xref: /openbmc/linux/fs/ext4/super.c (revision 6562c9ac)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= kill_block_super,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= kill_block_super,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ | op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
207 {
208 	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,
231 					       blk_opf_t op_flags, 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 				   blk_opf_t 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, NULL);
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 
3015 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3016 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3017 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3018 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3019 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3020 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3021 	}
3022 
3023 	ext4_show_quota_options(seq, sb);
3024 	return 0;
3025 }
3026 
3027 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3028 {
3029 	return _ext4_show_options(seq, root->d_sb, 0);
3030 }
3031 
3032 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3033 {
3034 	struct super_block *sb = seq->private;
3035 	int rc;
3036 
3037 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3038 	rc = _ext4_show_options(seq, sb, 1);
3039 	seq_puts(seq, "\n");
3040 	return rc;
3041 }
3042 
3043 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3044 			    int read_only)
3045 {
3046 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3047 	int err = 0;
3048 
3049 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3050 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3051 			 "forcing read-only mode");
3052 		err = -EROFS;
3053 		goto done;
3054 	}
3055 	if (read_only)
3056 		goto done;
3057 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3058 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3059 			 "running e2fsck is recommended");
3060 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3061 		ext4_msg(sb, KERN_WARNING,
3062 			 "warning: mounting fs with errors, "
3063 			 "running e2fsck is recommended");
3064 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3065 		 le16_to_cpu(es->s_mnt_count) >=
3066 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3067 		ext4_msg(sb, KERN_WARNING,
3068 			 "warning: maximal mount count reached, "
3069 			 "running e2fsck is recommended");
3070 	else if (le32_to_cpu(es->s_checkinterval) &&
3071 		 (ext4_get_tstamp(es, s_lastcheck) +
3072 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3073 		ext4_msg(sb, KERN_WARNING,
3074 			 "warning: checktime reached, "
3075 			 "running e2fsck is recommended");
3076 	if (!sbi->s_journal)
3077 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3078 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3079 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3080 	le16_add_cpu(&es->s_mnt_count, 1);
3081 	ext4_update_tstamp(es, s_mtime);
3082 	if (sbi->s_journal) {
3083 		ext4_set_feature_journal_needs_recovery(sb);
3084 		if (ext4_has_feature_orphan_file(sb))
3085 			ext4_set_feature_orphan_present(sb);
3086 	}
3087 
3088 	err = ext4_commit_super(sb);
3089 done:
3090 	if (test_opt(sb, DEBUG))
3091 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3092 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3093 			sb->s_blocksize,
3094 			sbi->s_groups_count,
3095 			EXT4_BLOCKS_PER_GROUP(sb),
3096 			EXT4_INODES_PER_GROUP(sb),
3097 			sbi->s_mount_opt, sbi->s_mount_opt2);
3098 	return err;
3099 }
3100 
3101 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3102 {
3103 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3104 	struct flex_groups **old_groups, **new_groups;
3105 	int size, i, j;
3106 
3107 	if (!sbi->s_log_groups_per_flex)
3108 		return 0;
3109 
3110 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3111 	if (size <= sbi->s_flex_groups_allocated)
3112 		return 0;
3113 
3114 	new_groups = kvzalloc(roundup_pow_of_two(size *
3115 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3116 	if (!new_groups) {
3117 		ext4_msg(sb, KERN_ERR,
3118 			 "not enough memory for %d flex group pointers", size);
3119 		return -ENOMEM;
3120 	}
3121 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3122 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3123 					 sizeof(struct flex_groups)),
3124 					 GFP_KERNEL);
3125 		if (!new_groups[i]) {
3126 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3127 				kvfree(new_groups[j]);
3128 			kvfree(new_groups);
3129 			ext4_msg(sb, KERN_ERR,
3130 				 "not enough memory for %d flex groups", size);
3131 			return -ENOMEM;
3132 		}
3133 	}
3134 	rcu_read_lock();
3135 	old_groups = rcu_dereference(sbi->s_flex_groups);
3136 	if (old_groups)
3137 		memcpy(new_groups, old_groups,
3138 		       (sbi->s_flex_groups_allocated *
3139 			sizeof(struct flex_groups *)));
3140 	rcu_read_unlock();
3141 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3142 	sbi->s_flex_groups_allocated = size;
3143 	if (old_groups)
3144 		ext4_kvfree_array_rcu(old_groups);
3145 	return 0;
3146 }
3147 
3148 static int ext4_fill_flex_info(struct super_block *sb)
3149 {
3150 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3151 	struct ext4_group_desc *gdp = NULL;
3152 	struct flex_groups *fg;
3153 	ext4_group_t flex_group;
3154 	int i, err;
3155 
3156 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3157 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3158 		sbi->s_log_groups_per_flex = 0;
3159 		return 1;
3160 	}
3161 
3162 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3163 	if (err)
3164 		goto failed;
3165 
3166 	for (i = 0; i < sbi->s_groups_count; i++) {
3167 		gdp = ext4_get_group_desc(sb, i, NULL);
3168 
3169 		flex_group = ext4_flex_group(sbi, i);
3170 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3171 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3172 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3173 			     &fg->free_clusters);
3174 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3175 	}
3176 
3177 	return 1;
3178 failed:
3179 	return 0;
3180 }
3181 
3182 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3183 				   struct ext4_group_desc *gdp)
3184 {
3185 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3186 	__u16 crc = 0;
3187 	__le32 le_group = cpu_to_le32(block_group);
3188 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3189 
3190 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3191 		/* Use new metadata_csum algorithm */
3192 		__u32 csum32;
3193 		__u16 dummy_csum = 0;
3194 
3195 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3196 				     sizeof(le_group));
3197 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3198 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3199 				     sizeof(dummy_csum));
3200 		offset += sizeof(dummy_csum);
3201 		if (offset < sbi->s_desc_size)
3202 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3203 					     sbi->s_desc_size - offset);
3204 
3205 		crc = csum32 & 0xFFFF;
3206 		goto out;
3207 	}
3208 
3209 	/* old crc16 code */
3210 	if (!ext4_has_feature_gdt_csum(sb))
3211 		return 0;
3212 
3213 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3214 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3215 	crc = crc16(crc, (__u8 *)gdp, offset);
3216 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3217 	/* for checksum of struct ext4_group_desc do the rest...*/
3218 	if (ext4_has_feature_64bit(sb) &&
3219 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3220 		crc = crc16(crc, (__u8 *)gdp + offset,
3221 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3222 				offset);
3223 
3224 out:
3225 	return cpu_to_le16(crc);
3226 }
3227 
3228 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3229 				struct ext4_group_desc *gdp)
3230 {
3231 	if (ext4_has_group_desc_csum(sb) &&
3232 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3233 		return 0;
3234 
3235 	return 1;
3236 }
3237 
3238 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3239 			      struct ext4_group_desc *gdp)
3240 {
3241 	if (!ext4_has_group_desc_csum(sb))
3242 		return;
3243 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3244 }
3245 
3246 /* Called at mount-time, super-block is locked */
3247 static int ext4_check_descriptors(struct super_block *sb,
3248 				  ext4_fsblk_t sb_block,
3249 				  ext4_group_t *first_not_zeroed)
3250 {
3251 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3252 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3253 	ext4_fsblk_t last_block;
3254 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3255 	ext4_fsblk_t block_bitmap;
3256 	ext4_fsblk_t inode_bitmap;
3257 	ext4_fsblk_t inode_table;
3258 	int flexbg_flag = 0;
3259 	ext4_group_t i, grp = sbi->s_groups_count;
3260 
3261 	if (ext4_has_feature_flex_bg(sb))
3262 		flexbg_flag = 1;
3263 
3264 	ext4_debug("Checking group descriptors");
3265 
3266 	for (i = 0; i < sbi->s_groups_count; i++) {
3267 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3268 
3269 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3270 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3271 		else
3272 			last_block = first_block +
3273 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3274 
3275 		if ((grp == sbi->s_groups_count) &&
3276 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3277 			grp = i;
3278 
3279 		block_bitmap = ext4_block_bitmap(sb, gdp);
3280 		if (block_bitmap == sb_block) {
3281 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3282 				 "Block bitmap for group %u overlaps "
3283 				 "superblock", i);
3284 			if (!sb_rdonly(sb))
3285 				return 0;
3286 		}
3287 		if (block_bitmap >= sb_block + 1 &&
3288 		    block_bitmap <= last_bg_block) {
3289 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3290 				 "Block bitmap for group %u overlaps "
3291 				 "block group descriptors", i);
3292 			if (!sb_rdonly(sb))
3293 				return 0;
3294 		}
3295 		if (block_bitmap < first_block || block_bitmap > last_block) {
3296 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3297 			       "Block bitmap for group %u not in group "
3298 			       "(block %llu)!", i, block_bitmap);
3299 			return 0;
3300 		}
3301 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3302 		if (inode_bitmap == sb_block) {
3303 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3304 				 "Inode bitmap for group %u overlaps "
3305 				 "superblock", i);
3306 			if (!sb_rdonly(sb))
3307 				return 0;
3308 		}
3309 		if (inode_bitmap >= sb_block + 1 &&
3310 		    inode_bitmap <= last_bg_block) {
3311 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3312 				 "Inode bitmap for group %u overlaps "
3313 				 "block group descriptors", i);
3314 			if (!sb_rdonly(sb))
3315 				return 0;
3316 		}
3317 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3318 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3319 			       "Inode bitmap for group %u not in group "
3320 			       "(block %llu)!", i, inode_bitmap);
3321 			return 0;
3322 		}
3323 		inode_table = ext4_inode_table(sb, gdp);
3324 		if (inode_table == sb_block) {
3325 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3326 				 "Inode table for group %u overlaps "
3327 				 "superblock", i);
3328 			if (!sb_rdonly(sb))
3329 				return 0;
3330 		}
3331 		if (inode_table >= sb_block + 1 &&
3332 		    inode_table <= last_bg_block) {
3333 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3334 				 "Inode table for group %u overlaps "
3335 				 "block group descriptors", i);
3336 			if (!sb_rdonly(sb))
3337 				return 0;
3338 		}
3339 		if (inode_table < first_block ||
3340 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3341 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3342 			       "Inode table for group %u not in group "
3343 			       "(block %llu)!", i, inode_table);
3344 			return 0;
3345 		}
3346 		ext4_lock_group(sb, i);
3347 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3348 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3349 				 "Checksum for group %u failed (%u!=%u)",
3350 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3351 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3352 			if (!sb_rdonly(sb)) {
3353 				ext4_unlock_group(sb, i);
3354 				return 0;
3355 			}
3356 		}
3357 		ext4_unlock_group(sb, i);
3358 		if (!flexbg_flag)
3359 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3360 	}
3361 	if (NULL != first_not_zeroed)
3362 		*first_not_zeroed = grp;
3363 	return 1;
3364 }
3365 
3366 /*
3367  * Maximal extent format file size.
3368  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3369  * extent format containers, within a sector_t, and within i_blocks
3370  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3371  * so that won't be a limiting factor.
3372  *
3373  * However there is other limiting factor. We do store extents in the form
3374  * of starting block and length, hence the resulting length of the extent
3375  * covering maximum file size must fit into on-disk format containers as
3376  * well. Given that length is always by 1 unit bigger than max unit (because
3377  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3378  *
3379  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3380  */
3381 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3382 {
3383 	loff_t res;
3384 	loff_t upper_limit = MAX_LFS_FILESIZE;
3385 
3386 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3387 
3388 	if (!has_huge_files) {
3389 		upper_limit = (1LL << 32) - 1;
3390 
3391 		/* total blocks in file system block size */
3392 		upper_limit >>= (blkbits - 9);
3393 		upper_limit <<= blkbits;
3394 	}
3395 
3396 	/*
3397 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3398 	 * by one fs block, so ee_len can cover the extent of maximum file
3399 	 * size
3400 	 */
3401 	res = (1LL << 32) - 1;
3402 	res <<= blkbits;
3403 
3404 	/* Sanity check against vm- & vfs- imposed limits */
3405 	if (res > upper_limit)
3406 		res = upper_limit;
3407 
3408 	return res;
3409 }
3410 
3411 /*
3412  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3413  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3414  * We need to be 1 filesystem block less than the 2^48 sector limit.
3415  */
3416 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3417 {
3418 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3419 	int meta_blocks;
3420 	unsigned int ppb = 1 << (bits - 2);
3421 
3422 	/*
3423 	 * This is calculated to be the largest file size for a dense, block
3424 	 * mapped file such that the file's total number of 512-byte sectors,
3425 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3426 	 *
3427 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3428 	 * number of 512-byte sectors of the file.
3429 	 */
3430 	if (!has_huge_files) {
3431 		/*
3432 		 * !has_huge_files or implies that the inode i_block field
3433 		 * represents total file blocks in 2^32 512-byte sectors ==
3434 		 * size of vfs inode i_blocks * 8
3435 		 */
3436 		upper_limit = (1LL << 32) - 1;
3437 
3438 		/* total blocks in file system block size */
3439 		upper_limit >>= (bits - 9);
3440 
3441 	} else {
3442 		/*
3443 		 * We use 48 bit ext4_inode i_blocks
3444 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3445 		 * represent total number of blocks in
3446 		 * file system block size
3447 		 */
3448 		upper_limit = (1LL << 48) - 1;
3449 
3450 	}
3451 
3452 	/* Compute how many blocks we can address by block tree */
3453 	res += ppb;
3454 	res += ppb * ppb;
3455 	res += ((loff_t)ppb) * ppb * ppb;
3456 	/* Compute how many metadata blocks are needed */
3457 	meta_blocks = 1;
3458 	meta_blocks += 1 + ppb;
3459 	meta_blocks += 1 + ppb + ppb * ppb;
3460 	/* Does block tree limit file size? */
3461 	if (res + meta_blocks <= upper_limit)
3462 		goto check_lfs;
3463 
3464 	res = upper_limit;
3465 	/* How many metadata blocks are needed for addressing upper_limit? */
3466 	upper_limit -= EXT4_NDIR_BLOCKS;
3467 	/* indirect blocks */
3468 	meta_blocks = 1;
3469 	upper_limit -= ppb;
3470 	/* double indirect blocks */
3471 	if (upper_limit < ppb * ppb) {
3472 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3473 		res -= meta_blocks;
3474 		goto check_lfs;
3475 	}
3476 	meta_blocks += 1 + ppb;
3477 	upper_limit -= ppb * ppb;
3478 	/* tripple indirect blocks for the rest */
3479 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3480 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3481 	res -= meta_blocks;
3482 check_lfs:
3483 	res <<= bits;
3484 	if (res > MAX_LFS_FILESIZE)
3485 		res = MAX_LFS_FILESIZE;
3486 
3487 	return res;
3488 }
3489 
3490 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3491 				   ext4_fsblk_t logical_sb_block, int nr)
3492 {
3493 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3494 	ext4_group_t bg, first_meta_bg;
3495 	int has_super = 0;
3496 
3497 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3498 
3499 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3500 		return logical_sb_block + nr + 1;
3501 	bg = sbi->s_desc_per_block * nr;
3502 	if (ext4_bg_has_super(sb, bg))
3503 		has_super = 1;
3504 
3505 	/*
3506 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3507 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3508 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3509 	 * compensate.
3510 	 */
3511 	if (sb->s_blocksize == 1024 && nr == 0 &&
3512 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3513 		has_super++;
3514 
3515 	return (has_super + ext4_group_first_block_no(sb, bg));
3516 }
3517 
3518 /**
3519  * ext4_get_stripe_size: Get the stripe size.
3520  * @sbi: In memory super block info
3521  *
3522  * If we have specified it via mount option, then
3523  * use the mount option value. If the value specified at mount time is
3524  * greater than the blocks per group use the super block value.
3525  * If the super block value is greater than blocks per group return 0.
3526  * Allocator needs it be less than blocks per group.
3527  *
3528  */
3529 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3530 {
3531 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3532 	unsigned long stripe_width =
3533 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3534 	int ret;
3535 
3536 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3537 		ret = sbi->s_stripe;
3538 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3539 		ret = stripe_width;
3540 	else if (stride && stride <= sbi->s_blocks_per_group)
3541 		ret = stride;
3542 	else
3543 		ret = 0;
3544 
3545 	/*
3546 	 * If the stripe width is 1, this makes no sense and
3547 	 * we set it to 0 to turn off stripe handling code.
