xref: /linux/fs/ext4/super.c (revision b9b01a5625b5a9e9d96d14d4a813a54e8a124f4b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static 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, blk_opf_t 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, blk_opf_t 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, blk_opf_t 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, blk_opf_t op_flags, bool wait)
207 {
208 	lock_buffer(bh);
209 	if (!wait) {
210 		ext4_read_bh_nowait(bh, op_flags, NULL);
211 		return 0;
212 	}
213 	return ext4_read_bh(bh, op_flags, NULL);
214 }
215 
216 /*
217  * This works like __bread_gfp() except it uses ERR_PTR for error
218  * returns.  Currently with sb_bread it's impossible to distinguish
219  * between ENOMEM and EIO situations (since both result in a NULL
220  * return.
221  */
222 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
223 					       sector_t block,
224 					       blk_opf_t op_flags, gfp_t gfp)
225 {
226 	struct buffer_head *bh;
227 	int ret;
228 
229 	bh = sb_getblk_gfp(sb, block, gfp);
230 	if (bh == NULL)
231 		return ERR_PTR(-ENOMEM);
232 	if (ext4_buffer_uptodate(bh))
233 		return bh;
234 
235 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
236 	if (ret) {
237 		put_bh(bh);
238 		return ERR_PTR(ret);
239 	}
240 	return bh;
241 }
242 
243 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
244 				   blk_opf_t op_flags)
245 {
246 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
247 }
248 
249 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
250 					    sector_t block)
251 {
252 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
253 }
254 
255 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
256 {
257 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
258 
259 	if (likely(bh)) {
260 		if (trylock_buffer(bh))
261 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
262 		brelse(bh);
263 	}
264 }
265 
266 static int ext4_verify_csum_type(struct super_block *sb,
267 				 struct ext4_super_block *es)
268 {
269 	if (!ext4_has_feature_metadata_csum(sb))
270 		return 1;
271 
272 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
273 }
274 
275 __le32 ext4_superblock_csum(struct super_block *sb,
276 			    struct ext4_super_block *es)
277 {
278 	struct ext4_sb_info *sbi = EXT4_SB(sb);
279 	int offset = offsetof(struct ext4_super_block, s_checksum);
280 	__u32 csum;
281 
282 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
283 
284 	return cpu_to_le32(csum);
285 }
286 
287 static int ext4_superblock_csum_verify(struct super_block *sb,
288 				       struct ext4_super_block *es)
289 {
290 	if (!ext4_has_metadata_csum(sb))
291 		return 1;
292 
293 	return es->s_checksum == ext4_superblock_csum(sb, es);
294 }
295 
296 void ext4_superblock_csum_set(struct super_block *sb)
297 {
298 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
299 
300 	if (!ext4_has_metadata_csum(sb))
301 		return;
302 
303 	es->s_checksum = ext4_superblock_csum(sb, es);
304 }
305 
306 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
307 			       struct ext4_group_desc *bg)
308 {
309 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
310 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
311 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
312 }
313 
314 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
323 			      struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_table_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
328 }
329 
330 __u32 ext4_free_group_clusters(struct super_block *sb,
331 			       struct ext4_group_desc *bg)
332 {
333 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
336 }
337 
338 __u32 ext4_free_inodes_count(struct super_block *sb,
339 			      struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_used_dirs_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
352 }
353 
354 __u32 ext4_itable_unused_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_itable_unused_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
360 }
361 
362 void ext4_block_bitmap_set(struct super_block *sb,
363 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
364 {
365 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
366 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
367 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
368 }
369 
370 void ext4_inode_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_table_set(struct super_block *sb,
379 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_free_group_clusters_set(struct super_block *sb,
387 				  struct ext4_group_desc *bg, __u32 count)
388 {
389 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
392 }
393 
394 void ext4_free_inodes_set(struct super_block *sb,
395 			  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_used_dirs_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
408 }
409 
410 void ext4_itable_unused_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
416 }
417 
418 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
419 {
420 	now = clamp_val(now, 0, (1ull << 40) - 1);
421 
422 	*lo = cpu_to_le32(lower_32_bits(now));
423 	*hi = upper_32_bits(now);
424 }
425 
426 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
427 {
428 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
429 }
430 #define ext4_update_tstamp(es, tstamp) \
431 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
432 			     ktime_get_real_seconds())
433 #define ext4_get_tstamp(es, tstamp) \
434 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
435 
436 /*
437  * The del_gendisk() function uninitializes the disk-specific data
438  * structures, including the bdi structure, without telling anyone
439  * else.  Once this happens, any attempt to call mark_buffer_dirty()
440  * (for example, by ext4_commit_super), will cause a kernel OOPS.
441  * This is a kludge to prevent these oops until we can put in a proper
442  * hook in del_gendisk() to inform the VFS and file system layers.
443  */
444 static int block_device_ejected(struct super_block *sb)
445 {
446 	struct inode *bd_inode = sb->s_bdev->bd_inode;
447 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
448 
449 	return bdi->dev == NULL;
450 }
451 
452 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
453 {
454 	struct super_block		*sb = journal->j_private;
455 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
456 	int				error = is_journal_aborted(journal);
457 	struct ext4_journal_cb_entry	*jce;
458 
459 	BUG_ON(txn->t_state == T_FINISHED);
460 
461 	ext4_process_freed_data(sb, txn->t_tid);
462 
463 	spin_lock(&sbi->s_md_lock);
464 	while (!list_empty(&txn->t_private_list)) {
465 		jce = list_entry(txn->t_private_list.next,
466 				 struct ext4_journal_cb_entry, jce_list);
467 		list_del_init(&jce->jce_list);
468 		spin_unlock(&sbi->s_md_lock);
469 		jce->jce_func(sb, jce, error);
470 		spin_lock(&sbi->s_md_lock);
471 	}
472 	spin_unlock(&sbi->s_md_lock);
473 }
474 
475 /*
476  * This writepage callback for write_cache_pages()
477  * takes care of a few cases after page cleaning.
478  *
479  * write_cache_pages() already checks for dirty pages
480  * and calls clear_page_dirty_for_io(), which we want,
481  * to write protect the pages.
482  *
483  * However, we may have to redirty a page (see below.)
484  */
485 static int ext4_journalled_writepage_callback(struct page *page,
486 					      struct writeback_control *wbc,
487 					      void *data)
488 {
489 	transaction_t *transaction = (transaction_t *) data;
490 	struct buffer_head *bh, *head;
491 	struct journal_head *jh;
492 
493 	bh = head = page_buffers(page);
494 	do {
495 		/*
496 		 * We have to redirty a page in these cases:
497 		 * 1) If buffer is dirty, it means the page was dirty because it
498 		 * contains a buffer that needs checkpointing. So the dirty bit
499 		 * needs to be preserved so that checkpointing writes the buffer
500 		 * properly.
501 		 * 2) If buffer is not part of the committing transaction
502 		 * (we may have just accidentally come across this buffer because
503 		 * inode range tracking is not exact) or if the currently running
504 		 * transaction already contains this buffer as well, dirty bit
505 		 * needs to be preserved so that the buffer gets writeprotected
506 		 * properly on running transaction's commit.
507 		 */
508 		jh = bh2jh(bh);
509 		if (buffer_dirty(bh) ||
510 		    (jh && (jh->b_transaction != transaction ||
511 			    jh->b_next_transaction))) {
512 			redirty_page_for_writepage(wbc, page);
513 			goto out;
514 		}
515 	} while ((bh = bh->b_this_page) != head);
516 
517 out:
518 	return AOP_WRITEPAGE_ACTIVATE;
519 }
520 
521 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
522 {
523 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
524 	struct writeback_control wbc = {
525 		.sync_mode =  WB_SYNC_ALL,
526 		.nr_to_write = LONG_MAX,
527 		.range_start = jinode->i_dirty_start,
528 		.range_end = jinode->i_dirty_end,
529         };
530 
531 	return write_cache_pages(mapping, &wbc,
532 				 ext4_journalled_writepage_callback,
533 				 jinode->i_transaction);
534 }
535 
536 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
537 {
538 	int ret;
539 
540 	if (ext4_should_journal_data(jinode->i_vfs_inode))
541 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
542 	else
543 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
544 
545 	return ret;
546 }
547 
548 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
549 {
550 	int ret = 0;
551 
552 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
553 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
554 
555 	return ret;
556 }
557 
558 static bool system_going_down(void)
559 {
560 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
561 		|| system_state == SYSTEM_RESTART;
562 }
563 
564 struct ext4_err_translation {
565 	int code;
566 	int errno;
567 };
568 
569 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
570 
571 static struct ext4_err_translation err_translation[] = {
572 	EXT4_ERR_TRANSLATE(EIO),
573 	EXT4_ERR_TRANSLATE(ENOMEM),
574 	EXT4_ERR_TRANSLATE(EFSBADCRC),
575 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
576 	EXT4_ERR_TRANSLATE(ENOSPC),
577 	EXT4_ERR_TRANSLATE(ENOKEY),
578 	EXT4_ERR_TRANSLATE(EROFS),
579 	EXT4_ERR_TRANSLATE(EFBIG),
580 	EXT4_ERR_TRANSLATE(EEXIST),
581 	EXT4_ERR_TRANSLATE(ERANGE),
582 	EXT4_ERR_TRANSLATE(EOVERFLOW),
583 	EXT4_ERR_TRANSLATE(EBUSY),
584 	EXT4_ERR_TRANSLATE(ENOTDIR),
585 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
586 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
587 	EXT4_ERR_TRANSLATE(EFAULT),
588 };
589 
590 static int ext4_errno_to_code(int errno)
591 {
592 	int i;
593 
594 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
595 		if (err_translation[i].errno == errno)
596 			return err_translation[i].code;
597 	return EXT4_ERR_UNKNOWN;
598 }
599 
600 static void save_error_info(struct super_block *sb, int error,
601 			    __u32 ino, __u64 block,
602 			    const char *func, unsigned int line)
603 {
604 	struct ext4_sb_info *sbi = EXT4_SB(sb);
605 
606 	/* We default to EFSCORRUPTED error... */
607 	if (error == 0)
608 		error = EFSCORRUPTED;
609 
610 	spin_lock(&sbi->s_error_lock);
611 	sbi->s_add_error_count++;
612 	sbi->s_last_error_code = error;
613 	sbi->s_last_error_line = line;
614 	sbi->s_last_error_ino = ino;
615 	sbi->s_last_error_block = block;
616 	sbi->s_last_error_func = func;
617 	sbi->s_last_error_time = ktime_get_real_seconds();
618 	if (!sbi->s_first_error_time) {
619 		sbi->s_first_error_code = error;
620 		sbi->s_first_error_line = line;
621 		sbi->s_first_error_ino = ino;
622 		sbi->s_first_error_block = block;
623 		sbi->s_first_error_func = func;
624 		sbi->s_first_error_time = sbi->s_last_error_time;
625 	}
626 	spin_unlock(&sbi->s_error_lock);
627 }
628 
629 /* Deal with the reporting of failure conditions on a filesystem such as
630  * inconsistencies detected or read IO failures.
631  *
632  * On ext2, we can store the error state of the filesystem in the
633  * superblock.  That is not possible on ext4, because we may have other
634  * write ordering constraints on the superblock which prevent us from
635  * writing it out straight away; and given that the journal is about to
636  * be aborted, we can't rely on the current, or future, transactions to
637  * write out the superblock safely.
638  *
639  * We'll just use the jbd2_journal_abort() error code to record an error in
640  * the journal instead.  On recovery, the journal will complain about
641  * that error until we've noted it down and cleared it.
642  *
643  * If force_ro is set, we unconditionally force the filesystem into an
644  * ABORT|READONLY state, unless the error response on the fs has been set to
645  * panic in which case we take the easy way out and panic immediately. This is
646  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
647  * at a critical moment in log management.
648  */
649 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
650 			      __u32 ino, __u64 block,
651 			      const char *func, unsigned int line)
652 {
653 	journal_t *journal = EXT4_SB(sb)->s_journal;
654 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
655 
656 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
657 	if (test_opt(sb, WARN_ON_ERROR))
658 		WARN_ON_ONCE(1);
659 
660 	if (!continue_fs && !sb_rdonly(sb)) {
661 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
662 		if (journal)
663 			jbd2_journal_abort(journal, -EIO);
664 	}
665 
666 	if (!bdev_read_only(sb->s_bdev)) {
667 		save_error_info(sb, error, ino, block, func, line);
668 		/*
669 		 * In case the fs should keep running, we need to writeout
670 		 * superblock through the journal. Due to lock ordering
671 		 * constraints, it may not be safe to do it right here so we
672 		 * defer superblock flushing to a workqueue.
673 		 */
674 		if (continue_fs && journal)
675 			schedule_work(&EXT4_SB(sb)->s_error_work);
676 		else
677 			ext4_commit_super(sb);
678 	}
679 
680 	/*
681 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
682 	 * could panic during 'reboot -f' as the underlying device got already
683 	 * disabled.
684 	 */
685 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
686 		panic("EXT4-fs (device %s): panic forced after error\n",
687 			sb->s_id);
688 	}
689 
690 	if (sb_rdonly(sb) || continue_fs)
691 		return;
692 
693 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
694 	/*
695 	 * Make sure updated value of ->s_mount_flags will be visible before
696 	 * ->s_flags update
697 	 */
698 	smp_wmb();
699 	sb->s_flags |= SB_RDONLY;
700 }
701 
702 static void flush_stashed_error_work(struct work_struct *work)
703 {
704 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
705 						s_error_work);
706 	journal_t *journal = sbi->s_journal;
707 	handle_t *handle;
708 
709 	/*
710 	 * If the journal is still running, we have to write out superblock
711 	 * through the journal to avoid collisions of other journalled sb
712 	 * updates.
713 	 *
714 	 * We use directly jbd2 functions here to avoid recursing back into
715 	 * ext4 error handling code during handling of previous errors.
716 	 */
717 	if (!sb_rdonly(sbi->s_sb) && journal) {
718 		struct buffer_head *sbh = sbi->s_sbh;
719 		handle = jbd2_journal_start(journal, 1);
720 		if (IS_ERR(handle))
721 			goto write_directly;
722 		if (jbd2_journal_get_write_access(handle, sbh)) {
723 			jbd2_journal_stop(handle);
724 			goto write_directly;
725 		}
726 		ext4_update_super(sbi->s_sb);
727 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
728 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
729 				 "superblock detected");
730 			clear_buffer_write_io_error(sbh);
731 			set_buffer_uptodate(sbh);
732 		}
733 
734 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
735 			jbd2_journal_stop(handle);
736 			goto write_directly;
737 		}
738 		jbd2_journal_stop(handle);
739 		ext4_notify_error_sysfs(sbi);
740 		return;
741 	}
742 write_directly:
743 	/*
744 	 * Write through journal failed. Write sb directly to get error info
745 	 * out and hope for the best.
746 	 */
747 	ext4_commit_super(sbi->s_sb);
748 	ext4_notify_error_sysfs(sbi);
749 }
750 
751 #define ext4_error_ratelimit(sb)					\
752 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
753 			     "EXT4-fs error")
754 
755 void __ext4_error(struct super_block *sb, const char *function,
756 		  unsigned int line, bool force_ro, int error, __u64 block,
757 		  const char *fmt, ...)
758 {
759 	struct va_format vaf;
760 	va_list args;
761 
762 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
763 		return;
764 
765 	trace_ext4_error(sb, function, line);
766 	if (ext4_error_ratelimit(sb)) {
767 		va_start(args, fmt);
768 		vaf.fmt = fmt;
769 		vaf.va = &args;
770 		printk(KERN_CRIT
771 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
772 		       sb->s_id, function, line, current->comm, &vaf);
773 		va_end(args);
774 	}
775 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
776 
777 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
778 }
779 
780 void __ext4_error_inode(struct inode *inode, const char *function,
781 			unsigned int line, ext4_fsblk_t block, int error,
782 			const char *fmt, ...)
783 {
784 	va_list args;
785 	struct va_format vaf;
786 
787 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
788 		return;
789 
790 	trace_ext4_error(inode->i_sb, function, line);
791 	if (ext4_error_ratelimit(inode->i_sb)) {
792 		va_start(args, fmt);
793 		vaf.fmt = fmt;
794 		vaf.va = &args;
795 		if (block)
796 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
797 			       "inode #%lu: block %llu: comm %s: %pV\n",
798 			       inode->i_sb->s_id, function, line, inode->i_ino,
799 			       block, current->comm, &vaf);
800 		else
801 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
802 			       "inode #%lu: comm %s: %pV\n",
803 			       inode->i_sb->s_id, function, line, inode->i_ino,
804 			       current->comm, &vaf);
805 		va_end(args);
806 	}
807 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
808 
809 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
810 			  function, line);
811 }
812 
813 void __ext4_error_file(struct file *file, const char *function,
814 		       unsigned int line, ext4_fsblk_t block,
815 		       const char *fmt, ...)
816 {
817 	va_list args;
818 	struct va_format vaf;
819 	struct inode *inode = file_inode(file);
820 	char pathname[80], *path;
821 
822 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
823 		return;
824 
825 	trace_ext4_error(inode->i_sb, function, line);
826 	if (ext4_error_ratelimit(inode->i_sb)) {
827 		path = file_path(file, pathname, sizeof(pathname));
828 		if (IS_ERR(path))
829 			path = "(unknown)";
830 		va_start(args, fmt);
831 		vaf.fmt = fmt;
832 		vaf.va = &args;
833 		if (block)
834 			printk(KERN_CRIT
835 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
836 			       "block %llu: comm %s: path %s: %pV\n",
837 			       inode->i_sb->s_id, function, line, inode->i_ino,
838 			       block, current->comm, path, &vaf);
839 		else
840 			printk(KERN_CRIT
841 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
842 			       "comm %s: path %s: %pV\n",
843 			       inode->i_sb->s_id, function, line, inode->i_ino,
844 			       current->comm, path, &vaf);
845 		va_end(args);
846 	}
847 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
848 
849 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
850 			  function, line);
851 }
852 
853 const char *ext4_decode_error(struct super_block *sb, int errno,
854 			      char nbuf[16])
855 {
856 	char *errstr = NULL;
857 
858 	switch (errno) {
859 	case -EFSCORRUPTED:
860 		errstr = "Corrupt filesystem";
861 		break;
862 	case -EFSBADCRC:
863 		errstr = "Filesystem failed CRC";
864 		break;
865 	case -EIO:
866 		errstr = "IO failure";
867 		break;
868 	case -ENOMEM:
869 		errstr = "Out of memory";
870 		break;
871 	case -EROFS:
872 		if (!sb || (EXT4_SB(sb)->s_journal &&
873 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
874 			errstr = "Journal has aborted";
875 		else
876 			errstr = "Readonly filesystem";
877 		break;
878 	default:
879 		/* If the caller passed in an extra buffer for unknown
880 		 * errors, textualise them now.  Else we just return
881 		 * NULL. */
882 		if (nbuf) {
883 			/* Check for truncated error codes... */
884 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
885 				errstr = nbuf;
886 		}
887 		break;
888 	}
889 
890 	return errstr;
891 }
892 
893 /* __ext4_std_error decodes expected errors from journaling functions
894  * automatically and invokes the appropriate error response.  */
895 
896 void __ext4_std_error(struct super_block *sb, const char *function,
897 		      unsigned int line, int errno)
898 {
899 	char nbuf[16];
900 	const char *errstr;
901 
902 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
903 		return;
904 
905 	/* Special case: if the error is EROFS, and we're not already
906 	 * inside a transaction, then there's really no point in logging
907 	 * an error. */
908 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
909 		return;
910 
911 	if (ext4_error_ratelimit(sb)) {
912 		errstr = ext4_decode_error(sb, errno, nbuf);
913 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
914 		       sb->s_id, function, line, errstr);
915 	}
916 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
917 
918 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
919 }
920 
921 void __ext4_msg(struct super_block *sb,
922 		const char *prefix, const char *fmt, ...)
923 {
924 	struct va_format vaf;
925 	va_list args;
926 
927 	if (sb) {
928 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
929 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
930 				  "EXT4-fs"))
931 			return;
932 	}
933 
934 	va_start(args, fmt);
935 	vaf.fmt = fmt;
936 	vaf.va = &args;
937 	if (sb)
938 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
939 	else
940 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
941 	va_end(args);
942 }
943 
944 static int ext4_warning_ratelimit(struct super_block *sb)
945 {
946 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
947 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
948 			    "EXT4-fs warning");
949 }
950 
951 void __ext4_warning(struct super_block *sb, const char *function,
952 		    unsigned int line, const char *fmt, ...)
953 {
954 	struct va_format vaf;
955 	va_list args;
956 
957 	if (!ext4_warning_ratelimit(sb))
958 		return;
959 
960 	va_start(args, fmt);
961 	vaf.fmt = fmt;
962 	vaf.va = &args;
963 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
964 	       sb->s_id, function, line, &vaf);
965 	va_end(args);
966 }
967 
968 void __ext4_warning_inode(const struct inode *inode, const char *function,
969 			  unsigned int line, const char *fmt, ...)
970 {
971 	struct va_format vaf;
972 	va_list args;
973 
974 	if (!ext4_warning_ratelimit(inode->i_sb))
975 		return;
976 
977 	va_start(args, fmt);
978 	vaf.fmt = fmt;
979 	vaf.va = &args;
980 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
981 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
982 	       function, line, inode->i_ino, current->comm, &vaf);
983 	va_end(args);
984 }
985 
986 void __ext4_grp_locked_error(const char *function, unsigned int line,
987 			     struct super_block *sb, ext4_group_t grp,
988 			     unsigned long ino, ext4_fsblk_t block,
989 			     const char *fmt, ...)
990 __releases(bitlock)
991 __acquires(bitlock)
992 {
993 	struct va_format vaf;
994 	va_list args;
995 
996 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
997 		return;
998 
999 	trace_ext4_error(sb, function, line);
1000 	if (ext4_error_ratelimit(sb)) {
1001 		va_start(args, fmt);
1002 		vaf.fmt = fmt;
1003 		vaf.va = &args;
1004 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1005 		       sb->s_id, function, line, grp);
1006 		if (ino)
1007 			printk(KERN_CONT "inode %lu: ", ino);
1008 		if (block)
1009 			printk(KERN_CONT "block %llu:",
1010 			       (unsigned long long) block);
1011 		printk(KERN_CONT "%pV\n", &vaf);
1012 		va_end(args);
1013 	}
1014 
1015 	if (test_opt(sb, ERRORS_CONT)) {
1016 		if (test_opt(sb, WARN_ON_ERROR))
1017 			WARN_ON_ONCE(1);
1018 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1019 		if (!bdev_read_only(sb->s_bdev)) {
1020 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1021 					line);
1022 			schedule_work(&EXT4_SB(sb)->s_error_work);
1023 		}
1024 		return;
1025 	}
1026 	ext4_unlock_group(sb, grp);
1027 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1028 	/*
1029 	 * We only get here in the ERRORS_RO case; relocking the group
1030 	 * may be dangerous, but nothing bad will happen since the
1031 	 * filesystem will have already been marked read/only and the
1032 	 * journal has been aborted.  We return 1 as a hint to callers
1033 	 * who might what to use the return value from
1034 	 * ext4_grp_locked_error() to distinguish between the
1035 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1036 	 * aggressively from the ext4 function in question, with a
1037 	 * more appropriate error code.
1038 	 */
1039 	ext4_lock_group(sb, grp);
1040 	return;
1041 }
1042 
1043 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1044 				     ext4_group_t group,
1045 				     unsigned int flags)
1046 {
1047 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1048 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1049 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1050 	int ret;
1051 
1052 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1053 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1054 					    &grp->bb_state);
1055 		if (!ret)
1056 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1057 					   grp->bb_free);
1058 	}
1059 
1060 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1061 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1062 					    &grp->bb_state);
1063 		if (!ret && gdp) {
1064 			int count;
1065 
1066 			count = ext4_free_inodes_count(sb, gdp);
1067 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1068 					   count);
1069 		}
1070 	}
1071 }
1072 
1073 void ext4_update_dynamic_rev(struct super_block *sb)
1074 {
1075 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1076 
1077 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1078 		return;
1079 
1080 	ext4_warning(sb,
1081 		     "updating to rev %d because of new feature flag, "
1082 		     "running e2fsck is recommended",
1083 		     EXT4_DYNAMIC_REV);
1084 
1085 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1086 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1087 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1088 	/* leave es->s_feature_*compat flags alone */
1089 	/* es->s_uuid will be set by e2fsck if empty */
1090 
1091 	/*
1092 	 * The rest of the superblock fields should be zero, and if not it
1093 	 * means they are likely already in use, so leave them alone.  We
1094 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1095 	 */
1096 }
1097 
1098 /*
1099  * Open the external journal device
1100  */
1101 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1102 {
1103 	struct block_device *bdev;
1104 
1105 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1106 	if (IS_ERR(bdev))
1107 		goto fail;
1108 	return bdev;
1109 
1110 fail:
1111 	ext4_msg(sb, KERN_ERR,
1112 		 "failed to open journal device unknown-block(%u,%u) %ld",
1113 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1114 	return NULL;
1115 }
1116 
1117 /*
1118  * Release the journal device
1119  */
1120 static void ext4_blkdev_put(struct block_device *bdev)
1121 {
1122 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1123 }
1124 
1125 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1126 {
1127 	struct block_device *bdev;
1128 	bdev = sbi->s_journal_bdev;
1129 	if (bdev) {
1130 		ext4_blkdev_put(bdev);
1131 		sbi->s_journal_bdev = NULL;
1132 	}
1133 }
1134 
1135 static inline struct inode *orphan_list_entry(struct list_head *l)
1136 {
1137 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1138 }
1139 
1140 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1141 {
1142 	struct list_head *l;
1143 
1144 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1145 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1146 
1147 	printk(KERN_ERR "sb_info orphan list:\n");
1148 	list_for_each(l, &sbi->s_orphan) {
1149 		struct inode *inode = orphan_list_entry(l);
1150 		printk(KERN_ERR "  "
1151 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1152 		       inode->i_sb->s_id, inode->i_ino, inode,
1153 		       inode->i_mode, inode->i_nlink,
1154 		       NEXT_ORPHAN(inode));
1155 	}
1156 }
1157 
1158 #ifdef CONFIG_QUOTA
1159 static int ext4_quota_off(struct super_block *sb, int type);
1160 
1161 static inline void ext4_quota_off_umount(struct super_block *sb)
1162 {
1163 	int type;
1164 
1165 	/* Use our quota_off function to clear inode flags etc. */
1166 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1167 		ext4_quota_off(sb, type);
1168 }
1169 
1170 /*
1171  * This is a helper function which is used in the mount/remount
1172  * codepaths (which holds s_umount) to fetch the quota file name.
1173  */
1174 static inline char *get_qf_name(struct super_block *sb,
1175 				struct ext4_sb_info *sbi,
1176 				int type)
1177 {
1178 	return rcu_dereference_protected(sbi->s_qf_names[type],
1179 					 lockdep_is_held(&sb->s_umount));
1180 }
1181 #else
1182 static inline void ext4_quota_off_umount(struct super_block *sb)
1183 {
1184 }
1185 #endif
1186 
1187 static void ext4_put_super(struct super_block *sb)
1188 {
1189 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1190 	struct ext4_super_block *es = sbi->s_es;
1191 	struct buffer_head **group_desc;
1192 	struct flex_groups **flex_groups;
1193 	int aborted = 0;
1194 	int i, err;
1195 
1196 	/*
1197 	 * Unregister sysfs before destroying jbd2 journal.
