	if (err)
5321 		goto failed_mount;
5322 
5323 	ext4_set_def_opts(sb, es);
5324 
5325 	sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
5326 	sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
5327 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5328 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5329 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5330 	sbi->s_sb_update_kb = EXT4_DEF_SB_UPDATE_INTERVAL_KB;
5331 	sbi->s_sb_update_sec = EXT4_DEF_SB_UPDATE_INTERVAL_SEC;
5332 
5333 	/*
5334 	 * set default s_li_wait_mult for lazyinit, for the case there is
5335 	 * no mount option specified.
5336 	 */
5337 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5338 
5339 	err = ext4_inode_info_init(sb, es);
5340 	if (err)
5341 		goto failed_mount;
5342 
5343 	err = parse_apply_sb_mount_options(sb, ctx);
5344 	if (err < 0)
5345 		goto failed_mount;
5346 
5347 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5348 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5349 
5350 	err = ext4_check_opt_consistency(fc, sb);
5351 	if (err < 0)
5352 		goto failed_mount;
5353 
5354 	ext4_apply_options(fc, sb);
5355 
5356 	err = ext4_check_large_folio(sb);
5357 	if (err < 0)
5358 		goto failed_mount;
5359 
5360 	err = ext4_encoding_init(sb, es);
5361 	if (err)
5362 		goto failed_mount;
5363 
5364 	err = ext4_check_journal_data_mode(sb);
5365 	if (err)
5366 		goto failed_mount;
5367 
5368 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5369 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5370 
5371 	/* HSM events are allowed by default. */
5372 	sb->s_iflags |= SB_I_ALLOW_HSM;
5373 
5374 	err = ext4_check_feature_compatibility(sb, es, silent);
5375 	if (err)
5376 		goto failed_mount;
5377 
5378 	err = ext4_block_group_meta_init(sb, silent);
5379 	if (err)
5380 		goto failed_mount;
5381 
5382 	err = ext4_hash_info_init(sb);
5383 	if (err)
5384 		goto failed_mount;
5385 
5386 	err = ext4_handle_clustersize(sb);
5387 	if (err)
5388 		goto failed_mount;
5389 
5390 	err = ext4_check_geometry(sb, es);
5391 	if (err)
5392 		goto failed_mount;
5393 
5394 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5395 	spin_lock_init(&sbi->s_error_lock);
5396 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5397 
5398 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5399 	if (err)
5400 		goto failed_mount3;
5401 
5402 	err = ext4_es_register_shrinker(sbi);
5403 	if (err)
5404 		goto failed_mount3;
5405 
5406 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5407 	if (ext4_is_stripe_incompatible(sb, sbi->s_stripe)) {
5408 		ext4_msg(sb, KERN_WARNING,
5409 			 "stripe (%lu) is not aligned with cluster size (%u), "
5410 			 "stripe is disabled",
5411 			 sbi->s_stripe, sbi->s_cluster_ratio);
5412 		sbi->s_stripe = 0;
5413 	}
5414 	sbi->s_extent_max_zeroout_kb = 32;
5415 
5416 	/*
5417 	 * set up enough so that it can read an inode
5418 	 */
5419 	sb->s_op = &ext4_sops;
5420 	sb->s_export_op = &ext4_export_ops;
5421 	sb->s_xattr = ext4_xattr_handlers;
5422 #ifdef CONFIG_FS_ENCRYPTION
5423 	sb->s_cop = &ext4_cryptops;
5424 #endif
5425 #ifdef CONFIG_FS_VERITY
5426 	sb->s_vop = &ext4_verityops;
5427 #endif
5428 #ifdef CONFIG_QUOTA
5429 	sb->dq_op = &ext4_quota_operations;
5430 	if (ext4_has_feature_quota(sb))
5431 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5432 	else
5433 		sb->s_qcop = &ext4_qctl_operations;
5434 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5435 #endif
5436 	super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));
5437 	super_set_sysfs_name_bdev(sb);
5438 
5439 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5440 	mutex_init(&sbi->s_orphan_lock);
5441 
5442 	spin_lock_init(&sbi->s_bdev_wb_lock);
5443 
5444 	ext4_atomic_write_init(sb);
5445 	ext4_fast_commit_init(sb);
5446 
5447 	sb->s_root = NULL;
5448 
5449 	needs_recovery = (es->s_last_orphan != 0 ||
5450 			  ext4_has_feature_orphan_present(sb) ||
5451 			  ext4_has_feature_journal_needs_recovery(sb));
5452 
5453 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5454 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5455 		if (err)
5456 			goto failed_mount3a;
5457 	}
5458 
5459 	err = -EINVAL;
5460 	/*
5461 	 * The first inode we look at is the journal inode.  Don't try
5462 	 * root first: it may be modified in the journal!
5463 	 */
5464 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5465 		err = ext4_load_and_init_journal(sb, es, ctx);
5466 		if (err)
5467 			goto failed_mount3a;
5468 		if (bdev_read_only(sb->s_bdev))
5469 		    needs_recovery = 0;
5470 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5471 		   ext4_has_feature_journal_needs_recovery(sb)) {
5472 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5473 		       "suppressed and not mounted read-only");
5474 		goto failed_mount3a;
5475 	} else {
5476 		const char *journal_option;
5477 
5478 		/* Nojournal mode, all journal mount options are illegal */
5479 		journal_option = ext4_has_journal_option(sb);
5480 		if (journal_option != NULL) {
5481 			ext4_msg(sb, KERN_ERR,
5482 				 "can't mount with %s, fs mounted w/o journal",
5483 				 journal_option);
5484 			goto failed_mount3a;
5485 		}
5486 
5487 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5488 		clear_opt(sb, JOURNAL_CHECKSUM);
5489 		clear_opt(sb, DATA_FLAGS);
5490 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5491 		sbi->s_journal = NULL;
5492 		needs_recovery = 0;
5493 	}
5494 
5495 	if (!test_opt(sb, NO_MBCACHE)) {
5496 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5497 		if (!sbi->s_ea_block_cache) {
5498 			ext4_msg(sb, KERN_ERR,
5499 				 "Failed to create ea_block_cache");
5500 			err = -EINVAL;
5501 			goto failed_mount_wq;
5502 		}
5503 
5504 		if (ext4_has_feature_ea_inode(sb)) {
5505 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5506 			if (!sbi->s_ea_inode_cache) {
5507 				ext4_msg(sb, KERN_ERR,
5508 					 "Failed to create ea_inode_cache");
5509 				err = -EINVAL;
5510 				goto failed_mount_wq;
5511 			}
5512 		}
5513 	}
5514 
5515 	/*
5516 	 * Get the # of file system overhead blocks from the
5517 	 * superblock if present.
5518 	 */
5519 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5520 	/* ignore the precalculated value if it is ridiculous */
5521 	if (sbi->s_overhead > ext4_blocks_count(es))
5522 		sbi->s_overhead = 0;
5523 	/*
5524 	 * If the bigalloc feature is not enabled recalculating the
5525 	 * overhead doesn't take long, so we might as well just redo
5526 	 * it to make sure we are using the correct value.
5527 	 */
5528 	if (!ext4_has_feature_bigalloc(sb))
5529 		sbi->s_overhead = 0;
5530 	if (sbi->s_overhead == 0) {
5531 		err = ext4_calculate_overhead(sb);
5532 		if (err)
5533 			goto failed_mount_wq;
5534 	}
5535 
5536 	/*
5537 	 * The maximum number of concurrent works can be high and
5538 	 * concurrency isn't really necessary.  Limit it to 1.
5539 	 */
5540 	EXT4_SB(sb)->rsv_conversion_wq =
5541 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5542 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5543 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5544 		err = -ENOMEM;
5545 		goto failed_mount4;
5546 	}
5547 
5548 	/*
5549 	 * The jbd2_journal_load will have done any necessary log recovery,
5550 	 * so we can safely mount the rest of the filesystem now.
5551 	 */
5552 
5553 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5554 	if (IS_ERR(root)) {
5555 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5556 		err = PTR_ERR(root);
5557 		root = NULL;
5558 		goto failed_mount4;
5559 	}
5560 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5561 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5562 		iput(root);
5563 		err = -EFSCORRUPTED;
5564 		goto failed_mount4;
5565 	}
5566 
5567 	generic_set_sb_d_ops(sb);
5568 	sb->s_root = d_make_root(root);
5569 	if (!sb->s_root) {
5570 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5571 		err = -ENOMEM;
5572 		goto failed_mount4;
5573 	}
5574 
5575 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5576 	if (err == -EROFS) {
5577 		sb->s_flags |= SB_RDONLY;
5578 	} else if (err)
5579 		goto failed_mount4a;
5580 
5581 	ext4_set_resv_clusters(sb);
5582 
5583 	if (test_opt(sb, BLOCK_VALIDITY)) {
5584 		err = ext4_setup_system_zone(sb);
5585 		if (err) {
5586 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5587 				 "zone (%d)", err);
5588 			goto failed_mount4a;
5589 		}
5590 	}
5591 	ext4_fc_replay_cleanup(sb);
5592 
5593 	ext4_ext_init(sb);
5594 
5595 	/*
5596 	 * Enable optimize_scan if number of groups is > threshold. This can be
5597 	 * turned off by passing "mb_optimize_scan=0". This can also be
5598 	 * turned on forcefully by passing "mb_optimize_scan=1".
