xref: /linux/fs/ext4/super.c (revision 0542aac494a75f6d467109349e0266d7116e2b77)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= kill_block_super,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= kill_block_super,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ | op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
207 {
208 	lock_buffer(bh);
209 	if (!wait) {
210 		ext4_read_bh_nowait(bh, op_flags, NULL);
211 		return 0;
212 	}
213 	return ext4_read_bh(bh, op_flags, NULL);
214 }
215 
216 /*
217  * This works like __bread_gfp() except it uses ERR_PTR for error
218  * returns.  Currently with sb_bread it's impossible to distinguish
219  * between ENOMEM and EIO situations (since both result in a NULL
220  * return.
221  */
222 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
223 					       sector_t block,
224 					       blk_opf_t op_flags, gfp_t gfp)
225 {
226 	struct buffer_head *bh;
227 	int ret;
228 
229 	bh = sb_getblk_gfp(sb, block, gfp);
230 	if (bh == NULL)
231 		return ERR_PTR(-ENOMEM);
232 	if (ext4_buffer_uptodate(bh))
233 		return bh;
234 
235 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
236 	if (ret) {
237 		put_bh(bh);
238 		return ERR_PTR(ret);
239 	}
240 	return bh;
241 }
242 
243 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
244 				   blk_opf_t op_flags)
245 {
246 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
247 }
248 
249 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
250 					    sector_t block)
251 {
252 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
253 }
254 
255 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
256 {
257 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
258 
259 	if (likely(bh)) {
260 		if (trylock_buffer(bh))
261 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
262 		brelse(bh);
263 	}
264 }
265 
266 static int ext4_verify_csum_type(struct super_block *sb,
267 				 struct ext4_super_block *es)
268 {
269 	if (!ext4_has_feature_metadata_csum(sb))
270 		return 1;
271 
272 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
273 }
274 
275 __le32 ext4_superblock_csum(struct super_block *sb,
276 			    struct ext4_super_block *es)
277 {
278 	struct ext4_sb_info *sbi = EXT4_SB(sb);
279 	int offset = offsetof(struct ext4_super_block, s_checksum);
280 	__u32 csum;
281 
282 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
283 
284 	return cpu_to_le32(csum);
285 }
286 
287 static int ext4_superblock_csum_verify(struct super_block *sb,
288 				       struct ext4_super_block *es)
289 {
290 	if (!ext4_has_metadata_csum(sb))
291 		return 1;
292 
293 	return es->s_checksum == ext4_superblock_csum(sb, es);
294 }
295 
296 void ext4_superblock_csum_set(struct super_block *sb)
297 {
298 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
299 
300 	if (!ext4_has_metadata_csum(sb))
301 		return;
302 
303 	es->s_checksum = ext4_superblock_csum(sb, es);
304 }
305 
306 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
307 			       struct ext4_group_desc *bg)
308 {
309 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
310 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
311 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
312 }
313 
314 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
323 			      struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_table_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
328 }
329 
330 __u32 ext4_free_group_clusters(struct super_block *sb,
331 			       struct ext4_group_desc *bg)
332 {
333 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
336 }
337 
338 __u32 ext4_free_inodes_count(struct super_block *sb,
339 			      struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_used_dirs_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
352 }
353 
354 __u32 ext4_itable_unused_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_itable_unused_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
360 }
361 
362 void ext4_block_bitmap_set(struct super_block *sb,
363 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
364 {
365 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
366 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
367 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
368 }
369 
370 void ext4_inode_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_table_set(struct super_block *sb,
379 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_free_group_clusters_set(struct super_block *sb,
387 				  struct ext4_group_desc *bg, __u32 count)
388 {
389 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
392 }
393 
394 void ext4_free_inodes_set(struct super_block *sb,
395 			  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_used_dirs_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
408 }
409 
410 void ext4_itable_unused_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
416 }
417 
418 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
419 {
420 	now = clamp_val(now, 0, (1ull << 40) - 1);
421 
422 	*lo = cpu_to_le32(lower_32_bits(now));
423 	*hi = upper_32_bits(now);
424 }
425 
426 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
427 {
428 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
429 }
430 #define ext4_update_tstamp(es, tstamp) \
431 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
432 			     ktime_get_real_seconds())
433 #define ext4_get_tstamp(es, tstamp) \
434 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
435 
436 /*
437  * The del_gendisk() function uninitializes the disk-specific data
438  * structures, including the bdi structure, without telling anyone
439  * else.  Once this happens, any attempt to call mark_buffer_dirty()
440  * (for example, by ext4_commit_super), will cause a kernel OOPS.
441  * This is a kludge to prevent these oops until we can put in a proper
442  * hook in del_gendisk() to inform the VFS and file system layers.
443  */
444 static int block_device_ejected(struct super_block *sb)
445 {
446 	struct inode *bd_inode = sb->s_bdev->bd_inode;
447 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
448 
449 	return bdi->dev == NULL;
450 }
451 
452 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
453 {
454 	struct super_block		*sb = journal->j_private;
455 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
456 	int				error = is_journal_aborted(journal);
457 	struct ext4_journal_cb_entry	*jce;
458 
459 	BUG_ON(txn->t_state == T_FINISHED);
460 
461 	ext4_process_freed_data(sb, txn->t_tid);
462 
463 	spin_lock(&sbi->s_md_lock);
464 	while (!list_empty(&txn->t_private_list)) {
465 		jce = list_entry(txn->t_private_list.next,
466 				 struct ext4_journal_cb_entry, jce_list);
467 		list_del_init(&jce->jce_list);
468 		spin_unlock(&sbi->s_md_lock);
469 		jce->jce_func(sb, jce, error);
470 		spin_lock(&sbi->s_md_lock);
471 	}
472 	spin_unlock(&sbi->s_md_lock);
473 }
474 
475 /*
476  * This writepage callback for write_cache_pages()
477  * takes care of a few cases after page cleaning.
478  *
479  * write_cache_pages() already checks for dirty pages
480  * and calls clear_page_dirty_for_io(), which we want,
481  * to write protect the pages.
482  *
483  * However, we may have to redirty a page (see below.)
484  */
485 static int ext4_journalled_writepage_callback(struct page *page,
486 					      struct writeback_control *wbc,
487 					      void *data)
488 {
489 	transaction_t *transaction = (transaction_t *) data;
490 	struct buffer_head *bh, *head;
491 	struct journal_head *jh;
492 
493 	bh = head = page_buffers(page);
494 	do {
495 		/*
496 		 * We have to redirty a page in these cases:
497 		 * 1) If buffer is dirty, it means the page was dirty because it
498 		 * contains a buffer that needs checkpointing. So the dirty bit
499 		 * needs to be preserved so that checkpointing writes the buffer
500 		 * properly.
501 		 * 2) If buffer is not part of the committing transaction
502 		 * (we may have just accidentally come across this buffer because
503 		 * inode range tracking is not exact) or if the currently running
504 		 * transaction already contains this buffer as well, dirty bit
505 		 * needs to be preserved so that the buffer gets writeprotected
506 		 * properly on running transaction's commit.
507 		 */
508 		jh = bh2jh(bh);
509 		if (buffer_dirty(bh) ||
510 		    (jh && (jh->b_transaction != transaction ||
511 			    jh->b_next_transaction))) {
512 			redirty_page_for_writepage(wbc, page);
513 			goto out;
514 		}
515 	} while ((bh = bh->b_this_page) != head);
516 
517 out:
518 	return AOP_WRITEPAGE_ACTIVATE;
519 }
520 
521 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
522 {
523 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
524 	struct writeback_control wbc = {
525 		.sync_mode =  WB_SYNC_ALL,
526 		.nr_to_write = LONG_MAX,
527 		.range_start = jinode->i_dirty_start,
528 		.range_end = jinode->i_dirty_end,
529         };
530 
531 	return write_cache_pages(mapping, &wbc,
532 				 ext4_journalled_writepage_callback,
533 				 jinode->i_transaction);
534 }
535 
536 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
537 {
538 	int ret;
539 
540 	if (ext4_should_journal_data(jinode->i_vfs_inode))
541 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
542 	else
543 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
544 
545 	return ret;
546 }
547 
548 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
549 {
550 	int ret = 0;
551 
552 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
553 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
554 
555 	return ret;
556 }
557 
558 static bool system_going_down(void)
559 {
560 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
561 		|| system_state == SYSTEM_RESTART;
562 }
563 
564 struct ext4_err_translation {
565 	int code;
566 	int errno;
567 };
568 
569 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
570 
571 static struct ext4_err_translation err_translation[] = {
572 	EXT4_ERR_TRANSLATE(EIO),
573 	EXT4_ERR_TRANSLATE(ENOMEM),
574 	EXT4_ERR_TRANSLATE(EFSBADCRC),
575 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
576 	EXT4_ERR_TRANSLATE(ENOSPC),
577 	EXT4_ERR_TRANSLATE(ENOKEY),
578 	EXT4_ERR_TRANSLATE(EROFS),
579 	EXT4_ERR_TRANSLATE(EFBIG),
580 	EXT4_ERR_TRANSLATE(EEXIST),
581 	EXT4_ERR_TRANSLATE(ERANGE),
582 	EXT4_ERR_TRANSLATE(EOVERFLOW),
583 	EXT4_ERR_TRANSLATE(EBUSY),
584 	EXT4_ERR_TRANSLATE(ENOTDIR),
585 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
586 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
587 	EXT4_ERR_TRANSLATE(EFAULT),
588 };
589 
590 static int ext4_errno_to_code(int errno)
591 {
592 	int i;
593 
594 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
595 		if (err_translation[i].errno == errno)
596 			return err_translation[i].code;
597 	return EXT4_ERR_UNKNOWN;
598 }
599 
600 static void save_error_info(struct super_block *sb, int error,
601 			    __u32 ino, __u64 block,
602 			    const char *func, unsigned int line)
603 {
604 	struct ext4_sb_info *sbi = EXT4_SB(sb);
605 
606 	/* We default to EFSCORRUPTED error... */
607 	if (error == 0)
608 		error = EFSCORRUPTED;
609 
610 	spin_lock(&sbi->s_error_lock);
611 	sbi->s_add_error_count++;
612 	sbi->s_last_error_code = error;
613 	sbi->s_last_error_line = line;
614 	sbi->s_last_error_ino = ino;
615 	sbi->s_last_error_block = block;
616 	sbi->s_last_error_func = func;
617 	sbi->s_last_error_time = ktime_get_real_seconds();
618 	if (!sbi->s_first_error_time) {
619 		sbi->s_first_error_code = error;
620 		sbi->s_first_error_line = line;
621 		sbi->s_first_error_ino = ino;
622 		sbi->s_first_error_block = block;
623 		sbi->s_first_error_func = func;
624 		sbi->s_first_error_time = sbi->s_last_error_time;
625 	}
626 	spin_unlock(&sbi->s_error_lock);
627 }
628 
629 /* Deal with the reporting of failure conditions on a filesystem such as
630  * inconsistencies detected or read IO failures.
631  *
632  * On ext2, we can store the error state of the filesystem in the
633  * superblock.  That is not possible on ext4, because we may have other
634  * write ordering constraints on the superblock which prevent us from
635  * writing it out straight away; and given that the journal is about to
636  * be aborted, we can't rely on the current, or future, transactions to
637  * write out the superblock safely.
638  *
639  * We'll just use the jbd2_journal_abort() error code to record an error in
640  * the journal instead.  On recovery, the journal will complain about
641  * that error until we've noted it down and cleared it.
642  *
643  * If force_ro is set, we unconditionally force the filesystem into an
644  * ABORT|READONLY state, unless the error response on the fs has been set to
645  * panic in which case we take the easy way out and panic immediately. This is
646  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
647  * at a critical moment in log management.
648  */
649 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
650 			      __u32 ino, __u64 block,
651 			      const char *func, unsigned int line)
652 {
653 	journal_t *journal = EXT4_SB(sb)->s_journal;
654 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
655 
656 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
657 	if (test_opt(sb, WARN_ON_ERROR))
658 		WARN_ON_ONCE(1);
659 
660 	if (!continue_fs && !sb_rdonly(sb)) {
661 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
662 		if (journal)
663 			jbd2_journal_abort(journal, -EIO);
664 	}
665 
666 	if (!bdev_read_only(sb->s_bdev)) {
667 		save_error_info(sb, error, ino, block, func, line);
668 		/*
669 		 * In case the fs should keep running, we need to writeout
670 		 * superblock through the journal. Due to lock ordering
671 		 * constraints, it may not be safe to do it right here so we
672 		 * defer superblock flushing to a workqueue.
673 		 */
674 		if (continue_fs && journal)
675 			schedule_work(&EXT4_SB(sb)->s_error_work);
676 		else
677 			ext4_commit_super(sb);
678 	}
679 
680 	/*
681 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
682 	 * could panic during 'reboot -f' as the underlying device got already
683 	 * disabled.
684 	 */
685 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
686 		panic("EXT4-fs (device %s): panic forced after error\n",
687 			sb->s_id);
688 	}
689 
690 	if (sb_rdonly(sb) || continue_fs)
691 		return;
692 
693 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
694 	/*
695 	 * Make sure updated value of ->s_mount_flags will be visible before
696 	 * ->s_flags update
697 	 */
698 	smp_wmb();
699 	sb->s_flags |= SB_RDONLY;
700 }
701 
702 static void flush_stashed_error_work(struct work_struct *work)
703 {
704 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
705 						s_error_work);
706 	journal_t *journal = sbi->s_journal;
707 	handle_t *handle;
708 
709 	/*
710 	 * If the journal is still running, we have to write out superblock
711 	 * through the journal to avoid collisions of other journalled sb
712 	 * updates.
713 	 *
714 	 * We use directly jbd2 functions here to avoid recursing back into
715 	 * ext4 error handling code during handling of previous errors.
716 	 */
717 	if (!sb_rdonly(sbi->s_sb) && journal) {
718 		struct buffer_head *sbh = sbi->s_sbh;
719 		handle = jbd2_journal_start(journal, 1);
720 		if (IS_ERR(handle))
721 			goto write_directly;
722 		if (jbd2_journal_get_write_access(handle, sbh)) {
723 			jbd2_journal_stop(handle);
724 			goto write_directly;
725 		}
726 		ext4_update_super(sbi->s_sb);
727 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
728 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
729 				 "superblock detected");
730 			clear_buffer_write_io_error(sbh);
731 			set_buffer_uptodate(sbh);
732 		}
733 
734 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
735 			jbd2_journal_stop(handle);
736 			goto write_directly;
737 		}
738 		jbd2_journal_stop(handle);
739 		ext4_notify_error_sysfs(sbi);
740 		return;
741 	}
742 write_directly:
743 	/*
744 	 * Write through journal failed. Write sb directly to get error info
745 	 * out and hope for the best.
746 	 */
747 	ext4_commit_super(sbi->s_sb);
748 	ext4_notify_error_sysfs(sbi);
749 }
750 
751 #define ext4_error_ratelimit(sb)					\
752 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
753 			     "EXT4-fs error")
754 
755 void __ext4_error(struct super_block *sb, const char *function,
756 		  unsigned int line, bool force_ro, int error, __u64 block,
757 		  const char *fmt, ...)
758 {
759 	struct va_format vaf;
760 	va_list args;
761 
762 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
763 		return;
764 
765 	trace_ext4_error(sb, function, line);
766 	if (ext4_error_ratelimit(sb)) {
767 		va_start(args, fmt);
768 		vaf.fmt = fmt;
769 		vaf.va = &args;
770 		printk(KERN_CRIT
771 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
772 		       sb->s_id, function, line, current->comm, &vaf);
773 		va_end(args);
774 	}
775 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
776 
777 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
778 }
779 
780 void __ext4_error_inode(struct inode *inode, const char *function,
781 			unsigned int line, ext4_fsblk_t block, int error,
782 			const char *fmt, ...)
783 {
784 	va_list args;
785 	struct va_format vaf;
786 
787 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
788 		return;
789 
790 	trace_ext4_error(inode->i_sb, function, line);
791 	if (ext4_error_ratelimit(inode->i_sb)) {
792 		va_start(args, fmt);
793 		vaf.fmt = fmt;
794 		vaf.va = &args;
795 		if (block)
796 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
797 			       "inode #%lu: block %llu: comm %s: %pV\n",
798 			       inode->i_sb->s_id, function, line, inode->i_ino,
799 			       block, current->comm, &vaf);
800 		else
801 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
802 			       "inode #%lu: comm %s: %pV\n",
803 			       inode->i_sb->s_id, function, line, inode->i_ino,
804 			       current->comm, &vaf);
805 		va_end(args);
806 	}
807 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
808 
809 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
810 			  function, line);
811 }
812 
813 void __ext4_error_file(struct file *file, const char *function,
814 		       unsigned int line, ext4_fsblk_t block,
815 		       const char *fmt, ...)
816 {
817 	va_list args;
818 	struct va_format vaf;
819 	struct inode *inode = file_inode(file);
820 	char pathname[80], *path;
821 
822 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
823 		return;
824 
825 	trace_ext4_error(inode->i_sb, function, line);
826 	if (ext4_error_ratelimit(inode->i_sb)) {
827 		path = file_path(file, pathname, sizeof(pathname));
828 		if (IS_ERR(path))
829 			path = "(unknown)";
830 		va_start(args, fmt);
831 		vaf.fmt = fmt;
832 		vaf.va = &args;
833 		if (block)
834 			printk(KERN_CRIT
835 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
836 			       "block %llu: comm %s: path %s: %pV\n",
837 			       inode->i_sb->s_id, function, line, inode->i_ino,
838 			       block, current->comm, path, &vaf);
839 		else
840 			printk(KERN_CRIT
841 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
842 			       "comm %s: path %s: %pV\n",
843 			       inode->i_sb->s_id, function, line, inode->i_ino,
844 			       current->comm, path, &vaf);
845 		va_end(args);
846 	}
847 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
848 
849 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
850 			  function, line);
851 }
852 
853 const char *ext4_decode_error(struct super_block *sb, int errno,
854 			      char nbuf[16])
855 {
856 	char *errstr = NULL;
857 
858 	switch (errno) {
859 	case -EFSCORRUPTED:
860 		errstr = "Corrupt filesystem";
861 		break;
862 	case -EFSBADCRC:
863 		errstr = "Filesystem failed CRC";
864 		break;
865 	case -EIO:
866 		errstr = "IO failure";
867 		break;
868 	case -ENOMEM:
869 		errstr = "Out of memory";
870 		break;
871 	case -EROFS:
872 		if (!sb || (EXT4_SB(sb)->s_journal &&
873 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
874 			errstr = "Journal has aborted";
875 		else
876 			errstr = "Readonly filesystem";
877 		break;
878 	default:
879 		/* If the caller passed in an extra buffer for unknown
880 		 * errors, textualise them now.  Else we just return
881 		 * NULL. */
882 		if (nbuf) {
883 			/* Check for truncated error codes... */
884 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
885 				errstr = nbuf;
886 		}
887 		break;
888 	}
889 
890 	return errstr;
891 }
892 
893 /* __ext4_std_error decodes expected errors from journaling functions
894  * automatically and invokes the appropriate error response.  */
895 
896 void __ext4_std_error(struct super_block *sb, const char *function,
897 		      unsigned int line, int errno)
898 {
899 	char nbuf[16];
900 	const char *errstr;
901 
902 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
903 		return;
904 
905 	/* Special case: if the error is EROFS, and we're not already
906 	 * inside a transaction, then there's really no point in logging
907 	 * an error. */
908 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
909 		return;
910 
911 	if (ext4_error_ratelimit(sb)) {
912 		errstr = ext4_decode_error(sb, errno, nbuf);
913 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
914 		       sb->s_id, function, line, errstr);
915 	}
916 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
917 
918 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
919 }
920 
921 void __ext4_msg(struct super_block *sb,
922 		const char *prefix, const char *fmt, ...)
923 {
924 	struct va_format vaf;
925 	va_list args;
926 
927 	if (sb) {
928 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
929 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
930 				  "EXT4-fs"))
931 			return;
932 	}
933 
934 	va_start(args, fmt);
935 	vaf.fmt = fmt;
936 	vaf.va = &args;
937 	if (sb)
938 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
939 	else
940 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
941 	va_end(args);
942 }
943 
944 static int ext4_warning_ratelimit(struct super_block *sb)
945 {
946 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
947 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
948 			    "EXT4-fs warning");
949 }
950 
951 void __ext4_warning(struct super_block *sb, const char *function,
952 		    unsigned int line, const char *fmt, ...)
953 {
954 	struct va_format vaf;
955 	va_list args;
956 
957 	if (!ext4_warning_ratelimit(sb))
958 		return;
959 
960 	va_start(args, fmt);
961 	vaf.fmt = fmt;
962 	vaf.va = &args;
963 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
964 	       sb->s_id, function, line, &vaf);
965 	va_end(args);
966 }
967 
968 void __ext4_warning_inode(const struct inode *inode, const char *function,
969 			  unsigned int line, const char *fmt, ...)
970 {
971 	struct va_format vaf;
972 	va_list args;
973 
974 	if (!ext4_warning_ratelimit(inode->i_sb))
975 		return;
976 
977 	va_start(args, fmt);
978 	vaf.fmt = fmt;
979 	vaf.va = &args;
980 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
981 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
982 	       function, line, inode->i_ino, current->comm, &vaf);
983 	va_end(args);
984 }
985 
986 void __ext4_grp_locked_error(const char *function, unsigned int line,
987 			     struct super_block *sb, ext4_group_t grp,
988 			     unsigned long ino, ext4_fsblk_t block,
989 			     const char *fmt, ...)
990 __releases(bitlock)
991 __acquires(bitlock)
992 {
993 	struct va_format vaf;
994 	va_list args;
995 
996 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
997 		return;
998 
999 	trace_ext4_error(sb, function, line);
1000 	if (ext4_error_ratelimit(sb)) {
1001 		va_start(args, fmt);
1002 		vaf.fmt = fmt;
1003 		vaf.va = &args;
1004 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1005 		       sb->s_id, function, line, grp);
1006 		if (ino)
1007 			printk(KERN_CONT "inode %lu: ", ino);
1008 		if (block)
1009 			printk(KERN_CONT "block %llu:",
1010 			       (unsigned long long) block);
1011 		printk(KERN_CONT "%pV\n", &vaf);
1012 		va_end(args);
1013 	}
1014 
1015 	if (test_opt(sb, ERRORS_CONT)) {
1016 		if (test_opt(sb, WARN_ON_ERROR))
1017 			WARN_ON_ONCE(1);
1018 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1019 		if (!bdev_read_only(sb->s_bdev)) {
1020 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1021 					line);
1022 			schedule_work(&EXT4_SB(sb)->s_error_work);
1023 		}
1024 		return;
1025 	}
1026 	ext4_unlock_group(sb, grp);
1027 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1028 	/*
1029 	 * We only get here in the ERRORS_RO case; relocking the group
1030 	 * may be dangerous, but nothing bad will happen since the
1031 	 * filesystem will have already been marked read/only and the
1032 	 * journal has been aborted.  We return 1 as a hint to callers
1033 	 * who might what to use the return value from
1034 	 * ext4_grp_locked_error() to distinguish between the
1035 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1036 	 * aggressively from the ext4 function in question, with a
1037 	 * more appropriate error code.
1038 	 */
1039 	ext4_lock_group(sb, grp);
1040 	return;
1041 }
1042 
1043 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1044 				     ext4_group_t group,
1045 				     unsigned int flags)
1046 {
1047 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1048 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1049 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1050 	int ret;
1051 
1052 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1053 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1054 					    &grp->bb_state);
1055 		if (!ret)
1056 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1057 					   grp->bb_free);
1058 	}
1059 
1060 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1061 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1062 					    &grp->bb_state);
1063 		if (!ret && gdp) {
1064 			int count;
1065 
1066 			count = ext4_free_inodes_count(sb, gdp);
1067 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1068 					   count);
1069 		}
1070 	}
1071 }
1072 
1073 void ext4_update_dynamic_rev(struct super_block *sb)
1074 {
1075 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1076 
1077 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1078 		return;
1079 
1080 	ext4_warning(sb,
1081 		     "updating to rev %d because of new feature flag, "
1082 		     "running e2fsck is recommended",
1083 		     EXT4_DYNAMIC_REV);
1084 
1085 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1086 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1087 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1088 	/* leave es->s_feature_*compat flags alone */
1089 	/* es->s_uuid will be set by e2fsck if empty */
1090 
1091 	/*
1092 	 * The rest of the superblock fields should be zero, and if not it
1093 	 * means they are likely already in use, so leave them alone.  We
1094 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1095 	 */
1096 }
1097 
1098 /*
1099  * Open the external journal device
1100  */
1101 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1102 {
1103 	struct block_device *bdev;
1104 
1105 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1106 	if (IS_ERR(bdev))
1107 		goto fail;
1108 	return bdev;
1109 
1110 fail:
1111 	ext4_msg(sb, KERN_ERR,
1112 		 "failed to open journal device unknown-block(%u,%u) %ld",
1113 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1114 	return NULL;
1115 }
1116 
1117 /*
1118  * Release the journal device
1119  */
1120 static void ext4_blkdev_put(struct block_device *bdev)
1121 {
1122 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1123 }
1124 
1125 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1126 {
1127 	struct block_device *bdev;
1128 	bdev = sbi->s_journal_bdev;
1129 	if (bdev) {
1130 		ext4_blkdev_put(bdev);
1131 		sbi->s_journal_bdev = NULL;
1132 	}
1133 }
1134 
1135 static inline struct inode *orphan_list_entry(struct list_head *l)
1136 {
1137 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1138 }
1139 
1140 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1141 {
1142 	struct list_head *l;
1143 
1144 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1145 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1146 
1147 	printk(KERN_ERR "sb_info orphan list:\n");
1148 	list_for_each(l, &sbi->s_orphan) {
1149 		struct inode *inode = orphan_list_entry(l);
1150 		printk(KERN_ERR "  "
1151 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1152 		       inode->i_sb->s_id, inode->i_ino, inode,
1153 		       inode->i_mode, inode->i_nlink,
1154 		       NEXT_ORPHAN(inode));
1155 	}
1156 }
1157 
1158 #ifdef CONFIG_QUOTA
1159 static int ext4_quota_off(struct super_block *sb, int type);
1160 
1161 static inline void ext4_quota_off_umount(struct super_block *sb)
1162 {
1163 	int type;
1164 
1165 	/* Use our quota_off function to clear inode flags etc. */
1166 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1167 		ext4_quota_off(sb, type);
1168 }
1169 
1170 /*
1171  * This is a helper function which is used in the mount/remount
1172  * codepaths (which holds s_umount) to fetch the quota file name.
1173  */
1174 static inline char *get_qf_name(struct super_block *sb,
1175 				struct ext4_sb_info *sbi,
1176 				int type)
1177 {
1178 	return rcu_dereference_protected(sbi->s_qf_names[type],
1179 					 lockdep_is_held(&sb->s_umount));
1180 }
1181 #else
1182 static inline void ext4_quota_off_umount(struct super_block *sb)
1183 {
1184 }
1185 #endif
1186 
1187 static void ext4_put_super(struct super_block *sb)
1188 {
1189 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1190 	struct ext4_super_block *es = sbi->s_es;
1191 	struct buffer_head **group_desc;
1192 	struct flex_groups **flex_groups;
1193 	int aborted = 0;
1194 	int i, err;
1195 
1196 	/*
1197 	 * Unregister sysfs before destroying jbd2 journal.
