xref: /openbmc/linux/fs/ext4/super.c (revision 1edd0337)
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 folio *folio,
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 = folio_buffers(folio);
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 			folio_redirty_for_writepage(wbc, folio);
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 = ext4_normal_submit_inode_data_buffers(jinode);
544 	return ret;
545 }
546 
547 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
548 {
549 	int ret = 0;
550 
551 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
552 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
553 
554 	return ret;
555 }
556 
557 static bool system_going_down(void)
558 {
559 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
560 		|| system_state == SYSTEM_RESTART;
561 }
562 
563 struct ext4_err_translation {
564 	int code;
565 	int errno;
566 };
567 
568 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
569 
570 static struct ext4_err_translation err_translation[] = {
571 	EXT4_ERR_TRANSLATE(EIO),
572 	EXT4_ERR_TRANSLATE(ENOMEM),
573 	EXT4_ERR_TRANSLATE(EFSBADCRC),
574 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
575 	EXT4_ERR_TRANSLATE(ENOSPC),
576 	EXT4_ERR_TRANSLATE(ENOKEY),
577 	EXT4_ERR_TRANSLATE(EROFS),
578 	EXT4_ERR_TRANSLATE(EFBIG),
579 	EXT4_ERR_TRANSLATE(EEXIST),
580 	EXT4_ERR_TRANSLATE(ERANGE),
581 	EXT4_ERR_TRANSLATE(EOVERFLOW),
582 	EXT4_ERR_TRANSLATE(EBUSY),
583 	EXT4_ERR_TRANSLATE(ENOTDIR),
584 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
585 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
586 	EXT4_ERR_TRANSLATE(EFAULT),
587 };
588 
589 static int ext4_errno_to_code(int errno)
590 {
591 	int i;
592 
593 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
594 		if (err_translation[i].errno == errno)
595 			return err_translation[i].code;
596 	return EXT4_ERR_UNKNOWN;
597 }
598 
599 static void save_error_info(struct super_block *sb, int error,
600 			    __u32 ino, __u64 block,
601 			    const char *func, unsigned int line)
602 {
603 	struct ext4_sb_info *sbi = EXT4_SB(sb);
604 
605 	/* We default to EFSCORRUPTED error... */
606 	if (error == 0)
607 		error = EFSCORRUPTED;
608 
609 	spin_lock(&sbi->s_error_lock);
610 	sbi->s_add_error_count++;
611 	sbi->s_last_error_code = error;
612 	sbi->s_last_error_line = line;
613 	sbi->s_last_error_ino = ino;
614 	sbi->s_last_error_block = block;
615 	sbi->s_last_error_func = func;
616 	sbi->s_last_error_time = ktime_get_real_seconds();
617 	if (!sbi->s_first_error_time) {
618 		sbi->s_first_error_code = error;
619 		sbi->s_first_error_line = line;
620 		sbi->s_first_error_ino = ino;
621 		sbi->s_first_error_block = block;
622 		sbi->s_first_error_func = func;
623 		sbi->s_first_error_time = sbi->s_last_error_time;
624 	}
625 	spin_unlock(&sbi->s_error_lock);
626 }
627 
628 /* Deal with the reporting of failure conditions on a filesystem such as
629  * inconsistencies detected or read IO failures.
630  *
631  * On ext2, we can store the error state of the filesystem in the
632  * superblock.  That is not possible on ext4, because we may have other
633  * write ordering constraints on the superblock which prevent us from
634  * writing it out straight away; and given that the journal is about to
635  * be aborted, we can't rely on the current, or future, transactions to
636  * write out the superblock safely.
637  *
638  * We'll just use the jbd2_journal_abort() error code to record an error in
639  * the journal instead.  On recovery, the journal will complain about
640  * that error until we've noted it down and cleared it.
641  *
642  * If force_ro is set, we unconditionally force the filesystem into an
643  * ABORT|READONLY state, unless the error response on the fs has been set to
644  * panic in which case we take the easy way out and panic immediately. This is
645  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
646  * at a critical moment in log management.
647  */
648 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
649 			      __u32 ino, __u64 block,
650 			      const char *func, unsigned int line)
651 {
652 	journal_t *journal = EXT4_SB(sb)->s_journal;
653 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
654 
655 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
656 	if (test_opt(sb, WARN_ON_ERROR))
657 		WARN_ON_ONCE(1);
658 
659 	if (!continue_fs && !sb_rdonly(sb)) {
660 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
661 		if (journal)
662 			jbd2_journal_abort(journal, -EIO);
663 	}
664 
665 	if (!bdev_read_only(sb->s_bdev)) {
666 		save_error_info(sb, error, ino, block, func, line);
667 		/*
668 		 * In case the fs should keep running, we need to writeout
669 		 * superblock through the journal. Due to lock ordering
670 		 * constraints, it may not be safe to do it right here so we
671 		 * defer superblock flushing to a workqueue.
672 		 */
673 		if (continue_fs && journal)
674 			schedule_work(&EXT4_SB(sb)->s_error_work);
675 		else
676 			ext4_commit_super(sb);
677 	}
678 
679 	/*
680 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
681 	 * could panic during 'reboot -f' as the underlying device got already
682 	 * disabled.
683 	 */
684 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
685 		panic("EXT4-fs (device %s): panic forced after error\n",
686 			sb->s_id);
687 	}
688 
689 	if (sb_rdonly(sb) || continue_fs)
690 		return;
691 
692 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
693 	/*
694 	 * Make sure updated value of ->s_mount_flags will be visible before
695 	 * ->s_flags update
696 	 */
697 	smp_wmb();
698 	sb->s_flags |= SB_RDONLY;
699 }
700 
701 static void flush_stashed_error_work(struct work_struct *work)
702 {
703 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
704 						s_error_work);
705 	journal_t *journal = sbi->s_journal;
706 	handle_t *handle;
707 
708 	/*
709 	 * If the journal is still running, we have to write out superblock
710 	 * through the journal to avoid collisions of other journalled sb
711 	 * updates.
712 	 *
713 	 * We use directly jbd2 functions here to avoid recursing back into
714 	 * ext4 error handling code during handling of previous errors.
715 	 */
716 	if (!sb_rdonly(sbi->s_sb) && journal) {
717 		struct buffer_head *sbh = sbi->s_sbh;
718 		handle = jbd2_journal_start(journal, 1);
719 		if (IS_ERR(handle))
720 			goto write_directly;
721 		if (jbd2_journal_get_write_access(handle, sbh)) {
722 			jbd2_journal_stop(handle);
723 			goto write_directly;
724 		}
725 		ext4_update_super(sbi->s_sb);
726 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
727 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
728 				 "superblock detected");
729 			clear_buffer_write_io_error(sbh);
730 			set_buffer_uptodate(sbh);
731 		}
732 
733 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
734 			jbd2_journal_stop(handle);
735 			goto write_directly;
736 		}
737 		jbd2_journal_stop(handle);
738 		ext4_notify_error_sysfs(sbi);
739 		return;
740 	}
741 write_directly:
742 	/*
743 	 * Write through journal failed. Write sb directly to get error info
744 	 * out and hope for the best.
745 	 */
746 	ext4_commit_super(sbi->s_sb);
747 	ext4_notify_error_sysfs(sbi);
748 }
749 
750 #define ext4_error_ratelimit(sb)					\
751 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
752 			     "EXT4-fs error")
753 
754 void __ext4_error(struct super_block *sb, const char *function,
755 		  unsigned int line, bool force_ro, int error, __u64 block,
756 		  const char *fmt, ...)
757 {
758 	struct va_format vaf;
759 	va_list args;
760 
761 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
762 		return;
763 
764 	trace_ext4_error(sb, function, line);
765 	if (ext4_error_ratelimit(sb)) {
766 		va_start(args, fmt);
767 		vaf.fmt = fmt;
768 		vaf.va = &args;
769 		printk(KERN_CRIT
770 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
771 		       sb->s_id, function, line, current->comm, &vaf);
772 		va_end(args);
773 	}
774 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
775 
776 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
777 }
778 
779 void __ext4_error_inode(struct inode *inode, const char *function,
780 			unsigned int line, ext4_fsblk_t block, int error,
781 			const char *fmt, ...)
782 {
783 	va_list args;
784 	struct va_format vaf;
785 
786 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
787 		return;
788 
789 	trace_ext4_error(inode->i_sb, function, line);
790 	if (ext4_error_ratelimit(inode->i_sb)) {
791 		va_start(args, fmt);
792 		vaf.fmt = fmt;
793 		vaf.va = &args;
794 		if (block)
795 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
796 			       "inode #%lu: block %llu: comm %s: %pV\n",
797 			       inode->i_sb->s_id, function, line, inode->i_ino,
798 			       block, current->comm, &vaf);
799 		else
800 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
801 			       "inode #%lu: comm %s: %pV\n",
802 			       inode->i_sb->s_id, function, line, inode->i_ino,
803 			       current->comm, &vaf);
804 		va_end(args);
805 	}
806 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
807 
808 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
809 			  function, line);
810 }
811 
812 void __ext4_error_file(struct file *file, const char *function,
813 		       unsigned int line, ext4_fsblk_t block,
814 		       const char *fmt, ...)
815 {
816 	va_list args;
817 	struct va_format vaf;
818 	struct inode *inode = file_inode(file);
819 	char pathname[80], *path;
820 
821 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
822 		return;
823 
824 	trace_ext4_error(inode->i_sb, function, line);
825 	if (ext4_error_ratelimit(inode->i_sb)) {
826 		path = file_path(file, pathname, sizeof(pathname));
827 		if (IS_ERR(path))
828 			path = "(unknown)";
829 		va_start(args, fmt);
830 		vaf.fmt = fmt;
831 		vaf.va = &args;
832 		if (block)
833 			printk(KERN_CRIT
834 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
835 			       "block %llu: comm %s: path %s: %pV\n",
836 			       inode->i_sb->s_id, function, line, inode->i_ino,
837 			       block, current->comm, path, &vaf);
838 		else
839 			printk(KERN_CRIT
840 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
841 			       "comm %s: path %s: %pV\n",
842 			       inode->i_sb->s_id, function, line, inode->i_ino,
843 			       current->comm, path, &vaf);
844 		va_end(args);
845 	}
846 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
847 
848 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
849 			  function, line);
850 }
851 
852 const char *ext4_decode_error(struct super_block *sb, int errno,
853 			      char nbuf[16])
854 {
855 	char *errstr = NULL;
856 
857 	switch (errno) {
858 	case -EFSCORRUPTED:
859 		errstr = "Corrupt filesystem";
860 		break;
861 	case -EFSBADCRC:
862 		errstr = "Filesystem failed CRC";
863 		break;
864 	case -EIO:
865 		errstr = "IO failure";
866 		break;
867 	case -ENOMEM:
868 		errstr = "Out of memory";
869 		break;
870 	case -EROFS:
871 		if (!sb || (EXT4_SB(sb)->s_journal &&
872 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
873 			errstr = "Journal has aborted";
874 		else
875 			errstr = "Readonly filesystem";
876 		break;
877 	default:
878 		/* If the caller passed in an extra buffer for unknown
879 		 * errors, textualise them now.  Else we just return
880 		 * NULL. */
881 		if (nbuf) {
882 			/* Check for truncated error codes... */
883 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
884 				errstr = nbuf;
885 		}
886 		break;
887 	}
888 
889 	return errstr;
890 }
891 
892 /* __ext4_std_error decodes expected errors from journaling functions
893  * automatically and invokes the appropriate error response.  */
894 
895 void __ext4_std_error(struct super_block *sb, const char *function,
896 		      unsigned int line, int errno)
897 {
898 	char nbuf[16];
899 	const char *errstr;
900 
901 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
902 		return;
903 
904 	/* Special case: if the error is EROFS, and we're not already
905 	 * inside a transaction, then there's really no point in logging
906 	 * an error. */
907 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
908 		return;
909 
910 	if (ext4_error_ratelimit(sb)) {
911 		errstr = ext4_decode_error(sb, errno, nbuf);
912 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
913 		       sb->s_id, function, line, errstr);
914 	}
915 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
916 
917 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
918 }
919 
920 void __ext4_msg(struct super_block *sb,
921 		const char *prefix, const char *fmt, ...)
922 {
923 	struct va_format vaf;
924 	va_list args;
925 
926 	if (sb) {
927 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
928 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
929 				  "EXT4-fs"))
930 			return;
931 	}
932 
933 	va_start(args, fmt);
934 	vaf.fmt = fmt;
935 	vaf.va = &args;
936 	if (sb)
937 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
938 	else
939 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
940 	va_end(args);
941 }
942 
943 static int ext4_warning_ratelimit(struct super_block *sb)
944 {
945 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
946 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
947 			    "EXT4-fs warning");
948 }
949 
950 void __ext4_warning(struct super_block *sb, const char *function,
951 		    unsigned int line, const char *fmt, ...)
952 {
953 	struct va_format vaf;
954 	va_list args;
955 
956 	if (!ext4_warning_ratelimit(sb))
957 		return;
958 
959 	va_start(args, fmt);
960 	vaf.fmt = fmt;
961 	vaf.va = &args;
962 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
963 	       sb->s_id, function, line, &vaf);
964 	va_end(args);
965 }
966 
967 void __ext4_warning_inode(const struct inode *inode, const char *function,
968 			  unsigned int line, const char *fmt, ...)
969 {
970 	struct va_format vaf;
971 	va_list args;
972 
973 	if (!ext4_warning_ratelimit(inode->i_sb))
974 		return;
975 
976 	va_start(args, fmt);
977 	vaf.fmt = fmt;
978 	vaf.va = &args;
979 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
980 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
981 	       function, line, inode->i_ino, current->comm, &vaf);
982 	va_end(args);
983 }
984 
985 void __ext4_grp_locked_error(const char *function, unsigned int line,
986 			     struct super_block *sb, ext4_group_t grp,
987 			     unsigned long ino, ext4_fsblk_t block,
988 			     const char *fmt, ...)
989 __releases(bitlock)
990 __acquires(bitlock)
991 {
992 	struct va_format vaf;
993 	va_list args;
994 
995 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
996 		return;
997 
998 	trace_ext4_error(sb, function, line);
999 	if (ext4_error_ratelimit(sb)) {
1000 		va_start(args, fmt);
1001 		vaf.fmt = fmt;
1002 		vaf.va = &args;
1003 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1004 		       sb->s_id, function, line, grp);
1005 		if (ino)
1006 			printk(KERN_CONT "inode %lu: ", ino);
1007 		if (block)
1008 			printk(KERN_CONT "block %llu:",
1009 			       (unsigned long long) block);
1010 		printk(KERN_CONT "%pV\n", &vaf);
1011 		va_end(args);
1012 	}
1013 
1014 	if (test_opt(sb, ERRORS_CONT)) {
1015 		if (test_opt(sb, WARN_ON_ERROR))
1016 			WARN_ON_ONCE(1);
1017 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1018 		if (!bdev_read_only(sb->s_bdev)) {
1019 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1020 					line);
1021 			schedule_work(&EXT4_SB(sb)->s_error_work);
1022 		}
1023 		return;
1024 	}
1025 	ext4_unlock_group(sb, grp);
1026 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1027 	/*
1028 	 * We only get here in the ERRORS_RO case; relocking the group
1029 	 * may be dangerous, but nothing bad will happen since the
1030 	 * filesystem will have already been marked read/only and the
1031 	 * journal has been aborted.  We return 1 as a hint to callers
1032 	 * who might what to use the return value from
1033 	 * ext4_grp_locked_error() to distinguish between the
1034 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1035 	 * aggressively from the ext4 function in question, with a
1036 	 * more appropriate error code.
1037 	 */
1038 	ext4_lock_group(sb, grp);
1039 	return;
1040 }
1041 
1042 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1043 				     ext4_group_t group,
1044 				     unsigned int flags)
1045 {
1046 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1047 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1048 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1049 	int ret;
1050 
1051 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1052 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1053 					    &grp->bb_state);
1054 		if (!ret)
1055 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1056 					   grp->bb_free);
1057 	}
1058 
1059 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1060 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1061 					    &grp->bb_state);
1062 		if (!ret && gdp) {
1063 			int count;
1064 
1065 			count = ext4_free_inodes_count(sb, gdp);
1066 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1067 					   count);
1068 		}
1069 	}
1070 }
1071 
1072 void ext4_update_dynamic_rev(struct super_block *sb)
1073 {
1074 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1075 
1076 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1077 		return;
1078 
1079 	ext4_warning(sb,
1080 		     "updating to rev %d because of new feature flag, "
1081 		     "running e2fsck is recommended",
1082 		     EXT4_DYNAMIC_REV);
1083 
1084 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1085 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1086 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1087 	/* leave es->s_feature_*compat flags alone */
1088 	/* es->s_uuid will be set by e2fsck if empty */
1089 
1090 	/*
1091 	 * The rest of the superblock fields should be zero, and if not it
1092 	 * means they are likely already in use, so leave them alone.  We
1093 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1094 	 */
1095 }
1096 
1097 /*
1098  * Open the external journal device
1099  */
1100 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1101 {
1102 	struct block_device *bdev;
1103 
1104 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1105 	if (IS_ERR(bdev))
1106 		goto fail;
1107 	return bdev;
1108 
1109 fail:
1110 	ext4_msg(sb, KERN_ERR,
1111 		 "failed to open journal device unknown-block(%u,%u) %ld",
1112 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1113 	return NULL;
1114 }
1115 
1116 /*
1117  * Release the journal device
1118  */
1119 static void ext4_blkdev_put(struct block_device *bdev)
1120 {
1121 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1122 }
1123 
1124 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1125 {
1126 	struct block_device *bdev;
1127 	bdev = sbi->s_journal_bdev;
1128 	if (bdev) {
1129 		ext4_blkdev_put(bdev);
1130 		sbi->s_journal_bdev = NULL;
1131 	}
1132 }
1133 
1134 static inline struct inode *orphan_list_entry(struct list_head *l)
1135 {
1136 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1137 }
1138 
1139 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1140 {
1141 	struct list_head *l;
1142 
1143 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1144 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1145 
1146 	printk(KERN_ERR "sb_info orphan list:\n");
1147 	list_for_each(l, &sbi->s_orphan) {
1148 		struct inode *inode = orphan_list_entry(l);
1149 		printk(KERN_ERR "  "
1150 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1151 		       inode->i_sb->s_id, inode->i_ino, inode,
1152 		       inode->i_mode, inode->i_nlink,
1153 		       NEXT_ORPHAN(inode));
1154 	}
1155 }
1156 
1157 #ifdef CONFIG_QUOTA
1158 static int ext4_quota_off(struct super_block *sb, int type);
1159 
1160 static inline void ext4_quota_off_umount(struct super_block *sb)
1161 {
1162 	int type;
1163 
1164 	/* Use our quota_off function to clear inode flags etc. */
1165 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1166 		ext4_quota_off(sb, type);
1167 }
1168 
1169 /*
1170  * This is a helper function which is used in the mount/remount
1171  * codepaths (which holds s_umount) to fetch the quota file name.
1172  */
1173 static inline char *get_qf_name(struct super_block *sb,
1174 				struct ext4_sb_info *sbi,
1175 				int type)
1176 {
1177 	return rcu_dereference_protected(sbi->s_qf_names[type],
1178 					 lockdep_is_held(&sb->s_umount));
1179 }
1180 #else
1181 static inline void ext4_quota_off_umount(struct super_block *sb)
1182 {
1183 }
1184 #endif
1185 
1186 static void ext4_put_super(struct super_block *sb)
1187 {
1188 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1189 	struct ext4_super_block *es = sbi->s_es;
1190 	struct buffer_head **group_desc;
1191 	struct flex_groups **flex_groups;
1192 	int aborted = 0;
1193 	int i, err;
1194 
1195 	/*
1196 	 * Unregister sysfs before destroying jbd2 journal.
1197 	 * Since we could still access attr_journal_task attribute via sysfs
1198 	 * path which could have sbi->s_journal->j_task as NULL
1199 	 * Unregister sysfs before flush sbi->s_error_work.
1200 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1201 	 * read metadata verify failed then will queue error work.
1202 	 * flush_stashed_error_work will call start_this_handle may trigger
1203 	 * BUG_ON.
1204 	 */
1205 	ext4_unregister_sysfs(sb);
1206 
1207 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1208 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1209 			 &sb->s_uuid);
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 	timer_shutdown_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 	ei->i_flags = 0;
1327 	spin_lock_init(&ei->i_raw_lock);
1328 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1329 	atomic_set(&ei->i_prealloc_active, 0);
1330 	spin_lock_init(&ei->i_prealloc_lock);
1331 	ext4_es_init_tree(&ei->i_es_tree);
1332 	rwlock_init(&ei->i_es_lock);
1333 	INIT_LIST_HEAD(&ei->i_es_list);
1334 	ei->i_es_all_nr = 0;
1335 	ei->i_es_shk_nr = 0;
1336 	ei->i_es_shrink_lblk = 0;
1337 	ei->i_reserved_data_blocks = 0;
1338 	spin_lock_init(&(ei->i_block_reservation_lock));
1339 	ext4_init_pending_tree(&ei->i_pending_tree);
1340 #ifdef CONFIG_QUOTA
1341 	ei->i_reserved_quota = 0;
1342 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1343 #endif
1344 	ei->jinode = NULL;
1345 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1346 	spin_lock_init(&ei->i_completed_io_lock);
1347 	ei->i_sync_tid = 0;
1348 	ei->i_datasync_tid = 0;
1349 	atomic_set(&ei->i_unwritten, 0);
1350 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1351 	ext4_fc_init_inode(&ei->vfs_inode);
1352 	mutex_init(&ei->i_fc_lock);
1353 	return &ei->vfs_inode;
1354 }
1355 
1356 static int ext4_drop_inode(struct inode *inode)
1357 {
1358 	int drop = generic_drop_inode(inode);
1359 
1360 	if (!drop)
1361 		drop = fscrypt_drop_inode(inode);
1362 
1363 	trace_ext4_drop_inode(inode, drop);
1364 	return drop;
1365 }
1366 
1367 static void ext4_free_in_core_inode(struct inode *inode)
1368 {
1369 	fscrypt_free_inode(inode);
1370 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1371 		pr_warn("%s: inode %ld still in fc list",
1372 			__func__, inode->i_ino);
1373 	}
1374 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1375 }
1376 
1377 static void ext4_destroy_inode(struct inode *inode)
1378 {
1379 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1380 		ext4_msg(inode->i_sb, KERN_ERR,
1381 			 "Inode %lu (%p): orphan list check failed!",
1382 			 inode->i_ino, EXT4_I(inode));
1383 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1384 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1385 				true);
1386 		dump_stack();
1387 	}
1388 
1389 	if (EXT4_I(inode)->i_reserved_data_blocks)
1390 		ext4_msg(inode->i_sb, KERN_ERR,
1391 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1392 			 inode->i_ino, EXT4_I(inode),
1393 			 EXT4_I(inode)->i_reserved_data_blocks);
1394 }
1395 
1396 static void init_once(void *foo)
1397 {
1398 	struct ext4_inode_info *ei = foo;
1399 
1400 	INIT_LIST_HEAD(&ei->i_orphan);
1401 	init_rwsem(&ei->xattr_sem);
1402 	init_rwsem(&ei->i_data_sem);
1403 	inode_init_once(&ei->vfs_inode);
1404 	ext4_fc_init_inode(&ei->vfs_inode);
1405 }
1406 
1407 static int __init init_inodecache(void)
1408 {
1409 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1410 				sizeof(struct ext4_inode_info), 0,
1411 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1412 					SLAB_ACCOUNT),
1413 				offsetof(struct ext4_inode_info, i_data),
1414 				sizeof_field(struct ext4_inode_info, i_data),
1415 				init_once);
1416 	if (ext4_inode_cachep == NULL)
1417 		return -ENOMEM;
1418 	return 0;
1419 }
1420 
1421 static void destroy_inodecache(void)
1422 {
1423 	/*
1424 	 * Make sure all delayed rcu free inodes are flushed before we
1425 	 * destroy cache.