5599 	 */
5600 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5601 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5602 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5603 		else
5604 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5605 	}
5606 
5607 	err = ext4_mb_init(sb);
5608 	if (err) {
5609 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5610 			 err);
5611 		goto failed_mount5;
5612 	}
5613 
5614 	/*
5615 	 * We can only set up the journal commit callback once
5616 	 * mballoc is initialized
5617 	 */
5618 	if (sbi->s_journal)
5619 		sbi->s_journal->j_commit_callback =
5620 			ext4_journal_commit_callback;
5621 
5622 	err = ext4_percpu_param_init(sbi);
5623 	if (err)
5624 		goto failed_mount6;
5625 
5626 	if (ext4_has_feature_flex_bg(sb))
5627 		if (!ext4_fill_flex_info(sb)) {
5628 			ext4_msg(sb, KERN_ERR,
5629 			       "unable to initialize "
5630 			       "flex_bg meta info!");
5631 			err = -ENOMEM;
5632 			goto failed_mount6;
5633 		}
5634 
5635 	err = ext4_register_li_request(sb, first_not_zeroed);
5636 	if (err)
5637 		goto failed_mount6;
5638 
5639 	err = ext4_init_orphan_info(sb);
5640 	if (err)
5641 		goto failed_mount7;
5642 #ifdef CONFIG_QUOTA
5643 	/* Enable quota usage during mount. */
5644 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5645 		err = ext4_enable_quotas(sb);
5646 		if (err)
5647 			goto failed_mount8;
5648 	}
5649 #endif  /* CONFIG_QUOTA */
5650 
5651 	/*
5652 	 * Save the original bdev mapping's wb_err value which could be
5653 	 * used to detect the metadata async write error.
5654 	 */
5655 	errseq_check_and_advance(&sb->s_bdev->bd_mapping->wb_err,
5656 				 &sbi->s_bdev_wb_err);
5657 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5658 	ext4_orphan_cleanup(sb, es);
5659 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5660 	/*
5661 	 * Update the checksum after updating free space/inode counters and
5662 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5663 	 * checksum in the buffer cache until it is written out and
5664 	 * e2fsprogs programs trying to open a file system immediately
5665 	 * after it is mounted can fail.
5666 	 */
5667 	ext4_superblock_csum_set(sb);
5668 	if (needs_recovery) {
5669 		ext4_msg(sb, KERN_INFO, "recovery complete");
5670 		err = ext4_mark_recovery_complete(sb, es);
5671 		if (err)
5672 			goto failed_mount9;
5673 	}
5674 
5675 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev)) {
5676 		ext4_msg(sb, KERN_WARNING,
5677 			 "mounting with \"discard\" option, but the device does not support discard");
5678 		clear_opt(sb, DISCARD);
5679 	}
5680 
5681 	if (es->s_error_count)
5682 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5683 
5684 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5685 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5686 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5687 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5688 	atomic_set(&sbi->s_warning_count, 0);
5689 	atomic_set(&sbi->s_msg_count, 0);
5690 
5691 	/* Register sysfs after all initializations are complete. */
5692 	err = ext4_register_sysfs(sb);
5693 	if (err)
5694 		goto failed_mount9;
5695 
5696 	return 0;
5697 
5698 failed_mount9:
5699 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5700 failed_mount8: __maybe_unused
5701 	ext4_release_orphan_info(sb);
5702 failed_mount7:
5703 	ext4_unregister_li_request(sb);
5704 failed_mount6:
5705 	ext4_mb_release(sb);
5706 	ext4_flex_groups_free(sbi);
5707 	ext4_percpu_param_destroy(sbi);
5708 failed_mount5:
5709 	ext4_ext_release(sb);
5710 	ext4_release_system_zone(sb);
5711 failed_mount4a:
5712 	dput(sb->s_root);
5713 	sb->s_root = NULL;
5714 failed_mount4:
5715 	ext4_msg(sb, KERN_ERR, "mount failed");
5716 	if (EXT4_SB(sb)->rsv_conversion_wq)
5717 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5718 failed_mount_wq:
5719 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5720 	sbi->s_ea_inode_cache = NULL;
5721 
5722 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5723 	sbi->s_ea_block_cache = NULL;
5724 
5725 	if (sbi->s_journal) {
5726 		ext4_journal_destroy(sbi, sbi->s_journal);
5727 	}
5728 failed_mount3a:
5729 	ext4_es_unregister_shrinker(sbi);
5730 failed_mount3:
5731 	/* flush s_sb_upd_work before sbi destroy */
5732 	flush_work(&sbi->s_sb_upd_work);
5733 	ext4_stop_mmpd(sbi);
5734 	timer_delete_sync(&sbi->s_err_report);
5735 	ext4_group_desc_free(sbi);
5736 failed_mount:
5737 #if IS_ENABLED(CONFIG_UNICODE)
5738 	utf8_unload(sb->s_encoding);
5739 #endif
5740 
5741 #ifdef CONFIG_QUOTA
5742 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5743 		kfree(get_qf_name(sb, sbi, i));
5744 #endif
5745 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5746 	brelse(sbi->s_sbh);
5747 	if (sbi->s_journal_bdev_file) {
5748 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
5749 		bdev_fput(sbi->s_journal_bdev_file);
5750 	}
5751 out_fail:
5752 	invalidate_bdev(sb->s_bdev);
5753 	sb->s_fs_info = NULL;
5754 	return err;
5755 }
5756 
5757 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5758 {
5759 	struct ext4_fs_context *ctx = fc->fs_private;
5760 	struct ext4_sb_info *sbi;
5761 	const char *descr;
5762 	int ret;
5763 
5764 	sbi = ext4_alloc_sbi(sb);
5765 	if (!sbi)
5766 		return -ENOMEM;
5767 
5768 	fc->s_fs_info = sbi;
5769 
5770 	/* Cleanup superblock name */
5771 	strreplace(sb->s_id, '/', '!');
5772 
5773 	sbi->s_sb_block = 1;	/* Default super block location */
5774 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5775 		sbi->s_sb_block = ctx->s_sb_block;
5776 
5777 	ret = __ext4_fill_super(fc, sb);
5778 	if (ret < 0)
5779 		goto free_sbi;
5780 
5781 	if (sbi->s_journal) {
5782 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5783 			descr = " journalled data mode";
5784 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5785 			descr = " ordered data mode";
5786 		else
5787 			descr = " writeback data mode";
5788 	} else
5789 		descr = "out journal";
5790 
5791 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5792 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5793 			 "Quota mode: %s.", &sb->s_uuid,
5794 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5795 			 ext4_quota_mode(sb));
5796 
5797 	/* Update the s_overhead_clusters if necessary */
5798 	ext4_update_overhead(sb, false);
5799 	return 0;
5800 
5801 free_sbi:
5802 	ext4_free_sbi(sbi);
5803 	fc->s_fs_info = NULL;
5804 	return ret;
5805 }
5806 
5807 static int ext4_get_tree(struct fs_context *fc)
5808 {
5809 	return get_tree_bdev(fc, ext4_fill_super);
5810 }
5811 
5812 /*
5813  * Setup any per-fs journal parameters now.  We'll do this both on
5814  * initial mount, once the journal has been initialised but before we've
5815  * done any recovery; and again on any subsequent remount.
5816  */
5817 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5818 {
5819 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5820 
5821 	journal->j_commit_interval = sbi->s_commit_interval;
5822 	journal->j_min_batch_time = sbi->s_min_batch_time;
5823 	journal->j_max_batch_time = sbi->s_max_batch_time;
5824 	ext4_fc_init(sb, journal);
5825 
5826 	write_lock(&journal->j_state_lock);
5827 	if (test_opt(sb, BARRIER))
5828 		journal->j_flags |= JBD2_BARRIER;
5829 	else
5830 		journal->j_flags &= ~JBD2_BARRIER;
5831 	/*
5832 	 * Always enable journal cycle record option, letting the journal
5833 	 * records log transactions continuously between each mount.
5834 	 */
5835 	journal->j_flags |= JBD2_CYCLE_RECORD;
5836 	write_unlock(&journal->j_state_lock);
5837 }
5838 
5839 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5840 					     unsigned int journal_inum)
5841 {
5842 	struct inode *journal_inode;
5843 
5844 	/*
5845 	 * Test for the existence of a valid inode on disk.  Bad things
5846 	 * happen if we iget() an unused inode, as the subsequent iput()
5847 	 * will try to delete it.
