xref: /openbmc/linux/fs/ext4/super.c (revision ac73d4bf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= kill_block_super,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= kill_block_super,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ | op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
207 {
208 	lock_buffer(bh);
209 	if (!wait) {
210 		ext4_read_bh_nowait(bh, op_flags, NULL);
211 		return 0;
212 	}
213 	return ext4_read_bh(bh, op_flags, NULL);
214 }
215 
216 /*
217  * This works like __bread_gfp() except it uses ERR_PTR for error
218  * returns.  Currently with sb_bread it's impossible to distinguish
219  * between ENOMEM and EIO situations (since both result in a NULL
220  * return.
221  */
222 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
223 					       sector_t block,
224 					       blk_opf_t op_flags, gfp_t gfp)
225 {
226 	struct buffer_head *bh;
227 	int ret;
228 
229 	bh = sb_getblk_gfp(sb, block, gfp);
230 	if (bh == NULL)
231 		return ERR_PTR(-ENOMEM);
232 	if (ext4_buffer_uptodate(bh))
233 		return bh;
234 
235 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
236 	if (ret) {
237 		put_bh(bh);
238 		return ERR_PTR(ret);
239 	}
240 	return bh;
241 }
242 
243 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
244 				   blk_opf_t op_flags)
245 {
246 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
247 }
248 
249 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
250 					    sector_t block)
251 {
252 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
253 }
254 
255 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
256 {
257 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
258 
259 	if (likely(bh)) {
260 		if (trylock_buffer(bh))
261 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
262 		brelse(bh);
263 	}
264 }
265 
266 static int ext4_verify_csum_type(struct super_block *sb,
267 				 struct ext4_super_block *es)
268 {
269 	if (!ext4_has_feature_metadata_csum(sb))
270 		return 1;
271 
272 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
273 }
274 
275 __le32 ext4_superblock_csum(struct super_block *sb,
276 			    struct ext4_super_block *es)
277 {
278 	struct ext4_sb_info *sbi = EXT4_SB(sb);
279 	int offset = offsetof(struct ext4_super_block, s_checksum);
280 	__u32 csum;
281 
282 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
283 
284 	return cpu_to_le32(csum);
285 }
286 
287 static int ext4_superblock_csum_verify(struct super_block *sb,
288 				       struct ext4_super_block *es)
289 {
290 	if (!ext4_has_metadata_csum(sb))
291 		return 1;
292 
293 	return es->s_checksum == ext4_superblock_csum(sb, es);
294 }
295 
296 void ext4_superblock_csum_set(struct super_block *sb)
297 {
298 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
299 
300 	if (!ext4_has_metadata_csum(sb))
301 		return;
302 
303 	es->s_checksum = ext4_superblock_csum(sb, es);
304 }
305 
306 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
307 			       struct ext4_group_desc *bg)
308 {
309 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
310 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
311 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
312 }
313 
314 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
323 			      struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_table_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
328 }
329 
330 __u32 ext4_free_group_clusters(struct super_block *sb,
331 			       struct ext4_group_desc *bg)
332 {
333 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
336 }
337 
338 __u32 ext4_free_inodes_count(struct super_block *sb,
339 			      struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_used_dirs_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
352 }
353 
354 __u32 ext4_itable_unused_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_itable_unused_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
360 }
361 
362 void ext4_block_bitmap_set(struct super_block *sb,
363 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
364 {
365 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
366 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
367 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
368 }
369 
370 void ext4_inode_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_table_set(struct super_block *sb,
379 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_free_group_clusters_set(struct super_block *sb,
387 				  struct ext4_group_desc *bg, __u32 count)
388 {
389 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
392 }
393 
394 void ext4_free_inodes_set(struct super_block *sb,
395 			  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_used_dirs_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
408 }
409 
410 void ext4_itable_unused_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
416 }
417 
418 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
419 {
420 	now = clamp_val(now, 0, (1ull << 40) - 1);
421 
422 	*lo = cpu_to_le32(lower_32_bits(now));
423 	*hi = upper_32_bits(now);
424 }
425 
426 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
427 {
428 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
429 }
430 #define ext4_update_tstamp(es, tstamp) \
431 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
432 			     ktime_get_real_seconds())
433 #define ext4_get_tstamp(es, tstamp) \
434 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
435 
436 /*
437  * The del_gendisk() function uninitializes the disk-specific data
438  * structures, including the bdi structure, without telling anyone
439  * else.  Once this happens, any attempt to call mark_buffer_dirty()
440  * (for example, by ext4_commit_super), will cause a kernel OOPS.
441  * This is a kludge to prevent these oops until we can put in a proper
442  * hook in del_gendisk() to inform the VFS and file system layers.
443  */
444 static int block_device_ejected(struct super_block *sb)
445 {
446 	struct inode *bd_inode = sb->s_bdev->bd_inode;
447 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
448 
449 	return bdi->dev == NULL;
450 }
451 
452 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
453 {
454 	struct super_block		*sb = journal->j_private;
455 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
456 	int				error = is_journal_aborted(journal);
457 	struct ext4_journal_cb_entry	*jce;
458 
459 	BUG_ON(txn->t_state == T_FINISHED);
460 
461 	ext4_process_freed_data(sb, txn->t_tid);
462 
463 	spin_lock(&sbi->s_md_lock);
464 	while (!list_empty(&txn->t_private_list)) {
465 		jce = list_entry(txn->t_private_list.next,
466 				 struct ext4_journal_cb_entry, jce_list);
467 		list_del_init(&jce->jce_list);
468 		spin_unlock(&sbi->s_md_lock);
469 		jce->jce_func(sb, jce, error);
470 		spin_lock(&sbi->s_md_lock);
471 	}
472 	spin_unlock(&sbi->s_md_lock);
473 }
474 
475 /*
476  * This writepage callback for write_cache_pages()
477  * takes care of a few cases after page cleaning.
478  *
479  * write_cache_pages() already checks for dirty pages
480  * and calls clear_page_dirty_for_io(), which we want,
481  * to write protect the pages.
482  *
483  * However, we may have to redirty a page (see below.)
484  */
485 static int ext4_journalled_writepage_callback(struct page *page,
486 					      struct writeback_control *wbc,
487 					      void *data)
488 {
489 	transaction_t *transaction = (transaction_t *) data;
490 	struct buffer_head *bh, *head;
491 	struct journal_head *jh;
492 
493 	bh = head = page_buffers(page);
494 	do {
495 		/*
496 		 * We have to redirty a page in these cases:
497 		 * 1) If buffer is dirty, it means the page was dirty because it
498 		 * contains a buffer that needs checkpointing. So the dirty bit
499 		 * needs to be preserved so that checkpointing writes the buffer
500 		 * properly.
501 		 * 2) If buffer is not part of the committing transaction
502 		 * (we may have just accidentally come across this buffer because
503 		 * inode range tracking is not exact) or if the currently running
504 		 * transaction already contains this buffer as well, dirty bit
505 		 * needs to be preserved so that the buffer gets writeprotected
506 		 * properly on running transaction's commit.
507 		 */
508 		jh = bh2jh(bh);
509 		if (buffer_dirty(bh) ||
510 		    (jh && (jh->b_transaction != transaction ||
511 			    jh->b_next_transaction))) {
512 			redirty_page_for_writepage(wbc, page);
513 			goto out;
514 		}
515 	} while ((bh = bh->b_this_page) != head);
516 
517 out:
518 	return AOP_WRITEPAGE_ACTIVATE;
519 }
520 
521 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
522 {
523 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
524 	struct writeback_control wbc = {
525 		.sync_mode =  WB_SYNC_ALL,
526 		.nr_to_write = LONG_MAX,
527 		.range_start = jinode->i_dirty_start,
528 		.range_end = jinode->i_dirty_end,
529         };
530 
531 	return write_cache_pages(mapping, &wbc,
532 				 ext4_journalled_writepage_callback,
533 				 jinode->i_transaction);
534 }
535 
536 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
537 {
538 	int ret;
539 
540 	if (ext4_should_journal_data(jinode->i_vfs_inode))
541 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
542 	else
543 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
544 
545 	return ret;
546 }
547 
548 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
549 {
550 	int ret = 0;
551 
552 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
553 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
554 
555 	return ret;
556 }
557 
558 static bool system_going_down(void)
559 {
560 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
561 		|| system_state == SYSTEM_RESTART;
562 }
563 
564 struct ext4_err_translation {
565 	int code;
566 	int errno;
567 };
568 
569 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
570 
571 static struct ext4_err_translation err_translation[] = {
572 	EXT4_ERR_TRANSLATE(EIO),
573 	EXT4_ERR_TRANSLATE(ENOMEM),
574 	EXT4_ERR_TRANSLATE(EFSBADCRC),
575 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
576 	EXT4_ERR_TRANSLATE(ENOSPC),
577 	EXT4_ERR_TRANSLATE(ENOKEY),
578 	EXT4_ERR_TRANSLATE(EROFS),
579 	EXT4_ERR_TRANSLATE(EFBIG),
580 	EXT4_ERR_TRANSLATE(EEXIST),
581 	EXT4_ERR_TRANSLATE(ERANGE),
582 	EXT4_ERR_TRANSLATE(EOVERFLOW),
583 	EXT4_ERR_TRANSLATE(EBUSY),
584 	EXT4_ERR_TRANSLATE(ENOTDIR),
585 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
586 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
587 	EXT4_ERR_TRANSLATE(EFAULT),
588 };
589 
590 static int ext4_errno_to_code(int errno)
591 {
592 	int i;
593 
594 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
595 		if (err_translation[i].errno == errno)
596 			return err_translation[i].code;
597 	return EXT4_ERR_UNKNOWN;
598 }
599 
600 static void save_error_info(struct super_block *sb, int error,
601 			    __u32 ino, __u64 block,
602 			    const char *func, unsigned int line)
603 {
604 	struct ext4_sb_info *sbi = EXT4_SB(sb);
605 
606 	/* We default to EFSCORRUPTED error... */
607 	if (error == 0)
608 		error = EFSCORRUPTED;
609 
610 	spin_lock(&sbi->s_error_lock);
611 	sbi->s_add_error_count++;
612 	sbi->s_last_error_code = error;
613 	sbi->s_last_error_line = line;
614 	sbi->s_last_error_ino = ino;
615 	sbi->s_last_error_block = block;
616 	sbi->s_last_error_func = func;
617 	sbi->s_last_error_time = ktime_get_real_seconds();
618 	if (!sbi->s_first_error_time) {
619 		sbi->s_first_error_code = error;
620 		sbi->s_first_error_line = line;
621 		sbi->s_first_error_ino = ino;
622 		sbi->s_first_error_block = block;
623 		sbi->s_first_error_func = func;
624 		sbi->s_first_error_time = sbi->s_last_error_time;
625 	}
626 	spin_unlock(&sbi->s_error_lock);
627 }
628 
629 /* Deal with the reporting of failure conditions on a filesystem such as
630  * inconsistencies detected or read IO failures.
631  *
632  * On ext2, we can store the error state of the filesystem in the
633  * superblock.  That is not possible on ext4, because we may have other
634  * write ordering constraints on the superblock which prevent us from
635  * writing it out straight away; and given that the journal is about to
636  * be aborted, we can't rely on the current, or future, transactions to
637  * write out the superblock safely.
638  *
639  * We'll just use the jbd2_journal_abort() error code to record an error in
640  * the journal instead.  On recovery, the journal will complain about
641  * that error until we've noted it down and cleared it.
642  *
643  * If force_ro is set, we unconditionally force the filesystem into an
644  * ABORT|READONLY state, unless the error response on the fs has been set to
645  * panic in which case we take the easy way out and panic immediately. This is
646  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
647  * at a critical moment in log management.
648  */
649 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
650 			      __u32 ino, __u64 block,
651 			      const char *func, unsigned int line)
652 {
653 	journal_t *journal = EXT4_SB(sb)->s_journal;
654 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
655 
656 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
657 	if (test_opt(sb, WARN_ON_ERROR))
658 		WARN_ON_ONCE(1);
659 
660 	if (!continue_fs && !sb_rdonly(sb)) {
661 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
662 		if (journal)
663 			jbd2_journal_abort(journal, -EIO);
664 	}
665 
666 	if (!bdev_read_only(sb->s_bdev)) {
667 		save_error_info(sb, error, ino, block, func, line);
668 		/*
669 		 * In case the fs should keep running, we need to writeout
670 		 * superblock through the journal. Due to lock ordering
671 		 * constraints, it may not be safe to do it right here so we
672 		 * defer superblock flushing to a workqueue.
673 		 */
674 		if (continue_fs && journal)
675 			schedule_work(&EXT4_SB(sb)->s_error_work);
676 		else
677 			ext4_commit_super(sb);
678 	}
679 
680 	/*
681 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
682 	 * could panic during 'reboot -f' as the underlying device got already
683 	 * disabled.
684 	 */
685 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
686 		panic("EXT4-fs (device %s): panic forced after error\n",
687 			sb->s_id);
688 	}
689 
690 	if (sb_rdonly(sb) || continue_fs)
691 		return;
692 
693 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
694 	/*
695 	 * Make sure updated value of ->s_mount_flags will be visible before
696 	 * ->s_flags update
697 	 */
698 	smp_wmb();
699 	sb->s_flags |= SB_RDONLY;
700 }
701 
702 static void flush_stashed_error_work(struct work_struct *work)
703 {
704 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
705 						s_error_work);
706 	journal_t *journal = sbi->s_journal;
707 	handle_t *handle;
708 
709 	/*
710 	 * If the journal is still running, we have to write out superblock
711 	 * through the journal to avoid collisions of other journalled sb
712 	 * updates.
713 	 *
714 	 * We use directly jbd2 functions here to avoid recursing back into
715 	 * ext4 error handling code during handling of previous errors.
716 	 */
717 	if (!sb_rdonly(sbi->s_sb) && journal) {
718 		struct buffer_head *sbh = sbi->s_sbh;
719 		handle = jbd2_journal_start(journal, 1);
720 		if (IS_ERR(handle))
721 			goto write_directly;
722 		if (jbd2_journal_get_write_access(handle, sbh)) {
723 			jbd2_journal_stop(handle);
724 			goto write_directly;
725 		}
726 		ext4_update_super(sbi->s_sb);
727 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
728 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
729 				 "superblock detected");
730 			clear_buffer_write_io_error(sbh);
731 			set_buffer_uptodate(sbh);
732 		}
733 
734 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
735 			jbd2_journal_stop(handle);
736 			goto write_directly;
737 		}
738 		jbd2_journal_stop(handle);
739 		ext4_notify_error_sysfs(sbi);
740 		return;
741 	}
742 write_directly:
743 	/*
744 	 * Write through journal failed. Write sb directly to get error info
745 	 * out and hope for the best.
746 	 */
747 	ext4_commit_super(sbi->s_sb);
748 	ext4_notify_error_sysfs(sbi);
749 }
750 
751 #define ext4_error_ratelimit(sb)					\
752 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
753 			     "EXT4-fs error")
754 
755 void __ext4_error(struct super_block *sb, const char *function,
756 		  unsigned int line, bool force_ro, int error, __u64 block,
757 		  const char *fmt, ...)
758 {
759 	struct va_format vaf;
760 	va_list args;
761 
762 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
763 		return;
764 
765 	trace_ext4_error(sb, function, line);
766 	if (ext4_error_ratelimit(sb)) {
767 		va_start(args, fmt);
768 		vaf.fmt = fmt;
769 		vaf.va = &args;
770 		printk(KERN_CRIT
771 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
772 		       sb->s_id, function, line, current->comm, &vaf);
773 		va_end(args);
774 	}
775 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
776 
777 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
778 }
779 
780 void __ext4_error_inode(struct inode *inode, const char *function,
781 			unsigned int line, ext4_fsblk_t block, int error,
782 			const char *fmt, ...)
783 {
784 	va_list args;
785 	struct va_format vaf;
786 
787 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
788 		return;
789 
790 	trace_ext4_error(inode->i_sb, function, line);
791 	if (ext4_error_ratelimit(inode->i_sb)) {
792 		va_start(args, fmt);
793 		vaf.fmt = fmt;
794 		vaf.va = &args;
795 		if (block)
796 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
797 			       "inode #%lu: block %llu: comm %s: %pV\n",
798 			       inode->i_sb->s_id, function, line, inode->i_ino,
799 			       block, current->comm, &vaf);
800 		else
801 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
802 			       "inode #%lu: comm %s: %pV\n",
803 			       inode->i_sb->s_id, function, line, inode->i_ino,
804 			       current->comm, &vaf);
805 		va_end(args);
806 	}
807 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
808 
809 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
810 			  function, line);
811 }
812 
813 void __ext4_error_file(struct file *file, const char *function,
814 		       unsigned int line, ext4_fsblk_t block,
815 		       const char *fmt, ...)
816 {
817 	va_list args;
818 	struct va_format vaf;
819 	struct inode *inode = file_inode(file);
820 	char pathname[80], *path;
821 
822 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
823 		return;
824 
825 	trace_ext4_error(inode->i_sb, function, line);
826 	if (ext4_error_ratelimit(inode->i_sb)) {
827 		path = file_path(file, pathname, sizeof(pathname));
828 		if (IS_ERR(path))
829 			path = "(unknown)";
830 		va_start(args, fmt);
831 		vaf.fmt = fmt;
832 		vaf.va = &args;
833 		if (block)
834 			printk(KERN_CRIT
835 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
836 			       "block %llu: comm %s: path %s: %pV\n",
837 			       inode->i_sb->s_id, function, line, inode->i_ino,
838 			       block, current->comm, path, &vaf);
839 		else
840 			printk(KERN_CRIT
841 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
842 			       "comm %s: path %s: %pV\n",
843 			       inode->i_sb->s_id, function, line, inode->i_ino,
844 			       current->comm, path, &vaf);
845 		va_end(args);
846 	}
847 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
848 
849 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
850 			  function, line);
851 }
852 
853 const char *ext4_decode_error(struct super_block *sb, int errno,
854 			      char nbuf[16])
855 {
856 	char *errstr = NULL;
857 
858 	switch (errno) {
859 	case -EFSCORRUPTED:
860 		errstr = "Corrupt filesystem";
861 		break;
862 	case -EFSBADCRC:
863 		errstr = "Filesystem failed CRC";
864 		break;
865 	case -EIO:
866 		errstr = "IO failure";
867 		break;
868 	case -ENOMEM:
869 		errstr = "Out of memory";
870 		break;
871 	case -EROFS:
872 		if (!sb || (EXT4_SB(sb)->s_journal &&
873 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
874 			errstr = "Journal has aborted";
875 		else
876 			errstr = "Readonly filesystem";
877 		break;
878 	default:
879 		/* If the caller passed in an extra buffer for unknown
880 		 * errors, textualise them now.  Else we just return
881 		 * NULL. */
882 		if (nbuf) {
883 			/* Check for truncated error codes... */
884 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
885 				errstr = nbuf;
886 		}
887 		break;
888 	}
889 
890 	return errstr;
891 }
892 
893 /* __ext4_std_error decodes expected errors from journaling functions
894  * automatically and invokes the appropriate error response.  */
895 
896 void __ext4_std_error(struct super_block *sb, const char *function,
897 		      unsigned int line, int errno)
898 {
899 	char nbuf[16];
900 	const char *errstr;
901 
902 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
903 		return;
904 
905 	/* Special case: if the error is EROFS, and we're not already
906 	 * inside a transaction, then there's really no point in logging
907 	 * an error. */
908 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
909 		return;
910 
911 	if (ext4_error_ratelimit(sb)) {
912 		errstr = ext4_decode_error(sb, errno, nbuf);
913 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
914 		       sb->s_id, function, line, errstr);
915 	}
916 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
917 
918 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
919 }
920 
921 void __ext4_msg(struct super_block *sb,
922 		const char *prefix, const char *fmt, ...)
923 {
924 	struct va_format vaf;
925 	va_list args;
926 
927 	if (sb) {
928 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
929 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
930 				  "EXT4-fs"))
931 			return;
932 	}
933 
934 	va_start(args, fmt);
935 	vaf.fmt = fmt;
936 	vaf.va = &args;
937 	if (sb)
938 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
939 	else
940 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
941 	va_end(args);
942 }
943 
944 static int ext4_warning_ratelimit(struct super_block *sb)
945 {
946 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
947 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
948 			    "EXT4-fs warning");
949 }
950 
951 void __ext4_warning(struct super_block *sb, const char *function,
952 		    unsigned int line, const char *fmt, ...)
953 {
954 	struct va_format vaf;
955 	va_list args;
956 
957 	if (!ext4_warning_ratelimit(sb))
958 		return;
959 
960 	va_start(args, fmt);
961 	vaf.fmt = fmt;
962 	vaf.va = &args;
963 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
964 	       sb->s_id, function, line, &vaf);
965 	va_end(args);
966 }
967 
968 void __ext4_warning_inode(const struct inode *inode, const char *function,
969 			  unsigned int line, const char *fmt, ...)
970 {
971 	struct va_format vaf;
972 	va_list args;
973 
974 	if (!ext4_warning_ratelimit(inode->i_sb))
975 		return;
976 
977 	va_start(args, fmt);
978 	vaf.fmt = fmt;
979 	vaf.va = &args;
980 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
981 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
982 	       function, line, inode->i_ino, current->comm, &vaf);
983 	va_end(args);
984 }
985 
986 void __ext4_grp_locked_error(const char *function, unsigned int line,
987 			     struct super_block *sb, ext4_group_t grp,
988 			     unsigned long ino, ext4_fsblk_t block,
989 			     const char *fmt, ...)
990 __releases(bitlock)
991 __acquires(bitlock)
992 {
993 	struct va_format vaf;
994 	va_list args;
995 
996 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
997 		return;
998 
999 	trace_ext4_error(sb, function, line);
1000 	if (ext4_error_ratelimit(sb)) {
1001 		va_start(args, fmt);
1002 		vaf.fmt = fmt;
1003 		vaf.va = &args;
1004 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1005 		       sb->s_id, function, line, grp);
1006 		if (ino)
1007 			printk(KERN_CONT "inode %lu: ", ino);
1008 		if (block)
1009 			printk(KERN_CONT "block %llu:",
1010 			       (unsigned long long) block);
1011 		printk(KERN_CONT "%pV\n", &vaf);
1012 		va_end(args);
1013 	}
1014 
1015 	if (test_opt(sb, ERRORS_CONT)) {
1016 		if (test_opt(sb, WARN_ON_ERROR))
1017 			WARN_ON_ONCE(1);
1018 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1019 		if (!bdev_read_only(sb->s_bdev)) {
1020 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1021 					line);
1022 			schedule_work(&EXT4_SB(sb)->s_error_work);
1023 		}
1024 		return;
1025 	}
1026 	ext4_unlock_group(sb, grp);
1027 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1028 	/*
1029 	 * We only get here in the ERRORS_RO case; relocking the group
1030 	 * may be dangerous, but nothing bad will happen since the
1031 	 * filesystem will have already been marked read/only and the
1032 	 * journal has been aborted.  We return 1 as a hint to callers
1033 	 * who might what to use the return value from
1034 	 * ext4_grp_locked_error() to distinguish between the
1035 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1036 	 * aggressively from the ext4 function in question, with a
1037 	 * more appropriate error code.
1038 	 */
1039 	ext4_lock_group(sb, grp);
1040 	return;
1041 }
1042 
1043 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1044 				     ext4_group_t group,
1045 				     unsigned int flags)
1046 {
1047 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1048 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1049 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1050 	int ret;
1051 
1052 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1053 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1054 					    &grp->bb_state);
1055 		if (!ret)
1056 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1057 					   grp->bb_free);
1058 	}
1059 
1060 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1061 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1062 					    &grp->bb_state);
1063 		if (!ret && gdp) {
1064 			int count;
1065 
1066 			count = ext4_free_inodes_count(sb, gdp);
1067 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1068 					   count);
1069 		}
1070 	}
1071 }
1072 
1073 void ext4_update_dynamic_rev(struct super_block *sb)
1074 {
1075 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1076 
1077 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1078 		return;
1079 
1080 	ext4_warning(sb,
1081 		     "updating to rev %d because of new feature flag, "
1082 		     "running e2fsck is recommended",
1083 		     EXT4_DYNAMIC_REV);
1084 
1085 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1086 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1087 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1088 	/* leave es->s_feature_*compat flags alone */
1089 	/* es->s_uuid will be set by e2fsck if empty */
1090 
1091 	/*
1092 	 * The rest of the superblock fields should be zero, and if not it
1093 	 * means they are likely already in use, so leave them alone.  We
1094 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1095 	 */
1096 }
1097 
1098 /*
1099  * Open the external journal device
1100  */
1101 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1102 {
1103 	struct block_device *bdev;
1104 
1105 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1106 	if (IS_ERR(bdev))
1107 		goto fail;
1108 	return bdev;
1109 
1110 fail:
1111 	ext4_msg(sb, KERN_ERR,
1112 		 "failed to open journal device unknown-block(%u,%u) %ld",
1113 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1114 	return NULL;
1115 }
1116 
1117 /*
1118  * Release the journal device
1119  */
1120 static void ext4_blkdev_put(struct block_device *bdev)
1121 {
1122 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1123 }
1124 
1125 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1126 {
1127 	struct block_device *bdev;
1128 	bdev = sbi->s_journal_bdev;
1129 	if (bdev) {
1130 		ext4_blkdev_put(bdev);
1131 		sbi->s_journal_bdev = NULL;
1132 	}
1133 }
1134 
1135 static inline struct inode *orphan_list_entry(struct list_head *l)
1136 {
1137 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1138 }
1139 
1140 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1141 {
1142 	struct list_head *l;
1143 
1144 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1145 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1146 
1147 	printk(KERN_ERR "sb_info orphan list:\n");
1148 	list_for_each(l, &sbi->s_orphan) {
1149 		struct inode *inode = orphan_list_entry(l);
1150 		printk(KERN_ERR "  "
1151 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1152 		       inode->i_sb->s_id, inode->i_ino, inode,
1153 		       inode->i_mode, inode->i_nlink,
1154 		       NEXT_ORPHAN(inode));
1155 	}
1156 }
1157 
1158 #ifdef CONFIG_QUOTA
1159 static int ext4_quota_off(struct super_block *sb, int type);
1160 
1161 static inline void ext4_quota_off_umount(struct super_block *sb)
1162 {
1163 	int type;
1164 
1165 	/* Use our quota_off function to clear inode flags etc. */
1166 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1167 		ext4_quota_off(sb, type);
1168 }
1169 
1170 /*
1171  * This is a helper function which is used in the mount/remount
1172  * codepaths (which holds s_umount) to fetch the quota file name.
1173  */
1174 static inline char *get_qf_name(struct super_block *sb,
1175 				struct ext4_sb_info *sbi,
1176 				int type)
1177 {
1178 	return rcu_dereference_protected(sbi->s_qf_names[type],
1179 					 lockdep_is_held(&sb->s_umount));
1180 }
1181 #else
1182 static inline void ext4_quota_off_umount(struct super_block *sb)
1183 {
1184 }
1185 #endif
1186 
1187 static void ext4_put_super(struct super_block *sb)
1188 {
1189 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1190 	struct ext4_super_block *es = sbi->s_es;
1191 	struct buffer_head **group_desc;
1192 	struct flex_groups **flex_groups;
1193 	int aborted = 0;
1194 	int i, err;
1195 
1196 	/*
1197 	 * Unregister sysfs before destroying jbd2 journal.
