xref: /openbmc/linux/fs/ext4/super.c (revision c494a447)
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 int 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 const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= kill_block_super,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= kill_block_super,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ, op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
207 {
208 	if (trylock_buffer(bh)) {
209 		if (wait)
210 			return ext4_read_bh(bh, op_flags, NULL);
211 		ext4_read_bh_nowait(bh, op_flags, NULL);
212 		return 0;
213 	}
214 	if (wait) {
215 		wait_on_buffer(bh);
216 		if (buffer_uptodate(bh))
217 			return 0;
218 		return -EIO;
219 	}
220 	return 0;
221 }
222 
223 /*
224  * This works like __bread_gfp() except it uses ERR_PTR for error
225  * returns.  Currently with sb_bread it's impossible to distinguish
226  * between ENOMEM and EIO situations (since both result in a NULL
227  * return.
228  */
229 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
230 					       sector_t block, int op_flags,
231 					       gfp_t gfp)
232 {
233 	struct buffer_head *bh;
234 	int ret;
235 
236 	bh = sb_getblk_gfp(sb, block, gfp);
237 	if (bh == NULL)
238 		return ERR_PTR(-ENOMEM);
239 	if (ext4_buffer_uptodate(bh))
240 		return bh;
241 
242 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
243 	if (ret) {
244 		put_bh(bh);
245 		return ERR_PTR(ret);
246 	}
247 	return bh;
248 }
249 
250 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
251 				   int op_flags)
252 {
253 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
254 }
255 
256 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
257 					    sector_t block)
258 {
259 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
260 }
261 
262 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
263 {
264 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
265 
266 	if (likely(bh)) {
267 		ext4_read_bh_lock(bh, REQ_RAHEAD, false);
268 		brelse(bh);
269 	}
270 }
271 
272 static int ext4_verify_csum_type(struct super_block *sb,
273 				 struct ext4_super_block *es)
274 {
275 	if (!ext4_has_feature_metadata_csum(sb))
276 		return 1;
277 
278 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
279 }
280 
281 __le32 ext4_superblock_csum(struct super_block *sb,
282 			    struct ext4_super_block *es)
283 {
284 	struct ext4_sb_info *sbi = EXT4_SB(sb);
285 	int offset = offsetof(struct ext4_super_block, s_checksum);
286 	__u32 csum;
287 
288 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
289 
290 	return cpu_to_le32(csum);
291 }
292 
293 static int ext4_superblock_csum_verify(struct super_block *sb,
294 				       struct ext4_super_block *es)
295 {
296 	if (!ext4_has_metadata_csum(sb))
297 		return 1;
298 
299 	return es->s_checksum == ext4_superblock_csum(sb, es);
300 }
301 
302 void ext4_superblock_csum_set(struct super_block *sb)
303 {
304 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
305 
306 	if (!ext4_has_metadata_csum(sb))
307 		return;
308 
309 	es->s_checksum = ext4_superblock_csum(sb, es);
310 }
311 
312 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
313 			       struct ext4_group_desc *bg)
314 {
315 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
316 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
317 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
318 }
319 
320 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
321 			       struct ext4_group_desc *bg)
322 {
323 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
324 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
325 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
326 }
327 
328 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
329 			      struct ext4_group_desc *bg)
330 {
331 	return le32_to_cpu(bg->bg_inode_table_lo) |
332 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
333 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
334 }
335 
336 __u32 ext4_free_group_clusters(struct super_block *sb,
337 			       struct ext4_group_desc *bg)
338 {
339 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
340 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
341 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
342 }
343 
344 __u32 ext4_free_inodes_count(struct super_block *sb,
345 			      struct ext4_group_desc *bg)
346 {
347 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
348 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
349 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
350 }
351 
352 __u32 ext4_used_dirs_count(struct super_block *sb,
353 			      struct ext4_group_desc *bg)
354 {
355 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
356 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
357 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
358 }
359 
360 __u32 ext4_itable_unused_count(struct super_block *sb,
361 			      struct ext4_group_desc *bg)
362 {
363 	return le16_to_cpu(bg->bg_itable_unused_lo) |
364 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
365 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
366 }
367 
368 void ext4_block_bitmap_set(struct super_block *sb,
369 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
370 {
371 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
372 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
373 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
374 }
375 
376 void ext4_inode_bitmap_set(struct super_block *sb,
377 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
378 {
379 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
380 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
381 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
382 }
383 
384 void ext4_inode_table_set(struct super_block *sb,
385 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
386 {
387 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
388 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
389 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
390 }
391 
392 void ext4_free_group_clusters_set(struct super_block *sb,
393 				  struct ext4_group_desc *bg, __u32 count)
394 {
395 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
396 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
397 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
398 }
399 
400 void ext4_free_inodes_set(struct super_block *sb,
401 			  struct ext4_group_desc *bg, __u32 count)
402 {
403 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
404 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
405 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
406 }
407 
408 void ext4_used_dirs_set(struct super_block *sb,
409 			  struct ext4_group_desc *bg, __u32 count)
410 {
411 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
412 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
413 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
414 }
415 
416 void ext4_itable_unused_set(struct super_block *sb,
417 			  struct ext4_group_desc *bg, __u32 count)
418 {
419 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
420 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
421 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
422 }
423 
424 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
425 {
426 	now = clamp_val(now, 0, (1ull << 40) - 1);
427 
428 	*lo = cpu_to_le32(lower_32_bits(now));
429 	*hi = upper_32_bits(now);
430 }
431 
432 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
433 {
434 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
435 }
436 #define ext4_update_tstamp(es, tstamp) \
437 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
438 			     ktime_get_real_seconds())
439 #define ext4_get_tstamp(es, tstamp) \
440 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
441 
442 /*
443  * The del_gendisk() function uninitializes the disk-specific data
444  * structures, including the bdi structure, without telling anyone
445  * else.  Once this happens, any attempt to call mark_buffer_dirty()
446  * (for example, by ext4_commit_super), will cause a kernel OOPS.
447  * This is a kludge to prevent these oops until we can put in a proper
448  * hook in del_gendisk() to inform the VFS and file system layers.
449  */
450 static int block_device_ejected(struct super_block *sb)
451 {
452 	struct inode *bd_inode = sb->s_bdev->bd_inode;
453 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
454 
455 	return bdi->dev == NULL;
456 }
457 
458 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
459 {
460 	struct super_block		*sb = journal->j_private;
461 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
462 	int				error = is_journal_aborted(journal);
463 	struct ext4_journal_cb_entry	*jce;
464 
465 	BUG_ON(txn->t_state == T_FINISHED);
466 
467 	ext4_process_freed_data(sb, txn->t_tid);
468 
469 	spin_lock(&sbi->s_md_lock);
470 	while (!list_empty(&txn->t_private_list)) {
471 		jce = list_entry(txn->t_private_list.next,
472 				 struct ext4_journal_cb_entry, jce_list);
473 		list_del_init(&jce->jce_list);
474 		spin_unlock(&sbi->s_md_lock);
475 		jce->jce_func(sb, jce, error);
476 		spin_lock(&sbi->s_md_lock);
477 	}
478 	spin_unlock(&sbi->s_md_lock);
479 }
480 
481 /*
482  * This writepage callback for write_cache_pages()
483  * takes care of a few cases after page cleaning.
484  *
485  * write_cache_pages() already checks for dirty pages
486  * and calls clear_page_dirty_for_io(), which we want,
487  * to write protect the pages.
488  *
489  * However, we may have to redirty a page (see below.)
490  */
491 static int ext4_journalled_writepage_callback(struct page *page,
492 					      struct writeback_control *wbc,
493 					      void *data)
494 {
495 	transaction_t *transaction = (transaction_t *) data;
496 	struct buffer_head *bh, *head;
497 	struct journal_head *jh;
498 
499 	bh = head = page_buffers(page);
500 	do {
501 		/*
502 		 * We have to redirty a page in these cases:
503 		 * 1) If buffer is dirty, it means the page was dirty because it
504 		 * contains a buffer that needs checkpointing. So the dirty bit
505 		 * needs to be preserved so that checkpointing writes the buffer
506 		 * properly.
507 		 * 2) If buffer is not part of the committing transaction
508 		 * (we may have just accidentally come across this buffer because
509 		 * inode range tracking is not exact) or if the currently running
510 		 * transaction already contains this buffer as well, dirty bit
511 		 * needs to be preserved so that the buffer gets writeprotected
512 		 * properly on running transaction's commit.
513 		 */
514 		jh = bh2jh(bh);
515 		if (buffer_dirty(bh) ||
516 		    (jh && (jh->b_transaction != transaction ||
517 			    jh->b_next_transaction))) {
518 			redirty_page_for_writepage(wbc, page);
519 			goto out;
520 		}
521 	} while ((bh = bh->b_this_page) != head);
522 
523 out:
524 	return AOP_WRITEPAGE_ACTIVATE;
525 }
526 
527 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
528 {
529 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
530 	struct writeback_control wbc = {
531 		.sync_mode =  WB_SYNC_ALL,
532 		.nr_to_write = LONG_MAX,
533 		.range_start = jinode->i_dirty_start,
534 		.range_end = jinode->i_dirty_end,
535         };
536 
537 	return write_cache_pages(mapping, &wbc,
538 				 ext4_journalled_writepage_callback,
539 				 jinode->i_transaction);
540 }
541 
542 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
543 {
544 	int ret;
545 
546 	if (ext4_should_journal_data(jinode->i_vfs_inode))
547 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
548 	else
549 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
550 
551 	return ret;
552 }
553 
554 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
555 {
556 	int ret = 0;
557 
558 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
559 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
560 
561 	return ret;
562 }
563 
564 static bool system_going_down(void)
565 {
566 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
567 		|| system_state == SYSTEM_RESTART;
568 }
569 
570 struct ext4_err_translation {
571 	int code;
572 	int errno;
573 };
574 
575 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
576 
577 static struct ext4_err_translation err_translation[] = {
578 	EXT4_ERR_TRANSLATE(EIO),
579 	EXT4_ERR_TRANSLATE(ENOMEM),
580 	EXT4_ERR_TRANSLATE(EFSBADCRC),
581 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
582 	EXT4_ERR_TRANSLATE(ENOSPC),
583 	EXT4_ERR_TRANSLATE(ENOKEY),
584 	EXT4_ERR_TRANSLATE(EROFS),
585 	EXT4_ERR_TRANSLATE(EFBIG),
586 	EXT4_ERR_TRANSLATE(EEXIST),
587 	EXT4_ERR_TRANSLATE(ERANGE),
588 	EXT4_ERR_TRANSLATE(EOVERFLOW),
589 	EXT4_ERR_TRANSLATE(EBUSY),
590 	EXT4_ERR_TRANSLATE(ENOTDIR),
591 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
592 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
593 	EXT4_ERR_TRANSLATE(EFAULT),
594 };
595 
596 static int ext4_errno_to_code(int errno)
597 {
598 	int i;
599 
600 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
601 		if (err_translation[i].errno == errno)
602 			return err_translation[i].code;
603 	return EXT4_ERR_UNKNOWN;
604 }
605 
606 static void save_error_info(struct super_block *sb, int error,
607 			    __u32 ino, __u64 block,
608 			    const char *func, unsigned int line)
609 {
610 	struct ext4_sb_info *sbi = EXT4_SB(sb);
611 
612 	/* We default to EFSCORRUPTED error... */
613 	if (error == 0)
614 		error = EFSCORRUPTED;
615 
616 	spin_lock(&sbi->s_error_lock);
617 	sbi->s_add_error_count++;
618 	sbi->s_last_error_code = error;
619 	sbi->s_last_error_line = line;
620 	sbi->s_last_error_ino = ino;
621 	sbi->s_last_error_block = block;
622 	sbi->s_last_error_func = func;
623 	sbi->s_last_error_time = ktime_get_real_seconds();
624 	if (!sbi->s_first_error_time) {
625 		sbi->s_first_error_code = error;
626 		sbi->s_first_error_line = line;
627 		sbi->s_first_error_ino = ino;
628 		sbi->s_first_error_block = block;
629 		sbi->s_first_error_func = func;
630 		sbi->s_first_error_time = sbi->s_last_error_time;
631 	}
632 	spin_unlock(&sbi->s_error_lock);
633 }
634 
635 /* Deal with the reporting of failure conditions on a filesystem such as
636  * inconsistencies detected or read IO failures.
637  *
638  * On ext2, we can store the error state of the filesystem in the
639  * superblock.  That is not possible on ext4, because we may have other
640  * write ordering constraints on the superblock which prevent us from
641  * writing it out straight away; and given that the journal is about to
642  * be aborted, we can't rely on the current, or future, transactions to
643  * write out the superblock safely.
644  *
645  * We'll just use the jbd2_journal_abort() error code to record an error in
646  * the journal instead.  On recovery, the journal will complain about
647  * that error until we've noted it down and cleared it.
648  *
649  * If force_ro is set, we unconditionally force the filesystem into an
650  * ABORT|READONLY state, unless the error response on the fs has been set to
651  * panic in which case we take the easy way out and panic immediately. This is
652  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
653  * at a critical moment in log management.
654  */
655 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
656 			      __u32 ino, __u64 block,
657 			      const char *func, unsigned int line)
658 {
659 	journal_t *journal = EXT4_SB(sb)->s_journal;
660 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
661 
662 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
663 	if (test_opt(sb, WARN_ON_ERROR))
664 		WARN_ON_ONCE(1);
665 
666 	if (!continue_fs && !sb_rdonly(sb)) {
667 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
668 		if (journal)
669 			jbd2_journal_abort(journal, -EIO);
670 	}
671 
672 	if (!bdev_read_only(sb->s_bdev)) {
673 		save_error_info(sb, error, ino, block, func, line);
674 		/*
675 		 * In case the fs should keep running, we need to writeout
676 		 * superblock through the journal. Due to lock ordering
677 		 * constraints, it may not be safe to do it right here so we
678 		 * defer superblock flushing to a workqueue.
679 		 */
680 		if (continue_fs && journal)
681 			schedule_work(&EXT4_SB(sb)->s_error_work);
682 		else
683 			ext4_commit_super(sb);
684 	}
685 
686 	/*
687 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
688 	 * could panic during 'reboot -f' as the underlying device got already
689 	 * disabled.
690 	 */
691 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
692 		panic("EXT4-fs (device %s): panic forced after error\n",
693 			sb->s_id);
694 	}
695 
696 	if (sb_rdonly(sb) || continue_fs)
697 		return;
698 
699 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
700 	/*
701 	 * Make sure updated value of ->s_mount_flags will be visible before
702 	 * ->s_flags update
703 	 */
704 	smp_wmb();
705 	sb->s_flags |= SB_RDONLY;
706 }
707 
708 static void flush_stashed_error_work(struct work_struct *work)
709 {
710 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
711 						s_error_work);
712 	journal_t *journal = sbi->s_journal;
713 	handle_t *handle;
714 
715 	/*
716 	 * If the journal is still running, we have to write out superblock
717 	 * through the journal to avoid collisions of other journalled sb
718 	 * updates.
719 	 *
720 	 * We use directly jbd2 functions here to avoid recursing back into
721 	 * ext4 error handling code during handling of previous errors.
722 	 */
723 	if (!sb_rdonly(sbi->s_sb) && journal) {
724 		struct buffer_head *sbh = sbi->s_sbh;
725 		handle = jbd2_journal_start(journal, 1);
726 		if (IS_ERR(handle))
727 			goto write_directly;
728 		if (jbd2_journal_get_write_access(handle, sbh)) {
729 			jbd2_journal_stop(handle);
730 			goto write_directly;
731 		}
732 		ext4_update_super(sbi->s_sb);
733 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
734 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
735 				 "superblock detected");
736 			clear_buffer_write_io_error(sbh);
737 			set_buffer_uptodate(sbh);
738 		}
739 
740 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
741 			jbd2_journal_stop(handle);
742 			goto write_directly;
743 		}
744 		jbd2_journal_stop(handle);
745 		ext4_notify_error_sysfs(sbi);
746 		return;
747 	}
748 write_directly:
749 	/*
750 	 * Write through journal failed. Write sb directly to get error info
751 	 * out and hope for the best.
752 	 */
753 	ext4_commit_super(sbi->s_sb);
754 	ext4_notify_error_sysfs(sbi);
755 }
756 
757 #define ext4_error_ratelimit(sb)					\
758 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
759 			     "EXT4-fs error")
760 
761 void __ext4_error(struct super_block *sb, const char *function,
762 		  unsigned int line, bool force_ro, int error, __u64 block,
763 		  const char *fmt, ...)
764 {
765 	struct va_format vaf;
766 	va_list args;
767 
768 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
769 		return;
770 
771 	trace_ext4_error(sb, function, line);
772 	if (ext4_error_ratelimit(sb)) {
773 		va_start(args, fmt);
774 		vaf.fmt = fmt;
775 		vaf.va = &args;
776 		printk(KERN_CRIT
777 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
778 		       sb->s_id, function, line, current->comm, &vaf);
779 		va_end(args);
780 	}
781 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
782 
783 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
784 }
785 
786 void __ext4_error_inode(struct inode *inode, const char *function,
787 			unsigned int line, ext4_fsblk_t block, int error,
788 			const char *fmt, ...)
789 {
790 	va_list args;
791 	struct va_format vaf;
792 
793 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
794 		return;
795 
796 	trace_ext4_error(inode->i_sb, function, line);
797 	if (ext4_error_ratelimit(inode->i_sb)) {
798 		va_start(args, fmt);
799 		vaf.fmt = fmt;
800 		vaf.va = &args;
801 		if (block)
802 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
803 			       "inode #%lu: block %llu: comm %s: %pV\n",
804 			       inode->i_sb->s_id, function, line, inode->i_ino,
805 			       block, current->comm, &vaf);
806 		else
807 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
808 			       "inode #%lu: comm %s: %pV\n",
809 			       inode->i_sb->s_id, function, line, inode->i_ino,
810 			       current->comm, &vaf);
811 		va_end(args);
812 	}
813 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
814 
815 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
816 			  function, line);
817 }
818 
819 void __ext4_error_file(struct file *file, const char *function,
820 		       unsigned int line, ext4_fsblk_t block,
821 		       const char *fmt, ...)
822 {
823 	va_list args;
824 	struct va_format vaf;
825 	struct inode *inode = file_inode(file);
826 	char pathname[80], *path;
827 
828 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
829 		return;
830 
831 	trace_ext4_error(inode->i_sb, function, line);
832 	if (ext4_error_ratelimit(inode->i_sb)) {
833 		path = file_path(file, pathname, sizeof(pathname));
834 		if (IS_ERR(path))
835 			path = "(unknown)";
836 		va_start(args, fmt);
837 		vaf.fmt = fmt;
838 		vaf.va = &args;
839 		if (block)
840 			printk(KERN_CRIT
841 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
842 			       "block %llu: comm %s: path %s: %pV\n",
843 			       inode->i_sb->s_id, function, line, inode->i_ino,
844 			       block, current->comm, path, &vaf);
845 		else
846 			printk(KERN_CRIT
847 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
848 			       "comm %s: path %s: %pV\n",
849 			       inode->i_sb->s_id, function, line, inode->i_ino,
850 			       current->comm, path, &vaf);
851 		va_end(args);
852 	}
853 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
854 
855 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
856 			  function, line);
857 }
858 
859 const char *ext4_decode_error(struct super_block *sb, int errno,
860 			      char nbuf[16])
861 {
862 	char *errstr = NULL;
863 
864 	switch (errno) {
865 	case -EFSCORRUPTED:
866 		errstr = "Corrupt filesystem";
867 		break;
868 	case -EFSBADCRC:
869 		errstr = "Filesystem failed CRC";
870 		break;
871 	case -EIO:
872 		errstr = "IO failure";
873 		break;
874 	case -ENOMEM:
875 		errstr = "Out of memory";
876 		break;
877 	case -EROFS:
878 		if (!sb || (EXT4_SB(sb)->s_journal &&
879 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
880 			errstr = "Journal has aborted";
881 		else
882 			errstr = "Readonly filesystem";
883 		break;
884 	default:
885 		/* If the caller passed in an extra buffer for unknown
886 		 * errors, textualise them now.  Else we just return
887 		 * NULL. */
888 		if (nbuf) {
889 			/* Check for truncated error codes... */
890 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
891 				errstr = nbuf;
892 		}
893 		break;
894 	}
895 
896 	return errstr;
897 }
898 
899 /* __ext4_std_error decodes expected errors from journaling functions
900  * automatically and invokes the appropriate error response.  */
901 
902 void __ext4_std_error(struct super_block *sb, const char *function,
903 		      unsigned int line, int errno)
904 {
905 	char nbuf[16];
906 	const char *errstr;
907 
908 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
909 		return;
910 
911 	/* Special case: if the error is EROFS, and we're not already
912 	 * inside a transaction, then there's really no point in logging
913 	 * an error. */
914 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
915 		return;
916 
917 	if (ext4_error_ratelimit(sb)) {
918 		errstr = ext4_decode_error(sb, errno, nbuf);
919 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
920 		       sb->s_id, function, line, errstr);
921 	}
922 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
923 
924 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
925 }
926 
927 void __ext4_msg(struct super_block *sb,
928 		const char *prefix, const char *fmt, ...)
929 {
930 	struct va_format vaf;
931 	va_list args;
932 
933 	if (sb) {
934 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
935 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
936 				  "EXT4-fs"))
937 			return;
938 	}
939 
940 	va_start(args, fmt);
941 	vaf.fmt = fmt;
942 	vaf.va = &args;
943 	if (sb)
944 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
945 	else
946 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
947 	va_end(args);
948 }
949 
950 static int ext4_warning_ratelimit(struct super_block *sb)
951 {
952 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
953 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
954 			    "EXT4-fs warning");
955 }
956 
957 void __ext4_warning(struct super_block *sb, const char *function,
958 		    unsigned int line, const char *fmt, ...)
959 {
960 	struct va_format vaf;
961 	va_list args;
962 
963 	if (!ext4_warning_ratelimit(sb))
964 		return;
965 
966 	va_start(args, fmt);
967 	vaf.fmt = fmt;
968 	vaf.va = &args;
969 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
970 	       sb->s_id, function, line, &vaf);
971 	va_end(args);
972 }
973 
974 void __ext4_warning_inode(const struct inode *inode, const char *function,
975 			  unsigned int line, const char *fmt, ...)
976 {
977 	struct va_format vaf;
978 	va_list args;
979 
980 	if (!ext4_warning_ratelimit(inode->i_sb))
981 		return;
982 
983 	va_start(args, fmt);
984 	vaf.fmt = fmt;
985 	vaf.va = &args;
986 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
987 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
988 	       function, line, inode->i_ino, current->comm, &vaf);
989 	va_end(args);
990 }
991 
992 void __ext4_grp_locked_error(const char *function, unsigned int line,
993 			     struct super_block *sb, ext4_group_t grp,
994 			     unsigned long ino, ext4_fsblk_t block,
995 			     const char *fmt, ...)
996 __releases(bitlock)
997 __acquires(bitlock)
998 {
999 	struct va_format vaf;
1000 	va_list args;
1001 
1002 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
1003 		return;
1004 
1005 	trace_ext4_error(sb, function, line);
1006 	if (ext4_error_ratelimit(sb)) {
1007 		va_start(args, fmt);
1008 		vaf.fmt = fmt;
1009 		vaf.va = &args;
1010 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1011 		       sb->s_id, function, line, grp);
1012 		if (ino)
1013 			printk(KERN_CONT "inode %lu: ", ino);
1014 		if (block)
1015 			printk(KERN_CONT "block %llu:",
1016 			       (unsigned long long) block);
1017 		printk(KERN_CONT "%pV\n", &vaf);
1018 		va_end(args);
1019 	}
1020 
1021 	if (test_opt(sb, ERRORS_CONT)) {
1022 		if (test_opt(sb, WARN_ON_ERROR))
1023 			WARN_ON_ONCE(1);
1024 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1025 		if (!bdev_read_only(sb->s_bdev)) {
1026 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1027 					line);
1028 			schedule_work(&EXT4_SB(sb)->s_error_work);
1029 		}
1030 		return;
1031 	}
1032 	ext4_unlock_group(sb, grp);
1033 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1034 	/*
1035 	 * We only get here in the ERRORS_RO case; relocking the group
1036 	 * may be dangerous, but nothing bad will happen since the
1037 	 * filesystem will have already been marked read/only and the
1038 	 * journal has been aborted.  We return 1 as a hint to callers
1039 	 * who might what to use the return value from
1040 	 * ext4_grp_locked_error() to distinguish between the
1041 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1042 	 * aggressively from the ext4 function in question, with a
1043 	 * more appropriate error code.
1044 	 */
1045 	ext4_lock_group(sb, grp);
1046 	return;
1047 }
1048 
1049 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1050 				     ext4_group_t group,
1051 				     unsigned int flags)
1052 {
1053 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1054 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1055 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1056 	int ret;
1057 
1058 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1059 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1060 					    &grp->bb_state);
1061 		if (!ret)
1062 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1063 					   grp->bb_free);
1064 	}
1065 
1066 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1067 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1068 					    &grp->bb_state);
1069 		if (!ret && gdp) {
1070 			int count;
1071 
1072 			count = ext4_free_inodes_count(sb, gdp);
1073 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1074 					   count);
1075 		}
1076 	}
1077 }
1078 
1079 void ext4_update_dynamic_rev(struct super_block *sb)
1080 {
1081 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1082 
1083 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1084 		return;
1085 
1086 	ext4_warning(sb,
1087 		     "updating to rev %d because of new feature flag, "
1088 		     "running e2fsck is recommended",
1089 		     EXT4_DYNAMIC_REV);
1090 
1091 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1092 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1093 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1094 	/* leave es->s_feature_*compat flags alone */
1095 	/* es->s_uuid will be set by e2fsck if empty */
1096 
1097 	/*
1098 	 * The rest of the superblock fields should be zero, and if not it
1099 	 * means they are likely already in use, so leave them alone.  We
1100 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1101 	 */
1102 }
1103 
1104 /*
1105  * Open the external journal device
1106  */
1107 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1108 {
1109 	struct block_device *bdev;
1110 
1111 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1112 	if (IS_ERR(bdev))
1113 		goto fail;
1114 	return bdev;
1115 
1116 fail:
1117 	ext4_msg(sb, KERN_ERR,
1118 		 "failed to open journal device unknown-block(%u,%u) %ld",
1119 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1120 	return NULL;
1121 }
1122 
1123 /*
1124  * Release the journal device
1125  */
1126 static void ext4_blkdev_put(struct block_device *bdev)
1127 {
1128 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1129 }
1130 
1131 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1132 {
1133 	struct block_device *bdev;
1134 	bdev = sbi->s_journal_bdev;
1135 	if (bdev) {
1136 		ext4_blkdev_put(bdev);
1137 		sbi->s_journal_bdev = NULL;
1138 	}
1139 }
1140 
1141 static inline struct inode *orphan_list_entry(struct list_head *l)
1142 {
1143 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1144 }
1145 
1146 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1147 {
1148 	struct list_head *l;
1149 
1150 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1151 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1152 
1153 	printk(KERN_ERR "sb_info orphan list:\n");
1154 	list_for_each(l, &sbi->s_orphan) {
1155 		struct inode *inode = orphan_list_entry(l);
1156 		printk(KERN_ERR "  "
1157 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1158 		       inode->i_sb->s_id, inode->i_ino, inode,
1159 		       inode->i_mode, inode->i_nlink,
1160 		       NEXT_ORPHAN(inode));
1161 	}
1162 }
1163 
1164 #ifdef CONFIG_QUOTA
1165 static int ext4_quota_off(struct super_block *sb, int type);
1166 
1167 static inline void ext4_quota_off_umount(struct super_block *sb)
1168 {
1169 	int type;
1170 
1171 	/* Use our quota_off function to clear inode flags etc. */
1172 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1173 		ext4_quota_off(sb, type);
1174 }
1175 
1176 /*
1177  * This is a helper function which is used in the mount/remount
1178  * codepaths (which holds s_umount) to fetch the quota file name.