5848 	 */
5849 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5850 	if (IS_ERR(journal_inode)) {
5851 		ext4_msg(sb, KERN_ERR, "no journal found");
5852 		return ERR_CAST(journal_inode);
5853 	}
5854 	if (!journal_inode->i_nlink) {
5855 		make_bad_inode(journal_inode);
5856 		iput(journal_inode);
5857 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5858 		return ERR_PTR(-EFSCORRUPTED);
5859 	}
5860 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5861 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5862 		iput(journal_inode);
5863 		return ERR_PTR(-EFSCORRUPTED);
5864 	}
5865 
5866 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5867 		  journal_inode, journal_inode->i_size);
5868 	return journal_inode;
5869 }
5870 
5871 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5872 {
5873 	struct ext4_map_blocks map;
5874 	int ret;
5875 
5876 	if (journal->j_inode == NULL)
5877 		return 0;
5878 
5879 	map.m_lblk = *block;
5880 	map.m_len = 1;
5881 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5882 	if (ret <= 0) {
5883 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5884 			 "journal bmap failed: block %llu ret %d\n",
5885 			 *block, ret);
5886 		jbd2_journal_abort(journal, ret ? ret : -EFSCORRUPTED);
5887 		return ret;
5888 	}
5889 	*block = map.m_pblk;
5890 	return 0;
5891 }
5892 
5893 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5894 					  unsigned int journal_inum)
5895 {
5896 	struct inode *journal_inode;
5897 	journal_t *journal;
5898 
5899 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5900 	if (IS_ERR(journal_inode))
5901 		return ERR_CAST(journal_inode);
5902 
5903 	journal = jbd2_journal_init_inode(journal_inode);
5904 	if (IS_ERR(journal)) {
5905 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5906 		iput(journal_inode);
5907 		return ERR_CAST(journal);
5908 	}
5909 	journal->j_private = sb;
5910 	journal->j_bmap = ext4_journal_bmap;
5911 	ext4_init_journal_params(sb, journal);
5912 	return journal;
5913 }
5914 
5915 static struct file *ext4_get_journal_blkdev(struct super_block *sb,
5916 					dev_t j_dev, ext4_fsblk_t *j_start,
5917 					ext4_fsblk_t *j_len)
5918 {
5919 	struct buffer_head *bh;
5920 	struct block_device *bdev;
5921 	struct file *bdev_file;
5922 	int hblock, blocksize;
5923 	ext4_fsblk_t sb_block;
5924 	unsigned long offset;
5925 	struct ext4_super_block *es;
5926 	int errno;
5927 
5928 	bdev_file = bdev_file_open_by_dev(j_dev,
5929 		BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
5930 		sb, &fs_holder_ops);
5931 	if (IS_ERR(bdev_file)) {
5932 		ext4_msg(sb, KERN_ERR,
5933 			 "failed to open journal device unknown-block(%u,%u) %ld",
5934 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev_file));
5935 		return bdev_file;
5936 	}
5937 
5938 	bdev = file_bdev(bdev_file);
5939 	blocksize = sb->s_blocksize;
5940 	hblock = bdev_logical_block_size(bdev);
5941 	if (blocksize < hblock) {
5942 		ext4_msg(sb, KERN_ERR,
5943 			"blocksize too small for journal device");
5944 		errno = -EINVAL;
5945 		goto out_bdev;
5946 	}
5947 
5948 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5949 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5950 	set_blocksize(bdev_file, blocksize);
5951 	bh = __bread(bdev, sb_block, blocksize);
5952 	if (!bh) {
5953 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5954 		       "external journal");
5955 		errno = -EINVAL;
5956 		goto out_bdev;
5957 	}
5958 
5959 	es = (struct ext4_super_block *) (bh->b_data + offset);
5960 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5961 	    !(le32_to_cpu(es->s_feature_incompat) &
5962 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5963 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
5964 		errno = -EFSCORRUPTED;
5965 		goto out_bh;
5966 	}
5967 
5968 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5969 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5970 	    es->s_checksum != ext4_superblock_csum(es)) {
5971 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
5972 		errno = -EFSCORRUPTED;
5973 		goto out_bh;
5974 	}
5975 
5976 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5977 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5978 		errno = -EFSCORRUPTED;
5979 		goto out_bh;
5980 	}
5981 
5982 	*j_start = sb_block + 1;
5983 	*j_len = ext4_blocks_count(es);
5984 	brelse(bh);
5985 	return bdev_file;
5986 
5987 out_bh:
5988 	brelse(bh);
5989 out_bdev:
5990 	bdev_fput(bdev_file);
5991 	return ERR_PTR(errno);
5992 }
5993 
5994 static journal_t *ext4_open_dev_journal(struct super_block *sb,
5995 					dev_t j_dev)
5996 {
5997 	journal_t *journal;
5998 	ext4_fsblk_t j_start;
5999 	ext4_fsblk_t j_len;
6000 	struct file *bdev_file;
6001 	int errno = 0;
6002 
6003 	bdev_file = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
6004 	if (IS_ERR(bdev_file))
6005 		return ERR_CAST(bdev_file);
6006 
6007 	journal = jbd2_journal_init_dev(file_bdev(bdev_file), sb->s_bdev, j_start,
6008 					j_len, sb->s_blocksize);
6009 	if (IS_ERR(journal)) {
6010 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
6011 		errno = PTR_ERR(journal);
6012 		goto out_bdev;
6013 	}
6014 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
6015 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
6016 					"user (unsupported) - %d",
6017 			be32_to_cpu(journal->j_superblock->s_nr_users));
6018 		errno = -EINVAL;
6019 		goto out_journal;
6020 	}
6021 	journal->j_private = sb;
6022 	EXT4_SB(sb)->s_journal_bdev_file = bdev_file;
6023 	ext4_init_journal_params(sb, journal);
6024 	return journal;
6025 
6026 out_journal:
6027 	ext4_journal_destroy(EXT4_SB(sb), journal);
6028 out_bdev:
6029 	bdev_fput(bdev_file);
6030 	return ERR_PTR(errno);
6031 }
6032 
6033 static int ext4_load_journal(struct super_block *sb,
6034 			     struct ext4_super_block *es,
6035 			     unsigned long journal_devnum)
6036 {
6037 	journal_t *journal;
6038 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
6039 	dev_t journal_dev;
6040 	int err = 0;
6041 	int really_read_only;
6042 	int journal_dev_ro;
6043 
6044 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
6045 		return -EFSCORRUPTED;
6046 
6047 	if (journal_devnum &&
6048 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6049 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
6050 			"numbers have changed");
6051 		journal_dev = new_decode_dev(journal_devnum);
6052 	} else
6053 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
6054 
6055 	if (journal_inum && journal_dev) {
6056 		ext4_msg(sb, KERN_ERR,
6057 			 "filesystem has both journal inode and journal device!");
6058 		return -EINVAL;
6059 	}
6060 
6061 	if (journal_inum) {
6062 		journal = ext4_open_inode_journal(sb, journal_inum);
6063 		if (IS_ERR(journal))
6064 			return PTR_ERR(journal);
6065 	} else {
6066 		journal = ext4_open_dev_journal(sb, journal_dev);
6067 		if (IS_ERR(journal))
6068 			return PTR_ERR(journal);
6069 	}
6070 
6071 	journal_dev_ro = bdev_read_only(journal->j_dev);
6072 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
6073 
6074 	if (journal_dev_ro && !sb_rdonly(sb)) {
6075 		ext4_msg(sb, KERN_ERR,
6076 			 "journal device read-only, try mounting with '-o ro'");
6077 		err = -EROFS;
6078 		goto err_out;
6079 	}
6080 
6081 	/*
6082 	 * Are we loading a blank journal or performing recovery after a
6083 	 * crash?  For recovery, we need to check in advance whether we
6084 	 * can get read-write access to the device.
6085 	 */
6086 	if (ext4_has_feature_journal_needs_recovery(sb)) {
6087 		if (sb_rdonly(sb)) {
6088 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
6089 					"required on readonly filesystem");
6090 			if (really_read_only) {
6091 				ext4_msg(sb, KERN_ERR, "write access "
6092 					"unavailable, cannot proceed "
6093 					"(try mounting with noload)");
6094 				err = -EROFS;
6095 				goto err_out;
6096 			}
6097 			ext4_msg(sb, KERN_INFO, "write access will "
6098 			       "be enabled during recovery");
6099 		}
6100 	}
6101 
6102 	if (!(journal->j_flags & JBD2_BARRIER))
6103 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6104 
6105 	if (!ext4_has_feature_journal_needs_recovery(sb))
6106 		err = jbd2_journal_wipe(journal, !really_read_only);
6107 	if (!err) {
6108 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6109 		__le16 orig_state;
6110 		bool changed = false;
6111 
6112 		if (save)
6113 			memcpy(save, ((char *) es) +
6114 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6115 		err = jbd2_journal_load(journal);
6116 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6117 				   save, EXT4_S_ERR_LEN)) {
6118 			memcpy(((char *) es) + EXT4_S_ERR_START,
6119 			       save, EXT4_S_ERR_LEN);
6120 			changed = true;
6121 		}
6122 		kfree(save);
6123 		orig_state = es->s_state;
6124 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6125 					   EXT4_ERROR_FS);
6126 		if (orig_state != es->s_state)
6127 			changed = true;
6128 		/* Write out restored error information to the superblock */
6129 		if (changed && !really_read_only) {
6130 			int err2;
6131 			err2 = ext4_commit_super(sb);
6132 			err = err ? : err2;
6133 		}
6134 	}
6135 
6136 	if (err) {
6137 		ext4_msg(sb, KERN_ERR, "error loading journal");
6138 		goto err_out;
6139 	}
6140 
6141 	EXT4_SB(sb)->s_journal = journal;
6142 	err = ext4_clear_journal_err(sb, es);
6143 	if (err) {
6144 		ext4_journal_destroy(EXT4_SB(sb), journal);
6145 		return err;
6146 	}
6147 
6148 	if (!really_read_only && journal_devnum &&
6149 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6150 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6151 		ext4_commit_super(sb);
6152 	}
6153 	if (!really_read_only && journal_inum &&
6154 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6155 		es->s_journal_inum = cpu_to_le32(journal_inum);
6156 		ext4_commit_super(sb);
6157 	}
6158 
6159 	return 0;
6160 
6161 err_out:
6162 	ext4_journal_destroy(EXT4_SB(sb), journal);
6163 	return err;
6164 }
6165 
6166 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6167 static void ext4_update_super(struct super_block *sb)
6168 {
6169 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6170 	struct ext4_super_block *es = sbi->s_es;
6171 	struct buffer_head *sbh = sbi->s_sbh;
6172 
6173 	lock_buffer(sbh);
6174 	/*
6175 	 * If the file system is mounted read-only, don't update the
6176 	 * superblock write time.  This avoids updating the superblock
6177 	 * write time when we are mounting the root file system
6178 	 * read/only but we need to replay the journal; at that point,
6179 	 * for people who are east of GMT and who make their clock
6180 	 * tick in localtime for Windows bug-for-bug compatibility,
6181 	 * the clock is set in the future, and this will cause e2fsck
6182 	 * to complain and force a full file system check.