1426 	 */
1427 	rcu_barrier();
1428 	kmem_cache_destroy(ext4_inode_cachep);
1429 }
1430 
1431 void ext4_clear_inode(struct inode *inode)
1432 {
1433 	ext4_fc_del(inode);
1434 	invalidate_inode_buffers(inode);
1435 	clear_inode(inode);
1436 	ext4_discard_preallocations(inode, 0);
1437 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1438 	dquot_drop(inode);
1439 	if (EXT4_I(inode)->jinode) {
1440 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1441 					       EXT4_I(inode)->jinode);
1442 		jbd2_free_inode(EXT4_I(inode)->jinode);
1443 		EXT4_I(inode)->jinode = NULL;
1444 	}
1445 	fscrypt_put_encryption_info(inode);
1446 	fsverity_cleanup_inode(inode);
1447 }
1448 
1449 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1450 					u64 ino, u32 generation)
1451 {
1452 	struct inode *inode;
1453 
1454 	/*
1455 	 * Currently we don't know the generation for parent directory, so
1456 	 * a generation of 0 means "accept any"
1457 	 */
1458 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1459 	if (IS_ERR(inode))
1460 		return ERR_CAST(inode);
1461 	if (generation && inode->i_generation != generation) {
1462 		iput(inode);
1463 		return ERR_PTR(-ESTALE);
1464 	}
1465 
1466 	return inode;
1467 }
1468 
1469 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1470 					int fh_len, int fh_type)
1471 {
1472 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1473 				    ext4_nfs_get_inode);
1474 }
1475 
1476 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1477 					int fh_len, int fh_type)
1478 {
1479 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1480 				    ext4_nfs_get_inode);
1481 }
1482 
1483 static int ext4_nfs_commit_metadata(struct inode *inode)
1484 {
1485 	struct writeback_control wbc = {
1486 		.sync_mode = WB_SYNC_ALL
1487 	};
1488 
1489 	trace_ext4_nfs_commit_metadata(inode);
1490 	return ext4_write_inode(inode, &wbc);
1491 }
1492 
1493 #ifdef CONFIG_QUOTA
1494 static const char * const quotatypes[] = INITQFNAMES;
1495 #define QTYPE2NAME(t) (quotatypes[t])
1496 
1497 static int ext4_write_dquot(struct dquot *dquot);
1498 static int ext4_acquire_dquot(struct dquot *dquot);
1499 static int ext4_release_dquot(struct dquot *dquot);
1500 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1501 static int ext4_write_info(struct super_block *sb, int type);
1502 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1503 			 const struct path *path);
1504 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1505 			       size_t len, loff_t off);
1506 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1507 				const char *data, size_t len, loff_t off);
1508 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1509 			     unsigned int flags);
1510 
1511 static struct dquot **ext4_get_dquots(struct inode *inode)
1512 {
1513 	return EXT4_I(inode)->i_dquot;
1514 }
1515 
1516 static const struct dquot_operations ext4_quota_operations = {
1517 	.get_reserved_space	= ext4_get_reserved_space,
1518 	.write_dquot		= ext4_write_dquot,
1519 	.acquire_dquot		= ext4_acquire_dquot,
1520 	.release_dquot		= ext4_release_dquot,
1521 	.mark_dirty		= ext4_mark_dquot_dirty,
1522 	.write_info		= ext4_write_info,
1523 	.alloc_dquot		= dquot_alloc,
1524 	.destroy_dquot		= dquot_destroy,
1525 	.get_projid		= ext4_get_projid,
1526 	.get_inode_usage	= ext4_get_inode_usage,
1527 	.get_next_id		= dquot_get_next_id,
1528 };
1529 
1530 static const struct quotactl_ops ext4_qctl_operations = {
1531 	.quota_on	= ext4_quota_on,
1532 	.quota_off	= ext4_quota_off,
1533 	.quota_sync	= dquot_quota_sync,
1534 	.get_state	= dquot_get_state,
1535 	.set_info	= dquot_set_dqinfo,
1536 	.get_dqblk	= dquot_get_dqblk,
1537 	.set_dqblk	= dquot_set_dqblk,
1538 	.get_nextdqblk	= dquot_get_next_dqblk,
1539 };
1540 #endif
1541 
1542 static const struct super_operations ext4_sops = {
1543 	.alloc_inode	= ext4_alloc_inode,
1544 	.free_inode	= ext4_free_in_core_inode,
1545 	.destroy_inode	= ext4_destroy_inode,
1546 	.write_inode	= ext4_write_inode,
1547 	.dirty_inode	= ext4_dirty_inode,
1548 	.drop_inode	= ext4_drop_inode,
1549 	.evict_inode	= ext4_evict_inode,
1550 	.put_super	= ext4_put_super,
1551 	.sync_fs	= ext4_sync_fs,
1552 	.freeze_fs	= ext4_freeze,
1553 	.unfreeze_fs	= ext4_unfreeze,
1554 	.statfs		= ext4_statfs,
1555 	.show_options	= ext4_show_options,
1556 #ifdef CONFIG_QUOTA
1557 	.quota_read	= ext4_quota_read,
1558 	.quota_write	= ext4_quota_write,
1559 	.get_dquots	= ext4_get_dquots,
1560 #endif
1561 };
1562 
1563 static const struct export_operations ext4_export_ops = {
1564 	.fh_to_dentry = ext4_fh_to_dentry,
1565 	.fh_to_parent = ext4_fh_to_parent,
1566 	.get_parent = ext4_get_parent,
1567 	.commit_metadata = ext4_nfs_commit_metadata,
1568 };
1569 
1570 enum {
1571 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1572 	Opt_resgid, Opt_resuid, Opt_sb,
1573 	Opt_nouid32, Opt_debug, Opt_removed,
1574 	Opt_user_xattr, Opt_acl,
1575 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1576 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1577 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1578 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1579 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1580 	Opt_inlinecrypt,
1581 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1582 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1583 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1584 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1585 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1586 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1587 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1588 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1589 	Opt_dioread_nolock, Opt_dioread_lock,
1590 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1591 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1592 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1593 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1594 #ifdef CONFIG_EXT4_DEBUG
1595 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1596 #endif
1597 };
1598 
1599 static const struct constant_table ext4_param_errors[] = {
1600 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1601 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1602 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1603 	{}
1604 };
1605 
1606 static const struct constant_table ext4_param_data[] = {
1607 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1608 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1609 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1610 	{}
1611 };
1612 
1613 static const struct constant_table ext4_param_data_err[] = {
1614 	{"abort",	Opt_data_err_abort},
1615 	{"ignore",	Opt_data_err_ignore},
1616 	{}
1617 };
1618 
1619 static const struct constant_table ext4_param_jqfmt[] = {
1620 	{"vfsold",	QFMT_VFS_OLD},
1621 	{"vfsv0",	QFMT_VFS_V0},
1622 	{"vfsv1",	QFMT_VFS_V1},
1623 	{}
1624 };
1625 
1626 static const struct constant_table ext4_param_dax[] = {
1627 	{"always",	Opt_dax_always},
1628 	{"inode",	Opt_dax_inode},
1629 	{"never",	Opt_dax_never},
1630 	{}
1631 };
1632 
1633 /* String parameter that allows empty argument */
1634 #define fsparam_string_empty(NAME, OPT) \
1635 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1636 
1637 /*
1638  * Mount option specification
1639  * We don't use fsparam_flag_no because of the way we set the
1640  * options and the way we show them in _ext4_show_options(). To
1641  * keep the changes to a minimum, let's keep the negative options
1642  * separate for now.
1643  */
1644 static const struct fs_parameter_spec ext4_param_specs[] = {
1645 	fsparam_flag	("bsddf",		Opt_bsd_df),
1646 	fsparam_flag	("minixdf",		Opt_minix_df),
1647 	fsparam_flag	("grpid",		Opt_grpid),
1648 	fsparam_flag	("bsdgroups",		Opt_grpid),
1649 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1650 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1651 	fsparam_u32	("resgid",		Opt_resgid),
1652 	fsparam_u32	("resuid",		Opt_resuid),
1653 	fsparam_u32	("sb",			Opt_sb),
1654 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1655 	fsparam_flag	("nouid32",		Opt_nouid32),
1656 	fsparam_flag	("debug",		Opt_debug),
1657 	fsparam_flag	("oldalloc",		Opt_removed),
1658 	fsparam_flag	("orlov",		Opt_removed),
1659 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1660 	fsparam_flag	("acl",			Opt_acl),
1661 	fsparam_flag	("norecovery",		Opt_noload),
1662 	fsparam_flag	("noload",		Opt_noload),
1663 	fsparam_flag	("bh",			Opt_removed),
1664 	fsparam_flag	("nobh",		Opt_removed),
1665 	fsparam_u32	("commit",		Opt_commit),
1666 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1667 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1668 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1669 	fsparam_bdev	("journal_path",	Opt_journal_path),
1670 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1671 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1672 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1673 	fsparam_flag	("abort",		Opt_abort),
1674 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1675 	fsparam_enum	("data_err",		Opt_data_err,
1676 						ext4_param_data_err),
1677 	fsparam_string_empty
1678 			("usrjquota",		Opt_usrjquota),
1679 	fsparam_string_empty
1680 			("grpjquota",		Opt_grpjquota),
1681 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1682 	fsparam_flag	("grpquota",		Opt_grpquota),
1683 	fsparam_flag	("quota",		Opt_quota),
1684 	fsparam_flag	("noquota",		Opt_noquota),
1685 	fsparam_flag	("usrquota",		Opt_usrquota),
1686 	fsparam_flag	("prjquota",		Opt_prjquota),
1687 	fsparam_flag	("barrier",		Opt_barrier),
1688 	fsparam_u32	("barrier",		Opt_barrier),
1689 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1690 	fsparam_flag	("i_version",		Opt_removed),
1691 	fsparam_flag	("dax",			Opt_dax),
1692 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1693 	fsparam_u32	("stripe",		Opt_stripe),
1694 	fsparam_flag	("delalloc",		Opt_delalloc),
1695 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1696 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1697 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1698 	fsparam_u32	("debug_want_extra_isize",
1699 						Opt_debug_want_extra_isize),
1700 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1701 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1702 	fsparam_flag	("block_validity",	Opt_block_validity),
1703 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1704 	fsparam_u32	("inode_readahead_blks",
1705 						Opt_inode_readahead_blks),
1706 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1707 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1708 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1709 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1710 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1711 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1712 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1713 	fsparam_flag	("discard",		Opt_discard),
1714 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1715 	fsparam_u32	("init_itable",		Opt_init_itable),
1716 	fsparam_flag	("init_itable",		Opt_init_itable),
1717 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1718 #ifdef CONFIG_EXT4_DEBUG
1719 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1720 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1721 #endif
1722 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1723 	fsparam_flag	("test_dummy_encryption",
1724 						Opt_test_dummy_encryption),
1725 	fsparam_string	("test_dummy_encryption",
1726 						Opt_test_dummy_encryption),
1727 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1728 	fsparam_flag	("nombcache",		Opt_nombcache),
1729 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1730 	fsparam_flag	("prefetch_block_bitmaps",
1731 						Opt_removed),
1732 	fsparam_flag	("no_prefetch_block_bitmaps",
1733 						Opt_no_prefetch_block_bitmaps),
1734 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1735 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1736 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1737 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1738 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1739 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1740 	{}
1741 };
1742 
1743 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1744 
1745 #define MOPT_SET	0x0001
1746 #define MOPT_CLEAR	0x0002
1747 #define MOPT_NOSUPPORT	0x0004
1748 #define MOPT_EXPLICIT	0x0008
1749 #ifdef CONFIG_QUOTA
1750 #define MOPT_Q		0
1751 #define MOPT_QFMT	0x0010
1752 #else
1753 #define MOPT_Q		MOPT_NOSUPPORT
1754 #define MOPT_QFMT	MOPT_NOSUPPORT
1755 #endif
1756 #define MOPT_NO_EXT2	0x0020
1757 #define MOPT_NO_EXT3	0x0040
1758 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1759 #define MOPT_SKIP	0x0080
1760 #define	MOPT_2		0x0100
1761 
1762 static const struct mount_opts {
1763 	int	token;
1764 	int	mount_opt;
1765 	int	flags;
1766 } ext4_mount_opts[] = {
1767 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1768 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1769 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1770 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1771 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1772 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1773 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1774 	 MOPT_EXT4_ONLY | MOPT_SET},
1775 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1776 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1777 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1778 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1779 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1780 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1781 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1782 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1783 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1784 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1785 	{Opt_commit, 0, MOPT_NO_EXT2},
1786 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1787 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1788 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1789 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1790 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1791 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1792 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1793 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1794 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1795 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1796 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1797 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1798 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1799 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1800 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1801 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1802 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1803 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1804 	{Opt_data, 0, MOPT_NO_EXT2},
1805 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1806 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1807 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1808 #else
1809 	{Opt_acl, 0, MOPT_NOSUPPORT},
1810 #endif
1811 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1812 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1813 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1814 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1815 							MOPT_SET | MOPT_Q},
1816 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1817 							MOPT_SET | MOPT_Q},
1818 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1819 							MOPT_SET | MOPT_Q},
1820 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1821 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1822 							MOPT_CLEAR | MOPT_Q},
1823 	{Opt_usrjquota, 0, MOPT_Q},
1824 	{Opt_grpjquota, 0, MOPT_Q},
1825 	{Opt_jqfmt, 0, MOPT_QFMT},
1826 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1827 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1828 	 MOPT_SET},
1829 #ifdef CONFIG_EXT4_DEBUG
1830 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1831 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1832 #endif
1833 	{Opt_err, 0, 0}
1834 };
1835 
1836 #if IS_ENABLED(CONFIG_UNICODE)
1837 static const struct ext4_sb_encodings {
1838 	__u16 magic;
1839 	char *name;
1840 	unsigned int version;
1841 } ext4_sb_encoding_map[] = {
1842 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1843 };
1844 
1845 static const struct ext4_sb_encodings *
1846 ext4_sb_read_encoding(const struct ext4_super_block *es)
1847 {
1848 	__u16 magic = le16_to_cpu(es->s_encoding);
1849 	int i;
1850 
1851 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1852 		if (magic == ext4_sb_encoding_map[i].magic)
1853 			return &ext4_sb_encoding_map[i];
1854 
1855 	return NULL;
1856 }
1857 #endif
1858 
1859 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1860 #define EXT4_SPEC_JQFMT				(1 <<  1)
1861 #define EXT4_SPEC_DATAJ				(1 <<  2)
1862 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1863 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1864 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1865 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1866 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1867 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1868 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1869 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1870 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1871 #define EXT4_SPEC_s_stripe			(1 << 13)
1872 #define EXT4_SPEC_s_resuid			(1 << 14)
1873 #define EXT4_SPEC_s_resgid			(1 << 15)
1874 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1875 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1876 #define EXT4_SPEC_s_sb_block			(1 << 18)
1877 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1878 
1879 struct ext4_fs_context {
1880 	char		*s_qf_names[EXT4_MAXQUOTAS];
1881 	struct fscrypt_dummy_policy dummy_enc_policy;
1882 	int		s_jquota_fmt;	/* Format of quota to use */
1883 #ifdef CONFIG_EXT4_DEBUG
1884 	int s_fc_debug_max_replay;
1885 #endif
1886 	unsigned short	qname_spec;
1887 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1888 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1889 	unsigned long	journal_devnum;
1890 	unsigned long	s_commit_interval;
1891 	unsigned long	s_stripe;
1892 	unsigned int	s_inode_readahead_blks;
1893 	unsigned int	s_want_extra_isize;
1894 	unsigned int	s_li_wait_mult;
1895 	unsigned int	s_max_dir_size_kb;
1896 	unsigned int	journal_ioprio;
1897 	unsigned int	vals_s_mount_opt;
1898 	unsigned int	mask_s_mount_opt;
1899 	unsigned int	vals_s_mount_opt2;
1900 	unsigned int	mask_s_mount_opt2;
1901 	unsigned long	vals_s_mount_flags;
1902 	unsigned long	mask_s_mount_flags;
1903 	unsigned int	opt_flags;	/* MOPT flags */
1904 	unsigned int	spec;
1905 	u32		s_max_batch_time;
1906 	u32		s_min_batch_time;
1907 	kuid_t		s_resuid;
1908 	kgid_t		s_resgid;
1909 	ext4_fsblk_t	s_sb_block;
1910 };
1911 
1912 static void ext4_fc_free(struct fs_context *fc)
1913 {
1914 	struct ext4_fs_context *ctx = fc->fs_private;
1915 	int i;
1916 
1917 	if (!ctx)
1918 		return;
1919 
1920 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1921 		kfree(ctx->s_qf_names[i]);
1922 
1923 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1924 	kfree(ctx);
1925 }
1926 
1927 int ext4_init_fs_context(struct fs_context *fc)
1928 {
1929 	struct ext4_fs_context *ctx;
1930 
1931 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1932 	if (!ctx)
1933 		return -ENOMEM;
1934 
1935 	fc->fs_private = ctx;
1936 	fc->ops = &ext4_context_ops;
1937 
1938 	return 0;
1939 }
1940 
1941 #ifdef CONFIG_QUOTA
1942 /*
1943  * Note the name of the specified quota file.
1944  */
1945 static int note_qf_name(struct fs_context *fc, int qtype,
1946 		       struct fs_parameter *param)
1947 {
1948 	struct ext4_fs_context *ctx = fc->fs_private;
1949 	char *qname;
1950 
1951 	if (param->size < 1) {
1952 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
1953 		return -EINVAL;
1954 	}
1955 	if (strchr(param->string, '/')) {
1956 		ext4_msg(NULL, KERN_ERR,
1957 			 "quotafile must be on filesystem root");
1958 		return -EINVAL;
1959 	}
1960 	if (ctx->s_qf_names[qtype]) {
1961 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
1962 			ext4_msg(NULL, KERN_ERR,
1963 				 "%s quota file already specified",
1964 				 QTYPE2NAME(qtype));
1965 			return -EINVAL;
1966 		}
1967 		return 0;
1968 	}
1969 
1970 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
1971 	if (!qname) {
1972 		ext4_msg(NULL, KERN_ERR,
1973 			 "Not enough memory for storing quotafile name");
1974 		return -ENOMEM;
1975 	}
1976 	ctx->s_qf_names[qtype] = qname;
1977 	ctx->qname_spec |= 1 << qtype;
1978 	ctx->spec |= EXT4_SPEC_JQUOTA;
1979 	return 0;
1980 }
1981 
1982 /*
1983  * Clear the name of the specified quota file.
1984  */
1985 static int unnote_qf_name(struct fs_context *fc, int qtype)
1986 {
1987 	struct ext4_fs_context *ctx = fc->fs_private;
1988 
1989 	if (ctx->s_qf_names[qtype])
1990 		kfree(ctx->s_qf_names[qtype]);
1991 
1992 	ctx->s_qf_names[qtype] = NULL;
1993 	ctx->qname_spec |= 1 << qtype;
1994 	ctx->spec |= EXT4_SPEC_JQUOTA;
1995 	return 0;
1996 }
1997 #endif
1998 
1999 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2000 					    struct ext4_fs_context *ctx)
2001 {
2002 	int err;
2003 
2004 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2005 		ext4_msg(NULL, KERN_WARNING,
2006 			 "test_dummy_encryption option not supported");
2007 		return -EINVAL;
2008 	}
2009 	err = fscrypt_parse_test_dummy_encryption(param,
2010 						  &ctx->dummy_enc_policy);
2011 	if (err == -EINVAL) {
2012 		ext4_msg(NULL, KERN_WARNING,
2013 			 "Value of option \"%s\" is unrecognized", param->key);
2014 	} else if (err == -EEXIST) {
2015 		ext4_msg(NULL, KERN_WARNING,
2016 			 "Conflicting test_dummy_encryption options");
2017 		return -EINVAL;
2018 	}
2019 	return err;
2020 }
2021 
2022 #define EXT4_SET_CTX(name)						\
2023 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2024 				  unsigned long flag)			\
2025 {									\
2026 	ctx->mask_s_##name |= flag;					\
2027 	ctx->vals_s_##name |= flag;					\
2028 }
2029 
2030 #define EXT4_CLEAR_CTX(name)						\
2031 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2032 				    unsigned long flag)			\
2033 {									\
2034 	ctx->mask_s_##name |= flag;					\
2035 	ctx->vals_s_##name &= ~flag;					\
2036 }
2037 
2038 #define EXT4_TEST_CTX(name)						\
2039 static inline unsigned long						\
2040 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2041 {									\
2042 	return (ctx->vals_s_##name & flag);				\
2043 }
2044 
2045 EXT4_SET_CTX(flags); /* set only */
2046 EXT4_SET_CTX(mount_opt);
2047 EXT4_CLEAR_CTX(mount_opt);
2048 EXT4_TEST_CTX(mount_opt);
2049 EXT4_SET_CTX(mount_opt2);
2050 EXT4_CLEAR_CTX(mount_opt2);
2051 EXT4_TEST_CTX(mount_opt2);
2052 
2053 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2054 {
2055 	set_bit(bit, &ctx->mask_s_mount_flags);
2056 	set_bit(bit, &ctx->vals_s_mount_flags);
2057 }
2058 
2059 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2060 {
2061 	struct ext4_fs_context *ctx = fc->fs_private;
2062 	struct fs_parse_result result;
2063 	const struct mount_opts *m;
2064 	int is_remount;
2065 	kuid_t uid;
2066 	kgid_t gid;
2067 	int token;
2068 
2069 	token = fs_parse(fc, ext4_param_specs, param, &result);
2070 	if (token < 0)
2071 		return token;
2072 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2073 
2074 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2075 		if (token == m->token)
2076 			break;
2077 
2078 	ctx->opt_flags |= m->flags;
2079 
2080 	if (m->flags & MOPT_EXPLICIT) {
2081 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2082 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2083 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2084 			ctx_set_mount_opt2(ctx,
2085 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2086 		} else
2087 			return -EINVAL;
2088 	}
2089 
2090 	if (m->flags & MOPT_NOSUPPORT) {
2091 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2092 			 param->key);
2093 		return 0;
2094 	}
2095 
2096 	switch (token) {
2097 #ifdef CONFIG_QUOTA
2098 	case Opt_usrjquota:
2099 		if (!*param->string)
2100 			return unnote_qf_name(fc, USRQUOTA);
2101 		else
2102 			return note_qf_name(fc, USRQUOTA, param);
2103 	case Opt_grpjquota:
2104 		if (!*param->string)
2105 			return unnote_qf_name(fc, GRPQUOTA);
2106 		else
2107 			return note_qf_name(fc, GRPQUOTA, param);
2108 #endif
2109 	case Opt_sb:
2110 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2111 			ext4_msg(NULL, KERN_WARNING,
2112 				 "Ignoring %s option on remount", param->key);
2113 		} else {
2114 			ctx->s_sb_block = result.uint_32;
2115 			ctx->spec |= EXT4_SPEC_s_sb_block;
2116 		}
2117 		return 0;
2118 	case Opt_removed:
2119 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2120 			 param->key);
2121 		return 0;
2122 	case Opt_abort:
2123 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2124 		return 0;
2125 	case Opt_inlinecrypt:
2126 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2127 		ctx_set_flags(ctx, SB_INLINECRYPT);
2128 #else
2129 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2130 #endif
2131 		return 0;
2132 	case Opt_errors:
2133 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2134 		ctx_set_mount_opt(ctx, result.uint_32);
2135 		return 0;
2136 #ifdef CONFIG_QUOTA
2137 	case Opt_jqfmt:
2138 		ctx->s_jquota_fmt = result.uint_32;
2139 		ctx->spec |= EXT4_SPEC_JQFMT;
2140 		return 0;
2141 #endif
2142 	case Opt_data:
2143 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2144 		ctx_set_mount_opt(ctx, result.uint_32);
2145 		ctx->spec |= EXT4_SPEC_DATAJ;
2146 		return 0;
2147 	case Opt_commit:
2148 		if (result.uint_32 == 0)
2149 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2150 		else if (result.uint_32 > INT_MAX / HZ) {
2151 			ext4_msg(NULL, KERN_ERR,
2152 				 "Invalid commit interval %d, "
2153 				 "must be smaller than %d",
2154 				 result.uint_32, INT_MAX / HZ);
2155 			return -EINVAL;
2156 		}
2157 		ctx->s_commit_interval = HZ * result.uint_32;
2158 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2159 		return 0;
2160 	case Opt_debug_want_extra_isize:
2161 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2162 			ext4_msg(NULL, KERN_ERR,
2163 				 "Invalid want_extra_isize %d", result.uint_32);
2164 			return -EINVAL;
2165 		}
2166 		ctx->s_want_extra_isize = result.uint_32;
2167 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2168 		return 0;
2169 	case Opt_max_batch_time:
2170 		ctx->s_max_batch_time = result.uint_32;
2171 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2172 		return 0;
2173 	case Opt_min_batch_time:
2174 		ctx->s_min_batch_time = result.uint_32;
2175 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2176 		return 0;
2177 	case Opt_inode_readahead_blks:
2178 		if (result.uint_32 &&
2179 		    (result.uint_32 > (1 << 30) ||
2180 		     !is_power_of_2(result.uint_32))) {
2181 			ext4_msg(NULL, KERN_ERR,
2182 				 "EXT4-fs: inode_readahead_blks must be "
2183 				 "0 or a power of 2 smaller than 2^31");
2184 			return -EINVAL;
2185 		}
2186 		ctx->s_inode_readahead_blks = result.uint_32;
2187 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2188 		return 0;
2189 	case Opt_init_itable:
2190 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2191 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2192 		if (param->type == fs_value_is_string)
2193 			ctx->s_li_wait_mult = result.uint_32;
2194 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2195 		return 0;
2196 	case Opt_max_dir_size_kb:
2197 		ctx->s_max_dir_size_kb = result.uint_32;
2198 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2199 		return 0;
2200 #ifdef CONFIG_EXT4_DEBUG
2201 	case Opt_fc_debug_max_replay:
2202 		ctx->s_fc_debug_max_replay = result.uint_32;
2203 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2204 		return 0;
2205 #endif
2206 	case Opt_stripe:
2207 		ctx->s_stripe = result.uint_32;
2208 		ctx->spec |= EXT4_SPEC_s_stripe;
2209 		return 0;
2210 	case Opt_resuid:
2211 		uid = make_kuid(current_user_ns(), result.uint_32);
2212 		if (!uid_valid(uid)) {
2213 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2214 				 result.uint_32);
2215 			return -EINVAL;
2216 		}
2217 		ctx->s_resuid = uid;
2218 		ctx->spec |= EXT4_SPEC_s_resuid;
2219 		return 0;
2220 	case Opt_resgid:
2221 		gid = make_kgid(current_user_ns(), result.uint_32);
2222 		if (!gid_valid(gid)) {
2223 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2224 				 result.uint_32);
2225 			return -EINVAL;
2226 		}
2227 		ctx->s_resgid = gid;
2228 		ctx->spec |= EXT4_SPEC_s_resgid;
2229 		return 0;
2230 	case Opt_journal_dev:
2231 		if (is_remount) {
2232 			ext4_msg(NULL, KERN_ERR,
2233 				 "Cannot specify journal on remount");
2234 			return -EINVAL;
2235 		}
2236 		ctx->journal_devnum = result.uint_32;
2237 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2238 		return 0;
2239 	case Opt_journal_path:
2240 	{
2241 		struct inode *journal_inode;
2242 		struct path path;
2243 		int error;
2244 
2245 		if (is_remount) {
2246 			ext4_msg(NULL, KERN_ERR,
2247 				 "Cannot specify journal on remount");
2248 			return -EINVAL;
2249 		}
2250 
2251 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2252 		if (error) {
2253 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2254 				 "journal device path");
2255 			return -EINVAL;
2256 		}
2257 
2258 		journal_inode = d_inode(path.dentry);
2259 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2260 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2261 		path_put(&path);
2262 		return 0;
2263 	}
2264 	case Opt_journal_ioprio:
2265 		if (result.uint_32 > 7) {
2266 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2267 				 " (must be 0-7)");
2268 			return -EINVAL;
2269 		}
2270 		ctx->journal_ioprio =
2271 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2272 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2273 		return 0;
2274 	case Opt_test_dummy_encryption:
2275 		return ext4_parse_test_dummy_encryption(param, ctx);
2276 	case Opt_dax:
2277 	case Opt_dax_type:
2278 #ifdef CONFIG_FS_DAX
2279 	{
2280 		int type = (token == Opt_dax) ?
