xref: /openbmc/linux/fs/ext4/super.c (revision d9e9d230)
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, int op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ, op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
207 {
208 	if (trylock_buffer(bh)) {
209 		if (wait)
210 			return ext4_read_bh(bh, op_flags, NULL);
211 		ext4_read_bh_nowait(bh, op_flags, NULL);
212 		return 0;
213 	}
214 	if (wait) {
215 		wait_on_buffer(bh);
216 		if (buffer_uptodate(bh))
217 			return 0;
218 		return -EIO;
219 	}
220 	return 0;
221 }
222 
223 /*
224  * This works like __bread_gfp() except it uses ERR_PTR for error
225  * returns.  Currently with sb_bread it's impossible to distinguish
226  * between ENOMEM and EIO situations (since both result in a NULL
227  * return.
228  */
229 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
230 					       sector_t block, int op_flags,
231 					       gfp_t gfp)
232 {
233 	struct buffer_head *bh;
234 	int ret;
235 
236 	bh = sb_getblk_gfp(sb, block, gfp);
237 	if (bh == NULL)
238 		return ERR_PTR(-ENOMEM);
239 	if (ext4_buffer_uptodate(bh))
240 		return bh;
241 
242 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
243 	if (ret) {
244 		put_bh(bh);
245 		return ERR_PTR(ret);
246 	}
247 	return bh;
248 }
249 
250 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
251 				   int op_flags)
252 {
253 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
254 }
255 
256 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
257 					    sector_t block)
258 {
259 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
260 }
261 
262 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
263 {
264 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
265 
266 	if (likely(bh)) {
267 		ext4_read_bh_lock(bh, REQ_RAHEAD, false);
268 		brelse(bh);
269 	}
270 }
271 
272 static int ext4_verify_csum_type(struct super_block *sb,
273 				 struct ext4_super_block *es)
274 {
275 	if (!ext4_has_feature_metadata_csum(sb))
276 		return 1;
277 
278 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
279 }
280 
281 __le32 ext4_superblock_csum(struct super_block *sb,
282 			    struct ext4_super_block *es)
283 {
284 	struct ext4_sb_info *sbi = EXT4_SB(sb);
285 	int offset = offsetof(struct ext4_super_block, s_checksum);
286 	__u32 csum;
287 
288 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
289 
290 	return cpu_to_le32(csum);
291 }
292 
293 static int ext4_superblock_csum_verify(struct super_block *sb,
294 				       struct ext4_super_block *es)
295 {
296 	if (!ext4_has_metadata_csum(sb))
297 		return 1;
298 
299 	return es->s_checksum == ext4_superblock_csum(sb, es);
300 }
301 
302 void ext4_superblock_csum_set(struct super_block *sb)
303 {
304 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
305 
306 	if (!ext4_has_metadata_csum(sb))
307 		return;
308 
309 	es->s_checksum = ext4_superblock_csum(sb, es);
310 }
311 
312 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
313 			       struct ext4_group_desc *bg)
314 {
315 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
316 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
317 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
318 }
319 
320 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
321 			       struct ext4_group_desc *bg)
322 {
323 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
324 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
325 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
326 }
327 
328 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
329 			      struct ext4_group_desc *bg)
330 {
331 	return le32_to_cpu(bg->bg_inode_table_lo) |
332 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
333 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
334 }
335 
336 __u32 ext4_free_group_clusters(struct super_block *sb,
337 			       struct ext4_group_desc *bg)
338 {
339 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
340 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
341 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
342 }
343 
344 __u32 ext4_free_inodes_count(struct super_block *sb,
345 			      struct ext4_group_desc *bg)
346 {
347 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
348 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
349 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
350 }
351 
352 __u32 ext4_used_dirs_count(struct super_block *sb,
353 			      struct ext4_group_desc *bg)
354 {
355 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
356 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
357 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
358 }
359 
360 __u32 ext4_itable_unused_count(struct super_block *sb,
361 			      struct ext4_group_desc *bg)
362 {
363 	return le16_to_cpu(bg->bg_itable_unused_lo) |
364 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
365 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
366 }
367 
368 void ext4_block_bitmap_set(struct super_block *sb,
369 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
370 {
371 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
372 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
373 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
374 }
375 
376 void ext4_inode_bitmap_set(struct super_block *sb,
377 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
378 {
379 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
380 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
381 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
382 }
383 
384 void ext4_inode_table_set(struct super_block *sb,
385 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
386 {
387 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
388 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
389 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
390 }
391 
392 void ext4_free_group_clusters_set(struct super_block *sb,
393 				  struct ext4_group_desc *bg, __u32 count)
394 {
395 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
396 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
397 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
398 }
399 
400 void ext4_free_inodes_set(struct super_block *sb,
401 			  struct ext4_group_desc *bg, __u32 count)
402 {
403 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
404 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
405 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
406 }
407 
408 void ext4_used_dirs_set(struct super_block *sb,
409 			  struct ext4_group_desc *bg, __u32 count)
410 {
411 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
412 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
413 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
414 }
415 
416 void ext4_itable_unused_set(struct super_block *sb,
417 			  struct ext4_group_desc *bg, __u32 count)
418 {
419 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
420 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
421 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
422 }
423 
424 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
425 {
426 	now = clamp_val(now, 0, (1ull << 40) - 1);
427 
428 	*lo = cpu_to_le32(lower_32_bits(now));
429 	*hi = upper_32_bits(now);
430 }
431 
432 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
433 {
434 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
435 }
436 #define ext4_update_tstamp(es, tstamp) \
437 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
438 			     ktime_get_real_seconds())
439 #define ext4_get_tstamp(es, tstamp) \
440 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
441 
442 /*
443  * The del_gendisk() function uninitializes the disk-specific data
444  * structures, including the bdi structure, without telling anyone
445  * else.  Once this happens, any attempt to call mark_buffer_dirty()
446  * (for example, by ext4_commit_super), will cause a kernel OOPS.
447  * This is a kludge to prevent these oops until we can put in a proper
448  * hook in del_gendisk() to inform the VFS and file system layers.
449  */
450 static int block_device_ejected(struct super_block *sb)
451 {
452 	struct inode *bd_inode = sb->s_bdev->bd_inode;
453 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
454 
455 	return bdi->dev == NULL;
456 }
457 
458 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
459 {
460 	struct super_block		*sb = journal->j_private;
461 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
462 	int				error = is_journal_aborted(journal);
463 	struct ext4_journal_cb_entry	*jce;
464 
465 	BUG_ON(txn->t_state == T_FINISHED);
466 
467 	ext4_process_freed_data(sb, txn->t_tid);
468 
469 	spin_lock(&sbi->s_md_lock);
470 	while (!list_empty(&txn->t_private_list)) {
471 		jce = list_entry(txn->t_private_list.next,
472 				 struct ext4_journal_cb_entry, jce_list);
473 		list_del_init(&jce->jce_list);
474 		spin_unlock(&sbi->s_md_lock);
475 		jce->jce_func(sb, jce, error);
476 		spin_lock(&sbi->s_md_lock);
477 	}
478 	spin_unlock(&sbi->s_md_lock);
479 }
480 
481 /*
482  * This writepage callback for write_cache_pages()
483  * takes care of a few cases after page cleaning.
484  *
485  * write_cache_pages() already checks for dirty pages
486  * and calls clear_page_dirty_for_io(), which we want,
487  * to write protect the pages.
488  *
489  * However, we may have to redirty a page (see below.)
490  */
491 static int ext4_journalled_writepage_callback(struct page *page,
492 					      struct writeback_control *wbc,
493 					      void *data)
494 {
495 	transaction_t *transaction = (transaction_t *) data;
496 	struct buffer_head *bh, *head;
497 	struct journal_head *jh;
498 
499 	bh = head = page_buffers(page);
500 	do {
501 		/*
502 		 * We have to redirty a page in these cases:
503 		 * 1) If buffer is dirty, it means the page was dirty because it
504 		 * contains a buffer that needs checkpointing. So the dirty bit
505 		 * needs to be preserved so that checkpointing writes the buffer
506 		 * properly.
507 		 * 2) If buffer is not part of the committing transaction
508 		 * (we may have just accidentally come across this buffer because
509 		 * inode range tracking is not exact) or if the currently running
510 		 * transaction already contains this buffer as well, dirty bit
511 		 * needs to be preserved so that the buffer gets writeprotected
512 		 * properly on running transaction's commit.
513 		 */
514 		jh = bh2jh(bh);
515 		if (buffer_dirty(bh) ||
516 		    (jh && (jh->b_transaction != transaction ||
517 			    jh->b_next_transaction))) {
518 			redirty_page_for_writepage(wbc, page);
519 			goto out;
520 		}
521 	} while ((bh = bh->b_this_page) != head);
522 
523 out:
524 	return AOP_WRITEPAGE_ACTIVATE;
525 }
526 
527 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
528 {
529 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
530 	struct writeback_control wbc = {
531 		.sync_mode =  WB_SYNC_ALL,
532 		.nr_to_write = LONG_MAX,
533 		.range_start = jinode->i_dirty_start,
534 		.range_end = jinode->i_dirty_end,
535         };
536 
537 	return write_cache_pages(mapping, &wbc,
538 				 ext4_journalled_writepage_callback,
539 				 jinode->i_transaction);
540 }
541 
542 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
543 {
544 	int ret;
545 
546 	if (ext4_should_journal_data(jinode->i_vfs_inode))
547 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
548 	else
549 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
550 
551 	return ret;
552 }
553 
554 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
555 {
556 	int ret = 0;
557 
558 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
559 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
560 
561 	return ret;
562 }
563 
564 static bool system_going_down(void)
565 {
566 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
567 		|| system_state == SYSTEM_RESTART;
568 }
569 
570 struct ext4_err_translation {
571 	int code;
572 	int errno;
573 };
574 
575 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
576 
577 static struct ext4_err_translation err_translation[] = {
578 	EXT4_ERR_TRANSLATE(EIO),
579 	EXT4_ERR_TRANSLATE(ENOMEM),
580 	EXT4_ERR_TRANSLATE(EFSBADCRC),
581 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
582 	EXT4_ERR_TRANSLATE(ENOSPC),
583 	EXT4_ERR_TRANSLATE(ENOKEY),
584 	EXT4_ERR_TRANSLATE(EROFS),
585 	EXT4_ERR_TRANSLATE(EFBIG),
586 	EXT4_ERR_TRANSLATE(EEXIST),
587 	EXT4_ERR_TRANSLATE(ERANGE),
588 	EXT4_ERR_TRANSLATE(EOVERFLOW),
589 	EXT4_ERR_TRANSLATE(EBUSY),
590 	EXT4_ERR_TRANSLATE(ENOTDIR),
591 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
592 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
593 	EXT4_ERR_TRANSLATE(EFAULT),
594 };
595 
596 static int ext4_errno_to_code(int errno)
597 {
598 	int i;
599 
600 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
601 		if (err_translation[i].errno == errno)
602 			return err_translation[i].code;
603 	return EXT4_ERR_UNKNOWN;
604 }
605 
606 static void save_error_info(struct super_block *sb, int error,
607 			    __u32 ino, __u64 block,
608 			    const char *func, unsigned int line)
609 {
610 	struct ext4_sb_info *sbi = EXT4_SB(sb);
611 
612 	/* We default to EFSCORRUPTED error... */
613 	if (error == 0)
614 		error = EFSCORRUPTED;
615 
616 	spin_lock(&sbi->s_error_lock);
617 	sbi->s_add_error_count++;
618 	sbi->s_last_error_code = error;
619 	sbi->s_last_error_line = line;
620 	sbi->s_last_error_ino = ino;
621 	sbi->s_last_error_block = block;
622 	sbi->s_last_error_func = func;
623 	sbi->s_last_error_time = ktime_get_real_seconds();
624 	if (!sbi->s_first_error_time) {
625 		sbi->s_first_error_code = error;
626 		sbi->s_first_error_line = line;
627 		sbi->s_first_error_ino = ino;
628 		sbi->s_first_error_block = block;
629 		sbi->s_first_error_func = func;
630 		sbi->s_first_error_time = sbi->s_last_error_time;
631 	}
632 	spin_unlock(&sbi->s_error_lock);
633 }
634 
635 /* Deal with the reporting of failure conditions on a filesystem such as
636  * inconsistencies detected or read IO failures.
637  *
638  * On ext2, we can store the error state of the filesystem in the
639  * superblock.  That is not possible on ext4, because we may have other
640  * write ordering constraints on the superblock which prevent us from
641  * writing it out straight away; and given that the journal is about to
642  * be aborted, we can't rely on the current, or future, transactions to
643  * write out the superblock safely.
644  *
645  * We'll just use the jbd2_journal_abort() error code to record an error in
646  * the journal instead.  On recovery, the journal will complain about
647  * that error until we've noted it down and cleared it.
648  *
649  * If force_ro is set, we unconditionally force the filesystem into an
650  * ABORT|READONLY state, unless the error response on the fs has been set to
651  * panic in which case we take the easy way out and panic immediately. This is
652  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
653  * at a critical moment in log management.
654  */
655 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
656 			      __u32 ino, __u64 block,
657 			      const char *func, unsigned int line)
658 {
659 	journal_t *journal = EXT4_SB(sb)->s_journal;
660 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
661 
662 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
663 	if (test_opt(sb, WARN_ON_ERROR))
664 		WARN_ON_ONCE(1);
665 
666 	if (!continue_fs && !sb_rdonly(sb)) {
667 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
668 		if (journal)
669 			jbd2_journal_abort(journal, -EIO);
670 	}
671 
672 	if (!bdev_read_only(sb->s_bdev)) {
673 		save_error_info(sb, error, ino, block, func, line);
674 		/*
675 		 * In case the fs should keep running, we need to writeout
676 		 * superblock through the journal. Due to lock ordering
677 		 * constraints, it may not be safe to do it right here so we
678 		 * defer superblock flushing to a workqueue.
679 		 */
680 		if (continue_fs && journal)
681 			schedule_work(&EXT4_SB(sb)->s_error_work);
682 		else
683 			ext4_commit_super(sb);
684 	}
685 
686 	/*
687 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
688 	 * could panic during 'reboot -f' as the underlying device got already
689 	 * disabled.
690 	 */
691 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
692 		panic("EXT4-fs (device %s): panic forced after error\n",
693 			sb->s_id);
694 	}
695 
696 	if (sb_rdonly(sb) || continue_fs)
697 		return;
698 
699 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
700 	/*
701 	 * Make sure updated value of ->s_mount_flags will be visible before
702 	 * ->s_flags update
703 	 */
704 	smp_wmb();
705 	sb->s_flags |= SB_RDONLY;
706 }
707 
708 static void flush_stashed_error_work(struct work_struct *work)
709 {
710 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
711 						s_error_work);
712 	journal_t *journal = sbi->s_journal;
713 	handle_t *handle;
714 
715 	/*
716 	 * If the journal is still running, we have to write out superblock
717 	 * through the journal to avoid collisions of other journalled sb
718 	 * updates.
719 	 *
720 	 * We use directly jbd2 functions here to avoid recursing back into
721 	 * ext4 error handling code during handling of previous errors.
722 	 */
723 	if (!sb_rdonly(sbi->s_sb) && journal) {
724 		struct buffer_head *sbh = sbi->s_sbh;
725 		handle = jbd2_journal_start(journal, 1);
726 		if (IS_ERR(handle))
727 			goto write_directly;
728 		if (jbd2_journal_get_write_access(handle, sbh)) {
729 			jbd2_journal_stop(handle);
730 			goto write_directly;
731 		}
732 		ext4_update_super(sbi->s_sb);
733 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
734 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
735 				 "superblock detected");
736 			clear_buffer_write_io_error(sbh);
737 			set_buffer_uptodate(sbh);
738 		}
739 
740 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
741 			jbd2_journal_stop(handle);
742 			goto write_directly;
743 		}
744 		jbd2_journal_stop(handle);
745 		ext4_notify_error_sysfs(sbi);
746 		return;
747 	}
748 write_directly:
749 	/*
750 	 * Write through journal failed. Write sb directly to get error info
751 	 * out and hope for the best.
752 	 */
753 	ext4_commit_super(sbi->s_sb);
754 	ext4_notify_error_sysfs(sbi);
755 }
756 
757 #define ext4_error_ratelimit(sb)					\
758 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
759 			     "EXT4-fs error")
760 
761 void __ext4_error(struct super_block *sb, const char *function,
762 		  unsigned int line, bool force_ro, int error, __u64 block,
763 		  const char *fmt, ...)
764 {
765 	struct va_format vaf;
766 	va_list args;
767 
768 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
769 		return;
770 
771 	trace_ext4_error(sb, function, line);
772 	if (ext4_error_ratelimit(sb)) {
773 		va_start(args, fmt);
774 		vaf.fmt = fmt;
775 		vaf.va = &args;
776 		printk(KERN_CRIT
777 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
778 		       sb->s_id, function, line, current->comm, &vaf);
779 		va_end(args);
780 	}
781 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
782 
783 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
784 }
785 
786 void __ext4_error_inode(struct inode *inode, const char *function,
787 			unsigned int line, ext4_fsblk_t block, int error,
788 			const char *fmt, ...)
789 {
790 	va_list args;
791 	struct va_format vaf;
792 
793 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
794 		return;
795 
796 	trace_ext4_error(inode->i_sb, function, line);
797 	if (ext4_error_ratelimit(inode->i_sb)) {
798 		va_start(args, fmt);
799 		vaf.fmt = fmt;
800 		vaf.va = &args;
801 		if (block)
802 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
803 			       "inode #%lu: block %llu: comm %s: %pV\n",
804 			       inode->i_sb->s_id, function, line, inode->i_ino,
805 			       block, current->comm, &vaf);
806 		else
807 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
808 			       "inode #%lu: comm %s: %pV\n",
809 			       inode->i_sb->s_id, function, line, inode->i_ino,
810 			       current->comm, &vaf);
811 		va_end(args);
812 	}
813 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
814 
815 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
816 			  function, line);
817 }
818 
819 void __ext4_error_file(struct file *file, const char *function,
820 		       unsigned int line, ext4_fsblk_t block,
821 		       const char *fmt, ...)
822 {
823 	va_list args;
824 	struct va_format vaf;
825 	struct inode *inode = file_inode(file);
826 	char pathname[80], *path;
827 
828 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
829 		return;
830 
831 	trace_ext4_error(inode->i_sb, function, line);
832 	if (ext4_error_ratelimit(inode->i_sb)) {
833 		path = file_path(file, pathname, sizeof(pathname));
834 		if (IS_ERR(path))
835 			path = "(unknown)";
836 		va_start(args, fmt);
837 		vaf.fmt = fmt;
838 		vaf.va = &args;
839 		if (block)
840 			printk(KERN_CRIT
841 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
842 			       "block %llu: comm %s: path %s: %pV\n",
843 			       inode->i_sb->s_id, function, line, inode->i_ino,
844 			       block, current->comm, path, &vaf);
845 		else
846 			printk(KERN_CRIT
847 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
848 			       "comm %s: path %s: %pV\n",
849 			       inode->i_sb->s_id, function, line, inode->i_ino,
850 			       current->comm, path, &vaf);
851 		va_end(args);
852 	}
853 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
854 
855 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
856 			  function, line);
857 }
858 
859 const char *ext4_decode_error(struct super_block *sb, int errno,
860 			      char nbuf[16])
861 {
862 	char *errstr = NULL;
863 
864 	switch (errno) {
865 	case -EFSCORRUPTED:
866 		errstr = "Corrupt filesystem";
867 		break;
868 	case -EFSBADCRC:
869 		errstr = "Filesystem failed CRC";
870 		break;
871 	case -EIO:
872 		errstr = "IO failure";
873 		break;
874 	case -ENOMEM:
875 		errstr = "Out of memory";
876 		break;
877 	case -EROFS:
878 		if (!sb || (EXT4_SB(sb)->s_journal &&
879 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
880 			errstr = "Journal has aborted";
881 		else
882 			errstr = "Readonly filesystem";
883 		break;
884 	default:
885 		/* If the caller passed in an extra buffer for unknown
886 		 * errors, textualise them now.  Else we just return
887 		 * NULL. */
888 		if (nbuf) {
889 			/* Check for truncated error codes... */
890 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
891 				errstr = nbuf;
892 		}
893 		break;
894 	}
895 
896 	return errstr;
897 }
898 
899 /* __ext4_std_error decodes expected errors from journaling functions
900  * automatically and invokes the appropriate error response.  */
901 
902 void __ext4_std_error(struct super_block *sb, const char *function,
903 		      unsigned int line, int errno)
904 {
905 	char nbuf[16];
906 	const char *errstr;
907 
908 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
909 		return;
910 
911 	/* Special case: if the error is EROFS, and we're not already
912 	 * inside a transaction, then there's really no point in logging
913 	 * an error. */
914 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
915 		return;
916 
917 	if (ext4_error_ratelimit(sb)) {
918 		errstr = ext4_decode_error(sb, errno, nbuf);
919 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
920 		       sb->s_id, function, line, errstr);
921 	}
922 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
923 
924 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
925 }
926 
927 void __ext4_msg(struct super_block *sb,
928 		const char *prefix, const char *fmt, ...)
929 {
930 	struct va_format vaf;
931 	va_list args;
932 
933 	if (sb) {
934 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
935 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
936 				  "EXT4-fs"))
937 			return;
938 	}
939 
940 	va_start(args, fmt);
941 	vaf.fmt = fmt;
942 	vaf.va = &args;
943 	if (sb)
944 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
945 	else
946 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
947 	va_end(args);
948 }
949 
950 static int ext4_warning_ratelimit(struct super_block *sb)
951 {
952 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
953 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
954 			    "EXT4-fs warning");
955 }
956 
957 void __ext4_warning(struct super_block *sb, const char *function,
958 		    unsigned int line, const char *fmt, ...)
959 {
960 	struct va_format vaf;
961 	va_list args;
962 
963 	if (!ext4_warning_ratelimit(sb))
964 		return;
965 
966 	va_start(args, fmt);
967 	vaf.fmt = fmt;
968 	vaf.va = &args;
969 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
970 	       sb->s_id, function, line, &vaf);
971 	va_end(args);
972 }
973 
974 void __ext4_warning_inode(const struct inode *inode, const char *function,
975 			  unsigned int line, const char *fmt, ...)
976 {
977 	struct va_format vaf;
978 	va_list args;
979 
980 	if (!ext4_warning_ratelimit(inode->i_sb))
981 		return;
982 
983 	va_start(args, fmt);
984 	vaf.fmt = fmt;
985 	vaf.va = &args;
986 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
987 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
988 	       function, line, inode->i_ino, current->comm, &vaf);
989 	va_end(args);
990 }
991 
992 void __ext4_grp_locked_error(const char *function, unsigned int line,
993 			     struct super_block *sb, ext4_group_t grp,
994 			     unsigned long ino, ext4_fsblk_t block,
995 			     const char *fmt, ...)
996 __releases(bitlock)
997 __acquires(bitlock)
998 {
999 	struct va_format vaf;
1000 	va_list args;
1001 
1002 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
1003 		return;
1004 
1005 	trace_ext4_error(sb, function, line);
1006 	if (ext4_error_ratelimit(sb)) {
1007 		va_start(args, fmt);
1008 		vaf.fmt = fmt;
1009 		vaf.va = &args;
1010 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1011 		       sb->s_id, function, line, grp);
1012 		if (ino)
1013 			printk(KERN_CONT "inode %lu: ", ino);
1014 		if (block)
1015 			printk(KERN_CONT "block %llu:",
1016 			       (unsigned long long) block);
1017 		printk(KERN_CONT "%pV\n", &vaf);
1018 		va_end(args);
1019 	}
1020 
1021 	if (test_opt(sb, ERRORS_CONT)) {
1022 		if (test_opt(sb, WARN_ON_ERROR))
1023 			WARN_ON_ONCE(1);
1024 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1025 		if (!bdev_read_only(sb->s_bdev)) {
1026 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1027 					line);
1028 			schedule_work(&EXT4_SB(sb)->s_error_work);
1029 		}
1030 		return;
1031 	}
1032 	ext4_unlock_group(sb, grp);
1033 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1034 	/*
1035 	 * We only get here in the ERRORS_RO case; relocking the group
1036 	 * may be dangerous, but nothing bad will happen since the
1037 	 * filesystem will have already been marked read/only and the
1038 	 * journal has been aborted.  We return 1 as a hint to callers
1039 	 * who might what to use the return value from
1040 	 * ext4_grp_locked_error() to distinguish between the
1041 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1042 	 * aggressively from the ext4 function in question, with a
1043 	 * more appropriate error code.
1044 	 */
1045 	ext4_lock_group(sb, grp);
1046 	return;
1047 }
1048 
1049 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1050 				     ext4_group_t group,
1051 				     unsigned int flags)
1052 {
1053 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1054 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1055 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1056 	int ret;
1057 
1058 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1059 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1060 					    &grp->bb_state);
1061 		if (!ret)
1062 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1063 					   grp->bb_free);
1064 	}
1065 
1066 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1067 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1068 					    &grp->bb_state);
1069 		if (!ret && gdp) {
1070 			int count;
1071 
1072 			count = ext4_free_inodes_count(sb, gdp);
1073 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1074 					   count);
1075 		}
1076 	}
1077 }
1078 
1079 void ext4_update_dynamic_rev(struct super_block *sb)
1080 {
1081 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1082 
1083 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1084 		return;
1085 
1086 	ext4_warning(sb,
1087 		     "updating to rev %d because of new feature flag, "
1088 		     "running e2fsck is recommended",
1089 		     EXT4_DYNAMIC_REV);
1090 
1091 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1092 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1093 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1094 	/* leave es->s_feature_*compat flags alone */
1095 	/* es->s_uuid will be set by e2fsck if empty */
1096 
1097 	/*
1098 	 * The rest of the superblock fields should be zero, and if not it
1099 	 * means they are likely already in use, so leave them alone.  We
1100 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1101 	 */
1102 }
1103 
1104 /*
1105  * Open the external journal device
1106  */
1107 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1108 {
1109 	struct block_device *bdev;
1110 
1111 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1112 	if (IS_ERR(bdev))
1113 		goto fail;
1114 	return bdev;
1115 
1116 fail:
1117 	ext4_msg(sb, KERN_ERR,
1118 		 "failed to open journal device unknown-block(%u,%u) %ld",
1119 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1120 	return NULL;
1121 }
1122 
1123 /*
1124  * Release the journal device
1125  */
1126 static void ext4_blkdev_put(struct block_device *bdev)
1127 {
1128 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1129 }
1130 
1131 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1132 {
1133 	struct block_device *bdev;
1134 	bdev = sbi->s_journal_bdev;
1135 	if (bdev) {
1136 		ext4_blkdev_put(bdev);
1137 		sbi->s_journal_bdev = NULL;
1138 	}
1139 }
1140 
1141 static inline struct inode *orphan_list_entry(struct list_head *l)
1142 {
1143 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1144 }
1145 
1146 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1147 {
1148 	struct list_head *l;
1149 
1150 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1151 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1152 
1153 	printk(KERN_ERR "sb_info orphan list:\n");
1154 	list_for_each(l, &sbi->s_orphan) {
1155 		struct inode *inode = orphan_list_entry(l);
1156 		printk(KERN_ERR "  "
1157 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1158 		       inode->i_sb->s_id, inode->i_ino, inode,
1159 		       inode->i_mode, inode->i_nlink,
1160 		       NEXT_ORPHAN(inode));
1161 	}
1162 }
1163 
1164 #ifdef CONFIG_QUOTA
1165 static int ext4_quota_off(struct super_block *sb, int type);
1166 
1167 static inline void ext4_quota_off_umount(struct super_block *sb)
1168 {
1169 	int type;
1170 
1171 	/* Use our quota_off function to clear inode flags etc. */
1172 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1173 		ext4_quota_off(sb, type);
1174 }
1175 
1176 /*
1177  * This is a helper function which is used in the mount/remount
1178  * codepaths (which holds s_umount) to fetch the quota file name.