1198 	 * Since we could still access attr_journal_task attribute via sysfs
1199 	 * path which could have sbi->s_journal->j_task as NULL
1200 	 * Unregister sysfs before flush sbi->s_error_work.
1201 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1202 	 * read metadata verify failed then will queue error work.
1203 	 * flush_stashed_error_work will call start_this_handle may trigger
1204 	 * BUG_ON.
1205 	 */
1206 	ext4_unregister_sysfs(sb);
1207 
1208 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1209 		ext4_msg(sb, KERN_INFO, "unmounting filesystem.");
1210 
1211 	ext4_unregister_li_request(sb);
1212 	ext4_quota_off_umount(sb);
1213 
1214 	flush_work(&sbi->s_error_work);
1215 	destroy_workqueue(sbi->rsv_conversion_wq);
1216 	ext4_release_orphan_info(sb);
1217 
1218 	if (sbi->s_journal) {
1219 		aborted = is_journal_aborted(sbi->s_journal);
1220 		err = jbd2_journal_destroy(sbi->s_journal);
1221 		sbi->s_journal = NULL;
1222 		if ((err < 0) && !aborted) {
1223 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1224 		}
1225 	}
1226 
1227 	ext4_es_unregister_shrinker(sbi);
1228 	del_timer_sync(&sbi->s_err_report);
1229 	ext4_release_system_zone(sb);
1230 	ext4_mb_release(sb);
1231 	ext4_ext_release(sb);
1232 
1233 	if (!sb_rdonly(sb) && !aborted) {
1234 		ext4_clear_feature_journal_needs_recovery(sb);
1235 		ext4_clear_feature_orphan_present(sb);
1236 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1237 	}
1238 	if (!sb_rdonly(sb))
1239 		ext4_commit_super(sb);
1240 
1241 	rcu_read_lock();
1242 	group_desc = rcu_dereference(sbi->s_group_desc);
1243 	for (i = 0; i < sbi->s_gdb_count; i++)
1244 		brelse(group_desc[i]);
1245 	kvfree(group_desc);
1246 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1247 	if (flex_groups) {
1248 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1249 			kvfree(flex_groups[i]);
1250 		kvfree(flex_groups);
1251 	}
1252 	rcu_read_unlock();
1253 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1254 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1255 	percpu_counter_destroy(&sbi->s_dirs_counter);
1256 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1257 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1258 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1259 #ifdef CONFIG_QUOTA
1260 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1261 		kfree(get_qf_name(sb, sbi, i));
1262 #endif
1263 
1264 	/* Debugging code just in case the in-memory inode orphan list
1265 	 * isn't empty.  The on-disk one can be non-empty if we've
1266 	 * detected an error and taken the fs readonly, but the
1267 	 * in-memory list had better be clean by this point. */
1268 	if (!list_empty(&sbi->s_orphan))
1269 		dump_orphan_list(sb, sbi);
1270 	ASSERT(list_empty(&sbi->s_orphan));
1271 
1272 	sync_blockdev(sb->s_bdev);
1273 	invalidate_bdev(sb->s_bdev);
1274 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1275 		/*
1276 		 * Invalidate the journal device's buffers.  We don't want them
1277 		 * floating about in memory - the physical journal device may
1278 		 * hotswapped, and it breaks the `ro-after' testing code.
1279 		 */
1280 		sync_blockdev(sbi->s_journal_bdev);
1281 		invalidate_bdev(sbi->s_journal_bdev);
1282 		ext4_blkdev_remove(sbi);
1283 	}
1284 
1285 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1286 	sbi->s_ea_inode_cache = NULL;
1287 
1288 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1289 	sbi->s_ea_block_cache = NULL;
1290 
1291 	ext4_stop_mmpd(sbi);
1292 
1293 	brelse(sbi->s_sbh);
1294 	sb->s_fs_info = NULL;
1295 	/*
1296 	 * Now that we are completely done shutting down the
1297 	 * superblock, we need to actually destroy the kobject.
1298 	 */
1299 	kobject_put(&sbi->s_kobj);
1300 	wait_for_completion(&sbi->s_kobj_unregister);
1301 	if (sbi->s_chksum_driver)
1302 		crypto_free_shash(sbi->s_chksum_driver);
1303 	kfree(sbi->s_blockgroup_lock);
1304 	fs_put_dax(sbi->s_daxdev, NULL);
1305 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1306 #if IS_ENABLED(CONFIG_UNICODE)
1307 	utf8_unload(sb->s_encoding);
1308 #endif
1309 	kfree(sbi);
1310 }
1311 
1312 static struct kmem_cache *ext4_inode_cachep;
1313 
1314 /*
1315  * Called inside transaction, so use GFP_NOFS
1316  */
1317 static struct inode *ext4_alloc_inode(struct super_block *sb)
1318 {
1319 	struct ext4_inode_info *ei;
1320 
1321 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1322 	if (!ei)
1323 		return NULL;
1324 
1325 	inode_set_iversion(&ei->vfs_inode, 1);
1326 	spin_lock_init(&ei->i_raw_lock);
1327 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1328 	atomic_set(&ei->i_prealloc_active, 0);
1329 	spin_lock_init(&ei->i_prealloc_lock);
1330 	ext4_es_init_tree(&ei->i_es_tree);
1331 	rwlock_init(&ei->i_es_lock);
1332 	INIT_LIST_HEAD(&ei->i_es_list);
1333 	ei->i_es_all_nr = 0;
1334 	ei->i_es_shk_nr = 0;
1335 	ei->i_es_shrink_lblk = 0;
1336 	ei->i_reserved_data_blocks = 0;
1337 	spin_lock_init(&(ei->i_block_reservation_lock));
1338 	ext4_init_pending_tree(&ei->i_pending_tree);
1339 #ifdef CONFIG_QUOTA
1340 	ei->i_reserved_quota = 0;
1341 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1342 #endif
1343 	ei->jinode = NULL;
1344 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1345 	spin_lock_init(&ei->i_completed_io_lock);
1346 	ei->i_sync_tid = 0;
1347 	ei->i_datasync_tid = 0;
1348 	atomic_set(&ei->i_unwritten, 0);
1349 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1350 	ext4_fc_init_inode(&ei->vfs_inode);
1351 	mutex_init(&ei->i_fc_lock);
1352 	return &ei->vfs_inode;
1353 }
1354 
1355 static int ext4_drop_inode(struct inode *inode)
1356 {
1357 	int drop = generic_drop_inode(inode);
1358 
1359 	if (!drop)
1360 		drop = fscrypt_drop_inode(inode);
1361 
1362 	trace_ext4_drop_inode(inode, drop);
1363 	return drop;
1364 }
1365 
1366 static void ext4_free_in_core_inode(struct inode *inode)
1367 {
1368 	fscrypt_free_inode(inode);
1369 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1370 		pr_warn("%s: inode %ld still in fc list",
1371 			__func__, inode->i_ino);
1372 	}
1373 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1374 }
1375 
1376 static void ext4_destroy_inode(struct inode *inode)
1377 {
1378 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1379 		ext4_msg(inode->i_sb, KERN_ERR,
1380 			 "Inode %lu (%p): orphan list check failed!",
1381 			 inode->i_ino, EXT4_I(inode));
1382 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1383 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1384 				true);
1385 		dump_stack();
1386 	}
1387 
1388 	if (EXT4_I(inode)->i_reserved_data_blocks)
1389 		ext4_msg(inode->i_sb, KERN_ERR,
1390 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1391 			 inode->i_ino, EXT4_I(inode),
1392 			 EXT4_I(inode)->i_reserved_data_blocks);
1393 }
1394 
1395 static void init_once(void *foo)
1396 {
1397 	struct ext4_inode_info *ei = foo;
1398 
1399 	INIT_LIST_HEAD(&ei->i_orphan);
1400 	init_rwsem(&ei->xattr_sem);
1401 	init_rwsem(&ei->i_data_sem);
1402 	inode_init_once(&ei->vfs_inode);
1403 	ext4_fc_init_inode(&ei->vfs_inode);
1404 }
1405 
1406 static int __init init_inodecache(void)
1407 {
1408 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1409 				sizeof(struct ext4_inode_info), 0,
1410 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1411 					SLAB_ACCOUNT),
1412 				offsetof(struct ext4_inode_info, i_data),
1413 				sizeof_field(struct ext4_inode_info, i_data),
1414 				init_once);
1415 	if (ext4_inode_cachep == NULL)
1416 		return -ENOMEM;
1417 	return 0;
1418 }
1419 
1420 static void destroy_inodecache(void)
1421 {
1422 	/*
1423 	 * Make sure all delayed rcu free inodes are flushed before we
1424 	 * destroy cache.
1425 	 */
1426 	rcu_barrier();
1427 	kmem_cache_destroy(ext4_inode_cachep);
1428 }
1429 
1430 void ext4_clear_inode(struct inode *inode)
1431 {
1432 	ext4_fc_del(inode);
1433 	invalidate_inode_buffers(inode);
1434 	clear_inode(inode);
1435 	ext4_discard_preallocations(inode, 0);
1436 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1437 	dquot_drop(inode);
1438 	if (EXT4_I(inode)->jinode) {
1439 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1440 					       EXT4_I(inode)->jinode);
1441 		jbd2_free_inode(EXT4_I(inode)->jinode);
1442 		EXT4_I(inode)->jinode = NULL;
1443 	}
1444 	fscrypt_put_encryption_info(inode);
1445 	fsverity_cleanup_inode(inode);
1446 }
1447 
1448 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1449 					u64 ino, u32 generation)
1450 {
1451 	struct inode *inode;
1452 
1453 	/*
1454 	 * Currently we don't know the generation for parent directory, so
1455 	 * a generation of 0 means "accept any"
1456 	 */
1457 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1458 	if (IS_ERR(inode))
1459 		return ERR_CAST(inode);
1460 	if (generation && inode->i_generation != generation) {
1461 		iput(inode);
1462 		return ERR_PTR(-ESTALE);
1463 	}
1464 
1465 	return inode;
1466 }
1467 
1468 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1469 					int fh_len, int fh_type)
1470 {
1471 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1472 				    ext4_nfs_get_inode);
1473 }
1474 
1475 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1476 					int fh_len, int fh_type)
1477 {
1478 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1479 				    ext4_nfs_get_inode);
1480 }
1481 
1482 static int ext4_nfs_commit_metadata(struct inode *inode)
1483 {
1484 	struct writeback_control wbc = {
1485 		.sync_mode = WB_SYNC_ALL
1486 	};
1487 
1488 	trace_ext4_nfs_commit_metadata(inode);
1489 	return ext4_write_inode(inode, &wbc);
1490 }
1491 
1492 #ifdef CONFIG_QUOTA
1493 static const char * const quotatypes[] = INITQFNAMES;
1494 #define QTYPE2NAME(t) (quotatypes[t])
1495 
1496 static int ext4_write_dquot(struct dquot *dquot);
1497 static int ext4_acquire_dquot(struct dquot *dquot);
1498 static int ext4_release_dquot(struct dquot *dquot);
1499 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1500 static int ext4_write_info(struct super_block *sb, int type);
1501 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1502 			 const struct path *path);
1503 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1504 			       size_t len, loff_t off);
1505 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1506 				const char *data, size_t len, loff_t off);
1507 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1508 			     unsigned int flags);
1509 
1510 static struct dquot **ext4_get_dquots(struct inode *inode)
1511 {
1512 	return EXT4_I(inode)->i_dquot;
1513 }
1514 
1515 static const struct dquot_operations ext4_quota_operations = {
1516 	.get_reserved_space	= ext4_get_reserved_space,
1517 	.write_dquot		= ext4_write_dquot,
1518 	.acquire_dquot		= ext4_acquire_dquot,
1519 	.release_dquot		= ext4_release_dquot,
1520 	.mark_dirty		= ext4_mark_dquot_dirty,
1521 	.write_info		= ext4_write_info,
1522 	.alloc_dquot		= dquot_alloc,
1523 	.destroy_dquot		= dquot_destroy,
1524 	.get_projid		= ext4_get_projid,
1525 	.get_inode_usage	= ext4_get_inode_usage,
1526 	.get_next_id		= dquot_get_next_id,
1527 };
1528 
1529 static const struct quotactl_ops ext4_qctl_operations = {
1530 	.quota_on	= ext4_quota_on,
1531 	.quota_off	= ext4_quota_off,
1532 	.quota_sync	= dquot_quota_sync,
1533 	.get_state	= dquot_get_state,
1534 	.set_info	= dquot_set_dqinfo,
1535 	.get_dqblk	= dquot_get_dqblk,
1536 	.set_dqblk	= dquot_set_dqblk,
1537 	.get_nextdqblk	= dquot_get_next_dqblk,
1538 };
1539 #endif
1540 
1541 static const struct super_operations ext4_sops = {
1542 	.alloc_inode	= ext4_alloc_inode,
1543 	.free_inode	= ext4_free_in_core_inode,
1544 	.destroy_inode	= ext4_destroy_inode,
1545 	.write_inode	= ext4_write_inode,
1546 	.dirty_inode	= ext4_dirty_inode,
1547 	.drop_inode	= ext4_drop_inode,
1548 	.evict_inode	= ext4_evict_inode,
1549 	.put_super	= ext4_put_super,
1550 	.sync_fs	= ext4_sync_fs,
1551 	.freeze_fs	= ext4_freeze,
1552 	.unfreeze_fs	= ext4_unfreeze,
1553 	.statfs		= ext4_statfs,
1554 	.show_options	= ext4_show_options,
1555 #ifdef CONFIG_QUOTA
1556 	.quota_read	= ext4_quota_read,
1557 	.quota_write	= ext4_quota_write,
1558 	.get_dquots	= ext4_get_dquots,
1559 #endif
1560 };
1561 
1562 static const struct export_operations ext4_export_ops = {
1563 	.fh_to_dentry = ext4_fh_to_dentry,
1564 	.fh_to_parent = ext4_fh_to_parent,
1565 	.get_parent = ext4_get_parent,
1566 	.commit_metadata = ext4_nfs_commit_metadata,
1567 };
1568 
1569 enum {
1570 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1571 	Opt_resgid, Opt_resuid, Opt_sb,
1572 	Opt_nouid32, Opt_debug, Opt_removed,
1573 	Opt_user_xattr, Opt_acl,
1574 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1575 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1576 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1577 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1578 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1579 	Opt_inlinecrypt,
1580 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1581 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1582 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1583 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1584 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1585 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1586 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1587 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1588 	Opt_dioread_nolock, Opt_dioread_lock,
1589 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1590 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1591 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1592 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1593 #ifdef CONFIG_EXT4_DEBUG
1594 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1595 #endif
1596 };
1597 
1598 static const struct constant_table ext4_param_errors[] = {
1599 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1600 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1601 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1602 	{}
1603 };
1604 
1605 static const struct constant_table ext4_param_data[] = {
1606 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1607 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1608 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1609 	{}
1610 };
1611 
1612 static const struct constant_table ext4_param_data_err[] = {
1613 	{"abort",	Opt_data_err_abort},
1614 	{"ignore",	Opt_data_err_ignore},
1615 	{}
1616 };
1617 
1618 static const struct constant_table ext4_param_jqfmt[] = {
1619 	{"vfsold",	QFMT_VFS_OLD},
1620 	{"vfsv0",	QFMT_VFS_V0},
1621 	{"vfsv1",	QFMT_VFS_V1},
1622 	{}
1623 };
1624 
1625 static const struct constant_table ext4_param_dax[] = {
1626 	{"always",	Opt_dax_always},
1627 	{"inode",	Opt_dax_inode},
1628 	{"never",	Opt_dax_never},
1629 	{}
1630 };
1631 
1632 /* String parameter that allows empty argument */
1633 #define fsparam_string_empty(NAME, OPT) \
1634 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1635 
1636 /*
1637  * Mount option specification
1638  * We don't use fsparam_flag_no because of the way we set the
1639  * options and the way we show them in _ext4_show_options(). To
1640  * keep the changes to a minimum, let's keep the negative options
1641  * separate for now.
1642  */
1643 static const struct fs_parameter_spec ext4_param_specs[] = {
1644 	fsparam_flag	("bsddf",		Opt_bsd_df),
1645 	fsparam_flag	("minixdf",		Opt_minix_df),
1646 	fsparam_flag	("grpid",		Opt_grpid),
1647 	fsparam_flag	("bsdgroups",		Opt_grpid),
1648 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1649 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1650 	fsparam_u32	("resgid",		Opt_resgid),
1651 	fsparam_u32	("resuid",		Opt_resuid),
1652 	fsparam_u32	("sb",			Opt_sb),
1653 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1654 	fsparam_flag	("nouid32",		Opt_nouid32),
1655 	fsparam_flag	("debug",		Opt_debug),
1656 	fsparam_flag	("oldalloc",		Opt_removed),
1657 	fsparam_flag	("orlov",		Opt_removed),
1658 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1659 	fsparam_flag	("acl",			Opt_acl),
1660 	fsparam_flag	("norecovery",		Opt_noload),
1661 	fsparam_flag	("noload",		Opt_noload),
1662 	fsparam_flag	("bh",			Opt_removed),
1663 	fsparam_flag	("nobh",		Opt_removed),
1664 	fsparam_u32	("commit",		Opt_commit),
1665 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1666 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1667 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1668 	fsparam_bdev	("journal_path",	Opt_journal_path),
1669 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1670 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1671 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1672 	fsparam_flag	("abort",		Opt_abort),
1673 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1674 	fsparam_enum	("data_err",		Opt_data_err,
1675 						ext4_param_data_err),
1676 	fsparam_string_empty
1677 			("usrjquota",		Opt_usrjquota),
1678 	fsparam_string_empty
1679 			("grpjquota",		Opt_grpjquota),
1680 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1681 	fsparam_flag	("grpquota",		Opt_grpquota),
1682 	fsparam_flag	("quota",		Opt_quota),
1683 	fsparam_flag	("noquota",		Opt_noquota),
1684 	fsparam_flag	("usrquota",		Opt_usrquota),
1685 	fsparam_flag	("prjquota",		Opt_prjquota),
1686 	fsparam_flag	("barrier",		Opt_barrier),
1687 	fsparam_u32	("barrier",		Opt_barrier),
1688 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1689 	fsparam_flag	("i_version",		Opt_removed),
1690 	fsparam_flag	("dax",			Opt_dax),
1691 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1692 	fsparam_u32	("stripe",		Opt_stripe),
1693 	fsparam_flag	("delalloc",		Opt_delalloc),
1694 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1695 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1696 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1697 	fsparam_u32	("debug_want_extra_isize",
1698 						Opt_debug_want_extra_isize),
1699 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1700 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1701 	fsparam_flag	("block_validity",	Opt_block_validity),
1702 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1703 	fsparam_u32	("inode_readahead_blks",
1704 						Opt_inode_readahead_blks),
1705 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1706 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1707 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1708 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1709 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1710 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1711 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1712 	fsparam_flag	("discard",		Opt_discard),
1713 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1714 	fsparam_u32	("init_itable",		Opt_init_itable),
1715 	fsparam_flag	("init_itable",		Opt_init_itable),
1716 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1717 #ifdef CONFIG_EXT4_DEBUG
1718 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1719 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1720 #endif
1721 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1722 	fsparam_flag	("test_dummy_encryption",
1723 						Opt_test_dummy_encryption),
1724 	fsparam_string	("test_dummy_encryption",
1725 						Opt_test_dummy_encryption),
1726 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1727 	fsparam_flag	("nombcache",		Opt_nombcache),
1728 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1729 	fsparam_flag	("prefetch_block_bitmaps",
1730 						Opt_removed),
1731 	fsparam_flag	("no_prefetch_block_bitmaps",
1732 						Opt_no_prefetch_block_bitmaps),
1733 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1734 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1735 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1736 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1737 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1738 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1739 	{}
1740 };
1741 
1742 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1743 
1744 #define MOPT_SET	0x0001
1745 #define MOPT_CLEAR	0x0002
1746 #define MOPT_NOSUPPORT	0x0004
1747 #define MOPT_EXPLICIT	0x0008
1748 #ifdef CONFIG_QUOTA
1749 #define MOPT_Q		0
1750 #define MOPT_QFMT	0x0010
1751 #else
1752 #define MOPT_Q		MOPT_NOSUPPORT
1753 #define MOPT_QFMT	MOPT_NOSUPPORT
1754 #endif
1755 #define MOPT_NO_EXT2	0x0020
1756 #define MOPT_NO_EXT3	0x0040
1757 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1758 #define MOPT_SKIP	0x0080
1759 #define	MOPT_2		0x0100
1760 
1761 static const struct mount_opts {
1762 	int	token;
1763 	int	mount_opt;
1764 	int	flags;
1765 } ext4_mount_opts[] = {
1766 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1767 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1768 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1769 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1770 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1771 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1772 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1773 	 MOPT_EXT4_ONLY | MOPT_SET},
1774 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1775 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1776 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1777 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1778 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1779 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1780 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1781 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1782 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1783 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1784 	{Opt_commit, 0, MOPT_NO_EXT2},
1785 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1786 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1787 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1788 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1789 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1790 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1791 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1792 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1793 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1794 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1795 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1796 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1797 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1798 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1799 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1800 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1801 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1802 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1803 	{Opt_data, 0, MOPT_NO_EXT2},
1804 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1805 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1806 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1807 #else
1808 	{Opt_acl, 0, MOPT_NOSUPPORT},
1809 #endif
1810 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1811 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1812 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1813 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1814 							MOPT_SET | MOPT_Q},
1815 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1816 							MOPT_SET | MOPT_Q},
1817 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1818 							MOPT_SET | MOPT_Q},
1819 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1820 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1821 							MOPT_CLEAR | MOPT_Q},
1822 	{Opt_usrjquota, 0, MOPT_Q},
1823 	{Opt_grpjquota, 0, MOPT_Q},
1824 	{Opt_jqfmt, 0, MOPT_QFMT},
1825 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1826 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1827 	 MOPT_SET},
1828 #ifdef CONFIG_EXT4_DEBUG
1829 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1830 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1831 #endif
1832 	{Opt_err, 0, 0}
1833 };
1834 
1835 #if IS_ENABLED(CONFIG_UNICODE)
1836 static const struct ext4_sb_encodings {
1837 	__u16 magic;
1838 	char *name;
1839 	unsigned int version;
1840 } ext4_sb_encoding_map[] = {
1841 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1842 };
1843 
1844 static const struct ext4_sb_encodings *
1845 ext4_sb_read_encoding(const struct ext4_super_block *es)
1846 {
1847 	__u16 magic = le16_to_cpu(es->s_encoding);
1848 	int i;
1849 
1850 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1851 		if (magic == ext4_sb_encoding_map[i].magic)
1852 			return &ext4_sb_encoding_map[i];
1853 
1854 	return NULL;
1855 }
1856 #endif
1857 
1858 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1859 #define EXT4_SPEC_JQFMT				(1 <<  1)
1860 #define EXT4_SPEC_DATAJ				(1 <<  2)
1861 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1862 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1863 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1864 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1865 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1866 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1867 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1868 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1869 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1870 #define EXT4_SPEC_s_stripe			(1 << 13)
1871 #define EXT4_SPEC_s_resuid			(1 << 14)
1872 #define EXT4_SPEC_s_resgid			(1 << 15)
1873 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1874 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1875 #define EXT4_SPEC_s_sb_block			(1 << 18)
1876 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1877 
1878 struct ext4_fs_context {
1879 	char		*s_qf_names[EXT4_MAXQUOTAS];
1880 	struct fscrypt_dummy_policy dummy_enc_policy;
1881 	int		s_jquota_fmt;	/* Format of quota to use */
1882 #ifdef CONFIG_EXT4_DEBUG
1883 	int s_fc_debug_max_replay;
1884 #endif
1885 	unsigned short	qname_spec;
1886 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1887 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1888 	unsigned long	journal_devnum;
1889 	unsigned long	s_commit_interval;
1890 	unsigned long	s_stripe;
1891 	unsigned int	s_inode_readahead_blks;
1892 	unsigned int	s_want_extra_isize;
1893 	unsigned int	s_li_wait_mult;
1894 	unsigned int	s_max_dir_size_kb;
1895 	unsigned int	journal_ioprio;
1896 	unsigned int	vals_s_mount_opt;
1897 	unsigned int	mask_s_mount_opt;
1898 	unsigned int	vals_s_mount_opt2;
1899 	unsigned int	mask_s_mount_opt2;
1900 	unsigned long	vals_s_mount_flags;
1901 	unsigned long	mask_s_mount_flags;
1902 	unsigned int	opt_flags;	/* MOPT flags */
1903 	unsigned int	spec;
1904 	u32		s_max_batch_time;
1905 	u32		s_min_batch_time;
1906 	kuid_t		s_resuid;
1907 	kgid_t		s_resgid;
1908 	ext4_fsblk_t	s_sb_block;
1909 };
1910 
1911 static void ext4_fc_free(struct fs_context *fc)
1912 {
1913 	struct ext4_fs_context *ctx = fc->fs_private;
1914 	int i;
1915 
1916 	if (!ctx)
1917 		return;
1918 
1919 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1920 		kfree(ctx->s_qf_names[i]);
1921 
1922 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1923 	kfree(ctx);
1924 }
1925 
1926 int ext4_init_fs_context(struct fs_context *fc)
1927 {
1928 	struct ext4_fs_context *ctx;
1929 
1930 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1931 	if (!ctx)
1932 		return -ENOMEM;
1933 
1934 	fc->fs_private = ctx;
1935 	fc->ops = &ext4_context_ops;
1936 
1937 	return 0;
1938 }
1939 
1940 #ifdef CONFIG_QUOTA
1941 /*
1942  * Note the name of the specified quota file.
1943  */
1944 static int note_qf_name(struct fs_context *fc, int qtype,
1945 		       struct fs_parameter *param)
1946 {
1947 	struct ext4_fs_context *ctx = fc->fs_private;
1948 	char *qname;
1949 
1950 	if (param->size < 1) {
1951 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
1952 		return -EINVAL;
1953 	}
1954 	if (strchr(param->string, '/')) {
1955 		ext4_msg(NULL, KERN_ERR,
1956 			 "quotafile must be on filesystem root");
1957 		return -EINVAL;
1958 	}
1959 	if (ctx->s_qf_names[qtype]) {
1960 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
1961 			ext4_msg(NULL, KERN_ERR,
1962 				 "%s quota file already specified",
1963 				 QTYPE2NAME(qtype));
1964 			return -EINVAL;
1965 		}
1966 		return 0;
1967 	}
1968 
1969 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
1970 	if (!qname) {
1971 		ext4_msg(NULL, KERN_ERR,
1972 			 "Not enough memory for storing quotafile name");
1973 		return -ENOMEM;
1974 	}
1975 	ctx->s_qf_names[qtype] = qname;
1976 	ctx->qname_spec |= 1 << qtype;
1977 	ctx->spec |= EXT4_SPEC_JQUOTA;
1978 	return 0;
1979 }
1980 
1981 /*
1982  * Clear the name of the specified quota file.