1198 	 * Since we could still access attr_journal_task attribute via sysfs
1199 	 * path which could have sbi->s_journal->j_task as NULL
1200 	 * Unregister sysfs before flush sbi->s_error_work.
1201 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1202 	 * read metadata verify failed then will queue error work.
1203 	 * flush_stashed_error_work will call start_this_handle may trigger
1204 	 * BUG_ON.
1205 	 */
1206 	ext4_unregister_sysfs(sb);
1207 
1208 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1209 		ext4_msg(sb, KERN_INFO, "unmounting filesystem.");
1210 
1211 	ext4_unregister_li_request(sb);
1212 	ext4_quota_off_umount(sb);
1213 
1214 	flush_work(&sbi->s_error_work);
1215 	destroy_workqueue(sbi->rsv_conversion_wq);
1216 	ext4_release_orphan_info(sb);
1217 
1218 	if (sbi->s_journal) {
1219 		aborted = is_journal_aborted(sbi->s_journal);
1220 		err = jbd2_journal_destroy(sbi->s_journal);
1221 		sbi->s_journal = NULL;
1222 		if ((err < 0) && !aborted) {
1223 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1224 		}
1225 	}
1226 
1227 	ext4_es_unregister_shrinker(sbi);
1228 	del_timer_sync(&sbi->s_err_report);
1229 	ext4_release_system_zone(sb);
1230 	ext4_mb_release(sb);
1231 	ext4_ext_release(sb);
1232 
1233 	if (!sb_rdonly(sb) && !aborted) {
1234 		ext4_clear_feature_journal_needs_recovery(sb);
1235 		ext4_clear_feature_orphan_present(sb);
1236 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1237 	}
1238 	if (!sb_rdonly(sb))
1239 		ext4_commit_super(sb);
1240 
1241 	rcu_read_lock();
1242 	group_desc = rcu_dereference(sbi->s_group_desc);
1243 	for (i = 0; i < sbi->s_gdb_count; i++)
1244 		brelse(group_desc[i]);
1245 	kvfree(group_desc);
1246 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1247 	if (flex_groups) {
1248 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1249 			kvfree(flex_groups[i]);
1250 		kvfree(flex_groups);
1251 	}
1252 	rcu_read_unlock();
1253 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1254 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1255 	percpu_counter_destroy(&sbi->s_dirs_counter);
1256 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1257 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1258 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1259 #ifdef CONFIG_QUOTA
1260 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1261 		kfree(get_qf_name(sb, sbi, i));
1262 #endif
1263 
1264 	/* Debugging code just in case the in-memory inode orphan list
1265 	 * isn't empty.  The on-disk one can be non-empty if we've
1266 	 * detected an error and taken the fs readonly, but the
1267 	 * in-memory list had better be clean by this point. */
1268 	if (!list_empty(&sbi->s_orphan))
1269 		dump_orphan_list(sb, sbi);
1270 	ASSERT(list_empty(&sbi->s_orphan));
1271 
1272 	sync_blockdev(sb->s_bdev);
1273 	invalidate_bdev(sb->s_bdev);
1274 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1275 		/*
1276 		 * Invalidate the journal device's buffers.  We don't want them
1277 		 * floating about in memory - the physical journal device may
1278 		 * hotswapped, and it breaks the `ro-after' testing code.
1279 		 */
1280 		sync_blockdev(sbi->s_journal_bdev);
1281 		invalidate_bdev(sbi->s_journal_bdev);
1282 		ext4_blkdev_remove(sbi);
1283 	}
1284 
1285 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1286 	sbi->s_ea_inode_cache = NULL;
1287 
1288 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1289 	sbi->s_ea_block_cache = NULL;
1290 
1291 	ext4_stop_mmpd(sbi);
1292 
1293 	brelse(sbi->s_sbh);
1294 	sb->s_fs_info = NULL;
1295 	/*
1296 	 * Now that we are completely done shutting down the
1297 	 * superblock, we need to actually destroy the kobject.
1298 	 */
1299 	kobject_put(&sbi->s_kobj);
1300 	wait_for_completion(&sbi->s_kobj_unregister);
1301 	if (sbi->s_chksum_driver)
1302 		crypto_free_shash(sbi->s_chksum_driver);
1303 	kfree(sbi->s_blockgroup_lock);
1304 	fs_put_dax(sbi->s_daxdev, NULL);
1305 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1306 #if IS_ENABLED(CONFIG_UNICODE)
1307 	utf8_unload(sb->s_encoding);
1308 #endif
1309 	kfree(sbi);
1310 }
1311 
1312 static struct kmem_cache *ext4_inode_cachep;
1313 
1314 /*
1315  * Called inside transaction, so use GFP_NOFS
1316  */
1317 static struct inode *ext4_alloc_inode(struct super_block *sb)
1318 {
1319 	struct ext4_inode_info *ei;
1320 
1321 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1322 	if (!ei)
1323 		return NULL;
1324 
1325 	inode_set_iversion(&ei->vfs_inode, 1);
1326 	spin_lock_init(&ei->i_raw_lock);
1327 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1328 	atomic_set(&ei->i_prealloc_active, 0);
1329 	spin_lock_init(&ei->i_prealloc_lock);
1330 	ext4_es_init_tree(&ei->i_es_tree);
1331 	rwlock_init(&ei->i_es_lock);
1332 	INIT_LIST_HEAD(&ei->i_es_list);
1333 	ei->i_es_all_nr = 0;
1334 	ei->i_es_shk_nr = 0;
1335 	ei->i_es_shrink_lblk = 0;
1336 	ei->i_reserved_data_blocks = 0;
1337 	spin_lock_init(&(ei->i_block_reservation_lock));
1338 	ext4_init_pending_tree(&ei->i_pending_tree);
1339 #ifdef CONFIG_QUOTA
1340 	ei->i_reserved_quota = 0;
1341 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1342 #endif
1343 	ei->jinode = NULL;
1344 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1345 	spin_lock_init(&ei->i_completed_io_lock);
1346 	ei->i_sync_tid = 0;
1347 	ei->i_datasync_tid = 0;
1348 	atomic_set(&ei->i_unwritten, 0);
1349 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1350 	ext4_fc_init_inode(&ei->vfs_inode);
1351 	mutex_init(&ei->i_fc_lock);
1352 	return &ei->vfs_inode;
1353 }
1354 
1355 static int ext4_drop_inode(struct inode *inode)
1356 {
1357 	int drop = generic_drop_inode(inode);
1358 
1359 	if (!drop)
1360 		drop = fscrypt_drop_inode(inode);
1361 
1362 	trace_ext4_drop_inode(inode, drop);
1363 	return drop;
1364 }
1365 
1366 static void ext4_free_in_core_inode(struct inode *inode)
1367 {
1368 	fscrypt_free_inode(inode);
1369 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1370 		pr_warn("%s: inode %ld still in fc list",
1371 			__func__, inode->i_ino);
1372 	}
1373 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1374 }
1375 
1376 static void ext4_destroy_inode(struct inode *inode)
1377 {
1378 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1379 		ext4_msg(inode->i_sb, KERN_ERR,
1380 			 "Inode %lu (%p): orphan list check failed!",
1381 			 inode->i_ino, EXT4_I(inode));
1382 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1383 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1384 				true);
1385 		dump_stack();
1386 	}
1387 
1388 	if (EXT4_I(inode)->i_reserved_data_blocks)
1389 		ext4_msg(inode->i_sb, KERN_ERR,
1390 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1391 			 inode->i_ino, EXT4_I(inode),
1392 			 EXT4_I(inode)->i_reserved_data_blocks);
1393 }
1394 
1395 static void init_once(void *foo)
1396 {
1397 	struct ext4_inode_info *ei = foo;
1398 
1399 	INIT_LIST_HEAD(&ei->i_orphan);
1400 	init_rwsem(&ei->xattr_sem);
1401 	init_rwsem(&ei->i_data_sem);
1402 	inode_init_once(&ei->vfs_inode);
1403 	ext4_fc_init_inode(&ei->vfs_inode);
1404 }
1405 
1406 static int __init init_inodecache(void)
1407 {
1408 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1409 				sizeof(struct ext4_inode_info), 0,
1410 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1411 					SLAB_ACCOUNT),
1412 				offsetof(struct ext4_inode_info, i_data),
1413 				sizeof_field(struct ext4_inode_info, i_data),
1414 				init_once);
1415 	if (ext4_inode_cachep == NULL)
1416 		return -ENOMEM;
1417 	return 0;
1418 }
1419 
1420 static void destroy_inodecache(void)
1421 {
1422 	/*
1423 	 * Make sure all delayed rcu free inodes are flushed before we
1424 	 * destroy cache.
1425 	 */
1426 	rcu_barrier();
1427 	kmem_cache_destroy(ext4_inode_cachep);
1428 }
1429 
1430 void ext4_clear_inode(struct inode *inode)
1431 {
1432 	ext4_fc_del(inode);
1433 	invalidate_inode_buffers(inode);
1434 	clear_inode(inode);
1435 	ext4_discard_preallocations(inode, 0);
1436 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1437 	dquot_drop(inode);
1438 	if (EXT4_I(inode)->jinode) {
1439 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1440 					       EXT4_I(inode)->jinode);
1441 		jbd2_free_inode(EXT4_I(inode)->jinode);
1442 		EXT4_I(inode)->jinode = NULL;
1443 	}
1444 	fscrypt_put_encryption_info(inode);
1445 	fsverity_cleanup_inode(inode);
1446 }
1447 
1448 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1449 					u64 ino, u32 generation)
1450 {
1451 	struct inode *inode;
1452 
1453 	/*
1454 	 * Currently we don't know the generation for parent directory, so
1455 	 * a generation of 0 means "accept any"
1456 	 */
1457 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1458 	if (IS_ERR(inode))
1459 		return ERR_CAST(inode);
1460 	if (generation && inode->i_generation != generation) {
1461 		iput(inode);
1462 		return ERR_PTR(-ESTALE);
1463 	}
1464 
1465 	return inode;
1466 }
1467 
1468 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1469 					int fh_len, int fh_type)
1470 {
1471 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1472 				    ext4_nfs_get_inode);
1473 }
1474 
1475 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1476 					int fh_len, int fh_type)
1477 {
1478 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1479 				    ext4_nfs_get_inode);
1480 }
1481 
1482 static int ext4_nfs_commit_metadata(struct inode *inode)
1483 {
1484 	struct writeback_control wbc = {
1485 		.sync_mode = WB_SYNC_ALL
1486 	};
1487 
1488 	trace_ext4_nfs_commit_metadata(inode);
1489 	return ext4_write_inode(inode, &wbc);
1490 }
1491 
1492 #ifdef CONFIG_QUOTA
1493 static const char * const quotatypes[] = INITQFNAMES;
1494 #define QTYPE2NAME(t) (quotatypes[t])
1495 
1496 static int ext4_write_dquot(struct dquot *dquot);
1497 static int ext4_acquire_dquot(struct dquot *dquot);
1498 static int ext4_release_dquot(struct dquot *dquot);
1499 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1500 static int ext4_write_info(struct super_block *sb, int type);
1501 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1502 			 const struct path *path);
1503 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1504 			       size_t len, loff_t off);
1505 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1506 				const char *data, size_t len, loff_t off);
1507 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1508 			     unsigned int flags);
1509 
1510 static struct dquot **ext4_get_dquots(struct inode *inode)
1511 {
1512 	return EXT4_I(inode)->i_dquot;
1513 }
1514 
1515 static const struct dquot_operations ext4_quota_operations = {
1516 	.get_reserved_space	= ext4_get_reserved_space,
1517 	.write_dquot		= ext4_write_dquot,
1518 	.acquire_dquot		= ext4_acquire_dquot,
1519 	.release_dquot		= ext4_release_dquot,
1520 	.mark_dirty		= ext4_mark_dquot_dirty,
1521 	.write_info		= ext4_write_info,
1522 	.alloc_dquot		= dquot_alloc,
1523 	.destroy_dquot		= dquot_destroy,
1524 	.get_projid		= ext4_get_projid,
1525 	.get_inode_usage	= ext4_get_inode_usage,
1526 	.get_next_id		= dquot_get_next_id,
1527 };
1528 
1529 static const struct quotactl_ops ext4_qctl_operations = {
1530 	.quota_on	= ext4_quota_on,
1531 	.quota_off	= ext4_quota_off,
1532 	.quota_sync	= dquot_quota_sync,
1533 	.get_state	= dquot_get_state,
1534 	.set_info	= dquot_set_dqinfo,
1535 	.get_dqblk	= dquot_get_dqblk,
1536 	.set_dqblk	= dquot_set_dqblk,
1537 	.get_nextdqblk	= dquot_get_next_dqblk,
1538 };
1539 #endif
1540 
1541 static const struct super_operations ext4_sops = {
1542 	.alloc_inode	= ext4_alloc_inode,
1543 	.free_inode	= ext4_free_in_core_inode,
1544 	.destroy_inode	= ext4_destroy_inode,
1545 	.write_inode	= ext4_write_inode,
1546 	.dirty_inode	= ext4_dirty_inode,
1547 	.drop_inode	= ext4_drop_inode,
1548 	.evict_inode	= ext4_evict_inode,
1549 	.put_super	= ext4_put_super,
1550 	.sync_fs	= ext4_sync_fs,
1551 	.freeze_fs	= ext4_freeze,
1552 	.unfreeze_fs	= ext4_unfreeze,
1553 	.statfs		= ext4_statfs,
1554 	.show_options	= ext4_show_options,
1555 #ifdef CONFIG_QUOTA
1556 	.quota_read	= ext4_quota_read,
1557 	.quota_write	= ext4_quota_write,
1558 	.get_dquots	= ext4_get_dquots,
1559 #endif
1560 };
1561 
1562 static const struct export_operations ext4_export_ops = {
1563 	.fh_to_dentry = ext4_fh_to_dentry,
1564 	.fh_to_parent = ext4_fh_to_parent,
1565 	.get_parent = ext4_get_parent,
1566 	.commit_metadata = ext4_nfs_commit_metadata,
1567 };
1568 
1569 enum {
1570 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1571 	Opt_resgid, Opt_resuid, Opt_sb,
1572 	Opt_nouid32, Opt_debug, Opt_removed,
1573 	Opt_user_xattr, Opt_acl,
1574 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1575 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1576 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1577 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1578 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1579 	Opt_inlinecrypt,
1580 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1581 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1582 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1583 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1584 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1585 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1586 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1587 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1588 	Opt_dioread_nolock, Opt_dioread_lock,
1589 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1590 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1591 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1592 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1593 #ifdef CONFIG_EXT4_DEBUG
1594 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1595 #endif
1596 };
1597 
1598 static const struct constant_table ext4_param_errors[] = {
1599 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1600 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1601 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1602 	{}
1603 };
1604 
1605 static const struct constant_table ext4_param_data[] = {
1606 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1607 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1608 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1609 	{}
1610 };
1611 
1612 static const struct constant_table ext4_param_data_err[] = {
1613 	{"abort",	Opt_data_err_abort},
1614 	{"ignore",	Opt_data_err_ignore},
1615 	{}
1616 };
1617 
1618 static const struct constant_table ext4_param_jqfmt[] = {
1619 	{"vfsold",	QFMT_VFS_OLD},
1620 	{"vfsv0",	QFMT_VFS_V0},
1621 	{"vfsv1",	QFMT_VFS_V1},
1622 	{}
1623 };
1624 
1625 static const struct constant_table ext4_param_dax[] = {
1626 	{"always",	Opt_dax_always},
1627 	{"inode",	Opt_dax_inode},
1628 	{"never",	Opt_dax_never},
1629 	{}
1630 };
1631 
1632 /* String parameter that allows empty argument */
1633 #define fsparam_string_empty(NAME, OPT) \
1634 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1635 
1636 /*
1637  * Mount option specification
1638  * We don't use fsparam_flag_no because of the way we set the
1639  * options and the way we show them in _ext4_show_options(). To
1640  * keep the changes to a minimum, let's keep the negative options
1641  * separate for now.
1642  */
1643 static const struct fs_parameter_spec ext4_param_specs[] = {
1644 	fsparam_flag	("bsddf",		Opt_bsd_df),
1645 	fsparam_flag	("minixdf",		Opt_minix_df),
1646 	fsparam_flag	("grpid",		Opt_grpid),
1647 	fsparam_flag	("bsdgroups",		Opt_grpid),
1648 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1649 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1650 	fsparam_u32	("resgid",		Opt_resgid),
1651 	fsparam_u32	("resuid",		Opt_resuid),
1652 	fsparam_u32	("sb",			Opt_sb),
1653 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1654 	fsparam_flag	("nouid32",		Opt_nouid32),
1655 	fsparam_flag	("debug",		Opt_debug),
1656 	fsparam_flag	("oldalloc",		Opt_removed),
1657 	fsparam_flag	("orlov",		Opt_removed),
1658 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1659 	fsparam_flag	("acl",			Opt_acl),
1660 	fsparam_flag	("norecovery",		Opt_noload),
1661 	fsparam_flag	("noload",		Opt_noload),
1662 	fsparam_flag	("bh",			Opt_removed),
1663 	fsparam_flag	("nobh",		Opt_removed),
1664 	fsparam_u32	("commit",		Opt_commit),
1665 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1666 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1667 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1668 	fsparam_bdev	("journal_path",	Opt_journal_path),
1669 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1670 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1671 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1672 	fsparam_flag	("abort",		Opt_abort),
1673 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1674 	fsparam_enum	("data_err",		Opt_data_err,
1675 						ext4_param_data_err),
1676 	fsparam_string_empty
1677 			("usrjquota",		Opt_usrjquota),
1678 	fsparam_string_empty
1679 			("grpjquota",		Opt_grpjquota),
1680 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1681 	fsparam_flag	("grpquota",		Opt_grpquota),
1682 	fsparam_flag	("quota",		Opt_quota),
1683 	fsparam_flag	("noquota",		Opt_noquota),
1684 	fsparam_flag	("usrquota",		Opt_usrquota),
1685 	fsparam_flag	("prjquota",		Opt_prjquota),
1686 	fsparam_flag	("barrier",		Opt_barrier),
1687 	fsparam_u32	("barrier",		Opt_barrier),
1688 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1689 	fsparam_flag	("i_version",		Opt_removed),
1690 	fsparam_flag	("dax",			Opt_dax),
1691 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1692 	fsparam_u32	("stripe",		Opt_stripe),
1693 	fsparam_flag	("delalloc",		Opt_delalloc),
1694 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1695 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1696 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1697 	fsparam_u32	("debug_want_extra_isize",
1698 						Opt_debug_want_extra_isize),
1699 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1700 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1701 	fsparam_flag	("block_validity",	Opt_block_validity),
1702 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1703 	fsparam_u32	("inode_readahead_blks",
1704 						Opt_inode_readahead_blks),
1705 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1706 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1707 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1708 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1709 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1710 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1711 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1712 	fsparam_flag	("discard",		Opt_discard),
1713 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1714 	fsparam_u32	("init_itable",		Opt_init_itable),
1715 	fsparam_flag	("init_itable",		Opt_init_itable),
1716 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1717 #ifdef CONFIG_EXT4_DEBUG
1718 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1719 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1720 #endif
1721 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1722 	fsparam_flag	("test_dummy_encryption",
1723 						Opt_test_dummy_encryption),
1724 	fsparam_string	("test_dummy_encryption",
1725 						Opt_test_dummy_encryption),
1726 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1727 	fsparam_flag	("nombcache",		Opt_nombcache),
1728 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1729 	fsparam_flag	("prefetch_block_bitmaps",
1730 						Opt_removed),
1731 	fsparam_flag	("no_prefetch_block_bitmaps",
1732 						Opt_no_prefetch_block_bitmaps),
1733 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1734 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1735 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1736 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1737 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1738 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1739 	{}
1740 };
1741 
1742 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1743 
1744 #define MOPT_SET	0x0001
1745 #define MOPT_CLEAR	0x0002
1746 #define MOPT_NOSUPPORT	0x0004
1747 #define MOPT_EXPLICIT	0x0008
1748 #ifdef CONFIG_QUOTA
1749 #define MOPT_Q		0
1750 #define MOPT_QFMT	0x0010
1751 #else
1752 #define MOPT_Q		MOPT_NOSUPPORT
1753 #define MOPT_QFMT	MOPT_NOSUPPORT
1754 #endif
1755 #define MOPT_NO_EXT2	0x0020
1756 #define MOPT_NO_EXT3	0x0040
1757 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1758 #define MOPT_SKIP	0x0080
1759 #define	MOPT_2		0x0100
1760 
1761 static const struct mount_opts {
1762 	int	token;
1763 	int	mount_opt;
1764 	int	flags;
1765 } ext4_mount_opts[] = {
1766 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1767 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1768 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1769 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1770 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1771 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1772 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1773 	 MOPT_EXT4_ONLY | MOPT_SET},
1774 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1775 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1776 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1777 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1778 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1779 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1780 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1781 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1782 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1783 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1784 	{Opt_commit, 0, MOPT_NO_EXT2},
1785 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1786 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1787 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1788 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1789 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1790 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1791 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1792 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1793 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1794 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1795 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1796 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1797 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1798 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1799 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1800 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1801 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1802 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1803 	{Opt_data, 0, MOPT_NO_EXT2},
1804 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1805 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1806 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1807 #else
1808 	{Opt_acl, 0, MOPT_NOSUPPORT},
1809 #endif
1810 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1811 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1812 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1813 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1814 							MOPT_SET | MOPT_Q},
1815 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1816 							MOPT_SET | MOPT_Q},
1817 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1818 							MOPT_SET | MOPT_Q},
1819 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1820 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1821 							MOPT_CLEAR | MOPT_Q},
1822 	{Opt_usrjquota, 0, MOPT_Q},
1823 	{Opt_grpjquota, 0, MOPT_Q},
1824 	{Opt_jqfmt, 0, MOPT_QFMT},
1825 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1826 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1827 	 MOPT_SET},
1828 #ifdef CONFIG_EXT4_DEBUG
1829 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1830 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1831 #endif
1832 	{Opt_err, 0, 0}
1833 };
1834 
1835 #if IS_ENABLED(CONFIG_UNICODE)
1836 static const struct ext4_sb_encodings {
1837 	__u16 magic;
1838 	char *name;
1839 	unsigned int version;
1840 } ext4_sb_encoding_map[] = {
1841 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1842 };
1843 
1844 static const struct ext4_sb_encodings *
1845 ext4_sb_read_encoding(const struct ext4_super_block *es)
1846 {
1847 	__u16 magic = le16_to_cpu(es->s_encoding);
1848 	int i;
1849 
1850 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1851 		if (magic == ext4_sb_encoding_map[i].magic)
1852 			return &ext4_sb_encoding_map[i];
1853 
1854 	return NULL;
1855 }
1856 #endif
1857 
1858 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1859 #define EXT4_SPEC_JQFMT				(1 <<  1)
1860 #define EXT4_SPEC_DATAJ				(1 <<  2)
1861 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1862 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1863 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1864 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1865 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1866 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1867 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1868 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1869 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1870 #define EXT4_SPEC_s_stripe			(1 << 13)
1871 #define EXT4_SPEC_s_resuid			(1 << 14)
1872 #define EXT4_SPEC_s_resgid			(1 << 15)
1873 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1874 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1875 #define EXT4_SPEC_s_sb_block			(1 << 18)
1876 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1877 
1878 struct ext4_fs_context {
1879 	char		*s_qf_names[EXT4_MAXQUOTAS];
1880 	struct fscrypt_dummy_policy dummy_enc_policy;
1881 	int		s_jquota_fmt;	/* Format of quota to use */
1882 #ifdef CONFIG_EXT4_DEBUG
1883 	int s_fc_debug_max_replay;
1884 #endif
1885 	unsigned short	qname_spec;
1886 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1887 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1888 	unsigned long	journal_devnum;
1889 	unsigned long	s_commit_interval;
1890 	unsigned long	s_stripe;
1891 	unsigned int	s_inode_readahead_blks;
1892 	unsigned int	s_want_extra_isize;
1893 	unsigned int	s_li_wait_mult;
1894 	unsigned int	s_max_dir_size_kb;
1895 	unsigned int	journal_ioprio;
1896 	unsigned int	vals_s_mount_opt;
1897 	unsigned int	mask_s_mount_opt;
1898 	unsigned int	vals_s_mount_opt2;
1899 	unsigned int	mask_s_mount_opt2;
1900 	unsigned long	vals_s_mount_flags;
1901 	unsigned long	mask_s_mount_flags;
1902 	unsigned int	opt_flags;	/* MOPT flags */
1903 	unsigned int	spec;
1904 	u32		s_max_batch_time;
1905 	u32		s_min_batch_time;
1906 	kuid_t		s_resuid;
1907 	kgid_t		s_resgid;
1908 	ext4_fsblk_t	s_sb_block;
1909 };
1910 
1911 static void ext4_fc_free(struct fs_context *fc)
1912 {
1913 	struct ext4_fs_context *ctx = fc->fs_private;
1914 	int i;
1915 
1916 	if (!ctx)
1917 		return;
1918 
1919 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1920 		kfree(ctx->s_qf_names[i]);
1921 
1922 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1923 	kfree(ctx);
1924 }
1925 
1926 int ext4_init_fs_context(struct fs_context *fc)
1927 {
1928 	struct ext4_fs_context *ctx;
1929 
1930 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1931 	if (!ctx)
1932 		return -ENOMEM;
1933 
1934 	fc->fs_private = ctx;
1935 	fc->ops = &ext4_context_ops;
1936 
1937 	return 0;
1938 }
1939 
1940 #ifdef CONFIG_QUOTA
1941 /*
1942  * Note the name of the specified quota file.
1943  */
1944 static int note_qf_name(struct fs_context *fc, int qtype,
1945 		       struct fs_parameter *param)
1946 {
1947 	struct ext4_fs_context *ctx = fc->fs_private;
1948 	char *qname;
1949 
1950 	if (param->size < 1) {
1951 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
1952 		return -EINVAL;
1953 	}
1954 	if (strchr(param->string, '/')) {
1955 		ext4_msg(NULL, KERN_ERR,
1956 			 "quotafile must be on filesystem root");
1957 		return -EINVAL;
1958 	}
1959 	if (ctx->s_qf_names[qtype]) {
1960 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
1961 			ext4_msg(NULL, KERN_ERR,
1962 				 "%s quota file already specified",
1963 				 QTYPE2NAME(qtype));
1964 			return -EINVAL;
1965 		}
1966 		return 0;
1967 	}
1968 
1969 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
1970 	if (!qname) {
1971 		ext4_msg(NULL, KERN_ERR,
1972 			 "Not enough memory for storing quotafile name");
1973 		return -ENOMEM;
1974 	}
1975 	ctx->s_qf_names[qtype] = qname;
1976 	ctx->qname_spec |= 1 << qtype;
1977 	ctx->spec |= EXT4_SPEC_JQUOTA;
1978 	return 0;
1979 }
1980 
1981 /*
1982  * Clear the name of the specified quota file.
