xref: /openbmc/linux/fs/ext4/super.c (revision 8a1e6bb3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static int ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= kill_block_super,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= kill_block_super,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ, op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
207 {
208 	if (trylock_buffer(bh)) {
209 		if (wait)
210 			return ext4_read_bh(bh, op_flags, NULL);
211 		ext4_read_bh_nowait(bh, op_flags, NULL);
212 		return 0;
213 	}
214 	if (wait) {
215 		wait_on_buffer(bh);
216 		if (buffer_uptodate(bh))
217 			return 0;
218 		return -EIO;
219 	}
220 	return 0;
221 }
222 
223 /*
224  * This works like __bread_gfp() except it uses ERR_PTR for error
225  * returns.  Currently with sb_bread it's impossible to distinguish
226  * between ENOMEM and EIO situations (since both result in a NULL
227  * return.
228  */
229 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
230 					       sector_t block, int op_flags,
231 					       gfp_t gfp)
232 {
233 	struct buffer_head *bh;
234 	int ret;
235 
236 	bh = sb_getblk_gfp(sb, block, gfp);
237 	if (bh == NULL)
238 		return ERR_PTR(-ENOMEM);
239 	if (ext4_buffer_uptodate(bh))
240 		return bh;
241 
242 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
243 	if (ret) {
244 		put_bh(bh);
245 		return ERR_PTR(ret);
246 	}
247 	return bh;
248 }
249 
250 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
251 				   int op_flags)
252 {
253 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
254 }
255 
256 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
257 					    sector_t block)
258 {
259 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
260 }
261 
262 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
263 {
264 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
265 
266 	if (likely(bh)) {
267 		ext4_read_bh_lock(bh, REQ_RAHEAD, false);
268 		brelse(bh);
269 	}
270 }
271 
272 static int ext4_verify_csum_type(struct super_block *sb,
273 				 struct ext4_super_block *es)
274 {
275 	if (!ext4_has_feature_metadata_csum(sb))
276 		return 1;
277 
278 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
279 }
280 
281 __le32 ext4_superblock_csum(struct super_block *sb,
282 			    struct ext4_super_block *es)
283 {
284 	struct ext4_sb_info *sbi = EXT4_SB(sb);
285 	int offset = offsetof(struct ext4_super_block, s_checksum);
286 	__u32 csum;
287 
288 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
289 
290 	return cpu_to_le32(csum);
291 }
292 
293 static int ext4_superblock_csum_verify(struct super_block *sb,
294 				       struct ext4_super_block *es)
295 {
296 	if (!ext4_has_metadata_csum(sb))
297 		return 1;
298 
299 	return es->s_checksum == ext4_superblock_csum(sb, es);
300 }
301 
302 void ext4_superblock_csum_set(struct super_block *sb)
303 {
304 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
305 
306 	if (!ext4_has_metadata_csum(sb))
307 		return;
308 
309 	es->s_checksum = ext4_superblock_csum(sb, es);
310 }
311 
312 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
313 			       struct ext4_group_desc *bg)
314 {
315 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
316 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
317 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
318 }
319 
320 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
321 			       struct ext4_group_desc *bg)
322 {
323 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
324 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
325 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
326 }
327 
328 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
329 			      struct ext4_group_desc *bg)
330 {
331 	return le32_to_cpu(bg->bg_inode_table_lo) |
332 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
333 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
334 }
335 
336 __u32 ext4_free_group_clusters(struct super_block *sb,
337 			       struct ext4_group_desc *bg)
338 {
339 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
340 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
341 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
342 }
343 
344 __u32 ext4_free_inodes_count(struct super_block *sb,
345 			      struct ext4_group_desc *bg)
346 {
347 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
348 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
349 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
350 }
351 
352 __u32 ext4_used_dirs_count(struct super_block *sb,
353 			      struct ext4_group_desc *bg)
354 {
355 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
356 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
357 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
358 }
359 
360 __u32 ext4_itable_unused_count(struct super_block *sb,
361 			      struct ext4_group_desc *bg)
362 {
363 	return le16_to_cpu(bg->bg_itable_unused_lo) |
364 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
365 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
366 }
367 
368 void ext4_block_bitmap_set(struct super_block *sb,
369 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
370 {
371 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
372 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
373 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
374 }
375 
376 void ext4_inode_bitmap_set(struct super_block *sb,
377 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
378 {
379 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
380 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
381 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
382 }
383 
384 void ext4_inode_table_set(struct super_block *sb,
385 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
386 {
387 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
388 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
389 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
390 }
391 
392 void ext4_free_group_clusters_set(struct super_block *sb,
393 				  struct ext4_group_desc *bg, __u32 count)
394 {
395 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
396 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
397 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
398 }
399 
400 void ext4_free_inodes_set(struct super_block *sb,
401 			  struct ext4_group_desc *bg, __u32 count)
402 {
403 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
404 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
405 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
406 }
407 
408 void ext4_used_dirs_set(struct super_block *sb,
409 			  struct ext4_group_desc *bg, __u32 count)
410 {
411 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
412 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
413 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
414 }
415 
416 void ext4_itable_unused_set(struct super_block *sb,
417 			  struct ext4_group_desc *bg, __u32 count)
418 {
419 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
420 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
421 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
422 }
423 
424 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
425 {
426 	now = clamp_val(now, 0, (1ull << 40) - 1);
427 
428 	*lo = cpu_to_le32(lower_32_bits(now));
429 	*hi = upper_32_bits(now);
430 }
431 
432 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
433 {
434 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
435 }
436 #define ext4_update_tstamp(es, tstamp) \
437 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
438 			     ktime_get_real_seconds())
439 #define ext4_get_tstamp(es, tstamp) \
440 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
441 
442 /*
443  * The del_gendisk() function uninitializes the disk-specific data
444  * structures, including the bdi structure, without telling anyone
445  * else.  Once this happens, any attempt to call mark_buffer_dirty()
446  * (for example, by ext4_commit_super), will cause a kernel OOPS.
447  * This is a kludge to prevent these oops until we can put in a proper
448  * hook in del_gendisk() to inform the VFS and file system layers.
449  */
450 static int block_device_ejected(struct super_block *sb)
451 {
452 	struct inode *bd_inode = sb->s_bdev->bd_inode;
453 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
454 
455 	return bdi->dev == NULL;
456 }
457 
458 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
459 {
460 	struct super_block		*sb = journal->j_private;
461 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
462 	int				error = is_journal_aborted(journal);
463 	struct ext4_journal_cb_entry	*jce;
464 
465 	BUG_ON(txn->t_state == T_FINISHED);
466 
467 	ext4_process_freed_data(sb, txn->t_tid);
468 
469 	spin_lock(&sbi->s_md_lock);
470 	while (!list_empty(&txn->t_private_list)) {
471 		jce = list_entry(txn->t_private_list.next,
472 				 struct ext4_journal_cb_entry, jce_list);
473 		list_del_init(&jce->jce_list);
474 		spin_unlock(&sbi->s_md_lock);
475 		jce->jce_func(sb, jce, error);
476 		spin_lock(&sbi->s_md_lock);
477 	}
478 	spin_unlock(&sbi->s_md_lock);
479 }
480 
481 /*
482  * This writepage callback for write_cache_pages()
483  * takes care of a few cases after page cleaning.
484  *
485  * write_cache_pages() already checks for dirty pages
486  * and calls clear_page_dirty_for_io(), which we want,
487  * to write protect the pages.
488  *
489  * However, we may have to redirty a page (see below.)
490  */
491 static int ext4_journalled_writepage_callback(struct page *page,
492 					      struct writeback_control *wbc,
493 					      void *data)
494 {
495 	transaction_t *transaction = (transaction_t *) data;
496 	struct buffer_head *bh, *head;
497 	struct journal_head *jh;
498 
499 	bh = head = page_buffers(page);
500 	do {
501 		/*
502 		 * We have to redirty a page in these cases:
503 		 * 1) If buffer is dirty, it means the page was dirty because it
504 		 * contains a buffer that needs checkpointing. So the dirty bit
505 		 * needs to be preserved so that checkpointing writes the buffer
506 		 * properly.
507 		 * 2) If buffer is not part of the committing transaction
508 		 * (we may have just accidentally come across this buffer because
509 		 * inode range tracking is not exact) or if the currently running
510 		 * transaction already contains this buffer as well, dirty bit
511 		 * needs to be preserved so that the buffer gets writeprotected
512 		 * properly on running transaction's commit.
513 		 */
514 		jh = bh2jh(bh);
515 		if (buffer_dirty(bh) ||
516 		    (jh && (jh->b_transaction != transaction ||
517 			    jh->b_next_transaction))) {
518 			redirty_page_for_writepage(wbc, page);
519 			goto out;
520 		}
521 	} while ((bh = bh->b_this_page) != head);
522 
523 out:
524 	return AOP_WRITEPAGE_ACTIVATE;
525 }
526 
527 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
528 {
529 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
530 	struct writeback_control wbc = {
531 		.sync_mode =  WB_SYNC_ALL,
532 		.nr_to_write = LONG_MAX,
533 		.range_start = jinode->i_dirty_start,
534 		.range_end = jinode->i_dirty_end,
535         };
536 
537 	return write_cache_pages(mapping, &wbc,
538 				 ext4_journalled_writepage_callback,
539 				 jinode->i_transaction);
540 }
541 
542 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
543 {
544 	int ret;
545 
546 	if (ext4_should_journal_data(jinode->i_vfs_inode))
547 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
548 	else
549 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
550 
551 	return ret;
552 }
553 
554 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
555 {
556 	int ret = 0;
557 
558 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
559 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
560 
561 	return ret;
562 }
563 
564 static bool system_going_down(void)
565 {
566 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
567 		|| system_state == SYSTEM_RESTART;
568 }
569 
570 struct ext4_err_translation {
571 	int code;
572 	int errno;
573 };
574 
575 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
576 
577 static struct ext4_err_translation err_translation[] = {
578 	EXT4_ERR_TRANSLATE(EIO),
579 	EXT4_ERR_TRANSLATE(ENOMEM),
580 	EXT4_ERR_TRANSLATE(EFSBADCRC),
581 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
582 	EXT4_ERR_TRANSLATE(ENOSPC),
583 	EXT4_ERR_TRANSLATE(ENOKEY),
584 	EXT4_ERR_TRANSLATE(EROFS),
585 	EXT4_ERR_TRANSLATE(EFBIG),
586 	EXT4_ERR_TRANSLATE(EEXIST),
587 	EXT4_ERR_TRANSLATE(ERANGE),
588 	EXT4_ERR_TRANSLATE(EOVERFLOW),
589 	EXT4_ERR_TRANSLATE(EBUSY),
590 	EXT4_ERR_TRANSLATE(ENOTDIR),
591 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
592 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
593 	EXT4_ERR_TRANSLATE(EFAULT),
594 };
595 
596 static int ext4_errno_to_code(int errno)
597 {
598 	int i;
599 
600 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
601 		if (err_translation[i].errno == errno)
602 			return err_translation[i].code;
603 	return EXT4_ERR_UNKNOWN;
604 }
605 
606 static void save_error_info(struct super_block *sb, int error,
607 			    __u32 ino, __u64 block,
608 			    const char *func, unsigned int line)
609 {
610 	struct ext4_sb_info *sbi = EXT4_SB(sb);
611 
612 	/* We default to EFSCORRUPTED error... */
613 	if (error == 0)
614 		error = EFSCORRUPTED;
615 
616 	spin_lock(&sbi->s_error_lock);
617 	sbi->s_add_error_count++;
618 	sbi->s_last_error_code = error;
619 	sbi->s_last_error_line = line;
620 	sbi->s_last_error_ino = ino;
621 	sbi->s_last_error_block = block;
622 	sbi->s_last_error_func = func;
623 	sbi->s_last_error_time = ktime_get_real_seconds();
624 	if (!sbi->s_first_error_time) {
625 		sbi->s_first_error_code = error;
626 		sbi->s_first_error_line = line;
627 		sbi->s_first_error_ino = ino;
628 		sbi->s_first_error_block = block;
629 		sbi->s_first_error_func = func;
630 		sbi->s_first_error_time = sbi->s_last_error_time;
631 	}
632 	spin_unlock(&sbi->s_error_lock);
633 }
634 
635 /* Deal with the reporting of failure conditions on a filesystem such as
636  * inconsistencies detected or read IO failures.
637  *
638  * On ext2, we can store the error state of the filesystem in the
639  * superblock.  That is not possible on ext4, because we may have other
640  * write ordering constraints on the superblock which prevent us from
641  * writing it out straight away; and given that the journal is about to
642  * be aborted, we can't rely on the current, or future, transactions to
643  * write out the superblock safely.
644  *
645  * We'll just use the jbd2_journal_abort() error code to record an error in
646  * the journal instead.  On recovery, the journal will complain about
647  * that error until we've noted it down and cleared it.
648  *
649  * If force_ro is set, we unconditionally force the filesystem into an
650  * ABORT|READONLY state, unless the error response on the fs has been set to
651  * panic in which case we take the easy way out and panic immediately. This is
652  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
653  * at a critical moment in log management.
654  */
655 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
656 			      __u32 ino, __u64 block,
657 			      const char *func, unsigned int line)
658 {
659 	journal_t *journal = EXT4_SB(sb)->s_journal;
660 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
661 
662 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
663 	if (test_opt(sb, WARN_ON_ERROR))
664 		WARN_ON_ONCE(1);
665 
666 	if (!continue_fs && !sb_rdonly(sb)) {
667 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
668 		if (journal)
669 			jbd2_journal_abort(journal, -EIO);
670 	}
671 
672 	if (!bdev_read_only(sb->s_bdev)) {
673 		save_error_info(sb, error, ino, block, func, line);
674 		/*
675 		 * In case the fs should keep running, we need to writeout
676 		 * superblock through the journal. Due to lock ordering
677 		 * constraints, it may not be safe to do it right here so we
678 		 * defer superblock flushing to a workqueue.
679 		 */
680 		if (continue_fs && journal)
681 			schedule_work(&EXT4_SB(sb)->s_error_work);
682 		else
683 			ext4_commit_super(sb);
684 	}
685 
686 	/*
687 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
688 	 * could panic during 'reboot -f' as the underlying device got already
689 	 * disabled.
690 	 */
691 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
692 		panic("EXT4-fs (device %s): panic forced after error\n",
693 			sb->s_id);
694 	}
695 
696 	if (sb_rdonly(sb) || continue_fs)
697 		return;
698 
699 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
700 	/*
701 	 * Make sure updated value of ->s_mount_flags will be visible before
702 	 * ->s_flags update
703 	 */
704 	smp_wmb();
705 	sb->s_flags |= SB_RDONLY;
706 }
707 
708 static void flush_stashed_error_work(struct work_struct *work)
709 {
710 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
711 						s_error_work);
712 	journal_t *journal = sbi->s_journal;
713 	handle_t *handle;
714 
715 	/*
716 	 * If the journal is still running, we have to write out superblock
717 	 * through the journal to avoid collisions of other journalled sb
718 	 * updates.
719 	 *
720 	 * We use directly jbd2 functions here to avoid recursing back into
721 	 * ext4 error handling code during handling of previous errors.
722 	 */
723 	if (!sb_rdonly(sbi->s_sb) && journal) {
724 		struct buffer_head *sbh = sbi->s_sbh;
725 		handle = jbd2_journal_start(journal, 1);
726 		if (IS_ERR(handle))
727 			goto write_directly;
728 		if (jbd2_journal_get_write_access(handle, sbh)) {
729 			jbd2_journal_stop(handle);
730 			goto write_directly;
731 		}
732 		ext4_update_super(sbi->s_sb);
733 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
734 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
735 				 "superblock detected");
736 			clear_buffer_write_io_error(sbh);
737 			set_buffer_uptodate(sbh);
738 		}
739 
740 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
741 			jbd2_journal_stop(handle);
742 			goto write_directly;
743 		}
744 		jbd2_journal_stop(handle);
745 		ext4_notify_error_sysfs(sbi);
746 		return;
747 	}
748 write_directly:
749 	/*
750 	 * Write through journal failed. Write sb directly to get error info
751 	 * out and hope for the best.
752 	 */
753 	ext4_commit_super(sbi->s_sb);
754 	ext4_notify_error_sysfs(sbi);
755 }
756 
757 #define ext4_error_ratelimit(sb)					\
758 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
759 			     "EXT4-fs error")
760 
761 void __ext4_error(struct super_block *sb, const char *function,
762 		  unsigned int line, bool force_ro, int error, __u64 block,
763 		  const char *fmt, ...)
764 {
765 	struct va_format vaf;
766 	va_list args;
767 
768 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
769 		return;
770 
771 	trace_ext4_error(sb, function, line);
772 	if (ext4_error_ratelimit(sb)) {
773 		va_start(args, fmt);
774 		vaf.fmt = fmt;
775 		vaf.va = &args;
776 		printk(KERN_CRIT
777 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
778 		       sb->s_id, function, line, current->comm, &vaf);
779 		va_end(args);
780 	}
781 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
782 
783 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
784 }
785 
786 void __ext4_error_inode(struct inode *inode, const char *function,
787 			unsigned int line, ext4_fsblk_t block, int error,
788 			const char *fmt, ...)
789 {
790 	va_list args;
791 	struct va_format vaf;
792 
793 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
794 		return;
795 
796 	trace_ext4_error(inode->i_sb, function, line);
797 	if (ext4_error_ratelimit(inode->i_sb)) {
798 		va_start(args, fmt);
799 		vaf.fmt = fmt;
800 		vaf.va = &args;
801 		if (block)
802 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
803 			       "inode #%lu: block %llu: comm %s: %pV\n",
804 			       inode->i_sb->s_id, function, line, inode->i_ino,
805 			       block, current->comm, &vaf);
806 		else
807 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
808 			       "inode #%lu: comm %s: %pV\n",
809 			       inode->i_sb->s_id, function, line, inode->i_ino,
810 			       current->comm, &vaf);
811 		va_end(args);
812 	}
813 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
814 
815 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
816 			  function, line);
817 }
818 
819 void __ext4_error_file(struct file *file, const char *function,
820 		       unsigned int line, ext4_fsblk_t block,
821 		       const char *fmt, ...)
822 {
823 	va_list args;
824 	struct va_format vaf;
825 	struct inode *inode = file_inode(file);
826 	char pathname[80], *path;
827 
828 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
829 		return;
830 
831 	trace_ext4_error(inode->i_sb, function, line);
832 	if (ext4_error_ratelimit(inode->i_sb)) {
833 		path = file_path(file, pathname, sizeof(pathname));
834 		if (IS_ERR(path))
835 			path = "(unknown)";
836 		va_start(args, fmt);
837 		vaf.fmt = fmt;
838 		vaf.va = &args;
839 		if (block)
840 			printk(KERN_CRIT
841 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
842 			       "block %llu: comm %s: path %s: %pV\n",
843 			       inode->i_sb->s_id, function, line, inode->i_ino,
844 			       block, current->comm, path, &vaf);
845 		else
846 			printk(KERN_CRIT
847 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
848 			       "comm %s: path %s: %pV\n",
849 			       inode->i_sb->s_id, function, line, inode->i_ino,
850 			       current->comm, path, &vaf);
851 		va_end(args);
852 	}
853 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
854 
855 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
856 			  function, line);
857 }
858 
859 const char *ext4_decode_error(struct super_block *sb, int errno,
860 			      char nbuf[16])
861 {
862 	char *errstr = NULL;
863 
864 	switch (errno) {
865 	case -EFSCORRUPTED:
866 		errstr = "Corrupt filesystem";
867 		break;
868 	case -EFSBADCRC:
869 		errstr = "Filesystem failed CRC";
870 		break;
871 	case -EIO:
872 		errstr = "IO failure";
873 		break;
874 	case -ENOMEM:
875 		errstr = "Out of memory";
876 		break;
877 	case -EROFS:
878 		if (!sb || (EXT4_SB(sb)->s_journal &&
879 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
880 			errstr = "Journal has aborted";
881 		else
882 			errstr = "Readonly filesystem";
883 		break;
884 	default:
885 		/* If the caller passed in an extra buffer for unknown
886 		 * errors, textualise them now.  Else we just return
887 		 * NULL. */
888 		if (nbuf) {
889 			/* Check for truncated error codes... */
890 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
891 				errstr = nbuf;
892 		}
893 		break;
894 	}
895 
896 	return errstr;
897 }
898 
899 /* __ext4_std_error decodes expected errors from journaling functions
900  * automatically and invokes the appropriate error response.  */
901 
902 void __ext4_std_error(struct super_block *sb, const char *function,
903 		      unsigned int line, int errno)
904 {
905 	char nbuf[16];
906 	const char *errstr;
907 
908 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
909 		return;
910 
911 	/* Special case: if the error is EROFS, and we're not already
912 	 * inside a transaction, then there's really no point in logging
913 	 * an error. */
914 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
915 		return;
916 
917 	if (ext4_error_ratelimit(sb)) {
918 		errstr = ext4_decode_error(sb, errno, nbuf);
919 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
920 		       sb->s_id, function, line, errstr);
921 	}
922 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
923 
924 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
925 }
926 
927 void __ext4_msg(struct super_block *sb,
928 		const char *prefix, const char *fmt, ...)
929 {
930 	struct va_format vaf;
931 	va_list args;
932 
933 	if (sb) {
934 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
935 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
936 				  "EXT4-fs"))
937 			return;
938 	}
939 
940 	va_start(args, fmt);
941 	vaf.fmt = fmt;
942 	vaf.va = &args;
943 	if (sb)
944 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
945 	else
946 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
947 	va_end(args);
948 }
949 
950 static int ext4_warning_ratelimit(struct super_block *sb)
951 {
952 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
953 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
954 			    "EXT4-fs warning");
955 }
956 
957 void __ext4_warning(struct super_block *sb, const char *function,
958 		    unsigned int line, const char *fmt, ...)
959 {
960 	struct va_format vaf;
961 	va_list args;
962 
963 	if (!ext4_warning_ratelimit(sb))
964 		return;
965 
966 	va_start(args, fmt);
967 	vaf.fmt = fmt;
968 	vaf.va = &args;
969 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
970 	       sb->s_id, function, line, &vaf);
971 	va_end(args);
972 }
973 
974 void __ext4_warning_inode(const struct inode *inode, const char *function,
975 			  unsigned int line, const char *fmt, ...)
976 {
977 	struct va_format vaf;
978 	va_list args;
979 
980 	if (!ext4_warning_ratelimit(inode->i_sb))
981 		return;
982 
983 	va_start(args, fmt);
984 	vaf.fmt = fmt;
985 	vaf.va = &args;
986 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
987 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
988 	       function, line, inode->i_ino, current->comm, &vaf);
989 	va_end(args);
990 }
991 
992 void __ext4_grp_locked_error(const char *function, unsigned int line,
993 			     struct super_block *sb, ext4_group_t grp,
994 			     unsigned long ino, ext4_fsblk_t block,
995 			     const char *fmt, ...)
996 __releases(bitlock)
997 __acquires(bitlock)
998 {
999 	struct va_format vaf;
1000 	va_list args;
1001 
1002 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
1003 		return;
1004 
1005 	trace_ext4_error(sb, function, line);
1006 	if (ext4_error_ratelimit(sb)) {
1007 		va_start(args, fmt);
1008 		vaf.fmt = fmt;
1009 		vaf.va = &args;
1010 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1011 		       sb->s_id, function, line, grp);
1012 		if (ino)
1013 			printk(KERN_CONT "inode %lu: ", ino);
1014 		if (block)
1015 			printk(KERN_CONT "block %llu:",
1016 			       (unsigned long long) block);
1017 		printk(KERN_CONT "%pV\n", &vaf);
1018 		va_end(args);
1019 	}
1020 
1021 	if (test_opt(sb, ERRORS_CONT)) {
1022 		if (test_opt(sb, WARN_ON_ERROR))
1023 			WARN_ON_ONCE(1);
1024 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1025 		if (!bdev_read_only(sb->s_bdev)) {
1026 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1027 					line);
1028 			schedule_work(&EXT4_SB(sb)->s_error_work);
1029 		}
1030 		return;
1031 	}
1032 	ext4_unlock_group(sb, grp);
1033 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1034 	/*
1035 	 * We only get here in the ERRORS_RO case; relocking the group
1036 	 * may be dangerous, but nothing bad will happen since the
1037 	 * filesystem will have already been marked read/only and the
1038 	 * journal has been aborted.  We return 1 as a hint to callers
1039 	 * who might what to use the return value from
1040 	 * ext4_grp_locked_error() to distinguish between the
1041 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1042 	 * aggressively from the ext4 function in question, with a
1043 	 * more appropriate error code.
1044 	 */
1045 	ext4_lock_group(sb, grp);
1046 	return;
1047 }
1048 
1049 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1050 				     ext4_group_t group,
1051 				     unsigned int flags)
1052 {
1053 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1054 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1055 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1056 	int ret;
1057 
1058 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1059 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1060 					    &grp->bb_state);
1061 		if (!ret)
1062 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1063 					   grp->bb_free);
1064 	}
1065 
1066 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1067 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1068 					    &grp->bb_state);
1069 		if (!ret && gdp) {
1070 			int count;
1071 
1072 			count = ext4_free_inodes_count(sb, gdp);
1073 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1074 					   count);
1075 		}
1076 	}
1077 }
1078 
1079 void ext4_update_dynamic_rev(struct super_block *sb)
1080 {
1081 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1082 
1083 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1084 		return;
1085 
1086 	ext4_warning(sb,
1087 		     "updating to rev %d because of new feature flag, "
1088 		     "running e2fsck is recommended",
1089 		     EXT4_DYNAMIC_REV);
1090 
1091 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1092 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1093 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1094 	/* leave es->s_feature_*compat flags alone */
1095 	/* es->s_uuid will be set by e2fsck if empty */
1096 
1097 	/*
1098 	 * The rest of the superblock fields should be zero, and if not it
1099 	 * means they are likely already in use, so leave them alone.  We
1100 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1101 	 */
1102 }
1103 
1104 /*
1105  * Open the external journal device
1106  */
1107 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1108 {
1109 	struct block_device *bdev;
1110 
1111 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1112 	if (IS_ERR(bdev))
1113 		goto fail;
1114 	return bdev;
1115 
1116 fail:
1117 	ext4_msg(sb, KERN_ERR,
1118 		 "failed to open journal device unknown-block(%u,%u) %ld",
1119 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1120 	return NULL;
1121 }
1122 
1123 /*
1124  * Release the journal device
1125  */
1126 static void ext4_blkdev_put(struct block_device *bdev)
1127 {
1128 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1129 }
1130 
1131 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1132 {
1133 	struct block_device *bdev;
1134 	bdev = sbi->s_journal_bdev;
1135 	if (bdev) {
1136 		ext4_blkdev_put(bdev);
1137 		sbi->s_journal_bdev = NULL;
1138 	}
1139 }
1140 
1141 static inline struct inode *orphan_list_entry(struct list_head *l)
1142 {
1143 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1144 }
1145 
1146 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1147 {
1148 	struct list_head *l;
1149 
1150 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1151 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1152 
1153 	printk(KERN_ERR "sb_info orphan list:\n");
1154 	list_for_each(l, &sbi->s_orphan) {
1155 		struct inode *inode = orphan_list_entry(l);
1156 		printk(KERN_ERR "  "
1157 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1158 		       inode->i_sb->s_id, inode->i_ino, inode,
1159 		       inode->i_mode, inode->i_nlink,
1160 		       NEXT_ORPHAN(inode));
1161 	}
1162 }
1163 
1164 #ifdef CONFIG_QUOTA
1165 static int ext4_quota_off(struct super_block *sb, int type);
1166 
1167 static inline void ext4_quota_off_umount(struct super_block *sb)
1168 {
1169 	int type;
1170 
1171 	/* Use our quota_off function to clear inode flags etc. */
1172 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1173 		ext4_quota_off(sb, type);
1174 }
1175 
1176 /*
1177  * This is a helper function which is used in the mount/remount
1178  * codepaths (which holds s_umount) to fetch the quota file name.
