xref: /linux/fs/ext4/super.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static void ext4_kill_sb(struct super_block *sb);
97 static const struct fs_parameter_spec ext4_param_specs[];
98 
99 /*
100  * Lock ordering
101  *
102  * page fault path:
103  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
104  *   -> page lock -> i_data_sem (rw)
105  *
106  * buffered write path:
107  * sb_start_write -> i_mutex -> mmap_lock
108  * sb_start_write -> i_mutex -> transaction start -> page lock ->
109  *   i_data_sem (rw)
110  *
111  * truncate:
112  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
113  *   page lock
114  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
115  *   i_data_sem (rw)
116  *
117  * direct IO:
118  * sb_start_write -> i_mutex -> mmap_lock
119  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
120  *
121  * writepages:
122  * transaction start -> page lock(s) -> i_data_sem (rw)
123  */
124 
125 static const struct fs_context_operations ext4_context_ops = {
126 	.parse_param	= ext4_parse_param,
127 	.get_tree	= ext4_get_tree,
128 	.reconfigure	= ext4_reconfigure,
129 	.free		= ext4_fc_free,
130 };
131 
132 
133 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
134 static struct file_system_type ext2_fs_type = {
135 	.owner			= THIS_MODULE,
136 	.name			= "ext2",
137 	.init_fs_context	= ext4_init_fs_context,
138 	.parameters		= ext4_param_specs,
139 	.kill_sb		= ext4_kill_sb,
140 	.fs_flags		= FS_REQUIRES_DEV,
141 };
142 MODULE_ALIAS_FS("ext2");
143 MODULE_ALIAS("ext2");
144 #define IS_EXT2_SB(sb) ((sb)->s_type == &ext2_fs_type)
145 #else
146 #define IS_EXT2_SB(sb) (0)
147 #endif
148 
149 
150 static struct file_system_type ext3_fs_type = {
151 	.owner			= THIS_MODULE,
152 	.name			= "ext3",
153 	.init_fs_context	= ext4_init_fs_context,
154 	.parameters		= ext4_param_specs,
155 	.kill_sb		= ext4_kill_sb,
156 	.fs_flags		= FS_REQUIRES_DEV,
157 };
158 MODULE_ALIAS_FS("ext3");
159 MODULE_ALIAS("ext3");
160 #define IS_EXT3_SB(sb) ((sb)->s_type == &ext3_fs_type)
161 
162 
163 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
164 				  bh_end_io_t *end_io)
165 {
166 	/*
167 	 * buffer's verified bit is no longer valid after reading from
168 	 * disk again due to write out error, clear it to make sure we
169 	 * recheck the buffer contents.
170 	 */
171 	clear_buffer_verified(bh);
172 
173 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
174 	get_bh(bh);
175 	submit_bh(REQ_OP_READ | op_flags, bh);
176 }
177 
178 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
179 			 bh_end_io_t *end_io)
180 {
181 	BUG_ON(!buffer_locked(bh));
182 
183 	if (ext4_buffer_uptodate(bh)) {
184 		unlock_buffer(bh);
185 		return;
186 	}
187 	__ext4_read_bh(bh, op_flags, end_io);
188 }
189 
190 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
191 {
192 	BUG_ON(!buffer_locked(bh));
193 
194 	if (ext4_buffer_uptodate(bh)) {
195 		unlock_buffer(bh);
196 		return 0;
197 	}
198 
199 	__ext4_read_bh(bh, op_flags, end_io);
200 
201 	wait_on_buffer(bh);
202 	if (buffer_uptodate(bh))
203 		return 0;
204 	return -EIO;
205 }
206 
207 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
208 {
209 	lock_buffer(bh);
210 	if (!wait) {
211 		ext4_read_bh_nowait(bh, op_flags, NULL);
212 		return 0;
213 	}
214 	return ext4_read_bh(bh, op_flags, NULL);
215 }
216 
217 /*
218  * This works like __bread_gfp() except it uses ERR_PTR for error
219  * returns.  Currently with sb_bread it's impossible to distinguish
220  * between ENOMEM and EIO situations (since both result in a NULL
221  * return.
222  */
223 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
224 					       sector_t block,
225 					       blk_opf_t op_flags, gfp_t gfp)
226 {
227 	struct buffer_head *bh;
228 	int ret;
229 
230 	bh = sb_getblk_gfp(sb, block, gfp);
231 	if (bh == NULL)
232 		return ERR_PTR(-ENOMEM);
233 	if (ext4_buffer_uptodate(bh))
234 		return bh;
235 
236 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
237 	if (ret) {
238 		put_bh(bh);
239 		return ERR_PTR(ret);
240 	}
241 	return bh;
242 }
243 
244 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
245 				   blk_opf_t op_flags)
246 {
247 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
248 			~__GFP_FS) | __GFP_MOVABLE;
249 
250 	return __ext4_sb_bread_gfp(sb, block, op_flags, gfp);
251 }
252 
253 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
254 					    sector_t block)
255 {
256 	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
257 			~__GFP_FS);
258 
259 	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
260 }
261 
262 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
263 {
264 	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
265 			sb->s_blocksize, GFP_NOWAIT | __GFP_NOWARN);
266 
267 	if (likely(bh)) {
268 		if (trylock_buffer(bh))
269 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
270 		brelse(bh);
271 	}
272 }
273 
274 static int ext4_verify_csum_type(struct super_block *sb,
275 				 struct ext4_super_block *es)
276 {
277 	if (!ext4_has_feature_metadata_csum(sb))
278 		return 1;
279 
280 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
281 }
282 
283 __le32 ext4_superblock_csum(struct super_block *sb,
284 			    struct ext4_super_block *es)
285 {
286 	struct ext4_sb_info *sbi = EXT4_SB(sb);
287 	int offset = offsetof(struct ext4_super_block, s_checksum);
288 	__u32 csum;
289 
290 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
291 
292 	return cpu_to_le32(csum);
293 }
294 
295 static int ext4_superblock_csum_verify(struct super_block *sb,
296 				       struct ext4_super_block *es)
297 {
298 	if (!ext4_has_metadata_csum(sb))
299 		return 1;
300 
301 	return es->s_checksum == ext4_superblock_csum(sb, es);
302 }
303 
304 void ext4_superblock_csum_set(struct super_block *sb)
305 {
306 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
307 
308 	if (!ext4_has_metadata_csum(sb))
309 		return;
310 
311 	es->s_checksum = ext4_superblock_csum(sb, es);
312 }
313 
314 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
323 			       struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
328 }
329 
330 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
331 			      struct ext4_group_desc *bg)
332 {
333 	return le32_to_cpu(bg->bg_inode_table_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
336 }
337 
338 __u32 ext4_free_group_clusters(struct super_block *sb,
339 			       struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_free_inodes_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
352 }
353 
354 __u32 ext4_used_dirs_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
360 }
361 
362 __u32 ext4_itable_unused_count(struct super_block *sb,
363 			      struct ext4_group_desc *bg)
364 {
365 	return le16_to_cpu(bg->bg_itable_unused_lo) |
366 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
367 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
368 }
369 
370 void ext4_block_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_bitmap_set(struct super_block *sb,
379 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_inode_table_set(struct super_block *sb,
387 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
388 {
389 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
392 }
393 
394 void ext4_free_group_clusters_set(struct super_block *sb,
395 				  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_free_inodes_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
408 }
409 
410 void ext4_used_dirs_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
416 }
417 
418 void ext4_itable_unused_set(struct super_block *sb,
419 			  struct ext4_group_desc *bg, __u32 count)
420 {
421 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
422 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
423 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
424 }
425 
426 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
427 {
428 	now = clamp_val(now, 0, (1ull << 40) - 1);
429 
430 	*lo = cpu_to_le32(lower_32_bits(now));
431 	*hi = upper_32_bits(now);
432 }
433 
434 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
435 {
436 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
437 }
438 #define ext4_update_tstamp(es, tstamp) \
439 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
440 			     ktime_get_real_seconds())
441 #define ext4_get_tstamp(es, tstamp) \
442 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
443 
444 #define EXT4_SB_REFRESH_INTERVAL_SEC (3600) /* seconds (1 hour) */
445 #define EXT4_SB_REFRESH_INTERVAL_KB (16384) /* kilobytes (16MB) */
446 
447 /*
448  * The ext4_maybe_update_superblock() function checks and updates the
449  * superblock if needed.
450  *
451  * This function is designed to update the on-disk superblock only under
452  * certain conditions to prevent excessive disk writes and unnecessary
453  * waking of the disk from sleep. The superblock will be updated if:
454  * 1. More than an hour has passed since the last superblock update, and
455  * 2. More than 16MB have been written since the last superblock update.
456  *
457  * @sb: The superblock
458  */
459 static void ext4_maybe_update_superblock(struct super_block *sb)
460 {
461 	struct ext4_sb_info *sbi = EXT4_SB(sb);
462 	struct ext4_super_block *es = sbi->s_es;
463 	journal_t *journal = sbi->s_journal;
464 	time64_t now;
465 	__u64 last_update;
466 	__u64 lifetime_write_kbytes;
467 	__u64 diff_size;
468 
469 	if (sb_rdonly(sb) || !(sb->s_flags & SB_ACTIVE) ||
470 	    !journal || (journal->j_flags & JBD2_UNMOUNT))
471 		return;
472 
473 	now = ktime_get_real_seconds();
474 	last_update = ext4_get_tstamp(es, s_wtime);
475 
476 	if (likely(now - last_update < EXT4_SB_REFRESH_INTERVAL_SEC))
477 		return;
478 
479 	lifetime_write_kbytes = sbi->s_kbytes_written +
480 		((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
481 		  sbi->s_sectors_written_start) >> 1);
482 
483 	/* Get the number of kilobytes not written to disk to account
484 	 * for statistics and compare with a multiple of 16 MB. This
485 	 * is used to determine when the next superblock commit should
486 	 * occur (i.e. not more often than once per 16MB if there was
487 	 * less written in an hour).
488 	 */
489 	diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written);
490 
491 	if (diff_size > EXT4_SB_REFRESH_INTERVAL_KB)
492 		schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
493 }
494 
495 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
496 {
497 	struct super_block		*sb = journal->j_private;
498 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
499 	int				error = is_journal_aborted(journal);
500 	struct ext4_journal_cb_entry	*jce;
501 
502 	BUG_ON(txn->t_state == T_FINISHED);
503 
504 	ext4_process_freed_data(sb, txn->t_tid);
505 	ext4_maybe_update_superblock(sb);
506 
507 	spin_lock(&sbi->s_md_lock);
508 	while (!list_empty(&txn->t_private_list)) {
509 		jce = list_entry(txn->t_private_list.next,
510 				 struct ext4_journal_cb_entry, jce_list);
511 		list_del_init(&jce->jce_list);
512 		spin_unlock(&sbi->s_md_lock);
513 		jce->jce_func(sb, jce, error);
514 		spin_lock(&sbi->s_md_lock);
515 	}
516 	spin_unlock(&sbi->s_md_lock);
517 }
518 
519 /*
520  * This writepage callback for write_cache_pages()
521  * takes care of a few cases after page cleaning.
522  *
523  * write_cache_pages() already checks for dirty pages
524  * and calls clear_page_dirty_for_io(), which we want,
525  * to write protect the pages.
526  *
527  * However, we may have to redirty a page (see below.)
528  */
529 static int ext4_journalled_writepage_callback(struct folio *folio,
530 					      struct writeback_control *wbc,
531 					      void *data)
532 {
533 	transaction_t *transaction = (transaction_t *) data;
534 	struct buffer_head *bh, *head;
535 	struct journal_head *jh;
536 
537 	bh = head = folio_buffers(folio);
538 	do {
539 		/*
540 		 * We have to redirty a page in these cases:
541 		 * 1) If buffer is dirty, it means the page was dirty because it
542 		 * contains a buffer that needs checkpointing. So the dirty bit
543 		 * needs to be preserved so that checkpointing writes the buffer
544 		 * properly.
545 		 * 2) If buffer is not part of the committing transaction
546 		 * (we may have just accidentally come across this buffer because
547 		 * inode range tracking is not exact) or if the currently running
548 		 * transaction already contains this buffer as well, dirty bit
549 		 * needs to be preserved so that the buffer gets writeprotected
550 		 * properly on running transaction's commit.
551 		 */
552 		jh = bh2jh(bh);
553 		if (buffer_dirty(bh) ||
554 		    (jh && (jh->b_transaction != transaction ||
555 			    jh->b_next_transaction))) {
556 			folio_redirty_for_writepage(wbc, folio);
557 			goto out;
558 		}
559 	} while ((bh = bh->b_this_page) != head);
560 
561 out:
562 	return AOP_WRITEPAGE_ACTIVATE;
563 }
564 
565 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
566 {
567 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
568 	struct writeback_control wbc = {
569 		.sync_mode =  WB_SYNC_ALL,
570 		.nr_to_write = LONG_MAX,
571 		.range_start = jinode->i_dirty_start,
572 		.range_end = jinode->i_dirty_end,
573         };
574 
575 	return write_cache_pages(mapping, &wbc,
576 				 ext4_journalled_writepage_callback,
577 				 jinode->i_transaction);
578 }
579 
580 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
581 {
582 	int ret;
583 
584 	if (ext4_should_journal_data(jinode->i_vfs_inode))
585 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
586 	else
587 		ret = ext4_normal_submit_inode_data_buffers(jinode);
588 	return ret;
589 }
590 
591 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
592 {
593 	int ret = 0;
594 
595 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
596 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
597 
598 	return ret;
599 }
600 
601 static bool system_going_down(void)
602 {
603 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
604 		|| system_state == SYSTEM_RESTART;
605 }
606 
607 struct ext4_err_translation {
608 	int code;
609 	int errno;
610 };
611 
612 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
613 
614 static struct ext4_err_translation err_translation[] = {
615 	EXT4_ERR_TRANSLATE(EIO),
616 	EXT4_ERR_TRANSLATE(ENOMEM),
617 	EXT4_ERR_TRANSLATE(EFSBADCRC),
618 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
619 	EXT4_ERR_TRANSLATE(ENOSPC),
620 	EXT4_ERR_TRANSLATE(ENOKEY),
621 	EXT4_ERR_TRANSLATE(EROFS),
622 	EXT4_ERR_TRANSLATE(EFBIG),
623 	EXT4_ERR_TRANSLATE(EEXIST),
624 	EXT4_ERR_TRANSLATE(ERANGE),
625 	EXT4_ERR_TRANSLATE(EOVERFLOW),
626 	EXT4_ERR_TRANSLATE(EBUSY),
627 	EXT4_ERR_TRANSLATE(ENOTDIR),
628 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
629 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
630 	EXT4_ERR_TRANSLATE(EFAULT),
631 };
632 
633 static int ext4_errno_to_code(int errno)
634 {
635 	int i;
636 
637 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
638 		if (err_translation[i].errno == errno)
639 			return err_translation[i].code;
640 	return EXT4_ERR_UNKNOWN;
641 }
642 
643 static void save_error_info(struct super_block *sb, int error,
644 			    __u32 ino, __u64 block,
645 			    const char *func, unsigned int line)
646 {
647 	struct ext4_sb_info *sbi = EXT4_SB(sb);
648 
649 	/* We default to EFSCORRUPTED error... */
650 	if (error == 0)
651 		error = EFSCORRUPTED;
652 
653 	spin_lock(&sbi->s_error_lock);
654 	sbi->s_add_error_count++;
655 	sbi->s_last_error_code = error;
656 	sbi->s_last_error_line = line;
657 	sbi->s_last_error_ino = ino;
658 	sbi->s_last_error_block = block;
659 	sbi->s_last_error_func = func;
660 	sbi->s_last_error_time = ktime_get_real_seconds();
661 	if (!sbi->s_first_error_time) {
662 		sbi->s_first_error_code = error;
663 		sbi->s_first_error_line = line;
664 		sbi->s_first_error_ino = ino;
665 		sbi->s_first_error_block = block;
666 		sbi->s_first_error_func = func;
667 		sbi->s_first_error_time = sbi->s_last_error_time;
668 	}
669 	spin_unlock(&sbi->s_error_lock);
670 }
671 
672 /* Deal with the reporting of failure conditions on a filesystem such as
673  * inconsistencies detected or read IO failures.
674  *
675  * On ext2, we can store the error state of the filesystem in the
676  * superblock.  That is not possible on ext4, because we may have other
677  * write ordering constraints on the superblock which prevent us from
678  * writing it out straight away; and given that the journal is about to
679  * be aborted, we can't rely on the current, or future, transactions to
680  * write out the superblock safely.
681  *
682  * We'll just use the jbd2_journal_abort() error code to record an error in
683  * the journal instead.  On recovery, the journal will complain about
684  * that error until we've noted it down and cleared it.
685  *
686  * If force_ro is set, we unconditionally force the filesystem into an
687  * ABORT|READONLY state, unless the error response on the fs has been set to
688  * panic in which case we take the easy way out and panic immediately. This is
689  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
690  * at a critical moment in log management.
691  */
692 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
693 			      __u32 ino, __u64 block,
694 			      const char *func, unsigned int line)
695 {
696 	journal_t *journal = EXT4_SB(sb)->s_journal;
697 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
698 
699 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
700 	if (test_opt(sb, WARN_ON_ERROR))
701 		WARN_ON_ONCE(1);
702 
703 	if (!continue_fs && !sb_rdonly(sb)) {
704 		set_bit(EXT4_FLAGS_SHUTDOWN, &EXT4_SB(sb)->s_ext4_flags);
705 		if (journal)
706 			jbd2_journal_abort(journal, -EIO);
707 	}
708 
709 	if (!bdev_read_only(sb->s_bdev)) {
710 		save_error_info(sb, error, ino, block, func, line);
711 		/*
712 		 * In case the fs should keep running, we need to writeout
713 		 * superblock through the journal. Due to lock ordering
714 		 * constraints, it may not be safe to do it right here so we
715 		 * defer superblock flushing to a workqueue.
716 		 */
717 		if (continue_fs && journal)
718 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
719 		else
720 			ext4_commit_super(sb);
721 	}
722 
723 	/*
724 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
725 	 * could panic during 'reboot -f' as the underlying device got already
726 	 * disabled.
727 	 */
728 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
729 		panic("EXT4-fs (device %s): panic forced after error\n",
730 			sb->s_id);
731 	}
732 
733 	if (sb_rdonly(sb) || continue_fs)
734 		return;
735 
736 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
737 	/*
738 	 * Make sure updated value of ->s_mount_flags will be visible before
739 	 * ->s_flags update
740 	 */
741 	smp_wmb();
742 	sb->s_flags |= SB_RDONLY;
743 }
744 
745 static void update_super_work(struct work_struct *work)
746 {
747 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
748 						s_sb_upd_work);
749 	journal_t *journal = sbi->s_journal;
750 	handle_t *handle;
751 
752 	/*
753 	 * If the journal is still running, we have to write out superblock
754 	 * through the journal to avoid collisions of other journalled sb
755 	 * updates.
756 	 *
757 	 * We use directly jbd2 functions here to avoid recursing back into
758 	 * ext4 error handling code during handling of previous errors.
759 	 */
760 	if (!sb_rdonly(sbi->s_sb) && journal) {
761 		struct buffer_head *sbh = sbi->s_sbh;
762 		bool call_notify_err = false;
763 
764 		handle = jbd2_journal_start(journal, 1);
765 		if (IS_ERR(handle))
766 			goto write_directly;
767 		if (jbd2_journal_get_write_access(handle, sbh)) {
768 			jbd2_journal_stop(handle);
769 			goto write_directly;
770 		}
771 
772 		if (sbi->s_add_error_count > 0)
773 			call_notify_err = true;
774 
775 		ext4_update_super(sbi->s_sb);
776 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
777 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
778 				 "superblock detected");
779 			clear_buffer_write_io_error(sbh);
780 			set_buffer_uptodate(sbh);
781 		}
782 
783 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
784 			jbd2_journal_stop(handle);
785 			goto write_directly;
786 		}
787 		jbd2_journal_stop(handle);
788 
789 		if (call_notify_err)
790 			ext4_notify_error_sysfs(sbi);
791 
792 		return;
793 	}
794 write_directly:
795 	/*
796 	 * Write through journal failed. Write sb directly to get error info
797 	 * out and hope for the best.
798 	 */
799 	ext4_commit_super(sbi->s_sb);
800 	ext4_notify_error_sysfs(sbi);
801 }
802 
803 #define ext4_error_ratelimit(sb)					\
804 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
805 			     "EXT4-fs error")
806 
807 void __ext4_error(struct super_block *sb, const char *function,
808 		  unsigned int line, bool force_ro, int error, __u64 block,
809 		  const char *fmt, ...)
810 {
811 	struct va_format vaf;
812 	va_list args;
813 
814 	if (unlikely(ext4_forced_shutdown(sb)))
815 		return;
816 
817 	trace_ext4_error(sb, function, line);
818 	if (ext4_error_ratelimit(sb)) {
819 		va_start(args, fmt);
820 		vaf.fmt = fmt;
821 		vaf.va = &args;
822 		printk(KERN_CRIT
823 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
824 		       sb->s_id, function, line, current->comm, &vaf);
825 		va_end(args);
826 	}
827 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
828 
829 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
830 }
831 
832 void __ext4_error_inode(struct inode *inode, const char *function,
833 			unsigned int line, ext4_fsblk_t block, int error,
834 			const char *fmt, ...)
835 {
836 	va_list args;
837 	struct va_format vaf;
838 
839 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
840 		return;
841 
842 	trace_ext4_error(inode->i_sb, function, line);
843 	if (ext4_error_ratelimit(inode->i_sb)) {
844 		va_start(args, fmt);
845 		vaf.fmt = fmt;
846 		vaf.va = &args;
847 		if (block)
848 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
849 			       "inode #%lu: block %llu: comm %s: %pV\n",
850 			       inode->i_sb->s_id, function, line, inode->i_ino,
851 			       block, current->comm, &vaf);
852 		else
853 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
854 			       "inode #%lu: comm %s: %pV\n",
855 			       inode->i_sb->s_id, function, line, inode->i_ino,
856 			       current->comm, &vaf);
857 		va_end(args);
858 	}
859 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
860 
861 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
862 			  function, line);
863 }
864 
865 void __ext4_error_file(struct file *file, const char *function,
866 		       unsigned int line, ext4_fsblk_t block,
867 		       const char *fmt, ...)
868 {
869 	va_list args;
870 	struct va_format vaf;
871 	struct inode *inode = file_inode(file);
872 	char pathname[80], *path;
873 
874 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
875 		return;
876 
877 	trace_ext4_error(inode->i_sb, function, line);
878 	if (ext4_error_ratelimit(inode->i_sb)) {
879 		path = file_path(file, pathname, sizeof(pathname));
880 		if (IS_ERR(path))
881 			path = "(unknown)";
882 		va_start(args, fmt);
883 		vaf.fmt = fmt;
884 		vaf.va = &args;
885 		if (block)
886 			printk(KERN_CRIT
887 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
888 			       "block %llu: comm %s: path %s: %pV\n",
889 			       inode->i_sb->s_id, function, line, inode->i_ino,
890 			       block, current->comm, path, &vaf);
891 		else
892 			printk(KERN_CRIT
893 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
894 			       "comm %s: path %s: %pV\n",
895 			       inode->i_sb->s_id, function, line, inode->i_ino,
896 			       current->comm, path, &vaf);
897 		va_end(args);
898 	}
899 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
900 
901 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
902 			  function, line);
903 }
904 
905 const char *ext4_decode_error(struct super_block *sb, int errno,
906 			      char nbuf[16])
907 {
908 	char *errstr = NULL;
909 
910 	switch (errno) {
911 	case -EFSCORRUPTED:
912 		errstr = "Corrupt filesystem";
913 		break;
914 	case -EFSBADCRC:
915 		errstr = "Filesystem failed CRC";
916 		break;
917 	case -EIO:
918 		errstr = "IO failure";
919 		break;
920 	case -ENOMEM:
921 		errstr = "Out of memory";
922 		break;
923 	case -EROFS:
924 		if (!sb || (EXT4_SB(sb)->s_journal &&
925 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
926 			errstr = "Journal has aborted";
927 		else
928 			errstr = "Readonly filesystem";
929 		break;
930 	default:
931 		/* If the caller passed in an extra buffer for unknown
932 		 * errors, textualise them now.  Else we just return
933 		 * NULL. */
934 		if (nbuf) {
935 			/* Check for truncated error codes... */
936 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
937 				errstr = nbuf;
938 		}
939 		break;
940 	}
941 
942 	return errstr;
943 }
944 
945 /* __ext4_std_error decodes expected errors from journaling functions
946  * automatically and invokes the appropriate error response.  */
947 
948 void __ext4_std_error(struct super_block *sb, const char *function,
949 		      unsigned int line, int errno)
950 {
951 	char nbuf[16];
952 	const char *errstr;
953 
954 	if (unlikely(ext4_forced_shutdown(sb)))
955 		return;
956 
957 	/* Special case: if the error is EROFS, and we're not already
958 	 * inside a transaction, then there's really no point in logging
959 	 * an error. */
960 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
961 		return;
962 
963 	if (ext4_error_ratelimit(sb)) {
964 		errstr = ext4_decode_error(sb, errno, nbuf);
965 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
966 		       sb->s_id, function, line, errstr);
967 	}
968 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
969 
970 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
971 }
972 
973 void __ext4_msg(struct super_block *sb,
974 		const char *prefix, const char *fmt, ...)
975 {
976 	struct va_format vaf;
977 	va_list args;
978 
979 	if (sb) {
980 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
981 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
982 				  "EXT4-fs"))
983 			return;
984 	}
985 
986 	va_start(args, fmt);
987 	vaf.fmt = fmt;
988 	vaf.va = &args;
989 	if (sb)
990 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
991 	else
992 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
993 	va_end(args);
994 }
995 
996 static int ext4_warning_ratelimit(struct super_block *sb)
997 {
998 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
999 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1000 			    "EXT4-fs warning");
1001 }
1002 
1003 void __ext4_warning(struct super_block *sb, const char *function,
1004 		    unsigned int line, const char *fmt, ...)
1005 {
1006 	struct va_format vaf;
1007 	va_list args;
1008 
1009 	if (!ext4_warning_ratelimit(sb))
1010 		return;
1011 
1012 	va_start(args, fmt);
1013 	vaf.fmt = fmt;
1014 	vaf.va = &args;
1015 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1016 	       sb->s_id, function, line, &vaf);
1017 	va_end(args);
1018 }
1019 
1020 void __ext4_warning_inode(const struct inode *inode, const char *function,
1021 			  unsigned int line, const char *fmt, ...)
1022 {
1023 	struct va_format vaf;
1024 	va_list args;
1025 
1026 	if (!ext4_warning_ratelimit(inode->i_sb))
1027 		return;
1028 
1029 	va_start(args, fmt);
1030 	vaf.fmt = fmt;
1031 	vaf.va = &args;
1032 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1033 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
1034 	       function, line, inode->i_ino, current->comm, &vaf);
1035 	va_end(args);
1036 }
1037 
1038 void __ext4_grp_locked_error(const char *function, unsigned int line,
1039 			     struct super_block *sb, ext4_group_t grp,
1040 			     unsigned long ino, ext4_fsblk_t block,
1041 			     const char *fmt, ...)
1042 __releases(bitlock)
1043 __acquires(bitlock)
1044 {
1045 	struct va_format vaf;
1046 	va_list args;
1047 
1048 	if (unlikely(ext4_forced_shutdown(sb)))
1049 		return;
1050 
1051 	trace_ext4_error(sb, function, line);
1052 	if (ext4_error_ratelimit(sb)) {
1053 		va_start(args, fmt);
1054 		vaf.fmt = fmt;
1055 		vaf.va = &args;
1056 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1057 		       sb->s_id, function, line, grp);
1058 		if (ino)
1059 			printk(KERN_CONT "inode %lu: ", ino);
1060 		if (block)
1061 			printk(KERN_CONT "block %llu:",
1062 			       (unsigned long long) block);
1063 		printk(KERN_CONT "%pV\n", &vaf);
1064 		va_end(args);
1065 	}
1066 
1067 	if (test_opt(sb, ERRORS_CONT)) {
1068 		if (test_opt(sb, WARN_ON_ERROR))
1069 			WARN_ON_ONCE(1);
1070 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1071 		if (!bdev_read_only(sb->s_bdev)) {
1072 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1073 					line);
1074 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1075 		}
1076 		return;
1077 	}
1078 	ext4_unlock_group(sb, grp);
1079 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1080 	/*
1081 	 * We only get here in the ERRORS_RO case; relocking the group
1082 	 * may be dangerous, but nothing bad will happen since the
1083 	 * filesystem will have already been marked read/only and the
1084 	 * journal has been aborted.  We return 1 as a hint to callers
1085 	 * who might what to use the return value from
1086 	 * ext4_grp_locked_error() to distinguish between the
1087 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1088 	 * aggressively from the ext4 function in question, with a
1089 	 * more appropriate error code.