6183 	 */
6184 	if (!sb_rdonly(sb))
6185 		ext4_update_tstamp(es, s_wtime);
6186 	es->s_kbytes_written =
6187 		cpu_to_le64(sbi->s_kbytes_written +
6188 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6189 		      sbi->s_sectors_written_start) >> 1));
6190 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6191 		ext4_free_blocks_count_set(es,
6192 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6193 				&sbi->s_freeclusters_counter)));
6194 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6195 		es->s_free_inodes_count =
6196 			cpu_to_le32(percpu_counter_sum_positive(
6197 				&sbi->s_freeinodes_counter));
6198 	/* Copy error information to the on-disk superblock */
6199 	spin_lock(&sbi->s_error_lock);
6200 	if (sbi->s_add_error_count > 0) {
6201 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6202 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6203 			__ext4_update_tstamp(&es->s_first_error_time,
6204 					     &es->s_first_error_time_hi,
6205 					     sbi->s_first_error_time);
6206 			strtomem_pad(es->s_first_error_func,
6207 				     sbi->s_first_error_func, 0);
6208 			es->s_first_error_line =
6209 				cpu_to_le32(sbi->s_first_error_line);
6210 			es->s_first_error_ino =
6211 				cpu_to_le32(sbi->s_first_error_ino);
6212 			es->s_first_error_block =
6213 				cpu_to_le64(sbi->s_first_error_block);
6214 			es->s_first_error_errcode =
6215 				ext4_errno_to_code(sbi->s_first_error_code);
6216 		}
6217 		__ext4_update_tstamp(&es->s_last_error_time,
6218 				     &es->s_last_error_time_hi,
6219 				     sbi->s_last_error_time);
6220 		strtomem_pad(es->s_last_error_func, sbi->s_last_error_func, 0);
6221 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6222 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6223 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6224 		es->s_last_error_errcode =
6225 				ext4_errno_to_code(sbi->s_last_error_code);
6226 		/*
6227 		 * Start the daily error reporting function if it hasn't been
6228 		 * started already
6229 		 */
6230 		if (!es->s_error_count)
6231 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6232 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6233 		sbi->s_add_error_count = 0;
6234 	}
6235 	spin_unlock(&sbi->s_error_lock);
6236 
6237 	ext4_superblock_csum_set(sb);
6238 	unlock_buffer(sbh);
6239 }
6240 
6241 static int ext4_commit_super(struct super_block *sb)
6242 {
6243 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6244 
6245 	if (!sbh)
6246 		return -EINVAL;
6247 
6248 	ext4_update_super(sb);
6249 
6250 	lock_buffer(sbh);
6251 	/* Buffer got discarded which means block device got invalidated */
6252 	if (!buffer_mapped(sbh)) {
6253 		unlock_buffer(sbh);
6254 		return -EIO;
6255 	}
6256 
6257 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6258 		/*
6259 		 * Oh, dear.  A previous attempt to write the
6260 		 * superblock failed.  This could happen because the
6261 		 * USB device was yanked out.  Or it could happen to
6262 		 * be a transient write error and maybe the block will
6263 		 * be remapped.  Nothing we can do but to retry the
6264 		 * write and hope for the best.
6265 		 */
6266 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6267 		       "superblock detected");
6268 		clear_buffer_write_io_error(sbh);
6269 		set_buffer_uptodate(sbh);
6270 	}
6271 	get_bh(sbh);
6272 	/* Clear potential dirty bit if it was journalled update */
6273 	clear_buffer_dirty(sbh);
6274 	sbh->b_end_io = end_buffer_write_sync;
6275 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6276 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6277 	wait_on_buffer(sbh);
6278 	if (buffer_write_io_error(sbh)) {
6279 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6280 		       "superblock");
6281 		clear_buffer_write_io_error(sbh);
6282 		set_buffer_uptodate(sbh);
6283 		return -EIO;
6284 	}
6285 	return 0;
6286 }
6287 
6288 /*
6289  * Have we just finished recovery?  If so, and if we are mounting (or
6290  * remounting) the filesystem readonly, then we will end up with a
6291  * consistent fs on disk.  Record that fact.
6292  */
6293 static int ext4_mark_recovery_complete(struct super_block *sb,
6294 				       struct ext4_super_block *es)
6295 {
6296 	int err;
6297 	journal_t *journal = EXT4_SB(sb)->s_journal;
6298 
6299 	if (!ext4_has_feature_journal(sb)) {
6300 		if (journal != NULL) {
6301 			ext4_error(sb, "Journal got removed while the fs was "
6302 				   "mounted!");
6303 			return -EFSCORRUPTED;
6304 		}
6305 		return 0;
6306 	}
6307 	jbd2_journal_lock_updates(journal);
6308 	err = jbd2_journal_flush(journal, 0);
6309 	if (err < 0)
6310 		goto out;
6311 
6312 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6313 	    ext4_has_feature_orphan_present(sb))) {
6314 		if (!ext4_orphan_file_empty(sb)) {
6315 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6316 			err = -EFSCORRUPTED;
6317 			goto out;
6318 		}
6319 		ext4_clear_feature_journal_needs_recovery(sb);
6320 		ext4_clear_feature_orphan_present(sb);
6321 		ext4_commit_super(sb);
6322 	}
6323 out:
6324 	jbd2_journal_unlock_updates(journal);
6325 	return err;
6326 }
6327 
6328 /*
6329  * If we are mounting (or read-write remounting) a filesystem whose journal
6330  * has recorded an error from a previous lifetime, move that error to the
6331  * main filesystem now.
6332  */
6333 static int ext4_clear_journal_err(struct super_block *sb,
6334 				   struct ext4_super_block *es)
6335 {
6336 	journal_t *journal;
6337 	int j_errno;
6338 	const char *errstr;
6339 
6340 	if (!ext4_has_feature_journal(sb)) {
6341 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6342 		return -EFSCORRUPTED;
6343 	}
6344 
6345 	journal = EXT4_SB(sb)->s_journal;
6346 
6347 	/*
6348 	 * Now check for any error status which may have been recorded in the
6349 	 * journal by a prior ext4_error() or ext4_abort()
6350 	 */
6351 
6352 	j_errno = jbd2_journal_errno(journal);
6353 	if (j_errno) {
6354 		char nbuf[16];
6355 
6356 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6357 		ext4_warning(sb, "Filesystem error recorded "
6358 			     "from previous mount: %s", errstr);
6359 
6360 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6361 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6362 		j_errno = ext4_commit_super(sb);
6363 		if (j_errno)
6364 			return j_errno;
6365 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6366 
6367 		jbd2_journal_clear_err(journal);
6368 		jbd2_journal_update_sb_errno(journal);
6369 	}
6370 	return 0;
6371 }
6372 
6373 /*
6374  * Force the running and committing transactions to commit,
6375  * and wait on the commit.
6376  */
6377 int ext4_force_commit(struct super_block *sb)
6378 {
6379 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6380 }
6381 
6382 static int ext4_sync_fs(struct super_block *sb, int wait)
6383 {
6384 	int ret = 0;
6385 	tid_t target;
6386 	bool needs_barrier = false;
6387 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6388 
6389 	ret = ext4_emergency_state(sb);
6390 	if (unlikely(ret))
6391 		return ret;
6392 
6393 	trace_ext4_sync_fs(sb, wait);
6394 	flush_workqueue(sbi->rsv_conversion_wq);
6395 	/*
6396 	 * Writeback quota in non-journalled quota case - journalled quota has
6397 	 * no dirty dquots
6398 	 */
6399 	dquot_writeback_dquots(sb, -1);
6400 	/*
6401 	 * Data writeback is possible w/o journal transaction, so barrier must
6402 	 * being sent at the end of the function. But we can skip it if
6403 	 * transaction_commit will do it for us.
