xref: /openbmc/linux/fs/ext4/super.c (revision 7559e757)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= kill_block_super,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= kill_block_super,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ | op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
207 {
208 	lock_buffer(bh);
209 	if (!wait) {
210 		ext4_read_bh_nowait(bh, op_flags, NULL);
211 		return 0;
212 	}
213 	return ext4_read_bh(bh, op_flags, NULL);
214 }
215 
216 /*
217  * This works like __bread_gfp() except it uses ERR_PTR for error
218  * returns.  Currently with sb_bread it's impossible to distinguish
219  * between ENOMEM and EIO situations (since both result in a NULL
220  * return.
221  */
222 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
223 					       sector_t block,
224 					       blk_opf_t op_flags, gfp_t gfp)
225 {
226 	struct buffer_head *bh;
227 	int ret;
228 
229 	bh = sb_getblk_gfp(sb, block, gfp);
230 	if (bh == NULL)
231 		return ERR_PTR(-ENOMEM);
232 	if (ext4_buffer_uptodate(bh))
233 		return bh;
234 
235 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
236 	if (ret) {
237 		put_bh(bh);
238 		return ERR_PTR(ret);
239 	}
240 	return bh;
241 }
242 
243 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
244 				   blk_opf_t op_flags)
245 {
246 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
247 }
248 
249 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
250 					    sector_t block)
251 {
252 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
253 }
254 
255 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
256 {
257 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
258 
259 	if (likely(bh)) {
260 		if (trylock_buffer(bh))
261 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
262 		brelse(bh);
263 	}
264 }
265 
266 static int ext4_verify_csum_type(struct super_block *sb,
267 				 struct ext4_super_block *es)
268 {
269 	if (!ext4_has_feature_metadata_csum(sb))
270 		return 1;
271 
272 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
273 }
274 
275 __le32 ext4_superblock_csum(struct super_block *sb,
276 			    struct ext4_super_block *es)
277 {
278 	struct ext4_sb_info *sbi = EXT4_SB(sb);
279 	int offset = offsetof(struct ext4_super_block, s_checksum);
280 	__u32 csum;
281 
282 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
283 
284 	return cpu_to_le32(csum);
285 }
286 
287 static int ext4_superblock_csum_verify(struct super_block *sb,
288 				       struct ext4_super_block *es)
289 {
290 	if (!ext4_has_metadata_csum(sb))
291 		return 1;
292 
293 	return es->s_checksum == ext4_superblock_csum(sb, es);
294 }
295 
296 void ext4_superblock_csum_set(struct super_block *sb)
297 {
298 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
299 
300 	if (!ext4_has_metadata_csum(sb))
301 		return;
302 
303 	es->s_checksum = ext4_superblock_csum(sb, es);
304 }
305 
306 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
307 			       struct ext4_group_desc *bg)
308 {
309 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
310 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
311 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
312 }
313 
314 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
323 			      struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_table_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
328 }
329 
330 __u32 ext4_free_group_clusters(struct super_block *sb,
331 			       struct ext4_group_desc *bg)
332 {
333 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
336 }
337 
338 __u32 ext4_free_inodes_count(struct super_block *sb,
339 			      struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_used_dirs_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
352 }
353 
354 __u32 ext4_itable_unused_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_itable_unused_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
360 }
361 
362 void ext4_block_bitmap_set(struct super_block *sb,
363 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
364 {
365 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
366 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
367 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
368 }
369 
370 void ext4_inode_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_table_set(struct super_block *sb,
379 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_free_group_clusters_set(struct super_block *sb,
387 				  struct ext4_group_desc *bg, __u32 count)
388 {
389 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
392 }
393 
394 void ext4_free_inodes_set(struct super_block *sb,
395 			  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_used_dirs_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
408 }
409 
410 void ext4_itable_unused_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
416 }
417 
418 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
419 {
420 	now = clamp_val(now, 0, (1ull << 40) - 1);
421 
422 	*lo = cpu_to_le32(lower_32_bits(now));
423 	*hi = upper_32_bits(now);
424 }
425 
426 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
427 {
428 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
429 }
430 #define ext4_update_tstamp(es, tstamp) \
431 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
432 			     ktime_get_real_seconds())
433 #define ext4_get_tstamp(es, tstamp) \
434 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
435 
436 /*
437  * The del_gendisk() function uninitializes the disk-specific data
438  * structures, including the bdi structure, without telling anyone
439  * else.  Once this happens, any attempt to call mark_buffer_dirty()
440  * (for example, by ext4_commit_super), will cause a kernel OOPS.
441  * This is a kludge to prevent these oops until we can put in a proper
442  * hook in del_gendisk() to inform the VFS and file system layers.
443  */
444 static int block_device_ejected(struct super_block *sb)
445 {
446 	struct inode *bd_inode = sb->s_bdev->bd_inode;
447 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
448 
449 	return bdi->dev == NULL;
450 }
451 
452 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
453 {
454 	struct super_block		*sb = journal->j_private;
455 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
456 	int				error = is_journal_aborted(journal);
457 	struct ext4_journal_cb_entry	*jce;
458 
459 	BUG_ON(txn->t_state == T_FINISHED);
460 
461 	ext4_process_freed_data(sb, txn->t_tid);
462 
463 	spin_lock(&sbi->s_md_lock);
464 	while (!list_empty(&txn->t_private_list)) {
465 		jce = list_entry(txn->t_private_list.next,
466 				 struct ext4_journal_cb_entry, jce_list);
467 		list_del_init(&jce->jce_list);
468 		spin_unlock(&sbi->s_md_lock);
469 		jce->jce_func(sb, jce, error);
470 		spin_lock(&sbi->s_md_lock);
471 	}
472 	spin_unlock(&sbi->s_md_lock);
473 }
474 
475 /*
476  * This writepage callback for write_cache_pages()
477  * takes care of a few cases after page cleaning.
478  *
479  * write_cache_pages() already checks for dirty pages
480  * and calls clear_page_dirty_for_io(), which we want,
481  * to write protect the pages.
482  *
483  * However, we may have to redirty a page (see below.)
484  */
485 static int ext4_journalled_writepage_callback(struct folio *folio,
486 					      struct writeback_control *wbc,
487 					      void *data)
488 {
489 	transaction_t *transaction = (transaction_t *) data;
490 	struct buffer_head *bh, *head;
491 	struct journal_head *jh;
492 
493 	bh = head = folio_buffers(folio);
494 	do {
495 		/*
496 		 * We have to redirty a page in these cases:
497 		 * 1) If buffer is dirty, it means the page was dirty because it
498 		 * contains a buffer that needs checkpointing. So the dirty bit
499 		 * needs to be preserved so that checkpointing writes the buffer
500 		 * properly.
501 		 * 2) If buffer is not part of the committing transaction
502 		 * (we may have just accidentally come across this buffer because
503 		 * inode range tracking is not exact) or if the currently running
504 		 * transaction already contains this buffer as well, dirty bit
505 		 * needs to be preserved so that the buffer gets writeprotected
506 		 * properly on running transaction's commit.
507 		 */
508 		jh = bh2jh(bh);
509 		if (buffer_dirty(bh) ||
510 		    (jh && (jh->b_transaction != transaction ||
511 			    jh->b_next_transaction))) {
512 			folio_redirty_for_writepage(wbc, folio);
513 			goto out;
514 		}
515 	} while ((bh = bh->b_this_page) != head);
516 
517 out:
518 	return AOP_WRITEPAGE_ACTIVATE;
519 }
520 
521 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
522 {
523 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
524 	struct writeback_control wbc = {
525 		.sync_mode =  WB_SYNC_ALL,
526 		.nr_to_write = LONG_MAX,
527 		.range_start = jinode->i_dirty_start,
528 		.range_end = jinode->i_dirty_end,
529         };
530 
531 	return write_cache_pages(mapping, &wbc,
532 				 ext4_journalled_writepage_callback,
533 				 jinode->i_transaction);
534 }
535 
536 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
537 {
538 	int ret;
539 
540 	if (ext4_should_journal_data(jinode->i_vfs_inode))
541 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
542 	else
543 		ret = ext4_normal_submit_inode_data_buffers(jinode);
544 	return ret;
545 }
546 
547 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
548 {
549 	int ret = 0;
550 
551 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
552 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
553 
554 	return ret;
555 }
556 
557 static bool system_going_down(void)
558 {
559 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
560 		|| system_state == SYSTEM_RESTART;
561 }
562 
563 struct ext4_err_translation {
564 	int code;
565 	int errno;
566 };
567 
568 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
569 
570 static struct ext4_err_translation err_translation[] = {
571 	EXT4_ERR_TRANSLATE(EIO),
572 	EXT4_ERR_TRANSLATE(ENOMEM),
573 	EXT4_ERR_TRANSLATE(EFSBADCRC),
574 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
575 	EXT4_ERR_TRANSLATE(ENOSPC),
576 	EXT4_ERR_TRANSLATE(ENOKEY),
577 	EXT4_ERR_TRANSLATE(EROFS),
578 	EXT4_ERR_TRANSLATE(EFBIG),
579 	EXT4_ERR_TRANSLATE(EEXIST),
580 	EXT4_ERR_TRANSLATE(ERANGE),
581 	EXT4_ERR_TRANSLATE(EOVERFLOW),
582 	EXT4_ERR_TRANSLATE(EBUSY),
583 	EXT4_ERR_TRANSLATE(ENOTDIR),
584 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
585 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
586 	EXT4_ERR_TRANSLATE(EFAULT),
587 };
588 
589 static int ext4_errno_to_code(int errno)
590 {
591 	int i;
592 
593 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
594 		if (err_translation[i].errno == errno)
595 			return err_translation[i].code;
596 	return EXT4_ERR_UNKNOWN;
597 }
598 
599 static void save_error_info(struct super_block *sb, int error,
600 			    __u32 ino, __u64 block,
601 			    const char *func, unsigned int line)
602 {
603 	struct ext4_sb_info *sbi = EXT4_SB(sb);
604 
605 	/* We default to EFSCORRUPTED error... */
606 	if (error == 0)
607 		error = EFSCORRUPTED;
608 
609 	spin_lock(&sbi->s_error_lock);
610 	sbi->s_add_error_count++;
611 	sbi->s_last_error_code = error;
612 	sbi->s_last_error_line = line;
613 	sbi->s_last_error_ino = ino;
614 	sbi->s_last_error_block = block;
615 	sbi->s_last_error_func = func;
616 	sbi->s_last_error_time = ktime_get_real_seconds();
617 	if (!sbi->s_first_error_time) {
618 		sbi->s_first_error_code = error;
619 		sbi->s_first_error_line = line;
620 		sbi->s_first_error_ino = ino;
621 		sbi->s_first_error_block = block;
622 		sbi->s_first_error_func = func;
623 		sbi->s_first_error_time = sbi->s_last_error_time;
624 	}
625 	spin_unlock(&sbi->s_error_lock);
626 }
627 
628 /* Deal with the reporting of failure conditions on a filesystem such as
629  * inconsistencies detected or read IO failures.
630  *
631  * On ext2, we can store the error state of the filesystem in the
632  * superblock.  That is not possible on ext4, because we may have other
633  * write ordering constraints on the superblock which prevent us from
634  * writing it out straight away; and given that the journal is about to
635  * be aborted, we can't rely on the current, or future, transactions to
636  * write out the superblock safely.
637  *
638  * We'll just use the jbd2_journal_abort() error code to record an error in
639  * the journal instead.  On recovery, the journal will complain about
640  * that error until we've noted it down and cleared it.
641  *
642  * If force_ro is set, we unconditionally force the filesystem into an
643  * ABORT|READONLY state, unless the error response on the fs has been set to
644  * panic in which case we take the easy way out and panic immediately. This is
645  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
646  * at a critical moment in log management.
647  */
648 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
649 			      __u32 ino, __u64 block,
650 			      const char *func, unsigned int line)
651 {
652 	journal_t *journal = EXT4_SB(sb)->s_journal;
653 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
654 
655 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
656 	if (test_opt(sb, WARN_ON_ERROR))
657 		WARN_ON_ONCE(1);
658 
659 	if (!continue_fs && !sb_rdonly(sb)) {
660 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
661 		if (journal)
662 			jbd2_journal_abort(journal, -EIO);
663 	}
664 
665 	if (!bdev_read_only(sb->s_bdev)) {
666 		save_error_info(sb, error, ino, block, func, line);
667 		/*
668 		 * In case the fs should keep running, we need to writeout
669 		 * superblock through the journal. Due to lock ordering
670 		 * constraints, it may not be safe to do it right here so we
671 		 * defer superblock flushing to a workqueue.
672 		 */
673 		if (continue_fs && journal)
674 			schedule_work(&EXT4_SB(sb)->s_error_work);
675 		else
676 			ext4_commit_super(sb);
677 	}
678 
679 	/*
680 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
681 	 * could panic during 'reboot -f' as the underlying device got already
682 	 * disabled.
683 	 */
684 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
685 		panic("EXT4-fs (device %s): panic forced after error\n",
686 			sb->s_id);
687 	}
688 
689 	if (sb_rdonly(sb) || continue_fs)
690 		return;
691 
692 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
693 	/*
694 	 * Make sure updated value of ->s_mount_flags will be visible before
695 	 * ->s_flags update
696 	 */
697 	smp_wmb();
698 	sb->s_flags |= SB_RDONLY;
699 }
700 
701 static void flush_stashed_error_work(struct work_struct *work)
702 {
703 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
704 						s_error_work);
705 	journal_t *journal = sbi->s_journal;
706 	handle_t *handle;
707 
708 	/*
709 	 * If the journal is still running, we have to write out superblock
710 	 * through the journal to avoid collisions of other journalled sb
711 	 * updates.
712 	 *
713 	 * We use directly jbd2 functions here to avoid recursing back into
714 	 * ext4 error handling code during handling of previous errors.
715 	 */
716 	if (!sb_rdonly(sbi->s_sb) && journal) {
717 		struct buffer_head *sbh = sbi->s_sbh;
718 		handle = jbd2_journal_start(journal, 1);
719 		if (IS_ERR(handle))
720 			goto write_directly;
721 		if (jbd2_journal_get_write_access(handle, sbh)) {
722 			jbd2_journal_stop(handle);
723 			goto write_directly;
724 		}
725 		ext4_update_super(sbi->s_sb);
726 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
727 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
728 				 "superblock detected");
729 			clear_buffer_write_io_error(sbh);
730 			set_buffer_uptodate(sbh);
731 		}
732 
733 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
734 			jbd2_journal_stop(handle);
735 			goto write_directly;
736 		}
737 		jbd2_journal_stop(handle);
738 		ext4_notify_error_sysfs(sbi);
739 		return;
740 	}
741 write_directly:
742 	/*
743 	 * Write through journal failed. Write sb directly to get error info
744 	 * out and hope for the best.
745 	 */
746 	ext4_commit_super(sbi->s_sb);
747 	ext4_notify_error_sysfs(sbi);
748 }
749 
750 #define ext4_error_ratelimit(sb)					\
751 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
752 			     "EXT4-fs error")
753 
754 void __ext4_error(struct super_block *sb, const char *function,
755 		  unsigned int line, bool force_ro, int error, __u64 block,
756 		  const char *fmt, ...)
757 {
758 	struct va_format vaf;
759 	va_list args;
760 
761 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
762 		return;
763 
764 	trace_ext4_error(sb, function, line);
765 	if (ext4_error_ratelimit(sb)) {
766 		va_start(args, fmt);
767 		vaf.fmt = fmt;
768 		vaf.va = &args;
769 		printk(KERN_CRIT
770 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
771 		       sb->s_id, function, line, current->comm, &vaf);
772 		va_end(args);
773 	}
774 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
775 
776 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
777 }
778 
779 void __ext4_error_inode(struct inode *inode, const char *function,
780 			unsigned int line, ext4_fsblk_t block, int error,
781 			const char *fmt, ...)
782 {
783 	va_list args;
784 	struct va_format vaf;
785 
786 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
787 		return;
788 
789 	trace_ext4_error(inode->i_sb, function, line);
790 	if (ext4_error_ratelimit(inode->i_sb)) {
791 		va_start(args, fmt);
792 		vaf.fmt = fmt;
793 		vaf.va = &args;
794 		if (block)
795 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
796 			       "inode #%lu: block %llu: comm %s: %pV\n",
797 			       inode->i_sb->s_id, function, line, inode->i_ino,
798 			       block, current->comm, &vaf);
799 		else
800 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
801 			       "inode #%lu: comm %s: %pV\n",
802 			       inode->i_sb->s_id, function, line, inode->i_ino,
803 			       current->comm, &vaf);
804 		va_end(args);
805 	}
806 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
807 
808 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
809 			  function, line);
810 }
811 
812 void __ext4_error_file(struct file *file, const char *function,
813 		       unsigned int line, ext4_fsblk_t block,
814 		       const char *fmt, ...)
815 {
816 	va_list args;
817 	struct va_format vaf;
818 	struct inode *inode = file_inode(file);
819 	char pathname[80], *path;
820 
821 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
822 		return;
823 
824 	trace_ext4_error(inode->i_sb, function, line);
825 	if (ext4_error_ratelimit(inode->i_sb)) {
826 		path = file_path(file, pathname, sizeof(pathname));
827 		if (IS_ERR(path))
828 			path = "(unknown)";
829 		va_start(args, fmt);
830 		vaf.fmt = fmt;
831 		vaf.va = &args;
832 		if (block)
833 			printk(KERN_CRIT
834 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
835 			       "block %llu: comm %s: path %s: %pV\n",
836 			       inode->i_sb->s_id, function, line, inode->i_ino,
837 			       block, current->comm, path, &vaf);
838 		else
839 			printk(KERN_CRIT
840 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
841 			       "comm %s: path %s: %pV\n",
842 			       inode->i_sb->s_id, function, line, inode->i_ino,
843 			       current->comm, path, &vaf);
844 		va_end(args);
845 	}
846 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
847 
848 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
849 			  function, line);
850 }
851 
852 const char *ext4_decode_error(struct super_block *sb, int errno,
853 			      char nbuf[16])
854 {
855 	char *errstr = NULL;
856 
857 	switch (errno) {
858 	case -EFSCORRUPTED:
859 		errstr = "Corrupt filesystem";
860 		break;
861 	case -EFSBADCRC:
862 		errstr = "Filesystem failed CRC";
863 		break;
864 	case -EIO:
865 		errstr = "IO failure";
866 		break;
867 	case -ENOMEM:
868 		errstr = "Out of memory";
869 		break;
870 	case -EROFS:
871 		if (!sb || (EXT4_SB(sb)->s_journal &&
872 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
873 			errstr = "Journal has aborted";
874 		else
875 			errstr = "Readonly filesystem";
876 		break;
877 	default:
878 		/* If the caller passed in an extra buffer for unknown
879 		 * errors, textualise them now.  Else we just return
880 		 * NULL. */
881 		if (nbuf) {
882 			/* Check for truncated error codes... */
883 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
884 				errstr = nbuf;
885 		}
886 		break;
887 	}
888 
889 	return errstr;
890 }
891 
892 /* __ext4_std_error decodes expected errors from journaling functions
893  * automatically and invokes the appropriate error response.  */
894 
895 void __ext4_std_error(struct super_block *sb, const char *function,
896 		      unsigned int line, int errno)
897 {
898 	char nbuf[16];
899 	const char *errstr;
900 
901 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
902 		return;
903 
904 	/* Special case: if the error is EROFS, and we're not already
905 	 * inside a transaction, then there's really no point in logging
906 	 * an error. */
907 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
908 		return;
909 
910 	if (ext4_error_ratelimit(sb)) {
911 		errstr = ext4_decode_error(sb, errno, nbuf);
912 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
913 		       sb->s_id, function, line, errstr);
914 	}
915 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
916 
917 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
918 }
919 
920 void __ext4_msg(struct super_block *sb,
921 		const char *prefix, const char *fmt, ...)
922 {
923 	struct va_format vaf;
924 	va_list args;
925 
926 	if (sb) {
927 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
928 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
929 				  "EXT4-fs"))
930 			return;
931 	}
932 
933 	va_start(args, fmt);
934 	vaf.fmt = fmt;
935 	vaf.va = &args;
936 	if (sb)
937 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
938 	else
939 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
940 	va_end(args);
941 }
942 
943 static int ext4_warning_ratelimit(struct super_block *sb)
944 {
945 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
946 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
947 			    "EXT4-fs warning");
948 }
949 
950 void __ext4_warning(struct super_block *sb, const char *function,
951 		    unsigned int line, const char *fmt, ...)
952 {
953 	struct va_format vaf;
954 	va_list args;
955 
956 	if (!ext4_warning_ratelimit(sb))
957 		return;
958 
959 	va_start(args, fmt);
960 	vaf.fmt = fmt;
961 	vaf.va = &args;
962 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
963 	       sb->s_id, function, line, &vaf);
964 	va_end(args);
965 }
966 
967 void __ext4_warning_inode(const struct inode *inode, const char *function,
968 			  unsigned int line, const char *fmt, ...)
969 {
970 	struct va_format vaf;
971 	va_list args;
972 
973 	if (!ext4_warning_ratelimit(inode->i_sb))
974 		return;
975 
976 	va_start(args, fmt);
977 	vaf.fmt = fmt;
978 	vaf.va = &args;
979 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
980 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
981 	       function, line, inode->i_ino, current->comm, &vaf);
982 	va_end(args);
983 }
984 
985 void __ext4_grp_locked_error(const char *function, unsigned int line,
986 			     struct super_block *sb, ext4_group_t grp,
987 			     unsigned long ino, ext4_fsblk_t block,
988 			     const char *fmt, ...)
989 __releases(bitlock)
990 __acquires(bitlock)
991 {
992 	struct va_format vaf;
993 	va_list args;
994 
995 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
996 		return;
997 
998 	trace_ext4_error(sb, function, line);
999 	if (ext4_error_ratelimit(sb)) {
1000 		va_start(args, fmt);
1001 		vaf.fmt = fmt;
1002 		vaf.va = &args;
1003 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1004 		       sb->s_id, function, line, grp);
1005 		if (ino)
1006 			printk(KERN_CONT "inode %lu: ", ino);
1007 		if (block)
1008 			printk(KERN_CONT "block %llu:",
1009 			       (unsigned long long) block);
1010 		printk(KERN_CONT "%pV\n", &vaf);
1011 		va_end(args);
1012 	}
1013 
1014 	if (test_opt(sb, ERRORS_CONT)) {
1015 		if (test_opt(sb, WARN_ON_ERROR))
1016 			WARN_ON_ONCE(1);
1017 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1018 		if (!bdev_read_only(sb->s_bdev)) {
1019 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1020 					line);
1021 			schedule_work(&EXT4_SB(sb)->s_error_work);
1022 		}
1023 		return;
1024 	}
1025 	ext4_unlock_group(sb, grp);
1026 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1027 	/*
1028 	 * We only get here in the ERRORS_RO case; relocking the group
1029 	 * may be dangerous, but nothing bad will happen since the
1030 	 * filesystem will have already been marked read/only and the
1031 	 * journal has been aborted.  We return 1 as a hint to callers
1032 	 * who might what to use the return value from
1033 	 * ext4_grp_locked_error() to distinguish between the
1034 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1035 	 * aggressively from the ext4 function in question, with a
1036 	 * more appropriate error code.
1037 	 */
1038 	ext4_lock_group(sb, grp);
1039 	return;
1040 }
1041 
1042 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1043 				     ext4_group_t group,
1044 				     unsigned int flags)
1045 {
1046 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1047 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1048 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1049 	int ret;
1050 
1051 	if (!grp || !gdp)
1052 		return;
1053 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1054 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1055 					    &grp->bb_state);
1056 		if (!ret)
1057 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1058 					   grp->bb_free);
1059 	}
1060 
1061 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1062 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1063 					    &grp->bb_state);
1064 		if (!ret && gdp) {
1065 			int count;
1066 
1067 			count = ext4_free_inodes_count(sb, gdp);
1068 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1069 					   count);
1070 		}
1071 	}
1072 }
1073 
1074 void ext4_update_dynamic_rev(struct super_block *sb)
1075 {
1076 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1077 
1078 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1079 		return;
1080 
1081 	ext4_warning(sb,
1082 		     "updating to rev %d because of new feature flag, "
1083 		     "running e2fsck is recommended",
1084 		     EXT4_DYNAMIC_REV);
1085 
1086 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1087 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1088 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1089 	/* leave es->s_feature_*compat flags alone */
1090 	/* es->s_uuid will be set by e2fsck if empty */
1091 
1092 	/*
1093 	 * The rest of the superblock fields should be zero, and if not it
1094 	 * means they are likely already in use, so leave them alone.  We
1095 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1096 	 */
1097 }
1098 
1099 static void ext4_bdev_mark_dead(struct block_device *bdev)
1100 {
1101 	ext4_force_shutdown(bdev->bd_holder, EXT4_GOING_FLAGS_NOLOGFLUSH);
1102 }
1103 
1104 static const struct blk_holder_ops ext4_holder_ops = {
1105 	.mark_dead		= ext4_bdev_mark_dead,
1106 };
1107 
1108 /*
1109  * Open the external journal device
1110  */
1111 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1112 {
1113 	struct block_device *bdev;
1114 
1115 	bdev = blkdev_get_by_dev(dev, BLK_OPEN_READ | BLK_OPEN_WRITE, sb,
1116 				 &ext4_holder_ops);
1117 	if (IS_ERR(bdev))
1118 		goto fail;
1119 	return bdev;
1120 
1121 fail:
1122 	ext4_msg(sb, KERN_ERR,
1123 		 "failed to open journal device unknown-block(%u,%u) %ld",
1124 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1125 	return NULL;
1126 }
1127 
1128 /*
1129  * Release the journal device
1130  */
1131 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1132 {
1133 	struct block_device *bdev;
1134 	bdev = sbi->s_journal_bdev;
1135 	if (bdev) {
1136 		/*
1137 		 * Invalidate the journal device's buffers.  We don't want them
1138 		 * floating about in memory - the physical journal device may
1139 		 * hotswapped, and it breaks the `ro-after' testing code.
1140 		 */
1141 		invalidate_bdev(bdev);
1142 		blkdev_put(bdev, sbi->s_sb);
1143 		sbi->s_journal_bdev = NULL;
1144 	}
1145 }
1146 
1147 static inline struct inode *orphan_list_entry(struct list_head *l)
1148 {
1149 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1150 }
1151 
1152 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1153 {
1154 	struct list_head *l;
1155 
1156 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1157 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1158 
1159 	printk(KERN_ERR "sb_info orphan list:\n");
1160 	list_for_each(l, &sbi->s_orphan) {
1161 		struct inode *inode = orphan_list_entry(l);
1162 		printk(KERN_ERR "  "
1163 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1164 		       inode->i_sb->s_id, inode->i_ino, inode,
1165 		       inode->i_mode, inode->i_nlink,
1166 		       NEXT_ORPHAN(inode));
1167 	}
1168 }
1169 
1170 #ifdef CONFIG_QUOTA
1171 static int ext4_quota_off(struct super_block *sb, int type);
1172 
1173 static inline void ext4_quotas_off(struct super_block *sb, int type)
1174 {
1175 	BUG_ON(type > EXT4_MAXQUOTAS);
1176 
1177 	/* Use our quota_off function to clear inode flags etc. */
1178 	for (type--; type >= 0; type--)
1179 		ext4_quota_off(sb, type);
1180 }
1181 
1182 /*
1183  * This is a helper function which is used in the mount/remount
1184  * codepaths (which holds s_umount) to fetch the quota file name.