1198 	 * Since we could still access attr_journal_task attribute via sysfs
1199 	 * path which could have sbi->s_journal->j_task as NULL
1200 	 * Unregister sysfs before flush sbi->s_error_work.
1201 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1202 	 * read metadata verify failed then will queue error work.
1203 	 * flush_stashed_error_work will call start_this_handle may trigger
1204 	 * BUG_ON.
1205 	 */
1206 	ext4_unregister_sysfs(sb);
1207 
1208 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1209 		ext4_msg(sb, KERN_INFO, "unmounting filesystem.");
1210 
1211 	ext4_unregister_li_request(sb);
1212 	ext4_quota_off_umount(sb);
1213 
1214 	flush_work(&sbi->s_error_work);
1215 	destroy_workqueue(sbi->rsv_conversion_wq);
1216 	ext4_release_orphan_info(sb);
1217 
1218 	if (sbi->s_journal) {
1219 		aborted = is_journal_aborted(sbi->s_journal);
1220 		err = jbd2_journal_destroy(sbi->s_journal);
1221 		sbi->s_journal = NULL;
1222 		if ((err < 0) && !aborted) {
1223 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1224 		}
1225 	}
1226 
1227 	ext4_es_unregister_shrinker(sbi);
1228 	del_timer_sync(&sbi->s_err_report);
1229 	ext4_release_system_zone(sb);
1230 	ext4_mb_release(sb);
1231 	ext4_ext_release(sb);
1232 
1233 	if (!sb_rdonly(sb) && !aborted) {
1234 		ext4_clear_feature_journal_needs_recovery(sb);
1235 		ext4_clear_feature_orphan_present(sb);
1236 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1237 	}
1238 	if (!sb_rdonly(sb))
1239 		ext4_commit_super(sb);
1240 
1241 	rcu_read_lock();
1242 	group_desc = rcu_dereference(sbi->s_group_desc);
1243 	for (i = 0; i < sbi->s_gdb_count; i++)
1244 		brelse(group_desc[i]);
1245 	kvfree(group_desc);
1246 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1247 	if (flex_groups) {
1248 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1249 			kvfree(flex_groups[i]);
1250 		kvfree(flex_groups);
1251 	}
1252 	rcu_read_unlock();
1253 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1254 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1255 	percpu_counter_destroy(&sbi->s_dirs_counter);
1256 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1257 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1258 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1259 #ifdef CONFIG_QUOTA
1260 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1261 		kfree(get_qf_name(sb, sbi, i));
1262 #endif
1263 
1264 	/* Debugging code just in case the in-memory inode orphan list
1265 	 * isn't empty.  The on-disk one can be non-empty if we've
1266 	 * detected an error and taken the fs readonly, but the
1267 	 * in-memory list had better be clean by this point. */
1268 	if (!list_empty(&sbi->s_orphan))
1269 		dump_orphan_list(sb, sbi);
1270 	ASSERT(list_empty(&sbi->s_orphan));
1271 
1272 	sync_blockdev(sb->s_bdev);
1273 	invalidate_bdev(sb->s_bdev);
1274 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1275 		/*
1276 		 * Invalidate the journal device's buffers.  We don't want them
1277 		 * floating about in memory - the physical journal device may
1278 		 * hotswapped, and it breaks the `ro-after' testing code.
1279 		 */
1280 		sync_blockdev(sbi->s_journal_bdev);
1281 		invalidate_bdev(sbi->s_journal_bdev);
1282 		ext4_blkdev_remove(sbi);
1283 	}
1284 
1285 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1286 	sbi->s_ea_inode_cache = NULL;
1287 
1288 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1289 	sbi->s_ea_block_cache = NULL;
1290 
1291 	ext4_stop_mmpd(sbi);
1292 
1293 	brelse(sbi->s_sbh);
1294 	sb->s_fs_info = NULL;
1295 	/*
1296 	 * Now that we are completely done shutting down the
1297 	 * superblock, we need to actually destroy the kobject.
1298 	 */
1299 	kobject_put(&sbi->s_kobj);
1300 	wait_for_completion(&sbi->s_kobj_unregister);
1301 	if (sbi->s_chksum_driver)
1302 		crypto_free_shash(sbi->s_chksum_driver);
1303 	kfree(sbi->s_blockgroup_lock);
1304 	fs_put_dax(sbi->s_daxdev, NULL);
1305 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1306 #if IS_ENABLED(CONFIG_UNICODE)
1307 	utf8_unload(sb->s_encoding);
1308 #endif
1309 	kfree(sbi);
1310 }
1311 
1312 static struct kmem_cache *ext4_inode_cachep;
1313 
1314 /*
1315  * Called inside transaction, so use GFP_NOFS
1316  */
1317 static struct inode *ext4_alloc_inode(struct super_block *sb)
1318 {
1319 	struct ext4_inode_info *ei;
1320 
1321 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1322 	if (!ei)
1323 		return NULL;
1324 
1325 	inode_set_iversion(&ei->vfs_inode, 1);
1326 	spin_lock_init(&ei->i_raw_lock);
1327 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1328 	atomic_set(&ei->i_prealloc_active, 0);
1329 	spin_lock_init(&ei->i_prealloc_lock);
1330 	ext4_es_init_tree(&ei->i_es_tree);
1331 	rwlock_init(&ei->i_es_lock);
1332 	INIT_LIST_HEAD(&ei->i_es_list);
1333 	ei->i_es_all_nr = 0;
1334 	ei->i_es_shk_nr = 0;
1335 	ei->i_es_shrink_lblk = 0;
1336 	ei->i_reserved_data_blocks = 0;
1337 	spin_lock_init(&(ei->i_block_reservation_lock));
1338 	ext4_init_pending_tree(&ei->i_pending_tree);
1339 #ifdef CONFIG_QUOTA
1340 	ei->i_reserved_quota = 0;
1341 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1342 #endif
1343 	ei->jinode = NULL;
1344 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1345 	spin_lock_init(&ei->i_completed_io_lock);
1346 	ei->i_sync_tid = 0;
1347 	ei->i_datasync_tid = 0;
1348 	atomic_set(&ei->i_unwritten, 0);
1349 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1350 	ext4_fc_init_inode(&ei->vfs_inode);
1351 	mutex_init(&ei->i_fc_lock);
1352 	return &ei->vfs_inode;
1353 }
1354 
1355 static int ext4_drop_inode(struct inode *inode)
1356 {
1357 	int drop = generic_drop_inode(inode);
1358 
1359 	if (!drop)
1360 		drop = fscrypt_drop_inode(inode);
1361 
1362 	trace_ext4_drop_inode(inode, drop);
1363 	return drop;
1364 }
1365 
1366 static void ext4_free_in_core_inode(struct inode *inode)
1367 {
1368 	fscrypt_free_inode(inode);
1369 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1370 		pr_warn("%s: inode %ld still in fc list",
1371 			__func__, inode->i_ino);
1372 	}
1373 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1374 }
1375 
1376 static void ext4_destroy_inode(struct inode *inode)
1377 {
1378 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1379 		ext4_msg(inode->i_sb, KERN_ERR,
1380 			 "Inode %lu (%p): orphan list check failed!",
1381 			 inode->i_ino, EXT4_I(inode));
1382 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1383 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1384 				true);
1385 		dump_stack();
1386 	}
1387 
1388 	if (EXT4_I(inode)->i_reserved_data_blocks)
1389 		ext4_msg(inode->i_sb, KERN_ERR,
1390 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1391 			 inode->i_ino, EXT4_I(inode),
1392 			 EXT4_I(inode)->i_reserved_data_blocks);
1393 }
1394 
1395 static void init_once(void *foo)
1396 {
1397 	struct ext4_inode_info *ei = foo;
1398 
1399 	INIT_LIST_HEAD(&ei->i_orphan);
1400 	init_rwsem(&ei->xattr_sem);
1401 	init_rwsem(&ei->i_data_sem);
1402 	inode_init_once(&ei->vfs_inode);
1403 	ext4_fc_init_inode(&ei->vfs_inode);
1404 }
1405 
1406 static int __init init_inodecache(void)
1407 {
1408 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1409 				sizeof(struct ext4_inode_info), 0,
1410 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1411 					SLAB_ACCOUNT),
1412 				offsetof(struct ext4_inode_info, i_data),
1413 				sizeof_field(struct ext4_inode_info, i_data),
1414 				init_once);
1415 	if (ext4_inode_cachep == NULL)
1416 		return -ENOMEM;
1417 	return 0;
1418 }
1419 
1420 static void destroy_inodecache(void)
1421 {
1422 	/*
1423 	 * Make sure all delayed rcu free inodes are flushed before we
1424 	 * destroy cache.
1425 	 */
1426 	rcu_barrier();
1427 	kmem_cache_destroy(ext4_inode_cachep);
1428 }
1429 
1430 void ext4_clear_inode(struct inode *inode)
1431 {
1432 	ext4_fc_del(inode);
1433 	invalidate_inode_buffers(inode);
1434 	clear_inode(inode);
1435 	ext4_discard_preallocations(inode, 0);
1436 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1437 	dquot_drop(inode);
1438 	if (EXT4_I(inode)->jinode) {
1439 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1440 					       EXT4_I(inode)->jinode);
1441 		jbd2_free_inode(EXT4_I(inode)->jinode);
1442 		EXT4_I(inode)->jinode = NULL;
1443 	}
1444 	fscrypt_put_encryption_info(inode);
1445 	fsverity_cleanup_inode(inode);
1446 }
1447 
1448 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1449 					u64 ino, u32 generation)
1450 {
1451 	struct inode *inode;
1452 
1453 	/*
1454 	 * Currently we don't know the generation for parent directory, so
1455 	 * a generation of 0 means "accept any"
1456 	 */
1457 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1458 	if (IS_ERR(inode))
1459 		return ERR_CAST(inode);
1460 	if (generation && inode->i_generation != generation) {
1461 		iput(inode);
1462 		return ERR_PTR(-ESTALE);
1463 	}
1464 
1465 	return inode;
1466 }
1467 
1468 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1469 					int fh_len, int fh_type)
1470 {
1471 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1472 				    ext4_nfs_get_inode);
1473 }
1474 
1475 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1476 					int fh_len, int fh_type)
1477 {
1478 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1479 				    ext4_nfs_get_inode);
1480 }
1481 
1482 static int ext4_nfs_commit_metadata(struct inode *inode)
1483 {
1484 	struct writeback_control wbc = {
1485 		.sync_mode = WB_SYNC_ALL
1486 	};
1487 
1488 	trace_ext4_nfs_commit_metadata(inode);
1489 	return ext4_write_inode(inode, &wbc);
1490 }
1491 
1492 #ifdef CONFIG_QUOTA
1493 static const char * const quotatypes[] = INITQFNAMES;
1494 #define QTYPE2NAME(t) (quotatypes[t])
1495 
1496 static int ext4_write_dquot(struct dquot *dquot);
1497 static int ext4_acquire_dquot(struct dquot *dquot);
1498 static int ext4_release_dquot(struct dquot *dquot);
1499 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1500 static int ext4_write_info(struct super_block *sb, int type);
1501 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1502 			 const struct path *path);
1503 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1504 			       size_t len, loff_t off);
1505 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1506 				const char *data, size_t len, loff_t off);
1507 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1508 			     unsigned int flags);
1509 
1510 static struct dquot **ext4_get_dquots(struct inode *inode)
1511 {
1512 	return EXT4_I(inode)->i_dquot;
1513 }
1514 
1515 static const struct dquot_operations ext4_quota_operations = {
1516 	.get_reserved_space	= ext4_get_reserved_space,
1517 	.write_dquot		= ext4_write_dquot,
1518 	.acquire_dquot		= ext4_acquire_dquot,
1519 	.release_dquot		= ext4_release_dquot,
1520 	.mark_dirty		= ext4_mark_dquot_dirty,
1521 	.write_info		= ext4_write_info,
1522 	.alloc_dquot		= dquot_alloc,
1523 	.destroy_dquot		= dquot_destroy,
1524 	.get_projid		= ext4_get_projid,
1525 	.get_inode_usage	= ext4_get_inode_usage,
1526 	.get_next_id		= dquot_get_next_id,
1527 };
1528 
1529 static const struct quotactl_ops ext4_qctl_operations = {
1530 	.quota_on	= ext4_quota_on,
1531 	.quota_off	= ext4_quota_off,
1532 	.quota_sync	= dquot_quota_sync,
1533 	.get_state	= dquot_get_state,
1534 	.set_info	= dquot_set_dqinfo,
1535 	.get_dqblk	= dquot_get_dqblk,
1536 	.set_dqblk	= dquot_set_dqblk,
1537 	.get_nextdqblk	= dquot_get_next_dqblk,
1538 };
1539 #endif
1540 
1541 static const struct super_operations ext4_sops = {
1542 	.alloc_inode	= ext4_alloc_inode,
1543 	.free_inode	= ext4_free_in_core_inode,
1544 	.destroy_inode	= ext4_destroy_inode,
1545 	.write_inode	= ext4_write_inode,
1546 	.dirty_inode	= ext4_dirty_inode,
1547 	.drop_inode	= ext4_drop_inode,
1548 	.evict_inode	= ext4_evict_inode,
1549 	.put_super	= ext4_put_super,
1550 	.sync_fs	= ext4_sync_fs,
1551 	.freeze_fs	= ext4_freeze,
1552 	.unfreeze_fs	= ext4_unfreeze,
1553 	.statfs		= ext4_statfs,
1554 	.show_options	= ext4_show_options,
1555 #ifdef CONFIG_QUOTA
1556 	.quota_read	= ext4_quota_read,
1557 	.quota_write	= ext4_quota_write,
1558 	.get_dquots	= ext4_get_dquots,
1559 #endif
1560 };
1561 
1562 static const struct export_operations ext4_export_ops = {
1563 	.fh_to_dentry = ext4_fh_to_dentry,
1564 	.fh_to_parent = ext4_fh_to_parent,
1565 	.get_parent = ext4_get_parent,
1566 	.commit_metadata = ext4_nfs_commit_metadata,
1567 };
1568 
1569 enum {
1570 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1571 	Opt_resgid, Opt_resuid, Opt_sb,
1572 	Opt_nouid32, Opt_debug, Opt_removed,
1573 	Opt_user_xattr, Opt_acl,
1574 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1575 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1576 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1577 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1578 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1579 	Opt_inlinecrypt,
1580 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1581 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1582 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1583 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1584 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1585 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1586 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1587 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1588 	Opt_dioread_nolock, Opt_dioread_lock,
1589 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1590 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1591 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1592 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1593 #ifdef CONFIG_EXT4_DEBUG
1594 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1595 #endif
1596 };
1597 
1598 static const struct constant_table ext4_param_errors[] = {
1599 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1600 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1601 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1602 	{}
1603 };
1604 
1605 static const struct constant_table ext4_param_data[] = {
1606 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1607 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1608 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1609 	{}
1610 };
1611 
1612 static const struct constant_table ext4_param_data_err[] = {
1613 	{"abort",	Opt_data_err_abort},
1614 	{"ignore",	Opt_data_err_ignore},
1615 	{}
1616 };
1617 
1618 static const struct constant_table ext4_param_jqfmt[] = {
1619 	{"vfsold",	QFMT_VFS_OLD},
1620 	{"vfsv0",	QFMT_VFS_V0},
1621 	{"vfsv1",	QFMT_VFS_V1},
1622 	{}
1623 };
1624 
1625 static const struct constant_table ext4_param_dax[] = {
1626 	{"always",	Opt_dax_always},
1627 	{"inode",	Opt_dax_inode},
1628 	{"never",	Opt_dax_never},
1629 	{}
1630 };
1631 
1632 /* String parameter that allows empty argument */
1633 #define fsparam_string_empty(NAME, OPT) \
1634 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1635 
1636 /*
1637  * Mount option specification
1638  * We don't use fsparam_flag_no because of the way we set the
1639  * options and the way we show them in _ext4_show_options(). To
1640  * keep the changes to a minimum, let's keep the negative options
1641  * separate for now.
1642  */
1643 static const struct fs_parameter_spec ext4_param_specs[] = {
1644 	fsparam_flag	("bsddf",		Opt_bsd_df),
1645 	fsparam_flag	("minixdf",		Opt_minix_df),
1646 	fsparam_flag	("grpid",		Opt_grpid),
1647 	fsparam_flag	("bsdgroups",		Opt_grpid),
1648 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1649 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1650 	fsparam_u32	("resgid",		Opt_resgid),
1651 	fsparam_u32	("resuid",		Opt_resuid),
1652 	fsparam_u32	("sb",			Opt_sb),
1653 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1654 	fsparam_flag	("nouid32",		Opt_nouid32),
1655 	fsparam_flag	("debug",		Opt_debug),
1656 	fsparam_flag	("oldalloc",		Opt_removed),
1657 	fsparam_flag	("orlov",		Opt_removed),
1658 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1659 	fsparam_flag	("acl",			Opt_acl),
1660 	fsparam_flag	("norecovery",		Opt_noload),
1661 	fsparam_flag	("noload",		Opt_noload),
1662 	fsparam_flag	("bh",			Opt_removed),
1663 	fsparam_flag	("nobh",		Opt_removed),
1664 	fsparam_u32	("commit",		Opt_commit),
1665 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1666 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1667 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1668 	fsparam_bdev	("journal_path",	Opt_journal_path),
1669 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1670 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1671 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1672 	fsparam_flag	("abort",		Opt_abort),
1673 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1674 	fsparam_enum	("data_err",		Opt_data_err,
1675 						ext4_param_data_err),
1676 	fsparam_string_empty
1677 			("usrjquota",		Opt_usrjquota),
1678 	fsparam_string_empty
1679 			("grpjquota",		Opt_grpjquota),
1680 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1681 	fsparam_flag	("grpquota",		Opt_grpquota),
1682 	fsparam_flag	("quota",		Opt_quota),
1683 	fsparam_flag	("noquota",		Opt_noquota),
1684 	fsparam_flag	("usrquota",		Opt_usrquota),
1685 	fsparam_flag	("prjquota",		Opt_prjquota),
1686 	fsparam_flag	("barrier",		Opt_barrier),
1687 	fsparam_u32	("barrier",		Opt_barrier),
1688 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1689 	fsparam_flag	("i_version",		Opt_removed),
1690 	fsparam_flag	("dax",			Opt_dax),
1691 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1692 	fsparam_u32	("stripe",		Opt_stripe),
1693 	fsparam_flag	("delalloc",		Opt_delalloc),
1694 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1695 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1696 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1697 	fsparam_u32	("debug_want_extra_isize",
1698 						Opt_debug_want_extra_isize),
1699 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1700 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1701 	fsparam_flag	("block_validity",	Opt_block_validity),
1702 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1703 	fsparam_u32	("inode_readahead_blks",
1704 						Opt_inode_readahead_blks),
1705 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1706 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1707 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1708 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1709 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1710 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1711 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1712 	fsparam_flag	("discard",		Opt_discard),
1713 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1714 	fsparam_u32	("init_itable",		Opt_init_itable),
1715 	fsparam_flag	("init_itable",		Opt_init_itable),
1716 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1717 #ifdef CONFIG_EXT4_DEBUG
1718 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1719 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1720 #endif
1721 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1722 	fsparam_flag	("test_dummy_encryption",
1723 						Opt_test_dummy_encryption),
1724 	fsparam_string	("test_dummy_encryption",
1725 						Opt_test_dummy_encryption),
1726 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1727 	fsparam_flag	("nombcache",		Opt_nombcache),
1728 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1729 	fsparam_flag	("prefetch_block_bitmaps",
1730 						Opt_removed),
1731 	fsparam_flag	("no_prefetch_block_bitmaps",
1732 						Opt_no_prefetch_block_bitmaps),
1733 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1734 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1735 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1736 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1737 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1738 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1739 	{}
1740 };
1741 
1742 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1743 
1744 static const char deprecated_msg[] =
1745 	"Mount option \"%s\" will be removed by %s\n"
1746 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1747 
1748 #define MOPT_SET	0x0001
1749 #define MOPT_CLEAR	0x0002
1750 #define MOPT_NOSUPPORT	0x0004
1751 #define MOPT_EXPLICIT	0x0008
1752 #ifdef CONFIG_QUOTA
1753 #define MOPT_Q		0
1754 #define MOPT_QFMT	0x0010
1755 #else
1756 #define MOPT_Q		MOPT_NOSUPPORT
1757 #define MOPT_QFMT	MOPT_NOSUPPORT
1758 #endif
1759 #define MOPT_NO_EXT2	0x0020
1760 #define MOPT_NO_EXT3	0x0040
1761 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1762 #define MOPT_SKIP	0x0080
1763 #define	MOPT_2		0x0100
1764 
1765 static const struct mount_opts {
1766 	int	token;
1767 	int	mount_opt;
1768 	int	flags;
1769 } ext4_mount_opts[] = {
1770 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1771 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1772 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1773 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1774 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1775 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1776 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1777 	 MOPT_EXT4_ONLY | MOPT_SET},
1778 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1779 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1780 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1781 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1782 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1783 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1784 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1785 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1786 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1787 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1788 	{Opt_commit, 0, MOPT_NO_EXT2},
1789 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1790 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1791 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1792 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1793 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1794 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1795 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1796 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1797 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1798 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1799 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1800 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1801 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1802 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1803 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1804 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1805 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1806 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1807 	{Opt_data, 0, MOPT_NO_EXT2},
1808 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1809 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1810 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1811 #else
1812 	{Opt_acl, 0, MOPT_NOSUPPORT},
1813 #endif
1814 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1815 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1816 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1817 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1818 							MOPT_SET | MOPT_Q},
1819 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1820 							MOPT_SET | MOPT_Q},
1821 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1822 							MOPT_SET | MOPT_Q},
1823 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1824 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1825 							MOPT_CLEAR | MOPT_Q},
1826 	{Opt_usrjquota, 0, MOPT_Q},
1827 	{Opt_grpjquota, 0, MOPT_Q},
1828 	{Opt_jqfmt, 0, MOPT_QFMT},
1829 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1830 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1831 	 MOPT_SET},
1832 #ifdef CONFIG_EXT4_DEBUG
1833 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1834 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1835 #endif
1836 	{Opt_err, 0, 0}
1837 };
1838 
1839 #if IS_ENABLED(CONFIG_UNICODE)
1840 static const struct ext4_sb_encodings {
1841 	__u16 magic;
1842 	char *name;
1843 	unsigned int version;
1844 } ext4_sb_encoding_map[] = {
1845 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1846 };
1847 
1848 static const struct ext4_sb_encodings *
1849 ext4_sb_read_encoding(const struct ext4_super_block *es)
1850 {
1851 	__u16 magic = le16_to_cpu(es->s_encoding);
1852 	int i;
1853 
1854 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1855 		if (magic == ext4_sb_encoding_map[i].magic)
1856 			return &ext4_sb_encoding_map[i];
1857 
1858 	return NULL;
1859 }
1860 #endif
1861 
1862 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1863 #define EXT4_SPEC_JQFMT				(1 <<  1)
1864 #define EXT4_SPEC_DATAJ				(1 <<  2)
1865 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1866 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1867 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1868 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1869 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1870 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1871 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1872 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1873 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1874 #define EXT4_SPEC_s_stripe			(1 << 13)
1875 #define EXT4_SPEC_s_resuid			(1 << 14)
1876 #define EXT4_SPEC_s_resgid			(1 << 15)
1877 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1878 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1879 #define EXT4_SPEC_s_sb_block			(1 << 18)
1880 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1881 
1882 struct ext4_fs_context {
1883 	char		*s_qf_names[EXT4_MAXQUOTAS];
1884 	struct fscrypt_dummy_policy dummy_enc_policy;
1885 	int		s_jquota_fmt;	/* Format of quota to use */
1886 #ifdef CONFIG_EXT4_DEBUG
1887 	int s_fc_debug_max_replay;
1888 #endif
1889 	unsigned short	qname_spec;
1890 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1891 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1892 	unsigned long	journal_devnum;
1893 	unsigned long	s_commit_interval;
1894 	unsigned long	s_stripe;
1895 	unsigned int	s_inode_readahead_blks;
1896 	unsigned int	s_want_extra_isize;
1897 	unsigned int	s_li_wait_mult;
1898 	unsigned int	s_max_dir_size_kb;
1899 	unsigned int	journal_ioprio;
1900 	unsigned int	vals_s_mount_opt;
1901 	unsigned int	mask_s_mount_opt;
1902 	unsigned int	vals_s_mount_opt2;
1903 	unsigned int	mask_s_mount_opt2;
1904 	unsigned long	vals_s_mount_flags;
1905 	unsigned long	mask_s_mount_flags;
1906 	unsigned int	opt_flags;	/* MOPT flags */
1907 	unsigned int	spec;
1908 	u32		s_max_batch_time;
1909 	u32		s_min_batch_time;
1910 	kuid_t		s_resuid;
1911 	kgid_t		s_resgid;
1912 	ext4_fsblk_t	s_sb_block;
1913 };
1914 
1915 static void ext4_fc_free(struct fs_context *fc)
1916 {
1917 	struct ext4_fs_context *ctx = fc->fs_private;
1918 	int i;
1919 
1920 	if (!ctx)
1921 		return;
1922 
1923 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1924 		kfree(ctx->s_qf_names[i]);
1925 
1926 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1927 	kfree(ctx);
1928 }
1929 
1930 int ext4_init_fs_context(struct fs_context *fc)
1931 {
1932 	struct ext4_fs_context *ctx;
1933 
1934 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1935 	if (!ctx)
1936 		return -ENOMEM;
1937 
1938 	fc->fs_private = ctx;
1939 	fc->ops = &ext4_context_ops;
1940 
1941 	return 0;
1942 }
1943 
1944 #ifdef CONFIG_QUOTA
1945 /*
1946  * Note the name of the specified quota file.
1947  */
1948 static int note_qf_name(struct fs_context *fc, int qtype,
1949 		       struct fs_parameter *param)
1950 {
1951 	struct ext4_fs_context *ctx = fc->fs_private;
1952 	char *qname;
1953 
1954 	if (param->size < 1) {
1955 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
1956 		return -EINVAL;
1957 	}
1958 	if (strchr(param->string, '/')) {
1959 		ext4_msg(NULL, KERN_ERR,
1960 			 "quotafile must be on filesystem root");
1961 		return -EINVAL;
1962 	}
1963 	if (ctx->s_qf_names[qtype]) {
1964 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
1965 			ext4_msg(NULL, KERN_ERR,
1966 				 "%s quota file already specified",
1967 				 QTYPE2NAME(qtype));
1968 			return -EINVAL;
1969 		}
1970 		return 0;
1971 	}
1972 
1973 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
1974 	if (!qname) {
1975 		ext4_msg(NULL, KERN_ERR,
1976 			 "Not enough memory for storing quotafile name");
1977 		return -ENOMEM;
1978 	}
1979 	ctx->s_qf_names[qtype] = qname;
1980 	ctx->qname_spec |= 1 << qtype;
1981 	ctx->spec |= EXT4_SPEC_JQUOTA;
1982 	return 0;
1983 }
1984 
1985 /*
1986  * Clear the name of the specified quota file.
