xref: /linux/fs/ext4/super.c (revision 8ccd54fe45713cd458015b5b08d6098545e70543)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= kill_block_super,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= kill_block_super,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ | op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
207 {
208 	lock_buffer(bh);
209 	if (!wait) {
210 		ext4_read_bh_nowait(bh, op_flags, NULL);
211 		return 0;
212 	}
213 	return ext4_read_bh(bh, op_flags, NULL);
214 }
215 
216 /*
217  * This works like __bread_gfp() except it uses ERR_PTR for error
218  * returns.  Currently with sb_bread it's impossible to distinguish
219  * between ENOMEM and EIO situations (since both result in a NULL
220  * return.
221  */
222 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
223 					       sector_t block,
224 					       blk_opf_t op_flags, gfp_t gfp)
225 {
226 	struct buffer_head *bh;
227 	int ret;
228 
229 	bh = sb_getblk_gfp(sb, block, gfp);
230 	if (bh == NULL)
231 		return ERR_PTR(-ENOMEM);
232 	if (ext4_buffer_uptodate(bh))
233 		return bh;
234 
235 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
236 	if (ret) {
237 		put_bh(bh);
238 		return ERR_PTR(ret);
239 	}
240 	return bh;
241 }
242 
243 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
244 				   blk_opf_t op_flags)
245 {
246 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
247 }
248 
249 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
250 					    sector_t block)
251 {
252 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
253 }
254 
255 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
256 {
257 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
258 
259 	if (likely(bh)) {
260 		if (trylock_buffer(bh))
261 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
262 		brelse(bh);
263 	}
264 }
265 
266 static int ext4_verify_csum_type(struct super_block *sb,
267 				 struct ext4_super_block *es)
268 {
269 	if (!ext4_has_feature_metadata_csum(sb))
270 		return 1;
271 
272 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
273 }
274 
275 __le32 ext4_superblock_csum(struct super_block *sb,
276 			    struct ext4_super_block *es)
277 {
278 	struct ext4_sb_info *sbi = EXT4_SB(sb);
279 	int offset = offsetof(struct ext4_super_block, s_checksum);
280 	__u32 csum;
281 
282 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
283 
284 	return cpu_to_le32(csum);
285 }
286 
287 static int ext4_superblock_csum_verify(struct super_block *sb,
288 				       struct ext4_super_block *es)
289 {
290 	if (!ext4_has_metadata_csum(sb))
291 		return 1;
292 
293 	return es->s_checksum == ext4_superblock_csum(sb, es);
294 }
295 
296 void ext4_superblock_csum_set(struct super_block *sb)
297 {
298 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
299 
300 	if (!ext4_has_metadata_csum(sb))
301 		return;
302 
303 	es->s_checksum = ext4_superblock_csum(sb, es);
304 }
305 
306 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
307 			       struct ext4_group_desc *bg)
308 {
309 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
310 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
311 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
312 }
313 
314 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
323 			      struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_table_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
328 }
329 
330 __u32 ext4_free_group_clusters(struct super_block *sb,
331 			       struct ext4_group_desc *bg)
332 {
333 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
336 }
337 
338 __u32 ext4_free_inodes_count(struct super_block *sb,
339 			      struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_used_dirs_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
352 }
353 
354 __u32 ext4_itable_unused_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_itable_unused_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
360 }
361 
362 void ext4_block_bitmap_set(struct super_block *sb,
363 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
364 {
365 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
366 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
367 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
368 }
369 
370 void ext4_inode_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_table_set(struct super_block *sb,
379 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_free_group_clusters_set(struct super_block *sb,
387 				  struct ext4_group_desc *bg, __u32 count)
388 {
389 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
392 }
393 
394 void ext4_free_inodes_set(struct super_block *sb,
395 			  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_used_dirs_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
408 }
409 
410 void ext4_itable_unused_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
416 }
417 
418 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
419 {
420 	now = clamp_val(now, 0, (1ull << 40) - 1);
421 
422 	*lo = cpu_to_le32(lower_32_bits(now));
423 	*hi = upper_32_bits(now);
424 }
425 
426 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
427 {
428 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
429 }
430 #define ext4_update_tstamp(es, tstamp) \
431 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
432 			     ktime_get_real_seconds())
433 #define ext4_get_tstamp(es, tstamp) \
434 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
435 
436 /*
437  * The del_gendisk() function uninitializes the disk-specific data
438  * structures, including the bdi structure, without telling anyone
439  * else.  Once this happens, any attempt to call mark_buffer_dirty()
440  * (for example, by ext4_commit_super), will cause a kernel OOPS.
441  * This is a kludge to prevent these oops until we can put in a proper
442  * hook in del_gendisk() to inform the VFS and file system layers.
443  */
444 static int block_device_ejected(struct super_block *sb)
445 {
446 	struct inode *bd_inode = sb->s_bdev->bd_inode;
447 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
448 
449 	return bdi->dev == NULL;
450 }
451 
452 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
453 {
454 	struct super_block		*sb = journal->j_private;
455 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
456 	int				error = is_journal_aborted(journal);
457 	struct ext4_journal_cb_entry	*jce;
458 
459 	BUG_ON(txn->t_state == T_FINISHED);
460 
461 	ext4_process_freed_data(sb, txn->t_tid);
462 
463 	spin_lock(&sbi->s_md_lock);
464 	while (!list_empty(&txn->t_private_list)) {
465 		jce = list_entry(txn->t_private_list.next,
466 				 struct ext4_journal_cb_entry, jce_list);
467 		list_del_init(&jce->jce_list);
468 		spin_unlock(&sbi->s_md_lock);
469 		jce->jce_func(sb, jce, error);
470 		spin_lock(&sbi->s_md_lock);
471 	}
472 	spin_unlock(&sbi->s_md_lock);
473 }
474 
475 /*
476  * This writepage callback for write_cache_pages()
477  * takes care of a few cases after page cleaning.
478  *
479  * write_cache_pages() already checks for dirty pages
480  * and calls clear_page_dirty_for_io(), which we want,
481  * to write protect the pages.
482  *
483  * However, we may have to redirty a page (see below.)
484  */
485 static int ext4_journalled_writepage_callback(struct folio *folio,
486 					      struct writeback_control *wbc,
487 					      void *data)
488 {
489 	transaction_t *transaction = (transaction_t *) data;
490 	struct buffer_head *bh, *head;
491 	struct journal_head *jh;
492 
493 	bh = head = folio_buffers(folio);
494 	do {
495 		/*
496 		 * We have to redirty a page in these cases:
497 		 * 1) If buffer is dirty, it means the page was dirty because it
498 		 * contains a buffer that needs checkpointing. So the dirty bit
499 		 * needs to be preserved so that checkpointing writes the buffer
500 		 * properly.
501 		 * 2) If buffer is not part of the committing transaction
502 		 * (we may have just accidentally come across this buffer because
503 		 * inode range tracking is not exact) or if the currently running
504 		 * transaction already contains this buffer as well, dirty bit
505 		 * needs to be preserved so that the buffer gets writeprotected
506 		 * properly on running transaction's commit.
507 		 */
508 		jh = bh2jh(bh);
509 		if (buffer_dirty(bh) ||
510 		    (jh && (jh->b_transaction != transaction ||
511 			    jh->b_next_transaction))) {
512 			folio_redirty_for_writepage(wbc, folio);
513 			goto out;
514 		}
515 	} while ((bh = bh->b_this_page) != head);
516 
517 out:
518 	return AOP_WRITEPAGE_ACTIVATE;
519 }
520 
521 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
522 {
523 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
524 	struct writeback_control wbc = {
525 		.sync_mode =  WB_SYNC_ALL,
526 		.nr_to_write = LONG_MAX,
527 		.range_start = jinode->i_dirty_start,
528 		.range_end = jinode->i_dirty_end,
529         };
530 
531 	return write_cache_pages(mapping, &wbc,
532 				 ext4_journalled_writepage_callback,
533 				 jinode->i_transaction);
534 }
535 
536 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
537 {
538 	int ret;
539 
540 	if (ext4_should_journal_data(jinode->i_vfs_inode))
541 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
542 	else
543 		ret = ext4_normal_submit_inode_data_buffers(jinode);
544 	return ret;
545 }
546 
547 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
548 {
549 	int ret = 0;
550 
551 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
552 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
553 
554 	return ret;
555 }
556 
557 static bool system_going_down(void)
558 {
559 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
560 		|| system_state == SYSTEM_RESTART;
561 }
562 
563 struct ext4_err_translation {
564 	int code;
565 	int errno;
566 };
567 
568 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
569 
570 static struct ext4_err_translation err_translation[] = {
571 	EXT4_ERR_TRANSLATE(EIO),
572 	EXT4_ERR_TRANSLATE(ENOMEM),
573 	EXT4_ERR_TRANSLATE(EFSBADCRC),
574 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
575 	EXT4_ERR_TRANSLATE(ENOSPC),
576 	EXT4_ERR_TRANSLATE(ENOKEY),
577 	EXT4_ERR_TRANSLATE(EROFS),
578 	EXT4_ERR_TRANSLATE(EFBIG),
579 	EXT4_ERR_TRANSLATE(EEXIST),
580 	EXT4_ERR_TRANSLATE(ERANGE),
581 	EXT4_ERR_TRANSLATE(EOVERFLOW),
582 	EXT4_ERR_TRANSLATE(EBUSY),
583 	EXT4_ERR_TRANSLATE(ENOTDIR),
584 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
585 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
586 	EXT4_ERR_TRANSLATE(EFAULT),
587 };
588 
589 static int ext4_errno_to_code(int errno)
590 {
591 	int i;
592 
593 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
594 		if (err_translation[i].errno == errno)
595 			return err_translation[i].code;
596 	return EXT4_ERR_UNKNOWN;
597 }
598 
599 static void save_error_info(struct super_block *sb, int error,
600 			    __u32 ino, __u64 block,
601 			    const char *func, unsigned int line)
602 {
603 	struct ext4_sb_info *sbi = EXT4_SB(sb);
604 
605 	/* We default to EFSCORRUPTED error... */
606 	if (error == 0)
607 		error = EFSCORRUPTED;
608 
609 	spin_lock(&sbi->s_error_lock);
610 	sbi->s_add_error_count++;
611 	sbi->s_last_error_code = error;
612 	sbi->s_last_error_line = line;
613 	sbi->s_last_error_ino = ino;
614 	sbi->s_last_error_block = block;
615 	sbi->s_last_error_func = func;
616 	sbi->s_last_error_time = ktime_get_real_seconds();
617 	if (!sbi->s_first_error_time) {
618 		sbi->s_first_error_code = error;
619 		sbi->s_first_error_line = line;
620 		sbi->s_first_error_ino = ino;
621 		sbi->s_first_error_block = block;
622 		sbi->s_first_error_func = func;
623 		sbi->s_first_error_time = sbi->s_last_error_time;
624 	}
625 	spin_unlock(&sbi->s_error_lock);
626 }
627 
628 /* Deal with the reporting of failure conditions on a filesystem such as
629  * inconsistencies detected or read IO failures.
630  *
631  * On ext2, we can store the error state of the filesystem in the
632  * superblock.  That is not possible on ext4, because we may have other
633  * write ordering constraints on the superblock which prevent us from
634  * writing it out straight away; and given that the journal is about to
635  * be aborted, we can't rely on the current, or future, transactions to
636  * write out the superblock safely.
637  *
638  * We'll just use the jbd2_journal_abort() error code to record an error in
639  * the journal instead.  On recovery, the journal will complain about
640  * that error until we've noted it down and cleared it.
641  *
642  * If force_ro is set, we unconditionally force the filesystem into an
643  * ABORT|READONLY state, unless the error response on the fs has been set to
644  * panic in which case we take the easy way out and panic immediately. This is
645  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
646  * at a critical moment in log management.
647  */
648 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
649 			      __u32 ino, __u64 block,
650 			      const char *func, unsigned int line)
651 {
652 	journal_t *journal = EXT4_SB(sb)->s_journal;
653 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
654 
655 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
656 	if (test_opt(sb, WARN_ON_ERROR))
657 		WARN_ON_ONCE(1);
658 
659 	if (!continue_fs && !sb_rdonly(sb)) {
660 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
661 		if (journal)
662 			jbd2_journal_abort(journal, -EIO);
663 	}
664 
665 	if (!bdev_read_only(sb->s_bdev)) {
666 		save_error_info(sb, error, ino, block, func, line);
667 		/*
668 		 * In case the fs should keep running, we need to writeout
669 		 * superblock through the journal. Due to lock ordering
670 		 * constraints, it may not be safe to do it right here so we
671 		 * defer superblock flushing to a workqueue.
672 		 */
673 		if (continue_fs && journal)
674 			schedule_work(&EXT4_SB(sb)->s_error_work);
675 		else
676 			ext4_commit_super(sb);
677 	}
678 
679 	/*
680 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
681 	 * could panic during 'reboot -f' as the underlying device got already
682 	 * disabled.
683 	 */
684 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
685 		panic("EXT4-fs (device %s): panic forced after error\n",
686 			sb->s_id);
687 	}
688 
689 	if (sb_rdonly(sb) || continue_fs)
690 		return;
691 
692 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
693 	/*
694 	 * Make sure updated value of ->s_mount_flags will be visible before
695 	 * ->s_flags update
696 	 */
697 	smp_wmb();
698 	sb->s_flags |= SB_RDONLY;
699 }
700 
701 static void flush_stashed_error_work(struct work_struct *work)
702 {
703 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
704 						s_error_work);
705 	journal_t *journal = sbi->s_journal;
706 	handle_t *handle;
707 
708 	/*
709 	 * If the journal is still running, we have to write out superblock
710 	 * through the journal to avoid collisions of other journalled sb
711 	 * updates.
712 	 *
713 	 * We use directly jbd2 functions here to avoid recursing back into
714 	 * ext4 error handling code during handling of previous errors.
715 	 */
716 	if (!sb_rdonly(sbi->s_sb) && journal) {
717 		struct buffer_head *sbh = sbi->s_sbh;
718 		handle = jbd2_journal_start(journal, 1);
719 		if (IS_ERR(handle))
720 			goto write_directly;
721 		if (jbd2_journal_get_write_access(handle, sbh)) {
722 			jbd2_journal_stop(handle);
723 			goto write_directly;
724 		}
725 		ext4_update_super(sbi->s_sb);
726 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
727 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
728 				 "superblock detected");
729 			clear_buffer_write_io_error(sbh);
730 			set_buffer_uptodate(sbh);
731 		}
732 
733 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
734 			jbd2_journal_stop(handle);
735 			goto write_directly;
736 		}
737 		jbd2_journal_stop(handle);
738 		ext4_notify_error_sysfs(sbi);
739 		return;
740 	}
741 write_directly:
742 	/*
743 	 * Write through journal failed. Write sb directly to get error info
744 	 * out and hope for the best.
745 	 */
746 	ext4_commit_super(sbi->s_sb);
747 	ext4_notify_error_sysfs(sbi);
748 }
749 
750 #define ext4_error_ratelimit(sb)					\
751 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
752 			     "EXT4-fs error")
753 
754 void __ext4_error(struct super_block *sb, const char *function,
755 		  unsigned int line, bool force_ro, int error, __u64 block,
756 		  const char *fmt, ...)
757 {
758 	struct va_format vaf;
759 	va_list args;
760 
761 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
762 		return;
763 
764 	trace_ext4_error(sb, function, line);
765 	if (ext4_error_ratelimit(sb)) {
766 		va_start(args, fmt);
767 		vaf.fmt = fmt;
768 		vaf.va = &args;
769 		printk(KERN_CRIT
770 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
771 		       sb->s_id, function, line, current->comm, &vaf);
772 		va_end(args);
773 	}
774 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
775 
776 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
777 }
778 
779 void __ext4_error_inode(struct inode *inode, const char *function,
780 			unsigned int line, ext4_fsblk_t block, int error,
781 			const char *fmt, ...)
782 {
783 	va_list args;
784 	struct va_format vaf;
785 
786 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
787 		return;
788 
789 	trace_ext4_error(inode->i_sb, function, line);
790 	if (ext4_error_ratelimit(inode->i_sb)) {
791 		va_start(args, fmt);
792 		vaf.fmt = fmt;
793 		vaf.va = &args;
794 		if (block)
795 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
796 			       "inode #%lu: block %llu: comm %s: %pV\n",
797 			       inode->i_sb->s_id, function, line, inode->i_ino,
798 			       block, current->comm, &vaf);
799 		else
800 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
801 			       "inode #%lu: comm %s: %pV\n",
802 			       inode->i_sb->s_id, function, line, inode->i_ino,
803 			       current->comm, &vaf);
804 		va_end(args);
805 	}
806 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
807 
808 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
809 			  function, line);
810 }
811 
812 void __ext4_error_file(struct file *file, const char *function,
813 		       unsigned int line, ext4_fsblk_t block,
814 		       const char *fmt, ...)
815 {
816 	va_list args;
817 	struct va_format vaf;
818 	struct inode *inode = file_inode(file);
819 	char pathname[80], *path;
820 
821 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
822 		return;
823 
824 	trace_ext4_error(inode->i_sb, function, line);
825 	if (ext4_error_ratelimit(inode->i_sb)) {
826 		path = file_path(file, pathname, sizeof(pathname));
827 		if (IS_ERR(path))
828 			path = "(unknown)";
829 		va_start(args, fmt);
830 		vaf.fmt = fmt;
831 		vaf.va = &args;
832 		if (block)
833 			printk(KERN_CRIT
834 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
835 			       "block %llu: comm %s: path %s: %pV\n",
836 			       inode->i_sb->s_id, function, line, inode->i_ino,
837 			       block, current->comm, path, &vaf);
838 		else
839 			printk(KERN_CRIT
840 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
841 			       "comm %s: path %s: %pV\n",
842 			       inode->i_sb->s_id, function, line, inode->i_ino,
843 			       current->comm, path, &vaf);
844 		va_end(args);
845 	}
846 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
847 
848 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
849 			  function, line);
850 }
851 
852 const char *ext4_decode_error(struct super_block *sb, int errno,
853 			      char nbuf[16])
854 {
855 	char *errstr = NULL;
856 
857 	switch (errno) {
858 	case -EFSCORRUPTED:
859 		errstr = "Corrupt filesystem";
860 		break;
861 	case -EFSBADCRC:
862 		errstr = "Filesystem failed CRC";
863 		break;
864 	case -EIO:
865 		errstr = "IO failure";
866 		break;
867 	case -ENOMEM:
868 		errstr = "Out of memory";
869 		break;
870 	case -EROFS:
871 		if (!sb || (EXT4_SB(sb)->s_journal &&
872 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
873 			errstr = "Journal has aborted";
874 		else
875 			errstr = "Readonly filesystem";
876 		break;
877 	default:
878 		/* If the caller passed in an extra buffer for unknown
879 		 * errors, textualise them now.  Else we just return
880 		 * NULL. */
881 		if (nbuf) {
882 			/* Check for truncated error codes... */
883 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
884 				errstr = nbuf;
885 		}
886 		break;
887 	}
888 
889 	return errstr;
890 }
891 
892 /* __ext4_std_error decodes expected errors from journaling functions
893  * automatically and invokes the appropriate error response.  */
894 
895 void __ext4_std_error(struct super_block *sb, const char *function,
896 		      unsigned int line, int errno)
897 {
898 	char nbuf[16];
899 	const char *errstr;
900 
901 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
902 		return;
903 
904 	/* Special case: if the error is EROFS, and we're not already
905 	 * inside a transaction, then there's really no point in logging
906 	 * an error. */
907 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
908 		return;
909 
910 	if (ext4_error_ratelimit(sb)) {
911 		errstr = ext4_decode_error(sb, errno, nbuf);
912 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
913 		       sb->s_id, function, line, errstr);
914 	}
915 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
916 
917 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
918 }
919 
920 void __ext4_msg(struct super_block *sb,
921 		const char *prefix, const char *fmt, ...)
922 {
923 	struct va_format vaf;
924 	va_list args;
925 
926 	if (sb) {
927 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
928 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
929 				  "EXT4-fs"))
930 			return;
931 	}
932 
933 	va_start(args, fmt);
934 	vaf.fmt = fmt;
935 	vaf.va = &args;
936 	if (sb)
937 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
938 	else
939 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
940 	va_end(args);
941 }
942 
943 static int ext4_warning_ratelimit(struct super_block *sb)
944 {
945 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
946 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
947 			    "EXT4-fs warning");
948 }
949 
950 void __ext4_warning(struct super_block *sb, const char *function,
951 		    unsigned int line, const char *fmt, ...)
952 {
953 	struct va_format vaf;
954 	va_list args;
955 
956 	if (!ext4_warning_ratelimit(sb))
957 		return;
958 
959 	va_start(args, fmt);
960 	vaf.fmt = fmt;
961 	vaf.va = &args;
962 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
963 	       sb->s_id, function, line, &vaf);
964 	va_end(args);
965 }
966 
967 void __ext4_warning_inode(const struct inode *inode, const char *function,
968 			  unsigned int line, const char *fmt, ...)
969 {
970 	struct va_format vaf;
971 	va_list args;
972 
973 	if (!ext4_warning_ratelimit(inode->i_sb))
974 		return;
975 
976 	va_start(args, fmt);
977 	vaf.fmt = fmt;
978 	vaf.va = &args;
979 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
980 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
981 	       function, line, inode->i_ino, current->comm, &vaf);
982 	va_end(args);
983 }
984 
985 void __ext4_grp_locked_error(const char *function, unsigned int line,
986 			     struct super_block *sb, ext4_group_t grp,
987 			     unsigned long ino, ext4_fsblk_t block,
988 			     const char *fmt, ...)
989 __releases(bitlock)
990 __acquires(bitlock)
991 {
992 	struct va_format vaf;
993 	va_list args;
994 
995 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
996 		return;
997 
998 	trace_ext4_error(sb, function, line);
999 	if (ext4_error_ratelimit(sb)) {
1000 		va_start(args, fmt);
1001 		vaf.fmt = fmt;
1002 		vaf.va = &args;
1003 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1004 		       sb->s_id, function, line, grp);
1005 		if (ino)
1006 			printk(KERN_CONT "inode %lu: ", ino);
1007 		if (block)
1008 			printk(KERN_CONT "block %llu:",
1009 			       (unsigned long long) block);
1010 		printk(KERN_CONT "%pV\n", &vaf);
1011 		va_end(args);
1012 	}
1013 
1014 	if (test_opt(sb, ERRORS_CONT)) {
1015 		if (test_opt(sb, WARN_ON_ERROR))
1016 			WARN_ON_ONCE(1);
1017 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1018 		if (!bdev_read_only(sb->s_bdev)) {
1019 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1020 					line);
1021 			schedule_work(&EXT4_SB(sb)->s_error_work);
1022 		}
1023 		return;
1024 	}
1025 	ext4_unlock_group(sb, grp);
1026 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1027 	/*
1028 	 * We only get here in the ERRORS_RO case; relocking the group
1029 	 * may be dangerous, but nothing bad will happen since the
1030 	 * filesystem will have already been marked read/only and the
1031 	 * journal has been aborted.  We return 1 as a hint to callers
1032 	 * who might what to use the return value from
1033 	 * ext4_grp_locked_error() to distinguish between the
1034 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1035 	 * aggressively from the ext4 function in question, with a
1036 	 * more appropriate error code.
1037 	 */
1038 	ext4_lock_group(sb, grp);
1039 	return;
1040 }
1041 
1042 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1043 				     ext4_group_t group,
1044 				     unsigned int flags)
1045 {
1046 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1047 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1048 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1049 	int ret;
1050 
1051 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1052 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1053 					    &grp->bb_state);
1054 		if (!ret)
1055 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1056 					   grp->bb_free);
1057 	}
1058 
1059 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1060 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1061 					    &grp->bb_state);
1062 		if (!ret && gdp) {
1063 			int count;
1064 
1065 			count = ext4_free_inodes_count(sb, gdp);
1066 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1067 					   count);
1068 		}
1069 	}
1070 }
1071 
1072 void ext4_update_dynamic_rev(struct super_block *sb)
1073 {
1074 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1075 
1076 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1077 		return;
1078 
1079 	ext4_warning(sb,
1080 		     "updating to rev %d because of new feature flag, "
1081 		     "running e2fsck is recommended",
1082 		     EXT4_DYNAMIC_REV);
1083 
1084 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1085 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1086 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1087 	/* leave es->s_feature_*compat flags alone */
1088 	/* es->s_uuid will be set by e2fsck if empty */
1089 
1090 	/*
1091 	 * The rest of the superblock fields should be zero, and if not it
1092 	 * means they are likely already in use, so leave them alone.  We
1093 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1094 	 */
1095 }
1096 
1097 /*
1098  * Open the external journal device
1099  */
1100 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1101 {
1102 	struct block_device *bdev;
1103 
1104 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1105 	if (IS_ERR(bdev))
1106 		goto fail;
1107 	return bdev;
1108 
1109 fail:
1110 	ext4_msg(sb, KERN_ERR,
1111 		 "failed to open journal device unknown-block(%u,%u) %ld",
1112 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1113 	return NULL;
1114 }
1115 
1116 /*
1117  * Release the journal device
1118  */
1119 static void ext4_blkdev_put(struct block_device *bdev)
1120 {
1121 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1122 }
1123 
1124 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1125 {
1126 	struct block_device *bdev;
1127 	bdev = sbi->s_journal_bdev;
1128 	if (bdev) {
1129 		ext4_blkdev_put(bdev);
1130 		sbi->s_journal_bdev = NULL;
1131 	}
1132 }
1133 
1134 static inline struct inode *orphan_list_entry(struct list_head *l)
1135 {
1136 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1137 }
1138 
1139 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1140 {
1141 	struct list_head *l;
1142 
1143 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1144 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1145 
1146 	printk(KERN_ERR "sb_info orphan list:\n");
1147 	list_for_each(l, &sbi->s_orphan) {
1148 		struct inode *inode = orphan_list_entry(l);
1149 		printk(KERN_ERR "  "
1150 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1151 		       inode->i_sb->s_id, inode->i_ino, inode,
1152 		       inode->i_mode, inode->i_nlink,
1153 		       NEXT_ORPHAN(inode));
1154 	}
1155 }
1156 
1157 #ifdef CONFIG_QUOTA
1158 static int ext4_quota_off(struct super_block *sb, int type);
1159 
1160 static inline void ext4_quota_off_umount(struct super_block *sb)
1161 {
1162 	int type;
1163 
1164 	/* Use our quota_off function to clear inode flags etc. */
1165 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1166 		ext4_quota_off(sb, type);
1167 }
1168 
1169 /*
1170  * This is a helper function which is used in the mount/remount
1171  * codepaths (which holds s_umount) to fetch the quota file name.