1179  */
1180 static inline char *get_qf_name(struct super_block *sb,
1181 				struct ext4_sb_info *sbi,
1182 				int type)
1183 {
1184 	return rcu_dereference_protected(sbi->s_qf_names[type],
1185 					 lockdep_is_held(&sb->s_umount));
1186 }
1187 #else
1188 static inline void ext4_quota_off_umount(struct super_block *sb)
1189 {
1190 }
1191 #endif
1192 
1193 static void ext4_put_super(struct super_block *sb)
1194 {
1195 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1196 	struct ext4_super_block *es = sbi->s_es;
1197 	struct buffer_head **group_desc;
1198 	struct flex_groups **flex_groups;
1199 	int aborted = 0;
1200 	int i, err;
1201 
1202 	ext4_unregister_li_request(sb);
1203 	ext4_quota_off_umount(sb);
1204 
1205 	flush_work(&sbi->s_error_work);
1206 	destroy_workqueue(sbi->rsv_conversion_wq);
1207 	ext4_release_orphan_info(sb);
1208 
1209 	/*
1210 	 * Unregister sysfs before destroying jbd2 journal.
1211 	 * Since we could still access attr_journal_task attribute via sysfs
1212 	 * path which could have sbi->s_journal->j_task as NULL
1213 	 */
1214 	ext4_unregister_sysfs(sb);
1215 
1216 	if (sbi->s_journal) {
1217 		aborted = is_journal_aborted(sbi->s_journal);
1218 		err = jbd2_journal_destroy(sbi->s_journal);
1219 		sbi->s_journal = NULL;
1220 		if ((err < 0) && !aborted) {
1221 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1222 		}
1223 	}
1224 
1225 	ext4_es_unregister_shrinker(sbi);
1226 	del_timer_sync(&sbi->s_err_report);
1227 	ext4_release_system_zone(sb);
1228 	ext4_mb_release(sb);
1229 	ext4_ext_release(sb);
1230 
1231 	if (!sb_rdonly(sb) && !aborted) {
1232 		ext4_clear_feature_journal_needs_recovery(sb);
1233 		ext4_clear_feature_orphan_present(sb);
1234 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1235 	}
1236 	if (!sb_rdonly(sb))
1237 		ext4_commit_super(sb);
1238 
1239 	rcu_read_lock();
1240 	group_desc = rcu_dereference(sbi->s_group_desc);
1241 	for (i = 0; i < sbi->s_gdb_count; i++)
1242 		brelse(group_desc[i]);
1243 	kvfree(group_desc);
1244 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1245 	if (flex_groups) {
1246 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1247 			kvfree(flex_groups[i]);
1248 		kvfree(flex_groups);
1249 	}
1250 	rcu_read_unlock();
1251 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1252 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1253 	percpu_counter_destroy(&sbi->s_dirs_counter);
1254 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1255 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1256 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1257 #ifdef CONFIG_QUOTA
1258 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1259 		kfree(get_qf_name(sb, sbi, i));
1260 #endif
1261 
1262 	/* Debugging code just in case the in-memory inode orphan list
1263 	 * isn't empty.  The on-disk one can be non-empty if we've
1264 	 * detected an error and taken the fs readonly, but the
1265 	 * in-memory list had better be clean by this point. */
1266 	if (!list_empty(&sbi->s_orphan))
1267 		dump_orphan_list(sb, sbi);
1268 	ASSERT(list_empty(&sbi->s_orphan));
1269 
1270 	sync_blockdev(sb->s_bdev);
1271 	invalidate_bdev(sb->s_bdev);
1272 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1273 		/*
1274 		 * Invalidate the journal device's buffers.  We don't want them
1275 		 * floating about in memory - the physical journal device may
1276 		 * hotswapped, and it breaks the `ro-after' testing code.
1277 		 */
1278 		sync_blockdev(sbi->s_journal_bdev);
1279 		invalidate_bdev(sbi->s_journal_bdev);
1280 		ext4_blkdev_remove(sbi);
1281 	}
1282 
1283 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1284 	sbi->s_ea_inode_cache = NULL;
1285 
1286 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1287 	sbi->s_ea_block_cache = NULL;
1288 
1289 	ext4_stop_mmpd(sbi);
1290 
1291 	brelse(sbi->s_sbh);
1292 	sb->s_fs_info = NULL;
1293 	/*
1294 	 * Now that we are completely done shutting down the
1295 	 * superblock, we need to actually destroy the kobject.
1296 	 */
1297 	kobject_put(&sbi->s_kobj);
1298 	wait_for_completion(&sbi->s_kobj_unregister);
1299 	if (sbi->s_chksum_driver)
1300 		crypto_free_shash(sbi->s_chksum_driver);
1301 	kfree(sbi->s_blockgroup_lock);
1302 	fs_put_dax(sbi->s_daxdev);
1303 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1304 #if IS_ENABLED(CONFIG_UNICODE)
1305 	utf8_unload(sb->s_encoding);
1306 #endif
1307 	kfree(sbi);
1308 }
1309 
1310 static struct kmem_cache *ext4_inode_cachep;
1311 
1312 /*
1313  * Called inside transaction, so use GFP_NOFS
1314  */
1315 static struct inode *ext4_alloc_inode(struct super_block *sb)
1316 {
1317 	struct ext4_inode_info *ei;
1318 
1319 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1320 	if (!ei)
1321 		return NULL;
1322 
1323 	inode_set_iversion(&ei->vfs_inode, 1);
1324 	spin_lock_init(&ei->i_raw_lock);
1325 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1326 	atomic_set(&ei->i_prealloc_active, 0);
1327 	spin_lock_init(&ei->i_prealloc_lock);
1328 	ext4_es_init_tree(&ei->i_es_tree);
1329 	rwlock_init(&ei->i_es_lock);
1330 	INIT_LIST_HEAD(&ei->i_es_list);
1331 	ei->i_es_all_nr = 0;
1332 	ei->i_es_shk_nr = 0;
1333 	ei->i_es_shrink_lblk = 0;
1334 	ei->i_reserved_data_blocks = 0;
1335 	spin_lock_init(&(ei->i_block_reservation_lock));
1336 	ext4_init_pending_tree(&ei->i_pending_tree);
1337 #ifdef CONFIG_QUOTA
1338 	ei->i_reserved_quota = 0;
1339 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1340 #endif
1341 	ei->jinode = NULL;
1342 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1343 	spin_lock_init(&ei->i_completed_io_lock);
1344 	ei->i_sync_tid = 0;
1345 	ei->i_datasync_tid = 0;
1346 	atomic_set(&ei->i_unwritten, 0);
1347 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1348 	ext4_fc_init_inode(&ei->vfs_inode);
1349 	mutex_init(&ei->i_fc_lock);
1350 	return &ei->vfs_inode;
1351 }
1352 
1353 static int ext4_drop_inode(struct inode *inode)
1354 {
1355 	int drop = generic_drop_inode(inode);
1356 
1357 	if (!drop)
1358 		drop = fscrypt_drop_inode(inode);
1359 
1360 	trace_ext4_drop_inode(inode, drop);
1361 	return drop;
1362 }
1363 
1364 static void ext4_free_in_core_inode(struct inode *inode)
1365 {
1366 	fscrypt_free_inode(inode);
1367 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1368 		pr_warn("%s: inode %ld still in fc list",
1369 			__func__, inode->i_ino);
1370 	}
1371 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1372 }
1373 
1374 static void ext4_destroy_inode(struct inode *inode)
1375 {
1376 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1377 		ext4_msg(inode->i_sb, KERN_ERR,
1378 			 "Inode %lu (%p): orphan list check failed!",
1379 			 inode->i_ino, EXT4_I(inode));
1380 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1381 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1382 				true);
1383 		dump_stack();
1384 	}
1385 
1386 	if (EXT4_I(inode)->i_reserved_data_blocks)
1387 		ext4_msg(inode->i_sb, KERN_ERR,
1388 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1389 			 inode->i_ino, EXT4_I(inode),
1390 			 EXT4_I(inode)->i_reserved_data_blocks);
1391 }
1392 
1393 static void init_once(void *foo)
1394 {
1395 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1396 
1397 	INIT_LIST_HEAD(&ei->i_orphan);
1398 	init_rwsem(&ei->xattr_sem);
1399 	init_rwsem(&ei->i_data_sem);
1400 	inode_init_once(&ei->vfs_inode);
1401 	ext4_fc_init_inode(&ei->vfs_inode);
1402 }
1403 
1404 static int __init init_inodecache(void)
1405 {
1406 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1407 				sizeof(struct ext4_inode_info), 0,
1408 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1409 					SLAB_ACCOUNT),
1410 				offsetof(struct ext4_inode_info, i_data),
1411 				sizeof_field(struct ext4_inode_info, i_data),
1412 				init_once);
1413 	if (ext4_inode_cachep == NULL)
1414 		return -ENOMEM;
1415 	return 0;
1416 }
1417 
1418 static void destroy_inodecache(void)
1419 {
1420 	/*
1421 	 * Make sure all delayed rcu free inodes are flushed before we
1422 	 * destroy cache.
1423 	 */
1424 	rcu_barrier();
1425 	kmem_cache_destroy(ext4_inode_cachep);
1426 }
1427 
1428 void ext4_clear_inode(struct inode *inode)
1429 {
1430 	ext4_fc_del(inode);
1431 	invalidate_inode_buffers(inode);
1432 	clear_inode(inode);
1433 	ext4_discard_preallocations(inode, 0);
1434 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1435 	dquot_drop(inode);
1436 	if (EXT4_I(inode)->jinode) {
1437 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1438 					       EXT4_I(inode)->jinode);
1439 		jbd2_free_inode(EXT4_I(inode)->jinode);
1440 		EXT4_I(inode)->jinode = NULL;
1441 	}
1442 	fscrypt_put_encryption_info(inode);
1443 	fsverity_cleanup_inode(inode);
1444 }
1445 
1446 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1447 					u64 ino, u32 generation)
1448 {
1449 	struct inode *inode;
1450 
1451 	/*
1452 	 * Currently we don't know the generation for parent directory, so
1453 	 * a generation of 0 means "accept any"
1454 	 */
1455 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1456 	if (IS_ERR(inode))
1457 		return ERR_CAST(inode);
1458 	if (generation && inode->i_generation != generation) {
1459 		iput(inode);
1460 		return ERR_PTR(-ESTALE);
1461 	}
1462 
1463 	return inode;
1464 }
1465 
1466 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1467 					int fh_len, int fh_type)
1468 {
1469 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1470 				    ext4_nfs_get_inode);
1471 }
1472 
1473 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1474 					int fh_len, int fh_type)
1475 {
1476 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1477 				    ext4_nfs_get_inode);
1478 }
1479 
1480 static int ext4_nfs_commit_metadata(struct inode *inode)
1481 {
1482 	struct writeback_control wbc = {
1483 		.sync_mode = WB_SYNC_ALL
1484 	};
1485 
1486 	trace_ext4_nfs_commit_metadata(inode);
1487 	return ext4_write_inode(inode, &wbc);
1488 }
1489 
1490 #ifdef CONFIG_FS_ENCRYPTION
1491 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1492 {
1493 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1494 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1495 }
1496 
1497 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1498 							void *fs_data)
1499 {
1500 	handle_t *handle = fs_data;
1501 	int res, res2, credits, retries = 0;
1502 
1503 	/*
1504 	 * Encrypting the root directory is not allowed because e2fsck expects
1505 	 * lost+found to exist and be unencrypted, and encrypting the root
1506 	 * directory would imply encrypting the lost+found directory as well as
1507 	 * the filename "lost+found" itself.
1508 	 */
1509 	if (inode->i_ino == EXT4_ROOT_INO)
1510 		return -EPERM;
1511 
1512 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1513 		return -EINVAL;
1514 
1515 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1516 		return -EOPNOTSUPP;
1517 
1518 	res = ext4_convert_inline_data(inode);
1519 	if (res)
1520 		return res;
1521 
1522 	/*
1523 	 * If a journal handle was specified, then the encryption context is
1524 	 * being set on a new inode via inheritance and is part of a larger
1525 	 * transaction to create the inode.  Otherwise the encryption context is
1526 	 * being set on an existing inode in its own transaction.  Only in the
1527 	 * latter case should the "retry on ENOSPC" logic be used.
1528 	 */
1529 
1530 	if (handle) {
1531 		res = ext4_xattr_set_handle(handle, inode,
1532 					    EXT4_XATTR_INDEX_ENCRYPTION,
1533 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1534 					    ctx, len, 0);
1535 		if (!res) {
1536 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1537 			ext4_clear_inode_state(inode,
1538 					EXT4_STATE_MAY_INLINE_DATA);
1539 			/*
1540 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1541 			 * S_DAX may be disabled
1542 			 */
1543 			ext4_set_inode_flags(inode, false);
1544 		}
1545 		return res;
1546 	}
1547 
1548 	res = dquot_initialize(inode);
1549 	if (res)
1550 		return res;
1551 retry:
1552 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1553 				     &credits);
1554 	if (res)
1555 		return res;
1556 
1557 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1558 	if (IS_ERR(handle))
1559 		return PTR_ERR(handle);
1560 
1561 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1562 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1563 				    ctx, len, 0);
1564 	if (!res) {
1565 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1566 		/*
1567 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1568 		 * S_DAX may be disabled
1569 		 */
1570 		ext4_set_inode_flags(inode, false);
1571 		res = ext4_mark_inode_dirty(handle, inode);
1572 		if (res)
1573 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1574 	}
1575 	res2 = ext4_journal_stop(handle);
1576 
1577 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1578 		goto retry;
1579 	if (!res)
1580 		res = res2;
1581 	return res;
1582 }
1583 
1584 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1585 {
1586 	return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1587 }
1588 
1589 static bool ext4_has_stable_inodes(struct super_block *sb)
1590 {
1591 	return ext4_has_feature_stable_inodes(sb);
1592 }
1593 
1594 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1595 				       int *ino_bits_ret, int *lblk_bits_ret)
1596 {
1597 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1598 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1599 }
1600 
1601 static const struct fscrypt_operations ext4_cryptops = {
1602 	.key_prefix		= "ext4:",
1603 	.get_context		= ext4_get_context,
1604 	.set_context		= ext4_set_context,
1605 	.get_dummy_policy	= ext4_get_dummy_policy,
1606 	.empty_dir		= ext4_empty_dir,
1607 	.has_stable_inodes	= ext4_has_stable_inodes,
1608 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1609 };
1610 #endif
1611 
1612 #ifdef CONFIG_QUOTA
1613 static const char * const quotatypes[] = INITQFNAMES;
1614 #define QTYPE2NAME(t) (quotatypes[t])
1615 
1616 static int ext4_write_dquot(struct dquot *dquot);
1617 static int ext4_acquire_dquot(struct dquot *dquot);
1618 static int ext4_release_dquot(struct dquot *dquot);
1619 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1620 static int ext4_write_info(struct super_block *sb, int type);
1621 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1622 			 const struct path *path);
1623 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1624 			       size_t len, loff_t off);
1625 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1626 				const char *data, size_t len, loff_t off);
1627 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1628 			     unsigned int flags);
1629 
1630 static struct dquot **ext4_get_dquots(struct inode *inode)
1631 {
1632 	return EXT4_I(inode)->i_dquot;
1633 }
1634 
1635 static const struct dquot_operations ext4_quota_operations = {
1636 	.get_reserved_space	= ext4_get_reserved_space,
1637 	.write_dquot		= ext4_write_dquot,
1638 	.acquire_dquot		= ext4_acquire_dquot,
1639 	.release_dquot		= ext4_release_dquot,
1640 	.mark_dirty		= ext4_mark_dquot_dirty,
1641 	.write_info		= ext4_write_info,
1642 	.alloc_dquot		= dquot_alloc,
1643 	.destroy_dquot		= dquot_destroy,
1644 	.get_projid		= ext4_get_projid,
1645 	.get_inode_usage	= ext4_get_inode_usage,
1646 	.get_next_id		= dquot_get_next_id,
1647 };
1648 
1649 static const struct quotactl_ops ext4_qctl_operations = {
1650 	.quota_on	= ext4_quota_on,
1651 	.quota_off	= ext4_quota_off,
1652 	.quota_sync	= dquot_quota_sync,
1653 	.get_state	= dquot_get_state,
1654 	.set_info	= dquot_set_dqinfo,
1655 	.get_dqblk	= dquot_get_dqblk,
1656 	.set_dqblk	= dquot_set_dqblk,
1657 	.get_nextdqblk	= dquot_get_next_dqblk,
1658 };
1659 #endif
1660 
1661 static const struct super_operations ext4_sops = {
1662 	.alloc_inode	= ext4_alloc_inode,
1663 	.free_inode	= ext4_free_in_core_inode,
1664 	.destroy_inode	= ext4_destroy_inode,
1665 	.write_inode	= ext4_write_inode,
1666 	.dirty_inode	= ext4_dirty_inode,
1667 	.drop_inode	= ext4_drop_inode,
1668 	.evict_inode	= ext4_evict_inode,
1669 	.put_super	= ext4_put_super,
1670 	.sync_fs	= ext4_sync_fs,
1671 	.freeze_fs	= ext4_freeze,
1672 	.unfreeze_fs	= ext4_unfreeze,
1673 	.statfs		= ext4_statfs,
1674 	.show_options	= ext4_show_options,
1675 #ifdef CONFIG_QUOTA
1676 	.quota_read	= ext4_quota_read,
1677 	.quota_write	= ext4_quota_write,
1678 	.get_dquots	= ext4_get_dquots,
1679 #endif
1680 };
1681 
1682 static const struct export_operations ext4_export_ops = {
1683 	.fh_to_dentry = ext4_fh_to_dentry,
1684 	.fh_to_parent = ext4_fh_to_parent,
1685 	.get_parent = ext4_get_parent,
1686 	.commit_metadata = ext4_nfs_commit_metadata,
1687 };
1688 
1689 enum {
1690 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1691 	Opt_resgid, Opt_resuid, Opt_sb,
1692 	Opt_nouid32, Opt_debug, Opt_removed,
1693 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1694 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1695 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1696 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1697 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1698 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1699 	Opt_inlinecrypt,
1700 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1701 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1702 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1703 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1704 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1705 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1706 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1707 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1708 	Opt_dioread_nolock, Opt_dioread_lock,
1709 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1710 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1711 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1712 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1713 #ifdef CONFIG_EXT4_DEBUG
1714 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1715 #endif
1716 };
1717 
1718 static const struct constant_table ext4_param_errors[] = {
1719 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1720 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1721 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1722 	{}
1723 };
1724 
1725 static const struct constant_table ext4_param_data[] = {
1726 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1727 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1728 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1729 	{}
1730 };
1731 
1732 static const struct constant_table ext4_param_data_err[] = {
1733 	{"abort",	Opt_data_err_abort},
1734 	{"ignore",	Opt_data_err_ignore},
1735 	{}
1736 };
1737 
1738 static const struct constant_table ext4_param_jqfmt[] = {
1739 	{"vfsold",	QFMT_VFS_OLD},
1740 	{"vfsv0",	QFMT_VFS_V0},
1741 	{"vfsv1",	QFMT_VFS_V1},
1742 	{}
1743 };
1744 
1745 static const struct constant_table ext4_param_dax[] = {
1746 	{"always",	Opt_dax_always},
1747 	{"inode",	Opt_dax_inode},
1748 	{"never",	Opt_dax_never},
1749 	{}
1750 };
1751 
1752 /* String parameter that allows empty argument */
1753 #define fsparam_string_empty(NAME, OPT) \
1754 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1755 
1756 /*
1757  * Mount option specification
1758  * We don't use fsparam_flag_no because of the way we set the
1759  * options and the way we show them in _ext4_show_options(). To
1760  * keep the changes to a minimum, let's keep the negative options
1761  * separate for now.
1762  */
1763 static const struct fs_parameter_spec ext4_param_specs[] = {
1764 	fsparam_flag	("bsddf",		Opt_bsd_df),
1765 	fsparam_flag	("minixdf",		Opt_minix_df),
1766 	fsparam_flag	("grpid",		Opt_grpid),
1767 	fsparam_flag	("bsdgroups",		Opt_grpid),
1768 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1769 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1770 	fsparam_u32	("resgid",		Opt_resgid),
1771 	fsparam_u32	("resuid",		Opt_resuid),
1772 	fsparam_u32	("sb",			Opt_sb),
1773 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1774 	fsparam_flag	("nouid32",		Opt_nouid32),
1775 	fsparam_flag	("debug",		Opt_debug),
1776 	fsparam_flag	("oldalloc",		Opt_removed),
1777 	fsparam_flag	("orlov",		Opt_removed),
1778 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1779 	fsparam_flag	("nouser_xattr",	Opt_nouser_xattr),
1780 	fsparam_flag	("acl",			Opt_acl),
1781 	fsparam_flag	("noacl",		Opt_noacl),
1782 	fsparam_flag	("norecovery",		Opt_noload),
1783 	fsparam_flag	("noload",		Opt_noload),
1784 	fsparam_flag	("bh",			Opt_removed),
1785 	fsparam_flag	("nobh",		Opt_removed),
1786 	fsparam_u32	("commit",		Opt_commit),
1787 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1788 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1789 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1790 	fsparam_bdev	("journal_path",	Opt_journal_path),
1791 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1792 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1793 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1794 	fsparam_flag	("abort",		Opt_abort),
1795 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1796 	fsparam_enum	("data_err",		Opt_data_err,
1797 						ext4_param_data_err),
1798 	fsparam_string_empty
1799 			("usrjquota",		Opt_usrjquota),
1800 	fsparam_string_empty
1801 			("grpjquota",		Opt_grpjquota),
1802 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1803 	fsparam_flag	("grpquota",		Opt_grpquota),
1804 	fsparam_flag	("quota",		Opt_quota),
1805 	fsparam_flag	("noquota",		Opt_noquota),
1806 	fsparam_flag	("usrquota",		Opt_usrquota),
1807 	fsparam_flag	("prjquota",		Opt_prjquota),
1808 	fsparam_flag	("barrier",		Opt_barrier),
1809 	fsparam_u32	("barrier",		Opt_barrier),
1810 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1811 	fsparam_flag	("i_version",		Opt_i_version),
1812 	fsparam_flag	("dax",			Opt_dax),
1813 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1814 	fsparam_u32	("stripe",		Opt_stripe),
1815 	fsparam_flag	("delalloc",		Opt_delalloc),
1816 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1817 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1818 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1819 	fsparam_u32	("debug_want_extra_isize",
1820 						Opt_debug_want_extra_isize),
1821 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1822 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1823 	fsparam_flag	("block_validity",	Opt_block_validity),
1824 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1825 	fsparam_u32	("inode_readahead_blks",
1826 						Opt_inode_readahead_blks),
1827 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1828 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1829 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1830 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1831 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1832 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1833 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1834 	fsparam_flag	("discard",		Opt_discard),
1835 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1836 	fsparam_u32	("init_itable",		Opt_init_itable),
1837 	fsparam_flag	("init_itable",		Opt_init_itable),
1838 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1839 #ifdef CONFIG_EXT4_DEBUG
1840 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1841 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1842 #endif
1843 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1844 	fsparam_flag	("test_dummy_encryption",
1845 						Opt_test_dummy_encryption),
1846 	fsparam_string	("test_dummy_encryption",
1847 						Opt_test_dummy_encryption),
1848 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1849 	fsparam_flag	("nombcache",		Opt_nombcache),
1850 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1851 	fsparam_flag	("prefetch_block_bitmaps",
1852 						Opt_removed),
1853 	fsparam_flag	("no_prefetch_block_bitmaps",
1854 						Opt_no_prefetch_block_bitmaps),
1855 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1856 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1857 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1858 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1859 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1860 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1861 	{}
1862 };
1863 
1864 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1865 #define DEFAULT_MB_OPTIMIZE_SCAN	(-1)
1866 
1867 static const char deprecated_msg[] =
1868 	"Mount option \"%s\" will be removed by %s\n"
1869 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1870 
1871 #define MOPT_SET	0x0001
1872 #define MOPT_CLEAR	0x0002
1873 #define MOPT_NOSUPPORT	0x0004
1874 #define MOPT_EXPLICIT	0x0008
1875 #ifdef CONFIG_QUOTA
1876 #define MOPT_Q		0
1877 #define MOPT_QFMT	0x0010
1878 #else
1879 #define MOPT_Q		MOPT_NOSUPPORT
1880 #define MOPT_QFMT	MOPT_NOSUPPORT
1881 #endif
1882 #define MOPT_NO_EXT2	0x0020
1883 #define MOPT_NO_EXT3	0x0040
1884 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1885 #define MOPT_SKIP	0x0080
1886 #define	MOPT_2		0x0100
1887 
1888 static const struct mount_opts {
1889 	int	token;
1890 	int	mount_opt;
1891 	int	flags;
1892 } ext4_mount_opts[] = {
1893 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1894 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1895 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1896 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1897 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1898 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1899 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1900 	 MOPT_EXT4_ONLY | MOPT_SET},
1901 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1902 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1903 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1904 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1905 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1906 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1907 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1908 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1909 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1910 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1911 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1912 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1913 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1914 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1915 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1916 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1917 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1918 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1919 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1920 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1921 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1922 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1923 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1924 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1925 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1926 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1927 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1928 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1929 	{Opt_data, 0, MOPT_NO_EXT2},
1930 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1931 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1932 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1933 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1934 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1935 #else
1936 	{Opt_acl, 0, MOPT_NOSUPPORT},
1937 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1938 #endif
1939 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1940 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1941 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1942 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1943 							MOPT_SET | MOPT_Q},
1944 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1945 							MOPT_SET | MOPT_Q},
1946 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1947 							MOPT_SET | MOPT_Q},
1948 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1949 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1950 							MOPT_CLEAR | MOPT_Q},
1951 	{Opt_usrjquota, 0, MOPT_Q},
1952 	{Opt_grpjquota, 0, MOPT_Q},
1953 	{Opt_jqfmt, 0, MOPT_QFMT},
1954 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1955 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1956 	 MOPT_SET},
1957 #ifdef CONFIG_EXT4_DEBUG
1958 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1959 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1960 #endif
1961 	{Opt_err, 0, 0}
1962 };
1963 
1964 #if IS_ENABLED(CONFIG_UNICODE)
1965 static const struct ext4_sb_encodings {
1966 	__u16 magic;
1967 	char *name;
1968 	unsigned int version;
1969 } ext4_sb_encoding_map[] = {
1970 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1971 };
1972 
1973 static const struct ext4_sb_encodings *
1974 ext4_sb_read_encoding(const struct ext4_super_block *es)
1975 {
1976 	__u16 magic = le16_to_cpu(es->s_encoding);
1977 	int i;
1978 
1979 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1980 		if (magic == ext4_sb_encoding_map[i].magic)
1981 			return &ext4_sb_encoding_map[i];
1982 
1983 	return NULL;
1984 }
1985 #endif
1986 
1987 static int ext4_set_test_dummy_encryption(struct super_block *sb, char *arg)
1988 {
1989 #ifdef CONFIG_FS_ENCRYPTION
1990 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1991 	int err;
1992 
1993 	err = fscrypt_set_test_dummy_encryption(sb, arg,
1994 						&sbi->s_dummy_enc_policy);
1995 	if (err) {
1996 		ext4_msg(sb, KERN_WARNING,
1997 			 "Error while setting test dummy encryption [%d]", err);
1998 		return err;
1999 	}
2000 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2001 #endif
2002 	return 0;
2003 }
2004 
2005 #define EXT4_SPEC_JQUOTA			(1 <<  0)
2006 #define EXT4_SPEC_JQFMT				(1 <<  1)
2007 #define EXT4_SPEC_DATAJ				(1 <<  2)
2008 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
2009 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
2010 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
2011 #define EXT4_SPEC_DUMMY_ENCRYPTION		(1 <<  6)
2012 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
2013 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
2014 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
2015 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
2016 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
2017 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
2018 #define EXT4_SPEC_s_stripe			(1 << 13)
2019 #define EXT4_SPEC_s_resuid			(1 << 14)
2020 #define EXT4_SPEC_s_resgid			(1 << 15)
2021 #define EXT4_SPEC_s_commit_interval		(1 << 16)
2022 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
2023 #define EXT4_SPEC_s_sb_block			(1 << 18)
2024 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
2025 
2026 struct ext4_fs_context {
2027 	char		*s_qf_names[EXT4_MAXQUOTAS];
2028 	char		*test_dummy_enc_arg;
2029 	int		s_jquota_fmt;	/* Format of quota to use */
2030 #ifdef CONFIG_EXT4_DEBUG
2031 	int s_fc_debug_max_replay;
2032 #endif
2033 	unsigned short	qname_spec;
2034 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
2035 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
2036 	unsigned long	journal_devnum;
2037 	unsigned long	s_commit_interval;
2038 	unsigned long	s_stripe;
2039 	unsigned int	s_inode_readahead_blks;
2040 	unsigned int	s_want_extra_isize;
2041 	unsigned int	s_li_wait_mult;
2042 	unsigned int	s_max_dir_size_kb;
2043 	unsigned int	journal_ioprio;
2044 	unsigned int	vals_s_mount_opt;
2045 	unsigned int	mask_s_mount_opt;
2046 	unsigned int	vals_s_mount_opt2;
2047 	unsigned int	mask_s_mount_opt2;
2048 	unsigned long	vals_s_mount_flags;
2049 	unsigned long	mask_s_mount_flags;
2050 	unsigned int	opt_flags;	/* MOPT flags */
2051 	unsigned int	spec;
2052 	u32		s_max_batch_time;
2053 	u32		s_min_batch_time;
2054 	kuid_t		s_resuid;
2055 	kgid_t		s_resgid;
2056 	ext4_fsblk_t	s_sb_block;
2057 };
2058 
2059 static void ext4_fc_free(struct fs_context *fc)
2060 {
2061 	struct ext4_fs_context *ctx = fc->fs_private;
2062 	int i;
2063 
2064 	if (!ctx)
2065 		return;
2066 
2067 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2068 		kfree(ctx->s_qf_names[i]);
2069 
2070 	kfree(ctx->test_dummy_enc_arg);
2071 	kfree(ctx);
2072 }
2073 
2074 int ext4_init_fs_context(struct fs_context *fc)
2075 {
2076 	struct ext4_fs_context *ctx;
2077 
2078 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2079 	if (!ctx)
2080 		return -ENOMEM;
2081 
2082 	fc->fs_private = ctx;
2083 	fc->ops = &ext4_context_ops;
2084 
2085 	return 0;
2086 }
2087 
2088 #ifdef CONFIG_QUOTA
2089 /*
2090  * Note the name of the specified quota file.