1987  */
1988 static int unnote_qf_name(struct fs_context *fc, int qtype)
1989 {
1990 	struct ext4_fs_context *ctx = fc->fs_private;
1991 
1992 	if (ctx->s_qf_names[qtype])
1993 		kfree(ctx->s_qf_names[qtype]);
1994 
1995 	ctx->s_qf_names[qtype] = NULL;
1996 	ctx->qname_spec |= 1 << qtype;
1997 	ctx->spec |= EXT4_SPEC_JQUOTA;
1998 	return 0;
1999 }
2000 #endif
2001 
2002 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2003 					    struct ext4_fs_context *ctx)
2004 {
2005 	int err;
2006 
2007 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2008 		ext4_msg(NULL, KERN_WARNING,
2009 			 "test_dummy_encryption option not supported");
2010 		return -EINVAL;
2011 	}
2012 	err = fscrypt_parse_test_dummy_encryption(param,
2013 						  &ctx->dummy_enc_policy);
2014 	if (err == -EINVAL) {
2015 		ext4_msg(NULL, KERN_WARNING,
2016 			 "Value of option \"%s\" is unrecognized", param->key);
2017 	} else if (err == -EEXIST) {
2018 		ext4_msg(NULL, KERN_WARNING,
2019 			 "Conflicting test_dummy_encryption options");
2020 		return -EINVAL;
2021 	}
2022 	return err;
2023 }
2024 
2025 #define EXT4_SET_CTX(name)						\
2026 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2027 				  unsigned long flag)			\
2028 {									\
2029 	ctx->mask_s_##name |= flag;					\
2030 	ctx->vals_s_##name |= flag;					\
2031 }
2032 
2033 #define EXT4_CLEAR_CTX(name)						\
2034 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2035 				    unsigned long flag)			\
2036 {									\
2037 	ctx->mask_s_##name |= flag;					\
2038 	ctx->vals_s_##name &= ~flag;					\
2039 }
2040 
2041 #define EXT4_TEST_CTX(name)						\
2042 static inline unsigned long						\
2043 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2044 {									\
2045 	return (ctx->vals_s_##name & flag);				\
2046 }
2047 
2048 EXT4_SET_CTX(flags); /* set only */
2049 EXT4_SET_CTX(mount_opt);
2050 EXT4_CLEAR_CTX(mount_opt);
2051 EXT4_TEST_CTX(mount_opt);
2052 EXT4_SET_CTX(mount_opt2);
2053 EXT4_CLEAR_CTX(mount_opt2);
2054 EXT4_TEST_CTX(mount_opt2);
2055 
2056 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2057 {
2058 	set_bit(bit, &ctx->mask_s_mount_flags);
2059 	set_bit(bit, &ctx->vals_s_mount_flags);
2060 }
2061 
2062 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2063 {
2064 	struct ext4_fs_context *ctx = fc->fs_private;
2065 	struct fs_parse_result result;
2066 	const struct mount_opts *m;
2067 	int is_remount;
2068 	kuid_t uid;
2069 	kgid_t gid;
2070 	int token;
2071 
2072 	token = fs_parse(fc, ext4_param_specs, param, &result);
2073 	if (token < 0)
2074 		return token;
2075 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2076 
2077 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2078 		if (token == m->token)
2079 			break;
2080 
2081 	ctx->opt_flags |= m->flags;
2082 
2083 	if (m->flags & MOPT_EXPLICIT) {
2084 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2085 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2086 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2087 			ctx_set_mount_opt2(ctx,
2088 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2089 		} else
2090 			return -EINVAL;
2091 	}
2092 
2093 	if (m->flags & MOPT_NOSUPPORT) {
2094 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2095 			 param->key);
2096 		return 0;
2097 	}
2098 
2099 	switch (token) {
2100 #ifdef CONFIG_QUOTA
2101 	case Opt_usrjquota:
2102 		if (!*param->string)
2103 			return unnote_qf_name(fc, USRQUOTA);
2104 		else
2105 			return note_qf_name(fc, USRQUOTA, param);
2106 	case Opt_grpjquota:
2107 		if (!*param->string)
2108 			return unnote_qf_name(fc, GRPQUOTA);
2109 		else
2110 			return note_qf_name(fc, GRPQUOTA, param);
2111 #endif
2112 	case Opt_sb:
2113 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2114 			ext4_msg(NULL, KERN_WARNING,
2115 				 "Ignoring %s option on remount", param->key);
2116 		} else {
2117 			ctx->s_sb_block = result.uint_32;
2118 			ctx->spec |= EXT4_SPEC_s_sb_block;
2119 		}
2120 		return 0;
2121 	case Opt_removed:
2122 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2123 			 param->key);
2124 		return 0;
2125 	case Opt_abort:
2126 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2127 		return 0;
2128 	case Opt_inlinecrypt:
2129 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2130 		ctx_set_flags(ctx, SB_INLINECRYPT);
2131 #else
2132 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2133 #endif
2134 		return 0;
2135 	case Opt_errors:
2136 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2137 		ctx_set_mount_opt(ctx, result.uint_32);
2138 		return 0;
2139 #ifdef CONFIG_QUOTA
2140 	case Opt_jqfmt:
2141 		ctx->s_jquota_fmt = result.uint_32;
2142 		ctx->spec |= EXT4_SPEC_JQFMT;
2143 		return 0;
2144 #endif
2145 	case Opt_data:
2146 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2147 		ctx_set_mount_opt(ctx, result.uint_32);
2148 		ctx->spec |= EXT4_SPEC_DATAJ;
2149 		return 0;
2150 	case Opt_commit:
2151 		if (result.uint_32 == 0)
2152 			ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2153 		else if (result.uint_32 > INT_MAX / HZ) {
2154 			ext4_msg(NULL, KERN_ERR,
2155 				 "Invalid commit interval %d, "
2156 				 "must be smaller than %d",
2157 				 result.uint_32, INT_MAX / HZ);
2158 			return -EINVAL;
2159 		}
2160 		ctx->s_commit_interval = HZ * result.uint_32;
2161 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2162 		return 0;
2163 	case Opt_debug_want_extra_isize:
2164 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2165 			ext4_msg(NULL, KERN_ERR,
2166 				 "Invalid want_extra_isize %d", result.uint_32);
2167 			return -EINVAL;
2168 		}
2169 		ctx->s_want_extra_isize = result.uint_32;
2170 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2171 		return 0;
2172 	case Opt_max_batch_time:
2173 		ctx->s_max_batch_time = result.uint_32;
2174 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2175 		return 0;
2176 	case Opt_min_batch_time:
2177 		ctx->s_min_batch_time = result.uint_32;
2178 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2179 		return 0;
2180 	case Opt_inode_readahead_blks:
2181 		if (result.uint_32 &&
2182 		    (result.uint_32 > (1 << 30) ||
2183 		     !is_power_of_2(result.uint_32))) {
2184 			ext4_msg(NULL, KERN_ERR,
2185 				 "EXT4-fs: inode_readahead_blks must be "
2186 				 "0 or a power of 2 smaller than 2^31");
2187 			return -EINVAL;
2188 		}
2189 		ctx->s_inode_readahead_blks = result.uint_32;
2190 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2191 		return 0;
2192 	case Opt_init_itable:
2193 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2194 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2195 		if (param->type == fs_value_is_string)
2196 			ctx->s_li_wait_mult = result.uint_32;
2197 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2198 		return 0;
2199 	case Opt_max_dir_size_kb:
2200 		ctx->s_max_dir_size_kb = result.uint_32;
2201 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2202 		return 0;
2203 #ifdef CONFIG_EXT4_DEBUG
2204 	case Opt_fc_debug_max_replay:
2205 		ctx->s_fc_debug_max_replay = result.uint_32;
2206 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2207 		return 0;
2208 #endif
2209 	case Opt_stripe:
2210 		ctx->s_stripe = result.uint_32;
2211 		ctx->spec |= EXT4_SPEC_s_stripe;
2212 		return 0;
2213 	case Opt_resuid:
2214 		uid = make_kuid(current_user_ns(), result.uint_32);
2215 		if (!uid_valid(uid)) {
2216 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2217 				 result.uint_32);
2218 			return -EINVAL;
2219 		}
2220 		ctx->s_resuid = uid;
2221 		ctx->spec |= EXT4_SPEC_s_resuid;
2222 		return 0;
2223 	case Opt_resgid:
2224 		gid = make_kgid(current_user_ns(), result.uint_32);
2225 		if (!gid_valid(gid)) {
2226 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2227 				 result.uint_32);
2228 			return -EINVAL;
2229 		}
2230 		ctx->s_resgid = gid;
2231 		ctx->spec |= EXT4_SPEC_s_resgid;
2232 		return 0;
2233 	case Opt_journal_dev:
2234 		if (is_remount) {
2235 			ext4_msg(NULL, KERN_ERR,
2236 				 "Cannot specify journal on remount");
2237 			return -EINVAL;
2238 		}
2239 		ctx->journal_devnum = result.uint_32;
2240 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2241 		return 0;
2242 	case Opt_journal_path:
2243 	{
2244 		struct inode *journal_inode;
2245 		struct path path;
2246 		int error;
2247 
2248 		if (is_remount) {
2249 			ext4_msg(NULL, KERN_ERR,
2250 				 "Cannot specify journal on remount");
2251 			return -EINVAL;
2252 		}
2253 
2254 		error = fs_lookup_param(fc, param, 1, &path);
2255 		if (error) {
2256 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2257 				 "journal device path");
2258 			return -EINVAL;
2259 		}
2260 
2261 		journal_inode = d_inode(path.dentry);
2262 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2263 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2264 		path_put(&path);
2265 		return 0;
2266 	}
2267 	case Opt_journal_ioprio:
2268 		if (result.uint_32 > 7) {
2269 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2270 				 " (must be 0-7)");
2271 			return -EINVAL;
2272 		}
2273 		ctx->journal_ioprio =
2274 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2275 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2276 		return 0;
2277 	case Opt_test_dummy_encryption:
2278 		return ext4_parse_test_dummy_encryption(param, ctx);
2279 	case Opt_dax:
2280 	case Opt_dax_type:
2281 #ifdef CONFIG_FS_DAX
2282 	{
2283 		int type = (token == Opt_dax) ?
2284 			   Opt_dax : result.uint_32;
2285 
2286 		switch (type) {
2287 		case Opt_dax:
2288 		case Opt_dax_always:
2289 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2290 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2291 			break;
2292 		case Opt_dax_never:
2293 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2294 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2295 			break;
2296 		case Opt_dax_inode:
2297 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2298 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2299 			/* Strictly for printing options */
2300 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2301 			break;
2302 		}
2303 		return 0;
2304 	}
2305 #else
2306 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2307 		return -EINVAL;
2308 #endif
2309 	case Opt_data_err:
2310 		if (result.uint_32 == Opt_data_err_abort)
2311 			ctx_set_mount_opt(ctx, m->mount_opt);
2312 		else if (result.uint_32 == Opt_data_err_ignore)
2313 			ctx_clear_mount_opt(ctx, m->mount_opt);
2314 		return 0;
2315 	case Opt_mb_optimize_scan:
2316 		if (result.int_32 == 1) {
2317 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2318 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2319 		} else if (result.int_32 == 0) {
2320 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2321 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2322 		} else {
2323 			ext4_msg(NULL, KERN_WARNING,
2324 				 "mb_optimize_scan should be set to 0 or 1.");
2325 			return -EINVAL;
2326 		}
2327 		return 0;
2328 	}
2329 
2330 	/*
2331 	 * At this point we should only be getting options requiring MOPT_SET,
2332 	 * or MOPT_CLEAR. Anything else is a bug
2333 	 */
2334 	if (m->token == Opt_err) {
2335 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2336 			 param->key);
2337 		WARN_ON(1);
2338 		return -EINVAL;
2339 	}
2340 
2341 	else {
2342 		unsigned int set = 0;
2343 
2344 		if ((param->type == fs_value_is_flag) ||
2345 		    result.uint_32 > 0)
2346 			set = 1;
2347 
2348 		if (m->flags & MOPT_CLEAR)
2349 			set = !set;
2350 		else if (unlikely(!(m->flags & MOPT_SET))) {
2351 			ext4_msg(NULL, KERN_WARNING,
2352 				 "buggy handling of option %s",
2353 				 param->key);
2354 			WARN_ON(1);
2355 			return -EINVAL;
2356 		}
2357 		if (m->flags & MOPT_2) {
2358 			if (set != 0)
2359 				ctx_set_mount_opt2(ctx, m->mount_opt);
2360 			else
2361 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2362 		} else {
2363 			if (set != 0)
2364 				ctx_set_mount_opt(ctx, m->mount_opt);
2365 			else
2366 				ctx_clear_mount_opt(ctx, m->mount_opt);
2367 		}
2368 	}
2369 
2370 	return 0;
2371 }
2372 
2373 static int parse_options(struct fs_context *fc, char *options)
2374 {
2375 	struct fs_parameter param;
2376 	int ret;
2377 	char *key;
2378 
2379 	if (!options)
2380 		return 0;
2381 
2382 	while ((key = strsep(&options, ",")) != NULL) {
2383 		if (*key) {
2384 			size_t v_len = 0;
2385 			char *value = strchr(key, '=');
2386 
2387 			param.type = fs_value_is_flag;
2388 			param.string = NULL;
2389 
2390 			if (value) {
2391 				if (value == key)
2392 					continue;
2393 
2394 				*value++ = 0;
2395 				v_len = strlen(value);
2396 				param.string = kmemdup_nul(value, v_len,
2397 							   GFP_KERNEL);
2398 				if (!param.string)
2399 					return -ENOMEM;
2400 				param.type = fs_value_is_string;
2401 			}
2402 
2403 			param.key = key;
2404 			param.size = v_len;
2405 
2406 			ret = ext4_parse_param(fc, &param);
2407 			if (param.string)
2408 				kfree(param.string);
2409 			if (ret < 0)
2410 				return ret;
2411 		}
2412 	}
2413 
2414 	ret = ext4_validate_options(fc);
2415 	if (ret < 0)
2416 		return ret;
2417 
2418 	return 0;
2419 }
2420 
2421 static int parse_apply_sb_mount_options(struct super_block *sb,
2422 					struct ext4_fs_context *m_ctx)
2423 {
2424 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2425 	char *s_mount_opts = NULL;
2426 	struct ext4_fs_context *s_ctx = NULL;
2427 	struct fs_context *fc = NULL;
2428 	int ret = -ENOMEM;
2429 
2430 	if (!sbi->s_es->s_mount_opts[0])
2431 		return 0;
2432 
2433 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2434 				sizeof(sbi->s_es->s_mount_opts),
2435 				GFP_KERNEL);
2436 	if (!s_mount_opts)
2437 		return ret;
2438 
2439 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2440 	if (!fc)
2441 		goto out_free;
2442 
2443 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2444 	if (!s_ctx)
2445 		goto out_free;
2446 
2447 	fc->fs_private = s_ctx;
2448 	fc->s_fs_info = sbi;
2449 
2450 	ret = parse_options(fc, s_mount_opts);
2451 	if (ret < 0)
2452 		goto parse_failed;
2453 
2454 	ret = ext4_check_opt_consistency(fc, sb);
2455 	if (ret < 0) {
2456 parse_failed:
2457 		ext4_msg(sb, KERN_WARNING,
2458 			 "failed to parse options in superblock: %s",
2459 			 s_mount_opts);
2460 		ret = 0;
2461 		goto out_free;
2462 	}
2463 
2464 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2465 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2466 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2467 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2468 
2469 	ext4_apply_options(fc, sb);
2470 	ret = 0;
2471 
2472 out_free:
2473 	if (fc) {
2474 		ext4_fc_free(fc);
2475 		kfree(fc);
2476 	}
2477 	kfree(s_mount_opts);
2478 	return ret;
2479 }
2480 
2481 static void ext4_apply_quota_options(struct fs_context *fc,
2482 				     struct super_block *sb)
2483 {
2484 #ifdef CONFIG_QUOTA
2485 	bool quota_feature = ext4_has_feature_quota(sb);
2486 	struct ext4_fs_context *ctx = fc->fs_private;
2487 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2488 	char *qname;
2489 	int i;
2490 
2491 	if (quota_feature)
2492 		return;
2493 
2494 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2495 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2496 			if (!(ctx->qname_spec & (1 << i)))
2497 				continue;
2498 
2499 			qname = ctx->s_qf_names[i]; /* May be NULL */
2500 			if (qname)
2501 				set_opt(sb, QUOTA);
2502 			ctx->s_qf_names[i] = NULL;
2503 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2504 						lockdep_is_held(&sb->s_umount));
2505 			if (qname)
2506 				kfree_rcu(qname);
2507 		}
2508 	}
2509 
2510 	if (ctx->spec & EXT4_SPEC_JQFMT)
2511 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2512 #endif
2513 }
2514 
2515 /*
2516  * Check quota settings consistency.
2517  */
2518 static int ext4_check_quota_consistency(struct fs_context *fc,
2519 					struct super_block *sb)
2520 {
2521 #ifdef CONFIG_QUOTA
2522 	struct ext4_fs_context *ctx = fc->fs_private;
2523 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2524 	bool quota_feature = ext4_has_feature_quota(sb);
2525 	bool quota_loaded = sb_any_quota_loaded(sb);
2526 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2527 	int quota_flags, i;
2528 
2529 	/*
2530 	 * We do the test below only for project quotas. 'usrquota' and
2531 	 * 'grpquota' mount options are allowed even without quota feature
2532 	 * to support legacy quotas in quota files.
2533 	 */
2534 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2535 	    !ext4_has_feature_project(sb)) {
2536 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2537 			 "Cannot enable project quota enforcement.");
2538 		return -EINVAL;
2539 	}
2540 
2541 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2542 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2543 	if (quota_loaded &&
2544 	    ctx->mask_s_mount_opt & quota_flags &&
2545 	    !ctx_test_mount_opt(ctx, quota_flags))
2546 		goto err_quota_change;
2547 
2548 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2549 
2550 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2551 			if (!(ctx->qname_spec & (1 << i)))
2552 				continue;
2553 
2554 			if (quota_loaded &&
2555 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2556 				goto err_jquota_change;
2557 
2558 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2559 			    strcmp(get_qf_name(sb, sbi, i),
2560 				   ctx->s_qf_names[i]) != 0)
2561 				goto err_jquota_specified;
2562 		}
2563 
2564 		if (quota_feature) {
2565 			ext4_msg(NULL, KERN_INFO,
2566 				 "Journaled quota options ignored when "
2567 				 "QUOTA feature is enabled");
2568 			return 0;
2569 		}
2570 	}
2571 
2572 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2573 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2574 			goto err_jquota_change;
2575 		if (quota_feature) {
2576 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2577 				 "ignored when QUOTA feature is enabled");
2578 			return 0;
2579 		}
2580 	}
2581 
2582 	/* Make sure we don't mix old and new quota format */
2583 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2584 		       ctx->s_qf_names[USRQUOTA]);
2585 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2586 		       ctx->s_qf_names[GRPQUOTA]);
2587 
2588 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2589 		    test_opt(sb, USRQUOTA));
2590 
2591 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2592 		    test_opt(sb, GRPQUOTA));
2593 
2594 	if (usr_qf_name) {
2595 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2596 		usrquota = false;
2597 	}
2598 	if (grp_qf_name) {
2599 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2600 		grpquota = false;
2601 	}
2602 
2603 	if (usr_qf_name || grp_qf_name) {
2604 		if (usrquota || grpquota) {
2605 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2606 				 "format mixing");
2607 			return -EINVAL;
2608 		}
2609 
2610 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2611 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2612 				 "not specified");
2613 			return -EINVAL;
2614 		}
2615 	}
2616 
2617 	return 0;
2618 
2619 err_quota_change:
2620 	ext4_msg(NULL, KERN_ERR,
2621 		 "Cannot change quota options when quota turned on");
2622 	return -EINVAL;
2623 err_jquota_change:
2624 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2625 		 "options when quota turned on");
2626 	return -EINVAL;
2627 err_jquota_specified:
2628 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2629 		 QTYPE2NAME(i));
2630 	return -EINVAL;
2631 #else
2632 	return 0;
2633 #endif
2634 }
2635 
2636 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2637 					    struct super_block *sb)
2638 {
2639 	const struct ext4_fs_context *ctx = fc->fs_private;
2640 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2641 	int err;
2642 
2643 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2644 		return 0;
2645 
2646 	if (!ext4_has_feature_encrypt(sb)) {
2647 		ext4_msg(NULL, KERN_WARNING,
2648 			 "test_dummy_encryption requires encrypt feature");
2649 		return -EINVAL;
2650 	}
2651 	/*
2652 	 * This mount option is just for testing, and it's not worthwhile to
2653 	 * implement the extra complexity (e.g. RCU protection) that would be
2654 	 * needed to allow it to be set or changed during remount.  We do allow
2655 	 * it to be specified during remount, but only if there is no change.
2656 	 */
2657 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2658 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2659 						 &ctx->dummy_enc_policy))
2660 			return 0;
2661 		ext4_msg(NULL, KERN_WARNING,
2662 			 "Can't set or change test_dummy_encryption on remount");
2663 		return -EINVAL;
2664 	}
2665 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2666 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2667 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2668 						 &ctx->dummy_enc_policy))
2669 			return 0;
2670 		ext4_msg(NULL, KERN_WARNING,
2671 			 "Conflicting test_dummy_encryption options");
2672 		return -EINVAL;
2673 	}
2674 	/*
2675 	 * fscrypt_add_test_dummy_key() technically changes the super_block, so
2676 	 * technically it should be delayed until ext4_apply_options() like the
2677 	 * other changes.  But since we never get here for remounts (see above),
2678 	 * and this is the last chance to report errors, we do it here.