3548 	 */
3549 	if (ret <= 1)
3550 		ret = 0;
3551 
3552 	return ret;
3553 }
3554 
3555 /*
3556  * Check whether this filesystem can be mounted based on
3557  * the features present and the RDONLY/RDWR mount requested.
3558  * Returns 1 if this filesystem can be mounted as requested,
3559  * 0 if it cannot be.
3560  */
3561 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3562 {
3563 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3564 		ext4_msg(sb, KERN_ERR,
3565 			"Couldn't mount because of "
3566 			"unsupported optional features (%x)",
3567 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3568 			~EXT4_FEATURE_INCOMPAT_SUPP));
3569 		return 0;
3570 	}
3571 
3572 #if !IS_ENABLED(CONFIG_UNICODE)
3573 	if (ext4_has_feature_casefold(sb)) {
3574 		ext4_msg(sb, KERN_ERR,
3575 			 "Filesystem with casefold feature cannot be "
3576 			 "mounted without CONFIG_UNICODE");
3577 		return 0;
3578 	}
3579 #endif
3580 
3581 	if (readonly)
3582 		return 1;
3583 
3584 	if (ext4_has_feature_readonly(sb)) {
3585 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3586 		sb->s_flags |= SB_RDONLY;
3587 		return 1;
3588 	}
3589 
3590 	/* Check that feature set is OK for a read-write mount */
3591 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3592 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3593 			 "unsupported optional features (%x)",
3594 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3595 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3596 		return 0;
3597 	}
3598 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3599 		ext4_msg(sb, KERN_ERR,
3600 			 "Can't support bigalloc feature without "
3601 			 "extents feature\n");
3602 		return 0;
3603 	}
3604 
3605 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3606 	if (!readonly && (ext4_has_feature_quota(sb) ||
3607 			  ext4_has_feature_project(sb))) {
3608 		ext4_msg(sb, KERN_ERR,
3609 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3610 		return 0;
3611 	}
3612 #endif  /* CONFIG_QUOTA */
3613 	return 1;
3614 }
3615 
3616 /*
3617  * This function is called once a day if we have errors logged
3618  * on the file system
3619  */
3620 static void print_daily_error_info(struct timer_list *t)
3621 {
3622 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3623 	struct super_block *sb = sbi->s_sb;
3624 	struct ext4_super_block *es = sbi->s_es;
3625 
3626 	if (es->s_error_count)
3627 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3628 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3629 			 le32_to_cpu(es->s_error_count));
3630 	if (es->s_first_error_time) {
3631 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3632 		       sb->s_id,
3633 		       ext4_get_tstamp(es, s_first_error_time),
3634 		       (int) sizeof(es->s_first_error_func),
3635 		       es->s_first_error_func,
3636 		       le32_to_cpu(es->s_first_error_line));
3637 		if (es->s_first_error_ino)
3638 			printk(KERN_CONT ": inode %u",
3639 			       le32_to_cpu(es->s_first_error_ino));
3640 		if (es->s_first_error_block)
3641 			printk(KERN_CONT ": block %llu", (unsigned long long)
3642 			       le64_to_cpu(es->s_first_error_block));
3643 		printk(KERN_CONT "\n");
3644 	}
3645 	if (es->s_last_error_time) {
3646 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3647 		       sb->s_id,
3648 		       ext4_get_tstamp(es, s_last_error_time),
3649 		       (int) sizeof(es->s_last_error_func),
3650 		       es->s_last_error_func,
3651 		       le32_to_cpu(es->s_last_error_line));
3652 		if (es->s_last_error_ino)
3653 			printk(KERN_CONT ": inode %u",
3654 			       le32_to_cpu(es->s_last_error_ino));
3655 		if (es->s_last_error_block)
3656 			printk(KERN_CONT ": block %llu", (unsigned long long)
3657 			       le64_to_cpu(es->s_last_error_block));
3658 		printk(KERN_CONT "\n");
3659 	}
3660 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3661 }
3662 
3663 /* Find next suitable group and run ext4_init_inode_table */
3664 static int ext4_run_li_request(struct ext4_li_request *elr)
3665 {
3666 	struct ext4_group_desc *gdp = NULL;
3667 	struct super_block *sb = elr->lr_super;
3668 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3669 	ext4_group_t group = elr->lr_next_group;
3670 	unsigned int prefetch_ios = 0;
3671 	int ret = 0;
3672 	u64 start_time;
3673 
3674 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3675 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3676 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3677 		if (prefetch_ios)
3678 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3679 					      prefetch_ios);
3680 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3681 					    prefetch_ios);
3682 		if (group >= elr->lr_next_group) {
3683 			ret = 1;
3684 			if (elr->lr_first_not_zeroed != ngroups &&
3685 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3686 				elr->lr_next_group = elr->lr_first_not_zeroed;
3687 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3688 				ret = 0;
3689 			}
3690 		}
3691 		return ret;
3692 	}
3693 
3694 	for (; group < ngroups; group++) {
3695 		gdp = ext4_get_group_desc(sb, group, NULL);
3696 		if (!gdp) {
3697 			ret = 1;
3698 			break;
3699 		}
3700 
3701 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3702 			break;
3703 	}
3704 
3705 	if (group >= ngroups)
3706 		ret = 1;
3707 
3708 	if (!ret) {
3709 		start_time = ktime_get_real_ns();
3710 		ret = ext4_init_inode_table(sb, group,
3711 					    elr->lr_timeout ? 0 : 1);
3712 		trace_ext4_lazy_itable_init(sb, group);
3713 		if (elr->lr_timeout == 0) {
3714 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3715 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3716 		}
3717 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3718 		elr->lr_next_group = group + 1;
3719 	}
3720 	return ret;
3721 }
3722 
3723 /*
3724  * Remove lr_request from the list_request and free the
3725  * request structure. Should be called with li_list_mtx held
3726  */
3727 static void ext4_remove_li_request(struct ext4_li_request *elr)
3728 {
3729 	if (!elr)
3730 		return;
3731 
3732 	list_del(&elr->lr_request);
3733 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3734 	kfree(elr);
3735 }
3736 
3737 static void ext4_unregister_li_request(struct super_block *sb)
3738 {
3739 	mutex_lock(&ext4_li_mtx);
3740 	if (!ext4_li_info) {
3741 		mutex_unlock(&ext4_li_mtx);
3742 		return;
3743 	}
3744 
3745 	mutex_lock(&ext4_li_info->li_list_mtx);
3746 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3747 	mutex_unlock(&ext4_li_info->li_list_mtx);
3748 	mutex_unlock(&ext4_li_mtx);
3749 }
3750 
3751 static struct task_struct *ext4_lazyinit_task;
3752 
3753 /*
3754  * This is the function where ext4lazyinit thread lives. It walks
3755  * through the request list searching for next scheduled filesystem.
3756  * When such a fs is found, run the lazy initialization request
3757  * (ext4_rn_li_request) and keep track of the time spend in this
3758  * function. Based on that time we compute next schedule time of
3759  * the request. When walking through the list is complete, compute
3760  * next waking time and put itself into sleep.
3761  */
3762 static int ext4_lazyinit_thread(void *arg)
3763 {
3764 	struct ext4_lazy_init *eli = arg;
3765 	struct list_head *pos, *n;
3766 	struct ext4_li_request *elr;
3767 	unsigned long next_wakeup, cur;
3768 
3769 	BUG_ON(NULL == eli);
3770 
3771 cont_thread:
3772 	while (true) {
3773 		next_wakeup = MAX_JIFFY_OFFSET;
3774 
3775 		mutex_lock(&eli->li_list_mtx);
3776 		if (list_empty(&eli->li_request_list)) {
3777 			mutex_unlock(&eli->li_list_mtx);
3778 			goto exit_thread;
3779 		}
3780 		list_for_each_safe(pos, n, &eli->li_request_list) {
3781 			int err = 0;
3782 			int progress = 0;
3783 			elr = list_entry(pos, struct ext4_li_request,
3784 					 lr_request);
3785 
3786 			if (time_before(jiffies, elr->lr_next_sched)) {
3787 				if (time_before(elr->lr_next_sched, next_wakeup))
3788 					next_wakeup = elr->lr_next_sched;
3789 				continue;
3790 			}
3791 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3792 				if (sb_start_write_trylock(elr->lr_super)) {
3793 					progress = 1;
3794 					/*
3795 					 * We hold sb->s_umount, sb can not
3796 					 * be removed from the list, it is
3797 					 * now safe to drop li_list_mtx
3798 					 */
3799 					mutex_unlock(&eli->li_list_mtx);
3800 					err = ext4_run_li_request(elr);
3801 					sb_end_write(elr->lr_super);
3802 					mutex_lock(&eli->li_list_mtx);
3803 					n = pos->next;
3804 				}
3805 				up_read((&elr->lr_super->s_umount));
3806 			}
3807 			/* error, remove the lazy_init job */
3808 			if (err) {
3809 				ext4_remove_li_request(elr);
3810 				continue;
3811 			}
3812 			if (!progress) {
3813 				elr->lr_next_sched = jiffies +
3814 					(prandom_u32()
3815 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3816 			}
3817 			if (time_before(elr->lr_next_sched, next_wakeup))
3818 				next_wakeup = elr->lr_next_sched;
3819 		}
3820 		mutex_unlock(&eli->li_list_mtx);
3821 
3822 		try_to_freeze();
3823 
3824 		cur = jiffies;
3825 		if ((time_after_eq(cur, next_wakeup)) ||
3826 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3827 			cond_resched();
3828 			continue;
3829 		}
3830 
3831 		schedule_timeout_interruptible(next_wakeup - cur);
3832 
3833 		if (kthread_should_stop()) {
3834 			ext4_clear_request_list();
3835 			goto exit_thread;
3836 		}
3837 	}
3838 
3839 exit_thread:
3840 	/*
3841 	 * It looks like the request list is empty, but we need
3842 	 * to check it under the li_list_mtx lock, to prevent any
3843 	 * additions into it, and of course we should lock ext4_li_mtx
3844 	 * to atomically free the list and ext4_li_info, because at
3845 	 * this point another ext4 filesystem could be registering
3846 	 * new one.
3847 	 */
3848 	mutex_lock(&ext4_li_mtx);
3849 	mutex_lock(&eli->li_list_mtx);
3850 	if (!list_empty(&eli->li_request_list)) {
3851 		mutex_unlock(&eli->li_list_mtx);
3852 		mutex_unlock(&ext4_li_mtx);
3853 		goto cont_thread;
3854 	}
3855 	mutex_unlock(&eli->li_list_mtx);
3856 	kfree(ext4_li_info);
3857 	ext4_li_info = NULL;
3858 	mutex_unlock(&ext4_li_mtx);
3859 
3860 	return 0;
3861 }
3862 
3863 static void ext4_clear_request_list(void)
3864 {
3865 	struct list_head *pos, *n;
3866 	struct ext4_li_request *elr;
3867 
3868 	mutex_lock(&ext4_li_info->li_list_mtx);
3869 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3870 		elr = list_entry(pos, struct ext4_li_request,
3871 				 lr_request);
3872 		ext4_remove_li_request(elr);
3873 	}
3874 	mutex_unlock(&ext4_li_info->li_list_mtx);
3875 }
3876 
3877 static int ext4_run_lazyinit_thread(void)
3878 {
3879 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3880 					 ext4_li_info, "ext4lazyinit");
3881 	if (IS_ERR(ext4_lazyinit_task)) {
3882 		int err = PTR_ERR(ext4_lazyinit_task);
3883 		ext4_clear_request_list();
3884 		kfree(ext4_li_info);
3885 		ext4_li_info = NULL;
3886 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3887 				 "initialization thread\n",
3888 				 err);
3889 		return err;
3890 	}
3891 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3892 	return 0;
3893 }
3894 
3895 /*
3896  * Check whether it make sense to run itable init. thread or not.
3897  * If there is at least one uninitialized inode table, return
3898  * corresponding group number, else the loop goes through all
3899  * groups and return total number of groups.
3900  */
3901 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3902 {
3903 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3904 	struct ext4_group_desc *gdp = NULL;
3905 
3906 	if (!ext4_has_group_desc_csum(sb))
3907 		return ngroups;
3908 
3909 	for (group = 0; group < ngroups; group++) {
3910 		gdp = ext4_get_group_desc(sb, group, NULL);
3911 		if (!gdp)
3912 			continue;
3913 
3914 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3915 			break;
3916 	}
3917 
3918 	return group;
3919 }
3920 
3921 static int ext4_li_info_new(void)
3922 {
3923 	struct ext4_lazy_init *eli = NULL;
3924 
3925 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3926 	if (!eli)
3927 		return -ENOMEM;
3928 
3929 	INIT_LIST_HEAD(&eli->li_request_list);
3930 	mutex_init(&eli->li_list_mtx);
3931 
3932 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3933 
3934 	ext4_li_info = eli;
3935 
3936 	return 0;
3937 }
3938 
3939 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3940 					    ext4_group_t start)
3941 {
3942 	struct ext4_li_request *elr;
3943 
3944 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3945 	if (!elr)
3946 		return NULL;
3947 
3948 	elr->lr_super = sb;
3949 	elr->lr_first_not_zeroed = start;
3950 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3951 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3952 		elr->lr_next_group = start;
3953 	} else {
3954 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3955 	}
3956 
3957 	/*
3958 	 * Randomize first schedule time of the request to
3959 	 * spread the inode table initialization requests
3960 	 * better.
3961 	 */
3962 	elr->lr_next_sched = jiffies + (prandom_u32() %
3963 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3964 	return elr;
3965 }
3966 
3967 int ext4_register_li_request(struct super_block *sb,
3968 			     ext4_group_t first_not_zeroed)
3969 {
3970 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3971 	struct ext4_li_request *elr = NULL;
3972 	ext4_group_t ngroups = sbi->s_groups_count;
3973 	int ret = 0;
3974 
3975 	mutex_lock(&ext4_li_mtx);
3976 	if (sbi->s_li_request != NULL) {
3977 		/*
3978 		 * Reset timeout so it can be computed again, because
3979 		 * s_li_wait_mult might have changed.
3980 		 */
3981 		sbi->s_li_request->lr_timeout = 0;
3982 		goto out;
3983 	}
3984 
3985 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3986 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3987 	     !test_opt(sb, INIT_INODE_TABLE)))
3988 		goto out;
3989 
3990 	elr = ext4_li_request_new(sb, first_not_zeroed);
3991 	if (!elr) {
3992 		ret = -ENOMEM;
3993 		goto out;
3994 	}
3995 
3996 	if (NULL == ext4_li_info) {
3997 		ret = ext4_li_info_new();
3998 		if (ret)
3999 			goto out;
4000 	}
4001 
4002 	mutex_lock(&ext4_li_info->li_list_mtx);
4003 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4004 	mutex_unlock(&ext4_li_info->li_list_mtx);
4005 
4006 	sbi->s_li_request = elr;
4007 	/*
4008 	 * set elr to NULL here since it has been inserted to
4009 	 * the request_list and the removal and free of it is
4010 	 * handled by ext4_clear_request_list from now on.
4011 	 */
4012 	elr = NULL;
4013 
4014 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4015 		ret = ext4_run_lazyinit_thread();
4016 		if (ret)
4017 			goto out;
4018 	}
4019 out:
4020 	mutex_unlock(&ext4_li_mtx);
4021 	if (ret)
4022 		kfree(elr);
4023 	return ret;
4024 }
4025 
4026 /*
4027  * We do not need to lock anything since this is called on
4028  * module unload.
4029  */
4030 static void ext4_destroy_lazyinit_thread(void)
4031 {
4032 	/*
4033 	 * If thread exited earlier
4034 	 * there's nothing to be done.
4035 	 */
4036 	if (!ext4_li_info || !ext4_lazyinit_task)
4037 		return;
4038 
4039 	kthread_stop(ext4_lazyinit_task);
4040 }
4041 
4042 static int set_journal_csum_feature_set(struct super_block *sb)
4043 {
4044 	int ret = 1;
4045 	int compat, incompat;
4046 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4047 
4048 	if (ext4_has_metadata_csum(sb)) {
4049 		/* journal checksum v3 */
4050 		compat = 0;
4051 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4052 	} else {
4053 		/* journal checksum v1 */
4054 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4055 		incompat = 0;
4056 	}
4057 
4058 	jbd2_journal_clear_features(sbi->s_journal,
4059 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4060 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4061 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4062 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4063 		ret = jbd2_journal_set_features(sbi->s_journal,
4064 				compat, 0,
4065 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4066 				incompat);
4067 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4068 		ret = jbd2_journal_set_features(sbi->s_journal,
4069 				compat, 0,
4070 				incompat);
4071 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4072 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4073 	} else {
4074 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4075 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4076 	}
4077 
4078 	return ret;
4079 }
4080 
4081 /*
4082  * Note: calculating the overhead so we can be compatible with
4083  * historical BSD practice is quite difficult in the face of
4084  * clusters/bigalloc.  This is because multiple metadata blocks from
4085  * different block group can end up in the same allocation cluster.