2091  */
2092 static int note_qf_name(struct fs_context *fc, int qtype,
2093 		       struct fs_parameter *param)
2094 {
2095 	struct ext4_fs_context *ctx = fc->fs_private;
2096 	char *qname;
2097 
2098 	if (param->size < 1) {
2099 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2100 		return -EINVAL;
2101 	}
2102 	if (strchr(param->string, '/')) {
2103 		ext4_msg(NULL, KERN_ERR,
2104 			 "quotafile must be on filesystem root");
2105 		return -EINVAL;
2106 	}
2107 	if (ctx->s_qf_names[qtype]) {
2108 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2109 			ext4_msg(NULL, KERN_ERR,
2110 				 "%s quota file already specified",
2111 				 QTYPE2NAME(qtype));
2112 			return -EINVAL;
2113 		}
2114 		return 0;
2115 	}
2116 
2117 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2118 	if (!qname) {
2119 		ext4_msg(NULL, KERN_ERR,
2120 			 "Not enough memory for storing quotafile name");
2121 		return -ENOMEM;
2122 	}
2123 	ctx->s_qf_names[qtype] = qname;
2124 	ctx->qname_spec |= 1 << qtype;
2125 	ctx->spec |= EXT4_SPEC_JQUOTA;
2126 	return 0;
2127 }
2128 
2129 /*
2130  * Clear the name of the specified quota file.
2131  */
2132 static int unnote_qf_name(struct fs_context *fc, int qtype)
2133 {
2134 	struct ext4_fs_context *ctx = fc->fs_private;
2135 
2136 	if (ctx->s_qf_names[qtype])
2137 		kfree(ctx->s_qf_names[qtype]);
2138 
2139 	ctx->s_qf_names[qtype] = NULL;
2140 	ctx->qname_spec |= 1 << qtype;
2141 	ctx->spec |= EXT4_SPEC_JQUOTA;
2142 	return 0;
2143 }
2144 #endif
2145 
2146 #define EXT4_SET_CTX(name)						\
2147 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2148 				  unsigned long flag)			\
2149 {									\
2150 	ctx->mask_s_##name |= flag;					\
2151 	ctx->vals_s_##name |= flag;					\
2152 }
2153 
2154 #define EXT4_CLEAR_CTX(name)						\
2155 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2156 				    unsigned long flag)			\
2157 {									\
2158 	ctx->mask_s_##name |= flag;					\
2159 	ctx->vals_s_##name &= ~flag;					\
2160 }
2161 
2162 #define EXT4_TEST_CTX(name)						\
2163 static inline unsigned long						\
2164 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2165 {									\
2166 	return (ctx->vals_s_##name & flag);				\
2167 }
2168 
2169 EXT4_SET_CTX(flags); /* set only */
2170 EXT4_SET_CTX(mount_opt);
2171 EXT4_CLEAR_CTX(mount_opt);
2172 EXT4_TEST_CTX(mount_opt);
2173 EXT4_SET_CTX(mount_opt2);
2174 EXT4_CLEAR_CTX(mount_opt2);
2175 EXT4_TEST_CTX(mount_opt2);
2176 
2177 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2178 {
2179 	set_bit(bit, &ctx->mask_s_mount_flags);
2180 	set_bit(bit, &ctx->vals_s_mount_flags);
2181 }
2182 
2183 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2184 {
2185 	struct ext4_fs_context *ctx = fc->fs_private;
2186 	struct fs_parse_result result;
2187 	const struct mount_opts *m;
2188 	int is_remount;
2189 	kuid_t uid;
2190 	kgid_t gid;
2191 	int token;
2192 
2193 	token = fs_parse(fc, ext4_param_specs, param, &result);
2194 	if (token < 0)
2195 		return token;
2196 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2197 
2198 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2199 		if (token == m->token)
2200 			break;
2201 
2202 	ctx->opt_flags |= m->flags;
2203 
2204 	if (m->flags & MOPT_EXPLICIT) {
2205 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2206 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2207 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2208 			ctx_set_mount_opt2(ctx,
2209 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2210 		} else
2211 			return -EINVAL;
2212 	}
2213 
2214 	if (m->flags & MOPT_NOSUPPORT) {
2215 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2216 			 param->key);
2217 		return 0;
2218 	}
2219 
2220 	switch (token) {
2221 #ifdef CONFIG_QUOTA
2222 	case Opt_usrjquota:
2223 		if (!*param->string)
2224 			return unnote_qf_name(fc, USRQUOTA);
2225 		else
2226 			return note_qf_name(fc, USRQUOTA, param);
2227 	case Opt_grpjquota:
2228 		if (!*param->string)
2229 			return unnote_qf_name(fc, GRPQUOTA);
2230 		else
2231 			return note_qf_name(fc, GRPQUOTA, param);
2232 #endif
2233 	case Opt_noacl:
2234 	case Opt_nouser_xattr:
2235 		ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "3.5");
2236 		break;
2237 	case Opt_sb:
2238 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2239 			ext4_msg(NULL, KERN_WARNING,
2240 				 "Ignoring %s option on remount", param->key);
2241 		} else {
2242 			ctx->s_sb_block = result.uint_32;
2243 			ctx->spec |= EXT4_SPEC_s_sb_block;
2244 		}
2245 		return 0;
2246 	case Opt_removed:
2247 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2248 			 param->key);
2249 		return 0;
2250 	case Opt_abort:
2251 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2252 		return 0;
2253 	case Opt_i_version:
2254 		ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "5.20");
2255 		ext4_msg(NULL, KERN_WARNING, "Use iversion instead\n");
2256 		ctx_set_flags(ctx, SB_I_VERSION);
2257 		return 0;
2258 	case Opt_inlinecrypt:
2259 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2260 		ctx_set_flags(ctx, SB_INLINECRYPT);
2261 #else
2262 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2263 #endif
2264 		return 0;
2265 	case Opt_errors:
2266 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2267 		ctx_set_mount_opt(ctx, result.uint_32);
2268 		return 0;
2269 #ifdef CONFIG_QUOTA
2270 	case Opt_jqfmt:
2271 		ctx->s_jquota_fmt = result.uint_32;
2272 		ctx->spec |= EXT4_SPEC_JQFMT;
2273 		return 0;
2274 #endif
2275 	case Opt_data:
2276 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2277 		ctx_set_mount_opt(ctx, result.uint_32);
2278 		ctx->spec |= EXT4_SPEC_DATAJ;
2279 		return 0;
2280 	case Opt_commit:
2281 		if (result.uint_32 == 0)
2282 			ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2283 		else if (result.uint_32 > INT_MAX / HZ) {
2284 			ext4_msg(NULL, KERN_ERR,
2285 				 "Invalid commit interval %d, "
2286 				 "must be smaller than %d",
2287 				 result.uint_32, INT_MAX / HZ);
2288 			return -EINVAL;
2289 		}
2290 		ctx->s_commit_interval = HZ * result.uint_32;
2291 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2292 		return 0;
2293 	case Opt_debug_want_extra_isize:
2294 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2295 			ext4_msg(NULL, KERN_ERR,
2296 				 "Invalid want_extra_isize %d", result.uint_32);
2297 			return -EINVAL;
2298 		}
2299 		ctx->s_want_extra_isize = result.uint_32;
2300 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2301 		return 0;
2302 	case Opt_max_batch_time:
2303 		ctx->s_max_batch_time = result.uint_32;
2304 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2305 		return 0;
2306 	case Opt_min_batch_time:
2307 		ctx->s_min_batch_time = result.uint_32;
2308 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2309 		return 0;
2310 	case Opt_inode_readahead_blks:
2311 		if (result.uint_32 &&
2312 		    (result.uint_32 > (1 << 30) ||
2313 		     !is_power_of_2(result.uint_32))) {
2314 			ext4_msg(NULL, KERN_ERR,
2315 				 "EXT4-fs: inode_readahead_blks must be "
2316 				 "0 or a power of 2 smaller than 2^31");
2317 			return -EINVAL;
2318 		}
2319 		ctx->s_inode_readahead_blks = result.uint_32;
2320 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2321 		return 0;
2322 	case Opt_init_itable:
2323 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2324 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2325 		if (param->type == fs_value_is_string)
2326 			ctx->s_li_wait_mult = result.uint_32;
2327 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2328 		return 0;
2329 	case Opt_max_dir_size_kb:
2330 		ctx->s_max_dir_size_kb = result.uint_32;
2331 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2332 		return 0;
2333 #ifdef CONFIG_EXT4_DEBUG
2334 	case Opt_fc_debug_max_replay:
2335 		ctx->s_fc_debug_max_replay = result.uint_32;
2336 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2337 		return 0;
2338 #endif
2339 	case Opt_stripe:
2340 		ctx->s_stripe = result.uint_32;
2341 		ctx->spec |= EXT4_SPEC_s_stripe;
2342 		return 0;
2343 	case Opt_resuid:
2344 		uid = make_kuid(current_user_ns(), result.uint_32);
2345 		if (!uid_valid(uid)) {
2346 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2347 				 result.uint_32);
2348 			return -EINVAL;
2349 		}
2350 		ctx->s_resuid = uid;
2351 		ctx->spec |= EXT4_SPEC_s_resuid;
2352 		return 0;
2353 	case Opt_resgid:
2354 		gid = make_kgid(current_user_ns(), result.uint_32);
2355 		if (!gid_valid(gid)) {
2356 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2357 				 result.uint_32);
2358 			return -EINVAL;
2359 		}
2360 		ctx->s_resgid = gid;
2361 		ctx->spec |= EXT4_SPEC_s_resgid;
2362 		return 0;
2363 	case Opt_journal_dev:
2364 		if (is_remount) {
2365 			ext4_msg(NULL, KERN_ERR,
2366 				 "Cannot specify journal on remount");
2367 			return -EINVAL;
2368 		}
2369 		ctx->journal_devnum = result.uint_32;
2370 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2371 		return 0;
2372 	case Opt_journal_path:
2373 	{
2374 		struct inode *journal_inode;
2375 		struct path path;
2376 		int error;
2377 
2378 		if (is_remount) {
2379 			ext4_msg(NULL, KERN_ERR,
2380 				 "Cannot specify journal on remount");
2381 			return -EINVAL;
2382 		}
2383 
2384 		error = fs_lookup_param(fc, param, 1, &path);
2385 		if (error) {
2386 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2387 				 "journal device path");
2388 			return -EINVAL;
2389 		}
2390 
2391 		journal_inode = d_inode(path.dentry);
2392 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2393 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2394 		path_put(&path);
2395 		return 0;
2396 	}
2397 	case Opt_journal_ioprio:
2398 		if (result.uint_32 > 7) {
2399 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2400 				 " (must be 0-7)");
2401 			return -EINVAL;
2402 		}
2403 		ctx->journal_ioprio =
2404 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2405 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2406 		return 0;
2407 	case Opt_test_dummy_encryption:
2408 #ifdef CONFIG_FS_ENCRYPTION
2409 		if (param->type == fs_value_is_flag) {
2410 			ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
2411 			ctx->test_dummy_enc_arg = NULL;
2412 			return 0;
2413 		}
2414 		if (*param->string &&
2415 		    !(!strcmp(param->string, "v1") ||
2416 		      !strcmp(param->string, "v2"))) {
2417 			ext4_msg(NULL, KERN_WARNING,
2418 				 "Value of option \"%s\" is unrecognized",
2419 				 param->key);
2420 			return -EINVAL;
2421 		}
2422 		ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
2423 		ctx->test_dummy_enc_arg = kmemdup_nul(param->string, param->size,
2424 						      GFP_KERNEL);
2425 #else
2426 		ext4_msg(NULL, KERN_WARNING,
2427 			 "Test dummy encryption mount option ignored");
2428 #endif
2429 		return 0;
2430 	case Opt_dax:
2431 	case Opt_dax_type:
2432 #ifdef CONFIG_FS_DAX
2433 	{
2434 		int type = (token == Opt_dax) ?
2435 			   Opt_dax : result.uint_32;
2436 
2437 		switch (type) {
2438 		case Opt_dax:
2439 		case Opt_dax_always:
2440 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2441 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2442 			break;
2443 		case Opt_dax_never:
2444 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2445 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2446 			break;
2447 		case Opt_dax_inode:
2448 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2449 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2450 			/* Strictly for printing options */
2451 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2452 			break;
2453 		}
2454 		return 0;
2455 	}
2456 #else
2457 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2458 		return -EINVAL;
2459 #endif
2460 	case Opt_data_err:
2461 		if (result.uint_32 == Opt_data_err_abort)
2462 			ctx_set_mount_opt(ctx, m->mount_opt);
2463 		else if (result.uint_32 == Opt_data_err_ignore)
2464 			ctx_clear_mount_opt(ctx, m->mount_opt);
2465 		return 0;
2466 	case Opt_mb_optimize_scan:
2467 		if (result.int_32 == 1) {
2468 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2469 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2470 		} else if (result.int_32 == 0) {
2471 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2472 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2473 		} else {
2474 			ext4_msg(NULL, KERN_WARNING,
2475 				 "mb_optimize_scan should be set to 0 or 1.");
2476 			return -EINVAL;
2477 		}
2478 		return 0;
2479 	}
2480 
2481 	/*
2482 	 * At this point we should only be getting options requiring MOPT_SET,
2483 	 * or MOPT_CLEAR. Anything else is a bug
2484 	 */
2485 	if (m->token == Opt_err) {
2486 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2487 			 param->key);
2488 		WARN_ON(1);
2489 		return -EINVAL;
2490 	}
2491 
2492 	else {
2493 		unsigned int set = 0;
2494 
2495 		if ((param->type == fs_value_is_flag) ||
2496 		    result.uint_32 > 0)
2497 			set = 1;
2498 
2499 		if (m->flags & MOPT_CLEAR)
2500 			set = !set;
2501 		else if (unlikely(!(m->flags & MOPT_SET))) {
2502 			ext4_msg(NULL, KERN_WARNING,
2503 				 "buggy handling of option %s",
2504 				 param->key);
2505 			WARN_ON(1);
2506 			return -EINVAL;
2507 		}
2508 		if (m->flags & MOPT_2) {
2509 			if (set != 0)
2510 				ctx_set_mount_opt2(ctx, m->mount_opt);
2511 			else
2512 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2513 		} else {
2514 			if (set != 0)
2515 				ctx_set_mount_opt(ctx, m->mount_opt);
2516 			else
2517 				ctx_clear_mount_opt(ctx, m->mount_opt);
2518 		}
2519 	}
2520 
2521 	return 0;
2522 }
2523 
2524 static int parse_options(struct fs_context *fc, char *options)
2525 {
2526 	struct fs_parameter param;
2527 	int ret;
2528 	char *key;
2529 
2530 	if (!options)
2531 		return 0;
2532 
2533 	while ((key = strsep(&options, ",")) != NULL) {
2534 		if (*key) {
2535 			size_t v_len = 0;
2536 			char *value = strchr(key, '=');
2537 
2538 			param.type = fs_value_is_flag;
2539 			param.string = NULL;
2540 
2541 			if (value) {
2542 				if (value == key)
2543 					continue;
2544 
2545 				*value++ = 0;
2546 				v_len = strlen(value);
2547 				param.string = kmemdup_nul(value, v_len,
2548 							   GFP_KERNEL);
2549 				if (!param.string)
2550 					return -ENOMEM;
2551 				param.type = fs_value_is_string;
2552 			}
2553 
2554 			param.key = key;
2555 			param.size = v_len;
2556 
2557 			ret = ext4_parse_param(fc, &param);
2558 			if (param.string)
2559 				kfree(param.string);
2560 			if (ret < 0)
2561 				return ret;
2562 		}
2563 	}
2564 
2565 	ret = ext4_validate_options(fc);
2566 	if (ret < 0)
2567 		return ret;
2568 
2569 	return 0;
2570 }
2571 
2572 static int parse_apply_sb_mount_options(struct super_block *sb,
2573 					struct ext4_fs_context *m_ctx)
2574 {
2575 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2576 	char *s_mount_opts = NULL;
2577 	struct ext4_fs_context *s_ctx = NULL;
2578 	struct fs_context *fc = NULL;
2579 	int ret = -ENOMEM;
2580 
2581 	if (!sbi->s_es->s_mount_opts[0])
2582 		return 0;
2583 
2584 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2585 				sizeof(sbi->s_es->s_mount_opts),
2586 				GFP_KERNEL);
2587 	if (!s_mount_opts)
2588 		return ret;
2589 
2590 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2591 	if (!fc)
2592 		goto out_free;
2593 
2594 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2595 	if (!s_ctx)
2596 		goto out_free;
2597 
2598 	fc->fs_private = s_ctx;
2599 	fc->s_fs_info = sbi;
2600 
2601 	ret = parse_options(fc, s_mount_opts);
2602 	if (ret < 0)
2603 		goto parse_failed;
2604 
2605 	ret = ext4_check_opt_consistency(fc, sb);
2606 	if (ret < 0) {
2607 parse_failed:
2608 		ext4_msg(sb, KERN_WARNING,
2609 			 "failed to parse options in superblock: %s",
2610 			 s_mount_opts);
2611 		ret = 0;
2612 		goto out_free;
2613 	}
2614 
2615 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2616 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2617 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2618 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2619 
2620 	ret = ext4_apply_options(fc, sb);
2621 
2622 out_free:
2623 	kfree(s_ctx);
2624 	kfree(fc);
2625 	kfree(s_mount_opts);
2626 	return ret;
2627 }
2628 
2629 static void ext4_apply_quota_options(struct fs_context *fc,
2630 				     struct super_block *sb)
2631 {
2632 #ifdef CONFIG_QUOTA
2633 	bool quota_feature = ext4_has_feature_quota(sb);
2634 	struct ext4_fs_context *ctx = fc->fs_private;
2635 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2636 	char *qname;
2637 	int i;
2638 
2639 	if (quota_feature)
2640 		return;
2641 
2642 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2643 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2644 			if (!(ctx->qname_spec & (1 << i)))
2645 				continue;
2646 
2647 			qname = ctx->s_qf_names[i]; /* May be NULL */
2648 			if (qname)
2649 				set_opt(sb, QUOTA);
2650 			ctx->s_qf_names[i] = NULL;
2651 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2652 						lockdep_is_held(&sb->s_umount));
2653 			if (qname)
2654 				kfree_rcu(qname);
2655 		}
2656 	}
2657 
2658 	if (ctx->spec & EXT4_SPEC_JQFMT)
2659 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2660 #endif
2661 }
2662 
2663 /*
2664  * Check quota settings consistency.
2665  */
2666 static int ext4_check_quota_consistency(struct fs_context *fc,
2667 					struct super_block *sb)
2668 {
2669 #ifdef CONFIG_QUOTA
2670 	struct ext4_fs_context *ctx = fc->fs_private;
2671 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2672 	bool quota_feature = ext4_has_feature_quota(sb);
2673 	bool quota_loaded = sb_any_quota_loaded(sb);
2674 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2675 	int quota_flags, i;
2676 
2677 	/*
2678 	 * We do the test below only for project quotas. 'usrquota' and
2679 	 * 'grpquota' mount options are allowed even without quota feature
2680 	 * to support legacy quotas in quota files.
2681 	 */
2682 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2683 	    !ext4_has_feature_project(sb)) {
2684 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2685 			 "Cannot enable project quota enforcement.");
2686 		return -EINVAL;
2687 	}
2688 
2689 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2690 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2691 	if (quota_loaded &&
2692 	    ctx->mask_s_mount_opt & quota_flags &&
2693 	    !ctx_test_mount_opt(ctx, quota_flags))
2694 		goto err_quota_change;
2695 
2696 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2697 
2698 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2699 			if (!(ctx->qname_spec & (1 << i)))
2700 				continue;
2701 
2702 			if (quota_loaded &&
2703 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2704 				goto err_jquota_change;
2705 
2706 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2707 			    strcmp(get_qf_name(sb, sbi, i),
2708 				   ctx->s_qf_names[i]) != 0)
2709 				goto err_jquota_specified;
2710 		}
2711 
2712 		if (quota_feature) {
2713 			ext4_msg(NULL, KERN_INFO,
2714 				 "Journaled quota options ignored when "
2715 				 "QUOTA feature is enabled");
2716 			return 0;
2717 		}
2718 	}
2719 
2720 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2721 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2722 			goto err_jquota_change;
2723 		if (quota_feature) {
2724 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2725 				 "ignored when QUOTA feature is enabled");
2726 			return 0;
2727 		}
2728 	}
2729 
2730 	/* Make sure we don't mix old and new quota format */
2731 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2732 		       ctx->s_qf_names[USRQUOTA]);
2733 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2734 		       ctx->s_qf_names[GRPQUOTA]);
2735 
2736 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2737 		    test_opt(sb, USRQUOTA));
2738 
2739 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2740 		    test_opt(sb, GRPQUOTA));
2741 
2742 	if (usr_qf_name) {
2743 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2744 		usrquota = false;
2745 	}
2746 	if (grp_qf_name) {
2747 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2748 		grpquota = false;
2749 	}
2750 
2751 	if (usr_qf_name || grp_qf_name) {
2752 		if (usrquota || grpquota) {
2753 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2754 				 "format mixing");
2755 			return -EINVAL;
2756 		}
2757 
2758 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2759 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2760 				 "not specified");
2761 			return -EINVAL;
2762 		}
2763 	}
2764 
2765 	return 0;
2766 
2767 err_quota_change:
2768 	ext4_msg(NULL, KERN_ERR,
2769 		 "Cannot change quota options when quota turned on");
2770 	return -EINVAL;
2771 err_jquota_change:
2772 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2773 		 "options when quota turned on");
2774 	return -EINVAL;
2775 err_jquota_specified:
2776 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2777 		 QTYPE2NAME(i));
2778 	return -EINVAL;
2779 #else
2780 	return 0;
2781 #endif
2782 }
2783 
2784 static int ext4_check_opt_consistency(struct fs_context *fc,
2785 				      struct super_block *sb)
2786 {
2787 	struct ext4_fs_context *ctx = fc->fs_private;
2788 	struct ext4_sb_info *sbi = fc->s_fs_info;
2789 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2790 
2791 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2792 		ext4_msg(NULL, KERN_ERR,
2793 			 "Mount option(s) incompatible with ext2");
2794 		return -EINVAL;
2795 	}
2796 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2797 		ext4_msg(NULL, KERN_ERR,
2798 			 "Mount option(s) incompatible with ext3");
2799 		return -EINVAL;
2800 	}
2801 
2802 	if (ctx->s_want_extra_isize >
2803 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2804 		ext4_msg(NULL, KERN_ERR,
2805 			 "Invalid want_extra_isize %d",
2806 			 ctx->s_want_extra_isize);
2807 		return -EINVAL;
2808 	}
2809 
2810 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2811 		int blocksize =
2812 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2813 		if (blocksize < PAGE_SIZE)
2814 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2815 				 "experimental mount option 'dioread_nolock' "
2816 				 "for blocksize < PAGE_SIZE");
2817 	}
2818 
2819 #ifdef CONFIG_FS_ENCRYPTION
2820 	/*
2821 	 * This mount option is just for testing, and it's not worthwhile to
2822 	 * implement the extra complexity (e.g. RCU protection) that would be
2823 	 * needed to allow it to be set or changed during remount.  We do allow
2824 	 * it to be specified during remount, but only if there is no change.