2281 			   Opt_dax : result.uint_32;
2282 
2283 		switch (type) {
2284 		case Opt_dax:
2285 		case Opt_dax_always:
2286 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2287 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2288 			break;
2289 		case Opt_dax_never:
2290 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2291 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2292 			break;
2293 		case Opt_dax_inode:
2294 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2295 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2296 			/* Strictly for printing options */
2297 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2298 			break;
2299 		}
2300 		return 0;
2301 	}
2302 #else
2303 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2304 		return -EINVAL;
2305 #endif
2306 	case Opt_data_err:
2307 		if (result.uint_32 == Opt_data_err_abort)
2308 			ctx_set_mount_opt(ctx, m->mount_opt);
2309 		else if (result.uint_32 == Opt_data_err_ignore)
2310 			ctx_clear_mount_opt(ctx, m->mount_opt);
2311 		return 0;
2312 	case Opt_mb_optimize_scan:
2313 		if (result.int_32 == 1) {
2314 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2315 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2316 		} else if (result.int_32 == 0) {
2317 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2318 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2319 		} else {
2320 			ext4_msg(NULL, KERN_WARNING,
2321 				 "mb_optimize_scan should be set to 0 or 1.");
2322 			return -EINVAL;
2323 		}
2324 		return 0;
2325 	}
2326 
2327 	/*
2328 	 * At this point we should only be getting options requiring MOPT_SET,
2329 	 * or MOPT_CLEAR. Anything else is a bug
2330 	 */
2331 	if (m->token == Opt_err) {
2332 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2333 			 param->key);
2334 		WARN_ON(1);
2335 		return -EINVAL;
2336 	}
2337 
2338 	else {
2339 		unsigned int set = 0;
2340 
2341 		if ((param->type == fs_value_is_flag) ||
2342 		    result.uint_32 > 0)
2343 			set = 1;
2344 
2345 		if (m->flags & MOPT_CLEAR)
2346 			set = !set;
2347 		else if (unlikely(!(m->flags & MOPT_SET))) {
2348 			ext4_msg(NULL, KERN_WARNING,
2349 				 "buggy handling of option %s",
2350 				 param->key);
2351 			WARN_ON(1);
2352 			return -EINVAL;
2353 		}
2354 		if (m->flags & MOPT_2) {
2355 			if (set != 0)
2356 				ctx_set_mount_opt2(ctx, m->mount_opt);
2357 			else
2358 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2359 		} else {
2360 			if (set != 0)
2361 				ctx_set_mount_opt(ctx, m->mount_opt);
2362 			else
2363 				ctx_clear_mount_opt(ctx, m->mount_opt);
2364 		}
2365 	}
2366 
2367 	return 0;
2368 }
2369 
2370 static int parse_options(struct fs_context *fc, char *options)
2371 {
2372 	struct fs_parameter param;
2373 	int ret;
2374 	char *key;
2375 
2376 	if (!options)
2377 		return 0;
2378 
2379 	while ((key = strsep(&options, ",")) != NULL) {
2380 		if (*key) {
2381 			size_t v_len = 0;
2382 			char *value = strchr(key, '=');
2383 
2384 			param.type = fs_value_is_flag;
2385 			param.string = NULL;
2386 
2387 			if (value) {
2388 				if (value == key)
2389 					continue;
2390 
2391 				*value++ = 0;
2392 				v_len = strlen(value);
2393 				param.string = kmemdup_nul(value, v_len,
2394 							   GFP_KERNEL);
2395 				if (!param.string)
2396 					return -ENOMEM;
2397 				param.type = fs_value_is_string;
2398 			}
2399 
2400 			param.key = key;
2401 			param.size = v_len;
2402 
2403 			ret = ext4_parse_param(fc, &param);
2404 			if (param.string)
2405 				kfree(param.string);
2406 			if (ret < 0)
2407 				return ret;
2408 		}
2409 	}
2410 
2411 	ret = ext4_validate_options(fc);
2412 	if (ret < 0)
2413 		return ret;
2414 
2415 	return 0;
2416 }
2417 
2418 static int parse_apply_sb_mount_options(struct super_block *sb,
2419 					struct ext4_fs_context *m_ctx)
2420 {
2421 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2422 	char *s_mount_opts = NULL;
2423 	struct ext4_fs_context *s_ctx = NULL;
2424 	struct fs_context *fc = NULL;
2425 	int ret = -ENOMEM;
2426 
2427 	if (!sbi->s_es->s_mount_opts[0])
2428 		return 0;
2429 
2430 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2431 				sizeof(sbi->s_es->s_mount_opts),
2432 				GFP_KERNEL);
2433 	if (!s_mount_opts)
2434 		return ret;
2435 
2436 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2437 	if (!fc)
2438 		goto out_free;
2439 
2440 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2441 	if (!s_ctx)
2442 		goto out_free;
2443 
2444 	fc->fs_private = s_ctx;
2445 	fc->s_fs_info = sbi;
2446 
2447 	ret = parse_options(fc, s_mount_opts);
2448 	if (ret < 0)
2449 		goto parse_failed;
2450 
2451 	ret = ext4_check_opt_consistency(fc, sb);
2452 	if (ret < 0) {
2453 parse_failed:
2454 		ext4_msg(sb, KERN_WARNING,
2455 			 "failed to parse options in superblock: %s",
2456 			 s_mount_opts);
2457 		ret = 0;
2458 		goto out_free;
2459 	}
2460 
2461 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2462 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2463 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2464 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2465 
2466 	ext4_apply_options(fc, sb);
2467 	ret = 0;
2468 
2469 out_free:
2470 	if (fc) {
2471 		ext4_fc_free(fc);
2472 		kfree(fc);
2473 	}
2474 	kfree(s_mount_opts);
2475 	return ret;
2476 }
2477 
2478 static void ext4_apply_quota_options(struct fs_context *fc,
2479 				     struct super_block *sb)
2480 {
2481 #ifdef CONFIG_QUOTA
2482 	bool quota_feature = ext4_has_feature_quota(sb);
2483 	struct ext4_fs_context *ctx = fc->fs_private;
2484 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2485 	char *qname;
2486 	int i;
2487 
2488 	if (quota_feature)
2489 		return;
2490 
2491 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2492 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2493 			if (!(ctx->qname_spec & (1 << i)))
2494 				continue;
2495 
2496 			qname = ctx->s_qf_names[i]; /* May be NULL */
2497 			if (qname)
2498 				set_opt(sb, QUOTA);
2499 			ctx->s_qf_names[i] = NULL;
2500 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2501 						lockdep_is_held(&sb->s_umount));
2502 			if (qname)
2503 				kfree_rcu(qname);
2504 		}
2505 	}
2506 
2507 	if (ctx->spec & EXT4_SPEC_JQFMT)
2508 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2509 #endif
2510 }
2511 
2512 /*
2513  * Check quota settings consistency.
2514  */
2515 static int ext4_check_quota_consistency(struct fs_context *fc,
2516 					struct super_block *sb)
2517 {
2518 #ifdef CONFIG_QUOTA
2519 	struct ext4_fs_context *ctx = fc->fs_private;
2520 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2521 	bool quota_feature = ext4_has_feature_quota(sb);
2522 	bool quota_loaded = sb_any_quota_loaded(sb);
2523 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2524 	int quota_flags, i;
2525 
2526 	/*
2527 	 * We do the test below only for project quotas. 'usrquota' and
2528 	 * 'grpquota' mount options are allowed even without quota feature
2529 	 * to support legacy quotas in quota files.
2530 	 */
2531 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2532 	    !ext4_has_feature_project(sb)) {
2533 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2534 			 "Cannot enable project quota enforcement.");
2535 		return -EINVAL;
2536 	}
2537 
2538 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2539 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2540 	if (quota_loaded &&
2541 	    ctx->mask_s_mount_opt & quota_flags &&
2542 	    !ctx_test_mount_opt(ctx, quota_flags))
2543 		goto err_quota_change;
2544 
2545 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2546 
2547 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2548 			if (!(ctx->qname_spec & (1 << i)))
2549 				continue;
2550 
2551 			if (quota_loaded &&
2552 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2553 				goto err_jquota_change;
2554 
2555 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2556 			    strcmp(get_qf_name(sb, sbi, i),
2557 				   ctx->s_qf_names[i]) != 0)
2558 				goto err_jquota_specified;
2559 		}
2560 
2561 		if (quota_feature) {
2562 			ext4_msg(NULL, KERN_INFO,
2563 				 "Journaled quota options ignored when "
2564 				 "QUOTA feature is enabled");
2565 			return 0;
2566 		}
2567 	}
2568 
2569 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2570 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2571 			goto err_jquota_change;
2572 		if (quota_feature) {
2573 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2574 				 "ignored when QUOTA feature is enabled");
2575 			return 0;
2576 		}
2577 	}
2578 
2579 	/* Make sure we don't mix old and new quota format */
2580 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2581 		       ctx->s_qf_names[USRQUOTA]);
2582 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2583 		       ctx->s_qf_names[GRPQUOTA]);
2584 
2585 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2586 		    test_opt(sb, USRQUOTA));
2587 
2588 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2589 		    test_opt(sb, GRPQUOTA));
2590 
2591 	if (usr_qf_name) {
2592 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2593 		usrquota = false;
2594 	}
2595 	if (grp_qf_name) {
2596 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2597 		grpquota = false;
2598 	}
2599 
2600 	if (usr_qf_name || grp_qf_name) {
2601 		if (usrquota || grpquota) {
2602 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2603 				 "format mixing");
2604 			return -EINVAL;
2605 		}
2606 
2607 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2608 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2609 				 "not specified");
2610 			return -EINVAL;
2611 		}
2612 	}
2613 
2614 	return 0;
2615 
2616 err_quota_change:
2617 	ext4_msg(NULL, KERN_ERR,
2618 		 "Cannot change quota options when quota turned on");
2619 	return -EINVAL;
2620 err_jquota_change:
2621 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2622 		 "options when quota turned on");
2623 	return -EINVAL;
2624 err_jquota_specified:
2625 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2626 		 QTYPE2NAME(i));
2627 	return -EINVAL;
2628 #else
2629 	return 0;
2630 #endif
2631 }
2632 
2633 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2634 					    struct super_block *sb)
2635 {
2636 	const struct ext4_fs_context *ctx = fc->fs_private;
2637 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2638 
2639 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2640 		return 0;
2641 
2642 	if (!ext4_has_feature_encrypt(sb)) {
2643 		ext4_msg(NULL, KERN_WARNING,
2644 			 "test_dummy_encryption requires encrypt feature");
2645 		return -EINVAL;
2646 	}
2647 	/*
2648 	 * This mount option is just for testing, and it's not worthwhile to
2649 	 * implement the extra complexity (e.g. RCU protection) that would be
2650 	 * needed to allow it to be set or changed during remount.  We do allow
2651 	 * it to be specified during remount, but only if there is no change.
2652 	 */
2653 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2654 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2655 						 &ctx->dummy_enc_policy))
2656 			return 0;
2657 		ext4_msg(NULL, KERN_WARNING,
2658 			 "Can't set or change test_dummy_encryption on remount");
2659 		return -EINVAL;
2660 	}
2661 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2662 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2663 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2664 						 &ctx->dummy_enc_policy))
2665 			return 0;
2666 		ext4_msg(NULL, KERN_WARNING,
2667 			 "Conflicting test_dummy_encryption options");
2668 		return -EINVAL;
2669 	}
2670 	return 0;
2671 }
2672 
2673 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2674 					     struct super_block *sb)
2675 {
2676 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2677 	    /* if already set, it was already verified to be the same */
2678 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2679 		return;
2680 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2681 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2682 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2683 }
2684 
2685 static int ext4_check_opt_consistency(struct fs_context *fc,
2686 				      struct super_block *sb)
2687 {
2688 	struct ext4_fs_context *ctx = fc->fs_private;
2689 	struct ext4_sb_info *sbi = fc->s_fs_info;
2690 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2691 	int err;
2692 
2693 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2694 		ext4_msg(NULL, KERN_ERR,
2695 			 "Mount option(s) incompatible with ext2");
2696 		return -EINVAL;
2697 	}
2698 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2699 		ext4_msg(NULL, KERN_ERR,
2700 			 "Mount option(s) incompatible with ext3");
2701 		return -EINVAL;
2702 	}
2703 
2704 	if (ctx->s_want_extra_isize >
2705 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2706 		ext4_msg(NULL, KERN_ERR,
2707 			 "Invalid want_extra_isize %d",
2708 			 ctx->s_want_extra_isize);
2709 		return -EINVAL;
2710 	}
2711 
2712 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2713 		int blocksize =
2714 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2715 		if (blocksize < PAGE_SIZE)
2716 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2717 				 "experimental mount option 'dioread_nolock' "
2718 				 "for blocksize < PAGE_SIZE");
2719 	}
2720 
2721 	err = ext4_check_test_dummy_encryption(fc, sb);
2722 	if (err)
2723 		return err;
2724 
2725 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2726 		if (!sbi->s_journal) {
2727 			ext4_msg(NULL, KERN_WARNING,
2728 				 "Remounting file system with no journal "
2729 				 "so ignoring journalled data option");
2730 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2731 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2732 			   test_opt(sb, DATA_FLAGS)) {
2733 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2734 				 "on remount");
2735 			return -EINVAL;
2736 		}
2737 	}
2738 
2739 	if (is_remount) {
2740 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2741 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2742 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2743 				 "both data=journal and dax");
2744 			return -EINVAL;
2745 		}
2746 
2747 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2748 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2749 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2750 fail_dax_change_remount:
2751 			ext4_msg(NULL, KERN_ERR, "can't change "
2752 				 "dax mount option while remounting");
2753 			return -EINVAL;
2754 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2755 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2756 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2757 			goto fail_dax_change_remount;
2758 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2759 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2760 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2761 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2762 			goto fail_dax_change_remount;
2763 		}
2764 	}
2765 
2766 	return ext4_check_quota_consistency(fc, sb);
2767 }
2768 
2769 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2770 {
2771 	struct ext4_fs_context *ctx = fc->fs_private;
2772 	struct ext4_sb_info *sbi = fc->s_fs_info;
2773 
2774 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2775 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2776 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2777 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2778 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2779 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2780 	sb->s_flags &= ~ctx->mask_s_flags;
2781 	sb->s_flags |= ctx->vals_s_flags;
2782 
2783 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2784 	APPLY(s_commit_interval);
2785 	APPLY(s_stripe);
2786 	APPLY(s_max_batch_time);
2787 	APPLY(s_min_batch_time);
2788 	APPLY(s_want_extra_isize);
2789 	APPLY(s_inode_readahead_blks);
2790 	APPLY(s_max_dir_size_kb);
2791 	APPLY(s_li_wait_mult);
2792 	APPLY(s_resgid);
2793 	APPLY(s_resuid);
2794 
2795 #ifdef CONFIG_EXT4_DEBUG
2796 	APPLY(s_fc_debug_max_replay);
2797 #endif
2798 
2799 	ext4_apply_quota_options(fc, sb);
2800 	ext4_apply_test_dummy_encryption(ctx, sb);
2801 }
2802 
2803 
2804 static int ext4_validate_options(struct fs_context *fc)
2805 {
2806 #ifdef CONFIG_QUOTA
2807 	struct ext4_fs_context *ctx = fc->fs_private;
2808 	char *usr_qf_name, *grp_qf_name;
2809 
2810 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2811 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2812 
2813 	if (usr_qf_name || grp_qf_name) {
2814 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2815 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2816 
2817 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2818 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2819 
2820 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2821 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2822 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2823 				 "format mixing");
2824 			return -EINVAL;
2825 		}
2826 	}
2827 #endif
2828 	return 1;
2829 }
2830 
2831 static inline void ext4_show_quota_options(struct seq_file *seq,
2832 					   struct super_block *sb)
2833 {
2834 #if defined(CONFIG_QUOTA)
2835 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2836 	char *usr_qf_name, *grp_qf_name;
2837 
2838 	if (sbi->s_jquota_fmt) {
2839 		char *fmtname = "";
2840 
2841 		switch (sbi->s_jquota_fmt) {
2842 		case QFMT_VFS_OLD:
2843 			fmtname = "vfsold";
2844 			break;
2845 		case QFMT_VFS_V0:
2846 			fmtname = "vfsv0";
2847 			break;
2848 		case QFMT_VFS_V1:
2849 			fmtname = "vfsv1";
2850 			break;
2851 		}
2852 		seq_printf(seq, ",jqfmt=%s", fmtname);
2853 	}
2854 
2855 	rcu_read_lock();
2856 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2857 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2858 	if (usr_qf_name)
2859 		seq_show_option(seq, "usrjquota", usr_qf_name);
2860 	if (grp_qf_name)
2861 		seq_show_option(seq, "grpjquota", grp_qf_name);
2862 	rcu_read_unlock();
2863 #endif
2864 }
2865 
2866 static const char *token2str(int token)
2867 {
2868 	const struct fs_parameter_spec *spec;
2869 
2870 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2871 		if (spec->opt == token && !spec->type)
2872 			break;
2873 	return spec->name;
2874 }
2875 
2876 /*
2877  * Show an option if
2878  *  - it's set to a non-default value OR
2879  *  - if the per-sb default is different from the global default
2880  */
2881 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2882 			      int nodefs)
2883 {
2884 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2885 	struct ext4_super_block *es = sbi->s_es;
2886 	int def_errors;
2887 	const struct mount_opts *m;
2888 	char sep = nodefs ? '\n' : ',';
2889 
2890 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2891 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2892 
2893 	if (sbi->s_sb_block != 1)
2894 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2895 
2896 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2897 		int want_set = m->flags & MOPT_SET;
2898 		int opt_2 = m->flags & MOPT_2;
2899 		unsigned int mount_opt, def_mount_opt;
2900 
2901 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2902 		    m->flags & MOPT_SKIP)
2903 			continue;
2904 
2905 		if (opt_2) {
2906 			mount_opt = sbi->s_mount_opt2;
2907 			def_mount_opt = sbi->s_def_mount_opt2;
2908 		} else {
2909 			mount_opt = sbi->s_mount_opt;
2910 			def_mount_opt = sbi->s_def_mount_opt;
2911 		}
2912 		/* skip if same as the default */
2913 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2914 			continue;
2915 		/* select Opt_noFoo vs Opt_Foo */
2916 		if ((want_set &&
2917 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2918 		    (!want_set && (mount_opt & m->mount_opt)))
2919 			continue;
2920 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2921 	}
2922 
2923 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2924 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2925 		SEQ_OPTS_PRINT("resuid=%u",
2926 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2927 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2928 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2929 		SEQ_OPTS_PRINT("resgid=%u",
2930 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2931 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2932 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2933 		SEQ_OPTS_PUTS("errors=remount-ro");
2934 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2935 		SEQ_OPTS_PUTS("errors=continue");
2936 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2937 		SEQ_OPTS_PUTS("errors=panic");
2938 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2939 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2940 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2941 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2942 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2943 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2944 	if (nodefs || sbi->s_stripe)
2945 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2946 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2947 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
2948 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2949 			SEQ_OPTS_PUTS("data=journal");
2950 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2951 			SEQ_OPTS_PUTS("data=ordered");
2952 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2953 			SEQ_OPTS_PUTS("data=writeback");
2954 	}
2955 	if (nodefs ||
2956 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2957 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2958 			       sbi->s_inode_readahead_blks);
2959 
2960 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2961 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2962 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2963 	if (nodefs || sbi->s_max_dir_size_kb)
2964 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2965 	if (test_opt(sb, DATA_ERR_ABORT))
2966 		SEQ_OPTS_PUTS("data_err=abort");
2967 
2968 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2969 
2970 	if (sb->s_flags & SB_INLINECRYPT)
2971 		SEQ_OPTS_PUTS("inlinecrypt");
2972 
2973 	if (test_opt(sb, DAX_ALWAYS)) {
2974 		if (IS_EXT2_SB(sb))
2975 			SEQ_OPTS_PUTS("dax");
2976 		else
2977 			SEQ_OPTS_PUTS("dax=always");
2978 	} else if (test_opt2(sb, DAX_NEVER)) {
2979 		SEQ_OPTS_PUTS("dax=never");
2980 	} else if (test_opt2(sb, DAX_INODE)) {
2981 		SEQ_OPTS_PUTS("dax=inode");
2982 	}
2983 
2984 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
2985 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
2986 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
2987 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
2988 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
2989 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
2990 	}
2991 
2992 	ext4_show_quota_options(seq, sb);
2993 	return 0;
2994 }
2995 
2996 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2997 {
2998 	return _ext4_show_options(seq, root->d_sb, 0);
2999 }
3000 
3001 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3002 {
3003 	struct super_block *sb = seq->private;
3004 	int rc;
3005 
3006 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3007 	rc = _ext4_show_options(seq, sb, 1);
3008 	seq_puts(seq, "\n");
3009 	return rc;
3010 }
3011 
3012 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3013 			    int read_only)
3014 {
3015 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3016 	int err = 0;
3017 
3018 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3019 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3020 			 "forcing read-only mode");
3021 		err = -EROFS;
3022 		goto done;
3023 	}
3024 	if (read_only)
3025 		goto done;
3026 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3027 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3028 			 "running e2fsck is recommended");
3029 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3030 		ext4_msg(sb, KERN_WARNING,
3031 			 "warning: mounting fs with errors, "
3032 			 "running e2fsck is recommended");
3033 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3034 		 le16_to_cpu(es->s_mnt_count) >=
3035 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3036 		ext4_msg(sb, KERN_WARNING,
3037 			 "warning: maximal mount count reached, "
3038 			 "running e2fsck is recommended");
3039 	else if (le32_to_cpu(es->s_checkinterval) &&
3040 		 (ext4_get_tstamp(es, s_lastcheck) +
3041 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3042 		ext4_msg(sb, KERN_WARNING,
3043 			 "warning: checktime reached, "
3044 			 "running e2fsck is recommended");
3045 	if (!sbi->s_journal)
3046 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3047 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3048 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3049 	le16_add_cpu(&es->s_mnt_count, 1);
3050 	ext4_update_tstamp(es, s_mtime);
3051 	if (sbi->s_journal) {
3052 		ext4_set_feature_journal_needs_recovery(sb);
3053 		if (ext4_has_feature_orphan_file(sb))
3054 			ext4_set_feature_orphan_present(sb);
3055 	}
3056 
3057 	err = ext4_commit_super(sb);
3058 done:
3059 	if (test_opt(sb, DEBUG))
3060 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3061 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3062 			sb->s_blocksize,
3063 			sbi->s_groups_count,
3064 			EXT4_BLOCKS_PER_GROUP(sb),
3065 			EXT4_INODES_PER_GROUP(sb),
3066 			sbi->s_mount_opt, sbi->s_mount_opt2);
3067 	return err;
3068 }
3069 
3070 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3071 {
3072 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3073 	struct flex_groups **old_groups, **new_groups;
3074 	int size, i, j;
3075 
3076 	if (!sbi->s_log_groups_per_flex)
3077 		return 0;
3078 
3079 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3080 	if (size <= sbi->s_flex_groups_allocated)
3081 		return 0;
3082 
3083 	new_groups = kvzalloc(roundup_pow_of_two(size *
3084 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3085 	if (!new_groups) {
3086 		ext4_msg(sb, KERN_ERR,
3087 			 "not enough memory for %d flex group pointers", size);
3088 		return -ENOMEM;
3089 	}
3090 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3091 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3092 					 sizeof(struct flex_groups)),
3093 					 GFP_KERNEL);
3094 		if (!new_groups[i]) {
3095 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3096 				kvfree(new_groups[j]);
3097 			kvfree(new_groups);
3098 			ext4_msg(sb, KERN_ERR,
3099 				 "not enough memory for %d flex groups", size);
3100 			return -ENOMEM;
3101 		}
3102 	}
3103 	rcu_read_lock();
3104 	old_groups = rcu_dereference(sbi->s_flex_groups);
3105 	if (old_groups)
3106 		memcpy(new_groups, old_groups,
3107 		       (sbi->s_flex_groups_allocated *
3108 			sizeof(struct flex_groups *)));
3109 	rcu_read_unlock();
3110 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3111 	sbi->s_flex_groups_allocated = size;
3112 	if (old_groups)
3113 		ext4_kvfree_array_rcu(old_groups);
3114 	return 0;
3115 }
3116 
3117 static int ext4_fill_flex_info(struct super_block *sb)
3118 {
3119 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3120 	struct ext4_group_desc *gdp = NULL;
3121 	struct flex_groups *fg;
3122 	ext4_group_t flex_group;
3123 	int i, err;
3124 
3125 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3126 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3127 		sbi->s_log_groups_per_flex = 0;
3128 		return 1;
3129 	}
3130 
3131 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3132 	if (err)
3133 		goto failed;
3134 
3135 	for (i = 0; i < sbi->s_groups_count; i++) {
3136 		gdp = ext4_get_group_desc(sb, i, NULL);
3137 
3138 		flex_group = ext4_flex_group(sbi, i);
3139 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3140 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3141 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3142 			     &fg->free_clusters);
3143 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3144 	}
3145 
3146 	return 1;
3147 failed:
3148 	return 0;
3149 }
3150 
3151 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3152 				   struct ext4_group_desc *gdp)
3153 {
3154 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3155 	__u16 crc = 0;
3156 	__le32 le_group = cpu_to_le32(block_group);
3157 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3158 
3159 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3160 		/* Use new metadata_csum algorithm */
3161 		__u32 csum32;
3162 		__u16 dummy_csum = 0;
3163 
3164 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3165 				     sizeof(le_group));
3166 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3167 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3168 				     sizeof(dummy_csum));
3169 		offset += sizeof(dummy_csum);
3170 		if (offset < sbi->s_desc_size)
3171 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3172 					     sbi->s_desc_size - offset);
3173 
3174 		crc = csum32 & 0xFFFF;
3175 		goto out;
3176 	}
3177 
3178 	/* old crc16 code */
3179 	if (!ext4_has_feature_gdt_csum(sb))
3180 		return 0;
3181 
3182 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3183 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3184 	crc = crc16(crc, (__u8 *)gdp, offset);
3185 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3186 	/* for checksum of struct ext4_group_desc do the rest...*/
3187 	if (ext4_has_feature_64bit(sb) &&
3188 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3189 		crc = crc16(crc, (__u8 *)gdp + offset,
3190 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3191 				offset);
3192 
3193 out:
3194 	return cpu_to_le16(crc);
3195 }
3196 
3197 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3198 				struct ext4_group_desc *gdp)
3199 {
3200 	if (ext4_has_group_desc_csum(sb) &&
3201 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3202 		return 0;
3203 
3204 	return 1;
3205 }
3206 
3207 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3208 			      struct ext4_group_desc *gdp)
3209 {
3210 	if (!ext4_has_group_desc_csum(sb))
3211 		return;
3212 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3213 }
3214 
3215 /* Called at mount-time, super-block is locked */
3216 static int ext4_check_descriptors(struct super_block *sb,
3217 				  ext4_fsblk_t sb_block,
3218 				  ext4_group_t *first_not_zeroed)
3219 {
3220 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3221 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3222 	ext4_fsblk_t last_block;
3223 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3224 	ext4_fsblk_t block_bitmap;
3225 	ext4_fsblk_t inode_bitmap;
3226 	ext4_fsblk_t inode_table;
3227 	int flexbg_flag = 0;
3228 	ext4_group_t i, grp = sbi->s_groups_count;
3229 
3230 	if (ext4_has_feature_flex_bg(sb))
3231 		flexbg_flag = 1;
3232 
3233 	ext4_debug("Checking group descriptors");
3234 
3235 	for (i = 0; i < sbi->s_groups_count; i++) {
3236 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3237 
3238 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3239 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3240 		else
3241 			last_block = first_block +
3242 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3243 
3244 		if ((grp == sbi->s_groups_count) &&
3245 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3246 			grp = i;
3247 
3248 		block_bitmap = ext4_block_bitmap(sb, gdp);
3249 		if (block_bitmap == sb_block) {
3250 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3251 				 "Block bitmap for group %u overlaps "
3252 				 "superblock", i);
3253 			if (!sb_rdonly(sb))
3254 				return 0;
3255 		}
3256 		if (block_bitmap >= sb_block + 1 &&
3257 		    block_bitmap <= last_bg_block) {
3258 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3259 				 "Block bitmap for group %u overlaps "
3260 				 "block group descriptors", i);
3261 			if (!sb_rdonly(sb))
3262 				return 0;
3263 		}
3264 		if (block_bitmap < first_block || block_bitmap > last_block) {
3265 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3266 			       "Block bitmap for group %u not in group "
3267 			       "(block %llu)!", i, block_bitmap);
3268 			return 0;
3269 		}
3270 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3271 		if (inode_bitmap == sb_block) {
3272 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3273 				 "Inode bitmap for group %u overlaps "
3274 				 "superblock", i);
3275 			if (!sb_rdonly(sb))
3276 				return 0;
3277 		}
3278 		if (inode_bitmap >= sb_block + 1 &&
3279 		    inode_bitmap <= last_bg_block) {
3280 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3281 				 "Inode bitmap for group %u overlaps "
3282 				 "block group descriptors", i);
3283 			if (!sb_rdonly(sb))
3284 				return 0;
3285 		}
3286 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3287 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3288 			       "Inode bitmap for group %u not in group "
3289 			       "(block %llu)!", i, inode_bitmap);
3290 			return 0;
3291 		}
3292 		inode_table = ext4_inode_table(sb, gdp);
3293 		if (inode_table == sb_block) {
3294 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3295 				 "Inode table for group %u overlaps "
3296 				 "superblock", i);
3297 			if (!sb_rdonly(sb))
3298 				return 0;
3299 		}
3300 		if (inode_table >= sb_block + 1 &&
3301 		    inode_table <= last_bg_block) {
3302 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3303 				 "Inode table for group %u overlaps "
3304 				 "block group descriptors", i);
3305 			if (!sb_rdonly(sb))
3306 				return 0;
3307 		}
3308 		if (inode_table < first_block ||
3309 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3310 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3311 			       "Inode table for group %u not in group "
3312 			       "(block %llu)!", i, inode_table);
3313 			return 0;
3314 		}
3315 		ext4_lock_group(sb, i);
3316 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3317 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3318 				 "Checksum for group %u failed (%u!=%u)",
3319 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3320 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3321 			if (!sb_rdonly(sb)) {
3322 				ext4_unlock_group(sb, i);
3323 				return 0;
3324 			}
3325 		}
3326 		ext4_unlock_group(sb, i);
3327 		if (!flexbg_flag)
3328 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3329 	}
3330 	if (NULL != first_not_zeroed)
3331 		*first_not_zeroed = grp;
3332 	return 1;
3333 }
3334 
3335 /*
3336  * Maximal extent format file size.