1090 	 */
1091 	ext4_lock_group(sb, grp);
1092 	return;
1093 }
1094 
1095 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1096 				     ext4_group_t group,
1097 				     unsigned int flags)
1098 {
1099 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1100 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1101 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1102 	int ret;
1103 
1104 	if (!grp || !gdp)
1105 		return;
1106 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1107 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1108 					    &grp->bb_state);
1109 		if (!ret)
1110 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1111 					   grp->bb_free);
1112 	}
1113 
1114 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1115 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1116 					    &grp->bb_state);
1117 		if (!ret && gdp) {
1118 			int count;
1119 
1120 			count = ext4_free_inodes_count(sb, gdp);
1121 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1122 					   count);
1123 		}
1124 	}
1125 }
1126 
1127 void ext4_update_dynamic_rev(struct super_block *sb)
1128 {
1129 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1130 
1131 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1132 		return;
1133 
1134 	ext4_warning(sb,
1135 		     "updating to rev %d because of new feature flag, "
1136 		     "running e2fsck is recommended",
1137 		     EXT4_DYNAMIC_REV);
1138 
1139 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1140 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1141 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1142 	/* leave es->s_feature_*compat flags alone */
1143 	/* es->s_uuid will be set by e2fsck if empty */
1144 
1145 	/*
1146 	 * The rest of the superblock fields should be zero, and if not it
1147 	 * means they are likely already in use, so leave them alone.  We
1148 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1149 	 */
1150 }
1151 
1152 static inline struct inode *orphan_list_entry(struct list_head *l)
1153 {
1154 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1155 }
1156 
1157 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1158 {
1159 	struct list_head *l;
1160 
1161 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1162 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1163 
1164 	printk(KERN_ERR "sb_info orphan list:\n");
1165 	list_for_each(l, &sbi->s_orphan) {
1166 		struct inode *inode = orphan_list_entry(l);
1167 		printk(KERN_ERR "  "
1168 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1169 		       inode->i_sb->s_id, inode->i_ino, inode,
1170 		       inode->i_mode, inode->i_nlink,
1171 		       NEXT_ORPHAN(inode));
1172 	}
1173 }
1174 
1175 #ifdef CONFIG_QUOTA
1176 static int ext4_quota_off(struct super_block *sb, int type);
1177 
1178 static inline void ext4_quotas_off(struct super_block *sb, int type)
1179 {
1180 	BUG_ON(type > EXT4_MAXQUOTAS);
1181 
1182 	/* Use our quota_off function to clear inode flags etc. */
1183 	for (type--; type >= 0; type--)
1184 		ext4_quota_off(sb, type);
1185 }
1186 
1187 /*
1188  * This is a helper function which is used in the mount/remount
1189  * codepaths (which holds s_umount) to fetch the quota file name.
1190  */
1191 static inline char *get_qf_name(struct super_block *sb,
1192 				struct ext4_sb_info *sbi,
1193 				int type)
1194 {
1195 	return rcu_dereference_protected(sbi->s_qf_names[type],
1196 					 lockdep_is_held(&sb->s_umount));
1197 }
1198 #else
1199 static inline void ext4_quotas_off(struct super_block *sb, int type)
1200 {
1201 }
1202 #endif
1203 
1204 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1205 {
1206 	ext4_fsblk_t block;
1207 	int err;
1208 
1209 	block = ext4_count_free_clusters(sbi->s_sb);
1210 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1211 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1212 				  GFP_KERNEL);
1213 	if (!err) {
1214 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1215 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1216 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1217 					  GFP_KERNEL);
1218 	}
1219 	if (!err)
1220 		err = percpu_counter_init(&sbi->s_dirs_counter,
1221 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1222 	if (!err)
1223 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1224 					  GFP_KERNEL);
1225 	if (!err)
1226 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1227 					  GFP_KERNEL);
1228 	if (!err)
1229 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1230 
1231 	if (err)
1232 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1233 
1234 	return err;
1235 }
1236 
1237 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1238 {
1239 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1240 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1241 	percpu_counter_destroy(&sbi->s_dirs_counter);
1242 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1243 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1244 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1245 }
1246 
1247 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1248 {
1249 	struct buffer_head **group_desc;
1250 	int i;
1251 
1252 	rcu_read_lock();
1253 	group_desc = rcu_dereference(sbi->s_group_desc);
1254 	for (i = 0; i < sbi->s_gdb_count; i++)
1255 		brelse(group_desc[i]);
1256 	kvfree(group_desc);
1257 	rcu_read_unlock();
1258 }
1259 
1260 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1261 {
1262 	struct flex_groups **flex_groups;
1263 	int i;
1264 
1265 	rcu_read_lock();
1266 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1267 	if (flex_groups) {
1268 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1269 			kvfree(flex_groups[i]);
1270 		kvfree(flex_groups);
1271 	}
1272 	rcu_read_unlock();
1273 }
1274 
1275 static void ext4_put_super(struct super_block *sb)
1276 {
1277 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1278 	struct ext4_super_block *es = sbi->s_es;
1279 	int aborted = 0;
1280 	int err;
1281 
1282 	/*
1283 	 * Unregister sysfs before destroying jbd2 journal.
1284 	 * Since we could still access attr_journal_task attribute via sysfs
1285 	 * path which could have sbi->s_journal->j_task as NULL
1286 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1287 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1288 	 * read metadata verify failed then will queue error work.
1289 	 * update_super_work will call start_this_handle may trigger
1290 	 * BUG_ON.
1291 	 */
1292 	ext4_unregister_sysfs(sb);
1293 
1294 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1295 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1296 			 &sb->s_uuid);
1297 
1298 	ext4_unregister_li_request(sb);
1299 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1300 
1301 	flush_work(&sbi->s_sb_upd_work);
1302 	destroy_workqueue(sbi->rsv_conversion_wq);
1303 	ext4_release_orphan_info(sb);
1304 
1305 	if (sbi->s_journal) {
1306 		aborted = is_journal_aborted(sbi->s_journal);
1307 		err = jbd2_journal_destroy(sbi->s_journal);
1308 		sbi->s_journal = NULL;
1309 		if ((err < 0) && !aborted) {
1310 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1311 		}
1312 	}
1313 
1314 	ext4_es_unregister_shrinker(sbi);
1315 	timer_shutdown_sync(&sbi->s_err_report);
1316 	ext4_release_system_zone(sb);
1317 	ext4_mb_release(sb);
1318 	ext4_ext_release(sb);
1319 
1320 	if (!sb_rdonly(sb) && !aborted) {
1321 		ext4_clear_feature_journal_needs_recovery(sb);
1322 		ext4_clear_feature_orphan_present(sb);
1323 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1324 	}
1325 	if (!sb_rdonly(sb))
1326 		ext4_commit_super(sb);
1327 
1328 	ext4_group_desc_free(sbi);
1329 	ext4_flex_groups_free(sbi);
1330 
1331 	WARN_ON_ONCE(!(sbi->s_mount_state & EXT4_ERROR_FS) &&
1332 		     percpu_counter_sum(&sbi->s_dirtyclusters_counter));
1333 	ext4_percpu_param_destroy(sbi);
1334 #ifdef CONFIG_QUOTA
1335 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1336 		kfree(get_qf_name(sb, sbi, i));
1337 #endif
1338 
1339 	/* Debugging code just in case the in-memory inode orphan list
1340 	 * isn't empty.  The on-disk one can be non-empty if we've
1341 	 * detected an error and taken the fs readonly, but the
1342 	 * in-memory list had better be clean by this point. */
1343 	if (!list_empty(&sbi->s_orphan))
1344 		dump_orphan_list(sb, sbi);
1345 	ASSERT(list_empty(&sbi->s_orphan));
1346 
1347 	sync_blockdev(sb->s_bdev);
1348 	invalidate_bdev(sb->s_bdev);
1349 	if (sbi->s_journal_bdev_file) {
1350 		/*
1351 		 * Invalidate the journal device's buffers.  We don't want them
1352 		 * floating about in memory - the physical journal device may
1353 		 * hotswapped, and it breaks the `ro-after' testing code.
1354 		 */
1355 		sync_blockdev(file_bdev(sbi->s_journal_bdev_file));
1356 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
1357 	}
1358 
1359 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1360 	sbi->s_ea_inode_cache = NULL;
1361 
1362 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1363 	sbi->s_ea_block_cache = NULL;
1364 
1365 	ext4_stop_mmpd(sbi);
1366 
1367 	brelse(sbi->s_sbh);
1368 	sb->s_fs_info = NULL;
1369 	/*
1370 	 * Now that we are completely done shutting down the
1371 	 * superblock, we need to actually destroy the kobject.
1372 	 */
1373 	kobject_put(&sbi->s_kobj);
1374 	wait_for_completion(&sbi->s_kobj_unregister);
1375 	if (sbi->s_chksum_driver)
1376 		crypto_free_shash(sbi->s_chksum_driver);
1377 	kfree(sbi->s_blockgroup_lock);
1378 	fs_put_dax(sbi->s_daxdev, NULL);
1379 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1380 #if IS_ENABLED(CONFIG_UNICODE)
1381 	utf8_unload(sb->s_encoding);
1382 #endif
1383 	kfree(sbi);
1384 }
1385 
1386 static struct kmem_cache *ext4_inode_cachep;
1387 
1388 /*
1389  * Called inside transaction, so use GFP_NOFS
1390  */
1391 static struct inode *ext4_alloc_inode(struct super_block *sb)
1392 {
1393 	struct ext4_inode_info *ei;
1394 
1395 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1396 	if (!ei)
1397 		return NULL;
1398 
1399 	inode_set_iversion(&ei->vfs_inode, 1);
1400 	ei->i_flags = 0;
1401 	spin_lock_init(&ei->i_raw_lock);
1402 	ei->i_prealloc_node = RB_ROOT;
1403 	atomic_set(&ei->i_prealloc_active, 0);
1404 	rwlock_init(&ei->i_prealloc_lock);
1405 	ext4_es_init_tree(&ei->i_es_tree);
1406 	rwlock_init(&ei->i_es_lock);
1407 	INIT_LIST_HEAD(&ei->i_es_list);
1408 	ei->i_es_all_nr = 0;
1409 	ei->i_es_shk_nr = 0;
1410 	ei->i_es_shrink_lblk = 0;
1411 	ei->i_reserved_data_blocks = 0;
1412 	spin_lock_init(&(ei->i_block_reservation_lock));
1413 	ext4_init_pending_tree(&ei->i_pending_tree);
1414 #ifdef CONFIG_QUOTA
1415 	ei->i_reserved_quota = 0;
1416 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1417 #endif
1418 	ei->jinode = NULL;
1419 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1420 	spin_lock_init(&ei->i_completed_io_lock);
1421 	ei->i_sync_tid = 0;
1422 	ei->i_datasync_tid = 0;
1423 	atomic_set(&ei->i_unwritten, 0);
1424 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1425 	ext4_fc_init_inode(&ei->vfs_inode);
1426 	mutex_init(&ei->i_fc_lock);
1427 	return &ei->vfs_inode;
1428 }
1429 
1430 static int ext4_drop_inode(struct inode *inode)
1431 {
1432 	int drop = generic_drop_inode(inode);
1433 
1434 	if (!drop)
1435 		drop = fscrypt_drop_inode(inode);
1436 
1437 	trace_ext4_drop_inode(inode, drop);
1438 	return drop;
1439 }
1440 
1441 static void ext4_free_in_core_inode(struct inode *inode)
1442 {
1443 	fscrypt_free_inode(inode);
1444 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1445 		pr_warn("%s: inode %ld still in fc list",
1446 			__func__, inode->i_ino);
1447 	}
1448 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1449 }
1450 
1451 static void ext4_destroy_inode(struct inode *inode)
1452 {
1453 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1454 		ext4_msg(inode->i_sb, KERN_ERR,
1455 			 "Inode %lu (%p): orphan list check failed!",
1456 			 inode->i_ino, EXT4_I(inode));
1457 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1458 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1459 				true);
1460 		dump_stack();
1461 	}
1462 
1463 	if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
1464 	    WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
1465 		ext4_msg(inode->i_sb, KERN_ERR,
1466 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1467 			 inode->i_ino, EXT4_I(inode),
1468 			 EXT4_I(inode)->i_reserved_data_blocks);
1469 }
1470 
1471 static void ext4_shutdown(struct super_block *sb)
1472 {
1473        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1474 }
1475 
1476 static void init_once(void *foo)
1477 {
1478 	struct ext4_inode_info *ei = foo;
1479 
1480 	INIT_LIST_HEAD(&ei->i_orphan);
1481 	init_rwsem(&ei->xattr_sem);
1482 	init_rwsem(&ei->i_data_sem);
1483 	inode_init_once(&ei->vfs_inode);
1484 	ext4_fc_init_inode(&ei->vfs_inode);
1485 }
1486 
1487 static int __init init_inodecache(void)
1488 {
1489 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1490 				sizeof(struct ext4_inode_info), 0,
1491 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
1492 				offsetof(struct ext4_inode_info, i_data),
1493 				sizeof_field(struct ext4_inode_info, i_data),
1494 				init_once);
1495 	if (ext4_inode_cachep == NULL)
1496 		return -ENOMEM;
1497 	return 0;
1498 }
1499 
1500 static void destroy_inodecache(void)
1501 {
1502 	/*
1503 	 * Make sure all delayed rcu free inodes are flushed before we
1504 	 * destroy cache.
1505 	 */
1506 	rcu_barrier();
1507 	kmem_cache_destroy(ext4_inode_cachep);
1508 }
1509 
1510 void ext4_clear_inode(struct inode *inode)
1511 {
1512 	ext4_fc_del(inode);
1513 	invalidate_inode_buffers(inode);
1514 	clear_inode(inode);
1515 	ext4_discard_preallocations(inode);
1516 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1517 	dquot_drop(inode);
1518 	if (EXT4_I(inode)->jinode) {
1519 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1520 					       EXT4_I(inode)->jinode);
1521 		jbd2_free_inode(EXT4_I(inode)->jinode);
1522 		EXT4_I(inode)->jinode = NULL;
1523 	}
1524 	fscrypt_put_encryption_info(inode);
1525 	fsverity_cleanup_inode(inode);
1526 }
1527 
1528 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1529 					u64 ino, u32 generation)
1530 {
1531 	struct inode *inode;
1532 
1533 	/*
1534 	 * Currently we don't know the generation for parent directory, so
1535 	 * a generation of 0 means "accept any"
1536 	 */
1537 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1538 	if (IS_ERR(inode))
1539 		return ERR_CAST(inode);
1540 	if (generation && inode->i_generation != generation) {
1541 		iput(inode);
1542 		return ERR_PTR(-ESTALE);
1543 	}
1544 
1545 	return inode;
1546 }
1547 
1548 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1549 					int fh_len, int fh_type)
1550 {
1551 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1552 				    ext4_nfs_get_inode);
1553 }
1554 
1555 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1556 					int fh_len, int fh_type)
1557 {
1558 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1559 				    ext4_nfs_get_inode);
1560 }
1561 
1562 static int ext4_nfs_commit_metadata(struct inode *inode)
1563 {
1564 	struct writeback_control wbc = {
1565 		.sync_mode = WB_SYNC_ALL
1566 	};
1567 
1568 	trace_ext4_nfs_commit_metadata(inode);
1569 	return ext4_write_inode(inode, &wbc);
1570 }
1571 
1572 #ifdef CONFIG_QUOTA
1573 static const char * const quotatypes[] = INITQFNAMES;
1574 #define QTYPE2NAME(t) (quotatypes[t])
1575 
1576 static int ext4_write_dquot(struct dquot *dquot);
1577 static int ext4_acquire_dquot(struct dquot *dquot);
1578 static int ext4_release_dquot(struct dquot *dquot);
1579 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1580 static int ext4_write_info(struct super_block *sb, int type);
1581 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1582 			 const struct path *path);
1583 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1584 			       size_t len, loff_t off);
1585 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1586 				const char *data, size_t len, loff_t off);
1587 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1588 			     unsigned int flags);
1589 
1590 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1591 {
1592 	return EXT4_I(inode)->i_dquot;
1593 }
1594 
1595 static const struct dquot_operations ext4_quota_operations = {
1596 	.get_reserved_space	= ext4_get_reserved_space,
1597 	.write_dquot		= ext4_write_dquot,
1598 	.acquire_dquot		= ext4_acquire_dquot,
1599 	.release_dquot		= ext4_release_dquot,
1600 	.mark_dirty		= ext4_mark_dquot_dirty,
1601 	.write_info		= ext4_write_info,
1602 	.alloc_dquot		= dquot_alloc,
1603 	.destroy_dquot		= dquot_destroy,
1604 	.get_projid		= ext4_get_projid,
1605 	.get_inode_usage	= ext4_get_inode_usage,
1606 	.get_next_id		= dquot_get_next_id,
1607 };
1608 
1609 static const struct quotactl_ops ext4_qctl_operations = {
1610 	.quota_on	= ext4_quota_on,
1611 	.quota_off	= ext4_quota_off,
1612 	.quota_sync	= dquot_quota_sync,
1613 	.get_state	= dquot_get_state,
1614 	.set_info	= dquot_set_dqinfo,
1615 	.get_dqblk	= dquot_get_dqblk,
1616 	.set_dqblk	= dquot_set_dqblk,
1617 	.get_nextdqblk	= dquot_get_next_dqblk,
1618 };
1619 #endif
1620 
1621 static const struct super_operations ext4_sops = {
1622 	.alloc_inode	= ext4_alloc_inode,
1623 	.free_inode	= ext4_free_in_core_inode,
1624 	.destroy_inode	= ext4_destroy_inode,
1625 	.write_inode	= ext4_write_inode,
1626 	.dirty_inode	= ext4_dirty_inode,
1627 	.drop_inode	= ext4_drop_inode,
1628 	.evict_inode	= ext4_evict_inode,
1629 	.put_super	= ext4_put_super,
1630 	.sync_fs	= ext4_sync_fs,
1631 	.freeze_fs	= ext4_freeze,
1632 	.unfreeze_fs	= ext4_unfreeze,
1633 	.statfs		= ext4_statfs,
1634 	.show_options	= ext4_show_options,
1635 	.shutdown	= ext4_shutdown,
1636 #ifdef CONFIG_QUOTA
1637 	.quota_read	= ext4_quota_read,
1638 	.quota_write	= ext4_quota_write,
1639 	.get_dquots	= ext4_get_dquots,
1640 #endif
1641 };
1642 
1643 static const struct export_operations ext4_export_ops = {
1644 	.encode_fh = generic_encode_ino32_fh,
1645 	.fh_to_dentry = ext4_fh_to_dentry,
1646 	.fh_to_parent = ext4_fh_to_parent,
1647 	.get_parent = ext4_get_parent,
1648 	.commit_metadata = ext4_nfs_commit_metadata,
1649 };
1650 
1651 enum {
1652 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1653 	Opt_resgid, Opt_resuid, Opt_sb,
1654 	Opt_nouid32, Opt_debug, Opt_removed,
1655 	Opt_user_xattr, Opt_acl,
1656 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1657 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1658 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1659 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1660 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1661 	Opt_inlinecrypt,
1662 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1663 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1664 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1665 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1666 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1667 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1668 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1669 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1670 	Opt_dioread_nolock, Opt_dioread_lock,
1671 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1672 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1673 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1674 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1675 #ifdef CONFIG_EXT4_DEBUG
1676 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1677 #endif
1678 };
1679 
1680 static const struct constant_table ext4_param_errors[] = {
1681 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1682 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1683 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1684 	{}
1685 };
1686 
1687 static const struct constant_table ext4_param_data[] = {
1688 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1689 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1690 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1691 	{}
1692 };
1693 
1694 static const struct constant_table ext4_param_data_err[] = {
1695 	{"abort",	Opt_data_err_abort},
1696 	{"ignore",	Opt_data_err_ignore},
1697 	{}
1698 };
1699 
1700 static const struct constant_table ext4_param_jqfmt[] = {
1701 	{"vfsold",	QFMT_VFS_OLD},
1702 	{"vfsv0",	QFMT_VFS_V0},
1703 	{"vfsv1",	QFMT_VFS_V1},
1704 	{}
1705 };
1706 
1707 static const struct constant_table ext4_param_dax[] = {
1708 	{"always",	Opt_dax_always},
1709 	{"inode",	Opt_dax_inode},
1710 	{"never",	Opt_dax_never},
1711 	{}
1712 };
1713 
1714 /*
1715  * Mount option specification
1716  * We don't use fsparam_flag_no because of the way we set the
1717  * options and the way we show them in _ext4_show_options(). To
1718  * keep the changes to a minimum, let's keep the negative options
1719  * separate for now.
1720  */
1721 static const struct fs_parameter_spec ext4_param_specs[] = {
1722 	fsparam_flag	("bsddf",		Opt_bsd_df),
1723 	fsparam_flag	("minixdf",		Opt_minix_df),
1724 	fsparam_flag	("grpid",		Opt_grpid),
1725 	fsparam_flag	("bsdgroups",		Opt_grpid),
1726 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1727 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1728 	fsparam_gid	("resgid",		Opt_resgid),
1729 	fsparam_uid	("resuid",		Opt_resuid),
1730 	fsparam_u32	("sb",			Opt_sb),
1731 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1732 	fsparam_flag	("nouid32",		Opt_nouid32),
1733 	fsparam_flag	("debug",		Opt_debug),
1734 	fsparam_flag	("oldalloc",		Opt_removed),
1735 	fsparam_flag	("orlov",		Opt_removed),
1736 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1737 	fsparam_flag	("acl",			Opt_acl),
1738 	fsparam_flag	("norecovery",		Opt_noload),
1739 	fsparam_flag	("noload",		Opt_noload),
1740 	fsparam_flag	("bh",			Opt_removed),
1741 	fsparam_flag	("nobh",		Opt_removed),
1742 	fsparam_u32	("commit",		Opt_commit),
1743 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1744 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1745 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1746 	fsparam_bdev	("journal_path",	Opt_journal_path),
1747 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1748 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1749 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1750 	fsparam_flag	("abort",		Opt_abort),
1751 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1752 	fsparam_enum	("data_err",		Opt_data_err,
1753 						ext4_param_data_err),
1754 	fsparam_string_empty
1755 			("usrjquota",		Opt_usrjquota),
1756 	fsparam_string_empty
1757 			("grpjquota",		Opt_grpjquota),
1758 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1759 	fsparam_flag	("grpquota",		Opt_grpquota),
1760 	fsparam_flag	("quota",		Opt_quota),
1761 	fsparam_flag	("noquota",		Opt_noquota),
1762 	fsparam_flag	("usrquota",		Opt_usrquota),
1763 	fsparam_flag	("prjquota",		Opt_prjquota),
1764 	fsparam_flag	("barrier",		Opt_barrier),
1765 	fsparam_u32	("barrier",		Opt_barrier),
1766 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1767 	fsparam_flag	("i_version",		Opt_removed),
1768 	fsparam_flag	("dax",			Opt_dax),
1769 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1770 	fsparam_u32	("stripe",		Opt_stripe),
1771 	fsparam_flag	("delalloc",		Opt_delalloc),
1772 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1773 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1774 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1775 	fsparam_u32	("debug_want_extra_isize",
1776 						Opt_debug_want_extra_isize),
1777 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1778 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1779 	fsparam_flag	("block_validity",	Opt_block_validity),
1780 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1781 	fsparam_u32	("inode_readahead_blks",
1782 						Opt_inode_readahead_blks),
1783 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1784 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1785 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1786 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1787 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1788 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1789 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1790 	fsparam_flag	("discard",		Opt_discard),
1791 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1792 	fsparam_u32	("init_itable",		Opt_init_itable),
1793 	fsparam_flag	("init_itable",		Opt_init_itable),
1794 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1795 #ifdef CONFIG_EXT4_DEBUG
1796 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1797 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1798 #endif
1799 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1800 	fsparam_flag	("test_dummy_encryption",
1801 						Opt_test_dummy_encryption),
1802 	fsparam_string	("test_dummy_encryption",
1803 						Opt_test_dummy_encryption),
1804 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1805 	fsparam_flag	("nombcache",		Opt_nombcache),
1806 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1807 	fsparam_flag	("prefetch_block_bitmaps",
1808 						Opt_removed),
1809 	fsparam_flag	("no_prefetch_block_bitmaps",
1810 						Opt_no_prefetch_block_bitmaps),
1811 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1812 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1813 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1814 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1815 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1816 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1817 	{}
1818 };
1819 
1820 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1821 
1822 #define MOPT_SET	0x0001
1823 #define MOPT_CLEAR	0x0002
1824 #define MOPT_NOSUPPORT	0x0004
1825 #define MOPT_EXPLICIT	0x0008
1826 #ifdef CONFIG_QUOTA
1827 #define MOPT_Q		0
1828 #define MOPT_QFMT	0x0010
1829 #else
1830 #define MOPT_Q		MOPT_NOSUPPORT
1831 #define MOPT_QFMT	MOPT_NOSUPPORT
1832 #endif
1833 #define MOPT_NO_EXT2	0x0020
1834 #define MOPT_NO_EXT3	0x0040
1835 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1836 #define MOPT_SKIP	0x0080
1837 #define	MOPT_2		0x0100
1838 
1839 static const struct mount_opts {
1840 	int	token;
1841 	int	mount_opt;
1842 	int	flags;
1843 } ext4_mount_opts[] = {
1844 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1845 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1846 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1847 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1848 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1849 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1850 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1851 	 MOPT_EXT4_ONLY | MOPT_SET},
1852 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1853 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1854 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1855 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1856 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1857 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1858 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1859 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1860 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1861 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1862 	{Opt_commit, 0, MOPT_NO_EXT2},
1863 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1864 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1865 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1866 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1867 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1868 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1869 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1870 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1871 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1872 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1873 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1874 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1875 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1876 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1877 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1878 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1879 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1880 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1881 	{Opt_data, 0, MOPT_NO_EXT2},
1882 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1883 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1884 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1885 #else
1886 	{Opt_acl, 0, MOPT_NOSUPPORT},
1887 #endif
1888 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1889 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1890 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1891 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1892 							MOPT_SET | MOPT_Q},
1893 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1894 							MOPT_SET | MOPT_Q},
1895 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1896 							MOPT_SET | MOPT_Q},
1897 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1898 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1899 							MOPT_CLEAR | MOPT_Q},
1900 	{Opt_usrjquota, 0, MOPT_Q},
1901 	{Opt_grpjquota, 0, MOPT_Q},
1902 	{Opt_jqfmt, 0, MOPT_QFMT},
1903 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1904 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1905 	 MOPT_SET},
1906 #ifdef CONFIG_EXT4_DEBUG
1907 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1908 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1909 #endif
1910 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1911 	{Opt_err, 0, 0}
1912 };
1913 
1914 #if IS_ENABLED(CONFIG_UNICODE)
1915 static const struct ext4_sb_encodings {
1916 	__u16 magic;
1917 	char *name;
1918 	unsigned int version;
1919 } ext4_sb_encoding_map[] = {
1920 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1921 };
1922 
1923 static const struct ext4_sb_encodings *
1924 ext4_sb_read_encoding(const struct ext4_super_block *es)
1925 {
1926 	__u16 magic = le16_to_cpu(es->s_encoding);
1927 	int i;
1928 
1929 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1930 		if (magic == ext4_sb_encoding_map[i].magic)
1931 			return &ext4_sb_encoding_map[i];
1932 
1933 	return NULL;
1934 }
1935 #endif
1936 
1937 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1938 #define EXT4_SPEC_JQFMT				(1 <<  1)
1939 #define EXT4_SPEC_DATAJ				(1 <<  2)
1940 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1941 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1942 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1943 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1944 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1945 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1946 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1947 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1948 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1949 #define EXT4_SPEC_s_stripe			(1 << 13)
1950 #define EXT4_SPEC_s_resuid			(1 << 14)
1951 #define EXT4_SPEC_s_resgid			(1 << 15)
1952 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1953 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1954 #define EXT4_SPEC_s_sb_block			(1 << 18)
1955 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1956 
1957 struct ext4_fs_context {
1958 	char		*s_qf_names[EXT4_MAXQUOTAS];
1959 	struct fscrypt_dummy_policy dummy_enc_policy;
1960 	int		s_jquota_fmt;	/* Format of quota to use */
1961 #ifdef CONFIG_EXT4_DEBUG
1962 	int s_fc_debug_max_replay;
1963 #endif
1964 	unsigned short	qname_spec;
1965 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1966 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1967 	unsigned long	journal_devnum;
1968 	unsigned long	s_commit_interval;
1969 	unsigned long	s_stripe;
1970 	unsigned int	s_inode_readahead_blks;
1971 	unsigned int	s_want_extra_isize;
1972 	unsigned int	s_li_wait_mult;
1973 	unsigned int	s_max_dir_size_kb;
1974 	unsigned int	journal_ioprio;
1975 	unsigned int	vals_s_mount_opt;
1976 	unsigned int	mask_s_mount_opt;
1977 	unsigned int	vals_s_mount_opt2;
1978 	unsigned int	mask_s_mount_opt2;
1979 	unsigned int	opt_flags;	/* MOPT flags */
1980 	unsigned int	spec;
1981 	u32		s_max_batch_time;
1982 	u32		s_min_batch_time;
1983 	kuid_t		s_resuid;
1984 	kgid_t		s_resgid;
1985 	ext4_fsblk_t	s_sb_block;
1986 };
1987 
1988 static void ext4_fc_free(struct fs_context *fc)
1989 {
1990 	struct ext4_fs_context *ctx = fc->fs_private;
1991 	int i;
1992 
1993 	if (!ctx)
1994 		return;
1995 
1996 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1997 		kfree(ctx->s_qf_names[i]);
1998 
1999 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2000 	kfree(ctx);
2001 }
2002 
2003 int ext4_init_fs_context(struct fs_context *fc)
2004 {
2005 	struct ext4_fs_context *ctx;
2006 
2007 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2008 	if (!ctx)
2009 		return -ENOMEM;
2010 
2011 	fc->fs_private = ctx;
2012 	fc->ops = &ext4_context_ops;
2013 
2014 	return 0;
2015 }
2016 
2017 #ifdef CONFIG_QUOTA
2018 /*
2019  * Note the name of the specified quota file.