1179  */
1180 static inline char *get_qf_name(struct super_block *sb,
1181 				struct ext4_sb_info *sbi,
1182 				int type)
1183 {
1184 	return rcu_dereference_protected(sbi->s_qf_names[type],
1185 					 lockdep_is_held(&sb->s_umount));
1186 }
1187 #else
1188 static inline void ext4_quota_off_umount(struct super_block *sb)
1189 {
1190 }
1191 #endif
1192 
1193 static void ext4_put_super(struct super_block *sb)
1194 {
1195 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1196 	struct ext4_super_block *es = sbi->s_es;
1197 	struct buffer_head **group_desc;
1198 	struct flex_groups **flex_groups;
1199 	int aborted = 0;
1200 	int i, err;
1201 
1202 	/*
1203 	 * Unregister sysfs before destroying jbd2 journal.
1204 	 * Since we could still access attr_journal_task attribute via sysfs
1205 	 * path which could have sbi->s_journal->j_task as NULL
1206 	 * Unregister sysfs before flush sbi->s_error_work.
1207 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1208 	 * read metadata verify failed then will queue error work.
1209 	 * flush_stashed_error_work will call start_this_handle may trigger
1210 	 * BUG_ON.
1211 	 */
1212 	ext4_unregister_sysfs(sb);
1213 
1214 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1215 		ext4_msg(sb, KERN_INFO, "unmounting filesystem.");
1216 
1217 	ext4_unregister_li_request(sb);
1218 	ext4_quota_off_umount(sb);
1219 
1220 	flush_work(&sbi->s_error_work);
1221 	destroy_workqueue(sbi->rsv_conversion_wq);
1222 	ext4_release_orphan_info(sb);
1223 
1224 	if (sbi->s_journal) {
1225 		aborted = is_journal_aborted(sbi->s_journal);
1226 		err = jbd2_journal_destroy(sbi->s_journal);
1227 		sbi->s_journal = NULL;
1228 		if ((err < 0) && !aborted) {
1229 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1230 		}
1231 	}
1232 
1233 	ext4_es_unregister_shrinker(sbi);
1234 	del_timer_sync(&sbi->s_err_report);
1235 	ext4_release_system_zone(sb);
1236 	ext4_mb_release(sb);
1237 	ext4_ext_release(sb);
1238 
1239 	if (!sb_rdonly(sb) && !aborted) {
1240 		ext4_clear_feature_journal_needs_recovery(sb);
1241 		ext4_clear_feature_orphan_present(sb);
1242 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1243 	}
1244 	if (!sb_rdonly(sb))
1245 		ext4_commit_super(sb);
1246 
1247 	rcu_read_lock();
1248 	group_desc = rcu_dereference(sbi->s_group_desc);
1249 	for (i = 0; i < sbi->s_gdb_count; i++)
1250 		brelse(group_desc[i]);
1251 	kvfree(group_desc);
1252 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1253 	if (flex_groups) {
1254 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1255 			kvfree(flex_groups[i]);
1256 		kvfree(flex_groups);
1257 	}
1258 	rcu_read_unlock();
1259 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1260 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1261 	percpu_counter_destroy(&sbi->s_dirs_counter);
1262 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1263 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1264 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1265 #ifdef CONFIG_QUOTA
1266 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1267 		kfree(get_qf_name(sb, sbi, i));
1268 #endif
1269 
1270 	/* Debugging code just in case the in-memory inode orphan list
1271 	 * isn't empty.  The on-disk one can be non-empty if we've
1272 	 * detected an error and taken the fs readonly, but the
1273 	 * in-memory list had better be clean by this point. */
1274 	if (!list_empty(&sbi->s_orphan))
1275 		dump_orphan_list(sb, sbi);
1276 	ASSERT(list_empty(&sbi->s_orphan));
1277 
1278 	sync_blockdev(sb->s_bdev);
1279 	invalidate_bdev(sb->s_bdev);
1280 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1281 		/*
1282 		 * Invalidate the journal device's buffers.  We don't want them
1283 		 * floating about in memory - the physical journal device may
1284 		 * hotswapped, and it breaks the `ro-after' testing code.
1285 		 */
1286 		sync_blockdev(sbi->s_journal_bdev);
1287 		invalidate_bdev(sbi->s_journal_bdev);
1288 		ext4_blkdev_remove(sbi);
1289 	}
1290 
1291 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1292 	sbi->s_ea_inode_cache = NULL;
1293 
1294 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1295 	sbi->s_ea_block_cache = NULL;
1296 
1297 	ext4_stop_mmpd(sbi);
1298 
1299 	brelse(sbi->s_sbh);
1300 	sb->s_fs_info = NULL;
1301 	/*
1302 	 * Now that we are completely done shutting down the
1303 	 * superblock, we need to actually destroy the kobject.
1304 	 */
1305 	kobject_put(&sbi->s_kobj);
1306 	wait_for_completion(&sbi->s_kobj_unregister);
1307 	if (sbi->s_chksum_driver)
1308 		crypto_free_shash(sbi->s_chksum_driver);
1309 	kfree(sbi->s_blockgroup_lock);
1310 	fs_put_dax(sbi->s_daxdev);
1311 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1312 #if IS_ENABLED(CONFIG_UNICODE)
1313 	utf8_unload(sb->s_encoding);
1314 #endif
1315 	kfree(sbi);
1316 }
1317 
1318 static struct kmem_cache *ext4_inode_cachep;
1319 
1320 /*
1321  * Called inside transaction, so use GFP_NOFS
1322  */
1323 static struct inode *ext4_alloc_inode(struct super_block *sb)
1324 {
1325 	struct ext4_inode_info *ei;
1326 
1327 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1328 	if (!ei)
1329 		return NULL;
1330 
1331 	inode_set_iversion(&ei->vfs_inode, 1);
1332 	spin_lock_init(&ei->i_raw_lock);
1333 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1334 	atomic_set(&ei->i_prealloc_active, 0);
1335 	spin_lock_init(&ei->i_prealloc_lock);
1336 	ext4_es_init_tree(&ei->i_es_tree);
1337 	rwlock_init(&ei->i_es_lock);
1338 	INIT_LIST_HEAD(&ei->i_es_list);
1339 	ei->i_es_all_nr = 0;
1340 	ei->i_es_shk_nr = 0;
1341 	ei->i_es_shrink_lblk = 0;
1342 	ei->i_reserved_data_blocks = 0;
1343 	spin_lock_init(&(ei->i_block_reservation_lock));
1344 	ext4_init_pending_tree(&ei->i_pending_tree);
1345 #ifdef CONFIG_QUOTA
1346 	ei->i_reserved_quota = 0;
1347 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1348 #endif
1349 	ei->jinode = NULL;
1350 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1351 	spin_lock_init(&ei->i_completed_io_lock);
1352 	ei->i_sync_tid = 0;
1353 	ei->i_datasync_tid = 0;
1354 	atomic_set(&ei->i_unwritten, 0);
1355 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1356 	ext4_fc_init_inode(&ei->vfs_inode);
1357 	mutex_init(&ei->i_fc_lock);
1358 	return &ei->vfs_inode;
1359 }
1360 
1361 static int ext4_drop_inode(struct inode *inode)
1362 {
1363 	int drop = generic_drop_inode(inode);
1364 
1365 	if (!drop)
1366 		drop = fscrypt_drop_inode(inode);
1367 
1368 	trace_ext4_drop_inode(inode, drop);
1369 	return drop;
1370 }
1371 
1372 static void ext4_free_in_core_inode(struct inode *inode)
1373 {
1374 	fscrypt_free_inode(inode);
1375 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1376 		pr_warn("%s: inode %ld still in fc list",
1377 			__func__, inode->i_ino);
1378 	}
1379 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1380 }
1381 
1382 static void ext4_destroy_inode(struct inode *inode)
1383 {
1384 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1385 		ext4_msg(inode->i_sb, KERN_ERR,
1386 			 "Inode %lu (%p): orphan list check failed!",
1387 			 inode->i_ino, EXT4_I(inode));
1388 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1389 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1390 				true);
1391 		dump_stack();
1392 	}
1393 
1394 	if (EXT4_I(inode)->i_reserved_data_blocks)
1395 		ext4_msg(inode->i_sb, KERN_ERR,
1396 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1397 			 inode->i_ino, EXT4_I(inode),
1398 			 EXT4_I(inode)->i_reserved_data_blocks);
1399 }
1400 
1401 static void init_once(void *foo)
1402 {
1403 	struct ext4_inode_info *ei = foo;
1404 
1405 	INIT_LIST_HEAD(&ei->i_orphan);
1406 	init_rwsem(&ei->xattr_sem);
1407 	init_rwsem(&ei->i_data_sem);
1408 	inode_init_once(&ei->vfs_inode);
1409 	ext4_fc_init_inode(&ei->vfs_inode);
1410 }
1411 
1412 static int __init init_inodecache(void)
1413 {
1414 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1415 				sizeof(struct ext4_inode_info), 0,
1416 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1417 					SLAB_ACCOUNT),
1418 				offsetof(struct ext4_inode_info, i_data),
1419 				sizeof_field(struct ext4_inode_info, i_data),
1420 				init_once);
1421 	if (ext4_inode_cachep == NULL)
1422 		return -ENOMEM;
1423 	return 0;
1424 }
1425 
1426 static void destroy_inodecache(void)
1427 {
1428 	/*
1429 	 * Make sure all delayed rcu free inodes are flushed before we
1430 	 * destroy cache.
1431 	 */
1432 	rcu_barrier();
1433 	kmem_cache_destroy(ext4_inode_cachep);
1434 }
1435 
1436 void ext4_clear_inode(struct inode *inode)
1437 {
1438 	ext4_fc_del(inode);
1439 	invalidate_inode_buffers(inode);
1440 	clear_inode(inode);
1441 	ext4_discard_preallocations(inode, 0);
1442 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1443 	dquot_drop(inode);
1444 	if (EXT4_I(inode)->jinode) {
1445 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1446 					       EXT4_I(inode)->jinode);
1447 		jbd2_free_inode(EXT4_I(inode)->jinode);
1448 		EXT4_I(inode)->jinode = NULL;
1449 	}
1450 	fscrypt_put_encryption_info(inode);
1451 	fsverity_cleanup_inode(inode);
1452 }
1453 
1454 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1455 					u64 ino, u32 generation)
1456 {
1457 	struct inode *inode;
1458 
1459 	/*
1460 	 * Currently we don't know the generation for parent directory, so
1461 	 * a generation of 0 means "accept any"
1462 	 */
1463 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1464 	if (IS_ERR(inode))
1465 		return ERR_CAST(inode);
1466 	if (generation && inode->i_generation != generation) {
1467 		iput(inode);
1468 		return ERR_PTR(-ESTALE);
1469 	}
1470 
1471 	return inode;
1472 }
1473 
1474 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1475 					int fh_len, int fh_type)
1476 {
1477 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1478 				    ext4_nfs_get_inode);
1479 }
1480 
1481 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1482 					int fh_len, int fh_type)
1483 {
1484 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1485 				    ext4_nfs_get_inode);
1486 }
1487 
1488 static int ext4_nfs_commit_metadata(struct inode *inode)
1489 {
1490 	struct writeback_control wbc = {
1491 		.sync_mode = WB_SYNC_ALL
1492 	};
1493 
1494 	trace_ext4_nfs_commit_metadata(inode);
1495 	return ext4_write_inode(inode, &wbc);
1496 }
1497 
1498 #ifdef CONFIG_QUOTA
1499 static const char * const quotatypes[] = INITQFNAMES;
1500 #define QTYPE2NAME(t) (quotatypes[t])
1501 
1502 static int ext4_write_dquot(struct dquot *dquot);
1503 static int ext4_acquire_dquot(struct dquot *dquot);
1504 static int ext4_release_dquot(struct dquot *dquot);
1505 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1506 static int ext4_write_info(struct super_block *sb, int type);
1507 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1508 			 const struct path *path);
1509 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1510 			       size_t len, loff_t off);
1511 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1512 				const char *data, size_t len, loff_t off);
1513 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1514 			     unsigned int flags);
1515 
1516 static struct dquot **ext4_get_dquots(struct inode *inode)
1517 {
1518 	return EXT4_I(inode)->i_dquot;
1519 }
1520 
1521 static const struct dquot_operations ext4_quota_operations = {
1522 	.get_reserved_space	= ext4_get_reserved_space,
1523 	.write_dquot		= ext4_write_dquot,
1524 	.acquire_dquot		= ext4_acquire_dquot,
1525 	.release_dquot		= ext4_release_dquot,
1526 	.mark_dirty		= ext4_mark_dquot_dirty,
1527 	.write_info		= ext4_write_info,
1528 	.alloc_dquot		= dquot_alloc,
1529 	.destroy_dquot		= dquot_destroy,
1530 	.get_projid		= ext4_get_projid,
1531 	.get_inode_usage	= ext4_get_inode_usage,
1532 	.get_next_id		= dquot_get_next_id,
1533 };
1534 
1535 static const struct quotactl_ops ext4_qctl_operations = {
1536 	.quota_on	= ext4_quota_on,
1537 	.quota_off	= ext4_quota_off,
1538 	.quota_sync	= dquot_quota_sync,
1539 	.get_state	= dquot_get_state,
1540 	.set_info	= dquot_set_dqinfo,
1541 	.get_dqblk	= dquot_get_dqblk,
1542 	.set_dqblk	= dquot_set_dqblk,
1543 	.get_nextdqblk	= dquot_get_next_dqblk,
1544 };
1545 #endif
1546 
1547 static const struct super_operations ext4_sops = {
1548 	.alloc_inode	= ext4_alloc_inode,
1549 	.free_inode	= ext4_free_in_core_inode,
1550 	.destroy_inode	= ext4_destroy_inode,
1551 	.write_inode	= ext4_write_inode,
1552 	.dirty_inode	= ext4_dirty_inode,
1553 	.drop_inode	= ext4_drop_inode,
1554 	.evict_inode	= ext4_evict_inode,
1555 	.put_super	= ext4_put_super,
1556 	.sync_fs	= ext4_sync_fs,
1557 	.freeze_fs	= ext4_freeze,
1558 	.unfreeze_fs	= ext4_unfreeze,
1559 	.statfs		= ext4_statfs,
1560 	.show_options	= ext4_show_options,
1561 #ifdef CONFIG_QUOTA
1562 	.quota_read	= ext4_quota_read,
1563 	.quota_write	= ext4_quota_write,
1564 	.get_dquots	= ext4_get_dquots,
1565 #endif
1566 };
1567 
1568 static const struct export_operations ext4_export_ops = {
1569 	.fh_to_dentry = ext4_fh_to_dentry,
1570 	.fh_to_parent = ext4_fh_to_parent,
1571 	.get_parent = ext4_get_parent,
1572 	.commit_metadata = ext4_nfs_commit_metadata,
1573 };
1574 
1575 enum {
1576 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1577 	Opt_resgid, Opt_resuid, Opt_sb,
1578 	Opt_nouid32, Opt_debug, Opt_removed,
1579 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1580 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1581 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1582 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1583 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1584 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1585 	Opt_inlinecrypt,
1586 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1587 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1588 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1589 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1590 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1591 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1592 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1593 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1594 	Opt_dioread_nolock, Opt_dioread_lock,
1595 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1596 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1597 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1598 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1599 #ifdef CONFIG_EXT4_DEBUG
1600 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1601 #endif
1602 };
1603 
1604 static const struct constant_table ext4_param_errors[] = {
1605 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1606 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1607 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1608 	{}
1609 };
1610 
1611 static const struct constant_table ext4_param_data[] = {
1612 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1613 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1614 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1615 	{}
1616 };
1617 
1618 static const struct constant_table ext4_param_data_err[] = {
1619 	{"abort",	Opt_data_err_abort},
1620 	{"ignore",	Opt_data_err_ignore},
1621 	{}
1622 };
1623 
1624 static const struct constant_table ext4_param_jqfmt[] = {
1625 	{"vfsold",	QFMT_VFS_OLD},
1626 	{"vfsv0",	QFMT_VFS_V0},
1627 	{"vfsv1",	QFMT_VFS_V1},
1628 	{}
1629 };
1630 
1631 static const struct constant_table ext4_param_dax[] = {
1632 	{"always",	Opt_dax_always},
1633 	{"inode",	Opt_dax_inode},
1634 	{"never",	Opt_dax_never},
1635 	{}
1636 };
1637 
1638 /* String parameter that allows empty argument */
1639 #define fsparam_string_empty(NAME, OPT) \
1640 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1641 
1642 /*
1643  * Mount option specification
1644  * We don't use fsparam_flag_no because of the way we set the
1645  * options and the way we show them in _ext4_show_options(). To
1646  * keep the changes to a minimum, let's keep the negative options
1647  * separate for now.
1648  */
1649 static const struct fs_parameter_spec ext4_param_specs[] = {
1650 	fsparam_flag	("bsddf",		Opt_bsd_df),
1651 	fsparam_flag	("minixdf",		Opt_minix_df),
1652 	fsparam_flag	("grpid",		Opt_grpid),
1653 	fsparam_flag	("bsdgroups",		Opt_grpid),
1654 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1655 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1656 	fsparam_u32	("resgid",		Opt_resgid),
1657 	fsparam_u32	("resuid",		Opt_resuid),
1658 	fsparam_u32	("sb",			Opt_sb),
1659 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1660 	fsparam_flag	("nouid32",		Opt_nouid32),
1661 	fsparam_flag	("debug",		Opt_debug),
1662 	fsparam_flag	("oldalloc",		Opt_removed),
1663 	fsparam_flag	("orlov",		Opt_removed),
1664 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1665 	fsparam_flag	("nouser_xattr",	Opt_nouser_xattr),
1666 	fsparam_flag	("acl",			Opt_acl),
1667 	fsparam_flag	("noacl",		Opt_noacl),
1668 	fsparam_flag	("norecovery",		Opt_noload),
1669 	fsparam_flag	("noload",		Opt_noload),
1670 	fsparam_flag	("bh",			Opt_removed),
1671 	fsparam_flag	("nobh",		Opt_removed),
1672 	fsparam_u32	("commit",		Opt_commit),
1673 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1674 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1675 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1676 	fsparam_bdev	("journal_path",	Opt_journal_path),
1677 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1678 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1679 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1680 	fsparam_flag	("abort",		Opt_abort),
1681 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1682 	fsparam_enum	("data_err",		Opt_data_err,
1683 						ext4_param_data_err),
1684 	fsparam_string_empty
1685 			("usrjquota",		Opt_usrjquota),
1686 	fsparam_string_empty
1687 			("grpjquota",		Opt_grpjquota),
1688 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1689 	fsparam_flag	("grpquota",		Opt_grpquota),
1690 	fsparam_flag	("quota",		Opt_quota),
1691 	fsparam_flag	("noquota",		Opt_noquota),
1692 	fsparam_flag	("usrquota",		Opt_usrquota),
1693 	fsparam_flag	("prjquota",		Opt_prjquota),
1694 	fsparam_flag	("barrier",		Opt_barrier),
1695 	fsparam_u32	("barrier",		Opt_barrier),
1696 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1697 	fsparam_flag	("i_version",		Opt_i_version),
1698 	fsparam_flag	("dax",			Opt_dax),
1699 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1700 	fsparam_u32	("stripe",		Opt_stripe),
1701 	fsparam_flag	("delalloc",		Opt_delalloc),
1702 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1703 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1704 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1705 	fsparam_u32	("debug_want_extra_isize",
1706 						Opt_debug_want_extra_isize),
1707 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1708 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1709 	fsparam_flag	("block_validity",	Opt_block_validity),
1710 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1711 	fsparam_u32	("inode_readahead_blks",
1712 						Opt_inode_readahead_blks),
1713 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1714 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1715 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1716 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1717 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1718 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1719 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1720 	fsparam_flag	("discard",		Opt_discard),
1721 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1722 	fsparam_u32	("init_itable",		Opt_init_itable),
1723 	fsparam_flag	("init_itable",		Opt_init_itable),
1724 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1725 #ifdef CONFIG_EXT4_DEBUG
1726 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1727 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1728 #endif
1729 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1730 	fsparam_flag	("test_dummy_encryption",
1731 						Opt_test_dummy_encryption),
1732 	fsparam_string	("test_dummy_encryption",
1733 						Opt_test_dummy_encryption),
1734 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1735 	fsparam_flag	("nombcache",		Opt_nombcache),
1736 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1737 	fsparam_flag	("prefetch_block_bitmaps",
1738 						Opt_removed),
1739 	fsparam_flag	("no_prefetch_block_bitmaps",
1740 						Opt_no_prefetch_block_bitmaps),
1741 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1742 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1743 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1744 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1745 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1746 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1747 	{}
1748 };
1749 
1750 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1751 
1752 static const char deprecated_msg[] =
1753 	"Mount option \"%s\" will be removed by %s\n"
1754 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1755 
1756 #define MOPT_SET	0x0001
1757 #define MOPT_CLEAR	0x0002
1758 #define MOPT_NOSUPPORT	0x0004
1759 #define MOPT_EXPLICIT	0x0008
1760 #ifdef CONFIG_QUOTA
1761 #define MOPT_Q		0
1762 #define MOPT_QFMT	0x0010
1763 #else
1764 #define MOPT_Q		MOPT_NOSUPPORT
1765 #define MOPT_QFMT	MOPT_NOSUPPORT
1766 #endif
1767 #define MOPT_NO_EXT2	0x0020
1768 #define MOPT_NO_EXT3	0x0040
1769 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1770 #define MOPT_SKIP	0x0080
1771 #define	MOPT_2		0x0100
1772 
1773 static const struct mount_opts {
1774 	int	token;
1775 	int	mount_opt;
1776 	int	flags;
1777 } ext4_mount_opts[] = {
1778 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1779 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1780 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1781 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1782 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1783 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1784 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1785 	 MOPT_EXT4_ONLY | MOPT_SET},
1786 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1787 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1788 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1789 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1790 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1791 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1792 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1793 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1794 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1795 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1796 	{Opt_commit, 0, MOPT_NO_EXT2},
1797 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1798 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1799 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1800 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1801 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1802 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1803 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1804 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1805 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1806 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1807 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1808 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1809 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1810 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1811 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1812 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1813 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1814 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1815 	{Opt_data, 0, MOPT_NO_EXT2},
1816 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1817 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1818 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1819 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1820 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1821 #else
1822 	{Opt_acl, 0, MOPT_NOSUPPORT},
1823 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1824 #endif
1825 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1826 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1827 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1828 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1829 							MOPT_SET | MOPT_Q},
1830 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1831 							MOPT_SET | MOPT_Q},
1832 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1833 							MOPT_SET | MOPT_Q},
1834 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1835 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1836 							MOPT_CLEAR | MOPT_Q},
1837 	{Opt_usrjquota, 0, MOPT_Q},
1838 	{Opt_grpjquota, 0, MOPT_Q},
1839 	{Opt_jqfmt, 0, MOPT_QFMT},
1840 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1841 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1842 	 MOPT_SET},
1843 #ifdef CONFIG_EXT4_DEBUG
1844 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1845 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1846 #endif
1847 	{Opt_err, 0, 0}
1848 };
1849 
1850 #if IS_ENABLED(CONFIG_UNICODE)
1851 static const struct ext4_sb_encodings {
1852 	__u16 magic;
1853 	char *name;
1854 	unsigned int version;
1855 } ext4_sb_encoding_map[] = {
1856 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1857 };
1858 
1859 static const struct ext4_sb_encodings *
1860 ext4_sb_read_encoding(const struct ext4_super_block *es)
1861 {
1862 	__u16 magic = le16_to_cpu(es->s_encoding);
1863 	int i;
1864 
1865 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1866 		if (magic == ext4_sb_encoding_map[i].magic)
1867 			return &ext4_sb_encoding_map[i];
1868 
1869 	return NULL;
1870 }
1871 #endif
1872 
1873 static int ext4_set_test_dummy_encryption(struct super_block *sb, char *arg)
1874 {
1875 #ifdef CONFIG_FS_ENCRYPTION
1876 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1877 	int err;
1878 
1879 	err = fscrypt_set_test_dummy_encryption(sb, arg,
1880 						&sbi->s_dummy_enc_policy);
1881 	if (err) {
1882 		ext4_msg(sb, KERN_WARNING,
1883 			 "Error while setting test dummy encryption [%d]", err);
1884 		return err;
1885 	}
1886 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
1887 #endif
1888 	return 0;
1889 }
1890 
1891 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1892 #define EXT4_SPEC_JQFMT				(1 <<  1)
1893 #define EXT4_SPEC_DATAJ				(1 <<  2)
1894 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1895 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1896 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1897 #define EXT4_SPEC_DUMMY_ENCRYPTION		(1 <<  6)
1898 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1899 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1900 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1901 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1902 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1903 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1904 #define EXT4_SPEC_s_stripe			(1 << 13)
1905 #define EXT4_SPEC_s_resuid			(1 << 14)
1906 #define EXT4_SPEC_s_resgid			(1 << 15)
1907 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1908 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1909 #define EXT4_SPEC_s_sb_block			(1 << 18)
1910 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1911 
1912 struct ext4_fs_context {
1913 	char		*s_qf_names[EXT4_MAXQUOTAS];
1914 	char		*test_dummy_enc_arg;
1915 	int		s_jquota_fmt;	/* Format of quota to use */
1916 #ifdef CONFIG_EXT4_DEBUG
1917 	int s_fc_debug_max_replay;
1918 #endif
1919 	unsigned short	qname_spec;
1920 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1921 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1922 	unsigned long	journal_devnum;
1923 	unsigned long	s_commit_interval;
1924 	unsigned long	s_stripe;
1925 	unsigned int	s_inode_readahead_blks;
1926 	unsigned int	s_want_extra_isize;
1927 	unsigned int	s_li_wait_mult;
1928 	unsigned int	s_max_dir_size_kb;
1929 	unsigned int	journal_ioprio;
1930 	unsigned int	vals_s_mount_opt;
1931 	unsigned int	mask_s_mount_opt;
1932 	unsigned int	vals_s_mount_opt2;
1933 	unsigned int	mask_s_mount_opt2;
1934 	unsigned long	vals_s_mount_flags;
1935 	unsigned long	mask_s_mount_flags;
1936 	unsigned int	opt_flags;	/* MOPT flags */
1937 	unsigned int	spec;
1938 	u32		s_max_batch_time;
1939 	u32		s_min_batch_time;
1940 	kuid_t		s_resuid;
1941 	kgid_t		s_resgid;
1942 	ext4_fsblk_t	s_sb_block;
1943 };
1944 
1945 static void ext4_fc_free(struct fs_context *fc)
1946 {
1947 	struct ext4_fs_context *ctx = fc->fs_private;
1948 	int i;
1949 
1950 	if (!ctx)
1951 		return;
1952 
1953 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1954 		kfree(ctx->s_qf_names[i]);
1955 
1956 	kfree(ctx->test_dummy_enc_arg);
1957 	kfree(ctx);
1958 }
1959 
1960 int ext4_init_fs_context(struct fs_context *fc)
1961 {
1962 	struct ext4_fs_context *ctx;
1963 
1964 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1965 	if (!ctx)
1966 		return -ENOMEM;
1967 
1968 	fc->fs_private = ctx;
1969 	fc->ops = &ext4_context_ops;
1970 
1971 	return 0;
1972 }
1973 
1974 #ifdef CONFIG_QUOTA
1975 /*
1976  * Note the name of the specified quota file.