1172  */
1173 static inline char *get_qf_name(struct super_block *sb,
1174 				struct ext4_sb_info *sbi,
1175 				int type)
1176 {
1177 	return rcu_dereference_protected(sbi->s_qf_names[type],
1178 					 lockdep_is_held(&sb->s_umount));
1179 }
1180 #else
1181 static inline void ext4_quota_off_umount(struct super_block *sb)
1182 {
1183 }
1184 #endif
1185 
1186 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1187 {
1188 	ext4_fsblk_t block;
1189 	int err;
1190 
1191 	block = ext4_count_free_clusters(sbi->s_sb);
1192 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1193 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1194 				  GFP_KERNEL);
1195 	if (!err) {
1196 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1197 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1198 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1199 					  GFP_KERNEL);
1200 	}
1201 	if (!err)
1202 		err = percpu_counter_init(&sbi->s_dirs_counter,
1203 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1204 	if (!err)
1205 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1206 					  GFP_KERNEL);
1207 	if (!err)
1208 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1209 					  GFP_KERNEL);
1210 	if (!err)
1211 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1212 
1213 	if (err)
1214 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1215 
1216 	return err;
1217 }
1218 
1219 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1220 {
1221 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1222 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1223 	percpu_counter_destroy(&sbi->s_dirs_counter);
1224 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1225 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1226 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1227 }
1228 
1229 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1230 {
1231 	struct buffer_head **group_desc;
1232 	int i;
1233 
1234 	rcu_read_lock();
1235 	group_desc = rcu_dereference(sbi->s_group_desc);
1236 	for (i = 0; i < sbi->s_gdb_count; i++)
1237 		brelse(group_desc[i]);
1238 	kvfree(group_desc);
1239 	rcu_read_unlock();
1240 }
1241 
1242 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1243 {
1244 	struct flex_groups **flex_groups;
1245 	int i;
1246 
1247 	rcu_read_lock();
1248 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1249 	if (flex_groups) {
1250 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1251 			kvfree(flex_groups[i]);
1252 		kvfree(flex_groups);
1253 	}
1254 	rcu_read_unlock();
1255 }
1256 
1257 static void ext4_put_super(struct super_block *sb)
1258 {
1259 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1260 	struct ext4_super_block *es = sbi->s_es;
1261 	int aborted = 0;
1262 	int i, err;
1263 
1264 	/*
1265 	 * Unregister sysfs before destroying jbd2 journal.
1266 	 * Since we could still access attr_journal_task attribute via sysfs
1267 	 * path which could have sbi->s_journal->j_task as NULL
1268 	 * Unregister sysfs before flush sbi->s_error_work.
1269 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1270 	 * read metadata verify failed then will queue error work.
1271 	 * flush_stashed_error_work will call start_this_handle may trigger
1272 	 * BUG_ON.
1273 	 */
1274 	ext4_unregister_sysfs(sb);
1275 
1276 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1277 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1278 			 &sb->s_uuid);
1279 
1280 	ext4_unregister_li_request(sb);
1281 	ext4_quota_off_umount(sb);
1282 
1283 	flush_work(&sbi->s_error_work);
1284 	destroy_workqueue(sbi->rsv_conversion_wq);
1285 	ext4_release_orphan_info(sb);
1286 
1287 	if (sbi->s_journal) {
1288 		aborted = is_journal_aborted(sbi->s_journal);
1289 		err = jbd2_journal_destroy(sbi->s_journal);
1290 		sbi->s_journal = NULL;
1291 		if ((err < 0) && !aborted) {
1292 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1293 		}
1294 	}
1295 
1296 	ext4_es_unregister_shrinker(sbi);
1297 	timer_shutdown_sync(&sbi->s_err_report);
1298 	ext4_release_system_zone(sb);
1299 	ext4_mb_release(sb);
1300 	ext4_ext_release(sb);
1301 
1302 	if (!sb_rdonly(sb) && !aborted) {
1303 		ext4_clear_feature_journal_needs_recovery(sb);
1304 		ext4_clear_feature_orphan_present(sb);
1305 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1306 	}
1307 	if (!sb_rdonly(sb))
1308 		ext4_commit_super(sb);
1309 
1310 	ext4_group_desc_free(sbi);
1311 	ext4_flex_groups_free(sbi);
1312 	ext4_percpu_param_destroy(sbi);
1313 #ifdef CONFIG_QUOTA
1314 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1315 		kfree(get_qf_name(sb, sbi, i));
1316 #endif
1317 
1318 	/* Debugging code just in case the in-memory inode orphan list
1319 	 * isn't empty.  The on-disk one can be non-empty if we've
1320 	 * detected an error and taken the fs readonly, but the
1321 	 * in-memory list had better be clean by this point. */
1322 	if (!list_empty(&sbi->s_orphan))
1323 		dump_orphan_list(sb, sbi);
1324 	ASSERT(list_empty(&sbi->s_orphan));
1325 
1326 	sync_blockdev(sb->s_bdev);
1327 	invalidate_bdev(sb->s_bdev);
1328 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1329 		/*
1330 		 * Invalidate the journal device's buffers.  We don't want them
1331 		 * floating about in memory - the physical journal device may
1332 		 * hotswapped, and it breaks the `ro-after' testing code.
1333 		 */
1334 		sync_blockdev(sbi->s_journal_bdev);
1335 		invalidate_bdev(sbi->s_journal_bdev);
1336 		ext4_blkdev_remove(sbi);
1337 	}
1338 
1339 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1340 	sbi->s_ea_inode_cache = NULL;
1341 
1342 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1343 	sbi->s_ea_block_cache = NULL;
1344 
1345 	ext4_stop_mmpd(sbi);
1346 
1347 	brelse(sbi->s_sbh);
1348 	sb->s_fs_info = NULL;
1349 	/*
1350 	 * Now that we are completely done shutting down the
1351 	 * superblock, we need to actually destroy the kobject.
1352 	 */
1353 	kobject_put(&sbi->s_kobj);
1354 	wait_for_completion(&sbi->s_kobj_unregister);
1355 	if (sbi->s_chksum_driver)
1356 		crypto_free_shash(sbi->s_chksum_driver);
1357 	kfree(sbi->s_blockgroup_lock);
1358 	fs_put_dax(sbi->s_daxdev, NULL);
1359 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1360 #if IS_ENABLED(CONFIG_UNICODE)
1361 	utf8_unload(sb->s_encoding);
1362 #endif
1363 	kfree(sbi);
1364 }
1365 
1366 static struct kmem_cache *ext4_inode_cachep;
1367 
1368 /*
1369  * Called inside transaction, so use GFP_NOFS
1370  */
1371 static struct inode *ext4_alloc_inode(struct super_block *sb)
1372 {
1373 	struct ext4_inode_info *ei;
1374 
1375 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1376 	if (!ei)
1377 		return NULL;
1378 
1379 	inode_set_iversion(&ei->vfs_inode, 1);
1380 	ei->i_flags = 0;
1381 	spin_lock_init(&ei->i_raw_lock);
1382 	ei->i_prealloc_node = RB_ROOT;
1383 	atomic_set(&ei->i_prealloc_active, 0);
1384 	rwlock_init(&ei->i_prealloc_lock);
1385 	ext4_es_init_tree(&ei->i_es_tree);
1386 	rwlock_init(&ei->i_es_lock);
1387 	INIT_LIST_HEAD(&ei->i_es_list);
1388 	ei->i_es_all_nr = 0;
1389 	ei->i_es_shk_nr = 0;
1390 	ei->i_es_shrink_lblk = 0;
1391 	ei->i_reserved_data_blocks = 0;
1392 	spin_lock_init(&(ei->i_block_reservation_lock));
1393 	ext4_init_pending_tree(&ei->i_pending_tree);
1394 #ifdef CONFIG_QUOTA
1395 	ei->i_reserved_quota = 0;
1396 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1397 #endif
1398 	ei->jinode = NULL;
1399 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1400 	spin_lock_init(&ei->i_completed_io_lock);
1401 	ei->i_sync_tid = 0;
1402 	ei->i_datasync_tid = 0;
1403 	atomic_set(&ei->i_unwritten, 0);
1404 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1405 	ext4_fc_init_inode(&ei->vfs_inode);
1406 	mutex_init(&ei->i_fc_lock);
1407 	return &ei->vfs_inode;
1408 }
1409 
1410 static int ext4_drop_inode(struct inode *inode)
1411 {
1412 	int drop = generic_drop_inode(inode);
1413 
1414 	if (!drop)
1415 		drop = fscrypt_drop_inode(inode);
1416 
1417 	trace_ext4_drop_inode(inode, drop);
1418 	return drop;
1419 }
1420 
1421 static void ext4_free_in_core_inode(struct inode *inode)
1422 {
1423 	fscrypt_free_inode(inode);
1424 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1425 		pr_warn("%s: inode %ld still in fc list",
1426 			__func__, inode->i_ino);
1427 	}
1428 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1429 }
1430 
1431 static void ext4_destroy_inode(struct inode *inode)
1432 {
1433 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1434 		ext4_msg(inode->i_sb, KERN_ERR,
1435 			 "Inode %lu (%p): orphan list check failed!",
1436 			 inode->i_ino, EXT4_I(inode));
1437 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1438 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1439 				true);
1440 		dump_stack();
1441 	}
1442 
1443 	if (EXT4_I(inode)->i_reserved_data_blocks)
1444 		ext4_msg(inode->i_sb, KERN_ERR,
1445 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1446 			 inode->i_ino, EXT4_I(inode),
1447 			 EXT4_I(inode)->i_reserved_data_blocks);
1448 }
1449 
1450 static void init_once(void *foo)
1451 {
1452 	struct ext4_inode_info *ei = foo;
1453 
1454 	INIT_LIST_HEAD(&ei->i_orphan);
1455 	init_rwsem(&ei->xattr_sem);
1456 	init_rwsem(&ei->i_data_sem);
1457 	inode_init_once(&ei->vfs_inode);
1458 	ext4_fc_init_inode(&ei->vfs_inode);
1459 }
1460 
1461 static int __init init_inodecache(void)
1462 {
1463 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1464 				sizeof(struct ext4_inode_info), 0,
1465 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1466 					SLAB_ACCOUNT),
1467 				offsetof(struct ext4_inode_info, i_data),
1468 				sizeof_field(struct ext4_inode_info, i_data),
1469 				init_once);
1470 	if (ext4_inode_cachep == NULL)
1471 		return -ENOMEM;
1472 	return 0;
1473 }
1474 
1475 static void destroy_inodecache(void)
1476 {
1477 	/*
1478 	 * Make sure all delayed rcu free inodes are flushed before we
1479 	 * destroy cache.
1480 	 */
1481 	rcu_barrier();
1482 	kmem_cache_destroy(ext4_inode_cachep);
1483 }
1484 
1485 void ext4_clear_inode(struct inode *inode)
1486 {
1487 	ext4_fc_del(inode);
1488 	invalidate_inode_buffers(inode);
1489 	clear_inode(inode);
1490 	ext4_discard_preallocations(inode, 0);
1491 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1492 	dquot_drop(inode);
1493 	if (EXT4_I(inode)->jinode) {
1494 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1495 					       EXT4_I(inode)->jinode);
1496 		jbd2_free_inode(EXT4_I(inode)->jinode);
1497 		EXT4_I(inode)->jinode = NULL;
1498 	}
1499 	fscrypt_put_encryption_info(inode);
1500 	fsverity_cleanup_inode(inode);
1501 }
1502 
1503 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1504 					u64 ino, u32 generation)
1505 {
1506 	struct inode *inode;
1507 
1508 	/*
1509 	 * Currently we don't know the generation for parent directory, so
1510 	 * a generation of 0 means "accept any"
1511 	 */
1512 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1513 	if (IS_ERR(inode))
1514 		return ERR_CAST(inode);
1515 	if (generation && inode->i_generation != generation) {
1516 		iput(inode);
1517 		return ERR_PTR(-ESTALE);
1518 	}
1519 
1520 	return inode;
1521 }
1522 
1523 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1524 					int fh_len, int fh_type)
1525 {
1526 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1527 				    ext4_nfs_get_inode);
1528 }
1529 
1530 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1531 					int fh_len, int fh_type)
1532 {
1533 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1534 				    ext4_nfs_get_inode);
1535 }
1536 
1537 static int ext4_nfs_commit_metadata(struct inode *inode)
1538 {
1539 	struct writeback_control wbc = {
1540 		.sync_mode = WB_SYNC_ALL
1541 	};
1542 
1543 	trace_ext4_nfs_commit_metadata(inode);
1544 	return ext4_write_inode(inode, &wbc);
1545 }
1546 
1547 #ifdef CONFIG_QUOTA
1548 static const char * const quotatypes[] = INITQFNAMES;
1549 #define QTYPE2NAME(t) (quotatypes[t])
1550 
1551 static int ext4_write_dquot(struct dquot *dquot);
1552 static int ext4_acquire_dquot(struct dquot *dquot);
1553 static int ext4_release_dquot(struct dquot *dquot);
1554 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1555 static int ext4_write_info(struct super_block *sb, int type);
1556 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1557 			 const struct path *path);
1558 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1559 			       size_t len, loff_t off);
1560 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1561 				const char *data, size_t len, loff_t off);
1562 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1563 			     unsigned int flags);
1564 
1565 static struct dquot **ext4_get_dquots(struct inode *inode)
1566 {
1567 	return EXT4_I(inode)->i_dquot;
1568 }
1569 
1570 static const struct dquot_operations ext4_quota_operations = {
1571 	.get_reserved_space	= ext4_get_reserved_space,
1572 	.write_dquot		= ext4_write_dquot,
1573 	.acquire_dquot		= ext4_acquire_dquot,
1574 	.release_dquot		= ext4_release_dquot,
1575 	.mark_dirty		= ext4_mark_dquot_dirty,
1576 	.write_info		= ext4_write_info,
1577 	.alloc_dquot		= dquot_alloc,
1578 	.destroy_dquot		= dquot_destroy,
1579 	.get_projid		= ext4_get_projid,
1580 	.get_inode_usage	= ext4_get_inode_usage,
1581 	.get_next_id		= dquot_get_next_id,
1582 };
1583 
1584 static const struct quotactl_ops ext4_qctl_operations = {
1585 	.quota_on	= ext4_quota_on,
1586 	.quota_off	= ext4_quota_off,
1587 	.quota_sync	= dquot_quota_sync,
1588 	.get_state	= dquot_get_state,
1589 	.set_info	= dquot_set_dqinfo,
1590 	.get_dqblk	= dquot_get_dqblk,
1591 	.set_dqblk	= dquot_set_dqblk,
1592 	.get_nextdqblk	= dquot_get_next_dqblk,
1593 };
1594 #endif
1595 
1596 static const struct super_operations ext4_sops = {
1597 	.alloc_inode	= ext4_alloc_inode,
1598 	.free_inode	= ext4_free_in_core_inode,
1599 	.destroy_inode	= ext4_destroy_inode,
1600 	.write_inode	= ext4_write_inode,
1601 	.dirty_inode	= ext4_dirty_inode,
1602 	.drop_inode	= ext4_drop_inode,
1603 	.evict_inode	= ext4_evict_inode,
1604 	.put_super	= ext4_put_super,
1605 	.sync_fs	= ext4_sync_fs,
1606 	.freeze_fs	= ext4_freeze,
1607 	.unfreeze_fs	= ext4_unfreeze,
1608 	.statfs		= ext4_statfs,
1609 	.show_options	= ext4_show_options,
1610 #ifdef CONFIG_QUOTA
1611 	.quota_read	= ext4_quota_read,
1612 	.quota_write	= ext4_quota_write,
1613 	.get_dquots	= ext4_get_dquots,
1614 #endif
1615 };
1616 
1617 static const struct export_operations ext4_export_ops = {
1618 	.fh_to_dentry = ext4_fh_to_dentry,
1619 	.fh_to_parent = ext4_fh_to_parent,
1620 	.get_parent = ext4_get_parent,
1621 	.commit_metadata = ext4_nfs_commit_metadata,
1622 };
1623 
1624 enum {
1625 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1626 	Opt_resgid, Opt_resuid, Opt_sb,
1627 	Opt_nouid32, Opt_debug, Opt_removed,
1628 	Opt_user_xattr, Opt_acl,
1629 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1630 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1631 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1632 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1633 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1634 	Opt_inlinecrypt,
1635 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1636 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1637 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1638 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1639 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1640 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1641 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1642 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1643 	Opt_dioread_nolock, Opt_dioread_lock,
1644 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1645 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1646 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1647 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1648 #ifdef CONFIG_EXT4_DEBUG
1649 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1650 #endif
1651 };
1652 
1653 static const struct constant_table ext4_param_errors[] = {
1654 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1655 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1656 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1657 	{}
1658 };
1659 
1660 static const struct constant_table ext4_param_data[] = {
1661 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1662 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1663 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1664 	{}
1665 };
1666 
1667 static const struct constant_table ext4_param_data_err[] = {
1668 	{"abort",	Opt_data_err_abort},
1669 	{"ignore",	Opt_data_err_ignore},
1670 	{}
1671 };
1672 
1673 static const struct constant_table ext4_param_jqfmt[] = {
1674 	{"vfsold",	QFMT_VFS_OLD},
1675 	{"vfsv0",	QFMT_VFS_V0},
1676 	{"vfsv1",	QFMT_VFS_V1},
1677 	{}
1678 };
1679 
1680 static const struct constant_table ext4_param_dax[] = {
1681 	{"always",	Opt_dax_always},
1682 	{"inode",	Opt_dax_inode},
1683 	{"never",	Opt_dax_never},
1684 	{}
1685 };
1686 
1687 /* String parameter that allows empty argument */
1688 #define fsparam_string_empty(NAME, OPT) \
1689 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1690 
1691 /*
1692  * Mount option specification
1693  * We don't use fsparam_flag_no because of the way we set the
1694  * options and the way we show them in _ext4_show_options(). To
1695  * keep the changes to a minimum, let's keep the negative options
1696  * separate for now.
1697  */
1698 static const struct fs_parameter_spec ext4_param_specs[] = {
1699 	fsparam_flag	("bsddf",		Opt_bsd_df),
1700 	fsparam_flag	("minixdf",		Opt_minix_df),
1701 	fsparam_flag	("grpid",		Opt_grpid),
1702 	fsparam_flag	("bsdgroups",		Opt_grpid),
1703 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1704 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1705 	fsparam_u32	("resgid",		Opt_resgid),
1706 	fsparam_u32	("resuid",		Opt_resuid),
1707 	fsparam_u32	("sb",			Opt_sb),
1708 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1709 	fsparam_flag	("nouid32",		Opt_nouid32),
1710 	fsparam_flag	("debug",		Opt_debug),
1711 	fsparam_flag	("oldalloc",		Opt_removed),
1712 	fsparam_flag	("orlov",		Opt_removed),
1713 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1714 	fsparam_flag	("acl",			Opt_acl),
1715 	fsparam_flag	("norecovery",		Opt_noload),
1716 	fsparam_flag	("noload",		Opt_noload),
1717 	fsparam_flag	("bh",			Opt_removed),
1718 	fsparam_flag	("nobh",		Opt_removed),
1719 	fsparam_u32	("commit",		Opt_commit),
1720 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1721 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1722 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1723 	fsparam_bdev	("journal_path",	Opt_journal_path),
1724 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1725 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1726 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1727 	fsparam_flag	("abort",		Opt_abort),
1728 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1729 	fsparam_enum	("data_err",		Opt_data_err,
1730 						ext4_param_data_err),
1731 	fsparam_string_empty
1732 			("usrjquota",		Opt_usrjquota),
1733 	fsparam_string_empty
1734 			("grpjquota",		Opt_grpjquota),
1735 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1736 	fsparam_flag	("grpquota",		Opt_grpquota),
1737 	fsparam_flag	("quota",		Opt_quota),
1738 	fsparam_flag	("noquota",		Opt_noquota),
1739 	fsparam_flag	("usrquota",		Opt_usrquota),
1740 	fsparam_flag	("prjquota",		Opt_prjquota),
1741 	fsparam_flag	("barrier",		Opt_barrier),
1742 	fsparam_u32	("barrier",		Opt_barrier),
1743 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1744 	fsparam_flag	("i_version",		Opt_removed),
1745 	fsparam_flag	("dax",			Opt_dax),
1746 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1747 	fsparam_u32	("stripe",		Opt_stripe),
1748 	fsparam_flag	("delalloc",		Opt_delalloc),
1749 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1750 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1751 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1752 	fsparam_u32	("debug_want_extra_isize",
1753 						Opt_debug_want_extra_isize),
1754 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1755 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1756 	fsparam_flag	("block_validity",	Opt_block_validity),
1757 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1758 	fsparam_u32	("inode_readahead_blks",
1759 						Opt_inode_readahead_blks),
1760 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1761 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1762 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1763 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1764 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1765 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1766 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1767 	fsparam_flag	("discard",		Opt_discard),
1768 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1769 	fsparam_u32	("init_itable",		Opt_init_itable),
1770 	fsparam_flag	("init_itable",		Opt_init_itable),
1771 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1772 #ifdef CONFIG_EXT4_DEBUG
1773 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1774 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1775 #endif
1776 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1777 	fsparam_flag	("test_dummy_encryption",
1778 						Opt_test_dummy_encryption),
1779 	fsparam_string	("test_dummy_encryption",
1780 						Opt_test_dummy_encryption),
1781 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1782 	fsparam_flag	("nombcache",		Opt_nombcache),
1783 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1784 	fsparam_flag	("prefetch_block_bitmaps",
1785 						Opt_removed),
1786 	fsparam_flag	("no_prefetch_block_bitmaps",
1787 						Opt_no_prefetch_block_bitmaps),
1788 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1789 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1790 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1791 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1792 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1793 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1794 	{}
1795 };
1796 
1797 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1798 
1799 #define MOPT_SET	0x0001
1800 #define MOPT_CLEAR	0x0002
1801 #define MOPT_NOSUPPORT	0x0004
1802 #define MOPT_EXPLICIT	0x0008
1803 #ifdef CONFIG_QUOTA
1804 #define MOPT_Q		0
1805 #define MOPT_QFMT	0x0010
1806 #else
1807 #define MOPT_Q		MOPT_NOSUPPORT
1808 #define MOPT_QFMT	MOPT_NOSUPPORT
1809 #endif
1810 #define MOPT_NO_EXT2	0x0020
1811 #define MOPT_NO_EXT3	0x0040
1812 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1813 #define MOPT_SKIP	0x0080
1814 #define	MOPT_2		0x0100
1815 
1816 static const struct mount_opts {
1817 	int	token;
1818 	int	mount_opt;
1819 	int	flags;
1820 } ext4_mount_opts[] = {
1821 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1822 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1823 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1824 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1825 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1826 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1827 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1828 	 MOPT_EXT4_ONLY | MOPT_SET},
1829 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1830 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1831 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1832 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1833 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1834 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1835 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1836 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1837 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1838 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1839 	{Opt_commit, 0, MOPT_NO_EXT2},
1840 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1841 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1842 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1843 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1844 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1845 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1846 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1847 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1848 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1849 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1850 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1851 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1852 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1853 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1854 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1855 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1856 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1857 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1858 	{Opt_data, 0, MOPT_NO_EXT2},
1859 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1860 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1861 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1862 #else
1863 	{Opt_acl, 0, MOPT_NOSUPPORT},
1864 #endif
1865 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1866 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1867 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1868 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1869 							MOPT_SET | MOPT_Q},
1870 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1871 							MOPT_SET | MOPT_Q},
1872 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1873 							MOPT_SET | MOPT_Q},
1874 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1875 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1876 							MOPT_CLEAR | MOPT_Q},
1877 	{Opt_usrjquota, 0, MOPT_Q},
1878 	{Opt_grpjquota, 0, MOPT_Q},
1879 	{Opt_jqfmt, 0, MOPT_QFMT},
1880 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1881 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1882 	 MOPT_SET},
1883 #ifdef CONFIG_EXT4_DEBUG
1884 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1885 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1886 #endif
1887 	{Opt_err, 0, 0}
1888 };
1889 
1890 #if IS_ENABLED(CONFIG_UNICODE)
1891 static const struct ext4_sb_encodings {
1892 	__u16 magic;
1893 	char *name;
1894 	unsigned int version;
1895 } ext4_sb_encoding_map[] = {
1896 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1897 };
1898 
1899 static const struct ext4_sb_encodings *
1900 ext4_sb_read_encoding(const struct ext4_super_block *es)
1901 {
1902 	__u16 magic = le16_to_cpu(es->s_encoding);
1903 	int i;
1904 
1905 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1906 		if (magic == ext4_sb_encoding_map[i].magic)
1907 			return &ext4_sb_encoding_map[i];
1908 
1909 	return NULL;
1910 }
1911 #endif
1912 
1913 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1914 #define EXT4_SPEC_JQFMT				(1 <<  1)
1915 #define EXT4_SPEC_DATAJ				(1 <<  2)
1916 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1917 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1918 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1919 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1920 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1921 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1922 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1923 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1924 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1925 #define EXT4_SPEC_s_stripe			(1 << 13)
1926 #define EXT4_SPEC_s_resuid			(1 << 14)
1927 #define EXT4_SPEC_s_resgid			(1 << 15)
1928 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1929 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1930 #define EXT4_SPEC_s_sb_block			(1 << 18)
1931 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1932 
1933 struct ext4_fs_context {
1934 	char		*s_qf_names[EXT4_MAXQUOTAS];
1935 	struct fscrypt_dummy_policy dummy_enc_policy;
1936 	int		s_jquota_fmt;	/* Format of quota to use */
1937 #ifdef CONFIG_EXT4_DEBUG
1938 	int s_fc_debug_max_replay;
1939 #endif
1940 	unsigned short	qname_spec;
1941 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1942 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1943 	unsigned long	journal_devnum;
1944 	unsigned long	s_commit_interval;
1945 	unsigned long	s_stripe;
1946 	unsigned int	s_inode_readahead_blks;
1947 	unsigned int	s_want_extra_isize;
1948 	unsigned int	s_li_wait_mult;
1949 	unsigned int	s_max_dir_size_kb;
1950 	unsigned int	journal_ioprio;
1951 	unsigned int	vals_s_mount_opt;
1952 	unsigned int	mask_s_mount_opt;
1953 	unsigned int	vals_s_mount_opt2;
1954 	unsigned int	mask_s_mount_opt2;
1955 	unsigned long	vals_s_mount_flags;
1956 	unsigned long	mask_s_mount_flags;
1957 	unsigned int	opt_flags;	/* MOPT flags */
1958 	unsigned int	spec;
1959 	u32		s_max_batch_time;
1960 	u32		s_min_batch_time;
1961 	kuid_t		s_resuid;
1962 	kgid_t		s_resgid;
1963 	ext4_fsblk_t	s_sb_block;
1964 };
1965 
1966 static void ext4_fc_free(struct fs_context *fc)
1967 {
1968 	struct ext4_fs_context *ctx = fc->fs_private;
1969 	int i;
1970 
1971 	if (!ctx)
1972 		return;
1973 
1974 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1975 		kfree(ctx->s_qf_names[i]);
1976 
1977 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1978 	kfree(ctx);
1979 }
1980 
1981 int ext4_init_fs_context(struct fs_context *fc)
1982 {
1983 	struct ext4_fs_context *ctx;
1984 
1985 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1986 	if (!ctx)
1987 		return -ENOMEM;
1988 
1989 	fc->fs_private = ctx;
1990 	fc->ops = &ext4_context_ops;
1991 
1992 	return 0;
1993 }
1994 
1995 #ifdef CONFIG_QUOTA
1996 /*
1997  * Note the name of the specified quota file.