2679 	 */
2680 	err = fscrypt_add_test_dummy_key(sb, &ctx->dummy_enc_policy);
2681 	if (err)
2682 		ext4_msg(NULL, KERN_WARNING,
2683 			 "Error adding test dummy encryption key [%d]", err);
2684 	return err;
2685 }
2686 
2687 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2688 					     struct super_block *sb)
2689 {
2690 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2691 	    /* if already set, it was already verified to be the same */
2692 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2693 		return;
2694 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2695 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2696 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2697 }
2698 
2699 static int ext4_check_opt_consistency(struct fs_context *fc,
2700 				      struct super_block *sb)
2701 {
2702 	struct ext4_fs_context *ctx = fc->fs_private;
2703 	struct ext4_sb_info *sbi = fc->s_fs_info;
2704 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2705 	int err;
2706 
2707 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2708 		ext4_msg(NULL, KERN_ERR,
2709 			 "Mount option(s) incompatible with ext2");
2710 		return -EINVAL;
2711 	}
2712 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2713 		ext4_msg(NULL, KERN_ERR,
2714 			 "Mount option(s) incompatible with ext3");
2715 		return -EINVAL;
2716 	}
2717 
2718 	if (ctx->s_want_extra_isize >
2719 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2720 		ext4_msg(NULL, KERN_ERR,
2721 			 "Invalid want_extra_isize %d",
2722 			 ctx->s_want_extra_isize);
2723 		return -EINVAL;
2724 	}
2725 
2726 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2727 		int blocksize =
2728 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2729 		if (blocksize < PAGE_SIZE)
2730 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2731 				 "experimental mount option 'dioread_nolock' "
2732 				 "for blocksize < PAGE_SIZE");
2733 	}
2734 
2735 	err = ext4_check_test_dummy_encryption(fc, sb);
2736 	if (err)
2737 		return err;
2738 
2739 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2740 		if (!sbi->s_journal) {
2741 			ext4_msg(NULL, KERN_WARNING,
2742 				 "Remounting file system with no journal "
2743 				 "so ignoring journalled data option");
2744 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2745 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2746 			   test_opt(sb, DATA_FLAGS)) {
2747 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2748 				 "on remount");
2749 			return -EINVAL;
2750 		}
2751 	}
2752 
2753 	if (is_remount) {
2754 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2755 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2756 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2757 				 "both data=journal and dax");
2758 			return -EINVAL;
2759 		}
2760 
2761 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2762 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2763 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2764 fail_dax_change_remount:
2765 			ext4_msg(NULL, KERN_ERR, "can't change "
2766 				 "dax mount option while remounting");
2767 			return -EINVAL;
2768 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2769 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2770 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2771 			goto fail_dax_change_remount;
2772 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2773 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2774 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2775 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2776 			goto fail_dax_change_remount;
2777 		}
2778 	}
2779 
2780 	return ext4_check_quota_consistency(fc, sb);
2781 }
2782 
2783 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2784 {
2785 	struct ext4_fs_context *ctx = fc->fs_private;
2786 	struct ext4_sb_info *sbi = fc->s_fs_info;
2787 
2788 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2789 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2790 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2791 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2792 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2793 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2794 	sb->s_flags &= ~ctx->mask_s_flags;
2795 	sb->s_flags |= ctx->vals_s_flags;
2796 
2797 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2798 	APPLY(s_commit_interval);
2799 	APPLY(s_stripe);
2800 	APPLY(s_max_batch_time);
2801 	APPLY(s_min_batch_time);
2802 	APPLY(s_want_extra_isize);
2803 	APPLY(s_inode_readahead_blks);
2804 	APPLY(s_max_dir_size_kb);
2805 	APPLY(s_li_wait_mult);
2806 	APPLY(s_resgid);
2807 	APPLY(s_resuid);
2808 
2809 #ifdef CONFIG_EXT4_DEBUG
2810 	APPLY(s_fc_debug_max_replay);
2811 #endif
2812 
2813 	ext4_apply_quota_options(fc, sb);
2814 	ext4_apply_test_dummy_encryption(ctx, sb);
2815 }
2816 
2817 
2818 static int ext4_validate_options(struct fs_context *fc)
2819 {
2820 #ifdef CONFIG_QUOTA
2821 	struct ext4_fs_context *ctx = fc->fs_private;
2822 	char *usr_qf_name, *grp_qf_name;
2823 
2824 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2825 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2826 
2827 	if (usr_qf_name || grp_qf_name) {
2828 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2829 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2830 
2831 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2832 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2833 
2834 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2835 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2836 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2837 				 "format mixing");
2838 			return -EINVAL;
2839 		}
2840 	}
2841 #endif
2842 	return 1;
2843 }
2844 
2845 static inline void ext4_show_quota_options(struct seq_file *seq,
2846 					   struct super_block *sb)
2847 {
2848 #if defined(CONFIG_QUOTA)
2849 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2850 	char *usr_qf_name, *grp_qf_name;
2851 
2852 	if (sbi->s_jquota_fmt) {
2853 		char *fmtname = "";
2854 
2855 		switch (sbi->s_jquota_fmt) {
2856 		case QFMT_VFS_OLD:
2857 			fmtname = "vfsold";
2858 			break;
2859 		case QFMT_VFS_V0:
2860 			fmtname = "vfsv0";
2861 			break;
2862 		case QFMT_VFS_V1:
2863 			fmtname = "vfsv1";
2864 			break;
2865 		}
2866 		seq_printf(seq, ",jqfmt=%s", fmtname);
2867 	}
2868 
2869 	rcu_read_lock();
2870 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2871 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2872 	if (usr_qf_name)
2873 		seq_show_option(seq, "usrjquota", usr_qf_name);
2874 	if (grp_qf_name)
2875 		seq_show_option(seq, "grpjquota", grp_qf_name);
2876 	rcu_read_unlock();
2877 #endif
2878 }
2879 
2880 static const char *token2str(int token)
2881 {
2882 	const struct fs_parameter_spec *spec;
2883 
2884 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2885 		if (spec->opt == token && !spec->type)
2886 			break;
2887 	return spec->name;
2888 }
2889 
2890 /*
2891  * Show an option if
2892  *  - it's set to a non-default value OR
2893  *  - if the per-sb default is different from the global default
2894  */
2895 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2896 			      int nodefs)
2897 {
2898 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2899 	struct ext4_super_block *es = sbi->s_es;
2900 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2901 	const struct mount_opts *m;
2902 	char sep = nodefs ? '\n' : ',';
2903 
2904 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2905 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2906 
2907 	if (sbi->s_sb_block != 1)
2908 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2909 
2910 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2911 		int want_set = m->flags & MOPT_SET;
2912 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2913 		    m->flags & MOPT_SKIP)
2914 			continue;
2915 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2916 			continue; /* skip if same as the default */
2917 		if ((want_set &&
2918 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2919 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2920 			continue; /* select Opt_noFoo vs Opt_Foo */
2921 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2922 	}
2923 
2924 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2925 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2926 		SEQ_OPTS_PRINT("resuid=%u",
2927 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2928 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2929 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2930 		SEQ_OPTS_PRINT("resgid=%u",
2931 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2932 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2933 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2934 		SEQ_OPTS_PUTS("errors=remount-ro");
2935 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2936 		SEQ_OPTS_PUTS("errors=continue");
2937 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2938 		SEQ_OPTS_PUTS("errors=panic");
2939 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2940 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2941 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2942 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2943 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2944 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2945 	if (nodefs || sbi->s_stripe)
2946 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2947 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2948 			(sbi->s_mount_opt ^ def_mount_opt)) {
2949 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2950 			SEQ_OPTS_PUTS("data=journal");
2951 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2952 			SEQ_OPTS_PUTS("data=ordered");
2953 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2954 			SEQ_OPTS_PUTS("data=writeback");
2955 	}
2956 	if (nodefs ||
2957 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2958 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2959 			       sbi->s_inode_readahead_blks);
2960 
2961 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2962 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2963 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2964 	if (nodefs || sbi->s_max_dir_size_kb)
2965 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2966 	if (test_opt(sb, DATA_ERR_ABORT))
2967 		SEQ_OPTS_PUTS("data_err=abort");
2968 
2969 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2970 
2971 	if (sb->s_flags & SB_INLINECRYPT)
2972 		SEQ_OPTS_PUTS("inlinecrypt");
2973 
2974 	if (test_opt(sb, DAX_ALWAYS)) {
2975 		if (IS_EXT2_SB(sb))
2976 			SEQ_OPTS_PUTS("dax");
2977 		else
2978 			SEQ_OPTS_PUTS("dax=always");
2979 	} else if (test_opt2(sb, DAX_NEVER)) {
2980 		SEQ_OPTS_PUTS("dax=never");
2981 	} else if (test_opt2(sb, DAX_INODE)) {
2982 		SEQ_OPTS_PUTS("dax=inode");
2983 	}
2984 
2985 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
2986 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
2987 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
2988 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
2989 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
2990 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
2991 	}
2992 
2993 	ext4_show_quota_options(seq, sb);
2994 	return 0;
2995 }
2996 
2997 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2998 {
2999 	return _ext4_show_options(seq, root->d_sb, 0);
3000 }
3001 
3002 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3003 {
3004 	struct super_block *sb = seq->private;
3005 	int rc;
3006 
3007 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3008 	rc = _ext4_show_options(seq, sb, 1);
3009 	seq_puts(seq, "\n");
3010 	return rc;
3011 }
3012 
3013 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3014 			    int read_only)
3015 {
3016 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3017 	int err = 0;
3018 
3019 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3020 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3021 			 "forcing read-only mode");
3022 		err = -EROFS;
3023 		goto done;
3024 	}
3025 	if (read_only)
3026 		goto done;
3027 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3028 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3029 			 "running e2fsck is recommended");
3030 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3031 		ext4_msg(sb, KERN_WARNING,
3032 			 "warning: mounting fs with errors, "
3033 			 "running e2fsck is recommended");
3034 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3035 		 le16_to_cpu(es->s_mnt_count) >=
3036 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3037 		ext4_msg(sb, KERN_WARNING,
3038 			 "warning: maximal mount count reached, "
3039 			 "running e2fsck is recommended");
3040 	else if (le32_to_cpu(es->s_checkinterval) &&
3041 		 (ext4_get_tstamp(es, s_lastcheck) +
3042 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3043 		ext4_msg(sb, KERN_WARNING,
3044 			 "warning: checktime reached, "
3045 			 "running e2fsck is recommended");
3046 	if (!sbi->s_journal)
3047 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3048 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3049 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3050 	le16_add_cpu(&es->s_mnt_count, 1);
3051 	ext4_update_tstamp(es, s_mtime);
3052 	if (sbi->s_journal) {
3053 		ext4_set_feature_journal_needs_recovery(sb);
3054 		if (ext4_has_feature_orphan_file(sb))
3055 			ext4_set_feature_orphan_present(sb);
3056 	}
3057 
3058 	err = ext4_commit_super(sb);
3059 done:
3060 	if (test_opt(sb, DEBUG))
3061 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3062 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3063 			sb->s_blocksize,
3064 			sbi->s_groups_count,
3065 			EXT4_BLOCKS_PER_GROUP(sb),
3066 			EXT4_INODES_PER_GROUP(sb),
3067 			sbi->s_mount_opt, sbi->s_mount_opt2);
3068 	return err;
3069 }
3070 
3071 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3072 {
3073 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3074 	struct flex_groups **old_groups, **new_groups;
3075 	int size, i, j;
3076 
3077 	if (!sbi->s_log_groups_per_flex)
3078 		return 0;
3079 
3080 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3081 	if (size <= sbi->s_flex_groups_allocated)
3082 		return 0;
3083 
3084 	new_groups = kvzalloc(roundup_pow_of_two(size *
3085 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3086 	if (!new_groups) {
3087 		ext4_msg(sb, KERN_ERR,
3088 			 "not enough memory for %d flex group pointers", size);
3089 		return -ENOMEM;
3090 	}
3091 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3092 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3093 					 sizeof(struct flex_groups)),
3094 					 GFP_KERNEL);
3095 		if (!new_groups[i]) {
3096 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3097 				kvfree(new_groups[j]);
3098 			kvfree(new_groups);
3099 			ext4_msg(sb, KERN_ERR,
3100 				 "not enough memory for %d flex groups", size);
3101 			return -ENOMEM;
3102 		}
3103 	}
3104 	rcu_read_lock();
3105 	old_groups = rcu_dereference(sbi->s_flex_groups);
3106 	if (old_groups)
3107 		memcpy(new_groups, old_groups,
3108 		       (sbi->s_flex_groups_allocated *
3109 			sizeof(struct flex_groups *)));
3110 	rcu_read_unlock();
3111 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3112 	sbi->s_flex_groups_allocated = size;
3113 	if (old_groups)
3114 		ext4_kvfree_array_rcu(old_groups);
3115 	return 0;
3116 }
3117 
3118 static int ext4_fill_flex_info(struct super_block *sb)
3119 {
3120 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3121 	struct ext4_group_desc *gdp = NULL;
3122 	struct flex_groups *fg;
3123 	ext4_group_t flex_group;
3124 	int i, err;
3125 
3126 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3127 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3128 		sbi->s_log_groups_per_flex = 0;
3129 		return 1;
3130 	}
3131 
3132 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3133 	if (err)
3134 		goto failed;
3135 
3136 	for (i = 0; i < sbi->s_groups_count; i++) {
3137 		gdp = ext4_get_group_desc(sb, i, NULL);
3138 
3139 		flex_group = ext4_flex_group(sbi, i);
3140 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3141 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3142 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3143 			     &fg->free_clusters);
3144 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3145 	}
3146 
3147 	return 1;
3148 failed:
3149 	return 0;
3150 }
3151 
3152 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3153 				   struct ext4_group_desc *gdp)
3154 {
3155 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3156 	__u16 crc = 0;
3157 	__le32 le_group = cpu_to_le32(block_group);
3158 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3159 
3160 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3161 		/* Use new metadata_csum algorithm */
3162 		__u32 csum32;
3163 		__u16 dummy_csum = 0;
3164 
3165 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3166 				     sizeof(le_group));
3167 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3168 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3169 				     sizeof(dummy_csum));
3170 		offset += sizeof(dummy_csum);
3171 		if (offset < sbi->s_desc_size)
3172 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3173 					     sbi->s_desc_size - offset);
3174 
3175 		crc = csum32 & 0xFFFF;
3176 		goto out;
3177 	}
3178 
3179 	/* old crc16 code */
3180 	if (!ext4_has_feature_gdt_csum(sb))
3181 		return 0;
3182 
3183 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3184 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3185 	crc = crc16(crc, (__u8 *)gdp, offset);
3186 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3187 	/* for checksum of struct ext4_group_desc do the rest...*/
3188 	if (ext4_has_feature_64bit(sb) &&
3189 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3190 		crc = crc16(crc, (__u8 *)gdp + offset,
3191 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3192 				offset);
3193 
3194 out:
3195 	return cpu_to_le16(crc);
3196 }
3197 
3198 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3199 				struct ext4_group_desc *gdp)
3200 {
3201 	if (ext4_has_group_desc_csum(sb) &&
3202 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3203 		return 0;
3204 
3205 	return 1;
3206 }
3207 
3208 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3209 			      struct ext4_group_desc *gdp)
3210 {
3211 	if (!ext4_has_group_desc_csum(sb))
3212 		return;
3213 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3214 }
3215 
3216 /* Called at mount-time, super-block is locked */
3217 static int ext4_check_descriptors(struct super_block *sb,
3218 				  ext4_fsblk_t sb_block,
3219 				  ext4_group_t *first_not_zeroed)
3220 {
3221 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3222 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3223 	ext4_fsblk_t last_block;
3224 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3225 	ext4_fsblk_t block_bitmap;
3226 	ext4_fsblk_t inode_bitmap;
3227 	ext4_fsblk_t inode_table;
3228 	int flexbg_flag = 0;
3229 	ext4_group_t i, grp = sbi->s_groups_count;
3230 
3231 	if (ext4_has_feature_flex_bg(sb))
3232 		flexbg_flag = 1;
3233 
3234 	ext4_debug("Checking group descriptors");
3235 
3236 	for (i = 0; i < sbi->s_groups_count; i++) {
3237 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3238 
3239 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3240 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3241 		else
3242 			last_block = first_block +
3243 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3244 
3245 		if ((grp == sbi->s_groups_count) &&
3246 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3247 			grp = i;
3248 
3249 		block_bitmap = ext4_block_bitmap(sb, gdp);
3250 		if (block_bitmap == sb_block) {
3251 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3252 				 "Block bitmap for group %u overlaps "
3253 				 "superblock", i);
3254 			if (!sb_rdonly(sb))
3255 				return 0;
3256 		}
3257 		if (block_bitmap >= sb_block + 1 &&
3258 		    block_bitmap <= last_bg_block) {
3259 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3260 				 "Block bitmap for group %u overlaps "
3261 				 "block group descriptors", i);
3262 			if (!sb_rdonly(sb))
3263 				return 0;
3264 		}
3265 		if (block_bitmap < first_block || block_bitmap > last_block) {
3266 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3267 			       "Block bitmap for group %u not in group "
3268 			       "(block %llu)!", i, block_bitmap);
3269 			return 0;
3270 		}
3271 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3272 		if (inode_bitmap == sb_block) {
3273 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3274 				 "Inode bitmap for group %u overlaps "
3275 				 "superblock", i);
3276 			if (!sb_rdonly(sb))
3277 				return 0;
3278 		}
3279 		if (inode_bitmap >= sb_block + 1 &&
3280 		    inode_bitmap <= last_bg_block) {
3281 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3282 				 "Inode bitmap for group %u overlaps "
3283 				 "block group descriptors", i);
3284 			if (!sb_rdonly(sb))
3285 				return 0;
3286 		}
3287 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3288 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3289 			       "Inode bitmap for group %u not in group "
3290 			       "(block %llu)!", i, inode_bitmap);
3291 			return 0;
3292 		}
3293 		inode_table = ext4_inode_table(sb, gdp);
3294 		if (inode_table == sb_block) {
3295 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3296 				 "Inode table for group %u overlaps "
3297 				 "superblock", i);
3298 			if (!sb_rdonly(sb))
3299 				return 0;
3300 		}
3301 		if (inode_table >= sb_block + 1 &&
3302 		    inode_table <= last_bg_block) {
3303 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3304 				 "Inode table for group %u overlaps "
3305 				 "block group descriptors", i);
3306 			if (!sb_rdonly(sb))
3307 				return 0;
3308 		}
3309 		if (inode_table < first_block ||
3310 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3311 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3312 			       "Inode table for group %u not in group "
3313 			       "(block %llu)!", i, inode_table);
3314 			return 0;
3315 		}
3316 		ext4_lock_group(sb, i);
3317 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3318 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3319 				 "Checksum for group %u failed (%u!=%u)",
3320 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3321 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3322 			if (!sb_rdonly(sb)) {
3323 				ext4_unlock_group(sb, i);
3324 				return 0;
3325 			}
3326 		}
3327 		ext4_unlock_group(sb, i);
3328 		if (!flexbg_flag)
3329 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3330 	}
3331 	if (NULL != first_not_zeroed)
3332 		*first_not_zeroed = grp;
3333 	return 1;
3334 }
3335 
3336 /*
3337  * Maximal extent format file size.
3338  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3339  * extent format containers, within a sector_t, and within i_blocks
3340  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3341  * so that won't be a limiting factor.
3342  *
3343  * However there is other limiting factor. We do store extents in the form
3344  * of starting block and length, hence the resulting length of the extent
3345  * covering maximum file size must fit into on-disk format containers as
3346  * well. Given that length is always by 1 unit bigger than max unit (because
3347  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3348  *
3349  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3350  */
3351 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3352 {
3353 	loff_t res;
3354 	loff_t upper_limit = MAX_LFS_FILESIZE;
3355 
3356 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3357 
3358 	if (!has_huge_files) {
3359 		upper_limit = (1LL << 32) - 1;
3360 
3361 		/* total blocks in file system block size */
3362 		upper_limit >>= (blkbits - 9);
3363 		upper_limit <<= blkbits;
3364 	}
3365 
3366 	/*
3367 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3368 	 * by one fs block, so ee_len can cover the extent of maximum file
3369 	 * size
3370 	 */
3371 	res = (1LL << 32) - 1;
3372 	res <<= blkbits;
3373 
3374 	/* Sanity check against vm- & vfs- imposed limits */
3375 	if (res > upper_limit)
3376 		res = upper_limit;
3377 
3378 	return res;
3379 }
3380 
3381 /*
3382  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3383  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3384  * We need to be 1 filesystem block less than the 2^48 sector limit.
3385  */
3386 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3387 {
3388 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3389 	int meta_blocks;
3390 	unsigned int ppb = 1 << (bits - 2);
3391 
3392 	/*
3393 	 * This is calculated to be the largest file size for a dense, block
3394 	 * mapped file such that the file's total number of 512-byte sectors,
3395 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3396 	 *
3397 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3398 	 * number of 512-byte sectors of the file.
3399 	 */
3400 	if (!has_huge_files) {
3401 		/*
3402 		 * !has_huge_files or implies that the inode i_block field
3403 		 * represents total file blocks in 2^32 512-byte sectors ==
3404 		 * size of vfs inode i_blocks * 8
3405 		 */
3406 		upper_limit = (1LL << 32) - 1;
3407 
3408 		/* total blocks in file system block size */
3409 		upper_limit >>= (bits - 9);
3410 
3411 	} else {
3412 		/*
3413 		 * We use 48 bit ext4_inode i_blocks
3414 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3415 		 * represent total number of blocks in
3416 		 * file system block size
3417 		 */
3418 		upper_limit = (1LL << 48) - 1;
3419 
3420 	}
3421 
3422 	/* Compute how many blocks we can address by block tree */
3423 	res += ppb;
3424 	res += ppb * ppb;
3425 	res += ((loff_t)ppb) * ppb * ppb;
3426 	/* Compute how many metadata blocks are needed */
3427 	meta_blocks = 1;
3428 	meta_blocks += 1 + ppb;
3429 	meta_blocks += 1 + ppb + ppb * ppb;
3430 	/* Does block tree limit file size? */
3431 	if (res + meta_blocks <= upper_limit)
3432 		goto check_lfs;
3433 
3434 	res = upper_limit;
3435 	/* How many metadata blocks are needed for addressing upper_limit? */
3436 	upper_limit -= EXT4_NDIR_BLOCKS;
3437 	/* indirect blocks */
3438 	meta_blocks = 1;
3439 	upper_limit -= ppb;
3440 	/* double indirect blocks */
3441 	if (upper_limit < ppb * ppb) {
3442 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3443 		res -= meta_blocks;
3444 		goto check_lfs;
3445 	}
3446 	meta_blocks += 1 + ppb;
3447 	upper_limit -= ppb * ppb;
3448 	/* tripple indirect blocks for the rest */
3449 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3450 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3451 	res -= meta_blocks;
3452 check_lfs:
3453 	res <<= bits;
3454 	if (res > MAX_LFS_FILESIZE)
3455 		res = MAX_LFS_FILESIZE;
3456 
3457 	return res;
3458 }
3459 
3460 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3461 				   ext4_fsblk_t logical_sb_block, int nr)
3462 {
3463 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3464 	ext4_group_t bg, first_meta_bg;
3465 	int has_super = 0;
3466 
3467 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3468 
3469 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3470 		return logical_sb_block + nr + 1;
3471 	bg = sbi->s_desc_per_block * nr;
3472 	if (ext4_bg_has_super(sb, bg))
3473 		has_super = 1;
3474 
3475 	/*
3476 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3477 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3478 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3479 	 * compensate.
3480 	 */
3481 	if (sb->s_blocksize == 1024 && nr == 0 &&
3482 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3483 		has_super++;
3484 
3485 	return (has_super + ext4_group_first_block_no(sb, bg));
3486 }
3487 
3488 /**
3489  * ext4_get_stripe_size: Get the stripe size.
3490  * @sbi: In memory super block info
3491  *
3492  * If we have specified it via mount option, then
3493  * use the mount option value. If the value specified at mount time is
3494  * greater than the blocks per group use the super block value.
3495  * If the super block value is greater than blocks per group return 0.
3496  * Allocator needs it be less than blocks per group.
3497  *
3498  */
3499 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3500 {
3501 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3502 	unsigned long stripe_width =
3503 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3504 	int ret;
3505 
3506 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3507 		ret = sbi->s_stripe;
3508 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3509 		ret = stripe_width;
3510 	else if (stride && stride <= sbi->s_blocks_per_group)
3511 		ret = stride;
3512 	else
3513 		ret = 0;
3514 
3515 	/*
3516 	 * If the stripe width is 1, this makes no sense and
3517 	 * we set it to 0 to turn off stripe handling code.
3518 	 */
3519 	if (ret <= 1)
3520 		ret = 0;
3521 
3522 	return ret;
3523 }
3524 
3525 /*
3526  * Check whether this filesystem can be mounted based on
3527  * the features present and the RDONLY/RDWR mount requested.
3528  * Returns 1 if this filesystem can be mounted as requested,
3529  * 0 if it cannot be.
3530  */
3531 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3532 {
3533 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3534 		ext4_msg(sb, KERN_ERR,
3535 			"Couldn't mount because of "
3536 			"unsupported optional features (%x)",
3537 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3538 			~EXT4_FEATURE_INCOMPAT_SUPP));
3539 		return 0;
3540 	}
3541 
3542 #if !IS_ENABLED(CONFIG_UNICODE)
3543 	if (ext4_has_feature_casefold(sb)) {
3544 		ext4_msg(sb, KERN_ERR,
3545 			 "Filesystem with casefold feature cannot be "
3546 			 "mounted without CONFIG_UNICODE");
3547 		return 0;
3548 	}
3549 #endif
3550 
3551 	if (readonly)
3552 		return 1;
3553 
3554 	if (ext4_has_feature_readonly(sb)) {
3555 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3556 		sb->s_flags |= SB_RDONLY;
3557 		return 1;
3558 	}
3559 
3560 	/* Check that feature set is OK for a read-write mount */
3561 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3562 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3563 			 "unsupported optional features (%x)",
3564 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3565 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3566 		return 0;
3567 	}
3568 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3569 		ext4_msg(sb, KERN_ERR,
3570 			 "Can't support bigalloc feature without "
3571 			 "extents feature\n");
3572 		return 0;
3573 	}
3574 
3575 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3576 	if (!readonly && (ext4_has_feature_quota(sb) ||
3577 			  ext4_has_feature_project(sb))) {
3578 		ext4_msg(sb, KERN_ERR,
3579 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3580 		return 0;
3581 	}
3582 #endif  /* CONFIG_QUOTA */
3583 	return 1;
3584 }
3585 
3586 /*
3587  * This function is called once a day if we have errors logged
3588  * on the file system
3589  */
3590 static void print_daily_error_info(struct timer_list *t)
3591 {
3592 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3593 	struct super_block *sb = sbi->s_sb;
3594 	struct ext4_super_block *es = sbi->s_es;
3595 
3596 	if (es->s_error_count)
3597 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3598 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3599 			 le32_to_cpu(es->s_error_count));
3600 	if (es->s_first_error_time) {
3601 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3602 		       sb->s_id,
3603 		       ext4_get_tstamp(es, s_first_error_time),
3604 		       (int) sizeof(es->s_first_error_func),
3605 		       es->s_first_error_func,
3606 		       le32_to_cpu(es->s_first_error_line));
3607 		if (es->s_first_error_ino)
3608 			printk(KERN_CONT ": inode %u",
3609 			       le32_to_cpu(es->s_first_error_ino));
3610 		if (es->s_first_error_block)
3611 			printk(KERN_CONT ": block %llu", (unsigned long long)
3612 			       le64_to_cpu(es->s_first_error_block));
3613 		printk(KERN_CONT "\n");
3614 	}
3615 	if (es->s_last_error_time) {
3616 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3617 		       sb->s_id,
3618 		       ext4_get_tstamp(es, s_last_error_time),
3619 		       (int) sizeof(es->s_last_error_func),
3620 		       es->s_last_error_func,
3621 		       le32_to_cpu(es->s_last_error_line));
3622 		if (es->s_last_error_ino)
3623 			printk(KERN_CONT ": inode %u",
3624 			       le32_to_cpu(es->s_last_error_ino));
3625 		if (es->s_last_error_block)
3626 			printk(KERN_CONT ": block %llu", (unsigned long long)
3627 			       le64_to_cpu(es->s_last_error_block));
3628 		printk(KERN_CONT "\n");
3629 	}
3630 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3631 }
3632 
3633 /* Find next suitable group and run ext4_init_inode_table */
3634 static int ext4_run_li_request(struct ext4_li_request *elr)
3635 {
3636 	struct ext4_group_desc *gdp = NULL;
3637 	struct super_block *sb = elr->lr_super;
3638 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3639 	ext4_group_t group = elr->lr_next_group;
3640 	unsigned int prefetch_ios = 0;
3641 	int ret = 0;
3642 	u64 start_time;
3643 
3644 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3645 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3646 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3647 		if (prefetch_ios)
3648 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3649 					      prefetch_ios);
3650 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3651 					    prefetch_ios);
3652 		if (group >= elr->lr_next_group) {
3653 			ret = 1;
3654 			if (elr->lr_first_not_zeroed != ngroups &&
3655 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3656 				elr->lr_next_group = elr->lr_first_not_zeroed;
3657 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3658 				ret = 0;
3659 			}
3660 		}
3661 		return ret;
3662 	}
3663 
3664 	for (; group < ngroups; group++) {
3665 		gdp = ext4_get_group_desc(sb, group, NULL);
3666 		if (!gdp) {
3667 			ret = 1;
3668 			break;
3669 		}
3670 
3671 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3672 			break;
3673 	}
3674 
3675 	if (group >= ngroups)
3676 		ret = 1;
3677 
3678 	if (!ret) {
3679 		start_time = ktime_get_real_ns();
3680 		ret = ext4_init_inode_table(sb, group,
3681 					    elr->lr_timeout ? 0 : 1);
3682 		trace_ext4_lazy_itable_init(sb, group);
3683 		if (elr->lr_timeout == 0) {
3684 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3685 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3686 		}
3687 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3688 		elr->lr_next_group = group + 1;
3689 	}
3690 	return ret;
3691 }
3692 
3693 /*
3694  * Remove lr_request from the list_request and free the
3695  * request structure. Should be called with li_list_mtx held
3696  */
3697 static void ext4_remove_li_request(struct ext4_li_request *elr)
3698 {
3699 	if (!elr)
3700 		return;
3701 
3702 	list_del(&elr->lr_request);
3703 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3704 	kfree(elr);
3705 }
3706 
3707 static void ext4_unregister_li_request(struct super_block *sb)
3708 {
3709 	mutex_lock(&ext4_li_mtx);
3710 	if (!ext4_li_info) {
3711 		mutex_unlock(&ext4_li_mtx);
3712 		return;
3713 	}
3714 
3715 	mutex_lock(&ext4_li_info->li_list_mtx);
3716 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3717 	mutex_unlock(&ext4_li_info->li_list_mtx);
3718 	mutex_unlock(&ext4_li_mtx);
3719 }
3720 
3721 static struct task_struct *ext4_lazyinit_task;
3722 
3723 /*
3724  * This is the function where ext4lazyinit thread lives. It walks
3725  * through the request list searching for next scheduled filesystem.
3726  * When such a fs is found, run the lazy initialization request
3727  * (ext4_rn_li_request) and keep track of the time spend in this
3728  * function. Based on that time we compute next schedule time of
3729  * the request. When walking through the list is complete, compute
3730  * next waking time and put itself into sleep.