3337  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3338  * extent format containers, within a sector_t, and within i_blocks
3339  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3340  * so that won't be a limiting factor.
3341  *
3342  * However there is other limiting factor. We do store extents in the form
3343  * of starting block and length, hence the resulting length of the extent
3344  * covering maximum file size must fit into on-disk format containers as
3345  * well. Given that length is always by 1 unit bigger than max unit (because
3346  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3347  *
3348  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3349  */
3350 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3351 {
3352 	loff_t res;
3353 	loff_t upper_limit = MAX_LFS_FILESIZE;
3354 
3355 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3356 
3357 	if (!has_huge_files) {
3358 		upper_limit = (1LL << 32) - 1;
3359 
3360 		/* total blocks in file system block size */
3361 		upper_limit >>= (blkbits - 9);
3362 		upper_limit <<= blkbits;
3363 	}
3364 
3365 	/*
3366 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3367 	 * by one fs block, so ee_len can cover the extent of maximum file
3368 	 * size
3369 	 */
3370 	res = (1LL << 32) - 1;
3371 	res <<= blkbits;
3372 
3373 	/* Sanity check against vm- & vfs- imposed limits */
3374 	if (res > upper_limit)
3375 		res = upper_limit;
3376 
3377 	return res;
3378 }
3379 
3380 /*
3381  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3382  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3383  * We need to be 1 filesystem block less than the 2^48 sector limit.
3384  */
3385 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3386 {
3387 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3388 	int meta_blocks;
3389 	unsigned int ppb = 1 << (bits - 2);
3390 
3391 	/*
3392 	 * This is calculated to be the largest file size for a dense, block
3393 	 * mapped file such that the file's total number of 512-byte sectors,
3394 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3395 	 *
3396 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3397 	 * number of 512-byte sectors of the file.
3398 	 */
3399 	if (!has_huge_files) {
3400 		/*
3401 		 * !has_huge_files or implies that the inode i_block field
3402 		 * represents total file blocks in 2^32 512-byte sectors ==
3403 		 * size of vfs inode i_blocks * 8
3404 		 */
3405 		upper_limit = (1LL << 32) - 1;
3406 
3407 		/* total blocks in file system block size */
3408 		upper_limit >>= (bits - 9);
3409 
3410 	} else {
3411 		/*
3412 		 * We use 48 bit ext4_inode i_blocks
3413 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3414 		 * represent total number of blocks in
3415 		 * file system block size
3416 		 */
3417 		upper_limit = (1LL << 48) - 1;
3418 
3419 	}
3420 
3421 	/* Compute how many blocks we can address by block tree */
3422 	res += ppb;
3423 	res += ppb * ppb;
3424 	res += ((loff_t)ppb) * ppb * ppb;
3425 	/* Compute how many metadata blocks are needed */
3426 	meta_blocks = 1;
3427 	meta_blocks += 1 + ppb;
3428 	meta_blocks += 1 + ppb + ppb * ppb;
3429 	/* Does block tree limit file size? */
3430 	if (res + meta_blocks <= upper_limit)
3431 		goto check_lfs;
3432 
3433 	res = upper_limit;
3434 	/* How many metadata blocks are needed for addressing upper_limit? */
3435 	upper_limit -= EXT4_NDIR_BLOCKS;
3436 	/* indirect blocks */
3437 	meta_blocks = 1;
3438 	upper_limit -= ppb;
3439 	/* double indirect blocks */
3440 	if (upper_limit < ppb * ppb) {
3441 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3442 		res -= meta_blocks;
3443 		goto check_lfs;
3444 	}
3445 	meta_blocks += 1 + ppb;
3446 	upper_limit -= ppb * ppb;
3447 	/* tripple indirect blocks for the rest */
3448 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3449 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3450 	res -= meta_blocks;
3451 check_lfs:
3452 	res <<= bits;
3453 	if (res > MAX_LFS_FILESIZE)
3454 		res = MAX_LFS_FILESIZE;
3455 
3456 	return res;
3457 }
3458 
3459 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3460 				   ext4_fsblk_t logical_sb_block, int nr)
3461 {
3462 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3463 	ext4_group_t bg, first_meta_bg;
3464 	int has_super = 0;
3465 
3466 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3467 
3468 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3469 		return logical_sb_block + nr + 1;
3470 	bg = sbi->s_desc_per_block * nr;
3471 	if (ext4_bg_has_super(sb, bg))
3472 		has_super = 1;
3473 
3474 	/*
3475 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3476 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3477 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3478 	 * compensate.
3479 	 */
3480 	if (sb->s_blocksize == 1024 && nr == 0 &&
3481 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3482 		has_super++;
3483 
3484 	return (has_super + ext4_group_first_block_no(sb, bg));
3485 }
3486 
3487 /**
3488  * ext4_get_stripe_size: Get the stripe size.
3489  * @sbi: In memory super block info
3490  *
3491  * If we have specified it via mount option, then
3492  * use the mount option value. If the value specified at mount time is
3493  * greater than the blocks per group use the super block value.
3494  * If the super block value is greater than blocks per group return 0.
3495  * Allocator needs it be less than blocks per group.
3496  *
3497  */
3498 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3499 {
3500 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3501 	unsigned long stripe_width =
3502 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3503 	int ret;
3504 
3505 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3506 		ret = sbi->s_stripe;
3507 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3508 		ret = stripe_width;
3509 	else if (stride && stride <= sbi->s_blocks_per_group)
3510 		ret = stride;
3511 	else
3512 		ret = 0;
3513 
3514 	/*
3515 	 * If the stripe width is 1, this makes no sense and
3516 	 * we set it to 0 to turn off stripe handling code.
3517 	 */
3518 	if (ret <= 1)
3519 		ret = 0;
3520 
3521 	return ret;
3522 }
3523 
3524 /*
3525  * Check whether this filesystem can be mounted based on
3526  * the features present and the RDONLY/RDWR mount requested.
3527  * Returns 1 if this filesystem can be mounted as requested,
3528  * 0 if it cannot be.
3529  */
3530 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3531 {
3532 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3533 		ext4_msg(sb, KERN_ERR,
3534 			"Couldn't mount because of "
3535 			"unsupported optional features (%x)",
3536 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3537 			~EXT4_FEATURE_INCOMPAT_SUPP));
3538 		return 0;
3539 	}
3540 
3541 #if !IS_ENABLED(CONFIG_UNICODE)
3542 	if (ext4_has_feature_casefold(sb)) {
3543 		ext4_msg(sb, KERN_ERR,
3544 			 "Filesystem with casefold feature cannot be "
3545 			 "mounted without CONFIG_UNICODE");
3546 		return 0;
3547 	}
3548 #endif
3549 
3550 	if (readonly)
3551 		return 1;
3552 
3553 	if (ext4_has_feature_readonly(sb)) {
3554 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3555 		sb->s_flags |= SB_RDONLY;
3556 		return 1;
3557 	}
3558 
3559 	/* Check that feature set is OK for a read-write mount */
3560 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3561 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3562 			 "unsupported optional features (%x)",
3563 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3564 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3565 		return 0;
3566 	}
3567 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3568 		ext4_msg(sb, KERN_ERR,
3569 			 "Can't support bigalloc feature without "
3570 			 "extents feature\n");
3571 		return 0;
3572 	}
3573 
3574 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3575 	if (!readonly && (ext4_has_feature_quota(sb) ||
3576 			  ext4_has_feature_project(sb))) {
3577 		ext4_msg(sb, KERN_ERR,
3578 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3579 		return 0;
3580 	}
3581 #endif  /* CONFIG_QUOTA */
3582 	return 1;
3583 }
3584 
3585 /*
3586  * This function is called once a day if we have errors logged
3587  * on the file system
3588  */
3589 static void print_daily_error_info(struct timer_list *t)
3590 {
3591 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3592 	struct super_block *sb = sbi->s_sb;
3593 	struct ext4_super_block *es = sbi->s_es;
3594 
3595 	if (es->s_error_count)
3596 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3597 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3598 			 le32_to_cpu(es->s_error_count));
3599 	if (es->s_first_error_time) {
3600 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3601 		       sb->s_id,
3602 		       ext4_get_tstamp(es, s_first_error_time),
3603 		       (int) sizeof(es->s_first_error_func),
3604 		       es->s_first_error_func,
3605 		       le32_to_cpu(es->s_first_error_line));
3606 		if (es->s_first_error_ino)
3607 			printk(KERN_CONT ": inode %u",
3608 			       le32_to_cpu(es->s_first_error_ino));
3609 		if (es->s_first_error_block)
3610 			printk(KERN_CONT ": block %llu", (unsigned long long)
3611 			       le64_to_cpu(es->s_first_error_block));
3612 		printk(KERN_CONT "\n");
3613 	}
3614 	if (es->s_last_error_time) {
3615 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3616 		       sb->s_id,
3617 		       ext4_get_tstamp(es, s_last_error_time),
3618 		       (int) sizeof(es->s_last_error_func),
3619 		       es->s_last_error_func,
3620 		       le32_to_cpu(es->s_last_error_line));
3621 		if (es->s_last_error_ino)
3622 			printk(KERN_CONT ": inode %u",
3623 			       le32_to_cpu(es->s_last_error_ino));
3624 		if (es->s_last_error_block)
3625 			printk(KERN_CONT ": block %llu", (unsigned long long)
3626 			       le64_to_cpu(es->s_last_error_block));
3627 		printk(KERN_CONT "\n");
3628 	}
3629 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3630 }
3631 
3632 /* Find next suitable group and run ext4_init_inode_table */
3633 static int ext4_run_li_request(struct ext4_li_request *elr)
3634 {
3635 	struct ext4_group_desc *gdp = NULL;
3636 	struct super_block *sb = elr->lr_super;
3637 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3638 	ext4_group_t group = elr->lr_next_group;
3639 	unsigned int prefetch_ios = 0;
3640 	int ret = 0;
3641 	u64 start_time;
3642 
3643 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3644 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3645 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3646 		if (prefetch_ios)
3647 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3648 					      prefetch_ios);
3649 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3650 					    prefetch_ios);
3651 		if (group >= elr->lr_next_group) {
3652 			ret = 1;
3653 			if (elr->lr_first_not_zeroed != ngroups &&
3654 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3655 				elr->lr_next_group = elr->lr_first_not_zeroed;
3656 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3657 				ret = 0;
3658 			}
3659 		}
3660 		return ret;
3661 	}
3662 
3663 	for (; group < ngroups; group++) {
3664 		gdp = ext4_get_group_desc(sb, group, NULL);
3665 		if (!gdp) {
3666 			ret = 1;
3667 			break;
3668 		}
3669 
3670 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3671 			break;
3672 	}
3673 
3674 	if (group >= ngroups)
3675 		ret = 1;
3676 
3677 	if (!ret) {
3678 		start_time = ktime_get_real_ns();
3679 		ret = ext4_init_inode_table(sb, group,
3680 					    elr->lr_timeout ? 0 : 1);
3681 		trace_ext4_lazy_itable_init(sb, group);
3682 		if (elr->lr_timeout == 0) {
3683 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3684 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3685 		}
3686 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3687 		elr->lr_next_group = group + 1;
3688 	}
3689 	return ret;
3690 }
3691 
3692 /*
3693  * Remove lr_request from the list_request and free the
3694  * request structure. Should be called with li_list_mtx held
3695  */
3696 static void ext4_remove_li_request(struct ext4_li_request *elr)
3697 {
3698 	if (!elr)
3699 		return;
3700 
3701 	list_del(&elr->lr_request);
3702 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3703 	kfree(elr);
3704 }
3705 
3706 static void ext4_unregister_li_request(struct super_block *sb)
3707 {
3708 	mutex_lock(&ext4_li_mtx);
3709 	if (!ext4_li_info) {
3710 		mutex_unlock(&ext4_li_mtx);
3711 		return;
3712 	}
3713 
3714 	mutex_lock(&ext4_li_info->li_list_mtx);
3715 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3716 	mutex_unlock(&ext4_li_info->li_list_mtx);
3717 	mutex_unlock(&ext4_li_mtx);
3718 }
3719 
3720 static struct task_struct *ext4_lazyinit_task;
3721 
3722 /*
3723  * This is the function where ext4lazyinit thread lives. It walks
3724  * through the request list searching for next scheduled filesystem.
3725  * When such a fs is found, run the lazy initialization request
3726  * (ext4_rn_li_request) and keep track of the time spend in this
3727  * function. Based on that time we compute next schedule time of
3728  * the request. When walking through the list is complete, compute
3729  * next waking time and put itself into sleep.
3730  */
3731 static int ext4_lazyinit_thread(void *arg)
3732 {
3733 	struct ext4_lazy_init *eli = arg;
3734 	struct list_head *pos, *n;
3735 	struct ext4_li_request *elr;
3736 	unsigned long next_wakeup, cur;
3737 
3738 	BUG_ON(NULL == eli);
3739 	set_freezable();
3740 
3741 cont_thread:
3742 	while (true) {
3743 		next_wakeup = MAX_JIFFY_OFFSET;
3744 
3745 		mutex_lock(&eli->li_list_mtx);
3746 		if (list_empty(&eli->li_request_list)) {
3747 			mutex_unlock(&eli->li_list_mtx);
3748 			goto exit_thread;
3749 		}
3750 		list_for_each_safe(pos, n, &eli->li_request_list) {
3751 			int err = 0;
3752 			int progress = 0;
3753 			elr = list_entry(pos, struct ext4_li_request,
3754 					 lr_request);
3755 
3756 			if (time_before(jiffies, elr->lr_next_sched)) {
3757 				if (time_before(elr->lr_next_sched, next_wakeup))
3758 					next_wakeup = elr->lr_next_sched;
3759 				continue;
3760 			}
3761 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3762 				if (sb_start_write_trylock(elr->lr_super)) {
3763 					progress = 1;
3764 					/*
3765 					 * We hold sb->s_umount, sb can not
3766 					 * be removed from the list, it is
3767 					 * now safe to drop li_list_mtx
3768 					 */
3769 					mutex_unlock(&eli->li_list_mtx);
3770 					err = ext4_run_li_request(elr);
3771 					sb_end_write(elr->lr_super);
3772 					mutex_lock(&eli->li_list_mtx);
3773 					n = pos->next;
3774 				}
3775 				up_read((&elr->lr_super->s_umount));
3776 			}
3777 			/* error, remove the lazy_init job */
3778 			if (err) {
3779 				ext4_remove_li_request(elr);
3780 				continue;
3781 			}
3782 			if (!progress) {
3783 				elr->lr_next_sched = jiffies +
3784 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3785 			}
3786 			if (time_before(elr->lr_next_sched, next_wakeup))
3787 				next_wakeup = elr->lr_next_sched;
3788 		}
3789 		mutex_unlock(&eli->li_list_mtx);
3790 
3791 		try_to_freeze();
3792 
3793 		cur = jiffies;
3794 		if ((time_after_eq(cur, next_wakeup)) ||
3795 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3796 			cond_resched();
3797 			continue;
3798 		}
3799 
3800 		schedule_timeout_interruptible(next_wakeup - cur);
3801 
3802 		if (kthread_should_stop()) {
3803 			ext4_clear_request_list();
3804 			goto exit_thread;
3805 		}
3806 	}
3807 
3808 exit_thread:
3809 	/*
3810 	 * It looks like the request list is empty, but we need
3811 	 * to check it under the li_list_mtx lock, to prevent any
3812 	 * additions into it, and of course we should lock ext4_li_mtx
3813 	 * to atomically free the list and ext4_li_info, because at
3814 	 * this point another ext4 filesystem could be registering
3815 	 * new one.
3816 	 */
3817 	mutex_lock(&ext4_li_mtx);
3818 	mutex_lock(&eli->li_list_mtx);
3819 	if (!list_empty(&eli->li_request_list)) {
3820 		mutex_unlock(&eli->li_list_mtx);
3821 		mutex_unlock(&ext4_li_mtx);
3822 		goto cont_thread;
3823 	}
3824 	mutex_unlock(&eli->li_list_mtx);
3825 	kfree(ext4_li_info);
3826 	ext4_li_info = NULL;
3827 	mutex_unlock(&ext4_li_mtx);
3828 
3829 	return 0;
3830 }
3831 
3832 static void ext4_clear_request_list(void)
3833 {
3834 	struct list_head *pos, *n;
3835 	struct ext4_li_request *elr;
3836 
3837 	mutex_lock(&ext4_li_info->li_list_mtx);
3838 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3839 		elr = list_entry(pos, struct ext4_li_request,
3840 				 lr_request);
3841 		ext4_remove_li_request(elr);
3842 	}
3843 	mutex_unlock(&ext4_li_info->li_list_mtx);
3844 }
3845 
3846 static int ext4_run_lazyinit_thread(void)
3847 {
3848 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3849 					 ext4_li_info, "ext4lazyinit");
3850 	if (IS_ERR(ext4_lazyinit_task)) {
3851 		int err = PTR_ERR(ext4_lazyinit_task);
3852 		ext4_clear_request_list();
3853 		kfree(ext4_li_info);
3854 		ext4_li_info = NULL;
3855 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3856 				 "initialization thread\n",
3857 				 err);
3858 		return err;
3859 	}
3860 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3861 	return 0;
3862 }
3863 
3864 /*
3865  * Check whether it make sense to run itable init. thread or not.
3866  * If there is at least one uninitialized inode table, return
3867  * corresponding group number, else the loop goes through all
3868  * groups and return total number of groups.
3869  */
3870 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3871 {
3872 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3873 	struct ext4_group_desc *gdp = NULL;
3874 
3875 	if (!ext4_has_group_desc_csum(sb))
3876 		return ngroups;
3877 
3878 	for (group = 0; group < ngroups; group++) {
3879 		gdp = ext4_get_group_desc(sb, group, NULL);
3880 		if (!gdp)
3881 			continue;
3882 
3883 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3884 			break;
3885 	}
3886 
3887 	return group;
3888 }
3889 
3890 static int ext4_li_info_new(void)
3891 {
3892 	struct ext4_lazy_init *eli = NULL;
3893 
3894 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3895 	if (!eli)
3896 		return -ENOMEM;
3897 
3898 	INIT_LIST_HEAD(&eli->li_request_list);
3899 	mutex_init(&eli->li_list_mtx);
3900 
3901 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3902 
3903 	ext4_li_info = eli;
3904 
3905 	return 0;
3906 }
3907 
3908 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3909 					    ext4_group_t start)
3910 {
3911 	struct ext4_li_request *elr;
3912 
3913 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3914 	if (!elr)
3915 		return NULL;
3916 
3917 	elr->lr_super = sb;
3918 	elr->lr_first_not_zeroed = start;
3919 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3920 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3921 		elr->lr_next_group = start;
3922 	} else {
3923 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3924 	}
3925 
3926 	/*
3927 	 * Randomize first schedule time of the request to
3928 	 * spread the inode table initialization requests
3929 	 * better.
3930 	 */
3931 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3932 	return elr;
3933 }
3934 
3935 int ext4_register_li_request(struct super_block *sb,
3936 			     ext4_group_t first_not_zeroed)
3937 {
3938 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3939 	struct ext4_li_request *elr = NULL;
3940 	ext4_group_t ngroups = sbi->s_groups_count;
3941 	int ret = 0;
3942 
3943 	mutex_lock(&ext4_li_mtx);
3944 	if (sbi->s_li_request != NULL) {
3945 		/*
3946 		 * Reset timeout so it can be computed again, because
3947 		 * s_li_wait_mult might have changed.
3948 		 */
3949 		sbi->s_li_request->lr_timeout = 0;
3950 		goto out;
3951 	}
3952 
3953 	if (sb_rdonly(sb) ||
3954 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3955 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
3956 		goto out;
3957 
3958 	elr = ext4_li_request_new(sb, first_not_zeroed);
3959 	if (!elr) {
3960 		ret = -ENOMEM;
3961 		goto out;
3962 	}
3963 
3964 	if (NULL == ext4_li_info) {
3965 		ret = ext4_li_info_new();
3966 		if (ret)
3967 			goto out;
3968 	}
3969 
3970 	mutex_lock(&ext4_li_info->li_list_mtx);
3971 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3972 	mutex_unlock(&ext4_li_info->li_list_mtx);
3973 
3974 	sbi->s_li_request = elr;
3975 	/*
3976 	 * set elr to NULL here since it has been inserted to
3977 	 * the request_list and the removal and free of it is
3978 	 * handled by ext4_clear_request_list from now on.
3979 	 */
3980 	elr = NULL;
3981 
3982 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3983 		ret = ext4_run_lazyinit_thread();
3984 		if (ret)
3985 			goto out;
3986 	}
3987 out:
3988 	mutex_unlock(&ext4_li_mtx);
3989 	if (ret)
3990 		kfree(elr);
3991 	return ret;
3992 }
3993 
3994 /*
3995  * We do not need to lock anything since this is called on
3996  * module unload.