1983  */
1984 static int unnote_qf_name(struct fs_context *fc, int qtype)
1985 {
1986 	struct ext4_fs_context *ctx = fc->fs_private;
1987 
1988 	if (ctx->s_qf_names[qtype])
1989 		kfree(ctx->s_qf_names[qtype]);
1990 
1991 	ctx->s_qf_names[qtype] = NULL;
1992 	ctx->qname_spec |= 1 << qtype;
1993 	ctx->spec |= EXT4_SPEC_JQUOTA;
1994 	return 0;
1995 }
1996 #endif
1997 
1998 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
1999 					    struct ext4_fs_context *ctx)
2000 {
2001 	int err;
2002 
2003 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2004 		ext4_msg(NULL, KERN_WARNING,
2005 			 "test_dummy_encryption option not supported");
2006 		return -EINVAL;
2007 	}
2008 	err = fscrypt_parse_test_dummy_encryption(param,
2009 						  &ctx->dummy_enc_policy);
2010 	if (err == -EINVAL) {
2011 		ext4_msg(NULL, KERN_WARNING,
2012 			 "Value of option \"%s\" is unrecognized", param->key);
2013 	} else if (err == -EEXIST) {
2014 		ext4_msg(NULL, KERN_WARNING,
2015 			 "Conflicting test_dummy_encryption options");
2016 		return -EINVAL;
2017 	}
2018 	return err;
2019 }
2020 
2021 #define EXT4_SET_CTX(name)						\
2022 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2023 				  unsigned long flag)			\
2024 {									\
2025 	ctx->mask_s_##name |= flag;					\
2026 	ctx->vals_s_##name |= flag;					\
2027 }
2028 
2029 #define EXT4_CLEAR_CTX(name)						\
2030 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2031 				    unsigned long flag)			\
2032 {									\
2033 	ctx->mask_s_##name |= flag;					\
2034 	ctx->vals_s_##name &= ~flag;					\
2035 }
2036 
2037 #define EXT4_TEST_CTX(name)						\
2038 static inline unsigned long						\
2039 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2040 {									\
2041 	return (ctx->vals_s_##name & flag);				\
2042 }
2043 
2044 EXT4_SET_CTX(flags); /* set only */
2045 EXT4_SET_CTX(mount_opt);
2046 EXT4_CLEAR_CTX(mount_opt);
2047 EXT4_TEST_CTX(mount_opt);
2048 EXT4_SET_CTX(mount_opt2);
2049 EXT4_CLEAR_CTX(mount_opt2);
2050 EXT4_TEST_CTX(mount_opt2);
2051 
2052 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2053 {
2054 	set_bit(bit, &ctx->mask_s_mount_flags);
2055 	set_bit(bit, &ctx->vals_s_mount_flags);
2056 }
2057 
2058 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2059 {
2060 	struct ext4_fs_context *ctx = fc->fs_private;
2061 	struct fs_parse_result result;
2062 	const struct mount_opts *m;
2063 	int is_remount;
2064 	kuid_t uid;
2065 	kgid_t gid;
2066 	int token;
2067 
2068 	token = fs_parse(fc, ext4_param_specs, param, &result);
2069 	if (token < 0)
2070 		return token;
2071 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2072 
2073 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2074 		if (token == m->token)
2075 			break;
2076 
2077 	ctx->opt_flags |= m->flags;
2078 
2079 	if (m->flags & MOPT_EXPLICIT) {
2080 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2081 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2082 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2083 			ctx_set_mount_opt2(ctx,
2084 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2085 		} else
2086 			return -EINVAL;
2087 	}
2088 
2089 	if (m->flags & MOPT_NOSUPPORT) {
2090 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2091 			 param->key);
2092 		return 0;
2093 	}
2094 
2095 	switch (token) {
2096 #ifdef CONFIG_QUOTA
2097 	case Opt_usrjquota:
2098 		if (!*param->string)
2099 			return unnote_qf_name(fc, USRQUOTA);
2100 		else
2101 			return note_qf_name(fc, USRQUOTA, param);
2102 	case Opt_grpjquota:
2103 		if (!*param->string)
2104 			return unnote_qf_name(fc, GRPQUOTA);
2105 		else
2106 			return note_qf_name(fc, GRPQUOTA, param);
2107 #endif
2108 	case Opt_sb:
2109 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2110 			ext4_msg(NULL, KERN_WARNING,
2111 				 "Ignoring %s option on remount", param->key);
2112 		} else {
2113 			ctx->s_sb_block = result.uint_32;
2114 			ctx->spec |= EXT4_SPEC_s_sb_block;
2115 		}
2116 		return 0;
2117 	case Opt_removed:
2118 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2119 			 param->key);
2120 		return 0;
2121 	case Opt_abort:
2122 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2123 		return 0;
2124 	case Opt_inlinecrypt:
2125 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2126 		ctx_set_flags(ctx, SB_INLINECRYPT);
2127 #else
2128 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2129 #endif
2130 		return 0;
2131 	case Opt_errors:
2132 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2133 		ctx_set_mount_opt(ctx, result.uint_32);
2134 		return 0;
2135 #ifdef CONFIG_QUOTA
2136 	case Opt_jqfmt:
2137 		ctx->s_jquota_fmt = result.uint_32;
2138 		ctx->spec |= EXT4_SPEC_JQFMT;
2139 		return 0;
2140 #endif
2141 	case Opt_data:
2142 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2143 		ctx_set_mount_opt(ctx, result.uint_32);
2144 		ctx->spec |= EXT4_SPEC_DATAJ;
2145 		return 0;
2146 	case Opt_commit:
2147 		if (result.uint_32 == 0)
2148 			ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2149 		else if (result.uint_32 > INT_MAX / HZ) {
2150 			ext4_msg(NULL, KERN_ERR,
2151 				 "Invalid commit interval %d, "
2152 				 "must be smaller than %d",
2153 				 result.uint_32, INT_MAX / HZ);
2154 			return -EINVAL;
2155 		}
2156 		ctx->s_commit_interval = HZ * result.uint_32;
2157 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2158 		return 0;
2159 	case Opt_debug_want_extra_isize:
2160 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2161 			ext4_msg(NULL, KERN_ERR,
2162 				 "Invalid want_extra_isize %d", result.uint_32);
2163 			return -EINVAL;
2164 		}
2165 		ctx->s_want_extra_isize = result.uint_32;
2166 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2167 		return 0;
2168 	case Opt_max_batch_time:
2169 		ctx->s_max_batch_time = result.uint_32;
2170 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2171 		return 0;
2172 	case Opt_min_batch_time:
2173 		ctx->s_min_batch_time = result.uint_32;
2174 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2175 		return 0;
2176 	case Opt_inode_readahead_blks:
2177 		if (result.uint_32 &&
2178 		    (result.uint_32 > (1 << 30) ||
2179 		     !is_power_of_2(result.uint_32))) {
2180 			ext4_msg(NULL, KERN_ERR,
2181 				 "EXT4-fs: inode_readahead_blks must be "
2182 				 "0 or a power of 2 smaller than 2^31");
2183 			return -EINVAL;
2184 		}
2185 		ctx->s_inode_readahead_blks = result.uint_32;
2186 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2187 		return 0;
2188 	case Opt_init_itable:
2189 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2190 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2191 		if (param->type == fs_value_is_string)
2192 			ctx->s_li_wait_mult = result.uint_32;
2193 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2194 		return 0;
2195 	case Opt_max_dir_size_kb:
2196 		ctx->s_max_dir_size_kb = result.uint_32;
2197 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2198 		return 0;
2199 #ifdef CONFIG_EXT4_DEBUG
2200 	case Opt_fc_debug_max_replay:
2201 		ctx->s_fc_debug_max_replay = result.uint_32;
2202 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2203 		return 0;
2204 #endif
2205 	case Opt_stripe:
2206 		ctx->s_stripe = result.uint_32;
2207 		ctx->spec |= EXT4_SPEC_s_stripe;
2208 		return 0;
2209 	case Opt_resuid:
2210 		uid = make_kuid(current_user_ns(), result.uint_32);
2211 		if (!uid_valid(uid)) {
2212 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2213 				 result.uint_32);
2214 			return -EINVAL;
2215 		}
2216 		ctx->s_resuid = uid;
2217 		ctx->spec |= EXT4_SPEC_s_resuid;
2218 		return 0;
2219 	case Opt_resgid:
2220 		gid = make_kgid(current_user_ns(), result.uint_32);
2221 		if (!gid_valid(gid)) {
2222 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2223 				 result.uint_32);
2224 			return -EINVAL;
2225 		}
2226 		ctx->s_resgid = gid;
2227 		ctx->spec |= EXT4_SPEC_s_resgid;
2228 		return 0;
2229 	case Opt_journal_dev:
2230 		if (is_remount) {
2231 			ext4_msg(NULL, KERN_ERR,
2232 				 "Cannot specify journal on remount");
2233 			return -EINVAL;
2234 		}
2235 		ctx->journal_devnum = result.uint_32;
2236 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2237 		return 0;
2238 	case Opt_journal_path:
2239 	{
2240 		struct inode *journal_inode;
2241 		struct path path;
2242 		int error;
2243 
2244 		if (is_remount) {
2245 			ext4_msg(NULL, KERN_ERR,
2246 				 "Cannot specify journal on remount");
2247 			return -EINVAL;
2248 		}
2249 
2250 		error = fs_lookup_param(fc, param, 1, &path);
2251 		if (error) {
2252 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2253 				 "journal device path");
2254 			return -EINVAL;
2255 		}
2256 
2257 		journal_inode = d_inode(path.dentry);
2258 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2259 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2260 		path_put(&path);
2261 		return 0;
2262 	}
2263 	case Opt_journal_ioprio:
2264 		if (result.uint_32 > 7) {
2265 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2266 				 " (must be 0-7)");
2267 			return -EINVAL;
2268 		}
2269 		ctx->journal_ioprio =
2270 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2271 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2272 		return 0;
2273 	case Opt_test_dummy_encryption:
2274 		return ext4_parse_test_dummy_encryption(param, ctx);
2275 	case Opt_dax:
2276 	case Opt_dax_type:
2277 #ifdef CONFIG_FS_DAX
2278 	{
2279 		int type = (token == Opt_dax) ?
2280 			   Opt_dax : result.uint_32;
2281 
2282 		switch (type) {
2283 		case Opt_dax:
2284 		case Opt_dax_always:
2285 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2286 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2287 			break;
2288 		case Opt_dax_never:
2289 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2290 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2291 			break;
2292 		case Opt_dax_inode:
2293 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2294 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2295 			/* Strictly for printing options */
2296 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2297 			break;
2298 		}
2299 		return 0;
2300 	}
2301 #else
2302 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2303 		return -EINVAL;
2304 #endif
2305 	case Opt_data_err:
2306 		if (result.uint_32 == Opt_data_err_abort)
2307 			ctx_set_mount_opt(ctx, m->mount_opt);
2308 		else if (result.uint_32 == Opt_data_err_ignore)
2309 			ctx_clear_mount_opt(ctx, m->mount_opt);
2310 		return 0;
2311 	case Opt_mb_optimize_scan:
2312 		if (result.int_32 == 1) {
2313 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2314 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2315 		} else if (result.int_32 == 0) {
2316 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2317 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2318 		} else {
2319 			ext4_msg(NULL, KERN_WARNING,
2320 				 "mb_optimize_scan should be set to 0 or 1.");
2321 			return -EINVAL;
2322 		}
2323 		return 0;
2324 	}
2325 
2326 	/*
2327 	 * At this point we should only be getting options requiring MOPT_SET,
2328 	 * or MOPT_CLEAR. Anything else is a bug
2329 	 */
2330 	if (m->token == Opt_err) {
2331 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2332 			 param->key);
2333 		WARN_ON(1);
2334 		return -EINVAL;
2335 	}
2336 
2337 	else {
2338 		unsigned int set = 0;
2339 
2340 		if ((param->type == fs_value_is_flag) ||
2341 		    result.uint_32 > 0)
2342 			set = 1;
2343 
2344 		if (m->flags & MOPT_CLEAR)
2345 			set = !set;
2346 		else if (unlikely(!(m->flags & MOPT_SET))) {
2347 			ext4_msg(NULL, KERN_WARNING,
2348 				 "buggy handling of option %s",
2349 				 param->key);
2350 			WARN_ON(1);
2351 			return -EINVAL;
2352 		}
2353 		if (m->flags & MOPT_2) {
2354 			if (set != 0)
2355 				ctx_set_mount_opt2(ctx, m->mount_opt);
2356 			else
2357 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2358 		} else {
2359 			if (set != 0)
2360 				ctx_set_mount_opt(ctx, m->mount_opt);
2361 			else
2362 				ctx_clear_mount_opt(ctx, m->mount_opt);
2363 		}
2364 	}
2365 
2366 	return 0;
2367 }
2368 
2369 static int parse_options(struct fs_context *fc, char *options)
2370 {
2371 	struct fs_parameter param;
2372 	int ret;
2373 	char *key;
2374 
2375 	if (!options)
2376 		return 0;
2377 
2378 	while ((key = strsep(&options, ",")) != NULL) {
2379 		if (*key) {
2380 			size_t v_len = 0;
2381 			char *value = strchr(key, '=');
2382 
2383 			param.type = fs_value_is_flag;
2384 			param.string = NULL;
2385 
2386 			if (value) {
2387 				if (value == key)
2388 					continue;
2389 
2390 				*value++ = 0;
2391 				v_len = strlen(value);
2392 				param.string = kmemdup_nul(value, v_len,
2393 							   GFP_KERNEL);
2394 				if (!param.string)
2395 					return -ENOMEM;
2396 				param.type = fs_value_is_string;
2397 			}
2398 
2399 			param.key = key;
2400 			param.size = v_len;
2401 
2402 			ret = ext4_parse_param(fc, &param);
2403 			if (param.string)
2404 				kfree(param.string);
2405 			if (ret < 0)
2406 				return ret;
2407 		}
2408 	}
2409 
2410 	ret = ext4_validate_options(fc);
2411 	if (ret < 0)
2412 		return ret;
2413 
2414 	return 0;
2415 }
2416 
2417 static int parse_apply_sb_mount_options(struct super_block *sb,
2418 					struct ext4_fs_context *m_ctx)
2419 {
2420 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2421 	char *s_mount_opts = NULL;
2422 	struct ext4_fs_context *s_ctx = NULL;
2423 	struct fs_context *fc = NULL;
2424 	int ret = -ENOMEM;
2425 
2426 	if (!sbi->s_es->s_mount_opts[0])
2427 		return 0;
2428 
2429 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2430 				sizeof(sbi->s_es->s_mount_opts),
2431 				GFP_KERNEL);
2432 	if (!s_mount_opts)
2433 		return ret;
2434 
2435 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2436 	if (!fc)
2437 		goto out_free;
2438 
2439 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2440 	if (!s_ctx)
2441 		goto out_free;
2442 
2443 	fc->fs_private = s_ctx;
2444 	fc->s_fs_info = sbi;
2445 
2446 	ret = parse_options(fc, s_mount_opts);
2447 	if (ret < 0)
2448 		goto parse_failed;
2449 
2450 	ret = ext4_check_opt_consistency(fc, sb);
2451 	if (ret < 0) {
2452 parse_failed:
2453 		ext4_msg(sb, KERN_WARNING,
2454 			 "failed to parse options in superblock: %s",
2455 			 s_mount_opts);
2456 		ret = 0;
2457 		goto out_free;
2458 	}
2459 
2460 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2461 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2462 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2463 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2464 
2465 	ext4_apply_options(fc, sb);
2466 	ret = 0;
2467 
2468 out_free:
2469 	if (fc) {
2470 		ext4_fc_free(fc);
2471 		kfree(fc);
2472 	}
2473 	kfree(s_mount_opts);
2474 	return ret;
2475 }
2476 
2477 static void ext4_apply_quota_options(struct fs_context *fc,
2478 				     struct super_block *sb)
2479 {
2480 #ifdef CONFIG_QUOTA
2481 	bool quota_feature = ext4_has_feature_quota(sb);
2482 	struct ext4_fs_context *ctx = fc->fs_private;
2483 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2484 	char *qname;
2485 	int i;
2486 
2487 	if (quota_feature)
2488 		return;
2489 
2490 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2491 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2492 			if (!(ctx->qname_spec & (1 << i)))
2493 				continue;
2494 
2495 			qname = ctx->s_qf_names[i]; /* May be NULL */
2496 			if (qname)
2497 				set_opt(sb, QUOTA);
2498 			ctx->s_qf_names[i] = NULL;
2499 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2500 						lockdep_is_held(&sb->s_umount));
2501 			if (qname)
2502 				kfree_rcu(qname);
2503 		}
2504 	}
2505 
2506 	if (ctx->spec & EXT4_SPEC_JQFMT)
2507 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2508 #endif
2509 }
2510 
2511 /*
2512  * Check quota settings consistency.
2513  */
2514 static int ext4_check_quota_consistency(struct fs_context *fc,
2515 					struct super_block *sb)
2516 {
2517 #ifdef CONFIG_QUOTA
2518 	struct ext4_fs_context *ctx = fc->fs_private;
2519 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2520 	bool quota_feature = ext4_has_feature_quota(sb);
2521 	bool quota_loaded = sb_any_quota_loaded(sb);
2522 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2523 	int quota_flags, i;
2524 
2525 	/*
2526 	 * We do the test below only for project quotas. 'usrquota' and
2527 	 * 'grpquota' mount options are allowed even without quota feature
2528 	 * to support legacy quotas in quota files.
2529 	 */
2530 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2531 	    !ext4_has_feature_project(sb)) {
2532 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2533 			 "Cannot enable project quota enforcement.");
2534 		return -EINVAL;
2535 	}
2536 
2537 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2538 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2539 	if (quota_loaded &&
2540 	    ctx->mask_s_mount_opt & quota_flags &&
2541 	    !ctx_test_mount_opt(ctx, quota_flags))
2542 		goto err_quota_change;
2543 
2544 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2545 
2546 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2547 			if (!(ctx->qname_spec & (1 << i)))
2548 				continue;
2549 
2550 			if (quota_loaded &&
2551 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2552 				goto err_jquota_change;
2553 
2554 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2555 			    strcmp(get_qf_name(sb, sbi, i),
2556 				   ctx->s_qf_names[i]) != 0)
2557 				goto err_jquota_specified;
2558 		}
2559 
2560 		if (quota_feature) {
2561 			ext4_msg(NULL, KERN_INFO,
2562 				 "Journaled quota options ignored when "
2563 				 "QUOTA feature is enabled");
2564 			return 0;
2565 		}
2566 	}
2567 
2568 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2569 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2570 			goto err_jquota_change;
2571 		if (quota_feature) {
2572 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2573 				 "ignored when QUOTA feature is enabled");
2574 			return 0;
2575 		}
2576 	}
2577 
2578 	/* Make sure we don't mix old and new quota format */
2579 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2580 		       ctx->s_qf_names[USRQUOTA]);
2581 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2582 		       ctx->s_qf_names[GRPQUOTA]);
2583 
2584 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2585 		    test_opt(sb, USRQUOTA));
2586 
2587 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2588 		    test_opt(sb, GRPQUOTA));
2589 
2590 	if (usr_qf_name) {
2591 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2592 		usrquota = false;
2593 	}
2594 	if (grp_qf_name) {
2595 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2596 		grpquota = false;
2597 	}
2598 
2599 	if (usr_qf_name || grp_qf_name) {
2600 		if (usrquota || grpquota) {
2601 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2602 				 "format mixing");
2603 			return -EINVAL;
2604 		}
2605 
2606 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2607 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2608 				 "not specified");
2609 			return -EINVAL;
2610 		}
2611 	}
2612 
2613 	return 0;
2614 
2615 err_quota_change:
2616 	ext4_msg(NULL, KERN_ERR,
2617 		 "Cannot change quota options when quota turned on");
2618 	return -EINVAL;
2619 err_jquota_change:
2620 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2621 		 "options when quota turned on");
2622 	return -EINVAL;
2623 err_jquota_specified:
2624 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2625 		 QTYPE2NAME(i));
2626 	return -EINVAL;
2627 #else
2628 	return 0;
2629 #endif
2630 }
2631 
2632 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2633 					    struct super_block *sb)
2634 {
2635 	const struct ext4_fs_context *ctx = fc->fs_private;
2636 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2637 	int err;
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 	/*
2671 	 * fscrypt_add_test_dummy_key() technically changes the super_block, so
2672 	 * technically it should be delayed until ext4_apply_options() like the
2673 	 * other changes.  But since we never get here for remounts (see above),
2674 	 * and this is the last chance to report errors, we do it here.
