xref: /linux/fs/ext4/super.c (revision a436a0b847c0fef9ead14f99bc03d8adbf66f15b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 #include <linux/fserror.h>
52 
53 #include "ext4.h"
54 #include "ext4_extents.h"	/* Needed for trace points definition */
55 #include "ext4_jbd2.h"
56 #include "xattr.h"
57 #include "acl.h"
58 #include "mballoc.h"
59 #include "fsmap.h"
60 
61 #define CREATE_TRACE_POINTS
62 #include <trace/events/ext4.h>
63 
64 static struct ext4_lazy_init *ext4_li_info;
65 static DEFINE_MUTEX(ext4_li_mtx);
66 static struct ratelimit_state ext4_mount_msg_ratelimit;
67 
68 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
69 			     unsigned long journal_devnum);
70 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
71 static void ext4_update_super(struct super_block *sb);
72 static int ext4_commit_super(struct super_block *sb);
73 static int ext4_mark_recovery_complete(struct super_block *sb,
74 					struct ext4_super_block *es);
75 static int ext4_clear_journal_err(struct super_block *sb,
76 				  struct ext4_super_block *es);
77 static int ext4_sync_fs(struct super_block *sb, int wait);
78 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
79 static int ext4_unfreeze(struct super_block *sb);
80 static int ext4_freeze(struct super_block *sb);
81 static inline int ext2_feature_set_ok(struct super_block *sb);
82 static inline int ext3_feature_set_ok(struct super_block *sb);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static void ext4_kill_sb(struct super_block *sb);
97 static const struct fs_parameter_spec ext4_param_specs[];
98 
99 /*
100  * Lock ordering
101  *
102  * page fault path:
103  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
104  *   -> page lock -> i_data_sem (rw)
105  *
106  * buffered write path:
107  * sb_start_write -> i_mutex -> mmap_lock
108  * sb_start_write -> i_mutex -> transaction start -> page lock ->
109  *   i_data_sem (rw)
110  *
111  * truncate:
112  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
113  *   page lock
114  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
115  *   i_data_sem (rw)
116  *
117  * direct IO:
118  * sb_start_write -> i_mutex -> mmap_lock
119  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
120  *
121  * writepages:
122  * transaction start -> page lock(s) -> i_data_sem (rw)
123  */
124 
125 static const struct fs_context_operations ext4_context_ops = {
126 	.parse_param	= ext4_parse_param,
127 	.get_tree	= ext4_get_tree,
128 	.reconfigure	= ext4_reconfigure,
129 	.free		= ext4_fc_free,
130 };
131 
132 
133 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
134 static struct file_system_type ext2_fs_type = {
135 	.owner			= THIS_MODULE,
136 	.name			= "ext2",
137 	.init_fs_context	= ext4_init_fs_context,
138 	.parameters		= ext4_param_specs,
139 	.kill_sb		= ext4_kill_sb,
140 	.fs_flags		= FS_REQUIRES_DEV,
141 };
142 MODULE_ALIAS_FS("ext2");
143 MODULE_ALIAS("ext2");
144 #define IS_EXT2_SB(sb) ((sb)->s_type == &ext2_fs_type)
145 #else
146 #define IS_EXT2_SB(sb) (0)
147 #endif
148 
149 
150 static struct file_system_type ext3_fs_type = {
151 	.owner			= THIS_MODULE,
152 	.name			= "ext3",
153 	.init_fs_context	= ext4_init_fs_context,
154 	.parameters		= ext4_param_specs,
155 	.kill_sb		= ext4_kill_sb,
156 	.fs_flags		= FS_REQUIRES_DEV,
157 };
158 MODULE_ALIAS_FS("ext3");
159 MODULE_ALIAS("ext3");
160 #define IS_EXT3_SB(sb) ((sb)->s_type == &ext3_fs_type)
161 
162 
163 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
164 				  bh_end_io_t *end_io, bool simu_fail)
165 {
166 	if (simu_fail) {
167 		clear_buffer_uptodate(bh);
168 		unlock_buffer(bh);
169 		return;
170 	}
171 
172 	/*
173 	 * buffer's verified bit is no longer valid after reading from
174 	 * disk again due to write out error, clear it to make sure we
175 	 * recheck the buffer contents.
176 	 */
177 	clear_buffer_verified(bh);
178 
179 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
180 	get_bh(bh);
181 	submit_bh(REQ_OP_READ | op_flags, bh);
182 }
183 
184 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
185 			 bh_end_io_t *end_io, bool simu_fail)
186 {
187 	BUG_ON(!buffer_locked(bh));
188 
189 	if (ext4_buffer_uptodate(bh)) {
190 		unlock_buffer(bh);
191 		return;
192 	}
193 	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
194 }
195 
196 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
197 		 bh_end_io_t *end_io, bool simu_fail)
198 {
199 	BUG_ON(!buffer_locked(bh));
200 
201 	if (ext4_buffer_uptodate(bh)) {
202 		unlock_buffer(bh);
203 		return 0;
204 	}
205 
206 	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
207 
208 	wait_on_buffer(bh);
209 	if (buffer_uptodate(bh))
210 		return 0;
211 	return -EIO;
212 }
213 
214 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
215 {
216 	lock_buffer(bh);
217 	if (!wait) {
218 		ext4_read_bh_nowait(bh, op_flags, NULL, false);
219 		return 0;
220 	}
221 	return ext4_read_bh(bh, op_flags, NULL, false);
222 }
223 
224 /*
225  * This works like __bread_gfp() except it uses ERR_PTR for error
226  * returns.  Currently with sb_bread it's impossible to distinguish
227  * between ENOMEM and EIO situations (since both result in a NULL
228  * return.
229  */
230 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
231 					       sector_t block,
232 					       blk_opf_t op_flags, gfp_t gfp)
233 {
234 	struct buffer_head *bh;
235 	int ret;
236 
237 	bh = sb_getblk_gfp(sb, block, gfp);
238 	if (bh == NULL)
239 		return ERR_PTR(-ENOMEM);
240 	if (ext4_buffer_uptodate(bh))
241 		return bh;
242 
243 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
244 	if (ret) {
245 		put_bh(bh);
246 		return ERR_PTR(ret);
247 	}
248 	return bh;
249 }
250 
251 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
252 				   blk_opf_t op_flags)
253 {
254 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
255 			~__GFP_FS) | __GFP_MOVABLE;
256 
257 	return __ext4_sb_bread_gfp(sb, block, op_flags, gfp);
258 }
259 
260 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
261 					    sector_t block)
262 {
263 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
264 			~__GFP_FS);
265 
266 	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
267 }
268 
269 struct buffer_head *ext4_sb_bread_nofail(struct super_block *sb,
270 					 sector_t block)
271 {
272 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
273 			~__GFP_FS) | __GFP_MOVABLE | __GFP_NOFAIL;
274 
275 	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
276 }
277 
278 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
279 {
280 	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
281 			sb->s_blocksize, GFP_NOWAIT);
282 
283 	if (likely(bh)) {
284 		if (trylock_buffer(bh))
285 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL, false);
286 		brelse(bh);
287 	}
288 }
289 
290 static int ext4_verify_csum_type(struct super_block *sb,
291 				 struct ext4_super_block *es)
292 {
293 	if (!ext4_has_feature_metadata_csum(sb))
294 		return 1;
295 
296 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
297 }
298 
299 __le32 ext4_superblock_csum(struct ext4_super_block *es)
300 {
301 	int offset = offsetof(struct ext4_super_block, s_checksum);
302 	__u32 csum;
303 
304 	csum = ext4_chksum(~0, (char *)es, offset);
305 
306 	return cpu_to_le32(csum);
307 }
308 
309 static int ext4_superblock_csum_verify(struct super_block *sb,
310 				       struct ext4_super_block *es)
311 {
312 	if (!ext4_has_feature_metadata_csum(sb))
313 		return 1;
314 
315 	return es->s_checksum == ext4_superblock_csum(es);
316 }
317 
318 void ext4_superblock_csum_set(struct super_block *sb)
319 {
320 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
321 
322 	if (!ext4_has_feature_metadata_csum(sb))
323 		return;
324 
325 	es->s_checksum = ext4_superblock_csum(es);
326 }
327 
328 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
329 			       struct ext4_group_desc *bg)
330 {
331 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
332 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
333 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
334 }
335 
336 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
337 			       struct ext4_group_desc *bg)
338 {
339 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
340 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
341 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
342 }
343 
344 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
345 			      struct ext4_group_desc *bg)
346 {
347 	return le32_to_cpu(bg->bg_inode_table_lo) |
348 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
349 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
350 }
351 
352 __u32 ext4_free_group_clusters(struct super_block *sb,
353 			       struct ext4_group_desc *bg)
354 {
355 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
356 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
357 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
358 }
359 
360 __u32 ext4_free_inodes_count(struct super_block *sb,
361 			      struct ext4_group_desc *bg)
362 {
363 	return le16_to_cpu(READ_ONCE(bg->bg_free_inodes_count_lo)) |
364 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
365 		 (__u32)le16_to_cpu(READ_ONCE(bg->bg_free_inodes_count_hi)) << 16 : 0);
366 }
367 
368 __u32 ext4_used_dirs_count(struct super_block *sb,
369 			      struct ext4_group_desc *bg)
370 {
371 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
372 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
373 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
374 }
375 
376 __u32 ext4_itable_unused_count(struct super_block *sb,
377 			      struct ext4_group_desc *bg)
378 {
379 	return le16_to_cpu(bg->bg_itable_unused_lo) |
380 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
381 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
382 }
383 
384 void ext4_block_bitmap_set(struct super_block *sb,
385 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
386 {
387 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
388 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
389 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
390 }
391 
392 void ext4_inode_bitmap_set(struct super_block *sb,
393 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
394 {
395 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
396 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
397 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
398 }
399 
400 void ext4_inode_table_set(struct super_block *sb,
401 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
402 {
403 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
404 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
405 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
406 }
407 
408 void ext4_free_group_clusters_set(struct super_block *sb,
409 				  struct ext4_group_desc *bg, __u32 count)
410 {
411 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
412 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
413 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
414 }
415 
416 void ext4_free_inodes_set(struct super_block *sb,
417 			  struct ext4_group_desc *bg, __u32 count)
418 {
419 	WRITE_ONCE(bg->bg_free_inodes_count_lo, cpu_to_le16((__u16)count));
420 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
421 		WRITE_ONCE(bg->bg_free_inodes_count_hi, cpu_to_le16(count >> 16));
422 }
423 
424 void ext4_used_dirs_set(struct super_block *sb,
425 			  struct ext4_group_desc *bg, __u32 count)
426 {
427 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
428 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
429 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
430 }
431 
432 void ext4_itable_unused_set(struct super_block *sb,
433 			  struct ext4_group_desc *bg, __u32 count)
434 {
435 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
436 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
437 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
438 }
439 
440 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
441 {
442 	now = clamp_val(now, 0, (1ull << 40) - 1);
443 
444 	*lo = cpu_to_le32(lower_32_bits(now));
445 	*hi = upper_32_bits(now);
446 }
447 
448 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
449 {
450 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
451 }
452 #define ext4_update_tstamp(es, tstamp) \
453 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
454 			     ktime_get_real_seconds())
455 #define ext4_get_tstamp(es, tstamp) \
456 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
457 
458 /*
459  * The ext4_maybe_update_superblock() function checks and updates the
460  * superblock if needed.
461  *
462  * This function is designed to update the on-disk superblock only under
463  * certain conditions to prevent excessive disk writes and unnecessary
464  * waking of the disk from sleep. The superblock will be updated if:
465  * 1. More than sbi->s_sb_update_sec (def: 1 hour) has passed since the last
466  *    superblock update
467  * 2. More than sbi->s_sb_update_kb (def: 16MB) kbs have been written since the
468  *    last superblock update.
469  *
470  * @sb: The superblock
471  */
472 static void ext4_maybe_update_superblock(struct super_block *sb)
473 {
474 	struct ext4_sb_info *sbi = EXT4_SB(sb);
475 	struct ext4_super_block *es = sbi->s_es;
476 	journal_t *journal = sbi->s_journal;
477 	time64_t now;
478 	__u64 last_update;
479 	__u64 lifetime_write_kbytes;
480 	__u64 diff_size;
481 
482 	if (ext4_emergency_state(sb) || sb_rdonly(sb) ||
483 	    !(sb->s_flags & SB_ACTIVE) || !journal ||
484 	    journal->j_flags & JBD2_UNMOUNT)
485 		return;
486 
487 	now = ktime_get_real_seconds();
488 	last_update = ext4_get_tstamp(es, s_wtime);
489 
490 	if (likely(now - last_update < sbi->s_sb_update_sec))
491 		return;
492 
493 	lifetime_write_kbytes = sbi->s_kbytes_written +
494 		((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
495 		  sbi->s_sectors_written_start) >> 1);
496 
497 	/* Get the number of kilobytes not written to disk to account
498 	 * for statistics and compare with a multiple of 16 MB. This
499 	 * is used to determine when the next superblock commit should
500 	 * occur (i.e. not more often than once per 16MB if there was
501 	 * less written in an hour).
502 	 */
503 	diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written);
504 
505 	if (diff_size > sbi->s_sb_update_kb)
506 		schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
507 }
508 
509 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
510 {
511 	struct super_block		*sb = journal->j_private;
512 
513 	BUG_ON(txn->t_state == T_FINISHED);
514 
515 	ext4_process_freed_data(sb, txn->t_tid);
516 	ext4_maybe_update_superblock(sb);
517 }
518 
519 static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode,
520 		struct folio *folio)
521 {
522 	struct buffer_head *bh, *head;
523 	struct journal_head *jh;
524 	transaction_t *trans = READ_ONCE(jinode->i_transaction);
525 
526 	bh = head = folio_buffers(folio);
527 	do {
528 		/*
529 		 * We have to redirty a page in these cases:
530 		 * 1) If buffer is dirty, it means the page was dirty because it
531 		 * contains a buffer that needs checkpointing. So the dirty bit
532 		 * needs to be preserved so that checkpointing writes the buffer
533 		 * properly.
534 		 * 2) If buffer is not part of the committing transaction
535 		 * (we may have just accidentally come across this buffer because
536 		 * inode range tracking is not exact) or if the currently running
537 		 * transaction already contains this buffer as well, dirty bit
538 		 * needs to be preserved so that the buffer gets writeprotected
539 		 * properly on running transaction's commit.
540 		 */
541 		jh = bh2jh(bh);
542 		if (buffer_dirty(bh) ||
543 		    (jh && (jh->b_transaction != trans ||
544 			    jh->b_next_transaction)))
545 			return true;
546 	} while ((bh = bh->b_this_page) != head);
547 
548 	return false;
549 }
550 
551 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
552 {
553 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
554 	loff_t range_start, range_end;
555 	struct writeback_control wbc = {
556 		.sync_mode = WB_SYNC_ALL,
557 		.nr_to_write = LONG_MAX,
558 	};
559 	struct folio *folio = NULL;
560 	int error;
561 
562 	if (!jbd2_jinode_get_dirty_range(jinode, &range_start, &range_end))
563 		return 0;
564 
565 	wbc.range_start = range_start;
566 	wbc.range_end = range_end;
567 
568 	/*
569 	 * writeback_iter() already checks for dirty pages and calls
570 	 * folio_clear_dirty_for_io(), which we want to write protect the
571 	 * folios.
572 	 *
573 	 * However, we may have to redirty a folio sometimes.
574 	 */
575 	while ((folio = writeback_iter(mapping, &wbc, folio, &error))) {
576 		if (ext4_journalled_writepage_needs_redirty(jinode, folio))
577 			folio_redirty_for_writepage(&wbc, folio);
578 		folio_unlock(folio);
579 	}
580 
581 	return error;
582 }
583 
584 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
585 {
586 	int ret;
587 
588 	if (ext4_should_journal_data(jinode->i_vfs_inode))
589 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
590 	else
591 		ret = ext4_normal_submit_inode_data_buffers(jinode);
592 	return ret;
593 }
594 
595 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
596 {
597 	int ret = 0;
598 
599 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
600 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
601 
602 	return ret;
603 }
604 
605 static bool system_going_down(void)
606 {
607 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
608 		|| system_state == SYSTEM_RESTART;
609 }
610 
611 struct ext4_err_translation {
612 	int code;
613 	int errno;
614 };
615 
616 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
617 
618 static struct ext4_err_translation err_translation[] = {
619 	EXT4_ERR_TRANSLATE(EIO),
620 	EXT4_ERR_TRANSLATE(ENOMEM),
621 	EXT4_ERR_TRANSLATE(EFSBADCRC),
622 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
623 	EXT4_ERR_TRANSLATE(ENOSPC),
624 	EXT4_ERR_TRANSLATE(ENOKEY),
625 	EXT4_ERR_TRANSLATE(EROFS),
626 	EXT4_ERR_TRANSLATE(EFBIG),
627 	EXT4_ERR_TRANSLATE(EEXIST),
628 	EXT4_ERR_TRANSLATE(ERANGE),
629 	EXT4_ERR_TRANSLATE(EOVERFLOW),
630 	EXT4_ERR_TRANSLATE(EBUSY),
631 	EXT4_ERR_TRANSLATE(ENOTDIR),
632 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
633 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
634 	EXT4_ERR_TRANSLATE(EFAULT),
635 };
636 
637 static int ext4_errno_to_code(int errno)
638 {
639 	int i;
640 
641 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
642 		if (err_translation[i].errno == errno)
643 			return err_translation[i].code;
644 	return EXT4_ERR_UNKNOWN;
645 }
646 
647 static void save_error_info(struct super_block *sb, int error,
648 			    __u32 ino, __u64 block,
649 			    const char *func, unsigned int line)
650 {
651 	struct ext4_sb_info *sbi = EXT4_SB(sb);
652 
653 	/* We default to EFSCORRUPTED error... */
654 	if (error == 0)
655 		error = EFSCORRUPTED;
656 
657 	spin_lock(&sbi->s_error_lock);
658 	sbi->s_add_error_count++;
659 	sbi->s_last_error_code = error;
660 	sbi->s_last_error_line = line;
661 	sbi->s_last_error_ino = ino;
662 	sbi->s_last_error_block = block;
663 	sbi->s_last_error_func = func;
664 	sbi->s_last_error_time = ktime_get_real_seconds();
665 	if (!sbi->s_first_error_time) {
666 		sbi->s_first_error_code = error;
667 		sbi->s_first_error_line = line;
668 		sbi->s_first_error_ino = ino;
669 		sbi->s_first_error_block = block;
670 		sbi->s_first_error_func = func;
671 		sbi->s_first_error_time = sbi->s_last_error_time;
672 	}
673 	spin_unlock(&sbi->s_error_lock);
674 }
675 
676 /* Deal with the reporting of failure conditions on a filesystem such as
677  * inconsistencies detected or read IO failures.
678  *
679  * On ext2, we can store the error state of the filesystem in the
680  * superblock.  That is not possible on ext4, because we may have other
681  * write ordering constraints on the superblock which prevent us from
682  * writing it out straight away; and given that the journal is about to
683  * be aborted, we can't rely on the current, or future, transactions to
684  * write out the superblock safely.
685  *
686  * We'll just use the jbd2_journal_abort() error code to record an error in
687  * the journal instead.  On recovery, the journal will complain about
688  * that error until we've noted it down and cleared it.
689  *
690  * If force_ro is set, we unconditionally force the filesystem into an
691  * ABORT|READONLY state, unless the error response on the fs has been set to
692  * panic in which case we take the easy way out and panic immediately. This is
693  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
694  * at a critical moment in log management.
695  */
696 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
697 			      __u32 ino, __u64 block,
698 			      const char *func, unsigned int line)
699 {
700 	journal_t *journal = EXT4_SB(sb)->s_journal;
701 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
702 
703 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
704 	if (test_opt(sb, WARN_ON_ERROR))
705 		WARN_ON_ONCE(1);
706 
707 	if (!continue_fs && !ext4_emergency_ro(sb) && journal)
708 		jbd2_journal_abort(journal, -error);
709 
710 	if (!bdev_read_only(sb->s_bdev)) {
711 		save_error_info(sb, error, ino, block, func, line);
712 		/*
713 		 * In case the fs should keep running, we need to writeout
714 		 * superblock through the journal. Due to lock ordering
715 		 * constraints, it may not be safe to do it right here so we
716 		 * defer superblock flushing to a workqueue. We just need to be
717 		 * careful when the journal is already shutting down. If we get
718 		 * here in that case, just update the sb directly as the last
719 		 * transaction won't commit anyway.
720 		 */
721 		if (continue_fs && journal &&
722 		    !ext4_test_mount_flag(sb, EXT4_MF_JOURNAL_DESTROY))
723 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
724 		else
725 			ext4_commit_super(sb);
726 	}
727 
728 	/*
729 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
730 	 * could panic during 'reboot -f' as the underlying device got already
731 	 * disabled.
732 	 */
733 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
734 		panic("EXT4-fs (device %s): panic forced after error\n",
735 			sb->s_id);
736 	}
737 
738 	if (ext4_emergency_ro(sb) || continue_fs)
739 		return;
740 
741 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
742 	/*
743 	 * We don't set SB_RDONLY because that requires sb->s_umount
744 	 * semaphore and setting it without proper remount procedure is
745 	 * confusing code such as freeze_super() leading to deadlocks
746 	 * and other problems.
747 	 */
748 	set_bit(EXT4_FLAGS_EMERGENCY_RO, &EXT4_SB(sb)->s_ext4_flags);
749 }
750 
751 static void update_super_work(struct work_struct *work)
752 {
753 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
754 						s_sb_upd_work);
755 	journal_t *journal = sbi->s_journal;
756 	handle_t *handle;
757 
758 	/*
759 	 * If the journal is still running, we have to write out superblock
760 	 * through the journal to avoid collisions of other journalled sb
761 	 * updates.
762 	 *
763 	 * We use directly jbd2 functions here to avoid recursing back into
764 	 * ext4 error handling code during handling of previous errors.
765 	 */
766 	if (!ext4_emergency_state(sbi->s_sb) &&
767 	    !sb_rdonly(sbi->s_sb) && journal) {
768 		struct buffer_head *sbh = sbi->s_sbh;
769 		bool call_notify_err = false;
770 
771 		handle = jbd2_journal_start(journal, 1);
772 		if (IS_ERR(handle))
773 			goto write_directly;
774 		if (jbd2_journal_get_write_access(handle, sbh)) {
775 			jbd2_journal_stop(handle);
776 			goto write_directly;
777 		}
778 
779 		if (sbi->s_add_error_count > 0)
780 			call_notify_err = true;
781 
782 		ext4_update_super(sbi->s_sb);
783 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
784 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
785 				 "superblock detected");
786 			clear_buffer_write_io_error(sbh);
787 			set_buffer_uptodate(sbh);
788 		}
789 
790 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
791 			jbd2_journal_stop(handle);
792 			goto write_directly;
793 		}
794 		jbd2_journal_stop(handle);
795 
796 		if (call_notify_err)
797 			ext4_notify_error_sysfs(sbi);
798 
799 		return;
800 	}
801 write_directly:
802 	/*
803 	 * Write through journal failed. Write sb directly to get error info
804 	 * out and hope for the best.
805 	 */
806 	ext4_commit_super(sbi->s_sb);
807 	ext4_notify_error_sysfs(sbi);
808 }
809 
810 #define ext4_error_ratelimit(sb)					\
811 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
812 			     "EXT4-fs error")
813 
814 void __ext4_error(struct super_block *sb, const char *function,
815 		  unsigned int line, bool force_ro, int error, __u64 block,
816 		  const char *fmt, ...)
817 {
818 	struct va_format vaf;
819 	va_list args;
820 
821 	if (unlikely(ext4_emergency_state(sb)))
822 		return;
823 
824 	trace_ext4_error(sb, function, line);
825 	if (ext4_error_ratelimit(sb)) {
826 		va_start(args, fmt);
827 		vaf.fmt = fmt;
828 		vaf.va = &args;
829 		printk(KERN_CRIT
830 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
831 		       sb->s_id, function, line, current->comm, &vaf);
832 		va_end(args);
833 	}
834 	fserror_report_metadata(sb, error ? -abs(error) : -EFSCORRUPTED,
835 				GFP_ATOMIC);
836 
837 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
838 }
839 
840 void __ext4_error_inode(struct inode *inode, const char *function,
841 			unsigned int line, ext4_fsblk_t block, int error,
842 			const char *fmt, ...)
843 {
844 	va_list args;
845 	struct va_format vaf;
846 
847 	if (unlikely(ext4_emergency_state(inode->i_sb)))
848 		return;
849 
850 	trace_ext4_error(inode->i_sb, function, line);
851 	if (ext4_error_ratelimit(inode->i_sb)) {
852 		va_start(args, fmt);
853 		vaf.fmt = fmt;
854 		vaf.va = &args;
855 		if (block)
856 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
857 			       "inode #%llu: block %llu: comm %s: %pV\n",
858 			       inode->i_sb->s_id, function, line, inode->i_ino,
859 			       block, current->comm, &vaf);
860 		else
861 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
862 			       "inode #%llu: comm %s: %pV\n",
863 			       inode->i_sb->s_id, function, line, inode->i_ino,
864 			       current->comm, &vaf);
865 		va_end(args);
866 	}
867 	fserror_report_file_metadata(inode,
868 				     error ? -abs(error) : -EFSCORRUPTED,
869 				     GFP_ATOMIC);
870 
871 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
872 			  function, line);
873 }
874 
875 void __ext4_error_file(struct file *file, const char *function,
876 		       unsigned int line, ext4_fsblk_t block,
877 		       const char *fmt, ...)
878 {
879 	va_list args;
880 	struct va_format vaf;
881 	struct inode *inode = file_inode(file);
882 	char pathname[80], *path;
883 
884 	if (unlikely(ext4_emergency_state(inode->i_sb)))
885 		return;
886 
887 	trace_ext4_error(inode->i_sb, function, line);
888 	if (ext4_error_ratelimit(inode->i_sb)) {
889 		path = file_path(file, pathname, sizeof(pathname));
890 		if (IS_ERR(path))
891 			path = "(unknown)";
892 		va_start(args, fmt);
893 		vaf.fmt = fmt;
894 		vaf.va = &args;
895 		if (block)
896 			printk(KERN_CRIT
897 			       "EXT4-fs error (device %s): %s:%d: inode #%llu: "
898 			       "block %llu: comm %s: path %s: %pV\n",
899 			       inode->i_sb->s_id, function, line, inode->i_ino,
900 			       block, current->comm, path, &vaf);
901 		else
902 			printk(KERN_CRIT
903 			       "EXT4-fs error (device %s): %s:%d: inode #%llu: "
904 			       "comm %s: path %s: %pV\n",
905 			       inode->i_sb->s_id, function, line, inode->i_ino,
906 			       current->comm, path, &vaf);
907 		va_end(args);
908 	}
909 	fserror_report_file_metadata(inode, -EFSCORRUPTED, GFP_ATOMIC);
910 
911 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
912 			  function, line);
913 }
914 
915 const char *ext4_decode_error(struct super_block *sb, int errno,
916 			      char nbuf[16])
917 {
918 	char *errstr = NULL;
919 
920 	switch (errno) {
921 	case -EFSCORRUPTED:
922 		errstr = "Corrupt filesystem";
923 		break;
924 	case -EFSBADCRC:
925 		errstr = "Filesystem failed CRC";
926 		break;
927 	case -EIO:
928 		errstr = "IO failure";
929 		break;
930 	case -ENOMEM:
931 		errstr = "Out of memory";
932 		break;
933 	case -EROFS:
934 		if (!sb || (EXT4_SB(sb)->s_journal &&
935 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
936 			errstr = "Journal has aborted";
937 		else
938 			errstr = "Readonly filesystem";
939 		break;
940 	default:
941 		/* If the caller passed in an extra buffer for unknown
942 		 * errors, textualise them now.  Else we just return
943 		 * NULL. */
944 		if (nbuf) {
945 			/* Check for truncated error codes... */
946 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
947 				errstr = nbuf;
948 		}
949 		break;
950 	}
951 
952 	return errstr;
953 }
954 
955 /* __ext4_std_error decodes expected errors from journaling functions
956  * automatically and invokes the appropriate error response.  */
957 
958 void __ext4_std_error(struct super_block *sb, const char *function,
959 		      unsigned int line, int errno)
960 {
961 	char nbuf[16];
962 	const char *errstr;
963 
964 	if (unlikely(ext4_emergency_state(sb)))
965 		return;
966 
967 	/* Special case: if the error is EROFS, and we're not already
968 	 * inside a transaction, then there's really no point in logging
969 	 * an error. */
970 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
971 		return;
972 
973 	if (ext4_error_ratelimit(sb)) {
974 		errstr = ext4_decode_error(sb, errno, nbuf);
975 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
976 		       sb->s_id, function, line, errstr);
977 	}
978 	fserror_report_metadata(sb, errno ? -abs(errno) : -EFSCORRUPTED,
979 				GFP_ATOMIC);
980 
981 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
982 }
983 
984 void __ext4_msg(struct super_block *sb,
985 		const char *prefix, const char *fmt, ...)
986 {
987 	struct va_format vaf;
988 	va_list args;
989 
990 	if (sb) {
991 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
992 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
993 				  "EXT4-fs"))
994 			return;
995 	}
996 
997 	va_start(args, fmt);
998 	vaf.fmt = fmt;
999 	vaf.va = &args;
1000 	if (sb)
1001 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
1002 	else
1003 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
1004 	va_end(args);
1005 }
1006 
1007 static int ext4_warning_ratelimit(struct super_block *sb)
1008 {
1009 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
1010 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1011 			    "EXT4-fs warning");
1012 }
1013 
1014 void __ext4_warning(struct super_block *sb, const char *function,
1015 		    unsigned int line, const char *fmt, ...)
1016 {
1017 	struct va_format vaf;
1018 	va_list args;
1019 
1020 	if (!ext4_warning_ratelimit(sb))
1021 		return;
1022 
1023 	va_start(args, fmt);
1024 	vaf.fmt = fmt;
1025 	vaf.va = &args;
1026 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1027 	       sb->s_id, function, line, &vaf);
1028 	va_end(args);
1029 }
1030 
1031 void __ext4_warning_inode(const struct inode *inode, const char *function,
1032 			  unsigned int line, const char *fmt, ...)