3997  */
3998 static void ext4_destroy_lazyinit_thread(void)
3999 {
4000 	/*
4001 	 * If thread exited earlier
4002 	 * there's nothing to be done.
4003 	 */
4004 	if (!ext4_li_info || !ext4_lazyinit_task)
4005 		return;
4006 
4007 	kthread_stop(ext4_lazyinit_task);
4008 }
4009 
4010 static int set_journal_csum_feature_set(struct super_block *sb)
4011 {
4012 	int ret = 1;
4013 	int compat, incompat;
4014 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4015 
4016 	if (ext4_has_metadata_csum(sb)) {
4017 		/* journal checksum v3 */
4018 		compat = 0;
4019 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4020 	} else {
4021 		/* journal checksum v1 */
4022 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4023 		incompat = 0;
4024 	}
4025 
4026 	jbd2_journal_clear_features(sbi->s_journal,
4027 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4028 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4029 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4030 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4031 		ret = jbd2_journal_set_features(sbi->s_journal,
4032 				compat, 0,
4033 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4034 				incompat);
4035 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4036 		ret = jbd2_journal_set_features(sbi->s_journal,
4037 				compat, 0,
4038 				incompat);
4039 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4040 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4041 	} else {
4042 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4043 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4044 	}
4045 
4046 	return ret;
4047 }
4048 
4049 /*
4050  * Note: calculating the overhead so we can be compatible with
4051  * historical BSD practice is quite difficult in the face of
4052  * clusters/bigalloc.  This is because multiple metadata blocks from
4053  * different block group can end up in the same allocation cluster.
4054  * Calculating the exact overhead in the face of clustered allocation
4055  * requires either O(all block bitmaps) in memory or O(number of block
4056  * groups**2) in time.  We will still calculate the superblock for
4057  * older file systems --- and if we come across with a bigalloc file
4058  * system with zero in s_overhead_clusters the estimate will be close to
4059  * correct especially for very large cluster sizes --- but for newer
4060  * file systems, it's better to calculate this figure once at mkfs
4061  * time, and store it in the superblock.  If the superblock value is
4062  * present (even for non-bigalloc file systems), we will use it.
4063  */
4064 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4065 			  char *buf)
4066 {
4067 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4068 	struct ext4_group_desc	*gdp;
4069 	ext4_fsblk_t		first_block, last_block, b;
4070 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4071 	int			s, j, count = 0;
4072 	int			has_super = ext4_bg_has_super(sb, grp);
4073 
4074 	if (!ext4_has_feature_bigalloc(sb))
4075 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4076 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4077 			sbi->s_itb_per_group + 2);
4078 
4079 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4080 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4081 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4082 	for (i = 0; i < ngroups; i++) {
4083 		gdp = ext4_get_group_desc(sb, i, NULL);
4084 		b = ext4_block_bitmap(sb, gdp);
4085 		if (b >= first_block && b <= last_block) {
4086 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4087 			count++;
4088 		}
4089 		b = ext4_inode_bitmap(sb, gdp);
4090 		if (b >= first_block && b <= last_block) {
4091 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4092 			count++;
4093 		}
4094 		b = ext4_inode_table(sb, gdp);
4095 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4096 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4097 				int c = EXT4_B2C(sbi, b - first_block);
4098 				ext4_set_bit(c, buf);
4099 				count++;
4100 			}
4101 		if (i != grp)
4102 			continue;
4103 		s = 0;
4104 		if (ext4_bg_has_super(sb, grp)) {
4105 			ext4_set_bit(s++, buf);
4106 			count++;
4107 		}
4108 		j = ext4_bg_num_gdb(sb, grp);
4109 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4110 			ext4_error(sb, "Invalid number of block group "
4111 				   "descriptor blocks: %d", j);
4112 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4113 		}
4114 		count += j;
4115 		for (; j > 0; j--)
4116 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4117 	}
4118 	if (!count)
4119 		return 0;
4120 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4121 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4122 }
4123 
4124 /*
4125  * Compute the overhead and stash it in sbi->s_overhead
4126  */
4127 int ext4_calculate_overhead(struct super_block *sb)
4128 {
4129 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4130 	struct ext4_super_block *es = sbi->s_es;
4131 	struct inode *j_inode;
4132 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4133 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4134 	ext4_fsblk_t overhead = 0;
4135 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4136 
4137 	if (!buf)
4138 		return -ENOMEM;
4139 
4140 	/*
4141 	 * Compute the overhead (FS structures).  This is constant
4142 	 * for a given filesystem unless the number of block groups
4143 	 * changes so we cache the previous value until it does.
4144 	 */
4145 
4146 	/*
4147 	 * All of the blocks before first_data_block are overhead
4148 	 */
4149 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4150 
4151 	/*
4152 	 * Add the overhead found in each block group
4153 	 */
4154 	for (i = 0; i < ngroups; i++) {
4155 		int blks;
4156 
4157 		blks = count_overhead(sb, i, buf);
4158 		overhead += blks;
4159 		if (blks)
4160 			memset(buf, 0, PAGE_SIZE);
4161 		cond_resched();
4162 	}
4163 
4164 	/*
4165 	 * Add the internal journal blocks whether the journal has been
4166 	 * loaded or not
4167 	 */
4168 	if (sbi->s_journal && !sbi->s_journal_bdev)
4169 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4170 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4171 		/* j_inum for internal journal is non-zero */
4172 		j_inode = ext4_get_journal_inode(sb, j_inum);
4173 		if (j_inode) {
4174 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4175 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4176 			iput(j_inode);
4177 		} else {
4178 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4179 		}
4180 	}
4181 	sbi->s_overhead = overhead;
4182 	smp_wmb();
4183 	free_page((unsigned long) buf);
4184 	return 0;
4185 }
4186 
4187 static void ext4_set_resv_clusters(struct super_block *sb)
4188 {
4189 	ext4_fsblk_t resv_clusters;
4190 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4191 
4192 	/*
4193 	 * There's no need to reserve anything when we aren't using extents.
4194 	 * The space estimates are exact, there are no unwritten extents,
4195 	 * hole punching doesn't need new metadata... This is needed especially
4196 	 * to keep ext2/3 backward compatibility.
4197 	 */
4198 	if (!ext4_has_feature_extents(sb))
4199 		return;
4200 	/*
4201 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4202 	 * This should cover the situations where we can not afford to run
4203 	 * out of space like for example punch hole, or converting
4204 	 * unwritten extents in delalloc path. In most cases such
4205 	 * allocation would require 1, or 2 blocks, higher numbers are
4206 	 * very rare.
4207 	 */
4208 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4209 			 sbi->s_cluster_bits);
4210 
4211 	do_div(resv_clusters, 50);
4212 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4213 
4214 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4215 }
4216 
4217 static const char *ext4_quota_mode(struct super_block *sb)
4218 {
4219 #ifdef CONFIG_QUOTA
4220 	if (!ext4_quota_capable(sb))
4221 		return "none";
4222 
4223 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4224 		return "journalled";
4225 	else
4226 		return "writeback";
4227 #else
4228 	return "disabled";
4229 #endif
4230 }
4231 
4232 static void ext4_setup_csum_trigger(struct super_block *sb,
4233 				    enum ext4_journal_trigger_type type,
4234 				    void (*trigger)(
4235 					struct jbd2_buffer_trigger_type *type,
4236 					struct buffer_head *bh,
4237 					void *mapped_data,
4238 					size_t size))
4239 {
4240 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4241 
4242 	sbi->s_journal_triggers[type].sb = sb;
4243 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4244 }
4245 
4246 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4247 {
4248 	if (!sbi)
4249 		return;
4250 
4251 	kfree(sbi->s_blockgroup_lock);
4252 	fs_put_dax(sbi->s_daxdev, NULL);
4253 	kfree(sbi);
4254 }
4255 
4256 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4257 {
4258 	struct ext4_sb_info *sbi;
4259 
4260 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4261 	if (!sbi)
4262 		return NULL;
4263 
4264 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4265 					   NULL, NULL);
4266 
4267 	sbi->s_blockgroup_lock =
4268 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4269 
4270 	if (!sbi->s_blockgroup_lock)
4271 		goto err_out;
4272 
4273 	sb->s_fs_info = sbi;
4274 	sbi->s_sb = sb;
4275 	return sbi;
4276 err_out:
4277 	fs_put_dax(sbi->s_daxdev, NULL);
4278 	kfree(sbi);
4279 	return NULL;
4280 }
4281 
4282 static void ext4_set_def_opts(struct super_block *sb,
4283 			      struct ext4_super_block *es)
4284 {
4285 	unsigned long def_mount_opts;
4286 
4287 	/* Set defaults before we parse the mount options */
4288 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4289 	set_opt(sb, INIT_INODE_TABLE);
4290 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4291 		set_opt(sb, DEBUG);
4292 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4293 		set_opt(sb, GRPID);
4294 	if (def_mount_opts & EXT4_DEFM_UID16)
4295 		set_opt(sb, NO_UID32);
4296 	/* xattr user namespace & acls are now defaulted on */
4297 	set_opt(sb, XATTR_USER);
4298 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4299 	set_opt(sb, POSIX_ACL);
4300 #endif
4301 	if (ext4_has_feature_fast_commit(sb))
4302 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4303 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4304 	if (ext4_has_metadata_csum(sb))
4305 		set_opt(sb, JOURNAL_CHECKSUM);
4306 
4307 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4308 		set_opt(sb, JOURNAL_DATA);
4309 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4310 		set_opt(sb, ORDERED_DATA);
4311 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4312 		set_opt(sb, WRITEBACK_DATA);
4313 
4314 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4315 		set_opt(sb, ERRORS_PANIC);
4316 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4317 		set_opt(sb, ERRORS_CONT);
4318 	else
4319 		set_opt(sb, ERRORS_RO);
4320 	/* block_validity enabled by default; disable with noblock_validity */
4321 	set_opt(sb, BLOCK_VALIDITY);
4322 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4323 		set_opt(sb, DISCARD);
4324 
4325 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4326 		set_opt(sb, BARRIER);
4327 
4328 	/*
4329 	 * enable delayed allocation by default
4330 	 * Use -o nodelalloc to turn it off
4331 	 */
4332 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4333 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4334 		set_opt(sb, DELALLOC);
4335 
4336 	if (sb->s_blocksize == PAGE_SIZE)
4337 		set_opt(sb, DIOREAD_NOLOCK);
4338 }
4339 
4340 static int ext4_handle_clustersize(struct super_block *sb)
4341 {
4342 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4343 	struct ext4_super_block *es = sbi->s_es;
4344 	int clustersize;
4345 
4346 	/* Handle clustersize */
4347 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4348 	if (ext4_has_feature_bigalloc(sb)) {
4349 		if (clustersize < sb->s_blocksize) {
4350 			ext4_msg(sb, KERN_ERR,
4351 				 "cluster size (%d) smaller than "
4352 				 "block size (%lu)", clustersize, sb->s_blocksize);
4353 			return -EINVAL;
4354 		}
4355 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4356 			le32_to_cpu(es->s_log_block_size);
4357 		sbi->s_clusters_per_group =
4358 			le32_to_cpu(es->s_clusters_per_group);
4359 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4360 			ext4_msg(sb, KERN_ERR,
4361 				 "#clusters per group too big: %lu",
4362 				 sbi->s_clusters_per_group);
4363 			return -EINVAL;
4364 		}
4365 		if (sbi->s_blocks_per_group !=
4366 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4367 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4368 				 "clusters per group (%lu) inconsistent",
4369 				 sbi->s_blocks_per_group,
4370 				 sbi->s_clusters_per_group);
4371 			return -EINVAL;
4372 		}
4373 	} else {
4374 		if (clustersize != sb->s_blocksize) {
4375 			ext4_msg(sb, KERN_ERR,
4376 				 "fragment/cluster size (%d) != "
4377 				 "block size (%lu)", clustersize, sb->s_blocksize);
4378 			return -EINVAL;
4379 		}
4380 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4381 			ext4_msg(sb, KERN_ERR,
4382 				 "#blocks per group too big: %lu",
4383 				 sbi->s_blocks_per_group);
4384 			return -EINVAL;
4385 		}
4386 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4387 		sbi->s_cluster_bits = 0;
4388 	}
4389 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4390 
4391 	/* Do we have standard group size of clustersize * 8 blocks ? */
4392 	if (sbi->s_blocks_per_group == clustersize << 3)
4393 		set_opt2(sb, STD_GROUP_SIZE);
4394 
4395 	return 0;
4396 }
4397 
4398 static void ext4_fast_commit_init(struct super_block *sb)
4399 {
4400 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4401 
4402 	/* Initialize fast commit stuff */
4403 	atomic_set(&sbi->s_fc_subtid, 0);
4404 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4405 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4406 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4407 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4408 	sbi->s_fc_bytes = 0;
4409 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4410 	sbi->s_fc_ineligible_tid = 0;
4411 	spin_lock_init(&sbi->s_fc_lock);
4412 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4413 	sbi->s_fc_replay_state.fc_regions = NULL;
4414 	sbi->s_fc_replay_state.fc_regions_size = 0;
4415 	sbi->s_fc_replay_state.fc_regions_used = 0;
4416 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4417 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4418 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4419 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4420 }
4421 
4422 static int ext4_inode_info_init(struct super_block *sb,
4423 				struct ext4_super_block *es)
4424 {
4425 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4426 
4427 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4428 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4429 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4430 	} else {
4431 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4432 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4433 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4434 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4435 				 sbi->s_first_ino);
4436 			return -EINVAL;
4437 		}
4438 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4439 		    (!is_power_of_2(sbi->s_inode_size)) ||
4440 		    (sbi->s_inode_size > sb->s_blocksize)) {
4441 			ext4_msg(sb, KERN_ERR,
4442 			       "unsupported inode size: %d",
4443 			       sbi->s_inode_size);
4444 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4445 			return -EINVAL;
4446 		}
4447 		/*
4448 		 * i_atime_extra is the last extra field available for
4449 		 * [acm]times in struct ext4_inode. Checking for that
4450 		 * field should suffice to ensure we have extra space
4451 		 * for all three.
4452 		 */
4453 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4454 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4455 			sb->s_time_gran = 1;
4456 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4457 		} else {
4458 			sb->s_time_gran = NSEC_PER_SEC;
4459 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4460 		}
4461 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4462 	}
4463 
4464 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4465 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4466 			EXT4_GOOD_OLD_INODE_SIZE;
4467 		if (ext4_has_feature_extra_isize(sb)) {
4468 			unsigned v, max = (sbi->s_inode_size -
4469 					   EXT4_GOOD_OLD_INODE_SIZE);
4470 
4471 			v = le16_to_cpu(es->s_want_extra_isize);
4472 			if (v > max) {
4473 				ext4_msg(sb, KERN_ERR,
4474 					 "bad s_want_extra_isize: %d", v);
4475 				return -EINVAL;
4476 			}
4477 			if (sbi->s_want_extra_isize < v)
4478 				sbi->s_want_extra_isize = v;
4479 
4480 			v = le16_to_cpu(es->s_min_extra_isize);
4481 			if (v > max) {
4482 				ext4_msg(sb, KERN_ERR,
4483 					 "bad s_min_extra_isize: %d", v);
4484 				return -EINVAL;
4485 			}
4486 			if (sbi->s_want_extra_isize < v)
4487 				sbi->s_want_extra_isize = v;
4488 		}
4489 	}
4490 
4491 	return 0;
4492 }
4493 
4494 #if IS_ENABLED(CONFIG_UNICODE)
4495 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4496 {
4497 	const struct ext4_sb_encodings *encoding_info;
4498 	struct unicode_map *encoding;
4499 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4500 
4501 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4502 		return 0;
4503 
4504 	encoding_info = ext4_sb_read_encoding(es);
4505 	if (!encoding_info) {
4506 		ext4_msg(sb, KERN_ERR,
4507 			"Encoding requested by superblock is unknown");
4508 		return -EINVAL;
4509 	}
4510 
4511 	encoding = utf8_load(encoding_info->version);
4512 	if (IS_ERR(encoding)) {
4513 		ext4_msg(sb, KERN_ERR,
4514 			"can't mount with superblock charset: %s-%u.%u.%u "
4515 			"not supported by the kernel. flags: 0x%x.",
4516 			encoding_info->name,
4517 			unicode_major(encoding_info->version),
4518 			unicode_minor(encoding_info->version),
4519 			unicode_rev(encoding_info->version),
4520 			encoding_flags);
4521 		return -EINVAL;
4522 	}
4523 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4524 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4525 		unicode_major(encoding_info->version),
4526 		unicode_minor(encoding_info->version),
4527 		unicode_rev(encoding_info->version),
4528 		encoding_flags);
4529 
4530 	sb->s_encoding = encoding;
4531 	sb->s_encoding_flags = encoding_flags;
4532 
4533 	return 0;
4534 }
4535 #else
4536 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4537 {
4538 	return 0;
4539 }
4540 #endif
4541 
4542 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4543 {
4544 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4545 
4546 	/* Warn if metadata_csum and gdt_csum are both set. */
4547 	if (ext4_has_feature_metadata_csum(sb) &&
4548 	    ext4_has_feature_gdt_csum(sb))
4549 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4550 			     "redundant flags; please run fsck.");
4551 
4552 	/* Check for a known checksum algorithm */
4553 	if (!ext4_verify_csum_type(sb, es)) {
4554 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4555 			 "unknown checksum algorithm.");
4556 		return -EINVAL;
4557 	}
4558 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4559 				ext4_orphan_file_block_trigger);
4560 
4561 	/* Load the checksum driver */
4562 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4563 	if (IS_ERR(sbi->s_chksum_driver)) {
4564 		int ret = PTR_ERR(sbi->s_chksum_driver);
4565 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4566 		sbi->s_chksum_driver = NULL;
4567 		return ret;
4568 	}
4569 
4570 	/* Check superblock checksum */
4571 	if (!ext4_superblock_csum_verify(sb, es)) {
4572 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4573 			 "invalid superblock checksum.  Run e2fsck?");
4574 		return -EFSBADCRC;
4575 	}
4576 
4577 	/* Precompute checksum seed for all metadata */
4578 	if (ext4_has_feature_csum_seed(sb))
4579 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4580 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4581 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4582 					       sizeof(es->s_uuid));
4583 	return 0;
4584 }
4585 
4586 static int ext4_check_feature_compatibility(struct super_block *sb,
4587 					    struct ext4_super_block *es,
4588 					    int silent)
4589 {
4590 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4591 	    (ext4_has_compat_features(sb) ||
4592 	     ext4_has_ro_compat_features(sb) ||
4593 	     ext4_has_incompat_features(sb)))
4594 		ext4_msg(sb, KERN_WARNING,
4595 		       "feature flags set on rev 0 fs, "
4596 		       "running e2fsck is recommended");
4597 
4598 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4599 		set_opt2(sb, HURD_COMPAT);
4600 		if (ext4_has_feature_64bit(sb)) {
4601 			ext4_msg(sb, KERN_ERR,
4602 				 "The Hurd can't support 64-bit file systems");
4603 			return -EINVAL;
4604 		}
4605 
4606 		/*
4607 		 * ea_inode feature uses l_i_version field which is not
4608 		 * available in HURD_COMPAT mode.
4609 		 */
4610 		if (ext4_has_feature_ea_inode(sb)) {
4611 			ext4_msg(sb, KERN_ERR,
4612 				 "ea_inode feature is not supported for Hurd");
4613 			return -EINVAL;
4614 		}
4615 	}
4616 
4617 	if (IS_EXT2_SB(sb)) {
4618 		if (ext2_feature_set_ok(sb))
4619 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4620 				 "using the ext4 subsystem");
4621 		else {
4622 			/*
4623 			 * If we're probing be silent, if this looks like
4624 			 * it's actually an ext[34] filesystem.
4625 			 */
4626 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4627 				return -EINVAL;
4628 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4629 				 "to feature incompatibilities");
4630 			return -EINVAL;
4631 		}
4632 	}
4633 
4634 	if (IS_EXT3_SB(sb)) {
4635 		if (ext3_feature_set_ok(sb))
4636 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4637 				 "using the ext4 subsystem");
4638 		else {
4639 			/*
4640 			 * If we're probing be silent, if this looks like
4641 			 * it's actually an ext4 filesystem.
4642 			 */
4643 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4644 				return -EINVAL;
4645 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4646 				 "to feature incompatibilities");
4647 			return -EINVAL;
4648 		}
4649 	}
4650 
4651 	/*
4652 	 * Check feature flags regardless of the revision level, since we
4653 	 * previously didn't change the revision level when setting the flags,
4654 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4655 	 */
4656 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4657 		return -EINVAL;
4658 
4659 	return 0;
4660 }
4661 
4662 static int ext4_geometry_check(struct super_block *sb,
4663 			       struct ext4_super_block *es)
4664 {
4665 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4666 	__u64 blocks_count;
4667 
4668 	/* check blocks count against device size */
4669 	blocks_count = sb_bdev_nr_blocks(sb);
4670 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4671 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4672 		       "exceeds size of device (%llu blocks)",
4673 		       ext4_blocks_count(es), blocks_count);
4674 		return -EINVAL;
4675 	}
4676 
4677 	/*
4678 	 * It makes no sense for the first data block to be beyond the end
4679 	 * of the filesystem.
4680 	 */
4681 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4682 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4683 			 "block %u is beyond end of filesystem (%llu)",
4684 			 le32_to_cpu(es->s_first_data_block),
4685 			 ext4_blocks_count(es));
4686 		return -EINVAL;
4687 	}
4688 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4689 	    (sbi->s_cluster_ratio == 1)) {
4690 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4691 			 "block is 0 with a 1k block and cluster size");
4692 		return -EINVAL;
4693 	}
4694 
4695 	blocks_count = (ext4_blocks_count(es) -
4696 			le32_to_cpu(es->s_first_data_block) +
4697 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4698 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4699 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4700 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4701 		       "(block count %llu, first data block %u, "
4702 		       "blocks per group %lu)", blocks_count,
4703 		       ext4_blocks_count(es),
4704 		       le32_to_cpu(es->s_first_data_block),
4705 		       EXT4_BLOCKS_PER_GROUP(sb));
4706 		return -EINVAL;
4707 	}
4708 	sbi->s_groups_count = blocks_count;
4709 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4710 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4711 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4712 	    le32_to_cpu(es->s_inodes_count)) {
4713 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4714 			 le32_to_cpu(es->s_inodes_count),
4715 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4716 		return -EINVAL;
4717 	}
4718 
4719 	return 0;
4720 }
4721 
4722 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
4723 {
4724 	struct buffer_head **group_desc;
4725 	int i;
4726 
4727 	rcu_read_lock();
4728 	group_desc = rcu_dereference(sbi->s_group_desc);
4729 	for (i = 0; i < sbi->s_gdb_count; i++)
4730 		brelse(group_desc[i]);
4731 	kvfree(group_desc);
4732 	rcu_read_unlock();
4733 }
4734 
4735 static int ext4_group_desc_init(struct super_block *sb,
4736 				struct ext4_super_block *es,
4737 				ext4_fsblk_t logical_sb_block,
4738 				ext4_group_t *first_not_zeroed)
4739 {
4740 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4741 	unsigned int db_count;
4742 	ext4_fsblk_t block;
4743 	int i;
4744 
4745 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4746 		   EXT4_DESC_PER_BLOCK(sb);
4747 	if (ext4_has_feature_meta_bg(sb)) {
4748 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4749 			ext4_msg(sb, KERN_WARNING,
4750 				 "first meta block group too large: %u "
4751 				 "(group descriptor block count %u)",
4752 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4753 			return -EINVAL;
4754 		}
4755 	}
4756 	rcu_assign_pointer(sbi->s_group_desc,
4757 			   kvmalloc_array(db_count,
4758 					  sizeof(struct buffer_head *),
4759 					  GFP_KERNEL));
4760 	if (sbi->s_group_desc == NULL) {
4761 		ext4_msg(sb, KERN_ERR, "not enough memory");
4762 		return -ENOMEM;
4763 	}
4764 
4765 	bgl_lock_init(sbi->s_blockgroup_lock);
4766 
4767 	/* Pre-read the descriptors into the buffer cache */
4768 	for (i = 0; i < db_count; i++) {
4769 		block = descriptor_loc(sb, logical_sb_block, i);
4770 		ext4_sb_breadahead_unmovable(sb, block);
4771 	}
4772 
4773 	for (i = 0; i < db_count; i++) {
4774 		struct buffer_head *bh;
4775 
4776 		block = descriptor_loc(sb, logical_sb_block, i);
4777 		bh = ext4_sb_bread_unmovable(sb, block);
4778 		if (IS_ERR(bh)) {
4779 			ext4_msg(sb, KERN_ERR,
4780 			       "can't read group descriptor %d", i);
4781 			sbi->s_gdb_count = i;
4782 			return PTR_ERR(bh);
4783 		}
4784 		rcu_read_lock();
4785 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4786 		rcu_read_unlock();
4787 	}
4788 	sbi->s_gdb_count = db_count;
4789 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4790 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4791 		return -EFSCORRUPTED;
4792 	}
4793 
4794 	return 0;
4795 }
4796 
4797 static int ext4_load_and_init_journal(struct super_block *sb,
4798 				      struct ext4_super_block *es,
4799 				      struct ext4_fs_context *ctx)
4800 {
4801 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4802 	int err;
4803 
4804 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4805 	if (err)
4806 		return err;
4807 
4808 	if (ext4_has_feature_64bit(sb) &&
4809 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4810 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4811 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4812 		goto out;
4813 	}
4814 
4815 	if (!set_journal_csum_feature_set(sb)) {
4816 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4817 			 "feature set");
4818 		goto out;
4819 	}
4820 
4821 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4822 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4823 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4824 		ext4_msg(sb, KERN_ERR,
4825 			"Failed to set fast commit journal feature");
4826 		goto out;
4827 	}
4828 
4829 	/* We have now updated the journal if required, so we can
4830 	 * validate the data journaling mode. */
4831 	switch (test_opt(sb, DATA_FLAGS)) {
4832 	case 0:
4833 		/* No mode set, assume a default based on the journal
4834 		 * capabilities: ORDERED_DATA if the journal can
4835 		 * cope, else JOURNAL_DATA
4836 		 */
4837 		if (jbd2_journal_check_available_features
4838 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4839 			set_opt(sb, ORDERED_DATA);
4840 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4841 		} else {
4842 			set_opt(sb, JOURNAL_DATA);
4843 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4844 		}
4845 		break;
4846 
4847 	case EXT4_MOUNT_ORDERED_DATA:
4848 	case EXT4_MOUNT_WRITEBACK_DATA:
4849 		if (!jbd2_journal_check_available_features
4850 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4851 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4852 			       "requested data journaling mode");
4853 			goto out;
4854 		}
4855 		break;
4856 	default:
4857 		break;
4858 	}
4859 
4860 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4861 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4862 		ext4_msg(sb, KERN_ERR, "can't mount with "
4863 			"journal_async_commit in data=ordered mode");
4864 		goto out;
4865 	}
4866 
4867 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4868 
4869 	sbi->s_journal->j_submit_inode_data_buffers =
4870 		ext4_journal_submit_inode_data_buffers;
4871 	sbi->s_journal->j_finish_inode_data_buffers =
4872 		ext4_journal_finish_inode_data_buffers;
4873 
4874 	return 0;
4875 
4876 out:
4877 	/* flush s_error_work before journal destroy. */
4878 	flush_work(&sbi->s_error_work);
4879 	jbd2_journal_destroy(sbi->s_journal);
4880 	sbi->s_journal = NULL;
4881 	return -EINVAL;
4882 }
4883 
4884 static int ext4_journal_data_mode_check(struct super_block *sb)
4885 {
4886 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4887 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4888 			    "data=journal disables delayed allocation, "
4889 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4890 		/* can't mount with both data=journal and dioread_nolock. */
4891 		clear_opt(sb, DIOREAD_NOLOCK);
4892 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4893 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4894 			ext4_msg(sb, KERN_ERR, "can't mount with "
4895 				 "both data=journal and delalloc");
4896 			return -EINVAL;
4897 		}
4898 		if (test_opt(sb, DAX_ALWAYS)) {
4899 			ext4_msg(sb, KERN_ERR, "can't mount with "
4900 				 "both data=journal and dax");
4901 			return -EINVAL;
4902 		}
4903 		if (ext4_has_feature_encrypt(sb)) {
4904 			ext4_msg(sb, KERN_WARNING,
4905 				 "encrypted files will use data=ordered "
4906 				 "instead of data journaling mode");
4907 		}
4908 		if (test_opt(sb, DELALLOC))
4909 			clear_opt(sb, DELALLOC);
4910 	} else {
4911 		sb->s_iflags |= SB_I_CGROUPWB;
4912 	}
4913 
4914 	return 0;
4915 }
4916 
4917 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
4918 			   int silent)
4919 {
4920 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4921 	struct ext4_super_block *es;
4922 	ext4_fsblk_t logical_sb_block;
4923 	unsigned long offset = 0;
4924 	struct buffer_head *bh;
4925 	int ret = -EINVAL;
4926 	int blocksize;
4927 
4928 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4929 	if (!blocksize) {
4930 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4931 		return -EINVAL;
4932 	}
4933 
4934 	/*
4935 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4936 	 * block sizes.  We need to calculate the offset from buffer start.