2675 	 */
2676 	err = fscrypt_add_test_dummy_key(sb, &ctx->dummy_enc_policy);
2677 	if (err)
2678 		ext4_msg(NULL, KERN_WARNING,
2679 			 "Error adding test dummy encryption key [%d]", err);
2680 	return err;
2681 }
2682 
2683 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2684 					     struct super_block *sb)
2685 {
2686 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2687 	    /* if already set, it was already verified to be the same */
2688 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2689 		return;
2690 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2691 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2692 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2693 }
2694 
2695 static int ext4_check_opt_consistency(struct fs_context *fc,
2696 				      struct super_block *sb)
2697 {
2698 	struct ext4_fs_context *ctx = fc->fs_private;
2699 	struct ext4_sb_info *sbi = fc->s_fs_info;
2700 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2701 	int err;
2702 
2703 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2704 		ext4_msg(NULL, KERN_ERR,
2705 			 "Mount option(s) incompatible with ext2");
2706 		return -EINVAL;
2707 	}
2708 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2709 		ext4_msg(NULL, KERN_ERR,
2710 			 "Mount option(s) incompatible with ext3");
2711 		return -EINVAL;
2712 	}
2713 
2714 	if (ctx->s_want_extra_isize >
2715 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2716 		ext4_msg(NULL, KERN_ERR,
2717 			 "Invalid want_extra_isize %d",
2718 			 ctx->s_want_extra_isize);
2719 		return -EINVAL;
2720 	}
2721 
2722 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2723 		int blocksize =
2724 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2725 		if (blocksize < PAGE_SIZE)
2726 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2727 				 "experimental mount option 'dioread_nolock' "
2728 				 "for blocksize < PAGE_SIZE");
2729 	}
2730 
2731 	err = ext4_check_test_dummy_encryption(fc, sb);
2732 	if (err)
2733 		return err;
2734 
2735 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2736 		if (!sbi->s_journal) {
2737 			ext4_msg(NULL, KERN_WARNING,
2738 				 "Remounting file system with no journal "
2739 				 "so ignoring journalled data option");
2740 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2741 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2742 			   test_opt(sb, DATA_FLAGS)) {
2743 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2744 				 "on remount");
2745 			return -EINVAL;
2746 		}
2747 	}
2748 
2749 	if (is_remount) {
2750 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2751 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2752 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2753 				 "both data=journal and dax");
2754 			return -EINVAL;
2755 		}
2756 
2757 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2758 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2759 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2760 fail_dax_change_remount:
2761 			ext4_msg(NULL, KERN_ERR, "can't change "
2762 				 "dax mount option while remounting");
2763 			return -EINVAL;
2764 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2765 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2766 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2767 			goto fail_dax_change_remount;
2768 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2769 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2770 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2771 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2772 			goto fail_dax_change_remount;
2773 		}
2774 	}
2775 
2776 	return ext4_check_quota_consistency(fc, sb);
2777 }
2778 
2779 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2780 {
2781 	struct ext4_fs_context *ctx = fc->fs_private;
2782 	struct ext4_sb_info *sbi = fc->s_fs_info;
2783 
2784 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2785 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2786 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2787 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2788 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2789 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2790 	sb->s_flags &= ~ctx->mask_s_flags;
2791 	sb->s_flags |= ctx->vals_s_flags;
2792 
2793 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2794 	APPLY(s_commit_interval);
2795 	APPLY(s_stripe);
2796 	APPLY(s_max_batch_time);
2797 	APPLY(s_min_batch_time);
2798 	APPLY(s_want_extra_isize);
2799 	APPLY(s_inode_readahead_blks);
2800 	APPLY(s_max_dir_size_kb);
2801 	APPLY(s_li_wait_mult);
2802 	APPLY(s_resgid);
2803 	APPLY(s_resuid);
2804 
2805 #ifdef CONFIG_EXT4_DEBUG
2806 	APPLY(s_fc_debug_max_replay);
2807 #endif
2808 
2809 	ext4_apply_quota_options(fc, sb);
2810 	ext4_apply_test_dummy_encryption(ctx, sb);
2811 }
2812 
2813 
2814 static int ext4_validate_options(struct fs_context *fc)
2815 {
2816 #ifdef CONFIG_QUOTA
2817 	struct ext4_fs_context *ctx = fc->fs_private;
2818 	char *usr_qf_name, *grp_qf_name;
2819 
2820 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2821 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2822 
2823 	if (usr_qf_name || grp_qf_name) {
2824 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2825 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2826 
2827 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2828 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2829 
2830 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2831 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2832 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2833 				 "format mixing");
2834 			return -EINVAL;
2835 		}
2836 	}
2837 #endif
2838 	return 1;
2839 }
2840 
2841 static inline void ext4_show_quota_options(struct seq_file *seq,
2842 					   struct super_block *sb)
2843 {
2844 #if defined(CONFIG_QUOTA)
2845 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2846 	char *usr_qf_name, *grp_qf_name;
2847 
2848 	if (sbi->s_jquota_fmt) {
2849 		char *fmtname = "";
2850 
2851 		switch (sbi->s_jquota_fmt) {
2852 		case QFMT_VFS_OLD:
2853 			fmtname = "vfsold";
2854 			break;
2855 		case QFMT_VFS_V0:
2856 			fmtname = "vfsv0";
2857 			break;
2858 		case QFMT_VFS_V1:
2859 			fmtname = "vfsv1";
2860 			break;
2861 		}
2862 		seq_printf(seq, ",jqfmt=%s", fmtname);
2863 	}
2864 
2865 	rcu_read_lock();
2866 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2867 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2868 	if (usr_qf_name)
2869 		seq_show_option(seq, "usrjquota", usr_qf_name);
2870 	if (grp_qf_name)
2871 		seq_show_option(seq, "grpjquota", grp_qf_name);
2872 	rcu_read_unlock();
2873 #endif
2874 }
2875 
2876 static const char *token2str(int token)
2877 {
2878 	const struct fs_parameter_spec *spec;
2879 
2880 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2881 		if (spec->opt == token && !spec->type)
2882 			break;
2883 	return spec->name;
2884 }
2885 
2886 /*
2887  * Show an option if
2888  *  - it's set to a non-default value OR
2889  *  - if the per-sb default is different from the global default
2890  */
2891 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2892 			      int nodefs)
2893 {
2894 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2895 	struct ext4_super_block *es = sbi->s_es;
2896 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2897 	const struct mount_opts *m;
2898 	char sep = nodefs ? '\n' : ',';
2899 
2900 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2901 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2902 
2903 	if (sbi->s_sb_block != 1)
2904 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2905 
2906 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2907 		int want_set = m->flags & MOPT_SET;
2908 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2909 		    m->flags & MOPT_SKIP)
2910 			continue;
2911 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2912 			continue; /* skip if same as the default */
2913 		if ((want_set &&
2914 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2915 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2916 			continue; /* select Opt_noFoo vs Opt_Foo */
2917 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2918 	}
2919 
2920 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2921 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2922 		SEQ_OPTS_PRINT("resuid=%u",
2923 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2924 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2925 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2926 		SEQ_OPTS_PRINT("resgid=%u",
2927 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2928 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2929 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2930 		SEQ_OPTS_PUTS("errors=remount-ro");
2931 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2932 		SEQ_OPTS_PUTS("errors=continue");
2933 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2934 		SEQ_OPTS_PUTS("errors=panic");
2935 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2936 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2937 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2938 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2939 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2940 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2941 	if (nodefs || sbi->s_stripe)
2942 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2943 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2944 			(sbi->s_mount_opt ^ def_mount_opt)) {
2945 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2946 			SEQ_OPTS_PUTS("data=journal");
2947 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2948 			SEQ_OPTS_PUTS("data=ordered");
2949 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2950 			SEQ_OPTS_PUTS("data=writeback");
2951 	}
2952 	if (nodefs ||
2953 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2954 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2955 			       sbi->s_inode_readahead_blks);
2956 
2957 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2958 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2959 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2960 	if (nodefs || sbi->s_max_dir_size_kb)
2961 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2962 	if (test_opt(sb, DATA_ERR_ABORT))
2963 		SEQ_OPTS_PUTS("data_err=abort");
2964 
2965 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2966 
2967 	if (sb->s_flags & SB_INLINECRYPT)
2968 		SEQ_OPTS_PUTS("inlinecrypt");
2969 
2970 	if (test_opt(sb, DAX_ALWAYS)) {
2971 		if (IS_EXT2_SB(sb))
2972 			SEQ_OPTS_PUTS("dax");
2973 		else
2974 			SEQ_OPTS_PUTS("dax=always");
2975 	} else if (test_opt2(sb, DAX_NEVER)) {
2976 		SEQ_OPTS_PUTS("dax=never");
2977 	} else if (test_opt2(sb, DAX_INODE)) {
2978 		SEQ_OPTS_PUTS("dax=inode");
2979 	}
2980 
2981 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
2982 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
2983 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
2984 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
2985 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
2986 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
2987 	}
2988 
2989 	ext4_show_quota_options(seq, sb);
2990 	return 0;
2991 }
2992 
2993 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2994 {
2995 	return _ext4_show_options(seq, root->d_sb, 0);
2996 }
2997 
2998 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2999 {
3000 	struct super_block *sb = seq->private;
3001 	int rc;
3002 
3003 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3004 	rc = _ext4_show_options(seq, sb, 1);
3005 	seq_puts(seq, "\n");
3006 	return rc;
3007 }
3008 
3009 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3010 			    int read_only)
3011 {
3012 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3013 	int err = 0;
3014 
3015 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3016 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3017 			 "forcing read-only mode");
3018 		err = -EROFS;
3019 		goto done;
3020 	}
3021 	if (read_only)
3022 		goto done;
3023 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3024 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3025 			 "running e2fsck is recommended");
3026 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3027 		ext4_msg(sb, KERN_WARNING,
3028 			 "warning: mounting fs with errors, "
3029 			 "running e2fsck is recommended");
3030 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3031 		 le16_to_cpu(es->s_mnt_count) >=
3032 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3033 		ext4_msg(sb, KERN_WARNING,
3034 			 "warning: maximal mount count reached, "
3035 			 "running e2fsck is recommended");
3036 	else if (le32_to_cpu(es->s_checkinterval) &&
3037 		 (ext4_get_tstamp(es, s_lastcheck) +
3038 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3039 		ext4_msg(sb, KERN_WARNING,
3040 			 "warning: checktime reached, "
3041 			 "running e2fsck is recommended");
3042 	if (!sbi->s_journal)
3043 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3044 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3045 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3046 	le16_add_cpu(&es->s_mnt_count, 1);
3047 	ext4_update_tstamp(es, s_mtime);
3048 	if (sbi->s_journal) {
3049 		ext4_set_feature_journal_needs_recovery(sb);
3050 		if (ext4_has_feature_orphan_file(sb))
3051 			ext4_set_feature_orphan_present(sb);
3052 	}
3053 
3054 	err = ext4_commit_super(sb);
3055 done:
3056 	if (test_opt(sb, DEBUG))
3057 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3058 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3059 			sb->s_blocksize,
3060 			sbi->s_groups_count,
3061 			EXT4_BLOCKS_PER_GROUP(sb),
3062 			EXT4_INODES_PER_GROUP(sb),
3063 			sbi->s_mount_opt, sbi->s_mount_opt2);
3064 	return err;
3065 }
3066 
3067 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3068 {
3069 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3070 	struct flex_groups **old_groups, **new_groups;
3071 	int size, i, j;
3072 
3073 	if (!sbi->s_log_groups_per_flex)
3074 		return 0;
3075 
3076 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3077 	if (size <= sbi->s_flex_groups_allocated)
3078 		return 0;
3079 
3080 	new_groups = kvzalloc(roundup_pow_of_two(size *
3081 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3082 	if (!new_groups) {
3083 		ext4_msg(sb, KERN_ERR,
3084 			 "not enough memory for %d flex group pointers", size);
3085 		return -ENOMEM;
3086 	}
3087 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3088 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3089 					 sizeof(struct flex_groups)),
3090 					 GFP_KERNEL);
3091 		if (!new_groups[i]) {
3092 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3093 				kvfree(new_groups[j]);
3094 			kvfree(new_groups);
3095 			ext4_msg(sb, KERN_ERR,
3096 				 "not enough memory for %d flex groups", size);
3097 			return -ENOMEM;
3098 		}
3099 	}
3100 	rcu_read_lock();
3101 	old_groups = rcu_dereference(sbi->s_flex_groups);
3102 	if (old_groups)
3103 		memcpy(new_groups, old_groups,
3104 		       (sbi->s_flex_groups_allocated *
3105 			sizeof(struct flex_groups *)));
3106 	rcu_read_unlock();
3107 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3108 	sbi->s_flex_groups_allocated = size;
3109 	if (old_groups)
3110 		ext4_kvfree_array_rcu(old_groups);
3111 	return 0;
3112 }
3113 
3114 static int ext4_fill_flex_info(struct super_block *sb)
3115 {
3116 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3117 	struct ext4_group_desc *gdp = NULL;
3118 	struct flex_groups *fg;
3119 	ext4_group_t flex_group;
3120 	int i, err;
3121 
3122 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3123 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3124 		sbi->s_log_groups_per_flex = 0;
3125 		return 1;
3126 	}
3127 
3128 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3129 	if (err)
3130 		goto failed;
3131 
3132 	for (i = 0; i < sbi->s_groups_count; i++) {
3133 		gdp = ext4_get_group_desc(sb, i, NULL);
3134 
3135 		flex_group = ext4_flex_group(sbi, i);
3136 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3137 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3138 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3139 			     &fg->free_clusters);
3140 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3141 	}
3142 
3143 	return 1;
3144 failed:
3145 	return 0;
3146 }
3147 
3148 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3149 				   struct ext4_group_desc *gdp)
3150 {
3151 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3152 	__u16 crc = 0;
3153 	__le32 le_group = cpu_to_le32(block_group);
3154 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3155 
3156 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3157 		/* Use new metadata_csum algorithm */
3158 		__u32 csum32;
3159 		__u16 dummy_csum = 0;
3160 
3161 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3162 				     sizeof(le_group));
3163 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3164 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3165 				     sizeof(dummy_csum));
3166 		offset += sizeof(dummy_csum);
3167 		if (offset < sbi->s_desc_size)
3168 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3169 					     sbi->s_desc_size - offset);
3170 
3171 		crc = csum32 & 0xFFFF;
3172 		goto out;
3173 	}
3174 
3175 	/* old crc16 code */
3176 	if (!ext4_has_feature_gdt_csum(sb))
3177 		return 0;
3178 
3179 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3180 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3181 	crc = crc16(crc, (__u8 *)gdp, offset);
3182 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3183 	/* for checksum of struct ext4_group_desc do the rest...*/
3184 	if (ext4_has_feature_64bit(sb) &&
3185 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3186 		crc = crc16(crc, (__u8 *)gdp + offset,
3187 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3188 				offset);
3189 
3190 out:
3191 	return cpu_to_le16(crc);
3192 }
3193 
3194 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3195 				struct ext4_group_desc *gdp)
3196 {
3197 	if (ext4_has_group_desc_csum(sb) &&
3198 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3199 		return 0;
3200 
3201 	return 1;
3202 }
3203 
3204 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3205 			      struct ext4_group_desc *gdp)
3206 {
3207 	if (!ext4_has_group_desc_csum(sb))
3208 		return;
3209 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3210 }
3211 
3212 /* Called at mount-time, super-block is locked */
3213 static int ext4_check_descriptors(struct super_block *sb,
3214 				  ext4_fsblk_t sb_block,
3215 				  ext4_group_t *first_not_zeroed)
3216 {
3217 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3218 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3219 	ext4_fsblk_t last_block;
3220 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3221 	ext4_fsblk_t block_bitmap;
3222 	ext4_fsblk_t inode_bitmap;
3223 	ext4_fsblk_t inode_table;
3224 	int flexbg_flag = 0;
3225 	ext4_group_t i, grp = sbi->s_groups_count;
3226 
3227 	if (ext4_has_feature_flex_bg(sb))
3228 		flexbg_flag = 1;
3229 
3230 	ext4_debug("Checking group descriptors");
3231 
3232 	for (i = 0; i < sbi->s_groups_count; i++) {
3233 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3234 
3235 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3236 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3237 		else
3238 			last_block = first_block +
3239 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3240 
3241 		if ((grp == sbi->s_groups_count) &&
3242 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3243 			grp = i;
3244 
3245 		block_bitmap = ext4_block_bitmap(sb, gdp);
3246 		if (block_bitmap == sb_block) {
3247 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3248 				 "Block bitmap for group %u overlaps "
3249 				 "superblock", i);
3250 			if (!sb_rdonly(sb))
3251 				return 0;
3252 		}
3253 		if (block_bitmap >= sb_block + 1 &&
3254 		    block_bitmap <= last_bg_block) {
3255 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3256 				 "Block bitmap for group %u overlaps "
3257 				 "block group descriptors", i);
3258 			if (!sb_rdonly(sb))
3259 				return 0;
3260 		}
3261 		if (block_bitmap < first_block || block_bitmap > last_block) {
3262 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3263 			       "Block bitmap for group %u not in group "
3264 			       "(block %llu)!", i, block_bitmap);
3265 			return 0;
3266 		}
3267 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3268 		if (inode_bitmap == sb_block) {
3269 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3270 				 "Inode bitmap for group %u overlaps "
3271 				 "superblock", i);
3272 			if (!sb_rdonly(sb))
3273 				return 0;
3274 		}
3275 		if (inode_bitmap >= sb_block + 1 &&
3276 		    inode_bitmap <= last_bg_block) {
3277 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3278 				 "Inode bitmap for group %u overlaps "
3279 				 "block group descriptors", i);
3280 			if (!sb_rdonly(sb))
3281 				return 0;
3282 		}
3283 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3284 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3285 			       "Inode bitmap for group %u not in group "
3286 			       "(block %llu)!", i, inode_bitmap);
3287 			return 0;
3288 		}
3289 		inode_table = ext4_inode_table(sb, gdp);
3290 		if (inode_table == sb_block) {
3291 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3292 				 "Inode table for group %u overlaps "
3293 				 "superblock", i);
3294 			if (!sb_rdonly(sb))
3295 				return 0;
3296 		}
3297 		if (inode_table >= sb_block + 1 &&
3298 		    inode_table <= last_bg_block) {
3299 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3300 				 "Inode table for group %u overlaps "
3301 				 "block group descriptors", i);
3302 			if (!sb_rdonly(sb))
3303 				return 0;
3304 		}
3305 		if (inode_table < first_block ||
3306 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3307 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3308 			       "Inode table for group %u not in group "
3309 			       "(block %llu)!", i, inode_table);
3310 			return 0;
3311 		}
3312 		ext4_lock_group(sb, i);
3313 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3314 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3315 				 "Checksum for group %u failed (%u!=%u)",
3316 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3317 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3318 			if (!sb_rdonly(sb)) {
3319 				ext4_unlock_group(sb, i);
3320 				return 0;
3321 			}
3322 		}
3323 		ext4_unlock_group(sb, i);
3324 		if (!flexbg_flag)
3325 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3326 	}
3327 	if (NULL != first_not_zeroed)
3328 		*first_not_zeroed = grp;
3329 	return 1;
3330 }
3331 
3332 /*
3333  * Maximal extent format file size.
3334  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3335  * extent format containers, within a sector_t, and within i_blocks
3336  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3337  * so that won't be a limiting factor.
3338  *
3339  * However there is other limiting factor. We do store extents in the form
3340  * of starting block and length, hence the resulting length of the extent
3341  * covering maximum file size must fit into on-disk format containers as
3342  * well. Given that length is always by 1 unit bigger than max unit (because
3343  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3344  *
3345  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3346  */
3347 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3348 {
3349 	loff_t res;
3350 	loff_t upper_limit = MAX_LFS_FILESIZE;
3351 
3352 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3353 
3354 	if (!has_huge_files) {
3355 		upper_limit = (1LL << 32) - 1;
3356 
3357 		/* total blocks in file system block size */
3358 		upper_limit >>= (blkbits - 9);
3359 		upper_limit <<= blkbits;
3360 	}
3361 
3362 	/*
3363 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3364 	 * by one fs block, so ee_len can cover the extent of maximum file
3365 	 * size
3366 	 */
3367 	res = (1LL << 32) - 1;
3368 	res <<= blkbits;
3369 
3370 	/* Sanity check against vm- & vfs- imposed limits */
3371 	if (res > upper_limit)
3372 		res = upper_limit;
3373 
3374 	return res;
3375 }
3376 
3377 /*
3378  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3379  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3380  * We need to be 1 filesystem block less than the 2^48 sector limit.
3381  */
3382 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3383 {
3384 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3385 	int meta_blocks;
3386 	unsigned int ppb = 1 << (bits - 2);
3387 
3388 	/*
3389 	 * This is calculated to be the largest file size for a dense, block
3390 	 * mapped file such that the file's total number of 512-byte sectors,
3391 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3392 	 *
3393 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3394 	 * number of 512-byte sectors of the file.
3395 	 */
3396 	if (!has_huge_files) {
3397 		/*
3398 		 * !has_huge_files or implies that the inode i_block field
3399 		 * represents total file blocks in 2^32 512-byte sectors ==
3400 		 * size of vfs inode i_blocks * 8
3401 		 */
3402 		upper_limit = (1LL << 32) - 1;
3403 
3404 		/* total blocks in file system block size */
3405 		upper_limit >>= (bits - 9);
3406 
3407 	} else {
3408 		/*
3409 		 * We use 48 bit ext4_inode i_blocks
3410 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3411 		 * represent total number of blocks in
3412 		 * file system block size
3413 		 */
3414 		upper_limit = (1LL << 48) - 1;
3415 
3416 	}
3417 
3418 	/* Compute how many blocks we can address by block tree */
3419 	res += ppb;
3420 	res += ppb * ppb;
3421 	res += ((loff_t)ppb) * ppb * ppb;
3422 	/* Compute how many metadata blocks are needed */
3423 	meta_blocks = 1;
3424 	meta_blocks += 1 + ppb;
3425 	meta_blocks += 1 + ppb + ppb * ppb;
3426 	/* Does block tree limit file size? */
3427 	if (res + meta_blocks <= upper_limit)
3428 		goto check_lfs;
3429 
3430 	res = upper_limit;
3431 	/* How many metadata blocks are needed for addressing upper_limit? */
3432 	upper_limit -= EXT4_NDIR_BLOCKS;
3433 	/* indirect blocks */
3434 	meta_blocks = 1;
3435 	upper_limit -= ppb;
3436 	/* double indirect blocks */
3437 	if (upper_limit < ppb * ppb) {
3438 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3439 		res -= meta_blocks;
3440 		goto check_lfs;
3441 	}
3442 	meta_blocks += 1 + ppb;
3443 	upper_limit -= ppb * ppb;
3444 	/* tripple indirect blocks for the rest */
3445 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3446 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3447 	res -= meta_blocks;
3448 check_lfs:
3449 	res <<= bits;
3450 	if (res > MAX_LFS_FILESIZE)
3451 		res = MAX_LFS_FILESIZE;
3452 
3453 	return res;
3454 }
3455 
3456 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3457 				   ext4_fsblk_t logical_sb_block, int nr)
3458 {
3459 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3460 	ext4_group_t bg, first_meta_bg;
3461 	int has_super = 0;
3462 
3463 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3464 
3465 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3466 		return logical_sb_block + nr + 1;
3467 	bg = sbi->s_desc_per_block * nr;
3468 	if (ext4_bg_has_super(sb, bg))
3469 		has_super = 1;
3470 
3471 	/*
3472 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3473 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3474 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3475 	 * compensate.
3476 	 */
3477 	if (sb->s_blocksize == 1024 && nr == 0 &&
3478 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3479 		has_super++;
3480 
3481 	return (has_super + ext4_group_first_block_no(sb, bg));
3482 }
3483 
3484 /**
3485  * ext4_get_stripe_size: Get the stripe size.
3486  * @sbi: In memory super block info
3487  *
3488  * If we have specified it via mount option, then
3489  * use the mount option value. If the value specified at mount time is
3490  * greater than the blocks per group use the super block value.
3491  * If the super block value is greater than blocks per group return 0.
3492  * Allocator needs it be less than blocks per group.
3493  *
3494  */
3495 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3496 {
3497 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3498 	unsigned long stripe_width =
3499 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3500 	int ret;
3501 
3502 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3503 		ret = sbi->s_stripe;
3504 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3505 		ret = stripe_width;
3506 	else if (stride && stride <= sbi->s_blocks_per_group)
3507 		ret = stride;
3508 	else
3509 		ret = 0;
3510 
3511 	/*
3512 	 * If the stripe width is 1, this makes no sense and
3513 	 * we set it to 0 to turn off stripe handling code.
3514 	 */
3515 	if (ret <= 1)
3516 		ret = 0;
3517 
3518 	return ret;
3519 }
3520 
3521 /*
3522  * Check whether this filesystem can be mounted based on
3523  * the features present and the RDONLY/RDWR mount requested.
3524  * Returns 1 if this filesystem can be mounted as requested,
3525  * 0 if it cannot be.
3526  */
3527 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3528 {
3529 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3530 		ext4_msg(sb, KERN_ERR,
3531 			"Couldn't mount because of "
3532 			"unsupported optional features (%x)",
3533 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3534 			~EXT4_FEATURE_INCOMPAT_SUPP));
3535 		return 0;
3536 	}
3537 
3538 #if !IS_ENABLED(CONFIG_UNICODE)
3539 	if (ext4_has_feature_casefold(sb)) {
3540 		ext4_msg(sb, KERN_ERR,
3541 			 "Filesystem with casefold feature cannot be "
3542 			 "mounted without CONFIG_UNICODE");
3543 		return 0;
3544 	}
3545 #endif
3546 
3547 	if (readonly)
3548 		return 1;
3549 
3550 	if (ext4_has_feature_readonly(sb)) {
3551 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3552 		sb->s_flags |= SB_RDONLY;
3553 		return 1;
3554 	}
3555 
3556 	/* Check that feature set is OK for a read-write mount */
3557 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3558 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3559 			 "unsupported optional features (%x)",
3560 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3561 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3562 		return 0;
3563 	}
3564 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3565 		ext4_msg(sb, KERN_ERR,
3566 			 "Can't support bigalloc feature without "
3567 			 "extents feature\n");
3568 		return 0;
3569 	}
3570 
3571 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3572 	if (!readonly && (ext4_has_feature_quota(sb) ||
3573 			  ext4_has_feature_project(sb))) {
3574 		ext4_msg(sb, KERN_ERR,
3575 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3576 		return 0;
3577 	}
3578 #endif  /* CONFIG_QUOTA */
3579 	return 1;
3580 }
3581 
3582 /*
3583  * This function is called once a day if we have errors logged
3584  * on the file system
3585  */
3586 static void print_daily_error_info(struct timer_list *t)
3587 {
3588 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3589 	struct super_block *sb = sbi->s_sb;
3590 	struct ext4_super_block *es = sbi->s_es;
3591 
3592 	if (es->s_error_count)
3593 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3594 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3595 			 le32_to_cpu(es->s_error_count));
3596 	if (es->s_first_error_time) {
3597 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3598 		       sb->s_id,
3599 		       ext4_get_tstamp(es, s_first_error_time),
3600 		       (int) sizeof(es->s_first_error_func),
3601 		       es->s_first_error_func,
3602 		       le32_to_cpu(es->s_first_error_line));
3603 		if (es->s_first_error_ino)
3604 			printk(KERN_CONT ": inode %u",
3605 			       le32_to_cpu(es->s_first_error_ino));
3606 		if (es->s_first_error_block)
3607 			printk(KERN_CONT ": block %llu", (unsigned long long)
3608 			       le64_to_cpu(es->s_first_error_block));
3609 		printk(KERN_CONT "\n");
3610 	}
3611 	if (es->s_last_error_time) {
3612 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3613 		       sb->s_id,
3614 		       ext4_get_tstamp(es, s_last_error_time),
3615 		       (int) sizeof(es->s_last_error_func),
3616 		       es->s_last_error_func,
3617 		       le32_to_cpu(es->s_last_error_line));
3618 		if (es->s_last_error_ino)
3619 			printk(KERN_CONT ": inode %u",
3620 			       le32_to_cpu(es->s_last_error_ino));
3621 		if (es->s_last_error_block)
3622 			printk(KERN_CONT ": block %llu", (unsigned long long)
3623 			       le64_to_cpu(es->s_last_error_block));
3624 		printk(KERN_CONT "\n");
3625 	}
3626 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3627 }
3628 
3629 /* Find next suitable group and run ext4_init_inode_table */
3630 static int ext4_run_li_request(struct ext4_li_request *elr)
3631 {
3632 	struct ext4_group_desc *gdp = NULL;
3633 	struct super_block *sb = elr->lr_super;
3634 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3635 	ext4_group_t group = elr->lr_next_group;
3636 	unsigned int prefetch_ios = 0;
3637 	int ret = 0;
3638 	u64 start_time;
3639 
3640 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3641 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3642 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3643 		if (prefetch_ios)
3644 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3645 					      prefetch_ios);
3646 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3647 					    prefetch_ios);
3648 		if (group >= elr->lr_next_group) {
3649 			ret = 1;
3650 			if (elr->lr_first_not_zeroed != ngroups &&
3651 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3652 				elr->lr_next_group = elr->lr_first_not_zeroed;
3653 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3654 				ret = 0;
3655 			}
3656 		}
3657 		return ret;
3658 	}
3659 
3660 	for (; group < ngroups; group++) {
3661 		gdp = ext4_get_group_desc(sb, group, NULL);
3662 		if (!gdp) {
3663 			ret = 1;
3664 			break;
3665 		}
3666 
3667 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3668 			break;
3669 	}
3670 
3671 	if (group >= ngroups)
3672 		ret = 1;
3673 
3674 	if (!ret) {
3675 		start_time = ktime_get_real_ns();
3676 		ret = ext4_init_inode_table(sb, group,
3677 					    elr->lr_timeout ? 0 : 1);
3678 		trace_ext4_lazy_itable_init(sb, group);
3679 		if (elr->lr_timeout == 0) {
3680 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3681 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3682 		}
3683 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3684 		elr->lr_next_group = group + 1;
3685 	}
3686 	return ret;
3687 }
3688 
3689 /*
3690  * Remove lr_request from the list_request and free the
3691  * request structure. Should be called with li_list_mtx held
3692  */
3693 static void ext4_remove_li_request(struct ext4_li_request *elr)
3694 {
3695 	if (!elr)
3696 		return;
3697 
3698 	list_del(&elr->lr_request);
3699 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3700 	kfree(elr);
3701 }
3702 
3703 static void ext4_unregister_li_request(struct super_block *sb)
3704 {
3705 	mutex_lock(&ext4_li_mtx);
3706 	if (!ext4_li_info) {
3707 		mutex_unlock(&ext4_li_mtx);
3708 		return;
3709 	}
3710 
3711 	mutex_lock(&ext4_li_info->li_list_mtx);
3712 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3713 	mutex_unlock(&ext4_li_info->li_list_mtx);
3714 	mutex_unlock(&ext4_li_mtx);
3715 }
3716 
3717 static struct task_struct *ext4_lazyinit_task;
3718 
3719 /*
3720  * This is the function where ext4lazyinit thread lives. It walks
3721  * through the request list searching for next scheduled filesystem.
3722  * When such a fs is found, run the lazy initialization request
3723  * (ext4_rn_li_request) and keep track of the time spend in this
3724  * function. Based on that time we compute next schedule time of
3725  * the request. When walking through the list is complete, compute
3726  * next waking time and put itself into sleep.
3727  */
3728 static int ext4_lazyinit_thread(void *arg)
3729 {
3730 	struct ext4_lazy_init *eli = arg;
3731 	struct list_head *pos, *n;
3732 	struct ext4_li_request *elr;
3733 	unsigned long next_wakeup, cur;
3734 
3735 	BUG_ON(NULL == eli);
3736 	set_freezable();
3737 
3738 cont_thread:
3739 	while (true) {
3740 		next_wakeup = MAX_JIFFY_OFFSET;
3741 
3742 		mutex_lock(&eli->li_list_mtx);
3743 		if (list_empty(&eli->li_request_list)) {
3744 			mutex_unlock(&eli->li_list_mtx);
3745 			goto exit_thread;
3746 		}
3747 		list_for_each_safe(pos, n, &eli->li_request_list) {
3748 			int err = 0;
3749 			int progress = 0;
3750 			elr = list_entry(pos, struct ext4_li_request,
3751 					 lr_request);
3752 
3753 			if (time_before(jiffies, elr->lr_next_sched)) {
3754 				if (time_before(elr->lr_next_sched, next_wakeup))
3755 					next_wakeup = elr->lr_next_sched;
3756 				continue;
3757 			}
3758 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3759 				if (sb_start_write_trylock(elr->lr_super)) {
3760 					progress = 1;
3761 					/*
3762 					 * We hold sb->s_umount, sb can not
3763 					 * be removed from the list, it is
3764 					 * now safe to drop li_list_mtx
3765 					 */
3766 					mutex_unlock(&eli->li_list_mtx);
3767 					err = ext4_run_li_request(elr);
3768 					sb_end_write(elr->lr_super);
3769 					mutex_lock(&eli->li_list_mtx);
3770 					n = pos->next;
3771 				}
3772 				up_read((&elr->lr_super->s_umount));
3773 			}
3774 			/* error, remove the lazy_init job */
3775 			if (err) {
3776 				ext4_remove_li_request(elr);
3777 				continue;
3778 			}
3779 			if (!progress) {
3780 				elr->lr_next_sched = jiffies +
3781 					prandom_u32_max(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3782 			}
3783 			if (time_before(elr->lr_next_sched, next_wakeup))
3784 				next_wakeup = elr->lr_next_sched;
3785 		}
3786 		mutex_unlock(&eli->li_list_mtx);
3787 
3788 		try_to_freeze();
3789 
3790 		cur = jiffies;
3791 		if ((time_after_eq(cur, next_wakeup)) ||
3792 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3793 			cond_resched();
3794 			continue;
3795 		}
3796 
3797 		schedule_timeout_interruptible(next_wakeup - cur);
3798 
3799 		if (kthread_should_stop()) {
3800 			ext4_clear_request_list();
3801 			goto exit_thread;
3802 		}
3803 	}
3804 
3805 exit_thread:
3806 	/*
3807 	 * It looks like the request list is empty, but we need
3808 	 * to check it under the li_list_mtx lock, to prevent any
3809 	 * additions into it, and of course we should lock ext4_li_mtx
3810 	 * to atomically free the list and ext4_li_info, because at
3811 	 * this point another ext4 filesystem could be registering
3812 	 * new one.