1983  */
1984 static int unnote_qf_name(struct fs_context *fc, int qtype)
1985 {
1986 	struct ext4_fs_context *ctx = fc->fs_private;
1987 
1988 	if (ctx->s_qf_names[qtype])
1989 		kfree(ctx->s_qf_names[qtype]);
1990 
1991 	ctx->s_qf_names[qtype] = NULL;
1992 	ctx->qname_spec |= 1 << qtype;
1993 	ctx->spec |= EXT4_SPEC_JQUOTA;
1994 	return 0;
1995 }
1996 #endif
1997 
1998 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
1999 					    struct ext4_fs_context *ctx)
2000 {
2001 	int err;
2002 
2003 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2004 		ext4_msg(NULL, KERN_WARNING,
2005 			 "test_dummy_encryption option not supported");
2006 		return -EINVAL;
2007 	}
2008 	err = fscrypt_parse_test_dummy_encryption(param,
2009 						  &ctx->dummy_enc_policy);
2010 	if (err == -EINVAL) {
2011 		ext4_msg(NULL, KERN_WARNING,
2012 			 "Value of option \"%s\" is unrecognized", param->key);
2013 	} else if (err == -EEXIST) {
2014 		ext4_msg(NULL, KERN_WARNING,
2015 			 "Conflicting test_dummy_encryption options");
2016 		return -EINVAL;
2017 	}
2018 	return err;
2019 }
2020 
2021 #define EXT4_SET_CTX(name)						\
2022 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2023 				  unsigned long flag)			\
2024 {									\
2025 	ctx->mask_s_##name |= flag;					\
2026 	ctx->vals_s_##name |= flag;					\
2027 }
2028 
2029 #define EXT4_CLEAR_CTX(name)						\
2030 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2031 				    unsigned long flag)			\
2032 {									\
2033 	ctx->mask_s_##name |= flag;					\
2034 	ctx->vals_s_##name &= ~flag;					\
2035 }
2036 
2037 #define EXT4_TEST_CTX(name)						\
2038 static inline unsigned long						\
2039 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2040 {									\
2041 	return (ctx->vals_s_##name & flag);				\
2042 }
2043 
2044 EXT4_SET_CTX(flags); /* set only */
2045 EXT4_SET_CTX(mount_opt);
2046 EXT4_CLEAR_CTX(mount_opt);
2047 EXT4_TEST_CTX(mount_opt);
2048 EXT4_SET_CTX(mount_opt2);
2049 EXT4_CLEAR_CTX(mount_opt2);
2050 EXT4_TEST_CTX(mount_opt2);
2051 
2052 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2053 {
2054 	set_bit(bit, &ctx->mask_s_mount_flags);
2055 	set_bit(bit, &ctx->vals_s_mount_flags);
2056 }
2057 
2058 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2059 {
2060 	struct ext4_fs_context *ctx = fc->fs_private;
2061 	struct fs_parse_result result;
2062 	const struct mount_opts *m;
2063 	int is_remount;
2064 	kuid_t uid;
2065 	kgid_t gid;
2066 	int token;
2067 
2068 	token = fs_parse(fc, ext4_param_specs, param, &result);
2069 	if (token < 0)
2070 		return token;
2071 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2072 
2073 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2074 		if (token == m->token)
2075 			break;
2076 
2077 	ctx->opt_flags |= m->flags;
2078 
2079 	if (m->flags & MOPT_EXPLICIT) {
2080 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2081 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2082 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2083 			ctx_set_mount_opt2(ctx,
2084 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2085 		} else
2086 			return -EINVAL;
2087 	}
2088 
2089 	if (m->flags & MOPT_NOSUPPORT) {
2090 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2091 			 param->key);
2092 		return 0;
2093 	}
2094 
2095 	switch (token) {
2096 #ifdef CONFIG_QUOTA
2097 	case Opt_usrjquota:
2098 		if (!*param->string)
2099 			return unnote_qf_name(fc, USRQUOTA);
2100 		else
2101 			return note_qf_name(fc, USRQUOTA, param);
2102 	case Opt_grpjquota:
2103 		if (!*param->string)
2104 			return unnote_qf_name(fc, GRPQUOTA);
2105 		else
2106 			return note_qf_name(fc, GRPQUOTA, param);
2107 #endif
2108 	case Opt_sb:
2109 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2110 			ext4_msg(NULL, KERN_WARNING,
2111 				 "Ignoring %s option on remount", param->key);
2112 		} else {
2113 			ctx->s_sb_block = result.uint_32;
2114 			ctx->spec |= EXT4_SPEC_s_sb_block;
2115 		}
2116 		return 0;
2117 	case Opt_removed:
2118 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2119 			 param->key);
2120 		return 0;
2121 	case Opt_abort:
2122 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2123 		return 0;
2124 	case Opt_inlinecrypt:
2125 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2126 		ctx_set_flags(ctx, SB_INLINECRYPT);
2127 #else
2128 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2129 #endif
2130 		return 0;
2131 	case Opt_errors:
2132 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2133 		ctx_set_mount_opt(ctx, result.uint_32);
2134 		return 0;
2135 #ifdef CONFIG_QUOTA
2136 	case Opt_jqfmt:
2137 		ctx->s_jquota_fmt = result.uint_32;
2138 		ctx->spec |= EXT4_SPEC_JQFMT;
2139 		return 0;
2140 #endif
2141 	case Opt_data:
2142 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2143 		ctx_set_mount_opt(ctx, result.uint_32);
2144 		ctx->spec |= EXT4_SPEC_DATAJ;
2145 		return 0;
2146 	case Opt_commit:
2147 		if (result.uint_32 == 0)
2148 			ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2149 		else if (result.uint_32 > INT_MAX / HZ) {
2150 			ext4_msg(NULL, KERN_ERR,
2151 				 "Invalid commit interval %d, "
2152 				 "must be smaller than %d",
2153 				 result.uint_32, INT_MAX / HZ);
2154 			return -EINVAL;
2155 		}
2156 		ctx->s_commit_interval = HZ * result.uint_32;
2157 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2158 		return 0;
2159 	case Opt_debug_want_extra_isize:
2160 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2161 			ext4_msg(NULL, KERN_ERR,
2162 				 "Invalid want_extra_isize %d", result.uint_32);
2163 			return -EINVAL;
2164 		}
2165 		ctx->s_want_extra_isize = result.uint_32;
2166 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2167 		return 0;
2168 	case Opt_max_batch_time:
2169 		ctx->s_max_batch_time = result.uint_32;
2170 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2171 		return 0;
2172 	case Opt_min_batch_time:
2173 		ctx->s_min_batch_time = result.uint_32;
2174 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2175 		return 0;
2176 	case Opt_inode_readahead_blks:
2177 		if (result.uint_32 &&
2178 		    (result.uint_32 > (1 << 30) ||
2179 		     !is_power_of_2(result.uint_32))) {
2180 			ext4_msg(NULL, KERN_ERR,
2181 				 "EXT4-fs: inode_readahead_blks must be "
2182 				 "0 or a power of 2 smaller than 2^31");
2183 			return -EINVAL;
2184 		}
2185 		ctx->s_inode_readahead_blks = result.uint_32;
2186 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2187 		return 0;
2188 	case Opt_init_itable:
2189 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2190 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2191 		if (param->type == fs_value_is_string)
2192 			ctx->s_li_wait_mult = result.uint_32;
2193 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2194 		return 0;
2195 	case Opt_max_dir_size_kb:
2196 		ctx->s_max_dir_size_kb = result.uint_32;
2197 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2198 		return 0;
2199 #ifdef CONFIG_EXT4_DEBUG
2200 	case Opt_fc_debug_max_replay:
2201 		ctx->s_fc_debug_max_replay = result.uint_32;
2202 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2203 		return 0;
2204 #endif
2205 	case Opt_stripe:
2206 		ctx->s_stripe = result.uint_32;
2207 		ctx->spec |= EXT4_SPEC_s_stripe;
2208 		return 0;
2209 	case Opt_resuid:
2210 		uid = make_kuid(current_user_ns(), result.uint_32);
2211 		if (!uid_valid(uid)) {
2212 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2213 				 result.uint_32);
2214 			return -EINVAL;
2215 		}
2216 		ctx->s_resuid = uid;
2217 		ctx->spec |= EXT4_SPEC_s_resuid;
2218 		return 0;
2219 	case Opt_resgid:
2220 		gid = make_kgid(current_user_ns(), result.uint_32);
2221 		if (!gid_valid(gid)) {
2222 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2223 				 result.uint_32);
2224 			return -EINVAL;
2225 		}
2226 		ctx->s_resgid = gid;
2227 		ctx->spec |= EXT4_SPEC_s_resgid;
2228 		return 0;
2229 	case Opt_journal_dev:
2230 		if (is_remount) {
2231 			ext4_msg(NULL, KERN_ERR,
2232 				 "Cannot specify journal on remount");
2233 			return -EINVAL;
2234 		}
2235 		ctx->journal_devnum = result.uint_32;
2236 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2237 		return 0;
2238 	case Opt_journal_path:
2239 	{
2240 		struct inode *journal_inode;
2241 		struct path path;
2242 		int error;
2243 
2244 		if (is_remount) {
2245 			ext4_msg(NULL, KERN_ERR,
2246 				 "Cannot specify journal on remount");
2247 			return -EINVAL;
2248 		}
2249 
2250 		error = fs_lookup_param(fc, param, 1, &path);
2251 		if (error) {
2252 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2253 				 "journal device path");
2254 			return -EINVAL;
2255 		}
2256 
2257 		journal_inode = d_inode(path.dentry);
2258 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2259 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2260 		path_put(&path);
2261 		return 0;
2262 	}
2263 	case Opt_journal_ioprio:
2264 		if (result.uint_32 > 7) {
2265 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2266 				 " (must be 0-7)");
2267 			return -EINVAL;
2268 		}
2269 		ctx->journal_ioprio =
2270 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2271 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2272 		return 0;
2273 	case Opt_test_dummy_encryption:
2274 		return ext4_parse_test_dummy_encryption(param, ctx);
2275 	case Opt_dax:
2276 	case Opt_dax_type:
2277 #ifdef CONFIG_FS_DAX
2278 	{
2279 		int type = (token == Opt_dax) ?
2280 			   Opt_dax : result.uint_32;
2281 
2282 		switch (type) {
2283 		case Opt_dax:
2284 		case Opt_dax_always:
2285 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2286 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2287 			break;
2288 		case Opt_dax_never:
2289 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2290 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2291 			break;
2292 		case Opt_dax_inode:
2293 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2294 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2295 			/* Strictly for printing options */
2296 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2297 			break;
2298 		}
2299 		return 0;
2300 	}
2301 #else
2302 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2303 		return -EINVAL;
2304 #endif
2305 	case Opt_data_err:
2306 		if (result.uint_32 == Opt_data_err_abort)
2307 			ctx_set_mount_opt(ctx, m->mount_opt);
2308 		else if (result.uint_32 == Opt_data_err_ignore)
2309 			ctx_clear_mount_opt(ctx, m->mount_opt);
2310 		return 0;
2311 	case Opt_mb_optimize_scan:
2312 		if (result.int_32 == 1) {
2313 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2314 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2315 		} else if (result.int_32 == 0) {
2316 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2317 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2318 		} else {
2319 			ext4_msg(NULL, KERN_WARNING,
2320 				 "mb_optimize_scan should be set to 0 or 1.");
2321 			return -EINVAL;
2322 		}
2323 		return 0;
2324 	}
2325 
2326 	/*
2327 	 * At this point we should only be getting options requiring MOPT_SET,
2328 	 * or MOPT_CLEAR. Anything else is a bug
2329 	 */
2330 	if (m->token == Opt_err) {
2331 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2332 			 param->key);
2333 		WARN_ON(1);
2334 		return -EINVAL;
2335 	}
2336 
2337 	else {
2338 		unsigned int set = 0;
2339 
2340 		if ((param->type == fs_value_is_flag) ||
2341 		    result.uint_32 > 0)
2342 			set = 1;
2343 
2344 		if (m->flags & MOPT_CLEAR)
2345 			set = !set;
2346 		else if (unlikely(!(m->flags & MOPT_SET))) {
2347 			ext4_msg(NULL, KERN_WARNING,
2348 				 "buggy handling of option %s",
2349 				 param->key);
2350 			WARN_ON(1);
2351 			return -EINVAL;
2352 		}
2353 		if (m->flags & MOPT_2) {
2354 			if (set != 0)
2355 				ctx_set_mount_opt2(ctx, m->mount_opt);
2356 			else
2357 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2358 		} else {
2359 			if (set != 0)
2360 				ctx_set_mount_opt(ctx, m->mount_opt);
2361 			else
2362 				ctx_clear_mount_opt(ctx, m->mount_opt);
2363 		}
2364 	}
2365 
2366 	return 0;
2367 }
2368 
2369 static int parse_options(struct fs_context *fc, char *options)
2370 {
2371 	struct fs_parameter param;
2372 	int ret;
2373 	char *key;
2374 
2375 	if (!options)
2376 		return 0;
2377 
2378 	while ((key = strsep(&options, ",")) != NULL) {
2379 		if (*key) {
2380 			size_t v_len = 0;
2381 			char *value = strchr(key, '=');
2382 
2383 			param.type = fs_value_is_flag;
2384 			param.string = NULL;
2385 
2386 			if (value) {
2387 				if (value == key)
2388 					continue;
2389 
2390 				*value++ = 0;
2391 				v_len = strlen(value);
2392 				param.string = kmemdup_nul(value, v_len,
2393 							   GFP_KERNEL);
2394 				if (!param.string)
2395 					return -ENOMEM;
2396 				param.type = fs_value_is_string;
2397 			}
2398 
2399 			param.key = key;
2400 			param.size = v_len;
2401 
2402 			ret = ext4_parse_param(fc, &param);
2403 			if (param.string)
2404 				kfree(param.string);
2405 			if (ret < 0)
2406 				return ret;
2407 		}
2408 	}
2409 
2410 	ret = ext4_validate_options(fc);
2411 	if (ret < 0)
2412 		return ret;
2413 
2414 	return 0;
2415 }
2416 
2417 static int parse_apply_sb_mount_options(struct super_block *sb,
2418 					struct ext4_fs_context *m_ctx)
2419 {
2420 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2421 	char *s_mount_opts = NULL;
2422 	struct ext4_fs_context *s_ctx = NULL;
2423 	struct fs_context *fc = NULL;
2424 	int ret = -ENOMEM;
2425 
2426 	if (!sbi->s_es->s_mount_opts[0])
2427 		return 0;
2428 
2429 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2430 				sizeof(sbi->s_es->s_mount_opts),
2431 				GFP_KERNEL);
2432 	if (!s_mount_opts)
2433 		return ret;
2434 
2435 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2436 	if (!fc)
2437 		goto out_free;
2438 
2439 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2440 	if (!s_ctx)
2441 		goto out_free;
2442 
2443 	fc->fs_private = s_ctx;
2444 	fc->s_fs_info = sbi;
2445 
2446 	ret = parse_options(fc, s_mount_opts);
2447 	if (ret < 0)
2448 		goto parse_failed;
2449 
2450 	ret = ext4_check_opt_consistency(fc, sb);
2451 	if (ret < 0) {
2452 parse_failed:
2453 		ext4_msg(sb, KERN_WARNING,
2454 			 "failed to parse options in superblock: %s",
2455 			 s_mount_opts);
2456 		ret = 0;
2457 		goto out_free;
2458 	}
2459 
2460 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2461 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2462 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2463 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2464 
2465 	ext4_apply_options(fc, sb);
2466 	ret = 0;
2467 
2468 out_free:
2469 	if (fc) {
2470 		ext4_fc_free(fc);
2471 		kfree(fc);
2472 	}
2473 	kfree(s_mount_opts);
2474 	return ret;
2475 }
2476 
2477 static void ext4_apply_quota_options(struct fs_context *fc,
2478 				     struct super_block *sb)
2479 {
2480 #ifdef CONFIG_QUOTA
2481 	bool quota_feature = ext4_has_feature_quota(sb);
2482 	struct ext4_fs_context *ctx = fc->fs_private;
2483 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2484 	char *qname;
2485 	int i;
2486 
2487 	if (quota_feature)
2488 		return;
2489 
2490 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2491 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2492 			if (!(ctx->qname_spec & (1 << i)))
2493 				continue;
2494 
2495 			qname = ctx->s_qf_names[i]; /* May be NULL */
2496 			if (qname)
2497 				set_opt(sb, QUOTA);
2498 			ctx->s_qf_names[i] = NULL;
2499 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2500 						lockdep_is_held(&sb->s_umount));
2501 			if (qname)
2502 				kfree_rcu(qname);
2503 		}
2504 	}
2505 
2506 	if (ctx->spec & EXT4_SPEC_JQFMT)
2507 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2508 #endif
2509 }
2510 
2511 /*
2512  * Check quota settings consistency.
2513  */
2514 static int ext4_check_quota_consistency(struct fs_context *fc,
2515 					struct super_block *sb)
2516 {
2517 #ifdef CONFIG_QUOTA
2518 	struct ext4_fs_context *ctx = fc->fs_private;
2519 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2520 	bool quota_feature = ext4_has_feature_quota(sb);
2521 	bool quota_loaded = sb_any_quota_loaded(sb);
2522 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2523 	int quota_flags, i;
2524 
2525 	/*
2526 	 * We do the test below only for project quotas. 'usrquota' and
2527 	 * 'grpquota' mount options are allowed even without quota feature
2528 	 * to support legacy quotas in quota files.
2529 	 */
2530 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2531 	    !ext4_has_feature_project(sb)) {
2532 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2533 			 "Cannot enable project quota enforcement.");
2534 		return -EINVAL;
2535 	}
2536 
2537 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2538 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2539 	if (quota_loaded &&
2540 	    ctx->mask_s_mount_opt & quota_flags &&
2541 	    !ctx_test_mount_opt(ctx, quota_flags))
2542 		goto err_quota_change;
2543 
2544 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2545 
2546 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2547 			if (!(ctx->qname_spec & (1 << i)))
2548 				continue;
2549 
2550 			if (quota_loaded &&
2551 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2552 				goto err_jquota_change;
2553 
2554 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2555 			    strcmp(get_qf_name(sb, sbi, i),
2556 				   ctx->s_qf_names[i]) != 0)
2557 				goto err_jquota_specified;
2558 		}
2559 
2560 		if (quota_feature) {
2561 			ext4_msg(NULL, KERN_INFO,
2562 				 "Journaled quota options ignored when "
2563 				 "QUOTA feature is enabled");
2564 			return 0;
2565 		}
2566 	}
2567 
2568 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2569 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2570 			goto err_jquota_change;
2571 		if (quota_feature) {
2572 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2573 				 "ignored when QUOTA feature is enabled");
2574 			return 0;
2575 		}
2576 	}
2577 
2578 	/* Make sure we don't mix old and new quota format */
2579 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2580 		       ctx->s_qf_names[USRQUOTA]);
2581 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2582 		       ctx->s_qf_names[GRPQUOTA]);
2583 
2584 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2585 		    test_opt(sb, USRQUOTA));
2586 
2587 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2588 		    test_opt(sb, GRPQUOTA));
2589 
2590 	if (usr_qf_name) {
2591 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2592 		usrquota = false;
2593 	}
2594 	if (grp_qf_name) {
2595 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2596 		grpquota = false;
2597 	}
2598 
2599 	if (usr_qf_name || grp_qf_name) {
2600 		if (usrquota || grpquota) {
2601 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2602 				 "format mixing");
2603 			return -EINVAL;
2604 		}
2605 
2606 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2607 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2608 				 "not specified");
2609 			return -EINVAL;
2610 		}
2611 	}
2612 
2613 	return 0;
2614 
2615 err_quota_change:
2616 	ext4_msg(NULL, KERN_ERR,
2617 		 "Cannot change quota options when quota turned on");
2618 	return -EINVAL;
2619 err_jquota_change:
2620 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2621 		 "options when quota turned on");
2622 	return -EINVAL;
2623 err_jquota_specified:
2624 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2625 		 QTYPE2NAME(i));
2626 	return -EINVAL;
2627 #else
2628 	return 0;
2629 #endif
2630 }
2631 
2632 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2633 					    struct super_block *sb)
2634 {
2635 	const struct ext4_fs_context *ctx = fc->fs_private;
2636 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2637 	int err;
2638 
2639 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2640 		return 0;
2641 
2642 	if (!ext4_has_feature_encrypt(sb)) {
2643 		ext4_msg(NULL, KERN_WARNING,
2644 			 "test_dummy_encryption requires encrypt feature");
2645 		return -EINVAL;
2646 	}
2647 	/*
2648 	 * This mount option is just for testing, and it's not worthwhile to
2649 	 * implement the extra complexity (e.g. RCU protection) that would be
2650 	 * needed to allow it to be set or changed during remount.  We do allow
2651 	 * it to be specified during remount, but only if there is no change.
2652 	 */
2653 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2654 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2655 						 &ctx->dummy_enc_policy))
2656 			return 0;
2657 		ext4_msg(NULL, KERN_WARNING,
2658 			 "Can't set or change test_dummy_encryption on remount");
2659 		return -EINVAL;
2660 	}
2661 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2662 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2663 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2664 						 &ctx->dummy_enc_policy))
2665 			return 0;
2666 		ext4_msg(NULL, KERN_WARNING,
2667 			 "Conflicting test_dummy_encryption options");
2668 		return -EINVAL;
2669 	}
2670 	/*
2671 	 * fscrypt_add_test_dummy_key() technically changes the super_block, so
2672 	 * technically it should be delayed until ext4_apply_options() like the
2673 	 * other changes.  But since we never get here for remounts (see above),
2674 	 * and this is the last chance to report errors, we do it here.