1185  */
1186 static inline char *get_qf_name(struct super_block *sb,
1187 				struct ext4_sb_info *sbi,
1188 				int type)
1189 {
1190 	return rcu_dereference_protected(sbi->s_qf_names[type],
1191 					 lockdep_is_held(&sb->s_umount));
1192 }
1193 #else
1194 static inline void ext4_quotas_off(struct super_block *sb, int type)
1195 {
1196 }
1197 #endif
1198 
1199 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1200 {
1201 	ext4_fsblk_t block;
1202 	int err;
1203 
1204 	block = ext4_count_free_clusters(sbi->s_sb);
1205 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1206 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1207 				  GFP_KERNEL);
1208 	if (!err) {
1209 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1210 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1211 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1212 					  GFP_KERNEL);
1213 	}
1214 	if (!err)
1215 		err = percpu_counter_init(&sbi->s_dirs_counter,
1216 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1217 	if (!err)
1218 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1219 					  GFP_KERNEL);
1220 	if (!err)
1221 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1222 					  GFP_KERNEL);
1223 	if (!err)
1224 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1225 
1226 	if (err)
1227 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1228 
1229 	return err;
1230 }
1231 
1232 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1233 {
1234 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1235 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1236 	percpu_counter_destroy(&sbi->s_dirs_counter);
1237 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1238 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1239 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1240 }
1241 
1242 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1243 {
1244 	struct buffer_head **group_desc;
1245 	int i;
1246 
1247 	rcu_read_lock();
1248 	group_desc = rcu_dereference(sbi->s_group_desc);
1249 	for (i = 0; i < sbi->s_gdb_count; i++)
1250 		brelse(group_desc[i]);
1251 	kvfree(group_desc);
1252 	rcu_read_unlock();
1253 }
1254 
1255 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1256 {
1257 	struct flex_groups **flex_groups;
1258 	int i;
1259 
1260 	rcu_read_lock();
1261 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1262 	if (flex_groups) {
1263 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1264 			kvfree(flex_groups[i]);
1265 		kvfree(flex_groups);
1266 	}
1267 	rcu_read_unlock();
1268 }
1269 
1270 static void ext4_put_super(struct super_block *sb)
1271 {
1272 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1273 	struct ext4_super_block *es = sbi->s_es;
1274 	int aborted = 0;
1275 	int err;
1276 
1277 	/*
1278 	 * Unregister sysfs before destroying jbd2 journal.
1279 	 * Since we could still access attr_journal_task attribute via sysfs
1280 	 * path which could have sbi->s_journal->j_task as NULL
1281 	 * Unregister sysfs before flush sbi->s_error_work.
1282 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1283 	 * read metadata verify failed then will queue error work.
1284 	 * flush_stashed_error_work will call start_this_handle may trigger
1285 	 * BUG_ON.
1286 	 */
1287 	ext4_unregister_sysfs(sb);
1288 
1289 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1290 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1291 			 &sb->s_uuid);
1292 
1293 	ext4_unregister_li_request(sb);
1294 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1295 
1296 	flush_work(&sbi->s_error_work);
1297 	destroy_workqueue(sbi->rsv_conversion_wq);
1298 	ext4_release_orphan_info(sb);
1299 
1300 	if (sbi->s_journal) {
1301 		aborted = is_journal_aborted(sbi->s_journal);
1302 		err = jbd2_journal_destroy(sbi->s_journal);
1303 		sbi->s_journal = NULL;
1304 		if ((err < 0) && !aborted) {
1305 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1306 		}
1307 	}
1308 
1309 	ext4_es_unregister_shrinker(sbi);
1310 	timer_shutdown_sync(&sbi->s_err_report);
1311 	ext4_release_system_zone(sb);
1312 	ext4_mb_release(sb);
1313 	ext4_ext_release(sb);
1314 
1315 	if (!sb_rdonly(sb) && !aborted) {
1316 		ext4_clear_feature_journal_needs_recovery(sb);
1317 		ext4_clear_feature_orphan_present(sb);
1318 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1319 	}
1320 	if (!sb_rdonly(sb))
1321 		ext4_commit_super(sb);
1322 
1323 	ext4_group_desc_free(sbi);
1324 	ext4_flex_groups_free(sbi);
1325 	ext4_percpu_param_destroy(sbi);
1326 #ifdef CONFIG_QUOTA
1327 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1328 		kfree(get_qf_name(sb, sbi, i));
1329 #endif
1330 
1331 	/* Debugging code just in case the in-memory inode orphan list
1332 	 * isn't empty.  The on-disk one can be non-empty if we've
1333 	 * detected an error and taken the fs readonly, but the
1334 	 * in-memory list had better be clean by this point. */
1335 	if (!list_empty(&sbi->s_orphan))
1336 		dump_orphan_list(sb, sbi);
1337 	ASSERT(list_empty(&sbi->s_orphan));
1338 
1339 	sync_blockdev(sb->s_bdev);
1340 	invalidate_bdev(sb->s_bdev);
1341 	if (sbi->s_journal_bdev) {
1342 		sync_blockdev(sbi->s_journal_bdev);
1343 		ext4_blkdev_remove(sbi);
1344 	}
1345 
1346 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1347 	sbi->s_ea_inode_cache = NULL;
1348 
1349 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1350 	sbi->s_ea_block_cache = NULL;
1351 
1352 	ext4_stop_mmpd(sbi);
1353 
1354 	brelse(sbi->s_sbh);
1355 	sb->s_fs_info = NULL;
1356 	/*
1357 	 * Now that we are completely done shutting down the
1358 	 * superblock, we need to actually destroy the kobject.
1359 	 */
1360 	kobject_put(&sbi->s_kobj);
1361 	wait_for_completion(&sbi->s_kobj_unregister);
1362 	if (sbi->s_chksum_driver)
1363 		crypto_free_shash(sbi->s_chksum_driver);
1364 	kfree(sbi->s_blockgroup_lock);
1365 	fs_put_dax(sbi->s_daxdev, NULL);
1366 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1367 #if IS_ENABLED(CONFIG_UNICODE)
1368 	utf8_unload(sb->s_encoding);
1369 #endif
1370 	kfree(sbi);
1371 }
1372 
1373 static struct kmem_cache *ext4_inode_cachep;
1374 
1375 /*
1376  * Called inside transaction, so use GFP_NOFS
1377  */
1378 static struct inode *ext4_alloc_inode(struct super_block *sb)
1379 {
1380 	struct ext4_inode_info *ei;
1381 
1382 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1383 	if (!ei)
1384 		return NULL;
1385 
1386 	inode_set_iversion(&ei->vfs_inode, 1);
1387 	ei->i_flags = 0;
1388 	spin_lock_init(&ei->i_raw_lock);
1389 	ei->i_prealloc_node = RB_ROOT;
1390 	atomic_set(&ei->i_prealloc_active, 0);
1391 	rwlock_init(&ei->i_prealloc_lock);
1392 	ext4_es_init_tree(&ei->i_es_tree);
1393 	rwlock_init(&ei->i_es_lock);
1394 	INIT_LIST_HEAD(&ei->i_es_list);
1395 	ei->i_es_all_nr = 0;
1396 	ei->i_es_shk_nr = 0;
1397 	ei->i_es_shrink_lblk = 0;
1398 	ei->i_reserved_data_blocks = 0;
1399 	spin_lock_init(&(ei->i_block_reservation_lock));
1400 	ext4_init_pending_tree(&ei->i_pending_tree);
1401 #ifdef CONFIG_QUOTA
1402 	ei->i_reserved_quota = 0;
1403 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1404 #endif
1405 	ei->jinode = NULL;
1406 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1407 	spin_lock_init(&ei->i_completed_io_lock);
1408 	ei->i_sync_tid = 0;
1409 	ei->i_datasync_tid = 0;
1410 	atomic_set(&ei->i_unwritten, 0);
1411 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1412 	ext4_fc_init_inode(&ei->vfs_inode);
1413 	mutex_init(&ei->i_fc_lock);
1414 	return &ei->vfs_inode;
1415 }
1416 
1417 static int ext4_drop_inode(struct inode *inode)
1418 {
1419 	int drop = generic_drop_inode(inode);
1420 
1421 	if (!drop)
1422 		drop = fscrypt_drop_inode(inode);
1423 
1424 	trace_ext4_drop_inode(inode, drop);
1425 	return drop;
1426 }
1427 
1428 static void ext4_free_in_core_inode(struct inode *inode)
1429 {
1430 	fscrypt_free_inode(inode);
1431 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1432 		pr_warn("%s: inode %ld still in fc list",
1433 			__func__, inode->i_ino);
1434 	}
1435 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1436 }
1437 
1438 static void ext4_destroy_inode(struct inode *inode)
1439 {
1440 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1441 		ext4_msg(inode->i_sb, KERN_ERR,
1442 			 "Inode %lu (%p): orphan list check failed!",
1443 			 inode->i_ino, EXT4_I(inode));
1444 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1445 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1446 				true);
1447 		dump_stack();
1448 	}
1449 
1450 	if (EXT4_I(inode)->i_reserved_data_blocks)
1451 		ext4_msg(inode->i_sb, KERN_ERR,
1452 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1453 			 inode->i_ino, EXT4_I(inode),
1454 			 EXT4_I(inode)->i_reserved_data_blocks);
1455 }
1456 
1457 static void ext4_shutdown(struct super_block *sb)
1458 {
1459        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1460 }
1461 
1462 static void init_once(void *foo)
1463 {
1464 	struct ext4_inode_info *ei = foo;
1465 
1466 	INIT_LIST_HEAD(&ei->i_orphan);
1467 	init_rwsem(&ei->xattr_sem);
1468 	init_rwsem(&ei->i_data_sem);
1469 	inode_init_once(&ei->vfs_inode);
1470 	ext4_fc_init_inode(&ei->vfs_inode);
1471 }
1472 
1473 static int __init init_inodecache(void)
1474 {
1475 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1476 				sizeof(struct ext4_inode_info), 0,
1477 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1478 					SLAB_ACCOUNT),
1479 				offsetof(struct ext4_inode_info, i_data),
1480 				sizeof_field(struct ext4_inode_info, i_data),
1481 				init_once);
1482 	if (ext4_inode_cachep == NULL)
1483 		return -ENOMEM;
1484 	return 0;
1485 }
1486 
1487 static void destroy_inodecache(void)
1488 {
1489 	/*
1490 	 * Make sure all delayed rcu free inodes are flushed before we
1491 	 * destroy cache.
1492 	 */
1493 	rcu_barrier();
1494 	kmem_cache_destroy(ext4_inode_cachep);
1495 }
1496 
1497 void ext4_clear_inode(struct inode *inode)
1498 {
1499 	ext4_fc_del(inode);
1500 	invalidate_inode_buffers(inode);
1501 	clear_inode(inode);
1502 	ext4_discard_preallocations(inode, 0);
1503 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1504 	dquot_drop(inode);
1505 	if (EXT4_I(inode)->jinode) {
1506 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1507 					       EXT4_I(inode)->jinode);
1508 		jbd2_free_inode(EXT4_I(inode)->jinode);
1509 		EXT4_I(inode)->jinode = NULL;
1510 	}
1511 	fscrypt_put_encryption_info(inode);
1512 	fsverity_cleanup_inode(inode);
1513 }
1514 
1515 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1516 					u64 ino, u32 generation)
1517 {
1518 	struct inode *inode;
1519 
1520 	/*
1521 	 * Currently we don't know the generation for parent directory, so
1522 	 * a generation of 0 means "accept any"
1523 	 */
1524 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1525 	if (IS_ERR(inode))
1526 		return ERR_CAST(inode);
1527 	if (generation && inode->i_generation != generation) {
1528 		iput(inode);
1529 		return ERR_PTR(-ESTALE);
1530 	}
1531 
1532 	return inode;
1533 }
1534 
1535 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1536 					int fh_len, int fh_type)
1537 {
1538 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1539 				    ext4_nfs_get_inode);
1540 }
1541 
1542 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1543 					int fh_len, int fh_type)
1544 {
1545 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1546 				    ext4_nfs_get_inode);
1547 }
1548 
1549 static int ext4_nfs_commit_metadata(struct inode *inode)
1550 {
1551 	struct writeback_control wbc = {
1552 		.sync_mode = WB_SYNC_ALL
1553 	};
1554 
1555 	trace_ext4_nfs_commit_metadata(inode);
1556 	return ext4_write_inode(inode, &wbc);
1557 }
1558 
1559 #ifdef CONFIG_QUOTA
1560 static const char * const quotatypes[] = INITQFNAMES;
1561 #define QTYPE2NAME(t) (quotatypes[t])
1562 
1563 static int ext4_write_dquot(struct dquot *dquot);
1564 static int ext4_acquire_dquot(struct dquot *dquot);
1565 static int ext4_release_dquot(struct dquot *dquot);
1566 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1567 static int ext4_write_info(struct super_block *sb, int type);
1568 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1569 			 const struct path *path);
1570 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1571 			       size_t len, loff_t off);
1572 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1573 				const char *data, size_t len, loff_t off);
1574 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1575 			     unsigned int flags);
1576 
1577 static struct dquot **ext4_get_dquots(struct inode *inode)
1578 {
1579 	return EXT4_I(inode)->i_dquot;
1580 }
1581 
1582 static const struct dquot_operations ext4_quota_operations = {
1583 	.get_reserved_space	= ext4_get_reserved_space,
1584 	.write_dquot		= ext4_write_dquot,
1585 	.acquire_dquot		= ext4_acquire_dquot,
1586 	.release_dquot		= ext4_release_dquot,
1587 	.mark_dirty		= ext4_mark_dquot_dirty,
1588 	.write_info		= ext4_write_info,
1589 	.alloc_dquot		= dquot_alloc,
1590 	.destroy_dquot		= dquot_destroy,
1591 	.get_projid		= ext4_get_projid,
1592 	.get_inode_usage	= ext4_get_inode_usage,
1593 	.get_next_id		= dquot_get_next_id,
1594 };
1595 
1596 static const struct quotactl_ops ext4_qctl_operations = {
1597 	.quota_on	= ext4_quota_on,
1598 	.quota_off	= ext4_quota_off,
1599 	.quota_sync	= dquot_quota_sync,
1600 	.get_state	= dquot_get_state,
1601 	.set_info	= dquot_set_dqinfo,
1602 	.get_dqblk	= dquot_get_dqblk,
1603 	.set_dqblk	= dquot_set_dqblk,
1604 	.get_nextdqblk	= dquot_get_next_dqblk,
1605 };
1606 #endif
1607 
1608 static const struct super_operations ext4_sops = {
1609 	.alloc_inode	= ext4_alloc_inode,
1610 	.free_inode	= ext4_free_in_core_inode,
1611 	.destroy_inode	= ext4_destroy_inode,
1612 	.write_inode	= ext4_write_inode,
1613 	.dirty_inode	= ext4_dirty_inode,
1614 	.drop_inode	= ext4_drop_inode,
1615 	.evict_inode	= ext4_evict_inode,
1616 	.put_super	= ext4_put_super,
1617 	.sync_fs	= ext4_sync_fs,
1618 	.freeze_fs	= ext4_freeze,
1619 	.unfreeze_fs	= ext4_unfreeze,
1620 	.statfs		= ext4_statfs,
1621 	.show_options	= ext4_show_options,
1622 	.shutdown	= ext4_shutdown,
1623 #ifdef CONFIG_QUOTA
1624 	.quota_read	= ext4_quota_read,
1625 	.quota_write	= ext4_quota_write,
1626 	.get_dquots	= ext4_get_dquots,
1627 #endif
1628 };
1629 
1630 static const struct export_operations ext4_export_ops = {
1631 	.fh_to_dentry = ext4_fh_to_dentry,
1632 	.fh_to_parent = ext4_fh_to_parent,
1633 	.get_parent = ext4_get_parent,
1634 	.commit_metadata = ext4_nfs_commit_metadata,
1635 };
1636 
1637 enum {
1638 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1639 	Opt_resgid, Opt_resuid, Opt_sb,
1640 	Opt_nouid32, Opt_debug, Opt_removed,
1641 	Opt_user_xattr, Opt_acl,
1642 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1643 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1644 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1645 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1646 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1647 	Opt_inlinecrypt,
1648 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1649 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1650 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1651 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1652 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1653 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1654 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1655 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1656 	Opt_dioread_nolock, Opt_dioread_lock,
1657 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1658 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1659 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1660 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1661 #ifdef CONFIG_EXT4_DEBUG
1662 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1663 #endif
1664 };
1665 
1666 static const struct constant_table ext4_param_errors[] = {
1667 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1668 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1669 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1670 	{}
1671 };
1672 
1673 static const struct constant_table ext4_param_data[] = {
1674 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1675 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1676 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1677 	{}
1678 };
1679 
1680 static const struct constant_table ext4_param_data_err[] = {
1681 	{"abort",	Opt_data_err_abort},
1682 	{"ignore",	Opt_data_err_ignore},
1683 	{}
1684 };
1685 
1686 static const struct constant_table ext4_param_jqfmt[] = {
1687 	{"vfsold",	QFMT_VFS_OLD},
1688 	{"vfsv0",	QFMT_VFS_V0},
1689 	{"vfsv1",	QFMT_VFS_V1},
1690 	{}
1691 };
1692 
1693 static const struct constant_table ext4_param_dax[] = {
1694 	{"always",	Opt_dax_always},
1695 	{"inode",	Opt_dax_inode},
1696 	{"never",	Opt_dax_never},
1697 	{}
1698 };
1699 
1700 /* String parameter that allows empty argument */
1701 #define fsparam_string_empty(NAME, OPT) \
1702 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1703 
1704 /*
1705  * Mount option specification
1706  * We don't use fsparam_flag_no because of the way we set the
1707  * options and the way we show them in _ext4_show_options(). To
1708  * keep the changes to a minimum, let's keep the negative options
1709  * separate for now.
1710  */
1711 static const struct fs_parameter_spec ext4_param_specs[] = {
1712 	fsparam_flag	("bsddf",		Opt_bsd_df),
1713 	fsparam_flag	("minixdf",		Opt_minix_df),
1714 	fsparam_flag	("grpid",		Opt_grpid),
1715 	fsparam_flag	("bsdgroups",		Opt_grpid),
1716 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1717 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1718 	fsparam_u32	("resgid",		Opt_resgid),
1719 	fsparam_u32	("resuid",		Opt_resuid),
1720 	fsparam_u32	("sb",			Opt_sb),
1721 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1722 	fsparam_flag	("nouid32",		Opt_nouid32),
1723 	fsparam_flag	("debug",		Opt_debug),
1724 	fsparam_flag	("oldalloc",		Opt_removed),
1725 	fsparam_flag	("orlov",		Opt_removed),
1726 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1727 	fsparam_flag	("acl",			Opt_acl),
1728 	fsparam_flag	("norecovery",		Opt_noload),
1729 	fsparam_flag	("noload",		Opt_noload),
1730 	fsparam_flag	("bh",			Opt_removed),
1731 	fsparam_flag	("nobh",		Opt_removed),
1732 	fsparam_u32	("commit",		Opt_commit),
1733 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1734 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1735 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1736 	fsparam_bdev	("journal_path",	Opt_journal_path),
1737 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1738 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1739 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1740 	fsparam_flag	("abort",		Opt_abort),
1741 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1742 	fsparam_enum	("data_err",		Opt_data_err,
1743 						ext4_param_data_err),
1744 	fsparam_string_empty
1745 			("usrjquota",		Opt_usrjquota),
1746 	fsparam_string_empty
1747 			("grpjquota",		Opt_grpjquota),
1748 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1749 	fsparam_flag	("grpquota",		Opt_grpquota),
1750 	fsparam_flag	("quota",		Opt_quota),
1751 	fsparam_flag	("noquota",		Opt_noquota),
1752 	fsparam_flag	("usrquota",		Opt_usrquota),
1753 	fsparam_flag	("prjquota",		Opt_prjquota),
1754 	fsparam_flag	("barrier",		Opt_barrier),
1755 	fsparam_u32	("barrier",		Opt_barrier),
1756 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1757 	fsparam_flag	("i_version",		Opt_removed),
1758 	fsparam_flag	("dax",			Opt_dax),
1759 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1760 	fsparam_u32	("stripe",		Opt_stripe),
1761 	fsparam_flag	("delalloc",		Opt_delalloc),
1762 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1763 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1764 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1765 	fsparam_u32	("debug_want_extra_isize",
1766 						Opt_debug_want_extra_isize),
1767 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1768 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1769 	fsparam_flag	("block_validity",	Opt_block_validity),
1770 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1771 	fsparam_u32	("inode_readahead_blks",
1772 						Opt_inode_readahead_blks),
1773 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1774 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1775 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1776 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1777 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1778 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1779 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1780 	fsparam_flag	("discard",		Opt_discard),
1781 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1782 	fsparam_u32	("init_itable",		Opt_init_itable),
1783 	fsparam_flag	("init_itable",		Opt_init_itable),
1784 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1785 #ifdef CONFIG_EXT4_DEBUG
1786 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1787 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1788 #endif
1789 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1790 	fsparam_flag	("test_dummy_encryption",
1791 						Opt_test_dummy_encryption),
1792 	fsparam_string	("test_dummy_encryption",
1793 						Opt_test_dummy_encryption),
1794 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1795 	fsparam_flag	("nombcache",		Opt_nombcache),
1796 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1797 	fsparam_flag	("prefetch_block_bitmaps",
1798 						Opt_removed),
1799 	fsparam_flag	("no_prefetch_block_bitmaps",
1800 						Opt_no_prefetch_block_bitmaps),
1801 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1802 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1803 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1804 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1805 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1806 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1807 	{}
1808 };
1809 
1810 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1811 
1812 #define MOPT_SET	0x0001
1813 #define MOPT_CLEAR	0x0002
1814 #define MOPT_NOSUPPORT	0x0004
1815 #define MOPT_EXPLICIT	0x0008
1816 #ifdef CONFIG_QUOTA
1817 #define MOPT_Q		0
1818 #define MOPT_QFMT	0x0010
1819 #else
1820 #define MOPT_Q		MOPT_NOSUPPORT
1821 #define MOPT_QFMT	MOPT_NOSUPPORT
1822 #endif
1823 #define MOPT_NO_EXT2	0x0020
1824 #define MOPT_NO_EXT3	0x0040
1825 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1826 #define MOPT_SKIP	0x0080
1827 #define	MOPT_2		0x0100
1828 
1829 static const struct mount_opts {
1830 	int	token;
1831 	int	mount_opt;
1832 	int	flags;
1833 } ext4_mount_opts[] = {
1834 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1835 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1836 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1837 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1838 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1839 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1840 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1841 	 MOPT_EXT4_ONLY | MOPT_SET},
1842 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1843 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1844 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1845 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1846 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1847 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1848 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1849 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1850 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1851 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1852 	{Opt_commit, 0, MOPT_NO_EXT2},
1853 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1854 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1855 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1856 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1857 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1858 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1859 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1860 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1861 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1862 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1863 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1864 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1865 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1866 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1867 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1868 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1869 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1870 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1871 	{Opt_data, 0, MOPT_NO_EXT2},
1872 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1873 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1874 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1875 #else
1876 	{Opt_acl, 0, MOPT_NOSUPPORT},
1877 #endif
1878 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1879 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1880 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1881 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1882 							MOPT_SET | MOPT_Q},
1883 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1884 							MOPT_SET | MOPT_Q},
1885 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1886 							MOPT_SET | MOPT_Q},
1887 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1888 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1889 							MOPT_CLEAR | MOPT_Q},
1890 	{Opt_usrjquota, 0, MOPT_Q},
1891 	{Opt_grpjquota, 0, MOPT_Q},
1892 	{Opt_jqfmt, 0, MOPT_QFMT},
1893 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1894 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1895 	 MOPT_SET},
1896 #ifdef CONFIG_EXT4_DEBUG
1897 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1898 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1899 #endif
1900 	{Opt_err, 0, 0}
1901 };
1902 
1903 #if IS_ENABLED(CONFIG_UNICODE)
1904 static const struct ext4_sb_encodings {
1905 	__u16 magic;
1906 	char *name;
1907 	unsigned int version;
1908 } ext4_sb_encoding_map[] = {
1909 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1910 };
1911 
1912 static const struct ext4_sb_encodings *
1913 ext4_sb_read_encoding(const struct ext4_super_block *es)
1914 {
1915 	__u16 magic = le16_to_cpu(es->s_encoding);
1916 	int i;
1917 
1918 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1919 		if (magic == ext4_sb_encoding_map[i].magic)
1920 			return &ext4_sb_encoding_map[i];
1921 
1922 	return NULL;
1923 }
1924 #endif
1925 
1926 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1927 #define EXT4_SPEC_JQFMT				(1 <<  1)
1928 #define EXT4_SPEC_DATAJ				(1 <<  2)
1929 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1930 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1931 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1932 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1933 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1934 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1935 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1936 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1937 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1938 #define EXT4_SPEC_s_stripe			(1 << 13)
1939 #define EXT4_SPEC_s_resuid			(1 << 14)
1940 #define EXT4_SPEC_s_resgid			(1 << 15)
1941 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1942 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1943 #define EXT4_SPEC_s_sb_block			(1 << 18)
1944 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1945 
1946 struct ext4_fs_context {
1947 	char		*s_qf_names[EXT4_MAXQUOTAS];
1948 	struct fscrypt_dummy_policy dummy_enc_policy;
1949 	int		s_jquota_fmt;	/* Format of quota to use */
1950 #ifdef CONFIG_EXT4_DEBUG
1951 	int s_fc_debug_max_replay;
1952 #endif
1953 	unsigned short	qname_spec;
1954 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1955 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1956 	unsigned long	journal_devnum;
1957 	unsigned long	s_commit_interval;
1958 	unsigned long	s_stripe;
1959 	unsigned int	s_inode_readahead_blks;
1960 	unsigned int	s_want_extra_isize;
1961 	unsigned int	s_li_wait_mult;
1962 	unsigned int	s_max_dir_size_kb;
1963 	unsigned int	journal_ioprio;
1964 	unsigned int	vals_s_mount_opt;
1965 	unsigned int	mask_s_mount_opt;
1966 	unsigned int	vals_s_mount_opt2;
1967 	unsigned int	mask_s_mount_opt2;
1968 	unsigned long	vals_s_mount_flags;
1969 	unsigned long	mask_s_mount_flags;
1970 	unsigned int	opt_flags;	/* MOPT flags */
1971 	unsigned int	spec;
1972 	u32		s_max_batch_time;
1973 	u32		s_min_batch_time;
1974 	kuid_t		s_resuid;
1975 	kgid_t		s_resgid;
1976 	ext4_fsblk_t	s_sb_block;
1977 };
1978 
1979 static void ext4_fc_free(struct fs_context *fc)
1980 {
1981 	struct ext4_fs_context *ctx = fc->fs_private;
1982 	int i;
1983 
1984 	if (!ctx)
1985 		return;
1986 
1987 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1988 		kfree(ctx->s_qf_names[i]);
1989 
1990 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1991 	kfree(ctx);
1992 }
1993 
1994 int ext4_init_fs_context(struct fs_context *fc)
1995 {
1996 	struct ext4_fs_context *ctx;
1997 
1998 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1999 	if (!ctx)
2000 		return -ENOMEM;
2001 
2002 	fc->fs_private = ctx;
2003 	fc->ops = &ext4_context_ops;
2004 
2005 	return 0;
2006 }
2007 
2008 #ifdef CONFIG_QUOTA
2009 /*
2010  * Note the name of the specified quota file.