1977  */
1978 static int note_qf_name(struct fs_context *fc, int qtype,
1979 		       struct fs_parameter *param)
1980 {
1981 	struct ext4_fs_context *ctx = fc->fs_private;
1982 	char *qname;
1983 
1984 	if (param->size < 1) {
1985 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
1986 		return -EINVAL;
1987 	}
1988 	if (strchr(param->string, '/')) {
1989 		ext4_msg(NULL, KERN_ERR,
1990 			 "quotafile must be on filesystem root");
1991 		return -EINVAL;
1992 	}
1993 	if (ctx->s_qf_names[qtype]) {
1994 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
1995 			ext4_msg(NULL, KERN_ERR,
1996 				 "%s quota file already specified",
1997 				 QTYPE2NAME(qtype));
1998 			return -EINVAL;
1999 		}
2000 		return 0;
2001 	}
2002 
2003 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2004 	if (!qname) {
2005 		ext4_msg(NULL, KERN_ERR,
2006 			 "Not enough memory for storing quotafile name");
2007 		return -ENOMEM;
2008 	}
2009 	ctx->s_qf_names[qtype] = qname;
2010 	ctx->qname_spec |= 1 << qtype;
2011 	ctx->spec |= EXT4_SPEC_JQUOTA;
2012 	return 0;
2013 }
2014 
2015 /*
2016  * Clear the name of the specified quota file.
2017  */
2018 static int unnote_qf_name(struct fs_context *fc, int qtype)
2019 {
2020 	struct ext4_fs_context *ctx = fc->fs_private;
2021 
2022 	if (ctx->s_qf_names[qtype])
2023 		kfree(ctx->s_qf_names[qtype]);
2024 
2025 	ctx->s_qf_names[qtype] = NULL;
2026 	ctx->qname_spec |= 1 << qtype;
2027 	ctx->spec |= EXT4_SPEC_JQUOTA;
2028 	return 0;
2029 }
2030 #endif
2031 
2032 #define EXT4_SET_CTX(name)						\
2033 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2034 				  unsigned long flag)			\
2035 {									\
2036 	ctx->mask_s_##name |= flag;					\
2037 	ctx->vals_s_##name |= flag;					\
2038 }
2039 
2040 #define EXT4_CLEAR_CTX(name)						\
2041 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2042 				    unsigned long flag)			\
2043 {									\
2044 	ctx->mask_s_##name |= flag;					\
2045 	ctx->vals_s_##name &= ~flag;					\
2046 }
2047 
2048 #define EXT4_TEST_CTX(name)						\
2049 static inline unsigned long						\
2050 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2051 {									\
2052 	return (ctx->vals_s_##name & flag);				\
2053 }
2054 
2055 EXT4_SET_CTX(flags); /* set only */
2056 EXT4_SET_CTX(mount_opt);
2057 EXT4_CLEAR_CTX(mount_opt);
2058 EXT4_TEST_CTX(mount_opt);
2059 EXT4_SET_CTX(mount_opt2);
2060 EXT4_CLEAR_CTX(mount_opt2);
2061 EXT4_TEST_CTX(mount_opt2);
2062 
2063 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2064 {
2065 	set_bit(bit, &ctx->mask_s_mount_flags);
2066 	set_bit(bit, &ctx->vals_s_mount_flags);
2067 }
2068 
2069 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2070 {
2071 	struct ext4_fs_context *ctx = fc->fs_private;
2072 	struct fs_parse_result result;
2073 	const struct mount_opts *m;
2074 	int is_remount;
2075 	kuid_t uid;
2076 	kgid_t gid;
2077 	int token;
2078 
2079 	token = fs_parse(fc, ext4_param_specs, param, &result);
2080 	if (token < 0)
2081 		return token;
2082 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2083 
2084 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2085 		if (token == m->token)
2086 			break;
2087 
2088 	ctx->opt_flags |= m->flags;
2089 
2090 	if (m->flags & MOPT_EXPLICIT) {
2091 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2092 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2093 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2094 			ctx_set_mount_opt2(ctx,
2095 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2096 		} else
2097 			return -EINVAL;
2098 	}
2099 
2100 	if (m->flags & MOPT_NOSUPPORT) {
2101 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2102 			 param->key);
2103 		return 0;
2104 	}
2105 
2106 	switch (token) {
2107 #ifdef CONFIG_QUOTA
2108 	case Opt_usrjquota:
2109 		if (!*param->string)
2110 			return unnote_qf_name(fc, USRQUOTA);
2111 		else
2112 			return note_qf_name(fc, USRQUOTA, param);
2113 	case Opt_grpjquota:
2114 		if (!*param->string)
2115 			return unnote_qf_name(fc, GRPQUOTA);
2116 		else
2117 			return note_qf_name(fc, GRPQUOTA, param);
2118 #endif
2119 	case Opt_noacl:
2120 	case Opt_nouser_xattr:
2121 		ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "3.5");
2122 		break;
2123 	case Opt_sb:
2124 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2125 			ext4_msg(NULL, KERN_WARNING,
2126 				 "Ignoring %s option on remount", param->key);
2127 		} else {
2128 			ctx->s_sb_block = result.uint_32;
2129 			ctx->spec |= EXT4_SPEC_s_sb_block;
2130 		}
2131 		return 0;
2132 	case Opt_removed:
2133 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2134 			 param->key);
2135 		return 0;
2136 	case Opt_abort:
2137 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2138 		return 0;
2139 	case Opt_i_version:
2140 		ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "5.20");
2141 		ext4_msg(NULL, KERN_WARNING, "Use iversion instead\n");
2142 		ctx_set_flags(ctx, SB_I_VERSION);
2143 		return 0;
2144 	case Opt_inlinecrypt:
2145 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2146 		ctx_set_flags(ctx, SB_INLINECRYPT);
2147 #else
2148 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2149 #endif
2150 		return 0;
2151 	case Opt_errors:
2152 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2153 		ctx_set_mount_opt(ctx, result.uint_32);
2154 		return 0;
2155 #ifdef CONFIG_QUOTA
2156 	case Opt_jqfmt:
2157 		ctx->s_jquota_fmt = result.uint_32;
2158 		ctx->spec |= EXT4_SPEC_JQFMT;
2159 		return 0;
2160 #endif
2161 	case Opt_data:
2162 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2163 		ctx_set_mount_opt(ctx, result.uint_32);
2164 		ctx->spec |= EXT4_SPEC_DATAJ;
2165 		return 0;
2166 	case Opt_commit:
2167 		if (result.uint_32 == 0)
2168 			ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2169 		else if (result.uint_32 > INT_MAX / HZ) {
2170 			ext4_msg(NULL, KERN_ERR,
2171 				 "Invalid commit interval %d, "
2172 				 "must be smaller than %d",
2173 				 result.uint_32, INT_MAX / HZ);
2174 			return -EINVAL;
2175 		}
2176 		ctx->s_commit_interval = HZ * result.uint_32;
2177 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2178 		return 0;
2179 	case Opt_debug_want_extra_isize:
2180 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2181 			ext4_msg(NULL, KERN_ERR,
2182 				 "Invalid want_extra_isize %d", result.uint_32);
2183 			return -EINVAL;
2184 		}
2185 		ctx->s_want_extra_isize = result.uint_32;
2186 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2187 		return 0;
2188 	case Opt_max_batch_time:
2189 		ctx->s_max_batch_time = result.uint_32;
2190 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2191 		return 0;
2192 	case Opt_min_batch_time:
2193 		ctx->s_min_batch_time = result.uint_32;
2194 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2195 		return 0;
2196 	case Opt_inode_readahead_blks:
2197 		if (result.uint_32 &&
2198 		    (result.uint_32 > (1 << 30) ||
2199 		     !is_power_of_2(result.uint_32))) {
2200 			ext4_msg(NULL, KERN_ERR,
2201 				 "EXT4-fs: inode_readahead_blks must be "
2202 				 "0 or a power of 2 smaller than 2^31");
2203 			return -EINVAL;
2204 		}
2205 		ctx->s_inode_readahead_blks = result.uint_32;
2206 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2207 		return 0;
2208 	case Opt_init_itable:
2209 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2210 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2211 		if (param->type == fs_value_is_string)
2212 			ctx->s_li_wait_mult = result.uint_32;
2213 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2214 		return 0;
2215 	case Opt_max_dir_size_kb:
2216 		ctx->s_max_dir_size_kb = result.uint_32;
2217 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2218 		return 0;
2219 #ifdef CONFIG_EXT4_DEBUG
2220 	case Opt_fc_debug_max_replay:
2221 		ctx->s_fc_debug_max_replay = result.uint_32;
2222 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2223 		return 0;
2224 #endif
2225 	case Opt_stripe:
2226 		ctx->s_stripe = result.uint_32;
2227 		ctx->spec |= EXT4_SPEC_s_stripe;
2228 		return 0;
2229 	case Opt_resuid:
2230 		uid = make_kuid(current_user_ns(), result.uint_32);
2231 		if (!uid_valid(uid)) {
2232 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2233 				 result.uint_32);
2234 			return -EINVAL;
2235 		}
2236 		ctx->s_resuid = uid;
2237 		ctx->spec |= EXT4_SPEC_s_resuid;
2238 		return 0;
2239 	case Opt_resgid:
2240 		gid = make_kgid(current_user_ns(), result.uint_32);
2241 		if (!gid_valid(gid)) {
2242 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2243 				 result.uint_32);
2244 			return -EINVAL;
2245 		}
2246 		ctx->s_resgid = gid;
2247 		ctx->spec |= EXT4_SPEC_s_resgid;
2248 		return 0;
2249 	case Opt_journal_dev:
2250 		if (is_remount) {
2251 			ext4_msg(NULL, KERN_ERR,
2252 				 "Cannot specify journal on remount");
2253 			return -EINVAL;
2254 		}
2255 		ctx->journal_devnum = result.uint_32;
2256 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2257 		return 0;
2258 	case Opt_journal_path:
2259 	{
2260 		struct inode *journal_inode;
2261 		struct path path;
2262 		int error;
2263 
2264 		if (is_remount) {
2265 			ext4_msg(NULL, KERN_ERR,
2266 				 "Cannot specify journal on remount");
2267 			return -EINVAL;
2268 		}
2269 
2270 		error = fs_lookup_param(fc, param, 1, &path);
2271 		if (error) {
2272 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2273 				 "journal device path");
2274 			return -EINVAL;
2275 		}
2276 
2277 		journal_inode = d_inode(path.dentry);
2278 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2279 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2280 		path_put(&path);
2281 		return 0;
2282 	}
2283 	case Opt_journal_ioprio:
2284 		if (result.uint_32 > 7) {
2285 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2286 				 " (must be 0-7)");
2287 			return -EINVAL;
2288 		}
2289 		ctx->journal_ioprio =
2290 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2291 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2292 		return 0;
2293 	case Opt_test_dummy_encryption:
2294 #ifdef CONFIG_FS_ENCRYPTION
2295 		if (param->type == fs_value_is_flag) {
2296 			ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
2297 			ctx->test_dummy_enc_arg = NULL;
2298 			return 0;
2299 		}
2300 		if (*param->string &&
2301 		    !(!strcmp(param->string, "v1") ||
2302 		      !strcmp(param->string, "v2"))) {
2303 			ext4_msg(NULL, KERN_WARNING,
2304 				 "Value of option \"%s\" is unrecognized",
2305 				 param->key);
2306 			return -EINVAL;
2307 		}
2308 		ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
2309 		ctx->test_dummy_enc_arg = kmemdup_nul(param->string, param->size,
2310 						      GFP_KERNEL);
2311 		return 0;
2312 #else
2313 		ext4_msg(NULL, KERN_WARNING,
2314 			 "test_dummy_encryption option not supported");
2315 		return -EINVAL;
2316 #endif
2317 	case Opt_dax:
2318 	case Opt_dax_type:
2319 #ifdef CONFIG_FS_DAX
2320 	{
2321 		int type = (token == Opt_dax) ?
2322 			   Opt_dax : result.uint_32;
2323 
2324 		switch (type) {
2325 		case Opt_dax:
2326 		case Opt_dax_always:
2327 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2328 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2329 			break;
2330 		case Opt_dax_never:
2331 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2332 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2333 			break;
2334 		case Opt_dax_inode:
2335 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2336 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2337 			/* Strictly for printing options */
2338 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2339 			break;
2340 		}
2341 		return 0;
2342 	}
2343 #else
2344 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2345 		return -EINVAL;
2346 #endif
2347 	case Opt_data_err:
2348 		if (result.uint_32 == Opt_data_err_abort)
2349 			ctx_set_mount_opt(ctx, m->mount_opt);
2350 		else if (result.uint_32 == Opt_data_err_ignore)
2351 			ctx_clear_mount_opt(ctx, m->mount_opt);
2352 		return 0;
2353 	case Opt_mb_optimize_scan:
2354 		if (result.int_32 == 1) {
2355 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2356 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2357 		} else if (result.int_32 == 0) {
2358 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2359 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2360 		} else {
2361 			ext4_msg(NULL, KERN_WARNING,
2362 				 "mb_optimize_scan should be set to 0 or 1.");
2363 			return -EINVAL;
2364 		}
2365 		return 0;
2366 	}
2367 
2368 	/*
2369 	 * At this point we should only be getting options requiring MOPT_SET,
2370 	 * or MOPT_CLEAR. Anything else is a bug
2371 	 */
2372 	if (m->token == Opt_err) {
2373 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2374 			 param->key);
2375 		WARN_ON(1);
2376 		return -EINVAL;
2377 	}
2378 
2379 	else {
2380 		unsigned int set = 0;
2381 
2382 		if ((param->type == fs_value_is_flag) ||
2383 		    result.uint_32 > 0)
2384 			set = 1;
2385 
2386 		if (m->flags & MOPT_CLEAR)
2387 			set = !set;
2388 		else if (unlikely(!(m->flags & MOPT_SET))) {
2389 			ext4_msg(NULL, KERN_WARNING,
2390 				 "buggy handling of option %s",
2391 				 param->key);
2392 			WARN_ON(1);
2393 			return -EINVAL;
2394 		}
2395 		if (m->flags & MOPT_2) {
2396 			if (set != 0)
2397 				ctx_set_mount_opt2(ctx, m->mount_opt);
2398 			else
2399 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2400 		} else {
2401 			if (set != 0)
2402 				ctx_set_mount_opt(ctx, m->mount_opt);
2403 			else
2404 				ctx_clear_mount_opt(ctx, m->mount_opt);
2405 		}
2406 	}
2407 
2408 	return 0;
2409 }
2410 
2411 static int parse_options(struct fs_context *fc, char *options)
2412 {
2413 	struct fs_parameter param;
2414 	int ret;
2415 	char *key;
2416 
2417 	if (!options)
2418 		return 0;
2419 
2420 	while ((key = strsep(&options, ",")) != NULL) {
2421 		if (*key) {
2422 			size_t v_len = 0;
2423 			char *value = strchr(key, '=');
2424 
2425 			param.type = fs_value_is_flag;
2426 			param.string = NULL;
2427 
2428 			if (value) {
2429 				if (value == key)
2430 					continue;
2431 
2432 				*value++ = 0;
2433 				v_len = strlen(value);
2434 				param.string = kmemdup_nul(value, v_len,
2435 							   GFP_KERNEL);
2436 				if (!param.string)
2437 					return -ENOMEM;
2438 				param.type = fs_value_is_string;
2439 			}
2440 
2441 			param.key = key;
2442 			param.size = v_len;
2443 
2444 			ret = ext4_parse_param(fc, &param);
2445 			if (param.string)
2446 				kfree(param.string);
2447 			if (ret < 0)
2448 				return ret;
2449 		}
2450 	}
2451 
2452 	ret = ext4_validate_options(fc);
2453 	if (ret < 0)
2454 		return ret;
2455 
2456 	return 0;
2457 }
2458 
2459 static int parse_apply_sb_mount_options(struct super_block *sb,
2460 					struct ext4_fs_context *m_ctx)
2461 {
2462 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2463 	char *s_mount_opts = NULL;
2464 	struct ext4_fs_context *s_ctx = NULL;
2465 	struct fs_context *fc = NULL;
2466 	int ret = -ENOMEM;
2467 
2468 	if (!sbi->s_es->s_mount_opts[0])
2469 		return 0;
2470 
2471 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2472 				sizeof(sbi->s_es->s_mount_opts),
2473 				GFP_KERNEL);
2474 	if (!s_mount_opts)
2475 		return ret;
2476 
2477 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2478 	if (!fc)
2479 		goto out_free;
2480 
2481 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2482 	if (!s_ctx)
2483 		goto out_free;
2484 
2485 	fc->fs_private = s_ctx;
2486 	fc->s_fs_info = sbi;
2487 
2488 	ret = parse_options(fc, s_mount_opts);
2489 	if (ret < 0)
2490 		goto parse_failed;
2491 
2492 	ret = ext4_check_opt_consistency(fc, sb);
2493 	if (ret < 0) {
2494 parse_failed:
2495 		ext4_msg(sb, KERN_WARNING,
2496 			 "failed to parse options in superblock: %s",
2497 			 s_mount_opts);
2498 		ret = 0;
2499 		goto out_free;
2500 	}
2501 
2502 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2503 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2504 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2505 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2506 
2507 	ret = ext4_apply_options(fc, sb);
2508 
2509 out_free:
2510 	if (fc) {
2511 		ext4_fc_free(fc);
2512 		kfree(fc);
2513 	}
2514 	kfree(s_mount_opts);
2515 	return ret;
2516 }
2517 
2518 static void ext4_apply_quota_options(struct fs_context *fc,
2519 				     struct super_block *sb)
2520 {
2521 #ifdef CONFIG_QUOTA
2522 	bool quota_feature = ext4_has_feature_quota(sb);
2523 	struct ext4_fs_context *ctx = fc->fs_private;
2524 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2525 	char *qname;
2526 	int i;
2527 
2528 	if (quota_feature)
2529 		return;
2530 
2531 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2532 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2533 			if (!(ctx->qname_spec & (1 << i)))
2534 				continue;
2535 
2536 			qname = ctx->s_qf_names[i]; /* May be NULL */
2537 			if (qname)
2538 				set_opt(sb, QUOTA);
2539 			ctx->s_qf_names[i] = NULL;
2540 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2541 						lockdep_is_held(&sb->s_umount));
2542 			if (qname)
2543 				kfree_rcu(qname);
2544 		}
2545 	}
2546 
2547 	if (ctx->spec & EXT4_SPEC_JQFMT)
2548 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2549 #endif
2550 }
2551 
2552 /*
2553  * Check quota settings consistency.
2554  */
2555 static int ext4_check_quota_consistency(struct fs_context *fc,
2556 					struct super_block *sb)
2557 {
2558 #ifdef CONFIG_QUOTA
2559 	struct ext4_fs_context *ctx = fc->fs_private;
2560 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2561 	bool quota_feature = ext4_has_feature_quota(sb);
2562 	bool quota_loaded = sb_any_quota_loaded(sb);
2563 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2564 	int quota_flags, i;
2565 
2566 	/*
2567 	 * We do the test below only for project quotas. 'usrquota' and
2568 	 * 'grpquota' mount options are allowed even without quota feature
2569 	 * to support legacy quotas in quota files.
2570 	 */
2571 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2572 	    !ext4_has_feature_project(sb)) {
2573 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2574 			 "Cannot enable project quota enforcement.");
2575 		return -EINVAL;
2576 	}
2577 
2578 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2579 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2580 	if (quota_loaded &&
2581 	    ctx->mask_s_mount_opt & quota_flags &&
2582 	    !ctx_test_mount_opt(ctx, quota_flags))
2583 		goto err_quota_change;
2584 
2585 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2586 
2587 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2588 			if (!(ctx->qname_spec & (1 << i)))
2589 				continue;
2590 
2591 			if (quota_loaded &&
2592 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2593 				goto err_jquota_change;
2594 
2595 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2596 			    strcmp(get_qf_name(sb, sbi, i),
2597 				   ctx->s_qf_names[i]) != 0)
2598 				goto err_jquota_specified;
2599 		}
2600 
2601 		if (quota_feature) {
2602 			ext4_msg(NULL, KERN_INFO,
2603 				 "Journaled quota options ignored when "
2604 				 "QUOTA feature is enabled");
2605 			return 0;
2606 		}
2607 	}
2608 
2609 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2610 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2611 			goto err_jquota_change;
2612 		if (quota_feature) {
2613 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2614 				 "ignored when QUOTA feature is enabled");
2615 			return 0;
2616 		}
2617 	}
2618 
2619 	/* Make sure we don't mix old and new quota format */
2620 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2621 		       ctx->s_qf_names[USRQUOTA]);
2622 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2623 		       ctx->s_qf_names[GRPQUOTA]);
2624 
2625 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2626 		    test_opt(sb, USRQUOTA));
2627 
2628 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2629 		    test_opt(sb, GRPQUOTA));
2630 
2631 	if (usr_qf_name) {
2632 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2633 		usrquota = false;
2634 	}
2635 	if (grp_qf_name) {
2636 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2637 		grpquota = false;
2638 	}
2639 
2640 	if (usr_qf_name || grp_qf_name) {
2641 		if (usrquota || grpquota) {
2642 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2643 				 "format mixing");
2644 			return -EINVAL;
2645 		}
2646 
2647 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2648 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2649 				 "not specified");
2650 			return -EINVAL;
2651 		}
2652 	}
2653 
2654 	return 0;
2655 
2656 err_quota_change:
2657 	ext4_msg(NULL, KERN_ERR,
2658 		 "Cannot change quota options when quota turned on");
2659 	return -EINVAL;
2660 err_jquota_change:
2661 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2662 		 "options when quota turned on");
2663 	return -EINVAL;
2664 err_jquota_specified:
2665 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2666 		 QTYPE2NAME(i));
2667 	return -EINVAL;
2668 #else
2669 	return 0;
2670 #endif
2671 }
2672 
2673 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2674 					    struct super_block *sb)
2675 {
2676 #ifdef CONFIG_FS_ENCRYPTION
2677 	const struct ext4_fs_context *ctx = fc->fs_private;
2678 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2679 
2680 	if (!(ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION))
2681 		return 0;
2682 
2683 	if (!ext4_has_feature_encrypt(sb)) {
2684 		ext4_msg(NULL, KERN_WARNING,
2685 			 "test_dummy_encryption requires encrypt feature");
2686 		return -EINVAL;
2687 	}
2688 	/*
2689 	 * This mount option is just for testing, and it's not worthwhile to
2690 	 * implement the extra complexity (e.g. RCU protection) that would be
2691 	 * needed to allow it to be set or changed during remount.  We do allow
2692 	 * it to be specified during remount, but only if there is no change.