2675 	 */
2676 	err = fscrypt_add_test_dummy_key(sb, &ctx->dummy_enc_policy);
2677 	if (err)
2678 		ext4_msg(NULL, KERN_WARNING,
2679 			 "Error adding test dummy encryption key [%d]", err);
2680 	return err;
2681 }
2682 
2683 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2684 					     struct super_block *sb)
2685 {
2686 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2687 	    /* if already set, it was already verified to be the same */
2688 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2689 		return;
2690 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2691 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2692 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2693 }
2694 
2695 static int ext4_check_opt_consistency(struct fs_context *fc,
2696 				      struct super_block *sb)
2697 {
2698 	struct ext4_fs_context *ctx = fc->fs_private;
2699 	struct ext4_sb_info *sbi = fc->s_fs_info;
2700 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2701 	int err;
2702 
2703 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2704 		ext4_msg(NULL, KERN_ERR,
2705 			 "Mount option(s) incompatible with ext2");
2706 		return -EINVAL;
2707 	}
2708 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2709 		ext4_msg(NULL, KERN_ERR,
2710 			 "Mount option(s) incompatible with ext3");
2711 		return -EINVAL;
2712 	}
2713 
2714 	if (ctx->s_want_extra_isize >
2715 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2716 		ext4_msg(NULL, KERN_ERR,
2717 			 "Invalid want_extra_isize %d",
2718 			 ctx->s_want_extra_isize);
2719 		return -EINVAL;
2720 	}
2721 
2722 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2723 		int blocksize =
2724 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2725 		if (blocksize < PAGE_SIZE)
2726 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2727 				 "experimental mount option 'dioread_nolock' "
2728 				 "for blocksize < PAGE_SIZE");
2729 	}
2730 
2731 	err = ext4_check_test_dummy_encryption(fc, sb);
2732 	if (err)
2733 		return err;
2734 
2735 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2736 		if (!sbi->s_journal) {
2737 			ext4_msg(NULL, KERN_WARNING,
2738 				 "Remounting file system with no journal "
2739 				 "so ignoring journalled data option");
2740 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2741 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2742 			   test_opt(sb, DATA_FLAGS)) {
2743 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2744 				 "on remount");
2745 			return -EINVAL;
2746 		}
2747 	}
2748 
2749 	if (is_remount) {
2750 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2751 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2752 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2753 				 "both data=journal and dax");
2754 			return -EINVAL;
2755 		}
2756 
2757 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2758 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2759 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2760 fail_dax_change_remount:
2761 			ext4_msg(NULL, KERN_ERR, "can't change "
2762 				 "dax mount option while remounting");
2763 			return -EINVAL;
2764 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2765 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2766 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2767 			goto fail_dax_change_remount;
2768 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2769 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2770 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2771 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2772 			goto fail_dax_change_remount;
2773 		}
2774 	}
2775 
2776 	return ext4_check_quota_consistency(fc, sb);
2777 }
2778 
2779 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2780 {
2781 	struct ext4_fs_context *ctx = fc->fs_private;
2782 	struct ext4_sb_info *sbi = fc->s_fs_info;
2783 
2784 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2785 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2786 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2787 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2788 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2789 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2790 	sb->s_flags &= ~ctx->mask_s_flags;
2791 	sb->s_flags |= ctx->vals_s_flags;
2792 
2793 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2794 	APPLY(s_commit_interval);
2795 	APPLY(s_stripe);
2796 	APPLY(s_max_batch_time);
2797 	APPLY(s_min_batch_time);
2798 	APPLY(s_want_extra_isize);
2799 	APPLY(s_inode_readahead_blks);
2800 	APPLY(s_max_dir_size_kb);
2801 	APPLY(s_li_wait_mult);
2802 	APPLY(s_resgid);
2803 	APPLY(s_resuid);
2804 
2805 #ifdef CONFIG_EXT4_DEBUG
2806 	APPLY(s_fc_debug_max_replay);
2807 #endif
2808 
2809 	ext4_apply_quota_options(fc, sb);
2810 	ext4_apply_test_dummy_encryption(ctx, sb);
2811 }
2812 
2813 
2814 static int ext4_validate_options(struct fs_context *fc)
2815 {
2816 #ifdef CONFIG_QUOTA
2817 	struct ext4_fs_context *ctx = fc->fs_private;
2818 	char *usr_qf_name, *grp_qf_name;
2819 
2820 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2821 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2822 
2823 	if (usr_qf_name || grp_qf_name) {
2824 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2825 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2826 
2827 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2828 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2829 
2830 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2831 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2832 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2833 				 "format mixing");
2834 			return -EINVAL;
2835 		}
2836 	}
2837 #endif
2838 	return 1;
2839 }
2840 
2841 static inline void ext4_show_quota_options(struct seq_file *seq,
2842 					   struct super_block *sb)
2843 {
2844 #if defined(CONFIG_QUOTA)
2845 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2846 	char *usr_qf_name, *grp_qf_name;
2847 
2848 	if (sbi->s_jquota_fmt) {
2849 		char *fmtname = "";
2850 
2851 		switch (sbi->s_jquota_fmt) {
2852 		case QFMT_VFS_OLD:
2853 			fmtname = "vfsold";
2854 			break;
2855 		case QFMT_VFS_V0:
2856 			fmtname = "vfsv0";
2857 			break;
2858 		case QFMT_VFS_V1:
2859 			fmtname = "vfsv1";
2860 			break;
2861 		}
2862 		seq_printf(seq, ",jqfmt=%s", fmtname);
2863 	}
2864 
2865 	rcu_read_lock();
2866 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2867 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2868 	if (usr_qf_name)
2869 		seq_show_option(seq, "usrjquota", usr_qf_name);
2870 	if (grp_qf_name)
2871 		seq_show_option(seq, "grpjquota", grp_qf_name);
2872 	rcu_read_unlock();
2873 #endif
2874 }
2875 
2876 static const char *token2str(int token)
2877 {
2878 	const struct fs_parameter_spec *spec;
2879 
2880 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2881 		if (spec->opt == token && !spec->type)
2882 			break;
2883 	return spec->name;
2884 }
2885 
2886 /*
2887  * Show an option if
2888  *  - it's set to a non-default value OR
2889  *  - if the per-sb default is different from the global default
2890  */
2891 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2892 			      int nodefs)
2893 {
2894 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2895 	struct ext4_super_block *es = sbi->s_es;
2896 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2897 	const struct mount_opts *m;
2898 	char sep = nodefs ? '\n' : ',';
2899 
2900 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2901 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2902 
2903 	if (sbi->s_sb_block != 1)
2904 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2905 
2906 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2907 		int want_set = m->flags & MOPT_SET;
2908 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2909 		    m->flags & MOPT_SKIP)
2910 			continue;
2911 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2912 			continue; /* skip if same as the default */
2913 		if ((want_set &&
2914 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2915 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2916 			continue; /* select Opt_noFoo vs Opt_Foo */
2917 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2918 	}
2919 
2920 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2921 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2922 		SEQ_OPTS_PRINT("resuid=%u",
2923 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2924 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2925 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2926 		SEQ_OPTS_PRINT("resgid=%u",
2927 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2928 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2929 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2930 		SEQ_OPTS_PUTS("errors=remount-ro");
2931 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2932 		SEQ_OPTS_PUTS("errors=continue");
2933 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2934 		SEQ_OPTS_PUTS("errors=panic");
2935 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2936 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2937 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2938 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2939 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2940 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2941 	if (nodefs || sbi->s_stripe)
2942 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2943 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2944 			(sbi->s_mount_opt ^ def_mount_opt)) {
2945 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2946 			SEQ_OPTS_PUTS("data=journal");
2947 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2948 			SEQ_OPTS_PUTS("data=ordered");
2949 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2950 			SEQ_OPTS_PUTS("data=writeback");
2951 	}
2952 	if (nodefs ||
2953 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2954 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2955 			       sbi->s_inode_readahead_blks);
2956 
2957 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2958 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2959 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2960 	if (nodefs || sbi->s_max_dir_size_kb)
2961 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2962 	if (test_opt(sb, DATA_ERR_ABORT))
2963 		SEQ_OPTS_PUTS("data_err=abort");
2964 
2965 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2966 
2967 	if (sb->s_flags & SB_INLINECRYPT)
2968 		SEQ_OPTS_PUTS("inlinecrypt");
2969 
2970 	if (test_opt(sb, DAX_ALWAYS)) {
2971 		if (IS_EXT2_SB(sb))
2972 			SEQ_OPTS_PUTS("dax");
2973 		else
2974 			SEQ_OPTS_PUTS("dax=always");
2975 	} else if (test_opt2(sb, DAX_NEVER)) {
2976 		SEQ_OPTS_PUTS("dax=never");
2977 	} else if (test_opt2(sb, DAX_INODE)) {
2978 		SEQ_OPTS_PUTS("dax=inode");
2979 	}
2980 
2981 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
2982 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
2983 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
2984 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
2985 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
2986 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
2987 	}
2988 
2989 	ext4_show_quota_options(seq, sb);
2990 	return 0;
2991 }
2992 
2993 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2994 {
2995 	return _ext4_show_options(seq, root->d_sb, 0);
2996 }
2997 
2998 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2999 {
3000 	struct super_block *sb = seq->private;
3001 	int rc;
3002 
3003 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3004 	rc = _ext4_show_options(seq, sb, 1);
3005 	seq_puts(seq, "\n");
3006 	return rc;
3007 }
3008 
3009 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3010 			    int read_only)
3011 {
3012 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3013 	int err = 0;
3014 
3015 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3016 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3017 			 "forcing read-only mode");
3018 		err = -EROFS;
3019 		goto done;
3020 	}
3021 	if (read_only)
3022 		goto done;
3023 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3024 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3025 			 "running e2fsck is recommended");
3026 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3027 		ext4_msg(sb, KERN_WARNING,
3028 			 "warning: mounting fs with errors, "
3029 			 "running e2fsck is recommended");
3030 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3031 		 le16_to_cpu(es->s_mnt_count) >=
3032 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3033 		ext4_msg(sb, KERN_WARNING,
3034 			 "warning: maximal mount count reached, "
3035 			 "running e2fsck is recommended");
3036 	else if (le32_to_cpu(es->s_checkinterval) &&
3037 		 (ext4_get_tstamp(es, s_lastcheck) +
3038 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3039 		ext4_msg(sb, KERN_WARNING,
3040 			 "warning: checktime reached, "
3041 			 "running e2fsck is recommended");
3042 	if (!sbi->s_journal)
3043 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3044 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3045 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3046 	le16_add_cpu(&es->s_mnt_count, 1);
3047 	ext4_update_tstamp(es, s_mtime);
3048 	if (sbi->s_journal) {
3049 		ext4_set_feature_journal_needs_recovery(sb);
3050 		if (ext4_has_feature_orphan_file(sb))
3051 			ext4_set_feature_orphan_present(sb);
3052 	}
3053 
3054 	err = ext4_commit_super(sb);
3055 done:
3056 	if (test_opt(sb, DEBUG))
3057 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3058 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3059 			sb->s_blocksize,
3060 			sbi->s_groups_count,
3061 			EXT4_BLOCKS_PER_GROUP(sb),
3062 			EXT4_INODES_PER_GROUP(sb),
3063 			sbi->s_mount_opt, sbi->s_mount_opt2);
3064 	return err;
3065 }
3066 
3067 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3068 {
3069 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3070 	struct flex_groups **old_groups, **new_groups;
3071 	int size, i, j;
3072 
3073 	if (!sbi->s_log_groups_per_flex)
3074 		return 0;
3075 
3076 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3077 	if (size <= sbi->s_flex_groups_allocated)
3078 		return 0;
3079 
3080 	new_groups = kvzalloc(roundup_pow_of_two(size *
3081 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3082 	if (!new_groups) {
3083 		ext4_msg(sb, KERN_ERR,
3084 			 "not enough memory for %d flex group pointers", size);
3085 		return -ENOMEM;
3086 	}
3087 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3088 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3089 					 sizeof(struct flex_groups)),
3090 					 GFP_KERNEL);
3091 		if (!new_groups[i]) {
3092 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3093 				kvfree(new_groups[j]);
3094 			kvfree(new_groups);
3095 			ext4_msg(sb, KERN_ERR,
3096 				 "not enough memory for %d flex groups", size);
3097 			return -ENOMEM;
3098 		}
3099 	}
3100 	rcu_read_lock();
3101 	old_groups = rcu_dereference(sbi->s_flex_groups);
3102 	if (old_groups)
3103 		memcpy(new_groups, old_groups,
3104 		       (sbi->s_flex_groups_allocated *
3105 			sizeof(struct flex_groups *)));
3106 	rcu_read_unlock();
3107 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3108 	sbi->s_flex_groups_allocated = size;
3109 	if (old_groups)
3110 		ext4_kvfree_array_rcu(old_groups);
3111 	return 0;
3112 }
3113 
3114 static int ext4_fill_flex_info(struct super_block *sb)
3115 {
3116 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3117 	struct ext4_group_desc *gdp = NULL;
3118 	struct flex_groups *fg;
3119 	ext4_group_t flex_group;
3120 	int i, err;
3121 
3122 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3123 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3124 		sbi->s_log_groups_per_flex = 0;
3125 		return 1;
3126 	}
3127 
3128 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3129 	if (err)
3130 		goto failed;
3131 
3132 	for (i = 0; i < sbi->s_groups_count; i++) {
3133 		gdp = ext4_get_group_desc(sb, i, NULL);
3134 
3135 		flex_group = ext4_flex_group(sbi, i);
3136 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3137 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3138 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3139 			     &fg->free_clusters);
3140 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3141 	}
3142 
3143 	return 1;
3144 failed:
3145 	return 0;
3146 }
3147 
3148 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3149 				   struct ext4_group_desc *gdp)
3150 {
3151 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3152 	__u16 crc = 0;
3153 	__le32 le_group = cpu_to_le32(block_group);
3154 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3155 
3156 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3157 		/* Use new metadata_csum algorithm */
3158 		__u32 csum32;
3159 		__u16 dummy_csum = 0;
3160 
3161 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3162 				     sizeof(le_group));
3163 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3164 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3165 				     sizeof(dummy_csum));
3166 		offset += sizeof(dummy_csum);
3167 		if (offset < sbi->s_desc_size)
3168 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3169 					     sbi->s_desc_size - offset);
3170 
3171 		crc = csum32 & 0xFFFF;
3172 		goto out;
3173 	}
3174 
3175 	/* old crc16 code */
3176 	if (!ext4_has_feature_gdt_csum(sb))
3177 		return 0;
3178 
3179 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3180 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3181 	crc = crc16(crc, (__u8 *)gdp, offset);
3182 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3183 	/* for checksum of struct ext4_group_desc do the rest...*/
3184 	if (ext4_has_feature_64bit(sb) &&
3185 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3186 		crc = crc16(crc, (__u8 *)gdp + offset,
3187 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3188 				offset);
3189 
3190 out:
3191 	return cpu_to_le16(crc);
3192 }
3193 
3194 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3195 				struct ext4_group_desc *gdp)
3196 {
3197 	if (ext4_has_group_desc_csum(sb) &&
3198 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3199 		return 0;
3200 
3201 	return 1;
3202 }
3203 
3204 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3205 			      struct ext4_group_desc *gdp)
3206 {
3207 	if (!ext4_has_group_desc_csum(sb))
3208 		return;
3209 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3210 }
3211 
3212 /* Called at mount-time, super-block is locked */
3213 static int ext4_check_descriptors(struct super_block *sb,
3214 				  ext4_fsblk_t sb_block,
3215 				  ext4_group_t *first_not_zeroed)
3216 {
3217 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3218 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3219 	ext4_fsblk_t last_block;
3220 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3221 	ext4_fsblk_t block_bitmap;
3222 	ext4_fsblk_t inode_bitmap;
3223 	ext4_fsblk_t inode_table;
3224 	int flexbg_flag = 0;
3225 	ext4_group_t i, grp = sbi->s_groups_count;
3226 
3227 	if (ext4_has_feature_flex_bg(sb))
3228 		flexbg_flag = 1;
3229 
3230 	ext4_debug("Checking group descriptors");
3231 
3232 	for (i = 0; i < sbi->s_groups_count; i++) {
3233 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3234 
3235 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3236 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3237 		else
3238 			last_block = first_block +
3239 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3240 
3241 		if ((grp == sbi->s_groups_count) &&
3242 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3243 			grp = i;
3244 
3245 		block_bitmap = ext4_block_bitmap(sb, gdp);
3246 		if (block_bitmap == sb_block) {
3247 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3248 				 "Block bitmap for group %u overlaps "
3249 				 "superblock", i);
3250 			if (!sb_rdonly(sb))
3251 				return 0;
3252 		}
3253 		if (block_bitmap >= sb_block + 1 &&
3254 		    block_bitmap <= last_bg_block) {
3255 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3256 				 "Block bitmap for group %u overlaps "
3257 				 "block group descriptors", i);
3258 			if (!sb_rdonly(sb))
3259 				return 0;
3260 		}
3261 		if (block_bitmap < first_block || block_bitmap > last_block) {
3262 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3263 			       "Block bitmap for group %u not in group "
3264 			       "(block %llu)!", i, block_bitmap);
3265 			return 0;
3266 		}
3267 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3268 		if (inode_bitmap == sb_block) {
3269 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3270 				 "Inode bitmap for group %u overlaps "
3271 				 "superblock", i);
3272 			if (!sb_rdonly(sb))
3273 				return 0;
3274 		}
3275 		if (inode_bitmap >= sb_block + 1 &&
3276 		    inode_bitmap <= last_bg_block) {
3277 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3278 				 "Inode bitmap for group %u overlaps "
3279 				 "block group descriptors", i);
3280 			if (!sb_rdonly(sb))
3281 				return 0;
3282 		}
3283 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3284 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3285 			       "Inode bitmap for group %u not in group "
3286 			       "(block %llu)!", i, inode_bitmap);
3287 			return 0;
3288 		}
3289 		inode_table = ext4_inode_table(sb, gdp);
3290 		if (inode_table == sb_block) {
3291 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3292 				 "Inode table for group %u overlaps "
3293 				 "superblock", i);
3294 			if (!sb_rdonly(sb))
3295 				return 0;
3296 		}
3297 		if (inode_table >= sb_block + 1 &&
3298 		    inode_table <= last_bg_block) {
3299 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3300 				 "Inode table for group %u overlaps "
3301 				 "block group descriptors", i);
3302 			if (!sb_rdonly(sb))
3303 				return 0;
3304 		}
3305 		if (inode_table < first_block ||
3306 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3307 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3308 			       "Inode table for group %u not in group "
3309 			       "(block %llu)!", i, inode_table);
3310 			return 0;
3311 		}
3312 		ext4_lock_group(sb, i);
3313 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3314 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3315 				 "Checksum for group %u failed (%u!=%u)",
3316 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3317 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3318 			if (!sb_rdonly(sb)) {
3319 				ext4_unlock_group(sb, i);
3320 				return 0;
3321 			}
3322 		}
3323 		ext4_unlock_group(sb, i);
3324 		if (!flexbg_flag)
3325 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3326 	}
3327 	if (NULL != first_not_zeroed)
3328 		*first_not_zeroed = grp;
3329 	return 1;
3330 }
3331 
3332 /*
3333  * Maximal extent format file size.
3334  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3335  * extent format containers, within a sector_t, and within i_blocks
3336  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3337  * so that won't be a limiting factor.
3338  *
3339  * However there is other limiting factor. We do store extents in the form
3340  * of starting block and length, hence the resulting length of the extent
3341  * covering maximum file size must fit into on-disk format containers as
3342  * well. Given that length is always by 1 unit bigger than max unit (because
3343  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3344  *
3345  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3346  */
3347 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3348 {
3349 	loff_t res;
3350 	loff_t upper_limit = MAX_LFS_FILESIZE;
3351 
3352 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3353 
3354 	if (!has_huge_files) {
3355 		upper_limit = (1LL << 32) - 1;
3356 
3357 		/* total blocks in file system block size */
3358 		upper_limit >>= (blkbits - 9);
3359 		upper_limit <<= blkbits;
3360 	}
3361 
3362 	/*
3363 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3364 	 * by one fs block, so ee_len can cover the extent of maximum file
3365 	 * size
3366 	 */
3367 	res = (1LL << 32) - 1;
3368 	res <<= blkbits;
3369 
3370 	/* Sanity check against vm- & vfs- imposed limits */
3371 	if (res > upper_limit)
3372 		res = upper_limit;
3373 
3374 	return res;
3375 }
3376 
3377 /*
3378  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3379  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3380  * We need to be 1 filesystem block less than the 2^48 sector limit.
3381  */
3382 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3383 {
3384 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3385 	int meta_blocks;
3386 	unsigned int ppb = 1 << (bits - 2);
3387 
3388 	/*
3389 	 * This is calculated to be the largest file size for a dense, block
3390 	 * mapped file such that the file's total number of 512-byte sectors,
3391 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3392 	 *
3393 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3394 	 * number of 512-byte sectors of the file.
3395 	 */
3396 	if (!has_huge_files) {
3397 		/*
3398 		 * !has_huge_files or implies that the inode i_block field
3399 		 * represents total file blocks in 2^32 512-byte sectors ==
3400 		 * size of vfs inode i_blocks * 8
3401 		 */
3402 		upper_limit = (1LL << 32) - 1;
3403 
3404 		/* total blocks in file system block size */
3405 		upper_limit >>= (bits - 9);
3406 
3407 	} else {
3408 		/*
3409 		 * We use 48 bit ext4_inode i_blocks
3410 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3411 		 * represent total number of blocks in
3412 		 * file system block size
3413 		 */
3414 		upper_limit = (1LL << 48) - 1;
3415 
3416 	}
3417 
3418 	/* Compute how many blocks we can address by block tree */
3419 	res += ppb;
3420 	res += ppb * ppb;
3421 	res += ((loff_t)ppb) * ppb * ppb;
3422 	/* Compute how many metadata blocks are needed */
3423 	meta_blocks = 1;
3424 	meta_blocks += 1 + ppb;
3425 	meta_blocks += 1 + ppb + ppb * ppb;
3426 	/* Does block tree limit file size? */
3427 	if (res + meta_blocks <= upper_limit)
3428 		goto check_lfs;
3429 
3430 	res = upper_limit;
3431 	/* How many metadata blocks are needed for addressing upper_limit? */
3432 	upper_limit -= EXT4_NDIR_BLOCKS;
3433 	/* indirect blocks */
3434 	meta_blocks = 1;
3435 	upper_limit -= ppb;
3436 	/* double indirect blocks */
3437 	if (upper_limit < ppb * ppb) {
3438 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3439 		res -= meta_blocks;
3440 		goto check_lfs;
3441 	}
3442 	meta_blocks += 1 + ppb;
3443 	upper_limit -= ppb * ppb;
3444 	/* tripple indirect blocks for the rest */
3445 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3446 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3447 	res -= meta_blocks;
3448 check_lfs:
3449 	res <<= bits;
3450 	if (res > MAX_LFS_FILESIZE)
3451 		res = MAX_LFS_FILESIZE;
3452 
3453 	return res;
3454 }
3455 
3456 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3457 				   ext4_fsblk_t logical_sb_block, int nr)
3458 {
3459 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3460 	ext4_group_t bg, first_meta_bg;
3461 	int has_super = 0;
3462 
3463 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3464 
3465 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3466 		return logical_sb_block + nr + 1;
3467 	bg = sbi->s_desc_per_block * nr;
3468 	if (ext4_bg_has_super(sb, bg))
3469 		has_super = 1;
3470 
3471 	/*
3472 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3473 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3474 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3475 	 * compensate.
3476 	 */
3477 	if (sb->s_blocksize == 1024 && nr == 0 &&
3478 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3479 		has_super++;
3480 
3481 	return (has_super + ext4_group_first_block_no(sb, bg));
3482 }
3483 
3484 /**
3485  * ext4_get_stripe_size: Get the stripe size.
3486  * @sbi: In memory super block info
3487  *
3488  * If we have specified it via mount option, then
3489  * use the mount option value. If the value specified at mount time is
3490  * greater than the blocks per group use the super block value.
3491  * If the super block value is greater than blocks per group return 0.
3492  * Allocator needs it be less than blocks per group.
3493  *
3494  */
3495 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3496 {
3497 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3498 	unsigned long stripe_width =
3499 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3500 	int ret;
3501 
3502 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3503 		ret = sbi->s_stripe;
3504 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3505 		ret = stripe_width;
3506 	else if (stride && stride <= sbi->s_blocks_per_group)
3507 		ret = stride;
3508 	else
3509 		ret = 0;
3510 
3511 	/*
3512 	 * If the stripe width is 1, this makes no sense and
3513 	 * we set it to 0 to turn off stripe handling code.
3514 	 */
3515 	if (ret <= 1)
3516 		ret = 0;
3517 
3518 	return ret;
3519 }
3520 
3521 /*
3522  * Check whether this filesystem can be mounted based on
3523  * the features present and the RDONLY/RDWR mount requested.
3524  * Returns 1 if this filesystem can be mounted as requested,
3525  * 0 if it cannot be.
3526  */
3527 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3528 {
3529 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3530 		ext4_msg(sb, KERN_ERR,
3531 			"Couldn't mount because of "
3532 			"unsupported optional features (%x)",
3533 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3534 			~EXT4_FEATURE_INCOMPAT_SUPP));
3535 		return 0;
3536 	}
3537 
3538 #if !IS_ENABLED(CONFIG_UNICODE)
3539 	if (ext4_has_feature_casefold(sb)) {
3540 		ext4_msg(sb, KERN_ERR,
3541 			 "Filesystem with casefold feature cannot be "
3542 			 "mounted without CONFIG_UNICODE");
3543 		return 0;
3544 	}
3545 #endif
3546 
3547 	if (readonly)
3548 		return 1;
3549 
3550 	if (ext4_has_feature_readonly(sb)) {
3551 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3552 		sb->s_flags |= SB_RDONLY;
3553 		return 1;
3554 	}
3555 
3556 	/* Check that feature set is OK for a read-write mount */
3557 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3558 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3559 			 "unsupported optional features (%x)",
3560 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3561 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3562 		return 0;
3563 	}
3564 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3565 		ext4_msg(sb, KERN_ERR,
3566 			 "Can't support bigalloc feature without "
3567 			 "extents feature\n");
3568 		return 0;
3569 	}
3570 
3571 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3572 	if (!readonly && (ext4_has_feature_quota(sb) ||
3573 			  ext4_has_feature_project(sb))) {
3574 		ext4_msg(sb, KERN_ERR,
3575 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3576 		return 0;
3577 	}
3578 #endif  /* CONFIG_QUOTA */
3579 	return 1;
3580 }
3581 
3582 /*
3583  * This function is called once a day if we have errors logged
3584  * on the file system
3585  */
3586 static void print_daily_error_info(struct timer_list *t)
3587 {
3588 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3589 	struct super_block *sb = sbi->s_sb;
3590 	struct ext4_super_block *es = sbi->s_es;
3591 
3592 	if (es->s_error_count)
3593 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3594 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3595 			 le32_to_cpu(es->s_error_count));
3596 	if (es->s_first_error_time) {
3597 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3598 		       sb->s_id,
3599 		       ext4_get_tstamp(es, s_first_error_time),
3600 		       (int) sizeof(es->s_first_error_func),
3601 		       es->s_first_error_func,
3602 		       le32_to_cpu(es->s_first_error_line));
3603 		if (es->s_first_error_ino)
3604 			printk(KERN_CONT ": inode %u",
3605 			       le32_to_cpu(es->s_first_error_ino));
3606 		if (es->s_first_error_block)
3607 			printk(KERN_CONT ": block %llu", (unsigned long long)
3608 			       le64_to_cpu(es->s_first_error_block));
3609 		printk(KERN_CONT "\n");
3610 	}
3611 	if (es->s_last_error_time) {
3612 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3613 		       sb->s_id,
3614 		       ext4_get_tstamp(es, s_last_error_time),
3615 		       (int) sizeof(es->s_last_error_func),
3616 		       es->s_last_error_func,
3617 		       le32_to_cpu(es->s_last_error_line));
3618 		if (es->s_last_error_ino)
3619 			printk(KERN_CONT ": inode %u",
3620 			       le32_to_cpu(es->s_last_error_ino));
3621 		if (es->s_last_error_block)
3622 			printk(KERN_CONT ": block %llu", (unsigned long long)
3623 			       le64_to_cpu(es->s_last_error_block));
3624 		printk(KERN_CONT "\n");
3625 	}
3626 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3627 }
3628 
3629 /* Find next suitable group and run ext4_init_inode_table */
3630 static int ext4_run_li_request(struct ext4_li_request *elr)
3631 {
3632 	struct ext4_group_desc *gdp = NULL;
3633 	struct super_block *sb = elr->lr_super;
3634 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3635 	ext4_group_t group = elr->lr_next_group;
3636 	unsigned int prefetch_ios = 0;
3637 	int ret = 0;
3638 	u64 start_time;
3639 
3640 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3641 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3642 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3643 		if (prefetch_ios)
3644 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3645 					      prefetch_ios);
3646 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3647 					    prefetch_ios);
3648 		if (group >= elr->lr_next_group) {
3649 			ret = 1;
3650 			if (elr->lr_first_not_zeroed != ngroups &&
3651 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3652 				elr->lr_next_group = elr->lr_first_not_zeroed;
3653 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3654 				ret = 0;
3655 			}
3656 		}
3657 		return ret;
3658 	}
3659 
3660 	for (; group < ngroups; group++) {
3661 		gdp = ext4_get_group_desc(sb, group, NULL);
3662 		if (!gdp) {
3663 			ret = 1;
3664 			break;
3665 		}
3666 
3667 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3668 			break;
3669 	}
3670 
3671 	if (group >= ngroups)
3672 		ret = 1;
3673 
3674 	if (!ret) {
3675 		start_time = ktime_get_real_ns();
3676 		ret = ext4_init_inode_table(sb, group,
3677 					    elr->lr_timeout ? 0 : 1);
3678 		trace_ext4_lazy_itable_init(sb, group);
3679 		if (elr->lr_timeout == 0) {
3680 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3681 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3682 		}
3683 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3684 		elr->lr_next_group = group + 1;
3685 	}
3686 	return ret;
3687 }
3688 
3689 /*
3690  * Remove lr_request from the list_request and free the
3691  * request structure. Should be called with li_list_mtx held
3692  */
3693 static void ext4_remove_li_request(struct ext4_li_request *elr)
3694 {
3695 	if (!elr)
3696 		return;
3697 
3698 	list_del(&elr->lr_request);
3699 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3700 	kfree(elr);
3701 }
3702 
3703 static void ext4_unregister_li_request(struct super_block *sb)
3704 {
3705 	mutex_lock(&ext4_li_mtx);
3706 	if (!ext4_li_info) {
3707 		mutex_unlock(&ext4_li_mtx);
3708 		return;
3709 	}
3710 
3711 	mutex_lock(&ext4_li_info->li_list_mtx);
3712 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3713 	mutex_unlock(&ext4_li_info->li_list_mtx);
3714 	mutex_unlock(&ext4_li_mtx);
3715 }
3716 
3717 static struct task_struct *ext4_lazyinit_task;
3718 
3719 /*
3720  * This is the function where ext4lazyinit thread lives. It walks
3721  * through the request list searching for next scheduled filesystem.
3722  * When such a fs is found, run the lazy initialization request
3723  * (ext4_rn_li_request) and keep track of the time spend in this
3724  * function. Based on that time we compute next schedule time of
3725  * the request. When walking through the list is complete, compute
3726  * next waking time and put itself into sleep.