6404 	 */
6405 	if (sbi->s_journal) {
6406 		target = jbd2_get_latest_transaction(sbi->s_journal);
6407 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6408 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6409 			needs_barrier = true;
6410 
6411 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6412 			if (wait)
6413 				ret = jbd2_log_wait_commit(sbi->s_journal,
6414 							   target);
6415 		}
6416 	} else if (wait && test_opt(sb, BARRIER))
6417 		needs_barrier = true;
6418 	if (needs_barrier) {
6419 		int err;
6420 		err = blkdev_issue_flush(sb->s_bdev);
6421 		if (!ret)
6422 			ret = err;
6423 	}
6424 
6425 	return ret;
6426 }
6427 
6428 /*
6429  * LVM calls this function before a (read-only) snapshot is created.  This
6430  * gives us a chance to flush the journal completely and mark the fs clean.
6431  *
6432  * Note that only this function cannot bring a filesystem to be in a clean
6433  * state independently. It relies on upper layer to stop all data & metadata
6434  * modifications.
6435  */
6436 static int ext4_freeze(struct super_block *sb)
6437 {
6438 	int error = 0;
6439 	journal_t *journal = EXT4_SB(sb)->s_journal;
6440 
6441 	if (journal) {
6442 		/* Now we set up the journal barrier. */
6443 		jbd2_journal_lock_updates(journal);
6444 
6445 		/*
6446 		 * Don't clear the needs_recovery flag if we failed to
6447 		 * flush the journal.
6448 		 */
6449 		error = jbd2_journal_flush(journal, 0);
6450 		if (error < 0)
6451 			goto out;
6452 
6453 		/* Journal blocked and flushed, clear needs_recovery flag. */
6454 		ext4_clear_feature_journal_needs_recovery(sb);
6455 		if (ext4_orphan_file_empty(sb))
6456 			ext4_clear_feature_orphan_present(sb);
6457 	}
6458 
6459 	error = ext4_commit_super(sb);
6460 out:
6461 	if (journal)
6462 		/* we rely on upper layer to stop further updates */
6463 		jbd2_journal_unlock_updates(journal);
6464 	return error;
6465 }
6466 
6467 /*
6468  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6469  * flag here, even though the filesystem is not technically dirty yet.
6470  */
6471 static int ext4_unfreeze(struct super_block *sb)
6472 {
6473 	if (ext4_emergency_state(sb))
6474 		return 0;
6475 
6476 	if (EXT4_SB(sb)->s_journal) {
6477 		/* Reset the needs_recovery flag before the fs is unlocked. */
6478 		ext4_set_feature_journal_needs_recovery(sb);
6479 		if (ext4_has_feature_orphan_file(sb))
6480 			ext4_set_feature_orphan_present(sb);
6481 	}
6482 
6483 	ext4_commit_super(sb);
6484 	return 0;
6485 }
6486 
6487 /*
6488  * Structure to save mount options for ext4_remount's benefit
6489  */
6490 struct ext4_mount_options {
6491 	unsigned long s_mount_opt;
6492 	unsigned long s_mount_opt2;
6493 	kuid_t s_resuid;
6494 	kgid_t s_resgid;
6495 	unsigned long s_commit_interval;
6496 	u32 s_min_batch_time, s_max_batch_time;
6497 #ifdef CONFIG_QUOTA
6498 	int s_jquota_fmt;
6499 	char *s_qf_names[EXT4_MAXQUOTAS];
6500 #endif
6501 };
6502 
6503 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6504 {
6505 	struct ext4_fs_context *ctx = fc->fs_private;
6506 	struct ext4_super_block *es;
6507 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6508 	unsigned long old_sb_flags;
6509 	struct ext4_mount_options old_opts;
6510 	ext4_group_t g;
6511 	int err = 0;
6512 	int alloc_ctx;
6513 #ifdef CONFIG_QUOTA
6514 	int enable_quota = 0;
6515 	int i, j;
6516 	char *to_free[EXT4_MAXQUOTAS];
6517 #endif
6518 
6519 
6520 	/* Store the original options */
6521 	old_sb_flags = sb->s_flags;
6522 	old_opts.s_mount_opt = sbi->s_mount_opt;
6523 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6524 	old_opts.s_resuid = sbi->s_resuid;
6525 	old_opts.s_resgid = sbi->s_resgid;
6526 	old_opts.s_commit_interval = sbi->s_commit_interval;
6527 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6528 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6529 #ifdef CONFIG_QUOTA
6530 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6531 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6532 		if (sbi->s_qf_names[i]) {
6533 			char *qf_name = get_qf_name(sb, sbi, i);
6534 
6535 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6536 			if (!old_opts.s_qf_names[i]) {
6537 				for (j = 0; j < i; j++)
6538 					kfree(old_opts.s_qf_names[j]);
6539 				return -ENOMEM;
6540 			}
6541 		} else
6542 			old_opts.s_qf_names[i] = NULL;
6543 #endif
6544 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6545 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6546 			ctx->journal_ioprio =
6547 				sbi->s_journal->j_task->io_context->ioprio;
6548 		else
6549 			ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
6550 
6551 	}
6552 
6553 	if ((ctx->spec & EXT4_SPEC_s_stripe) &&
6554 	    ext4_is_stripe_incompatible(sb, ctx->s_stripe)) {
6555 		ext4_msg(sb, KERN_WARNING,
6556 			 "stripe (%lu) is not aligned with cluster size (%u), "
6557 			 "stripe is disabled",
6558 			 ctx->s_stripe, sbi->s_cluster_ratio);
6559 		ctx->s_stripe = 0;
6560 	}
6561 
6562 	/*
6563 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6564 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6565 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6566 	 * here s_writepages_rwsem to avoid race between writepages ops and
6567 	 * remount.
6568 	 */
6569 	alloc_ctx = ext4_writepages_down_write(sb);
6570 	ext4_apply_options(fc, sb);
6571 	ext4_writepages_up_write(sb, alloc_ctx);
6572 
6573 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6574 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6575 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6576 			 "during remount not supported; ignoring");
6577 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6578 	}
6579 
6580 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6581 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6582 			ext4_msg(sb, KERN_ERR, "can't mount with "
6583 				 "both data=journal and delalloc");
6584 			err = -EINVAL;
6585 			goto restore_opts;
6586 		}
6587 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6588 			ext4_msg(sb, KERN_ERR, "can't mount with "
6589 				 "both data=journal and dioread_nolock");
6590 			err = -EINVAL;
6591 			goto restore_opts;
6592 		}
6593 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6594 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6595 			ext4_msg(sb, KERN_ERR, "can't mount with "
6596 				"journal_async_commit in data=ordered mode");
6597 			err = -EINVAL;
6598 			goto restore_opts;
6599 		}
6600 	}
6601 
6602 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6603 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6604 		err = -EINVAL;
6605 		goto restore_opts;
6606 	}
6607 
6608 	if ((old_opts.s_mount_opt & EXT4_MOUNT_DELALLOC) &&
6609 	    !test_opt(sb, DELALLOC)) {
6610 		ext4_msg(sb, KERN_ERR, "can't disable delalloc during remount");
6611 		err = -EINVAL;
6612 		goto restore_opts;
6613 	}
6614 
6615 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6616 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6617 
6618 	es = sbi->s_es;
6619 
6620 	if (sbi->s_journal) {
6621 		ext4_init_journal_params(sb, sbi->s_journal);
6622 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6623 	}
6624 
6625 	/* Flush outstanding errors before changing fs state */
6626 	flush_work(&sbi->s_sb_upd_work);
6627 
6628 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6629 		if (ext4_emergency_state(sb)) {
6630 			err = -EROFS;
6631 			goto restore_opts;
6632 		}
6633 
6634 		if (fc->sb_flags & SB_RDONLY) {
6635 			err = sync_filesystem(sb);
6636 			if (err < 0)
6637 				goto restore_opts;
6638 			err = dquot_suspend(sb, -1);
6639 			if (err < 0)
6640 				goto restore_opts;
6641 
6642 			/*
6643 			 * First of all, the unconditional stuff we have to do
6644 			 * to disable replay of the journal when we next remount
6645 			 */
6646 			sb->s_flags |= SB_RDONLY;
6647 
6648 			/*
6649 			 * OK, test if we are remounting a valid rw partition
6650 			 * readonly, and if so set the rdonly flag and then
6651 			 * mark the partition as valid again.
6652 			 */
6653 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6654 			    (sbi->s_mount_state & EXT4_VALID_FS))
6655 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6656 
6657 			if (sbi->s_journal) {
6658 				/*
6659 				 * We let remount-ro finish even if marking fs
6660 				 * as clean failed...
6661 				 */
6662 				ext4_mark_recovery_complete(sb, es);
6663 			}
6664 		} else {
6665 			/* Make sure we can mount this feature set readwrite */
6666 			if (ext4_has_feature_readonly(sb) ||
6667 			    !ext4_feature_set_ok(sb, 0)) {
6668 				err = -EROFS;
6669 				goto restore_opts;
6670 			}
6671 			/*
6672 			 * Make sure the group descriptor checksums
6673 			 * are sane.  If they aren't, refuse to remount r/w.
