xref: /linux/fs/ext4/super.c (revision cbafa54aa2ae23939846e150ad4ba98c784f6395)
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/cleancache.h>
43 #include <linux/uaccess.h>
44 #include <linux/iversion.h>
45 #include <linux/unicode.h>
46 #include <linux/part_stat.h>
47 #include <linux/kthread.h>
48 #include <linux/freezer.h>
49 
50 #include "ext4.h"
51 #include "ext4_extents.h"	/* Needed for trace points definition */
52 #include "ext4_jbd2.h"
53 #include "xattr.h"
54 #include "acl.h"
55 #include "mballoc.h"
56 #include "fsmap.h"
57 
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/ext4.h>
60 
61 static struct ext4_lazy_init *ext4_li_info;
62 static DEFINE_MUTEX(ext4_li_mtx);
63 static struct ratelimit_state ext4_mount_msg_ratelimit;
64 
65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
66 			     unsigned long journal_devnum);
67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
68 static void ext4_update_super(struct super_block *sb);
69 static int ext4_commit_super(struct super_block *sb);
70 static int ext4_mark_recovery_complete(struct super_block *sb,
71 					struct ext4_super_block *es);
72 static int ext4_clear_journal_err(struct super_block *sb,
73 				  struct ext4_super_block *es);
74 static int ext4_sync_fs(struct super_block *sb, int wait);
75 static int ext4_remount(struct super_block *sb, int *flags, char *data);
76 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
77 static int ext4_unfreeze(struct super_block *sb);
78 static int ext4_freeze(struct super_block *sb);
79 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
80 		       const char *dev_name, void *data);
81 static inline int ext2_feature_set_ok(struct super_block *sb);
82 static inline int ext3_feature_set_ok(struct super_block *sb);
83 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
84 static void ext4_destroy_lazyinit_thread(void);
85 static void ext4_unregister_li_request(struct super_block *sb);
86 static void ext4_clear_request_list(void);
87 static struct inode *ext4_get_journal_inode(struct super_block *sb,
88 					    unsigned int journal_inum);
89 
90 /*
91  * Lock ordering
92  *
93  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
94  * i_mmap_rwsem (inode->i_mmap_rwsem)!
95  *
96  * page fault path:
97  * mmap_lock -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
98  *   page lock -> i_data_sem (rw)
99  *
100  * buffered write path:
101  * sb_start_write -> i_mutex -> mmap_lock
102  * sb_start_write -> i_mutex -> transaction start -> page lock ->
103  *   i_data_sem (rw)
104  *
105  * truncate:
106  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
107  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
108  *   i_data_sem (rw)
109  *
110  * direct IO:
111  * sb_start_write -> i_mutex -> mmap_lock
112  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
113  *
114  * writepages:
115  * transaction start -> page lock(s) -> i_data_sem (rw)
116  */
117 
118 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
119 static struct file_system_type ext2_fs_type = {
120 	.owner		= THIS_MODULE,
121 	.name		= "ext2",
122 	.mount		= ext4_mount,
123 	.kill_sb	= kill_block_super,
124 	.fs_flags	= FS_REQUIRES_DEV,
125 };
126 MODULE_ALIAS_FS("ext2");
127 MODULE_ALIAS("ext2");
128 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
129 #else
130 #define IS_EXT2_SB(sb) (0)
131 #endif
132 
133 
134 static struct file_system_type ext3_fs_type = {
135 	.owner		= THIS_MODULE,
136 	.name		= "ext3",
137 	.mount		= ext4_mount,
138 	.kill_sb	= kill_block_super,
139 	.fs_flags	= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext3");
142 MODULE_ALIAS("ext3");
143 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
144 
145 
146 static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags,
147 				  bh_end_io_t *end_io)
148 {
149 	/*
150 	 * buffer's verified bit is no longer valid after reading from
151 	 * disk again due to write out error, clear it to make sure we
152 	 * recheck the buffer contents.
153 	 */
154 	clear_buffer_verified(bh);
155 
156 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
157 	get_bh(bh);
158 	submit_bh(REQ_OP_READ, op_flags, bh);
159 }
160 
161 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
162 			 bh_end_io_t *end_io)
163 {
164 	BUG_ON(!buffer_locked(bh));
165 
166 	if (ext4_buffer_uptodate(bh)) {
167 		unlock_buffer(bh);
168 		return;
169 	}
170 	__ext4_read_bh(bh, op_flags, end_io);
171 }
172 
173 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
174 {
175 	BUG_ON(!buffer_locked(bh));
176 
177 	if (ext4_buffer_uptodate(bh)) {
178 		unlock_buffer(bh);
179 		return 0;
180 	}
181 
182 	__ext4_read_bh(bh, op_flags, end_io);
183 
184 	wait_on_buffer(bh);
185 	if (buffer_uptodate(bh))
186 		return 0;
187 	return -EIO;
188 }
189 
190 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
191 {
192 	if (trylock_buffer(bh)) {
193 		if (wait)
194 			return ext4_read_bh(bh, op_flags, NULL);
195 		ext4_read_bh_nowait(bh, op_flags, NULL);
196 		return 0;
197 	}
198 	if (wait) {
199 		wait_on_buffer(bh);
200 		if (buffer_uptodate(bh))
201 			return 0;
202 		return -EIO;
203 	}
204 	return 0;
205 }
206 
207 /*
208  * This works like __bread_gfp() except it uses ERR_PTR for error
209  * returns.  Currently with sb_bread it's impossible to distinguish
210  * between ENOMEM and EIO situations (since both result in a NULL
211  * return.
212  */
213 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
214 					       sector_t block, int op_flags,
215 					       gfp_t gfp)
216 {
217 	struct buffer_head *bh;
218 	int ret;
219 
220 	bh = sb_getblk_gfp(sb, block, gfp);
221 	if (bh == NULL)
222 		return ERR_PTR(-ENOMEM);
223 	if (ext4_buffer_uptodate(bh))
224 		return bh;
225 
226 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
227 	if (ret) {
228 		put_bh(bh);
229 		return ERR_PTR(ret);
230 	}
231 	return bh;
232 }
233 
234 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
235 				   int op_flags)
236 {
237 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
238 }
239 
240 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
241 					    sector_t block)
242 {
243 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
244 }
245 
246 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
247 {
248 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
249 
250 	if (likely(bh)) {
251 		ext4_read_bh_lock(bh, REQ_RAHEAD, false);
252 		brelse(bh);
253 	}
254 }
255 
256 static int ext4_verify_csum_type(struct super_block *sb,
257 				 struct ext4_super_block *es)
258 {
259 	if (!ext4_has_feature_metadata_csum(sb))
260 		return 1;
261 
262 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
263 }
264 
265 static __le32 ext4_superblock_csum(struct super_block *sb,
266 				   struct ext4_super_block *es)
267 {
268 	struct ext4_sb_info *sbi = EXT4_SB(sb);
269 	int offset = offsetof(struct ext4_super_block, s_checksum);
270 	__u32 csum;
271 
272 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
273 
274 	return cpu_to_le32(csum);
275 }
276 
277 static int ext4_superblock_csum_verify(struct super_block *sb,
278 				       struct ext4_super_block *es)
279 {
280 	if (!ext4_has_metadata_csum(sb))
281 		return 1;
282 
283 	return es->s_checksum == ext4_superblock_csum(sb, es);
284 }
285 
286 void ext4_superblock_csum_set(struct super_block *sb)
287 {
288 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
289 
290 	if (!ext4_has_metadata_csum(sb))
291 		return;
292 
293 	es->s_checksum = ext4_superblock_csum(sb, es);
294 }
295 
296 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
297 			       struct ext4_group_desc *bg)
298 {
299 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
300 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
301 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
302 }
303 
304 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
305 			       struct ext4_group_desc *bg)
306 {
307 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
308 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
309 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
310 }
311 
312 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
313 			      struct ext4_group_desc *bg)
314 {
315 	return le32_to_cpu(bg->bg_inode_table_lo) |
316 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
317 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
318 }
319 
320 __u32 ext4_free_group_clusters(struct super_block *sb,
321 			       struct ext4_group_desc *bg)
322 {
323 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
324 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
325 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
326 }
327 
328 __u32 ext4_free_inodes_count(struct super_block *sb,
329 			      struct ext4_group_desc *bg)
330 {
331 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
332 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
333 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
334 }
335 
336 __u32 ext4_used_dirs_count(struct super_block *sb,
337 			      struct ext4_group_desc *bg)
338 {
339 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
340 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
341 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
342 }
343 
344 __u32 ext4_itable_unused_count(struct super_block *sb,
345 			      struct ext4_group_desc *bg)
346 {
347 	return le16_to_cpu(bg->bg_itable_unused_lo) |
348 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
349 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
350 }
351 
352 void ext4_block_bitmap_set(struct super_block *sb,
353 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
354 {
355 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
356 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
357 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
358 }
359 
360 void ext4_inode_bitmap_set(struct super_block *sb,
361 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
362 {
363 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
364 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
365 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
366 }
367 
368 void ext4_inode_table_set(struct super_block *sb,
369 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
370 {
371 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
372 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
373 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
374 }
375 
376 void ext4_free_group_clusters_set(struct super_block *sb,
377 				  struct ext4_group_desc *bg, __u32 count)
378 {
379 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
380 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
381 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
382 }
383 
384 void ext4_free_inodes_set(struct super_block *sb,
385 			  struct ext4_group_desc *bg, __u32 count)
386 {
387 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
388 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
389 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
390 }
391 
392 void ext4_used_dirs_set(struct super_block *sb,
393 			  struct ext4_group_desc *bg, __u32 count)
394 {
395 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
396 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
397 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
398 }
399 
400 void ext4_itable_unused_set(struct super_block *sb,
401 			  struct ext4_group_desc *bg, __u32 count)
402 {
403 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
404 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
405 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
406 }
407 
408 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
409 {
410 	now = clamp_val(now, 0, (1ull << 40) - 1);
411 
412 	*lo = cpu_to_le32(lower_32_bits(now));
413 	*hi = upper_32_bits(now);
414 }
415 
416 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
417 {
418 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
419 }
420 #define ext4_update_tstamp(es, tstamp) \
421 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
422 			     ktime_get_real_seconds())
423 #define ext4_get_tstamp(es, tstamp) \
424 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
425 
426 /*
427  * The del_gendisk() function uninitializes the disk-specific data
428  * structures, including the bdi structure, without telling anyone
429  * else.  Once this happens, any attempt to call mark_buffer_dirty()
430  * (for example, by ext4_commit_super), will cause a kernel OOPS.
431  * This is a kludge to prevent these oops until we can put in a proper
432  * hook in del_gendisk() to inform the VFS and file system layers.
433  */
434 static int block_device_ejected(struct super_block *sb)
435 {
436 	struct inode *bd_inode = sb->s_bdev->bd_inode;
437 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
438 
439 	return bdi->dev == NULL;
440 }
441 
442 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
443 {
444 	struct super_block		*sb = journal->j_private;
445 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
446 	int				error = is_journal_aborted(journal);
447 	struct ext4_journal_cb_entry	*jce;
448 
449 	BUG_ON(txn->t_state == T_FINISHED);
450 
451 	ext4_process_freed_data(sb, txn->t_tid);
452 
453 	spin_lock(&sbi->s_md_lock);
454 	while (!list_empty(&txn->t_private_list)) {
455 		jce = list_entry(txn->t_private_list.next,
456 				 struct ext4_journal_cb_entry, jce_list);
457 		list_del_init(&jce->jce_list);
458 		spin_unlock(&sbi->s_md_lock);
459 		jce->jce_func(sb, jce, error);
460 		spin_lock(&sbi->s_md_lock);
461 	}
462 	spin_unlock(&sbi->s_md_lock);
463 }
464 
465 /*
466  * This writepage callback for write_cache_pages()
467  * takes care of a few cases after page cleaning.
468  *
469  * write_cache_pages() already checks for dirty pages
470  * and calls clear_page_dirty_for_io(), which we want,
471  * to write protect the pages.
472  *
473  * However, we may have to redirty a page (see below.)
474  */
475 static int ext4_journalled_writepage_callback(struct page *page,
476 					      struct writeback_control *wbc,
477 					      void *data)
478 {
479 	transaction_t *transaction = (transaction_t *) data;
480 	struct buffer_head *bh, *head;
481 	struct journal_head *jh;
482 
483 	bh = head = page_buffers(page);
484 	do {
485 		/*
486 		 * We have to redirty a page in these cases:
487 		 * 1) If buffer is dirty, it means the page was dirty because it
488 		 * contains a buffer that needs checkpointing. So the dirty bit
489 		 * needs to be preserved so that checkpointing writes the buffer
490 		 * properly.
491 		 * 2) If buffer is not part of the committing transaction
492 		 * (we may have just accidentally come across this buffer because
493 		 * inode range tracking is not exact) or if the currently running
494 		 * transaction already contains this buffer as well, dirty bit
495 		 * needs to be preserved so that the buffer gets writeprotected
496 		 * properly on running transaction's commit.
497 		 */
498 		jh = bh2jh(bh);
499 		if (buffer_dirty(bh) ||
500 		    (jh && (jh->b_transaction != transaction ||
501 			    jh->b_next_transaction))) {
502 			redirty_page_for_writepage(wbc, page);
503 			goto out;
504 		}
505 	} while ((bh = bh->b_this_page) != head);
506 
507 out:
508 	return AOP_WRITEPAGE_ACTIVATE;
509 }
510 
511 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
512 {
513 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
514 	struct writeback_control wbc = {
515 		.sync_mode =  WB_SYNC_ALL,
516 		.nr_to_write = LONG_MAX,
517 		.range_start = jinode->i_dirty_start,
518 		.range_end = jinode->i_dirty_end,
519         };
520 
521 	return write_cache_pages(mapping, &wbc,
522 				 ext4_journalled_writepage_callback,
523 				 jinode->i_transaction);
524 }
525 
526 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
527 {
528 	int ret;
529 
530 	if (ext4_should_journal_data(jinode->i_vfs_inode))
531 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
532 	else
533 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
534 
535 	return ret;
536 }
537 
538 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
539 {
540 	int ret = 0;
541 
542 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
543 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
544 
545 	return ret;
546 }
547 
548 static bool system_going_down(void)
549 {
550 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
551 		|| system_state == SYSTEM_RESTART;
552 }
553 
554 struct ext4_err_translation {
555 	int code;
556 	int errno;
557 };
558 
559 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
560 
561 static struct ext4_err_translation err_translation[] = {
562 	EXT4_ERR_TRANSLATE(EIO),
563 	EXT4_ERR_TRANSLATE(ENOMEM),
564 	EXT4_ERR_TRANSLATE(EFSBADCRC),
565 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
566 	EXT4_ERR_TRANSLATE(ENOSPC),
567 	EXT4_ERR_TRANSLATE(ENOKEY),
568 	EXT4_ERR_TRANSLATE(EROFS),
569 	EXT4_ERR_TRANSLATE(EFBIG),
570 	EXT4_ERR_TRANSLATE(EEXIST),
571 	EXT4_ERR_TRANSLATE(ERANGE),
572 	EXT4_ERR_TRANSLATE(EOVERFLOW),
573 	EXT4_ERR_TRANSLATE(EBUSY),
574 	EXT4_ERR_TRANSLATE(ENOTDIR),
575 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
576 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
577 	EXT4_ERR_TRANSLATE(EFAULT),
578 };
579 
580 static int ext4_errno_to_code(int errno)
581 {
582 	int i;
583 
584 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
585 		if (err_translation[i].errno == errno)
586 			return err_translation[i].code;
587 	return EXT4_ERR_UNKNOWN;
588 }
589 
590 static void save_error_info(struct super_block *sb, int error,
591 			    __u32 ino, __u64 block,
592 			    const char *func, unsigned int line)
593 {
594 	struct ext4_sb_info *sbi = EXT4_SB(sb);
595 
596 	/* We default to EFSCORRUPTED error... */
597 	if (error == 0)
598 		error = EFSCORRUPTED;
599 
600 	spin_lock(&sbi->s_error_lock);
601 	sbi->s_add_error_count++;
602 	sbi->s_last_error_code = error;
603 	sbi->s_last_error_line = line;
604 	sbi->s_last_error_ino = ino;
605 	sbi->s_last_error_block = block;
606 	sbi->s_last_error_func = func;
607 	sbi->s_last_error_time = ktime_get_real_seconds();
608 	if (!sbi->s_first_error_time) {
609 		sbi->s_first_error_code = error;
610 		sbi->s_first_error_line = line;
611 		sbi->s_first_error_ino = ino;
612 		sbi->s_first_error_block = block;
613 		sbi->s_first_error_func = func;
614 		sbi->s_first_error_time = sbi->s_last_error_time;
615 	}
616 	spin_unlock(&sbi->s_error_lock);
617 }
618 
619 /* Deal with the reporting of failure conditions on a filesystem such as
620  * inconsistencies detected or read IO failures.
621  *
622  * On ext2, we can store the error state of the filesystem in the
623  * superblock.  That is not possible on ext4, because we may have other
624  * write ordering constraints on the superblock which prevent us from
625  * writing it out straight away; and given that the journal is about to
626  * be aborted, we can't rely on the current, or future, transactions to
627  * write out the superblock safely.
628  *
629  * We'll just use the jbd2_journal_abort() error code to record an error in
630  * the journal instead.  On recovery, the journal will complain about
631  * that error until we've noted it down and cleared it.
632  *
633  * If force_ro is set, we unconditionally force the filesystem into an
634  * ABORT|READONLY state, unless the error response on the fs has been set to
635  * panic in which case we take the easy way out and panic immediately. This is
636  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
637  * at a critical moment in log management.
638  */
639 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
640 			      __u32 ino, __u64 block,
641 			      const char *func, unsigned int line)
642 {
643 	journal_t *journal = EXT4_SB(sb)->s_journal;
644 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
645 
646 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
647 	if (test_opt(sb, WARN_ON_ERROR))
648 		WARN_ON_ONCE(1);
649 
650 	if (!continue_fs && !sb_rdonly(sb)) {
651 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
652 		if (journal)
653 			jbd2_journal_abort(journal, -EIO);
654 	}
655 
656 	if (!bdev_read_only(sb->s_bdev)) {
657 		save_error_info(sb, error, ino, block, func, line);
658 		/*
659 		 * In case the fs should keep running, we need to writeout
660 		 * superblock through the journal. Due to lock ordering
661 		 * constraints, it may not be safe to do it right here so we
662 		 * defer superblock flushing to a workqueue.
663 		 */
664 		if (continue_fs)
665 			schedule_work(&EXT4_SB(sb)->s_error_work);
666 		else
667 			ext4_commit_super(sb);
668 	}
669 
670 	/*
671 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
672 	 * could panic during 'reboot -f' as the underlying device got already
673 	 * disabled.
674 	 */
675 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
676 		panic("EXT4-fs (device %s): panic forced after error\n",
677 			sb->s_id);
678 	}
679 
680 	if (sb_rdonly(sb) || continue_fs)
681 		return;
682 
683 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
684 	/*
685 	 * Make sure updated value of ->s_mount_flags will be visible before
686 	 * ->s_flags update
687 	 */
688 	smp_wmb();
689 	sb->s_flags |= SB_RDONLY;
690 }
691 
692 static void flush_stashed_error_work(struct work_struct *work)
693 {
694 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
695 						s_error_work);
696 	journal_t *journal = sbi->s_journal;
697 	handle_t *handle;
698 
699 	/*
700 	 * If the journal is still running, we have to write out superblock
701 	 * through the journal to avoid collisions of other journalled sb
702 	 * updates.
703 	 *
704 	 * We use directly jbd2 functions here to avoid recursing back into
705 	 * ext4 error handling code during handling of previous errors.
706 	 */
707 	if (!sb_rdonly(sbi->s_sb) && journal) {
708 		handle = jbd2_journal_start(journal, 1);
709 		if (IS_ERR(handle))
710 			goto write_directly;
711 		if (jbd2_journal_get_write_access(handle, sbi->s_sbh)) {
712 			jbd2_journal_stop(handle);
713 			goto write_directly;
714 		}
715 		ext4_update_super(sbi->s_sb);
716 		if (jbd2_journal_dirty_metadata(handle, sbi->s_sbh)) {
717 			jbd2_journal_stop(handle);
718 			goto write_directly;
719 		}
720 		jbd2_journal_stop(handle);
721 		return;
722 	}
723 write_directly:
724 	/*
725 	 * Write through journal failed. Write sb directly to get error info
726 	 * out and hope for the best.
727 	 */
728 	ext4_commit_super(sbi->s_sb);
729 }
730 
731 #define ext4_error_ratelimit(sb)					\
732 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
733 			     "EXT4-fs error")
734 
735 void __ext4_error(struct super_block *sb, const char *function,
736 		  unsigned int line, bool force_ro, int error, __u64 block,
737 		  const char *fmt, ...)
738 {
739 	struct va_format vaf;
740 	va_list args;
741 
742 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
743 		return;
744 
745 	trace_ext4_error(sb, function, line);
746 	if (ext4_error_ratelimit(sb)) {
747 		va_start(args, fmt);
748 		vaf.fmt = fmt;
749 		vaf.va = &args;
750 		printk(KERN_CRIT
751 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
752 		       sb->s_id, function, line, current->comm, &vaf);
753 		va_end(args);
754 	}
755 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
756 }
757 
758 void __ext4_error_inode(struct inode *inode, const char *function,
759 			unsigned int line, ext4_fsblk_t block, int error,
760 			const char *fmt, ...)
761 {
762 	va_list args;
763 	struct va_format vaf;
764 
765 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
766 		return;
767 
768 	trace_ext4_error(inode->i_sb, function, line);
769 	if (ext4_error_ratelimit(inode->i_sb)) {
770 		va_start(args, fmt);
771 		vaf.fmt = fmt;
772 		vaf.va = &args;
773 		if (block)
774 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
775 			       "inode #%lu: block %llu: comm %s: %pV\n",
776 			       inode->i_sb->s_id, function, line, inode->i_ino,
777 			       block, current->comm, &vaf);
778 		else
779 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
780 			       "inode #%lu: comm %s: %pV\n",
781 			       inode->i_sb->s_id, function, line, inode->i_ino,
782 			       current->comm, &vaf);
783 		va_end(args);
784 	}
785 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
786 			  function, line);
787 }
788 
789 void __ext4_error_file(struct file *file, const char *function,
790 		       unsigned int line, ext4_fsblk_t block,
791 		       const char *fmt, ...)