3727  */
3728 static int ext4_lazyinit_thread(void *arg)
3729 {
3730 	struct ext4_lazy_init *eli = arg;
3731 	struct list_head *pos, *n;
3732 	struct ext4_li_request *elr;
3733 	unsigned long next_wakeup, cur;
3734 
3735 	BUG_ON(NULL == eli);
3736 	set_freezable();
3737 
3738 cont_thread:
3739 	while (true) {
3740 		next_wakeup = MAX_JIFFY_OFFSET;
3741 
3742 		mutex_lock(&eli->li_list_mtx);
3743 		if (list_empty(&eli->li_request_list)) {
3744 			mutex_unlock(&eli->li_list_mtx);
3745 			goto exit_thread;
3746 		}
3747 		list_for_each_safe(pos, n, &eli->li_request_list) {
3748 			int err = 0;
3749 			int progress = 0;
3750 			elr = list_entry(pos, struct ext4_li_request,
3751 					 lr_request);
3752 
3753 			if (time_before(jiffies, elr->lr_next_sched)) {
3754 				if (time_before(elr->lr_next_sched, next_wakeup))
3755 					next_wakeup = elr->lr_next_sched;
3756 				continue;
3757 			}
3758 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3759 				if (sb_start_write_trylock(elr->lr_super)) {
3760 					progress = 1;
3761 					/*
3762 					 * We hold sb->s_umount, sb can not
3763 					 * be removed from the list, it is
3764 					 * now safe to drop li_list_mtx
3765 					 */
3766 					mutex_unlock(&eli->li_list_mtx);
3767 					err = ext4_run_li_request(elr);
3768 					sb_end_write(elr->lr_super);
3769 					mutex_lock(&eli->li_list_mtx);
3770 					n = pos->next;
3771 				}
3772 				up_read((&elr->lr_super->s_umount));
3773 			}
3774 			/* error, remove the lazy_init job */
3775 			if (err) {
3776 				ext4_remove_li_request(elr);
3777 				continue;
3778 			}
3779 			if (!progress) {
3780 				elr->lr_next_sched = jiffies +
3781 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3782 			}
3783 			if (time_before(elr->lr_next_sched, next_wakeup))
3784 				next_wakeup = elr->lr_next_sched;
3785 		}
3786 		mutex_unlock(&eli->li_list_mtx);
3787 
3788 		try_to_freeze();
3789 
3790 		cur = jiffies;
3791 		if ((time_after_eq(cur, next_wakeup)) ||
3792 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3793 			cond_resched();
3794 			continue;
3795 		}
3796 
3797 		schedule_timeout_interruptible(next_wakeup - cur);
3798 
3799 		if (kthread_should_stop()) {
3800 			ext4_clear_request_list();
3801 			goto exit_thread;
3802 		}
3803 	}
3804 
3805 exit_thread:
3806 	/*
3807 	 * It looks like the request list is empty, but we need
3808 	 * to check it under the li_list_mtx lock, to prevent any
3809 	 * additions into it, and of course we should lock ext4_li_mtx
3810 	 * to atomically free the list and ext4_li_info, because at
3811 	 * this point another ext4 filesystem could be registering
3812 	 * new one.
3813 	 */
3814 	mutex_lock(&ext4_li_mtx);
3815 	mutex_lock(&eli->li_list_mtx);
3816 	if (!list_empty(&eli->li_request_list)) {
3817 		mutex_unlock(&eli->li_list_mtx);
3818 		mutex_unlock(&ext4_li_mtx);
3819 		goto cont_thread;
3820 	}
3821 	mutex_unlock(&eli->li_list_mtx);
3822 	kfree(ext4_li_info);
3823 	ext4_li_info = NULL;
3824 	mutex_unlock(&ext4_li_mtx);
3825 
3826 	return 0;
3827 }
3828 
3829 static void ext4_clear_request_list(void)
3830 {
3831 	struct list_head *pos, *n;
3832 	struct ext4_li_request *elr;
3833 
3834 	mutex_lock(&ext4_li_info->li_list_mtx);
3835 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3836 		elr = list_entry(pos, struct ext4_li_request,
3837 				 lr_request);
3838 		ext4_remove_li_request(elr);
3839 	}
3840 	mutex_unlock(&ext4_li_info->li_list_mtx);
3841 }
3842 
3843 static int ext4_run_lazyinit_thread(void)
3844 {
3845 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3846 					 ext4_li_info, "ext4lazyinit");
3847 	if (IS_ERR(ext4_lazyinit_task)) {
3848 		int err = PTR_ERR(ext4_lazyinit_task);
3849 		ext4_clear_request_list();
3850 		kfree(ext4_li_info);
3851 		ext4_li_info = NULL;
3852 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3853 				 "initialization thread\n",
3854 				 err);
3855 		return err;
3856 	}
3857 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3858 	return 0;
3859 }
3860 
3861 /*
3862  * Check whether it make sense to run itable init. thread or not.
3863  * If there is at least one uninitialized inode table, return
3864  * corresponding group number, else the loop goes through all
3865  * groups and return total number of groups.
3866  */
3867 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3868 {
3869 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3870 	struct ext4_group_desc *gdp = NULL;
3871 
3872 	if (!ext4_has_group_desc_csum(sb))
3873 		return ngroups;
3874 
3875 	for (group = 0; group < ngroups; group++) {
3876 		gdp = ext4_get_group_desc(sb, group, NULL);
3877 		if (!gdp)
3878 			continue;
3879 
3880 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3881 			break;
3882 	}
3883 
3884 	return group;
3885 }
3886 
3887 static int ext4_li_info_new(void)
3888 {
3889 	struct ext4_lazy_init *eli = NULL;
3890 
3891 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3892 	if (!eli)
3893 		return -ENOMEM;
3894 
3895 	INIT_LIST_HEAD(&eli->li_request_list);
3896 	mutex_init(&eli->li_list_mtx);
3897 
3898 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3899 
3900 	ext4_li_info = eli;
3901 
3902 	return 0;
3903 }
3904 
3905 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3906 					    ext4_group_t start)
3907 {
3908 	struct ext4_li_request *elr;
3909 
3910 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3911 	if (!elr)
3912 		return NULL;
3913 
3914 	elr->lr_super = sb;
3915 	elr->lr_first_not_zeroed = start;
3916 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3917 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3918 		elr->lr_next_group = start;
3919 	} else {
3920 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3921 	}
3922 
3923 	/*
3924 	 * Randomize first schedule time of the request to
3925 	 * spread the inode table initialization requests
3926 	 * better.
3927 	 */
3928 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3929 	return elr;
3930 }
3931 
3932 int ext4_register_li_request(struct super_block *sb,
3933 			     ext4_group_t first_not_zeroed)
3934 {
3935 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3936 	struct ext4_li_request *elr = NULL;
3937 	ext4_group_t ngroups = sbi->s_groups_count;
3938 	int ret = 0;
3939 
3940 	mutex_lock(&ext4_li_mtx);
3941 	if (sbi->s_li_request != NULL) {
3942 		/*
3943 		 * Reset timeout so it can be computed again, because
3944 		 * s_li_wait_mult might have changed.
3945 		 */
3946 		sbi->s_li_request->lr_timeout = 0;
3947 		goto out;
3948 	}
3949 
3950 	if (sb_rdonly(sb) ||
3951 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3952 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
3953 		goto out;
3954 
3955 	elr = ext4_li_request_new(sb, first_not_zeroed);
3956 	if (!elr) {
3957 		ret = -ENOMEM;
3958 		goto out;
3959 	}
3960 
3961 	if (NULL == ext4_li_info) {
3962 		ret = ext4_li_info_new();
3963 		if (ret)
3964 			goto out;
3965 	}
3966 
3967 	mutex_lock(&ext4_li_info->li_list_mtx);
3968 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3969 	mutex_unlock(&ext4_li_info->li_list_mtx);
3970 
3971 	sbi->s_li_request = elr;
3972 	/*
3973 	 * set elr to NULL here since it has been inserted to
3974 	 * the request_list and the removal and free of it is
3975 	 * handled by ext4_clear_request_list from now on.
3976 	 */
3977 	elr = NULL;
3978 
3979 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3980 		ret = ext4_run_lazyinit_thread();
3981 		if (ret)
3982 			goto out;
3983 	}
3984 out:
3985 	mutex_unlock(&ext4_li_mtx);
3986 	if (ret)
3987 		kfree(elr);
3988 	return ret;
3989 }
3990 
3991 /*
3992  * We do not need to lock anything since this is called on
3993  * module unload.
3994  */
3995 static void ext4_destroy_lazyinit_thread(void)
3996 {
3997 	/*
3998 	 * If thread exited earlier
3999 	 * there's nothing to be done.
4000 	 */
4001 	if (!ext4_li_info || !ext4_lazyinit_task)
4002 		return;
4003 
4004 	kthread_stop(ext4_lazyinit_task);
4005 }
4006 
4007 static int set_journal_csum_feature_set(struct super_block *sb)
4008 {
4009 	int ret = 1;
4010 	int compat, incompat;
4011 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4012 
4013 	if (ext4_has_metadata_csum(sb)) {
4014 		/* journal checksum v3 */
4015 		compat = 0;
4016 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4017 	} else {
4018 		/* journal checksum v1 */
4019 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4020 		incompat = 0;
4021 	}
4022 
4023 	jbd2_journal_clear_features(sbi->s_journal,
4024 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4025 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4026 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4027 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4028 		ret = jbd2_journal_set_features(sbi->s_journal,
4029 				compat, 0,
4030 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4031 				incompat);
4032 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4033 		ret = jbd2_journal_set_features(sbi->s_journal,
4034 				compat, 0,
4035 				incompat);
4036 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4037 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4038 	} else {
4039 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4040 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4041 	}
4042 
4043 	return ret;
4044 }
4045 
4046 /*
4047  * Note: calculating the overhead so we can be compatible with
4048  * historical BSD practice is quite difficult in the face of
4049  * clusters/bigalloc.  This is because multiple metadata blocks from
4050  * different block group can end up in the same allocation cluster.
4051  * Calculating the exact overhead in the face of clustered allocation
4052  * requires either O(all block bitmaps) in memory or O(number of block
4053  * groups**2) in time.  We will still calculate the superblock for
4054  * older file systems --- and if we come across with a bigalloc file
4055  * system with zero in s_overhead_clusters the estimate will be close to
4056  * correct especially for very large cluster sizes --- but for newer
4057  * file systems, it's better to calculate this figure once at mkfs
4058  * time, and store it in the superblock.  If the superblock value is
4059  * present (even for non-bigalloc file systems), we will use it.
4060  */
4061 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4062 			  char *buf)
4063 {
4064 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4065 	struct ext4_group_desc	*gdp;
4066 	ext4_fsblk_t		first_block, last_block, b;
4067 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4068 	int			s, j, count = 0;
4069 	int			has_super = ext4_bg_has_super(sb, grp);
4070 
4071 	if (!ext4_has_feature_bigalloc(sb))
4072 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4073 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4074 			sbi->s_itb_per_group + 2);
4075 
4076 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4077 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4078 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4079 	for (i = 0; i < ngroups; i++) {
4080 		gdp = ext4_get_group_desc(sb, i, NULL);
4081 		b = ext4_block_bitmap(sb, gdp);
4082 		if (b >= first_block && b <= last_block) {
4083 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4084 			count++;
4085 		}
4086 		b = ext4_inode_bitmap(sb, gdp);
4087 		if (b >= first_block && b <= last_block) {
4088 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4089 			count++;
4090 		}
4091 		b = ext4_inode_table(sb, gdp);
4092 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4093 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4094 				int c = EXT4_B2C(sbi, b - first_block);
4095 				ext4_set_bit(c, buf);
4096 				count++;
4097 			}
4098 		if (i != grp)
4099 			continue;
4100 		s = 0;
4101 		if (ext4_bg_has_super(sb, grp)) {
4102 			ext4_set_bit(s++, buf);
4103 			count++;
4104 		}
4105 		j = ext4_bg_num_gdb(sb, grp);
4106 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4107 			ext4_error(sb, "Invalid number of block group "
4108 				   "descriptor blocks: %d", j);
4109 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4110 		}
4111 		count += j;
4112 		for (; j > 0; j--)
4113 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4114 	}
4115 	if (!count)
4116 		return 0;
4117 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4118 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4119 }
4120 
4121 /*
4122  * Compute the overhead and stash it in sbi->s_overhead
4123  */
4124 int ext4_calculate_overhead(struct super_block *sb)
4125 {
4126 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4127 	struct ext4_super_block *es = sbi->s_es;
4128 	struct inode *j_inode;
4129 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4130 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4131 	ext4_fsblk_t overhead = 0;
4132 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4133 
4134 	if (!buf)
4135 		return -ENOMEM;
4136 
4137 	/*
4138 	 * Compute the overhead (FS structures).  This is constant
4139 	 * for a given filesystem unless the number of block groups
4140 	 * changes so we cache the previous value until it does.
4141 	 */
4142 
4143 	/*
4144 	 * All of the blocks before first_data_block are overhead
4145 	 */
4146 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4147 
4148 	/*
4149 	 * Add the overhead found in each block group
4150 	 */
4151 	for (i = 0; i < ngroups; i++) {
4152 		int blks;
4153 
4154 		blks = count_overhead(sb, i, buf);
4155 		overhead += blks;
4156 		if (blks)
4157 			memset(buf, 0, PAGE_SIZE);
4158 		cond_resched();
4159 	}
4160 
4161 	/*
4162 	 * Add the internal journal blocks whether the journal has been
4163 	 * loaded or not
4164 	 */
4165 	if (sbi->s_journal && !sbi->s_journal_bdev)
4166 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4167 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4168 		/* j_inum for internal journal is non-zero */
4169 		j_inode = ext4_get_journal_inode(sb, j_inum);
4170 		if (j_inode) {
4171 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4172 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4173 			iput(j_inode);
4174 		} else {
4175 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4176 		}
4177 	}
4178 	sbi->s_overhead = overhead;
4179 	smp_wmb();
4180 	free_page((unsigned long) buf);
4181 	return 0;
4182 }
4183 
4184 static void ext4_set_resv_clusters(struct super_block *sb)
4185 {
4186 	ext4_fsblk_t resv_clusters;
4187 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4188 
4189 	/*
4190 	 * There's no need to reserve anything when we aren't using extents.
4191 	 * The space estimates are exact, there are no unwritten extents,
4192 	 * hole punching doesn't need new metadata... This is needed especially
4193 	 * to keep ext2/3 backward compatibility.
4194 	 */
4195 	if (!ext4_has_feature_extents(sb))
4196 		return;
4197 	/*
4198 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4199 	 * This should cover the situations where we can not afford to run
4200 	 * out of space like for example punch hole, or converting
4201 	 * unwritten extents in delalloc path. In most cases such
4202 	 * allocation would require 1, or 2 blocks, higher numbers are
4203 	 * very rare.
4204 	 */
4205 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4206 			 sbi->s_cluster_bits);
4207 
4208 	do_div(resv_clusters, 50);
4209 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4210 
4211 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4212 }
4213 
4214 static const char *ext4_quota_mode(struct super_block *sb)
4215 {
4216 #ifdef CONFIG_QUOTA
4217 	if (!ext4_quota_capable(sb))
4218 		return "none";
4219 
4220 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4221 		return "journalled";
4222 	else
4223 		return "writeback";
4224 #else
4225 	return "disabled";
4226 #endif
4227 }
4228 
4229 static void ext4_setup_csum_trigger(struct super_block *sb,
4230 				    enum ext4_journal_trigger_type type,
4231 				    void (*trigger)(
4232 					struct jbd2_buffer_trigger_type *type,
4233 					struct buffer_head *bh,
4234 					void *mapped_data,
4235 					size_t size))
4236 {
4237 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4238 
4239 	sbi->s_journal_triggers[type].sb = sb;
4240 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4241 }
4242 
4243 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4244 {
4245 	if (!sbi)
4246 		return;
4247 
4248 	kfree(sbi->s_blockgroup_lock);
4249 	fs_put_dax(sbi->s_daxdev, NULL);
4250 	kfree(sbi);
4251 }
4252 
4253 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4254 {
4255 	struct ext4_sb_info *sbi;
4256 
4257 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4258 	if (!sbi)
4259 		return NULL;
4260 
4261 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4262 					   NULL, NULL);
4263 
4264 	sbi->s_blockgroup_lock =
4265 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4266 
4267 	if (!sbi->s_blockgroup_lock)
4268 		goto err_out;
4269 
4270 	sb->s_fs_info = sbi;
4271 	sbi->s_sb = sb;
4272 	return sbi;
4273 err_out:
4274 	fs_put_dax(sbi->s_daxdev, NULL);
4275 	kfree(sbi);
4276 	return NULL;
4277 }
4278 
4279 static void ext4_set_def_opts(struct super_block *sb,
4280 			      struct ext4_super_block *es)
4281 {
4282 	unsigned long def_mount_opts;
4283 
4284 	/* Set defaults before we parse the mount options */
4285 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4286 	set_opt(sb, INIT_INODE_TABLE);
4287 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4288 		set_opt(sb, DEBUG);
4289 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4290 		set_opt(sb, GRPID);
4291 	if (def_mount_opts & EXT4_DEFM_UID16)
4292 		set_opt(sb, NO_UID32);
4293 	/* xattr user namespace & acls are now defaulted on */
4294 	set_opt(sb, XATTR_USER);
4295 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4296 	set_opt(sb, POSIX_ACL);
4297 #endif
4298 	if (ext4_has_feature_fast_commit(sb))
4299 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4300 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4301 	if (ext4_has_metadata_csum(sb))
4302 		set_opt(sb, JOURNAL_CHECKSUM);
4303 
4304 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4305 		set_opt(sb, JOURNAL_DATA);
4306 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4307 		set_opt(sb, ORDERED_DATA);
4308 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4309 		set_opt(sb, WRITEBACK_DATA);
4310 
4311 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4312 		set_opt(sb, ERRORS_PANIC);
4313 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4314 		set_opt(sb, ERRORS_CONT);
4315 	else
4316 		set_opt(sb, ERRORS_RO);
4317 	/* block_validity enabled by default; disable with noblock_validity */
4318 	set_opt(sb, BLOCK_VALIDITY);
4319 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4320 		set_opt(sb, DISCARD);
4321 
4322 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4323 		set_opt(sb, BARRIER);
4324 
4325 	/*
4326 	 * enable delayed allocation by default
4327 	 * Use -o nodelalloc to turn it off
4328 	 */
4329 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4330 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4331 		set_opt(sb, DELALLOC);
4332 
4333 	if (sb->s_blocksize == PAGE_SIZE)
4334 		set_opt(sb, DIOREAD_NOLOCK);
4335 }
4336 
4337 static int ext4_handle_clustersize(struct super_block *sb)
4338 {
4339 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4340 	struct ext4_super_block *es = sbi->s_es;
4341 	int clustersize;
4342 
4343 	/* Handle clustersize */
4344 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4345 	if (ext4_has_feature_bigalloc(sb)) {
4346 		if (clustersize < sb->s_blocksize) {
4347 			ext4_msg(sb, KERN_ERR,
4348 				 "cluster size (%d) smaller than "
4349 				 "block size (%lu)", clustersize, sb->s_blocksize);
4350 			return -EINVAL;
4351 		}
4352 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4353 			le32_to_cpu(es->s_log_block_size);
4354 		sbi->s_clusters_per_group =
4355 			le32_to_cpu(es->s_clusters_per_group);
4356 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4357 			ext4_msg(sb, KERN_ERR,
4358 				 "#clusters per group too big: %lu",
4359 				 sbi->s_clusters_per_group);
4360 			return -EINVAL;
4361 		}
4362 		if (sbi->s_blocks_per_group !=
4363 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4364 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4365 				 "clusters per group (%lu) inconsistent",
4366 				 sbi->s_blocks_per_group,
4367 				 sbi->s_clusters_per_group);
4368 			return -EINVAL;
4369 		}
4370 	} else {
4371 		if (clustersize != sb->s_blocksize) {
4372 			ext4_msg(sb, KERN_ERR,
4373 				 "fragment/cluster size (%d) != "
4374 				 "block size (%lu)", clustersize, sb->s_blocksize);
4375 			return -EINVAL;
4376 		}
4377 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4378 			ext4_msg(sb, KERN_ERR,
4379 				 "#blocks per group too big: %lu",
4380 				 sbi->s_blocks_per_group);
4381 			return -EINVAL;
4382 		}
4383 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4384 		sbi->s_cluster_bits = 0;
4385 	}
4386 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4387 
4388 	/* Do we have standard group size of clustersize * 8 blocks ? */
4389 	if (sbi->s_blocks_per_group == clustersize << 3)
4390 		set_opt2(sb, STD_GROUP_SIZE);
4391 
4392 	return 0;
4393 }
4394 
4395 static void ext4_fast_commit_init(struct super_block *sb)
4396 {
4397 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4398 
4399 	/* Initialize fast commit stuff */
4400 	atomic_set(&sbi->s_fc_subtid, 0);
4401 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4402 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4403 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4404 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4405 	sbi->s_fc_bytes = 0;
4406 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4407 	sbi->s_fc_ineligible_tid = 0;
4408 	spin_lock_init(&sbi->s_fc_lock);
4409 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4410 	sbi->s_fc_replay_state.fc_regions = NULL;
4411 	sbi->s_fc_replay_state.fc_regions_size = 0;
4412 	sbi->s_fc_replay_state.fc_regions_used = 0;
4413 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4414 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4415 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4416 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4417 }
4418 
4419 static int ext4_inode_info_init(struct super_block *sb,
4420 				struct ext4_super_block *es)
4421 {
4422 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4423 
4424 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4425 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4426 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4427 	} else {
4428 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4429 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4430 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4431 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4432 				 sbi->s_first_ino);
4433 			return -EINVAL;
4434 		}
4435 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4436 		    (!is_power_of_2(sbi->s_inode_size)) ||
4437 		    (sbi->s_inode_size > sb->s_blocksize)) {
4438 			ext4_msg(sb, KERN_ERR,
4439 			       "unsupported inode size: %d",
4440 			       sbi->s_inode_size);
4441 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4442 			return -EINVAL;
4443 		}
4444 		/*
4445 		 * i_atime_extra is the last extra field available for
4446 		 * [acm]times in struct ext4_inode. Checking for that
4447 		 * field should suffice to ensure we have extra space
4448 		 * for all three.
4449 		 */
4450 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4451 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4452 			sb->s_time_gran = 1;
4453 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4454 		} else {
4455 			sb->s_time_gran = NSEC_PER_SEC;
4456 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4457 		}
4458 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4459 	}
4460 
4461 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4462 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4463 			EXT4_GOOD_OLD_INODE_SIZE;
4464 		if (ext4_has_feature_extra_isize(sb)) {
4465 			unsigned v, max = (sbi->s_inode_size -
4466 					   EXT4_GOOD_OLD_INODE_SIZE);
4467 
4468 			v = le16_to_cpu(es->s_want_extra_isize);
4469 			if (v > max) {
4470 				ext4_msg(sb, KERN_ERR,
4471 					 "bad s_want_extra_isize: %d", v);
4472 				return -EINVAL;
4473 			}
4474 			if (sbi->s_want_extra_isize < v)
4475 				sbi->s_want_extra_isize = v;
4476 
4477 			v = le16_to_cpu(es->s_min_extra_isize);
4478 			if (v > max) {
4479 				ext4_msg(sb, KERN_ERR,
4480 					 "bad s_min_extra_isize: %d", v);
4481 				return -EINVAL;
4482 			}
4483 			if (sbi->s_want_extra_isize < v)
4484 				sbi->s_want_extra_isize = v;
4485 		}
4486 	}
4487 
4488 	return 0;
4489 }
4490 
4491 #if IS_ENABLED(CONFIG_UNICODE)
4492 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4493 {
4494 	const struct ext4_sb_encodings *encoding_info;
4495 	struct unicode_map *encoding;
4496 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4497 
4498 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4499 		return 0;
4500 
4501 	encoding_info = ext4_sb_read_encoding(es);
4502 	if (!encoding_info) {
4503 		ext4_msg(sb, KERN_ERR,
4504 			"Encoding requested by superblock is unknown");
4505 		return -EINVAL;
4506 	}
4507 
4508 	encoding = utf8_load(encoding_info->version);
4509 	if (IS_ERR(encoding)) {
4510 		ext4_msg(sb, KERN_ERR,
4511 			"can't mount with superblock charset: %s-%u.%u.%u "
4512 			"not supported by the kernel. flags: 0x%x.",
4513 			encoding_info->name,
4514 			unicode_major(encoding_info->version),
4515 			unicode_minor(encoding_info->version),
4516 			unicode_rev(encoding_info->version),
4517 			encoding_flags);
4518 		return -EINVAL;
4519 	}
4520 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4521 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4522 		unicode_major(encoding_info->version),
4523 		unicode_minor(encoding_info->version),
4524 		unicode_rev(encoding_info->version),
4525 		encoding_flags);
4526 
4527 	sb->s_encoding = encoding;
4528 	sb->s_encoding_flags = encoding_flags;
4529 
4530 	return 0;
4531 }
4532 #else
4533 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4534 {
4535 	return 0;
4536 }
4537 #endif
4538 
4539 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4540 {
4541 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4542 
4543 	/* Warn if metadata_csum and gdt_csum are both set. */
4544 	if (ext4_has_feature_metadata_csum(sb) &&
4545 	    ext4_has_feature_gdt_csum(sb))
4546 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4547 			     "redundant flags; please run fsck.");
4548 
4549 	/* Check for a known checksum algorithm */
4550 	if (!ext4_verify_csum_type(sb, es)) {
4551 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4552 			 "unknown checksum algorithm.");
4553 		return -EINVAL;
4554 	}
4555 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4556 				ext4_orphan_file_block_trigger);
4557 
4558 	/* Load the checksum driver */
4559 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4560 	if (IS_ERR(sbi->s_chksum_driver)) {
4561 		int ret = PTR_ERR(sbi->s_chksum_driver);
4562 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4563 		sbi->s_chksum_driver = NULL;
4564 		return ret;
4565 	}
4566 
4567 	/* Check superblock checksum */
4568 	if (!ext4_superblock_csum_verify(sb, es)) {
4569 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4570 			 "invalid superblock checksum.  Run e2fsck?");
4571 		return -EFSBADCRC;
4572 	}
4573 
4574 	/* Precompute checksum seed for all metadata */
4575 	if (ext4_has_feature_csum_seed(sb))
4576 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4577 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4578 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4579 					       sizeof(es->s_uuid));
4580 	return 0;
4581 }
4582 
4583 static int ext4_check_feature_compatibility(struct super_block *sb,
4584 					    struct ext4_super_block *es,
4585 					    int silent)
4586 {
4587 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4588 	    (ext4_has_compat_features(sb) ||
4589 	     ext4_has_ro_compat_features(sb) ||
4590 	     ext4_has_incompat_features(sb)))
4591 		ext4_msg(sb, KERN_WARNING,
4592 		       "feature flags set on rev 0 fs, "
4593 		       "running e2fsck is recommended");
4594 
4595 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4596 		set_opt2(sb, HURD_COMPAT);
4597 		if (ext4_has_feature_64bit(sb)) {
4598 			ext4_msg(sb, KERN_ERR,
4599 				 "The Hurd can't support 64-bit file systems");
4600 			return -EINVAL;
4601 		}
4602 
4603 		/*
4604 		 * ea_inode feature uses l_i_version field which is not
4605 		 * available in HURD_COMPAT mode.
4606 		 */
4607 		if (ext4_has_feature_ea_inode(sb)) {
4608 			ext4_msg(sb, KERN_ERR,
4609 				 "ea_inode feature is not supported for Hurd");
4610 			return -EINVAL;
4611 		}
4612 	}
4613 
4614 	if (IS_EXT2_SB(sb)) {
4615 		if (ext2_feature_set_ok(sb))
4616 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4617 				 "using the ext4 subsystem");
4618 		else {
4619 			/*
4620 			 * If we're probing be silent, if this looks like
4621 			 * it's actually an ext[34] filesystem.
4622 			 */
4623 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4624 				return -EINVAL;
4625 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4626 				 "to feature incompatibilities");
4627 			return -EINVAL;
4628 		}
4629 	}
4630 
4631 	if (IS_EXT3_SB(sb)) {
4632 		if (ext3_feature_set_ok(sb))
4633 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4634 				 "using the ext4 subsystem");
4635 		else {
4636 			/*
4637 			 * If we're probing be silent, if this looks like
4638 			 * it's actually an ext4 filesystem.