2825 	 */
2826 	if ((ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION) &&
2827 	    is_remount && !sbi->s_dummy_enc_policy.policy) {
2828 		ext4_msg(NULL, KERN_WARNING,
2829 			 "Can't set test_dummy_encryption on remount");
2830 		return -1;
2831 	}
2832 #endif
2833 
2834 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2835 		if (!sbi->s_journal) {
2836 			ext4_msg(NULL, KERN_WARNING,
2837 				 "Remounting file system with no journal "
2838 				 "so ignoring journalled data option");
2839 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2840 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2841 			   test_opt(sb, DATA_FLAGS)) {
2842 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2843 				 "on remount");
2844 			return -EINVAL;
2845 		}
2846 	}
2847 
2848 	if (is_remount) {
2849 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2850 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2851 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2852 				 "both data=journal and dax");
2853 			return -EINVAL;
2854 		}
2855 
2856 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2857 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2858 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2859 fail_dax_change_remount:
2860 			ext4_msg(NULL, KERN_ERR, "can't change "
2861 				 "dax mount option while remounting");
2862 			return -EINVAL;
2863 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2864 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2865 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2866 			goto fail_dax_change_remount;
2867 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2868 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2869 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2870 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2871 			goto fail_dax_change_remount;
2872 		}
2873 	}
2874 
2875 	return ext4_check_quota_consistency(fc, sb);
2876 }
2877 
2878 static int ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2879 {
2880 	struct ext4_fs_context *ctx = fc->fs_private;
2881 	struct ext4_sb_info *sbi = fc->s_fs_info;
2882 	int ret = 0;
2883 
2884 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2885 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2886 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2887 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2888 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2889 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2890 	sb->s_flags &= ~ctx->mask_s_flags;
2891 	sb->s_flags |= ctx->vals_s_flags;
2892 
2893 	/*
2894 	 * i_version differs from common mount option iversion so we have
2895 	 * to let vfs know that it was set, otherwise it would get cleared
2896 	 * on remount
2897 	 */
2898 	if (ctx->mask_s_flags & SB_I_VERSION)
2899 		fc->sb_flags |= SB_I_VERSION;
2900 
2901 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2902 	APPLY(s_commit_interval);
2903 	APPLY(s_stripe);
2904 	APPLY(s_max_batch_time);
2905 	APPLY(s_min_batch_time);
2906 	APPLY(s_want_extra_isize);
2907 	APPLY(s_inode_readahead_blks);
2908 	APPLY(s_max_dir_size_kb);
2909 	APPLY(s_li_wait_mult);
2910 	APPLY(s_resgid);
2911 	APPLY(s_resuid);
2912 
2913 #ifdef CONFIG_EXT4_DEBUG
2914 	APPLY(s_fc_debug_max_replay);
2915 #endif
2916 
2917 	ext4_apply_quota_options(fc, sb);
2918 
2919 	if (ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION)
2920 		ret = ext4_set_test_dummy_encryption(sb, ctx->test_dummy_enc_arg);
2921 
2922 	return ret;
2923 }
2924 
2925 
2926 static int ext4_validate_options(struct fs_context *fc)
2927 {
2928 #ifdef CONFIG_QUOTA
2929 	struct ext4_fs_context *ctx = fc->fs_private;
2930 	char *usr_qf_name, *grp_qf_name;
2931 
2932 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2933 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2934 
2935 	if (usr_qf_name || grp_qf_name) {
2936 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2937 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2938 
2939 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2940 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2941 
2942 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2943 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2944 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2945 				 "format mixing");
2946 			return -EINVAL;
2947 		}
2948 	}
2949 #endif
2950 	return 1;
2951 }
2952 
2953 static inline void ext4_show_quota_options(struct seq_file *seq,
2954 					   struct super_block *sb)
2955 {
2956 #if defined(CONFIG_QUOTA)
2957 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2958 	char *usr_qf_name, *grp_qf_name;
2959 
2960 	if (sbi->s_jquota_fmt) {
2961 		char *fmtname = "";
2962 
2963 		switch (sbi->s_jquota_fmt) {
2964 		case QFMT_VFS_OLD:
2965 			fmtname = "vfsold";
2966 			break;
2967 		case QFMT_VFS_V0:
2968 			fmtname = "vfsv0";
2969 			break;
2970 		case QFMT_VFS_V1:
2971 			fmtname = "vfsv1";
2972 			break;
2973 		}
2974 		seq_printf(seq, ",jqfmt=%s", fmtname);
2975 	}
2976 
2977 	rcu_read_lock();
2978 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2979 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2980 	if (usr_qf_name)
2981 		seq_show_option(seq, "usrjquota", usr_qf_name);
2982 	if (grp_qf_name)
2983 		seq_show_option(seq, "grpjquota", grp_qf_name);
2984 	rcu_read_unlock();
2985 #endif
2986 }
2987 
2988 static const char *token2str(int token)
2989 {
2990 	const struct fs_parameter_spec *spec;
2991 
2992 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2993 		if (spec->opt == token && !spec->type)
2994 			break;
2995 	return spec->name;
2996 }
2997 
2998 /*
2999  * Show an option if
3000  *  - it's set to a non-default value OR
3001  *  - if the per-sb default is different from the global default
3002  */
3003 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
3004 			      int nodefs)
3005 {
3006 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3007 	struct ext4_super_block *es = sbi->s_es;
3008 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
3009 	const struct mount_opts *m;
3010 	char sep = nodefs ? '\n' : ',';
3011 
3012 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
3013 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
3014 
3015 	if (sbi->s_sb_block != 1)
3016 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
3017 
3018 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
3019 		int want_set = m->flags & MOPT_SET;
3020 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
3021 		    m->flags & MOPT_SKIP)
3022 			continue;
3023 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
3024 			continue; /* skip if same as the default */
3025 		if ((want_set &&
3026 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
3027 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
3028 			continue; /* select Opt_noFoo vs Opt_Foo */
3029 		SEQ_OPTS_PRINT("%s", token2str(m->token));
3030 	}
3031 
3032 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
3033 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
3034 		SEQ_OPTS_PRINT("resuid=%u",
3035 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
3036 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
3037 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
3038 		SEQ_OPTS_PRINT("resgid=%u",
3039 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
3040 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
3041 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3042 		SEQ_OPTS_PUTS("errors=remount-ro");
3043 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3044 		SEQ_OPTS_PUTS("errors=continue");
3045 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3046 		SEQ_OPTS_PUTS("errors=panic");
3047 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3048 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3049 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3050 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3051 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3052 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3053 	if (sb->s_flags & SB_I_VERSION)
3054 		SEQ_OPTS_PUTS("i_version");
3055 	if (nodefs || sbi->s_stripe)
3056 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3057 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3058 			(sbi->s_mount_opt ^ def_mount_opt)) {
3059 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3060 			SEQ_OPTS_PUTS("data=journal");
3061 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3062 			SEQ_OPTS_PUTS("data=ordered");
3063 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3064 			SEQ_OPTS_PUTS("data=writeback");
3065 	}
3066 	if (nodefs ||
3067 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3068 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3069 			       sbi->s_inode_readahead_blks);
3070 
3071 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3072 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3073 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3074 	if (nodefs || sbi->s_max_dir_size_kb)
3075 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3076 	if (test_opt(sb, DATA_ERR_ABORT))
3077 		SEQ_OPTS_PUTS("data_err=abort");
3078 
3079 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3080 
3081 	if (sb->s_flags & SB_INLINECRYPT)
3082 		SEQ_OPTS_PUTS("inlinecrypt");
3083 
3084 	if (test_opt(sb, DAX_ALWAYS)) {
3085 		if (IS_EXT2_SB(sb))
3086 			SEQ_OPTS_PUTS("dax");
3087 		else
3088 			SEQ_OPTS_PUTS("dax=always");
3089 	} else if (test_opt2(sb, DAX_NEVER)) {
3090 		SEQ_OPTS_PUTS("dax=never");
3091 	} else if (test_opt2(sb, DAX_INODE)) {
3092 		SEQ_OPTS_PUTS("dax=inode");
3093 	}
3094 	ext4_show_quota_options(seq, sb);
3095 	return 0;
3096 }
3097 
3098 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3099 {
3100 	return _ext4_show_options(seq, root->d_sb, 0);
3101 }
3102 
3103 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3104 {
3105 	struct super_block *sb = seq->private;
3106 	int rc;
3107 
3108 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3109 	rc = _ext4_show_options(seq, sb, 1);
3110 	seq_puts(seq, "\n");
3111 	return rc;
3112 }
3113 
3114 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3115 			    int read_only)
3116 {
3117 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3118 	int err = 0;
3119 
3120 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3121 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3122 			 "forcing read-only mode");
3123 		err = -EROFS;
3124 		goto done;
3125 	}
3126 	if (read_only)
3127 		goto done;
3128 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3129 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3130 			 "running e2fsck is recommended");
3131 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3132 		ext4_msg(sb, KERN_WARNING,
3133 			 "warning: mounting fs with errors, "
3134 			 "running e2fsck is recommended");
3135 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3136 		 le16_to_cpu(es->s_mnt_count) >=
3137 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3138 		ext4_msg(sb, KERN_WARNING,
3139 			 "warning: maximal mount count reached, "
3140 			 "running e2fsck is recommended");
3141 	else if (le32_to_cpu(es->s_checkinterval) &&
3142 		 (ext4_get_tstamp(es, s_lastcheck) +
3143 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3144 		ext4_msg(sb, KERN_WARNING,
3145 			 "warning: checktime reached, "
3146 			 "running e2fsck is recommended");
3147 	if (!sbi->s_journal)
3148 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3149 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3150 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3151 	le16_add_cpu(&es->s_mnt_count, 1);
3152 	ext4_update_tstamp(es, s_mtime);
3153 	if (sbi->s_journal) {
3154 		ext4_set_feature_journal_needs_recovery(sb);
3155 		if (ext4_has_feature_orphan_file(sb))
3156 			ext4_set_feature_orphan_present(sb);
3157 	}
3158 
3159 	err = ext4_commit_super(sb);
3160 done:
3161 	if (test_opt(sb, DEBUG))
3162 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3163 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3164 			sb->s_blocksize,
3165 			sbi->s_groups_count,
3166 			EXT4_BLOCKS_PER_GROUP(sb),
3167 			EXT4_INODES_PER_GROUP(sb),
3168 			sbi->s_mount_opt, sbi->s_mount_opt2);
3169 	return err;
3170 }
3171 
3172 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3173 {
3174 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3175 	struct flex_groups **old_groups, **new_groups;
3176 	int size, i, j;
3177 
3178 	if (!sbi->s_log_groups_per_flex)
3179 		return 0;
3180 
3181 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3182 	if (size <= sbi->s_flex_groups_allocated)
3183 		return 0;
3184 
3185 	new_groups = kvzalloc(roundup_pow_of_two(size *
3186 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3187 	if (!new_groups) {
3188 		ext4_msg(sb, KERN_ERR,
3189 			 "not enough memory for %d flex group pointers", size);
3190 		return -ENOMEM;
3191 	}
3192 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3193 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3194 					 sizeof(struct flex_groups)),
3195 					 GFP_KERNEL);
3196 		if (!new_groups[i]) {
3197 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3198 				kvfree(new_groups[j]);
3199 			kvfree(new_groups);
3200 			ext4_msg(sb, KERN_ERR,
3201 				 "not enough memory for %d flex groups", size);
3202 			return -ENOMEM;
3203 		}
3204 	}
3205 	rcu_read_lock();
3206 	old_groups = rcu_dereference(sbi->s_flex_groups);
3207 	if (old_groups)
3208 		memcpy(new_groups, old_groups,
3209 		       (sbi->s_flex_groups_allocated *
3210 			sizeof(struct flex_groups *)));
3211 	rcu_read_unlock();
3212 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3213 	sbi->s_flex_groups_allocated = size;
3214 	if (old_groups)
3215 		ext4_kvfree_array_rcu(old_groups);
3216 	return 0;
3217 }
3218 
3219 static int ext4_fill_flex_info(struct super_block *sb)
3220 {
3221 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3222 	struct ext4_group_desc *gdp = NULL;
3223 	struct flex_groups *fg;
3224 	ext4_group_t flex_group;
3225 	int i, err;
3226 
3227 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3228 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3229 		sbi->s_log_groups_per_flex = 0;
3230 		return 1;
3231 	}
3232 
3233 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3234 	if (err)
3235 		goto failed;
3236 
3237 	for (i = 0; i < sbi->s_groups_count; i++) {
3238 		gdp = ext4_get_group_desc(sb, i, NULL);
3239 
3240 		flex_group = ext4_flex_group(sbi, i);
3241 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3242 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3243 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3244 			     &fg->free_clusters);
3245 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3246 	}
3247 
3248 	return 1;
3249 failed:
3250 	return 0;
3251 }
3252 
3253 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3254 				   struct ext4_group_desc *gdp)
3255 {
3256 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3257 	__u16 crc = 0;
3258 	__le32 le_group = cpu_to_le32(block_group);
3259 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3260 
3261 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3262 		/* Use new metadata_csum algorithm */
3263 		__u32 csum32;
3264 		__u16 dummy_csum = 0;
3265 
3266 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3267 				     sizeof(le_group));
3268 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3269 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3270 				     sizeof(dummy_csum));
3271 		offset += sizeof(dummy_csum);
3272 		if (offset < sbi->s_desc_size)
3273 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3274 					     sbi->s_desc_size - offset);
3275 
3276 		crc = csum32 & 0xFFFF;
3277 		goto out;
3278 	}
3279 
3280 	/* old crc16 code */
3281 	if (!ext4_has_feature_gdt_csum(sb))
3282 		return 0;
3283 
3284 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3285 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3286 	crc = crc16(crc, (__u8 *)gdp, offset);
3287 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3288 	/* for checksum of struct ext4_group_desc do the rest...*/
3289 	if (ext4_has_feature_64bit(sb) &&
3290 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3291 		crc = crc16(crc, (__u8 *)gdp + offset,
3292 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3293 				offset);
3294 
3295 out:
3296 	return cpu_to_le16(crc);
3297 }
3298 
3299 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3300 				struct ext4_group_desc *gdp)
3301 {
3302 	if (ext4_has_group_desc_csum(sb) &&
3303 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3304 		return 0;
3305 
3306 	return 1;
3307 }
3308 
3309 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3310 			      struct ext4_group_desc *gdp)
3311 {
3312 	if (!ext4_has_group_desc_csum(sb))
3313 		return;
3314 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3315 }
3316 
3317 /* Called at mount-time, super-block is locked */
3318 static int ext4_check_descriptors(struct super_block *sb,
3319 				  ext4_fsblk_t sb_block,
3320 				  ext4_group_t *first_not_zeroed)
3321 {
3322 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3323 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3324 	ext4_fsblk_t last_block;
3325 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3326 	ext4_fsblk_t block_bitmap;
3327 	ext4_fsblk_t inode_bitmap;
3328 	ext4_fsblk_t inode_table;
3329 	int flexbg_flag = 0;
3330 	ext4_group_t i, grp = sbi->s_groups_count;
3331 
3332 	if (ext4_has_feature_flex_bg(sb))
3333 		flexbg_flag = 1;
3334 
3335 	ext4_debug("Checking group descriptors");
3336 
3337 	for (i = 0; i < sbi->s_groups_count; i++) {
3338 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3339 
3340 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3341 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3342 		else
3343 			last_block = first_block +
3344 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3345 
3346 		if ((grp == sbi->s_groups_count) &&
3347 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3348 			grp = i;
3349 
3350 		block_bitmap = ext4_block_bitmap(sb, gdp);
3351 		if (block_bitmap == sb_block) {
3352 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3353 				 "Block bitmap for group %u overlaps "
3354 				 "superblock", i);
3355 			if (!sb_rdonly(sb))
3356 				return 0;
3357 		}
3358 		if (block_bitmap >= sb_block + 1 &&
3359 		    block_bitmap <= last_bg_block) {
3360 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3361 				 "Block bitmap for group %u overlaps "
3362 				 "block group descriptors", i);
3363 			if (!sb_rdonly(sb))
3364 				return 0;
3365 		}
3366 		if (block_bitmap < first_block || block_bitmap > last_block) {
3367 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3368 			       "Block bitmap for group %u not in group "
3369 			       "(block %llu)!", i, block_bitmap);
3370 			return 0;
3371 		}
3372 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3373 		if (inode_bitmap == sb_block) {
3374 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3375 				 "Inode bitmap for group %u overlaps "
3376 				 "superblock", i);
3377 			if (!sb_rdonly(sb))
3378 				return 0;
3379 		}
3380 		if (inode_bitmap >= sb_block + 1 &&
3381 		    inode_bitmap <= last_bg_block) {
3382 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3383 				 "Inode bitmap for group %u overlaps "
3384 				 "block group descriptors", i);
3385 			if (!sb_rdonly(sb))
3386 				return 0;
3387 		}
3388 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3389 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3390 			       "Inode bitmap for group %u not in group "
3391 			       "(block %llu)!", i, inode_bitmap);
3392 			return 0;
3393 		}
3394 		inode_table = ext4_inode_table(sb, gdp);
3395 		if (inode_table == sb_block) {
3396 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3397 				 "Inode table for group %u overlaps "
3398 				 "superblock", i);
3399 			if (!sb_rdonly(sb))
3400 				return 0;
3401 		}
3402 		if (inode_table >= sb_block + 1 &&
3403 		    inode_table <= last_bg_block) {
3404 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3405 				 "Inode table for group %u overlaps "
3406 				 "block group descriptors", i);
3407 			if (!sb_rdonly(sb))
3408 				return 0;
3409 		}
3410 		if (inode_table < first_block ||
3411 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3412 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3413 			       "Inode table for group %u not in group "
3414 			       "(block %llu)!", i, inode_table);
3415 			return 0;
3416 		}
3417 		ext4_lock_group(sb, i);
3418 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3419 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3420 				 "Checksum for group %u failed (%u!=%u)",
3421 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3422 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3423 			if (!sb_rdonly(sb)) {
3424 				ext4_unlock_group(sb, i);
3425 				return 0;
3426 			}
3427 		}
3428 		ext4_unlock_group(sb, i);
3429 		if (!flexbg_flag)
3430 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3431 	}
3432 	if (NULL != first_not_zeroed)
3433 		*first_not_zeroed = grp;
3434 	return 1;
3435 }
3436 
3437 /*
3438  * Maximal extent format file size.
3439  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3440  * extent format containers, within a sector_t, and within i_blocks
3441  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3442  * so that won't be a limiting factor.
3443  *
3444  * However there is other limiting factor. We do store extents in the form
3445  * of starting block and length, hence the resulting length of the extent
3446  * covering maximum file size must fit into on-disk format containers as
3447  * well. Given that length is always by 1 unit bigger than max unit (because
3448  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3449  *
3450  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3451  */
3452 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3453 {
3454 	loff_t res;
3455 	loff_t upper_limit = MAX_LFS_FILESIZE;
3456 
3457 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3458 
3459 	if (!has_huge_files) {
3460 		upper_limit = (1LL << 32) - 1;
3461 
3462 		/* total blocks in file system block size */
3463 		upper_limit >>= (blkbits - 9);
3464 		upper_limit <<= blkbits;
3465 	}
3466 
3467 	/*
3468 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3469 	 * by one fs block, so ee_len can cover the extent of maximum file
3470 	 * size
3471 	 */
3472 	res = (1LL << 32) - 1;
3473 	res <<= blkbits;
3474 
3475 	/* Sanity check against vm- & vfs- imposed limits */
3476 	if (res > upper_limit)
3477 		res = upper_limit;
3478 
3479 	return res;
3480 }
3481 
3482 /*
3483  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3484  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3485  * We need to be 1 filesystem block less than the 2^48 sector limit.
3486  */
3487 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3488 {
3489 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3490 	int meta_blocks;
3491 	unsigned int ppb = 1 << (bits - 2);
3492 
3493 	/*
3494 	 * This is calculated to be the largest file size for a dense, block
3495 	 * mapped file such that the file's total number of 512-byte sectors,
3496 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3497 	 *
3498 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3499 	 * number of 512-byte sectors of the file.
3500 	 */
3501 	if (!has_huge_files) {
3502 		/*
3503 		 * !has_huge_files or implies that the inode i_block field
3504 		 * represents total file blocks in 2^32 512-byte sectors ==
3505 		 * size of vfs inode i_blocks * 8
3506 		 */
3507 		upper_limit = (1LL << 32) - 1;
3508 
3509 		/* total blocks in file system block size */
3510 		upper_limit >>= (bits - 9);
3511 
3512 	} else {
3513 		/*
3514 		 * We use 48 bit ext4_inode i_blocks
3515 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3516 		 * represent total number of blocks in
3517 		 * file system block size
3518 		 */
3519 		upper_limit = (1LL << 48) - 1;
3520 
3521 	}
3522 
3523 	/* Compute how many blocks we can address by block tree */
3524 	res += ppb;
3525 	res += ppb * ppb;
3526 	res += ((loff_t)ppb) * ppb * ppb;
3527 	/* Compute how many metadata blocks are needed */
3528 	meta_blocks = 1;
3529 	meta_blocks += 1 + ppb;
3530 	meta_blocks += 1 + ppb + ppb * ppb;
3531 	/* Does block tree limit file size? */
3532 	if (res + meta_blocks <= upper_limit)
3533 		goto check_lfs;
3534 
3535 	res = upper_limit;
3536 	/* How many metadata blocks are needed for addressing upper_limit? */
3537 	upper_limit -= EXT4_NDIR_BLOCKS;
3538 	/* indirect blocks */
3539 	meta_blocks = 1;
3540 	upper_limit -= ppb;
3541 	/* double indirect blocks */
3542 	if (upper_limit < ppb * ppb) {
3543 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3544 		res -= meta_blocks;
3545 		goto check_lfs;
3546 	}
3547 	meta_blocks += 1 + ppb;
3548 	upper_limit -= ppb * ppb;
3549 	/* tripple indirect blocks for the rest */
3550 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3551 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3552 	res -= meta_blocks;
3553 check_lfs:
3554 	res <<= bits;
3555 	if (res > MAX_LFS_FILESIZE)
3556 		res = MAX_LFS_FILESIZE;
3557 
3558 	return res;
3559 }
3560 
3561 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3562 				   ext4_fsblk_t logical_sb_block, int nr)
3563 {
3564 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3565 	ext4_group_t bg, first_meta_bg;
3566 	int has_super = 0;
3567 
3568 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3569 
3570 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3571 		return logical_sb_block + nr + 1;
3572 	bg = sbi->s_desc_per_block * nr;
3573 	if (ext4_bg_has_super(sb, bg))
3574 		has_super = 1;
3575 
3576 	/*
3577 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3578 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3579 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3580 	 * compensate.
3581 	 */
3582 	if (sb->s_blocksize == 1024 && nr == 0 &&
3583 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3584 		has_super++;
3585 
3586 	return (has_super + ext4_group_first_block_no(sb, bg));
3587 }
3588 
3589 /**
3590  * ext4_get_stripe_size: Get the stripe size.
3591  * @sbi: In memory super block info
3592  *
3593  * If we have specified it via mount option, then
3594  * use the mount option value. If the value specified at mount time is
3595  * greater than the blocks per group use the super block value.
3596  * If the super block value is greater than blocks per group return 0.
3597  * Allocator needs it be less than blocks per group.
3598  *
3599  */
3600 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3601 {
3602 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3603 	unsigned long stripe_width =
3604 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3605 	int ret;
3606 
3607 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3608 		ret = sbi->s_stripe;
3609 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3610 		ret = stripe_width;
3611 	else if (stride && stride <= sbi->s_blocks_per_group)
3612 		ret = stride;
3613 	else
3614 		ret = 0;
3615 
3616 	/*
3617 	 * If the stripe width is 1, this makes no sense and
3618 	 * we set it to 0 to turn off stripe handling code.
3619 	 */
3620 	if (ret <= 1)
3621 		ret = 0;
3622 
3623 	return ret;
3624 }
3625 
3626 /*
3627  * Check whether this filesystem can be mounted based on
3628  * the features present and the RDONLY/RDWR mount requested.
3629  * Returns 1 if this filesystem can be mounted as requested,
3630  * 0 if it cannot be.
3631  */
3632 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3633 {
3634 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3635 		ext4_msg(sb, KERN_ERR,
3636 			"Couldn't mount because of "
3637 			"unsupported optional features (%x)",
3638 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3639 			~EXT4_FEATURE_INCOMPAT_SUPP));
3640 		return 0;
3641 	}
3642 
3643 #if !IS_ENABLED(CONFIG_UNICODE)
3644 	if (ext4_has_feature_casefold(sb)) {
3645 		ext4_msg(sb, KERN_ERR,
3646 			 "Filesystem with casefold feature cannot be "
3647 			 "mounted without CONFIG_UNICODE");
3648 		return 0;
3649 	}
3650 #endif
3651 
3652 	if (readonly)
3653 		return 1;
3654 
3655 	if (ext4_has_feature_readonly(sb)) {
3656 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3657 		sb->s_flags |= SB_RDONLY;
3658 		return 1;
3659 	}
3660 
3661 	/* Check that feature set is OK for a read-write mount */
3662 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3663 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3664 			 "unsupported optional features (%x)",
3665 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3666 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3667 		return 0;
3668 	}
3669 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3670 		ext4_msg(sb, KERN_ERR,
3671 			 "Can't support bigalloc feature without "
3672 			 "extents feature\n");
3673 		return 0;
3674 	}
3675 
3676 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3677 	if (!readonly && (ext4_has_feature_quota(sb) ||
3678 			  ext4_has_feature_project(sb))) {
3679 		ext4_msg(sb, KERN_ERR,
3680 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3681 		return 0;
3682 	}
3683 #endif  /* CONFIG_QUOTA */
3684 	return 1;
3685 }
3686 
3687 /*
3688  * This function is called once a day if we have errors logged
3689  * on the file system
3690  */
3691 static void print_daily_error_info(struct timer_list *t)
3692 {
3693 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3694 	struct super_block *sb = sbi->s_sb;
3695 	struct ext4_super_block *es = sbi->s_es;
3696 
3697 	if (es->s_error_count)
3698 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3699 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3700 			 le32_to_cpu(es->s_error_count));
3701 	if (es->s_first_error_time) {
3702 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3703 		       sb->s_id,
3704 		       ext4_get_tstamp(es, s_first_error_time),
3705 		       (int) sizeof(es->s_first_error_func),
3706 		       es->s_first_error_func,
3707 		       le32_to_cpu(es->s_first_error_line));
3708 		if (es->s_first_error_ino)
3709 			printk(KERN_CONT ": inode %u",
3710 			       le32_to_cpu(es->s_first_error_ino));
3711 		if (es->s_first_error_block)
3712 			printk(KERN_CONT ": block %llu", (unsigned long long)
3713 			       le64_to_cpu(es->s_first_error_block));
3714 		printk(KERN_CONT "\n");
3715 	}
3716 	if (es->s_last_error_time) {
3717 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3718 		       sb->s_id,
3719 		       ext4_get_tstamp(es, s_last_error_time),
3720 		       (int) sizeof(es->s_last_error_func),
3721 		       es->s_last_error_func,
3722 		       le32_to_cpu(es->s_last_error_line));
3723 		if (es->s_last_error_ino)
3724 			printk(KERN_CONT ": inode %u",
3725 			       le32_to_cpu(es->s_last_error_ino));
3726 		if (es->s_last_error_block)
3727 			printk(KERN_CONT ": block %llu", (unsigned long long)
3728 			       le64_to_cpu(es->s_last_error_block));
3729 		printk(KERN_CONT "\n");
3730 	}
3731 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3732 }
3733 
3734 /* Find next suitable group and run ext4_init_inode_table */
3735 static int ext4_run_li_request(struct ext4_li_request *elr)
3736 {
3737 	struct ext4_group_desc *gdp = NULL;
3738 	struct super_block *sb = elr->lr_super;
3739 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3740 	ext4_group_t group = elr->lr_next_group;
3741 	unsigned int prefetch_ios = 0;
3742 	int ret = 0;
3743 	u64 start_time;
3744 
3745 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3746 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3747 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3748 		if (prefetch_ios)
3749 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3750 					      prefetch_ios);
3751 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3752 					    prefetch_ios);
3753 		if (group >= elr->lr_next_group) {
3754 			ret = 1;
3755 			if (elr->lr_first_not_zeroed != ngroups &&
3756 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3757 				elr->lr_next_group = elr->lr_first_not_zeroed;
3758 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3759 				ret = 0;
3760 			}
3761 		}
3762 		return ret;
3763 	}
3764 
3765 	for (; group < ngroups; group++) {
3766 		gdp = ext4_get_group_desc(sb, group, NULL);
3767 		if (!gdp) {
3768 			ret = 1;
3769 			break;
3770 		}
3771 
3772 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3773 			break;
3774 	}
3775 
3776 	if (group >= ngroups)
3777 		ret = 1;
3778 
3779 	if (!ret) {
3780 		start_time = ktime_get_real_ns();
3781 		ret = ext4_init_inode_table(sb, group,
3782 					    elr->lr_timeout ? 0 : 1);
3783 		trace_ext4_lazy_itable_init(sb, group);
3784 		if (elr->lr_timeout == 0) {
3785 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3786 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3787 		}
3788 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3789 		elr->lr_next_group = group + 1;
3790 	}
3791 	return ret;
3792 }
3793 
3794 /*
3795  * Remove lr_request from the list_request and free the
3796  * request structure. Should be called with li_list_mtx held
3797  */
3798 static void ext4_remove_li_request(struct ext4_li_request *elr)
3799 {
3800 	if (!elr)
3801 		return;
3802 
3803 	list_del(&elr->lr_request);
3804 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3805 	kfree(elr);
3806 }
3807 
3808 static void ext4_unregister_li_request(struct super_block *sb)
3809 {
3810 	mutex_lock(&ext4_li_mtx);
3811 	if (!ext4_li_info) {
3812 		mutex_unlock(&ext4_li_mtx);
3813 		return;
3814 	}
3815 
3816 	mutex_lock(&ext4_li_info->li_list_mtx);
3817 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3818 	mutex_unlock(&ext4_li_info->li_list_mtx);
3819 	mutex_unlock(&ext4_li_mtx);
3820 }
3821 
3822 static struct task_struct *ext4_lazyinit_task;
3823 
3824 /*
3825  * This is the function where ext4lazyinit thread lives. It walks
3826  * through the request list searching for next scheduled filesystem.