1179  */
1180 static inline char *get_qf_name(struct super_block *sb,
1181 				struct ext4_sb_info *sbi,
1182 				int type)
1183 {
1184 	return rcu_dereference_protected(sbi->s_qf_names[type],
1185 					 lockdep_is_held(&sb->s_umount));
1186 }
1187 #else
1188 static inline void ext4_quota_off_umount(struct super_block *sb)
1189 {
1190 }
1191 #endif
1192 
1193 static void ext4_put_super(struct super_block *sb)
1194 {
1195 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1196 	struct ext4_super_block *es = sbi->s_es;
1197 	struct buffer_head **group_desc;
1198 	struct flex_groups **flex_groups;
1199 	int aborted = 0;
1200 	int i, err;
1201 
1202 	/*
1203 	 * Unregister sysfs before destroying jbd2 journal.
1204 	 * Since we could still access attr_journal_task attribute via sysfs
1205 	 * path which could have sbi->s_journal->j_task as NULL
1206 	 * Unregister sysfs before flush sbi->s_error_work.
1207 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1208 	 * read metadata verify failed then will queue error work.
1209 	 * flush_stashed_error_work will call start_this_handle may trigger
1210 	 * BUG_ON.
1211 	 */
1212 	ext4_unregister_sysfs(sb);
1213 
1214 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1215 		ext4_msg(sb, KERN_INFO, "unmounting filesystem.");
1216 
1217 	ext4_unregister_li_request(sb);
1218 	ext4_quota_off_umount(sb);
1219 
1220 	flush_work(&sbi->s_error_work);
1221 	destroy_workqueue(sbi->rsv_conversion_wq);
1222 	ext4_release_orphan_info(sb);
1223 
1224 	if (sbi->s_journal) {
1225 		aborted = is_journal_aborted(sbi->s_journal);
1226 		err = jbd2_journal_destroy(sbi->s_journal);
1227 		sbi->s_journal = NULL;
1228 		if ((err < 0) && !aborted) {
1229 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1230 		}
1231 	}
1232 
1233 	ext4_es_unregister_shrinker(sbi);
1234 	del_timer_sync(&sbi->s_err_report);
1235 	ext4_release_system_zone(sb);
1236 	ext4_mb_release(sb);
1237 	ext4_ext_release(sb);
1238 
1239 	if (!sb_rdonly(sb) && !aborted) {
1240 		ext4_clear_feature_journal_needs_recovery(sb);
1241 		ext4_clear_feature_orphan_present(sb);
1242 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1243 	}
1244 	if (!sb_rdonly(sb))
1245 		ext4_commit_super(sb);
1246 
1247 	rcu_read_lock();
1248 	group_desc = rcu_dereference(sbi->s_group_desc);
1249 	for (i = 0; i < sbi->s_gdb_count; i++)
1250 		brelse(group_desc[i]);
1251 	kvfree(group_desc);
1252 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1253 	if (flex_groups) {
1254 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1255 			kvfree(flex_groups[i]);
1256 		kvfree(flex_groups);
1257 	}
1258 	rcu_read_unlock();
1259 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1260 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1261 	percpu_counter_destroy(&sbi->s_dirs_counter);
1262 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1263 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1264 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1265 #ifdef CONFIG_QUOTA
1266 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1267 		kfree(get_qf_name(sb, sbi, i));
1268 #endif
1269 
1270 	/* Debugging code just in case the in-memory inode orphan list
1271 	 * isn't empty.  The on-disk one can be non-empty if we've
1272 	 * detected an error and taken the fs readonly, but the
1273 	 * in-memory list had better be clean by this point. */
1274 	if (!list_empty(&sbi->s_orphan))
1275 		dump_orphan_list(sb, sbi);
1276 	ASSERT(list_empty(&sbi->s_orphan));
1277 
1278 	sync_blockdev(sb->s_bdev);
1279 	invalidate_bdev(sb->s_bdev);
1280 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1281 		/*
1282 		 * Invalidate the journal device's buffers.  We don't want them
1283 		 * floating about in memory - the physical journal device may
1284 		 * hotswapped, and it breaks the `ro-after' testing code.
1285 		 */
1286 		sync_blockdev(sbi->s_journal_bdev);
1287 		invalidate_bdev(sbi->s_journal_bdev);
1288 		ext4_blkdev_remove(sbi);
1289 	}
1290 
1291 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1292 	sbi->s_ea_inode_cache = NULL;
1293 
1294 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1295 	sbi->s_ea_block_cache = NULL;
1296 
1297 	ext4_stop_mmpd(sbi);
1298 
1299 	brelse(sbi->s_sbh);
1300 	sb->s_fs_info = NULL;
1301 	/*
1302 	 * Now that we are completely done shutting down the
1303 	 * superblock, we need to actually destroy the kobject.
1304 	 */
1305 	kobject_put(&sbi->s_kobj);
1306 	wait_for_completion(&sbi->s_kobj_unregister);
1307 	if (sbi->s_chksum_driver)
1308 		crypto_free_shash(sbi->s_chksum_driver);
1309 	kfree(sbi->s_blockgroup_lock);
1310 	fs_put_dax(sbi->s_daxdev);
1311 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1312 #if IS_ENABLED(CONFIG_UNICODE)
1313 	utf8_unload(sb->s_encoding);
1314 #endif
1315 	kfree(sbi);
1316 }
1317 
1318 static struct kmem_cache *ext4_inode_cachep;
1319 
1320 /*
1321  * Called inside transaction, so use GFP_NOFS
1322  */
1323 static struct inode *ext4_alloc_inode(struct super_block *sb)
1324 {
1325 	struct ext4_inode_info *ei;
1326 
1327 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1328 	if (!ei)
1329 		return NULL;
1330 
1331 	inode_set_iversion(&ei->vfs_inode, 1);
1332 	spin_lock_init(&ei->i_raw_lock);
1333 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1334 	atomic_set(&ei->i_prealloc_active, 0);
1335 	spin_lock_init(&ei->i_prealloc_lock);
1336 	ext4_es_init_tree(&ei->i_es_tree);
1337 	rwlock_init(&ei->i_es_lock);
1338 	INIT_LIST_HEAD(&ei->i_es_list);
1339 	ei->i_es_all_nr = 0;
1340 	ei->i_es_shk_nr = 0;
1341 	ei->i_es_shrink_lblk = 0;
1342 	ei->i_reserved_data_blocks = 0;
1343 	spin_lock_init(&(ei->i_block_reservation_lock));
1344 	ext4_init_pending_tree(&ei->i_pending_tree);
1345 #ifdef CONFIG_QUOTA
1346 	ei->i_reserved_quota = 0;
1347 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1348 #endif
1349 	ei->jinode = NULL;
1350 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1351 	spin_lock_init(&ei->i_completed_io_lock);
1352 	ei->i_sync_tid = 0;
1353 	ei->i_datasync_tid = 0;
1354 	atomic_set(&ei->i_unwritten, 0);
1355 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1356 	ext4_fc_init_inode(&ei->vfs_inode);
1357 	mutex_init(&ei->i_fc_lock);
1358 	return &ei->vfs_inode;
1359 }
1360 
1361 static int ext4_drop_inode(struct inode *inode)
1362 {
1363 	int drop = generic_drop_inode(inode);
1364 
1365 	if (!drop)
1366 		drop = fscrypt_drop_inode(inode);
1367 
1368 	trace_ext4_drop_inode(inode, drop);
1369 	return drop;
1370 }
1371 
1372 static void ext4_free_in_core_inode(struct inode *inode)
1373 {
1374 	fscrypt_free_inode(inode);
1375 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1376 		pr_warn("%s: inode %ld still in fc list",
1377 			__func__, inode->i_ino);
1378 	}
1379 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1380 }
1381 
1382 static void ext4_destroy_inode(struct inode *inode)
1383 {
1384 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1385 		ext4_msg(inode->i_sb, KERN_ERR,
1386 			 "Inode %lu (%p): orphan list check failed!",
1387 			 inode->i_ino, EXT4_I(inode));
1388 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1389 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1390 				true);
1391 		dump_stack();
1392 	}
1393 
1394 	if (EXT4_I(inode)->i_reserved_data_blocks)
1395 		ext4_msg(inode->i_sb, KERN_ERR,
1396 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1397 			 inode->i_ino, EXT4_I(inode),
1398 			 EXT4_I(inode)->i_reserved_data_blocks);
1399 }
1400 
1401 static void init_once(void *foo)
1402 {
1403 	struct ext4_inode_info *ei = foo;
1404 
1405 	INIT_LIST_HEAD(&ei->i_orphan);
1406 	init_rwsem(&ei->xattr_sem);
1407 	init_rwsem(&ei->i_data_sem);
1408 	inode_init_once(&ei->vfs_inode);
1409 	ext4_fc_init_inode(&ei->vfs_inode);
1410 }
1411 
1412 static int __init init_inodecache(void)
1413 {
1414 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1415 				sizeof(struct ext4_inode_info), 0,
1416 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1417 					SLAB_ACCOUNT),
1418 				offsetof(struct ext4_inode_info, i_data),
1419 				sizeof_field(struct ext4_inode_info, i_data),
1420 				init_once);
1421 	if (ext4_inode_cachep == NULL)
1422 		return -ENOMEM;
1423 	return 0;
1424 }
1425 
1426 static void destroy_inodecache(void)
1427 {
1428 	/*
1429 	 * Make sure all delayed rcu free inodes are flushed before we
1430 	 * destroy cache.
1431 	 */
1432 	rcu_barrier();
1433 	kmem_cache_destroy(ext4_inode_cachep);
1434 }
1435 
1436 void ext4_clear_inode(struct inode *inode)
1437 {
1438 	ext4_fc_del(inode);
1439 	invalidate_inode_buffers(inode);
1440 	clear_inode(inode);
1441 	ext4_discard_preallocations(inode, 0);
1442 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1443 	dquot_drop(inode);
1444 	if (EXT4_I(inode)->jinode) {
1445 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1446 					       EXT4_I(inode)->jinode);
1447 		jbd2_free_inode(EXT4_I(inode)->jinode);
1448 		EXT4_I(inode)->jinode = NULL;
1449 	}
1450 	fscrypt_put_encryption_info(inode);
1451 	fsverity_cleanup_inode(inode);
1452 }
1453 
1454 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1455 					u64 ino, u32 generation)
1456 {
1457 	struct inode *inode;
1458 
1459 	/*
1460 	 * Currently we don't know the generation for parent directory, so
1461 	 * a generation of 0 means "accept any"
1462 	 */
1463 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1464 	if (IS_ERR(inode))
1465 		return ERR_CAST(inode);
1466 	if (generation && inode->i_generation != generation) {
1467 		iput(inode);
1468 		return ERR_PTR(-ESTALE);
1469 	}
1470 
1471 	return inode;
1472 }
1473 
1474 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1475 					int fh_len, int fh_type)
1476 {
1477 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1478 				    ext4_nfs_get_inode);
1479 }
1480 
1481 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1482 					int fh_len, int fh_type)
1483 {
1484 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1485 				    ext4_nfs_get_inode);
1486 }
1487 
1488 static int ext4_nfs_commit_metadata(struct inode *inode)
1489 {
1490 	struct writeback_control wbc = {
1491 		.sync_mode = WB_SYNC_ALL
1492 	};
1493 
1494 	trace_ext4_nfs_commit_metadata(inode);
1495 	return ext4_write_inode(inode, &wbc);
1496 }
1497 
1498 #ifdef CONFIG_QUOTA
1499 static const char * const quotatypes[] = INITQFNAMES;
1500 #define QTYPE2NAME(t) (quotatypes[t])
1501 
1502 static int ext4_write_dquot(struct dquot *dquot);
1503 static int ext4_acquire_dquot(struct dquot *dquot);
1504 static int ext4_release_dquot(struct dquot *dquot);
1505 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1506 static int ext4_write_info(struct super_block *sb, int type);
1507 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1508 			 const struct path *path);
1509 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1510 			       size_t len, loff_t off);
1511 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1512 				const char *data, size_t len, loff_t off);
1513 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1514 			     unsigned int flags);
1515 
1516 static struct dquot **ext4_get_dquots(struct inode *inode)
1517 {
1518 	return EXT4_I(inode)->i_dquot;
1519 }
1520 
1521 static const struct dquot_operations ext4_quota_operations = {
1522 	.get_reserved_space	= ext4_get_reserved_space,
1523 	.write_dquot		= ext4_write_dquot,
1524 	.acquire_dquot		= ext4_acquire_dquot,
1525 	.release_dquot		= ext4_release_dquot,
1526 	.mark_dirty		= ext4_mark_dquot_dirty,
1527 	.write_info		= ext4_write_info,
1528 	.alloc_dquot		= dquot_alloc,
1529 	.destroy_dquot		= dquot_destroy,
1530 	.get_projid		= ext4_get_projid,
1531 	.get_inode_usage	= ext4_get_inode_usage,
1532 	.get_next_id		= dquot_get_next_id,
1533 };
1534 
1535 static const struct quotactl_ops ext4_qctl_operations = {
1536 	.quota_on	= ext4_quota_on,
1537 	.quota_off	= ext4_quota_off,
1538 	.quota_sync	= dquot_quota_sync,
1539 	.get_state	= dquot_get_state,
1540 	.set_info	= dquot_set_dqinfo,
1541 	.get_dqblk	= dquot_get_dqblk,
1542 	.set_dqblk	= dquot_set_dqblk,
1543 	.get_nextdqblk	= dquot_get_next_dqblk,
1544 };
1545 #endif
1546 
1547 static const struct super_operations ext4_sops = {
1548 	.alloc_inode	= ext4_alloc_inode,
1549 	.free_inode	= ext4_free_in_core_inode,
1550 	.destroy_inode	= ext4_destroy_inode,
1551 	.write_inode	= ext4_write_inode,
1552 	.dirty_inode	= ext4_dirty_inode,
1553 	.drop_inode	= ext4_drop_inode,
1554 	.evict_inode	= ext4_evict_inode,
1555 	.put_super	= ext4_put_super,
1556 	.sync_fs	= ext4_sync_fs,
1557 	.freeze_fs	= ext4_freeze,
1558 	.unfreeze_fs	= ext4_unfreeze,
1559 	.statfs		= ext4_statfs,
1560 	.show_options	= ext4_show_options,
1561 #ifdef CONFIG_QUOTA
1562 	.quota_read	= ext4_quota_read,
1563 	.quota_write	= ext4_quota_write,
1564 	.get_dquots	= ext4_get_dquots,
1565 #endif
1566 };
1567 
1568 static const struct export_operations ext4_export_ops = {
1569 	.fh_to_dentry = ext4_fh_to_dentry,
1570 	.fh_to_parent = ext4_fh_to_parent,
1571 	.get_parent = ext4_get_parent,
1572 	.commit_metadata = ext4_nfs_commit_metadata,
1573 };
1574 
1575 enum {
1576 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1577 	Opt_resgid, Opt_resuid, Opt_sb,
1578 	Opt_nouid32, Opt_debug, Opt_removed,
1579 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1580 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1581 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1582 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1583 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1584 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1585 	Opt_inlinecrypt,
1586 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1587 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1588 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1589 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1590 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1591 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1592 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1593 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1594 	Opt_dioread_nolock, Opt_dioread_lock,
1595 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1596 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1597 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1598 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1599 #ifdef CONFIG_EXT4_DEBUG
1600 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1601 #endif
1602 };
1603 
1604 static const struct constant_table ext4_param_errors[] = {
1605 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1606 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1607 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1608 	{}
1609 };
1610 
1611 static const struct constant_table ext4_param_data[] = {
1612 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1613 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1614 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1615 	{}
1616 };
1617 
1618 static const struct constant_table ext4_param_data_err[] = {
1619 	{"abort",	Opt_data_err_abort},
1620 	{"ignore",	Opt_data_err_ignore},
1621 	{}
1622 };
1623 
1624 static const struct constant_table ext4_param_jqfmt[] = {
1625 	{"vfsold",	QFMT_VFS_OLD},
1626 	{"vfsv0",	QFMT_VFS_V0},
1627 	{"vfsv1",	QFMT_VFS_V1},
1628 	{}
1629 };
1630 
1631 static const struct constant_table ext4_param_dax[] = {
1632 	{"always",	Opt_dax_always},
1633 	{"inode",	Opt_dax_inode},
1634 	{"never",	Opt_dax_never},
1635 	{}
1636 };
1637 
1638 /* String parameter that allows empty argument */
1639 #define fsparam_string_empty(NAME, OPT) \
1640 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1641 
1642 /*
1643  * Mount option specification
1644  * We don't use fsparam_flag_no because of the way we set the
1645  * options and the way we show them in _ext4_show_options(). To
1646  * keep the changes to a minimum, let's keep the negative options
1647  * separate for now.
1648  */
1649 static const struct fs_parameter_spec ext4_param_specs[] = {
1650 	fsparam_flag	("bsddf",		Opt_bsd_df),
1651 	fsparam_flag	("minixdf",		Opt_minix_df),
1652 	fsparam_flag	("grpid",		Opt_grpid),
1653 	fsparam_flag	("bsdgroups",		Opt_grpid),
1654 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1655 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1656 	fsparam_u32	("resgid",		Opt_resgid),
1657 	fsparam_u32	("resuid",		Opt_resuid),
1658 	fsparam_u32	("sb",			Opt_sb),
1659 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1660 	fsparam_flag	("nouid32",		Opt_nouid32),
1661 	fsparam_flag	("debug",		Opt_debug),
1662 	fsparam_flag	("oldalloc",		Opt_removed),
1663 	fsparam_flag	("orlov",		Opt_removed),
1664 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1665 	fsparam_flag	("nouser_xattr",	Opt_nouser_xattr),
1666 	fsparam_flag	("acl",			Opt_acl),
1667 	fsparam_flag	("noacl",		Opt_noacl),
1668 	fsparam_flag	("norecovery",		Opt_noload),
1669 	fsparam_flag	("noload",		Opt_noload),
1670 	fsparam_flag	("bh",			Opt_removed),
1671 	fsparam_flag	("nobh",		Opt_removed),
1672 	fsparam_u32	("commit",		Opt_commit),
1673 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1674 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1675 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1676 	fsparam_bdev	("journal_path",	Opt_journal_path),
1677 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1678 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1679 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1680 	fsparam_flag	("abort",		Opt_abort),
1681 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1682 	fsparam_enum	("data_err",		Opt_data_err,
1683 						ext4_param_data_err),
1684 	fsparam_string_empty
1685 			("usrjquota",		Opt_usrjquota),
1686 	fsparam_string_empty
1687 			("grpjquota",		Opt_grpjquota),
1688 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1689 	fsparam_flag	("grpquota",		Opt_grpquota),
1690 	fsparam_flag	("quota",		Opt_quota),
1691 	fsparam_flag	("noquota",		Opt_noquota),
1692 	fsparam_flag	("usrquota",		Opt_usrquota),
1693 	fsparam_flag	("prjquota",		Opt_prjquota),
1694 	fsparam_flag	("barrier",		Opt_barrier),
1695 	fsparam_u32	("barrier",		Opt_barrier),
1696 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1697 	fsparam_flag	("i_version",		Opt_i_version),
1698 	fsparam_flag	("dax",			Opt_dax),
1699 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1700 	fsparam_u32	("stripe",		Opt_stripe),
1701 	fsparam_flag	("delalloc",		Opt_delalloc),
1702 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1703 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1704 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1705 	fsparam_u32	("debug_want_extra_isize",
1706 						Opt_debug_want_extra_isize),
1707 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1708 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1709 	fsparam_flag	("block_validity",	Opt_block_validity),
1710 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1711 	fsparam_u32	("inode_readahead_blks",
1712 						Opt_inode_readahead_blks),
1713 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1714 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1715 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1716 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1717 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1718 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1719 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1720 	fsparam_flag	("discard",		Opt_discard),
1721 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1722 	fsparam_u32	("init_itable",		Opt_init_itable),
1723 	fsparam_flag	("init_itable",		Opt_init_itable),
1724 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1725 #ifdef CONFIG_EXT4_DEBUG
1726 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1727 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1728 #endif
1729 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1730 	fsparam_flag	("test_dummy_encryption",
1731 						Opt_test_dummy_encryption),
1732 	fsparam_string	("test_dummy_encryption",
1733 						Opt_test_dummy_encryption),
1734 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1735 	fsparam_flag	("nombcache",		Opt_nombcache),
1736 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1737 	fsparam_flag	("prefetch_block_bitmaps",
1738 						Opt_removed),
1739 	fsparam_flag	("no_prefetch_block_bitmaps",
1740 						Opt_no_prefetch_block_bitmaps),
1741 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1742 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1743 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1744 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1745 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1746 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1747 	{}
1748 };
1749 
1750 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1751 
1752 static const char deprecated_msg[] =
1753 	"Mount option \"%s\" will be removed by %s\n"
1754 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1755 
1756 #define MOPT_SET	0x0001
1757 #define MOPT_CLEAR	0x0002
1758 #define MOPT_NOSUPPORT	0x0004
1759 #define MOPT_EXPLICIT	0x0008
1760 #ifdef CONFIG_QUOTA
1761 #define MOPT_Q		0
1762 #define MOPT_QFMT	0x0010
1763 #else
1764 #define MOPT_Q		MOPT_NOSUPPORT
1765 #define MOPT_QFMT	MOPT_NOSUPPORT
1766 #endif
1767 #define MOPT_NO_EXT2	0x0020
1768 #define MOPT_NO_EXT3	0x0040
1769 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1770 #define MOPT_SKIP	0x0080
1771 #define	MOPT_2		0x0100
1772 
1773 static const struct mount_opts {
1774 	int	token;
1775 	int	mount_opt;
1776 	int	flags;
1777 } ext4_mount_opts[] = {
1778 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1779 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1780 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1781 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1782 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1783 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1784 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1785 	 MOPT_EXT4_ONLY | MOPT_SET},
1786 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1787 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1788 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1789 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1790 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1791 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1792 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1793 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1794 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1795 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1796 	{Opt_commit, 0, MOPT_NO_EXT2},
1797 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1798 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1799 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1800 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1801 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1802 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1803 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1804 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1805 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1806 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1807 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1808 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1809 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1810 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1811 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1812 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1813 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1814 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1815 	{Opt_data, 0, MOPT_NO_EXT2},
1816 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1817 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1818 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1819 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1820 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1821 #else
1822 	{Opt_acl, 0, MOPT_NOSUPPORT},
1823 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1824 #endif
1825 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1826 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1827 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1828 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1829 							MOPT_SET | MOPT_Q},
1830 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1831 							MOPT_SET | MOPT_Q},
1832 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1833 							MOPT_SET | MOPT_Q},
1834 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1835 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1836 							MOPT_CLEAR | MOPT_Q},
1837 	{Opt_usrjquota, 0, MOPT_Q},
1838 	{Opt_grpjquota, 0, MOPT_Q},
1839 	{Opt_jqfmt, 0, MOPT_QFMT},
1840 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1841 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1842 	 MOPT_SET},
1843 #ifdef CONFIG_EXT4_DEBUG
1844 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1845 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1846 #endif
1847 	{Opt_err, 0, 0}
1848 };
1849 
1850 #if IS_ENABLED(CONFIG_UNICODE)
1851 static const struct ext4_sb_encodings {
1852 	__u16 magic;
1853 	char *name;
1854 	unsigned int version;
1855 } ext4_sb_encoding_map[] = {
1856 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1857 };
1858 
1859 static const struct ext4_sb_encodings *
1860 ext4_sb_read_encoding(const struct ext4_super_block *es)
1861 {
1862 	__u16 magic = le16_to_cpu(es->s_encoding);
1863 	int i;
1864 
1865 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1866 		if (magic == ext4_sb_encoding_map[i].magic)
1867 			return &ext4_sb_encoding_map[i];
1868 
1869 	return NULL;
1870 }
1871 #endif
1872 
1873 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1874 #define EXT4_SPEC_JQFMT				(1 <<  1)
1875 #define EXT4_SPEC_DATAJ				(1 <<  2)
1876 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1877 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1878 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1879 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1880 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1881 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1882 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1883 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1884 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1885 #define EXT4_SPEC_s_stripe			(1 << 13)
1886 #define EXT4_SPEC_s_resuid			(1 << 14)
1887 #define EXT4_SPEC_s_resgid			(1 << 15)
1888 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1889 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1890 #define EXT4_SPEC_s_sb_block			(1 << 18)
1891 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1892 
1893 struct ext4_fs_context {
1894 	char		*s_qf_names[EXT4_MAXQUOTAS];
1895 	struct fscrypt_dummy_policy dummy_enc_policy;
1896 	int		s_jquota_fmt;	/* Format of quota to use */
1897 #ifdef CONFIG_EXT4_DEBUG
1898 	int s_fc_debug_max_replay;
1899 #endif
1900 	unsigned short	qname_spec;
1901 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1902 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1903 	unsigned long	journal_devnum;
1904 	unsigned long	s_commit_interval;
1905 	unsigned long	s_stripe;
1906 	unsigned int	s_inode_readahead_blks;
1907 	unsigned int	s_want_extra_isize;
1908 	unsigned int	s_li_wait_mult;
1909 	unsigned int	s_max_dir_size_kb;
1910 	unsigned int	journal_ioprio;
1911 	unsigned int	vals_s_mount_opt;
1912 	unsigned int	mask_s_mount_opt;
1913 	unsigned int	vals_s_mount_opt2;
1914 	unsigned int	mask_s_mount_opt2;
1915 	unsigned long	vals_s_mount_flags;
1916 	unsigned long	mask_s_mount_flags;
1917 	unsigned int	opt_flags;	/* MOPT flags */
1918 	unsigned int	spec;
1919 	u32		s_max_batch_time;
1920 	u32		s_min_batch_time;
1921 	kuid_t		s_resuid;
1922 	kgid_t		s_resgid;
1923 	ext4_fsblk_t	s_sb_block;
1924 };
1925 
1926 static void ext4_fc_free(struct fs_context *fc)
1927 {
1928 	struct ext4_fs_context *ctx = fc->fs_private;
1929 	int i;
1930 
1931 	if (!ctx)
1932 		return;
1933 
1934 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1935 		kfree(ctx->s_qf_names[i]);
1936 
1937 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1938 	kfree(ctx);
1939 }
1940 
1941 int ext4_init_fs_context(struct fs_context *fc)
1942 {
1943 	struct ext4_fs_context *ctx;
1944 
1945 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1946 	if (!ctx)
1947 		return -ENOMEM;
1948 
1949 	fc->fs_private = ctx;
1950 	fc->ops = &ext4_context_ops;
1951 
1952 	return 0;
1953 }
1954 
1955 #ifdef CONFIG_QUOTA
1956 /*
1957  * Note the name of the specified quota file.