2020  */
2021 static int note_qf_name(struct fs_context *fc, int qtype,
2022 		       struct fs_parameter *param)
2023 {
2024 	struct ext4_fs_context *ctx = fc->fs_private;
2025 	char *qname;
2026 
2027 	if (param->size < 1) {
2028 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2029 		return -EINVAL;
2030 	}
2031 	if (strchr(param->string, '/')) {
2032 		ext4_msg(NULL, KERN_ERR,
2033 			 "quotafile must be on filesystem root");
2034 		return -EINVAL;
2035 	}
2036 	if (ctx->s_qf_names[qtype]) {
2037 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2038 			ext4_msg(NULL, KERN_ERR,
2039 				 "%s quota file already specified",
2040 				 QTYPE2NAME(qtype));
2041 			return -EINVAL;
2042 		}
2043 		return 0;
2044 	}
2045 
2046 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2047 	if (!qname) {
2048 		ext4_msg(NULL, KERN_ERR,
2049 			 "Not enough memory for storing quotafile name");
2050 		return -ENOMEM;
2051 	}
2052 	ctx->s_qf_names[qtype] = qname;
2053 	ctx->qname_spec |= 1 << qtype;
2054 	ctx->spec |= EXT4_SPEC_JQUOTA;
2055 	return 0;
2056 }
2057 
2058 /*
2059  * Clear the name of the specified quota file.
2060  */
2061 static int unnote_qf_name(struct fs_context *fc, int qtype)
2062 {
2063 	struct ext4_fs_context *ctx = fc->fs_private;
2064 
2065 	kfree(ctx->s_qf_names[qtype]);
2066 
2067 	ctx->s_qf_names[qtype] = NULL;
2068 	ctx->qname_spec |= 1 << qtype;
2069 	ctx->spec |= EXT4_SPEC_JQUOTA;
2070 	return 0;
2071 }
2072 #endif
2073 
2074 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2075 					    struct ext4_fs_context *ctx)
2076 {
2077 	int err;
2078 
2079 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2080 		ext4_msg(NULL, KERN_WARNING,
2081 			 "test_dummy_encryption option not supported");
2082 		return -EINVAL;
2083 	}
2084 	err = fscrypt_parse_test_dummy_encryption(param,
2085 						  &ctx->dummy_enc_policy);
2086 	if (err == -EINVAL) {
2087 		ext4_msg(NULL, KERN_WARNING,
2088 			 "Value of option \"%s\" is unrecognized", param->key);
2089 	} else if (err == -EEXIST) {
2090 		ext4_msg(NULL, KERN_WARNING,
2091 			 "Conflicting test_dummy_encryption options");
2092 		return -EINVAL;
2093 	}
2094 	return err;
2095 }
2096 
2097 #define EXT4_SET_CTX(name)						\
2098 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2099 				  unsigned long flag)			\
2100 {									\
2101 	ctx->mask_s_##name |= flag;					\
2102 	ctx->vals_s_##name |= flag;					\
2103 }
2104 
2105 #define EXT4_CLEAR_CTX(name)						\
2106 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2107 				    unsigned long flag)			\
2108 {									\
2109 	ctx->mask_s_##name |= flag;					\
2110 	ctx->vals_s_##name &= ~flag;					\
2111 }
2112 
2113 #define EXT4_TEST_CTX(name)						\
2114 static inline unsigned long						\
2115 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2116 {									\
2117 	return (ctx->vals_s_##name & flag);				\
2118 }
2119 
2120 EXT4_SET_CTX(flags); /* set only */
2121 EXT4_SET_CTX(mount_opt);
2122 EXT4_CLEAR_CTX(mount_opt);
2123 EXT4_TEST_CTX(mount_opt);
2124 EXT4_SET_CTX(mount_opt2);
2125 EXT4_CLEAR_CTX(mount_opt2);
2126 EXT4_TEST_CTX(mount_opt2);
2127 
2128 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2129 {
2130 	struct ext4_fs_context *ctx = fc->fs_private;
2131 	struct fs_parse_result result;
2132 	const struct mount_opts *m;
2133 	int is_remount;
2134 	int token;
2135 
2136 	token = fs_parse(fc, ext4_param_specs, param, &result);
2137 	if (token < 0)
2138 		return token;
2139 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2140 
2141 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2142 		if (token == m->token)
2143 			break;
2144 
2145 	ctx->opt_flags |= m->flags;
2146 
2147 	if (m->flags & MOPT_EXPLICIT) {
2148 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2149 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2150 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2151 			ctx_set_mount_opt2(ctx,
2152 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2153 		} else
2154 			return -EINVAL;
2155 	}
2156 
2157 	if (m->flags & MOPT_NOSUPPORT) {
2158 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2159 			 param->key);
2160 		return 0;
2161 	}
2162 
2163 	switch (token) {
2164 #ifdef CONFIG_QUOTA
2165 	case Opt_usrjquota:
2166 		if (!*param->string)
2167 			return unnote_qf_name(fc, USRQUOTA);
2168 		else
2169 			return note_qf_name(fc, USRQUOTA, param);
2170 	case Opt_grpjquota:
2171 		if (!*param->string)
2172 			return unnote_qf_name(fc, GRPQUOTA);
2173 		else
2174 			return note_qf_name(fc, GRPQUOTA, param);
2175 #endif
2176 	case Opt_sb:
2177 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2178 			ext4_msg(NULL, KERN_WARNING,
2179 				 "Ignoring %s option on remount", param->key);
2180 		} else {
2181 			ctx->s_sb_block = result.uint_32;
2182 			ctx->spec |= EXT4_SPEC_s_sb_block;
2183 		}
2184 		return 0;
2185 	case Opt_removed:
2186 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2187 			 param->key);
2188 		return 0;
2189 	case Opt_inlinecrypt:
2190 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2191 		ctx_set_flags(ctx, SB_INLINECRYPT);
2192 #else
2193 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2194 #endif
2195 		return 0;
2196 	case Opt_errors:
2197 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2198 		ctx_set_mount_opt(ctx, result.uint_32);
2199 		return 0;
2200 #ifdef CONFIG_QUOTA
2201 	case Opt_jqfmt:
2202 		ctx->s_jquota_fmt = result.uint_32;
2203 		ctx->spec |= EXT4_SPEC_JQFMT;
2204 		return 0;
2205 #endif
2206 	case Opt_data:
2207 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2208 		ctx_set_mount_opt(ctx, result.uint_32);
2209 		ctx->spec |= EXT4_SPEC_DATAJ;
2210 		return 0;
2211 	case Opt_commit:
2212 		if (result.uint_32 == 0)
2213 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2214 		else if (result.uint_32 > INT_MAX / HZ) {
2215 			ext4_msg(NULL, KERN_ERR,
2216 				 "Invalid commit interval %d, "
2217 				 "must be smaller than %d",
2218 				 result.uint_32, INT_MAX / HZ);
2219 			return -EINVAL;
2220 		}
2221 		ctx->s_commit_interval = HZ * result.uint_32;
2222 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2223 		return 0;
2224 	case Opt_debug_want_extra_isize:
2225 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2226 			ext4_msg(NULL, KERN_ERR,
2227 				 "Invalid want_extra_isize %d", result.uint_32);
2228 			return -EINVAL;
2229 		}
2230 		ctx->s_want_extra_isize = result.uint_32;
2231 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2232 		return 0;
2233 	case Opt_max_batch_time:
2234 		ctx->s_max_batch_time = result.uint_32;
2235 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2236 		return 0;
2237 	case Opt_min_batch_time:
2238 		ctx->s_min_batch_time = result.uint_32;
2239 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2240 		return 0;
2241 	case Opt_inode_readahead_blks:
2242 		if (result.uint_32 &&
2243 		    (result.uint_32 > (1 << 30) ||
2244 		     !is_power_of_2(result.uint_32))) {
2245 			ext4_msg(NULL, KERN_ERR,
2246 				 "EXT4-fs: inode_readahead_blks must be "
2247 				 "0 or a power of 2 smaller than 2^31");
2248 			return -EINVAL;
2249 		}
2250 		ctx->s_inode_readahead_blks = result.uint_32;
2251 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2252 		return 0;
2253 	case Opt_init_itable:
2254 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2255 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2256 		if (param->type == fs_value_is_string)
2257 			ctx->s_li_wait_mult = result.uint_32;
2258 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2259 		return 0;
2260 	case Opt_max_dir_size_kb:
2261 		ctx->s_max_dir_size_kb = result.uint_32;
2262 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2263 		return 0;
2264 #ifdef CONFIG_EXT4_DEBUG
2265 	case Opt_fc_debug_max_replay:
2266 		ctx->s_fc_debug_max_replay = result.uint_32;
2267 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2268 		return 0;
2269 #endif
2270 	case Opt_stripe:
2271 		ctx->s_stripe = result.uint_32;
2272 		ctx->spec |= EXT4_SPEC_s_stripe;
2273 		return 0;
2274 	case Opt_resuid:
2275 		ctx->s_resuid = result.uid;
2276 		ctx->spec |= EXT4_SPEC_s_resuid;
2277 		return 0;
2278 	case Opt_resgid:
2279 		ctx->s_resgid = result.gid;
2280 		ctx->spec |= EXT4_SPEC_s_resgid;
2281 		return 0;
2282 	case Opt_journal_dev:
2283 		if (is_remount) {
2284 			ext4_msg(NULL, KERN_ERR,
2285 				 "Cannot specify journal on remount");
2286 			return -EINVAL;
2287 		}
2288 		ctx->journal_devnum = result.uint_32;
2289 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2290 		return 0;
2291 	case Opt_journal_path:
2292 	{
2293 		struct inode *journal_inode;
2294 		struct path path;
2295 		int error;
2296 
2297 		if (is_remount) {
2298 			ext4_msg(NULL, KERN_ERR,
2299 				 "Cannot specify journal on remount");
2300 			return -EINVAL;
2301 		}
2302 
2303 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2304 		if (error) {
2305 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2306 				 "journal device path");
2307 			return -EINVAL;
2308 		}
2309 
2310 		journal_inode = d_inode(path.dentry);
2311 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2312 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2313 		path_put(&path);
2314 		return 0;
2315 	}
2316 	case Opt_journal_ioprio:
2317 		if (result.uint_32 > 7) {
2318 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2319 				 " (must be 0-7)");
2320 			return -EINVAL;
2321 		}
2322 		ctx->journal_ioprio =
2323 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2324 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2325 		return 0;
2326 	case Opt_test_dummy_encryption:
2327 		return ext4_parse_test_dummy_encryption(param, ctx);
2328 	case Opt_dax:
2329 	case Opt_dax_type:
2330 #ifdef CONFIG_FS_DAX
2331 	{
2332 		int type = (token == Opt_dax) ?
2333 			   Opt_dax : result.uint_32;
2334 
2335 		switch (type) {
2336 		case Opt_dax:
2337 		case Opt_dax_always:
2338 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2339 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2340 			break;
2341 		case Opt_dax_never:
2342 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2343 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2344 			break;
2345 		case Opt_dax_inode:
2346 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2347 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2348 			/* Strictly for printing options */
2349 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2350 			break;
2351 		}
2352 		return 0;
2353 	}
2354 #else
2355 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2356 		return -EINVAL;
2357 #endif
2358 	case Opt_data_err:
2359 		if (result.uint_32 == Opt_data_err_abort)
2360 			ctx_set_mount_opt(ctx, m->mount_opt);
2361 		else if (result.uint_32 == Opt_data_err_ignore)
2362 			ctx_clear_mount_opt(ctx, m->mount_opt);
2363 		return 0;
2364 	case Opt_mb_optimize_scan:
2365 		if (result.int_32 == 1) {
2366 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2367 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2368 		} else if (result.int_32 == 0) {
2369 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2370 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2371 		} else {
2372 			ext4_msg(NULL, KERN_WARNING,
2373 				 "mb_optimize_scan should be set to 0 or 1.");
2374 			return -EINVAL;
2375 		}
2376 		return 0;
2377 	}
2378 
2379 	/*
2380 	 * At this point we should only be getting options requiring MOPT_SET,
2381 	 * or MOPT_CLEAR. Anything else is a bug
2382 	 */
2383 	if (m->token == Opt_err) {
2384 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2385 			 param->key);
2386 		WARN_ON(1);
2387 		return -EINVAL;
2388 	}
2389 
2390 	else {
2391 		unsigned int set = 0;
2392 
2393 		if ((param->type == fs_value_is_flag) ||
2394 		    result.uint_32 > 0)
2395 			set = 1;
2396 
2397 		if (m->flags & MOPT_CLEAR)
2398 			set = !set;
2399 		else if (unlikely(!(m->flags & MOPT_SET))) {
2400 			ext4_msg(NULL, KERN_WARNING,
2401 				 "buggy handling of option %s",
2402 				 param->key);
2403 			WARN_ON(1);
2404 			return -EINVAL;
2405 		}
2406 		if (m->flags & MOPT_2) {
2407 			if (set != 0)
2408 				ctx_set_mount_opt2(ctx, m->mount_opt);
2409 			else
2410 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2411 		} else {
2412 			if (set != 0)
2413 				ctx_set_mount_opt(ctx, m->mount_opt);
2414 			else
2415 				ctx_clear_mount_opt(ctx, m->mount_opt);
2416 		}
2417 	}
2418 
2419 	return 0;
2420 }
2421 
2422 static int parse_options(struct fs_context *fc, char *options)
2423 {
2424 	struct fs_parameter param;
2425 	int ret;
2426 	char *key;
2427 
2428 	if (!options)
2429 		return 0;
2430 
2431 	while ((key = strsep(&options, ",")) != NULL) {
2432 		if (*key) {
2433 			size_t v_len = 0;
2434 			char *value = strchr(key, '=');
2435 
2436 			param.type = fs_value_is_flag;
2437 			param.string = NULL;
2438 
2439 			if (value) {
2440 				if (value == key)
2441 					continue;
2442 
2443 				*value++ = 0;
2444 				v_len = strlen(value);
2445 				param.string = kmemdup_nul(value, v_len,
2446 							   GFP_KERNEL);
2447 				if (!param.string)
2448 					return -ENOMEM;
2449 				param.type = fs_value_is_string;
2450 			}
2451 
2452 			param.key = key;
2453 			param.size = v_len;
2454 
2455 			ret = ext4_parse_param(fc, &param);
2456 			kfree(param.string);
2457 			if (ret < 0)
2458 				return ret;
2459 		}
2460 	}
2461 
2462 	ret = ext4_validate_options(fc);
2463 	if (ret < 0)
2464 		return ret;
2465 
2466 	return 0;
2467 }
2468 
2469 static int parse_apply_sb_mount_options(struct super_block *sb,
2470 					struct ext4_fs_context *m_ctx)
2471 {
2472 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2473 	char *s_mount_opts = NULL;
2474 	struct ext4_fs_context *s_ctx = NULL;
2475 	struct fs_context *fc = NULL;
2476 	int ret = -ENOMEM;
2477 
2478 	if (!sbi->s_es->s_mount_opts[0])
2479 		return 0;
2480 
2481 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2482 				sizeof(sbi->s_es->s_mount_opts),
2483 				GFP_KERNEL);
2484 	if (!s_mount_opts)
2485 		return ret;
2486 
2487 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2488 	if (!fc)
2489 		goto out_free;
2490 
2491 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2492 	if (!s_ctx)
2493 		goto out_free;
2494 
2495 	fc->fs_private = s_ctx;
2496 	fc->s_fs_info = sbi;
2497 
2498 	ret = parse_options(fc, s_mount_opts);
2499 	if (ret < 0)
2500 		goto parse_failed;
2501 
2502 	ret = ext4_check_opt_consistency(fc, sb);
2503 	if (ret < 0) {
2504 parse_failed:
2505 		ext4_msg(sb, KERN_WARNING,
2506 			 "failed to parse options in superblock: %s",
2507 			 s_mount_opts);
2508 		ret = 0;
2509 		goto out_free;
2510 	}
2511 
2512 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2513 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2514 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2515 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2516 
2517 	ext4_apply_options(fc, sb);
2518 	ret = 0;
2519 
2520 out_free:
2521 	if (fc) {
2522 		ext4_fc_free(fc);
2523 		kfree(fc);
2524 	}
2525 	kfree(s_mount_opts);
2526 	return ret;
2527 }
2528 
2529 static void ext4_apply_quota_options(struct fs_context *fc,
2530 				     struct super_block *sb)
2531 {
2532 #ifdef CONFIG_QUOTA
2533 	bool quota_feature = ext4_has_feature_quota(sb);
2534 	struct ext4_fs_context *ctx = fc->fs_private;
2535 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2536 	char *qname;
2537 	int i;
2538 
2539 	if (quota_feature)
2540 		return;
2541 
2542 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2543 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2544 			if (!(ctx->qname_spec & (1 << i)))
2545 				continue;
2546 
2547 			qname = ctx->s_qf_names[i]; /* May be NULL */
2548 			if (qname)
2549 				set_opt(sb, QUOTA);
2550 			ctx->s_qf_names[i] = NULL;
2551 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2552 						lockdep_is_held(&sb->s_umount));
2553 			if (qname)
2554 				kfree_rcu_mightsleep(qname);
2555 		}
2556 	}
2557 
2558 	if (ctx->spec & EXT4_SPEC_JQFMT)
2559 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2560 #endif
2561 }
2562 
2563 /*
2564  * Check quota settings consistency.
2565  */
2566 static int ext4_check_quota_consistency(struct fs_context *fc,
2567 					struct super_block *sb)
2568 {
2569 #ifdef CONFIG_QUOTA
2570 	struct ext4_fs_context *ctx = fc->fs_private;
2571 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2572 	bool quota_feature = ext4_has_feature_quota(sb);
2573 	bool quota_loaded = sb_any_quota_loaded(sb);
2574 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2575 	int quota_flags, i;
2576 
2577 	/*
2578 	 * We do the test below only for project quotas. 'usrquota' and
2579 	 * 'grpquota' mount options are allowed even without quota feature
2580 	 * to support legacy quotas in quota files.
2581 	 */
2582 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2583 	    !ext4_has_feature_project(sb)) {
2584 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2585 			 "Cannot enable project quota enforcement.");
2586 		return -EINVAL;
2587 	}
2588 
2589 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2590 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2591 	if (quota_loaded &&
2592 	    ctx->mask_s_mount_opt & quota_flags &&
2593 	    !ctx_test_mount_opt(ctx, quota_flags))
2594 		goto err_quota_change;
2595 
2596 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2597 
2598 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2599 			if (!(ctx->qname_spec & (1 << i)))
2600 				continue;
2601 
2602 			if (quota_loaded &&
2603 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2604 				goto err_jquota_change;
2605 
2606 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2607 			    strcmp(get_qf_name(sb, sbi, i),
2608 				   ctx->s_qf_names[i]) != 0)
2609 				goto err_jquota_specified;
2610 		}
2611 
2612 		if (quota_feature) {
2613 			ext4_msg(NULL, KERN_INFO,
2614 				 "Journaled quota options ignored when "
2615 				 "QUOTA feature is enabled");
2616 			return 0;
2617 		}
2618 	}
2619 
2620 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2621 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2622 			goto err_jquota_change;
2623 		if (quota_feature) {
2624 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2625 				 "ignored when QUOTA feature is enabled");
2626 			return 0;
2627 		}
2628 	}
2629 
2630 	/* Make sure we don't mix old and new quota format */
2631 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2632 		       ctx->s_qf_names[USRQUOTA]);
2633 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2634 		       ctx->s_qf_names[GRPQUOTA]);
2635 
2636 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2637 		    test_opt(sb, USRQUOTA));
2638 
2639 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2640 		    test_opt(sb, GRPQUOTA));
2641 
2642 	if (usr_qf_name) {
2643 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2644 		usrquota = false;
2645 	}
2646 	if (grp_qf_name) {
2647 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2648 		grpquota = false;
2649 	}
2650 
2651 	if (usr_qf_name || grp_qf_name) {
2652 		if (usrquota || grpquota) {
2653 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2654 				 "format mixing");
2655 			return -EINVAL;
2656 		}
2657 
2658 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2659 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2660 				 "not specified");
2661 			return -EINVAL;
2662 		}
2663 	}
2664 
2665 	return 0;
2666 
2667 err_quota_change:
2668 	ext4_msg(NULL, KERN_ERR,
2669 		 "Cannot change quota options when quota turned on");
2670 	return -EINVAL;
2671 err_jquota_change:
2672 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2673 		 "options when quota turned on");
2674 	return -EINVAL;
2675 err_jquota_specified:
2676 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2677 		 QTYPE2NAME(i));
2678 	return -EINVAL;
2679 #else
2680 	return 0;
2681 #endif
2682 }
2683 
2684 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2685 					    struct super_block *sb)
2686 {
2687 	const struct ext4_fs_context *ctx = fc->fs_private;
2688 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2689 
2690 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2691 		return 0;
2692 
2693 	if (!ext4_has_feature_encrypt(sb)) {
2694 		ext4_msg(NULL, KERN_WARNING,
2695 			 "test_dummy_encryption requires encrypt feature");
2696 		return -EINVAL;
2697 	}
2698 	/*
2699 	 * This mount option is just for testing, and it's not worthwhile to
2700 	 * implement the extra complexity (e.g. RCU protection) that would be
2701 	 * needed to allow it to be set or changed during remount.  We do allow
2702 	 * it to be specified during remount, but only if there is no change.
