xref: /linux/fs/ext4/super.c (revision 83f1454877cc292b88baf13c829c16ce6937d120)
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 				  bio_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 	if (!end_io)
180 		end_io = bh_end_read;
181 	bh_submit(bh, REQ_OP_READ | op_flags, end_io);
182 }
183 
184 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
185 			 bio_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 		 bio_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 #ifdef CONFIG_LOCKDEP
1435 	lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_NORMAL);
1436 #endif
1437 	return &ei->vfs_inode;
1438 }
1439 
1440 static int ext4_drop_inode(struct inode *inode)
1441 {
1442 	int drop = inode_generic_drop(inode);
1443 
1444 	if (!drop)
1445 		drop = fscrypt_drop_inode(inode);
1446 
1447 	trace_ext4_drop_inode(inode, drop);
1448 	return drop;
1449 }
1450 
1451 static void ext4_free_in_core_inode(struct inode *inode)
1452 {
1453 	fscrypt_free_inode(inode);
1454 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1455 		pr_warn("%s: inode %llu still in fc list",
1456 			__func__, inode->i_ino);
1457 	}
1458 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1459 }
1460 
1461 static void ext4_destroy_inode(struct inode *inode)
1462 {
1463 	if (ext4_inode_orphan_tracked(inode)) {
1464 		ext4_msg(inode->i_sb, KERN_ERR,
1465 			 "Inode %llu (%p): inode tracked as orphan!",
1466 			 inode->i_ino, EXT4_I(inode));
1467 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1468 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1469 				true);
1470 		dump_stack();
1471 	}
1472 
1473 	if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
1474 	    WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
1475 		ext4_msg(inode->i_sb, KERN_ERR,
1476 			 "Inode %llu (%p): i_reserved_data_blocks (%u) not cleared!",
1477 			 inode->i_ino, EXT4_I(inode),
1478 			 EXT4_I(inode)->i_reserved_data_blocks);
1479 }
1480 
1481 static void ext4_shutdown(struct super_block *sb)
1482 {
1483        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1484 }
1485 
1486 static void init_once(void *foo)
1487 {
1488 	struct ext4_inode_info *ei = foo;
1489 
1490 	INIT_LIST_HEAD(&ei->i_orphan);
1491 	init_rwsem(&ei->xattr_sem);
1492 	init_rwsem(&ei->i_data_sem);
1493 	inode_init_once(&ei->vfs_inode);
1494 	ext4_fc_init_inode(&ei->vfs_inode);
1495 #ifdef CONFIG_FS_ENCRYPTION
1496 	ei->i_crypt_info = NULL;
1497 #endif
1498 }
1499 
1500 static int __init init_inodecache(void)
1501 {
1502 	struct kmem_cache_args args = {
1503 		.useroffset = offsetof(struct ext4_inode_info, i_data),
1504 		.usersize = sizeof_field(struct ext4_inode_info, i_data),
1505 		.use_freeptr_offset = true,
1506 		.freeptr_offset = offsetof(struct ext4_inode_info, i_flags),
1507 		.ctor = init_once,
1508 	};
1509 
1510 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1511 				sizeof(struct ext4_inode_info),
1512 				&args,
1513 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT);
1514 
1515 	if (ext4_inode_cachep == NULL)
1516 		return -ENOMEM;
1517 	return 0;
1518 }
1519 
1520 static void destroy_inodecache(void)
1521 {
1522 	/*
1523 	 * Make sure all delayed rcu free inodes are flushed before we
1524 	 * destroy cache.
1525 	 */
1526 	rcu_barrier();
1527 	kmem_cache_destroy(ext4_inode_cachep);
1528 }
1529 
1530 void ext4_clear_inode(struct inode *inode)
1531 {
1532 	ext4_fc_del(inode);
1533 	if (!EXT4_SB(inode->i_sb)->s_journal)
1534 		mmb_invalidate(&EXT4_I(inode)->i_metadata_bhs);
1535 	clear_inode(inode);
1536 	ext4_discard_preallocations(inode);
1537 	/*
1538 	 * We must remove the inode from the hash before ext4_free_inode()
1539 	 * clears the bit in inode bitmap as otherwise another process reusing
1540 	 * the inode will block in insert_inode_hash() waiting for inode
1541 	 * eviction to complete while holding transaction handle open, but
1542 	 * ext4_evict_inode() still running for that inode could block waiting
1543 	 * for transaction commit if the inode is marked as IS_SYNC => deadlock.
1544 	 *
1545 	 * Removing the inode from the hash here is safe. There are two cases
1546 	 * to consider:
1547 	 * 1) The inode still has references to it (i_nlink > 0). In that case
1548 	 * we are keeping the inode and once we remove the inode from the hash,
1549 	 * iget() can create the new inode structure for the same inode number
1550 	 * and we are fine with that as all IO on behalf of the inode is
1551 	 * finished.
1552 	 * 2) We are deleting the inode (i_nlink == 0). In that case inode
1553 	 * number cannot be reused until ext4_free_inode() clears the bit in
1554 	 * the inode bitmap, at which point all IO is done and reuse is fine
1555 	 * again.
1556 	 */
1557 	remove_inode_hash(inode);
1558 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1559 	dquot_drop(inode);
1560 	if (EXT4_I(inode)->jinode) {
1561 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1562 					       EXT4_I(inode)->jinode);
1563 		jbd2_free_inode(EXT4_I(inode)->jinode);
1564 		EXT4_I(inode)->jinode = NULL;
1565 	}
1566 	fscrypt_put_encryption_info(inode);
1567 }
1568 
1569 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1570 					u64 ino, u32 generation)
1571 {
1572 	struct inode *inode;
1573 
1574 	/*
1575 	 * Currently we don't know the generation for parent directory, so
1576 	 * a generation of 0 means "accept any"
1577 	 */
1578 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1579 	if (IS_ERR(inode))
1580 		return ERR_CAST(inode);
1581 	if (generation && inode->i_generation != generation) {
1582 		iput(inode);
1583 		return ERR_PTR(-ESTALE);
1584 	}
1585 
1586 	return inode;
1587 }
1588 
1589 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1590 					int fh_len, int fh_type)
1591 {
1592 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1593 				    ext4_nfs_get_inode);
1594 }
1595 
1596 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1597 					int fh_len, int fh_type)
1598 {
1599 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1600 				    ext4_nfs_get_inode);
1601 }
1602 
1603 static int ext4_nfs_commit_metadata(struct inode *inode)
1604 {
1605 	struct writeback_control wbc = {
1606 		.sync_mode = WB_SYNC_ALL
1607 	};
1608 
1609 	trace_ext4_nfs_commit_metadata(inode);
1610 	return ext4_write_inode(inode, &wbc);
1611 }
1612 
1613 #ifdef CONFIG_QUOTA
1614 static const char * const quotatypes[] = INITQFNAMES;
1615 #define QTYPE2NAME(t) (quotatypes[t])
1616 
1617 static int ext4_write_dquot(struct dquot *dquot);
1618 static int ext4_acquire_dquot(struct dquot *dquot);
1619 static int ext4_release_dquot(struct dquot *dquot);
1620 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1621 static int ext4_write_info(struct super_block *sb, int type);
1622 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1623 			 const struct path *path);
1624 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1625 			       size_t len, loff_t off);
1626 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1627 				const char *data, size_t len, loff_t off);
1628 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1629 			     unsigned int flags);
1630 
1631 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1632 {
1633 	return EXT4_I(inode)->i_dquot;
1634 }
1635 
1636 static const struct dquot_operations ext4_quota_operations = {
1637 	.get_reserved_space	= ext4_get_reserved_space,
1638 	.write_dquot		= ext4_write_dquot,
1639 	.acquire_dquot		= ext4_acquire_dquot,
1640 	.release_dquot		= ext4_release_dquot,
1641 	.mark_dirty		= ext4_mark_dquot_dirty,
1642 	.write_info		= ext4_write_info,
1643 	.alloc_dquot		= dquot_alloc,
1644 	.destroy_dquot		= dquot_destroy,
1645 	.get_projid		= ext4_get_projid,
1646 	.get_inode_usage	= ext4_get_inode_usage,
1647 	.get_next_id		= dquot_get_next_id,
1648 };
1649 
1650 static const struct quotactl_ops ext4_qctl_operations = {
1651 	.quota_on	= ext4_quota_on,
1652 	.quota_off	= ext4_quota_off,
1653 	.quota_sync	= dquot_quota_sync,
1654 	.get_state	= dquot_get_state,
1655 	.set_info	= dquot_set_dqinfo,
1656 	.get_dqblk	= dquot_get_dqblk,
1657 	.set_dqblk	= dquot_set_dqblk,
1658 	.get_nextdqblk	= dquot_get_next_dqblk,
1659 };
1660 #endif
1661 
1662 static const struct super_operations ext4_sops = {
1663 	.alloc_inode	= ext4_alloc_inode,
1664 	.free_inode	= ext4_free_in_core_inode,
1665 	.destroy_inode	= ext4_destroy_inode,
1666 	.write_inode	= ext4_write_inode,
1667 	.dirty_inode	= ext4_dirty_inode,
1668 	.drop_inode	= ext4_drop_inode,
1669 	.evict_inode	= ext4_evict_inode,
1670 	.put_super	= ext4_put_super,
1671 	.sync_fs	= ext4_sync_fs,
1672 	.freeze_fs	= ext4_freeze,
1673 	.unfreeze_fs	= ext4_unfreeze,
1674 	.statfs		= ext4_statfs,
1675 	.show_options	= ext4_show_options,
1676 	.shutdown	= ext4_shutdown,
1677 #ifdef CONFIG_QUOTA
1678 	.quota_read	= ext4_quota_read,
1679 	.quota_write	= ext4_quota_write,
1680 	.get_dquots	= ext4_get_dquots,
1681 #endif
1682 };
1683 
1684 static const struct export_operations ext4_export_ops = {
1685 	.encode_fh = generic_encode_ino32_fh,
1686 	.fh_to_dentry = ext4_fh_to_dentry,
1687 	.fh_to_parent = ext4_fh_to_parent,
1688 	.get_parent = ext4_get_parent,
1689 	.commit_metadata = ext4_nfs_commit_metadata,
1690 };
1691 
1692 enum {
1693 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1694 	Opt_resgid, Opt_resuid, Opt_sb,
1695 	Opt_nouid32, Opt_debug, Opt_removed,
1696 	Opt_user_xattr, Opt_acl,
1697 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1698 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1699 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1700 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1701 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1702 	Opt_inlinecrypt,
1703 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1704 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1705 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1706 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1707 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1708 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1709 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1710 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1711 	Opt_dioread_nolock, Opt_dioread_lock,
1712 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1713 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1714 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1715 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1716 #ifdef CONFIG_EXT4_DEBUG
1717 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1718 #endif
1719 };
1720 
1721 static const struct constant_table ext4_param_errors[] = {
1722 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1723 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1724 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1725 	{}
1726 };
1727 
1728 static const struct constant_table ext4_param_data[] = {
1729 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1730 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1731 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1732 	{}
1733 };
1734 
1735 static const struct constant_table ext4_param_data_err[] = {
1736 	{"abort",	Opt_data_err_abort},
1737 	{"ignore",	Opt_data_err_ignore},
1738 	{}
1739 };
1740 
1741 static const struct constant_table ext4_param_jqfmt[] = {
1742 	{"vfsold",	QFMT_VFS_OLD},
1743 	{"vfsv0",	QFMT_VFS_V0},
1744 	{"vfsv1",	QFMT_VFS_V1},
1745 	{}
1746 };
1747 
1748 static const struct constant_table ext4_param_dax[] = {
1749 	{"always",	Opt_dax_always},
1750 	{"inode",	Opt_dax_inode},
1751 	{"never",	Opt_dax_never},
1752 	{}
1753 };
1754 
1755 /*
1756  * Mount option specification
1757  * We don't use fsparam_flag_no because of the way we set the
1758  * options and the way we show them in _ext4_show_options(). To
1759  * keep the changes to a minimum, let's keep the negative options
1760  * separate for now.
1761  */
1762 static const struct fs_parameter_spec ext4_param_specs[] = {
1763 	fsparam_flag	("bsddf",		Opt_bsd_df),
1764 	fsparam_flag	("minixdf",		Opt_minix_df),
1765 	fsparam_flag	("grpid",		Opt_grpid),
1766 	fsparam_flag	("bsdgroups",		Opt_grpid),
1767 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1768 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1769 	fsparam_gid	("resgid",		Opt_resgid),
1770 	fsparam_uid	("resuid",		Opt_resuid),
1771 	fsparam_u32	("sb",			Opt_sb),
1772 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1773 	fsparam_flag	("nouid32",		Opt_nouid32),
1774 	fsparam_flag	("debug",		Opt_debug),
1775 	fsparam_flag	("oldalloc",		Opt_removed),
1776 	fsparam_flag	("orlov",		Opt_removed),
1777 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1778 	fsparam_flag	("acl",			Opt_acl),
1779 	fsparam_flag	("norecovery",		Opt_noload),
1780 	fsparam_flag	("noload",		Opt_noload),
1781 	fsparam_flag	("bh",			Opt_removed),
1782 	fsparam_flag	("nobh",		Opt_removed),
1783 	fsparam_u32	("commit",		Opt_commit),
1784 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1785 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1786 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1787 	fsparam_bdev	("journal_path",	Opt_journal_path),
1788 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1789 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1790 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1791 	fsparam_flag	("abort",		Opt_abort),
1792 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1793 	fsparam_enum	("data_err",		Opt_data_err,
1794 						ext4_param_data_err),
1795 	fsparam_string_empty
1796 			("usrjquota",		Opt_usrjquota),
1797 	fsparam_string_empty
1798 			("grpjquota",		Opt_grpjquota),
1799 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1800 	fsparam_flag	("grpquota",		Opt_grpquota),
1801 	fsparam_flag	("quota",		Opt_quota),
1802 	fsparam_flag	("noquota",		Opt_noquota),
1803 	fsparam_flag	("usrquota",		Opt_usrquota),
1804 	fsparam_flag	("prjquota",		Opt_prjquota),
1805 	fsparam_flag	("barrier",		Opt_barrier),
1806 	fsparam_u32	("barrier",		Opt_barrier),
1807 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1808 	fsparam_flag	("i_version",		Opt_removed),
1809 	fsparam_flag	("dax",			Opt_dax),
1810 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1811 	fsparam_u32	("stripe",		Opt_stripe),
1812 	fsparam_flag	("delalloc",		Opt_delalloc),
1813 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1814 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1815 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1816 	fsparam_u32	("debug_want_extra_isize",
1817 						Opt_debug_want_extra_isize),
1818 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1819 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1820 	fsparam_flag	("block_validity",	Opt_block_validity),
1821 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1822 	fsparam_u32	("inode_readahead_blks",
1823 						Opt_inode_readahead_blks),
1824 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1825 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1826 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1827 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1828 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1829 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1830 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1831 	fsparam_flag	("discard",		Opt_discard),
1832 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1833 	fsparam_u32	("init_itable",		Opt_init_itable),
1834 	fsparam_flag	("init_itable",		Opt_init_itable),
1835 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1836 #ifdef CONFIG_EXT4_DEBUG
1837 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1838 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1839 #endif
1840 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1841 	fsparam_flag	("test_dummy_encryption",
1842 						Opt_test_dummy_encryption),
1843 	fsparam_string	("test_dummy_encryption",
1844 						Opt_test_dummy_encryption),
1845 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1846 	fsparam_flag	("nombcache",		Opt_nombcache),
1847 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1848 	fsparam_flag	("prefetch_block_bitmaps",
1849 						Opt_removed),
1850 	fsparam_flag	("no_prefetch_block_bitmaps",
1851 						Opt_no_prefetch_block_bitmaps),
1852 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1853 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1854 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1855 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1856 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1857 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1858 	{}
1859 };
1860 
1861 
1862 #define MOPT_SET	0x0001
1863 #define MOPT_CLEAR	0x0002
1864 #define MOPT_NOSUPPORT	0x0004
1865 #define MOPT_EXPLICIT	0x0008
1866 #ifdef CONFIG_QUOTA
1867 #define MOPT_Q		0
1868 #define MOPT_QFMT	0x0010
1869 #else
1870 #define MOPT_Q		MOPT_NOSUPPORT
1871 #define MOPT_QFMT	MOPT_NOSUPPORT
1872 #endif
1873 #define MOPT_NO_EXT2	0x0020
1874 #define MOPT_NO_EXT3	0x0040
1875 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1876 #define MOPT_SKIP	0x0080
1877 #define	MOPT_2		0x0100
1878 
1879 static const struct mount_opts {
1880 	int	token;
1881 	int	mount_opt;
1882 	int	flags;
1883 } ext4_mount_opts[] = {
1884 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1885 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1886 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1887 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1888 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1889 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1890 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1891 	 MOPT_EXT4_ONLY | MOPT_SET},
1892 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1893 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1894 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1895 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1896 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1897 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1898 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1899 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1900 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1901 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1902 	{Opt_commit, 0, MOPT_NO_EXT2},
1903 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1904 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1905 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1906 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1907 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1908 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1909 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1910 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1911 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1912 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1913 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1914 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1915 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1916 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1917 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1918 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1919 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1920 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1921 	{Opt_data, 0, MOPT_NO_EXT2},
1922 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1923 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1924 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1925 #else
1926 	{Opt_acl, 0, MOPT_NOSUPPORT},
1927 #endif
1928 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1929 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1930 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1931 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1932 							MOPT_SET | MOPT_Q},
1933 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1934 							MOPT_SET | MOPT_Q},
1935 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1936 							MOPT_SET | MOPT_Q},
1937 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1938 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1939 							MOPT_CLEAR | MOPT_Q},
1940 	{Opt_usrjquota, 0, MOPT_Q},
1941 	{Opt_grpjquota, 0, MOPT_Q},
1942 	{Opt_jqfmt, 0, MOPT_QFMT},
1943 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1944 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1945 	 MOPT_SET},
1946 #ifdef CONFIG_EXT4_DEBUG
1947 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1948 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1949 #endif
1950 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1951 	{Opt_err, 0, 0}
1952 };
1953 
1954 #if IS_ENABLED(CONFIG_UNICODE)
1955 static const struct ext4_sb_encodings {
1956 	__u16 magic;
1957 	char *name;
1958 	unsigned int version;
1959 } ext4_sb_encoding_map[] = {
1960 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1961 };
1962 
1963 static const struct ext4_sb_encodings *
1964 ext4_sb_read_encoding(const struct ext4_super_block *es)
1965 {
1966 	__u16 magic = le16_to_cpu(es->s_encoding);
1967 	int i;
1968 
1969 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1970 		if (magic == ext4_sb_encoding_map[i].magic)
1971 			return &ext4_sb_encoding_map[i];
1972 
1973 	return NULL;
1974 }
1975 #endif
1976 
1977 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1978 #define EXT4_SPEC_JQFMT				(1 <<  1)
1979 #define EXT4_SPEC_DATAJ				(1 <<  2)
1980 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1981 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1982 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1983 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1984 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1985 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1986 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1987 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1988 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1989 #define EXT4_SPEC_s_stripe			(1 << 13)
1990 #define EXT4_SPEC_s_resuid			(1 << 14)
1991 #define EXT4_SPEC_s_resgid			(1 << 15)
1992 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1993 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1994 #define EXT4_SPEC_s_sb_block			(1 << 18)
1995 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1996 
1997 struct ext4_fs_context {
1998 	char		*s_qf_names[EXT4_MAXQUOTAS];
1999 	struct fscrypt_dummy_policy dummy_enc_policy;
2000 	int		s_jquota_fmt;	/* Format of quota to use */
2001 #ifdef CONFIG_EXT4_DEBUG
2002 	int s_fc_debug_max_replay;
2003 #endif
2004 	unsigned short	qname_spec;
2005 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
2006 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
2007 	unsigned long	journal_devnum;
2008 	unsigned long	s_commit_interval;
2009 	unsigned long	s_stripe;
2010 	unsigned int	s_inode_readahead_blks;
2011 	unsigned int	s_want_extra_isize;
2012 	unsigned int	s_li_wait_mult;
2013 	unsigned int	s_max_dir_size_kb;
2014 	unsigned int	journal_ioprio;
2015 	unsigned int	vals_s_mount_opt;
2016 	unsigned int	mask_s_mount_opt;
2017 	unsigned int	vals_s_mount_opt2;
2018 	unsigned int	mask_s_mount_opt2;
2019 	unsigned int	opt_flags;	/* MOPT flags */
2020 	unsigned int	spec;
2021 	u32		s_max_batch_time;
2022 	u32		s_min_batch_time;
2023 	kuid_t		s_resuid;
2024 	kgid_t		s_resgid;
2025 	ext4_fsblk_t	s_sb_block;
2026 };
2027 
2028 static void ext4_fc_free(struct fs_context *fc)
2029 {
2030 	struct ext4_fs_context *ctx = fc->fs_private;
2031 	int i;
2032 
2033 	if (!ctx)
2034 		return;
2035 
2036 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2037 		kfree(ctx->s_qf_names[i]);
2038 
2039 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2040 	kfree(ctx);
2041 }
2042 
2043 int ext4_init_fs_context(struct fs_context *fc)
2044 {
2045 	struct ext4_fs_context *ctx;
2046 
2047 	ctx = kzalloc_obj(struct ext4_fs_context);
2048 	if (!ctx)
2049 		return -ENOMEM;
2050 
2051 	fc->fs_private = ctx;
2052 	fc->ops = &ext4_context_ops;
2053 
2054 	/* i_version is always enabled now */
2055 	fc->sb_flags |= SB_I_VERSION;
2056 
2057 	return 0;
2058 }
2059 
2060 #ifdef CONFIG_QUOTA
2061 /*
2062  * Note the name of the specified quota file.
2063  */
2064 static int note_qf_name(struct fs_context *fc, int qtype,
2065 		       struct fs_parameter *param)
2066 {
2067 	struct ext4_fs_context *ctx = fc->fs_private;
2068 	char *qname;
2069 
2070 	if (param->size < 1) {
2071 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2072 		return -EINVAL;
2073 	}
2074 	if (strchr(param->string, '/')) {
2075 		ext4_msg(NULL, KERN_ERR,
2076 			 "quotafile must be on filesystem root");
2077 		return -EINVAL;
2078 	}
2079 	if (ctx->s_qf_names[qtype]) {
2080 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2081 			ext4_msg(NULL, KERN_ERR,
2082 				 "%s quota file already specified",
2083 				 QTYPE2NAME(qtype));
2084 			return -EINVAL;
2085 		}
2086 		return 0;
2087 	}
2088 
2089 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2090 	if (!qname) {
2091 		ext4_msg(NULL, KERN_ERR,
2092 			 "Not enough memory for storing quotafile name");
2093 		return -ENOMEM;
2094 	}
2095 	ctx->s_qf_names[qtype] = qname;
2096 	ctx->qname_spec |= 1 << qtype;
2097 	ctx->spec |= EXT4_SPEC_JQUOTA;
2098 	return 0;
2099 }
2100 
2101 /*
2102  * Clear the name of the specified quota file.