4086  * Calculating the exact overhead in the face of clustered allocation
4087  * requires either O(all block bitmaps) in memory or O(number of block
4088  * groups**2) in time.  We will still calculate the superblock for
4089  * older file systems --- and if we come across with a bigalloc file
4090  * system with zero in s_overhead_clusters the estimate will be close to
4091  * correct especially for very large cluster sizes --- but for newer
4092  * file systems, it's better to calculate this figure once at mkfs
4093  * time, and store it in the superblock.  If the superblock value is
4094  * present (even for non-bigalloc file systems), we will use it.
4095  */
4096 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4097 			  char *buf)
4098 {
4099 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4100 	struct ext4_group_desc	*gdp;
4101 	ext4_fsblk_t		first_block, last_block, b;
4102 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4103 	int			s, j, count = 0;
4104 	int			has_super = ext4_bg_has_super(sb, grp);
4105 
4106 	if (!ext4_has_feature_bigalloc(sb))
4107 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4108 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4109 			sbi->s_itb_per_group + 2);
4110 
4111 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4112 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4113 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4114 	for (i = 0; i < ngroups; i++) {
4115 		gdp = ext4_get_group_desc(sb, i, NULL);
4116 		b = ext4_block_bitmap(sb, gdp);
4117 		if (b >= first_block && b <= last_block) {
4118 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4119 			count++;
4120 		}
4121 		b = ext4_inode_bitmap(sb, gdp);
4122 		if (b >= first_block && b <= last_block) {
4123 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4124 			count++;
4125 		}
4126 		b = ext4_inode_table(sb, gdp);
4127 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4128 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4129 				int c = EXT4_B2C(sbi, b - first_block);
4130 				ext4_set_bit(c, buf);
4131 				count++;
4132 			}
4133 		if (i != grp)
4134 			continue;
4135 		s = 0;
4136 		if (ext4_bg_has_super(sb, grp)) {
4137 			ext4_set_bit(s++, buf);
4138 			count++;
4139 		}
4140 		j = ext4_bg_num_gdb(sb, grp);
4141 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4142 			ext4_error(sb, "Invalid number of block group "
4143 				   "descriptor blocks: %d", j);
4144 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4145 		}
4146 		count += j;
4147 		for (; j > 0; j--)
4148 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4149 	}
4150 	if (!count)
4151 		return 0;
4152 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4153 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4154 }
4155 
4156 /*
4157  * Compute the overhead and stash it in sbi->s_overhead
4158  */
4159 int ext4_calculate_overhead(struct super_block *sb)
4160 {
4161 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4162 	struct ext4_super_block *es = sbi->s_es;
4163 	struct inode *j_inode;
4164 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4165 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4166 	ext4_fsblk_t overhead = 0;
4167 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4168 
4169 	if (!buf)
4170 		return -ENOMEM;
4171 
4172 	/*
4173 	 * Compute the overhead (FS structures).  This is constant
4174 	 * for a given filesystem unless the number of block groups
4175 	 * changes so we cache the previous value until it does.
4176 	 */
4177 
4178 	/*
4179 	 * All of the blocks before first_data_block are overhead
4180 	 */
4181 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4182 
4183 	/*
4184 	 * Add the overhead found in each block group
4185 	 */
4186 	for (i = 0; i < ngroups; i++) {
4187 		int blks;
4188 
4189 		blks = count_overhead(sb, i, buf);
4190 		overhead += blks;
4191 		if (blks)
4192 			memset(buf, 0, PAGE_SIZE);
4193 		cond_resched();
4194 	}
4195 
4196 	/*
4197 	 * Add the internal journal blocks whether the journal has been
4198 	 * loaded or not
4199 	 */
4200 	if (sbi->s_journal && !sbi->s_journal_bdev)
4201 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4202 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4203 		/* j_inum for internal journal is non-zero */
4204 		j_inode = ext4_get_journal_inode(sb, j_inum);
4205 		if (j_inode) {
4206 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4207 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4208 			iput(j_inode);
4209 		} else {
4210 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4211 		}
4212 	}
4213 	sbi->s_overhead = overhead;
4214 	smp_wmb();
4215 	free_page((unsigned long) buf);
4216 	return 0;
4217 }
4218 
4219 static void ext4_set_resv_clusters(struct super_block *sb)
4220 {
4221 	ext4_fsblk_t resv_clusters;
4222 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4223 
4224 	/*
4225 	 * There's no need to reserve anything when we aren't using extents.
4226 	 * The space estimates are exact, there are no unwritten extents,
4227 	 * hole punching doesn't need new metadata... This is needed especially
4228 	 * to keep ext2/3 backward compatibility.
4229 	 */
4230 	if (!ext4_has_feature_extents(sb))
4231 		return;
4232 	/*
4233 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4234 	 * This should cover the situations where we can not afford to run
4235 	 * out of space like for example punch hole, or converting
4236 	 * unwritten extents in delalloc path. In most cases such
4237 	 * allocation would require 1, or 2 blocks, higher numbers are
4238 	 * very rare.
4239 	 */
4240 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4241 			 sbi->s_cluster_bits);
4242 
4243 	do_div(resv_clusters, 50);
4244 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4245 
4246 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4247 }
4248 
4249 static const char *ext4_quota_mode(struct super_block *sb)
4250 {
4251 #ifdef CONFIG_QUOTA
4252 	if (!ext4_quota_capable(sb))
4253 		return "none";
4254 
4255 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4256 		return "journalled";
4257 	else
4258 		return "writeback";
4259 #else
4260 	return "disabled";
4261 #endif
4262 }
4263 
4264 static void ext4_setup_csum_trigger(struct super_block *sb,
4265 				    enum ext4_journal_trigger_type type,
4266 				    void (*trigger)(
4267 					struct jbd2_buffer_trigger_type *type,
4268 					struct buffer_head *bh,
4269 					void *mapped_data,
4270 					size_t size))
4271 {
4272 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4273 
4274 	sbi->s_journal_triggers[type].sb = sb;
4275 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4276 }
4277 
4278 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4279 {
4280 	if (!sbi)
4281 		return;
4282 
4283 	kfree(sbi->s_blockgroup_lock);
4284 	fs_put_dax(sbi->s_daxdev, NULL);
4285 	kfree(sbi);
4286 }
4287 
4288 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4289 {
4290 	struct ext4_sb_info *sbi;
4291 
4292 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4293 	if (!sbi)
4294 		return NULL;
4295 
4296 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4297 					   NULL, NULL);
4298 
4299 	sbi->s_blockgroup_lock =
4300 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4301 
4302 	if (!sbi->s_blockgroup_lock)
4303 		goto err_out;
4304 
4305 	sb->s_fs_info = sbi;
4306 	sbi->s_sb = sb;
4307 	return sbi;
4308 err_out:
4309 	fs_put_dax(sbi->s_daxdev, NULL);
4310 	kfree(sbi);
4311 	return NULL;
4312 }
4313 
4314 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
4315 {
4316 	struct buffer_head *bh, **group_desc;
4317 	struct ext4_super_block *es = NULL;
4318 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4319 	struct flex_groups **flex_groups;
4320 	ext4_fsblk_t block;
4321 	ext4_fsblk_t logical_sb_block;
4322 	unsigned long offset = 0;
4323 	unsigned long def_mount_opts;
4324 	struct inode *root;
4325 	int ret = -ENOMEM;
4326 	int blocksize, clustersize;
4327 	unsigned int db_count;
4328 	unsigned int i;
4329 	int needs_recovery, has_huge_files;
4330 	__u64 blocks_count;
4331 	int err = 0;
4332 	ext4_group_t first_not_zeroed;
4333 	struct ext4_fs_context *ctx = fc->fs_private;
4334 	int silent = fc->sb_flags & SB_SILENT;
4335 
4336 	/* Set defaults for the variables that will be set during parsing */
4337 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
4338 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4339 
4340 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4341 	sbi->s_sectors_written_start =
4342 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4343 
4344 	/* -EINVAL is default */
4345 	ret = -EINVAL;
4346 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4347 	if (!blocksize) {
4348 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4349 		goto out_fail;
4350 	}
4351 
4352 	/*
4353 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4354 	 * block sizes.  We need to calculate the offset from buffer start.
4355 	 */
4356 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4357 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4358 		offset = do_div(logical_sb_block, blocksize);
4359 	} else {
4360 		logical_sb_block = sbi->s_sb_block;
4361 	}
4362 
4363 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4364 	if (IS_ERR(bh)) {
4365 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4366 		ret = PTR_ERR(bh);
4367 		goto out_fail;
4368 	}
4369 	/*
4370 	 * Note: s_es must be initialized as soon as possible because
4371 	 *       some ext4 macro-instructions depend on its value
4372 	 */
4373 	es = (struct ext4_super_block *) (bh->b_data + offset);
4374 	sbi->s_es = es;
4375 	sb->s_magic = le16_to_cpu(es->s_magic);
4376 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4377 		goto cantfind_ext4;
4378 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4379 
4380 	/* Warn if metadata_csum and gdt_csum are both set. */
4381 	if (ext4_has_feature_metadata_csum(sb) &&
4382 	    ext4_has_feature_gdt_csum(sb))
4383 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4384 			     "redundant flags; please run fsck.");
4385 
4386 	/* Check for a known checksum algorithm */
4387 	if (!ext4_verify_csum_type(sb, es)) {
4388 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4389 			 "unknown checksum algorithm.");
4390 		silent = 1;
4391 		goto cantfind_ext4;
4392 	}
4393 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4394 				ext4_orphan_file_block_trigger);
4395 
4396 	/* Load the checksum driver */
4397 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4398 	if (IS_ERR(sbi->s_chksum_driver)) {
4399 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4400 		ret = PTR_ERR(sbi->s_chksum_driver);
4401 		sbi->s_chksum_driver = NULL;
4402 		goto failed_mount;
4403 	}
4404 
4405 	/* Check superblock checksum */
4406 	if (!ext4_superblock_csum_verify(sb, es)) {
4407 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4408 			 "invalid superblock checksum.  Run e2fsck?");
4409 		silent = 1;
4410 		ret = -EFSBADCRC;
4411 		goto cantfind_ext4;
4412 	}
4413 
4414 	/* Precompute checksum seed for all metadata */
4415 	if (ext4_has_feature_csum_seed(sb))
4416 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4417 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4418 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4419 					       sizeof(es->s_uuid));
4420 
4421 	/* Set defaults before we parse the mount options */
4422 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4423 	set_opt(sb, INIT_INODE_TABLE);
4424 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4425 		set_opt(sb, DEBUG);
4426 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4427 		set_opt(sb, GRPID);
4428 	if (def_mount_opts & EXT4_DEFM_UID16)
4429 		set_opt(sb, NO_UID32);
4430 	/* xattr user namespace & acls are now defaulted on */
4431 	set_opt(sb, XATTR_USER);
4432 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4433 	set_opt(sb, POSIX_ACL);
4434 #endif
4435 	if (ext4_has_feature_fast_commit(sb))
4436 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4437 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4438 	if (ext4_has_metadata_csum(sb))
4439 		set_opt(sb, JOURNAL_CHECKSUM);
4440 
4441 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4442 		set_opt(sb, JOURNAL_DATA);
4443 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4444 		set_opt(sb, ORDERED_DATA);
4445 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4446 		set_opt(sb, WRITEBACK_DATA);
4447 
4448 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4449 		set_opt(sb, ERRORS_PANIC);
4450 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4451 		set_opt(sb, ERRORS_CONT);
4452 	else
4453 		set_opt(sb, ERRORS_RO);
4454 	/* block_validity enabled by default; disable with noblock_validity */
4455 	set_opt(sb, BLOCK_VALIDITY);
4456 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4457 		set_opt(sb, DISCARD);
4458 
4459 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4460 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4461 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4462 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4463 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4464 
4465 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4466 		set_opt(sb, BARRIER);
4467 
4468 	/*
4469 	 * enable delayed allocation by default
4470 	 * Use -o nodelalloc to turn it off
4471 	 */
4472 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4473 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4474 		set_opt(sb, DELALLOC);
4475 
4476 	/*
4477 	 * set default s_li_wait_mult for lazyinit, for the case there is
4478 	 * no mount option specified.
4479 	 */
4480 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4481 
4482 	if (le32_to_cpu(es->s_log_block_size) >
4483 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4484 		ext4_msg(sb, KERN_ERR,
4485 			 "Invalid log block size: %u",
4486 			 le32_to_cpu(es->s_log_block_size));
4487 		goto failed_mount;
4488 	}
4489 	if (le32_to_cpu(es->s_log_cluster_size) >
4490 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4491 		ext4_msg(sb, KERN_ERR,
4492 			 "Invalid log cluster size: %u",
4493 			 le32_to_cpu(es->s_log_cluster_size));
4494 		goto failed_mount;
4495 	}
4496 
4497 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4498 
4499 	if (blocksize == PAGE_SIZE)
4500 		set_opt(sb, DIOREAD_NOLOCK);
4501 
4502 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4503 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4504 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4505 	} else {
4506 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4507 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4508 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4509 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4510 				 sbi->s_first_ino);
4511 			goto failed_mount;
4512 		}
4513 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4514 		    (!is_power_of_2(sbi->s_inode_size)) ||
4515 		    (sbi->s_inode_size > blocksize)) {
4516 			ext4_msg(sb, KERN_ERR,
4517 			       "unsupported inode size: %d",
4518 			       sbi->s_inode_size);
4519 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4520 			goto failed_mount;
4521 		}
4522 		/*
4523 		 * i_atime_extra is the last extra field available for
4524 		 * [acm]times in struct ext4_inode. Checking for that
4525 		 * field should suffice to ensure we have extra space
4526 		 * for all three.