3827  * When such a fs is found, run the lazy initialization request
3828  * (ext4_rn_li_request) and keep track of the time spend in this
3829  * function. Based on that time we compute next schedule time of
3830  * the request. When walking through the list is complete, compute
3831  * next waking time and put itself into sleep.
3832  */
3833 static int ext4_lazyinit_thread(void *arg)
3834 {
3835 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3836 	struct list_head *pos, *n;
3837 	struct ext4_li_request *elr;
3838 	unsigned long next_wakeup, cur;
3839 
3840 	BUG_ON(NULL == eli);
3841 
3842 cont_thread:
3843 	while (true) {
3844 		next_wakeup = MAX_JIFFY_OFFSET;
3845 
3846 		mutex_lock(&eli->li_list_mtx);
3847 		if (list_empty(&eli->li_request_list)) {
3848 			mutex_unlock(&eli->li_list_mtx);
3849 			goto exit_thread;
3850 		}
3851 		list_for_each_safe(pos, n, &eli->li_request_list) {
3852 			int err = 0;
3853 			int progress = 0;
3854 			elr = list_entry(pos, struct ext4_li_request,
3855 					 lr_request);
3856 
3857 			if (time_before(jiffies, elr->lr_next_sched)) {
3858 				if (time_before(elr->lr_next_sched, next_wakeup))
3859 					next_wakeup = elr->lr_next_sched;
3860 				continue;
3861 			}
3862 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3863 				if (sb_start_write_trylock(elr->lr_super)) {
3864 					progress = 1;
3865 					/*
3866 					 * We hold sb->s_umount, sb can not
3867 					 * be removed from the list, it is
3868 					 * now safe to drop li_list_mtx
3869 					 */
3870 					mutex_unlock(&eli->li_list_mtx);
3871 					err = ext4_run_li_request(elr);
3872 					sb_end_write(elr->lr_super);
3873 					mutex_lock(&eli->li_list_mtx);
3874 					n = pos->next;
3875 				}
3876 				up_read((&elr->lr_super->s_umount));
3877 			}
3878 			/* error, remove the lazy_init job */
3879 			if (err) {
3880 				ext4_remove_li_request(elr);
3881 				continue;
3882 			}
3883 			if (!progress) {
3884 				elr->lr_next_sched = jiffies +
3885 					(prandom_u32()
3886 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3887 			}
3888 			if (time_before(elr->lr_next_sched, next_wakeup))
3889 				next_wakeup = elr->lr_next_sched;
3890 		}
3891 		mutex_unlock(&eli->li_list_mtx);
3892 
3893 		try_to_freeze();
3894 
3895 		cur = jiffies;
3896 		if ((time_after_eq(cur, next_wakeup)) ||
3897 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3898 			cond_resched();
3899 			continue;
3900 		}
3901 
3902 		schedule_timeout_interruptible(next_wakeup - cur);
3903 
3904 		if (kthread_should_stop()) {
3905 			ext4_clear_request_list();
3906 			goto exit_thread;
3907 		}
3908 	}
3909 
3910 exit_thread:
3911 	/*
3912 	 * It looks like the request list is empty, but we need
3913 	 * to check it under the li_list_mtx lock, to prevent any
3914 	 * additions into it, and of course we should lock ext4_li_mtx
3915 	 * to atomically free the list and ext4_li_info, because at
3916 	 * this point another ext4 filesystem could be registering
3917 	 * new one.
3918 	 */
3919 	mutex_lock(&ext4_li_mtx);
3920 	mutex_lock(&eli->li_list_mtx);
3921 	if (!list_empty(&eli->li_request_list)) {
3922 		mutex_unlock(&eli->li_list_mtx);
3923 		mutex_unlock(&ext4_li_mtx);
3924 		goto cont_thread;
3925 	}
3926 	mutex_unlock(&eli->li_list_mtx);
3927 	kfree(ext4_li_info);
3928 	ext4_li_info = NULL;
3929 	mutex_unlock(&ext4_li_mtx);
3930 
3931 	return 0;
3932 }
3933 
3934 static void ext4_clear_request_list(void)
3935 {
3936 	struct list_head *pos, *n;
3937 	struct ext4_li_request *elr;
3938 
3939 	mutex_lock(&ext4_li_info->li_list_mtx);
3940 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3941 		elr = list_entry(pos, struct ext4_li_request,
3942 				 lr_request);
3943 		ext4_remove_li_request(elr);
3944 	}
3945 	mutex_unlock(&ext4_li_info->li_list_mtx);
3946 }
3947 
3948 static int ext4_run_lazyinit_thread(void)
3949 {
3950 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3951 					 ext4_li_info, "ext4lazyinit");
3952 	if (IS_ERR(ext4_lazyinit_task)) {
3953 		int err = PTR_ERR(ext4_lazyinit_task);
3954 		ext4_clear_request_list();
3955 		kfree(ext4_li_info);
3956 		ext4_li_info = NULL;
3957 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3958 				 "initialization thread\n",
3959 				 err);
3960 		return err;
3961 	}
3962 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3963 	return 0;
3964 }
3965 
3966 /*
3967  * Check whether it make sense to run itable init. thread or not.
3968  * If there is at least one uninitialized inode table, return
3969  * corresponding group number, else the loop goes through all
3970  * groups and return total number of groups.
3971  */
3972 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3973 {
3974 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3975 	struct ext4_group_desc *gdp = NULL;
3976 
3977 	if (!ext4_has_group_desc_csum(sb))
3978 		return ngroups;
3979 
3980 	for (group = 0; group < ngroups; group++) {
3981 		gdp = ext4_get_group_desc(sb, group, NULL);
3982 		if (!gdp)
3983 			continue;
3984 
3985 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3986 			break;
3987 	}
3988 
3989 	return group;
3990 }
3991 
3992 static int ext4_li_info_new(void)
3993 {
3994 	struct ext4_lazy_init *eli = NULL;
3995 
3996 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3997 	if (!eli)
3998 		return -ENOMEM;
3999 
4000 	INIT_LIST_HEAD(&eli->li_request_list);
4001 	mutex_init(&eli->li_list_mtx);
4002 
4003 	eli->li_state |= EXT4_LAZYINIT_QUIT;
4004 
4005 	ext4_li_info = eli;
4006 
4007 	return 0;
4008 }
4009 
4010 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
4011 					    ext4_group_t start)
4012 {
4013 	struct ext4_li_request *elr;
4014 
4015 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
4016 	if (!elr)
4017 		return NULL;
4018 
4019 	elr->lr_super = sb;
4020 	elr->lr_first_not_zeroed = start;
4021 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
4022 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
4023 		elr->lr_next_group = start;
4024 	} else {
4025 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
4026 	}
4027 
4028 	/*
4029 	 * Randomize first schedule time of the request to
4030 	 * spread the inode table initialization requests
4031 	 * better.
4032 	 */
4033 	elr->lr_next_sched = jiffies + (prandom_u32() %
4034 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
4035 	return elr;
4036 }
4037 
4038 int ext4_register_li_request(struct super_block *sb,
4039 			     ext4_group_t first_not_zeroed)
4040 {
4041 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4042 	struct ext4_li_request *elr = NULL;
4043 	ext4_group_t ngroups = sbi->s_groups_count;
4044 	int ret = 0;
4045 
4046 	mutex_lock(&ext4_li_mtx);
4047 	if (sbi->s_li_request != NULL) {
4048 		/*
4049 		 * Reset timeout so it can be computed again, because
4050 		 * s_li_wait_mult might have changed.
4051 		 */
4052 		sbi->s_li_request->lr_timeout = 0;
4053 		goto out;
4054 	}
4055 
4056 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4057 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
4058 	     !test_opt(sb, INIT_INODE_TABLE)))
4059 		goto out;
4060 
4061 	elr = ext4_li_request_new(sb, first_not_zeroed);
4062 	if (!elr) {
4063 		ret = -ENOMEM;
4064 		goto out;
4065 	}
4066 
4067 	if (NULL == ext4_li_info) {
4068 		ret = ext4_li_info_new();
4069 		if (ret)
4070 			goto out;
4071 	}
4072 
4073 	mutex_lock(&ext4_li_info->li_list_mtx);
4074 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4075 	mutex_unlock(&ext4_li_info->li_list_mtx);
4076 
4077 	sbi->s_li_request = elr;
4078 	/*
4079 	 * set elr to NULL here since it has been inserted to
4080 	 * the request_list and the removal and free of it is
4081 	 * handled by ext4_clear_request_list from now on.
4082 	 */
4083 	elr = NULL;
4084 
4085 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4086 		ret = ext4_run_lazyinit_thread();
4087 		if (ret)
4088 			goto out;
4089 	}
4090 out:
4091 	mutex_unlock(&ext4_li_mtx);
4092 	if (ret)
4093 		kfree(elr);
4094 	return ret;
4095 }
4096 
4097 /*
4098  * We do not need to lock anything since this is called on
4099  * module unload.
4100  */
4101 static void ext4_destroy_lazyinit_thread(void)
4102 {
4103 	/*
4104 	 * If thread exited earlier
4105 	 * there's nothing to be done.
4106 	 */
4107 	if (!ext4_li_info || !ext4_lazyinit_task)
4108 		return;
4109 
4110 	kthread_stop(ext4_lazyinit_task);
4111 }
4112 
4113 static int set_journal_csum_feature_set(struct super_block *sb)
4114 {
4115 	int ret = 1;
4116 	int compat, incompat;
4117 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4118 
4119 	if (ext4_has_metadata_csum(sb)) {
4120 		/* journal checksum v3 */
4121 		compat = 0;
4122 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4123 	} else {
4124 		/* journal checksum v1 */
4125 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4126 		incompat = 0;
4127 	}
4128 
4129 	jbd2_journal_clear_features(sbi->s_journal,
4130 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4131 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4132 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4133 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4134 		ret = jbd2_journal_set_features(sbi->s_journal,
4135 				compat, 0,
4136 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4137 				incompat);
4138 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4139 		ret = jbd2_journal_set_features(sbi->s_journal,
4140 				compat, 0,
4141 				incompat);
4142 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4143 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4144 	} else {
4145 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4146 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4147 	}
4148 
4149 	return ret;
4150 }
4151 
4152 /*
4153  * Note: calculating the overhead so we can be compatible with
4154  * historical BSD practice is quite difficult in the face of
4155  * clusters/bigalloc.  This is because multiple metadata blocks from
4156  * different block group can end up in the same allocation cluster.
4157  * Calculating the exact overhead in the face of clustered allocation
4158  * requires either O(all block bitmaps) in memory or O(number of block
4159  * groups**2) in time.  We will still calculate the superblock for
4160  * older file systems --- and if we come across with a bigalloc file
4161  * system with zero in s_overhead_clusters the estimate will be close to
4162  * correct especially for very large cluster sizes --- but for newer
4163  * file systems, it's better to calculate this figure once at mkfs
4164  * time, and store it in the superblock.  If the superblock value is
4165  * present (even for non-bigalloc file systems), we will use it.
4166  */
4167 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4168 			  char *buf)
4169 {
4170 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4171 	struct ext4_group_desc	*gdp;
4172 	ext4_fsblk_t		first_block, last_block, b;
4173 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4174 	int			s, j, count = 0;
4175 
4176 	if (!ext4_has_feature_bigalloc(sb))
4177 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
4178 			sbi->s_itb_per_group + 2);
4179 
4180 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4181 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4182 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4183 	for (i = 0; i < ngroups; i++) {
4184 		gdp = ext4_get_group_desc(sb, i, NULL);
4185 		b = ext4_block_bitmap(sb, gdp);
4186 		if (b >= first_block && b <= last_block) {
4187 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4188 			count++;
4189 		}
4190 		b = ext4_inode_bitmap(sb, gdp);
4191 		if (b >= first_block && b <= last_block) {
4192 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4193 			count++;
4194 		}
4195 		b = ext4_inode_table(sb, gdp);
4196 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4197 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4198 				int c = EXT4_B2C(sbi, b - first_block);
4199 				ext4_set_bit(c, buf);
4200 				count++;
4201 			}
4202 		if (i != grp)
4203 			continue;
4204 		s = 0;
4205 		if (ext4_bg_has_super(sb, grp)) {
4206 			ext4_set_bit(s++, buf);
4207 			count++;
4208 		}
4209 		j = ext4_bg_num_gdb(sb, grp);
4210 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4211 			ext4_error(sb, "Invalid number of block group "
4212 				   "descriptor blocks: %d", j);
4213 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4214 		}
4215 		count += j;
4216 		for (; j > 0; j--)
4217 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4218 	}
4219 	if (!count)
4220 		return 0;
4221 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4222 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4223 }
4224 
4225 /*
4226  * Compute the overhead and stash it in sbi->s_overhead
4227  */
4228 int ext4_calculate_overhead(struct super_block *sb)
4229 {
4230 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4231 	struct ext4_super_block *es = sbi->s_es;
4232 	struct inode *j_inode;
4233 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4234 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4235 	ext4_fsblk_t overhead = 0;
4236 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4237 
4238 	if (!buf)
4239 		return -ENOMEM;
4240 
4241 	/*
4242 	 * Compute the overhead (FS structures).  This is constant
4243 	 * for a given filesystem unless the number of block groups
4244 	 * changes so we cache the previous value until it does.
4245 	 */
4246 
4247 	/*
4248 	 * All of the blocks before first_data_block are overhead
4249 	 */
4250 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4251 
4252 	/*
4253 	 * Add the overhead found in each block group
4254 	 */
4255 	for (i = 0; i < ngroups; i++) {
4256 		int blks;
4257 
4258 		blks = count_overhead(sb, i, buf);
4259 		overhead += blks;
4260 		if (blks)
4261 			memset(buf, 0, PAGE_SIZE);
4262 		cond_resched();
4263 	}
4264 
4265 	/*
4266 	 * Add the internal journal blocks whether the journal has been
4267 	 * loaded or not
4268 	 */
4269 	if (sbi->s_journal && !sbi->s_journal_bdev)
4270 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4271 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4272 		/* j_inum for internal journal is non-zero */
4273 		j_inode = ext4_get_journal_inode(sb, j_inum);
4274 		if (j_inode) {
4275 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4276 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4277 			iput(j_inode);
4278 		} else {
4279 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4280 		}
4281 	}
4282 	sbi->s_overhead = overhead;
4283 	smp_wmb();
4284 	free_page((unsigned long) buf);
4285 	return 0;
4286 }
4287 
4288 static void ext4_set_resv_clusters(struct super_block *sb)
4289 {
4290 	ext4_fsblk_t resv_clusters;
4291 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4292 
4293 	/*
4294 	 * There's no need to reserve anything when we aren't using extents.
4295 	 * The space estimates are exact, there are no unwritten extents,
4296 	 * hole punching doesn't need new metadata... This is needed especially
4297 	 * to keep ext2/3 backward compatibility.
4298 	 */
4299 	if (!ext4_has_feature_extents(sb))
4300 		return;
4301 	/*
4302 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4303 	 * This should cover the situations where we can not afford to run
4304 	 * out of space like for example punch hole, or converting
4305 	 * unwritten extents in delalloc path. In most cases such
4306 	 * allocation would require 1, or 2 blocks, higher numbers are
4307 	 * very rare.
4308 	 */
4309 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4310 			 sbi->s_cluster_bits);
4311 
4312 	do_div(resv_clusters, 50);
4313 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4314 
4315 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4316 }
4317 
4318 static const char *ext4_quota_mode(struct super_block *sb)
4319 {
4320 #ifdef CONFIG_QUOTA
4321 	if (!ext4_quota_capable(sb))
4322 		return "none";
4323 
4324 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4325 		return "journalled";
4326 	else
4327 		return "writeback";
4328 #else
4329 	return "disabled";
4330 #endif
4331 }
4332 
4333 static void ext4_setup_csum_trigger(struct super_block *sb,
4334 				    enum ext4_journal_trigger_type type,
4335 				    void (*trigger)(
4336 					struct jbd2_buffer_trigger_type *type,
4337 					struct buffer_head *bh,
4338 					void *mapped_data,
4339 					size_t size))
4340 {
4341 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4342 
4343 	sbi->s_journal_triggers[type].sb = sb;
4344 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4345 }
4346 
4347 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4348 {
4349 	if (!sbi)
4350 		return;
4351 
4352 	kfree(sbi->s_blockgroup_lock);
4353 	fs_put_dax(sbi->s_daxdev);
4354 	kfree(sbi);
4355 }
4356 
4357 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4358 {
4359 	struct ext4_sb_info *sbi;
4360 
4361 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4362 	if (!sbi)
4363 		return NULL;
4364 
4365 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off);
4366 
4367 	sbi->s_blockgroup_lock =
4368 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4369 
4370 	if (!sbi->s_blockgroup_lock)
4371 		goto err_out;
4372 
4373 	sb->s_fs_info = sbi;
4374 	sbi->s_sb = sb;
4375 	return sbi;
4376 err_out:
4377 	fs_put_dax(sbi->s_daxdev);
4378 	kfree(sbi);
4379 	return NULL;
4380 }
4381 
4382 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
4383 {
4384 	struct buffer_head *bh, **group_desc;
4385 	struct ext4_super_block *es = NULL;
4386 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4387 	struct flex_groups **flex_groups;
4388 	ext4_fsblk_t block;
4389 	ext4_fsblk_t logical_sb_block;
4390 	unsigned long offset = 0;
4391 	unsigned long def_mount_opts;
4392 	struct inode *root;
4393 	int ret = -ENOMEM;
4394 	int blocksize, clustersize;
4395 	unsigned int db_count;
4396 	unsigned int i;
4397 	int needs_recovery, has_huge_files;
4398 	__u64 blocks_count;
4399 	int err = 0;
4400 	ext4_group_t first_not_zeroed;
4401 	struct ext4_fs_context *ctx = fc->fs_private;
4402 	int silent = fc->sb_flags & SB_SILENT;
4403 
4404 	/* Set defaults for the variables that will be set during parsing */
4405 	ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4406 
4407 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4408 	sbi->s_sectors_written_start =
4409 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4410 
4411 	/* -EINVAL is default */
4412 	ret = -EINVAL;
4413 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4414 	if (!blocksize) {
4415 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4416 		goto out_fail;
4417 	}
4418 
4419 	/*
4420 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4421 	 * block sizes.  We need to calculate the offset from buffer start.
4422 	 */
4423 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4424 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4425 		offset = do_div(logical_sb_block, blocksize);
4426 	} else {
4427 		logical_sb_block = sbi->s_sb_block;
4428 	}
4429 
4430 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4431 	if (IS_ERR(bh)) {
4432 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4433 		ret = PTR_ERR(bh);
4434 		goto out_fail;
4435 	}
4436 	/*
4437 	 * Note: s_es must be initialized as soon as possible because
4438 	 *       some ext4 macro-instructions depend on its value
4439 	 */
4440 	es = (struct ext4_super_block *) (bh->b_data + offset);
4441 	sbi->s_es = es;
4442 	sb->s_magic = le16_to_cpu(es->s_magic);
4443 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4444 		goto cantfind_ext4;
4445 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4446 
4447 	/* Warn if metadata_csum and gdt_csum are both set. */
4448 	if (ext4_has_feature_metadata_csum(sb) &&
4449 	    ext4_has_feature_gdt_csum(sb))
4450 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4451 			     "redundant flags; please run fsck.");
4452 
4453 	/* Check for a known checksum algorithm */
4454 	if (!ext4_verify_csum_type(sb, es)) {
4455 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4456 			 "unknown checksum algorithm.");
4457 		silent = 1;
4458 		goto cantfind_ext4;
4459 	}
4460 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4461 				ext4_orphan_file_block_trigger);
4462 
4463 	/* Load the checksum driver */
4464 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4465 	if (IS_ERR(sbi->s_chksum_driver)) {
4466 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4467 		ret = PTR_ERR(sbi->s_chksum_driver);
4468 		sbi->s_chksum_driver = NULL;
4469 		goto failed_mount;
4470 	}
4471 
4472 	/* Check superblock checksum */
4473 	if (!ext4_superblock_csum_verify(sb, es)) {
4474 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4475 			 "invalid superblock checksum.  Run e2fsck?");
4476 		silent = 1;
4477 		ret = -EFSBADCRC;
4478 		goto cantfind_ext4;
4479 	}
4480 
4481 	/* Precompute checksum seed for all metadata */
4482 	if (ext4_has_feature_csum_seed(sb))
4483 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4484 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4485 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4486 					       sizeof(es->s_uuid));
4487 
4488 	/* Set defaults before we parse the mount options */
4489 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4490 	set_opt(sb, INIT_INODE_TABLE);
4491 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4492 		set_opt(sb, DEBUG);
4493 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4494 		set_opt(sb, GRPID);
4495 	if (def_mount_opts & EXT4_DEFM_UID16)
4496 		set_opt(sb, NO_UID32);
4497 	/* xattr user namespace & acls are now defaulted on */
4498 	set_opt(sb, XATTR_USER);
4499 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4500 	set_opt(sb, POSIX_ACL);
4501 #endif
4502 	if (ext4_has_feature_fast_commit(sb))
4503 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4504 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4505 	if (ext4_has_metadata_csum(sb))
4506 		set_opt(sb, JOURNAL_CHECKSUM);
4507 
4508 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4509 		set_opt(sb, JOURNAL_DATA);
4510 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4511 		set_opt(sb, ORDERED_DATA);
4512 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4513 		set_opt(sb, WRITEBACK_DATA);
4514 
4515 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4516 		set_opt(sb, ERRORS_PANIC);
4517 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4518 		set_opt(sb, ERRORS_CONT);
4519 	else
4520 		set_opt(sb, ERRORS_RO);
4521 	/* block_validity enabled by default; disable with noblock_validity */
4522 	set_opt(sb, BLOCK_VALIDITY);
4523 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4524 		set_opt(sb, DISCARD);
4525 
4526 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4527 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4528 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4529 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4530 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4531 
4532 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4533 		set_opt(sb, BARRIER);
4534 
4535 	/*
4536 	 * enable delayed allocation by default
4537 	 * Use -o nodelalloc to turn it off
4538 	 */
4539 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4540 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4541 		set_opt(sb, DELALLOC);
4542 
4543 	/*
4544 	 * set default s_li_wait_mult for lazyinit, for the case there is
4545 	 * no mount option specified.
4546 	 */
4547 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4548 
4549 	if (le32_to_cpu(es->s_log_block_size) >
4550 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4551 		ext4_msg(sb, KERN_ERR,
4552 			 "Invalid log block size: %u",
4553 			 le32_to_cpu(es->s_log_block_size));
4554 		goto failed_mount;
4555 	}
4556 	if (le32_to_cpu(es->s_log_cluster_size) >
4557 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4558 		ext4_msg(sb, KERN_ERR,
4559 			 "Invalid log cluster size: %u",
4560 			 le32_to_cpu(es->s_log_cluster_size));
4561 		goto failed_mount;
4562 	}
4563 
4564 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4565 
4566 	if (blocksize == PAGE_SIZE)
4567 		set_opt(sb, DIOREAD_NOLOCK);
4568 
4569 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4570 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4571 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4572 	} else {
4573 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4574 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4575 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4576 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4577 				 sbi->s_first_ino);
4578 			goto failed_mount;
4579 		}
4580 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4581 		    (!is_power_of_2(sbi->s_inode_size)) ||
4582 		    (sbi->s_inode_size > blocksize)) {
4583 			ext4_msg(sb, KERN_ERR,
4584 			       "unsupported inode size: %d",
4585 			       sbi->s_inode_size);
4586 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4587 			goto failed_mount;
4588 		}
4589 		/*
4590 		 * i_atime_extra is the last extra field available for
4591 		 * [acm]times in struct ext4_inode. Checking for that
4592 		 * field should suffice to ensure we have extra space
4593 		 * for all three.