1033 {
1034 	struct va_format vaf;
1035 	va_list args;
1036 
1037 	if (!ext4_warning_ratelimit(inode->i_sb))
1038 		return;
1039 
1040 	va_start(args, fmt);
1041 	vaf.fmt = fmt;
1042 	vaf.va = &args;
1043 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1044 	       "inode #%llu: comm %s: %pV\n", inode->i_sb->s_id,
1045 	       function, line, inode->i_ino, current->comm, &vaf);
1046 	va_end(args);
1047 }
1048 
1049 void __ext4_grp_locked_error(const char *function, unsigned int line,
1050 			     struct super_block *sb, ext4_group_t grp,
1051 			     u64 ino, ext4_fsblk_t block,
1052 			     const char *fmt, ...)
1053 __releases(bitlock)
1054 __acquires(bitlock)
1055 {
1056 	struct va_format vaf;
1057 	va_list args;
1058 
1059 	if (unlikely(ext4_emergency_state(sb)))
1060 		return;
1061 
1062 	trace_ext4_error(sb, function, line);
1063 	if (ext4_error_ratelimit(sb)) {
1064 		va_start(args, fmt);
1065 		vaf.fmt = fmt;
1066 		vaf.va = &args;
1067 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1068 		       sb->s_id, function, line, grp);
1069 		if (ino)
1070 			printk(KERN_CONT "inode %llu: ", ino);
1071 		if (block)
1072 			printk(KERN_CONT "block %llu:",
1073 			       (unsigned long long) block);
1074 		printk(KERN_CONT "%pV\n", &vaf);
1075 		va_end(args);
1076 	}
1077 
1078 	if (test_opt(sb, ERRORS_CONT)) {
1079 		if (test_opt(sb, WARN_ON_ERROR))
1080 			WARN_ON_ONCE(1);
1081 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1082 		if (!bdev_read_only(sb->s_bdev)) {
1083 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1084 					line);
1085 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1086 		}
1087 		return;
1088 	}
1089 	ext4_unlock_group(sb, grp);
1090 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1091 	/*
1092 	 * We only get here in the ERRORS_RO case; relocking the group
1093 	 * may be dangerous, but nothing bad will happen since the
1094 	 * filesystem will have already been marked read/only and the
1095 	 * journal has been aborted.  We return 1 as a hint to callers
1096 	 * who might what to use the return value from
1097 	 * ext4_grp_locked_error() to distinguish between the
1098 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1099 	 * aggressively from the ext4 function in question, with a
1100 	 * more appropriate error code.
1101 	 */
1102 	ext4_lock_group(sb, grp);
1103 	return;
1104 }
1105 
1106 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1107 				     ext4_group_t group,
1108 				     unsigned int flags)
1109 {
1110 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1111 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1112 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1113 	int ret;
1114 
1115 	if (!grp || !gdp)
1116 		return;
1117 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1118 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1119 					    &grp->bb_state);
1120 		if (!ret)
1121 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1122 					   grp->bb_free);
1123 	}
1124 
1125 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1126 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1127 					    &grp->bb_state);
1128 		if (!ret && gdp) {
1129 			int count;
1130 
1131 			count = ext4_free_inodes_count(sb, gdp);
1132 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1133 					   count);
1134 		}
1135 	}
1136 }
1137 
1138 void ext4_update_dynamic_rev(struct super_block *sb)
1139 {
1140 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1141 
1142 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1143 		return;
1144 
1145 	ext4_warning(sb,
1146 		     "updating to rev %d because of new feature flag, "
1147 		     "running e2fsck is recommended",
1148 		     EXT4_DYNAMIC_REV);
1149 
1150 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1151 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1152 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1153 	/* leave es->s_feature_*compat flags alone */
1154 	/* es->s_uuid will be set by e2fsck if empty */
1155 
1156 	/*
1157 	 * The rest of the superblock fields should be zero, and if not it
1158 	 * means they are likely already in use, so leave them alone.  We
1159 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1160 	 */
1161 }
1162 
1163 static inline struct inode *orphan_list_entry(struct list_head *l)
1164 {
1165 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1166 }
1167 
1168 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1169 {
1170 	struct list_head *l;
1171 
1172 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1173 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1174 
1175 	printk(KERN_ERR "sb_info orphan list:\n");
1176 	list_for_each(l, &sbi->s_orphan) {
1177 		struct inode *inode = orphan_list_entry(l);
1178 		printk(KERN_ERR "  "
1179 		       "inode %s:%llu at %p: mode %o, nlink %d, next %d\n",
1180 		       inode->i_sb->s_id, inode->i_ino, inode,
1181 		       inode->i_mode, inode->i_nlink,
1182 		       NEXT_ORPHAN(inode));
1183 	}
1184 }
1185 
1186 #ifdef CONFIG_QUOTA
1187 static int ext4_quota_off(struct super_block *sb, int type);
1188 
1189 static inline void ext4_quotas_off(struct super_block *sb, int type)
1190 {
1191 	BUG_ON(type > EXT4_MAXQUOTAS);
1192 
1193 	/* Use our quota_off function to clear inode flags etc. */
1194 	for (type--; type >= 0; type--)
1195 		ext4_quota_off(sb, type);
1196 }
1197 
1198 /*
1199  * This is a helper function which is used in the mount/remount
1200  * codepaths (which holds s_umount) to fetch the quota file name.
1201  */
1202 static inline char *get_qf_name(struct super_block *sb,
1203 				struct ext4_sb_info *sbi,
1204 				int type)
1205 {
1206 	return rcu_dereference_protected(sbi->s_qf_names[type],
1207 					 lockdep_is_held(&sb->s_umount));
1208 }
1209 #else
1210 static inline void ext4_quotas_off(struct super_block *sb, int type)
1211 {
1212 }
1213 #endif
1214 
1215 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1216 {
1217 	ext4_fsblk_t block;
1218 	int err;
1219 
1220 	block = ext4_count_free_clusters(sbi->s_sb);
1221 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1222 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1223 				  GFP_KERNEL);
1224 	if (!err) {
1225 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1226 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1227 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1228 					  GFP_KERNEL);
1229 	}
1230 	if (!err)
1231 		err = percpu_counter_init(&sbi->s_dirs_counter,
1232 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1233 	if (!err)
1234 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1235 					  GFP_KERNEL);
1236 	if (!err)
1237 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1238 					  GFP_KERNEL);
1239 	if (!err)
1240 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1241 
1242 	if (err)
1243 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1244 
1245 	return err;
1246 }
1247 
1248 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1249 {
1250 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1251 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1252 	percpu_counter_destroy(&sbi->s_dirs_counter);
1253 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1254 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1255 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1256 }
1257 
1258 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1259 {
1260 	struct buffer_head **group_desc;
1261 	int i;
1262 
1263 	group_desc = rcu_access_pointer(sbi->s_group_desc);
1264 	for (i = 0; i < sbi->s_gdb_count; i++)
1265 		brelse(group_desc[i]);
1266 	kvfree(group_desc);
1267 }
1268 
1269 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1270 {
1271 	struct flex_groups **flex_groups;
1272 	int i;
1273 
1274 	flex_groups = rcu_access_pointer(sbi->s_flex_groups);
1275 	if (flex_groups) {
1276 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1277 			kvfree(flex_groups[i]);
1278 		kvfree(flex_groups);
1279 	}
1280 }
1281 
1282 static void ext4_put_super(struct super_block *sb)
1283 {
1284 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1285 	struct ext4_super_block *es = sbi->s_es;
1286 	int aborted = 0;
1287 	int err;
1288 
1289 	/*
1290 	 * Unregister sysfs before destroying jbd2 journal.
1291 	 * Since we could still access attr_journal_task attribute via sysfs
1292 	 * path which could have sbi->s_journal->j_task as NULL
1293 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1294 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1295 	 * read metadata verify failed then will queue error work.
1296 	 * update_super_work will call start_this_handle may trigger
1297 	 * BUG_ON.
1298 	 */
1299 	ext4_unregister_sysfs(sb);
1300 
1301 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1302 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1303 			 &sb->s_uuid);
1304 
1305 	ext4_unregister_li_request(sb);
1306 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1307 
1308 	destroy_workqueue(sbi->rsv_conversion_wq);
1309 	ext4_release_orphan_info(sb);
1310 
1311 	if (sbi->s_journal) {
1312 		aborted = is_journal_aborted(sbi->s_journal);
1313 		err = ext4_journal_destroy(sbi, sbi->s_journal);
1314 		if ((err < 0) && !aborted) {
1315 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1316 		}
1317 	} else
1318 		flush_work(&sbi->s_sb_upd_work);
1319 
1320 	ext4_es_unregister_shrinker(sbi);
1321 	timer_shutdown_sync(&sbi->s_err_report);
1322 	ext4_release_system_zone(sb);
1323 	ext4_mb_release(sb);
1324 	ext4_ext_release(sb);
1325 
1326 	if (!ext4_emergency_state(sb) && !sb_rdonly(sb)) {
1327 		if (!aborted) {
1328 			ext4_clear_feature_journal_needs_recovery(sb);
1329 			ext4_clear_feature_orphan_present(sb);
1330 			es->s_state = cpu_to_le16(sbi->s_mount_state);
1331 		}
1332 		ext4_commit_super(sb);
1333 	}
1334 
1335 	ext4_group_desc_free(sbi);
1336 	ext4_flex_groups_free(sbi);
1337 
1338 	WARN_ON_ONCE(!(sbi->s_mount_state & EXT4_ERROR_FS) &&
1339 		     percpu_counter_sum(&sbi->s_dirtyclusters_counter));
1340 	ext4_percpu_param_destroy(sbi);
1341 #ifdef CONFIG_QUOTA
1342 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1343 		kfree(get_qf_name(sb, sbi, i));
1344 #endif
1345 
1346 	/* Debugging code just in case the in-memory inode orphan list
1347 	 * isn't empty.  The on-disk one can be non-empty if we've
1348 	 * detected an error and taken the fs readonly, but the
1349 	 * in-memory list had better be clean by this point. */
1350 	if (!list_empty(&sbi->s_orphan))
1351 		dump_orphan_list(sb, sbi);
1352 	ASSERT(list_empty(&sbi->s_orphan));
1353 
1354 	sync_blockdev(sb->s_bdev);
1355 	invalidate_bdev(sb->s_bdev);
1356 	if (sbi->s_journal_bdev_file) {
1357 		/*
1358 		 * Invalidate the journal device's buffers.  We don't want them
1359 		 * floating about in memory - the physical journal device may
1360 		 * hotswapped, and it breaks the `ro-after' testing code.
1361 		 */
1362 		sync_blockdev(file_bdev(sbi->s_journal_bdev_file));
1363 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
1364 	}
1365 
1366 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1367 	sbi->s_ea_inode_cache = NULL;
1368 
1369 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1370 	sbi->s_ea_block_cache = NULL;
1371 
1372 	ext4_stop_mmpd(sbi);
1373 
1374 	brelse(sbi->s_sbh);
1375 	sb->s_fs_info = NULL;
1376 	/*
1377 	 * Now that we are completely done shutting down the
1378 	 * superblock, we need to actually destroy the kobject.
1379 	 */
1380 	kobject_put(&sbi->s_kobj);
1381 	wait_for_completion(&sbi->s_kobj_unregister);
1382 	kfree(sbi->s_blockgroup_lock);
1383 	fs_put_dax(sbi->s_daxdev, NULL);
1384 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1385 #if IS_ENABLED(CONFIG_UNICODE)
1386 	utf8_unload(sb->s_encoding);
1387 #endif
1388 	kfree(sbi);
1389 }
1390 
1391 static struct kmem_cache *ext4_inode_cachep;
1392 
1393 /*
1394  * Called inside transaction, so use GFP_NOFS
1395  */
1396 static struct inode *ext4_alloc_inode(struct super_block *sb)
1397 {
1398 	struct ext4_inode_info *ei;
1399 
1400 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1401 	if (!ei)
1402 		return NULL;
1403 
1404 	inode_set_iversion(&ei->vfs_inode, 1);
1405 	ei->i_flags = 0;
1406 	ext4_clear_state_flags(ei);	/* Only relevant on 32-bit archs */
1407 	spin_lock_init(&ei->i_raw_lock);
1408 	ei->i_prealloc_node = RB_ROOT;
1409 	atomic_set(&ei->i_prealloc_active, 0);
1410 	rwlock_init(&ei->i_prealloc_lock);
1411 	ext4_es_init_tree(&ei->i_es_tree);
1412 	rwlock_init(&ei->i_es_lock);
1413 	INIT_LIST_HEAD(&ei->i_es_list);
1414 	ei->i_es_all_nr = 0;
1415 	ei->i_es_shk_nr = 0;
1416 	ei->i_es_shrink_lblk = 0;
1417 	ei->i_es_seq = 0;
1418 	ei->i_reserved_data_blocks = 0;
1419 	spin_lock_init(&(ei->i_block_reservation_lock));
1420 	ext4_init_pending_tree(&ei->i_pending_tree);
1421 #ifdef CONFIG_QUOTA
1422 	ei->i_reserved_quota = 0;
1423 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1424 #endif
1425 	ei->jinode = NULL;
1426 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1427 	spin_lock_init(&ei->i_completed_io_lock);
1428 	ei->i_sync_tid = 0;
1429 	ei->i_datasync_tid = 0;
1430 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1431 	ext4_fc_init_inode(&ei->vfs_inode);
1432 	spin_lock_init(&ei->i_fc_lock);
1433 	mmb_init(&ei->i_metadata_bhs, &ei->vfs_inode.i_data);
1434 	return &ei->vfs_inode;
1435 }
1436 
1437 static int ext4_drop_inode(struct inode *inode)
1438 {
1439 	int drop = inode_generic_drop(inode);
1440 
1441 	if (!drop)
1442 		drop = fscrypt_drop_inode(inode);
1443 
1444 	trace_ext4_drop_inode(inode, drop);
1445 	return drop;
1446 }
1447 
1448 static void ext4_free_in_core_inode(struct inode *inode)
1449 {
1450 	fscrypt_free_inode(inode);
1451 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1452 		pr_warn("%s: inode %llu still in fc list",
1453 			__func__, inode->i_ino);
1454 	}
1455 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1456 }
1457 
1458 static void ext4_destroy_inode(struct inode *inode)
1459 {
1460 	if (ext4_inode_orphan_tracked(inode)) {
1461 		ext4_msg(inode->i_sb, KERN_ERR,
1462 			 "Inode %llu (%p): inode tracked as orphan!",
1463 			 inode->i_ino, EXT4_I(inode));
1464 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1465 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1466 				true);
1467 		dump_stack();
1468 	}
1469 
1470 	if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
1471 	    WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
1472 		ext4_msg(inode->i_sb, KERN_ERR,
1473 			 "Inode %llu (%p): i_reserved_data_blocks (%u) not cleared!",
1474 			 inode->i_ino, EXT4_I(inode),
1475 			 EXT4_I(inode)->i_reserved_data_blocks);
1476 }
1477 
1478 static void ext4_shutdown(struct super_block *sb)
1479 {
1480        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1481 }
1482 
1483 static void init_once(void *foo)
1484 {
1485 	struct ext4_inode_info *ei = foo;
1486 
1487 	INIT_LIST_HEAD(&ei->i_orphan);
1488 	init_rwsem(&ei->xattr_sem);
1489 	init_rwsem(&ei->i_data_sem);
1490 	inode_init_once(&ei->vfs_inode);
1491 	ext4_fc_init_inode(&ei->vfs_inode);
1492 #ifdef CONFIG_FS_ENCRYPTION
1493 	ei->i_crypt_info = NULL;
1494 #endif
1495 }
1496 
1497 static int __init init_inodecache(void)
1498 {
1499 	struct kmem_cache_args args = {
1500 		.useroffset = offsetof(struct ext4_inode_info, i_data),
1501 		.usersize = sizeof_field(struct ext4_inode_info, i_data),
1502 		.use_freeptr_offset = true,
1503 		.freeptr_offset = offsetof(struct ext4_inode_info, i_flags),
1504 		.ctor = init_once,
1505 	};
1506 
1507 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1508 				sizeof(struct ext4_inode_info),
1509 				&args,
1510 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT);
1511 
1512 	if (ext4_inode_cachep == NULL)
1513 		return -ENOMEM;
1514 	return 0;
1515 }
1516 
1517 static void destroy_inodecache(void)
1518 {
1519 	/*
1520 	 * Make sure all delayed rcu free inodes are flushed before we
1521 	 * destroy cache.
1522 	 */
1523 	rcu_barrier();
1524 	kmem_cache_destroy(ext4_inode_cachep);
1525 }
1526 
1527 void ext4_clear_inode(struct inode *inode)
1528 {
1529 	ext4_fc_del(inode);
1530 	if (!EXT4_SB(inode->i_sb)->s_journal)
1531 		mmb_invalidate(&EXT4_I(inode)->i_metadata_bhs);
1532 	clear_inode(inode);
1533 	ext4_discard_preallocations(inode);
1534 	/*
1535 	 * We must remove the inode from the hash before ext4_free_inode()
1536 	 * clears the bit in inode bitmap as otherwise another process reusing
1537 	 * the inode will block in insert_inode_hash() waiting for inode
1538 	 * eviction to complete while holding transaction handle open, but
1539 	 * ext4_evict_inode() still running for that inode could block waiting
1540 	 * for transaction commit if the inode is marked as IS_SYNC => deadlock.
1541 	 *
1542 	 * Removing the inode from the hash here is safe. There are two cases
1543 	 * to consider:
1544 	 * 1) The inode still has references to it (i_nlink > 0). In that case
1545 	 * we are keeping the inode and once we remove the inode from the hash,
1546 	 * iget() can create the new inode structure for the same inode number
1547 	 * and we are fine with that as all IO on behalf of the inode is
1548 	 * finished.
1549 	 * 2) We are deleting the inode (i_nlink == 0). In that case inode
1550 	 * number cannot be reused until ext4_free_inode() clears the bit in
1551 	 * the inode bitmap, at which point all IO is done and reuse is fine
1552 	 * again.
1553 	 */
1554 	remove_inode_hash(inode);
1555 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1556 	dquot_drop(inode);
1557 	if (EXT4_I(inode)->jinode) {
1558 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1559 					       EXT4_I(inode)->jinode);
1560 		jbd2_free_inode(EXT4_I(inode)->jinode);
1561 		EXT4_I(inode)->jinode = NULL;
1562 	}
1563 	fscrypt_put_encryption_info(inode);
1564 }
1565 
1566 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1567 					u64 ino, u32 generation)
1568 {
1569 	struct inode *inode;
1570 
1571 	/*
1572 	 * Currently we don't know the generation for parent directory, so
1573 	 * a generation of 0 means "accept any"
1574 	 */
1575 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1576 	if (IS_ERR(inode))
1577 		return ERR_CAST(inode);
1578 	if (generation && inode->i_generation != generation) {
1579 		iput(inode);
1580 		return ERR_PTR(-ESTALE);
1581 	}
1582 
1583 	return inode;
1584 }
1585 
1586 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1587 					int fh_len, int fh_type)
1588 {
1589 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1590 				    ext4_nfs_get_inode);
1591 }
1592 
1593 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1594 					int fh_len, int fh_type)
1595 {
1596 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1597 				    ext4_nfs_get_inode);
1598 }
1599 
1600 static int ext4_nfs_commit_metadata(struct inode *inode)
1601 {
1602 	struct writeback_control wbc = {
1603 		.sync_mode = WB_SYNC_ALL
1604 	};
1605 
1606 	trace_ext4_nfs_commit_metadata(inode);
1607 	return ext4_write_inode(inode, &wbc);
1608 }
1609 
1610 #ifdef CONFIG_QUOTA
1611 static const char * const quotatypes[] = INITQFNAMES;
1612 #define QTYPE2NAME(t) (quotatypes[t])
1613 
1614 static int ext4_write_dquot(struct dquot *dquot);
1615 static int ext4_acquire_dquot(struct dquot *dquot);
1616 static int ext4_release_dquot(struct dquot *dquot);
1617 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1618 static int ext4_write_info(struct super_block *sb, int type);
1619 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1620 			 const struct path *path);
1621 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1622 			       size_t len, loff_t off);
1623 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1624 				const char *data, size_t len, loff_t off);
1625 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1626 			     unsigned int flags);
1627 
1628 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1629 {
1630 	return EXT4_I(inode)->i_dquot;
1631 }
1632 
1633 static const struct dquot_operations ext4_quota_operations = {
1634 	.get_reserved_space	= ext4_get_reserved_space,
1635 	.write_dquot		= ext4_write_dquot,
1636 	.acquire_dquot		= ext4_acquire_dquot,
1637 	.release_dquot		= ext4_release_dquot,
1638 	.mark_dirty		= ext4_mark_dquot_dirty,
1639 	.write_info		= ext4_write_info,
1640 	.alloc_dquot		= dquot_alloc,
1641 	.destroy_dquot		= dquot_destroy,
1642 	.get_projid		= ext4_get_projid,
1643 	.get_inode_usage	= ext4_get_inode_usage,
1644 	.get_next_id		= dquot_get_next_id,
1645 };
1646 
1647 static const struct quotactl_ops ext4_qctl_operations = {
1648 	.quota_on	= ext4_quota_on,
1649 	.quota_off	= ext4_quota_off,
1650 	.quota_sync	= dquot_quota_sync,
1651 	.get_state	= dquot_get_state,
1652 	.set_info	= dquot_set_dqinfo,
1653 	.get_dqblk	= dquot_get_dqblk,
1654 	.set_dqblk	= dquot_set_dqblk,
1655 	.get_nextdqblk	= dquot_get_next_dqblk,
1656 };
1657 #endif
1658 
1659 static const struct super_operations ext4_sops = {
1660 	.alloc_inode	= ext4_alloc_inode,
1661 	.free_inode	= ext4_free_in_core_inode,
1662 	.destroy_inode	= ext4_destroy_inode,
1663 	.write_inode	= ext4_write_inode,
1664 	.dirty_inode	= ext4_dirty_inode,
1665 	.drop_inode	= ext4_drop_inode,
1666 	.evict_inode	= ext4_evict_inode,
1667 	.put_super	= ext4_put_super,
1668 	.sync_fs	= ext4_sync_fs,
1669 	.freeze_fs	= ext4_freeze,
1670 	.unfreeze_fs	= ext4_unfreeze,
1671 	.statfs		= ext4_statfs,
1672 	.show_options	= ext4_show_options,
1673 	.shutdown	= ext4_shutdown,
1674 #ifdef CONFIG_QUOTA
1675 	.quota_read	= ext4_quota_read,
1676 	.quota_write	= ext4_quota_write,
1677 	.get_dquots	= ext4_get_dquots,
1678 #endif
1679 };
1680 
1681 static const struct export_operations ext4_export_ops = {
1682 	.encode_fh = generic_encode_ino32_fh,
1683 	.fh_to_dentry = ext4_fh_to_dentry,
1684 	.fh_to_parent = ext4_fh_to_parent,
1685 	.get_parent = ext4_get_parent,
1686 	.commit_metadata = ext4_nfs_commit_metadata,
1687 };
1688 
1689 enum {
1690 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1691 	Opt_resgid, Opt_resuid, Opt_sb,
1692 	Opt_nouid32, Opt_debug, Opt_removed,
1693 	Opt_user_xattr, Opt_acl,
1694 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1695 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1696 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1697 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1698 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1699 	Opt_inlinecrypt,
1700 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1701 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1702 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1703 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1704 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1705 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1706 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1707 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1708 	Opt_dioread_nolock, Opt_dioread_lock,
1709 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1710 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1711 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1712 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1713 #ifdef CONFIG_EXT4_DEBUG
1714 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1715 #endif
1716 };
1717 
1718 static const struct constant_table ext4_param_errors[] = {
1719 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1720 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1721 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1722 	{}
1723 };
1724 
1725 static const struct constant_table ext4_param_data[] = {
1726 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1727 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1728 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1729 	{}
1730 };
1731 
1732 static const struct constant_table ext4_param_data_err[] = {
1733 	{"abort",	Opt_data_err_abort},
1734 	{"ignore",	Opt_data_err_ignore},
1735 	{}
1736 };
1737 
1738 static const struct constant_table ext4_param_jqfmt[] = {
1739 	{"vfsold",	QFMT_VFS_OLD},
1740 	{"vfsv0",	QFMT_VFS_V0},
1741 	{"vfsv1",	QFMT_VFS_V1},
1742 	{}
1743 };
1744 
1745 static const struct constant_table ext4_param_dax[] = {
1746 	{"always",	Opt_dax_always},
1747 	{"inode",	Opt_dax_inode},
1748 	{"never",	Opt_dax_never},
1749 	{}
1750 };
1751 
1752 /*
1753  * Mount option specification
1754  * We don't use fsparam_flag_no because of the way we set the
1755  * options and the way we show them in _ext4_show_options(). To
1756  * keep the changes to a minimum, let's keep the negative options
1757  * separate for now.
1758  */
1759 static const struct fs_parameter_spec ext4_param_specs[] = {
1760 	fsparam_flag	("bsddf",		Opt_bsd_df),
1761 	fsparam_flag	("minixdf",		Opt_minix_df),
1762 	fsparam_flag	("grpid",		Opt_grpid),
1763 	fsparam_flag	("bsdgroups",		Opt_grpid),
1764 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1765 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1766 	fsparam_gid	("resgid",		Opt_resgid),
1767 	fsparam_uid	("resuid",		Opt_resuid),
1768 	fsparam_u32	("sb",			Opt_sb),
1769 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1770 	fsparam_flag	("nouid32",		Opt_nouid32),
1771 	fsparam_flag	("debug",		Opt_debug),
1772 	fsparam_flag	("oldalloc",		Opt_removed),
1773 	fsparam_flag	("orlov",		Opt_removed),
1774 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1775 	fsparam_flag	("acl",			Opt_acl),
1776 	fsparam_flag	("norecovery",		Opt_noload),
1777 	fsparam_flag	("noload",		Opt_noload),
1778 	fsparam_flag	("bh",			Opt_removed),
1779 	fsparam_flag	("nobh",		Opt_removed),
1780 	fsparam_u32	("commit",		Opt_commit),
1781 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1782 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1783 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1784 	fsparam_bdev	("journal_path",	Opt_journal_path),
1785 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1786 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1787 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1788 	fsparam_flag	("abort",		Opt_abort),
1789 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1790 	fsparam_enum	("data_err",		Opt_data_err,
1791 						ext4_param_data_err),
1792 	fsparam_string_empty
1793 			("usrjquota",		Opt_usrjquota),
1794 	fsparam_string_empty
1795 			("grpjquota",		Opt_grpjquota),
1796 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1797 	fsparam_flag	("grpquota",		Opt_grpquota),
1798 	fsparam_flag	("quota",		Opt_quota),
1799 	fsparam_flag	("noquota",		Opt_noquota),
1800 	fsparam_flag	("usrquota",		Opt_usrquota),
1801 	fsparam_flag	("prjquota",		Opt_prjquota),
1802 	fsparam_flag	("barrier",		Opt_barrier),
1803 	fsparam_u32	("barrier",		Opt_barrier),
1804 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1805 	fsparam_flag	("i_version",		Opt_removed),
1806 	fsparam_flag	("dax",			Opt_dax),
1807 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1808 	fsparam_u32	("stripe",		Opt_stripe),
1809 	fsparam_flag	("delalloc",		Opt_delalloc),
1810 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1811 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1812 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1813 	fsparam_u32	("debug_want_extra_isize",
1814 						Opt_debug_want_extra_isize),
1815 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1816 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1817 	fsparam_flag	("block_validity",	Opt_block_validity),
1818 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1819 	fsparam_u32	("inode_readahead_blks",
1820 						Opt_inode_readahead_blks),
1821 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1822 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1823 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1824 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1825 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1826 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1827 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1828 	fsparam_flag	("discard",		Opt_discard),
1829 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1830 	fsparam_u32	("init_itable",		Opt_init_itable),
1831 	fsparam_flag	("init_itable",		Opt_init_itable),
1832 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1833 #ifdef CONFIG_EXT4_DEBUG
1834 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1835 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1836 #endif
1837 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1838 	fsparam_flag	("test_dummy_encryption",
1839 						Opt_test_dummy_encryption),
1840 	fsparam_string	("test_dummy_encryption",
1841 						Opt_test_dummy_encryption),
1842 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1843 	fsparam_flag	("nombcache",		Opt_nombcache),
1844 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1845 	fsparam_flag	("prefetch_block_bitmaps",
1846 						Opt_removed),
1847 	fsparam_flag	("no_prefetch_block_bitmaps",
1848 						Opt_no_prefetch_block_bitmaps),
1849 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1850 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1851 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1852 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1853 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1854 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1855 	{}
1856 };
1857 
1858 
1859 #define MOPT_SET	0x0001
1860 #define MOPT_CLEAR	0x0002
1861 #define MOPT_NOSUPPORT	0x0004
1862 #define MOPT_EXPLICIT	0x0008
1863 #ifdef CONFIG_QUOTA
1864 #define MOPT_Q		0
1865 #define MOPT_QFMT	0x0010
1866 #else
1867 #define MOPT_Q		MOPT_NOSUPPORT
1868 #define MOPT_QFMT	MOPT_NOSUPPORT
1869 #endif
1870 #define MOPT_NO_EXT2	0x0020
1871 #define MOPT_NO_EXT3	0x0040
1872 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1873 #define MOPT_SKIP	0x0080
1874 #define	MOPT_2		0x0100
1875 
1876 static const struct mount_opts {
1877 	int	token;
1878 	int	mount_opt;
1879 	int	flags;
1880 } ext4_mount_opts[] = {
1881 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1882 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1883 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1884 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1885 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1886 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1887 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1888 	 MOPT_EXT4_ONLY | MOPT_SET},
1889 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1890 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1891 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1892 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1893 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1894 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1895 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1896 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1897 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1898 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1899 	{Opt_commit, 0, MOPT_NO_EXT2},
1900 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1901 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1902 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1903 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1904 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1905 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1906 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1907 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1908 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1909 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1910 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1911 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1912 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1913 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1914 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1915 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1916 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1917 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1918 	{Opt_data, 0, MOPT_NO_EXT2},
1919 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1920 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1921 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1922 #else
1923 	{Opt_acl, 0, MOPT_NOSUPPORT},
1924 #endif
1925 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1926 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1927 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1928 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1929 							MOPT_SET | MOPT_Q},
1930 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1931 							MOPT_SET | MOPT_Q},
1932 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1933 							MOPT_SET | MOPT_Q},
1934 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1935 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1936 							MOPT_CLEAR | MOPT_Q},
1937 	{Opt_usrjquota, 0, MOPT_Q},
1938 	{Opt_grpjquota, 0, MOPT_Q},
1939 	{Opt_jqfmt, 0, MOPT_QFMT},
1940 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1941 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1942 	 MOPT_SET},
1943 #ifdef CONFIG_EXT4_DEBUG
1944 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1945 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1946 #endif
1947 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1948 	{Opt_err, 0, 0}
1949 };
1950 
1951 #if IS_ENABLED(CONFIG_UNICODE)
1952 static const struct ext4_sb_encodings {
1953 	__u16 magic;
1954 	char *name;
1955 	unsigned int version;
1956 } ext4_sb_encoding_map[] = {
1957 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1958 };
1959 
1960 static const struct ext4_sb_encodings *
1961 ext4_sb_read_encoding(const struct ext4_super_block *es)
1962 {
1963 	__u16 magic = le16_to_cpu(es->s_encoding);
1964 	int i;
1965 
1966 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1967 		if (magic == ext4_sb_encoding_map[i].magic)
1968 			return &ext4_sb_encoding_map[i];
1969 
1970 	return NULL;
1971 }
1972 #endif
1973 
1974 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1975 #define EXT4_SPEC_JQFMT				(1 <<  1)
1976 #define EXT4_SPEC_DATAJ				(1 <<  2)
1977 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1978 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1979 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1980 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1981 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1982 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1983 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1984 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1985 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1986 #define EXT4_SPEC_s_stripe			(1 << 13)
1987 #define EXT4_SPEC_s_resuid			(1 << 14)
1988 #define EXT4_SPEC_s_resgid			(1 << 15)
1989 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1990 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1991 #define EXT4_SPEC_s_sb_block			(1 << 18)
1992 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1993 
1994 struct ext4_fs_context {
1995 	char		*s_qf_names[EXT4_MAXQUOTAS];
1996 	struct fscrypt_dummy_policy dummy_enc_policy;
1997 	int		s_jquota_fmt;	/* Format of quota to use */
1998 #ifdef CONFIG_EXT4_DEBUG
1999 	int s_fc_debug_max_replay;
2000 #endif
2001 	unsigned short	qname_spec;
2002 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
2003 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
2004 	unsigned long	journal_devnum;
2005 	unsigned long	s_commit_interval;
2006 	unsigned long	s_stripe;
2007 	unsigned int	s_inode_readahead_blks;
2008 	unsigned int	s_want_extra_isize;
2009 	unsigned int	s_li_wait_mult;
2010 	unsigned int	s_max_dir_size_kb;
2011 	unsigned int	journal_ioprio;
2012 	unsigned int	vals_s_mount_opt;
2013 	unsigned int	mask_s_mount_opt;
2014 	unsigned int	vals_s_mount_opt2;
2015 	unsigned int	mask_s_mount_opt2;
2016 	unsigned int	opt_flags;	/* MOPT flags */
2017 	unsigned int	spec;
2018 	u32		s_max_batch_time;
2019 	u32		s_min_batch_time;
2020 	kuid_t		s_resuid;
2021 	kgid_t		s_resgid;
2022 	ext4_fsblk_t	s_sb_block;
2023 };
2024 
2025 static void ext4_fc_free(struct fs_context *fc)
2026 {
2027 	struct ext4_fs_context *ctx = fc->fs_private;
2028 	int i;
2029 
2030 	if (!ctx)
2031 		return;
2032 
2033 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2034 		kfree(ctx->s_qf_names[i]);
2035 
2036 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2037 	kfree(ctx);
2038 }
2039 
2040 int ext4_init_fs_context(struct fs_context *fc)
2041 {
2042 	struct ext4_fs_context *ctx;
2043 
2044 	ctx = kzalloc_obj(struct ext4_fs_context);
2045 	if (!ctx)
2046 		return -ENOMEM;
2047 
2048 	fc->fs_private = ctx;
2049 	fc->ops = &ext4_context_ops;
2050 
2051 	/* i_version is always enabled now */
2052 	fc->sb_flags |= SB_I_VERSION;
2053 
2054 	return 0;
2055 }
2056 
2057 #ifdef CONFIG_QUOTA
2058 /*
2059  * Note the name of the specified quota file.