2703 	 */
2704 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2705 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2706 						 &ctx->dummy_enc_policy))
2707 			return 0;
2708 		ext4_msg(NULL, KERN_WARNING,
2709 			 "Can't set or change test_dummy_encryption on remount");
2710 		return -EINVAL;
2711 	}
2712 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2713 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2714 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2715 						 &ctx->dummy_enc_policy))
2716 			return 0;
2717 		ext4_msg(NULL, KERN_WARNING,
2718 			 "Conflicting test_dummy_encryption options");
2719 		return -EINVAL;
2720 	}
2721 	return 0;
2722 }
2723 
2724 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2725 					     struct super_block *sb)
2726 {
2727 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2728 	    /* if already set, it was already verified to be the same */
2729 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2730 		return;
2731 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2732 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2733 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2734 }
2735 
2736 static int ext4_check_opt_consistency(struct fs_context *fc,
2737 				      struct super_block *sb)
2738 {
2739 	struct ext4_fs_context *ctx = fc->fs_private;
2740 	struct ext4_sb_info *sbi = fc->s_fs_info;
2741 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2742 	int err;
2743 
2744 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2745 		ext4_msg(NULL, KERN_ERR,
2746 			 "Mount option(s) incompatible with ext2");
2747 		return -EINVAL;
2748 	}
2749 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2750 		ext4_msg(NULL, KERN_ERR,
2751 			 "Mount option(s) incompatible with ext3");
2752 		return -EINVAL;
2753 	}
2754 
2755 	if (ctx->s_want_extra_isize >
2756 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2757 		ext4_msg(NULL, KERN_ERR,
2758 			 "Invalid want_extra_isize %d",
2759 			 ctx->s_want_extra_isize);
2760 		return -EINVAL;
2761 	}
2762 
2763 	err = ext4_check_test_dummy_encryption(fc, sb);
2764 	if (err)
2765 		return err;
2766 
2767 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2768 		if (!sbi->s_journal) {
2769 			ext4_msg(NULL, KERN_WARNING,
2770 				 "Remounting file system with no journal "
2771 				 "so ignoring journalled data option");
2772 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2773 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2774 			   test_opt(sb, DATA_FLAGS)) {
2775 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2776 				 "on remount");
2777 			return -EINVAL;
2778 		}
2779 	}
2780 
2781 	if (is_remount) {
2782 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2783 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2784 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2785 				 "both data=journal and dax");
2786 			return -EINVAL;
2787 		}
2788 
2789 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2790 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2791 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2792 fail_dax_change_remount:
2793 			ext4_msg(NULL, KERN_ERR, "can't change "
2794 				 "dax mount option while remounting");
2795 			return -EINVAL;
2796 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2797 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2798 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2799 			goto fail_dax_change_remount;
2800 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2801 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2802 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2803 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2804 			goto fail_dax_change_remount;
2805 		}
2806 	}
2807 
2808 	return ext4_check_quota_consistency(fc, sb);
2809 }
2810 
2811 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2812 {
2813 	struct ext4_fs_context *ctx = fc->fs_private;
2814 	struct ext4_sb_info *sbi = fc->s_fs_info;
2815 
2816 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2817 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2818 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2819 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2820 	sb->s_flags &= ~ctx->mask_s_flags;
2821 	sb->s_flags |= ctx->vals_s_flags;
2822 
2823 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2824 	APPLY(s_commit_interval);
2825 	APPLY(s_stripe);
2826 	APPLY(s_max_batch_time);
2827 	APPLY(s_min_batch_time);
2828 	APPLY(s_want_extra_isize);
2829 	APPLY(s_inode_readahead_blks);
2830 	APPLY(s_max_dir_size_kb);
2831 	APPLY(s_li_wait_mult);
2832 	APPLY(s_resgid);
2833 	APPLY(s_resuid);
2834 
2835 #ifdef CONFIG_EXT4_DEBUG
2836 	APPLY(s_fc_debug_max_replay);
2837 #endif
2838 
2839 	ext4_apply_quota_options(fc, sb);
2840 	ext4_apply_test_dummy_encryption(ctx, sb);
2841 }
2842 
2843 
2844 static int ext4_validate_options(struct fs_context *fc)
2845 {
2846 #ifdef CONFIG_QUOTA
2847 	struct ext4_fs_context *ctx = fc->fs_private;
2848 	char *usr_qf_name, *grp_qf_name;
2849 
2850 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2851 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2852 
2853 	if (usr_qf_name || grp_qf_name) {
2854 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2855 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2856 
2857 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2858 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2859 
2860 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2861 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2862 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2863 				 "format mixing");
2864 			return -EINVAL;
2865 		}
2866 	}
2867 #endif
2868 	return 1;
2869 }
2870 
2871 static inline void ext4_show_quota_options(struct seq_file *seq,
2872 					   struct super_block *sb)
2873 {
2874 #if defined(CONFIG_QUOTA)
2875 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2876 	char *usr_qf_name, *grp_qf_name;
2877 
2878 	if (sbi->s_jquota_fmt) {
2879 		char *fmtname = "";
2880 
2881 		switch (sbi->s_jquota_fmt) {
2882 		case QFMT_VFS_OLD:
2883 			fmtname = "vfsold";
2884 			break;
2885 		case QFMT_VFS_V0:
2886 			fmtname = "vfsv0";
2887 			break;
2888 		case QFMT_VFS_V1:
2889 			fmtname = "vfsv1";
2890 			break;
2891 		}
2892 		seq_printf(seq, ",jqfmt=%s", fmtname);
2893 	}
2894 
2895 	rcu_read_lock();
2896 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2897 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2898 	if (usr_qf_name)
2899 		seq_show_option(seq, "usrjquota", usr_qf_name);
2900 	if (grp_qf_name)
2901 		seq_show_option(seq, "grpjquota", grp_qf_name);
2902 	rcu_read_unlock();
2903 #endif
2904 }
2905 
2906 static const char *token2str(int token)
2907 {
2908 	const struct fs_parameter_spec *spec;
2909 
2910 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2911 		if (spec->opt == token && !spec->type)
2912 			break;
2913 	return spec->name;
2914 }
2915 
2916 /*
2917  * Show an option if
2918  *  - it's set to a non-default value OR
2919  *  - if the per-sb default is different from the global default
2920  */
2921 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2922 			      int nodefs)
2923 {
2924 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2925 	struct ext4_super_block *es = sbi->s_es;
2926 	int def_errors;
2927 	const struct mount_opts *m;
2928 	char sep = nodefs ? '\n' : ',';
2929 
2930 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2931 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2932 
2933 	if (sbi->s_sb_block != 1)
2934 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2935 
2936 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2937 		int want_set = m->flags & MOPT_SET;
2938 		int opt_2 = m->flags & MOPT_2;
2939 		unsigned int mount_opt, def_mount_opt;
2940 
2941 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2942 		    m->flags & MOPT_SKIP)
2943 			continue;
2944 
2945 		if (opt_2) {
2946 			mount_opt = sbi->s_mount_opt2;
2947 			def_mount_opt = sbi->s_def_mount_opt2;
2948 		} else {
2949 			mount_opt = sbi->s_mount_opt;
2950 			def_mount_opt = sbi->s_def_mount_opt;
2951 		}
2952 		/* skip if same as the default */
2953 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2954 			continue;
2955 		/* select Opt_noFoo vs Opt_Foo */
2956 		if ((want_set &&
2957 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2958 		    (!want_set && (mount_opt & m->mount_opt)))
2959 			continue;
2960 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2961 	}
2962 
2963 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2964 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2965 		SEQ_OPTS_PRINT("resuid=%u",
2966 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2967 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2968 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2969 		SEQ_OPTS_PRINT("resgid=%u",
2970 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2971 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2972 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2973 		SEQ_OPTS_PUTS("errors=remount-ro");
2974 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2975 		SEQ_OPTS_PUTS("errors=continue");
2976 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2977 		SEQ_OPTS_PUTS("errors=panic");
2978 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2979 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2980 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2981 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2982 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2983 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2984 	if (nodefs || sbi->s_stripe)
2985 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2986 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2987 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
2988 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2989 			SEQ_OPTS_PUTS("data=journal");
2990 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2991 			SEQ_OPTS_PUTS("data=ordered");
2992 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2993 			SEQ_OPTS_PUTS("data=writeback");
2994 	}
2995 	if (nodefs ||
2996 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2997 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2998 			       sbi->s_inode_readahead_blks);
2999 
3000 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3001 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3002 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3003 	if (nodefs || sbi->s_max_dir_size_kb)
3004 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3005 	if (test_opt(sb, DATA_ERR_ABORT))
3006 		SEQ_OPTS_PUTS("data_err=abort");
3007 
3008 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3009 
3010 	if (sb->s_flags & SB_INLINECRYPT)
3011 		SEQ_OPTS_PUTS("inlinecrypt");
3012 
3013 	if (test_opt(sb, DAX_ALWAYS)) {
3014 		if (IS_EXT2_SB(sb))
3015 			SEQ_OPTS_PUTS("dax");
3016 		else
3017 			SEQ_OPTS_PUTS("dax=always");
3018 	} else if (test_opt2(sb, DAX_NEVER)) {
3019 		SEQ_OPTS_PUTS("dax=never");
3020 	} else if (test_opt2(sb, DAX_INODE)) {
3021 		SEQ_OPTS_PUTS("dax=inode");
3022 	}
3023 
3024 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3025 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3026 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3027 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3028 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3029 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3030 	}
3031 
3032 	ext4_show_quota_options(seq, sb);
3033 	return 0;
3034 }
3035 
3036 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3037 {
3038 	return _ext4_show_options(seq, root->d_sb, 0);
3039 }
3040 
3041 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3042 {
3043 	struct super_block *sb = seq->private;
3044 	int rc;
3045 
3046 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3047 	rc = _ext4_show_options(seq, sb, 1);
3048 	seq_puts(seq, "\n");
3049 	return rc;
3050 }
3051 
3052 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3053 			    int read_only)
3054 {
3055 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3056 	int err = 0;
3057 
3058 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3059 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3060 			 "forcing read-only mode");
3061 		err = -EROFS;
3062 		goto done;
3063 	}
3064 	if (read_only)
3065 		goto done;
3066 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3067 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3068 			 "running e2fsck is recommended");
3069 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3070 		ext4_msg(sb, KERN_WARNING,
3071 			 "warning: mounting fs with errors, "
3072 			 "running e2fsck is recommended");
3073 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3074 		 le16_to_cpu(es->s_mnt_count) >=
3075 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3076 		ext4_msg(sb, KERN_WARNING,
3077 			 "warning: maximal mount count reached, "
3078 			 "running e2fsck is recommended");
3079 	else if (le32_to_cpu(es->s_checkinterval) &&
3080 		 (ext4_get_tstamp(es, s_lastcheck) +
3081 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3082 		ext4_msg(sb, KERN_WARNING,
3083 			 "warning: checktime reached, "
3084 			 "running e2fsck is recommended");
3085 	if (!sbi->s_journal)
3086 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3087 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3088 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3089 	le16_add_cpu(&es->s_mnt_count, 1);
3090 	ext4_update_tstamp(es, s_mtime);
3091 	if (sbi->s_journal) {
3092 		ext4_set_feature_journal_needs_recovery(sb);
3093 		if (ext4_has_feature_orphan_file(sb))
3094 			ext4_set_feature_orphan_present(sb);
3095 	}
3096 
3097 	err = ext4_commit_super(sb);
3098 done:
3099 	if (test_opt(sb, DEBUG))
3100 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3101 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3102 			sb->s_blocksize,
3103 			sbi->s_groups_count,
3104 			EXT4_BLOCKS_PER_GROUP(sb),
3105 			EXT4_INODES_PER_GROUP(sb),
3106 			sbi->s_mount_opt, sbi->s_mount_opt2);
3107 	return err;
3108 }
3109 
3110 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3111 {
3112 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3113 	struct flex_groups **old_groups, **new_groups;
3114 	int size, i, j;
3115 
3116 	if (!sbi->s_log_groups_per_flex)
3117 		return 0;
3118 
3119 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3120 	if (size <= sbi->s_flex_groups_allocated)
3121 		return 0;
3122 
3123 	new_groups = kvzalloc(roundup_pow_of_two(size *
3124 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3125 	if (!new_groups) {
3126 		ext4_msg(sb, KERN_ERR,
3127 			 "not enough memory for %d flex group pointers", size);
3128 		return -ENOMEM;
3129 	}
3130 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3131 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3132 					 sizeof(struct flex_groups)),
3133 					 GFP_KERNEL);
3134 		if (!new_groups[i]) {
3135 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3136 				kvfree(new_groups[j]);
3137 			kvfree(new_groups);
3138 			ext4_msg(sb, KERN_ERR,
3139 				 "not enough memory for %d flex groups", size);
3140 			return -ENOMEM;
3141 		}
3142 	}
3143 	rcu_read_lock();
3144 	old_groups = rcu_dereference(sbi->s_flex_groups);
3145 	if (old_groups)
3146 		memcpy(new_groups, old_groups,
3147 		       (sbi->s_flex_groups_allocated *
3148 			sizeof(struct flex_groups *)));
3149 	rcu_read_unlock();
3150 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3151 	sbi->s_flex_groups_allocated = size;
3152 	if (old_groups)
3153 		ext4_kvfree_array_rcu(old_groups);
3154 	return 0;
3155 }
3156 
3157 static int ext4_fill_flex_info(struct super_block *sb)
3158 {
3159 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3160 	struct ext4_group_desc *gdp = NULL;
3161 	struct flex_groups *fg;
3162 	ext4_group_t flex_group;
3163 	int i, err;
3164 
3165 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3166 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3167 		sbi->s_log_groups_per_flex = 0;
3168 		return 1;
3169 	}
3170 
3171 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3172 	if (err)
3173 		goto failed;
3174 
3175 	for (i = 0; i < sbi->s_groups_count; i++) {
3176 		gdp = ext4_get_group_desc(sb, i, NULL);
3177 
3178 		flex_group = ext4_flex_group(sbi, i);
3179 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3180 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3181 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3182 			     &fg->free_clusters);
3183 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3184 	}
3185 
3186 	return 1;
3187 failed:
3188 	return 0;
3189 }
3190 
3191 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3192 				   struct ext4_group_desc *gdp)
3193 {
3194 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3195 	__u16 crc = 0;
3196 	__le32 le_group = cpu_to_le32(block_group);
3197 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3198 
3199 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3200 		/* Use new metadata_csum algorithm */
3201 		__u32 csum32;
3202 		__u16 dummy_csum = 0;
3203 
3204 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3205 				     sizeof(le_group));
3206 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3207 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3208 				     sizeof(dummy_csum));
3209 		offset += sizeof(dummy_csum);
3210 		if (offset < sbi->s_desc_size)
3211 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3212 					     sbi->s_desc_size - offset);
3213 
3214 		crc = csum32 & 0xFFFF;
3215 		goto out;
3216 	}
3217 
3218 	/* old crc16 code */
3219 	if (!ext4_has_feature_gdt_csum(sb))
3220 		return 0;
3221 
3222 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3223 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3224 	crc = crc16(crc, (__u8 *)gdp, offset);
3225 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3226 	/* for checksum of struct ext4_group_desc do the rest...*/
3227 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3228 		crc = crc16(crc, (__u8 *)gdp + offset,
3229 			    sbi->s_desc_size - offset);
3230 
3231 out:
3232 	return cpu_to_le16(crc);
3233 }
3234 
3235 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3236 				struct ext4_group_desc *gdp)
3237 {
3238 	if (ext4_has_group_desc_csum(sb) &&
3239 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3240 		return 0;
3241 
3242 	return 1;
3243 }
3244 
3245 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3246 			      struct ext4_group_desc *gdp)
3247 {
3248 	if (!ext4_has_group_desc_csum(sb))
3249 		return;
3250 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3251 }
3252 
3253 /* Called at mount-time, super-block is locked */
3254 static int ext4_check_descriptors(struct super_block *sb,
3255 				  ext4_fsblk_t sb_block,
3256 				  ext4_group_t *first_not_zeroed)
3257 {
3258 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3259 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3260 	ext4_fsblk_t last_block;
3261 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3262 	ext4_fsblk_t block_bitmap;
3263 	ext4_fsblk_t inode_bitmap;
3264 	ext4_fsblk_t inode_table;
3265 	int flexbg_flag = 0;
3266 	ext4_group_t i, grp = sbi->s_groups_count;
3267 
3268 	if (ext4_has_feature_flex_bg(sb))
3269 		flexbg_flag = 1;
3270 
3271 	ext4_debug("Checking group descriptors");
3272 
3273 	for (i = 0; i < sbi->s_groups_count; i++) {
3274 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3275 
3276 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3277 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3278 		else
3279 			last_block = first_block +
3280 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3281 
3282 		if ((grp == sbi->s_groups_count) &&
3283 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3284 			grp = i;
3285 
3286 		block_bitmap = ext4_block_bitmap(sb, gdp);
3287 		if (block_bitmap == sb_block) {
3288 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3289 				 "Block bitmap for group %u overlaps "
3290 				 "superblock", i);
3291 			if (!sb_rdonly(sb))
3292 				return 0;
3293 		}
3294 		if (block_bitmap >= sb_block + 1 &&
3295 		    block_bitmap <= last_bg_block) {
3296 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3297 				 "Block bitmap for group %u overlaps "
3298 				 "block group descriptors", i);
3299 			if (!sb_rdonly(sb))
3300 				return 0;
3301 		}
3302 		if (block_bitmap < first_block || block_bitmap > last_block) {
3303 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3304 			       "Block bitmap for group %u not in group "
3305 			       "(block %llu)!", i, block_bitmap);
3306 			return 0;
3307 		}
3308 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3309 		if (inode_bitmap == sb_block) {
3310 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3311 				 "Inode bitmap for group %u overlaps "
3312 				 "superblock", i);
3313 			if (!sb_rdonly(sb))
3314 				return 0;
3315 		}
3316 		if (inode_bitmap >= sb_block + 1 &&
3317 		    inode_bitmap <= last_bg_block) {
3318 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3319 				 "Inode bitmap for group %u overlaps "
3320 				 "block group descriptors", i);
3321 			if (!sb_rdonly(sb))
3322 				return 0;
3323 		}
3324 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3325 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3326 			       "Inode bitmap for group %u not in group "
3327 			       "(block %llu)!", i, inode_bitmap);
3328 			return 0;
3329 		}
3330 		inode_table = ext4_inode_table(sb, gdp);
3331 		if (inode_table == sb_block) {
3332 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3333 				 "Inode table for group %u overlaps "
3334 				 "superblock", i);
3335 			if (!sb_rdonly(sb))
3336 				return 0;
3337 		}
3338 		if (inode_table >= sb_block + 1 &&
3339 		    inode_table <= last_bg_block) {
3340 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3341 				 "Inode table for group %u overlaps "
3342 				 "block group descriptors", i);
3343 			if (!sb_rdonly(sb))
3344 				return 0;
3345 		}
3346 		if (inode_table < first_block ||
3347 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3348 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3349 			       "Inode table for group %u not in group "
3350 			       "(block %llu)!", i, inode_table);
3351 			return 0;
3352 		}
3353 		ext4_lock_group(sb, i);
3354 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3355 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3356 				 "Checksum for group %u failed (%u!=%u)",
3357 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3358 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3359 			if (!sb_rdonly(sb)) {
3360 				ext4_unlock_group(sb, i);
3361 				return 0;
3362 			}
3363 		}
3364 		ext4_unlock_group(sb, i);
3365 		if (!flexbg_flag)
3366 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3367 	}
3368 	if (NULL != first_not_zeroed)
3369 		*first_not_zeroed = grp;
3370 	return 1;
3371 }
3372 
3373 /*
3374  * Maximal extent format file size.
3375  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3376  * extent format containers, within a sector_t, and within i_blocks
3377  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3378  * so that won't be a limiting factor.
3379  *
3380  * However there is other limiting factor. We do store extents in the form
3381  * of starting block and length, hence the resulting length of the extent
3382  * covering maximum file size must fit into on-disk format containers as
3383  * well. Given that length is always by 1 unit bigger than max unit (because
3384  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3385  *
3386  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3387  */
3388 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3389 {
3390 	loff_t res;
3391 	loff_t upper_limit = MAX_LFS_FILESIZE;
3392 
3393 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3394 
3395 	if (!has_huge_files) {
3396 		upper_limit = (1LL << 32) - 1;
3397 
3398 		/* total blocks in file system block size */
3399 		upper_limit >>= (blkbits - 9);
3400 		upper_limit <<= blkbits;
3401 	}
3402 
3403 	/*
3404 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3405 	 * by one fs block, so ee_len can cover the extent of maximum file
3406 	 * size
3407 	 */
3408 	res = (1LL << 32) - 1;
3409 	res <<= blkbits;
3410 
3411 	/* Sanity check against vm- & vfs- imposed limits */
3412 	if (res > upper_limit)
3413 		res = upper_limit;
3414 
3415 	return res;
3416 }
3417 
3418 /*
3419  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3420  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3421  * We need to be 1 filesystem block less than the 2^48 sector limit.
3422  */
3423 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3424 {
3425 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3426 	int meta_blocks;
3427 	unsigned int ppb = 1 << (bits - 2);
3428 
3429 	/*
3430 	 * This is calculated to be the largest file size for a dense, block
3431 	 * mapped file such that the file's total number of 512-byte sectors,
3432 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3433 	 *
3434 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3435 	 * number of 512-byte sectors of the file.
3436 	 */
3437 	if (!has_huge_files) {
3438 		/*
3439 		 * !has_huge_files or implies that the inode i_block field
3440 		 * represents total file blocks in 2^32 512-byte sectors ==
3441 		 * size of vfs inode i_blocks * 8
3442 		 */
3443 		upper_limit = (1LL << 32) - 1;
3444 
3445 		/* total blocks in file system block size */
3446 		upper_limit >>= (bits - 9);
3447 
3448 	} else {
3449 		/*
3450 		 * We use 48 bit ext4_inode i_blocks
3451 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3452 		 * represent total number of blocks in
3453 		 * file system block size
3454 		 */
3455 		upper_limit = (1LL << 48) - 1;
3456 
3457 	}
3458 
3459 	/* Compute how many blocks we can address by block tree */
3460 	res += ppb;
3461 	res += ppb * ppb;
3462 	res += ((loff_t)ppb) * ppb * ppb;
3463 	/* Compute how many metadata blocks are needed */
3464 	meta_blocks = 1;
3465 	meta_blocks += 1 + ppb;
3466 	meta_blocks += 1 + ppb + ppb * ppb;
3467 	/* Does block tree limit file size? */
3468 	if (res + meta_blocks <= upper_limit)
3469 		goto check_lfs;
3470 
3471 	res = upper_limit;
3472 	/* How many metadata blocks are needed for addressing upper_limit? */
3473 	upper_limit -= EXT4_NDIR_BLOCKS;
3474 	/* indirect blocks */
3475 	meta_blocks = 1;
3476 	upper_limit -= ppb;
3477 	/* double indirect blocks */
3478 	if (upper_limit < ppb * ppb) {
3479 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3480 		res -= meta_blocks;
3481 		goto check_lfs;
3482 	}
3483 	meta_blocks += 1 + ppb;
3484 	upper_limit -= ppb * ppb;
3485 	/* tripple indirect blocks for the rest */
3486 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3487 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3488 	res -= meta_blocks;
3489 check_lfs:
3490 	res <<= bits;
3491 	if (res > MAX_LFS_FILESIZE)
3492 		res = MAX_LFS_FILESIZE;
3493 
3494 	return res;
3495 }
3496 
3497 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3498 				   ext4_fsblk_t logical_sb_block, int nr)
3499 {
3500 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3501 	ext4_group_t bg, first_meta_bg;
3502 	int has_super = 0;
3503 
3504 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3505 
3506 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3507 		return logical_sb_block + nr + 1;
3508 	bg = sbi->s_desc_per_block * nr;
3509 	if (ext4_bg_has_super(sb, bg))
3510 		has_super = 1;
3511 
3512 	/*
3513 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3514 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3515 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3516 	 * compensate.
3517 	 */
3518 	if (sb->s_blocksize == 1024 && nr == 0 &&
3519 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3520 		has_super++;
3521 
3522 	return (has_super + ext4_group_first_block_no(sb, bg));
3523 }
3524 
3525 /**
3526  * ext4_get_stripe_size: Get the stripe size.
3527  * @sbi: In memory super block info
3528  *
3529  * If we have specified it via mount option, then
3530  * use the mount option value. If the value specified at mount time is
3531  * greater than the blocks per group use the super block value.
3532  * If the super block value is greater than blocks per group return 0.
3533  * Allocator needs it be less than blocks per group.
3534  *
3535  */
3536 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3537 {
3538 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3539 	unsigned long stripe_width =
3540 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3541 	int ret;
3542 
3543 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3544 		ret = sbi->s_stripe;
3545 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3546 		ret = stripe_width;
3547 	else if (stride && stride <= sbi->s_blocks_per_group)
3548 		ret = stride;
3549 	else
3550 		ret = 0;
3551 
3552 	/*
3553 	 * If the stripe width is 1, this makes no sense and
3554 	 * we set it to 0 to turn off stripe handling code.
3555 	 */
3556 	if (ret <= 1)
3557 		ret = 0;
3558 
3559 	return ret;
3560 }
3561 
3562 /*
3563  * Check whether this filesystem can be mounted based on
3564  * the features present and the RDONLY/RDWR mount requested.
3565  * Returns 1 if this filesystem can be mounted as requested,
3566  * 0 if it cannot be.
3567  */
3568 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3569 {
3570 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3571 		ext4_msg(sb, KERN_ERR,
3572 			"Couldn't mount because of "
3573 			"unsupported optional features (%x)",
3574 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3575 			~EXT4_FEATURE_INCOMPAT_SUPP));
3576 		return 0;
3577 	}
3578 
3579 	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
3580 		ext4_msg(sb, KERN_ERR,
3581 			 "Filesystem with casefold feature cannot be "
3582 			 "mounted without CONFIG_UNICODE");
3583 		return 0;
3584 	}
3585 
3586 	if (readonly)
3587 		return 1;
3588 
3589 	if (ext4_has_feature_readonly(sb)) {
3590 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3591 		sb->s_flags |= SB_RDONLY;
3592 		return 1;
3593 	}
3594 
3595 	/* Check that feature set is OK for a read-write mount */
3596 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3597 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3598 			 "unsupported optional features (%x)",
3599 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3600 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3601 		return 0;
3602 	}
3603 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3604 		ext4_msg(sb, KERN_ERR,
3605 			 "Can't support bigalloc feature without "
3606 			 "extents feature\n");
3607 		return 0;
3608 	}
3609 
3610 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3611 	if (!readonly && (ext4_has_feature_quota(sb) ||
3612 			  ext4_has_feature_project(sb))) {
3613 		ext4_msg(sb, KERN_ERR,
3614 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3615 		return 0;
3616 	}
3617 #endif  /* CONFIG_QUOTA */
3618 	return 1;
3619 }
3620 
3621 /*
3622  * This function is called once a day if we have errors logged
3623  * on the file system
3624  */
3625 static void print_daily_error_info(struct timer_list *t)
3626 {
3627 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3628 	struct super_block *sb = sbi->s_sb;
3629 	struct ext4_super_block *es = sbi->s_es;
3630 
3631 	if (es->s_error_count)
3632 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3633 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3634 			 le32_to_cpu(es->s_error_count));
3635 	if (es->s_first_error_time) {
3636 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3637 		       sb->s_id,
3638 		       ext4_get_tstamp(es, s_first_error_time),
3639 		       (int) sizeof(es->s_first_error_func),
3640 		       es->s_first_error_func,
3641 		       le32_to_cpu(es->s_first_error_line));
3642 		if (es->s_first_error_ino)
3643 			printk(KERN_CONT ": inode %u",
3644 			       le32_to_cpu(es->s_first_error_ino));
3645 		if (es->s_first_error_block)
3646 			printk(KERN_CONT ": block %llu", (unsigned long long)
3647 			       le64_to_cpu(es->s_first_error_block));
3648 		printk(KERN_CONT "\n");
3649 	}
3650 	if (es->s_last_error_time) {
3651 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3652 		       sb->s_id,
3653 		       ext4_get_tstamp(es, s_last_error_time),
3654 		       (int) sizeof(es->s_last_error_func),
3655 		       es->s_last_error_func,
3656 		       le32_to_cpu(es->s_last_error_line));
3657 		if (es->s_last_error_ino)
3658 			printk(KERN_CONT ": inode %u",
3659 			       le32_to_cpu(es->s_last_error_ino));
3660 		if (es->s_last_error_block)
3661 			printk(KERN_CONT ": block %llu", (unsigned long long)
3662 			       le64_to_cpu(es->s_last_error_block));
3663 		printk(KERN_CONT "\n");
3664 	}
3665 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3666 }
3667 
3668 /* Find next suitable group and run ext4_init_inode_table */
3669 static int ext4_run_li_request(struct ext4_li_request *elr)
3670 {
3671 	struct ext4_group_desc *gdp = NULL;
3672 	struct super_block *sb = elr->lr_super;
3673 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3674 	ext4_group_t group = elr->lr_next_group;
3675 	unsigned int prefetch_ios = 0;
3676 	int ret = 0;
3677 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3678 	u64 start_time;
3679 
3680 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3681 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3682 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3683 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3684 		if (group >= elr->lr_next_group) {
3685 			ret = 1;
3686 			if (elr->lr_first_not_zeroed != ngroups &&
3687 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3688 				elr->lr_next_group = elr->lr_first_not_zeroed;
3689 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3690 				ret = 0;
3691 			}
3692 		}
3693 		return ret;
3694 	}
3695 
3696 	for (; group < ngroups; group++) {
3697 		gdp = ext4_get_group_desc(sb, group, NULL);
3698 		if (!gdp) {
3699 			ret = 1;
3700 			break;
3701 		}
3702 
3703 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3704 			break;
3705 	}
3706 
3707 	if (group >= ngroups)
3708 		ret = 1;
3709 
3710 	if (!ret) {
3711 		start_time = ktime_get_real_ns();
3712 		ret = ext4_init_inode_table(sb, group,
3713 					    elr->lr_timeout ? 0 : 1);
3714 		trace_ext4_lazy_itable_init(sb, group);
3715 		if (elr->lr_timeout == 0) {
3716 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3717 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3718 		}
3719 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3720 		elr->lr_next_group = group + 1;
3721 	}
3722 	return ret;
3723 }
3724 
3725 /*
3726  * Remove lr_request from the list_request and free the
3727  * request structure. Should be called with li_list_mtx held
3728  */
3729 static void ext4_remove_li_request(struct ext4_li_request *elr)
3730 {
3731 	if (!elr)
3732 		return;
3733 
3734 	list_del(&elr->lr_request);
3735 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3736 	kfree(elr);
3737 }
3738 
3739 static void ext4_unregister_li_request(struct super_block *sb)
3740 {
3741 	mutex_lock(&ext4_li_mtx);
3742 	if (!ext4_li_info) {
3743 		mutex_unlock(&ext4_li_mtx);
3744 		return;
3745 	}
3746 
3747 	mutex_lock(&ext4_li_info->li_list_mtx);
3748 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3749 	mutex_unlock(&ext4_li_info->li_list_mtx);
3750 	mutex_unlock(&ext4_li_mtx);
3751 }
3752 
3753 static struct task_struct *ext4_lazyinit_task;
3754 
3755 /*
3756  * This is the function where ext4lazyinit thread lives. It walks
3757  * through the request list searching for next scheduled filesystem.
3758  * When such a fs is found, run the lazy initialization request
3759  * (ext4_rn_li_request) and keep track of the time spend in this
3760  * function. Based on that time we compute next schedule time of
3761  * the request. When walking through the list is complete, compute
3762  * next waking time and put itself into sleep.