2103  */
2104 static int unnote_qf_name(struct fs_context *fc, int qtype)
2105 {
2106 	struct ext4_fs_context *ctx = fc->fs_private;
2107 
2108 	kfree(ctx->s_qf_names[qtype]);
2109 
2110 	ctx->s_qf_names[qtype] = NULL;
2111 	ctx->qname_spec |= 1 << qtype;
2112 	ctx->spec |= EXT4_SPEC_JQUOTA;
2113 	return 0;
2114 }
2115 #endif
2116 
2117 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2118 					    struct ext4_fs_context *ctx)
2119 {
2120 	int err;
2121 
2122 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2123 		ext4_msg(NULL, KERN_WARNING,
2124 			 "test_dummy_encryption option not supported");
2125 		return -EINVAL;
2126 	}
2127 	err = fscrypt_parse_test_dummy_encryption(param,
2128 						  &ctx->dummy_enc_policy);
2129 	if (err == -EINVAL) {
2130 		ext4_msg(NULL, KERN_WARNING,
2131 			 "Value of option \"%s\" is unrecognized", param->key);
2132 	} else if (err == -EEXIST) {
2133 		ext4_msg(NULL, KERN_WARNING,
2134 			 "Conflicting test_dummy_encryption options");
2135 		return -EINVAL;
2136 	}
2137 	return err;
2138 }
2139 
2140 #define EXT4_SET_CTX(name)						\
2141 static inline __maybe_unused						\
2142 void ctx_set_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2143 {									\
2144 	ctx->mask_s_##name |= flag;					\
2145 	ctx->vals_s_##name |= flag;					\
2146 }
2147 
2148 #define EXT4_CLEAR_CTX(name)						\
2149 static inline __maybe_unused						\
2150 void ctx_clear_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2151 {									\
2152 	ctx->mask_s_##name |= flag;					\
2153 	ctx->vals_s_##name &= ~flag;					\
2154 }
2155 
2156 #define EXT4_TEST_CTX(name)						\
2157 static inline unsigned long						\
2158 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2159 {									\
2160 	return (ctx->vals_s_##name & flag);				\
2161 }
2162 
2163 EXT4_SET_CTX(flags); /* set only */
2164 EXT4_SET_CTX(mount_opt);
2165 EXT4_CLEAR_CTX(mount_opt);
2166 EXT4_TEST_CTX(mount_opt);
2167 EXT4_SET_CTX(mount_opt2);
2168 EXT4_CLEAR_CTX(mount_opt2);
2169 EXT4_TEST_CTX(mount_opt2);
2170 
2171 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2172 {
2173 	struct ext4_fs_context *ctx = fc->fs_private;
2174 	struct fs_parse_result result;
2175 	const struct mount_opts *m;
2176 	int is_remount;
2177 	int token;
2178 
2179 	token = fs_parse(fc, ext4_param_specs, param, &result);
2180 	if (token < 0)
2181 		return token;
2182 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2183 
2184 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2185 		if (token == m->token)
2186 			break;
2187 
2188 	ctx->opt_flags |= m->flags;
2189 
2190 	if (m->flags & MOPT_EXPLICIT) {
2191 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2192 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2193 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2194 			ctx_set_mount_opt2(ctx,
2195 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2196 		} else
2197 			return -EINVAL;
2198 	}
2199 
2200 	if (m->flags & MOPT_NOSUPPORT) {
2201 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2202 			 param->key);
2203 		return 0;
2204 	}
2205 
2206 	switch (token) {
2207 #ifdef CONFIG_QUOTA
2208 	case Opt_usrjquota:
2209 		if (!*param->string)
2210 			return unnote_qf_name(fc, USRQUOTA);
2211 		else
2212 			return note_qf_name(fc, USRQUOTA, param);
2213 	case Opt_grpjquota:
2214 		if (!*param->string)
2215 			return unnote_qf_name(fc, GRPQUOTA);
2216 		else
2217 			return note_qf_name(fc, GRPQUOTA, param);
2218 #endif
2219 	case Opt_sb:
2220 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2221 			ext4_msg(NULL, KERN_WARNING,
2222 				 "Ignoring %s option on remount", param->key);
2223 		} else {
2224 			ctx->s_sb_block = result.uint_32;
2225 			ctx->spec |= EXT4_SPEC_s_sb_block;
2226 		}
2227 		return 0;
2228 	case Opt_removed:
2229 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2230 			 param->key);
2231 		return 0;
2232 	case Opt_inlinecrypt:
2233 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2234 		ctx_set_flags(ctx, SB_INLINECRYPT);
2235 #else
2236 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2237 #endif
2238 		return 0;
2239 	case Opt_errors:
2240 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2241 		ctx_set_mount_opt(ctx, result.uint_32);
2242 		return 0;
2243 #ifdef CONFIG_QUOTA
2244 	case Opt_jqfmt:
2245 		ctx->s_jquota_fmt = result.uint_32;
2246 		ctx->spec |= EXT4_SPEC_JQFMT;
2247 		return 0;
2248 #endif
2249 	case Opt_data:
2250 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2251 		ctx_set_mount_opt(ctx, result.uint_32);
2252 		ctx->spec |= EXT4_SPEC_DATAJ;
2253 		return 0;
2254 	case Opt_commit:
2255 		if (result.uint_32 == 0)
2256 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2257 		else if (result.uint_32 > INT_MAX / HZ) {
2258 			ext4_msg(NULL, KERN_ERR,
2259 				 "Invalid commit interval %d, "
2260 				 "must be smaller than %d",
2261 				 result.uint_32, INT_MAX / HZ);
2262 			return -EINVAL;
2263 		}
2264 		ctx->s_commit_interval = HZ * result.uint_32;
2265 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2266 		return 0;
2267 	case Opt_debug_want_extra_isize:
2268 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2269 			ext4_msg(NULL, KERN_ERR,
2270 				 "Invalid want_extra_isize %d", result.uint_32);
2271 			return -EINVAL;
2272 		}
2273 		ctx->s_want_extra_isize = result.uint_32;
2274 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2275 		return 0;
2276 	case Opt_max_batch_time:
2277 		ctx->s_max_batch_time = result.uint_32;
2278 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2279 		return 0;
2280 	case Opt_min_batch_time:
2281 		ctx->s_min_batch_time = result.uint_32;
2282 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2283 		return 0;
2284 	case Opt_inode_readahead_blks:
2285 		if (result.uint_32 &&
2286 		    (result.uint_32 > (1 << 30) ||
2287 		     !is_power_of_2(result.uint_32))) {
2288 			ext4_msg(NULL, KERN_ERR,
2289 				 "EXT4-fs: inode_readahead_blks must be "
2290 				 "0 or a power of 2 smaller than 2^31");
2291 			return -EINVAL;
2292 		}
2293 		ctx->s_inode_readahead_blks = result.uint_32;
2294 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2295 		return 0;
2296 	case Opt_init_itable:
2297 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2298 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2299 		if (param->type == fs_value_is_string)
2300 			ctx->s_li_wait_mult = result.uint_32;
2301 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2302 		return 0;
2303 	case Opt_max_dir_size_kb:
2304 		ctx->s_max_dir_size_kb = result.uint_32;
2305 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2306 		return 0;
2307 #ifdef CONFIG_EXT4_DEBUG
2308 	case Opt_fc_debug_max_replay:
2309 		ctx->s_fc_debug_max_replay = result.uint_32;
2310 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2311 		return 0;
2312 #endif
2313 	case Opt_stripe:
2314 		ctx->s_stripe = result.uint_32;
2315 		ctx->spec |= EXT4_SPEC_s_stripe;
2316 		return 0;
2317 	case Opt_resuid:
2318 		ctx->s_resuid = result.uid;
2319 		ctx->spec |= EXT4_SPEC_s_resuid;
2320 		return 0;
2321 	case Opt_resgid:
2322 		ctx->s_resgid = result.gid;
2323 		ctx->spec |= EXT4_SPEC_s_resgid;
2324 		return 0;
2325 	case Opt_journal_dev:
2326 		if (is_remount) {
2327 			ext4_msg(NULL, KERN_ERR,
2328 				 "Cannot specify journal on remount");
2329 			return -EINVAL;
2330 		}
2331 		ctx->journal_devnum = result.uint_32;
2332 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2333 		return 0;
2334 	case Opt_journal_path:
2335 	{
2336 		struct inode *journal_inode;
2337 		struct path path;
2338 		int error;
2339 
2340 		if (is_remount) {
2341 			ext4_msg(NULL, KERN_ERR,
2342 				 "Cannot specify journal on remount");
2343 			return -EINVAL;
2344 		}
2345 
2346 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2347 		if (error) {
2348 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2349 				 "journal device path");
2350 			return -EINVAL;
2351 		}
2352 
2353 		journal_inode = d_inode(path.dentry);
2354 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2355 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2356 		path_put(&path);
2357 		return 0;
2358 	}
2359 	case Opt_journal_ioprio:
2360 		if (result.uint_32 > 7) {
2361 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2362 				 " (must be 0-7)");
2363 			return -EINVAL;
2364 		}
2365 		ctx->journal_ioprio =
2366 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2367 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2368 		return 0;
2369 	case Opt_test_dummy_encryption:
2370 		return ext4_parse_test_dummy_encryption(param, ctx);
2371 	case Opt_dax:
2372 	case Opt_dax_type:
2373 #ifdef CONFIG_FS_DAX
2374 	{
2375 		int type = (token == Opt_dax) ?
2376 			   Opt_dax : result.uint_32;
2377 
2378 		switch (type) {
2379 		case Opt_dax:
2380 		case Opt_dax_always:
2381 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2382 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2383 			break;
2384 		case Opt_dax_never:
2385 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2386 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2387 			break;
2388 		case Opt_dax_inode:
2389 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2390 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2391 			/* Strictly for printing options */
2392 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2393 			break;
2394 		}
2395 		return 0;
2396 	}
2397 #else
2398 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2399 		return -EINVAL;
2400 #endif
2401 	case Opt_data_err:
2402 		if (result.uint_32 == Opt_data_err_abort)
2403 			ctx_set_mount_opt(ctx, m->mount_opt);
2404 		else if (result.uint_32 == Opt_data_err_ignore)
2405 			ctx_clear_mount_opt(ctx, m->mount_opt);
2406 		return 0;
2407 	case Opt_mb_optimize_scan:
2408 		if (result.int_32 == 1) {
2409 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2410 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2411 		} else if (result.int_32 == 0) {
2412 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2413 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2414 		} else {
2415 			ext4_msg(NULL, KERN_WARNING,
2416 				 "mb_optimize_scan should be set to 0 or 1.");
2417 			return -EINVAL;
2418 		}
2419 		return 0;
2420 	}
2421 
2422 	/*
2423 	 * At this point we should only be getting options requiring MOPT_SET,
2424 	 * or MOPT_CLEAR. Anything else is a bug
2425 	 */
2426 	if (m->token == Opt_err) {
2427 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2428 			 param->key);
2429 		WARN_ON(1);
2430 		return -EINVAL;
2431 	}
2432 
2433 	else {
2434 		unsigned int set = 0;
2435 
2436 		if ((param->type == fs_value_is_flag) ||
2437 		    result.uint_32 > 0)
2438 			set = 1;
2439 
2440 		if (m->flags & MOPT_CLEAR)
2441 			set = !set;
2442 		else if (unlikely(!(m->flags & MOPT_SET))) {
2443 			ext4_msg(NULL, KERN_WARNING,
2444 				 "buggy handling of option %s",
2445 				 param->key);
2446 			WARN_ON(1);
2447 			return -EINVAL;
2448 		}
2449 		if (m->flags & MOPT_2) {
2450 			if (set != 0)
2451 				ctx_set_mount_opt2(ctx, m->mount_opt);
2452 			else
2453 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2454 		} else {
2455 			if (set != 0)
2456 				ctx_set_mount_opt(ctx, m->mount_opt);
2457 			else
2458 				ctx_clear_mount_opt(ctx, m->mount_opt);
2459 		}
2460 	}
2461 
2462 	return 0;
2463 }
2464 
2465 static int parse_options(struct fs_context *fc, char *options)
2466 {
2467 	struct fs_parameter param;
2468 	int ret;
2469 	char *key;
2470 
2471 	if (!options)
2472 		return 0;
2473 
2474 	while ((key = strsep(&options, ",")) != NULL) {
2475 		if (*key) {
2476 			size_t v_len = 0;
2477 			char *value = strchr(key, '=');
2478 
2479 			param.type = fs_value_is_flag;
2480 			param.string = NULL;
2481 
2482 			if (value) {
2483 				if (value == key)
2484 					continue;
2485 
2486 				*value++ = 0;
2487 				v_len = strlen(value);
2488 				param.string = kmemdup_nul(value, v_len,
2489 							   GFP_KERNEL);
2490 				if (!param.string)
2491 					return -ENOMEM;
2492 				param.type = fs_value_is_string;
2493 			}
2494 
2495 			param.key = key;
2496 			param.size = v_len;
2497 
2498 			ret = ext4_parse_param(fc, &param);
2499 			kfree(param.string);
2500 			if (ret < 0)
2501 				return ret;
2502 		}
2503 	}
2504 
2505 	ret = ext4_validate_options(fc);
2506 	if (ret < 0)
2507 		return ret;
2508 
2509 	return 0;
2510 }
2511 
2512 static int parse_apply_sb_mount_options(struct super_block *sb,
2513 					struct ext4_fs_context *m_ctx)
2514 {
2515 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2516 	char s_mount_opts[64];
2517 	struct ext4_fs_context *s_ctx = NULL;
2518 	struct fs_context *fc = NULL;
2519 	int ret = -ENOMEM;
2520 
2521 	if (!sbi->s_es->s_mount_opts[0])
2522 		return 0;
2523 
2524 	if (strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts) < 0)
2525 		return -E2BIG;
2526 
2527 	fc = kzalloc_obj(struct fs_context);
2528 	if (!fc)
2529 		return -ENOMEM;
2530 
2531 	s_ctx = kzalloc_obj(struct ext4_fs_context);
2532 	if (!s_ctx)
2533 		goto out_free;
2534 
2535 	fc->fs_private = s_ctx;
2536 	fc->s_fs_info = sbi;
2537 
2538 	ret = parse_options(fc, s_mount_opts);
2539 	if (ret < 0)
2540 		goto parse_failed;
2541 
2542 	ret = ext4_check_opt_consistency(fc, sb);
2543 	if (ret < 0) {
2544 parse_failed:
2545 		ext4_msg(sb, KERN_WARNING,
2546 			 "failed to parse options in superblock: %s",
2547 			 s_mount_opts);
2548 		ret = 0;
2549 		goto out_free;
2550 	}
2551 
2552 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2553 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2554 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2555 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2556 
2557 	ext4_apply_options(fc, sb);
2558 	ret = 0;
2559 
2560 out_free:
2561 	ext4_fc_free(fc);
2562 	kfree(fc);
2563 	return ret;
2564 }
2565 
2566 static void ext4_apply_quota_options(struct fs_context *fc,
2567 				     struct super_block *sb)
2568 {
2569 #ifdef CONFIG_QUOTA
2570 	bool quota_feature = ext4_has_feature_quota(sb);
2571 	struct ext4_fs_context *ctx = fc->fs_private;
2572 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2573 	char *qname;
2574 	int i;
2575 
2576 	if (quota_feature)
2577 		return;
2578 
2579 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2580 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2581 			if (!(ctx->qname_spec & (1 << i)))
2582 				continue;
2583 
2584 			qname = ctx->s_qf_names[i]; /* May be NULL */
2585 			if (qname)
2586 				set_opt(sb, QUOTA);
2587 			ctx->s_qf_names[i] = NULL;
2588 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2589 						lockdep_is_held(&sb->s_umount));
2590 			if (qname)
2591 				kfree_rcu_mightsleep(qname);
2592 		}
2593 	}
2594 
2595 	if (ctx->spec & EXT4_SPEC_JQFMT)
2596 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2597 #endif
2598 }
2599 
2600 /*
2601  * Check quota settings consistency.
2602  */
2603 static int ext4_check_quota_consistency(struct fs_context *fc,
2604 					struct super_block *sb)
2605 {
2606 #ifdef CONFIG_QUOTA
2607 	struct ext4_fs_context *ctx = fc->fs_private;
2608 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2609 	bool quota_feature = ext4_has_feature_quota(sb);
2610 	bool quota_loaded = sb_any_quota_loaded(sb);
2611 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2612 	int quota_flags, i;
2613 
2614 	/*
2615 	 * We do the test below only for project quotas. 'usrquota' and
2616 	 * 'grpquota' mount options are allowed even without quota feature
2617 	 * to support legacy quotas in quota files.
2618 	 */
2619 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2620 	    !ext4_has_feature_project(sb)) {
2621 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2622 			 "Cannot enable project quota enforcement.");
2623 		return -EINVAL;
2624 	}
2625 
2626 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2627 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2628 	if (quota_loaded &&
2629 	    ctx->mask_s_mount_opt & quota_flags &&
2630 	    !ctx_test_mount_opt(ctx, quota_flags))
2631 		goto err_quota_change;
2632 
2633 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2634 
2635 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2636 			if (!(ctx->qname_spec & (1 << i)))
2637 				continue;
2638 
2639 			if (quota_loaded &&
2640 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2641 				goto err_jquota_change;
2642 
2643 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2644 			    strcmp(get_qf_name(sb, sbi, i),
2645 				   ctx->s_qf_names[i]) != 0)
2646 				goto err_jquota_specified;
2647 		}
2648 
2649 		if (quota_feature) {
2650 			ext4_msg(NULL, KERN_INFO,
2651 				 "Journaled quota options ignored when "
2652 				 "QUOTA feature is enabled");
2653 			return 0;
2654 		}
2655 	}
2656 
2657 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2658 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2659 			goto err_jquota_change;
2660 		if (quota_feature) {
2661 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2662 				 "ignored when QUOTA feature is enabled");
2663 			return 0;
2664 		}
2665 	}
2666 
2667 	/* Make sure we don't mix old and new quota format */
2668 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2669 		       ctx->s_qf_names[USRQUOTA]);
2670 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2671 		       ctx->s_qf_names[GRPQUOTA]);
2672 
2673 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2674 		    test_opt(sb, USRQUOTA));
2675 
2676 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2677 		    test_opt(sb, GRPQUOTA));
2678 
2679 	if (usr_qf_name) {
2680 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2681 		usrquota = false;
2682 	}
2683 	if (grp_qf_name) {
2684 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2685 		grpquota = false;
2686 	}
2687 
2688 	if (usr_qf_name || grp_qf_name) {
2689 		if (usrquota || grpquota) {
2690 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2691 				 "format mixing");
2692 			return -EINVAL;
2693 		}
2694 
2695 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2696 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2697 				 "not specified");
2698 			return -EINVAL;
2699 		}
2700 	}
2701 
2702 	return 0;
2703 
2704 err_quota_change:
2705 	ext4_msg(NULL, KERN_ERR,
2706 		 "Cannot change quota options when quota turned on");
2707 	return -EINVAL;
2708 err_jquota_change:
2709 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2710 		 "options when quota turned on");
2711 	return -EINVAL;
2712 err_jquota_specified:
2713 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2714 		 QTYPE2NAME(i));
2715 	return -EINVAL;
2716 #else
2717 	return 0;
2718 #endif
2719 }
2720 
2721 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2722 					    struct super_block *sb)
2723 {
2724 	const struct ext4_fs_context *ctx = fc->fs_private;
2725 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2726 
2727 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2728 		return 0;
2729 
2730 	if (!ext4_has_feature_encrypt(sb)) {
2731 		ext4_msg(NULL, KERN_WARNING,
2732 			 "test_dummy_encryption requires encrypt feature");
2733 		return -EINVAL;
2734 	}
2735 	/*
2736 	 * This mount option is just for testing, and it's not worthwhile to
2737 	 * implement the extra complexity (e.g. RCU protection) that would be
2738 	 * needed to allow it to be set or changed during remount.  We do allow
2739 	 * it to be specified during remount, but only if there is no change.