792 {
793 	va_list args;
794 	struct va_format vaf;
795 	struct inode *inode = file_inode(file);
796 	char pathname[80], *path;
797 
798 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
799 		return;
800 
801 	trace_ext4_error(inode->i_sb, function, line);
802 	if (ext4_error_ratelimit(inode->i_sb)) {
803 		path = file_path(file, pathname, sizeof(pathname));
804 		if (IS_ERR(path))
805 			path = "(unknown)";
806 		va_start(args, fmt);
807 		vaf.fmt = fmt;
808 		vaf.va = &args;
809 		if (block)
810 			printk(KERN_CRIT
811 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
812 			       "block %llu: comm %s: path %s: %pV\n",
813 			       inode->i_sb->s_id, function, line, inode->i_ino,
814 			       block, current->comm, path, &vaf);
815 		else
816 			printk(KERN_CRIT
817 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
818 			       "comm %s: path %s: %pV\n",
819 			       inode->i_sb->s_id, function, line, inode->i_ino,
820 			       current->comm, path, &vaf);
821 		va_end(args);
822 	}
823 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
824 			  function, line);
825 }
826 
827 const char *ext4_decode_error(struct super_block *sb, int errno,
828 			      char nbuf[16])
829 {
830 	char *errstr = NULL;
831 
832 	switch (errno) {
833 	case -EFSCORRUPTED:
834 		errstr = "Corrupt filesystem";
835 		break;
836 	case -EFSBADCRC:
837 		errstr = "Filesystem failed CRC";
838 		break;
839 	case -EIO:
840 		errstr = "IO failure";
841 		break;
842 	case -ENOMEM:
843 		errstr = "Out of memory";
844 		break;
845 	case -EROFS:
846 		if (!sb || (EXT4_SB(sb)->s_journal &&
847 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
848 			errstr = "Journal has aborted";
849 		else
850 			errstr = "Readonly filesystem";
851 		break;
852 	default:
853 		/* If the caller passed in an extra buffer for unknown
854 		 * errors, textualise them now.  Else we just return
855 		 * NULL. */
856 		if (nbuf) {
857 			/* Check for truncated error codes... */
858 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
859 				errstr = nbuf;
860 		}
861 		break;
862 	}
863 
864 	return errstr;
865 }
866 
867 /* __ext4_std_error decodes expected errors from journaling functions
868  * automatically and invokes the appropriate error response.  */
869 
870 void __ext4_std_error(struct super_block *sb, const char *function,
871 		      unsigned int line, int errno)
872 {
873 	char nbuf[16];
874 	const char *errstr;
875 
876 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
877 		return;
878 
879 	/* Special case: if the error is EROFS, and we're not already
880 	 * inside a transaction, then there's really no point in logging
881 	 * an error. */
882 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
883 		return;
884 
885 	if (ext4_error_ratelimit(sb)) {
886 		errstr = ext4_decode_error(sb, errno, nbuf);
887 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
888 		       sb->s_id, function, line, errstr);
889 	}
890 
891 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
892 }
893 
894 void __ext4_msg(struct super_block *sb,
895 		const char *prefix, const char *fmt, ...)
896 {
897 	struct va_format vaf;
898 	va_list args;
899 
900 	atomic_inc(&EXT4_SB(sb)->s_msg_count);
901 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
902 		return;
903 
904 	va_start(args, fmt);
905 	vaf.fmt = fmt;
906 	vaf.va = &args;
907 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
908 	va_end(args);
909 }
910 
911 static int ext4_warning_ratelimit(struct super_block *sb)
912 {
913 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
914 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
915 			    "EXT4-fs warning");
916 }
917 
918 void __ext4_warning(struct super_block *sb, const char *function,
919 		    unsigned int line, const char *fmt, ...)
920 {
921 	struct va_format vaf;
922 	va_list args;
923 
924 	if (!ext4_warning_ratelimit(sb))
925 		return;
926 
927 	va_start(args, fmt);
928 	vaf.fmt = fmt;
929 	vaf.va = &args;
930 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
931 	       sb->s_id, function, line, &vaf);
932 	va_end(args);
933 }
934 
935 void __ext4_warning_inode(const struct inode *inode, const char *function,
936 			  unsigned int line, const char *fmt, ...)
937 {
938 	struct va_format vaf;
939 	va_list args;
940 
941 	if (!ext4_warning_ratelimit(inode->i_sb))
942 		return;
943 
944 	va_start(args, fmt);
945 	vaf.fmt = fmt;
946 	vaf.va = &args;
947 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
948 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
949 	       function, line, inode->i_ino, current->comm, &vaf);
950 	va_end(args);
951 }
952 
953 void __ext4_grp_locked_error(const char *function, unsigned int line,
954 			     struct super_block *sb, ext4_group_t grp,
955 			     unsigned long ino, ext4_fsblk_t block,
956 			     const char *fmt, ...)
957 __releases(bitlock)
958 __acquires(bitlock)
959 {
960 	struct va_format vaf;
961 	va_list args;
962 
963 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
964 		return;
965 
966 	trace_ext4_error(sb, function, line);
967 	if (ext4_error_ratelimit(sb)) {
968 		va_start(args, fmt);
969 		vaf.fmt = fmt;
970 		vaf.va = &args;
971 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
972 		       sb->s_id, function, line, grp);
973 		if (ino)
974 			printk(KERN_CONT "inode %lu: ", ino);
975 		if (block)
976 			printk(KERN_CONT "block %llu:",
977 			       (unsigned long long) block);
978 		printk(KERN_CONT "%pV\n", &vaf);
979 		va_end(args);
980 	}
981 
982 	if (test_opt(sb, ERRORS_CONT)) {
983 		if (test_opt(sb, WARN_ON_ERROR))
984 			WARN_ON_ONCE(1);
985 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
986 		if (!bdev_read_only(sb->s_bdev)) {
987 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
988 					line);
989 			schedule_work(&EXT4_SB(sb)->s_error_work);
990 		}
991 		return;
992 	}
993 	ext4_unlock_group(sb, grp);
994 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
995 	/*
996 	 * We only get here in the ERRORS_RO case; relocking the group
997 	 * may be dangerous, but nothing bad will happen since the
998 	 * filesystem will have already been marked read/only and the
999 	 * journal has been aborted.  We return 1 as a hint to callers
1000 	 * who might what to use the return value from
1001 	 * ext4_grp_locked_error() to distinguish between the
1002 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1003 	 * aggressively from the ext4 function in question, with a
1004 	 * more appropriate error code.
1005 	 */
1006 	ext4_lock_group(sb, grp);
1007 	return;
1008 }
1009 
1010 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1011 				     ext4_group_t group,
1012 				     unsigned int flags)
1013 {
1014 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1015 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1016 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1017 	int ret;
1018 
1019 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1020 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1021 					    &grp->bb_state);
1022 		if (!ret)
1023 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1024 					   grp->bb_free);
1025 	}
1026 
1027 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1028 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1029 					    &grp->bb_state);
1030 		if (!ret && gdp) {
1031 			int count;
1032 
1033 			count = ext4_free_inodes_count(sb, gdp);
1034 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1035 					   count);
1036 		}
1037 	}
1038 }
1039 
1040 void ext4_update_dynamic_rev(struct super_block *sb)
1041 {
1042 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1043 
1044 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1045 		return;
1046 
1047 	ext4_warning(sb,
1048 		     "updating to rev %d because of new feature flag, "
1049 		     "running e2fsck is recommended",
1050 		     EXT4_DYNAMIC_REV);
1051 
1052 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1053 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1054 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1055 	/* leave es->s_feature_*compat flags alone */
1056 	/* es->s_uuid will be set by e2fsck if empty */
1057 
1058 	/*
1059 	 * The rest of the superblock fields should be zero, and if not it
1060 	 * means they are likely already in use, so leave them alone.  We
1061 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1062 	 */
1063 }
1064 
1065 /*
1066  * Open the external journal device
1067  */
1068 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1069 {
1070 	struct block_device *bdev;
1071 
1072 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1073 	if (IS_ERR(bdev))
1074 		goto fail;
1075 	return bdev;
1076 
1077 fail:
1078 	ext4_msg(sb, KERN_ERR,
1079 		 "failed to open journal device unknown-block(%u,%u) %ld",
1080 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1081 	return NULL;
1082 }
1083 
1084 /*
1085  * Release the journal device
1086  */
1087 static void ext4_blkdev_put(struct block_device *bdev)
1088 {
1089 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1090 }
1091 
1092 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1093 {
1094 	struct block_device *bdev;
1095 	bdev = sbi->s_journal_bdev;
1096 	if (bdev) {
1097 		ext4_blkdev_put(bdev);
1098 		sbi->s_journal_bdev = NULL;
1099 	}
1100 }
1101 
1102 static inline struct inode *orphan_list_entry(struct list_head *l)
1103 {
1104 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1105 }
1106 
1107 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1108 {
1109 	struct list_head *l;
1110 
1111 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1112 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1113 
1114 	printk(KERN_ERR "sb_info orphan list:\n");
1115 	list_for_each(l, &sbi->s_orphan) {
1116 		struct inode *inode = orphan_list_entry(l);
1117 		printk(KERN_ERR "  "
1118 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1119 		       inode->i_sb->s_id, inode->i_ino, inode,
1120 		       inode->i_mode, inode->i_nlink,
1121 		       NEXT_ORPHAN(inode));
1122 	}
1123 }
1124 
1125 #ifdef CONFIG_QUOTA
1126 static int ext4_quota_off(struct super_block *sb, int type);
1127 
1128 static inline void ext4_quota_off_umount(struct super_block *sb)
1129 {
1130 	int type;
1131 
1132 	/* Use our quota_off function to clear inode flags etc. */
1133 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1134 		ext4_quota_off(sb, type);
1135 }
1136 
1137 /*
1138  * This is a helper function which is used in the mount/remount
1139  * codepaths (which holds s_umount) to fetch the quota file name.
1140  */
1141 static inline char *get_qf_name(struct super_block *sb,
1142 				struct ext4_sb_info *sbi,
1143 				int type)
1144 {
1145 	return rcu_dereference_protected(sbi->s_qf_names[type],
1146 					 lockdep_is_held(&sb->s_umount));
1147 }
1148 #else
1149 static inline void ext4_quota_off_umount(struct super_block *sb)
1150 {
1151 }
1152 #endif
1153 
1154 static void ext4_put_super(struct super_block *sb)
1155 {
1156 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1157 	struct ext4_super_block *es = sbi->s_es;
1158 	struct buffer_head **group_desc;
1159 	struct flex_groups **flex_groups;
1160 	int aborted = 0;
1161 	int i, err;
1162 
1163 	ext4_unregister_li_request(sb);
1164 	ext4_quota_off_umount(sb);
1165 
1166 	flush_work(&sbi->s_error_work);
1167 	destroy_workqueue(sbi->rsv_conversion_wq);
1168 
1169 	/*
1170 	 * Unregister sysfs before destroying jbd2 journal.
1171 	 * Since we could still access attr_journal_task attribute via sysfs
1172 	 * path which could have sbi->s_journal->j_task as NULL
1173 	 */
1174 	ext4_unregister_sysfs(sb);
1175 
1176 	if (sbi->s_journal) {
1177 		aborted = is_journal_aborted(sbi->s_journal);
1178 		err = jbd2_journal_destroy(sbi->s_journal);
1179 		sbi->s_journal = NULL;
1180 		if ((err < 0) && !aborted) {
1181 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1182 		}
1183 	}
1184 
1185 	ext4_es_unregister_shrinker(sbi);
1186 	del_timer_sync(&sbi->s_err_report);
1187 	ext4_release_system_zone(sb);
1188 	ext4_mb_release(sb);
1189 	ext4_ext_release(sb);
1190 
1191 	if (!sb_rdonly(sb) && !aborted) {
1192 		ext4_clear_feature_journal_needs_recovery(sb);
1193 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1194 	}
1195 	if (!sb_rdonly(sb))
1196 		ext4_commit_super(sb);
1197 
1198 	rcu_read_lock();
1199 	group_desc = rcu_dereference(sbi->s_group_desc);
1200 	for (i = 0; i < sbi->s_gdb_count; i++)
1201 		brelse(group_desc[i]);
1202 	kvfree(group_desc);
1203 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1204 	if (flex_groups) {
1205 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1206 			kvfree(flex_groups[i]);
1207 		kvfree(flex_groups);
1208 	}
1209 	rcu_read_unlock();
1210 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1211 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1212 	percpu_counter_destroy(&sbi->s_dirs_counter);
1213 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1214 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1215 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1216 #ifdef CONFIG_QUOTA
1217 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1218 		kfree(get_qf_name(sb, sbi, i));
1219 #endif
1220 
1221 	/* Debugging code just in case the in-memory inode orphan list
1222 	 * isn't empty.  The on-disk one can be non-empty if we've
1223 	 * detected an error and taken the fs readonly, but the
1224 	 * in-memory list had better be clean by this point. */
1225 	if (!list_empty(&sbi->s_orphan))
1226 		dump_orphan_list(sb, sbi);
1227 	ASSERT(list_empty(&sbi->s_orphan));
1228 
1229 	sync_blockdev(sb->s_bdev);
1230 	invalidate_bdev(sb->s_bdev);
1231 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1232 		/*
1233 		 * Invalidate the journal device's buffers.  We don't want them
1234 		 * floating about in memory - the physical journal device may
1235 		 * hotswapped, and it breaks the `ro-after' testing code.
1236 		 */
1237 		sync_blockdev(sbi->s_journal_bdev);
1238 		invalidate_bdev(sbi->s_journal_bdev);
1239 		ext4_blkdev_remove(sbi);
1240 	}
1241 
1242 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1243 	sbi->s_ea_inode_cache = NULL;
1244 
1245 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1246 	sbi->s_ea_block_cache = NULL;
1247 
1248 	if (sbi->s_mmp_tsk)
1249 		kthread_stop(sbi->s_mmp_tsk);
1250 	brelse(sbi->s_sbh);
1251 	sb->s_fs_info = NULL;
1252 	/*
1253 	 * Now that we are completely done shutting down the
1254 	 * superblock, we need to actually destroy the kobject.
1255 	 */
1256 	kobject_put(&sbi->s_kobj);
1257 	wait_for_completion(&sbi->s_kobj_unregister);
1258 	if (sbi->s_chksum_driver)
1259 		crypto_free_shash(sbi->s_chksum_driver);
1260 	kfree(sbi->s_blockgroup_lock);
1261 	fs_put_dax(sbi->s_daxdev);
1262 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1263 #ifdef CONFIG_UNICODE
1264 	utf8_unload(sb->s_encoding);
1265 #endif
1266 	kfree(sbi);
1267 }
1268 
1269 static struct kmem_cache *ext4_inode_cachep;
1270 
1271 /*
1272  * Called inside transaction, so use GFP_NOFS
1273  */
1274 static struct inode *ext4_alloc_inode(struct super_block *sb)
1275 {
1276 	struct ext4_inode_info *ei;
1277 
1278 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1279 	if (!ei)
1280 		return NULL;
1281 
1282 	inode_set_iversion(&ei->vfs_inode, 1);
1283 	spin_lock_init(&ei->i_raw_lock);
1284 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1285 	atomic_set(&ei->i_prealloc_active, 0);
1286 	spin_lock_init(&ei->i_prealloc_lock);
1287 	ext4_es_init_tree(&ei->i_es_tree);
1288 	rwlock_init(&ei->i_es_lock);
1289 	INIT_LIST_HEAD(&ei->i_es_list);
1290 	ei->i_es_all_nr = 0;
1291 	ei->i_es_shk_nr = 0;
1292 	ei->i_es_shrink_lblk = 0;
1293 	ei->i_reserved_data_blocks = 0;
1294 	spin_lock_init(&(ei->i_block_reservation_lock));
1295 	ext4_init_pending_tree(&ei->i_pending_tree);
1296 #ifdef CONFIG_QUOTA
1297 	ei->i_reserved_quota = 0;
1298 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1299 #endif
1300 	ei->jinode = NULL;
1301 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1302 	spin_lock_init(&ei->i_completed_io_lock);
1303 	ei->i_sync_tid = 0;
1304 	ei->i_datasync_tid = 0;
1305 	atomic_set(&ei->i_unwritten, 0);
1306 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1307 	ext4_fc_init_inode(&ei->vfs_inode);
1308 	mutex_init(&ei->i_fc_lock);
1309 	return &ei->vfs_inode;
1310 }
1311 
1312 static int ext4_drop_inode(struct inode *inode)
1313 {
1314 	int drop = generic_drop_inode(inode);
1315 
1316 	if (!drop)
1317 		drop = fscrypt_drop_inode(inode);
1318 
1319 	trace_ext4_drop_inode(inode, drop);
1320 	return drop;
1321 }
1322 
1323 static void ext4_free_in_core_inode(struct inode *inode)
1324 {
1325 	fscrypt_free_inode(inode);
1326 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1327 		pr_warn("%s: inode %ld still in fc list",
1328 			__func__, inode->i_ino);
1329 	}
1330 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1331 }
1332 
1333 static void ext4_destroy_inode(struct inode *inode)
1334 {
1335 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1336 		ext4_msg(inode->i_sb, KERN_ERR,
1337 			 "Inode %lu (%p): orphan list check failed!",
1338 			 inode->i_ino, EXT4_I(inode));
1339 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1340 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1341 				true);
1342 		dump_stack();
1343 	}
1344 }
1345 
1346 static void init_once(void *foo)
1347 {
1348 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1349 
1350 	INIT_LIST_HEAD(&ei->i_orphan);
1351 	init_rwsem(&ei->xattr_sem);
1352 	init_rwsem(&ei->i_data_sem);
1353 	init_rwsem(&ei->i_mmap_sem);
1354 	inode_init_once(&ei->vfs_inode);
1355 	ext4_fc_init_inode(&ei->vfs_inode);
1356 }
1357 
1358 static int __init init_inodecache(void)
1359 {
1360 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1361 				sizeof(struct ext4_inode_info), 0,
1362 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1363 					SLAB_ACCOUNT),
1364 				offsetof(struct ext4_inode_info, i_data),
1365 				sizeof_field(struct ext4_inode_info, i_data),
1366 				init_once);
1367 	if (ext4_inode_cachep == NULL)
1368 		return -ENOMEM;
1369 	return 0;
1370 }
1371 
1372 static void destroy_inodecache(void)
1373 {
1374 	/*
1375 	 * Make sure all delayed rcu free inodes are flushed before we
1376 	 * destroy cache.
1377 	 */
1378 	rcu_barrier();
1379 	kmem_cache_destroy(ext4_inode_cachep);
1380 }
1381 
1382 void ext4_clear_inode(struct inode *inode)
1383 {
1384 	ext4_fc_del(inode);
1385 	invalidate_inode_buffers(inode);
1386 	clear_inode(inode);
1387 	ext4_discard_preallocations(inode, 0);
1388 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1389 	dquot_drop(inode);
1390 	if (EXT4_I(inode)->jinode) {
1391 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1392 					       EXT4_I(inode)->jinode);
1393 		jbd2_free_inode(EXT4_I(inode)->jinode);
1394 		EXT4_I(inode)->jinode = NULL;
1395 	}
1396 	fscrypt_put_encryption_info(inode);
1397 	fsverity_cleanup_inode(inode);
1398 }
1399 
1400 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1401 					u64 ino, u32 generation)
1402 {
1403 	struct inode *inode;
1404 
1405 	/*
1406 	 * Currently we don't know the generation for parent directory, so
1407 	 * a generation of 0 means "accept any"
1408 	 */
1409 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1410 	if (IS_ERR(inode))
1411 		return ERR_CAST(inode);
1412 	if (generation && inode->i_generation != generation) {
1413 		iput(inode);
1414 		return ERR_PTR(-ESTALE);
1415 	}
1416 
1417 	return inode;
1418 }
1419 
1420 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1421 					int fh_len, int fh_type)
1422 {
1423 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1424 				    ext4_nfs_get_inode);
1425 }
1426 
1427 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1428 					int fh_len, int fh_type)
1429 {
1430 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1431 				    ext4_nfs_get_inode);
1432 }
1433 
1434 static int ext4_nfs_commit_metadata(struct inode *inode)
1435 {
1436 	struct writeback_control wbc = {
1437 		.sync_mode = WB_SYNC_ALL
1438 	};
1439 
1440 	trace_ext4_nfs_commit_metadata(inode);
1441 	return ext4_write_inode(inode, &wbc);
1442 }
1443 
1444 /*
1445  * Try to release metadata pages (indirect blocks, directories) which are
1446  * mapped via the block device.  Since these pages could have journal heads
1447  * which would prevent try_to_free_buffers() from freeing them, we must use
1448  * jbd2 layer's try_to_free_buffers() function to release them.
1449  */
1450 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1451 				 gfp_t wait)
1452 {
1453 	journal_t *journal = EXT4_SB(sb)->s_journal;
1454 
1455 	WARN_ON(PageChecked(page));
1456 	if (!page_has_buffers(page))
1457 		return 0;
1458 	if (journal)
1459 		return jbd2_journal_try_to_free_buffers(journal, page);
1460 
1461 	return try_to_free_buffers(page);
1462 }
1463 
1464 #ifdef CONFIG_FS_ENCRYPTION
1465 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1466 {
1467 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1468 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1469 }
1470 
1471 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1472 							void *fs_data)
1473 {
1474 	handle_t *handle = fs_data;
1475 	int res, res2, credits, retries = 0;
1476 
1477 	/*
1478 	 * Encrypting the root directory is not allowed because e2fsck expects
1479 	 * lost+found to exist and be unencrypted, and encrypting the root
1480 	 * directory would imply encrypting the lost+found directory as well as
1481 	 * the filename "lost+found" itself.
1482 	 */
1483 	if (inode->i_ino == EXT4_ROOT_INO)
1484 		return -EPERM;
1485 
1486 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1487 		return -EINVAL;
1488 
1489 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1490 		return -EOPNOTSUPP;
1491 
1492 	res = ext4_convert_inline_data(inode);
1493 	if (res)
1494 		return res;
1495 
1496 	/*
1497 	 * If a journal handle was specified, then the encryption context is
1498 	 * being set on a new inode via inheritance and is part of a larger
1499 	 * transaction to create the inode.  Otherwise the encryption context is
1500 	 * being set on an existing inode in its own transaction.  Only in the
1501 	 * latter case should the "retry on ENOSPC" logic be used.