1958  */
1959 static int note_qf_name(struct fs_context *fc, int qtype,
1960 		       struct fs_parameter *param)
1961 {
1962 	struct ext4_fs_context *ctx = fc->fs_private;
1963 	char *qname;
1964 
1965 	if (param->size < 1) {
1966 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
1967 		return -EINVAL;
1968 	}
1969 	if (strchr(param->string, '/')) {
1970 		ext4_msg(NULL, KERN_ERR,
1971 			 "quotafile must be on filesystem root");
1972 		return -EINVAL;
1973 	}
1974 	if (ctx->s_qf_names[qtype]) {
1975 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
1976 			ext4_msg(NULL, KERN_ERR,
1977 				 "%s quota file already specified",
1978 				 QTYPE2NAME(qtype));
1979 			return -EINVAL;
1980 		}
1981 		return 0;
1982 	}
1983 
1984 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
1985 	if (!qname) {
1986 		ext4_msg(NULL, KERN_ERR,
1987 			 "Not enough memory for storing quotafile name");
1988 		return -ENOMEM;
1989 	}
1990 	ctx->s_qf_names[qtype] = qname;
1991 	ctx->qname_spec |= 1 << qtype;
1992 	ctx->spec |= EXT4_SPEC_JQUOTA;
1993 	return 0;
1994 }
1995 
1996 /*
1997  * Clear the name of the specified quota file.
1998  */
1999 static int unnote_qf_name(struct fs_context *fc, int qtype)
2000 {
2001 	struct ext4_fs_context *ctx = fc->fs_private;
2002 
2003 	if (ctx->s_qf_names[qtype])
2004 		kfree(ctx->s_qf_names[qtype]);
2005 
2006 	ctx->s_qf_names[qtype] = NULL;
2007 	ctx->qname_spec |= 1 << qtype;
2008 	ctx->spec |= EXT4_SPEC_JQUOTA;
2009 	return 0;
2010 }
2011 #endif
2012 
2013 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2014 					    struct ext4_fs_context *ctx)
2015 {
2016 	int err;
2017 
2018 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2019 		ext4_msg(NULL, KERN_WARNING,
2020 			 "test_dummy_encryption option not supported");
2021 		return -EINVAL;
2022 	}
2023 	err = fscrypt_parse_test_dummy_encryption(param,
2024 						  &ctx->dummy_enc_policy);
2025 	if (err == -EINVAL) {
2026 		ext4_msg(NULL, KERN_WARNING,
2027 			 "Value of option \"%s\" is unrecognized", param->key);
2028 	} else if (err == -EEXIST) {
2029 		ext4_msg(NULL, KERN_WARNING,
2030 			 "Conflicting test_dummy_encryption options");
2031 		return -EINVAL;
2032 	}
2033 	return err;
2034 }
2035 
2036 #define EXT4_SET_CTX(name)						\
2037 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2038 				  unsigned long flag)			\
2039 {									\
2040 	ctx->mask_s_##name |= flag;					\
2041 	ctx->vals_s_##name |= flag;					\
2042 }
2043 
2044 #define EXT4_CLEAR_CTX(name)						\
2045 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2046 				    unsigned long flag)			\
2047 {									\
2048 	ctx->mask_s_##name |= flag;					\
2049 	ctx->vals_s_##name &= ~flag;					\
2050 }
2051 
2052 #define EXT4_TEST_CTX(name)						\
2053 static inline unsigned long						\
2054 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2055 {									\
2056 	return (ctx->vals_s_##name & flag);				\
2057 }
2058 
2059 EXT4_SET_CTX(flags); /* set only */
2060 EXT4_SET_CTX(mount_opt);
2061 EXT4_CLEAR_CTX(mount_opt);
2062 EXT4_TEST_CTX(mount_opt);
2063 EXT4_SET_CTX(mount_opt2);
2064 EXT4_CLEAR_CTX(mount_opt2);
2065 EXT4_TEST_CTX(mount_opt2);
2066 
2067 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2068 {
2069 	set_bit(bit, &ctx->mask_s_mount_flags);
2070 	set_bit(bit, &ctx->vals_s_mount_flags);
2071 }
2072 
2073 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2074 {
2075 	struct ext4_fs_context *ctx = fc->fs_private;
2076 	struct fs_parse_result result;
2077 	const struct mount_opts *m;
2078 	int is_remount;
2079 	kuid_t uid;
2080 	kgid_t gid;
2081 	int token;
2082 
2083 	token = fs_parse(fc, ext4_param_specs, param, &result);
2084 	if (token < 0)
2085 		return token;
2086 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2087 
2088 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2089 		if (token == m->token)
2090 			break;
2091 
2092 	ctx->opt_flags |= m->flags;
2093 
2094 	if (m->flags & MOPT_EXPLICIT) {
2095 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2096 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2097 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2098 			ctx_set_mount_opt2(ctx,
2099 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2100 		} else
2101 			return -EINVAL;
2102 	}
2103 
2104 	if (m->flags & MOPT_NOSUPPORT) {
2105 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2106 			 param->key);
2107 		return 0;
2108 	}
2109 
2110 	switch (token) {
2111 #ifdef CONFIG_QUOTA
2112 	case Opt_usrjquota:
2113 		if (!*param->string)
2114 			return unnote_qf_name(fc, USRQUOTA);
2115 		else
2116 			return note_qf_name(fc, USRQUOTA, param);
2117 	case Opt_grpjquota:
2118 		if (!*param->string)
2119 			return unnote_qf_name(fc, GRPQUOTA);
2120 		else
2121 			return note_qf_name(fc, GRPQUOTA, param);
2122 #endif
2123 	case Opt_noacl:
2124 	case Opt_nouser_xattr:
2125 		ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "3.5");
2126 		break;
2127 	case Opt_sb:
2128 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2129 			ext4_msg(NULL, KERN_WARNING,
2130 				 "Ignoring %s option on remount", param->key);
2131 		} else {
2132 			ctx->s_sb_block = result.uint_32;
2133 			ctx->spec |= EXT4_SPEC_s_sb_block;
2134 		}
2135 		return 0;
2136 	case Opt_removed:
2137 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2138 			 param->key);
2139 		return 0;
2140 	case Opt_abort:
2141 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2142 		return 0;
2143 	case Opt_i_version:
2144 		ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "5.20");
2145 		ext4_msg(NULL, KERN_WARNING, "Use iversion instead\n");
2146 		ctx_set_flags(ctx, SB_I_VERSION);
2147 		return 0;
2148 	case Opt_inlinecrypt:
2149 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2150 		ctx_set_flags(ctx, SB_INLINECRYPT);
2151 #else
2152 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2153 #endif
2154 		return 0;
2155 	case Opt_errors:
2156 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2157 		ctx_set_mount_opt(ctx, result.uint_32);
2158 		return 0;
2159 #ifdef CONFIG_QUOTA
2160 	case Opt_jqfmt:
2161 		ctx->s_jquota_fmt = result.uint_32;
2162 		ctx->spec |= EXT4_SPEC_JQFMT;
2163 		return 0;
2164 #endif
2165 	case Opt_data:
2166 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2167 		ctx_set_mount_opt(ctx, result.uint_32);
2168 		ctx->spec |= EXT4_SPEC_DATAJ;
2169 		return 0;
2170 	case Opt_commit:
2171 		if (result.uint_32 == 0)
2172 			ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2173 		else if (result.uint_32 > INT_MAX / HZ) {
2174 			ext4_msg(NULL, KERN_ERR,
2175 				 "Invalid commit interval %d, "
2176 				 "must be smaller than %d",
2177 				 result.uint_32, INT_MAX / HZ);
2178 			return -EINVAL;
2179 		}
2180 		ctx->s_commit_interval = HZ * result.uint_32;
2181 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2182 		return 0;
2183 	case Opt_debug_want_extra_isize:
2184 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2185 			ext4_msg(NULL, KERN_ERR,
2186 				 "Invalid want_extra_isize %d", result.uint_32);
2187 			return -EINVAL;
2188 		}
2189 		ctx->s_want_extra_isize = result.uint_32;
2190 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2191 		return 0;
2192 	case Opt_max_batch_time:
2193 		ctx->s_max_batch_time = result.uint_32;
2194 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2195 		return 0;
2196 	case Opt_min_batch_time:
2197 		ctx->s_min_batch_time = result.uint_32;
2198 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2199 		return 0;
2200 	case Opt_inode_readahead_blks:
2201 		if (result.uint_32 &&
2202 		    (result.uint_32 > (1 << 30) ||
2203 		     !is_power_of_2(result.uint_32))) {
2204 			ext4_msg(NULL, KERN_ERR,
2205 				 "EXT4-fs: inode_readahead_blks must be "
2206 				 "0 or a power of 2 smaller than 2^31");
2207 			return -EINVAL;
2208 		}
2209 		ctx->s_inode_readahead_blks = result.uint_32;
2210 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2211 		return 0;
2212 	case Opt_init_itable:
2213 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2214 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2215 		if (param->type == fs_value_is_string)
2216 			ctx->s_li_wait_mult = result.uint_32;
2217 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2218 		return 0;
2219 	case Opt_max_dir_size_kb:
2220 		ctx->s_max_dir_size_kb = result.uint_32;
2221 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2222 		return 0;
2223 #ifdef CONFIG_EXT4_DEBUG
2224 	case Opt_fc_debug_max_replay:
2225 		ctx->s_fc_debug_max_replay = result.uint_32;
2226 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2227 		return 0;
2228 #endif
2229 	case Opt_stripe:
2230 		ctx->s_stripe = result.uint_32;
2231 		ctx->spec |= EXT4_SPEC_s_stripe;
2232 		return 0;
2233 	case Opt_resuid:
2234 		uid = make_kuid(current_user_ns(), result.uint_32);
2235 		if (!uid_valid(uid)) {
2236 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2237 				 result.uint_32);
2238 			return -EINVAL;
2239 		}
2240 		ctx->s_resuid = uid;
2241 		ctx->spec |= EXT4_SPEC_s_resuid;
2242 		return 0;
2243 	case Opt_resgid:
2244 		gid = make_kgid(current_user_ns(), result.uint_32);
2245 		if (!gid_valid(gid)) {
2246 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2247 				 result.uint_32);
2248 			return -EINVAL;
2249 		}
2250 		ctx->s_resgid = gid;
2251 		ctx->spec |= EXT4_SPEC_s_resgid;
2252 		return 0;
2253 	case Opt_journal_dev:
2254 		if (is_remount) {
2255 			ext4_msg(NULL, KERN_ERR,
2256 				 "Cannot specify journal on remount");
2257 			return -EINVAL;
2258 		}
2259 		ctx->journal_devnum = result.uint_32;
2260 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2261 		return 0;
2262 	case Opt_journal_path:
2263 	{
2264 		struct inode *journal_inode;
2265 		struct path path;
2266 		int error;
2267 
2268 		if (is_remount) {
2269 			ext4_msg(NULL, KERN_ERR,
2270 				 "Cannot specify journal on remount");
2271 			return -EINVAL;
2272 		}
2273 
2274 		error = fs_lookup_param(fc, param, 1, &path);
2275 		if (error) {
2276 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2277 				 "journal device path");
2278 			return -EINVAL;
2279 		}
2280 
2281 		journal_inode = d_inode(path.dentry);
2282 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2283 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2284 		path_put(&path);
2285 		return 0;
2286 	}
2287 	case Opt_journal_ioprio:
2288 		if (result.uint_32 > 7) {
2289 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2290 				 " (must be 0-7)");
2291 			return -EINVAL;
2292 		}
2293 		ctx->journal_ioprio =
2294 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2295 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2296 		return 0;
2297 	case Opt_test_dummy_encryption:
2298 		return ext4_parse_test_dummy_encryption(param, ctx);
2299 	case Opt_dax:
2300 	case Opt_dax_type:
2301 #ifdef CONFIG_FS_DAX
2302 	{
2303 		int type = (token == Opt_dax) ?
2304 			   Opt_dax : result.uint_32;
2305 
2306 		switch (type) {
2307 		case Opt_dax:
2308 		case Opt_dax_always:
2309 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2310 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2311 			break;
2312 		case Opt_dax_never:
2313 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2314 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2315 			break;
2316 		case Opt_dax_inode:
2317 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2318 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2319 			/* Strictly for printing options */
2320 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2321 			break;
2322 		}
2323 		return 0;
2324 	}
2325 #else
2326 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2327 		return -EINVAL;
2328 #endif
2329 	case Opt_data_err:
2330 		if (result.uint_32 == Opt_data_err_abort)
2331 			ctx_set_mount_opt(ctx, m->mount_opt);
2332 		else if (result.uint_32 == Opt_data_err_ignore)
2333 			ctx_clear_mount_opt(ctx, m->mount_opt);
2334 		return 0;
2335 	case Opt_mb_optimize_scan:
2336 		if (result.int_32 == 1) {
2337 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2338 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2339 		} else if (result.int_32 == 0) {
2340 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2341 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2342 		} else {
2343 			ext4_msg(NULL, KERN_WARNING,
2344 				 "mb_optimize_scan should be set to 0 or 1.");
2345 			return -EINVAL;
2346 		}
2347 		return 0;
2348 	}
2349 
2350 	/*
2351 	 * At this point we should only be getting options requiring MOPT_SET,
2352 	 * or MOPT_CLEAR. Anything else is a bug
2353 	 */
2354 	if (m->token == Opt_err) {
2355 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2356 			 param->key);
2357 		WARN_ON(1);
2358 		return -EINVAL;
2359 	}
2360 
2361 	else {
2362 		unsigned int set = 0;
2363 
2364 		if ((param->type == fs_value_is_flag) ||
2365 		    result.uint_32 > 0)
2366 			set = 1;
2367 
2368 		if (m->flags & MOPT_CLEAR)
2369 			set = !set;
2370 		else if (unlikely(!(m->flags & MOPT_SET))) {
2371 			ext4_msg(NULL, KERN_WARNING,
2372 				 "buggy handling of option %s",
2373 				 param->key);
2374 			WARN_ON(1);
2375 			return -EINVAL;
2376 		}
2377 		if (m->flags & MOPT_2) {
2378 			if (set != 0)
2379 				ctx_set_mount_opt2(ctx, m->mount_opt);
2380 			else
2381 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2382 		} else {
2383 			if (set != 0)
2384 				ctx_set_mount_opt(ctx, m->mount_opt);
2385 			else
2386 				ctx_clear_mount_opt(ctx, m->mount_opt);
2387 		}
2388 	}
2389 
2390 	return 0;
2391 }
2392 
2393 static int parse_options(struct fs_context *fc, char *options)
2394 {
2395 	struct fs_parameter param;
2396 	int ret;
2397 	char *key;
2398 
2399 	if (!options)
2400 		return 0;
2401 
2402 	while ((key = strsep(&options, ",")) != NULL) {
2403 		if (*key) {
2404 			size_t v_len = 0;
2405 			char *value = strchr(key, '=');
2406 
2407 			param.type = fs_value_is_flag;
2408 			param.string = NULL;
2409 
2410 			if (value) {
2411 				if (value == key)
2412 					continue;
2413 
2414 				*value++ = 0;
2415 				v_len = strlen(value);
2416 				param.string = kmemdup_nul(value, v_len,
2417 							   GFP_KERNEL);
2418 				if (!param.string)
2419 					return -ENOMEM;
2420 				param.type = fs_value_is_string;
2421 			}
2422 
2423 			param.key = key;
2424 			param.size = v_len;
2425 
2426 			ret = ext4_parse_param(fc, &param);
2427 			if (param.string)
2428 				kfree(param.string);
2429 			if (ret < 0)
2430 				return ret;
2431 		}
2432 	}
2433 
2434 	ret = ext4_validate_options(fc);
2435 	if (ret < 0)
2436 		return ret;
2437 
2438 	return 0;
2439 }
2440 
2441 static int parse_apply_sb_mount_options(struct super_block *sb,
2442 					struct ext4_fs_context *m_ctx)
2443 {
2444 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2445 	char *s_mount_opts = NULL;
2446 	struct ext4_fs_context *s_ctx = NULL;
2447 	struct fs_context *fc = NULL;
2448 	int ret = -ENOMEM;
2449 
2450 	if (!sbi->s_es->s_mount_opts[0])
2451 		return 0;
2452 
2453 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2454 				sizeof(sbi->s_es->s_mount_opts),
2455 				GFP_KERNEL);
2456 	if (!s_mount_opts)
2457 		return ret;
2458 
2459 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2460 	if (!fc)
2461 		goto out_free;
2462 
2463 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2464 	if (!s_ctx)
2465 		goto out_free;
2466 
2467 	fc->fs_private = s_ctx;
2468 	fc->s_fs_info = sbi;
2469 
2470 	ret = parse_options(fc, s_mount_opts);
2471 	if (ret < 0)
2472 		goto parse_failed;
2473 
2474 	ret = ext4_check_opt_consistency(fc, sb);
2475 	if (ret < 0) {
2476 parse_failed:
2477 		ext4_msg(sb, KERN_WARNING,
2478 			 "failed to parse options in superblock: %s",
2479 			 s_mount_opts);
2480 		ret = 0;
2481 		goto out_free;
2482 	}
2483 
2484 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2485 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2486 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2487 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2488 
2489 	ext4_apply_options(fc, sb);
2490 	ret = 0;
2491 
2492 out_free:
2493 	if (fc) {
2494 		ext4_fc_free(fc);
2495 		kfree(fc);
2496 	}
2497 	kfree(s_mount_opts);
2498 	return ret;
2499 }
2500 
2501 static void ext4_apply_quota_options(struct fs_context *fc,
2502 				     struct super_block *sb)
2503 {
2504 #ifdef CONFIG_QUOTA
2505 	bool quota_feature = ext4_has_feature_quota(sb);
2506 	struct ext4_fs_context *ctx = fc->fs_private;
2507 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2508 	char *qname;
2509 	int i;
2510 
2511 	if (quota_feature)
2512 		return;
2513 
2514 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2515 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2516 			if (!(ctx->qname_spec & (1 << i)))
2517 				continue;
2518 
2519 			qname = ctx->s_qf_names[i]; /* May be NULL */
2520 			if (qname)
2521 				set_opt(sb, QUOTA);
2522 			ctx->s_qf_names[i] = NULL;
2523 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2524 						lockdep_is_held(&sb->s_umount));
2525 			if (qname)
2526 				kfree_rcu(qname);
2527 		}
2528 	}
2529 
2530 	if (ctx->spec & EXT4_SPEC_JQFMT)
2531 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2532 #endif
2533 }
2534 
2535 /*
2536  * Check quota settings consistency.
2537  */
2538 static int ext4_check_quota_consistency(struct fs_context *fc,
2539 					struct super_block *sb)
2540 {
2541 #ifdef CONFIG_QUOTA
2542 	struct ext4_fs_context *ctx = fc->fs_private;
2543 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2544 	bool quota_feature = ext4_has_feature_quota(sb);
2545 	bool quota_loaded = sb_any_quota_loaded(sb);
2546 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2547 	int quota_flags, i;
2548 
2549 	/*
2550 	 * We do the test below only for project quotas. 'usrquota' and
2551 	 * 'grpquota' mount options are allowed even without quota feature
2552 	 * to support legacy quotas in quota files.
2553 	 */
2554 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2555 	    !ext4_has_feature_project(sb)) {
2556 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2557 			 "Cannot enable project quota enforcement.");
2558 		return -EINVAL;
2559 	}
2560 
2561 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2562 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2563 	if (quota_loaded &&
2564 	    ctx->mask_s_mount_opt & quota_flags &&
2565 	    !ctx_test_mount_opt(ctx, quota_flags))
2566 		goto err_quota_change;
2567 
2568 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2569 
2570 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2571 			if (!(ctx->qname_spec & (1 << i)))
2572 				continue;
2573 
2574 			if (quota_loaded &&
2575 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2576 				goto err_jquota_change;
2577 
2578 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2579 			    strcmp(get_qf_name(sb, sbi, i),
2580 				   ctx->s_qf_names[i]) != 0)
2581 				goto err_jquota_specified;
2582 		}
2583 
2584 		if (quota_feature) {
2585 			ext4_msg(NULL, KERN_INFO,
2586 				 "Journaled quota options ignored when "
2587 				 "QUOTA feature is enabled");
2588 			return 0;
2589 		}
2590 	}
2591 
2592 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2593 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2594 			goto err_jquota_change;
2595 		if (quota_feature) {
2596 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2597 				 "ignored when QUOTA feature is enabled");
2598 			return 0;
2599 		}
2600 	}
2601 
2602 	/* Make sure we don't mix old and new quota format */
2603 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2604 		       ctx->s_qf_names[USRQUOTA]);
2605 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2606 		       ctx->s_qf_names[GRPQUOTA]);
2607 
2608 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2609 		    test_opt(sb, USRQUOTA));
2610 
2611 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2612 		    test_opt(sb, GRPQUOTA));
2613 
2614 	if (usr_qf_name) {
2615 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2616 		usrquota = false;
2617 	}
2618 	if (grp_qf_name) {
2619 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2620 		grpquota = false;
2621 	}
2622 
2623 	if (usr_qf_name || grp_qf_name) {
2624 		if (usrquota || grpquota) {
2625 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2626 				 "format mixing");
2627 			return -EINVAL;
2628 		}
2629 
2630 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2631 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2632 				 "not specified");
2633 			return -EINVAL;
2634 		}
2635 	}
2636 
2637 	return 0;
2638 
2639 err_quota_change:
2640 	ext4_msg(NULL, KERN_ERR,
2641 		 "Cannot change quota options when quota turned on");
2642 	return -EINVAL;
2643 err_jquota_change:
2644 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2645 		 "options when quota turned on");
2646 	return -EINVAL;
2647 err_jquota_specified:
2648 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2649 		 QTYPE2NAME(i));
2650 	return -EINVAL;
2651 #else
2652 	return 0;
2653 #endif
2654 }
2655 
2656 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2657 					    struct super_block *sb)
2658 {
2659 	const struct ext4_fs_context *ctx = fc->fs_private;
2660 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2661 	int err;
2662 
2663 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2664 		return 0;
2665 
2666 	if (!ext4_has_feature_encrypt(sb)) {
2667 		ext4_msg(NULL, KERN_WARNING,
2668 			 "test_dummy_encryption requires encrypt feature");
2669 		return -EINVAL;
2670 	}
2671 	/*
2672 	 * This mount option is just for testing, and it's not worthwhile to
2673 	 * implement the extra complexity (e.g. RCU protection) that would be
2674 	 * needed to allow it to be set or changed during remount.  We do allow
2675 	 * it to be specified during remount, but only if there is no change.
2676 	 */
2677 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2678 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2679 						 &ctx->dummy_enc_policy))
2680 			return 0;
2681 		ext4_msg(NULL, KERN_WARNING,
2682 			 "Can't set or change test_dummy_encryption on remount");
2683 		return -EINVAL;
2684 	}
2685 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2686 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2687 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2688 						 &ctx->dummy_enc_policy))
2689 			return 0;
2690 		ext4_msg(NULL, KERN_WARNING,
2691 			 "Conflicting test_dummy_encryption options");
2692 		return -EINVAL;
2693 	}
2694 	/*
2695 	 * fscrypt_add_test_dummy_key() technically changes the super_block, so
2696 	 * technically it should be delayed until ext4_apply_options() like the
2697 	 * other changes.  But since we never get here for remounts (see above),
2698 	 * and this is the last chance to report errors, we do it here.