2693 	 */
2694 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE &&
2695 	    !sbi->s_dummy_enc_policy.policy) {
2696 		ext4_msg(NULL, KERN_WARNING,
2697 			 "Can't set test_dummy_encryption on remount");
2698 		return -EINVAL;
2699 	}
2700 #endif /* CONFIG_FS_ENCRYPTION */
2701 	return 0;
2702 }
2703 
2704 static int ext4_check_opt_consistency(struct fs_context *fc,
2705 				      struct super_block *sb)
2706 {
2707 	struct ext4_fs_context *ctx = fc->fs_private;
2708 	struct ext4_sb_info *sbi = fc->s_fs_info;
2709 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2710 	int err;
2711 
2712 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2713 		ext4_msg(NULL, KERN_ERR,
2714 			 "Mount option(s) incompatible with ext2");
2715 		return -EINVAL;
2716 	}
2717 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2718 		ext4_msg(NULL, KERN_ERR,
2719 			 "Mount option(s) incompatible with ext3");
2720 		return -EINVAL;
2721 	}
2722 
2723 	if (ctx->s_want_extra_isize >
2724 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2725 		ext4_msg(NULL, KERN_ERR,
2726 			 "Invalid want_extra_isize %d",
2727 			 ctx->s_want_extra_isize);
2728 		return -EINVAL;
2729 	}
2730 
2731 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2732 		int blocksize =
2733 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2734 		if (blocksize < PAGE_SIZE)
2735 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2736 				 "experimental mount option 'dioread_nolock' "
2737 				 "for blocksize < PAGE_SIZE");
2738 	}
2739 
2740 	err = ext4_check_test_dummy_encryption(fc, sb);
2741 	if (err)
2742 		return err;
2743 
2744 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2745 		if (!sbi->s_journal) {
2746 			ext4_msg(NULL, KERN_WARNING,
2747 				 "Remounting file system with no journal "
2748 				 "so ignoring journalled data option");
2749 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2750 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2751 			   test_opt(sb, DATA_FLAGS)) {
2752 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2753 				 "on remount");
2754 			return -EINVAL;
2755 		}
2756 	}
2757 
2758 	if (is_remount) {
2759 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2760 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2761 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2762 				 "both data=journal and dax");
2763 			return -EINVAL;
2764 		}
2765 
2766 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2767 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2768 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2769 fail_dax_change_remount:
2770 			ext4_msg(NULL, KERN_ERR, "can't change "
2771 				 "dax mount option while remounting");
2772 			return -EINVAL;
2773 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2774 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2775 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2776 			goto fail_dax_change_remount;
2777 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2778 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2779 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2780 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2781 			goto fail_dax_change_remount;
2782 		}
2783 	}
2784 
2785 	return ext4_check_quota_consistency(fc, sb);
2786 }
2787 
2788 static int ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2789 {
2790 	struct ext4_fs_context *ctx = fc->fs_private;
2791 	struct ext4_sb_info *sbi = fc->s_fs_info;
2792 	int ret = 0;
2793 
2794 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2795 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2796 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2797 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2798 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2799 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2800 	sb->s_flags &= ~ctx->mask_s_flags;
2801 	sb->s_flags |= ctx->vals_s_flags;
2802 
2803 	/*
2804 	 * i_version differs from common mount option iversion so we have
2805 	 * to let vfs know that it was set, otherwise it would get cleared
2806 	 * on remount
2807 	 */
2808 	if (ctx->mask_s_flags & SB_I_VERSION)
2809 		fc->sb_flags |= SB_I_VERSION;
2810 
2811 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2812 	APPLY(s_commit_interval);
2813 	APPLY(s_stripe);
2814 	APPLY(s_max_batch_time);
2815 	APPLY(s_min_batch_time);
2816 	APPLY(s_want_extra_isize);
2817 	APPLY(s_inode_readahead_blks);
2818 	APPLY(s_max_dir_size_kb);
2819 	APPLY(s_li_wait_mult);
2820 	APPLY(s_resgid);
2821 	APPLY(s_resuid);
2822 
2823 #ifdef CONFIG_EXT4_DEBUG
2824 	APPLY(s_fc_debug_max_replay);
2825 #endif
2826 
2827 	ext4_apply_quota_options(fc, sb);
2828 
2829 	if (ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION)
2830 		ret = ext4_set_test_dummy_encryption(sb, ctx->test_dummy_enc_arg);
2831 
2832 	return ret;
2833 }
2834 
2835 
2836 static int ext4_validate_options(struct fs_context *fc)
2837 {
2838 #ifdef CONFIG_QUOTA
2839 	struct ext4_fs_context *ctx = fc->fs_private;
2840 	char *usr_qf_name, *grp_qf_name;
2841 
2842 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2843 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2844 
2845 	if (usr_qf_name || grp_qf_name) {
2846 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2847 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2848 
2849 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2850 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2851 
2852 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2853 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2854 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2855 				 "format mixing");
2856 			return -EINVAL;
2857 		}
2858 	}
2859 #endif
2860 	return 1;
2861 }
2862 
2863 static inline void ext4_show_quota_options(struct seq_file *seq,
2864 					   struct super_block *sb)
2865 {
2866 #if defined(CONFIG_QUOTA)
2867 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2868 	char *usr_qf_name, *grp_qf_name;
2869 
2870 	if (sbi->s_jquota_fmt) {
2871 		char *fmtname = "";
2872 
2873 		switch (sbi->s_jquota_fmt) {
2874 		case QFMT_VFS_OLD:
2875 			fmtname = "vfsold";
2876 			break;
2877 		case QFMT_VFS_V0:
2878 			fmtname = "vfsv0";
2879 			break;
2880 		case QFMT_VFS_V1:
2881 			fmtname = "vfsv1";
2882 			break;
2883 		}
2884 		seq_printf(seq, ",jqfmt=%s", fmtname);
2885 	}
2886 
2887 	rcu_read_lock();
2888 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2889 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2890 	if (usr_qf_name)
2891 		seq_show_option(seq, "usrjquota", usr_qf_name);
2892 	if (grp_qf_name)
2893 		seq_show_option(seq, "grpjquota", grp_qf_name);
2894 	rcu_read_unlock();
2895 #endif
2896 }
2897 
2898 static const char *token2str(int token)
2899 {
2900 	const struct fs_parameter_spec *spec;
2901 
2902 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2903 		if (spec->opt == token && !spec->type)
2904 			break;
2905 	return spec->name;
2906 }
2907 
2908 /*
2909  * Show an option if
2910  *  - it's set to a non-default value OR
2911  *  - if the per-sb default is different from the global default
2912  */
2913 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2914 			      int nodefs)
2915 {
2916 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2917 	struct ext4_super_block *es = sbi->s_es;
2918 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2919 	const struct mount_opts *m;
2920 	char sep = nodefs ? '\n' : ',';
2921 
2922 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2923 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2924 
2925 	if (sbi->s_sb_block != 1)
2926 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2927 
2928 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2929 		int want_set = m->flags & MOPT_SET;
2930 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2931 		    m->flags & MOPT_SKIP)
2932 			continue;
2933 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2934 			continue; /* skip if same as the default */
2935 		if ((want_set &&
2936 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2937 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2938 			continue; /* select Opt_noFoo vs Opt_Foo */
2939 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2940 	}
2941 
2942 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2943 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2944 		SEQ_OPTS_PRINT("resuid=%u",
2945 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2946 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2947 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2948 		SEQ_OPTS_PRINT("resgid=%u",
2949 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2950 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2951 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2952 		SEQ_OPTS_PUTS("errors=remount-ro");
2953 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2954 		SEQ_OPTS_PUTS("errors=continue");
2955 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2956 		SEQ_OPTS_PUTS("errors=panic");
2957 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2958 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2959 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2960 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2961 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2962 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2963 	if (sb->s_flags & SB_I_VERSION)
2964 		SEQ_OPTS_PUTS("i_version");
2965 	if (nodefs || sbi->s_stripe)
2966 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2967 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2968 			(sbi->s_mount_opt ^ def_mount_opt)) {
2969 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2970 			SEQ_OPTS_PUTS("data=journal");
2971 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2972 			SEQ_OPTS_PUTS("data=ordered");
2973 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2974 			SEQ_OPTS_PUTS("data=writeback");
2975 	}
2976 	if (nodefs ||
2977 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2978 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2979 			       sbi->s_inode_readahead_blks);
2980 
2981 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2982 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2983 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2984 	if (nodefs || sbi->s_max_dir_size_kb)
2985 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2986 	if (test_opt(sb, DATA_ERR_ABORT))
2987 		SEQ_OPTS_PUTS("data_err=abort");
2988 
2989 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2990 
2991 	if (sb->s_flags & SB_INLINECRYPT)
2992 		SEQ_OPTS_PUTS("inlinecrypt");
2993 
2994 	if (test_opt(sb, DAX_ALWAYS)) {
2995 		if (IS_EXT2_SB(sb))
2996 			SEQ_OPTS_PUTS("dax");
2997 		else
2998 			SEQ_OPTS_PUTS("dax=always");
2999 	} else if (test_opt2(sb, DAX_NEVER)) {
3000 		SEQ_OPTS_PUTS("dax=never");
3001 	} else if (test_opt2(sb, DAX_INODE)) {
3002 		SEQ_OPTS_PUTS("dax=inode");
3003 	}
3004 	ext4_show_quota_options(seq, sb);
3005 	return 0;
3006 }
3007 
3008 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3009 {
3010 	return _ext4_show_options(seq, root->d_sb, 0);
3011 }
3012 
3013 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3014 {
3015 	struct super_block *sb = seq->private;
3016 	int rc;
3017 
3018 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3019 	rc = _ext4_show_options(seq, sb, 1);
3020 	seq_puts(seq, "\n");
3021 	return rc;
3022 }
3023 
3024 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3025 			    int read_only)
3026 {
3027 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3028 	int err = 0;
3029 
3030 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3031 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3032 			 "forcing read-only mode");
3033 		err = -EROFS;
3034 		goto done;
3035 	}
3036 	if (read_only)
3037 		goto done;
3038 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3039 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3040 			 "running e2fsck is recommended");
3041 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3042 		ext4_msg(sb, KERN_WARNING,
3043 			 "warning: mounting fs with errors, "
3044 			 "running e2fsck is recommended");
3045 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3046 		 le16_to_cpu(es->s_mnt_count) >=
3047 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3048 		ext4_msg(sb, KERN_WARNING,
3049 			 "warning: maximal mount count reached, "
3050 			 "running e2fsck is recommended");
3051 	else if (le32_to_cpu(es->s_checkinterval) &&
3052 		 (ext4_get_tstamp(es, s_lastcheck) +
3053 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3054 		ext4_msg(sb, KERN_WARNING,
3055 			 "warning: checktime reached, "
3056 			 "running e2fsck is recommended");
3057 	if (!sbi->s_journal)
3058 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3059 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3060 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3061 	le16_add_cpu(&es->s_mnt_count, 1);
3062 	ext4_update_tstamp(es, s_mtime);
3063 	if (sbi->s_journal) {
3064 		ext4_set_feature_journal_needs_recovery(sb);
3065 		if (ext4_has_feature_orphan_file(sb))
3066 			ext4_set_feature_orphan_present(sb);
3067 	}
3068 
3069 	err = ext4_commit_super(sb);
3070 done:
3071 	if (test_opt(sb, DEBUG))
3072 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3073 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3074 			sb->s_blocksize,
3075 			sbi->s_groups_count,
3076 			EXT4_BLOCKS_PER_GROUP(sb),
3077 			EXT4_INODES_PER_GROUP(sb),
3078 			sbi->s_mount_opt, sbi->s_mount_opt2);
3079 	return err;
3080 }
3081 
3082 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3083 {
3084 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3085 	struct flex_groups **old_groups, **new_groups;
3086 	int size, i, j;
3087 
3088 	if (!sbi->s_log_groups_per_flex)
3089 		return 0;
3090 
3091 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3092 	if (size <= sbi->s_flex_groups_allocated)
3093 		return 0;
3094 
3095 	new_groups = kvzalloc(roundup_pow_of_two(size *
3096 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3097 	if (!new_groups) {
3098 		ext4_msg(sb, KERN_ERR,
3099 			 "not enough memory for %d flex group pointers", size);
3100 		return -ENOMEM;
3101 	}
3102 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3103 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3104 					 sizeof(struct flex_groups)),
3105 					 GFP_KERNEL);
3106 		if (!new_groups[i]) {
3107 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3108 				kvfree(new_groups[j]);
3109 			kvfree(new_groups);
3110 			ext4_msg(sb, KERN_ERR,
3111 				 "not enough memory for %d flex groups", size);
3112 			return -ENOMEM;
3113 		}
3114 	}
3115 	rcu_read_lock();
3116 	old_groups = rcu_dereference(sbi->s_flex_groups);
3117 	if (old_groups)
3118 		memcpy(new_groups, old_groups,
3119 		       (sbi->s_flex_groups_allocated *
3120 			sizeof(struct flex_groups *)));
3121 	rcu_read_unlock();
3122 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3123 	sbi->s_flex_groups_allocated = size;
3124 	if (old_groups)
3125 		ext4_kvfree_array_rcu(old_groups);
3126 	return 0;
3127 }
3128 
3129 static int ext4_fill_flex_info(struct super_block *sb)
3130 {
3131 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3132 	struct ext4_group_desc *gdp = NULL;
3133 	struct flex_groups *fg;
3134 	ext4_group_t flex_group;
3135 	int i, err;
3136 
3137 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3138 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3139 		sbi->s_log_groups_per_flex = 0;
3140 		return 1;
3141 	}
3142 
3143 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3144 	if (err)
3145 		goto failed;
3146 
3147 	for (i = 0; i < sbi->s_groups_count; i++) {
3148 		gdp = ext4_get_group_desc(sb, i, NULL);
3149 
3150 		flex_group = ext4_flex_group(sbi, i);
3151 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3152 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3153 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3154 			     &fg->free_clusters);
3155 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3156 	}
3157 
3158 	return 1;
3159 failed:
3160 	return 0;
3161 }
3162 
3163 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3164 				   struct ext4_group_desc *gdp)
3165 {
3166 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3167 	__u16 crc = 0;
3168 	__le32 le_group = cpu_to_le32(block_group);
3169 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3170 
3171 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3172 		/* Use new metadata_csum algorithm */
3173 		__u32 csum32;
3174 		__u16 dummy_csum = 0;
3175 
3176 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3177 				     sizeof(le_group));
3178 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3179 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3180 				     sizeof(dummy_csum));
3181 		offset += sizeof(dummy_csum);
3182 		if (offset < sbi->s_desc_size)
3183 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3184 					     sbi->s_desc_size - offset);
3185 
3186 		crc = csum32 & 0xFFFF;
3187 		goto out;
3188 	}
3189 
3190 	/* old crc16 code */
3191 	if (!ext4_has_feature_gdt_csum(sb))
3192 		return 0;
3193 
3194 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3195 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3196 	crc = crc16(crc, (__u8 *)gdp, offset);
3197 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3198 	/* for checksum of struct ext4_group_desc do the rest...*/
3199 	if (ext4_has_feature_64bit(sb) &&
3200 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3201 		crc = crc16(crc, (__u8 *)gdp + offset,
3202 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3203 				offset);
3204 
3205 out:
3206 	return cpu_to_le16(crc);
3207 }
3208 
3209 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3210 				struct ext4_group_desc *gdp)
3211 {
3212 	if (ext4_has_group_desc_csum(sb) &&
3213 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3214 		return 0;
3215 
3216 	return 1;
3217 }
3218 
3219 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3220 			      struct ext4_group_desc *gdp)
3221 {
3222 	if (!ext4_has_group_desc_csum(sb))
3223 		return;
3224 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3225 }
3226 
3227 /* Called at mount-time, super-block is locked */
3228 static int ext4_check_descriptors(struct super_block *sb,
3229 				  ext4_fsblk_t sb_block,
3230 				  ext4_group_t *first_not_zeroed)
3231 {
3232 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3233 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3234 	ext4_fsblk_t last_block;
3235 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3236 	ext4_fsblk_t block_bitmap;
3237 	ext4_fsblk_t inode_bitmap;
3238 	ext4_fsblk_t inode_table;
3239 	int flexbg_flag = 0;
3240 	ext4_group_t i, grp = sbi->s_groups_count;
3241 
3242 	if (ext4_has_feature_flex_bg(sb))
3243 		flexbg_flag = 1;
3244 
3245 	ext4_debug("Checking group descriptors");
3246 
3247 	for (i = 0; i < sbi->s_groups_count; i++) {
3248 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3249 
3250 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3251 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3252 		else
3253 			last_block = first_block +
3254 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3255 
3256 		if ((grp == sbi->s_groups_count) &&
3257 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3258 			grp = i;
3259 
3260 		block_bitmap = ext4_block_bitmap(sb, gdp);
3261 		if (block_bitmap == sb_block) {
3262 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3263 				 "Block bitmap for group %u overlaps "
3264 				 "superblock", i);
3265 			if (!sb_rdonly(sb))
3266 				return 0;
3267 		}
3268 		if (block_bitmap >= sb_block + 1 &&
3269 		    block_bitmap <= last_bg_block) {
3270 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3271 				 "Block bitmap for group %u overlaps "
3272 				 "block group descriptors", i);
3273 			if (!sb_rdonly(sb))
3274 				return 0;
3275 		}
3276 		if (block_bitmap < first_block || block_bitmap > last_block) {
3277 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3278 			       "Block bitmap for group %u not in group "
3279 			       "(block %llu)!", i, block_bitmap);
3280 			return 0;
3281 		}
3282 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3283 		if (inode_bitmap == sb_block) {
3284 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3285 				 "Inode bitmap for group %u overlaps "
3286 				 "superblock", i);
3287 			if (!sb_rdonly(sb))
3288 				return 0;
3289 		}
3290 		if (inode_bitmap >= sb_block + 1 &&
3291 		    inode_bitmap <= last_bg_block) {
3292 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3293 				 "Inode bitmap for group %u overlaps "
3294 				 "block group descriptors", i);
3295 			if (!sb_rdonly(sb))
3296 				return 0;
3297 		}
3298 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3299 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3300 			       "Inode bitmap for group %u not in group "
3301 			       "(block %llu)!", i, inode_bitmap);
3302 			return 0;
3303 		}
3304 		inode_table = ext4_inode_table(sb, gdp);
3305 		if (inode_table == sb_block) {
3306 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3307 				 "Inode table for group %u overlaps "
3308 				 "superblock", i);
3309 			if (!sb_rdonly(sb))
3310 				return 0;
3311 		}
3312 		if (inode_table >= sb_block + 1 &&
3313 		    inode_table <= last_bg_block) {
3314 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3315 				 "Inode table for group %u overlaps "
3316 				 "block group descriptors", i);
3317 			if (!sb_rdonly(sb))
3318 				return 0;
3319 		}
3320 		if (inode_table < first_block ||
3321 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3322 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3323 			       "Inode table for group %u not in group "
3324 			       "(block %llu)!", i, inode_table);
3325 			return 0;
3326 		}
3327 		ext4_lock_group(sb, i);
3328 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3329 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3330 				 "Checksum for group %u failed (%u!=%u)",
3331 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3332 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3333 			if (!sb_rdonly(sb)) {
3334 				ext4_unlock_group(sb, i);
3335 				return 0;
3336 			}
3337 		}
3338 		ext4_unlock_group(sb, i);
3339 		if (!flexbg_flag)
3340 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3341 	}
3342 	if (NULL != first_not_zeroed)
3343 		*first_not_zeroed = grp;
3344 	return 1;
3345 }
3346 
3347 /*
3348  * Maximal extent format file size.
3349  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3350  * extent format containers, within a sector_t, and within i_blocks
3351  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3352  * so that won't be a limiting factor.
3353  *
3354  * However there is other limiting factor. We do store extents in the form
3355  * of starting block and length, hence the resulting length of the extent
3356  * covering maximum file size must fit into on-disk format containers as
3357  * well. Given that length is always by 1 unit bigger than max unit (because
3358  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3359  *
3360  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3361  */
3362 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3363 {
3364 	loff_t res;
3365 	loff_t upper_limit = MAX_LFS_FILESIZE;
3366 
3367 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3368 
3369 	if (!has_huge_files) {
3370 		upper_limit = (1LL << 32) - 1;
3371 
3372 		/* total blocks in file system block size */
3373 		upper_limit >>= (blkbits - 9);
3374 		upper_limit <<= blkbits;
3375 	}
3376 
3377 	/*
3378 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3379 	 * by one fs block, so ee_len can cover the extent of maximum file
3380 	 * size
3381 	 */
3382 	res = (1LL << 32) - 1;
3383 	res <<= blkbits;
3384 
3385 	/* Sanity check against vm- & vfs- imposed limits */
3386 	if (res > upper_limit)
3387 		res = upper_limit;
3388 
3389 	return res;
3390 }
3391 
3392 /*
3393  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3394  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3395  * We need to be 1 filesystem block less than the 2^48 sector limit.
3396  */
3397 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3398 {
3399 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3400 	int meta_blocks;
3401 	unsigned int ppb = 1 << (bits - 2);
3402 
3403 	/*
3404 	 * This is calculated to be the largest file size for a dense, block
3405 	 * mapped file such that the file's total number of 512-byte sectors,
3406 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3407 	 *
3408 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3409 	 * number of 512-byte sectors of the file.
3410 	 */
3411 	if (!has_huge_files) {
3412 		/*
3413 		 * !has_huge_files or implies that the inode i_block field
3414 		 * represents total file blocks in 2^32 512-byte sectors ==
3415 		 * size of vfs inode i_blocks * 8
3416 		 */
3417 		upper_limit = (1LL << 32) - 1;
3418 
3419 		/* total blocks in file system block size */
3420 		upper_limit >>= (bits - 9);
3421 
3422 	} else {
3423 		/*
3424 		 * We use 48 bit ext4_inode i_blocks
3425 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3426 		 * represent total number of blocks in
3427 		 * file system block size
3428 		 */
3429 		upper_limit = (1LL << 48) - 1;
3430 
3431 	}
3432 
3433 	/* Compute how many blocks we can address by block tree */
3434 	res += ppb;
3435 	res += ppb * ppb;
3436 	res += ((loff_t)ppb) * ppb * ppb;
3437 	/* Compute how many metadata blocks are needed */
3438 	meta_blocks = 1;
3439 	meta_blocks += 1 + ppb;
3440 	meta_blocks += 1 + ppb + ppb * ppb;
3441 	/* Does block tree limit file size? */
3442 	if (res + meta_blocks <= upper_limit)
3443 		goto check_lfs;
3444 
3445 	res = upper_limit;
3446 	/* How many metadata blocks are needed for addressing upper_limit? */
3447 	upper_limit -= EXT4_NDIR_BLOCKS;
3448 	/* indirect blocks */
3449 	meta_blocks = 1;
3450 	upper_limit -= ppb;
3451 	/* double indirect blocks */
3452 	if (upper_limit < ppb * ppb) {
3453 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3454 		res -= meta_blocks;
3455 		goto check_lfs;
3456 	}
3457 	meta_blocks += 1 + ppb;
3458 	upper_limit -= ppb * ppb;
3459 	/* tripple indirect blocks for the rest */
3460 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3461 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3462 	res -= meta_blocks;
3463 check_lfs:
3464 	res <<= bits;
3465 	if (res > MAX_LFS_FILESIZE)
3466 		res = MAX_LFS_FILESIZE;
3467 
3468 	return res;
3469 }
3470 
3471 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3472 				   ext4_fsblk_t logical_sb_block, int nr)
3473 {
3474 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3475 	ext4_group_t bg, first_meta_bg;
3476 	int has_super = 0;
3477 
3478 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3479 
3480 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3481 		return logical_sb_block + nr + 1;
3482 	bg = sbi->s_desc_per_block * nr;
3483 	if (ext4_bg_has_super(sb, bg))
3484 		has_super = 1;
3485 
3486 	/*
3487 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3488 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3489 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3490 	 * compensate.
3491 	 */
3492 	if (sb->s_blocksize == 1024 && nr == 0 &&
3493 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3494 		has_super++;
3495 
3496 	return (has_super + ext4_group_first_block_no(sb, bg));
3497 }
3498 
3499 /**
3500  * ext4_get_stripe_size: Get the stripe size.
3501  * @sbi: In memory super block info
3502  *
3503  * If we have specified it via mount option, then
3504  * use the mount option value. If the value specified at mount time is
3505  * greater than the blocks per group use the super block value.
3506  * If the super block value is greater than blocks per group return 0.
3507  * Allocator needs it be less than blocks per group.
3508  *
3509  */
3510 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3511 {
3512 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3513 	unsigned long stripe_width =
3514 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3515 	int ret;
3516 
3517 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3518 		ret = sbi->s_stripe;
3519 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3520 		ret = stripe_width;
3521 	else if (stride && stride <= sbi->s_blocks_per_group)
3522 		ret = stride;
3523 	else
3524 		ret = 0;
3525 
3526 	/*
3527 	 * If the stripe width is 1, this makes no sense and
3528 	 * we set it to 0 to turn off stripe handling code.
3529 	 */
3530 	if (ret <= 1)
3531 		ret = 0;
3532 
3533 	return ret;
3534 }
3535 
3536 /*
3537  * Check whether this filesystem can be mounted based on
3538  * the features present and the RDONLY/RDWR mount requested.
3539  * Returns 1 if this filesystem can be mounted as requested,
3540  * 0 if it cannot be.
3541  */
3542 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3543 {
3544 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3545 		ext4_msg(sb, KERN_ERR,
3546 			"Couldn't mount because of "
3547 			"unsupported optional features (%x)",
3548 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3549 			~EXT4_FEATURE_INCOMPAT_SUPP));
3550 		return 0;
3551 	}
3552 
3553 #if !IS_ENABLED(CONFIG_UNICODE)
3554 	if (ext4_has_feature_casefold(sb)) {
3555 		ext4_msg(sb, KERN_ERR,
3556 			 "Filesystem with casefold feature cannot be "
3557 			 "mounted without CONFIG_UNICODE");
3558 		return 0;
3559 	}
3560 #endif
3561 
3562 	if (readonly)
3563 		return 1;
3564 
3565 	if (ext4_has_feature_readonly(sb)) {
3566 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3567 		sb->s_flags |= SB_RDONLY;
3568 		return 1;
3569 	}
3570 
3571 	/* Check that feature set is OK for a read-write mount */
3572 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3573 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3574 			 "unsupported optional features (%x)",
3575 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3576 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3577 		return 0;
3578 	}
3579 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3580 		ext4_msg(sb, KERN_ERR,
3581 			 "Can't support bigalloc feature without "
3582 			 "extents feature\n");
3583 		return 0;
3584 	}
3585 
3586 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3587 	if (!readonly && (ext4_has_feature_quota(sb) ||
3588 			  ext4_has_feature_project(sb))) {
3589 		ext4_msg(sb, KERN_ERR,
3590 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3591 		return 0;
3592 	}
3593 #endif  /* CONFIG_QUOTA */
3594 	return 1;
3595 }
3596 
3597 /*
3598  * This function is called once a day if we have errors logged
3599  * on the file system
3600  */
3601 static void print_daily_error_info(struct timer_list *t)
3602 {
3603 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3604 	struct super_block *sb = sbi->s_sb;
3605 	struct ext4_super_block *es = sbi->s_es;
3606 
3607 	if (es->s_error_count)
3608 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3609 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3610 			 le32_to_cpu(es->s_error_count));
3611 	if (es->s_first_error_time) {
3612 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3613 		       sb->s_id,
3614 		       ext4_get_tstamp(es, s_first_error_time),
3615 		       (int) sizeof(es->s_first_error_func),
3616 		       es->s_first_error_func,
3617 		       le32_to_cpu(es->s_first_error_line));
3618 		if (es->s_first_error_ino)
3619 			printk(KERN_CONT ": inode %u",
3620 			       le32_to_cpu(es->s_first_error_ino));
3621 		if (es->s_first_error_block)
3622 			printk(KERN_CONT ": block %llu", (unsigned long long)
3623 			       le64_to_cpu(es->s_first_error_block));
3624 		printk(KERN_CONT "\n");
3625 	}
3626 	if (es->s_last_error_time) {
3627 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3628 		       sb->s_id,
3629 		       ext4_get_tstamp(es, s_last_error_time),
3630 		       (int) sizeof(es->s_last_error_func),
3631 		       es->s_last_error_func,
3632 		       le32_to_cpu(es->s_last_error_line));
3633 		if (es->s_last_error_ino)
3634 			printk(KERN_CONT ": inode %u",
3635 			       le32_to_cpu(es->s_last_error_ino));
3636 		if (es->s_last_error_block)
3637 			printk(KERN_CONT ": block %llu", (unsigned long long)
3638 			       le64_to_cpu(es->s_last_error_block));
3639 		printk(KERN_CONT "\n");
3640 	}
3641 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3642 }
3643 
3644 /* Find next suitable group and run ext4_init_inode_table */
3645 static int ext4_run_li_request(struct ext4_li_request *elr)
3646 {
3647 	struct ext4_group_desc *gdp = NULL;
3648 	struct super_block *sb = elr->lr_super;
3649 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3650 	ext4_group_t group = elr->lr_next_group;
3651 	unsigned int prefetch_ios = 0;
3652 	int ret = 0;
3653 	u64 start_time;
3654 
3655 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3656 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3657 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3658 		if (prefetch_ios)
3659 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3660 					      prefetch_ios);
3661 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3662 					    prefetch_ios);
3663 		if (group >= elr->lr_next_group) {
3664 			ret = 1;
3665 			if (elr->lr_first_not_zeroed != ngroups &&
3666 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3667 				elr->lr_next_group = elr->lr_first_not_zeroed;
3668 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3669 				ret = 0;
3670 			}
3671 		}
3672 		return ret;
3673 	}
3674 
3675 	for (; group < ngroups; group++) {
3676 		gdp = ext4_get_group_desc(sb, group, NULL);
3677 		if (!gdp) {
3678 			ret = 1;
3679 			break;
3680 		}
3681 
3682 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3683 			break;
3684 	}
3685 
3686 	if (group >= ngroups)
3687 		ret = 1;
3688 
3689 	if (!ret) {
3690 		start_time = ktime_get_real_ns();
3691 		ret = ext4_init_inode_table(sb, group,
3692 					    elr->lr_timeout ? 0 : 1);
3693 		trace_ext4_lazy_itable_init(sb, group);
3694 		if (elr->lr_timeout == 0) {
3695 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3696 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3697 		}
3698 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3699 		elr->lr_next_group = group + 1;
3700 	}
3701 	return ret;
3702 }
3703 
3704 /*
3705  * Remove lr_request from the list_request and free the
3706  * request structure. Should be called with li_list_mtx held
3707  */
3708 static void ext4_remove_li_request(struct ext4_li_request *elr)
3709 {
3710 	if (!elr)
3711 		return;
3712 
3713 	list_del(&elr->lr_request);
3714 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3715 	kfree(elr);
3716 }
3717 
3718 static void ext4_unregister_li_request(struct super_block *sb)
3719 {
3720 	mutex_lock(&ext4_li_mtx);
3721 	if (!ext4_li_info) {
3722 		mutex_unlock(&ext4_li_mtx);
3723 		return;
3724 	}
3725 
3726 	mutex_lock(&ext4_li_info->li_list_mtx);
3727 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3728 	mutex_unlock(&ext4_li_info->li_list_mtx);
3729 	mutex_unlock(&ext4_li_mtx);
3730 }
3731 
3732 static struct task_struct *ext4_lazyinit_task;
3733 
3734 /*
3735  * This is the function where ext4lazyinit thread lives. It walks
3736  * through the request list searching for next scheduled filesystem.