1998  */
1999 static int note_qf_name(struct fs_context *fc, int qtype,
2000 		       struct fs_parameter *param)
2001 {
2002 	struct ext4_fs_context *ctx = fc->fs_private;
2003 	char *qname;
2004 
2005 	if (param->size < 1) {
2006 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2007 		return -EINVAL;
2008 	}
2009 	if (strchr(param->string, '/')) {
2010 		ext4_msg(NULL, KERN_ERR,
2011 			 "quotafile must be on filesystem root");
2012 		return -EINVAL;
2013 	}
2014 	if (ctx->s_qf_names[qtype]) {
2015 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2016 			ext4_msg(NULL, KERN_ERR,
2017 				 "%s quota file already specified",
2018 				 QTYPE2NAME(qtype));
2019 			return -EINVAL;
2020 		}
2021 		return 0;
2022 	}
2023 
2024 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2025 	if (!qname) {
2026 		ext4_msg(NULL, KERN_ERR,
2027 			 "Not enough memory for storing quotafile name");
2028 		return -ENOMEM;
2029 	}
2030 	ctx->s_qf_names[qtype] = qname;
2031 	ctx->qname_spec |= 1 << qtype;
2032 	ctx->spec |= EXT4_SPEC_JQUOTA;
2033 	return 0;
2034 }
2035 
2036 /*
2037  * Clear the name of the specified quota file.
2038  */
2039 static int unnote_qf_name(struct fs_context *fc, int qtype)
2040 {
2041 	struct ext4_fs_context *ctx = fc->fs_private;
2042 
2043 	if (ctx->s_qf_names[qtype])
2044 		kfree(ctx->s_qf_names[qtype]);
2045 
2046 	ctx->s_qf_names[qtype] = NULL;
2047 	ctx->qname_spec |= 1 << qtype;
2048 	ctx->spec |= EXT4_SPEC_JQUOTA;
2049 	return 0;
2050 }
2051 #endif
2052 
2053 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2054 					    struct ext4_fs_context *ctx)
2055 {
2056 	int err;
2057 
2058 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2059 		ext4_msg(NULL, KERN_WARNING,
2060 			 "test_dummy_encryption option not supported");
2061 		return -EINVAL;
2062 	}
2063 	err = fscrypt_parse_test_dummy_encryption(param,
2064 						  &ctx->dummy_enc_policy);
2065 	if (err == -EINVAL) {
2066 		ext4_msg(NULL, KERN_WARNING,
2067 			 "Value of option \"%s\" is unrecognized", param->key);
2068 	} else if (err == -EEXIST) {
2069 		ext4_msg(NULL, KERN_WARNING,
2070 			 "Conflicting test_dummy_encryption options");
2071 		return -EINVAL;
2072 	}
2073 	return err;
2074 }
2075 
2076 #define EXT4_SET_CTX(name)						\
2077 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2078 				  unsigned long flag)			\
2079 {									\
2080 	ctx->mask_s_##name |= flag;					\
2081 	ctx->vals_s_##name |= flag;					\
2082 }
2083 
2084 #define EXT4_CLEAR_CTX(name)						\
2085 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2086 				    unsigned long flag)			\
2087 {									\
2088 	ctx->mask_s_##name |= flag;					\
2089 	ctx->vals_s_##name &= ~flag;					\
2090 }
2091 
2092 #define EXT4_TEST_CTX(name)						\
2093 static inline unsigned long						\
2094 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2095 {									\
2096 	return (ctx->vals_s_##name & flag);				\
2097 }
2098 
2099 EXT4_SET_CTX(flags); /* set only */
2100 EXT4_SET_CTX(mount_opt);
2101 EXT4_CLEAR_CTX(mount_opt);
2102 EXT4_TEST_CTX(mount_opt);
2103 EXT4_SET_CTX(mount_opt2);
2104 EXT4_CLEAR_CTX(mount_opt2);
2105 EXT4_TEST_CTX(mount_opt2);
2106 
2107 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2108 {
2109 	set_bit(bit, &ctx->mask_s_mount_flags);
2110 	set_bit(bit, &ctx->vals_s_mount_flags);
2111 }
2112 
2113 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2114 {
2115 	struct ext4_fs_context *ctx = fc->fs_private;
2116 	struct fs_parse_result result;
2117 	const struct mount_opts *m;
2118 	int is_remount;
2119 	kuid_t uid;
2120 	kgid_t gid;
2121 	int token;
2122 
2123 	token = fs_parse(fc, ext4_param_specs, param, &result);
2124 	if (token < 0)
2125 		return token;
2126 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2127 
2128 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2129 		if (token == m->token)
2130 			break;
2131 
2132 	ctx->opt_flags |= m->flags;
2133 
2134 	if (m->flags & MOPT_EXPLICIT) {
2135 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2136 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2137 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2138 			ctx_set_mount_opt2(ctx,
2139 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2140 		} else
2141 			return -EINVAL;
2142 	}
2143 
2144 	if (m->flags & MOPT_NOSUPPORT) {
2145 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2146 			 param->key);
2147 		return 0;
2148 	}
2149 
2150 	switch (token) {
2151 #ifdef CONFIG_QUOTA
2152 	case Opt_usrjquota:
2153 		if (!*param->string)
2154 			return unnote_qf_name(fc, USRQUOTA);
2155 		else
2156 			return note_qf_name(fc, USRQUOTA, param);
2157 	case Opt_grpjquota:
2158 		if (!*param->string)
2159 			return unnote_qf_name(fc, GRPQUOTA);
2160 		else
2161 			return note_qf_name(fc, GRPQUOTA, param);
2162 #endif
2163 	case Opt_sb:
2164 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2165 			ext4_msg(NULL, KERN_WARNING,
2166 				 "Ignoring %s option on remount", param->key);
2167 		} else {
2168 			ctx->s_sb_block = result.uint_32;
2169 			ctx->spec |= EXT4_SPEC_s_sb_block;
2170 		}
2171 		return 0;
2172 	case Opt_removed:
2173 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2174 			 param->key);
2175 		return 0;
2176 	case Opt_abort:
2177 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2178 		return 0;
2179 	case Opt_inlinecrypt:
2180 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2181 		ctx_set_flags(ctx, SB_INLINECRYPT);
2182 #else
2183 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2184 #endif
2185 		return 0;
2186 	case Opt_errors:
2187 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2188 		ctx_set_mount_opt(ctx, result.uint_32);
2189 		return 0;
2190 #ifdef CONFIG_QUOTA
2191 	case Opt_jqfmt:
2192 		ctx->s_jquota_fmt = result.uint_32;
2193 		ctx->spec |= EXT4_SPEC_JQFMT;
2194 		return 0;
2195 #endif
2196 	case Opt_data:
2197 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2198 		ctx_set_mount_opt(ctx, result.uint_32);
2199 		ctx->spec |= EXT4_SPEC_DATAJ;
2200 		return 0;
2201 	case Opt_commit:
2202 		if (result.uint_32 == 0)
2203 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2204 		else if (result.uint_32 > INT_MAX / HZ) {
2205 			ext4_msg(NULL, KERN_ERR,
2206 				 "Invalid commit interval %d, "
2207 				 "must be smaller than %d",
2208 				 result.uint_32, INT_MAX / HZ);
2209 			return -EINVAL;
2210 		}
2211 		ctx->s_commit_interval = HZ * result.uint_32;
2212 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2213 		return 0;
2214 	case Opt_debug_want_extra_isize:
2215 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2216 			ext4_msg(NULL, KERN_ERR,
2217 				 "Invalid want_extra_isize %d", result.uint_32);
2218 			return -EINVAL;
2219 		}
2220 		ctx->s_want_extra_isize = result.uint_32;
2221 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2222 		return 0;
2223 	case Opt_max_batch_time:
2224 		ctx->s_max_batch_time = result.uint_32;
2225 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2226 		return 0;
2227 	case Opt_min_batch_time:
2228 		ctx->s_min_batch_time = result.uint_32;
2229 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2230 		return 0;
2231 	case Opt_inode_readahead_blks:
2232 		if (result.uint_32 &&
2233 		    (result.uint_32 > (1 << 30) ||
2234 		     !is_power_of_2(result.uint_32))) {
2235 			ext4_msg(NULL, KERN_ERR,
2236 				 "EXT4-fs: inode_readahead_blks must be "
2237 				 "0 or a power of 2 smaller than 2^31");
2238 			return -EINVAL;
2239 		}
2240 		ctx->s_inode_readahead_blks = result.uint_32;
2241 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2242 		return 0;
2243 	case Opt_init_itable:
2244 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2245 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2246 		if (param->type == fs_value_is_string)
2247 			ctx->s_li_wait_mult = result.uint_32;
2248 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2249 		return 0;
2250 	case Opt_max_dir_size_kb:
2251 		ctx->s_max_dir_size_kb = result.uint_32;
2252 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2253 		return 0;
2254 #ifdef CONFIG_EXT4_DEBUG
2255 	case Opt_fc_debug_max_replay:
2256 		ctx->s_fc_debug_max_replay = result.uint_32;
2257 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2258 		return 0;
2259 #endif
2260 	case Opt_stripe:
2261 		ctx->s_stripe = result.uint_32;
2262 		ctx->spec |= EXT4_SPEC_s_stripe;
2263 		return 0;
2264 	case Opt_resuid:
2265 		uid = make_kuid(current_user_ns(), result.uint_32);
2266 		if (!uid_valid(uid)) {
2267 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2268 				 result.uint_32);
2269 			return -EINVAL;
2270 		}
2271 		ctx->s_resuid = uid;
2272 		ctx->spec |= EXT4_SPEC_s_resuid;
2273 		return 0;
2274 	case Opt_resgid:
2275 		gid = make_kgid(current_user_ns(), result.uint_32);
2276 		if (!gid_valid(gid)) {
2277 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2278 				 result.uint_32);
2279 			return -EINVAL;
2280 		}
2281 		ctx->s_resgid = gid;
2282 		ctx->spec |= EXT4_SPEC_s_resgid;
2283 		return 0;
2284 	case Opt_journal_dev:
2285 		if (is_remount) {
2286 			ext4_msg(NULL, KERN_ERR,
2287 				 "Cannot specify journal on remount");
2288 			return -EINVAL;
2289 		}
2290 		ctx->journal_devnum = result.uint_32;
2291 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2292 		return 0;
2293 	case Opt_journal_path:
2294 	{
2295 		struct inode *journal_inode;
2296 		struct path path;
2297 		int error;
2298 
2299 		if (is_remount) {
2300 			ext4_msg(NULL, KERN_ERR,
2301 				 "Cannot specify journal on remount");
2302 			return -EINVAL;
2303 		}
2304 
2305 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2306 		if (error) {
2307 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2308 				 "journal device path");
2309 			return -EINVAL;
2310 		}
2311 
2312 		journal_inode = d_inode(path.dentry);
2313 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2314 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2315 		path_put(&path);
2316 		return 0;
2317 	}
2318 	case Opt_journal_ioprio:
2319 		if (result.uint_32 > 7) {
2320 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2321 				 " (must be 0-7)");
2322 			return -EINVAL;
2323 		}
2324 		ctx->journal_ioprio =
2325 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2326 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2327 		return 0;
2328 	case Opt_test_dummy_encryption:
2329 		return ext4_parse_test_dummy_encryption(param, ctx);
2330 	case Opt_dax:
2331 	case Opt_dax_type:
2332 #ifdef CONFIG_FS_DAX
2333 	{
2334 		int type = (token == Opt_dax) ?
2335 			   Opt_dax : result.uint_32;
2336 
2337 		switch (type) {
2338 		case Opt_dax:
2339 		case Opt_dax_always:
2340 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2341 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2342 			break;
2343 		case Opt_dax_never:
2344 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2345 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2346 			break;
2347 		case Opt_dax_inode:
2348 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2349 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2350 			/* Strictly for printing options */
2351 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2352 			break;
2353 		}
2354 		return 0;
2355 	}
2356 #else
2357 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2358 		return -EINVAL;
2359 #endif
2360 	case Opt_data_err:
2361 		if (result.uint_32 == Opt_data_err_abort)
2362 			ctx_set_mount_opt(ctx, m->mount_opt);
2363 		else if (result.uint_32 == Opt_data_err_ignore)
2364 			ctx_clear_mount_opt(ctx, m->mount_opt);
2365 		return 0;
2366 	case Opt_mb_optimize_scan:
2367 		if (result.int_32 == 1) {
2368 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2369 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2370 		} else if (result.int_32 == 0) {
2371 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2372 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2373 		} else {
2374 			ext4_msg(NULL, KERN_WARNING,
2375 				 "mb_optimize_scan should be set to 0 or 1.");
2376 			return -EINVAL;
2377 		}
2378 		return 0;
2379 	}
2380 
2381 	/*
2382 	 * At this point we should only be getting options requiring MOPT_SET,
2383 	 * or MOPT_CLEAR. Anything else is a bug
2384 	 */
2385 	if (m->token == Opt_err) {
2386 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2387 			 param->key);
2388 		WARN_ON(1);
2389 		return -EINVAL;
2390 	}
2391 
2392 	else {
2393 		unsigned int set = 0;
2394 
2395 		if ((param->type == fs_value_is_flag) ||
2396 		    result.uint_32 > 0)
2397 			set = 1;
2398 
2399 		if (m->flags & MOPT_CLEAR)
2400 			set = !set;
2401 		else if (unlikely(!(m->flags & MOPT_SET))) {
2402 			ext4_msg(NULL, KERN_WARNING,
2403 				 "buggy handling of option %s",
2404 				 param->key);
2405 			WARN_ON(1);
2406 			return -EINVAL;
2407 		}
2408 		if (m->flags & MOPT_2) {
2409 			if (set != 0)
2410 				ctx_set_mount_opt2(ctx, m->mount_opt);
2411 			else
2412 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2413 		} else {
2414 			if (set != 0)
2415 				ctx_set_mount_opt(ctx, m->mount_opt);
2416 			else
2417 				ctx_clear_mount_opt(ctx, m->mount_opt);
2418 		}
2419 	}
2420 
2421 	return 0;
2422 }
2423 
2424 static int parse_options(struct fs_context *fc, char *options)
2425 {
2426 	struct fs_parameter param;
2427 	int ret;
2428 	char *key;
2429 
2430 	if (!options)
2431 		return 0;
2432 
2433 	while ((key = strsep(&options, ",")) != NULL) {
2434 		if (*key) {
2435 			size_t v_len = 0;
2436 			char *value = strchr(key, '=');
2437 
2438 			param.type = fs_value_is_flag;
2439 			param.string = NULL;
2440 
2441 			if (value) {
2442 				if (value == key)
2443 					continue;
2444 
2445 				*value++ = 0;
2446 				v_len = strlen(value);
2447 				param.string = kmemdup_nul(value, v_len,
2448 							   GFP_KERNEL);
2449 				if (!param.string)
2450 					return -ENOMEM;
2451 				param.type = fs_value_is_string;
2452 			}
2453 
2454 			param.key = key;
2455 			param.size = v_len;
2456 
2457 			ret = ext4_parse_param(fc, &param);
2458 			if (param.string)
2459 				kfree(param.string);
2460 			if (ret < 0)
2461 				return ret;
2462 		}
2463 	}
2464 
2465 	ret = ext4_validate_options(fc);
2466 	if (ret < 0)
2467 		return ret;
2468 
2469 	return 0;
2470 }
2471 
2472 static int parse_apply_sb_mount_options(struct super_block *sb,
2473 					struct ext4_fs_context *m_ctx)
2474 {
2475 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2476 	char *s_mount_opts = NULL;
2477 	struct ext4_fs_context *s_ctx = NULL;
2478 	struct fs_context *fc = NULL;
2479 	int ret = -ENOMEM;
2480 
2481 	if (!sbi->s_es->s_mount_opts[0])
2482 		return 0;
2483 
2484 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2485 				sizeof(sbi->s_es->s_mount_opts),
2486 				GFP_KERNEL);
2487 	if (!s_mount_opts)
2488 		return ret;
2489 
2490 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2491 	if (!fc)
2492 		goto out_free;
2493 
2494 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2495 	if (!s_ctx)
2496 		goto out_free;
2497 
2498 	fc->fs_private = s_ctx;
2499 	fc->s_fs_info = sbi;
2500 
2501 	ret = parse_options(fc, s_mount_opts);
2502 	if (ret < 0)
2503 		goto parse_failed;
2504 
2505 	ret = ext4_check_opt_consistency(fc, sb);
2506 	if (ret < 0) {
2507 parse_failed:
2508 		ext4_msg(sb, KERN_WARNING,
2509 			 "failed to parse options in superblock: %s",
2510 			 s_mount_opts);
2511 		ret = 0;
2512 		goto out_free;
2513 	}
2514 
2515 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2516 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2517 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2518 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2519 
2520 	ext4_apply_options(fc, sb);
2521 	ret = 0;
2522 
2523 out_free:
2524 	if (fc) {
2525 		ext4_fc_free(fc);
2526 		kfree(fc);
2527 	}
2528 	kfree(s_mount_opts);
2529 	return ret;
2530 }
2531 
2532 static void ext4_apply_quota_options(struct fs_context *fc,
2533 				     struct super_block *sb)
2534 {
2535 #ifdef CONFIG_QUOTA
2536 	bool quota_feature = ext4_has_feature_quota(sb);
2537 	struct ext4_fs_context *ctx = fc->fs_private;
2538 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2539 	char *qname;
2540 	int i;
2541 
2542 	if (quota_feature)
2543 		return;
2544 
2545 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2546 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2547 			if (!(ctx->qname_spec & (1 << i)))
2548 				continue;
2549 
2550 			qname = ctx->s_qf_names[i]; /* May be NULL */
2551 			if (qname)
2552 				set_opt(sb, QUOTA);
2553 			ctx->s_qf_names[i] = NULL;
2554 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2555 						lockdep_is_held(&sb->s_umount));
2556 			if (qname)
2557 				kfree_rcu_mightsleep(qname);
2558 		}
2559 	}
2560 
2561 	if (ctx->spec & EXT4_SPEC_JQFMT)
2562 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2563 #endif
2564 }
2565 
2566 /*
2567  * Check quota settings consistency.
2568  */
2569 static int ext4_check_quota_consistency(struct fs_context *fc,
2570 					struct super_block *sb)
2571 {
2572 #ifdef CONFIG_QUOTA
2573 	struct ext4_fs_context *ctx = fc->fs_private;
2574 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2575 	bool quota_feature = ext4_has_feature_quota(sb);
2576 	bool quota_loaded = sb_any_quota_loaded(sb);
2577 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2578 	int quota_flags, i;
2579 
2580 	/*
2581 	 * We do the test below only for project quotas. 'usrquota' and
2582 	 * 'grpquota' mount options are allowed even without quota feature
2583 	 * to support legacy quotas in quota files.
2584 	 */
2585 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2586 	    !ext4_has_feature_project(sb)) {
2587 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2588 			 "Cannot enable project quota enforcement.");
2589 		return -EINVAL;
2590 	}
2591 
2592 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2593 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2594 	if (quota_loaded &&
2595 	    ctx->mask_s_mount_opt & quota_flags &&
2596 	    !ctx_test_mount_opt(ctx, quota_flags))
2597 		goto err_quota_change;
2598 
2599 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2600 
2601 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2602 			if (!(ctx->qname_spec & (1 << i)))
2603 				continue;
2604 
2605 			if (quota_loaded &&
2606 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2607 				goto err_jquota_change;
2608 
2609 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2610 			    strcmp(get_qf_name(sb, sbi, i),
2611 				   ctx->s_qf_names[i]) != 0)
2612 				goto err_jquota_specified;
2613 		}
2614 
2615 		if (quota_feature) {
2616 			ext4_msg(NULL, KERN_INFO,
2617 				 "Journaled quota options ignored when "
2618 				 "QUOTA feature is enabled");
2619 			return 0;
2620 		}
2621 	}
2622 
2623 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2624 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2625 			goto err_jquota_change;
2626 		if (quota_feature) {
2627 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2628 				 "ignored when QUOTA feature is enabled");
2629 			return 0;
2630 		}
2631 	}
2632 
2633 	/* Make sure we don't mix old and new quota format */
2634 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2635 		       ctx->s_qf_names[USRQUOTA]);
2636 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2637 		       ctx->s_qf_names[GRPQUOTA]);
2638 
2639 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2640 		    test_opt(sb, USRQUOTA));
2641 
2642 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2643 		    test_opt(sb, GRPQUOTA));
2644 
2645 	if (usr_qf_name) {
2646 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2647 		usrquota = false;
2648 	}
2649 	if (grp_qf_name) {
2650 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2651 		grpquota = false;
2652 	}
2653 
2654 	if (usr_qf_name || grp_qf_name) {
2655 		if (usrquota || grpquota) {
2656 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2657 				 "format mixing");
2658 			return -EINVAL;
2659 		}
2660 
2661 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2662 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2663 				 "not specified");
2664 			return -EINVAL;
2665 		}
2666 	}
2667 
2668 	return 0;
2669 
2670 err_quota_change:
2671 	ext4_msg(NULL, KERN_ERR,
2672 		 "Cannot change quota options when quota turned on");
2673 	return -EINVAL;
2674 err_jquota_change:
2675 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2676 		 "options when quota turned on");
2677 	return -EINVAL;
2678 err_jquota_specified:
2679 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2680 		 QTYPE2NAME(i));
2681 	return -EINVAL;
2682 #else
2683 	return 0;
2684 #endif
2685 }
2686 
2687 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2688 					    struct super_block *sb)
2689 {
2690 	const struct ext4_fs_context *ctx = fc->fs_private;
2691 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2692 
2693 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2694 		return 0;
2695 
2696 	if (!ext4_has_feature_encrypt(sb)) {
2697 		ext4_msg(NULL, KERN_WARNING,
2698 			 "test_dummy_encryption requires encrypt feature");
2699 		return -EINVAL;
2700 	}
2701 	/*
2702 	 * This mount option is just for testing, and it's not worthwhile to
2703 	 * implement the extra complexity (e.g. RCU protection) that would be
2704 	 * needed to allow it to be set or changed during remount.  We do allow
2705 	 * it to be specified during remount, but only if there is no change.