2699 	 */
2700 	err = fscrypt_add_test_dummy_key(sb, &ctx->dummy_enc_policy);
2701 	if (err)
2702 		ext4_msg(NULL, KERN_WARNING,
2703 			 "Error adding test dummy encryption key [%d]", err);
2704 	return err;
2705 }
2706 
2707 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2708 					     struct super_block *sb)
2709 {
2710 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2711 	    /* if already set, it was already verified to be the same */
2712 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2713 		return;
2714 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2715 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2716 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2717 }
2718 
2719 static int ext4_check_opt_consistency(struct fs_context *fc,
2720 				      struct super_block *sb)
2721 {
2722 	struct ext4_fs_context *ctx = fc->fs_private;
2723 	struct ext4_sb_info *sbi = fc->s_fs_info;
2724 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2725 	int err;
2726 
2727 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2728 		ext4_msg(NULL, KERN_ERR,
2729 			 "Mount option(s) incompatible with ext2");
2730 		return -EINVAL;
2731 	}
2732 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2733 		ext4_msg(NULL, KERN_ERR,
2734 			 "Mount option(s) incompatible with ext3");
2735 		return -EINVAL;
2736 	}
2737 
2738 	if (ctx->s_want_extra_isize >
2739 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2740 		ext4_msg(NULL, KERN_ERR,
2741 			 "Invalid want_extra_isize %d",
2742 			 ctx->s_want_extra_isize);
2743 		return -EINVAL;
2744 	}
2745 
2746 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2747 		int blocksize =
2748 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2749 		if (blocksize < PAGE_SIZE)
2750 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2751 				 "experimental mount option 'dioread_nolock' "
2752 				 "for blocksize < PAGE_SIZE");
2753 	}
2754 
2755 	err = ext4_check_test_dummy_encryption(fc, sb);
2756 	if (err)
2757 		return err;
2758 
2759 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2760 		if (!sbi->s_journal) {
2761 			ext4_msg(NULL, KERN_WARNING,
2762 				 "Remounting file system with no journal "
2763 				 "so ignoring journalled data option");
2764 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2765 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2766 			   test_opt(sb, DATA_FLAGS)) {
2767 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2768 				 "on remount");
2769 			return -EINVAL;
2770 		}
2771 	}
2772 
2773 	if (is_remount) {
2774 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2775 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2776 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2777 				 "both data=journal and dax");
2778 			return -EINVAL;
2779 		}
2780 
2781 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2782 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2783 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2784 fail_dax_change_remount:
2785 			ext4_msg(NULL, KERN_ERR, "can't change "
2786 				 "dax mount option while remounting");
2787 			return -EINVAL;
2788 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2789 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2790 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2791 			goto fail_dax_change_remount;
2792 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2793 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2794 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2795 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2796 			goto fail_dax_change_remount;
2797 		}
2798 	}
2799 
2800 	return ext4_check_quota_consistency(fc, sb);
2801 }
2802 
2803 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2804 {
2805 	struct ext4_fs_context *ctx = fc->fs_private;
2806 	struct ext4_sb_info *sbi = fc->s_fs_info;
2807 
2808 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2809 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2810 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2811 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2812 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2813 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2814 	sb->s_flags &= ~ctx->mask_s_flags;
2815 	sb->s_flags |= ctx->vals_s_flags;
2816 
2817 	/*
2818 	 * i_version differs from common mount option iversion so we have
2819 	 * to let vfs know that it was set, otherwise it would get cleared
2820 	 * on remount
2821 	 */
2822 	if (ctx->mask_s_flags & SB_I_VERSION)
2823 		fc->sb_flags |= SB_I_VERSION;
2824 
2825 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2826 	APPLY(s_commit_interval);
2827 	APPLY(s_stripe);
2828 	APPLY(s_max_batch_time);
2829 	APPLY(s_min_batch_time);
2830 	APPLY(s_want_extra_isize);
2831 	APPLY(s_inode_readahead_blks);
2832 	APPLY(s_max_dir_size_kb);
2833 	APPLY(s_li_wait_mult);
2834 	APPLY(s_resgid);
2835 	APPLY(s_resuid);
2836 
2837 #ifdef CONFIG_EXT4_DEBUG
2838 	APPLY(s_fc_debug_max_replay);
2839 #endif
2840 
2841 	ext4_apply_quota_options(fc, sb);
2842 	ext4_apply_test_dummy_encryption(ctx, sb);
2843 }
2844 
2845 
2846 static int ext4_validate_options(struct fs_context *fc)
2847 {
2848 #ifdef CONFIG_QUOTA
2849 	struct ext4_fs_context *ctx = fc->fs_private;
2850 	char *usr_qf_name, *grp_qf_name;
2851 
2852 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2853 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2854 
2855 	if (usr_qf_name || grp_qf_name) {
2856 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2857 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2858 
2859 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2860 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2861 
2862 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2863 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2864 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2865 				 "format mixing");
2866 			return -EINVAL;
2867 		}
2868 	}
2869 #endif
2870 	return 1;
2871 }
2872 
2873 static inline void ext4_show_quota_options(struct seq_file *seq,
2874 					   struct super_block *sb)
2875 {
2876 #if defined(CONFIG_QUOTA)
2877 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2878 	char *usr_qf_name, *grp_qf_name;
2879 
2880 	if (sbi->s_jquota_fmt) {
2881 		char *fmtname = "";
2882 
2883 		switch (sbi->s_jquota_fmt) {
2884 		case QFMT_VFS_OLD:
2885 			fmtname = "vfsold";
2886 			break;
2887 		case QFMT_VFS_V0:
2888 			fmtname = "vfsv0";
2889 			break;
2890 		case QFMT_VFS_V1:
2891 			fmtname = "vfsv1";
2892 			break;
2893 		}
2894 		seq_printf(seq, ",jqfmt=%s", fmtname);
2895 	}
2896 
2897 	rcu_read_lock();
2898 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2899 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2900 	if (usr_qf_name)
2901 		seq_show_option(seq, "usrjquota", usr_qf_name);
2902 	if (grp_qf_name)
2903 		seq_show_option(seq, "grpjquota", grp_qf_name);
2904 	rcu_read_unlock();
2905 #endif
2906 }
2907 
2908 static const char *token2str(int token)
2909 {
2910 	const struct fs_parameter_spec *spec;
2911 
2912 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2913 		if (spec->opt == token && !spec->type)
2914 			break;
2915 	return spec->name;
2916 }
2917 
2918 /*
2919  * Show an option if
2920  *  - it's set to a non-default value OR
2921  *  - if the per-sb default is different from the global default
2922  */
2923 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2924 			      int nodefs)
2925 {
2926 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2927 	struct ext4_super_block *es = sbi->s_es;
2928 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2929 	const struct mount_opts *m;
2930 	char sep = nodefs ? '\n' : ',';
2931 
2932 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2933 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2934 
2935 	if (sbi->s_sb_block != 1)
2936 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2937 
2938 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2939 		int want_set = m->flags & MOPT_SET;
2940 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2941 		    m->flags & MOPT_SKIP)
2942 			continue;
2943 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2944 			continue; /* skip if same as the default */
2945 		if ((want_set &&
2946 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2947 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2948 			continue; /* select Opt_noFoo vs Opt_Foo */
2949 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2950 	}
2951 
2952 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2953 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2954 		SEQ_OPTS_PRINT("resuid=%u",
2955 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2956 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2957 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2958 		SEQ_OPTS_PRINT("resgid=%u",
2959 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2960 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2961 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2962 		SEQ_OPTS_PUTS("errors=remount-ro");
2963 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2964 		SEQ_OPTS_PUTS("errors=continue");
2965 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2966 		SEQ_OPTS_PUTS("errors=panic");
2967 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2968 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2969 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2970 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2971 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2972 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2973 	if (sb->s_flags & SB_I_VERSION)
2974 		SEQ_OPTS_PUTS("i_version");
2975 	if (nodefs || sbi->s_stripe)
2976 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2977 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2978 			(sbi->s_mount_opt ^ def_mount_opt)) {
2979 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2980 			SEQ_OPTS_PUTS("data=journal");
2981 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2982 			SEQ_OPTS_PUTS("data=ordered");
2983 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2984 			SEQ_OPTS_PUTS("data=writeback");
2985 	}
2986 	if (nodefs ||
2987 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2988 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2989 			       sbi->s_inode_readahead_blks);
2990 
2991 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2992 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2993 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2994 	if (nodefs || sbi->s_max_dir_size_kb)
2995 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2996 	if (test_opt(sb, DATA_ERR_ABORT))
2997 		SEQ_OPTS_PUTS("data_err=abort");
2998 
2999 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3000 
3001 	if (sb->s_flags & SB_INLINECRYPT)
3002 		SEQ_OPTS_PUTS("inlinecrypt");
3003 
3004 	if (test_opt(sb, DAX_ALWAYS)) {
3005 		if (IS_EXT2_SB(sb))
3006 			SEQ_OPTS_PUTS("dax");
3007 		else
3008 			SEQ_OPTS_PUTS("dax=always");
3009 	} else if (test_opt2(sb, DAX_NEVER)) {
3010 		SEQ_OPTS_PUTS("dax=never");
3011 	} else if (test_opt2(sb, DAX_INODE)) {
3012 		SEQ_OPTS_PUTS("dax=inode");
3013 	}
3014 	ext4_show_quota_options(seq, sb);
3015 	return 0;
3016 }
3017 
3018 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3019 {
3020 	return _ext4_show_options(seq, root->d_sb, 0);
3021 }
3022 
3023 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3024 {
3025 	struct super_block *sb = seq->private;
3026 	int rc;
3027 
3028 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3029 	rc = _ext4_show_options(seq, sb, 1);
3030 	seq_puts(seq, "\n");
3031 	return rc;
3032 }
3033 
3034 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3035 			    int read_only)
3036 {
3037 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3038 	int err = 0;
3039 
3040 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3041 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3042 			 "forcing read-only mode");
3043 		err = -EROFS;
3044 		goto done;
3045 	}
3046 	if (read_only)
3047 		goto done;
3048 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3049 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3050 			 "running e2fsck is recommended");
3051 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3052 		ext4_msg(sb, KERN_WARNING,
3053 			 "warning: mounting fs with errors, "
3054 			 "running e2fsck is recommended");
3055 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3056 		 le16_to_cpu(es->s_mnt_count) >=
3057 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3058 		ext4_msg(sb, KERN_WARNING,
3059 			 "warning: maximal mount count reached, "
3060 			 "running e2fsck is recommended");
3061 	else if (le32_to_cpu(es->s_checkinterval) &&
3062 		 (ext4_get_tstamp(es, s_lastcheck) +
3063 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3064 		ext4_msg(sb, KERN_WARNING,
3065 			 "warning: checktime reached, "
3066 			 "running e2fsck is recommended");
3067 	if (!sbi->s_journal)
3068 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3069 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3070 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3071 	le16_add_cpu(&es->s_mnt_count, 1);
3072 	ext4_update_tstamp(es, s_mtime);
3073 	if (sbi->s_journal) {
3074 		ext4_set_feature_journal_needs_recovery(sb);
3075 		if (ext4_has_feature_orphan_file(sb))
3076 			ext4_set_feature_orphan_present(sb);
3077 	}
3078 
3079 	err = ext4_commit_super(sb);
3080 done:
3081 	if (test_opt(sb, DEBUG))
3082 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3083 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3084 			sb->s_blocksize,
3085 			sbi->s_groups_count,
3086 			EXT4_BLOCKS_PER_GROUP(sb),
3087 			EXT4_INODES_PER_GROUP(sb),
3088 			sbi->s_mount_opt, sbi->s_mount_opt2);
3089 	return err;
3090 }
3091 
3092 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3093 {
3094 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3095 	struct flex_groups **old_groups, **new_groups;
3096 	int size, i, j;
3097 
3098 	if (!sbi->s_log_groups_per_flex)
3099 		return 0;
3100 
3101 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3102 	if (size <= sbi->s_flex_groups_allocated)
3103 		return 0;
3104 
3105 	new_groups = kvzalloc(roundup_pow_of_two(size *
3106 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3107 	if (!new_groups) {
3108 		ext4_msg(sb, KERN_ERR,
3109 			 "not enough memory for %d flex group pointers", size);
3110 		return -ENOMEM;
3111 	}
3112 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3113 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3114 					 sizeof(struct flex_groups)),
3115 					 GFP_KERNEL);
3116 		if (!new_groups[i]) {
3117 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3118 				kvfree(new_groups[j]);
3119 			kvfree(new_groups);
3120 			ext4_msg(sb, KERN_ERR,
3121 				 "not enough memory for %d flex groups", size);
3122 			return -ENOMEM;
3123 		}
3124 	}
3125 	rcu_read_lock();
3126 	old_groups = rcu_dereference(sbi->s_flex_groups);
3127 	if (old_groups)
3128 		memcpy(new_groups, old_groups,
3129 		       (sbi->s_flex_groups_allocated *
3130 			sizeof(struct flex_groups *)));
3131 	rcu_read_unlock();
3132 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3133 	sbi->s_flex_groups_allocated = size;
3134 	if (old_groups)
3135 		ext4_kvfree_array_rcu(old_groups);
3136 	return 0;
3137 }
3138 
3139 static int ext4_fill_flex_info(struct super_block *sb)
3140 {
3141 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3142 	struct ext4_group_desc *gdp = NULL;
3143 	struct flex_groups *fg;
3144 	ext4_group_t flex_group;
3145 	int i, err;
3146 
3147 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3148 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3149 		sbi->s_log_groups_per_flex = 0;
3150 		return 1;
3151 	}
3152 
3153 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3154 	if (err)
3155 		goto failed;
3156 
3157 	for (i = 0; i < sbi->s_groups_count; i++) {
3158 		gdp = ext4_get_group_desc(sb, i, NULL);
3159 
3160 		flex_group = ext4_flex_group(sbi, i);
3161 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3162 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3163 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3164 			     &fg->free_clusters);
3165 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3166 	}
3167 
3168 	return 1;
3169 failed:
3170 	return 0;
3171 }
3172 
3173 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3174 				   struct ext4_group_desc *gdp)
3175 {
3176 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3177 	__u16 crc = 0;
3178 	__le32 le_group = cpu_to_le32(block_group);
3179 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3180 
3181 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3182 		/* Use new metadata_csum algorithm */
3183 		__u32 csum32;
3184 		__u16 dummy_csum = 0;
3185 
3186 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3187 				     sizeof(le_group));
3188 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3189 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3190 				     sizeof(dummy_csum));
3191 		offset += sizeof(dummy_csum);
3192 		if (offset < sbi->s_desc_size)
3193 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3194 					     sbi->s_desc_size - offset);
3195 
3196 		crc = csum32 & 0xFFFF;
3197 		goto out;
3198 	}
3199 
3200 	/* old crc16 code */
3201 	if (!ext4_has_feature_gdt_csum(sb))
3202 		return 0;
3203 
3204 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3205 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3206 	crc = crc16(crc, (__u8 *)gdp, offset);
3207 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3208 	/* for checksum of struct ext4_group_desc do the rest...*/
3209 	if (ext4_has_feature_64bit(sb) &&
3210 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3211 		crc = crc16(crc, (__u8 *)gdp + offset,
3212 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3213 				offset);
3214 
3215 out:
3216 	return cpu_to_le16(crc);
3217 }
3218 
3219 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3220 				struct ext4_group_desc *gdp)
3221 {
3222 	if (ext4_has_group_desc_csum(sb) &&
3223 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3224 		return 0;
3225 
3226 	return 1;
3227 }
3228 
3229 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3230 			      struct ext4_group_desc *gdp)
3231 {
3232 	if (!ext4_has_group_desc_csum(sb))
3233 		return;
3234 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3235 }
3236 
3237 /* Called at mount-time, super-block is locked */
3238 static int ext4_check_descriptors(struct super_block *sb,
3239 				  ext4_fsblk_t sb_block,
3240 				  ext4_group_t *first_not_zeroed)
3241 {
3242 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3243 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3244 	ext4_fsblk_t last_block;
3245 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3246 	ext4_fsblk_t block_bitmap;
3247 	ext4_fsblk_t inode_bitmap;
3248 	ext4_fsblk_t inode_table;
3249 	int flexbg_flag = 0;
3250 	ext4_group_t i, grp = sbi->s_groups_count;
3251 
3252 	if (ext4_has_feature_flex_bg(sb))
3253 		flexbg_flag = 1;
3254 
3255 	ext4_debug("Checking group descriptors");
3256 
3257 	for (i = 0; i < sbi->s_groups_count; i++) {
3258 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3259 
3260 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3261 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3262 		else
3263 			last_block = first_block +
3264 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3265 
3266 		if ((grp == sbi->s_groups_count) &&
3267 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3268 			grp = i;
3269 
3270 		block_bitmap = ext4_block_bitmap(sb, gdp);
3271 		if (block_bitmap == sb_block) {
3272 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3273 				 "Block bitmap for group %u overlaps "
3274 				 "superblock", i);
3275 			if (!sb_rdonly(sb))
3276 				return 0;
3277 		}
3278 		if (block_bitmap >= sb_block + 1 &&
3279 		    block_bitmap <= last_bg_block) {
3280 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3281 				 "Block bitmap for group %u overlaps "
3282 				 "block group descriptors", i);
3283 			if (!sb_rdonly(sb))
3284 				return 0;
3285 		}
3286 		if (block_bitmap < first_block || block_bitmap > last_block) {
3287 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3288 			       "Block bitmap for group %u not in group "
3289 			       "(block %llu)!", i, block_bitmap);
3290 			return 0;
3291 		}
3292 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3293 		if (inode_bitmap == sb_block) {
3294 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3295 				 "Inode bitmap for group %u overlaps "
3296 				 "superblock", i);
3297 			if (!sb_rdonly(sb))
3298 				return 0;
3299 		}
3300 		if (inode_bitmap >= sb_block + 1 &&
3301 		    inode_bitmap <= last_bg_block) {
3302 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3303 				 "Inode bitmap for group %u overlaps "
3304 				 "block group descriptors", i);
3305 			if (!sb_rdonly(sb))
3306 				return 0;
3307 		}
3308 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3309 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3310 			       "Inode bitmap for group %u not in group "
3311 			       "(block %llu)!", i, inode_bitmap);
3312 			return 0;
3313 		}
3314 		inode_table = ext4_inode_table(sb, gdp);
3315 		if (inode_table == sb_block) {
3316 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3317 				 "Inode table for group %u overlaps "
3318 				 "superblock", i);
3319 			if (!sb_rdonly(sb))
3320 				return 0;
3321 		}
3322 		if (inode_table >= sb_block + 1 &&
3323 		    inode_table <= last_bg_block) {
3324 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3325 				 "Inode table for group %u overlaps "
3326 				 "block group descriptors", i);
3327 			if (!sb_rdonly(sb))
3328 				return 0;
3329 		}
3330 		if (inode_table < first_block ||
3331 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3332 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3333 			       "Inode table for group %u not in group "
3334 			       "(block %llu)!", i, inode_table);
3335 			return 0;
3336 		}
3337 		ext4_lock_group(sb, i);
3338 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3339 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3340 				 "Checksum for group %u failed (%u!=%u)",
3341 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3342 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3343 			if (!sb_rdonly(sb)) {
3344 				ext4_unlock_group(sb, i);
3345 				return 0;
3346 			}
3347 		}
3348 		ext4_unlock_group(sb, i);
3349 		if (!flexbg_flag)
3350 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3351 	}
3352 	if (NULL != first_not_zeroed)
3353 		*first_not_zeroed = grp;
3354 	return 1;
3355 }
3356 
3357 /*
3358  * Maximal extent format file size.
3359  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3360  * extent format containers, within a sector_t, and within i_blocks
3361  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3362  * so that won't be a limiting factor.
3363  *
3364  * However there is other limiting factor. We do store extents in the form
3365  * of starting block and length, hence the resulting length of the extent
3366  * covering maximum file size must fit into on-disk format containers as
3367  * well. Given that length is always by 1 unit bigger than max unit (because
3368  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3369  *
3370  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3371  */
3372 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3373 {
3374 	loff_t res;
3375 	loff_t upper_limit = MAX_LFS_FILESIZE;
3376 
3377 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3378 
3379 	if (!has_huge_files) {
3380 		upper_limit = (1LL << 32) - 1;
3381 
3382 		/* total blocks in file system block size */
3383 		upper_limit >>= (blkbits - 9);
3384 		upper_limit <<= blkbits;
3385 	}
3386 
3387 	/*
3388 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3389 	 * by one fs block, so ee_len can cover the extent of maximum file
3390 	 * size
3391 	 */
3392 	res = (1LL << 32) - 1;
3393 	res <<= blkbits;
3394 
3395 	/* Sanity check against vm- & vfs- imposed limits */
3396 	if (res > upper_limit)
3397 		res = upper_limit;
3398 
3399 	return res;
3400 }
3401 
3402 /*
3403  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3404  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3405  * We need to be 1 filesystem block less than the 2^48 sector limit.
3406  */
3407 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3408 {
3409 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3410 	int meta_blocks;
3411 	unsigned int ppb = 1 << (bits - 2);
3412 
3413 	/*
3414 	 * This is calculated to be the largest file size for a dense, block
3415 	 * mapped file such that the file's total number of 512-byte sectors,
3416 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3417 	 *
3418 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3419 	 * number of 512-byte sectors of the file.
3420 	 */
3421 	if (!has_huge_files) {
3422 		/*
3423 		 * !has_huge_files or implies that the inode i_block field
3424 		 * represents total file blocks in 2^32 512-byte sectors ==
3425 		 * size of vfs inode i_blocks * 8
3426 		 */
3427 		upper_limit = (1LL << 32) - 1;
3428 
3429 		/* total blocks in file system block size */
3430 		upper_limit >>= (bits - 9);
3431 
3432 	} else {
3433 		/*
3434 		 * We use 48 bit ext4_inode i_blocks
3435 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3436 		 * represent total number of blocks in
3437 		 * file system block size
3438 		 */
3439 		upper_limit = (1LL << 48) - 1;
3440 
3441 	}
3442 
3443 	/* Compute how many blocks we can address by block tree */
3444 	res += ppb;
3445 	res += ppb * ppb;
3446 	res += ((loff_t)ppb) * ppb * ppb;
3447 	/* Compute how many metadata blocks are needed */
3448 	meta_blocks = 1;
3449 	meta_blocks += 1 + ppb;
3450 	meta_blocks += 1 + ppb + ppb * ppb;
3451 	/* Does block tree limit file size? */
3452 	if (res + meta_blocks <= upper_limit)
3453 		goto check_lfs;
3454 
3455 	res = upper_limit;
3456 	/* How many metadata blocks are needed for addressing upper_limit? */
3457 	upper_limit -= EXT4_NDIR_BLOCKS;
3458 	/* indirect blocks */
3459 	meta_blocks = 1;
3460 	upper_limit -= ppb;
3461 	/* double indirect blocks */
3462 	if (upper_limit < ppb * ppb) {
3463 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3464 		res -= meta_blocks;
3465 		goto check_lfs;
3466 	}
3467 	meta_blocks += 1 + ppb;
3468 	upper_limit -= ppb * ppb;
3469 	/* tripple indirect blocks for the rest */
3470 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3471 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3472 	res -= meta_blocks;
3473 check_lfs:
3474 	res <<= bits;
3475 	if (res > MAX_LFS_FILESIZE)
3476 		res = MAX_LFS_FILESIZE;
3477 
3478 	return res;
3479 }
3480 
3481 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3482 				   ext4_fsblk_t logical_sb_block, int nr)
3483 {
3484 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3485 	ext4_group_t bg, first_meta_bg;
3486 	int has_super = 0;
3487 
3488 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3489 
3490 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3491 		return logical_sb_block + nr + 1;
3492 	bg = sbi->s_desc_per_block * nr;
3493 	if (ext4_bg_has_super(sb, bg))
3494 		has_super = 1;
3495 
3496 	/*
3497 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3498 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3499 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3500 	 * compensate.
3501 	 */
3502 	if (sb->s_blocksize == 1024 && nr == 0 &&
3503 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3504 		has_super++;
3505 
3506 	return (has_super + ext4_group_first_block_no(sb, bg));
3507 }
3508 
3509 /**
3510  * ext4_get_stripe_size: Get the stripe size.
3511  * @sbi: In memory super block info
3512  *
3513  * If we have specified it via mount option, then
3514  * use the mount option value. If the value specified at mount time is
3515  * greater than the blocks per group use the super block value.
3516  * If the super block value is greater than blocks per group return 0.
3517  * Allocator needs it be less than blocks per group.
3518  *
3519  */
3520 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3521 {
3522 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3523 	unsigned long stripe_width =
3524 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3525 	int ret;
3526 
3527 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3528 		ret = sbi->s_stripe;
3529 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3530 		ret = stripe_width;
3531 	else if (stride && stride <= sbi->s_blocks_per_group)
3532 		ret = stride;
3533 	else
3534 		ret = 0;
3535 
3536 	/*
3537 	 * If the stripe width is 1, this makes no sense and
3538 	 * we set it to 0 to turn off stripe handling code.
3539 	 */
3540 	if (ret <= 1)
3541 		ret = 0;
3542 
3543 	return ret;
3544 }
3545 
3546 /*
3547  * Check whether this filesystem can be mounted based on
3548  * the features present and the RDONLY/RDWR mount requested.
3549  * Returns 1 if this filesystem can be mounted as requested,
3550  * 0 if it cannot be.
3551  */
3552 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3553 {
3554 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3555 		ext4_msg(sb, KERN_ERR,
3556 			"Couldn't mount because of "
3557 			"unsupported optional features (%x)",
3558 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3559 			~EXT4_FEATURE_INCOMPAT_SUPP));
3560 		return 0;
3561 	}
3562 
3563 #if !IS_ENABLED(CONFIG_UNICODE)
3564 	if (ext4_has_feature_casefold(sb)) {
3565 		ext4_msg(sb, KERN_ERR,
3566 			 "Filesystem with casefold feature cannot be "
3567 			 "mounted without CONFIG_UNICODE");
3568 		return 0;
3569 	}
3570 #endif
3571 
3572 	if (readonly)
3573 		return 1;
3574 
3575 	if (ext4_has_feature_readonly(sb)) {
3576 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3577 		sb->s_flags |= SB_RDONLY;
3578 		return 1;
3579 	}
3580 
3581 	/* Check that feature set is OK for a read-write mount */
3582 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3583 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3584 			 "unsupported optional features (%x)",
3585 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3586 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3587 		return 0;
3588 	}
3589 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3590 		ext4_msg(sb, KERN_ERR,
3591 			 "Can't support bigalloc feature without "
3592 			 "extents feature\n");
3593 		return 0;
3594 	}
3595 
3596 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3597 	if (!readonly && (ext4_has_feature_quota(sb) ||
3598 			  ext4_has_feature_project(sb))) {
3599 		ext4_msg(sb, KERN_ERR,
3600 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3601 		return 0;
3602 	}
3603 #endif  /* CONFIG_QUOTA */
3604 	return 1;
3605 }
3606 
3607 /*
3608  * This function is called once a day if we have errors logged
3609  * on the file system
3610  */
3611 static void print_daily_error_info(struct timer_list *t)
3612 {
3613 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3614 	struct super_block *sb = sbi->s_sb;
3615 	struct ext4_super_block *es = sbi->s_es;
3616 
3617 	if (es->s_error_count)
3618 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3619 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3620 			 le32_to_cpu(es->s_error_count));
3621 	if (es->s_first_error_time) {
3622 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3623 		       sb->s_id,
3624 		       ext4_get_tstamp(es, s_first_error_time),
3625 		       (int) sizeof(es->s_first_error_func),
3626 		       es->s_first_error_func,
3627 		       le32_to_cpu(es->s_first_error_line));
3628 		if (es->s_first_error_ino)
3629 			printk(KERN_CONT ": inode %u",
3630 			       le32_to_cpu(es->s_first_error_ino));
3631 		if (es->s_first_error_block)
3632 			printk(KERN_CONT ": block %llu", (unsigned long long)
3633 			       le64_to_cpu(es->s_first_error_block));
3634 		printk(KERN_CONT "\n");
3635 	}
3636 	if (es->s_last_error_time) {
3637 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3638 		       sb->s_id,
3639 		       ext4_get_tstamp(es, s_last_error_time),
3640 		       (int) sizeof(es->s_last_error_func),
3641 		       es->s_last_error_func,
3642 		       le32_to_cpu(es->s_last_error_line));
3643 		if (es->s_last_error_ino)
3644 			printk(KERN_CONT ": inode %u",
3645 			       le32_to_cpu(es->s_last_error_ino));
3646 		if (es->s_last_error_block)
3647 			printk(KERN_CONT ": block %llu", (unsigned long long)
3648 			       le64_to_cpu(es->s_last_error_block));
3649 		printk(KERN_CONT "\n");
3650 	}
3651 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3652 }
3653 
3654 /* Find next suitable group and run ext4_init_inode_table */
3655 static int ext4_run_li_request(struct ext4_li_request *elr)
3656 {
3657 	struct ext4_group_desc *gdp = NULL;
3658 	struct super_block *sb = elr->lr_super;
3659 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3660 	ext4_group_t group = elr->lr_next_group;
3661 	unsigned int prefetch_ios = 0;
3662 	int ret = 0;
3663 	u64 start_time;
3664 
3665 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3666 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3667 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3668 		if (prefetch_ios)
3669 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3670 					      prefetch_ios);
3671 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3672 					    prefetch_ios);
3673 		if (group >= elr->lr_next_group) {
3674 			ret = 1;
3675 			if (elr->lr_first_not_zeroed != ngroups &&
3676 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3677 				elr->lr_next_group = elr->lr_first_not_zeroed;
3678 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3679 				ret = 0;
3680 			}
3681 		}
3682 		return ret;
3683 	}
3684 
3685 	for (; group < ngroups; group++) {
3686 		gdp = ext4_get_group_desc(sb, group, NULL);
3687 		if (!gdp) {
3688 			ret = 1;
3689 			break;
3690 		}
3691 
3692 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3693 			break;
3694 	}
3695 
3696 	if (group >= ngroups)
3697 		ret = 1;
3698 
3699 	if (!ret) {
3700 		start_time = ktime_get_real_ns();
3701 		ret = ext4_init_inode_table(sb, group,
3702 					    elr->lr_timeout ? 0 : 1);
3703 		trace_ext4_lazy_itable_init(sb, group);
3704 		if (elr->lr_timeout == 0) {
3705 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3706 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3707 		}
3708 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3709 		elr->lr_next_group = group + 1;
3710 	}
3711 	return ret;
3712 }
3713 
3714 /*
3715  * Remove lr_request from the list_request and free the
3716  * request structure. Should be called with li_list_mtx held
3717  */
3718 static void ext4_remove_li_request(struct ext4_li_request *elr)
3719 {
3720 	if (!elr)
3721 		return;
3722 
3723 	list_del(&elr->lr_request);
3724 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3725 	kfree(elr);
3726 }
3727 
3728 static void ext4_unregister_li_request(struct super_block *sb)
3729 {
3730 	mutex_lock(&ext4_li_mtx);
3731 	if (!ext4_li_info) {
3732 		mutex_unlock(&ext4_li_mtx);
3733 		return;
3734 	}
3735 
3736 	mutex_lock(&ext4_li_info->li_list_mtx);
3737 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3738 	mutex_unlock(&ext4_li_info->li_list_mtx);
3739 	mutex_unlock(&ext4_li_mtx);
3740 }
3741 
3742 static struct task_struct *ext4_lazyinit_task;
3743 
3744 /*
3745  * This is the function where ext4lazyinit thread lives. It walks
3746  * through the request list searching for next scheduled filesystem.