3763  */
3764 static int ext4_lazyinit_thread(void *arg)
3765 {
3766 	struct ext4_lazy_init *eli = arg;
3767 	struct list_head *pos, *n;
3768 	struct ext4_li_request *elr;
3769 	unsigned long next_wakeup, cur;
3770 
3771 	BUG_ON(NULL == eli);
3772 	set_freezable();
3773 
3774 cont_thread:
3775 	while (true) {
3776 		next_wakeup = MAX_JIFFY_OFFSET;
3777 
3778 		mutex_lock(&eli->li_list_mtx);
3779 		if (list_empty(&eli->li_request_list)) {
3780 			mutex_unlock(&eli->li_list_mtx);
3781 			goto exit_thread;
3782 		}
3783 		list_for_each_safe(pos, n, &eli->li_request_list) {
3784 			int err = 0;
3785 			int progress = 0;
3786 			elr = list_entry(pos, struct ext4_li_request,
3787 					 lr_request);
3788 
3789 			if (time_before(jiffies, elr->lr_next_sched)) {
3790 				if (time_before(elr->lr_next_sched, next_wakeup))
3791 					next_wakeup = elr->lr_next_sched;
3792 				continue;
3793 			}
3794 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3795 				if (sb_start_write_trylock(elr->lr_super)) {
3796 					progress = 1;
3797 					/*
3798 					 * We hold sb->s_umount, sb can not
3799 					 * be removed from the list, it is
3800 					 * now safe to drop li_list_mtx
3801 					 */
3802 					mutex_unlock(&eli->li_list_mtx);
3803 					err = ext4_run_li_request(elr);
3804 					sb_end_write(elr->lr_super);
3805 					mutex_lock(&eli->li_list_mtx);
3806 					n = pos->next;
3807 				}
3808 				up_read((&elr->lr_super->s_umount));
3809 			}
3810 			/* error, remove the lazy_init job */
3811 			if (err) {
3812 				ext4_remove_li_request(elr);
3813 				continue;
3814 			}
3815 			if (!progress) {
3816 				elr->lr_next_sched = jiffies +
3817 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3818 			}
3819 			if (time_before(elr->lr_next_sched, next_wakeup))
3820 				next_wakeup = elr->lr_next_sched;
3821 		}
3822 		mutex_unlock(&eli->li_list_mtx);
3823 
3824 		try_to_freeze();
3825 
3826 		cur = jiffies;
3827 		if ((time_after_eq(cur, next_wakeup)) ||
3828 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3829 			cond_resched();
3830 			continue;
3831 		}
3832 
3833 		schedule_timeout_interruptible(next_wakeup - cur);
3834 
3835 		if (kthread_should_stop()) {
3836 			ext4_clear_request_list();
3837 			goto exit_thread;
3838 		}
3839 	}
3840 
3841 exit_thread:
3842 	/*
3843 	 * It looks like the request list is empty, but we need
3844 	 * to check it under the li_list_mtx lock, to prevent any
3845 	 * additions into it, and of course we should lock ext4_li_mtx
3846 	 * to atomically free the list and ext4_li_info, because at
3847 	 * this point another ext4 filesystem could be registering
3848 	 * new one.
3849 	 */
3850 	mutex_lock(&ext4_li_mtx);
3851 	mutex_lock(&eli->li_list_mtx);
3852 	if (!list_empty(&eli->li_request_list)) {
3853 		mutex_unlock(&eli->li_list_mtx);
3854 		mutex_unlock(&ext4_li_mtx);
3855 		goto cont_thread;
3856 	}
3857 	mutex_unlock(&eli->li_list_mtx);
3858 	kfree(ext4_li_info);
3859 	ext4_li_info = NULL;
3860 	mutex_unlock(&ext4_li_mtx);
3861 
3862 	return 0;
3863 }
3864 
3865 static void ext4_clear_request_list(void)
3866 {
3867 	struct list_head *pos, *n;
3868 	struct ext4_li_request *elr;
3869 
3870 	mutex_lock(&ext4_li_info->li_list_mtx);
3871 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3872 		elr = list_entry(pos, struct ext4_li_request,
3873 				 lr_request);
3874 		ext4_remove_li_request(elr);
3875 	}
3876 	mutex_unlock(&ext4_li_info->li_list_mtx);
3877 }
3878 
3879 static int ext4_run_lazyinit_thread(void)
3880 {
3881 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3882 					 ext4_li_info, "ext4lazyinit");
3883 	if (IS_ERR(ext4_lazyinit_task)) {
3884 		int err = PTR_ERR(ext4_lazyinit_task);
3885 		ext4_clear_request_list();
3886 		kfree(ext4_li_info);
3887 		ext4_li_info = NULL;
3888 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3889 				 "initialization thread\n",
3890 				 err);
3891 		return err;
3892 	}
3893 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3894 	return 0;
3895 }
3896 
3897 /*
3898  * Check whether it make sense to run itable init. thread or not.
3899  * If there is at least one uninitialized inode table, return
3900  * corresponding group number, else the loop goes through all
3901  * groups and return total number of groups.
3902  */
3903 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3904 {
3905 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3906 	struct ext4_group_desc *gdp = NULL;
3907 
3908 	if (!ext4_has_group_desc_csum(sb))
3909 		return ngroups;
3910 
3911 	for (group = 0; group < ngroups; group++) {
3912 		gdp = ext4_get_group_desc(sb, group, NULL);
3913 		if (!gdp)
3914 			continue;
3915 
3916 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3917 			break;
3918 	}
3919 
3920 	return group;
3921 }
3922 
3923 static int ext4_li_info_new(void)
3924 {
3925 	struct ext4_lazy_init *eli = NULL;
3926 
3927 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3928 	if (!eli)
3929 		return -ENOMEM;
3930 
3931 	INIT_LIST_HEAD(&eli->li_request_list);
3932 	mutex_init(&eli->li_list_mtx);
3933 
3934 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3935 
3936 	ext4_li_info = eli;
3937 
3938 	return 0;
3939 }
3940 
3941 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3942 					    ext4_group_t start)
3943 {
3944 	struct ext4_li_request *elr;
3945 
3946 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3947 	if (!elr)
3948 		return NULL;
3949 
3950 	elr->lr_super = sb;
3951 	elr->lr_first_not_zeroed = start;
3952 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3953 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3954 		elr->lr_next_group = start;
3955 	} else {
3956 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3957 	}
3958 
3959 	/*
3960 	 * Randomize first schedule time of the request to
3961 	 * spread the inode table initialization requests
3962 	 * better.
3963 	 */
3964 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3965 	return elr;
3966 }
3967 
3968 int ext4_register_li_request(struct super_block *sb,
3969 			     ext4_group_t first_not_zeroed)
3970 {
3971 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3972 	struct ext4_li_request *elr = NULL;
3973 	ext4_group_t ngroups = sbi->s_groups_count;
3974 	int ret = 0;
3975 
3976 	mutex_lock(&ext4_li_mtx);
3977 	if (sbi->s_li_request != NULL) {
3978 		/*
3979 		 * Reset timeout so it can be computed again, because
3980 		 * s_li_wait_mult might have changed.
3981 		 */
3982 		sbi->s_li_request->lr_timeout = 0;
3983 		goto out;
3984 	}
3985 
3986 	if (sb_rdonly(sb) ||
3987 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3988 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
3989 		goto out;
3990 
3991 	elr = ext4_li_request_new(sb, first_not_zeroed);
3992 	if (!elr) {
3993 		ret = -ENOMEM;
3994 		goto out;
3995 	}
3996 
3997 	if (NULL == ext4_li_info) {
3998 		ret = ext4_li_info_new();
3999 		if (ret)
4000 			goto out;
4001 	}
4002 
4003 	mutex_lock(&ext4_li_info->li_list_mtx);
4004 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4005 	mutex_unlock(&ext4_li_info->li_list_mtx);
4006 
4007 	sbi->s_li_request = elr;
4008 	/*
4009 	 * set elr to NULL here since it has been inserted to
4010 	 * the request_list and the removal and free of it is
4011 	 * handled by ext4_clear_request_list from now on.
4012 	 */
4013 	elr = NULL;
4014 
4015 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4016 		ret = ext4_run_lazyinit_thread();
4017 		if (ret)
4018 			goto out;
4019 	}
4020 out:
4021 	mutex_unlock(&ext4_li_mtx);
4022 	if (ret)
4023 		kfree(elr);
4024 	return ret;
4025 }
4026 
4027 /*
4028  * We do not need to lock anything since this is called on
4029  * module unload.
4030  */
4031 static void ext4_destroy_lazyinit_thread(void)
4032 {
4033 	/*
4034 	 * If thread exited earlier
4035 	 * there's nothing to be done.
4036 	 */
4037 	if (!ext4_li_info || !ext4_lazyinit_task)
4038 		return;
4039 
4040 	kthread_stop(ext4_lazyinit_task);
4041 }
4042 
4043 static int set_journal_csum_feature_set(struct super_block *sb)
4044 {
4045 	int ret = 1;
4046 	int compat, incompat;
4047 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4048 
4049 	if (ext4_has_metadata_csum(sb)) {
4050 		/* journal checksum v3 */
4051 		compat = 0;
4052 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4053 	} else {
4054 		/* journal checksum v1 */
4055 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4056 		incompat = 0;
4057 	}
4058 
4059 	jbd2_journal_clear_features(sbi->s_journal,
4060 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4061 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4062 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4063 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4064 		ret = jbd2_journal_set_features(sbi->s_journal,
4065 				compat, 0,
4066 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4067 				incompat);
4068 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4069 		ret = jbd2_journal_set_features(sbi->s_journal,
4070 				compat, 0,
4071 				incompat);
4072 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4073 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4074 	} else {
4075 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4076 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4077 	}
4078 
4079 	return ret;
4080 }
4081 
4082 /*
4083  * Note: calculating the overhead so we can be compatible with
4084  * historical BSD practice is quite difficult in the face of
4085  * clusters/bigalloc.  This is because multiple metadata blocks from
4086  * different block group can end up in the same allocation cluster.
4087  * Calculating the exact overhead in the face of clustered allocation
4088  * requires either O(all block bitmaps) in memory or O(number of block
4089  * groups**2) in time.  We will still calculate the superblock for
4090  * older file systems --- and if we come across with a bigalloc file
4091  * system with zero in s_overhead_clusters the estimate will be close to
4092  * correct especially for very large cluster sizes --- but for newer
4093  * file systems, it's better to calculate this figure once at mkfs
4094  * time, and store it in the superblock.  If the superblock value is
4095  * present (even for non-bigalloc file systems), we will use it.
4096  */
4097 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4098 			  char *buf)
4099 {
4100 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4101 	struct ext4_group_desc	*gdp;
4102 	ext4_fsblk_t		first_block, last_block, b;
4103 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4104 	int			s, j, count = 0;
4105 	int			has_super = ext4_bg_has_super(sb, grp);
4106 
4107 	if (!ext4_has_feature_bigalloc(sb))
4108 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4109 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4110 			sbi->s_itb_per_group + 2);
4111 
4112 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4113 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4114 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4115 	for (i = 0; i < ngroups; i++) {
4116 		gdp = ext4_get_group_desc(sb, i, NULL);
4117 		b = ext4_block_bitmap(sb, gdp);
4118 		if (b >= first_block && b <= last_block) {
4119 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4120 			count++;
4121 		}
4122 		b = ext4_inode_bitmap(sb, gdp);
4123 		if (b >= first_block && b <= last_block) {
4124 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4125 			count++;
4126 		}
4127 		b = ext4_inode_table(sb, gdp);
4128 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4129 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4130 				int c = EXT4_B2C(sbi, b - first_block);
4131 				ext4_set_bit(c, buf);
4132 				count++;
4133 			}
4134 		if (i != grp)
4135 			continue;
4136 		s = 0;
4137 		if (ext4_bg_has_super(sb, grp)) {
4138 			ext4_set_bit(s++, buf);
4139 			count++;
4140 		}
4141 		j = ext4_bg_num_gdb(sb, grp);
4142 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4143 			ext4_error(sb, "Invalid number of block group "
4144 				   "descriptor blocks: %d", j);
4145 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4146 		}
4147 		count += j;
4148 		for (; j > 0; j--)
4149 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4150 	}
4151 	if (!count)
4152 		return 0;
4153 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4154 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4155 }
4156 
4157 /*
4158  * Compute the overhead and stash it in sbi->s_overhead
4159  */
4160 int ext4_calculate_overhead(struct super_block *sb)
4161 {
4162 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4163 	struct ext4_super_block *es = sbi->s_es;
4164 	struct inode *j_inode;
4165 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4166 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4167 	ext4_fsblk_t overhead = 0;
4168 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4169 
4170 	if (!buf)
4171 		return -ENOMEM;
4172 
4173 	/*
4174 	 * Compute the overhead (FS structures).  This is constant
4175 	 * for a given filesystem unless the number of block groups
4176 	 * changes so we cache the previous value until it does.
4177 	 */
4178 
4179 	/*
4180 	 * All of the blocks before first_data_block are overhead
4181 	 */
4182 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4183 
4184 	/*
4185 	 * Add the overhead found in each block group
4186 	 */
4187 	for (i = 0; i < ngroups; i++) {
4188 		int blks;
4189 
4190 		blks = count_overhead(sb, i, buf);
4191 		overhead += blks;
4192 		if (blks)
4193 			memset(buf, 0, PAGE_SIZE);
4194 		cond_resched();
4195 	}
4196 
4197 	/*
4198 	 * Add the internal journal blocks whether the journal has been
4199 	 * loaded or not
4200 	 */
4201 	if (sbi->s_journal && !sbi->s_journal_bdev_file)
4202 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4203 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4204 		/* j_inum for internal journal is non-zero */
4205 		j_inode = ext4_get_journal_inode(sb, j_inum);
4206 		if (!IS_ERR(j_inode)) {
4207 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4208 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4209 			iput(j_inode);
4210 		} else {
4211 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4212 		}
4213 	}
4214 	sbi->s_overhead = overhead;
4215 	smp_wmb();
4216 	free_page((unsigned long) buf);
4217 	return 0;
4218 }
4219 
4220 static void ext4_set_resv_clusters(struct super_block *sb)
4221 {
4222 	ext4_fsblk_t resv_clusters;
4223 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4224 
4225 	/*
4226 	 * There's no need to reserve anything when we aren't using extents.
4227 	 * The space estimates are exact, there are no unwritten extents,
4228 	 * hole punching doesn't need new metadata... This is needed especially
4229 	 * to keep ext2/3 backward compatibility.
4230 	 */
4231 	if (!ext4_has_feature_extents(sb))
4232 		return;
4233 	/*
4234 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4235 	 * This should cover the situations where we can not afford to run
4236 	 * out of space like for example punch hole, or converting
4237 	 * unwritten extents in delalloc path. In most cases such
4238 	 * allocation would require 1, or 2 blocks, higher numbers are
4239 	 * very rare.
4240 	 */
4241 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4242 			 sbi->s_cluster_bits);
4243 
4244 	do_div(resv_clusters, 50);
4245 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4246 
4247 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4248 }
4249 
4250 static const char *ext4_quota_mode(struct super_block *sb)
4251 {
4252 #ifdef CONFIG_QUOTA
4253 	if (!ext4_quota_capable(sb))
4254 		return "none";
4255 
4256 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4257 		return "journalled";
4258 	else
4259 		return "writeback";
4260 #else
4261 	return "disabled";
4262 #endif
4263 }
4264 
4265 static void ext4_setup_csum_trigger(struct super_block *sb,
4266 				    enum ext4_journal_trigger_type type,
4267 				    void (*trigger)(
4268 					struct jbd2_buffer_trigger_type *type,
4269 					struct buffer_head *bh,
4270 					void *mapped_data,
4271 					size_t size))
4272 {
4273 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4274 
4275 	sbi->s_journal_triggers[type].sb = sb;
4276 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4277 }
4278 
4279 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4280 {
4281 	if (!sbi)
4282 		return;
4283 
4284 	kfree(sbi->s_blockgroup_lock);
4285 	fs_put_dax(sbi->s_daxdev, NULL);
4286 	kfree(sbi);
4287 }
4288 
4289 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4290 {
4291 	struct ext4_sb_info *sbi;
4292 
4293 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4294 	if (!sbi)
4295 		return NULL;
4296 
4297 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4298 					   NULL, NULL);
4299 
4300 	sbi->s_blockgroup_lock =
4301 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4302 
4303 	if (!sbi->s_blockgroup_lock)
4304 		goto err_out;
4305 
4306 	sb->s_fs_info = sbi;
4307 	sbi->s_sb = sb;
4308 	return sbi;
4309 err_out:
4310 	fs_put_dax(sbi->s_daxdev, NULL);
4311 	kfree(sbi);
4312 	return NULL;
4313 }
4314 
4315 static void ext4_set_def_opts(struct super_block *sb,
4316 			      struct ext4_super_block *es)
4317 {
4318 	unsigned long def_mount_opts;
4319 
4320 	/* Set defaults before we parse the mount options */
4321 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4322 	set_opt(sb, INIT_INODE_TABLE);
4323 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4324 		set_opt(sb, DEBUG);
4325 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4326 		set_opt(sb, GRPID);
4327 	if (def_mount_opts & EXT4_DEFM_UID16)
4328 		set_opt(sb, NO_UID32);
4329 	/* xattr user namespace & acls are now defaulted on */
4330 	set_opt(sb, XATTR_USER);
4331 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4332 	set_opt(sb, POSIX_ACL);
4333 #endif
4334 	if (ext4_has_feature_fast_commit(sb))
4335 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4336 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4337 	if (ext4_has_metadata_csum(sb))
4338 		set_opt(sb, JOURNAL_CHECKSUM);
4339 
4340 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4341 		set_opt(sb, JOURNAL_DATA);
4342 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4343 		set_opt(sb, ORDERED_DATA);
4344 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4345 		set_opt(sb, WRITEBACK_DATA);
4346 
4347 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4348 		set_opt(sb, ERRORS_PANIC);
4349 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4350 		set_opt(sb, ERRORS_CONT);
4351 	else
4352 		set_opt(sb, ERRORS_RO);
4353 	/* block_validity enabled by default; disable with noblock_validity */
4354 	set_opt(sb, BLOCK_VALIDITY);
4355 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4356 		set_opt(sb, DISCARD);
4357 
4358 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4359 		set_opt(sb, BARRIER);
4360 
4361 	/*
4362 	 * enable delayed allocation by default
4363 	 * Use -o nodelalloc to turn it off
4364 	 */
4365 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4366 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4367 		set_opt(sb, DELALLOC);
4368 
4369 	if (sb->s_blocksize <= PAGE_SIZE)
4370 		set_opt(sb, DIOREAD_NOLOCK);
4371 }
4372 
4373 static int ext4_handle_clustersize(struct super_block *sb)
4374 {
4375 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4376 	struct ext4_super_block *es = sbi->s_es;
4377 	int clustersize;
4378 
4379 	/* Handle clustersize */
4380 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4381 	if (ext4_has_feature_bigalloc(sb)) {
4382 		if (clustersize < sb->s_blocksize) {
4383 			ext4_msg(sb, KERN_ERR,
4384 				 "cluster size (%d) smaller than "
4385 				 "block size (%lu)", clustersize, sb->s_blocksize);
4386 			return -EINVAL;
4387 		}
4388 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4389 			le32_to_cpu(es->s_log_block_size);
4390 	} else {
4391 		if (clustersize != sb->s_blocksize) {
4392 			ext4_msg(sb, KERN_ERR,
4393 				 "fragment/cluster size (%d) != "
4394 				 "block size (%lu)", clustersize, sb->s_blocksize);
4395 			return -EINVAL;
4396 		}
4397 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4398 			ext4_msg(sb, KERN_ERR,
4399 				 "#blocks per group too big: %lu",
4400 				 sbi->s_blocks_per_group);
4401 			return -EINVAL;
4402 		}
4403 		sbi->s_cluster_bits = 0;
4404 	}
4405 	sbi->s_clusters_per_group = le32_to_cpu(es->s_clusters_per_group);
4406 	if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4407 		ext4_msg(sb, KERN_ERR, "#clusters per group too big: %lu",
4408 			 sbi->s_clusters_per_group);
4409 		return -EINVAL;
4410 	}
4411 	if (sbi->s_blocks_per_group !=
4412 	    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4413 		ext4_msg(sb, KERN_ERR,
4414 			 "blocks per group (%lu) and clusters per group (%lu) inconsistent",
4415 			 sbi->s_blocks_per_group, sbi->s_clusters_per_group);
4416 		return -EINVAL;
4417 	}
4418 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4419 
4420 	/* Do we have standard group size of clustersize * 8 blocks ? */
4421 	if (sbi->s_blocks_per_group == clustersize << 3)
4422 		set_opt2(sb, STD_GROUP_SIZE);
4423 
4424 	return 0;
4425 }
4426 
4427 static void ext4_fast_commit_init(struct super_block *sb)
4428 {
4429 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4430 
4431 	/* Initialize fast commit stuff */
4432 	atomic_set(&sbi->s_fc_subtid, 0);
4433 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4434 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4435 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4436 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4437 	sbi->s_fc_bytes = 0;
4438 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4439 	sbi->s_fc_ineligible_tid = 0;
4440 	spin_lock_init(&sbi->s_fc_lock);
4441 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4442 	sbi->s_fc_replay_state.fc_regions = NULL;
4443 	sbi->s_fc_replay_state.fc_regions_size = 0;
4444 	sbi->s_fc_replay_state.fc_regions_used = 0;
4445 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4446 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4447 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4448 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4449 }
4450 
4451 static int ext4_inode_info_init(struct super_block *sb,
4452 				struct ext4_super_block *es)
4453 {
4454 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4455 
4456 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4457 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4458 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4459 	} else {
4460 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4461 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4462 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4463 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4464 				 sbi->s_first_ino);
4465 			return -EINVAL;
4466 		}
4467 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4468 		    (!is_power_of_2(sbi->s_inode_size)) ||
4469 		    (sbi->s_inode_size > sb->s_blocksize)) {
4470 			ext4_msg(sb, KERN_ERR,
4471 			       "unsupported inode size: %d",
4472 			       sbi->s_inode_size);
4473 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4474 			return -EINVAL;
4475 		}
4476 		/*
4477 		 * i_atime_extra is the last extra field available for
4478 		 * [acm]times in struct ext4_inode. Checking for that
4479 		 * field should suffice to ensure we have extra space
4480 		 * for all three.
4481 		 */
4482 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4483 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4484 			sb->s_time_gran = 1;
4485 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4486 		} else {
4487 			sb->s_time_gran = NSEC_PER_SEC;
4488 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4489 		}
4490 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4491 	}
4492 
4493 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4494 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4495 			EXT4_GOOD_OLD_INODE_SIZE;
4496 		if (ext4_has_feature_extra_isize(sb)) {
4497 			unsigned v, max = (sbi->s_inode_size -
4498 					   EXT4_GOOD_OLD_INODE_SIZE);
4499 
4500 			v = le16_to_cpu(es->s_want_extra_isize);
4501 			if (v > max) {
4502 				ext4_msg(sb, KERN_ERR,
4503 					 "bad s_want_extra_isize: %d", v);
4504 				return -EINVAL;
4505 			}
4506 			if (sbi->s_want_extra_isize < v)
4507 				sbi->s_want_extra_isize = v;
4508 
4509 			v = le16_to_cpu(es->s_min_extra_isize);
4510 			if (v > max) {
4511 				ext4_msg(sb, KERN_ERR,
4512 					 "bad s_min_extra_isize: %d", v);
4513 				return -EINVAL;
4514 			}
4515 			if (sbi->s_want_extra_isize < v)
4516 				sbi->s_want_extra_isize = v;
4517 		}
4518 	}
4519 
4520 	return 0;
4521 }
4522 
4523 #if IS_ENABLED(CONFIG_UNICODE)
4524 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4525 {
4526 	const struct ext4_sb_encodings *encoding_info;
4527 	struct unicode_map *encoding;
4528 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4529 
4530 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4531 		return 0;
4532 
4533 	encoding_info = ext4_sb_read_encoding(es);
4534 	if (!encoding_info) {
4535 		ext4_msg(sb, KERN_ERR,
4536 			"Encoding requested by superblock is unknown");
4537 		return -EINVAL;
4538 	}
4539 
4540 	encoding = utf8_load(encoding_info->version);
4541 	if (IS_ERR(encoding)) {
4542 		ext4_msg(sb, KERN_ERR,
4543 			"can't mount with superblock charset: %s-%u.%u.%u "
4544 			"not supported by the kernel. flags: 0x%x.",
4545 			encoding_info->name,
4546 			unicode_major(encoding_info->version),
4547 			unicode_minor(encoding_info->version),
4548 			unicode_rev(encoding_info->version),
4549 			encoding_flags);
4550 		return -EINVAL;
4551 	}
4552 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4553 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4554 		unicode_major(encoding_info->version),
4555 		unicode_minor(encoding_info->version),
4556 		unicode_rev(encoding_info->version),
4557 		encoding_flags);
4558 
4559 	sb->s_encoding = encoding;
4560 	sb->s_encoding_flags = encoding_flags;
4561 
4562 	return 0;
4563 }
4564 #else
4565 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4566 {
4567 	return 0;
4568 }
4569 #endif
4570 
4571 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4572 {
4573 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4574 
4575 	/* Warn if metadata_csum and gdt_csum are both set. */
4576 	if (ext4_has_feature_metadata_csum(sb) &&
4577 	    ext4_has_feature_gdt_csum(sb))
4578 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4579 			     "redundant flags; please run fsck.");
4580 
4581 	/* Check for a known checksum algorithm */
4582 	if (!ext4_verify_csum_type(sb, es)) {
4583 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4584 			 "unknown checksum algorithm.");
4585 		return -EINVAL;
4586 	}
4587 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4588 				ext4_orphan_file_block_trigger);
4589 
4590 	/* Load the checksum driver */
4591 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4592 	if (IS_ERR(sbi->s_chksum_driver)) {
4593 		int ret = PTR_ERR(sbi->s_chksum_driver);
4594 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4595 		sbi->s_chksum_driver = NULL;
4596 		return ret;
4597 	}
4598 
4599 	/* Check superblock checksum */
4600 	if (!ext4_superblock_csum_verify(sb, es)) {
4601 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4602 			 "invalid superblock checksum.  Run e2fsck?");
4603 		return -EFSBADCRC;
4604 	}
4605 
4606 	/* Precompute checksum seed for all metadata */
4607 	if (ext4_has_feature_csum_seed(sb))
4608 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4609 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4610 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4611 					       sizeof(es->s_uuid));
4612 	return 0;
4613 }
4614 
4615 static int ext4_check_feature_compatibility(struct super_block *sb,
4616 					    struct ext4_super_block *es,
4617 					    int silent)
4618 {
4619 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4620 
4621 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4622 	    (ext4_has_compat_features(sb) ||
4623 	     ext4_has_ro_compat_features(sb) ||
4624 	     ext4_has_incompat_features(sb)))
4625 		ext4_msg(sb, KERN_WARNING,
4626 		       "feature flags set on rev 0 fs, "
4627 		       "running e2fsck is recommended");
4628 
4629 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4630 		set_opt2(sb, HURD_COMPAT);
4631 		if (ext4_has_feature_64bit(sb)) {
4632 			ext4_msg(sb, KERN_ERR,
4633 				 "The Hurd can't support 64-bit file systems");
4634 			return -EINVAL;
4635 		}
4636 
4637 		/*
4638 		 * ea_inode feature uses l_i_version field which is not
4639 		 * available in HURD_COMPAT mode.
4640 		 */
4641 		if (ext4_has_feature_ea_inode(sb)) {
4642 			ext4_msg(sb, KERN_ERR,
4643 				 "ea_inode feature is not supported for Hurd");
4644 			return -EINVAL;
4645 		}
4646 	}
4647 
4648 	if (IS_EXT2_SB(sb)) {
4649 		if (ext2_feature_set_ok(sb))
4650 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4651 				 "using the ext4 subsystem");
4652 		else {
4653 			/*
4654 			 * If we're probing be silent, if this looks like
4655 			 * it's actually an ext[34] filesystem.
4656 			 */
4657 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4658 				return -EINVAL;
4659 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4660 				 "to feature incompatibilities");
4661 			return -EINVAL;
4662 		}
4663 	}
4664 
4665 	if (IS_EXT3_SB(sb)) {
4666 		if (ext3_feature_set_ok(sb))
4667 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4668 				 "using the ext4 subsystem");
4669 		else {
4670 			/*
4671 			 * If we're probing be silent, if this looks like
4672 			 * it's actually an ext4 filesystem.
4673 			 */
4674 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4675 				return -EINVAL;
4676 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4677 				 "to feature incompatibilities");
4678 			return -EINVAL;
4679 		}
4680 	}
4681 
4682 	/*
4683 	 * Check feature flags regardless of the revision level, since we
4684 	 * previously didn't change the revision level when setting the flags,
4685 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4686 	 */
4687 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4688 		return -EINVAL;
4689 
4690 	if (sbi->s_daxdev) {
4691 		if (sb->s_blocksize == PAGE_SIZE)
4692 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4693 		else
4694 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4695 	}
4696 
4697 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4698 		if (ext4_has_feature_inline_data(sb)) {
4699 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4700 					" that may contain inline data");
4701 			return -EINVAL;
4702 		}
4703 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4704 			ext4_msg(sb, KERN_ERR,
4705 				"DAX unsupported by block device.");
4706 			return -EINVAL;
4707 		}
4708 	}
4709 
4710 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4711 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4712 			 es->s_encryption_level);
4713 		return -EINVAL;
4714 	}
4715 
4716 	return 0;
4717 }
4718 
4719 static int ext4_check_geometry(struct super_block *sb,
4720 			       struct ext4_super_block *es)
4721 {
4722 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4723 	__u64 blocks_count;
4724 	int err;
4725 
4726 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4727 		ext4_msg(sb, KERN_ERR,
4728 			 "Number of reserved GDT blocks insanely large: %d",
4729 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4730 		return -EINVAL;
4731 	}
4732 	/*
4733 	 * Test whether we have more sectors than will fit in sector_t,
4734 	 * and whether the max offset is addressable by the page cache.