2060  */
2061 static int note_qf_name(struct fs_context *fc, int qtype,
2062 		       struct fs_parameter *param)
2063 {
2064 	struct ext4_fs_context *ctx = fc->fs_private;
2065 	char *qname;
2066 
2067 	if (param->size < 1) {
2068 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2069 		return -EINVAL;
2070 	}
2071 	if (strchr(param->string, '/')) {
2072 		ext4_msg(NULL, KERN_ERR,
2073 			 "quotafile must be on filesystem root");
2074 		return -EINVAL;
2075 	}
2076 	if (ctx->s_qf_names[qtype]) {
2077 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2078 			ext4_msg(NULL, KERN_ERR,
2079 				 "%s quota file already specified",
2080 				 QTYPE2NAME(qtype));
2081 			return -EINVAL;
2082 		}
2083 		return 0;
2084 	}
2085 
2086 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2087 	if (!qname) {
2088 		ext4_msg(NULL, KERN_ERR,
2089 			 "Not enough memory for storing quotafile name");
2090 		return -ENOMEM;
2091 	}
2092 	ctx->s_qf_names[qtype] = qname;
2093 	ctx->qname_spec |= 1 << qtype;
2094 	ctx->spec |= EXT4_SPEC_JQUOTA;
2095 	return 0;
2096 }
2097 
2098 /*
2099  * Clear the name of the specified quota file.
2100  */
2101 static int unnote_qf_name(struct fs_context *fc, int qtype)
2102 {
2103 	struct ext4_fs_context *ctx = fc->fs_private;
2104 
2105 	kfree(ctx->s_qf_names[qtype]);
2106 
2107 	ctx->s_qf_names[qtype] = NULL;
2108 	ctx->qname_spec |= 1 << qtype;
2109 	ctx->spec |= EXT4_SPEC_JQUOTA;
2110 	return 0;
2111 }
2112 #endif
2113 
2114 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2115 					    struct ext4_fs_context *ctx)
2116 {
2117 	int err;
2118 
2119 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2120 		ext4_msg(NULL, KERN_WARNING,
2121 			 "test_dummy_encryption option not supported");
2122 		return -EINVAL;
2123 	}
2124 	err = fscrypt_parse_test_dummy_encryption(param,
2125 						  &ctx->dummy_enc_policy);
2126 	if (err == -EINVAL) {
2127 		ext4_msg(NULL, KERN_WARNING,
2128 			 "Value of option \"%s\" is unrecognized", param->key);
2129 	} else if (err == -EEXIST) {
2130 		ext4_msg(NULL, KERN_WARNING,
2131 			 "Conflicting test_dummy_encryption options");
2132 		return -EINVAL;
2133 	}
2134 	return err;
2135 }
2136 
2137 #define EXT4_SET_CTX(name)						\
2138 static inline __maybe_unused						\
2139 void ctx_set_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2140 {									\
2141 	ctx->mask_s_##name |= flag;					\
2142 	ctx->vals_s_##name |= flag;					\
2143 }
2144 
2145 #define EXT4_CLEAR_CTX(name)						\
2146 static inline __maybe_unused						\
2147 void ctx_clear_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2148 {									\
2149 	ctx->mask_s_##name |= flag;					\
2150 	ctx->vals_s_##name &= ~flag;					\
2151 }
2152 
2153 #define EXT4_TEST_CTX(name)						\
2154 static inline unsigned long						\
2155 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2156 {									\
2157 	return (ctx->vals_s_##name & flag);				\
2158 }
2159 
2160 EXT4_SET_CTX(flags); /* set only */
2161 EXT4_SET_CTX(mount_opt);
2162 EXT4_CLEAR_CTX(mount_opt);
2163 EXT4_TEST_CTX(mount_opt);
2164 EXT4_SET_CTX(mount_opt2);
2165 EXT4_CLEAR_CTX(mount_opt2);
2166 EXT4_TEST_CTX(mount_opt2);
2167 
2168 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2169 {
2170 	struct ext4_fs_context *ctx = fc->fs_private;
2171 	struct fs_parse_result result;
2172 	const struct mount_opts *m;
2173 	int is_remount;
2174 	int token;
2175 
2176 	token = fs_parse(fc, ext4_param_specs, param, &result);
2177 	if (token < 0)
2178 		return token;
2179 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2180 
2181 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2182 		if (token == m->token)
2183 			break;
2184 
2185 	ctx->opt_flags |= m->flags;
2186 
2187 	if (m->flags & MOPT_EXPLICIT) {
2188 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2189 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2190 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2191 			ctx_set_mount_opt2(ctx,
2192 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2193 		} else
2194 			return -EINVAL;
2195 	}
2196 
2197 	if (m->flags & MOPT_NOSUPPORT) {
2198 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2199 			 param->key);
2200 		return 0;
2201 	}
2202 
2203 	switch (token) {
2204 #ifdef CONFIG_QUOTA
2205 	case Opt_usrjquota:
2206 		if (!*param->string)
2207 			return unnote_qf_name(fc, USRQUOTA);
2208 		else
2209 			return note_qf_name(fc, USRQUOTA, param);
2210 	case Opt_grpjquota:
2211 		if (!*param->string)
2212 			return unnote_qf_name(fc, GRPQUOTA);
2213 		else
2214 			return note_qf_name(fc, GRPQUOTA, param);
2215 #endif
2216 	case Opt_sb:
2217 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2218 			ext4_msg(NULL, KERN_WARNING,
2219 				 "Ignoring %s option on remount", param->key);
2220 		} else {
2221 			ctx->s_sb_block = result.uint_32;
2222 			ctx->spec |= EXT4_SPEC_s_sb_block;
2223 		}
2224 		return 0;
2225 	case Opt_removed:
2226 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2227 			 param->key);
2228 		return 0;
2229 	case Opt_inlinecrypt:
2230 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2231 		ctx_set_flags(ctx, SB_INLINECRYPT);
2232 #else
2233 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2234 #endif
2235 		return 0;
2236 	case Opt_errors:
2237 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2238 		ctx_set_mount_opt(ctx, result.uint_32);
2239 		return 0;
2240 #ifdef CONFIG_QUOTA
2241 	case Opt_jqfmt:
2242 		ctx->s_jquota_fmt = result.uint_32;
2243 		ctx->spec |= EXT4_SPEC_JQFMT;
2244 		return 0;
2245 #endif
2246 	case Opt_data:
2247 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2248 		ctx_set_mount_opt(ctx, result.uint_32);
2249 		ctx->spec |= EXT4_SPEC_DATAJ;
2250 		return 0;
2251 	case Opt_commit:
2252 		if (result.uint_32 == 0)
2253 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2254 		else if (result.uint_32 > INT_MAX / HZ) {
2255 			ext4_msg(NULL, KERN_ERR,
2256 				 "Invalid commit interval %d, "
2257 				 "must be smaller than %d",
2258 				 result.uint_32, INT_MAX / HZ);
2259 			return -EINVAL;
2260 		}
2261 		ctx->s_commit_interval = HZ * result.uint_32;
2262 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2263 		return 0;
2264 	case Opt_debug_want_extra_isize:
2265 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2266 			ext4_msg(NULL, KERN_ERR,
2267 				 "Invalid want_extra_isize %d", result.uint_32);
2268 			return -EINVAL;
2269 		}
2270 		ctx->s_want_extra_isize = result.uint_32;
2271 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2272 		return 0;
2273 	case Opt_max_batch_time:
2274 		ctx->s_max_batch_time = result.uint_32;
2275 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2276 		return 0;
2277 	case Opt_min_batch_time:
2278 		ctx->s_min_batch_time = result.uint_32;
2279 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2280 		return 0;
2281 	case Opt_inode_readahead_blks:
2282 		if (result.uint_32 &&
2283 		    (result.uint_32 > (1 << 30) ||
2284 		     !is_power_of_2(result.uint_32))) {
2285 			ext4_msg(NULL, KERN_ERR,
2286 				 "EXT4-fs: inode_readahead_blks must be "
2287 				 "0 or a power of 2 smaller than 2^31");
2288 			return -EINVAL;
2289 		}
2290 		ctx->s_inode_readahead_blks = result.uint_32;
2291 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2292 		return 0;
2293 	case Opt_init_itable:
2294 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2295 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2296 		if (param->type == fs_value_is_string)
2297 			ctx->s_li_wait_mult = result.uint_32;
2298 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2299 		return 0;
2300 	case Opt_max_dir_size_kb:
2301 		ctx->s_max_dir_size_kb = result.uint_32;
2302 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2303 		return 0;
2304 #ifdef CONFIG_EXT4_DEBUG
2305 	case Opt_fc_debug_max_replay:
2306 		ctx->s_fc_debug_max_replay = result.uint_32;
2307 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2308 		return 0;
2309 #endif
2310 	case Opt_stripe:
2311 		ctx->s_stripe = result.uint_32;
2312 		ctx->spec |= EXT4_SPEC_s_stripe;
2313 		return 0;
2314 	case Opt_resuid:
2315 		ctx->s_resuid = result.uid;
2316 		ctx->spec |= EXT4_SPEC_s_resuid;
2317 		return 0;
2318 	case Opt_resgid:
2319 		ctx->s_resgid = result.gid;
2320 		ctx->spec |= EXT4_SPEC_s_resgid;
2321 		return 0;
2322 	case Opt_journal_dev:
2323 		if (is_remount) {
2324 			ext4_msg(NULL, KERN_ERR,
2325 				 "Cannot specify journal on remount");
2326 			return -EINVAL;
2327 		}
2328 		ctx->journal_devnum = result.uint_32;
2329 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2330 		return 0;
2331 	case Opt_journal_path:
2332 	{
2333 		struct inode *journal_inode;
2334 		struct path path;
2335 		int error;
2336 
2337 		if (is_remount) {
2338 			ext4_msg(NULL, KERN_ERR,
2339 				 "Cannot specify journal on remount");
2340 			return -EINVAL;
2341 		}
2342 
2343 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2344 		if (error) {
2345 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2346 				 "journal device path");
2347 			return -EINVAL;
2348 		}
2349 
2350 		journal_inode = d_inode(path.dentry);
2351 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2352 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2353 		path_put(&path);
2354 		return 0;
2355 	}
2356 	case Opt_journal_ioprio:
2357 		if (result.uint_32 > 7) {
2358 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2359 				 " (must be 0-7)");
2360 			return -EINVAL;
2361 		}
2362 		ctx->journal_ioprio =
2363 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2364 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2365 		return 0;
2366 	case Opt_test_dummy_encryption:
2367 		return ext4_parse_test_dummy_encryption(param, ctx);
2368 	case Opt_dax:
2369 	case Opt_dax_type:
2370 #ifdef CONFIG_FS_DAX
2371 	{
2372 		int type = (token == Opt_dax) ?
2373 			   Opt_dax : result.uint_32;
2374 
2375 		switch (type) {
2376 		case Opt_dax:
2377 		case Opt_dax_always:
2378 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2379 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2380 			break;
2381 		case Opt_dax_never:
2382 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2383 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2384 			break;
2385 		case Opt_dax_inode:
2386 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2387 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2388 			/* Strictly for printing options */
2389 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2390 			break;
2391 		}
2392 		return 0;
2393 	}
2394 #else
2395 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2396 		return -EINVAL;
2397 #endif
2398 	case Opt_data_err:
2399 		if (result.uint_32 == Opt_data_err_abort)
2400 			ctx_set_mount_opt(ctx, m->mount_opt);
2401 		else if (result.uint_32 == Opt_data_err_ignore)
2402 			ctx_clear_mount_opt(ctx, m->mount_opt);
2403 		return 0;
2404 	case Opt_mb_optimize_scan:
2405 		if (result.int_32 == 1) {
2406 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2407 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2408 		} else if (result.int_32 == 0) {
2409 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2410 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2411 		} else {
2412 			ext4_msg(NULL, KERN_WARNING,
2413 				 "mb_optimize_scan should be set to 0 or 1.");
2414 			return -EINVAL;
2415 		}
2416 		return 0;
2417 	}
2418 
2419 	/*
2420 	 * At this point we should only be getting options requiring MOPT_SET,
2421 	 * or MOPT_CLEAR. Anything else is a bug
2422 	 */
2423 	if (m->token == Opt_err) {
2424 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2425 			 param->key);
2426 		WARN_ON(1);
2427 		return -EINVAL;
2428 	}
2429 
2430 	else {
2431 		unsigned int set = 0;
2432 
2433 		if ((param->type == fs_value_is_flag) ||
2434 		    result.uint_32 > 0)
2435 			set = 1;
2436 
2437 		if (m->flags & MOPT_CLEAR)
2438 			set = !set;
2439 		else if (unlikely(!(m->flags & MOPT_SET))) {
2440 			ext4_msg(NULL, KERN_WARNING,
2441 				 "buggy handling of option %s",
2442 				 param->key);
2443 			WARN_ON(1);
2444 			return -EINVAL;
2445 		}
2446 		if (m->flags & MOPT_2) {
2447 			if (set != 0)
2448 				ctx_set_mount_opt2(ctx, m->mount_opt);
2449 			else
2450 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2451 		} else {
2452 			if (set != 0)
2453 				ctx_set_mount_opt(ctx, m->mount_opt);
2454 			else
2455 				ctx_clear_mount_opt(ctx, m->mount_opt);
2456 		}
2457 	}
2458 
2459 	return 0;
2460 }
2461 
2462 static int parse_options(struct fs_context *fc, char *options)
2463 {
2464 	struct fs_parameter param;
2465 	int ret;
2466 	char *key;
2467 
2468 	if (!options)
2469 		return 0;
2470 
2471 	while ((key = strsep(&options, ",")) != NULL) {
2472 		if (*key) {
2473 			size_t v_len = 0;
2474 			char *value = strchr(key, '=');
2475 
2476 			param.type = fs_value_is_flag;
2477 			param.string = NULL;
2478 
2479 			if (value) {
2480 				if (value == key)
2481 					continue;
2482 
2483 				*value++ = 0;
2484 				v_len = strlen(value);
2485 				param.string = kmemdup_nul(value, v_len,
2486 							   GFP_KERNEL);
2487 				if (!param.string)
2488 					return -ENOMEM;
2489 				param.type = fs_value_is_string;
2490 			}
2491 
2492 			param.key = key;
2493 			param.size = v_len;
2494 
2495 			ret = ext4_parse_param(fc, &param);
2496 			kfree(param.string);
2497 			if (ret < 0)
2498 				return ret;
2499 		}
2500 	}
2501 
2502 	ret = ext4_validate_options(fc);
2503 	if (ret < 0)
2504 		return ret;
2505 
2506 	return 0;
2507 }
2508 
2509 static int parse_apply_sb_mount_options(struct super_block *sb,
2510 					struct ext4_fs_context *m_ctx)
2511 {
2512 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2513 	char s_mount_opts[64];
2514 	struct ext4_fs_context *s_ctx = NULL;
2515 	struct fs_context *fc = NULL;
2516 	int ret = -ENOMEM;
2517 
2518 	if (!sbi->s_es->s_mount_opts[0])
2519 		return 0;
2520 
2521 	if (strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts) < 0)
2522 		return -E2BIG;
2523 
2524 	fc = kzalloc_obj(struct fs_context);
2525 	if (!fc)
2526 		return -ENOMEM;
2527 
2528 	s_ctx = kzalloc_obj(struct ext4_fs_context);
2529 	if (!s_ctx)
2530 		goto out_free;
2531 
2532 	fc->fs_private = s_ctx;
2533 	fc->s_fs_info = sbi;
2534 
2535 	ret = parse_options(fc, s_mount_opts);
2536 	if (ret < 0)
2537 		goto parse_failed;
2538 
2539 	ret = ext4_check_opt_consistency(fc, sb);
2540 	if (ret < 0) {
2541 parse_failed:
2542 		ext4_msg(sb, KERN_WARNING,
2543 			 "failed to parse options in superblock: %s",
2544 			 s_mount_opts);
2545 		ret = 0;
2546 		goto out_free;
2547 	}
2548 
2549 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2550 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2551 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2552 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2553 
2554 	ext4_apply_options(fc, sb);
2555 	ret = 0;
2556 
2557 out_free:
2558 	ext4_fc_free(fc);
2559 	kfree(fc);
2560 	return ret;
2561 }
2562 
2563 static void ext4_apply_quota_options(struct fs_context *fc,
2564 				     struct super_block *sb)
2565 {
2566 #ifdef CONFIG_QUOTA
2567 	bool quota_feature = ext4_has_feature_quota(sb);
2568 	struct ext4_fs_context *ctx = fc->fs_private;
2569 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2570 	char *qname;
2571 	int i;
2572 
2573 	if (quota_feature)
2574 		return;
2575 
2576 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2577 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2578 			if (!(ctx->qname_spec & (1 << i)))
2579 				continue;
2580 
2581 			qname = ctx->s_qf_names[i]; /* May be NULL */
2582 			if (qname)
2583 				set_opt(sb, QUOTA);
2584 			ctx->s_qf_names[i] = NULL;
2585 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2586 						lockdep_is_held(&sb->s_umount));
2587 			if (qname)
2588 				kfree_rcu_mightsleep(qname);
2589 		}
2590 	}
2591 
2592 	if (ctx->spec & EXT4_SPEC_JQFMT)
2593 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2594 #endif
2595 }
2596 
2597 /*
2598  * Check quota settings consistency.
2599  */
2600 static int ext4_check_quota_consistency(struct fs_context *fc,
2601 					struct super_block *sb)
2602 {
2603 #ifdef CONFIG_QUOTA
2604 	struct ext4_fs_context *ctx = fc->fs_private;
2605 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2606 	bool quota_feature = ext4_has_feature_quota(sb);
2607 	bool quota_loaded = sb_any_quota_loaded(sb);
2608 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2609 	int quota_flags, i;
2610 
2611 	/*
2612 	 * We do the test below only for project quotas. 'usrquota' and
2613 	 * 'grpquota' mount options are allowed even without quota feature
2614 	 * to support legacy quotas in quota files.
2615 	 */
2616 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2617 	    !ext4_has_feature_project(sb)) {
2618 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2619 			 "Cannot enable project quota enforcement.");
2620 		return -EINVAL;
2621 	}
2622 
2623 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2624 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2625 	if (quota_loaded &&
2626 	    ctx->mask_s_mount_opt & quota_flags &&
2627 	    !ctx_test_mount_opt(ctx, quota_flags))
2628 		goto err_quota_change;
2629 
2630 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2631 
2632 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2633 			if (!(ctx->qname_spec & (1 << i)))
2634 				continue;
2635 
2636 			if (quota_loaded &&
2637 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2638 				goto err_jquota_change;
2639 
2640 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2641 			    strcmp(get_qf_name(sb, sbi, i),
2642 				   ctx->s_qf_names[i]) != 0)
2643 				goto err_jquota_specified;
2644 		}
2645 
2646 		if (quota_feature) {
2647 			ext4_msg(NULL, KERN_INFO,
2648 				 "Journaled quota options ignored when "
2649 				 "QUOTA feature is enabled");
2650 			return 0;
2651 		}
2652 	}
2653 
2654 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2655 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2656 			goto err_jquota_change;
2657 		if (quota_feature) {
2658 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2659 				 "ignored when QUOTA feature is enabled");
2660 			return 0;
2661 		}
2662 	}
2663 
2664 	/* Make sure we don't mix old and new quota format */
2665 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2666 		       ctx->s_qf_names[USRQUOTA]);
2667 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2668 		       ctx->s_qf_names[GRPQUOTA]);
2669 
2670 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2671 		    test_opt(sb, USRQUOTA));
2672 
2673 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2674 		    test_opt(sb, GRPQUOTA));
2675 
2676 	if (usr_qf_name) {
2677 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2678 		usrquota = false;
2679 	}
2680 	if (grp_qf_name) {
2681 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2682 		grpquota = false;
2683 	}
2684 
2685 	if (usr_qf_name || grp_qf_name) {
2686 		if (usrquota || grpquota) {
2687 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2688 				 "format mixing");
2689 			return -EINVAL;
2690 		}
2691 
2692 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2693 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2694 				 "not specified");
2695 			return -EINVAL;
2696 		}
2697 	}
2698 
2699 	return 0;
2700 
2701 err_quota_change:
2702 	ext4_msg(NULL, KERN_ERR,
2703 		 "Cannot change quota options when quota turned on");
2704 	return -EINVAL;
2705 err_jquota_change:
2706 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2707 		 "options when quota turned on");
2708 	return -EINVAL;
2709 err_jquota_specified:
2710 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2711 		 QTYPE2NAME(i));
2712 	return -EINVAL;
2713 #else
2714 	return 0;
2715 #endif
2716 }
2717 
2718 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2719 					    struct super_block *sb)
2720 {
2721 	const struct ext4_fs_context *ctx = fc->fs_private;
2722 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2723 
2724 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2725 		return 0;
2726 
2727 	if (!ext4_has_feature_encrypt(sb)) {
2728 		ext4_msg(NULL, KERN_WARNING,
2729 			 "test_dummy_encryption requires encrypt feature");
2730 		return -EINVAL;
2731 	}
2732 	/*
2733 	 * This mount option is just for testing, and it's not worthwhile to
2734 	 * implement the extra complexity (e.g. RCU protection) that would be
2735 	 * needed to allow it to be set or changed during remount.  We do allow
2736 	 * it to be specified during remount, but only if there is no change.