2740 	 */
2741 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2742 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2743 						 &ctx->dummy_enc_policy))
2744 			return 0;
2745 		ext4_msg(NULL, KERN_WARNING,
2746 			 "Can't set or change test_dummy_encryption on remount");
2747 		return -EINVAL;
2748 	}
2749 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2750 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2751 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2752 						 &ctx->dummy_enc_policy))
2753 			return 0;
2754 		ext4_msg(NULL, KERN_WARNING,
2755 			 "Conflicting test_dummy_encryption options");
2756 		return -EINVAL;
2757 	}
2758 	return 0;
2759 }
2760 
2761 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2762 					     struct super_block *sb)
2763 {
2764 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2765 	    /* if already set, it was already verified to be the same */
2766 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2767 		return;
2768 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2769 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2770 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2771 }
2772 
2773 static int ext4_check_opt_consistency(struct fs_context *fc,
2774 				      struct super_block *sb)
2775 {
2776 	struct ext4_fs_context *ctx = fc->fs_private;
2777 	struct ext4_sb_info *sbi = fc->s_fs_info;
2778 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2779 	int err;
2780 
2781 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2782 		ext4_msg(NULL, KERN_ERR,
2783 			 "Mount option(s) incompatible with ext2");
2784 		return -EINVAL;
2785 	}
2786 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2787 		ext4_msg(NULL, KERN_ERR,
2788 			 "Mount option(s) incompatible with ext3");
2789 		return -EINVAL;
2790 	}
2791 
2792 	if (ctx->s_want_extra_isize >
2793 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2794 		ext4_msg(NULL, KERN_ERR,
2795 			 "Invalid want_extra_isize %d",
2796 			 ctx->s_want_extra_isize);
2797 		return -EINVAL;
2798 	}
2799 
2800 	err = ext4_check_test_dummy_encryption(fc, sb);
2801 	if (err)
2802 		return err;
2803 
2804 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2805 		if (!sbi->s_journal) {
2806 			ext4_msg(NULL, KERN_WARNING,
2807 				 "Remounting file system with no journal "
2808 				 "so ignoring journalled data option");
2809 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2810 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2811 			   test_opt(sb, DATA_FLAGS)) {
2812 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2813 				 "on remount");
2814 			return -EINVAL;
2815 		}
2816 	}
2817 
2818 	if (is_remount) {
2819 		if (!sbi->s_journal &&
2820 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT)) {
2821 			ext4_msg(NULL, KERN_WARNING,
2822 				 "Remounting fs w/o journal so ignoring data_err option");
2823 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT);
2824 		}
2825 
2826 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2827 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2828 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2829 				 "both data=journal and dax");
2830 			return -EINVAL;
2831 		}
2832 
2833 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2834 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2835 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2836 fail_dax_change_remount:
2837 			ext4_msg(NULL, KERN_ERR, "can't change "
2838 				 "dax mount option while remounting");
2839 			return -EINVAL;
2840 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2841 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2842 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2843 			goto fail_dax_change_remount;
2844 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2845 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2846 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2847 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2848 			goto fail_dax_change_remount;
2849 		}
2850 	}
2851 
2852 	return ext4_check_quota_consistency(fc, sb);
2853 }
2854 
2855 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2856 {
2857 	struct ext4_fs_context *ctx = fc->fs_private;
2858 	struct ext4_sb_info *sbi = fc->s_fs_info;
2859 
2860 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2861 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2862 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2863 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2864 	sb->s_flags &= ~ctx->mask_s_flags;
2865 	sb->s_flags |= ctx->vals_s_flags;
2866 
2867 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2868 	APPLY(s_commit_interval);
2869 	APPLY(s_stripe);
2870 	APPLY(s_max_batch_time);
2871 	APPLY(s_min_batch_time);
2872 	APPLY(s_want_extra_isize);
2873 	APPLY(s_inode_readahead_blks);
2874 	APPLY(s_max_dir_size_kb);
2875 	APPLY(s_li_wait_mult);
2876 	APPLY(s_resgid);
2877 	APPLY(s_resuid);
2878 
2879 #ifdef CONFIG_EXT4_DEBUG
2880 	APPLY(s_fc_debug_max_replay);
2881 #endif
2882 
2883 	ext4_apply_quota_options(fc, sb);
2884 	ext4_apply_test_dummy_encryption(ctx, sb);
2885 }
2886 
2887 
2888 static int ext4_validate_options(struct fs_context *fc)
2889 {
2890 #ifdef CONFIG_QUOTA
2891 	struct ext4_fs_context *ctx = fc->fs_private;
2892 	char *usr_qf_name, *grp_qf_name;
2893 
2894 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2895 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2896 
2897 	if (usr_qf_name || grp_qf_name) {
2898 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2899 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2900 
2901 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2902 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2903 
2904 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2905 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2906 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2907 				 "format mixing");
2908 			return -EINVAL;
2909 		}
2910 	}
2911 #endif
2912 	return 1;
2913 }
2914 
2915 static inline void ext4_show_quota_options(struct seq_file *seq,
2916 					   struct super_block *sb)
2917 {
2918 #if defined(CONFIG_QUOTA)
2919 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2920 	char *usr_qf_name, *grp_qf_name;
2921 
2922 	if (sbi->s_jquota_fmt) {
2923 		char *fmtname = "";
2924 
2925 		switch (sbi->s_jquota_fmt) {
2926 		case QFMT_VFS_OLD:
2927 			fmtname = "vfsold";
2928 			break;
2929 		case QFMT_VFS_V0:
2930 			fmtname = "vfsv0";
2931 			break;
2932 		case QFMT_VFS_V1:
2933 			fmtname = "vfsv1";
2934 			break;
2935 		}
2936 		seq_printf(seq, ",jqfmt=%s", fmtname);
2937 	}
2938 
2939 	rcu_read_lock();
2940 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2941 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2942 	if (usr_qf_name)
2943 		seq_show_option(seq, "usrjquota", usr_qf_name);
2944 	if (grp_qf_name)
2945 		seq_show_option(seq, "grpjquota", grp_qf_name);
2946 	rcu_read_unlock();
2947 #endif
2948 }
2949 
2950 static const char *token2str(int token)
2951 {
2952 	const struct fs_parameter_spec *spec;
2953 
2954 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2955 		if (spec->opt == token && !spec->type)
2956 			break;
2957 	return spec->name;
2958 }
2959 
2960 /*
2961  * Show an option if
2962  *  - it's set to a non-default value OR
2963  *  - if the per-sb default is different from the global default
2964  */
2965 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2966 			      int nodefs)
2967 {
2968 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2969 	struct ext4_super_block *es = sbi->s_es;
2970 	int def_errors;
2971 	const struct mount_opts *m;
2972 	char sep = nodefs ? '\n' : ',';
2973 
2974 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2975 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2976 
2977 	if (sbi->s_sb_block != 1)
2978 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2979 
2980 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2981 		int want_set = m->flags & MOPT_SET;
2982 		int opt_2 = m->flags & MOPT_2;
2983 		unsigned int mount_opt, def_mount_opt;
2984 
2985 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2986 		    m->flags & MOPT_SKIP)
2987 			continue;
2988 
2989 		if (opt_2) {
2990 			mount_opt = sbi->s_mount_opt2;
2991 			def_mount_opt = sbi->s_def_mount_opt2;
2992 		} else {
2993 			mount_opt = sbi->s_mount_opt;
2994 			def_mount_opt = sbi->s_def_mount_opt;
2995 		}
2996 		/* skip if same as the default */
2997 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2998 			continue;
2999 		/* select Opt_noFoo vs Opt_Foo */
3000 		if ((want_set &&
3001 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
3002 		    (!want_set && (mount_opt & m->mount_opt)))
3003 			continue;
3004 		SEQ_OPTS_PRINT("%s", token2str(m->token));
3005 	}
3006 
3007 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
3008 	    ext4_get_resuid(es) != EXT4_DEF_RESUID)
3009 		SEQ_OPTS_PRINT("resuid=%u",
3010 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
3011 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
3012 	    ext4_get_resgid(es) != EXT4_DEF_RESGID)
3013 		SEQ_OPTS_PRINT("resgid=%u",
3014 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
3015 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
3016 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3017 		SEQ_OPTS_PUTS("errors=remount-ro");
3018 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3019 		SEQ_OPTS_PUTS("errors=continue");
3020 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3021 		SEQ_OPTS_PUTS("errors=panic");
3022 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3023 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3024 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3025 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3026 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3027 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3028 	if (nodefs && sb->s_flags & SB_I_VERSION)
3029 		SEQ_OPTS_PUTS("i_version");
3030 	if (nodefs || sbi->s_stripe)
3031 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3032 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3033 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3034 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3035 			SEQ_OPTS_PUTS("data=journal");
3036 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3037 			SEQ_OPTS_PUTS("data=ordered");
3038 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3039 			SEQ_OPTS_PUTS("data=writeback");
3040 	}
3041 	if (nodefs ||
3042 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3043 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3044 			       sbi->s_inode_readahead_blks);
3045 
3046 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3047 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3048 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3049 	if (nodefs || sbi->s_max_dir_size_kb)
3050 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3051 	if (test_opt(sb, DATA_ERR_ABORT))
3052 		SEQ_OPTS_PUTS("data_err=abort");
3053 
3054 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3055 
3056 	if (sb->s_flags & SB_INLINECRYPT)
3057 		SEQ_OPTS_PUTS("inlinecrypt");
3058 
3059 	if (test_opt(sb, DAX_ALWAYS)) {
3060 		if (IS_EXT2_SB(sb))
3061 			SEQ_OPTS_PUTS("dax");
3062 		else
3063 			SEQ_OPTS_PUTS("dax=always");
3064 	} else if (test_opt2(sb, DAX_NEVER)) {
3065 		SEQ_OPTS_PUTS("dax=never");
3066 	} else if (test_opt2(sb, DAX_INODE)) {
3067 		SEQ_OPTS_PUTS("dax=inode");
3068 	}
3069 
3070 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3071 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3072 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3073 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3074 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3075 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3076 	}
3077 
3078 	if (nodefs && !test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS))
3079 		SEQ_OPTS_PUTS("prefetch_block_bitmaps");
3080 
3081 	if (ext4_emergency_ro(sb))
3082 		SEQ_OPTS_PUTS("emergency_ro");
3083 
3084 	if (ext4_forced_shutdown(sb))
3085 		SEQ_OPTS_PUTS("shutdown");
3086 
3087 	ext4_show_quota_options(seq, sb);
3088 	return 0;
3089 }
3090 
3091 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3092 {
3093 	return _ext4_show_options(seq, root->d_sb, 0);
3094 }
3095 
3096 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3097 {
3098 	struct super_block *sb = seq->private;
3099 	int rc;
3100 
3101 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3102 	rc = _ext4_show_options(seq, sb, 1);
3103 	seq_putc(seq, '\n');
3104 	return rc;
3105 }
3106 
3107 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3108 			    int read_only)
3109 {
3110 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3111 	int err = 0;
3112 
3113 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3114 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3115 			 "forcing read-only mode");
3116 		err = -EROFS;
3117 		goto done;
3118 	}
3119 	if (read_only)
3120 		goto done;
3121 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3122 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3123 			 "running e2fsck is recommended");
3124 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3125 		ext4_msg(sb, KERN_WARNING,
3126 			 "warning: mounting fs with errors, "
3127 			 "running e2fsck is recommended");
3128 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3129 		 le16_to_cpu(es->s_mnt_count) >=
3130 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3131 		ext4_msg(sb, KERN_WARNING,
3132 			 "warning: maximal mount count reached, "
3133 			 "running e2fsck is recommended");
3134 	else if (le32_to_cpu(es->s_checkinterval) &&
3135 		 (ext4_get_tstamp(es, s_lastcheck) +
3136 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3137 		ext4_msg(sb, KERN_WARNING,
3138 			 "warning: checktime reached, "
3139 			 "running e2fsck is recommended");
3140 	if (!sbi->s_journal)
3141 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3142 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3143 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3144 	le16_add_cpu(&es->s_mnt_count, 1);
3145 	ext4_update_tstamp(es, s_mtime);
3146 	if (sbi->s_journal) {
3147 		ext4_set_feature_journal_needs_recovery(sb);
3148 		if (ext4_has_feature_orphan_file(sb))
3149 			ext4_set_feature_orphan_present(sb);
3150 	}
3151 
3152 	err = ext4_commit_super(sb);
3153 done:
3154 	if (test_opt(sb, DEBUG))
3155 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3156 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3157 			sb->s_blocksize,
3158 			sbi->s_groups_count,
3159 			EXT4_BLOCKS_PER_GROUP(sb),
3160 			EXT4_INODES_PER_GROUP(sb),
3161 			sbi->s_mount_opt, sbi->s_mount_opt2);
3162 	return err;
3163 }
3164 
3165 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3166 {
3167 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3168 	struct flex_groups **old_groups, **new_groups;
3169 	int size, i, j;
3170 
3171 	if (!sbi->s_log_groups_per_flex)
3172 		return 0;
3173 
3174 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3175 	if (size <= sbi->s_flex_groups_allocated)
3176 		return 0;
3177 
3178 	new_groups = kvzalloc(roundup_pow_of_two(size *
3179 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3180 	if (!new_groups) {
3181 		ext4_msg(sb, KERN_ERR,
3182 			 "not enough memory for %d flex group pointers", size);
3183 		return -ENOMEM;
3184 	}
3185 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3186 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3187 					 sizeof(struct flex_groups)),
3188 					 GFP_KERNEL);
3189 		if (!new_groups[i]) {
3190 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3191 				kvfree(new_groups[j]);
3192 			kvfree(new_groups);
3193 			ext4_msg(sb, KERN_ERR,
3194 				 "not enough memory for %d flex groups", size);
3195 			return -ENOMEM;
3196 		}
3197 	}
3198 	rcu_read_lock();
3199 	old_groups = rcu_dereference(sbi->s_flex_groups);
3200 	if (old_groups)
3201 		memcpy(new_groups, old_groups,
3202 		       (sbi->s_flex_groups_allocated *
3203 			sizeof(struct flex_groups *)));
3204 	rcu_read_unlock();
3205 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3206 	sbi->s_flex_groups_allocated = size;
3207 	if (old_groups)
3208 		ext4_kvfree_array_rcu(old_groups);
3209 	return 0;
3210 }
3211 
3212 static int ext4_fill_flex_info(struct super_block *sb)
3213 {
3214 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3215 	struct ext4_group_desc *gdp = NULL;
3216 	struct flex_groups *fg;
3217 	ext4_group_t flex_group;
3218 	int i, err;
3219 
3220 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3221 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3222 		sbi->s_log_groups_per_flex = 0;
3223 		return 1;
3224 	}
3225 
3226 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3227 	if (err)
3228 		goto failed;
3229 
3230 	for (i = 0; i < sbi->s_groups_count; i++) {
3231 		gdp = ext4_get_group_desc(sb, i, NULL);
3232 
3233 		flex_group = ext4_flex_group(sbi, i);
3234 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3235 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3236 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3237 			     &fg->free_clusters);
3238 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3239 	}
3240 
3241 	return 1;
3242 failed:
3243 	return 0;
3244 }
3245 
3246 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3247 				   struct ext4_group_desc *gdp)
3248 {
3249 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3250 	__u16 crc = 0;
3251 	__le32 le_group = cpu_to_le32(block_group);
3252 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3253 
3254 	if (ext4_has_feature_metadata_csum(sbi->s_sb)) {
3255 		/* Use new metadata_csum algorithm */
3256 		__u32 csum32;
3257 		__u16 dummy_csum = 0;
3258 
3259 		csum32 = ext4_chksum(sbi->s_csum_seed, (__u8 *)&le_group,
3260 				     sizeof(le_group));
3261 		csum32 = ext4_chksum(csum32, (__u8 *)gdp, offset);
3262 		csum32 = ext4_chksum(csum32, (__u8 *)&dummy_csum,
3263 				     sizeof(dummy_csum));
3264 		offset += sizeof(dummy_csum);
3265 		if (offset < sbi->s_desc_size)
3266 			csum32 = ext4_chksum(csum32, (__u8 *)gdp + offset,
3267 					     sbi->s_desc_size - offset);
3268 
3269 		crc = csum32 & 0xFFFF;
3270 		goto out;
3271 	}
3272 
3273 	/* old crc16 code */
3274 	if (!ext4_has_feature_gdt_csum(sb))
3275 		return 0;
3276 
3277 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3278 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3279 	crc = crc16(crc, (__u8 *)gdp, offset);
3280 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3281 	/* for checksum of struct ext4_group_desc do the rest...*/
3282 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3283 		crc = crc16(crc, (__u8 *)gdp + offset,
3284 			    sbi->s_desc_size - offset);
3285 
3286 out:
3287 	return cpu_to_le16(crc);
3288 }
3289 
3290 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3291 				struct ext4_group_desc *gdp)
3292 {
3293 	if (ext4_has_group_desc_csum(sb) &&
3294 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3295 		return 0;
3296 
3297 	return 1;
3298 }
3299 
3300 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3301 			      struct ext4_group_desc *gdp)
3302 {
3303 	if (!ext4_has_group_desc_csum(sb))
3304 		return;
3305 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3306 }
3307 
3308 /* Called at mount-time, super-block is locked */
3309 static int ext4_check_descriptors(struct super_block *sb,
3310 				  ext4_fsblk_t sb_block,
3311 				  ext4_group_t *first_not_zeroed)
3312 {
3313 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3314 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3315 	ext4_fsblk_t last_block;
3316 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3317 	ext4_fsblk_t block_bitmap;
3318 	ext4_fsblk_t inode_bitmap;
3319 	ext4_fsblk_t inode_table;
3320 	int flexbg_flag = 0;
3321 	ext4_group_t i, grp = sbi->s_groups_count;
3322 
3323 	if (ext4_has_feature_flex_bg(sb))
3324 		flexbg_flag = 1;
3325 
3326 	ext4_debug("Checking group descriptors");
3327 
3328 	for (i = 0; i < sbi->s_groups_count; i++) {
3329 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3330 
3331 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3332 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3333 		else
3334 			last_block = first_block +
3335 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3336 
3337 		if ((grp == sbi->s_groups_count) &&
3338 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3339 			grp = i;
3340 
3341 		block_bitmap = ext4_block_bitmap(sb, gdp);
3342 		if (block_bitmap == sb_block) {
3343 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3344 				 "Block bitmap for group %u overlaps "
3345 				 "superblock", i);
3346 			if (!sb_rdonly(sb))
3347 				return 0;
3348 		}
3349 		if (block_bitmap >= sb_block + 1 &&
3350 		    block_bitmap <= last_bg_block) {
3351 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3352 				 "Block bitmap for group %u overlaps "
3353 				 "block group descriptors", i);
3354 			if (!sb_rdonly(sb))
3355 				return 0;
3356 		}
3357 		if (block_bitmap < first_block || block_bitmap > last_block) {
3358 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3359 			       "Block bitmap for group %u not in group "
3360 			       "(block %llu)!", i, block_bitmap);
3361 			return 0;
3362 		}
3363 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3364 		if (inode_bitmap == sb_block) {
3365 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3366 				 "Inode bitmap for group %u overlaps "
3367 				 "superblock", i);
3368 			if (!sb_rdonly(sb))
3369 				return 0;
3370 		}
3371 		if (inode_bitmap >= sb_block + 1 &&
3372 		    inode_bitmap <= last_bg_block) {
3373 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3374 				 "Inode bitmap for group %u overlaps "
3375 				 "block group descriptors", i);
3376 			if (!sb_rdonly(sb))
3377 				return 0;
3378 		}
3379 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3380 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3381 			       "Inode bitmap for group %u not in group "
3382 			       "(block %llu)!", i, inode_bitmap);
3383 			return 0;
3384 		}
3385 		inode_table = ext4_inode_table(sb, gdp);
3386 		if (inode_table == sb_block) {
3387 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3388 				 "Inode table for group %u overlaps "
3389 				 "superblock", i);
3390 			if (!sb_rdonly(sb))
3391 				return 0;
3392 		}
3393 		if (inode_table >= sb_block + 1 &&
3394 		    inode_table <= last_bg_block) {
3395 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3396 				 "Inode table for group %u overlaps "
3397 				 "block group descriptors", i);
3398 			if (!sb_rdonly(sb))
3399 				return 0;
3400 		}
3401 		if (inode_table < first_block ||
3402 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3403 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3404 			       "Inode table for group %u not in group "
3405 			       "(block %llu)!", i, inode_table);
3406 			return 0;
3407 		}
3408 		ext4_lock_group(sb, i);
3409 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3410 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3411 				 "Checksum for group %u failed (%u!=%u)",
3412 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3413 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3414 			if (!sb_rdonly(sb)) {
3415 				ext4_unlock_group(sb, i);
3416 				return 0;
3417 			}
3418 		}
3419 		ext4_unlock_group(sb, i);
3420 		if (!flexbg_flag)
3421 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3422 	}
3423 	if (NULL != first_not_zeroed)
3424 		*first_not_zeroed = grp;
3425 	return 1;
3426 }
3427 
3428 /*
3429  * Maximal extent format file size.
3430  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3431  * extent format containers, within a sector_t, and within i_blocks
3432  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3433  * so that won't be a limiting factor.
3434  *
3435  * However there is other limiting factor. We do store extents in the form
3436  * of starting block and length, hence the resulting length of the extent
3437  * covering maximum file size must fit into on-disk format containers as
3438  * well. Given that length is always by 1 unit bigger than max unit (because
3439  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3440  *
3441  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3442  */
3443 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3444 {
3445 	loff_t res;
3446 	loff_t upper_limit = MAX_LFS_FILESIZE;
3447 
3448 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3449 
3450 	if (!has_huge_files) {
3451 		upper_limit = (1LL << 32) - 1;
3452 
3453 		/* total blocks in file system block size */
3454 		upper_limit >>= (blkbits - 9);
3455 		upper_limit <<= blkbits;
3456 	}
3457 
3458 	/*
3459 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3460 	 * by one fs block, so ee_len can cover the extent of maximum file
3461 	 * size
3462 	 */
3463 	res = (1LL << 32) - 1;
3464 	res <<= blkbits;
3465 
3466 	/* Sanity check against vm- & vfs- imposed limits */
3467 	if (res > upper_limit)
3468 		res = upper_limit;
3469 
3470 	return res;
3471 }
3472 
3473 /*
3474  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3475  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3476  * We need to be 1 filesystem block less than the 2^48 sector limit.
3477  */
3478 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3479 {
3480 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3481 	int meta_blocks;
3482 	unsigned int ppb = 1 << (bits - 2);
3483 
3484 	/*
3485 	 * This is calculated to be the largest file size for a dense, block
3486 	 * mapped file such that the file's total number of 512-byte sectors,
3487 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3488 	 *
3489 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3490 	 * number of 512-byte sectors of the file.
3491 	 */
3492 	if (!has_huge_files) {
3493 		/*
3494 		 * !has_huge_files or implies that the inode i_block field
3495 		 * represents total file blocks in 2^32 512-byte sectors ==
3496 		 * size of vfs inode i_blocks * 8
3497 		 */
3498 		upper_limit = (1LL << 32) - 1;
3499 
3500 		/* total blocks in file system block size */
3501 		upper_limit >>= (bits - 9);
3502 
3503 	} else {
3504 		/*
3505 		 * We use 48 bit ext4_inode i_blocks
3506 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3507 		 * represent total number of blocks in
3508 		 * file system block size
3509 		 */
3510 		upper_limit = (1LL << 48) - 1;
3511 
3512 	}
3513 
3514 	/* Compute how many blocks we can address by block tree */
3515 	res += ppb;
3516 	res += ppb * ppb;
3517 	res += ((loff_t)ppb) * ppb * ppb;
3518 	/* Compute how many metadata blocks are needed */
3519 	meta_blocks = 1;
3520 	meta_blocks += 1 + ppb;
3521 	meta_blocks += 1 + ppb + ppb * ppb;
3522 	/* Does block tree limit file size? */
3523 	if (res + meta_blocks <= upper_limit)
3524 		goto check_lfs;
3525 
3526 	res = upper_limit;
3527 	/* How many metadata blocks are needed for addressing upper_limit? */
3528 	upper_limit -= EXT4_NDIR_BLOCKS;
3529 	/* indirect blocks */
3530 	meta_blocks = 1;
3531 	upper_limit -= ppb;
3532 	/* double indirect blocks */
3533 	if (upper_limit < ppb * ppb) {
3534 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3535 		res -= meta_blocks;
3536 		goto check_lfs;
3537 	}
3538 	meta_blocks += 1 + ppb;
3539 	upper_limit -= ppb * ppb;
3540 	/* tripple indirect blocks for the rest */
3541 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3542 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3543 	res -= meta_blocks;
3544 check_lfs:
3545 	res <<= bits;
3546 	if (res > MAX_LFS_FILESIZE)
3547 		res = MAX_LFS_FILESIZE;
3548 
3549 	return res;
3550 }
3551 
3552 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3553 				   ext4_fsblk_t logical_sb_block, int nr)
3554 {
3555 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3556 	ext4_group_t bg, first_meta_bg;
3557 	int has_super = 0;
3558 
3559 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3560 
3561 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3562 		return logical_sb_block + nr + 1;
3563 	bg = sbi->s_desc_per_block * nr;
3564 	if (ext4_bg_has_super(sb, bg))
3565 		has_super = 1;
3566 
3567 	/*
3568 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3569 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3570 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3571 	 * compensate.
3572 	 */
3573 	if (sb->s_blocksize == 1024 && nr == 0 &&
3574 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3575 		has_super++;
3576 
3577 	return (has_super + ext4_group_first_block_no(sb, bg));
3578 }
3579 
3580 /**
3581  * ext4_get_stripe_size: Get the stripe size.
3582  * @sbi: In memory super block info
3583  *
3584  * If we have specified it via mount option, then
3585  * use the mount option value. If the value specified at mount time is
3586  * greater than the blocks per group use the super block value.
3587  * If the super block value is greater than blocks per group return 0.
3588  * Allocator needs it be less than blocks per group.
3589  *
3590  */
3591 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3592 {
3593 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3594 	unsigned long stripe_width =
3595 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3596 	int ret;
3597 
3598 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3599 		ret = sbi->s_stripe;
3600 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3601 		ret = stripe_width;
3602 	else if (stride && stride <= sbi->s_blocks_per_group)
3603 		ret = stride;
3604 	else
3605 		ret = 0;
3606 
3607 	/*
3608 	 * If the stripe width is 1, this makes no sense and
3609 	 * we set it to 0 to turn off stripe handling code.
3610 	 */
3611 	if (ret <= 1)
3612 		ret = 0;
3613 
3614 	return ret;
3615 }
3616 
3617 /*
3618  * Check whether this filesystem can be mounted based on
3619  * the features present and the RDONLY/RDWR mount requested.
3620  * Returns 1 if this filesystem can be mounted as requested,
3621  * 0 if it cannot be.
3622  */
3623 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3624 {
3625 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3626 		ext4_msg(sb, KERN_ERR,
3627 			"Couldn't mount because of "
3628 			"unsupported optional features (%x)",
3629 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3630 			~EXT4_FEATURE_INCOMPAT_SUPP));
3631 		return 0;
3632 	}
3633 
3634 	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
3635 		ext4_msg(sb, KERN_ERR,
3636 			 "Filesystem with casefold feature cannot be "
3637 			 "mounted without CONFIG_UNICODE");
3638 		return 0;
3639 	}
3640 
3641 	if (readonly)
3642 		return 1;
3643 
3644 	if (ext4_has_feature_readonly(sb)) {
3645 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3646 		sb->s_flags |= SB_RDONLY;
3647 		return 1;
3648 	}
3649 
3650 	/* Check that feature set is OK for a read-write mount */
3651 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3652 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3653 			 "unsupported optional features (%x)",
3654 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3655 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3656 		return 0;
3657 	}
3658 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3659 		ext4_msg(sb, KERN_ERR,
3660 			 "Can't support bigalloc feature without "
3661 			 "extents feature\n");
3662 		return 0;
3663 	}
3664 	if (ext4_has_feature_bigalloc(sb) &&
3665 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
3666 		ext4_msg(sb, KERN_WARNING,
3667 			 "bad geometry: bigalloc file system with non-zero "
3668 			 "first_data_block\n");
3669 		return 0;
3670 	}
3671 
3672 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3673 	if (!readonly && (ext4_has_feature_quota(sb) ||
3674 			  ext4_has_feature_project(sb))) {
3675 		ext4_msg(sb, KERN_ERR,
3676 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3677 		return 0;
3678 	}
3679 #endif  /* CONFIG_QUOTA */
3680 	return 1;
3681 }
3682 
3683 /*
3684  * This function is called once a day by default if we have errors logged
3685  * on the file system.
3686  * Use the err_report_sec sysfs attribute to disable or adjust its call
3687  * freequency.
3688  */
3689 void print_daily_error_info(struct timer_list *t)
3690 {
3691 	struct ext4_sb_info *sbi = timer_container_of(sbi, t, s_err_report);
3692 	struct super_block *sb = sbi->s_sb;
3693 	struct ext4_super_block *es = sbi->s_es;
3694 
3695 	if (es->s_error_count)
3696 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3697 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3698 			 le32_to_cpu(es->s_error_count));
3699 	if (es->s_first_error_time) {
3700 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3701 		       sb->s_id,
3702 		       ext4_get_tstamp(es, s_first_error_time),
3703 		       (int) sizeof(es->s_first_error_func),
3704 		       es->s_first_error_func,
3705 		       le32_to_cpu(es->s_first_error_line));
3706 		if (es->s_first_error_ino)
3707 			printk(KERN_CONT ": inode %u",
3708 			       le32_to_cpu(es->s_first_error_ino));
3709 		if (es->s_first_error_block)
3710 			printk(KERN_CONT ": block %llu", (unsigned long long)
3711 			       le64_to_cpu(es->s_first_error_block));
3712 		printk(KERN_CONT "\n");
3713 	}
3714 	if (es->s_last_error_time) {
3715 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3716 		       sb->s_id,
3717 		       ext4_get_tstamp(es, s_last_error_time),
3718 		       (int) sizeof(es->s_last_error_func),
3719 		       es->s_last_error_func,
3720 		       le32_to_cpu(es->s_last_error_line));
3721 		if (es->s_last_error_ino)
3722 			printk(KERN_CONT ": inode %u",
3723 			       le32_to_cpu(es->s_last_error_ino));
3724 		if (es->s_last_error_block)
3725 			printk(KERN_CONT ": block %llu", (unsigned long long)
3726 			       le64_to_cpu(es->s_last_error_block));
3727 		printk(KERN_CONT "\n");
3728 	}
3729 
3730 	if (sbi->s_err_report_sec)
3731 		mod_timer(&sbi->s_err_report, jiffies + secs_to_jiffies(sbi->s_err_report_sec));
3732 }
3733 
3734 /* Find next suitable group and run ext4_init_inode_table */
3735 static int ext4_run_li_request(struct ext4_li_request *elr)
3736 {
3737 	struct ext4_group_desc *gdp = NULL;
3738 	struct super_block *sb = elr->lr_super;
3739 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3740 	ext4_group_t group = elr->lr_next_group;
3741 	unsigned int prefetch_ios = 0;
3742 	int ret = 0;
3743 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3744 	u64 start_time;
3745 
3746 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3747 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3748 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3749 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3750 		if (group >= elr->lr_next_group) {
3751 			ret = 1;
3752 			if (elr->lr_first_not_zeroed != ngroups &&
3753 			    !ext4_emergency_state(sb) && !sb_rdonly(sb) &&
3754 			    test_opt(sb, INIT_INODE_TABLE)) {
3755 				elr->lr_next_group = elr->lr_first_not_zeroed;
3756 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3757 				ret = 0;
3758 			}
3759 		}
3760 		return ret;
3761 	}
3762 
3763 	for (; group < ngroups; group++) {
3764 		gdp = ext4_get_group_desc(sb, group, NULL);
3765 		if (!gdp) {
3766 			ret = 1;
3767 			break;
3768 		}
3769 
3770 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3771 			break;
3772 	}
3773 
3774 	if (group >= ngroups)
3775 		ret = 1;
3776 
3777 	if (!ret) {
3778 		start_time = ktime_get_ns();
3779 		ret = ext4_init_inode_table(sb, group,
3780 					    elr->lr_timeout ? 0 : 1);
3781 		trace_ext4_lazy_itable_init(sb, group);
3782 		if (elr->lr_timeout == 0) {
3783 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_ns() - start_time) *
3784 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3785 		}
3786 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3787 		elr->lr_next_group = group + 1;
3788 	}
3789 	return ret;
3790 }
3791 
3792 /*
3793  * Remove lr_request from the list_request and free the
3794  * request structure. Should be called with li_list_mtx held
3795  */
3796 static void ext4_remove_li_request(struct ext4_li_request *elr)
3797 {
3798 	if (!elr)
3799 		return;
3800 
3801 	list_del(&elr->lr_request);
3802 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3803 	kfree(elr);
3804 }
3805 
3806 static void ext4_unregister_li_request(struct super_block *sb)
3807 {
3808 	mutex_lock(&ext4_li_mtx);
3809 	if (!ext4_li_info) {
3810 		mutex_unlock(&ext4_li_mtx);
3811 		return;
3812 	}
3813 
3814 	mutex_lock(&ext4_li_info->li_list_mtx);
3815 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3816 	mutex_unlock(&ext4_li_info->li_list_mtx);
3817 	mutex_unlock(&ext4_li_mtx);
3818 }
3819 
3820 static struct task_struct *ext4_lazyinit_task;
3821 
3822 /*
3823  * This is the function where ext4lazyinit thread lives. It walks
3824  * through the request list searching for next scheduled filesystem.