3737  * When such a fs is found, run the lazy initialization request
3738  * (ext4_rn_li_request) and keep track of the time spend in this
3739  * function. Based on that time we compute next schedule time of
3740  * the request. When walking through the list is complete, compute
3741  * next waking time and put itself into sleep.
3742  */
3743 static int ext4_lazyinit_thread(void *arg)
3744 {
3745 	struct ext4_lazy_init *eli = arg;
3746 	struct list_head *pos, *n;
3747 	struct ext4_li_request *elr;
3748 	unsigned long next_wakeup, cur;
3749 
3750 	BUG_ON(NULL == eli);
3751 
3752 cont_thread:
3753 	while (true) {
3754 		next_wakeup = MAX_JIFFY_OFFSET;
3755 
3756 		mutex_lock(&eli->li_list_mtx);
3757 		if (list_empty(&eli->li_request_list)) {
3758 			mutex_unlock(&eli->li_list_mtx);
3759 			goto exit_thread;
3760 		}
3761 		list_for_each_safe(pos, n, &eli->li_request_list) {
3762 			int err = 0;
3763 			int progress = 0;
3764 			elr = list_entry(pos, struct ext4_li_request,
3765 					 lr_request);
3766 
3767 			if (time_before(jiffies, elr->lr_next_sched)) {
3768 				if (time_before(elr->lr_next_sched, next_wakeup))
3769 					next_wakeup = elr->lr_next_sched;
3770 				continue;
3771 			}
3772 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3773 				if (sb_start_write_trylock(elr->lr_super)) {
3774 					progress = 1;
3775 					/*
3776 					 * We hold sb->s_umount, sb can not
3777 					 * be removed from the list, it is
3778 					 * now safe to drop li_list_mtx
3779 					 */
3780 					mutex_unlock(&eli->li_list_mtx);
3781 					err = ext4_run_li_request(elr);
3782 					sb_end_write(elr->lr_super);
3783 					mutex_lock(&eli->li_list_mtx);
3784 					n = pos->next;
3785 				}
3786 				up_read((&elr->lr_super->s_umount));
3787 			}
3788 			/* error, remove the lazy_init job */
3789 			if (err) {
3790 				ext4_remove_li_request(elr);
3791 				continue;
3792 			}
3793 			if (!progress) {
3794 				elr->lr_next_sched = jiffies +
3795 					(prandom_u32()
3796 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3797 			}
3798 			if (time_before(elr->lr_next_sched, next_wakeup))
3799 				next_wakeup = elr->lr_next_sched;
3800 		}
3801 		mutex_unlock(&eli->li_list_mtx);
3802 
3803 		try_to_freeze();
3804 
3805 		cur = jiffies;
3806 		if ((time_after_eq(cur, next_wakeup)) ||
3807 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3808 			cond_resched();
3809 			continue;
3810 		}
3811 
3812 		schedule_timeout_interruptible(next_wakeup - cur);
3813 
3814 		if (kthread_should_stop()) {
3815 			ext4_clear_request_list();
3816 			goto exit_thread;
3817 		}
3818 	}
3819 
3820 exit_thread:
3821 	/*
3822 	 * It looks like the request list is empty, but we need
3823 	 * to check it under the li_list_mtx lock, to prevent any
3824 	 * additions into it, and of course we should lock ext4_li_mtx
3825 	 * to atomically free the list and ext4_li_info, because at
3826 	 * this point another ext4 filesystem could be registering
3827 	 * new one.
3828 	 */
3829 	mutex_lock(&ext4_li_mtx);
3830 	mutex_lock(&eli->li_list_mtx);
3831 	if (!list_empty(&eli->li_request_list)) {
3832 		mutex_unlock(&eli->li_list_mtx);
3833 		mutex_unlock(&ext4_li_mtx);
3834 		goto cont_thread;
3835 	}
3836 	mutex_unlock(&eli->li_list_mtx);
3837 	kfree(ext4_li_info);
3838 	ext4_li_info = NULL;
3839 	mutex_unlock(&ext4_li_mtx);
3840 
3841 	return 0;
3842 }
3843 
3844 static void ext4_clear_request_list(void)
3845 {
3846 	struct list_head *pos, *n;
3847 	struct ext4_li_request *elr;
3848 
3849 	mutex_lock(&ext4_li_info->li_list_mtx);
3850 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3851 		elr = list_entry(pos, struct ext4_li_request,
3852 				 lr_request);
3853 		ext4_remove_li_request(elr);
3854 	}
3855 	mutex_unlock(&ext4_li_info->li_list_mtx);
3856 }
3857 
3858 static int ext4_run_lazyinit_thread(void)
3859 {
3860 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3861 					 ext4_li_info, "ext4lazyinit");
3862 	if (IS_ERR(ext4_lazyinit_task)) {
3863 		int err = PTR_ERR(ext4_lazyinit_task);
3864 		ext4_clear_request_list();
3865 		kfree(ext4_li_info);
3866 		ext4_li_info = NULL;
3867 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3868 				 "initialization thread\n",
3869 				 err);
3870 		return err;
3871 	}
3872 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3873 	return 0;
3874 }
3875 
3876 /*
3877  * Check whether it make sense to run itable init. thread or not.
3878  * If there is at least one uninitialized inode table, return
3879  * corresponding group number, else the loop goes through all
3880  * groups and return total number of groups.
3881  */
3882 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3883 {
3884 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3885 	struct ext4_group_desc *gdp = NULL;
3886 
3887 	if (!ext4_has_group_desc_csum(sb))
3888 		return ngroups;
3889 
3890 	for (group = 0; group < ngroups; group++) {
3891 		gdp = ext4_get_group_desc(sb, group, NULL);
3892 		if (!gdp)
3893 			continue;
3894 
3895 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3896 			break;
3897 	}
3898 
3899 	return group;
3900 }
3901 
3902 static int ext4_li_info_new(void)
3903 {
3904 	struct ext4_lazy_init *eli = NULL;
3905 
3906 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3907 	if (!eli)
3908 		return -ENOMEM;
3909 
3910 	INIT_LIST_HEAD(&eli->li_request_list);
3911 	mutex_init(&eli->li_list_mtx);
3912 
3913 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3914 
3915 	ext4_li_info = eli;
3916 
3917 	return 0;
3918 }
3919 
3920 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3921 					    ext4_group_t start)
3922 {
3923 	struct ext4_li_request *elr;
3924 
3925 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3926 	if (!elr)
3927 		return NULL;
3928 
3929 	elr->lr_super = sb;
3930 	elr->lr_first_not_zeroed = start;
3931 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3932 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3933 		elr->lr_next_group = start;
3934 	} else {
3935 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3936 	}
3937 
3938 	/*
3939 	 * Randomize first schedule time of the request to
3940 	 * spread the inode table initialization requests
3941 	 * better.
3942 	 */
3943 	elr->lr_next_sched = jiffies + (prandom_u32() %
3944 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3945 	return elr;
3946 }
3947 
3948 int ext4_register_li_request(struct super_block *sb,
3949 			     ext4_group_t first_not_zeroed)
3950 {
3951 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3952 	struct ext4_li_request *elr = NULL;
3953 	ext4_group_t ngroups = sbi->s_groups_count;
3954 	int ret = 0;
3955 
3956 	mutex_lock(&ext4_li_mtx);
3957 	if (sbi->s_li_request != NULL) {
3958 		/*
3959 		 * Reset timeout so it can be computed again, because
3960 		 * s_li_wait_mult might have changed.
3961 		 */
3962 		sbi->s_li_request->lr_timeout = 0;
3963 		goto out;
3964 	}
3965 
3966 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3967 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3968 	     !test_opt(sb, INIT_INODE_TABLE)))
3969 		goto out;
3970 
3971 	elr = ext4_li_request_new(sb, first_not_zeroed);
3972 	if (!elr) {
3973 		ret = -ENOMEM;
3974 		goto out;
3975 	}
3976 
3977 	if (NULL == ext4_li_info) {
3978 		ret = ext4_li_info_new();
3979 		if (ret)
3980 			goto out;
3981 	}
3982 
3983 	mutex_lock(&ext4_li_info->li_list_mtx);
3984 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3985 	mutex_unlock(&ext4_li_info->li_list_mtx);
3986 
3987 	sbi->s_li_request = elr;
3988 	/*
3989 	 * set elr to NULL here since it has been inserted to
3990 	 * the request_list and the removal and free of it is
3991 	 * handled by ext4_clear_request_list from now on.
3992 	 */
3993 	elr = NULL;
3994 
3995 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3996 		ret = ext4_run_lazyinit_thread();
3997 		if (ret)
3998 			goto out;
3999 	}
4000 out:
4001 	mutex_unlock(&ext4_li_mtx);
4002 	if (ret)
4003 		kfree(elr);
4004 	return ret;
4005 }
4006 
4007 /*
4008  * We do not need to lock anything since this is called on
4009  * module unload.
4010  */
4011 static void ext4_destroy_lazyinit_thread(void)
4012 {
4013 	/*
4014 	 * If thread exited earlier
4015 	 * there's nothing to be done.
4016 	 */
4017 	if (!ext4_li_info || !ext4_lazyinit_task)
4018 		return;
4019 
4020 	kthread_stop(ext4_lazyinit_task);
4021 }
4022 
4023 static int set_journal_csum_feature_set(struct super_block *sb)
4024 {
4025 	int ret = 1;
4026 	int compat, incompat;
4027 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4028 
4029 	if (ext4_has_metadata_csum(sb)) {
4030 		/* journal checksum v3 */
4031 		compat = 0;
4032 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4033 	} else {
4034 		/* journal checksum v1 */
4035 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4036 		incompat = 0;
4037 	}
4038 
4039 	jbd2_journal_clear_features(sbi->s_journal,
4040 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4041 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4042 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4043 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4044 		ret = jbd2_journal_set_features(sbi->s_journal,
4045 				compat, 0,
4046 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4047 				incompat);
4048 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4049 		ret = jbd2_journal_set_features(sbi->s_journal,
4050 				compat, 0,
4051 				incompat);
4052 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4053 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4054 	} else {
4055 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4056 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4057 	}
4058 
4059 	return ret;
4060 }
4061 
4062 /*
4063  * Note: calculating the overhead so we can be compatible with
4064  * historical BSD practice is quite difficult in the face of
4065  * clusters/bigalloc.  This is because multiple metadata blocks from
4066  * different block group can end up in the same allocation cluster.
4067  * Calculating the exact overhead in the face of clustered allocation
4068  * requires either O(all block bitmaps) in memory or O(number of block
4069  * groups**2) in time.  We will still calculate the superblock for
4070  * older file systems --- and if we come across with a bigalloc file
4071  * system with zero in s_overhead_clusters the estimate will be close to
4072  * correct especially for very large cluster sizes --- but for newer
4073  * file systems, it's better to calculate this figure once at mkfs
4074  * time, and store it in the superblock.  If the superblock value is
4075  * present (even for non-bigalloc file systems), we will use it.
4076  */
4077 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4078 			  char *buf)
4079 {
4080 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4081 	struct ext4_group_desc	*gdp;
4082 	ext4_fsblk_t		first_block, last_block, b;
4083 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4084 	int			s, j, count = 0;
4085 	int			has_super = ext4_bg_has_super(sb, grp);
4086 
4087 	if (!ext4_has_feature_bigalloc(sb))
4088 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4089 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4090 			sbi->s_itb_per_group + 2);
4091 
4092 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4093 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4094 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4095 	for (i = 0; i < ngroups; i++) {
4096 		gdp = ext4_get_group_desc(sb, i, NULL);
4097 		b = ext4_block_bitmap(sb, gdp);
4098 		if (b >= first_block && b <= last_block) {
4099 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4100 			count++;
4101 		}
4102 		b = ext4_inode_bitmap(sb, gdp);
4103 		if (b >= first_block && b <= last_block) {
4104 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4105 			count++;
4106 		}
4107 		b = ext4_inode_table(sb, gdp);
4108 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4109 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4110 				int c = EXT4_B2C(sbi, b - first_block);
4111 				ext4_set_bit(c, buf);
4112 				count++;
4113 			}
4114 		if (i != grp)
4115 			continue;
4116 		s = 0;
4117 		if (ext4_bg_has_super(sb, grp)) {
4118 			ext4_set_bit(s++, buf);
4119 			count++;
4120 		}
4121 		j = ext4_bg_num_gdb(sb, grp);
4122 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4123 			ext4_error(sb, "Invalid number of block group "
4124 				   "descriptor blocks: %d", j);
4125 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4126 		}
4127 		count += j;
4128 		for (; j > 0; j--)
4129 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4130 	}
4131 	if (!count)
4132 		return 0;
4133 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4134 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4135 }
4136 
4137 /*
4138  * Compute the overhead and stash it in sbi->s_overhead
4139  */
4140 int ext4_calculate_overhead(struct super_block *sb)
4141 {
4142 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4143 	struct ext4_super_block *es = sbi->s_es;
4144 	struct inode *j_inode;
4145 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4146 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4147 	ext4_fsblk_t overhead = 0;
4148 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4149 
4150 	if (!buf)
4151 		return -ENOMEM;
4152 
4153 	/*
4154 	 * Compute the overhead (FS structures).  This is constant
4155 	 * for a given filesystem unless the number of block groups
4156 	 * changes so we cache the previous value until it does.
4157 	 */
4158 
4159 	/*
4160 	 * All of the blocks before first_data_block are overhead
4161 	 */
4162 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4163 
4164 	/*
4165 	 * Add the overhead found in each block group
4166 	 */
4167 	for (i = 0; i < ngroups; i++) {
4168 		int blks;
4169 
4170 		blks = count_overhead(sb, i, buf);
4171 		overhead += blks;
4172 		if (blks)
4173 			memset(buf, 0, PAGE_SIZE);
4174 		cond_resched();
4175 	}
4176 
4177 	/*
4178 	 * Add the internal journal blocks whether the journal has been
4179 	 * loaded or not
4180 	 */
4181 	if (sbi->s_journal && !sbi->s_journal_bdev)
4182 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4183 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4184 		/* j_inum for internal journal is non-zero */
4185 		j_inode = ext4_get_journal_inode(sb, j_inum);
4186 		if (j_inode) {
4187 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4188 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4189 			iput(j_inode);
4190 		} else {
4191 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4192 		}
4193 	}
4194 	sbi->s_overhead = overhead;
4195 	smp_wmb();
4196 	free_page((unsigned long) buf);
4197 	return 0;
4198 }
4199 
4200 static void ext4_set_resv_clusters(struct super_block *sb)
4201 {
4202 	ext4_fsblk_t resv_clusters;
4203 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4204 
4205 	/*
4206 	 * There's no need to reserve anything when we aren't using extents.
4207 	 * The space estimates are exact, there are no unwritten extents,
4208 	 * hole punching doesn't need new metadata... This is needed especially
4209 	 * to keep ext2/3 backward compatibility.
4210 	 */
4211 	if (!ext4_has_feature_extents(sb))
4212 		return;
4213 	/*
4214 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4215 	 * This should cover the situations where we can not afford to run
4216 	 * out of space like for example punch hole, or converting
4217 	 * unwritten extents in delalloc path. In most cases such
4218 	 * allocation would require 1, or 2 blocks, higher numbers are
4219 	 * very rare.
4220 	 */
4221 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4222 			 sbi->s_cluster_bits);
4223 
4224 	do_div(resv_clusters, 50);
4225 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4226 
4227 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4228 }
4229 
4230 static const char *ext4_quota_mode(struct super_block *sb)
4231 {
4232 #ifdef CONFIG_QUOTA
4233 	if (!ext4_quota_capable(sb))
4234 		return "none";
4235 
4236 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4237 		return "journalled";
4238 	else
4239 		return "writeback";
4240 #else
4241 	return "disabled";
4242 #endif
4243 }
4244 
4245 static void ext4_setup_csum_trigger(struct super_block *sb,
4246 				    enum ext4_journal_trigger_type type,
4247 				    void (*trigger)(
4248 					struct jbd2_buffer_trigger_type *type,
4249 					struct buffer_head *bh,
4250 					void *mapped_data,
4251 					size_t size))
4252 {
4253 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4254 
4255 	sbi->s_journal_triggers[type].sb = sb;
4256 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4257 }
4258 
4259 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4260 {
4261 	if (!sbi)
4262 		return;
4263 
4264 	kfree(sbi->s_blockgroup_lock);
4265 	fs_put_dax(sbi->s_daxdev);
4266 	kfree(sbi);
4267 }
4268 
4269 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4270 {
4271 	struct ext4_sb_info *sbi;
4272 
4273 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4274 	if (!sbi)
4275 		return NULL;
4276 
4277 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off);
4278 
4279 	sbi->s_blockgroup_lock =
4280 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4281 
4282 	if (!sbi->s_blockgroup_lock)
4283 		goto err_out;
4284 
4285 	sb->s_fs_info = sbi;
4286 	sbi->s_sb = sb;
4287 	return sbi;
4288 err_out:
4289 	fs_put_dax(sbi->s_daxdev);
4290 	kfree(sbi);
4291 	return NULL;
4292 }
4293 
4294 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
4295 {
4296 	struct buffer_head *bh, **group_desc;
4297 	struct ext4_super_block *es = NULL;
4298 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4299 	struct flex_groups **flex_groups;
4300 	ext4_fsblk_t block;
4301 	ext4_fsblk_t logical_sb_block;
4302 	unsigned long offset = 0;
4303 	unsigned long def_mount_opts;
4304 	struct inode *root;
4305 	int ret = -ENOMEM;
4306 	int blocksize, clustersize;
4307 	unsigned int db_count;
4308 	unsigned int i;
4309 	int needs_recovery, has_huge_files;
4310 	__u64 blocks_count;
4311 	int err = 0;
4312 	ext4_group_t first_not_zeroed;
4313 	struct ext4_fs_context *ctx = fc->fs_private;
4314 	int silent = fc->sb_flags & SB_SILENT;
4315 
4316 	/* Set defaults for the variables that will be set during parsing */
4317 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
4318 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4319 
4320 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4321 	sbi->s_sectors_written_start =
4322 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4323 
4324 	/* -EINVAL is default */
4325 	ret = -EINVAL;
4326 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4327 	if (!blocksize) {
4328 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4329 		goto out_fail;
4330 	}
4331 
4332 	/*
4333 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4334 	 * block sizes.  We need to calculate the offset from buffer start.
4335 	 */
4336 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4337 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4338 		offset = do_div(logical_sb_block, blocksize);
4339 	} else {
4340 		logical_sb_block = sbi->s_sb_block;
4341 	}
4342 
4343 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4344 	if (IS_ERR(bh)) {
4345 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4346 		ret = PTR_ERR(bh);
4347 		goto out_fail;
4348 	}
4349 	/*
4350 	 * Note: s_es must be initialized as soon as possible because
4351 	 *       some ext4 macro-instructions depend on its value
4352 	 */
4353 	es = (struct ext4_super_block *) (bh->b_data + offset);
4354 	sbi->s_es = es;
4355 	sb->s_magic = le16_to_cpu(es->s_magic);
4356 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4357 		goto cantfind_ext4;
4358 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4359 
4360 	/* Warn if metadata_csum and gdt_csum are both set. */
4361 	if (ext4_has_feature_metadata_csum(sb) &&
4362 	    ext4_has_feature_gdt_csum(sb))
4363 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4364 			     "redundant flags; please run fsck.");
4365 
4366 	/* Check for a known checksum algorithm */
4367 	if (!ext4_verify_csum_type(sb, es)) {
4368 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4369 			 "unknown checksum algorithm.");
4370 		silent = 1;
4371 		goto cantfind_ext4;
4372 	}
4373 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4374 				ext4_orphan_file_block_trigger);
4375 
4376 	/* Load the checksum driver */
4377 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4378 	if (IS_ERR(sbi->s_chksum_driver)) {
4379 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4380 		ret = PTR_ERR(sbi->s_chksum_driver);
4381 		sbi->s_chksum_driver = NULL;
4382 		goto failed_mount;
4383 	}
4384 
4385 	/* Check superblock checksum */
4386 	if (!ext4_superblock_csum_verify(sb, es)) {
4387 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4388 			 "invalid superblock checksum.  Run e2fsck?");
4389 		silent = 1;
4390 		ret = -EFSBADCRC;
4391 		goto cantfind_ext4;
4392 	}
4393 
4394 	/* Precompute checksum seed for all metadata */
4395 	if (ext4_has_feature_csum_seed(sb))
4396 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4397 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4398 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4399 					       sizeof(es->s_uuid));
4400 
4401 	/* Set defaults before we parse the mount options */
4402 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4403 	set_opt(sb, INIT_INODE_TABLE);
4404 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4405 		set_opt(sb, DEBUG);
4406 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4407 		set_opt(sb, GRPID);
4408 	if (def_mount_opts & EXT4_DEFM_UID16)
4409 		set_opt(sb, NO_UID32);
4410 	/* xattr user namespace & acls are now defaulted on */
4411 	set_opt(sb, XATTR_USER);
4412 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4413 	set_opt(sb, POSIX_ACL);
4414 #endif
4415 	if (ext4_has_feature_fast_commit(sb))
4416 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4417 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4418 	if (ext4_has_metadata_csum(sb))
4419 		set_opt(sb, JOURNAL_CHECKSUM);
4420 
4421 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4422 		set_opt(sb, JOURNAL_DATA);
4423 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4424 		set_opt(sb, ORDERED_DATA);
4425 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4426 		set_opt(sb, WRITEBACK_DATA);
4427 
4428 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4429 		set_opt(sb, ERRORS_PANIC);
4430 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4431 		set_opt(sb, ERRORS_CONT);
4432 	else
4433 		set_opt(sb, ERRORS_RO);
4434 	/* block_validity enabled by default; disable with noblock_validity */
4435 	set_opt(sb, BLOCK_VALIDITY);
4436 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4437 		set_opt(sb, DISCARD);
4438 
4439 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4440 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4441 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4442 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4443 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4444 
4445 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4446 		set_opt(sb, BARRIER);
4447 
4448 	/*
4449 	 * enable delayed allocation by default
4450 	 * Use -o nodelalloc to turn it off
4451 	 */
4452 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4453 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4454 		set_opt(sb, DELALLOC);
4455 
4456 	/*
4457 	 * set default s_li_wait_mult for lazyinit, for the case there is
4458 	 * no mount option specified.
4459 	 */
4460 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4461 
4462 	if (le32_to_cpu(es->s_log_block_size) >
4463 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4464 		ext4_msg(sb, KERN_ERR,
4465 			 "Invalid log block size: %u",
4466 			 le32_to_cpu(es->s_log_block_size));
4467 		goto failed_mount;
4468 	}
4469 	if (le32_to_cpu(es->s_log_cluster_size) >
4470 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4471 		ext4_msg(sb, KERN_ERR,
4472 			 "Invalid log cluster size: %u",
4473 			 le32_to_cpu(es->s_log_cluster_size));
4474 		goto failed_mount;
4475 	}
4476 
4477 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4478 
4479 	if (blocksize == PAGE_SIZE)
4480 		set_opt(sb, DIOREAD_NOLOCK);
4481 
4482 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4483 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4484 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4485 	} else {
4486 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4487 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4488 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4489 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4490 				 sbi->s_first_ino);
4491 			goto failed_mount;
4492 		}
4493 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4494 		    (!is_power_of_2(sbi->s_inode_size)) ||
4495 		    (sbi->s_inode_size > blocksize)) {
4496 			ext4_msg(sb, KERN_ERR,
4497 			       "unsupported inode size: %d",
4498 			       sbi->s_inode_size);
4499 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4500 			goto failed_mount;
4501 		}
4502 		/*
4503 		 * i_atime_extra is the last extra field available for
4504 		 * [acm]times in struct ext4_inode. Checking for that
4505 		 * field should suffice to ensure we have extra space
4506 		 * for all three.