2737 	 */
2738 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2739 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2740 						 &ctx->dummy_enc_policy))
2741 			return 0;
2742 		ext4_msg(NULL, KERN_WARNING,
2743 			 "Can't set or change test_dummy_encryption on remount");
2744 		return -EINVAL;
2745 	}
2746 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2747 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2748 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2749 						 &ctx->dummy_enc_policy))
2750 			return 0;
2751 		ext4_msg(NULL, KERN_WARNING,
2752 			 "Conflicting test_dummy_encryption options");
2753 		return -EINVAL;
2754 	}
2755 	return 0;
2756 }
2757 
2758 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2759 					     struct super_block *sb)
2760 {
2761 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2762 	    /* if already set, it was already verified to be the same */
2763 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2764 		return;
2765 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2766 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2767 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2768 }
2769 
2770 static int ext4_check_opt_consistency(struct fs_context *fc,
2771 				      struct super_block *sb)
2772 {
2773 	struct ext4_fs_context *ctx = fc->fs_private;
2774 	struct ext4_sb_info *sbi = fc->s_fs_info;
2775 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2776 	int err;
2777 
2778 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2779 		ext4_msg(NULL, KERN_ERR,
2780 			 "Mount option(s) incompatible with ext2");
2781 		return -EINVAL;
2782 	}
2783 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2784 		ext4_msg(NULL, KERN_ERR,
2785 			 "Mount option(s) incompatible with ext3");
2786 		return -EINVAL;
2787 	}
2788 
2789 	if (ctx->s_want_extra_isize >
2790 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2791 		ext4_msg(NULL, KERN_ERR,
2792 			 "Invalid want_extra_isize %d",
2793 			 ctx->s_want_extra_isize);
2794 		return -EINVAL;
2795 	}
2796 
2797 	err = ext4_check_test_dummy_encryption(fc, sb);
2798 	if (err)
2799 		return err;
2800 
2801 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2802 		if (!sbi->s_journal) {
2803 			ext4_msg(NULL, KERN_WARNING,
2804 				 "Remounting file system with no journal "
2805 				 "so ignoring journalled data option");
2806 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2807 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2808 			   test_opt(sb, DATA_FLAGS)) {
2809 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2810 				 "on remount");
2811 			return -EINVAL;
2812 		}
2813 	}
2814 
2815 	if (is_remount) {
2816 		if (!sbi->s_journal &&
2817 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT)) {
2818 			ext4_msg(NULL, KERN_WARNING,
2819 				 "Remounting fs w/o journal so ignoring data_err option");
2820 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT);
2821 		}
2822 
2823 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2824 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2825 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2826 				 "both data=journal and dax");
2827 			return -EINVAL;
2828 		}
2829 
2830 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2831 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2832 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2833 fail_dax_change_remount:
2834 			ext4_msg(NULL, KERN_ERR, "can't change "
2835 				 "dax mount option while remounting");
2836 			return -EINVAL;
2837 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2838 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2839 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2840 			goto fail_dax_change_remount;
2841 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2842 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2843 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2844 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2845 			goto fail_dax_change_remount;
2846 		}
2847 	}
2848 
2849 	return ext4_check_quota_consistency(fc, sb);
2850 }
2851 
2852 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2853 {
2854 	struct ext4_fs_context *ctx = fc->fs_private;
2855 	struct ext4_sb_info *sbi = fc->s_fs_info;
2856 
2857 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2858 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2859 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2860 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2861 	sb->s_flags &= ~ctx->mask_s_flags;
2862 	sb->s_flags |= ctx->vals_s_flags;
2863 
2864 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2865 	APPLY(s_commit_interval);
2866 	APPLY(s_stripe);
2867 	APPLY(s_max_batch_time);
2868 	APPLY(s_min_batch_time);
2869 	APPLY(s_want_extra_isize);
2870 	APPLY(s_inode_readahead_blks);
2871 	APPLY(s_max_dir_size_kb);
2872 	APPLY(s_li_wait_mult);
2873 	APPLY(s_resgid);
2874 	APPLY(s_resuid);
2875 
2876 #ifdef CONFIG_EXT4_DEBUG
2877 	APPLY(s_fc_debug_max_replay);
2878 #endif
2879 
2880 	ext4_apply_quota_options(fc, sb);
2881 	ext4_apply_test_dummy_encryption(ctx, sb);
2882 }
2883 
2884 
2885 static int ext4_validate_options(struct fs_context *fc)
2886 {
2887 #ifdef CONFIG_QUOTA
2888 	struct ext4_fs_context *ctx = fc->fs_private;
2889 	char *usr_qf_name, *grp_qf_name;
2890 
2891 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2892 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2893 
2894 	if (usr_qf_name || grp_qf_name) {
2895 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2896 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2897 
2898 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2899 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2900 
2901 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2902 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2903 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2904 				 "format mixing");
2905 			return -EINVAL;
2906 		}
2907 	}
2908 #endif
2909 	return 1;
2910 }
2911 
2912 static inline void ext4_show_quota_options(struct seq_file *seq,
2913 					   struct super_block *sb)
2914 {
2915 #if defined(CONFIG_QUOTA)
2916 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2917 	char *usr_qf_name, *grp_qf_name;
2918 
2919 	if (sbi->s_jquota_fmt) {
2920 		char *fmtname = "";
2921 
2922 		switch (sbi->s_jquota_fmt) {
2923 		case QFMT_VFS_OLD:
2924 			fmtname = "vfsold";
2925 			break;
2926 		case QFMT_VFS_V0:
2927 			fmtname = "vfsv0";
2928 			break;
2929 		case QFMT_VFS_V1:
2930 			fmtname = "vfsv1";
2931 			break;
2932 		}
2933 		seq_printf(seq, ",jqfmt=%s", fmtname);
2934 	}
2935 
2936 	rcu_read_lock();
2937 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2938 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2939 	if (usr_qf_name)
2940 		seq_show_option(seq, "usrjquota", usr_qf_name);
2941 	if (grp_qf_name)
2942 		seq_show_option(seq, "grpjquota", grp_qf_name);
2943 	rcu_read_unlock();
2944 #endif
2945 }
2946 
2947 static const char *token2str(int token)
2948 {
2949 	const struct fs_parameter_spec *spec;
2950 
2951 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2952 		if (spec->opt == token && !spec->type)
2953 			break;
2954 	return spec->name;
2955 }
2956 
2957 /*
2958  * Show an option if
2959  *  - it's set to a non-default value OR
2960  *  - if the per-sb default is different from the global default
2961  */
2962 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2963 			      int nodefs)
2964 {
2965 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2966 	struct ext4_super_block *es = sbi->s_es;
2967 	int def_errors;
2968 	const struct mount_opts *m;
2969 	char sep = nodefs ? '\n' : ',';
2970 
2971 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2972 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2973 
2974 	if (sbi->s_sb_block != 1)
2975 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2976 
2977 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2978 		int want_set = m->flags & MOPT_SET;
2979 		int opt_2 = m->flags & MOPT_2;
2980 		unsigned int mount_opt, def_mount_opt;
2981 
2982 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2983 		    m->flags & MOPT_SKIP)
2984 			continue;
2985 
2986 		if (opt_2) {
2987 			mount_opt = sbi->s_mount_opt2;
2988 			def_mount_opt = sbi->s_def_mount_opt2;
2989 		} else {
2990 			mount_opt = sbi->s_mount_opt;
2991 			def_mount_opt = sbi->s_def_mount_opt;
2992 		}
2993 		/* skip if same as the default */
2994 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2995 			continue;
2996 		/* select Opt_noFoo vs Opt_Foo */
2997 		if ((want_set &&
2998 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2999 		    (!want_set && (mount_opt & m->mount_opt)))
3000 			continue;
3001 		SEQ_OPTS_PRINT("%s", token2str(m->token));
3002 	}
3003 
3004 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
3005 	    ext4_get_resuid(es) != EXT4_DEF_RESUID)
3006 		SEQ_OPTS_PRINT("resuid=%u",
3007 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
3008 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
3009 	    ext4_get_resgid(es) != EXT4_DEF_RESGID)
3010 		SEQ_OPTS_PRINT("resgid=%u",
3011 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
3012 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
3013 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3014 		SEQ_OPTS_PUTS("errors=remount-ro");
3015 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3016 		SEQ_OPTS_PUTS("errors=continue");
3017 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3018 		SEQ_OPTS_PUTS("errors=panic");
3019 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3020 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3021 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3022 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3023 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3024 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3025 	if (nodefs && sb->s_flags & SB_I_VERSION)
3026 		SEQ_OPTS_PUTS("i_version");
3027 	if (nodefs || sbi->s_stripe)
3028 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3029 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3030 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3031 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3032 			SEQ_OPTS_PUTS("data=journal");
3033 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3034 			SEQ_OPTS_PUTS("data=ordered");
3035 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3036 			SEQ_OPTS_PUTS("data=writeback");
3037 	}
3038 	if (nodefs ||
3039 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3040 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3041 			       sbi->s_inode_readahead_blks);
3042 
3043 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3044 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3045 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3046 	if (nodefs || sbi->s_max_dir_size_kb)
3047 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3048 	if (test_opt(sb, DATA_ERR_ABORT))
3049 		SEQ_OPTS_PUTS("data_err=abort");
3050 
3051 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3052 
3053 	if (sb->s_flags & SB_INLINECRYPT)
3054 		SEQ_OPTS_PUTS("inlinecrypt");
3055 
3056 	if (test_opt(sb, DAX_ALWAYS)) {
3057 		if (IS_EXT2_SB(sb))
3058 			SEQ_OPTS_PUTS("dax");
3059 		else
3060 			SEQ_OPTS_PUTS("dax=always");
3061 	} else if (test_opt2(sb, DAX_NEVER)) {
3062 		SEQ_OPTS_PUTS("dax=never");
3063 	} else if (test_opt2(sb, DAX_INODE)) {
3064 		SEQ_OPTS_PUTS("dax=inode");
3065 	}
3066 
3067 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3068 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3069 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3070 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3071 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3072 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3073 	}
3074 
3075 	if (nodefs && !test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS))
3076 		SEQ_OPTS_PUTS("prefetch_block_bitmaps");
3077 
3078 	if (ext4_emergency_ro(sb))
3079 		SEQ_OPTS_PUTS("emergency_ro");
3080 
3081 	if (ext4_forced_shutdown(sb))
3082 		SEQ_OPTS_PUTS("shutdown");
3083 
3084 	ext4_show_quota_options(seq, sb);
3085 	return 0;
3086 }
3087 
3088 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3089 {
3090 	return _ext4_show_options(seq, root->d_sb, 0);
3091 }
3092 
3093 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3094 {
3095 	struct super_block *sb = seq->private;
3096 	int rc;
3097 
3098 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3099 	rc = _ext4_show_options(seq, sb, 1);
3100 	seq_putc(seq, '\n');
3101 	return rc;
3102 }
3103 
3104 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3105 			    int read_only)
3106 {
3107 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3108 	int err = 0;
3109 
3110 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3111 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3112 			 "forcing read-only mode");
3113 		err = -EROFS;
3114 		goto done;
3115 	}
3116 	if (read_only)
3117 		goto done;
3118 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3119 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3120 			 "running e2fsck is recommended");
3121 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3122 		ext4_msg(sb, KERN_WARNING,
3123 			 "warning: mounting fs with errors, "
3124 			 "running e2fsck is recommended");
3125 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3126 		 le16_to_cpu(es->s_mnt_count) >=
3127 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3128 		ext4_msg(sb, KERN_WARNING,
3129 			 "warning: maximal mount count reached, "
3130 			 "running e2fsck is recommended");
3131 	else if (le32_to_cpu(es->s_checkinterval) &&
3132 		 (ext4_get_tstamp(es, s_lastcheck) +
3133 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3134 		ext4_msg(sb, KERN_WARNING,
3135 			 "warning: checktime reached, "
3136 			 "running e2fsck is recommended");
3137 	if (!sbi->s_journal)
3138 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3139 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3140 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3141 	le16_add_cpu(&es->s_mnt_count, 1);
3142 	ext4_update_tstamp(es, s_mtime);
3143 	if (sbi->s_journal) {
3144 		ext4_set_feature_journal_needs_recovery(sb);
3145 		if (ext4_has_feature_orphan_file(sb))
3146 			ext4_set_feature_orphan_present(sb);
3147 	}
3148 
3149 	err = ext4_commit_super(sb);
3150 done:
3151 	if (test_opt(sb, DEBUG))
3152 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3153 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3154 			sb->s_blocksize,
3155 			sbi->s_groups_count,
3156 			EXT4_BLOCKS_PER_GROUP(sb),
3157 			EXT4_INODES_PER_GROUP(sb),
3158 			sbi->s_mount_opt, sbi->s_mount_opt2);
3159 	return err;
3160 }
3161 
3162 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3163 {
3164 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3165 	struct flex_groups **old_groups, **new_groups;
3166 	int size, i, j;
3167 
3168 	if (!sbi->s_log_groups_per_flex)
3169 		return 0;
3170 
3171 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3172 	if (size <= sbi->s_flex_groups_allocated)
3173 		return 0;
3174 
3175 	new_groups = kvzalloc(roundup_pow_of_two(size *
3176 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3177 	if (!new_groups) {
3178 		ext4_msg(sb, KERN_ERR,
3179 			 "not enough memory for %d flex group pointers", size);
3180 		return -ENOMEM;
3181 	}
3182 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3183 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3184 					 sizeof(struct flex_groups)),
3185 					 GFP_KERNEL);
3186 		if (!new_groups[i]) {
3187 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3188 				kvfree(new_groups[j]);
3189 			kvfree(new_groups);
3190 			ext4_msg(sb, KERN_ERR,
3191 				 "not enough memory for %d flex groups", size);
3192 			return -ENOMEM;
3193 		}
3194 	}
3195 	rcu_read_lock();
3196 	old_groups = rcu_dereference(sbi->s_flex_groups);
3197 	if (old_groups)
3198 		memcpy(new_groups, old_groups,
3199 		       (sbi->s_flex_groups_allocated *
3200 			sizeof(struct flex_groups *)));
3201 	rcu_read_unlock();
3202 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3203 	sbi->s_flex_groups_allocated = size;
3204 	if (old_groups)
3205 		ext4_kvfree_array_rcu(old_groups);
3206 	return 0;
3207 }
3208 
3209 static int ext4_fill_flex_info(struct super_block *sb)
3210 {
3211 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3212 	struct ext4_group_desc *gdp = NULL;
3213 	struct flex_groups *fg;
3214 	ext4_group_t flex_group;
3215 	int i, err;
3216 
3217 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3218 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3219 		sbi->s_log_groups_per_flex = 0;
3220 		return 1;
3221 	}
3222 
3223 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3224 	if (err)
3225 		goto failed;
3226 
3227 	for (i = 0; i < sbi->s_groups_count; i++) {
3228 		gdp = ext4_get_group_desc(sb, i, NULL);
3229 
3230 		flex_group = ext4_flex_group(sbi, i);
3231 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3232 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3233 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3234 			     &fg->free_clusters);
3235 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3236 	}
3237 
3238 	return 1;
3239 failed:
3240 	return 0;
3241 }
3242 
3243 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3244 				   struct ext4_group_desc *gdp)
3245 {
3246 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3247 	__u16 crc = 0;
3248 	__le32 le_group = cpu_to_le32(block_group);
3249 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3250 
3251 	if (ext4_has_feature_metadata_csum(sbi->s_sb)) {
3252 		/* Use new metadata_csum algorithm */
3253 		__u32 csum32;
3254 		__u16 dummy_csum = 0;
3255 
3256 		csum32 = ext4_chksum(sbi->s_csum_seed, (__u8 *)&le_group,
3257 				     sizeof(le_group));
3258 		csum32 = ext4_chksum(csum32, (__u8 *)gdp, offset);
3259 		csum32 = ext4_chksum(csum32, (__u8 *)&dummy_csum,
3260 				     sizeof(dummy_csum));
3261 		offset += sizeof(dummy_csum);
3262 		if (offset < sbi->s_desc_size)
3263 			csum32 = ext4_chksum(csum32, (__u8 *)gdp + offset,
3264 					     sbi->s_desc_size - offset);
3265 
3266 		crc = csum32 & 0xFFFF;
3267 		goto out;
3268 	}
3269 
3270 	/* old crc16 code */
3271 	if (!ext4_has_feature_gdt_csum(sb))
3272 		return 0;
3273 
3274 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3275 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3276 	crc = crc16(crc, (__u8 *)gdp, offset);
3277 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3278 	/* for checksum of struct ext4_group_desc do the rest...*/
3279 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3280 		crc = crc16(crc, (__u8 *)gdp + offset,
3281 			    sbi->s_desc_size - offset);
3282 
3283 out:
3284 	return cpu_to_le16(crc);
3285 }
3286 
3287 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3288 				struct ext4_group_desc *gdp)
3289 {
3290 	if (ext4_has_group_desc_csum(sb) &&
3291 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3292 		return 0;
3293 
3294 	return 1;
3295 }
3296 
3297 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3298 			      struct ext4_group_desc *gdp)
3299 {
3300 	if (!ext4_has_group_desc_csum(sb))
3301 		return;
3302 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3303 }
3304 
3305 /* Called at mount-time, super-block is locked */
3306 static int ext4_check_descriptors(struct super_block *sb,
3307 				  ext4_fsblk_t sb_block,
3308 				  ext4_group_t *first_not_zeroed)
3309 {
3310 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3311 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3312 	ext4_fsblk_t last_block;
3313 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3314 	ext4_fsblk_t block_bitmap;
3315 	ext4_fsblk_t inode_bitmap;
3316 	ext4_fsblk_t inode_table;
3317 	int flexbg_flag = 0;
3318 	ext4_group_t i, grp = sbi->s_groups_count;
3319 
3320 	if (ext4_has_feature_flex_bg(sb))
3321 		flexbg_flag = 1;
3322 
3323 	ext4_debug("Checking group descriptors");
3324 
3325 	for (i = 0; i < sbi->s_groups_count; i++) {
3326 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3327 
3328 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3329 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3330 		else
3331 			last_block = first_block +
3332 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3333 
3334 		if ((grp == sbi->s_groups_count) &&
3335 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3336 			grp = i;
3337 
3338 		block_bitmap = ext4_block_bitmap(sb, gdp);
3339 		if (block_bitmap == sb_block) {
3340 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3341 				 "Block bitmap for group %u overlaps "
3342 				 "superblock", i);
3343 			if (!sb_rdonly(sb))
3344 				return 0;
3345 		}
3346 		if (block_bitmap >= sb_block + 1 &&
3347 		    block_bitmap <= last_bg_block) {
3348 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3349 				 "Block bitmap for group %u overlaps "
3350 				 "block group descriptors", i);
3351 			if (!sb_rdonly(sb))
3352 				return 0;
3353 		}
3354 		if (block_bitmap < first_block || block_bitmap > last_block) {
3355 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3356 			       "Block bitmap for group %u not in group "
3357 			       "(block %llu)!", i, block_bitmap);
3358 			return 0;
3359 		}
3360 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3361 		if (inode_bitmap == sb_block) {
3362 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3363 				 "Inode bitmap for group %u overlaps "
3364 				 "superblock", i);
3365 			if (!sb_rdonly(sb))
3366 				return 0;
3367 		}
3368 		if (inode_bitmap >= sb_block + 1 &&
3369 		    inode_bitmap <= last_bg_block) {
3370 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3371 				 "Inode bitmap for group %u overlaps "
3372 				 "block group descriptors", i);
3373 			if (!sb_rdonly(sb))
3374 				return 0;
3375 		}
3376 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3377 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3378 			       "Inode bitmap for group %u not in group "
3379 			       "(block %llu)!", i, inode_bitmap);
3380 			return 0;
3381 		}
3382 		inode_table = ext4_inode_table(sb, gdp);
3383 		if (inode_table == sb_block) {
3384 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3385 				 "Inode table for group %u overlaps "
3386 				 "superblock", i);
3387 			if (!sb_rdonly(sb))
3388 				return 0;
3389 		}
3390 		if (inode_table >= sb_block + 1 &&
3391 		    inode_table <= last_bg_block) {
3392 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3393 				 "Inode table for group %u overlaps "
3394 				 "block group descriptors", i);
3395 			if (!sb_rdonly(sb))
3396 				return 0;
3397 		}
3398 		if (inode_table < first_block ||
3399 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3400 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3401 			       "Inode table for group %u not in group "
3402 			       "(block %llu)!", i, inode_table);
3403 			return 0;
3404 		}
3405 		ext4_lock_group(sb, i);
3406 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3407 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3408 				 "Checksum for group %u failed (%u!=%u)",
3409 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3410 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3411 			if (!sb_rdonly(sb)) {
3412 				ext4_unlock_group(sb, i);
3413 				return 0;
3414 			}
3415 		}
3416 		ext4_unlock_group(sb, i);
3417 		if (!flexbg_flag)
3418 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3419 	}
3420 	if (NULL != first_not_zeroed)
3421 		*first_not_zeroed = grp;
3422 	return 1;
3423 }
3424 
3425 /*
3426  * Maximal extent format file size.
3427  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3428  * extent format containers, within a sector_t, and within i_blocks
3429  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3430  * so that won't be a limiting factor.
3431  *
3432  * However there is other limiting factor. We do store extents in the form
3433  * of starting block and length, hence the resulting length of the extent
3434  * covering maximum file size must fit into on-disk format containers as
3435  * well. Given that length is always by 1 unit bigger than max unit (because
3436  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3437  *
3438  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3439  */
3440 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3441 {
3442 	loff_t res;
3443 	loff_t upper_limit = MAX_LFS_FILESIZE;
3444 
3445 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3446 
3447 	if (!has_huge_files) {
3448 		upper_limit = (1LL << 32) - 1;
3449 
3450 		/* total blocks in file system block size */
3451 		upper_limit >>= (blkbits - 9);
3452 		upper_limit <<= blkbits;
3453 	}
3454 
3455 	/*
3456 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3457 	 * by one fs block, so ee_len can cover the extent of maximum file
3458 	 * size
3459 	 */
3460 	res = (1LL << 32) - 1;
3461 	res <<= blkbits;
3462 
3463 	/* Sanity check against vm- & vfs- imposed limits */
3464 	if (res > upper_limit)
3465 		res = upper_limit;
3466 
3467 	return res;
3468 }
3469 
3470 /*
3471  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3472  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3473  * We need to be 1 filesystem block less than the 2^48 sector limit.
3474  */
3475 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3476 {
3477 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3478 	int meta_blocks;
3479 	unsigned int ppb = 1 << (bits - 2);
3480 
3481 	/*
3482 	 * This is calculated to be the largest file size for a dense, block
3483 	 * mapped file such that the file's total number of 512-byte sectors,
3484 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3485 	 *
3486 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3487 	 * number of 512-byte sectors of the file.
3488 	 */
3489 	if (!has_huge_files) {
3490 		/*
3491 		 * !has_huge_files or implies that the inode i_block field
3492 		 * represents total file blocks in 2^32 512-byte sectors ==
3493 		 * size of vfs inode i_blocks * 8
3494 		 */
3495 		upper_limit = (1LL << 32) - 1;
3496 
3497 		/* total blocks in file system block size */
3498 		upper_limit >>= (bits - 9);
3499 
3500 	} else {
3501 		/*
3502 		 * We use 48 bit ext4_inode i_blocks
3503 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3504 		 * represent total number of blocks in
3505 		 * file system block size
3506 		 */
3507 		upper_limit = (1LL << 48) - 1;
3508 
3509 	}
3510 
3511 	/* Compute how many blocks we can address by block tree */
3512 	res += ppb;
3513 	res += ppb * ppb;
3514 	res += ((loff_t)ppb) * ppb * ppb;
3515 	/* Compute how many metadata blocks are needed */
3516 	meta_blocks = 1;
3517 	meta_blocks += 1 + ppb;
3518 	meta_blocks += 1 + ppb + ppb * ppb;
3519 	/* Does block tree limit file size? */
3520 	if (res + meta_blocks <= upper_limit)
3521 		goto check_lfs;
3522 
3523 	res = upper_limit;
3524 	/* How many metadata blocks are needed for addressing upper_limit? */
3525 	upper_limit -= EXT4_NDIR_BLOCKS;
3526 	/* indirect blocks */
3527 	meta_blocks = 1;
3528 	upper_limit -= ppb;
3529 	/* double indirect blocks */
3530 	if (upper_limit < ppb * ppb) {
3531 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3532 		res -= meta_blocks;
3533 		goto check_lfs;
3534 	}
3535 	meta_blocks += 1 + ppb;
3536 	upper_limit -= ppb * ppb;
3537 	/* tripple indirect blocks for the rest */
3538 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3539 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3540 	res -= meta_blocks;
3541 check_lfs:
3542 	res <<= bits;
3543 	if (res > MAX_LFS_FILESIZE)
3544 		res = MAX_LFS_FILESIZE;
3545 
3546 	return res;
3547 }
3548 
3549 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3550 				   ext4_fsblk_t logical_sb_block, int nr)
3551 {
3552 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3553 	ext4_group_t bg, first_meta_bg;
3554 	int has_super = 0;
3555 
3556 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3557 
3558 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3559 		return logical_sb_block + nr + 1;
3560 	bg = sbi->s_desc_per_block * nr;
3561 	if (ext4_bg_has_super(sb, bg))
3562 		has_super = 1;
3563 
3564 	/*
3565 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3566 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3567 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3568 	 * compensate.
3569 	 */
3570 	if (sb->s_blocksize == 1024 && nr == 0 &&
3571 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3572 		has_super++;
3573 
3574 	return (has_super + ext4_group_first_block_no(sb, bg));
3575 }
3576 
3577 /**
3578  * ext4_get_stripe_size: Get the stripe size.
3579  * @sbi: In memory super block info
3580  *
3581  * If we have specified it via mount option, then
3582  * use the mount option value. If the value specified at mount time is
3583  * greater than the blocks per group use the super block value.
3584  * If the super block value is greater than blocks per group return 0.
3585  * Allocator needs it be less than blocks per group.
3586  *
3587  */
3588 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3589 {
3590 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3591 	unsigned long stripe_width =
3592 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3593 	int ret;
3594 
3595 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3596 		ret = sbi->s_stripe;
3597 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3598 		ret = stripe_width;
3599 	else if (stride && stride <= sbi->s_blocks_per_group)
3600 		ret = stride;
3601 	else
3602 		ret = 0;
3603 
3604 	/*
3605 	 * If the stripe width is 1, this makes no sense and
3606 	 * we set it to 0 to turn off stripe handling code.
3607 	 */
3608 	if (ret <= 1)
3609 		ret = 0;
3610 
3611 	return ret;
3612 }
3613 
3614 /*
3615  * Check whether this filesystem can be mounted based on
3616  * the features present and the RDONLY/RDWR mount requested.
3617  * Returns 1 if this filesystem can be mounted as requested,
3618  * 0 if it cannot be.
3619  */
3620 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3621 {
3622 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3623 		ext4_msg(sb, KERN_ERR,
3624 			"Couldn't mount because of "
3625 			"unsupported optional features (%x)",
3626 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3627 			~EXT4_FEATURE_INCOMPAT_SUPP));
3628 		return 0;
3629 	}
3630 
3631 	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
3632 		ext4_msg(sb, KERN_ERR,
3633 			 "Filesystem with casefold feature cannot be "
3634 			 "mounted without CONFIG_UNICODE");
3635 		return 0;
3636 	}
3637 
3638 	if (readonly)
3639 		return 1;
3640 
3641 	if (ext4_has_feature_readonly(sb)) {
3642 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3643 		sb->s_flags |= SB_RDONLY;
3644 		return 1;
3645 	}
3646 
3647 	/* Check that feature set is OK for a read-write mount */
3648 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3649 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3650 			 "unsupported optional features (%x)",
3651 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3652 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3653 		return 0;
3654 	}
3655 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3656 		ext4_msg(sb, KERN_ERR,
3657 			 "Can't support bigalloc feature without "
3658 			 "extents feature\n");
3659 		return 0;
3660 	}
3661 	if (ext4_has_feature_bigalloc(sb) &&
3662 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
3663 		ext4_msg(sb, KERN_WARNING,
3664 			 "bad geometry: bigalloc file system with non-zero "
3665 			 "first_data_block\n");
3666 		return 0;
3667 	}
3668 
3669 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3670 	if (!readonly && (ext4_has_feature_quota(sb) ||
3671 			  ext4_has_feature_project(sb))) {
3672 		ext4_msg(sb, KERN_ERR,
3673 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3674 		return 0;
3675 	}
3676 #endif  /* CONFIG_QUOTA */
3677 	return 1;
3678 }
3679 
3680 /*
3681  * This function is called once a day by default if we have errors logged
3682  * on the file system.
3683  * Use the err_report_sec sysfs attribute to disable or adjust its call
3684  * freequency.
3685  */
3686 void print_daily_error_info(struct timer_list *t)
3687 {
3688 	struct ext4_sb_info *sbi = timer_container_of(sbi, t, s_err_report);
3689 	struct super_block *sb = sbi->s_sb;
3690 	struct ext4_super_block *es = sbi->s_es;
3691 
3692 	if (es->s_error_count)
3693 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3694 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3695 			 le32_to_cpu(es->s_error_count));
3696 	if (es->s_first_error_time) {
3697 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3698 		       sb->s_id,
3699 		       ext4_get_tstamp(es, s_first_error_time),
3700 		       (int) sizeof(es->s_first_error_func),
3701 		       es->s_first_error_func,
3702 		       le32_to_cpu(es->s_first_error_line));
3703 		if (es->s_first_error_ino)
3704 			printk(KERN_CONT ": inode %u",
3705 			       le32_to_cpu(es->s_first_error_ino));
3706 		if (es->s_first_error_block)
3707 			printk(KERN_CONT ": block %llu", (unsigned long long)
3708 			       le64_to_cpu(es->s_first_error_block));
3709 		printk(KERN_CONT "\n");
3710 	}
3711 	if (es->s_last_error_time) {
3712 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3713 		       sb->s_id,
3714 		       ext4_get_tstamp(es, s_last_error_time),
3715 		       (int) sizeof(es->s_last_error_func),
3716 		       es->s_last_error_func,
3717 		       le32_to_cpu(es->s_last_error_line));
3718 		if (es->s_last_error_ino)
3719 			printk(KERN_CONT ": inode %u",
3720 			       le32_to_cpu(es->s_last_error_ino));
3721 		if (es->s_last_error_block)
3722 			printk(KERN_CONT ": block %llu", (unsigned long long)
3723 			       le64_to_cpu(es->s_last_error_block));
3724 		printk(KERN_CONT "\n");
3725 	}
3726 
3727 	if (sbi->s_err_report_sec)
3728 		mod_timer(&sbi->s_err_report, jiffies + secs_to_jiffies(sbi->s_err_report_sec));
3729 }
3730 
3731 /* Find next suitable group and run ext4_init_inode_table */
3732 static int ext4_run_li_request(struct ext4_li_request *elr)
3733 {
3734 	struct ext4_group_desc *gdp = NULL;
3735 	struct super_block *sb = elr->lr_super;
3736 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3737 	ext4_group_t group = elr->lr_next_group;
3738 	unsigned int prefetch_ios = 0;
3739 	int ret = 0;
3740 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3741 	u64 start_time;
3742 
3743 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3744 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3745 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3746 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3747 		if (group >= elr->lr_next_group) {
3748 			ret = 1;
3749 			if (elr->lr_first_not_zeroed != ngroups &&
3750 			    !ext4_emergency_state(sb) && !sb_rdonly(sb) &&
3751 			    test_opt(sb, INIT_INODE_TABLE)) {
3752 				elr->lr_next_group = elr->lr_first_not_zeroed;
3753 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3754 				ret = 0;
3755 			}
3756 		}
3757 		return ret;
3758 	}
3759 
3760 	for (; group < ngroups; group++) {
3761 		gdp = ext4_get_group_desc(sb, group, NULL);
3762 		if (!gdp) {
3763 			ret = 1;
3764 			break;
3765 		}
3766 
3767 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3768 			break;
3769 	}
3770 
3771 	if (group >= ngroups)
3772 		ret = 1;
3773 
3774 	if (!ret) {
3775 		start_time = ktime_get_ns();
3776 		ret = ext4_init_inode_table(sb, group,
3777 					    elr->lr_timeout ? 0 : 1);
3778 		trace_ext4_lazy_itable_init(sb, group);
3779 		if (elr->lr_timeout == 0) {
3780 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_ns() - start_time) *
3781 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3782 		}
3783 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3784 		elr->lr_next_group = group + 1;
3785 	}
3786 	return ret;
3787 }
3788 
3789 /*
3790  * Remove lr_request from the list_request and free the
3791  * request structure. Should be called with li_list_mtx held
3792  */
3793 static void ext4_remove_li_request(struct ext4_li_request *elr)
3794 {
3795 	if (!elr)
3796 		return;
3797 
3798 	list_del(&elr->lr_request);
3799 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3800 	kfree(elr);
3801 }
3802 
3803 static void ext4_unregister_li_request(struct super_block *sb)
3804 {
3805 	mutex_lock(&ext4_li_mtx);
3806 	if (!ext4_li_info) {
3807 		mutex_unlock(&ext4_li_mtx);
3808 		return;
3809 	}
3810 
3811 	mutex_lock(&ext4_li_info->li_list_mtx);
3812 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3813 	mutex_unlock(&ext4_li_info->li_list_mtx);
3814 	mutex_unlock(&ext4_li_mtx);
3815 }
3816 
3817 static struct task_struct *ext4_lazyinit_task;
3818 
3819 /*
3820  * This is the function where ext4lazyinit thread lives. It walks
3821  * through the request list searching for next scheduled filesystem.
3822  * When such a fs is found, run the lazy initialization request
3823  * (ext4_rn_li_request) and keep track of the time spend in this
3824  * function. Based on that time we compute next schedule time of
3825  * the request. When walking through the list is complete, compute
3826  * next waking time and put itself into sleep.