4735 	 */
4736 	err = generic_check_addressable(sb->s_blocksize_bits,
4737 					ext4_blocks_count(es));
4738 	if (err) {
4739 		ext4_msg(sb, KERN_ERR, "filesystem"
4740 			 " too large to mount safely on this system");
4741 		return err;
4742 	}
4743 
4744 	/* check blocks count against device size */
4745 	blocks_count = sb_bdev_nr_blocks(sb);
4746 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4747 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4748 		       "exceeds size of device (%llu blocks)",
4749 		       ext4_blocks_count(es), blocks_count);
4750 		return -EINVAL;
4751 	}
4752 
4753 	/*
4754 	 * It makes no sense for the first data block to be beyond the end
4755 	 * of the filesystem.
4756 	 */
4757 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4758 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4759 			 "block %u is beyond end of filesystem (%llu)",
4760 			 le32_to_cpu(es->s_first_data_block),
4761 			 ext4_blocks_count(es));
4762 		return -EINVAL;
4763 	}
4764 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4765 	    (sbi->s_cluster_ratio == 1)) {
4766 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4767 			 "block is 0 with a 1k block and cluster size");
4768 		return -EINVAL;
4769 	}
4770 
4771 	blocks_count = (ext4_blocks_count(es) -
4772 			le32_to_cpu(es->s_first_data_block) +
4773 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4774 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4775 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4776 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4777 		       "(block count %llu, first data block %u, "
4778 		       "blocks per group %lu)", blocks_count,
4779 		       ext4_blocks_count(es),
4780 		       le32_to_cpu(es->s_first_data_block),
4781 		       EXT4_BLOCKS_PER_GROUP(sb));
4782 		return -EINVAL;
4783 	}
4784 	sbi->s_groups_count = blocks_count;
4785 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4786 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4787 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4788 	    le32_to_cpu(es->s_inodes_count)) {
4789 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4790 			 le32_to_cpu(es->s_inodes_count),
4791 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4792 		return -EINVAL;
4793 	}
4794 
4795 	return 0;
4796 }
4797 
4798 static int ext4_group_desc_init(struct super_block *sb,
4799 				struct ext4_super_block *es,
4800 				ext4_fsblk_t logical_sb_block,
4801 				ext4_group_t *first_not_zeroed)
4802 {
4803 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4804 	unsigned int db_count;
4805 	ext4_fsblk_t block;
4806 	int i;
4807 
4808 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4809 		   EXT4_DESC_PER_BLOCK(sb);
4810 	if (ext4_has_feature_meta_bg(sb)) {
4811 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4812 			ext4_msg(sb, KERN_WARNING,
4813 				 "first meta block group too large: %u "
4814 				 "(group descriptor block count %u)",
4815 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4816 			return -EINVAL;
4817 		}
4818 	}
4819 	rcu_assign_pointer(sbi->s_group_desc,
4820 			   kvmalloc_array(db_count,
4821 					  sizeof(struct buffer_head *),
4822 					  GFP_KERNEL));
4823 	if (sbi->s_group_desc == NULL) {
4824 		ext4_msg(sb, KERN_ERR, "not enough memory");
4825 		return -ENOMEM;
4826 	}
4827 
4828 	bgl_lock_init(sbi->s_blockgroup_lock);
4829 
4830 	/* Pre-read the descriptors into the buffer cache */
4831 	for (i = 0; i < db_count; i++) {
4832 		block = descriptor_loc(sb, logical_sb_block, i);
4833 		ext4_sb_breadahead_unmovable(sb, block);
4834 	}
4835 
4836 	for (i = 0; i < db_count; i++) {
4837 		struct buffer_head *bh;
4838 
4839 		block = descriptor_loc(sb, logical_sb_block, i);
4840 		bh = ext4_sb_bread_unmovable(sb, block);
4841 		if (IS_ERR(bh)) {
4842 			ext4_msg(sb, KERN_ERR,
4843 			       "can't read group descriptor %d", i);
4844 			sbi->s_gdb_count = i;
4845 			return PTR_ERR(bh);
4846 		}
4847 		rcu_read_lock();
4848 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4849 		rcu_read_unlock();
4850 	}
4851 	sbi->s_gdb_count = db_count;
4852 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4853 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4854 		return -EFSCORRUPTED;
4855 	}
4856 
4857 	return 0;
4858 }
4859 
4860 static int ext4_load_and_init_journal(struct super_block *sb,
4861 				      struct ext4_super_block *es,
4862 				      struct ext4_fs_context *ctx)
4863 {
4864 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4865 	int err;
4866 
4867 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4868 	if (err)
4869 		return err;
4870 
4871 	if (ext4_has_feature_64bit(sb) &&
4872 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4873 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4874 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4875 		goto out;
4876 	}
4877 
4878 	if (!set_journal_csum_feature_set(sb)) {
4879 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4880 			 "feature set");
4881 		goto out;
4882 	}
4883 
4884 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4885 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4886 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4887 		ext4_msg(sb, KERN_ERR,
4888 			"Failed to set fast commit journal feature");
4889 		goto out;
4890 	}
4891 
4892 	/* We have now updated the journal if required, so we can
4893 	 * validate the data journaling mode. */
4894 	switch (test_opt(sb, DATA_FLAGS)) {
4895 	case 0:
4896 		/* No mode set, assume a default based on the journal
4897 		 * capabilities: ORDERED_DATA if the journal can
4898 		 * cope, else JOURNAL_DATA
4899 		 */
4900 		if (jbd2_journal_check_available_features
4901 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4902 			set_opt(sb, ORDERED_DATA);
4903 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4904 		} else {
4905 			set_opt(sb, JOURNAL_DATA);
4906 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4907 		}
4908 		break;
4909 
4910 	case EXT4_MOUNT_ORDERED_DATA:
4911 	case EXT4_MOUNT_WRITEBACK_DATA:
4912 		if (!jbd2_journal_check_available_features
4913 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4914 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4915 			       "requested data journaling mode");
4916 			goto out;
4917 		}
4918 		break;
4919 	default:
4920 		break;
4921 	}
4922 
4923 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4924 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4925 		ext4_msg(sb, KERN_ERR, "can't mount with "
4926 			"journal_async_commit in data=ordered mode");
4927 		goto out;
4928 	}
4929 
4930 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4931 
4932 	sbi->s_journal->j_submit_inode_data_buffers =
4933 		ext4_journal_submit_inode_data_buffers;
4934 	sbi->s_journal->j_finish_inode_data_buffers =
4935 		ext4_journal_finish_inode_data_buffers;
4936 
4937 	return 0;
4938 
4939 out:
4940 	/* flush s_sb_upd_work before destroying the journal. */
4941 	flush_work(&sbi->s_sb_upd_work);
4942 	jbd2_journal_destroy(sbi->s_journal);
4943 	sbi->s_journal = NULL;
4944 	return -EINVAL;
4945 }
4946 
4947 static int ext4_check_journal_data_mode(struct super_block *sb)
4948 {
4949 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4950 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4951 			    "data=journal disables delayed allocation, "
4952 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4953 		/* can't mount with both data=journal and dioread_nolock. */
4954 		clear_opt(sb, DIOREAD_NOLOCK);
4955 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4956 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4957 			ext4_msg(sb, KERN_ERR, "can't mount with "
4958 				 "both data=journal and delalloc");
4959 			return -EINVAL;
4960 		}
4961 		if (test_opt(sb, DAX_ALWAYS)) {
4962 			ext4_msg(sb, KERN_ERR, "can't mount with "
4963 				 "both data=journal and dax");
4964 			return -EINVAL;
4965 		}
4966 		if (ext4_has_feature_encrypt(sb)) {
4967 			ext4_msg(sb, KERN_WARNING,
4968 				 "encrypted files will use data=ordered "
4969 				 "instead of data journaling mode");
4970 		}
4971 		if (test_opt(sb, DELALLOC))
4972 			clear_opt(sb, DELALLOC);
4973 	} else {
4974 		sb->s_iflags |= SB_I_CGROUPWB;
4975 	}
4976 
4977 	return 0;
4978 }
4979 
4980 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
4981 			   int silent)
4982 {
4983 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4984 	struct ext4_super_block *es;
4985 	ext4_fsblk_t logical_sb_block;
4986 	unsigned long offset = 0;
4987 	struct buffer_head *bh;
4988 	int ret = -EINVAL;
4989 	int blocksize;
4990 
4991 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4992 	if (!blocksize) {
4993 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4994 		return -EINVAL;
4995 	}
4996 
4997 	/*
4998 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4999 	 * block sizes.  We need to calculate the offset from buffer start.
5000 	 */
5001 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5002 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5003 		offset = do_div(logical_sb_block, blocksize);
5004 	} else {
5005 		logical_sb_block = sbi->s_sb_block;
5006 	}
5007 
5008 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5009 	if (IS_ERR(bh)) {
5010 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5011 		return PTR_ERR(bh);
5012 	}
5013 	/*
5014 	 * Note: s_es must be initialized as soon as possible because
5015 	 *       some ext4 macro-instructions depend on its value
5016 	 */
5017 	es = (struct ext4_super_block *) (bh->b_data + offset);
5018 	sbi->s_es = es;
5019 	sb->s_magic = le16_to_cpu(es->s_magic);
5020 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5021 		if (!silent)
5022 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5023 		goto out;
5024 	}
5025 
5026 	if (le32_to_cpu(es->s_log_block_size) >
5027 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5028 		ext4_msg(sb, KERN_ERR,
5029 			 "Invalid log block size: %u",
5030 			 le32_to_cpu(es->s_log_block_size));
5031 		goto out;
5032 	}
5033 	if (le32_to_cpu(es->s_log_cluster_size) >
5034 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5035 		ext4_msg(sb, KERN_ERR,
5036 			 "Invalid log cluster size: %u",
5037 			 le32_to_cpu(es->s_log_cluster_size));
5038 		goto out;
5039 	}
5040 
5041 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5042 
5043 	/*
5044 	 * If the default block size is not the same as the real block size,
5045 	 * we need to reload it.
5046 	 */
5047 	if (sb->s_blocksize == blocksize) {
5048 		*lsb = logical_sb_block;
5049 		sbi->s_sbh = bh;
5050 		return 0;
5051 	}
5052 
5053 	/*
5054 	 * bh must be released before kill_bdev(), otherwise
5055 	 * it won't be freed and its page also. kill_bdev()
5056 	 * is called by sb_set_blocksize().
5057 	 */
5058 	brelse(bh);
5059 	/* Validate the filesystem blocksize */
5060 	if (!sb_set_blocksize(sb, blocksize)) {
5061 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5062 				blocksize);
5063 		bh = NULL;
5064 		goto out;
5065 	}
5066 
5067 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5068 	offset = do_div(logical_sb_block, blocksize);
5069 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5070 	if (IS_ERR(bh)) {
5071 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5072 		ret = PTR_ERR(bh);
5073 		bh = NULL;
5074 		goto out;
5075 	}
5076 	es = (struct ext4_super_block *)(bh->b_data + offset);
5077 	sbi->s_es = es;
5078 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5079 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5080 		goto out;
5081 	}
5082 	*lsb = logical_sb_block;
5083 	sbi->s_sbh = bh;
5084 	return 0;
5085 out:
5086 	brelse(bh);
5087 	return ret;
5088 }
5089 
5090 static void ext4_hash_info_init(struct super_block *sb)
5091 {
5092 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5093 	struct ext4_super_block *es = sbi->s_es;
5094 	unsigned int i;
5095 
5096 	for (i = 0; i < 4; i++)
5097 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5098 
5099 	sbi->s_def_hash_version = es->s_def_hash_version;
5100 	if (ext4_has_feature_dir_index(sb)) {
5101 		i = le32_to_cpu(es->s_flags);
5102 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5103 			sbi->s_hash_unsigned = 3;
5104 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5105 #ifdef __CHAR_UNSIGNED__
5106 			if (!sb_rdonly(sb))
5107 				es->s_flags |=
5108 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5109 			sbi->s_hash_unsigned = 3;
5110 #else
5111 			if (!sb_rdonly(sb))
5112 				es->s_flags |=
5113 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5114 #endif
5115 		}
5116 	}
5117 }
5118 
5119 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5120 {
5121 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5122 	struct ext4_super_block *es = sbi->s_es;
5123 	int has_huge_files;
5124 
5125 	has_huge_files = ext4_has_feature_huge_file(sb);
5126 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5127 						      has_huge_files);
5128 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5129 
5130 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5131 	if (ext4_has_feature_64bit(sb)) {
5132 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5133 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5134 		    !is_power_of_2(sbi->s_desc_size)) {
5135 			ext4_msg(sb, KERN_ERR,
5136 			       "unsupported descriptor size %lu",
5137 			       sbi->s_desc_size);
5138 			return -EINVAL;
5139 		}
5140 	} else
5141 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5142 
5143 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5144 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5145 
5146 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5147 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5148 		if (!silent)
5149 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5150 		return -EINVAL;
5151 	}
5152 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5153 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5154 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5155 			 sbi->s_inodes_per_group);
5156 		return -EINVAL;
5157 	}
5158 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5159 					sbi->s_inodes_per_block;
5160 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5161 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5162 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5163 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5164 
5165 	return 0;
5166 }
5167 
5168 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5169 {
5170 	struct ext4_super_block *es = NULL;
5171 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5172 	ext4_fsblk_t logical_sb_block;
5173 	struct inode *root;
5174 	int needs_recovery;
5175 	int err;
5176 	ext4_group_t first_not_zeroed;
5177 	struct ext4_fs_context *ctx = fc->fs_private;
5178 	int silent = fc->sb_flags & SB_SILENT;
5179 
5180 	/* Set defaults for the variables that will be set during parsing */
5181 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5182 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5183 
5184 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5185 	sbi->s_sectors_written_start =
5186 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5187 
5188 	err = ext4_load_super(sb, &logical_sb_block, silent);
5189 	if (err)
5190 		goto out_fail;
5191 
5192 	es = sbi->s_es;
5193 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5194 
5195 	err = ext4_init_metadata_csum(sb, es);
5196 	if (err)
5197 		goto failed_mount;
5198 
5199 	ext4_set_def_opts(sb, es);
5200 
5201 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5202 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5203 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5204 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5205 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5206 
5207 	/*
5208 	 * set default s_li_wait_mult for lazyinit, for the case there is
5209 	 * no mount option specified.
5210 	 */
5211 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5212 
5213 	err = ext4_inode_info_init(sb, es);
5214 	if (err)
5215 		goto failed_mount;
5216 
5217 	err = parse_apply_sb_mount_options(sb, ctx);
5218 	if (err < 0)
5219 		goto failed_mount;
5220 
5221 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5222 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5223 
5224 	err = ext4_check_opt_consistency(fc, sb);
5225 	if (err < 0)
5226 		goto failed_mount;
5227 
5228 	ext4_apply_options(fc, sb);
5229 
5230 	err = ext4_encoding_init(sb, es);
5231 	if (err)
5232 		goto failed_mount;
5233 
5234 	err = ext4_check_journal_data_mode(sb);
5235 	if (err)
5236 		goto failed_mount;
5237 
5238 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5239 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5240 
5241 	/* i_version is always enabled now */
5242 	sb->s_flags |= SB_I_VERSION;
5243 
5244 	err = ext4_check_feature_compatibility(sb, es, silent);
5245 	if (err)
5246 		goto failed_mount;
5247 
5248 	err = ext4_block_group_meta_init(sb, silent);
5249 	if (err)
5250 		goto failed_mount;
5251 
5252 	ext4_hash_info_init(sb);
5253 
5254 	err = ext4_handle_clustersize(sb);
5255 	if (err)
5256 		goto failed_mount;
5257 
5258 	err = ext4_check_geometry(sb, es);
5259 	if (err)
5260 		goto failed_mount;
5261 
5262 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5263 	spin_lock_init(&sbi->s_error_lock);
5264 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5265 
5266 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5267 	if (err)
5268 		goto failed_mount3;
5269 
5270 	err = ext4_es_register_shrinker(sbi);
5271 	if (err)
5272 		goto failed_mount3;
5273 
5274 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5275 	/*
5276 	 * It's hard to get stripe aligned blocks if stripe is not aligned with
5277 	 * cluster, just disable stripe and alert user to simpfy code and avoid
5278 	 * stripe aligned allocation which will rarely successes.
5279 	 */
5280 	if (sbi->s_stripe > 0 && sbi->s_cluster_ratio > 1 &&
5281 	    sbi->s_stripe % sbi->s_cluster_ratio != 0) {
5282 		ext4_msg(sb, KERN_WARNING,
5283 			 "stripe (%lu) is not aligned with cluster size (%u), "
5284 			 "stripe is disabled",
5285 			 sbi->s_stripe, sbi->s_cluster_ratio);
5286 		sbi->s_stripe = 0;
5287 	}
5288 	sbi->s_extent_max_zeroout_kb = 32;
5289 
5290 	/*
5291 	 * set up enough so that it can read an inode
5292 	 */
5293 	sb->s_op = &ext4_sops;
5294 	sb->s_export_op = &ext4_export_ops;
5295 	sb->s_xattr = ext4_xattr_handlers;
5296 #ifdef CONFIG_FS_ENCRYPTION
5297 	sb->s_cop = &ext4_cryptops;
5298 #endif
5299 #ifdef CONFIG_FS_VERITY
5300 	sb->s_vop = &ext4_verityops;
5301 #endif
5302 #ifdef CONFIG_QUOTA
5303 	sb->dq_op = &ext4_quota_operations;
5304 	if (ext4_has_feature_quota(sb))
5305 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5306 	else
5307 		sb->s_qcop = &ext4_qctl_operations;
5308 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5309 #endif
5310 	super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));
5311 	super_set_sysfs_name_bdev(sb);
5312 
5313 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5314 	mutex_init(&sbi->s_orphan_lock);
5315 
5316 	ext4_fast_commit_init(sb);
5317 
5318 	sb->s_root = NULL;
5319 
5320 	needs_recovery = (es->s_last_orphan != 0 ||
5321 			  ext4_has_feature_orphan_present(sb) ||
5322 			  ext4_has_feature_journal_needs_recovery(sb));
5323 
5324 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5325 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5326 		if (err)
5327 			goto failed_mount3a;
5328 	}
5329 
5330 	err = -EINVAL;
5331 	/*
5332 	 * The first inode we look at is the journal inode.  Don't try
5333 	 * root first: it may be modified in the journal!
5334 	 */
5335 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5336 		err = ext4_load_and_init_journal(sb, es, ctx);
5337 		if (err)
5338 			goto failed_mount3a;
5339 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5340 		   ext4_has_feature_journal_needs_recovery(sb)) {
5341 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5342 		       "suppressed and not mounted read-only");
5343 		goto failed_mount3a;
5344 	} else {
5345 		/* Nojournal mode, all journal mount options are illegal */
5346 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5347 			ext4_msg(sb, KERN_ERR, "can't mount with "
5348 				 "journal_async_commit, fs mounted w/o journal");
5349 			goto failed_mount3a;
5350 		}
5351 
5352 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5353 			ext4_msg(sb, KERN_ERR, "can't mount with "
5354 				 "journal_checksum, fs mounted w/o journal");
5355 			goto failed_mount3a;
5356 		}
5357 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5358 			ext4_msg(sb, KERN_ERR, "can't mount with "
5359 				 "commit=%lu, fs mounted w/o journal",
5360 				 sbi->s_commit_interval / HZ);
5361 			goto failed_mount3a;
5362 		}
5363 		if (EXT4_MOUNT_DATA_FLAGS &
5364 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5365 			ext4_msg(sb, KERN_ERR, "can't mount with "
5366 				 "data=, fs mounted w/o journal");
5367 			goto failed_mount3a;
5368 		}
5369 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5370 		clear_opt(sb, JOURNAL_CHECKSUM);
5371 		clear_opt(sb, DATA_FLAGS);
5372 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5373 		sbi->s_journal = NULL;
5374 		needs_recovery = 0;
5375 	}
5376 
5377 	if (!test_opt(sb, NO_MBCACHE)) {
5378 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5379 		if (!sbi->s_ea_block_cache) {
5380 			ext4_msg(sb, KERN_ERR,
5381 				 "Failed to create ea_block_cache");
5382 			err = -EINVAL;
5383 			goto failed_mount_wq;
5384 		}
5385 
5386 		if (ext4_has_feature_ea_inode(sb)) {
5387 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5388 			if (!sbi->s_ea_inode_cache) {
5389 				ext4_msg(sb, KERN_ERR,
5390 					 "Failed to create ea_inode_cache");
5391 				err = -EINVAL;
5392 				goto failed_mount_wq;
5393 			}
5394 		}
5395 	}
5396 
5397 	/*
5398 	 * Get the # of file system overhead blocks from the
5399 	 * superblock if present.
5400 	 */
5401 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5402 	/* ignore the precalculated value if it is ridiculous */
5403 	if (sbi->s_overhead > ext4_blocks_count(es))
5404 		sbi->s_overhead = 0;
5405 	/*
5406 	 * If the bigalloc feature is not enabled recalculating the
5407 	 * overhead doesn't take long, so we might as well just redo
5408 	 * it to make sure we are using the correct value.
5409 	 */
5410 	if (!ext4_has_feature_bigalloc(sb))
5411 		sbi->s_overhead = 0;
5412 	if (sbi->s_overhead == 0) {
5413 		err = ext4_calculate_overhead(sb);
5414 		if (err)
5415 			goto failed_mount_wq;
5416 	}
5417 
5418 	/*
5419 	 * The maximum number of concurrent works can be high and
5420 	 * concurrency isn't really necessary.  Limit it to 1.
5421 	 */
5422 	EXT4_SB(sb)->rsv_conversion_wq =
5423 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5424 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5425 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5426 		err = -ENOMEM;
5427 		goto failed_mount4;
5428 	}
5429 
5430 	/*
5431 	 * The jbd2_journal_load will have done any necessary log recovery,
5432 	 * so we can safely mount the rest of the filesystem now.
5433 	 */
5434 
5435 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5436 	if (IS_ERR(root)) {
5437 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5438 		err = PTR_ERR(root);
5439 		root = NULL;
5440 		goto failed_mount4;
5441 	}
5442 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5443 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5444 		iput(root);
5445 		err = -EFSCORRUPTED;
5446 		goto failed_mount4;
5447 	}
5448 
5449 	generic_set_sb_d_ops(sb);
5450 	sb->s_root = d_make_root(root);
5451 	if (!sb->s_root) {
5452 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5453 		err = -ENOMEM;
5454 		goto failed_mount4;
5455 	}
5456 
5457 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5458 	if (err == -EROFS) {
5459 		sb->s_flags |= SB_RDONLY;
5460 	} else if (err)
5461 		goto failed_mount4a;
5462 
5463 	ext4_set_resv_clusters(sb);
5464 
5465 	if (test_opt(sb, BLOCK_VALIDITY)) {
5466 		err = ext4_setup_system_zone(sb);
5467 		if (err) {
5468 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5469 				 "zone (%d)", err);
5470 			goto failed_mount4a;
5471 		}
5472 	}
5473 	ext4_fc_replay_cleanup(sb);
5474 
5475 	ext4_ext_init(sb);
5476 
5477 	/*
5478 	 * Enable optimize_scan if number of groups is > threshold. This can be
5479 	 * turned off by passing "mb_optimize_scan=0". This can also be
5480 	 * turned on forcefully by passing "mb_optimize_scan=1".
5481 	 */
5482 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5483 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5484 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5485 		else
5486 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5487 	}
5488 
5489 	err = ext4_mb_init(sb);
5490 	if (err) {
5491 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5492 			 err);
5493 		goto failed_mount5;
5494 	}
5495 
5496 	/*
5497 	 * We can only set up the journal commit callback once
5498 	 * mballoc is initialized
5499 	 */
5500 	if (sbi->s_journal)
5501 		sbi->s_journal->j_commit_callback =
5502 			ext4_journal_commit_callback;
5503 
5504 	err = ext4_percpu_param_init(sbi);
5505 	if (err)
5506 		goto failed_mount6;
5507 
5508 	if (ext4_has_feature_flex_bg(sb))
5509 		if (!ext4_fill_flex_info(sb)) {
5510 			ext4_msg(sb, KERN_ERR,
5511 			       "unable to initialize "
5512 			       "flex_bg meta info!");
5513 			err = -ENOMEM;
5514 			goto failed_mount6;
5515 		}
5516 
5517 	err = ext4_register_li_request(sb, first_not_zeroed);
5518 	if (err)
5519 		goto failed_mount6;
5520 
5521 	err = ext4_init_orphan_info(sb);
5522 	if (err)
5523 		goto failed_mount7;
5524 #ifdef CONFIG_QUOTA
5525 	/* Enable quota usage during mount. */
5526 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5527 		err = ext4_enable_quotas(sb);
5528 		if (err)
5529 			goto failed_mount8;
5530 	}
5531 #endif  /* CONFIG_QUOTA */
5532 
5533 	/*
5534 	 * Save the original bdev mapping's wb_err value which could be
5535 	 * used to detect the metadata async write error.
5536 	 */
5537 	spin_lock_init(&sbi->s_bdev_wb_lock);
5538 	errseq_check_and_advance(&sb->s_bdev->bd_mapping->wb_err,
5539 				 &sbi->s_bdev_wb_err);
5540 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5541 	ext4_orphan_cleanup(sb, es);
5542 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5543 	/*
5544 	 * Update the checksum after updating free space/inode counters and
5545 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5546 	 * checksum in the buffer cache until it is written out and
5547 	 * e2fsprogs programs trying to open a file system immediately
5548 	 * after it is mounted can fail.