2011  */
2012 static int note_qf_name(struct fs_context *fc, int qtype,
2013 		       struct fs_parameter *param)
2014 {
2015 	struct ext4_fs_context *ctx = fc->fs_private;
2016 	char *qname;
2017 
2018 	if (param->size < 1) {
2019 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2020 		return -EINVAL;
2021 	}
2022 	if (strchr(param->string, '/')) {
2023 		ext4_msg(NULL, KERN_ERR,
2024 			 "quotafile must be on filesystem root");
2025 		return -EINVAL;
2026 	}
2027 	if (ctx->s_qf_names[qtype]) {
2028 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2029 			ext4_msg(NULL, KERN_ERR,
2030 				 "%s quota file already specified",
2031 				 QTYPE2NAME(qtype));
2032 			return -EINVAL;
2033 		}
2034 		return 0;
2035 	}
2036 
2037 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2038 	if (!qname) {
2039 		ext4_msg(NULL, KERN_ERR,
2040 			 "Not enough memory for storing quotafile name");
2041 		return -ENOMEM;
2042 	}
2043 	ctx->s_qf_names[qtype] = qname;
2044 	ctx->qname_spec |= 1 << qtype;
2045 	ctx->spec |= EXT4_SPEC_JQUOTA;
2046 	return 0;
2047 }
2048 
2049 /*
2050  * Clear the name of the specified quota file.
2051  */
2052 static int unnote_qf_name(struct fs_context *fc, int qtype)
2053 {
2054 	struct ext4_fs_context *ctx = fc->fs_private;
2055 
2056 	if (ctx->s_qf_names[qtype])
2057 		kfree(ctx->s_qf_names[qtype]);
2058 
2059 	ctx->s_qf_names[qtype] = NULL;
2060 	ctx->qname_spec |= 1 << qtype;
2061 	ctx->spec |= EXT4_SPEC_JQUOTA;
2062 	return 0;
2063 }
2064 #endif
2065 
2066 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2067 					    struct ext4_fs_context *ctx)
2068 {
2069 	int err;
2070 
2071 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2072 		ext4_msg(NULL, KERN_WARNING,
2073 			 "test_dummy_encryption option not supported");
2074 		return -EINVAL;
2075 	}
2076 	err = fscrypt_parse_test_dummy_encryption(param,
2077 						  &ctx->dummy_enc_policy);
2078 	if (err == -EINVAL) {
2079 		ext4_msg(NULL, KERN_WARNING,
2080 			 "Value of option \"%s\" is unrecognized", param->key);
2081 	} else if (err == -EEXIST) {
2082 		ext4_msg(NULL, KERN_WARNING,
2083 			 "Conflicting test_dummy_encryption options");
2084 		return -EINVAL;
2085 	}
2086 	return err;
2087 }
2088 
2089 #define EXT4_SET_CTX(name)						\
2090 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2091 				  unsigned long flag)			\
2092 {									\
2093 	ctx->mask_s_##name |= flag;					\
2094 	ctx->vals_s_##name |= flag;					\
2095 }
2096 
2097 #define EXT4_CLEAR_CTX(name)						\
2098 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2099 				    unsigned long flag)			\
2100 {									\
2101 	ctx->mask_s_##name |= flag;					\
2102 	ctx->vals_s_##name &= ~flag;					\
2103 }
2104 
2105 #define EXT4_TEST_CTX(name)						\
2106 static inline unsigned long						\
2107 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2108 {									\
2109 	return (ctx->vals_s_##name & flag);				\
2110 }
2111 
2112 EXT4_SET_CTX(flags); /* set only */
2113 EXT4_SET_CTX(mount_opt);
2114 EXT4_CLEAR_CTX(mount_opt);
2115 EXT4_TEST_CTX(mount_opt);
2116 EXT4_SET_CTX(mount_opt2);
2117 EXT4_CLEAR_CTX(mount_opt2);
2118 EXT4_TEST_CTX(mount_opt2);
2119 
2120 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2121 {
2122 	set_bit(bit, &ctx->mask_s_mount_flags);
2123 	set_bit(bit, &ctx->vals_s_mount_flags);
2124 }
2125 
2126 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2127 {
2128 	struct ext4_fs_context *ctx = fc->fs_private;
2129 	struct fs_parse_result result;
2130 	const struct mount_opts *m;
2131 	int is_remount;
2132 	kuid_t uid;
2133 	kgid_t gid;
2134 	int token;
2135 
2136 	token = fs_parse(fc, ext4_param_specs, param, &result);
2137 	if (token < 0)
2138 		return token;
2139 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2140 
2141 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2142 		if (token == m->token)
2143 			break;
2144 
2145 	ctx->opt_flags |= m->flags;
2146 
2147 	if (m->flags & MOPT_EXPLICIT) {
2148 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2149 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2150 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2151 			ctx_set_mount_opt2(ctx,
2152 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2153 		} else
2154 			return -EINVAL;
2155 	}
2156 
2157 	if (m->flags & MOPT_NOSUPPORT) {
2158 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2159 			 param->key);
2160 		return 0;
2161 	}
2162 
2163 	switch (token) {
2164 #ifdef CONFIG_QUOTA
2165 	case Opt_usrjquota:
2166 		if (!*param->string)
2167 			return unnote_qf_name(fc, USRQUOTA);
2168 		else
2169 			return note_qf_name(fc, USRQUOTA, param);
2170 	case Opt_grpjquota:
2171 		if (!*param->string)
2172 			return unnote_qf_name(fc, GRPQUOTA);
2173 		else
2174 			return note_qf_name(fc, GRPQUOTA, param);
2175 #endif
2176 	case Opt_sb:
2177 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2178 			ext4_msg(NULL, KERN_WARNING,
2179 				 "Ignoring %s option on remount", param->key);
2180 		} else {
2181 			ctx->s_sb_block = result.uint_32;
2182 			ctx->spec |= EXT4_SPEC_s_sb_block;
2183 		}
2184 		return 0;
2185 	case Opt_removed:
2186 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2187 			 param->key);
2188 		return 0;
2189 	case Opt_abort:
2190 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2191 		return 0;
2192 	case Opt_inlinecrypt:
2193 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2194 		ctx_set_flags(ctx, SB_INLINECRYPT);
2195 #else
2196 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2197 #endif
2198 		return 0;
2199 	case Opt_errors:
2200 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2201 		ctx_set_mount_opt(ctx, result.uint_32);
2202 		return 0;
2203 #ifdef CONFIG_QUOTA
2204 	case Opt_jqfmt:
2205 		ctx->s_jquota_fmt = result.uint_32;
2206 		ctx->spec |= EXT4_SPEC_JQFMT;
2207 		return 0;
2208 #endif
2209 	case Opt_data:
2210 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2211 		ctx_set_mount_opt(ctx, result.uint_32);
2212 		ctx->spec |= EXT4_SPEC_DATAJ;
2213 		return 0;
2214 	case Opt_commit:
2215 		if (result.uint_32 == 0)
2216 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2217 		else if (result.uint_32 > INT_MAX / HZ) {
2218 			ext4_msg(NULL, KERN_ERR,
2219 				 "Invalid commit interval %d, "
2220 				 "must be smaller than %d",
2221 				 result.uint_32, INT_MAX / HZ);
2222 			return -EINVAL;
2223 		}
2224 		ctx->s_commit_interval = HZ * result.uint_32;
2225 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2226 		return 0;
2227 	case Opt_debug_want_extra_isize:
2228 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2229 			ext4_msg(NULL, KERN_ERR,
2230 				 "Invalid want_extra_isize %d", result.uint_32);
2231 			return -EINVAL;
2232 		}
2233 		ctx->s_want_extra_isize = result.uint_32;
2234 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2235 		return 0;
2236 	case Opt_max_batch_time:
2237 		ctx->s_max_batch_time = result.uint_32;
2238 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2239 		return 0;
2240 	case Opt_min_batch_time:
2241 		ctx->s_min_batch_time = result.uint_32;
2242 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2243 		return 0;
2244 	case Opt_inode_readahead_blks:
2245 		if (result.uint_32 &&
2246 		    (result.uint_32 > (1 << 30) ||
2247 		     !is_power_of_2(result.uint_32))) {
2248 			ext4_msg(NULL, KERN_ERR,
2249 				 "EXT4-fs: inode_readahead_blks must be "
2250 				 "0 or a power of 2 smaller than 2^31");
2251 			return -EINVAL;
2252 		}
2253 		ctx->s_inode_readahead_blks = result.uint_32;
2254 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2255 		return 0;
2256 	case Opt_init_itable:
2257 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2258 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2259 		if (param->type == fs_value_is_string)
2260 			ctx->s_li_wait_mult = result.uint_32;
2261 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2262 		return 0;
2263 	case Opt_max_dir_size_kb:
2264 		ctx->s_max_dir_size_kb = result.uint_32;
2265 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2266 		return 0;
2267 #ifdef CONFIG_EXT4_DEBUG
2268 	case Opt_fc_debug_max_replay:
2269 		ctx->s_fc_debug_max_replay = result.uint_32;
2270 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2271 		return 0;
2272 #endif
2273 	case Opt_stripe:
2274 		ctx->s_stripe = result.uint_32;
2275 		ctx->spec |= EXT4_SPEC_s_stripe;
2276 		return 0;
2277 	case Opt_resuid:
2278 		uid = make_kuid(current_user_ns(), result.uint_32);
2279 		if (!uid_valid(uid)) {
2280 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2281 				 result.uint_32);
2282 			return -EINVAL;
2283 		}
2284 		ctx->s_resuid = uid;
2285 		ctx->spec |= EXT4_SPEC_s_resuid;
2286 		return 0;
2287 	case Opt_resgid:
2288 		gid = make_kgid(current_user_ns(), result.uint_32);
2289 		if (!gid_valid(gid)) {
2290 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2291 				 result.uint_32);
2292 			return -EINVAL;
2293 		}
2294 		ctx->s_resgid = gid;
2295 		ctx->spec |= EXT4_SPEC_s_resgid;
2296 		return 0;
2297 	case Opt_journal_dev:
2298 		if (is_remount) {
2299 			ext4_msg(NULL, KERN_ERR,
2300 				 "Cannot specify journal on remount");
2301 			return -EINVAL;
2302 		}
2303 		ctx->journal_devnum = result.uint_32;
2304 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2305 		return 0;
2306 	case Opt_journal_path:
2307 	{
2308 		struct inode *journal_inode;
2309 		struct path path;
2310 		int error;
2311 
2312 		if (is_remount) {
2313 			ext4_msg(NULL, KERN_ERR,
2314 				 "Cannot specify journal on remount");
2315 			return -EINVAL;
2316 		}
2317 
2318 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2319 		if (error) {
2320 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2321 				 "journal device path");
2322 			return -EINVAL;
2323 		}
2324 
2325 		journal_inode = d_inode(path.dentry);
2326 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2327 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2328 		path_put(&path);
2329 		return 0;
2330 	}
2331 	case Opt_journal_ioprio:
2332 		if (result.uint_32 > 7) {
2333 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2334 				 " (must be 0-7)");
2335 			return -EINVAL;
2336 		}
2337 		ctx->journal_ioprio =
2338 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2339 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2340 		return 0;
2341 	case Opt_test_dummy_encryption:
2342 		return ext4_parse_test_dummy_encryption(param, ctx);
2343 	case Opt_dax:
2344 	case Opt_dax_type:
2345 #ifdef CONFIG_FS_DAX
2346 	{
2347 		int type = (token == Opt_dax) ?
2348 			   Opt_dax : result.uint_32;
2349 
2350 		switch (type) {
2351 		case Opt_dax:
2352 		case Opt_dax_always:
2353 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2354 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2355 			break;
2356 		case Opt_dax_never:
2357 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2358 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2359 			break;
2360 		case Opt_dax_inode:
2361 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2362 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2363 			/* Strictly for printing options */
2364 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2365 			break;
2366 		}
2367 		return 0;
2368 	}
2369 #else
2370 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2371 		return -EINVAL;
2372 #endif
2373 	case Opt_data_err:
2374 		if (result.uint_32 == Opt_data_err_abort)
2375 			ctx_set_mount_opt(ctx, m->mount_opt);
2376 		else if (result.uint_32 == Opt_data_err_ignore)
2377 			ctx_clear_mount_opt(ctx, m->mount_opt);
2378 		return 0;
2379 	case Opt_mb_optimize_scan:
2380 		if (result.int_32 == 1) {
2381 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2382 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2383 		} else if (result.int_32 == 0) {
2384 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2385 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2386 		} else {
2387 			ext4_msg(NULL, KERN_WARNING,
2388 				 "mb_optimize_scan should be set to 0 or 1.");
2389 			return -EINVAL;
2390 		}
2391 		return 0;
2392 	}
2393 
2394 	/*
2395 	 * At this point we should only be getting options requiring MOPT_SET,
2396 	 * or MOPT_CLEAR. Anything else is a bug
2397 	 */
2398 	if (m->token == Opt_err) {
2399 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2400 			 param->key);
2401 		WARN_ON(1);
2402 		return -EINVAL;
2403 	}
2404 
2405 	else {
2406 		unsigned int set = 0;
2407 
2408 		if ((param->type == fs_value_is_flag) ||
2409 		    result.uint_32 > 0)
2410 			set = 1;
2411 
2412 		if (m->flags & MOPT_CLEAR)
2413 			set = !set;
2414 		else if (unlikely(!(m->flags & MOPT_SET))) {
2415 			ext4_msg(NULL, KERN_WARNING,
2416 				 "buggy handling of option %s",
2417 				 param->key);
2418 			WARN_ON(1);
2419 			return -EINVAL;
2420 		}
2421 		if (m->flags & MOPT_2) {
2422 			if (set != 0)
2423 				ctx_set_mount_opt2(ctx, m->mount_opt);
2424 			else
2425 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2426 		} else {
2427 			if (set != 0)
2428 				ctx_set_mount_opt(ctx, m->mount_opt);
2429 			else
2430 				ctx_clear_mount_opt(ctx, m->mount_opt);
2431 		}
2432 	}
2433 
2434 	return 0;
2435 }
2436 
2437 static int parse_options(struct fs_context *fc, char *options)
2438 {
2439 	struct fs_parameter param;
2440 	int ret;
2441 	char *key;
2442 
2443 	if (!options)
2444 		return 0;
2445 
2446 	while ((key = strsep(&options, ",")) != NULL) {
2447 		if (*key) {
2448 			size_t v_len = 0;
2449 			char *value = strchr(key, '=');
2450 
2451 			param.type = fs_value_is_flag;
2452 			param.string = NULL;
2453 
2454 			if (value) {
2455 				if (value == key)
2456 					continue;
2457 
2458 				*value++ = 0;
2459 				v_len = strlen(value);
2460 				param.string = kmemdup_nul(value, v_len,
2461 							   GFP_KERNEL);
2462 				if (!param.string)
2463 					return -ENOMEM;
2464 				param.type = fs_value_is_string;
2465 			}
2466 
2467 			param.key = key;
2468 			param.size = v_len;
2469 
2470 			ret = ext4_parse_param(fc, &param);
2471 			if (param.string)
2472 				kfree(param.string);
2473 			if (ret < 0)
2474 				return ret;
2475 		}
2476 	}
2477 
2478 	ret = ext4_validate_options(fc);
2479 	if (ret < 0)
2480 		return ret;
2481 
2482 	return 0;
2483 }
2484 
2485 static int parse_apply_sb_mount_options(struct super_block *sb,
2486 					struct ext4_fs_context *m_ctx)
2487 {
2488 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2489 	char *s_mount_opts = NULL;
2490 	struct ext4_fs_context *s_ctx = NULL;
2491 	struct fs_context *fc = NULL;
2492 	int ret = -ENOMEM;
2493 
2494 	if (!sbi->s_es->s_mount_opts[0])
2495 		return 0;
2496 
2497 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2498 				sizeof(sbi->s_es->s_mount_opts),
2499 				GFP_KERNEL);
2500 	if (!s_mount_opts)
2501 		return ret;
2502 
2503 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2504 	if (!fc)
2505 		goto out_free;
2506 
2507 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2508 	if (!s_ctx)
2509 		goto out_free;
2510 
2511 	fc->fs_private = s_ctx;
2512 	fc->s_fs_info = sbi;
2513 
2514 	ret = parse_options(fc, s_mount_opts);
2515 	if (ret < 0)
2516 		goto parse_failed;
2517 
2518 	ret = ext4_check_opt_consistency(fc, sb);
2519 	if (ret < 0) {
2520 parse_failed:
2521 		ext4_msg(sb, KERN_WARNING,
2522 			 "failed to parse options in superblock: %s",
2523 			 s_mount_opts);
2524 		ret = 0;
2525 		goto out_free;
2526 	}
2527 
2528 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2529 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2530 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2531 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2532 
2533 	ext4_apply_options(fc, sb);
2534 	ret = 0;
2535 
2536 out_free:
2537 	if (fc) {
2538 		ext4_fc_free(fc);
2539 		kfree(fc);
2540 	}
2541 	kfree(s_mount_opts);
2542 	return ret;
2543 }
2544 
2545 static void ext4_apply_quota_options(struct fs_context *fc,
2546 				     struct super_block *sb)
2547 {
2548 #ifdef CONFIG_QUOTA
2549 	bool quota_feature = ext4_has_feature_quota(sb);
2550 	struct ext4_fs_context *ctx = fc->fs_private;
2551 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2552 	char *qname;
2553 	int i;
2554 
2555 	if (quota_feature)
2556 		return;
2557 
2558 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2559 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2560 			if (!(ctx->qname_spec & (1 << i)))
2561 				continue;
2562 
2563 			qname = ctx->s_qf_names[i]; /* May be NULL */
2564 			if (qname)
2565 				set_opt(sb, QUOTA);
2566 			ctx->s_qf_names[i] = NULL;
2567 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2568 						lockdep_is_held(&sb->s_umount));
2569 			if (qname)
2570 				kfree_rcu_mightsleep(qname);
2571 		}
2572 	}
2573 
2574 	if (ctx->spec & EXT4_SPEC_JQFMT)
2575 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2576 #endif
2577 }
2578 
2579 /*
2580  * Check quota settings consistency.
2581  */
2582 static int ext4_check_quota_consistency(struct fs_context *fc,
2583 					struct super_block *sb)
2584 {
2585 #ifdef CONFIG_QUOTA
2586 	struct ext4_fs_context *ctx = fc->fs_private;
2587 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2588 	bool quota_feature = ext4_has_feature_quota(sb);
2589 	bool quota_loaded = sb_any_quota_loaded(sb);
2590 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2591 	int quota_flags, i;
2592 
2593 	/*
2594 	 * We do the test below only for project quotas. 'usrquota' and
2595 	 * 'grpquota' mount options are allowed even without quota feature
2596 	 * to support legacy quotas in quota files.
2597 	 */
2598 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2599 	    !ext4_has_feature_project(sb)) {
2600 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2601 			 "Cannot enable project quota enforcement.");
2602 		return -EINVAL;
2603 	}
2604 
2605 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2606 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2607 	if (quota_loaded &&
2608 	    ctx->mask_s_mount_opt & quota_flags &&
2609 	    !ctx_test_mount_opt(ctx, quota_flags))
2610 		goto err_quota_change;
2611 
2612 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2613 
2614 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2615 			if (!(ctx->qname_spec & (1 << i)))
2616 				continue;
2617 
2618 			if (quota_loaded &&
2619 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2620 				goto err_jquota_change;
2621 
2622 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2623 			    strcmp(get_qf_name(sb, sbi, i),
2624 				   ctx->s_qf_names[i]) != 0)
2625 				goto err_jquota_specified;
2626 		}
2627 
2628 		if (quota_feature) {
2629 			ext4_msg(NULL, KERN_INFO,
2630 				 "Journaled quota options ignored when "
2631 				 "QUOTA feature is enabled");
2632 			return 0;
2633 		}
2634 	}
2635 
2636 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2637 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2638 			goto err_jquota_change;
2639 		if (quota_feature) {
2640 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2641 				 "ignored when QUOTA feature is enabled");
2642 			return 0;
2643 		}
2644 	}
2645 
2646 	/* Make sure we don't mix old and new quota format */
2647 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2648 		       ctx->s_qf_names[USRQUOTA]);
2649 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2650 		       ctx->s_qf_names[GRPQUOTA]);
2651 
2652 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2653 		    test_opt(sb, USRQUOTA));
2654 
2655 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2656 		    test_opt(sb, GRPQUOTA));
2657 
2658 	if (usr_qf_name) {
2659 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2660 		usrquota = false;
2661 	}
2662 	if (grp_qf_name) {
2663 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2664 		grpquota = false;
2665 	}
2666 
2667 	if (usr_qf_name || grp_qf_name) {
2668 		if (usrquota || grpquota) {
2669 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2670 				 "format mixing");
2671 			return -EINVAL;
2672 		}
2673 
2674 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2675 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2676 				 "not specified");
2677 			return -EINVAL;
2678 		}
2679 	}
2680 
2681 	return 0;
2682 
2683 err_quota_change:
2684 	ext4_msg(NULL, KERN_ERR,
2685 		 "Cannot change quota options when quota turned on");
2686 	return -EINVAL;
2687 err_jquota_change:
2688 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2689 		 "options when quota turned on");
2690 	return -EINVAL;
2691 err_jquota_specified:
2692 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2693 		 QTYPE2NAME(i));
2694 	return -EINVAL;
2695 #else
2696 	return 0;
2697 #endif
2698 }
2699 
2700 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2701 					    struct super_block *sb)
2702 {
2703 	const struct ext4_fs_context *ctx = fc->fs_private;
2704 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2705 
2706 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2707 		return 0;
2708 
2709 	if (!ext4_has_feature_encrypt(sb)) {
2710 		ext4_msg(NULL, KERN_WARNING,
2711 			 "test_dummy_encryption requires encrypt feature");
2712 		return -EINVAL;
2713 	}
2714 	/*
2715 	 * This mount option is just for testing, and it's not worthwhile to
2716 	 * implement the extra complexity (e.g. RCU protection) that would be
2717 	 * needed to allow it to be set or changed during remount.  We do allow
2718 	 * it to be specified during remount, but only if there is no change.