4527 		 */
4528 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4529 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4530 			sb->s_time_gran = 1;
4531 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4532 		} else {
4533 			sb->s_time_gran = NSEC_PER_SEC;
4534 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4535 		}
4536 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4537 	}
4538 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4539 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4540 			EXT4_GOOD_OLD_INODE_SIZE;
4541 		if (ext4_has_feature_extra_isize(sb)) {
4542 			unsigned v, max = (sbi->s_inode_size -
4543 					   EXT4_GOOD_OLD_INODE_SIZE);
4544 
4545 			v = le16_to_cpu(es->s_want_extra_isize);
4546 			if (v > max) {
4547 				ext4_msg(sb, KERN_ERR,
4548 					 "bad s_want_extra_isize: %d", v);
4549 				goto failed_mount;
4550 			}
4551 			if (sbi->s_want_extra_isize < v)
4552 				sbi->s_want_extra_isize = v;
4553 
4554 			v = le16_to_cpu(es->s_min_extra_isize);
4555 			if (v > max) {
4556 				ext4_msg(sb, KERN_ERR,
4557 					 "bad s_min_extra_isize: %d", v);
4558 				goto failed_mount;
4559 			}
4560 			if (sbi->s_want_extra_isize < v)
4561 				sbi->s_want_extra_isize = v;
4562 		}
4563 	}
4564 
4565 	err = parse_apply_sb_mount_options(sb, ctx);
4566 	if (err < 0)
4567 		goto failed_mount;
4568 
4569 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4570 
4571 	err = ext4_check_opt_consistency(fc, sb);
4572 	if (err < 0)
4573 		goto failed_mount;
4574 
4575 	ext4_apply_options(fc, sb);
4576 
4577 #if IS_ENABLED(CONFIG_UNICODE)
4578 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4579 		const struct ext4_sb_encodings *encoding_info;
4580 		struct unicode_map *encoding;
4581 		__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4582 
4583 		encoding_info = ext4_sb_read_encoding(es);
4584 		if (!encoding_info) {
4585 			ext4_msg(sb, KERN_ERR,
4586 				 "Encoding requested by superblock is unknown");
4587 			goto failed_mount;
4588 		}
4589 
4590 		encoding = utf8_load(encoding_info->version);
4591 		if (IS_ERR(encoding)) {
4592 			ext4_msg(sb, KERN_ERR,
4593 				 "can't mount with superblock charset: %s-%u.%u.%u "
4594 				 "not supported by the kernel. flags: 0x%x.",
4595 				 encoding_info->name,
4596 				 unicode_major(encoding_info->version),
4597 				 unicode_minor(encoding_info->version),
4598 				 unicode_rev(encoding_info->version),
4599 				 encoding_flags);
4600 			goto failed_mount;
4601 		}
4602 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4603 			 "%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4604 			 unicode_major(encoding_info->version),
4605 			 unicode_minor(encoding_info->version),
4606 			 unicode_rev(encoding_info->version),
4607 			 encoding_flags);
4608 
4609 		sb->s_encoding = encoding;
4610 		sb->s_encoding_flags = encoding_flags;
4611 	}
4612 #endif
4613 
4614 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4615 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4616 		/* can't mount with both data=journal and dioread_nolock. */
4617 		clear_opt(sb, DIOREAD_NOLOCK);
4618 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4619 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4620 			ext4_msg(sb, KERN_ERR, "can't mount with "
4621 				 "both data=journal and delalloc");
4622 			goto failed_mount;
4623 		}
4624 		if (test_opt(sb, DAX_ALWAYS)) {
4625 			ext4_msg(sb, KERN_ERR, "can't mount with "
4626 				 "both data=journal and dax");
4627 			goto failed_mount;
4628 		}
4629 		if (ext4_has_feature_encrypt(sb)) {
4630 			ext4_msg(sb, KERN_WARNING,
4631 				 "encrypted files will use data=ordered "
4632 				 "instead of data journaling mode");
4633 		}
4634 		if (test_opt(sb, DELALLOC))
4635 			clear_opt(sb, DELALLOC);
4636 	} else {
4637 		sb->s_iflags |= SB_I_CGROUPWB;
4638 	}
4639 
4640 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4641 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4642 
4643 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4644 	    (ext4_has_compat_features(sb) ||
4645 	     ext4_has_ro_compat_features(sb) ||
4646 	     ext4_has_incompat_features(sb)))
4647 		ext4_msg(sb, KERN_WARNING,
4648 		       "feature flags set on rev 0 fs, "
4649 		       "running e2fsck is recommended");
4650 
4651 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4652 		set_opt2(sb, HURD_COMPAT);
4653 		if (ext4_has_feature_64bit(sb)) {
4654 			ext4_msg(sb, KERN_ERR,
4655 				 "The Hurd can't support 64-bit file systems");
4656 			goto failed_mount;
4657 		}
4658 
4659 		/*
4660 		 * ea_inode feature uses l_i_version field which is not
4661 		 * available in HURD_COMPAT mode.
4662 		 */
4663 		if (ext4_has_feature_ea_inode(sb)) {
4664 			ext4_msg(sb, KERN_ERR,
4665 				 "ea_inode feature is not supported for Hurd");
4666 			goto failed_mount;
4667 		}
4668 	}
4669 
4670 	if (IS_EXT2_SB(sb)) {
4671 		if (ext2_feature_set_ok(sb))
4672 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4673 				 "using the ext4 subsystem");
4674 		else {
4675 			/*
4676 			 * If we're probing be silent, if this looks like
4677 			 * it's actually an ext[34] filesystem.
4678 			 */
4679 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4680 				goto failed_mount;
4681 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4682 				 "to feature incompatibilities");
4683 			goto failed_mount;
4684 		}
4685 	}
4686 
4687 	if (IS_EXT3_SB(sb)) {
4688 		if (ext3_feature_set_ok(sb))
4689 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4690 				 "using the ext4 subsystem");
4691 		else {
4692 			/*
4693 			 * If we're probing be silent, if this looks like
4694 			 * it's actually an ext4 filesystem.
4695 			 */
4696 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4697 				goto failed_mount;
4698 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4699 				 "to feature incompatibilities");
4700 			goto failed_mount;
4701 		}
4702 	}
4703 
4704 	/*
4705 	 * Check feature flags regardless of the revision level, since we
4706 	 * previously didn't change the revision level when setting the flags,
4707 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4708 	 */
4709 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4710 		goto failed_mount;
4711 
4712 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4713 		ext4_msg(sb, KERN_ERR,
4714 			 "Number of reserved GDT blocks insanely large: %d",
4715 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4716 		goto failed_mount;
4717 	}
4718 
4719 	if (sbi->s_daxdev) {
4720 		if (blocksize == PAGE_SIZE)
4721 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4722 		else
4723 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4724 	}
4725 
4726 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4727 		if (ext4_has_feature_inline_data(sb)) {
4728 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4729 					" that may contain inline data");
4730 			goto failed_mount;
4731 		}
4732 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4733 			ext4_msg(sb, KERN_ERR,
4734 				"DAX unsupported by block device.");
4735 			goto failed_mount;
4736 		}
4737 	}
4738 
4739 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4740 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4741 			 es->s_encryption_level);
4742 		goto failed_mount;
4743 	}
4744 
4745 	if (sb->s_blocksize != blocksize) {
4746 		/*
4747 		 * bh must be released before kill_bdev(), otherwise
4748 		 * it won't be freed and its page also. kill_bdev()
4749 		 * is called by sb_set_blocksize().
4750 		 */
4751 		brelse(bh);
4752 		/* Validate the filesystem blocksize */
4753 		if (!sb_set_blocksize(sb, blocksize)) {
4754 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4755 					blocksize);
4756 			bh = NULL;
4757 			goto failed_mount;
4758 		}
4759 
4760 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4761 		offset = do_div(logical_sb_block, blocksize);
4762 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4763 		if (IS_ERR(bh)) {
4764 			ext4_msg(sb, KERN_ERR,
4765 			       "Can't read superblock on 2nd try");
4766 			ret = PTR_ERR(bh);
4767 			bh = NULL;
4768 			goto failed_mount;
4769 		}
4770 		es = (struct ext4_super_block *)(bh->b_data + offset);
4771 		sbi->s_es = es;
4772 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4773 			ext4_msg(sb, KERN_ERR,
4774 			       "Magic mismatch, very weird!");
4775 			goto failed_mount;
4776 		}
4777 	}
4778 
4779 	has_huge_files = ext4_has_feature_huge_file(sb);
4780 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4781 						      has_huge_files);
4782 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4783 
4784 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4785 	if (ext4_has_feature_64bit(sb)) {
4786 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4787 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4788 		    !is_power_of_2(sbi->s_desc_size)) {
4789 			ext4_msg(sb, KERN_ERR,
4790 			       "unsupported descriptor size %lu",
4791 			       sbi->s_desc_size);
4792 			goto failed_mount;
4793 		}
4794 	} else
4795 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4796 
4797 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4798 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4799 
4800 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4801 	if (sbi->s_inodes_per_block == 0)
4802 		goto cantfind_ext4;
4803 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4804 	    sbi->s_inodes_per_group > blocksize * 8) {
4805 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4806 			 sbi->s_inodes_per_group);
4807 		goto failed_mount;
4808 	}
4809 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4810 					sbi->s_inodes_per_block;
4811 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4812 	sbi->s_sbh = bh;
4813 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
4814 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4815 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4816 
4817 	for (i = 0; i < 4; i++)
4818 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4819 	sbi->s_def_hash_version = es->s_def_hash_version;
4820 	if (ext4_has_feature_dir_index(sb)) {
4821 		i = le32_to_cpu(es->s_flags);
4822 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4823 			sbi->s_hash_unsigned = 3;
4824 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4825 #ifdef __CHAR_UNSIGNED__
4826 			if (!sb_rdonly(sb))
4827 				es->s_flags |=
4828 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4829 			sbi->s_hash_unsigned = 3;
4830 #else
4831 			if (!sb_rdonly(sb))
4832 				es->s_flags |=
4833 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4834 #endif
4835 		}
4836 	}
4837 
4838 	/* Handle clustersize */
4839 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4840 	if (ext4_has_feature_bigalloc(sb)) {
4841 		if (clustersize < blocksize) {
4842 			ext4_msg(sb, KERN_ERR,
4843 				 "cluster size (%d) smaller than "
4844 				 "block size (%d)", clustersize, blocksize);
4845 			goto failed_mount;
4846 		}
4847 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4848 			le32_to_cpu(es->s_log_block_size);
4849 		sbi->s_clusters_per_group =
4850 			le32_to_cpu(es->s_clusters_per_group);
4851 		if (sbi->s_clusters_per_group > blocksize * 8) {
4852 			ext4_msg(sb, KERN_ERR,
4853 				 "#clusters per group too big: %lu",
4854 				 sbi->s_clusters_per_group);
4855 			goto failed_mount;
4856 		}
4857 		if (sbi->s_blocks_per_group !=
4858 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4859 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4860 				 "clusters per group (%lu) inconsistent",
4861 				 sbi->s_blocks_per_group,
4862 				 sbi->s_clusters_per_group);
4863 			goto failed_mount;
4864 		}
4865 	} else {
4866 		if (clustersize != blocksize) {
4867 			ext4_msg(sb, KERN_ERR,
4868 				 "fragment/cluster size (%d) != "
4869 				 "block size (%d)", clustersize, blocksize);
4870 			goto failed_mount;
4871 		}
4872 		if (sbi->s_blocks_per_group > blocksize * 8) {
4873 			ext4_msg(sb, KERN_ERR,
4874 				 "#blocks per group too big: %lu",
4875 				 sbi->s_blocks_per_group);
4876 			goto failed_mount;
4877 		}
4878 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4879 		sbi->s_cluster_bits = 0;
4880 	}
4881 	sbi->s_cluster_ratio = clustersize / blocksize;
4882 
4883 	/* Do we have standard group size of clustersize * 8 blocks ? */
4884 	if (sbi->s_blocks_per_group == clustersize << 3)
4885 		set_opt2(sb, STD_GROUP_SIZE);
4886 
4887 	/*
4888 	 * Test whether we have more sectors than will fit in sector_t,
4889 	 * and whether the max offset is addressable by the page cache.
4890 	 */
4891 	err = generic_check_addressable(sb->s_blocksize_bits,
4892 					ext4_blocks_count(es));
4893 	if (err) {
4894 		ext4_msg(sb, KERN_ERR, "filesystem"
4895 			 " too large to mount safely on this system");
4896 		goto failed_mount;
4897 	}
4898 
4899 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4900 		goto cantfind_ext4;
4901 
4902 	/* check blocks count against device size */
4903 	blocks_count = sb_bdev_nr_blocks(sb);
4904 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4905 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4906 		       "exceeds size of device (%llu blocks)",
4907 		       ext4_blocks_count(es), blocks_count);
4908 		goto failed_mount;
4909 	}
4910 
4911 	/*
4912 	 * It makes no sense for the first data block to be beyond the end
4913 	 * of the filesystem.
4914 	 */
4915 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4916 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4917 			 "block %u is beyond end of filesystem (%llu)",
4918 			 le32_to_cpu(es->s_first_data_block),
4919 			 ext4_blocks_count(es));
4920 		goto failed_mount;
4921 	}
4922 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4923 	    (sbi->s_cluster_ratio == 1)) {
4924 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4925 			 "block is 0 with a 1k block and cluster size");
4926 		goto failed_mount;
4927 	}
4928 
4929 	blocks_count = (ext4_blocks_count(es) -
4930 			le32_to_cpu(es->s_first_data_block) +
4931 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4932 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4933 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4934 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4935 		       "(block count %llu, first data block %u, "
4936 		       "blocks per group %lu)", blocks_count,
4937 		       ext4_blocks_count(es),
4938 		       le32_to_cpu(es->s_first_data_block),
4939 		       EXT4_BLOCKS_PER_GROUP(sb));
4940 		goto failed_mount;
4941 	}
4942 	sbi->s_groups_count = blocks_count;
4943 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4944 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4945 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4946 	    le32_to_cpu(es->s_inodes_count)) {
4947 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4948 			 le32_to_cpu(es->s_inodes_count),
4949 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4950 		ret = -EINVAL;
4951 		goto failed_mount;
4952 	}
4953 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4954 		   EXT4_DESC_PER_BLOCK(sb);
4955 	if (ext4_has_feature_meta_bg(sb)) {
4956 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4957 			ext4_msg(sb, KERN_WARNING,
4958 				 "first meta block group too large: %u "
4959 				 "(group descriptor block count %u)",
4960 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4961 			goto failed_mount;
4962 		}
4963 	}
4964 	rcu_assign_pointer(sbi->s_group_desc,
4965 			   kvmalloc_array(db_count,
4966 					  sizeof(struct buffer_head *),
4967 					  GFP_KERNEL));
4968 	if (sbi->s_group_desc == NULL) {
4969 		ext4_msg(sb, KERN_ERR, "not enough memory");
4970 		ret = -ENOMEM;
4971 		goto failed_mount;
4972 	}
4973 
4974 	bgl_lock_init(sbi->s_blockgroup_lock);
4975 
4976 	/* Pre-read the descriptors into the buffer cache */
4977 	for (i = 0; i < db_count; i++) {
4978 		block = descriptor_loc(sb, logical_sb_block, i);
4979 		ext4_sb_breadahead_unmovable(sb, block);
4980 	}
4981 
4982 	for (i = 0; i < db_count; i++) {
4983 		struct buffer_head *bh;
4984 
4985 		block = descriptor_loc(sb, logical_sb_block, i);
4986 		bh = ext4_sb_bread_unmovable(sb, block);
4987 		if (IS_ERR(bh)) {
4988 			ext4_msg(sb, KERN_ERR,
4989 			       "can't read group descriptor %d", i);
4990 			db_count = i;
4991 			ret = PTR_ERR(bh);
4992 			goto failed_mount2;
4993 		}
4994 		rcu_read_lock();
4995 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4996 		rcu_read_unlock();
4997 	}
4998 	sbi->s_gdb_count = db_count;
4999 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
5000 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
5001 		ret = -EFSCORRUPTED;
5002 		goto failed_mount2;
5003 	}
5004 
5005 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5006 	spin_lock_init(&sbi->s_error_lock);
5007 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5008 
5009 	/* Register extent status tree shrinker */
5010 	if (ext4_es_register_shrinker(sbi))
5011 		goto failed_mount3;
5012 
5013 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5014 	sbi->s_extent_max_zeroout_kb = 32;
5015 
5016 	/*
5017 	 * set up enough so that it can read an inode
5018 	 */
5019 	sb->s_op = &ext4_sops;
5020 	sb->s_export_op = &ext4_export_ops;
5021 	sb->s_xattr = ext4_xattr_handlers;
5022 #ifdef CONFIG_FS_ENCRYPTION
5023 	sb->s_cop = &ext4_cryptops;
5024 #endif
5025 #ifdef CONFIG_FS_VERITY
5026 	sb->s_vop = &ext4_verityops;
5027 #endif
5028 #ifdef CONFIG_QUOTA
5029 	sb->dq_op = &ext4_quota_operations;
5030 	if (ext4_has_feature_quota(sb))
5031 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5032 	else
5033 		sb->s_qcop = &ext4_qctl_operations;
5034 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5035 #endif
5036 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5037 
5038 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5039 	mutex_init(&sbi->s_orphan_lock);
5040 
5041 	/* Initialize fast commit stuff */
5042 	atomic_set(&sbi->s_fc_subtid, 0);
5043 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
5044 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
5045 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
5046 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
5047 	sbi->s_fc_bytes = 0;
5048 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
5049 	sbi->s_fc_ineligible_tid = 0;
5050 	spin_lock_init(&sbi->s_fc_lock);
5051 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
5052 	sbi->s_fc_replay_state.fc_regions = NULL;
5053 	sbi->s_fc_replay_state.fc_regions_size = 0;
5054 	sbi->s_fc_replay_state.fc_regions_used = 0;
5055 	sbi->s_fc_replay_state.fc_regions_valid = 0;
5056 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
5057 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
5058 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
5059 
5060 	sb->s_root = NULL;
5061 
5062 	needs_recovery = (es->s_last_orphan != 0 ||
5063 			  ext4_has_feature_orphan_present(sb) ||
5064 			  ext4_has_feature_journal_needs_recovery(sb));
5065 
5066 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5067 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5068 			goto failed_mount3a;
5069 
5070 	/*
5071 	 * The first inode we look at is the journal inode.  Don't try
5072 	 * root first: it may be modified in the journal!