6674 			 */
6675 			for (g = 0; g < sbi->s_groups_count; g++) {
6676 				struct ext4_group_desc *gdp =
6677 					ext4_get_group_desc(sb, g, NULL);
6678 
6679 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6680 					ext4_msg(sb, KERN_ERR,
6681 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6682 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6683 					       le16_to_cpu(gdp->bg_checksum));
6684 					err = -EFSBADCRC;
6685 					goto restore_opts;
6686 				}
6687 			}
6688 
6689 			/*
6690 			 * If we have an unprocessed orphan list hanging
6691 			 * around from a previously readonly bdev mount,
6692 			 * require a full umount/remount for now.
6693 			 */
6694 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6695 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6696 				       "remount RDWR because of unprocessed "
6697 				       "orphan inode list.  Please "
6698 				       "umount/remount instead");
6699 				err = -EINVAL;
6700 				goto restore_opts;
6701 			}
6702 
6703 			/*
6704 			 * Mounting a RDONLY partition read-write, so reread
6705 			 * and store the current valid flag.  (It may have
6706 			 * been changed by e2fsck since we originally mounted
6707 			 * the partition.)
6708 			 */
6709 			if (sbi->s_journal) {
6710 				err = ext4_clear_journal_err(sb, es);
6711 				if (err)
6712 					goto restore_opts;
6713 			}
6714 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6715 					      ~EXT4_FC_REPLAY);
6716 
6717 			err = ext4_setup_super(sb, es, 0);
6718 			if (err)
6719 				goto restore_opts;
6720 
6721 			sb->s_flags &= ~SB_RDONLY;
6722 			if (ext4_has_feature_mmp(sb)) {
6723 				err = ext4_multi_mount_protect(sb,
6724 						le64_to_cpu(es->s_mmp_block));
6725 				if (err)
6726 					goto restore_opts;
6727 			}
6728 #ifdef CONFIG_QUOTA
6729 			enable_quota = 1;
6730 #endif
6731 		}
6732 	}
6733 
6734 	/*
6735 	 * Handle creation of system zone data early because it can fail.
6736 	 * Releasing of existing data is done when we are sure remount will
6737 	 * succeed.
6738 	 */
6739 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6740 		err = ext4_setup_system_zone(sb);
6741 		if (err)
6742 			goto restore_opts;
6743 	}
6744 
6745 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6746 		err = ext4_commit_super(sb);
6747 		if (err)
6748 			goto restore_opts;
6749 	}
6750 
6751 #ifdef CONFIG_QUOTA
6752 	if (enable_quota) {
6753 		if (sb_any_quota_suspended(sb))
6754 			dquot_resume(sb, -1);
6755 		else if (ext4_has_feature_quota(sb)) {
6756 			err = ext4_enable_quotas(sb);
6757 			if (err)
6758 				goto restore_opts;
6759 		}
6760 	}
6761 	/* Release old quota file names */
6762 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6763 		kfree(old_opts.s_qf_names[i]);
6764 #endif
6765 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6766 		ext4_release_system_zone(sb);
6767 
6768 	/*
6769 	 * Reinitialize lazy itable initialization thread based on
6770 	 * current settings
6771 	 */
6772 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6773 		ext4_unregister_li_request(sb);
6774 	else {
6775 		ext4_group_t first_not_zeroed;
6776 		first_not_zeroed = ext4_has_uninit_itable(sb);
6777 		ext4_register_li_request(sb, first_not_zeroed);
6778 	}
6779 
6780 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6781 		ext4_stop_mmpd(sbi);
6782 
6783 	/*
6784 	 * Handle aborting the filesystem as the last thing during remount to
6785 	 * avoid obsure errors during remount when some option changes fail to
6786 	 * apply due to shutdown filesystem.
6787 	 */
6788 	if (test_opt2(sb, ABORT))
6789 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6790 
6791 	return 0;
6792 
6793 restore_opts:
6794 	/*
6795 	 * If there was a failing r/w to ro transition, we may need to
6796 	 * re-enable quota
6797 	 */
6798 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6799 	    sb_any_quota_suspended(sb))
6800 		dquot_resume(sb, -1);
6801 
6802 	alloc_ctx = ext4_writepages_down_write(sb);
6803 	sb->s_flags = old_sb_flags;
6804 	sbi->s_mount_opt = old_opts.s_mount_opt;
6805 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6806 	sbi->s_resuid = old_opts.s_resuid;
6807 	sbi->s_resgid = old_opts.s_resgid;
6808 	sbi->s_commit_interval = old_opts.s_commit_interval;
6809 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6810 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6811 	ext4_writepages_up_write(sb, alloc_ctx);
6812 
6813 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6814 		ext4_release_system_zone(sb);
6815 #ifdef CONFIG_QUOTA
6816 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6817 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6818 		to_free[i] = get_qf_name(sb, sbi, i);
6819 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6820 	}
6821 	synchronize_rcu();
6822 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6823 		kfree(to_free[i]);
6824 #endif
6825 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6826 		ext4_stop_mmpd(sbi);
6827 	return err;
6828 }
6829 
6830 static int ext4_reconfigure(struct fs_context *fc)
6831 {
6832 	struct super_block *sb = fc->root->d_sb;
6833 	int ret;
6834 	bool old_ro = sb_rdonly(sb);
6835 
6836 	fc->s_fs_info = EXT4_SB(sb);
6837 
6838 	ret = ext4_check_opt_consistency(fc, sb);
6839 	if (ret < 0)
6840 		return ret;
6841 
6842 	ret = __ext4_remount(fc, sb);
6843 	if (ret < 0)
6844 		return ret;
6845 
6846 	ext4_msg(sb, KERN_INFO, "re-mounted %pU%s.",
6847 		 &sb->s_uuid,
6848 		 (old_ro != sb_rdonly(sb)) ? (sb_rdonly(sb) ? " ro" : " r/w") : "");
6849 
6850 	return 0;
6851 }
6852 
6853 #ifdef CONFIG_QUOTA
6854 static int ext4_statfs_project(struct super_block *sb,
6855 			       kprojid_t projid, struct kstatfs *buf)
6856 {
6857 	struct kqid qid;
6858 	struct dquot *dquot;
6859 	u64 limit;
6860 	u64 curblock;
6861 
6862 	qid = make_kqid_projid(projid);
6863 	dquot = dqget(sb, qid);
6864 	if (IS_ERR(dquot))
6865 		return PTR_ERR(dquot);
6866 	spin_lock(&dquot->dq_dqb_lock);
6867 
6868 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6869 			     dquot->dq_dqb.dqb_bhardlimit);
6870 	limit >>= sb->s_blocksize_bits;
6871 
6872 	if (limit) {
6873 		uint64_t	remaining = 0;
6874 
6875 		curblock = (dquot->dq_dqb.dqb_curspace +
6876 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6877 		if (limit > curblock)
6878 			remaining = limit - curblock;
6879 
6880 		buf->f_blocks = min(buf->f_blocks, limit);
6881 		buf->f_bfree = min(buf->f_bfree, remaining);
6882 		buf->f_bavail = min(buf->f_bavail, remaining);
6883 	}
6884 
6885 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6886 			     dquot->dq_dqb.dqb_ihardlimit);
6887 	if (limit) {
6888 		uint64_t	remaining = 0;
6889 
6890 		if (limit > dquot->dq_dqb.dqb_curinodes)
6891 			remaining = limit - dquot->dq_dqb.dqb_curinodes;
6892 
6893 		buf->f_files = min(buf->f_files, limit);
6894 		buf->f_ffree = min(buf->f_ffree, remaining);
6895 	}
6896 
6897 	spin_unlock(&dquot->dq_dqb_lock);
6898 	dqput(dquot);
6899 	return 0;
6900 }
6901 #endif
6902 
6903 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6904 {
6905 	struct super_block *sb = dentry->d_sb;
6906 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6907 	struct ext4_super_block *es = sbi->s_es;
6908 	ext4_fsblk_t overhead = 0, resv_blocks;
6909 	s64 bfree;
6910 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6911 
6912 	if (!test_opt(sb, MINIX_DF))
6913 		overhead = sbi->s_overhead;
6914 
6915 	buf->f_type = EXT4_SUPER_MAGIC;
6916 	buf->f_bsize = sb->s_blocksize;
6917 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6918 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6919 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6920 	/* prevent underflow in case that few free space is available */
6921 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6922 	buf->f_bavail = buf->f_bfree -
6923 			(ext4_r_blocks_count(es) + resv_blocks);
6924 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6925 		buf->f_bavail = 0;
6926 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6927 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6928 	buf->f_namelen = EXT4_NAME_LEN;
6929 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6930 
6931 #ifdef CONFIG_QUOTA
6932 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6933 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6934 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6935 #endif
6936 	return 0;
6937 }
6938 
6939 
6940 #ifdef CONFIG_QUOTA
6941 
6942 /*
6943  * Helper functions so that transaction is started before we acquire dqio_sem
6944  * to keep correct lock ordering of transaction > dqio_sem
6945  */
6946 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6947 {
6948 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6949 }
6950 
6951 static int ext4_write_dquot(struct dquot *dquot)
6952 {
6953 	int ret, err;
6954 	handle_t *handle;
6955 	struct inode *inode;
6956 
6957 	inode = dquot_to_inode(dquot);
6958 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6959 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6960 	if (IS_ERR(handle))
6961 		return PTR_ERR(handle);
6962 	ret = dquot_commit(dquot);
6963 	if (ret < 0)
6964 		ext4_error_err(dquot->dq_sb, -ret,
6965 			       "Failed to commit dquot type %d",
6966 			       dquot->dq_id.type);
6967 	err = ext4_journal_stop(handle);
6968 	if (!ret)
6969 		ret = err;
6970 	return ret;
6971 }
6972 
6973 static int ext4_acquire_dquot(struct dquot *dquot)
6974 {
6975 	int ret, err;
6976 	handle_t *handle;
6977 
6978 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6979 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6980 	if (IS_ERR(handle))
6981 		return PTR_ERR(handle);
6982 	ret = dquot_acquire(dquot);
6983 	if (ret < 0)
6984 		ext4_error_err(dquot->dq_sb, -ret,
6985 			      "Failed to acquire dquot type %d",
6986 			      dquot->dq_id.type);
6987 	err = ext4_journal_stop(handle);
6988 	if (!ret)
6989 		ret = err;
6990 	return ret;
6991 }
6992 
6993 static int ext4_release_dquot(struct dquot *dquot)
6994 {
6995 	int ret, err;
6996 	handle_t *handle;
6997 	bool freeze_protected = false;
6998 
6999 	/*
7000 	 * Trying to sb_start_intwrite() in a running transaction
7001 	 * can result in a deadlock. Further, running transactions
7002 	 * are already protected from freezing.