3747  * When such a fs is found, run the lazy initialization request
3748  * (ext4_rn_li_request) and keep track of the time spend in this
3749  * function. Based on that time we compute next schedule time of
3750  * the request. When walking through the list is complete, compute
3751  * next waking time and put itself into sleep.
3752  */
3753 static int ext4_lazyinit_thread(void *arg)
3754 {
3755 	struct ext4_lazy_init *eli = arg;
3756 	struct list_head *pos, *n;
3757 	struct ext4_li_request *elr;
3758 	unsigned long next_wakeup, cur;
3759 
3760 	BUG_ON(NULL == eli);
3761 
3762 cont_thread:
3763 	while (true) {
3764 		next_wakeup = MAX_JIFFY_OFFSET;
3765 
3766 		mutex_lock(&eli->li_list_mtx);
3767 		if (list_empty(&eli->li_request_list)) {
3768 			mutex_unlock(&eli->li_list_mtx);
3769 			goto exit_thread;
3770 		}
3771 		list_for_each_safe(pos, n, &eli->li_request_list) {
3772 			int err = 0;
3773 			int progress = 0;
3774 			elr = list_entry(pos, struct ext4_li_request,
3775 					 lr_request);
3776 
3777 			if (time_before(jiffies, elr->lr_next_sched)) {
3778 				if (time_before(elr->lr_next_sched, next_wakeup))
3779 					next_wakeup = elr->lr_next_sched;
3780 				continue;
3781 			}
3782 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3783 				if (sb_start_write_trylock(elr->lr_super)) {
3784 					progress = 1;
3785 					/*
3786 					 * We hold sb->s_umount, sb can not
3787 					 * be removed from the list, it is
3788 					 * now safe to drop li_list_mtx
3789 					 */
3790 					mutex_unlock(&eli->li_list_mtx);
3791 					err = ext4_run_li_request(elr);
3792 					sb_end_write(elr->lr_super);
3793 					mutex_lock(&eli->li_list_mtx);
3794 					n = pos->next;
3795 				}
3796 				up_read((&elr->lr_super->s_umount));
3797 			}
3798 			/* error, remove the lazy_init job */
3799 			if (err) {
3800 				ext4_remove_li_request(elr);
3801 				continue;
3802 			}
3803 			if (!progress) {
3804 				elr->lr_next_sched = jiffies +
3805 					(prandom_u32()
3806 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3807 			}
3808 			if (time_before(elr->lr_next_sched, next_wakeup))
3809 				next_wakeup = elr->lr_next_sched;
3810 		}
3811 		mutex_unlock(&eli->li_list_mtx);
3812 
3813 		try_to_freeze();
3814 
3815 		cur = jiffies;
3816 		if ((time_after_eq(cur, next_wakeup)) ||
3817 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3818 			cond_resched();
3819 			continue;
3820 		}
3821 
3822 		schedule_timeout_interruptible(next_wakeup - cur);
3823 
3824 		if (kthread_should_stop()) {
3825 			ext4_clear_request_list();
3826 			goto exit_thread;
3827 		}
3828 	}
3829 
3830 exit_thread:
3831 	/*
3832 	 * It looks like the request list is empty, but we need
3833 	 * to check it under the li_list_mtx lock, to prevent any
3834 	 * additions into it, and of course we should lock ext4_li_mtx
3835 	 * to atomically free the list and ext4_li_info, because at
3836 	 * this point another ext4 filesystem could be registering
3837 	 * new one.
3838 	 */
3839 	mutex_lock(&ext4_li_mtx);
3840 	mutex_lock(&eli->li_list_mtx);
3841 	if (!list_empty(&eli->li_request_list)) {
3842 		mutex_unlock(&eli->li_list_mtx);
3843 		mutex_unlock(&ext4_li_mtx);
3844 		goto cont_thread;
3845 	}
3846 	mutex_unlock(&eli->li_list_mtx);
3847 	kfree(ext4_li_info);
3848 	ext4_li_info = NULL;
3849 	mutex_unlock(&ext4_li_mtx);
3850 
3851 	return 0;
3852 }
3853 
3854 static void ext4_clear_request_list(void)
3855 {
3856 	struct list_head *pos, *n;
3857 	struct ext4_li_request *elr;
3858 
3859 	mutex_lock(&ext4_li_info->li_list_mtx);
3860 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3861 		elr = list_entry(pos, struct ext4_li_request,
3862 				 lr_request);
3863 		ext4_remove_li_request(elr);
3864 	}
3865 	mutex_unlock(&ext4_li_info->li_list_mtx);
3866 }
3867 
3868 static int ext4_run_lazyinit_thread(void)
3869 {
3870 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3871 					 ext4_li_info, "ext4lazyinit");
3872 	if (IS_ERR(ext4_lazyinit_task)) {
3873 		int err = PTR_ERR(ext4_lazyinit_task);
3874 		ext4_clear_request_list();
3875 		kfree(ext4_li_info);
3876 		ext4_li_info = NULL;
3877 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3878 				 "initialization thread\n",
3879 				 err);
3880 		return err;
3881 	}
3882 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3883 	return 0;
3884 }
3885 
3886 /*
3887  * Check whether it make sense to run itable init. thread or not.
3888  * If there is at least one uninitialized inode table, return
3889  * corresponding group number, else the loop goes through all
3890  * groups and return total number of groups.
3891  */
3892 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3893 {
3894 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3895 	struct ext4_group_desc *gdp = NULL;
3896 
3897 	if (!ext4_has_group_desc_csum(sb))
3898 		return ngroups;
3899 
3900 	for (group = 0; group < ngroups; group++) {
3901 		gdp = ext4_get_group_desc(sb, group, NULL);
3902 		if (!gdp)
3903 			continue;
3904 
3905 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3906 			break;
3907 	}
3908 
3909 	return group;
3910 }
3911 
3912 static int ext4_li_info_new(void)
3913 {
3914 	struct ext4_lazy_init *eli = NULL;
3915 
3916 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3917 	if (!eli)
3918 		return -ENOMEM;
3919 
3920 	INIT_LIST_HEAD(&eli->li_request_list);
3921 	mutex_init(&eli->li_list_mtx);
3922 
3923 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3924 
3925 	ext4_li_info = eli;
3926 
3927 	return 0;
3928 }
3929 
3930 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3931 					    ext4_group_t start)
3932 {
3933 	struct ext4_li_request *elr;
3934 
3935 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3936 	if (!elr)
3937 		return NULL;
3938 
3939 	elr->lr_super = sb;
3940 	elr->lr_first_not_zeroed = start;
3941 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3942 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3943 		elr->lr_next_group = start;
3944 	} else {
3945 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3946 	}
3947 
3948 	/*
3949 	 * Randomize first schedule time of the request to
3950 	 * spread the inode table initialization requests
3951 	 * better.
3952 	 */
3953 	elr->lr_next_sched = jiffies + (prandom_u32() %
3954 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3955 	return elr;
3956 }
3957 
3958 int ext4_register_li_request(struct super_block *sb,
3959 			     ext4_group_t first_not_zeroed)
3960 {
3961 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3962 	struct ext4_li_request *elr = NULL;
3963 	ext4_group_t ngroups = sbi->s_groups_count;
3964 	int ret = 0;
3965 
3966 	mutex_lock(&ext4_li_mtx);
3967 	if (sbi->s_li_request != NULL) {
3968 		/*
3969 		 * Reset timeout so it can be computed again, because
3970 		 * s_li_wait_mult might have changed.
3971 		 */
3972 		sbi->s_li_request->lr_timeout = 0;
3973 		goto out;
3974 	}
3975 
3976 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3977 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3978 	     !test_opt(sb, INIT_INODE_TABLE)))
3979 		goto out;
3980 
3981 	elr = ext4_li_request_new(sb, first_not_zeroed);
3982 	if (!elr) {
3983 		ret = -ENOMEM;
3984 		goto out;
3985 	}
3986 
3987 	if (NULL == ext4_li_info) {
3988 		ret = ext4_li_info_new();
3989 		if (ret)
3990 			goto out;
3991 	}
3992 
3993 	mutex_lock(&ext4_li_info->li_list_mtx);
3994 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3995 	mutex_unlock(&ext4_li_info->li_list_mtx);
3996 
3997 	sbi->s_li_request = elr;
3998 	/*
3999 	 * set elr to NULL here since it has been inserted to
4000 	 * the request_list and the removal and free of it is
4001 	 * handled by ext4_clear_request_list from now on.
4002 	 */
4003 	elr = NULL;
4004 
4005 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4006 		ret = ext4_run_lazyinit_thread();
4007 		if (ret)
4008 			goto out;
4009 	}
4010 out:
4011 	mutex_unlock(&ext4_li_mtx);
4012 	if (ret)
4013 		kfree(elr);
4014 	return ret;
4015 }
4016 
4017 /*
4018  * We do not need to lock anything since this is called on
4019  * module unload.
4020  */
4021 static void ext4_destroy_lazyinit_thread(void)
4022 {
4023 	/*
4024 	 * If thread exited earlier
4025 	 * there's nothing to be done.
4026 	 */
4027 	if (!ext4_li_info || !ext4_lazyinit_task)
4028 		return;
4029 
4030 	kthread_stop(ext4_lazyinit_task);
4031 }
4032 
4033 static int set_journal_csum_feature_set(struct super_block *sb)
4034 {
4035 	int ret = 1;
4036 	int compat, incompat;
4037 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4038 
4039 	if (ext4_has_metadata_csum(sb)) {
4040 		/* journal checksum v3 */
4041 		compat = 0;
4042 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4043 	} else {
4044 		/* journal checksum v1 */
4045 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4046 		incompat = 0;
4047 	}
4048 
4049 	jbd2_journal_clear_features(sbi->s_journal,
4050 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4051 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4052 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4053 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4054 		ret = jbd2_journal_set_features(sbi->s_journal,
4055 				compat, 0,
4056 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4057 				incompat);
4058 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4059 		ret = jbd2_journal_set_features(sbi->s_journal,
4060 				compat, 0,
4061 				incompat);
4062 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4063 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4064 	} else {
4065 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4066 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4067 	}
4068 
4069 	return ret;
4070 }
4071 
4072 /*
4073  * Note: calculating the overhead so we can be compatible with
4074  * historical BSD practice is quite difficult in the face of
4075  * clusters/bigalloc.  This is because multiple metadata blocks from
4076  * different block group can end up in the same allocation cluster.
4077  * Calculating the exact overhead in the face of clustered allocation
4078  * requires either O(all block bitmaps) in memory or O(number of block
4079  * groups**2) in time.  We will still calculate the superblock for
4080  * older file systems --- and if we come across with a bigalloc file
4081  * system with zero in s_overhead_clusters the estimate will be close to
4082  * correct especially for very large cluster sizes --- but for newer
4083  * file systems, it's better to calculate this figure once at mkfs
4084  * time, and store it in the superblock.  If the superblock value is
4085  * present (even for non-bigalloc file systems), we will use it.
4086  */
4087 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4088 			  char *buf)
4089 {
4090 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4091 	struct ext4_group_desc	*gdp;
4092 	ext4_fsblk_t		first_block, last_block, b;
4093 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4094 	int			s, j, count = 0;
4095 	int			has_super = ext4_bg_has_super(sb, grp);
4096 
4097 	if (!ext4_has_feature_bigalloc(sb))
4098 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4099 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4100 			sbi->s_itb_per_group + 2);
4101 
4102 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4103 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4104 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4105 	for (i = 0; i < ngroups; i++) {
4106 		gdp = ext4_get_group_desc(sb, i, NULL);
4107 		b = ext4_block_bitmap(sb, gdp);
4108 		if (b >= first_block && b <= last_block) {
4109 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4110 			count++;
4111 		}
4112 		b = ext4_inode_bitmap(sb, gdp);
4113 		if (b >= first_block && b <= last_block) {
4114 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4115 			count++;
4116 		}
4117 		b = ext4_inode_table(sb, gdp);
4118 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4119 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4120 				int c = EXT4_B2C(sbi, b - first_block);
4121 				ext4_set_bit(c, buf);
4122 				count++;
4123 			}
4124 		if (i != grp)
4125 			continue;
4126 		s = 0;
4127 		if (ext4_bg_has_super(sb, grp)) {
4128 			ext4_set_bit(s++, buf);
4129 			count++;
4130 		}
4131 		j = ext4_bg_num_gdb(sb, grp);
4132 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4133 			ext4_error(sb, "Invalid number of block group "
4134 				   "descriptor blocks: %d", j);
4135 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4136 		}
4137 		count += j;
4138 		for (; j > 0; j--)
4139 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4140 	}
4141 	if (!count)
4142 		return 0;
4143 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4144 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4145 }
4146 
4147 /*
4148  * Compute the overhead and stash it in sbi->s_overhead
4149  */
4150 int ext4_calculate_overhead(struct super_block *sb)
4151 {
4152 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4153 	struct ext4_super_block *es = sbi->s_es;
4154 	struct inode *j_inode;
4155 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4156 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4157 	ext4_fsblk_t overhead = 0;
4158 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4159 
4160 	if (!buf)
4161 		return -ENOMEM;
4162 
4163 	/*
4164 	 * Compute the overhead (FS structures).  This is constant
4165 	 * for a given filesystem unless the number of block groups
4166 	 * changes so we cache the previous value until it does.
4167 	 */
4168 
4169 	/*
4170 	 * All of the blocks before first_data_block are overhead
4171 	 */
4172 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4173 
4174 	/*
4175 	 * Add the overhead found in each block group
4176 	 */
4177 	for (i = 0; i < ngroups; i++) {
4178 		int blks;
4179 
4180 		blks = count_overhead(sb, i, buf);
4181 		overhead += blks;
4182 		if (blks)
4183 			memset(buf, 0, PAGE_SIZE);
4184 		cond_resched();
4185 	}
4186 
4187 	/*
4188 	 * Add the internal journal blocks whether the journal has been
4189 	 * loaded or not
4190 	 */
4191 	if (sbi->s_journal && !sbi->s_journal_bdev)
4192 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4193 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4194 		/* j_inum for internal journal is non-zero */
4195 		j_inode = ext4_get_journal_inode(sb, j_inum);
4196 		if (j_inode) {
4197 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4198 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4199 			iput(j_inode);
4200 		} else {
4201 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4202 		}
4203 	}
4204 	sbi->s_overhead = overhead;
4205 	smp_wmb();
4206 	free_page((unsigned long) buf);
4207 	return 0;
4208 }
4209 
4210 static void ext4_set_resv_clusters(struct super_block *sb)
4211 {
4212 	ext4_fsblk_t resv_clusters;
4213 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4214 
4215 	/*
4216 	 * There's no need to reserve anything when we aren't using extents.
4217 	 * The space estimates are exact, there are no unwritten extents,
4218 	 * hole punching doesn't need new metadata... This is needed especially
4219 	 * to keep ext2/3 backward compatibility.
4220 	 */
4221 	if (!ext4_has_feature_extents(sb))
4222 		return;
4223 	/*
4224 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4225 	 * This should cover the situations where we can not afford to run
4226 	 * out of space like for example punch hole, or converting
4227 	 * unwritten extents in delalloc path. In most cases such
4228 	 * allocation would require 1, or 2 blocks, higher numbers are
4229 	 * very rare.
4230 	 */
4231 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4232 			 sbi->s_cluster_bits);
4233 
4234 	do_div(resv_clusters, 50);
4235 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4236 
4237 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4238 }
4239 
4240 static const char *ext4_quota_mode(struct super_block *sb)
4241 {
4242 #ifdef CONFIG_QUOTA
4243 	if (!ext4_quota_capable(sb))
4244 		return "none";
4245 
4246 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4247 		return "journalled";
4248 	else
4249 		return "writeback";
4250 #else
4251 	return "disabled";
4252 #endif
4253 }
4254 
4255 static void ext4_setup_csum_trigger(struct super_block *sb,
4256 				    enum ext4_journal_trigger_type type,
4257 				    void (*trigger)(
4258 					struct jbd2_buffer_trigger_type *type,
4259 					struct buffer_head *bh,
4260 					void *mapped_data,
4261 					size_t size))
4262 {
4263 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4264 
4265 	sbi->s_journal_triggers[type].sb = sb;
4266 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4267 }
4268 
4269 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4270 {
4271 	if (!sbi)
4272 		return;
4273 
4274 	kfree(sbi->s_blockgroup_lock);
4275 	fs_put_dax(sbi->s_daxdev);
4276 	kfree(sbi);
4277 }
4278 
4279 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4280 {
4281 	struct ext4_sb_info *sbi;
4282 
4283 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4284 	if (!sbi)
4285 		return NULL;
4286 
4287 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off);
4288 
4289 	sbi->s_blockgroup_lock =
4290 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4291 
4292 	if (!sbi->s_blockgroup_lock)
4293 		goto err_out;
4294 
4295 	sb->s_fs_info = sbi;
4296 	sbi->s_sb = sb;
4297 	return sbi;
4298 err_out:
4299 	fs_put_dax(sbi->s_daxdev);
4300 	kfree(sbi);
4301 	return NULL;
4302 }
4303 
4304 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
4305 {
4306 	struct buffer_head *bh, **group_desc;
4307 	struct ext4_super_block *es = NULL;
4308 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4309 	struct flex_groups **flex_groups;
4310 	ext4_fsblk_t block;
4311 	ext4_fsblk_t logical_sb_block;
4312 	unsigned long offset = 0;
4313 	unsigned long def_mount_opts;
4314 	struct inode *root;
4315 	int ret = -ENOMEM;
4316 	int blocksize, clustersize;
4317 	unsigned int db_count;
4318 	unsigned int i;
4319 	int needs_recovery, has_huge_files;
4320 	__u64 blocks_count;
4321 	int err = 0;
4322 	ext4_group_t first_not_zeroed;
4323 	struct ext4_fs_context *ctx = fc->fs_private;
4324 	int silent = fc->sb_flags & SB_SILENT;
4325 
4326 	/* Set defaults for the variables that will be set during parsing */
4327 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
4328 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4329 
4330 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4331 	sbi->s_sectors_written_start =
4332 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4333 
4334 	/* -EINVAL is default */
4335 	ret = -EINVAL;
4336 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4337 	if (!blocksize) {
4338 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4339 		goto out_fail;
4340 	}
4341 
4342 	/*
4343 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4344 	 * block sizes.  We need to calculate the offset from buffer start.
4345 	 */
4346 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4347 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4348 		offset = do_div(logical_sb_block, blocksize);
4349 	} else {
4350 		logical_sb_block = sbi->s_sb_block;
4351 	}
4352 
4353 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4354 	if (IS_ERR(bh)) {
4355 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4356 		ret = PTR_ERR(bh);
4357 		goto out_fail;
4358 	}
4359 	/*
4360 	 * Note: s_es must be initialized as soon as possible because
4361 	 *       some ext4 macro-instructions depend on its value
4362 	 */
4363 	es = (struct ext4_super_block *) (bh->b_data + offset);
4364 	sbi->s_es = es;
4365 	sb->s_magic = le16_to_cpu(es->s_magic);
4366 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4367 		goto cantfind_ext4;
4368 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4369 
4370 	/* Warn if metadata_csum and gdt_csum are both set. */
4371 	if (ext4_has_feature_metadata_csum(sb) &&
4372 	    ext4_has_feature_gdt_csum(sb))
4373 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4374 			     "redundant flags; please run fsck.");
4375 
4376 	/* Check for a known checksum algorithm */
4377 	if (!ext4_verify_csum_type(sb, es)) {
4378 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4379 			 "unknown checksum algorithm.");
4380 		silent = 1;
4381 		goto cantfind_ext4;
4382 	}
4383 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4384 				ext4_orphan_file_block_trigger);
4385 
4386 	/* Load the checksum driver */
4387 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4388 	if (IS_ERR(sbi->s_chksum_driver)) {
4389 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4390 		ret = PTR_ERR(sbi->s_chksum_driver);
4391 		sbi->s_chksum_driver = NULL;
4392 		goto failed_mount;
4393 	}
4394 
4395 	/* Check superblock checksum */
4396 	if (!ext4_superblock_csum_verify(sb, es)) {
4397 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4398 			 "invalid superblock checksum.  Run e2fsck?");
4399 		silent = 1;
4400 		ret = -EFSBADCRC;
4401 		goto cantfind_ext4;
4402 	}
4403 
4404 	/* Precompute checksum seed for all metadata */
4405 	if (ext4_has_feature_csum_seed(sb))
4406 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4407 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4408 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4409 					       sizeof(es->s_uuid));
4410 
4411 	/* Set defaults before we parse the mount options */
4412 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4413 	set_opt(sb, INIT_INODE_TABLE);
4414 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4415 		set_opt(sb, DEBUG);
4416 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4417 		set_opt(sb, GRPID);
4418 	if (def_mount_opts & EXT4_DEFM_UID16)
4419 		set_opt(sb, NO_UID32);
4420 	/* xattr user namespace & acls are now defaulted on */
4421 	set_opt(sb, XATTR_USER);
4422 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4423 	set_opt(sb, POSIX_ACL);
4424 #endif
4425 	if (ext4_has_feature_fast_commit(sb))
4426 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4427 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4428 	if (ext4_has_metadata_csum(sb))
4429 		set_opt(sb, JOURNAL_CHECKSUM);
4430 
4431 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4432 		set_opt(sb, JOURNAL_DATA);
4433 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4434 		set_opt(sb, ORDERED_DATA);
4435 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4436 		set_opt(sb, WRITEBACK_DATA);
4437 
4438 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4439 		set_opt(sb, ERRORS_PANIC);
4440 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4441 		set_opt(sb, ERRORS_CONT);
4442 	else
4443 		set_opt(sb, ERRORS_RO);
4444 	/* block_validity enabled by default; disable with noblock_validity */
4445 	set_opt(sb, BLOCK_VALIDITY);
4446 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4447 		set_opt(sb, DISCARD);
4448 
4449 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4450 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4451 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4452 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4453 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4454 
4455 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4456 		set_opt(sb, BARRIER);
4457 
4458 	/*
4459 	 * enable delayed allocation by default
4460 	 * Use -o nodelalloc to turn it off
4461 	 */
4462 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4463 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4464 		set_opt(sb, DELALLOC);
4465 
4466 	/*
4467 	 * set default s_li_wait_mult for lazyinit, for the case there is
4468 	 * no mount option specified.
4469 	 */
4470 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4471 
4472 	if (le32_to_cpu(es->s_log_block_size) >
4473 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4474 		ext4_msg(sb, KERN_ERR,
4475 			 "Invalid log block size: %u",
4476 			 le32_to_cpu(es->s_log_block_size));
4477 		goto failed_mount;
4478 	}
4479 	if (le32_to_cpu(es->s_log_cluster_size) >
4480 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4481 		ext4_msg(sb, KERN_ERR,
4482 			 "Invalid log cluster size: %u",
4483 			 le32_to_cpu(es->s_log_cluster_size));
4484 		goto failed_mount;
4485 	}
4486 
4487 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4488 
4489 	if (blocksize == PAGE_SIZE)
4490 		set_opt(sb, DIOREAD_NOLOCK);
4491 
4492 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4493 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4494 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4495 	} else {
4496 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4497 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4498 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4499 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4500 				 sbi->s_first_ino);
4501 			goto failed_mount;
4502 		}
4503 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4504 		    (!is_power_of_2(sbi->s_inode_size)) ||
4505 		    (sbi->s_inode_size > blocksize)) {
4506 			ext4_msg(sb, KERN_ERR,
4507 			       "unsupported inode size: %d",
4508 			       sbi->s_inode_size);
4509 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4510 			goto failed_mount;
4511 		}
4512 		/*
4513 		 * i_atime_extra is the last extra field available for
4514 		 * [acm]times in struct ext4_inode. Checking for that
4515 		 * field should suffice to ensure we have extra space
4516 		 * for all three.
4517 		 */
4518 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4519 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4520 			sb->s_time_gran = 1;
4521 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4522 		} else {
4523 			sb->s_time_gran = NSEC_PER_SEC;
4524 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4525 		}
4526 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4527 	}
4528 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4529 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4530 			EXT4_GOOD_OLD_INODE_SIZE;
4531 		if (ext4_has_feature_extra_isize(sb)) {
4532 			unsigned v, max = (sbi->s_inode_size -
4533 					   EXT4_GOOD_OLD_INODE_SIZE);
4534 
4535 			v = le16_to_cpu(es->s_want_extra_isize);
4536 			if (v > max) {
4537 				ext4_msg(sb, KERN_ERR,
4538 					 "bad s_want_extra_isize: %d", v);
4539 				goto failed_mount;
4540 			}
4541 			if (sbi->s_want_extra_isize < v)
4542 				sbi->s_want_extra_isize = v;
4543 
4544 			v = le16_to_cpu(es->s_min_extra_isize);
4545 			if (v > max) {
4546 				ext4_msg(sb, KERN_ERR,
4547 					 "bad s_min_extra_isize: %d", v);
4548 				goto failed_mount;
4549 			}
4550 			if (sbi->s_want_extra_isize < v)
4551 				sbi->s_want_extra_isize = v;
4552 		}
4553 	}
4554 
4555 	err = parse_apply_sb_mount_options(sb, ctx);
4556 	if (err < 0)
4557 		goto failed_mount;
4558 
4559 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4560 
4561 	err = ext4_check_opt_consistency(fc, sb);
4562 	if (err < 0)
4563 		goto failed_mount;
4564 
4565 	ext4_apply_options(fc, sb);
4566 
4567 #if IS_ENABLED(CONFIG_UNICODE)
4568 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4569 		const struct ext4_sb_encodings *encoding_info;
4570 		struct unicode_map *encoding;
4571 		__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4572 
4573 		encoding_info = ext4_sb_read_encoding(es);
4574 		if (!encoding_info) {
4575 			ext4_msg(sb, KERN_ERR,
4576 				 "Encoding requested by superblock is unknown");
4577 			goto failed_mount;
4578 		}
4579 
4580 		encoding = utf8_load(encoding_info->version);
4581 		if (IS_ERR(encoding)) {
4582 			ext4_msg(sb, KERN_ERR,
4583 				 "can't mount with superblock charset: %s-%u.%u.%u "
4584 				 "not supported by the kernel. flags: 0x%x.",
4585 				 encoding_info->name,
4586 				 unicode_major(encoding_info->version),
4587 				 unicode_minor(encoding_info->version),
4588 				 unicode_rev(encoding_info->version),
4589 				 encoding_flags);
4590 			goto failed_mount;
4591 		}
4592 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4593 			 "%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4594 			 unicode_major(encoding_info->version),
4595 			 unicode_minor(encoding_info->version),
4596 			 unicode_rev(encoding_info->version),
4597 			 encoding_flags);
4598 
4599 		sb->s_encoding = encoding;
4600 		sb->s_encoding_flags = encoding_flags;
4601 	}
4602 #endif
4603 
4604 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4605 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4606 		/* can't mount with both data=journal and dioread_nolock. */
4607 		clear_opt(sb, DIOREAD_NOLOCK);
4608 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4609 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4610 			ext4_msg(sb, KERN_ERR, "can't mount with "
4611 				 "both data=journal and delalloc");
4612 			goto failed_mount;
4613 		}
4614 		if (test_opt(sb, DAX_ALWAYS)) {
4615 			ext4_msg(sb, KERN_ERR, "can't mount with "
4616 				 "both data=journal and dax");
4617 			goto failed_mount;
4618 		}
4619 		if (ext4_has_feature_encrypt(sb)) {
4620 			ext4_msg(sb, KERN_WARNING,
4621 				 "encrypted files will use data=ordered "
4622 				 "instead of data journaling mode");
4623 		}
4624 		if (test_opt(sb, DELALLOC))
4625 			clear_opt(sb, DELALLOC);
4626 	} else {
4627 		sb->s_iflags |= SB_I_CGROUPWB;
4628 	}
4629 
4630 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4631 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4632 
4633 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4634 	    (ext4_has_compat_features(sb) ||
4635 	     ext4_has_ro_compat_features(sb) ||
4636 	     ext4_has_incompat_features(sb)))
4637 		ext4_msg(sb, KERN_WARNING,
4638 		       "feature flags set on rev 0 fs, "
4639 		       "running e2fsck is recommended");
4640 
4641 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4642 		set_opt2(sb, HURD_COMPAT);
4643 		if (ext4_has_feature_64bit(sb)) {
4644 			ext4_msg(sb, KERN_ERR,
4645 				 "The Hurd can't support 64-bit file systems");
4646 			goto failed_mount;
4647 		}
4648 
4649 		/*
4650 		 * ea_inode feature uses l_i_version field which is not
4651 		 * available in HURD_COMPAT mode.