4594 		 */
4595 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4596 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4597 			sb->s_time_gran = 1;
4598 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4599 		} else {
4600 			sb->s_time_gran = NSEC_PER_SEC;
4601 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4602 		}
4603 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4604 	}
4605 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4606 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4607 			EXT4_GOOD_OLD_INODE_SIZE;
4608 		if (ext4_has_feature_extra_isize(sb)) {
4609 			unsigned v, max = (sbi->s_inode_size -
4610 					   EXT4_GOOD_OLD_INODE_SIZE);
4611 
4612 			v = le16_to_cpu(es->s_want_extra_isize);
4613 			if (v > max) {
4614 				ext4_msg(sb, KERN_ERR,
4615 					 "bad s_want_extra_isize: %d", v);
4616 				goto failed_mount;
4617 			}
4618 			if (sbi->s_want_extra_isize < v)
4619 				sbi->s_want_extra_isize = v;
4620 
4621 			v = le16_to_cpu(es->s_min_extra_isize);
4622 			if (v > max) {
4623 				ext4_msg(sb, KERN_ERR,
4624 					 "bad s_min_extra_isize: %d", v);
4625 				goto failed_mount;
4626 			}
4627 			if (sbi->s_want_extra_isize < v)
4628 				sbi->s_want_extra_isize = v;
4629 		}
4630 	}
4631 
4632 	err = parse_apply_sb_mount_options(sb, ctx);
4633 	if (err < 0)
4634 		goto failed_mount;
4635 
4636 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4637 
4638 	err = ext4_check_opt_consistency(fc, sb);
4639 	if (err < 0)
4640 		goto failed_mount;
4641 
4642 	err = ext4_apply_options(fc, sb);
4643 	if (err < 0)
4644 		goto failed_mount;
4645 
4646 #if IS_ENABLED(CONFIG_UNICODE)
4647 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4648 		const struct ext4_sb_encodings *encoding_info;
4649 		struct unicode_map *encoding;
4650 		__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4651 
4652 		encoding_info = ext4_sb_read_encoding(es);
4653 		if (!encoding_info) {
4654 			ext4_msg(sb, KERN_ERR,
4655 				 "Encoding requested by superblock is unknown");
4656 			goto failed_mount;
4657 		}
4658 
4659 		encoding = utf8_load(encoding_info->version);
4660 		if (IS_ERR(encoding)) {
4661 			ext4_msg(sb, KERN_ERR,
4662 				 "can't mount with superblock charset: %s-%u.%u.%u "
4663 				 "not supported by the kernel. flags: 0x%x.",
4664 				 encoding_info->name,
4665 				 unicode_major(encoding_info->version),
4666 				 unicode_minor(encoding_info->version),
4667 				 unicode_rev(encoding_info->version),
4668 				 encoding_flags);
4669 			goto failed_mount;
4670 		}
4671 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4672 			 "%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4673 			 unicode_major(encoding_info->version),
4674 			 unicode_minor(encoding_info->version),
4675 			 unicode_rev(encoding_info->version),
4676 			 encoding_flags);
4677 
4678 		sb->s_encoding = encoding;
4679 		sb->s_encoding_flags = encoding_flags;
4680 	}
4681 #endif
4682 
4683 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4684 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4685 		/* can't mount with both data=journal and dioread_nolock. */
4686 		clear_opt(sb, DIOREAD_NOLOCK);
4687 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4688 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4689 			ext4_msg(sb, KERN_ERR, "can't mount with "
4690 				 "both data=journal and delalloc");
4691 			goto failed_mount;
4692 		}
4693 		if (test_opt(sb, DAX_ALWAYS)) {
4694 			ext4_msg(sb, KERN_ERR, "can't mount with "
4695 				 "both data=journal and dax");
4696 			goto failed_mount;
4697 		}
4698 		if (ext4_has_feature_encrypt(sb)) {
4699 			ext4_msg(sb, KERN_WARNING,
4700 				 "encrypted files will use data=ordered "
4701 				 "instead of data journaling mode");
4702 		}
4703 		if (test_opt(sb, DELALLOC))
4704 			clear_opt(sb, DELALLOC);
4705 	} else {
4706 		sb->s_iflags |= SB_I_CGROUPWB;
4707 	}
4708 
4709 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4710 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4711 
4712 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4713 	    (ext4_has_compat_features(sb) ||
4714 	     ext4_has_ro_compat_features(sb) ||
4715 	     ext4_has_incompat_features(sb)))
4716 		ext4_msg(sb, KERN_WARNING,
4717 		       "feature flags set on rev 0 fs, "
4718 		       "running e2fsck is recommended");
4719 
4720 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4721 		set_opt2(sb, HURD_COMPAT);
4722 		if (ext4_has_feature_64bit(sb)) {
4723 			ext4_msg(sb, KERN_ERR,
4724 				 "The Hurd can't support 64-bit file systems");
4725 			goto failed_mount;
4726 		}
4727 
4728 		/*
4729 		 * ea_inode feature uses l_i_version field which is not
4730 		 * available in HURD_COMPAT mode.
4731 		 */
4732 		if (ext4_has_feature_ea_inode(sb)) {
4733 			ext4_msg(sb, KERN_ERR,
4734 				 "ea_inode feature is not supported for Hurd");
4735 			goto failed_mount;
4736 		}
4737 	}
4738 
4739 	if (IS_EXT2_SB(sb)) {
4740 		if (ext2_feature_set_ok(sb))
4741 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4742 				 "using the ext4 subsystem");
4743 		else {
4744 			/*
4745 			 * If we're probing be silent, if this looks like
4746 			 * it's actually an ext[34] filesystem.
4747 			 */
4748 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4749 				goto failed_mount;
4750 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4751 				 "to feature incompatibilities");
4752 			goto failed_mount;
4753 		}
4754 	}
4755 
4756 	if (IS_EXT3_SB(sb)) {
4757 		if (ext3_feature_set_ok(sb))
4758 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4759 				 "using the ext4 subsystem");
4760 		else {
4761 			/*
4762 			 * If we're probing be silent, if this looks like
4763 			 * it's actually an ext4 filesystem.
4764 			 */
4765 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4766 				goto failed_mount;
4767 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4768 				 "to feature incompatibilities");
4769 			goto failed_mount;
4770 		}
4771 	}
4772 
4773 	/*
4774 	 * Check feature flags regardless of the revision level, since we
4775 	 * previously didn't change the revision level when setting the flags,
4776 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4777 	 */
4778 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4779 		goto failed_mount;
4780 
4781 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4782 		ext4_msg(sb, KERN_ERR,
4783 			 "Number of reserved GDT blocks insanely large: %d",
4784 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4785 		goto failed_mount;
4786 	}
4787 
4788 	if (sbi->s_daxdev) {
4789 		if (blocksize == PAGE_SIZE)
4790 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4791 		else
4792 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4793 	}
4794 
4795 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4796 		if (ext4_has_feature_inline_data(sb)) {
4797 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4798 					" that may contain inline data");
4799 			goto failed_mount;
4800 		}
4801 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4802 			ext4_msg(sb, KERN_ERR,
4803 				"DAX unsupported by block device.");
4804 			goto failed_mount;
4805 		}
4806 	}
4807 
4808 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4809 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4810 			 es->s_encryption_level);
4811 		goto failed_mount;
4812 	}
4813 
4814 	if (sb->s_blocksize != blocksize) {
4815 		/*
4816 		 * bh must be released before kill_bdev(), otherwise
4817 		 * it won't be freed and its page also. kill_bdev()
4818 		 * is called by sb_set_blocksize().
4819 		 */
4820 		brelse(bh);
4821 		/* Validate the filesystem blocksize */
4822 		if (!sb_set_blocksize(sb, blocksize)) {
4823 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4824 					blocksize);
4825 			bh = NULL;
4826 			goto failed_mount;
4827 		}
4828 
4829 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4830 		offset = do_div(logical_sb_block, blocksize);
4831 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4832 		if (IS_ERR(bh)) {
4833 			ext4_msg(sb, KERN_ERR,
4834 			       "Can't read superblock on 2nd try");
4835 			ret = PTR_ERR(bh);
4836 			bh = NULL;
4837 			goto failed_mount;
4838 		}
4839 		es = (struct ext4_super_block *)(bh->b_data + offset);
4840 		sbi->s_es = es;
4841 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4842 			ext4_msg(sb, KERN_ERR,
4843 			       "Magic mismatch, very weird!");
4844 			goto failed_mount;
4845 		}
4846 	}
4847 
4848 	has_huge_files = ext4_has_feature_huge_file(sb);
4849 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4850 						      has_huge_files);
4851 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4852 
4853 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4854 	if (ext4_has_feature_64bit(sb)) {
4855 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4856 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4857 		    !is_power_of_2(sbi->s_desc_size)) {
4858 			ext4_msg(sb, KERN_ERR,
4859 			       "unsupported descriptor size %lu",
4860 			       sbi->s_desc_size);
4861 			goto failed_mount;
4862 		}
4863 	} else
4864 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4865 
4866 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4867 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4868 
4869 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4870 	if (sbi->s_inodes_per_block == 0)
4871 		goto cantfind_ext4;
4872 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4873 	    sbi->s_inodes_per_group > blocksize * 8) {
4874 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4875 			 sbi->s_inodes_per_group);
4876 		goto failed_mount;
4877 	}
4878 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4879 					sbi->s_inodes_per_block;
4880 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4881 	sbi->s_sbh = bh;
4882 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4883 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4884 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4885 
4886 	for (i = 0; i < 4; i++)
4887 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4888 	sbi->s_def_hash_version = es->s_def_hash_version;
4889 	if (ext4_has_feature_dir_index(sb)) {
4890 		i = le32_to_cpu(es->s_flags);
4891 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4892 			sbi->s_hash_unsigned = 3;
4893 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4894 #ifdef __CHAR_UNSIGNED__
4895 			if (!sb_rdonly(sb))
4896 				es->s_flags |=
4897 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4898 			sbi->s_hash_unsigned = 3;
4899 #else
4900 			if (!sb_rdonly(sb))
4901 				es->s_flags |=
4902 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4903 #endif
4904 		}
4905 	}
4906 
4907 	/* Handle clustersize */
4908 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4909 	if (ext4_has_feature_bigalloc(sb)) {
4910 		if (clustersize < blocksize) {
4911 			ext4_msg(sb, KERN_ERR,
4912 				 "cluster size (%d) smaller than "
4913 				 "block size (%d)", clustersize, blocksize);
4914 			goto failed_mount;
4915 		}
4916 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4917 			le32_to_cpu(es->s_log_block_size);
4918 		sbi->s_clusters_per_group =
4919 			le32_to_cpu(es->s_clusters_per_group);
4920 		if (sbi->s_clusters_per_group > blocksize * 8) {
4921 			ext4_msg(sb, KERN_ERR,
4922 				 "#clusters per group too big: %lu",
4923 				 sbi->s_clusters_per_group);
4924 			goto failed_mount;
4925 		}
4926 		if (sbi->s_blocks_per_group !=
4927 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4928 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4929 				 "clusters per group (%lu) inconsistent",
4930 				 sbi->s_blocks_per_group,
4931 				 sbi->s_clusters_per_group);
4932 			goto failed_mount;
4933 		}
4934 	} else {
4935 		if (clustersize != blocksize) {
4936 			ext4_msg(sb, KERN_ERR,
4937 				 "fragment/cluster size (%d) != "
4938 				 "block size (%d)", clustersize, blocksize);
4939 			goto failed_mount;
4940 		}
4941 		if (sbi->s_blocks_per_group > blocksize * 8) {
4942 			ext4_msg(sb, KERN_ERR,
4943 				 "#blocks per group too big: %lu",
4944 				 sbi->s_blocks_per_group);
4945 			goto failed_mount;
4946 		}
4947 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4948 		sbi->s_cluster_bits = 0;
4949 	}
4950 	sbi->s_cluster_ratio = clustersize / blocksize;
4951 
4952 	/* Do we have standard group size of clustersize * 8 blocks ? */
4953 	if (sbi->s_blocks_per_group == clustersize << 3)
4954 		set_opt2(sb, STD_GROUP_SIZE);
4955 
4956 	/*
4957 	 * Test whether we have more sectors than will fit in sector_t,
4958 	 * and whether the max offset is addressable by the page cache.
4959 	 */
4960 	err = generic_check_addressable(sb->s_blocksize_bits,
4961 					ext4_blocks_count(es));
4962 	if (err) {
4963 		ext4_msg(sb, KERN_ERR, "filesystem"
4964 			 " too large to mount safely on this system");
4965 		goto failed_mount;
4966 	}
4967 
4968 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4969 		goto cantfind_ext4;
4970 
4971 	/* check blocks count against device size */
4972 	blocks_count = sb_bdev_nr_blocks(sb);
4973 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4974 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4975 		       "exceeds size of device (%llu blocks)",
4976 		       ext4_blocks_count(es), blocks_count);
4977 		goto failed_mount;
4978 	}
4979 
4980 	/*
4981 	 * It makes no sense for the first data block to be beyond the end
4982 	 * of the filesystem.
4983 	 */
4984 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4985 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4986 			 "block %u is beyond end of filesystem (%llu)",
4987 			 le32_to_cpu(es->s_first_data_block),
4988 			 ext4_blocks_count(es));
4989 		goto failed_mount;
4990 	}
4991 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4992 	    (sbi->s_cluster_ratio == 1)) {
4993 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4994 			 "block is 0 with a 1k block and cluster size");
4995 		goto failed_mount;
4996 	}
4997 
4998 	blocks_count = (ext4_blocks_count(es) -
4999 			le32_to_cpu(es->s_first_data_block) +
5000 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
5001 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
5002 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
5003 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
5004 		       "(block count %llu, first data block %u, "
5005 		       "blocks per group %lu)", blocks_count,
5006 		       ext4_blocks_count(es),
5007 		       le32_to_cpu(es->s_first_data_block),
5008 		       EXT4_BLOCKS_PER_GROUP(sb));
5009 		goto failed_mount;
5010 	}
5011 	sbi->s_groups_count = blocks_count;
5012 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
5013 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
5014 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
5015 	    le32_to_cpu(es->s_inodes_count)) {
5016 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
5017 			 le32_to_cpu(es->s_inodes_count),
5018 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
5019 		ret = -EINVAL;
5020 		goto failed_mount;
5021 	}
5022 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
5023 		   EXT4_DESC_PER_BLOCK(sb);
5024 	if (ext4_has_feature_meta_bg(sb)) {
5025 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
5026 			ext4_msg(sb, KERN_WARNING,
5027 				 "first meta block group too large: %u "
5028 				 "(group descriptor block count %u)",
5029 				 le32_to_cpu(es->s_first_meta_bg), db_count);
5030 			goto failed_mount;
5031 		}
5032 	}
5033 	rcu_assign_pointer(sbi->s_group_desc,
5034 			   kvmalloc_array(db_count,
5035 					  sizeof(struct buffer_head *),
5036 					  GFP_KERNEL));
5037 	if (sbi->s_group_desc == NULL) {
5038 		ext4_msg(sb, KERN_ERR, "not enough memory");
5039 		ret = -ENOMEM;
5040 		goto failed_mount;
5041 	}
5042 
5043 	bgl_lock_init(sbi->s_blockgroup_lock);
5044 
5045 	/* Pre-read the descriptors into the buffer cache */
5046 	for (i = 0; i < db_count; i++) {
5047 		block = descriptor_loc(sb, logical_sb_block, i);
5048 		ext4_sb_breadahead_unmovable(sb, block);
5049 	}
5050 
5051 	for (i = 0; i < db_count; i++) {
5052 		struct buffer_head *bh;
5053 
5054 		block = descriptor_loc(sb, logical_sb_block, i);
5055 		bh = ext4_sb_bread_unmovable(sb, block);
5056 		if (IS_ERR(bh)) {
5057 			ext4_msg(sb, KERN_ERR,
5058 			       "can't read group descriptor %d", i);
5059 			db_count = i;
5060 			ret = PTR_ERR(bh);
5061 			goto failed_mount2;
5062 		}
5063 		rcu_read_lock();
5064 		rcu_dereference(sbi->s_group_desc)[i] = bh;
5065 		rcu_read_unlock();
5066 	}
5067 	sbi->s_gdb_count = db_count;
5068 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
5069 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
5070 		ret = -EFSCORRUPTED;
5071 		goto failed_mount2;
5072 	}
5073 
5074 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5075 	spin_lock_init(&sbi->s_error_lock);
5076 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5077 
5078 	/* Register extent status tree shrinker */
5079 	if (ext4_es_register_shrinker(sbi))
5080 		goto failed_mount3;
5081 
5082 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5083 	sbi->s_extent_max_zeroout_kb = 32;
5084 
5085 	/*
5086 	 * set up enough so that it can read an inode
5087 	 */
5088 	sb->s_op = &ext4_sops;
5089 	sb->s_export_op = &ext4_export_ops;
5090 	sb->s_xattr = ext4_xattr_handlers;
5091 #ifdef CONFIG_FS_ENCRYPTION
5092 	sb->s_cop = &ext4_cryptops;
5093 #endif
5094 #ifdef CONFIG_FS_VERITY
5095 	sb->s_vop = &ext4_verityops;
5096 #endif
5097 #ifdef CONFIG_QUOTA
5098 	sb->dq_op = &ext4_quota_operations;
5099 	if (ext4_has_feature_quota(sb))
5100 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5101 	else
5102 		sb->s_qcop = &ext4_qctl_operations;
5103 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5104 #endif
5105 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5106 
5107 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5108 	mutex_init(&sbi->s_orphan_lock);
5109 
5110 	/* Initialize fast commit stuff */
5111 	atomic_set(&sbi->s_fc_subtid, 0);
5112 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
5113 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
5114 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
5115 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
5116 	sbi->s_fc_bytes = 0;
5117 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
5118 	sbi->s_fc_ineligible_tid = 0;
5119 	spin_lock_init(&sbi->s_fc_lock);
5120 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
5121 	sbi->s_fc_replay_state.fc_regions = NULL;
5122 	sbi->s_fc_replay_state.fc_regions_size = 0;
5123 	sbi->s_fc_replay_state.fc_regions_used = 0;
5124 	sbi->s_fc_replay_state.fc_regions_valid = 0;
5125 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
5126 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
5127 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
5128 
5129 	sb->s_root = NULL;
5130 
5131 	needs_recovery = (es->s_last_orphan != 0 ||
5132 			  ext4_has_feature_orphan_present(sb) ||
5133 			  ext4_has_feature_journal_needs_recovery(sb));
5134 
5135 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5136 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5137 			goto failed_mount3a;
5138 
5139 	/*
5140 	 * The first inode we look at is the journal inode.  Don't try
5141 	 * root first: it may be modified in the journal!
5142 	 */
5143 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5144 		err = ext4_load_journal(sb, es, ctx->journal_devnum);
5145 		if (err)
5146 			goto failed_mount3a;
5147 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5148 		   ext4_has_feature_journal_needs_recovery(sb)) {
5149 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5150 		       "suppressed and not mounted read-only");
5151 		goto failed_mount_wq;
5152 	} else {
5153 		/* Nojournal mode, all journal mount options are illegal */
5154 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5155 			ext4_msg(sb, KERN_ERR, "can't mount with "
5156 				 "journal_checksum, fs mounted w/o journal");
5157 			goto failed_mount_wq;
5158 		}
5159 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5160 			ext4_msg(sb, KERN_ERR, "can't mount with "
5161 				 "journal_async_commit, fs mounted w/o journal");
5162 			goto failed_mount_wq;
5163 		}
5164 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5165 			ext4_msg(sb, KERN_ERR, "can't mount with "
5166 				 "commit=%lu, fs mounted w/o journal",
5167 				 sbi->s_commit_interval / HZ);
5168 			goto failed_mount_wq;
5169 		}
5170 		if (EXT4_MOUNT_DATA_FLAGS &
5171 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5172 			ext4_msg(sb, KERN_ERR, "can't mount with "
5173 				 "data=, fs mounted w/o journal");
5174 			goto failed_mount_wq;
5175 		}
5176 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5177 		clear_opt(sb, JOURNAL_CHECKSUM);
5178 		clear_opt(sb, DATA_FLAGS);
5179 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5180 		sbi->s_journal = NULL;
5181 		needs_recovery = 0;
5182 		goto no_journal;
5183 	}
5184 
5185 	if (ext4_has_feature_64bit(sb) &&
5186 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5187 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
5188 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
5189 		goto failed_mount_wq;
5190 	}
5191 
5192 	if (!set_journal_csum_feature_set(sb)) {
5193 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
5194 			 "feature set");
5195 		goto failed_mount_wq;
5196 	}
5197 
5198 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
5199 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5200 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
5201 		ext4_msg(sb, KERN_ERR,
5202 			"Failed to set fast commit journal feature");
5203 		goto failed_mount_wq;
5204 	}
5205 
5206 	/* We have now updated the journal if required, so we can
5207 	 * validate the data journaling mode. */
5208 	switch (test_opt(sb, DATA_FLAGS)) {
5209 	case 0:
5210 		/* No mode set, assume a default based on the journal
5211 		 * capabilities: ORDERED_DATA if the journal can
5212 		 * cope, else JOURNAL_DATA
5213 		 */
5214 		if (jbd2_journal_check_available_features
5215 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5216 			set_opt(sb, ORDERED_DATA);
5217 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
5218 		} else {
5219 			set_opt(sb, JOURNAL_DATA);
5220 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
5221 		}
5222 		break;
5223 
5224 	case EXT4_MOUNT_ORDERED_DATA:
5225 	case EXT4_MOUNT_WRITEBACK_DATA:
5226 		if (!jbd2_journal_check_available_features
5227 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5228 			ext4_msg(sb, KERN_ERR, "Journal does not support "
5229 			       "requested data journaling mode");
5230 			goto failed_mount_wq;
5231 		}
5232 		break;
5233 	default:
5234 		break;
5235 	}
5236 
5237 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5238 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5239 		ext4_msg(sb, KERN_ERR, "can't mount with "
5240 			"journal_async_commit in data=ordered mode");
5241 		goto failed_mount_wq;
5242 	}
5243 
5244 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5245 
5246 	sbi->s_journal->j_submit_inode_data_buffers =
5247 		ext4_journal_submit_inode_data_buffers;
5248 	sbi->s_journal->j_finish_inode_data_buffers =
5249 		ext4_journal_finish_inode_data_buffers;
5250 
5251 no_journal:
5252 	if (!test_opt(sb, NO_MBCACHE)) {
5253 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5254 		if (!sbi->s_ea_block_cache) {
5255 			ext4_msg(sb, KERN_ERR,
5256 				 "Failed to create ea_block_cache");
5257 			goto failed_mount_wq;
5258 		}
5259 
5260 		if (ext4_has_feature_ea_inode(sb)) {
5261 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5262 			if (!sbi->s_ea_inode_cache) {
5263 				ext4_msg(sb, KERN_ERR,
5264 					 "Failed to create ea_inode_cache");
5265 				goto failed_mount_wq;
5266 			}
5267 		}
5268 	}
5269 
5270 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
5271 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5272 		goto failed_mount_wq;
5273 	}
5274 
5275 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
5276 	    !ext4_has_feature_encrypt(sb)) {
5277 		ext4_set_feature_encrypt(sb);
5278 		ext4_commit_super(sb);
5279 	}
5280 
5281 	/*
5282 	 * Get the # of file system overhead blocks from the
5283 	 * superblock if present.
5284 	 */
5285 	if (es->s_overhead_clusters)
5286 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5287 	else {
5288 		err = ext4_calculate_overhead(sb);
5289 		if (err)
5290 			goto failed_mount_wq;
5291 	}
5292 
5293 	/*
5294 	 * The maximum number of concurrent works can be high and
5295 	 * concurrency isn't really necessary.  Limit it to 1.
5296 	 */
5297 	EXT4_SB(sb)->rsv_conversion_wq =
5298 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5299 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5300 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5301 		ret = -ENOMEM;
5302 		goto failed_mount4;
5303 	}
5304 
5305 	/*
5306 	 * The jbd2_journal_load will have done any necessary log recovery,
5307 	 * so we can safely mount the rest of the filesystem now.
5308 	 */
5309 
5310 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5311 	if (IS_ERR(root)) {
5312 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5313 		ret = PTR_ERR(root);
5314 		root = NULL;
5315 		goto failed_mount4;
5316 	}
5317 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5318 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5319 		iput(root);
5320 		goto failed_mount4;
5321 	}
5322 
5323 	sb->s_root = d_make_root(root);
5324 	if (!sb->s_root) {
5325 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5326 		ret = -ENOMEM;
5327 		goto failed_mount4;
5328 	}
5329 
5330 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5331 	if (ret == -EROFS) {
5332 		sb->s_flags |= SB_RDONLY;
5333 		ret = 0;
5334 	} else if (ret)
5335 		goto failed_mount4a;
5336 
5337 	ext4_set_resv_clusters(sb);
5338 
5339 	if (test_opt(sb, BLOCK_VALIDITY)) {
5340 		err = ext4_setup_system_zone(sb);
5341 		if (err) {
5342 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5343 				 "zone (%d)", err);
5344 			goto failed_mount4a;
5345 		}
5346 	}
5347 	ext4_fc_replay_cleanup(sb);
5348 
5349 	ext4_ext_init(sb);
5350 
5351 	/*
5352 	 * Enable optimize_scan if number of groups is > threshold. This can be
5353 	 * turned off by passing "mb_optimize_scan=0". This can also be
5354 	 * turned on forcefully by passing "mb_optimize_scan=1".
5355 	 */
5356 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5357 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5358 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5359 		else
5360 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5361 	}
5362 
5363 	err = ext4_mb_init(sb);
5364 	if (err) {
5365 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5366 			 err);
5367 		goto failed_mount5;
5368 	}
5369 
5370 	/*
5371 	 * We can only set up the journal commit callback once
5372 	 * mballoc is initialized
5373 	 */
5374 	if (sbi->s_journal)
5375 		sbi->s_journal->j_commit_callback =
5376 			ext4_journal_commit_callback;
5377 
5378 	block = ext4_count_free_clusters(sb);
5379 	ext4_free_blocks_count_set(sbi->s_es,
5380 				   EXT4_C2B(sbi, block));
5381 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5382 				  GFP_KERNEL);
5383 	if (!err) {
5384 		unsigned long freei = ext4_count_free_inodes(sb);
5385 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5386 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5387 					  GFP_KERNEL);
5388 	}
5389 	/*
5390 	 * Update the checksum after updating free space/inode
5391 	 * counters.  Otherwise the superblock can have an incorrect
5392 	 * checksum in the buffer cache until it is written out and
5393 	 * e2fsprogs programs trying to open a file system immediately
5394 	 * after it is mounted can fail.
5395 	 */
5396 	ext4_superblock_csum_set(sb);
5397 	if (!err)
5398 		err = percpu_counter_init(&sbi->s_dirs_counter,
5399 					  ext4_count_dirs(sb), GFP_KERNEL);
5400 	if (!err)
5401 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5402 					  GFP_KERNEL);
5403 	if (!err)
5404 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5405 					  GFP_KERNEL);
5406 	if (!err)
5407 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5408 
5409 	if (err) {
5410 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5411 		goto failed_mount6;
5412 	}
5413 
5414 	if (ext4_has_feature_flex_bg(sb))
5415 		if (!ext4_fill_flex_info(sb)) {
5416 			ext4_msg(sb, KERN_ERR,
5417 			       "unable to initialize "
5418 			       "flex_bg meta info!");
5419 			ret = -ENOMEM;
5420 			goto failed_mount6;
5421 		}
5422 
5423 	err = ext4_register_li_request(sb, first_not_zeroed);
5424 	if (err)
5425 		goto failed_mount6;
5426 
5427 	err = ext4_register_sysfs(sb);
5428 	if (err)
5429 		goto failed_mount7;
5430 
5431 	err = ext4_init_orphan_info(sb);
5432 	if (err)
5433 		goto failed_mount8;
5434 #ifdef CONFIG_QUOTA
5435 	/* Enable quota usage during mount. */
5436 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5437 		err = ext4_enable_quotas(sb);
5438 		if (err)
5439 			goto failed_mount9;
5440 	}
5441 #endif  /* CONFIG_QUOTA */
5442 
5443 	/*
5444 	 * Save the original bdev mapping's wb_err value which could be
5445 	 * used to detect the metadata async write error.