2719 	 */
2720 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2721 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2722 						 &ctx->dummy_enc_policy))
2723 			return 0;
2724 		ext4_msg(NULL, KERN_WARNING,
2725 			 "Can't set or change test_dummy_encryption on remount");
2726 		return -EINVAL;
2727 	}
2728 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2729 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2730 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2731 						 &ctx->dummy_enc_policy))
2732 			return 0;
2733 		ext4_msg(NULL, KERN_WARNING,
2734 			 "Conflicting test_dummy_encryption options");
2735 		return -EINVAL;
2736 	}
2737 	return 0;
2738 }
2739 
2740 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2741 					     struct super_block *sb)
2742 {
2743 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2744 	    /* if already set, it was already verified to be the same */
2745 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2746 		return;
2747 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2748 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2749 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2750 }
2751 
2752 static int ext4_check_opt_consistency(struct fs_context *fc,
2753 				      struct super_block *sb)
2754 {
2755 	struct ext4_fs_context *ctx = fc->fs_private;
2756 	struct ext4_sb_info *sbi = fc->s_fs_info;
2757 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2758 	int err;
2759 
2760 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2761 		ext4_msg(NULL, KERN_ERR,
2762 			 "Mount option(s) incompatible with ext2");
2763 		return -EINVAL;
2764 	}
2765 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2766 		ext4_msg(NULL, KERN_ERR,
2767 			 "Mount option(s) incompatible with ext3");
2768 		return -EINVAL;
2769 	}
2770 
2771 	if (ctx->s_want_extra_isize >
2772 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2773 		ext4_msg(NULL, KERN_ERR,
2774 			 "Invalid want_extra_isize %d",
2775 			 ctx->s_want_extra_isize);
2776 		return -EINVAL;
2777 	}
2778 
2779 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2780 		int blocksize =
2781 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2782 		if (blocksize < PAGE_SIZE)
2783 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2784 				 "experimental mount option 'dioread_nolock' "
2785 				 "for blocksize < PAGE_SIZE");
2786 	}
2787 
2788 	err = ext4_check_test_dummy_encryption(fc, sb);
2789 	if (err)
2790 		return err;
2791 
2792 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2793 		if (!sbi->s_journal) {
2794 			ext4_msg(NULL, KERN_WARNING,
2795 				 "Remounting file system with no journal "
2796 				 "so ignoring journalled data option");
2797 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2798 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2799 			   test_opt(sb, DATA_FLAGS)) {
2800 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2801 				 "on remount");
2802 			return -EINVAL;
2803 		}
2804 	}
2805 
2806 	if (is_remount) {
2807 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2808 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2809 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2810 				 "both data=journal and dax");
2811 			return -EINVAL;
2812 		}
2813 
2814 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2815 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2816 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2817 fail_dax_change_remount:
2818 			ext4_msg(NULL, KERN_ERR, "can't change "
2819 				 "dax mount option while remounting");
2820 			return -EINVAL;
2821 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2822 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2823 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2824 			goto fail_dax_change_remount;
2825 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2826 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2827 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2828 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2829 			goto fail_dax_change_remount;
2830 		}
2831 	}
2832 
2833 	return ext4_check_quota_consistency(fc, sb);
2834 }
2835 
2836 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2837 {
2838 	struct ext4_fs_context *ctx = fc->fs_private;
2839 	struct ext4_sb_info *sbi = fc->s_fs_info;
2840 
2841 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2842 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2843 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2844 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2845 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2846 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2847 	sb->s_flags &= ~ctx->mask_s_flags;
2848 	sb->s_flags |= ctx->vals_s_flags;
2849 
2850 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2851 	APPLY(s_commit_interval);
2852 	APPLY(s_stripe);
2853 	APPLY(s_max_batch_time);
2854 	APPLY(s_min_batch_time);
2855 	APPLY(s_want_extra_isize);
2856 	APPLY(s_inode_readahead_blks);
2857 	APPLY(s_max_dir_size_kb);
2858 	APPLY(s_li_wait_mult);
2859 	APPLY(s_resgid);
2860 	APPLY(s_resuid);
2861 
2862 #ifdef CONFIG_EXT4_DEBUG
2863 	APPLY(s_fc_debug_max_replay);
2864 #endif
2865 
2866 	ext4_apply_quota_options(fc, sb);
2867 	ext4_apply_test_dummy_encryption(ctx, sb);
2868 }
2869 
2870 
2871 static int ext4_validate_options(struct fs_context *fc)
2872 {
2873 #ifdef CONFIG_QUOTA
2874 	struct ext4_fs_context *ctx = fc->fs_private;
2875 	char *usr_qf_name, *grp_qf_name;
2876 
2877 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2878 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2879 
2880 	if (usr_qf_name || grp_qf_name) {
2881 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2882 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2883 
2884 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2885 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2886 
2887 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2888 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2889 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2890 				 "format mixing");
2891 			return -EINVAL;
2892 		}
2893 	}
2894 #endif
2895 	return 1;
2896 }
2897 
2898 static inline void ext4_show_quota_options(struct seq_file *seq,
2899 					   struct super_block *sb)
2900 {
2901 #if defined(CONFIG_QUOTA)
2902 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2903 	char *usr_qf_name, *grp_qf_name;
2904 
2905 	if (sbi->s_jquota_fmt) {
2906 		char *fmtname = "";
2907 
2908 		switch (sbi->s_jquota_fmt) {
2909 		case QFMT_VFS_OLD:
2910 			fmtname = "vfsold";
2911 			break;
2912 		case QFMT_VFS_V0:
2913 			fmtname = "vfsv0";
2914 			break;
2915 		case QFMT_VFS_V1:
2916 			fmtname = "vfsv1";
2917 			break;
2918 		}
2919 		seq_printf(seq, ",jqfmt=%s", fmtname);
2920 	}
2921 
2922 	rcu_read_lock();
2923 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2924 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2925 	if (usr_qf_name)
2926 		seq_show_option(seq, "usrjquota", usr_qf_name);
2927 	if (grp_qf_name)
2928 		seq_show_option(seq, "grpjquota", grp_qf_name);
2929 	rcu_read_unlock();
2930 #endif
2931 }
2932 
2933 static const char *token2str(int token)
2934 {
2935 	const struct fs_parameter_spec *spec;
2936 
2937 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2938 		if (spec->opt == token && !spec->type)
2939 			break;
2940 	return spec->name;
2941 }
2942 
2943 /*
2944  * Show an option if
2945  *  - it's set to a non-default value OR
2946  *  - if the per-sb default is different from the global default
2947  */
2948 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2949 			      int nodefs)
2950 {
2951 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2952 	struct ext4_super_block *es = sbi->s_es;
2953 	int def_errors;
2954 	const struct mount_opts *m;
2955 	char sep = nodefs ? '\n' : ',';
2956 
2957 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2958 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2959 
2960 	if (sbi->s_sb_block != 1)
2961 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2962 
2963 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2964 		int want_set = m->flags & MOPT_SET;
2965 		int opt_2 = m->flags & MOPT_2;
2966 		unsigned int mount_opt, def_mount_opt;
2967 
2968 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2969 		    m->flags & MOPT_SKIP)
2970 			continue;
2971 
2972 		if (opt_2) {
2973 			mount_opt = sbi->s_mount_opt2;
2974 			def_mount_opt = sbi->s_def_mount_opt2;
2975 		} else {
2976 			mount_opt = sbi->s_mount_opt;
2977 			def_mount_opt = sbi->s_def_mount_opt;
2978 		}
2979 		/* skip if same as the default */
2980 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2981 			continue;
2982 		/* select Opt_noFoo vs Opt_Foo */
2983 		if ((want_set &&
2984 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2985 		    (!want_set && (mount_opt & m->mount_opt)))
2986 			continue;
2987 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2988 	}
2989 
2990 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2991 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2992 		SEQ_OPTS_PRINT("resuid=%u",
2993 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2994 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2995 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2996 		SEQ_OPTS_PRINT("resgid=%u",
2997 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2998 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2999 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3000 		SEQ_OPTS_PUTS("errors=remount-ro");
3001 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3002 		SEQ_OPTS_PUTS("errors=continue");
3003 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3004 		SEQ_OPTS_PUTS("errors=panic");
3005 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3006 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3007 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3008 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3009 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3010 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3011 	if (nodefs || sbi->s_stripe)
3012 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3013 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3014 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3015 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3016 			SEQ_OPTS_PUTS("data=journal");
3017 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3018 			SEQ_OPTS_PUTS("data=ordered");
3019 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3020 			SEQ_OPTS_PUTS("data=writeback");
3021 	}
3022 	if (nodefs ||
3023 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3024 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3025 			       sbi->s_inode_readahead_blks);
3026 
3027 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3028 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3029 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3030 	if (nodefs || sbi->s_max_dir_size_kb)
3031 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3032 	if (test_opt(sb, DATA_ERR_ABORT))
3033 		SEQ_OPTS_PUTS("data_err=abort");
3034 
3035 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3036 
3037 	if (sb->s_flags & SB_INLINECRYPT)
3038 		SEQ_OPTS_PUTS("inlinecrypt");
3039 
3040 	if (test_opt(sb, DAX_ALWAYS)) {
3041 		if (IS_EXT2_SB(sb))
3042 			SEQ_OPTS_PUTS("dax");
3043 		else
3044 			SEQ_OPTS_PUTS("dax=always");
3045 	} else if (test_opt2(sb, DAX_NEVER)) {
3046 		SEQ_OPTS_PUTS("dax=never");
3047 	} else if (test_opt2(sb, DAX_INODE)) {
3048 		SEQ_OPTS_PUTS("dax=inode");
3049 	}
3050 
3051 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3052 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3053 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3054 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3055 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3056 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3057 	}
3058 
3059 	ext4_show_quota_options(seq, sb);
3060 	return 0;
3061 }
3062 
3063 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3064 {
3065 	return _ext4_show_options(seq, root->d_sb, 0);
3066 }
3067 
3068 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3069 {
3070 	struct super_block *sb = seq->private;
3071 	int rc;
3072 
3073 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3074 	rc = _ext4_show_options(seq, sb, 1);
3075 	seq_puts(seq, "\n");
3076 	return rc;
3077 }
3078 
3079 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3080 			    int read_only)
3081 {
3082 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3083 	int err = 0;
3084 
3085 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3086 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3087 			 "forcing read-only mode");
3088 		err = -EROFS;
3089 		goto done;
3090 	}
3091 	if (read_only)
3092 		goto done;
3093 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3094 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3095 			 "running e2fsck is recommended");
3096 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3097 		ext4_msg(sb, KERN_WARNING,
3098 			 "warning: mounting fs with errors, "
3099 			 "running e2fsck is recommended");
3100 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3101 		 le16_to_cpu(es->s_mnt_count) >=
3102 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3103 		ext4_msg(sb, KERN_WARNING,
3104 			 "warning: maximal mount count reached, "
3105 			 "running e2fsck is recommended");
3106 	else if (le32_to_cpu(es->s_checkinterval) &&
3107 		 (ext4_get_tstamp(es, s_lastcheck) +
3108 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3109 		ext4_msg(sb, KERN_WARNING,
3110 			 "warning: checktime reached, "
3111 			 "running e2fsck is recommended");
3112 	if (!sbi->s_journal)
3113 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3114 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3115 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3116 	le16_add_cpu(&es->s_mnt_count, 1);
3117 	ext4_update_tstamp(es, s_mtime);
3118 	if (sbi->s_journal) {
3119 		ext4_set_feature_journal_needs_recovery(sb);
3120 		if (ext4_has_feature_orphan_file(sb))
3121 			ext4_set_feature_orphan_present(sb);
3122 	}
3123 
3124 	err = ext4_commit_super(sb);
3125 done:
3126 	if (test_opt(sb, DEBUG))
3127 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3128 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3129 			sb->s_blocksize,
3130 			sbi->s_groups_count,
3131 			EXT4_BLOCKS_PER_GROUP(sb),
3132 			EXT4_INODES_PER_GROUP(sb),
3133 			sbi->s_mount_opt, sbi->s_mount_opt2);
3134 	return err;
3135 }
3136 
3137 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3138 {
3139 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3140 	struct flex_groups **old_groups, **new_groups;
3141 	int size, i, j;
3142 
3143 	if (!sbi->s_log_groups_per_flex)
3144 		return 0;
3145 
3146 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3147 	if (size <= sbi->s_flex_groups_allocated)
3148 		return 0;
3149 
3150 	new_groups = kvzalloc(roundup_pow_of_two(size *
3151 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3152 	if (!new_groups) {
3153 		ext4_msg(sb, KERN_ERR,
3154 			 "not enough memory for %d flex group pointers", size);
3155 		return -ENOMEM;
3156 	}
3157 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3158 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3159 					 sizeof(struct flex_groups)),
3160 					 GFP_KERNEL);
3161 		if (!new_groups[i]) {
3162 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3163 				kvfree(new_groups[j]);
3164 			kvfree(new_groups);
3165 			ext4_msg(sb, KERN_ERR,
3166 				 "not enough memory for %d flex groups", size);
3167 			return -ENOMEM;
3168 		}
3169 	}
3170 	rcu_read_lock();
3171 	old_groups = rcu_dereference(sbi->s_flex_groups);
3172 	if (old_groups)
3173 		memcpy(new_groups, old_groups,
3174 		       (sbi->s_flex_groups_allocated *
3175 			sizeof(struct flex_groups *)));
3176 	rcu_read_unlock();
3177 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3178 	sbi->s_flex_groups_allocated = size;
3179 	if (old_groups)
3180 		ext4_kvfree_array_rcu(old_groups);
3181 	return 0;
3182 }
3183 
3184 static int ext4_fill_flex_info(struct super_block *sb)
3185 {
3186 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3187 	struct ext4_group_desc *gdp = NULL;
3188 	struct flex_groups *fg;
3189 	ext4_group_t flex_group;
3190 	int i, err;
3191 
3192 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3193 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3194 		sbi->s_log_groups_per_flex = 0;
3195 		return 1;
3196 	}
3197 
3198 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3199 	if (err)
3200 		goto failed;
3201 
3202 	for (i = 0; i < sbi->s_groups_count; i++) {
3203 		gdp = ext4_get_group_desc(sb, i, NULL);
3204 
3205 		flex_group = ext4_flex_group(sbi, i);
3206 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3207 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3208 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3209 			     &fg->free_clusters);
3210 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3211 	}
3212 
3213 	return 1;
3214 failed:
3215 	return 0;
3216 }
3217 
3218 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3219 				   struct ext4_group_desc *gdp)
3220 {
3221 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3222 	__u16 crc = 0;
3223 	__le32 le_group = cpu_to_le32(block_group);
3224 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3225 
3226 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3227 		/* Use new metadata_csum algorithm */
3228 		__u32 csum32;
3229 		__u16 dummy_csum = 0;
3230 
3231 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3232 				     sizeof(le_group));
3233 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3234 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3235 				     sizeof(dummy_csum));
3236 		offset += sizeof(dummy_csum);
3237 		if (offset < sbi->s_desc_size)
3238 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3239 					     sbi->s_desc_size - offset);
3240 
3241 		crc = csum32 & 0xFFFF;
3242 		goto out;
3243 	}
3244 
3245 	/* old crc16 code */
3246 	if (!ext4_has_feature_gdt_csum(sb))
3247 		return 0;
3248 
3249 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3250 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3251 	crc = crc16(crc, (__u8 *)gdp, offset);
3252 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3253 	/* for checksum of struct ext4_group_desc do the rest...*/
3254 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3255 		crc = crc16(crc, (__u8 *)gdp + offset,
3256 			    sbi->s_desc_size - offset);
3257 
3258 out:
3259 	return cpu_to_le16(crc);
3260 }
3261 
3262 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3263 				struct ext4_group_desc *gdp)
3264 {
3265 	if (ext4_has_group_desc_csum(sb) &&
3266 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3267 		return 0;
3268 
3269 	return 1;
3270 }
3271 
3272 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3273 			      struct ext4_group_desc *gdp)
3274 {
3275 	if (!ext4_has_group_desc_csum(sb))
3276 		return;
3277 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3278 }
3279 
3280 /* Called at mount-time, super-block is locked */
3281 static int ext4_check_descriptors(struct super_block *sb,
3282 				  ext4_fsblk_t sb_block,
3283 				  ext4_group_t *first_not_zeroed)
3284 {
3285 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3286 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3287 	ext4_fsblk_t last_block;
3288 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3289 	ext4_fsblk_t block_bitmap;
3290 	ext4_fsblk_t inode_bitmap;
3291 	ext4_fsblk_t inode_table;
3292 	int flexbg_flag = 0;
3293 	ext4_group_t i, grp = sbi->s_groups_count;
3294 
3295 	if (ext4_has_feature_flex_bg(sb))
3296 		flexbg_flag = 1;
3297 
3298 	ext4_debug("Checking group descriptors");
3299 
3300 	for (i = 0; i < sbi->s_groups_count; i++) {
3301 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3302 
3303 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3304 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3305 		else
3306 			last_block = first_block +
3307 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3308 
3309 		if ((grp == sbi->s_groups_count) &&
3310 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3311 			grp = i;
3312 
3313 		block_bitmap = ext4_block_bitmap(sb, gdp);
3314 		if (block_bitmap == sb_block) {
3315 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3316 				 "Block bitmap for group %u overlaps "
3317 				 "superblock", i);
3318 			if (!sb_rdonly(sb))
3319 				return 0;
3320 		}
3321 		if (block_bitmap >= sb_block + 1 &&
3322 		    block_bitmap <= last_bg_block) {
3323 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3324 				 "Block bitmap for group %u overlaps "
3325 				 "block group descriptors", i);
3326 			if (!sb_rdonly(sb))
3327 				return 0;
3328 		}
3329 		if (block_bitmap < first_block || block_bitmap > last_block) {
3330 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3331 			       "Block bitmap for group %u not in group "
3332 			       "(block %llu)!", i, block_bitmap);
3333 			return 0;
3334 		}
3335 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3336 		if (inode_bitmap == sb_block) {
3337 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3338 				 "Inode bitmap for group %u overlaps "
3339 				 "superblock", i);
3340 			if (!sb_rdonly(sb))
3341 				return 0;
3342 		}
3343 		if (inode_bitmap >= sb_block + 1 &&
3344 		    inode_bitmap <= last_bg_block) {
3345 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3346 				 "Inode bitmap for group %u overlaps "
3347 				 "block group descriptors", i);
3348 			if (!sb_rdonly(sb))
3349 				return 0;
3350 		}
3351 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3352 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3353 			       "Inode bitmap for group %u not in group "
3354 			       "(block %llu)!", i, inode_bitmap);
3355 			return 0;
3356 		}
3357 		inode_table = ext4_inode_table(sb, gdp);
3358 		if (inode_table == sb_block) {
3359 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3360 				 "Inode table for group %u overlaps "
3361 				 "superblock", i);
3362 			if (!sb_rdonly(sb))
3363 				return 0;
3364 		}
3365 		if (inode_table >= sb_block + 1 &&
3366 		    inode_table <= last_bg_block) {
3367 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3368 				 "Inode table for group %u overlaps "
3369 				 "block group descriptors", i);
3370 			if (!sb_rdonly(sb))
3371 				return 0;
3372 		}
3373 		if (inode_table < first_block ||
3374 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3375 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3376 			       "Inode table for group %u not in group "
3377 			       "(block %llu)!", i, inode_table);
3378 			return 0;
3379 		}
3380 		ext4_lock_group(sb, i);
3381 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3382 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3383 				 "Checksum for group %u failed (%u!=%u)",
3384 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3385 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3386 			if (!sb_rdonly(sb)) {
3387 				ext4_unlock_group(sb, i);
3388 				return 0;
3389 			}
3390 		}
3391 		ext4_unlock_group(sb, i);
3392 		if (!flexbg_flag)
3393 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3394 	}
3395 	if (NULL != first_not_zeroed)
3396 		*first_not_zeroed = grp;
3397 	return 1;
3398 }
3399 
3400 /*
3401  * Maximal extent format file size.
3402  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3403  * extent format containers, within a sector_t, and within i_blocks
3404  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3405  * so that won't be a limiting factor.
3406  *
3407  * However there is other limiting factor. We do store extents in the form
3408  * of starting block and length, hence the resulting length of the extent
3409  * covering maximum file size must fit into on-disk format containers as
3410  * well. Given that length is always by 1 unit bigger than max unit (because
3411  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3412  *
3413  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3414  */
3415 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3416 {
3417 	loff_t res;
3418 	loff_t upper_limit = MAX_LFS_FILESIZE;
3419 
3420 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3421 
3422 	if (!has_huge_files) {
3423 		upper_limit = (1LL << 32) - 1;
3424 
3425 		/* total blocks in file system block size */
3426 		upper_limit >>= (blkbits - 9);
3427 		upper_limit <<= blkbits;
3428 	}
3429 
3430 	/*
3431 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3432 	 * by one fs block, so ee_len can cover the extent of maximum file
3433 	 * size
3434 	 */
3435 	res = (1LL << 32) - 1;
3436 	res <<= blkbits;
3437 
3438 	/* Sanity check against vm- & vfs- imposed limits */
3439 	if (res > upper_limit)
3440 		res = upper_limit;
3441 
3442 	return res;
3443 }
3444 
3445 /*
3446  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3447  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3448  * We need to be 1 filesystem block less than the 2^48 sector limit.
3449  */
3450 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3451 {
3452 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3453 	int meta_blocks;
3454 	unsigned int ppb = 1 << (bits - 2);
3455 
3456 	/*
3457 	 * This is calculated to be the largest file size for a dense, block
3458 	 * mapped file such that the file's total number of 512-byte sectors,
3459 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3460 	 *
3461 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3462 	 * number of 512-byte sectors of the file.
3463 	 */
3464 	if (!has_huge_files) {
3465 		/*
3466 		 * !has_huge_files or implies that the inode i_block field
3467 		 * represents total file blocks in 2^32 512-byte sectors ==
3468 		 * size of vfs inode i_blocks * 8
3469 		 */
3470 		upper_limit = (1LL << 32) - 1;
3471 
3472 		/* total blocks in file system block size */
3473 		upper_limit >>= (bits - 9);
3474 
3475 	} else {
3476 		/*
3477 		 * We use 48 bit ext4_inode i_blocks
3478 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3479 		 * represent total number of blocks in
3480 		 * file system block size
3481 		 */
3482 		upper_limit = (1LL << 48) - 1;
3483 
3484 	}
3485 
3486 	/* Compute how many blocks we can address by block tree */
3487 	res += ppb;
3488 	res += ppb * ppb;
3489 	res += ((loff_t)ppb) * ppb * ppb;
3490 	/* Compute how many metadata blocks are needed */
3491 	meta_blocks = 1;
3492 	meta_blocks += 1 + ppb;
3493 	meta_blocks += 1 + ppb + ppb * ppb;
3494 	/* Does block tree limit file size? */
3495 	if (res + meta_blocks <= upper_limit)
3496 		goto check_lfs;
3497 
3498 	res = upper_limit;
3499 	/* How many metadata blocks are needed for addressing upper_limit? */
3500 	upper_limit -= EXT4_NDIR_BLOCKS;
3501 	/* indirect blocks */
3502 	meta_blocks = 1;
3503 	upper_limit -= ppb;
3504 	/* double indirect blocks */
3505 	if (upper_limit < ppb * ppb) {
3506 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3507 		res -= meta_blocks;
3508 		goto check_lfs;
3509 	}
3510 	meta_blocks += 1 + ppb;
3511 	upper_limit -= ppb * ppb;
3512 	/* tripple indirect blocks for the rest */
3513 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3514 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3515 	res -= meta_blocks;
3516 check_lfs:
3517 	res <<= bits;
3518 	if (res > MAX_LFS_FILESIZE)
3519 		res = MAX_LFS_FILESIZE;
3520 
3521 	return res;
3522 }
3523 
3524 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3525 				   ext4_fsblk_t logical_sb_block, int nr)
3526 {
3527 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3528 	ext4_group_t bg, first_meta_bg;
3529 	int has_super = 0;
3530 
3531 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3532 
3533 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3534 		return logical_sb_block + nr + 1;
3535 	bg = sbi->s_desc_per_block * nr;
3536 	if (ext4_bg_has_super(sb, bg))
3537 		has_super = 1;
3538 
3539 	/*
3540 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3541 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3542 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3543 	 * compensate.
3544 	 */
3545 	if (sb->s_blocksize == 1024 && nr == 0 &&
3546 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3547 		has_super++;
3548 
3549 	return (has_super + ext4_group_first_block_no(sb, bg));
3550 }
3551 
3552 /**
3553  * ext4_get_stripe_size: Get the stripe size.
3554  * @sbi: In memory super block info
3555  *
3556  * If we have specified it via mount option, then
3557  * use the mount option value. If the value specified at mount time is
3558  * greater than the blocks per group use the super block value.
3559  * If the super block value is greater than blocks per group return 0.
3560  * Allocator needs it be less than blocks per group.
3561  *
3562  */
3563 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3564 {
3565 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3566 	unsigned long stripe_width =
3567 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3568 	int ret;
3569 
3570 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3571 		ret = sbi->s_stripe;
3572 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3573 		ret = stripe_width;
3574 	else if (stride && stride <= sbi->s_blocks_per_group)
3575 		ret = stride;
3576 	else
3577 		ret = 0;
3578 
3579 	/*
3580 	 * If the stripe width is 1, this makes no sense and
3581 	 * we set it to 0 to turn off stripe handling code.
3582 	 */
3583 	if (ret <= 1)
3584 		ret = 0;
3585 
3586 	return ret;
3587 }
3588 
3589 /*
3590  * Check whether this filesystem can be mounted based on
3591  * the features present and the RDONLY/RDWR mount requested.
3592  * Returns 1 if this filesystem can be mounted as requested,
3593  * 0 if it cannot be.
3594  */
3595 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3596 {
3597 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3598 		ext4_msg(sb, KERN_ERR,
3599 			"Couldn't mount because of "
3600 			"unsupported optional features (%x)",
3601 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3602 			~EXT4_FEATURE_INCOMPAT_SUPP));
3603 		return 0;
3604 	}
3605 
3606 #if !IS_ENABLED(CONFIG_UNICODE)
3607 	if (ext4_has_feature_casefold(sb)) {
3608 		ext4_msg(sb, KERN_ERR,
3609 			 "Filesystem with casefold feature cannot be "
3610 			 "mounted without CONFIG_UNICODE");
3611 		return 0;
3612 	}
3613 #endif
3614 
3615 	if (readonly)
3616 		return 1;
3617 
3618 	if (ext4_has_feature_readonly(sb)) {
3619 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3620 		sb->s_flags |= SB_RDONLY;
3621 		return 1;
3622 	}
3623 
3624 	/* Check that feature set is OK for a read-write mount */
3625 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3626 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3627 			 "unsupported optional features (%x)",
3628 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3629 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3630 		return 0;
3631 	}
3632 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3633 		ext4_msg(sb, KERN_ERR,
3634 			 "Can't support bigalloc feature without "
3635 			 "extents feature\n");
3636 		return 0;
3637 	}
3638 
3639 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3640 	if (!readonly && (ext4_has_feature_quota(sb) ||
3641 			  ext4_has_feature_project(sb))) {
3642 		ext4_msg(sb, KERN_ERR,
3643 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3644 		return 0;
3645 	}
3646 #endif  /* CONFIG_QUOTA */
3647 	return 1;
3648 }
3649 
3650 /*
3651  * This function is called once a day if we have errors logged
3652  * on the file system
3653  */
3654 static void print_daily_error_info(struct timer_list *t)
3655 {
3656 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3657 	struct super_block *sb = sbi->s_sb;
3658 	struct ext4_super_block *es = sbi->s_es;
3659 
3660 	if (es->s_error_count)
3661 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3662 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3663 			 le32_to_cpu(es->s_error_count));
3664 	if (es->s_first_error_time) {
3665 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3666 		       sb->s_id,
3667 		       ext4_get_tstamp(es, s_first_error_time),
3668 		       (int) sizeof(es->s_first_error_func),
3669 		       es->s_first_error_func,
3670 		       le32_to_cpu(es->s_first_error_line));
3671 		if (es->s_first_error_ino)
3672 			printk(KERN_CONT ": inode %u",
3673 			       le32_to_cpu(es->s_first_error_ino));
3674 		if (es->s_first_error_block)
3675 			printk(KERN_CONT ": block %llu", (unsigned long long)
3676 			       le64_to_cpu(es->s_first_error_block));
3677 		printk(KERN_CONT "\n");
3678 	}
3679 	if (es->s_last_error_time) {
3680 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3681 		       sb->s_id,
3682 		       ext4_get_tstamp(es, s_last_error_time),
3683 		       (int) sizeof(es->s_last_error_func),
3684 		       es->s_last_error_func,
3685 		       le32_to_cpu(es->s_last_error_line));
3686 		if (es->s_last_error_ino)
3687 			printk(KERN_CONT ": inode %u",
3688 			       le32_to_cpu(es->s_last_error_ino));
3689 		if (es->s_last_error_block)
3690 			printk(KERN_CONT ": block %llu", (unsigned long long)
3691 			       le64_to_cpu(es->s_last_error_block));
3692 		printk(KERN_CONT "\n");
3693 	}
3694 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3695 }
3696 
3697 /* Find next suitable group and run ext4_init_inode_table */
3698 static int ext4_run_li_request(struct ext4_li_request *elr)
3699 {
3700 	struct ext4_group_desc *gdp = NULL;
3701 	struct super_block *sb = elr->lr_super;
3702 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3703 	ext4_group_t group = elr->lr_next_group;
3704 	unsigned int prefetch_ios = 0;
3705 	int ret = 0;
3706 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3707 	u64 start_time;
3708 
3709 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3710 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3711 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3712 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3713 		if (group >= elr->lr_next_group) {
3714 			ret = 1;
3715 			if (elr->lr_first_not_zeroed != ngroups &&
3716 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3717 				elr->lr_next_group = elr->lr_first_not_zeroed;
3718 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3719 				ret = 0;
3720 			}
3721 		}
3722 		return ret;
3723 	}
3724 
3725 	for (; group < ngroups; group++) {
3726 		gdp = ext4_get_group_desc(sb, group, NULL);
3727 		if (!gdp) {
3728 			ret = 1;
3729 			break;
3730 		}
3731 
3732 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3733 			break;
3734 	}
3735 
3736 	if (group >= ngroups)
3737 		ret = 1;
3738 
3739 	if (!ret) {
3740 		start_time = ktime_get_real_ns();
3741 		ret = ext4_init_inode_table(sb, group,
3742 					    elr->lr_timeout ? 0 : 1);
3743 		trace_ext4_lazy_itable_init(sb, group);
3744 		if (elr->lr_timeout == 0) {
3745 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3746 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3747 		}
3748 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3749 		elr->lr_next_group = group + 1;
3750 	}
3751 	return ret;
3752 }
3753 
3754 /*
3755  * Remove lr_request from the list_request and free the
3756  * request structure. Should be called with li_list_mtx held
3757  */
3758 static void ext4_remove_li_request(struct ext4_li_request *elr)
3759 {
3760 	if (!elr)
3761 		return;
3762 
3763 	list_del(&elr->lr_request);
3764 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3765 	kfree(elr);
3766 }
3767 
3768 static void ext4_unregister_li_request(struct super_block *sb)
3769 {
3770 	mutex_lock(&ext4_li_mtx);
3771 	if (!ext4_li_info) {
3772 		mutex_unlock(&ext4_li_mtx);
3773 		return;
3774 	}
3775 
3776 	mutex_lock(&ext4_li_info->li_list_mtx);
3777 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3778 	mutex_unlock(&ext4_li_info->li_list_mtx);
3779 	mutex_unlock(&ext4_li_mtx);
3780 }
3781 
3782 static struct task_struct *ext4_lazyinit_task;
3783 
3784 /*
3785  * This is the function where ext4lazyinit thread lives. It walks
3786  * through the request list searching for next scheduled filesystem.
3787  * When such a fs is found, run the lazy initialization request
3788  * (ext4_rn_li_request) and keep track of the time spend in this
3789  * function. Based on that time we compute next schedule time of
3790  * the request. When walking through the list is complete, compute
3791  * next waking time and put itself into sleep.