3813 	 */
3814 	mutex_lock(&ext4_li_mtx);
3815 	mutex_lock(&eli->li_list_mtx);
3816 	if (!list_empty(&eli->li_request_list)) {
3817 		mutex_unlock(&eli->li_list_mtx);
3818 		mutex_unlock(&ext4_li_mtx);
3819 		goto cont_thread;
3820 	}
3821 	mutex_unlock(&eli->li_list_mtx);
3822 	kfree(ext4_li_info);
3823 	ext4_li_info = NULL;
3824 	mutex_unlock(&ext4_li_mtx);
3825 
3826 	return 0;
3827 }
3828 
3829 static void ext4_clear_request_list(void)
3830 {
3831 	struct list_head *pos, *n;
3832 	struct ext4_li_request *elr;
3833 
3834 	mutex_lock(&ext4_li_info->li_list_mtx);
3835 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3836 		elr = list_entry(pos, struct ext4_li_request,
3837 				 lr_request);
3838 		ext4_remove_li_request(elr);
3839 	}
3840 	mutex_unlock(&ext4_li_info->li_list_mtx);
3841 }
3842 
3843 static int ext4_run_lazyinit_thread(void)
3844 {
3845 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3846 					 ext4_li_info, "ext4lazyinit");
3847 	if (IS_ERR(ext4_lazyinit_task)) {
3848 		int err = PTR_ERR(ext4_lazyinit_task);
3849 		ext4_clear_request_list();
3850 		kfree(ext4_li_info);
3851 		ext4_li_info = NULL;
3852 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3853 				 "initialization thread\n",
3854 				 err);
3855 		return err;
3856 	}
3857 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3858 	return 0;
3859 }
3860 
3861 /*
3862  * Check whether it make sense to run itable init. thread or not.
3863  * If there is at least one uninitialized inode table, return
3864  * corresponding group number, else the loop goes through all
3865  * groups and return total number of groups.
3866  */
3867 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3868 {
3869 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3870 	struct ext4_group_desc *gdp = NULL;
3871 
3872 	if (!ext4_has_group_desc_csum(sb))
3873 		return ngroups;
3874 
3875 	for (group = 0; group < ngroups; group++) {
3876 		gdp = ext4_get_group_desc(sb, group, NULL);
3877 		if (!gdp)
3878 			continue;
3879 
3880 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3881 			break;
3882 	}
3883 
3884 	return group;
3885 }
3886 
3887 static int ext4_li_info_new(void)
3888 {
3889 	struct ext4_lazy_init *eli = NULL;
3890 
3891 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3892 	if (!eli)
3893 		return -ENOMEM;
3894 
3895 	INIT_LIST_HEAD(&eli->li_request_list);
3896 	mutex_init(&eli->li_list_mtx);
3897 
3898 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3899 
3900 	ext4_li_info = eli;
3901 
3902 	return 0;
3903 }
3904 
3905 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3906 					    ext4_group_t start)
3907 {
3908 	struct ext4_li_request *elr;
3909 
3910 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3911 	if (!elr)
3912 		return NULL;
3913 
3914 	elr->lr_super = sb;
3915 	elr->lr_first_not_zeroed = start;
3916 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3917 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3918 		elr->lr_next_group = start;
3919 	} else {
3920 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3921 	}
3922 
3923 	/*
3924 	 * Randomize first schedule time of the request to
3925 	 * spread the inode table initialization requests
3926 	 * better.
3927 	 */
3928 	elr->lr_next_sched = jiffies + prandom_u32_max(
3929 				EXT4_DEF_LI_MAX_START_DELAY * HZ);
3930 	return elr;
3931 }
3932 
3933 int ext4_register_li_request(struct super_block *sb,
3934 			     ext4_group_t first_not_zeroed)
3935 {
3936 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3937 	struct ext4_li_request *elr = NULL;
3938 	ext4_group_t ngroups = sbi->s_groups_count;
3939 	int ret = 0;
3940 
3941 	mutex_lock(&ext4_li_mtx);
3942 	if (sbi->s_li_request != NULL) {
3943 		/*
3944 		 * Reset timeout so it can be computed again, because
3945 		 * s_li_wait_mult might have changed.
3946 		 */
3947 		sbi->s_li_request->lr_timeout = 0;
3948 		goto out;
3949 	}
3950 
3951 	if (sb_rdonly(sb) ||
3952 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3953 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
3954 		goto out;
3955 
3956 	elr = ext4_li_request_new(sb, first_not_zeroed);
3957 	if (!elr) {
3958 		ret = -ENOMEM;
3959 		goto out;
3960 	}
3961 
3962 	if (NULL == ext4_li_info) {
3963 		ret = ext4_li_info_new();
3964 		if (ret)
3965 			goto out;
3966 	}
3967 
3968 	mutex_lock(&ext4_li_info->li_list_mtx);
3969 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3970 	mutex_unlock(&ext4_li_info->li_list_mtx);
3971 
3972 	sbi->s_li_request = elr;
3973 	/*
3974 	 * set elr to NULL here since it has been inserted to
3975 	 * the request_list and the removal and free of it is
3976 	 * handled by ext4_clear_request_list from now on.
3977 	 */
3978 	elr = NULL;
3979 
3980 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3981 		ret = ext4_run_lazyinit_thread();
3982 		if (ret)
3983 			goto out;
3984 	}
3985 out:
3986 	mutex_unlock(&ext4_li_mtx);
3987 	if (ret)
3988 		kfree(elr);
3989 	return ret;
3990 }
3991 
3992 /*
3993  * We do not need to lock anything since this is called on
3994  * module unload.
3995  */
3996 static void ext4_destroy_lazyinit_thread(void)
3997 {
3998 	/*
3999 	 * If thread exited earlier
4000 	 * there's nothing to be done.
4001 	 */
4002 	if (!ext4_li_info || !ext4_lazyinit_task)
4003 		return;
4004 
4005 	kthread_stop(ext4_lazyinit_task);
4006 }
4007 
4008 static int set_journal_csum_feature_set(struct super_block *sb)
4009 {
4010 	int ret = 1;
4011 	int compat, incompat;
4012 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4013 
4014 	if (ext4_has_metadata_csum(sb)) {
4015 		/* journal checksum v3 */
4016 		compat = 0;
4017 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4018 	} else {
4019 		/* journal checksum v1 */
4020 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4021 		incompat = 0;
4022 	}
4023 
4024 	jbd2_journal_clear_features(sbi->s_journal,
4025 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4026 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4027 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4028 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4029 		ret = jbd2_journal_set_features(sbi->s_journal,
4030 				compat, 0,
4031 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4032 				incompat);
4033 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4034 		ret = jbd2_journal_set_features(sbi->s_journal,
4035 				compat, 0,
4036 				incompat);
4037 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4038 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4039 	} else {
4040 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4041 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4042 	}
4043 
4044 	return ret;
4045 }
4046 
4047 /*
4048  * Note: calculating the overhead so we can be compatible with
4049  * historical BSD practice is quite difficult in the face of
4050  * clusters/bigalloc.  This is because multiple metadata blocks from
4051  * different block group can end up in the same allocation cluster.
4052  * Calculating the exact overhead in the face of clustered allocation
4053  * requires either O(all block bitmaps) in memory or O(number of block
4054  * groups**2) in time.  We will still calculate the superblock for
4055  * older file systems --- and if we come across with a bigalloc file
4056  * system with zero in s_overhead_clusters the estimate will be close to
4057  * correct especially for very large cluster sizes --- but for newer
4058  * file systems, it's better to calculate this figure once at mkfs
4059  * time, and store it in the superblock.  If the superblock value is
4060  * present (even for non-bigalloc file systems), we will use it.
4061  */
4062 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4063 			  char *buf)
4064 {
4065 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4066 	struct ext4_group_desc	*gdp;
4067 	ext4_fsblk_t		first_block, last_block, b;
4068 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4069 	int			s, j, count = 0;
4070 	int			has_super = ext4_bg_has_super(sb, grp);
4071 
4072 	if (!ext4_has_feature_bigalloc(sb))
4073 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4074 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4075 			sbi->s_itb_per_group + 2);
4076 
4077 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4078 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4079 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4080 	for (i = 0; i < ngroups; i++) {
4081 		gdp = ext4_get_group_desc(sb, i, NULL);
4082 		b = ext4_block_bitmap(sb, gdp);
4083 		if (b >= first_block && b <= last_block) {
4084 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4085 			count++;
4086 		}
4087 		b = ext4_inode_bitmap(sb, gdp);
4088 		if (b >= first_block && b <= last_block) {
4089 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4090 			count++;
4091 		}
4092 		b = ext4_inode_table(sb, gdp);
4093 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4094 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4095 				int c = EXT4_B2C(sbi, b - first_block);
4096 				ext4_set_bit(c, buf);
4097 				count++;
4098 			}
4099 		if (i != grp)
4100 			continue;
4101 		s = 0;
4102 		if (ext4_bg_has_super(sb, grp)) {
4103 			ext4_set_bit(s++, buf);
4104 			count++;
4105 		}
4106 		j = ext4_bg_num_gdb(sb, grp);
4107 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4108 			ext4_error(sb, "Invalid number of block group "
4109 				   "descriptor blocks: %d", j);
4110 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4111 		}
4112 		count += j;
4113 		for (; j > 0; j--)
4114 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4115 	}
4116 	if (!count)
4117 		return 0;
4118 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4119 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4120 }
4121 
4122 /*
4123  * Compute the overhead and stash it in sbi->s_overhead
4124  */
4125 int ext4_calculate_overhead(struct super_block *sb)
4126 {
4127 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4128 	struct ext4_super_block *es = sbi->s_es;
4129 	struct inode *j_inode;
4130 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4131 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4132 	ext4_fsblk_t overhead = 0;
4133 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4134 
4135 	if (!buf)
4136 		return -ENOMEM;
4137 
4138 	/*
4139 	 * Compute the overhead (FS structures).  This is constant
4140 	 * for a given filesystem unless the number of block groups
4141 	 * changes so we cache the previous value until it does.
4142 	 */
4143 
4144 	/*
4145 	 * All of the blocks before first_data_block are overhead
4146 	 */
4147 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4148 
4149 	/*
4150 	 * Add the overhead found in each block group
4151 	 */
4152 	for (i = 0; i < ngroups; i++) {
4153 		int blks;
4154 
4155 		blks = count_overhead(sb, i, buf);
4156 		overhead += blks;
4157 		if (blks)
4158 			memset(buf, 0, PAGE_SIZE);
4159 		cond_resched();
4160 	}
4161 
4162 	/*
4163 	 * Add the internal journal blocks whether the journal has been
4164 	 * loaded or not
4165 	 */
4166 	if (sbi->s_journal && !sbi->s_journal_bdev)
4167 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4168 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4169 		/* j_inum for internal journal is non-zero */
4170 		j_inode = ext4_get_journal_inode(sb, j_inum);
4171 		if (j_inode) {
4172 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4173 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4174 			iput(j_inode);
4175 		} else {
4176 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4177 		}
4178 	}
4179 	sbi->s_overhead = overhead;
4180 	smp_wmb();
4181 	free_page((unsigned long) buf);
4182 	return 0;
4183 }
4184 
4185 static void ext4_set_resv_clusters(struct super_block *sb)
4186 {
4187 	ext4_fsblk_t resv_clusters;
4188 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4189 
4190 	/*
4191 	 * There's no need to reserve anything when we aren't using extents.
4192 	 * The space estimates are exact, there are no unwritten extents,
4193 	 * hole punching doesn't need new metadata... This is needed especially
4194 	 * to keep ext2/3 backward compatibility.
4195 	 */
4196 	if (!ext4_has_feature_extents(sb))
4197 		return;
4198 	/*
4199 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4200 	 * This should cover the situations where we can not afford to run
4201 	 * out of space like for example punch hole, or converting
4202 	 * unwritten extents in delalloc path. In most cases such
4203 	 * allocation would require 1, or 2 blocks, higher numbers are
4204 	 * very rare.
4205 	 */
4206 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4207 			 sbi->s_cluster_bits);
4208 
4209 	do_div(resv_clusters, 50);
4210 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4211 
4212 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4213 }
4214 
4215 static const char *ext4_quota_mode(struct super_block *sb)
4216 {
4217 #ifdef CONFIG_QUOTA
4218 	if (!ext4_quota_capable(sb))
4219 		return "none";
4220 
4221 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4222 		return "journalled";
4223 	else
4224 		return "writeback";
4225 #else
4226 	return "disabled";
4227 #endif
4228 }
4229 
4230 static void ext4_setup_csum_trigger(struct super_block *sb,
4231 				    enum ext4_journal_trigger_type type,
4232 				    void (*trigger)(
4233 					struct jbd2_buffer_trigger_type *type,
4234 					struct buffer_head *bh,
4235 					void *mapped_data,
4236 					size_t size))
4237 {
4238 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4239 
4240 	sbi->s_journal_triggers[type].sb = sb;
4241 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4242 }
4243 
4244 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4245 {
4246 	if (!sbi)
4247 		return;
4248 
4249 	kfree(sbi->s_blockgroup_lock);
4250 	fs_put_dax(sbi->s_daxdev, NULL);
4251 	kfree(sbi);
4252 }
4253 
4254 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4255 {
4256 	struct ext4_sb_info *sbi;
4257 
4258 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4259 	if (!sbi)
4260 		return NULL;
4261 
4262 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4263 					   NULL, NULL);
4264 
4265 	sbi->s_blockgroup_lock =
4266 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4267 
4268 	if (!sbi->s_blockgroup_lock)
4269 		goto err_out;
4270 
4271 	sb->s_fs_info = sbi;
4272 	sbi->s_sb = sb;
4273 	return sbi;
4274 err_out:
4275 	fs_put_dax(sbi->s_daxdev, NULL);
4276 	kfree(sbi);
4277 	return NULL;
4278 }
4279 
4280 static void ext4_set_def_opts(struct super_block *sb,
4281 			      struct ext4_super_block *es)
4282 {
4283 	unsigned long def_mount_opts;
4284 
4285 	/* Set defaults before we parse the mount options */
4286 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4287 	set_opt(sb, INIT_INODE_TABLE);
4288 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4289 		set_opt(sb, DEBUG);
4290 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4291 		set_opt(sb, GRPID);
4292 	if (def_mount_opts & EXT4_DEFM_UID16)
4293 		set_opt(sb, NO_UID32);
4294 	/* xattr user namespace & acls are now defaulted on */
4295 	set_opt(sb, XATTR_USER);
4296 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4297 	set_opt(sb, POSIX_ACL);
4298 #endif
4299 	if (ext4_has_feature_fast_commit(sb))
4300 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4301 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4302 	if (ext4_has_metadata_csum(sb))
4303 		set_opt(sb, JOURNAL_CHECKSUM);
4304 
4305 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4306 		set_opt(sb, JOURNAL_DATA);
4307 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4308 		set_opt(sb, ORDERED_DATA);
4309 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4310 		set_opt(sb, WRITEBACK_DATA);
4311 
4312 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4313 		set_opt(sb, ERRORS_PANIC);
4314 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4315 		set_opt(sb, ERRORS_CONT);
4316 	else
4317 		set_opt(sb, ERRORS_RO);
4318 	/* block_validity enabled by default; disable with noblock_validity */
4319 	set_opt(sb, BLOCK_VALIDITY);
4320 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4321 		set_opt(sb, DISCARD);
4322 
4323 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4324 		set_opt(sb, BARRIER);
4325 
4326 	/*
4327 	 * enable delayed allocation by default
4328 	 * Use -o nodelalloc to turn it off
4329 	 */
4330 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4331 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4332 		set_opt(sb, DELALLOC);
4333 
4334 	if (sb->s_blocksize == PAGE_SIZE)
4335 		set_opt(sb, DIOREAD_NOLOCK);
4336 }
4337 
4338 static int ext4_handle_clustersize(struct super_block *sb)
4339 {
4340 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4341 	struct ext4_super_block *es = sbi->s_es;
4342 	int clustersize;
4343 
4344 	/* Handle clustersize */
4345 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4346 	if (ext4_has_feature_bigalloc(sb)) {
4347 		if (clustersize < sb->s_blocksize) {
4348 			ext4_msg(sb, KERN_ERR,
4349 				 "cluster size (%d) smaller than "
4350 				 "block size (%lu)", clustersize, sb->s_blocksize);
4351 			return -EINVAL;
4352 		}
4353 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4354 			le32_to_cpu(es->s_log_block_size);
4355 		sbi->s_clusters_per_group =
4356 			le32_to_cpu(es->s_clusters_per_group);
4357 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4358 			ext4_msg(sb, KERN_ERR,
4359 				 "#clusters per group too big: %lu",
4360 				 sbi->s_clusters_per_group);
4361 			return -EINVAL;
4362 		}
4363 		if (sbi->s_blocks_per_group !=
4364 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4365 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4366 				 "clusters per group (%lu) inconsistent",
4367 				 sbi->s_blocks_per_group,
4368 				 sbi->s_clusters_per_group);
4369 			return -EINVAL;
4370 		}
4371 	} else {
4372 		if (clustersize != sb->s_blocksize) {
4373 			ext4_msg(sb, KERN_ERR,
4374 				 "fragment/cluster size (%d) != "
4375 				 "block size (%lu)", clustersize, sb->s_blocksize);
4376 			return -EINVAL;
4377 		}
4378 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4379 			ext4_msg(sb, KERN_ERR,
4380 				 "#blocks per group too big: %lu",
4381 				 sbi->s_blocks_per_group);
4382 			return -EINVAL;
4383 		}
4384 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4385 		sbi->s_cluster_bits = 0;
4386 	}
4387 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4388 
4389 	/* Do we have standard group size of clustersize * 8 blocks ? */
4390 	if (sbi->s_blocks_per_group == clustersize << 3)
4391 		set_opt2(sb, STD_GROUP_SIZE);
4392 
4393 	return 0;
4394 }
4395 
4396 static void ext4_fast_commit_init(struct super_block *sb)
4397 {
4398 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4399 
4400 	/* Initialize fast commit stuff */
4401 	atomic_set(&sbi->s_fc_subtid, 0);
4402 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4403 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4404 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4405 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4406 	sbi->s_fc_bytes = 0;
4407 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4408 	sbi->s_fc_ineligible_tid = 0;
4409 	spin_lock_init(&sbi->s_fc_lock);
4410 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4411 	sbi->s_fc_replay_state.fc_regions = NULL;
4412 	sbi->s_fc_replay_state.fc_regions_size = 0;
4413 	sbi->s_fc_replay_state.fc_regions_used = 0;
4414 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4415 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4416 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4417 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4418 }
4419 
4420 static int ext4_inode_info_init(struct super_block *sb,
4421 				struct ext4_super_block *es)
4422 {
4423 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4424 
4425 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4426 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4427 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4428 	} else {
4429 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4430 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4431 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4432 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4433 				 sbi->s_first_ino);
4434 			return -EINVAL;
4435 		}
4436 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4437 		    (!is_power_of_2(sbi->s_inode_size)) ||
4438 		    (sbi->s_inode_size > sb->s_blocksize)) {
4439 			ext4_msg(sb, KERN_ERR,
4440 			       "unsupported inode size: %d",
4441 			       sbi->s_inode_size);
4442 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4443 			return -EINVAL;
4444 		}
4445 		/*
4446 		 * i_atime_extra is the last extra field available for
4447 		 * [acm]times in struct ext4_inode. Checking for that
4448 		 * field should suffice to ensure we have extra space
4449 		 * for all three.
4450 		 */
4451 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4452 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4453 			sb->s_time_gran = 1;
4454 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4455 		} else {
4456 			sb->s_time_gran = NSEC_PER_SEC;
4457 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4458 		}
4459 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4460 	}
4461 
4462 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4463 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4464 			EXT4_GOOD_OLD_INODE_SIZE;
4465 		if (ext4_has_feature_extra_isize(sb)) {
4466 			unsigned v, max = (sbi->s_inode_size -
4467 					   EXT4_GOOD_OLD_INODE_SIZE);
4468 
4469 			v = le16_to_cpu(es->s_want_extra_isize);
4470 			if (v > max) {
4471 				ext4_msg(sb, KERN_ERR,
4472 					 "bad s_want_extra_isize: %d", v);
4473 				return -EINVAL;
4474 			}
4475 			if (sbi->s_want_extra_isize < v)
4476 				sbi->s_want_extra_isize = v;
4477 
4478 			v = le16_to_cpu(es->s_min_extra_isize);
4479 			if (v > max) {
4480 				ext4_msg(sb, KERN_ERR,
4481 					 "bad s_min_extra_isize: %d", v);
4482 				return -EINVAL;
4483 			}
4484 			if (sbi->s_want_extra_isize < v)
4485 				sbi->s_want_extra_isize = v;
4486 		}
4487 	}
4488 
4489 	return 0;
4490 }
4491 
4492 #if IS_ENABLED(CONFIG_UNICODE)
4493 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4494 {
4495 	const struct ext4_sb_encodings *encoding_info;
4496 	struct unicode_map *encoding;
4497 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4498 
4499 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4500 		return 0;
4501 
4502 	encoding_info = ext4_sb_read_encoding(es);
4503 	if (!encoding_info) {
4504 		ext4_msg(sb, KERN_ERR,
4505 			"Encoding requested by superblock is unknown");
4506 		return -EINVAL;
4507 	}
4508 
4509 	encoding = utf8_load(encoding_info->version);
4510 	if (IS_ERR(encoding)) {
4511 		ext4_msg(sb, KERN_ERR,
4512 			"can't mount with superblock charset: %s-%u.%u.%u "
4513 			"not supported by the kernel. flags: 0x%x.",
4514 			encoding_info->name,
4515 			unicode_major(encoding_info->version),
4516 			unicode_minor(encoding_info->version),
4517 			unicode_rev(encoding_info->version),
4518 			encoding_flags);
4519 		return -EINVAL;
4520 	}
4521 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4522 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4523 		unicode_major(encoding_info->version),
4524 		unicode_minor(encoding_info->version),
4525 		unicode_rev(encoding_info->version),
4526 		encoding_flags);
4527 
4528 	sb->s_encoding = encoding;
4529 	sb->s_encoding_flags = encoding_flags;
4530 
4531 	return 0;
4532 }
4533 #else
4534 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4535 {
4536 	return 0;
4537 }
4538 #endif
4539 
4540 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4541 {
4542 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4543 
4544 	/* Warn if metadata_csum and gdt_csum are both set. */
4545 	if (ext4_has_feature_metadata_csum(sb) &&
4546 	    ext4_has_feature_gdt_csum(sb))
4547 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4548 			     "redundant flags; please run fsck.");
4549 
4550 	/* Check for a known checksum algorithm */
4551 	if (!ext4_verify_csum_type(sb, es)) {
4552 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4553 			 "unknown checksum algorithm.");
4554 		return -EINVAL;
4555 	}
4556 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4557 				ext4_orphan_file_block_trigger);
4558 
4559 	/* Load the checksum driver */
4560 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4561 	if (IS_ERR(sbi->s_chksum_driver)) {
4562 		int ret = PTR_ERR(sbi->s_chksum_driver);
4563 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4564 		sbi->s_chksum_driver = NULL;
4565 		return ret;
4566 	}
4567 
4568 	/* Check superblock checksum */
4569 	if (!ext4_superblock_csum_verify(sb, es)) {
4570 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4571 			 "invalid superblock checksum.  Run e2fsck?");
4572 		return -EFSBADCRC;
4573 	}
4574 
4575 	/* Precompute checksum seed for all metadata */
4576 	if (ext4_has_feature_csum_seed(sb))
4577 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4578 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4579 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4580 					       sizeof(es->s_uuid));
4581 	return 0;
4582 }
4583 
4584 static int ext4_check_feature_compatibility(struct super_block *sb,
4585 					    struct ext4_super_block *es,
4586 					    int silent)
4587 {
4588 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4589 	    (ext4_has_compat_features(sb) ||
4590 	     ext4_has_ro_compat_features(sb) ||
4591 	     ext4_has_incompat_features(sb)))
4592 		ext4_msg(sb, KERN_WARNING,
4593 		       "feature flags set on rev 0 fs, "
4594 		       "running e2fsck is recommended");
4595 
4596 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4597 		set_opt2(sb, HURD_COMPAT);
4598 		if (ext4_has_feature_64bit(sb)) {
4599 			ext4_msg(sb, KERN_ERR,
4600 				 "The Hurd can't support 64-bit file systems");
4601 			return -EINVAL;
4602 		}
4603 
4604 		/*
4605 		 * ea_inode feature uses l_i_version field which is not
4606 		 * available in HURD_COMPAT mode.
4607 		 */
4608 		if (ext4_has_feature_ea_inode(sb)) {
4609 			ext4_msg(sb, KERN_ERR,
4610 				 "ea_inode feature is not supported for Hurd");
4611 			return -EINVAL;
4612 		}
4613 	}
4614 
4615 	if (IS_EXT2_SB(sb)) {
4616 		if (ext2_feature_set_ok(sb))
4617 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4618 				 "using the ext4 subsystem");
4619 		else {
4620 			/*
4621 			 * If we're probing be silent, if this looks like
4622 			 * it's actually an ext[34] filesystem.
4623 			 */
4624 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4625 				return -EINVAL;
4626 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4627 				 "to feature incompatibilities");
4628 			return -EINVAL;
4629 		}
4630 	}
4631 
4632 	if (IS_EXT3_SB(sb)) {
4633 		if (ext3_feature_set_ok(sb))
4634 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4635 				 "using the ext4 subsystem");
4636 		else {
4637 			/*
4638 			 * If we're probing be silent, if this looks like
4639 			 * it's actually an ext4 filesystem.
4640 			 */
4641 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4642 				return -EINVAL;
4643 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4644 				 "to feature incompatibilities");
4645 			return -EINVAL;
4646 		}
4647 	}
4648 
4649 	/*
4650 	 * Check feature flags regardless of the revision level, since we
4651 	 * previously didn't change the revision level when setting the flags,
4652 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4653 	 */
4654 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4655 		return -EINVAL;
4656 
4657 	return 0;
4658 }
4659 
4660 static int ext4_geometry_check(struct super_block *sb,
4661 			       struct ext4_super_block *es)
4662 {
4663 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4664 	__u64 blocks_count;
4665 
4666 	/* check blocks count against device size */
4667 	blocks_count = sb_bdev_nr_blocks(sb);
4668 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4669 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4670 		       "exceeds size of device (%llu blocks)",
4671 		       ext4_blocks_count(es), blocks_count);
4672 		return -EINVAL;
4673 	}
4674 
4675 	/*
4676 	 * It makes no sense for the first data block to be beyond the end
4677 	 * of the filesystem.