4639 			 */
4640 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4641 				return -EINVAL;
4642 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4643 				 "to feature incompatibilities");
4644 			return -EINVAL;
4645 		}
4646 	}
4647 
4648 	/*
4649 	 * Check feature flags regardless of the revision level, since we
4650 	 * previously didn't change the revision level when setting the flags,
4651 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4652 	 */
4653 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4654 		return -EINVAL;
4655 
4656 	return 0;
4657 }
4658 
4659 static int ext4_geometry_check(struct super_block *sb,
4660 			       struct ext4_super_block *es)
4661 {
4662 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4663 	__u64 blocks_count;
4664 
4665 	/* check blocks count against device size */
4666 	blocks_count = sb_bdev_nr_blocks(sb);
4667 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4668 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4669 		       "exceeds size of device (%llu blocks)",
4670 		       ext4_blocks_count(es), blocks_count);
4671 		return -EINVAL;
4672 	}
4673 
4674 	/*
4675 	 * It makes no sense for the first data block to be beyond the end
4676 	 * of the filesystem.
4677 	 */
4678 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4679 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4680 			 "block %u is beyond end of filesystem (%llu)",
4681 			 le32_to_cpu(es->s_first_data_block),
4682 			 ext4_blocks_count(es));
4683 		return -EINVAL;
4684 	}
4685 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4686 	    (sbi->s_cluster_ratio == 1)) {
4687 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4688 			 "block is 0 with a 1k block and cluster size");
4689 		return -EINVAL;
4690 	}
4691 
4692 	blocks_count = (ext4_blocks_count(es) -
4693 			le32_to_cpu(es->s_first_data_block) +
4694 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4695 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4696 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4697 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4698 		       "(block count %llu, first data block %u, "
4699 		       "blocks per group %lu)", blocks_count,
4700 		       ext4_blocks_count(es),
4701 		       le32_to_cpu(es->s_first_data_block),
4702 		       EXT4_BLOCKS_PER_GROUP(sb));
4703 		return -EINVAL;
4704 	}
4705 	sbi->s_groups_count = blocks_count;
4706 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4707 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4708 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4709 	    le32_to_cpu(es->s_inodes_count)) {
4710 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4711 			 le32_to_cpu(es->s_inodes_count),
4712 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4713 		return -EINVAL;
4714 	}
4715 
4716 	return 0;
4717 }
4718 
4719 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
4720 {
4721 	struct buffer_head **group_desc;
4722 	int i;
4723 
4724 	rcu_read_lock();
4725 	group_desc = rcu_dereference(sbi->s_group_desc);
4726 	for (i = 0; i < sbi->s_gdb_count; i++)
4727 		brelse(group_desc[i]);
4728 	kvfree(group_desc);
4729 	rcu_read_unlock();
4730 }
4731 
4732 static int ext4_group_desc_init(struct super_block *sb,
4733 				struct ext4_super_block *es,
4734 				ext4_fsblk_t logical_sb_block,
4735 				ext4_group_t *first_not_zeroed)
4736 {
4737 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4738 	unsigned int db_count;
4739 	ext4_fsblk_t block;
4740 	int ret;
4741 	int i;
4742 
4743 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4744 		   EXT4_DESC_PER_BLOCK(sb);
4745 	if (ext4_has_feature_meta_bg(sb)) {
4746 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4747 			ext4_msg(sb, KERN_WARNING,
4748 				 "first meta block group too large: %u "
4749 				 "(group descriptor block count %u)",
4750 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4751 			return -EINVAL;
4752 		}
4753 	}
4754 	rcu_assign_pointer(sbi->s_group_desc,
4755 			   kvmalloc_array(db_count,
4756 					  sizeof(struct buffer_head *),
4757 					  GFP_KERNEL));
4758 	if (sbi->s_group_desc == NULL) {
4759 		ext4_msg(sb, KERN_ERR, "not enough memory");
4760 		return -ENOMEM;
4761 	}
4762 
4763 	bgl_lock_init(sbi->s_blockgroup_lock);
4764 
4765 	/* Pre-read the descriptors into the buffer cache */
4766 	for (i = 0; i < db_count; i++) {
4767 		block = descriptor_loc(sb, logical_sb_block, i);
4768 		ext4_sb_breadahead_unmovable(sb, block);
4769 	}
4770 
4771 	for (i = 0; i < db_count; i++) {
4772 		struct buffer_head *bh;
4773 
4774 		block = descriptor_loc(sb, logical_sb_block, i);
4775 		bh = ext4_sb_bread_unmovable(sb, block);
4776 		if (IS_ERR(bh)) {
4777 			ext4_msg(sb, KERN_ERR,
4778 			       "can't read group descriptor %d", i);
4779 			sbi->s_gdb_count = i;
4780 			ret = PTR_ERR(bh);
4781 			goto out;
4782 		}
4783 		rcu_read_lock();
4784 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4785 		rcu_read_unlock();
4786 	}
4787 	sbi->s_gdb_count = db_count;
4788 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4789 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4790 		ret = -EFSCORRUPTED;
4791 		goto out;
4792 	}
4793 	return 0;
4794 out:
4795 	ext4_group_desc_free(sbi);
4796 	return ret;
4797 }
4798 
4799 static int ext4_load_and_init_journal(struct super_block *sb,
4800 				      struct ext4_super_block *es,
4801 				      struct ext4_fs_context *ctx)
4802 {
4803 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4804 	int err;
4805 
4806 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4807 	if (err)
4808 		return err;
4809 
4810 	if (ext4_has_feature_64bit(sb) &&
4811 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4812 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4813 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4814 		goto out;
4815 	}
4816 
4817 	if (!set_journal_csum_feature_set(sb)) {
4818 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4819 			 "feature set");
4820 		goto out;
4821 	}
4822 
4823 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4824 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4825 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4826 		ext4_msg(sb, KERN_ERR,
4827 			"Failed to set fast commit journal feature");
4828 		goto out;
4829 	}
4830 
4831 	/* We have now updated the journal if required, so we can
4832 	 * validate the data journaling mode. */
4833 	switch (test_opt(sb, DATA_FLAGS)) {
4834 	case 0:
4835 		/* No mode set, assume a default based on the journal
4836 		 * capabilities: ORDERED_DATA if the journal can
4837 		 * cope, else JOURNAL_DATA
4838 		 */
4839 		if (jbd2_journal_check_available_features
4840 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4841 			set_opt(sb, ORDERED_DATA);
4842 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4843 		} else {
4844 			set_opt(sb, JOURNAL_DATA);
4845 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4846 		}
4847 		break;
4848 
4849 	case EXT4_MOUNT_ORDERED_DATA:
4850 	case EXT4_MOUNT_WRITEBACK_DATA:
4851 		if (!jbd2_journal_check_available_features
4852 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4853 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4854 			       "requested data journaling mode");
4855 			goto out;
4856 		}
4857 		break;
4858 	default:
4859 		break;
4860 	}
4861 
4862 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4863 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4864 		ext4_msg(sb, KERN_ERR, "can't mount with "
4865 			"journal_async_commit in data=ordered mode");
4866 		goto out;
4867 	}
4868 
4869 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4870 
4871 	sbi->s_journal->j_submit_inode_data_buffers =
4872 		ext4_journal_submit_inode_data_buffers;
4873 	sbi->s_journal->j_finish_inode_data_buffers =
4874 		ext4_journal_finish_inode_data_buffers;
4875 
4876 	return 0;
4877 
4878 out:
4879 	/* flush s_error_work before journal destroy. */
4880 	flush_work(&sbi->s_error_work);
4881 	jbd2_journal_destroy(sbi->s_journal);
4882 	sbi->s_journal = NULL;
4883 	return -EINVAL;
4884 }
4885 
4886 static int ext4_journal_data_mode_check(struct super_block *sb)
4887 {
4888 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4889 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4890 			    "data=journal disables delayed allocation, "
4891 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4892 		/* can't mount with both data=journal and dioread_nolock. */
4893 		clear_opt(sb, DIOREAD_NOLOCK);
4894 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4895 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4896 			ext4_msg(sb, KERN_ERR, "can't mount with "
4897 				 "both data=journal and delalloc");
4898 			return -EINVAL;
4899 		}
4900 		if (test_opt(sb, DAX_ALWAYS)) {
4901 			ext4_msg(sb, KERN_ERR, "can't mount with "
4902 				 "both data=journal and dax");
4903 			return -EINVAL;
4904 		}
4905 		if (ext4_has_feature_encrypt(sb)) {
4906 			ext4_msg(sb, KERN_WARNING,
4907 				 "encrypted files will use data=ordered "
4908 				 "instead of data journaling mode");
4909 		}
4910 		if (test_opt(sb, DELALLOC))
4911 			clear_opt(sb, DELALLOC);
4912 	} else {
4913 		sb->s_iflags |= SB_I_CGROUPWB;
4914 	}
4915 
4916 	return 0;
4917 }
4918 
4919 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
4920 			   int silent)
4921 {
4922 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4923 	struct ext4_super_block *es;
4924 	ext4_fsblk_t logical_sb_block;
4925 	unsigned long offset = 0;
4926 	struct buffer_head *bh;
4927 	int ret = -EINVAL;
4928 	int blocksize;
4929 
4930 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4931 	if (!blocksize) {
4932 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4933 		return -EINVAL;
4934 	}
4935 
4936 	/*
4937 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4938 	 * block sizes.  We need to calculate the offset from buffer start.
4939 	 */
4940 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4941 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4942 		offset = do_div(logical_sb_block, blocksize);
4943 	} else {
4944 		logical_sb_block = sbi->s_sb_block;
4945 	}
4946 
4947 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4948 	if (IS_ERR(bh)) {
4949 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4950 		return PTR_ERR(bh);
4951 	}
4952 	/*
4953 	 * Note: s_es must be initialized as soon as possible because
4954 	 *       some ext4 macro-instructions depend on its value
4955 	 */
4956 	es = (struct ext4_super_block *) (bh->b_data + offset);
4957 	sbi->s_es = es;
4958 	sb->s_magic = le16_to_cpu(es->s_magic);
4959 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
4960 		if (!silent)
4961 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4962 		goto out;
4963 	}
4964 
4965 	if (le32_to_cpu(es->s_log_block_size) >
4966 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4967 		ext4_msg(sb, KERN_ERR,
4968 			 "Invalid log block size: %u",
4969 			 le32_to_cpu(es->s_log_block_size));
4970 		goto out;
4971 	}
4972 	if (le32_to_cpu(es->s_log_cluster_size) >
4973 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4974 		ext4_msg(sb, KERN_ERR,
4975 			 "Invalid log cluster size: %u",
4976 			 le32_to_cpu(es->s_log_cluster_size));
4977 		goto out;
4978 	}
4979 
4980 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4981 
4982 	/*
4983 	 * If the default block size is not the same as the real block size,
4984 	 * we need to reload it.
4985 	 */
4986 	if (sb->s_blocksize == blocksize) {
4987 		*lsb = logical_sb_block;
4988 		sbi->s_sbh = bh;
4989 		return 0;
4990 	}
4991 
4992 	/*
4993 	 * bh must be released before kill_bdev(), otherwise
4994 	 * it won't be freed and its page also. kill_bdev()
4995 	 * is called by sb_set_blocksize().
4996 	 */
4997 	brelse(bh);
4998 	/* Validate the filesystem blocksize */
4999 	if (!sb_set_blocksize(sb, blocksize)) {
5000 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5001 				blocksize);
5002 		bh = NULL;
5003 		goto out;
5004 	}
5005 
5006 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5007 	offset = do_div(logical_sb_block, blocksize);
5008 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5009 	if (IS_ERR(bh)) {
5010 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5011 		ret = PTR_ERR(bh);
5012 		bh = NULL;
5013 		goto out;
5014 	}
5015 	es = (struct ext4_super_block *)(bh->b_data + offset);
5016 	sbi->s_es = es;
5017 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5018 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5019 		goto out;
5020 	}
5021 	*lsb = logical_sb_block;
5022 	sbi->s_sbh = bh;
5023 	return 0;
5024 out:
5025 	brelse(bh);
5026 	return ret;
5027 }
5028 
5029 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5030 {
5031 	struct ext4_super_block *es = NULL;
5032 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5033 	struct flex_groups **flex_groups;
5034 	ext4_fsblk_t block;
5035 	ext4_fsblk_t logical_sb_block;
5036 	struct inode *root;
5037 	int ret = -ENOMEM;
5038 	unsigned int i;
5039 	int needs_recovery, has_huge_files;
5040 	int err = 0;
5041 	ext4_group_t first_not_zeroed;
5042 	struct ext4_fs_context *ctx = fc->fs_private;
5043 	int silent = fc->sb_flags & SB_SILENT;
5044 
5045 	/* Set defaults for the variables that will be set during parsing */
5046 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5047 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5048 
5049 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5050 	sbi->s_sectors_written_start =
5051 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5052 
5053 	/* -EINVAL is default */
5054 	ret = -EINVAL;
5055 	err = ext4_load_super(sb, &logical_sb_block, silent);
5056 	if (err)
5057 		goto out_fail;
5058 
5059 	es = sbi->s_es;
5060 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5061 
5062 	err = ext4_init_metadata_csum(sb, es);
5063 	if (err)
5064 		goto failed_mount;
5065 
5066 	ext4_set_def_opts(sb, es);
5067 
5068 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5069 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5070 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5071 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5072 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5073 
5074 	/*
5075 	 * set default s_li_wait_mult for lazyinit, for the case there is
5076 	 * no mount option specified.
5077 	 */
5078 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5079 
5080 	if (ext4_inode_info_init(sb, es))
5081 		goto failed_mount;
5082 
5083 	err = parse_apply_sb_mount_options(sb, ctx);
5084 	if (err < 0)
5085 		goto failed_mount;
5086 
5087 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5088 
5089 	err = ext4_check_opt_consistency(fc, sb);
5090 	if (err < 0)
5091 		goto failed_mount;
5092 
5093 	ext4_apply_options(fc, sb);
5094 
5095 	if (ext4_encoding_init(sb, es))
5096 		goto failed_mount;
5097 
5098 	if (ext4_journal_data_mode_check(sb))
5099 		goto failed_mount;
5100 
5101 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5102 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5103 
5104 	/* i_version is always enabled now */
5105 	sb->s_flags |= SB_I_VERSION;
5106 
5107 	if (ext4_check_feature_compatibility(sb, es, silent))
5108 		goto failed_mount;
5109 
5110 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
5111 		ext4_msg(sb, KERN_ERR,
5112 			 "Number of reserved GDT blocks insanely large: %d",
5113 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
5114 		goto failed_mount;
5115 	}
5116 
5117 	if (sbi->s_daxdev) {
5118 		if (sb->s_blocksize == PAGE_SIZE)
5119 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
5120 		else
5121 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
5122 	}
5123 
5124 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
5125 		if (ext4_has_feature_inline_data(sb)) {
5126 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
5127 					" that may contain inline data");
5128 			goto failed_mount;
5129 		}
5130 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
5131 			ext4_msg(sb, KERN_ERR,
5132 				"DAX unsupported by block device.");
5133 			goto failed_mount;
5134 		}
5135 	}
5136 
5137 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
5138 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
5139 			 es->s_encryption_level);
5140 		goto failed_mount;
5141 	}
5142 
5143 	has_huge_files = ext4_has_feature_huge_file(sb);
5144 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5145 						      has_huge_files);
5146 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5147 
5148 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5149 	if (ext4_has_feature_64bit(sb)) {
5150 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5151 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5152 		    !is_power_of_2(sbi->s_desc_size)) {
5153 			ext4_msg(sb, KERN_ERR,
5154 			       "unsupported descriptor size %lu",
5155 			       sbi->s_desc_size);
5156 			goto failed_mount;
5157 		}
5158 	} else
5159 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5160 
5161 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5162 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5163 
5164 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5165 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5166 		if (!silent)
5167 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5168 		goto failed_mount;
5169 	}
5170 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5171 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5172 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5173 			 sbi->s_inodes_per_group);
5174 		goto failed_mount;
5175 	}
5176 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5177 					sbi->s_inodes_per_block;
5178 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5179 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5180 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5181 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5182 
5183 	for (i = 0; i < 4; i++)
5184 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5185 	sbi->s_def_hash_version = es->s_def_hash_version;
5186 	if (ext4_has_feature_dir_index(sb)) {
5187 		i = le32_to_cpu(es->s_flags);
5188 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5189 			sbi->s_hash_unsigned = 3;
5190 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5191 #ifdef __CHAR_UNSIGNED__
5192 			if (!sb_rdonly(sb))
5193 				es->s_flags |=
5194 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5195 			sbi->s_hash_unsigned = 3;
5196 #else
5197 			if (!sb_rdonly(sb))
5198 				es->s_flags |=
5199 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5200 #endif
5201 		}
5202 	}
5203 
5204 	if (ext4_handle_clustersize(sb))
5205 		goto failed_mount;
5206 
5207 	/*
5208 	 * Test whether we have more sectors than will fit in sector_t,
5209 	 * and whether the max offset is addressable by the page cache.
5210 	 */
5211 	err = generic_check_addressable(sb->s_blocksize_bits,
5212 					ext4_blocks_count(es));
5213 	if (err) {
5214 		ext4_msg(sb, KERN_ERR, "filesystem"
5215 			 " too large to mount safely on this system");
5216 		goto failed_mount;
5217 	}
5218 
5219 	if (ext4_geometry_check(sb, es))
5220 		goto failed_mount;
5221 
5222 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5223 	if (err)
5224 		goto failed_mount;
5225 
5226 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5227 	spin_lock_init(&sbi->s_error_lock);
5228 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5229 
5230 	/* Register extent status tree shrinker */
5231 	if (ext4_es_register_shrinker(sbi))
5232 		goto failed_mount3;
5233 
5234 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5235 	sbi->s_extent_max_zeroout_kb = 32;
5236 
5237 	/*
5238 	 * set up enough so that it can read an inode
5239 	 */
5240 	sb->s_op = &ext4_sops;
5241 	sb->s_export_op = &ext4_export_ops;
5242 	sb->s_xattr = ext4_xattr_handlers;
5243 #ifdef CONFIG_FS_ENCRYPTION
5244 	sb->s_cop = &ext4_cryptops;
5245 #endif
5246 #ifdef CONFIG_FS_VERITY
5247 	sb->s_vop = &ext4_verityops;
5248 #endif
5249 #ifdef CONFIG_QUOTA
5250 	sb->dq_op = &ext4_quota_operations;
5251 	if (ext4_has_feature_quota(sb))
5252 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5253 	else
5254 		sb->s_qcop = &ext4_qctl_operations;
5255 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5256 #endif
5257 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5258 
5259 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5260 	mutex_init(&sbi->s_orphan_lock);
5261 
5262 	ext4_fast_commit_init(sb);
5263 
5264 	sb->s_root = NULL;
5265 
5266 	needs_recovery = (es->s_last_orphan != 0 ||
5267 			  ext4_has_feature_orphan_present(sb) ||
5268 			  ext4_has_feature_journal_needs_recovery(sb));
5269 
5270 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5271 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5272 			goto failed_mount3a;
5273 
5274 	/*
5275 	 * The first inode we look at is the journal inode.  Don't try
5276 	 * root first: it may be modified in the journal!
5277 	 */
5278 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5279 		err = ext4_load_and_init_journal(sb, es, ctx);
5280 		if (err)
5281 			goto failed_mount3a;
5282 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5283 		   ext4_has_feature_journal_needs_recovery(sb)) {
5284 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5285 		       "suppressed and not mounted read-only");
5286 		goto failed_mount3a;
5287 	} else {
5288 		/* Nojournal mode, all journal mount options are illegal */
5289 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5290 			ext4_msg(sb, KERN_ERR, "can't mount with "
5291 				 "journal_checksum, fs mounted w/o journal");
5292 			goto failed_mount3a;
5293 		}
5294 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5295 			ext4_msg(sb, KERN_ERR, "can't mount with "
5296 				 "journal_async_commit, fs mounted w/o journal");
5297 			goto failed_mount3a;
5298 		}
5299 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5300 			ext4_msg(sb, KERN_ERR, "can't mount with "
5301 				 "commit=%lu, fs mounted w/o journal",
5302 				 sbi->s_commit_interval / HZ);
5303 			goto failed_mount3a;
5304 		}
5305 		if (EXT4_MOUNT_DATA_FLAGS &
5306 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5307 			ext4_msg(sb, KERN_ERR, "can't mount with "
5308 				 "data=, fs mounted w/o journal");
5309 			goto failed_mount3a;
5310 		}
5311 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5312 		clear_opt(sb, JOURNAL_CHECKSUM);
5313 		clear_opt(sb, DATA_FLAGS);
5314 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5315 		sbi->s_journal = NULL;
5316 		needs_recovery = 0;
5317 	}
5318 
5319 	if (!test_opt(sb, NO_MBCACHE)) {
5320 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5321 		if (!sbi->s_ea_block_cache) {
5322 			ext4_msg(sb, KERN_ERR,
5323 				 "Failed to create ea_block_cache");
5324 			goto failed_mount_wq;
5325 		}
5326 
5327 		if (ext4_has_feature_ea_inode(sb)) {
5328 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5329 			if (!sbi->s_ea_inode_cache) {
5330 				ext4_msg(sb, KERN_ERR,
5331 					 "Failed to create ea_inode_cache");
5332 				goto failed_mount_wq;
5333 			}
5334 		}
5335 	}
5336 
5337 	if (ext4_has_feature_verity(sb) && sb->s_blocksize != PAGE_SIZE) {
5338 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5339 		goto failed_mount_wq;
5340 	}
5341 
5342 	/*
5343 	 * Get the # of file system overhead blocks from the
5344 	 * superblock if present.
5345 	 */
5346 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5347 	/* ignore the precalculated value if it is ridiculous */
5348 	if (sbi->s_overhead > ext4_blocks_count(es))
5349 		sbi->s_overhead = 0;
5350 	/*
5351 	 * If the bigalloc feature is not enabled recalculating the
5352 	 * overhead doesn't take long, so we might as well just redo
5353 	 * it to make sure we are using the correct value.
5354 	 */
5355 	if (!ext4_has_feature_bigalloc(sb))
5356 		sbi->s_overhead = 0;
5357 	if (sbi->s_overhead == 0) {
5358 		err = ext4_calculate_overhead(sb);
5359 		if (err)
5360 			goto failed_mount_wq;
5361 	}
5362 
5363 	/*
5364 	 * The maximum number of concurrent works can be high and
5365 	 * concurrency isn't really necessary.  Limit it to 1.
5366 	 */
5367 	EXT4_SB(sb)->rsv_conversion_wq =
5368 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5369 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5370 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5371 		ret = -ENOMEM;
5372 		goto failed_mount4;
5373 	}
5374 
5375 	/*
5376 	 * The jbd2_journal_load will have done any necessary log recovery,
5377 	 * so we can safely mount the rest of the filesystem now.
5378 	 */
5379 
5380 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5381 	if (IS_ERR(root)) {
5382 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5383 		ret = PTR_ERR(root);
5384 		root = NULL;
5385 		goto failed_mount4;
5386 	}
5387 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5388 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5389 		iput(root);
5390 		goto failed_mount4;
5391 	}
5392 
5393 	sb->s_root = d_make_root(root);
5394 	if (!sb->s_root) {
5395 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5396 		ret = -ENOMEM;
5397 		goto failed_mount4;
5398 	}
5399 
5400 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5401 	if (ret == -EROFS) {
5402 		sb->s_flags |= SB_RDONLY;
5403 		ret = 0;
5404 	} else if (ret)
5405 		goto failed_mount4a;
5406 
5407 	ext4_set_resv_clusters(sb);
5408 
5409 	if (test_opt(sb, BLOCK_VALIDITY)) {
5410 		err = ext4_setup_system_zone(sb);
5411 		if (err) {
5412 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5413 				 "zone (%d)", err);
5414 			goto failed_mount4a;
5415 		}
5416 	}
5417 	ext4_fc_replay_cleanup(sb);
5418 
5419 	ext4_ext_init(sb);
5420 
5421 	/*
5422 	 * Enable optimize_scan if number of groups is > threshold. This can be
5423 	 * turned off by passing "mb_optimize_scan=0". This can also be
5424 	 * turned on forcefully by passing "mb_optimize_scan=1".
5425 	 */
5426 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5427 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5428 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5429 		else
5430 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5431 	}
5432 
5433 	err = ext4_mb_init(sb);
5434 	if (err) {
5435 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5436 			 err);
5437 		goto failed_mount5;
5438 	}
5439 
5440 	/*
5441 	 * We can only set up the journal commit callback once
5442 	 * mballoc is initialized
5443 	 */
5444 	if (sbi->s_journal)
5445 		sbi->s_journal->j_commit_callback =
5446 			ext4_journal_commit_callback;
5447 
5448 	block = ext4_count_free_clusters(sb);
5449 	ext4_free_blocks_count_set(sbi->s_es,
5450 				   EXT4_C2B(sbi, block));
5451 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5452 				  GFP_KERNEL);
5453 	if (!err) {
5454 		unsigned long freei = ext4_count_free_inodes(sb);
5455 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5456 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5457 					  GFP_KERNEL);
5458 	}
5459 	if (!err)
5460 		err = percpu_counter_init(&sbi->s_dirs_counter,
5461 					  ext4_count_dirs(sb), GFP_KERNEL);
5462 	if (!err)
5463 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5464 					  GFP_KERNEL);
5465 	if (!err)
5466 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5467 					  GFP_KERNEL);
5468 	if (!err)
5469 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5470 
5471 	if (err) {
5472 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5473 		goto failed_mount6;
5474 	}
5475 
5476 	if (ext4_has_feature_flex_bg(sb))
5477 		if (!ext4_fill_flex_info(sb)) {
5478 			ext4_msg(sb, KERN_ERR,
5479 			       "unable to initialize "
5480 			       "flex_bg meta info!");
5481 			ret = -ENOMEM;
5482 			goto failed_mount6;
5483 		}
5484 
5485 	err = ext4_register_li_request(sb, first_not_zeroed);
5486 	if (err)
5487 		goto failed_mount6;
5488 
5489 	err = ext4_register_sysfs(sb);
5490 	if (err)
5491 		goto failed_mount7;
5492 
5493 	err = ext4_init_orphan_info(sb);
5494 	if (err)
5495 		goto failed_mount8;
5496 #ifdef CONFIG_QUOTA
5497 	/* Enable quota usage during mount. */
5498 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5499 		err = ext4_enable_quotas(sb);
5500 		if (err)
5501 			goto failed_mount9;
5502 	}
5503 #endif  /* CONFIG_QUOTA */
5504 
5505 	/*
5506 	 * Save the original bdev mapping's wb_err value which could be
5507 	 * used to detect the metadata async write error.
5508 	 */
5509 	spin_lock_init(&sbi->s_bdev_wb_lock);
5510 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5511 				 &sbi->s_bdev_wb_err);
5512 	sb->s_bdev->bd_super = sb;
5513 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5514 	ext4_orphan_cleanup(sb, es);
5515 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5516 	/*
5517 	 * Update the checksum after updating free space/inode counters and
5518 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5519 	 * checksum in the buffer cache until it is written out and
5520 	 * e2fsprogs programs trying to open a file system immediately
5521 	 * after it is mounted can fail.