3792  */
3793 static int ext4_lazyinit_thread(void *arg)
3794 {
3795 	struct ext4_lazy_init *eli = arg;
3796 	struct list_head *pos, *n;
3797 	struct ext4_li_request *elr;
3798 	unsigned long next_wakeup, cur;
3799 
3800 	BUG_ON(NULL == eli);
3801 	set_freezable();
3802 
3803 cont_thread:
3804 	while (true) {
3805 		next_wakeup = MAX_JIFFY_OFFSET;
3806 
3807 		mutex_lock(&eli->li_list_mtx);
3808 		if (list_empty(&eli->li_request_list)) {
3809 			mutex_unlock(&eli->li_list_mtx);
3810 			goto exit_thread;
3811 		}
3812 		list_for_each_safe(pos, n, &eli->li_request_list) {
3813 			int err = 0;
3814 			int progress = 0;
3815 			elr = list_entry(pos, struct ext4_li_request,
3816 					 lr_request);
3817 
3818 			if (time_before(jiffies, elr->lr_next_sched)) {
3819 				if (time_before(elr->lr_next_sched, next_wakeup))
3820 					next_wakeup = elr->lr_next_sched;
3821 				continue;
3822 			}
3823 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3824 				if (sb_start_write_trylock(elr->lr_super)) {
3825 					progress = 1;
3826 					/*
3827 					 * We hold sb->s_umount, sb can not
3828 					 * be removed from the list, it is
3829 					 * now safe to drop li_list_mtx
3830 					 */
3831 					mutex_unlock(&eli->li_list_mtx);
3832 					err = ext4_run_li_request(elr);
3833 					sb_end_write(elr->lr_super);
3834 					mutex_lock(&eli->li_list_mtx);
3835 					n = pos->next;
3836 				}
3837 				up_read((&elr->lr_super->s_umount));
3838 			}
3839 			/* error, remove the lazy_init job */
3840 			if (err) {
3841 				ext4_remove_li_request(elr);
3842 				continue;
3843 			}
3844 			if (!progress) {
3845 				elr->lr_next_sched = jiffies +
3846 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3847 			}
3848 			if (time_before(elr->lr_next_sched, next_wakeup))
3849 				next_wakeup = elr->lr_next_sched;
3850 		}
3851 		mutex_unlock(&eli->li_list_mtx);
3852 
3853 		try_to_freeze();
3854 
3855 		cur = jiffies;
3856 		if ((time_after_eq(cur, next_wakeup)) ||
3857 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3858 			cond_resched();
3859 			continue;
3860 		}
3861 
3862 		schedule_timeout_interruptible(next_wakeup - cur);
3863 
3864 		if (kthread_should_stop()) {
3865 			ext4_clear_request_list();
3866 			goto exit_thread;
3867 		}
3868 	}
3869 
3870 exit_thread:
3871 	/*
3872 	 * It looks like the request list is empty, but we need
3873 	 * to check it under the li_list_mtx lock, to prevent any
3874 	 * additions into it, and of course we should lock ext4_li_mtx
3875 	 * to atomically free the list and ext4_li_info, because at
3876 	 * this point another ext4 filesystem could be registering
3877 	 * new one.
3878 	 */
3879 	mutex_lock(&ext4_li_mtx);
3880 	mutex_lock(&eli->li_list_mtx);
3881 	if (!list_empty(&eli->li_request_list)) {
3882 		mutex_unlock(&eli->li_list_mtx);
3883 		mutex_unlock(&ext4_li_mtx);
3884 		goto cont_thread;
3885 	}
3886 	mutex_unlock(&eli->li_list_mtx);
3887 	kfree(ext4_li_info);
3888 	ext4_li_info = NULL;
3889 	mutex_unlock(&ext4_li_mtx);
3890 
3891 	return 0;
3892 }
3893 
3894 static void ext4_clear_request_list(void)
3895 {
3896 	struct list_head *pos, *n;
3897 	struct ext4_li_request *elr;
3898 
3899 	mutex_lock(&ext4_li_info->li_list_mtx);
3900 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3901 		elr = list_entry(pos, struct ext4_li_request,
3902 				 lr_request);
3903 		ext4_remove_li_request(elr);
3904 	}
3905 	mutex_unlock(&ext4_li_info->li_list_mtx);
3906 }
3907 
3908 static int ext4_run_lazyinit_thread(void)
3909 {
3910 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3911 					 ext4_li_info, "ext4lazyinit");
3912 	if (IS_ERR(ext4_lazyinit_task)) {
3913 		int err = PTR_ERR(ext4_lazyinit_task);
3914 		ext4_clear_request_list();
3915 		kfree(ext4_li_info);
3916 		ext4_li_info = NULL;
3917 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3918 				 "initialization thread\n",
3919 				 err);
3920 		return err;
3921 	}
3922 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3923 	return 0;
3924 }
3925 
3926 /*
3927  * Check whether it make sense to run itable init. thread or not.
3928  * If there is at least one uninitialized inode table, return
3929  * corresponding group number, else the loop goes through all
3930  * groups and return total number of groups.
3931  */
3932 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3933 {
3934 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3935 	struct ext4_group_desc *gdp = NULL;
3936 
3937 	if (!ext4_has_group_desc_csum(sb))
3938 		return ngroups;
3939 
3940 	for (group = 0; group < ngroups; group++) {
3941 		gdp = ext4_get_group_desc(sb, group, NULL);
3942 		if (!gdp)
3943 			continue;
3944 
3945 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3946 			break;
3947 	}
3948 
3949 	return group;
3950 }
3951 
3952 static int ext4_li_info_new(void)
3953 {
3954 	struct ext4_lazy_init *eli = NULL;
3955 
3956 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3957 	if (!eli)
3958 		return -ENOMEM;
3959 
3960 	INIT_LIST_HEAD(&eli->li_request_list);
3961 	mutex_init(&eli->li_list_mtx);
3962 
3963 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3964 
3965 	ext4_li_info = eli;
3966 
3967 	return 0;
3968 }
3969 
3970 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3971 					    ext4_group_t start)
3972 {
3973 	struct ext4_li_request *elr;
3974 
3975 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3976 	if (!elr)
3977 		return NULL;
3978 
3979 	elr->lr_super = sb;
3980 	elr->lr_first_not_zeroed = start;
3981 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3982 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3983 		elr->lr_next_group = start;
3984 	} else {
3985 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3986 	}
3987 
3988 	/*
3989 	 * Randomize first schedule time of the request to
3990 	 * spread the inode table initialization requests
3991 	 * better.
3992 	 */
3993 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3994 	return elr;
3995 }
3996 
3997 int ext4_register_li_request(struct super_block *sb,
3998 			     ext4_group_t first_not_zeroed)
3999 {
4000 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4001 	struct ext4_li_request *elr = NULL;
4002 	ext4_group_t ngroups = sbi->s_groups_count;
4003 	int ret = 0;
4004 
4005 	mutex_lock(&ext4_li_mtx);
4006 	if (sbi->s_li_request != NULL) {
4007 		/*
4008 		 * Reset timeout so it can be computed again, because
4009 		 * s_li_wait_mult might have changed.
4010 		 */
4011 		sbi->s_li_request->lr_timeout = 0;
4012 		goto out;
4013 	}
4014 
4015 	if (sb_rdonly(sb) ||
4016 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4017 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4018 		goto out;
4019 
4020 	elr = ext4_li_request_new(sb, first_not_zeroed);
4021 	if (!elr) {
4022 		ret = -ENOMEM;
4023 		goto out;
4024 	}
4025 
4026 	if (NULL == ext4_li_info) {
4027 		ret = ext4_li_info_new();
4028 		if (ret)
4029 			goto out;
4030 	}
4031 
4032 	mutex_lock(&ext4_li_info->li_list_mtx);
4033 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4034 	mutex_unlock(&ext4_li_info->li_list_mtx);
4035 
4036 	sbi->s_li_request = elr;
4037 	/*
4038 	 * set elr to NULL here since it has been inserted to
4039 	 * the request_list and the removal and free of it is
4040 	 * handled by ext4_clear_request_list from now on.
4041 	 */
4042 	elr = NULL;
4043 
4044 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4045 		ret = ext4_run_lazyinit_thread();
4046 		if (ret)
4047 			goto out;
4048 	}
4049 out:
4050 	mutex_unlock(&ext4_li_mtx);
4051 	if (ret)
4052 		kfree(elr);
4053 	return ret;
4054 }
4055 
4056 /*
4057  * We do not need to lock anything since this is called on
4058  * module unload.
4059  */
4060 static void ext4_destroy_lazyinit_thread(void)
4061 {
4062 	/*
4063 	 * If thread exited earlier
4064 	 * there's nothing to be done.
4065 	 */
4066 	if (!ext4_li_info || !ext4_lazyinit_task)
4067 		return;
4068 
4069 	kthread_stop(ext4_lazyinit_task);
4070 }
4071 
4072 static int set_journal_csum_feature_set(struct super_block *sb)
4073 {
4074 	int ret = 1;
4075 	int compat, incompat;
4076 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4077 
4078 	if (ext4_has_metadata_csum(sb)) {
4079 		/* journal checksum v3 */
4080 		compat = 0;
4081 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4082 	} else {
4083 		/* journal checksum v1 */
4084 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4085 		incompat = 0;
4086 	}
4087 
4088 	jbd2_journal_clear_features(sbi->s_journal,
4089 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4090 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4091 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4092 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4093 		ret = jbd2_journal_set_features(sbi->s_journal,
4094 				compat, 0,
4095 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4096 				incompat);
4097 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4098 		ret = jbd2_journal_set_features(sbi->s_journal,
4099 				compat, 0,
4100 				incompat);
4101 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4102 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4103 	} else {
4104 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4105 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4106 	}
4107 
4108 	return ret;
4109 }
4110 
4111 /*
4112  * Note: calculating the overhead so we can be compatible with
4113  * historical BSD practice is quite difficult in the face of
4114  * clusters/bigalloc.  This is because multiple metadata blocks from
4115  * different block group can end up in the same allocation cluster.
4116  * Calculating the exact overhead in the face of clustered allocation
4117  * requires either O(all block bitmaps) in memory or O(number of block
4118  * groups**2) in time.  We will still calculate the superblock for
4119  * older file systems --- and if we come across with a bigalloc file
4120  * system with zero in s_overhead_clusters the estimate will be close to
4121  * correct especially for very large cluster sizes --- but for newer
4122  * file systems, it's better to calculate this figure once at mkfs
4123  * time, and store it in the superblock.  If the superblock value is
4124  * present (even for non-bigalloc file systems), we will use it.
4125  */
4126 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4127 			  char *buf)
4128 {
4129 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4130 	struct ext4_group_desc	*gdp;
4131 	ext4_fsblk_t		first_block, last_block, b;
4132 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4133 	int			s, j, count = 0;
4134 	int			has_super = ext4_bg_has_super(sb, grp);
4135 
4136 	if (!ext4_has_feature_bigalloc(sb))
4137 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4138 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4139 			sbi->s_itb_per_group + 2);
4140 
4141 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4142 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4143 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4144 	for (i = 0; i < ngroups; i++) {
4145 		gdp = ext4_get_group_desc(sb, i, NULL);
4146 		b = ext4_block_bitmap(sb, gdp);
4147 		if (b >= first_block && b <= last_block) {
4148 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4149 			count++;
4150 		}
4151 		b = ext4_inode_bitmap(sb, gdp);
4152 		if (b >= first_block && b <= last_block) {
4153 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4154 			count++;
4155 		}
4156 		b = ext4_inode_table(sb, gdp);
4157 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4158 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4159 				int c = EXT4_B2C(sbi, b - first_block);
4160 				ext4_set_bit(c, buf);
4161 				count++;
4162 			}
4163 		if (i != grp)
4164 			continue;
4165 		s = 0;
4166 		if (ext4_bg_has_super(sb, grp)) {
4167 			ext4_set_bit(s++, buf);
4168 			count++;
4169 		}
4170 		j = ext4_bg_num_gdb(sb, grp);
4171 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4172 			ext4_error(sb, "Invalid number of block group "
4173 				   "descriptor blocks: %d", j);
4174 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4175 		}
4176 		count += j;
4177 		for (; j > 0; j--)
4178 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4179 	}
4180 	if (!count)
4181 		return 0;
4182 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4183 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4184 }
4185 
4186 /*
4187  * Compute the overhead and stash it in sbi->s_overhead
4188  */
4189 int ext4_calculate_overhead(struct super_block *sb)
4190 {
4191 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4192 	struct ext4_super_block *es = sbi->s_es;
4193 	struct inode *j_inode;
4194 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4195 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4196 	ext4_fsblk_t overhead = 0;
4197 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4198 
4199 	if (!buf)
4200 		return -ENOMEM;
4201 
4202 	/*
4203 	 * Compute the overhead (FS structures).  This is constant
4204 	 * for a given filesystem unless the number of block groups
4205 	 * changes so we cache the previous value until it does.
4206 	 */
4207 
4208 	/*
4209 	 * All of the blocks before first_data_block are overhead
4210 	 */
4211 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4212 
4213 	/*
4214 	 * Add the overhead found in each block group
4215 	 */
4216 	for (i = 0; i < ngroups; i++) {
4217 		int blks;
4218 
4219 		blks = count_overhead(sb, i, buf);
4220 		overhead += blks;
4221 		if (blks)
4222 			memset(buf, 0, PAGE_SIZE);
4223 		cond_resched();
4224 	}
4225 
4226 	/*
4227 	 * Add the internal journal blocks whether the journal has been
4228 	 * loaded or not
4229 	 */
4230 	if (sbi->s_journal && !sbi->s_journal_bdev)
4231 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4232 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4233 		/* j_inum for internal journal is non-zero */
4234 		j_inode = ext4_get_journal_inode(sb, j_inum);
4235 		if (j_inode) {
4236 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4237 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4238 			iput(j_inode);
4239 		} else {
4240 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4241 		}
4242 	}
4243 	sbi->s_overhead = overhead;
4244 	smp_wmb();
4245 	free_page((unsigned long) buf);
4246 	return 0;
4247 }
4248 
4249 static void ext4_set_resv_clusters(struct super_block *sb)
4250 {
4251 	ext4_fsblk_t resv_clusters;
4252 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4253 
4254 	/*
4255 	 * There's no need to reserve anything when we aren't using extents.
4256 	 * The space estimates are exact, there are no unwritten extents,
4257 	 * hole punching doesn't need new metadata... This is needed especially
4258 	 * to keep ext2/3 backward compatibility.
4259 	 */
4260 	if (!ext4_has_feature_extents(sb))
4261 		return;
4262 	/*
4263 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4264 	 * This should cover the situations where we can not afford to run
4265 	 * out of space like for example punch hole, or converting
4266 	 * unwritten extents in delalloc path. In most cases such
4267 	 * allocation would require 1, or 2 blocks, higher numbers are
4268 	 * very rare.
4269 	 */
4270 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4271 			 sbi->s_cluster_bits);
4272 
4273 	do_div(resv_clusters, 50);
4274 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4275 
4276 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4277 }
4278 
4279 static const char *ext4_quota_mode(struct super_block *sb)
4280 {
4281 #ifdef CONFIG_QUOTA
4282 	if (!ext4_quota_capable(sb))
4283 		return "none";
4284 
4285 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4286 		return "journalled";
4287 	else
4288 		return "writeback";
4289 #else
4290 	return "disabled";
4291 #endif
4292 }
4293 
4294 static void ext4_setup_csum_trigger(struct super_block *sb,
4295 				    enum ext4_journal_trigger_type type,
4296 				    void (*trigger)(
4297 					struct jbd2_buffer_trigger_type *type,
4298 					struct buffer_head *bh,
4299 					void *mapped_data,
4300 					size_t size))
4301 {
4302 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4303 
4304 	sbi->s_journal_triggers[type].sb = sb;
4305 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4306 }
4307 
4308 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4309 {
4310 	if (!sbi)
4311 		return;
4312 
4313 	kfree(sbi->s_blockgroup_lock);
4314 	fs_put_dax(sbi->s_daxdev, NULL);
4315 	kfree(sbi);
4316 }
4317 
4318 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4319 {
4320 	struct ext4_sb_info *sbi;
4321 
4322 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4323 	if (!sbi)
4324 		return NULL;
4325 
4326 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4327 					   NULL, NULL);
4328 
4329 	sbi->s_blockgroup_lock =
4330 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4331 
4332 	if (!sbi->s_blockgroup_lock)
4333 		goto err_out;
4334 
4335 	sb->s_fs_info = sbi;
4336 	sbi->s_sb = sb;
4337 	return sbi;
4338 err_out:
4339 	fs_put_dax(sbi->s_daxdev, NULL);
4340 	kfree(sbi);
4341 	return NULL;
4342 }
4343 
4344 static void ext4_set_def_opts(struct super_block *sb,
4345 			      struct ext4_super_block *es)
4346 {
4347 	unsigned long def_mount_opts;
4348 
4349 	/* Set defaults before we parse the mount options */
4350 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4351 	set_opt(sb, INIT_INODE_TABLE);
4352 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4353 		set_opt(sb, DEBUG);
4354 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4355 		set_opt(sb, GRPID);
4356 	if (def_mount_opts & EXT4_DEFM_UID16)
4357 		set_opt(sb, NO_UID32);
4358 	/* xattr user namespace & acls are now defaulted on */
4359 	set_opt(sb, XATTR_USER);
4360 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4361 	set_opt(sb, POSIX_ACL);
4362 #endif
4363 	if (ext4_has_feature_fast_commit(sb))
4364 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4365 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4366 	if (ext4_has_metadata_csum(sb))
4367 		set_opt(sb, JOURNAL_CHECKSUM);
4368 
4369 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4370 		set_opt(sb, JOURNAL_DATA);
4371 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4372 		set_opt(sb, ORDERED_DATA);
4373 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4374 		set_opt(sb, WRITEBACK_DATA);
4375 
4376 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4377 		set_opt(sb, ERRORS_PANIC);
4378 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4379 		set_opt(sb, ERRORS_CONT);
4380 	else
4381 		set_opt(sb, ERRORS_RO);
4382 	/* block_validity enabled by default; disable with noblock_validity */
4383 	set_opt(sb, BLOCK_VALIDITY);
4384 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4385 		set_opt(sb, DISCARD);
4386 
4387 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4388 		set_opt(sb, BARRIER);
4389 
4390 	/*
4391 	 * enable delayed allocation by default
4392 	 * Use -o nodelalloc to turn it off
4393 	 */
4394 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4395 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4396 		set_opt(sb, DELALLOC);
4397 
4398 	if (sb->s_blocksize == PAGE_SIZE)
4399 		set_opt(sb, DIOREAD_NOLOCK);
4400 }
4401 
4402 static int ext4_handle_clustersize(struct super_block *sb)
4403 {
4404 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4405 	struct ext4_super_block *es = sbi->s_es;
4406 	int clustersize;
4407 
4408 	/* Handle clustersize */
4409 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4410 	if (ext4_has_feature_bigalloc(sb)) {
4411 		if (clustersize < sb->s_blocksize) {
4412 			ext4_msg(sb, KERN_ERR,
4413 				 "cluster size (%d) smaller than "
4414 				 "block size (%lu)", clustersize, sb->s_blocksize);
4415 			return -EINVAL;
4416 		}
4417 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4418 			le32_to_cpu(es->s_log_block_size);
4419 		sbi->s_clusters_per_group =
4420 			le32_to_cpu(es->s_clusters_per_group);
4421 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4422 			ext4_msg(sb, KERN_ERR,
4423 				 "#clusters per group too big: %lu",
4424 				 sbi->s_clusters_per_group);
4425 			return -EINVAL;
4426 		}
4427 		if (sbi->s_blocks_per_group !=
4428 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4429 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4430 				 "clusters per group (%lu) inconsistent",
4431 				 sbi->s_blocks_per_group,
4432 				 sbi->s_clusters_per_group);
4433 			return -EINVAL;
4434 		}
4435 	} else {
4436 		if (clustersize != sb->s_blocksize) {
4437 			ext4_msg(sb, KERN_ERR,
4438 				 "fragment/cluster size (%d) != "
4439 				 "block size (%lu)", clustersize, sb->s_blocksize);
4440 			return -EINVAL;
4441 		}
4442 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4443 			ext4_msg(sb, KERN_ERR,
4444 				 "#blocks per group too big: %lu",
4445 				 sbi->s_blocks_per_group);
4446 			return -EINVAL;
4447 		}
4448 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4449 		sbi->s_cluster_bits = 0;
4450 	}
4451 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4452 
4453 	/* Do we have standard group size of clustersize * 8 blocks ? */
4454 	if (sbi->s_blocks_per_group == clustersize << 3)
4455 		set_opt2(sb, STD_GROUP_SIZE);
4456 
4457 	return 0;
4458 }
4459 
4460 static void ext4_fast_commit_init(struct super_block *sb)
4461 {
4462 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4463 
4464 	/* Initialize fast commit stuff */
4465 	atomic_set(&sbi->s_fc_subtid, 0);
4466 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4467 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4468 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4469 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4470 	sbi->s_fc_bytes = 0;
4471 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4472 	sbi->s_fc_ineligible_tid = 0;
4473 	spin_lock_init(&sbi->s_fc_lock);
4474 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4475 	sbi->s_fc_replay_state.fc_regions = NULL;
4476 	sbi->s_fc_replay_state.fc_regions_size = 0;
4477 	sbi->s_fc_replay_state.fc_regions_used = 0;
4478 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4479 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4480 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4481 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4482 }
4483 
4484 static int ext4_inode_info_init(struct super_block *sb,
4485 				struct ext4_super_block *es)
4486 {
4487 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4488 
4489 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4490 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4491 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4492 	} else {
4493 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4494 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4495 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4496 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4497 				 sbi->s_first_ino);
4498 			return -EINVAL;
4499 		}
4500 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4501 		    (!is_power_of_2(sbi->s_inode_size)) ||
4502 		    (sbi->s_inode_size > sb->s_blocksize)) {
4503 			ext4_msg(sb, KERN_ERR,
4504 			       "unsupported inode size: %d",
4505 			       sbi->s_inode_size);
4506 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4507 			return -EINVAL;
4508 		}
4509 		/*
4510 		 * i_atime_extra is the last extra field available for
4511 		 * [acm]times in struct ext4_inode. Checking for that
4512 		 * field should suffice to ensure we have extra space
4513 		 * for all three.
4514 		 */
4515 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4516 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4517 			sb->s_time_gran = 1;
4518 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4519 		} else {
4520 			sb->s_time_gran = NSEC_PER_SEC;
4521 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4522 		}
4523 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4524 	}
4525 
4526 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4527 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4528 			EXT4_GOOD_OLD_INODE_SIZE;
4529 		if (ext4_has_feature_extra_isize(sb)) {
4530 			unsigned v, max = (sbi->s_inode_size -
4531 					   EXT4_GOOD_OLD_INODE_SIZE);
4532 
4533 			v = le16_to_cpu(es->s_want_extra_isize);
4534 			if (v > max) {
4535 				ext4_msg(sb, KERN_ERR,
4536 					 "bad s_want_extra_isize: %d", v);
4537 				return -EINVAL;
4538 			}
4539 			if (sbi->s_want_extra_isize < v)
4540 				sbi->s_want_extra_isize = v;
4541 
4542 			v = le16_to_cpu(es->s_min_extra_isize);
4543 			if (v > max) {
4544 				ext4_msg(sb, KERN_ERR,
4545 					 "bad s_min_extra_isize: %d", v);
4546 				return -EINVAL;
4547 			}
4548 			if (sbi->s_want_extra_isize < v)
4549 				sbi->s_want_extra_isize = v;
4550 		}
4551 	}
4552 
4553 	return 0;
4554 }
4555 
4556 #if IS_ENABLED(CONFIG_UNICODE)
4557 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4558 {
4559 	const struct ext4_sb_encodings *encoding_info;
4560 	struct unicode_map *encoding;
4561 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4562 
4563 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4564 		return 0;
4565 
4566 	encoding_info = ext4_sb_read_encoding(es);
4567 	if (!encoding_info) {
4568 		ext4_msg(sb, KERN_ERR,
4569 			"Encoding requested by superblock is unknown");
4570 		return -EINVAL;
4571 	}
4572 
4573 	encoding = utf8_load(encoding_info->version);
4574 	if (IS_ERR(encoding)) {
4575 		ext4_msg(sb, KERN_ERR,
4576 			"can't mount with superblock charset: %s-%u.%u.%u "
4577 			"not supported by the kernel. flags: 0x%x.",
4578 			encoding_info->name,
4579 			unicode_major(encoding_info->version),
4580 			unicode_minor(encoding_info->version),
4581 			unicode_rev(encoding_info->version),
4582 			encoding_flags);
4583 		return -EINVAL;
4584 	}
4585 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4586 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4587 		unicode_major(encoding_info->version),
4588 		unicode_minor(encoding_info->version),
4589 		unicode_rev(encoding_info->version),
4590 		encoding_flags);
4591 
4592 	sb->s_encoding = encoding;
4593 	sb->s_encoding_flags = encoding_flags;
4594 
4595 	return 0;
4596 }
4597 #else
4598 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4599 {
4600 	return 0;
4601 }
4602 #endif
4603 
4604 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4605 {
4606 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4607 
4608 	/* Warn if metadata_csum and gdt_csum are both set. */
4609 	if (ext4_has_feature_metadata_csum(sb) &&
4610 	    ext4_has_feature_gdt_csum(sb))
4611 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4612 			     "redundant flags; please run fsck.");
4613 
4614 	/* Check for a known checksum algorithm */
4615 	if (!ext4_verify_csum_type(sb, es)) {
4616 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4617 			 "unknown checksum algorithm.");
4618 		return -EINVAL;
4619 	}
4620 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4621 				ext4_orphan_file_block_trigger);
4622 
4623 	/* Load the checksum driver */
4624 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4625 	if (IS_ERR(sbi->s_chksum_driver)) {
4626 		int ret = PTR_ERR(sbi->s_chksum_driver);
4627 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4628 		sbi->s_chksum_driver = NULL;
4629 		return ret;
4630 	}
4631 
4632 	/* Check superblock checksum */
4633 	if (!ext4_superblock_csum_verify(sb, es)) {
4634 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4635 			 "invalid superblock checksum.  Run e2fsck?");
4636 		return -EFSBADCRC;
4637 	}
4638 
4639 	/* Precompute checksum seed for all metadata */
4640 	if (ext4_has_feature_csum_seed(sb))
4641 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4642 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4643 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4644 					       sizeof(es->s_uuid));
4645 	return 0;
4646 }
4647 
4648 static int ext4_check_feature_compatibility(struct super_block *sb,
4649 					    struct ext4_super_block *es,
4650 					    int silent)
4651 {
4652 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4653 
4654 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4655 	    (ext4_has_compat_features(sb) ||
4656 	     ext4_has_ro_compat_features(sb) ||
4657 	     ext4_has_incompat_features(sb)))
4658 		ext4_msg(sb, KERN_WARNING,
4659 		       "feature flags set on rev 0 fs, "
4660 		       "running e2fsck is recommended");
4661 
4662 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4663 		set_opt2(sb, HURD_COMPAT);
4664 		if (ext4_has_feature_64bit(sb)) {
4665 			ext4_msg(sb, KERN_ERR,
4666 				 "The Hurd can't support 64-bit file systems");
4667 			return -EINVAL;
4668 		}
4669 
4670 		/*
4671 		 * ea_inode feature uses l_i_version field which is not
4672 		 * available in HURD_COMPAT mode.
4673 		 */
4674 		if (ext4_has_feature_ea_inode(sb)) {
4675 			ext4_msg(sb, KERN_ERR,
4676 				 "ea_inode feature is not supported for Hurd");
4677 			return -EINVAL;
4678 		}
4679 	}
4680 
4681 	if (IS_EXT2_SB(sb)) {
4682 		if (ext2_feature_set_ok(sb))
4683 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4684 				 "using the ext4 subsystem");
4685 		else {
4686 			/*
4687 			 * If we're probing be silent, if this looks like
4688 			 * it's actually an ext[34] filesystem.
4689 			 */
4690 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4691 				return -EINVAL;
4692 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4693 				 "to feature incompatibilities");
4694 			return -EINVAL;
4695 		}
4696 	}
4697 
4698 	if (IS_EXT3_SB(sb)) {
4699 		if (ext3_feature_set_ok(sb))
4700 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4701 				 "using the ext4 subsystem");
4702 		else {
4703 			/*
4704 			 * If we're probing be silent, if this looks like
4705 			 * it's actually an ext4 filesystem.