4678 	 */
4679 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4680 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4681 			 "block %u is beyond end of filesystem (%llu)",
4682 			 le32_to_cpu(es->s_first_data_block),
4683 			 ext4_blocks_count(es));
4684 		return -EINVAL;
4685 	}
4686 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4687 	    (sbi->s_cluster_ratio == 1)) {
4688 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4689 			 "block is 0 with a 1k block and cluster size");
4690 		return -EINVAL;
4691 	}
4692 
4693 	blocks_count = (ext4_blocks_count(es) -
4694 			le32_to_cpu(es->s_first_data_block) +
4695 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4696 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4697 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4698 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4699 		       "(block count %llu, first data block %u, "
4700 		       "blocks per group %lu)", blocks_count,
4701 		       ext4_blocks_count(es),
4702 		       le32_to_cpu(es->s_first_data_block),
4703 		       EXT4_BLOCKS_PER_GROUP(sb));
4704 		return -EINVAL;
4705 	}
4706 	sbi->s_groups_count = blocks_count;
4707 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4708 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4709 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4710 	    le32_to_cpu(es->s_inodes_count)) {
4711 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4712 			 le32_to_cpu(es->s_inodes_count),
4713 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4714 		return -EINVAL;
4715 	}
4716 
4717 	return 0;
4718 }
4719 
4720 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
4721 {
4722 	struct buffer_head **group_desc;
4723 	int i;
4724 
4725 	rcu_read_lock();
4726 	group_desc = rcu_dereference(sbi->s_group_desc);
4727 	for (i = 0; i < sbi->s_gdb_count; i++)
4728 		brelse(group_desc[i]);
4729 	kvfree(group_desc);
4730 	rcu_read_unlock();
4731 }
4732 
4733 static int ext4_group_desc_init(struct super_block *sb,
4734 				struct ext4_super_block *es,
4735 				ext4_fsblk_t logical_sb_block,
4736 				ext4_group_t *first_not_zeroed)
4737 {
4738 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4739 	unsigned int db_count;
4740 	ext4_fsblk_t block;
4741 	int ret;
4742 	int i;
4743 
4744 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4745 		   EXT4_DESC_PER_BLOCK(sb);
4746 	if (ext4_has_feature_meta_bg(sb)) {
4747 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4748 			ext4_msg(sb, KERN_WARNING,
4749 				 "first meta block group too large: %u "
4750 				 "(group descriptor block count %u)",
4751 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4752 			return -EINVAL;
4753 		}
4754 	}
4755 	rcu_assign_pointer(sbi->s_group_desc,
4756 			   kvmalloc_array(db_count,
4757 					  sizeof(struct buffer_head *),
4758 					  GFP_KERNEL));
4759 	if (sbi->s_group_desc == NULL) {
4760 		ext4_msg(sb, KERN_ERR, "not enough memory");
4761 		return -ENOMEM;
4762 	}
4763 
4764 	bgl_lock_init(sbi->s_blockgroup_lock);
4765 
4766 	/* Pre-read the descriptors into the buffer cache */
4767 	for (i = 0; i < db_count; i++) {
4768 		block = descriptor_loc(sb, logical_sb_block, i);
4769 		ext4_sb_breadahead_unmovable(sb, block);
4770 	}
4771 
4772 	for (i = 0; i < db_count; i++) {
4773 		struct buffer_head *bh;
4774 
4775 		block = descriptor_loc(sb, logical_sb_block, i);
4776 		bh = ext4_sb_bread_unmovable(sb, block);
4777 		if (IS_ERR(bh)) {
4778 			ext4_msg(sb, KERN_ERR,
4779 			       "can't read group descriptor %d", i);
4780 			sbi->s_gdb_count = i;
4781 			ret = PTR_ERR(bh);
4782 			goto out;
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 		ret = -EFSCORRUPTED;
4792 		goto out;
4793 	}
4794 	return 0;
4795 out:
4796 	ext4_group_desc_free(sbi);
4797 	return ret;
4798 }
4799 
4800 static int ext4_load_and_init_journal(struct super_block *sb,
4801 				      struct ext4_super_block *es,
4802 				      struct ext4_fs_context *ctx)
4803 {
4804 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4805 	int err;
4806 
4807 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4808 	if (err)
4809 		return err;
4810 
4811 	if (ext4_has_feature_64bit(sb) &&
4812 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4813 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4814 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4815 		goto out;
4816 	}
4817 
4818 	if (!set_journal_csum_feature_set(sb)) {
4819 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4820 			 "feature set");
4821 		goto out;
4822 	}
4823 
4824 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4825 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4826 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4827 		ext4_msg(sb, KERN_ERR,
4828 			"Failed to set fast commit journal feature");
4829 		goto out;
4830 	}
4831 
4832 	/* We have now updated the journal if required, so we can
4833 	 * validate the data journaling mode. */
4834 	switch (test_opt(sb, DATA_FLAGS)) {
4835 	case 0:
4836 		/* No mode set, assume a default based on the journal
4837 		 * capabilities: ORDERED_DATA if the journal can
4838 		 * cope, else JOURNAL_DATA
4839 		 */
4840 		if (jbd2_journal_check_available_features
4841 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4842 			set_opt(sb, ORDERED_DATA);
4843 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4844 		} else {
4845 			set_opt(sb, JOURNAL_DATA);
4846 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4847 		}
4848 		break;
4849 
4850 	case EXT4_MOUNT_ORDERED_DATA:
4851 	case EXT4_MOUNT_WRITEBACK_DATA:
4852 		if (!jbd2_journal_check_available_features
4853 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4854 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4855 			       "requested data journaling mode");
4856 			goto out;
4857 		}
4858 		break;
4859 	default:
4860 		break;
4861 	}
4862 
4863 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4864 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4865 		ext4_msg(sb, KERN_ERR, "can't mount with "
4866 			"journal_async_commit in data=ordered mode");
4867 		goto out;
4868 	}
4869 
4870 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4871 
4872 	sbi->s_journal->j_submit_inode_data_buffers =
4873 		ext4_journal_submit_inode_data_buffers;
4874 	sbi->s_journal->j_finish_inode_data_buffers =
4875 		ext4_journal_finish_inode_data_buffers;
4876 
4877 	return 0;
4878 
4879 out:
4880 	/* flush s_error_work before journal destroy. */
4881 	flush_work(&sbi->s_error_work);
4882 	jbd2_journal_destroy(sbi->s_journal);
4883 	sbi->s_journal = NULL;
4884 	return err;
4885 }
4886 
4887 static int ext4_journal_data_mode_check(struct super_block *sb)
4888 {
4889 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4890 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4891 			    "data=journal disables delayed allocation, "
4892 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4893 		/* can't mount with both data=journal and dioread_nolock. */
4894 		clear_opt(sb, DIOREAD_NOLOCK);
4895 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4896 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4897 			ext4_msg(sb, KERN_ERR, "can't mount with "
4898 				 "both data=journal and delalloc");
4899 			return -EINVAL;
4900 		}
4901 		if (test_opt(sb, DAX_ALWAYS)) {
4902 			ext4_msg(sb, KERN_ERR, "can't mount with "
4903 				 "both data=journal and dax");
4904 			return -EINVAL;
4905 		}
4906 		if (ext4_has_feature_encrypt(sb)) {
4907 			ext4_msg(sb, KERN_WARNING,
4908 				 "encrypted files will use data=ordered "
4909 				 "instead of data journaling mode");
4910 		}
4911 		if (test_opt(sb, DELALLOC))
4912 			clear_opt(sb, DELALLOC);
4913 	} else {
4914 		sb->s_iflags |= SB_I_CGROUPWB;
4915 	}
4916 
4917 	return 0;
4918 }
4919 
4920 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
4921 			   int silent)
4922 {
4923 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4924 	struct ext4_super_block *es;
4925 	ext4_fsblk_t logical_sb_block;
4926 	unsigned long offset = 0;
4927 	struct buffer_head *bh;
4928 	int ret = -EINVAL;
4929 	int blocksize;
4930 
4931 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4932 	if (!blocksize) {
4933 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4934 		return -EINVAL;
4935 	}
4936 
4937 	/*
4938 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4939 	 * block sizes.  We need to calculate the offset from buffer start.
4940 	 */
4941 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4942 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4943 		offset = do_div(logical_sb_block, blocksize);
4944 	} else {
4945 		logical_sb_block = sbi->s_sb_block;
4946 	}
4947 
4948 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4949 	if (IS_ERR(bh)) {
4950 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4951 		return PTR_ERR(bh);
4952 	}
4953 	/*
4954 	 * Note: s_es must be initialized as soon as possible because
4955 	 *       some ext4 macro-instructions depend on its value
4956 	 */
4957 	es = (struct ext4_super_block *) (bh->b_data + offset);
4958 	sbi->s_es = es;
4959 	sb->s_magic = le16_to_cpu(es->s_magic);
4960 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
4961 		if (!silent)
4962 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4963 		goto out;
4964 	}
4965 
4966 	if (le32_to_cpu(es->s_log_block_size) >
4967 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4968 		ext4_msg(sb, KERN_ERR,
4969 			 "Invalid log block size: %u",
4970 			 le32_to_cpu(es->s_log_block_size));
4971 		goto out;
4972 	}
4973 	if (le32_to_cpu(es->s_log_cluster_size) >
4974 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4975 		ext4_msg(sb, KERN_ERR,
4976 			 "Invalid log cluster size: %u",
4977 			 le32_to_cpu(es->s_log_cluster_size));
4978 		goto out;
4979 	}
4980 
4981 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4982 
4983 	/*
4984 	 * If the default block size is not the same as the real block size,
4985 	 * we need to reload it.
4986 	 */
4987 	if (sb->s_blocksize == blocksize) {
4988 		*lsb = logical_sb_block;
4989 		sbi->s_sbh = bh;
4990 		return 0;
4991 	}
4992 
4993 	/*
4994 	 * bh must be released before kill_bdev(), otherwise
4995 	 * it won't be freed and its page also. kill_bdev()
4996 	 * is called by sb_set_blocksize().
4997 	 */
4998 	brelse(bh);
4999 	/* Validate the filesystem blocksize */
5000 	if (!sb_set_blocksize(sb, blocksize)) {
5001 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5002 				blocksize);
5003 		bh = NULL;
5004 		goto out;
5005 	}
5006 
5007 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5008 	offset = do_div(logical_sb_block, blocksize);
5009 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5010 	if (IS_ERR(bh)) {
5011 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5012 		ret = PTR_ERR(bh);
5013 		bh = NULL;
5014 		goto out;
5015 	}
5016 	es = (struct ext4_super_block *)(bh->b_data + offset);
5017 	sbi->s_es = es;
5018 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5019 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5020 		goto out;
5021 	}
5022 	*lsb = logical_sb_block;
5023 	sbi->s_sbh = bh;
5024 	return 0;
5025 out:
5026 	brelse(bh);
5027 	return ret;
5028 }
5029 
5030 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5031 {
5032 	struct ext4_super_block *es = NULL;
5033 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5034 	struct flex_groups **flex_groups;
5035 	ext4_fsblk_t block;
5036 	ext4_fsblk_t logical_sb_block;
5037 	struct inode *root;
5038 	int ret = -ENOMEM;
5039 	unsigned int i;
5040 	int needs_recovery, has_huge_files;
5041 	int err = 0;
5042 	ext4_group_t first_not_zeroed;
5043 	struct ext4_fs_context *ctx = fc->fs_private;
5044 	int silent = fc->sb_flags & SB_SILENT;
5045 
5046 	/* Set defaults for the variables that will be set during parsing */
5047 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5048 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5049 
5050 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5051 	sbi->s_sectors_written_start =
5052 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5053 
5054 	/* -EINVAL is default */
5055 	ret = -EINVAL;
5056 	err = ext4_load_super(sb, &logical_sb_block, silent);
5057 	if (err)
5058 		goto out_fail;
5059 
5060 	es = sbi->s_es;
5061 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5062 
5063 	err = ext4_init_metadata_csum(sb, es);
5064 	if (err)
5065 		goto failed_mount;
5066 
5067 	ext4_set_def_opts(sb, es);
5068 
5069 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5070 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5071 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5072 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5073 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5074 
5075 	/*
5076 	 * set default s_li_wait_mult for lazyinit, for the case there is
5077 	 * no mount option specified.
5078 	 */
5079 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5080 
5081 	if (ext4_inode_info_init(sb, es))
5082 		goto failed_mount;
5083 
5084 	err = parse_apply_sb_mount_options(sb, ctx);
5085 	if (err < 0)
5086 		goto failed_mount;
5087 
5088 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5089 
5090 	err = ext4_check_opt_consistency(fc, sb);
5091 	if (err < 0)
5092 		goto failed_mount;
5093 
5094 	ext4_apply_options(fc, sb);
5095 
5096 	if (ext4_encoding_init(sb, es))
5097 		goto failed_mount;
5098 
5099 	if (ext4_journal_data_mode_check(sb))
5100 		goto failed_mount;
5101 
5102 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5103 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5104 
5105 	/* i_version is always enabled now */
5106 	sb->s_flags |= SB_I_VERSION;
5107 
5108 	if (ext4_check_feature_compatibility(sb, es, silent))
5109 		goto failed_mount;
5110 
5111 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
5112 		ext4_msg(sb, KERN_ERR,
5113 			 "Number of reserved GDT blocks insanely large: %d",
5114 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
5115 		goto failed_mount;
5116 	}
5117 
5118 	if (sbi->s_daxdev) {
5119 		if (sb->s_blocksize == PAGE_SIZE)
5120 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
5121 		else
5122 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
5123 	}
5124 
5125 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
5126 		if (ext4_has_feature_inline_data(sb)) {
5127 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
5128 					" that may contain inline data");
5129 			goto failed_mount;
5130 		}
5131 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
5132 			ext4_msg(sb, KERN_ERR,
5133 				"DAX unsupported by block device.");
5134 			goto failed_mount;
5135 		}
5136 	}
5137 
5138 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
5139 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
5140 			 es->s_encryption_level);
5141 		goto failed_mount;
5142 	}
5143 
5144 	has_huge_files = ext4_has_feature_huge_file(sb);
5145 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5146 						      has_huge_files);
5147 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5148 
5149 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5150 	if (ext4_has_feature_64bit(sb)) {
5151 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5152 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5153 		    !is_power_of_2(sbi->s_desc_size)) {
5154 			ext4_msg(sb, KERN_ERR,
5155 			       "unsupported descriptor size %lu",
5156 			       sbi->s_desc_size);
5157 			goto failed_mount;
5158 		}
5159 	} else
5160 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5161 
5162 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5163 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5164 
5165 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5166 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5167 		if (!silent)
5168 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5169 		goto failed_mount;
5170 	}
5171 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5172 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5173 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5174 			 sbi->s_inodes_per_group);
5175 		goto failed_mount;
5176 	}
5177 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5178 					sbi->s_inodes_per_block;
5179 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5180 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5181 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5182 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5183 
5184 	for (i = 0; i < 4; i++)
5185 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5186 	sbi->s_def_hash_version = es->s_def_hash_version;
5187 	if (ext4_has_feature_dir_index(sb)) {
5188 		i = le32_to_cpu(es->s_flags);
5189 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5190 			sbi->s_hash_unsigned = 3;
5191 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5192 #ifdef __CHAR_UNSIGNED__
5193 			if (!sb_rdonly(sb))
5194 				es->s_flags |=
5195 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5196 			sbi->s_hash_unsigned = 3;
5197 #else
5198 			if (!sb_rdonly(sb))
5199 				es->s_flags |=
5200 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5201 #endif
5202 		}
5203 	}
5204 
5205 	if (ext4_handle_clustersize(sb))
5206 		goto failed_mount;
5207 
5208 	/*
5209 	 * Test whether we have more sectors than will fit in sector_t,
5210 	 * and whether the max offset is addressable by the page cache.
5211 	 */
5212 	err = generic_check_addressable(sb->s_blocksize_bits,
5213 					ext4_blocks_count(es));
5214 	if (err) {
5215 		ext4_msg(sb, KERN_ERR, "filesystem"
5216 			 " too large to mount safely on this system");
5217 		goto failed_mount;
5218 	}
5219 
5220 	if (ext4_geometry_check(sb, es))
5221 		goto failed_mount;
5222 
5223 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5224 	if (err)
5225 		goto failed_mount;
5226 
5227 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5228 	spin_lock_init(&sbi->s_error_lock);
5229 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5230 
5231 	/* Register extent status tree shrinker */
5232 	if (ext4_es_register_shrinker(sbi))
5233 		goto failed_mount3;
5234 
5235 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5236 	sbi->s_extent_max_zeroout_kb = 32;
5237 
5238 	/*
5239 	 * set up enough so that it can read an inode
5240 	 */
5241 	sb->s_op = &ext4_sops;
5242 	sb->s_export_op = &ext4_export_ops;
5243 	sb->s_xattr = ext4_xattr_handlers;
5244 #ifdef CONFIG_FS_ENCRYPTION
5245 	sb->s_cop = &ext4_cryptops;
5246 #endif
5247 #ifdef CONFIG_FS_VERITY
5248 	sb->s_vop = &ext4_verityops;
5249 #endif
5250 #ifdef CONFIG_QUOTA
5251 	sb->dq_op = &ext4_quota_operations;
5252 	if (ext4_has_feature_quota(sb))
5253 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5254 	else
5255 		sb->s_qcop = &ext4_qctl_operations;
5256 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5257 #endif
5258 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5259 
5260 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5261 	mutex_init(&sbi->s_orphan_lock);
5262 
5263 	ext4_fast_commit_init(sb);
5264 
5265 	sb->s_root = NULL;
5266 
5267 	needs_recovery = (es->s_last_orphan != 0 ||
5268 			  ext4_has_feature_orphan_present(sb) ||
5269 			  ext4_has_feature_journal_needs_recovery(sb));
5270 
5271 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5272 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5273 			goto failed_mount3a;
5274 
5275 	/*
5276 	 * The first inode we look at is the journal inode.  Don't try
5277 	 * root first: it may be modified in the journal!
5278 	 */
5279 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5280 		err = ext4_load_and_init_journal(sb, es, ctx);
5281 		if (err)
5282 			goto failed_mount3a;
5283 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5284 		   ext4_has_feature_journal_needs_recovery(sb)) {
5285 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5286 		       "suppressed and not mounted read-only");
5287 		goto failed_mount3a;
5288 	} else {
5289 		/* Nojournal mode, all journal mount options are illegal */
5290 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5291 			ext4_msg(sb, KERN_ERR, "can't mount with "
5292 				 "journal_checksum, fs mounted w/o journal");
5293 			goto failed_mount3a;
5294 		}
5295 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5296 			ext4_msg(sb, KERN_ERR, "can't mount with "
5297 				 "journal_async_commit, fs mounted w/o journal");
5298 			goto failed_mount3a;
5299 		}
5300 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5301 			ext4_msg(sb, KERN_ERR, "can't mount with "
5302 				 "commit=%lu, fs mounted w/o journal",
5303 				 sbi->s_commit_interval / HZ);
5304 			goto failed_mount3a;
5305 		}
5306 		if (EXT4_MOUNT_DATA_FLAGS &
5307 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5308 			ext4_msg(sb, KERN_ERR, "can't mount with "
5309 				 "data=, fs mounted w/o journal");
5310 			goto failed_mount3a;
5311 		}
5312 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5313 		clear_opt(sb, JOURNAL_CHECKSUM);
5314 		clear_opt(sb, DATA_FLAGS);
5315 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5316 		sbi->s_journal = NULL;
5317 		needs_recovery = 0;
5318 	}
5319 
5320 	if (!test_opt(sb, NO_MBCACHE)) {
5321 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5322 		if (!sbi->s_ea_block_cache) {
5323 			ext4_msg(sb, KERN_ERR,
5324 				 "Failed to create ea_block_cache");
5325 			goto failed_mount_wq;
5326 		}
5327 
5328 		if (ext4_has_feature_ea_inode(sb)) {
5329 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5330 			if (!sbi->s_ea_inode_cache) {
5331 				ext4_msg(sb, KERN_ERR,
5332 					 "Failed to create ea_inode_cache");
5333 				goto failed_mount_wq;
5334 			}
5335 		}
5336 	}
5337 
5338 	if (ext4_has_feature_verity(sb) && sb->s_blocksize != PAGE_SIZE) {
5339 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5340 		goto failed_mount_wq;
5341 	}
5342 
5343 	/*
5344 	 * Get the # of file system overhead blocks from the
5345 	 * superblock if present.
5346 	 */
5347 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5348 	/* ignore the precalculated value if it is ridiculous */
5349 	if (sbi->s_overhead > ext4_blocks_count(es))
5350 		sbi->s_overhead = 0;
5351 	/*
5352 	 * If the bigalloc feature is not enabled recalculating the
5353 	 * overhead doesn't take long, so we might as well just redo
5354 	 * it to make sure we are using the correct value.
5355 	 */
5356 	if (!ext4_has_feature_bigalloc(sb))
5357 		sbi->s_overhead = 0;
5358 	if (sbi->s_overhead == 0) {
5359 		err = ext4_calculate_overhead(sb);
5360 		if (err)
5361 			goto failed_mount_wq;
5362 	}
5363 
5364 	/*
5365 	 * The maximum number of concurrent works can be high and
5366 	 * concurrency isn't really necessary.  Limit it to 1.
5367 	 */
5368 	EXT4_SB(sb)->rsv_conversion_wq =
5369 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5370 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5371 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5372 		ret = -ENOMEM;
5373 		goto failed_mount4;
5374 	}
5375 
5376 	/*
5377 	 * The jbd2_journal_load will have done any necessary log recovery,
5378 	 * so we can safely mount the rest of the filesystem now.
5379 	 */
5380 
5381 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5382 	if (IS_ERR(root)) {
5383 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5384 		ret = PTR_ERR(root);
5385 		root = NULL;
5386 		goto failed_mount4;
5387 	}
5388 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5389 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5390 		iput(root);
5391 		goto failed_mount4;
5392 	}
5393 
5394 	sb->s_root = d_make_root(root);
5395 	if (!sb->s_root) {
5396 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5397 		ret = -ENOMEM;
5398 		goto failed_mount4;
5399 	}
5400 
5401 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5402 	if (ret == -EROFS) {
5403 		sb->s_flags |= SB_RDONLY;
5404 		ret = 0;
5405 	} else if (ret)
5406 		goto failed_mount4a;
5407 
5408 	ext4_set_resv_clusters(sb);
5409 
5410 	if (test_opt(sb, BLOCK_VALIDITY)) {
5411 		err = ext4_setup_system_zone(sb);
5412 		if (err) {
5413 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5414 				 "zone (%d)", err);
5415 			goto failed_mount4a;
5416 		}
5417 	}
5418 	ext4_fc_replay_cleanup(sb);
5419 
5420 	ext4_ext_init(sb);
5421 
5422 	/*
5423 	 * Enable optimize_scan if number of groups is > threshold. This can be
5424 	 * turned off by passing "mb_optimize_scan=0". This can also be
5425 	 * turned on forcefully by passing "mb_optimize_scan=1".
5426 	 */
5427 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5428 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5429 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5430 		else
5431 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5432 	}
5433 
5434 	err = ext4_mb_init(sb);
5435 	if (err) {
5436 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5437 			 err);
5438 		goto failed_mount5;
5439 	}
5440 
5441 	/*
5442 	 * We can only set up the journal commit callback once
5443 	 * mballoc is initialized
5444 	 */
5445 	if (sbi->s_journal)
5446 		sbi->s_journal->j_commit_callback =
5447 			ext4_journal_commit_callback;
5448 
5449 	block = ext4_count_free_clusters(sb);
5450 	ext4_free_blocks_count_set(sbi->s_es,
5451 				   EXT4_C2B(sbi, block));
5452 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5453 				  GFP_KERNEL);
5454 	if (!err) {
5455 		unsigned long freei = ext4_count_free_inodes(sb);
5456 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5457 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5458 					  GFP_KERNEL);
5459 	}
5460 	if (!err)
5461 		err = percpu_counter_init(&sbi->s_dirs_counter,
5462 					  ext4_count_dirs(sb), GFP_KERNEL);
5463 	if (!err)
5464 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5465 					  GFP_KERNEL);
5466 	if (!err)
5467 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5468 					  GFP_KERNEL);
5469 	if (!err)
5470 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5471 
5472 	if (err) {
5473 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5474 		goto failed_mount6;
5475 	}
5476 
5477 	if (ext4_has_feature_flex_bg(sb))
5478 		if (!ext4_fill_flex_info(sb)) {
5479 			ext4_msg(sb, KERN_ERR,
5480 			       "unable to initialize "
5481 			       "flex_bg meta info!");
5482 			ret = -ENOMEM;
5483 			goto failed_mount6;
5484 		}
5485 
5486 	err = ext4_register_li_request(sb, first_not_zeroed);
5487 	if (err)
5488 		goto failed_mount6;
5489 
5490 	err = ext4_register_sysfs(sb);
5491 	if (err)
5492 		goto failed_mount7;
5493 
5494 	err = ext4_init_orphan_info(sb);
5495 	if (err)
5496 		goto failed_mount8;
5497 #ifdef CONFIG_QUOTA
5498 	/* Enable quota usage during mount. */
5499 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5500 		err = ext4_enable_quotas(sb);
5501 		if (err)
5502 			goto failed_mount9;
5503 	}
5504 #endif  /* CONFIG_QUOTA */
5505 
5506 	/*
5507 	 * Save the original bdev mapping's wb_err value which could be
5508 	 * used to detect the metadata async write error.
5509 	 */
5510 	spin_lock_init(&sbi->s_bdev_wb_lock);
5511 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5512 				 &sbi->s_bdev_wb_err);
5513 	sb->s_bdev->bd_super = sb;
5514 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5515 	ext4_orphan_cleanup(sb, es);
5516 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5517 	/*
5518 	 * Update the checksum after updating free space/inode counters and
5519 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5520 	 * checksum in the buffer cache until it is written out and
5521 	 * e2fsprogs programs trying to open a file system immediately
5522 	 * after it is mounted can fail.