5522 	 */
5523 	ext4_superblock_csum_set(sb);
5524 	if (needs_recovery) {
5525 		ext4_msg(sb, KERN_INFO, "recovery complete");
5526 		err = ext4_mark_recovery_complete(sb, es);
5527 		if (err)
5528 			goto failed_mount9;
5529 	}
5530 
5531 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5532 		ext4_msg(sb, KERN_WARNING,
5533 			 "mounting with \"discard\" option, but the device does not support discard");
5534 
5535 	if (es->s_error_count)
5536 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5537 
5538 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5539 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5540 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5541 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5542 	atomic_set(&sbi->s_warning_count, 0);
5543 	atomic_set(&sbi->s_msg_count, 0);
5544 
5545 	return 0;
5546 
5547 failed_mount9:
5548 	ext4_release_orphan_info(sb);
5549 failed_mount8:
5550 	ext4_unregister_sysfs(sb);
5551 	kobject_put(&sbi->s_kobj);
5552 failed_mount7:
5553 	ext4_unregister_li_request(sb);
5554 failed_mount6:
5555 	ext4_mb_release(sb);
5556 	rcu_read_lock();
5557 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5558 	if (flex_groups) {
5559 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5560 			kvfree(flex_groups[i]);
5561 		kvfree(flex_groups);
5562 	}
5563 	rcu_read_unlock();
5564 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5565 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5566 	percpu_counter_destroy(&sbi->s_dirs_counter);
5567 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5568 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5569 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5570 failed_mount5:
5571 	ext4_ext_release(sb);
5572 	ext4_release_system_zone(sb);
5573 failed_mount4a:
5574 	dput(sb->s_root);
5575 	sb->s_root = NULL;
5576 failed_mount4:
5577 	ext4_msg(sb, KERN_ERR, "mount failed");
5578 	if (EXT4_SB(sb)->rsv_conversion_wq)
5579 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5580 failed_mount_wq:
5581 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5582 	sbi->s_ea_inode_cache = NULL;
5583 
5584 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5585 	sbi->s_ea_block_cache = NULL;
5586 
5587 	if (sbi->s_journal) {
5588 		/* flush s_error_work before journal destroy. */
5589 		flush_work(&sbi->s_error_work);
5590 		jbd2_journal_destroy(sbi->s_journal);
5591 		sbi->s_journal = NULL;
5592 	}
5593 failed_mount3a:
5594 	ext4_es_unregister_shrinker(sbi);
5595 failed_mount3:
5596 	/* flush s_error_work before sbi destroy */
5597 	flush_work(&sbi->s_error_work);
5598 	del_timer_sync(&sbi->s_err_report);
5599 	ext4_stop_mmpd(sbi);
5600 	ext4_group_desc_free(sbi);
5601 failed_mount:
5602 	if (sbi->s_chksum_driver)
5603 		crypto_free_shash(sbi->s_chksum_driver);
5604 
5605 #if IS_ENABLED(CONFIG_UNICODE)
5606 	utf8_unload(sb->s_encoding);
5607 #endif
5608 
5609 #ifdef CONFIG_QUOTA
5610 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5611 		kfree(get_qf_name(sb, sbi, i));
5612 #endif
5613 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5614 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5615 	brelse(sbi->s_sbh);
5616 	ext4_blkdev_remove(sbi);
5617 out_fail:
5618 	sb->s_fs_info = NULL;
5619 	return err ? err : ret;
5620 }
5621 
5622 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5623 {
5624 	struct ext4_fs_context *ctx = fc->fs_private;
5625 	struct ext4_sb_info *sbi;
5626 	const char *descr;
5627 	int ret;
5628 
5629 	sbi = ext4_alloc_sbi(sb);
5630 	if (!sbi)
5631 		return -ENOMEM;
5632 
5633 	fc->s_fs_info = sbi;
5634 
5635 	/* Cleanup superblock name */
5636 	strreplace(sb->s_id, '/', '!');
5637 
5638 	sbi->s_sb_block = 1;	/* Default super block location */
5639 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5640 		sbi->s_sb_block = ctx->s_sb_block;
5641 
5642 	ret = __ext4_fill_super(fc, sb);
5643 	if (ret < 0)
5644 		goto free_sbi;
5645 
5646 	if (sbi->s_journal) {
5647 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5648 			descr = " journalled data mode";
5649 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5650 			descr = " ordered data mode";
5651 		else
5652 			descr = " writeback data mode";
5653 	} else
5654 		descr = "out journal";
5655 
5656 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5657 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5658 			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
5659 
5660 	/* Update the s_overhead_clusters if necessary */
5661 	ext4_update_overhead(sb, false);
5662 	return 0;
5663 
5664 free_sbi:
5665 	ext4_free_sbi(sbi);
5666 	fc->s_fs_info = NULL;
5667 	return ret;
5668 }
5669 
5670 static int ext4_get_tree(struct fs_context *fc)
5671 {
5672 	return get_tree_bdev(fc, ext4_fill_super);
5673 }
5674 
5675 /*
5676  * Setup any per-fs journal parameters now.  We'll do this both on
5677  * initial mount, once the journal has been initialised but before we've
5678  * done any recovery; and again on any subsequent remount.
5679  */
5680 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5681 {
5682 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5683 
5684 	journal->j_commit_interval = sbi->s_commit_interval;
5685 	journal->j_min_batch_time = sbi->s_min_batch_time;
5686 	journal->j_max_batch_time = sbi->s_max_batch_time;
5687 	ext4_fc_init(sb, journal);
5688 
5689 	write_lock(&journal->j_state_lock);
5690 	if (test_opt(sb, BARRIER))
5691 		journal->j_flags |= JBD2_BARRIER;
5692 	else
5693 		journal->j_flags &= ~JBD2_BARRIER;
5694 	if (test_opt(sb, DATA_ERR_ABORT))
5695 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5696 	else
5697 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5698 	write_unlock(&journal->j_state_lock);
5699 }
5700 
5701 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5702 					     unsigned int journal_inum)
5703 {
5704 	struct inode *journal_inode;
5705 
5706 	/*
5707 	 * Test for the existence of a valid inode on disk.  Bad things
5708 	 * happen if we iget() an unused inode, as the subsequent iput()
5709 	 * will try to delete it.
5710 	 */
5711 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5712 	if (IS_ERR(journal_inode)) {
5713 		ext4_msg(sb, KERN_ERR, "no journal found");
5714 		return NULL;
5715 	}
5716 	if (!journal_inode->i_nlink) {
5717 		make_bad_inode(journal_inode);
5718 		iput(journal_inode);
5719 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5720 		return NULL;
5721 	}
5722 
5723 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5724 		  journal_inode, journal_inode->i_size);
5725 	if (!S_ISREG(journal_inode->i_mode)) {
5726 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5727 		iput(journal_inode);
5728 		return NULL;
5729 	}
5730 	return journal_inode;
5731 }
5732 
5733 static journal_t *ext4_get_journal(struct super_block *sb,
5734 				   unsigned int journal_inum)
5735 {
5736 	struct inode *journal_inode;
5737 	journal_t *journal;
5738 
5739 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5740 		return NULL;
5741 
5742 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5743 	if (!journal_inode)
5744 		return NULL;
5745 
5746 	journal = jbd2_journal_init_inode(journal_inode);
5747 	if (!journal) {
5748 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5749 		iput(journal_inode);
5750 		return NULL;
5751 	}
5752 	journal->j_private = sb;
5753 	ext4_init_journal_params(sb, journal);
5754 	return journal;
5755 }
5756 
5757 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5758 				       dev_t j_dev)
5759 {
5760 	struct buffer_head *bh;
5761 	journal_t *journal;
5762 	ext4_fsblk_t start;
5763 	ext4_fsblk_t len;
5764 	int hblock, blocksize;
5765 	ext4_fsblk_t sb_block;
5766 	unsigned long offset;
5767 	struct ext4_super_block *es;
5768 	struct block_device *bdev;
5769 
5770 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5771 		return NULL;
5772 
5773 	bdev = ext4_blkdev_get(j_dev, sb);
5774 	if (bdev == NULL)
5775 		return NULL;
5776 
5777 	blocksize = sb->s_blocksize;
5778 	hblock = bdev_logical_block_size(bdev);
5779 	if (blocksize < hblock) {
5780 		ext4_msg(sb, KERN_ERR,
5781 			"blocksize too small for journal device");
5782 		goto out_bdev;
5783 	}
5784 
5785 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5786 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5787 	set_blocksize(bdev, blocksize);
5788 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5789 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5790 		       "external journal");
5791 		goto out_bdev;
5792 	}
5793 
5794 	es = (struct ext4_super_block *) (bh->b_data + offset);
5795 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5796 	    !(le32_to_cpu(es->s_feature_incompat) &
5797 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5798 		ext4_msg(sb, KERN_ERR, "external journal has "
5799 					"bad superblock");
5800 		brelse(bh);
5801 		goto out_bdev;
5802 	}
5803 
5804 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5805 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5806 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5807 		ext4_msg(sb, KERN_ERR, "external journal has "
5808 				       "corrupt superblock");
5809 		brelse(bh);
5810 		goto out_bdev;
5811 	}
5812 
5813 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5814 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5815 		brelse(bh);
5816 		goto out_bdev;
5817 	}
5818 
5819 	len = ext4_blocks_count(es);
5820 	start = sb_block + 1;
5821 	brelse(bh);	/* we're done with the superblock */
5822 
5823 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5824 					start, len, blocksize);
5825 	if (!journal) {
5826 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5827 		goto out_bdev;
5828 	}
5829 	journal->j_private = sb;
5830 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5831 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5832 		goto out_journal;
5833 	}
5834 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5835 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5836 					"user (unsupported) - %d",
5837 			be32_to_cpu(journal->j_superblock->s_nr_users));
5838 		goto out_journal;
5839 	}
5840 	EXT4_SB(sb)->s_journal_bdev = bdev;
5841 	ext4_init_journal_params(sb, journal);
5842 	return journal;
5843 
5844 out_journal:
5845 	jbd2_journal_destroy(journal);
5846 out_bdev:
5847 	ext4_blkdev_put(bdev);
5848 	return NULL;
5849 }
5850 
5851 static int ext4_load_journal(struct super_block *sb,
5852 			     struct ext4_super_block *es,
5853 			     unsigned long journal_devnum)
5854 {
5855 	journal_t *journal;
5856 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5857 	dev_t journal_dev;
5858 	int err = 0;
5859 	int really_read_only;
5860 	int journal_dev_ro;
5861 
5862 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5863 		return -EFSCORRUPTED;
5864 
5865 	if (journal_devnum &&
5866 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5867 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5868 			"numbers have changed");
5869 		journal_dev = new_decode_dev(journal_devnum);
5870 	} else
5871 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5872 
5873 	if (journal_inum && journal_dev) {
5874 		ext4_msg(sb, KERN_ERR,
5875 			 "filesystem has both journal inode and journal device!");
5876 		return -EINVAL;
5877 	}
5878 
5879 	if (journal_inum) {
5880 		journal = ext4_get_journal(sb, journal_inum);
5881 		if (!journal)
5882 			return -EINVAL;
5883 	} else {
5884 		journal = ext4_get_dev_journal(sb, journal_dev);
5885 		if (!journal)
5886 			return -EINVAL;
5887 	}
5888 
5889 	journal_dev_ro = bdev_read_only(journal->j_dev);
5890 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5891 
5892 	if (journal_dev_ro && !sb_rdonly(sb)) {
5893 		ext4_msg(sb, KERN_ERR,
5894 			 "journal device read-only, try mounting with '-o ro'");
5895 		err = -EROFS;
5896 		goto err_out;
5897 	}
5898 
5899 	/*
5900 	 * Are we loading a blank journal or performing recovery after a
5901 	 * crash?  For recovery, we need to check in advance whether we
5902 	 * can get read-write access to the device.
5903 	 */
5904 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5905 		if (sb_rdonly(sb)) {
5906 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5907 					"required on readonly filesystem");
5908 			if (really_read_only) {
5909 				ext4_msg(sb, KERN_ERR, "write access "
5910 					"unavailable, cannot proceed "
5911 					"(try mounting with noload)");
5912 				err = -EROFS;
5913 				goto err_out;
5914 			}
5915 			ext4_msg(sb, KERN_INFO, "write access will "
5916 			       "be enabled during recovery");
5917 		}
5918 	}
5919 
5920 	if (!(journal->j_flags & JBD2_BARRIER))
5921 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5922 
5923 	if (!ext4_has_feature_journal_needs_recovery(sb))
5924 		err = jbd2_journal_wipe(journal, !really_read_only);
5925 	if (!err) {
5926 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5927 		if (save)
5928 			memcpy(save, ((char *) es) +
5929 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5930 		err = jbd2_journal_load(journal);
5931 		if (save)
5932 			memcpy(((char *) es) + EXT4_S_ERR_START,
5933 			       save, EXT4_S_ERR_LEN);
5934 		kfree(save);
5935 	}
5936 
5937 	if (err) {
5938 		ext4_msg(sb, KERN_ERR, "error loading journal");
5939 		goto err_out;
5940 	}
5941 
5942 	EXT4_SB(sb)->s_journal = journal;
5943 	err = ext4_clear_journal_err(sb, es);
5944 	if (err) {
5945 		EXT4_SB(sb)->s_journal = NULL;
5946 		jbd2_journal_destroy(journal);
5947 		return err;
5948 	}
5949 
5950 	if (!really_read_only && journal_devnum &&
5951 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5952 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5953 
5954 		/* Make sure we flush the recovery flag to disk. */
5955 		ext4_commit_super(sb);
5956 	}
5957 
5958 	return 0;
5959 
5960 err_out:
5961 	jbd2_journal_destroy(journal);
5962 	return err;
5963 }
5964 
5965 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5966 static void ext4_update_super(struct super_block *sb)
5967 {
5968 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5969 	struct ext4_super_block *es = sbi->s_es;
5970 	struct buffer_head *sbh = sbi->s_sbh;
5971 
5972 	lock_buffer(sbh);
5973 	/*
5974 	 * If the file system is mounted read-only, don't update the
5975 	 * superblock write time.  This avoids updating the superblock
5976 	 * write time when we are mounting the root file system
5977 	 * read/only but we need to replay the journal; at that point,
5978 	 * for people who are east of GMT and who make their clock
5979 	 * tick in localtime for Windows bug-for-bug compatibility,
5980 	 * the clock is set in the future, and this will cause e2fsck
5981 	 * to complain and force a full file system check.
5982 	 */
5983 	if (!(sb->s_flags & SB_RDONLY))
5984 		ext4_update_tstamp(es, s_wtime);
5985 	es->s_kbytes_written =
5986 		cpu_to_le64(sbi->s_kbytes_written +
5987 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5988 		      sbi->s_sectors_written_start) >> 1));
5989 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5990 		ext4_free_blocks_count_set(es,
5991 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5992 				&sbi->s_freeclusters_counter)));
5993 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5994 		es->s_free_inodes_count =
5995 			cpu_to_le32(percpu_counter_sum_positive(
5996 				&sbi->s_freeinodes_counter));
5997 	/* Copy error information to the on-disk superblock */
5998 	spin_lock(&sbi->s_error_lock);
5999 	if (sbi->s_add_error_count > 0) {
6000 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6001 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6002 			__ext4_update_tstamp(&es->s_first_error_time,
6003 					     &es->s_first_error_time_hi,
6004 					     sbi->s_first_error_time);
6005 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6006 				sizeof(es->s_first_error_func));
6007 			es->s_first_error_line =
6008 				cpu_to_le32(sbi->s_first_error_line);
6009 			es->s_first_error_ino =
6010 				cpu_to_le32(sbi->s_first_error_ino);
6011 			es->s_first_error_block =
6012 				cpu_to_le64(sbi->s_first_error_block);
6013 			es->s_first_error_errcode =
6014 				ext4_errno_to_code(sbi->s_first_error_code);
6015 		}
6016 		__ext4_update_tstamp(&es->s_last_error_time,
6017 				     &es->s_last_error_time_hi,
6018 				     sbi->s_last_error_time);
6019 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6020 			sizeof(es->s_last_error_func));
6021 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6022 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6023 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6024 		es->s_last_error_errcode =
6025 				ext4_errno_to_code(sbi->s_last_error_code);
6026 		/*
6027 		 * Start the daily error reporting function if it hasn't been
6028 		 * started already
6029 		 */
6030 		if (!es->s_error_count)
6031 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6032 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6033 		sbi->s_add_error_count = 0;
6034 	}
6035 	spin_unlock(&sbi->s_error_lock);
6036 
6037 	ext4_superblock_csum_set(sb);
6038 	unlock_buffer(sbh);
6039 }
6040 
6041 static int ext4_commit_super(struct super_block *sb)
6042 {
6043 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6044 
6045 	if (!sbh)
6046 		return -EINVAL;
6047 	if (block_device_ejected(sb))
6048 		return -ENODEV;
6049 
6050 	ext4_update_super(sb);
6051 
6052 	lock_buffer(sbh);
6053 	/* Buffer got discarded which means block device got invalidated */
6054 	if (!buffer_mapped(sbh)) {
6055 		unlock_buffer(sbh);
6056 		return -EIO;
6057 	}
6058 
6059 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6060 		/*
6061 		 * Oh, dear.  A previous attempt to write the
6062 		 * superblock failed.  This could happen because the
6063 		 * USB device was yanked out.  Or it could happen to
6064 		 * be a transient write error and maybe the block will
6065 		 * be remapped.  Nothing we can do but to retry the
6066 		 * write and hope for the best.
6067 		 */
6068 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6069 		       "superblock detected");
6070 		clear_buffer_write_io_error(sbh);
6071 		set_buffer_uptodate(sbh);
6072 	}
6073 	get_bh(sbh);
6074 	/* Clear potential dirty bit if it was journalled update */
6075 	clear_buffer_dirty(sbh);
6076 	sbh->b_end_io = end_buffer_write_sync;
6077 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6078 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6079 	wait_on_buffer(sbh);
6080 	if (buffer_write_io_error(sbh)) {
6081 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6082 		       "superblock");
6083 		clear_buffer_write_io_error(sbh);
6084 		set_buffer_uptodate(sbh);
6085 		return -EIO;
6086 	}
6087 	return 0;
6088 }
6089 
6090 /*
6091  * Have we just finished recovery?  If so, and if we are mounting (or
6092  * remounting) the filesystem readonly, then we will end up with a
6093  * consistent fs on disk.  Record that fact.
6094  */
6095 static int ext4_mark_recovery_complete(struct super_block *sb,
6096 				       struct ext4_super_block *es)
6097 {
6098 	int err;
6099 	journal_t *journal = EXT4_SB(sb)->s_journal;
6100 
6101 	if (!ext4_has_feature_journal(sb)) {
6102 		if (journal != NULL) {
6103 			ext4_error(sb, "Journal got removed while the fs was "
6104 				   "mounted!");
6105 			return -EFSCORRUPTED;
6106 		}
6107 		return 0;
6108 	}
6109 	jbd2_journal_lock_updates(journal);
6110 	err = jbd2_journal_flush(journal, 0);
6111 	if (err < 0)
6112 		goto out;
6113 
6114 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6115 	    ext4_has_feature_orphan_present(sb))) {
6116 		if (!ext4_orphan_file_empty(sb)) {
6117 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6118 			err = -EFSCORRUPTED;
6119 			goto out;
6120 		}
6121 		ext4_clear_feature_journal_needs_recovery(sb);
6122 		ext4_clear_feature_orphan_present(sb);
6123 		ext4_commit_super(sb);
6124 	}
6125 out:
6126 	jbd2_journal_unlock_updates(journal);
6127 	return err;
6128 }
6129 
6130 /*
6131  * If we are mounting (or read-write remounting) a filesystem whose journal
6132  * has recorded an error from a previous lifetime, move that error to the
6133  * main filesystem now.
6134  */
6135 static int ext4_clear_journal_err(struct super_block *sb,
6136 				   struct ext4_super_block *es)
6137 {
6138 	journal_t *journal;
6139 	int j_errno;
6140 	const char *errstr;
6141 
6142 	if (!ext4_has_feature_journal(sb)) {
6143 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6144 		return -EFSCORRUPTED;
6145 	}
6146 
6147 	journal = EXT4_SB(sb)->s_journal;
6148 
6149 	/*
6150 	 * Now check for any error status which may have been recorded in the
6151 	 * journal by a prior ext4_error() or ext4_abort()
6152 	 */
6153 
6154 	j_errno = jbd2_journal_errno(journal);
6155 	if (j_errno) {
6156 		char nbuf[16];
6157 
6158 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6159 		ext4_warning(sb, "Filesystem error recorded "
6160 			     "from previous mount: %s", errstr);
6161 		ext4_warning(sb, "Marking fs in need of filesystem check.");
6162 
6163 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6164 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6165 		ext4_commit_super(sb);
6166 
6167 		jbd2_journal_clear_err(journal);
6168 		jbd2_journal_update_sb_errno(journal);
6169 	}
6170 	return 0;
6171 }
6172 
6173 /*
6174  * Force the running and committing transactions to commit,
6175  * and wait on the commit.
6176  */
6177 int ext4_force_commit(struct super_block *sb)
6178 {
6179 	journal_t *journal;
6180 
6181 	if (sb_rdonly(sb))
6182 		return 0;
6183 
6184 	journal = EXT4_SB(sb)->s_journal;
6185 	return ext4_journal_force_commit(journal);
6186 }
6187 
6188 static int ext4_sync_fs(struct super_block *sb, int wait)
6189 {
6190 	int ret = 0;
6191 	tid_t target;
6192 	bool needs_barrier = false;
6193 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6194 
6195 	if (unlikely(ext4_forced_shutdown(sbi)))
6196 		return 0;
6197 
6198 	trace_ext4_sync_fs(sb, wait);
6199 	flush_workqueue(sbi->rsv_conversion_wq);
6200 	/*
6201 	 * Writeback quota in non-journalled quota case - journalled quota has
6202 	 * no dirty dquots
6203 	 */
6204 	dquot_writeback_dquots(sb, -1);
6205 	/*
6206 	 * Data writeback is possible w/o journal transaction, so barrier must
6207 	 * being sent at the end of the function. But we can skip it if
6208 	 * transaction_commit will do it for us.
6209 	 */
6210 	if (sbi->s_journal) {
6211 		target = jbd2_get_latest_transaction(sbi->s_journal);
6212 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6213 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6214 			needs_barrier = true;
6215 
6216 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6217 			if (wait)
6218 				ret = jbd2_log_wait_commit(sbi->s_journal,
6219 							   target);
6220 		}
6221 	} else if (wait && test_opt(sb, BARRIER))
6222 		needs_barrier = true;
6223 	if (needs_barrier) {
6224 		int err;
6225 		err = blkdev_issue_flush(sb->s_bdev);
6226 		if (!ret)
6227 			ret = err;
6228 	}
6229 
6230 	return ret;
6231 }
6232 
6233 /*
6234  * LVM calls this function before a (read-only) snapshot is created.  This
6235  * gives us a chance to flush the journal completely and mark the fs clean.
6236  *
6237  * Note that only this function cannot bring a filesystem to be in a clean
6238  * state independently. It relies on upper layer to stop all data & metadata
6239  * modifications.
6240  */
6241 static int ext4_freeze(struct super_block *sb)
6242 {
6243 	int error = 0;
6244 	journal_t *journal;
6245 
6246 	if (sb_rdonly(sb))
6247 		return 0;
6248 
6249 	journal = EXT4_SB(sb)->s_journal;
6250 
6251 	if (journal) {
6252 		/* Now we set up the journal barrier. */
6253 		jbd2_journal_lock_updates(journal);
6254 
6255 		/*
6256 		 * Don't clear the needs_recovery flag if we failed to
6257 		 * flush the journal.
6258 		 */
6259 		error = jbd2_journal_flush(journal, 0);
6260 		if (error < 0)
6261 			goto out;
6262 
6263 		/* Journal blocked and flushed, clear needs_recovery flag. */
6264 		ext4_clear_feature_journal_needs_recovery(sb);
6265 		if (ext4_orphan_file_empty(sb))
6266 			ext4_clear_feature_orphan_present(sb);
6267 	}
6268 
6269 	error = ext4_commit_super(sb);
6270 out:
6271 	if (journal)
6272 		/* we rely on upper layer to stop further updates */
6273 		jbd2_journal_unlock_updates(journal);
6274 	return error;
6275 }
6276 
6277 /*
6278  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6279  * flag here, even though the filesystem is not technically dirty yet.
6280  */
6281 static int ext4_unfreeze(struct super_block *sb)
6282 {
6283 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6284 		return 0;
6285 
6286 	if (EXT4_SB(sb)->s_journal) {
6287 		/* Reset the needs_recovery flag before the fs is unlocked. */
6288 		ext4_set_feature_journal_needs_recovery(sb);
6289 		if (ext4_has_feature_orphan_file(sb))
6290 			ext4_set_feature_orphan_present(sb);
6291 	}
6292 
6293 	ext4_commit_super(sb);
6294 	return 0;
6295 }
6296 
6297 /*
6298  * Structure to save mount options for ext4_remount's benefit
6299  */
6300 struct ext4_mount_options {
6301 	unsigned long s_mount_opt;
6302 	unsigned long s_mount_opt2;
6303 	kuid_t s_resuid;
6304 	kgid_t s_resgid;
6305 	unsigned long s_commit_interval;
6306 	u32 s_min_batch_time, s_max_batch_time;
6307 #ifdef CONFIG_QUOTA
6308 	int s_jquota_fmt;
6309 	char *s_qf_names[EXT4_MAXQUOTAS];
6310 #endif
6311 };
6312 
6313 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6314 {
6315 	struct ext4_fs_context *ctx = fc->fs_private;
6316 	struct ext4_super_block *es;
6317 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6318 	unsigned long old_sb_flags;
6319 	struct ext4_mount_options old_opts;
6320 	ext4_group_t g;
6321 	int err = 0;
6322 #ifdef CONFIG_QUOTA
6323 	int enable_quota = 0;
6324 	int i, j;
6325 	char *to_free[EXT4_MAXQUOTAS];
6326 #endif
6327 
6328 
6329 	/* Store the original options */
6330 	old_sb_flags = sb->s_flags;
6331 	old_opts.s_mount_opt = sbi->s_mount_opt;
6332 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6333 	old_opts.s_resuid = sbi->s_resuid;
6334 	old_opts.s_resgid = sbi->s_resgid;
6335 	old_opts.s_commit_interval = sbi->s_commit_interval;
6336 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6337 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6338 #ifdef CONFIG_QUOTA
6339 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6340 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6341 		if (sbi->s_qf_names[i]) {
6342 			char *qf_name = get_qf_name(sb, sbi, i);
6343 
6344 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6345 			if (!old_opts.s_qf_names[i]) {
6346 				for (j = 0; j < i; j++)
6347 					kfree(old_opts.s_qf_names[j]);
6348 				return -ENOMEM;
6349 			}
6350 		} else
6351 			old_opts.s_qf_names[i] = NULL;
6352 #endif
6353 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6354 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6355 			ctx->journal_ioprio =
6356 				sbi->s_journal->j_task->io_context->ioprio;
6357 		else
6358 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6359 
6360 	}
6361 
6362 	ext4_apply_options(fc, sb);
6363 
6364 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6365 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6366 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6367 			 "during remount not supported; ignoring");
6368 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6369 	}
6370 
6371 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6372 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6373 			ext4_msg(sb, KERN_ERR, "can't mount with "
6374 				 "both data=journal and delalloc");
6375 			err = -EINVAL;
6376 			goto restore_opts;
6377 		}
6378 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6379 			ext4_msg(sb, KERN_ERR, "can't mount with "
6380 				 "both data=journal and dioread_nolock");
6381 			err = -EINVAL;
6382 			goto restore_opts;
6383 		}
6384 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6385 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6386 			ext4_msg(sb, KERN_ERR, "can't mount with "
6387 				"journal_async_commit in data=ordered mode");
6388 			err = -EINVAL;
6389 			goto restore_opts;
6390 		}
6391 	}
6392 
6393 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6394 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6395 		err = -EINVAL;
6396 		goto restore_opts;
6397 	}
6398 
6399 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6400 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6401 
6402 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6403 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6404 
6405 	es = sbi->s_es;
6406 
6407 	if (sbi->s_journal) {
6408 		ext4_init_journal_params(sb, sbi->s_journal);
6409 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6410 	}
6411 
6412 	/* Flush outstanding errors before changing fs state */
6413 	flush_work(&sbi->s_error_work);
6414 
6415 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6416 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6417 			err = -EROFS;
6418 			goto restore_opts;
6419 		}
6420 
6421 		if (fc->sb_flags & SB_RDONLY) {
6422 			err = sync_filesystem(sb);
6423 			if (err < 0)
6424 				goto restore_opts;
6425 			err = dquot_suspend(sb, -1);
6426 			if (err < 0)
6427 				goto restore_opts;
6428 
6429 			/*
6430 			 * First of all, the unconditional stuff we have to do
6431 			 * to disable replay of the journal when we next remount
6432 			 */
6433 			sb->s_flags |= SB_RDONLY;
6434 
6435 			/*
6436 			 * OK, test if we are remounting a valid rw partition
6437 			 * readonly, and if so set the rdonly flag and then
6438 			 * mark the partition as valid again.