3827  */
3828 static int ext4_lazyinit_thread(void *arg)
3829 {
3830 	struct ext4_lazy_init *eli = arg;
3831 	struct list_head *pos, *n;
3832 	struct ext4_li_request *elr;
3833 	unsigned long next_wakeup, cur;
3834 
3835 	BUG_ON(NULL == eli);
3836 	set_freezable();
3837 
3838 cont_thread:
3839 	while (true) {
3840 		bool next_wakeup_initialized = false;
3841 
3842 		next_wakeup = 0;
3843 		mutex_lock(&eli->li_list_mtx);
3844 		if (list_empty(&eli->li_request_list)) {
3845 			mutex_unlock(&eli->li_list_mtx);
3846 			goto exit_thread;
3847 		}
3848 		list_for_each_safe(pos, n, &eli->li_request_list) {
3849 			int err = 0;
3850 			int progress = 0;
3851 			elr = list_entry(pos, struct ext4_li_request,
3852 					 lr_request);
3853 
3854 			if (time_before(jiffies, elr->lr_next_sched)) {
3855 				if (!next_wakeup_initialized ||
3856 				    time_before(elr->lr_next_sched, next_wakeup)) {
3857 					next_wakeup = elr->lr_next_sched;
3858 					next_wakeup_initialized = true;
3859 				}
3860 				continue;
3861 			}
3862 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3863 				if (sb_start_write_trylock(elr->lr_super)) {
3864 					progress = 1;
3865 					/*
3866 					 * We hold sb->s_umount, sb can not
3867 					 * be removed from the list, it is
3868 					 * now safe to drop li_list_mtx
3869 					 */
3870 					mutex_unlock(&eli->li_list_mtx);
3871 					err = ext4_run_li_request(elr);
3872 					sb_end_write(elr->lr_super);
3873 					mutex_lock(&eli->li_list_mtx);
3874 					n = pos->next;
3875 				}
3876 				up_read((&elr->lr_super->s_umount));
3877 			}
3878 			/* error, remove the lazy_init job */
3879 			if (err) {
3880 				ext4_remove_li_request(elr);
3881 				continue;
3882 			}
3883 			if (!progress) {
3884 				elr->lr_next_sched = jiffies +
3885 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3886 			}
3887 			if (!next_wakeup_initialized ||
3888 			    time_before(elr->lr_next_sched, next_wakeup)) {
3889 				next_wakeup = elr->lr_next_sched;
3890 				next_wakeup_initialized = true;
3891 			}
3892 		}
3893 		mutex_unlock(&eli->li_list_mtx);
3894 
3895 		try_to_freeze();
3896 
3897 		cur = jiffies;
3898 		if (!next_wakeup_initialized || time_after_eq(cur, next_wakeup)) {
3899 			cond_resched();
3900 			continue;
3901 		}
3902 
3903 		schedule_timeout_interruptible(next_wakeup - cur);
3904 
3905 		if (kthread_should_stop()) {
3906 			ext4_clear_request_list();
3907 			goto exit_thread;
3908 		}
3909 	}
3910 
3911 exit_thread:
3912 	/*
3913 	 * It looks like the request list is empty, but we need
3914 	 * to check it under the li_list_mtx lock, to prevent any
3915 	 * additions into it, and of course we should lock ext4_li_mtx
3916 	 * to atomically free the list and ext4_li_info, because at
3917 	 * this point another ext4 filesystem could be registering
3918 	 * new one.
3919 	 */
3920 	mutex_lock(&ext4_li_mtx);
3921 	mutex_lock(&eli->li_list_mtx);
3922 	if (!list_empty(&eli->li_request_list)) {
3923 		mutex_unlock(&eli->li_list_mtx);
3924 		mutex_unlock(&ext4_li_mtx);
3925 		goto cont_thread;
3926 	}
3927 	mutex_unlock(&eli->li_list_mtx);
3928 	kfree(ext4_li_info);
3929 	ext4_li_info = NULL;
3930 	mutex_unlock(&ext4_li_mtx);
3931 
3932 	return 0;
3933 }
3934 
3935 static void ext4_clear_request_list(void)
3936 {
3937 	struct list_head *pos, *n;
3938 	struct ext4_li_request *elr;
3939 
3940 	mutex_lock(&ext4_li_info->li_list_mtx);
3941 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3942 		elr = list_entry(pos, struct ext4_li_request,
3943 				 lr_request);
3944 		ext4_remove_li_request(elr);
3945 	}
3946 	mutex_unlock(&ext4_li_info->li_list_mtx);
3947 }
3948 
3949 static int ext4_run_lazyinit_thread(void)
3950 {
3951 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3952 					 ext4_li_info, "ext4lazyinit");
3953 	if (IS_ERR(ext4_lazyinit_task)) {
3954 		int err = PTR_ERR(ext4_lazyinit_task);
3955 		ext4_clear_request_list();
3956 		kfree(ext4_li_info);
3957 		ext4_li_info = NULL;
3958 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3959 				 "initialization thread\n",
3960 				 err);
3961 		return err;
3962 	}
3963 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3964 	return 0;
3965 }
3966 
3967 /*
3968  * Check whether it make sense to run itable init. thread or not.
3969  * If there is at least one uninitialized inode table, return
3970  * corresponding group number, else the loop goes through all
3971  * groups and return total number of groups.
3972  */
3973 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3974 {
3975 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3976 	struct ext4_group_desc *gdp = NULL;
3977 
3978 	if (!ext4_has_group_desc_csum(sb))
3979 		return ngroups;
3980 
3981 	for (group = 0; group < ngroups; group++) {
3982 		gdp = ext4_get_group_desc(sb, group, NULL);
3983 		if (!gdp)
3984 			continue;
3985 
3986 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3987 			break;
3988 	}
3989 
3990 	return group;
3991 }
3992 
3993 static int ext4_li_info_new(void)
3994 {
3995 	struct ext4_lazy_init *eli = NULL;
3996 
3997 	eli = kzalloc_obj(*eli);
3998 	if (!eli)
3999 		return -ENOMEM;
4000 
4001 	INIT_LIST_HEAD(&eli->li_request_list);
4002 	mutex_init(&eli->li_list_mtx);
4003 
4004 	eli->li_state |= EXT4_LAZYINIT_QUIT;
4005 
4006 	ext4_li_info = eli;
4007 
4008 	return 0;
4009 }
4010 
4011 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
4012 					    ext4_group_t start)
4013 {
4014 	struct ext4_li_request *elr;
4015 
4016 	elr = kzalloc_obj(*elr);
4017 	if (!elr)
4018 		return NULL;
4019 
4020 	elr->lr_super = sb;
4021 	elr->lr_first_not_zeroed = start;
4022 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
4023 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
4024 		elr->lr_next_group = start;
4025 	} else {
4026 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
4027 	}
4028 
4029 	/*
4030 	 * Randomize first schedule time of the request to
4031 	 * spread the inode table initialization requests
4032 	 * better.
4033 	 */
4034 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
4035 	return elr;
4036 }
4037 
4038 int ext4_register_li_request(struct super_block *sb,
4039 			     ext4_group_t first_not_zeroed)
4040 {
4041 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4042 	struct ext4_li_request *elr = NULL;
4043 	ext4_group_t ngroups = sbi->s_groups_count;
4044 	int ret = 0;
4045 
4046 	mutex_lock(&ext4_li_mtx);
4047 	if (sbi->s_li_request != NULL) {
4048 		/*
4049 		 * Reset timeout so it can be computed again, because
4050 		 * s_li_wait_mult might have changed.
4051 		 */
4052 		sbi->s_li_request->lr_timeout = 0;
4053 		goto out;
4054 	}
4055 
4056 	if (ext4_emergency_state(sb) || sb_rdonly(sb) ||
4057 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4058 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4059 		goto out;
4060 
4061 	elr = ext4_li_request_new(sb, first_not_zeroed);
4062 	if (!elr) {
4063 		ret = -ENOMEM;
4064 		goto out;
4065 	}
4066 
4067 	if (NULL == ext4_li_info) {
4068 		ret = ext4_li_info_new();
4069 		if (ret)
4070 			goto out;
4071 	}
4072 
4073 	mutex_lock(&ext4_li_info->li_list_mtx);
4074 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4075 	mutex_unlock(&ext4_li_info->li_list_mtx);
4076 
4077 	sbi->s_li_request = elr;
4078 	/*
4079 	 * set elr to NULL here since it has been inserted to
4080 	 * the request_list and the removal and free of it is
4081 	 * handled by ext4_clear_request_list from now on.
4082 	 */
4083 	elr = NULL;
4084 
4085 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4086 		ret = ext4_run_lazyinit_thread();
4087 		if (ret)
4088 			goto out;
4089 	}
4090 out:
4091 	mutex_unlock(&ext4_li_mtx);
4092 	if (ret)
4093 		kfree(elr);
4094 	return ret;
4095 }
4096 
4097 /*
4098  * We do not need to lock anything since this is called on
4099  * module unload.
4100  */
4101 static void ext4_destroy_lazyinit_thread(void)
4102 {
4103 	/*
4104 	 * If thread exited earlier
4105 	 * there's nothing to be done.
4106 	 */
4107 	if (!ext4_li_info || !ext4_lazyinit_task)
4108 		return;
4109 
4110 	kthread_stop(ext4_lazyinit_task);
4111 }
4112 
4113 static int set_journal_csum_feature_set(struct super_block *sb)
4114 {
4115 	int ret = 1;
4116 	int compat, incompat;
4117 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4118 
4119 	if (ext4_has_feature_metadata_csum(sb)) {
4120 		/* journal checksum v3 */
4121 		compat = 0;
4122 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4123 	} else {
4124 		/* journal checksum v1 */
4125 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4126 		incompat = 0;
4127 	}
4128 
4129 	jbd2_journal_clear_features(sbi->s_journal,
4130 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4131 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4132 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4133 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4134 		ret = jbd2_journal_set_features(sbi->s_journal,
4135 				compat, 0,
4136 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4137 				incompat);
4138 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4139 		ret = jbd2_journal_set_features(sbi->s_journal,
4140 				compat, 0,
4141 				incompat);
4142 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4143 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4144 	} else {
4145 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4146 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4147 	}
4148 
4149 	return ret;
4150 }
4151 
4152 /*
4153  * Note: calculating the overhead so we can be compatible with
4154  * historical BSD practice is quite difficult in the face of
4155  * clusters/bigalloc.  This is because multiple metadata blocks from
4156  * different block group can end up in the same allocation cluster.
4157  * Calculating the exact overhead in the face of clustered allocation
4158  * requires either O(all block bitmaps) in memory or O(number of block
4159  * groups**2) in time.  We will still calculate the superblock for
4160  * older file systems --- and if we come across with a bigalloc file
4161  * system with zero in s_overhead_clusters the estimate will be close to
4162  * correct especially for very large cluster sizes --- but for newer
4163  * file systems, it's better to calculate this figure once at mkfs
4164  * time, and store it in the superblock.  If the superblock value is
4165  * present (even for non-bigalloc file systems), we will use it.
4166  */
4167 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4168 			  char *buf)
4169 {
4170 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4171 	struct ext4_group_desc	*gdp;
4172 	ext4_fsblk_t		first_block, last_block, b;
4173 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4174 	int			s, j, count = 0;
4175 	int			has_super = ext4_bg_has_super(sb, grp);
4176 
4177 	if (!ext4_has_feature_bigalloc(sb))
4178 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4179 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4180 			sbi->s_itb_per_group + 2);
4181 
4182 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4183 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4184 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4185 	for (i = 0; i < ngroups; i++) {
4186 		gdp = ext4_get_group_desc(sb, i, NULL);
4187 		b = ext4_block_bitmap(sb, gdp);
4188 		if (b >= first_block && b <= last_block) {
4189 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4190 			count++;
4191 		}
4192 		b = ext4_inode_bitmap(sb, gdp);
4193 		if (b >= first_block && b <= last_block) {
4194 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4195 			count++;
4196 		}
4197 		b = ext4_inode_table(sb, gdp);
4198 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4199 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4200 				int c = EXT4_B2C(sbi, b - first_block);
4201 				ext4_set_bit(c, buf);
4202 				count++;
4203 			}
4204 		if (i != grp)
4205 			continue;
4206 		s = 0;
4207 		if (ext4_bg_has_super(sb, grp)) {
4208 			ext4_set_bit(s++, buf);
4209 			count++;
4210 		}
4211 		j = ext4_bg_num_gdb(sb, grp);
4212 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4213 			ext4_error(sb, "Invalid number of block group "
4214 				   "descriptor blocks: %d", j);
4215 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4216 		}
4217 		count += j;
4218 		for (; j > 0; j--)
4219 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4220 	}
4221 	if (!count)
4222 		return 0;
4223 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4224 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4225 }
4226 
4227 /*
4228  * Compute the overhead and stash it in sbi->s_overhead
4229  */
4230 int ext4_calculate_overhead(struct super_block *sb)
4231 {
4232 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4233 	struct ext4_super_block *es = sbi->s_es;
4234 	struct inode *j_inode;
4235 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4236 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4237 	ext4_fsblk_t overhead = 0;
4238 	char *buf = kvmalloc(sb->s_blocksize, GFP_NOFS | __GFP_ZERO);
4239 
4240 	if (!buf)
4241 		return -ENOMEM;
4242 
4243 	/*
4244 	 * Compute the overhead (FS structures).  This is constant
4245 	 * for a given filesystem unless the number of block groups
4246 	 * changes so we cache the previous value until it does.
4247 	 */
4248 
4249 	/*
4250 	 * All of the blocks before first_data_block are overhead
4251 	 */
4252 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4253 
4254 	/*
4255 	 * Add the overhead found in each block group
4256 	 */
4257 	for (i = 0; i < ngroups; i++) {
4258 		int blks;
4259 
4260 		blks = count_overhead(sb, i, buf);
4261 		overhead += blks;
4262 		if (blks)
4263 			memset(buf, 0, sb->s_blocksize);
4264 		cond_resched();
4265 	}
4266 
4267 	/*
4268 	 * Add the internal journal blocks whether the journal has been
4269 	 * loaded or not
4270 	 */
4271 	if (sbi->s_journal && !sbi->s_journal_bdev_file)
4272 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4273 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4274 		/* j_inum for internal journal is non-zero */
4275 		j_inode = ext4_get_journal_inode(sb, j_inum);
4276 		if (!IS_ERR(j_inode)) {
4277 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4278 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4279 			iput(j_inode);
4280 		} else {
4281 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4282 		}
4283 	}
4284 	sbi->s_overhead = overhead;
4285 	smp_wmb();
4286 	kvfree(buf);
4287 	return 0;
4288 }
4289 
4290 static void ext4_set_resv_clusters(struct super_block *sb)
4291 {
4292 	ext4_fsblk_t resv_clusters;
4293 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4294 
4295 	/*
4296 	 * There's no need to reserve anything when we aren't using extents.
4297 	 * The space estimates are exact, there are no unwritten extents,
4298 	 * hole punching doesn't need new metadata... This is needed especially
4299 	 * to keep ext2/3 backward compatibility.
4300 	 */
4301 	if (!ext4_has_feature_extents(sb))
4302 		return;
4303 	/*
4304 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4305 	 * This should cover the situations where we can not afford to run
4306 	 * out of space like for example punch hole, or converting
4307 	 * unwritten extents in delalloc path. In most cases such
4308 	 * allocation would require 1, or 2 blocks, higher numbers are
4309 	 * very rare.
4310 	 */
4311 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4312 			 sbi->s_cluster_bits);
4313 
4314 	do_div(resv_clusters, 50);
4315 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4316 
4317 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4318 }
4319 
4320 static const char *ext4_quota_mode(struct super_block *sb)
4321 {
4322 #ifdef CONFIG_QUOTA
4323 	if (!ext4_quota_capable(sb))
4324 		return "none";
4325 
4326 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4327 		return "journalled";
4328 	else
4329 		return "writeback";
4330 #else
4331 	return "disabled";
4332 #endif
4333 }
4334 
4335 static void ext4_setup_csum_trigger(struct super_block *sb,
4336 				    enum ext4_journal_trigger_type type,
4337 				    void (*trigger)(
4338 					struct jbd2_buffer_trigger_type *type,
4339 					struct buffer_head *bh,
4340 					void *mapped_data,
4341 					size_t size))
4342 {
4343 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4344 
4345 	sbi->s_journal_triggers[type].sb = sb;
4346 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4347 }
4348 
4349 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4350 {
4351 	if (!sbi)
4352 		return;
4353 
4354 	kfree(sbi->s_blockgroup_lock);
4355 	fs_put_dax(sbi->s_daxdev, NULL);
4356 	kfree(sbi);
4357 }
4358 
4359 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4360 {
4361 	struct ext4_sb_info *sbi;
4362 
4363 	sbi = kzalloc_obj(*sbi);
4364 	if (!sbi)
4365 		return NULL;
4366 
4367 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4368 					   NULL, NULL);
4369 
4370 	sbi->s_blockgroup_lock =
4371 		kzalloc_obj(struct blockgroup_lock);
4372 
4373 	if (!sbi->s_blockgroup_lock)
4374 		goto err_out;
4375 
4376 	sb->s_fs_info = sbi;
4377 	sbi->s_sb = sb;
4378 	return sbi;
4379 err_out:
4380 	fs_put_dax(sbi->s_daxdev, NULL);
4381 	kfree(sbi);
4382 	return NULL;
4383 }
4384 
4385 static void ext4_set_def_opts(struct super_block *sb,
4386 			      struct ext4_super_block *es)
4387 {
4388 	unsigned long def_mount_opts;
4389 
4390 	/* Set defaults before we parse the mount options */
4391 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4392 	set_opt(sb, INIT_INODE_TABLE);
4393 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4394 		set_opt(sb, DEBUG);
4395 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4396 		set_opt(sb, GRPID);
4397 	if (def_mount_opts & EXT4_DEFM_UID16)
4398 		set_opt(sb, NO_UID32);
4399 	/* xattr user namespace & acls are now defaulted on */
4400 	set_opt(sb, XATTR_USER);
4401 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4402 	set_opt(sb, POSIX_ACL);
4403 #endif
4404 	if (ext4_has_feature_fast_commit(sb))
4405 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4406 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4407 	if (ext4_has_feature_metadata_csum(sb))
4408 		set_opt(sb, JOURNAL_CHECKSUM);
4409 
4410 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4411 		set_opt(sb, JOURNAL_DATA);
4412 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4413 		set_opt(sb, ORDERED_DATA);
4414 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4415 		set_opt(sb, WRITEBACK_DATA);
4416 
4417 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4418 		set_opt(sb, ERRORS_PANIC);
4419 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4420 		set_opt(sb, ERRORS_CONT);
4421 	else
4422 		set_opt(sb, ERRORS_RO);
4423 	/* block_validity enabled by default; disable with noblock_validity */
4424 	set_opt(sb, BLOCK_VALIDITY);
4425 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4426 		set_opt(sb, DISCARD);
4427 
4428 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4429 		set_opt(sb, BARRIER);
4430 
4431 	/*
4432 	 * enable delayed allocation by default
4433 	 * Use -o nodelalloc to turn it off
4434 	 */
4435 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4436 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4437 		set_opt(sb, DELALLOC);
4438 
4439 	set_opt(sb, DIOREAD_NOLOCK);
4440 }
4441 
4442 static int ext4_handle_clustersize(struct super_block *sb)
4443 {
4444 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4445 	struct ext4_super_block *es = sbi->s_es;
4446 	int clustersize;
4447 
4448 	/* Handle clustersize */
4449 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4450 	if (ext4_has_feature_bigalloc(sb)) {
4451 		if (clustersize < sb->s_blocksize) {
4452 			ext4_msg(sb, KERN_ERR,
4453 				 "cluster size (%d) smaller than "
4454 				 "block size (%lu)", clustersize, sb->s_blocksize);
4455 			return -EINVAL;
4456 		}
4457 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4458 			le32_to_cpu(es->s_log_block_size);
4459 	} else {
4460 		if (clustersize != sb->s_blocksize) {
4461 			ext4_msg(sb, KERN_ERR,
4462 				 "fragment/cluster size (%d) != "
4463 				 "block size (%lu)", clustersize, sb->s_blocksize);
4464 			return -EINVAL;
4465 		}
4466 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4467 			ext4_msg(sb, KERN_ERR,
4468 				 "#blocks per group too big: %lu",
4469 				 sbi->s_blocks_per_group);
4470 			return -EINVAL;
4471 		}
4472 		sbi->s_cluster_bits = 0;
4473 	}
4474 	sbi->s_clusters_per_group = le32_to_cpu(es->s_clusters_per_group);
4475 	if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4476 		ext4_msg(sb, KERN_ERR, "#clusters per group too big: %lu",
4477 			 sbi->s_clusters_per_group);
4478 		return -EINVAL;
4479 	}
4480 	if (sbi->s_blocks_per_group !=
4481 	    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4482 		ext4_msg(sb, KERN_ERR,
4483 			 "blocks per group (%lu) and clusters per group (%lu) inconsistent",
4484 			 sbi->s_blocks_per_group, sbi->s_clusters_per_group);
4485 		return -EINVAL;
4486 	}
4487 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4488 
4489 	/* Do we have standard group size of clustersize * 8 blocks ? */
4490 	if (sbi->s_blocks_per_group == clustersize << 3)
4491 		set_opt2(sb, STD_GROUP_SIZE);
4492 
4493 	return 0;
4494 }
4495 
4496 /*
4497  * ext4_atomic_write_init: Initializes filesystem min & max atomic write units.
4498  * With non-bigalloc filesystem awu will be based upon filesystem blocksize
4499  * & bdev awu units.
4500  * With bigalloc it will be based upon bigalloc cluster size & bdev awu units.
4501  * @sb: super block
4502  */
4503 static void ext4_atomic_write_init(struct super_block *sb)
4504 {
4505 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4506 	struct block_device *bdev = sb->s_bdev;
4507 	unsigned int clustersize = EXT4_CLUSTER_SIZE(sb);
4508 
4509 	if (!bdev_can_atomic_write(bdev))
4510 		return;
4511 
4512 	if (!ext4_has_feature_extents(sb))
4513 		return;
4514 
4515 	sbi->s_awu_min = max(sb->s_blocksize,
4516 			      bdev_atomic_write_unit_min_bytes(bdev));
4517 	sbi->s_awu_max = min(clustersize,
4518 			      bdev_atomic_write_unit_max_bytes(bdev));
4519 	if (sbi->s_awu_min && sbi->s_awu_max &&
4520 	    sbi->s_awu_min <= sbi->s_awu_max) {
4521 		ext4_msg(sb, KERN_NOTICE, "Supports (experimental) DIO atomic writes awu_min: %u, awu_max: %u",
4522 			 sbi->s_awu_min, sbi->s_awu_max);
4523 	} else {
4524 		sbi->s_awu_min = 0;
4525 		sbi->s_awu_max = 0;
4526 	}
4527 }
4528 
4529 static void ext4_fast_commit_init(struct super_block *sb)
4530 {
4531 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4532 
4533 	/* Initialize fast commit stuff */
4534 	atomic_set(&sbi->s_fc_subtid, 0);
4535 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4536 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4537 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4538 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4539 	sbi->s_fc_bytes = 0;
4540 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4541 	sbi->s_fc_ineligible_tid = 0;
4542 	mutex_init(&sbi->s_fc_lock);
4543 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4544 	sbi->s_fc_replay_state.fc_regions = NULL;
4545 	sbi->s_fc_replay_state.fc_regions_size = 0;
4546 	sbi->s_fc_replay_state.fc_regions_used = 0;
4547 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4548 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4549 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4550 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4551 }
4552 
4553 static int ext4_inode_info_init(struct super_block *sb,
4554 				struct ext4_super_block *es)
4555 {
4556 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4557 
4558 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4559 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4560 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4561 	} else {
4562 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4563 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4564 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4565 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4566 				 sbi->s_first_ino);
4567 			return -EINVAL;
4568 		}
4569 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4570 		    (!is_power_of_2(sbi->s_inode_size)) ||
4571 		    (sbi->s_inode_size > sb->s_blocksize)) {
4572 			ext4_msg(sb, KERN_ERR,
4573 			       "unsupported inode size: %d",
4574 			       sbi->s_inode_size);
4575 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4576 			return -EINVAL;
4577 		}
4578 		/*
4579 		 * i_atime_extra is the last extra field available for
4580 		 * [acm]times in struct ext4_inode. Checking for that
4581 		 * field should suffice to ensure we have extra space
4582 		 * for all three.
4583 		 */
4584 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4585 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4586 			sb->s_time_gran = 1;
4587 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4588 		} else {
4589 			sb->s_time_gran = NSEC_PER_SEC;
4590 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4591 		}
4592 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4593 	}
4594 
4595 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4596 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4597 			EXT4_GOOD_OLD_INODE_SIZE;
4598 		if (ext4_has_feature_extra_isize(sb)) {
4599 			unsigned v, max = (sbi->s_inode_size -
4600 					   EXT4_GOOD_OLD_INODE_SIZE);
4601 
4602 			v = le16_to_cpu(es->s_want_extra_isize);
4603 			if (v > max) {
4604 				ext4_msg(sb, KERN_ERR,
4605 					 "bad s_want_extra_isize: %d", v);
4606 				return -EINVAL;
4607 			}
4608 			if (sbi->s_want_extra_isize < v)
4609 				sbi->s_want_extra_isize = v;
4610 
4611 			v = le16_to_cpu(es->s_min_extra_isize);
4612 			if (v > max) {
4613 				ext4_msg(sb, KERN_ERR,
4614 					 "bad s_min_extra_isize: %d", v);
4615 				return -EINVAL;
4616 			}
4617 			if (sbi->s_want_extra_isize < v)
4618 				sbi->s_want_extra_isize = v;
4619 		}
4620 	}
4621 
4622 	return 0;
4623 }
4624 
4625 #if IS_ENABLED(CONFIG_UNICODE)
4626 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4627 {
4628 	const struct ext4_sb_encodings *encoding_info;
4629 	struct unicode_map *encoding;
4630 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4631 
4632 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4633 		return 0;
4634 
4635 	encoding_info = ext4_sb_read_encoding(es);
4636 	if (!encoding_info) {
4637 		ext4_msg(sb, KERN_ERR,
4638 			"Encoding requested by superblock is unknown");
4639 		return -EINVAL;
4640 	}
4641 
4642 	encoding = utf8_load(encoding_info->version);
4643 	if (IS_ERR(encoding)) {
4644 		ext4_msg(sb, KERN_ERR,
4645 			"can't mount with superblock charset: %s-%u.%u.%u "
4646 			"not supported by the kernel. flags: 0x%x.",
4647 			encoding_info->name,
4648 			unicode_major(encoding_info->version),
4649 			unicode_minor(encoding_info->version),
4650 			unicode_rev(encoding_info->version),
4651 			encoding_flags);
4652 		return -EINVAL;
4653 	}
4654 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4655 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4656 		unicode_major(encoding_info->version),
4657 		unicode_minor(encoding_info->version),
4658 		unicode_rev(encoding_info->version),
4659 		encoding_flags);
4660 
4661 	sb->s_encoding = encoding;
4662 	sb->s_encoding_flags = encoding_flags;
4663 
4664 	return 0;
4665 }
4666 #else
4667 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4668 {
4669 	return 0;
4670 }
4671 #endif
4672 
4673 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4674 {
4675 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4676 
4677 	/* Warn if metadata_csum and gdt_csum are both set. */
4678 	if (ext4_has_feature_metadata_csum(sb) &&
4679 	    ext4_has_feature_gdt_csum(sb))
4680 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4681 			     "redundant flags; please run fsck.");
4682 
4683 	/* Check for a known checksum algorithm */
4684 	if (!ext4_verify_csum_type(sb, es)) {
4685 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4686 			 "unknown checksum algorithm.");
4687 		return -EINVAL;
4688 	}
4689 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4690 				ext4_orphan_file_block_trigger);
4691 
4692 	/* Check superblock checksum */
4693 	if (!ext4_superblock_csum_verify(sb, es)) {
4694 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4695 			 "invalid superblock checksum.  Run e2fsck?");
4696 		return -EFSBADCRC;
4697 	}
4698 
4699 	/* Precompute checksum seed for all metadata */
4700 	if (ext4_has_feature_csum_seed(sb))
4701 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4702 	else if (ext4_has_feature_metadata_csum(sb) ||
4703 		 ext4_has_feature_ea_inode(sb))
4704 		sbi->s_csum_seed = ext4_chksum(~0, es->s_uuid,
4705 					       sizeof(es->s_uuid));
4706 	return 0;
4707 }
4708 
4709 static int ext4_check_feature_compatibility(struct super_block *sb,
4710 					    struct ext4_super_block *es,
4711 					    int silent)
4712 {
4713 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4714 
4715 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4716 	    (ext4_has_compat_features(sb) ||
4717 	     ext4_has_ro_compat_features(sb) ||
4718 	     ext4_has_incompat_features(sb)))
4719 		ext4_msg(sb, KERN_WARNING,
4720 		       "feature flags set on rev 0 fs, "
4721 		       "running e2fsck is recommended");
4722 
4723 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4724 		set_opt2(sb, HURD_COMPAT);
4725 		if (ext4_has_feature_64bit(sb)) {
4726 			ext4_msg(sb, KERN_ERR,
4727 				 "The Hurd can't support 64-bit file systems");
4728 			return -EINVAL;
4729 		}
4730 
4731 		/*
4732 		 * ea_inode feature uses l_i_version field which is not
4733 		 * available in HURD_COMPAT mode.
4734 		 */
4735 		if (ext4_has_feature_ea_inode(sb)) {
4736 			ext4_msg(sb, KERN_ERR,
4737 				 "ea_inode feature is not supported for Hurd");
4738 			return -EINVAL;
4739 		}
4740 	}
4741 
4742 	if (IS_EXT2_SB(sb)) {
4743 		if (ext2_feature_set_ok(sb))
4744 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4745 				 "using the ext4 subsystem");
4746 		else {
4747 			/*
4748 			 * If we're probing be silent, if this looks like
4749 			 * it's actually an ext[34] filesystem.
4750 			 */
4751 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4752 				return -EINVAL;
4753 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4754 				 "to feature incompatibilities");
4755 			return -EINVAL;
4756 		}
4757 	}
4758 
4759 	if (IS_EXT3_SB(sb)) {
4760 		if (ext3_feature_set_ok(sb))
4761 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4762 				 "using the ext4 subsystem");
4763 		else {
4764 			/*
4765 			 * If we're probing be silent, if this looks like
4766 			 * it's actually an ext4 filesystem.