4706 			 */
4707 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4708 				return -EINVAL;
4709 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4710 				 "to feature incompatibilities");
4711 			return -EINVAL;
4712 		}
4713 	}
4714 
4715 	/*
4716 	 * Check feature flags regardless of the revision level, since we
4717 	 * previously didn't change the revision level when setting the flags,
4718 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4719 	 */
4720 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4721 		return -EINVAL;
4722 
4723 	if (sbi->s_daxdev) {
4724 		if (sb->s_blocksize == PAGE_SIZE)
4725 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4726 		else
4727 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4728 	}
4729 
4730 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4731 		if (ext4_has_feature_inline_data(sb)) {
4732 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4733 					" that may contain inline data");
4734 			return -EINVAL;
4735 		}
4736 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4737 			ext4_msg(sb, KERN_ERR,
4738 				"DAX unsupported by block device.");
4739 			return -EINVAL;
4740 		}
4741 	}
4742 
4743 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4744 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4745 			 es->s_encryption_level);
4746 		return -EINVAL;
4747 	}
4748 
4749 	return 0;
4750 }
4751 
4752 static int ext4_check_geometry(struct super_block *sb,
4753 			       struct ext4_super_block *es)
4754 {
4755 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4756 	__u64 blocks_count;
4757 	int err;
4758 
4759 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4760 		ext4_msg(sb, KERN_ERR,
4761 			 "Number of reserved GDT blocks insanely large: %d",
4762 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4763 		return -EINVAL;
4764 	}
4765 	/*
4766 	 * Test whether we have more sectors than will fit in sector_t,
4767 	 * and whether the max offset is addressable by the page cache.
4768 	 */
4769 	err = generic_check_addressable(sb->s_blocksize_bits,
4770 					ext4_blocks_count(es));
4771 	if (err) {
4772 		ext4_msg(sb, KERN_ERR, "filesystem"
4773 			 " too large to mount safely on this system");
4774 		return err;
4775 	}
4776 
4777 	/* check blocks count against device size */
4778 	blocks_count = sb_bdev_nr_blocks(sb);
4779 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4780 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4781 		       "exceeds size of device (%llu blocks)",
4782 		       ext4_blocks_count(es), blocks_count);
4783 		return -EINVAL;
4784 	}
4785 
4786 	/*
4787 	 * It makes no sense for the first data block to be beyond the end
4788 	 * of the filesystem.
4789 	 */
4790 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4791 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4792 			 "block %u is beyond end of filesystem (%llu)",
4793 			 le32_to_cpu(es->s_first_data_block),
4794 			 ext4_blocks_count(es));
4795 		return -EINVAL;
4796 	}
4797 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4798 	    (sbi->s_cluster_ratio == 1)) {
4799 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4800 			 "block is 0 with a 1k block and cluster size");
4801 		return -EINVAL;
4802 	}
4803 
4804 	blocks_count = (ext4_blocks_count(es) -
4805 			le32_to_cpu(es->s_first_data_block) +
4806 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4807 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4808 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4809 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4810 		       "(block count %llu, first data block %u, "
4811 		       "blocks per group %lu)", blocks_count,
4812 		       ext4_blocks_count(es),
4813 		       le32_to_cpu(es->s_first_data_block),
4814 		       EXT4_BLOCKS_PER_GROUP(sb));
4815 		return -EINVAL;
4816 	}
4817 	sbi->s_groups_count = blocks_count;
4818 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4819 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4820 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4821 	    le32_to_cpu(es->s_inodes_count)) {
4822 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4823 			 le32_to_cpu(es->s_inodes_count),
4824 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4825 		return -EINVAL;
4826 	}
4827 
4828 	return 0;
4829 }
4830 
4831 static int ext4_group_desc_init(struct super_block *sb,
4832 				struct ext4_super_block *es,
4833 				ext4_fsblk_t logical_sb_block,
4834 				ext4_group_t *first_not_zeroed)
4835 {
4836 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4837 	unsigned int db_count;
4838 	ext4_fsblk_t block;
4839 	int i;
4840 
4841 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4842 		   EXT4_DESC_PER_BLOCK(sb);
4843 	if (ext4_has_feature_meta_bg(sb)) {
4844 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4845 			ext4_msg(sb, KERN_WARNING,
4846 				 "first meta block group too large: %u "
4847 				 "(group descriptor block count %u)",
4848 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4849 			return -EINVAL;
4850 		}
4851 	}
4852 	rcu_assign_pointer(sbi->s_group_desc,
4853 			   kvmalloc_array(db_count,
4854 					  sizeof(struct buffer_head *),
4855 					  GFP_KERNEL));
4856 	if (sbi->s_group_desc == NULL) {
4857 		ext4_msg(sb, KERN_ERR, "not enough memory");
4858 		return -ENOMEM;
4859 	}
4860 
4861 	bgl_lock_init(sbi->s_blockgroup_lock);
4862 
4863 	/* Pre-read the descriptors into the buffer cache */
4864 	for (i = 0; i < db_count; i++) {
4865 		block = descriptor_loc(sb, logical_sb_block, i);
4866 		ext4_sb_breadahead_unmovable(sb, block);
4867 	}
4868 
4869 	for (i = 0; i < db_count; i++) {
4870 		struct buffer_head *bh;
4871 
4872 		block = descriptor_loc(sb, logical_sb_block, i);
4873 		bh = ext4_sb_bread_unmovable(sb, block);
4874 		if (IS_ERR(bh)) {
4875 			ext4_msg(sb, KERN_ERR,
4876 			       "can't read group descriptor %d", i);
4877 			sbi->s_gdb_count = i;
4878 			return PTR_ERR(bh);
4879 		}
4880 		rcu_read_lock();
4881 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4882 		rcu_read_unlock();
4883 	}
4884 	sbi->s_gdb_count = db_count;
4885 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4886 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4887 		return -EFSCORRUPTED;
4888 	}
4889 
4890 	return 0;
4891 }
4892 
4893 static int ext4_load_and_init_journal(struct super_block *sb,
4894 				      struct ext4_super_block *es,
4895 				      struct ext4_fs_context *ctx)
4896 {
4897 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4898 	int err;
4899 
4900 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4901 	if (err)
4902 		return err;
4903 
4904 	if (ext4_has_feature_64bit(sb) &&
4905 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4906 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4907 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4908 		goto out;
4909 	}
4910 
4911 	if (!set_journal_csum_feature_set(sb)) {
4912 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4913 			 "feature set");
4914 		goto out;
4915 	}
4916 
4917 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4918 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4919 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4920 		ext4_msg(sb, KERN_ERR,
4921 			"Failed to set fast commit journal feature");
4922 		goto out;
4923 	}
4924 
4925 	/* We have now updated the journal if required, so we can
4926 	 * validate the data journaling mode. */
4927 	switch (test_opt(sb, DATA_FLAGS)) {
4928 	case 0:
4929 		/* No mode set, assume a default based on the journal
4930 		 * capabilities: ORDERED_DATA if the journal can
4931 		 * cope, else JOURNAL_DATA
4932 		 */
4933 		if (jbd2_journal_check_available_features
4934 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4935 			set_opt(sb, ORDERED_DATA);
4936 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4937 		} else {
4938 			set_opt(sb, JOURNAL_DATA);
4939 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4940 		}
4941 		break;
4942 
4943 	case EXT4_MOUNT_ORDERED_DATA:
4944 	case EXT4_MOUNT_WRITEBACK_DATA:
4945 		if (!jbd2_journal_check_available_features
4946 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4947 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4948 			       "requested data journaling mode");
4949 			goto out;
4950 		}
4951 		break;
4952 	default:
4953 		break;
4954 	}
4955 
4956 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4957 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4958 		ext4_msg(sb, KERN_ERR, "can't mount with "
4959 			"journal_async_commit in data=ordered mode");
4960 		goto out;
4961 	}
4962 
4963 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4964 
4965 	sbi->s_journal->j_submit_inode_data_buffers =
4966 		ext4_journal_submit_inode_data_buffers;
4967 	sbi->s_journal->j_finish_inode_data_buffers =
4968 		ext4_journal_finish_inode_data_buffers;
4969 
4970 	return 0;
4971 
4972 out:
4973 	/* flush s_error_work before journal destroy. */
4974 	flush_work(&sbi->s_error_work);
4975 	jbd2_journal_destroy(sbi->s_journal);
4976 	sbi->s_journal = NULL;
4977 	return -EINVAL;
4978 }
4979 
4980 static int ext4_check_journal_data_mode(struct super_block *sb)
4981 {
4982 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4983 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4984 			    "data=journal disables delayed allocation, "
4985 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4986 		/* can't mount with both data=journal and dioread_nolock. */
4987 		clear_opt(sb, DIOREAD_NOLOCK);
4988 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4989 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4990 			ext4_msg(sb, KERN_ERR, "can't mount with "
4991 				 "both data=journal and delalloc");
4992 			return -EINVAL;
4993 		}
4994 		if (test_opt(sb, DAX_ALWAYS)) {
4995 			ext4_msg(sb, KERN_ERR, "can't mount with "
4996 				 "both data=journal and dax");
4997 			return -EINVAL;
4998 		}
4999 		if (ext4_has_feature_encrypt(sb)) {
5000 			ext4_msg(sb, KERN_WARNING,
5001 				 "encrypted files will use data=ordered "
5002 				 "instead of data journaling mode");
5003 		}
5004 		if (test_opt(sb, DELALLOC))
5005 			clear_opt(sb, DELALLOC);
5006 	} else {
5007 		sb->s_iflags |= SB_I_CGROUPWB;
5008 	}
5009 
5010 	return 0;
5011 }
5012 
5013 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5014 			   int silent)
5015 {
5016 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5017 	struct ext4_super_block *es;
5018 	ext4_fsblk_t logical_sb_block;
5019 	unsigned long offset = 0;
5020 	struct buffer_head *bh;
5021 	int ret = -EINVAL;
5022 	int blocksize;
5023 
5024 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5025 	if (!blocksize) {
5026 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5027 		return -EINVAL;
5028 	}
5029 
5030 	/*
5031 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5032 	 * block sizes.  We need to calculate the offset from buffer start.
5033 	 */
5034 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5035 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5036 		offset = do_div(logical_sb_block, blocksize);
5037 	} else {
5038 		logical_sb_block = sbi->s_sb_block;
5039 	}
5040 
5041 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5042 	if (IS_ERR(bh)) {
5043 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5044 		return PTR_ERR(bh);
5045 	}
5046 	/*
5047 	 * Note: s_es must be initialized as soon as possible because
5048 	 *       some ext4 macro-instructions depend on its value
5049 	 */
5050 	es = (struct ext4_super_block *) (bh->b_data + offset);
5051 	sbi->s_es = es;
5052 	sb->s_magic = le16_to_cpu(es->s_magic);
5053 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5054 		if (!silent)
5055 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5056 		goto out;
5057 	}
5058 
5059 	if (le32_to_cpu(es->s_log_block_size) >
5060 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5061 		ext4_msg(sb, KERN_ERR,
5062 			 "Invalid log block size: %u",
5063 			 le32_to_cpu(es->s_log_block_size));
5064 		goto out;
5065 	}
5066 	if (le32_to_cpu(es->s_log_cluster_size) >
5067 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5068 		ext4_msg(sb, KERN_ERR,
5069 			 "Invalid log cluster size: %u",
5070 			 le32_to_cpu(es->s_log_cluster_size));
5071 		goto out;
5072 	}
5073 
5074 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5075 
5076 	/*
5077 	 * If the default block size is not the same as the real block size,
5078 	 * we need to reload it.
5079 	 */
5080 	if (sb->s_blocksize == blocksize) {
5081 		*lsb = logical_sb_block;
5082 		sbi->s_sbh = bh;
5083 		return 0;
5084 	}
5085 
5086 	/*
5087 	 * bh must be released before kill_bdev(), otherwise
5088 	 * it won't be freed and its page also. kill_bdev()
5089 	 * is called by sb_set_blocksize().
5090 	 */
5091 	brelse(bh);
5092 	/* Validate the filesystem blocksize */
5093 	if (!sb_set_blocksize(sb, blocksize)) {
5094 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5095 				blocksize);
5096 		bh = NULL;
5097 		goto out;
5098 	}
5099 
5100 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5101 	offset = do_div(logical_sb_block, blocksize);
5102 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5103 	if (IS_ERR(bh)) {
5104 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5105 		ret = PTR_ERR(bh);
5106 		bh = NULL;
5107 		goto out;
5108 	}
5109 	es = (struct ext4_super_block *)(bh->b_data + offset);
5110 	sbi->s_es = es;
5111 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5112 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5113 		goto out;
5114 	}
5115 	*lsb = logical_sb_block;
5116 	sbi->s_sbh = bh;
5117 	return 0;
5118 out:
5119 	brelse(bh);
5120 	return ret;
5121 }
5122 
5123 static void ext4_hash_info_init(struct super_block *sb)
5124 {
5125 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5126 	struct ext4_super_block *es = sbi->s_es;
5127 	unsigned int i;
5128 
5129 	for (i = 0; i < 4; i++)
5130 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5131 
5132 	sbi->s_def_hash_version = es->s_def_hash_version;
5133 	if (ext4_has_feature_dir_index(sb)) {
5134 		i = le32_to_cpu(es->s_flags);
5135 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5136 			sbi->s_hash_unsigned = 3;
5137 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5138 #ifdef __CHAR_UNSIGNED__
5139 			if (!sb_rdonly(sb))
5140 				es->s_flags |=
5141 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5142 			sbi->s_hash_unsigned = 3;
5143 #else
5144 			if (!sb_rdonly(sb))
5145 				es->s_flags |=
5146 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5147 #endif
5148 		}
5149 	}
5150 }
5151 
5152 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5153 {
5154 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5155 	struct ext4_super_block *es = sbi->s_es;
5156 	int has_huge_files;
5157 
5158 	has_huge_files = ext4_has_feature_huge_file(sb);
5159 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5160 						      has_huge_files);
5161 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5162 
5163 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5164 	if (ext4_has_feature_64bit(sb)) {
5165 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5166 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5167 		    !is_power_of_2(sbi->s_desc_size)) {
5168 			ext4_msg(sb, KERN_ERR,
5169 			       "unsupported descriptor size %lu",
5170 			       sbi->s_desc_size);
5171 			return -EINVAL;
5172 		}
5173 	} else
5174 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5175 
5176 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5177 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5178 
5179 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5180 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5181 		if (!silent)
5182 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5183 		return -EINVAL;
5184 	}
5185 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5186 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5187 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5188 			 sbi->s_inodes_per_group);
5189 		return -EINVAL;
5190 	}
5191 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5192 					sbi->s_inodes_per_block;
5193 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5194 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5195 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5196 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5197 
5198 	return 0;
5199 }
5200 
5201 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5202 {
5203 	struct ext4_super_block *es = NULL;
5204 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5205 	ext4_fsblk_t logical_sb_block;
5206 	struct inode *root;
5207 	int needs_recovery;
5208 	int err;
5209 	ext4_group_t first_not_zeroed;
5210 	struct ext4_fs_context *ctx = fc->fs_private;
5211 	int silent = fc->sb_flags & SB_SILENT;
5212 
5213 	/* Set defaults for the variables that will be set during parsing */
5214 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5215 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5216 
5217 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5218 	sbi->s_sectors_written_start =
5219 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5220 
5221 	err = ext4_load_super(sb, &logical_sb_block, silent);
5222 	if (err)
5223 		goto out_fail;
5224 
5225 	es = sbi->s_es;
5226 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5227 
5228 	err = ext4_init_metadata_csum(sb, es);
5229 	if (err)
5230 		goto failed_mount;
5231 
5232 	ext4_set_def_opts(sb, es);
5233 
5234 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5235 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5236 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5237 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5238 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5239 
5240 	/*
5241 	 * set default s_li_wait_mult for lazyinit, for the case there is
5242 	 * no mount option specified.
5243 	 */
5244 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5245 
5246 	err = ext4_inode_info_init(sb, es);
5247 	if (err)
5248 		goto failed_mount;
5249 
5250 	err = parse_apply_sb_mount_options(sb, ctx);
5251 	if (err < 0)
5252 		goto failed_mount;
5253 
5254 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5255 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5256 
5257 	err = ext4_check_opt_consistency(fc, sb);
5258 	if (err < 0)
5259 		goto failed_mount;
5260 
5261 	ext4_apply_options(fc, sb);
5262 
5263 	err = ext4_encoding_init(sb, es);
5264 	if (err)
5265 		goto failed_mount;
5266 
5267 	err = ext4_check_journal_data_mode(sb);
5268 	if (err)
5269 		goto failed_mount;
5270 
5271 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5272 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5273 
5274 	/* i_version is always enabled now */
5275 	sb->s_flags |= SB_I_VERSION;
5276 
5277 	err = ext4_check_feature_compatibility(sb, es, silent);
5278 	if (err)
5279 		goto failed_mount;
5280 
5281 	err = ext4_block_group_meta_init(sb, silent);
5282 	if (err)
5283 		goto failed_mount;
5284 
5285 	ext4_hash_info_init(sb);
5286 
5287 	err = ext4_handle_clustersize(sb);
5288 	if (err)
5289 		goto failed_mount;
5290 
5291 	err = ext4_check_geometry(sb, es);
5292 	if (err)
5293 		goto failed_mount;
5294 
5295 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5296 	spin_lock_init(&sbi->s_error_lock);
5297 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5298 
5299 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5300 	if (err)
5301 		goto failed_mount3;
5302 
5303 	err = ext4_es_register_shrinker(sbi);
5304 	if (err)
5305 		goto failed_mount3;
5306 
5307 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5308 	/*
5309 	 * It's hard to get stripe aligned blocks if stripe is not aligned with
5310 	 * cluster, just disable stripe and alert user to simpfy code and avoid
5311 	 * stripe aligned allocation which will rarely successes.
5312 	 */
5313 	if (sbi->s_stripe > 0 && sbi->s_cluster_ratio > 1 &&
5314 	    sbi->s_stripe % sbi->s_cluster_ratio != 0) {
5315 		ext4_msg(sb, KERN_WARNING,
5316 			 "stripe (%lu) is not aligned with cluster size (%u), "
5317 			 "stripe is disabled",
5318 			 sbi->s_stripe, sbi->s_cluster_ratio);
5319 		sbi->s_stripe = 0;
5320 	}
5321 	sbi->s_extent_max_zeroout_kb = 32;
5322 
5323 	/*
5324 	 * set up enough so that it can read an inode
5325 	 */
5326 	sb->s_op = &ext4_sops;
5327 	sb->s_export_op = &ext4_export_ops;
5328 	sb->s_xattr = ext4_xattr_handlers;
5329 #ifdef CONFIG_FS_ENCRYPTION
5330 	sb->s_cop = &ext4_cryptops;
5331 #endif
5332 #ifdef CONFIG_FS_VERITY
5333 	sb->s_vop = &ext4_verityops;
5334 #endif
5335 #ifdef CONFIG_QUOTA
5336 	sb->dq_op = &ext4_quota_operations;
5337 	if (ext4_has_feature_quota(sb))
5338 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5339 	else
5340 		sb->s_qcop = &ext4_qctl_operations;
5341 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5342 #endif
5343 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5344 
5345 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5346 	mutex_init(&sbi->s_orphan_lock);
5347 
5348 	ext4_fast_commit_init(sb);
5349 
5350 	sb->s_root = NULL;
5351 
5352 	needs_recovery = (es->s_last_orphan != 0 ||
5353 			  ext4_has_feature_orphan_present(sb) ||
5354 			  ext4_has_feature_journal_needs_recovery(sb));
5355 
5356 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5357 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5358 		if (err)
5359 			goto failed_mount3a;
5360 	}
5361 
5362 	err = -EINVAL;
5363 	/*
5364 	 * The first inode we look at is the journal inode.  Don't try
5365 	 * root first: it may be modified in the journal!
5366 	 */
5367 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5368 		err = ext4_load_and_init_journal(sb, es, ctx);
5369 		if (err)
5370 			goto failed_mount3a;
5371 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5372 		   ext4_has_feature_journal_needs_recovery(sb)) {
5373 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5374 		       "suppressed and not mounted read-only");
5375 		goto failed_mount3a;
5376 	} else {
5377 		/* Nojournal mode, all journal mount options are illegal */
5378 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5379 			ext4_msg(sb, KERN_ERR, "can't mount with "
5380 				 "journal_async_commit, fs mounted w/o journal");
5381 			goto failed_mount3a;
5382 		}
5383 
5384 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5385 			ext4_msg(sb, KERN_ERR, "can't mount with "
5386 				 "journal_checksum, fs mounted w/o journal");
5387 			goto failed_mount3a;
5388 		}
5389 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5390 			ext4_msg(sb, KERN_ERR, "can't mount with "
5391 				 "commit=%lu, fs mounted w/o journal",
5392 				 sbi->s_commit_interval / HZ);
5393 			goto failed_mount3a;
5394 		}
5395 		if (EXT4_MOUNT_DATA_FLAGS &
5396 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5397 			ext4_msg(sb, KERN_ERR, "can't mount with "
5398 				 "data=, fs mounted w/o journal");
5399 			goto failed_mount3a;
5400 		}
5401 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5402 		clear_opt(sb, JOURNAL_CHECKSUM);
5403 		clear_opt(sb, DATA_FLAGS);
5404 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5405 		sbi->s_journal = NULL;
5406 		needs_recovery = 0;
5407 	}
5408 
5409 	if (!test_opt(sb, NO_MBCACHE)) {
5410 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5411 		if (!sbi->s_ea_block_cache) {
5412 			ext4_msg(sb, KERN_ERR,
5413 				 "Failed to create ea_block_cache");
5414 			err = -EINVAL;
5415 			goto failed_mount_wq;
5416 		}
5417 
5418 		if (ext4_has_feature_ea_inode(sb)) {
5419 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5420 			if (!sbi->s_ea_inode_cache) {
5421 				ext4_msg(sb, KERN_ERR,
5422 					 "Failed to create ea_inode_cache");
5423 				err = -EINVAL;
5424 				goto failed_mount_wq;
5425 			}
5426 		}
5427 	}
5428 
5429 	/*
5430 	 * Get the # of file system overhead blocks from the
5431 	 * superblock if present.
5432 	 */
5433 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5434 	/* ignore the precalculated value if it is ridiculous */
5435 	if (sbi->s_overhead > ext4_blocks_count(es))
5436 		sbi->s_overhead = 0;
5437 	/*
5438 	 * If the bigalloc feature is not enabled recalculating the
5439 	 * overhead doesn't take long, so we might as well just redo
5440 	 * it to make sure we are using the correct value.
5441 	 */
5442 	if (!ext4_has_feature_bigalloc(sb))
5443 		sbi->s_overhead = 0;
5444 	if (sbi->s_overhead == 0) {
5445 		err = ext4_calculate_overhead(sb);
5446 		if (err)
5447 			goto failed_mount_wq;
5448 	}
5449 
5450 	/*
5451 	 * The maximum number of concurrent works can be high and
5452 	 * concurrency isn't really necessary.  Limit it to 1.
5453 	 */
5454 	EXT4_SB(sb)->rsv_conversion_wq =
5455 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5456 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5457 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5458 		err = -ENOMEM;
5459 		goto failed_mount4;
5460 	}
5461 
5462 	/*
5463 	 * The jbd2_journal_load will have done any necessary log recovery,
5464 	 * so we can safely mount the rest of the filesystem now.
5465 	 */
5466 
5467 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5468 	if (IS_ERR(root)) {
5469 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5470 		err = PTR_ERR(root);
5471 		root = NULL;
5472 		goto failed_mount4;
5473 	}
5474 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5475 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5476 		iput(root);
5477 		err = -EFSCORRUPTED;
5478 		goto failed_mount4;
5479 	}
5480 
5481 	sb->s_root = d_make_root(root);
5482 	if (!sb->s_root) {
5483 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5484 		err = -ENOMEM;
5485 		goto failed_mount4;
5486 	}
5487 
5488 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5489 	if (err == -EROFS) {
5490 		sb->s_flags |= SB_RDONLY;
5491 	} else if (err)
5492 		goto failed_mount4a;
5493 
5494 	ext4_set_resv_clusters(sb);
5495 
5496 	if (test_opt(sb, BLOCK_VALIDITY)) {
5497 		err = ext4_setup_system_zone(sb);
5498 		if (err) {
5499 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5500 				 "zone (%d)", err);
5501 			goto failed_mount4a;
5502 		}
5503 	}
5504 	ext4_fc_replay_cleanup(sb);
5505 
5506 	ext4_ext_init(sb);
5507 
5508 	/*
5509 	 * Enable optimize_scan if number of groups is > threshold. This can be
5510 	 * turned off by passing "mb_optimize_scan=0". This can also be
5511 	 * turned on forcefully by passing "mb_optimize_scan=1".
5512 	 */
5513 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5514 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5515 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5516 		else
5517 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5518 	}
5519 
5520 	err = ext4_mb_init(sb);
5521 	if (err) {
5522 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5523 			 err);
5524 		goto failed_mount5;
5525 	}
5526 
5527 	/*
5528 	 * We can only set up the journal commit callback once
5529 	 * mballoc is initialized
5530 	 */
5531 	if (sbi->s_journal)
5532 		sbi->s_journal->j_commit_callback =
5533 			ext4_journal_commit_callback;
5534 
5535 	err = ext4_percpu_param_init(sbi);
5536 	if (err)
5537 		goto failed_mount6;
5538 
5539 	if (ext4_has_feature_flex_bg(sb))
5540 		if (!ext4_fill_flex_info(sb)) {
5541 			ext4_msg(sb, KERN_ERR,
5542 			       "unable to initialize "
5543 			       "flex_bg meta info!");
5544 			err = -ENOMEM;
5545 			goto failed_mount6;
5546 		}
5547 
5548 	err = ext4_register_li_request(sb, first_not_zeroed);
5549 	if (err)
5550 		goto failed_mount6;
5551 
5552 	err = ext4_register_sysfs(sb);
5553 	if (err)
5554 		goto failed_mount7;
5555 
5556 	err = ext4_init_orphan_info(sb);
5557 	if (err)
5558 		goto failed_mount8;
5559 #ifdef CONFIG_QUOTA
5560 	/* Enable quota usage during mount. */
5561 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5562 		err = ext4_enable_quotas(sb);
5563 		if (err)
5564 			goto failed_mount9;
5565 	}
5566 #endif  /* CONFIG_QUOTA */
5567 
5568 	/*
5569 	 * Save the original bdev mapping's wb_err value which could be
5570 	 * used to detect the metadata async write error.
5571 	 */
5572 	spin_lock_init(&sbi->s_bdev_wb_lock);
5573 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5574 				 &sbi->s_bdev_wb_err);
5575 	sb->s_bdev->bd_super = sb;
5576 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5577 	ext4_orphan_cleanup(sb, es);
5578 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5579 	/*
5580 	 * Update the checksum after updating free space/inode counters and
5581 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5582 	 * checksum in the buffer cache until it is written out and
5583 	 * e2fsprogs programs trying to open a file system immediately
5584 	 * after it is mounted can fail.