1502 	 */
1503 
1504 	if (handle) {
1505 		res = ext4_xattr_set_handle(handle, inode,
1506 					    EXT4_XATTR_INDEX_ENCRYPTION,
1507 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1508 					    ctx, len, 0);
1509 		if (!res) {
1510 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1511 			ext4_clear_inode_state(inode,
1512 					EXT4_STATE_MAY_INLINE_DATA);
1513 			/*
1514 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1515 			 * S_DAX may be disabled
1516 			 */
1517 			ext4_set_inode_flags(inode, false);
1518 		}
1519 		return res;
1520 	}
1521 
1522 	res = dquot_initialize(inode);
1523 	if (res)
1524 		return res;
1525 retry:
1526 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1527 				     &credits);
1528 	if (res)
1529 		return res;
1530 
1531 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1532 	if (IS_ERR(handle))
1533 		return PTR_ERR(handle);
1534 
1535 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1536 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1537 				    ctx, len, 0);
1538 	if (!res) {
1539 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1540 		/*
1541 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1542 		 * S_DAX may be disabled
1543 		 */
1544 		ext4_set_inode_flags(inode, false);
1545 		res = ext4_mark_inode_dirty(handle, inode);
1546 		if (res)
1547 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1548 	}
1549 	res2 = ext4_journal_stop(handle);
1550 
1551 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1552 		goto retry;
1553 	if (!res)
1554 		res = res2;
1555 	return res;
1556 }
1557 
1558 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1559 {
1560 	return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1561 }
1562 
1563 static bool ext4_has_stable_inodes(struct super_block *sb)
1564 {
1565 	return ext4_has_feature_stable_inodes(sb);
1566 }
1567 
1568 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1569 				       int *ino_bits_ret, int *lblk_bits_ret)
1570 {
1571 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1572 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1573 }
1574 
1575 static const struct fscrypt_operations ext4_cryptops = {
1576 	.key_prefix		= "ext4:",
1577 	.get_context		= ext4_get_context,
1578 	.set_context		= ext4_set_context,
1579 	.get_dummy_policy	= ext4_get_dummy_policy,
1580 	.empty_dir		= ext4_empty_dir,
1581 	.max_namelen		= EXT4_NAME_LEN,
1582 	.has_stable_inodes	= ext4_has_stable_inodes,
1583 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1584 };
1585 #endif
1586 
1587 #ifdef CONFIG_QUOTA
1588 static const char * const quotatypes[] = INITQFNAMES;
1589 #define QTYPE2NAME(t) (quotatypes[t])
1590 
1591 static int ext4_write_dquot(struct dquot *dquot);
1592 static int ext4_acquire_dquot(struct dquot *dquot);
1593 static int ext4_release_dquot(struct dquot *dquot);
1594 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1595 static int ext4_write_info(struct super_block *sb, int type);
1596 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1597 			 const struct path *path);
1598 static int ext4_quota_on_mount(struct super_block *sb, int type);
1599 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1600 			       size_t len, loff_t off);
1601 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1602 				const char *data, size_t len, loff_t off);
1603 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1604 			     unsigned int flags);
1605 static int ext4_enable_quotas(struct super_block *sb);
1606 
1607 static struct dquot **ext4_get_dquots(struct inode *inode)
1608 {
1609 	return EXT4_I(inode)->i_dquot;
1610 }
1611 
1612 static const struct dquot_operations ext4_quota_operations = {
1613 	.get_reserved_space	= ext4_get_reserved_space,
1614 	.write_dquot		= ext4_write_dquot,
1615 	.acquire_dquot		= ext4_acquire_dquot,
1616 	.release_dquot		= ext4_release_dquot,
1617 	.mark_dirty		= ext4_mark_dquot_dirty,
1618 	.write_info		= ext4_write_info,
1619 	.alloc_dquot		= dquot_alloc,
1620 	.destroy_dquot		= dquot_destroy,
1621 	.get_projid		= ext4_get_projid,
1622 	.get_inode_usage	= ext4_get_inode_usage,
1623 	.get_next_id		= dquot_get_next_id,
1624 };
1625 
1626 static const struct quotactl_ops ext4_qctl_operations = {
1627 	.quota_on	= ext4_quota_on,
1628 	.quota_off	= ext4_quota_off,
1629 	.quota_sync	= dquot_quota_sync,
1630 	.get_state	= dquot_get_state,
1631 	.set_info	= dquot_set_dqinfo,
1632 	.get_dqblk	= dquot_get_dqblk,
1633 	.set_dqblk	= dquot_set_dqblk,
1634 	.get_nextdqblk	= dquot_get_next_dqblk,
1635 };
1636 #endif
1637 
1638 static const struct super_operations ext4_sops = {
1639 	.alloc_inode	= ext4_alloc_inode,
1640 	.free_inode	= ext4_free_in_core_inode,
1641 	.destroy_inode	= ext4_destroy_inode,
1642 	.write_inode	= ext4_write_inode,
1643 	.dirty_inode	= ext4_dirty_inode,
1644 	.drop_inode	= ext4_drop_inode,
1645 	.evict_inode	= ext4_evict_inode,
1646 	.put_super	= ext4_put_super,
1647 	.sync_fs	= ext4_sync_fs,
1648 	.freeze_fs	= ext4_freeze,
1649 	.unfreeze_fs	= ext4_unfreeze,
1650 	.statfs		= ext4_statfs,
1651 	.remount_fs	= ext4_remount,
1652 	.show_options	= ext4_show_options,
1653 #ifdef CONFIG_QUOTA
1654 	.quota_read	= ext4_quota_read,
1655 	.quota_write	= ext4_quota_write,
1656 	.get_dquots	= ext4_get_dquots,
1657 #endif
1658 	.bdev_try_to_free_page = bdev_try_to_free_page,
1659 };
1660 
1661 static const struct export_operations ext4_export_ops = {
1662 	.fh_to_dentry = ext4_fh_to_dentry,
1663 	.fh_to_parent = ext4_fh_to_parent,
1664 	.get_parent = ext4_get_parent,
1665 	.commit_metadata = ext4_nfs_commit_metadata,
1666 };
1667 
1668 enum {
1669 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1670 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1671 	Opt_nouid32, Opt_debug, Opt_removed,
1672 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1673 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1674 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1675 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1676 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1677 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1678 	Opt_inlinecrypt,
1679 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1680 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1681 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1682 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1683 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1684 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1685 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1686 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1687 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1688 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1689 	Opt_dioread_nolock, Opt_dioread_lock,
1690 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1691 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1692 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1693 #ifdef CONFIG_EXT4_DEBUG
1694 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1695 #endif
1696 };
1697 
1698 static const match_table_t tokens = {
1699 	{Opt_bsd_df, "bsddf"},
1700 	{Opt_minix_df, "minixdf"},
1701 	{Opt_grpid, "grpid"},
1702 	{Opt_grpid, "bsdgroups"},
1703 	{Opt_nogrpid, "nogrpid"},
1704 	{Opt_nogrpid, "sysvgroups"},
1705 	{Opt_resgid, "resgid=%u"},
1706 	{Opt_resuid, "resuid=%u"},
1707 	{Opt_sb, "sb=%u"},
1708 	{Opt_err_cont, "errors=continue"},
1709 	{Opt_err_panic, "errors=panic"},
1710 	{Opt_err_ro, "errors=remount-ro"},
1711 	{Opt_nouid32, "nouid32"},
1712 	{Opt_debug, "debug"},
1713 	{Opt_removed, "oldalloc"},
1714 	{Opt_removed, "orlov"},
1715 	{Opt_user_xattr, "user_xattr"},
1716 	{Opt_nouser_xattr, "nouser_xattr"},
1717 	{Opt_acl, "acl"},
1718 	{Opt_noacl, "noacl"},
1719 	{Opt_noload, "norecovery"},
1720 	{Opt_noload, "noload"},
1721 	{Opt_removed, "nobh"},
1722 	{Opt_removed, "bh"},
1723 	{Opt_commit, "commit=%u"},
1724 	{Opt_min_batch_time, "min_batch_time=%u"},
1725 	{Opt_max_batch_time, "max_batch_time=%u"},
1726 	{Opt_journal_dev, "journal_dev=%u"},
1727 	{Opt_journal_path, "journal_path=%s"},
1728 	{Opt_journal_checksum, "journal_checksum"},
1729 	{Opt_nojournal_checksum, "nojournal_checksum"},
1730 	{Opt_journal_async_commit, "journal_async_commit"},
1731 	{Opt_abort, "abort"},
1732 	{Opt_data_journal, "data=journal"},
1733 	{Opt_data_ordered, "data=ordered"},
1734 	{Opt_data_writeback, "data=writeback"},
1735 	{Opt_data_err_abort, "data_err=abort"},
1736 	{Opt_data_err_ignore, "data_err=ignore"},
1737 	{Opt_offusrjquota, "usrjquota="},
1738 	{Opt_usrjquota, "usrjquota=%s"},
1739 	{Opt_offgrpjquota, "grpjquota="},
1740 	{Opt_grpjquota, "grpjquota=%s"},
1741 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1742 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1743 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1744 	{Opt_grpquota, "grpquota"},
1745 	{Opt_noquota, "noquota"},
1746 	{Opt_quota, "quota"},
1747 	{Opt_usrquota, "usrquota"},
1748 	{Opt_prjquota, "prjquota"},
1749 	{Opt_barrier, "barrier=%u"},
1750 	{Opt_barrier, "barrier"},
1751 	{Opt_nobarrier, "nobarrier"},
1752 	{Opt_i_version, "i_version"},
1753 	{Opt_dax, "dax"},
1754 	{Opt_dax_always, "dax=always"},
1755 	{Opt_dax_inode, "dax=inode"},
1756 	{Opt_dax_never, "dax=never"},
1757 	{Opt_stripe, "stripe=%u"},
1758 	{Opt_delalloc, "delalloc"},
1759 	{Opt_warn_on_error, "warn_on_error"},
1760 	{Opt_nowarn_on_error, "nowarn_on_error"},
1761 	{Opt_lazytime, "lazytime"},
1762 	{Opt_nolazytime, "nolazytime"},
1763 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1764 	{Opt_nodelalloc, "nodelalloc"},
1765 	{Opt_removed, "mblk_io_submit"},
1766 	{Opt_removed, "nomblk_io_submit"},
1767 	{Opt_block_validity, "block_validity"},
1768 	{Opt_noblock_validity, "noblock_validity"},
1769 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1770 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1771 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1772 	{Opt_auto_da_alloc, "auto_da_alloc"},
1773 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1774 	{Opt_dioread_nolock, "dioread_nolock"},
1775 	{Opt_dioread_lock, "nodioread_nolock"},
1776 	{Opt_dioread_lock, "dioread_lock"},
1777 	{Opt_discard, "discard"},
1778 	{Opt_nodiscard, "nodiscard"},
1779 	{Opt_init_itable, "init_itable=%u"},
1780 	{Opt_init_itable, "init_itable"},
1781 	{Opt_noinit_itable, "noinit_itable"},
1782 #ifdef CONFIG_EXT4_DEBUG
1783 	{Opt_fc_debug_force, "fc_debug_force"},
1784 	{Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
1785 #endif
1786 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1787 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1788 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1789 	{Opt_inlinecrypt, "inlinecrypt"},
1790 	{Opt_nombcache, "nombcache"},
1791 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1792 	{Opt_removed, "prefetch_block_bitmaps"},
1793 	{Opt_no_prefetch_block_bitmaps, "no_prefetch_block_bitmaps"},
1794 	{Opt_mb_optimize_scan, "mb_optimize_scan=%d"},
1795 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1796 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1797 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1798 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1799 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1800 	{Opt_err, NULL},
1801 };
1802 
1803 static ext4_fsblk_t get_sb_block(void **data)
1804 {
1805 	ext4_fsblk_t	sb_block;
1806 	char		*options = (char *) *data;
1807 
1808 	if (!options || strncmp(options, "sb=", 3) != 0)
1809 		return 1;	/* Default location */
1810 
1811 	options += 3;
1812 	/* TODO: use simple_strtoll with >32bit ext4 */
1813 	sb_block = simple_strtoul(options, &options, 0);
1814 	if (*options && *options != ',') {
1815 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1816 		       (char *) *data);
1817 		return 1;
1818 	}
1819 	if (*options == ',')
1820 		options++;
1821 	*data = (void *) options;
1822 
1823 	return sb_block;
1824 }
1825 
1826 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1827 #define DEFAULT_MB_OPTIMIZE_SCAN	(-1)
1828 
1829 static const char deprecated_msg[] =
1830 	"Mount option \"%s\" will be removed by %s\n"
1831 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1832 
1833 #ifdef CONFIG_QUOTA
1834 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1835 {
1836 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1837 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1838 	int ret = -1;
1839 
1840 	if (sb_any_quota_loaded(sb) && !old_qname) {
1841 		ext4_msg(sb, KERN_ERR,
1842 			"Cannot change journaled "
1843 			"quota options when quota turned on");
1844 		return -1;
1845 	}
1846 	if (ext4_has_feature_quota(sb)) {
1847 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1848 			 "ignored when QUOTA feature is enabled");
1849 		return 1;
1850 	}
1851 	qname = match_strdup(args);
1852 	if (!qname) {
1853 		ext4_msg(sb, KERN_ERR,
1854 			"Not enough memory for storing quotafile name");
1855 		return -1;
1856 	}
1857 	if (old_qname) {
1858 		if (strcmp(old_qname, qname) == 0)
1859 			ret = 1;
1860 		else
1861 			ext4_msg(sb, KERN_ERR,
1862 				 "%s quota file already specified",
1863 				 QTYPE2NAME(qtype));
1864 		goto errout;
1865 	}
1866 	if (strchr(qname, '/')) {
1867 		ext4_msg(sb, KERN_ERR,
1868 			"quotafile must be on filesystem root");
1869 		goto errout;
1870 	}
1871 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1872 	set_opt(sb, QUOTA);
1873 	return 1;
1874 errout:
1875 	kfree(qname);
1876 	return ret;
1877 }
1878 
1879 static int clear_qf_name(struct super_block *sb, int qtype)
1880 {
1881 
1882 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1883 	char *old_qname = get_qf_name(sb, sbi, qtype);
1884 
1885 	if (sb_any_quota_loaded(sb) && old_qname) {
1886 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1887 			" when quota turned on");
1888 		return -1;
1889 	}
1890 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1891 	synchronize_rcu();
1892 	kfree(old_qname);
1893 	return 1;
1894 }
1895 #endif
1896 
1897 #define MOPT_SET	0x0001
1898 #define MOPT_CLEAR	0x0002
1899 #define MOPT_NOSUPPORT	0x0004
1900 #define MOPT_EXPLICIT	0x0008
1901 #define MOPT_CLEAR_ERR	0x0010
1902 #define MOPT_GTE0	0x0020
1903 #ifdef CONFIG_QUOTA
1904 #define MOPT_Q		0
1905 #define MOPT_QFMT	0x0040
1906 #else
1907 #define MOPT_Q		MOPT_NOSUPPORT
1908 #define MOPT_QFMT	MOPT_NOSUPPORT
1909 #endif
1910 #define MOPT_DATAJ	0x0080
1911 #define MOPT_NO_EXT2	0x0100
1912 #define MOPT_NO_EXT3	0x0200
1913 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1914 #define MOPT_STRING	0x0400
1915 #define MOPT_SKIP	0x0800
1916 #define	MOPT_2		0x1000
1917 
1918 static const struct mount_opts {
1919 	int	token;
1920 	int	mount_opt;
1921 	int	flags;
1922 } ext4_mount_opts[] = {
1923 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1924 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1925 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1926 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1927 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1928 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1929 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1930 	 MOPT_EXT4_ONLY | MOPT_SET},
1931 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1932 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1933 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1934 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1935 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1936 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1937 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1938 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1939 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1940 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1941 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1942 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1943 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1944 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1945 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1946 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1947 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1948 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1949 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1950 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1951 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1952 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1953 	 MOPT_NO_EXT2},
1954 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1955 	 MOPT_NO_EXT2},
1956 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1957 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1958 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1959 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1960 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1961 	{Opt_commit, 0, MOPT_GTE0},
1962 	{Opt_max_batch_time, 0, MOPT_GTE0},
1963 	{Opt_min_batch_time, 0, MOPT_GTE0},
1964 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1965 	{Opt_init_itable, 0, MOPT_GTE0},
1966 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1967 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1968 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1969 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1970 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1971 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1972 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1973 	{Opt_stripe, 0, MOPT_GTE0},
1974 	{Opt_resuid, 0, MOPT_GTE0},
1975 	{Opt_resgid, 0, MOPT_GTE0},
1976 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1977 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1978 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1979 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1980 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1981 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1982 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1983 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1984 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1985 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1986 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1987 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1988 #else
1989 	{Opt_acl, 0, MOPT_NOSUPPORT},
1990 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1991 #endif
1992 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1993 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1994 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1995 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1996 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1997 							MOPT_SET | MOPT_Q},
1998 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1999 							MOPT_SET | MOPT_Q},
2000 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
2001 							MOPT_SET | MOPT_Q},
2002 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2003 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
2004 							MOPT_CLEAR | MOPT_Q},
2005 	{Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
2006 	{Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
2007 	{Opt_offusrjquota, 0, MOPT_Q},
2008 	{Opt_offgrpjquota, 0, MOPT_Q},
2009 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
2010 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
2011 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
2012 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
2013 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
2014 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
2015 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
2016 	 MOPT_SET},
2017 	{Opt_mb_optimize_scan, EXT4_MOUNT2_MB_OPTIMIZE_SCAN, MOPT_GTE0},
2018 #ifdef CONFIG_EXT4_DEBUG
2019 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2020 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
2021 	{Opt_fc_debug_max_replay, 0, MOPT_GTE0},
2022 #endif
2023 	{Opt_err, 0, 0}
2024 };
2025 
2026 #ifdef CONFIG_UNICODE
2027 static const struct ext4_sb_encodings {
2028 	__u16 magic;
2029 	char *name;
2030 	char *version;
2031 } ext4_sb_encoding_map[] = {
2032 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
2033 };
2034 
2035 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
2036 				 const struct ext4_sb_encodings **encoding,
2037 				 __u16 *flags)
2038 {
2039 	__u16 magic = le16_to_cpu(es->s_encoding);
2040 	int i;
2041 
2042 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
2043 		if (magic == ext4_sb_encoding_map[i].magic)
2044 			break;
2045 
2046 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
2047 		return -EINVAL;
2048 
2049 	*encoding = &ext4_sb_encoding_map[i];
2050 	*flags = le16_to_cpu(es->s_encoding_flags);
2051 
2052 	return 0;
2053 }
2054 #endif
2055 
2056 static int ext4_set_test_dummy_encryption(struct super_block *sb,
2057 					  const char *opt,
2058 					  const substring_t *arg,
2059 					  bool is_remount)
2060 {
2061 #ifdef CONFIG_FS_ENCRYPTION
2062 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2063 	int err;
2064 
2065 	/*
2066 	 * This mount option is just for testing, and it's not worthwhile to
2067 	 * implement the extra complexity (e.g. RCU protection) that would be
2068 	 * needed to allow it to be set or changed during remount.  We do allow
2069 	 * it to be specified during remount, but only if there is no change.