3731  */
3732 static int ext4_lazyinit_thread(void *arg)
3733 {
3734 	struct ext4_lazy_init *eli = arg;
3735 	struct list_head *pos, *n;
3736 	struct ext4_li_request *elr;
3737 	unsigned long next_wakeup, cur;
3738 
3739 	BUG_ON(NULL == eli);
3740 	set_freezable();
3741 
3742 cont_thread:
3743 	while (true) {
3744 		next_wakeup = MAX_JIFFY_OFFSET;
3745 
3746 		mutex_lock(&eli->li_list_mtx);
3747 		if (list_empty(&eli->li_request_list)) {
3748 			mutex_unlock(&eli->li_list_mtx);
3749 			goto exit_thread;
3750 		}
3751 		list_for_each_safe(pos, n, &eli->li_request_list) {
3752 			int err = 0;
3753 			int progress = 0;
3754 			elr = list_entry(pos, struct ext4_li_request,
3755 					 lr_request);
3756 
3757 			if (time_before(jiffies, elr->lr_next_sched)) {
3758 				if (time_before(elr->lr_next_sched, next_wakeup))
3759 					next_wakeup = elr->lr_next_sched;
3760 				continue;
3761 			}
3762 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3763 				if (sb_start_write_trylock(elr->lr_super)) {
3764 					progress = 1;
3765 					/*
3766 					 * We hold sb->s_umount, sb can not
3767 					 * be removed from the list, it is
3768 					 * now safe to drop li_list_mtx
3769 					 */
3770 					mutex_unlock(&eli->li_list_mtx);
3771 					err = ext4_run_li_request(elr);
3772 					sb_end_write(elr->lr_super);
3773 					mutex_lock(&eli->li_list_mtx);
3774 					n = pos->next;
3775 				}
3776 				up_read((&elr->lr_super->s_umount));
3777 			}
3778 			/* error, remove the lazy_init job */
3779 			if (err) {
3780 				ext4_remove_li_request(elr);
3781 				continue;
3782 			}
3783 			if (!progress) {
3784 				elr->lr_next_sched = jiffies +
3785 					prandom_u32_max(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3786 			}
3787 			if (time_before(elr->lr_next_sched, next_wakeup))
3788 				next_wakeup = elr->lr_next_sched;
3789 		}
3790 		mutex_unlock(&eli->li_list_mtx);
3791 
3792 		try_to_freeze();
3793 
3794 		cur = jiffies;
3795 		if ((time_after_eq(cur, next_wakeup)) ||
3796 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3797 			cond_resched();
3798 			continue;
3799 		}
3800 
3801 		schedule_timeout_interruptible(next_wakeup - cur);
3802 
3803 		if (kthread_should_stop()) {
3804 			ext4_clear_request_list();
3805 			goto exit_thread;
3806 		}
3807 	}
3808 
3809 exit_thread:
3810 	/*
3811 	 * It looks like the request list is empty, but we need
3812 	 * to check it under the li_list_mtx lock, to prevent any
3813 	 * additions into it, and of course we should lock ext4_li_mtx
3814 	 * to atomically free the list and ext4_li_info, because at
3815 	 * this point another ext4 filesystem could be registering
3816 	 * new one.
3817 	 */
3818 	mutex_lock(&ext4_li_mtx);
3819 	mutex_lock(&eli->li_list_mtx);
3820 	if (!list_empty(&eli->li_request_list)) {
3821 		mutex_unlock(&eli->li_list_mtx);
3822 		mutex_unlock(&ext4_li_mtx);
3823 		goto cont_thread;
3824 	}
3825 	mutex_unlock(&eli->li_list_mtx);
3826 	kfree(ext4_li_info);
3827 	ext4_li_info = NULL;
3828 	mutex_unlock(&ext4_li_mtx);
3829 
3830 	return 0;
3831 }
3832 
3833 static void ext4_clear_request_list(void)
3834 {
3835 	struct list_head *pos, *n;
3836 	struct ext4_li_request *elr;
3837 
3838 	mutex_lock(&ext4_li_info->li_list_mtx);
3839 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3840 		elr = list_entry(pos, struct ext4_li_request,
3841 				 lr_request);
3842 		ext4_remove_li_request(elr);
3843 	}
3844 	mutex_unlock(&ext4_li_info->li_list_mtx);
3845 }
3846 
3847 static int ext4_run_lazyinit_thread(void)
3848 {
3849 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3850 					 ext4_li_info, "ext4lazyinit");
3851 	if (IS_ERR(ext4_lazyinit_task)) {
3852 		int err = PTR_ERR(ext4_lazyinit_task);
3853 		ext4_clear_request_list();
3854 		kfree(ext4_li_info);
3855 		ext4_li_info = NULL;
3856 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3857 				 "initialization thread\n",
3858 				 err);
3859 		return err;
3860 	}
3861 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3862 	return 0;
3863 }
3864 
3865 /*
3866  * Check whether it make sense to run itable init. thread or not.
3867  * If there is at least one uninitialized inode table, return
3868  * corresponding group number, else the loop goes through all
3869  * groups and return total number of groups.
3870  */
3871 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3872 {
3873 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3874 	struct ext4_group_desc *gdp = NULL;
3875 
3876 	if (!ext4_has_group_desc_csum(sb))
3877 		return ngroups;
3878 
3879 	for (group = 0; group < ngroups; group++) {
3880 		gdp = ext4_get_group_desc(sb, group, NULL);
3881 		if (!gdp)
3882 			continue;
3883 
3884 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3885 			break;
3886 	}
3887 
3888 	return group;
3889 }
3890 
3891 static int ext4_li_info_new(void)
3892 {
3893 	struct ext4_lazy_init *eli = NULL;
3894 
3895 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3896 	if (!eli)
3897 		return -ENOMEM;
3898 
3899 	INIT_LIST_HEAD(&eli->li_request_list);
3900 	mutex_init(&eli->li_list_mtx);
3901 
3902 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3903 
3904 	ext4_li_info = eli;
3905 
3906 	return 0;
3907 }
3908 
3909 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3910 					    ext4_group_t start)
3911 {
3912 	struct ext4_li_request *elr;
3913 
3914 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3915 	if (!elr)
3916 		return NULL;
3917 
3918 	elr->lr_super = sb;
3919 	elr->lr_first_not_zeroed = start;
3920 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3921 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3922 		elr->lr_next_group = start;
3923 	} else {
3924 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3925 	}
3926 
3927 	/*
3928 	 * Randomize first schedule time of the request to
3929 	 * spread the inode table initialization requests
3930 	 * better.
3931 	 */
3932 	elr->lr_next_sched = jiffies + prandom_u32_max(
3933 				EXT4_DEF_LI_MAX_START_DELAY * HZ);
3934 	return elr;
3935 }
3936 
3937 int ext4_register_li_request(struct super_block *sb,
3938 			     ext4_group_t first_not_zeroed)
3939 {
3940 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3941 	struct ext4_li_request *elr = NULL;
3942 	ext4_group_t ngroups = sbi->s_groups_count;
3943 	int ret = 0;
3944 
3945 	mutex_lock(&ext4_li_mtx);
3946 	if (sbi->s_li_request != NULL) {
3947 		/*
3948 		 * Reset timeout so it can be computed again, because
3949 		 * s_li_wait_mult might have changed.
3950 		 */
3951 		sbi->s_li_request->lr_timeout = 0;
3952 		goto out;
3953 	}
3954 
3955 	if (sb_rdonly(sb) ||
3956 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3957 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
3958 		goto out;
3959 
3960 	elr = ext4_li_request_new(sb, first_not_zeroed);
3961 	if (!elr) {
3962 		ret = -ENOMEM;
3963 		goto out;
3964 	}
3965 
3966 	if (NULL == ext4_li_info) {
3967 		ret = ext4_li_info_new();
3968 		if (ret)
3969 			goto out;
3970 	}
3971 
3972 	mutex_lock(&ext4_li_info->li_list_mtx);
3973 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3974 	mutex_unlock(&ext4_li_info->li_list_mtx);
3975 
3976 	sbi->s_li_request = elr;
3977 	/*
3978 	 * set elr to NULL here since it has been inserted to
3979 	 * the request_list and the removal and free of it is
3980 	 * handled by ext4_clear_request_list from now on.
3981 	 */
3982 	elr = NULL;
3983 
3984 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3985 		ret = ext4_run_lazyinit_thread();
3986 		if (ret)
3987 			goto out;
3988 	}
3989 out:
3990 	mutex_unlock(&ext4_li_mtx);
3991 	if (ret)
3992 		kfree(elr);
3993 	return ret;
3994 }
3995 
3996 /*
3997  * We do not need to lock anything since this is called on
3998  * module unload.
3999  */
4000 static void ext4_destroy_lazyinit_thread(void)
4001 {
4002 	/*
4003 	 * If thread exited earlier
4004 	 * there's nothing to be done.
4005 	 */
4006 	if (!ext4_li_info || !ext4_lazyinit_task)
4007 		return;
4008 
4009 	kthread_stop(ext4_lazyinit_task);
4010 }
4011 
4012 static int set_journal_csum_feature_set(struct super_block *sb)
4013 {
4014 	int ret = 1;
4015 	int compat, incompat;
4016 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4017 
4018 	if (ext4_has_metadata_csum(sb)) {
4019 		/* journal checksum v3 */
4020 		compat = 0;
4021 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4022 	} else {
4023 		/* journal checksum v1 */
4024 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4025 		incompat = 0;
4026 	}
4027 
4028 	jbd2_journal_clear_features(sbi->s_journal,
4029 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4030 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4031 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4032 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4033 		ret = jbd2_journal_set_features(sbi->s_journal,
4034 				compat, 0,
4035 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4036 				incompat);
4037 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4038 		ret = jbd2_journal_set_features(sbi->s_journal,
4039 				compat, 0,
4040 				incompat);
4041 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4042 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4043 	} else {
4044 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4045 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4046 	}
4047 
4048 	return ret;
4049 }
4050 
4051 /*
4052  * Note: calculating the overhead so we can be compatible with
4053  * historical BSD practice is quite difficult in the face of
4054  * clusters/bigalloc.  This is because multiple metadata blocks from
4055  * different block group can end up in the same allocation cluster.
4056  * Calculating the exact overhead in the face of clustered allocation
4057  * requires either O(all block bitmaps) in memory or O(number of block
4058  * groups**2) in time.  We will still calculate the superblock for
4059  * older file systems --- and if we come across with a bigalloc file
4060  * system with zero in s_overhead_clusters the estimate will be close to
4061  * correct especially for very large cluster sizes --- but for newer
4062  * file systems, it's better to calculate this figure once at mkfs
4063  * time, and store it in the superblock.  If the superblock value is
4064  * present (even for non-bigalloc file systems), we will use it.
4065  */
4066 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4067 			  char *buf)
4068 {
4069 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4070 	struct ext4_group_desc	*gdp;
4071 	ext4_fsblk_t		first_block, last_block, b;
4072 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4073 	int			s, j, count = 0;
4074 	int			has_super = ext4_bg_has_super(sb, grp);
4075 
4076 	if (!ext4_has_feature_bigalloc(sb))
4077 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4078 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4079 			sbi->s_itb_per_group + 2);
4080 
4081 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4082 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4083 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4084 	for (i = 0; i < ngroups; i++) {
4085 		gdp = ext4_get_group_desc(sb, i, NULL);
4086 		b = ext4_block_bitmap(sb, gdp);
4087 		if (b >= first_block && b <= last_block) {
4088 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4089 			count++;
4090 		}
4091 		b = ext4_inode_bitmap(sb, gdp);
4092 		if (b >= first_block && b <= last_block) {
4093 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4094 			count++;
4095 		}
4096 		b = ext4_inode_table(sb, gdp);
4097 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4098 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4099 				int c = EXT4_B2C(sbi, b - first_block);
4100 				ext4_set_bit(c, buf);
4101 				count++;
4102 			}
4103 		if (i != grp)
4104 			continue;
4105 		s = 0;
4106 		if (ext4_bg_has_super(sb, grp)) {
4107 			ext4_set_bit(s++, buf);
4108 			count++;
4109 		}
4110 		j = ext4_bg_num_gdb(sb, grp);
4111 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4112 			ext4_error(sb, "Invalid number of block group "
4113 				   "descriptor blocks: %d", j);
4114 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4115 		}
4116 		count += j;
4117 		for (; j > 0; j--)
4118 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4119 	}
4120 	if (!count)
4121 		return 0;
4122 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4123 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4124 }
4125 
4126 /*
4127  * Compute the overhead and stash it in sbi->s_overhead
4128  */
4129 int ext4_calculate_overhead(struct super_block *sb)
4130 {
4131 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4132 	struct ext4_super_block *es = sbi->s_es;
4133 	struct inode *j_inode;
4134 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4135 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4136 	ext4_fsblk_t overhead = 0;
4137 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4138 
4139 	if (!buf)
4140 		return -ENOMEM;
4141 
4142 	/*
4143 	 * Compute the overhead (FS structures).  This is constant
4144 	 * for a given filesystem unless the number of block groups
4145 	 * changes so we cache the previous value until it does.
4146 	 */
4147 
4148 	/*
4149 	 * All of the blocks before first_data_block are overhead
4150 	 */
4151 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4152 
4153 	/*
4154 	 * Add the overhead found in each block group
4155 	 */
4156 	for (i = 0; i < ngroups; i++) {
4157 		int blks;
4158 
4159 		blks = count_overhead(sb, i, buf);
4160 		overhead += blks;
4161 		if (blks)
4162 			memset(buf, 0, PAGE_SIZE);
4163 		cond_resched();
4164 	}
4165 
4166 	/*
4167 	 * Add the internal journal blocks whether the journal has been
4168 	 * loaded or not
4169 	 */
4170 	if (sbi->s_journal && !sbi->s_journal_bdev)
4171 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4172 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4173 		/* j_inum for internal journal is non-zero */
4174 		j_inode = ext4_get_journal_inode(sb, j_inum);
4175 		if (j_inode) {
4176 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4177 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4178 			iput(j_inode);
4179 		} else {
4180 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4181 		}
4182 	}
4183 	sbi->s_overhead = overhead;
4184 	smp_wmb();
4185 	free_page((unsigned long) buf);
4186 	return 0;
4187 }
4188 
4189 static void ext4_set_resv_clusters(struct super_block *sb)
4190 {
4191 	ext4_fsblk_t resv_clusters;
4192 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4193 
4194 	/*
4195 	 * There's no need to reserve anything when we aren't using extents.
4196 	 * The space estimates are exact, there are no unwritten extents,
4197 	 * hole punching doesn't need new metadata... This is needed especially
4198 	 * to keep ext2/3 backward compatibility.
4199 	 */
4200 	if (!ext4_has_feature_extents(sb))
4201 		return;
4202 	/*
4203 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4204 	 * This should cover the situations where we can not afford to run
4205 	 * out of space like for example punch hole, or converting
4206 	 * unwritten extents in delalloc path. In most cases such
4207 	 * allocation would require 1, or 2 blocks, higher numbers are
4208 	 * very rare.
4209 	 */
4210 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4211 			 sbi->s_cluster_bits);
4212 
4213 	do_div(resv_clusters, 50);
4214 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4215 
4216 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4217 }
4218 
4219 static const char *ext4_quota_mode(struct super_block *sb)
4220 {
4221 #ifdef CONFIG_QUOTA
4222 	if (!ext4_quota_capable(sb))
4223 		return "none";
4224 
4225 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4226 		return "journalled";
4227 	else
4228 		return "writeback";
4229 #else
4230 	return "disabled";
4231 #endif
4232 }
4233 
4234 static void ext4_setup_csum_trigger(struct super_block *sb,
4235 				    enum ext4_journal_trigger_type type,
4236 				    void (*trigger)(
4237 					struct jbd2_buffer_trigger_type *type,
4238 					struct buffer_head *bh,
4239 					void *mapped_data,
4240 					size_t size))
4241 {
4242 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4243 
4244 	sbi->s_journal_triggers[type].sb = sb;
4245 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4246 }
4247 
4248 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4249 {
4250 	if (!sbi)
4251 		return;
4252 
4253 	kfree(sbi->s_blockgroup_lock);
4254 	fs_put_dax(sbi->s_daxdev, NULL);
4255 	kfree(sbi);
4256 }
4257 
4258 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4259 {
4260 	struct ext4_sb_info *sbi;
4261 
4262 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4263 	if (!sbi)
4264 		return NULL;
4265 
4266 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4267 					   NULL, NULL);
4268 
4269 	sbi->s_blockgroup_lock =
4270 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4271 
4272 	if (!sbi->s_blockgroup_lock)
4273 		goto err_out;
4274 
4275 	sb->s_fs_info = sbi;
4276 	sbi->s_sb = sb;
4277 	return sbi;
4278 err_out:
4279 	fs_put_dax(sbi->s_daxdev, NULL);
4280 	kfree(sbi);
4281 	return NULL;
4282 }
4283 
4284 static void ext4_set_def_opts(struct super_block *sb,
4285 			      struct ext4_super_block *es)
4286 {
4287 	unsigned long def_mount_opts;
4288 
4289 	/* Set defaults before we parse the mount options */
4290 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4291 	set_opt(sb, INIT_INODE_TABLE);
4292 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4293 		set_opt(sb, DEBUG);
4294 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4295 		set_opt(sb, GRPID);
4296 	if (def_mount_opts & EXT4_DEFM_UID16)
4297 		set_opt(sb, NO_UID32);
4298 	/* xattr user namespace & acls are now defaulted on */
4299 	set_opt(sb, XATTR_USER);
4300 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4301 	set_opt(sb, POSIX_ACL);
4302 #endif
4303 	if (ext4_has_feature_fast_commit(sb))
4304 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4305 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4306 	if (ext4_has_metadata_csum(sb))
4307 		set_opt(sb, JOURNAL_CHECKSUM);
4308 
4309 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4310 		set_opt(sb, JOURNAL_DATA);
4311 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4312 		set_opt(sb, ORDERED_DATA);
4313 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4314 		set_opt(sb, WRITEBACK_DATA);
4315 
4316 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4317 		set_opt(sb, ERRORS_PANIC);
4318 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4319 		set_opt(sb, ERRORS_CONT);
4320 	else
4321 		set_opt(sb, ERRORS_RO);
4322 	/* block_validity enabled by default; disable with noblock_validity */
4323 	set_opt(sb, BLOCK_VALIDITY);
4324 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4325 		set_opt(sb, DISCARD);
4326 
4327 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4328 		set_opt(sb, BARRIER);
4329 
4330 	/*
4331 	 * enable delayed allocation by default
4332 	 * Use -o nodelalloc to turn it off
4333 	 */
4334 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4335 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4336 		set_opt(sb, DELALLOC);
4337 
4338 	if (sb->s_blocksize == PAGE_SIZE)
4339 		set_opt(sb, DIOREAD_NOLOCK);
4340 }
4341 
4342 static int ext4_handle_clustersize(struct super_block *sb)
4343 {
4344 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4345 	struct ext4_super_block *es = sbi->s_es;
4346 	int clustersize;
4347 
4348 	/* Handle clustersize */
4349 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4350 	if (ext4_has_feature_bigalloc(sb)) {
4351 		if (clustersize < sb->s_blocksize) {
4352 			ext4_msg(sb, KERN_ERR,
4353 				 "cluster size (%d) smaller than "
4354 				 "block size (%lu)", clustersize, sb->s_blocksize);
4355 			return -EINVAL;
4356 		}
4357 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4358 			le32_to_cpu(es->s_log_block_size);
4359 		sbi->s_clusters_per_group =
4360 			le32_to_cpu(es->s_clusters_per_group);
4361 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4362 			ext4_msg(sb, KERN_ERR,
4363 				 "#clusters per group too big: %lu",
4364 				 sbi->s_clusters_per_group);
4365 			return -EINVAL;
4366 		}
4367 		if (sbi->s_blocks_per_group !=
4368 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4369 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4370 				 "clusters per group (%lu) inconsistent",
4371 				 sbi->s_blocks_per_group,
4372 				 sbi->s_clusters_per_group);
4373 			return -EINVAL;
4374 		}
4375 	} else {
4376 		if (clustersize != sb->s_blocksize) {
4377 			ext4_msg(sb, KERN_ERR,
4378 				 "fragment/cluster size (%d) != "
4379 				 "block size (%lu)", clustersize, sb->s_blocksize);
4380 			return -EINVAL;
4381 		}
4382 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4383 			ext4_msg(sb, KERN_ERR,
4384 				 "#blocks per group too big: %lu",
4385 				 sbi->s_blocks_per_group);
4386 			return -EINVAL;
4387 		}
4388 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4389 		sbi->s_cluster_bits = 0;
4390 	}
4391 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4392 
4393 	/* Do we have standard group size of clustersize * 8 blocks ? */
4394 	if (sbi->s_blocks_per_group == clustersize << 3)
4395 		set_opt2(sb, STD_GROUP_SIZE);
4396 
4397 	return 0;
4398 }
4399 
4400 static void ext4_fast_commit_init(struct super_block *sb)
4401 {
4402 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4403 
4404 	/* Initialize fast commit stuff */
4405 	atomic_set(&sbi->s_fc_subtid, 0);
4406 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4407 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4408 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4409 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4410 	sbi->s_fc_bytes = 0;
4411 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4412 	sbi->s_fc_ineligible_tid = 0;
4413 	spin_lock_init(&sbi->s_fc_lock);
4414 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4415 	sbi->s_fc_replay_state.fc_regions = NULL;
4416 	sbi->s_fc_replay_state.fc_regions_size = 0;
4417 	sbi->s_fc_replay_state.fc_regions_used = 0;
4418 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4419 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4420 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4421 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4422 }
4423 
4424 static int ext4_inode_info_init(struct super_block *sb,
4425 				struct ext4_super_block *es)
4426 {
4427 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4428 
4429 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4430 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4431 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4432 	} else {
4433 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4434 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4435 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4436 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4437 				 sbi->s_first_ino);
4438 			return -EINVAL;
4439 		}
4440 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4441 		    (!is_power_of_2(sbi->s_inode_size)) ||
4442 		    (sbi->s_inode_size > sb->s_blocksize)) {
4443 			ext4_msg(sb, KERN_ERR,
4444 			       "unsupported inode size: %d",
4445 			       sbi->s_inode_size);
4446 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4447 			return -EINVAL;
4448 		}
4449 		/*
4450 		 * i_atime_extra is the last extra field available for
4451 		 * [acm]times in struct ext4_inode. Checking for that
4452 		 * field should suffice to ensure we have extra space
4453 		 * for all three.
4454 		 */
4455 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4456 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4457 			sb->s_time_gran = 1;
4458 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4459 		} else {
4460 			sb->s_time_gran = NSEC_PER_SEC;
4461 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4462 		}
4463 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4464 	}
4465 
4466 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4467 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4468 			EXT4_GOOD_OLD_INODE_SIZE;
4469 		if (ext4_has_feature_extra_isize(sb)) {
4470 			unsigned v, max = (sbi->s_inode_size -
4471 					   EXT4_GOOD_OLD_INODE_SIZE);
4472 
4473 			v = le16_to_cpu(es->s_want_extra_isize);
4474 			if (v > max) {
4475 				ext4_msg(sb, KERN_ERR,
4476 					 "bad s_want_extra_isize: %d", v);
4477 				return -EINVAL;
4478 			}
4479 			if (sbi->s_want_extra_isize < v)
4480 				sbi->s_want_extra_isize = v;
4481 
4482 			v = le16_to_cpu(es->s_min_extra_isize);
4483 			if (v > max) {
4484 				ext4_msg(sb, KERN_ERR,
4485 					 "bad s_min_extra_isize: %d", v);
4486 				return -EINVAL;
4487 			}
4488 			if (sbi->s_want_extra_isize < v)
4489 				sbi->s_want_extra_isize = v;
4490 		}
4491 	}
4492 
4493 	return 0;
4494 }
4495 
4496 #if IS_ENABLED(CONFIG_UNICODE)
4497 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4498 {
4499 	const struct ext4_sb_encodings *encoding_info;
4500 	struct unicode_map *encoding;
4501 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4502 
4503 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4504 		return 0;
4505 
4506 	encoding_info = ext4_sb_read_encoding(es);
4507 	if (!encoding_info) {
4508 		ext4_msg(sb, KERN_ERR,
4509 			"Encoding requested by superblock is unknown");
4510 		return -EINVAL;
4511 	}
4512 
4513 	encoding = utf8_load(encoding_info->version);
4514 	if (IS_ERR(encoding)) {
4515 		ext4_msg(sb, KERN_ERR,
4516 			"can't mount with superblock charset: %s-%u.%u.%u "
4517 			"not supported by the kernel. flags: 0x%x.",
4518 			encoding_info->name,
4519 			unicode_major(encoding_info->version),
4520 			unicode_minor(encoding_info->version),
4521 			unicode_rev(encoding_info->version),
4522 			encoding_flags);
4523 		return -EINVAL;
4524 	}
4525 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4526 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4527 		unicode_major(encoding_info->version),
4528 		unicode_minor(encoding_info->version),
4529 		unicode_rev(encoding_info->version),
4530 		encoding_flags);
4531 
4532 	sb->s_encoding = encoding;
4533 	sb->s_encoding_flags = encoding_flags;
4534 
4535 	return 0;
4536 }
4537 #else
4538 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4539 {
4540 	return 0;
4541 }
4542 #endif
4543 
4544 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4545 {
4546 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4547 
4548 	/* Warn if metadata_csum and gdt_csum are both set. */
4549 	if (ext4_has_feature_metadata_csum(sb) &&
4550 	    ext4_has_feature_gdt_csum(sb))
4551 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4552 			     "redundant flags; please run fsck.");
4553 
4554 	/* Check for a known checksum algorithm */
4555 	if (!ext4_verify_csum_type(sb, es)) {
4556 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4557 			 "unknown checksum algorithm.");
4558 		return -EINVAL;
4559 	}
4560 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4561 				ext4_orphan_file_block_trigger);
4562 
4563 	/* Load the checksum driver */
4564 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4565 	if (IS_ERR(sbi->s_chksum_driver)) {
4566 		int ret = PTR_ERR(sbi->s_chksum_driver);
4567 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4568 		sbi->s_chksum_driver = NULL;
4569 		return ret;
4570 	}
4571 
4572 	/* Check superblock checksum */
4573 	if (!ext4_superblock_csum_verify(sb, es)) {
4574 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4575 			 "invalid superblock checksum.  Run e2fsck?");
4576 		return -EFSBADCRC;
4577 	}
4578 
4579 	/* Precompute checksum seed for all metadata */
4580 	if (ext4_has_feature_csum_seed(sb))
4581 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4582 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4583 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4584 					       sizeof(es->s_uuid));
4585 	return 0;
4586 }
4587 
4588 static int ext4_check_feature_compatibility(struct super_block *sb,
4589 					    struct ext4_super_block *es,
4590 					    int silent)
4591 {
4592 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4593 	    (ext4_has_compat_features(sb) ||
4594 	     ext4_has_ro_compat_features(sb) ||
4595 	     ext4_has_incompat_features(sb)))
4596 		ext4_msg(sb, KERN_WARNING,
4597 		       "feature flags set on rev 0 fs, "
4598 		       "running e2fsck is recommended");
4599 
4600 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4601 		set_opt2(sb, HURD_COMPAT);
4602 		if (ext4_has_feature_64bit(sb)) {
4603 			ext4_msg(sb, KERN_ERR,
4604 				 "The Hurd can't support 64-bit file systems");
4605 			return -EINVAL;
4606 		}
4607 
4608 		/*
4609 		 * ea_inode feature uses l_i_version field which is not
4610 		 * available in HURD_COMPAT mode.
4611 		 */
4612 		if (ext4_has_feature_ea_inode(sb)) {
4613 			ext4_msg(sb, KERN_ERR,
4614 				 "ea_inode feature is not supported for Hurd");
4615 			return -EINVAL;
4616 		}
4617 	}
4618 
4619 	if (IS_EXT2_SB(sb)) {
4620 		if (ext2_feature_set_ok(sb))
4621 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4622 				 "using the ext4 subsystem");
4623 		else {
4624 			/*
4625 			 * If we're probing be silent, if this looks like
4626 			 * it's actually an ext[34] filesystem.
4627 			 */
4628 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4629 				return -EINVAL;
4630 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4631 				 "to feature incompatibilities");
4632 			return -EINVAL;
4633 		}
4634 	}
4635 
4636 	if (IS_EXT3_SB(sb)) {
4637 		if (ext3_feature_set_ok(sb))
4638 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4639 				 "using the ext4 subsystem");
4640 		else {
4641 			/*
4642 			 * If we're probing be silent, if this looks like
4643 			 * it's actually an ext4 filesystem.