4937 	 */
4938 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4939 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4940 		offset = do_div(logical_sb_block, blocksize);
4941 	} else {
4942 		logical_sb_block = sbi->s_sb_block;
4943 	}
4944 
4945 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4946 	if (IS_ERR(bh)) {
4947 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4948 		return PTR_ERR(bh);
4949 	}
4950 	/*
4951 	 * Note: s_es must be initialized as soon as possible because
4952 	 *       some ext4 macro-instructions depend on its value
4953 	 */
4954 	es = (struct ext4_super_block *) (bh->b_data + offset);
4955 	sbi->s_es = es;
4956 	sb->s_magic = le16_to_cpu(es->s_magic);
4957 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
4958 		if (!silent)
4959 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4960 		goto out;
4961 	}
4962 
4963 	if (le32_to_cpu(es->s_log_block_size) >
4964 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4965 		ext4_msg(sb, KERN_ERR,
4966 			 "Invalid log block size: %u",
4967 			 le32_to_cpu(es->s_log_block_size));
4968 		goto out;
4969 	}
4970 	if (le32_to_cpu(es->s_log_cluster_size) >
4971 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4972 		ext4_msg(sb, KERN_ERR,
4973 			 "Invalid log cluster size: %u",
4974 			 le32_to_cpu(es->s_log_cluster_size));
4975 		goto out;
4976 	}
4977 
4978 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4979 
4980 	/*
4981 	 * If the default block size is not the same as the real block size,
4982 	 * we need to reload it.
4983 	 */
4984 	if (sb->s_blocksize == blocksize) {
4985 		*lsb = logical_sb_block;
4986 		sbi->s_sbh = bh;
4987 		return 0;
4988 	}
4989 
4990 	/*
4991 	 * bh must be released before kill_bdev(), otherwise
4992 	 * it won't be freed and its page also. kill_bdev()
4993 	 * is called by sb_set_blocksize().
4994 	 */
4995 	brelse(bh);
4996 	/* Validate the filesystem blocksize */
4997 	if (!sb_set_blocksize(sb, blocksize)) {
4998 		ext4_msg(sb, KERN_ERR, "bad block size %d",
4999 				blocksize);
5000 		bh = NULL;
5001 		goto out;
5002 	}
5003 
5004 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5005 	offset = do_div(logical_sb_block, blocksize);
5006 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5007 	if (IS_ERR(bh)) {
5008 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5009 		ret = PTR_ERR(bh);
5010 		bh = NULL;
5011 		goto out;
5012 	}
5013 	es = (struct ext4_super_block *)(bh->b_data + offset);
5014 	sbi->s_es = es;
5015 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5016 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5017 		goto out;
5018 	}
5019 	*lsb = logical_sb_block;
5020 	sbi->s_sbh = bh;
5021 	return 0;
5022 out:
5023 	brelse(bh);
5024 	return ret;
5025 }
5026 
5027 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5028 {
5029 	struct ext4_super_block *es = NULL;
5030 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5031 	struct flex_groups **flex_groups;
5032 	ext4_fsblk_t block;
5033 	ext4_fsblk_t logical_sb_block;
5034 	struct inode *root;
5035 	int ret = -ENOMEM;
5036 	unsigned int i;
5037 	int needs_recovery, has_huge_files;
5038 	int err = 0;
5039 	ext4_group_t first_not_zeroed;
5040 	struct ext4_fs_context *ctx = fc->fs_private;
5041 	int silent = fc->sb_flags & SB_SILENT;
5042 
5043 	/* Set defaults for the variables that will be set during parsing */
5044 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5045 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5046 
5047 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5048 	sbi->s_sectors_written_start =
5049 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5050 
5051 	/* -EINVAL is default */
5052 	ret = -EINVAL;
5053 	err = ext4_load_super(sb, &logical_sb_block, silent);
5054 	if (err)
5055 		goto out_fail;
5056 
5057 	es = sbi->s_es;
5058 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5059 
5060 	err = ext4_init_metadata_csum(sb, es);
5061 	if (err)
5062 		goto failed_mount;
5063 
5064 	ext4_set_def_opts(sb, es);
5065 
5066 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5067 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5068 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5069 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5070 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5071 
5072 	/*
5073 	 * set default s_li_wait_mult for lazyinit, for the case there is
5074 	 * no mount option specified.
5075 	 */
5076 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5077 
5078 	if (ext4_inode_info_init(sb, es))
5079 		goto failed_mount;
5080 
5081 	err = parse_apply_sb_mount_options(sb, ctx);
5082 	if (err < 0)
5083 		goto failed_mount;
5084 
5085 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5086 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5087 
5088 	err = ext4_check_opt_consistency(fc, sb);
5089 	if (err < 0)
5090 		goto failed_mount;
5091 
5092 	ext4_apply_options(fc, sb);
5093 
5094 	if (ext4_encoding_init(sb, es))
5095 		goto failed_mount;
5096 
5097 	if (ext4_journal_data_mode_check(sb))
5098 		goto failed_mount;
5099 
5100 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5101 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5102 
5103 	/* i_version is always enabled now */
5104 	sb->s_flags |= SB_I_VERSION;
5105 
5106 	if (ext4_check_feature_compatibility(sb, es, silent))
5107 		goto failed_mount;
5108 
5109 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
5110 		ext4_msg(sb, KERN_ERR,
5111 			 "Number of reserved GDT blocks insanely large: %d",
5112 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
5113 		goto failed_mount;
5114 	}
5115 
5116 	if (sbi->s_daxdev) {
5117 		if (sb->s_blocksize == PAGE_SIZE)
5118 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
5119 		else
5120 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
5121 	}
5122 
5123 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
5124 		if (ext4_has_feature_inline_data(sb)) {
5125 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
5126 					" that may contain inline data");
5127 			goto failed_mount;
5128 		}
5129 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
5130 			ext4_msg(sb, KERN_ERR,
5131 				"DAX unsupported by block device.");
5132 			goto failed_mount;
5133 		}
5134 	}
5135 
5136 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
5137 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
5138 			 es->s_encryption_level);
5139 		goto failed_mount;
5140 	}
5141 
5142 	has_huge_files = ext4_has_feature_huge_file(sb);
5143 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5144 						      has_huge_files);
5145 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5146 
5147 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5148 	if (ext4_has_feature_64bit(sb)) {
5149 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5150 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5151 		    !is_power_of_2(sbi->s_desc_size)) {
5152 			ext4_msg(sb, KERN_ERR,
5153 			       "unsupported descriptor size %lu",
5154 			       sbi->s_desc_size);
5155 			goto failed_mount;
5156 		}
5157 	} else
5158 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5159 
5160 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5161 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5162 
5163 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5164 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5165 		if (!silent)
5166 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5167 		goto failed_mount;
5168 	}
5169 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5170 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5171 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5172 			 sbi->s_inodes_per_group);
5173 		goto failed_mount;
5174 	}
5175 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5176 					sbi->s_inodes_per_block;
5177 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5178 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5179 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5180 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5181 
5182 	for (i = 0; i < 4; i++)
5183 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5184 	sbi->s_def_hash_version = es->s_def_hash_version;
5185 	if (ext4_has_feature_dir_index(sb)) {
5186 		i = le32_to_cpu(es->s_flags);
5187 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5188 			sbi->s_hash_unsigned = 3;
5189 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5190 #ifdef __CHAR_UNSIGNED__
5191 			if (!sb_rdonly(sb))
5192 				es->s_flags |=
5193 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5194 			sbi->s_hash_unsigned = 3;
5195 #else
5196 			if (!sb_rdonly(sb))
5197 				es->s_flags |=
5198 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5199 #endif
5200 		}
5201 	}
5202 
5203 	if (ext4_handle_clustersize(sb))
5204 		goto failed_mount;
5205 
5206 	/*
5207 	 * Test whether we have more sectors than will fit in sector_t,
5208 	 * and whether the max offset is addressable by the page cache.
5209 	 */
5210 	err = generic_check_addressable(sb->s_blocksize_bits,
5211 					ext4_blocks_count(es));
5212 	if (err) {
5213 		ext4_msg(sb, KERN_ERR, "filesystem"
5214 			 " too large to mount safely on this system");
5215 		goto failed_mount;
5216 	}
5217 
5218 	if (ext4_geometry_check(sb, es))
5219 		goto failed_mount;
5220 
5221 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5222 	spin_lock_init(&sbi->s_error_lock);
5223 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5224 
5225 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5226 	if (err)
5227 		goto failed_mount3;
5228 
5229 	/* Register extent status tree shrinker */
5230 	if (ext4_es_register_shrinker(sbi))
5231 		goto failed_mount3;
5232 
5233 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5234 	sbi->s_extent_max_zeroout_kb = 32;
5235 
5236 	/*
5237 	 * set up enough so that it can read an inode
5238 	 */
5239 	sb->s_op = &ext4_sops;
5240 	sb->s_export_op = &ext4_export_ops;
5241 	sb->s_xattr = ext4_xattr_handlers;
5242 #ifdef CONFIG_FS_ENCRYPTION
5243 	sb->s_cop = &ext4_cryptops;
5244 #endif
5245 #ifdef CONFIG_FS_VERITY
5246 	sb->s_vop = &ext4_verityops;
5247 #endif
5248 #ifdef CONFIG_QUOTA
5249 	sb->dq_op = &ext4_quota_operations;
5250 	if (ext4_has_feature_quota(sb))
5251 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5252 	else
5253 		sb->s_qcop = &ext4_qctl_operations;
5254 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5255 #endif
5256 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5257 
5258 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5259 	mutex_init(&sbi->s_orphan_lock);
5260 
5261 	ext4_fast_commit_init(sb);
5262 
5263 	sb->s_root = NULL;
5264 
5265 	needs_recovery = (es->s_last_orphan != 0 ||
5266 			  ext4_has_feature_orphan_present(sb) ||
5267 			  ext4_has_feature_journal_needs_recovery(sb));
5268 
5269 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5270 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5271 			goto failed_mount3a;
5272 
5273 	/*
5274 	 * The first inode we look at is the journal inode.  Don't try
5275 	 * root first: it may be modified in the journal!
5276 	 */
5277 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5278 		err = ext4_load_and_init_journal(sb, es, ctx);
5279 		if (err)
5280 			goto failed_mount3a;
5281 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5282 		   ext4_has_feature_journal_needs_recovery(sb)) {
5283 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5284 		       "suppressed and not mounted read-only");
5285 		goto failed_mount3a;
5286 	} else {
5287 		/* Nojournal mode, all journal mount options are illegal */
5288 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5289 			ext4_msg(sb, KERN_ERR, "can't mount with "
5290 				 "journal_async_commit, fs mounted w/o journal");
5291 			goto failed_mount3a;
5292 		}
5293 
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 (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5300 			ext4_msg(sb, KERN_ERR, "can't mount with "
5301 				 "commit=%lu, fs mounted w/o journal",
5302 				 sbi->s_commit_interval / HZ);
5303 			goto failed_mount3a;
5304 		}
5305 		if (EXT4_MOUNT_DATA_FLAGS &
5306 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5307 			ext4_msg(sb, KERN_ERR, "can't mount with "
5308 				 "data=, fs mounted w/o journal");
5309 			goto failed_mount3a;
5310 		}
5311 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5312 		clear_opt(sb, JOURNAL_CHECKSUM);
5313 		clear_opt(sb, DATA_FLAGS);
5314 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5315 		sbi->s_journal = NULL;
5316 		needs_recovery = 0;
5317 	}
5318 
5319 	if (!test_opt(sb, NO_MBCACHE)) {
5320 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5321 		if (!sbi->s_ea_block_cache) {
5322 			ext4_msg(sb, KERN_ERR,
5323 				 "Failed to create ea_block_cache");
5324 			goto failed_mount_wq;
5325 		}
5326 
5327 		if (ext4_has_feature_ea_inode(sb)) {
5328 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5329 			if (!sbi->s_ea_inode_cache) {
5330 				ext4_msg(sb, KERN_ERR,
5331 					 "Failed to create ea_inode_cache");
5332 				goto failed_mount_wq;
5333 			}
5334 		}
5335 	}
5336 
5337 	/*
5338 	 * Get the # of file system overhead blocks from the
5339 	 * superblock if present.
5340 	 */
5341 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5342 	/* ignore the precalculated value if it is ridiculous */
5343 	if (sbi->s_overhead > ext4_blocks_count(es))
5344 		sbi->s_overhead = 0;
5345 	/*
5346 	 * If the bigalloc feature is not enabled recalculating the
5347 	 * overhead doesn't take long, so we might as well just redo
5348 	 * it to make sure we are using the correct value.
5349 	 */
5350 	if (!ext4_has_feature_bigalloc(sb))
5351 		sbi->s_overhead = 0;
5352 	if (sbi->s_overhead == 0) {
5353 		err = ext4_calculate_overhead(sb);
5354 		if (err)
5355 			goto failed_mount_wq;
5356 	}
5357 
5358 	/*
5359 	 * The maximum number of concurrent works can be high and
5360 	 * concurrency isn't really necessary.  Limit it to 1.
5361 	 */
5362 	EXT4_SB(sb)->rsv_conversion_wq =
5363 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5364 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5365 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5366 		ret = -ENOMEM;
5367 		goto failed_mount4;
5368 	}
5369 
5370 	/*
5371 	 * The jbd2_journal_load will have done any necessary log recovery,
5372 	 * so we can safely mount the rest of the filesystem now.
5373 	 */
5374 
5375 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5376 	if (IS_ERR(root)) {
5377 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5378 		ret = PTR_ERR(root);
5379 		root = NULL;
5380 		goto failed_mount4;
5381 	}
5382 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5383 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5384 		iput(root);
5385 		goto failed_mount4;
5386 	}
5387 
5388 	sb->s_root = d_make_root(root);
5389 	if (!sb->s_root) {
5390 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5391 		ret = -ENOMEM;
5392 		goto failed_mount4;
5393 	}
5394 
5395 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5396 	if (ret == -EROFS) {
5397 		sb->s_flags |= SB_RDONLY;
5398 		ret = 0;
5399 	} else if (ret)
5400 		goto failed_mount4a;
5401 
5402 	ext4_set_resv_clusters(sb);
5403 
5404 	if (test_opt(sb, BLOCK_VALIDITY)) {
5405 		err = ext4_setup_system_zone(sb);
5406 		if (err) {
5407 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5408 				 "zone (%d)", err);
5409 			goto failed_mount4a;
5410 		}
5411 	}
5412 	ext4_fc_replay_cleanup(sb);
5413 
5414 	ext4_ext_init(sb);
5415 
5416 	/*
5417 	 * Enable optimize_scan if number of groups is > threshold. This can be
5418 	 * turned off by passing "mb_optimize_scan=0". This can also be
5419 	 * turned on forcefully by passing "mb_optimize_scan=1".
5420 	 */
5421 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5422 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5423 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5424 		else
5425 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5426 	}
5427 
5428 	err = ext4_mb_init(sb);
5429 	if (err) {
5430 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5431 			 err);
5432 		goto failed_mount5;
5433 	}
5434 
5435 	/*
5436 	 * We can only set up the journal commit callback once
5437 	 * mballoc is initialized
5438 	 */
5439 	if (sbi->s_journal)
5440 		sbi->s_journal->j_commit_callback =
5441 			ext4_journal_commit_callback;
5442 
5443 	block = ext4_count_free_clusters(sb);
5444 	ext4_free_blocks_count_set(sbi->s_es,
5445 				   EXT4_C2B(sbi, block));
5446 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5447 				  GFP_KERNEL);
5448 	if (!err) {
5449 		unsigned long freei = ext4_count_free_inodes(sb);
5450 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5451 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5452 					  GFP_KERNEL);
5453 	}
5454 	if (!err)
5455 		err = percpu_counter_init(&sbi->s_dirs_counter,
5456 					  ext4_count_dirs(sb), GFP_KERNEL);
5457 	if (!err)
5458 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5459 					  GFP_KERNEL);
5460 	if (!err)
5461 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5462 					  GFP_KERNEL);
5463 	if (!err)
5464 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5465 
5466 	if (err) {
5467 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5468 		goto failed_mount6;
5469 	}
5470 
5471 	if (ext4_has_feature_flex_bg(sb))
5472 		if (!ext4_fill_flex_info(sb)) {
5473 			ext4_msg(sb, KERN_ERR,
5474 			       "unable to initialize "
5475 			       "flex_bg meta info!");
5476 			ret = -ENOMEM;
5477 			goto failed_mount6;
5478 		}
5479 
5480 	err = ext4_register_li_request(sb, first_not_zeroed);
5481 	if (err)
5482 		goto failed_mount6;
5483 
5484 	err = ext4_register_sysfs(sb);
5485 	if (err)
5486 		goto failed_mount7;
5487 
5488 	err = ext4_init_orphan_info(sb);
5489 	if (err)
5490 		goto failed_mount8;
5491 #ifdef CONFIG_QUOTA
5492 	/* Enable quota usage during mount. */
5493 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5494 		err = ext4_enable_quotas(sb);
5495 		if (err)
5496 			goto failed_mount9;
5497 	}
5498 #endif  /* CONFIG_QUOTA */
5499 
5500 	/*
5501 	 * Save the original bdev mapping's wb_err value which could be
5502 	 * used to detect the metadata async write error.
5503 	 */
5504 	spin_lock_init(&sbi->s_bdev_wb_lock);
5505 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5506 				 &sbi->s_bdev_wb_err);
5507 	sb->s_bdev->bd_super = sb;
5508 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5509 	ext4_orphan_cleanup(sb, es);
5510 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5511 	/*
5512 	 * Update the checksum after updating free space/inode counters and
5513 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5514 	 * checksum in the buffer cache until it is written out and
5515 	 * e2fsprogs programs trying to open a file system immediately
5516 	 * after it is mounted can fail.
5517 	 */
5518 	ext4_superblock_csum_set(sb);
5519 	if (needs_recovery) {
5520 		ext4_msg(sb, KERN_INFO, "recovery complete");
5521 		err = ext4_mark_recovery_complete(sb, es);
5522 		if (err)
5523 			goto failed_mount9;
5524 	}
5525 
5526 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5527 		ext4_msg(sb, KERN_WARNING,
5528 			 "mounting with \"discard\" option, but the device does not support discard");
5529 
5530 	if (es->s_error_count)
5531 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5532 
5533 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5534 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5535 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5536 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5537 	atomic_set(&sbi->s_warning_count, 0);
5538 	atomic_set(&sbi->s_msg_count, 0);
5539 
5540 	return 0;
5541 
5542 failed_mount9:
5543 	ext4_release_orphan_info(sb);
5544 failed_mount8:
5545 	ext4_unregister_sysfs(sb);
5546 	kobject_put(&sbi->s_kobj);
5547 failed_mount7:
5548 	ext4_unregister_li_request(sb);
5549 failed_mount6:
5550 	ext4_mb_release(sb);
5551 	rcu_read_lock();
5552 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5553 	if (flex_groups) {
5554 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5555 			kvfree(flex_groups[i]);
5556 		kvfree(flex_groups);
5557 	}
5558 	rcu_read_unlock();
5559 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5560 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5561 	percpu_counter_destroy(&sbi->s_dirs_counter);
5562 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5563 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5564 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5565 failed_mount5:
5566 	ext4_ext_release(sb);
5567 	ext4_release_system_zone(sb);
5568 failed_mount4a:
5569 	dput(sb->s_root);
5570 	sb->s_root = NULL;
5571 failed_mount4:
5572 	ext4_msg(sb, KERN_ERR, "mount failed");
5573 	if (EXT4_SB(sb)->rsv_conversion_wq)
5574 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5575 failed_mount_wq:
5576 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5577 	sbi->s_ea_inode_cache = NULL;
5578 
5579 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5580 	sbi->s_ea_block_cache = NULL;
5581 
5582 	if (sbi->s_journal) {
5583 		/* flush s_error_work before journal destroy. */
5584 		flush_work(&sbi->s_error_work);
5585 		jbd2_journal_destroy(sbi->s_journal);
5586 		sbi->s_journal = NULL;
5587 	}
5588 failed_mount3a:
5589 	ext4_es_unregister_shrinker(sbi);
5590 failed_mount3:
5591 	/* flush s_error_work before sbi destroy */
5592 	flush_work(&sbi->s_error_work);
5593 	del_timer_sync(&sbi->s_err_report);
5594 	ext4_stop_mmpd(sbi);
5595 	ext4_group_desc_free(sbi);
5596 failed_mount:
5597 	if (sbi->s_chksum_driver)
5598 		crypto_free_shash(sbi->s_chksum_driver);
5599 
5600 #if IS_ENABLED(CONFIG_UNICODE)
5601 	utf8_unload(sb->s_encoding);
5602 #endif
5603 
5604 #ifdef CONFIG_QUOTA
5605 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5606 		kfree(get_qf_name(sb, sbi, i));
5607 #endif
5608 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5609 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5610 	brelse(sbi->s_sbh);
5611 	ext4_blkdev_remove(sbi);
5612 out_fail:
5613 	sb->s_fs_info = NULL;
5614 	return err ? err : ret;
5615 }
5616 
5617 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5618 {
5619 	struct ext4_fs_context *ctx = fc->fs_private;
5620 	struct ext4_sb_info *sbi;
5621 	const char *descr;
5622 	int ret;
5623 
5624 	sbi = ext4_alloc_sbi(sb);
5625 	if (!sbi)
5626 		return -ENOMEM;
5627 
5628 	fc->s_fs_info = sbi;
5629 
5630 	/* Cleanup superblock name */
5631 	strreplace(sb->s_id, '/', '!');
5632 
5633 	sbi->s_sb_block = 1;	/* Default super block location */
5634 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5635 		sbi->s_sb_block = ctx->s_sb_block;
5636 
5637 	ret = __ext4_fill_super(fc, sb);
5638 	if (ret < 0)
5639 		goto free_sbi;
5640 
5641 	if (sbi->s_journal) {
5642 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5643 			descr = " journalled data mode";
5644 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5645 			descr = " ordered data mode";
5646 		else
5647 			descr = " writeback data mode";
5648 	} else
5649 		descr = "out journal";
5650 
5651 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5652 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU with%s. "
5653 			 "Quota mode: %s.", &sb->s_uuid, descr,
5654 			 ext4_quota_mode(sb));
5655 
5656 	/* Update the s_overhead_clusters if necessary */
5657 	ext4_update_overhead(sb, false);
5658 	return 0;
5659 
5660 free_sbi:
5661 	ext4_free_sbi(sbi);
5662 	fc->s_fs_info = NULL;
5663 	return ret;
5664 }
5665 
5666 static int ext4_get_tree(struct fs_context *fc)
5667 {
5668 	return get_tree_bdev(fc, ext4_fill_super);
5669 }
5670 
5671 /*
5672  * Setup any per-fs journal parameters now.  We'll do this both on
5673  * initial mount, once the journal has been initialised but before we've
5674  * done any recovery; and again on any subsequent remount.