3825  * When such a fs is found, run the lazy initialization request
3826  * (ext4_rn_li_request) and keep track of the time spend in this
3827  * function. Based on that time we compute next schedule time of
3828  * the request. When walking through the list is complete, compute
3829  * next waking time and put itself into sleep.
3830  */
3831 static int ext4_lazyinit_thread(void *arg)
3832 {
3833 	struct ext4_lazy_init *eli = arg;
3834 	struct list_head *pos, *n;
3835 	struct ext4_li_request *elr;
3836 	unsigned long next_wakeup, cur;
3837 
3838 	BUG_ON(NULL == eli);
3839 	set_freezable();
3840 
3841 cont_thread:
3842 	while (true) {
3843 		bool next_wakeup_initialized = false;
3844 
3845 		next_wakeup = 0;
3846 		mutex_lock(&eli->li_list_mtx);
3847 		if (list_empty(&eli->li_request_list)) {
3848 			mutex_unlock(&eli->li_list_mtx);
3849 			goto exit_thread;
3850 		}
3851 		list_for_each_safe(pos, n, &eli->li_request_list) {
3852 			int err = 0;
3853 			int progress = 0;
3854 			elr = list_entry(pos, struct ext4_li_request,
3855 					 lr_request);
3856 
3857 			if (time_before(jiffies, elr->lr_next_sched)) {
3858 				if (!next_wakeup_initialized ||
3859 				    time_before(elr->lr_next_sched, next_wakeup)) {
3860 					next_wakeup = elr->lr_next_sched;
3861 					next_wakeup_initialized = true;
3862 				}
3863 				continue;
3864 			}
3865 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3866 				if (sb_start_write_trylock(elr->lr_super)) {
3867 					progress = 1;
3868 					/*
3869 					 * We hold sb->s_umount, sb can not
3870 					 * be removed from the list, it is
3871 					 * now safe to drop li_list_mtx
3872 					 */
3873 					mutex_unlock(&eli->li_list_mtx);
3874 					err = ext4_run_li_request(elr);
3875 					sb_end_write(elr->lr_super);
3876 					mutex_lock(&eli->li_list_mtx);
3877 					n = pos->next;
3878 				}
3879 				up_read((&elr->lr_super->s_umount));
3880 			}
3881 			/* error, remove the lazy_init job */
3882 			if (err) {
3883 				ext4_remove_li_request(elr);
3884 				continue;
3885 			}
3886 			if (!progress) {
3887 				elr->lr_next_sched = jiffies +
3888 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3889 			}
3890 			if (!next_wakeup_initialized ||
3891 			    time_before(elr->lr_next_sched, next_wakeup)) {
3892 				next_wakeup = elr->lr_next_sched;
3893 				next_wakeup_initialized = true;
3894 			}
3895 		}
3896 		mutex_unlock(&eli->li_list_mtx);
3897 
3898 		try_to_freeze();
3899 
3900 		cur = jiffies;
3901 		if (!next_wakeup_initialized || time_after_eq(cur, next_wakeup)) {
3902 			cond_resched();
3903 			continue;
3904 		}
3905 
3906 		schedule_timeout_interruptible(next_wakeup - cur);
3907 
3908 		if (kthread_should_stop()) {
3909 			ext4_clear_request_list();
3910 			goto exit_thread;
3911 		}
3912 	}
3913 
3914 exit_thread:
3915 	/*
3916 	 * It looks like the request list is empty, but we need
3917 	 * to check it under the li_list_mtx lock, to prevent any
3918 	 * additions into it, and of course we should lock ext4_li_mtx
3919 	 * to atomically free the list and ext4_li_info, because at
3920 	 * this point another ext4 filesystem could be registering
3921 	 * new one.
3922 	 */
3923 	mutex_lock(&ext4_li_mtx);
3924 	mutex_lock(&eli->li_list_mtx);
3925 	if (!list_empty(&eli->li_request_list)) {
3926 		mutex_unlock(&eli->li_list_mtx);
3927 		mutex_unlock(&ext4_li_mtx);
3928 		goto cont_thread;
3929 	}
3930 	mutex_unlock(&eli->li_list_mtx);
3931 	kfree(ext4_li_info);
3932 	ext4_li_info = NULL;
3933 	mutex_unlock(&ext4_li_mtx);
3934 
3935 	return 0;
3936 }
3937 
3938 static void ext4_clear_request_list(void)
3939 {
3940 	struct list_head *pos, *n;
3941 	struct ext4_li_request *elr;
3942 
3943 	mutex_lock(&ext4_li_info->li_list_mtx);
3944 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3945 		elr = list_entry(pos, struct ext4_li_request,
3946 				 lr_request);
3947 		ext4_remove_li_request(elr);
3948 	}
3949 	mutex_unlock(&ext4_li_info->li_list_mtx);
3950 }
3951 
3952 static int ext4_run_lazyinit_thread(void)
3953 {
3954 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3955 					 ext4_li_info, "ext4lazyinit");
3956 	if (IS_ERR(ext4_lazyinit_task)) {
3957 		int err = PTR_ERR(ext4_lazyinit_task);
3958 		ext4_clear_request_list();
3959 		kfree(ext4_li_info);
3960 		ext4_li_info = NULL;
3961 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3962 				 "initialization thread\n",
3963 				 err);
3964 		return err;
3965 	}
3966 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3967 	return 0;
3968 }
3969 
3970 /*
3971  * Check whether it make sense to run itable init. thread or not.
3972  * If there is at least one uninitialized inode table, return
3973  * corresponding group number, else the loop goes through all
3974  * groups and return total number of groups.
3975  */
3976 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3977 {
3978 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3979 	struct ext4_group_desc *gdp = NULL;
3980 
3981 	if (!ext4_has_group_desc_csum(sb))
3982 		return ngroups;
3983 
3984 	for (group = 0; group < ngroups; group++) {
3985 		gdp = ext4_get_group_desc(sb, group, NULL);
3986 		if (!gdp)
3987 			continue;
3988 
3989 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3990 			break;
3991 	}
3992 
3993 	return group;
3994 }
3995 
3996 static int ext4_li_info_new(void)
3997 {
3998 	struct ext4_lazy_init *eli = NULL;
3999 
4000 	eli = kzalloc_obj(*eli);
4001 	if (!eli)
4002 		return -ENOMEM;
4003 
4004 	INIT_LIST_HEAD(&eli->li_request_list);
4005 	mutex_init(&eli->li_list_mtx);
4006 
4007 	eli->li_state |= EXT4_LAZYINIT_QUIT;
4008 
4009 	ext4_li_info = eli;
4010 
4011 	return 0;
4012 }
4013 
4014 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
4015 					    ext4_group_t start)
4016 {
4017 	struct ext4_li_request *elr;
4018 
4019 	elr = kzalloc_obj(*elr);
4020 	if (!elr)
4021 		return NULL;
4022 
4023 	elr->lr_super = sb;
4024 	elr->lr_first_not_zeroed = start;
4025 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
4026 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
4027 		elr->lr_next_group = start;
4028 	} else {
4029 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
4030 	}
4031 
4032 	/*
4033 	 * Randomize first schedule time of the request to
4034 	 * spread the inode table initialization requests
4035 	 * better.
4036 	 */
4037 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
4038 	return elr;
4039 }
4040 
4041 int ext4_register_li_request(struct super_block *sb,
4042 			     ext4_group_t first_not_zeroed)
4043 {
4044 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4045 	struct ext4_li_request *elr = NULL;
4046 	ext4_group_t ngroups = sbi->s_groups_count;
4047 	int ret = 0;
4048 
4049 	mutex_lock(&ext4_li_mtx);
4050 	if (sbi->s_li_request != NULL) {
4051 		/*
4052 		 * Reset timeout so it can be computed again, because
4053 		 * s_li_wait_mult might have changed.
4054 		 */
4055 		sbi->s_li_request->lr_timeout = 0;
4056 		goto out;
4057 	}
4058 
4059 	if (ext4_emergency_state(sb) || sb_rdonly(sb) ||
4060 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4061 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4062 		goto out;
4063 
4064 	elr = ext4_li_request_new(sb, first_not_zeroed);
4065 	if (!elr) {
4066 		ret = -ENOMEM;
4067 		goto out;
4068 	}
4069 
4070 	if (NULL == ext4_li_info) {
4071 		ret = ext4_li_info_new();
4072 		if (ret)
4073 			goto out;
4074 	}
4075 
4076 	mutex_lock(&ext4_li_info->li_list_mtx);
4077 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4078 	mutex_unlock(&ext4_li_info->li_list_mtx);
4079 
4080 	sbi->s_li_request = elr;
4081 	/*
4082 	 * set elr to NULL here since it has been inserted to
4083 	 * the request_list and the removal and free of it is
4084 	 * handled by ext4_clear_request_list from now on.
4085 	 */
4086 	elr = NULL;
4087 
4088 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4089 		ret = ext4_run_lazyinit_thread();
4090 		if (ret)
4091 			goto out;
4092 	}
4093 out:
4094 	mutex_unlock(&ext4_li_mtx);
4095 	if (ret)
4096 		kfree(elr);
4097 	return ret;
4098 }
4099 
4100 /*
4101  * We do not need to lock anything since this is called on
4102  * module unload.
4103  */
4104 static void ext4_destroy_lazyinit_thread(void)
4105 {
4106 	/*
4107 	 * If thread exited earlier
4108 	 * there's nothing to be done.
4109 	 */
4110 	if (!ext4_li_info || !ext4_lazyinit_task)
4111 		return;
4112 
4113 	kthread_stop(ext4_lazyinit_task);
4114 }
4115 
4116 static int set_journal_csum_feature_set(struct super_block *sb)
4117 {
4118 	int ret = 1;
4119 	int compat, incompat;
4120 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4121 
4122 	if (ext4_has_feature_metadata_csum(sb)) {
4123 		/* journal checksum v3 */
4124 		compat = 0;
4125 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4126 	} else {
4127 		/* journal checksum v1 */
4128 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4129 		incompat = 0;
4130 	}
4131 
4132 	jbd2_journal_clear_features(sbi->s_journal,
4133 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4134 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4135 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4136 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4137 		ret = jbd2_journal_set_features(sbi->s_journal,
4138 				compat, 0,
4139 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4140 				incompat);
4141 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4142 		ret = jbd2_journal_set_features(sbi->s_journal,
4143 				compat, 0,
4144 				incompat);
4145 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4146 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4147 	} else {
4148 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4149 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4150 	}
4151 
4152 	return ret;
4153 }
4154 
4155 /*
4156  * Note: calculating the overhead so we can be compatible with
4157  * historical BSD practice is quite difficult in the face of
4158  * clusters/bigalloc.  This is because multiple metadata blocks from
4159  * different block group can end up in the same allocation cluster.
4160  * Calculating the exact overhead in the face of clustered allocation
4161  * requires either O(all block bitmaps) in memory or O(number of block
4162  * groups**2) in time.  We will still calculate the superblock for
4163  * older file systems --- and if we come across with a bigalloc file
4164  * system with zero in s_overhead_clusters the estimate will be close to
4165  * correct especially for very large cluster sizes --- but for newer
4166  * file systems, it's better to calculate this figure once at mkfs
4167  * time, and store it in the superblock.  If the superblock value is
4168  * present (even for non-bigalloc file systems), we will use it.
4169  */
4170 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4171 			  char *buf)
4172 {
4173 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4174 	struct ext4_group_desc	*gdp;
4175 	ext4_fsblk_t		first_block, last_block, b;
4176 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4177 	int			s, j, count = 0;
4178 	int			has_super = ext4_bg_has_super(sb, grp);
4179 
4180 	if (!ext4_has_feature_bigalloc(sb))
4181 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4182 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4183 			sbi->s_itb_per_group + 2);
4184 
4185 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4186 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4187 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4188 	for (i = 0; i < ngroups; i++) {
4189 		gdp = ext4_get_group_desc(sb, i, NULL);
4190 		b = ext4_block_bitmap(sb, gdp);
4191 		if (b >= first_block && b <= last_block) {
4192 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4193 			count++;
4194 		}
4195 		b = ext4_inode_bitmap(sb, gdp);
4196 		if (b >= first_block && b <= last_block) {
4197 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4198 			count++;
4199 		}
4200 		b = ext4_inode_table(sb, gdp);
4201 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4202 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4203 				int c = EXT4_B2C(sbi, b - first_block);
4204 				ext4_set_bit(c, buf);
4205 				count++;
4206 			}
4207 		if (i != grp)
4208 			continue;
4209 		s = 0;
4210 		if (ext4_bg_has_super(sb, grp)) {
4211 			ext4_set_bit(s++, buf);
4212 			count++;
4213 		}
4214 		j = ext4_bg_num_gdb(sb, grp);
4215 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4216 			ext4_error(sb, "Invalid number of block group "
4217 				   "descriptor blocks: %d", j);
4218 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4219 		}
4220 		count += j;
4221 		for (; j > 0; j--)
4222 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4223 	}
4224 	if (!count)
4225 		return 0;
4226 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4227 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4228 }
4229 
4230 /*
4231  * Compute the overhead and stash it in sbi->s_overhead
4232  */
4233 int ext4_calculate_overhead(struct super_block *sb)
4234 {
4235 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4236 	struct ext4_super_block *es = sbi->s_es;
4237 	struct inode *j_inode;
4238 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4239 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4240 	ext4_fsblk_t overhead = 0;
4241 	char *buf = kvmalloc(sb->s_blocksize, GFP_NOFS | __GFP_ZERO);
4242 
4243 	if (!buf)
4244 		return -ENOMEM;
4245 
4246 	/*
4247 	 * Compute the overhead (FS structures).  This is constant
4248 	 * for a given filesystem unless the number of block groups
4249 	 * changes so we cache the previous value until it does.
4250 	 */
4251 
4252 	/*
4253 	 * All of the blocks before first_data_block are overhead
4254 	 */
4255 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4256 
4257 	/*
4258 	 * Add the overhead found in each block group
4259 	 */
4260 	for (i = 0; i < ngroups; i++) {
4261 		int blks;
4262 
4263 		blks = count_overhead(sb, i, buf);
4264 		overhead += blks;
4265 		if (blks)
4266 			memset(buf, 0, sb->s_blocksize);
4267 		cond_resched();
4268 	}
4269 
4270 	/*
4271 	 * Add the internal journal blocks whether the journal has been
4272 	 * loaded or not
4273 	 */
4274 	if (sbi->s_journal && !sbi->s_journal_bdev_file)
4275 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4276 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4277 		/* j_inum for internal journal is non-zero */
4278 		j_inode = ext4_get_journal_inode(sb, j_inum);
4279 		if (!IS_ERR(j_inode)) {
4280 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4281 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4282 			iput(j_inode);
4283 		} else {
4284 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4285 		}
4286 	}
4287 	sbi->s_overhead = overhead;
4288 	smp_wmb();
4289 	kvfree(buf);
4290 	return 0;
4291 }
4292 
4293 static void ext4_set_resv_clusters(struct super_block *sb)
4294 {
4295 	ext4_fsblk_t resv_clusters;
4296 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4297 
4298 	/*
4299 	 * There's no need to reserve anything when we aren't using extents.
4300 	 * The space estimates are exact, there are no unwritten extents,
4301 	 * hole punching doesn't need new metadata... This is needed especially
4302 	 * to keep ext2/3 backward compatibility.
4303 	 */
4304 	if (!ext4_has_feature_extents(sb))
4305 		return;
4306 	/*
4307 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4308 	 * This should cover the situations where we can not afford to run
4309 	 * out of space like for example punch hole, or converting
4310 	 * unwritten extents in delalloc path. In most cases such
4311 	 * allocation would require 1, or 2 blocks, higher numbers are
4312 	 * very rare.
4313 	 */
4314 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4315 			 sbi->s_cluster_bits);
4316 
4317 	do_div(resv_clusters, 50);
4318 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4319 
4320 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4321 }
4322 
4323 static const char *ext4_quota_mode(struct super_block *sb)
4324 {
4325 #ifdef CONFIG_QUOTA
4326 	if (!ext4_quota_capable(sb))
4327 		return "none";
4328 
4329 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4330 		return "journalled";
4331 	else
4332 		return "writeback";
4333 #else
4334 	return "disabled";
4335 #endif
4336 }
4337 
4338 static void ext4_setup_csum_trigger(struct super_block *sb,
4339 				    enum ext4_journal_trigger_type type,
4340 				    void (*trigger)(
4341 					struct jbd2_buffer_trigger_type *type,
4342 					struct buffer_head *bh,
4343 					void *mapped_data,
4344 					size_t size))
4345 {
4346 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4347 
4348 	sbi->s_journal_triggers[type].sb = sb;
4349 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4350 }
4351 
4352 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4353 {
4354 	if (!sbi)
4355 		return;
4356 
4357 	kfree(sbi->s_blockgroup_lock);
4358 	fs_put_dax(sbi->s_daxdev, NULL);
4359 	kfree(sbi);
4360 }
4361 
4362 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4363 {
4364 	struct ext4_sb_info *sbi;
4365 
4366 	sbi = kzalloc_obj(*sbi);
4367 	if (!sbi)
4368 		return NULL;
4369 
4370 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4371 					   NULL, NULL);
4372 
4373 	sbi->s_blockgroup_lock =
4374 		kzalloc_obj(struct blockgroup_lock);
4375 
4376 	if (!sbi->s_blockgroup_lock)
4377 		goto err_out;
4378 
4379 	sb->s_fs_info = sbi;
4380 	sbi->s_sb = sb;
4381 	return sbi;
4382 err_out:
4383 	fs_put_dax(sbi->s_daxdev, NULL);
4384 	kfree(sbi);
4385 	return NULL;
4386 }
4387 
4388 static void ext4_set_def_opts(struct super_block *sb,
4389 			      struct ext4_super_block *es)
4390 {
4391 	unsigned long def_mount_opts;
4392 
4393 	/* Set defaults before we parse the mount options */
4394 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4395 	set_opt(sb, INIT_INODE_TABLE);
4396 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4397 		set_opt(sb, DEBUG);
4398 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4399 		set_opt(sb, GRPID);
4400 	if (def_mount_opts & EXT4_DEFM_UID16)
4401 		set_opt(sb, NO_UID32);
4402 	/* xattr user namespace & acls are now defaulted on */
4403 	set_opt(sb, XATTR_USER);
4404 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4405 	set_opt(sb, POSIX_ACL);
4406 #endif
4407 	if (ext4_has_feature_fast_commit(sb))
4408 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4409 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4410 	if (ext4_has_feature_metadata_csum(sb))
4411 		set_opt(sb, JOURNAL_CHECKSUM);
4412 
4413 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4414 		set_opt(sb, JOURNAL_DATA);
4415 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4416 		set_opt(sb, ORDERED_DATA);
4417 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4418 		set_opt(sb, WRITEBACK_DATA);
4419 
4420 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4421 		set_opt(sb, ERRORS_PANIC);
4422 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4423 		set_opt(sb, ERRORS_CONT);
4424 	else
4425 		set_opt(sb, ERRORS_RO);
4426 	/* block_validity enabled by default; disable with noblock_validity */
4427 	set_opt(sb, BLOCK_VALIDITY);
4428 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4429 		set_opt(sb, DISCARD);
4430 
4431 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4432 		set_opt(sb, BARRIER);
4433 
4434 	/*
4435 	 * enable delayed allocation by default
4436 	 * Use -o nodelalloc to turn it off
4437 	 */
4438 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4439 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4440 		set_opt(sb, DELALLOC);
4441 
4442 	set_opt(sb, DIOREAD_NOLOCK);
4443 }
4444 
4445 static int ext4_handle_clustersize(struct super_block *sb)
4446 {
4447 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4448 	struct ext4_super_block *es = sbi->s_es;
4449 	int clustersize;
4450 
4451 	/* Handle clustersize */
4452 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4453 	if (ext4_has_feature_bigalloc(sb)) {
4454 		if (clustersize < sb->s_blocksize) {
4455 			ext4_msg(sb, KERN_ERR,
4456 				 "cluster size (%d) smaller than "
4457 				 "block size (%lu)", clustersize, sb->s_blocksize);
4458 			return -EINVAL;
4459 		}
4460 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4461 			le32_to_cpu(es->s_log_block_size);
4462 	} else {
4463 		if (clustersize != sb->s_blocksize) {
4464 			ext4_msg(sb, KERN_ERR,
4465 				 "fragment/cluster size (%d) != "
4466 				 "block size (%lu)", clustersize, sb->s_blocksize);
4467 			return -EINVAL;
4468 		}
4469 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4470 			ext4_msg(sb, KERN_ERR,
4471 				 "#blocks per group too big: %lu",
4472 				 sbi->s_blocks_per_group);
4473 			return -EINVAL;
4474 		}
4475 		sbi->s_cluster_bits = 0;
4476 	}
4477 	sbi->s_clusters_per_group = le32_to_cpu(es->s_clusters_per_group);
4478 	if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4479 		ext4_msg(sb, KERN_ERR, "#clusters per group too big: %lu",
4480 			 sbi->s_clusters_per_group);
4481 		return -EINVAL;
4482 	}
4483 	if (sbi->s_blocks_per_group !=
4484 	    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4485 		ext4_msg(sb, KERN_ERR,
4486 			 "blocks per group (%lu) and clusters per group (%lu) inconsistent",
4487 			 sbi->s_blocks_per_group, sbi->s_clusters_per_group);
4488 		return -EINVAL;
4489 	}
4490 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4491 
4492 	/* Do we have standard group size of clustersize * 8 blocks ? */
4493 	if (sbi->s_blocks_per_group == clustersize << 3)
4494 		set_opt2(sb, STD_GROUP_SIZE);
4495 
4496 	return 0;
4497 }
4498 
4499 /*
4500  * ext4_atomic_write_init: Initializes filesystem min & max atomic write units.
4501  * With non-bigalloc filesystem awu will be based upon filesystem blocksize
4502  * & bdev awu units.
4503  * With bigalloc it will be based upon bigalloc cluster size & bdev awu units.