4644 			 */
4645 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4646 				return -EINVAL;
4647 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4648 				 "to feature incompatibilities");
4649 			return -EINVAL;
4650 		}
4651 	}
4652 
4653 	/*
4654 	 * Check feature flags regardless of the revision level, since we
4655 	 * previously didn't change the revision level when setting the flags,
4656 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4657 	 */
4658 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4659 		return -EINVAL;
4660 
4661 	return 0;
4662 }
4663 
4664 static int ext4_geometry_check(struct super_block *sb,
4665 			       struct ext4_super_block *es)
4666 {
4667 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4668 	__u64 blocks_count;
4669 
4670 	/* check blocks count against device size */
4671 	blocks_count = sb_bdev_nr_blocks(sb);
4672 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4673 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4674 		       "exceeds size of device (%llu blocks)",
4675 		       ext4_blocks_count(es), blocks_count);
4676 		return -EINVAL;
4677 	}
4678 
4679 	/*
4680 	 * It makes no sense for the first data block to be beyond the end
4681 	 * of the filesystem.
4682 	 */
4683 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4684 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4685 			 "block %u is beyond end of filesystem (%llu)",
4686 			 le32_to_cpu(es->s_first_data_block),
4687 			 ext4_blocks_count(es));
4688 		return -EINVAL;
4689 	}
4690 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4691 	    (sbi->s_cluster_ratio == 1)) {
4692 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4693 			 "block is 0 with a 1k block and cluster size");
4694 		return -EINVAL;
4695 	}
4696 
4697 	blocks_count = (ext4_blocks_count(es) -
4698 			le32_to_cpu(es->s_first_data_block) +
4699 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4700 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4701 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4702 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4703 		       "(block count %llu, first data block %u, "
4704 		       "blocks per group %lu)", blocks_count,
4705 		       ext4_blocks_count(es),
4706 		       le32_to_cpu(es->s_first_data_block),
4707 		       EXT4_BLOCKS_PER_GROUP(sb));
4708 		return -EINVAL;
4709 	}
4710 	sbi->s_groups_count = blocks_count;
4711 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4712 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4713 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4714 	    le32_to_cpu(es->s_inodes_count)) {
4715 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4716 			 le32_to_cpu(es->s_inodes_count),
4717 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4718 		return -EINVAL;
4719 	}
4720 
4721 	return 0;
4722 }
4723 
4724 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
4725 {
4726 	struct buffer_head **group_desc;
4727 	int i;
4728 
4729 	rcu_read_lock();
4730 	group_desc = rcu_dereference(sbi->s_group_desc);
4731 	for (i = 0; i < sbi->s_gdb_count; i++)
4732 		brelse(group_desc[i]);
4733 	kvfree(group_desc);
4734 	rcu_read_unlock();
4735 }
4736 
4737 static int ext4_group_desc_init(struct super_block *sb,
4738 				struct ext4_super_block *es,
4739 				ext4_fsblk_t logical_sb_block,
4740 				ext4_group_t *first_not_zeroed)
4741 {
4742 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4743 	unsigned int db_count;
4744 	ext4_fsblk_t block;
4745 	int ret;
4746 	int i;
4747 
4748 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4749 		   EXT4_DESC_PER_BLOCK(sb);
4750 	if (ext4_has_feature_meta_bg(sb)) {
4751 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4752 			ext4_msg(sb, KERN_WARNING,
4753 				 "first meta block group too large: %u "
4754 				 "(group descriptor block count %u)",
4755 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4756 			return -EINVAL;
4757 		}
4758 	}
4759 	rcu_assign_pointer(sbi->s_group_desc,
4760 			   kvmalloc_array(db_count,
4761 					  sizeof(struct buffer_head *),
4762 					  GFP_KERNEL));
4763 	if (sbi->s_group_desc == NULL) {
4764 		ext4_msg(sb, KERN_ERR, "not enough memory");
4765 		return -ENOMEM;
4766 	}
4767 
4768 	bgl_lock_init(sbi->s_blockgroup_lock);
4769 
4770 	/* Pre-read the descriptors into the buffer cache */
4771 	for (i = 0; i < db_count; i++) {
4772 		block = descriptor_loc(sb, logical_sb_block, i);
4773 		ext4_sb_breadahead_unmovable(sb, block);
4774 	}
4775 
4776 	for (i = 0; i < db_count; i++) {
4777 		struct buffer_head *bh;
4778 
4779 		block = descriptor_loc(sb, logical_sb_block, i);
4780 		bh = ext4_sb_bread_unmovable(sb, block);
4781 		if (IS_ERR(bh)) {
4782 			ext4_msg(sb, KERN_ERR,
4783 			       "can't read group descriptor %d", i);
4784 			sbi->s_gdb_count = i;
4785 			ret = PTR_ERR(bh);
4786 			goto out;
4787 		}
4788 		rcu_read_lock();
4789 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4790 		rcu_read_unlock();
4791 	}
4792 	sbi->s_gdb_count = db_count;
4793 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4794 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4795 		ret = -EFSCORRUPTED;
4796 		goto out;
4797 	}
4798 	return 0;
4799 out:
4800 	ext4_group_desc_free(sbi);
4801 	return ret;
4802 }
4803 
4804 static int ext4_load_and_init_journal(struct super_block *sb,
4805 				      struct ext4_super_block *es,
4806 				      struct ext4_fs_context *ctx)
4807 {
4808 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4809 	int err;
4810 
4811 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4812 	if (err)
4813 		return err;
4814 
4815 	if (ext4_has_feature_64bit(sb) &&
4816 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4817 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4818 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4819 		goto out;
4820 	}
4821 
4822 	if (!set_journal_csum_feature_set(sb)) {
4823 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4824 			 "feature set");
4825 		goto out;
4826 	}
4827 
4828 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4829 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4830 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4831 		ext4_msg(sb, KERN_ERR,
4832 			"Failed to set fast commit journal feature");
4833 		goto out;
4834 	}
4835 
4836 	/* We have now updated the journal if required, so we can
4837 	 * validate the data journaling mode. */
4838 	switch (test_opt(sb, DATA_FLAGS)) {
4839 	case 0:
4840 		/* No mode set, assume a default based on the journal
4841 		 * capabilities: ORDERED_DATA if the journal can
4842 		 * cope, else JOURNAL_DATA
4843 		 */
4844 		if (jbd2_journal_check_available_features
4845 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4846 			set_opt(sb, ORDERED_DATA);
4847 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4848 		} else {
4849 			set_opt(sb, JOURNAL_DATA);
4850 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4851 		}
4852 		break;
4853 
4854 	case EXT4_MOUNT_ORDERED_DATA:
4855 	case EXT4_MOUNT_WRITEBACK_DATA:
4856 		if (!jbd2_journal_check_available_features
4857 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4858 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4859 			       "requested data journaling mode");
4860 			goto out;
4861 		}
4862 		break;
4863 	default:
4864 		break;
4865 	}
4866 
4867 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4868 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4869 		ext4_msg(sb, KERN_ERR, "can't mount with "
4870 			"journal_async_commit in data=ordered mode");
4871 		goto out;
4872 	}
4873 
4874 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4875 
4876 	sbi->s_journal->j_submit_inode_data_buffers =
4877 		ext4_journal_submit_inode_data_buffers;
4878 	sbi->s_journal->j_finish_inode_data_buffers =
4879 		ext4_journal_finish_inode_data_buffers;
4880 
4881 	return 0;
4882 
4883 out:
4884 	/* flush s_error_work before journal destroy. */
4885 	flush_work(&sbi->s_error_work);
4886 	jbd2_journal_destroy(sbi->s_journal);
4887 	sbi->s_journal = NULL;
4888 	return err;
4889 }
4890 
4891 static int ext4_journal_data_mode_check(struct super_block *sb)
4892 {
4893 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4894 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4895 			    "data=journal disables delayed allocation, "
4896 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4897 		/* can't mount with both data=journal and dioread_nolock. */
4898 		clear_opt(sb, DIOREAD_NOLOCK);
4899 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4900 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4901 			ext4_msg(sb, KERN_ERR, "can't mount with "
4902 				 "both data=journal and delalloc");
4903 			return -EINVAL;
4904 		}
4905 		if (test_opt(sb, DAX_ALWAYS)) {
4906 			ext4_msg(sb, KERN_ERR, "can't mount with "
4907 				 "both data=journal and dax");
4908 			return -EINVAL;
4909 		}
4910 		if (ext4_has_feature_encrypt(sb)) {
4911 			ext4_msg(sb, KERN_WARNING,
4912 				 "encrypted files will use data=ordered "
4913 				 "instead of data journaling mode");
4914 		}
4915 		if (test_opt(sb, DELALLOC))
4916 			clear_opt(sb, DELALLOC);
4917 	} else {
4918 		sb->s_iflags |= SB_I_CGROUPWB;
4919 	}
4920 
4921 	return 0;
4922 }
4923 
4924 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
4925 			   int silent)
4926 {
4927 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4928 	struct ext4_super_block *es;
4929 	ext4_fsblk_t logical_sb_block;
4930 	unsigned long offset = 0;
4931 	struct buffer_head *bh;
4932 	int ret = -EINVAL;
4933 	int blocksize;
4934 
4935 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4936 	if (!blocksize) {
4937 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4938 		return -EINVAL;
4939 	}
4940 
4941 	/*
4942 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4943 	 * block sizes.  We need to calculate the offset from buffer start.
4944 	 */
4945 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4946 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4947 		offset = do_div(logical_sb_block, blocksize);
4948 	} else {
4949 		logical_sb_block = sbi->s_sb_block;
4950 	}
4951 
4952 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4953 	if (IS_ERR(bh)) {
4954 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4955 		return PTR_ERR(bh);
4956 	}
4957 	/*
4958 	 * Note: s_es must be initialized as soon as possible because
4959 	 *       some ext4 macro-instructions depend on its value
4960 	 */
4961 	es = (struct ext4_super_block *) (bh->b_data + offset);
4962 	sbi->s_es = es;
4963 	sb->s_magic = le16_to_cpu(es->s_magic);
4964 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
4965 		if (!silent)
4966 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4967 		goto out;
4968 	}
4969 
4970 	if (le32_to_cpu(es->s_log_block_size) >
4971 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4972 		ext4_msg(sb, KERN_ERR,
4973 			 "Invalid log block size: %u",
4974 			 le32_to_cpu(es->s_log_block_size));
4975 		goto out;
4976 	}
4977 	if (le32_to_cpu(es->s_log_cluster_size) >
4978 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4979 		ext4_msg(sb, KERN_ERR,
4980 			 "Invalid log cluster size: %u",
4981 			 le32_to_cpu(es->s_log_cluster_size));
4982 		goto out;
4983 	}
4984 
4985 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4986 
4987 	/*
4988 	 * If the default block size is not the same as the real block size,
4989 	 * we need to reload it.
4990 	 */
4991 	if (sb->s_blocksize == blocksize) {
4992 		*lsb = logical_sb_block;
4993 		sbi->s_sbh = bh;
4994 		return 0;
4995 	}
4996 
4997 	/*
4998 	 * bh must be released before kill_bdev(), otherwise
4999 	 * it won't be freed and its page also. kill_bdev()
5000 	 * is called by sb_set_blocksize().
5001 	 */
5002 	brelse(bh);
5003 	/* Validate the filesystem blocksize */
5004 	if (!sb_set_blocksize(sb, blocksize)) {
5005 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5006 				blocksize);
5007 		bh = NULL;
5008 		goto out;
5009 	}
5010 
5011 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5012 	offset = do_div(logical_sb_block, blocksize);
5013 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5014 	if (IS_ERR(bh)) {
5015 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5016 		ret = PTR_ERR(bh);
5017 		bh = NULL;
5018 		goto out;
5019 	}
5020 	es = (struct ext4_super_block *)(bh->b_data + offset);
5021 	sbi->s_es = es;
5022 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5023 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5024 		goto out;
5025 	}
5026 	*lsb = logical_sb_block;
5027 	sbi->s_sbh = bh;
5028 	return 0;
5029 out:
5030 	brelse(bh);
5031 	return ret;
5032 }
5033 
5034 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5035 {
5036 	struct ext4_super_block *es = NULL;
5037 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5038 	struct flex_groups **flex_groups;
5039 	ext4_fsblk_t block;
5040 	ext4_fsblk_t logical_sb_block;
5041 	struct inode *root;
5042 	int ret = -ENOMEM;
5043 	unsigned int i;
5044 	int needs_recovery, has_huge_files;
5045 	int err = 0;
5046 	ext4_group_t first_not_zeroed;
5047 	struct ext4_fs_context *ctx = fc->fs_private;
5048 	int silent = fc->sb_flags & SB_SILENT;
5049 
5050 	/* Set defaults for the variables that will be set during parsing */
5051 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5052 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5053 
5054 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5055 	sbi->s_sectors_written_start =
5056 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5057 
5058 	/* -EINVAL is default */
5059 	ret = -EINVAL;
5060 	err = ext4_load_super(sb, &logical_sb_block, silent);
5061 	if (err)
5062 		goto out_fail;
5063 
5064 	es = sbi->s_es;
5065 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5066 
5067 	err = ext4_init_metadata_csum(sb, es);
5068 	if (err)
5069 		goto failed_mount;
5070 
5071 	ext4_set_def_opts(sb, es);
5072 
5073 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5074 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5075 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5076 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5077 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5078 
5079 	/*
5080 	 * set default s_li_wait_mult for lazyinit, for the case there is
5081 	 * no mount option specified.
5082 	 */
5083 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5084 
5085 	if (ext4_inode_info_init(sb, es))
5086 		goto failed_mount;
5087 
5088 	err = parse_apply_sb_mount_options(sb, ctx);
5089 	if (err < 0)
5090 		goto failed_mount;
5091 
5092 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5093 
5094 	err = ext4_check_opt_consistency(fc, sb);
5095 	if (err < 0)
5096 		goto failed_mount;
5097 
5098 	ext4_apply_options(fc, sb);
5099 
5100 	if (ext4_encoding_init(sb, es))
5101 		goto failed_mount;
5102 
5103 	if (ext4_journal_data_mode_check(sb))
5104 		goto failed_mount;
5105 
5106 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5107 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5108 
5109 	/* i_version is always enabled now */
5110 	sb->s_flags |= SB_I_VERSION;
5111 
5112 	if (ext4_check_feature_compatibility(sb, es, silent))
5113 		goto failed_mount;
5114 
5115 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
5116 		ext4_msg(sb, KERN_ERR,
5117 			 "Number of reserved GDT blocks insanely large: %d",
5118 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
5119 		goto failed_mount;
5120 	}
5121 
5122 	if (sbi->s_daxdev) {
5123 		if (sb->s_blocksize == PAGE_SIZE)
5124 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
5125 		else
5126 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
5127 	}
5128 
5129 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
5130 		if (ext4_has_feature_inline_data(sb)) {
5131 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
5132 					" that may contain inline data");
5133 			goto failed_mount;
5134 		}
5135 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
5136 			ext4_msg(sb, KERN_ERR,
5137 				"DAX unsupported by block device.");
5138 			goto failed_mount;
5139 		}
5140 	}
5141 
5142 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
5143 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
5144 			 es->s_encryption_level);
5145 		goto failed_mount;
5146 	}
5147 
5148 	has_huge_files = ext4_has_feature_huge_file(sb);
5149 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5150 						      has_huge_files);
5151 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5152 
5153 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5154 	if (ext4_has_feature_64bit(sb)) {
5155 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5156 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5157 		    !is_power_of_2(sbi->s_desc_size)) {
5158 			ext4_msg(sb, KERN_ERR,
5159 			       "unsupported descriptor size %lu",
5160 			       sbi->s_desc_size);
5161 			goto failed_mount;
5162 		}
5163 	} else
5164 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5165 
5166 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5167 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5168 
5169 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5170 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5171 		if (!silent)
5172 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5173 		goto failed_mount;
5174 	}
5175 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5176 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5177 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5178 			 sbi->s_inodes_per_group);
5179 		goto failed_mount;
5180 	}
5181 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5182 					sbi->s_inodes_per_block;
5183 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5184 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5185 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5186 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5187 
5188 	for (i = 0; i < 4; i++)
5189 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5190 	sbi->s_def_hash_version = es->s_def_hash_version;
5191 	if (ext4_has_feature_dir_index(sb)) {
5192 		i = le32_to_cpu(es->s_flags);
5193 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5194 			sbi->s_hash_unsigned = 3;
5195 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5196 #ifdef __CHAR_UNSIGNED__
5197 			if (!sb_rdonly(sb))
5198 				es->s_flags |=
5199 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5200 			sbi->s_hash_unsigned = 3;
5201 #else
5202 			if (!sb_rdonly(sb))
5203 				es->s_flags |=
5204 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5205 #endif
5206 		}
5207 	}
5208 
5209 	if (ext4_handle_clustersize(sb))
5210 		goto failed_mount;
5211 
5212 	/*
5213 	 * Test whether we have more sectors than will fit in sector_t,
5214 	 * and whether the max offset is addressable by the page cache.
5215 	 */
5216 	err = generic_check_addressable(sb->s_blocksize_bits,
5217 					ext4_blocks_count(es));
5218 	if (err) {
5219 		ext4_msg(sb, KERN_ERR, "filesystem"
5220 			 " too large to mount safely on this system");
5221 		goto failed_mount;
5222 	}
5223 
5224 	if (ext4_geometry_check(sb, es))
5225 		goto failed_mount;
5226 
5227 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5228 	if (err)
5229 		goto failed_mount;
5230 
5231 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5232 	spin_lock_init(&sbi->s_error_lock);
5233 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5234 
5235 	/* Register extent status tree shrinker */
5236 	if (ext4_es_register_shrinker(sbi))
5237 		goto failed_mount3;
5238 
5239 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5240 	sbi->s_extent_max_zeroout_kb = 32;
5241 
5242 	/*
5243 	 * set up enough so that it can read an inode
5244 	 */
5245 	sb->s_op = &ext4_sops;
5246 	sb->s_export_op = &ext4_export_ops;
5247 	sb->s_xattr = ext4_xattr_handlers;
5248 #ifdef CONFIG_FS_ENCRYPTION
5249 	sb->s_cop = &ext4_cryptops;
5250 #endif
5251 #ifdef CONFIG_FS_VERITY
5252 	sb->s_vop = &ext4_verityops;
5253 #endif
5254 #ifdef CONFIG_QUOTA
5255 	sb->dq_op = &ext4_quota_operations;
5256 	if (ext4_has_feature_quota(sb))
5257 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5258 	else
5259 		sb->s_qcop = &ext4_qctl_operations;
5260 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5261 #endif
5262 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5263 
5264 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5265 	mutex_init(&sbi->s_orphan_lock);
5266 
5267 	ext4_fast_commit_init(sb);
5268 
5269 	sb->s_root = NULL;
5270 
5271 	needs_recovery = (es->s_last_orphan != 0 ||
5272 			  ext4_has_feature_orphan_present(sb) ||
5273 			  ext4_has_feature_journal_needs_recovery(sb));
5274 
5275 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5276 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5277 			goto failed_mount3a;
5278 
5279 	/*
5280 	 * The first inode we look at is the journal inode.  Don't try
5281 	 * root first: it may be modified in the journal!
5282 	 */
5283 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5284 		err = ext4_load_and_init_journal(sb, es, ctx);
5285 		if (err)
5286 			goto failed_mount3a;
5287 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5288 		   ext4_has_feature_journal_needs_recovery(sb)) {
5289 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5290 		       "suppressed and not mounted read-only");
5291 		goto failed_mount3a;
5292 	} else {
5293 		/* Nojournal mode, all journal mount options are illegal */
5294 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5295 			ext4_msg(sb, KERN_ERR, "can't mount with "
5296 				 "journal_checksum, fs mounted w/o journal");
5297 			goto failed_mount3a;
5298 		}
5299 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5300 			ext4_msg(sb, KERN_ERR, "can't mount with "
5301 				 "journal_async_commit, fs mounted w/o journal");
5302 			goto failed_mount3a;
5303 		}
5304 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5305 			ext4_msg(sb, KERN_ERR, "can't mount with "
5306 				 "commit=%lu, fs mounted w/o journal",
5307 				 sbi->s_commit_interval / HZ);
5308 			goto failed_mount3a;
5309 		}
5310 		if (EXT4_MOUNT_DATA_FLAGS &
5311 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5312 			ext4_msg(sb, KERN_ERR, "can't mount with "
5313 				 "data=, fs mounted w/o journal");
5314 			goto failed_mount3a;
5315 		}
5316 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5317 		clear_opt(sb, JOURNAL_CHECKSUM);
5318 		clear_opt(sb, DATA_FLAGS);
5319 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5320 		sbi->s_journal = NULL;
5321 		needs_recovery = 0;
5322 	}
5323 
5324 	if (!test_opt(sb, NO_MBCACHE)) {
5325 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5326 		if (!sbi->s_ea_block_cache) {
5327 			ext4_msg(sb, KERN_ERR,
5328 				 "Failed to create ea_block_cache");
5329 			goto failed_mount_wq;
5330 		}
5331 
5332 		if (ext4_has_feature_ea_inode(sb)) {
5333 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5334 			if (!sbi->s_ea_inode_cache) {
5335 				ext4_msg(sb, KERN_ERR,
5336 					 "Failed to create ea_inode_cache");
5337 				goto failed_mount_wq;
5338 			}
5339 		}
5340 	}
5341 
5342 	if (ext4_has_feature_verity(sb) && sb->s_blocksize != PAGE_SIZE) {
5343 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5344 		goto failed_mount_wq;
5345 	}
5346 
5347 	/*
5348 	 * Get the # of file system overhead blocks from the
5349 	 * superblock if present.
5350 	 */
5351 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5352 	/* ignore the precalculated value if it is ridiculous */
5353 	if (sbi->s_overhead > ext4_blocks_count(es))
5354 		sbi->s_overhead = 0;
5355 	/*
5356 	 * If the bigalloc feature is not enabled recalculating the
5357 	 * overhead doesn't take long, so we might as well just redo
5358 	 * it to make sure we are using the correct value.
5359 	 */
5360 	if (!ext4_has_feature_bigalloc(sb))
5361 		sbi->s_overhead = 0;
5362 	if (sbi->s_overhead == 0) {
5363 		err = ext4_calculate_overhead(sb);
5364 		if (err)
5365 			goto failed_mount_wq;
5366 	}
5367 
5368 	/*
5369 	 * The maximum number of concurrent works can be high and
5370 	 * concurrency isn't really necessary.  Limit it to 1.
5371 	 */
5372 	EXT4_SB(sb)->rsv_conversion_wq =
5373 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5374 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5375 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5376 		ret = -ENOMEM;
5377 		goto failed_mount4;
5378 	}
5379 
5380 	/*
5381 	 * The jbd2_journal_load will have done any necessary log recovery,
5382 	 * so we can safely mount the rest of the filesystem now.
5383 	 */
5384 
5385 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5386 	if (IS_ERR(root)) {
5387 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5388 		ret = PTR_ERR(root);
5389 		root = NULL;
5390 		goto failed_mount4;
5391 	}
5392 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5393 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5394 		iput(root);
5395 		goto failed_mount4;
5396 	}
5397 
5398 	sb->s_root = d_make_root(root);
5399 	if (!sb->s_root) {
5400 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5401 		ret = -ENOMEM;
5402 		goto failed_mount4;
5403 	}
5404 
5405 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5406 	if (ret == -EROFS) {
5407 		sb->s_flags |= SB_RDONLY;
5408 		ret = 0;
5409 	} else if (ret)
5410 		goto failed_mount4a;
5411 
5412 	ext4_set_resv_clusters(sb);
5413 
5414 	if (test_opt(sb, BLOCK_VALIDITY)) {
5415 		err = ext4_setup_system_zone(sb);
5416 		if (err) {
5417 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5418 				 "zone (%d)", err);
5419 			goto failed_mount4a;
5420 		}
5421 	}
5422 	ext4_fc_replay_cleanup(sb);
5423 
5424 	ext4_ext_init(sb);
5425 
5426 	/*
5427 	 * Enable optimize_scan if number of groups is > threshold. This can be
5428 	 * turned off by passing "mb_optimize_scan=0". This can also be
5429 	 * turned on forcefully by passing "mb_optimize_scan=1".
5430 	 */
5431 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5432 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5433 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5434 		else
5435 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5436 	}
5437 
5438 	err = ext4_mb_init(sb);
5439 	if (err) {
5440 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5441 			 err);
5442 		goto failed_mount5;
5443 	}
5444 
5445 	/*
5446 	 * We can only set up the journal commit callback once
5447 	 * mballoc is initialized
5448 	 */
5449 	if (sbi->s_journal)
5450 		sbi->s_journal->j_commit_callback =
5451 			ext4_journal_commit_callback;
5452 
5453 	block = ext4_count_free_clusters(sb);
5454 	ext4_free_blocks_count_set(sbi->s_es,
5455 				   EXT4_C2B(sbi, block));
5456 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5457 				  GFP_KERNEL);
5458 	if (!err) {
5459 		unsigned long freei = ext4_count_free_inodes(sb);
5460 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5461 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5462 					  GFP_KERNEL);
5463 	}
5464 	if (!err)
5465 		err = percpu_counter_init(&sbi->s_dirs_counter,
5466 					  ext4_count_dirs(sb), GFP_KERNEL);
5467 	if (!err)
5468 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5469 					  GFP_KERNEL);
5470 	if (!err)
5471 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5472 					  GFP_KERNEL);
5473 	if (!err)
5474 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5475 
5476 	if (err) {
5477 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5478 		goto failed_mount6;
5479 	}
5480 
5481 	if (ext4_has_feature_flex_bg(sb))
5482 		if (!ext4_fill_flex_info(sb)) {
5483 			ext4_msg(sb, KERN_ERR,
5484 			       "unable to initialize "
5485 			       "flex_bg meta info!");
5486 			ret = -ENOMEM;
5487 			goto failed_mount6;
5488 		}
5489 
5490 	err = ext4_register_li_request(sb, first_not_zeroed);
5491 	if (err)
5492 		goto failed_mount6;
5493 
5494 	err = ext4_register_sysfs(sb);
5495 	if (err)
5496 		goto failed_mount7;
5497 
5498 	err = ext4_init_orphan_info(sb);
5499 	if (err)
5500 		goto failed_mount8;
5501 #ifdef CONFIG_QUOTA
5502 	/* Enable quota usage during mount. */
5503 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5504 		err = ext4_enable_quotas(sb);
5505 		if (err)
5506 			goto failed_mount9;
5507 	}
5508 #endif  /* CONFIG_QUOTA */
5509 
5510 	/*
5511 	 * Save the original bdev mapping's wb_err value which could be
5512 	 * used to detect the metadata async write error.
5513 	 */
5514 	spin_lock_init(&sbi->s_bdev_wb_lock);
5515 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5516 				 &sbi->s_bdev_wb_err);
5517 	sb->s_bdev->bd_super = sb;
5518 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5519 	ext4_orphan_cleanup(sb, es);
5520 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5521 	/*
5522 	 * Update the checksum after updating free space/inode counters and
5523 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5524 	 * checksum in the buffer cache until it is written out and
5525 	 * e2fsprogs programs trying to open a file system immediately
5526 	 * after it is mounted can fail.