5073 	 */
5074 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5075 		err = ext4_load_journal(sb, es, ctx->journal_devnum);
5076 		if (err)
5077 			goto failed_mount3a;
5078 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5079 		   ext4_has_feature_journal_needs_recovery(sb)) {
5080 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5081 		       "suppressed and not mounted read-only");
5082 		goto failed_mount_wq;
5083 	} else {
5084 		/* Nojournal mode, all journal mount options are illegal */
5085 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5086 			ext4_msg(sb, KERN_ERR, "can't mount with "
5087 				 "journal_checksum, fs mounted w/o journal");
5088 			goto failed_mount_wq;
5089 		}
5090 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5091 			ext4_msg(sb, KERN_ERR, "can't mount with "
5092 				 "journal_async_commit, fs mounted w/o journal");
5093 			goto failed_mount_wq;
5094 		}
5095 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5096 			ext4_msg(sb, KERN_ERR, "can't mount with "
5097 				 "commit=%lu, fs mounted w/o journal",
5098 				 sbi->s_commit_interval / HZ);
5099 			goto failed_mount_wq;
5100 		}
5101 		if (EXT4_MOUNT_DATA_FLAGS &
5102 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5103 			ext4_msg(sb, KERN_ERR, "can't mount with "
5104 				 "data=, fs mounted w/o journal");
5105 			goto failed_mount_wq;
5106 		}
5107 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5108 		clear_opt(sb, JOURNAL_CHECKSUM);
5109 		clear_opt(sb, DATA_FLAGS);
5110 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5111 		sbi->s_journal = NULL;
5112 		needs_recovery = 0;
5113 		goto no_journal;
5114 	}
5115 
5116 	if (ext4_has_feature_64bit(sb) &&
5117 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5118 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
5119 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
5120 		goto failed_mount_wq;
5121 	}
5122 
5123 	if (!set_journal_csum_feature_set(sb)) {
5124 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
5125 			 "feature set");
5126 		goto failed_mount_wq;
5127 	}
5128 
5129 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
5130 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5131 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
5132 		ext4_msg(sb, KERN_ERR,
5133 			"Failed to set fast commit journal feature");
5134 		goto failed_mount_wq;
5135 	}
5136 
5137 	/* We have now updated the journal if required, so we can
5138 	 * validate the data journaling mode. */
5139 	switch (test_opt(sb, DATA_FLAGS)) {
5140 	case 0:
5141 		/* No mode set, assume a default based on the journal
5142 		 * capabilities: ORDERED_DATA if the journal can
5143 		 * cope, else JOURNAL_DATA
5144 		 */
5145 		if (jbd2_journal_check_available_features
5146 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5147 			set_opt(sb, ORDERED_DATA);
5148 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
5149 		} else {
5150 			set_opt(sb, JOURNAL_DATA);
5151 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
5152 		}
5153 		break;
5154 
5155 	case EXT4_MOUNT_ORDERED_DATA:
5156 	case EXT4_MOUNT_WRITEBACK_DATA:
5157 		if (!jbd2_journal_check_available_features
5158 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5159 			ext4_msg(sb, KERN_ERR, "Journal does not support "
5160 			       "requested data journaling mode");
5161 			goto failed_mount_wq;
5162 		}
5163 		break;
5164 	default:
5165 		break;
5166 	}
5167 
5168 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5169 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5170 		ext4_msg(sb, KERN_ERR, "can't mount with "
5171 			"journal_async_commit in data=ordered mode");
5172 		goto failed_mount_wq;
5173 	}
5174 
5175 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5176 
5177 	sbi->s_journal->j_submit_inode_data_buffers =
5178 		ext4_journal_submit_inode_data_buffers;
5179 	sbi->s_journal->j_finish_inode_data_buffers =
5180 		ext4_journal_finish_inode_data_buffers;
5181 
5182 no_journal:
5183 	if (!test_opt(sb, NO_MBCACHE)) {
5184 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5185 		if (!sbi->s_ea_block_cache) {
5186 			ext4_msg(sb, KERN_ERR,
5187 				 "Failed to create ea_block_cache");
5188 			goto failed_mount_wq;
5189 		}
5190 
5191 		if (ext4_has_feature_ea_inode(sb)) {
5192 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5193 			if (!sbi->s_ea_inode_cache) {
5194 				ext4_msg(sb, KERN_ERR,
5195 					 "Failed to create ea_inode_cache");
5196 				goto failed_mount_wq;
5197 			}
5198 		}
5199 	}
5200 
5201 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
5202 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5203 		goto failed_mount_wq;
5204 	}
5205 
5206 	/*
5207 	 * Get the # of file system overhead blocks from the
5208 	 * superblock if present.
5209 	 */
5210 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5211 	/* ignore the precalculated value if it is ridiculous */
5212 	if (sbi->s_overhead > ext4_blocks_count(es))
5213 		sbi->s_overhead = 0;
5214 	/*
5215 	 * If the bigalloc feature is not enabled recalculating the
5216 	 * overhead doesn't take long, so we might as well just redo
5217 	 * it to make sure we are using the correct value.
5218 	 */
5219 	if (!ext4_has_feature_bigalloc(sb))
5220 		sbi->s_overhead = 0;
5221 	if (sbi->s_overhead == 0) {
5222 		err = ext4_calculate_overhead(sb);
5223 		if (err)
5224 			goto failed_mount_wq;
5225 	}
5226 
5227 	/*
5228 	 * The maximum number of concurrent works can be high and
5229 	 * concurrency isn't really necessary.  Limit it to 1.
5230 	 */
5231 	EXT4_SB(sb)->rsv_conversion_wq =
5232 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5233 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5234 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5235 		ret = -ENOMEM;
5236 		goto failed_mount4;
5237 	}
5238 
5239 	/*
5240 	 * The jbd2_journal_load will have done any necessary log recovery,
5241 	 * so we can safely mount the rest of the filesystem now.
5242 	 */
5243 
5244 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5245 	if (IS_ERR(root)) {
5246 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5247 		ret = PTR_ERR(root);
5248 		root = NULL;
5249 		goto failed_mount4;
5250 	}
5251 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5252 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5253 		iput(root);
5254 		goto failed_mount4;
5255 	}
5256 
5257 	sb->s_root = d_make_root(root);
5258 	if (!sb->s_root) {
5259 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5260 		ret = -ENOMEM;
5261 		goto failed_mount4;
5262 	}
5263 
5264 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5265 	if (ret == -EROFS) {
5266 		sb->s_flags |= SB_RDONLY;
5267 		ret = 0;
5268 	} else if (ret)
5269 		goto failed_mount4a;
5270 
5271 	ext4_set_resv_clusters(sb);
5272 
5273 	if (test_opt(sb, BLOCK_VALIDITY)) {
5274 		err = ext4_setup_system_zone(sb);
5275 		if (err) {
5276 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5277 				 "zone (%d)", err);
5278 			goto failed_mount4a;
5279 		}
5280 	}
5281 	ext4_fc_replay_cleanup(sb);
5282 
5283 	ext4_ext_init(sb);
5284 
5285 	/*
5286 	 * Enable optimize_scan if number of groups is > threshold. This can be
5287 	 * turned off by passing "mb_optimize_scan=0". This can also be
5288 	 * turned on forcefully by passing "mb_optimize_scan=1".
5289 	 */
5290 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5291 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5292 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5293 		else
5294 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5295 	}
5296 
5297 	err = ext4_mb_init(sb);
5298 	if (err) {
5299 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5300 			 err);
5301 		goto failed_mount5;
5302 	}
5303 
5304 	/*
5305 	 * We can only set up the journal commit callback once
5306 	 * mballoc is initialized
5307 	 */
5308 	if (sbi->s_journal)
5309 		sbi->s_journal->j_commit_callback =
5310 			ext4_journal_commit_callback;
5311 
5312 	block = ext4_count_free_clusters(sb);
5313 	ext4_free_blocks_count_set(sbi->s_es,
5314 				   EXT4_C2B(sbi, block));
5315 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5316 				  GFP_KERNEL);
5317 	if (!err) {
5318 		unsigned long freei = ext4_count_free_inodes(sb);
5319 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5320 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5321 					  GFP_KERNEL);
5322 	}
5323 	if (!err)
5324 		err = percpu_counter_init(&sbi->s_dirs_counter,
5325 					  ext4_count_dirs(sb), GFP_KERNEL);
5326 	if (!err)
5327 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5328 					  GFP_KERNEL);
5329 	if (!err)
5330 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5331 					  GFP_KERNEL);
5332 	if (!err)
5333 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5334 
5335 	if (err) {
5336 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5337 		goto failed_mount6;
5338 	}
5339 
5340 	if (ext4_has_feature_flex_bg(sb))
5341 		if (!ext4_fill_flex_info(sb)) {
5342 			ext4_msg(sb, KERN_ERR,
5343 			       "unable to initialize "
5344 			       "flex_bg meta info!");
5345 			ret = -ENOMEM;
5346 			goto failed_mount6;
5347 		}
5348 
5349 	err = ext4_register_li_request(sb, first_not_zeroed);
5350 	if (err)
5351 		goto failed_mount6;
5352 
5353 	err = ext4_register_sysfs(sb);
5354 	if (err)
5355 		goto failed_mount7;
5356 
5357 	err = ext4_init_orphan_info(sb);
5358 	if (err)
5359 		goto failed_mount8;
5360 #ifdef CONFIG_QUOTA
5361 	/* Enable quota usage during mount. */
5362 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5363 		err = ext4_enable_quotas(sb);
5364 		if (err)
5365 			goto failed_mount9;
5366 	}
5367 #endif  /* CONFIG_QUOTA */
5368 
5369 	/*
5370 	 * Save the original bdev mapping's wb_err value which could be
5371 	 * used to detect the metadata async write error.
5372 	 */
5373 	spin_lock_init(&sbi->s_bdev_wb_lock);
5374 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5375 				 &sbi->s_bdev_wb_err);
5376 	sb->s_bdev->bd_super = sb;
5377 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5378 	ext4_orphan_cleanup(sb, es);
5379 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5380 	/*
5381 	 * Update the checksum after updating free space/inode counters and
5382 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5383 	 * checksum in the buffer cache until it is written out and
5384 	 * e2fsprogs programs trying to open a file system immediately
5385 	 * after it is mounted can fail.
5386 	 */
5387 	ext4_superblock_csum_set(sb);
5388 	if (needs_recovery) {
5389 		ext4_msg(sb, KERN_INFO, "recovery complete");
5390 		err = ext4_mark_recovery_complete(sb, es);
5391 		if (err)
5392 			goto failed_mount9;
5393 	}
5394 
5395 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5396 		ext4_msg(sb, KERN_WARNING,
5397 			 "mounting with \"discard\" option, but the device does not support discard");
5398 
5399 	if (es->s_error_count)
5400 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5401 
5402 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5403 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5404 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5405 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5406 	atomic_set(&sbi->s_warning_count, 0);
5407 	atomic_set(&sbi->s_msg_count, 0);
5408 
5409 	return 0;
5410 
5411 cantfind_ext4:
5412 	if (!silent)
5413 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5414 	goto failed_mount;
5415 
5416 failed_mount9:
5417 	ext4_release_orphan_info(sb);
5418 failed_mount8:
5419 	ext4_unregister_sysfs(sb);
5420 	kobject_put(&sbi->s_kobj);
5421 failed_mount7:
5422 	ext4_unregister_li_request(sb);
5423 failed_mount6:
5424 	ext4_mb_release(sb);
5425 	rcu_read_lock();
5426 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5427 	if (flex_groups) {
5428 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5429 			kvfree(flex_groups[i]);
5430 		kvfree(flex_groups);
5431 	}
5432 	rcu_read_unlock();
5433 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5434 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5435 	percpu_counter_destroy(&sbi->s_dirs_counter);
5436 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5437 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5438 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5439 failed_mount5:
5440 	ext4_ext_release(sb);
5441 	ext4_release_system_zone(sb);
5442 failed_mount4a:
5443 	dput(sb->s_root);
5444 	sb->s_root = NULL;
5445 failed_mount4:
5446 	ext4_msg(sb, KERN_ERR, "mount failed");
5447 	if (EXT4_SB(sb)->rsv_conversion_wq)
5448 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5449 failed_mount_wq:
5450 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5451 	sbi->s_ea_inode_cache = NULL;
5452 
5453 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5454 	sbi->s_ea_block_cache = NULL;
5455 
5456 	if (sbi->s_journal) {
5457 		/* flush s_error_work before journal destroy. */
5458 		flush_work(&sbi->s_error_work);
5459 		jbd2_journal_destroy(sbi->s_journal);
5460 		sbi->s_journal = NULL;
5461 	}
5462 failed_mount3a:
5463 	ext4_es_unregister_shrinker(sbi);
5464 failed_mount3:
5465 	/* flush s_error_work before sbi destroy */
5466 	flush_work(&sbi->s_error_work);
5467 	del_timer_sync(&sbi->s_err_report);
5468 	ext4_stop_mmpd(sbi);
5469 failed_mount2:
5470 	rcu_read_lock();
5471 	group_desc = rcu_dereference(sbi->s_group_desc);
5472 	for (i = 0; i < db_count; i++)
5473 		brelse(group_desc[i]);
5474 	kvfree(group_desc);
5475 	rcu_read_unlock();
5476 failed_mount:
5477 	if (sbi->s_chksum_driver)
5478 		crypto_free_shash(sbi->s_chksum_driver);
5479 
5480 #if IS_ENABLED(CONFIG_UNICODE)
5481 	utf8_unload(sb->s_encoding);
5482 #endif
5483 
5484 #ifdef CONFIG_QUOTA
5485 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5486 		kfree(get_qf_name(sb, sbi, i));
5487 #endif
5488 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5489 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5490 	brelse(bh);
5491 	ext4_blkdev_remove(sbi);
5492 out_fail:
5493 	sb->s_fs_info = NULL;
5494 	return err ? err : ret;
5495 }
5496 
5497 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5498 {
5499 	struct ext4_fs_context *ctx = fc->fs_private;
5500 	struct ext4_sb_info *sbi;
5501 	const char *descr;
5502 	int ret;
5503 
5504 	sbi = ext4_alloc_sbi(sb);
5505 	if (!sbi)
5506 		return -ENOMEM;
5507 
5508 	fc->s_fs_info = sbi;
5509 
5510 	/* Cleanup superblock name */
5511 	strreplace(sb->s_id, '/', '!');
5512 
5513 	sbi->s_sb_block = 1;	/* Default super block location */
5514 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5515 		sbi->s_sb_block = ctx->s_sb_block;
5516 
5517 	ret = __ext4_fill_super(fc, sb);
5518 	if (ret < 0)
5519 		goto free_sbi;
5520 
5521 	if (sbi->s_journal) {
5522 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5523 			descr = " journalled data mode";
5524 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5525 			descr = " ordered data mode";
5526 		else
5527 			descr = " writeback data mode";
5528 	} else
5529 		descr = "out journal";
5530 
5531 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5532 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5533 			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
5534 
5535 	/* Update the s_overhead_clusters if necessary */
5536 	ext4_update_overhead(sb, false);
5537 	return 0;
5538 
5539 free_sbi:
5540 	ext4_free_sbi(sbi);
5541 	fc->s_fs_info = NULL;
5542 	return ret;
5543 }
5544 
5545 static int ext4_get_tree(struct fs_context *fc)
5546 {
5547 	return get_tree_bdev(fc, ext4_fill_super);
5548 }
5549 
5550 /*
5551  * Setup any per-fs journal parameters now.  We'll do this both on
5552  * initial mount, once the journal has been initialised but before we've
5553  * done any recovery; and again on any subsequent remount.
5554  */
5555 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5556 {
5557 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5558 
5559 	journal->j_commit_interval = sbi->s_commit_interval;
5560 	journal->j_min_batch_time = sbi->s_min_batch_time;
5561 	journal->j_max_batch_time = sbi->s_max_batch_time;
5562 	ext4_fc_init(sb, journal);
5563 
5564 	write_lock(&journal->j_state_lock);
5565 	if (test_opt(sb, BARRIER))
5566 		journal->j_flags |= JBD2_BARRIER;
5567 	else
5568 		journal->j_flags &= ~JBD2_BARRIER;
5569 	if (test_opt(sb, DATA_ERR_ABORT))
5570 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5571 	else
5572 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5573 	write_unlock(&journal->j_state_lock);
5574 }
5575 
5576 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5577 					     unsigned int journal_inum)
5578 {
5579 	struct inode *journal_inode;
5580 
5581 	/*
5582 	 * Test for the existence of a valid inode on disk.  Bad things
5583 	 * happen if we iget() an unused inode, as the subsequent iput()
5584 	 * will try to delete it.