2706 	 */
2707 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2708 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2709 						 &ctx->dummy_enc_policy))
2710 			return 0;
2711 		ext4_msg(NULL, KERN_WARNING,
2712 			 "Can't set or change test_dummy_encryption on remount");
2713 		return -EINVAL;
2714 	}
2715 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2716 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2717 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2718 						 &ctx->dummy_enc_policy))
2719 			return 0;
2720 		ext4_msg(NULL, KERN_WARNING,
2721 			 "Conflicting test_dummy_encryption options");
2722 		return -EINVAL;
2723 	}
2724 	return 0;
2725 }
2726 
2727 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2728 					     struct super_block *sb)
2729 {
2730 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2731 	    /* if already set, it was already verified to be the same */
2732 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2733 		return;
2734 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2735 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2736 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2737 }
2738 
2739 static int ext4_check_opt_consistency(struct fs_context *fc,
2740 				      struct super_block *sb)
2741 {
2742 	struct ext4_fs_context *ctx = fc->fs_private;
2743 	struct ext4_sb_info *sbi = fc->s_fs_info;
2744 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2745 	int err;
2746 
2747 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2748 		ext4_msg(NULL, KERN_ERR,
2749 			 "Mount option(s) incompatible with ext2");
2750 		return -EINVAL;
2751 	}
2752 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2753 		ext4_msg(NULL, KERN_ERR,
2754 			 "Mount option(s) incompatible with ext3");
2755 		return -EINVAL;
2756 	}
2757 
2758 	if (ctx->s_want_extra_isize >
2759 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2760 		ext4_msg(NULL, KERN_ERR,
2761 			 "Invalid want_extra_isize %d",
2762 			 ctx->s_want_extra_isize);
2763 		return -EINVAL;
2764 	}
2765 
2766 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2767 		int blocksize =
2768 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2769 		if (blocksize < PAGE_SIZE)
2770 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2771 				 "experimental mount option 'dioread_nolock' "
2772 				 "for blocksize < PAGE_SIZE");
2773 	}
2774 
2775 	err = ext4_check_test_dummy_encryption(fc, sb);
2776 	if (err)
2777 		return err;
2778 
2779 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2780 		if (!sbi->s_journal) {
2781 			ext4_msg(NULL, KERN_WARNING,
2782 				 "Remounting file system with no journal "
2783 				 "so ignoring journalled data option");
2784 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2785 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2786 			   test_opt(sb, DATA_FLAGS)) {
2787 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2788 				 "on remount");
2789 			return -EINVAL;
2790 		}
2791 	}
2792 
2793 	if (is_remount) {
2794 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2795 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2796 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2797 				 "both data=journal and dax");
2798 			return -EINVAL;
2799 		}
2800 
2801 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2802 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2803 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2804 fail_dax_change_remount:
2805 			ext4_msg(NULL, KERN_ERR, "can't change "
2806 				 "dax mount option while remounting");
2807 			return -EINVAL;
2808 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2809 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2810 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2811 			goto fail_dax_change_remount;
2812 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2813 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2814 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2815 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2816 			goto fail_dax_change_remount;
2817 		}
2818 	}
2819 
2820 	return ext4_check_quota_consistency(fc, sb);
2821 }
2822 
2823 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2824 {
2825 	struct ext4_fs_context *ctx = fc->fs_private;
2826 	struct ext4_sb_info *sbi = fc->s_fs_info;
2827 
2828 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2829 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2830 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2831 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2832 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2833 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2834 	sb->s_flags &= ~ctx->mask_s_flags;
2835 	sb->s_flags |= ctx->vals_s_flags;
2836 
2837 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2838 	APPLY(s_commit_interval);
2839 	APPLY(s_stripe);
2840 	APPLY(s_max_batch_time);
2841 	APPLY(s_min_batch_time);
2842 	APPLY(s_want_extra_isize);
2843 	APPLY(s_inode_readahead_blks);
2844 	APPLY(s_max_dir_size_kb);
2845 	APPLY(s_li_wait_mult);
2846 	APPLY(s_resgid);
2847 	APPLY(s_resuid);
2848 
2849 #ifdef CONFIG_EXT4_DEBUG
2850 	APPLY(s_fc_debug_max_replay);
2851 #endif
2852 
2853 	ext4_apply_quota_options(fc, sb);
2854 	ext4_apply_test_dummy_encryption(ctx, sb);
2855 }
2856 
2857 
2858 static int ext4_validate_options(struct fs_context *fc)
2859 {
2860 #ifdef CONFIG_QUOTA
2861 	struct ext4_fs_context *ctx = fc->fs_private;
2862 	char *usr_qf_name, *grp_qf_name;
2863 
2864 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2865 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2866 
2867 	if (usr_qf_name || grp_qf_name) {
2868 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2869 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2870 
2871 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2872 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2873 
2874 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2875 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2876 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2877 				 "format mixing");
2878 			return -EINVAL;
2879 		}
2880 	}
2881 #endif
2882 	return 1;
2883 }
2884 
2885 static inline void ext4_show_quota_options(struct seq_file *seq,
2886 					   struct super_block *sb)
2887 {
2888 #if defined(CONFIG_QUOTA)
2889 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2890 	char *usr_qf_name, *grp_qf_name;
2891 
2892 	if (sbi->s_jquota_fmt) {
2893 		char *fmtname = "";
2894 
2895 		switch (sbi->s_jquota_fmt) {
2896 		case QFMT_VFS_OLD:
2897 			fmtname = "vfsold";
2898 			break;
2899 		case QFMT_VFS_V0:
2900 			fmtname = "vfsv0";
2901 			break;
2902 		case QFMT_VFS_V1:
2903 			fmtname = "vfsv1";
2904 			break;
2905 		}
2906 		seq_printf(seq, ",jqfmt=%s", fmtname);
2907 	}
2908 
2909 	rcu_read_lock();
2910 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2911 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2912 	if (usr_qf_name)
2913 		seq_show_option(seq, "usrjquota", usr_qf_name);
2914 	if (grp_qf_name)
2915 		seq_show_option(seq, "grpjquota", grp_qf_name);
2916 	rcu_read_unlock();
2917 #endif
2918 }
2919 
2920 static const char *token2str(int token)
2921 {
2922 	const struct fs_parameter_spec *spec;
2923 
2924 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2925 		if (spec->opt == token && !spec->type)
2926 			break;
2927 	return spec->name;
2928 }
2929 
2930 /*
2931  * Show an option if
2932  *  - it's set to a non-default value OR
2933  *  - if the per-sb default is different from the global default
2934  */
2935 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2936 			      int nodefs)
2937 {
2938 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2939 	struct ext4_super_block *es = sbi->s_es;
2940 	int def_errors;
2941 	const struct mount_opts *m;
2942 	char sep = nodefs ? '\n' : ',';
2943 
2944 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2945 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2946 
2947 	if (sbi->s_sb_block != 1)
2948 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2949 
2950 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2951 		int want_set = m->flags & MOPT_SET;
2952 		int opt_2 = m->flags & MOPT_2;
2953 		unsigned int mount_opt, def_mount_opt;
2954 
2955 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2956 		    m->flags & MOPT_SKIP)
2957 			continue;
2958 
2959 		if (opt_2) {
2960 			mount_opt = sbi->s_mount_opt2;
2961 			def_mount_opt = sbi->s_def_mount_opt2;
2962 		} else {
2963 			mount_opt = sbi->s_mount_opt;
2964 			def_mount_opt = sbi->s_def_mount_opt;
2965 		}
2966 		/* skip if same as the default */
2967 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2968 			continue;
2969 		/* select Opt_noFoo vs Opt_Foo */
2970 		if ((want_set &&
2971 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2972 		    (!want_set && (mount_opt & m->mount_opt)))
2973 			continue;
2974 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2975 	}
2976 
2977 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2978 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2979 		SEQ_OPTS_PRINT("resuid=%u",
2980 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2981 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2982 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2983 		SEQ_OPTS_PRINT("resgid=%u",
2984 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2985 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2986 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2987 		SEQ_OPTS_PUTS("errors=remount-ro");
2988 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2989 		SEQ_OPTS_PUTS("errors=continue");
2990 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2991 		SEQ_OPTS_PUTS("errors=panic");
2992 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2993 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2994 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2995 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2996 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2997 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2998 	if (nodefs || sbi->s_stripe)
2999 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3000 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3001 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3002 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3003 			SEQ_OPTS_PUTS("data=journal");
3004 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3005 			SEQ_OPTS_PUTS("data=ordered");
3006 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3007 			SEQ_OPTS_PUTS("data=writeback");
3008 	}
3009 	if (nodefs ||
3010 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3011 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3012 			       sbi->s_inode_readahead_blks);
3013 
3014 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3015 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3016 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3017 	if (nodefs || sbi->s_max_dir_size_kb)
3018 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3019 	if (test_opt(sb, DATA_ERR_ABORT))
3020 		SEQ_OPTS_PUTS("data_err=abort");
3021 
3022 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3023 
3024 	if (sb->s_flags & SB_INLINECRYPT)
3025 		SEQ_OPTS_PUTS("inlinecrypt");
3026 
3027 	if (test_opt(sb, DAX_ALWAYS)) {
3028 		if (IS_EXT2_SB(sb))
3029 			SEQ_OPTS_PUTS("dax");
3030 		else
3031 			SEQ_OPTS_PUTS("dax=always");
3032 	} else if (test_opt2(sb, DAX_NEVER)) {
3033 		SEQ_OPTS_PUTS("dax=never");
3034 	} else if (test_opt2(sb, DAX_INODE)) {
3035 		SEQ_OPTS_PUTS("dax=inode");
3036 	}
3037 
3038 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3039 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3040 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3041 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3042 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3043 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3044 	}
3045 
3046 	ext4_show_quota_options(seq, sb);
3047 	return 0;
3048 }
3049 
3050 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3051 {
3052 	return _ext4_show_options(seq, root->d_sb, 0);
3053 }
3054 
3055 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3056 {
3057 	struct super_block *sb = seq->private;
3058 	int rc;
3059 
3060 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3061 	rc = _ext4_show_options(seq, sb, 1);
3062 	seq_puts(seq, "\n");
3063 	return rc;
3064 }
3065 
3066 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3067 			    int read_only)
3068 {
3069 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3070 	int err = 0;
3071 
3072 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3073 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3074 			 "forcing read-only mode");
3075 		err = -EROFS;
3076 		goto done;
3077 	}
3078 	if (read_only)
3079 		goto done;
3080 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3081 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3082 			 "running e2fsck is recommended");
3083 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3084 		ext4_msg(sb, KERN_WARNING,
3085 			 "warning: mounting fs with errors, "
3086 			 "running e2fsck is recommended");
3087 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3088 		 le16_to_cpu(es->s_mnt_count) >=
3089 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3090 		ext4_msg(sb, KERN_WARNING,
3091 			 "warning: maximal mount count reached, "
3092 			 "running e2fsck is recommended");
3093 	else if (le32_to_cpu(es->s_checkinterval) &&
3094 		 (ext4_get_tstamp(es, s_lastcheck) +
3095 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3096 		ext4_msg(sb, KERN_WARNING,
3097 			 "warning: checktime reached, "
3098 			 "running e2fsck is recommended");
3099 	if (!sbi->s_journal)
3100 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3101 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3102 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3103 	le16_add_cpu(&es->s_mnt_count, 1);
3104 	ext4_update_tstamp(es, s_mtime);
3105 	if (sbi->s_journal) {
3106 		ext4_set_feature_journal_needs_recovery(sb);
3107 		if (ext4_has_feature_orphan_file(sb))
3108 			ext4_set_feature_orphan_present(sb);
3109 	}
3110 
3111 	err = ext4_commit_super(sb);
3112 done:
3113 	if (test_opt(sb, DEBUG))
3114 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3115 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3116 			sb->s_blocksize,
3117 			sbi->s_groups_count,
3118 			EXT4_BLOCKS_PER_GROUP(sb),
3119 			EXT4_INODES_PER_GROUP(sb),
3120 			sbi->s_mount_opt, sbi->s_mount_opt2);
3121 	return err;
3122 }
3123 
3124 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3125 {
3126 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3127 	struct flex_groups **old_groups, **new_groups;
3128 	int size, i, j;
3129 
3130 	if (!sbi->s_log_groups_per_flex)
3131 		return 0;
3132 
3133 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3134 	if (size <= sbi->s_flex_groups_allocated)
3135 		return 0;
3136 
3137 	new_groups = kvzalloc(roundup_pow_of_two(size *
3138 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3139 	if (!new_groups) {
3140 		ext4_msg(sb, KERN_ERR,
3141 			 "not enough memory for %d flex group pointers", size);
3142 		return -ENOMEM;
3143 	}
3144 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3145 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3146 					 sizeof(struct flex_groups)),
3147 					 GFP_KERNEL);
3148 		if (!new_groups[i]) {
3149 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3150 				kvfree(new_groups[j]);
3151 			kvfree(new_groups);
3152 			ext4_msg(sb, KERN_ERR,
3153 				 "not enough memory for %d flex groups", size);
3154 			return -ENOMEM;
3155 		}
3156 	}
3157 	rcu_read_lock();
3158 	old_groups = rcu_dereference(sbi->s_flex_groups);
3159 	if (old_groups)
3160 		memcpy(new_groups, old_groups,
3161 		       (sbi->s_flex_groups_allocated *
3162 			sizeof(struct flex_groups *)));
3163 	rcu_read_unlock();
3164 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3165 	sbi->s_flex_groups_allocated = size;
3166 	if (old_groups)
3167 		ext4_kvfree_array_rcu(old_groups);
3168 	return 0;
3169 }
3170 
3171 static int ext4_fill_flex_info(struct super_block *sb)
3172 {
3173 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3174 	struct ext4_group_desc *gdp = NULL;
3175 	struct flex_groups *fg;
3176 	ext4_group_t flex_group;
3177 	int i, err;
3178 
3179 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3180 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3181 		sbi->s_log_groups_per_flex = 0;
3182 		return 1;
3183 	}
3184 
3185 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3186 	if (err)
3187 		goto failed;
3188 
3189 	for (i = 0; i < sbi->s_groups_count; i++) {
3190 		gdp = ext4_get_group_desc(sb, i, NULL);
3191 
3192 		flex_group = ext4_flex_group(sbi, i);
3193 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3194 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3195 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3196 			     &fg->free_clusters);
3197 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3198 	}
3199 
3200 	return 1;
3201 failed:
3202 	return 0;
3203 }
3204 
3205 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3206 				   struct ext4_group_desc *gdp)
3207 {
3208 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3209 	__u16 crc = 0;
3210 	__le32 le_group = cpu_to_le32(block_group);
3211 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3212 
3213 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3214 		/* Use new metadata_csum algorithm */
3215 		__u32 csum32;
3216 		__u16 dummy_csum = 0;
3217 
3218 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3219 				     sizeof(le_group));
3220 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3221 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3222 				     sizeof(dummy_csum));
3223 		offset += sizeof(dummy_csum);
3224 		if (offset < sbi->s_desc_size)
3225 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3226 					     sbi->s_desc_size - offset);
3227 
3228 		crc = csum32 & 0xFFFF;
3229 		goto out;
3230 	}
3231 
3232 	/* old crc16 code */
3233 	if (!ext4_has_feature_gdt_csum(sb))
3234 		return 0;
3235 
3236 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3237 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3238 	crc = crc16(crc, (__u8 *)gdp, offset);
3239 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3240 	/* for checksum of struct ext4_group_desc do the rest...*/
3241 	if (ext4_has_feature_64bit(sb) &&
3242 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3243 		crc = crc16(crc, (__u8 *)gdp + offset,
3244 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3245 				offset);
3246 
3247 out:
3248 	return cpu_to_le16(crc);
3249 }
3250 
3251 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3252 				struct ext4_group_desc *gdp)
3253 {
3254 	if (ext4_has_group_desc_csum(sb) &&
3255 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3256 		return 0;
3257 
3258 	return 1;
3259 }
3260 
3261 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3262 			      struct ext4_group_desc *gdp)
3263 {
3264 	if (!ext4_has_group_desc_csum(sb))
3265 		return;
3266 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3267 }
3268 
3269 /* Called at mount-time, super-block is locked */
3270 static int ext4_check_descriptors(struct super_block *sb,
3271 				  ext4_fsblk_t sb_block,
3272 				  ext4_group_t *first_not_zeroed)
3273 {
3274 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3275 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3276 	ext4_fsblk_t last_block;
3277 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3278 	ext4_fsblk_t block_bitmap;
3279 	ext4_fsblk_t inode_bitmap;
3280 	ext4_fsblk_t inode_table;
3281 	int flexbg_flag = 0;
3282 	ext4_group_t i, grp = sbi->s_groups_count;
3283 
3284 	if (ext4_has_feature_flex_bg(sb))
3285 		flexbg_flag = 1;
3286 
3287 	ext4_debug("Checking group descriptors");
3288 
3289 	for (i = 0; i < sbi->s_groups_count; i++) {
3290 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3291 
3292 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3293 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3294 		else
3295 			last_block = first_block +
3296 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3297 
3298 		if ((grp == sbi->s_groups_count) &&
3299 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3300 			grp = i;
3301 
3302 		block_bitmap = ext4_block_bitmap(sb, gdp);
3303 		if (block_bitmap == sb_block) {
3304 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3305 				 "Block bitmap for group %u overlaps "
3306 				 "superblock", i);
3307 			if (!sb_rdonly(sb))
3308 				return 0;
3309 		}
3310 		if (block_bitmap >= sb_block + 1 &&
3311 		    block_bitmap <= last_bg_block) {
3312 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3313 				 "Block bitmap for group %u overlaps "
3314 				 "block group descriptors", i);
3315 			if (!sb_rdonly(sb))
3316 				return 0;
3317 		}
3318 		if (block_bitmap < first_block || block_bitmap > last_block) {
3319 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3320 			       "Block bitmap for group %u not in group "
3321 			       "(block %llu)!", i, block_bitmap);
3322 			return 0;
3323 		}
3324 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3325 		if (inode_bitmap == sb_block) {
3326 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3327 				 "Inode bitmap for group %u overlaps "
3328 				 "superblock", i);
3329 			if (!sb_rdonly(sb))
3330 				return 0;
3331 		}
3332 		if (inode_bitmap >= sb_block + 1 &&
3333 		    inode_bitmap <= last_bg_block) {
3334 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3335 				 "Inode bitmap for group %u overlaps "
3336 				 "block group descriptors", i);
3337 			if (!sb_rdonly(sb))
3338 				return 0;
3339 		}
3340 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3341 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3342 			       "Inode bitmap for group %u not in group "
3343 			       "(block %llu)!", i, inode_bitmap);
3344 			return 0;
3345 		}
3346 		inode_table = ext4_inode_table(sb, gdp);
3347 		if (inode_table == sb_block) {
3348 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3349 				 "Inode table for group %u overlaps "
3350 				 "superblock", i);
3351 			if (!sb_rdonly(sb))
3352 				return 0;
3353 		}
3354 		if (inode_table >= sb_block + 1 &&
3355 		    inode_table <= last_bg_block) {
3356 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3357 				 "Inode table for group %u overlaps "
3358 				 "block group descriptors", i);
3359 			if (!sb_rdonly(sb))
3360 				return 0;
3361 		}
3362 		if (inode_table < first_block ||
3363 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3364 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3365 			       "Inode table for group %u not in group "
3366 			       "(block %llu)!", i, inode_table);
3367 			return 0;
3368 		}
3369 		ext4_lock_group(sb, i);
3370 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3371 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3372 				 "Checksum for group %u failed (%u!=%u)",
3373 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3374 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3375 			if (!sb_rdonly(sb)) {
3376 				ext4_unlock_group(sb, i);
3377 				return 0;
3378 			}
3379 		}
3380 		ext4_unlock_group(sb, i);
3381 		if (!flexbg_flag)
3382 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3383 	}
3384 	if (NULL != first_not_zeroed)
3385 		*first_not_zeroed = grp;
3386 	return 1;
3387 }
3388 
3389 /*
3390  * Maximal extent format file size.
3391  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3392  * extent format containers, within a sector_t, and within i_blocks
3393  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3394  * so that won't be a limiting factor.
3395  *
3396  * However there is other limiting factor. We do store extents in the form
3397  * of starting block and length, hence the resulting length of the extent
3398  * covering maximum file size must fit into on-disk format containers as
3399  * well. Given that length is always by 1 unit bigger than max unit (because
3400  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3401  *
3402  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3403  */
3404 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3405 {
3406 	loff_t res;
3407 	loff_t upper_limit = MAX_LFS_FILESIZE;
3408 
3409 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3410 
3411 	if (!has_huge_files) {
3412 		upper_limit = (1LL << 32) - 1;
3413 
3414 		/* total blocks in file system block size */
3415 		upper_limit >>= (blkbits - 9);
3416 		upper_limit <<= blkbits;
3417 	}
3418 
3419 	/*
3420 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3421 	 * by one fs block, so ee_len can cover the extent of maximum file
3422 	 * size
3423 	 */
3424 	res = (1LL << 32) - 1;
3425 	res <<= blkbits;
3426 
3427 	/* Sanity check against vm- & vfs- imposed limits */
3428 	if (res > upper_limit)
3429 		res = upper_limit;
3430 
3431 	return res;
3432 }
3433 
3434 /*
3435  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3436  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3437  * We need to be 1 filesystem block less than the 2^48 sector limit.
3438  */
3439 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3440 {
3441 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3442 	int meta_blocks;
3443 	unsigned int ppb = 1 << (bits - 2);
3444 
3445 	/*
3446 	 * This is calculated to be the largest file size for a dense, block
3447 	 * mapped file such that the file's total number of 512-byte sectors,
3448 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3449 	 *
3450 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3451 	 * number of 512-byte sectors of the file.
3452 	 */
3453 	if (!has_huge_files) {
3454 		/*
3455 		 * !has_huge_files or implies that the inode i_block field
3456 		 * represents total file blocks in 2^32 512-byte sectors ==
3457 		 * size of vfs inode i_blocks * 8
3458 		 */
3459 		upper_limit = (1LL << 32) - 1;
3460 
3461 		/* total blocks in file system block size */
3462 		upper_limit >>= (bits - 9);
3463 
3464 	} else {
3465 		/*
3466 		 * We use 48 bit ext4_inode i_blocks
3467 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3468 		 * represent total number of blocks in
3469 		 * file system block size
3470 		 */
3471 		upper_limit = (1LL << 48) - 1;
3472 
3473 	}
3474 
3475 	/* Compute how many blocks we can address by block tree */
3476 	res += ppb;
3477 	res += ppb * ppb;
3478 	res += ((loff_t)ppb) * ppb * ppb;
3479 	/* Compute how many metadata blocks are needed */
3480 	meta_blocks = 1;
3481 	meta_blocks += 1 + ppb;
3482 	meta_blocks += 1 + ppb + ppb * ppb;
3483 	/* Does block tree limit file size? */
3484 	if (res + meta_blocks <= upper_limit)
3485 		goto check_lfs;
3486 
3487 	res = upper_limit;
3488 	/* How many metadata blocks are needed for addressing upper_limit? */
3489 	upper_limit -= EXT4_NDIR_BLOCKS;
3490 	/* indirect blocks */
3491 	meta_blocks = 1;
3492 	upper_limit -= ppb;
3493 	/* double indirect blocks */
3494 	if (upper_limit < ppb * ppb) {
3495 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3496 		res -= meta_blocks;
3497 		goto check_lfs;
3498 	}
3499 	meta_blocks += 1 + ppb;
3500 	upper_limit -= ppb * ppb;
3501 	/* tripple indirect blocks for the rest */
3502 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3503 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3504 	res -= meta_blocks;
3505 check_lfs:
3506 	res <<= bits;
3507 	if (res > MAX_LFS_FILESIZE)
3508 		res = MAX_LFS_FILESIZE;
3509 
3510 	return res;
3511 }
3512 
3513 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3514 				   ext4_fsblk_t logical_sb_block, int nr)
3515 {
3516 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3517 	ext4_group_t bg, first_meta_bg;
3518 	int has_super = 0;
3519 
3520 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3521 
3522 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3523 		return logical_sb_block + nr + 1;
3524 	bg = sbi->s_desc_per_block * nr;
3525 	if (ext4_bg_has_super(sb, bg))
3526 		has_super = 1;
3527 
3528 	/*
3529 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3530 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3531 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3532 	 * compensate.
3533 	 */
3534 	if (sb->s_blocksize == 1024 && nr == 0 &&
3535 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3536 		has_super++;
3537 
3538 	return (has_super + ext4_group_first_block_no(sb, bg));
3539 }
3540 
3541 /**
3542  * ext4_get_stripe_size: Get the stripe size.
3543  * @sbi: In memory super block info
3544  *
3545  * If we have specified it via mount option, then
3546  * use the mount option value. If the value specified at mount time is
3547  * greater than the blocks per group use the super block value.
3548  * If the super block value is greater than blocks per group return 0.
3549  * Allocator needs it be less than blocks per group.
3550  *
3551  */
3552 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3553 {
3554 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3555 	unsigned long stripe_width =
3556 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3557 	int ret;
3558 
3559 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3560 		ret = sbi->s_stripe;
3561 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3562 		ret = stripe_width;
3563 	else if (stride && stride <= sbi->s_blocks_per_group)
3564 		ret = stride;
3565 	else
3566 		ret = 0;
3567 
3568 	/*
3569 	 * If the stripe width is 1, this makes no sense and
3570 	 * we set it to 0 to turn off stripe handling code.
3571 	 */
3572 	if (ret <= 1)
3573 		ret = 0;
3574 
3575 	return ret;
3576 }
3577 
3578 /*
3579  * Check whether this filesystem can be mounted based on
3580  * the features present and the RDONLY/RDWR mount requested.
3581  * Returns 1 if this filesystem can be mounted as requested,
3582  * 0 if it cannot be.
3583  */
3584 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3585 {
3586 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3587 		ext4_msg(sb, KERN_ERR,
3588 			"Couldn't mount because of "
3589 			"unsupported optional features (%x)",
3590 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3591 			~EXT4_FEATURE_INCOMPAT_SUPP));
3592 		return 0;
3593 	}
3594 
3595 #if !IS_ENABLED(CONFIG_UNICODE)
3596 	if (ext4_has_feature_casefold(sb)) {
3597 		ext4_msg(sb, KERN_ERR,
3598 			 "Filesystem with casefold feature cannot be "
3599 			 "mounted without CONFIG_UNICODE");
3600 		return 0;
3601 	}
3602 #endif
3603 
3604 	if (readonly)
3605 		return 1;
3606 
3607 	if (ext4_has_feature_readonly(sb)) {
3608 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3609 		sb->s_flags |= SB_RDONLY;
3610 		return 1;
3611 	}
3612 
3613 	/* Check that feature set is OK for a read-write mount */
3614 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3615 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3616 			 "unsupported optional features (%x)",
3617 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3618 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3619 		return 0;
3620 	}
3621 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3622 		ext4_msg(sb, KERN_ERR,
3623 			 "Can't support bigalloc feature without "
3624 			 "extents feature\n");
3625 		return 0;
3626 	}
3627 
3628 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3629 	if (!readonly && (ext4_has_feature_quota(sb) ||
3630 			  ext4_has_feature_project(sb))) {
3631 		ext4_msg(sb, KERN_ERR,
3632 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3633 		return 0;
3634 	}
3635 #endif  /* CONFIG_QUOTA */
3636 	return 1;
3637 }
3638 
3639 /*
3640  * This function is called once a day if we have errors logged
3641  * on the file system
3642  */
3643 static void print_daily_error_info(struct timer_list *t)
3644 {
3645 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3646 	struct super_block *sb = sbi->s_sb;
3647 	struct ext4_super_block *es = sbi->s_es;
3648 
3649 	if (es->s_error_count)
3650 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3651 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3652 			 le32_to_cpu(es->s_error_count));
3653 	if (es->s_first_error_time) {
3654 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3655 		       sb->s_id,
3656 		       ext4_get_tstamp(es, s_first_error_time),
3657 		       (int) sizeof(es->s_first_error_func),
3658 		       es->s_first_error_func,
3659 		       le32_to_cpu(es->s_first_error_line));
3660 		if (es->s_first_error_ino)
3661 			printk(KERN_CONT ": inode %u",
3662 			       le32_to_cpu(es->s_first_error_ino));
3663 		if (es->s_first_error_block)
3664 			printk(KERN_CONT ": block %llu", (unsigned long long)
3665 			       le64_to_cpu(es->s_first_error_block));
3666 		printk(KERN_CONT "\n");
3667 	}
3668 	if (es->s_last_error_time) {
3669 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3670 		       sb->s_id,
3671 		       ext4_get_tstamp(es, s_last_error_time),
3672 		       (int) sizeof(es->s_last_error_func),
3673 		       es->s_last_error_func,
3674 		       le32_to_cpu(es->s_last_error_line));
3675 		if (es->s_last_error_ino)
3676 			printk(KERN_CONT ": inode %u",
3677 			       le32_to_cpu(es->s_last_error_ino));
3678 		if (es->s_last_error_block)
3679 			printk(KERN_CONT ": block %llu", (unsigned long long)
3680 			       le64_to_cpu(es->s_last_error_block));
3681 		printk(KERN_CONT "\n");
3682 	}
3683 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3684 }
3685 
3686 /* Find next suitable group and run ext4_init_inode_table */
3687 static int ext4_run_li_request(struct ext4_li_request *elr)
3688 {
3689 	struct ext4_group_desc *gdp = NULL;
3690 	struct super_block *sb = elr->lr_super;
3691 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3692 	ext4_group_t group = elr->lr_next_group;
3693 	unsigned int prefetch_ios = 0;
3694 	int ret = 0;
3695 	u64 start_time;
3696 
3697 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3698 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3699 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3700 		if (prefetch_ios)
3701 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3702 					      prefetch_ios);
3703 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3704 					    prefetch_ios);
3705 		if (group >= elr->lr_next_group) {
3706 			ret = 1;
3707 			if (elr->lr_first_not_zeroed != ngroups &&
3708 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3709 				elr->lr_next_group = elr->lr_first_not_zeroed;
3710 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3711 				ret = 0;
3712 			}
3713 		}
3714 		return ret;
3715 	}
3716 
3717 	for (; group < ngroups; group++) {
3718 		gdp = ext4_get_group_desc(sb, group, NULL);
3719 		if (!gdp) {
3720 			ret = 1;
3721 			break;
3722 		}
3723 
3724 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3725 			break;
3726 	}
3727 
3728 	if (group >= ngroups)
3729 		ret = 1;
3730 
3731 	if (!ret) {
3732 		start_time = ktime_get_real_ns();
3733 		ret = ext4_init_inode_table(sb, group,
3734 					    elr->lr_timeout ? 0 : 1);
3735 		trace_ext4_lazy_itable_init(sb, group);
3736 		if (elr->lr_timeout == 0) {
3737 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3738 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3739 		}
3740 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3741 		elr->lr_next_group = group + 1;
3742 	}
3743 	return ret;
3744 }
3745 
3746 /*
3747  * Remove lr_request from the list_request and free the
3748  * request structure. Should be called with li_list_mtx held
3749  */
3750 static void ext4_remove_li_request(struct ext4_li_request *elr)
3751 {
3752 	if (!elr)
3753 		return;
3754 
3755 	list_del(&elr->lr_request);
3756 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3757 	kfree(elr);
3758 }
3759 
3760 static void ext4_unregister_li_request(struct super_block *sb)
3761 {
3762 	mutex_lock(&ext4_li_mtx);
3763 	if (!ext4_li_info) {
3764 		mutex_unlock(&ext4_li_mtx);
3765 		return;
3766 	}
3767 
3768 	mutex_lock(&ext4_li_info->li_list_mtx);
3769 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3770 	mutex_unlock(&ext4_li_info->li_list_mtx);
3771 	mutex_unlock(&ext4_li_mtx);
3772 }
3773 
3774 static struct task_struct *ext4_lazyinit_task;
3775 
3776 /*
3777  * This is the function where ext4lazyinit thread lives. It walks
3778  * through the request list searching for next scheduled filesystem.
3779  * When such a fs is found, run the lazy initialization request
3780  * (ext4_rn_li_request) and keep track of the time spend in this
3781  * function. Based on that time we compute next schedule time of
3782  * the request. When walking through the list is complete, compute
3783  * next waking time and put itself into sleep.