6439 			 */
6440 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6441 			    (sbi->s_mount_state & EXT4_VALID_FS))
6442 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6443 
6444 			if (sbi->s_journal) {
6445 				/*
6446 				 * We let remount-ro finish even if marking fs
6447 				 * as clean failed...
6448 				 */
6449 				ext4_mark_recovery_complete(sb, es);
6450 			}
6451 		} else {
6452 			/* Make sure we can mount this feature set readwrite */
6453 			if (ext4_has_feature_readonly(sb) ||
6454 			    !ext4_feature_set_ok(sb, 0)) {
6455 				err = -EROFS;
6456 				goto restore_opts;
6457 			}
6458 			/*
6459 			 * Make sure the group descriptor checksums
6460 			 * are sane.  If they aren't, refuse to remount r/w.
6461 			 */
6462 			for (g = 0; g < sbi->s_groups_count; g++) {
6463 				struct ext4_group_desc *gdp =
6464 					ext4_get_group_desc(sb, g, NULL);
6465 
6466 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6467 					ext4_msg(sb, KERN_ERR,
6468 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6469 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6470 					       le16_to_cpu(gdp->bg_checksum));
6471 					err = -EFSBADCRC;
6472 					goto restore_opts;
6473 				}
6474 			}
6475 
6476 			/*
6477 			 * If we have an unprocessed orphan list hanging
6478 			 * around from a previously readonly bdev mount,
6479 			 * require a full umount/remount for now.
6480 			 */
6481 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6482 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6483 				       "remount RDWR because of unprocessed "
6484 				       "orphan inode list.  Please "
6485 				       "umount/remount instead");
6486 				err = -EINVAL;
6487 				goto restore_opts;
6488 			}
6489 
6490 			/*
6491 			 * Mounting a RDONLY partition read-write, so reread
6492 			 * and store the current valid flag.  (It may have
6493 			 * been changed by e2fsck since we originally mounted
6494 			 * the partition.)
6495 			 */
6496 			if (sbi->s_journal) {
6497 				err = ext4_clear_journal_err(sb, es);
6498 				if (err)
6499 					goto restore_opts;
6500 			}
6501 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6502 					      ~EXT4_FC_REPLAY);
6503 
6504 			err = ext4_setup_super(sb, es, 0);
6505 			if (err)
6506 				goto restore_opts;
6507 
6508 			sb->s_flags &= ~SB_RDONLY;
6509 			if (ext4_has_feature_mmp(sb))
6510 				if (ext4_multi_mount_protect(sb,
6511 						le64_to_cpu(es->s_mmp_block))) {
6512 					err = -EROFS;
6513 					goto restore_opts;
6514 				}
6515 #ifdef CONFIG_QUOTA
6516 			enable_quota = 1;
6517 #endif
6518 		}
6519 	}
6520 
6521 	/*
6522 	 * Reinitialize lazy itable initialization thread based on
6523 	 * current settings
6524 	 */
6525 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6526 		ext4_unregister_li_request(sb);
6527 	else {
6528 		ext4_group_t first_not_zeroed;
6529 		first_not_zeroed = ext4_has_uninit_itable(sb);
6530 		ext4_register_li_request(sb, first_not_zeroed);
6531 	}
6532 
6533 	/*
6534 	 * Handle creation of system zone data early because it can fail.
6535 	 * Releasing of existing data is done when we are sure remount will
6536 	 * succeed.
6537 	 */
6538 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6539 		err = ext4_setup_system_zone(sb);
6540 		if (err)
6541 			goto restore_opts;
6542 	}
6543 
6544 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6545 		err = ext4_commit_super(sb);
6546 		if (err)
6547 			goto restore_opts;
6548 	}
6549 
6550 #ifdef CONFIG_QUOTA
6551 	/* Release old quota file names */
6552 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6553 		kfree(old_opts.s_qf_names[i]);
6554 	if (enable_quota) {
6555 		if (sb_any_quota_suspended(sb))
6556 			dquot_resume(sb, -1);
6557 		else if (ext4_has_feature_quota(sb)) {
6558 			err = ext4_enable_quotas(sb);
6559 			if (err)
6560 				goto restore_opts;
6561 		}
6562 	}
6563 #endif
6564 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6565 		ext4_release_system_zone(sb);
6566 
6567 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6568 		ext4_stop_mmpd(sbi);
6569 
6570 	return 0;
6571 
6572 restore_opts:
6573 	sb->s_flags = old_sb_flags;
6574 	sbi->s_mount_opt = old_opts.s_mount_opt;
6575 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6576 	sbi->s_resuid = old_opts.s_resuid;
6577 	sbi->s_resgid = old_opts.s_resgid;
6578 	sbi->s_commit_interval = old_opts.s_commit_interval;
6579 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6580 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6581 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6582 		ext4_release_system_zone(sb);
6583 #ifdef CONFIG_QUOTA
6584 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6585 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6586 		to_free[i] = get_qf_name(sb, sbi, i);
6587 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6588 	}
6589 	synchronize_rcu();
6590 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6591 		kfree(to_free[i]);
6592 #endif
6593 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6594 		ext4_stop_mmpd(sbi);
6595 	return err;
6596 }
6597 
6598 static int ext4_reconfigure(struct fs_context *fc)
6599 {
6600 	struct super_block *sb = fc->root->d_sb;
6601 	int ret;
6602 
6603 	fc->s_fs_info = EXT4_SB(sb);
6604 
6605 	ret = ext4_check_opt_consistency(fc, sb);
6606 	if (ret < 0)
6607 		return ret;
6608 
6609 	ret = __ext4_remount(fc, sb);
6610 	if (ret < 0)
6611 		return ret;
6612 
6613 	ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6614 		 ext4_quota_mode(sb));
6615 
6616 	return 0;
6617 }
6618 
6619 #ifdef CONFIG_QUOTA
6620 static int ext4_statfs_project(struct super_block *sb,
6621 			       kprojid_t projid, struct kstatfs *buf)
6622 {
6623 	struct kqid qid;
6624 	struct dquot *dquot;
6625 	u64 limit;
6626 	u64 curblock;
6627 
6628 	qid = make_kqid_projid(projid);
6629 	dquot = dqget(sb, qid);
6630 	if (IS_ERR(dquot))
6631 		return PTR_ERR(dquot);
6632 	spin_lock(&dquot->dq_dqb_lock);
6633 
6634 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6635 			     dquot->dq_dqb.dqb_bhardlimit);
6636 	limit >>= sb->s_blocksize_bits;
6637 
6638 	if (limit && buf->f_blocks > limit) {
6639 		curblock = (dquot->dq_dqb.dqb_curspace +
6640 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6641 		buf->f_blocks = limit;
6642 		buf->f_bfree = buf->f_bavail =
6643 			(buf->f_blocks > curblock) ?
6644 			 (buf->f_blocks - curblock) : 0;
6645 	}
6646 
6647 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6648 			     dquot->dq_dqb.dqb_ihardlimit);
6649 	if (limit && buf->f_files > limit) {
6650 		buf->f_files = limit;
6651 		buf->f_ffree =
6652 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6653 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6654 	}
6655 
6656 	spin_unlock(&dquot->dq_dqb_lock);
6657 	dqput(dquot);
6658 	return 0;
6659 }
6660 #endif
6661 
6662 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6663 {
6664 	struct super_block *sb = dentry->d_sb;
6665 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6666 	struct ext4_super_block *es = sbi->s_es;
6667 	ext4_fsblk_t overhead = 0, resv_blocks;
6668 	s64 bfree;
6669 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6670 
6671 	if (!test_opt(sb, MINIX_DF))
6672 		overhead = sbi->s_overhead;
6673 
6674 	buf->f_type = EXT4_SUPER_MAGIC;
6675 	buf->f_bsize = sb->s_blocksize;
6676 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6677 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6678 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6679 	/* prevent underflow in case that few free space is available */
6680 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6681 	buf->f_bavail = buf->f_bfree -
6682 			(ext4_r_blocks_count(es) + resv_blocks);
6683 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6684 		buf->f_bavail = 0;
6685 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6686 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6687 	buf->f_namelen = EXT4_NAME_LEN;
6688 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6689 
6690 #ifdef CONFIG_QUOTA
6691 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6692 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6693 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6694 #endif
6695 	return 0;
6696 }
6697 
6698 
6699 #ifdef CONFIG_QUOTA
6700 
6701 /*
6702  * Helper functions so that transaction is started before we acquire dqio_sem
6703  * to keep correct lock ordering of transaction > dqio_sem
6704  */
6705 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6706 {
6707 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6708 }
6709 
6710 static int ext4_write_dquot(struct dquot *dquot)
6711 {
6712 	int ret, err;
6713 	handle_t *handle;
6714 	struct inode *inode;
6715 
6716 	inode = dquot_to_inode(dquot);
6717 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6718 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6719 	if (IS_ERR(handle))
6720 		return PTR_ERR(handle);
6721 	ret = dquot_commit(dquot);
6722 	err = ext4_journal_stop(handle);
6723 	if (!ret)
6724 		ret = err;
6725 	return ret;
6726 }
6727 
6728 static int ext4_acquire_dquot(struct dquot *dquot)
6729 {
6730 	int ret, err;
6731 	handle_t *handle;
6732 
6733 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6734 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6735 	if (IS_ERR(handle))
6736 		return PTR_ERR(handle);
6737 	ret = dquot_acquire(dquot);
6738 	err = ext4_journal_stop(handle);
6739 	if (!ret)
6740 		ret = err;
6741 	return ret;
6742 }
6743 
6744 static int ext4_release_dquot(struct dquot *dquot)
6745 {
6746 	int ret, err;
6747 	handle_t *handle;
6748 
6749 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6750 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6751 	if (IS_ERR(handle)) {
6752 		/* Release dquot anyway to avoid endless cycle in dqput() */
6753 		dquot_release(dquot);
6754 		return PTR_ERR(handle);
6755 	}
6756 	ret = dquot_release(dquot);
6757 	err = ext4_journal_stop(handle);
6758 	if (!ret)
6759 		ret = err;
6760 	return ret;
6761 }
6762 
6763 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6764 {
6765 	struct super_block *sb = dquot->dq_sb;
6766 
6767 	if (ext4_is_quota_journalled(sb)) {
6768 		dquot_mark_dquot_dirty(dquot);
6769 		return ext4_write_dquot(dquot);
6770 	} else {
6771 		return dquot_mark_dquot_dirty(dquot);
6772 	}
6773 }
6774 
6775 static int ext4_write_info(struct super_block *sb, int type)
6776 {
6777 	int ret, err;
6778 	handle_t *handle;
6779 
6780 	/* Data block + inode block */
6781 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6782 	if (IS_ERR(handle))
6783 		return PTR_ERR(handle);
6784 	ret = dquot_commit_info(sb, type);
6785 	err = ext4_journal_stop(handle);
6786 	if (!ret)
6787 		ret = err;
6788 	return ret;
6789 }
6790 
6791 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6792 {
6793 	struct ext4_inode_info *ei = EXT4_I(inode);
6794 
6795 	/* The first argument of lockdep_set_subclass has to be
6796 	 * *exactly* the same as the argument to init_rwsem() --- in
6797 	 * this case, in init_once() --- or lockdep gets unhappy
6798 	 * because the name of the lock is set using the
6799 	 * stringification of the argument to init_rwsem().
6800 	 */
6801 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6802 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6803 }
6804 
6805 /*
6806  * Standard function to be called on quota_on
6807  */
6808 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6809 			 const struct path *path)
6810 {
6811 	int err;
6812 
6813 	if (!test_opt(sb, QUOTA))
6814 		return -EINVAL;
6815 
6816 	/* Quotafile not on the same filesystem? */
6817 	if (path->dentry->d_sb != sb)
6818 		return -EXDEV;
6819 
6820 	/* Quota already enabled for this file? */
6821 	if (IS_NOQUOTA(d_inode(path->dentry)))
6822 		return -EBUSY;
6823 
6824 	/* Journaling quota? */
6825 	if (EXT4_SB(sb)->s_qf_names[type]) {
6826 		/* Quotafile not in fs root? */
6827 		if (path->dentry->d_parent != sb->s_root)
6828 			ext4_msg(sb, KERN_WARNING,
6829 				"Quota file not on filesystem root. "
6830 				"Journaled quota will not work");
6831 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6832 	} else {
6833 		/*
6834 		 * Clear the flag just in case mount options changed since
6835 		 * last time.
6836 		 */
6837 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6838 	}
6839 
6840 	/*
6841 	 * When we journal data on quota file, we have to flush journal to see
6842 	 * all updates to the file when we bypass pagecache...
6843 	 */
6844 	if (EXT4_SB(sb)->s_journal &&
6845 	    ext4_should_journal_data(d_inode(path->dentry))) {
6846 		/*
6847 		 * We don't need to lock updates but journal_flush() could
6848 		 * otherwise be livelocked...
6849 		 */
6850 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6851 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6852 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6853 		if (err)
6854 			return err;
6855 	}
6856 
6857 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6858 	err = dquot_quota_on(sb, type, format_id, path);
6859 	if (!err) {
6860 		struct inode *inode = d_inode(path->dentry);
6861 		handle_t *handle;
6862 
6863 		/*
6864 		 * Set inode flags to prevent userspace from messing with quota
6865 		 * files. If this fails, we return success anyway since quotas
6866 		 * are already enabled and this is not a hard failure.
6867 		 */
6868 		inode_lock(inode);
6869 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6870 		if (IS_ERR(handle))
6871 			goto unlock_inode;
6872 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6873 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6874 				S_NOATIME | S_IMMUTABLE);
6875 		err = ext4_mark_inode_dirty(handle, inode);
6876 		ext4_journal_stop(handle);
6877 	unlock_inode:
6878 		inode_unlock(inode);
6879 		if (err)
6880 			dquot_quota_off(sb, type);
6881 	}
6882 	if (err)
6883 		lockdep_set_quota_inode(path->dentry->d_inode,
6884 					     I_DATA_SEM_NORMAL);
6885 	return err;
6886 }
6887 
6888 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6889 			     unsigned int flags)
6890 {
6891 	int err;
6892 	struct inode *qf_inode;
6893 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6894 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6895 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6896 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6897 	};
6898 
6899 	BUG_ON(!ext4_has_feature_quota(sb));
6900 
6901 	if (!qf_inums[type])
6902 		return -EPERM;
6903 
6904 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6905 	if (IS_ERR(qf_inode)) {
6906 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6907 		return PTR_ERR(qf_inode);
6908 	}
6909 
6910 	/* Don't account quota for quota files to avoid recursion */
6911 	qf_inode->i_flags |= S_NOQUOTA;
6912 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6913 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6914 	if (err)
6915 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6916 	iput(qf_inode);
6917 
6918 	return err;
6919 }
6920 
6921 /* Enable usage tracking for all quota types. */
6922 int ext4_enable_quotas(struct super_block *sb)
6923 {
6924 	int type, err = 0;
6925 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6926 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6927 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6928 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6929 	};
6930 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6931 		test_opt(sb, USRQUOTA),
6932 		test_opt(sb, GRPQUOTA),
6933 		test_opt(sb, PRJQUOTA),
6934 	};
6935 
6936 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6937 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6938 		if (qf_inums[type]) {
6939 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6940 				DQUOT_USAGE_ENABLED |
6941 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6942 			if (err) {
6943 				ext4_warning(sb,
6944 					"Failed to enable quota tracking "
6945 					"(type=%d, err=%d). Please run "
6946 					"e2fsck to fix.", type, err);
6947 				for (type--; type >= 0; type--) {
6948 					struct inode *inode;
6949 
6950 					inode = sb_dqopt(sb)->files[type];
6951 					if (inode)
6952 						inode = igrab(inode);
6953 					dquot_quota_off(sb, type);
6954 					if (inode) {
6955 						lockdep_set_quota_inode(inode,
6956 							I_DATA_SEM_NORMAL);
6957 						iput(inode);
6958 					}
6959 				}
6960 
6961 				return err;
6962 			}
6963 		}
6964 	}
6965 	return 0;
6966 }
6967 
6968 static int ext4_quota_off(struct super_block *sb, int type)
6969 {
6970 	struct inode *inode = sb_dqopt(sb)->files[type];
6971 	handle_t *handle;
6972 	int err;
6973 
6974 	/* Force all delayed allocation blocks to be allocated.
6975 	 * Caller already holds s_umount sem */
6976 	if (test_opt(sb, DELALLOC))
6977 		sync_filesystem(sb);
6978 
6979 	if (!inode || !igrab(inode))
6980 		goto out;
6981 
6982 	err = dquot_quota_off(sb, type);
6983 	if (err || ext4_has_feature_quota(sb))
6984 		goto out_put;
6985 
6986 	inode_lock(inode);
6987 	/*
6988 	 * Update modification times of quota files when userspace can
6989 	 * start looking at them. If we fail, we return success anyway since
6990 	 * this is not a hard failure and quotas are already disabled.
6991 	 */
6992 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6993 	if (IS_ERR(handle)) {
6994 		err = PTR_ERR(handle);
6995 		goto out_unlock;
6996 	}
6997 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6998 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6999 	inode->i_mtime = inode->i_ctime = current_time(inode);
7000 	err = ext4_mark_inode_dirty(handle, inode);
7001 	ext4_journal_stop(handle);
7002 out_unlock:
7003 	inode_unlock(inode);
7004 out_put:
7005 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7006 	iput(inode);
7007 	return err;
7008 out:
7009 	return dquot_quota_off(sb, type);
7010 }
7011 
7012 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7013  * acquiring the locks... As quota files are never truncated and quota code
7014  * itself serializes the operations (and no one else should touch the files)
7015  * we don't have to be afraid of races */
7016 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7017 			       size_t len, loff_t off)
7018 {
7019 	struct inode *inode = sb_dqopt(sb)->files[type];
7020 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7021 	int offset = off & (sb->s_blocksize - 1);
7022 	int tocopy;
7023 	size_t toread;
7024 	struct buffer_head *bh;
7025 	loff_t i_size = i_size_read(inode);
7026 
7027 	if (off > i_size)
7028 		return 0;
7029 	if (off+len > i_size)
7030 		len = i_size-off;
7031 	toread = len;
7032 	while (toread > 0) {
7033 		tocopy = sb->s_blocksize - offset < toread ?
7034 				sb->s_blocksize - offset : toread;
7035 		bh = ext4_bread(NULL, inode, blk, 0);
7036 		if (IS_ERR(bh))
7037 			return PTR_ERR(bh);
7038 		if (!bh)	/* A hole? */
7039 			memset(data, 0, tocopy);
7040 		else
7041 			memcpy(data, bh->b_data+offset, tocopy);
7042 		brelse(bh);
7043 		offset = 0;
7044 		toread -= tocopy;
7045 		data += tocopy;
7046 		blk++;
7047 	}
7048 	return len;
7049 }
7050 
7051 /* Write to quotafile (we know the transaction is already started and has
7052  * enough credits) */
7053 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7054 				const char *data, size_t len, loff_t off)
7055 {
7056 	struct inode *inode = sb_dqopt(sb)->files[type];
7057 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7058 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7059 	int retries = 0;
7060 	struct buffer_head *bh;
7061 	handle_t *handle = journal_current_handle();
7062 
7063 	if (!handle) {
7064 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7065 			" cancelled because transaction is not started",
7066 			(unsigned long long)off, (unsigned long long)len);
7067 		return -EIO;
7068 	}
7069 	/*
7070 	 * Since we account only one data block in transaction credits,
7071 	 * then it is impossible to cross a block boundary.
7072 	 */
7073 	if (sb->s_blocksize - offset < len) {
7074 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7075 			" cancelled because not block aligned",
7076 			(unsigned long long)off, (unsigned long long)len);
7077 		return -EIO;
7078 	}
7079 
7080 	do {
7081 		bh = ext4_bread(handle, inode, blk,
7082 				EXT4_GET_BLOCKS_CREATE |
7083 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7084 	} while (PTR_ERR(bh) == -ENOSPC &&
7085 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7086 	if (IS_ERR(bh))
7087 		return PTR_ERR(bh);
7088 	if (!bh)
7089 		goto out;
7090 	BUFFER_TRACE(bh, "get write access");
7091 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7092 	if (err) {
7093 		brelse(bh);
7094 		return err;
7095 	}
7096 	lock_buffer(bh);
7097 	memcpy(bh->b_data+offset, data, len);
7098 	flush_dcache_page(bh->b_page);
7099 	unlock_buffer(bh);
7100 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7101 	brelse(bh);
7102 out:
7103 	if (inode->i_size < off + len) {
7104 		i_size_write(inode, off + len);
7105 		EXT4_I(inode)->i_disksize = inode->i_size;
7106 		err2 = ext4_mark_inode_dirty(handle, inode);
7107 		if (unlikely(err2 && !err))
7108 			err = err2;
7109 	}
7110 	return err ? err : len;
7111 }
7112 #endif
7113 
7114 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7115 static inline void register_as_ext2(void)
7116 {
7117 	int err = register_filesystem(&ext2_fs_type);
7118 	if (err)
7119 		printk(KERN_WARNING
7120 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7121 }
7122 
7123 static inline void unregister_as_ext2(void)
7124 {
7125 	unregister_filesystem(&ext2_fs_type);
7126 }
7127 
7128 static inline int ext2_feature_set_ok(struct super_block *sb)
7129 {
7130 	if (ext4_has_unknown_ext2_incompat_features(sb))
7131 		return 0;
7132 	if (sb_rdonly(sb))
7133 		return 1;
7134 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7135 		return 0;
7136 	return 1;
7137 }
7138 #else
7139 static inline void register_as_ext2(void) { }
7140 static inline void unregister_as_ext2(void) { }
7141 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7142 #endif
7143 
7144 static inline void register_as_ext3(void)
7145 {
7146 	int err = register_filesystem(&ext3_fs_type);
7147 	if (err)
7148 		printk(KERN_WARNING
7149 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7150 }
7151 
7152 static inline void unregister_as_ext3(void)
7153 {
7154 	unregister_filesystem(&ext3_fs_type);
7155 }
7156 
7157 static inline int ext3_feature_set_ok(struct super_block *sb)
7158 {
7159 	if (ext4_has_unknown_ext3_incompat_features(sb))
7160 		return 0;
7161 	if (!ext4_has_feature_journal(sb))
7162 		return 0;
7163 	if (sb_rdonly(sb))
7164 		return 1;
7165 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7166 		return 0;
7167 	return 1;
7168 }
7169 
7170 static struct file_system_type ext4_fs_type = {
7171 	.owner			= THIS_MODULE,
7172 	.name			= "ext4",
7173 	.init_fs_context	= ext4_init_fs_context,
7174 	.parameters		= ext4_param_specs,
7175 	.kill_sb		= kill_block_super,
7176 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7177 };
7178 MODULE_ALIAS_FS("ext4");
7179 
7180 /* Shared across all ext4 file systems */
7181 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7182 
7183 static int __init ext4_init_fs(void)
7184 {
7185 	int i, err;
7186 
7187 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7188 	ext4_li_info = NULL;
7189 
7190 	/* Build-time check for flags consistency */
7191 	ext4_check_flag_values();
7192 
7193 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7194 		init_waitqueue_head(&ext4__ioend_wq[i]);
7195 
7196 	err = ext4_init_es();
7197 	if (err)
7198 		return err;
7199 
7200 	err = ext4_init_pending();
7201 	if (err)
7202 		goto out7;
7203 
7204 	err = ext4_init_post_read_processing();
7205 	if (err)
7206 		goto out6;
7207 
7208 	err = ext4_init_pageio();
7209 	if (err)
7210 		goto out5;
7211 
7212 	err = ext4_init_system_zone();
7213 	if (err)
7214 		goto out4;
7215 
7216 	err = ext4_init_sysfs();
7217 	if (err)
7218 		goto out3;
7219 
7220 	err = ext4_init_mballoc();
7221 	if (err)
7222 		goto out2;
7223 	err = init_inodecache();
7224 	if (err)
7225 		goto out1;
7226 
7227 	err = ext4_fc_init_dentry_cache();
7228 	if (err)
7229 		goto out05;
7230 
7231 	register_as_ext3();
7232 	register_as_ext2();
7233 	err = register_filesystem(&ext4_fs_type);
7234 	if (err)
7235 		goto out;
7236 
7237 	return 0;
7238 out:
7239 	unregister_as_ext2();
7240 	unregister_as_ext3();
7241 	ext4_fc_destroy_dentry_cache();
7242 out05:
7243 	destroy_inodecache();
7244 out1:
7245 	ext4_exit_mballoc();
7246 out2:
7247 	ext4_exit_sysfs();
7248 out3:
7249 	ext4_exit_system_zone();
7250 out4:
7251 	ext4_exit_pageio();
7252 out5:
7253 	ext4_exit_post_read_processing();
7254 out6:
7255 	ext4_exit_pending();
7256 out7:
7257 	ext4_exit_es();
7258 
7259 	return err;
7260 }
7261 
7262 static void __exit ext4_exit_fs(void)
7263 {
7264 	ext4_destroy_lazyinit_thread();
7265 	unregister_as_ext2();
7266 	unregister_as_ext3();
7267 	unregister_filesystem(&ext4_fs_type);
7268 	ext4_fc_destroy_dentry_cache();
7269 	destroy_inodecache();
7270 	ext4_exit_mballoc();
7271 	ext4_exit_sysfs();
7272 	ext4_exit_system_zone();
7273 	ext4_exit_pageio();
7274 	ext4_exit_post_read_processing();
7275 	ext4_exit_es();
7276 	ext4_exit_pending();
7277 }
7278 
7279 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7280 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7281 MODULE_LICENSE("GPL");
7282 MODULE_SOFTDEP("pre: crc32c");
7283 module_init(ext4_init_fs)
7284 module_exit(ext4_exit_fs)
7285