5549 	 */
5550 	ext4_superblock_csum_set(sb);
5551 	if (needs_recovery) {
5552 		ext4_msg(sb, KERN_INFO, "recovery complete");
5553 		err = ext4_mark_recovery_complete(sb, es);
5554 		if (err)
5555 			goto failed_mount9;
5556 	}
5557 
5558 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5559 		ext4_msg(sb, KERN_WARNING,
5560 			 "mounting with \"discard\" option, but the device does not support discard");
5561 
5562 	if (es->s_error_count)
5563 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5564 
5565 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5566 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5567 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5568 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5569 	atomic_set(&sbi->s_warning_count, 0);
5570 	atomic_set(&sbi->s_msg_count, 0);
5571 
5572 	/* Register sysfs after all initializations are complete. */
5573 	err = ext4_register_sysfs(sb);
5574 	if (err)
5575 		goto failed_mount9;
5576 
5577 	return 0;
5578 
5579 failed_mount9:
5580 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5581 failed_mount8: __maybe_unused
5582 	ext4_release_orphan_info(sb);
5583 failed_mount7:
5584 	ext4_unregister_li_request(sb);
5585 failed_mount6:
5586 	ext4_mb_release(sb);
5587 	ext4_flex_groups_free(sbi);
5588 	ext4_percpu_param_destroy(sbi);
5589 failed_mount5:
5590 	ext4_ext_release(sb);
5591 	ext4_release_system_zone(sb);
5592 failed_mount4a:
5593 	dput(sb->s_root);
5594 	sb->s_root = NULL;
5595 failed_mount4:
5596 	ext4_msg(sb, KERN_ERR, "mount failed");
5597 	if (EXT4_SB(sb)->rsv_conversion_wq)
5598 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5599 failed_mount_wq:
5600 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5601 	sbi->s_ea_inode_cache = NULL;
5602 
5603 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5604 	sbi->s_ea_block_cache = NULL;
5605 
5606 	if (sbi->s_journal) {
5607 		/* flush s_sb_upd_work before journal destroy. */
5608 		flush_work(&sbi->s_sb_upd_work);
5609 		jbd2_journal_destroy(sbi->s_journal);
5610 		sbi->s_journal = NULL;
5611 	}
5612 failed_mount3a:
5613 	ext4_es_unregister_shrinker(sbi);
5614 failed_mount3:
5615 	/* flush s_sb_upd_work before sbi destroy */
5616 	flush_work(&sbi->s_sb_upd_work);
5617 	del_timer_sync(&sbi->s_err_report);
5618 	ext4_stop_mmpd(sbi);
5619 	ext4_group_desc_free(sbi);
5620 failed_mount:
5621 	if (sbi->s_chksum_driver)
5622 		crypto_free_shash(sbi->s_chksum_driver);
5623 
5624 #if IS_ENABLED(CONFIG_UNICODE)
5625 	utf8_unload(sb->s_encoding);
5626 #endif
5627 
5628 #ifdef CONFIG_QUOTA
5629 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5630 		kfree(get_qf_name(sb, sbi, i));
5631 #endif
5632 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5633 	brelse(sbi->s_sbh);
5634 	if (sbi->s_journal_bdev_file) {
5635 		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
5636 		bdev_fput(sbi->s_journal_bdev_file);
5637 	}
5638 out_fail:
5639 	invalidate_bdev(sb->s_bdev);
5640 	sb->s_fs_info = NULL;
5641 	return err;
5642 }
5643 
5644 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5645 {
5646 	struct ext4_fs_context *ctx = fc->fs_private;
5647 	struct ext4_sb_info *sbi;
5648 	const char *descr;
5649 	int ret;
5650 
5651 	sbi = ext4_alloc_sbi(sb);
5652 	if (!sbi)
5653 		return -ENOMEM;
5654 
5655 	fc->s_fs_info = sbi;
5656 
5657 	/* Cleanup superblock name */
5658 	strreplace(sb->s_id, '/', '!');
5659 
5660 	sbi->s_sb_block = 1;	/* Default super block location */
5661 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5662 		sbi->s_sb_block = ctx->s_sb_block;
5663 
5664 	ret = __ext4_fill_super(fc, sb);
5665 	if (ret < 0)
5666 		goto free_sbi;
5667 
5668 	if (sbi->s_journal) {
5669 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5670 			descr = " journalled data mode";
5671 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5672 			descr = " ordered data mode";
5673 		else
5674 			descr = " writeback data mode";
5675 	} else
5676 		descr = "out journal";
5677 
5678 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5679 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5680 			 "Quota mode: %s.", &sb->s_uuid,
5681 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5682 			 ext4_quota_mode(sb));
5683 
5684 	/* Update the s_overhead_clusters if necessary */
5685 	ext4_update_overhead(sb, false);
5686 	return 0;
5687 
5688 free_sbi:
5689 	ext4_free_sbi(sbi);
5690 	fc->s_fs_info = NULL;
5691 	return ret;
5692 }
5693 
5694 static int ext4_get_tree(struct fs_context *fc)
5695 {
5696 	return get_tree_bdev(fc, ext4_fill_super);
5697 }
5698 
5699 /*
5700  * Setup any per-fs journal parameters now.  We'll do this both on
5701  * initial mount, once the journal has been initialised but before we've
5702  * done any recovery; and again on any subsequent remount.
5703  */
5704 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5705 {
5706 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5707 
5708 	journal->j_commit_interval = sbi->s_commit_interval;
5709 	journal->j_min_batch_time = sbi->s_min_batch_time;
5710 	journal->j_max_batch_time = sbi->s_max_batch_time;
5711 	ext4_fc_init(sb, journal);
5712 
5713 	write_lock(&journal->j_state_lock);
5714 	if (test_opt(sb, BARRIER))
5715 		journal->j_flags |= JBD2_BARRIER;
5716 	else
5717 		journal->j_flags &= ~JBD2_BARRIER;
5718 	if (test_opt(sb, DATA_ERR_ABORT))
5719 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5720 	else
5721 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5722 	/*
5723 	 * Always enable journal cycle record option, letting the journal
5724 	 * records log transactions continuously between each mount.
5725 	 */
5726 	journal->j_flags |= JBD2_CYCLE_RECORD;
5727 	write_unlock(&journal->j_state_lock);
5728 }
5729 
5730 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5731 					     unsigned int journal_inum)
5732 {
5733 	struct inode *journal_inode;
5734 
5735 	/*
5736 	 * Test for the existence of a valid inode on disk.  Bad things
5737 	 * happen if we iget() an unused inode, as the subsequent iput()
5738 	 * will try to delete it.
5739 	 */
5740 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5741 	if (IS_ERR(journal_inode)) {
5742 		ext4_msg(sb, KERN_ERR, "no journal found");
5743 		return ERR_CAST(journal_inode);
5744 	}
5745 	if (!journal_inode->i_nlink) {
5746 		make_bad_inode(journal_inode);
5747 		iput(journal_inode);
5748 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5749 		return ERR_PTR(-EFSCORRUPTED);
5750 	}
5751 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5752 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5753 		iput(journal_inode);
5754 		return ERR_PTR(-EFSCORRUPTED);
5755 	}
5756 
5757 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5758 		  journal_inode, journal_inode->i_size);
5759 	return journal_inode;
5760 }
5761 
5762 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5763 {
5764 	struct ext4_map_blocks map;
5765 	int ret;
5766 
5767 	if (journal->j_inode == NULL)
5768 		return 0;
5769 
5770 	map.m_lblk = *block;
5771 	map.m_len = 1;
5772 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5773 	if (ret <= 0) {
5774 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5775 			 "journal bmap failed: block %llu ret %d\n",
5776 			 *block, ret);
5777 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5778 		return ret;
5779 	}
5780 	*block = map.m_pblk;
5781 	return 0;
5782 }
5783 
5784 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5785 					  unsigned int journal_inum)
5786 {
5787 	struct inode *journal_inode;
5788 	journal_t *journal;
5789 
5790 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5791 	if (IS_ERR(journal_inode))
5792 		return ERR_CAST(journal_inode);
5793 
5794 	journal = jbd2_journal_init_inode(journal_inode);
5795 	if (IS_ERR(journal)) {
5796 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5797 		iput(journal_inode);
5798 		return ERR_CAST(journal);
5799 	}
5800 	journal->j_private = sb;
5801 	journal->j_bmap = ext4_journal_bmap;
5802 	ext4_init_journal_params(sb, journal);
5803 	return journal;
5804 }
5805 
5806 static struct file *ext4_get_journal_blkdev(struct super_block *sb,
5807 					dev_t j_dev, ext4_fsblk_t *j_start,
5808 					ext4_fsblk_t *j_len)
5809 {
5810 	struct buffer_head *bh;
5811 	struct block_device *bdev;
5812 	struct file *bdev_file;
5813 	int hblock, blocksize;
5814 	ext4_fsblk_t sb_block;
5815 	unsigned long offset;
5816 	struct ext4_super_block *es;
5817 	int errno;
5818 
5819 	bdev_file = bdev_file_open_by_dev(j_dev,
5820 		BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
5821 		sb, &fs_holder_ops);
5822 	if (IS_ERR(bdev_file)) {
5823 		ext4_msg(sb, KERN_ERR,
5824 			 "failed to open journal device unknown-block(%u,%u) %ld",
5825 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev_file));
5826 		return bdev_file;
5827 	}
5828 
5829 	bdev = file_bdev(bdev_file);
5830 	blocksize = sb->s_blocksize;
5831 	hblock = bdev_logical_block_size(bdev);
5832 	if (blocksize < hblock) {
5833 		ext4_msg(sb, KERN_ERR,
5834 			"blocksize too small for journal device");
5835 		errno = -EINVAL;
5836 		goto out_bdev;
5837 	}
5838 
5839 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5840 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5841 	set_blocksize(bdev_file, blocksize);
5842 	bh = __bread(bdev, sb_block, blocksize);
5843 	if (!bh) {
5844 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5845 		       "external journal");
5846 		errno = -EINVAL;
5847 		goto out_bdev;
5848 	}
5849 
5850 	es = (struct ext4_super_block *) (bh->b_data + offset);
5851 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5852 	    !(le32_to_cpu(es->s_feature_incompat) &
5853 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5854 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
5855 		errno = -EFSCORRUPTED;
5856 		goto out_bh;
5857 	}
5858 
5859 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5860 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5861 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5862 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
5863 		errno = -EFSCORRUPTED;
5864 		goto out_bh;
5865 	}
5866 
5867 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5868 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5869 		errno = -EFSCORRUPTED;
5870 		goto out_bh;
5871 	}
5872 
5873 	*j_start = sb_block + 1;
5874 	*j_len = ext4_blocks_count(es);
5875 	brelse(bh);
5876 	return bdev_file;
5877 
5878 out_bh:
5879 	brelse(bh);
5880 out_bdev:
5881 	bdev_fput(bdev_file);
5882 	return ERR_PTR(errno);
5883 }
5884 
5885 static journal_t *ext4_open_dev_journal(struct super_block *sb,
5886 					dev_t j_dev)
5887 {
5888 	journal_t *journal;
5889 	ext4_fsblk_t j_start;
5890 	ext4_fsblk_t j_len;
5891 	struct file *bdev_file;
5892 	int errno = 0;
5893 
5894 	bdev_file = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
5895 	if (IS_ERR(bdev_file))
5896 		return ERR_CAST(bdev_file);
5897 
5898 	journal = jbd2_journal_init_dev(file_bdev(bdev_file), sb->s_bdev, j_start,
5899 					j_len, sb->s_blocksize);
5900 	if (IS_ERR(journal)) {
5901 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5902 		errno = PTR_ERR(journal);
5903 		goto out_bdev;
5904 	}
5905 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5906 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5907 					"user (unsupported) - %d",
5908 			be32_to_cpu(journal->j_superblock->s_nr_users));
5909 		errno = -EINVAL;
5910 		goto out_journal;
5911 	}
5912 	journal->j_private = sb;
5913 	EXT4_SB(sb)->s_journal_bdev_file = bdev_file;
5914 	ext4_init_journal_params(sb, journal);
5915 	return journal;
5916 
5917 out_journal:
5918 	jbd2_journal_destroy(journal);
5919 out_bdev:
5920 	bdev_fput(bdev_file);
5921 	return ERR_PTR(errno);
5922 }
5923 
5924 static int ext4_load_journal(struct super_block *sb,
5925 			     struct ext4_super_block *es,
5926 			     unsigned long journal_devnum)
5927 {
5928 	journal_t *journal;
5929 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5930 	dev_t journal_dev;
5931 	int err = 0;
5932 	int really_read_only;
5933 	int journal_dev_ro;
5934 
5935 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5936 		return -EFSCORRUPTED;
5937 
5938 	if (journal_devnum &&
5939 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5940 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5941 			"numbers have changed");
5942 		journal_dev = new_decode_dev(journal_devnum);
5943 	} else
5944 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5945 
5946 	if (journal_inum && journal_dev) {
5947 		ext4_msg(sb, KERN_ERR,
5948 			 "filesystem has both journal inode and journal device!");
5949 		return -EINVAL;
5950 	}
5951 
5952 	if (journal_inum) {
5953 		journal = ext4_open_inode_journal(sb, journal_inum);
5954 		if (IS_ERR(journal))
5955 			return PTR_ERR(journal);
5956 	} else {
5957 		journal = ext4_open_dev_journal(sb, journal_dev);
5958 		if (IS_ERR(journal))
5959 			return PTR_ERR(journal);
5960 	}
5961 
5962 	journal_dev_ro = bdev_read_only(journal->j_dev);
5963 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5964 
5965 	if (journal_dev_ro && !sb_rdonly(sb)) {
5966 		ext4_msg(sb, KERN_ERR,
5967 			 "journal device read-only, try mounting with '-o ro'");
5968 		err = -EROFS;
5969 		goto err_out;
5970 	}
5971 
5972 	/*
5973 	 * Are we loading a blank journal or performing recovery after a
5974 	 * crash?  For recovery, we need to check in advance whether we
5975 	 * can get read-write access to the device.
5976 	 */
5977 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5978 		if (sb_rdonly(sb)) {
5979 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5980 					"required on readonly filesystem");
5981 			if (really_read_only) {
5982 				ext4_msg(sb, KERN_ERR, "write access "
5983 					"unavailable, cannot proceed "
5984 					"(try mounting with noload)");
5985 				err = -EROFS;
5986 				goto err_out;
5987 			}
5988 			ext4_msg(sb, KERN_INFO, "write access will "
5989 			       "be enabled during recovery");
5990 		}
5991 	}
5992 
5993 	if (!(journal->j_flags & JBD2_BARRIER))
5994 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5995 
5996 	if (!ext4_has_feature_journal_needs_recovery(sb))
5997 		err = jbd2_journal_wipe(journal, !really_read_only);
5998 	if (!err) {
5999 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6000 		__le16 orig_state;
6001 		bool changed = false;
6002 
6003 		if (save)
6004 			memcpy(save, ((char *) es) +
6005 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6006 		err = jbd2_journal_load(journal);
6007 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6008 				   save, EXT4_S_ERR_LEN)) {
6009 			memcpy(((char *) es) + EXT4_S_ERR_START,
6010 			       save, EXT4_S_ERR_LEN);
6011 			changed = true;
6012 		}
6013 		kfree(save);
6014 		orig_state = es->s_state;
6015 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6016 					   EXT4_ERROR_FS);
6017 		if (orig_state != es->s_state)
6018 			changed = true;
6019 		/* Write out restored error information to the superblock */
6020 		if (changed && !really_read_only) {
6021 			int err2;
6022 			err2 = ext4_commit_super(sb);
6023 			err = err ? : err2;
6024 		}
6025 	}
6026 
6027 	if (err) {
6028 		ext4_msg(sb, KERN_ERR, "error loading journal");
6029 		goto err_out;
6030 	}
6031 
6032 	EXT4_SB(sb)->s_journal = journal;
6033 	err = ext4_clear_journal_err(sb, es);
6034 	if (err) {
6035 		EXT4_SB(sb)->s_journal = NULL;
6036 		jbd2_journal_destroy(journal);
6037 		return err;
6038 	}
6039 
6040 	if (!really_read_only && journal_devnum &&
6041 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6042 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6043 		ext4_commit_super(sb);
6044 	}
6045 	if (!really_read_only && journal_inum &&
6046 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6047 		es->s_journal_inum = cpu_to_le32(journal_inum);
6048 		ext4_commit_super(sb);
6049 	}
6050 
6051 	return 0;
6052 
6053 err_out:
6054 	jbd2_journal_destroy(journal);
6055 	return err;
6056 }
6057 
6058 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6059 static void ext4_update_super(struct super_block *sb)
6060 {
6061 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6062 	struct ext4_super_block *es = sbi->s_es;
6063 	struct buffer_head *sbh = sbi->s_sbh;
6064 
6065 	lock_buffer(sbh);
6066 	/*
6067 	 * If the file system is mounted read-only, don't update the
6068 	 * superblock write time.  This avoids updating the superblock
6069 	 * write time when we are mounting the root file system
6070 	 * read/only but we need to replay the journal; at that point,
6071 	 * for people who are east of GMT and who make their clock
6072 	 * tick in localtime for Windows bug-for-bug compatibility,
6073 	 * the clock is set in the future, and this will cause e2fsck
6074 	 * to complain and force a full file system check.
6075 	 */
6076 	if (!sb_rdonly(sb))
6077 		ext4_update_tstamp(es, s_wtime);
6078 	es->s_kbytes_written =
6079 		cpu_to_le64(sbi->s_kbytes_written +
6080 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6081 		      sbi->s_sectors_written_start) >> 1));
6082 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6083 		ext4_free_blocks_count_set(es,
6084 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6085 				&sbi->s_freeclusters_counter)));
6086 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6087 		es->s_free_inodes_count =
6088 			cpu_to_le32(percpu_counter_sum_positive(
6089 				&sbi->s_freeinodes_counter));
6090 	/* Copy error information to the on-disk superblock */
6091 	spin_lock(&sbi->s_error_lock);
6092 	if (sbi->s_add_error_count > 0) {
6093 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6094 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6095 			__ext4_update_tstamp(&es->s_first_error_time,
6096 					     &es->s_first_error_time_hi,
6097 					     sbi->s_first_error_time);
6098 			strtomem_pad(es->s_first_error_func,
6099 				     sbi->s_first_error_func, 0);
6100 			es->s_first_error_line =
6101 				cpu_to_le32(sbi->s_first_error_line);
6102 			es->s_first_error_ino =
6103 				cpu_to_le32(sbi->s_first_error_ino);
6104 			es->s_first_error_block =
6105 				cpu_to_le64(sbi->s_first_error_block);
6106 			es->s_first_error_errcode =
6107 				ext4_errno_to_code(sbi->s_first_error_code);
6108 		}
6109 		__ext4_update_tstamp(&es->s_last_error_time,
6110 				     &es->s_last_error_time_hi,
6111 				     sbi->s_last_error_time);
6112 		strtomem_pad(es->s_last_error_func, sbi->s_last_error_func, 0);
6113 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6114 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6115 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6116 		es->s_last_error_errcode =
6117 				ext4_errno_to_code(sbi->s_last_error_code);
6118 		/*
6119 		 * Start the daily error reporting function if it hasn't been
6120 		 * started already
6121 		 */
6122 		if (!es->s_error_count)
6123 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6124 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6125 		sbi->s_add_error_count = 0;
6126 	}
6127 	spin_unlock(&sbi->s_error_lock);
6128 
6129 	ext4_superblock_csum_set(sb);
6130 	unlock_buffer(sbh);
6131 }
6132 
6133 static int ext4_commit_super(struct super_block *sb)
6134 {
6135 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6136 
6137 	if (!sbh)
6138 		return -EINVAL;
6139 
6140 	ext4_update_super(sb);
6141 
6142 	lock_buffer(sbh);
6143 	/* Buffer got discarded which means block device got invalidated */
6144 	if (!buffer_mapped(sbh)) {
6145 		unlock_buffer(sbh);
6146 		return -EIO;
6147 	}
6148 
6149 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6150 		/*
6151 		 * Oh, dear.  A previous attempt to write the
6152 		 * superblock failed.  This could happen because the
6153 		 * USB device was yanked out.  Or it could happen to
6154 		 * be a transient write error and maybe the block will
6155 		 * be remapped.  Nothing we can do but to retry the
6156 		 * write and hope for the best.
6157 		 */
6158 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6159 		       "superblock detected");
6160 		clear_buffer_write_io_error(sbh);
6161 		set_buffer_uptodate(sbh);
6162 	}
6163 	get_bh(sbh);
6164 	/* Clear potential dirty bit if it was journalled update */
6165 	clear_buffer_dirty(sbh);
6166 	sbh->b_end_io = end_buffer_write_sync;
6167 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6168 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6169 	wait_on_buffer(sbh);
6170 	if (buffer_write_io_error(sbh)) {
6171 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6172 		       "superblock");
6173 		clear_buffer_write_io_error(sbh);
6174 		set_buffer_uptodate(sbh);
6175 		return -EIO;
6176 	}
6177 	return 0;
6178 }
6179 
6180 /*
6181  * Have we just finished recovery?  If so, and if we are mounting (or
6182  * remounting) the filesystem readonly, then we will end up with a
6183  * consistent fs on disk.  Record that fact.
6184  */
6185 static int ext4_mark_recovery_complete(struct super_block *sb,
6186 				       struct ext4_super_block *es)
6187 {
6188 	int err;
6189 	journal_t *journal = EXT4_SB(sb)->s_journal;
6190 
6191 	if (!ext4_has_feature_journal(sb)) {
6192 		if (journal != NULL) {
6193 			ext4_error(sb, "Journal got removed while the fs was "
6194 				   "mounted!");
6195 			return -EFSCORRUPTED;
6196 		}
6197 		return 0;
6198 	}
6199 	jbd2_journal_lock_updates(journal);
6200 	err = jbd2_journal_flush(journal, 0);
6201 	if (err < 0)
6202 		goto out;
6203 
6204 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6205 	    ext4_has_feature_orphan_present(sb))) {
6206 		if (!ext4_orphan_file_empty(sb)) {
6207 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6208 			err = -EFSCORRUPTED;
6209 			goto out;
6210 		}
6211 		ext4_clear_feature_journal_needs_recovery(sb);
6212 		ext4_clear_feature_orphan_present(sb);
6213 		ext4_commit_super(sb);
6214 	}
6215 out:
6216 	jbd2_journal_unlock_updates(journal);
6217 	return err;
6218 }
6219 
6220 /*
6221  * If we are mounting (or read-write remounting) a filesystem whose journal
6222  * has recorded an error from a previous lifetime, move that error to the
6223  * main filesystem now.
6224  */
6225 static int ext4_clear_journal_err(struct super_block *sb,
6226 				   struct ext4_super_block *es)
6227 {
6228 	journal_t *journal;
6229 	int j_errno;
6230 	const char *errstr;
6231 
6232 	if (!ext4_has_feature_journal(sb)) {
6233 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6234 		return -EFSCORRUPTED;
6235 	}
6236 
6237 	journal = EXT4_SB(sb)->s_journal;
6238 
6239 	/*
6240 	 * Now check for any error status which may have been recorded in the
6241 	 * journal by a prior ext4_error() or ext4_abort()
6242 	 */
6243 
6244 	j_errno = jbd2_journal_errno(journal);
6245 	if (j_errno) {
6246 		char nbuf[16];
6247 
6248 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6249 		ext4_warning(sb, "Filesystem error recorded "
6250 			     "from previous mount: %s", errstr);
6251 
6252 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6253 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6254 		j_errno = ext4_commit_super(sb);
6255 		if (j_errno)
6256 			return j_errno;
6257 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6258 
6259 		jbd2_journal_clear_err(journal);
6260 		jbd2_journal_update_sb_errno(journal);
6261 	}
6262 	return 0;
6263 }
6264 
6265 /*
6266  * Force the running and committing transactions to commit,
6267  * and wait on the commit.
6268  */
6269 int ext4_force_commit(struct super_block *sb)
6270 {
6271 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6272 }
6273 
6274 static int ext4_sync_fs(struct super_block *sb, int wait)
6275 {
6276 	int ret = 0;
6277 	tid_t target;
6278 	bool needs_barrier = false;
6279 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6280 
6281 	if (unlikely(ext4_forced_shutdown(sb)))
6282 		return 0;
6283 
6284 	trace_ext4_sync_fs(sb, wait);
6285 	flush_workqueue(sbi->rsv_conversion_wq);
6286 	/*
6287 	 * Writeback quota in non-journalled quota case - journalled quota has
6288 	 * no dirty dquots
6289 	 */
6290 	dquot_writeback_dquots(sb, -1);
6291 	/*
6292 	 * Data writeback is possible w/o journal transaction, so barrier must
6293 	 * being sent at the end of the function. But we can skip it if
6294 	 * transaction_commit will do it for us.
6295 	 */
6296 	if (sbi->s_journal) {
6297 		target = jbd2_get_latest_transaction(sbi->s_journal);
6298 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6299 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6300 			needs_barrier = true;
6301 
6302 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6303 			if (wait)
6304 				ret = jbd2_log_wait_commit(sbi->s_journal,
6305 							   target);
6306 		}
6307 	} else if (wait && test_opt(sb, BARRIER))
6308 		needs_barrier = true;
6309 	if (needs_barrier) {
6310 		int err;
6311 		err = blkdev_issue_flush(sb->s_bdev);
6312 		if (!ret)
6313 			ret = err;
6314 	}
6315 
6316 	return ret;
6317 }
6318 
6319 /*
6320  * LVM calls this function before a (read-only) snapshot is created.  This
6321  * gives us a chance to flush the journal completely and mark the fs clean.
6322  *
6323  * Note that only this function cannot bring a filesystem to be in a clean
6324  * state independently. It relies on upper layer to stop all data & metadata
6325  * modifications.
6326  */
6327 static int ext4_freeze(struct super_block *sb)
6328 {
6329 	int error = 0;
6330 	journal_t *journal = EXT4_SB(sb)->s_journal;
6331 
6332 	if (journal) {
6333 		/* Now we set up the journal barrier. */
6334 		jbd2_journal_lock_updates(journal);
6335 
6336 		/*
6337 		 * Don't clear the needs_recovery flag if we failed to
6338 		 * flush the journal.
6339 		 */
6340 		error = jbd2_journal_flush(journal, 0);
6341 		if (error < 0)
6342 			goto out;
6343 
6344 		/* Journal blocked and flushed, clear needs_recovery flag. */
6345 		ext4_clear_feature_journal_needs_recovery(sb);
6346 		if (ext4_orphan_file_empty(sb))
6347 			ext4_clear_feature_orphan_present(sb);
6348 	}
6349 
6350 	error = ext4_commit_super(sb);
6351 out:
6352 	if (journal)
6353 		/* we rely on upper layer to stop further updates */
6354 		jbd2_journal_unlock_updates(journal);
6355 	return error;
6356 }
6357 
6358 /*
6359  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6360  * flag here, even though the filesystem is not technically dirty yet.
6361  */
6362 static int ext4_unfreeze(struct super_block *sb)
6363 {
6364 	if (ext4_forced_shutdown(sb))
6365 		return 0;
6366 
6367 	if (EXT4_SB(sb)->s_journal) {
6368 		/* Reset the needs_recovery flag before the fs is unlocked. */
6369 		ext4_set_feature_journal_needs_recovery(sb);
6370 		if (ext4_has_feature_orphan_file(sb))
6371 			ext4_set_feature_orphan_present(sb);
6372 	}
6373 
6374 	ext4_commit_super(sb);
6375 	return 0;
6376 }
6377 
6378 /*
6379  * Structure to save mount options for ext4_remount's benefit
6380  */
6381 struct ext4_mount_options {
6382 	unsigned long s_mount_opt;
6383 	unsigned long s_mount_opt2;
6384 	kuid_t s_resuid;
6385 	kgid_t s_resgid;
6386 	unsigned long s_commit_interval;
6387 	u32 s_min_batch_time, s_max_batch_time;
6388 #ifdef CONFIG_QUOTA
6389 	int s_jquota_fmt;
6390 	char *s_qf_names[EXT4_MAXQUOTAS];
6391 #endif
6392 };
6393 
6394 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6395 {
6396 	struct ext4_fs_context *ctx = fc->fs_private;
6397 	struct ext4_super_block *es;
6398 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6399 	unsigned long old_sb_flags;
6400 	struct ext4_mount_options old_opts;
6401 	ext4_group_t g;
6402 	int err = 0;
6403 	int alloc_ctx;
6404 #ifdef CONFIG_QUOTA
6405 	int enable_quota = 0;
6406 	int i, j;
6407 	char *to_free[EXT4_MAXQUOTAS];
6408 #endif
6409 
6410 
6411 	/* Store the original options */
6412 	old_sb_flags = sb->s_flags;
6413 	old_opts.s_mount_opt = sbi->s_mount_opt;
6414 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6415 	old_opts.s_resuid = sbi->s_resuid;
6416 	old_opts.s_resgid = sbi->s_resgid;
6417 	old_opts.s_commit_interval = sbi->s_commit_interval;
6418 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6419 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6420 #ifdef CONFIG_QUOTA
6421 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6422 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6423 		if (sbi->s_qf_names[i]) {
6424 			char *qf_name = get_qf_name(sb, sbi, i);
6425 
6426 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6427 			if (!old_opts.s_qf_names[i]) {
6428 				for (j = 0; j < i; j++)
6429 					kfree(old_opts.s_qf_names[j]);
6430 				return -ENOMEM;
6431 			}
6432 		} else
6433 			old_opts.s_qf_names[i] = NULL;
6434 #endif
6435 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6436 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6437 			ctx->journal_ioprio =
6438 				sbi->s_journal->j_task->io_context->ioprio;
6439 		else
6440 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6441 
6442 	}
6443 
6444 	/*
6445 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6446 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6447 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6448 	 * here s_writepages_rwsem to avoid race between writepages ops and
6449 	 * remount.