5527 	 */
5528 	ext4_superblock_csum_set(sb);
5529 	if (needs_recovery) {
5530 		ext4_msg(sb, KERN_INFO, "recovery complete");
5531 		err = ext4_mark_recovery_complete(sb, es);
5532 		if (err)
5533 			goto failed_mount9;
5534 	}
5535 
5536 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5537 		ext4_msg(sb, KERN_WARNING,
5538 			 "mounting with \"discard\" option, but the device does not support discard");
5539 
5540 	if (es->s_error_count)
5541 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5542 
5543 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5544 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5545 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5546 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5547 	atomic_set(&sbi->s_warning_count, 0);
5548 	atomic_set(&sbi->s_msg_count, 0);
5549 
5550 	return 0;
5551 
5552 failed_mount9:
5553 	ext4_release_orphan_info(sb);
5554 failed_mount8:
5555 	ext4_unregister_sysfs(sb);
5556 	kobject_put(&sbi->s_kobj);
5557 failed_mount7:
5558 	ext4_unregister_li_request(sb);
5559 failed_mount6:
5560 	ext4_mb_release(sb);
5561 	rcu_read_lock();
5562 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5563 	if (flex_groups) {
5564 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5565 			kvfree(flex_groups[i]);
5566 		kvfree(flex_groups);
5567 	}
5568 	rcu_read_unlock();
5569 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5570 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5571 	percpu_counter_destroy(&sbi->s_dirs_counter);
5572 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5573 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5574 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5575 failed_mount5:
5576 	ext4_ext_release(sb);
5577 	ext4_release_system_zone(sb);
5578 failed_mount4a:
5579 	dput(sb->s_root);
5580 	sb->s_root = NULL;
5581 failed_mount4:
5582 	ext4_msg(sb, KERN_ERR, "mount failed");
5583 	if (EXT4_SB(sb)->rsv_conversion_wq)
5584 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5585 failed_mount_wq:
5586 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5587 	sbi->s_ea_inode_cache = NULL;
5588 
5589 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5590 	sbi->s_ea_block_cache = NULL;
5591 
5592 	if (sbi->s_journal) {
5593 		/* flush s_error_work before journal destroy. */
5594 		flush_work(&sbi->s_error_work);
5595 		jbd2_journal_destroy(sbi->s_journal);
5596 		sbi->s_journal = NULL;
5597 	}
5598 failed_mount3a:
5599 	ext4_es_unregister_shrinker(sbi);
5600 failed_mount3:
5601 	/* flush s_error_work before sbi destroy */
5602 	flush_work(&sbi->s_error_work);
5603 	del_timer_sync(&sbi->s_err_report);
5604 	ext4_stop_mmpd(sbi);
5605 	ext4_group_desc_free(sbi);
5606 failed_mount:
5607 	if (sbi->s_chksum_driver)
5608 		crypto_free_shash(sbi->s_chksum_driver);
5609 
5610 #if IS_ENABLED(CONFIG_UNICODE)
5611 	utf8_unload(sb->s_encoding);
5612 #endif
5613 
5614 #ifdef CONFIG_QUOTA
5615 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5616 		kfree(get_qf_name(sb, sbi, i));
5617 #endif
5618 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5619 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5620 	brelse(sbi->s_sbh);
5621 	ext4_blkdev_remove(sbi);
5622 out_fail:
5623 	sb->s_fs_info = NULL;
5624 	return err ? err : ret;
5625 }
5626 
5627 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5628 {
5629 	struct ext4_fs_context *ctx = fc->fs_private;
5630 	struct ext4_sb_info *sbi;
5631 	const char *descr;
5632 	int ret;
5633 
5634 	sbi = ext4_alloc_sbi(sb);
5635 	if (!sbi)
5636 		return -ENOMEM;
5637 
5638 	fc->s_fs_info = sbi;
5639 
5640 	/* Cleanup superblock name */
5641 	strreplace(sb->s_id, '/', '!');
5642 
5643 	sbi->s_sb_block = 1;	/* Default super block location */
5644 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5645 		sbi->s_sb_block = ctx->s_sb_block;
5646 
5647 	ret = __ext4_fill_super(fc, sb);
5648 	if (ret < 0)
5649 		goto free_sbi;
5650 
5651 	if (sbi->s_journal) {
5652 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5653 			descr = " journalled data mode";
5654 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5655 			descr = " ordered data mode";
5656 		else
5657 			descr = " writeback data mode";
5658 	} else
5659 		descr = "out journal";
5660 
5661 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5662 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5663 			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
5664 
5665 	/* Update the s_overhead_clusters if necessary */
5666 	ext4_update_overhead(sb, false);
5667 	return 0;
5668 
5669 free_sbi:
5670 	ext4_free_sbi(sbi);
5671 	fc->s_fs_info = NULL;
5672 	return ret;
5673 }
5674 
5675 static int ext4_get_tree(struct fs_context *fc)
5676 {
5677 	return get_tree_bdev(fc, ext4_fill_super);
5678 }
5679 
5680 /*
5681  * Setup any per-fs journal parameters now.  We'll do this both on
5682  * initial mount, once the journal has been initialised but before we've
5683  * done any recovery; and again on any subsequent remount.
5684  */
5685 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5686 {
5687 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5688 
5689 	journal->j_commit_interval = sbi->s_commit_interval;
5690 	journal->j_min_batch_time = sbi->s_min_batch_time;
5691 	journal->j_max_batch_time = sbi->s_max_batch_time;
5692 	ext4_fc_init(sb, journal);
5693 
5694 	write_lock(&journal->j_state_lock);
5695 	if (test_opt(sb, BARRIER))
5696 		journal->j_flags |= JBD2_BARRIER;
5697 	else
5698 		journal->j_flags &= ~JBD2_BARRIER;
5699 	if (test_opt(sb, DATA_ERR_ABORT))
5700 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5701 	else
5702 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5703 	write_unlock(&journal->j_state_lock);
5704 }
5705 
5706 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5707 					     unsigned int journal_inum)
5708 {
5709 	struct inode *journal_inode;
5710 
5711 	/*
5712 	 * Test for the existence of a valid inode on disk.  Bad things
5713 	 * happen if we iget() an unused inode, as the subsequent iput()
5714 	 * will try to delete it.
5715 	 */
5716 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5717 	if (IS_ERR(journal_inode)) {
5718 		ext4_msg(sb, KERN_ERR, "no journal found");
5719 		return NULL;
5720 	}
5721 	if (!journal_inode->i_nlink) {
5722 		make_bad_inode(journal_inode);
5723 		iput(journal_inode);
5724 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5725 		return NULL;
5726 	}
5727 
5728 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5729 		  journal_inode, journal_inode->i_size);
5730 	if (!S_ISREG(journal_inode->i_mode)) {
5731 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5732 		iput(journal_inode);
5733 		return NULL;
5734 	}
5735 	return journal_inode;
5736 }
5737 
5738 static journal_t *ext4_get_journal(struct super_block *sb,
5739 				   unsigned int journal_inum)
5740 {
5741 	struct inode *journal_inode;
5742 	journal_t *journal;
5743 
5744 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5745 		return NULL;
5746 
5747 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5748 	if (!journal_inode)
5749 		return NULL;
5750 
5751 	journal = jbd2_journal_init_inode(journal_inode);
5752 	if (!journal) {
5753 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5754 		iput(journal_inode);
5755 		return NULL;
5756 	}
5757 	journal->j_private = sb;
5758 	ext4_init_journal_params(sb, journal);
5759 	return journal;
5760 }
5761 
5762 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5763 				       dev_t j_dev)
5764 {
5765 	struct buffer_head *bh;
5766 	journal_t *journal;
5767 	ext4_fsblk_t start;
5768 	ext4_fsblk_t len;
5769 	int hblock, blocksize;
5770 	ext4_fsblk_t sb_block;
5771 	unsigned long offset;
5772 	struct ext4_super_block *es;
5773 	struct block_device *bdev;
5774 
5775 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5776 		return NULL;
5777 
5778 	bdev = ext4_blkdev_get(j_dev, sb);
5779 	if (bdev == NULL)
5780 		return NULL;
5781 
5782 	blocksize = sb->s_blocksize;
5783 	hblock = bdev_logical_block_size(bdev);
5784 	if (blocksize < hblock) {
5785 		ext4_msg(sb, KERN_ERR,
5786 			"blocksize too small for journal device");
5787 		goto out_bdev;
5788 	}
5789 
5790 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5791 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5792 	set_blocksize(bdev, blocksize);
5793 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5794 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5795 		       "external journal");
5796 		goto out_bdev;
5797 	}
5798 
5799 	es = (struct ext4_super_block *) (bh->b_data + offset);
5800 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5801 	    !(le32_to_cpu(es->s_feature_incompat) &
5802 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5803 		ext4_msg(sb, KERN_ERR, "external journal has "
5804 					"bad superblock");
5805 		brelse(bh);
5806 		goto out_bdev;
5807 	}
5808 
5809 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5810 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5811 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5812 		ext4_msg(sb, KERN_ERR, "external journal has "
5813 				       "corrupt superblock");
5814 		brelse(bh);
5815 		goto out_bdev;
5816 	}
5817 
5818 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5819 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5820 		brelse(bh);
5821 		goto out_bdev;
5822 	}
5823 
5824 	len = ext4_blocks_count(es);
5825 	start = sb_block + 1;
5826 	brelse(bh);	/* we're done with the superblock */
5827 
5828 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5829 					start, len, blocksize);
5830 	if (!journal) {
5831 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5832 		goto out_bdev;
5833 	}
5834 	journal->j_private = sb;
5835 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5836 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5837 		goto out_journal;
5838 	}
5839 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5840 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5841 					"user (unsupported) - %d",
5842 			be32_to_cpu(journal->j_superblock->s_nr_users));
5843 		goto out_journal;
5844 	}
5845 	EXT4_SB(sb)->s_journal_bdev = bdev;
5846 	ext4_init_journal_params(sb, journal);
5847 	return journal;
5848 
5849 out_journal:
5850 	jbd2_journal_destroy(journal);
5851 out_bdev:
5852 	ext4_blkdev_put(bdev);
5853 	return NULL;
5854 }
5855 
5856 static int ext4_load_journal(struct super_block *sb,
5857 			     struct ext4_super_block *es,
5858 			     unsigned long journal_devnum)
5859 {
5860 	journal_t *journal;
5861 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5862 	dev_t journal_dev;
5863 	int err = 0;
5864 	int really_read_only;
5865 	int journal_dev_ro;
5866 
5867 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5868 		return -EFSCORRUPTED;
5869 
5870 	if (journal_devnum &&
5871 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5872 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5873 			"numbers have changed");
5874 		journal_dev = new_decode_dev(journal_devnum);
5875 	} else
5876 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5877 
5878 	if (journal_inum && journal_dev) {
5879 		ext4_msg(sb, KERN_ERR,
5880 			 "filesystem has both journal inode and journal device!");
5881 		return -EINVAL;
5882 	}
5883 
5884 	if (journal_inum) {
5885 		journal = ext4_get_journal(sb, journal_inum);
5886 		if (!journal)
5887 			return -EINVAL;
5888 	} else {
5889 		journal = ext4_get_dev_journal(sb, journal_dev);
5890 		if (!journal)
5891 			return -EINVAL;
5892 	}
5893 
5894 	journal_dev_ro = bdev_read_only(journal->j_dev);
5895 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5896 
5897 	if (journal_dev_ro && !sb_rdonly(sb)) {
5898 		ext4_msg(sb, KERN_ERR,
5899 			 "journal device read-only, try mounting with '-o ro'");
5900 		err = -EROFS;
5901 		goto err_out;
5902 	}
5903 
5904 	/*
5905 	 * Are we loading a blank journal or performing recovery after a
5906 	 * crash?  For recovery, we need to check in advance whether we
5907 	 * can get read-write access to the device.
5908 	 */
5909 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5910 		if (sb_rdonly(sb)) {
5911 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5912 					"required on readonly filesystem");
5913 			if (really_read_only) {
5914 				ext4_msg(sb, KERN_ERR, "write access "
5915 					"unavailable, cannot proceed "
5916 					"(try mounting with noload)");
5917 				err = -EROFS;
5918 				goto err_out;
5919 			}
5920 			ext4_msg(sb, KERN_INFO, "write access will "
5921 			       "be enabled during recovery");
5922 		}
5923 	}
5924 
5925 	if (!(journal->j_flags & JBD2_BARRIER))
5926 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5927 
5928 	if (!ext4_has_feature_journal_needs_recovery(sb))
5929 		err = jbd2_journal_wipe(journal, !really_read_only);
5930 	if (!err) {
5931 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5932 		if (save)
5933 			memcpy(save, ((char *) es) +
5934 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5935 		err = jbd2_journal_load(journal);
5936 		if (save)
5937 			memcpy(((char *) es) + EXT4_S_ERR_START,
5938 			       save, EXT4_S_ERR_LEN);
5939 		kfree(save);
5940 	}
5941 
5942 	if (err) {
5943 		ext4_msg(sb, KERN_ERR, "error loading journal");
5944 		goto err_out;
5945 	}
5946 
5947 	EXT4_SB(sb)->s_journal = journal;
5948 	err = ext4_clear_journal_err(sb, es);
5949 	if (err) {
5950 		EXT4_SB(sb)->s_journal = NULL;
5951 		jbd2_journal_destroy(journal);
5952 		return err;
5953 	}
5954 
5955 	if (!really_read_only && journal_devnum &&
5956 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5957 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5958 
5959 		/* Make sure we flush the recovery flag to disk. */
5960 		ext4_commit_super(sb);
5961 	}
5962 
5963 	return 0;
5964 
5965 err_out:
5966 	jbd2_journal_destroy(journal);
5967 	return err;
5968 }
5969 
5970 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5971 static void ext4_update_super(struct super_block *sb)
5972 {
5973 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5974 	struct ext4_super_block *es = sbi->s_es;
5975 	struct buffer_head *sbh = sbi->s_sbh;
5976 
5977 	lock_buffer(sbh);
5978 	/*
5979 	 * If the file system is mounted read-only, don't update the
5980 	 * superblock write time.  This avoids updating the superblock
5981 	 * write time when we are mounting the root file system
5982 	 * read/only but we need to replay the journal; at that point,
5983 	 * for people who are east of GMT and who make their clock
5984 	 * tick in localtime for Windows bug-for-bug compatibility,
5985 	 * the clock is set in the future, and this will cause e2fsck
5986 	 * to complain and force a full file system check.
5987 	 */
5988 	if (!(sb->s_flags & SB_RDONLY))
5989 		ext4_update_tstamp(es, s_wtime);
5990 	es->s_kbytes_written =
5991 		cpu_to_le64(sbi->s_kbytes_written +
5992 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5993 		      sbi->s_sectors_written_start) >> 1));
5994 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5995 		ext4_free_blocks_count_set(es,
5996 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5997 				&sbi->s_freeclusters_counter)));
5998 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5999 		es->s_free_inodes_count =
6000 			cpu_to_le32(percpu_counter_sum_positive(
6001 				&sbi->s_freeinodes_counter));
6002 	/* Copy error information to the on-disk superblock */
6003 	spin_lock(&sbi->s_error_lock);
6004 	if (sbi->s_add_error_count > 0) {
6005 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6006 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6007 			__ext4_update_tstamp(&es->s_first_error_time,
6008 					     &es->s_first_error_time_hi,
6009 					     sbi->s_first_error_time);
6010 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6011 				sizeof(es->s_first_error_func));
6012 			es->s_first_error_line =
6013 				cpu_to_le32(sbi->s_first_error_line);
6014 			es->s_first_error_ino =
6015 				cpu_to_le32(sbi->s_first_error_ino);
6016 			es->s_first_error_block =
6017 				cpu_to_le64(sbi->s_first_error_block);
6018 			es->s_first_error_errcode =
6019 				ext4_errno_to_code(sbi->s_first_error_code);
6020 		}
6021 		__ext4_update_tstamp(&es->s_last_error_time,
6022 				     &es->s_last_error_time_hi,
6023 				     sbi->s_last_error_time);
6024 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6025 			sizeof(es->s_last_error_func));
6026 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6027 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6028 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6029 		es->s_last_error_errcode =
6030 				ext4_errno_to_code(sbi->s_last_error_code);
6031 		/*
6032 		 * Start the daily error reporting function if it hasn't been
6033 		 * started already
6034 		 */
6035 		if (!es->s_error_count)
6036 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6037 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6038 		sbi->s_add_error_count = 0;
6039 	}
6040 	spin_unlock(&sbi->s_error_lock);
6041 
6042 	ext4_superblock_csum_set(sb);
6043 	unlock_buffer(sbh);
6044 }
6045 
6046 static int ext4_commit_super(struct super_block *sb)
6047 {
6048 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6049 
6050 	if (!sbh)
6051 		return -EINVAL;
6052 	if (block_device_ejected(sb))
6053 		return -ENODEV;
6054 
6055 	ext4_update_super(sb);
6056 
6057 	lock_buffer(sbh);
6058 	/* Buffer got discarded which means block device got invalidated */
6059 	if (!buffer_mapped(sbh)) {
6060 		unlock_buffer(sbh);
6061 		return -EIO;
6062 	}
6063 
6064 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6065 		/*
6066 		 * Oh, dear.  A previous attempt to write the
6067 		 * superblock failed.  This could happen because the
6068 		 * USB device was yanked out.  Or it could happen to
6069 		 * be a transient write error and maybe the block will
6070 		 * be remapped.  Nothing we can do but to retry the
6071 		 * write and hope for the best.
6072 		 */
6073 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6074 		       "superblock detected");
6075 		clear_buffer_write_io_error(sbh);
6076 		set_buffer_uptodate(sbh);
6077 	}
6078 	get_bh(sbh);
6079 	/* Clear potential dirty bit if it was journalled update */
6080 	clear_buffer_dirty(sbh);
6081 	sbh->b_end_io = end_buffer_write_sync;
6082 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6083 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6084 	wait_on_buffer(sbh);
6085 	if (buffer_write_io_error(sbh)) {
6086 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6087 		       "superblock");
6088 		clear_buffer_write_io_error(sbh);
6089 		set_buffer_uptodate(sbh);
6090 		return -EIO;
6091 	}
6092 	return 0;
6093 }
6094 
6095 /*
6096  * Have we just finished recovery?  If so, and if we are mounting (or
6097  * remounting) the filesystem readonly, then we will end up with a
6098  * consistent fs on disk.  Record that fact.
6099  */
6100 static int ext4_mark_recovery_complete(struct super_block *sb,
6101 				       struct ext4_super_block *es)
6102 {
6103 	int err;
6104 	journal_t *journal = EXT4_SB(sb)->s_journal;
6105 
6106 	if (!ext4_has_feature_journal(sb)) {
6107 		if (journal != NULL) {
6108 			ext4_error(sb, "Journal got removed while the fs was "
6109 				   "mounted!");
6110 			return -EFSCORRUPTED;
6111 		}
6112 		return 0;
6113 	}
6114 	jbd2_journal_lock_updates(journal);
6115 	err = jbd2_journal_flush(journal, 0);
6116 	if (err < 0)
6117 		goto out;
6118 
6119 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6120 	    ext4_has_feature_orphan_present(sb))) {
6121 		if (!ext4_orphan_file_empty(sb)) {
6122 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6123 			err = -EFSCORRUPTED;
6124 			goto out;
6125 		}
6126 		ext4_clear_feature_journal_needs_recovery(sb);
6127 		ext4_clear_feature_orphan_present(sb);
6128 		ext4_commit_super(sb);
6129 	}
6130 out:
6131 	jbd2_journal_unlock_updates(journal);
6132 	return err;
6133 }
6134 
6135 /*
6136  * If we are mounting (or read-write remounting) a filesystem whose journal
6137  * has recorded an error from a previous lifetime, move that error to the
6138  * main filesystem now.
6139  */
6140 static int ext4_clear_journal_err(struct super_block *sb,
6141 				   struct ext4_super_block *es)
6142 {
6143 	journal_t *journal;
6144 	int j_errno;
6145 	const char *errstr;
6146 
6147 	if (!ext4_has_feature_journal(sb)) {
6148 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6149 		return -EFSCORRUPTED;
6150 	}
6151 
6152 	journal = EXT4_SB(sb)->s_journal;
6153 
6154 	/*
6155 	 * Now check for any error status which may have been recorded in the
6156 	 * journal by a prior ext4_error() or ext4_abort()
6157 	 */
6158 
6159 	j_errno = jbd2_journal_errno(journal);
6160 	if (j_errno) {
6161 		char nbuf[16];
6162 
6163 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6164 		ext4_warning(sb, "Filesystem error recorded "
6165 			     "from previous mount: %s", errstr);
6166 		ext4_warning(sb, "Marking fs in need of filesystem check.");
6167 
6168 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6169 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6170 		ext4_commit_super(sb);
6171 
6172 		jbd2_journal_clear_err(journal);
6173 		jbd2_journal_update_sb_errno(journal);
6174 	}
6175 	return 0;
6176 }
6177 
6178 /*
6179  * Force the running and committing transactions to commit,
6180  * and wait on the commit.
6181  */
6182 int ext4_force_commit(struct super_block *sb)
6183 {
6184 	journal_t *journal;
6185 
6186 	if (sb_rdonly(sb))
6187 		return 0;
6188 
6189 	journal = EXT4_SB(sb)->s_journal;
6190 	return ext4_journal_force_commit(journal);
6191 }
6192 
6193 static int ext4_sync_fs(struct super_block *sb, int wait)
6194 {
6195 	int ret = 0;
6196 	tid_t target;
6197 	bool needs_barrier = false;
6198 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6199 
6200 	if (unlikely(ext4_forced_shutdown(sbi)))
6201 		return 0;
6202 
6203 	trace_ext4_sync_fs(sb, wait);
6204 	flush_workqueue(sbi->rsv_conversion_wq);
6205 	/*
6206 	 * Writeback quota in non-journalled quota case - journalled quota has
6207 	 * no dirty dquots
6208 	 */
6209 	dquot_writeback_dquots(sb, -1);
6210 	/*
6211 	 * Data writeback is possible w/o journal transaction, so barrier must
6212 	 * being sent at the end of the function. But we can skip it if
6213 	 * transaction_commit will do it for us.
6214 	 */
6215 	if (sbi->s_journal) {
6216 		target = jbd2_get_latest_transaction(sbi->s_journal);
6217 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6218 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6219 			needs_barrier = true;
6220 
6221 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6222 			if (wait)
6223 				ret = jbd2_log_wait_commit(sbi->s_journal,
6224 							   target);
6225 		}
6226 	} else if (wait && test_opt(sb, BARRIER))
6227 		needs_barrier = true;
6228 	if (needs_barrier) {
6229 		int err;
6230 		err = blkdev_issue_flush(sb->s_bdev);
6231 		if (!ret)
6232 			ret = err;
6233 	}
6234 
6235 	return ret;
6236 }
6237 
6238 /*
6239  * LVM calls this function before a (read-only) snapshot is created.  This
6240  * gives us a chance to flush the journal completely and mark the fs clean.
6241  *
6242  * Note that only this function cannot bring a filesystem to be in a clean
6243  * state independently. It relies on upper layer to stop all data & metadata
6244  * modifications.
6245  */
6246 static int ext4_freeze(struct super_block *sb)
6247 {
6248 	int error = 0;
6249 	journal_t *journal;
6250 
6251 	if (sb_rdonly(sb))
6252 		return 0;
6253 
6254 	journal = EXT4_SB(sb)->s_journal;
6255 
6256 	if (journal) {
6257 		/* Now we set up the journal barrier. */
6258 		jbd2_journal_lock_updates(journal);
6259 
6260 		/*
6261 		 * Don't clear the needs_recovery flag if we failed to
6262 		 * flush the journal.
6263 		 */
6264 		error = jbd2_journal_flush(journal, 0);
6265 		if (error < 0)
6266 			goto out;
6267 
6268 		/* Journal blocked and flushed, clear needs_recovery flag. */
6269 		ext4_clear_feature_journal_needs_recovery(sb);
6270 		if (ext4_orphan_file_empty(sb))
6271 			ext4_clear_feature_orphan_present(sb);
6272 	}
6273 
6274 	error = ext4_commit_super(sb);
6275 out:
6276 	if (journal)
6277 		/* we rely on upper layer to stop further updates */
6278 		jbd2_journal_unlock_updates(journal);
6279 	return error;
6280 }
6281 
6282 /*
6283  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6284  * flag here, even though the filesystem is not technically dirty yet.
6285  */
6286 static int ext4_unfreeze(struct super_block *sb)
6287 {
6288 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6289 		return 0;
6290 
6291 	if (EXT4_SB(sb)->s_journal) {
6292 		/* Reset the needs_recovery flag before the fs is unlocked. */
6293 		ext4_set_feature_journal_needs_recovery(sb);
6294 		if (ext4_has_feature_orphan_file(sb))
6295 			ext4_set_feature_orphan_present(sb);
6296 	}
6297 
6298 	ext4_commit_super(sb);
6299 	return 0;
6300 }
6301 
6302 /*
6303  * Structure to save mount options for ext4_remount's benefit
6304  */
6305 struct ext4_mount_options {
6306 	unsigned long s_mount_opt;
6307 	unsigned long s_mount_opt2;
6308 	kuid_t s_resuid;
6309 	kgid_t s_resgid;
6310 	unsigned long s_commit_interval;
6311 	u32 s_min_batch_time, s_max_batch_time;
6312 #ifdef CONFIG_QUOTA
6313 	int s_jquota_fmt;
6314 	char *s_qf_names[EXT4_MAXQUOTAS];
6315 #endif
6316 };
6317 
6318 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6319 {
6320 	struct ext4_fs_context *ctx = fc->fs_private;
6321 	struct ext4_super_block *es;
6322 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6323 	unsigned long old_sb_flags;
6324 	struct ext4_mount_options old_opts;
6325 	ext4_group_t g;
6326 	int err = 0;
6327 #ifdef CONFIG_QUOTA
6328 	int enable_quota = 0;
6329 	int i, j;
6330 	char *to_free[EXT4_MAXQUOTAS];
6331 #endif
6332 
6333 
6334 	/* Store the original options */
6335 	old_sb_flags = sb->s_flags;
6336 	old_opts.s_mount_opt = sbi->s_mount_opt;
6337 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6338 	old_opts.s_resuid = sbi->s_resuid;
6339 	old_opts.s_resgid = sbi->s_resgid;
6340 	old_opts.s_commit_interval = sbi->s_commit_interval;
6341 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6342 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6343 #ifdef CONFIG_QUOTA
6344 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6345 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6346 		if (sbi->s_qf_names[i]) {
6347 			char *qf_name = get_qf_name(sb, sbi, i);
6348 
6349 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6350 			if (!old_opts.s_qf_names[i]) {
6351 				for (j = 0; j < i; j++)
6352 					kfree(old_opts.s_qf_names[j]);
6353 				return -ENOMEM;
6354 			}
6355 		} else
6356 			old_opts.s_qf_names[i] = NULL;
6357 #endif
6358 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6359 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6360 			ctx->journal_ioprio =
6361 				sbi->s_journal->j_task->io_context->ioprio;
6362 		else
6363 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6364 
6365 	}
6366 
6367 	ext4_apply_options(fc, sb);
6368 
6369 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6370 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6371 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6372 			 "during remount not supported; ignoring");
6373 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6374 	}
6375 
6376 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6377 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6378 			ext4_msg(sb, KERN_ERR, "can't mount with "
6379 				 "both data=journal and delalloc");
6380 			err = -EINVAL;
6381 			goto restore_opts;
6382 		}
6383 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6384 			ext4_msg(sb, KERN_ERR, "can't mount with "
6385 				 "both data=journal and dioread_nolock");
6386 			err = -EINVAL;
6387 			goto restore_opts;
6388 		}
6389 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6390 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6391 			ext4_msg(sb, KERN_ERR, "can't mount with "
6392 				"journal_async_commit in data=ordered mode");
6393 			err = -EINVAL;
6394 			goto restore_opts;
6395 		}
6396 	}
6397 
6398 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6399 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6400 		err = -EINVAL;
6401 		goto restore_opts;
6402 	}
6403 
6404 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6405 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6406 
6407 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6408 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6409 
6410 	es = sbi->s_es;
6411 
6412 	if (sbi->s_journal) {
6413 		ext4_init_journal_params(sb, sbi->s_journal);
6414 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6415 	}
6416 
6417 	/* Flush outstanding errors before changing fs state */
6418 	flush_work(&sbi->s_error_work);
6419 
6420 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6421 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6422 			err = -EROFS;
6423 			goto restore_opts;
6424 		}
6425 
6426 		if (fc->sb_flags & SB_RDONLY) {
6427 			err = sync_filesystem(sb);
6428 			if (err < 0)
6429 				goto restore_opts;
6430 			err = dquot_suspend(sb, -1);
6431 			if (err < 0)
6432 				goto restore_opts;
6433 
6434 			/*
6435 			 * First of all, the unconditional stuff we have to do
6436 			 * to disable replay of the journal when we next remount
6437 			 */
6438 			sb->s_flags |= SB_RDONLY;
6439 
6440 			/*
6441 			 * OK, test if we are remounting a valid rw partition
6442 			 * readonly, and if so set the rdonly flag and then
6443 			 * mark the partition as valid again.