3784  */
3785 static int ext4_lazyinit_thread(void *arg)
3786 {
3787 	struct ext4_lazy_init *eli = arg;
3788 	struct list_head *pos, *n;
3789 	struct ext4_li_request *elr;
3790 	unsigned long next_wakeup, cur;
3791 
3792 	BUG_ON(NULL == eli);
3793 	set_freezable();
3794 
3795 cont_thread:
3796 	while (true) {
3797 		next_wakeup = MAX_JIFFY_OFFSET;
3798 
3799 		mutex_lock(&eli->li_list_mtx);
3800 		if (list_empty(&eli->li_request_list)) {
3801 			mutex_unlock(&eli->li_list_mtx);
3802 			goto exit_thread;
3803 		}
3804 		list_for_each_safe(pos, n, &eli->li_request_list) {
3805 			int err = 0;
3806 			int progress = 0;
3807 			elr = list_entry(pos, struct ext4_li_request,
3808 					 lr_request);
3809 
3810 			if (time_before(jiffies, elr->lr_next_sched)) {
3811 				if (time_before(elr->lr_next_sched, next_wakeup))
3812 					next_wakeup = elr->lr_next_sched;
3813 				continue;
3814 			}
3815 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3816 				if (sb_start_write_trylock(elr->lr_super)) {
3817 					progress = 1;
3818 					/*
3819 					 * We hold sb->s_umount, sb can not
3820 					 * be removed from the list, it is
3821 					 * now safe to drop li_list_mtx
3822 					 */
3823 					mutex_unlock(&eli->li_list_mtx);
3824 					err = ext4_run_li_request(elr);
3825 					sb_end_write(elr->lr_super);
3826 					mutex_lock(&eli->li_list_mtx);
3827 					n = pos->next;
3828 				}
3829 				up_read((&elr->lr_super->s_umount));
3830 			}
3831 			/* error, remove the lazy_init job */
3832 			if (err) {
3833 				ext4_remove_li_request(elr);
3834 				continue;
3835 			}
3836 			if (!progress) {
3837 				elr->lr_next_sched = jiffies +
3838 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3839 			}
3840 			if (time_before(elr->lr_next_sched, next_wakeup))
3841 				next_wakeup = elr->lr_next_sched;
3842 		}
3843 		mutex_unlock(&eli->li_list_mtx);
3844 
3845 		try_to_freeze();
3846 
3847 		cur = jiffies;
3848 		if ((time_after_eq(cur, next_wakeup)) ||
3849 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3850 			cond_resched();
3851 			continue;
3852 		}
3853 
3854 		schedule_timeout_interruptible(next_wakeup - cur);
3855 
3856 		if (kthread_should_stop()) {
3857 			ext4_clear_request_list();
3858 			goto exit_thread;
3859 		}
3860 	}
3861 
3862 exit_thread:
3863 	/*
3864 	 * It looks like the request list is empty, but we need
3865 	 * to check it under the li_list_mtx lock, to prevent any
3866 	 * additions into it, and of course we should lock ext4_li_mtx
3867 	 * to atomically free the list and ext4_li_info, because at
3868 	 * this point another ext4 filesystem could be registering
3869 	 * new one.
3870 	 */
3871 	mutex_lock(&ext4_li_mtx);
3872 	mutex_lock(&eli->li_list_mtx);
3873 	if (!list_empty(&eli->li_request_list)) {
3874 		mutex_unlock(&eli->li_list_mtx);
3875 		mutex_unlock(&ext4_li_mtx);
3876 		goto cont_thread;
3877 	}
3878 	mutex_unlock(&eli->li_list_mtx);
3879 	kfree(ext4_li_info);
3880 	ext4_li_info = NULL;
3881 	mutex_unlock(&ext4_li_mtx);
3882 
3883 	return 0;
3884 }
3885 
3886 static void ext4_clear_request_list(void)
3887 {
3888 	struct list_head *pos, *n;
3889 	struct ext4_li_request *elr;
3890 
3891 	mutex_lock(&ext4_li_info->li_list_mtx);
3892 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3893 		elr = list_entry(pos, struct ext4_li_request,
3894 				 lr_request);
3895 		ext4_remove_li_request(elr);
3896 	}
3897 	mutex_unlock(&ext4_li_info->li_list_mtx);
3898 }
3899 
3900 static int ext4_run_lazyinit_thread(void)
3901 {
3902 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3903 					 ext4_li_info, "ext4lazyinit");
3904 	if (IS_ERR(ext4_lazyinit_task)) {
3905 		int err = PTR_ERR(ext4_lazyinit_task);
3906 		ext4_clear_request_list();
3907 		kfree(ext4_li_info);
3908 		ext4_li_info = NULL;
3909 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3910 				 "initialization thread\n",
3911 				 err);
3912 		return err;
3913 	}
3914 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3915 	return 0;
3916 }
3917 
3918 /*
3919  * Check whether it make sense to run itable init. thread or not.
3920  * If there is at least one uninitialized inode table, return
3921  * corresponding group number, else the loop goes through all
3922  * groups and return total number of groups.
3923  */
3924 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3925 {
3926 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3927 	struct ext4_group_desc *gdp = NULL;
3928 
3929 	if (!ext4_has_group_desc_csum(sb))
3930 		return ngroups;
3931 
3932 	for (group = 0; group < ngroups; group++) {
3933 		gdp = ext4_get_group_desc(sb, group, NULL);
3934 		if (!gdp)
3935 			continue;
3936 
3937 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3938 			break;
3939 	}
3940 
3941 	return group;
3942 }
3943 
3944 static int ext4_li_info_new(void)
3945 {
3946 	struct ext4_lazy_init *eli = NULL;
3947 
3948 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3949 	if (!eli)
3950 		return -ENOMEM;
3951 
3952 	INIT_LIST_HEAD(&eli->li_request_list);
3953 	mutex_init(&eli->li_list_mtx);
3954 
3955 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3956 
3957 	ext4_li_info = eli;
3958 
3959 	return 0;
3960 }
3961 
3962 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3963 					    ext4_group_t start)
3964 {
3965 	struct ext4_li_request *elr;
3966 
3967 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3968 	if (!elr)
3969 		return NULL;
3970 
3971 	elr->lr_super = sb;
3972 	elr->lr_first_not_zeroed = start;
3973 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3974 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3975 		elr->lr_next_group = start;
3976 	} else {
3977 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3978 	}
3979 
3980 	/*
3981 	 * Randomize first schedule time of the request to
3982 	 * spread the inode table initialization requests
3983 	 * better.
3984 	 */
3985 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3986 	return elr;
3987 }
3988 
3989 int ext4_register_li_request(struct super_block *sb,
3990 			     ext4_group_t first_not_zeroed)
3991 {
3992 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3993 	struct ext4_li_request *elr = NULL;
3994 	ext4_group_t ngroups = sbi->s_groups_count;
3995 	int ret = 0;
3996 
3997 	mutex_lock(&ext4_li_mtx);
3998 	if (sbi->s_li_request != NULL) {
3999 		/*
4000 		 * Reset timeout so it can be computed again, because
4001 		 * s_li_wait_mult might have changed.
4002 		 */
4003 		sbi->s_li_request->lr_timeout = 0;
4004 		goto out;
4005 	}
4006 
4007 	if (sb_rdonly(sb) ||
4008 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4009 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4010 		goto out;
4011 
4012 	elr = ext4_li_request_new(sb, first_not_zeroed);
4013 	if (!elr) {
4014 		ret = -ENOMEM;
4015 		goto out;
4016 	}
4017 
4018 	if (NULL == ext4_li_info) {
4019 		ret = ext4_li_info_new();
4020 		if (ret)
4021 			goto out;
4022 	}
4023 
4024 	mutex_lock(&ext4_li_info->li_list_mtx);
4025 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4026 	mutex_unlock(&ext4_li_info->li_list_mtx);
4027 
4028 	sbi->s_li_request = elr;
4029 	/*
4030 	 * set elr to NULL here since it has been inserted to
4031 	 * the request_list and the removal and free of it is
4032 	 * handled by ext4_clear_request_list from now on.
4033 	 */
4034 	elr = NULL;
4035 
4036 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4037 		ret = ext4_run_lazyinit_thread();
4038 		if (ret)
4039 			goto out;
4040 	}
4041 out:
4042 	mutex_unlock(&ext4_li_mtx);
4043 	if (ret)
4044 		kfree(elr);
4045 	return ret;
4046 }
4047 
4048 /*
4049  * We do not need to lock anything since this is called on
4050  * module unload.
4051  */
4052 static void ext4_destroy_lazyinit_thread(void)
4053 {
4054 	/*
4055 	 * If thread exited earlier
4056 	 * there's nothing to be done.
4057 	 */
4058 	if (!ext4_li_info || !ext4_lazyinit_task)
4059 		return;
4060 
4061 	kthread_stop(ext4_lazyinit_task);
4062 }
4063 
4064 static int set_journal_csum_feature_set(struct super_block *sb)
4065 {
4066 	int ret = 1;
4067 	int compat, incompat;
4068 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4069 
4070 	if (ext4_has_metadata_csum(sb)) {
4071 		/* journal checksum v3 */
4072 		compat = 0;
4073 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4074 	} else {
4075 		/* journal checksum v1 */
4076 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4077 		incompat = 0;
4078 	}
4079 
4080 	jbd2_journal_clear_features(sbi->s_journal,
4081 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4082 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4083 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4084 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4085 		ret = jbd2_journal_set_features(sbi->s_journal,
4086 				compat, 0,
4087 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4088 				incompat);
4089 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4090 		ret = jbd2_journal_set_features(sbi->s_journal,
4091 				compat, 0,
4092 				incompat);
4093 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4094 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4095 	} else {
4096 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4097 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4098 	}
4099 
4100 	return ret;
4101 }
4102 
4103 /*
4104  * Note: calculating the overhead so we can be compatible with
4105  * historical BSD practice is quite difficult in the face of
4106  * clusters/bigalloc.  This is because multiple metadata blocks from
4107  * different block group can end up in the same allocation cluster.
4108  * Calculating the exact overhead in the face of clustered allocation
4109  * requires either O(all block bitmaps) in memory or O(number of block
4110  * groups**2) in time.  We will still calculate the superblock for
4111  * older file systems --- and if we come across with a bigalloc file
4112  * system with zero in s_overhead_clusters the estimate will be close to
4113  * correct especially for very large cluster sizes --- but for newer
4114  * file systems, it's better to calculate this figure once at mkfs
4115  * time, and store it in the superblock.  If the superblock value is
4116  * present (even for non-bigalloc file systems), we will use it.
4117  */
4118 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4119 			  char *buf)
4120 {
4121 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4122 	struct ext4_group_desc	*gdp;
4123 	ext4_fsblk_t		first_block, last_block, b;
4124 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4125 	int			s, j, count = 0;
4126 	int			has_super = ext4_bg_has_super(sb, grp);
4127 
4128 	if (!ext4_has_feature_bigalloc(sb))
4129 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4130 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4131 			sbi->s_itb_per_group + 2);
4132 
4133 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4134 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4135 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4136 	for (i = 0; i < ngroups; i++) {
4137 		gdp = ext4_get_group_desc(sb, i, NULL);
4138 		b = ext4_block_bitmap(sb, gdp);
4139 		if (b >= first_block && b <= last_block) {
4140 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4141 			count++;
4142 		}
4143 		b = ext4_inode_bitmap(sb, gdp);
4144 		if (b >= first_block && b <= last_block) {
4145 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4146 			count++;
4147 		}
4148 		b = ext4_inode_table(sb, gdp);
4149 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4150 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4151 				int c = EXT4_B2C(sbi, b - first_block);
4152 				ext4_set_bit(c, buf);
4153 				count++;
4154 			}
4155 		if (i != grp)
4156 			continue;
4157 		s = 0;
4158 		if (ext4_bg_has_super(sb, grp)) {
4159 			ext4_set_bit(s++, buf);
4160 			count++;
4161 		}
4162 		j = ext4_bg_num_gdb(sb, grp);
4163 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4164 			ext4_error(sb, "Invalid number of block group "
4165 				   "descriptor blocks: %d", j);
4166 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4167 		}
4168 		count += j;
4169 		for (; j > 0; j--)
4170 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4171 	}
4172 	if (!count)
4173 		return 0;
4174 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4175 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4176 }
4177 
4178 /*
4179  * Compute the overhead and stash it in sbi->s_overhead
4180  */
4181 int ext4_calculate_overhead(struct super_block *sb)
4182 {
4183 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4184 	struct ext4_super_block *es = sbi->s_es;
4185 	struct inode *j_inode;
4186 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4187 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4188 	ext4_fsblk_t overhead = 0;
4189 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4190 
4191 	if (!buf)
4192 		return -ENOMEM;
4193 
4194 	/*
4195 	 * Compute the overhead (FS structures).  This is constant
4196 	 * for a given filesystem unless the number of block groups
4197 	 * changes so we cache the previous value until it does.
4198 	 */
4199 
4200 	/*
4201 	 * All of the blocks before first_data_block are overhead
4202 	 */
4203 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4204 
4205 	/*
4206 	 * Add the overhead found in each block group
4207 	 */
4208 	for (i = 0; i < ngroups; i++) {
4209 		int blks;
4210 
4211 		blks = count_overhead(sb, i, buf);
4212 		overhead += blks;
4213 		if (blks)
4214 			memset(buf, 0, PAGE_SIZE);
4215 		cond_resched();
4216 	}
4217 
4218 	/*
4219 	 * Add the internal journal blocks whether the journal has been
4220 	 * loaded or not
4221 	 */
4222 	if (sbi->s_journal && !sbi->s_journal_bdev)
4223 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4224 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4225 		/* j_inum for internal journal is non-zero */
4226 		j_inode = ext4_get_journal_inode(sb, j_inum);
4227 		if (j_inode) {
4228 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4229 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4230 			iput(j_inode);
4231 		} else {
4232 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4233 		}
4234 	}
4235 	sbi->s_overhead = overhead;
4236 	smp_wmb();
4237 	free_page((unsigned long) buf);
4238 	return 0;
4239 }
4240 
4241 static void ext4_set_resv_clusters(struct super_block *sb)
4242 {
4243 	ext4_fsblk_t resv_clusters;
4244 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4245 
4246 	/*
4247 	 * There's no need to reserve anything when we aren't using extents.
4248 	 * The space estimates are exact, there are no unwritten extents,
4249 	 * hole punching doesn't need new metadata... This is needed especially
4250 	 * to keep ext2/3 backward compatibility.
4251 	 */
4252 	if (!ext4_has_feature_extents(sb))
4253 		return;
4254 	/*
4255 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4256 	 * This should cover the situations where we can not afford to run
4257 	 * out of space like for example punch hole, or converting
4258 	 * unwritten extents in delalloc path. In most cases such
4259 	 * allocation would require 1, or 2 blocks, higher numbers are
4260 	 * very rare.
4261 	 */
4262 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4263 			 sbi->s_cluster_bits);
4264 
4265 	do_div(resv_clusters, 50);
4266 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4267 
4268 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4269 }
4270 
4271 static const char *ext4_quota_mode(struct super_block *sb)
4272 {
4273 #ifdef CONFIG_QUOTA
4274 	if (!ext4_quota_capable(sb))
4275 		return "none";
4276 
4277 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4278 		return "journalled";
4279 	else
4280 		return "writeback";
4281 #else
4282 	return "disabled";
4283 #endif
4284 }
4285 
4286 static void ext4_setup_csum_trigger(struct super_block *sb,
4287 				    enum ext4_journal_trigger_type type,
4288 				    void (*trigger)(
4289 					struct jbd2_buffer_trigger_type *type,
4290 					struct buffer_head *bh,
4291 					void *mapped_data,
4292 					size_t size))
4293 {
4294 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4295 
4296 	sbi->s_journal_triggers[type].sb = sb;
4297 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4298 }
4299 
4300 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4301 {
4302 	if (!sbi)
4303 		return;
4304 
4305 	kfree(sbi->s_blockgroup_lock);
4306 	fs_put_dax(sbi->s_daxdev, NULL);
4307 	kfree(sbi);
4308 }
4309 
4310 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4311 {
4312 	struct ext4_sb_info *sbi;
4313 
4314 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4315 	if (!sbi)
4316 		return NULL;
4317 
4318 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4319 					   NULL, NULL);
4320 
4321 	sbi->s_blockgroup_lock =
4322 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4323 
4324 	if (!sbi->s_blockgroup_lock)
4325 		goto err_out;
4326 
4327 	sb->s_fs_info = sbi;
4328 	sbi->s_sb = sb;
4329 	return sbi;
4330 err_out:
4331 	fs_put_dax(sbi->s_daxdev, NULL);
4332 	kfree(sbi);
4333 	return NULL;
4334 }
4335 
4336 static void ext4_set_def_opts(struct super_block *sb,
4337 			      struct ext4_super_block *es)
4338 {
4339 	unsigned long def_mount_opts;
4340 
4341 	/* Set defaults before we parse the mount options */
4342 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4343 	set_opt(sb, INIT_INODE_TABLE);
4344 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4345 		set_opt(sb, DEBUG);
4346 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4347 		set_opt(sb, GRPID);
4348 	if (def_mount_opts & EXT4_DEFM_UID16)
4349 		set_opt(sb, NO_UID32);
4350 	/* xattr user namespace & acls are now defaulted on */
4351 	set_opt(sb, XATTR_USER);
4352 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4353 	set_opt(sb, POSIX_ACL);
4354 #endif
4355 	if (ext4_has_feature_fast_commit(sb))
4356 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4357 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4358 	if (ext4_has_metadata_csum(sb))
4359 		set_opt(sb, JOURNAL_CHECKSUM);
4360 
4361 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4362 		set_opt(sb, JOURNAL_DATA);
4363 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4364 		set_opt(sb, ORDERED_DATA);
4365 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4366 		set_opt(sb, WRITEBACK_DATA);
4367 
4368 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4369 		set_opt(sb, ERRORS_PANIC);
4370 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4371 		set_opt(sb, ERRORS_CONT);
4372 	else
4373 		set_opt(sb, ERRORS_RO);
4374 	/* block_validity enabled by default; disable with noblock_validity */
4375 	set_opt(sb, BLOCK_VALIDITY);
4376 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4377 		set_opt(sb, DISCARD);
4378 
4379 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4380 		set_opt(sb, BARRIER);
4381 
4382 	/*
4383 	 * enable delayed allocation by default
4384 	 * Use -o nodelalloc to turn it off
4385 	 */
4386 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4387 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4388 		set_opt(sb, DELALLOC);
4389 
4390 	if (sb->s_blocksize == PAGE_SIZE)
4391 		set_opt(sb, DIOREAD_NOLOCK);
4392 }
4393 
4394 static int ext4_handle_clustersize(struct super_block *sb)
4395 {
4396 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4397 	struct ext4_super_block *es = sbi->s_es;
4398 	int clustersize;
4399 
4400 	/* Handle clustersize */
4401 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4402 	if (ext4_has_feature_bigalloc(sb)) {
4403 		if (clustersize < sb->s_blocksize) {
4404 			ext4_msg(sb, KERN_ERR,
4405 				 "cluster size (%d) smaller than "
4406 				 "block size (%lu)", clustersize, sb->s_blocksize);
4407 			return -EINVAL;
4408 		}
4409 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4410 			le32_to_cpu(es->s_log_block_size);
4411 		sbi->s_clusters_per_group =
4412 			le32_to_cpu(es->s_clusters_per_group);
4413 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4414 			ext4_msg(sb, KERN_ERR,
4415 				 "#clusters per group too big: %lu",
4416 				 sbi->s_clusters_per_group);
4417 			return -EINVAL;
4418 		}
4419 		if (sbi->s_blocks_per_group !=
4420 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4421 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4422 				 "clusters per group (%lu) inconsistent",
4423 				 sbi->s_blocks_per_group,
4424 				 sbi->s_clusters_per_group);
4425 			return -EINVAL;
4426 		}
4427 	} else {
4428 		if (clustersize != sb->s_blocksize) {
4429 			ext4_msg(sb, KERN_ERR,
4430 				 "fragment/cluster size (%d) != "
4431 				 "block size (%lu)", clustersize, sb->s_blocksize);
4432 			return -EINVAL;
4433 		}
4434 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4435 			ext4_msg(sb, KERN_ERR,
4436 				 "#blocks per group too big: %lu",
4437 				 sbi->s_blocks_per_group);
4438 			return -EINVAL;
4439 		}
4440 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4441 		sbi->s_cluster_bits = 0;
4442 	}
4443 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4444 
4445 	/* Do we have standard group size of clustersize * 8 blocks ? */
4446 	if (sbi->s_blocks_per_group == clustersize << 3)
4447 		set_opt2(sb, STD_GROUP_SIZE);
4448 
4449 	return 0;
4450 }
4451 
4452 static void ext4_fast_commit_init(struct super_block *sb)
4453 {
4454 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4455 
4456 	/* Initialize fast commit stuff */
4457 	atomic_set(&sbi->s_fc_subtid, 0);
4458 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4459 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4460 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4461 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4462 	sbi->s_fc_bytes = 0;
4463 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4464 	sbi->s_fc_ineligible_tid = 0;
4465 	spin_lock_init(&sbi->s_fc_lock);
4466 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4467 	sbi->s_fc_replay_state.fc_regions = NULL;
4468 	sbi->s_fc_replay_state.fc_regions_size = 0;
4469 	sbi->s_fc_replay_state.fc_regions_used = 0;
4470 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4471 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4472 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4473 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4474 }
4475 
4476 static int ext4_inode_info_init(struct super_block *sb,
4477 				struct ext4_super_block *es)
4478 {
4479 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4480 
4481 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4482 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4483 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4484 	} else {
4485 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4486 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4487 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4488 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4489 				 sbi->s_first_ino);
4490 			return -EINVAL;
4491 		}
4492 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4493 		    (!is_power_of_2(sbi->s_inode_size)) ||
4494 		    (sbi->s_inode_size > sb->s_blocksize)) {
4495 			ext4_msg(sb, KERN_ERR,
4496 			       "unsupported inode size: %d",
4497 			       sbi->s_inode_size);
4498 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4499 			return -EINVAL;
4500 		}
4501 		/*
4502 		 * i_atime_extra is the last extra field available for
4503 		 * [acm]times in struct ext4_inode. Checking for that
4504 		 * field should suffice to ensure we have extra space
4505 		 * for all three.
4506 		 */
4507 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4508 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4509 			sb->s_time_gran = 1;
4510 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4511 		} else {
4512 			sb->s_time_gran = NSEC_PER_SEC;
4513 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4514 		}
4515 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4516 	}
4517 
4518 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4519 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4520 			EXT4_GOOD_OLD_INODE_SIZE;
4521 		if (ext4_has_feature_extra_isize(sb)) {
4522 			unsigned v, max = (sbi->s_inode_size -
4523 					   EXT4_GOOD_OLD_INODE_SIZE);
4524 
4525 			v = le16_to_cpu(es->s_want_extra_isize);
4526 			if (v > max) {
4527 				ext4_msg(sb, KERN_ERR,
4528 					 "bad s_want_extra_isize: %d", v);
4529 				return -EINVAL;
4530 			}
4531 			if (sbi->s_want_extra_isize < v)
4532 				sbi->s_want_extra_isize = v;
4533 
4534 			v = le16_to_cpu(es->s_min_extra_isize);
4535 			if (v > max) {
4536 				ext4_msg(sb, KERN_ERR,
4537 					 "bad s_min_extra_isize: %d", v);
4538 				return -EINVAL;
4539 			}
4540 			if (sbi->s_want_extra_isize < v)
4541 				sbi->s_want_extra_isize = v;
4542 		}
4543 	}
4544 
4545 	return 0;
4546 }
4547 
4548 #if IS_ENABLED(CONFIG_UNICODE)
4549 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4550 {
4551 	const struct ext4_sb_encodings *encoding_info;
4552 	struct unicode_map *encoding;
4553 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4554 
4555 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4556 		return 0;
4557 
4558 	encoding_info = ext4_sb_read_encoding(es);
4559 	if (!encoding_info) {
4560 		ext4_msg(sb, KERN_ERR,
4561 			"Encoding requested by superblock is unknown");
4562 		return -EINVAL;
4563 	}
4564 
4565 	encoding = utf8_load(encoding_info->version);
4566 	if (IS_ERR(encoding)) {
4567 		ext4_msg(sb, KERN_ERR,
4568 			"can't mount with superblock charset: %s-%u.%u.%u "
4569 			"not supported by the kernel. flags: 0x%x.",
4570 			encoding_info->name,
4571 			unicode_major(encoding_info->version),
4572 			unicode_minor(encoding_info->version),
4573 			unicode_rev(encoding_info->version),
4574 			encoding_flags);
4575 		return -EINVAL;
4576 	}
4577 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4578 		"%s-%u.%u.%u with flags 0x%hx", 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 
4584 	sb->s_encoding = encoding;
4585 	sb->s_encoding_flags = encoding_flags;
4586 
4587 	return 0;
4588 }
4589 #else
4590 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4591 {
4592 	return 0;
4593 }
4594 #endif
4595 
4596 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4597 {
4598 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4599 
4600 	/* Warn if metadata_csum and gdt_csum are both set. */
4601 	if (ext4_has_feature_metadata_csum(sb) &&
4602 	    ext4_has_feature_gdt_csum(sb))
4603 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4604 			     "redundant flags; please run fsck.");
4605 
4606 	/* Check for a known checksum algorithm */
4607 	if (!ext4_verify_csum_type(sb, es)) {
4608 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4609 			 "unknown checksum algorithm.");
4610 		return -EINVAL;
4611 	}
4612 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4613 				ext4_orphan_file_block_trigger);
4614 
4615 	/* Load the checksum driver */
4616 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4617 	if (IS_ERR(sbi->s_chksum_driver)) {
4618 		int ret = PTR_ERR(sbi->s_chksum_driver);
4619 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4620 		sbi->s_chksum_driver = NULL;
4621 		return ret;
4622 	}
4623 
4624 	/* Check superblock checksum */
4625 	if (!ext4_superblock_csum_verify(sb, es)) {
4626 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4627 			 "invalid superblock checksum.  Run e2fsck?");
4628 		return -EFSBADCRC;
4629 	}
4630 
4631 	/* Precompute checksum seed for all metadata */
4632 	if (ext4_has_feature_csum_seed(sb))
4633 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4634 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4635 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4636 					       sizeof(es->s_uuid));
4637 	return 0;
4638 }
4639 
4640 static int ext4_check_feature_compatibility(struct super_block *sb,
4641 					    struct ext4_super_block *es,
4642 					    int silent)
4643 {
4644 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4645 
4646 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4647 	    (ext4_has_compat_features(sb) ||
4648 	     ext4_has_ro_compat_features(sb) ||
4649 	     ext4_has_incompat_features(sb)))
4650 		ext4_msg(sb, KERN_WARNING,
4651 		       "feature flags set on rev 0 fs, "
4652 		       "running e2fsck is recommended");
4653 
4654 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4655 		set_opt2(sb, HURD_COMPAT);
4656 		if (ext4_has_feature_64bit(sb)) {
4657 			ext4_msg(sb, KERN_ERR,
4658 				 "The Hurd can't support 64-bit file systems");
4659 			return -EINVAL;
4660 		}
4661 
4662 		/*
4663 		 * ea_inode feature uses l_i_version field which is not
4664 		 * available in HURD_COMPAT mode.
4665 		 */
4666 		if (ext4_has_feature_ea_inode(sb)) {
4667 			ext4_msg(sb, KERN_ERR,
4668 				 "ea_inode feature is not supported for Hurd");
4669 			return -EINVAL;
4670 		}
4671 	}
4672 
4673 	if (IS_EXT2_SB(sb)) {
4674 		if (ext2_feature_set_ok(sb))
4675 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4676 				 "using the ext4 subsystem");
4677 		else {
4678 			/*
4679 			 * If we're probing be silent, if this looks like
4680 			 * it's actually an ext[34] filesystem.
4681 			 */
4682 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4683 				return -EINVAL;
4684 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4685 				 "to feature incompatibilities");
4686 			return -EINVAL;
4687 		}
4688 	}
4689 
4690 	if (IS_EXT3_SB(sb)) {
4691 		if (ext3_feature_set_ok(sb))
4692 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4693 				 "using the ext4 subsystem");
4694 		else {
4695 			/*
4696 			 * If we're probing be silent, if this looks like
4697 			 * it's actually an ext4 filesystem.