7003 	 */
7004 	if (!ext4_journal_current_handle()) {
7005 		sb_start_intwrite(dquot->dq_sb);
7006 		freeze_protected = true;
7007 	}
7008 
7009 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
7010 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
7011 	if (IS_ERR(handle)) {
7012 		/* Release dquot anyway to avoid endless cycle in dqput() */
7013 		dquot_release(dquot);
7014 		if (freeze_protected)
7015 			sb_end_intwrite(dquot->dq_sb);
7016 		return PTR_ERR(handle);
7017 	}
7018 	ret = dquot_release(dquot);
7019 	if (ret < 0)
7020 		ext4_error_err(dquot->dq_sb, -ret,
7021 			       "Failed to release dquot type %d",
7022 			       dquot->dq_id.type);
7023 	err = ext4_journal_stop(handle);
7024 	if (!ret)
7025 		ret = err;
7026 
7027 	if (freeze_protected)
7028 		sb_end_intwrite(dquot->dq_sb);
7029 
7030 	return ret;
7031 }
7032 
7033 static int ext4_mark_dquot_dirty(struct dquot *dquot)
7034 {
7035 	struct super_block *sb = dquot->dq_sb;
7036 
7037 	if (ext4_is_quota_journalled(sb)) {
7038 		dquot_mark_dquot_dirty(dquot);
7039 		return ext4_write_dquot(dquot);
7040 	} else {
7041 		return dquot_mark_dquot_dirty(dquot);
7042 	}
7043 }
7044 
7045 static int ext4_write_info(struct super_block *sb, int type)
7046 {
7047 	int ret, err;
7048 	handle_t *handle;
7049 
7050 	/* Data block + inode block */
7051 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
7052 	if (IS_ERR(handle))
7053 		return PTR_ERR(handle);
7054 	ret = dquot_commit_info(sb, type);
7055 	err = ext4_journal_stop(handle);
7056 	if (!ret)
7057 		ret = err;
7058 	return ret;
7059 }
7060 
7061 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
7062 {
7063 	struct ext4_inode_info *ei = EXT4_I(inode);
7064 
7065 	/* The first argument of lockdep_set_subclass has to be
7066 	 * *exactly* the same as the argument to init_rwsem() --- in
7067 	 * this case, in init_once() --- or lockdep gets unhappy
7068 	 * because the name of the lock is set using the
7069 	 * stringification of the argument to init_rwsem().
7070 	 */
7071 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
7072 	lockdep_set_subclass(&ei->i_data_sem, subclass);
7073 }
7074 
7075 /*
7076  * Standard function to be called on quota_on
7077  */
7078 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
7079 			 const struct path *path)
7080 {
7081 	int err;
7082 
7083 	if (!test_opt(sb, QUOTA))
7084 		return -EINVAL;
7085 
7086 	/* Quotafile not on the same filesystem? */
7087 	if (path->dentry->d_sb != sb)
7088 		return -EXDEV;
7089 
7090 	/* Quota already enabled for this file? */
7091 	if (IS_NOQUOTA(d_inode(path->dentry)))
7092 		return -EBUSY;
7093 
7094 	/* Journaling quota? */
7095 	if (EXT4_SB(sb)->s_qf_names[type]) {
7096 		/* Quotafile not in fs root? */
7097 		if (path->dentry->d_parent != sb->s_root)
7098 			ext4_msg(sb, KERN_WARNING,
7099 				"Quota file not on filesystem root. "
7100 				"Journaled quota will not work");
7101 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
7102 	} else {
7103 		/*
7104 		 * Clear the flag just in case mount options changed since
7105 		 * last time.
7106 		 */
7107 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
7108 	}
7109 
7110 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
7111 	err = dquot_quota_on(sb, type, format_id, path);
7112 	if (!err) {
7113 		struct inode *inode = d_inode(path->dentry);
7114 		handle_t *handle;
7115 
7116 		/*
7117 		 * Set inode flags to prevent userspace from messing with quota
7118 		 * files. If this fails, we return success anyway since quotas
7119 		 * are already enabled and this is not a hard failure.
7120 		 */
7121 		inode_lock(inode);
7122 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7123 		if (IS_ERR(handle))
7124 			goto unlock_inode;
7125 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
7126 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
7127 				S_NOATIME | S_IMMUTABLE);
7128 		err = ext4_mark_inode_dirty(handle, inode);
7129 		ext4_journal_stop(handle);
7130 	unlock_inode:
7131 		inode_unlock(inode);
7132 		if (err)
7133 			dquot_quota_off(sb, type);
7134 	}
7135 	if (err)
7136 		lockdep_set_quota_inode(path->dentry->d_inode,
7137 					     I_DATA_SEM_NORMAL);
7138 	return err;
7139 }
7140 
7141 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
7142 {
7143 	switch (type) {
7144 	case USRQUOTA:
7145 		return qf_inum == EXT4_USR_QUOTA_INO;
7146 	case GRPQUOTA:
7147 		return qf_inum == EXT4_GRP_QUOTA_INO;
7148 	case PRJQUOTA:
7149 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7150 	default:
7151 		BUG();
7152 	}
7153 }
7154 
7155 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7156 			     unsigned int flags)
7157 {
7158 	int err;
7159 	struct inode *qf_inode;
7160 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7161 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7162 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7163 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7164 	};
7165 
7166 	BUG_ON(!ext4_has_feature_quota(sb));
7167 
7168 	if (!qf_inums[type])
7169 		return -EPERM;
7170 
7171 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7172 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7173 				qf_inums[type], type);
7174 		return -EUCLEAN;
7175 	}
7176 
7177 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7178 	if (IS_ERR(qf_inode)) {
7179 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7180 				qf_inums[type], type);
7181 		return PTR_ERR(qf_inode);
7182 	}
7183 
7184 	/* Don't account quota for quota files to avoid recursion */
7185 	qf_inode->i_flags |= S_NOQUOTA;
7186 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7187 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7188 	if (err)
7189 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7190 	iput(qf_inode);
7191 
7192 	return err;
7193 }
7194 
7195 /* Enable usage tracking for all quota types. */
7196 int ext4_enable_quotas(struct super_block *sb)
7197 {
7198 	int type, err = 0;
7199 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7200 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7201 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7202 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7203 	};
7204 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7205 		test_opt(sb, USRQUOTA),
7206 		test_opt(sb, GRPQUOTA),
7207 		test_opt(sb, PRJQUOTA),
7208 	};
7209 
7210 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7211 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7212 		if (qf_inums[type]) {
7213 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7214 				DQUOT_USAGE_ENABLED |
7215 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7216 			if (err) {
7217 				ext4_warning(sb,
7218 					"Failed to enable quota tracking "
7219 					"(type=%d, err=%d, ino=%lu). "
7220 					"Please run e2fsck to fix.", type,
7221 					err, qf_inums[type]);
7222 
7223 				ext4_quotas_off(sb, type);
7224 				return err;
7225 			}
7226 		}
7227 	}
7228 	return 0;
7229 }
7230 
7231 static int ext4_quota_off(struct super_block *sb, int type)
7232 {
7233 	struct inode *inode = sb_dqopt(sb)->files[type];
7234 	handle_t *handle;
7235 	int err;
7236 
7237 	/* Force all delayed allocation blocks to be allocated.
7238 	 * Caller already holds s_umount sem */
7239 	if (test_opt(sb, DELALLOC))
7240 		sync_filesystem(sb);
7241 
7242 	if (!inode || !igrab(inode))
7243 		goto out;
7244 
7245 	err = dquot_quota_off(sb, type);
7246 	if (err || ext4_has_feature_quota(sb))
7247 		goto out_put;
7248 	/*
7249 	 * When the filesystem was remounted read-only first, we cannot cleanup
7250 	 * inode flags here. Bad luck but people should be using QUOTA feature
7251 	 * these days anyway.
7252 	 */
7253 	if (sb_rdonly(sb))
7254 		goto out_put;
7255 
7256 	inode_lock(inode);
7257 	/*
7258 	 * Update modification times of quota files when userspace can
7259 	 * start looking at them. If we fail, we return success anyway since
7260 	 * this is not a hard failure and quotas are already disabled.