6444 			 */
6445 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6446 			    (sbi->s_mount_state & EXT4_VALID_FS))
6447 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6448 
6449 			if (sbi->s_journal) {
6450 				/*
6451 				 * We let remount-ro finish even if marking fs
6452 				 * as clean failed...
6453 				 */
6454 				ext4_mark_recovery_complete(sb, es);
6455 			}
6456 		} else {
6457 			/* Make sure we can mount this feature set readwrite */
6458 			if (ext4_has_feature_readonly(sb) ||
6459 			    !ext4_feature_set_ok(sb, 0)) {
6460 				err = -EROFS;
6461 				goto restore_opts;
6462 			}
6463 			/*
6464 			 * Make sure the group descriptor checksums
6465 			 * are sane.  If they aren't, refuse to remount r/w.
6466 			 */
6467 			for (g = 0; g < sbi->s_groups_count; g++) {
6468 				struct ext4_group_desc *gdp =
6469 					ext4_get_group_desc(sb, g, NULL);
6470 
6471 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6472 					ext4_msg(sb, KERN_ERR,
6473 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6474 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6475 					       le16_to_cpu(gdp->bg_checksum));
6476 					err = -EFSBADCRC;
6477 					goto restore_opts;
6478 				}
6479 			}
6480 
6481 			/*
6482 			 * If we have an unprocessed orphan list hanging
6483 			 * around from a previously readonly bdev mount,
6484 			 * require a full umount/remount for now.
6485 			 */
6486 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6487 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6488 				       "remount RDWR because of unprocessed "
6489 				       "orphan inode list.  Please "
6490 				       "umount/remount instead");
6491 				err = -EINVAL;
6492 				goto restore_opts;
6493 			}
6494 
6495 			/*
6496 			 * Mounting a RDONLY partition read-write, so reread
6497 			 * and store the current valid flag.  (It may have
6498 			 * been changed by e2fsck since we originally mounted
6499 			 * the partition.)
6500 			 */
6501 			if (sbi->s_journal) {
6502 				err = ext4_clear_journal_err(sb, es);
6503 				if (err)
6504 					goto restore_opts;
6505 			}
6506 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6507 					      ~EXT4_FC_REPLAY);
6508 
6509 			err = ext4_setup_super(sb, es, 0);
6510 			if (err)
6511 				goto restore_opts;
6512 
6513 			sb->s_flags &= ~SB_RDONLY;
6514 			if (ext4_has_feature_mmp(sb))
6515 				if (ext4_multi_mount_protect(sb,
6516 						le64_to_cpu(es->s_mmp_block))) {
6517 					err = -EROFS;
6518 					goto restore_opts;
6519 				}
6520 #ifdef CONFIG_QUOTA
6521 			enable_quota = 1;
6522 #endif
6523 		}
6524 	}
6525 
6526 	/*
6527 	 * Reinitialize lazy itable initialization thread based on
6528 	 * current settings
6529 	 */
6530 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6531 		ext4_unregister_li_request(sb);
6532 	else {
6533 		ext4_group_t first_not_zeroed;
6534 		first_not_zeroed = ext4_has_uninit_itable(sb);
6535 		ext4_register_li_request(sb, first_not_zeroed);
6536 	}
6537 
6538 	/*
6539 	 * Handle creation of system zone data early because it can fail.
6540 	 * Releasing of existing data is done when we are sure remount will
6541 	 * succeed.
6542 	 */
6543 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6544 		err = ext4_setup_system_zone(sb);
6545 		if (err)
6546 			goto restore_opts;
6547 	}
6548 
6549 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6550 		err = ext4_commit_super(sb);
6551 		if (err)
6552 			goto restore_opts;
6553 	}
6554 
6555 #ifdef CONFIG_QUOTA
6556 	/* Release old quota file names */
6557 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6558 		kfree(old_opts.s_qf_names[i]);
6559 	if (enable_quota) {
6560 		if (sb_any_quota_suspended(sb))
6561 			dquot_resume(sb, -1);
6562 		else if (ext4_has_feature_quota(sb)) {
6563 			err = ext4_enable_quotas(sb);
6564 			if (err)
6565 				goto restore_opts;
6566 		}
6567 	}
6568 #endif
6569 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6570 		ext4_release_system_zone(sb);
6571 
6572 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6573 		ext4_stop_mmpd(sbi);
6574 
6575 	return 0;
6576 
6577 restore_opts:
6578 	sb->s_flags = old_sb_flags;
6579 	sbi->s_mount_opt = old_opts.s_mount_opt;
6580 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6581 	sbi->s_resuid = old_opts.s_resuid;
6582 	sbi->s_resgid = old_opts.s_resgid;
6583 	sbi->s_commit_interval = old_opts.s_commit_interval;
6584 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6585 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6586 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6587 		ext4_release_system_zone(sb);
6588 #ifdef CONFIG_QUOTA
6589 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6590 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6591 		to_free[i] = get_qf_name(sb, sbi, i);
6592 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6593 	}
6594 	synchronize_rcu();
6595 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6596 		kfree(to_free[i]);
6597 #endif
6598 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6599 		ext4_stop_mmpd(sbi);
6600 	return err;
6601 }
6602 
6603 static int ext4_reconfigure(struct fs_context *fc)
6604 {
6605 	struct super_block *sb = fc->root->d_sb;
6606 	int ret;
6607 
6608 	fc->s_fs_info = EXT4_SB(sb);
6609 
6610 	ret = ext4_check_opt_consistency(fc, sb);
6611 	if (ret < 0)
6612 		return ret;
6613 
6614 	ret = __ext4_remount(fc, sb);
6615 	if (ret < 0)
6616 		return ret;
6617 
6618 	ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6619 		 ext4_quota_mode(sb));
6620 
6621 	return 0;
6622 }
6623 
6624 #ifdef CONFIG_QUOTA
6625 static int ext4_statfs_project(struct super_block *sb,
6626 			       kprojid_t projid, struct kstatfs *buf)
6627 {
6628 	struct kqid qid;
6629 	struct dquot *dquot;
6630 	u64 limit;
6631 	u64 curblock;
6632 
6633 	qid = make_kqid_projid(projid);
6634 	dquot = dqget(sb, qid);
6635 	if (IS_ERR(dquot))
6636 		return PTR_ERR(dquot);
6637 	spin_lock(&dquot->dq_dqb_lock);
6638 
6639 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6640 			     dquot->dq_dqb.dqb_bhardlimit);
6641 	limit >>= sb->s_blocksize_bits;
6642 
6643 	if (limit && buf->f_blocks > limit) {
6644 		curblock = (dquot->dq_dqb.dqb_curspace +
6645 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6646 		buf->f_blocks = limit;
6647 		buf->f_bfree = buf->f_bavail =
6648 			(buf->f_blocks > curblock) ?
6649 			 (buf->f_blocks - curblock) : 0;
6650 	}
6651 
6652 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6653 			     dquot->dq_dqb.dqb_ihardlimit);
6654 	if (limit && buf->f_files > limit) {
6655 		buf->f_files = limit;
6656 		buf->f_ffree =
6657 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6658 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6659 	}
6660 
6661 	spin_unlock(&dquot->dq_dqb_lock);
6662 	dqput(dquot);
6663 	return 0;
6664 }
6665 #endif
6666 
6667 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6668 {
6669 	struct super_block *sb = dentry->d_sb;
6670 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6671 	struct ext4_super_block *es = sbi->s_es;
6672 	ext4_fsblk_t overhead = 0, resv_blocks;
6673 	s64 bfree;
6674 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6675 
6676 	if (!test_opt(sb, MINIX_DF))
6677 		overhead = sbi->s_overhead;
6678 
6679 	buf->f_type = EXT4_SUPER_MAGIC;
6680 	buf->f_bsize = sb->s_blocksize;
6681 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6682 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6683 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6684 	/* prevent underflow in case that few free space is available */
6685 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6686 	buf->f_bavail = buf->f_bfree -
6687 			(ext4_r_blocks_count(es) + resv_blocks);
6688 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6689 		buf->f_bavail = 0;
6690 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6691 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6692 	buf->f_namelen = EXT4_NAME_LEN;
6693 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6694 
6695 #ifdef CONFIG_QUOTA
6696 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6697 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6698 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6699 #endif
6700 	return 0;
6701 }
6702 
6703 
6704 #ifdef CONFIG_QUOTA
6705 
6706 /*
6707  * Helper functions so that transaction is started before we acquire dqio_sem
6708  * to keep correct lock ordering of transaction > dqio_sem
6709  */
6710 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6711 {
6712 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6713 }
6714 
6715 static int ext4_write_dquot(struct dquot *dquot)
6716 {
6717 	int ret, err;
6718 	handle_t *handle;
6719 	struct inode *inode;
6720 
6721 	inode = dquot_to_inode(dquot);
6722 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6723 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6724 	if (IS_ERR(handle))
6725 		return PTR_ERR(handle);
6726 	ret = dquot_commit(dquot);
6727 	err = ext4_journal_stop(handle);
6728 	if (!ret)
6729 		ret = err;
6730 	return ret;
6731 }
6732 
6733 static int ext4_acquire_dquot(struct dquot *dquot)
6734 {
6735 	int ret, err;
6736 	handle_t *handle;
6737 
6738 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6739 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6740 	if (IS_ERR(handle))
6741 		return PTR_ERR(handle);
6742 	ret = dquot_acquire(dquot);
6743 	err = ext4_journal_stop(handle);
6744 	if (!ret)
6745 		ret = err;
6746 	return ret;
6747 }
6748 
6749 static int ext4_release_dquot(struct dquot *dquot)
6750 {
6751 	int ret, err;
6752 	handle_t *handle;
6753 
6754 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6755 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6756 	if (IS_ERR(handle)) {
6757 		/* Release dquot anyway to avoid endless cycle in dqput() */
6758 		dquot_release(dquot);
6759 		return PTR_ERR(handle);
6760 	}
6761 	ret = dquot_release(dquot);
6762 	err = ext4_journal_stop(handle);
6763 	if (!ret)
6764 		ret = err;
6765 	return ret;
6766 }
6767 
6768 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6769 {
6770 	struct super_block *sb = dquot->dq_sb;
6771 
6772 	if (ext4_is_quota_journalled(sb)) {
6773 		dquot_mark_dquot_dirty(dquot);
6774 		return ext4_write_dquot(dquot);
6775 	} else {
6776 		return dquot_mark_dquot_dirty(dquot);
6777 	}
6778 }
6779 
6780 static int ext4_write_info(struct super_block *sb, int type)
6781 {
6782 	int ret, err;
6783 	handle_t *handle;
6784 
6785 	/* Data block + inode block */
6786 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6787 	if (IS_ERR(handle))
6788 		return PTR_ERR(handle);
6789 	ret = dquot_commit_info(sb, type);
6790 	err = ext4_journal_stop(handle);
6791 	if (!ret)
6792 		ret = err;
6793 	return ret;
6794 }
6795 
6796 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6797 {
6798 	struct ext4_inode_info *ei = EXT4_I(inode);
6799 
6800 	/* The first argument of lockdep_set_subclass has to be
6801 	 * *exactly* the same as the argument to init_rwsem() --- in
6802 	 * this case, in init_once() --- or lockdep gets unhappy
6803 	 * because the name of the lock is set using the
6804 	 * stringification of the argument to init_rwsem().
6805 	 */
6806 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6807 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6808 }
6809 
6810 /*
6811  * Standard function to be called on quota_on
6812  */
6813 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6814 			 const struct path *path)
6815 {
6816 	int err;
6817 
6818 	if (!test_opt(sb, QUOTA))
6819 		return -EINVAL;
6820 
6821 	/* Quotafile not on the same filesystem? */
6822 	if (path->dentry->d_sb != sb)
6823 		return -EXDEV;
6824 
6825 	/* Quota already enabled for this file? */
6826 	if (IS_NOQUOTA(d_inode(path->dentry)))
6827 		return -EBUSY;
6828 
6829 	/* Journaling quota? */
6830 	if (EXT4_SB(sb)->s_qf_names[type]) {
6831 		/* Quotafile not in fs root? */
6832 		if (path->dentry->d_parent != sb->s_root)
6833 			ext4_msg(sb, KERN_WARNING,
6834 				"Quota file not on filesystem root. "
6835 				"Journaled quota will not work");
6836 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6837 	} else {
6838 		/*
6839 		 * Clear the flag just in case mount options changed since
6840 		 * last time.
6841 		 */
6842 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6843 	}
6844 
6845 	/*
6846 	 * When we journal data on quota file, we have to flush journal to see
6847 	 * all updates to the file when we bypass pagecache...
6848 	 */
6849 	if (EXT4_SB(sb)->s_journal &&
6850 	    ext4_should_journal_data(d_inode(path->dentry))) {
6851 		/*
6852 		 * We don't need to lock updates but journal_flush() could
6853 		 * otherwise be livelocked...
6854 		 */
6855 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6856 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6857 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6858 		if (err)
6859 			return err;
6860 	}
6861 
6862 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6863 	err = dquot_quota_on(sb, type, format_id, path);
6864 	if (!err) {
6865 		struct inode *inode = d_inode(path->dentry);
6866 		handle_t *handle;
6867 
6868 		/*
6869 		 * Set inode flags to prevent userspace from messing with quota
6870 		 * files. If this fails, we return success anyway since quotas
6871 		 * are already enabled and this is not a hard failure.
6872 		 */
6873 		inode_lock(inode);
6874 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6875 		if (IS_ERR(handle))
6876 			goto unlock_inode;
6877 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6878 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6879 				S_NOATIME | S_IMMUTABLE);
6880 		err = ext4_mark_inode_dirty(handle, inode);
6881 		ext4_journal_stop(handle);
6882 	unlock_inode:
6883 		inode_unlock(inode);
6884 		if (err)
6885 			dquot_quota_off(sb, type);
6886 	}
6887 	if (err)
6888 		lockdep_set_quota_inode(path->dentry->d_inode,
6889 					     I_DATA_SEM_NORMAL);
6890 	return err;
6891 }
6892 
6893 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6894 			     unsigned int flags)
6895 {
6896 	int err;
6897 	struct inode *qf_inode;
6898 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6899 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6900 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6901 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6902 	};
6903 
6904 	BUG_ON(!ext4_has_feature_quota(sb));
6905 
6906 	if (!qf_inums[type])
6907 		return -EPERM;
6908 
6909 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6910 	if (IS_ERR(qf_inode)) {
6911 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6912 		return PTR_ERR(qf_inode);
6913 	}
6914 
6915 	/* Don't account quota for quota files to avoid recursion */
6916 	qf_inode->i_flags |= S_NOQUOTA;
6917 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6918 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6919 	if (err)
6920 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6921 	iput(qf_inode);
6922 
6923 	return err;
6924 }
6925 
6926 /* Enable usage tracking for all quota types. */
6927 int ext4_enable_quotas(struct super_block *sb)
6928 {
6929 	int type, err = 0;
6930 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6931 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6932 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6933 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6934 	};
6935 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6936 		test_opt(sb, USRQUOTA),
6937 		test_opt(sb, GRPQUOTA),
6938 		test_opt(sb, PRJQUOTA),
6939 	};
6940 
6941 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6942 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6943 		if (qf_inums[type]) {
6944 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6945 				DQUOT_USAGE_ENABLED |
6946 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6947 			if (err) {
6948 				ext4_warning(sb,
6949 					"Failed to enable quota tracking "
6950 					"(type=%d, err=%d). Please run "
6951 					"e2fsck to fix.", type, err);
6952 				for (type--; type >= 0; type--) {
6953 					struct inode *inode;
6954 
6955 					inode = sb_dqopt(sb)->files[type];
6956 					if (inode)
6957 						inode = igrab(inode);
6958 					dquot_quota_off(sb, type);
6959 					if (inode) {
6960 						lockdep_set_quota_inode(inode,
6961 							I_DATA_SEM_NORMAL);
6962 						iput(inode);
6963 					}
6964 				}
6965 
6966 				return err;
6967 			}
6968 		}
6969 	}
6970 	return 0;
6971 }
6972 
6973 static int ext4_quota_off(struct super_block *sb, int type)
6974 {
6975 	struct inode *inode = sb_dqopt(sb)->files[type];
6976 	handle_t *handle;
6977 	int err;
6978 
6979 	/* Force all delayed allocation blocks to be allocated.
6980 	 * Caller already holds s_umount sem */
6981 	if (test_opt(sb, DELALLOC))
6982 		sync_filesystem(sb);
6983 
6984 	if (!inode || !igrab(inode))
6985 		goto out;
6986 
6987 	err = dquot_quota_off(sb, type);
6988 	if (err || ext4_has_feature_quota(sb))
6989 		goto out_put;
6990 
6991 	inode_lock(inode);
6992 	/*
6993 	 * Update modification times of quota files when userspace can
6994 	 * start looking at them. If we fail, we return success anyway since
6995 	 * this is not a hard failure and quotas are already disabled.
6996 	 */
6997 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6998 	if (IS_ERR(handle)) {
6999 		err = PTR_ERR(handle);
7000 		goto out_unlock;
7001 	}
7002 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7003 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7004 	inode->i_mtime = inode->i_ctime = current_time(inode);
7005 	err = ext4_mark_inode_dirty(handle, inode);
7006 	ext4_journal_stop(handle);
7007 out_unlock:
7008 	inode_unlock(inode);
7009 out_put:
7010 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7011 	iput(inode);
7012 	return err;
7013 out:
7014 	return dquot_quota_off(sb, type);
7015 }
7016 
7017 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7018  * acquiring the locks... As quota files are never truncated and quota code
7019  * itself serializes the operations (and no one else should touch the files)
7020  * we don't have to be afraid of races */
7021 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7022 			       size_t len, loff_t off)
7023 {
7024 	struct inode *inode = sb_dqopt(sb)->files[type];
7025 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7026 	int offset = off & (sb->s_blocksize - 1);
7027 	int tocopy;
7028 	size_t toread;
7029 	struct buffer_head *bh;
7030 	loff_t i_size = i_size_read(inode);
7031 
7032 	if (off > i_size)
7033 		return 0;
7034 	if (off+len > i_size)
7035 		len = i_size-off;
7036 	toread = len;
7037 	while (toread > 0) {
7038 		tocopy = sb->s_blocksize - offset < toread ?
7039 				sb->s_blocksize - offset : toread;
7040 		bh = ext4_bread(NULL, inode, blk, 0);
7041 		if (IS_ERR(bh))
7042 			return PTR_ERR(bh);
7043 		if (!bh)	/* A hole? */
7044 			memset(data, 0, tocopy);
7045 		else
7046 			memcpy(data, bh->b_data+offset, tocopy);
7047 		brelse(bh);
7048 		offset = 0;
7049 		toread -= tocopy;
7050 		data += tocopy;
7051 		blk++;
7052 	}
7053 	return len;
7054 }
7055 
7056 /* Write to quotafile (we know the transaction is already started and has
7057  * enough credits) */
7058 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7059 				const char *data, size_t len, loff_t off)
7060 {
7061 	struct inode *inode = sb_dqopt(sb)->files[type];
7062 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7063 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7064 	int retries = 0;
7065 	struct buffer_head *bh;
7066 	handle_t *handle = journal_current_handle();
7067 
7068 	if (!handle) {
7069 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7070 			" cancelled because transaction is not started",
7071 			(unsigned long long)off, (unsigned long long)len);
7072 		return -EIO;
7073 	}
7074 	/*
7075 	 * Since we account only one data block in transaction credits,
7076 	 * then it is impossible to cross a block boundary.
7077 	 */
7078 	if (sb->s_blocksize - offset < len) {
7079 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7080 			" cancelled because not block aligned",
7081 			(unsigned long long)off, (unsigned long long)len);
7082 		return -EIO;
7083 	}
7084 
7085 	do {
7086 		bh = ext4_bread(handle, inode, blk,
7087 				EXT4_GET_BLOCKS_CREATE |
7088 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7089 	} while (PTR_ERR(bh) == -ENOSPC &&
7090 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7091 	if (IS_ERR(bh))
7092 		return PTR_ERR(bh);
7093 	if (!bh)
7094 		goto out;
7095 	BUFFER_TRACE(bh, "get write access");
7096 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7097 	if (err) {
7098 		brelse(bh);
7099 		return err;
7100 	}
7101 	lock_buffer(bh);
7102 	memcpy(bh->b_data+offset, data, len);
7103 	flush_dcache_page(bh->b_page);
7104 	unlock_buffer(bh);
7105 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7106 	brelse(bh);
7107 out:
7108 	if (inode->i_size < off + len) {
7109 		i_size_write(inode, off + len);
7110 		EXT4_I(inode)->i_disksize = inode->i_size;
7111 		err2 = ext4_mark_inode_dirty(handle, inode);
7112 		if (unlikely(err2 && !err))
7113 			err = err2;
7114 	}
7115 	return err ? err : len;
7116 }
7117 #endif
7118 
7119 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7120 static inline void register_as_ext2(void)
7121 {
7122 	int err = register_filesystem(&ext2_fs_type);
7123 	if (err)
7124 		printk(KERN_WARNING
7125 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7126 }
7127 
7128 static inline void unregister_as_ext2(void)
7129 {
7130 	unregister_filesystem(&ext2_fs_type);
7131 }
7132 
7133 static inline int ext2_feature_set_ok(struct super_block *sb)
7134 {
7135 	if (ext4_has_unknown_ext2_incompat_features(sb))
7136 		return 0;
7137 	if (sb_rdonly(sb))
7138 		return 1;
7139 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7140 		return 0;
7141 	return 1;
7142 }
7143 #else
7144 static inline void register_as_ext2(void) { }
7145 static inline void unregister_as_ext2(void) { }
7146 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7147 #endif
7148 
7149 static inline void register_as_ext3(void)
7150 {
7151 	int err = register_filesystem(&ext3_fs_type);
7152 	if (err)
7153 		printk(KERN_WARNING
7154 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7155 }
7156 
7157 static inline void unregister_as_ext3(void)
7158 {
7159 	unregister_filesystem(&ext3_fs_type);
7160 }
7161 
7162 static inline int ext3_feature_set_ok(struct super_block *sb)
7163 {
7164 	if (ext4_has_unknown_ext3_incompat_features(sb))
7165 		return 0;
7166 	if (!ext4_has_feature_journal(sb))
7167 		return 0;
7168 	if (sb_rdonly(sb))
7169 		return 1;
7170 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7171 		return 0;
7172 	return 1;
7173 }
7174 
7175 static struct file_system_type ext4_fs_type = {
7176 	.owner			= THIS_MODULE,
7177 	.name			= "ext4",
7178 	.init_fs_context	= ext4_init_fs_context,
7179 	.parameters		= ext4_param_specs,
7180 	.kill_sb		= kill_block_super,
7181 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7182 };
7183 MODULE_ALIAS_FS("ext4");
7184 
7185 /* Shared across all ext4 file systems */
7186 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7187 
7188 static int __init ext4_init_fs(void)
7189 {
7190 	int i, err;
7191 
7192 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7193 	ext4_li_info = NULL;
7194 
7195 	/* Build-time check for flags consistency */
7196 	ext4_check_flag_values();
7197 
7198 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7199 		init_waitqueue_head(&ext4__ioend_wq[i]);
7200 
7201 	err = ext4_init_es();
7202 	if (err)
7203 		return err;
7204 
7205 	err = ext4_init_pending();
7206 	if (err)
7207 		goto out7;
7208 
7209 	err = ext4_init_post_read_processing();
7210 	if (err)
7211 		goto out6;
7212 
7213 	err = ext4_init_pageio();
7214 	if (err)
7215 		goto out5;
7216 
7217 	err = ext4_init_system_zone();
7218 	if (err)
7219 		goto out4;
7220 
7221 	err = ext4_init_sysfs();
7222 	if (err)
7223 		goto out3;
7224 
7225 	err = ext4_init_mballoc();
7226 	if (err)
7227 		goto out2;
7228 	err = init_inodecache();
7229 	if (err)
7230 		goto out1;
7231 
7232 	err = ext4_fc_init_dentry_cache();
7233 	if (err)
7234 		goto out05;
7235 
7236 	register_as_ext3();
7237 	register_as_ext2();
7238 	err = register_filesystem(&ext4_fs_type);
7239 	if (err)
7240 		goto out;
7241 
7242 	return 0;
7243 out:
7244 	unregister_as_ext2();
7245 	unregister_as_ext3();
7246 	ext4_fc_destroy_dentry_cache();
7247 out05:
7248 	destroy_inodecache();
7249 out1:
7250 	ext4_exit_mballoc();
7251 out2:
7252 	ext4_exit_sysfs();
7253 out3:
7254 	ext4_exit_system_zone();
7255 out4:
7256 	ext4_exit_pageio();
7257 out5:
7258 	ext4_exit_post_read_processing();
7259 out6:
7260 	ext4_exit_pending();
7261 out7:
7262 	ext4_exit_es();
7263 
7264 	return err;
7265 }
7266 
7267 static void __exit ext4_exit_fs(void)
7268 {
7269 	ext4_destroy_lazyinit_thread();
7270 	unregister_as_ext2();
7271 	unregister_as_ext3();
7272 	unregister_filesystem(&ext4_fs_type);
7273 	ext4_fc_destroy_dentry_cache();
7274 	destroy_inodecache();
7275 	ext4_exit_mballoc();
7276 	ext4_exit_sysfs();
7277 	ext4_exit_system_zone();
7278 	ext4_exit_pageio();
7279 	ext4_exit_post_read_processing();
7280 	ext4_exit_es();
7281 	ext4_exit_pending();
7282 }
7283 
7284 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7285 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7286 MODULE_LICENSE("GPL");
7287 MODULE_SOFTDEP("pre: crc32c");
7288 module_init(ext4_init_fs)
7289 module_exit(ext4_exit_fs)
7290