4698 			 */
4699 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4700 				return -EINVAL;
4701 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4702 				 "to feature incompatibilities");
4703 			return -EINVAL;
4704 		}
4705 	}
4706 
4707 	/*
4708 	 * Check feature flags regardless of the revision level, since we
4709 	 * previously didn't change the revision level when setting the flags,
4710 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4711 	 */
4712 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4713 		return -EINVAL;
4714 
4715 	if (sbi->s_daxdev) {
4716 		if (sb->s_blocksize == PAGE_SIZE)
4717 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4718 		else
4719 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4720 	}
4721 
4722 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4723 		if (ext4_has_feature_inline_data(sb)) {
4724 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4725 					" that may contain inline data");
4726 			return -EINVAL;
4727 		}
4728 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4729 			ext4_msg(sb, KERN_ERR,
4730 				"DAX unsupported by block device.");
4731 			return -EINVAL;
4732 		}
4733 	}
4734 
4735 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4736 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4737 			 es->s_encryption_level);
4738 		return -EINVAL;
4739 	}
4740 
4741 	return 0;
4742 }
4743 
4744 static int ext4_check_geometry(struct super_block *sb,
4745 			       struct ext4_super_block *es)
4746 {
4747 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4748 	__u64 blocks_count;
4749 	int err;
4750 
4751 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4752 		ext4_msg(sb, KERN_ERR,
4753 			 "Number of reserved GDT blocks insanely large: %d",
4754 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4755 		return -EINVAL;
4756 	}
4757 	/*
4758 	 * Test whether we have more sectors than will fit in sector_t,
4759 	 * and whether the max offset is addressable by the page cache.
4760 	 */
4761 	err = generic_check_addressable(sb->s_blocksize_bits,
4762 					ext4_blocks_count(es));
4763 	if (err) {
4764 		ext4_msg(sb, KERN_ERR, "filesystem"
4765 			 " too large to mount safely on this system");
4766 		return err;
4767 	}
4768 
4769 	/* check blocks count against device size */
4770 	blocks_count = sb_bdev_nr_blocks(sb);
4771 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4772 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4773 		       "exceeds size of device (%llu blocks)",
4774 		       ext4_blocks_count(es), blocks_count);
4775 		return -EINVAL;
4776 	}
4777 
4778 	/*
4779 	 * It makes no sense for the first data block to be beyond the end
4780 	 * of the filesystem.
4781 	 */
4782 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4783 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4784 			 "block %u is beyond end of filesystem (%llu)",
4785 			 le32_to_cpu(es->s_first_data_block),
4786 			 ext4_blocks_count(es));
4787 		return -EINVAL;
4788 	}
4789 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4790 	    (sbi->s_cluster_ratio == 1)) {
4791 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4792 			 "block is 0 with a 1k block and cluster size");
4793 		return -EINVAL;
4794 	}
4795 
4796 	blocks_count = (ext4_blocks_count(es) -
4797 			le32_to_cpu(es->s_first_data_block) +
4798 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4799 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4800 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4801 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4802 		       "(block count %llu, first data block %u, "
4803 		       "blocks per group %lu)", blocks_count,
4804 		       ext4_blocks_count(es),
4805 		       le32_to_cpu(es->s_first_data_block),
4806 		       EXT4_BLOCKS_PER_GROUP(sb));
4807 		return -EINVAL;
4808 	}
4809 	sbi->s_groups_count = blocks_count;
4810 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4811 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4812 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4813 	    le32_to_cpu(es->s_inodes_count)) {
4814 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4815 			 le32_to_cpu(es->s_inodes_count),
4816 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4817 		return -EINVAL;
4818 	}
4819 
4820 	return 0;
4821 }
4822 
4823 static int ext4_group_desc_init(struct super_block *sb,
4824 				struct ext4_super_block *es,
4825 				ext4_fsblk_t logical_sb_block,
4826 				ext4_group_t *first_not_zeroed)
4827 {
4828 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4829 	unsigned int db_count;
4830 	ext4_fsblk_t block;
4831 	int i;
4832 
4833 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4834 		   EXT4_DESC_PER_BLOCK(sb);
4835 	if (ext4_has_feature_meta_bg(sb)) {
4836 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4837 			ext4_msg(sb, KERN_WARNING,
4838 				 "first meta block group too large: %u "
4839 				 "(group descriptor block count %u)",
4840 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4841 			return -EINVAL;
4842 		}
4843 	}
4844 	rcu_assign_pointer(sbi->s_group_desc,
4845 			   kvmalloc_array(db_count,
4846 					  sizeof(struct buffer_head *),
4847 					  GFP_KERNEL));
4848 	if (sbi->s_group_desc == NULL) {
4849 		ext4_msg(sb, KERN_ERR, "not enough memory");
4850 		return -ENOMEM;
4851 	}
4852 
4853 	bgl_lock_init(sbi->s_blockgroup_lock);
4854 
4855 	/* Pre-read the descriptors into the buffer cache */
4856 	for (i = 0; i < db_count; i++) {
4857 		block = descriptor_loc(sb, logical_sb_block, i);
4858 		ext4_sb_breadahead_unmovable(sb, block);
4859 	}
4860 
4861 	for (i = 0; i < db_count; i++) {
4862 		struct buffer_head *bh;
4863 
4864 		block = descriptor_loc(sb, logical_sb_block, i);
4865 		bh = ext4_sb_bread_unmovable(sb, block);
4866 		if (IS_ERR(bh)) {
4867 			ext4_msg(sb, KERN_ERR,
4868 			       "can't read group descriptor %d", i);
4869 			sbi->s_gdb_count = i;
4870 			return PTR_ERR(bh);
4871 		}
4872 		rcu_read_lock();
4873 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4874 		rcu_read_unlock();
4875 	}
4876 	sbi->s_gdb_count = db_count;
4877 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4878 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4879 		return -EFSCORRUPTED;
4880 	}
4881 
4882 	return 0;
4883 }
4884 
4885 static int ext4_load_and_init_journal(struct super_block *sb,
4886 				      struct ext4_super_block *es,
4887 				      struct ext4_fs_context *ctx)
4888 {
4889 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4890 	int err;
4891 
4892 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4893 	if (err)
4894 		return err;
4895 
4896 	if (ext4_has_feature_64bit(sb) &&
4897 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4898 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4899 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4900 		goto out;
4901 	}
4902 
4903 	if (!set_journal_csum_feature_set(sb)) {
4904 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4905 			 "feature set");
4906 		goto out;
4907 	}
4908 
4909 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4910 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4911 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4912 		ext4_msg(sb, KERN_ERR,
4913 			"Failed to set fast commit journal feature");
4914 		goto out;
4915 	}
4916 
4917 	/* We have now updated the journal if required, so we can
4918 	 * validate the data journaling mode. */
4919 	switch (test_opt(sb, DATA_FLAGS)) {
4920 	case 0:
4921 		/* No mode set, assume a default based on the journal
4922 		 * capabilities: ORDERED_DATA if the journal can
4923 		 * cope, else JOURNAL_DATA
4924 		 */
4925 		if (jbd2_journal_check_available_features
4926 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4927 			set_opt(sb, ORDERED_DATA);
4928 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4929 		} else {
4930 			set_opt(sb, JOURNAL_DATA);
4931 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4932 		}
4933 		break;
4934 
4935 	case EXT4_MOUNT_ORDERED_DATA:
4936 	case EXT4_MOUNT_WRITEBACK_DATA:
4937 		if (!jbd2_journal_check_available_features
4938 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4939 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4940 			       "requested data journaling mode");
4941 			goto out;
4942 		}
4943 		break;
4944 	default:
4945 		break;
4946 	}
4947 
4948 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4949 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4950 		ext4_msg(sb, KERN_ERR, "can't mount with "
4951 			"journal_async_commit in data=ordered mode");
4952 		goto out;
4953 	}
4954 
4955 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4956 
4957 	sbi->s_journal->j_submit_inode_data_buffers =
4958 		ext4_journal_submit_inode_data_buffers;
4959 	sbi->s_journal->j_finish_inode_data_buffers =
4960 		ext4_journal_finish_inode_data_buffers;
4961 
4962 	return 0;
4963 
4964 out:
4965 	/* flush s_error_work before journal destroy. */
4966 	flush_work(&sbi->s_error_work);
4967 	jbd2_journal_destroy(sbi->s_journal);
4968 	sbi->s_journal = NULL;
4969 	return -EINVAL;
4970 }
4971 
4972 static int ext4_check_journal_data_mode(struct super_block *sb)
4973 {
4974 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4975 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4976 			    "data=journal disables delayed allocation, "
4977 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4978 		/* can't mount with both data=journal and dioread_nolock. */
4979 		clear_opt(sb, DIOREAD_NOLOCK);
4980 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4981 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4982 			ext4_msg(sb, KERN_ERR, "can't mount with "
4983 				 "both data=journal and delalloc");
4984 			return -EINVAL;
4985 		}
4986 		if (test_opt(sb, DAX_ALWAYS)) {
4987 			ext4_msg(sb, KERN_ERR, "can't mount with "
4988 				 "both data=journal and dax");
4989 			return -EINVAL;
4990 		}
4991 		if (ext4_has_feature_encrypt(sb)) {
4992 			ext4_msg(sb, KERN_WARNING,
4993 				 "encrypted files will use data=ordered "
4994 				 "instead of data journaling mode");
4995 		}
4996 		if (test_opt(sb, DELALLOC))
4997 			clear_opt(sb, DELALLOC);
4998 	} else {
4999 		sb->s_iflags |= SB_I_CGROUPWB;
5000 	}
5001 
5002 	return 0;
5003 }
5004 
5005 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5006 			   int silent)
5007 {
5008 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5009 	struct ext4_super_block *es;
5010 	ext4_fsblk_t logical_sb_block;
5011 	unsigned long offset = 0;
5012 	struct buffer_head *bh;
5013 	int ret = -EINVAL;
5014 	int blocksize;
5015 
5016 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5017 	if (!blocksize) {
5018 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5019 		return -EINVAL;
5020 	}
5021 
5022 	/*
5023 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5024 	 * block sizes.  We need to calculate the offset from buffer start.
5025 	 */
5026 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5027 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5028 		offset = do_div(logical_sb_block, blocksize);
5029 	} else {
5030 		logical_sb_block = sbi->s_sb_block;
5031 	}
5032 
5033 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5034 	if (IS_ERR(bh)) {
5035 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5036 		return PTR_ERR(bh);
5037 	}
5038 	/*
5039 	 * Note: s_es must be initialized as soon as possible because
5040 	 *       some ext4 macro-instructions depend on its value
5041 	 */
5042 	es = (struct ext4_super_block *) (bh->b_data + offset);
5043 	sbi->s_es = es;
5044 	sb->s_magic = le16_to_cpu(es->s_magic);
5045 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5046 		if (!silent)
5047 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5048 		goto out;
5049 	}
5050 
5051 	if (le32_to_cpu(es->s_log_block_size) >
5052 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5053 		ext4_msg(sb, KERN_ERR,
5054 			 "Invalid log block size: %u",
5055 			 le32_to_cpu(es->s_log_block_size));
5056 		goto out;
5057 	}
5058 	if (le32_to_cpu(es->s_log_cluster_size) >
5059 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5060 		ext4_msg(sb, KERN_ERR,
5061 			 "Invalid log cluster size: %u",
5062 			 le32_to_cpu(es->s_log_cluster_size));
5063 		goto out;
5064 	}
5065 
5066 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5067 
5068 	/*
5069 	 * If the default block size is not the same as the real block size,
5070 	 * we need to reload it.
5071 	 */
5072 	if (sb->s_blocksize == blocksize) {
5073 		*lsb = logical_sb_block;
5074 		sbi->s_sbh = bh;
5075 		return 0;
5076 	}
5077 
5078 	/*
5079 	 * bh must be released before kill_bdev(), otherwise
5080 	 * it won't be freed and its page also. kill_bdev()
5081 	 * is called by sb_set_blocksize().
5082 	 */
5083 	brelse(bh);
5084 	/* Validate the filesystem blocksize */
5085 	if (!sb_set_blocksize(sb, blocksize)) {
5086 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5087 				blocksize);
5088 		bh = NULL;
5089 		goto out;
5090 	}
5091 
5092 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5093 	offset = do_div(logical_sb_block, blocksize);
5094 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5095 	if (IS_ERR(bh)) {
5096 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5097 		ret = PTR_ERR(bh);
5098 		bh = NULL;
5099 		goto out;
5100 	}
5101 	es = (struct ext4_super_block *)(bh->b_data + offset);
5102 	sbi->s_es = es;
5103 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5104 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5105 		goto out;
5106 	}
5107 	*lsb = logical_sb_block;
5108 	sbi->s_sbh = bh;
5109 	return 0;
5110 out:
5111 	brelse(bh);
5112 	return ret;
5113 }
5114 
5115 static void ext4_hash_info_init(struct super_block *sb)
5116 {
5117 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5118 	struct ext4_super_block *es = sbi->s_es;
5119 	unsigned int i;
5120 
5121 	for (i = 0; i < 4; i++)
5122 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5123 
5124 	sbi->s_def_hash_version = es->s_def_hash_version;
5125 	if (ext4_has_feature_dir_index(sb)) {
5126 		i = le32_to_cpu(es->s_flags);
5127 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5128 			sbi->s_hash_unsigned = 3;
5129 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5130 #ifdef __CHAR_UNSIGNED__
5131 			if (!sb_rdonly(sb))
5132 				es->s_flags |=
5133 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5134 			sbi->s_hash_unsigned = 3;
5135 #else
5136 			if (!sb_rdonly(sb))
5137 				es->s_flags |=
5138 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5139 #endif
5140 		}
5141 	}
5142 }
5143 
5144 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5145 {
5146 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5147 	struct ext4_super_block *es = sbi->s_es;
5148 	int has_huge_files;
5149 
5150 	has_huge_files = ext4_has_feature_huge_file(sb);
5151 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5152 						      has_huge_files);
5153 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5154 
5155 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5156 	if (ext4_has_feature_64bit(sb)) {
5157 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5158 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5159 		    !is_power_of_2(sbi->s_desc_size)) {
5160 			ext4_msg(sb, KERN_ERR,
5161 			       "unsupported descriptor size %lu",
5162 			       sbi->s_desc_size);
5163 			return -EINVAL;
5164 		}
5165 	} else
5166 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5167 
5168 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5169 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5170 
5171 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5172 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5173 		if (!silent)
5174 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5175 		return -EINVAL;
5176 	}
5177 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5178 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5179 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5180 			 sbi->s_inodes_per_group);
5181 		return -EINVAL;
5182 	}
5183 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5184 					sbi->s_inodes_per_block;
5185 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5186 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5187 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5188 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5189 
5190 	return 0;
5191 }
5192 
5193 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5194 {
5195 	struct ext4_super_block *es = NULL;
5196 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5197 	ext4_fsblk_t logical_sb_block;
5198 	struct inode *root;
5199 	int ret = -ENOMEM;
5200 	unsigned int i;
5201 	int needs_recovery;
5202 	int err = 0;
5203 	ext4_group_t first_not_zeroed;
5204 	struct ext4_fs_context *ctx = fc->fs_private;
5205 	int silent = fc->sb_flags & SB_SILENT;
5206 
5207 	/* Set defaults for the variables that will be set during parsing */
5208 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5209 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5210 
5211 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5212 	sbi->s_sectors_written_start =
5213 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5214 
5215 	/* -EINVAL is default */
5216 	ret = -EINVAL;
5217 	err = ext4_load_super(sb, &logical_sb_block, silent);
5218 	if (err)
5219 		goto out_fail;
5220 
5221 	es = sbi->s_es;
5222 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5223 
5224 	err = ext4_init_metadata_csum(sb, es);
5225 	if (err)
5226 		goto failed_mount;
5227 
5228 	ext4_set_def_opts(sb, es);
5229 
5230 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5231 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5232 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5233 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5234 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5235 
5236 	/*
5237 	 * set default s_li_wait_mult for lazyinit, for the case there is
5238 	 * no mount option specified.
5239 	 */
5240 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5241 
5242 	if (ext4_inode_info_init(sb, es))
5243 		goto failed_mount;
5244 
5245 	err = parse_apply_sb_mount_options(sb, ctx);
5246 	if (err < 0)
5247 		goto failed_mount;
5248 
5249 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5250 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5251 
5252 	err = ext4_check_opt_consistency(fc, sb);
5253 	if (err < 0)
5254 		goto failed_mount;
5255 
5256 	ext4_apply_options(fc, sb);
5257 
5258 	if (ext4_encoding_init(sb, es))
5259 		goto failed_mount;
5260 
5261 	if (ext4_check_journal_data_mode(sb))
5262 		goto failed_mount;
5263 
5264 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5265 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5266 
5267 	/* i_version is always enabled now */
5268 	sb->s_flags |= SB_I_VERSION;
5269 
5270 	if (ext4_check_feature_compatibility(sb, es, silent))
5271 		goto failed_mount;
5272 
5273 	if (ext4_block_group_meta_init(sb, silent))
5274 		goto failed_mount;
5275 
5276 	ext4_hash_info_init(sb);
5277 
5278 	if (ext4_handle_clustersize(sb))
5279 		goto failed_mount;
5280 
5281 	if (ext4_check_geometry(sb, es))
5282 		goto failed_mount;
5283 
5284 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5285 	spin_lock_init(&sbi->s_error_lock);
5286 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5287 
5288 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5289 	if (err)
5290 		goto failed_mount3;
5291 
5292 	/* Register extent status tree shrinker */
5293 	if (ext4_es_register_shrinker(sbi))
5294 		goto failed_mount3;
5295 
5296 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5297 	sbi->s_extent_max_zeroout_kb = 32;
5298 
5299 	/*
5300 	 * set up enough so that it can read an inode
5301 	 */
5302 	sb->s_op = &ext4_sops;
5303 	sb->s_export_op = &ext4_export_ops;
5304 	sb->s_xattr = ext4_xattr_handlers;
5305 #ifdef CONFIG_FS_ENCRYPTION
5306 	sb->s_cop = &ext4_cryptops;
5307 #endif
5308 #ifdef CONFIG_FS_VERITY
5309 	sb->s_vop = &ext4_verityops;
5310 #endif
5311 #ifdef CONFIG_QUOTA
5312 	sb->dq_op = &ext4_quota_operations;
5313 	if (ext4_has_feature_quota(sb))
5314 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5315 	else
5316 		sb->s_qcop = &ext4_qctl_operations;
5317 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5318 #endif
5319 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5320 
5321 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5322 	mutex_init(&sbi->s_orphan_lock);
5323 
5324 	ext4_fast_commit_init(sb);
5325 
5326 	sb->s_root = NULL;
5327 
5328 	needs_recovery = (es->s_last_orphan != 0 ||
5329 			  ext4_has_feature_orphan_present(sb) ||
5330 			  ext4_has_feature_journal_needs_recovery(sb));
5331 
5332 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5333 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5334 			goto failed_mount3a;
5335 
5336 	/*
5337 	 * The first inode we look at is the journal inode.  Don't try
5338 	 * root first: it may be modified in the journal!
5339 	 */
5340 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5341 		err = ext4_load_and_init_journal(sb, es, ctx);
5342 		if (err)
5343 			goto failed_mount3a;
5344 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5345 		   ext4_has_feature_journal_needs_recovery(sb)) {
5346 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5347 		       "suppressed and not mounted read-only");
5348 		goto failed_mount3a;
5349 	} else {
5350 		/* Nojournal mode, all journal mount options are illegal */
5351 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5352 			ext4_msg(sb, KERN_ERR, "can't mount with "
5353 				 "journal_async_commit, fs mounted w/o journal");
5354 			goto failed_mount3a;
5355 		}
5356 
5357 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5358 			ext4_msg(sb, KERN_ERR, "can't mount with "
5359 				 "journal_checksum, fs mounted w/o journal");
5360 			goto failed_mount3a;
5361 		}
5362 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5363 			ext4_msg(sb, KERN_ERR, "can't mount with "
5364 				 "commit=%lu, fs mounted w/o journal",
5365 				 sbi->s_commit_interval / HZ);
5366 			goto failed_mount3a;
5367 		}
5368 		if (EXT4_MOUNT_DATA_FLAGS &
5369 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5370 			ext4_msg(sb, KERN_ERR, "can't mount with "
5371 				 "data=, fs mounted w/o journal");
5372 			goto failed_mount3a;
5373 		}
5374 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5375 		clear_opt(sb, JOURNAL_CHECKSUM);
5376 		clear_opt(sb, DATA_FLAGS);
5377 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5378 		sbi->s_journal = NULL;
5379 		needs_recovery = 0;
5380 	}
5381 
5382 	if (!test_opt(sb, NO_MBCACHE)) {
5383 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5384 		if (!sbi->s_ea_block_cache) {
5385 			ext4_msg(sb, KERN_ERR,
5386 				 "Failed to create ea_block_cache");
5387 			goto failed_mount_wq;
5388 		}
5389 
5390 		if (ext4_has_feature_ea_inode(sb)) {
5391 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5392 			if (!sbi->s_ea_inode_cache) {
5393 				ext4_msg(sb, KERN_ERR,
5394 					 "Failed to create ea_inode_cache");
5395 				goto failed_mount_wq;
5396 			}
5397 		}
5398 	}
5399 
5400 	/*
5401 	 * Get the # of file system overhead blocks from the
5402 	 * superblock if present.
5403 	 */
5404 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5405 	/* ignore the precalculated value if it is ridiculous */
5406 	if (sbi->s_overhead > ext4_blocks_count(es))
5407 		sbi->s_overhead = 0;
5408 	/*
5409 	 * If the bigalloc feature is not enabled recalculating the
5410 	 * overhead doesn't take long, so we might as well just redo
5411 	 * it to make sure we are using the correct value.
5412 	 */
5413 	if (!ext4_has_feature_bigalloc(sb))
5414 		sbi->s_overhead = 0;
5415 	if (sbi->s_overhead == 0) {
5416 		err = ext4_calculate_overhead(sb);
5417 		if (err)
5418 			goto failed_mount_wq;
5419 	}
5420 
5421 	/*
5422 	 * The maximum number of concurrent works can be high and
5423 	 * concurrency isn't really necessary.  Limit it to 1.
5424 	 */
5425 	EXT4_SB(sb)->rsv_conversion_wq =
5426 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5427 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5428 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5429 		ret = -ENOMEM;
5430 		goto failed_mount4;
5431 	}
5432 
5433 	/*
5434 	 * The jbd2_journal_load will have done any necessary log recovery,
5435 	 * so we can safely mount the rest of the filesystem now.
5436 	 */
5437 
5438 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5439 	if (IS_ERR(root)) {
5440 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5441 		ret = PTR_ERR(root);
5442 		root = NULL;
5443 		goto failed_mount4;
5444 	}
5445 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5446 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5447 		iput(root);
5448 		goto failed_mount4;
5449 	}
5450 
5451 	sb->s_root = d_make_root(root);
5452 	if (!sb->s_root) {
5453 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5454 		ret = -ENOMEM;
5455 		goto failed_mount4;
5456 	}
5457 
5458 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5459 	if (ret == -EROFS) {
5460 		sb->s_flags |= SB_RDONLY;
5461 		ret = 0;
5462 	} else if (ret)
5463 		goto failed_mount4a;
5464 
5465 	ext4_set_resv_clusters(sb);
5466 
5467 	if (test_opt(sb, BLOCK_VALIDITY)) {
5468 		err = ext4_setup_system_zone(sb);
5469 		if (err) {
5470 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5471 				 "zone (%d)", err);
5472 			goto failed_mount4a;
5473 		}
5474 	}
5475 	ext4_fc_replay_cleanup(sb);
5476 
5477 	ext4_ext_init(sb);
5478 
5479 	/*
5480 	 * Enable optimize_scan if number of groups is > threshold. This can be
5481 	 * turned off by passing "mb_optimize_scan=0". This can also be
5482 	 * turned on forcefully by passing "mb_optimize_scan=1".
5483 	 */
5484 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5485 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5486 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5487 		else
5488 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5489 	}
5490 
5491 	err = ext4_mb_init(sb);
5492 	if (err) {
5493 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5494 			 err);
5495 		goto failed_mount5;
5496 	}
5497 
5498 	/*
5499 	 * We can only set up the journal commit callback once
5500 	 * mballoc is initialized
5501 	 */
5502 	if (sbi->s_journal)
5503 		sbi->s_journal->j_commit_callback =
5504 			ext4_journal_commit_callback;
5505 
5506 	if (ext4_percpu_param_init(sbi))
5507 		goto failed_mount6;
5508 
5509 	if (ext4_has_feature_flex_bg(sb))
5510 		if (!ext4_fill_flex_info(sb)) {
5511 			ext4_msg(sb, KERN_ERR,
5512 			       "unable to initialize "
5513 			       "flex_bg meta info!");
5514 			ret = -ENOMEM;
5515 			goto failed_mount6;
5516 		}
5517 
5518 	err = ext4_register_li_request(sb, first_not_zeroed);
5519 	if (err)
5520 		goto failed_mount6;
5521 
5522 	err = ext4_register_sysfs(sb);
5523 	if (err)
5524 		goto failed_mount7;
5525 
5526 	err = ext4_init_orphan_info(sb);
5527 	if (err)
5528 		goto failed_mount8;
5529 #ifdef CONFIG_QUOTA
5530 	/* Enable quota usage during mount. */
5531 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5532 		err = ext4_enable_quotas(sb);
5533 		if (err)
5534 			goto failed_mount9;
5535 	}
5536 #endif  /* CONFIG_QUOTA */
5537 
5538 	/*
5539 	 * Save the original bdev mapping's wb_err value which could be
5540 	 * used to detect the metadata async write error.
5541 	 */
5542 	spin_lock_init(&sbi->s_bdev_wb_lock);
5543 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5544 				 &sbi->s_bdev_wb_err);
5545 	sb->s_bdev->bd_super = sb;
5546 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5547 	ext4_orphan_cleanup(sb, es);
5548 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5549 	/*
5550 	 * Update the checksum after updating free space/inode counters and
5551 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5552 	 * checksum in the buffer cache until it is written out and
5553 	 * e2fsprogs programs trying to open a file system immediately
5554 	 * after it is mounted can fail.