4507 		 */
4508 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4509 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4510 			sb->s_time_gran = 1;
4511 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4512 		} else {
4513 			sb->s_time_gran = NSEC_PER_SEC;
4514 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4515 		}
4516 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4517 	}
4518 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4519 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4520 			EXT4_GOOD_OLD_INODE_SIZE;
4521 		if (ext4_has_feature_extra_isize(sb)) {
4522 			unsigned v, max = (sbi->s_inode_size -
4523 					   EXT4_GOOD_OLD_INODE_SIZE);
4524 
4525 			v = le16_to_cpu(es->s_want_extra_isize);
4526 			if (v > max) {
4527 				ext4_msg(sb, KERN_ERR,
4528 					 "bad s_want_extra_isize: %d", v);
4529 				goto failed_mount;
4530 			}
4531 			if (sbi->s_want_extra_isize < v)
4532 				sbi->s_want_extra_isize = v;
4533 
4534 			v = le16_to_cpu(es->s_min_extra_isize);
4535 			if (v > max) {
4536 				ext4_msg(sb, KERN_ERR,
4537 					 "bad s_min_extra_isize: %d", v);
4538 				goto failed_mount;
4539 			}
4540 			if (sbi->s_want_extra_isize < v)
4541 				sbi->s_want_extra_isize = v;
4542 		}
4543 	}
4544 
4545 	err = parse_apply_sb_mount_options(sb, ctx);
4546 	if (err < 0)
4547 		goto failed_mount;
4548 
4549 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4550 
4551 	err = ext4_check_opt_consistency(fc, sb);
4552 	if (err < 0)
4553 		goto failed_mount;
4554 
4555 	err = ext4_apply_options(fc, sb);
4556 	if (err < 0)
4557 		goto failed_mount;
4558 
4559 #if IS_ENABLED(CONFIG_UNICODE)
4560 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4561 		const struct ext4_sb_encodings *encoding_info;
4562 		struct unicode_map *encoding;
4563 		__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4564 
4565 		encoding_info = ext4_sb_read_encoding(es);
4566 		if (!encoding_info) {
4567 			ext4_msg(sb, KERN_ERR,
4568 				 "Encoding requested by superblock is unknown");
4569 			goto failed_mount;
4570 		}
4571 
4572 		encoding = utf8_load(encoding_info->version);
4573 		if (IS_ERR(encoding)) {
4574 			ext4_msg(sb, KERN_ERR,
4575 				 "can't mount with superblock charset: %s-%u.%u.%u "
4576 				 "not supported by the kernel. flags: 0x%x.",
4577 				 encoding_info->name,
4578 				 unicode_major(encoding_info->version),
4579 				 unicode_minor(encoding_info->version),
4580 				 unicode_rev(encoding_info->version),
4581 				 encoding_flags);
4582 			goto failed_mount;
4583 		}
4584 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4585 			 "%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4586 			 unicode_major(encoding_info->version),
4587 			 unicode_minor(encoding_info->version),
4588 			 unicode_rev(encoding_info->version),
4589 			 encoding_flags);
4590 
4591 		sb->s_encoding = encoding;
4592 		sb->s_encoding_flags = encoding_flags;
4593 	}
4594 #endif
4595 
4596 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4597 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4598 		/* can't mount with both data=journal and dioread_nolock. */
4599 		clear_opt(sb, DIOREAD_NOLOCK);
4600 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4601 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4602 			ext4_msg(sb, KERN_ERR, "can't mount with "
4603 				 "both data=journal and delalloc");
4604 			goto failed_mount;
4605 		}
4606 		if (test_opt(sb, DAX_ALWAYS)) {
4607 			ext4_msg(sb, KERN_ERR, "can't mount with "
4608 				 "both data=journal and dax");
4609 			goto failed_mount;
4610 		}
4611 		if (ext4_has_feature_encrypt(sb)) {
4612 			ext4_msg(sb, KERN_WARNING,
4613 				 "encrypted files will use data=ordered "
4614 				 "instead of data journaling mode");
4615 		}
4616 		if (test_opt(sb, DELALLOC))
4617 			clear_opt(sb, DELALLOC);
4618 	} else {
4619 		sb->s_iflags |= SB_I_CGROUPWB;
4620 	}
4621 
4622 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4623 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4624 
4625 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4626 	    (ext4_has_compat_features(sb) ||
4627 	     ext4_has_ro_compat_features(sb) ||
4628 	     ext4_has_incompat_features(sb)))
4629 		ext4_msg(sb, KERN_WARNING,
4630 		       "feature flags set on rev 0 fs, "
4631 		       "running e2fsck is recommended");
4632 
4633 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4634 		set_opt2(sb, HURD_COMPAT);
4635 		if (ext4_has_feature_64bit(sb)) {
4636 			ext4_msg(sb, KERN_ERR,
4637 				 "The Hurd can't support 64-bit file systems");
4638 			goto failed_mount;
4639 		}
4640 
4641 		/*
4642 		 * ea_inode feature uses l_i_version field which is not
4643 		 * available in HURD_COMPAT mode.
4644 		 */
4645 		if (ext4_has_feature_ea_inode(sb)) {
4646 			ext4_msg(sb, KERN_ERR,
4647 				 "ea_inode feature is not supported for Hurd");
4648 			goto failed_mount;
4649 		}
4650 	}
4651 
4652 	if (IS_EXT2_SB(sb)) {
4653 		if (ext2_feature_set_ok(sb))
4654 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4655 				 "using the ext4 subsystem");
4656 		else {
4657 			/*
4658 			 * If we're probing be silent, if this looks like
4659 			 * it's actually an ext[34] filesystem.
4660 			 */
4661 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4662 				goto failed_mount;
4663 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4664 				 "to feature incompatibilities");
4665 			goto failed_mount;
4666 		}
4667 	}
4668 
4669 	if (IS_EXT3_SB(sb)) {
4670 		if (ext3_feature_set_ok(sb))
4671 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4672 				 "using the ext4 subsystem");
4673 		else {
4674 			/*
4675 			 * If we're probing be silent, if this looks like
4676 			 * it's actually an ext4 filesystem.
4677 			 */
4678 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4679 				goto failed_mount;
4680 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4681 				 "to feature incompatibilities");
4682 			goto failed_mount;
4683 		}
4684 	}
4685 
4686 	/*
4687 	 * Check feature flags regardless of the revision level, since we
4688 	 * previously didn't change the revision level when setting the flags,
4689 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4690 	 */
4691 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4692 		goto failed_mount;
4693 
4694 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4695 		ext4_msg(sb, KERN_ERR,
4696 			 "Number of reserved GDT blocks insanely large: %d",
4697 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4698 		goto failed_mount;
4699 	}
4700 
4701 	if (sbi->s_daxdev) {
4702 		if (blocksize == PAGE_SIZE)
4703 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4704 		else
4705 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4706 	}
4707 
4708 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4709 		if (ext4_has_feature_inline_data(sb)) {
4710 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4711 					" that may contain inline data");
4712 			goto failed_mount;
4713 		}
4714 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4715 			ext4_msg(sb, KERN_ERR,
4716 				"DAX unsupported by block device.");
4717 			goto failed_mount;
4718 		}
4719 	}
4720 
4721 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4722 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4723 			 es->s_encryption_level);
4724 		goto failed_mount;
4725 	}
4726 
4727 	if (sb->s_blocksize != blocksize) {
4728 		/*
4729 		 * bh must be released before kill_bdev(), otherwise
4730 		 * it won't be freed and its page also. kill_bdev()
4731 		 * is called by sb_set_blocksize().
4732 		 */
4733 		brelse(bh);
4734 		/* Validate the filesystem blocksize */
4735 		if (!sb_set_blocksize(sb, blocksize)) {
4736 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4737 					blocksize);
4738 			bh = NULL;
4739 			goto failed_mount;
4740 		}
4741 
4742 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4743 		offset = do_div(logical_sb_block, blocksize);
4744 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4745 		if (IS_ERR(bh)) {
4746 			ext4_msg(sb, KERN_ERR,
4747 			       "Can't read superblock on 2nd try");
4748 			ret = PTR_ERR(bh);
4749 			bh = NULL;
4750 			goto failed_mount;
4751 		}
4752 		es = (struct ext4_super_block *)(bh->b_data + offset);
4753 		sbi->s_es = es;
4754 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4755 			ext4_msg(sb, KERN_ERR,
4756 			       "Magic mismatch, very weird!");
4757 			goto failed_mount;
4758 		}
4759 	}
4760 
4761 	has_huge_files = ext4_has_feature_huge_file(sb);
4762 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4763 						      has_huge_files);
4764 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4765 
4766 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4767 	if (ext4_has_feature_64bit(sb)) {
4768 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4769 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4770 		    !is_power_of_2(sbi->s_desc_size)) {
4771 			ext4_msg(sb, KERN_ERR,
4772 			       "unsupported descriptor size %lu",
4773 			       sbi->s_desc_size);
4774 			goto failed_mount;
4775 		}
4776 	} else
4777 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4778 
4779 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4780 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4781 
4782 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4783 	if (sbi->s_inodes_per_block == 0)
4784 		goto cantfind_ext4;
4785 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4786 	    sbi->s_inodes_per_group > blocksize * 8) {
4787 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4788 			 sbi->s_inodes_per_group);
4789 		goto failed_mount;
4790 	}
4791 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4792 					sbi->s_inodes_per_block;
4793 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4794 	sbi->s_sbh = bh;
4795 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
4796 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4797 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4798 
4799 	for (i = 0; i < 4; i++)
4800 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4801 	sbi->s_def_hash_version = es->s_def_hash_version;
4802 	if (ext4_has_feature_dir_index(sb)) {
4803 		i = le32_to_cpu(es->s_flags);
4804 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4805 			sbi->s_hash_unsigned = 3;
4806 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4807 #ifdef __CHAR_UNSIGNED__
4808 			if (!sb_rdonly(sb))
4809 				es->s_flags |=
4810 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4811 			sbi->s_hash_unsigned = 3;
4812 #else
4813 			if (!sb_rdonly(sb))
4814 				es->s_flags |=
4815 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4816 #endif
4817 		}
4818 	}
4819 
4820 	/* Handle clustersize */
4821 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4822 	if (ext4_has_feature_bigalloc(sb)) {
4823 		if (clustersize < blocksize) {
4824 			ext4_msg(sb, KERN_ERR,
4825 				 "cluster size (%d) smaller than "
4826 				 "block size (%d)", clustersize, blocksize);
4827 			goto failed_mount;
4828 		}
4829 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4830 			le32_to_cpu(es->s_log_block_size);
4831 		sbi->s_clusters_per_group =
4832 			le32_to_cpu(es->s_clusters_per_group);
4833 		if (sbi->s_clusters_per_group > blocksize * 8) {
4834 			ext4_msg(sb, KERN_ERR,
4835 				 "#clusters per group too big: %lu",
4836 				 sbi->s_clusters_per_group);
4837 			goto failed_mount;
4838 		}
4839 		if (sbi->s_blocks_per_group !=
4840 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4841 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4842 				 "clusters per group (%lu) inconsistent",
4843 				 sbi->s_blocks_per_group,
4844 				 sbi->s_clusters_per_group);
4845 			goto failed_mount;
4846 		}
4847 	} else {
4848 		if (clustersize != blocksize) {
4849 			ext4_msg(sb, KERN_ERR,
4850 				 "fragment/cluster size (%d) != "
4851 				 "block size (%d)", clustersize, blocksize);
4852 			goto failed_mount;
4853 		}
4854 		if (sbi->s_blocks_per_group > blocksize * 8) {
4855 			ext4_msg(sb, KERN_ERR,
4856 				 "#blocks per group too big: %lu",
4857 				 sbi->s_blocks_per_group);
4858 			goto failed_mount;
4859 		}
4860 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4861 		sbi->s_cluster_bits = 0;
4862 	}
4863 	sbi->s_cluster_ratio = clustersize / blocksize;
4864 
4865 	/* Do we have standard group size of clustersize * 8 blocks ? */
4866 	if (sbi->s_blocks_per_group == clustersize << 3)
4867 		set_opt2(sb, STD_GROUP_SIZE);
4868 
4869 	/*
4870 	 * Test whether we have more sectors than will fit in sector_t,
4871 	 * and whether the max offset is addressable by the page cache.
4872 	 */
4873 	err = generic_check_addressable(sb->s_blocksize_bits,
4874 					ext4_blocks_count(es));
4875 	if (err) {
4876 		ext4_msg(sb, KERN_ERR, "filesystem"
4877 			 " too large to mount safely on this system");
4878 		goto failed_mount;
4879 	}
4880 
4881 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4882 		goto cantfind_ext4;
4883 
4884 	/* check blocks count against device size */
4885 	blocks_count = sb_bdev_nr_blocks(sb);
4886 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4887 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4888 		       "exceeds size of device (%llu blocks)",
4889 		       ext4_blocks_count(es), blocks_count);
4890 		goto failed_mount;
4891 	}
4892 
4893 	/*
4894 	 * It makes no sense for the first data block to be beyond the end
4895 	 * of the filesystem.
4896 	 */
4897 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4898 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4899 			 "block %u is beyond end of filesystem (%llu)",
4900 			 le32_to_cpu(es->s_first_data_block),
4901 			 ext4_blocks_count(es));
4902 		goto failed_mount;
4903 	}
4904 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4905 	    (sbi->s_cluster_ratio == 1)) {
4906 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4907 			 "block is 0 with a 1k block and cluster size");
4908 		goto failed_mount;
4909 	}
4910 
4911 	blocks_count = (ext4_blocks_count(es) -
4912 			le32_to_cpu(es->s_first_data_block) +
4913 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4914 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4915 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4916 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4917 		       "(block count %llu, first data block %u, "
4918 		       "blocks per group %lu)", blocks_count,
4919 		       ext4_blocks_count(es),
4920 		       le32_to_cpu(es->s_first_data_block),
4921 		       EXT4_BLOCKS_PER_GROUP(sb));
4922 		goto failed_mount;
4923 	}
4924 	sbi->s_groups_count = blocks_count;
4925 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4926 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4927 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4928 	    le32_to_cpu(es->s_inodes_count)) {
4929 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4930 			 le32_to_cpu(es->s_inodes_count),
4931 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4932 		ret = -EINVAL;
4933 		goto failed_mount;
4934 	}
4935 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4936 		   EXT4_DESC_PER_BLOCK(sb);
4937 	if (ext4_has_feature_meta_bg(sb)) {
4938 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4939 			ext4_msg(sb, KERN_WARNING,
4940 				 "first meta block group too large: %u "
4941 				 "(group descriptor block count %u)",
4942 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4943 			goto failed_mount;
4944 		}
4945 	}
4946 	rcu_assign_pointer(sbi->s_group_desc,
4947 			   kvmalloc_array(db_count,
4948 					  sizeof(struct buffer_head *),
4949 					  GFP_KERNEL));
4950 	if (sbi->s_group_desc == NULL) {
4951 		ext4_msg(sb, KERN_ERR, "not enough memory");
4952 		ret = -ENOMEM;
4953 		goto failed_mount;
4954 	}
4955 
4956 	bgl_lock_init(sbi->s_blockgroup_lock);
4957 
4958 	/* Pre-read the descriptors into the buffer cache */
4959 	for (i = 0; i < db_count; i++) {
4960 		block = descriptor_loc(sb, logical_sb_block, i);
4961 		ext4_sb_breadahead_unmovable(sb, block);
4962 	}
4963 
4964 	for (i = 0; i < db_count; i++) {
4965 		struct buffer_head *bh;
4966 
4967 		block = descriptor_loc(sb, logical_sb_block, i);
4968 		bh = ext4_sb_bread_unmovable(sb, block);
4969 		if (IS_ERR(bh)) {
4970 			ext4_msg(sb, KERN_ERR,
4971 			       "can't read group descriptor %d", i);
4972 			db_count = i;
4973 			ret = PTR_ERR(bh);
4974 			goto failed_mount2;
4975 		}
4976 		rcu_read_lock();
4977 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4978 		rcu_read_unlock();
4979 	}
4980 	sbi->s_gdb_count = db_count;
4981 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4982 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4983 		ret = -EFSCORRUPTED;
4984 		goto failed_mount2;
4985 	}
4986 
4987 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4988 	spin_lock_init(&sbi->s_error_lock);
4989 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
4990 
4991 	/* Register extent status tree shrinker */
4992 	if (ext4_es_register_shrinker(sbi))
4993 		goto failed_mount3;
4994 
4995 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4996 	sbi->s_extent_max_zeroout_kb = 32;
4997 
4998 	/*
4999 	 * set up enough so that it can read an inode
5000 	 */
5001 	sb->s_op = &ext4_sops;
5002 	sb->s_export_op = &ext4_export_ops;
5003 	sb->s_xattr = ext4_xattr_handlers;
5004 #ifdef CONFIG_FS_ENCRYPTION
5005 	sb->s_cop = &ext4_cryptops;
5006 #endif
5007 #ifdef CONFIG_FS_VERITY
5008 	sb->s_vop = &ext4_verityops;
5009 #endif
5010 #ifdef CONFIG_QUOTA
5011 	sb->dq_op = &ext4_quota_operations;
5012 	if (ext4_has_feature_quota(sb))
5013 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5014 	else
5015 		sb->s_qcop = &ext4_qctl_operations;
5016 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5017 #endif
5018 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5019 
5020 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5021 	mutex_init(&sbi->s_orphan_lock);
5022 
5023 	/* Initialize fast commit stuff */
5024 	atomic_set(&sbi->s_fc_subtid, 0);
5025 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
5026 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
5027 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
5028 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
5029 	sbi->s_fc_bytes = 0;
5030 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
5031 	sbi->s_fc_ineligible_tid = 0;
5032 	spin_lock_init(&sbi->s_fc_lock);
5033 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
5034 	sbi->s_fc_replay_state.fc_regions = NULL;
5035 	sbi->s_fc_replay_state.fc_regions_size = 0;
5036 	sbi->s_fc_replay_state.fc_regions_used = 0;
5037 	sbi->s_fc_replay_state.fc_regions_valid = 0;
5038 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
5039 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
5040 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
5041 
5042 	sb->s_root = NULL;
5043 
5044 	needs_recovery = (es->s_last_orphan != 0 ||
5045 			  ext4_has_feature_orphan_present(sb) ||
5046 			  ext4_has_feature_journal_needs_recovery(sb));
5047 
5048 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5049 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5050 			goto failed_mount3a;
5051 
5052 	/*
5053 	 * The first inode we look at is the journal inode.  Don't try
5054 	 * root first: it may be modified in the journal!
5055 	 */
5056 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5057 		err = ext4_load_journal(sb, es, ctx->journal_devnum);
5058 		if (err)
5059 			goto failed_mount3a;
5060 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5061 		   ext4_has_feature_journal_needs_recovery(sb)) {
5062 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5063 		       "suppressed and not mounted read-only");
5064 		goto failed_mount_wq;
5065 	} else {
5066 		/* Nojournal mode, all journal mount options are illegal */
5067 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5068 			ext4_msg(sb, KERN_ERR, "can't mount with "
5069 				 "journal_checksum, fs mounted w/o journal");
5070 			goto failed_mount_wq;
5071 		}
5072 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5073 			ext4_msg(sb, KERN_ERR, "can't mount with "
5074 				 "journal_async_commit, fs mounted w/o journal");
5075 			goto failed_mount_wq;
5076 		}
5077 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5078 			ext4_msg(sb, KERN_ERR, "can't mount with "
5079 				 "commit=%lu, fs mounted w/o journal",
5080 				 sbi->s_commit_interval / HZ);
5081 			goto failed_mount_wq;
5082 		}
5083 		if (EXT4_MOUNT_DATA_FLAGS &
5084 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5085 			ext4_msg(sb, KERN_ERR, "can't mount with "
5086 				 "data=, fs mounted w/o journal");
5087 			goto failed_mount_wq;
5088 		}
5089 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5090 		clear_opt(sb, JOURNAL_CHECKSUM);
5091 		clear_opt(sb, DATA_FLAGS);
5092 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5093 		sbi->s_journal = NULL;
5094 		needs_recovery = 0;
5095 		goto no_journal;
5096 	}
5097 
5098 	if (ext4_has_feature_64bit(sb) &&
5099 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5100 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
5101 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
5102 		goto failed_mount_wq;
5103 	}
5104 
5105 	if (!set_journal_csum_feature_set(sb)) {
5106 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
5107 			 "feature set");
5108 		goto failed_mount_wq;
5109 	}
5110 
5111 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
5112 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5113 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
5114 		ext4_msg(sb, KERN_ERR,
5115 			"Failed to set fast commit journal feature");
5116 		goto failed_mount_wq;
5117 	}
5118 
5119 	/* We have now updated the journal if required, so we can
5120 	 * validate the data journaling mode. */
5121 	switch (test_opt(sb, DATA_FLAGS)) {
5122 	case 0:
5123 		/* No mode set, assume a default based on the journal
5124 		 * capabilities: ORDERED_DATA if the journal can
5125 		 * cope, else JOURNAL_DATA
5126 		 */
5127 		if (jbd2_journal_check_available_features
5128 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5129 			set_opt(sb, ORDERED_DATA);
5130 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
5131 		} else {
5132 			set_opt(sb, JOURNAL_DATA);
5133 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
5134 		}
5135 		break;
5136 
5137 	case EXT4_MOUNT_ORDERED_DATA:
5138 	case EXT4_MOUNT_WRITEBACK_DATA:
5139 		if (!jbd2_journal_check_available_features
5140 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5141 			ext4_msg(sb, KERN_ERR, "Journal does not support "
5142 			       "requested data journaling mode");
5143 			goto failed_mount_wq;
5144 		}
5145 		break;
5146 	default:
5147 		break;
5148 	}
5149 
5150 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5151 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5152 		ext4_msg(sb, KERN_ERR, "can't mount with "
5153 			"journal_async_commit in data=ordered mode");
5154 		goto failed_mount_wq;
5155 	}
5156 
5157 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5158 
5159 	sbi->s_journal->j_submit_inode_data_buffers =
5160 		ext4_journal_submit_inode_data_buffers;
5161 	sbi->s_journal->j_finish_inode_data_buffers =
5162 		ext4_journal_finish_inode_data_buffers;
5163 
5164 no_journal:
5165 	if (!test_opt(sb, NO_MBCACHE)) {
5166 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5167 		if (!sbi->s_ea_block_cache) {
5168 			ext4_msg(sb, KERN_ERR,
5169 				 "Failed to create ea_block_cache");
5170 			goto failed_mount_wq;
5171 		}
5172 
5173 		if (ext4_has_feature_ea_inode(sb)) {
5174 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5175 			if (!sbi->s_ea_inode_cache) {
5176 				ext4_msg(sb, KERN_ERR,
5177 					 "Failed to create ea_inode_cache");
5178 				goto failed_mount_wq;
5179 			}
5180 		}
5181 	}
5182 
5183 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
5184 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5185 		goto failed_mount_wq;
5186 	}
5187 
5188 	/*
5189 	 * Get the # of file system overhead blocks from the
5190 	 * superblock if present.
5191 	 */
5192 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5193 	/* ignore the precalculated value if it is ridiculous */
5194 	if (sbi->s_overhead > ext4_blocks_count(es))
5195 		sbi->s_overhead = 0;
5196 	/*
5197 	 * If the bigalloc feature is not enabled recalculating the
5198 	 * overhead doesn't take long, so we might as well just redo
5199 	 * it to make sure we are using the correct value.
5200 	 */
5201 	if (!ext4_has_feature_bigalloc(sb))
5202 		sbi->s_overhead = 0;
5203 	if (sbi->s_overhead == 0) {
5204 		err = ext4_calculate_overhead(sb);
5205 		if (err)
5206 			goto failed_mount_wq;
5207 	}
5208 
5209 	/*
5210 	 * The maximum number of concurrent works can be high and
5211 	 * concurrency isn't really necessary.  Limit it to 1.
5212 	 */
5213 	EXT4_SB(sb)->rsv_conversion_wq =
5214 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5215 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5216 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5217 		ret = -ENOMEM;
5218 		goto failed_mount4;
5219 	}
5220 
5221 	/*
5222 	 * The jbd2_journal_load will have done any necessary log recovery,
5223 	 * so we can safely mount the rest of the filesystem now.
5224 	 */
5225 
5226 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5227 	if (IS_ERR(root)) {
5228 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5229 		ret = PTR_ERR(root);
5230 		root = NULL;
5231 		goto failed_mount4;
5232 	}
5233 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5234 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5235 		iput(root);
5236 		goto failed_mount4;
5237 	}
5238 
5239 	sb->s_root = d_make_root(root);
5240 	if (!sb->s_root) {
5241 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5242 		ret = -ENOMEM;
5243 		goto failed_mount4;
5244 	}
5245 
5246 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5247 	if (ret == -EROFS) {
5248 		sb->s_flags |= SB_RDONLY;
5249 		ret = 0;
5250 	} else if (ret)
5251 		goto failed_mount4a;
5252 
5253 	ext4_set_resv_clusters(sb);
5254 
5255 	if (test_opt(sb, BLOCK_VALIDITY)) {
5256 		err = ext4_setup_system_zone(sb);
5257 		if (err) {
5258 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5259 				 "zone (%d)", err);
5260 			goto failed_mount4a;
5261 		}
5262 	}
5263 	ext4_fc_replay_cleanup(sb);
5264 
5265 	ext4_ext_init(sb);
5266 
5267 	/*
5268 	 * Enable optimize_scan if number of groups is > threshold. This can be
5269 	 * turned off by passing "mb_optimize_scan=0". This can also be
5270 	 * turned on forcefully by passing "mb_optimize_scan=1".
5271 	 */
5272 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5273 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5274 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5275 		else
5276 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5277 	}
5278 
5279 	err = ext4_mb_init(sb);
5280 	if (err) {
5281 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5282 			 err);
5283 		goto failed_mount5;
5284 	}
5285 
5286 	/*
5287 	 * We can only set up the journal commit callback once
5288 	 * mballoc is initialized
5289 	 */
5290 	if (sbi->s_journal)
5291 		sbi->s_journal->j_commit_callback =
5292 			ext4_journal_commit_callback;
5293 
5294 	block = ext4_count_free_clusters(sb);
5295 	ext4_free_blocks_count_set(sbi->s_es,
5296 				   EXT4_C2B(sbi, block));
5297 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5298 				  GFP_KERNEL);
5299 	if (!err) {
5300 		unsigned long freei = ext4_count_free_inodes(sb);
5301 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5302 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5303 					  GFP_KERNEL);
5304 	}
5305 	/*
5306 	 * Update the checksum after updating free space/inode
5307 	 * counters.  Otherwise the superblock can have an incorrect
5308 	 * checksum in the buffer cache until it is written out and
5309 	 * e2fsprogs programs trying to open a file system immediately
5310 	 * after it is mounted can fail.
5311 	 */
5312 	ext4_superblock_csum_set(sb);
5313 	if (!err)
5314 		err = percpu_counter_init(&sbi->s_dirs_counter,
5315 					  ext4_count_dirs(sb), GFP_KERNEL);
5316 	if (!err)
5317 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5318 					  GFP_KERNEL);
5319 	if (!err)
5320 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5321 					  GFP_KERNEL);
5322 	if (!err)
5323 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5324 
5325 	if (err) {
5326 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5327 		goto failed_mount6;
5328 	}
5329 
5330 	if (ext4_has_feature_flex_bg(sb))
5331 		if (!ext4_fill_flex_info(sb)) {
5332 			ext4_msg(sb, KERN_ERR,
5333 			       "unable to initialize "
5334 			       "flex_bg meta info!");
5335 			ret = -ENOMEM;
5336 			goto failed_mount6;
5337 		}
5338 
5339 	err = ext4_register_li_request(sb, first_not_zeroed);
5340 	if (err)
5341 		goto failed_mount6;
5342 
5343 	err = ext4_register_sysfs(sb);
5344 	if (err)
5345 		goto failed_mount7;
5346 
5347 	err = ext4_init_orphan_info(sb);
5348 	if (err)
5349 		goto failed_mount8;
5350 #ifdef CONFIG_QUOTA
5351 	/* Enable quota usage during mount. */
5352 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5353 		err = ext4_enable_quotas(sb);
5354 		if (err)
5355 			goto failed_mount9;
5356 	}
5357 #endif  /* CONFIG_QUOTA */
5358 
5359 	/*
5360 	 * Save the original bdev mapping's wb_err value which could be
5361 	 * used to detect the metadata async write error.