4767 			 */
4768 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4769 				return -EINVAL;
4770 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4771 				 "to feature incompatibilities");
4772 			return -EINVAL;
4773 		}
4774 	}
4775 
4776 	/*
4777 	 * Check feature flags regardless of the revision level, since we
4778 	 * previously didn't change the revision level when setting the flags,
4779 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4780 	 */
4781 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4782 		return -EINVAL;
4783 
4784 	if (sbi->s_daxdev) {
4785 		if (sb->s_blocksize == PAGE_SIZE)
4786 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4787 		else
4788 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4789 	}
4790 
4791 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4792 		if (ext4_has_feature_inline_data(sb)) {
4793 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4794 					" that may contain inline data");
4795 			return -EINVAL;
4796 		}
4797 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4798 			ext4_msg(sb, KERN_ERR,
4799 				"DAX unsupported by block device.");
4800 			return -EINVAL;
4801 		}
4802 	}
4803 
4804 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4805 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4806 			 es->s_encryption_level);
4807 		return -EINVAL;
4808 	}
4809 
4810 	return 0;
4811 }
4812 
4813 static int ext4_check_geometry(struct super_block *sb,
4814 			       struct ext4_super_block *es)
4815 {
4816 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4817 	__u64 blocks_count;
4818 	int err;
4819 
4820 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4821 		ext4_msg(sb, KERN_ERR,
4822 			 "Number of reserved GDT blocks insanely large: %d",
4823 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4824 		return -EINVAL;
4825 	}
4826 	/*
4827 	 * Test whether we have more sectors than will fit in sector_t,
4828 	 * and whether the max offset is addressable by the page cache.
4829 	 */
4830 	err = generic_check_addressable(sb->s_blocksize_bits,
4831 					ext4_blocks_count(es));
4832 	if (err) {
4833 		ext4_msg(sb, KERN_ERR, "filesystem"
4834 			 " too large to mount safely on this system");
4835 		return err;
4836 	}
4837 
4838 	/* check blocks count against device size */
4839 	blocks_count = sb_bdev_nr_blocks(sb);
4840 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4841 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4842 		       "exceeds size of device (%llu blocks)",
4843 		       ext4_blocks_count(es), blocks_count);
4844 		return -EINVAL;
4845 	}
4846 
4847 	/*
4848 	 * It makes no sense for the first data block to be beyond the end
4849 	 * of the filesystem.
4850 	 */
4851 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4852 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4853 			 "block %u is beyond end of filesystem (%llu)",
4854 			 le32_to_cpu(es->s_first_data_block),
4855 			 ext4_blocks_count(es));
4856 		return -EINVAL;
4857 	}
4858 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4859 	    (sbi->s_cluster_ratio == 1)) {
4860 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4861 			 "block is 0 with a 1k block and cluster size");
4862 		return -EINVAL;
4863 	}
4864 
4865 	blocks_count = (ext4_blocks_count(es) -
4866 			le32_to_cpu(es->s_first_data_block) +
4867 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4868 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4869 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4870 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4871 		       "(block count %llu, first data block %u, "
4872 		       "blocks per group %lu)", blocks_count,
4873 		       ext4_blocks_count(es),
4874 		       le32_to_cpu(es->s_first_data_block),
4875 		       EXT4_BLOCKS_PER_GROUP(sb));
4876 		return -EINVAL;
4877 	}
4878 	sbi->s_groups_count = blocks_count;
4879 	sbi->s_blockfile_groups = min(sbi->s_groups_count,
4880 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4881 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4882 	    le32_to_cpu(es->s_inodes_count)) {
4883 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4884 			 le32_to_cpu(es->s_inodes_count),
4885 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4886 		return -EINVAL;
4887 	}
4888 
4889 	return 0;
4890 }
4891 
4892 static int ext4_group_desc_init(struct super_block *sb,
4893 				struct ext4_super_block *es,
4894 				ext4_fsblk_t logical_sb_block,
4895 				ext4_group_t *first_not_zeroed)
4896 {
4897 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4898 	unsigned int db_count;
4899 	ext4_fsblk_t block;
4900 	int i;
4901 
4902 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4903 		   EXT4_DESC_PER_BLOCK(sb);
4904 	if (ext4_has_feature_meta_bg(sb)) {
4905 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4906 			ext4_msg(sb, KERN_WARNING,
4907 				 "first meta block group too large: %u "
4908 				 "(group descriptor block count %u)",
4909 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4910 			return -EINVAL;
4911 		}
4912 	}
4913 	rcu_assign_pointer(sbi->s_group_desc,
4914 			   kvmalloc_objs(struct buffer_head *, db_count));
4915 	if (sbi->s_group_desc == NULL) {
4916 		ext4_msg(sb, KERN_ERR, "not enough memory");
4917 		return -ENOMEM;
4918 	}
4919 
4920 	bgl_lock_init(sbi->s_blockgroup_lock);
4921 
4922 	/* Pre-read the descriptors into the buffer cache */
4923 	for (i = 0; i < db_count; i++) {
4924 		block = descriptor_loc(sb, logical_sb_block, i);
4925 		ext4_sb_breadahead_unmovable(sb, block);
4926 	}
4927 
4928 	for (i = 0; i < db_count; i++) {
4929 		struct buffer_head *bh;
4930 
4931 		block = descriptor_loc(sb, logical_sb_block, i);
4932 		bh = ext4_sb_bread_unmovable(sb, block);
4933 		if (IS_ERR(bh)) {
4934 			ext4_msg(sb, KERN_ERR,
4935 			       "can't read group descriptor %d", i);
4936 			sbi->s_gdb_count = i;
4937 			return PTR_ERR(bh);
4938 		}
4939 		rcu_read_lock();
4940 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4941 		rcu_read_unlock();
4942 	}
4943 	sbi->s_gdb_count = db_count;
4944 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4945 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4946 		return -EFSCORRUPTED;
4947 	}
4948 
4949 	return 0;
4950 }
4951 
4952 static int ext4_load_and_init_journal(struct super_block *sb,
4953 				      struct ext4_super_block *es,
4954 				      struct ext4_fs_context *ctx)
4955 {
4956 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4957 	int err;
4958 
4959 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4960 	if (err)
4961 		return err;
4962 
4963 	if (ext4_has_feature_64bit(sb) &&
4964 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4965 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4966 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4967 		goto out;
4968 	}
4969 
4970 	if (!set_journal_csum_feature_set(sb)) {
4971 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4972 			 "feature set");
4973 		goto out;
4974 	}
4975 
4976 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4977 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4978 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4979 		ext4_msg(sb, KERN_ERR,
4980 			"Failed to set fast commit journal feature");
4981 		goto out;
4982 	}
4983 
4984 	/* We have now updated the journal if required, so we can
4985 	 * validate the data journaling mode. */
4986 	switch (test_opt(sb, DATA_FLAGS)) {
4987 	case 0:
4988 		/* No mode set, assume a default based on the journal
4989 		 * capabilities: ORDERED_DATA if the journal can
4990 		 * cope, else JOURNAL_DATA
4991 		 */
4992 		if (jbd2_journal_check_available_features
4993 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4994 			set_opt(sb, ORDERED_DATA);
4995 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4996 		} else {
4997 			set_opt(sb, JOURNAL_DATA);
4998 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4999 		}
5000 		break;
5001 
5002 	case EXT4_MOUNT_ORDERED_DATA:
5003 	case EXT4_MOUNT_WRITEBACK_DATA:
5004 		if (!jbd2_journal_check_available_features
5005 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5006 			ext4_msg(sb, KERN_ERR, "Journal does not support "
5007 			       "requested data journaling mode");
5008 			goto out;
5009 		}
5010 		break;
5011 	default:
5012 		break;
5013 	}
5014 
5015 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5016 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5017 		ext4_msg(sb, KERN_ERR, "can't mount with "
5018 			"journal_async_commit in data=ordered mode");
5019 		goto out;
5020 	}
5021 
5022 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5023 
5024 	sbi->s_journal->j_submit_inode_data_buffers =
5025 		ext4_journal_submit_inode_data_buffers;
5026 	sbi->s_journal->j_finish_inode_data_buffers =
5027 		ext4_journal_finish_inode_data_buffers;
5028 
5029 	return 0;
5030 
5031 out:
5032 	ext4_journal_destroy(sbi, sbi->s_journal);
5033 	return -EINVAL;
5034 }
5035 
5036 static int ext4_check_journal_data_mode(struct super_block *sb)
5037 {
5038 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5039 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
5040 			    "data=journal disables delayed allocation, "
5041 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
5042 		/* can't mount with both data=journal and dioread_nolock. */
5043 		clear_opt(sb, DIOREAD_NOLOCK);
5044 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5045 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5046 			ext4_msg(sb, KERN_ERR, "can't mount with "
5047 				 "both data=journal and delalloc");
5048 			return -EINVAL;
5049 		}
5050 		if (test_opt(sb, DAX_ALWAYS)) {
5051 			ext4_msg(sb, KERN_ERR, "can't mount with "
5052 				 "both data=journal and dax");
5053 			return -EINVAL;
5054 		}
5055 		if (ext4_has_feature_encrypt(sb)) {
5056 			ext4_msg(sb, KERN_WARNING,
5057 				 "encrypted files will use data=ordered "
5058 				 "instead of data journaling mode");
5059 		}
5060 		if (test_opt(sb, DELALLOC))
5061 			clear_opt(sb, DELALLOC);
5062 	} else {
5063 		sb->s_iflags |= SB_I_CGROUPWB;
5064 	}
5065 
5066 	return 0;
5067 }
5068 
5069 static const char *ext4_has_journal_option(struct super_block *sb)
5070 {
5071 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5072 
5073 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
5074 		return "journal_async_commit";
5075 	if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM))
5076 		return "journal_checksum";
5077 	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
5078 		return "commit=";
5079 	if (EXT4_MOUNT_DATA_FLAGS &
5080 	    (sbi->s_mount_opt ^ sbi->s_def_mount_opt))
5081 		return "data=";
5082 	if (test_opt(sb, DATA_ERR_ABORT))
5083 		return "data_err=abort";
5084 	return NULL;
5085 }
5086 
5087 /*
5088  * Limit the maximum folio order to 2048 blocks to prevent overestimation
5089  * of reserve handle credits during the folio writeback in environments
5090  * where the PAGE_SIZE exceeds 4KB.
5091  */
5092 #define EXT4_MAX_PAGECACHE_ORDER(sb)		\
5093 		umin(MAX_PAGECACHE_ORDER, (11 + (sb)->s_blocksize_bits - PAGE_SHIFT))
5094 static void ext4_set_max_mapping_order(struct super_block *sb)
5095 {
5096 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5097 
5098 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5099 		sbi->s_max_folio_order = sbi->s_min_folio_order;
5100 	else
5101 		sbi->s_max_folio_order = EXT4_MAX_PAGECACHE_ORDER(sb);
5102 }
5103 
5104 static int ext4_check_large_folio(struct super_block *sb)
5105 {
5106 	const char *err_str = NULL;
5107 
5108 	if (ext4_has_feature_encrypt(sb))
5109 		err_str = "encrypt";
5110 
5111 	if (!err_str) {
5112 		ext4_set_max_mapping_order(sb);
5113 	} else if (sb->s_blocksize > PAGE_SIZE) {
5114 		ext4_msg(sb, KERN_ERR, "bs(%lu) > ps(%lu) unsupported for %s",
5115 			 sb->s_blocksize, PAGE_SIZE, err_str);
5116 		return -EINVAL;
5117 	}
5118 
5119 	return 0;
5120 }
5121 
5122 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5123 			   int silent)
5124 {
5125 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5126 	struct ext4_super_block *es;
5127 	ext4_fsblk_t logical_sb_block;
5128 	unsigned long offset = 0;
5129 	struct buffer_head *bh;
5130 	int ret = -EINVAL;
5131 	int blocksize;
5132 
5133 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5134 	if (!blocksize) {
5135 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5136 		return -EINVAL;
5137 	}
5138 
5139 	/*
5140 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5141 	 * block sizes.  We need to calculate the offset from buffer start.
5142 	 */
5143 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5144 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5145 		offset = do_div(logical_sb_block, blocksize);
5146 	} else {
5147 		logical_sb_block = sbi->s_sb_block;
5148 	}
5149 
5150 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5151 	if (IS_ERR(bh)) {
5152 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5153 		return PTR_ERR(bh);
5154 	}
5155 	/*
5156 	 * Note: s_es must be initialized as soon as possible because
5157 	 *       some ext4 macro-instructions depend on its value
5158 	 */
5159 	es = (struct ext4_super_block *) (bh->b_data + offset);
5160 	sbi->s_es = es;
5161 	sb->s_magic = le16_to_cpu(es->s_magic);
5162 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5163 		if (!silent)
5164 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5165 		goto out;
5166 	}
5167 
5168 	if (le32_to_cpu(es->s_log_block_size) >
5169 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5170 		ext4_msg(sb, KERN_ERR,
5171 			 "Invalid log block size: %u",
5172 			 le32_to_cpu(es->s_log_block_size));
5173 		goto out;
5174 	}
5175 	if (le32_to_cpu(es->s_log_cluster_size) >
5176 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5177 		ext4_msg(sb, KERN_ERR,
5178 			 "Invalid log cluster size: %u",
5179 			 le32_to_cpu(es->s_log_cluster_size));
5180 		goto out;
5181 	}
5182 
5183 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5184 
5185 	/*
5186 	 * If the default block size is not the same as the real block size,
5187 	 * we need to reload it.
5188 	 */
5189 	if (sb->s_blocksize == blocksize)
5190 		goto success;
5191 
5192 	/*
5193 	 * bh must be released before kill_bdev(), otherwise
5194 	 * it won't be freed and its page also. kill_bdev()
5195 	 * is called by sb_set_blocksize().
5196 	 */
5197 	brelse(bh);
5198 	/* Validate the filesystem blocksize */
5199 	if (!sb_set_blocksize(sb, blocksize)) {
5200 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5201 				blocksize);
5202 		bh = NULL;
5203 		goto out;
5204 	}
5205 
5206 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5207 	offset = do_div(logical_sb_block, blocksize);
5208 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5209 	if (IS_ERR(bh)) {
5210 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5211 		ret = PTR_ERR(bh);
5212 		bh = NULL;
5213 		goto out;
5214 	}
5215 	es = (struct ext4_super_block *)(bh->b_data + offset);
5216 	sbi->s_es = es;
5217 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5218 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5219 		goto out;
5220 	}
5221 
5222 success:
5223 	sbi->s_min_folio_order = get_order(blocksize);
5224 	*lsb = logical_sb_block;
5225 	sbi->s_sbh = bh;
5226 	return 0;
5227 out:
5228 	brelse(bh);
5229 	return ret;
5230 }
5231 
5232 static int ext4_hash_info_init(struct super_block *sb)
5233 {
5234 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5235 	struct ext4_super_block *es = sbi->s_es;
5236 	unsigned int i;
5237 
5238 	sbi->s_def_hash_version = es->s_def_hash_version;
5239 
5240 	if (sbi->s_def_hash_version > DX_HASH_LAST) {
5241 		ext4_msg(sb, KERN_ERR,
5242 			 "Invalid default hash set in the superblock");
5243 		return -EINVAL;
5244 	} else if (sbi->s_def_hash_version == DX_HASH_SIPHASH) {
5245 		ext4_msg(sb, KERN_ERR,
5246 			 "SIPHASH is not a valid default hash value");
5247 		return -EINVAL;
5248 	}
5249 
5250 	for (i = 0; i < 4; i++)
5251 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5252 
5253 	if (ext4_has_feature_dir_index(sb)) {
5254 		i = le32_to_cpu(es->s_flags);
5255 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5256 			sbi->s_hash_unsigned = 3;
5257 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5258 #ifdef __CHAR_UNSIGNED__
5259 			if (!sb_rdonly(sb))
5260 				es->s_flags |=
5261 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5262 			sbi->s_hash_unsigned = 3;
5263 #else
5264 			if (!sb_rdonly(sb))
5265 				es->s_flags |=
5266 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5267 #endif
5268 		}
5269 	}
5270 	return 0;
5271 }
5272 
5273 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5274 {
5275 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5276 	struct ext4_super_block *es = sbi->s_es;
5277 	int has_huge_files;
5278 
5279 	has_huge_files = ext4_has_feature_huge_file(sb);
5280 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5281 						      has_huge_files);
5282 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5283 
5284 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5285 	if (ext4_has_feature_64bit(sb)) {
5286 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5287 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5288 		    !is_power_of_2(sbi->s_desc_size)) {
5289 			ext4_msg(sb, KERN_ERR,
5290 			       "unsupported descriptor size %lu",
5291 			       sbi->s_desc_size);
5292 			return -EINVAL;
5293 		}
5294 	} else
5295 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5296 
5297 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5298 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5299 
5300 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5301 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5302 		if (!silent)
5303 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5304 		return -EINVAL;
5305 	}
5306 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5307 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5308 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5309 			 sbi->s_inodes_per_group);
5310 		return -EINVAL;
5311 	}
5312 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5313 					sbi->s_inodes_per_block;
5314 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5315 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5316 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5317 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5318 
5319 	return 0;
5320 }
5321 
5322 /*
5323  * It's hard to get stripe aligned blocks if stripe is not aligned with
5324  * cluster, just disable stripe and alert user to simplify code and avoid
5325  * stripe aligned allocation which will rarely succeed.
5326  */
5327 static bool ext4_is_stripe_incompatible(struct super_block *sb, unsigned long stripe)
5328 {
5329 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5330 	return (stripe > 0 && sbi->s_cluster_ratio > 1 &&
5331 		stripe % sbi->s_cluster_ratio != 0);
5332 }
5333 
5334 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5335 {
5336 	struct ext4_super_block *es = NULL;
5337 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5338 	ext4_fsblk_t logical_sb_block;
5339 	struct inode *root;
5340 	int needs_recovery;
5341 	int err;
5342 	ext4_group_t first_not_zeroed;
5343 	struct ext4_fs_context *ctx = fc->fs_private;
5344 	int silent = fc->sb_flags & SB_SILENT;
5345 
5346 	/* Set defaults for the variables that will be set during parsing */
5347 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5348 		ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
5349 
5350 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5351 	sbi->s_sectors_written_start =
5352 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5353 
5354 	err = ext4_load_super(sb, &logical_sb_block, silent);
5355 	if (err)
5356 		goto out_fail;
5357 
5358 	es = sbi->s_es;
5359 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5360 
5361 	err = ext4_init_metadata_csum(sb, es);
5362 	if (err)
5363 		goto failed_mount;
5364 
5365 	ext4_set_def_opts(sb, es);
5366 
5367 	sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
5368 	sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
5369 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5370 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5371 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5372 	sbi->s_sb_update_kb = EXT4_DEF_SB_UPDATE_INTERVAL_KB;
5373 	sbi->s_sb_update_sec = EXT4_DEF_SB_UPDATE_INTERVAL_SEC;
5374 
5375 	/*
5376 	 * set default s_li_wait_mult for lazyinit, for the case there is
5377 	 * no mount option specified.
5378 	 */
5379 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5380 
5381 	err = ext4_inode_info_init(sb, es);
5382 	if (err)
5383 		goto failed_mount;
5384 
5385 	err = parse_apply_sb_mount_options(sb, ctx);
5386 	if (err < 0)
5387 		goto failed_mount;
5388 
5389 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5390 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5391 
5392 	err = ext4_check_opt_consistency(fc, sb);
5393 	if (err < 0)
5394 		goto failed_mount;
5395 
5396 	ext4_apply_options(fc, sb);
5397 
5398 	err = ext4_check_large_folio(sb);
5399 	if (err < 0)
5400 		goto failed_mount;
5401 
5402 	err = ext4_encoding_init(sb, es);
5403 	if (err)
5404 		goto failed_mount;
5405 
5406 	err = ext4_check_journal_data_mode(sb);
5407 	if (err)
5408 		goto failed_mount;
5409 
5410 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5411 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5412 
5413 	/* HSM events are allowed by default. */
5414 	sb->s_iflags |= SB_I_ALLOW_HSM;
5415 
5416 	err = ext4_check_feature_compatibility(sb, es, silent);
5417 	if (err)
5418 		goto failed_mount;
5419 
5420 	err = ext4_block_group_meta_init(sb, silent);
5421 	if (err)
5422 		goto failed_mount;
5423 
5424 	err = ext4_hash_info_init(sb);
5425 	if (err)
5426 		goto failed_mount;
5427 
5428 	err = ext4_handle_clustersize(sb);
5429 	if (err)
5430 		goto failed_mount;
5431 
5432 	err = ext4_check_geometry(sb, es);
5433 	if (err)
5434 		goto failed_mount;
5435 
5436 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5437 	spin_lock_init(&sbi->s_error_lock);
5438 	mutex_init(&sbi->s_error_notify_mutex);
5439 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5440 
5441 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5442 	if (err)
5443 		goto failed_mount3;
5444 
5445 	err = ext4_es_register_shrinker(sbi);
5446 	if (err)
5447 		goto failed_mount3;
5448 
5449 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5450 	if (ext4_is_stripe_incompatible(sb, sbi->s_stripe)) {
5451 		ext4_msg(sb, KERN_WARNING,
5452 			 "stripe (%lu) is not aligned with cluster size (%u), "
5453 			 "stripe is disabled",
5454 			 sbi->s_stripe, sbi->s_cluster_ratio);
5455 		sbi->s_stripe = 0;
5456 	}
5457 	sbi->s_extent_max_zeroout_kb = 32;
5458 
5459 	/*
5460 	 * set up enough so that it can read an inode
5461 	 */
5462 	sb->s_op = &ext4_sops;
5463 	sb->s_export_op = &ext4_export_ops;
5464 	sb->s_xattr = ext4_xattr_handlers;
5465 #ifdef CONFIG_FS_ENCRYPTION
5466 	sb->s_cop = &ext4_cryptops;
5467 #endif
5468 #ifdef CONFIG_FS_VERITY
5469 	sb->s_vop = &ext4_verityops;
5470 #endif
5471 #ifdef CONFIG_QUOTA
5472 	sb->dq_op = &ext4_quota_operations;
5473 	if (ext4_has_feature_quota(sb))
5474 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5475 	else
5476 		sb->s_qcop = &ext4_qctl_operations;
5477 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5478 #endif
5479 	super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));
5480 	super_set_sysfs_name_bdev(sb);
5481 
5482 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5483 	mutex_init(&sbi->s_orphan_lock);
5484 
5485 	spin_lock_init(&sbi->s_bdev_wb_lock);
5486 
5487 	ext4_atomic_write_init(sb);
5488 	ext4_fast_commit_init(sb);
5489 
5490 	sb->s_root = NULL;
5491 
5492 	needs_recovery = (es->s_last_orphan != 0 ||
5493 			  ext4_has_feature_orphan_present(sb) ||
5494 			  ext4_has_feature_journal_needs_recovery(sb));
5495 
5496 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5497 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5498 		if (err)
5499 			goto failed_mount3a;
5500 	}
5501 
5502 	err = -EINVAL;
5503 	/*
5504 	 * The first inode we look at is the journal inode.  Don't try
5505 	 * root first: it may be modified in the journal!
5506 	 */
5507 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5508 		err = ext4_load_and_init_journal(sb, es, ctx);
5509 		if (err)
5510 			goto failed_mount3a;
5511 		if (bdev_read_only(sb->s_bdev))
5512 		    needs_recovery = 0;
5513 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5514 		   ext4_has_feature_journal_needs_recovery(sb)) {
5515 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5516 		       "suppressed and not mounted read-only");
5517 		goto failed_mount3a;
5518 	} else {
5519 		const char *journal_option;
5520 
5521 		/* Nojournal mode, all journal mount options are illegal */
5522 		journal_option = ext4_has_journal_option(sb);
5523 		if (journal_option != NULL) {
5524 			ext4_msg(sb, KERN_ERR,
5525 				 "can't mount with %s, fs mounted w/o journal",
5526 				 journal_option);
5527 			goto failed_mount3a;
5528 		}
5529 
5530 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5531 		clear_opt(sb, JOURNAL_CHECKSUM);
5532 		clear_opt(sb, DATA_FLAGS);
5533 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5534 		sbi->s_journal = NULL;
5535 		needs_recovery = 0;
5536 	}
5537 
5538 	if (!test_opt(sb, NO_MBCACHE)) {
5539 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5540 		if (!sbi->s_ea_block_cache) {
5541 			ext4_msg(sb, KERN_ERR,
5542 				 "Failed to create ea_block_cache");
5543 			err = -EINVAL;
5544 			goto failed_mount_wq;
5545 		}
5546 
5547 		if (ext4_has_feature_ea_inode(sb)) {
5548 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5549 			if (!sbi->s_ea_inode_cache) {
5550 				ext4_msg(sb, KERN_ERR,
5551 					 "Failed to create ea_inode_cache");
5552 				err = -EINVAL;
5553 				goto failed_mount_wq;
5554 			}
5555 		}
5556 	}
5557 
5558 	/*
5559 	 * Get the # of file system overhead blocks from the
5560 	 * superblock if present.
5561 	 */
5562 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5563 	/* ignore the precalculated value if it is ridiculous */
5564 	if (sbi->s_overhead > ext4_blocks_count(es))
5565 		sbi->s_overhead = 0;
5566 	/*
5567 	 * If the bigalloc feature is not enabled recalculating the
5568 	 * overhead doesn't take long, so we might as well just redo
5569 	 * it to make sure we are using the correct value.
5570 	 */
5571 	if (!ext4_has_feature_bigalloc(sb))
5572 		sbi->s_overhead = 0;
5573 	if (sbi->s_overhead == 0) {
5574 		err = ext4_calculate_overhead(sb);
5575 		if (err)
5576 			goto failed_mount_wq;
5577 	}
5578 
5579 	/*
5580 	 * The maximum number of concurrent works can be high and
5581 	 * concurrency isn't really necessary.  Limit it to 1.
5582 	 */
5583 	EXT4_SB(sb)->rsv_conversion_wq =
5584 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5585 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5586 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5587 		err = -ENOMEM;
5588 		goto failed_mount4;
5589 	}
5590 
5591 	/*
5592 	 * The jbd2_journal_load will have done any necessary log recovery,
5593 	 * so we can safely mount the rest of the filesystem now.
5594 	 */
5595 
5596 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5597 	if (IS_ERR(root)) {
5598 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5599 		err = PTR_ERR(root);
5600 		root = NULL;
5601 		goto failed_mount4;
5602 	}
5603 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5604 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5605 		iput(root);
5606 		err = -EFSCORRUPTED;
5607 		goto failed_mount4;
5608 	}
5609 
5610 	generic_set_sb_d_ops(sb);
5611 	sb->s_root = d_make_root(root);
5612 	if (!sb->s_root) {
5613 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5614 		err = -ENOMEM;
5615 		goto failed_mount4;
5616 	}
5617 
5618 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5619 	if (err == -EROFS) {
5620 		sb->s_flags |= SB_RDONLY;
5621 	} else if (err)
5622 		goto failed_mount4a;
5623 
5624 	ext4_set_resv_clusters(sb);
5625 
5626 	if (test_opt(sb, BLOCK_VALIDITY)) {
5627 		err = ext4_setup_system_zone(sb);
5628 		if (err) {
5629 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5630 				 "zone (%d)", err);
5631 			goto failed_mount4a;
5632 		}
5633 	}
5634 	ext4_fc_replay_cleanup(sb);
5635 
5636 	ext4_ext_init(sb);
5637 
5638 	/*
5639 	 * Enable optimize_scan if number of groups is > threshold. This can be
5640 	 * turned off by passing "mb_optimize_scan=0". This can also be
5641 	 * turned on forcefully by passing "mb_optimize_scan=1".
5642 	 */
5643 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5644 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5645 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5646 		else
5647 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5648 	}
5649 
5650 	err = ext4_percpu_param_init(sbi);
5651 	if (err)
5652 		goto failed_mount5;
5653 
5654 	err = ext4_mb_init(sb);
5655 	if (err) {
5656 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5657 			 err);
5658 		goto failed_mount5;
5659 	}
5660 
5661 	/*
5662 	 * We can only set up the journal commit callback once
5663 	 * mballoc is initialized
5664 	 */
5665 	if (sbi->s_journal)
5666 		sbi->s_journal->j_commit_callback =
5667 			ext4_journal_commit_callback;
5668 
5669 	if (ext4_has_feature_flex_bg(sb))
5670 		if (!ext4_fill_flex_info(sb)) {
5671 			ext4_msg(sb, KERN_ERR,
5672 			       "unable to initialize "
5673 			       "flex_bg meta info!");
5674 			err = -ENOMEM;
5675 			goto failed_mount6;
5676 		}
5677 
5678 	err = ext4_register_li_request(sb, first_not_zeroed);
5679 	if (err)
5680 		goto failed_mount6;
5681 
5682 	err = ext4_init_orphan_info(sb);
5683 	if (err)
5684 		goto failed_mount7;
5685 #ifdef CONFIG_QUOTA
5686 	/* Enable quota usage during mount. */
5687 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5688 		err = ext4_enable_quotas(sb);
5689 		if (err)
5690 			goto failed_mount8;
5691 	}
5692 #endif  /* CONFIG_QUOTA */
5693 
5694 	/*
5695 	 * Save the original bdev mapping's wb_err value which could be
5696 	 * used to detect the metadata async write error.
5697 	 */
5698 	errseq_check_and_advance(&sb->s_bdev->bd_mapping->wb_err,
5699 				 &sbi->s_bdev_wb_err);
5700 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5701 	ext4_orphan_cleanup(sb, es);
5702 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5703 	/*
5704 	 * Update the checksum after updating free space/inode counters and
5705 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5706 	 * checksum in the buffer cache until it is written out and
5707 	 * e2fsprogs programs trying to open a file system immediately
5708 	 * after it is mounted can fail.