5446 	 */
5447 	spin_lock_init(&sbi->s_bdev_wb_lock);
5448 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5449 				 &sbi->s_bdev_wb_err);
5450 	sb->s_bdev->bd_super = sb;
5451 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5452 	ext4_orphan_cleanup(sb, es);
5453 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5454 	if (needs_recovery) {
5455 		ext4_msg(sb, KERN_INFO, "recovery complete");
5456 		err = ext4_mark_recovery_complete(sb, es);
5457 		if (err)
5458 			goto failed_mount9;
5459 	}
5460 
5461 	if (test_opt(sb, DISCARD)) {
5462 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5463 		if (!blk_queue_discard(q))
5464 			ext4_msg(sb, KERN_WARNING,
5465 				 "mounting with \"discard\" option, but "
5466 				 "the device does not support discard");
5467 	}
5468 
5469 	if (es->s_error_count)
5470 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5471 
5472 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5473 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5474 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5475 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5476 	atomic_set(&sbi->s_warning_count, 0);
5477 	atomic_set(&sbi->s_msg_count, 0);
5478 
5479 	return 0;
5480 
5481 cantfind_ext4:
5482 	if (!silent)
5483 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5484 	goto failed_mount;
5485 
5486 failed_mount9:
5487 	ext4_release_orphan_info(sb);
5488 failed_mount8:
5489 	ext4_unregister_sysfs(sb);
5490 	kobject_put(&sbi->s_kobj);
5491 failed_mount7:
5492 	ext4_unregister_li_request(sb);
5493 failed_mount6:
5494 	ext4_mb_release(sb);
5495 	rcu_read_lock();
5496 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5497 	if (flex_groups) {
5498 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5499 			kvfree(flex_groups[i]);
5500 		kvfree(flex_groups);
5501 	}
5502 	rcu_read_unlock();
5503 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5504 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5505 	percpu_counter_destroy(&sbi->s_dirs_counter);
5506 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5507 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5508 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5509 failed_mount5:
5510 	ext4_ext_release(sb);
5511 	ext4_release_system_zone(sb);
5512 failed_mount4a:
5513 	dput(sb->s_root);
5514 	sb->s_root = NULL;
5515 failed_mount4:
5516 	ext4_msg(sb, KERN_ERR, "mount failed");
5517 	if (EXT4_SB(sb)->rsv_conversion_wq)
5518 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5519 failed_mount_wq:
5520 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5521 	sbi->s_ea_inode_cache = NULL;
5522 
5523 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5524 	sbi->s_ea_block_cache = NULL;
5525 
5526 	if (sbi->s_journal) {
5527 		/* flush s_error_work before journal destroy. */
5528 		flush_work(&sbi->s_error_work);
5529 		jbd2_journal_destroy(sbi->s_journal);
5530 		sbi->s_journal = NULL;
5531 	}
5532 failed_mount3a:
5533 	ext4_es_unregister_shrinker(sbi);
5534 failed_mount3:
5535 	/* flush s_error_work before sbi destroy */
5536 	flush_work(&sbi->s_error_work);
5537 	del_timer_sync(&sbi->s_err_report);
5538 	ext4_stop_mmpd(sbi);
5539 failed_mount2:
5540 	rcu_read_lock();
5541 	group_desc = rcu_dereference(sbi->s_group_desc);
5542 	for (i = 0; i < db_count; i++)
5543 		brelse(group_desc[i]);
5544 	kvfree(group_desc);
5545 	rcu_read_unlock();
5546 failed_mount:
5547 	if (sbi->s_chksum_driver)
5548 		crypto_free_shash(sbi->s_chksum_driver);
5549 
5550 #if IS_ENABLED(CONFIG_UNICODE)
5551 	utf8_unload(sb->s_encoding);
5552 #endif
5553 
5554 #ifdef CONFIG_QUOTA
5555 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5556 		kfree(get_qf_name(sb, sbi, i));
5557 #endif
5558 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5559 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5560 	brelse(bh);
5561 	ext4_blkdev_remove(sbi);
5562 out_fail:
5563 	sb->s_fs_info = NULL;
5564 	return err ? err : ret;
5565 }
5566 
5567 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5568 {
5569 	struct ext4_fs_context *ctx = fc->fs_private;
5570 	struct ext4_sb_info *sbi;
5571 	const char *descr;
5572 	int ret;
5573 
5574 	sbi = ext4_alloc_sbi(sb);
5575 	if (!sbi)
5576 		return -ENOMEM;
5577 
5578 	fc->s_fs_info = sbi;
5579 
5580 	/* Cleanup superblock name */
5581 	strreplace(sb->s_id, '/', '!');
5582 
5583 	sbi->s_sb_block = 1;	/* Default super block location */
5584 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5585 		sbi->s_sb_block = ctx->s_sb_block;
5586 
5587 	ret = __ext4_fill_super(fc, sb);
5588 	if (ret < 0)
5589 		goto free_sbi;
5590 
5591 	if (sbi->s_journal) {
5592 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5593 			descr = " journalled data mode";
5594 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5595 			descr = " ordered data mode";
5596 		else
5597 			descr = " writeback data mode";
5598 	} else
5599 		descr = "out journal";
5600 
5601 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5602 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5603 			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
5604 
5605 	return 0;
5606 
5607 free_sbi:
5608 	ext4_free_sbi(sbi);
5609 	fc->s_fs_info = NULL;
5610 	return ret;
5611 }
5612 
5613 static int ext4_get_tree(struct fs_context *fc)
5614 {
5615 	return get_tree_bdev(fc, ext4_fill_super);
5616 }
5617 
5618 /*
5619  * Setup any per-fs journal parameters now.  We'll do this both on
5620  * initial mount, once the journal has been initialised but before we've
5621  * done any recovery; and again on any subsequent remount.
5622  */
5623 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5624 {
5625 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5626 
5627 	journal->j_commit_interval = sbi->s_commit_interval;
5628 	journal->j_min_batch_time = sbi->s_min_batch_time;
5629 	journal->j_max_batch_time = sbi->s_max_batch_time;
5630 	ext4_fc_init(sb, journal);
5631 
5632 	write_lock(&journal->j_state_lock);
5633 	if (test_opt(sb, BARRIER))
5634 		journal->j_flags |= JBD2_BARRIER;
5635 	else
5636 		journal->j_flags &= ~JBD2_BARRIER;
5637 	if (test_opt(sb, DATA_ERR_ABORT))
5638 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5639 	else
5640 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5641 	write_unlock(&journal->j_state_lock);
5642 }
5643 
5644 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5645 					     unsigned int journal_inum)
5646 {
5647 	struct inode *journal_inode;
5648 
5649 	/*
5650 	 * Test for the existence of a valid inode on disk.  Bad things
5651 	 * happen if we iget() an unused inode, as the subsequent iput()
5652 	 * will try to delete it.
5653 	 */
5654 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5655 	if (IS_ERR(journal_inode)) {
5656 		ext4_msg(sb, KERN_ERR, "no journal found");
5657 		return NULL;
5658 	}
5659 	if (!journal_inode->i_nlink) {
5660 		make_bad_inode(journal_inode);
5661 		iput(journal_inode);
5662 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5663 		return NULL;
5664 	}
5665 
5666 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5667 		  journal_inode, journal_inode->i_size);
5668 	if (!S_ISREG(journal_inode->i_mode)) {
5669 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5670 		iput(journal_inode);
5671 		return NULL;
5672 	}
5673 	return journal_inode;
5674 }
5675 
5676 static journal_t *ext4_get_journal(struct super_block *sb,
5677 				   unsigned int journal_inum)
5678 {
5679 	struct inode *journal_inode;
5680 	journal_t *journal;
5681 
5682 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5683 		return NULL;
5684 
5685 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5686 	if (!journal_inode)
5687 		return NULL;
5688 
5689 	journal = jbd2_journal_init_inode(journal_inode);
5690 	if (!journal) {
5691 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5692 		iput(journal_inode);
5693 		return NULL;
5694 	}
5695 	journal->j_private = sb;
5696 	ext4_init_journal_params(sb, journal);
5697 	return journal;
5698 }
5699 
5700 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5701 				       dev_t j_dev)
5702 {
5703 	struct buffer_head *bh;
5704 	journal_t *journal;
5705 	ext4_fsblk_t start;
5706 	ext4_fsblk_t len;
5707 	int hblock, blocksize;
5708 	ext4_fsblk_t sb_block;
5709 	unsigned long offset;
5710 	struct ext4_super_block *es;
5711 	struct block_device *bdev;
5712 
5713 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5714 		return NULL;
5715 
5716 	bdev = ext4_blkdev_get(j_dev, sb);
5717 	if (bdev == NULL)
5718 		return NULL;
5719 
5720 	blocksize = sb->s_blocksize;
5721 	hblock = bdev_logical_block_size(bdev);
5722 	if (blocksize < hblock) {
5723 		ext4_msg(sb, KERN_ERR,
5724 			"blocksize too small for journal device");
5725 		goto out_bdev;
5726 	}
5727 
5728 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5729 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5730 	set_blocksize(bdev, blocksize);
5731 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5732 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5733 		       "external journal");
5734 		goto out_bdev;
5735 	}
5736 
5737 	es = (struct ext4_super_block *) (bh->b_data + offset);
5738 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5739 	    !(le32_to_cpu(es->s_feature_incompat) &
5740 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5741 		ext4_msg(sb, KERN_ERR, "external journal has "
5742 					"bad superblock");
5743 		brelse(bh);
5744 		goto out_bdev;
5745 	}
5746 
5747 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5748 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5749 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5750 		ext4_msg(sb, KERN_ERR, "external journal has "
5751 				       "corrupt superblock");
5752 		brelse(bh);
5753 		goto out_bdev;
5754 	}
5755 
5756 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5757 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5758 		brelse(bh);
5759 		goto out_bdev;
5760 	}
5761 
5762 	len = ext4_blocks_count(es);
5763 	start = sb_block + 1;
5764 	brelse(bh);	/* we're done with the superblock */
5765 
5766 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5767 					start, len, blocksize);
5768 	if (!journal) {
5769 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5770 		goto out_bdev;
5771 	}
5772 	journal->j_private = sb;
5773 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5774 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5775 		goto out_journal;
5776 	}
5777 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5778 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5779 					"user (unsupported) - %d",
5780 			be32_to_cpu(journal->j_superblock->s_nr_users));
5781 		goto out_journal;
5782 	}
5783 	EXT4_SB(sb)->s_journal_bdev = bdev;
5784 	ext4_init_journal_params(sb, journal);
5785 	return journal;
5786 
5787 out_journal:
5788 	jbd2_journal_destroy(journal);
5789 out_bdev:
5790 	ext4_blkdev_put(bdev);
5791 	return NULL;
5792 }
5793 
5794 static int ext4_load_journal(struct super_block *sb,
5795 			     struct ext4_super_block *es,
5796 			     unsigned long journal_devnum)
5797 {
5798 	journal_t *journal;
5799 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5800 	dev_t journal_dev;
5801 	int err = 0;
5802 	int really_read_only;
5803 	int journal_dev_ro;
5804 
5805 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5806 		return -EFSCORRUPTED;
5807 
5808 	if (journal_devnum &&
5809 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5810 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5811 			"numbers have changed");
5812 		journal_dev = new_decode_dev(journal_devnum);
5813 	} else
5814 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5815 
5816 	if (journal_inum && journal_dev) {
5817 		ext4_msg(sb, KERN_ERR,
5818 			 "filesystem has both journal inode and journal device!");
5819 		return -EINVAL;
5820 	}
5821 
5822 	if (journal_inum) {
5823 		journal = ext4_get_journal(sb, journal_inum);
5824 		if (!journal)
5825 			return -EINVAL;
5826 	} else {
5827 		journal = ext4_get_dev_journal(sb, journal_dev);
5828 		if (!journal)
5829 			return -EINVAL;
5830 	}
5831 
5832 	journal_dev_ro = bdev_read_only(journal->j_dev);
5833 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5834 
5835 	if (journal_dev_ro && !sb_rdonly(sb)) {
5836 		ext4_msg(sb, KERN_ERR,
5837 			 "journal device read-only, try mounting with '-o ro'");
5838 		err = -EROFS;
5839 		goto err_out;
5840 	}
5841 
5842 	/*
5843 	 * Are we loading a blank journal or performing recovery after a
5844 	 * crash?  For recovery, we need to check in advance whether we
5845 	 * can get read-write access to the device.
5846 	 */
5847 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5848 		if (sb_rdonly(sb)) {
5849 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5850 					"required on readonly filesystem");
5851 			if (really_read_only) {
5852 				ext4_msg(sb, KERN_ERR, "write access "
5853 					"unavailable, cannot proceed "
5854 					"(try mounting with noload)");
5855 				err = -EROFS;
5856 				goto err_out;
5857 			}
5858 			ext4_msg(sb, KERN_INFO, "write access will "
5859 			       "be enabled during recovery");
5860 		}
5861 	}
5862 
5863 	if (!(journal->j_flags & JBD2_BARRIER))
5864 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5865 
5866 	if (!ext4_has_feature_journal_needs_recovery(sb))
5867 		err = jbd2_journal_wipe(journal, !really_read_only);
5868 	if (!err) {
5869 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5870 		if (save)
5871 			memcpy(save, ((char *) es) +
5872 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5873 		err = jbd2_journal_load(journal);
5874 		if (save)
5875 			memcpy(((char *) es) + EXT4_S_ERR_START,
5876 			       save, EXT4_S_ERR_LEN);
5877 		kfree(save);
5878 	}
5879 
5880 	if (err) {
5881 		ext4_msg(sb, KERN_ERR, "error loading journal");
5882 		goto err_out;
5883 	}
5884 
5885 	EXT4_SB(sb)->s_journal = journal;
5886 	err = ext4_clear_journal_err(sb, es);
5887 	if (err) {
5888 		EXT4_SB(sb)->s_journal = NULL;
5889 		jbd2_journal_destroy(journal);
5890 		return err;
5891 	}
5892 
5893 	if (!really_read_only && journal_devnum &&
5894 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5895 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5896 
5897 		/* Make sure we flush the recovery flag to disk. */
5898 		ext4_commit_super(sb);
5899 	}
5900 
5901 	return 0;
5902 
5903 err_out:
5904 	jbd2_journal_destroy(journal);
5905 	return err;
5906 }
5907 
5908 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5909 static void ext4_update_super(struct super_block *sb)
5910 {
5911 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5912 	struct ext4_super_block *es = sbi->s_es;
5913 	struct buffer_head *sbh = sbi->s_sbh;
5914 
5915 	lock_buffer(sbh);
5916 	/*
5917 	 * If the file system is mounted read-only, don't update the
5918 	 * superblock write time.  This avoids updating the superblock
5919 	 * write time when we are mounting the root file system
5920 	 * read/only but we need to replay the journal; at that point,
5921 	 * for people who are east of GMT and who make their clock
5922 	 * tick in localtime for Windows bug-for-bug compatibility,
5923 	 * the clock is set in the future, and this will cause e2fsck
5924 	 * to complain and force a full file system check.
5925 	 */
5926 	if (!(sb->s_flags & SB_RDONLY))
5927 		ext4_update_tstamp(es, s_wtime);
5928 	es->s_kbytes_written =
5929 		cpu_to_le64(sbi->s_kbytes_written +
5930 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5931 		      sbi->s_sectors_written_start) >> 1));
5932 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5933 		ext4_free_blocks_count_set(es,
5934 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5935 				&sbi->s_freeclusters_counter)));
5936 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5937 		es->s_free_inodes_count =
5938 			cpu_to_le32(percpu_counter_sum_positive(
5939 				&sbi->s_freeinodes_counter));
5940 	/* Copy error information to the on-disk superblock */
5941 	spin_lock(&sbi->s_error_lock);
5942 	if (sbi->s_add_error_count > 0) {
5943 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5944 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5945 			__ext4_update_tstamp(&es->s_first_error_time,
5946 					     &es->s_first_error_time_hi,
5947 					     sbi->s_first_error_time);
5948 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5949 				sizeof(es->s_first_error_func));
5950 			es->s_first_error_line =
5951 				cpu_to_le32(sbi->s_first_error_line);
5952 			es->s_first_error_ino =
5953 				cpu_to_le32(sbi->s_first_error_ino);
5954 			es->s_first_error_block =
5955 				cpu_to_le64(sbi->s_first_error_block);
5956 			es->s_first_error_errcode =
5957 				ext4_errno_to_code(sbi->s_first_error_code);
5958 		}
5959 		__ext4_update_tstamp(&es->s_last_error_time,
5960 				     &es->s_last_error_time_hi,
5961 				     sbi->s_last_error_time);
5962 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5963 			sizeof(es->s_last_error_func));
5964 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5965 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5966 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5967 		es->s_last_error_errcode =
5968 				ext4_errno_to_code(sbi->s_last_error_code);
5969 		/*
5970 		 * Start the daily error reporting function if it hasn't been
5971 		 * started already
5972 		 */
5973 		if (!es->s_error_count)
5974 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5975 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5976 		sbi->s_add_error_count = 0;
5977 	}
5978 	spin_unlock(&sbi->s_error_lock);
5979 
5980 	ext4_superblock_csum_set(sb);
5981 	unlock_buffer(sbh);
5982 }
5983 
5984 static int ext4_commit_super(struct super_block *sb)
5985 {
5986 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5987 	int error = 0;
5988 
5989 	if (!sbh)
5990 		return -EINVAL;
5991 	if (block_device_ejected(sb))
5992 		return -ENODEV;
5993 
5994 	ext4_update_super(sb);
5995 
5996 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5997 		/*
5998 		 * Oh, dear.  A previous attempt to write the
5999 		 * superblock failed.  This could happen because the
6000 		 * USB device was yanked out.  Or it could happen to
6001 		 * be a transient write error and maybe the block will
6002 		 * be remapped.  Nothing we can do but to retry the
6003 		 * write and hope for the best.
6004 		 */
6005 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6006 		       "superblock detected");
6007 		clear_buffer_write_io_error(sbh);
6008 		set_buffer_uptodate(sbh);
6009 	}
6010 	BUFFER_TRACE(sbh, "marking dirty");
6011 	mark_buffer_dirty(sbh);
6012 	error = __sync_dirty_buffer(sbh,
6013 		REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
6014 	if (buffer_write_io_error(sbh)) {
6015 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6016 		       "superblock");
6017 		clear_buffer_write_io_error(sbh);
6018 		set_buffer_uptodate(sbh);
6019 	}
6020 	return error;
6021 }
6022 
6023 /*
6024  * Have we just finished recovery?  If so, and if we are mounting (or
6025  * remounting) the filesystem readonly, then we will end up with a
6026  * consistent fs on disk.  Record that fact.
6027  */
6028 static int ext4_mark_recovery_complete(struct super_block *sb,
6029 				       struct ext4_super_block *es)
6030 {
6031 	int err;
6032 	journal_t *journal = EXT4_SB(sb)->s_journal;
6033 
6034 	if (!ext4_has_feature_journal(sb)) {
6035 		if (journal != NULL) {
6036 			ext4_error(sb, "Journal got removed while the fs was "
6037 				   "mounted!");
6038 			return -EFSCORRUPTED;
6039 		}
6040 		return 0;
6041 	}
6042 	jbd2_journal_lock_updates(journal);
6043 	err = jbd2_journal_flush(journal, 0);
6044 	if (err < 0)
6045 		goto out;
6046 
6047 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6048 	    ext4_has_feature_orphan_present(sb))) {
6049 		if (!ext4_orphan_file_empty(sb)) {
6050 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6051 			err = -EFSCORRUPTED;
6052 			goto out;
6053 		}
6054 		ext4_clear_feature_journal_needs_recovery(sb);
6055 		ext4_clear_feature_orphan_present(sb);
6056 		ext4_commit_super(sb);
6057 	}
6058 out:
6059 	jbd2_journal_unlock_updates(journal);
6060 	return err;
6061 }
6062 
6063 /*
6064  * If we are mounting (or read-write remounting) a filesystem whose journal
6065  * has recorded an error from a previous lifetime, move that error to the
6066  * main filesystem now.
6067  */
6068 static int ext4_clear_journal_err(struct super_block *sb,
6069 				   struct ext4_super_block *es)
6070 {
6071 	journal_t *journal;
6072 	int j_errno;
6073 	const char *errstr;
6074 
6075 	if (!ext4_has_feature_journal(sb)) {
6076 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6077 		return -EFSCORRUPTED;
6078 	}
6079 
6080 	journal = EXT4_SB(sb)->s_journal;
6081 
6082 	/*
6083 	 * Now check for any error status which may have been recorded in the
6084 	 * journal by a prior ext4_error() or ext4_abort()
6085 	 */
6086 
6087 	j_errno = jbd2_journal_errno(journal);
6088 	if (j_errno) {
6089 		char nbuf[16];
6090 
6091 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6092 		ext4_warning(sb, "Filesystem error recorded "
6093 			     "from previous mount: %s", errstr);
6094 		ext4_warning(sb, "Marking fs in need of filesystem check.");
6095 
6096 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6097 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6098 		ext4_commit_super(sb);
6099 
6100 		jbd2_journal_clear_err(journal);
6101 		jbd2_journal_update_sb_errno(journal);
6102 	}
6103 	return 0;
6104 }
6105 
6106 /*
6107  * Force the running and committing transactions to commit,
6108  * and wait on the commit.
6109  */
6110 int ext4_force_commit(struct super_block *sb)
6111 {
6112 	journal_t *journal;
6113 
6114 	if (sb_rdonly(sb))
6115 		return 0;
6116 
6117 	journal = EXT4_SB(sb)->s_journal;
6118 	return ext4_journal_force_commit(journal);
6119 }
6120 
6121 static int ext4_sync_fs(struct super_block *sb, int wait)
6122 {
6123 	int ret = 0;
6124 	tid_t target;
6125 	bool needs_barrier = false;
6126 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6127 
6128 	if (unlikely(ext4_forced_shutdown(sbi)))
6129 		return 0;
6130 
6131 	trace_ext4_sync_fs(sb, wait);
6132 	flush_workqueue(sbi->rsv_conversion_wq);
6133 	/*
6134 	 * Writeback quota in non-journalled quota case - journalled quota has
6135 	 * no dirty dquots
6136 	 */
6137 	dquot_writeback_dquots(sb, -1);
6138 	/*
6139 	 * Data writeback is possible w/o journal transaction, so barrier must
6140 	 * being sent at the end of the function. But we can skip it if
6141 	 * transaction_commit will do it for us.
6142 	 */
6143 	if (sbi->s_journal) {
6144 		target = jbd2_get_latest_transaction(sbi->s_journal);
6145 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6146 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6147 			needs_barrier = true;
6148 
6149 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6150 			if (wait)
6151 				ret = jbd2_log_wait_commit(sbi->s_journal,
6152 							   target);
6153 		}
6154 	} else if (wait && test_opt(sb, BARRIER))
6155 		needs_barrier = true;
6156 	if (needs_barrier) {
6157 		int err;
6158 		err = blkdev_issue_flush(sb->s_bdev);
6159 		if (!ret)
6160 			ret = err;
6161 	}
6162 
6163 	return ret;
6164 }
6165 
6166 /*
6167  * LVM calls this function before a (read-only) snapshot is created.  This
6168  * gives us a chance to flush the journal completely and mark the fs clean.
6169  *
6170  * Note that only this function cannot bring a filesystem to be in a clean
6171  * state independently. It relies on upper layer to stop all data & metadata
6172  * modifications.
6173  */
6174 static int ext4_freeze(struct super_block *sb)
6175 {
6176 	int error = 0;
6177 	journal_t *journal;
6178 
6179 	if (sb_rdonly(sb))
6180 		return 0;
6181 
6182 	journal = EXT4_SB(sb)->s_journal;
6183 
6184 	if (journal) {
6185 		/* Now we set up the journal barrier. */
6186 		jbd2_journal_lock_updates(journal);
6187 
6188 		/*
6189 		 * Don't clear the needs_recovery flag if we failed to
6190 		 * flush the journal.
6191 		 */
6192 		error = jbd2_journal_flush(journal, 0);
6193 		if (error < 0)
6194 			goto out;
6195 
6196 		/* Journal blocked and flushed, clear needs_recovery flag. */
6197 		ext4_clear_feature_journal_needs_recovery(sb);
6198 		if (ext4_orphan_file_empty(sb))
6199 			ext4_clear_feature_orphan_present(sb);
6200 	}
6201 
6202 	error = ext4_commit_super(sb);
6203 out:
6204 	if (journal)
6205 		/* we rely on upper layer to stop further updates */
6206 		jbd2_journal_unlock_updates(journal);
6207 	return error;
6208 }
6209 
6210 /*
6211  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6212  * flag here, even though the filesystem is not technically dirty yet.
6213  */
6214 static int ext4_unfreeze(struct super_block *sb)
6215 {
6216 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6217 		return 0;
6218 
6219 	if (EXT4_SB(sb)->s_journal) {
6220 		/* Reset the needs_recovery flag before the fs is unlocked. */
6221 		ext4_set_feature_journal_needs_recovery(sb);
6222 		if (ext4_has_feature_orphan_file(sb))
6223 			ext4_set_feature_orphan_present(sb);
6224 	}
6225 
6226 	ext4_commit_super(sb);
6227 	return 0;
6228 }
6229 
6230 /*
6231  * Structure to save mount options for ext4_remount's benefit
6232  */
6233 struct ext4_mount_options {
6234 	unsigned long s_mount_opt;
6235 	unsigned long s_mount_opt2;
6236 	kuid_t s_resuid;
6237 	kgid_t s_resgid;
6238 	unsigned long s_commit_interval;
6239 	u32 s_min_batch_time, s_max_batch_time;
6240 #ifdef CONFIG_QUOTA
6241 	int s_jquota_fmt;
6242 	char *s_qf_names[EXT4_MAXQUOTAS];
6243 #endif
6244 };
6245 
6246 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6247 {
6248 	struct ext4_fs_context *ctx = fc->fs_private;
6249 	struct ext4_super_block *es;
6250 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6251 	unsigned long old_sb_flags;
6252 	struct ext4_mount_options old_opts;
6253 	ext4_group_t g;
6254 	int err = 0;
6255 #ifdef CONFIG_QUOTA
6256 	int enable_quota = 0;
6257 	int i, j;
6258 	char *to_free[EXT4_MAXQUOTAS];
6259 #endif
6260 
6261 	ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6262 
6263 	/* Store the original options */
6264 	old_sb_flags = sb->s_flags;
6265 	old_opts.s_mount_opt = sbi->s_mount_opt;
6266 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6267 	old_opts.s_resuid = sbi->s_resuid;
6268 	old_opts.s_resgid = sbi->s_resgid;
6269 	old_opts.s_commit_interval = sbi->s_commit_interval;
6270 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6271 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6272 #ifdef CONFIG_QUOTA
6273 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6274 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6275 		if (sbi->s_qf_names[i]) {
6276 			char *qf_name = get_qf_name(sb, sbi, i);
6277 
6278 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6279 			if (!old_opts.s_qf_names[i]) {
6280 				for (j = 0; j < i; j++)
6281 					kfree(old_opts.s_qf_names[j]);
6282 				return -ENOMEM;
6283 			}
6284 		} else
6285 			old_opts.s_qf_names[i] = NULL;
6286 #endif
6287 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6288 		ctx->journal_ioprio =
6289 			sbi->s_journal->j_task->io_context->ioprio;
6290 
6291 	ext4_apply_options(fc, sb);
6292 
6293 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6294 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6295 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6296 			 "during remount not supported; ignoring");
6297 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6298 	}
6299 
6300 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6301 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6302 			ext4_msg(sb, KERN_ERR, "can't mount with "
6303 				 "both data=journal and delalloc");
6304 			err = -EINVAL;
6305 			goto restore_opts;
6306 		}
6307 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6308 			ext4_msg(sb, KERN_ERR, "can't mount with "
6309 				 "both data=journal and dioread_nolock");
6310 			err = -EINVAL;
6311 			goto restore_opts;
6312 		}
6313 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6314 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6315 			ext4_msg(sb, KERN_ERR, "can't mount with "
6316 				"journal_async_commit in data=ordered mode");
6317 			err = -EINVAL;
6318 			goto restore_opts;
6319 		}
6320 	}
6321 
6322 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6323 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6324 		err = -EINVAL;
6325 		goto restore_opts;
6326 	}
6327 
6328 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6329 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6330 
6331 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6332 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6333 
6334 	es = sbi->s_es;
6335 
6336 	if (sbi->s_journal) {
6337 		ext4_init_journal_params(sb, sbi->s_journal);
6338 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6339 	}
6340 
6341 	/* Flush outstanding errors before changing fs state */
6342 	flush_work(&sbi->s_error_work);
6343 
6344 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6345 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6346 			err = -EROFS;
6347 			goto restore_opts;
6348 		}
6349 
6350 		if (fc->sb_flags & SB_RDONLY) {
6351 			err = sync_filesystem(sb);
6352 			if (err < 0)
6353 				goto restore_opts;
6354 			err = dquot_suspend(sb, -1);
6355 			if (err < 0)
6356 				goto restore_opts;
6357 
6358 			/*
6359 			 * First of all, the unconditional stuff we have to do
6360 			 * to disable replay of the journal when we next remount
6361 			 */
6362 			sb->s_flags |= SB_RDONLY;
6363 
6364 			/*
6365 			 * OK, test if we are remounting a valid rw partition
6366 			 * readonly, and if so set the rdonly flag and then
6367 			 * mark the partition as valid again.