4504  * @sb: super block
4505  */
4506 static void ext4_atomic_write_init(struct super_block *sb)
4507 {
4508 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4509 	struct block_device *bdev = sb->s_bdev;
4510 	unsigned int clustersize = EXT4_CLUSTER_SIZE(sb);
4511 
4512 	if (!bdev_can_atomic_write(bdev))
4513 		return;
4514 
4515 	if (!ext4_has_feature_extents(sb))
4516 		return;
4517 
4518 	sbi->s_awu_min = max(sb->s_blocksize,
4519 			      bdev_atomic_write_unit_min_bytes(bdev));
4520 	sbi->s_awu_max = min(clustersize,
4521 			      bdev_atomic_write_unit_max_bytes(bdev));
4522 	if (sbi->s_awu_min && sbi->s_awu_max &&
4523 	    sbi->s_awu_min <= sbi->s_awu_max) {
4524 		ext4_msg(sb, KERN_NOTICE, "Supports (experimental) DIO atomic writes awu_min: %u, awu_max: %u",
4525 			 sbi->s_awu_min, sbi->s_awu_max);
4526 	} else {
4527 		sbi->s_awu_min = 0;
4528 		sbi->s_awu_max = 0;
4529 	}
4530 }
4531 
4532 static void ext4_fast_commit_init(struct super_block *sb)
4533 {
4534 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4535 
4536 	/* Initialize fast commit stuff */
4537 	atomic_set(&sbi->s_fc_subtid, 0);
4538 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4539 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4540 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4541 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4542 	sbi->s_fc_bytes = 0;
4543 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4544 	sbi->s_fc_ineligible_tid = 0;
4545 	mutex_init(&sbi->s_fc_lock);
4546 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4547 	memset(&sbi->s_fc_snap_stats, 0, sizeof(sbi->s_fc_snap_stats));
4548 	sbi->s_fc_replay_state.fc_regions = NULL;
4549 	sbi->s_fc_replay_state.fc_regions_size = 0;
4550 	sbi->s_fc_replay_state.fc_regions_used = 0;
4551 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4552 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4553 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4554 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4555 }
4556 
4557 static int ext4_inode_info_init(struct super_block *sb,
4558 				struct ext4_super_block *es)
4559 {
4560 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4561 
4562 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4563 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4564 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4565 	} else {
4566 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4567 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4568 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4569 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4570 				 sbi->s_first_ino);
4571 			return -EINVAL;
4572 		}
4573 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4574 		    (!is_power_of_2(sbi->s_inode_size)) ||
4575 		    (sbi->s_inode_size > sb->s_blocksize)) {
4576 			ext4_msg(sb, KERN_ERR,
4577 			       "unsupported inode size: %d",
4578 			       sbi->s_inode_size);
4579 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4580 			return -EINVAL;
4581 		}
4582 		/*
4583 		 * i_atime_extra is the last extra field available for
4584 		 * [acm]times in struct ext4_inode. Checking for that
4585 		 * field should suffice to ensure we have extra space
4586 		 * for all three.
4587 		 */
4588 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4589 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4590 			sb->s_time_gran = 1;
4591 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4592 		} else {
4593 			sb->s_time_gran = NSEC_PER_SEC;
4594 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4595 		}
4596 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4597 	}
4598 
4599 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4600 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4601 			EXT4_GOOD_OLD_INODE_SIZE;
4602 		if (ext4_has_feature_extra_isize(sb)) {
4603 			unsigned v, max = (sbi->s_inode_size -
4604 					   EXT4_GOOD_OLD_INODE_SIZE);
4605 
4606 			v = le16_to_cpu(es->s_want_extra_isize);
4607 			if (v > max) {
4608 				ext4_msg(sb, KERN_ERR,
4609 					 "bad s_want_extra_isize: %d", v);
4610 				return -EINVAL;
4611 			}
4612 			if (sbi->s_want_extra_isize < v)
4613 				sbi->s_want_extra_isize = v;
4614 
4615 			v = le16_to_cpu(es->s_min_extra_isize);
4616 			if (v > max) {
4617 				ext4_msg(sb, KERN_ERR,
4618 					 "bad s_min_extra_isize: %d", v);
4619 				return -EINVAL;
4620 			}
4621 			if (sbi->s_want_extra_isize < v)
4622 				sbi->s_want_extra_isize = v;
4623 		}
4624 	}
4625 
4626 	return 0;
4627 }
4628 
4629 #if IS_ENABLED(CONFIG_UNICODE)
4630 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4631 {
4632 	const struct ext4_sb_encodings *encoding_info;
4633 	struct unicode_map *encoding;
4634 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4635 
4636 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4637 		return 0;
4638 
4639 	encoding_info = ext4_sb_read_encoding(es);
4640 	if (!encoding_info) {
4641 		ext4_msg(sb, KERN_ERR,
4642 			"Encoding requested by superblock is unknown");
4643 		return -EINVAL;
4644 	}
4645 
4646 	encoding = utf8_load(encoding_info->version);
4647 	if (IS_ERR(encoding)) {
4648 		ext4_msg(sb, KERN_ERR,
4649 			"can't mount with superblock charset: %s-%u.%u.%u "
4650 			"not supported by the kernel. flags: 0x%x.",
4651 			encoding_info->name,
4652 			unicode_major(encoding_info->version),
4653 			unicode_minor(encoding_info->version),
4654 			unicode_rev(encoding_info->version),
4655 			encoding_flags);
4656 		return -EINVAL;
4657 	}
4658 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4659 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4660 		unicode_major(encoding_info->version),
4661 		unicode_minor(encoding_info->version),
4662 		unicode_rev(encoding_info->version),
4663 		encoding_flags);
4664 
4665 	sb->s_encoding = encoding;
4666 	sb->s_encoding_flags = encoding_flags;
4667 
4668 	return 0;
4669 }
4670 #else
4671 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4672 {
4673 	return 0;
4674 }
4675 #endif
4676 
4677 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4678 {
4679 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4680 
4681 	/* Warn if metadata_csum and gdt_csum are both set. */
4682 	if (ext4_has_feature_metadata_csum(sb) &&
4683 	    ext4_has_feature_gdt_csum(sb))
4684 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4685 			     "redundant flags; please run fsck.");
4686 
4687 	/* Check for a known checksum algorithm */
4688 	if (!ext4_verify_csum_type(sb, es)) {
4689 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4690 			 "unknown checksum algorithm.");
4691 		return -EINVAL;
4692 	}
4693 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4694 				ext4_orphan_file_block_trigger);
4695 
4696 	/* Check superblock checksum */
4697 	if (!ext4_superblock_csum_verify(sb, es)) {
4698 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4699 			 "invalid superblock checksum.  Run e2fsck?");
4700 		return -EFSBADCRC;
4701 	}
4702 
4703 	/* Precompute checksum seed for all metadata */
4704 	if (ext4_has_feature_csum_seed(sb))
4705 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4706 	else if (ext4_has_feature_metadata_csum(sb) ||
4707 		 ext4_has_feature_ea_inode(sb))
4708 		sbi->s_csum_seed = ext4_chksum(~0, es->s_uuid,
4709 					       sizeof(es->s_uuid));
4710 	return 0;
4711 }
4712 
4713 static int ext4_check_feature_compatibility(struct super_block *sb,
4714 					    struct ext4_super_block *es,
4715 					    int silent)
4716 {
4717 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4718 
4719 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4720 	    (ext4_has_compat_features(sb) ||
4721 	     ext4_has_ro_compat_features(sb) ||
4722 	     ext4_has_incompat_features(sb)))
4723 		ext4_msg(sb, KERN_WARNING,
4724 		       "feature flags set on rev 0 fs, "
4725 		       "running e2fsck is recommended");
4726 
4727 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4728 		set_opt2(sb, HURD_COMPAT);
4729 		if (ext4_has_feature_64bit(sb)) {
4730 			ext4_msg(sb, KERN_ERR,
4731 				 "The Hurd can't support 64-bit file systems");
4732 			return -EINVAL;
4733 		}
4734 
4735 		/*
4736 		 * ea_inode feature uses l_i_version field which is not
4737 		 * available in HURD_COMPAT mode.
4738 		 */
4739 		if (ext4_has_feature_ea_inode(sb)) {
4740 			ext4_msg(sb, KERN_ERR,
4741 				 "ea_inode feature is not supported for Hurd");
4742 			return -EINVAL;
4743 		}
4744 	}
4745 
4746 	if (IS_EXT2_SB(sb)) {
4747 		if (ext2_feature_set_ok(sb))
4748 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4749 				 "using the ext4 subsystem");
4750 		else {
4751 			/*
4752 			 * If we're probing be silent, if this looks like
4753 			 * it's actually an ext[34] filesystem.
4754 			 */
4755 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4756 				return -EINVAL;
4757 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4758 				 "to feature incompatibilities");
4759 			return -EINVAL;
4760 		}
4761 	}
4762 
4763 	if (IS_EXT3_SB(sb)) {
4764 		if (ext3_feature_set_ok(sb))
4765 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4766 				 "using the ext4 subsystem");
4767 		else {
4768 			/*
4769 			 * If we're probing be silent, if this looks like
4770 			 * it's actually an ext4 filesystem.
4771 			 */
4772 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4773 				return -EINVAL;
4774 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4775 				 "to feature incompatibilities");
4776 			return -EINVAL;
4777 		}
4778 	}
4779 
4780 	/*
4781 	 * Check feature flags regardless of the revision level, since we
4782 	 * previously didn't change the revision level when setting the flags,
4783 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4784 	 */
4785 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4786 		return -EINVAL;
4787 
4788 	if (sbi->s_daxdev) {
4789 		if (sb->s_blocksize == PAGE_SIZE)
4790 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4791 		else
4792 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4793 	}
4794 
4795 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4796 		if (ext4_has_feature_inline_data(sb)) {
4797 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4798 					" that may contain inline data");
4799 			return -EINVAL;
4800 		}
4801 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4802 			ext4_msg(sb, KERN_ERR,
4803 				"DAX unsupported by block device.");
4804 			return -EINVAL;
4805 		}
4806 	}
4807 
4808 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4809 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4810 			 es->s_encryption_level);
4811 		return -EINVAL;
4812 	}
4813 
4814 	return 0;
4815 }
4816 
4817 static int ext4_check_geometry(struct super_block *sb,
4818 			       struct ext4_super_block *es)
4819 {
4820 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4821 	__u64 blocks_count;
4822 	int err;
4823 
4824 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4825 		ext4_msg(sb, KERN_ERR,
4826 			 "Number of reserved GDT blocks insanely large: %d",
4827 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4828 		return -EINVAL;
4829 	}
4830 	/*
4831 	 * Test whether we have more sectors than will fit in sector_t,
4832 	 * and whether the max offset is addressable by the page cache.
4833 	 */
4834 	err = generic_check_addressable(sb->s_blocksize_bits,
4835 					ext4_blocks_count(es));
4836 	if (err) {
4837 		ext4_msg(sb, KERN_ERR, "filesystem"
4838 			 " too large to mount safely on this system");
4839 		return err;
4840 	}
4841 
4842 	/* check blocks count against device size */
4843 	blocks_count = sb_bdev_nr_blocks(sb);
4844 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4845 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4846 		       "exceeds size of device (%llu blocks)",
4847 		       ext4_blocks_count(es), blocks_count);
4848 		return -EINVAL;
4849 	}
4850 
4851 	/*
4852 	 * It makes no sense for the first data block to be beyond the end
4853 	 * of the filesystem.
4854 	 */
4855 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4856 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4857 			 "block %u is beyond end of filesystem (%llu)",
4858 			 le32_to_cpu(es->s_first_data_block),
4859 			 ext4_blocks_count(es));
4860 		return -EINVAL;
4861 	}
4862 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4863 	    (sbi->s_cluster_ratio == 1)) {
4864 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4865 			 "block is 0 with a 1k block and cluster size");
4866 		return -EINVAL;
4867 	}
4868 
4869 	blocks_count = (ext4_blocks_count(es) -
4870 			le32_to_cpu(es->s_first_data_block) +
4871 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4872 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4873 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4874 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4875 		       "(block count %llu, first data block %u, "
4876 		       "blocks per group %lu)", blocks_count,
4877 		       ext4_blocks_count(es),
4878 		       le32_to_cpu(es->s_first_data_block),
4879 		       EXT4_BLOCKS_PER_GROUP(sb));
4880 		return -EINVAL;
4881 	}
4882 	sbi->s_groups_count = blocks_count;
4883 	sbi->s_blockfile_groups = min(sbi->s_groups_count,
4884 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4885 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4886 	    le32_to_cpu(es->s_inodes_count)) {
4887 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4888 			 le32_to_cpu(es->s_inodes_count),
4889 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4890 		return -EINVAL;
4891 	}
4892 
4893 	return 0;
4894 }
4895 
4896 static int ext4_group_desc_init(struct super_block *sb,
4897 				struct ext4_super_block *es,
4898 				ext4_fsblk_t logical_sb_block,
4899 				ext4_group_t *first_not_zeroed)
4900 {
4901 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4902 	unsigned int db_count;
4903 	ext4_fsblk_t block;
4904 	int i;
4905 
4906 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4907 		   EXT4_DESC_PER_BLOCK(sb);
4908 	if (ext4_has_feature_meta_bg(sb)) {
4909 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4910 			ext4_msg(sb, KERN_WARNING,
4911 				 "first meta block group too large: %u "
4912 				 "(group descriptor block count %u)",
4913 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4914 			return -EINVAL;
4915 		}
4916 	}
4917 	rcu_assign_pointer(sbi->s_group_desc,
4918 			   kvmalloc_objs(struct buffer_head *, db_count));
4919 	if (sbi->s_group_desc == NULL) {
4920 		ext4_msg(sb, KERN_ERR, "not enough memory");
4921 		return -ENOMEM;
4922 	}
4923 
4924 	bgl_lock_init(sbi->s_blockgroup_lock);
4925 
4926 	/* Pre-read the descriptors into the buffer cache */
4927 	for (i = 0; i < db_count; i++) {
4928 		block = descriptor_loc(sb, logical_sb_block, i);
4929 		ext4_sb_breadahead_unmovable(sb, block);
4930 	}
4931 
4932 	for (i = 0; i < db_count; i++) {
4933 		struct buffer_head *bh;
4934 
4935 		block = descriptor_loc(sb, logical_sb_block, i);
4936 		bh = ext4_sb_bread_unmovable(sb, block);
4937 		if (IS_ERR(bh)) {
4938 			ext4_msg(sb, KERN_ERR,
4939 			       "can't read group descriptor %d", i);
4940 			sbi->s_gdb_count = i;
4941 			return PTR_ERR(bh);
4942 		}
4943 		rcu_read_lock();
4944 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4945 		rcu_read_unlock();
4946 	}
4947 	sbi->s_gdb_count = db_count;
4948 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4949 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4950 		return -EFSCORRUPTED;
4951 	}
4952 
4953 	return 0;
4954 }
4955 
4956 static int ext4_load_and_init_journal(struct super_block *sb,
4957 				      struct ext4_super_block *es,
4958 				      struct ext4_fs_context *ctx)
4959 {
4960 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4961 	int err;
4962 
4963 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4964 	if (err)
4965 		return err;
4966 
4967 	if (ext4_has_feature_64bit(sb) &&
4968 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4969 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4970 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4971 		goto out;
4972 	}
4973 
4974 	if (!set_journal_csum_feature_set(sb)) {
4975 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4976 			 "feature set");
4977 		goto out;
4978 	}
4979 
4980 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4981 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4982 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4983 		ext4_msg(sb, KERN_ERR,
4984 			"Failed to set fast commit journal feature");
4985 		goto out;
4986 	}
4987 
4988 	/* We have now updated the journal if required, so we can
4989 	 * validate the data journaling mode. */
4990 	switch (test_opt(sb, DATA_FLAGS)) {
4991 	case 0:
4992 		/* No mode set, assume a default based on the journal
4993 		 * capabilities: ORDERED_DATA if the journal can
4994 		 * cope, else JOURNAL_DATA
4995 		 */
4996 		if (jbd2_journal_check_available_features
4997 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4998 			set_opt(sb, ORDERED_DATA);
4999 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
5000 		} else {
5001 			set_opt(sb, JOURNAL_DATA);
5002 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
5003 		}
5004 		break;
5005 
5006 	case EXT4_MOUNT_ORDERED_DATA:
5007 	case EXT4_MOUNT_WRITEBACK_DATA:
5008 		if (!jbd2_journal_check_available_features
5009 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5010 			ext4_msg(sb, KERN_ERR, "Journal does not support "
5011 			       "requested data journaling mode");
5012 			goto out;
5013 		}
5014 		break;
5015 	default:
5016 		break;
5017 	}
5018 
5019 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5020 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5021 		ext4_msg(sb, KERN_ERR, "can't mount with "
5022 			"journal_async_commit in data=ordered mode");
5023 		goto out;
5024 	}
5025 
5026 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5027 
5028 	sbi->s_journal->j_submit_inode_data_buffers =
5029 		ext4_journal_submit_inode_data_buffers;
5030 	sbi->s_journal->j_finish_inode_data_buffers =
5031 		ext4_journal_finish_inode_data_buffers;
5032 
5033 	return 0;
5034 
5035 out:
5036 	ext4_journal_destroy(sbi, sbi->s_journal);
5037 	return -EINVAL;
5038 }
5039 
5040 static int ext4_check_journal_data_mode(struct super_block *sb)
5041 {
5042 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5043 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
5044 			    "data=journal disables delayed allocation, "
5045 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
5046 		/* can't mount with both data=journal and dioread_nolock. */
5047 		clear_opt(sb, DIOREAD_NOLOCK);
5048 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5049 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5050 			ext4_msg(sb, KERN_ERR, "can't mount with "
5051 				 "both data=journal and delalloc");
5052 			return -EINVAL;
5053 		}
5054 		if (test_opt(sb, DAX_ALWAYS)) {
5055 			ext4_msg(sb, KERN_ERR, "can't mount with "
5056 				 "both data=journal and dax");
5057 			return -EINVAL;
5058 		}
5059 		if (ext4_has_feature_encrypt(sb)) {
5060 			ext4_msg(sb, KERN_WARNING,
5061 				 "encrypted files will use data=ordered "
5062 				 "instead of data journaling mode");
5063 		}
5064 		if (test_opt(sb, DELALLOC))
5065 			clear_opt(sb, DELALLOC);
5066 	} else {
5067 		sb->s_iflags |= SB_I_CGROUPWB;
5068 	}
5069 
5070 	return 0;
5071 }
5072 
5073 static const char *ext4_has_journal_option(struct super_block *sb)
5074 {
5075 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5076 
5077 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
5078 		return "journal_async_commit";
5079 	if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM))
5080 		return "journal_checksum";
5081 	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
5082 		return "commit=";
5083 	if (EXT4_MOUNT_DATA_FLAGS &
5084 	    (sbi->s_mount_opt ^ sbi->s_def_mount_opt))
5085 		return "data=";
5086 	if (test_opt(sb, DATA_ERR_ABORT))
5087 		return "data_err=abort";
5088 	return NULL;
5089 }
5090 
5091 /*
5092  * Limit the maximum folio order to 2048 blocks to prevent overestimation
5093  * of reserve handle credits during the folio writeback in environments
5094  * where the PAGE_SIZE exceeds 4KB.
5095  */
5096 #define EXT4_MAX_PAGECACHE_ORDER(sb)		\
5097 		umin(MAX_PAGECACHE_ORDER, (11 + (sb)->s_blocksize_bits - PAGE_SHIFT))
5098 static void ext4_set_max_mapping_order(struct super_block *sb)
5099 {
5100 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5101 
5102 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5103 		sbi->s_max_folio_order = sbi->s_min_folio_order;
5104 	else
5105 		sbi->s_max_folio_order = EXT4_MAX_PAGECACHE_ORDER(sb);
5106 }
5107 
5108 static int ext4_check_large_folio(struct super_block *sb)
5109 {
5110 	const char *err_str = NULL;
5111 
5112 	if (ext4_has_feature_encrypt(sb))
5113 		err_str = "encrypt";
5114 
5115 	if (!err_str) {
5116 		ext4_set_max_mapping_order(sb);
5117 	} else if (sb->s_blocksize > PAGE_SIZE) {
5118 		ext4_msg(sb, KERN_ERR, "bs(%lu) > ps(%lu) unsupported for %s",
5119 			 sb->s_blocksize, PAGE_SIZE, err_str);
5120 		return -EINVAL;
5121 	}
5122 
5123 	return 0;
5124 }
5125 
5126 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5127 			   int silent)
5128 {
5129 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5130 	struct ext4_super_block *es;
5131 	ext4_fsblk_t logical_sb_block;
5132 	unsigned long offset = 0;
5133 	struct buffer_head *bh;
5134 	int ret = -EINVAL;
5135 	int blocksize;
5136 
5137 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5138 	if (!blocksize) {
5139 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5140 		return -EINVAL;
5141 	}
5142 
5143 	/*
5144 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5145 	 * block sizes.  We need to calculate the offset from buffer start.
5146 	 */
5147 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5148 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5149 		offset = do_div(logical_sb_block, blocksize);
5150 	} else {
5151 		logical_sb_block = sbi->s_sb_block;
5152 	}
5153 
5154 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5155 	if (IS_ERR(bh)) {
5156 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5157 		return PTR_ERR(bh);
5158 	}
5159 	/*
5160 	 * Note: s_es must be initialized as soon as possible because
5161 	 *       some ext4 macro-instructions depend on its value
5162 	 */
5163 	es = (struct ext4_super_block *) (bh->b_data + offset);
5164 	sbi->s_es = es;
5165 	sb->s_magic = le16_to_cpu(es->s_magic);
5166 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5167 		if (!silent)
5168 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5169 		goto out;
5170 	}
5171 
5172 	if (le32_to_cpu(es->s_log_block_size) >
5173 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5174 		ext4_msg(sb, KERN_ERR,
5175 			 "Invalid log block size: %u",
5176 			 le32_to_cpu(es->s_log_block_size));
5177 		goto out;
5178 	}
5179 	if (le32_to_cpu(es->s_log_cluster_size) >
5180 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5181 		ext4_msg(sb, KERN_ERR,
5182 			 "Invalid log cluster size: %u",
5183 			 le32_to_cpu(es->s_log_cluster_size));
5184 		goto out;
5185 	}
5186 
5187 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5188 
5189 	/*
5190 	 * If the default block size is not the same as the real block size,
5191 	 * we need to reload it.
5192 	 */
5193 	if (sb->s_blocksize == blocksize)
5194 		goto success;
5195 
5196 	/*
5197 	 * bh must be released before kill_bdev(), otherwise
5198 	 * it won't be freed and its page also. kill_bdev()
5199 	 * is called by sb_set_blocksize().
5200 	 */
5201 	brelse(bh);
5202 	/* Validate the filesystem blocksize */
5203 	if (!sb_set_blocksize(sb, blocksize)) {
5204 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5205 				blocksize);
5206 		bh = NULL;
5207 		goto out;
5208 	}
5209 
5210 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5211 	offset = do_div(logical_sb_block, blocksize);
5212 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5213 	if (IS_ERR(bh)) {
5214 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5215 		ret = PTR_ERR(bh);
5216 		bh = NULL;
5217 		goto out;
5218 	}
5219 	es = (struct ext4_super_block *)(bh->b_data + offset);
5220 	sbi->s_es = es;
5221 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5222 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5223 		goto out;
5224 	}
5225 
5226 success:
5227 	sbi->s_min_folio_order = get_order(blocksize);
5228 	*lsb = logical_sb_block;
5229 	sbi->s_sbh = bh;
5230 	return 0;
5231 out:
5232 	brelse(bh);
5233 	return ret;
5234 }
5235 
5236 static int ext4_hash_info_init(struct super_block *sb)
5237 {
5238 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5239 	struct ext4_super_block *es = sbi->s_es;
5240 	unsigned int i;
5241 
5242 	sbi->s_def_hash_version = es->s_def_hash_version;
5243 
5244 	if (sbi->s_def_hash_version > DX_HASH_LAST) {
5245 		ext4_msg(sb, KERN_ERR,
5246 			 "Invalid default hash set in the superblock");
5247 		return -EINVAL;
5248 	} else if (sbi->s_def_hash_version == DX_HASH_SIPHASH) {
5249 		ext4_msg(sb, KERN_ERR,
5250 			 "SIPHASH is not a valid default hash value");
5251 		return -EINVAL;
5252 	}
5253 
5254 	for (i = 0; i < 4; i++)
5255 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5256 
5257 	if (ext4_has_feature_dir_index(sb)) {
5258 		i = le32_to_cpu(es->s_flags);
5259 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5260 			sbi->s_hash_unsigned = 3;
5261 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5262 #ifdef __CHAR_UNSIGNED__
5263 			if (!sb_rdonly(sb))
5264 				es->s_flags |=
5265 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5266 			sbi->s_hash_unsigned = 3;
5267 #else
5268 			if (!sb_rdonly(sb))
5269 				es->s_flags |=
5270 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5271 #endif
5272 		}
5273 	}
5274 	return 0;
5275 }
5276 
5277 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5278 {
5279 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5280 	struct ext4_super_block *es = sbi->s_es;
5281 	int has_huge_files;
5282 
5283 	has_huge_files = ext4_has_feature_huge_file(sb);
5284 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5285 						      has_huge_files);
5286 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5287 
5288 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5289 	if (ext4_has_feature_64bit(sb)) {
5290 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5291 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5292 		    !is_power_of_2(sbi->s_desc_size)) {
5293 			ext4_msg(sb, KERN_ERR,
5294 			       "unsupported descriptor size %lu",
5295 			       sbi->s_desc_size);
5296 			return -EINVAL;
5297 		}
5298 	} else
5299 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5300 
5301 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5302 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5303 
5304 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5305 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5306 		if (!silent)
5307 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5308 		return -EINVAL;
5309 	}
5310 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5311 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5312 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5313 			 sbi->s_inodes_per_group);
5314 		return -EINVAL;
5315 	}
5316 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5317 					sbi->s_inodes_per_block;
5318 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5319 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5320 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5321 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5322 
5323 	return 0;
5324 }
5325 
5326 /*
5327  * It's hard to get stripe aligned blocks if stripe is not aligned with
5328  * cluster, just disable stripe and alert user to simplify code and avoid
5329  * stripe aligned allocation which will rarely succeed.