7261 	 */
7262 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7263 	if (IS_ERR(handle)) {
7264 		err = PTR_ERR(handle);
7265 		goto out_unlock;
7266 	}
7267 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7268 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7269 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
7270 	err = ext4_mark_inode_dirty(handle, inode);
7271 	ext4_journal_stop(handle);
7272 out_unlock:
7273 	inode_unlock(inode);
7274 out_put:
7275 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7276 	iput(inode);
7277 	return err;
7278 out:
7279 	return dquot_quota_off(sb, type);
7280 }
7281 
7282 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7283  * acquiring the locks... As quota files are never truncated and quota code
7284  * itself serializes the operations (and no one else should touch the files)
7285  * we don't have to be afraid of races */
7286 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7287 			       size_t len, loff_t off)
7288 {
7289 	struct inode *inode = sb_dqopt(sb)->files[type];
7290 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7291 	int offset = off & (sb->s_blocksize - 1);
7292 	int tocopy;
7293 	size_t toread;
7294 	struct buffer_head *bh;
7295 	loff_t i_size = i_size_read(inode);
7296 
7297 	if (off > i_size)
7298 		return 0;
7299 	if (off+len > i_size)
7300 		len = i_size-off;
7301 	toread = len;
7302 	while (toread > 0) {
7303 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7304 		bh = ext4_bread(NULL, inode, blk, 0);
7305 		if (IS_ERR(bh))
7306 			return PTR_ERR(bh);
7307 		if (!bh)	/* A hole? */
7308 			memset(data, 0, tocopy);
7309 		else
7310 			memcpy(data, bh->b_data+offset, tocopy);
7311 		brelse(bh);
7312 		offset = 0;
7313 		toread -= tocopy;
7314 		data += tocopy;
7315 		blk++;
7316 	}
7317 	return len;
7318 }
7319 
7320 /* Write to quotafile (we know the transaction is already started and has
7321  * enough credits) */
7322 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7323 				const char *data, size_t len, loff_t off)
7324 {
7325 	struct inode *inode = sb_dqopt(sb)->files[type];
7326 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7327 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7328 	int retries = 0;
7329 	struct buffer_head *bh;
7330 	handle_t *handle = journal_current_handle();
7331 
7332 	if (!handle) {
7333 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7334 			" cancelled because transaction is not started",
7335 			(unsigned long long)off, (unsigned long long)len);
7336 		return -EIO;
7337 	}
7338 	/*
7339 	 * Since we account only one data block in transaction credits,
7340 	 * then it is impossible to cross a block boundary.
7341 	 */
7342 	if (sb->s_blocksize - offset < len) {
7343 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7344 			" cancelled because not block aligned",
7345 			(unsigned long long)off, (unsigned long long)len);
7346 		return -EIO;
7347 	}
7348 
7349 	do {
7350 		bh = ext4_bread(handle, inode, blk,
7351 				EXT4_GET_BLOCKS_CREATE |
7352 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7353 	} while (PTR_ERR(bh) == -ENOSPC &&
7354 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7355 	if (IS_ERR(bh))
7356 		return PTR_ERR(bh);
7357 	if (!bh)
7358 		goto out;
7359 	BUFFER_TRACE(bh, "get write access");
7360 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7361 	if (err) {
7362 		brelse(bh);
7363 		return err;
7364 	}
7365 	lock_buffer(bh);
7366 	memcpy(bh->b_data+offset, data, len);
7367 	flush_dcache_folio(bh->b_folio);
7368 	unlock_buffer(bh);
7369 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7370 	brelse(bh);
7371 out:
7372 	if (inode->i_size < off + len) {
7373 		i_size_write(inode, off + len);
7374 		EXT4_I(inode)->i_disksize = inode->i_size;
7375 		err2 = ext4_mark_inode_dirty(handle, inode);
7376 		if (unlikely(err2 && !err))
7377 			err = err2;
7378 	}
7379 	return err ? err : len;
7380 }
7381 #endif
7382 
7383 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7384 static inline void register_as_ext2(void)
7385 {
7386 	int err = register_filesystem(&ext2_fs_type);
7387 	if (err)
7388 		printk(KERN_WARNING
7389 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7390 }
7391 
7392 static inline void unregister_as_ext2(void)
7393 {
7394 	unregister_filesystem(&ext2_fs_type);
7395 }
7396 
7397 static inline int ext2_feature_set_ok(struct super_block *sb)
7398 {
7399 	if (ext4_has_unknown_ext2_incompat_features(sb))
7400 		return 0;
7401 	if (sb_rdonly(sb))
7402 		return 1;
7403 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7404 		return 0;
7405 	return 1;
7406 }
7407 #else
7408 static inline void register_as_ext2(void) { }
7409 static inline void unregister_as_ext2(void) { }
7410 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7411 #endif
7412 
7413 static inline void register_as_ext3(void)
7414 {
7415 	int err = register_filesystem(&ext3_fs_type);
7416 	if (err)
7417 		printk(KERN_WARNING
7418 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7419 }
7420 
7421 static inline void unregister_as_ext3(void)
7422 {
7423 	unregister_filesystem(&ext3_fs_type);
7424 }
7425 
7426 static inline int ext3_feature_set_ok(struct super_block *sb)
7427 {
7428 	if (ext4_has_unknown_ext3_incompat_features(sb))
7429 		return 0;
7430 	if (!ext4_has_feature_journal(sb))
7431 		return 0;
7432 	if (sb_rdonly(sb))
7433 		return 1;
7434 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7435 		return 0;
7436 	return 1;
7437 }
7438 
7439 static void ext4_kill_sb(struct super_block *sb)
7440 {
7441 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7442 	struct file *bdev_file = sbi ? sbi->s_journal_bdev_file : NULL;
7443 
7444 	kill_block_super(sb);
7445 
7446 	if (bdev_file)
7447 		bdev_fput(bdev_file);
7448 }
7449 
7450 static struct file_system_type ext4_fs_type = {
7451 	.owner			= THIS_MODULE,
7452 	.name			= "ext4",
7453 	.init_fs_context	= ext4_init_fs_context,
7454 	.parameters		= ext4_param_specs,
7455 	.kill_sb		= ext4_kill_sb,
7456 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME |
7457 				  FS_LBS,
7458 };
7459 MODULE_ALIAS_FS("ext4");
7460 
7461 static int __init ext4_init_fs(void)
7462 {
7463 	int err;
7464 
7465 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7466 	ext4_li_info = NULL;
7467 
7468 	/* Build-time check for flags consistency */
7469 	ext4_check_flag_values();
7470 
7471 	err = ext4_init_es();
7472 	if (err)
7473 		return err;
7474 
7475 	err = ext4_init_pending();
7476 	if (err)
7477 		goto out7;
7478 
7479 	err = ext4_init_post_read_processing();
7480 	if (err)
7481 		goto out6;
7482 
7483 	err = ext4_init_pageio();
7484 	if (err)
7485 		goto out5;
7486 
7487 	err = ext4_init_system_zone();
7488 	if (err)
7489 		goto out4;
7490 
7491 	err = ext4_init_sysfs();
7492 	if (err)
7493 		goto out3;
7494 
7495 	err = ext4_init_mballoc();
7496 	if (err)
7497 		goto out2;
7498 	err = init_inodecache();
7499 	if (err)
7500 		goto out1;
7501 
7502 	err = ext4_fc_init_dentry_cache();
7503 	if (err)
7504 		goto out05;
7505 
7506 	register_as_ext3();
7507 	register_as_ext2();
7508 	err = register_filesystem(&ext4_fs_type);
7509 	if (err)
7510 		goto out;
7511 
7512 	return 0;
7513 out:
7514 	unregister_as_ext2();
7515 	unregister_as_ext3();
7516 	ext4_fc_destroy_dentry_cache();
7517 out05:
7518 	destroy_inodecache();
7519 out1:
7520 	ext4_exit_mballoc();
7521 out2:
7522 	ext4_exit_sysfs();
7523 out3:
7524 	ext4_exit_system_zone();
7525 out4:
7526 	ext4_exit_pageio();
7527 out5:
7528 	ext4_exit_post_read_processing();
7529 out6:
7530 	ext4_exit_pending();
7531 out7:
7532 	ext4_exit_es();
7533 
7534 	return err;
7535 }
7536 
7537 static void __exit ext4_exit_fs(void)
7538 {
7539 	ext4_destroy_lazyinit_thread();
7540 	unregister_as_ext2();
7541 	unregister_as_ext3();
7542 	unregister_filesystem(&ext4_fs_type);
7543 	ext4_fc_destroy_dentry_cache();
7544 	destroy_inodecache();
7545 	ext4_exit_mballoc();
7546 	ext4_exit_sysfs();
7547 	ext4_exit_system_zone();
7548 	ext4_exit_pageio();
7549 	ext4_exit_post_read_processing();
7550 	ext4_exit_es();
7551 	ext4_exit_pending();
7552 }
7553 
7554 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7555 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7556 MODULE_LICENSE("GPL");
7557 module_init(ext4_init_fs)
7558 module_exit(ext4_exit_fs)
7559