6368 			 */
6369 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6370 			    (sbi->s_mount_state & EXT4_VALID_FS))
6371 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6372 
6373 			if (sbi->s_journal) {
6374 				/*
6375 				 * We let remount-ro finish even if marking fs
6376 				 * as clean failed...
6377 				 */
6378 				ext4_mark_recovery_complete(sb, es);
6379 			}
6380 		} else {
6381 			/* Make sure we can mount this feature set readwrite */
6382 			if (ext4_has_feature_readonly(sb) ||
6383 			    !ext4_feature_set_ok(sb, 0)) {
6384 				err = -EROFS;
6385 				goto restore_opts;
6386 			}
6387 			/*
6388 			 * Make sure the group descriptor checksums
6389 			 * are sane.  If they aren't, refuse to remount r/w.
6390 			 */
6391 			for (g = 0; g < sbi->s_groups_count; g++) {
6392 				struct ext4_group_desc *gdp =
6393 					ext4_get_group_desc(sb, g, NULL);
6394 
6395 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6396 					ext4_msg(sb, KERN_ERR,
6397 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6398 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6399 					       le16_to_cpu(gdp->bg_checksum));
6400 					err = -EFSBADCRC;
6401 					goto restore_opts;
6402 				}
6403 			}
6404 
6405 			/*
6406 			 * If we have an unprocessed orphan list hanging
6407 			 * around from a previously readonly bdev mount,
6408 			 * require a full umount/remount for now.
6409 			 */
6410 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6411 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6412 				       "remount RDWR because of unprocessed "
6413 				       "orphan inode list.  Please "
6414 				       "umount/remount instead");
6415 				err = -EINVAL;
6416 				goto restore_opts;
6417 			}
6418 
6419 			/*
6420 			 * Mounting a RDONLY partition read-write, so reread
6421 			 * and store the current valid flag.  (It may have
6422 			 * been changed by e2fsck since we originally mounted
6423 			 * the partition.)
6424 			 */
6425 			if (sbi->s_journal) {
6426 				err = ext4_clear_journal_err(sb, es);
6427 				if (err)
6428 					goto restore_opts;
6429 			}
6430 			sbi->s_mount_state = le16_to_cpu(es->s_state);
6431 
6432 			err = ext4_setup_super(sb, es, 0);
6433 			if (err)
6434 				goto restore_opts;
6435 
6436 			sb->s_flags &= ~SB_RDONLY;
6437 			if (ext4_has_feature_mmp(sb))
6438 				if (ext4_multi_mount_protect(sb,
6439 						le64_to_cpu(es->s_mmp_block))) {
6440 					err = -EROFS;
6441 					goto restore_opts;
6442 				}
6443 #ifdef CONFIG_QUOTA
6444 			enable_quota = 1;
6445 #endif
6446 		}
6447 	}
6448 
6449 	/*
6450 	 * Reinitialize lazy itable initialization thread based on
6451 	 * current settings
6452 	 */
6453 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6454 		ext4_unregister_li_request(sb);
6455 	else {
6456 		ext4_group_t first_not_zeroed;
6457 		first_not_zeroed = ext4_has_uninit_itable(sb);
6458 		ext4_register_li_request(sb, first_not_zeroed);
6459 	}
6460 
6461 	/*
6462 	 * Handle creation of system zone data early because it can fail.
6463 	 * Releasing of existing data is done when we are sure remount will
6464 	 * succeed.
6465 	 */
6466 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6467 		err = ext4_setup_system_zone(sb);
6468 		if (err)
6469 			goto restore_opts;
6470 	}
6471 
6472 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6473 		err = ext4_commit_super(sb);
6474 		if (err)
6475 			goto restore_opts;
6476 	}
6477 
6478 #ifdef CONFIG_QUOTA
6479 	/* Release old quota file names */
6480 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6481 		kfree(old_opts.s_qf_names[i]);
6482 	if (enable_quota) {
6483 		if (sb_any_quota_suspended(sb))
6484 			dquot_resume(sb, -1);
6485 		else if (ext4_has_feature_quota(sb)) {
6486 			err = ext4_enable_quotas(sb);
6487 			if (err)
6488 				goto restore_opts;
6489 		}
6490 	}
6491 #endif
6492 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6493 		ext4_release_system_zone(sb);
6494 
6495 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6496 		ext4_stop_mmpd(sbi);
6497 
6498 	return 0;
6499 
6500 restore_opts:
6501 	sb->s_flags = old_sb_flags;
6502 	sbi->s_mount_opt = old_opts.s_mount_opt;
6503 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6504 	sbi->s_resuid = old_opts.s_resuid;
6505 	sbi->s_resgid = old_opts.s_resgid;
6506 	sbi->s_commit_interval = old_opts.s_commit_interval;
6507 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6508 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6509 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6510 		ext4_release_system_zone(sb);
6511 #ifdef CONFIG_QUOTA
6512 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6513 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6514 		to_free[i] = get_qf_name(sb, sbi, i);
6515 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6516 	}
6517 	synchronize_rcu();
6518 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6519 		kfree(to_free[i]);
6520 #endif
6521 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6522 		ext4_stop_mmpd(sbi);
6523 	return err;
6524 }
6525 
6526 static int ext4_reconfigure(struct fs_context *fc)
6527 {
6528 	struct super_block *sb = fc->root->d_sb;
6529 	int ret;
6530 
6531 	fc->s_fs_info = EXT4_SB(sb);
6532 
6533 	ret = ext4_check_opt_consistency(fc, sb);
6534 	if (ret < 0)
6535 		return ret;
6536 
6537 	ret = __ext4_remount(fc, sb);
6538 	if (ret < 0)
6539 		return ret;
6540 
6541 	ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6542 		 ext4_quota_mode(sb));
6543 
6544 	return 0;
6545 }
6546 
6547 #ifdef CONFIG_QUOTA
6548 static int ext4_statfs_project(struct super_block *sb,
6549 			       kprojid_t projid, struct kstatfs *buf)
6550 {
6551 	struct kqid qid;
6552 	struct dquot *dquot;
6553 	u64 limit;
6554 	u64 curblock;
6555 
6556 	qid = make_kqid_projid(projid);
6557 	dquot = dqget(sb, qid);
6558 	if (IS_ERR(dquot))
6559 		return PTR_ERR(dquot);
6560 	spin_lock(&dquot->dq_dqb_lock);
6561 
6562 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6563 			     dquot->dq_dqb.dqb_bhardlimit);
6564 	limit >>= sb->s_blocksize_bits;
6565 
6566 	if (limit && buf->f_blocks > limit) {
6567 		curblock = (dquot->dq_dqb.dqb_curspace +
6568 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6569 		buf->f_blocks = limit;
6570 		buf->f_bfree = buf->f_bavail =
6571 			(buf->f_blocks > curblock) ?
6572 			 (buf->f_blocks - curblock) : 0;
6573 	}
6574 
6575 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6576 			     dquot->dq_dqb.dqb_ihardlimit);
6577 	if (limit && buf->f_files > limit) {
6578 		buf->f_files = limit;
6579 		buf->f_ffree =
6580 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6581 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6582 	}
6583 
6584 	spin_unlock(&dquot->dq_dqb_lock);
6585 	dqput(dquot);
6586 	return 0;
6587 }
6588 #endif
6589 
6590 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6591 {
6592 	struct super_block *sb = dentry->d_sb;
6593 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6594 	struct ext4_super_block *es = sbi->s_es;
6595 	ext4_fsblk_t overhead = 0, resv_blocks;
6596 	s64 bfree;
6597 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6598 
6599 	if (!test_opt(sb, MINIX_DF))
6600 		overhead = sbi->s_overhead;
6601 
6602 	buf->f_type = EXT4_SUPER_MAGIC;
6603 	buf->f_bsize = sb->s_blocksize;
6604 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6605 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6606 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6607 	/* prevent underflow in case that few free space is available */
6608 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6609 	buf->f_bavail = buf->f_bfree -
6610 			(ext4_r_blocks_count(es) + resv_blocks);
6611 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6612 		buf->f_bavail = 0;
6613 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6614 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6615 	buf->f_namelen = EXT4_NAME_LEN;
6616 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6617 
6618 #ifdef CONFIG_QUOTA
6619 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6620 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6621 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6622 #endif
6623 	return 0;
6624 }
6625 
6626 
6627 #ifdef CONFIG_QUOTA
6628 
6629 /*
6630  * Helper functions so that transaction is started before we acquire dqio_sem
6631  * to keep correct lock ordering of transaction > dqio_sem
6632  */
6633 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6634 {
6635 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6636 }
6637 
6638 static int ext4_write_dquot(struct dquot *dquot)
6639 {
6640 	int ret, err;
6641 	handle_t *handle;
6642 	struct inode *inode;
6643 
6644 	inode = dquot_to_inode(dquot);
6645 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6646 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6647 	if (IS_ERR(handle))
6648 		return PTR_ERR(handle);
6649 	ret = dquot_commit(dquot);
6650 	err = ext4_journal_stop(handle);
6651 	if (!ret)
6652 		ret = err;
6653 	return ret;
6654 }
6655 
6656 static int ext4_acquire_dquot(struct dquot *dquot)
6657 {
6658 	int ret, err;
6659 	handle_t *handle;
6660 
6661 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6662 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6663 	if (IS_ERR(handle))
6664 		return PTR_ERR(handle);
6665 	ret = dquot_acquire(dquot);
6666 	err = ext4_journal_stop(handle);
6667 	if (!ret)
6668 		ret = err;
6669 	return ret;
6670 }
6671 
6672 static int ext4_release_dquot(struct dquot *dquot)
6673 {
6674 	int ret, err;
6675 	handle_t *handle;
6676 
6677 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6678 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6679 	if (IS_ERR(handle)) {
6680 		/* Release dquot anyway to avoid endless cycle in dqput() */
6681 		dquot_release(dquot);
6682 		return PTR_ERR(handle);
6683 	}
6684 	ret = dquot_release(dquot);
6685 	err = ext4_journal_stop(handle);
6686 	if (!ret)
6687 		ret = err;
6688 	return ret;
6689 }
6690 
6691 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6692 {
6693 	struct super_block *sb = dquot->dq_sb;
6694 
6695 	if (ext4_is_quota_journalled(sb)) {
6696 		dquot_mark_dquot_dirty(dquot);
6697 		return ext4_write_dquot(dquot);
6698 	} else {
6699 		return dquot_mark_dquot_dirty(dquot);
6700 	}
6701 }
6702 
6703 static int ext4_write_info(struct super_block *sb, int type)
6704 {
6705 	int ret, err;
6706 	handle_t *handle;
6707 
6708 	/* Data block + inode block */
6709 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6710 	if (IS_ERR(handle))
6711 		return PTR_ERR(handle);
6712 	ret = dquot_commit_info(sb, type);
6713 	err = ext4_journal_stop(handle);
6714 	if (!ret)
6715 		ret = err;
6716 	return ret;
6717 }
6718 
6719 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6720 {
6721 	struct ext4_inode_info *ei = EXT4_I(inode);
6722 
6723 	/* The first argument of lockdep_set_subclass has to be
6724 	 * *exactly* the same as the argument to init_rwsem() --- in
6725 	 * this case, in init_once() --- or lockdep gets unhappy
6726 	 * because the name of the lock is set using the
6727 	 * stringification of the argument to init_rwsem().
6728 	 */
6729 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6730 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6731 }
6732 
6733 /*
6734  * Standard function to be called on quota_on
6735  */
6736 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6737 			 const struct path *path)
6738 {
6739 	int err;
6740 
6741 	if (!test_opt(sb, QUOTA))
6742 		return -EINVAL;
6743 
6744 	/* Quotafile not on the same filesystem? */
6745 	if (path->dentry->d_sb != sb)
6746 		return -EXDEV;
6747 
6748 	/* Quota already enabled for this file? */
6749 	if (IS_NOQUOTA(d_inode(path->dentry)))
6750 		return -EBUSY;
6751 
6752 	/* Journaling quota? */
6753 	if (EXT4_SB(sb)->s_qf_names[type]) {
6754 		/* Quotafile not in fs root? */
6755 		if (path->dentry->d_parent != sb->s_root)
6756 			ext4_msg(sb, KERN_WARNING,
6757 				"Quota file not on filesystem root. "
6758 				"Journaled quota will not work");
6759 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6760 	} else {
6761 		/*
6762 		 * Clear the flag just in case mount options changed since
6763 		 * last time.
6764 		 */
6765 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6766 	}
6767 
6768 	/*
6769 	 * When we journal data on quota file, we have to flush journal to see
6770 	 * all updates to the file when we bypass pagecache...
6771 	 */
6772 	if (EXT4_SB(sb)->s_journal &&
6773 	    ext4_should_journal_data(d_inode(path->dentry))) {
6774 		/*
6775 		 * We don't need to lock updates but journal_flush() could
6776 		 * otherwise be livelocked...
6777 		 */
6778 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6779 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6780 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6781 		if (err)
6782 			return err;
6783 	}
6784 
6785 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6786 	err = dquot_quota_on(sb, type, format_id, path);
6787 	if (!err) {
6788 		struct inode *inode = d_inode(path->dentry);
6789 		handle_t *handle;
6790 
6791 		/*
6792 		 * Set inode flags to prevent userspace from messing with quota
6793 		 * files. If this fails, we return success anyway since quotas
6794 		 * are already enabled and this is not a hard failure.
6795 		 */
6796 		inode_lock(inode);
6797 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6798 		if (IS_ERR(handle))
6799 			goto unlock_inode;
6800 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6801 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6802 				S_NOATIME | S_IMMUTABLE);
6803 		err = ext4_mark_inode_dirty(handle, inode);
6804 		ext4_journal_stop(handle);
6805 	unlock_inode:
6806 		inode_unlock(inode);
6807 		if (err)
6808 			dquot_quota_off(sb, type);
6809 	}
6810 	if (err)
6811 		lockdep_set_quota_inode(path->dentry->d_inode,
6812 					     I_DATA_SEM_NORMAL);
6813 	return err;
6814 }
6815 
6816 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6817 			     unsigned int flags)
6818 {
6819 	int err;
6820 	struct inode *qf_inode;
6821 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6822 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6823 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6824 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6825 	};
6826 
6827 	BUG_ON(!ext4_has_feature_quota(sb));
6828 
6829 	if (!qf_inums[type])
6830 		return -EPERM;
6831 
6832 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6833 	if (IS_ERR(qf_inode)) {
6834 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6835 		return PTR_ERR(qf_inode);
6836 	}
6837 
6838 	/* Don't account quota for quota files to avoid recursion */
6839 	qf_inode->i_flags |= S_NOQUOTA;
6840 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6841 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6842 	if (err)
6843 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6844 	iput(qf_inode);
6845 
6846 	return err;
6847 }
6848 
6849 /* Enable usage tracking for all quota types. */
6850 int ext4_enable_quotas(struct super_block *sb)
6851 {
6852 	int type, err = 0;
6853 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6854 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6855 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6856 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6857 	};
6858 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6859 		test_opt(sb, USRQUOTA),
6860 		test_opt(sb, GRPQUOTA),
6861 		test_opt(sb, PRJQUOTA),
6862 	};
6863 
6864 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6865 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6866 		if (qf_inums[type]) {
6867 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6868 				DQUOT_USAGE_ENABLED |
6869 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6870 			if (err) {
6871 				ext4_warning(sb,
6872 					"Failed to enable quota tracking "
6873 					"(type=%d, err=%d). Please run "
6874 					"e2fsck to fix.", type, err);
6875 				for (type--; type >= 0; type--) {
6876 					struct inode *inode;
6877 
6878 					inode = sb_dqopt(sb)->files[type];
6879 					if (inode)
6880 						inode = igrab(inode);
6881 					dquot_quota_off(sb, type);
6882 					if (inode) {
6883 						lockdep_set_quota_inode(inode,
6884 							I_DATA_SEM_NORMAL);
6885 						iput(inode);
6886 					}
6887 				}
6888 
6889 				return err;
6890 			}
6891 		}
6892 	}
6893 	return 0;
6894 }
6895 
6896 static int ext4_quota_off(struct super_block *sb, int type)
6897 {
6898 	struct inode *inode = sb_dqopt(sb)->files[type];
6899 	handle_t *handle;
6900 	int err;
6901 
6902 	/* Force all delayed allocation blocks to be allocated.
6903 	 * Caller already holds s_umount sem */
6904 	if (test_opt(sb, DELALLOC))
6905 		sync_filesystem(sb);
6906 
6907 	if (!inode || !igrab(inode))
6908 		goto out;
6909 
6910 	err = dquot_quota_off(sb, type);
6911 	if (err || ext4_has_feature_quota(sb))
6912 		goto out_put;
6913 
6914 	inode_lock(inode);
6915 	/*
6916 	 * Update modification times of quota files when userspace can
6917 	 * start looking at them. If we fail, we return success anyway since
6918 	 * this is not a hard failure and quotas are already disabled.
6919 	 */
6920 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6921 	if (IS_ERR(handle)) {
6922 		err = PTR_ERR(handle);
6923 		goto out_unlock;
6924 	}
6925 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6926 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6927 	inode->i_mtime = inode->i_ctime = current_time(inode);
6928 	err = ext4_mark_inode_dirty(handle, inode);
6929 	ext4_journal_stop(handle);
6930 out_unlock:
6931 	inode_unlock(inode);
6932 out_put:
6933 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6934 	iput(inode);
6935 	return err;
6936 out:
6937 	return dquot_quota_off(sb, type);
6938 }
6939 
6940 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6941  * acquiring the locks... As quota files are never truncated and quota code
6942  * itself serializes the operations (and no one else should touch the files)
6943  * we don't have to be afraid of races */
6944 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6945 			       size_t len, loff_t off)
6946 {
6947 	struct inode *inode = sb_dqopt(sb)->files[type];
6948 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6949 	int offset = off & (sb->s_blocksize - 1);
6950 	int tocopy;
6951 	size_t toread;
6952 	struct buffer_head *bh;
6953 	loff_t i_size = i_size_read(inode);
6954 
6955 	if (off > i_size)
6956 		return 0;
6957 	if (off+len > i_size)
6958 		len = i_size-off;
6959 	toread = len;
6960 	while (toread > 0) {
6961 		tocopy = sb->s_blocksize - offset < toread ?
6962 				sb->s_blocksize - offset : toread;
6963 		bh = ext4_bread(NULL, inode, blk, 0);
6964 		if (IS_ERR(bh))
6965 			return PTR_ERR(bh);
6966 		if (!bh)	/* A hole? */
6967 			memset(data, 0, tocopy);
6968 		else
6969 			memcpy(data, bh->b_data+offset, tocopy);
6970 		brelse(bh);
6971 		offset = 0;
6972 		toread -= tocopy;
6973 		data += tocopy;
6974 		blk++;
6975 	}
6976 	return len;
6977 }
6978 
6979 /* Write to quotafile (we know the transaction is already started and has
6980  * enough credits) */
6981 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6982 				const char *data, size_t len, loff_t off)
6983 {
6984 	struct inode *inode = sb_dqopt(sb)->files[type];
6985 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6986 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6987 	int retries = 0;
6988 	struct buffer_head *bh;
6989 	handle_t *handle = journal_current_handle();
6990 
6991 	if (!handle) {
6992 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6993 			" cancelled because transaction is not started",
6994 			(unsigned long long)off, (unsigned long long)len);
6995 		return -EIO;
6996 	}
6997 	/*
6998 	 * Since we account only one data block in transaction credits,
6999 	 * then it is impossible to cross a block boundary.
7000 	 */
7001 	if (sb->s_blocksize - offset < len) {
7002 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7003 			" cancelled because not block aligned",
7004 			(unsigned long long)off, (unsigned long long)len);
7005 		return -EIO;
7006 	}
7007 
7008 	do {
7009 		bh = ext4_bread(handle, inode, blk,
7010 				EXT4_GET_BLOCKS_CREATE |
7011 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7012 	} while (PTR_ERR(bh) == -ENOSPC &&
7013 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7014 	if (IS_ERR(bh))
7015 		return PTR_ERR(bh);
7016 	if (!bh)
7017 		goto out;
7018 	BUFFER_TRACE(bh, "get write access");
7019 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7020 	if (err) {
7021 		brelse(bh);
7022 		return err;
7023 	}
7024 	lock_buffer(bh);
7025 	memcpy(bh->b_data+offset, data, len);
7026 	flush_dcache_page(bh->b_page);
7027 	unlock_buffer(bh);
7028 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7029 	brelse(bh);
7030 out:
7031 	if (inode->i_size < off + len) {
7032 		i_size_write(inode, off + len);
7033 		EXT4_I(inode)->i_disksize = inode->i_size;
7034 		err2 = ext4_mark_inode_dirty(handle, inode);
7035 		if (unlikely(err2 && !err))
7036 			err = err2;
7037 	}
7038 	return err ? err : len;
7039 }
7040 #endif
7041 
7042 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7043 static inline void register_as_ext2(void)
7044 {
7045 	int err = register_filesystem(&ext2_fs_type);
7046 	if (err)
7047 		printk(KERN_WARNING
7048 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7049 }
7050 
7051 static inline void unregister_as_ext2(void)
7052 {
7053 	unregister_filesystem(&ext2_fs_type);
7054 }
7055 
7056 static inline int ext2_feature_set_ok(struct super_block *sb)
7057 {
7058 	if (ext4_has_unknown_ext2_incompat_features(sb))
7059 		return 0;
7060 	if (sb_rdonly(sb))
7061 		return 1;
7062 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7063 		return 0;
7064 	return 1;
7065 }
7066 #else
7067 static inline void register_as_ext2(void) { }
7068 static inline void unregister_as_ext2(void) { }
7069 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7070 #endif
7071 
7072 static inline void register_as_ext3(void)
7073 {
7074 	int err = register_filesystem(&ext3_fs_type);
7075 	if (err)
7076 		printk(KERN_WARNING
7077 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7078 }
7079 
7080 static inline void unregister_as_ext3(void)
7081 {
7082 	unregister_filesystem(&ext3_fs_type);
7083 }
7084 
7085 static inline int ext3_feature_set_ok(struct super_block *sb)
7086 {
7087 	if (ext4_has_unknown_ext3_incompat_features(sb))
7088 		return 0;
7089 	if (!ext4_has_feature_journal(sb))
7090 		return 0;
7091 	if (sb_rdonly(sb))
7092 		return 1;
7093 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7094 		return 0;
7095 	return 1;
7096 }
7097 
7098 static struct file_system_type ext4_fs_type = {
7099 	.owner			= THIS_MODULE,
7100 	.name			= "ext4",
7101 	.init_fs_context	= ext4_init_fs_context,
7102 	.parameters		= ext4_param_specs,
7103 	.kill_sb		= kill_block_super,
7104 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7105 };
7106 MODULE_ALIAS_FS("ext4");
7107 
7108 /* Shared across all ext4 file systems */
7109 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7110 
7111 static int __init ext4_init_fs(void)
7112 {
7113 	int i, err;
7114 
7115 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7116 	ext4_li_info = NULL;
7117 
7118 	/* Build-time check for flags consistency */
7119 	ext4_check_flag_values();
7120 
7121 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7122 		init_waitqueue_head(&ext4__ioend_wq[i]);
7123 
7124 	err = ext4_init_es();
7125 	if (err)
7126 		return err;
7127 
7128 	err = ext4_init_pending();
7129 	if (err)
7130 		goto out7;
7131 
7132 	err = ext4_init_post_read_processing();
7133 	if (err)
7134 		goto out6;
7135 
7136 	err = ext4_init_pageio();
7137 	if (err)
7138 		goto out5;
7139 
7140 	err = ext4_init_system_zone();
7141 	if (err)
7142 		goto out4;
7143 
7144 	err = ext4_init_sysfs();
7145 	if (err)
7146 		goto out3;
7147 
7148 	err = ext4_init_mballoc();
7149 	if (err)
7150 		goto out2;
7151 	err = init_inodecache();
7152 	if (err)
7153 		goto out1;
7154 
7155 	err = ext4_fc_init_dentry_cache();
7156 	if (err)
7157 		goto out05;
7158 
7159 	register_as_ext3();
7160 	register_as_ext2();
7161 	err = register_filesystem(&ext4_fs_type);
7162 	if (err)
7163 		goto out;
7164 
7165 	return 0;
7166 out:
7167 	unregister_as_ext2();
7168 	unregister_as_ext3();
7169 	ext4_fc_destroy_dentry_cache();
7170 out05:
7171 	destroy_inodecache();
7172 out1:
7173 	ext4_exit_mballoc();
7174 out2:
7175 	ext4_exit_sysfs();
7176 out3:
7177 	ext4_exit_system_zone();
7178 out4:
7179 	ext4_exit_pageio();
7180 out5:
7181 	ext4_exit_post_read_processing();
7182 out6:
7183 	ext4_exit_pending();
7184 out7:
7185 	ext4_exit_es();
7186 
7187 	return err;
7188 }
7189 
7190 static void __exit ext4_exit_fs(void)
7191 {
7192 	ext4_destroy_lazyinit_thread();
7193 	unregister_as_ext2();
7194 	unregister_as_ext3();
7195 	unregister_filesystem(&ext4_fs_type);
7196 	ext4_fc_destroy_dentry_cache();
7197 	destroy_inodecache();
7198 	ext4_exit_mballoc();
7199 	ext4_exit_sysfs();
7200 	ext4_exit_system_zone();
7201 	ext4_exit_pageio();
7202 	ext4_exit_post_read_processing();
7203 	ext4_exit_es();
7204 	ext4_exit_pending();
7205 }
7206 
7207 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7208 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7209 MODULE_LICENSE("GPL");
7210 MODULE_SOFTDEP("pre: crc32c");
7211 module_init(ext4_init_fs)
7212 module_exit(ext4_exit_fs)
7213