5675  */
5676 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5677 {
5678 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5679 
5680 	journal->j_commit_interval = sbi->s_commit_interval;
5681 	journal->j_min_batch_time = sbi->s_min_batch_time;
5682 	journal->j_max_batch_time = sbi->s_max_batch_time;
5683 	ext4_fc_init(sb, journal);
5684 
5685 	write_lock(&journal->j_state_lock);
5686 	if (test_opt(sb, BARRIER))
5687 		journal->j_flags |= JBD2_BARRIER;
5688 	else
5689 		journal->j_flags &= ~JBD2_BARRIER;
5690 	if (test_opt(sb, DATA_ERR_ABORT))
5691 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5692 	else
5693 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5694 	write_unlock(&journal->j_state_lock);
5695 }
5696 
5697 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5698 					     unsigned int journal_inum)
5699 {
5700 	struct inode *journal_inode;
5701 
5702 	/*
5703 	 * Test for the existence of a valid inode on disk.  Bad things
5704 	 * happen if we iget() an unused inode, as the subsequent iput()
5705 	 * will try to delete it.
5706 	 */
5707 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5708 	if (IS_ERR(journal_inode)) {
5709 		ext4_msg(sb, KERN_ERR, "no journal found");
5710 		return NULL;
5711 	}
5712 	if (!journal_inode->i_nlink) {
5713 		make_bad_inode(journal_inode);
5714 		iput(journal_inode);
5715 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5716 		return NULL;
5717 	}
5718 
5719 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5720 		  journal_inode, journal_inode->i_size);
5721 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5722 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5723 		iput(journal_inode);
5724 		return NULL;
5725 	}
5726 	return journal_inode;
5727 }
5728 
5729 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5730 {
5731 	struct ext4_map_blocks map;
5732 	int ret;
5733 
5734 	if (journal->j_inode == NULL)
5735 		return 0;
5736 
5737 	map.m_lblk = *block;
5738 	map.m_len = 1;
5739 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5740 	if (ret <= 0) {
5741 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5742 			 "journal bmap failed: block %llu ret %d\n",
5743 			 *block, ret);
5744 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5745 		return ret;
5746 	}
5747 	*block = map.m_pblk;
5748 	return 0;
5749 }
5750 
5751 static journal_t *ext4_get_journal(struct super_block *sb,
5752 				   unsigned int journal_inum)
5753 {
5754 	struct inode *journal_inode;
5755 	journal_t *journal;
5756 
5757 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5758 		return NULL;
5759 
5760 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5761 	if (!journal_inode)
5762 		return NULL;
5763 
5764 	journal = jbd2_journal_init_inode(journal_inode);
5765 	if (!journal) {
5766 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5767 		iput(journal_inode);
5768 		return NULL;
5769 	}
5770 	journal->j_private = sb;
5771 	journal->j_bmap = ext4_journal_bmap;
5772 	ext4_init_journal_params(sb, journal);
5773 	return journal;
5774 }
5775 
5776 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5777 				       dev_t j_dev)
5778 {
5779 	struct buffer_head *bh;
5780 	journal_t *journal;
5781 	ext4_fsblk_t start;
5782 	ext4_fsblk_t len;
5783 	int hblock, blocksize;
5784 	ext4_fsblk_t sb_block;
5785 	unsigned long offset;
5786 	struct ext4_super_block *es;
5787 	struct block_device *bdev;
5788 
5789 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5790 		return NULL;
5791 
5792 	bdev = ext4_blkdev_get(j_dev, sb);
5793 	if (bdev == NULL)
5794 		return NULL;
5795 
5796 	blocksize = sb->s_blocksize;
5797 	hblock = bdev_logical_block_size(bdev);
5798 	if (blocksize < hblock) {
5799 		ext4_msg(sb, KERN_ERR,
5800 			"blocksize too small for journal device");
5801 		goto out_bdev;
5802 	}
5803 
5804 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5805 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5806 	set_blocksize(bdev, blocksize);
5807 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5808 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5809 		       "external journal");
5810 		goto out_bdev;
5811 	}
5812 
5813 	es = (struct ext4_super_block *) (bh->b_data + offset);
5814 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5815 	    !(le32_to_cpu(es->s_feature_incompat) &
5816 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5817 		ext4_msg(sb, KERN_ERR, "external journal has "
5818 					"bad superblock");
5819 		brelse(bh);
5820 		goto out_bdev;
5821 	}
5822 
5823 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5824 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5825 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5826 		ext4_msg(sb, KERN_ERR, "external journal has "
5827 				       "corrupt superblock");
5828 		brelse(bh);
5829 		goto out_bdev;
5830 	}
5831 
5832 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5833 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5834 		brelse(bh);
5835 		goto out_bdev;
5836 	}
5837 
5838 	len = ext4_blocks_count(es);
5839 	start = sb_block + 1;
5840 	brelse(bh);	/* we're done with the superblock */
5841 
5842 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5843 					start, len, blocksize);
5844 	if (!journal) {
5845 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5846 		goto out_bdev;
5847 	}
5848 	journal->j_private = sb;
5849 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5850 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5851 		goto out_journal;
5852 	}
5853 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5854 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5855 					"user (unsupported) - %d",
5856 			be32_to_cpu(journal->j_superblock->s_nr_users));
5857 		goto out_journal;
5858 	}
5859 	EXT4_SB(sb)->s_journal_bdev = bdev;
5860 	ext4_init_journal_params(sb, journal);
5861 	return journal;
5862 
5863 out_journal:
5864 	jbd2_journal_destroy(journal);
5865 out_bdev:
5866 	ext4_blkdev_put(bdev);
5867 	return NULL;
5868 }
5869 
5870 static int ext4_load_journal(struct super_block *sb,
5871 			     struct ext4_super_block *es,
5872 			     unsigned long journal_devnum)
5873 {
5874 	journal_t *journal;
5875 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5876 	dev_t journal_dev;
5877 	int err = 0;
5878 	int really_read_only;
5879 	int journal_dev_ro;
5880 
5881 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5882 		return -EFSCORRUPTED;
5883 
5884 	if (journal_devnum &&
5885 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5886 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5887 			"numbers have changed");
5888 		journal_dev = new_decode_dev(journal_devnum);
5889 	} else
5890 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5891 
5892 	if (journal_inum && journal_dev) {
5893 		ext4_msg(sb, KERN_ERR,
5894 			 "filesystem has both journal inode and journal device!");
5895 		return -EINVAL;
5896 	}
5897 
5898 	if (journal_inum) {
5899 		journal = ext4_get_journal(sb, journal_inum);
5900 		if (!journal)
5901 			return -EINVAL;
5902 	} else {
5903 		journal = ext4_get_dev_journal(sb, journal_dev);
5904 		if (!journal)
5905 			return -EINVAL;
5906 	}
5907 
5908 	journal_dev_ro = bdev_read_only(journal->j_dev);
5909 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5910 
5911 	if (journal_dev_ro && !sb_rdonly(sb)) {
5912 		ext4_msg(sb, KERN_ERR,
5913 			 "journal device read-only, try mounting with '-o ro'");
5914 		err = -EROFS;
5915 		goto err_out;
5916 	}
5917 
5918 	/*
5919 	 * Are we loading a blank journal or performing recovery after a
5920 	 * crash?  For recovery, we need to check in advance whether we
5921 	 * can get read-write access to the device.
5922 	 */
5923 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5924 		if (sb_rdonly(sb)) {
5925 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5926 					"required on readonly filesystem");
5927 			if (really_read_only) {
5928 				ext4_msg(sb, KERN_ERR, "write access "
5929 					"unavailable, cannot proceed "
5930 					"(try mounting with noload)");
5931 				err = -EROFS;
5932 				goto err_out;
5933 			}
5934 			ext4_msg(sb, KERN_INFO, "write access will "
5935 			       "be enabled during recovery");
5936 		}
5937 	}
5938 
5939 	if (!(journal->j_flags & JBD2_BARRIER))
5940 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5941 
5942 	if (!ext4_has_feature_journal_needs_recovery(sb))
5943 		err = jbd2_journal_wipe(journal, !really_read_only);
5944 	if (!err) {
5945 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5946 
5947 		if (save)
5948 			memcpy(save, ((char *) es) +
5949 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5950 		err = jbd2_journal_load(journal);
5951 		if (save)
5952 			memcpy(((char *) es) + EXT4_S_ERR_START,
5953 			       save, EXT4_S_ERR_LEN);
5954 		kfree(save);
5955 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
5956 					   EXT4_ERROR_FS);
5957 		/* Write out restored error information to the superblock */
5958 		if (!bdev_read_only(sb->s_bdev)) {
5959 			int err2;
5960 			err2 = ext4_commit_super(sb);
5961 			err = err ? : err2;
5962 		}
5963 	}
5964 
5965 	if (err) {
5966 		ext4_msg(sb, KERN_ERR, "error loading journal");
5967 		goto err_out;
5968 	}
5969 
5970 	EXT4_SB(sb)->s_journal = journal;
5971 	err = ext4_clear_journal_err(sb, es);
5972 	if (err) {
5973 		EXT4_SB(sb)->s_journal = NULL;
5974 		jbd2_journal_destroy(journal);
5975 		return err;
5976 	}
5977 
5978 	if (!really_read_only && journal_devnum &&
5979 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5980 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5981 		ext4_commit_super(sb);
5982 	}
5983 	if (!really_read_only && journal_inum &&
5984 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
5985 		es->s_journal_inum = cpu_to_le32(journal_inum);
5986 		ext4_commit_super(sb);
5987 	}
5988 
5989 	return 0;
5990 
5991 err_out:
5992 	jbd2_journal_destroy(journal);
5993 	return err;
5994 }
5995 
5996 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5997 static void ext4_update_super(struct super_block *sb)
5998 {
5999 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6000 	struct ext4_super_block *es = sbi->s_es;
6001 	struct buffer_head *sbh = sbi->s_sbh;
6002 
6003 	lock_buffer(sbh);
6004 	/*
6005 	 * If the file system is mounted read-only, don't update the
6006 	 * superblock write time.  This avoids updating the superblock
6007 	 * write time when we are mounting the root file system
6008 	 * read/only but we need to replay the journal; at that point,
6009 	 * for people who are east of GMT and who make their clock
6010 	 * tick in localtime for Windows bug-for-bug compatibility,
6011 	 * the clock is set in the future, and this will cause e2fsck
6012 	 * to complain and force a full file system check.
6013 	 */
6014 	if (!(sb->s_flags & SB_RDONLY))
6015 		ext4_update_tstamp(es, s_wtime);
6016 	es->s_kbytes_written =
6017 		cpu_to_le64(sbi->s_kbytes_written +
6018 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6019 		      sbi->s_sectors_written_start) >> 1));
6020 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6021 		ext4_free_blocks_count_set(es,
6022 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6023 				&sbi->s_freeclusters_counter)));
6024 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6025 		es->s_free_inodes_count =
6026 			cpu_to_le32(percpu_counter_sum_positive(
6027 				&sbi->s_freeinodes_counter));
6028 	/* Copy error information to the on-disk superblock */
6029 	spin_lock(&sbi->s_error_lock);
6030 	if (sbi->s_add_error_count > 0) {
6031 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6032 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6033 			__ext4_update_tstamp(&es->s_first_error_time,
6034 					     &es->s_first_error_time_hi,
6035 					     sbi->s_first_error_time);
6036 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6037 				sizeof(es->s_first_error_func));
6038 			es->s_first_error_line =
6039 				cpu_to_le32(sbi->s_first_error_line);
6040 			es->s_first_error_ino =
6041 				cpu_to_le32(sbi->s_first_error_ino);
6042 			es->s_first_error_block =
6043 				cpu_to_le64(sbi->s_first_error_block);
6044 			es->s_first_error_errcode =
6045 				ext4_errno_to_code(sbi->s_first_error_code);
6046 		}
6047 		__ext4_update_tstamp(&es->s_last_error_time,
6048 				     &es->s_last_error_time_hi,
6049 				     sbi->s_last_error_time);
6050 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6051 			sizeof(es->s_last_error_func));
6052 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6053 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6054 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6055 		es->s_last_error_errcode =
6056 				ext4_errno_to_code(sbi->s_last_error_code);
6057 		/*
6058 		 * Start the daily error reporting function if it hasn't been
6059 		 * started already
6060 		 */
6061 		if (!es->s_error_count)
6062 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6063 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6064 		sbi->s_add_error_count = 0;
6065 	}
6066 	spin_unlock(&sbi->s_error_lock);
6067 
6068 	ext4_superblock_csum_set(sb);
6069 	unlock_buffer(sbh);
6070 }
6071 
6072 static int ext4_commit_super(struct super_block *sb)
6073 {
6074 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6075 
6076 	if (!sbh)
6077 		return -EINVAL;
6078 	if (block_device_ejected(sb))
6079 		return -ENODEV;
6080 
6081 	ext4_update_super(sb);
6082 
6083 	lock_buffer(sbh);
6084 	/* Buffer got discarded which means block device got invalidated */
6085 	if (!buffer_mapped(sbh)) {
6086 		unlock_buffer(sbh);
6087 		return -EIO;
6088 	}
6089 
6090 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6091 		/*
6092 		 * Oh, dear.  A previous attempt to write the
6093 		 * superblock failed.  This could happen because the
6094 		 * USB device was yanked out.  Or it could happen to
6095 		 * be a transient write error and maybe the block will
6096 		 * be remapped.  Nothing we can do but to retry the
6097 		 * write and hope for the best.
6098 		 */
6099 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6100 		       "superblock detected");
6101 		clear_buffer_write_io_error(sbh);
6102 		set_buffer_uptodate(sbh);
6103 	}
6104 	get_bh(sbh);
6105 	/* Clear potential dirty bit if it was journalled update */
6106 	clear_buffer_dirty(sbh);
6107 	sbh->b_end_io = end_buffer_write_sync;
6108 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6109 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6110 	wait_on_buffer(sbh);
6111 	if (buffer_write_io_error(sbh)) {
6112 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6113 		       "superblock");
6114 		clear_buffer_write_io_error(sbh);
6115 		set_buffer_uptodate(sbh);
6116 		return -EIO;
6117 	}
6118 	return 0;
6119 }
6120 
6121 /*
6122  * Have we just finished recovery?  If so, and if we are mounting (or
6123  * remounting) the filesystem readonly, then we will end up with a
6124  * consistent fs on disk.  Record that fact.
6125  */
6126 static int ext4_mark_recovery_complete(struct super_block *sb,
6127 				       struct ext4_super_block *es)
6128 {
6129 	int err;
6130 	journal_t *journal = EXT4_SB(sb)->s_journal;
6131 
6132 	if (!ext4_has_feature_journal(sb)) {
6133 		if (journal != NULL) {
6134 			ext4_error(sb, "Journal got removed while the fs was "
6135 				   "mounted!");
6136 			return -EFSCORRUPTED;
6137 		}
6138 		return 0;
6139 	}
6140 	jbd2_journal_lock_updates(journal);
6141 	err = jbd2_journal_flush(journal, 0);
6142 	if (err < 0)
6143 		goto out;
6144 
6145 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6146 	    ext4_has_feature_orphan_present(sb))) {
6147 		if (!ext4_orphan_file_empty(sb)) {
6148 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6149 			err = -EFSCORRUPTED;
6150 			goto out;
6151 		}
6152 		ext4_clear_feature_journal_needs_recovery(sb);
6153 		ext4_clear_feature_orphan_present(sb);
6154 		ext4_commit_super(sb);
6155 	}
6156 out:
6157 	jbd2_journal_unlock_updates(journal);
6158 	return err;
6159 }
6160 
6161 /*
6162  * If we are mounting (or read-write remounting) a filesystem whose journal
6163  * has recorded an error from a previous lifetime, move that error to the
6164  * main filesystem now.
6165  */
6166 static int ext4_clear_journal_err(struct super_block *sb,
6167 				   struct ext4_super_block *es)
6168 {
6169 	journal_t *journal;
6170 	int j_errno;
6171 	const char *errstr;
6172 
6173 	if (!ext4_has_feature_journal(sb)) {
6174 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6175 		return -EFSCORRUPTED;
6176 	}
6177 
6178 	journal = EXT4_SB(sb)->s_journal;
6179 
6180 	/*
6181 	 * Now check for any error status which may have been recorded in the
6182 	 * journal by a prior ext4_error() or ext4_abort()
6183 	 */
6184 
6185 	j_errno = jbd2_journal_errno(journal);
6186 	if (j_errno) {
6187 		char nbuf[16];
6188 
6189 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6190 		ext4_warning(sb, "Filesystem error recorded "
6191 			     "from previous mount: %s", errstr);
6192 
6193 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6194 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6195 		j_errno = ext4_commit_super(sb);
6196 		if (j_errno)
6197 			return j_errno;
6198 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6199 
6200 		jbd2_journal_clear_err(journal);
6201 		jbd2_journal_update_sb_errno(journal);
6202 	}
6203 	return 0;
6204 }
6205 
6206 /*
6207  * Force the running and committing transactions to commit,
6208  * and wait on the commit.
6209  */
6210 int ext4_force_commit(struct super_block *sb)
6211 {
6212 	journal_t *journal;
6213 
6214 	if (sb_rdonly(sb))
6215 		return 0;
6216 
6217 	journal = EXT4_SB(sb)->s_journal;
6218 	return ext4_journal_force_commit(journal);
6219 }
6220 
6221 static int ext4_sync_fs(struct super_block *sb, int wait)
6222 {
6223 	int ret = 0;
6224 	tid_t target;
6225 	bool needs_barrier = false;
6226 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6227 
6228 	if (unlikely(ext4_forced_shutdown(sbi)))
6229 		return 0;
6230 
6231 	trace_ext4_sync_fs(sb, wait);
6232 	flush_workqueue(sbi->rsv_conversion_wq);
6233 	/*
6234 	 * Writeback quota in non-journalled quota case - journalled quota has
6235 	 * no dirty dquots
6236 	 */
6237 	dquot_writeback_dquots(sb, -1);
6238 	/*
6239 	 * Data writeback is possible w/o journal transaction, so barrier must
6240 	 * being sent at the end of the function. But we can skip it if
6241 	 * transaction_commit will do it for us.
6242 	 */
6243 	if (sbi->s_journal) {
6244 		target = jbd2_get_latest_transaction(sbi->s_journal);
6245 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6246 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6247 			needs_barrier = true;
6248 
6249 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6250 			if (wait)
6251 				ret = jbd2_log_wait_commit(sbi->s_journal,
6252 							   target);
6253 		}
6254 	} else if (wait && test_opt(sb, BARRIER))
6255 		needs_barrier = true;
6256 	if (needs_barrier) {
6257 		int err;
6258 		err = blkdev_issue_flush(sb->s_bdev);
6259 		if (!ret)
6260 			ret = err;
6261 	}
6262 
6263 	return ret;
6264 }
6265 
6266 /*
6267  * LVM calls this function before a (read-only) snapshot is created.  This
6268  * gives us a chance to flush the journal completely and mark the fs clean.
6269  *
6270  * Note that only this function cannot bring a filesystem to be in a clean
6271  * state independently. It relies on upper layer to stop all data & metadata
6272  * modifications.
6273  */
6274 static int ext4_freeze(struct super_block *sb)
6275 {
6276 	int error = 0;
6277 	journal_t *journal;
6278 
6279 	if (sb_rdonly(sb))
6280 		return 0;
6281 
6282 	journal = EXT4_SB(sb)->s_journal;
6283 
6284 	if (journal) {
6285 		/* Now we set up the journal barrier. */
6286 		jbd2_journal_lock_updates(journal);
6287 
6288 		/*
6289 		 * Don't clear the needs_recovery flag if we failed to
6290 		 * flush the journal.
6291 		 */
6292 		error = jbd2_journal_flush(journal, 0);
6293 		if (error < 0)
6294 			goto out;
6295 
6296 		/* Journal blocked and flushed, clear needs_recovery flag. */
6297 		ext4_clear_feature_journal_needs_recovery(sb);
6298 		if (ext4_orphan_file_empty(sb))
6299 			ext4_clear_feature_orphan_present(sb);
6300 	}
6301 
6302 	error = ext4_commit_super(sb);
6303 out:
6304 	if (journal)
6305 		/* we rely on upper layer to stop further updates */
6306 		jbd2_journal_unlock_updates(journal);
6307 	return error;
6308 }
6309 
6310 /*
6311  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6312  * flag here, even though the filesystem is not technically dirty yet.
6313  */
6314 static int ext4_unfreeze(struct super_block *sb)
6315 {
6316 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6317 		return 0;
6318 
6319 	if (EXT4_SB(sb)->s_journal) {
6320 		/* Reset the needs_recovery flag before the fs is unlocked. */
6321 		ext4_set_feature_journal_needs_recovery(sb);
6322 		if (ext4_has_feature_orphan_file(sb))
6323 			ext4_set_feature_orphan_present(sb);
6324 	}
6325 
6326 	ext4_commit_super(sb);
6327 	return 0;
6328 }
6329 
6330 /*
6331  * Structure to save mount options for ext4_remount's benefit
6332  */
6333 struct ext4_mount_options {
6334 	unsigned long s_mount_opt;
6335 	unsigned long s_mount_opt2;
6336 	kuid_t s_resuid;
6337 	kgid_t s_resgid;
6338 	unsigned long s_commit_interval;
6339 	u32 s_min_batch_time, s_max_batch_time;
6340 #ifdef CONFIG_QUOTA
6341 	int s_jquota_fmt;
6342 	char *s_qf_names[EXT4_MAXQUOTAS];
6343 #endif
6344 };
6345 
6346 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6347 {
6348 	struct ext4_fs_context *ctx = fc->fs_private;
6349 	struct ext4_super_block *es;
6350 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6351 	unsigned long old_sb_flags;
6352 	struct ext4_mount_options old_opts;
6353 	ext4_group_t g;
6354 	int err = 0;
6355 #ifdef CONFIG_QUOTA
6356 	int enable_quota = 0;
6357 	int i, j;
6358 	char *to_free[EXT4_MAXQUOTAS];
6359 #endif
6360 
6361 
6362 	/* Store the original options */
6363 	old_sb_flags = sb->s_flags;
6364 	old_opts.s_mount_opt = sbi->s_mount_opt;
6365 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6366 	old_opts.s_resuid = sbi->s_resuid;
6367 	old_opts.s_resgid = sbi->s_resgid;
6368 	old_opts.s_commit_interval = sbi->s_commit_interval;
6369 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6370 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6371 #ifdef CONFIG_QUOTA
6372 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6373 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6374 		if (sbi->s_qf_names[i]) {
6375 			char *qf_name = get_qf_name(sb, sbi, i);
6376 
6377 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6378 			if (!old_opts.s_qf_names[i]) {
6379 				for (j = 0; j < i; j++)
6380 					kfree(old_opts.s_qf_names[j]);
6381 				return -ENOMEM;
6382 			}
6383 		} else
6384 			old_opts.s_qf_names[i] = NULL;
6385 #endif
6386 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6387 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6388 			ctx->journal_ioprio =
6389 				sbi->s_journal->j_task->io_context->ioprio;
6390 		else
6391 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6392 
6393 	}
6394 
6395 	ext4_apply_options(fc, sb);
6396 
6397 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6398 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6399 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6400 			 "during remount not supported; ignoring");
6401 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6402 	}
6403 
6404 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6405 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6406 			ext4_msg(sb, KERN_ERR, "can't mount with "
6407 				 "both data=journal and delalloc");
6408 			err = -EINVAL;
6409 			goto restore_opts;
6410 		}
6411 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6412 			ext4_msg(sb, KERN_ERR, "can't mount with "
6413 				 "both data=journal and dioread_nolock");
6414 			err = -EINVAL;
6415 			goto restore_opts;
6416 		}
6417 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6418 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6419 			ext4_msg(sb, KERN_ERR, "can't mount with "
6420 				"journal_async_commit in data=ordered mode");
6421 			err = -EINVAL;
6422 			goto restore_opts;
6423 		}
6424 	}
6425 
6426 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6427 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6428 		err = -EINVAL;
6429 		goto restore_opts;
6430 	}
6431 
6432 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6433 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6434 
6435 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6436 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6437 
6438 	es = sbi->s_es;
6439 
6440 	if (sbi->s_journal) {
6441 		ext4_init_journal_params(sb, sbi->s_journal);
6442 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6443 	}
6444 
6445 	/* Flush outstanding errors before changing fs state */
6446 	flush_work(&sbi->s_error_work);
6447 
6448 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6449 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6450 			err = -EROFS;
6451 			goto restore_opts;
6452 		}
6453 
6454 		if (fc->sb_flags & SB_RDONLY) {
6455 			err = sync_filesystem(sb);
6456 			if (err < 0)
6457 				goto restore_opts;
6458 			err = dquot_suspend(sb, -1);
6459 			if (err < 0)
6460 				goto restore_opts;
6461 
6462 			/*
6463 			 * First of all, the unconditional stuff we have to do
6464 			 * to disable replay of the journal when we next remount
6465 			 */
6466 			sb->s_flags |= SB_RDONLY;
6467 
6468 			/*
6469 			 * OK, test if we are remounting a valid rw partition
6470 			 * readonly, and if so set the rdonly flag and then
6471 			 * mark the partition as valid again.
6472 			 */
6473 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6474 			    (sbi->s_mount_state & EXT4_VALID_FS))
6475 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6476 
6477 			if (sbi->s_journal) {
6478 				/*
6479 				 * We let remount-ro finish even if marking fs
6480 				 * as clean failed...