6450 	 */
6451 	alloc_ctx = ext4_writepages_down_write(sb);
6452 	ext4_apply_options(fc, sb);
6453 	ext4_writepages_up_write(sb, alloc_ctx);
6454 
6455 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6456 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6457 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6458 			 "during remount not supported; ignoring");
6459 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6460 	}
6461 
6462 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6463 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6464 			ext4_msg(sb, KERN_ERR, "can't mount with "
6465 				 "both data=journal and delalloc");
6466 			err = -EINVAL;
6467 			goto restore_opts;
6468 		}
6469 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6470 			ext4_msg(sb, KERN_ERR, "can't mount with "
6471 				 "both data=journal and dioread_nolock");
6472 			err = -EINVAL;
6473 			goto restore_opts;
6474 		}
6475 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6476 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6477 			ext4_msg(sb, KERN_ERR, "can't mount with "
6478 				"journal_async_commit in data=ordered mode");
6479 			err = -EINVAL;
6480 			goto restore_opts;
6481 		}
6482 	}
6483 
6484 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6485 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6486 		err = -EINVAL;
6487 		goto restore_opts;
6488 	}
6489 
6490 	if (test_opt2(sb, ABORT))
6491 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6492 
6493 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6494 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6495 
6496 	es = sbi->s_es;
6497 
6498 	if (sbi->s_journal) {
6499 		ext4_init_journal_params(sb, sbi->s_journal);
6500 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6501 	}
6502 
6503 	/* Flush outstanding errors before changing fs state */
6504 	flush_work(&sbi->s_sb_upd_work);
6505 
6506 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6507 		if (ext4_forced_shutdown(sb)) {
6508 			err = -EROFS;
6509 			goto restore_opts;
6510 		}
6511 
6512 		if (fc->sb_flags & SB_RDONLY) {
6513 			err = sync_filesystem(sb);
6514 			if (err < 0)
6515 				goto restore_opts;
6516 			err = dquot_suspend(sb, -1);
6517 			if (err < 0)
6518 				goto restore_opts;
6519 
6520 			/*
6521 			 * First of all, the unconditional stuff we have to do
6522 			 * to disable replay of the journal when we next remount
6523 			 */
6524 			sb->s_flags |= SB_RDONLY;
6525 
6526 			/*
6527 			 * OK, test if we are remounting a valid rw partition
6528 			 * readonly, and if so set the rdonly flag and then
6529 			 * mark the partition as valid again.
6530 			 */
6531 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6532 			    (sbi->s_mount_state & EXT4_VALID_FS))
6533 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6534 
6535 			if (sbi->s_journal) {
6536 				/*
6537 				 * We let remount-ro finish even if marking fs
6538 				 * as clean failed...
6539 				 */
6540 				ext4_mark_recovery_complete(sb, es);
6541 			}
6542 		} else {
6543 			/* Make sure we can mount this feature set readwrite */
6544 			if (ext4_has_feature_readonly(sb) ||
6545 			    !ext4_feature_set_ok(sb, 0)) {
6546 				err = -EROFS;
6547 				goto restore_opts;
6548 			}
6549 			/*
6550 			 * Make sure the group descriptor checksums
6551 			 * are sane.  If they aren't, refuse to remount r/w.
6552 			 */
6553 			for (g = 0; g < sbi->s_groups_count; g++) {
6554 				struct ext4_group_desc *gdp =
6555 					ext4_get_group_desc(sb, g, NULL);
6556 
6557 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6558 					ext4_msg(sb, KERN_ERR,
6559 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6560 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6561 					       le16_to_cpu(gdp->bg_checksum));
6562 					err = -EFSBADCRC;
6563 					goto restore_opts;
6564 				}
6565 			}
6566 
6567 			/*
6568 			 * If we have an unprocessed orphan list hanging
6569 			 * around from a previously readonly bdev mount,
6570 			 * require a full umount/remount for now.
6571 			 */
6572 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6573 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6574 				       "remount RDWR because of unprocessed "
6575 				       "orphan inode list.  Please "
6576 				       "umount/remount instead");
6577 				err = -EINVAL;
6578 				goto restore_opts;
6579 			}
6580 
6581 			/*
6582 			 * Mounting a RDONLY partition read-write, so reread
6583 			 * and store the current valid flag.  (It may have
6584 			 * been changed by e2fsck since we originally mounted
6585 			 * the partition.)
6586 			 */
6587 			if (sbi->s_journal) {
6588 				err = ext4_clear_journal_err(sb, es);
6589 				if (err)
6590 					goto restore_opts;
6591 			}
6592 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6593 					      ~EXT4_FC_REPLAY);
6594 
6595 			err = ext4_setup_super(sb, es, 0);
6596 			if (err)
6597 				goto restore_opts;
6598 
6599 			sb->s_flags &= ~SB_RDONLY;
6600 			if (ext4_has_feature_mmp(sb)) {
6601 				err = ext4_multi_mount_protect(sb,
6602 						le64_to_cpu(es->s_mmp_block));
6603 				if (err)
6604 					goto restore_opts;
6605 			}
6606 #ifdef CONFIG_QUOTA
6607 			enable_quota = 1;
6608 #endif
6609 		}
6610 	}
6611 
6612 	/*
6613 	 * Handle creation of system zone data early because it can fail.
6614 	 * Releasing of existing data is done when we are sure remount will
6615 	 * succeed.
6616 	 */
6617 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6618 		err = ext4_setup_system_zone(sb);
6619 		if (err)
6620 			goto restore_opts;
6621 	}
6622 
6623 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6624 		err = ext4_commit_super(sb);
6625 		if (err)
6626 			goto restore_opts;
6627 	}
6628 
6629 #ifdef CONFIG_QUOTA
6630 	if (enable_quota) {
6631 		if (sb_any_quota_suspended(sb))
6632 			dquot_resume(sb, -1);
6633 		else if (ext4_has_feature_quota(sb)) {
6634 			err = ext4_enable_quotas(sb);
6635 			if (err)
6636 				goto restore_opts;
6637 		}
6638 	}
6639 	/* Release old quota file names */
6640 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6641 		kfree(old_opts.s_qf_names[i]);
6642 #endif
6643 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6644 		ext4_release_system_zone(sb);
6645 
6646 	/*
6647 	 * Reinitialize lazy itable initialization thread based on
6648 	 * current settings
6649 	 */
6650 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6651 		ext4_unregister_li_request(sb);
6652 	else {
6653 		ext4_group_t first_not_zeroed;
6654 		first_not_zeroed = ext4_has_uninit_itable(sb);
6655 		ext4_register_li_request(sb, first_not_zeroed);
6656 	}
6657 
6658 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6659 		ext4_stop_mmpd(sbi);
6660 
6661 	return 0;
6662 
6663 restore_opts:
6664 	/*
6665 	 * If there was a failing r/w to ro transition, we may need to
6666 	 * re-enable quota
6667 	 */
6668 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6669 	    sb_any_quota_suspended(sb))
6670 		dquot_resume(sb, -1);
6671 
6672 	alloc_ctx = ext4_writepages_down_write(sb);
6673 	sb->s_flags = old_sb_flags;
6674 	sbi->s_mount_opt = old_opts.s_mount_opt;
6675 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6676 	sbi->s_resuid = old_opts.s_resuid;
6677 	sbi->s_resgid = old_opts.s_resgid;
6678 	sbi->s_commit_interval = old_opts.s_commit_interval;
6679 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6680 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6681 	ext4_writepages_up_write(sb, alloc_ctx);
6682 
6683 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6684 		ext4_release_system_zone(sb);
6685 #ifdef CONFIG_QUOTA
6686 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6687 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6688 		to_free[i] = get_qf_name(sb, sbi, i);
6689 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6690 	}
6691 	synchronize_rcu();
6692 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6693 		kfree(to_free[i]);
6694 #endif
6695 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6696 		ext4_stop_mmpd(sbi);
6697 	return err;
6698 }
6699 
6700 static int ext4_reconfigure(struct fs_context *fc)
6701 {
6702 	struct super_block *sb = fc->root->d_sb;
6703 	int ret;
6704 
6705 	fc->s_fs_info = EXT4_SB(sb);
6706 
6707 	ret = ext4_check_opt_consistency(fc, sb);
6708 	if (ret < 0)
6709 		return ret;
6710 
6711 	ret = __ext4_remount(fc, sb);
6712 	if (ret < 0)
6713 		return ret;
6714 
6715 	ext4_msg(sb, KERN_INFO, "re-mounted %pU %s. Quota mode: %s.",
6716 		 &sb->s_uuid, sb_rdonly(sb) ? "ro" : "r/w",
6717 		 ext4_quota_mode(sb));
6718 
6719 	return 0;
6720 }
6721 
6722 #ifdef CONFIG_QUOTA
6723 static int ext4_statfs_project(struct super_block *sb,
6724 			       kprojid_t projid, struct kstatfs *buf)
6725 {
6726 	struct kqid qid;
6727 	struct dquot *dquot;
6728 	u64 limit;
6729 	u64 curblock;
6730 
6731 	qid = make_kqid_projid(projid);
6732 	dquot = dqget(sb, qid);
6733 	if (IS_ERR(dquot))
6734 		return PTR_ERR(dquot);
6735 	spin_lock(&dquot->dq_dqb_lock);
6736 
6737 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6738 			     dquot->dq_dqb.dqb_bhardlimit);
6739 	limit >>= sb->s_blocksize_bits;
6740 
6741 	if (limit && buf->f_blocks > limit) {
6742 		curblock = (dquot->dq_dqb.dqb_curspace +
6743 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6744 		buf->f_blocks = limit;
6745 		buf->f_bfree = buf->f_bavail =
6746 			(buf->f_blocks > curblock) ?
6747 			 (buf->f_blocks - curblock) : 0;
6748 	}
6749 
6750 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6751 			     dquot->dq_dqb.dqb_ihardlimit);
6752 	if (limit && buf->f_files > limit) {
6753 		buf->f_files = limit;
6754 		buf->f_ffree =
6755 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6756 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6757 	}
6758 
6759 	spin_unlock(&dquot->dq_dqb_lock);
6760 	dqput(dquot);
6761 	return 0;
6762 }
6763 #endif
6764 
6765 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6766 {
6767 	struct super_block *sb = dentry->d_sb;
6768 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6769 	struct ext4_super_block *es = sbi->s_es;
6770 	ext4_fsblk_t overhead = 0, resv_blocks;
6771 	s64 bfree;
6772 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6773 
6774 	if (!test_opt(sb, MINIX_DF))
6775 		overhead = sbi->s_overhead;
6776 
6777 	buf->f_type = EXT4_SUPER_MAGIC;
6778 	buf->f_bsize = sb->s_blocksize;
6779 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6780 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6781 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6782 	/* prevent underflow in case that few free space is available */
6783 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6784 	buf->f_bavail = buf->f_bfree -
6785 			(ext4_r_blocks_count(es) + resv_blocks);
6786 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6787 		buf->f_bavail = 0;
6788 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6789 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6790 	buf->f_namelen = EXT4_NAME_LEN;
6791 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6792 
6793 #ifdef CONFIG_QUOTA
6794 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6795 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6796 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6797 #endif
6798 	return 0;
6799 }
6800 
6801 
6802 #ifdef CONFIG_QUOTA
6803 
6804 /*
6805  * Helper functions so that transaction is started before we acquire dqio_sem
6806  * to keep correct lock ordering of transaction > dqio_sem
6807  */
6808 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6809 {
6810 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6811 }
6812 
6813 static int ext4_write_dquot(struct dquot *dquot)
6814 {
6815 	int ret, err;
6816 	handle_t *handle;
6817 	struct inode *inode;
6818 
6819 	inode = dquot_to_inode(dquot);
6820 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6821 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6822 	if (IS_ERR(handle))
6823 		return PTR_ERR(handle);
6824 	ret = dquot_commit(dquot);
6825 	if (ret < 0)
6826 		ext4_error_err(dquot->dq_sb, -ret,
6827 			       "Failed to commit dquot type %d",
6828 			       dquot->dq_id.type);
6829 	err = ext4_journal_stop(handle);
6830 	if (!ret)
6831 		ret = err;
6832 	return ret;
6833 }
6834 
6835 static int ext4_acquire_dquot(struct dquot *dquot)
6836 {
6837 	int ret, err;
6838 	handle_t *handle;
6839 
6840 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6841 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6842 	if (IS_ERR(handle))
6843 		return PTR_ERR(handle);
6844 	ret = dquot_acquire(dquot);
6845 	if (ret < 0)
6846 		ext4_error_err(dquot->dq_sb, -ret,
6847 			      "Failed to acquire dquot type %d",
6848 			      dquot->dq_id.type);
6849 	err = ext4_journal_stop(handle);
6850 	if (!ret)
6851 		ret = err;
6852 	return ret;
6853 }
6854 
6855 static int ext4_release_dquot(struct dquot *dquot)
6856 {
6857 	int ret, err;
6858 	handle_t *handle;
6859 
6860 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6861 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6862 	if (IS_ERR(handle)) {
6863 		/* Release dquot anyway to avoid endless cycle in dqput() */
6864 		dquot_release(dquot);
6865 		return PTR_ERR(handle);
6866 	}
6867 	ret = dquot_release(dquot);
6868 	if (ret < 0)
6869 		ext4_error_err(dquot->dq_sb, -ret,
6870 			       "Failed to release dquot type %d",
6871 			       dquot->dq_id.type);
6872 	err = ext4_journal_stop(handle);
6873 	if (!ret)
6874 		ret = err;
6875 	return ret;
6876 }
6877 
6878 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6879 {
6880 	struct super_block *sb = dquot->dq_sb;
6881 
6882 	if (ext4_is_quota_journalled(sb)) {
6883 		dquot_mark_dquot_dirty(dquot);
6884 		return ext4_write_dquot(dquot);
6885 	} else {
6886 		return dquot_mark_dquot_dirty(dquot);
6887 	}
6888 }
6889 
6890 static int ext4_write_info(struct super_block *sb, int type)
6891 {
6892 	int ret, err;
6893 	handle_t *handle;
6894 
6895 	/* Data block + inode block */
6896 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6897 	if (IS_ERR(handle))
6898 		return PTR_ERR(handle);
6899 	ret = dquot_commit_info(sb, type);
6900 	err = ext4_journal_stop(handle);
6901 	if (!ret)
6902 		ret = err;
6903 	return ret;
6904 }
6905 
6906 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6907 {
6908 	struct ext4_inode_info *ei = EXT4_I(inode);
6909 
6910 	/* The first argument of lockdep_set_subclass has to be
6911 	 * *exactly* the same as the argument to init_rwsem() --- in
6912 	 * this case, in init_once() --- or lockdep gets unhappy
6913 	 * because the name of the lock is set using the
6914 	 * stringification of the argument to init_rwsem().
6915 	 */
6916 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6917 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6918 }
6919 
6920 /*
6921  * Standard function to be called on quota_on
6922  */
6923 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6924 			 const struct path *path)
6925 {
6926 	int err;
6927 
6928 	if (!test_opt(sb, QUOTA))
6929 		return -EINVAL;
6930 
6931 	/* Quotafile not on the same filesystem? */
6932 	if (path->dentry->d_sb != sb)
6933 		return -EXDEV;
6934 
6935 	/* Quota already enabled for this file? */
6936 	if (IS_NOQUOTA(d_inode(path->dentry)))
6937 		return -EBUSY;
6938 
6939 	/* Journaling quota? */
6940 	if (EXT4_SB(sb)->s_qf_names[type]) {
6941 		/* Quotafile not in fs root? */
6942 		if (path->dentry->d_parent != sb->s_root)
6943 			ext4_msg(sb, KERN_WARNING,
6944 				"Quota file not on filesystem root. "
6945 				"Journaled quota will not work");
6946 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6947 	} else {
6948 		/*
6949 		 * Clear the flag just in case mount options changed since
6950 		 * last time.
6951 		 */
6952 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6953 	}
6954 
6955 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6956 	err = dquot_quota_on(sb, type, format_id, path);
6957 	if (!err) {
6958 		struct inode *inode = d_inode(path->dentry);
6959 		handle_t *handle;
6960 
6961 		/*
6962 		 * Set inode flags to prevent userspace from messing with quota
6963 		 * files. If this fails, we return success anyway since quotas
6964 		 * are already enabled and this is not a hard failure.
6965 		 */
6966 		inode_lock(inode);
6967 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6968 		if (IS_ERR(handle))
6969 			goto unlock_inode;
6970 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6971 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6972 				S_NOATIME | S_IMMUTABLE);
6973 		err = ext4_mark_inode_dirty(handle, inode);
6974 		ext4_journal_stop(handle);
6975 	unlock_inode:
6976 		inode_unlock(inode);
6977 		if (err)
6978 			dquot_quota_off(sb, type);
6979 	}
6980 	if (err)
6981 		lockdep_set_quota_inode(path->dentry->d_inode,
6982 					     I_DATA_SEM_NORMAL);
6983 	return err;
6984 }
6985 
6986 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
6987 {
6988 	switch (type) {
6989 	case USRQUOTA:
6990 		return qf_inum == EXT4_USR_QUOTA_INO;
6991 	case GRPQUOTA:
6992 		return qf_inum == EXT4_GRP_QUOTA_INO;
6993 	case PRJQUOTA:
6994 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
6995 	default:
6996 		BUG();
6997 	}
6998 }
6999 
7000 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7001 			     unsigned int flags)
7002 {
7003 	int err;
7004 	struct inode *qf_inode;
7005 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7006 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7007 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7008 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7009 	};
7010 
7011 	BUG_ON(!ext4_has_feature_quota(sb));
7012 
7013 	if (!qf_inums[type])
7014 		return -EPERM;
7015 
7016 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7017 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7018 				qf_inums[type], type);
7019 		return -EUCLEAN;
7020 	}
7021 
7022 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7023 	if (IS_ERR(qf_inode)) {
7024 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7025 				qf_inums[type], type);
7026 		return PTR_ERR(qf_inode);
7027 	}
7028 
7029 	/* Don't account quota for quota files to avoid recursion */
7030 	qf_inode->i_flags |= S_NOQUOTA;
7031 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7032 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7033 	if (err)
7034 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7035 	iput(qf_inode);
7036 
7037 	return err;
7038 }
7039 
7040 /* Enable usage tracking for all quota types. */
7041 int ext4_enable_quotas(struct super_block *sb)
7042 {
7043 	int type, err = 0;
7044 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7045 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7046 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7047 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7048 	};
7049 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7050 		test_opt(sb, USRQUOTA),
7051 		test_opt(sb, GRPQUOTA),
7052 		test_opt(sb, PRJQUOTA),
7053 	};
7054 
7055 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7056 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7057 		if (qf_inums[type]) {
7058 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7059 				DQUOT_USAGE_ENABLED |
7060 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7061 			if (err) {
7062 				ext4_warning(sb,
7063 					"Failed to enable quota tracking "
7064 					"(type=%d, err=%d, ino=%lu). "
7065 					"Please run e2fsck to fix.", type,
7066 					err, qf_inums[type]);
7067 
7068 				ext4_quotas_off(sb, type);
7069 				return err;
7070 			}
7071 		}
7072 	}
7073 	return 0;
7074 }
7075 
7076 static int ext4_quota_off(struct super_block *sb, int type)
7077 {
7078 	struct inode *inode = sb_dqopt(sb)->files[type];
7079 	handle_t *handle;
7080 	int err;
7081 
7082 	/* Force all delayed allocation blocks to be allocated.
7083 	 * Caller already holds s_umount sem */
7084 	if (test_opt(sb, DELALLOC))
7085 		sync_filesystem(sb);
7086 
7087 	if (!inode || !igrab(inode))
7088 		goto out;
7089 
7090 	err = dquot_quota_off(sb, type);
7091 	if (err || ext4_has_feature_quota(sb))
7092 		goto out_put;
7093 	/*
7094 	 * When the filesystem was remounted read-only first, we cannot cleanup
7095 	 * inode flags here. Bad luck but people should be using QUOTA feature
7096 	 * these days anyway.
7097 	 */
7098 	if (sb_rdonly(sb))
7099 		goto out_put;
7100 
7101 	inode_lock(inode);
7102 	/*
7103 	 * Update modification times of quota files when userspace can
7104 	 * start looking at them. If we fail, we return success anyway since
7105 	 * this is not a hard failure and quotas are already disabled.
7106 	 */
7107 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7108 	if (IS_ERR(handle)) {
7109 		err = PTR_ERR(handle);
7110 		goto out_unlock;
7111 	}
7112 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7113 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7114 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
7115 	err = ext4_mark_inode_dirty(handle, inode);
7116 	ext4_journal_stop(handle);
7117 out_unlock:
7118 	inode_unlock(inode);
7119 out_put:
7120 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7121 	iput(inode);
7122 	return err;
7123 out:
7124 	return dquot_quota_off(sb, type);
7125 }
7126 
7127 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7128  * acquiring the locks... As quota files are never truncated and quota code
7129  * itself serializes the operations (and no one else should touch the files)
7130  * we don't have to be afraid of races */
7131 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7132 			       size_t len, loff_t off)
7133 {
7134 	struct inode *inode = sb_dqopt(sb)->files[type];
7135 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7136 	int offset = off & (sb->s_blocksize - 1);
7137 	int tocopy;
7138 	size_t toread;
7139 	struct buffer_head *bh;
7140 	loff_t i_size = i_size_read(inode);
7141 
7142 	if (off > i_size)
7143 		return 0;
7144 	if (off+len > i_size)
7145 		len = i_size-off;
7146 	toread = len;
7147 	while (toread > 0) {
7148 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7149 		bh = ext4_bread(NULL, inode, blk, 0);
7150 		if (IS_ERR(bh))
7151 			return PTR_ERR(bh);
7152 		if (!bh)	/* A hole? */
7153 			memset(data, 0, tocopy);
7154 		else
7155 			memcpy(data, bh->b_data+offset, tocopy);
7156 		brelse(bh);
7157 		offset = 0;
7158 		toread -= tocopy;
7159 		data += tocopy;
7160 		blk++;
7161 	}
7162 	return len;
7163 }
7164 
7165 /* Write to quotafile (we know the transaction is already started and has
7166  * enough credits) */
7167 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7168 				const char *data, size_t len, loff_t off)
7169 {
7170 	struct inode *inode = sb_dqopt(sb)->files[type];
7171 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7172 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7173 	int retries = 0;
7174 	struct buffer_head *bh;
7175 	handle_t *handle = journal_current_handle();
7176 
7177 	if (!handle) {
7178 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7179 			" cancelled because transaction is not started",
7180 			(unsigned long long)off, (unsigned long long)len);
7181 		return -EIO;
7182 	}
7183 	/*
7184 	 * Since we account only one data block in transaction credits,
7185 	 * then it is impossible to cross a block boundary.
7186 	 */
7187 	if (sb->s_blocksize - offset < len) {
7188 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7189 			" cancelled because not block aligned",
7190 			(unsigned long long)off, (unsigned long long)len);
7191 		return -EIO;
7192 	}
7193 
7194 	do {
7195 		bh = ext4_bread(handle, inode, blk,
7196 				EXT4_GET_BLOCKS_CREATE |
7197 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7198 	} while (PTR_ERR(bh) == -ENOSPC &&
7199 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7200 	if (IS_ERR(bh))
7201 		return PTR_ERR(bh);
7202 	if (!bh)
7203 		goto out;
7204 	BUFFER_TRACE(bh, "get write access");
7205 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7206 	if (err) {
7207 		brelse(bh);
7208 		return err;
7209 	}
7210 	lock_buffer(bh);
7211 	memcpy(bh->b_data+offset, data, len);
7212 	flush_dcache_page(bh->b_page);
7213 	unlock_buffer(bh);
7214 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7215 	brelse(bh);
7216 out:
7217 	if (inode->i_size < off + len) {
7218 		i_size_write(inode, off + len);
7219 		EXT4_I(inode)->i_disksize = inode->i_size;
7220 		err2 = ext4_mark_inode_dirty(handle, inode);
7221 		if (unlikely(err2 && !err))
7222 			err = err2;
7223 	}
7224 	return err ? err : len;
7225 }
7226 #endif
7227 
7228 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7229 static inline void register_as_ext2(void)
7230 {
7231 	int err = register_filesystem(&ext2_fs_type);
7232 	if (err)
7233 		printk(KERN_WARNING
7234 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7235 }
7236 
7237 static inline void unregister_as_ext2(void)
7238 {
7239 	unregister_filesystem(&ext2_fs_type);
7240 }
7241 
7242 static inline int ext2_feature_set_ok(struct super_block *sb)
7243 {
7244 	if (ext4_has_unknown_ext2_incompat_features(sb))
7245 		return 0;
7246 	if (sb_rdonly(sb))
7247 		return 1;
7248 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7249 		return 0;
7250 	return 1;
7251 }
7252 #else
7253 static inline void register_as_ext2(void) { }
7254 static inline void unregister_as_ext2(void) { }
7255 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7256 #endif
7257 
7258 static inline void register_as_ext3(void)
7259 {
7260 	int err = register_filesystem(&ext3_fs_type);
7261 	if (err)
7262 		printk(KERN_WARNING
7263 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7264 }
7265 
7266 static inline void unregister_as_ext3(void)
7267 {
7268 	unregister_filesystem(&ext3_fs_type);
7269 }
7270 
7271 static inline int ext3_feature_set_ok(struct super_block *sb)
7272 {
7273 	if (ext4_has_unknown_ext3_incompat_features(sb))
7274 		return 0;
7275 	if (!ext4_has_feature_journal(sb))
7276 		return 0;
7277 	if (sb_rdonly(sb))
7278 		return 1;
7279 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7280 		return 0;
7281 	return 1;
7282 }
7283 
7284 static void ext4_kill_sb(struct super_block *sb)
7285 {
7286 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7287 	struct file *bdev_file = sbi ? sbi->s_journal_bdev_file : NULL;
7288 
7289 	kill_block_super(sb);
7290 
7291 	if (bdev_file)
7292 		bdev_fput(bdev_file);
7293 }
7294 
7295 static struct file_system_type ext4_fs_type = {
7296 	.owner			= THIS_MODULE,
7297 	.name			= "ext4",
7298 	.init_fs_context	= ext4_init_fs_context,
7299 	.parameters		= ext4_param_specs,
7300 	.kill_sb		= ext4_kill_sb,
7301 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7302 };
7303 MODULE_ALIAS_FS("ext4");
7304 
7305 /* Shared across all ext4 file systems */
7306 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7307 
7308 static int __init ext4_init_fs(void)
7309 {
7310 	int i, err;
7311 
7312 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7313 	ext4_li_info = NULL;
7314 
7315 	/* Build-time check for flags consistency */
7316 	ext4_check_flag_values();
7317 
7318 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7319 		init_waitqueue_head(&ext4__ioend_wq[i]);
7320 
7321 	err = ext4_init_es();
7322 	if (err)
7323 		return err;
7324 
7325 	err = ext4_init_pending();
7326 	if (err)
7327 		goto out7;
7328 
7329 	err = ext4_init_post_read_processing();
7330 	if (err)
7331 		goto out6;
7332 
7333 	err = ext4_init_pageio();
7334 	if (err)
7335 		goto out5;
7336 
7337 	err = ext4_init_system_zone();
7338 	if (err)
7339 		goto out4;
7340 
7341 	err = ext4_init_sysfs();
7342 	if (err)
7343 		goto out3;
7344 
7345 	err = ext4_init_mballoc();
7346 	if (err)
7347 		goto out2;
7348 	err = init_inodecache();
7349 	if (err)
7350 		goto out1;
7351 
7352 	err = ext4_fc_init_dentry_cache();
7353 	if (err)
7354 		goto out05;
7355 
7356 	register_as_ext3();
7357 	register_as_ext2();
7358 	err = register_filesystem(&ext4_fs_type);
7359 	if (err)
7360 		goto out;
7361 
7362 	return 0;
7363 out:
7364 	unregister_as_ext2();
7365 	unregister_as_ext3();
7366 	ext4_fc_destroy_dentry_cache();
7367 out05:
7368 	destroy_inodecache();
7369 out1:
7370 	ext4_exit_mballoc();
7371 out2:
7372 	ext4_exit_sysfs();
7373 out3:
7374 	ext4_exit_system_zone();
7375 out4:
7376 	ext4_exit_pageio();
7377 out5:
7378 	ext4_exit_post_read_processing();
7379 out6:
7380 	ext4_exit_pending();
7381 out7:
7382 	ext4_exit_es();
7383 
7384 	return err;
7385 }
7386 
7387 static void __exit ext4_exit_fs(void)
7388 {
7389 	ext4_destroy_lazyinit_thread();
7390 	unregister_as_ext2();
7391 	unregister_as_ext3();
7392 	unregister_filesystem(&ext4_fs_type);
7393 	ext4_fc_destroy_dentry_cache();
7394 	destroy_inodecache();
7395 	ext4_exit_mballoc();
7396 	ext4_exit_sysfs();
7397 	ext4_exit_system_zone();
7398 	ext4_exit_pageio();
7399 	ext4_exit_post_read_processing();
7400 	ext4_exit_es();
7401 	ext4_exit_pending();
7402 }
7403 
7404 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7405 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7406 MODULE_LICENSE("GPL");
7407 MODULE_SOFTDEP("pre: crc32c");
7408 module_init(ext4_init_fs)
7409 module_exit(ext4_exit_fs)
7410