5523 	 */
5524 	ext4_superblock_csum_set(sb);
5525 	if (needs_recovery) {
5526 		ext4_msg(sb, KERN_INFO, "recovery complete");
5527 		err = ext4_mark_recovery_complete(sb, es);
5528 		if (err)
5529 			goto failed_mount9;
5530 	}
5531 
5532 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5533 		ext4_msg(sb, KERN_WARNING,
5534 			 "mounting with \"discard\" option, but the device does not support discard");
5535 
5536 	if (es->s_error_count)
5537 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5538 
5539 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5540 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5541 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5542 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5543 	atomic_set(&sbi->s_warning_count, 0);
5544 	atomic_set(&sbi->s_msg_count, 0);
5545 
5546 	return 0;
5547 
5548 failed_mount9:
5549 	ext4_release_orphan_info(sb);
5550 failed_mount8:
5551 	ext4_unregister_sysfs(sb);
5552 	kobject_put(&sbi->s_kobj);
5553 failed_mount7:
5554 	ext4_unregister_li_request(sb);
5555 failed_mount6:
5556 	ext4_mb_release(sb);
5557 	rcu_read_lock();
5558 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5559 	if (flex_groups) {
5560 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5561 			kvfree(flex_groups[i]);
5562 		kvfree(flex_groups);
5563 	}
5564 	rcu_read_unlock();
5565 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5566 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5567 	percpu_counter_destroy(&sbi->s_dirs_counter);
5568 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5569 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5570 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5571 failed_mount5:
5572 	ext4_ext_release(sb);
5573 	ext4_release_system_zone(sb);
5574 failed_mount4a:
5575 	dput(sb->s_root);
5576 	sb->s_root = NULL;
5577 failed_mount4:
5578 	ext4_msg(sb, KERN_ERR, "mount failed");
5579 	if (EXT4_SB(sb)->rsv_conversion_wq)
5580 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5581 failed_mount_wq:
5582 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5583 	sbi->s_ea_inode_cache = NULL;
5584 
5585 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5586 	sbi->s_ea_block_cache = NULL;
5587 
5588 	if (sbi->s_journal) {
5589 		/* flush s_error_work before journal destroy. */
5590 		flush_work(&sbi->s_error_work);
5591 		jbd2_journal_destroy(sbi->s_journal);
5592 		sbi->s_journal = NULL;
5593 	}
5594 failed_mount3a:
5595 	ext4_es_unregister_shrinker(sbi);
5596 failed_mount3:
5597 	/* flush s_error_work before sbi destroy */
5598 	flush_work(&sbi->s_error_work);
5599 	del_timer_sync(&sbi->s_err_report);
5600 	ext4_stop_mmpd(sbi);
5601 	ext4_group_desc_free(sbi);
5602 failed_mount:
5603 	if (sbi->s_chksum_driver)
5604 		crypto_free_shash(sbi->s_chksum_driver);
5605 
5606 #if IS_ENABLED(CONFIG_UNICODE)
5607 	utf8_unload(sb->s_encoding);
5608 #endif
5609 
5610 #ifdef CONFIG_QUOTA
5611 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5612 		kfree(get_qf_name(sb, sbi, i));
5613 #endif
5614 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5615 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5616 	brelse(sbi->s_sbh);
5617 	ext4_blkdev_remove(sbi);
5618 out_fail:
5619 	sb->s_fs_info = NULL;
5620 	return err ? err : ret;
5621 }
5622 
5623 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5624 {
5625 	struct ext4_fs_context *ctx = fc->fs_private;
5626 	struct ext4_sb_info *sbi;
5627 	const char *descr;
5628 	int ret;
5629 
5630 	sbi = ext4_alloc_sbi(sb);
5631 	if (!sbi)
5632 		return -ENOMEM;
5633 
5634 	fc->s_fs_info = sbi;
5635 
5636 	/* Cleanup superblock name */
5637 	strreplace(sb->s_id, '/', '!');
5638 
5639 	sbi->s_sb_block = 1;	/* Default super block location */
5640 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5641 		sbi->s_sb_block = ctx->s_sb_block;
5642 
5643 	ret = __ext4_fill_super(fc, sb);
5644 	if (ret < 0)
5645 		goto free_sbi;
5646 
5647 	if (sbi->s_journal) {
5648 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5649 			descr = " journalled data mode";
5650 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5651 			descr = " ordered data mode";
5652 		else
5653 			descr = " writeback data mode";
5654 	} else
5655 		descr = "out journal";
5656 
5657 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5658 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5659 			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
5660 
5661 	/* Update the s_overhead_clusters if necessary */
5662 	ext4_update_overhead(sb, false);
5663 	return 0;
5664 
5665 free_sbi:
5666 	ext4_free_sbi(sbi);
5667 	fc->s_fs_info = NULL;
5668 	return ret;
5669 }
5670 
5671 static int ext4_get_tree(struct fs_context *fc)
5672 {
5673 	return get_tree_bdev(fc, ext4_fill_super);
5674 }
5675 
5676 /*
5677  * Setup any per-fs journal parameters now.  We'll do this both on
5678  * initial mount, once the journal has been initialised but before we've
5679  * done any recovery; and again on any subsequent remount.
5680  */
5681 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5682 {
5683 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5684 
5685 	journal->j_commit_interval = sbi->s_commit_interval;
5686 	journal->j_min_batch_time = sbi->s_min_batch_time;
5687 	journal->j_max_batch_time = sbi->s_max_batch_time;
5688 	ext4_fc_init(sb, journal);
5689 
5690 	write_lock(&journal->j_state_lock);
5691 	if (test_opt(sb, BARRIER))
5692 		journal->j_flags |= JBD2_BARRIER;
5693 	else
5694 		journal->j_flags &= ~JBD2_BARRIER;
5695 	if (test_opt(sb, DATA_ERR_ABORT))
5696 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5697 	else
5698 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5699 	write_unlock(&journal->j_state_lock);
5700 }
5701 
5702 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5703 					     unsigned int journal_inum)
5704 {
5705 	struct inode *journal_inode;
5706 
5707 	/*
5708 	 * Test for the existence of a valid inode on disk.  Bad things
5709 	 * happen if we iget() an unused inode, as the subsequent iput()
5710 	 * will try to delete it.
5711 	 */
5712 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5713 	if (IS_ERR(journal_inode)) {
5714 		ext4_msg(sb, KERN_ERR, "no journal found");
5715 		return NULL;
5716 	}
5717 	if (!journal_inode->i_nlink) {
5718 		make_bad_inode(journal_inode);
5719 		iput(journal_inode);
5720 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5721 		return NULL;
5722 	}
5723 
5724 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5725 		  journal_inode, journal_inode->i_size);
5726 	if (!S_ISREG(journal_inode->i_mode)) {
5727 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5728 		iput(journal_inode);
5729 		return NULL;
5730 	}
5731 	return journal_inode;
5732 }
5733 
5734 static journal_t *ext4_get_journal(struct super_block *sb,
5735 				   unsigned int journal_inum)
5736 {
5737 	struct inode *journal_inode;
5738 	journal_t *journal;
5739 
5740 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5741 		return NULL;
5742 
5743 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5744 	if (!journal_inode)
5745 		return NULL;
5746 
5747 	journal = jbd2_journal_init_inode(journal_inode);
5748 	if (!journal) {
5749 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5750 		iput(journal_inode);
5751 		return NULL;
5752 	}
5753 	journal->j_private = sb;
5754 	ext4_init_journal_params(sb, journal);
5755 	return journal;
5756 }
5757 
5758 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5759 				       dev_t j_dev)
5760 {
5761 	struct buffer_head *bh;
5762 	journal_t *journal;
5763 	ext4_fsblk_t start;
5764 	ext4_fsblk_t len;
5765 	int hblock, blocksize;
5766 	ext4_fsblk_t sb_block;
5767 	unsigned long offset;
5768 	struct ext4_super_block *es;
5769 	struct block_device *bdev;
5770 
5771 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5772 		return NULL;
5773 
5774 	bdev = ext4_blkdev_get(j_dev, sb);
5775 	if (bdev == NULL)
5776 		return NULL;
5777 
5778 	blocksize = sb->s_blocksize;
5779 	hblock = bdev_logical_block_size(bdev);
5780 	if (blocksize < hblock) {
5781 		ext4_msg(sb, KERN_ERR,
5782 			"blocksize too small for journal device");
5783 		goto out_bdev;
5784 	}
5785 
5786 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5787 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5788 	set_blocksize(bdev, blocksize);
5789 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5790 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5791 		       "external journal");
5792 		goto out_bdev;
5793 	}
5794 
5795 	es = (struct ext4_super_block *) (bh->b_data + offset);
5796 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5797 	    !(le32_to_cpu(es->s_feature_incompat) &
5798 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5799 		ext4_msg(sb, KERN_ERR, "external journal has "
5800 					"bad superblock");
5801 		brelse(bh);
5802 		goto out_bdev;
5803 	}
5804 
5805 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5806 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5807 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5808 		ext4_msg(sb, KERN_ERR, "external journal has "
5809 				       "corrupt superblock");
5810 		brelse(bh);
5811 		goto out_bdev;
5812 	}
5813 
5814 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5815 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5816 		brelse(bh);
5817 		goto out_bdev;
5818 	}
5819 
5820 	len = ext4_blocks_count(es);
5821 	start = sb_block + 1;
5822 	brelse(bh);	/* we're done with the superblock */
5823 
5824 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5825 					start, len, blocksize);
5826 	if (!journal) {
5827 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5828 		goto out_bdev;
5829 	}
5830 	journal->j_private = sb;
5831 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5832 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5833 		goto out_journal;
5834 	}
5835 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5836 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5837 					"user (unsupported) - %d",
5838 			be32_to_cpu(journal->j_superblock->s_nr_users));
5839 		goto out_journal;
5840 	}
5841 	EXT4_SB(sb)->s_journal_bdev = bdev;
5842 	ext4_init_journal_params(sb, journal);
5843 	return journal;
5844 
5845 out_journal:
5846 	jbd2_journal_destroy(journal);
5847 out_bdev:
5848 	ext4_blkdev_put(bdev);
5849 	return NULL;
5850 }
5851 
5852 static int ext4_load_journal(struct super_block *sb,
5853 			     struct ext4_super_block *es,
5854 			     unsigned long journal_devnum)
5855 {
5856 	journal_t *journal;
5857 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5858 	dev_t journal_dev;
5859 	int err = 0;
5860 	int really_read_only;
5861 	int journal_dev_ro;
5862 
5863 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5864 		return -EFSCORRUPTED;
5865 
5866 	if (journal_devnum &&
5867 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5868 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5869 			"numbers have changed");
5870 		journal_dev = new_decode_dev(journal_devnum);
5871 	} else
5872 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5873 
5874 	if (journal_inum && journal_dev) {
5875 		ext4_msg(sb, KERN_ERR,
5876 			 "filesystem has both journal inode and journal device!");
5877 		return -EINVAL;
5878 	}
5879 
5880 	if (journal_inum) {
5881 		journal = ext4_get_journal(sb, journal_inum);
5882 		if (!journal)
5883 			return -EINVAL;
5884 	} else {
5885 		journal = ext4_get_dev_journal(sb, journal_dev);
5886 		if (!journal)
5887 			return -EINVAL;
5888 	}
5889 
5890 	journal_dev_ro = bdev_read_only(journal->j_dev);
5891 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5892 
5893 	if (journal_dev_ro && !sb_rdonly(sb)) {
5894 		ext4_msg(sb, KERN_ERR,
5895 			 "journal device read-only, try mounting with '-o ro'");
5896 		err = -EROFS;
5897 		goto err_out;
5898 	}
5899 
5900 	/*
5901 	 * Are we loading a blank journal or performing recovery after a
5902 	 * crash?  For recovery, we need to check in advance whether we
5903 	 * can get read-write access to the device.
5904 	 */
5905 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5906 		if (sb_rdonly(sb)) {
5907 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5908 					"required on readonly filesystem");
5909 			if (really_read_only) {
5910 				ext4_msg(sb, KERN_ERR, "write access "
5911 					"unavailable, cannot proceed "
5912 					"(try mounting with noload)");
5913 				err = -EROFS;
5914 				goto err_out;
5915 			}
5916 			ext4_msg(sb, KERN_INFO, "write access will "
5917 			       "be enabled during recovery");
5918 		}
5919 	}
5920 
5921 	if (!(journal->j_flags & JBD2_BARRIER))
5922 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5923 
5924 	if (!ext4_has_feature_journal_needs_recovery(sb))
5925 		err = jbd2_journal_wipe(journal, !really_read_only);
5926 	if (!err) {
5927 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5928 		if (save)
5929 			memcpy(save, ((char *) es) +
5930 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5931 		err = jbd2_journal_load(journal);
5932 		if (save)
5933 			memcpy(((char *) es) + EXT4_S_ERR_START,
5934 			       save, EXT4_S_ERR_LEN);
5935 		kfree(save);
5936 	}
5937 
5938 	if (err) {
5939 		ext4_msg(sb, KERN_ERR, "error loading journal");
5940 		goto err_out;
5941 	}
5942 
5943 	EXT4_SB(sb)->s_journal = journal;
5944 	err = ext4_clear_journal_err(sb, es);
5945 	if (err) {
5946 		EXT4_SB(sb)->s_journal = NULL;
5947 		jbd2_journal_destroy(journal);
5948 		return err;
5949 	}
5950 
5951 	if (!really_read_only && journal_devnum &&
5952 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5953 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5954 
5955 		/* Make sure we flush the recovery flag to disk. */
5956 		ext4_commit_super(sb);
5957 	}
5958 
5959 	return 0;
5960 
5961 err_out:
5962 	jbd2_journal_destroy(journal);
5963 	return err;
5964 }
5965 
5966 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5967 static void ext4_update_super(struct super_block *sb)
5968 {
5969 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5970 	struct ext4_super_block *es = sbi->s_es;
5971 	struct buffer_head *sbh = sbi->s_sbh;
5972 
5973 	lock_buffer(sbh);
5974 	/*
5975 	 * If the file system is mounted read-only, don't update the
5976 	 * superblock write time.  This avoids updating the superblock
5977 	 * write time when we are mounting the root file system
5978 	 * read/only but we need to replay the journal; at that point,
5979 	 * for people who are east of GMT and who make their clock
5980 	 * tick in localtime for Windows bug-for-bug compatibility,
5981 	 * the clock is set in the future, and this will cause e2fsck
5982 	 * to complain and force a full file system check.
5983 	 */
5984 	if (!(sb->s_flags & SB_RDONLY))
5985 		ext4_update_tstamp(es, s_wtime);
5986 	es->s_kbytes_written =
5987 		cpu_to_le64(sbi->s_kbytes_written +
5988 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5989 		      sbi->s_sectors_written_start) >> 1));
5990 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5991 		ext4_free_blocks_count_set(es,
5992 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5993 				&sbi->s_freeclusters_counter)));
5994 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5995 		es->s_free_inodes_count =
5996 			cpu_to_le32(percpu_counter_sum_positive(
5997 				&sbi->s_freeinodes_counter));
5998 	/* Copy error information to the on-disk superblock */
5999 	spin_lock(&sbi->s_error_lock);
6000 	if (sbi->s_add_error_count > 0) {
6001 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6002 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6003 			__ext4_update_tstamp(&es->s_first_error_time,
6004 					     &es->s_first_error_time_hi,
6005 					     sbi->s_first_error_time);
6006 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6007 				sizeof(es->s_first_error_func));
6008 			es->s_first_error_line =
6009 				cpu_to_le32(sbi->s_first_error_line);
6010 			es->s_first_error_ino =
6011 				cpu_to_le32(sbi->s_first_error_ino);
6012 			es->s_first_error_block =
6013 				cpu_to_le64(sbi->s_first_error_block);
6014 			es->s_first_error_errcode =
6015 				ext4_errno_to_code(sbi->s_first_error_code);
6016 		}
6017 		__ext4_update_tstamp(&es->s_last_error_time,
6018 				     &es->s_last_error_time_hi,
6019 				     sbi->s_last_error_time);
6020 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6021 			sizeof(es->s_last_error_func));
6022 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6023 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6024 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6025 		es->s_last_error_errcode =
6026 				ext4_errno_to_code(sbi->s_last_error_code);
6027 		/*
6028 		 * Start the daily error reporting function if it hasn't been
6029 		 * started already
6030 		 */
6031 		if (!es->s_error_count)
6032 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6033 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6034 		sbi->s_add_error_count = 0;
6035 	}
6036 	spin_unlock(&sbi->s_error_lock);
6037 
6038 	ext4_superblock_csum_set(sb);
6039 	unlock_buffer(sbh);
6040 }
6041 
6042 static int ext4_commit_super(struct super_block *sb)
6043 {
6044 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6045 
6046 	if (!sbh)
6047 		return -EINVAL;
6048 	if (block_device_ejected(sb))
6049 		return -ENODEV;
6050 
6051 	ext4_update_super(sb);
6052 
6053 	lock_buffer(sbh);
6054 	/* Buffer got discarded which means block device got invalidated */
6055 	if (!buffer_mapped(sbh)) {
6056 		unlock_buffer(sbh);
6057 		return -EIO;
6058 	}
6059 
6060 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6061 		/*
6062 		 * Oh, dear.  A previous attempt to write the
6063 		 * superblock failed.  This could happen because the
6064 		 * USB device was yanked out.  Or it could happen to
6065 		 * be a transient write error and maybe the block will
6066 		 * be remapped.  Nothing we can do but to retry the
6067 		 * write and hope for the best.
6068 		 */
6069 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6070 		       "superblock detected");
6071 		clear_buffer_write_io_error(sbh);
6072 		set_buffer_uptodate(sbh);
6073 	}
6074 	get_bh(sbh);
6075 	/* Clear potential dirty bit if it was journalled update */
6076 	clear_buffer_dirty(sbh);
6077 	sbh->b_end_io = end_buffer_write_sync;
6078 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6079 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6080 	wait_on_buffer(sbh);
6081 	if (buffer_write_io_error(sbh)) {
6082 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6083 		       "superblock");
6084 		clear_buffer_write_io_error(sbh);
6085 		set_buffer_uptodate(sbh);
6086 		return -EIO;
6087 	}
6088 	return 0;
6089 }
6090 
6091 /*
6092  * Have we just finished recovery?  If so, and if we are mounting (or
6093  * remounting) the filesystem readonly, then we will end up with a
6094  * consistent fs on disk.  Record that fact.
6095  */
6096 static int ext4_mark_recovery_complete(struct super_block *sb,
6097 				       struct ext4_super_block *es)
6098 {
6099 	int err;
6100 	journal_t *journal = EXT4_SB(sb)->s_journal;
6101 
6102 	if (!ext4_has_feature_journal(sb)) {
6103 		if (journal != NULL) {
6104 			ext4_error(sb, "Journal got removed while the fs was "
6105 				   "mounted!");
6106 			return -EFSCORRUPTED;
6107 		}
6108 		return 0;
6109 	}
6110 	jbd2_journal_lock_updates(journal);
6111 	err = jbd2_journal_flush(journal, 0);
6112 	if (err < 0)
6113 		goto out;
6114 
6115 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6116 	    ext4_has_feature_orphan_present(sb))) {
6117 		if (!ext4_orphan_file_empty(sb)) {
6118 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6119 			err = -EFSCORRUPTED;
6120 			goto out;
6121 		}
6122 		ext4_clear_feature_journal_needs_recovery(sb);
6123 		ext4_clear_feature_orphan_present(sb);
6124 		ext4_commit_super(sb);
6125 	}
6126 out:
6127 	jbd2_journal_unlock_updates(journal);
6128 	return err;
6129 }
6130 
6131 /*
6132  * If we are mounting (or read-write remounting) a filesystem whose journal
6133  * has recorded an error from a previous lifetime, move that error to the
6134  * main filesystem now.
6135  */
6136 static int ext4_clear_journal_err(struct super_block *sb,
6137 				   struct ext4_super_block *es)
6138 {
6139 	journal_t *journal;
6140 	int j_errno;
6141 	const char *errstr;
6142 
6143 	if (!ext4_has_feature_journal(sb)) {
6144 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6145 		return -EFSCORRUPTED;
6146 	}
6147 
6148 	journal = EXT4_SB(sb)->s_journal;
6149 
6150 	/*
6151 	 * Now check for any error status which may have been recorded in the
6152 	 * journal by a prior ext4_error() or ext4_abort()
6153 	 */
6154 
6155 	j_errno = jbd2_journal_errno(journal);
6156 	if (j_errno) {
6157 		char nbuf[16];
6158 
6159 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6160 		ext4_warning(sb, "Filesystem error recorded "
6161 			     "from previous mount: %s", errstr);
6162 		ext4_warning(sb, "Marking fs in need of filesystem check.");
6163 
6164 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6165 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6166 		ext4_commit_super(sb);
6167 
6168 		jbd2_journal_clear_err(journal);
6169 		jbd2_journal_update_sb_errno(journal);
6170 	}
6171 	return 0;
6172 }
6173 
6174 /*
6175  * Force the running and committing transactions to commit,
6176  * and wait on the commit.
6177  */
6178 int ext4_force_commit(struct super_block *sb)
6179 {
6180 	journal_t *journal;
6181 
6182 	if (sb_rdonly(sb))
6183 		return 0;
6184 
6185 	journal = EXT4_SB(sb)->s_journal;
6186 	return ext4_journal_force_commit(journal);
6187 }
6188 
6189 static int ext4_sync_fs(struct super_block *sb, int wait)
6190 {
6191 	int ret = 0;
6192 	tid_t target;
6193 	bool needs_barrier = false;
6194 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6195 
6196 	if (unlikely(ext4_forced_shutdown(sbi)))
6197 		return 0;
6198 
6199 	trace_ext4_sync_fs(sb, wait);
6200 	flush_workqueue(sbi->rsv_conversion_wq);
6201 	/*
6202 	 * Writeback quota in non-journalled quota case - journalled quota has
6203 	 * no dirty dquots
6204 	 */
6205 	dquot_writeback_dquots(sb, -1);
6206 	/*
6207 	 * Data writeback is possible w/o journal transaction, so barrier must
6208 	 * being sent at the end of the function. But we can skip it if
6209 	 * transaction_commit will do it for us.
6210 	 */
6211 	if (sbi->s_journal) {
6212 		target = jbd2_get_latest_transaction(sbi->s_journal);
6213 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6214 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6215 			needs_barrier = true;
6216 
6217 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6218 			if (wait)
6219 				ret = jbd2_log_wait_commit(sbi->s_journal,
6220 							   target);
6221 		}
6222 	} else if (wait && test_opt(sb, BARRIER))
6223 		needs_barrier = true;
6224 	if (needs_barrier) {
6225 		int err;
6226 		err = blkdev_issue_flush(sb->s_bdev);
6227 		if (!ret)
6228 			ret = err;
6229 	}
6230 
6231 	return ret;
6232 }
6233 
6234 /*
6235  * LVM calls this function before a (read-only) snapshot is created.  This
6236  * gives us a chance to flush the journal completely and mark the fs clean.
6237  *
6238  * Note that only this function cannot bring a filesystem to be in a clean
6239  * state independently. It relies on upper layer to stop all data & metadata
6240  * modifications.
6241  */
6242 static int ext4_freeze(struct super_block *sb)
6243 {
6244 	int error = 0;
6245 	journal_t *journal;
6246 
6247 	if (sb_rdonly(sb))
6248 		return 0;
6249 
6250 	journal = EXT4_SB(sb)->s_journal;
6251 
6252 	if (journal) {
6253 		/* Now we set up the journal barrier. */
6254 		jbd2_journal_lock_updates(journal);
6255 
6256 		/*
6257 		 * Don't clear the needs_recovery flag if we failed to
6258 		 * flush the journal.
6259 		 */
6260 		error = jbd2_journal_flush(journal, 0);
6261 		if (error < 0)
6262 			goto out;
6263 
6264 		/* Journal blocked and flushed, clear needs_recovery flag. */
6265 		ext4_clear_feature_journal_needs_recovery(sb);
6266 		if (ext4_orphan_file_empty(sb))
6267 			ext4_clear_feature_orphan_present(sb);
6268 	}
6269 
6270 	error = ext4_commit_super(sb);
6271 out:
6272 	if (journal)
6273 		/* we rely on upper layer to stop further updates */
6274 		jbd2_journal_unlock_updates(journal);
6275 	return error;
6276 }
6277 
6278 /*
6279  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6280  * flag here, even though the filesystem is not technically dirty yet.
6281  */
6282 static int ext4_unfreeze(struct super_block *sb)
6283 {
6284 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6285 		return 0;
6286 
6287 	if (EXT4_SB(sb)->s_journal) {
6288 		/* Reset the needs_recovery flag before the fs is unlocked. */
6289 		ext4_set_feature_journal_needs_recovery(sb);
6290 		if (ext4_has_feature_orphan_file(sb))
6291 			ext4_set_feature_orphan_present(sb);
6292 	}
6293 
6294 	ext4_commit_super(sb);
6295 	return 0;
6296 }
6297 
6298 /*
6299  * Structure to save mount options for ext4_remount's benefit
6300  */
6301 struct ext4_mount_options {
6302 	unsigned long s_mount_opt;
6303 	unsigned long s_mount_opt2;
6304 	kuid_t s_resuid;
6305 	kgid_t s_resgid;
6306 	unsigned long s_commit_interval;
6307 	u32 s_min_batch_time, s_max_batch_time;
6308 #ifdef CONFIG_QUOTA
6309 	int s_jquota_fmt;
6310 	char *s_qf_names[EXT4_MAXQUOTAS];
6311 #endif
6312 };
6313 
6314 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6315 {
6316 	struct ext4_fs_context *ctx = fc->fs_private;
6317 	struct ext4_super_block *es;
6318 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6319 	unsigned long old_sb_flags;
6320 	struct ext4_mount_options old_opts;
6321 	ext4_group_t g;
6322 	int err = 0;
6323 #ifdef CONFIG_QUOTA
6324 	int enable_quota = 0;
6325 	int i, j;
6326 	char *to_free[EXT4_MAXQUOTAS];
6327 #endif
6328 
6329 
6330 	/* Store the original options */
6331 	old_sb_flags = sb->s_flags;
6332 	old_opts.s_mount_opt = sbi->s_mount_opt;
6333 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6334 	old_opts.s_resuid = sbi->s_resuid;
6335 	old_opts.s_resgid = sbi->s_resgid;
6336 	old_opts.s_commit_interval = sbi->s_commit_interval;
6337 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6338 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6339 #ifdef CONFIG_QUOTA
6340 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6341 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6342 		if (sbi->s_qf_names[i]) {
6343 			char *qf_name = get_qf_name(sb, sbi, i);
6344 
6345 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6346 			if (!old_opts.s_qf_names[i]) {
6347 				for (j = 0; j < i; j++)
6348 					kfree(old_opts.s_qf_names[j]);
6349 				return -ENOMEM;
6350 			}
6351 		} else
6352 			old_opts.s_qf_names[i] = NULL;
6353 #endif
6354 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6355 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6356 			ctx->journal_ioprio =
6357 				sbi->s_journal->j_task->io_context->ioprio;
6358 		else
6359 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6360 
6361 	}
6362 
6363 	ext4_apply_options(fc, sb);
6364 
6365 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6366 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6367 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6368 			 "during remount not supported; ignoring");
6369 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6370 	}
6371 
6372 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6373 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6374 			ext4_msg(sb, KERN_ERR, "can't mount with "
6375 				 "both data=journal and delalloc");
6376 			err = -EINVAL;
6377 			goto restore_opts;
6378 		}
6379 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6380 			ext4_msg(sb, KERN_ERR, "can't mount with "
6381 				 "both data=journal and dioread_nolock");
6382 			err = -EINVAL;
6383 			goto restore_opts;
6384 		}
6385 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6386 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6387 			ext4_msg(sb, KERN_ERR, "can't mount with "
6388 				"journal_async_commit in data=ordered mode");
6389 			err = -EINVAL;
6390 			goto restore_opts;
6391 		}
6392 	}
6393 
6394 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6395 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6396 		err = -EINVAL;
6397 		goto restore_opts;
6398 	}
6399 
6400 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6401 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6402 
6403 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6404 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6405 
6406 	es = sbi->s_es;
6407 
6408 	if (sbi->s_journal) {
6409 		ext4_init_journal_params(sb, sbi->s_journal);
6410 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6411 	}
6412 
6413 	/* Flush outstanding errors before changing fs state */
6414 	flush_work(&sbi->s_error_work);
6415 
6416 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6417 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6418 			err = -EROFS;
6419 			goto restore_opts;
6420 		}
6421 
6422 		if (fc->sb_flags & SB_RDONLY) {
6423 			err = sync_filesystem(sb);
6424 			if (err < 0)
6425 				goto restore_opts;
6426 			err = dquot_suspend(sb, -1);
6427 			if (err < 0)
6428 				goto restore_opts;
6429 
6430 			/*
6431 			 * First of all, the unconditional stuff we have to do
6432 			 * to disable replay of the journal when we next remount
6433 			 */
6434 			sb->s_flags |= SB_RDONLY;
6435 
6436 			/*
6437 			 * OK, test if we are remounting a valid rw partition
6438 			 * readonly, and if so set the rdonly flag and then
6439 			 * mark the partition as valid again.