6481 				 */
6482 				ext4_mark_recovery_complete(sb, es);
6483 			}
6484 		} else {
6485 			/* Make sure we can mount this feature set readwrite */
6486 			if (ext4_has_feature_readonly(sb) ||
6487 			    !ext4_feature_set_ok(sb, 0)) {
6488 				err = -EROFS;
6489 				goto restore_opts;
6490 			}
6491 			/*
6492 			 * Make sure the group descriptor checksums
6493 			 * are sane.  If they aren't, refuse to remount r/w.
6494 			 */
6495 			for (g = 0; g < sbi->s_groups_count; g++) {
6496 				struct ext4_group_desc *gdp =
6497 					ext4_get_group_desc(sb, g, NULL);
6498 
6499 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6500 					ext4_msg(sb, KERN_ERR,
6501 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6502 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6503 					       le16_to_cpu(gdp->bg_checksum));
6504 					err = -EFSBADCRC;
6505 					goto restore_opts;
6506 				}
6507 			}
6508 
6509 			/*
6510 			 * If we have an unprocessed orphan list hanging
6511 			 * around from a previously readonly bdev mount,
6512 			 * require a full umount/remount for now.
6513 			 */
6514 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6515 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6516 				       "remount RDWR because of unprocessed "
6517 				       "orphan inode list.  Please "
6518 				       "umount/remount instead");
6519 				err = -EINVAL;
6520 				goto restore_opts;
6521 			}
6522 
6523 			/*
6524 			 * Mounting a RDONLY partition read-write, so reread
6525 			 * and store the current valid flag.  (It may have
6526 			 * been changed by e2fsck since we originally mounted
6527 			 * the partition.)
6528 			 */
6529 			if (sbi->s_journal) {
6530 				err = ext4_clear_journal_err(sb, es);
6531 				if (err)
6532 					goto restore_opts;
6533 			}
6534 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6535 					      ~EXT4_FC_REPLAY);
6536 
6537 			err = ext4_setup_super(sb, es, 0);
6538 			if (err)
6539 				goto restore_opts;
6540 
6541 			sb->s_flags &= ~SB_RDONLY;
6542 			if (ext4_has_feature_mmp(sb))
6543 				if (ext4_multi_mount_protect(sb,
6544 						le64_to_cpu(es->s_mmp_block))) {
6545 					err = -EROFS;
6546 					goto restore_opts;
6547 				}
6548 #ifdef CONFIG_QUOTA
6549 			enable_quota = 1;
6550 #endif
6551 		}
6552 	}
6553 
6554 	/*
6555 	 * Reinitialize lazy itable initialization thread based on
6556 	 * current settings
6557 	 */
6558 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6559 		ext4_unregister_li_request(sb);
6560 	else {
6561 		ext4_group_t first_not_zeroed;
6562 		first_not_zeroed = ext4_has_uninit_itable(sb);
6563 		ext4_register_li_request(sb, first_not_zeroed);
6564 	}
6565 
6566 	/*
6567 	 * Handle creation of system zone data early because it can fail.
6568 	 * Releasing of existing data is done when we are sure remount will
6569 	 * succeed.
6570 	 */
6571 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6572 		err = ext4_setup_system_zone(sb);
6573 		if (err)
6574 			goto restore_opts;
6575 	}
6576 
6577 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6578 		err = ext4_commit_super(sb);
6579 		if (err)
6580 			goto restore_opts;
6581 	}
6582 
6583 #ifdef CONFIG_QUOTA
6584 	/* Release old quota file names */
6585 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6586 		kfree(old_opts.s_qf_names[i]);
6587 	if (enable_quota) {
6588 		if (sb_any_quota_suspended(sb))
6589 			dquot_resume(sb, -1);
6590 		else if (ext4_has_feature_quota(sb)) {
6591 			err = ext4_enable_quotas(sb);
6592 			if (err)
6593 				goto restore_opts;
6594 		}
6595 	}
6596 #endif
6597 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6598 		ext4_release_system_zone(sb);
6599 
6600 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6601 		ext4_stop_mmpd(sbi);
6602 
6603 	return 0;
6604 
6605 restore_opts:
6606 	sb->s_flags = old_sb_flags;
6607 	sbi->s_mount_opt = old_opts.s_mount_opt;
6608 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6609 	sbi->s_resuid = old_opts.s_resuid;
6610 	sbi->s_resgid = old_opts.s_resgid;
6611 	sbi->s_commit_interval = old_opts.s_commit_interval;
6612 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6613 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6614 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6615 		ext4_release_system_zone(sb);
6616 #ifdef CONFIG_QUOTA
6617 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6618 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6619 		to_free[i] = get_qf_name(sb, sbi, i);
6620 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6621 	}
6622 	synchronize_rcu();
6623 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6624 		kfree(to_free[i]);
6625 #endif
6626 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6627 		ext4_stop_mmpd(sbi);
6628 	return err;
6629 }
6630 
6631 static int ext4_reconfigure(struct fs_context *fc)
6632 {
6633 	struct super_block *sb = fc->root->d_sb;
6634 	int ret;
6635 
6636 	fc->s_fs_info = EXT4_SB(sb);
6637 
6638 	ret = ext4_check_opt_consistency(fc, sb);
6639 	if (ret < 0)
6640 		return ret;
6641 
6642 	ret = __ext4_remount(fc, sb);
6643 	if (ret < 0)
6644 		return ret;
6645 
6646 	ext4_msg(sb, KERN_INFO, "re-mounted %pU. Quota mode: %s.",
6647 		 &sb->s_uuid, ext4_quota_mode(sb));
6648 
6649 	return 0;
6650 }
6651 
6652 #ifdef CONFIG_QUOTA
6653 static int ext4_statfs_project(struct super_block *sb,
6654 			       kprojid_t projid, struct kstatfs *buf)
6655 {
6656 	struct kqid qid;
6657 	struct dquot *dquot;
6658 	u64 limit;
6659 	u64 curblock;
6660 
6661 	qid = make_kqid_projid(projid);
6662 	dquot = dqget(sb, qid);
6663 	if (IS_ERR(dquot))
6664 		return PTR_ERR(dquot);
6665 	spin_lock(&dquot->dq_dqb_lock);
6666 
6667 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6668 			     dquot->dq_dqb.dqb_bhardlimit);
6669 	limit >>= sb->s_blocksize_bits;
6670 
6671 	if (limit && buf->f_blocks > limit) {
6672 		curblock = (dquot->dq_dqb.dqb_curspace +
6673 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6674 		buf->f_blocks = limit;
6675 		buf->f_bfree = buf->f_bavail =
6676 			(buf->f_blocks > curblock) ?
6677 			 (buf->f_blocks - curblock) : 0;
6678 	}
6679 
6680 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6681 			     dquot->dq_dqb.dqb_ihardlimit);
6682 	if (limit && buf->f_files > limit) {
6683 		buf->f_files = limit;
6684 		buf->f_ffree =
6685 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6686 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6687 	}
6688 
6689 	spin_unlock(&dquot->dq_dqb_lock);
6690 	dqput(dquot);
6691 	return 0;
6692 }
6693 #endif
6694 
6695 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6696 {
6697 	struct super_block *sb = dentry->d_sb;
6698 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6699 	struct ext4_super_block *es = sbi->s_es;
6700 	ext4_fsblk_t overhead = 0, resv_blocks;
6701 	s64 bfree;
6702 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6703 
6704 	if (!test_opt(sb, MINIX_DF))
6705 		overhead = sbi->s_overhead;
6706 
6707 	buf->f_type = EXT4_SUPER_MAGIC;
6708 	buf->f_bsize = sb->s_blocksize;
6709 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6710 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6711 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6712 	/* prevent underflow in case that few free space is available */
6713 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6714 	buf->f_bavail = buf->f_bfree -
6715 			(ext4_r_blocks_count(es) + resv_blocks);
6716 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6717 		buf->f_bavail = 0;
6718 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6719 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6720 	buf->f_namelen = EXT4_NAME_LEN;
6721 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6722 
6723 #ifdef CONFIG_QUOTA
6724 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6725 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6726 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6727 #endif
6728 	return 0;
6729 }
6730 
6731 
6732 #ifdef CONFIG_QUOTA
6733 
6734 /*
6735  * Helper functions so that transaction is started before we acquire dqio_sem
6736  * to keep correct lock ordering of transaction > dqio_sem
6737  */
6738 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6739 {
6740 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6741 }
6742 
6743 static int ext4_write_dquot(struct dquot *dquot)
6744 {
6745 	int ret, err;
6746 	handle_t *handle;
6747 	struct inode *inode;
6748 
6749 	inode = dquot_to_inode(dquot);
6750 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6751 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6752 	if (IS_ERR(handle))
6753 		return PTR_ERR(handle);
6754 	ret = dquot_commit(dquot);
6755 	err = ext4_journal_stop(handle);
6756 	if (!ret)
6757 		ret = err;
6758 	return ret;
6759 }
6760 
6761 static int ext4_acquire_dquot(struct dquot *dquot)
6762 {
6763 	int ret, err;
6764 	handle_t *handle;
6765 
6766 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6767 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6768 	if (IS_ERR(handle))
6769 		return PTR_ERR(handle);
6770 	ret = dquot_acquire(dquot);
6771 	err = ext4_journal_stop(handle);
6772 	if (!ret)
6773 		ret = err;
6774 	return ret;
6775 }
6776 
6777 static int ext4_release_dquot(struct dquot *dquot)
6778 {
6779 	int ret, err;
6780 	handle_t *handle;
6781 
6782 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6783 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6784 	if (IS_ERR(handle)) {
6785 		/* Release dquot anyway to avoid endless cycle in dqput() */
6786 		dquot_release(dquot);
6787 		return PTR_ERR(handle);
6788 	}
6789 	ret = dquot_release(dquot);
6790 	err = ext4_journal_stop(handle);
6791 	if (!ret)
6792 		ret = err;
6793 	return ret;
6794 }
6795 
6796 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6797 {
6798 	struct super_block *sb = dquot->dq_sb;
6799 
6800 	if (ext4_is_quota_journalled(sb)) {
6801 		dquot_mark_dquot_dirty(dquot);
6802 		return ext4_write_dquot(dquot);
6803 	} else {
6804 		return dquot_mark_dquot_dirty(dquot);
6805 	}
6806 }
6807 
6808 static int ext4_write_info(struct super_block *sb, int type)
6809 {
6810 	int ret, err;
6811 	handle_t *handle;
6812 
6813 	/* Data block + inode block */
6814 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6815 	if (IS_ERR(handle))
6816 		return PTR_ERR(handle);
6817 	ret = dquot_commit_info(sb, type);
6818 	err = ext4_journal_stop(handle);
6819 	if (!ret)
6820 		ret = err;
6821 	return ret;
6822 }
6823 
6824 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6825 {
6826 	struct ext4_inode_info *ei = EXT4_I(inode);
6827 
6828 	/* The first argument of lockdep_set_subclass has to be
6829 	 * *exactly* the same as the argument to init_rwsem() --- in
6830 	 * this case, in init_once() --- or lockdep gets unhappy
6831 	 * because the name of the lock is set using the
6832 	 * stringification of the argument to init_rwsem().
6833 	 */
6834 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6835 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6836 }
6837 
6838 /*
6839  * Standard function to be called on quota_on
6840  */
6841 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6842 			 const struct path *path)
6843 {
6844 	int err;
6845 
6846 	if (!test_opt(sb, QUOTA))
6847 		return -EINVAL;
6848 
6849 	/* Quotafile not on the same filesystem? */
6850 	if (path->dentry->d_sb != sb)
6851 		return -EXDEV;
6852 
6853 	/* Quota already enabled for this file? */
6854 	if (IS_NOQUOTA(d_inode(path->dentry)))
6855 		return -EBUSY;
6856 
6857 	/* Journaling quota? */
6858 	if (EXT4_SB(sb)->s_qf_names[type]) {
6859 		/* Quotafile not in fs root? */
6860 		if (path->dentry->d_parent != sb->s_root)
6861 			ext4_msg(sb, KERN_WARNING,
6862 				"Quota file not on filesystem root. "
6863 				"Journaled quota will not work");
6864 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6865 	} else {
6866 		/*
6867 		 * Clear the flag just in case mount options changed since
6868 		 * last time.
6869 		 */
6870 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6871 	}
6872 
6873 	/*
6874 	 * When we journal data on quota file, we have to flush journal to see
6875 	 * all updates to the file when we bypass pagecache...
6876 	 */
6877 	if (EXT4_SB(sb)->s_journal &&
6878 	    ext4_should_journal_data(d_inode(path->dentry))) {
6879 		/*
6880 		 * We don't need to lock updates but journal_flush() could
6881 		 * otherwise be livelocked...
6882 		 */
6883 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6884 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6885 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6886 		if (err)
6887 			return err;
6888 	}
6889 
6890 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6891 	err = dquot_quota_on(sb, type, format_id, path);
6892 	if (!err) {
6893 		struct inode *inode = d_inode(path->dentry);
6894 		handle_t *handle;
6895 
6896 		/*
6897 		 * Set inode flags to prevent userspace from messing with quota
6898 		 * files. If this fails, we return success anyway since quotas
6899 		 * are already enabled and this is not a hard failure.
6900 		 */
6901 		inode_lock(inode);
6902 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6903 		if (IS_ERR(handle))
6904 			goto unlock_inode;
6905 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6906 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6907 				S_NOATIME | S_IMMUTABLE);
6908 		err = ext4_mark_inode_dirty(handle, inode);
6909 		ext4_journal_stop(handle);
6910 	unlock_inode:
6911 		inode_unlock(inode);
6912 		if (err)
6913 			dquot_quota_off(sb, type);
6914 	}
6915 	if (err)
6916 		lockdep_set_quota_inode(path->dentry->d_inode,
6917 					     I_DATA_SEM_NORMAL);
6918 	return err;
6919 }
6920 
6921 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
6922 {
6923 	switch (type) {
6924 	case USRQUOTA:
6925 		return qf_inum == EXT4_USR_QUOTA_INO;
6926 	case GRPQUOTA:
6927 		return qf_inum == EXT4_GRP_QUOTA_INO;
6928 	case PRJQUOTA:
6929 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
6930 	default:
6931 		BUG();
6932 	}
6933 }
6934 
6935 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6936 			     unsigned int flags)
6937 {
6938 	int err;
6939 	struct inode *qf_inode;
6940 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6941 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6942 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6943 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6944 	};
6945 
6946 	BUG_ON(!ext4_has_feature_quota(sb));
6947 
6948 	if (!qf_inums[type])
6949 		return -EPERM;
6950 
6951 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
6952 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
6953 				qf_inums[type], type);
6954 		return -EUCLEAN;
6955 	}
6956 
6957 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6958 	if (IS_ERR(qf_inode)) {
6959 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
6960 				qf_inums[type], type);
6961 		return PTR_ERR(qf_inode);
6962 	}
6963 
6964 	/* Don't account quota for quota files to avoid recursion */
6965 	qf_inode->i_flags |= S_NOQUOTA;
6966 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6967 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6968 	if (err)
6969 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6970 	iput(qf_inode);
6971 
6972 	return err;
6973 }
6974 
6975 /* Enable usage tracking for all quota types. */
6976 int ext4_enable_quotas(struct super_block *sb)
6977 {
6978 	int type, err = 0;
6979 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6980 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6981 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6982 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6983 	};
6984 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6985 		test_opt(sb, USRQUOTA),
6986 		test_opt(sb, GRPQUOTA),
6987 		test_opt(sb, PRJQUOTA),
6988 	};
6989 
6990 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6991 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6992 		if (qf_inums[type]) {
6993 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6994 				DQUOT_USAGE_ENABLED |
6995 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6996 			if (err) {
6997 				ext4_warning(sb,
6998 					"Failed to enable quota tracking "
6999 					"(type=%d, err=%d, ino=%lu). "
7000 					"Please run e2fsck to fix.", type,
7001 					err, qf_inums[type]);
7002 				for (type--; type >= 0; type--) {
7003 					struct inode *inode;
7004 
7005 					inode = sb_dqopt(sb)->files[type];
7006 					if (inode)
7007 						inode = igrab(inode);
7008 					dquot_quota_off(sb, type);
7009 					if (inode) {
7010 						lockdep_set_quota_inode(inode,
7011 							I_DATA_SEM_NORMAL);
7012 						iput(inode);
7013 					}
7014 				}
7015 
7016 				return err;
7017 			}
7018 		}
7019 	}
7020 	return 0;
7021 }
7022 
7023 static int ext4_quota_off(struct super_block *sb, int type)
7024 {
7025 	struct inode *inode = sb_dqopt(sb)->files[type];
7026 	handle_t *handle;
7027 	int err;
7028 
7029 	/* Force all delayed allocation blocks to be allocated.
7030 	 * Caller already holds s_umount sem */
7031 	if (test_opt(sb, DELALLOC))
7032 		sync_filesystem(sb);
7033 
7034 	if (!inode || !igrab(inode))
7035 		goto out;
7036 
7037 	err = dquot_quota_off(sb, type);
7038 	if (err || ext4_has_feature_quota(sb))
7039 		goto out_put;
7040 
7041 	inode_lock(inode);
7042 	/*
7043 	 * Update modification times of quota files when userspace can
7044 	 * start looking at them. If we fail, we return success anyway since
7045 	 * this is not a hard failure and quotas are already disabled.
7046 	 */
7047 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7048 	if (IS_ERR(handle)) {
7049 		err = PTR_ERR(handle);
7050 		goto out_unlock;
7051 	}
7052 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7053 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7054 	inode->i_mtime = inode->i_ctime = current_time(inode);
7055 	err = ext4_mark_inode_dirty(handle, inode);
7056 	ext4_journal_stop(handle);
7057 out_unlock:
7058 	inode_unlock(inode);
7059 out_put:
7060 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7061 	iput(inode);
7062 	return err;
7063 out:
7064 	return dquot_quota_off(sb, type);
7065 }
7066 
7067 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7068  * acquiring the locks... As quota files are never truncated and quota code
7069  * itself serializes the operations (and no one else should touch the files)
7070  * we don't have to be afraid of races */
7071 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7072 			       size_t len, loff_t off)
7073 {
7074 	struct inode *inode = sb_dqopt(sb)->files[type];
7075 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7076 	int offset = off & (sb->s_blocksize - 1);
7077 	int tocopy;
7078 	size_t toread;
7079 	struct buffer_head *bh;
7080 	loff_t i_size = i_size_read(inode);
7081 
7082 	if (off > i_size)
7083 		return 0;
7084 	if (off+len > i_size)
7085 		len = i_size-off;
7086 	toread = len;
7087 	while (toread > 0) {
7088 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7089 		bh = ext4_bread(NULL, inode, blk, 0);
7090 		if (IS_ERR(bh))
7091 			return PTR_ERR(bh);
7092 		if (!bh)	/* A hole? */
7093 			memset(data, 0, tocopy);
7094 		else
7095 			memcpy(data, bh->b_data+offset, tocopy);
7096 		brelse(bh);
7097 		offset = 0;
7098 		toread -= tocopy;
7099 		data += tocopy;
7100 		blk++;
7101 	}
7102 	return len;
7103 }
7104 
7105 /* Write to quotafile (we know the transaction is already started and has
7106  * enough credits) */
7107 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7108 				const char *data, size_t len, loff_t off)
7109 {
7110 	struct inode *inode = sb_dqopt(sb)->files[type];
7111 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7112 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7113 	int retries = 0;
7114 	struct buffer_head *bh;
7115 	handle_t *handle = journal_current_handle();
7116 
7117 	if (!handle) {
7118 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7119 			" cancelled because transaction is not started",
7120 			(unsigned long long)off, (unsigned long long)len);
7121 		return -EIO;
7122 	}
7123 	/*
7124 	 * Since we account only one data block in transaction credits,
7125 	 * then it is impossible to cross a block boundary.
7126 	 */
7127 	if (sb->s_blocksize - offset < len) {
7128 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7129 			" cancelled because not block aligned",
7130 			(unsigned long long)off, (unsigned long long)len);
7131 		return -EIO;
7132 	}
7133 
7134 	do {
7135 		bh = ext4_bread(handle, inode, blk,
7136 				EXT4_GET_BLOCKS_CREATE |
7137 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7138 	} while (PTR_ERR(bh) == -ENOSPC &&
7139 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7140 	if (IS_ERR(bh))
7141 		return PTR_ERR(bh);
7142 	if (!bh)
7143 		goto out;
7144 	BUFFER_TRACE(bh, "get write access");
7145 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7146 	if (err) {
7147 		brelse(bh);
7148 		return err;
7149 	}
7150 	lock_buffer(bh);
7151 	memcpy(bh->b_data+offset, data, len);
7152 	flush_dcache_page(bh->b_page);
7153 	unlock_buffer(bh);
7154 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7155 	brelse(bh);
7156 out:
7157 	if (inode->i_size < off + len) {
7158 		i_size_write(inode, off + len);
7159 		EXT4_I(inode)->i_disksize = inode->i_size;
7160 		err2 = ext4_mark_inode_dirty(handle, inode);
7161 		if (unlikely(err2 && !err))
7162 			err = err2;
7163 	}
7164 	return err ? err : len;
7165 }
7166 #endif
7167 
7168 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7169 static inline void register_as_ext2(void)
7170 {
7171 	int err = register_filesystem(&ext2_fs_type);
7172 	if (err)
7173 		printk(KERN_WARNING
7174 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7175 }
7176 
7177 static inline void unregister_as_ext2(void)
7178 {
7179 	unregister_filesystem(&ext2_fs_type);
7180 }
7181 
7182 static inline int ext2_feature_set_ok(struct super_block *sb)
7183 {
7184 	if (ext4_has_unknown_ext2_incompat_features(sb))
7185 		return 0;
7186 	if (sb_rdonly(sb))
7187 		return 1;
7188 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7189 		return 0;
7190 	return 1;
7191 }
7192 #else
7193 static inline void register_as_ext2(void) { }
7194 static inline void unregister_as_ext2(void) { }
7195 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7196 #endif
7197 
7198 static inline void register_as_ext3(void)
7199 {
7200 	int err = register_filesystem(&ext3_fs_type);
7201 	if (err)
7202 		printk(KERN_WARNING
7203 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7204 }
7205 
7206 static inline void unregister_as_ext3(void)
7207 {
7208 	unregister_filesystem(&ext3_fs_type);
7209 }
7210 
7211 static inline int ext3_feature_set_ok(struct super_block *sb)
7212 {
7213 	if (ext4_has_unknown_ext3_incompat_features(sb))
7214 		return 0;
7215 	if (!ext4_has_feature_journal(sb))
7216 		return 0;
7217 	if (sb_rdonly(sb))
7218 		return 1;
7219 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7220 		return 0;
7221 	return 1;
7222 }
7223 
7224 static struct file_system_type ext4_fs_type = {
7225 	.owner			= THIS_MODULE,
7226 	.name			= "ext4",
7227 	.init_fs_context	= ext4_init_fs_context,
7228 	.parameters		= ext4_param_specs,
7229 	.kill_sb		= kill_block_super,
7230 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7231 };
7232 MODULE_ALIAS_FS("ext4");
7233 
7234 /* Shared across all ext4 file systems */
7235 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7236 
7237 static int __init ext4_init_fs(void)
7238 {
7239 	int i, err;
7240 
7241 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7242 	ext4_li_info = NULL;
7243 
7244 	/* Build-time check for flags consistency */
7245 	ext4_check_flag_values();
7246 
7247 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7248 		init_waitqueue_head(&ext4__ioend_wq[i]);
7249 
7250 	err = ext4_init_es();
7251 	if (err)
7252 		return err;
7253 
7254 	err = ext4_init_pending();
7255 	if (err)
7256 		goto out7;
7257 
7258 	err = ext4_init_post_read_processing();
7259 	if (err)
7260 		goto out6;
7261 
7262 	err = ext4_init_pageio();
7263 	if (err)
7264 		goto out5;
7265 
7266 	err = ext4_init_system_zone();
7267 	if (err)
7268 		goto out4;
7269 
7270 	err = ext4_init_sysfs();
7271 	if (err)
7272 		goto out3;
7273 
7274 	err = ext4_init_mballoc();
7275 	if (err)
7276 		goto out2;
7277 	err = init_inodecache();
7278 	if (err)
7279 		goto out1;
7280 
7281 	err = ext4_fc_init_dentry_cache();
7282 	if (err)
7283 		goto out05;
7284 
7285 	register_as_ext3();
7286 	register_as_ext2();
7287 	err = register_filesystem(&ext4_fs_type);
7288 	if (err)
7289 		goto out;
7290 
7291 	return 0;
7292 out:
7293 	unregister_as_ext2();
7294 	unregister_as_ext3();
7295 	ext4_fc_destroy_dentry_cache();
7296 out05:
7297 	destroy_inodecache();
7298 out1:
7299 	ext4_exit_mballoc();
7300 out2:
7301 	ext4_exit_sysfs();
7302 out3:
7303 	ext4_exit_system_zone();
7304 out4:
7305 	ext4_exit_pageio();
7306 out5:
7307 	ext4_exit_post_read_processing();
7308 out6:
7309 	ext4_exit_pending();
7310 out7:
7311 	ext4_exit_es();
7312 
7313 	return err;
7314 }
7315 
7316 static void __exit ext4_exit_fs(void)
7317 {
7318 	ext4_destroy_lazyinit_thread();
7319 	unregister_as_ext2();
7320 	unregister_as_ext3();
7321 	unregister_filesystem(&ext4_fs_type);
7322 	ext4_fc_destroy_dentry_cache();
7323 	destroy_inodecache();
7324 	ext4_exit_mballoc();
7325 	ext4_exit_sysfs();
7326 	ext4_exit_system_zone();
7327 	ext4_exit_pageio();
7328 	ext4_exit_post_read_processing();
7329 	ext4_exit_es();
7330 	ext4_exit_pending();
7331 }
7332 
7333 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7334 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7335 MODULE_LICENSE("GPL");
7336 MODULE_SOFTDEP("pre: crc32c");
7337 module_init(ext4_init_fs)
7338 module_exit(ext4_exit_fs)
7339