5709 	 */
5710 	ext4_superblock_csum_set(sb);
5711 	if (needs_recovery) {
5712 		ext4_msg(sb, KERN_INFO, "recovery complete");
5713 		err = ext4_mark_recovery_complete(sb, es);
5714 		if (err)
5715 			goto failed_mount9;
5716 	}
5717 
5718 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev)) {
5719 		ext4_msg(sb, KERN_WARNING,
5720 			 "mounting with \"discard\" option, but the device does not support discard");
5721 		clear_opt(sb, DISCARD);
5722 	}
5723 
5724 	if (es->s_error_count) {
5725 		sbi->s_err_report_sec = 5*60;	/* first time  5 minutes */
5726 		mod_timer(&sbi->s_err_report,
5727 				  jiffies + secs_to_jiffies(sbi->s_err_report_sec));
5728 	}
5729 	sbi->s_err_report_sec = 24*60*60; /* Once a day */
5730 
5731 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5732 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5733 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5734 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5735 	atomic_set(&sbi->s_warning_count, 0);
5736 	atomic_set(&sbi->s_msg_count, 0);
5737 
5738 	/* Register sysfs after all initializations are complete. */
5739 	err = ext4_register_sysfs(sb);
5740 	if (err)
5741 		goto failed_mount9;
5742 
5743 	return 0;
5744 
5745 failed_mount9:
5746 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5747 failed_mount8: __maybe_unused
5748 	ext4_release_orphan_info(sb);
5749 failed_mount7:
5750 	ext4_unregister_li_request(sb);
5751 failed_mount6:
5752 	ext4_mb_release(sb);
5753 	ext4_flex_groups_free(sbi);
5754 failed_mount5:
5755 	ext4_percpu_param_destroy(sbi);
5756 	ext4_ext_release(sb);
5757 	ext4_release_system_zone(sb);
5758 failed_mount4a:
5759 	dput(sb->s_root);
5760 	sb->s_root = NULL;
5761 failed_mount4:
5762 	ext4_msg(sb, KERN_ERR, "mount failed");
5763 	if (EXT4_SB(sb)->rsv_conversion_wq)
5764 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5765 failed_mount_wq:
5766 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5767 	sbi->s_ea_inode_cache = NULL;
5768 
5769 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5770 	sbi->s_ea_block_cache = NULL;
5771 
5772 	if (sbi->s_journal) {
5773 		ext4_journal_destroy(sbi, sbi->s_journal);
5774 	}
5775 failed_mount3a:
5776 	ext4_es_unregister_shrinker(sbi);
5777 failed_mount3:
5778 	/* flush s_sb_upd_work before sbi destroy */
5779 	flush_work(&sbi->s_sb_upd_work);
5780 	ext4_stop_mmpd(sbi);
5781 	timer_delete_sync(&sbi->s_err_report);
5782 	ext4_group_desc_free(sbi);
5783 failed_mount:
5784 #if IS_ENABLED(CONFIG_UNICODE)
5785 	utf8_unload(sb->s_encoding);
5786 #endif
5787 
5788 #ifdef CONFIG_QUOTA
5789 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5790 		kfree(get_qf_name(sb, sbi, i));
5791 #endif
5792 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5793 	brelse(sbi->s_sbh);
5794 	if (sbi->s_journal_bdev_file) {
5795 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
5796 		bdev_fput(sbi->s_journal_bdev_file);
5797 	}
5798 out_fail:
5799 	invalidate_bdev(sb->s_bdev);
5800 	sb->s_fs_info = NULL;
5801 	return err;
5802 }
5803 
5804 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5805 {
5806 	struct ext4_fs_context *ctx = fc->fs_private;
5807 	struct ext4_sb_info *sbi;
5808 	const char *descr;
5809 	int ret;
5810 
5811 	sbi = ext4_alloc_sbi(sb);
5812 	if (!sbi)
5813 		return -ENOMEM;
5814 
5815 	fc->s_fs_info = sbi;
5816 
5817 	/* Cleanup superblock name */
5818 	strreplace(sb->s_id, '/', '!');
5819 
5820 	sbi->s_sb_block = 1;	/* Default super block location */
5821 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5822 		sbi->s_sb_block = ctx->s_sb_block;
5823 
5824 	ret = __ext4_fill_super(fc, sb);
5825 	if (ret < 0)
5826 		goto free_sbi;
5827 
5828 	if (sbi->s_journal) {
5829 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5830 			descr = " journalled data mode";
5831 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5832 			descr = " ordered data mode";
5833 		else
5834 			descr = " writeback data mode";
5835 	} else
5836 		descr = "out journal";
5837 
5838 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5839 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5840 			 "Quota mode: %s.", &sb->s_uuid,
5841 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5842 			 ext4_quota_mode(sb));
5843 
5844 	/* Update the s_overhead_clusters if necessary */
5845 	ext4_update_overhead(sb, false);
5846 	return 0;
5847 
5848 free_sbi:
5849 	ext4_free_sbi(sbi);
5850 	fc->s_fs_info = NULL;
5851 	return ret;
5852 }
5853 
5854 static int ext4_get_tree(struct fs_context *fc)
5855 {
5856 	return get_tree_bdev(fc, ext4_fill_super);
5857 }
5858 
5859 /*
5860  * Setup any per-fs journal parameters now.  We'll do this both on
5861  * initial mount, once the journal has been initialised but before we've
5862  * done any recovery; and again on any subsequent remount.
5863  */
5864 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5865 {
5866 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5867 
5868 	journal->j_commit_interval = sbi->s_commit_interval;
5869 	journal->j_min_batch_time = sbi->s_min_batch_time;
5870 	journal->j_max_batch_time = sbi->s_max_batch_time;
5871 	ext4_fc_init(sb, journal);
5872 
5873 	write_lock(&journal->j_state_lock);
5874 	if (test_opt(sb, BARRIER))
5875 		journal->j_flags |= JBD2_BARRIER;
5876 	else
5877 		journal->j_flags &= ~JBD2_BARRIER;
5878 	/*
5879 	 * Always enable journal cycle record option, letting the journal
5880 	 * records log transactions continuously between each mount.
5881 	 */
5882 	journal->j_flags |= JBD2_CYCLE_RECORD;
5883 	write_unlock(&journal->j_state_lock);
5884 }
5885 
5886 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5887 					     unsigned int journal_inum)
5888 {
5889 	struct inode *journal_inode;
5890 
5891 	/*
5892 	 * Test for the existence of a valid inode on disk.  Bad things
5893 	 * happen if we iget() an unused inode, as the subsequent iput()
5894 	 * will try to delete it.
5895 	 */
5896 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5897 	if (IS_ERR(journal_inode)) {
5898 		ext4_msg(sb, KERN_ERR, "no journal found");
5899 		return ERR_CAST(journal_inode);
5900 	}
5901 	if (!journal_inode->i_nlink) {
5902 		make_bad_inode(journal_inode);
5903 		iput(journal_inode);
5904 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5905 		return ERR_PTR(-EFSCORRUPTED);
5906 	}
5907 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5908 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5909 		iput(journal_inode);
5910 		return ERR_PTR(-EFSCORRUPTED);
5911 	}
5912 
5913 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5914 		  journal_inode, journal_inode->i_size);
5915 	return journal_inode;
5916 }
5917 
5918 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5919 {
5920 	struct ext4_map_blocks map;
5921 	int ret;
5922 
5923 	if (journal->j_inode == NULL)
5924 		return 0;
5925 
5926 	map.m_lblk = *block;
5927 	map.m_len = 1;
5928 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5929 	if (ret <= 0) {
5930 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5931 			 "journal bmap failed: block %llu ret %d\n",
5932 			 *block, ret);
5933 		jbd2_journal_abort(journal, ret ? ret : -EFSCORRUPTED);
5934 		return ret;
5935 	}
5936 	*block = map.m_pblk;
5937 	return 0;
5938 }
5939 
5940 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5941 					  unsigned int journal_inum)
5942 {
5943 	struct inode *journal_inode;
5944 	journal_t *journal;
5945 
5946 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5947 	if (IS_ERR(journal_inode))
5948 		return ERR_CAST(journal_inode);
5949 
5950 	journal = jbd2_journal_init_inode(journal_inode);
5951 	if (IS_ERR(journal)) {
5952 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5953 		iput(journal_inode);
5954 		return ERR_CAST(journal);
5955 	}
5956 	journal->j_private = sb;
5957 	journal->j_bmap = ext4_journal_bmap;
5958 	ext4_init_journal_params(sb, journal);
5959 	return journal;
5960 }
5961 
5962 static struct file *ext4_get_journal_blkdev(struct super_block *sb,
5963 					dev_t j_dev, ext4_fsblk_t *j_start,
5964 					ext4_fsblk_t *j_len)
5965 {
5966 	struct buffer_head *bh;
5967 	struct block_device *bdev;
5968 	struct file *bdev_file;
5969 	int hblock, blocksize;
5970 	ext4_fsblk_t sb_block;
5971 	unsigned long offset;
5972 	struct ext4_super_block *es;
5973 	int errno;
5974 
5975 	bdev_file = bdev_file_open_by_dev(j_dev,
5976 		BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
5977 		sb, &fs_holder_ops);
5978 	if (IS_ERR(bdev_file)) {
5979 		ext4_msg(sb, KERN_ERR,
5980 			 "failed to open journal device unknown-block(%u,%u) %ld",
5981 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev_file));
5982 		return bdev_file;
5983 	}
5984 
5985 	bdev = file_bdev(bdev_file);
5986 	blocksize = sb->s_blocksize;
5987 	hblock = bdev_logical_block_size(bdev);
5988 	if (blocksize < hblock) {
5989 		ext4_msg(sb, KERN_ERR,
5990 			"blocksize too small for journal device");
5991 		errno = -EINVAL;
5992 		goto out_bdev;
5993 	}
5994 
5995 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5996 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5997 	set_blocksize(bdev_file, blocksize);
5998 	bh = __bread(bdev, sb_block, blocksize);
5999 	if (!bh) {
6000 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
6001 		       "external journal");
6002 		errno = -EINVAL;
6003 		goto out_bdev;
6004 	}
6005 
6006 	es = (struct ext4_super_block *) (bh->b_data + offset);
6007 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
6008 	    !(le32_to_cpu(es->s_feature_incompat) &
6009 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
6010 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
6011 		errno = -EFSCORRUPTED;
6012 		goto out_bh;
6013 	}
6014 
6015 	if ((le32_to_cpu(es->s_feature_ro_compat) &
6016 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
6017 	    es->s_checksum != ext4_superblock_csum(es)) {
6018 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
6019 		errno = -EFSCORRUPTED;
6020 		goto out_bh;
6021 	}
6022 
6023 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
6024 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
6025 		errno = -EFSCORRUPTED;
6026 		goto out_bh;
6027 	}
6028 
6029 	*j_start = sb_block + 1;
6030 	*j_len = ext4_blocks_count(es);
6031 	brelse(bh);
6032 	return bdev_file;
6033 
6034 out_bh:
6035 	brelse(bh);
6036 out_bdev:
6037 	bdev_fput(bdev_file);
6038 	return ERR_PTR(errno);
6039 }
6040 
6041 static journal_t *ext4_open_dev_journal(struct super_block *sb,
6042 					dev_t j_dev)
6043 {
6044 	journal_t *journal;
6045 	ext4_fsblk_t j_start;
6046 	ext4_fsblk_t j_len;
6047 	struct file *bdev_file;
6048 	int errno = 0;
6049 
6050 	bdev_file = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
6051 	if (IS_ERR(bdev_file))
6052 		return ERR_CAST(bdev_file);
6053 
6054 	journal = jbd2_journal_init_dev(file_bdev(bdev_file), sb->s_bdev, j_start,
6055 					j_len, sb->s_blocksize);
6056 	if (IS_ERR(journal)) {
6057 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
6058 		errno = PTR_ERR(journal);
6059 		goto out_bdev;
6060 	}
6061 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
6062 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
6063 					"user (unsupported) - %d",
6064 			be32_to_cpu(journal->j_superblock->s_nr_users));
6065 		errno = -EINVAL;
6066 		goto out_journal;
6067 	}
6068 	journal->j_private = sb;
6069 	EXT4_SB(sb)->s_journal_bdev_file = bdev_file;
6070 	ext4_init_journal_params(sb, journal);
6071 	return journal;
6072 
6073 out_journal:
6074 	ext4_journal_destroy(EXT4_SB(sb), journal);
6075 out_bdev:
6076 	bdev_fput(bdev_file);
6077 	return ERR_PTR(errno);
6078 }
6079 
6080 static int ext4_load_journal(struct super_block *sb,
6081 			     struct ext4_super_block *es,
6082 			     unsigned long journal_devnum)
6083 {
6084 	journal_t *journal;
6085 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
6086 	dev_t journal_dev;
6087 	int err = 0;
6088 	int really_read_only;
6089 	int journal_dev_ro;
6090 
6091 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
6092 		return -EFSCORRUPTED;
6093 
6094 	if (journal_devnum &&
6095 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6096 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
6097 			"numbers have changed");
6098 		journal_dev = new_decode_dev(journal_devnum);
6099 	} else
6100 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
6101 
6102 	if (journal_inum && journal_dev) {
6103 		ext4_msg(sb, KERN_ERR,
6104 			 "filesystem has both journal inode and journal device!");
6105 		return -EINVAL;
6106 	}
6107 
6108 	if (journal_inum) {
6109 		journal = ext4_open_inode_journal(sb, journal_inum);
6110 		if (IS_ERR(journal))
6111 			return PTR_ERR(journal);
6112 	} else {
6113 		journal = ext4_open_dev_journal(sb, journal_dev);
6114 		if (IS_ERR(journal))
6115 			return PTR_ERR(journal);
6116 	}
6117 
6118 	journal_dev_ro = bdev_read_only(journal->j_dev);
6119 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
6120 
6121 	if (journal_dev_ro && !sb_rdonly(sb)) {
6122 		ext4_msg(sb, KERN_ERR,
6123 			 "journal device read-only, try mounting with '-o ro'");
6124 		err = -EROFS;
6125 		goto err_out;
6126 	}
6127 
6128 	/*
6129 	 * Are we loading a blank journal or performing recovery after a
6130 	 * crash?  For recovery, we need to check in advance whether we
6131 	 * can get read-write access to the device.
6132 	 */
6133 	if (ext4_has_feature_journal_needs_recovery(sb)) {
6134 		if (sb_rdonly(sb)) {
6135 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
6136 					"required on readonly filesystem");
6137 			if (really_read_only) {
6138 				ext4_msg(sb, KERN_ERR, "write access "
6139 					"unavailable, cannot proceed "
6140 					"(try mounting with noload)");
6141 				err = -EROFS;
6142 				goto err_out;
6143 			}
6144 			ext4_msg(sb, KERN_INFO, "write access will "
6145 			       "be enabled during recovery");
6146 		}
6147 	}
6148 
6149 	if (!(journal->j_flags & JBD2_BARRIER))
6150 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6151 
6152 	if (!ext4_has_feature_journal_needs_recovery(sb))
6153 		err = jbd2_journal_wipe(journal, !really_read_only);
6154 	if (!err) {
6155 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6156 		__le16 orig_state;
6157 		bool changed = false;
6158 
6159 		if (save)
6160 			memcpy(save, ((char *) es) +
6161 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6162 		err = jbd2_journal_load(journal);
6163 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6164 				   save, EXT4_S_ERR_LEN)) {
6165 			memcpy(((char *) es) + EXT4_S_ERR_START,
6166 			       save, EXT4_S_ERR_LEN);
6167 			changed = true;
6168 		}
6169 		kfree(save);
6170 		orig_state = es->s_state;
6171 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6172 					   EXT4_ERROR_FS);
6173 		if (orig_state != es->s_state)
6174 			changed = true;
6175 		/* Write out restored error information to the superblock */
6176 		if (changed && !really_read_only) {
6177 			int err2;
6178 			err2 = ext4_commit_super(sb);
6179 			err = err ? : err2;
6180 		}
6181 	}
6182 
6183 	if (err) {
6184 		ext4_msg(sb, KERN_ERR, "error loading journal");
6185 		goto err_out;
6186 	}
6187 
6188 	EXT4_SB(sb)->s_journal = journal;
6189 	err = ext4_clear_journal_err(sb, es);
6190 	if (err) {
6191 		ext4_journal_destroy(EXT4_SB(sb), journal);
6192 		return err;
6193 	}
6194 
6195 	if (!really_read_only && journal_devnum &&
6196 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6197 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6198 		ext4_commit_super(sb);
6199 	}
6200 	if (!really_read_only && journal_inum &&
6201 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6202 		es->s_journal_inum = cpu_to_le32(journal_inum);
6203 		ext4_commit_super(sb);
6204 	}
6205 
6206 	return 0;
6207 
6208 err_out:
6209 	ext4_journal_destroy(EXT4_SB(sb), journal);
6210 	return err;
6211 }
6212 
6213 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6214 static void ext4_update_super(struct super_block *sb)
6215 {
6216 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6217 	struct ext4_super_block *es = sbi->s_es;
6218 	struct buffer_head *sbh = sbi->s_sbh;
6219 
6220 	lock_buffer(sbh);
6221 	/*
6222 	 * If the file system is mounted read-only, don't update the
6223 	 * superblock write time.  This avoids updating the superblock
6224 	 * write time when we are mounting the root file system
6225 	 * read/only but we need to replay the journal; at that point,
6226 	 * for people who are east of GMT and who make their clock
6227 	 * tick in localtime for Windows bug-for-bug compatibility,
6228 	 * the clock is set in the future, and this will cause e2fsck
6229 	 * to complain and force a full file system check.
6230 	 */
6231 	if (!sb_rdonly(sb))
6232 		ext4_update_tstamp(es, s_wtime);
6233 	es->s_kbytes_written =
6234 		cpu_to_le64(sbi->s_kbytes_written +
6235 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6236 		      sbi->s_sectors_written_start) >> 1));
6237 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6238 		ext4_free_blocks_count_set(es,
6239 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6240 				&sbi->s_freeclusters_counter)));
6241 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6242 		es->s_free_inodes_count =
6243 			cpu_to_le32(percpu_counter_sum_positive(
6244 				&sbi->s_freeinodes_counter));
6245 	/* Copy error information to the on-disk superblock */
6246 	spin_lock(&sbi->s_error_lock);
6247 	if (sbi->s_add_error_count > 0) {
6248 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6249 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6250 			__ext4_update_tstamp(&es->s_first_error_time,
6251 					     &es->s_first_error_time_hi,
6252 					     sbi->s_first_error_time);
6253 			strtomem_pad(es->s_first_error_func,
6254 				     sbi->s_first_error_func, 0);
6255 			es->s_first_error_line =
6256 				cpu_to_le32(sbi->s_first_error_line);
6257 			es->s_first_error_ino =
6258 				cpu_to_le32(sbi->s_first_error_ino);
6259 			es->s_first_error_block =
6260 				cpu_to_le64(sbi->s_first_error_block);
6261 			es->s_first_error_errcode =
6262 				ext4_errno_to_code(sbi->s_first_error_code);
6263 		}
6264 		__ext4_update_tstamp(&es->s_last_error_time,
6265 				     &es->s_last_error_time_hi,
6266 				     sbi->s_last_error_time);
6267 		strtomem_pad(es->s_last_error_func, sbi->s_last_error_func, 0);
6268 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6269 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6270 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6271 		es->s_last_error_errcode =
6272 				ext4_errno_to_code(sbi->s_last_error_code);
6273 		/*
6274 		 * Start the daily error reporting function if it hasn't been
6275 		 * started already and sbi->s_err_report_sec is not zero
6276 		 */
6277 		if (!es->s_error_count && !sbi->s_err_report_sec)
6278 			mod_timer(&sbi->s_err_report,
6279 					  jiffies + secs_to_jiffies(sbi->s_err_report_sec));
6280 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6281 		sbi->s_add_error_count = 0;
6282 	}
6283 	spin_unlock(&sbi->s_error_lock);
6284 
6285 	ext4_superblock_csum_set(sb);
6286 	unlock_buffer(sbh);
6287 }
6288 
6289 static int ext4_commit_super(struct super_block *sb)
6290 {
6291 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6292 
6293 	if (!sbh)
6294 		return -EINVAL;
6295 
6296 	ext4_update_super(sb);
6297 
6298 	lock_buffer(sbh);
6299 	/* Buffer got discarded which means block device got invalidated */
6300 	if (!buffer_mapped(sbh)) {
6301 		unlock_buffer(sbh);
6302 		return -EIO;
6303 	}
6304 
6305 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6306 		/*
6307 		 * Oh, dear.  A previous attempt to write the
6308 		 * superblock failed.  This could happen because the
6309 		 * USB device was yanked out.  Or it could happen to
6310 		 * be a transient write error and maybe the block will
6311 		 * be remapped.  Nothing we can do but to retry the
6312 		 * write and hope for the best.
6313 		 */
6314 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6315 		       "superblock detected");
6316 		clear_buffer_write_io_error(sbh);
6317 		set_buffer_uptodate(sbh);
6318 	}
6319 	get_bh(sbh);
6320 	/* Clear potential dirty bit if it was journalled update */
6321 	clear_buffer_dirty(sbh);
6322 	sbh->b_end_io = end_buffer_write_sync;
6323 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6324 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6325 	wait_on_buffer(sbh);
6326 	if (buffer_write_io_error(sbh)) {
6327 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6328 		       "superblock");
6329 		clear_buffer_write_io_error(sbh);
6330 		set_buffer_uptodate(sbh);
6331 		return -EIO;
6332 	}
6333 	return 0;
6334 }
6335 
6336 /*
6337  * Have we just finished recovery?  If so, and if we are mounting (or
6338  * remounting) the filesystem readonly, then we will end up with a
6339  * consistent fs on disk.  Record that fact.
6340  */
6341 static int ext4_mark_recovery_complete(struct super_block *sb,
6342 				       struct ext4_super_block *es)
6343 {
6344 	int err;
6345 	journal_t *journal = EXT4_SB(sb)->s_journal;
6346 
6347 	if (!ext4_has_feature_journal(sb)) {
6348 		if (journal != NULL) {
6349 			ext4_error(sb, "Journal got removed while the fs was "
6350 				   "mounted!");
6351 			return -EFSCORRUPTED;
6352 		}
6353 		return 0;
6354 	}
6355 	jbd2_journal_lock_updates(journal);
6356 	err = jbd2_journal_flush(journal, 0);
6357 	if (err < 0)
6358 		goto out;
6359 
6360 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6361 	    ext4_has_feature_orphan_present(sb))) {
6362 		if (!ext4_orphan_file_empty(sb)) {
6363 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6364 			err = -EFSCORRUPTED;
6365 			goto out;
6366 		}
6367 		ext4_clear_feature_journal_needs_recovery(sb);
6368 		ext4_clear_feature_orphan_present(sb);
6369 		ext4_commit_super(sb);
6370 	}
6371 out:
6372 	jbd2_journal_unlock_updates(journal);
6373 	return err;
6374 }
6375 
6376 /*
6377  * If we are mounting (or read-write remounting) a filesystem whose journal
6378  * has recorded an error from a previous lifetime, move that error to the
6379  * main filesystem now.
6380  */
6381 static int ext4_clear_journal_err(struct super_block *sb,
6382 				   struct ext4_super_block *es)
6383 {
6384 	journal_t *journal;
6385 	int j_errno;
6386 	const char *errstr;
6387 
6388 	if (!ext4_has_feature_journal(sb)) {
6389 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6390 		return -EFSCORRUPTED;
6391 	}
6392 
6393 	journal = EXT4_SB(sb)->s_journal;
6394 
6395 	/*
6396 	 * Now check for any error status which may have been recorded in the
6397 	 * journal by a prior ext4_error() or ext4_abort()
6398 	 */
6399 
6400 	j_errno = jbd2_journal_errno(journal);
6401 	if (j_errno) {
6402 		char nbuf[16];
6403 
6404 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6405 		ext4_warning(sb, "Filesystem error recorded "
6406 			     "from previous mount: %s", errstr);
6407 
6408 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6409 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6410 		j_errno = ext4_commit_super(sb);
6411 		if (j_errno)
6412 			return j_errno;
6413 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6414 
6415 		jbd2_journal_clear_err(journal);
6416 		jbd2_journal_update_sb_errno(journal);
6417 	}
6418 	return 0;
6419 }
6420 
6421 /*
6422  * Force the running and committing transactions to commit,
6423  * and wait on the commit.
6424  */
6425 int ext4_force_commit(struct super_block *sb)
6426 {
6427 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6428 }
6429 
6430 static int ext4_sync_fs(struct super_block *sb, int wait)
6431 {
6432 	int ret = 0;
6433 	tid_t target;
6434 	bool needs_barrier = false;
6435 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6436 
6437 	ret = ext4_emergency_state(sb);
6438 	if (unlikely(ret))
6439 		return ret;
6440 
6441 	trace_ext4_sync_fs(sb, wait);
6442 	flush_workqueue(sbi->rsv_conversion_wq);
6443 	/*
6444 	 * Writeback quota in non-journalled quota case - journalled quota has
6445 	 * no dirty dquots
6446 	 */
6447 	dquot_writeback_dquots(sb, -1);
6448 	/*
6449 	 * Data writeback is possible w/o journal transaction, so barrier must
6450 	 * being sent at the end of the function. But we can skip it if
6451 	 * transaction_commit will do it for us.
6452 	 */
6453 	if (sbi->s_journal) {
6454 		target = jbd2_get_latest_transaction(sbi->s_journal);
6455 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6456 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6457 			needs_barrier = true;
6458 
6459 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6460 			if (wait)
6461 				ret = jbd2_log_wait_commit(sbi->s_journal,
6462 							   target);
6463 		}
6464 	} else if (wait && test_opt(sb, BARRIER))
6465 		needs_barrier = true;
6466 	if (needs_barrier) {
6467 		int err;
6468 		err = blkdev_issue_flush(sb->s_bdev);
6469 		if (!ret)
6470 			ret = err;
6471 	}
6472 
6473 	return ret;
6474 }
6475 
6476 /*
6477  * LVM calls this function before a (read-only) snapshot is created.  This
6478  * gives us a chance to flush the journal completely and mark the fs clean.
6479  *
6480  * Note that only this function cannot bring a filesystem to be in a clean
6481  * state independently. It relies on upper layer to stop all data & metadata
6482  * modifications.
6483  */
6484 static int ext4_freeze(struct super_block *sb)
6485 {
6486 	int error = 0;
6487 	journal_t *journal = EXT4_SB(sb)->s_journal;
6488 
6489 	if (journal) {
6490 		/* Now we set up the journal barrier. */
6491 		jbd2_journal_lock_updates(journal);
6492 
6493 		/*
6494 		 * Don't clear the needs_recovery flag if we failed to
6495 		 * flush the journal.
6496 		 */
6497 		error = jbd2_journal_flush(journal, 0);
6498 		if (error < 0)
6499 			goto out;
6500 
6501 		/* Journal blocked and flushed, clear needs_recovery flag. */
6502 		ext4_clear_feature_journal_needs_recovery(sb);
6503 		if (ext4_orphan_file_empty(sb))
6504 			ext4_clear_feature_orphan_present(sb);
6505 	}
6506 
6507 	error = ext4_commit_super(sb);
6508 out:
6509 	if (journal)
6510 		/* we rely on upper layer to stop further updates */
6511 		jbd2_journal_unlock_updates(journal);
6512 	return error;
6513 }
6514 
6515 /*
6516  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6517  * flag here, even though the filesystem is not technically dirty yet.
6518  */
6519 static int ext4_unfreeze(struct super_block *sb)
6520 {
6521 	if (ext4_emergency_state(sb))
6522 		return 0;
6523 
6524 	if (EXT4_SB(sb)->s_journal) {
6525 		/* Reset the needs_recovery flag before the fs is unlocked. */
6526 		ext4_set_feature_journal_needs_recovery(sb);
6527 		if (ext4_has_feature_orphan_file(sb))
6528 			ext4_set_feature_orphan_present(sb);
6529 	}
6530 
6531 	ext4_commit_super(sb);
6532 	return 0;
6533 }
6534 
6535 /*
6536  * Structure to save mount options for ext4_remount's benefit
6537  */
6538 struct ext4_mount_options {
6539 	unsigned long s_mount_opt;
6540 	unsigned long s_mount_opt2;
6541 	kuid_t s_resuid;
6542 	kgid_t s_resgid;
6543 	unsigned long s_commit_interval;
6544 	u32 s_min_batch_time, s_max_batch_time;
6545 #ifdef CONFIG_QUOTA
6546 	int s_jquota_fmt;
6547 	char *s_qf_names[EXT4_MAXQUOTAS];
6548 #endif
6549 };
6550 
6551 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6552 {
6553 	struct ext4_fs_context *ctx = fc->fs_private;
6554 	struct ext4_super_block *es;
6555 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6556 	unsigned long old_sb_flags;
6557 	struct ext4_mount_options old_opts;
6558 	ext4_group_t g;
6559 	int err = 0;
6560 	int alloc_ctx;
6561 #ifdef CONFIG_QUOTA
6562 	int enable_quota = 0;
6563 	int i, j;
6564 	char *to_free[EXT4_MAXQUOTAS];
6565 #endif
6566 
6567 
6568 	/* Store the original options */
6569 	old_sb_flags = sb->s_flags;
6570 	old_opts.s_mount_opt = sbi->s_mount_opt;
6571 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6572 	old_opts.s_resuid = sbi->s_resuid;
6573 	old_opts.s_resgid = sbi->s_resgid;
6574 	old_opts.s_commit_interval = sbi->s_commit_interval;
6575 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6576 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6577 #ifdef CONFIG_QUOTA
6578 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6579 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6580 		if (sbi->s_qf_names[i]) {
6581 			char *qf_name = get_qf_name(sb, sbi, i);
6582 
6583 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6584 			if (!old_opts.s_qf_names[i]) {
6585 				for (j = 0; j < i; j++)
6586 					kfree(old_opts.s_qf_names[j]);
6587 				return -ENOMEM;
6588 			}
6589 		} else
6590 			old_opts.s_qf_names[i] = NULL;
6591 #endif
6592 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6593 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6594 			ctx->journal_ioprio =
6595 				sbi->s_journal->j_task->io_context->ioprio;
6596 		else
6597 			ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
6598 
6599 	}
6600 
6601 	if ((ctx->spec & EXT4_SPEC_s_stripe) &&
6602 	    ext4_is_stripe_incompatible(sb, ctx->s_stripe)) {
6603 		ext4_msg(sb, KERN_WARNING,
6604 			 "stripe (%lu) is not aligned with cluster size (%u), "
6605 			 "stripe is disabled",
6606 			 ctx->s_stripe, sbi->s_cluster_ratio);
6607 		ctx->s_stripe = 0;
6608 	}
6609 
6610 	/*
6611 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6612 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6613 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6614 	 * here s_writepages_rwsem to avoid race between writepages ops and
6615 	 * remount.