2070 	 */
2071 	if (is_remount && !sbi->s_dummy_enc_policy.policy) {
2072 		ext4_msg(sb, KERN_WARNING,
2073 			 "Can't set test_dummy_encryption on remount");
2074 		return -1;
2075 	}
2076 	err = fscrypt_set_test_dummy_encryption(sb, arg->from,
2077 						&sbi->s_dummy_enc_policy);
2078 	if (err) {
2079 		if (err == -EEXIST)
2080 			ext4_msg(sb, KERN_WARNING,
2081 				 "Can't change test_dummy_encryption on remount");
2082 		else if (err == -EINVAL)
2083 			ext4_msg(sb, KERN_WARNING,
2084 				 "Value of option \"%s\" is unrecognized", opt);
2085 		else
2086 			ext4_msg(sb, KERN_WARNING,
2087 				 "Error processing option \"%s\" [%d]",
2088 				 opt, err);
2089 		return -1;
2090 	}
2091 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2092 #else
2093 	ext4_msg(sb, KERN_WARNING,
2094 		 "Test dummy encryption mount option ignored");
2095 #endif
2096 	return 1;
2097 }
2098 
2099 struct ext4_parsed_options {
2100 	unsigned long journal_devnum;
2101 	unsigned int journal_ioprio;
2102 	int mb_optimize_scan;
2103 };
2104 
2105 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
2106 			    substring_t *args, struct ext4_parsed_options *parsed_opts,
2107 			    int is_remount)
2108 {
2109 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2110 	const struct mount_opts *m;
2111 	kuid_t uid;
2112 	kgid_t gid;
2113 	int arg = 0;
2114 
2115 #ifdef CONFIG_QUOTA
2116 	if (token == Opt_usrjquota)
2117 		return set_qf_name(sb, USRQUOTA, &args[0]);
2118 	else if (token == Opt_grpjquota)
2119 		return set_qf_name(sb, GRPQUOTA, &args[0]);
2120 	else if (token == Opt_offusrjquota)
2121 		return clear_qf_name(sb, USRQUOTA);
2122 	else if (token == Opt_offgrpjquota)
2123 		return clear_qf_name(sb, GRPQUOTA);
2124 #endif
2125 	switch (token) {
2126 	case Opt_noacl:
2127 	case Opt_nouser_xattr:
2128 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
2129 		break;
2130 	case Opt_sb:
2131 		return 1;	/* handled by get_sb_block() */
2132 	case Opt_removed:
2133 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
2134 		return 1;
2135 	case Opt_abort:
2136 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
2137 		return 1;
2138 	case Opt_i_version:
2139 		sb->s_flags |= SB_I_VERSION;
2140 		return 1;
2141 	case Opt_lazytime:
2142 		sb->s_flags |= SB_LAZYTIME;
2143 		return 1;
2144 	case Opt_nolazytime:
2145 		sb->s_flags &= ~SB_LAZYTIME;
2146 		return 1;
2147 	case Opt_inlinecrypt:
2148 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2149 		sb->s_flags |= SB_INLINECRYPT;
2150 #else
2151 		ext4_msg(sb, KERN_ERR, "inline encryption not supported");
2152 #endif
2153 		return 1;
2154 	}
2155 
2156 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2157 		if (token == m->token)
2158 			break;
2159 
2160 	if (m->token == Opt_err) {
2161 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
2162 			 "or missing value", opt);
2163 		return -1;
2164 	}
2165 
2166 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2167 		ext4_msg(sb, KERN_ERR,
2168 			 "Mount option \"%s\" incompatible with ext2", opt);
2169 		return -1;
2170 	}
2171 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2172 		ext4_msg(sb, KERN_ERR,
2173 			 "Mount option \"%s\" incompatible with ext3", opt);
2174 		return -1;
2175 	}
2176 
2177 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
2178 		return -1;
2179 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
2180 		return -1;
2181 	if (m->flags & MOPT_EXPLICIT) {
2182 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2183 			set_opt2(sb, EXPLICIT_DELALLOC);
2184 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2185 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
2186 		} else
2187 			return -1;
2188 	}
2189 	if (m->flags & MOPT_CLEAR_ERR)
2190 		clear_opt(sb, ERRORS_MASK);
2191 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
2192 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
2193 			 "options when quota turned on");
2194 		return -1;
2195 	}
2196 
2197 	if (m->flags & MOPT_NOSUPPORT) {
2198 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
2199 	} else if (token == Opt_commit) {
2200 		if (arg == 0)
2201 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
2202 		else if (arg > INT_MAX / HZ) {
2203 			ext4_msg(sb, KERN_ERR,
2204 				 "Invalid commit interval %d, "
2205 				 "must be smaller than %d",
2206 				 arg, INT_MAX / HZ);
2207 			return -1;
2208 		}
2209 		sbi->s_commit_interval = HZ * arg;
2210 	} else if (token == Opt_debug_want_extra_isize) {
2211 		if ((arg & 1) ||
2212 		    (arg < 4) ||
2213 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2214 			ext4_msg(sb, KERN_ERR,
2215 				 "Invalid want_extra_isize %d", arg);
2216 			return -1;
2217 		}
2218 		sbi->s_want_extra_isize = arg;
2219 	} else if (token == Opt_max_batch_time) {
2220 		sbi->s_max_batch_time = arg;
2221 	} else if (token == Opt_min_batch_time) {
2222 		sbi->s_min_batch_time = arg;
2223 	} else if (token == Opt_inode_readahead_blks) {
2224 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2225 			ext4_msg(sb, KERN_ERR,
2226 				 "EXT4-fs: inode_readahead_blks must be "
2227 				 "0 or a power of 2 smaller than 2^31");
2228 			return -1;
2229 		}
2230 		sbi->s_inode_readahead_blks = arg;
2231 	} else if (token == Opt_init_itable) {
2232 		set_opt(sb, INIT_INODE_TABLE);
2233 		if (!args->from)
2234 			arg = EXT4_DEF_LI_WAIT_MULT;
2235 		sbi->s_li_wait_mult = arg;
2236 	} else if (token == Opt_max_dir_size_kb) {
2237 		sbi->s_max_dir_size_kb = arg;
2238 #ifdef CONFIG_EXT4_DEBUG
2239 	} else if (token == Opt_fc_debug_max_replay) {
2240 		sbi->s_fc_debug_max_replay = arg;
2241 #endif
2242 	} else if (token == Opt_stripe) {
2243 		sbi->s_stripe = arg;
2244 	} else if (token == Opt_resuid) {
2245 		uid = make_kuid(current_user_ns(), arg);
2246 		if (!uid_valid(uid)) {
2247 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2248 			return -1;
2249 		}
2250 		sbi->s_resuid = uid;
2251 	} else if (token == Opt_resgid) {
2252 		gid = make_kgid(current_user_ns(), arg);
2253 		if (!gid_valid(gid)) {
2254 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2255 			return -1;
2256 		}
2257 		sbi->s_resgid = gid;
2258 	} else if (token == Opt_journal_dev) {
2259 		if (is_remount) {
2260 			ext4_msg(sb, KERN_ERR,
2261 				 "Cannot specify journal on remount");
2262 			return -1;
2263 		}
2264 		parsed_opts->journal_devnum = arg;
2265 	} else if (token == Opt_journal_path) {
2266 		char *journal_path;
2267 		struct inode *journal_inode;
2268 		struct path path;
2269 		int error;
2270 
2271 		if (is_remount) {
2272 			ext4_msg(sb, KERN_ERR,
2273 				 "Cannot specify journal on remount");
2274 			return -1;
2275 		}
2276 		journal_path = match_strdup(&args[0]);
2277 		if (!journal_path) {
2278 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2279 				"journal device string");
2280 			return -1;
2281 		}
2282 
2283 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2284 		if (error) {
2285 			ext4_msg(sb, KERN_ERR, "error: could not find "
2286 				"journal device path: error %d", error);
2287 			kfree(journal_path);
2288 			return -1;
2289 		}
2290 
2291 		journal_inode = d_inode(path.dentry);
2292 		if (!S_ISBLK(journal_inode->i_mode)) {
2293 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2294 				"is not a block device", journal_path);
2295 			path_put(&path);
2296 			kfree(journal_path);
2297 			return -1;
2298 		}
2299 
2300 		parsed_opts->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2301 		path_put(&path);
2302 		kfree(journal_path);
2303 	} else if (token == Opt_journal_ioprio) {
2304 		if (arg > 7) {
2305 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2306 				 " (must be 0-7)");
2307 			return -1;
2308 		}
2309 		parsed_opts->journal_ioprio =
2310 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2311 	} else if (token == Opt_test_dummy_encryption) {
2312 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2313 						      is_remount);
2314 	} else if (m->flags & MOPT_DATAJ) {
2315 		if (is_remount) {
2316 			if (!sbi->s_journal)
2317 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2318 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2319 				ext4_msg(sb, KERN_ERR,
2320 					 "Cannot change data mode on remount");
2321 				return -1;
2322 			}
2323 		} else {
2324 			clear_opt(sb, DATA_FLAGS);
2325 			sbi->s_mount_opt |= m->mount_opt;
2326 		}
2327 #ifdef CONFIG_QUOTA
2328 	} else if (m->flags & MOPT_QFMT) {
2329 		if (sb_any_quota_loaded(sb) &&
2330 		    sbi->s_jquota_fmt != m->mount_opt) {
2331 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2332 				 "quota options when quota turned on");
2333 			return -1;
2334 		}
2335 		if (ext4_has_feature_quota(sb)) {
2336 			ext4_msg(sb, KERN_INFO,
2337 				 "Quota format mount options ignored "
2338 				 "when QUOTA feature is enabled");
2339 			return 1;
2340 		}
2341 		sbi->s_jquota_fmt = m->mount_opt;
2342 #endif
2343 	} else if (token == Opt_dax || token == Opt_dax_always ||
2344 		   token == Opt_dax_inode || token == Opt_dax_never) {
2345 #ifdef CONFIG_FS_DAX
2346 		switch (token) {
2347 		case Opt_dax:
2348 		case Opt_dax_always:
2349 			if (is_remount &&
2350 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2351 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2352 			fail_dax_change_remount:
2353 				ext4_msg(sb, KERN_ERR, "can't change "
2354 					 "dax mount option while remounting");
2355 				return -1;
2356 			}
2357 			if (is_remount &&
2358 			    (test_opt(sb, DATA_FLAGS) ==
2359 			     EXT4_MOUNT_JOURNAL_DATA)) {
2360 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2361 					     "both data=journal and dax");
2362 				    return -1;
2363 			}
2364 			ext4_msg(sb, KERN_WARNING,
2365 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2366 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2367 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2368 			break;
2369 		case Opt_dax_never:
2370 			if (is_remount &&
2371 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2372 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2373 				goto fail_dax_change_remount;
2374 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2375 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2376 			break;
2377 		case Opt_dax_inode:
2378 			if (is_remount &&
2379 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2380 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2381 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2382 				goto fail_dax_change_remount;
2383 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2384 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2385 			/* Strictly for printing options */
2386 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2387 			break;
2388 		}
2389 #else
2390 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2391 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2392 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2393 		return -1;
2394 #endif
2395 	} else if (token == Opt_data_err_abort) {
2396 		sbi->s_mount_opt |= m->mount_opt;
2397 	} else if (token == Opt_data_err_ignore) {
2398 		sbi->s_mount_opt &= ~m->mount_opt;
2399 	} else if (token == Opt_mb_optimize_scan) {
2400 		if (arg != 0 && arg != 1) {
2401 			ext4_msg(sb, KERN_WARNING,
2402 				 "mb_optimize_scan should be set to 0 or 1.");
2403 			return -1;
2404 		}
2405 		parsed_opts->mb_optimize_scan = arg;
2406 	} else {
2407 		if (!args->from)
2408 			arg = 1;
2409 		if (m->flags & MOPT_CLEAR)
2410 			arg = !arg;
2411 		else if (unlikely(!(m->flags & MOPT_SET))) {
2412 			ext4_msg(sb, KERN_WARNING,
2413 				 "buggy handling of option %s", opt);
2414 			WARN_ON(1);
2415 			return -1;
2416 		}
2417 		if (m->flags & MOPT_2) {
2418 			if (arg != 0)
2419 				sbi->s_mount_opt2 |= m->mount_opt;
2420 			else
2421 				sbi->s_mount_opt2 &= ~m->mount_opt;
2422 		} else {
2423 			if (arg != 0)
2424 				sbi->s_mount_opt |= m->mount_opt;
2425 			else
2426 				sbi->s_mount_opt &= ~m->mount_opt;
2427 		}
2428 	}
2429 	return 1;
2430 }
2431 
2432 static int parse_options(char *options, struct super_block *sb,
2433 			 struct ext4_parsed_options *ret_opts,
2434 			 int is_remount)
2435 {
2436 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2437 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2438 	substring_t args[MAX_OPT_ARGS];
2439 	int token;
2440 
2441 	if (!options)
2442 		return 1;
2443 
2444 	while ((p = strsep(&options, ",")) != NULL) {
2445 		if (!*p)
2446 			continue;
2447 		/*
2448 		 * Initialize args struct so we know whether arg was
2449 		 * found; some options take optional arguments.
2450 		 */
2451 		args[0].to = args[0].from = NULL;
2452 		token = match_token(p, tokens, args);
2453 		if (handle_mount_opt(sb, p, token, args, ret_opts,
2454 				     is_remount) < 0)
2455 			return 0;
2456 	}
2457 #ifdef CONFIG_QUOTA
2458 	/*
2459 	 * We do the test below only for project quotas. 'usrquota' and
2460 	 * 'grpquota' mount options are allowed even without quota feature
2461 	 * to support legacy quotas in quota files.
2462 	 */
2463 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2464 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2465 			 "Cannot enable project quota enforcement.");
2466 		return 0;
2467 	}
2468 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2469 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2470 	if (usr_qf_name || grp_qf_name) {
2471 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2472 			clear_opt(sb, USRQUOTA);
2473 
2474 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2475 			clear_opt(sb, GRPQUOTA);
2476 
2477 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2478 			ext4_msg(sb, KERN_ERR, "old and new quota "
2479 					"format mixing");
2480 			return 0;
2481 		}
2482 
2483 		if (!sbi->s_jquota_fmt) {
2484 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2485 					"not specified");
2486 			return 0;
2487 		}
2488 	}
2489 #endif
2490 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2491 		int blocksize =
2492 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2493 		if (blocksize < PAGE_SIZE)
2494 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2495 				 "experimental mount option 'dioread_nolock' "
2496 				 "for blocksize < PAGE_SIZE");
2497 	}
2498 	return 1;
2499 }
2500 
2501 static inline void ext4_show_quota_options(struct seq_file *seq,
2502 					   struct super_block *sb)
2503 {
2504 #if defined(CONFIG_QUOTA)
2505 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2506 	char *usr_qf_name, *grp_qf_name;
2507 
2508 	if (sbi->s_jquota_fmt) {
2509 		char *fmtname = "";
2510 
2511 		switch (sbi->s_jquota_fmt) {
2512 		case QFMT_VFS_OLD:
2513 			fmtname = "vfsold";
2514 			break;
2515 		case QFMT_VFS_V0:
2516 			fmtname = "vfsv0";
2517 			break;
2518 		case QFMT_VFS_V1:
2519 			fmtname = "vfsv1";
2520 			break;
2521 		}
2522 		seq_printf(seq, ",jqfmt=%s", fmtname);
2523 	}
2524 
2525 	rcu_read_lock();
2526 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2527 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2528 	if (usr_qf_name)
2529 		seq_show_option(seq, "usrjquota", usr_qf_name);
2530 	if (grp_qf_name)
2531 		seq_show_option(seq, "grpjquota", grp_qf_name);
2532 	rcu_read_unlock();
2533 #endif
2534 }
2535 
2536 static const char *token2str(int token)
2537 {
2538 	const struct match_token *t;
2539 
2540 	for (t = tokens; t->token != Opt_err; t++)
2541 		if (t->token == token && !strchr(t->pattern, '='))
2542 			break;
2543 	return t->pattern;
2544 }
2545 
2546 /*
2547  * Show an option if
2548  *  - it's set to a non-default value OR
2549  *  - if the per-sb default is different from the global default
2550  */
2551 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2552 			      int nodefs)
2553 {
2554 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2555 	struct ext4_super_block *es = sbi->s_es;
2556 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2557 	const struct mount_opts *m;
2558 	char sep = nodefs ? '\n' : ',';
2559 
2560 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2561 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2562 
2563 	if (sbi->s_sb_block != 1)
2564 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2565 
2566 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2567 		int want_set = m->flags & MOPT_SET;
2568 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2569 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2570 			continue;
2571 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2572 			continue; /* skip if same as the default */
2573 		if ((want_set &&
2574 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2575 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2576 			continue; /* select Opt_noFoo vs Opt_Foo */
2577 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2578 	}
2579 
2580 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2581 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2582 		SEQ_OPTS_PRINT("resuid=%u",
2583 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2584 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2585 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2586 		SEQ_OPTS_PRINT("resgid=%u",
2587 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2588 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2589 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2590 		SEQ_OPTS_PUTS("errors=remount-ro");
2591 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2592 		SEQ_OPTS_PUTS("errors=continue");
2593 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2594 		SEQ_OPTS_PUTS("errors=panic");
2595 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2596 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2597 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2598 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2599 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2600 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2601 	if (sb->s_flags & SB_I_VERSION)
2602 		SEQ_OPTS_PUTS("i_version");
2603 	if (nodefs || sbi->s_stripe)
2604 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2605 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2606 			(sbi->s_mount_opt ^ def_mount_opt)) {
2607 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2608 			SEQ_OPTS_PUTS("data=journal");
2609 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2610 			SEQ_OPTS_PUTS("data=ordered");
2611 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2612 			SEQ_OPTS_PUTS("data=writeback");
2613 	}
2614 	if (nodefs ||
2615 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2616 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2617 			       sbi->s_inode_readahead_blks);
2618 
2619 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2620 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2621 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2622 	if (nodefs || sbi->s_max_dir_size_kb)
2623 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2624 	if (test_opt(sb, DATA_ERR_ABORT))
2625 		SEQ_OPTS_PUTS("data_err=abort");
2626 
2627 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2628 
2629 	if (sb->s_flags & SB_INLINECRYPT)
2630 		SEQ_OPTS_PUTS("inlinecrypt");
2631 
2632 	if (test_opt(sb, DAX_ALWAYS)) {
2633 		if (IS_EXT2_SB(sb))
2634 			SEQ_OPTS_PUTS("dax");
2635 		else
2636 			SEQ_OPTS_PUTS("dax=always");
2637 	} else if (test_opt2(sb, DAX_NEVER)) {
2638 		SEQ_OPTS_PUTS("dax=never");
2639 	} else if (test_opt2(sb, DAX_INODE)) {
2640 		SEQ_OPTS_PUTS("dax=inode");
2641 	}
2642 	ext4_show_quota_options(seq, sb);
2643 	return 0;
2644 }
2645 
2646 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2647 {
2648 	return _ext4_show_options(seq, root->d_sb, 0);
2649 }
2650 
2651 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2652 {
2653 	struct super_block *sb = seq->private;
2654 	int rc;
2655 
2656 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2657 	rc = _ext4_show_options(seq, sb, 1);
2658 	seq_puts(seq, "\n");
2659 	return rc;
2660 }
2661 
2662 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2663 			    int read_only)
2664 {
2665 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2666 	int err = 0;
2667 
2668 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2669 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2670 			 "forcing read-only mode");
2671 		err = -EROFS;
2672 		goto done;
2673 	}
2674 	if (read_only)
2675 		goto done;
2676 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2677 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2678 			 "running e2fsck is recommended");
2679 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2680 		ext4_msg(sb, KERN_WARNING,
2681 			 "warning: mounting fs with errors, "
2682 			 "running e2fsck is recommended");
2683 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2684 		 le16_to_cpu(es->s_mnt_count) >=
2685 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2686 		ext4_msg(sb, KERN_WARNING,
2687 			 "warning: maximal mount count reached, "
2688 			 "running e2fsck is recommended");
2689 	else if (le32_to_cpu(es->s_checkinterval) &&
2690 		 (ext4_get_tstamp(es, s_lastcheck) +
2691 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2692 		ext4_msg(sb, KERN_WARNING,
2693 			 "warning: checktime reached, "
2694 			 "running e2fsck is recommended");
2695 	if (!sbi->s_journal)
2696 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2697 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2698 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2699 	le16_add_cpu(&es->s_mnt_count, 1);
2700 	ext4_update_tstamp(es, s_mtime);
2701 	if (sbi->s_journal)
2702 		ext4_set_feature_journal_needs_recovery(sb);
2703 
2704 	err = ext4_commit_super(sb);
2705 done:
2706 	if (test_opt(sb, DEBUG))
2707 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2708 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2709 			sb->s_blocksize,
2710 			sbi->s_groups_count,
2711 			EXT4_BLOCKS_PER_GROUP(sb),
2712 			EXT4_INODES_PER_GROUP(sb),
2713 			sbi->s_mount_opt, sbi->s_mount_opt2);
2714 
2715 	cleancache_init_fs(sb);
2716 	return err;
2717 }
2718 
2719 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2720 {
2721 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2722 	struct flex_groups **old_groups, **new_groups;
2723 	int size, i, j;
2724 
2725 	if (!sbi->s_log_groups_per_flex)
2726 		return 0;
2727 
2728 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2729 	if (size <= sbi->s_flex_groups_allocated)
2730 		return 0;
2731 
2732 	new_groups = kvzalloc(roundup_pow_of_two(size *
2733 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2734 	if (!new_groups) {
2735 		ext4_msg(sb, KERN_ERR,
2736 			 "not enough memory for %d flex group pointers", size);
2737 		return -ENOMEM;
2738 	}
2739 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2740 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2741 					 sizeof(struct flex_groups)),
2742 					 GFP_KERNEL);
2743 		if (!new_groups[i]) {
2744 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2745 				kvfree(new_groups[j]);
2746 			kvfree(new_groups);
2747 			ext4_msg(sb, KERN_ERR,
2748 				 "not enough memory for %d flex groups", size);
2749 			return -ENOMEM;
2750 		}
2751 	}
2752 	rcu_read_lock();
2753 	old_groups = rcu_dereference(sbi->s_flex_groups);
2754 	if (old_groups)
2755 		memcpy(new_groups, old_groups,
2756 		       (sbi->s_flex_groups_allocated *
2757 			sizeof(struct flex_groups *)));
2758 	rcu_read_unlock();
2759 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2760 	sbi->s_flex_groups_allocated = size;
2761 	if (old_groups)
2762 		ext4_kvfree_array_rcu(old_groups);
2763 	return 0;
2764 }
2765 
2766 static int ext4_fill_flex_info(struct super_block *sb)
2767 {
2768 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2769 	struct ext4_group_desc *gdp = NULL;
2770 	struct flex_groups *fg;
2771 	ext4_group_t flex_group;
2772 	int i, err;
2773 
2774 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2775 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2776 		sbi->s_log_groups_per_flex = 0;
2777 		return 1;
2778 	}
2779 
2780 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2781 	if (err)
2782 		goto failed;
2783 
2784 	for (i = 0; i < sbi->s_groups_count; i++) {
2785 		gdp = ext4_get_group_desc(sb, i, NULL);
2786 
2787 		flex_group = ext4_flex_group(sbi, i);
2788 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2789 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2790 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2791 			     &fg->free_clusters);
2792 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2793 	}
2794 
2795 	return 1;
2796 failed:
2797 	return 0;
2798 }
2799 
2800 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2801 				   struct ext4_group_desc *gdp)
2802 {
2803 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2804 	__u16 crc = 0;
2805 	__le32 le_group = cpu_to_le32(block_group);
2806 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2807 
2808 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2809 		/* Use new metadata_csum algorithm */
2810 		__u32 csum32;
2811 		__u16 dummy_csum = 0;
2812 
2813 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2814 				     sizeof(le_group));
2815 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2816 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2817 				     sizeof(dummy_csum));
2818 		offset += sizeof(dummy_csum);
2819 		if (offset < sbi->s_desc_size)
2820 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2821 					     sbi->s_desc_size - offset);
2822 
2823 		crc = csum32 & 0xFFFF;
2824 		goto out;
2825 	}
2826 
2827 	/* old crc16 code */
2828 	if (!ext4_has_feature_gdt_csum(sb))
2829 		return 0;
2830 
2831 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2832 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2833 	crc = crc16(crc, (__u8 *)gdp, offset);
2834 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2835 	/* for checksum of struct ext4_group_desc do the rest...*/
2836 	if (ext4_has_feature_64bit(sb) &&
2837 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2838 		crc = crc16(crc, (__u8 *)gdp + offset,
2839 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2840 				offset);
2841 
2842 out:
2843 	return cpu_to_le16(crc);
2844 }
2845 
2846 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2847 				struct ext4_group_desc *gdp)
2848 {
2849 	if (ext4_has_group_desc_csum(sb) &&
2850 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2851 		return 0;
2852 
2853 	return 1;
2854 }
2855 
2856 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2857 			      struct ext4_group_desc *gdp)
2858 {
2859 	if (!ext4_has_group_desc_csum(sb))
2860 		return;
2861 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2862 }
2863 
2864 /* Called at mount-time, super-block is locked */
2865 static int ext4_check_descriptors(struct super_block *sb,
2866 				  ext4_fsblk_t sb_block,
2867 				  ext4_group_t *first_not_zeroed)
2868 {
2869 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2870 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2871 	ext4_fsblk_t last_block;
2872 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2873 	ext4_fsblk_t block_bitmap;
2874 	ext4_fsblk_t inode_bitmap;
2875 	ext4_fsblk_t inode_table;
2876 	int flexbg_flag = 0;
2877 	ext4_group_t i, grp = sbi->s_groups_count;
2878 
2879 	if (ext4_has_feature_flex_bg(sb))
2880 		flexbg_flag = 1;
2881 
2882 	ext4_debug("Checking group descriptors");
2883 
2884 	for (i = 0; i < sbi->s_groups_count; i++) {
2885 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2886 
2887 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2888 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2889 		else
2890 			last_block = first_block +
2891 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2892 
2893 		if ((grp == sbi->s_groups_count) &&
2894 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2895 			grp = i;
2896 
2897 		block_bitmap = ext4_block_bitmap(sb, gdp);
2898 		if (block_bitmap == sb_block) {
2899 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2900 				 "Block bitmap for group %u overlaps "
2901 				 "superblock", i);
2902 			if (!sb_rdonly(sb))
2903 				return 0;
2904 		}
2905 		if (block_bitmap >= sb_block + 1 &&
2906 		    block_bitmap <= last_bg_block) {
2907 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2908 				 "Block bitmap for group %u overlaps "
2909 				 "block group descriptors", i);
2910 			if (!sb_rdonly(sb))
2911 				return 0;
2912 		}
2913 		if (block_bitmap < first_block || block_bitmap > last_block) {
2914 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2915 			       "Block bitmap for group %u not in group "
2916 			       "(block %llu)!", i, block_bitmap);
2917 			return 0;
2918 		}
2919 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2920 		if (inode_bitmap == sb_block) {
2921 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2922 				 "Inode bitmap for group %u overlaps "
2923 				 "superblock", i);
2924 			if (!sb_rdonly(sb))
2925 				return 0;
2926 		}
2927 		if (inode_bitmap >= sb_block + 1 &&
2928 		    inode_bitmap <= last_bg_block) {
2929 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2930 				 "Inode bitmap for group %u overlaps "
2931 				 "block group descriptors", i);
2932 			if (!sb_rdonly(sb))
2933 				return 0;
2934 		}
2935 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2936 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2937 			       "Inode bitmap for group %u not in group "
2938 			       "(block %llu)!", i, inode_bitmap);
2939 			return 0;
2940 		}
2941 		inode_table = ext4_inode_table(sb, gdp);
2942 		if (inode_table == sb_block) {
2943 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2944 				 "Inode table for group %u overlaps "
2945 				 "superblock", i);
2946 			if (!sb_rdonly(sb))
2947 				return 0;
2948 		}
2949 		if (inode_table >= sb_block + 1 &&
2950 		    inode_table <= last_bg_block) {
2951 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2952 				 "Inode table for group %u overlaps "
2953 				 "block group descriptors", i);
2954 			if (!sb_rdonly(sb))
2955 				return 0;
2956 		}
2957 		if (inode_table < first_block ||
2958 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2959 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2960 			       "Inode table for group %u not in group "
2961 			       "(block %llu)!", i, inode_table);
2962 			return 0;
2963 		}
2964 		ext4_lock_group(sb, i);
2965 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2966 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2967 				 "Checksum for group %u failed (%u!=%u)",
2968 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2969 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2970 			if (!sb_rdonly(sb)) {
2971 				ext4_unlock_group(sb, i);
2972 				return 0;
2973 			}
2974 		}
2975 		ext4_unlock_group(sb, i);
2976 		if (!flexbg_flag)
2977 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2978 	}
2979 	if (NULL != first_not_zeroed)
2980 		*first_not_zeroed = grp;
2981 	return 1;
2982 }
2983 
2984 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2985  * the superblock) which were deleted from all directories, but held open by
2986  * a process at the time of a crash.  We walk the list and try to delete these
2987  * inodes at recovery time (only with a read-write filesystem).