5362 	 */
5363 	spin_lock_init(&sbi->s_bdev_wb_lock);
5364 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5365 				 &sbi->s_bdev_wb_err);
5366 	sb->s_bdev->bd_super = sb;
5367 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5368 	ext4_orphan_cleanup(sb, es);
5369 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5370 	if (needs_recovery) {
5371 		ext4_msg(sb, KERN_INFO, "recovery complete");
5372 		err = ext4_mark_recovery_complete(sb, es);
5373 		if (err)
5374 			goto failed_mount9;
5375 	}
5376 
5377 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5378 		ext4_msg(sb, KERN_WARNING,
5379 			 "mounting with \"discard\" option, but the device does not support discard");
5380 
5381 	if (es->s_error_count)
5382 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5383 
5384 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5385 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5386 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5387 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5388 	atomic_set(&sbi->s_warning_count, 0);
5389 	atomic_set(&sbi->s_msg_count, 0);
5390 
5391 	return 0;
5392 
5393 cantfind_ext4:
5394 	if (!silent)
5395 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5396 	goto failed_mount;
5397 
5398 failed_mount9:
5399 	ext4_release_orphan_info(sb);
5400 failed_mount8:
5401 	ext4_unregister_sysfs(sb);
5402 	kobject_put(&sbi->s_kobj);
5403 failed_mount7:
5404 	ext4_unregister_li_request(sb);
5405 failed_mount6:
5406 	ext4_mb_release(sb);
5407 	rcu_read_lock();
5408 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5409 	if (flex_groups) {
5410 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5411 			kvfree(flex_groups[i]);
5412 		kvfree(flex_groups);
5413 	}
5414 	rcu_read_unlock();
5415 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5416 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5417 	percpu_counter_destroy(&sbi->s_dirs_counter);
5418 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5419 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5420 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5421 failed_mount5:
5422 	ext4_ext_release(sb);
5423 	ext4_release_system_zone(sb);
5424 failed_mount4a:
5425 	dput(sb->s_root);
5426 	sb->s_root = NULL;
5427 failed_mount4:
5428 	ext4_msg(sb, KERN_ERR, "mount failed");
5429 	if (EXT4_SB(sb)->rsv_conversion_wq)
5430 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5431 failed_mount_wq:
5432 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5433 	sbi->s_ea_inode_cache = NULL;
5434 
5435 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5436 	sbi->s_ea_block_cache = NULL;
5437 
5438 	if (sbi->s_journal) {
5439 		/* flush s_error_work before journal destroy. */
5440 		flush_work(&sbi->s_error_work);
5441 		jbd2_journal_destroy(sbi->s_journal);
5442 		sbi->s_journal = NULL;
5443 	}
5444 failed_mount3a:
5445 	ext4_es_unregister_shrinker(sbi);
5446 failed_mount3:
5447 	/* flush s_error_work before sbi destroy */
5448 	flush_work(&sbi->s_error_work);
5449 	del_timer_sync(&sbi->s_err_report);
5450 	ext4_stop_mmpd(sbi);
5451 failed_mount2:
5452 	rcu_read_lock();
5453 	group_desc = rcu_dereference(sbi->s_group_desc);
5454 	for (i = 0; i < db_count; i++)
5455 		brelse(group_desc[i]);
5456 	kvfree(group_desc);
5457 	rcu_read_unlock();
5458 failed_mount:
5459 	if (sbi->s_chksum_driver)
5460 		crypto_free_shash(sbi->s_chksum_driver);
5461 
5462 #if IS_ENABLED(CONFIG_UNICODE)
5463 	utf8_unload(sb->s_encoding);
5464 #endif
5465 
5466 #ifdef CONFIG_QUOTA
5467 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5468 		kfree(get_qf_name(sb, sbi, i));
5469 #endif
5470 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5471 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5472 	brelse(bh);
5473 	ext4_blkdev_remove(sbi);
5474 out_fail:
5475 	sb->s_fs_info = NULL;
5476 	return err ? err : ret;
5477 }
5478 
5479 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5480 {
5481 	struct ext4_fs_context *ctx = fc->fs_private;
5482 	struct ext4_sb_info *sbi;
5483 	const char *descr;
5484 	int ret;
5485 
5486 	sbi = ext4_alloc_sbi(sb);
5487 	if (!sbi)
5488 		return -ENOMEM;
5489 
5490 	fc->s_fs_info = sbi;
5491 
5492 	/* Cleanup superblock name */
5493 	strreplace(sb->s_id, '/', '!');
5494 
5495 	sbi->s_sb_block = 1;	/* Default super block location */
5496 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5497 		sbi->s_sb_block = ctx->s_sb_block;
5498 
5499 	ret = __ext4_fill_super(fc, sb);
5500 	if (ret < 0)
5501 		goto free_sbi;
5502 
5503 	if (sbi->s_journal) {
5504 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5505 			descr = " journalled data mode";
5506 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5507 			descr = " ordered data mode";
5508 		else
5509 			descr = " writeback data mode";
5510 	} else
5511 		descr = "out journal";
5512 
5513 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5514 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5515 			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
5516 
5517 	/* Update the s_overhead_clusters if necessary */
5518 	ext4_update_overhead(sb);
5519 	return 0;
5520 
5521 free_sbi:
5522 	ext4_free_sbi(sbi);
5523 	fc->s_fs_info = NULL;
5524 	return ret;
5525 }
5526 
5527 static int ext4_get_tree(struct fs_context *fc)
5528 {
5529 	return get_tree_bdev(fc, ext4_fill_super);
5530 }
5531 
5532 /*
5533  * Setup any per-fs journal parameters now.  We'll do this both on
5534  * initial mount, once the journal has been initialised but before we've
5535  * done any recovery; and again on any subsequent remount.
5536  */
5537 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5538 {
5539 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5540 
5541 	journal->j_commit_interval = sbi->s_commit_interval;
5542 	journal->j_min_batch_time = sbi->s_min_batch_time;
5543 	journal->j_max_batch_time = sbi->s_max_batch_time;
5544 	ext4_fc_init(sb, journal);
5545 
5546 	write_lock(&journal->j_state_lock);
5547 	if (test_opt(sb, BARRIER))
5548 		journal->j_flags |= JBD2_BARRIER;
5549 	else
5550 		journal->j_flags &= ~JBD2_BARRIER;
5551 	if (test_opt(sb, DATA_ERR_ABORT))
5552 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5553 	else
5554 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5555 	write_unlock(&journal->j_state_lock);
5556 }
5557 
5558 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5559 					     unsigned int journal_inum)
5560 {
5561 	struct inode *journal_inode;
5562 
5563 	/*
5564 	 * Test for the existence of a valid inode on disk.  Bad things
5565 	 * happen if we iget() an unused inode, as the subsequent iput()
5566 	 * will try to delete it.
5567 	 */
5568 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5569 	if (IS_ERR(journal_inode)) {
5570 		ext4_msg(sb, KERN_ERR, "no journal found");
5571 		return NULL;
5572 	}
5573 	if (!journal_inode->i_nlink) {
5574 		make_bad_inode(journal_inode);
5575 		iput(journal_inode);
5576 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5577 		return NULL;
5578 	}
5579 
5580 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5581 		  journal_inode, journal_inode->i_size);
5582 	if (!S_ISREG(journal_inode->i_mode)) {
5583 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5584 		iput(journal_inode);
5585 		return NULL;
5586 	}
5587 	return journal_inode;
5588 }
5589 
5590 static journal_t *ext4_get_journal(struct super_block *sb,
5591 				   unsigned int journal_inum)
5592 {
5593 	struct inode *journal_inode;
5594 	journal_t *journal;
5595 
5596 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5597 		return NULL;
5598 
5599 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5600 	if (!journal_inode)
5601 		return NULL;
5602 
5603 	journal = jbd2_journal_init_inode(journal_inode);
5604 	if (!journal) {
5605 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5606 		iput(journal_inode);
5607 		return NULL;
5608 	}
5609 	journal->j_private = sb;
5610 	ext4_init_journal_params(sb, journal);
5611 	return journal;
5612 }
5613 
5614 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5615 				       dev_t j_dev)
5616 {
5617 	struct buffer_head *bh;
5618 	journal_t *journal;
5619 	ext4_fsblk_t start;
5620 	ext4_fsblk_t len;
5621 	int hblock, blocksize;
5622 	ext4_fsblk_t sb_block;
5623 	unsigned long offset;
5624 	struct ext4_super_block *es;
5625 	struct block_device *bdev;
5626 
5627 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5628 		return NULL;
5629 
5630 	bdev = ext4_blkdev_get(j_dev, sb);
5631 	if (bdev == NULL)
5632 		return NULL;
5633 
5634 	blocksize = sb->s_blocksize;
5635 	hblock = bdev_logical_block_size(bdev);
5636 	if (blocksize < hblock) {
5637 		ext4_msg(sb, KERN_ERR,
5638 			"blocksize too small for journal device");
5639 		goto out_bdev;
5640 	}
5641 
5642 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5643 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5644 	set_blocksize(bdev, blocksize);
5645 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5646 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5647 		       "external journal");
5648 		goto out_bdev;
5649 	}
5650 
5651 	es = (struct ext4_super_block *) (bh->b_data + offset);
5652 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5653 	    !(le32_to_cpu(es->s_feature_incompat) &
5654 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5655 		ext4_msg(sb, KERN_ERR, "external journal has "
5656 					"bad superblock");
5657 		brelse(bh);
5658 		goto out_bdev;
5659 	}
5660 
5661 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5662 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5663 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5664 		ext4_msg(sb, KERN_ERR, "external journal has "
5665 				       "corrupt superblock");
5666 		brelse(bh);
5667 		goto out_bdev;
5668 	}
5669 
5670 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5671 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5672 		brelse(bh);
5673 		goto out_bdev;
5674 	}
5675 
5676 	len = ext4_blocks_count(es);
5677 	start = sb_block + 1;
5678 	brelse(bh);	/* we're done with the superblock */
5679 
5680 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5681 					start, len, blocksize);
5682 	if (!journal) {
5683 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5684 		goto out_bdev;
5685 	}
5686 	journal->j_private = sb;
5687 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5688 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5689 		goto out_journal;
5690 	}
5691 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5692 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5693 					"user (unsupported) - %d",
5694 			be32_to_cpu(journal->j_superblock->s_nr_users));
5695 		goto out_journal;
5696 	}
5697 	EXT4_SB(sb)->s_journal_bdev = bdev;
5698 	ext4_init_journal_params(sb, journal);
5699 	return journal;
5700 
5701 out_journal:
5702 	jbd2_journal_destroy(journal);
5703 out_bdev:
5704 	ext4_blkdev_put(bdev);
5705 	return NULL;
5706 }
5707 
5708 static int ext4_load_journal(struct super_block *sb,
5709 			     struct ext4_super_block *es,
5710 			     unsigned long journal_devnum)
5711 {
5712 	journal_t *journal;
5713 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5714 	dev_t journal_dev;
5715 	int err = 0;
5716 	int really_read_only;
5717 	int journal_dev_ro;
5718 
5719 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5720 		return -EFSCORRUPTED;
5721 
5722 	if (journal_devnum &&
5723 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5724 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5725 			"numbers have changed");
5726 		journal_dev = new_decode_dev(journal_devnum);
5727 	} else
5728 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5729 
5730 	if (journal_inum && journal_dev) {
5731 		ext4_msg(sb, KERN_ERR,
5732 			 "filesystem has both journal inode and journal device!");
5733 		return -EINVAL;
5734 	}
5735 
5736 	if (journal_inum) {
5737 		journal = ext4_get_journal(sb, journal_inum);
5738 		if (!journal)
5739 			return -EINVAL;
5740 	} else {
5741 		journal = ext4_get_dev_journal(sb, journal_dev);
5742 		if (!journal)
5743 			return -EINVAL;
5744 	}
5745 
5746 	journal_dev_ro = bdev_read_only(journal->j_dev);
5747 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5748 
5749 	if (journal_dev_ro && !sb_rdonly(sb)) {
5750 		ext4_msg(sb, KERN_ERR,
5751 			 "journal device read-only, try mounting with '-o ro'");
5752 		err = -EROFS;
5753 		goto err_out;
5754 	}
5755 
5756 	/*
5757 	 * Are we loading a blank journal or performing recovery after a
5758 	 * crash?  For recovery, we need to check in advance whether we
5759 	 * can get read-write access to the device.
5760 	 */
5761 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5762 		if (sb_rdonly(sb)) {
5763 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5764 					"required on readonly filesystem");
5765 			if (really_read_only) {
5766 				ext4_msg(sb, KERN_ERR, "write access "
5767 					"unavailable, cannot proceed "
5768 					"(try mounting with noload)");
5769 				err = -EROFS;
5770 				goto err_out;
5771 			}
5772 			ext4_msg(sb, KERN_INFO, "write access will "
5773 			       "be enabled during recovery");
5774 		}
5775 	}
5776 
5777 	if (!(journal->j_flags & JBD2_BARRIER))
5778 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5779 
5780 	if (!ext4_has_feature_journal_needs_recovery(sb))
5781 		err = jbd2_journal_wipe(journal, !really_read_only);
5782 	if (!err) {
5783 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5784 		if (save)
5785 			memcpy(save, ((char *) es) +
5786 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5787 		err = jbd2_journal_load(journal);
5788 		if (save)
5789 			memcpy(((char *) es) + EXT4_S_ERR_START,
5790 			       save, EXT4_S_ERR_LEN);
5791 		kfree(save);
5792 	}
5793 
5794 	if (err) {
5795 		ext4_msg(sb, KERN_ERR, "error loading journal");
5796 		goto err_out;
5797 	}
5798 
5799 	EXT4_SB(sb)->s_journal = journal;
5800 	err = ext4_clear_journal_err(sb, es);
5801 	if (err) {
5802 		EXT4_SB(sb)->s_journal = NULL;
5803 		jbd2_journal_destroy(journal);
5804 		return err;
5805 	}
5806 
5807 	if (!really_read_only && journal_devnum &&
5808 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5809 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5810 
5811 		/* Make sure we flush the recovery flag to disk. */
5812 		ext4_commit_super(sb);
5813 	}
5814 
5815 	return 0;
5816 
5817 err_out:
5818 	jbd2_journal_destroy(journal);
5819 	return err;
5820 }
5821 
5822 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5823 static void ext4_update_super(struct super_block *sb)
5824 {
5825 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5826 	struct ext4_super_block *es = sbi->s_es;
5827 	struct buffer_head *sbh = sbi->s_sbh;
5828 
5829 	lock_buffer(sbh);
5830 	/*
5831 	 * If the file system is mounted read-only, don't update the
5832 	 * superblock write time.  This avoids updating the superblock
5833 	 * write time when we are mounting the root file system
5834 	 * read/only but we need to replay the journal; at that point,
5835 	 * for people who are east of GMT and who make their clock
5836 	 * tick in localtime for Windows bug-for-bug compatibility,
5837 	 * the clock is set in the future, and this will cause e2fsck
5838 	 * to complain and force a full file system check.
5839 	 */
5840 	if (!(sb->s_flags & SB_RDONLY))
5841 		ext4_update_tstamp(es, s_wtime);
5842 	es->s_kbytes_written =
5843 		cpu_to_le64(sbi->s_kbytes_written +
5844 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5845 		      sbi->s_sectors_written_start) >> 1));
5846 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5847 		ext4_free_blocks_count_set(es,
5848 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5849 				&sbi->s_freeclusters_counter)));
5850 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5851 		es->s_free_inodes_count =
5852 			cpu_to_le32(percpu_counter_sum_positive(
5853 				&sbi->s_freeinodes_counter));
5854 	/* Copy error information to the on-disk superblock */
5855 	spin_lock(&sbi->s_error_lock);
5856 	if (sbi->s_add_error_count > 0) {
5857 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5858 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5859 			__ext4_update_tstamp(&es->s_first_error_time,
5860 					     &es->s_first_error_time_hi,
5861 					     sbi->s_first_error_time);
5862 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5863 				sizeof(es->s_first_error_func));
5864 			es->s_first_error_line =
5865 				cpu_to_le32(sbi->s_first_error_line);
5866 			es->s_first_error_ino =
5867 				cpu_to_le32(sbi->s_first_error_ino);
5868 			es->s_first_error_block =
5869 				cpu_to_le64(sbi->s_first_error_block);
5870 			es->s_first_error_errcode =
5871 				ext4_errno_to_code(sbi->s_first_error_code);
5872 		}
5873 		__ext4_update_tstamp(&es->s_last_error_time,
5874 				     &es->s_last_error_time_hi,
5875 				     sbi->s_last_error_time);
5876 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5877 			sizeof(es->s_last_error_func));
5878 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5879 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5880 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5881 		es->s_last_error_errcode =
5882 				ext4_errno_to_code(sbi->s_last_error_code);
5883 		/*
5884 		 * Start the daily error reporting function if it hasn't been
5885 		 * started already
5886 		 */
5887 		if (!es->s_error_count)
5888 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5889 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5890 		sbi->s_add_error_count = 0;
5891 	}
5892 	spin_unlock(&sbi->s_error_lock);
5893 
5894 	ext4_superblock_csum_set(sb);
5895 	unlock_buffer(sbh);
5896 }
5897 
5898 static int ext4_commit_super(struct super_block *sb)
5899 {
5900 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5901 	int error = 0;
5902 
5903 	if (!sbh)
5904 		return -EINVAL;
5905 	if (block_device_ejected(sb))
5906 		return -ENODEV;
5907 
5908 	ext4_update_super(sb);
5909 
5910 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5911 		/*
5912 		 * Oh, dear.  A previous attempt to write the
5913 		 * superblock failed.  This could happen because the
5914 		 * USB device was yanked out.  Or it could happen to
5915 		 * be a transient write error and maybe the block will
5916 		 * be remapped.  Nothing we can do but to retry the
5917 		 * write and hope for the best.
5918 		 */
5919 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5920 		       "superblock detected");
5921 		clear_buffer_write_io_error(sbh);
5922 		set_buffer_uptodate(sbh);
5923 	}
5924 	BUFFER_TRACE(sbh, "marking dirty");
5925 	mark_buffer_dirty(sbh);
5926 	error = __sync_dirty_buffer(sbh,
5927 		REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5928 	if (buffer_write_io_error(sbh)) {
5929 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
5930 		       "superblock");
5931 		clear_buffer_write_io_error(sbh);
5932 		set_buffer_uptodate(sbh);
5933 	}
5934 	return error;
5935 }
5936 
5937 /*
5938  * Have we just finished recovery?  If so, and if we are mounting (or
5939  * remounting) the filesystem readonly, then we will end up with a
5940  * consistent fs on disk.  Record that fact.
5941  */
5942 static int ext4_mark_recovery_complete(struct super_block *sb,
5943 				       struct ext4_super_block *es)
5944 {
5945 	int err;
5946 	journal_t *journal = EXT4_SB(sb)->s_journal;
5947 
5948 	if (!ext4_has_feature_journal(sb)) {
5949 		if (journal != NULL) {
5950 			ext4_error(sb, "Journal got removed while the fs was "
5951 				   "mounted!");
5952 			return -EFSCORRUPTED;
5953 		}
5954 		return 0;
5955 	}
5956 	jbd2_journal_lock_updates(journal);
5957 	err = jbd2_journal_flush(journal, 0);
5958 	if (err < 0)
5959 		goto out;
5960 
5961 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
5962 	    ext4_has_feature_orphan_present(sb))) {
5963 		if (!ext4_orphan_file_empty(sb)) {
5964 			ext4_error(sb, "Orphan file not empty on read-only fs.");
5965 			err = -EFSCORRUPTED;
5966 			goto out;
5967 		}
5968 		ext4_clear_feature_journal_needs_recovery(sb);
5969 		ext4_clear_feature_orphan_present(sb);
5970 		ext4_commit_super(sb);
5971 	}
5972 out:
5973 	jbd2_journal_unlock_updates(journal);
5974 	return err;
5975 }
5976 
5977 /*
5978  * If we are mounting (or read-write remounting) a filesystem whose journal
5979  * has recorded an error from a previous lifetime, move that error to the
5980  * main filesystem now.
5981  */
5982 static int ext4_clear_journal_err(struct super_block *sb,
5983 				   struct ext4_super_block *es)
5984 {
5985 	journal_t *journal;
5986 	int j_errno;
5987 	const char *errstr;
5988 
5989 	if (!ext4_has_feature_journal(sb)) {
5990 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5991 		return -EFSCORRUPTED;
5992 	}
5993 
5994 	journal = EXT4_SB(sb)->s_journal;
5995 
5996 	/*
5997 	 * Now check for any error status which may have been recorded in the
5998 	 * journal by a prior ext4_error() or ext4_abort()
5999 	 */
6000 
6001 	j_errno = jbd2_journal_errno(journal);
6002 	if (j_errno) {
6003 		char nbuf[16];
6004 
6005 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6006 		ext4_warning(sb, "Filesystem error recorded "
6007 			     "from previous mount: %s", errstr);
6008 		ext4_warning(sb, "Marking fs in need of filesystem check.");
6009 
6010 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6011 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6012 		ext4_commit_super(sb);
6013 
6014 		jbd2_journal_clear_err(journal);
6015 		jbd2_journal_update_sb_errno(journal);
6016 	}
6017 	return 0;
6018 }
6019 
6020 /*
6021  * Force the running and committing transactions to commit,
6022  * and wait on the commit.
6023  */
6024 int ext4_force_commit(struct super_block *sb)
6025 {
6026 	journal_t *journal;
6027 
6028 	if (sb_rdonly(sb))
6029 		return 0;
6030 
6031 	journal = EXT4_SB(sb)->s_journal;
6032 	return ext4_journal_force_commit(journal);
6033 }
6034 
6035 static int ext4_sync_fs(struct super_block *sb, int wait)
6036 {
6037 	int ret = 0;
6038 	tid_t target;
6039 	bool needs_barrier = false;
6040 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6041 
6042 	if (unlikely(ext4_forced_shutdown(sbi)))
6043 		return 0;
6044 
6045 	trace_ext4_sync_fs(sb, wait);
6046 	flush_workqueue(sbi->rsv_conversion_wq);
6047 	/*
6048 	 * Writeback quota in non-journalled quota case - journalled quota has
6049 	 * no dirty dquots
6050 	 */
6051 	dquot_writeback_dquots(sb, -1);
6052 	/*
6053 	 * Data writeback is possible w/o journal transaction, so barrier must
6054 	 * being sent at the end of the function. But we can skip it if
6055 	 * transaction_commit will do it for us.
6056 	 */
6057 	if (sbi->s_journal) {
6058 		target = jbd2_get_latest_transaction(sbi->s_journal);
6059 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6060 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6061 			needs_barrier = true;
6062 
6063 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6064 			if (wait)
6065 				ret = jbd2_log_wait_commit(sbi->s_journal,
6066 							   target);
6067 		}
6068 	} else if (wait && test_opt(sb, BARRIER))
6069 		needs_barrier = true;
6070 	if (needs_barrier) {
6071 		int err;
6072 		err = blkdev_issue_flush(sb->s_bdev);
6073 		if (!ret)
6074 			ret = err;
6075 	}
6076 
6077 	return ret;
6078 }
6079 
6080 /*
6081  * LVM calls this function before a (read-only) snapshot is created.  This
6082  * gives us a chance to flush the journal completely and mark the fs clean.
6083  *
6084  * Note that only this function cannot bring a filesystem to be in a clean
6085  * state independently. It relies on upper layer to stop all data & metadata
6086  * modifications.
6087  */
6088 static int ext4_freeze(struct super_block *sb)
6089 {
6090 	int error = 0;
6091 	journal_t *journal;
6092 
6093 	if (sb_rdonly(sb))
6094 		return 0;
6095 
6096 	journal = EXT4_SB(sb)->s_journal;
6097 
6098 	if (journal) {
6099 		/* Now we set up the journal barrier. */
6100 		jbd2_journal_lock_updates(journal);
6101 
6102 		/*
6103 		 * Don't clear the needs_recovery flag if we failed to
6104 		 * flush the journal.
6105 		 */
6106 		error = jbd2_journal_flush(journal, 0);
6107 		if (error < 0)
6108 			goto out;
6109 
6110 		/* Journal blocked and flushed, clear needs_recovery flag. */
6111 		ext4_clear_feature_journal_needs_recovery(sb);
6112 		if (ext4_orphan_file_empty(sb))
6113 			ext4_clear_feature_orphan_present(sb);
6114 	}
6115 
6116 	error = ext4_commit_super(sb);
6117 out:
6118 	if (journal)
6119 		/* we rely on upper layer to stop further updates */
6120 		jbd2_journal_unlock_updates(journal);
6121 	return error;
6122 }
6123 
6124 /*
6125  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6126  * flag here, even though the filesystem is not technically dirty yet.
6127  */
6128 static int ext4_unfreeze(struct super_block *sb)
6129 {
6130 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6131 		return 0;
6132 
6133 	if (EXT4_SB(sb)->s_journal) {
6134 		/* Reset the needs_recovery flag before the fs is unlocked. */
6135 		ext4_set_feature_journal_needs_recovery(sb);
6136 		if (ext4_has_feature_orphan_file(sb))
6137 			ext4_set_feature_orphan_present(sb);
6138 	}
6139 
6140 	ext4_commit_super(sb);
6141 	return 0;
6142 }
6143 
6144 /*
6145  * Structure to save mount options for ext4_remount's benefit
6146  */
6147 struct ext4_mount_options {
6148 	unsigned long s_mount_opt;
6149 	unsigned long s_mount_opt2;
6150 	kuid_t s_resuid;
6151 	kgid_t s_resgid;
6152 	unsigned long s_commit_interval;
6153 	u32 s_min_batch_time, s_max_batch_time;
6154 #ifdef CONFIG_QUOTA
6155 	int s_jquota_fmt;
6156 	char *s_qf_names[EXT4_MAXQUOTAS];
6157 #endif
6158 };
6159 
6160 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6161 {
6162 	struct ext4_fs_context *ctx = fc->fs_private;
6163 	struct ext4_super_block *es;
6164 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6165 	unsigned long old_sb_flags;
6166 	struct ext4_mount_options old_opts;
6167 	ext4_group_t g;
6168 	int err = 0;
6169 #ifdef CONFIG_QUOTA
6170 	int enable_quota = 0;
6171 	int i, j;
6172 	char *to_free[EXT4_MAXQUOTAS];
6173 #endif
6174 
6175 
6176 	/* Store the original options */
6177 	old_sb_flags = sb->s_flags;
6178 	old_opts.s_mount_opt = sbi->s_mount_opt;
6179 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6180 	old_opts.s_resuid = sbi->s_resuid;
6181 	old_opts.s_resgid = sbi->s_resgid;
6182 	old_opts.s_commit_interval = sbi->s_commit_interval;
6183 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6184 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6185 #ifdef CONFIG_QUOTA
6186 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6187 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6188 		if (sbi->s_qf_names[i]) {
6189 			char *qf_name = get_qf_name(sb, sbi, i);
6190 
6191 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6192 			if (!old_opts.s_qf_names[i]) {
6193 				for (j = 0; j < i; j++)
6194 					kfree(old_opts.s_qf_names[j]);
6195 				return -ENOMEM;
6196 			}
6197 		} else
6198 			old_opts.s_qf_names[i] = NULL;
6199 #endif
6200 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6201 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6202 			ctx->journal_ioprio =
6203 				sbi->s_journal->j_task->io_context->ioprio;
6204 		else
6205 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6206 
6207 	}
6208 
6209 	ext4_apply_options(fc, sb);
6210 
6211 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6212 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6213 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6214 			 "during remount not supported; ignoring");
6215 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6216 	}
6217 
6218 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6219 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6220 			ext4_msg(sb, KERN_ERR, "can't mount with "
6221 				 "both data=journal and delalloc");
6222 			err = -EINVAL;
6223 			goto restore_opts;
6224 		}
6225 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6226 			ext4_msg(sb, KERN_ERR, "can't mount with "
6227 				 "both data=journal and dioread_nolock");
6228 			err = -EINVAL;
6229 			goto restore_opts;
6230 		}
6231 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6232 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6233 			ext4_msg(sb, KERN_ERR, "can't mount with "
6234 				"journal_async_commit in data=ordered mode");
6235 			err = -EINVAL;
6236 			goto restore_opts;
6237 		}
6238 	}
6239 
6240 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6241 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6242 		err = -EINVAL;
6243 		goto restore_opts;
6244 	}
6245 
6246 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6247 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6248 
6249 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6250 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6251 
6252 	es = sbi->s_es;
6253 
6254 	if (sbi->s_journal) {
6255 		ext4_init_journal_params(sb, sbi->s_journal);
6256 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6257 	}
6258 
6259 	/* Flush outstanding errors before changing fs state */
6260 	flush_work(&sbi->s_error_work);
6261 
6262 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6263 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6264 			err = -EROFS;
6265 			goto restore_opts;
6266 		}
6267 
6268 		if (fc->sb_flags & SB_RDONLY) {
6269 			err = sync_filesystem(sb);
6270 			if (err < 0)
6271 				goto restore_opts;
6272 			err = dquot_suspend(sb, -1);
6273 			if (err < 0)
6274 				goto restore_opts;
6275 
6276 			/*
6277 			 * First of all, the unconditional stuff we have to do
6278 			 * to disable replay of the journal when we next remount
6279 			 */
6280 			sb->s_flags |= SB_RDONLY;
6281 
6282 			/*
6283 			 * OK, test if we are remounting a valid rw partition
6284 			 * readonly, and if so set the rdonly flag and then
6285 			 * mark the partition as valid again.