5555 	 */
5556 	ext4_superblock_csum_set(sb);
5557 	if (needs_recovery) {
5558 		ext4_msg(sb, KERN_INFO, "recovery complete");
5559 		err = ext4_mark_recovery_complete(sb, es);
5560 		if (err)
5561 			goto failed_mount9;
5562 	}
5563 
5564 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5565 		ext4_msg(sb, KERN_WARNING,
5566 			 "mounting with \"discard\" option, but the device does not support discard");
5567 
5568 	if (es->s_error_count)
5569 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5570 
5571 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5572 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5573 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5574 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5575 	atomic_set(&sbi->s_warning_count, 0);
5576 	atomic_set(&sbi->s_msg_count, 0);
5577 
5578 	return 0;
5579 
5580 failed_mount9:
5581 	ext4_release_orphan_info(sb);
5582 failed_mount8:
5583 	ext4_unregister_sysfs(sb);
5584 	kobject_put(&sbi->s_kobj);
5585 failed_mount7:
5586 	ext4_unregister_li_request(sb);
5587 failed_mount6:
5588 	ext4_mb_release(sb);
5589 	ext4_flex_groups_free(sbi);
5590 	ext4_percpu_param_destroy(sbi);
5591 failed_mount5:
5592 	ext4_ext_release(sb);
5593 	ext4_release_system_zone(sb);
5594 failed_mount4a:
5595 	dput(sb->s_root);
5596 	sb->s_root = NULL;
5597 failed_mount4:
5598 	ext4_msg(sb, KERN_ERR, "mount failed");
5599 	if (EXT4_SB(sb)->rsv_conversion_wq)
5600 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5601 failed_mount_wq:
5602 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5603 	sbi->s_ea_inode_cache = NULL;
5604 
5605 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5606 	sbi->s_ea_block_cache = NULL;
5607 
5608 	if (sbi->s_journal) {
5609 		/* flush s_error_work before journal destroy. */
5610 		flush_work(&sbi->s_error_work);
5611 		jbd2_journal_destroy(sbi->s_journal);
5612 		sbi->s_journal = NULL;
5613 	}
5614 failed_mount3a:
5615 	ext4_es_unregister_shrinker(sbi);
5616 failed_mount3:
5617 	/* flush s_error_work before sbi destroy */
5618 	flush_work(&sbi->s_error_work);
5619 	del_timer_sync(&sbi->s_err_report);
5620 	ext4_stop_mmpd(sbi);
5621 	ext4_group_desc_free(sbi);
5622 failed_mount:
5623 	if (sbi->s_chksum_driver)
5624 		crypto_free_shash(sbi->s_chksum_driver);
5625 
5626 #if IS_ENABLED(CONFIG_UNICODE)
5627 	utf8_unload(sb->s_encoding);
5628 #endif
5629 
5630 #ifdef CONFIG_QUOTA
5631 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5632 		kfree(get_qf_name(sb, sbi, i));
5633 #endif
5634 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5635 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5636 	brelse(sbi->s_sbh);
5637 	ext4_blkdev_remove(sbi);
5638 out_fail:
5639 	sb->s_fs_info = NULL;
5640 	return err ? err : ret;
5641 }
5642 
5643 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5644 {
5645 	struct ext4_fs_context *ctx = fc->fs_private;
5646 	struct ext4_sb_info *sbi;
5647 	const char *descr;
5648 	int ret;
5649 
5650 	sbi = ext4_alloc_sbi(sb);
5651 	if (!sbi)
5652 		return -ENOMEM;
5653 
5654 	fc->s_fs_info = sbi;
5655 
5656 	/* Cleanup superblock name */
5657 	strreplace(sb->s_id, '/', '!');
5658 
5659 	sbi->s_sb_block = 1;	/* Default super block location */
5660 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5661 		sbi->s_sb_block = ctx->s_sb_block;
5662 
5663 	ret = __ext4_fill_super(fc, sb);
5664 	if (ret < 0)
5665 		goto free_sbi;
5666 
5667 	if (sbi->s_journal) {
5668 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5669 			descr = " journalled data mode";
5670 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5671 			descr = " ordered data mode";
5672 		else
5673 			descr = " writeback data mode";
5674 	} else
5675 		descr = "out journal";
5676 
5677 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5678 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU with%s. "
5679 			 "Quota mode: %s.", &sb->s_uuid, descr,
5680 			 ext4_quota_mode(sb));
5681 
5682 	/* Update the s_overhead_clusters if necessary */
5683 	ext4_update_overhead(sb, false);
5684 	return 0;
5685 
5686 free_sbi:
5687 	ext4_free_sbi(sbi);
5688 	fc->s_fs_info = NULL;
5689 	return ret;
5690 }
5691 
5692 static int ext4_get_tree(struct fs_context *fc)
5693 {
5694 	return get_tree_bdev(fc, ext4_fill_super);
5695 }
5696 
5697 /*
5698  * Setup any per-fs journal parameters now.  We'll do this both on
5699  * initial mount, once the journal has been initialised but before we've
5700  * done any recovery; and again on any subsequent remount.
5701  */
5702 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5703 {
5704 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5705 
5706 	journal->j_commit_interval = sbi->s_commit_interval;
5707 	journal->j_min_batch_time = sbi->s_min_batch_time;
5708 	journal->j_max_batch_time = sbi->s_max_batch_time;
5709 	ext4_fc_init(sb, journal);
5710 
5711 	write_lock(&journal->j_state_lock);
5712 	if (test_opt(sb, BARRIER))
5713 		journal->j_flags |= JBD2_BARRIER;
5714 	else
5715 		journal->j_flags &= ~JBD2_BARRIER;
5716 	if (test_opt(sb, DATA_ERR_ABORT))
5717 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5718 	else
5719 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5720 	write_unlock(&journal->j_state_lock);
5721 }
5722 
5723 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5724 					     unsigned int journal_inum)
5725 {
5726 	struct inode *journal_inode;
5727 
5728 	/*
5729 	 * Test for the existence of a valid inode on disk.  Bad things
5730 	 * happen if we iget() an unused inode, as the subsequent iput()
5731 	 * will try to delete it.
5732 	 */
5733 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5734 	if (IS_ERR(journal_inode)) {
5735 		ext4_msg(sb, KERN_ERR, "no journal found");
5736 		return NULL;
5737 	}
5738 	if (!journal_inode->i_nlink) {
5739 		make_bad_inode(journal_inode);
5740 		iput(journal_inode);
5741 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5742 		return NULL;
5743 	}
5744 
5745 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5746 		  journal_inode, journal_inode->i_size);
5747 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5748 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5749 		iput(journal_inode);
5750 		return NULL;
5751 	}
5752 	return journal_inode;
5753 }
5754 
5755 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5756 {
5757 	struct ext4_map_blocks map;
5758 	int ret;
5759 
5760 	if (journal->j_inode == NULL)
5761 		return 0;
5762 
5763 	map.m_lblk = *block;
5764 	map.m_len = 1;
5765 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5766 	if (ret <= 0) {
5767 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5768 			 "journal bmap failed: block %llu ret %d\n",
5769 			 *block, ret);
5770 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5771 		return ret;
5772 	}
5773 	*block = map.m_pblk;
5774 	return 0;
5775 }
5776 
5777 static journal_t *ext4_get_journal(struct super_block *sb,
5778 				   unsigned int journal_inum)
5779 {
5780 	struct inode *journal_inode;
5781 	journal_t *journal;
5782 
5783 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5784 		return NULL;
5785 
5786 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5787 	if (!journal_inode)
5788 		return NULL;
5789 
5790 	journal = jbd2_journal_init_inode(journal_inode);
5791 	if (!journal) {
5792 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5793 		iput(journal_inode);
5794 		return NULL;
5795 	}
5796 	journal->j_private = sb;
5797 	journal->j_bmap = ext4_journal_bmap;
5798 	ext4_init_journal_params(sb, journal);
5799 	return journal;
5800 }
5801 
5802 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5803 				       dev_t j_dev)
5804 {
5805 	struct buffer_head *bh;
5806 	journal_t *journal;
5807 	ext4_fsblk_t start;
5808 	ext4_fsblk_t len;
5809 	int hblock, blocksize;
5810 	ext4_fsblk_t sb_block;
5811 	unsigned long offset;
5812 	struct ext4_super_block *es;
5813 	struct block_device *bdev;
5814 
5815 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5816 		return NULL;
5817 
5818 	bdev = ext4_blkdev_get(j_dev, sb);
5819 	if (bdev == NULL)
5820 		return NULL;
5821 
5822 	blocksize = sb->s_blocksize;
5823 	hblock = bdev_logical_block_size(bdev);
5824 	if (blocksize < hblock) {
5825 		ext4_msg(sb, KERN_ERR,
5826 			"blocksize too small for journal device");
5827 		goto out_bdev;
5828 	}
5829 
5830 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5831 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5832 	set_blocksize(bdev, blocksize);
5833 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5834 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5835 		       "external journal");
5836 		goto out_bdev;
5837 	}
5838 
5839 	es = (struct ext4_super_block *) (bh->b_data + offset);
5840 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5841 	    !(le32_to_cpu(es->s_feature_incompat) &
5842 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5843 		ext4_msg(sb, KERN_ERR, "external journal has "
5844 					"bad superblock");
5845 		brelse(bh);
5846 		goto out_bdev;
5847 	}
5848 
5849 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5850 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5851 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5852 		ext4_msg(sb, KERN_ERR, "external journal has "
5853 				       "corrupt superblock");
5854 		brelse(bh);
5855 		goto out_bdev;
5856 	}
5857 
5858 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5859 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5860 		brelse(bh);
5861 		goto out_bdev;
5862 	}
5863 
5864 	len = ext4_blocks_count(es);
5865 	start = sb_block + 1;
5866 	brelse(bh);	/* we're done with the superblock */
5867 
5868 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5869 					start, len, blocksize);
5870 	if (!journal) {
5871 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5872 		goto out_bdev;
5873 	}
5874 	journal->j_private = sb;
5875 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5876 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5877 		goto out_journal;
5878 	}
5879 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5880 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5881 					"user (unsupported) - %d",
5882 			be32_to_cpu(journal->j_superblock->s_nr_users));
5883 		goto out_journal;
5884 	}
5885 	EXT4_SB(sb)->s_journal_bdev = bdev;
5886 	ext4_init_journal_params(sb, journal);
5887 	return journal;
5888 
5889 out_journal:
5890 	jbd2_journal_destroy(journal);
5891 out_bdev:
5892 	ext4_blkdev_put(bdev);
5893 	return NULL;
5894 }
5895 
5896 static int ext4_load_journal(struct super_block *sb,
5897 			     struct ext4_super_block *es,
5898 			     unsigned long journal_devnum)
5899 {
5900 	journal_t *journal;
5901 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5902 	dev_t journal_dev;
5903 	int err = 0;
5904 	int really_read_only;
5905 	int journal_dev_ro;
5906 
5907 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5908 		return -EFSCORRUPTED;
5909 
5910 	if (journal_devnum &&
5911 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5912 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5913 			"numbers have changed");
5914 		journal_dev = new_decode_dev(journal_devnum);
5915 	} else
5916 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5917 
5918 	if (journal_inum && journal_dev) {
5919 		ext4_msg(sb, KERN_ERR,
5920 			 "filesystem has both journal inode and journal device!");
5921 		return -EINVAL;
5922 	}
5923 
5924 	if (journal_inum) {
5925 		journal = ext4_get_journal(sb, journal_inum);
5926 		if (!journal)
5927 			return -EINVAL;
5928 	} else {
5929 		journal = ext4_get_dev_journal(sb, journal_dev);
5930 		if (!journal)
5931 			return -EINVAL;
5932 	}
5933 
5934 	journal_dev_ro = bdev_read_only(journal->j_dev);
5935 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5936 
5937 	if (journal_dev_ro && !sb_rdonly(sb)) {
5938 		ext4_msg(sb, KERN_ERR,
5939 			 "journal device read-only, try mounting with '-o ro'");
5940 		err = -EROFS;
5941 		goto err_out;
5942 	}
5943 
5944 	/*
5945 	 * Are we loading a blank journal or performing recovery after a
5946 	 * crash?  For recovery, we need to check in advance whether we
5947 	 * can get read-write access to the device.
5948 	 */
5949 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5950 		if (sb_rdonly(sb)) {
5951 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5952 					"required on readonly filesystem");
5953 			if (really_read_only) {
5954 				ext4_msg(sb, KERN_ERR, "write access "
5955 					"unavailable, cannot proceed "
5956 					"(try mounting with noload)");
5957 				err = -EROFS;
5958 				goto err_out;
5959 			}
5960 			ext4_msg(sb, KERN_INFO, "write access will "
5961 			       "be enabled during recovery");
5962 		}
5963 	}
5964 
5965 	if (!(journal->j_flags & JBD2_BARRIER))
5966 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5967 
5968 	if (!ext4_has_feature_journal_needs_recovery(sb))
5969 		err = jbd2_journal_wipe(journal, !really_read_only);
5970 	if (!err) {
5971 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5972 
5973 		if (save)
5974 			memcpy(save, ((char *) es) +
5975 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5976 		err = jbd2_journal_load(journal);
5977 		if (save)
5978 			memcpy(((char *) es) + EXT4_S_ERR_START,
5979 			       save, EXT4_S_ERR_LEN);
5980 		kfree(save);
5981 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
5982 					   EXT4_ERROR_FS);
5983 		/* Write out restored error information to the superblock */
5984 		if (!bdev_read_only(sb->s_bdev)) {
5985 			int err2;
5986 			err2 = ext4_commit_super(sb);
5987 			err = err ? : err2;
5988 		}
5989 	}
5990 
5991 	if (err) {
5992 		ext4_msg(sb, KERN_ERR, "error loading journal");
5993 		goto err_out;
5994 	}
5995 
5996 	EXT4_SB(sb)->s_journal = journal;
5997 	err = ext4_clear_journal_err(sb, es);
5998 	if (err) {
5999 		EXT4_SB(sb)->s_journal = NULL;
6000 		jbd2_journal_destroy(journal);
6001 		return err;
6002 	}
6003 
6004 	if (!really_read_only && journal_devnum &&
6005 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6006 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6007 		ext4_commit_super(sb);
6008 	}
6009 	if (!really_read_only && journal_inum &&
6010 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6011 		es->s_journal_inum = cpu_to_le32(journal_inum);
6012 		ext4_commit_super(sb);
6013 	}
6014 
6015 	return 0;
6016 
6017 err_out:
6018 	jbd2_journal_destroy(journal);
6019 	return err;
6020 }
6021 
6022 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6023 static void ext4_update_super(struct super_block *sb)
6024 {
6025 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6026 	struct ext4_super_block *es = sbi->s_es;
6027 	struct buffer_head *sbh = sbi->s_sbh;
6028 
6029 	lock_buffer(sbh);
6030 	/*
6031 	 * If the file system is mounted read-only, don't update the
6032 	 * superblock write time.  This avoids updating the superblock
6033 	 * write time when we are mounting the root file system
6034 	 * read/only but we need to replay the journal; at that point,
6035 	 * for people who are east of GMT and who make their clock
6036 	 * tick in localtime for Windows bug-for-bug compatibility,
6037 	 * the clock is set in the future, and this will cause e2fsck
6038 	 * to complain and force a full file system check.
6039 	 */
6040 	if (!(sb->s_flags & SB_RDONLY))
6041 		ext4_update_tstamp(es, s_wtime);
6042 	es->s_kbytes_written =
6043 		cpu_to_le64(sbi->s_kbytes_written +
6044 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6045 		      sbi->s_sectors_written_start) >> 1));
6046 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6047 		ext4_free_blocks_count_set(es,
6048 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6049 				&sbi->s_freeclusters_counter)));
6050 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6051 		es->s_free_inodes_count =
6052 			cpu_to_le32(percpu_counter_sum_positive(
6053 				&sbi->s_freeinodes_counter));
6054 	/* Copy error information to the on-disk superblock */
6055 	spin_lock(&sbi->s_error_lock);
6056 	if (sbi->s_add_error_count > 0) {
6057 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6058 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6059 			__ext4_update_tstamp(&es->s_first_error_time,
6060 					     &es->s_first_error_time_hi,
6061 					     sbi->s_first_error_time);
6062 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6063 				sizeof(es->s_first_error_func));
6064 			es->s_first_error_line =
6065 				cpu_to_le32(sbi->s_first_error_line);
6066 			es->s_first_error_ino =
6067 				cpu_to_le32(sbi->s_first_error_ino);
6068 			es->s_first_error_block =
6069 				cpu_to_le64(sbi->s_first_error_block);
6070 			es->s_first_error_errcode =
6071 				ext4_errno_to_code(sbi->s_first_error_code);
6072 		}
6073 		__ext4_update_tstamp(&es->s_last_error_time,
6074 				     &es->s_last_error_time_hi,
6075 				     sbi->s_last_error_time);
6076 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6077 			sizeof(es->s_last_error_func));
6078 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6079 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6080 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6081 		es->s_last_error_errcode =
6082 				ext4_errno_to_code(sbi->s_last_error_code);
6083 		/*
6084 		 * Start the daily error reporting function if it hasn't been
6085 		 * started already
6086 		 */
6087 		if (!es->s_error_count)
6088 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6089 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6090 		sbi->s_add_error_count = 0;
6091 	}
6092 	spin_unlock(&sbi->s_error_lock);
6093 
6094 	ext4_superblock_csum_set(sb);
6095 	unlock_buffer(sbh);
6096 }
6097 
6098 static int ext4_commit_super(struct super_block *sb)
6099 {
6100 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6101 
6102 	if (!sbh)
6103 		return -EINVAL;
6104 	if (block_device_ejected(sb))
6105 		return -ENODEV;
6106 
6107 	ext4_update_super(sb);
6108 
6109 	lock_buffer(sbh);
6110 	/* Buffer got discarded which means block device got invalidated */
6111 	if (!buffer_mapped(sbh)) {
6112 		unlock_buffer(sbh);
6113 		return -EIO;
6114 	}
6115 
6116 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6117 		/*
6118 		 * Oh, dear.  A previous attempt to write the
6119 		 * superblock failed.  This could happen because the
6120 		 * USB device was yanked out.  Or it could happen to
6121 		 * be a transient write error and maybe the block will
6122 		 * be remapped.  Nothing we can do but to retry the
6123 		 * write and hope for the best.
6124 		 */
6125 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6126 		       "superblock detected");
6127 		clear_buffer_write_io_error(sbh);
6128 		set_buffer_uptodate(sbh);
6129 	}
6130 	get_bh(sbh);
6131 	/* Clear potential dirty bit if it was journalled update */
6132 	clear_buffer_dirty(sbh);
6133 	sbh->b_end_io = end_buffer_write_sync;
6134 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6135 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6136 	wait_on_buffer(sbh);
6137 	if (buffer_write_io_error(sbh)) {
6138 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6139 		       "superblock");
6140 		clear_buffer_write_io_error(sbh);
6141 		set_buffer_uptodate(sbh);
6142 		return -EIO;
6143 	}
6144 	return 0;
6145 }
6146 
6147 /*
6148  * Have we just finished recovery?  If so, and if we are mounting (or
6149  * remounting) the filesystem readonly, then we will end up with a
6150  * consistent fs on disk.  Record that fact.
6151  */
6152 static int ext4_mark_recovery_complete(struct super_block *sb,
6153 				       struct ext4_super_block *es)
6154 {
6155 	int err;
6156 	journal_t *journal = EXT4_SB(sb)->s_journal;
6157 
6158 	if (!ext4_has_feature_journal(sb)) {
6159 		if (journal != NULL) {
6160 			ext4_error(sb, "Journal got removed while the fs was "
6161 				   "mounted!");
6162 			return -EFSCORRUPTED;
6163 		}
6164 		return 0;
6165 	}
6166 	jbd2_journal_lock_updates(journal);
6167 	err = jbd2_journal_flush(journal, 0);
6168 	if (err < 0)
6169 		goto out;
6170 
6171 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6172 	    ext4_has_feature_orphan_present(sb))) {
6173 		if (!ext4_orphan_file_empty(sb)) {
6174 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6175 			err = -EFSCORRUPTED;
6176 			goto out;
6177 		}
6178 		ext4_clear_feature_journal_needs_recovery(sb);
6179 		ext4_clear_feature_orphan_present(sb);
6180 		ext4_commit_super(sb);
6181 	}
6182 out:
6183 	jbd2_journal_unlock_updates(journal);
6184 	return err;
6185 }
6186 
6187 /*
6188  * If we are mounting (or read-write remounting) a filesystem whose journal
6189  * has recorded an error from a previous lifetime, move that error to the
6190  * main filesystem now.
6191  */
6192 static int ext4_clear_journal_err(struct super_block *sb,
6193 				   struct ext4_super_block *es)
6194 {
6195 	journal_t *journal;
6196 	int j_errno;
6197 	const char *errstr;
6198 
6199 	if (!ext4_has_feature_journal(sb)) {
6200 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6201 		return -EFSCORRUPTED;
6202 	}
6203 
6204 	journal = EXT4_SB(sb)->s_journal;
6205 
6206 	/*
6207 	 * Now check for any error status which may have been recorded in the
6208 	 * journal by a prior ext4_error() or ext4_abort()
6209 	 */
6210 
6211 	j_errno = jbd2_journal_errno(journal);
6212 	if (j_errno) {
6213 		char nbuf[16];
6214 
6215 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6216 		ext4_warning(sb, "Filesystem error recorded "
6217 			     "from previous mount: %s", errstr);
6218 
6219 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6220 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6221 		j_errno = ext4_commit_super(sb);
6222 		if (j_errno)
6223 			return j_errno;
6224 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6225 
6226 		jbd2_journal_clear_err(journal);
6227 		jbd2_journal_update_sb_errno(journal);
6228 	}
6229 	return 0;
6230 }
6231 
6232 /*
6233  * Force the running and committing transactions to commit,
6234  * and wait on the commit.
6235  */
6236 int ext4_force_commit(struct super_block *sb)
6237 {
6238 	journal_t *journal;
6239 
6240 	if (sb_rdonly(sb))
6241 		return 0;
6242 
6243 	journal = EXT4_SB(sb)->s_journal;
6244 	return ext4_journal_force_commit(journal);
6245 }
6246 
6247 static int ext4_sync_fs(struct super_block *sb, int wait)
6248 {
6249 	int ret = 0;
6250 	tid_t target;
6251 	bool needs_barrier = false;
6252 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6253 
6254 	if (unlikely(ext4_forced_shutdown(sbi)))
6255 		return 0;
6256 
6257 	trace_ext4_sync_fs(sb, wait);
6258 	flush_workqueue(sbi->rsv_conversion_wq);
6259 	/*
6260 	 * Writeback quota in non-journalled quota case - journalled quota has
6261 	 * no dirty dquots
6262 	 */
6263 	dquot_writeback_dquots(sb, -1);
6264 	/*
6265 	 * Data writeback is possible w/o journal transaction, so barrier must
6266 	 * being sent at the end of the function. But we can skip it if
6267 	 * transaction_commit will do it for us.
6268 	 */
6269 	if (sbi->s_journal) {
6270 		target = jbd2_get_latest_transaction(sbi->s_journal);
6271 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6272 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6273 			needs_barrier = true;
6274 
6275 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6276 			if (wait)
6277 				ret = jbd2_log_wait_commit(sbi->s_journal,
6278 							   target);
6279 		}
6280 	} else if (wait && test_opt(sb, BARRIER))
6281 		needs_barrier = true;
6282 	if (needs_barrier) {
6283 		int err;
6284 		err = blkdev_issue_flush(sb->s_bdev);
6285 		if (!ret)
6286 			ret = err;
6287 	}
6288 
6289 	return ret;
6290 }
6291 
6292 /*
6293  * LVM calls this function before a (read-only) snapshot is created.  This
6294  * gives us a chance to flush the journal completely and mark the fs clean.
6295  *
6296  * Note that only this function cannot bring a filesystem to be in a clean
6297  * state independently. It relies on upper layer to stop all data & metadata
6298  * modifications.
6299  */
6300 static int ext4_freeze(struct super_block *sb)
6301 {
6302 	int error = 0;
6303 	journal_t *journal;
6304 
6305 	if (sb_rdonly(sb))
6306 		return 0;
6307 
6308 	journal = EXT4_SB(sb)->s_journal;
6309 
6310 	if (journal) {
6311 		/* Now we set up the journal barrier. */
6312 		jbd2_journal_lock_updates(journal);
6313 
6314 		/*
6315 		 * Don't clear the needs_recovery flag if we failed to
6316 		 * flush the journal.
6317 		 */
6318 		error = jbd2_journal_flush(journal, 0);
6319 		if (error < 0)
6320 			goto out;
6321 
6322 		/* Journal blocked and flushed, clear needs_recovery flag. */
6323 		ext4_clear_feature_journal_needs_recovery(sb);
6324 		if (ext4_orphan_file_empty(sb))
6325 			ext4_clear_feature_orphan_present(sb);
6326 	}
6327 
6328 	error = ext4_commit_super(sb);
6329 out:
6330 	if (journal)
6331 		/* we rely on upper layer to stop further updates */
6332 		jbd2_journal_unlock_updates(journal);
6333 	return error;
6334 }
6335 
6336 /*
6337  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6338  * flag here, even though the filesystem is not technically dirty yet.
6339  */
6340 static int ext4_unfreeze(struct super_block *sb)
6341 {
6342 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6343 		return 0;
6344 
6345 	if (EXT4_SB(sb)->s_journal) {
6346 		/* Reset the needs_recovery flag before the fs is unlocked. */
6347 		ext4_set_feature_journal_needs_recovery(sb);
6348 		if (ext4_has_feature_orphan_file(sb))
6349 			ext4_set_feature_orphan_present(sb);
6350 	}
6351 
6352 	ext4_commit_super(sb);
6353 	return 0;
6354 }
6355 
6356 /*
6357  * Structure to save mount options for ext4_remount's benefit
6358  */
6359 struct ext4_mount_options {
6360 	unsigned long s_mount_opt;
6361 	unsigned long s_mount_opt2;
6362 	kuid_t s_resuid;
6363 	kgid_t s_resgid;
6364 	unsigned long s_commit_interval;
6365 	u32 s_min_batch_time, s_max_batch_time;
6366 #ifdef CONFIG_QUOTA
6367 	int s_jquota_fmt;
6368 	char *s_qf_names[EXT4_MAXQUOTAS];
6369 #endif
6370 };
6371 
6372 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6373 {
6374 	struct ext4_fs_context *ctx = fc->fs_private;
6375 	struct ext4_super_block *es;
6376 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6377 	unsigned long old_sb_flags;
6378 	struct ext4_mount_options old_opts;
6379 	ext4_group_t g;
6380 	int err = 0;
6381 #ifdef CONFIG_QUOTA
6382 	int enable_quota = 0;
6383 	int i, j;
6384 	char *to_free[EXT4_MAXQUOTAS];
6385 #endif
6386 
6387 
6388 	/* Store the original options */
6389 	old_sb_flags = sb->s_flags;
6390 	old_opts.s_mount_opt = sbi->s_mount_opt;
6391 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6392 	old_opts.s_resuid = sbi->s_resuid;
6393 	old_opts.s_resgid = sbi->s_resgid;
6394 	old_opts.s_commit_interval = sbi->s_commit_interval;
6395 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6396 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6397 #ifdef CONFIG_QUOTA
6398 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6399 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6400 		if (sbi->s_qf_names[i]) {
6401 			char *qf_name = get_qf_name(sb, sbi, i);
6402 
6403 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6404 			if (!old_opts.s_qf_names[i]) {
6405 				for (j = 0; j < i; j++)
6406 					kfree(old_opts.s_qf_names[j]);
6407 				return -ENOMEM;
6408 			}
6409 		} else
6410 			old_opts.s_qf_names[i] = NULL;
6411 #endif
6412 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6413 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6414 			ctx->journal_ioprio =
6415 				sbi->s_journal->j_task->io_context->ioprio;
6416 		else
6417 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6418 
6419 	}
6420 
6421 	ext4_apply_options(fc, sb);
6422 
6423 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6424 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6425 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6426 			 "during remount not supported; ignoring");
6427 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6428 	}
6429 
6430 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6431 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6432 			ext4_msg(sb, KERN_ERR, "can't mount with "
6433 				 "both data=journal and delalloc");
6434 			err = -EINVAL;
6435 			goto restore_opts;
6436 		}
6437 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6438 			ext4_msg(sb, KERN_ERR, "can't mount with "
6439 				 "both data=journal and dioread_nolock");
6440 			err = -EINVAL;
6441 			goto restore_opts;
6442 		}
6443 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6444 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6445 			ext4_msg(sb, KERN_ERR, "can't mount with "
6446 				"journal_async_commit in data=ordered mode");
6447 			err = -EINVAL;
6448 			goto restore_opts;
6449 		}
6450 	}
6451 
6452 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6453 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6454 		err = -EINVAL;
6455 		goto restore_opts;
6456 	}
6457 
6458 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6459 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6460 
6461 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6462 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6463 
6464 	es = sbi->s_es;
6465 
6466 	if (sbi->s_journal) {
6467 		ext4_init_journal_params(sb, sbi->s_journal);
6468 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6469 	}
6470 
6471 	/* Flush outstanding errors before changing fs state */
6472 	flush_work(&sbi->s_error_work);
6473 
6474 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6475 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6476 			err = -EROFS;
6477 			goto restore_opts;
6478 		}
6479 
6480 		if (fc->sb_flags & SB_RDONLY) {
6481 			err = sync_filesystem(sb);
6482 			if (err < 0)
6483 				goto restore_opts;
6484 			err = dquot_suspend(sb, -1);
6485 			if (err < 0)
6486 				goto restore_opts;
6487 
6488 			/*
6489 			 * First of all, the unconditional stuff we have to do
6490 			 * to disable replay of the journal when we next remount
6491 			 */
6492 			sb->s_flags |= SB_RDONLY;
6493 
6494 			/*
6495 			 * OK, test if we are remounting a valid rw partition
6496 			 * readonly, and if so set the rdonly flag and then
6497 			 * mark the partition as valid again.