5585 	 */
5586 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5587 	if (IS_ERR(journal_inode)) {
5588 		ext4_msg(sb, KERN_ERR, "no journal found");
5589 		return NULL;
5590 	}
5591 	if (!journal_inode->i_nlink) {
5592 		make_bad_inode(journal_inode);
5593 		iput(journal_inode);
5594 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5595 		return NULL;
5596 	}
5597 
5598 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5599 		  journal_inode, journal_inode->i_size);
5600 	if (!S_ISREG(journal_inode->i_mode)) {
5601 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5602 		iput(journal_inode);
5603 		return NULL;
5604 	}
5605 	return journal_inode;
5606 }
5607 
5608 static journal_t *ext4_get_journal(struct super_block *sb,
5609 				   unsigned int journal_inum)
5610 {
5611 	struct inode *journal_inode;
5612 	journal_t *journal;
5613 
5614 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5615 		return NULL;
5616 
5617 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5618 	if (!journal_inode)
5619 		return NULL;
5620 
5621 	journal = jbd2_journal_init_inode(journal_inode);
5622 	if (!journal) {
5623 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5624 		iput(journal_inode);
5625 		return NULL;
5626 	}
5627 	journal->j_private = sb;
5628 	ext4_init_journal_params(sb, journal);
5629 	return journal;
5630 }
5631 
5632 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5633 				       dev_t j_dev)
5634 {
5635 	struct buffer_head *bh;
5636 	journal_t *journal;
5637 	ext4_fsblk_t start;
5638 	ext4_fsblk_t len;
5639 	int hblock, blocksize;
5640 	ext4_fsblk_t sb_block;
5641 	unsigned long offset;
5642 	struct ext4_super_block *es;
5643 	struct block_device *bdev;
5644 
5645 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5646 		return NULL;
5647 
5648 	bdev = ext4_blkdev_get(j_dev, sb);
5649 	if (bdev == NULL)
5650 		return NULL;
5651 
5652 	blocksize = sb->s_blocksize;
5653 	hblock = bdev_logical_block_size(bdev);
5654 	if (blocksize < hblock) {
5655 		ext4_msg(sb, KERN_ERR,
5656 			"blocksize too small for journal device");
5657 		goto out_bdev;
5658 	}
5659 
5660 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5661 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5662 	set_blocksize(bdev, blocksize);
5663 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5664 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5665 		       "external journal");
5666 		goto out_bdev;
5667 	}
5668 
5669 	es = (struct ext4_super_block *) (bh->b_data + offset);
5670 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5671 	    !(le32_to_cpu(es->s_feature_incompat) &
5672 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5673 		ext4_msg(sb, KERN_ERR, "external journal has "
5674 					"bad superblock");
5675 		brelse(bh);
5676 		goto out_bdev;
5677 	}
5678 
5679 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5680 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5681 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5682 		ext4_msg(sb, KERN_ERR, "external journal has "
5683 				       "corrupt superblock");
5684 		brelse(bh);
5685 		goto out_bdev;
5686 	}
5687 
5688 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5689 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5690 		brelse(bh);
5691 		goto out_bdev;
5692 	}
5693 
5694 	len = ext4_blocks_count(es);
5695 	start = sb_block + 1;
5696 	brelse(bh);	/* we're done with the superblock */
5697 
5698 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5699 					start, len, blocksize);
5700 	if (!journal) {
5701 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5702 		goto out_bdev;
5703 	}
5704 	journal->j_private = sb;
5705 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5706 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5707 		goto out_journal;
5708 	}
5709 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5710 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5711 					"user (unsupported) - %d",
5712 			be32_to_cpu(journal->j_superblock->s_nr_users));
5713 		goto out_journal;
5714 	}
5715 	EXT4_SB(sb)->s_journal_bdev = bdev;
5716 	ext4_init_journal_params(sb, journal);
5717 	return journal;
5718 
5719 out_journal:
5720 	jbd2_journal_destroy(journal);
5721 out_bdev:
5722 	ext4_blkdev_put(bdev);
5723 	return NULL;
5724 }
5725 
5726 static int ext4_load_journal(struct super_block *sb,
5727 			     struct ext4_super_block *es,
5728 			     unsigned long journal_devnum)
5729 {
5730 	journal_t *journal;
5731 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5732 	dev_t journal_dev;
5733 	int err = 0;
5734 	int really_read_only;
5735 	int journal_dev_ro;
5736 
5737 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5738 		return -EFSCORRUPTED;
5739 
5740 	if (journal_devnum &&
5741 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5742 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5743 			"numbers have changed");
5744 		journal_dev = new_decode_dev(journal_devnum);
5745 	} else
5746 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5747 
5748 	if (journal_inum && journal_dev) {
5749 		ext4_msg(sb, KERN_ERR,
5750 			 "filesystem has both journal inode and journal device!");
5751 		return -EINVAL;
5752 	}
5753 
5754 	if (journal_inum) {
5755 		journal = ext4_get_journal(sb, journal_inum);
5756 		if (!journal)
5757 			return -EINVAL;
5758 	} else {
5759 		journal = ext4_get_dev_journal(sb, journal_dev);
5760 		if (!journal)
5761 			return -EINVAL;
5762 	}
5763 
5764 	journal_dev_ro = bdev_read_only(journal->j_dev);
5765 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5766 
5767 	if (journal_dev_ro && !sb_rdonly(sb)) {
5768 		ext4_msg(sb, KERN_ERR,
5769 			 "journal device read-only, try mounting with '-o ro'");
5770 		err = -EROFS;
5771 		goto err_out;
5772 	}
5773 
5774 	/*
5775 	 * Are we loading a blank journal or performing recovery after a
5776 	 * crash?  For recovery, we need to check in advance whether we
5777 	 * can get read-write access to the device.
5778 	 */
5779 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5780 		if (sb_rdonly(sb)) {
5781 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5782 					"required on readonly filesystem");
5783 			if (really_read_only) {
5784 				ext4_msg(sb, KERN_ERR, "write access "
5785 					"unavailable, cannot proceed "
5786 					"(try mounting with noload)");
5787 				err = -EROFS;
5788 				goto err_out;
5789 			}
5790 			ext4_msg(sb, KERN_INFO, "write access will "
5791 			       "be enabled during recovery");
5792 		}
5793 	}
5794 
5795 	if (!(journal->j_flags & JBD2_BARRIER))
5796 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5797 
5798 	if (!ext4_has_feature_journal_needs_recovery(sb))
5799 		err = jbd2_journal_wipe(journal, !really_read_only);
5800 	if (!err) {
5801 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5802 		if (save)
5803 			memcpy(save, ((char *) es) +
5804 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5805 		err = jbd2_journal_load(journal);
5806 		if (save)
5807 			memcpy(((char *) es) + EXT4_S_ERR_START,
5808 			       save, EXT4_S_ERR_LEN);
5809 		kfree(save);
5810 	}
5811 
5812 	if (err) {
5813 		ext4_msg(sb, KERN_ERR, "error loading journal");
5814 		goto err_out;
5815 	}
5816 
5817 	EXT4_SB(sb)->s_journal = journal;
5818 	err = ext4_clear_journal_err(sb, es);
5819 	if (err) {
5820 		EXT4_SB(sb)->s_journal = NULL;
5821 		jbd2_journal_destroy(journal);
5822 		return err;
5823 	}
5824 
5825 	if (!really_read_only && journal_devnum &&
5826 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5827 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5828 
5829 		/* Make sure we flush the recovery flag to disk. */
5830 		ext4_commit_super(sb);
5831 	}
5832 
5833 	return 0;
5834 
5835 err_out:
5836 	jbd2_journal_destroy(journal);
5837 	return err;
5838 }
5839 
5840 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5841 static void ext4_update_super(struct super_block *sb)
5842 {
5843 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5844 	struct ext4_super_block *es = sbi->s_es;
5845 	struct buffer_head *sbh = sbi->s_sbh;
5846 
5847 	lock_buffer(sbh);
5848 	/*
5849 	 * If the file system is mounted read-only, don't update the
5850 	 * superblock write time.  This avoids updating the superblock
5851 	 * write time when we are mounting the root file system
5852 	 * read/only but we need to replay the journal; at that point,
5853 	 * for people who are east of GMT and who make their clock
5854 	 * tick in localtime for Windows bug-for-bug compatibility,
5855 	 * the clock is set in the future, and this will cause e2fsck
5856 	 * to complain and force a full file system check.
5857 	 */
5858 	if (!(sb->s_flags & SB_RDONLY))
5859 		ext4_update_tstamp(es, s_wtime);
5860 	es->s_kbytes_written =
5861 		cpu_to_le64(sbi->s_kbytes_written +
5862 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5863 		      sbi->s_sectors_written_start) >> 1));
5864 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5865 		ext4_free_blocks_count_set(es,
5866 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5867 				&sbi->s_freeclusters_counter)));
5868 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5869 		es->s_free_inodes_count =
5870 			cpu_to_le32(percpu_counter_sum_positive(
5871 				&sbi->s_freeinodes_counter));
5872 	/* Copy error information to the on-disk superblock */
5873 	spin_lock(&sbi->s_error_lock);
5874 	if (sbi->s_add_error_count > 0) {
5875 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5876 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5877 			__ext4_update_tstamp(&es->s_first_error_time,
5878 					     &es->s_first_error_time_hi,
5879 					     sbi->s_first_error_time);
5880 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5881 				sizeof(es->s_first_error_func));
5882 			es->s_first_error_line =
5883 				cpu_to_le32(sbi->s_first_error_line);
5884 			es->s_first_error_ino =
5885 				cpu_to_le32(sbi->s_first_error_ino);
5886 			es->s_first_error_block =
5887 				cpu_to_le64(sbi->s_first_error_block);
5888 			es->s_first_error_errcode =
5889 				ext4_errno_to_code(sbi->s_first_error_code);
5890 		}
5891 		__ext4_update_tstamp(&es->s_last_error_time,
5892 				     &es->s_last_error_time_hi,
5893 				     sbi->s_last_error_time);
5894 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5895 			sizeof(es->s_last_error_func));
5896 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5897 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5898 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5899 		es->s_last_error_errcode =
5900 				ext4_errno_to_code(sbi->s_last_error_code);
5901 		/*
5902 		 * Start the daily error reporting function if it hasn't been
5903 		 * started already
5904 		 */
5905 		if (!es->s_error_count)
5906 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5907 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5908 		sbi->s_add_error_count = 0;
5909 	}
5910 	spin_unlock(&sbi->s_error_lock);
5911 
5912 	ext4_superblock_csum_set(sb);
5913 	unlock_buffer(sbh);
5914 }
5915 
5916 static int ext4_commit_super(struct super_block *sb)
5917 {
5918 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5919 
5920 	if (!sbh)
5921 		return -EINVAL;
5922 	if (block_device_ejected(sb))
5923 		return -ENODEV;
5924 
5925 	ext4_update_super(sb);
5926 
5927 	lock_buffer(sbh);
5928 	/* Buffer got discarded which means block device got invalidated */
5929 	if (!buffer_mapped(sbh)) {
5930 		unlock_buffer(sbh);
5931 		return -EIO;
5932 	}
5933 
5934 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5935 		/*
5936 		 * Oh, dear.  A previous attempt to write the
5937 		 * superblock failed.  This could happen because the
5938 		 * USB device was yanked out.  Or it could happen to
5939 		 * be a transient write error and maybe the block will
5940 		 * be remapped.  Nothing we can do but to retry the
5941 		 * write and hope for the best.
5942 		 */
5943 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5944 		       "superblock detected");
5945 		clear_buffer_write_io_error(sbh);
5946 		set_buffer_uptodate(sbh);
5947 	}
5948 	get_bh(sbh);
5949 	/* Clear potential dirty bit if it was journalled update */
5950 	clear_buffer_dirty(sbh);
5951 	sbh->b_end_io = end_buffer_write_sync;
5952 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
5953 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
5954 	wait_on_buffer(sbh);
5955 	if (buffer_write_io_error(sbh)) {
5956 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
5957 		       "superblock");
5958 		clear_buffer_write_io_error(sbh);
5959 		set_buffer_uptodate(sbh);
5960 		return -EIO;
5961 	}
5962 	return 0;
5963 }
5964 
5965 /*
5966  * Have we just finished recovery?  If so, and if we are mounting (or
5967  * remounting) the filesystem readonly, then we will end up with a
5968  * consistent fs on disk.  Record that fact.
5969  */
5970 static int ext4_mark_recovery_complete(struct super_block *sb,
5971 				       struct ext4_super_block *es)
5972 {
5973 	int err;
5974 	journal_t *journal = EXT4_SB(sb)->s_journal;
5975 
5976 	if (!ext4_has_feature_journal(sb)) {
5977 		if (journal != NULL) {
5978 			ext4_error(sb, "Journal got removed while the fs was "
5979 				   "mounted!");
5980 			return -EFSCORRUPTED;
5981 		}
5982 		return 0;
5983 	}
5984 	jbd2_journal_lock_updates(journal);
5985 	err = jbd2_journal_flush(journal, 0);
5986 	if (err < 0)
5987 		goto out;
5988 
5989 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
5990 	    ext4_has_feature_orphan_present(sb))) {
5991 		if (!ext4_orphan_file_empty(sb)) {
5992 			ext4_error(sb, "Orphan file not empty on read-only fs.");
5993 			err = -EFSCORRUPTED;
5994 			goto out;
5995 		}
5996 		ext4_clear_feature_journal_needs_recovery(sb);
5997 		ext4_clear_feature_orphan_present(sb);
5998 		ext4_commit_super(sb);
5999 	}
6000 out:
6001 	jbd2_journal_unlock_updates(journal);
6002 	return err;
6003 }
6004 
6005 /*
6006  * If we are mounting (or read-write remounting) a filesystem whose journal
6007  * has recorded an error from a previous lifetime, move that error to the
6008  * main filesystem now.
6009  */
6010 static int ext4_clear_journal_err(struct super_block *sb,
6011 				   struct ext4_super_block *es)
6012 {
6013 	journal_t *journal;
6014 	int j_errno;
6015 	const char *errstr;
6016 
6017 	if (!ext4_has_feature_journal(sb)) {
6018 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6019 		return -EFSCORRUPTED;
6020 	}
6021 
6022 	journal = EXT4_SB(sb)->s_journal;
6023 
6024 	/*
6025 	 * Now check for any error status which may have been recorded in the
6026 	 * journal by a prior ext4_error() or ext4_abort()
6027 	 */
6028 
6029 	j_errno = jbd2_journal_errno(journal);
6030 	if (j_errno) {
6031 		char nbuf[16];
6032 
6033 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6034 		ext4_warning(sb, "Filesystem error recorded "
6035 			     "from previous mount: %s", errstr);
6036 		ext4_warning(sb, "Marking fs in need of filesystem check.");
6037 
6038 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6039 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6040 		ext4_commit_super(sb);
6041 
6042 		jbd2_journal_clear_err(journal);
6043 		jbd2_journal_update_sb_errno(journal);
6044 	}
6045 	return 0;
6046 }
6047 
6048 /*
6049  * Force the running and committing transactions to commit,
6050  * and wait on the commit.
6051  */
6052 int ext4_force_commit(struct super_block *sb)
6053 {
6054 	journal_t *journal;
6055 
6056 	if (sb_rdonly(sb))
6057 		return 0;
6058 
6059 	journal = EXT4_SB(sb)->s_journal;
6060 	return ext4_journal_force_commit(journal);
6061 }
6062 
6063 static int ext4_sync_fs(struct super_block *sb, int wait)
6064 {
6065 	int ret = 0;
6066 	tid_t target;
6067 	bool needs_barrier = false;
6068 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6069 
6070 	if (unlikely(ext4_forced_shutdown(sbi)))
6071 		return 0;
6072 
6073 	trace_ext4_sync_fs(sb, wait);
6074 	flush_workqueue(sbi->rsv_conversion_wq);
6075 	/*
6076 	 * Writeback quota in non-journalled quota case - journalled quota has
6077 	 * no dirty dquots
6078 	 */
6079 	dquot_writeback_dquots(sb, -1);
6080 	/*
6081 	 * Data writeback is possible w/o journal transaction, so barrier must
6082 	 * being sent at the end of the function. But we can skip it if
6083 	 * transaction_commit will do it for us.