5330  */
5331 static bool ext4_is_stripe_incompatible(struct super_block *sb, unsigned long stripe)
5332 {
5333 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5334 	return (stripe > 0 && sbi->s_cluster_ratio > 1 &&
5335 		stripe % sbi->s_cluster_ratio != 0);
5336 }
5337 
5338 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5339 {
5340 	struct ext4_super_block *es = NULL;
5341 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5342 	ext4_fsblk_t logical_sb_block;
5343 	struct inode *root;
5344 	int needs_recovery;
5345 	int err;
5346 	ext4_group_t first_not_zeroed;
5347 	struct ext4_fs_context *ctx = fc->fs_private;
5348 	int silent = fc->sb_flags & SB_SILENT;
5349 
5350 	/* Set defaults for the variables that will be set during parsing */
5351 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5352 		ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
5353 
5354 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5355 	sbi->s_sectors_written_start =
5356 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5357 
5358 	err = ext4_load_super(sb, &logical_sb_block, silent);
5359 	if (err)
5360 		goto out_fail;
5361 
5362 	es = sbi->s_es;
5363 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5364 
5365 	err = ext4_init_metadata_csum(sb, es);
5366 	if (err)
5367 		goto failed_mount;
5368 
5369 	ext4_set_def_opts(sb, es);
5370 
5371 	sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
5372 	sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
5373 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5374 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5375 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5376 	sbi->s_sb_update_kb = EXT4_DEF_SB_UPDATE_INTERVAL_KB;
5377 	sbi->s_sb_update_sec = EXT4_DEF_SB_UPDATE_INTERVAL_SEC;
5378 
5379 	/*
5380 	 * set default s_li_wait_mult for lazyinit, for the case there is
5381 	 * no mount option specified.
5382 	 */
5383 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5384 
5385 	err = ext4_inode_info_init(sb, es);
5386 	if (err)
5387 		goto failed_mount;
5388 
5389 	err = parse_apply_sb_mount_options(sb, ctx);
5390 	if (err < 0)
5391 		goto failed_mount;
5392 
5393 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5394 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5395 
5396 	err = ext4_check_opt_consistency(fc, sb);
5397 	if (err < 0)
5398 		goto failed_mount;
5399 
5400 	ext4_apply_options(fc, sb);
5401 
5402 	err = ext4_check_large_folio(sb);
5403 	if (err < 0)
5404 		goto failed_mount;
5405 
5406 	err = ext4_encoding_init(sb, es);
5407 	if (err)
5408 		goto failed_mount;
5409 
5410 	err = ext4_check_journal_data_mode(sb);
5411 	if (err)
5412 		goto failed_mount;
5413 
5414 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5415 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5416 
5417 	/* HSM events are allowed by default. */
5418 	sb->s_iflags |= SB_I_ALLOW_HSM;
5419 
5420 	err = ext4_check_feature_compatibility(sb, es, silent);
5421 	if (err)
5422 		goto failed_mount;
5423 
5424 	err = ext4_block_group_meta_init(sb, silent);
5425 	if (err)
5426 		goto failed_mount;
5427 
5428 	err = ext4_hash_info_init(sb);
5429 	if (err)
5430 		goto failed_mount;
5431 
5432 	err = ext4_handle_clustersize(sb);
5433 	if (err)
5434 		goto failed_mount;
5435 
5436 	err = ext4_check_geometry(sb, es);
5437 	if (err)
5438 		goto failed_mount;
5439 
5440 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5441 	spin_lock_init(&sbi->s_error_lock);
5442 	mutex_init(&sbi->s_error_notify_mutex);
5443 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5444 
5445 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5446 	if (err)
5447 		goto failed_mount3;
5448 
5449 	err = ext4_es_register_shrinker(sbi);
5450 	if (err)
5451 		goto failed_mount3;
5452 
5453 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5454 	if (ext4_is_stripe_incompatible(sb, sbi->s_stripe)) {
5455 		ext4_msg(sb, KERN_WARNING,
5456 			 "stripe (%lu) is not aligned with cluster size (%u), "
5457 			 "stripe is disabled",
5458 			 sbi->s_stripe, sbi->s_cluster_ratio);
5459 		sbi->s_stripe = 0;
5460 	}
5461 	sbi->s_extent_max_zeroout_kb = 32;
5462 
5463 	/*
5464 	 * set up enough so that it can read an inode
5465 	 */
5466 	sb->s_op = &ext4_sops;
5467 	sb->s_export_op = &ext4_export_ops;
5468 	sb->s_xattr = ext4_xattr_handlers;
5469 #ifdef CONFIG_FS_ENCRYPTION
5470 	sb->s_cop = &ext4_cryptops;
5471 #endif
5472 #ifdef CONFIG_FS_VERITY
5473 	sb->s_vop = &ext4_verityops;
5474 #endif
5475 #ifdef CONFIG_QUOTA
5476 	sb->dq_op = &ext4_quota_operations;
5477 	if (ext4_has_feature_quota(sb))
5478 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5479 	else
5480 		sb->s_qcop = &ext4_qctl_operations;
5481 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5482 #endif
5483 	super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));
5484 	super_set_sysfs_name_bdev(sb);
5485 
5486 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5487 	mutex_init(&sbi->s_orphan_lock);
5488 
5489 	spin_lock_init(&sbi->s_bdev_wb_lock);
5490 
5491 	ext4_atomic_write_init(sb);
5492 	ext4_fast_commit_init(sb);
5493 
5494 	sb->s_root = NULL;
5495 
5496 	needs_recovery = (es->s_last_orphan != 0 ||
5497 			  ext4_has_feature_orphan_present(sb) ||
5498 			  ext4_has_feature_journal_needs_recovery(sb));
5499 
5500 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5501 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5502 		if (err)
5503 			goto failed_mount3a;
5504 	}
5505 
5506 	err = -EINVAL;
5507 	/*
5508 	 * The first inode we look at is the journal inode.  Don't try
5509 	 * root first: it may be modified in the journal!
5510 	 */
5511 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5512 		err = ext4_load_and_init_journal(sb, es, ctx);
5513 		if (err)
5514 			goto failed_mount3a;
5515 		if (bdev_read_only(sb->s_bdev))
5516 		    needs_recovery = 0;
5517 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5518 		   ext4_has_feature_journal_needs_recovery(sb)) {
5519 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5520 		       "suppressed and not mounted read-only");
5521 		goto failed_mount3a;
5522 	} else {
5523 		const char *journal_option;
5524 
5525 		/* Nojournal mode, all journal mount options are illegal */
5526 		journal_option = ext4_has_journal_option(sb);
5527 		if (journal_option != NULL) {
5528 			ext4_msg(sb, KERN_ERR,
5529 				 "can't mount with %s, fs mounted w/o journal",
5530 				 journal_option);
5531 			goto failed_mount3a;
5532 		}
5533 
5534 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5535 		clear_opt(sb, JOURNAL_CHECKSUM);
5536 		clear_opt(sb, DATA_FLAGS);
5537 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5538 		sbi->s_journal = NULL;
5539 		needs_recovery = 0;
5540 	}
5541 
5542 	if (!test_opt(sb, NO_MBCACHE)) {
5543 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5544 		if (!sbi->s_ea_block_cache) {
5545 			ext4_msg(sb, KERN_ERR,
5546 				 "Failed to create ea_block_cache");
5547 			err = -EINVAL;
5548 			goto failed_mount_wq;
5549 		}
5550 
5551 		if (ext4_has_feature_ea_inode(sb)) {
5552 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5553 			if (!sbi->s_ea_inode_cache) {
5554 				ext4_msg(sb, KERN_ERR,
5555 					 "Failed to create ea_inode_cache");
5556 				err = -EINVAL;
5557 				goto failed_mount_wq;
5558 			}
5559 		}
5560 	}
5561 
5562 	/*
5563 	 * Get the # of file system overhead blocks from the
5564 	 * superblock if present.
5565 	 */
5566 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5567 	/* ignore the precalculated value if it is ridiculous */
5568 	if (sbi->s_overhead > ext4_blocks_count(es))
5569 		sbi->s_overhead = 0;
5570 	/*
5571 	 * If the bigalloc feature is not enabled recalculating the
5572 	 * overhead doesn't take long, so we might as well just redo
5573 	 * it to make sure we are using the correct value.
5574 	 */
5575 	if (!ext4_has_feature_bigalloc(sb))
5576 		sbi->s_overhead = 0;
5577 	if (sbi->s_overhead == 0) {
5578 		err = ext4_calculate_overhead(sb);
5579 		if (err)
5580 			goto failed_mount_wq;
5581 	}
5582 
5583 	/*
5584 	 * The maximum number of concurrent works can be high and
5585 	 * concurrency isn't really necessary.  Limit it to 1.
5586 	 */
5587 	EXT4_SB(sb)->rsv_conversion_wq =
5588 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5589 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5590 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5591 		err = -ENOMEM;
5592 		goto failed_mount4;
5593 	}
5594 
5595 	/*
5596 	 * The jbd2_journal_load will have done any necessary log recovery,
5597 	 * so we can safely mount the rest of the filesystem now.
5598 	 */
5599 
5600 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5601 	if (IS_ERR(root)) {
5602 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5603 		err = PTR_ERR(root);
5604 		root = NULL;
5605 		goto failed_mount4;
5606 	}
5607 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5608 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5609 		iput(root);
5610 		err = -EFSCORRUPTED;
5611 		goto failed_mount4;
5612 	}
5613 
5614 	generic_set_sb_d_ops(sb);
5615 	sb->s_root = d_make_root(root);
5616 	if (!sb->s_root) {
5617 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5618 		err = -ENOMEM;
5619 		goto failed_mount4;
5620 	}
5621 
5622 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5623 	if (err == -EROFS) {
5624 		sb->s_flags |= SB_RDONLY;
5625 	} else if (err)
5626 		goto failed_mount4a;
5627 
5628 	ext4_set_resv_clusters(sb);
5629 
5630 	if (test_opt(sb, BLOCK_VALIDITY)) {
5631 		err = ext4_setup_system_zone(sb);
5632 		if (err) {
5633 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5634 				 "zone (%d)", err);
5635 			goto failed_mount4a;
5636 		}
5637 	}
5638 	ext4_fc_replay_cleanup(sb);
5639 
5640 	ext4_ext_init(sb);
5641 
5642 	/*
5643 	 * Enable optimize_scan if number of groups is > threshold. This can be
5644 	 * turned off by passing "mb_optimize_scan=0". This can also be
5645 	 * turned on forcefully by passing "mb_optimize_scan=1".
5646 	 */
5647 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5648 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5649 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5650 		else
5651 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5652 	}
5653 
5654 	err = ext4_percpu_param_init(sbi);
5655 	if (err)
5656 		goto failed_mount5;
5657 
5658 	err = ext4_mb_init(sb);
5659 	if (err) {
5660 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5661 			 err);
5662 		goto failed_mount5;
5663 	}
5664 
5665 	/*
5666 	 * We can only set up the journal commit callback once
5667 	 * mballoc is initialized
5668 	 */
5669 	if (sbi->s_journal)
5670 		sbi->s_journal->j_commit_callback =
5671 			ext4_journal_commit_callback;
5672 
5673 	if (ext4_has_feature_flex_bg(sb))
5674 		if (!ext4_fill_flex_info(sb)) {
5675 			ext4_msg(sb, KERN_ERR,
5676 			       "unable to initialize "
5677 			       "flex_bg meta info!");
5678 			err = -ENOMEM;
5679 			goto failed_mount6;
5680 		}
5681 
5682 	err = ext4_register_li_request(sb, first_not_zeroed);
5683 	if (err)
5684 		goto failed_mount6;
5685 
5686 	err = ext4_init_orphan_info(sb);
5687 	if (err)
5688 		goto failed_mount7;
5689 #ifdef CONFIG_QUOTA
5690 	/* Enable quota usage during mount. */
5691 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5692 		err = ext4_enable_quotas(sb);
5693 		if (err)
5694 			goto failed_mount8;
5695 	}
5696 #endif  /* CONFIG_QUOTA */
5697 
5698 	/*
5699 	 * Save the original bdev mapping's wb_err value which could be
5700 	 * used to detect the metadata async write error.
5701 	 */
5702 	errseq_check_and_advance(&sb->s_bdev->bd_mapping->wb_err,
5703 				 &sbi->s_bdev_wb_err);
5704 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5705 	ext4_orphan_cleanup(sb, es);
5706 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5707 	/*
5708 	 * Update the checksum after updating free space/inode counters and
5709 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5710 	 * checksum in the buffer cache until it is written out and
5711 	 * e2fsprogs programs trying to open a file system immediately
5712 	 * after it is mounted can fail.
5713 	 */
5714 	ext4_superblock_csum_set(sb);
5715 	if (needs_recovery) {
5716 		ext4_msg(sb, KERN_INFO, "recovery complete");
5717 		err = ext4_mark_recovery_complete(sb, es);
5718 		if (err)
5719 			goto failed_mount9;
5720 	}
5721 
5722 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev)) {
5723 		ext4_msg(sb, KERN_WARNING,
5724 			 "mounting with \"discard\" option, but the device does not support discard");
5725 		clear_opt(sb, DISCARD);
5726 	}
5727 
5728 	if (es->s_error_count) {
5729 		sbi->s_err_report_sec = 5*60;	/* first time  5 minutes */
5730 		mod_timer(&sbi->s_err_report,
5731 				  jiffies + secs_to_jiffies(sbi->s_err_report_sec));
5732 	}
5733 	sbi->s_err_report_sec = 24*60*60; /* Once a day */
5734 
5735 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5736 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5737 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5738 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5739 	atomic_set(&sbi->s_warning_count, 0);
5740 	atomic_set(&sbi->s_msg_count, 0);
5741 
5742 	/* Register sysfs after all initializations are complete. */
5743 	err = ext4_register_sysfs(sb);
5744 	if (err)
5745 		goto failed_mount9;
5746 
5747 	return 0;
5748 
5749 failed_mount9:
5750 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5751 failed_mount8: __maybe_unused
5752 	ext4_release_orphan_info(sb);
5753 failed_mount7:
5754 	ext4_unregister_li_request(sb);
5755 failed_mount6:
5756 	ext4_mb_release(sb);
5757 	ext4_flex_groups_free(sbi);
5758 failed_mount5:
5759 	ext4_percpu_param_destroy(sbi);
5760 	ext4_ext_release(sb);
5761 	ext4_release_system_zone(sb);
5762 failed_mount4a:
5763 	dput(sb->s_root);
5764 	sb->s_root = NULL;
5765 failed_mount4:
5766 	ext4_msg(sb, KERN_ERR, "mount failed");
5767 	if (EXT4_SB(sb)->rsv_conversion_wq)
5768 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5769 failed_mount_wq:
5770 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5771 	sbi->s_ea_inode_cache = NULL;
5772 
5773 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5774 	sbi->s_ea_block_cache = NULL;
5775 
5776 	if (sbi->s_journal) {
5777 		ext4_journal_destroy(sbi, sbi->s_journal);
5778 	}
5779 failed_mount3a:
5780 	ext4_es_unregister_shrinker(sbi);
5781 failed_mount3:
5782 	/* flush s_sb_upd_work before sbi destroy */
5783 	flush_work(&sbi->s_sb_upd_work);
5784 	ext4_stop_mmpd(sbi);
5785 	timer_delete_sync(&sbi->s_err_report);
5786 	ext4_group_desc_free(sbi);
5787 failed_mount:
5788 #if IS_ENABLED(CONFIG_UNICODE)
5789 	utf8_unload(sb->s_encoding);
5790 #endif
5791 
5792 #ifdef CONFIG_QUOTA
5793 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5794 		kfree(get_qf_name(sb, sbi, i));
5795 #endif
5796 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5797 	brelse(sbi->s_sbh);
5798 	if (sbi->s_journal_bdev_file) {
5799 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
5800 		bdev_fput(sbi->s_journal_bdev_file);
5801 	}
5802 out_fail:
5803 	invalidate_bdev(sb->s_bdev);
5804 	sb->s_fs_info = NULL;
5805 	return err;
5806 }
5807 
5808 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5809 {
5810 	struct ext4_fs_context *ctx = fc->fs_private;
5811 	struct ext4_sb_info *sbi;
5812 	const char *descr;
5813 	int ret;
5814 
5815 	sbi = ext4_alloc_sbi(sb);
5816 	if (!sbi)
5817 		return -ENOMEM;
5818 
5819 	fc->s_fs_info = sbi;
5820 
5821 	/* Cleanup superblock name */
5822 	strreplace(sb->s_id, '/', '!');
5823 
5824 	sbi->s_sb_block = 1;	/* Default super block location */
5825 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5826 		sbi->s_sb_block = ctx->s_sb_block;
5827 
5828 	ret = __ext4_fill_super(fc, sb);
5829 	if (ret < 0)
5830 		goto free_sbi;
5831 
5832 	if (sbi->s_journal) {
5833 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5834 			descr = " journalled data mode";
5835 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5836 			descr = " ordered data mode";
5837 		else
5838 			descr = " writeback data mode";
5839 	} else
5840 		descr = "out journal";
5841 
5842 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5843 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5844 			 "Quota mode: %s.", &sb->s_uuid,
5845 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5846 			 ext4_quota_mode(sb));
5847 
5848 	/* Update the s_overhead_clusters if necessary */
5849 	ext4_update_overhead(sb, false);
5850 	return 0;
5851 
5852 free_sbi:
5853 	ext4_free_sbi(sbi);
5854 	fc->s_fs_info = NULL;
5855 	return ret;
5856 }
5857 
5858 static int ext4_get_tree(struct fs_context *fc)
5859 {
5860 	return get_tree_bdev(fc, ext4_fill_super);
5861 }
5862 
5863 /*
5864  * Setup any per-fs journal parameters now.  We'll do this both on
5865  * initial mount, once the journal has been initialised but before we've
5866  * done any recovery; and again on any subsequent remount.
5867  */
5868 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5869 {
5870 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5871 
5872 	journal->j_commit_interval = sbi->s_commit_interval;
5873 	journal->j_min_batch_time = sbi->s_min_batch_time;
5874 	journal->j_max_batch_time = sbi->s_max_batch_time;
5875 	ext4_fc_init(sb, journal);
5876 
5877 	write_lock(&journal->j_state_lock);
5878 	if (test_opt(sb, BARRIER))
5879 		journal->j_flags |= JBD2_BARRIER;
5880 	else
5881 		journal->j_flags &= ~JBD2_BARRIER;
5882 	/*
5883 	 * Always enable journal cycle record option, letting the journal
5884 	 * records log transactions continuously between each mount.
5885 	 */
5886 	journal->j_flags |= JBD2_CYCLE_RECORD;
5887 	write_unlock(&journal->j_state_lock);
5888 }
5889 
5890 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5891 					     unsigned int journal_inum)
5892 {
5893 	struct inode *journal_inode;
5894 
5895 	/*
5896 	 * Test for the existence of a valid inode on disk.  Bad things
5897 	 * happen if we iget() an unused inode, as the subsequent iput()
5898 	 * will try to delete it.
5899 	 */
5900 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5901 	if (IS_ERR(journal_inode)) {
5902 		ext4_msg(sb, KERN_ERR, "no journal found");
5903 		return ERR_CAST(journal_inode);
5904 	}
5905 	if (!journal_inode->i_nlink) {
5906 		make_bad_inode(journal_inode);
5907 		iput(journal_inode);
5908 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5909 		return ERR_PTR(-EFSCORRUPTED);
5910 	}
5911 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5912 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5913 		iput(journal_inode);
5914 		return ERR_PTR(-EFSCORRUPTED);
5915 	}
5916 
5917 #ifdef CONFIG_LOCKDEP
5918 	lockdep_set_subclass(&EXT4_I(journal_inode)->i_data_sem,
5919 			     I_DATA_SEM_JOURNAL);
5920 #endif
5921 
5922 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5923 		  journal_inode, journal_inode->i_size);
5924 	return journal_inode;
5925 }
5926 
5927 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5928 {
5929 	struct ext4_map_blocks map;
5930 	int ret;
5931 
5932 	if (journal->j_inode == NULL)
5933 		return 0;
5934 
5935 	map.m_lblk = *block;
5936 	map.m_len = 1;
5937 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5938 	if (ret <= 0) {
5939 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5940 			 "journal bmap failed: block %llu ret %d\n",
5941 			 *block, ret);
5942 		jbd2_journal_abort(journal, ret ? ret : -EFSCORRUPTED);
5943 		return ret;
5944 	}
5945 	*block = map.m_pblk;
5946 	return 0;
5947 }
5948 
5949 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5950 					  unsigned int journal_inum)
5951 {
5952 	struct inode *journal_inode;
5953 	journal_t *journal;
5954 
5955 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5956 	if (IS_ERR(journal_inode))
5957 		return ERR_CAST(journal_inode);
5958 
5959 	journal = jbd2_journal_init_inode(journal_inode);
5960 	if (IS_ERR(journal)) {
5961 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5962 		iput(journal_inode);
5963 		return ERR_CAST(journal);
5964 	}
5965 	journal->j_private = sb;
5966 	journal->j_bmap = ext4_journal_bmap;
5967 	ext4_init_journal_params(sb, journal);
5968 	return journal;
5969 }
5970 
5971 static struct file *ext4_get_journal_blkdev(struct super_block *sb,
5972 					dev_t j_dev, ext4_fsblk_t *j_start,
5973 					ext4_fsblk_t *j_len)
5974 {
5975 	struct buffer_head *bh;
5976 	struct block_device *bdev;
5977 	struct file *bdev_file;
5978 	int hblock, blocksize;
5979 	ext4_fsblk_t sb_block;
5980 	unsigned long offset;
5981 	struct ext4_super_block *es;
5982 	int errno;
5983 
5984 	bdev_file = bdev_file_open_by_dev(j_dev,
5985 		BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
5986 		sb, &fs_holder_ops);
5987 	if (IS_ERR(bdev_file)) {
5988 		ext4_msg(sb, KERN_ERR,
5989 			 "failed to open journal device unknown-block(%u,%u) %pe",
5990 			 MAJOR(j_dev), MINOR(j_dev), bdev_file);
5991 		return bdev_file;
5992 	}
5993 
5994 	bdev = file_bdev(bdev_file);
5995 	blocksize = sb->s_blocksize;
5996 	hblock = bdev_logical_block_size(bdev);
5997 	if (blocksize < hblock) {
5998 		ext4_msg(sb, KERN_ERR,
5999 			"blocksize too small for journal device");
6000 		errno = -EINVAL;
6001 		goto out_bdev;
6002 	}
6003 
6004 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
6005 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
6006 	set_blocksize(bdev_file, blocksize);
6007 	bh = __bread(bdev, sb_block, blocksize);
6008 	if (!bh) {
6009 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
6010 		       "external journal");
6011 		errno = -EINVAL;
6012 		goto out_bdev;
6013 	}
6014 
6015 	es = (struct ext4_super_block *) (bh->b_data + offset);
6016 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
6017 	    !(le32_to_cpu(es->s_feature_incompat) &
6018 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
6019 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
6020 		errno = -EFSCORRUPTED;
6021 		goto out_bh;
6022 	}
6023 
6024 	if ((le32_to_cpu(es->s_feature_ro_compat) &
6025 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
6026 	    es->s_checksum != ext4_superblock_csum(es)) {
6027 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
6028 		errno = -EFSCORRUPTED;
6029 		goto out_bh;
6030 	}
6031 
6032 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
6033 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
6034 		errno = -EFSCORRUPTED;
6035 		goto out_bh;
6036 	}
6037 
6038 	*j_start = sb_block + 1;
6039 	*j_len = ext4_blocks_count(es);
6040 	brelse(bh);
6041 	return bdev_file;
6042 
6043 out_bh:
6044 	brelse(bh);
6045 out_bdev:
6046 	bdev_fput(bdev_file);
6047 	return ERR_PTR(errno);
6048 }
6049 
6050 static journal_t *ext4_open_dev_journal(struct super_block *sb,
6051 					dev_t j_dev)
6052 {
6053 	journal_t *journal;
6054 	ext4_fsblk_t j_start;
6055 	ext4_fsblk_t j_len;
6056 	struct file *bdev_file;
6057 	int errno = 0;
6058 
6059 	bdev_file = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
6060 	if (IS_ERR(bdev_file))
6061 		return ERR_CAST(bdev_file);
6062 
6063 	journal = jbd2_journal_init_dev(file_bdev(bdev_file), sb->s_bdev, j_start,
6064 					j_len, sb->s_blocksize);
6065 	if (IS_ERR(journal)) {
6066 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
6067 		errno = PTR_ERR(journal);
6068 		goto out_bdev;
6069 	}
6070 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
6071 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
6072 					"user (unsupported) - %d",
6073 			be32_to_cpu(journal->j_superblock->s_nr_users));
6074 		errno = -EINVAL;
6075 		goto out_journal;
6076 	}
6077 	journal->j_private = sb;
6078 	EXT4_SB(sb)->s_journal_bdev_file = bdev_file;
6079 	ext4_init_journal_params(sb, journal);
6080 	return journal;
6081 
6082 out_journal:
6083 	ext4_journal_destroy(EXT4_SB(sb), journal);
6084 out_bdev:
6085 	bdev_fput(bdev_file);
6086 	return ERR_PTR(errno);
6087 }
6088 
6089 static int ext4_load_journal(struct super_block *sb,
6090 			     struct ext4_super_block *es,
6091 			     unsigned long journal_devnum)
6092 {
6093 	journal_t *journal;
6094 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
6095 	dev_t journal_dev;
6096 	int err = 0;
6097 	int really_read_only;
6098 	int journal_dev_ro;
6099 
6100 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
6101 		return -EFSCORRUPTED;
6102 
6103 	if (journal_devnum &&
6104 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6105 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
6106 			"numbers have changed");
6107 		journal_dev = new_decode_dev(journal_devnum);
6108 	} else
6109 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
6110 
6111 	if (journal_inum && journal_dev) {
6112 		ext4_msg(sb, KERN_ERR,
6113 			 "filesystem has both journal inode and journal device!");
6114 		return -EINVAL;
6115 	}
6116 
6117 	if (journal_inum) {
6118 		journal = ext4_open_inode_journal(sb, journal_inum);
6119 		if (IS_ERR(journal))
6120 			return PTR_ERR(journal);
6121 	} else {
6122 		journal = ext4_open_dev_journal(sb, journal_dev);
6123 		if (IS_ERR(journal))
6124 			return PTR_ERR(journal);
6125 	}
6126 
6127 	journal_dev_ro = bdev_read_only(journal->j_dev);
6128 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
6129 
6130 	if (journal_dev_ro && !sb_rdonly(sb)) {
6131 		ext4_msg(sb, KERN_ERR,
6132 			 "journal device read-only, try mounting with '-o ro'");
6133 		err = -EROFS;
6134 		goto err_out;
6135 	}
6136 
6137 	/*
6138 	 * Are we loading a blank journal or performing recovery after a
6139 	 * crash?  For recovery, we need to check in advance whether we
6140 	 * can get read-write access to the device.