4652 		 */
4653 		if (ext4_has_feature_ea_inode(sb)) {
4654 			ext4_msg(sb, KERN_ERR,
4655 				 "ea_inode feature is not supported for Hurd");
4656 			goto failed_mount;
4657 		}
4658 	}
4659 
4660 	if (IS_EXT2_SB(sb)) {
4661 		if (ext2_feature_set_ok(sb))
4662 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4663 				 "using the ext4 subsystem");
4664 		else {
4665 			/*
4666 			 * If we're probing be silent, if this looks like
4667 			 * it's actually an ext[34] filesystem.
4668 			 */
4669 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4670 				goto failed_mount;
4671 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4672 				 "to feature incompatibilities");
4673 			goto failed_mount;
4674 		}
4675 	}
4676 
4677 	if (IS_EXT3_SB(sb)) {
4678 		if (ext3_feature_set_ok(sb))
4679 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4680 				 "using the ext4 subsystem");
4681 		else {
4682 			/*
4683 			 * If we're probing be silent, if this looks like
4684 			 * it's actually an ext4 filesystem.
4685 			 */
4686 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4687 				goto failed_mount;
4688 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4689 				 "to feature incompatibilities");
4690 			goto failed_mount;
4691 		}
4692 	}
4693 
4694 	/*
4695 	 * Check feature flags regardless of the revision level, since we
4696 	 * previously didn't change the revision level when setting the flags,
4697 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4698 	 */
4699 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4700 		goto failed_mount;
4701 
4702 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4703 		ext4_msg(sb, KERN_ERR,
4704 			 "Number of reserved GDT blocks insanely large: %d",
4705 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4706 		goto failed_mount;
4707 	}
4708 
4709 	if (sbi->s_daxdev) {
4710 		if (blocksize == PAGE_SIZE)
4711 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4712 		else
4713 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4714 	}
4715 
4716 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4717 		if (ext4_has_feature_inline_data(sb)) {
4718 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4719 					" that may contain inline data");
4720 			goto failed_mount;
4721 		}
4722 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4723 			ext4_msg(sb, KERN_ERR,
4724 				"DAX unsupported by block device.");
4725 			goto failed_mount;
4726 		}
4727 	}
4728 
4729 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4730 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4731 			 es->s_encryption_level);
4732 		goto failed_mount;
4733 	}
4734 
4735 	if (sb->s_blocksize != blocksize) {
4736 		/*
4737 		 * bh must be released before kill_bdev(), otherwise
4738 		 * it won't be freed and its page also. kill_bdev()
4739 		 * is called by sb_set_blocksize().
4740 		 */
4741 		brelse(bh);
4742 		/* Validate the filesystem blocksize */
4743 		if (!sb_set_blocksize(sb, blocksize)) {
4744 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4745 					blocksize);
4746 			bh = NULL;
4747 			goto failed_mount;
4748 		}
4749 
4750 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4751 		offset = do_div(logical_sb_block, blocksize);
4752 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4753 		if (IS_ERR(bh)) {
4754 			ext4_msg(sb, KERN_ERR,
4755 			       "Can't read superblock on 2nd try");
4756 			ret = PTR_ERR(bh);
4757 			bh = NULL;
4758 			goto failed_mount;
4759 		}
4760 		es = (struct ext4_super_block *)(bh->b_data + offset);
4761 		sbi->s_es = es;
4762 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4763 			ext4_msg(sb, KERN_ERR,
4764 			       "Magic mismatch, very weird!");
4765 			goto failed_mount;
4766 		}
4767 	}
4768 
4769 	has_huge_files = ext4_has_feature_huge_file(sb);
4770 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4771 						      has_huge_files);
4772 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4773 
4774 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4775 	if (ext4_has_feature_64bit(sb)) {
4776 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4777 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4778 		    !is_power_of_2(sbi->s_desc_size)) {
4779 			ext4_msg(sb, KERN_ERR,
4780 			       "unsupported descriptor size %lu",
4781 			       sbi->s_desc_size);
4782 			goto failed_mount;
4783 		}
4784 	} else
4785 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4786 
4787 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4788 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4789 
4790 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4791 	if (sbi->s_inodes_per_block == 0)
4792 		goto cantfind_ext4;
4793 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4794 	    sbi->s_inodes_per_group > blocksize * 8) {
4795 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4796 			 sbi->s_inodes_per_group);
4797 		goto failed_mount;
4798 	}
4799 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4800 					sbi->s_inodes_per_block;
4801 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4802 	sbi->s_sbh = bh;
4803 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
4804 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4805 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4806 
4807 	for (i = 0; i < 4; i++)
4808 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4809 	sbi->s_def_hash_version = es->s_def_hash_version;
4810 	if (ext4_has_feature_dir_index(sb)) {
4811 		i = le32_to_cpu(es->s_flags);
4812 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4813 			sbi->s_hash_unsigned = 3;
4814 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4815 #ifdef __CHAR_UNSIGNED__
4816 			if (!sb_rdonly(sb))
4817 				es->s_flags |=
4818 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4819 			sbi->s_hash_unsigned = 3;
4820 #else
4821 			if (!sb_rdonly(sb))
4822 				es->s_flags |=
4823 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4824 #endif
4825 		}
4826 	}
4827 
4828 	/* Handle clustersize */
4829 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4830 	if (ext4_has_feature_bigalloc(sb)) {
4831 		if (clustersize < blocksize) {
4832 			ext4_msg(sb, KERN_ERR,
4833 				 "cluster size (%d) smaller than "
4834 				 "block size (%d)", clustersize, blocksize);
4835 			goto failed_mount;
4836 		}
4837 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4838 			le32_to_cpu(es->s_log_block_size);
4839 		sbi->s_clusters_per_group =
4840 			le32_to_cpu(es->s_clusters_per_group);
4841 		if (sbi->s_clusters_per_group > blocksize * 8) {
4842 			ext4_msg(sb, KERN_ERR,
4843 				 "#clusters per group too big: %lu",
4844 				 sbi->s_clusters_per_group);
4845 			goto failed_mount;
4846 		}
4847 		if (sbi->s_blocks_per_group !=
4848 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4849 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4850 				 "clusters per group (%lu) inconsistent",
4851 				 sbi->s_blocks_per_group,
4852 				 sbi->s_clusters_per_group);
4853 			goto failed_mount;
4854 		}
4855 	} else {
4856 		if (clustersize != blocksize) {
4857 			ext4_msg(sb, KERN_ERR,
4858 				 "fragment/cluster size (%d) != "
4859 				 "block size (%d)", clustersize, blocksize);
4860 			goto failed_mount;
4861 		}
4862 		if (sbi->s_blocks_per_group > blocksize * 8) {
4863 			ext4_msg(sb, KERN_ERR,
4864 				 "#blocks per group too big: %lu",
4865 				 sbi->s_blocks_per_group);
4866 			goto failed_mount;
4867 		}
4868 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4869 		sbi->s_cluster_bits = 0;
4870 	}
4871 	sbi->s_cluster_ratio = clustersize / blocksize;
4872 
4873 	/* Do we have standard group size of clustersize * 8 blocks ? */
4874 	if (sbi->s_blocks_per_group == clustersize << 3)
4875 		set_opt2(sb, STD_GROUP_SIZE);
4876 
4877 	/*
4878 	 * Test whether we have more sectors than will fit in sector_t,
4879 	 * and whether the max offset is addressable by the page cache.
4880 	 */
4881 	err = generic_check_addressable(sb->s_blocksize_bits,
4882 					ext4_blocks_count(es));
4883 	if (err) {
4884 		ext4_msg(sb, KERN_ERR, "filesystem"
4885 			 " too large to mount safely on this system");
4886 		goto failed_mount;
4887 	}
4888 
4889 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4890 		goto cantfind_ext4;
4891 
4892 	/* check blocks count against device size */
4893 	blocks_count = sb_bdev_nr_blocks(sb);
4894 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4895 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4896 		       "exceeds size of device (%llu blocks)",
4897 		       ext4_blocks_count(es), blocks_count);
4898 		goto failed_mount;
4899 	}
4900 
4901 	/*
4902 	 * It makes no sense for the first data block to be beyond the end
4903 	 * of the filesystem.
4904 	 */
4905 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4906 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4907 			 "block %u is beyond end of filesystem (%llu)",
4908 			 le32_to_cpu(es->s_first_data_block),
4909 			 ext4_blocks_count(es));
4910 		goto failed_mount;
4911 	}
4912 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4913 	    (sbi->s_cluster_ratio == 1)) {
4914 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4915 			 "block is 0 with a 1k block and cluster size");
4916 		goto failed_mount;
4917 	}
4918 
4919 	blocks_count = (ext4_blocks_count(es) -
4920 			le32_to_cpu(es->s_first_data_block) +
4921 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4922 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4923 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4924 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4925 		       "(block count %llu, first data block %u, "
4926 		       "blocks per group %lu)", blocks_count,
4927 		       ext4_blocks_count(es),
4928 		       le32_to_cpu(es->s_first_data_block),
4929 		       EXT4_BLOCKS_PER_GROUP(sb));
4930 		goto failed_mount;
4931 	}
4932 	sbi->s_groups_count = blocks_count;
4933 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4934 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4935 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4936 	    le32_to_cpu(es->s_inodes_count)) {
4937 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4938 			 le32_to_cpu(es->s_inodes_count),
4939 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4940 		ret = -EINVAL;
4941 		goto failed_mount;
4942 	}
4943 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4944 		   EXT4_DESC_PER_BLOCK(sb);
4945 	if (ext4_has_feature_meta_bg(sb)) {
4946 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4947 			ext4_msg(sb, KERN_WARNING,
4948 				 "first meta block group too large: %u "
4949 				 "(group descriptor block count %u)",
4950 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4951 			goto failed_mount;
4952 		}
4953 	}
4954 	rcu_assign_pointer(sbi->s_group_desc,
4955 			   kvmalloc_array(db_count,
4956 					  sizeof(struct buffer_head *),
4957 					  GFP_KERNEL));
4958 	if (sbi->s_group_desc == NULL) {
4959 		ext4_msg(sb, KERN_ERR, "not enough memory");
4960 		ret = -ENOMEM;
4961 		goto failed_mount;
4962 	}
4963 
4964 	bgl_lock_init(sbi->s_blockgroup_lock);
4965 
4966 	/* Pre-read the descriptors into the buffer cache */
4967 	for (i = 0; i < db_count; i++) {
4968 		block = descriptor_loc(sb, logical_sb_block, i);
4969 		ext4_sb_breadahead_unmovable(sb, block);
4970 	}
4971 
4972 	for (i = 0; i < db_count; i++) {
4973 		struct buffer_head *bh;
4974 
4975 		block = descriptor_loc(sb, logical_sb_block, i);
4976 		bh = ext4_sb_bread_unmovable(sb, block);
4977 		if (IS_ERR(bh)) {
4978 			ext4_msg(sb, KERN_ERR,
4979 			       "can't read group descriptor %d", i);
4980 			db_count = i;
4981 			ret = PTR_ERR(bh);
4982 			goto failed_mount2;
4983 		}
4984 		rcu_read_lock();
4985 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4986 		rcu_read_unlock();
4987 	}
4988 	sbi->s_gdb_count = db_count;
4989 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4990 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4991 		ret = -EFSCORRUPTED;
4992 		goto failed_mount2;
4993 	}
4994 
4995 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4996 	spin_lock_init(&sbi->s_error_lock);
4997 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
4998 
4999 	/* Register extent status tree shrinker */
5000 	if (ext4_es_register_shrinker(sbi))
5001 		goto failed_mount3;
5002 
5003 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5004 	sbi->s_extent_max_zeroout_kb = 32;
5005 
5006 	/*
5007 	 * set up enough so that it can read an inode
5008 	 */
5009 	sb->s_op = &ext4_sops;
5010 	sb->s_export_op = &ext4_export_ops;
5011 	sb->s_xattr = ext4_xattr_handlers;
5012 #ifdef CONFIG_FS_ENCRYPTION
5013 	sb->s_cop = &ext4_cryptops;
5014 #endif
5015 #ifdef CONFIG_FS_VERITY
5016 	sb->s_vop = &ext4_verityops;
5017 #endif
5018 #ifdef CONFIG_QUOTA
5019 	sb->dq_op = &ext4_quota_operations;
5020 	if (ext4_has_feature_quota(sb))
5021 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5022 	else
5023 		sb->s_qcop = &ext4_qctl_operations;
5024 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5025 #endif
5026 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5027 
5028 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5029 	mutex_init(&sbi->s_orphan_lock);
5030 
5031 	/* Initialize fast commit stuff */
5032 	atomic_set(&sbi->s_fc_subtid, 0);
5033 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
5034 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
5035 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
5036 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
5037 	sbi->s_fc_bytes = 0;
5038 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
5039 	sbi->s_fc_ineligible_tid = 0;
5040 	spin_lock_init(&sbi->s_fc_lock);
5041 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
5042 	sbi->s_fc_replay_state.fc_regions = NULL;
5043 	sbi->s_fc_replay_state.fc_regions_size = 0;
5044 	sbi->s_fc_replay_state.fc_regions_used = 0;
5045 	sbi->s_fc_replay_state.fc_regions_valid = 0;
5046 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
5047 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
5048 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
5049 
5050 	sb->s_root = NULL;
5051 
5052 	needs_recovery = (es->s_last_orphan != 0 ||
5053 			  ext4_has_feature_orphan_present(sb) ||
5054 			  ext4_has_feature_journal_needs_recovery(sb));
5055 
5056 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5057 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5058 			goto failed_mount3a;
5059 
5060 	/*
5061 	 * The first inode we look at is the journal inode.  Don't try
5062 	 * root first: it may be modified in the journal!
5063 	 */
5064 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5065 		err = ext4_load_journal(sb, es, ctx->journal_devnum);
5066 		if (err)
5067 			goto failed_mount3a;
5068 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5069 		   ext4_has_feature_journal_needs_recovery(sb)) {
5070 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5071 		       "suppressed and not mounted read-only");
5072 		goto failed_mount_wq;
5073 	} else {
5074 		/* Nojournal mode, all journal mount options are illegal */
5075 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5076 			ext4_msg(sb, KERN_ERR, "can't mount with "
5077 				 "journal_checksum, fs mounted w/o journal");
5078 			goto failed_mount_wq;
5079 		}
5080 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5081 			ext4_msg(sb, KERN_ERR, "can't mount with "
5082 				 "journal_async_commit, fs mounted w/o journal");
5083 			goto failed_mount_wq;
5084 		}
5085 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5086 			ext4_msg(sb, KERN_ERR, "can't mount with "
5087 				 "commit=%lu, fs mounted w/o journal",
5088 				 sbi->s_commit_interval / HZ);
5089 			goto failed_mount_wq;
5090 		}
5091 		if (EXT4_MOUNT_DATA_FLAGS &
5092 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5093 			ext4_msg(sb, KERN_ERR, "can't mount with "
5094 				 "data=, fs mounted w/o journal");
5095 			goto failed_mount_wq;
5096 		}
5097 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5098 		clear_opt(sb, JOURNAL_CHECKSUM);
5099 		clear_opt(sb, DATA_FLAGS);
5100 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5101 		sbi->s_journal = NULL;
5102 		needs_recovery = 0;
5103 		goto no_journal;
5104 	}
5105 
5106 	if (ext4_has_feature_64bit(sb) &&
5107 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5108 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
5109 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
5110 		goto failed_mount_wq;
5111 	}
5112 
5113 	if (!set_journal_csum_feature_set(sb)) {
5114 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
5115 			 "feature set");
5116 		goto failed_mount_wq;
5117 	}
5118 
5119 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
5120 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5121 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
5122 		ext4_msg(sb, KERN_ERR,
5123 			"Failed to set fast commit journal feature");
5124 		goto failed_mount_wq;
5125 	}
5126 
5127 	/* We have now updated the journal if required, so we can
5128 	 * validate the data journaling mode. */
5129 	switch (test_opt(sb, DATA_FLAGS)) {
5130 	case 0:
5131 		/* No mode set, assume a default based on the journal
5132 		 * capabilities: ORDERED_DATA if the journal can
5133 		 * cope, else JOURNAL_DATA
5134 		 */
5135 		if (jbd2_journal_check_available_features
5136 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5137 			set_opt(sb, ORDERED_DATA);
5138 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
5139 		} else {
5140 			set_opt(sb, JOURNAL_DATA);
5141 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
5142 		}
5143 		break;
5144 
5145 	case EXT4_MOUNT_ORDERED_DATA:
5146 	case EXT4_MOUNT_WRITEBACK_DATA:
5147 		if (!jbd2_journal_check_available_features
5148 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5149 			ext4_msg(sb, KERN_ERR, "Journal does not support "
5150 			       "requested data journaling mode");
5151 			goto failed_mount_wq;
5152 		}
5153 		break;
5154 	default:
5155 		break;
5156 	}
5157 
5158 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5159 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5160 		ext4_msg(sb, KERN_ERR, "can't mount with "
5161 			"journal_async_commit in data=ordered mode");
5162 		goto failed_mount_wq;
5163 	}
5164 
5165 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5166 
5167 	sbi->s_journal->j_submit_inode_data_buffers =
5168 		ext4_journal_submit_inode_data_buffers;
5169 	sbi->s_journal->j_finish_inode_data_buffers =
5170 		ext4_journal_finish_inode_data_buffers;
5171 
5172 no_journal:
5173 	if (!test_opt(sb, NO_MBCACHE)) {
5174 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5175 		if (!sbi->s_ea_block_cache) {
5176 			ext4_msg(sb, KERN_ERR,
5177 				 "Failed to create ea_block_cache");
5178 			goto failed_mount_wq;
5179 		}
5180 
5181 		if (ext4_has_feature_ea_inode(sb)) {
5182 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5183 			if (!sbi->s_ea_inode_cache) {
5184 				ext4_msg(sb, KERN_ERR,
5185 					 "Failed to create ea_inode_cache");
5186 				goto failed_mount_wq;
5187 			}
5188 		}
5189 	}
5190 
5191 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
5192 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5193 		goto failed_mount_wq;
5194 	}
5195 
5196 	/*
5197 	 * Get the # of file system overhead blocks from the
5198 	 * superblock if present.
5199 	 */
5200 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5201 	/* ignore the precalculated value if it is ridiculous */
5202 	if (sbi->s_overhead > ext4_blocks_count(es))
5203 		sbi->s_overhead = 0;
5204 	/*
5205 	 * If the bigalloc feature is not enabled recalculating the
5206 	 * overhead doesn't take long, so we might as well just redo
5207 	 * it to make sure we are using the correct value.
5208 	 */
5209 	if (!ext4_has_feature_bigalloc(sb))
5210 		sbi->s_overhead = 0;
5211 	if (sbi->s_overhead == 0) {
5212 		err = ext4_calculate_overhead(sb);
5213 		if (err)
5214 			goto failed_mount_wq;
5215 	}
5216 
5217 	/*
5218 	 * The maximum number of concurrent works can be high and
5219 	 * concurrency isn't really necessary.  Limit it to 1.
5220 	 */
5221 	EXT4_SB(sb)->rsv_conversion_wq =
5222 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5223 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5224 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5225 		ret = -ENOMEM;
5226 		goto failed_mount4;
5227 	}
5228 
5229 	/*
5230 	 * The jbd2_journal_load will have done any necessary log recovery,
5231 	 * so we can safely mount the rest of the filesystem now.
5232 	 */
5233 
5234 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5235 	if (IS_ERR(root)) {
5236 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5237 		ret = PTR_ERR(root);
5238 		root = NULL;
5239 		goto failed_mount4;
5240 	}
5241 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5242 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5243 		iput(root);
5244 		goto failed_mount4;
5245 	}
5246 
5247 	sb->s_root = d_make_root(root);
5248 	if (!sb->s_root) {
5249 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5250 		ret = -ENOMEM;
5251 		goto failed_mount4;
5252 	}
5253 
5254 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5255 	if (ret == -EROFS) {
5256 		sb->s_flags |= SB_RDONLY;
5257 		ret = 0;
5258 	} else if (ret)
5259 		goto failed_mount4a;
5260 
5261 	ext4_set_resv_clusters(sb);
5262 
5263 	if (test_opt(sb, BLOCK_VALIDITY)) {
5264 		err = ext4_setup_system_zone(sb);
5265 		if (err) {
5266 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5267 				 "zone (%d)", err);
5268 			goto failed_mount4a;
5269 		}
5270 	}
5271 	ext4_fc_replay_cleanup(sb);
5272 
5273 	ext4_ext_init(sb);
5274 
5275 	/*
5276 	 * Enable optimize_scan if number of groups is > threshold. This can be
5277 	 * turned off by passing "mb_optimize_scan=0". This can also be
5278 	 * turned on forcefully by passing "mb_optimize_scan=1".
5279 	 */
5280 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5281 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5282 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5283 		else
5284 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5285 	}
5286 
5287 	err = ext4_mb_init(sb);
5288 	if (err) {
5289 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5290 			 err);
5291 		goto failed_mount5;
5292 	}
5293 
5294 	/*
5295 	 * We can only set up the journal commit callback once
5296 	 * mballoc is initialized
5297 	 */
5298 	if (sbi->s_journal)
5299 		sbi->s_journal->j_commit_callback =
5300 			ext4_journal_commit_callback;
5301 
5302 	block = ext4_count_free_clusters(sb);
5303 	ext4_free_blocks_count_set(sbi->s_es,
5304 				   EXT4_C2B(sbi, block));
5305 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5306 				  GFP_KERNEL);
5307 	if (!err) {
5308 		unsigned long freei = ext4_count_free_inodes(sb);
5309 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5310 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5311 					  GFP_KERNEL);
5312 	}
5313 	if (!err)
5314 		err = percpu_counter_init(&sbi->s_dirs_counter,
5315 					  ext4_count_dirs(sb), GFP_KERNEL);
5316 	if (!err)
5317 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5318 					  GFP_KERNEL);
5319 	if (!err)
5320 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5321 					  GFP_KERNEL);
5322 	if (!err)
5323 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5324 
5325 	if (err) {
5326 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5327 		goto failed_mount6;
5328 	}
5329 
5330 	if (ext4_has_feature_flex_bg(sb))
5331 		if (!ext4_fill_flex_info(sb)) {
5332 			ext4_msg(sb, KERN_ERR,
5333 			       "unable to initialize "
5334 			       "flex_bg meta info!");
5335 			ret = -ENOMEM;
5336 			goto failed_mount6;
5337 		}
5338 
5339 	err = ext4_register_li_request(sb, first_not_zeroed);
5340 	if (err)
5341 		goto failed_mount6;
5342 
5343 	err = ext4_register_sysfs(sb);
5344 	if (err)
5345 		goto failed_mount7;
5346 
5347 	err = ext4_init_orphan_info(sb);
5348 	if (err)
5349 		goto failed_mount8;
5350 #ifdef CONFIG_QUOTA
5351 	/* Enable quota usage during mount. */
5352 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5353 		err = ext4_enable_quotas(sb);
5354 		if (err)
5355 			goto failed_mount9;
5356 	}
5357 #endif  /* CONFIG_QUOTA */
5358 
5359 	/*
5360 	 * Save the original bdev mapping's wb_err value which could be
5361 	 * used to detect the metadata async write error.
5362 	 */
5363 	spin_lock_init(&sbi->s_bdev_wb_lock);
5364 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5365 				 &sbi->s_bdev_wb_err);
5366 	sb->s_bdev->bd_super = sb;
5367 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5368 	ext4_orphan_cleanup(sb, es);
5369 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5370 	/*
5371 	 * Update the checksum after updating free space/inode counters and
5372 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5373 	 * checksum in the buffer cache until it is written out and
5374 	 * e2fsprogs programs trying to open a file system immediately
5375 	 * after it is mounted can fail.