5585 	 */
5586 	ext4_superblock_csum_set(sb);
5587 	if (needs_recovery) {
5588 		ext4_msg(sb, KERN_INFO, "recovery complete");
5589 		err = ext4_mark_recovery_complete(sb, es);
5590 		if (err)
5591 			goto failed_mount10;
5592 	}
5593 
5594 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5595 		ext4_msg(sb, KERN_WARNING,
5596 			 "mounting with \"discard\" option, but the device does not support discard");
5597 
5598 	if (es->s_error_count)
5599 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5600 
5601 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5602 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5603 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5604 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5605 	atomic_set(&sbi->s_warning_count, 0);
5606 	atomic_set(&sbi->s_msg_count, 0);
5607 
5608 	return 0;
5609 
5610 failed_mount10:
5611 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5612 failed_mount9: __maybe_unused
5613 	ext4_release_orphan_info(sb);
5614 failed_mount8:
5615 	ext4_unregister_sysfs(sb);
5616 	kobject_put(&sbi->s_kobj);
5617 failed_mount7:
5618 	ext4_unregister_li_request(sb);
5619 failed_mount6:
5620 	ext4_mb_release(sb);
5621 	ext4_flex_groups_free(sbi);
5622 	ext4_percpu_param_destroy(sbi);
5623 failed_mount5:
5624 	ext4_ext_release(sb);
5625 	ext4_release_system_zone(sb);
5626 failed_mount4a:
5627 	dput(sb->s_root);
5628 	sb->s_root = NULL;
5629 failed_mount4:
5630 	ext4_msg(sb, KERN_ERR, "mount failed");
5631 	if (EXT4_SB(sb)->rsv_conversion_wq)
5632 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5633 failed_mount_wq:
5634 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5635 	sbi->s_ea_inode_cache = NULL;
5636 
5637 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5638 	sbi->s_ea_block_cache = NULL;
5639 
5640 	if (sbi->s_journal) {
5641 		/* flush s_error_work before journal destroy. */
5642 		flush_work(&sbi->s_error_work);
5643 		jbd2_journal_destroy(sbi->s_journal);
5644 		sbi->s_journal = NULL;
5645 	}
5646 failed_mount3a:
5647 	ext4_es_unregister_shrinker(sbi);
5648 failed_mount3:
5649 	/* flush s_error_work before sbi destroy */
5650 	flush_work(&sbi->s_error_work);
5651 	del_timer_sync(&sbi->s_err_report);
5652 	ext4_stop_mmpd(sbi);
5653 	ext4_group_desc_free(sbi);
5654 failed_mount:
5655 	if (sbi->s_chksum_driver)
5656 		crypto_free_shash(sbi->s_chksum_driver);
5657 
5658 #if IS_ENABLED(CONFIG_UNICODE)
5659 	utf8_unload(sb->s_encoding);
5660 #endif
5661 
5662 #ifdef CONFIG_QUOTA
5663 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5664 		kfree(get_qf_name(sb, sbi, i));
5665 #endif
5666 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5667 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5668 	brelse(sbi->s_sbh);
5669 	ext4_blkdev_remove(sbi);
5670 out_fail:
5671 	invalidate_bdev(sb->s_bdev);
5672 	sb->s_fs_info = NULL;
5673 	return err;
5674 }
5675 
5676 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5677 {
5678 	struct ext4_fs_context *ctx = fc->fs_private;
5679 	struct ext4_sb_info *sbi;
5680 	const char *descr;
5681 	int ret;
5682 
5683 	sbi = ext4_alloc_sbi(sb);
5684 	if (!sbi)
5685 		return -ENOMEM;
5686 
5687 	fc->s_fs_info = sbi;
5688 
5689 	/* Cleanup superblock name */
5690 	strreplace(sb->s_id, '/', '!');
5691 
5692 	sbi->s_sb_block = 1;	/* Default super block location */
5693 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5694 		sbi->s_sb_block = ctx->s_sb_block;
5695 
5696 	ret = __ext4_fill_super(fc, sb);
5697 	if (ret < 0)
5698 		goto free_sbi;
5699 
5700 	if (sbi->s_journal) {
5701 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5702 			descr = " journalled data mode";
5703 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5704 			descr = " ordered data mode";
5705 		else
5706 			descr = " writeback data mode";
5707 	} else
5708 		descr = "out journal";
5709 
5710 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5711 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5712 			 "Quota mode: %s.", &sb->s_uuid,
5713 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5714 			 ext4_quota_mode(sb));
5715 
5716 	/* Update the s_overhead_clusters if necessary */
5717 	ext4_update_overhead(sb, false);
5718 	return 0;
5719 
5720 free_sbi:
5721 	ext4_free_sbi(sbi);
5722 	fc->s_fs_info = NULL;
5723 	return ret;
5724 }
5725 
5726 static int ext4_get_tree(struct fs_context *fc)
5727 {
5728 	return get_tree_bdev(fc, ext4_fill_super);
5729 }
5730 
5731 /*
5732  * Setup any per-fs journal parameters now.  We'll do this both on
5733  * initial mount, once the journal has been initialised but before we've
5734  * done any recovery; and again on any subsequent remount.
5735  */
5736 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5737 {
5738 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5739 
5740 	journal->j_commit_interval = sbi->s_commit_interval;
5741 	journal->j_min_batch_time = sbi->s_min_batch_time;
5742 	journal->j_max_batch_time = sbi->s_max_batch_time;
5743 	ext4_fc_init(sb, journal);
5744 
5745 	write_lock(&journal->j_state_lock);
5746 	if (test_opt(sb, BARRIER))
5747 		journal->j_flags |= JBD2_BARRIER;
5748 	else
5749 		journal->j_flags &= ~JBD2_BARRIER;
5750 	if (test_opt(sb, DATA_ERR_ABORT))
5751 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5752 	else
5753 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5754 	/*
5755 	 * Always enable journal cycle record option, letting the journal
5756 	 * records log transactions continuously between each mount.
5757 	 */
5758 	journal->j_flags |= JBD2_CYCLE_RECORD;
5759 	write_unlock(&journal->j_state_lock);
5760 }
5761 
5762 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5763 					     unsigned int journal_inum)
5764 {
5765 	struct inode *journal_inode;
5766 
5767 	/*
5768 	 * Test for the existence of a valid inode on disk.  Bad things
5769 	 * happen if we iget() an unused inode, as the subsequent iput()
5770 	 * will try to delete it.
5771 	 */
5772 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5773 	if (IS_ERR(journal_inode)) {
5774 		ext4_msg(sb, KERN_ERR, "no journal found");
5775 		return NULL;
5776 	}
5777 	if (!journal_inode->i_nlink) {
5778 		make_bad_inode(journal_inode);
5779 		iput(journal_inode);
5780 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5781 		return NULL;
5782 	}
5783 
5784 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5785 		  journal_inode, journal_inode->i_size);
5786 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5787 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5788 		iput(journal_inode);
5789 		return NULL;
5790 	}
5791 	return journal_inode;
5792 }
5793 
5794 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5795 {
5796 	struct ext4_map_blocks map;
5797 	int ret;
5798 
5799 	if (journal->j_inode == NULL)
5800 		return 0;
5801 
5802 	map.m_lblk = *block;
5803 	map.m_len = 1;
5804 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5805 	if (ret <= 0) {
5806 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5807 			 "journal bmap failed: block %llu ret %d\n",
5808 			 *block, ret);
5809 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5810 		return ret;
5811 	}
5812 	*block = map.m_pblk;
5813 	return 0;
5814 }
5815 
5816 static journal_t *ext4_get_journal(struct super_block *sb,
5817 				   unsigned int journal_inum)
5818 {
5819 	struct inode *journal_inode;
5820 	journal_t *journal;
5821 
5822 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5823 		return NULL;
5824 
5825 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5826 	if (!journal_inode)
5827 		return NULL;
5828 
5829 	journal = jbd2_journal_init_inode(journal_inode);
5830 	if (!journal) {
5831 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5832 		iput(journal_inode);
5833 		return NULL;
5834 	}
5835 	journal->j_private = sb;
5836 	journal->j_bmap = ext4_journal_bmap;
5837 	ext4_init_journal_params(sb, journal);
5838 	return journal;
5839 }
5840 
5841 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5842 				       dev_t j_dev)
5843 {
5844 	struct buffer_head *bh;
5845 	journal_t *journal;
5846 	ext4_fsblk_t start;
5847 	ext4_fsblk_t len;
5848 	int hblock, blocksize;
5849 	ext4_fsblk_t sb_block;
5850 	unsigned long offset;
5851 	struct ext4_super_block *es;
5852 	struct block_device *bdev;
5853 
5854 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5855 		return NULL;
5856 
5857 	bdev = ext4_blkdev_get(j_dev, sb);
5858 	if (bdev == NULL)
5859 		return NULL;
5860 
5861 	blocksize = sb->s_blocksize;
5862 	hblock = bdev_logical_block_size(bdev);
5863 	if (blocksize < hblock) {
5864 		ext4_msg(sb, KERN_ERR,
5865 			"blocksize too small for journal device");
5866 		goto out_bdev;
5867 	}
5868 
5869 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5870 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5871 	set_blocksize(bdev, blocksize);
5872 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5873 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5874 		       "external journal");
5875 		goto out_bdev;
5876 	}
5877 
5878 	es = (struct ext4_super_block *) (bh->b_data + offset);
5879 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5880 	    !(le32_to_cpu(es->s_feature_incompat) &
5881 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5882 		ext4_msg(sb, KERN_ERR, "external journal has "
5883 					"bad superblock");
5884 		brelse(bh);
5885 		goto out_bdev;
5886 	}
5887 
5888 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5889 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5890 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5891 		ext4_msg(sb, KERN_ERR, "external journal has "
5892 				       "corrupt superblock");
5893 		brelse(bh);
5894 		goto out_bdev;
5895 	}
5896 
5897 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5898 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5899 		brelse(bh);
5900 		goto out_bdev;
5901 	}
5902 
5903 	len = ext4_blocks_count(es);
5904 	start = sb_block + 1;
5905 	brelse(bh);	/* we're done with the superblock */
5906 
5907 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5908 					start, len, blocksize);
5909 	if (!journal) {
5910 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5911 		goto out_bdev;
5912 	}
5913 	journal->j_private = sb;
5914 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5915 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5916 		goto out_journal;
5917 	}
5918 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5919 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5920 					"user (unsupported) - %d",
5921 			be32_to_cpu(journal->j_superblock->s_nr_users));
5922 		goto out_journal;
5923 	}
5924 	EXT4_SB(sb)->s_journal_bdev = bdev;
5925 	ext4_init_journal_params(sb, journal);
5926 	return journal;
5927 
5928 out_journal:
5929 	jbd2_journal_destroy(journal);
5930 out_bdev:
5931 	blkdev_put(bdev, sb);
5932 	return NULL;
5933 }
5934 
5935 static int ext4_load_journal(struct super_block *sb,
5936 			     struct ext4_super_block *es,
5937 			     unsigned long journal_devnum)
5938 {
5939 	journal_t *journal;
5940 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5941 	dev_t journal_dev;
5942 	int err = 0;
5943 	int really_read_only;
5944 	int journal_dev_ro;
5945 
5946 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5947 		return -EFSCORRUPTED;
5948 
5949 	if (journal_devnum &&
5950 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5951 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5952 			"numbers have changed");
5953 		journal_dev = new_decode_dev(journal_devnum);
5954 	} else
5955 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5956 
5957 	if (journal_inum && journal_dev) {
5958 		ext4_msg(sb, KERN_ERR,
5959 			 "filesystem has both journal inode and journal device!");
5960 		return -EINVAL;
5961 	}
5962 
5963 	if (journal_inum) {
5964 		journal = ext4_get_journal(sb, journal_inum);
5965 		if (!journal)
5966 			return -EINVAL;
5967 	} else {
5968 		journal = ext4_get_dev_journal(sb, journal_dev);
5969 		if (!journal)
5970 			return -EINVAL;
5971 	}
5972 
5973 	journal_dev_ro = bdev_read_only(journal->j_dev);
5974 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5975 
5976 	if (journal_dev_ro && !sb_rdonly(sb)) {
5977 		ext4_msg(sb, KERN_ERR,
5978 			 "journal device read-only, try mounting with '-o ro'");
5979 		err = -EROFS;
5980 		goto err_out;
5981 	}
5982 
5983 	/*
5984 	 * Are we loading a blank journal or performing recovery after a
5985 	 * crash?  For recovery, we need to check in advance whether we
5986 	 * can get read-write access to the device.
5987 	 */
5988 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5989 		if (sb_rdonly(sb)) {
5990 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5991 					"required on readonly filesystem");
5992 			if (really_read_only) {
5993 				ext4_msg(sb, KERN_ERR, "write access "
5994 					"unavailable, cannot proceed "
5995 					"(try mounting with noload)");
5996 				err = -EROFS;
5997 				goto err_out;
5998 			}
5999 			ext4_msg(sb, KERN_INFO, "write access will "
6000 			       "be enabled during recovery");
6001 		}
6002 	}
6003 
6004 	if (!(journal->j_flags & JBD2_BARRIER))
6005 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6006 
6007 	if (!ext4_has_feature_journal_needs_recovery(sb))
6008 		err = jbd2_journal_wipe(journal, !really_read_only);
6009 	if (!err) {
6010 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6011 		__le16 orig_state;
6012 		bool changed = false;
6013 
6014 		if (save)
6015 			memcpy(save, ((char *) es) +
6016 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6017 		err = jbd2_journal_load(journal);
6018 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6019 				   save, EXT4_S_ERR_LEN)) {
6020 			memcpy(((char *) es) + EXT4_S_ERR_START,
6021 			       save, EXT4_S_ERR_LEN);
6022 			changed = true;
6023 		}
6024 		kfree(save);
6025 		orig_state = es->s_state;
6026 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6027 					   EXT4_ERROR_FS);
6028 		if (orig_state != es->s_state)
6029 			changed = true;
6030 		/* Write out restored error information to the superblock */
6031 		if (changed && !really_read_only) {
6032 			int err2;
6033 			err2 = ext4_commit_super(sb);
6034 			err = err ? : err2;
6035 		}
6036 	}
6037 
6038 	if (err) {
6039 		ext4_msg(sb, KERN_ERR, "error loading journal");
6040 		goto err_out;
6041 	}
6042 
6043 	EXT4_SB(sb)->s_journal = journal;
6044 	err = ext4_clear_journal_err(sb, es);
6045 	if (err) {
6046 		EXT4_SB(sb)->s_journal = NULL;
6047 		jbd2_journal_destroy(journal);
6048 		return err;
6049 	}
6050 
6051 	if (!really_read_only && journal_devnum &&
6052 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6053 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6054 		ext4_commit_super(sb);
6055 	}
6056 	if (!really_read_only && journal_inum &&
6057 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6058 		es->s_journal_inum = cpu_to_le32(journal_inum);
6059 		ext4_commit_super(sb);
6060 	}
6061 
6062 	return 0;
6063 
6064 err_out:
6065 	jbd2_journal_destroy(journal);
6066 	return err;
6067 }
6068 
6069 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6070 static void ext4_update_super(struct super_block *sb)
6071 {
6072 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6073 	struct ext4_super_block *es = sbi->s_es;
6074 	struct buffer_head *sbh = sbi->s_sbh;
6075 
6076 	lock_buffer(sbh);
6077 	/*
6078 	 * If the file system is mounted read-only, don't update the
6079 	 * superblock write time.  This avoids updating the superblock
6080 	 * write time when we are mounting the root file system
6081 	 * read/only but we need to replay the journal; at that point,
6082 	 * for people who are east of GMT and who make their clock
6083 	 * tick in localtime for Windows bug-for-bug compatibility,
6084 	 * the clock is set in the future, and this will cause e2fsck
6085 	 * to complain and force a full file system check.
6086 	 */
6087 	if (!(sb->s_flags & SB_RDONLY))
6088 		ext4_update_tstamp(es, s_wtime);
6089 	es->s_kbytes_written =
6090 		cpu_to_le64(sbi->s_kbytes_written +
6091 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6092 		      sbi->s_sectors_written_start) >> 1));
6093 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6094 		ext4_free_blocks_count_set(es,
6095 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6096 				&sbi->s_freeclusters_counter)));
6097 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6098 		es->s_free_inodes_count =
6099 			cpu_to_le32(percpu_counter_sum_positive(
6100 				&sbi->s_freeinodes_counter));
6101 	/* Copy error information to the on-disk superblock */
6102 	spin_lock(&sbi->s_error_lock);
6103 	if (sbi->s_add_error_count > 0) {
6104 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6105 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6106 			__ext4_update_tstamp(&es->s_first_error_time,
6107 					     &es->s_first_error_time_hi,
6108 					     sbi->s_first_error_time);
6109 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6110 				sizeof(es->s_first_error_func));
6111 			es->s_first_error_line =
6112 				cpu_to_le32(sbi->s_first_error_line);
6113 			es->s_first_error_ino =
6114 				cpu_to_le32(sbi->s_first_error_ino);
6115 			es->s_first_error_block =
6116 				cpu_to_le64(sbi->s_first_error_block);
6117 			es->s_first_error_errcode =
6118 				ext4_errno_to_code(sbi->s_first_error_code);
6119 		}
6120 		__ext4_update_tstamp(&es->s_last_error_time,
6121 				     &es->s_last_error_time_hi,
6122 				     sbi->s_last_error_time);
6123 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6124 			sizeof(es->s_last_error_func));
6125 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6126 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6127 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6128 		es->s_last_error_errcode =
6129 				ext4_errno_to_code(sbi->s_last_error_code);
6130 		/*
6131 		 * Start the daily error reporting function if it hasn't been
6132 		 * started already
6133 		 */
6134 		if (!es->s_error_count)
6135 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6136 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6137 		sbi->s_add_error_count = 0;
6138 	}
6139 	spin_unlock(&sbi->s_error_lock);
6140 
6141 	ext4_superblock_csum_set(sb);
6142 	unlock_buffer(sbh);
6143 }
6144 
6145 static int ext4_commit_super(struct super_block *sb)
6146 {
6147 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6148 
6149 	if (!sbh)
6150 		return -EINVAL;
6151 	if (block_device_ejected(sb))
6152 		return -ENODEV;
6153 
6154 	ext4_update_super(sb);
6155 
6156 	lock_buffer(sbh);
6157 	/* Buffer got discarded which means block device got invalidated */
6158 	if (!buffer_mapped(sbh)) {
6159 		unlock_buffer(sbh);
6160 		return -EIO;
6161 	}
6162 
6163 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6164 		/*
6165 		 * Oh, dear.  A previous attempt to write the
6166 		 * superblock failed.  This could happen because the
6167 		 * USB device was yanked out.  Or it could happen to
6168 		 * be a transient write error and maybe the block will
6169 		 * be remapped.  Nothing we can do but to retry the
6170 		 * write and hope for the best.
6171 		 */
6172 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6173 		       "superblock detected");
6174 		clear_buffer_write_io_error(sbh);
6175 		set_buffer_uptodate(sbh);
6176 	}
6177 	get_bh(sbh);
6178 	/* Clear potential dirty bit if it was journalled update */
6179 	clear_buffer_dirty(sbh);
6180 	sbh->b_end_io = end_buffer_write_sync;
6181 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6182 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6183 	wait_on_buffer(sbh);
6184 	if (buffer_write_io_error(sbh)) {
6185 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6186 		       "superblock");
6187 		clear_buffer_write_io_error(sbh);
6188 		set_buffer_uptodate(sbh);
6189 		return -EIO;
6190 	}
6191 	return 0;
6192 }
6193 
6194 /*
6195  * Have we just finished recovery?  If so, and if we are mounting (or
6196  * remounting) the filesystem readonly, then we will end up with a
6197  * consistent fs on disk.  Record that fact.
6198  */
6199 static int ext4_mark_recovery_complete(struct super_block *sb,
6200 				       struct ext4_super_block *es)
6201 {
6202 	int err;
6203 	journal_t *journal = EXT4_SB(sb)->s_journal;
6204 
6205 	if (!ext4_has_feature_journal(sb)) {
6206 		if (journal != NULL) {
6207 			ext4_error(sb, "Journal got removed while the fs was "
6208 				   "mounted!");
6209 			return -EFSCORRUPTED;
6210 		}
6211 		return 0;
6212 	}
6213 	jbd2_journal_lock_updates(journal);
6214 	err = jbd2_journal_flush(journal, 0);
6215 	if (err < 0)
6216 		goto out;
6217 
6218 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6219 	    ext4_has_feature_orphan_present(sb))) {
6220 		if (!ext4_orphan_file_empty(sb)) {
6221 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6222 			err = -EFSCORRUPTED;
6223 			goto out;
6224 		}
6225 		ext4_clear_feature_journal_needs_recovery(sb);
6226 		ext4_clear_feature_orphan_present(sb);
6227 		ext4_commit_super(sb);
6228 	}
6229 out:
6230 	jbd2_journal_unlock_updates(journal);
6231 	return err;
6232 }
6233 
6234 /*
6235  * If we are mounting (or read-write remounting) a filesystem whose journal
6236  * has recorded an error from a previous lifetime, move that error to the
6237  * main filesystem now.
6238  */
6239 static int ext4_clear_journal_err(struct super_block *sb,
6240 				   struct ext4_super_block *es)
6241 {
6242 	journal_t *journal;
6243 	int j_errno;
6244 	const char *errstr;
6245 
6246 	if (!ext4_has_feature_journal(sb)) {
6247 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6248 		return -EFSCORRUPTED;
6249 	}
6250 
6251 	journal = EXT4_SB(sb)->s_journal;
6252 
6253 	/*
6254 	 * Now check for any error status which may have been recorded in the
6255 	 * journal by a prior ext4_error() or ext4_abort()
6256 	 */
6257 
6258 	j_errno = jbd2_journal_errno(journal);
6259 	if (j_errno) {
6260 		char nbuf[16];
6261 
6262 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6263 		ext4_warning(sb, "Filesystem error recorded "
6264 			     "from previous mount: %s", errstr);
6265 
6266 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6267 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6268 		j_errno = ext4_commit_super(sb);
6269 		if (j_errno)
6270 			return j_errno;
6271 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6272 
6273 		jbd2_journal_clear_err(journal);
6274 		jbd2_journal_update_sb_errno(journal);
6275 	}
6276 	return 0;
6277 }
6278 
6279 /*
6280  * Force the running and committing transactions to commit,
6281  * and wait on the commit.
6282  */
6283 int ext4_force_commit(struct super_block *sb)
6284 {
6285 	journal_t *journal;
6286 
6287 	if (sb_rdonly(sb))
6288 		return 0;
6289 
6290 	journal = EXT4_SB(sb)->s_journal;
6291 	return ext4_journal_force_commit(journal);
6292 }
6293 
6294 static int ext4_sync_fs(struct super_block *sb, int wait)
6295 {
6296 	int ret = 0;
6297 	tid_t target;
6298 	bool needs_barrier = false;
6299 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6300 
6301 	if (unlikely(ext4_forced_shutdown(sbi)))
6302 		return 0;
6303 
6304 	trace_ext4_sync_fs(sb, wait);
6305 	flush_workqueue(sbi->rsv_conversion_wq);
6306 	/*
6307 	 * Writeback quota in non-journalled quota case - journalled quota has
6308 	 * no dirty dquots
6309 	 */
6310 	dquot_writeback_dquots(sb, -1);
6311 	/*
6312 	 * Data writeback is possible w/o journal transaction, so barrier must
6313 	 * being sent at the end of the function. But we can skip it if
6314 	 * transaction_commit will do it for us.
6315 	 */
6316 	if (sbi->s_journal) {
6317 		target = jbd2_get_latest_transaction(sbi->s_journal);
6318 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6319 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6320 			needs_barrier = true;
6321 
6322 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6323 			if (wait)
6324 				ret = jbd2_log_wait_commit(sbi->s_journal,
6325 							   target);
6326 		}
6327 	} else if (wait && test_opt(sb, BARRIER))
6328 		needs_barrier = true;
6329 	if (needs_barrier) {
6330 		int err;
6331 		err = blkdev_issue_flush(sb->s_bdev);
6332 		if (!ret)
6333 			ret = err;
6334 	}
6335 
6336 	return ret;
6337 }
6338 
6339 /*
6340  * LVM calls this function before a (read-only) snapshot is created.  This
6341  * gives us a chance to flush the journal completely and mark the fs clean.
6342  *
6343  * Note that only this function cannot bring a filesystem to be in a clean
6344  * state independently. It relies on upper layer to stop all data & metadata
6345  * modifications.
6346  */
6347 static int ext4_freeze(struct super_block *sb)
6348 {
6349 	int error = 0;
6350 	journal_t *journal;
6351 
6352 	if (sb_rdonly(sb))
6353 		return 0;
6354 
6355 	journal = EXT4_SB(sb)->s_journal;
6356 
6357 	if (journal) {
6358 		/* Now we set up the journal barrier. */
6359 		jbd2_journal_lock_updates(journal);
6360 
6361 		/*
6362 		 * Don't clear the needs_recovery flag if we failed to
6363 		 * flush the journal.
6364 		 */
6365 		error = jbd2_journal_flush(journal, 0);
6366 		if (error < 0)
6367 			goto out;
6368 
6369 		/* Journal blocked and flushed, clear needs_recovery flag. */
6370 		ext4_clear_feature_journal_needs_recovery(sb);
6371 		if (ext4_orphan_file_empty(sb))
6372 			ext4_clear_feature_orphan_present(sb);
6373 	}
6374 
6375 	error = ext4_commit_super(sb);
6376 out:
6377 	if (journal)
6378 		/* we rely on upper layer to stop further updates */
6379 		jbd2_journal_unlock_updates(journal);
6380 	return error;
6381 }
6382 
6383 /*
6384  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6385  * flag here, even though the filesystem is not technically dirty yet.
6386  */
6387 static int ext4_unfreeze(struct super_block *sb)
6388 {
6389 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6390 		return 0;
6391 
6392 	if (EXT4_SB(sb)->s_journal) {
6393 		/* Reset the needs_recovery flag before the fs is unlocked. */
6394 		ext4_set_feature_journal_needs_recovery(sb);
6395 		if (ext4_has_feature_orphan_file(sb))
6396 			ext4_set_feature_orphan_present(sb);
6397 	}
6398 
6399 	ext4_commit_super(sb);
6400 	return 0;
6401 }
6402 
6403 /*
6404  * Structure to save mount options for ext4_remount's benefit
6405  */
6406 struct ext4_mount_options {
6407 	unsigned long s_mount_opt;
6408 	unsigned long s_mount_opt2;
6409 	kuid_t s_resuid;
6410 	kgid_t s_resgid;
6411 	unsigned long s_commit_interval;
6412 	u32 s_min_batch_time, s_max_batch_time;
6413 #ifdef CONFIG_QUOTA
6414 	int s_jquota_fmt;
6415 	char *s_qf_names[EXT4_MAXQUOTAS];
6416 #endif
6417 };
6418 
6419 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6420 {
6421 	struct ext4_fs_context *ctx = fc->fs_private;
6422 	struct ext4_super_block *es;
6423 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6424 	unsigned long old_sb_flags;
6425 	struct ext4_mount_options old_opts;
6426 	ext4_group_t g;
6427 	int err = 0;
6428 #ifdef CONFIG_QUOTA
6429 	int enable_quota = 0;
6430 	int i, j;
6431 	char *to_free[EXT4_MAXQUOTAS];
6432 #endif
6433 
6434 
6435 	/* Store the original options */
6436 	old_sb_flags = sb->s_flags;
6437 	old_opts.s_mount_opt = sbi->s_mount_opt;
6438 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6439 	old_opts.s_resuid = sbi->s_resuid;
6440 	old_opts.s_resgid = sbi->s_resgid;
6441 	old_opts.s_commit_interval = sbi->s_commit_interval;
6442 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6443 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6444 #ifdef CONFIG_QUOTA
6445 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6446 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6447 		if (sbi->s_qf_names[i]) {
6448 			char *qf_name = get_qf_name(sb, sbi, i);
6449 
6450 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6451 			if (!old_opts.s_qf_names[i]) {
6452 				for (j = 0; j < i; j++)
6453 					kfree(old_opts.s_qf_names[j]);
6454 				return -ENOMEM;
6455 			}
6456 		} else
6457 			old_opts.s_qf_names[i] = NULL;
6458 #endif
6459 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6460 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6461 			ctx->journal_ioprio =
6462 				sbi->s_journal->j_task->io_context->ioprio;
6463 		else
6464 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6465 
6466 	}
6467 
6468 	ext4_apply_options(fc, sb);
6469 
6470 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6471 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6472 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6473 			 "during remount not supported; ignoring");
6474 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6475 	}
6476 
6477 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6478 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6479 			ext4_msg(sb, KERN_ERR, "can't mount with "
6480 				 "both data=journal and delalloc");
6481 			err = -EINVAL;
6482 			goto restore_opts;
6483 		}
6484 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6485 			ext4_msg(sb, KERN_ERR, "can't mount with "
6486 				 "both data=journal and dioread_nolock");
6487 			err = -EINVAL;
6488 			goto restore_opts;
6489 		}
6490 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6491 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6492 			ext4_msg(sb, KERN_ERR, "can't mount with "
6493 				"journal_async_commit in data=ordered mode");
6494 			err = -EINVAL;
6495 			goto restore_opts;
6496 		}
6497 	}
6498 
6499 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6500 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6501 		err = -EINVAL;
6502 		goto restore_opts;
6503 	}
6504 
6505 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6506 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6507 
6508 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6509 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6510 
6511 	es = sbi->s_es;
6512 
6513 	if (sbi->s_journal) {
6514 		ext4_init_journal_params(sb, sbi->s_journal);
6515 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6516 	}
6517 
6518 	/* Flush outstanding errors before changing fs state */
6519 	flush_work(&sbi->s_error_work);
6520 
6521 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6522 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6523 			err = -EROFS;
6524 			goto restore_opts;
6525 		}
6526 
6527 		if (fc->sb_flags & SB_RDONLY) {
6528 			err = sync_filesystem(sb);
6529 			if (err < 0)
6530 				goto restore_opts;
6531 			err = dquot_suspend(sb, -1);
6532 			if (err < 0)
6533 				goto restore_opts;
6534 
6535 			/*
6536 			 * First of all, the unconditional stuff we have to do
6537 			 * to disable replay of the journal when we next remount
6538 			 */
6539 			sb->s_flags |= SB_RDONLY;
6540 
6541 			/*
6542 			 * OK, test if we are remounting a valid rw partition
6543 			 * readonly, and if so set the rdonly flag and then
6544 			 * mark the partition as valid again.