6141 	 */
6142 	if (ext4_has_feature_journal_needs_recovery(sb)) {
6143 		if (sb_rdonly(sb)) {
6144 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
6145 					"required on readonly filesystem");
6146 			if (really_read_only) {
6147 				ext4_msg(sb, KERN_ERR, "write access "
6148 					"unavailable, cannot proceed "
6149 					"(try mounting with noload)");
6150 				err = -EROFS;
6151 				goto err_out;
6152 			}
6153 			ext4_msg(sb, KERN_INFO, "write access will "
6154 			       "be enabled during recovery");
6155 		}
6156 	}
6157 
6158 	if (!(journal->j_flags & JBD2_BARRIER))
6159 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6160 
6161 	if (!ext4_has_feature_journal_needs_recovery(sb))
6162 		err = jbd2_journal_wipe(journal, !really_read_only);
6163 	if (!err) {
6164 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6165 		__le16 orig_state;
6166 		bool changed = false;
6167 
6168 		if (save)
6169 			memcpy(save, ((char *) es) +
6170 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6171 		err = jbd2_journal_load(journal);
6172 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6173 				   save, EXT4_S_ERR_LEN)) {
6174 			memcpy(((char *) es) + EXT4_S_ERR_START,
6175 			       save, EXT4_S_ERR_LEN);
6176 			changed = true;
6177 		}
6178 		kfree(save);
6179 		orig_state = es->s_state;
6180 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6181 					   EXT4_ERROR_FS);
6182 		if (orig_state != es->s_state)
6183 			changed = true;
6184 		/* Write out restored error information to the superblock */
6185 		if (changed && !really_read_only) {
6186 			int err2;
6187 			err2 = ext4_commit_super(sb);
6188 			err = err ? : err2;
6189 		}
6190 	}
6191 
6192 	if (err) {
6193 		ext4_msg(sb, KERN_ERR, "error loading journal");
6194 		goto err_out;
6195 	}
6196 
6197 	EXT4_SB(sb)->s_journal = journal;
6198 	err = ext4_clear_journal_err(sb, es);
6199 	if (err) {
6200 		ext4_journal_destroy(EXT4_SB(sb), journal);
6201 		return err;
6202 	}
6203 
6204 	if (!really_read_only && journal_devnum &&
6205 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6206 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6207 		ext4_commit_super(sb);
6208 	}
6209 	if (!really_read_only && journal_inum &&
6210 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6211 		es->s_journal_inum = cpu_to_le32(journal_inum);
6212 		ext4_commit_super(sb);
6213 	}
6214 
6215 	return 0;
6216 
6217 err_out:
6218 	ext4_journal_destroy(EXT4_SB(sb), journal);
6219 	return err;
6220 }
6221 
6222 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6223 static void ext4_update_super(struct super_block *sb)
6224 {
6225 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6226 	struct ext4_super_block *es = sbi->s_es;
6227 	struct buffer_head *sbh = sbi->s_sbh;
6228 
6229 	lock_buffer(sbh);
6230 	/*
6231 	 * If the file system is mounted read-only, don't update the
6232 	 * superblock write time.  This avoids updating the superblock
6233 	 * write time when we are mounting the root file system
6234 	 * read/only but we need to replay the journal; at that point,
6235 	 * for people who are east of GMT and who make their clock
6236 	 * tick in localtime for Windows bug-for-bug compatibility,
6237 	 * the clock is set in the future, and this will cause e2fsck
6238 	 * to complain and force a full file system check.
6239 	 */
6240 	if (!sb_rdonly(sb))
6241 		ext4_update_tstamp(es, s_wtime);
6242 	es->s_kbytes_written =
6243 		cpu_to_le64(sbi->s_kbytes_written +
6244 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6245 		      sbi->s_sectors_written_start) >> 1));
6246 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6247 		ext4_free_blocks_count_set(es,
6248 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6249 				&sbi->s_freeclusters_counter)));
6250 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6251 		es->s_free_inodes_count =
6252 			cpu_to_le32(percpu_counter_sum_positive(
6253 				&sbi->s_freeinodes_counter));
6254 	/* Copy error information to the on-disk superblock */
6255 	spin_lock(&sbi->s_error_lock);
6256 	if (sbi->s_add_error_count > 0) {
6257 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6258 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6259 			__ext4_update_tstamp(&es->s_first_error_time,
6260 					     &es->s_first_error_time_hi,
6261 					     sbi->s_first_error_time);
6262 			strtomem_pad(es->s_first_error_func,
6263 				     sbi->s_first_error_func, 0);
6264 			es->s_first_error_line =
6265 				cpu_to_le32(sbi->s_first_error_line);
6266 			es->s_first_error_ino =
6267 				cpu_to_le32(sbi->s_first_error_ino);
6268 			es->s_first_error_block =
6269 				cpu_to_le64(sbi->s_first_error_block);
6270 			es->s_first_error_errcode =
6271 				ext4_errno_to_code(sbi->s_first_error_code);
6272 		}
6273 		__ext4_update_tstamp(&es->s_last_error_time,
6274 				     &es->s_last_error_time_hi,
6275 				     sbi->s_last_error_time);
6276 		strtomem_pad(es->s_last_error_func, sbi->s_last_error_func, 0);
6277 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6278 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6279 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6280 		es->s_last_error_errcode =
6281 				ext4_errno_to_code(sbi->s_last_error_code);
6282 		/*
6283 		 * Start the daily error reporting function if it hasn't been
6284 		 * started already and sbi->s_err_report_sec is not zero
6285 		 */
6286 		if (!es->s_error_count && !sbi->s_err_report_sec)
6287 			mod_timer(&sbi->s_err_report,
6288 					  jiffies + secs_to_jiffies(sbi->s_err_report_sec));
6289 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6290 		sbi->s_add_error_count = 0;
6291 	}
6292 	spin_unlock(&sbi->s_error_lock);
6293 
6294 	ext4_superblock_csum_set(sb);
6295 	unlock_buffer(sbh);
6296 }
6297 
6298 static int ext4_commit_super(struct super_block *sb)
6299 {
6300 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6301 
6302 	if (!sbh)
6303 		return -EINVAL;
6304 
6305 	ext4_update_super(sb);
6306 
6307 	lock_buffer(sbh);
6308 	/* Buffer got discarded which means block device got invalidated */
6309 	if (!buffer_mapped(sbh)) {
6310 		unlock_buffer(sbh);
6311 		return -EIO;
6312 	}
6313 
6314 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6315 		/*
6316 		 * Oh, dear.  A previous attempt to write the
6317 		 * superblock failed.  This could happen because the
6318 		 * USB device was yanked out.  Or it could happen to
6319 		 * be a transient write error and maybe the block will
6320 		 * be remapped.  Nothing we can do but to retry the
6321 		 * write and hope for the best.
6322 		 */
6323 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6324 		       "superblock detected");
6325 		clear_buffer_write_io_error(sbh);
6326 		set_buffer_uptodate(sbh);
6327 	}
6328 	/* Clear potential dirty bit if it was journalled update */
6329 	clear_buffer_dirty(sbh);
6330 	bh_submit(sbh, REQ_OP_WRITE | REQ_SYNC |
6331 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), bh_end_write);
6332 	wait_on_buffer(sbh);
6333 	if (buffer_write_io_error(sbh)) {
6334 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6335 		       "superblock");
6336 		clear_buffer_write_io_error(sbh);
6337 		set_buffer_uptodate(sbh);
6338 		return -EIO;
6339 	}
6340 	return 0;
6341 }
6342 
6343 /*
6344  * Have we just finished recovery?  If so, and if we are mounting (or
6345  * remounting) the filesystem readonly, then we will end up with a
6346  * consistent fs on disk.  Record that fact.
6347  */
6348 static int ext4_mark_recovery_complete(struct super_block *sb,
6349 				       struct ext4_super_block *es)
6350 {
6351 	int err;
6352 	journal_t *journal = EXT4_SB(sb)->s_journal;
6353 
6354 	if (!ext4_has_feature_journal(sb)) {
6355 		if (journal != NULL) {
6356 			ext4_error(sb, "Journal got removed while the fs was "
6357 				   "mounted!");
6358 			return -EFSCORRUPTED;
6359 		}
6360 		return 0;
6361 	}
6362 	jbd2_journal_lock_updates(journal);
6363 	err = jbd2_journal_flush(journal, 0);
6364 	if (err < 0)
6365 		goto out;
6366 
6367 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6368 	    ext4_has_feature_orphan_present(sb))) {
6369 		if (!ext4_orphan_file_empty(sb)) {
6370 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6371 			err = -EFSCORRUPTED;
6372 			goto out;
6373 		}
6374 		ext4_clear_feature_journal_needs_recovery(sb);
6375 		ext4_clear_feature_orphan_present(sb);
6376 		ext4_commit_super(sb);
6377 	}
6378 out:
6379 	jbd2_journal_unlock_updates(journal);
6380 	return err;
6381 }
6382 
6383 /*
6384  * If we are mounting (or read-write remounting) a filesystem whose journal
6385  * has recorded an error from a previous lifetime, move that error to the
6386  * main filesystem now.
6387  */
6388 static int ext4_clear_journal_err(struct super_block *sb,
6389 				   struct ext4_super_block *es)
6390 {
6391 	journal_t *journal;
6392 	int j_errno;
6393 	const char *errstr;
6394 
6395 	if (!ext4_has_feature_journal(sb)) {
6396 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6397 		return -EFSCORRUPTED;
6398 	}
6399 
6400 	journal = EXT4_SB(sb)->s_journal;
6401 
6402 	/*
6403 	 * Now check for any error status which may have been recorded in the
6404 	 * journal by a prior ext4_error() or ext4_abort()
6405 	 */
6406 
6407 	j_errno = jbd2_journal_errno(journal);
6408 	if (j_errno) {
6409 		char nbuf[16];
6410 
6411 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6412 		ext4_warning(sb, "Filesystem error recorded "
6413 			     "from previous mount: %s", errstr);
6414 
6415 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6416 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6417 		j_errno = ext4_commit_super(sb);
6418 		if (j_errno)
6419 			return j_errno;
6420 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6421 
6422 		jbd2_journal_clear_err(journal);
6423 		jbd2_journal_update_sb_errno(journal);
6424 	}
6425 	return 0;
6426 }
6427 
6428 /*
6429  * Force the running and committing transactions to commit,
6430  * and wait on the commit.
6431  */
6432 int ext4_force_commit(struct super_block *sb)
6433 {
6434 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6435 }
6436 
6437 static int ext4_sync_fs(struct super_block *sb, int wait)
6438 {
6439 	int ret = 0;
6440 	tid_t target;
6441 	bool needs_barrier = false;
6442 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6443 
6444 	ret = ext4_emergency_state(sb);
6445 	if (unlikely(ret))
6446 		return ret;
6447 
6448 	trace_ext4_sync_fs(sb, wait);
6449 	flush_workqueue(sbi->rsv_conversion_wq);
6450 	/*
6451 	 * Writeback quota in non-journalled quota case - journalled quota has
6452 	 * no dirty dquots
6453 	 */
6454 	dquot_writeback_dquots(sb, -1);
6455 	/*
6456 	 * Data writeback is possible w/o journal transaction, so barrier must
6457 	 * being sent at the end of the function. But we can skip it if
6458 	 * transaction_commit will do it for us.
6459 	 */
6460 	if (sbi->s_journal) {
6461 		target = jbd2_get_latest_transaction(sbi->s_journal);
6462 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6463 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6464 			needs_barrier = true;
6465 
6466 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6467 			if (wait)
6468 				ret = jbd2_log_wait_commit(sbi->s_journal,
6469 							   target);
6470 		}
6471 	} else if (wait && test_opt(sb, BARRIER))
6472 		needs_barrier = true;
6473 	if (needs_barrier) {
6474 		int err;
6475 		err = blkdev_issue_flush(sb->s_bdev);
6476 		if (!ret)
6477 			ret = err;
6478 	}
6479 
6480 	return ret;
6481 }
6482 
6483 /*
6484  * LVM calls this function before a (read-only) snapshot is created.  This
6485  * gives us a chance to flush the journal completely and mark the fs clean.
6486  *
6487  * Note that only this function cannot bring a filesystem to be in a clean
6488  * state independently. It relies on upper layer to stop all data & metadata
6489  * modifications.
6490  */
6491 static int ext4_freeze(struct super_block *sb)
6492 {
6493 	int error = 0;
6494 	journal_t *journal = EXT4_SB(sb)->s_journal;
6495 
6496 	if (journal) {
6497 		/* Now we set up the journal barrier. */
6498 		jbd2_journal_lock_updates(journal);
6499 
6500 		/*
6501 		 * Don't clear the needs_recovery flag if we failed to
6502 		 * flush the journal.
6503 		 */
6504 		error = jbd2_journal_flush(journal, 0);
6505 		if (error < 0)
6506 			goto out;
6507 
6508 		/* Journal blocked and flushed, clear needs_recovery flag. */
6509 		ext4_clear_feature_journal_needs_recovery(sb);
6510 		if (ext4_orphan_file_empty(sb))
6511 			ext4_clear_feature_orphan_present(sb);
6512 	}
6513 
6514 	error = ext4_commit_super(sb);
6515 out:
6516 	if (journal)
6517 		/* we rely on upper layer to stop further updates */
6518 		jbd2_journal_unlock_updates(journal);
6519 	return error;
6520 }
6521 
6522 /*
6523  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6524  * flag here, even though the filesystem is not technically dirty yet.
6525  */
6526 static int ext4_unfreeze(struct super_block *sb)
6527 {
6528 	if (ext4_emergency_state(sb))
6529 		return 0;
6530 
6531 	if (EXT4_SB(sb)->s_journal) {
6532 		/* Reset the needs_recovery flag before the fs is unlocked. */
6533 		ext4_set_feature_journal_needs_recovery(sb);
6534 		if (ext4_has_feature_orphan_file(sb))
6535 			ext4_set_feature_orphan_present(sb);
6536 	}
6537 
6538 	ext4_commit_super(sb);
6539 	return 0;
6540 }
6541 
6542 /*
6543  * Structure to save mount options for ext4_remount's benefit
6544  */
6545 struct ext4_mount_options {
6546 	unsigned long s_mount_opt;
6547 	unsigned long s_mount_opt2;
6548 	kuid_t s_resuid;
6549 	kgid_t s_resgid;
6550 	unsigned long s_commit_interval;
6551 	u32 s_min_batch_time, s_max_batch_time;
6552 #ifdef CONFIG_QUOTA
6553 	int s_jquota_fmt;
6554 	char *s_qf_names[EXT4_MAXQUOTAS];
6555 #endif
6556 };
6557 
6558 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6559 {
6560 	struct ext4_fs_context *ctx = fc->fs_private;
6561 	struct ext4_super_block *es;
6562 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6563 	unsigned long old_sb_flags;
6564 	struct ext4_mount_options old_opts;
6565 	ext4_group_t g;
6566 	int err = 0;
6567 	int alloc_ctx;
6568 #ifdef CONFIG_QUOTA
6569 	int enable_quota = 0;
6570 	int i, j;
6571 	char *to_free[EXT4_MAXQUOTAS];
6572 #endif
6573 
6574 
6575 	/* Store the original options */
6576 	old_sb_flags = sb->s_flags;
6577 	old_opts.s_mount_opt = sbi->s_mount_opt;
6578 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6579 	old_opts.s_resuid = sbi->s_resuid;
6580 	old_opts.s_resgid = sbi->s_resgid;
6581 	old_opts.s_commit_interval = sbi->s_commit_interval;
6582 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6583 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6584 #ifdef CONFIG_QUOTA
6585 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6586 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6587 		if (sbi->s_qf_names[i]) {
6588 			char *qf_name = get_qf_name(sb, sbi, i);
6589 
6590 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6591 			if (!old_opts.s_qf_names[i]) {
6592 				for (j = 0; j < i; j++)
6593 					kfree(old_opts.s_qf_names[j]);
6594 				return -ENOMEM;
6595 			}
6596 		} else
6597 			old_opts.s_qf_names[i] = NULL;
6598 #endif
6599 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6600 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6601 			ctx->journal_ioprio =
6602 				sbi->s_journal->j_task->io_context->ioprio;
6603 		else
6604 			ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
6605 
6606 	}
6607 
6608 	if ((ctx->spec & EXT4_SPEC_s_stripe) &&
6609 	    ext4_is_stripe_incompatible(sb, ctx->s_stripe)) {
6610 		ext4_msg(sb, KERN_WARNING,
6611 			 "stripe (%lu) is not aligned with cluster size (%u), "
6612 			 "stripe is disabled",
6613 			 ctx->s_stripe, sbi->s_cluster_ratio);
6614 		ctx->s_stripe = 0;
6615 	}
6616 
6617 	/*
6618 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6619 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6620 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6621 	 * here s_writepages_rwsem to avoid race between writepages ops and
6622 	 * remount.
6623 	 */
6624 	alloc_ctx = ext4_writepages_down_write(sb);
6625 	ext4_apply_options(fc, sb);
6626 	ext4_writepages_up_write(sb, alloc_ctx);
6627 
6628 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6629 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6630 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6631 			 "during remount not supported; ignoring");
6632 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6633 	}
6634 
6635 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6636 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6637 			ext4_msg(sb, KERN_ERR, "can't mount with "
6638 				 "both data=journal and delalloc");
6639 			err = -EINVAL;
6640 			goto restore_opts;
6641 		}
6642 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6643 			ext4_msg(sb, KERN_ERR, "can't mount with "
6644 				 "both data=journal and dioread_nolock");
6645 			err = -EINVAL;
6646 			goto restore_opts;
6647 		}
6648 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6649 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6650 			ext4_msg(sb, KERN_ERR, "can't mount with "
6651 				"journal_async_commit in data=ordered mode");
6652 			err = -EINVAL;
6653 			goto restore_opts;
6654 		}
6655 	}
6656 
6657 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6658 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6659 		err = -EINVAL;
6660 		goto restore_opts;
6661 	}
6662 
6663 	if ((old_opts.s_mount_opt & EXT4_MOUNT_DELALLOC) &&
6664 	    !test_opt(sb, DELALLOC)) {
6665 		ext4_msg(sb, KERN_ERR, "can't disable delalloc during remount");
6666 		err = -EINVAL;
6667 		goto restore_opts;
6668 	}
6669 
6670 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6671 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6672 
6673 	es = sbi->s_es;
6674 
6675 	if (sbi->s_journal) {
6676 		ext4_init_journal_params(sb, sbi->s_journal);
6677 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6678 	}
6679 
6680 	/* Flush outstanding errors before changing fs state */
6681 	flush_work(&sbi->s_sb_upd_work);
6682 
6683 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6684 		if (ext4_emergency_state(sb)) {
6685 			err = -EROFS;
6686 			goto restore_opts;
6687 		}
6688 
6689 		if (fc->sb_flags & SB_RDONLY) {
6690 			err = sync_filesystem(sb);
6691 			if (err < 0)
6692 				goto restore_opts;
6693 			err = dquot_suspend(sb, -1);
6694 			if (err < 0)
6695 				goto restore_opts;
6696 
6697 			/*
6698 			 * First of all, the unconditional stuff we have to do
6699 			 * to disable replay of the journal when we next remount
6700 			 */
6701 			sb->s_flags |= SB_RDONLY;
6702 
6703 			/*
6704 			 * OK, test if we are remounting a valid rw partition
6705 			 * readonly, and if so set the rdonly flag and then
6706 			 * mark the partition as valid again.
6707 			 */
6708 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6709 			    (sbi->s_mount_state & EXT4_VALID_FS))
6710 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6711 
6712 			if (sbi->s_journal) {
6713 				/*
6714 				 * We let remount-ro finish even if marking fs
6715 				 * as clean failed...
6716 				 */
6717 				ext4_mark_recovery_complete(sb, es);
6718 			}
6719 		} else {
6720 			/* Make sure we can mount this feature set readwrite */
6721 			if (ext4_has_feature_readonly(sb) ||
6722 			    !ext4_feature_set_ok(sb, 0)) {
6723 				err = -EROFS;
6724 				goto restore_opts;
6725 			}
6726 			/*
6727 			 * Make sure the group descriptor checksums
6728 			 * are sane.  If they aren't, refuse to remount r/w.
6729 			 */
6730 			for (g = 0; g < sbi->s_groups_count; g++) {
6731 				struct ext4_group_desc *gdp =
6732 					ext4_get_group_desc(sb, g, NULL);
6733 
6734 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6735 					ext4_msg(sb, KERN_ERR,
6736 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6737 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6738 					       le16_to_cpu(gdp->bg_checksum));
6739 					err = -EFSBADCRC;
6740 					goto restore_opts;
6741 				}
6742 			}
6743 
6744 			/*
6745 			 * If we have an unprocessed orphan list hanging
6746 			 * around from a previously readonly bdev mount,
6747 			 * require a full umount/remount for now.
6748 			 */
6749 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6750 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6751 				       "remount RDWR because of unprocessed "
6752 				       "orphan inode list.  Please "
6753 				       "umount/remount instead");
6754 				err = -EINVAL;
6755 				goto restore_opts;
6756 			}
6757 
6758 			/*
6759 			 * Mounting a RDONLY partition read-write, so reread
6760 			 * and store the current valid flag.  (It may have
6761 			 * been changed by e2fsck since we originally mounted
6762 			 * the partition.)
6763 			 */
6764 			if (sbi->s_journal) {
6765 				err = ext4_clear_journal_err(sb, es);
6766 				if (err)
6767 					goto restore_opts;
6768 			}
6769 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6770 					      ~EXT4_FC_REPLAY);
6771 
6772 			err = ext4_setup_super(sb, es, 0);
6773 			if (err)
6774 				goto restore_opts;
6775 
6776 			sb->s_flags &= ~SB_RDONLY;
6777 			if (ext4_has_feature_mmp(sb)) {
6778 				err = ext4_multi_mount_protect(sb,
6779 						le64_to_cpu(es->s_mmp_block));
6780 				if (err)
6781 					goto restore_opts;
6782 			}
6783 #ifdef CONFIG_QUOTA
6784 			enable_quota = 1;
6785 #endif
6786 		}
6787 	}
6788 
6789 	/*
6790 	 * Handle creation of system zone data early because it can fail.
6791 	 * Releasing of existing data is done when we are sure remount will
6792 	 * succeed.