6084 	 */
6085 	if (sbi->s_journal) {
6086 		target = jbd2_get_latest_transaction(sbi->s_journal);
6087 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6088 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6089 			needs_barrier = true;
6090 
6091 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6092 			if (wait)
6093 				ret = jbd2_log_wait_commit(sbi->s_journal,
6094 							   target);
6095 		}
6096 	} else if (wait && test_opt(sb, BARRIER))
6097 		needs_barrier = true;
6098 	if (needs_barrier) {
6099 		int err;
6100 		err = blkdev_issue_flush(sb->s_bdev);
6101 		if (!ret)
6102 			ret = err;
6103 	}
6104 
6105 	return ret;
6106 }
6107 
6108 /*
6109  * LVM calls this function before a (read-only) snapshot is created.  This
6110  * gives us a chance to flush the journal completely and mark the fs clean.
6111  *
6112  * Note that only this function cannot bring a filesystem to be in a clean
6113  * state independently. It relies on upper layer to stop all data & metadata
6114  * modifications.
6115  */
6116 static int ext4_freeze(struct super_block *sb)
6117 {
6118 	int error = 0;
6119 	journal_t *journal;
6120 
6121 	if (sb_rdonly(sb))
6122 		return 0;
6123 
6124 	journal = EXT4_SB(sb)->s_journal;
6125 
6126 	if (journal) {
6127 		/* Now we set up the journal barrier. */
6128 		jbd2_journal_lock_updates(journal);
6129 
6130 		/*
6131 		 * Don't clear the needs_recovery flag if we failed to
6132 		 * flush the journal.
6133 		 */
6134 		error = jbd2_journal_flush(journal, 0);
6135 		if (error < 0)
6136 			goto out;
6137 
6138 		/* Journal blocked and flushed, clear needs_recovery flag. */
6139 		ext4_clear_feature_journal_needs_recovery(sb);
6140 		if (ext4_orphan_file_empty(sb))
6141 			ext4_clear_feature_orphan_present(sb);
6142 	}
6143 
6144 	error = ext4_commit_super(sb);
6145 out:
6146 	if (journal)
6147 		/* we rely on upper layer to stop further updates */
6148 		jbd2_journal_unlock_updates(journal);
6149 	return error;
6150 }
6151 
6152 /*
6153  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6154  * flag here, even though the filesystem is not technically dirty yet.
6155  */
6156 static int ext4_unfreeze(struct super_block *sb)
6157 {
6158 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6159 		return 0;
6160 
6161 	if (EXT4_SB(sb)->s_journal) {
6162 		/* Reset the needs_recovery flag before the fs is unlocked. */
6163 		ext4_set_feature_journal_needs_recovery(sb);
6164 		if (ext4_has_feature_orphan_file(sb))
6165 			ext4_set_feature_orphan_present(sb);
6166 	}
6167 
6168 	ext4_commit_super(sb);
6169 	return 0;
6170 }
6171 
6172 /*
6173  * Structure to save mount options for ext4_remount's benefit
6174  */
6175 struct ext4_mount_options {
6176 	unsigned long s_mount_opt;
6177 	unsigned long s_mount_opt2;
6178 	kuid_t s_resuid;
6179 	kgid_t s_resgid;
6180 	unsigned long s_commit_interval;
6181 	u32 s_min_batch_time, s_max_batch_time;
6182 #ifdef CONFIG_QUOTA
6183 	int s_jquota_fmt;
6184 	char *s_qf_names[EXT4_MAXQUOTAS];
6185 #endif
6186 };
6187 
6188 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6189 {
6190 	struct ext4_fs_context *ctx = fc->fs_private;
6191 	struct ext4_super_block *es;
6192 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6193 	unsigned long old_sb_flags;
6194 	struct ext4_mount_options old_opts;
6195 	ext4_group_t g;
6196 	int err = 0;
6197 #ifdef CONFIG_QUOTA
6198 	int enable_quota = 0;
6199 	int i, j;
6200 	char *to_free[EXT4_MAXQUOTAS];
6201 #endif
6202 
6203 
6204 	/* Store the original options */
6205 	old_sb_flags = sb->s_flags;
6206 	old_opts.s_mount_opt = sbi->s_mount_opt;
6207 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6208 	old_opts.s_resuid = sbi->s_resuid;
6209 	old_opts.s_resgid = sbi->s_resgid;
6210 	old_opts.s_commit_interval = sbi->s_commit_interval;
6211 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6212 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6213 #ifdef CONFIG_QUOTA
6214 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6215 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6216 		if (sbi->s_qf_names[i]) {
6217 			char *qf_name = get_qf_name(sb, sbi, i);
6218 
6219 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6220 			if (!old_opts.s_qf_names[i]) {
6221 				for (j = 0; j < i; j++)
6222 					kfree(old_opts.s_qf_names[j]);
6223 				return -ENOMEM;
6224 			}
6225 		} else
6226 			old_opts.s_qf_names[i] = NULL;
6227 #endif
6228 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6229 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6230 			ctx->journal_ioprio =
6231 				sbi->s_journal->j_task->io_context->ioprio;
6232 		else
6233 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6234 
6235 	}
6236 
6237 	ext4_apply_options(fc, sb);
6238 
6239 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6240 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6241 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6242 			 "during remount not supported; ignoring");
6243 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6244 	}
6245 
6246 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6247 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6248 			ext4_msg(sb, KERN_ERR, "can't mount with "
6249 				 "both data=journal and delalloc");
6250 			err = -EINVAL;
6251 			goto restore_opts;
6252 		}
6253 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6254 			ext4_msg(sb, KERN_ERR, "can't mount with "
6255 				 "both data=journal and dioread_nolock");
6256 			err = -EINVAL;
6257 			goto restore_opts;
6258 		}
6259 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6260 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6261 			ext4_msg(sb, KERN_ERR, "can't mount with "
6262 				"journal_async_commit in data=ordered mode");
6263 			err = -EINVAL;
6264 			goto restore_opts;
6265 		}
6266 	}
6267 
6268 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6269 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6270 		err = -EINVAL;
6271 		goto restore_opts;
6272 	}
6273 
6274 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6275 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6276 
6277 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6278 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6279 
6280 	es = sbi->s_es;
6281 
6282 	if (sbi->s_journal) {
6283 		ext4_init_journal_params(sb, sbi->s_journal);
6284 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6285 	}
6286 
6287 	/* Flush outstanding errors before changing fs state */
6288 	flush_work(&sbi->s_error_work);
6289 
6290 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6291 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6292 			err = -EROFS;
6293 			goto restore_opts;
6294 		}
6295 
6296 		if (fc->sb_flags & SB_RDONLY) {
6297 			err = sync_filesystem(sb);
6298 			if (err < 0)
6299 				goto restore_opts;
6300 			err = dquot_suspend(sb, -1);
6301 			if (err < 0)
6302 				goto restore_opts;
6303 
6304 			/*
6305 			 * First of all, the unconditional stuff we have to do
6306 			 * to disable replay of the journal when we next remount
6307 			 */
6308 			sb->s_flags |= SB_RDONLY;
6309 
6310 			/*
6311 			 * OK, test if we are remounting a valid rw partition
6312 			 * readonly, and if so set the rdonly flag and then
6313 			 * mark the partition as valid again.
6314 			 */
6315 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6316 			    (sbi->s_mount_state & EXT4_VALID_FS))
6317 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6318 
6319 			if (sbi->s_journal) {
6320 				/*
6321 				 * We let remount-ro finish even if marking fs
6322 				 * as clean failed...
6323 				 */
6324 				ext4_mark_recovery_complete(sb, es);
6325 			}
6326 		} else {
6327 			/* Make sure we can mount this feature set readwrite */
6328 			if (ext4_has_feature_readonly(sb) ||
6329 			    !ext4_feature_set_ok(sb, 0)) {
6330 				err = -EROFS;
6331 				goto restore_opts;
6332 			}
6333 			/*
6334 			 * Make sure the group descriptor checksums
6335 			 * are sane.  If they aren't, refuse to remount r/w.
6336 			 */
6337 			for (g = 0; g < sbi->s_groups_count; g++) {
6338 				struct ext4_group_desc *gdp =
6339 					ext4_get_group_desc(sb, g, NULL);
6340 
6341 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6342 					ext4_msg(sb, KERN_ERR,
6343 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6344 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6345 					       le16_to_cpu(gdp->bg_checksum));
6346 					err = -EFSBADCRC;
6347 					goto restore_opts;
6348 				}
6349 			}
6350 
6351 			/*
6352 			 * If we have an unprocessed orphan list hanging
6353 			 * around from a previously readonly bdev mount,
6354 			 * require a full umount/remount for now.
6355 			 */
6356 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6357 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6358 				       "remount RDWR because of unprocessed "
6359 				       "orphan inode list.  Please "
6360 				       "umount/remount instead");
6361 				err = -EINVAL;
6362 				goto restore_opts;
6363 			}
6364 
6365 			/*
6366 			 * Mounting a RDONLY partition read-write, so reread
6367 			 * and store the current valid flag.  (It may have
6368 			 * been changed by e2fsck since we originally mounted
6369 			 * the partition.)
6370 			 */
6371 			if (sbi->s_journal) {
6372 				err = ext4_clear_journal_err(sb, es);
6373 				if (err)
6374 					goto restore_opts;
6375 			}
6376 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6377 					      ~EXT4_FC_REPLAY);
6378 
6379 			err = ext4_setup_super(sb, es, 0);
6380 			if (err)
6381 				goto restore_opts;
6382 
6383 			sb->s_flags &= ~SB_RDONLY;
6384 			if (ext4_has_feature_mmp(sb))
6385 				if (ext4_multi_mount_protect(sb,
6386 						le64_to_cpu(es->s_mmp_block))) {
6387 					err = -EROFS;
6388 					goto restore_opts;
6389 				}
6390 #ifdef CONFIG_QUOTA
6391 			enable_quota = 1;
6392 #endif
6393 		}
6394 	}
6395 
6396 	/*
6397 	 * Reinitialize lazy itable initialization thread based on
6398 	 * current settings
6399 	 */
6400 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6401 		ext4_unregister_li_request(sb);
6402 	else {
6403 		ext4_group_t first_not_zeroed;
6404 		first_not_zeroed = ext4_has_uninit_itable(sb);
6405 		ext4_register_li_request(sb, first_not_zeroed);
6406 	}
6407 
6408 	/*
6409 	 * Handle creation of system zone data early because it can fail.
6410 	 * Releasing of existing data is done when we are sure remount will
6411 	 * succeed.
6412 	 */
6413 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6414 		err = ext4_setup_system_zone(sb);
6415 		if (err)
6416 			goto restore_opts;
6417 	}
6418 
6419 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6420 		err = ext4_commit_super(sb);
6421 		if (err)
6422 			goto restore_opts;
6423 	}
6424 
6425 #ifdef CONFIG_QUOTA
6426 	/* Release old quota file names */
6427 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6428 		kfree(old_opts.s_qf_names[i]);
6429 	if (enable_quota) {
6430 		if (sb_any_quota_suspended(sb))
6431 			dquot_resume(sb, -1);
6432 		else if (ext4_has_feature_quota(sb)) {
6433 			err = ext4_enable_quotas(sb);
6434 			if (err)
6435 				goto restore_opts;
6436 		}
6437 	}
6438 #endif
6439 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6440 		ext4_release_system_zone(sb);
6441 
6442 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6443 		ext4_stop_mmpd(sbi);
6444 
6445 	return 0;
6446 
6447 restore_opts:
6448 	sb->s_flags = old_sb_flags;
6449 	sbi->s_mount_opt = old_opts.s_mount_opt;
6450 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6451 	sbi->s_resuid = old_opts.s_resuid;
6452 	sbi->s_resgid = old_opts.s_resgid;
6453 	sbi->s_commit_interval = old_opts.s_commit_interval;
6454 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6455 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6456 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6457 		ext4_release_system_zone(sb);
6458 #ifdef CONFIG_QUOTA
6459 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6460 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6461 		to_free[i] = get_qf_name(sb, sbi, i);
6462 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6463 	}
6464 	synchronize_rcu();
6465 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6466 		kfree(to_free[i]);
6467 #endif
6468 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6469 		ext4_stop_mmpd(sbi);
6470 	return err;
6471 }
6472 
6473 static int ext4_reconfigure(struct fs_context *fc)
6474 {
6475 	struct super_block *sb = fc->root->d_sb;
6476 	int ret;
6477 
6478 	fc->s_fs_info = EXT4_SB(sb);
6479 
6480 	ret = ext4_check_opt_consistency(fc, sb);
6481 	if (ret < 0)
6482 		return ret;
6483 
6484 	ret = __ext4_remount(fc, sb);
6485 	if (ret < 0)
6486 		return ret;
6487 
6488 	ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6489 		 ext4_quota_mode(sb));
6490 
6491 	return 0;
6492 }
6493 
6494 #ifdef CONFIG_QUOTA
6495 static int ext4_statfs_project(struct super_block *sb,
6496 			       kprojid_t projid, struct kstatfs *buf)
6497 {
6498 	struct kqid qid;
6499 	struct dquot *dquot;
6500 	u64 limit;
6501 	u64 curblock;
6502 
6503 	qid = make_kqid_projid(projid);
6504 	dquot = dqget(sb, qid);
6505 	if (IS_ERR(dquot))
6506 		return PTR_ERR(dquot);
6507 	spin_lock(&dquot->dq_dqb_lock);
6508 
6509 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6510 			     dquot->dq_dqb.dqb_bhardlimit);
6511 	limit >>= sb->s_blocksize_bits;
6512 
6513 	if (limit && buf->f_blocks > limit) {
6514 		curblock = (dquot->dq_dqb.dqb_curspace +
6515 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6516 		buf->f_blocks = limit;
6517 		buf->f_bfree = buf->f_bavail =
6518 			(buf->f_blocks > curblock) ?
6519 			 (buf->f_blocks - curblock) : 0;
6520 	}
6521 
6522 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6523 			     dquot->dq_dqb.dqb_ihardlimit);
6524 	if (limit && buf->f_files > limit) {
6525 		buf->f_files = limit;
6526 		buf->f_ffree =
6527 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6528 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6529 	}
6530 
6531 	spin_unlock(&dquot->dq_dqb_lock);
6532 	dqput(dquot);
6533 	return 0;
6534 }
6535 #endif
6536 
6537 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6538 {
6539 	struct super_block *sb = dentry->d_sb;
6540 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6541 	struct ext4_super_block *es = sbi->s_es;
6542 	ext4_fsblk_t overhead = 0, resv_blocks;
6543 	s64 bfree;
6544 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6545 
6546 	if (!test_opt(sb, MINIX_DF))
6547 		overhead = sbi->s_overhead;
6548 
6549 	buf->f_type = EXT4_SUPER_MAGIC;
6550 	buf->f_bsize = sb->s_blocksize;
6551 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6552 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6553 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6554 	/* prevent underflow in case that few free space is available */
6555 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6556 	buf->f_bavail = buf->f_bfree -
6557 			(ext4_r_blocks_count(es) + resv_blocks);
6558 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6559 		buf->f_bavail = 0;
6560 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6561 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6562 	buf->f_namelen = EXT4_NAME_LEN;
6563 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6564 
6565 #ifdef CONFIG_QUOTA
6566 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6567 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6568 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6569 #endif
6570 	return 0;
6571 }
6572 
6573 
6574 #ifdef CONFIG_QUOTA
6575 
6576 /*
6577  * Helper functions so that transaction is started before we acquire dqio_sem
6578  * to keep correct lock ordering of transaction > dqio_sem
6579  */
6580 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6581 {
6582 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6583 }
6584 
6585 static int ext4_write_dquot(struct dquot *dquot)
6586 {
6587 	int ret, err;
6588 	handle_t *handle;
6589 	struct inode *inode;
6590 
6591 	inode = dquot_to_inode(dquot);
6592 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6593 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6594 	if (IS_ERR(handle))
6595 		return PTR_ERR(handle);
6596 	ret = dquot_commit(dquot);
6597 	err = ext4_journal_stop(handle);
6598 	if (!ret)
6599 		ret = err;
6600 	return ret;
6601 }
6602 
6603 static int ext4_acquire_dquot(struct dquot *dquot)
6604 {
6605 	int ret, err;
6606 	handle_t *handle;
6607 
6608 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6609 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6610 	if (IS_ERR(handle))
6611 		return PTR_ERR(handle);
6612 	ret = dquot_acquire(dquot);
6613 	err = ext4_journal_stop(handle);
6614 	if (!ret)
6615 		ret = err;
6616 	return ret;
6617 }
6618 
6619 static int ext4_release_dquot(struct dquot *dquot)
6620 {
6621 	int ret, err;
6622 	handle_t *handle;
6623 
6624 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6625 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6626 	if (IS_ERR(handle)) {
6627 		/* Release dquot anyway to avoid endless cycle in dqput() */
6628 		dquot_release(dquot);
6629 		return PTR_ERR(handle);
6630 	}
6631 	ret = dquot_release(dquot);
6632 	err = ext4_journal_stop(handle);
6633 	if (!ret)
6634 		ret = err;
6635 	return ret;
6636 }
6637 
6638 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6639 {
6640 	struct super_block *sb = dquot->dq_sb;
6641 
6642 	if (ext4_is_quota_journalled(sb)) {
6643 		dquot_mark_dquot_dirty(dquot);
6644 		return ext4_write_dquot(dquot);
6645 	} else {
6646 		return dquot_mark_dquot_dirty(dquot);
6647 	}
6648 }
6649 
6650 static int ext4_write_info(struct super_block *sb, int type)
6651 {
6652 	int ret, err;
6653 	handle_t *handle;
6654 
6655 	/* Data block + inode block */
6656 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6657 	if (IS_ERR(handle))
6658 		return PTR_ERR(handle);
6659 	ret = dquot_commit_info(sb, type);
6660 	err = ext4_journal_stop(handle);
6661 	if (!ret)
6662 		ret = err;
6663 	return ret;
6664 }
6665 
6666 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6667 {
6668 	struct ext4_inode_info *ei = EXT4_I(inode);
6669 
6670 	/* The first argument of lockdep_set_subclass has to be
6671 	 * *exactly* the same as the argument to init_rwsem() --- in
6672 	 * this case, in init_once() --- or lockdep gets unhappy
6673 	 * because the name of the lock is set using the
6674 	 * stringification of the argument to init_rwsem().