6286 			 */
6287 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6288 			    (sbi->s_mount_state & EXT4_VALID_FS))
6289 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6290 
6291 			if (sbi->s_journal) {
6292 				/*
6293 				 * We let remount-ro finish even if marking fs
6294 				 * as clean failed...
6295 				 */
6296 				ext4_mark_recovery_complete(sb, es);
6297 			}
6298 		} else {
6299 			/* Make sure we can mount this feature set readwrite */
6300 			if (ext4_has_feature_readonly(sb) ||
6301 			    !ext4_feature_set_ok(sb, 0)) {
6302 				err = -EROFS;
6303 				goto restore_opts;
6304 			}
6305 			/*
6306 			 * Make sure the group descriptor checksums
6307 			 * are sane.  If they aren't, refuse to remount r/w.
6308 			 */
6309 			for (g = 0; g < sbi->s_groups_count; g++) {
6310 				struct ext4_group_desc *gdp =
6311 					ext4_get_group_desc(sb, g, NULL);
6312 
6313 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6314 					ext4_msg(sb, KERN_ERR,
6315 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6316 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6317 					       le16_to_cpu(gdp->bg_checksum));
6318 					err = -EFSBADCRC;
6319 					goto restore_opts;
6320 				}
6321 			}
6322 
6323 			/*
6324 			 * If we have an unprocessed orphan list hanging
6325 			 * around from a previously readonly bdev mount,
6326 			 * require a full umount/remount for now.
6327 			 */
6328 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6329 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6330 				       "remount RDWR because of unprocessed "
6331 				       "orphan inode list.  Please "
6332 				       "umount/remount instead");
6333 				err = -EINVAL;
6334 				goto restore_opts;
6335 			}
6336 
6337 			/*
6338 			 * Mounting a RDONLY partition read-write, so reread
6339 			 * and store the current valid flag.  (It may have
6340 			 * been changed by e2fsck since we originally mounted
6341 			 * the partition.)
6342 			 */
6343 			if (sbi->s_journal) {
6344 				err = ext4_clear_journal_err(sb, es);
6345 				if (err)
6346 					goto restore_opts;
6347 			}
6348 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6349 					      ~EXT4_FC_REPLAY);
6350 
6351 			err = ext4_setup_super(sb, es, 0);
6352 			if (err)
6353 				goto restore_opts;
6354 
6355 			sb->s_flags &= ~SB_RDONLY;
6356 			if (ext4_has_feature_mmp(sb))
6357 				if (ext4_multi_mount_protect(sb,
6358 						le64_to_cpu(es->s_mmp_block))) {
6359 					err = -EROFS;
6360 					goto restore_opts;
6361 				}
6362 #ifdef CONFIG_QUOTA
6363 			enable_quota = 1;
6364 #endif
6365 		}
6366 	}
6367 
6368 	/*
6369 	 * Reinitialize lazy itable initialization thread based on
6370 	 * current settings
6371 	 */
6372 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6373 		ext4_unregister_li_request(sb);
6374 	else {
6375 		ext4_group_t first_not_zeroed;
6376 		first_not_zeroed = ext4_has_uninit_itable(sb);
6377 		ext4_register_li_request(sb, first_not_zeroed);
6378 	}
6379 
6380 	/*
6381 	 * Handle creation of system zone data early because it can fail.
6382 	 * Releasing of existing data is done when we are sure remount will
6383 	 * succeed.
6384 	 */
6385 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6386 		err = ext4_setup_system_zone(sb);
6387 		if (err)
6388 			goto restore_opts;
6389 	}
6390 
6391 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6392 		err = ext4_commit_super(sb);
6393 		if (err)
6394 			goto restore_opts;
6395 	}
6396 
6397 #ifdef CONFIG_QUOTA
6398 	/* Release old quota file names */
6399 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6400 		kfree(old_opts.s_qf_names[i]);
6401 	if (enable_quota) {
6402 		if (sb_any_quota_suspended(sb))
6403 			dquot_resume(sb, -1);
6404 		else if (ext4_has_feature_quota(sb)) {
6405 			err = ext4_enable_quotas(sb);
6406 			if (err)
6407 				goto restore_opts;
6408 		}
6409 	}
6410 #endif
6411 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6412 		ext4_release_system_zone(sb);
6413 
6414 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6415 		ext4_stop_mmpd(sbi);
6416 
6417 	return 0;
6418 
6419 restore_opts:
6420 	sb->s_flags = old_sb_flags;
6421 	sbi->s_mount_opt = old_opts.s_mount_opt;
6422 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6423 	sbi->s_resuid = old_opts.s_resuid;
6424 	sbi->s_resgid = old_opts.s_resgid;
6425 	sbi->s_commit_interval = old_opts.s_commit_interval;
6426 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6427 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6428 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6429 		ext4_release_system_zone(sb);
6430 #ifdef CONFIG_QUOTA
6431 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6432 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6433 		to_free[i] = get_qf_name(sb, sbi, i);
6434 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6435 	}
6436 	synchronize_rcu();
6437 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6438 		kfree(to_free[i]);
6439 #endif
6440 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6441 		ext4_stop_mmpd(sbi);
6442 	return err;
6443 }
6444 
6445 static int ext4_reconfigure(struct fs_context *fc)
6446 {
6447 	struct super_block *sb = fc->root->d_sb;
6448 	int ret;
6449 
6450 	fc->s_fs_info = EXT4_SB(sb);
6451 
6452 	ret = ext4_check_opt_consistency(fc, sb);
6453 	if (ret < 0)
6454 		return ret;
6455 
6456 	ret = __ext4_remount(fc, sb);
6457 	if (ret < 0)
6458 		return ret;
6459 
6460 	ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6461 		 ext4_quota_mode(sb));
6462 
6463 	return 0;
6464 }
6465 
6466 #ifdef CONFIG_QUOTA
6467 static int ext4_statfs_project(struct super_block *sb,
6468 			       kprojid_t projid, struct kstatfs *buf)
6469 {
6470 	struct kqid qid;
6471 	struct dquot *dquot;
6472 	u64 limit;
6473 	u64 curblock;
6474 
6475 	qid = make_kqid_projid(projid);
6476 	dquot = dqget(sb, qid);
6477 	if (IS_ERR(dquot))
6478 		return PTR_ERR(dquot);
6479 	spin_lock(&dquot->dq_dqb_lock);
6480 
6481 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6482 			     dquot->dq_dqb.dqb_bhardlimit);
6483 	limit >>= sb->s_blocksize_bits;
6484 
6485 	if (limit && buf->f_blocks > limit) {
6486 		curblock = (dquot->dq_dqb.dqb_curspace +
6487 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6488 		buf->f_blocks = limit;
6489 		buf->f_bfree = buf->f_bavail =
6490 			(buf->f_blocks > curblock) ?
6491 			 (buf->f_blocks - curblock) : 0;
6492 	}
6493 
6494 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6495 			     dquot->dq_dqb.dqb_ihardlimit);
6496 	if (limit && buf->f_files > limit) {
6497 		buf->f_files = limit;
6498 		buf->f_ffree =
6499 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6500 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6501 	}
6502 
6503 	spin_unlock(&dquot->dq_dqb_lock);
6504 	dqput(dquot);
6505 	return 0;
6506 }
6507 #endif
6508 
6509 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6510 {
6511 	struct super_block *sb = dentry->d_sb;
6512 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6513 	struct ext4_super_block *es = sbi->s_es;
6514 	ext4_fsblk_t overhead = 0, resv_blocks;
6515 	s64 bfree;
6516 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6517 
6518 	if (!test_opt(sb, MINIX_DF))
6519 		overhead = sbi->s_overhead;
6520 
6521 	buf->f_type = EXT4_SUPER_MAGIC;
6522 	buf->f_bsize = sb->s_blocksize;
6523 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6524 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6525 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6526 	/* prevent underflow in case that few free space is available */
6527 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6528 	buf->f_bavail = buf->f_bfree -
6529 			(ext4_r_blocks_count(es) + resv_blocks);
6530 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6531 		buf->f_bavail = 0;
6532 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6533 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6534 	buf->f_namelen = EXT4_NAME_LEN;
6535 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6536 
6537 #ifdef CONFIG_QUOTA
6538 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6539 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6540 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6541 #endif
6542 	return 0;
6543 }
6544 
6545 
6546 #ifdef CONFIG_QUOTA
6547 
6548 /*
6549  * Helper functions so that transaction is started before we acquire dqio_sem
6550  * to keep correct lock ordering of transaction > dqio_sem
6551  */
6552 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6553 {
6554 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6555 }
6556 
6557 static int ext4_write_dquot(struct dquot *dquot)
6558 {
6559 	int ret, err;
6560 	handle_t *handle;
6561 	struct inode *inode;
6562 
6563 	inode = dquot_to_inode(dquot);
6564 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6565 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6566 	if (IS_ERR(handle))
6567 		return PTR_ERR(handle);
6568 	ret = dquot_commit(dquot);
6569 	err = ext4_journal_stop(handle);
6570 	if (!ret)
6571 		ret = err;
6572 	return ret;
6573 }
6574 
6575 static int ext4_acquire_dquot(struct dquot *dquot)
6576 {
6577 	int ret, err;
6578 	handle_t *handle;
6579 
6580 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6581 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6582 	if (IS_ERR(handle))
6583 		return PTR_ERR(handle);
6584 	ret = dquot_acquire(dquot);
6585 	err = ext4_journal_stop(handle);
6586 	if (!ret)
6587 		ret = err;
6588 	return ret;
6589 }
6590 
6591 static int ext4_release_dquot(struct dquot *dquot)
6592 {
6593 	int ret, err;
6594 	handle_t *handle;
6595 
6596 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6597 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6598 	if (IS_ERR(handle)) {
6599 		/* Release dquot anyway to avoid endless cycle in dqput() */
6600 		dquot_release(dquot);
6601 		return PTR_ERR(handle);
6602 	}
6603 	ret = dquot_release(dquot);
6604 	err = ext4_journal_stop(handle);
6605 	if (!ret)
6606 		ret = err;
6607 	return ret;
6608 }
6609 
6610 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6611 {
6612 	struct super_block *sb = dquot->dq_sb;
6613 
6614 	if (ext4_is_quota_journalled(sb)) {
6615 		dquot_mark_dquot_dirty(dquot);
6616 		return ext4_write_dquot(dquot);
6617 	} else {
6618 		return dquot_mark_dquot_dirty(dquot);
6619 	}
6620 }
6621 
6622 static int ext4_write_info(struct super_block *sb, int type)
6623 {
6624 	int ret, err;
6625 	handle_t *handle;
6626 
6627 	/* Data block + inode block */
6628 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6629 	if (IS_ERR(handle))
6630 		return PTR_ERR(handle);
6631 	ret = dquot_commit_info(sb, type);
6632 	err = ext4_journal_stop(handle);
6633 	if (!ret)
6634 		ret = err;
6635 	return ret;
6636 }
6637 
6638 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6639 {
6640 	struct ext4_inode_info *ei = EXT4_I(inode);
6641 
6642 	/* The first argument of lockdep_set_subclass has to be
6643 	 * *exactly* the same as the argument to init_rwsem() --- in
6644 	 * this case, in init_once() --- or lockdep gets unhappy
6645 	 * because the name of the lock is set using the
6646 	 * stringification of the argument to init_rwsem().
6647 	 */
6648 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6649 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6650 }
6651 
6652 /*
6653  * Standard function to be called on quota_on
6654  */
6655 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6656 			 const struct path *path)
6657 {
6658 	int err;
6659 
6660 	if (!test_opt(sb, QUOTA))
6661 		return -EINVAL;
6662 
6663 	/* Quotafile not on the same filesystem? */
6664 	if (path->dentry->d_sb != sb)
6665 		return -EXDEV;
6666 
6667 	/* Quota already enabled for this file? */
6668 	if (IS_NOQUOTA(d_inode(path->dentry)))
6669 		return -EBUSY;
6670 
6671 	/* Journaling quota? */
6672 	if (EXT4_SB(sb)->s_qf_names[type]) {
6673 		/* Quotafile not in fs root? */
6674 		if (path->dentry->d_parent != sb->s_root)
6675 			ext4_msg(sb, KERN_WARNING,
6676 				"Quota file not on filesystem root. "
6677 				"Journaled quota will not work");
6678 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6679 	} else {
6680 		/*
6681 		 * Clear the flag just in case mount options changed since
6682 		 * last time.
6683 		 */
6684 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6685 	}
6686 
6687 	/*
6688 	 * When we journal data on quota file, we have to flush journal to see
6689 	 * all updates to the file when we bypass pagecache...
6690 	 */
6691 	if (EXT4_SB(sb)->s_journal &&
6692 	    ext4_should_journal_data(d_inode(path->dentry))) {
6693 		/*
6694 		 * We don't need to lock updates but journal_flush() could
6695 		 * otherwise be livelocked...
6696 		 */
6697 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6698 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6699 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6700 		if (err)
6701 			return err;
6702 	}
6703 
6704 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6705 	err = dquot_quota_on(sb, type, format_id, path);
6706 	if (!err) {
6707 		struct inode *inode = d_inode(path->dentry);
6708 		handle_t *handle;
6709 
6710 		/*
6711 		 * Set inode flags to prevent userspace from messing with quota
6712 		 * files. If this fails, we return success anyway since quotas
6713 		 * are already enabled and this is not a hard failure.
6714 		 */
6715 		inode_lock(inode);
6716 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6717 		if (IS_ERR(handle))
6718 			goto unlock_inode;
6719 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6720 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6721 				S_NOATIME | S_IMMUTABLE);
6722 		err = ext4_mark_inode_dirty(handle, inode);
6723 		ext4_journal_stop(handle);
6724 	unlock_inode:
6725 		inode_unlock(inode);
6726 		if (err)
6727 			dquot_quota_off(sb, type);
6728 	}
6729 	if (err)
6730 		lockdep_set_quota_inode(path->dentry->d_inode,
6731 					     I_DATA_SEM_NORMAL);
6732 	return err;
6733 }
6734 
6735 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6736 			     unsigned int flags)
6737 {
6738 	int err;
6739 	struct inode *qf_inode;
6740 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6741 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6742 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6743 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6744 	};
6745 
6746 	BUG_ON(!ext4_has_feature_quota(sb));
6747 
6748 	if (!qf_inums[type])
6749 		return -EPERM;
6750 
6751 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6752 	if (IS_ERR(qf_inode)) {
6753 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6754 		return PTR_ERR(qf_inode);
6755 	}
6756 
6757 	/* Don't account quota for quota files to avoid recursion */
6758 	qf_inode->i_flags |= S_NOQUOTA;
6759 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6760 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6761 	if (err)
6762 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6763 	iput(qf_inode);
6764 
6765 	return err;
6766 }
6767 
6768 /* Enable usage tracking for all quota types. */
6769 int ext4_enable_quotas(struct super_block *sb)
6770 {
6771 	int type, err = 0;
6772 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6773 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6774 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6775 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6776 	};
6777 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6778 		test_opt(sb, USRQUOTA),
6779 		test_opt(sb, GRPQUOTA),
6780 		test_opt(sb, PRJQUOTA),
6781 	};
6782 
6783 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6784 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6785 		if (qf_inums[type]) {
6786 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6787 				DQUOT_USAGE_ENABLED |
6788 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6789 			if (err) {
6790 				ext4_warning(sb,
6791 					"Failed to enable quota tracking "
6792 					"(type=%d, err=%d). Please run "
6793 					"e2fsck to fix.", type, err);
6794 				for (type--; type >= 0; type--) {
6795 					struct inode *inode;
6796 
6797 					inode = sb_dqopt(sb)->files[type];
6798 					if (inode)
6799 						inode = igrab(inode);
6800 					dquot_quota_off(sb, type);
6801 					if (inode) {
6802 						lockdep_set_quota_inode(inode,
6803 							I_DATA_SEM_NORMAL);
6804 						iput(inode);
6805 					}
6806 				}
6807 
6808 				return err;
6809 			}
6810 		}
6811 	}
6812 	return 0;
6813 }
6814 
6815 static int ext4_quota_off(struct super_block *sb, int type)
6816 {
6817 	struct inode *inode = sb_dqopt(sb)->files[type];
6818 	handle_t *handle;
6819 	int err;
6820 
6821 	/* Force all delayed allocation blocks to be allocated.
6822 	 * Caller already holds s_umount sem */
6823 	if (test_opt(sb, DELALLOC))
6824 		sync_filesystem(sb);
6825 
6826 	if (!inode || !igrab(inode))
6827 		goto out;
6828 
6829 	err = dquot_quota_off(sb, type);
6830 	if (err || ext4_has_feature_quota(sb))
6831 		goto out_put;
6832 
6833 	inode_lock(inode);
6834 	/*
6835 	 * Update modification times of quota files when userspace can
6836 	 * start looking at them. If we fail, we return success anyway since
6837 	 * this is not a hard failure and quotas are already disabled.
6838 	 */
6839 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6840 	if (IS_ERR(handle)) {
6841 		err = PTR_ERR(handle);
6842 		goto out_unlock;
6843 	}
6844 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6845 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6846 	inode->i_mtime = inode->i_ctime = current_time(inode);
6847 	err = ext4_mark_inode_dirty(handle, inode);
6848 	ext4_journal_stop(handle);
6849 out_unlock:
6850 	inode_unlock(inode);
6851 out_put:
6852 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6853 	iput(inode);
6854 	return err;
6855 out:
6856 	return dquot_quota_off(sb, type);
6857 }
6858 
6859 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6860  * acquiring the locks... As quota files are never truncated and quota code
6861  * itself serializes the operations (and no one else should touch the files)
6862  * we don't have to be afraid of races */
6863 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6864 			       size_t len, loff_t off)
6865 {
6866 	struct inode *inode = sb_dqopt(sb)->files[type];
6867 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6868 	int offset = off & (sb->s_blocksize - 1);
6869 	int tocopy;
6870 	size_t toread;
6871 	struct buffer_head *bh;
6872 	loff_t i_size = i_size_read(inode);
6873 
6874 	if (off > i_size)
6875 		return 0;
6876 	if (off+len > i_size)
6877 		len = i_size-off;
6878 	toread = len;
6879 	while (toread > 0) {
6880 		tocopy = sb->s_blocksize - offset < toread ?
6881 				sb->s_blocksize - offset : toread;
6882 		bh = ext4_bread(NULL, inode, blk, 0);
6883 		if (IS_ERR(bh))
6884 			return PTR_ERR(bh);
6885 		if (!bh)	/* A hole? */
6886 			memset(data, 0, tocopy);
6887 		else
6888 			memcpy(data, bh->b_data+offset, tocopy);
6889 		brelse(bh);
6890 		offset = 0;
6891 		toread -= tocopy;
6892 		data += tocopy;
6893 		blk++;
6894 	}
6895 	return len;
6896 }
6897 
6898 /* Write to quotafile (we know the transaction is already started and has
6899  * enough credits) */
6900 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6901 				const char *data, size_t len, loff_t off)
6902 {
6903 	struct inode *inode = sb_dqopt(sb)->files[type];
6904 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6905 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6906 	int retries = 0;
6907 	struct buffer_head *bh;
6908 	handle_t *handle = journal_current_handle();
6909 
6910 	if (!handle) {
6911 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6912 			" cancelled because transaction is not started",
6913 			(unsigned long long)off, (unsigned long long)len);
6914 		return -EIO;
6915 	}
6916 	/*
6917 	 * Since we account only one data block in transaction credits,
6918 	 * then it is impossible to cross a block boundary.
6919 	 */
6920 	if (sb->s_blocksize - offset < len) {
6921 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6922 			" cancelled because not block aligned",
6923 			(unsigned long long)off, (unsigned long long)len);
6924 		return -EIO;
6925 	}
6926 
6927 	do {
6928 		bh = ext4_bread(handle, inode, blk,
6929 				EXT4_GET_BLOCKS_CREATE |
6930 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6931 	} while (PTR_ERR(bh) == -ENOSPC &&
6932 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6933 	if (IS_ERR(bh))
6934 		return PTR_ERR(bh);
6935 	if (!bh)
6936 		goto out;
6937 	BUFFER_TRACE(bh, "get write access");
6938 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
6939 	if (err) {
6940 		brelse(bh);
6941 		return err;
6942 	}
6943 	lock_buffer(bh);
6944 	memcpy(bh->b_data+offset, data, len);
6945 	flush_dcache_page(bh->b_page);
6946 	unlock_buffer(bh);
6947 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6948 	brelse(bh);
6949 out:
6950 	if (inode->i_size < off + len) {
6951 		i_size_write(inode, off + len);
6952 		EXT4_I(inode)->i_disksize = inode->i_size;
6953 		err2 = ext4_mark_inode_dirty(handle, inode);
6954 		if (unlikely(err2 && !err))
6955 			err = err2;
6956 	}
6957 	return err ? err : len;
6958 }
6959 #endif
6960 
6961 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6962 static inline void register_as_ext2(void)
6963 {
6964 	int err = register_filesystem(&ext2_fs_type);
6965 	if (err)
6966 		printk(KERN_WARNING
6967 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6968 }
6969 
6970 static inline void unregister_as_ext2(void)
6971 {
6972 	unregister_filesystem(&ext2_fs_type);
6973 }
6974 
6975 static inline int ext2_feature_set_ok(struct super_block *sb)
6976 {
6977 	if (ext4_has_unknown_ext2_incompat_features(sb))
6978 		return 0;
6979 	if (sb_rdonly(sb))
6980 		return 1;
6981 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6982 		return 0;
6983 	return 1;
6984 }
6985 #else
6986 static inline void register_as_ext2(void) { }
6987 static inline void unregister_as_ext2(void) { }
6988 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6989 #endif
6990 
6991 static inline void register_as_ext3(void)
6992 {
6993 	int err = register_filesystem(&ext3_fs_type);
6994 	if (err)
6995 		printk(KERN_WARNING
6996 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6997 }
6998 
6999 static inline void unregister_as_ext3(void)
7000 {
7001 	unregister_filesystem(&ext3_fs_type);
7002 }
7003 
7004 static inline int ext3_feature_set_ok(struct super_block *sb)
7005 {
7006 	if (ext4_has_unknown_ext3_incompat_features(sb))
7007 		return 0;
7008 	if (!ext4_has_feature_journal(sb))
7009 		return 0;
7010 	if (sb_rdonly(sb))
7011 		return 1;
7012 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7013 		return 0;
7014 	return 1;
7015 }
7016 
7017 static struct file_system_type ext4_fs_type = {
7018 	.owner			= THIS_MODULE,
7019 	.name			= "ext4",
7020 	.init_fs_context	= ext4_init_fs_context,
7021 	.parameters		= ext4_param_specs,
7022 	.kill_sb		= kill_block_super,
7023 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7024 };
7025 MODULE_ALIAS_FS("ext4");
7026 
7027 /* Shared across all ext4 file systems */
7028 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7029 
7030 static int __init ext4_init_fs(void)
7031 {
7032 	int i, err;
7033 
7034 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7035 	ext4_li_info = NULL;
7036 
7037 	/* Build-time check for flags consistency */
7038 	ext4_check_flag_values();
7039 
7040 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7041 		init_waitqueue_head(&ext4__ioend_wq[i]);
7042 
7043 	err = ext4_init_es();
7044 	if (err)
7045 		return err;
7046 
7047 	err = ext4_init_pending();
7048 	if (err)
7049 		goto out7;
7050 
7051 	err = ext4_init_post_read_processing();
7052 	if (err)
7053 		goto out6;
7054 
7055 	err = ext4_init_pageio();
7056 	if (err)
7057 		goto out5;
7058 
7059 	err = ext4_init_system_zone();
7060 	if (err)
7061 		goto out4;
7062 
7063 	err = ext4_init_sysfs();
7064 	if (err)
7065 		goto out3;
7066 
7067 	err = ext4_init_mballoc();
7068 	if (err)
7069 		goto out2;
7070 	err = init_inodecache();
7071 	if (err)
7072 		goto out1;
7073 
7074 	err = ext4_fc_init_dentry_cache();
7075 	if (err)
7076 		goto out05;
7077 
7078 	register_as_ext3();
7079 	register_as_ext2();
7080 	err = register_filesystem(&ext4_fs_type);
7081 	if (err)
7082 		goto out;
7083 
7084 	return 0;
7085 out:
7086 	unregister_as_ext2();
7087 	unregister_as_ext3();
7088 	ext4_fc_destroy_dentry_cache();
7089 out05:
7090 	destroy_inodecache();
7091 out1:
7092 	ext4_exit_mballoc();
7093 out2:
7094 	ext4_exit_sysfs();
7095 out3:
7096 	ext4_exit_system_zone();
7097 out4:
7098 	ext4_exit_pageio();
7099 out5:
7100 	ext4_exit_post_read_processing();
7101 out6:
7102 	ext4_exit_pending();
7103 out7:
7104 	ext4_exit_es();
7105 
7106 	return err;
7107 }
7108 
7109 static void __exit ext4_exit_fs(void)
7110 {
7111 	ext4_destroy_lazyinit_thread();
7112 	unregister_as_ext2();
7113 	unregister_as_ext3();
7114 	unregister_filesystem(&ext4_fs_type);
7115 	ext4_fc_destroy_dentry_cache();
7116 	destroy_inodecache();
7117 	ext4_exit_mballoc();
7118 	ext4_exit_sysfs();
7119 	ext4_exit_system_zone();
7120 	ext4_exit_pageio();
7121 	ext4_exit_post_read_processing();
7122 	ext4_exit_es();
7123 	ext4_exit_pending();
7124 }
7125 
7126 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7127 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7128 MODULE_LICENSE("GPL");
7129 MODULE_SOFTDEP("pre: crc32c");
7130 module_init(ext4_init_fs)
7131 module_exit(ext4_exit_fs)
7132