2988  *
2989  * In order to keep the orphan inode chain consistent during traversal (in
2990  * case of crash during recovery), we link each inode into the superblock
2991  * orphan list_head and handle it the same way as an inode deletion during
2992  * normal operation (which journals the operations for us).
2993  *
2994  * We only do an iget() and an iput() on each inode, which is very safe if we
2995  * accidentally point at an in-use or already deleted inode.  The worst that
2996  * can happen in this case is that we get a "bit already cleared" message from
2997  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2998  * e2fsck was run on this filesystem, and it must have already done the orphan
2999  * inode cleanup for us, so we can safely abort without any further action.
3000  */
3001 static void ext4_orphan_cleanup(struct super_block *sb,
3002 				struct ext4_super_block *es)
3003 {
3004 	unsigned int s_flags = sb->s_flags;
3005 	int ret, nr_orphans = 0, nr_truncates = 0;
3006 #ifdef CONFIG_QUOTA
3007 	int quota_update = 0;
3008 	int i;
3009 #endif
3010 	if (!es->s_last_orphan) {
3011 		jbd_debug(4, "no orphan inodes to clean up\n");
3012 		return;
3013 	}
3014 
3015 	if (bdev_read_only(sb->s_bdev)) {
3016 		ext4_msg(sb, KERN_ERR, "write access "
3017 			"unavailable, skipping orphan cleanup");
3018 		return;
3019 	}
3020 
3021 	/* Check if feature set would not allow a r/w mount */
3022 	if (!ext4_feature_set_ok(sb, 0)) {
3023 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
3024 			 "unknown ROCOMPAT features");
3025 		return;
3026 	}
3027 
3028 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3029 		/* don't clear list on RO mount w/ errors */
3030 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
3031 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
3032 				  "clearing orphan list.\n");
3033 			es->s_last_orphan = 0;
3034 		}
3035 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3036 		return;
3037 	}
3038 
3039 	if (s_flags & SB_RDONLY) {
3040 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
3041 		sb->s_flags &= ~SB_RDONLY;
3042 	}
3043 #ifdef CONFIG_QUOTA
3044 	/*
3045 	 * Turn on quotas which were not enabled for read-only mounts if
3046 	 * filesystem has quota feature, so that they are updated correctly.
3047 	 */
3048 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
3049 		int ret = ext4_enable_quotas(sb);
3050 
3051 		if (!ret)
3052 			quota_update = 1;
3053 		else
3054 			ext4_msg(sb, KERN_ERR,
3055 				"Cannot turn on quotas: error %d", ret);
3056 	}
3057 
3058 	/* Turn on journaled quotas used for old sytle */
3059 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3060 		if (EXT4_SB(sb)->s_qf_names[i]) {
3061 			int ret = ext4_quota_on_mount(sb, i);
3062 
3063 			if (!ret)
3064 				quota_update = 1;
3065 			else
3066 				ext4_msg(sb, KERN_ERR,
3067 					"Cannot turn on journaled "
3068 					"quota: type %d: error %d", i, ret);
3069 		}
3070 	}
3071 #endif
3072 
3073 	while (es->s_last_orphan) {
3074 		struct inode *inode;
3075 
3076 		/*
3077 		 * We may have encountered an error during cleanup; if
3078 		 * so, skip the rest.
3079 		 */
3080 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3081 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3082 			es->s_last_orphan = 0;
3083 			break;
3084 		}
3085 
3086 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
3087 		if (IS_ERR(inode)) {
3088 			es->s_last_orphan = 0;
3089 			break;
3090 		}
3091 
3092 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
3093 		dquot_initialize(inode);
3094 		if (inode->i_nlink) {
3095 			if (test_opt(sb, DEBUG))
3096 				ext4_msg(sb, KERN_DEBUG,
3097 					"%s: truncating inode %lu to %lld bytes",
3098 					__func__, inode->i_ino, inode->i_size);
3099 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
3100 				  inode->i_ino, inode->i_size);
3101 			inode_lock(inode);
3102 			truncate_inode_pages(inode->i_mapping, inode->i_size);
3103 			ret = ext4_truncate(inode);
3104 			if (ret)
3105 				ext4_std_error(inode->i_sb, ret);
3106 			inode_unlock(inode);
3107 			nr_truncates++;
3108 		} else {
3109 			if (test_opt(sb, DEBUG))
3110 				ext4_msg(sb, KERN_DEBUG,
3111 					"%s: deleting unreferenced inode %lu",
3112 					__func__, inode->i_ino);
3113 			jbd_debug(2, "deleting unreferenced inode %lu\n",
3114 				  inode->i_ino);
3115 			nr_orphans++;
3116 		}
3117 		iput(inode);  /* The delete magic happens here! */
3118 	}
3119 
3120 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
3121 
3122 	if (nr_orphans)
3123 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
3124 		       PLURAL(nr_orphans));
3125 	if (nr_truncates)
3126 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
3127 		       PLURAL(nr_truncates));
3128 #ifdef CONFIG_QUOTA
3129 	/* Turn off quotas if they were enabled for orphan cleanup */
3130 	if (quota_update) {
3131 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3132 			if (sb_dqopt(sb)->files[i])
3133 				dquot_quota_off(sb, i);
3134 		}
3135 	}
3136 #endif
3137 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
3138 }
3139 
3140 /*
3141  * Maximal extent format file size.
3142  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3143  * extent format containers, within a sector_t, and within i_blocks
3144  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3145  * so that won't be a limiting factor.
3146  *
3147  * However there is other limiting factor. We do store extents in the form
3148  * of starting block and length, hence the resulting length of the extent
3149  * covering maximum file size must fit into on-disk format containers as
3150  * well. Given that length is always by 1 unit bigger than max unit (because
3151  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3152  *
3153  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3154  */
3155 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3156 {
3157 	loff_t res;
3158 	loff_t upper_limit = MAX_LFS_FILESIZE;
3159 
3160 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3161 
3162 	if (!has_huge_files) {
3163 		upper_limit = (1LL << 32) - 1;
3164 
3165 		/* total blocks in file system block size */
3166 		upper_limit >>= (blkbits - 9);
3167 		upper_limit <<= blkbits;
3168 	}
3169 
3170 	/*
3171 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3172 	 * by one fs block, so ee_len can cover the extent of maximum file
3173 	 * size
3174 	 */
3175 	res = (1LL << 32) - 1;
3176 	res <<= blkbits;
3177 
3178 	/* Sanity check against vm- & vfs- imposed limits */
3179 	if (res > upper_limit)
3180 		res = upper_limit;
3181 
3182 	return res;
3183 }
3184 
3185 /*
3186  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3187  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3188  * We need to be 1 filesystem block less than the 2^48 sector limit.
3189  */
3190 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3191 {
3192 	loff_t res = EXT4_NDIR_BLOCKS;
3193 	int meta_blocks;
3194 	loff_t upper_limit;
3195 	/* This is calculated to be the largest file size for a dense, block
3196 	 * mapped file such that the file's total number of 512-byte sectors,
3197 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3198 	 *
3199 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3200 	 * number of 512-byte sectors of the file.
3201 	 */
3202 
3203 	if (!has_huge_files) {
3204 		/*
3205 		 * !has_huge_files or implies that the inode i_block field
3206 		 * represents total file blocks in 2^32 512-byte sectors ==
3207 		 * size of vfs inode i_blocks * 8
3208 		 */
3209 		upper_limit = (1LL << 32) - 1;
3210 
3211 		/* total blocks in file system block size */
3212 		upper_limit >>= (bits - 9);
3213 
3214 	} else {
3215 		/*
3216 		 * We use 48 bit ext4_inode i_blocks
3217 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3218 		 * represent total number of blocks in
3219 		 * file system block size
3220 		 */
3221 		upper_limit = (1LL << 48) - 1;
3222 
3223 	}
3224 
3225 	/* indirect blocks */
3226 	meta_blocks = 1;
3227 	/* double indirect blocks */
3228 	meta_blocks += 1 + (1LL << (bits-2));
3229 	/* tripple indirect blocks */
3230 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3231 
3232 	upper_limit -= meta_blocks;
3233 	upper_limit <<= bits;
3234 
3235 	res += 1LL << (bits-2);
3236 	res += 1LL << (2*(bits-2));
3237 	res += 1LL << (3*(bits-2));
3238 	res <<= bits;
3239 	if (res > upper_limit)
3240 		res = upper_limit;
3241 
3242 	if (res > MAX_LFS_FILESIZE)
3243 		res = MAX_LFS_FILESIZE;
3244 
3245 	return res;
3246 }
3247 
3248 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3249 				   ext4_fsblk_t logical_sb_block, int nr)
3250 {
3251 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3252 	ext4_group_t bg, first_meta_bg;
3253 	int has_super = 0;
3254 
3255 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3256 
3257 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3258 		return logical_sb_block + nr + 1;
3259 	bg = sbi->s_desc_per_block * nr;
3260 	if (ext4_bg_has_super(sb, bg))
3261 		has_super = 1;
3262 
3263 	/*
3264 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3265 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3266 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3267 	 * compensate.
3268 	 */
3269 	if (sb->s_blocksize == 1024 && nr == 0 &&
3270 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3271 		has_super++;
3272 
3273 	return (has_super + ext4_group_first_block_no(sb, bg));
3274 }
3275 
3276 /**
3277  * ext4_get_stripe_size: Get the stripe size.
3278  * @sbi: In memory super block info
3279  *
3280  * If we have specified it via mount option, then
3281  * use the mount option value. If the value specified at mount time is
3282  * greater than the blocks per group use the super block value.
3283  * If the super block value is greater than blocks per group return 0.
3284  * Allocator needs it be less than blocks per group.
3285  *
3286  */
3287 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3288 {
3289 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3290 	unsigned long stripe_width =
3291 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3292 	int ret;
3293 
3294 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3295 		ret = sbi->s_stripe;
3296 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3297 		ret = stripe_width;
3298 	else if (stride && stride <= sbi->s_blocks_per_group)
3299 		ret = stride;
3300 	else
3301 		ret = 0;
3302 
3303 	/*
3304 	 * If the stripe width is 1, this makes no sense and
3305 	 * we set it to 0 to turn off stripe handling code.
3306 	 */
3307 	if (ret <= 1)
3308 		ret = 0;
3309 
3310 	return ret;
3311 }
3312 
3313 /*
3314  * Check whether this filesystem can be mounted based on
3315  * the features present and the RDONLY/RDWR mount requested.
3316  * Returns 1 if this filesystem can be mounted as requested,
3317  * 0 if it cannot be.
3318  */
3319 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3320 {
3321 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3322 		ext4_msg(sb, KERN_ERR,
3323 			"Couldn't mount because of "
3324 			"unsupported optional features (%x)",
3325 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3326 			~EXT4_FEATURE_INCOMPAT_SUPP));
3327 		return 0;
3328 	}
3329 
3330 #ifndef CONFIG_UNICODE
3331 	if (ext4_has_feature_casefold(sb)) {
3332 		ext4_msg(sb, KERN_ERR,
3333 			 "Filesystem with casefold feature cannot be "
3334 			 "mounted without CONFIG_UNICODE");
3335 		return 0;
3336 	}
3337 #endif
3338 
3339 	if (readonly)
3340 		return 1;
3341 
3342 	if (ext4_has_feature_readonly(sb)) {
3343 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3344 		sb->s_flags |= SB_RDONLY;
3345 		return 1;
3346 	}
3347 
3348 	/* Check that feature set is OK for a read-write mount */
3349 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3350 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3351 			 "unsupported optional features (%x)",
3352 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3353 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3354 		return 0;
3355 	}
3356 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3357 		ext4_msg(sb, KERN_ERR,
3358 			 "Can't support bigalloc feature without "
3359 			 "extents feature\n");
3360 		return 0;
3361 	}
3362 
3363 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3364 	if (!readonly && (ext4_has_feature_quota(sb) ||
3365 			  ext4_has_feature_project(sb))) {
3366 		ext4_msg(sb, KERN_ERR,
3367 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3368 		return 0;
3369 	}
3370 #endif  /* CONFIG_QUOTA */
3371 	return 1;
3372 }
3373 
3374 /*
3375  * This function is called once a day if we have errors logged
3376  * on the file system
3377  */
3378 static void print_daily_error_info(struct timer_list *t)
3379 {
3380 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3381 	struct super_block *sb = sbi->s_sb;
3382 	struct ext4_super_block *es = sbi->s_es;
3383 
3384 	if (es->s_error_count)
3385 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3386 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3387 			 le32_to_cpu(es->s_error_count));
3388 	if (es->s_first_error_time) {
3389 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3390 		       sb->s_id,
3391 		       ext4_get_tstamp(es, s_first_error_time),
3392 		       (int) sizeof(es->s_first_error_func),
3393 		       es->s_first_error_func,
3394 		       le32_to_cpu(es->s_first_error_line));
3395 		if (es->s_first_error_ino)
3396 			printk(KERN_CONT ": inode %u",
3397 			       le32_to_cpu(es->s_first_error_ino));
3398 		if (es->s_first_error_block)
3399 			printk(KERN_CONT ": block %llu", (unsigned long long)
3400 			       le64_to_cpu(es->s_first_error_block));
3401 		printk(KERN_CONT "\n");
3402 	}
3403 	if (es->s_last_error_time) {
3404 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3405 		       sb->s_id,
3406 		       ext4_get_tstamp(es, s_last_error_time),
3407 		       (int) sizeof(es->s_last_error_func),
3408 		       es->s_last_error_func,
3409 		       le32_to_cpu(es->s_last_error_line));
3410 		if (es->s_last_error_ino)
3411 			printk(KERN_CONT ": inode %u",
3412 			       le32_to_cpu(es->s_last_error_ino));
3413 		if (es->s_last_error_block)
3414 			printk(KERN_CONT ": block %llu", (unsigned long long)
3415 			       le64_to_cpu(es->s_last_error_block));
3416 		printk(KERN_CONT "\n");
3417 	}
3418 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3419 }
3420 
3421 /* Find next suitable group and run ext4_init_inode_table */
3422 static int ext4_run_li_request(struct ext4_li_request *elr)
3423 {
3424 	struct ext4_group_desc *gdp = NULL;
3425 	struct super_block *sb = elr->lr_super;
3426 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3427 	ext4_group_t group = elr->lr_next_group;
3428 	unsigned long timeout = 0;
3429 	unsigned int prefetch_ios = 0;
3430 	int ret = 0;
3431 
3432 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3433 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3434 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3435 		if (prefetch_ios)
3436 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3437 					      prefetch_ios);
3438 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3439 					    prefetch_ios);
3440 		if (group >= elr->lr_next_group) {
3441 			ret = 1;
3442 			if (elr->lr_first_not_zeroed != ngroups &&
3443 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3444 				elr->lr_next_group = elr->lr_first_not_zeroed;
3445 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3446 				ret = 0;
3447 			}
3448 		}
3449 		return ret;
3450 	}
3451 
3452 	for (; group < ngroups; group++) {
3453 		gdp = ext4_get_group_desc(sb, group, NULL);
3454 		if (!gdp) {
3455 			ret = 1;
3456 			break;
3457 		}
3458 
3459 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3460 			break;
3461 	}
3462 
3463 	if (group >= ngroups)
3464 		ret = 1;
3465 
3466 	if (!ret) {
3467 		timeout = jiffies;
3468 		ret = ext4_init_inode_table(sb, group,
3469 					    elr->lr_timeout ? 0 : 1);
3470 		trace_ext4_lazy_itable_init(sb, group);
3471 		if (elr->lr_timeout == 0) {
3472 			timeout = (jiffies - timeout) *
3473 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3474 			elr->lr_timeout = timeout;
3475 		}
3476 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3477 		elr->lr_next_group = group + 1;
3478 	}
3479 	return ret;
3480 }
3481 
3482 /*
3483  * Remove lr_request from the list_request and free the
3484  * request structure. Should be called with li_list_mtx held
3485  */
3486 static void ext4_remove_li_request(struct ext4_li_request *elr)
3487 {
3488 	if (!elr)
3489 		return;
3490 
3491 	list_del(&elr->lr_request);
3492 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3493 	kfree(elr);
3494 }
3495 
3496 static void ext4_unregister_li_request(struct super_block *sb)
3497 {
3498 	mutex_lock(&ext4_li_mtx);
3499 	if (!ext4_li_info) {
3500 		mutex_unlock(&ext4_li_mtx);
3501 		return;
3502 	}
3503 
3504 	mutex_lock(&ext4_li_info->li_list_mtx);
3505 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3506 	mutex_unlock(&ext4_li_info->li_list_mtx);
3507 	mutex_unlock(&ext4_li_mtx);
3508 }
3509 
3510 static struct task_struct *ext4_lazyinit_task;
3511 
3512 /*
3513  * This is the function where ext4lazyinit thread lives. It walks
3514  * through the request list searching for next scheduled filesystem.
3515  * When such a fs is found, run the lazy initialization request
3516  * (ext4_rn_li_request) and keep track of the time spend in this
3517  * function. Based on that time we compute next schedule time of
3518  * the request. When walking through the list is complete, compute
3519  * next waking time and put itself into sleep.