5376 	 */
5377 	ext4_superblock_csum_set(sb);
5378 	if (needs_recovery) {
5379 		ext4_msg(sb, KERN_INFO, "recovery complete");
5380 		err = ext4_mark_recovery_complete(sb, es);
5381 		if (err)
5382 			goto failed_mount9;
5383 	}
5384 
5385 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5386 		ext4_msg(sb, KERN_WARNING,
5387 			 "mounting with \"discard\" option, but the device does not support discard");
5388 
5389 	if (es->s_error_count)
5390 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5391 
5392 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5393 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5394 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5395 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5396 	atomic_set(&sbi->s_warning_count, 0);
5397 	atomic_set(&sbi->s_msg_count, 0);
5398 
5399 	return 0;
5400 
5401 cantfind_ext4:
5402 	if (!silent)
5403 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5404 	goto failed_mount;
5405 
5406 failed_mount9:
5407 	ext4_release_orphan_info(sb);
5408 failed_mount8:
5409 	ext4_unregister_sysfs(sb);
5410 	kobject_put(&sbi->s_kobj);
5411 failed_mount7:
5412 	ext4_unregister_li_request(sb);
5413 failed_mount6:
5414 	ext4_mb_release(sb);
5415 	rcu_read_lock();
5416 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5417 	if (flex_groups) {
5418 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5419 			kvfree(flex_groups[i]);
5420 		kvfree(flex_groups);
5421 	}
5422 	rcu_read_unlock();
5423 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5424 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5425 	percpu_counter_destroy(&sbi->s_dirs_counter);
5426 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5427 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5428 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5429 failed_mount5:
5430 	ext4_ext_release(sb);
5431 	ext4_release_system_zone(sb);
5432 failed_mount4a:
5433 	dput(sb->s_root);
5434 	sb->s_root = NULL;
5435 failed_mount4:
5436 	ext4_msg(sb, KERN_ERR, "mount failed");
5437 	if (EXT4_SB(sb)->rsv_conversion_wq)
5438 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5439 failed_mount_wq:
5440 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5441 	sbi->s_ea_inode_cache = NULL;
5442 
5443 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5444 	sbi->s_ea_block_cache = NULL;
5445 
5446 	if (sbi->s_journal) {
5447 		/* flush s_error_work before journal destroy. */
5448 		flush_work(&sbi->s_error_work);
5449 		jbd2_journal_destroy(sbi->s_journal);
5450 		sbi->s_journal = NULL;
5451 	}
5452 failed_mount3a:
5453 	ext4_es_unregister_shrinker(sbi);
5454 failed_mount3:
5455 	/* flush s_error_work before sbi destroy */
5456 	flush_work(&sbi->s_error_work);
5457 	del_timer_sync(&sbi->s_err_report);
5458 	ext4_stop_mmpd(sbi);
5459 failed_mount2:
5460 	rcu_read_lock();
5461 	group_desc = rcu_dereference(sbi->s_group_desc);
5462 	for (i = 0; i < db_count; i++)
5463 		brelse(group_desc[i]);
5464 	kvfree(group_desc);
5465 	rcu_read_unlock();
5466 failed_mount:
5467 	if (sbi->s_chksum_driver)
5468 		crypto_free_shash(sbi->s_chksum_driver);
5469 
5470 #if IS_ENABLED(CONFIG_UNICODE)
5471 	utf8_unload(sb->s_encoding);
5472 #endif
5473 
5474 #ifdef CONFIG_QUOTA
5475 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5476 		kfree(get_qf_name(sb, sbi, i));
5477 #endif
5478 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5479 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5480 	brelse(bh);
5481 	ext4_blkdev_remove(sbi);
5482 out_fail:
5483 	sb->s_fs_info = NULL;
5484 	return err ? err : ret;
5485 }
5486 
5487 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5488 {
5489 	struct ext4_fs_context *ctx = fc->fs_private;
5490 	struct ext4_sb_info *sbi;
5491 	const char *descr;
5492 	int ret;
5493 
5494 	sbi = ext4_alloc_sbi(sb);
5495 	if (!sbi)
5496 		return -ENOMEM;
5497 
5498 	fc->s_fs_info = sbi;
5499 
5500 	/* Cleanup superblock name */
5501 	strreplace(sb->s_id, '/', '!');
5502 
5503 	sbi->s_sb_block = 1;	/* Default super block location */
5504 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5505 		sbi->s_sb_block = ctx->s_sb_block;
5506 
5507 	ret = __ext4_fill_super(fc, sb);
5508 	if (ret < 0)
5509 		goto free_sbi;
5510 
5511 	if (sbi->s_journal) {
5512 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5513 			descr = " journalled data mode";
5514 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5515 			descr = " ordered data mode";
5516 		else
5517 			descr = " writeback data mode";
5518 	} else
5519 		descr = "out journal";
5520 
5521 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5522 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5523 			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
5524 
5525 	/* Update the s_overhead_clusters if necessary */
5526 	ext4_update_overhead(sb);
5527 	return 0;
5528 
5529 free_sbi:
5530 	ext4_free_sbi(sbi);
5531 	fc->s_fs_info = NULL;
5532 	return ret;
5533 }
5534 
5535 static int ext4_get_tree(struct fs_context *fc)
5536 {
5537 	return get_tree_bdev(fc, ext4_fill_super);
5538 }
5539 
5540 /*
5541  * Setup any per-fs journal parameters now.  We'll do this both on
5542  * initial mount, once the journal has been initialised but before we've
5543  * done any recovery; and again on any subsequent remount.
5544  */
5545 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5546 {
5547 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5548 
5549 	journal->j_commit_interval = sbi->s_commit_interval;
5550 	journal->j_min_batch_time = sbi->s_min_batch_time;
5551 	journal->j_max_batch_time = sbi->s_max_batch_time;
5552 	ext4_fc_init(sb, journal);
5553 
5554 	write_lock(&journal->j_state_lock);
5555 	if (test_opt(sb, BARRIER))
5556 		journal->j_flags |= JBD2_BARRIER;
5557 	else
5558 		journal->j_flags &= ~JBD2_BARRIER;
5559 	if (test_opt(sb, DATA_ERR_ABORT))
5560 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5561 	else
5562 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5563 	write_unlock(&journal->j_state_lock);
5564 }
5565 
5566 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5567 					     unsigned int journal_inum)
5568 {
5569 	struct inode *journal_inode;
5570 
5571 	/*
5572 	 * Test for the existence of a valid inode on disk.  Bad things
5573 	 * happen if we iget() an unused inode, as the subsequent iput()
5574 	 * will try to delete it.
5575 	 */
5576 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5577 	if (IS_ERR(journal_inode)) {
5578 		ext4_msg(sb, KERN_ERR, "no journal found");
5579 		return NULL;
5580 	}
5581 	if (!journal_inode->i_nlink) {
5582 		make_bad_inode(journal_inode);
5583 		iput(journal_inode);
5584 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5585 		return NULL;
5586 	}
5587 
5588 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5589 		  journal_inode, journal_inode->i_size);
5590 	if (!S_ISREG(journal_inode->i_mode)) {
5591 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5592 		iput(journal_inode);
5593 		return NULL;
5594 	}
5595 	return journal_inode;
5596 }
5597 
5598 static journal_t *ext4_get_journal(struct super_block *sb,
5599 				   unsigned int journal_inum)
5600 {
5601 	struct inode *journal_inode;
5602 	journal_t *journal;
5603 
5604 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5605 		return NULL;
5606 
5607 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5608 	if (!journal_inode)
5609 		return NULL;
5610 
5611 	journal = jbd2_journal_init_inode(journal_inode);
5612 	if (!journal) {
5613 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5614 		iput(journal_inode);
5615 		return NULL;
5616 	}
5617 	journal->j_private = sb;
5618 	ext4_init_journal_params(sb, journal);
5619 	return journal;
5620 }
5621 
5622 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5623 				       dev_t j_dev)
5624 {
5625 	struct buffer_head *bh;
5626 	journal_t *journal;
5627 	ext4_fsblk_t start;
5628 	ext4_fsblk_t len;
5629 	int hblock, blocksize;
5630 	ext4_fsblk_t sb_block;
5631 	unsigned long offset;
5632 	struct ext4_super_block *es;
5633 	struct block_device *bdev;
5634 
5635 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5636 		return NULL;
5637 
5638 	bdev = ext4_blkdev_get(j_dev, sb);
5639 	if (bdev == NULL)
5640 		return NULL;
5641 
5642 	blocksize = sb->s_blocksize;
5643 	hblock = bdev_logical_block_size(bdev);
5644 	if (blocksize < hblock) {
5645 		ext4_msg(sb, KERN_ERR,
5646 			"blocksize too small for journal device");
5647 		goto out_bdev;
5648 	}
5649 
5650 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5651 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5652 	set_blocksize(bdev, blocksize);
5653 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5654 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5655 		       "external journal");
5656 		goto out_bdev;
5657 	}
5658 
5659 	es = (struct ext4_super_block *) (bh->b_data + offset);
5660 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5661 	    !(le32_to_cpu(es->s_feature_incompat) &
5662 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5663 		ext4_msg(sb, KERN_ERR, "external journal has "
5664 					"bad superblock");
5665 		brelse(bh);
5666 		goto out_bdev;
5667 	}
5668 
5669 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5670 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5671 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5672 		ext4_msg(sb, KERN_ERR, "external journal has "
5673 				       "corrupt superblock");
5674 		brelse(bh);
5675 		goto out_bdev;
5676 	}
5677 
5678 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5679 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5680 		brelse(bh);
5681 		goto out_bdev;
5682 	}
5683 
5684 	len = ext4_blocks_count(es);
5685 	start = sb_block + 1;
5686 	brelse(bh);	/* we're done with the superblock */
5687 
5688 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5689 					start, len, blocksize);
5690 	if (!journal) {
5691 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5692 		goto out_bdev;
5693 	}
5694 	journal->j_private = sb;
5695 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5696 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5697 		goto out_journal;
5698 	}
5699 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5700 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5701 					"user (unsupported) - %d",
5702 			be32_to_cpu(journal->j_superblock->s_nr_users));
5703 		goto out_journal;
5704 	}
5705 	EXT4_SB(sb)->s_journal_bdev = bdev;
5706 	ext4_init_journal_params(sb, journal);
5707 	return journal;
5708 
5709 out_journal:
5710 	jbd2_journal_destroy(journal);
5711 out_bdev:
5712 	ext4_blkdev_put(bdev);
5713 	return NULL;
5714 }
5715 
5716 static int ext4_load_journal(struct super_block *sb,
5717 			     struct ext4_super_block *es,
5718 			     unsigned long journal_devnum)
5719 {
5720 	journal_t *journal;
5721 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5722 	dev_t journal_dev;
5723 	int err = 0;
5724 	int really_read_only;
5725 	int journal_dev_ro;
5726 
5727 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5728 		return -EFSCORRUPTED;
5729 
5730 	if (journal_devnum &&
5731 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5732 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5733 			"numbers have changed");
5734 		journal_dev = new_decode_dev(journal_devnum);
5735 	} else
5736 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5737 
5738 	if (journal_inum && journal_dev) {
5739 		ext4_msg(sb, KERN_ERR,
5740 			 "filesystem has both journal inode and journal device!");
5741 		return -EINVAL;
5742 	}
5743 
5744 	if (journal_inum) {
5745 		journal = ext4_get_journal(sb, journal_inum);
5746 		if (!journal)
5747 			return -EINVAL;
5748 	} else {
5749 		journal = ext4_get_dev_journal(sb, journal_dev);
5750 		if (!journal)
5751 			return -EINVAL;
5752 	}
5753 
5754 	journal_dev_ro = bdev_read_only(journal->j_dev);
5755 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5756 
5757 	if (journal_dev_ro && !sb_rdonly(sb)) {
5758 		ext4_msg(sb, KERN_ERR,
5759 			 "journal device read-only, try mounting with '-o ro'");
5760 		err = -EROFS;
5761 		goto err_out;
5762 	}
5763 
5764 	/*
5765 	 * Are we loading a blank journal or performing recovery after a
5766 	 * crash?  For recovery, we need to check in advance whether we
5767 	 * can get read-write access to the device.
5768 	 */
5769 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5770 		if (sb_rdonly(sb)) {
5771 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5772 					"required on readonly filesystem");
5773 			if (really_read_only) {
5774 				ext4_msg(sb, KERN_ERR, "write access "
5775 					"unavailable, cannot proceed "
5776 					"(try mounting with noload)");
5777 				err = -EROFS;
5778 				goto err_out;
5779 			}
5780 			ext4_msg(sb, KERN_INFO, "write access will "
5781 			       "be enabled during recovery");
5782 		}
5783 	}
5784 
5785 	if (!(journal->j_flags & JBD2_BARRIER))
5786 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5787 
5788 	if (!ext4_has_feature_journal_needs_recovery(sb))
5789 		err = jbd2_journal_wipe(journal, !really_read_only);
5790 	if (!err) {
5791 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5792 		if (save)
5793 			memcpy(save, ((char *) es) +
5794 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5795 		err = jbd2_journal_load(journal);
5796 		if (save)
5797 			memcpy(((char *) es) + EXT4_S_ERR_START,
5798 			       save, EXT4_S_ERR_LEN);
5799 		kfree(save);
5800 	}
5801 
5802 	if (err) {
5803 		ext4_msg(sb, KERN_ERR, "error loading journal");
5804 		goto err_out;
5805 	}
5806 
5807 	EXT4_SB(sb)->s_journal = journal;
5808 	err = ext4_clear_journal_err(sb, es);
5809 	if (err) {
5810 		EXT4_SB(sb)->s_journal = NULL;
5811 		jbd2_journal_destroy(journal);
5812 		return err;
5813 	}
5814 
5815 	if (!really_read_only && journal_devnum &&
5816 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5817 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5818 
5819 		/* Make sure we flush the recovery flag to disk. */
5820 		ext4_commit_super(sb);
5821 	}
5822 
5823 	return 0;
5824 
5825 err_out:
5826 	jbd2_journal_destroy(journal);
5827 	return err;
5828 }
5829 
5830 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5831 static void ext4_update_super(struct super_block *sb)
5832 {
5833 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5834 	struct ext4_super_block *es = sbi->s_es;
5835 	struct buffer_head *sbh = sbi->s_sbh;
5836 
5837 	lock_buffer(sbh);
5838 	/*
5839 	 * If the file system is mounted read-only, don't update the
5840 	 * superblock write time.  This avoids updating the superblock
5841 	 * write time when we are mounting the root file system
5842 	 * read/only but we need to replay the journal; at that point,
5843 	 * for people who are east of GMT and who make their clock
5844 	 * tick in localtime for Windows bug-for-bug compatibility,
5845 	 * the clock is set in the future, and this will cause e2fsck
5846 	 * to complain and force a full file system check.
5847 	 */
5848 	if (!(sb->s_flags & SB_RDONLY))
5849 		ext4_update_tstamp(es, s_wtime);
5850 	es->s_kbytes_written =
5851 		cpu_to_le64(sbi->s_kbytes_written +
5852 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5853 		      sbi->s_sectors_written_start) >> 1));
5854 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5855 		ext4_free_blocks_count_set(es,
5856 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5857 				&sbi->s_freeclusters_counter)));
5858 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5859 		es->s_free_inodes_count =
5860 			cpu_to_le32(percpu_counter_sum_positive(
5861 				&sbi->s_freeinodes_counter));
5862 	/* Copy error information to the on-disk superblock */
5863 	spin_lock(&sbi->s_error_lock);
5864 	if (sbi->s_add_error_count > 0) {
5865 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5866 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5867 			__ext4_update_tstamp(&es->s_first_error_time,
5868 					     &es->s_first_error_time_hi,
5869 					     sbi->s_first_error_time);
5870 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5871 				sizeof(es->s_first_error_func));
5872 			es->s_first_error_line =
5873 				cpu_to_le32(sbi->s_first_error_line);
5874 			es->s_first_error_ino =
5875 				cpu_to_le32(sbi->s_first_error_ino);
5876 			es->s_first_error_block =
5877 				cpu_to_le64(sbi->s_first_error_block);
5878 			es->s_first_error_errcode =
5879 				ext4_errno_to_code(sbi->s_first_error_code);
5880 		}
5881 		__ext4_update_tstamp(&es->s_last_error_time,
5882 				     &es->s_last_error_time_hi,
5883 				     sbi->s_last_error_time);
5884 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5885 			sizeof(es->s_last_error_func));
5886 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5887 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5888 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5889 		es->s_last_error_errcode =
5890 				ext4_errno_to_code(sbi->s_last_error_code);
5891 		/*
5892 		 * Start the daily error reporting function if it hasn't been
5893 		 * started already
5894 		 */
5895 		if (!es->s_error_count)
5896 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5897 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5898 		sbi->s_add_error_count = 0;
5899 	}
5900 	spin_unlock(&sbi->s_error_lock);
5901 
5902 	ext4_superblock_csum_set(sb);
5903 	unlock_buffer(sbh);
5904 }
5905 
5906 static int ext4_commit_super(struct super_block *sb)
5907 {
5908 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5909 
5910 	if (!sbh)
5911 		return -EINVAL;
5912 	if (block_device_ejected(sb))
5913 		return -ENODEV;
5914 
5915 	ext4_update_super(sb);
5916 
5917 	lock_buffer(sbh);
5918 	/* Buffer got discarded which means block device got invalidated */
5919 	if (!buffer_mapped(sbh)) {
5920 		unlock_buffer(sbh);
5921 		return -EIO;
5922 	}
5923 
5924 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5925 		/*
5926 		 * Oh, dear.  A previous attempt to write the
5927 		 * superblock failed.  This could happen because the
5928 		 * USB device was yanked out.  Or it could happen to
5929 		 * be a transient write error and maybe the block will
5930 		 * be remapped.  Nothing we can do but to retry the
5931 		 * write and hope for the best.
5932 		 */
5933 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5934 		       "superblock detected");
5935 		clear_buffer_write_io_error(sbh);
5936 		set_buffer_uptodate(sbh);
5937 	}
5938 	get_bh(sbh);
5939 	/* Clear potential dirty bit if it was journalled update */
5940 	clear_buffer_dirty(sbh);
5941 	sbh->b_end_io = end_buffer_write_sync;
5942 	submit_bh(REQ_OP_WRITE,
5943 		  REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
5944 	wait_on_buffer(sbh);
5945 	if (buffer_write_io_error(sbh)) {
5946 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
5947 		       "superblock");
5948 		clear_buffer_write_io_error(sbh);
5949 		set_buffer_uptodate(sbh);
5950 		return -EIO;
5951 	}
5952 	return 0;
5953 }
5954 
5955 /*
5956  * Have we just finished recovery?  If so, and if we are mounting (or
5957  * remounting) the filesystem readonly, then we will end up with a
5958  * consistent fs on disk.  Record that fact.
5959  */
5960 static int ext4_mark_recovery_complete(struct super_block *sb,
5961 				       struct ext4_super_block *es)
5962 {
5963 	int err;
5964 	journal_t *journal = EXT4_SB(sb)->s_journal;
5965 
5966 	if (!ext4_has_feature_journal(sb)) {
5967 		if (journal != NULL) {
5968 			ext4_error(sb, "Journal got removed while the fs was "
5969 				   "mounted!");
5970 			return -EFSCORRUPTED;
5971 		}
5972 		return 0;
5973 	}
5974 	jbd2_journal_lock_updates(journal);
5975 	err = jbd2_journal_flush(journal, 0);
5976 	if (err < 0)
5977 		goto out;
5978 
5979 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
5980 	    ext4_has_feature_orphan_present(sb))) {
5981 		if (!ext4_orphan_file_empty(sb)) {
5982 			ext4_error(sb, "Orphan file not empty on read-only fs.");
5983 			err = -EFSCORRUPTED;
5984 			goto out;
5985 		}
5986 		ext4_clear_feature_journal_needs_recovery(sb);
5987 		ext4_clear_feature_orphan_present(sb);
5988 		ext4_commit_super(sb);
5989 	}
5990 out:
5991 	jbd2_journal_unlock_updates(journal);
5992 	return err;
5993 }
5994 
5995 /*
5996  * If we are mounting (or read-write remounting) a filesystem whose journal
5997  * has recorded an error from a previous lifetime, move that error to the
5998  * main filesystem now.
5999  */
6000 static int ext4_clear_journal_err(struct super_block *sb,
6001 				   struct ext4_super_block *es)
6002 {
6003 	journal_t *journal;
6004 	int j_errno;
6005 	const char *errstr;
6006 
6007 	if (!ext4_has_feature_journal(sb)) {
6008 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6009 		return -EFSCORRUPTED;
6010 	}
6011 
6012 	journal = EXT4_SB(sb)->s_journal;
6013 
6014 	/*
6015 	 * Now check for any error status which may have been recorded in the
6016 	 * journal by a prior ext4_error() or ext4_abort()
6017 	 */
6018 
6019 	j_errno = jbd2_journal_errno(journal);
6020 	if (j_errno) {
6021 		char nbuf[16];
6022 
6023 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6024 		ext4_warning(sb, "Filesystem error recorded "
6025 			     "from previous mount: %s", errstr);
6026 		ext4_warning(sb, "Marking fs in need of filesystem check.");
6027 
6028 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6029 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6030 		ext4_commit_super(sb);
6031 
6032 		jbd2_journal_clear_err(journal);
6033 		jbd2_journal_update_sb_errno(journal);
6034 	}
6035 	return 0;
6036 }
6037 
6038 /*
6039  * Force the running and committing transactions to commit,
6040  * and wait on the commit.
6041  */
6042 int ext4_force_commit(struct super_block *sb)
6043 {
6044 	journal_t *journal;
6045 
6046 	if (sb_rdonly(sb))
6047 		return 0;
6048 
6049 	journal = EXT4_SB(sb)->s_journal;
6050 	return ext4_journal_force_commit(journal);
6051 }
6052 
6053 static int ext4_sync_fs(struct super_block *sb, int wait)
6054 {
6055 	int ret = 0;
6056 	tid_t target;
6057 	bool needs_barrier = false;
6058 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6059 
6060 	if (unlikely(ext4_forced_shutdown(sbi)))
6061 		return 0;
6062 
6063 	trace_ext4_sync_fs(sb, wait);
6064 	flush_workqueue(sbi->rsv_conversion_wq);
6065 	/*
6066 	 * Writeback quota in non-journalled quota case - journalled quota has
6067 	 * no dirty dquots
6068 	 */
6069 	dquot_writeback_dquots(sb, -1);
6070 	/*
6071 	 * Data writeback is possible w/o journal transaction, so barrier must
6072 	 * being sent at the end of the function. But we can skip it if
6073 	 * transaction_commit will do it for us.
6074 	 */
6075 	if (sbi->s_journal) {
6076 		target = jbd2_get_latest_transaction(sbi->s_journal);
6077 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6078 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6079 			needs_barrier = true;
6080 
6081 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6082 			if (wait)
6083 				ret = jbd2_log_wait_commit(sbi->s_journal,
6084 							   target);
6085 		}
6086 	} else if (wait && test_opt(sb, BARRIER))
6087 		needs_barrier = true;
6088 	if (needs_barrier) {
6089 		int err;
6090 		err = blkdev_issue_flush(sb->s_bdev);
6091 		if (!ret)
6092 			ret = err;
6093 	}
6094 
6095 	return ret;
6096 }
6097 
6098 /*
6099  * LVM calls this function before a (read-only) snapshot is created.  This
6100  * gives us a chance to flush the journal completely and mark the fs clean.
6101  *
6102  * Note that only this function cannot bring a filesystem to be in a clean
6103  * state independently. It relies on upper layer to stop all data & metadata
6104  * modifications.
6105  */
6106 static int ext4_freeze(struct super_block *sb)
6107 {
6108 	int error = 0;
6109 	journal_t *journal;
6110 
6111 	if (sb_rdonly(sb))
6112 		return 0;
6113 
6114 	journal = EXT4_SB(sb)->s_journal;
6115 
6116 	if (journal) {
6117 		/* Now we set up the journal barrier. */
6118 		jbd2_journal_lock_updates(journal);
6119 
6120 		/*
6121 		 * Don't clear the needs_recovery flag if we failed to
6122 		 * flush the journal.
6123 		 */
6124 		error = jbd2_journal_flush(journal, 0);
6125 		if (error < 0)
6126 			goto out;
6127 
6128 		/* Journal blocked and flushed, clear needs_recovery flag. */
6129 		ext4_clear_feature_journal_needs_recovery(sb);
6130 		if (ext4_orphan_file_empty(sb))
6131 			ext4_clear_feature_orphan_present(sb);
6132 	}
6133 
6134 	error = ext4_commit_super(sb);
6135 out:
6136 	if (journal)
6137 		/* we rely on upper layer to stop further updates */
6138 		jbd2_journal_unlock_updates(journal);
6139 	return error;
6140 }
6141 
6142 /*
6143  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6144  * flag here, even though the filesystem is not technically dirty yet.
6145  */
6146 static int ext4_unfreeze(struct super_block *sb)
6147 {
6148 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6149 		return 0;
6150 
6151 	if (EXT4_SB(sb)->s_journal) {
6152 		/* Reset the needs_recovery flag before the fs is unlocked. */
6153 		ext4_set_feature_journal_needs_recovery(sb);
6154 		if (ext4_has_feature_orphan_file(sb))
6155 			ext4_set_feature_orphan_present(sb);
6156 	}
6157 
6158 	ext4_commit_super(sb);
6159 	return 0;
6160 }
6161 
6162 /*
6163  * Structure to save mount options for ext4_remount's benefit
6164  */
6165 struct ext4_mount_options {
6166 	unsigned long s_mount_opt;
6167 	unsigned long s_mount_opt2;
6168 	kuid_t s_resuid;
6169 	kgid_t s_resgid;
6170 	unsigned long s_commit_interval;
6171 	u32 s_min_batch_time, s_max_batch_time;
6172 #ifdef CONFIG_QUOTA
6173 	int s_jquota_fmt;
6174 	char *s_qf_names[EXT4_MAXQUOTAS];
6175 #endif
6176 };
6177 
6178 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6179 {
6180 	struct ext4_fs_context *ctx = fc->fs_private;
6181 	struct ext4_super_block *es;
6182 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6183 	unsigned long old_sb_flags;
6184 	struct ext4_mount_options old_opts;
6185 	ext4_group_t g;
6186 	int err = 0;
6187 #ifdef CONFIG_QUOTA
6188 	int enable_quota = 0;
6189 	int i, j;
6190 	char *to_free[EXT4_MAXQUOTAS];
6191 #endif
6192 
6193 
6194 	/* Store the original options */
6195 	old_sb_flags = sb->s_flags;
6196 	old_opts.s_mount_opt = sbi->s_mount_opt;
6197 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6198 	old_opts.s_resuid = sbi->s_resuid;
6199 	old_opts.s_resgid = sbi->s_resgid;
6200 	old_opts.s_commit_interval = sbi->s_commit_interval;
6201 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6202 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6203 #ifdef CONFIG_QUOTA
6204 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6205 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6206 		if (sbi->s_qf_names[i]) {
6207 			char *qf_name = get_qf_name(sb, sbi, i);
6208 
6209 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6210 			if (!old_opts.s_qf_names[i]) {
6211 				for (j = 0; j < i; j++)
6212 					kfree(old_opts.s_qf_names[j]);
6213 				return -ENOMEM;
6214 			}
6215 		} else
6216 			old_opts.s_qf_names[i] = NULL;
6217 #endif
6218 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6219 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6220 			ctx->journal_ioprio =
6221 				sbi->s_journal->j_task->io_context->ioprio;
6222 		else
6223 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6224 
6225 	}
6226 
6227 	ext4_apply_options(fc, sb);
6228 
6229 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6230 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6231 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6232 			 "during remount not supported; ignoring");
6233 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6234 	}
6235 
6236 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6237 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6238 			ext4_msg(sb, KERN_ERR, "can't mount with "
6239 				 "both data=journal and delalloc");
6240 			err = -EINVAL;
6241 			goto restore_opts;
6242 		}
6243 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6244 			ext4_msg(sb, KERN_ERR, "can't mount with "
6245 				 "both data=journal and dioread_nolock");
6246 			err = -EINVAL;
6247 			goto restore_opts;
6248 		}
6249 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6250 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6251 			ext4_msg(sb, KERN_ERR, "can't mount with "
6252 				"journal_async_commit in data=ordered mode");
6253 			err = -EINVAL;
6254 			goto restore_opts;
6255 		}
6256 	}
6257 
6258 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6259 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6260 		err = -EINVAL;
6261 		goto restore_opts;
6262 	}
6263 
6264 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6265 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6266 
6267 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6268 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6269 
6270 	es = sbi->s_es;
6271 
6272 	if (sbi->s_journal) {
6273 		ext4_init_journal_params(sb, sbi->s_journal);
6274 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6275 	}
6276 
6277 	/* Flush outstanding errors before changing fs state */
6278 	flush_work(&sbi->s_error_work);
6279 
6280 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6281 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6282 			err = -EROFS;
6283 			goto restore_opts;
6284 		}
6285 
6286 		if (fc->sb_flags & SB_RDONLY) {
6287 			err = sync_filesystem(sb);
6288 			if (err < 0)
6289 				goto restore_opts;
6290 			err = dquot_suspend(sb, -1);
6291 			if (err < 0)
6292 				goto restore_opts;
6293 
6294 			/*
6295 			 * First of all, the unconditional stuff we have to do
6296 			 * to disable replay of the journal when we next remount
6297 			 */
6298 			sb->s_flags |= SB_RDONLY;
6299 
6300 			/*
6301 			 * OK, test if we are remounting a valid rw partition
6302 			 * readonly, and if so set the rdonly flag and then
6303 			 * mark the partition as valid again.