6793 	 */
6794 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6795 		err = ext4_setup_system_zone(sb);
6796 		if (err)
6797 			goto restore_opts;
6798 	}
6799 
6800 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6801 		err = ext4_commit_super(sb);
6802 		if (err)
6803 			goto restore_opts;
6804 	}
6805 
6806 #ifdef CONFIG_QUOTA
6807 	if (enable_quota) {
6808 		if (sb_any_quota_suspended(sb))
6809 			dquot_resume(sb, -1);
6810 		else if (ext4_has_feature_quota(sb)) {
6811 			err = ext4_enable_quotas(sb);
6812 			if (err)
6813 				goto restore_opts;
6814 		}
6815 	}
6816 	/* Release old quota file names */
6817 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6818 		kfree(old_opts.s_qf_names[i]);
6819 #endif
6820 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6821 		ext4_release_system_zone(sb);
6822 
6823 	/*
6824 	 * Reinitialize lazy itable initialization thread based on
6825 	 * current settings
6826 	 */
6827 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6828 		ext4_unregister_li_request(sb);
6829 	else {
6830 		ext4_group_t first_not_zeroed;
6831 		first_not_zeroed = ext4_has_uninit_itable(sb);
6832 		ext4_register_li_request(sb, first_not_zeroed);
6833 	}
6834 
6835 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6836 		ext4_stop_mmpd(sbi);
6837 
6838 	/*
6839 	 * Handle aborting the filesystem as the last thing during remount to
6840 	 * avoid obsure errors during remount when some option changes fail to
6841 	 * apply due to shutdown filesystem.
6842 	 */
6843 	if (test_opt2(sb, ABORT))
6844 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6845 
6846 	return 0;
6847 
6848 restore_opts:
6849 	/*
6850 	 * If there was a failing r/w to ro transition, we may need to
6851 	 * re-enable quota
6852 	 */
6853 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6854 	    sb_any_quota_suspended(sb))
6855 		dquot_resume(sb, -1);
6856 
6857 	alloc_ctx = ext4_writepages_down_write(sb);
6858 	sb->s_flags = old_sb_flags;
6859 	sbi->s_mount_opt = old_opts.s_mount_opt;
6860 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6861 	sbi->s_resuid = old_opts.s_resuid;
6862 	sbi->s_resgid = old_opts.s_resgid;
6863 	sbi->s_commit_interval = old_opts.s_commit_interval;
6864 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6865 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6866 	ext4_writepages_up_write(sb, alloc_ctx);
6867 
6868 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6869 		ext4_release_system_zone(sb);
6870 #ifdef CONFIG_QUOTA
6871 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6872 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6873 		to_free[i] = get_qf_name(sb, sbi, i);
6874 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6875 	}
6876 	synchronize_rcu();
6877 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6878 		kfree(to_free[i]);
6879 #endif
6880 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6881 		ext4_stop_mmpd(sbi);
6882 	return err;
6883 }
6884 
6885 static int ext4_reconfigure(struct fs_context *fc)
6886 {
6887 	struct super_block *sb = fc->root->d_sb;
6888 	int ret;
6889 	bool old_ro = sb_rdonly(sb);
6890 
6891 	fc->s_fs_info = EXT4_SB(sb);
6892 
6893 	ret = ext4_check_opt_consistency(fc, sb);
6894 	if (ret < 0)
6895 		return ret;
6896 
6897 	ret = __ext4_remount(fc, sb);
6898 	if (ret < 0)
6899 		return ret;
6900 
6901 	ext4_msg(sb, KERN_INFO, "re-mounted %pU%s.",
6902 		 &sb->s_uuid,
6903 		 (old_ro != sb_rdonly(sb)) ? (sb_rdonly(sb) ? " ro" : " r/w") : "");
6904 
6905 	return 0;
6906 }
6907 
6908 #ifdef CONFIG_QUOTA
6909 static int ext4_statfs_project(struct super_block *sb,
6910 			       kprojid_t projid, struct kstatfs *buf)
6911 {
6912 	struct kqid qid;
6913 	struct dquot *dquot;
6914 	u64 limit;
6915 	u64 curblock;
6916 
6917 	qid = make_kqid_projid(projid);
6918 	dquot = dqget(sb, qid);
6919 	if (IS_ERR(dquot))
6920 		return PTR_ERR(dquot);
6921 	spin_lock(&dquot->dq_dqb_lock);
6922 
6923 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6924 			     dquot->dq_dqb.dqb_bhardlimit);
6925 	limit >>= sb->s_blocksize_bits;
6926 
6927 	if (limit) {
6928 		uint64_t	remaining = 0;
6929 
6930 		curblock = (dquot->dq_dqb.dqb_curspace +
6931 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6932 		if (limit > curblock)
6933 			remaining = limit - curblock;
6934 
6935 		buf->f_blocks = min(buf->f_blocks, limit);
6936 		buf->f_bfree = min(buf->f_bfree, remaining);
6937 		buf->f_bavail = min(buf->f_bavail, remaining);
6938 	}
6939 
6940 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6941 			     dquot->dq_dqb.dqb_ihardlimit);
6942 	if (limit) {
6943 		uint64_t	remaining = 0;
6944 
6945 		if (limit > dquot->dq_dqb.dqb_curinodes)
6946 			remaining = limit - dquot->dq_dqb.dqb_curinodes;
6947 
6948 		buf->f_files = min(buf->f_files, limit);
6949 		buf->f_ffree = min(buf->f_ffree, remaining);
6950 	}
6951 
6952 	spin_unlock(&dquot->dq_dqb_lock);
6953 	dqput(dquot);
6954 	return 0;
6955 }
6956 #endif
6957 
6958 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6959 {
6960 	struct super_block *sb = dentry->d_sb;
6961 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6962 	struct ext4_super_block *es = sbi->s_es;
6963 	ext4_fsblk_t overhead = 0, resv_blocks;
6964 	s64 bfree;
6965 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6966 
6967 	if (!test_opt(sb, MINIX_DF))
6968 		overhead = sbi->s_overhead;
6969 
6970 	buf->f_type = EXT4_SUPER_MAGIC;
6971 	buf->f_bsize = sb->s_blocksize;
6972 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6973 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6974 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6975 	/* prevent underflow in case that few free space is available */
6976 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6977 	buf->f_bavail = buf->f_bfree -
6978 			(ext4_r_blocks_count(es) + resv_blocks);
6979 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6980 		buf->f_bavail = 0;
6981 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6982 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6983 	buf->f_namelen = EXT4_NAME_LEN;
6984 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6985 
6986 #ifdef CONFIG_QUOTA
6987 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6988 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6989 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6990 #endif
6991 	return 0;
6992 }
6993 
6994 
6995 #ifdef CONFIG_QUOTA
6996 
6997 /*
6998  * Helper functions so that transaction is started before we acquire dqio_sem
6999  * to keep correct lock ordering of transaction > dqio_sem
7000  */
7001 static inline struct inode *dquot_to_inode(struct dquot *dquot)
7002 {
7003 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
7004 }
7005 
7006 static int ext4_write_dquot(struct dquot *dquot)
7007 {
7008 	int ret, err;
7009 	handle_t *handle;
7010 	struct inode *inode;
7011 
7012 	inode = dquot_to_inode(dquot);
7013 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
7014 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
7015 	if (IS_ERR(handle))
7016 		return PTR_ERR(handle);
7017 	ret = dquot_commit(dquot);
7018 	if (ret < 0)
7019 		ext4_error_err(dquot->dq_sb, -ret,
7020 			       "Failed to commit dquot type %d",
7021 			       dquot->dq_id.type);
7022 	err = ext4_journal_stop(handle);
7023 	if (!ret)
7024 		ret = err;
7025 	return ret;
7026 }
7027 
7028 static int ext4_acquire_dquot(struct dquot *dquot)
7029 {
7030 	int ret, err;
7031 	handle_t *handle;
7032 
7033 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
7034 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
7035 	if (IS_ERR(handle))
7036 		return PTR_ERR(handle);
7037 	ret = dquot_acquire(dquot);
7038 	if (ret < 0)
7039 		ext4_error_err(dquot->dq_sb, -ret,
7040 			      "Failed to acquire dquot type %d",
7041 			      dquot->dq_id.type);
7042 	err = ext4_journal_stop(handle);
7043 	if (!ret)
7044 		ret = err;
7045 	return ret;
7046 }
7047 
7048 static int ext4_release_dquot(struct dquot *dquot)
7049 {
7050 	int ret, err;
7051 	handle_t *handle;
7052 	bool freeze_protected = false;
7053 
7054 	/*
7055 	 * Trying to sb_start_intwrite() in a running transaction
7056 	 * can result in a deadlock. Further, running transactions
7057 	 * are already protected from freezing.
7058 	 */
7059 	if (!ext4_journal_current_handle()) {
7060 		sb_start_intwrite(dquot->dq_sb);
7061 		freeze_protected = true;
7062 	}
7063 
7064 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
7065 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
7066 	if (IS_ERR(handle)) {
7067 		/* Release dquot anyway to avoid endless cycle in dqput() */
7068 		dquot_release(dquot);
7069 		if (freeze_protected)
7070 			sb_end_intwrite(dquot->dq_sb);
7071 		return PTR_ERR(handle);
7072 	}
7073 	ret = dquot_release(dquot);
7074 	if (ret < 0)
7075 		ext4_error_err(dquot->dq_sb, -ret,
7076 			       "Failed to release dquot type %d",
7077 			       dquot->dq_id.type);
7078 	err = ext4_journal_stop(handle);
7079 	if (!ret)
7080 		ret = err;
7081 
7082 	if (freeze_protected)
7083 		sb_end_intwrite(dquot->dq_sb);
7084 
7085 	return ret;
7086 }
7087 
7088 static int ext4_mark_dquot_dirty(struct dquot *dquot)
7089 {
7090 	struct super_block *sb = dquot->dq_sb;
7091 
7092 	if (ext4_is_quota_journalled(sb)) {
7093 		dquot_mark_dquot_dirty(dquot);
7094 		return ext4_write_dquot(dquot);
7095 	} else {
7096 		return dquot_mark_dquot_dirty(dquot);
7097 	}
7098 }
7099 
7100 static int ext4_write_info(struct super_block *sb, int type)
7101 {
7102 	int ret, err;
7103 	handle_t *handle;
7104 
7105 	/* Data block + inode block */
7106 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
7107 	if (IS_ERR(handle))
7108 		return PTR_ERR(handle);
7109 	ret = dquot_commit_info(sb, type);
7110 	err = ext4_journal_stop(handle);
7111 	if (!ret)
7112 		ret = err;
7113 	return ret;
7114 }
7115 
7116 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
7117 {
7118 	struct ext4_inode_info *ei = EXT4_I(inode);
7119 
7120 	/* The first argument of lockdep_set_subclass has to be
7121 	 * *exactly* the same as the argument to init_rwsem() --- in
7122 	 * this case, in init_once() --- or lockdep gets unhappy
7123 	 * because the name of the lock is set using the
7124 	 * stringification of the argument to init_rwsem().
7125 	 */
7126 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
7127 	lockdep_set_subclass(&ei->i_data_sem, subclass);
7128 }
7129 
7130 /*
7131  * Standard function to be called on quota_on
7132  */
7133 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
7134 			 const struct path *path)
7135 {
7136 	int err;
7137 
7138 	if (!test_opt(sb, QUOTA))
7139 		return -EINVAL;
7140 
7141 	/* Quotafile not on the same filesystem? */
7142 	if (path->dentry->d_sb != sb)
7143 		return -EXDEV;
7144 
7145 	/* Quota already enabled for this file? */
7146 	if (IS_NOQUOTA(d_inode(path->dentry)))
7147 		return -EBUSY;
7148 
7149 	/* Journaling quota? */
7150 	if (EXT4_SB(sb)->s_qf_names[type]) {
7151 		/* Quotafile not in fs root? */
7152 		if (path->dentry->d_parent != sb->s_root)
7153 			ext4_msg(sb, KERN_WARNING,
7154 				"Quota file not on filesystem root. "
7155 				"Journaled quota will not work");
7156 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
7157 	} else {
7158 		/*
7159 		 * Clear the flag just in case mount options changed since
7160 		 * last time.
7161 		 */
7162 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
7163 	}
7164 
7165 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
7166 	err = dquot_quota_on(sb, type, format_id, path);
7167 	if (!err) {
7168 		struct inode *inode = d_inode(path->dentry);
7169 		handle_t *handle;
7170 
7171 		/*
7172 		 * Set inode flags to prevent userspace from messing with quota
7173 		 * files. If this fails, we return success anyway since quotas
7174 		 * are already enabled and this is not a hard failure.
7175 		 */
7176 		inode_lock(inode);
7177 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7178 		if (IS_ERR(handle))
7179 			goto unlock_inode;
7180 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
7181 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
7182 				S_NOATIME | S_IMMUTABLE);
7183 		err = ext4_mark_inode_dirty(handle, inode);
7184 		ext4_journal_stop(handle);
7185 	unlock_inode:
7186 		inode_unlock(inode);
7187 		if (err)
7188 			dquot_quota_off(sb, type);
7189 	}
7190 	if (err)
7191 		lockdep_set_quota_inode(path->dentry->d_inode,
7192 					     I_DATA_SEM_NORMAL);
7193 	return err;
7194 }
7195 
7196 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
7197 {
7198 	switch (type) {
7199 	case USRQUOTA:
7200 		return qf_inum == EXT4_USR_QUOTA_INO;
7201 	case GRPQUOTA:
7202 		return qf_inum == EXT4_GRP_QUOTA_INO;
7203 	case PRJQUOTA:
7204 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7205 	default:
7206 		BUG();
7207 	}
7208 }
7209 
7210 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7211 			     unsigned int flags)
7212 {
7213 	int err;
7214 	struct inode *qf_inode;
7215 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7216 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7217 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7218 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7219 	};
7220 
7221 	BUG_ON(!ext4_has_feature_quota(sb));
7222 
7223 	if (!qf_inums[type])
7224 		return -EPERM;
7225 
7226 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7227 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7228 				qf_inums[type], type);
7229 		return -EUCLEAN;
7230 	}
7231 
7232 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7233 	if (IS_ERR(qf_inode)) {
7234 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7235 				qf_inums[type], type);
7236 		return PTR_ERR(qf_inode);
7237 	}
7238 
7239 	/* Don't account quota for quota files to avoid recursion */
7240 	qf_inode->i_flags |= S_NOQUOTA;
7241 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7242 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7243 	if (err)
7244 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7245 	iput(qf_inode);
7246 
7247 	return err;
7248 }
7249 
7250 /* Enable usage tracking for all quota types. */
7251 int ext4_enable_quotas(struct super_block *sb)
7252 {
7253 	int type, err = 0;
7254 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7255 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7256 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7257 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7258 	};
7259 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7260 		test_opt(sb, USRQUOTA),
7261 		test_opt(sb, GRPQUOTA),
7262 		test_opt(sb, PRJQUOTA),
7263 	};
7264 
7265 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7266 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7267 		if (qf_inums[type]) {
7268 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7269 				DQUOT_USAGE_ENABLED |
7270 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7271 			if (err) {
7272 				ext4_warning(sb,
7273 					"Failed to enable quota tracking "
7274 					"(type=%d, err=%d, ino=%lu). "
7275 					"Please run e2fsck to fix.", type,
7276 					err, qf_inums[type]);
7277 
7278 				ext4_quotas_off(sb, type);
7279 				return err;
7280 			}
7281 		}
7282 	}
7283 	return 0;
7284 }
7285 
7286 static int ext4_quota_off(struct super_block *sb, int type)
7287 {
7288 	struct inode *inode = sb_dqopt(sb)->files[type];
7289 	handle_t *handle;
7290 	int err;
7291 
7292 	/* Force all delayed allocation blocks to be allocated.
7293 	 * Caller already holds s_umount sem */
7294 	if (test_opt(sb, DELALLOC))
7295 		sync_filesystem(sb);
7296 
7297 	if (!inode || !igrab(inode))
7298 		goto out;
7299 
7300 	err = dquot_quota_off(sb, type);
7301 	if (err || ext4_has_feature_quota(sb))
7302 		goto out_put;
7303 	/*
7304 	 * When the filesystem was remounted read-only first, we cannot cleanup
7305 	 * inode flags here. Bad luck but people should be using QUOTA feature
7306 	 * these days anyway.
7307 	 */
7308 	if (sb_rdonly(sb))
7309 		goto out_put;
7310 
7311 	inode_lock(inode);
7312 	/*
7313 	 * Update modification times of quota files when userspace can
7314 	 * start looking at them. If we fail, we return success anyway since
7315 	 * this is not a hard failure and quotas are already disabled.
7316 	 */
7317 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7318 	if (IS_ERR(handle)) {
7319 		err = PTR_ERR(handle);
7320 		goto out_unlock;
7321 	}
7322 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7323 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7324 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
7325 	err = ext4_mark_inode_dirty(handle, inode);
7326 	ext4_journal_stop(handle);
7327 out_unlock:
7328 	inode_unlock(inode);
7329 out_put:
7330 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7331 	iput(inode);
7332 	return err;
7333 out:
7334 	return dquot_quota_off(sb, type);
7335 }
7336 
7337 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7338  * acquiring the locks... As quota files are never truncated and quota code
7339  * itself serializes the operations (and no one else should touch the files)
7340  * we don't have to be afraid of races */
7341 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7342 			       size_t len, loff_t off)
7343 {
7344 	struct inode *inode = sb_dqopt(sb)->files[type];
7345 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7346 	int offset = off & (sb->s_blocksize - 1);
7347 	int tocopy;
7348 	size_t toread;
7349 	struct buffer_head *bh;
7350 	loff_t i_size = i_size_read(inode);
7351 
7352 	if (off > i_size)
7353 		return 0;
7354 	if (off+len > i_size)
7355 		len = i_size-off;
7356 	toread = len;
7357 	while (toread > 0) {
7358 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7359 		bh = ext4_bread(NULL, inode, blk, 0);
7360 		if (IS_ERR(bh))
7361 			return PTR_ERR(bh);
7362 		if (!bh)	/* A hole? */
7363 			memset(data, 0, tocopy);
7364 		else
7365 			memcpy(data, bh->b_data+offset, tocopy);
7366 		brelse(bh);
7367 		offset = 0;
7368 		toread -= tocopy;
7369 		data += tocopy;
7370 		blk++;
7371 	}
7372 	return len;
7373 }
7374 
7375 /* Write to quotafile (we know the transaction is already started and has
7376  * enough credits) */
7377 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7378 				const char *data, size_t len, loff_t off)
7379 {
7380 	struct inode *inode = sb_dqopt(sb)->files[type];
7381 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7382 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7383 	int retries = 0;
7384 	struct buffer_head *bh;
7385 	handle_t *handle = journal_current_handle();
7386 
7387 	if (!handle) {
7388 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7389 			" cancelled because transaction is not started",
7390 			(unsigned long long)off, (unsigned long long)len);
7391 		return -EIO;
7392 	}
7393 	/*
7394 	 * Since we account only one data block in transaction credits,
7395 	 * then it is impossible to cross a block boundary.
7396 	 */
7397 	if (sb->s_blocksize - offset < len) {
7398 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7399 			" cancelled because not block aligned",
7400 			(unsigned long long)off, (unsigned long long)len);
7401 		return -EIO;
7402 	}
7403 
7404 	do {
7405 		bh = ext4_bread(handle, inode, blk,
7406 				EXT4_GET_BLOCKS_CREATE |
7407 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7408 	} while (PTR_ERR(bh) == -ENOSPC &&
7409 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7410 	if (IS_ERR(bh))
7411 		return PTR_ERR(bh);
7412 	if (!bh)
7413 		goto out;
7414 	BUFFER_TRACE(bh, "get write access");
7415 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7416 	if (err) {
7417 		brelse(bh);
7418 		return err;
7419 	}
7420 	lock_buffer(bh);
7421 	memcpy(bh->b_data+offset, data, len);
7422 	flush_dcache_folio(bh->b_folio);
7423 	unlock_buffer(bh);
7424 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7425 	brelse(bh);
7426 out:
7427 	if (inode->i_size < off + len) {
7428 		i_size_write(inode, off + len);
7429 		EXT4_I(inode)->i_disksize = inode->i_size;
7430 		err2 = ext4_mark_inode_dirty(handle, inode);
7431 		if (unlikely(err2 && !err))
7432 			err = err2;
7433 	}
7434 	return err ? err : len;
7435 }
7436 #endif
7437 
7438 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7439 static inline void register_as_ext2(void)
7440 {
7441 	int err = register_filesystem(&ext2_fs_type);
7442 	if (err)
7443 		printk(KERN_WARNING
7444 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7445 }
7446 
7447 static inline void unregister_as_ext2(void)
7448 {
7449 	unregister_filesystem(&ext2_fs_type);
7450 }
7451 
7452 static inline int ext2_feature_set_ok(struct super_block *sb)
7453 {
7454 	if (ext4_has_unknown_ext2_incompat_features(sb))
7455 		return 0;
7456 	if (sb_rdonly(sb))
7457 		return 1;
7458 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7459 		return 0;
7460 	return 1;
7461 }
7462 #else
7463 static inline void register_as_ext2(void) { }
7464 static inline void unregister_as_ext2(void) { }
7465 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7466 #endif
7467 
7468 static inline void register_as_ext3(void)
7469 {
7470 	int err = register_filesystem(&ext3_fs_type);
7471 	if (err)
7472 		printk(KERN_WARNING
7473 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7474 }
7475 
7476 static inline void unregister_as_ext3(void)
7477 {
7478 	unregister_filesystem(&ext3_fs_type);
7479 }
7480 
7481 static inline int ext3_feature_set_ok(struct super_block *sb)
7482 {
7483 	if (ext4_has_unknown_ext3_incompat_features(sb))
7484 		return 0;
7485 	if (!ext4_has_feature_journal(sb))
7486 		return 0;
7487 	if (sb_rdonly(sb))
7488 		return 1;
7489 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7490 		return 0;
7491 	return 1;
7492 }
7493 
7494 static void ext4_kill_sb(struct super_block *sb)
7495 {
7496 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7497 	struct file *bdev_file = sbi ? sbi->s_journal_bdev_file : NULL;
7498 
7499 	kill_block_super(sb);
7500 
7501 	if (bdev_file)
7502 		bdev_fput(bdev_file);
7503 }
7504 
7505 static struct file_system_type ext4_fs_type = {
7506 	.owner			= THIS_MODULE,
7507 	.name			= "ext4",
7508 	.init_fs_context	= ext4_init_fs_context,
7509 	.parameters		= ext4_param_specs,
7510 	.kill_sb		= ext4_kill_sb,
7511 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME |
7512 				  FS_LBS,
7513 };
7514 MODULE_ALIAS_FS("ext4");
7515 
7516 static int __init ext4_init_fs(void)
7517 {
7518 	int err;
7519 
7520 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7521 	ext4_li_info = NULL;
7522 
7523 	/* Build-time check for flags consistency */
7524 	ext4_check_flag_values();
7525 
7526 	err = ext4_init_es();
7527 	if (err)
7528 		return err;
7529 
7530 	err = ext4_init_pending();
7531 	if (err)
7532 		goto out7;
7533 
7534 	err = ext4_init_post_read_processing();
7535 	if (err)
7536 		goto out6;
7537 
7538 	err = ext4_init_pageio();
7539 	if (err)
7540 		goto out5;
7541 
7542 	err = ext4_init_system_zone();
7543 	if (err)
7544 		goto out4;
7545 
7546 	err = ext4_init_sysfs();
7547 	if (err)
7548 		goto out3;
7549 
7550 	err = ext4_init_mballoc();
7551 	if (err)
7552 		goto out2;
7553 	err = init_inodecache();
7554 	if (err)
7555 		goto out1;
7556 
7557 	err = ext4_fc_init_dentry_cache();
7558 	if (err)
7559 		goto out05;
7560 
7561 	register_as_ext3();
7562 	register_as_ext2();
7563 	err = register_filesystem(&ext4_fs_type);
7564 	if (err)
7565 		goto out;
7566 
7567 	return 0;
7568 out:
7569 	unregister_as_ext2();
7570 	unregister_as_ext3();
7571 	ext4_fc_destroy_dentry_cache();
7572 out05:
7573 	destroy_inodecache();
7574 out1:
7575 	ext4_exit_mballoc();
7576 out2:
7577 	ext4_exit_sysfs();
7578 out3:
7579 	ext4_exit_system_zone();
7580 out4:
7581 	ext4_exit_pageio();
7582 out5:
7583 	ext4_exit_post_read_processing();
7584 out6:
7585 	ext4_exit_pending();
7586 out7:
7587 	ext4_exit_es();
7588 
7589 	return err;
7590 }
7591 
7592 static void __exit ext4_exit_fs(void)
7593 {
7594 	ext4_destroy_lazyinit_thread();
7595 	unregister_as_ext2();
7596 	unregister_as_ext3();
7597 	unregister_filesystem(&ext4_fs_type);
7598 	ext4_fc_destroy_dentry_cache();
7599 	destroy_inodecache();
7600 	ext4_exit_mballoc();
7601 	ext4_exit_sysfs();
7602 	ext4_exit_system_zone();
7603 	ext4_exit_pageio();
7604 	ext4_exit_post_read_processing();
7605 	ext4_exit_es();
7606 	ext4_exit_pending();
7607 }
7608 
7609 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7610 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7611 MODULE_LICENSE("GPL");
7612 module_init(ext4_init_fs)
7613 module_exit(ext4_exit_fs)
7614