3520  */
3521 static int ext4_lazyinit_thread(void *arg)
3522 {
3523 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3524 	struct list_head *pos, *n;
3525 	struct ext4_li_request *elr;
3526 	unsigned long next_wakeup, cur;
3527 
3528 	BUG_ON(NULL == eli);
3529 
3530 cont_thread:
3531 	while (true) {
3532 		next_wakeup = MAX_JIFFY_OFFSET;
3533 
3534 		mutex_lock(&eli->li_list_mtx);
3535 		if (list_empty(&eli->li_request_list)) {
3536 			mutex_unlock(&eli->li_list_mtx);
3537 			goto exit_thread;
3538 		}
3539 		list_for_each_safe(pos, n, &eli->li_request_list) {
3540 			int err = 0;
3541 			int progress = 0;
3542 			elr = list_entry(pos, struct ext4_li_request,
3543 					 lr_request);
3544 
3545 			if (time_before(jiffies, elr->lr_next_sched)) {
3546 				if (time_before(elr->lr_next_sched, next_wakeup))
3547 					next_wakeup = elr->lr_next_sched;
3548 				continue;
3549 			}
3550 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3551 				if (sb_start_write_trylock(elr->lr_super)) {
3552 					progress = 1;
3553 					/*
3554 					 * We hold sb->s_umount, sb can not
3555 					 * be removed from the list, it is
3556 					 * now safe to drop li_list_mtx
3557 					 */
3558 					mutex_unlock(&eli->li_list_mtx);
3559 					err = ext4_run_li_request(elr);
3560 					sb_end_write(elr->lr_super);
3561 					mutex_lock(&eli->li_list_mtx);
3562 					n = pos->next;
3563 				}
3564 				up_read((&elr->lr_super->s_umount));
3565 			}
3566 			/* error, remove the lazy_init job */
3567 			if (err) {
3568 				ext4_remove_li_request(elr);
3569 				continue;
3570 			}
3571 			if (!progress) {
3572 				elr->lr_next_sched = jiffies +
3573 					(prandom_u32()
3574 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3575 			}
3576 			if (time_before(elr->lr_next_sched, next_wakeup))
3577 				next_wakeup = elr->lr_next_sched;
3578 		}
3579 		mutex_unlock(&eli->li_list_mtx);
3580 
3581 		try_to_freeze();
3582 
3583 		cur = jiffies;
3584 		if ((time_after_eq(cur, next_wakeup)) ||
3585 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3586 			cond_resched();
3587 			continue;
3588 		}
3589 
3590 		schedule_timeout_interruptible(next_wakeup - cur);
3591 
3592 		if (kthread_should_stop()) {
3593 			ext4_clear_request_list();
3594 			goto exit_thread;
3595 		}
3596 	}
3597 
3598 exit_thread:
3599 	/*
3600 	 * It looks like the request list is empty, but we need
3601 	 * to check it under the li_list_mtx lock, to prevent any
3602 	 * additions into it, and of course we should lock ext4_li_mtx
3603 	 * to atomically free the list and ext4_li_info, because at
3604 	 * this point another ext4 filesystem could be registering
3605 	 * new one.
3606 	 */
3607 	mutex_lock(&ext4_li_mtx);
3608 	mutex_lock(&eli->li_list_mtx);
3609 	if (!list_empty(&eli->li_request_list)) {
3610 		mutex_unlock(&eli->li_list_mtx);
3611 		mutex_unlock(&ext4_li_mtx);
3612 		goto cont_thread;
3613 	}
3614 	mutex_unlock(&eli->li_list_mtx);
3615 	kfree(ext4_li_info);
3616 	ext4_li_info = NULL;
3617 	mutex_unlock(&ext4_li_mtx);
3618 
3619 	return 0;
3620 }
3621 
3622 static void ext4_clear_request_list(void)
3623 {
3624 	struct list_head *pos, *n;
3625 	struct ext4_li_request *elr;
3626 
3627 	mutex_lock(&ext4_li_info->li_list_mtx);
3628 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3629 		elr = list_entry(pos, struct ext4_li_request,
3630 				 lr_request);
3631 		ext4_remove_li_request(elr);
3632 	}
3633 	mutex_unlock(&ext4_li_info->li_list_mtx);
3634 }
3635 
3636 static int ext4_run_lazyinit_thread(void)
3637 {
3638 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3639 					 ext4_li_info, "ext4lazyinit");
3640 	if (IS_ERR(ext4_lazyinit_task)) {
3641 		int err = PTR_ERR(ext4_lazyinit_task);
3642 		ext4_clear_request_list();
3643 		kfree(ext4_li_info);
3644 		ext4_li_info = NULL;
3645 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3646 				 "initialization thread\n",
3647 				 err);
3648 		return err;
3649 	}
3650 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3651 	return 0;
3652 }
3653 
3654 /*
3655  * Check whether it make sense to run itable init. thread or not.
3656  * If there is at least one uninitialized inode table, return
3657  * corresponding group number, else the loop goes through all
3658  * groups and return total number of groups.
3659  */
3660 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3661 {
3662 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3663 	struct ext4_group_desc *gdp = NULL;
3664 
3665 	if (!ext4_has_group_desc_csum(sb))
3666 		return ngroups;
3667 
3668 	for (group = 0; group < ngroups; group++) {
3669 		gdp = ext4_get_group_desc(sb, group, NULL);
3670 		if (!gdp)
3671 			continue;
3672 
3673 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3674 			break;
3675 	}
3676 
3677 	return group;
3678 }
3679 
3680 static int ext4_li_info_new(void)
3681 {
3682 	struct ext4_lazy_init *eli = NULL;
3683 
3684 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3685 	if (!eli)
3686 		return -ENOMEM;
3687 
3688 	INIT_LIST_HEAD(&eli->li_request_list);
3689 	mutex_init(&eli->li_list_mtx);
3690 
3691 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3692 
3693 	ext4_li_info = eli;
3694 
3695 	return 0;
3696 }
3697 
3698 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3699 					    ext4_group_t start)
3700 {
3701 	struct ext4_li_request *elr;
3702 
3703 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3704 	if (!elr)
3705 		return NULL;
3706 
3707 	elr->lr_super = sb;
3708 	elr->lr_first_not_zeroed = start;
3709 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3710 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3711 		elr->lr_next_group = start;
3712 	} else {
3713 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3714 	}
3715 
3716 	/*
3717 	 * Randomize first schedule time of the request to
3718 	 * spread the inode table initialization requests
3719 	 * better.
3720 	 */
3721 	elr->lr_next_sched = jiffies + (prandom_u32() %
3722 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3723 	return elr;
3724 }
3725 
3726 int ext4_register_li_request(struct super_block *sb,
3727 			     ext4_group_t first_not_zeroed)
3728 {
3729 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3730 	struct ext4_li_request *elr = NULL;
3731 	ext4_group_t ngroups = sbi->s_groups_count;
3732 	int ret = 0;
3733 
3734 	mutex_lock(&ext4_li_mtx);
3735 	if (sbi->s_li_request != NULL) {
3736 		/*
3737 		 * Reset timeout so it can be computed again, because
3738 		 * s_li_wait_mult might have changed.
3739 		 */
3740 		sbi->s_li_request->lr_timeout = 0;
3741 		goto out;
3742 	}
3743 
3744 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3745 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3746 	     !test_opt(sb, INIT_INODE_TABLE)))
3747 		goto out;
3748 
3749 	elr = ext4_li_request_new(sb, first_not_zeroed);
3750 	if (!elr) {
3751 		ret = -ENOMEM;
3752 		goto out;
3753 	}
3754 
3755 	if (NULL == ext4_li_info) {
3756 		ret = ext4_li_info_new();
3757 		if (ret)
3758 			goto out;
3759 	}
3760 
3761 	mutex_lock(&ext4_li_info->li_list_mtx);
3762 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3763 	mutex_unlock(&ext4_li_info->li_list_mtx);
3764 
3765 	sbi->s_li_request = elr;
3766 	/*
3767 	 * set elr to NULL here since it has been inserted to
3768 	 * the request_list and the removal and free of it is
3769 	 * handled by ext4_clear_request_list from now on.
3770 	 */
3771 	elr = NULL;
3772 
3773 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3774 		ret = ext4_run_lazyinit_thread();
3775 		if (ret)
3776 			goto out;
3777 	}
3778 out:
3779 	mutex_unlock(&ext4_li_mtx);
3780 	if (ret)
3781 		kfree(elr);
3782 	return ret;
3783 }
3784 
3785 /*
3786  * We do not need to lock anything since this is called on
3787  * module unload.
3788  */
3789 static void ext4_destroy_lazyinit_thread(void)
3790 {
3791 	/*
3792 	 * If thread exited earlier
3793 	 * there's nothing to be done.
3794 	 */
3795 	if (!ext4_li_info || !ext4_lazyinit_task)
3796 		return;
3797 
3798 	kthread_stop(ext4_lazyinit_task);
3799 }
3800 
3801 static int set_journal_csum_feature_set(struct super_block *sb)
3802 {
3803 	int ret = 1;
3804 	int compat, incompat;
3805 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3806 
3807 	if (ext4_has_metadata_csum(sb)) {
3808 		/* journal checksum v3 */
3809 		compat = 0;
3810 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3811 	} else {
3812 		/* journal checksum v1 */
3813 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3814 		incompat = 0;
3815 	}
3816 
3817 	jbd2_journal_clear_features(sbi->s_journal,
3818 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3819 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3820 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3821 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3822 		ret = jbd2_journal_set_features(sbi->s_journal,
3823 				compat, 0,
3824 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3825 				incompat);
3826 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3827 		ret = jbd2_journal_set_features(sbi->s_journal,
3828 				compat, 0,
3829 				incompat);
3830 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3831 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3832 	} else {
3833 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3834 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3835 	}
3836 
3837 	return ret;
3838 }
3839 
3840 /*
3841  * Note: calculating the overhead so we can be compatible with
3842  * historical BSD practice is quite difficult in the face of
3843  * clusters/bigalloc.  This is because multiple metadata blocks from
3844  * different block group can end up in the same allocation cluster.
3845  * Calculating the exact overhead in the face of clustered allocation
3846  * requires either O(all block bitmaps) in memory or O(number of block
3847  * groups**2) in time.  We will still calculate the superblock for
3848  * older file systems --- and if we come across with a bigalloc file
3849  * system with zero in s_overhead_clusters the estimate will be close to
3850  * correct especially for very large cluster sizes --- but for newer
3851  * file systems, it's better to calculate this figure once at mkfs
3852  * time, and store it in the superblock.  If the superblock value is
3853  * present (even for non-bigalloc file systems), we will use it.
3854  */
3855 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3856 			  char *buf)
3857 {
3858 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3859 	struct ext4_group_desc	*gdp;
3860 	ext4_fsblk_t		first_block, last_block, b;
3861 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3862 	int			s, j, count = 0;
3863 
3864 	if (!ext4_has_feature_bigalloc(sb))
3865 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3866 			sbi->s_itb_per_group + 2);
3867 
3868 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3869 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3870 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3871 	for (i = 0; i < ngroups; i++) {
3872 		gdp = ext4_get_group_desc(sb, i, NULL);
3873 		b = ext4_block_bitmap(sb, gdp);
3874 		if (b >= first_block && b <= last_block) {
3875 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3876 			count++;
3877 		}
3878 		b = ext4_inode_bitmap(sb, gdp);
3879 		if (b >= first_block && b <= last_block) {
3880 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3881 			count++;
3882 		}
3883 		b = ext4_inode_table(sb, gdp);
3884 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3885 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3886 				int c = EXT4_B2C(sbi, b - first_block);
3887 				ext4_set_bit(c, buf);
3888 				count++;
3889 			}
3890 		if (i != grp)
3891 			continue;
3892 		s = 0;
3893 		if (ext4_bg_has_super(sb, grp)) {
3894 			ext4_set_bit(s++, buf);
3895 			count++;
3896 		}
3897 		j = ext4_bg_num_gdb(sb, grp);
3898 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3899 			ext4_error(sb, "Invalid number of block group "
3900 				   "descriptor blocks: %d", j);
3901 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3902 		}
3903 		count += j;
3904 		for (; j > 0; j--)
3905 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3906 	}
3907 	if (!count)
3908 		return 0;
3909 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3910 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3911 }
3912 
3913 /*
3914  * Compute the overhead and stash it in sbi->s_overhead
3915  */
3916 int ext4_calculate_overhead(struct super_block *sb)
3917 {
3918 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3919 	struct ext4_super_block *es = sbi->s_es;
3920 	struct inode *j_inode;
3921 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3922 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3923 	ext4_fsblk_t overhead = 0;
3924 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3925 
3926 	if (!buf)
3927 		return -ENOMEM;
3928 
3929 	/*
3930 	 * Compute the overhead (FS structures).  This is constant
3931 	 * for a given filesystem unless the number of block groups
3932 	 * changes so we cache the previous value until it does.
3933 	 */
3934 
3935 	/*
3936 	 * All of the blocks before first_data_block are overhead
3937 	 */
3938 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3939 
3940 	/*
3941 	 * Add the overhead found in each block group
3942 	 */
3943 	for (i = 0; i < ngroups; i++) {
3944 		int blks;
3945 
3946 		blks = count_overhead(sb, i, buf);
3947 		overhead += blks;
3948 		if (blks)
3949 			memset(buf, 0, PAGE_SIZE);
3950 		cond_resched();
3951 	}
3952 
3953 	/*
3954 	 * Add the internal journal blocks whether the journal has been
3955 	 * loaded or not
3956 	 */
3957 	if (sbi->s_journal && !sbi->s_journal_bdev)
3958 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
3959 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3960 		/* j_inum for internal journal is non-zero */
3961 		j_inode = ext4_get_journal_inode(sb, j_inum);
3962 		if (j_inode) {
3963 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3964 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3965 			iput(j_inode);
3966 		} else {
3967 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3968 		}
3969 	}
3970 	sbi->s_overhead = overhead;
3971 	smp_wmb();
3972 	free_page((unsigned long) buf);
3973 	return 0;
3974 }
3975 
3976 static void ext4_set_resv_clusters(struct super_block *sb)
3977 {
3978 	ext4_fsblk_t resv_clusters;
3979 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3980 
3981 	/*
3982 	 * There's no need to reserve anything when we aren't using extents.
3983 	 * The space estimates are exact, there are no unwritten extents,
3984 	 * hole punching doesn't need new metadata... This is needed especially
3985 	 * to keep ext2/3 backward compatibility.
3986 	 */
3987 	if (!ext4_has_feature_extents(sb))
3988 		return;
3989 	/*
3990 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3991 	 * This should cover the situations where we can not afford to run
3992 	 * out of space like for example punch hole, or converting
3993 	 * unwritten extents in delalloc path. In most cases such
3994 	 * allocation would require 1, or 2 blocks, higher numbers are
3995 	 * very rare.
3996 	 */
3997 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3998 			 sbi->s_cluster_bits);
3999 
4000 	do_div(resv_clusters, 50);
4001 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4002 
4003 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4004 }
4005 
4006 static const char *ext4_quota_mode(struct super_block *sb)
4007 {
4008 #ifdef CONFIG_QUOTA
4009 	if (!ext4_quota_capable(sb))
4010 		return "none";
4011 
4012 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4013 		return "journalled";
4014 	else
4015 		return "writeback";
4016 #else
4017 	return "disabled";
4018 #endif
4019 }
4020 
4021 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
4022 {
4023 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
4024 	char *orig_data = kstrdup(data, GFP_KERNEL);
4025 	struct buffer_head *bh, **group_desc;
4026 	struct ext4_super_block *es = NULL;
4027 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4028 	struct flex_groups **flex_groups;
4029 	ext4_fsblk_t block;
4030 	ext4_fsblk_t sb_block = get_sb_block(&data);
4031 	ext4_fsblk_t logical_sb_block;
4032 	unsigned long offset = 0;
4033 	unsigned long def_mount_opts;
4034 	struct inode *root;
4035 	const char *descr;
4036 	int ret = -ENOMEM;
4037 	int blocksize, clustersize;
4038 	unsigned int db_count;
4039 	unsigned int i;
4040 	int needs_recovery, has_huge_files;
4041 	__u64 blocks_count;
4042 	int err = 0;
4043 	ext4_group_t first_not_zeroed;
4044 	struct ext4_parsed_options parsed_opts;
4045 
4046 	/* Set defaults for the variables that will be set during parsing */
4047 	parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4048 	parsed_opts.journal_devnum = 0;
4049 	parsed_opts.mb_optimize_scan = DEFAULT_MB_OPTIMIZE_SCAN;
4050 
4051 	if ((data && !orig_data) || !sbi)
4052 		goto out_free_base;
4053 
4054 	sbi->s_daxdev = dax_dev;
4055 	sbi->s_blockgroup_lock =
4056 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4057 	if (!sbi->s_blockgroup_lock)
4058 		goto out_free_base;
4059 
4060 	sb->s_fs_info = sbi;
4061 	sbi->s_sb = sb;
4062 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4063 	sbi->s_sb_block = sb_block;
4064 	sbi->s_sectors_written_start =
4065 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4066 
4067 	/* Cleanup superblock name */
4068 	strreplace(sb->s_id, '/', '!');
4069 
4070 	/* -EINVAL is default */
4071 	ret = -EINVAL;
4072 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4073 	if (!blocksize) {
4074 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4075 		goto out_fail;
4076 	}
4077 
4078 	/*
4079 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4080 	 * block sizes.  We need to calculate the offset from buffer start.
4081 	 */
4082 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4083 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4084 		offset = do_div(logical_sb_block, blocksize);
4085 	} else {
4086 		logical_sb_block = sb_block;
4087 	}
4088 
4089 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4090 	if (IS_ERR(bh)) {
4091 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4092 		ret = PTR_ERR(bh);
4093 		goto out_fail;
4094 	}
4095 	/*
4096 	 * Note: s_es must be initialized as soon as possible because
4097 	 *       some ext4 macro-instructions depend on its value
4098 	 */
4099 	es = (struct ext4_super_block *) (bh->b_data + offset);
4100 	sbi->s_es = es;
4101 	sb->s_magic = le16_to_cpu(es->s_magic);
4102 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4103 		goto cantfind_ext4;
4104 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4105 
4106 	/* Warn if metadata_csum and gdt_csum are both set. */
4107 	if (ext4_has_feature_metadata_csum(sb) &&
4108 	    ext4_has_feature_gdt_csum(sb))
4109 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4110 			     "redundant flags; please run fsck.");
4111 
4112 	/* Check for a known checksum algorithm */
4113 	if (!ext4_verify_csum_type(sb, es)) {
4114 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4115 			 "unknown checksum algorithm.");
4116 		silent = 1;
4117 		goto cantfind_ext4;
4118 	}
4119 
4120 	/* Load the checksum driver */
4121 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4122 	if (IS_ERR(sbi->s_chksum_driver)) {
4123 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4124 		ret = PTR_ERR(sbi->s_chksum_driver);
4125 		sbi->s_chksum_driver = NULL;
4126 		goto failed_mount;
4127 	}
4128 
4129 	/* Check superblock checksum */
4130 	if (!ext4_superblock_csum_verify(sb, es)) {
4131 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4132 			 "invalid superblock checksum.  Run e2fsck?");
4133 		silent = 1;
4134 		ret = -EFSBADCRC;
4135 		goto cantfind_ext4;
4136 	}
4137 
4138 	/* Precompute checksum seed for all metadata */
4139 	if (ext4_has_feature_csum_seed(sb))
4140 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4141 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4142 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4143 					       sizeof(es->s_uuid));
4144 
4145 	/* Set defaults before we parse the mount options */
4146 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4147 	set_opt(sb, INIT_INODE_TABLE);
4148 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4149 		set_opt(sb, DEBUG);
4150 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4151 		set_opt(sb, GRPID);
4152 	if (def_mount_opts & EXT4_DEFM_UID16)
4153 		set_opt(sb, NO_UID32);
4154 	/* xattr user namespace & acls are now defaulted on */
4155 	set_opt(sb, XATTR_USER);
4156 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4157 	set_opt(sb, POSIX_ACL);
4158 #endif
4159 	if (ext4_has_feature_fast_commit(sb))
4160 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4161 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4162 	if (ext4_has_metadata_csum(sb))
4163 		set_opt(sb, JOURNAL_CHECKSUM);
4164 
4165 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4166 		set_opt(sb, JOURNAL_DATA);
4167 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4168 		set_opt(sb, ORDERED_DATA);
4169 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4170 		set_opt(sb, WRITEBACK_DATA);
4171 
4172 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4173 		set_opt(sb, ERRORS_PANIC);
4174 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4175 		set_opt(sb, ERRORS_CONT);
4176 	else
4177 		set_opt(sb, ERRORS_RO);
4178 	/* block_validity enabled by default; disable with noblock_validity */
4179 	set_opt(sb, BLOCK_VALIDITY);
4180 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4181 		set_opt(sb, DISCARD);
4182 
4183 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4184 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4185 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4186 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4187 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4188 
4189 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4190 		set_opt(sb, BARRIER);
4191 
4192 	/*
4193 	 * enable delayed allocation by default
4194 	 * Use -o nodelalloc to turn it off
4195 	 */
4196 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4197 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4198 		set_opt(sb, DELALLOC);
4199 
4200 	/*
4201 	 * set default s_li_wait_mult for lazyinit, for the case there is
4202 	 * no mount option specified.
4203 	 */
4204 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4205 
4206 	if (le32_to_cpu(es->s_log_block_size) >
4207 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4208 		ext4_msg(sb, KERN_ERR,
4209 			 "Invalid log block size: %u",
4210 			 le32_to_cpu(es->s_log_block_size));
4211 		goto failed_mount;
4212 	}
4213 	if (le32_to_cpu(es->s_log_cluster_size) >
4214 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4215 		ext4_msg(sb, KERN_ERR,
4216 			 "Invalid log cluster size: %u",
4217 			 le32_to_cpu(es->s_log_cluster_size));
4218 		goto failed_mount;
4219 	}
4220 
4221 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4222 
4223 	if (blocksize == PAGE_SIZE)
4224 		set_opt(sb, DIOREAD_NOLOCK);
4225 
4226 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4227 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4228 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4229 	} else {
4230 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4231 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4232 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4233 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4234 				 sbi->s_first_ino);
4235 			goto failed_mount;
4236 		}
4237 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4238 		    (!is_power_of_2(sbi->s_inode_size)) ||
4239 		    (sbi->s_inode_size > blocksize)) {
4240 			ext4_msg(sb, KERN_ERR,
4241 			       "unsupported inode size: %d",
4242 			       sbi->s_inode_size);
4243 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4244 			goto failed_mount;
4245 		}
4246 		/*
4247 		 * i_atime_extra is the last extra field available for
4248 		 * [acm]times in struct ext4_inode. Checking for that
4249 		 * field should suffice to ensure we have extra space
4250 		 * for all three.