6616 	 */
6617 	alloc_ctx = ext4_writepages_down_write(sb);
6618 	ext4_apply_options(fc, sb);
6619 	ext4_writepages_up_write(sb, alloc_ctx);
6620 
6621 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6622 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6623 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6624 			 "during remount not supported; ignoring");
6625 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6626 	}
6627 
6628 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6629 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6630 			ext4_msg(sb, KERN_ERR, "can't mount with "
6631 				 "both data=journal and delalloc");
6632 			err = -EINVAL;
6633 			goto restore_opts;
6634 		}
6635 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6636 			ext4_msg(sb, KERN_ERR, "can't mount with "
6637 				 "both data=journal and dioread_nolock");
6638 			err = -EINVAL;
6639 			goto restore_opts;
6640 		}
6641 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6642 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6643 			ext4_msg(sb, KERN_ERR, "can't mount with "
6644 				"journal_async_commit in data=ordered mode");
6645 			err = -EINVAL;
6646 			goto restore_opts;
6647 		}
6648 	}
6649 
6650 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6651 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6652 		err = -EINVAL;
6653 		goto restore_opts;
6654 	}
6655 
6656 	if ((old_opts.s_mount_opt & EXT4_MOUNT_DELALLOC) &&
6657 	    !test_opt(sb, DELALLOC)) {
6658 		ext4_msg(sb, KERN_ERR, "can't disable delalloc during remount");
6659 		err = -EINVAL;
6660 		goto restore_opts;
6661 	}
6662 
6663 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6664 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6665 
6666 	es = sbi->s_es;
6667 
6668 	if (sbi->s_journal) {
6669 		ext4_init_journal_params(sb, sbi->s_journal);
6670 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6671 	}
6672 
6673 	/* Flush outstanding errors before changing fs state */
6674 	flush_work(&sbi->s_sb_upd_work);
6675 
6676 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6677 		if (ext4_emergency_state(sb)) {
6678 			err = -EROFS;
6679 			goto restore_opts;
6680 		}
6681 
6682 		if (fc->sb_flags & SB_RDONLY) {
6683 			err = sync_filesystem(sb);
6684 			if (err < 0)
6685 				goto restore_opts;
6686 			err = dquot_suspend(sb, -1);
6687 			if (err < 0)
6688 				goto restore_opts;
6689 
6690 			/*
6691 			 * First of all, the unconditional stuff we have to do
6692 			 * to disable replay of the journal when we next remount
6693 			 */
6694 			sb->s_flags |= SB_RDONLY;
6695 
6696 			/*
6697 			 * OK, test if we are remounting a valid rw partition
6698 			 * readonly, and if so set the rdonly flag and then
6699 			 * mark the partition as valid again.
6700 			 */
6701 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6702 			    (sbi->s_mount_state & EXT4_VALID_FS))
6703 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6704 
6705 			if (sbi->s_journal) {
6706 				/*
6707 				 * We let remount-ro finish even if marking fs
6708 				 * as clean failed...
6709 				 */
6710 				ext4_mark_recovery_complete(sb, es);
6711 			}
6712 		} else {
6713 			/* Make sure we can mount this feature set readwrite */
6714 			if (ext4_has_feature_readonly(sb) ||
6715 			    !ext4_feature_set_ok(sb, 0)) {
6716 				err = -EROFS;
6717 				goto restore_opts;
6718 			}
6719 			/*
6720 			 * Make sure the group descriptor checksums
6721 			 * are sane.  If they aren't, refuse to remount r/w.
6722 			 */
6723 			for (g = 0; g < sbi->s_groups_count; g++) {
6724 				struct ext4_group_desc *gdp =
6725 					ext4_get_group_desc(sb, g, NULL);
6726 
6727 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6728 					ext4_msg(sb, KERN_ERR,
6729 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6730 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6731 					       le16_to_cpu(gdp->bg_checksum));
6732 					err = -EFSBADCRC;
6733 					goto restore_opts;
6734 				}
6735 			}
6736 
6737 			/*
6738 			 * If we have an unprocessed orphan list hanging
6739 			 * around from a previously readonly bdev mount,
6740 			 * require a full umount/remount for now.
6741 			 */
6742 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6743 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6744 				       "remount RDWR because of unprocessed "
6745 				       "orphan inode list.  Please "
6746 				       "umount/remount instead");
6747 				err = -EINVAL;
6748 				goto restore_opts;
6749 			}
6750 
6751 			/*
6752 			 * Mounting a RDONLY partition read-write, so reread
6753 			 * and store the current valid flag.  (It may have
6754 			 * been changed by e2fsck since we originally mounted
6755 			 * the partition.)
6756 			 */
6757 			if (sbi->s_journal) {
6758 				err = ext4_clear_journal_err(sb, es);
6759 				if (err)
6760 					goto restore_opts;
6761 			}
6762 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6763 					      ~EXT4_FC_REPLAY);
6764 
6765 			err = ext4_setup_super(sb, es, 0);
6766 			if (err)
6767 				goto restore_opts;
6768 
6769 			sb->s_flags &= ~SB_RDONLY;
6770 			if (ext4_has_feature_mmp(sb)) {
6771 				err = ext4_multi_mount_protect(sb,
6772 						le64_to_cpu(es->s_mmp_block));
6773 				if (err)
6774 					goto restore_opts;
6775 			}
6776 #ifdef CONFIG_QUOTA
6777 			enable_quota = 1;
6778 #endif
6779 		}
6780 	}
6781 
6782 	/*
6783 	 * Handle creation of system zone data early because it can fail.
6784 	 * Releasing of existing data is done when we are sure remount will
6785 	 * succeed.
6786 	 */
6787 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6788 		err = ext4_setup_system_zone(sb);
6789 		if (err)
6790 			goto restore_opts;
6791 	}
6792 
6793 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6794 		err = ext4_commit_super(sb);
6795 		if (err)
6796 			goto restore_opts;
6797 	}
6798 
6799 #ifdef CONFIG_QUOTA
6800 	if (enable_quota) {
6801 		if (sb_any_quota_suspended(sb))
6802 			dquot_resume(sb, -1);
6803 		else if (ext4_has_feature_quota(sb)) {
6804 			err = ext4_enable_quotas(sb);
6805 			if (err)
6806 				goto restore_opts;
6807 		}
6808 	}
6809 	/* Release old quota file names */
6810 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6811 		kfree(old_opts.s_qf_names[i]);
6812 #endif
6813 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6814 		ext4_release_system_zone(sb);
6815 
6816 	/*
6817 	 * Reinitialize lazy itable initialization thread based on
6818 	 * current settings
6819 	 */
6820 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6821 		ext4_unregister_li_request(sb);
6822 	else {
6823 		ext4_group_t first_not_zeroed;
6824 		first_not_zeroed = ext4_has_uninit_itable(sb);
6825 		ext4_register_li_request(sb, first_not_zeroed);
6826 	}
6827 
6828 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6829 		ext4_stop_mmpd(sbi);
6830 
6831 	/*
6832 	 * Handle aborting the filesystem as the last thing during remount to
6833 	 * avoid obsure errors during remount when some option changes fail to
6834 	 * apply due to shutdown filesystem.
6835 	 */
6836 	if (test_opt2(sb, ABORT))
6837 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6838 
6839 	return 0;
6840 
6841 restore_opts:
6842 	/*
6843 	 * If there was a failing r/w to ro transition, we may need to
6844 	 * re-enable quota
6845 	 */
6846 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6847 	    sb_any_quota_suspended(sb))
6848 		dquot_resume(sb, -1);
6849 
6850 	alloc_ctx = ext4_writepages_down_write(sb);
6851 	sb->s_flags = old_sb_flags;
6852 	sbi->s_mount_opt = old_opts.s_mount_opt;
6853 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6854 	sbi->s_resuid = old_opts.s_resuid;
6855 	sbi->s_resgid = old_opts.s_resgid;
6856 	sbi->s_commit_interval = old_opts.s_commit_interval;
6857 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6858 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6859 	ext4_writepages_up_write(sb, alloc_ctx);
6860 
6861 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6862 		ext4_release_system_zone(sb);
6863 #ifdef CONFIG_QUOTA
6864 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6865 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6866 		to_free[i] = get_qf_name(sb, sbi, i);
6867 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6868 	}
6869 	synchronize_rcu();
6870 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6871 		kfree(to_free[i]);
6872 #endif
6873 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6874 		ext4_stop_mmpd(sbi);
6875 	return err;
6876 }
6877 
6878 static int ext4_reconfigure(struct fs_context *fc)
6879 {
6880 	struct super_block *sb = fc->root->d_sb;
6881 	int ret;
6882 	bool old_ro = sb_rdonly(sb);
6883 
6884 	fc->s_fs_info = EXT4_SB(sb);
6885 
6886 	ret = ext4_check_opt_consistency(fc, sb);
6887 	if (ret < 0)
6888 		return ret;
6889 
6890 	ret = __ext4_remount(fc, sb);
6891 	if (ret < 0)
6892 		return ret;
6893 
6894 	ext4_msg(sb, KERN_INFO, "re-mounted %pU%s.",
6895 		 &sb->s_uuid,
6896 		 (old_ro != sb_rdonly(sb)) ? (sb_rdonly(sb) ? " ro" : " r/w") : "");
6897 
6898 	return 0;
6899 }
6900 
6901 #ifdef CONFIG_QUOTA
6902 static int ext4_statfs_project(struct super_block *sb,
6903 			       kprojid_t projid, struct kstatfs *buf)
6904 {
6905 	struct kqid qid;
6906 	struct dquot *dquot;
6907 	u64 limit;
6908 	u64 curblock;
6909 
6910 	qid = make_kqid_projid(projid);
6911 	dquot = dqget(sb, qid);
6912 	if (IS_ERR(dquot))
6913 		return PTR_ERR(dquot);
6914 	spin_lock(&dquot->dq_dqb_lock);
6915 
6916 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6917 			     dquot->dq_dqb.dqb_bhardlimit);
6918 	limit >>= sb->s_blocksize_bits;
6919 
6920 	if (limit) {
6921 		uint64_t	remaining = 0;
6922 
6923 		curblock = (dquot->dq_dqb.dqb_curspace +
6924 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6925 		if (limit > curblock)
6926 			remaining = limit - curblock;
6927 
6928 		buf->f_blocks = min(buf->f_blocks, limit);
6929 		buf->f_bfree = min(buf->f_bfree, remaining);
6930 		buf->f_bavail = min(buf->f_bavail, remaining);
6931 	}
6932 
6933 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6934 			     dquot->dq_dqb.dqb_ihardlimit);
6935 	if (limit) {
6936 		uint64_t	remaining = 0;
6937 
6938 		if (limit > dquot->dq_dqb.dqb_curinodes)
6939 			remaining = limit - dquot->dq_dqb.dqb_curinodes;
6940 
6941 		buf->f_files = min(buf->f_files, limit);
6942 		buf->f_ffree = min(buf->f_ffree, remaining);
6943 	}
6944 
6945 	spin_unlock(&dquot->dq_dqb_lock);
6946 	dqput(dquot);
6947 	return 0;
6948 }
6949 #endif
6950 
6951 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6952 {
6953 	struct super_block *sb = dentry->d_sb;
6954 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6955 	struct ext4_super_block *es = sbi->s_es;
6956 	ext4_fsblk_t overhead = 0, resv_blocks;
6957 	s64 bfree;
6958 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6959 
6960 	if (!test_opt(sb, MINIX_DF))
6961 		overhead = sbi->s_overhead;
6962 
6963 	buf->f_type = EXT4_SUPER_MAGIC;
6964 	buf->f_bsize = sb->s_blocksize;
6965 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6966 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6967 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6968 	/* prevent underflow in case that few free space is available */
6969 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6970 	buf->f_bavail = buf->f_bfree -
6971 			(ext4_r_blocks_count(es) + resv_blocks);
6972 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6973 		buf->f_bavail = 0;
6974 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6975 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6976 	buf->f_namelen = EXT4_NAME_LEN;
6977 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6978 
6979 #ifdef CONFIG_QUOTA
6980 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6981 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6982 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6983 #endif
6984 	return 0;
6985 }
6986 
6987 
6988 #ifdef CONFIG_QUOTA
6989 
6990 /*
6991  * Helper functions so that transaction is started before we acquire dqio_sem
6992  * to keep correct lock ordering of transaction > dqio_sem
6993  */
6994 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6995 {
6996 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6997 }
6998 
6999 static int ext4_write_dquot(struct dquot *dquot)
7000 {
7001 	int ret, err;
7002 	handle_t *handle;
7003 	struct inode *inode;
7004 
7005 	inode = dquot_to_inode(dquot);
7006 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
7007 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
7008 	if (IS_ERR(handle))
7009 		return PTR_ERR(handle);
7010 	ret = dquot_commit(dquot);
7011 	if (ret < 0)
7012 		ext4_error_err(dquot->dq_sb, -ret,
7013 			       "Failed to commit dquot type %d",
7014 			       dquot->dq_id.type);
7015 	err = ext4_journal_stop(handle);
7016 	if (!ret)
7017 		ret = err;
7018 	return ret;
7019 }
7020 
7021 static int ext4_acquire_dquot(struct dquot *dquot)
7022 {
7023 	int ret, err;
7024 	handle_t *handle;
7025 
7026 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
7027 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
7028 	if (IS_ERR(handle))
7029 		return PTR_ERR(handle);
7030 	ret = dquot_acquire(dquot);
7031 	if (ret < 0)
7032 		ext4_error_err(dquot->dq_sb, -ret,
7033 			      "Failed to acquire dquot type %d",
7034 			      dquot->dq_id.type);
7035 	err = ext4_journal_stop(handle);
7036 	if (!ret)
7037 		ret = err;
7038 	return ret;
7039 }
7040 
7041 static int ext4_release_dquot(struct dquot *dquot)
7042 {
7043 	int ret, err;
7044 	handle_t *handle;
7045 	bool freeze_protected = false;
7046 
7047 	/*
7048 	 * Trying to sb_start_intwrite() in a running transaction
7049 	 * can result in a deadlock. Further, running transactions
7050 	 * are already protected from freezing.
7051 	 */
7052 	if (!ext4_journal_current_handle()) {
7053 		sb_start_intwrite(dquot->dq_sb);
7054 		freeze_protected = true;
7055 	}
7056 
7057 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
7058 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
7059 	if (IS_ERR(handle)) {
7060 		/* Release dquot anyway to avoid endless cycle in dqput() */
7061 		dquot_release(dquot);
7062 		if (freeze_protected)
7063 			sb_end_intwrite(dquot->dq_sb);
7064 		return PTR_ERR(handle);
7065 	}
7066 	ret = dquot_release(dquot);
7067 	if (ret < 0)
7068 		ext4_error_err(dquot->dq_sb, -ret,
7069 			       "Failed to release dquot type %d",
7070 			       dquot->dq_id.type);
7071 	err = ext4_journal_stop(handle);
7072 	if (!ret)
7073 		ret = err;
7074 
7075 	if (freeze_protected)
7076 		sb_end_intwrite(dquot->dq_sb);
7077 
7078 	return ret;
7079 }
7080 
7081 static int ext4_mark_dquot_dirty(struct dquot *dquot)
7082 {
7083 	struct super_block *sb = dquot->dq_sb;
7084 
7085 	if (ext4_is_quota_journalled(sb)) {
7086 		dquot_mark_dquot_dirty(dquot);
7087 		return ext4_write_dquot(dquot);
7088 	} else {
7089 		return dquot_mark_dquot_dirty(dquot);
7090 	}
7091 }
7092 
7093 static int ext4_write_info(struct super_block *sb, int type)
7094 {
7095 	int ret, err;
7096 	handle_t *handle;
7097 
7098 	/* Data block + inode block */
7099 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
7100 	if (IS_ERR(handle))
7101 		return PTR_ERR(handle);
7102 	ret = dquot_commit_info(sb, type);
7103 	err = ext4_journal_stop(handle);
7104 	if (!ret)
7105 		ret = err;
7106 	return ret;
7107 }
7108 
7109 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
7110 {
7111 	struct ext4_inode_info *ei = EXT4_I(inode);
7112 
7113 	/* The first argument of lockdep_set_subclass has to be
7114 	 * *exactly* the same as the argument to init_rwsem() --- in
7115 	 * this case, in init_once() --- or lockdep gets unhappy
7116 	 * because the name of the lock is set using the
7117 	 * stringification of the argument to init_rwsem().
7118 	 */
7119 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
7120 	lockdep_set_subclass(&ei->i_data_sem, subclass);
7121 }
7122 
7123 /*
7124  * Standard function to be called on quota_on
7125  */
7126 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
7127 			 const struct path *path)
7128 {
7129 	int err;
7130 
7131 	if (!test_opt(sb, QUOTA))
7132 		return -EINVAL;
7133 
7134 	/* Quotafile not on the same filesystem? */
7135 	if (path->dentry->d_sb != sb)
7136 		return -EXDEV;
7137 
7138 	/* Quota already enabled for this file? */
7139 	if (IS_NOQUOTA(d_inode(path->dentry)))
7140 		return -EBUSY;
7141 
7142 	/* Journaling quota? */
7143 	if (EXT4_SB(sb)->s_qf_names[type]) {
7144 		/* Quotafile not in fs root? */
7145 		if (path->dentry->d_parent != sb->s_root)
7146 			ext4_msg(sb, KERN_WARNING,
7147 				"Quota file not on filesystem root. "
7148 				"Journaled quota will not work");
7149 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
7150 	} else {
7151 		/*
7152 		 * Clear the flag just in case mount options changed since
7153 		 * last time.
7154 		 */
7155 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
7156 	}
7157 
7158 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
7159 	err = dquot_quota_on(sb, type, format_id, path);
7160 	if (!err) {
7161 		struct inode *inode = d_inode(path->dentry);
7162 		handle_t *handle;
7163 
7164 		/*
7165 		 * Set inode flags to prevent userspace from messing with quota
7166 		 * files. If this fails, we return success anyway since quotas
7167 		 * are already enabled and this is not a hard failure.
7168 		 */
7169 		inode_lock(inode);
7170 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7171 		if (IS_ERR(handle))
7172 			goto unlock_inode;
7173 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
7174 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
7175 				S_NOATIME | S_IMMUTABLE);
7176 		err = ext4_mark_inode_dirty(handle, inode);
7177 		ext4_journal_stop(handle);
7178 	unlock_inode:
7179 		inode_unlock(inode);
7180 		if (err)
7181 			dquot_quota_off(sb, type);
7182 	}
7183 	if (err)
7184 		lockdep_set_quota_inode(path->dentry->d_inode,
7185 					     I_DATA_SEM_NORMAL);
7186 	return err;
7187 }
7188 
7189 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
7190 {
7191 	switch (type) {
7192 	case USRQUOTA:
7193 		return qf_inum == EXT4_USR_QUOTA_INO;
7194 	case GRPQUOTA:
7195 		return qf_inum == EXT4_GRP_QUOTA_INO;
7196 	case PRJQUOTA:
7197 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7198 	default:
7199 		BUG();
7200 	}
7201 }
7202 
7203 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7204 			     unsigned int flags)
7205 {
7206 	int err;
7207 	struct inode *qf_inode;
7208 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7209 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7210 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7211 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7212 	};
7213 
7214 	BUG_ON(!ext4_has_feature_quota(sb));
7215 
7216 	if (!qf_inums[type])
7217 		return -EPERM;
7218 
7219 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7220 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7221 				qf_inums[type], type);
7222 		return -EUCLEAN;
7223 	}
7224 
7225 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7226 	if (IS_ERR(qf_inode)) {
7227 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7228 				qf_inums[type], type);
7229 		return PTR_ERR(qf_inode);
7230 	}
7231 
7232 	/* Don't account quota for quota files to avoid recursion */
7233 	qf_inode->i_flags |= S_NOQUOTA;
7234 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7235 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7236 	if (err)
7237 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7238 	iput(qf_inode);
7239 
7240 	return err;
7241 }
7242 
7243 /* Enable usage tracking for all quota types. */
7244 int ext4_enable_quotas(struct super_block *sb)
7245 {
7246 	int type, err = 0;
7247 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7248 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7249 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7250 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7251 	};
7252 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7253 		test_opt(sb, USRQUOTA),
7254 		test_opt(sb, GRPQUOTA),
7255 		test_opt(sb, PRJQUOTA),
7256 	};
7257 
7258 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7259 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7260 		if (qf_inums[type]) {
7261 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7262 				DQUOT_USAGE_ENABLED |
7263 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7264 			if (err) {
7265 				ext4_warning(sb,
7266 					"Failed to enable quota tracking "
7267 					"(type=%d, err=%d, ino=%lu). "
7268 					"Please run e2fsck to fix.", type,
7269 					err, qf_inums[type]);
7270 
7271 				ext4_quotas_off(sb, type);
7272 				return err;
7273 			}
7274 		}
7275 	}
7276 	return 0;
7277 }
7278 
7279 static int ext4_quota_off(struct super_block *sb, int type)
7280 {
7281 	struct inode *inode = sb_dqopt(sb)->files[type];
7282 	handle_t *handle;
7283 	int err;
7284 
7285 	/* Force all delayed allocation blocks to be allocated.
7286 	 * Caller already holds s_umount sem */
7287 	if (test_opt(sb, DELALLOC))
7288 		sync_filesystem(sb);
7289 
7290 	if (!inode || !igrab(inode))
7291 		goto out;
7292 
7293 	err = dquot_quota_off(sb, type);
7294 	if (err || ext4_has_feature_quota(sb))
7295 		goto out_put;
7296 	/*
7297 	 * When the filesystem was remounted read-only first, we cannot cleanup
7298 	 * inode flags here. Bad luck but people should be using QUOTA feature
7299 	 * these days anyway.
7300 	 */
7301 	if (sb_rdonly(sb))
7302 		goto out_put;
7303 
7304 	inode_lock(inode);
7305 	/*
7306 	 * Update modification times of quota files when userspace can
7307 	 * start looking at them. If we fail, we return success anyway since
7308 	 * this is not a hard failure and quotas are already disabled.
7309 	 */
7310 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7311 	if (IS_ERR(handle)) {
7312 		err = PTR_ERR(handle);
7313 		goto out_unlock;
7314 	}
7315 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7316 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7317 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
7318 	err = ext4_mark_inode_dirty(handle, inode);
7319 	ext4_journal_stop(handle);
7320 out_unlock:
7321 	inode_unlock(inode);
7322 out_put:
7323 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7324 	iput(inode);
7325 	return err;
7326 out:
7327 	return dquot_quota_off(sb, type);
7328 }
7329 
7330 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7331  * acquiring the locks... As quota files are never truncated and quota code
7332  * itself serializes the operations (and no one else should touch the files)
7333  * we don't have to be afraid of races */
7334 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7335 			       size_t len, loff_t off)
7336 {
7337 	struct inode *inode = sb_dqopt(sb)->files[type];
7338 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7339 	int offset = off & (sb->s_blocksize - 1);
7340 	int tocopy;
7341 	size_t toread;
7342 	struct buffer_head *bh;
7343 	loff_t i_size = i_size_read(inode);
7344 
7345 	if (off > i_size)
7346 		return 0;
7347 	if (off+len > i_size)
7348 		len = i_size-off;
7349 	toread = len;
7350 	while (toread > 0) {
7351 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7352 		bh = ext4_bread(NULL, inode, blk, 0);
7353 		if (IS_ERR(bh))
7354 			return PTR_ERR(bh);
7355 		if (!bh)	/* A hole? */
7356 			memset(data, 0, tocopy);
7357 		else
7358 			memcpy(data, bh->b_data+offset, tocopy);
7359 		brelse(bh);
7360 		offset = 0;
7361 		toread -= tocopy;
7362 		data += tocopy;
7363 		blk++;
7364 	}
7365 	return len;
7366 }
7367 
7368 /* Write to quotafile (we know the transaction is already started and has
7369  * enough credits) */
7370 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7371 				const char *data, size_t len, loff_t off)
7372 {
7373 	struct inode *inode = sb_dqopt(sb)->files[type];
7374 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7375 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7376 	int retries = 0;
7377 	struct buffer_head *bh;
7378 	handle_t *handle = journal_current_handle();
7379 
7380 	if (!handle) {
7381 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7382 			" cancelled because transaction is not started",
7383 			(unsigned long long)off, (unsigned long long)len);
7384 		return -EIO;
7385 	}
7386 	/*
7387 	 * Since we account only one data block in transaction credits,
7388 	 * then it is impossible to cross a block boundary.
7389 	 */
7390 	if (sb->s_blocksize - offset < len) {
7391 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7392 			" cancelled because not block aligned",
7393 			(unsigned long long)off, (unsigned long long)len);
7394 		return -EIO;
7395 	}
7396 
7397 	do {
7398 		bh = ext4_bread(handle, inode, blk,
7399 				EXT4_GET_BLOCKS_CREATE |
7400 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7401 	} while (PTR_ERR(bh) == -ENOSPC &&
7402 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7403 	if (IS_ERR(bh))
7404 		return PTR_ERR(bh);
7405 	if (!bh)
7406 		goto out;
7407 	BUFFER_TRACE(bh, "get write access");
7408 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7409 	if (err) {
7410 		brelse(bh);
7411 		return err;
7412 	}
7413 	lock_buffer(bh);
7414 	memcpy(bh->b_data+offset, data, len);
7415 	flush_dcache_folio(bh->b_folio);
7416 	unlock_buffer(bh);
7417 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7418 	brelse(bh);
7419 out:
7420 	if (inode->i_size < off + len) {
7421 		i_size_write(inode, off + len);
7422 		EXT4_I(inode)->i_disksize = inode->i_size;
7423 		err2 = ext4_mark_inode_dirty(handle, inode);
7424 		if (unlikely(err2 && !err))
7425 			err = err2;
7426 	}
7427 	return err ? err : len;
7428 }
7429 #endif
7430 
7431 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7432 static inline void register_as_ext2(void)
7433 {
7434 	int err = register_filesystem(&ext2_fs_type);
7435 	if (err)
7436 		printk(KERN_WARNING
7437 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7438 }
7439 
7440 static inline void unregister_as_ext2(void)
7441 {
7442 	unregister_filesystem(&ext2_fs_type);
7443 }
7444 
7445 static inline int ext2_feature_set_ok(struct super_block *sb)
7446 {
7447 	if (ext4_has_unknown_ext2_incompat_features(sb))
7448 		return 0;
7449 	if (sb_rdonly(sb))
7450 		return 1;
7451 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7452 		return 0;
7453 	return 1;
7454 }
7455 #else
7456 static inline void register_as_ext2(void) { }
7457 static inline void unregister_as_ext2(void) { }
7458 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7459 #endif
7460 
7461 static inline void register_as_ext3(void)
7462 {
7463 	int err = register_filesystem(&ext3_fs_type);
7464 	if (err)
7465 		printk(KERN_WARNING
7466 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7467 }
7468 
7469 static inline void unregister_as_ext3(void)
7470 {
7471 	unregister_filesystem(&ext3_fs_type);
7472 }
7473 
7474 static inline int ext3_feature_set_ok(struct super_block *sb)
7475 {
7476 	if (ext4_has_unknown_ext3_incompat_features(sb))
7477 		return 0;
7478 	if (!ext4_has_feature_journal(sb))
7479 		return 0;
7480 	if (sb_rdonly(sb))
7481 		return 1;
7482 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7483 		return 0;
7484 	return 1;
7485 }
7486 
7487 static void ext4_kill_sb(struct super_block *sb)
7488 {
7489 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7490 	struct file *bdev_file = sbi ? sbi->s_journal_bdev_file : NULL;
7491 
7492 	kill_block_super(sb);
7493 
7494 	if (bdev_file)
7495 		bdev_fput(bdev_file);
7496 }
7497 
7498 static struct file_system_type ext4_fs_type = {
7499 	.owner			= THIS_MODULE,
7500 	.name			= "ext4",
7501 	.init_fs_context	= ext4_init_fs_context,
7502 	.parameters		= ext4_param_specs,
7503 	.kill_sb		= ext4_kill_sb,
7504 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME |
7505 				  FS_LBS,
7506 };
7507 MODULE_ALIAS_FS("ext4");
7508 
7509 static int __init ext4_init_fs(void)
7510 {
7511 	int err;
7512 
7513 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7514 	ext4_li_info = NULL;
7515 
7516 	/* Build-time check for flags consistency */
7517 	ext4_check_flag_values();
7518 
7519 	err = ext4_init_es();
7520 	if (err)
7521 		return err;
7522 
7523 	err = ext4_init_pending();
7524 	if (err)
7525 		goto out7;
7526 
7527 	err = ext4_init_post_read_processing();
7528 	if (err)
7529 		goto out6;
7530 
7531 	err = ext4_init_pageio();
7532 	if (err)
7533 		goto out5;
7534 
7535 	err = ext4_init_system_zone();
7536 	if (err)
7537 		goto out4;
7538 
7539 	err = ext4_init_sysfs();
7540 	if (err)
7541 		goto out3;
7542 
7543 	err = ext4_init_mballoc();
7544 	if (err)
7545 		goto out2;
7546 	err = init_inodecache();
7547 	if (err)
7548 		goto out1;
7549 
7550 	err = ext4_fc_init_dentry_cache();
7551 	if (err)
7552 		goto out05;
7553 
7554 	register_as_ext3();
7555 	register_as_ext2();
7556 	err = register_filesystem(&ext4_fs_type);
7557 	if (err)
7558 		goto out;
7559 
7560 	return 0;
7561 out:
7562 	unregister_as_ext2();
7563 	unregister_as_ext3();
7564 	ext4_fc_destroy_dentry_cache();
7565 out05:
7566 	destroy_inodecache();
7567 out1:
7568 	ext4_exit_mballoc();
7569 out2:
7570 	ext4_exit_sysfs();
7571 out3:
7572 	ext4_exit_system_zone();
7573 out4:
7574 	ext4_exit_pageio();
7575 out5:
7576 	ext4_exit_post_read_processing();
7577 out6:
7578 	ext4_exit_pending();
7579 out7:
7580 	ext4_exit_es();
7581 
7582 	return err;
7583 }
7584 
7585 static void __exit ext4_exit_fs(void)
7586 {
7587 	ext4_destroy_lazyinit_thread();
7588 	unregister_as_ext2();
7589 	unregister_as_ext3();
7590 	unregister_filesystem(&ext4_fs_type);
7591 	ext4_fc_destroy_dentry_cache();
7592 	destroy_inodecache();
7593 	ext4_exit_mballoc();
7594 	ext4_exit_sysfs();
7595 	ext4_exit_system_zone();
7596 	ext4_exit_pageio();
7597 	ext4_exit_post_read_processing();
7598 	ext4_exit_es();
7599 	ext4_exit_pending();
7600 }
7601 
7602 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7603 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7604 MODULE_LICENSE("GPL");
7605 module_init(ext4_init_fs)
7606 module_exit(ext4_exit_fs)
7607