6675 	 */
6676 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6677 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6678 }
6679 
6680 /*
6681  * Standard function to be called on quota_on
6682  */
6683 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6684 			 const struct path *path)
6685 {
6686 	int err;
6687 
6688 	if (!test_opt(sb, QUOTA))
6689 		return -EINVAL;
6690 
6691 	/* Quotafile not on the same filesystem? */
6692 	if (path->dentry->d_sb != sb)
6693 		return -EXDEV;
6694 
6695 	/* Quota already enabled for this file? */
6696 	if (IS_NOQUOTA(d_inode(path->dentry)))
6697 		return -EBUSY;
6698 
6699 	/* Journaling quota? */
6700 	if (EXT4_SB(sb)->s_qf_names[type]) {
6701 		/* Quotafile not in fs root? */
6702 		if (path->dentry->d_parent != sb->s_root)
6703 			ext4_msg(sb, KERN_WARNING,
6704 				"Quota file not on filesystem root. "
6705 				"Journaled quota will not work");
6706 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6707 	} else {
6708 		/*
6709 		 * Clear the flag just in case mount options changed since
6710 		 * last time.
6711 		 */
6712 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6713 	}
6714 
6715 	/*
6716 	 * When we journal data on quota file, we have to flush journal to see
6717 	 * all updates to the file when we bypass pagecache...
6718 	 */
6719 	if (EXT4_SB(sb)->s_journal &&
6720 	    ext4_should_journal_data(d_inode(path->dentry))) {
6721 		/*
6722 		 * We don't need to lock updates but journal_flush() could
6723 		 * otherwise be livelocked...
6724 		 */
6725 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6726 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6727 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6728 		if (err)
6729 			return err;
6730 	}
6731 
6732 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6733 	err = dquot_quota_on(sb, type, format_id, path);
6734 	if (!err) {
6735 		struct inode *inode = d_inode(path->dentry);
6736 		handle_t *handle;
6737 
6738 		/*
6739 		 * Set inode flags to prevent userspace from messing with quota
6740 		 * files. If this fails, we return success anyway since quotas
6741 		 * are already enabled and this is not a hard failure.
6742 		 */
6743 		inode_lock(inode);
6744 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6745 		if (IS_ERR(handle))
6746 			goto unlock_inode;
6747 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6748 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6749 				S_NOATIME | S_IMMUTABLE);
6750 		err = ext4_mark_inode_dirty(handle, inode);
6751 		ext4_journal_stop(handle);
6752 	unlock_inode:
6753 		inode_unlock(inode);
6754 		if (err)
6755 			dquot_quota_off(sb, type);
6756 	}
6757 	if (err)
6758 		lockdep_set_quota_inode(path->dentry->d_inode,
6759 					     I_DATA_SEM_NORMAL);
6760 	return err;
6761 }
6762 
6763 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6764 			     unsigned int flags)
6765 {
6766 	int err;
6767 	struct inode *qf_inode;
6768 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6769 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6770 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6771 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6772 	};
6773 
6774 	BUG_ON(!ext4_has_feature_quota(sb));
6775 
6776 	if (!qf_inums[type])
6777 		return -EPERM;
6778 
6779 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6780 	if (IS_ERR(qf_inode)) {
6781 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6782 		return PTR_ERR(qf_inode);
6783 	}
6784 
6785 	/* Don't account quota for quota files to avoid recursion */
6786 	qf_inode->i_flags |= S_NOQUOTA;
6787 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6788 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6789 	if (err)
6790 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6791 	iput(qf_inode);
6792 
6793 	return err;
6794 }
6795 
6796 /* Enable usage tracking for all quota types. */
6797 int ext4_enable_quotas(struct super_block *sb)
6798 {
6799 	int type, err = 0;
6800 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6801 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6802 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6803 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6804 	};
6805 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6806 		test_opt(sb, USRQUOTA),
6807 		test_opt(sb, GRPQUOTA),
6808 		test_opt(sb, PRJQUOTA),
6809 	};
6810 
6811 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6812 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6813 		if (qf_inums[type]) {
6814 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6815 				DQUOT_USAGE_ENABLED |
6816 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6817 			if (err) {
6818 				ext4_warning(sb,
6819 					"Failed to enable quota tracking "
6820 					"(type=%d, err=%d). Please run "
6821 					"e2fsck to fix.", type, err);
6822 				for (type--; type >= 0; type--) {
6823 					struct inode *inode;
6824 
6825 					inode = sb_dqopt(sb)->files[type];
6826 					if (inode)
6827 						inode = igrab(inode);
6828 					dquot_quota_off(sb, type);
6829 					if (inode) {
6830 						lockdep_set_quota_inode(inode,
6831 							I_DATA_SEM_NORMAL);
6832 						iput(inode);
6833 					}
6834 				}
6835 
6836 				return err;
6837 			}
6838 		}
6839 	}
6840 	return 0;
6841 }
6842 
6843 static int ext4_quota_off(struct super_block *sb, int type)
6844 {
6845 	struct inode *inode = sb_dqopt(sb)->files[type];
6846 	handle_t *handle;
6847 	int err;
6848 
6849 	/* Force all delayed allocation blocks to be allocated.
6850 	 * Caller already holds s_umount sem */
6851 	if (test_opt(sb, DELALLOC))
6852 		sync_filesystem(sb);
6853 
6854 	if (!inode || !igrab(inode))
6855 		goto out;
6856 
6857 	err = dquot_quota_off(sb, type);
6858 	if (err || ext4_has_feature_quota(sb))
6859 		goto out_put;
6860 
6861 	inode_lock(inode);
6862 	/*
6863 	 * Update modification times of quota files when userspace can
6864 	 * start looking at them. If we fail, we return success anyway since
6865 	 * this is not a hard failure and quotas are already disabled.
6866 	 */
6867 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6868 	if (IS_ERR(handle)) {
6869 		err = PTR_ERR(handle);
6870 		goto out_unlock;
6871 	}
6872 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6873 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6874 	inode->i_mtime = inode->i_ctime = current_time(inode);
6875 	err = ext4_mark_inode_dirty(handle, inode);
6876 	ext4_journal_stop(handle);
6877 out_unlock:
6878 	inode_unlock(inode);
6879 out_put:
6880 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6881 	iput(inode);
6882 	return err;
6883 out:
6884 	return dquot_quota_off(sb, type);
6885 }
6886 
6887 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6888  * acquiring the locks... As quota files are never truncated and quota code
6889  * itself serializes the operations (and no one else should touch the files)
6890  * we don't have to be afraid of races */
6891 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6892 			       size_t len, loff_t off)
6893 {
6894 	struct inode *inode = sb_dqopt(sb)->files[type];
6895 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6896 	int offset = off & (sb->s_blocksize - 1);
6897 	int tocopy;
6898 	size_t toread;
6899 	struct buffer_head *bh;
6900 	loff_t i_size = i_size_read(inode);
6901 
6902 	if (off > i_size)
6903 		return 0;
6904 	if (off+len > i_size)
6905 		len = i_size-off;
6906 	toread = len;
6907 	while (toread > 0) {
6908 		tocopy = sb->s_blocksize - offset < toread ?
6909 				sb->s_blocksize - offset : toread;
6910 		bh = ext4_bread(NULL, inode, blk, 0);
6911 		if (IS_ERR(bh))
6912 			return PTR_ERR(bh);
6913 		if (!bh)	/* A hole? */
6914 			memset(data, 0, tocopy);
6915 		else
6916 			memcpy(data, bh->b_data+offset, tocopy);
6917 		brelse(bh);
6918 		offset = 0;
6919 		toread -= tocopy;
6920 		data += tocopy;
6921 		blk++;
6922 	}
6923 	return len;
6924 }
6925 
6926 /* Write to quotafile (we know the transaction is already started and has
6927  * enough credits) */
6928 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6929 				const char *data, size_t len, loff_t off)
6930 {
6931 	struct inode *inode = sb_dqopt(sb)->files[type];
6932 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6933 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6934 	int retries = 0;
6935 	struct buffer_head *bh;
6936 	handle_t *handle = journal_current_handle();
6937 
6938 	if (!handle) {
6939 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6940 			" cancelled because transaction is not started",
6941 			(unsigned long long)off, (unsigned long long)len);
6942 		return -EIO;
6943 	}
6944 	/*
6945 	 * Since we account only one data block in transaction credits,
6946 	 * then it is impossible to cross a block boundary.
6947 	 */
6948 	if (sb->s_blocksize - offset < len) {
6949 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6950 			" cancelled because not block aligned",
6951 			(unsigned long long)off, (unsigned long long)len);
6952 		return -EIO;
6953 	}
6954 
6955 	do {
6956 		bh = ext4_bread(handle, inode, blk,
6957 				EXT4_GET_BLOCKS_CREATE |
6958 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6959 	} while (PTR_ERR(bh) == -ENOSPC &&
6960 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6961 	if (IS_ERR(bh))
6962 		return PTR_ERR(bh);
6963 	if (!bh)
6964 		goto out;
6965 	BUFFER_TRACE(bh, "get write access");
6966 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
6967 	if (err) {
6968 		brelse(bh);
6969 		return err;
6970 	}
6971 	lock_buffer(bh);
6972 	memcpy(bh->b_data+offset, data, len);
6973 	flush_dcache_page(bh->b_page);
6974 	unlock_buffer(bh);
6975 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6976 	brelse(bh);
6977 out:
6978 	if (inode->i_size < off + len) {
6979 		i_size_write(inode, off + len);
6980 		EXT4_I(inode)->i_disksize = inode->i_size;
6981 		err2 = ext4_mark_inode_dirty(handle, inode);
6982 		if (unlikely(err2 && !err))
6983 			err = err2;
6984 	}
6985 	return err ? err : len;
6986 }
6987 #endif
6988 
6989 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6990 static inline void register_as_ext2(void)
6991 {
6992 	int err = register_filesystem(&ext2_fs_type);
6993 	if (err)
6994 		printk(KERN_WARNING
6995 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6996 }
6997 
6998 static inline void unregister_as_ext2(void)
6999 {
7000 	unregister_filesystem(&ext2_fs_type);
7001 }
7002 
7003 static inline int ext2_feature_set_ok(struct super_block *sb)
7004 {
7005 	if (ext4_has_unknown_ext2_incompat_features(sb))
7006 		return 0;
7007 	if (sb_rdonly(sb))
7008 		return 1;
7009 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7010 		return 0;
7011 	return 1;
7012 }
7013 #else
7014 static inline void register_as_ext2(void) { }
7015 static inline void unregister_as_ext2(void) { }
7016 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7017 #endif
7018 
7019 static inline void register_as_ext3(void)
7020 {
7021 	int err = register_filesystem(&ext3_fs_type);
7022 	if (err)
7023 		printk(KERN_WARNING
7024 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7025 }
7026 
7027 static inline void unregister_as_ext3(void)
7028 {
7029 	unregister_filesystem(&ext3_fs_type);
7030 }
7031 
7032 static inline int ext3_feature_set_ok(struct super_block *sb)
7033 {
7034 	if (ext4_has_unknown_ext3_incompat_features(sb))
7035 		return 0;
7036 	if (!ext4_has_feature_journal(sb))
7037 		return 0;
7038 	if (sb_rdonly(sb))
7039 		return 1;
7040 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7041 		return 0;
7042 	return 1;
7043 }
7044 
7045 static struct file_system_type ext4_fs_type = {
7046 	.owner			= THIS_MODULE,
7047 	.name			= "ext4",
7048 	.init_fs_context	= ext4_init_fs_context,
7049 	.parameters		= ext4_param_specs,
7050 	.kill_sb		= kill_block_super,
7051 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7052 };
7053 MODULE_ALIAS_FS("ext4");
7054 
7055 /* Shared across all ext4 file systems */
7056 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7057 
7058 static int __init ext4_init_fs(void)
7059 {
7060 	int i, err;
7061 
7062 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7063 	ext4_li_info = NULL;
7064 
7065 	/* Build-time check for flags consistency */
7066 	ext4_check_flag_values();
7067 
7068 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7069 		init_waitqueue_head(&ext4__ioend_wq[i]);
7070 
7071 	err = ext4_init_es();
7072 	if (err)
7073 		return err;
7074 
7075 	err = ext4_init_pending();
7076 	if (err)
7077 		goto out7;
7078 
7079 	err = ext4_init_post_read_processing();
7080 	if (err)
7081 		goto out6;
7082 
7083 	err = ext4_init_pageio();
7084 	if (err)
7085 		goto out5;
7086 
7087 	err = ext4_init_system_zone();
7088 	if (err)
7089 		goto out4;
7090 
7091 	err = ext4_init_sysfs();
7092 	if (err)
7093 		goto out3;
7094 
7095 	err = ext4_init_mballoc();
7096 	if (err)
7097 		goto out2;
7098 	err = init_inodecache();
7099 	if (err)
7100 		goto out1;
7101 
7102 	err = ext4_fc_init_dentry_cache();
7103 	if (err)
7104 		goto out05;
7105 
7106 	register_as_ext3();
7107 	register_as_ext2();
7108 	err = register_filesystem(&ext4_fs_type);
7109 	if (err)
7110 		goto out;
7111 
7112 	return 0;
7113 out:
7114 	unregister_as_ext2();
7115 	unregister_as_ext3();
7116 	ext4_fc_destroy_dentry_cache();
7117 out05:
7118 	destroy_inodecache();
7119 out1:
7120 	ext4_exit_mballoc();
7121 out2:
7122 	ext4_exit_sysfs();
7123 out3:
7124 	ext4_exit_system_zone();
7125 out4:
7126 	ext4_exit_pageio();
7127 out5:
7128 	ext4_exit_post_read_processing();
7129 out6:
7130 	ext4_exit_pending();
7131 out7:
7132 	ext4_exit_es();
7133 
7134 	return err;
7135 }
7136 
7137 static void __exit ext4_exit_fs(void)
7138 {
7139 	ext4_destroy_lazyinit_thread();
7140 	unregister_as_ext2();
7141 	unregister_as_ext3();
7142 	unregister_filesystem(&ext4_fs_type);
7143 	ext4_fc_destroy_dentry_cache();
7144 	destroy_inodecache();
7145 	ext4_exit_mballoc();
7146 	ext4_exit_sysfs();
7147 	ext4_exit_system_zone();
7148 	ext4_exit_pageio();
7149 	ext4_exit_post_read_processing();
7150 	ext4_exit_es();
7151 	ext4_exit_pending();
7152 }
7153 
7154 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7155 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7156 MODULE_LICENSE("GPL");
7157 MODULE_SOFTDEP("pre: crc32c");
7158 module_init(ext4_init_fs)
7159 module_exit(ext4_exit_fs)
7160