4251 		 */
4252 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4253 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4254 			sb->s_time_gran = 1;
4255 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4256 		} else {
4257 			sb->s_time_gran = NSEC_PER_SEC;
4258 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4259 		}
4260 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4261 	}
4262 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4263 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4264 			EXT4_GOOD_OLD_INODE_SIZE;
4265 		if (ext4_has_feature_extra_isize(sb)) {
4266 			unsigned v, max = (sbi->s_inode_size -
4267 					   EXT4_GOOD_OLD_INODE_SIZE);
4268 
4269 			v = le16_to_cpu(es->s_want_extra_isize);
4270 			if (v > max) {
4271 				ext4_msg(sb, KERN_ERR,
4272 					 "bad s_want_extra_isize: %d", v);
4273 				goto failed_mount;
4274 			}
4275 			if (sbi->s_want_extra_isize < v)
4276 				sbi->s_want_extra_isize = v;
4277 
4278 			v = le16_to_cpu(es->s_min_extra_isize);
4279 			if (v > max) {
4280 				ext4_msg(sb, KERN_ERR,
4281 					 "bad s_min_extra_isize: %d", v);
4282 				goto failed_mount;
4283 			}
4284 			if (sbi->s_want_extra_isize < v)
4285 				sbi->s_want_extra_isize = v;
4286 		}
4287 	}
4288 
4289 	if (sbi->s_es->s_mount_opts[0]) {
4290 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4291 					      sizeof(sbi->s_es->s_mount_opts),
4292 					      GFP_KERNEL);
4293 		if (!s_mount_opts)
4294 			goto failed_mount;
4295 		if (!parse_options(s_mount_opts, sb, &parsed_opts, 0)) {
4296 			ext4_msg(sb, KERN_WARNING,
4297 				 "failed to parse options in superblock: %s",
4298 				 s_mount_opts);
4299 		}
4300 		kfree(s_mount_opts);
4301 	}
4302 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4303 	if (!parse_options((char *) data, sb, &parsed_opts, 0))
4304 		goto failed_mount;
4305 
4306 #ifdef CONFIG_UNICODE
4307 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4308 		const struct ext4_sb_encodings *encoding_info;
4309 		struct unicode_map *encoding;
4310 		__u16 encoding_flags;
4311 
4312 		if (ext4_sb_read_encoding(es, &encoding_info,
4313 					  &encoding_flags)) {
4314 			ext4_msg(sb, KERN_ERR,
4315 				 "Encoding requested by superblock is unknown");
4316 			goto failed_mount;
4317 		}
4318 
4319 		encoding = utf8_load(encoding_info->version);
4320 		if (IS_ERR(encoding)) {
4321 			ext4_msg(sb, KERN_ERR,
4322 				 "can't mount with superblock charset: %s-%s "
4323 				 "not supported by the kernel. flags: 0x%x.",
4324 				 encoding_info->name, encoding_info->version,
4325 				 encoding_flags);
4326 			goto failed_mount;
4327 		}
4328 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4329 			 "%s-%s with flags 0x%hx", encoding_info->name,
4330 			 encoding_info->version?:"\b", encoding_flags);
4331 
4332 		sb->s_encoding = encoding;
4333 		sb->s_encoding_flags = encoding_flags;
4334 	}
4335 #endif
4336 
4337 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4338 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4339 		/* can't mount with both data=journal and dioread_nolock. */
4340 		clear_opt(sb, DIOREAD_NOLOCK);
4341 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4342 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4343 			ext4_msg(sb, KERN_ERR, "can't mount with "
4344 				 "both data=journal and delalloc");
4345 			goto failed_mount;
4346 		}
4347 		if (test_opt(sb, DAX_ALWAYS)) {
4348 			ext4_msg(sb, KERN_ERR, "can't mount with "
4349 				 "both data=journal and dax");
4350 			goto failed_mount;
4351 		}
4352 		if (ext4_has_feature_encrypt(sb)) {
4353 			ext4_msg(sb, KERN_WARNING,
4354 				 "encrypted files will use data=ordered "
4355 				 "instead of data journaling mode");
4356 		}
4357 		if (test_opt(sb, DELALLOC))
4358 			clear_opt(sb, DELALLOC);
4359 	} else {
4360 		sb->s_iflags |= SB_I_CGROUPWB;
4361 	}
4362 
4363 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4364 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4365 
4366 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4367 	    (ext4_has_compat_features(sb) ||
4368 	     ext4_has_ro_compat_features(sb) ||
4369 	     ext4_has_incompat_features(sb)))
4370 		ext4_msg(sb, KERN_WARNING,
4371 		       "feature flags set on rev 0 fs, "
4372 		       "running e2fsck is recommended");
4373 
4374 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4375 		set_opt2(sb, HURD_COMPAT);
4376 		if (ext4_has_feature_64bit(sb)) {
4377 			ext4_msg(sb, KERN_ERR,
4378 				 "The Hurd can't support 64-bit file systems");
4379 			goto failed_mount;
4380 		}
4381 
4382 		/*
4383 		 * ea_inode feature uses l_i_version field which is not
4384 		 * available in HURD_COMPAT mode.
4385 		 */
4386 		if (ext4_has_feature_ea_inode(sb)) {
4387 			ext4_msg(sb, KERN_ERR,
4388 				 "ea_inode feature is not supported for Hurd");
4389 			goto failed_mount;
4390 		}
4391 	}
4392 
4393 	if (IS_EXT2_SB(sb)) {
4394 		if (ext2_feature_set_ok(sb))
4395 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4396 				 "using the ext4 subsystem");
4397 		else {
4398 			/*
4399 			 * If we're probing be silent, if this looks like
4400 			 * it's actually an ext[34] filesystem.
4401 			 */
4402 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4403 				goto failed_mount;
4404 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4405 				 "to feature incompatibilities");
4406 			goto failed_mount;
4407 		}
4408 	}
4409 
4410 	if (IS_EXT3_SB(sb)) {
4411 		if (ext3_feature_set_ok(sb))
4412 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4413 				 "using the ext4 subsystem");
4414 		else {
4415 			/*
4416 			 * If we're probing be silent, if this looks like
4417 			 * it's actually an ext4 filesystem.
4418 			 */
4419 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4420 				goto failed_mount;
4421 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4422 				 "to feature incompatibilities");
4423 			goto failed_mount;
4424 		}
4425 	}
4426 
4427 	/*
4428 	 * Check feature flags regardless of the revision level, since we
4429 	 * previously didn't change the revision level when setting the flags,
4430 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4431 	 */
4432 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4433 		goto failed_mount;
4434 
4435 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4436 		ext4_msg(sb, KERN_ERR,
4437 			 "Number of reserved GDT blocks insanely large: %d",
4438 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4439 		goto failed_mount;
4440 	}
4441 
4442 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4443 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4444 
4445 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4446 		if (ext4_has_feature_inline_data(sb)) {
4447 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4448 					" that may contain inline data");
4449 			goto failed_mount;
4450 		}
4451 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4452 			ext4_msg(sb, KERN_ERR,
4453 				"DAX unsupported by block device.");
4454 			goto failed_mount;
4455 		}
4456 	}
4457 
4458 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4459 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4460 			 es->s_encryption_level);
4461 		goto failed_mount;
4462 	}
4463 
4464 	if (sb->s_blocksize != blocksize) {
4465 		/* Validate the filesystem blocksize */
4466 		if (!sb_set_blocksize(sb, blocksize)) {
4467 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4468 					blocksize);
4469 			goto failed_mount;
4470 		}
4471 
4472 		brelse(bh);
4473 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4474 		offset = do_div(logical_sb_block, blocksize);
4475 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4476 		if (IS_ERR(bh)) {
4477 			ext4_msg(sb, KERN_ERR,
4478 			       "Can't read superblock on 2nd try");
4479 			ret = PTR_ERR(bh);
4480 			bh = NULL;
4481 			goto failed_mount;
4482 		}
4483 		es = (struct ext4_super_block *)(bh->b_data + offset);
4484 		sbi->s_es = es;
4485 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4486 			ext4_msg(sb, KERN_ERR,
4487 			       "Magic mismatch, very weird!");
4488 			goto failed_mount;
4489 		}
4490 	}
4491 
4492 	has_huge_files = ext4_has_feature_huge_file(sb);
4493 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4494 						      has_huge_files);
4495 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4496 
4497 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4498 	if (ext4_has_feature_64bit(sb)) {
4499 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4500 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4501 		    !is_power_of_2(sbi->s_desc_size)) {
4502 			ext4_msg(sb, KERN_ERR,
4503 			       "unsupported descriptor size %lu",
4504 			       sbi->s_desc_size);
4505 			goto failed_mount;
4506 		}
4507 	} else
4508 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4509 
4510 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4511 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4512 
4513 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4514 	if (sbi->s_inodes_per_block == 0)
4515 		goto cantfind_ext4;
4516 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4517 	    sbi->s_inodes_per_group > blocksize * 8) {
4518 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4519 			 sbi->s_inodes_per_group);
4520 		goto failed_mount;
4521 	}
4522 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4523 					sbi->s_inodes_per_block;
4524 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4525 	sbi->s_sbh = bh;
4526 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4527 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4528 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4529 
4530 	for (i = 0; i < 4; i++)
4531 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4532 	sbi->s_def_hash_version = es->s_def_hash_version;
4533 	if (ext4_has_feature_dir_index(sb)) {
4534 		i = le32_to_cpu(es->s_flags);
4535 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4536 			sbi->s_hash_unsigned = 3;
4537 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4538 #ifdef __CHAR_UNSIGNED__
4539 			if (!sb_rdonly(sb))
4540 				es->s_flags |=
4541 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4542 			sbi->s_hash_unsigned = 3;
4543 #else
4544 			if (!sb_rdonly(sb))
4545 				es->s_flags |=
4546 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4547 #endif
4548 		}
4549 	}
4550 
4551 	/* Handle clustersize */
4552 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4553 	if (ext4_has_feature_bigalloc(sb)) {
4554 		if (clustersize < blocksize) {
4555 			ext4_msg(sb, KERN_ERR,
4556 				 "cluster size (%d) smaller than "
4557 				 "block size (%d)", clustersize, blocksize);
4558 			goto failed_mount;
4559 		}
4560 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4561 			le32_to_cpu(es->s_log_block_size);
4562 		sbi->s_clusters_per_group =
4563 			le32_to_cpu(es->s_clusters_per_group);
4564 		if (sbi->s_clusters_per_group > blocksize * 8) {
4565 			ext4_msg(sb, KERN_ERR,
4566 				 "#clusters per group too big: %lu",
4567 				 sbi->s_clusters_per_group);
4568 			goto failed_mount;
4569 		}
4570 		if (sbi->s_blocks_per_group !=
4571 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4572 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4573 				 "clusters per group (%lu) inconsistent",
4574 				 sbi->s_blocks_per_group,
4575 				 sbi->s_clusters_per_group);
4576 			goto failed_mount;
4577 		}
4578 	} else {
4579 		if (clustersize != blocksize) {
4580 			ext4_msg(sb, KERN_ERR,
4581 				 "fragment/cluster size (%d) != "
4582 				 "block size (%d)", clustersize, blocksize);
4583 			goto failed_mount;
4584 		}
4585 		if (sbi->s_blocks_per_group > blocksize * 8) {
4586 			ext4_msg(sb, KERN_ERR,
4587 				 "#blocks per group too big: %lu",
4588 				 sbi->s_blocks_per_group);
4589 			goto failed_mount;
4590 		}
4591 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4592 		sbi->s_cluster_bits = 0;
4593 	}
4594 	sbi->s_cluster_ratio = clustersize / blocksize;
4595 
4596 	/* Do we have standard group size of clustersize * 8 blocks ? */
4597 	if (sbi->s_blocks_per_group == clustersize << 3)
4598 		set_opt2(sb, STD_GROUP_SIZE);
4599 
4600 	/*
4601 	 * Test whether we have more sectors than will fit in sector_t,
4602 	 * and whether the max offset is addressable by the page cache.
4603 	 */
4604 	err = generic_check_addressable(sb->s_blocksize_bits,
4605 					ext4_blocks_count(es));
4606 	if (err) {
4607 		ext4_msg(sb, KERN_ERR, "filesystem"
4608 			 " too large to mount safely on this system");
4609 		goto failed_mount;
4610 	}
4611 
4612 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4613 		goto cantfind_ext4;
4614 
4615 	/* check blocks count against device size */
4616 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4617 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4618 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4619 		       "exceeds size of device (%llu blocks)",
4620 		       ext4_blocks_count(es), blocks_count);
4621 		goto failed_mount;
4622 	}
4623 
4624 	/*
4625 	 * It makes no sense for the first data block to be beyond the end
4626 	 * of the filesystem.
4627 	 */
4628 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4629 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4630 			 "block %u is beyond end of filesystem (%llu)",
4631 			 le32_to_cpu(es->s_first_data_block),
4632 			 ext4_blocks_count(es));
4633 		goto failed_mount;
4634 	}
4635 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4636 	    (sbi->s_cluster_ratio == 1)) {
4637 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4638 			 "block is 0 with a 1k block and cluster size");
4639 		goto failed_mount;
4640 	}
4641 
4642 	blocks_count = (ext4_blocks_count(es) -
4643 			le32_to_cpu(es->s_first_data_block) +
4644 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4645 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4646 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4647 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4648 		       "(block count %llu, first data block %u, "
4649 		       "blocks per group %lu)", blocks_count,
4650 		       ext4_blocks_count(es),
4651 		       le32_to_cpu(es->s_first_data_block),
4652 		       EXT4_BLOCKS_PER_GROUP(sb));
4653 		goto failed_mount;
4654 	}
4655 	sbi->s_groups_count = blocks_count;
4656 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4657 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4658 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4659 	    le32_to_cpu(es->s_inodes_count)) {
4660 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4661 			 le32_to_cpu(es->s_inodes_count),
4662 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4663 		ret = -EINVAL;
4664 		goto failed_mount;
4665 	}
4666 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4667 		   EXT4_DESC_PER_BLOCK(sb);
4668 	if (ext4_has_feature_meta_bg(sb)) {
4669 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4670 			ext4_msg(sb, KERN_WARNING,
4671 				 "first meta block group too large: %u "
4672 				 "(group descriptor block count %u)",
4673 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4674 			goto failed_mount;
4675 		}
4676 	}
4677 	rcu_assign_pointer(sbi->s_group_desc,
4678 			   kvmalloc_array(db_count,
4679 					  sizeof(struct buffer_head *),
4680 					  GFP_KERNEL));
4681 	if (sbi->s_group_desc == NULL) {
4682 		ext4_msg(sb, KERN_ERR, "not enough memory");
4683 		ret = -ENOMEM;
4684 		goto failed_mount;
4685 	}
4686 
4687 	bgl_lock_init(sbi->s_blockgroup_lock);
4688 
4689 	/* Pre-read the descriptors into the buffer cache */
4690 	for (i = 0; i < db_count; i++) {
4691 		block = descriptor_loc(sb, logical_sb_block, i);
4692 		ext4_sb_breadahead_unmovable(sb, block);
4693 	}
4694 
4695 	for (i = 0; i < db_count; i++) {
4696 		struct buffer_head *bh;
4697 
4698 		block = descriptor_loc(sb, logical_sb_block, i);
4699 		bh = ext4_sb_bread_unmovable(sb, block);
4700 		if (IS_ERR(bh)) {
4701 			ext4_msg(sb, KERN_ERR,
4702 			       "can't read group descriptor %d", i);
4703 			db_count = i;
4704 			ret = PTR_ERR(bh);
4705 			goto failed_mount2;
4706 		}
4707 		rcu_read_lock();
4708 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4709 		rcu_read_unlock();
4710 	}
4711 	sbi->s_gdb_count = db_count;
4712 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4713 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4714 		ret = -EFSCORRUPTED;
4715 		goto failed_mount2;
4716 	}
4717 
4718 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4719 	spin_lock_init(&sbi->s_error_lock);
4720 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
4721 
4722 	/* Register extent status tree shrinker */
4723 	if (ext4_es_register_shrinker(sbi))
4724 		goto failed_mount3;
4725 
4726 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4727 	sbi->s_extent_max_zeroout_kb = 32;
4728 
4729 	/*
4730 	 * set up enough so that it can read an inode
4731 	 */
4732 	sb->s_op = &ext4_sops;
4733 	sb->s_export_op = &ext4_export_ops;
4734 	sb->s_xattr = ext4_xattr_handlers;
4735 #ifdef CONFIG_FS_ENCRYPTION
4736 	sb->s_cop = &ext4_cryptops;
4737 #endif
4738 #ifdef CONFIG_FS_VERITY
4739 	sb->s_vop = &ext4_verityops;
4740 #endif
4741 #ifdef CONFIG_QUOTA
4742 	sb->dq_op = &ext4_quota_operations;
4743 	if (ext4_has_feature_quota(sb))
4744 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4745 	else
4746 		sb->s_qcop = &ext4_qctl_operations;
4747 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4748 #endif
4749 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4750 
4751 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4752 	mutex_init(&sbi->s_orphan_lock);
4753 
4754 	/* Initialize fast commit stuff */
4755 	atomic_set(&sbi->s_fc_subtid, 0);
4756 	atomic_set(&sbi->s_fc_ineligible_updates, 0);
4757 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4758 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4759 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4760 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4761 	sbi->s_fc_bytes = 0;
4762 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4763 	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
4764 	spin_lock_init(&sbi->s_fc_lock);
4765 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4766 	sbi->s_fc_replay_state.fc_regions = NULL;
4767 	sbi->s_fc_replay_state.fc_regions_size = 0;
4768 	sbi->s_fc_replay_state.fc_regions_used = 0;
4769 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4770 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4771 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4772 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4773 
4774 	sb->s_root = NULL;
4775 
4776 	needs_recovery = (es->s_last_orphan != 0 ||
4777 			  ext4_has_feature_journal_needs_recovery(sb));
4778 
4779 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4780 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4781 			goto failed_mount3a;
4782 
4783 	/*
4784 	 * The first inode we look at is the journal inode.  Don't try
4785 	 * root first: it may be modified in the journal!
4786 	 */
4787 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4788 		err = ext4_load_journal(sb, es, parsed_opts.journal_devnum);
4789 		if (err)
4790 			goto failed_mount3a;
4791 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4792 		   ext4_has_feature_journal_needs_recovery(sb)) {
4793 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4794 		       "suppressed and not mounted read-only");
4795 		goto failed_mount_wq;
4796 	} else {
4797 		/* Nojournal mode, all journal mount options are illegal */
4798 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4799 			ext4_msg(sb, KERN_ERR, "can't mount with "
4800 				 "journal_checksum, fs mounted w/o journal");
4801 			goto failed_mount_wq;
4802 		}
4803 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4804 			ext4_msg(sb, KERN_ERR, "can't mount with "
4805 				 "journal_async_commit, fs mounted w/o journal");
4806 			goto failed_mount_wq;
4807 		}
4808 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4809 			ext4_msg(sb, KERN_ERR, "can't mount with "
4810 				 "commit=%lu, fs mounted w/o journal",
4811 				 sbi->s_commit_interval / HZ);
4812 			goto failed_mount_wq;
4813 		}
4814 		if (EXT4_MOUNT_DATA_FLAGS &
4815 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4816 			ext4_msg(sb, KERN_ERR, "can't mount with "
4817 				 "data=, fs mounted w/o journal");
4818 			goto failed_mount_wq;
4819 		}
4820 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4821 		clear_opt(sb, JOURNAL_CHECKSUM);
4822 		clear_opt(sb, DATA_FLAGS);
4823 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4824 		sbi->s_journal = NULL;
4825 		needs_recovery = 0;
4826 		goto no_journal;
4827 	}
4828 
4829 	if (ext4_has_feature_64bit(sb) &&
4830 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4831 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4832 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4833 		goto failed_mount_wq;
4834 	}
4835 
4836 	if (!set_journal_csum_feature_set(sb)) {
4837 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4838 			 "feature set");
4839 		goto failed_mount_wq;
4840 	}
4841 
4842 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4843 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4844 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4845 		ext4_msg(sb, KERN_ERR,
4846 			"Failed to set fast commit journal feature");
4847 		goto failed_mount_wq;
4848 	}
4849 
4850 	/* We have now updated the journal if required, so we can
4851 	 * validate the data journaling mode. */
4852 	switch (test_opt(sb, DATA_FLAGS)) {
4853 	case 0:
4854 		/* No mode set, assume a default based on the journal
4855 		 * capabilities: ORDERED_DATA if the journal can
4856 		 * cope, else JOURNAL_DATA
4857 		 */
4858 		if (jbd2_journal_check_available_features
4859 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4860 			set_opt(sb, ORDERED_DATA);
4861 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4862 		} else {
4863 			set_opt(sb, JOURNAL_DATA);
4864 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4865 		}
4866 		break;
4867 
4868 	case EXT4_MOUNT_ORDERED_DATA:
4869 	case EXT4_MOUNT_WRITEBACK_DATA:
4870 		if (!jbd2_journal_check_available_features
4871 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4872 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4873 			       "requested data journaling mode");
4874 			goto failed_mount_wq;
4875 		}
4876 		break;
4877 	default:
4878 		break;
4879 	}
4880 
4881 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4882 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4883 		ext4_msg(sb, KERN_ERR, "can't mount with "
4884 			"journal_async_commit in data=ordered mode");
4885 		goto failed_mount_wq;
4886 	}
4887 
4888 	set_task_ioprio(sbi->s_journal->j_task, parsed_opts.journal_ioprio);
4889 
4890 	sbi->s_journal->j_submit_inode_data_buffers =
4891 		ext4_journal_submit_inode_data_buffers;
4892 	sbi->s_journal->j_finish_inode_data_buffers =
4893 		ext4_journal_finish_inode_data_buffers;
4894 
4895 no_journal:
4896 	if (!test_opt(sb, NO_MBCACHE)) {
4897 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4898 		if (!sbi->s_ea_block_cache) {
4899 			ext4_msg(sb, KERN_ERR,
4900 				 "Failed to create ea_block_cache");
4901 			goto failed_mount_wq;
4902 		}
4903 
4904 		if (ext4_has_feature_ea_inode(sb)) {
4905 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4906 			if (!sbi->s_ea_inode_cache) {
4907 				ext4_msg(sb, KERN_ERR,
4908 					 "Failed to create ea_inode_cache");
4909 				goto failed_mount_wq;
4910 			}
4911 		}
4912 	}
4913 
4914 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4915 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4916 		goto failed_mount_wq;
4917 	}
4918 
4919 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4920 	    !ext4_has_feature_encrypt(sb)) {
4921 		ext4_set_feature_encrypt(sb);
4922 		ext4_commit_super(sb);
4923 	}
4924 
4925 	/*
4926 	 * Get the # of file system overhead blocks from the
4927 	 * superblock if present.
4928 	 */
4929 	if (es->s_overhead_clusters)
4930 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4931 	else {
4932 		err = ext4_calculate_overhead(sb);
4933 		if (err)
4934 			goto failed_mount_wq;
4935 	}
4936 
4937 	/*
4938 	 * The maximum number of concurrent works can be high and
4939 	 * concurrency isn't really necessary.  Limit it to 1.