6545 			 */
6546 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6547 			    (sbi->s_mount_state & EXT4_VALID_FS))
6548 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6549 
6550 			if (sbi->s_journal) {
6551 				/*
6552 				 * We let remount-ro finish even if marking fs
6553 				 * as clean failed...
6554 				 */
6555 				ext4_mark_recovery_complete(sb, es);
6556 			}
6557 		} else {
6558 			/* Make sure we can mount this feature set readwrite */
6559 			if (ext4_has_feature_readonly(sb) ||
6560 			    !ext4_feature_set_ok(sb, 0)) {
6561 				err = -EROFS;
6562 				goto restore_opts;
6563 			}
6564 			/*
6565 			 * Make sure the group descriptor checksums
6566 			 * are sane.  If they aren't, refuse to remount r/w.
6567 			 */
6568 			for (g = 0; g < sbi->s_groups_count; g++) {
6569 				struct ext4_group_desc *gdp =
6570 					ext4_get_group_desc(sb, g, NULL);
6571 
6572 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6573 					ext4_msg(sb, KERN_ERR,
6574 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6575 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6576 					       le16_to_cpu(gdp->bg_checksum));
6577 					err = -EFSBADCRC;
6578 					goto restore_opts;
6579 				}
6580 			}
6581 
6582 			/*
6583 			 * If we have an unprocessed orphan list hanging
6584 			 * around from a previously readonly bdev mount,
6585 			 * require a full umount/remount for now.
6586 			 */
6587 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6588 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6589 				       "remount RDWR because of unprocessed "
6590 				       "orphan inode list.  Please "
6591 				       "umount/remount instead");
6592 				err = -EINVAL;
6593 				goto restore_opts;
6594 			}
6595 
6596 			/*
6597 			 * Mounting a RDONLY partition read-write, so reread
6598 			 * and store the current valid flag.  (It may have
6599 			 * been changed by e2fsck since we originally mounted
6600 			 * the partition.)
6601 			 */
6602 			if (sbi->s_journal) {
6603 				err = ext4_clear_journal_err(sb, es);
6604 				if (err)
6605 					goto restore_opts;
6606 			}
6607 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6608 					      ~EXT4_FC_REPLAY);
6609 
6610 			err = ext4_setup_super(sb, es, 0);
6611 			if (err)
6612 				goto restore_opts;
6613 
6614 			sb->s_flags &= ~SB_RDONLY;
6615 			if (ext4_has_feature_mmp(sb)) {
6616 				err = ext4_multi_mount_protect(sb,
6617 						le64_to_cpu(es->s_mmp_block));
6618 				if (err)
6619 					goto restore_opts;
6620 			}
6621 #ifdef CONFIG_QUOTA
6622 			enable_quota = 1;
6623 #endif
6624 		}
6625 	}
6626 
6627 	/*
6628 	 * Handle creation of system zone data early because it can fail.
6629 	 * Releasing of existing data is done when we are sure remount will
6630 	 * succeed.
6631 	 */
6632 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6633 		err = ext4_setup_system_zone(sb);
6634 		if (err)
6635 			goto restore_opts;
6636 	}
6637 
6638 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6639 		err = ext4_commit_super(sb);
6640 		if (err)
6641 			goto restore_opts;
6642 	}
6643 
6644 #ifdef CONFIG_QUOTA
6645 	if (enable_quota) {
6646 		if (sb_any_quota_suspended(sb))
6647 			dquot_resume(sb, -1);
6648 		else if (ext4_has_feature_quota(sb)) {
6649 			err = ext4_enable_quotas(sb);
6650 			if (err)
6651 				goto restore_opts;
6652 		}
6653 	}
6654 	/* Release old quota file names */
6655 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6656 		kfree(old_opts.s_qf_names[i]);
6657 #endif
6658 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6659 		ext4_release_system_zone(sb);
6660 
6661 	/*
6662 	 * Reinitialize lazy itable initialization thread based on
6663 	 * current settings
6664 	 */
6665 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6666 		ext4_unregister_li_request(sb);
6667 	else {
6668 		ext4_group_t first_not_zeroed;
6669 		first_not_zeroed = ext4_has_uninit_itable(sb);
6670 		ext4_register_li_request(sb, first_not_zeroed);
6671 	}
6672 
6673 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6674 		ext4_stop_mmpd(sbi);
6675 
6676 	return 0;
6677 
6678 restore_opts:
6679 	/*
6680 	 * If there was a failing r/w to ro transition, we may need to
6681 	 * re-enable quota
6682 	 */
6683 	if ((sb->s_flags & SB_RDONLY) && !(old_sb_flags & SB_RDONLY) &&
6684 	    sb_any_quota_suspended(sb))
6685 		dquot_resume(sb, -1);
6686 	sb->s_flags = old_sb_flags;
6687 	sbi->s_mount_opt = old_opts.s_mount_opt;
6688 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6689 	sbi->s_resuid = old_opts.s_resuid;
6690 	sbi->s_resgid = old_opts.s_resgid;
6691 	sbi->s_commit_interval = old_opts.s_commit_interval;
6692 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6693 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6694 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6695 		ext4_release_system_zone(sb);
6696 #ifdef CONFIG_QUOTA
6697 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6698 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6699 		to_free[i] = get_qf_name(sb, sbi, i);
6700 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6701 	}
6702 	synchronize_rcu();
6703 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6704 		kfree(to_free[i]);
6705 #endif
6706 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6707 		ext4_stop_mmpd(sbi);
6708 	return err;
6709 }
6710 
6711 static int ext4_reconfigure(struct fs_context *fc)
6712 {
6713 	struct super_block *sb = fc->root->d_sb;
6714 	int ret;
6715 
6716 	fc->s_fs_info = EXT4_SB(sb);
6717 
6718 	ret = ext4_check_opt_consistency(fc, sb);
6719 	if (ret < 0)
6720 		return ret;
6721 
6722 	ret = __ext4_remount(fc, sb);
6723 	if (ret < 0)
6724 		return ret;
6725 
6726 	ext4_msg(sb, KERN_INFO, "re-mounted %pU %s. Quota mode: %s.",
6727 		 &sb->s_uuid, sb_rdonly(sb) ? "ro" : "r/w",
6728 		 ext4_quota_mode(sb));
6729 
6730 	return 0;
6731 }
6732 
6733 #ifdef CONFIG_QUOTA
6734 static int ext4_statfs_project(struct super_block *sb,
6735 			       kprojid_t projid, struct kstatfs *buf)
6736 {
6737 	struct kqid qid;
6738 	struct dquot *dquot;
6739 	u64 limit;
6740 	u64 curblock;
6741 
6742 	qid = make_kqid_projid(projid);
6743 	dquot = dqget(sb, qid);
6744 	if (IS_ERR(dquot))
6745 		return PTR_ERR(dquot);
6746 	spin_lock(&dquot->dq_dqb_lock);
6747 
6748 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6749 			     dquot->dq_dqb.dqb_bhardlimit);
6750 	limit >>= sb->s_blocksize_bits;
6751 
6752 	if (limit && buf->f_blocks > limit) {
6753 		curblock = (dquot->dq_dqb.dqb_curspace +
6754 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6755 		buf->f_blocks = limit;
6756 		buf->f_bfree = buf->f_bavail =
6757 			(buf->f_blocks > curblock) ?
6758 			 (buf->f_blocks - curblock) : 0;
6759 	}
6760 
6761 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6762 			     dquot->dq_dqb.dqb_ihardlimit);
6763 	if (limit && buf->f_files > limit) {
6764 		buf->f_files = limit;
6765 		buf->f_ffree =
6766 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6767 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6768 	}
6769 
6770 	spin_unlock(&dquot->dq_dqb_lock);
6771 	dqput(dquot);
6772 	return 0;
6773 }
6774 #endif
6775 
6776 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6777 {
6778 	struct super_block *sb = dentry->d_sb;
6779 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6780 	struct ext4_super_block *es = sbi->s_es;
6781 	ext4_fsblk_t overhead = 0, resv_blocks;
6782 	s64 bfree;
6783 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6784 
6785 	if (!test_opt(sb, MINIX_DF))
6786 		overhead = sbi->s_overhead;
6787 
6788 	buf->f_type = EXT4_SUPER_MAGIC;
6789 	buf->f_bsize = sb->s_blocksize;
6790 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6791 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6792 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6793 	/* prevent underflow in case that few free space is available */
6794 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6795 	buf->f_bavail = buf->f_bfree -
6796 			(ext4_r_blocks_count(es) + resv_blocks);
6797 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6798 		buf->f_bavail = 0;
6799 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6800 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6801 	buf->f_namelen = EXT4_NAME_LEN;
6802 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6803 
6804 #ifdef CONFIG_QUOTA
6805 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6806 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6807 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6808 #endif
6809 	return 0;
6810 }
6811 
6812 
6813 #ifdef CONFIG_QUOTA
6814 
6815 /*
6816  * Helper functions so that transaction is started before we acquire dqio_sem
6817  * to keep correct lock ordering of transaction > dqio_sem
6818  */
6819 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6820 {
6821 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6822 }
6823 
6824 static int ext4_write_dquot(struct dquot *dquot)
6825 {
6826 	int ret, err;
6827 	handle_t *handle;
6828 	struct inode *inode;
6829 
6830 	inode = dquot_to_inode(dquot);
6831 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6832 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6833 	if (IS_ERR(handle))
6834 		return PTR_ERR(handle);
6835 	ret = dquot_commit(dquot);
6836 	err = ext4_journal_stop(handle);
6837 	if (!ret)
6838 		ret = err;
6839 	return ret;
6840 }
6841 
6842 static int ext4_acquire_dquot(struct dquot *dquot)
6843 {
6844 	int ret, err;
6845 	handle_t *handle;
6846 
6847 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6848 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6849 	if (IS_ERR(handle))
6850 		return PTR_ERR(handle);
6851 	ret = dquot_acquire(dquot);
6852 	err = ext4_journal_stop(handle);
6853 	if (!ret)
6854 		ret = err;
6855 	return ret;
6856 }
6857 
6858 static int ext4_release_dquot(struct dquot *dquot)
6859 {
6860 	int ret, err;
6861 	handle_t *handle;
6862 
6863 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6864 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6865 	if (IS_ERR(handle)) {
6866 		/* Release dquot anyway to avoid endless cycle in dqput() */
6867 		dquot_release(dquot);
6868 		return PTR_ERR(handle);
6869 	}
6870 	ret = dquot_release(dquot);
6871 	err = ext4_journal_stop(handle);
6872 	if (!ret)
6873 		ret = err;
6874 	return ret;
6875 }
6876 
6877 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6878 {
6879 	struct super_block *sb = dquot->dq_sb;
6880 
6881 	if (ext4_is_quota_journalled(sb)) {
6882 		dquot_mark_dquot_dirty(dquot);
6883 		return ext4_write_dquot(dquot);
6884 	} else {
6885 		return dquot_mark_dquot_dirty(dquot);
6886 	}
6887 }
6888 
6889 static int ext4_write_info(struct super_block *sb, int type)
6890 {
6891 	int ret, err;
6892 	handle_t *handle;
6893 
6894 	/* Data block + inode block */
6895 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6896 	if (IS_ERR(handle))
6897 		return PTR_ERR(handle);
6898 	ret = dquot_commit_info(sb, type);
6899 	err = ext4_journal_stop(handle);
6900 	if (!ret)
6901 		ret = err;
6902 	return ret;
6903 }
6904 
6905 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6906 {
6907 	struct ext4_inode_info *ei = EXT4_I(inode);
6908 
6909 	/* The first argument of lockdep_set_subclass has to be
6910 	 * *exactly* the same as the argument to init_rwsem() --- in
6911 	 * this case, in init_once() --- or lockdep gets unhappy
6912 	 * because the name of the lock is set using the
6913 	 * stringification of the argument to init_rwsem().
6914 	 */
6915 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6916 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6917 }
6918 
6919 /*
6920  * Standard function to be called on quota_on
6921  */
6922 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6923 			 const struct path *path)
6924 {
6925 	int err;
6926 
6927 	if (!test_opt(sb, QUOTA))
6928 		return -EINVAL;
6929 
6930 	/* Quotafile not on the same filesystem? */
6931 	if (path->dentry->d_sb != sb)
6932 		return -EXDEV;
6933 
6934 	/* Quota already enabled for this file? */
6935 	if (IS_NOQUOTA(d_inode(path->dentry)))
6936 		return -EBUSY;
6937 
6938 	/* Journaling quota? */
6939 	if (EXT4_SB(sb)->s_qf_names[type]) {
6940 		/* Quotafile not in fs root? */
6941 		if (path->dentry->d_parent != sb->s_root)
6942 			ext4_msg(sb, KERN_WARNING,
6943 				"Quota file not on filesystem root. "
6944 				"Journaled quota will not work");
6945 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6946 	} else {
6947 		/*
6948 		 * Clear the flag just in case mount options changed since
6949 		 * last time.
6950 		 */
6951 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6952 	}
6953 
6954 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6955 	err = dquot_quota_on(sb, type, format_id, path);
6956 	if (!err) {
6957 		struct inode *inode = d_inode(path->dentry);
6958 		handle_t *handle;
6959 
6960 		/*
6961 		 * Set inode flags to prevent userspace from messing with quota
6962 		 * files. If this fails, we return success anyway since quotas
6963 		 * are already enabled and this is not a hard failure.
6964 		 */
6965 		inode_lock(inode);
6966 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6967 		if (IS_ERR(handle))
6968 			goto unlock_inode;
6969 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6970 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6971 				S_NOATIME | S_IMMUTABLE);
6972 		err = ext4_mark_inode_dirty(handle, inode);
6973 		ext4_journal_stop(handle);
6974 	unlock_inode:
6975 		inode_unlock(inode);
6976 		if (err)
6977 			dquot_quota_off(sb, type);
6978 	}
6979 	if (err)
6980 		lockdep_set_quota_inode(path->dentry->d_inode,
6981 					     I_DATA_SEM_NORMAL);
6982 	return err;
6983 }
6984 
6985 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
6986 {
6987 	switch (type) {
6988 	case USRQUOTA:
6989 		return qf_inum == EXT4_USR_QUOTA_INO;
6990 	case GRPQUOTA:
6991 		return qf_inum == EXT4_GRP_QUOTA_INO;
6992 	case PRJQUOTA:
6993 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
6994 	default:
6995 		BUG();
6996 	}
6997 }
6998 
6999 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7000 			     unsigned int flags)
7001 {
7002 	int err;
7003 	struct inode *qf_inode;
7004 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7005 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7006 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7007 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7008 	};
7009 
7010 	BUG_ON(!ext4_has_feature_quota(sb));
7011 
7012 	if (!qf_inums[type])
7013 		return -EPERM;
7014 
7015 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7016 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7017 				qf_inums[type], type);
7018 		return -EUCLEAN;
7019 	}
7020 
7021 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7022 	if (IS_ERR(qf_inode)) {
7023 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7024 				qf_inums[type], type);
7025 		return PTR_ERR(qf_inode);
7026 	}
7027 
7028 	/* Don't account quota for quota files to avoid recursion */
7029 	qf_inode->i_flags |= S_NOQUOTA;
7030 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7031 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7032 	if (err)
7033 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7034 	iput(qf_inode);
7035 
7036 	return err;
7037 }
7038 
7039 /* Enable usage tracking for all quota types. */
7040 int ext4_enable_quotas(struct super_block *sb)
7041 {
7042 	int type, err = 0;
7043 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7044 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7045 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7046 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7047 	};
7048 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7049 		test_opt(sb, USRQUOTA),
7050 		test_opt(sb, GRPQUOTA),
7051 		test_opt(sb, PRJQUOTA),
7052 	};
7053 
7054 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7055 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7056 		if (qf_inums[type]) {
7057 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7058 				DQUOT_USAGE_ENABLED |
7059 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7060 			if (err) {
7061 				ext4_warning(sb,
7062 					"Failed to enable quota tracking "
7063 					"(type=%d, err=%d, ino=%lu). "
7064 					"Please run e2fsck to fix.", type,
7065 					err, qf_inums[type]);
7066 
7067 				ext4_quotas_off(sb, type);
7068 				return err;
7069 			}
7070 		}
7071 	}
7072 	return 0;
7073 }
7074 
7075 static int ext4_quota_off(struct super_block *sb, int type)
7076 {
7077 	struct inode *inode = sb_dqopt(sb)->files[type];
7078 	handle_t *handle;
7079 	int err;
7080 
7081 	/* Force all delayed allocation blocks to be allocated.
7082 	 * Caller already holds s_umount sem */
7083 	if (test_opt(sb, DELALLOC))
7084 		sync_filesystem(sb);
7085 
7086 	if (!inode || !igrab(inode))
7087 		goto out;
7088 
7089 	err = dquot_quota_off(sb, type);
7090 	if (err || ext4_has_feature_quota(sb))
7091 		goto out_put;
7092 
7093 	inode_lock(inode);
7094 	/*
7095 	 * Update modification times of quota files when userspace can
7096 	 * start looking at them. If we fail, we return success anyway since
7097 	 * this is not a hard failure and quotas are already disabled.
7098 	 */
7099 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7100 	if (IS_ERR(handle)) {
7101 		err = PTR_ERR(handle);
7102 		goto out_unlock;
7103 	}
7104 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7105 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7106 	inode->i_mtime = inode->i_ctime = current_time(inode);
7107 	err = ext4_mark_inode_dirty(handle, inode);
7108 	ext4_journal_stop(handle);
7109 out_unlock:
7110 	inode_unlock(inode);
7111 out_put:
7112 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7113 	iput(inode);
7114 	return err;
7115 out:
7116 	return dquot_quota_off(sb, type);
7117 }
7118 
7119 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7120  * acquiring the locks... As quota files are never truncated and quota code
7121  * itself serializes the operations (and no one else should touch the files)
7122  * we don't have to be afraid of races */
7123 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7124 			       size_t len, loff_t off)
7125 {
7126 	struct inode *inode = sb_dqopt(sb)->files[type];
7127 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7128 	int offset = off & (sb->s_blocksize - 1);
7129 	int tocopy;
7130 	size_t toread;
7131 	struct buffer_head *bh;
7132 	loff_t i_size = i_size_read(inode);
7133 
7134 	if (off > i_size)
7135 		return 0;
7136 	if (off+len > i_size)
7137 		len = i_size-off;
7138 	toread = len;
7139 	while (toread > 0) {
7140 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7141 		bh = ext4_bread(NULL, inode, blk, 0);
7142 		if (IS_ERR(bh))
7143 			return PTR_ERR(bh);
7144 		if (!bh)	/* A hole? */
7145 			memset(data, 0, tocopy);
7146 		else
7147 			memcpy(data, bh->b_data+offset, tocopy);
7148 		brelse(bh);
7149 		offset = 0;
7150 		toread -= tocopy;
7151 		data += tocopy;
7152 		blk++;
7153 	}
7154 	return len;
7155 }
7156 
7157 /* Write to quotafile (we know the transaction is already started and has
7158  * enough credits) */
7159 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7160 				const char *data, size_t len, loff_t off)
7161 {
7162 	struct inode *inode = sb_dqopt(sb)->files[type];
7163 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7164 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7165 	int retries = 0;
7166 	struct buffer_head *bh;
7167 	handle_t *handle = journal_current_handle();
7168 
7169 	if (!handle) {
7170 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7171 			" cancelled because transaction is not started",
7172 			(unsigned long long)off, (unsigned long long)len);
7173 		return -EIO;
7174 	}
7175 	/*
7176 	 * Since we account only one data block in transaction credits,
7177 	 * then it is impossible to cross a block boundary.
7178 	 */
7179 	if (sb->s_blocksize - offset < len) {
7180 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7181 			" cancelled because not block aligned",
7182 			(unsigned long long)off, (unsigned long long)len);
7183 		return -EIO;
7184 	}
7185 
7186 	do {
7187 		bh = ext4_bread(handle, inode, blk,
7188 				EXT4_GET_BLOCKS_CREATE |
7189 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7190 	} while (PTR_ERR(bh) == -ENOSPC &&
7191 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7192 	if (IS_ERR(bh))
7193 		return PTR_ERR(bh);
7194 	if (!bh)
7195 		goto out;
7196 	BUFFER_TRACE(bh, "get write access");
7197 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7198 	if (err) {
7199 		brelse(bh);
7200 		return err;
7201 	}
7202 	lock_buffer(bh);
7203 	memcpy(bh->b_data+offset, data, len);
7204 	flush_dcache_page(bh->b_page);
7205 	unlock_buffer(bh);
7206 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7207 	brelse(bh);
7208 out:
7209 	if (inode->i_size < off + len) {
7210 		i_size_write(inode, off + len);
7211 		EXT4_I(inode)->i_disksize = inode->i_size;
7212 		err2 = ext4_mark_inode_dirty(handle, inode);
7213 		if (unlikely(err2 && !err))
7214 			err = err2;
7215 	}
7216 	return err ? err : len;
7217 }
7218 #endif
7219 
7220 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7221 static inline void register_as_ext2(void)
7222 {
7223 	int err = register_filesystem(&ext2_fs_type);
7224 	if (err)
7225 		printk(KERN_WARNING
7226 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7227 }
7228 
7229 static inline void unregister_as_ext2(void)
7230 {
7231 	unregister_filesystem(&ext2_fs_type);
7232 }
7233 
7234 static inline int ext2_feature_set_ok(struct super_block *sb)
7235 {
7236 	if (ext4_has_unknown_ext2_incompat_features(sb))
7237 		return 0;
7238 	if (sb_rdonly(sb))
7239 		return 1;
7240 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7241 		return 0;
7242 	return 1;
7243 }
7244 #else
7245 static inline void register_as_ext2(void) { }
7246 static inline void unregister_as_ext2(void) { }
7247 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7248 #endif
7249 
7250 static inline void register_as_ext3(void)
7251 {
7252 	int err = register_filesystem(&ext3_fs_type);
7253 	if (err)
7254 		printk(KERN_WARNING
7255 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7256 }
7257 
7258 static inline void unregister_as_ext3(void)
7259 {
7260 	unregister_filesystem(&ext3_fs_type);
7261 }
7262 
7263 static inline int ext3_feature_set_ok(struct super_block *sb)
7264 {
7265 	if (ext4_has_unknown_ext3_incompat_features(sb))
7266 		return 0;
7267 	if (!ext4_has_feature_journal(sb))
7268 		return 0;
7269 	if (sb_rdonly(sb))
7270 		return 1;
7271 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7272 		return 0;
7273 	return 1;
7274 }
7275 
7276 static struct file_system_type ext4_fs_type = {
7277 	.owner			= THIS_MODULE,
7278 	.name			= "ext4",
7279 	.init_fs_context	= ext4_init_fs_context,
7280 	.parameters		= ext4_param_specs,
7281 	.kill_sb		= kill_block_super,
7282 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7283 };
7284 MODULE_ALIAS_FS("ext4");
7285 
7286 /* Shared across all ext4 file systems */
7287 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7288 
7289 static int __init ext4_init_fs(void)
7290 {
7291 	int i, err;
7292 
7293 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7294 	ext4_li_info = NULL;
7295 
7296 	/* Build-time check for flags consistency */
7297 	ext4_check_flag_values();
7298 
7299 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7300 		init_waitqueue_head(&ext4__ioend_wq[i]);
7301 
7302 	err = ext4_init_es();
7303 	if (err)
7304 		return err;
7305 
7306 	err = ext4_init_pending();
7307 	if (err)
7308 		goto out7;
7309 
7310 	err = ext4_init_post_read_processing();
7311 	if (err)
7312 		goto out6;
7313 
7314 	err = ext4_init_pageio();
7315 	if (err)
7316 		goto out5;
7317 
7318 	err = ext4_init_system_zone();
7319 	if (err)
7320 		goto out4;
7321 
7322 	err = ext4_init_sysfs();
7323 	if (err)
7324 		goto out3;
7325 
7326 	err = ext4_init_mballoc();
7327 	if (err)
7328 		goto out2;
7329 	err = init_inodecache();
7330 	if (err)
7331 		goto out1;
7332 
7333 	err = ext4_fc_init_dentry_cache();
7334 	if (err)
7335 		goto out05;
7336 
7337 	register_as_ext3();
7338 	register_as_ext2();
7339 	err = register_filesystem(&ext4_fs_type);
7340 	if (err)
7341 		goto out;
7342 
7343 	return 0;
7344 out:
7345 	unregister_as_ext2();
7346 	unregister_as_ext3();
7347 	ext4_fc_destroy_dentry_cache();
7348 out05:
7349 	destroy_inodecache();
7350 out1:
7351 	ext4_exit_mballoc();
7352 out2:
7353 	ext4_exit_sysfs();
7354 out3:
7355 	ext4_exit_system_zone();
7356 out4:
7357 	ext4_exit_pageio();
7358 out5:
7359 	ext4_exit_post_read_processing();
7360 out6:
7361 	ext4_exit_pending();
7362 out7:
7363 	ext4_exit_es();
7364 
7365 	return err;
7366 }
7367 
7368 static void __exit ext4_exit_fs(void)
7369 {
7370 	ext4_destroy_lazyinit_thread();
7371 	unregister_as_ext2();
7372 	unregister_as_ext3();
7373 	unregister_filesystem(&ext4_fs_type);
7374 	ext4_fc_destroy_dentry_cache();
7375 	destroy_inodecache();
7376 	ext4_exit_mballoc();
7377 	ext4_exit_sysfs();
7378 	ext4_exit_system_zone();
7379 	ext4_exit_pageio();
7380 	ext4_exit_post_read_processing();
7381 	ext4_exit_es();
7382 	ext4_exit_pending();
7383 }
7384 
7385 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7386 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7387 MODULE_LICENSE("GPL");
7388 MODULE_SOFTDEP("pre: crc32c");
7389 module_init(ext4_init_fs)
7390 module_exit(ext4_exit_fs)
7391