6498 			 */
6499 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6500 			    (sbi->s_mount_state & EXT4_VALID_FS))
6501 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6502 
6503 			if (sbi->s_journal) {
6504 				/*
6505 				 * We let remount-ro finish even if marking fs
6506 				 * as clean failed...
6507 				 */
6508 				ext4_mark_recovery_complete(sb, es);
6509 			}
6510 		} else {
6511 			/* Make sure we can mount this feature set readwrite */
6512 			if (ext4_has_feature_readonly(sb) ||
6513 			    !ext4_feature_set_ok(sb, 0)) {
6514 				err = -EROFS;
6515 				goto restore_opts;
6516 			}
6517 			/*
6518 			 * Make sure the group descriptor checksums
6519 			 * are sane.  If they aren't, refuse to remount r/w.
6520 			 */
6521 			for (g = 0; g < sbi->s_groups_count; g++) {
6522 				struct ext4_group_desc *gdp =
6523 					ext4_get_group_desc(sb, g, NULL);
6524 
6525 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6526 					ext4_msg(sb, KERN_ERR,
6527 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6528 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6529 					       le16_to_cpu(gdp->bg_checksum));
6530 					err = -EFSBADCRC;
6531 					goto restore_opts;
6532 				}
6533 			}
6534 
6535 			/*
6536 			 * If we have an unprocessed orphan list hanging
6537 			 * around from a previously readonly bdev mount,
6538 			 * require a full umount/remount for now.
6539 			 */
6540 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6541 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6542 				       "remount RDWR because of unprocessed "
6543 				       "orphan inode list.  Please "
6544 				       "umount/remount instead");
6545 				err = -EINVAL;
6546 				goto restore_opts;
6547 			}
6548 
6549 			/*
6550 			 * Mounting a RDONLY partition read-write, so reread
6551 			 * and store the current valid flag.  (It may have
6552 			 * been changed by e2fsck since we originally mounted
6553 			 * the partition.)
6554 			 */
6555 			if (sbi->s_journal) {
6556 				err = ext4_clear_journal_err(sb, es);
6557 				if (err)
6558 					goto restore_opts;
6559 			}
6560 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6561 					      ~EXT4_FC_REPLAY);
6562 
6563 			err = ext4_setup_super(sb, es, 0);
6564 			if (err)
6565 				goto restore_opts;
6566 
6567 			sb->s_flags &= ~SB_RDONLY;
6568 			if (ext4_has_feature_mmp(sb))
6569 				if (ext4_multi_mount_protect(sb,
6570 						le64_to_cpu(es->s_mmp_block))) {
6571 					err = -EROFS;
6572 					goto restore_opts;
6573 				}
6574 #ifdef CONFIG_QUOTA
6575 			enable_quota = 1;
6576 #endif
6577 		}
6578 	}
6579 
6580 	/*
6581 	 * Reinitialize lazy itable initialization thread based on
6582 	 * current settings
6583 	 */
6584 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6585 		ext4_unregister_li_request(sb);
6586 	else {
6587 		ext4_group_t first_not_zeroed;
6588 		first_not_zeroed = ext4_has_uninit_itable(sb);
6589 		ext4_register_li_request(sb, first_not_zeroed);
6590 	}
6591 
6592 	/*
6593 	 * Handle creation of system zone data early because it can fail.
6594 	 * Releasing of existing data is done when we are sure remount will
6595 	 * succeed.
6596 	 */
6597 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6598 		err = ext4_setup_system_zone(sb);
6599 		if (err)
6600 			goto restore_opts;
6601 	}
6602 
6603 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6604 		err = ext4_commit_super(sb);
6605 		if (err)
6606 			goto restore_opts;
6607 	}
6608 
6609 #ifdef CONFIG_QUOTA
6610 	/* Release old quota file names */
6611 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6612 		kfree(old_opts.s_qf_names[i]);
6613 	if (enable_quota) {
6614 		if (sb_any_quota_suspended(sb))
6615 			dquot_resume(sb, -1);
6616 		else if (ext4_has_feature_quota(sb)) {
6617 			err = ext4_enable_quotas(sb);
6618 			if (err)
6619 				goto restore_opts;
6620 		}
6621 	}
6622 #endif
6623 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6624 		ext4_release_system_zone(sb);
6625 
6626 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6627 		ext4_stop_mmpd(sbi);
6628 
6629 	return 0;
6630 
6631 restore_opts:
6632 	sb->s_flags = old_sb_flags;
6633 	sbi->s_mount_opt = old_opts.s_mount_opt;
6634 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6635 	sbi->s_resuid = old_opts.s_resuid;
6636 	sbi->s_resgid = old_opts.s_resgid;
6637 	sbi->s_commit_interval = old_opts.s_commit_interval;
6638 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6639 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6640 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6641 		ext4_release_system_zone(sb);
6642 #ifdef CONFIG_QUOTA
6643 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6644 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6645 		to_free[i] = get_qf_name(sb, sbi, i);
6646 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6647 	}
6648 	synchronize_rcu();
6649 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6650 		kfree(to_free[i]);
6651 #endif
6652 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6653 		ext4_stop_mmpd(sbi);
6654 	return err;
6655 }
6656 
6657 static int ext4_reconfigure(struct fs_context *fc)
6658 {
6659 	struct super_block *sb = fc->root->d_sb;
6660 	int ret;
6661 
6662 	fc->s_fs_info = EXT4_SB(sb);
6663 
6664 	ret = ext4_check_opt_consistency(fc, sb);
6665 	if (ret < 0)
6666 		return ret;
6667 
6668 	ret = __ext4_remount(fc, sb);
6669 	if (ret < 0)
6670 		return ret;
6671 
6672 	ext4_msg(sb, KERN_INFO, "re-mounted %pU. Quota mode: %s.",
6673 		 &sb->s_uuid, ext4_quota_mode(sb));
6674 
6675 	return 0;
6676 }
6677 
6678 #ifdef CONFIG_QUOTA
6679 static int ext4_statfs_project(struct super_block *sb,
6680 			       kprojid_t projid, struct kstatfs *buf)
6681 {
6682 	struct kqid qid;
6683 	struct dquot *dquot;
6684 	u64 limit;
6685 	u64 curblock;
6686 
6687 	qid = make_kqid_projid(projid);
6688 	dquot = dqget(sb, qid);
6689 	if (IS_ERR(dquot))
6690 		return PTR_ERR(dquot);
6691 	spin_lock(&dquot->dq_dqb_lock);
6692 
6693 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6694 			     dquot->dq_dqb.dqb_bhardlimit);
6695 	limit >>= sb->s_blocksize_bits;
6696 
6697 	if (limit && buf->f_blocks > limit) {
6698 		curblock = (dquot->dq_dqb.dqb_curspace +
6699 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6700 		buf->f_blocks = limit;
6701 		buf->f_bfree = buf->f_bavail =
6702 			(buf->f_blocks > curblock) ?
6703 			 (buf->f_blocks - curblock) : 0;
6704 	}
6705 
6706 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6707 			     dquot->dq_dqb.dqb_ihardlimit);
6708 	if (limit && buf->f_files > limit) {
6709 		buf->f_files = limit;
6710 		buf->f_ffree =
6711 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6712 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6713 	}
6714 
6715 	spin_unlock(&dquot->dq_dqb_lock);
6716 	dqput(dquot);
6717 	return 0;
6718 }
6719 #endif
6720 
6721 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6722 {
6723 	struct super_block *sb = dentry->d_sb;
6724 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6725 	struct ext4_super_block *es = sbi->s_es;
6726 	ext4_fsblk_t overhead = 0, resv_blocks;
6727 	s64 bfree;
6728 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6729 
6730 	if (!test_opt(sb, MINIX_DF))
6731 		overhead = sbi->s_overhead;
6732 
6733 	buf->f_type = EXT4_SUPER_MAGIC;
6734 	buf->f_bsize = sb->s_blocksize;
6735 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6736 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6737 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6738 	/* prevent underflow in case that few free space is available */
6739 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6740 	buf->f_bavail = buf->f_bfree -
6741 			(ext4_r_blocks_count(es) + resv_blocks);
6742 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6743 		buf->f_bavail = 0;
6744 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6745 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6746 	buf->f_namelen = EXT4_NAME_LEN;
6747 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6748 
6749 #ifdef CONFIG_QUOTA
6750 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6751 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6752 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6753 #endif
6754 	return 0;
6755 }
6756 
6757 
6758 #ifdef CONFIG_QUOTA
6759 
6760 /*
6761  * Helper functions so that transaction is started before we acquire dqio_sem
6762  * to keep correct lock ordering of transaction > dqio_sem
6763  */
6764 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6765 {
6766 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6767 }
6768 
6769 static int ext4_write_dquot(struct dquot *dquot)
6770 {
6771 	int ret, err;
6772 	handle_t *handle;
6773 	struct inode *inode;
6774 
6775 	inode = dquot_to_inode(dquot);
6776 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6777 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6778 	if (IS_ERR(handle))
6779 		return PTR_ERR(handle);
6780 	ret = dquot_commit(dquot);
6781 	err = ext4_journal_stop(handle);
6782 	if (!ret)
6783 		ret = err;
6784 	return ret;
6785 }
6786 
6787 static int ext4_acquire_dquot(struct dquot *dquot)
6788 {
6789 	int ret, err;
6790 	handle_t *handle;
6791 
6792 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6793 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6794 	if (IS_ERR(handle))
6795 		return PTR_ERR(handle);
6796 	ret = dquot_acquire(dquot);
6797 	err = ext4_journal_stop(handle);
6798 	if (!ret)
6799 		ret = err;
6800 	return ret;
6801 }
6802 
6803 static int ext4_release_dquot(struct dquot *dquot)
6804 {
6805 	int ret, err;
6806 	handle_t *handle;
6807 
6808 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6809 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6810 	if (IS_ERR(handle)) {
6811 		/* Release dquot anyway to avoid endless cycle in dqput() */
6812 		dquot_release(dquot);
6813 		return PTR_ERR(handle);
6814 	}
6815 	ret = dquot_release(dquot);
6816 	err = ext4_journal_stop(handle);
6817 	if (!ret)
6818 		ret = err;
6819 	return ret;
6820 }
6821 
6822 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6823 {
6824 	struct super_block *sb = dquot->dq_sb;
6825 
6826 	if (ext4_is_quota_journalled(sb)) {
6827 		dquot_mark_dquot_dirty(dquot);
6828 		return ext4_write_dquot(dquot);
6829 	} else {
6830 		return dquot_mark_dquot_dirty(dquot);
6831 	}
6832 }
6833 
6834 static int ext4_write_info(struct super_block *sb, int type)
6835 {
6836 	int ret, err;
6837 	handle_t *handle;
6838 
6839 	/* Data block + inode block */
6840 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6841 	if (IS_ERR(handle))
6842 		return PTR_ERR(handle);
6843 	ret = dquot_commit_info(sb, type);
6844 	err = ext4_journal_stop(handle);
6845 	if (!ret)
6846 		ret = err;
6847 	return ret;
6848 }
6849 
6850 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6851 {
6852 	struct ext4_inode_info *ei = EXT4_I(inode);
6853 
6854 	/* The first argument of lockdep_set_subclass has to be
6855 	 * *exactly* the same as the argument to init_rwsem() --- in
6856 	 * this case, in init_once() --- or lockdep gets unhappy
6857 	 * because the name of the lock is set using the
6858 	 * stringification of the argument to init_rwsem().
6859 	 */
6860 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6861 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6862 }
6863 
6864 /*
6865  * Standard function to be called on quota_on
6866  */
6867 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6868 			 const struct path *path)
6869 {
6870 	int err;
6871 
6872 	if (!test_opt(sb, QUOTA))
6873 		return -EINVAL;
6874 
6875 	/* Quotafile not on the same filesystem? */
6876 	if (path->dentry->d_sb != sb)
6877 		return -EXDEV;
6878 
6879 	/* Quota already enabled for this file? */
6880 	if (IS_NOQUOTA(d_inode(path->dentry)))
6881 		return -EBUSY;
6882 
6883 	/* Journaling quota? */
6884 	if (EXT4_SB(sb)->s_qf_names[type]) {
6885 		/* Quotafile not in fs root? */
6886 		if (path->dentry->d_parent != sb->s_root)
6887 			ext4_msg(sb, KERN_WARNING,
6888 				"Quota file not on filesystem root. "
6889 				"Journaled quota will not work");
6890 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6891 	} else {
6892 		/*
6893 		 * Clear the flag just in case mount options changed since
6894 		 * last time.
6895 		 */
6896 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6897 	}
6898 
6899 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6900 	err = dquot_quota_on(sb, type, format_id, path);
6901 	if (!err) {
6902 		struct inode *inode = d_inode(path->dentry);
6903 		handle_t *handle;
6904 
6905 		/*
6906 		 * Set inode flags to prevent userspace from messing with quota
6907 		 * files. If this fails, we return success anyway since quotas
6908 		 * are already enabled and this is not a hard failure.
6909 		 */
6910 		inode_lock(inode);
6911 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6912 		if (IS_ERR(handle))
6913 			goto unlock_inode;
6914 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6915 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6916 				S_NOATIME | S_IMMUTABLE);
6917 		err = ext4_mark_inode_dirty(handle, inode);
6918 		ext4_journal_stop(handle);
6919 	unlock_inode:
6920 		inode_unlock(inode);
6921 		if (err)
6922 			dquot_quota_off(sb, type);
6923 	}
6924 	if (err)
6925 		lockdep_set_quota_inode(path->dentry->d_inode,
6926 					     I_DATA_SEM_NORMAL);
6927 	return err;
6928 }
6929 
6930 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
6931 {
6932 	switch (type) {
6933 	case USRQUOTA:
6934 		return qf_inum == EXT4_USR_QUOTA_INO;
6935 	case GRPQUOTA:
6936 		return qf_inum == EXT4_GRP_QUOTA_INO;
6937 	case PRJQUOTA:
6938 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
6939 	default:
6940 		BUG();
6941 	}
6942 }
6943 
6944 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6945 			     unsigned int flags)
6946 {
6947 	int err;
6948 	struct inode *qf_inode;
6949 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6950 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6951 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6952 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6953 	};
6954 
6955 	BUG_ON(!ext4_has_feature_quota(sb));
6956 
6957 	if (!qf_inums[type])
6958 		return -EPERM;
6959 
6960 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
6961 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
6962 				qf_inums[type], type);
6963 		return -EUCLEAN;
6964 	}
6965 
6966 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6967 	if (IS_ERR(qf_inode)) {
6968 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
6969 				qf_inums[type], type);
6970 		return PTR_ERR(qf_inode);
6971 	}
6972 
6973 	/* Don't account quota for quota files to avoid recursion */
6974 	qf_inode->i_flags |= S_NOQUOTA;
6975 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6976 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6977 	if (err)
6978 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6979 	iput(qf_inode);
6980 
6981 	return err;
6982 }
6983 
6984 /* Enable usage tracking for all quota types. */
6985 int ext4_enable_quotas(struct super_block *sb)
6986 {
6987 	int type, err = 0;
6988 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6989 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6990 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6991 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6992 	};
6993 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6994 		test_opt(sb, USRQUOTA),
6995 		test_opt(sb, GRPQUOTA),
6996 		test_opt(sb, PRJQUOTA),
6997 	};
6998 
6999 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7000 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7001 		if (qf_inums[type]) {
7002 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7003 				DQUOT_USAGE_ENABLED |
7004 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7005 			if (err) {
7006 				ext4_warning(sb,
7007 					"Failed to enable quota tracking "
7008 					"(type=%d, err=%d, ino=%lu). "
7009 					"Please run e2fsck to fix.", type,
7010 					err, qf_inums[type]);
7011 				for (type--; type >= 0; type--) {
7012 					struct inode *inode;
7013 
7014 					inode = sb_dqopt(sb)->files[type];
7015 					if (inode)
7016 						inode = igrab(inode);
7017 					dquot_quota_off(sb, type);
7018 					if (inode) {
7019 						lockdep_set_quota_inode(inode,
7020 							I_DATA_SEM_NORMAL);
7021 						iput(inode);
7022 					}
7023 				}
7024 
7025 				return err;
7026 			}
7027 		}
7028 	}
7029 	return 0;
7030 }
7031 
7032 static int ext4_quota_off(struct super_block *sb, int type)
7033 {
7034 	struct inode *inode = sb_dqopt(sb)->files[type];
7035 	handle_t *handle;
7036 	int err;
7037 
7038 	/* Force all delayed allocation blocks to be allocated.
7039 	 * Caller already holds s_umount sem */
7040 	if (test_opt(sb, DELALLOC))
7041 		sync_filesystem(sb);
7042 
7043 	if (!inode || !igrab(inode))
7044 		goto out;
7045 
7046 	err = dquot_quota_off(sb, type);
7047 	if (err || ext4_has_feature_quota(sb))
7048 		goto out_put;
7049 
7050 	inode_lock(inode);
7051 	/*
7052 	 * Update modification times of quota files when userspace can
7053 	 * start looking at them. If we fail, we return success anyway since
7054 	 * this is not a hard failure and quotas are already disabled.
7055 	 */
7056 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7057 	if (IS_ERR(handle)) {
7058 		err = PTR_ERR(handle);
7059 		goto out_unlock;
7060 	}
7061 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7062 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7063 	inode->i_mtime = inode->i_ctime = current_time(inode);
7064 	err = ext4_mark_inode_dirty(handle, inode);
7065 	ext4_journal_stop(handle);
7066 out_unlock:
7067 	inode_unlock(inode);
7068 out_put:
7069 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7070 	iput(inode);
7071 	return err;
7072 out:
7073 	return dquot_quota_off(sb, type);
7074 }
7075 
7076 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7077  * acquiring the locks... As quota files are never truncated and quota code
7078  * itself serializes the operations (and no one else should touch the files)
7079  * we don't have to be afraid of races */
7080 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7081 			       size_t len, loff_t off)
7082 {
7083 	struct inode *inode = sb_dqopt(sb)->files[type];
7084 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7085 	int offset = off & (sb->s_blocksize - 1);
7086 	int tocopy;
7087 	size_t toread;
7088 	struct buffer_head *bh;
7089 	loff_t i_size = i_size_read(inode);
7090 
7091 	if (off > i_size)
7092 		return 0;
7093 	if (off+len > i_size)
7094 		len = i_size-off;
7095 	toread = len;
7096 	while (toread > 0) {
7097 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7098 		bh = ext4_bread(NULL, inode, blk, 0);
7099 		if (IS_ERR(bh))
7100 			return PTR_ERR(bh);
7101 		if (!bh)	/* A hole? */
7102 			memset(data, 0, tocopy);
7103 		else
7104 			memcpy(data, bh->b_data+offset, tocopy);
7105 		brelse(bh);
7106 		offset = 0;
7107 		toread -= tocopy;
7108 		data += tocopy;
7109 		blk++;
7110 	}
7111 	return len;
7112 }
7113 
7114 /* Write to quotafile (we know the transaction is already started and has
7115  * enough credits) */
7116 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7117 				const char *data, size_t len, loff_t off)
7118 {
7119 	struct inode *inode = sb_dqopt(sb)->files[type];
7120 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7121 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7122 	int retries = 0;
7123 	struct buffer_head *bh;
7124 	handle_t *handle = journal_current_handle();
7125 
7126 	if (!handle) {
7127 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7128 			" cancelled because transaction is not started",
7129 			(unsigned long long)off, (unsigned long long)len);
7130 		return -EIO;
7131 	}
7132 	/*
7133 	 * Since we account only one data block in transaction credits,
7134 	 * then it is impossible to cross a block boundary.
7135 	 */
7136 	if (sb->s_blocksize - offset < len) {
7137 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7138 			" cancelled because not block aligned",
7139 			(unsigned long long)off, (unsigned long long)len);
7140 		return -EIO;
7141 	}
7142 
7143 	do {
7144 		bh = ext4_bread(handle, inode, blk,
7145 				EXT4_GET_BLOCKS_CREATE |
7146 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7147 	} while (PTR_ERR(bh) == -ENOSPC &&
7148 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7149 	if (IS_ERR(bh))
7150 		return PTR_ERR(bh);
7151 	if (!bh)
7152 		goto out;
7153 	BUFFER_TRACE(bh, "get write access");
7154 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7155 	if (err) {
7156 		brelse(bh);
7157 		return err;
7158 	}
7159 	lock_buffer(bh);
7160 	memcpy(bh->b_data+offset, data, len);
7161 	flush_dcache_page(bh->b_page);
7162 	unlock_buffer(bh);
7163 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7164 	brelse(bh);
7165 out:
7166 	if (inode->i_size < off + len) {
7167 		i_size_write(inode, off + len);
7168 		EXT4_I(inode)->i_disksize = inode->i_size;
7169 		err2 = ext4_mark_inode_dirty(handle, inode);
7170 		if (unlikely(err2 && !err))
7171 			err = err2;
7172 	}
7173 	return err ? err : len;
7174 }
7175 #endif
7176 
7177 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7178 static inline void register_as_ext2(void)
7179 {
7180 	int err = register_filesystem(&ext2_fs_type);
7181 	if (err)
7182 		printk(KERN_WARNING
7183 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7184 }
7185 
7186 static inline void unregister_as_ext2(void)
7187 {
7188 	unregister_filesystem(&ext2_fs_type);
7189 }
7190 
7191 static inline int ext2_feature_set_ok(struct super_block *sb)
7192 {
7193 	if (ext4_has_unknown_ext2_incompat_features(sb))
7194 		return 0;
7195 	if (sb_rdonly(sb))
7196 		return 1;
7197 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7198 		return 0;
7199 	return 1;
7200 }
7201 #else
7202 static inline void register_as_ext2(void) { }
7203 static inline void unregister_as_ext2(void) { }
7204 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7205 #endif
7206 
7207 static inline void register_as_ext3(void)
7208 {
7209 	int err = register_filesystem(&ext3_fs_type);
7210 	if (err)
7211 		printk(KERN_WARNING
7212 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7213 }
7214 
7215 static inline void unregister_as_ext3(void)
7216 {
7217 	unregister_filesystem(&ext3_fs_type);
7218 }
7219 
7220 static inline int ext3_feature_set_ok(struct super_block *sb)
7221 {
7222 	if (ext4_has_unknown_ext3_incompat_features(sb))
7223 		return 0;
7224 	if (!ext4_has_feature_journal(sb))
7225 		return 0;
7226 	if (sb_rdonly(sb))
7227 		return 1;
7228 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7229 		return 0;
7230 	return 1;
7231 }
7232 
7233 static struct file_system_type ext4_fs_type = {
7234 	.owner			= THIS_MODULE,
7235 	.name			= "ext4",
7236 	.init_fs_context	= ext4_init_fs_context,
7237 	.parameters		= ext4_param_specs,
7238 	.kill_sb		= kill_block_super,
7239 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7240 };
7241 MODULE_ALIAS_FS("ext4");
7242 
7243 /* Shared across all ext4 file systems */
7244 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7245 
7246 static int __init ext4_init_fs(void)
7247 {
7248 	int i, err;
7249 
7250 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7251 	ext4_li_info = NULL;
7252 
7253 	/* Build-time check for flags consistency */
7254 	ext4_check_flag_values();
7255 
7256 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7257 		init_waitqueue_head(&ext4__ioend_wq[i]);
7258 
7259 	err = ext4_init_es();
7260 	if (err)
7261 		return err;
7262 
7263 	err = ext4_init_pending();
7264 	if (err)
7265 		goto out7;
7266 
7267 	err = ext4_init_post_read_processing();
7268 	if (err)
7269 		goto out6;
7270 
7271 	err = ext4_init_pageio();
7272 	if (err)
7273 		goto out5;
7274 
7275 	err = ext4_init_system_zone();
7276 	if (err)
7277 		goto out4;
7278 
7279 	err = ext4_init_sysfs();
7280 	if (err)
7281 		goto out3;
7282 
7283 	err = ext4_init_mballoc();
7284 	if (err)
7285 		goto out2;
7286 	err = init_inodecache();
7287 	if (err)
7288 		goto out1;
7289 
7290 	err = ext4_fc_init_dentry_cache();
7291 	if (err)
7292 		goto out05;
7293 
7294 	register_as_ext3();
7295 	register_as_ext2();
7296 	err = register_filesystem(&ext4_fs_type);
7297 	if (err)
7298 		goto out;
7299 
7300 	return 0;
7301 out:
7302 	unregister_as_ext2();
7303 	unregister_as_ext3();
7304 	ext4_fc_destroy_dentry_cache();
7305 out05:
7306 	destroy_inodecache();
7307 out1:
7308 	ext4_exit_mballoc();
7309 out2:
7310 	ext4_exit_sysfs();
7311 out3:
7312 	ext4_exit_system_zone();
7313 out4:
7314 	ext4_exit_pageio();
7315 out5:
7316 	ext4_exit_post_read_processing();
7317 out6:
7318 	ext4_exit_pending();
7319 out7:
7320 	ext4_exit_es();
7321 
7322 	return err;
7323 }
7324 
7325 static void __exit ext4_exit_fs(void)
7326 {
7327 	ext4_destroy_lazyinit_thread();
7328 	unregister_as_ext2();
7329 	unregister_as_ext3();
7330 	unregister_filesystem(&ext4_fs_type);
7331 	ext4_fc_destroy_dentry_cache();
7332 	destroy_inodecache();
7333 	ext4_exit_mballoc();
7334 	ext4_exit_sysfs();
7335 	ext4_exit_system_zone();
7336 	ext4_exit_pageio();
7337 	ext4_exit_post_read_processing();
7338 	ext4_exit_es();
7339 	ext4_exit_pending();
7340 }
7341 
7342 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7343 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7344 MODULE_LICENSE("GPL");
7345 MODULE_SOFTDEP("pre: crc32c");
7346 module_init(ext4_init_fs)
7347 module_exit(ext4_exit_fs)
7348