6304 			 */
6305 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6306 			    (sbi->s_mount_state & EXT4_VALID_FS))
6307 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6308 
6309 			if (sbi->s_journal) {
6310 				/*
6311 				 * We let remount-ro finish even if marking fs
6312 				 * as clean failed...
6313 				 */
6314 				ext4_mark_recovery_complete(sb, es);
6315 			}
6316 		} else {
6317 			/* Make sure we can mount this feature set readwrite */
6318 			if (ext4_has_feature_readonly(sb) ||
6319 			    !ext4_feature_set_ok(sb, 0)) {
6320 				err = -EROFS;
6321 				goto restore_opts;
6322 			}
6323 			/*
6324 			 * Make sure the group descriptor checksums
6325 			 * are sane.  If they aren't, refuse to remount r/w.
6326 			 */
6327 			for (g = 0; g < sbi->s_groups_count; g++) {
6328 				struct ext4_group_desc *gdp =
6329 					ext4_get_group_desc(sb, g, NULL);
6330 
6331 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6332 					ext4_msg(sb, KERN_ERR,
6333 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6334 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6335 					       le16_to_cpu(gdp->bg_checksum));
6336 					err = -EFSBADCRC;
6337 					goto restore_opts;
6338 				}
6339 			}
6340 
6341 			/*
6342 			 * If we have an unprocessed orphan list hanging
6343 			 * around from a previously readonly bdev mount,
6344 			 * require a full umount/remount for now.
6345 			 */
6346 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6347 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6348 				       "remount RDWR because of unprocessed "
6349 				       "orphan inode list.  Please "
6350 				       "umount/remount instead");
6351 				err = -EINVAL;
6352 				goto restore_opts;
6353 			}
6354 
6355 			/*
6356 			 * Mounting a RDONLY partition read-write, so reread
6357 			 * and store the current valid flag.  (It may have
6358 			 * been changed by e2fsck since we originally mounted
6359 			 * the partition.)
6360 			 */
6361 			if (sbi->s_journal) {
6362 				err = ext4_clear_journal_err(sb, es);
6363 				if (err)
6364 					goto restore_opts;
6365 			}
6366 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6367 					      ~EXT4_FC_REPLAY);
6368 
6369 			err = ext4_setup_super(sb, es, 0);
6370 			if (err)
6371 				goto restore_opts;
6372 
6373 			sb->s_flags &= ~SB_RDONLY;
6374 			if (ext4_has_feature_mmp(sb))
6375 				if (ext4_multi_mount_protect(sb,
6376 						le64_to_cpu(es->s_mmp_block))) {
6377 					err = -EROFS;
6378 					goto restore_opts;
6379 				}
6380 #ifdef CONFIG_QUOTA
6381 			enable_quota = 1;
6382 #endif
6383 		}
6384 	}
6385 
6386 	/*
6387 	 * Reinitialize lazy itable initialization thread based on
6388 	 * current settings
6389 	 */
6390 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6391 		ext4_unregister_li_request(sb);
6392 	else {
6393 		ext4_group_t first_not_zeroed;
6394 		first_not_zeroed = ext4_has_uninit_itable(sb);
6395 		ext4_register_li_request(sb, first_not_zeroed);
6396 	}
6397 
6398 	/*
6399 	 * Handle creation of system zone data early because it can fail.
6400 	 * Releasing of existing data is done when we are sure remount will
6401 	 * succeed.
6402 	 */
6403 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6404 		err = ext4_setup_system_zone(sb);
6405 		if (err)
6406 			goto restore_opts;
6407 	}
6408 
6409 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6410 		err = ext4_commit_super(sb);
6411 		if (err)
6412 			goto restore_opts;
6413 	}
6414 
6415 #ifdef CONFIG_QUOTA
6416 	/* Release old quota file names */
6417 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6418 		kfree(old_opts.s_qf_names[i]);
6419 	if (enable_quota) {
6420 		if (sb_any_quota_suspended(sb))
6421 			dquot_resume(sb, -1);
6422 		else if (ext4_has_feature_quota(sb)) {
6423 			err = ext4_enable_quotas(sb);
6424 			if (err)
6425 				goto restore_opts;
6426 		}
6427 	}
6428 #endif
6429 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6430 		ext4_release_system_zone(sb);
6431 
6432 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6433 		ext4_stop_mmpd(sbi);
6434 
6435 	return 0;
6436 
6437 restore_opts:
6438 	sb->s_flags = old_sb_flags;
6439 	sbi->s_mount_opt = old_opts.s_mount_opt;
6440 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6441 	sbi->s_resuid = old_opts.s_resuid;
6442 	sbi->s_resgid = old_opts.s_resgid;
6443 	sbi->s_commit_interval = old_opts.s_commit_interval;
6444 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6445 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6446 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6447 		ext4_release_system_zone(sb);
6448 #ifdef CONFIG_QUOTA
6449 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6450 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6451 		to_free[i] = get_qf_name(sb, sbi, i);
6452 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6453 	}
6454 	synchronize_rcu();
6455 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6456 		kfree(to_free[i]);
6457 #endif
6458 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6459 		ext4_stop_mmpd(sbi);
6460 	return err;
6461 }
6462 
6463 static int ext4_reconfigure(struct fs_context *fc)
6464 {
6465 	struct super_block *sb = fc->root->d_sb;
6466 	int ret;
6467 
6468 	fc->s_fs_info = EXT4_SB(sb);
6469 
6470 	ret = ext4_check_opt_consistency(fc, sb);
6471 	if (ret < 0)
6472 		return ret;
6473 
6474 	ret = __ext4_remount(fc, sb);
6475 	if (ret < 0)
6476 		return ret;
6477 
6478 	ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6479 		 ext4_quota_mode(sb));
6480 
6481 	return 0;
6482 }
6483 
6484 #ifdef CONFIG_QUOTA
6485 static int ext4_statfs_project(struct super_block *sb,
6486 			       kprojid_t projid, struct kstatfs *buf)
6487 {
6488 	struct kqid qid;
6489 	struct dquot *dquot;
6490 	u64 limit;
6491 	u64 curblock;
6492 
6493 	qid = make_kqid_projid(projid);
6494 	dquot = dqget(sb, qid);
6495 	if (IS_ERR(dquot))
6496 		return PTR_ERR(dquot);
6497 	spin_lock(&dquot->dq_dqb_lock);
6498 
6499 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6500 			     dquot->dq_dqb.dqb_bhardlimit);
6501 	limit >>= sb->s_blocksize_bits;
6502 
6503 	if (limit && buf->f_blocks > limit) {
6504 		curblock = (dquot->dq_dqb.dqb_curspace +
6505 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6506 		buf->f_blocks = limit;
6507 		buf->f_bfree = buf->f_bavail =
6508 			(buf->f_blocks > curblock) ?
6509 			 (buf->f_blocks - curblock) : 0;
6510 	}
6511 
6512 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6513 			     dquot->dq_dqb.dqb_ihardlimit);
6514 	if (limit && buf->f_files > limit) {
6515 		buf->f_files = limit;
6516 		buf->f_ffree =
6517 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6518 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6519 	}
6520 
6521 	spin_unlock(&dquot->dq_dqb_lock);
6522 	dqput(dquot);
6523 	return 0;
6524 }
6525 #endif
6526 
6527 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6528 {
6529 	struct super_block *sb = dentry->d_sb;
6530 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6531 	struct ext4_super_block *es = sbi->s_es;
6532 	ext4_fsblk_t overhead = 0, resv_blocks;
6533 	s64 bfree;
6534 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6535 
6536 	if (!test_opt(sb, MINIX_DF))
6537 		overhead = sbi->s_overhead;
6538 
6539 	buf->f_type = EXT4_SUPER_MAGIC;
6540 	buf->f_bsize = sb->s_blocksize;
6541 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6542 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6543 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6544 	/* prevent underflow in case that few free space is available */
6545 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6546 	buf->f_bavail = buf->f_bfree -
6547 			(ext4_r_blocks_count(es) + resv_blocks);
6548 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6549 		buf->f_bavail = 0;
6550 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6551 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6552 	buf->f_namelen = EXT4_NAME_LEN;
6553 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6554 
6555 #ifdef CONFIG_QUOTA
6556 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6557 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6558 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6559 #endif
6560 	return 0;
6561 }
6562 
6563 
6564 #ifdef CONFIG_QUOTA
6565 
6566 /*
6567  * Helper functions so that transaction is started before we acquire dqio_sem
6568  * to keep correct lock ordering of transaction > dqio_sem
6569  */
6570 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6571 {
6572 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6573 }
6574 
6575 static int ext4_write_dquot(struct dquot *dquot)
6576 {
6577 	int ret, err;
6578 	handle_t *handle;
6579 	struct inode *inode;
6580 
6581 	inode = dquot_to_inode(dquot);
6582 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6583 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6584 	if (IS_ERR(handle))
6585 		return PTR_ERR(handle);
6586 	ret = dquot_commit(dquot);
6587 	err = ext4_journal_stop(handle);
6588 	if (!ret)
6589 		ret = err;
6590 	return ret;
6591 }
6592 
6593 static int ext4_acquire_dquot(struct dquot *dquot)
6594 {
6595 	int ret, err;
6596 	handle_t *handle;
6597 
6598 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6599 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6600 	if (IS_ERR(handle))
6601 		return PTR_ERR(handle);
6602 	ret = dquot_acquire(dquot);
6603 	err = ext4_journal_stop(handle);
6604 	if (!ret)
6605 		ret = err;
6606 	return ret;
6607 }
6608 
6609 static int ext4_release_dquot(struct dquot *dquot)
6610 {
6611 	int ret, err;
6612 	handle_t *handle;
6613 
6614 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6615 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6616 	if (IS_ERR(handle)) {
6617 		/* Release dquot anyway to avoid endless cycle in dqput() */
6618 		dquot_release(dquot);
6619 		return PTR_ERR(handle);
6620 	}
6621 	ret = dquot_release(dquot);
6622 	err = ext4_journal_stop(handle);
6623 	if (!ret)
6624 		ret = err;
6625 	return ret;
6626 }
6627 
6628 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6629 {
6630 	struct super_block *sb = dquot->dq_sb;
6631 
6632 	if (ext4_is_quota_journalled(sb)) {
6633 		dquot_mark_dquot_dirty(dquot);
6634 		return ext4_write_dquot(dquot);
6635 	} else {
6636 		return dquot_mark_dquot_dirty(dquot);
6637 	}
6638 }
6639 
6640 static int ext4_write_info(struct super_block *sb, int type)
6641 {
6642 	int ret, err;
6643 	handle_t *handle;
6644 
6645 	/* Data block + inode block */
6646 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6647 	if (IS_ERR(handle))
6648 		return PTR_ERR(handle);
6649 	ret = dquot_commit_info(sb, type);
6650 	err = ext4_journal_stop(handle);
6651 	if (!ret)
6652 		ret = err;
6653 	return ret;
6654 }
6655 
6656 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6657 {
6658 	struct ext4_inode_info *ei = EXT4_I(inode);
6659 
6660 	/* The first argument of lockdep_set_subclass has to be
6661 	 * *exactly* the same as the argument to init_rwsem() --- in
6662 	 * this case, in init_once() --- or lockdep gets unhappy
6663 	 * because the name of the lock is set using the
6664 	 * stringification of the argument to init_rwsem().
6665 	 */
6666 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6667 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6668 }
6669 
6670 /*
6671  * Standard function to be called on quota_on
6672  */
6673 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6674 			 const struct path *path)
6675 {
6676 	int err;
6677 
6678 	if (!test_opt(sb, QUOTA))
6679 		return -EINVAL;
6680 
6681 	/* Quotafile not on the same filesystem? */
6682 	if (path->dentry->d_sb != sb)
6683 		return -EXDEV;
6684 
6685 	/* Quota already enabled for this file? */
6686 	if (IS_NOQUOTA(d_inode(path->dentry)))
6687 		return -EBUSY;
6688 
6689 	/* Journaling quota? */
6690 	if (EXT4_SB(sb)->s_qf_names[type]) {
6691 		/* Quotafile not in fs root? */
6692 		if (path->dentry->d_parent != sb->s_root)
6693 			ext4_msg(sb, KERN_WARNING,
6694 				"Quota file not on filesystem root. "
6695 				"Journaled quota will not work");
6696 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6697 	} else {
6698 		/*
6699 		 * Clear the flag just in case mount options changed since
6700 		 * last time.
6701 		 */
6702 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6703 	}
6704 
6705 	/*
6706 	 * When we journal data on quota file, we have to flush journal to see
6707 	 * all updates to the file when we bypass pagecache...
6708 	 */
6709 	if (EXT4_SB(sb)->s_journal &&
6710 	    ext4_should_journal_data(d_inode(path->dentry))) {
6711 		/*
6712 		 * We don't need to lock updates but journal_flush() could
6713 		 * otherwise be livelocked...
6714 		 */
6715 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6716 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6717 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6718 		if (err)
6719 			return err;
6720 	}
6721 
6722 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6723 	err = dquot_quota_on(sb, type, format_id, path);
6724 	if (!err) {
6725 		struct inode *inode = d_inode(path->dentry);
6726 		handle_t *handle;
6727 
6728 		/*
6729 		 * Set inode flags to prevent userspace from messing with quota
6730 		 * files. If this fails, we return success anyway since quotas
6731 		 * are already enabled and this is not a hard failure.
6732 		 */
6733 		inode_lock(inode);
6734 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6735 		if (IS_ERR(handle))
6736 			goto unlock_inode;
6737 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6738 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6739 				S_NOATIME | S_IMMUTABLE);
6740 		err = ext4_mark_inode_dirty(handle, inode);
6741 		ext4_journal_stop(handle);
6742 	unlock_inode:
6743 		inode_unlock(inode);
6744 		if (err)
6745 			dquot_quota_off(sb, type);
6746 	}
6747 	if (err)
6748 		lockdep_set_quota_inode(path->dentry->d_inode,
6749 					     I_DATA_SEM_NORMAL);
6750 	return err;
6751 }
6752 
6753 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6754 			     unsigned int flags)
6755 {
6756 	int err;
6757 	struct inode *qf_inode;
6758 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6759 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6760 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6761 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6762 	};
6763 
6764 	BUG_ON(!ext4_has_feature_quota(sb));
6765 
6766 	if (!qf_inums[type])
6767 		return -EPERM;
6768 
6769 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6770 	if (IS_ERR(qf_inode)) {
6771 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6772 		return PTR_ERR(qf_inode);
6773 	}
6774 
6775 	/* Don't account quota for quota files to avoid recursion */
6776 	qf_inode->i_flags |= S_NOQUOTA;
6777 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6778 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6779 	if (err)
6780 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6781 	iput(qf_inode);
6782 
6783 	return err;
6784 }
6785 
6786 /* Enable usage tracking for all quota types. */
6787 int ext4_enable_quotas(struct super_block *sb)
6788 {
6789 	int type, err = 0;
6790 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6791 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6792 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6793 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6794 	};
6795 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6796 		test_opt(sb, USRQUOTA),
6797 		test_opt(sb, GRPQUOTA),
6798 		test_opt(sb, PRJQUOTA),
6799 	};
6800 
6801 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6802 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6803 		if (qf_inums[type]) {
6804 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6805 				DQUOT_USAGE_ENABLED |
6806 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6807 			if (err) {
6808 				ext4_warning(sb,
6809 					"Failed to enable quota tracking "
6810 					"(type=%d, err=%d). Please run "
6811 					"e2fsck to fix.", type, err);
6812 				for (type--; type >= 0; type--) {
6813 					struct inode *inode;
6814 
6815 					inode = sb_dqopt(sb)->files[type];
6816 					if (inode)
6817 						inode = igrab(inode);
6818 					dquot_quota_off(sb, type);
6819 					if (inode) {
6820 						lockdep_set_quota_inode(inode,
6821 							I_DATA_SEM_NORMAL);
6822 						iput(inode);
6823 					}
6824 				}
6825 
6826 				return err;
6827 			}
6828 		}
6829 	}
6830 	return 0;
6831 }
6832 
6833 static int ext4_quota_off(struct super_block *sb, int type)
6834 {
6835 	struct inode *inode = sb_dqopt(sb)->files[type];
6836 	handle_t *handle;
6837 	int err;
6838 
6839 	/* Force all delayed allocation blocks to be allocated.
6840 	 * Caller already holds s_umount sem */
6841 	if (test_opt(sb, DELALLOC))
6842 		sync_filesystem(sb);
6843 
6844 	if (!inode || !igrab(inode))
6845 		goto out;
6846 
6847 	err = dquot_quota_off(sb, type);
6848 	if (err || ext4_has_feature_quota(sb))
6849 		goto out_put;
6850 
6851 	inode_lock(inode);
6852 	/*
6853 	 * Update modification times of quota files when userspace can
6854 	 * start looking at them. If we fail, we return success anyway since
6855 	 * this is not a hard failure and quotas are already disabled.
6856 	 */
6857 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6858 	if (IS_ERR(handle)) {
6859 		err = PTR_ERR(handle);
6860 		goto out_unlock;
6861 	}
6862 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6863 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6864 	inode->i_mtime = inode->i_ctime = current_time(inode);
6865 	err = ext4_mark_inode_dirty(handle, inode);
6866 	ext4_journal_stop(handle);
6867 out_unlock:
6868 	inode_unlock(inode);
6869 out_put:
6870 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6871 	iput(inode);
6872 	return err;
6873 out:
6874 	return dquot_quota_off(sb, type);
6875 }
6876 
6877 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6878  * acquiring the locks... As quota files are never truncated and quota code
6879  * itself serializes the operations (and no one else should touch the files)
6880  * we don't have to be afraid of races */
6881 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6882 			       size_t len, loff_t off)
6883 {
6884 	struct inode *inode = sb_dqopt(sb)->files[type];
6885 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6886 	int offset = off & (sb->s_blocksize - 1);
6887 	int tocopy;
6888 	size_t toread;
6889 	struct buffer_head *bh;
6890 	loff_t i_size = i_size_read(inode);
6891 
6892 	if (off > i_size)
6893 		return 0;
6894 	if (off+len > i_size)
6895 		len = i_size-off;
6896 	toread = len;
6897 	while (toread > 0) {
6898 		tocopy = sb->s_blocksize - offset < toread ?
6899 				sb->s_blocksize - offset : toread;
6900 		bh = ext4_bread(NULL, inode, blk, 0);
6901 		if (IS_ERR(bh))
6902 			return PTR_ERR(bh);
6903 		if (!bh)	/* A hole? */
6904 			memset(data, 0, tocopy);
6905 		else
6906 			memcpy(data, bh->b_data+offset, tocopy);
6907 		brelse(bh);
6908 		offset = 0;
6909 		toread -= tocopy;
6910 		data += tocopy;
6911 		blk++;
6912 	}
6913 	return len;
6914 }
6915 
6916 /* Write to quotafile (we know the transaction is already started and has
6917  * enough credits) */
6918 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6919 				const char *data, size_t len, loff_t off)
6920 {
6921 	struct inode *inode = sb_dqopt(sb)->files[type];
6922 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6923 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6924 	int retries = 0;
6925 	struct buffer_head *bh;
6926 	handle_t *handle = journal_current_handle();
6927 
6928 	if (!handle) {
6929 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6930 			" cancelled because transaction is not started",
6931 			(unsigned long long)off, (unsigned long long)len);
6932 		return -EIO;
6933 	}
6934 	/*
6935 	 * Since we account only one data block in transaction credits,
6936 	 * then it is impossible to cross a block boundary.
6937 	 */
6938 	if (sb->s_blocksize - offset < len) {
6939 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6940 			" cancelled because not block aligned",
6941 			(unsigned long long)off, (unsigned long long)len);
6942 		return -EIO;
6943 	}
6944 
6945 	do {
6946 		bh = ext4_bread(handle, inode, blk,
6947 				EXT4_GET_BLOCKS_CREATE |
6948 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6949 	} while (PTR_ERR(bh) == -ENOSPC &&
6950 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6951 	if (IS_ERR(bh))
6952 		return PTR_ERR(bh);
6953 	if (!bh)
6954 		goto out;
6955 	BUFFER_TRACE(bh, "get write access");
6956 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
6957 	if (err) {
6958 		brelse(bh);
6959 		return err;
6960 	}
6961 	lock_buffer(bh);
6962 	memcpy(bh->b_data+offset, data, len);
6963 	flush_dcache_page(bh->b_page);
6964 	unlock_buffer(bh);
6965 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6966 	brelse(bh);
6967 out:
6968 	if (inode->i_size < off + len) {
6969 		i_size_write(inode, off + len);
6970 		EXT4_I(inode)->i_disksize = inode->i_size;
6971 		err2 = ext4_mark_inode_dirty(handle, inode);
6972 		if (unlikely(err2 && !err))
6973 			err = err2;
6974 	}
6975 	return err ? err : len;
6976 }
6977 #endif
6978 
6979 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6980 static inline void register_as_ext2(void)
6981 {
6982 	int err = register_filesystem(&ext2_fs_type);
6983 	if (err)
6984 		printk(KERN_WARNING
6985 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6986 }
6987 
6988 static inline void unregister_as_ext2(void)
6989 {
6990 	unregister_filesystem(&ext2_fs_type);
6991 }
6992 
6993 static inline int ext2_feature_set_ok(struct super_block *sb)
6994 {
6995 	if (ext4_has_unknown_ext2_incompat_features(sb))
6996 		return 0;
6997 	if (sb_rdonly(sb))
6998 		return 1;
6999 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7000 		return 0;
7001 	return 1;
7002 }
7003 #else
7004 static inline void register_as_ext2(void) { }
7005 static inline void unregister_as_ext2(void) { }
7006 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7007 #endif
7008 
7009 static inline void register_as_ext3(void)
7010 {
7011 	int err = register_filesystem(&ext3_fs_type);
7012 	if (err)
7013 		printk(KERN_WARNING
7014 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7015 }
7016 
7017 static inline void unregister_as_ext3(void)
7018 {
7019 	unregister_filesystem(&ext3_fs_type);
7020 }
7021 
7022 static inline int ext3_feature_set_ok(struct super_block *sb)
7023 {
7024 	if (ext4_has_unknown_ext3_incompat_features(sb))
7025 		return 0;
7026 	if (!ext4_has_feature_journal(sb))
7027 		return 0;
7028 	if (sb_rdonly(sb))
7029 		return 1;
7030 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7031 		return 0;
7032 	return 1;
7033 }
7034 
7035 static struct file_system_type ext4_fs_type = {
7036 	.owner			= THIS_MODULE,
7037 	.name			= "ext4",
7038 	.init_fs_context	= ext4_init_fs_context,
7039 	.parameters		= ext4_param_specs,
7040 	.kill_sb		= kill_block_super,
7041 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7042 };
7043 MODULE_ALIAS_FS("ext4");
7044 
7045 /* Shared across all ext4 file systems */
7046 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7047 
7048 static int __init ext4_init_fs(void)
7049 {
7050 	int i, err;
7051 
7052 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7053 	ext4_li_info = NULL;
7054 
7055 	/* Build-time check for flags consistency */
7056 	ext4_check_flag_values();
7057 
7058 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7059 		init_waitqueue_head(&ext4__ioend_wq[i]);
7060 
7061 	err = ext4_init_es();
7062 	if (err)
7063 		return err;
7064 
7065 	err = ext4_init_pending();
7066 	if (err)
7067 		goto out7;
7068 
7069 	err = ext4_init_post_read_processing();
7070 	if (err)
7071 		goto out6;
7072 
7073 	err = ext4_init_pageio();
7074 	if (err)
7075 		goto out5;
7076 
7077 	err = ext4_init_system_zone();
7078 	if (err)
7079 		goto out4;
7080 
7081 	err = ext4_init_sysfs();
7082 	if (err)
7083 		goto out3;
7084 
7085 	err = ext4_init_mballoc();
7086 	if (err)
7087 		goto out2;
7088 	err = init_inodecache();
7089 	if (err)
7090 		goto out1;
7091 
7092 	err = ext4_fc_init_dentry_cache();
7093 	if (err)
7094 		goto out05;
7095 
7096 	register_as_ext3();
7097 	register_as_ext2();
7098 	err = register_filesystem(&ext4_fs_type);
7099 	if (err)
7100 		goto out;
7101 
7102 	return 0;
7103 out:
7104 	unregister_as_ext2();
7105 	unregister_as_ext3();
7106 	ext4_fc_destroy_dentry_cache();
7107 out05:
7108 	destroy_inodecache();
7109 out1:
7110 	ext4_exit_mballoc();
7111 out2:
7112 	ext4_exit_sysfs();
7113 out3:
7114 	ext4_exit_system_zone();
7115 out4:
7116 	ext4_exit_pageio();
7117 out5:
7118 	ext4_exit_post_read_processing();
7119 out6:
7120 	ext4_exit_pending();
7121 out7:
7122 	ext4_exit_es();
7123 
7124 	return err;
7125 }
7126 
7127 static void __exit ext4_exit_fs(void)
7128 {
7129 	ext4_destroy_lazyinit_thread();
7130 	unregister_as_ext2();
7131 	unregister_as_ext3();
7132 	unregister_filesystem(&ext4_fs_type);
7133 	ext4_fc_destroy_dentry_cache();
7134 	destroy_inodecache();
7135 	ext4_exit_mballoc();
7136 	ext4_exit_sysfs();
7137 	ext4_exit_system_zone();
7138 	ext4_exit_pageio();
7139 	ext4_exit_post_read_processing();
7140 	ext4_exit_es();
7141 	ext4_exit_pending();
7142 }
7143 
7144 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7145 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7146 MODULE_LICENSE("GPL");
7147 MODULE_SOFTDEP("pre: crc32c");
7148 module_init(ext4_init_fs)
7149 module_exit(ext4_exit_fs)
7150