6440 			 */
6441 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6442 			    (sbi->s_mount_state & EXT4_VALID_FS))
6443 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6444 
6445 			if (sbi->s_journal) {
6446 				/*
6447 				 * We let remount-ro finish even if marking fs
6448 				 * as clean failed...
6449 				 */
6450 				ext4_mark_recovery_complete(sb, es);
6451 			}
6452 		} else {
6453 			/* Make sure we can mount this feature set readwrite */
6454 			if (ext4_has_feature_readonly(sb) ||
6455 			    !ext4_feature_set_ok(sb, 0)) {
6456 				err = -EROFS;
6457 				goto restore_opts;
6458 			}
6459 			/*
6460 			 * Make sure the group descriptor checksums
6461 			 * are sane.  If they aren't, refuse to remount r/w.
6462 			 */
6463 			for (g = 0; g < sbi->s_groups_count; g++) {
6464 				struct ext4_group_desc *gdp =
6465 					ext4_get_group_desc(sb, g, NULL);
6466 
6467 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6468 					ext4_msg(sb, KERN_ERR,
6469 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6470 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6471 					       le16_to_cpu(gdp->bg_checksum));
6472 					err = -EFSBADCRC;
6473 					goto restore_opts;
6474 				}
6475 			}
6476 
6477 			/*
6478 			 * If we have an unprocessed orphan list hanging
6479 			 * around from a previously readonly bdev mount,
6480 			 * require a full umount/remount for now.
6481 			 */
6482 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6483 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6484 				       "remount RDWR because of unprocessed "
6485 				       "orphan inode list.  Please "
6486 				       "umount/remount instead");
6487 				err = -EINVAL;
6488 				goto restore_opts;
6489 			}
6490 
6491 			/*
6492 			 * Mounting a RDONLY partition read-write, so reread
6493 			 * and store the current valid flag.  (It may have
6494 			 * been changed by e2fsck since we originally mounted
6495 			 * the partition.)
6496 			 */
6497 			if (sbi->s_journal) {
6498 				err = ext4_clear_journal_err(sb, es);
6499 				if (err)
6500 					goto restore_opts;
6501 			}
6502 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6503 					      ~EXT4_FC_REPLAY);
6504 
6505 			err = ext4_setup_super(sb, es, 0);
6506 			if (err)
6507 				goto restore_opts;
6508 
6509 			sb->s_flags &= ~SB_RDONLY;
6510 			if (ext4_has_feature_mmp(sb))
6511 				if (ext4_multi_mount_protect(sb,
6512 						le64_to_cpu(es->s_mmp_block))) {
6513 					err = -EROFS;
6514 					goto restore_opts;
6515 				}
6516 #ifdef CONFIG_QUOTA
6517 			enable_quota = 1;
6518 #endif
6519 		}
6520 	}
6521 
6522 	/*
6523 	 * Reinitialize lazy itable initialization thread based on
6524 	 * current settings
6525 	 */
6526 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6527 		ext4_unregister_li_request(sb);
6528 	else {
6529 		ext4_group_t first_not_zeroed;
6530 		first_not_zeroed = ext4_has_uninit_itable(sb);
6531 		ext4_register_li_request(sb, first_not_zeroed);
6532 	}
6533 
6534 	/*
6535 	 * Handle creation of system zone data early because it can fail.
6536 	 * Releasing of existing data is done when we are sure remount will
6537 	 * succeed.
6538 	 */
6539 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6540 		err = ext4_setup_system_zone(sb);
6541 		if (err)
6542 			goto restore_opts;
6543 	}
6544 
6545 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6546 		err = ext4_commit_super(sb);
6547 		if (err)
6548 			goto restore_opts;
6549 	}
6550 
6551 #ifdef CONFIG_QUOTA
6552 	/* Release old quota file names */
6553 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6554 		kfree(old_opts.s_qf_names[i]);
6555 	if (enable_quota) {
6556 		if (sb_any_quota_suspended(sb))
6557 			dquot_resume(sb, -1);
6558 		else if (ext4_has_feature_quota(sb)) {
6559 			err = ext4_enable_quotas(sb);
6560 			if (err)
6561 				goto restore_opts;
6562 		}
6563 	}
6564 #endif
6565 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6566 		ext4_release_system_zone(sb);
6567 
6568 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6569 		ext4_stop_mmpd(sbi);
6570 
6571 	return 0;
6572 
6573 restore_opts:
6574 	sb->s_flags = old_sb_flags;
6575 	sbi->s_mount_opt = old_opts.s_mount_opt;
6576 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6577 	sbi->s_resuid = old_opts.s_resuid;
6578 	sbi->s_resgid = old_opts.s_resgid;
6579 	sbi->s_commit_interval = old_opts.s_commit_interval;
6580 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6581 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6582 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6583 		ext4_release_system_zone(sb);
6584 #ifdef CONFIG_QUOTA
6585 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6586 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6587 		to_free[i] = get_qf_name(sb, sbi, i);
6588 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6589 	}
6590 	synchronize_rcu();
6591 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6592 		kfree(to_free[i]);
6593 #endif
6594 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6595 		ext4_stop_mmpd(sbi);
6596 	return err;
6597 }
6598 
6599 static int ext4_reconfigure(struct fs_context *fc)
6600 {
6601 	struct super_block *sb = fc->root->d_sb;
6602 	int ret;
6603 
6604 	fc->s_fs_info = EXT4_SB(sb);
6605 
6606 	ret = ext4_check_opt_consistency(fc, sb);
6607 	if (ret < 0)
6608 		return ret;
6609 
6610 	ret = __ext4_remount(fc, sb);
6611 	if (ret < 0)
6612 		return ret;
6613 
6614 	ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6615 		 ext4_quota_mode(sb));
6616 
6617 	return 0;
6618 }
6619 
6620 #ifdef CONFIG_QUOTA
6621 static int ext4_statfs_project(struct super_block *sb,
6622 			       kprojid_t projid, struct kstatfs *buf)
6623 {
6624 	struct kqid qid;
6625 	struct dquot *dquot;
6626 	u64 limit;
6627 	u64 curblock;
6628 
6629 	qid = make_kqid_projid(projid);
6630 	dquot = dqget(sb, qid);
6631 	if (IS_ERR(dquot))
6632 		return PTR_ERR(dquot);
6633 	spin_lock(&dquot->dq_dqb_lock);
6634 
6635 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6636 			     dquot->dq_dqb.dqb_bhardlimit);
6637 	limit >>= sb->s_blocksize_bits;
6638 
6639 	if (limit && buf->f_blocks > limit) {
6640 		curblock = (dquot->dq_dqb.dqb_curspace +
6641 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6642 		buf->f_blocks = limit;
6643 		buf->f_bfree = buf->f_bavail =
6644 			(buf->f_blocks > curblock) ?
6645 			 (buf->f_blocks - curblock) : 0;
6646 	}
6647 
6648 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6649 			     dquot->dq_dqb.dqb_ihardlimit);
6650 	if (limit && buf->f_files > limit) {
6651 		buf->f_files = limit;
6652 		buf->f_ffree =
6653 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6654 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6655 	}
6656 
6657 	spin_unlock(&dquot->dq_dqb_lock);
6658 	dqput(dquot);
6659 	return 0;
6660 }
6661 #endif
6662 
6663 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6664 {
6665 	struct super_block *sb = dentry->d_sb;
6666 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6667 	struct ext4_super_block *es = sbi->s_es;
6668 	ext4_fsblk_t overhead = 0, resv_blocks;
6669 	s64 bfree;
6670 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6671 
6672 	if (!test_opt(sb, MINIX_DF))
6673 		overhead = sbi->s_overhead;
6674 
6675 	buf->f_type = EXT4_SUPER_MAGIC;
6676 	buf->f_bsize = sb->s_blocksize;
6677 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6678 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6679 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6680 	/* prevent underflow in case that few free space is available */
6681 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6682 	buf->f_bavail = buf->f_bfree -
6683 			(ext4_r_blocks_count(es) + resv_blocks);
6684 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6685 		buf->f_bavail = 0;
6686 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6687 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6688 	buf->f_namelen = EXT4_NAME_LEN;
6689 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6690 
6691 #ifdef CONFIG_QUOTA
6692 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6693 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6694 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6695 #endif
6696 	return 0;
6697 }
6698 
6699 
6700 #ifdef CONFIG_QUOTA
6701 
6702 /*
6703  * Helper functions so that transaction is started before we acquire dqio_sem
6704  * to keep correct lock ordering of transaction > dqio_sem
6705  */
6706 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6707 {
6708 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6709 }
6710 
6711 static int ext4_write_dquot(struct dquot *dquot)
6712 {
6713 	int ret, err;
6714 	handle_t *handle;
6715 	struct inode *inode;
6716 
6717 	inode = dquot_to_inode(dquot);
6718 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6719 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6720 	if (IS_ERR(handle))
6721 		return PTR_ERR(handle);
6722 	ret = dquot_commit(dquot);
6723 	err = ext4_journal_stop(handle);
6724 	if (!ret)
6725 		ret = err;
6726 	return ret;
6727 }
6728 
6729 static int ext4_acquire_dquot(struct dquot *dquot)
6730 {
6731 	int ret, err;
6732 	handle_t *handle;
6733 
6734 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6735 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6736 	if (IS_ERR(handle))
6737 		return PTR_ERR(handle);
6738 	ret = dquot_acquire(dquot);
6739 	err = ext4_journal_stop(handle);
6740 	if (!ret)
6741 		ret = err;
6742 	return ret;
6743 }
6744 
6745 static int ext4_release_dquot(struct dquot *dquot)
6746 {
6747 	int ret, err;
6748 	handle_t *handle;
6749 
6750 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6751 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6752 	if (IS_ERR(handle)) {
6753 		/* Release dquot anyway to avoid endless cycle in dqput() */
6754 		dquot_release(dquot);
6755 		return PTR_ERR(handle);
6756 	}
6757 	ret = dquot_release(dquot);
6758 	err = ext4_journal_stop(handle);
6759 	if (!ret)
6760 		ret = err;
6761 	return ret;
6762 }
6763 
6764 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6765 {
6766 	struct super_block *sb = dquot->dq_sb;
6767 
6768 	if (ext4_is_quota_journalled(sb)) {
6769 		dquot_mark_dquot_dirty(dquot);
6770 		return ext4_write_dquot(dquot);
6771 	} else {
6772 		return dquot_mark_dquot_dirty(dquot);
6773 	}
6774 }
6775 
6776 static int ext4_write_info(struct super_block *sb, int type)
6777 {
6778 	int ret, err;
6779 	handle_t *handle;
6780 
6781 	/* Data block + inode block */
6782 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6783 	if (IS_ERR(handle))
6784 		return PTR_ERR(handle);
6785 	ret = dquot_commit_info(sb, type);
6786 	err = ext4_journal_stop(handle);
6787 	if (!ret)
6788 		ret = err;
6789 	return ret;
6790 }
6791 
6792 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6793 {
6794 	struct ext4_inode_info *ei = EXT4_I(inode);
6795 
6796 	/* The first argument of lockdep_set_subclass has to be
6797 	 * *exactly* the same as the argument to init_rwsem() --- in
6798 	 * this case, in init_once() --- or lockdep gets unhappy
6799 	 * because the name of the lock is set using the
6800 	 * stringification of the argument to init_rwsem().
6801 	 */
6802 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6803 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6804 }
6805 
6806 /*
6807  * Standard function to be called on quota_on
6808  */
6809 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6810 			 const struct path *path)
6811 {
6812 	int err;
6813 
6814 	if (!test_opt(sb, QUOTA))
6815 		return -EINVAL;
6816 
6817 	/* Quotafile not on the same filesystem? */
6818 	if (path->dentry->d_sb != sb)
6819 		return -EXDEV;
6820 
6821 	/* Quota already enabled for this file? */
6822 	if (IS_NOQUOTA(d_inode(path->dentry)))
6823 		return -EBUSY;
6824 
6825 	/* Journaling quota? */
6826 	if (EXT4_SB(sb)->s_qf_names[type]) {
6827 		/* Quotafile not in fs root? */
6828 		if (path->dentry->d_parent != sb->s_root)
6829 			ext4_msg(sb, KERN_WARNING,
6830 				"Quota file not on filesystem root. "
6831 				"Journaled quota will not work");
6832 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6833 	} else {
6834 		/*
6835 		 * Clear the flag just in case mount options changed since
6836 		 * last time.
6837 		 */
6838 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6839 	}
6840 
6841 	/*
6842 	 * When we journal data on quota file, we have to flush journal to see
6843 	 * all updates to the file when we bypass pagecache...
6844 	 */
6845 	if (EXT4_SB(sb)->s_journal &&
6846 	    ext4_should_journal_data(d_inode(path->dentry))) {
6847 		/*
6848 		 * We don't need to lock updates but journal_flush() could
6849 		 * otherwise be livelocked...
6850 		 */
6851 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6852 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6853 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6854 		if (err)
6855 			return err;
6856 	}
6857 
6858 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6859 	err = dquot_quota_on(sb, type, format_id, path);
6860 	if (!err) {
6861 		struct inode *inode = d_inode(path->dentry);
6862 		handle_t *handle;
6863 
6864 		/*
6865 		 * Set inode flags to prevent userspace from messing with quota
6866 		 * files. If this fails, we return success anyway since quotas
6867 		 * are already enabled and this is not a hard failure.
6868 		 */
6869 		inode_lock(inode);
6870 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6871 		if (IS_ERR(handle))
6872 			goto unlock_inode;
6873 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6874 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6875 				S_NOATIME | S_IMMUTABLE);
6876 		err = ext4_mark_inode_dirty(handle, inode);
6877 		ext4_journal_stop(handle);
6878 	unlock_inode:
6879 		inode_unlock(inode);
6880 		if (err)
6881 			dquot_quota_off(sb, type);
6882 	}
6883 	if (err)
6884 		lockdep_set_quota_inode(path->dentry->d_inode,
6885 					     I_DATA_SEM_NORMAL);
6886 	return err;
6887 }
6888 
6889 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6890 			     unsigned int flags)
6891 {
6892 	int err;
6893 	struct inode *qf_inode;
6894 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6895 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6896 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6897 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6898 	};
6899 
6900 	BUG_ON(!ext4_has_feature_quota(sb));
6901 
6902 	if (!qf_inums[type])
6903 		return -EPERM;
6904 
6905 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6906 	if (IS_ERR(qf_inode)) {
6907 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6908 		return PTR_ERR(qf_inode);
6909 	}
6910 
6911 	/* Don't account quota for quota files to avoid recursion */
6912 	qf_inode->i_flags |= S_NOQUOTA;
6913 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6914 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6915 	if (err)
6916 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6917 	iput(qf_inode);
6918 
6919 	return err;
6920 }
6921 
6922 /* Enable usage tracking for all quota types. */
6923 int ext4_enable_quotas(struct super_block *sb)
6924 {
6925 	int type, err = 0;
6926 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6927 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6928 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6929 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6930 	};
6931 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6932 		test_opt(sb, USRQUOTA),
6933 		test_opt(sb, GRPQUOTA),
6934 		test_opt(sb, PRJQUOTA),
6935 	};
6936 
6937 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6938 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6939 		if (qf_inums[type]) {
6940 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6941 				DQUOT_USAGE_ENABLED |
6942 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6943 			if (err) {
6944 				ext4_warning(sb,
6945 					"Failed to enable quota tracking "
6946 					"(type=%d, err=%d). Please run "
6947 					"e2fsck to fix.", type, err);
6948 				for (type--; type >= 0; type--) {
6949 					struct inode *inode;
6950 
6951 					inode = sb_dqopt(sb)->files[type];
6952 					if (inode)
6953 						inode = igrab(inode);
6954 					dquot_quota_off(sb, type);
6955 					if (inode) {
6956 						lockdep_set_quota_inode(inode,
6957 							I_DATA_SEM_NORMAL);
6958 						iput(inode);
6959 					}
6960 				}
6961 
6962 				return err;
6963 			}
6964 		}
6965 	}
6966 	return 0;
6967 }
6968 
6969 static int ext4_quota_off(struct super_block *sb, int type)
6970 {
6971 	struct inode *inode = sb_dqopt(sb)->files[type];
6972 	handle_t *handle;
6973 	int err;
6974 
6975 	/* Force all delayed allocation blocks to be allocated.
6976 	 * Caller already holds s_umount sem */
6977 	if (test_opt(sb, DELALLOC))
6978 		sync_filesystem(sb);
6979 
6980 	if (!inode || !igrab(inode))
6981 		goto out;
6982 
6983 	err = dquot_quota_off(sb, type);
6984 	if (err || ext4_has_feature_quota(sb))
6985 		goto out_put;
6986 
6987 	inode_lock(inode);
6988 	/*
6989 	 * Update modification times of quota files when userspace can
6990 	 * start looking at them. If we fail, we return success anyway since
6991 	 * this is not a hard failure and quotas are already disabled.
6992 	 */
6993 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6994 	if (IS_ERR(handle)) {
6995 		err = PTR_ERR(handle);
6996 		goto out_unlock;
6997 	}
6998 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6999 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7000 	inode->i_mtime = inode->i_ctime = current_time(inode);
7001 	err = ext4_mark_inode_dirty(handle, inode);
7002 	ext4_journal_stop(handle);
7003 out_unlock:
7004 	inode_unlock(inode);
7005 out_put:
7006 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7007 	iput(inode);
7008 	return err;
7009 out:
7010 	return dquot_quota_off(sb, type);
7011 }
7012 
7013 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7014  * acquiring the locks... As quota files are never truncated and quota code
7015  * itself serializes the operations (and no one else should touch the files)
7016  * we don't have to be afraid of races */
7017 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7018 			       size_t len, loff_t off)
7019 {
7020 	struct inode *inode = sb_dqopt(sb)->files[type];
7021 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7022 	int offset = off & (sb->s_blocksize - 1);
7023 	int tocopy;
7024 	size_t toread;
7025 	struct buffer_head *bh;
7026 	loff_t i_size = i_size_read(inode);
7027 
7028 	if (off > i_size)
7029 		return 0;
7030 	if (off+len > i_size)
7031 		len = i_size-off;
7032 	toread = len;
7033 	while (toread > 0) {
7034 		tocopy = sb->s_blocksize - offset < toread ?
7035 				sb->s_blocksize - offset : toread;
7036 		bh = ext4_bread(NULL, inode, blk, 0);
7037 		if (IS_ERR(bh))
7038 			return PTR_ERR(bh);
7039 		if (!bh)	/* A hole? */
7040 			memset(data, 0, tocopy);
7041 		else
7042 			memcpy(data, bh->b_data+offset, tocopy);
7043 		brelse(bh);
7044 		offset = 0;
7045 		toread -= tocopy;
7046 		data += tocopy;
7047 		blk++;
7048 	}
7049 	return len;
7050 }
7051 
7052 /* Write to quotafile (we know the transaction is already started and has
7053  * enough credits) */
7054 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7055 				const char *data, size_t len, loff_t off)
7056 {
7057 	struct inode *inode = sb_dqopt(sb)->files[type];
7058 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7059 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7060 	int retries = 0;
7061 	struct buffer_head *bh;
7062 	handle_t *handle = journal_current_handle();
7063 
7064 	if (!handle) {
7065 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7066 			" cancelled because transaction is not started",
7067 			(unsigned long long)off, (unsigned long long)len);
7068 		return -EIO;
7069 	}
7070 	/*
7071 	 * Since we account only one data block in transaction credits,
7072 	 * then it is impossible to cross a block boundary.
7073 	 */
7074 	if (sb->s_blocksize - offset < len) {
7075 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7076 			" cancelled because not block aligned",
7077 			(unsigned long long)off, (unsigned long long)len);
7078 		return -EIO;
7079 	}
7080 
7081 	do {
7082 		bh = ext4_bread(handle, inode, blk,
7083 				EXT4_GET_BLOCKS_CREATE |
7084 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7085 	} while (PTR_ERR(bh) == -ENOSPC &&
7086 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7087 	if (IS_ERR(bh))
7088 		return PTR_ERR(bh);
7089 	if (!bh)
7090 		goto out;
7091 	BUFFER_TRACE(bh, "get write access");
7092 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7093 	if (err) {
7094 		brelse(bh);
7095 		return err;
7096 	}
7097 	lock_buffer(bh);
7098 	memcpy(bh->b_data+offset, data, len);
7099 	flush_dcache_page(bh->b_page);
7100 	unlock_buffer(bh);
7101 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7102 	brelse(bh);
7103 out:
7104 	if (inode->i_size < off + len) {
7105 		i_size_write(inode, off + len);
7106 		EXT4_I(inode)->i_disksize = inode->i_size;
7107 		err2 = ext4_mark_inode_dirty(handle, inode);
7108 		if (unlikely(err2 && !err))
7109 			err = err2;
7110 	}
7111 	return err ? err : len;
7112 }
7113 #endif
7114 
7115 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7116 static inline void register_as_ext2(void)
7117 {
7118 	int err = register_filesystem(&ext2_fs_type);
7119 	if (err)
7120 		printk(KERN_WARNING
7121 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7122 }
7123 
7124 static inline void unregister_as_ext2(void)
7125 {
7126 	unregister_filesystem(&ext2_fs_type);
7127 }
7128 
7129 static inline int ext2_feature_set_ok(struct super_block *sb)
7130 {
7131 	if (ext4_has_unknown_ext2_incompat_features(sb))
7132 		return 0;
7133 	if (sb_rdonly(sb))
7134 		return 1;
7135 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7136 		return 0;
7137 	return 1;
7138 }
7139 #else
7140 static inline void register_as_ext2(void) { }
7141 static inline void unregister_as_ext2(void) { }
7142 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7143 #endif
7144 
7145 static inline void register_as_ext3(void)
7146 {
7147 	int err = register_filesystem(&ext3_fs_type);
7148 	if (err)
7149 		printk(KERN_WARNING
7150 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7151 }
7152 
7153 static inline void unregister_as_ext3(void)
7154 {
7155 	unregister_filesystem(&ext3_fs_type);
7156 }
7157 
7158 static inline int ext3_feature_set_ok(struct super_block *sb)
7159 {
7160 	if (ext4_has_unknown_ext3_incompat_features(sb))
7161 		return 0;
7162 	if (!ext4_has_feature_journal(sb))
7163 		return 0;
7164 	if (sb_rdonly(sb))
7165 		return 1;
7166 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7167 		return 0;
7168 	return 1;
7169 }
7170 
7171 static struct file_system_type ext4_fs_type = {
7172 	.owner			= THIS_MODULE,
7173 	.name			= "ext4",
7174 	.init_fs_context	= ext4_init_fs_context,
7175 	.parameters		= ext4_param_specs,
7176 	.kill_sb		= kill_block_super,
7177 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7178 };
7179 MODULE_ALIAS_FS("ext4");
7180 
7181 /* Shared across all ext4 file systems */
7182 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7183 
7184 static int __init ext4_init_fs(void)
7185 {
7186 	int i, err;
7187 
7188 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7189 	ext4_li_info = NULL;
7190 
7191 	/* Build-time check for flags consistency */
7192 	ext4_check_flag_values();
7193 
7194 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7195 		init_waitqueue_head(&ext4__ioend_wq[i]);
7196 
7197 	err = ext4_init_es();
7198 	if (err)
7199 		return err;
7200 
7201 	err = ext4_init_pending();
7202 	if (err)
7203 		goto out7;
7204 
7205 	err = ext4_init_post_read_processing();
7206 	if (err)
7207 		goto out6;
7208 
7209 	err = ext4_init_pageio();
7210 	if (err)
7211 		goto out5;
7212 
7213 	err = ext4_init_system_zone();
7214 	if (err)
7215 		goto out4;
7216 
7217 	err = ext4_init_sysfs();
7218 	if (err)
7219 		goto out3;
7220 
7221 	err = ext4_init_mballoc();
7222 	if (err)
7223 		goto out2;
7224 	err = init_inodecache();
7225 	if (err)
7226 		goto out1;
7227 
7228 	err = ext4_fc_init_dentry_cache();
7229 	if (err)
7230 		goto out05;
7231 
7232 	register_as_ext3();
7233 	register_as_ext2();
7234 	err = register_filesystem(&ext4_fs_type);
7235 	if (err)
7236 		goto out;
7237 
7238 	return 0;
7239 out:
7240 	unregister_as_ext2();
7241 	unregister_as_ext3();
7242 	ext4_fc_destroy_dentry_cache();
7243 out05:
7244 	destroy_inodecache();
7245 out1:
7246 	ext4_exit_mballoc();
7247 out2:
7248 	ext4_exit_sysfs();
7249 out3:
7250 	ext4_exit_system_zone();
7251 out4:
7252 	ext4_exit_pageio();
7253 out5:
7254 	ext4_exit_post_read_processing();
7255 out6:
7256 	ext4_exit_pending();
7257 out7:
7258 	ext4_exit_es();
7259 
7260 	return err;
7261 }
7262 
7263 static void __exit ext4_exit_fs(void)
7264 {
7265 	ext4_destroy_lazyinit_thread();
7266 	unregister_as_ext2();
7267 	unregister_as_ext3();
7268 	unregister_filesystem(&ext4_fs_type);
7269 	ext4_fc_destroy_dentry_cache();
7270 	destroy_inodecache();
7271 	ext4_exit_mballoc();
7272 	ext4_exit_sysfs();
7273 	ext4_exit_system_zone();
7274 	ext4_exit_pageio();
7275 	ext4_exit_post_read_processing();
7276 	ext4_exit_es();
7277 	ext4_exit_pending();
7278 }
7279 
7280 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7281 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7282 MODULE_LICENSE("GPL");
7283 MODULE_SOFTDEP("pre: crc32c");
7284 module_init(ext4_init_fs)
7285 module_exit(ext4_exit_fs)
7286