4940 	 */
4941 	EXT4_SB(sb)->rsv_conversion_wq =
4942 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4943 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4944 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4945 		ret = -ENOMEM;
4946 		goto failed_mount4;
4947 	}
4948 
4949 	/*
4950 	 * The jbd2_journal_load will have done any necessary log recovery,
4951 	 * so we can safely mount the rest of the filesystem now.
4952 	 */
4953 
4954 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4955 	if (IS_ERR(root)) {
4956 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4957 		ret = PTR_ERR(root);
4958 		root = NULL;
4959 		goto failed_mount4;
4960 	}
4961 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4962 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4963 		iput(root);
4964 		goto failed_mount4;
4965 	}
4966 
4967 	sb->s_root = d_make_root(root);
4968 	if (!sb->s_root) {
4969 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4970 		ret = -ENOMEM;
4971 		goto failed_mount4;
4972 	}
4973 
4974 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4975 	if (ret == -EROFS) {
4976 		sb->s_flags |= SB_RDONLY;
4977 		ret = 0;
4978 	} else if (ret)
4979 		goto failed_mount4a;
4980 
4981 	ext4_set_resv_clusters(sb);
4982 
4983 	if (test_opt(sb, BLOCK_VALIDITY)) {
4984 		err = ext4_setup_system_zone(sb);
4985 		if (err) {
4986 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
4987 				 "zone (%d)", err);
4988 			goto failed_mount4a;
4989 		}
4990 	}
4991 	ext4_fc_replay_cleanup(sb);
4992 
4993 	ext4_ext_init(sb);
4994 
4995 	/*
4996 	 * Enable optimize_scan if number of groups is > threshold. This can be
4997 	 * turned off by passing "mb_optimize_scan=0". This can also be
4998 	 * turned on forcefully by passing "mb_optimize_scan=1".
4999 	 */
5000 	if (parsed_opts.mb_optimize_scan == 1)
5001 		set_opt2(sb, MB_OPTIMIZE_SCAN);
5002 	else if (parsed_opts.mb_optimize_scan == 0)
5003 		clear_opt2(sb, MB_OPTIMIZE_SCAN);
5004 	else if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5005 		set_opt2(sb, MB_OPTIMIZE_SCAN);
5006 
5007 	err = ext4_mb_init(sb);
5008 	if (err) {
5009 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5010 			 err);
5011 		goto failed_mount5;
5012 	}
5013 
5014 	/*
5015 	 * We can only set up the journal commit callback once
5016 	 * mballoc is initialized
5017 	 */
5018 	if (sbi->s_journal)
5019 		sbi->s_journal->j_commit_callback =
5020 			ext4_journal_commit_callback;
5021 
5022 	block = ext4_count_free_clusters(sb);
5023 	ext4_free_blocks_count_set(sbi->s_es,
5024 				   EXT4_C2B(sbi, block));
5025 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5026 				  GFP_KERNEL);
5027 	if (!err) {
5028 		unsigned long freei = ext4_count_free_inodes(sb);
5029 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5030 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5031 					  GFP_KERNEL);
5032 	}
5033 	if (!err)
5034 		err = percpu_counter_init(&sbi->s_dirs_counter,
5035 					  ext4_count_dirs(sb), GFP_KERNEL);
5036 	if (!err)
5037 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5038 					  GFP_KERNEL);
5039 	if (!err)
5040 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5041 					  GFP_KERNEL);
5042 	if (!err)
5043 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5044 
5045 	if (err) {
5046 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5047 		goto failed_mount6;
5048 	}
5049 
5050 	if (ext4_has_feature_flex_bg(sb))
5051 		if (!ext4_fill_flex_info(sb)) {
5052 			ext4_msg(sb, KERN_ERR,
5053 			       "unable to initialize "
5054 			       "flex_bg meta info!");
5055 			goto failed_mount6;
5056 		}
5057 
5058 	err = ext4_register_li_request(sb, first_not_zeroed);
5059 	if (err)
5060 		goto failed_mount6;
5061 
5062 	err = ext4_register_sysfs(sb);
5063 	if (err)
5064 		goto failed_mount7;
5065 
5066 #ifdef CONFIG_QUOTA
5067 	/* Enable quota usage during mount. */
5068 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5069 		err = ext4_enable_quotas(sb);
5070 		if (err)
5071 			goto failed_mount8;
5072 	}
5073 #endif  /* CONFIG_QUOTA */
5074 
5075 	/*
5076 	 * Save the original bdev mapping's wb_err value which could be
5077 	 * used to detect the metadata async write error.
5078 	 */
5079 	spin_lock_init(&sbi->s_bdev_wb_lock);
5080 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5081 				 &sbi->s_bdev_wb_err);
5082 	sb->s_bdev->bd_super = sb;
5083 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5084 	ext4_orphan_cleanup(sb, es);
5085 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5086 	if (needs_recovery) {
5087 		ext4_msg(sb, KERN_INFO, "recovery complete");
5088 		err = ext4_mark_recovery_complete(sb, es);
5089 		if (err)
5090 			goto failed_mount8;
5091 	}
5092 	if (EXT4_SB(sb)->s_journal) {
5093 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5094 			descr = " journalled data mode";
5095 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5096 			descr = " ordered data mode";
5097 		else
5098 			descr = " writeback data mode";
5099 	} else
5100 		descr = "out journal";
5101 
5102 	if (test_opt(sb, DISCARD)) {
5103 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5104 		if (!blk_queue_discard(q))
5105 			ext4_msg(sb, KERN_WARNING,
5106 				 "mounting with \"discard\" option, but "
5107 				 "the device does not support discard");
5108 	}
5109 
5110 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5111 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5112 			 "Opts: %.*s%s%s. Quota mode: %s.", descr,
5113 			 (int) sizeof(sbi->s_es->s_mount_opts),
5114 			 sbi->s_es->s_mount_opts,
5115 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data,
5116 			 ext4_quota_mode(sb));
5117 
5118 	if (es->s_error_count)
5119 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5120 
5121 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5122 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5123 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5124 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5125 	atomic_set(&sbi->s_warning_count, 0);
5126 	atomic_set(&sbi->s_msg_count, 0);
5127 
5128 	kfree(orig_data);
5129 	return 0;
5130 
5131 cantfind_ext4:
5132 	if (!silent)
5133 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5134 	goto failed_mount;
5135 
5136 failed_mount8:
5137 	ext4_unregister_sysfs(sb);
5138 	kobject_put(&sbi->s_kobj);
5139 failed_mount7:
5140 	ext4_unregister_li_request(sb);
5141 failed_mount6:
5142 	ext4_mb_release(sb);
5143 	rcu_read_lock();
5144 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5145 	if (flex_groups) {
5146 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5147 			kvfree(flex_groups[i]);
5148 		kvfree(flex_groups);
5149 	}
5150 	rcu_read_unlock();
5151 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5152 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5153 	percpu_counter_destroy(&sbi->s_dirs_counter);
5154 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5155 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5156 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5157 failed_mount5:
5158 	ext4_ext_release(sb);
5159 	ext4_release_system_zone(sb);
5160 failed_mount4a:
5161 	dput(sb->s_root);
5162 	sb->s_root = NULL;
5163 failed_mount4:
5164 	ext4_msg(sb, KERN_ERR, "mount failed");
5165 	if (EXT4_SB(sb)->rsv_conversion_wq)
5166 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5167 failed_mount_wq:
5168 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5169 	sbi->s_ea_inode_cache = NULL;
5170 
5171 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5172 	sbi->s_ea_block_cache = NULL;
5173 
5174 	if (sbi->s_journal) {
5175 		jbd2_journal_destroy(sbi->s_journal);
5176 		sbi->s_journal = NULL;
5177 	}
5178 failed_mount3a:
5179 	ext4_es_unregister_shrinker(sbi);
5180 failed_mount3:
5181 	flush_work(&sbi->s_error_work);
5182 	del_timer_sync(&sbi->s_err_report);
5183 	if (sbi->s_mmp_tsk)
5184 		kthread_stop(sbi->s_mmp_tsk);
5185 failed_mount2:
5186 	rcu_read_lock();
5187 	group_desc = rcu_dereference(sbi->s_group_desc);
5188 	for (i = 0; i < db_count; i++)
5189 		brelse(group_desc[i]);
5190 	kvfree(group_desc);
5191 	rcu_read_unlock();
5192 failed_mount:
5193 	if (sbi->s_chksum_driver)
5194 		crypto_free_shash(sbi->s_chksum_driver);
5195 
5196 #ifdef CONFIG_UNICODE
5197 	utf8_unload(sb->s_encoding);
5198 #endif
5199 
5200 #ifdef CONFIG_QUOTA
5201 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5202 		kfree(get_qf_name(sb, sbi, i));
5203 #endif
5204 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5205 	ext4_blkdev_remove(sbi);
5206 	brelse(bh);
5207 out_fail:
5208 	sb->s_fs_info = NULL;
5209 	kfree(sbi->s_blockgroup_lock);
5210 out_free_base:
5211 	kfree(sbi);
5212 	kfree(orig_data);
5213 	fs_put_dax(dax_dev);
5214 	return err ? err : ret;
5215 }
5216 
5217 /*
5218  * Setup any per-fs journal parameters now.  We'll do this both on
5219  * initial mount, once the journal has been initialised but before we've
5220  * done any recovery; and again on any subsequent remount.
5221  */
5222 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5223 {
5224 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5225 
5226 	journal->j_commit_interval = sbi->s_commit_interval;
5227 	journal->j_min_batch_time = sbi->s_min_batch_time;
5228 	journal->j_max_batch_time = sbi->s_max_batch_time;
5229 	ext4_fc_init(sb, journal);
5230 
5231 	write_lock(&journal->j_state_lock);
5232 	if (test_opt(sb, BARRIER))
5233 		journal->j_flags |= JBD2_BARRIER;
5234 	else
5235 		journal->j_flags &= ~JBD2_BARRIER;
5236 	if (test_opt(sb, DATA_ERR_ABORT))
5237 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5238 	else
5239 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5240 	write_unlock(&journal->j_state_lock);
5241 }
5242 
5243 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5244 					     unsigned int journal_inum)
5245 {
5246 	struct inode *journal_inode;
5247 
5248 	/*
5249 	 * Test for the existence of a valid inode on disk.  Bad things
5250 	 * happen if we iget() an unused inode, as the subsequent iput()
5251 	 * will try to delete it.
5252 	 */
5253 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5254 	if (IS_ERR(journal_inode)) {
5255 		ext4_msg(sb, KERN_ERR, "no journal found");
5256 		return NULL;
5257 	}
5258 	if (!journal_inode->i_nlink) {
5259 		make_bad_inode(journal_inode);
5260 		iput(journal_inode);
5261 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5262 		return NULL;
5263 	}
5264 
5265 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5266 		  journal_inode, journal_inode->i_size);
5267 	if (!S_ISREG(journal_inode->i_mode)) {
5268 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5269 		iput(journal_inode);
5270 		return NULL;
5271 	}
5272 	return journal_inode;
5273 }
5274 
5275 static journal_t *ext4_get_journal(struct super_block *sb,
5276 				   unsigned int journal_inum)
5277 {
5278 	struct inode *journal_inode;
5279 	journal_t *journal;
5280 
5281 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5282 		return NULL;
5283 
5284 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5285 	if (!journal_inode)
5286 		return NULL;
5287 
5288 	journal = jbd2_journal_init_inode(journal_inode);
5289 	if (!journal) {
5290 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5291 		iput(journal_inode);
5292 		return NULL;
5293 	}
5294 	journal->j_private = sb;
5295 	ext4_init_journal_params(sb, journal);
5296 	return journal;
5297 }
5298 
5299 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5300 				       dev_t j_dev)
5301 {
5302 	struct buffer_head *bh;
5303 	journal_t *journal;
5304 	ext4_fsblk_t start;
5305 	ext4_fsblk_t len;
5306 	int hblock, blocksize;
5307 	ext4_fsblk_t sb_block;
5308 	unsigned long offset;
5309 	struct ext4_super_block *es;
5310 	struct block_device *bdev;
5311 
5312 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5313 		return NULL;
5314 
5315 	bdev = ext4_blkdev_get(j_dev, sb);
5316 	if (bdev == NULL)
5317 		return NULL;
5318 
5319 	blocksize = sb->s_blocksize;
5320 	hblock = bdev_logical_block_size(bdev);
5321 	if (blocksize < hblock) {
5322 		ext4_msg(sb, KERN_ERR,
5323 			"blocksize too small for journal device");
5324 		goto out_bdev;
5325 	}
5326 
5327 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5328 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5329 	set_blocksize(bdev, blocksize);
5330 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5331 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5332 		       "external journal");
5333 		goto out_bdev;
5334 	}
5335 
5336 	es = (struct ext4_super_block *) (bh->b_data + offset);
5337 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5338 	    !(le32_to_cpu(es->s_feature_incompat) &
5339 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5340 		ext4_msg(sb, KERN_ERR, "external journal has "
5341 					"bad superblock");
5342 		brelse(bh);
5343 		goto out_bdev;
5344 	}
5345 
5346 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5347 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5348 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5349 		ext4_msg(sb, KERN_ERR, "external journal has "
5350 				       "corrupt superblock");
5351 		brelse(bh);
5352 		goto out_bdev;
5353 	}
5354 
5355 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5356 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5357 		brelse(bh);
5358 		goto out_bdev;
5359 	}
5360 
5361 	len = ext4_blocks_count(es);
5362 	start = sb_block + 1;
5363 	brelse(bh);	/* we're done with the superblock */
5364 
5365 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5366 					start, len, blocksize);
5367 	if (!journal) {
5368 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5369 		goto out_bdev;
5370 	}
5371 	journal->j_private = sb;
5372 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5373 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5374 		goto out_journal;
5375 	}
5376 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5377 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5378 					"user (unsupported) - %d",
5379 			be32_to_cpu(journal->j_superblock->s_nr_users));
5380 		goto out_journal;
5381 	}
5382 	EXT4_SB(sb)->s_journal_bdev = bdev;
5383 	ext4_init_journal_params(sb, journal);
5384 	return journal;
5385 
5386 out_journal:
5387 	jbd2_journal_destroy(journal);
5388 out_bdev:
5389 	ext4_blkdev_put(bdev);
5390 	return NULL;
5391 }
5392 
5393 static int ext4_load_journal(struct super_block *sb,
5394 			     struct ext4_super_block *es,
5395 			     unsigned long journal_devnum)
5396 {
5397 	journal_t *journal;
5398 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5399 	dev_t journal_dev;
5400 	int err = 0;
5401 	int really_read_only;
5402 	int journal_dev_ro;
5403 
5404 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5405 		return -EFSCORRUPTED;
5406 
5407 	if (journal_devnum &&
5408 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5409 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5410 			"numbers have changed");
5411 		journal_dev = new_decode_dev(journal_devnum);
5412 	} else
5413 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5414 
5415 	if (journal_inum && journal_dev) {
5416 		ext4_msg(sb, KERN_ERR,
5417 			 "filesystem has both journal inode and journal device!");
5418 		return -EINVAL;
5419 	}
5420 
5421 	if (journal_inum) {
5422 		journal = ext4_get_journal(sb, journal_inum);
5423 		if (!journal)
5424 			return -EINVAL;
5425 	} else {
5426 		journal = ext4_get_dev_journal(sb, journal_dev);
5427 		if (!journal)
5428 			return -EINVAL;
5429 	}
5430 
5431 	journal_dev_ro = bdev_read_only(journal->j_dev);
5432 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5433 
5434 	if (journal_dev_ro && !sb_rdonly(sb)) {
5435 		ext4_msg(sb, KERN_ERR,
5436 			 "journal device read-only, try mounting with '-o ro'");
5437 		err = -EROFS;
5438 		goto err_out;
5439 	}
5440 
5441 	/*
5442 	 * Are we loading a blank journal or performing recovery after a
5443 	 * crash?  For recovery, we need to check in advance whether we
5444 	 * can get read-write access to the device.
5445 	 */
5446 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5447 		if (sb_rdonly(sb)) {
5448 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5449 					"required on readonly filesystem");
5450 			if (really_read_only) {
5451 				ext4_msg(sb, KERN_ERR, "write access "
5452 					"unavailable, cannot proceed "
5453 					"(try mounting with noload)");
5454 				err = -EROFS;
5455 				goto err_out;
5456 			}
5457 			ext4_msg(sb, KERN_INFO, "write access will "
5458 			       "be enabled during recovery");
5459 		}
5460 	}
5461 
5462 	if (!(journal->j_flags & JBD2_BARRIER))
5463 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5464 
5465 	if (!ext4_has_feature_journal_needs_recovery(sb))
5466 		err = jbd2_journal_wipe(journal, !really_read_only);
5467 	if (!err) {
5468 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5469 		if (save)
5470 			memcpy(save, ((char *) es) +
5471 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5472 		err = jbd2_journal_load(journal);
5473 		if (save)
5474 			memcpy(((char *) es) + EXT4_S_ERR_START,
5475 			       save, EXT4_S_ERR_LEN);
5476 		kfree(save);
5477 	}
5478 
5479 	if (err) {
5480 		ext4_msg(sb, KERN_ERR, "error loading journal");
5481 		goto err_out;
5482 	}
5483 
5484 	EXT4_SB(sb)->s_journal = journal;
5485 	err = ext4_clear_journal_err(sb, es);
5486 	if (err) {
5487 		EXT4_SB(sb)->s_journal = NULL;
5488 		jbd2_journal_destroy(journal);
5489 		return err;
5490 	}
5491 
5492 	if (!really_read_only && journal_devnum &&
5493 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5494 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5495 
5496 		/* Make sure we flush the recovery flag to disk. */
5497 		ext4_commit_super(sb);
5498 	}
5499 
5500 	return 0;
5501 
5502 err_out:
5503 	jbd2_journal_destroy(journal);
5504 	return err;
5505 }
5506 
5507 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5508 static void ext4_update_super(struct super_block *sb)
5509 {
5510 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5511 	struct ext4_super_block *es = sbi->s_es;
5512 	struct buffer_head *sbh = sbi->s_sbh;
5513 
5514 	lock_buffer(sbh);
5515 	/*
5516 	 * If the file system is mounted read-only, don't update the
5517 	 * superblock write time.  This avoids updating the superblock
5518 	 * write time when we are mounting the root file system
5519 	 * read/only but we need to replay the journal; at that point,
5520 	 * for people who are east of GMT and who make their clock
5521 	 * tick in localtime for Windows bug-for-bug compatibility,
5522 	 * the clock is set in the future, and this will cause e2fsck
5523 	 * to complain and force a full file system check.
5524 	 */
5525 	if (!(sb->s_flags & SB_RDONLY))
5526 		ext4_update_tstamp(es, s_wtime);
5527 	es->s_kbytes_written =
5528 		cpu_to_le64(sbi->s_kbytes_written +
5529 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5530 		      sbi->s_sectors_written_start) >> 1));
5531 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5532 		ext4_free_blocks_count_set(es,
5533 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5534 				&sbi->s_freeclusters_counter)));
5535 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5536 		es->s_free_inodes_count =
5537 			cpu_to_le32(percpu_counter_sum_positive(
5538 				&sbi->s_freeinodes_counter));
5539 	/* Copy error information to the on-disk superblock */
5540 	spin_lock(&sbi->s_error_lock);
5541 	if (sbi->s_add_error_count > 0) {
5542 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5543 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5544 			__ext4_update_tstamp(&es->s_first_error_time,
5545 					     &es->s_first_error_time_hi,
5546 					     sbi->s_first_error_time);
5547 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5548 				sizeof(es->s_first_error_func));
5549 			es->s_first_error_line =
5550 				cpu_to_le32(sbi->s_first_error_line);
5551 			es->s_first_error_ino =
5552 				cpu_to_le32(sbi->s_first_error_ino);
5553 			es->s_first_error_block =
5554 				cpu_to_le64(sbi->s_first_error_block);
5555 			es->s_first_error_errcode =
5556 				ext4_errno_to_code(sbi->s_first_error_code);
5557 		}
5558 		__ext4_update_tstamp(&es->s_last_error_time,
5559 				     &es->s_last_error_time_hi,
5560 				     sbi->s_last_error_time);
5561 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5562 			sizeof(es->s_last_error_func));
5563 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5564 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5565 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5566 		es->s_last_error_errcode =
5567 				ext4_errno_to_code(sbi->s_last_error_code);
5568 		/*
5569 		 * Start the daily error reporting function if it hasn't been
5570 		 * started already
5571 		 */
5572 		if (!es->s_error_count)
5573 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5574 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5575 		sbi->s_add_error_count = 0;
5576 	}
5577 	spin_unlock(&sbi->s_error_lock);
5578 
5579 	ext4_superblock_csum_set(sb);
5580 	unlock_buffer(sbh);
5581 }
5582 
5583 static int ext4_commit_super(struct super_block *sb)
5584 {
5585 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5586 	int error = 0;
5587 
5588 	if (!sbh)
5589 		return -EINVAL;
5590 	if (block_device_ejected(sb))
5591 		return -ENODEV;
5592 
5593 	ext4_update_super(sb);
5594 
5595 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5596 		/*
5597 		 * Oh, dear.  A previous attempt to write the
5598 		 * superblock failed.  This could happen because the
5599 		 * USB device was yanked out.  Or it could happen to
5600 		 * be a transient write error and maybe the block will
5601 		 * be remapped.  Nothing we can do but to retry the
5602 		 * write and hope for the best.
5603 		 */
5604 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5605 		       "superblock detected");
5606 		clear_buffer_write_io_error(sbh);
5607 		set_buffer_uptodate(sbh);
5608 	}
5609 	BUFFER_TRACE(sbh, "marking dirty");
5610 	mark_buffer_dirty(sbh);
5611 	error = __sync_dirty_buffer(sbh,
5612 		REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5613 	if (buffer_write_io_error(sbh)) {
5614 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
5615 		       "superblock");
5616 		clear_buffer_write_io_error(sbh);
5617 		set_buffer_uptodate(sbh);
5618 	}
5619 	return error;
5620 }
5621 
5622 /*
5623  * Have we just finished recovery?  If so, and if we are mounting (or
5624  * remounting) the filesystem readonly, then we will end up with a
5625  * consistent fs on disk.  Record that fact.
5626  */
5627 static int ext4_mark_recovery_complete(struct super_block *sb,
5628 				       struct ext4_super_block *es)
5629 {
5630 	int err;
5631 	journal_t *journal = EXT4_SB(sb)->s_journal;
5632 
5633 	if (!ext4_has_feature_journal(sb)) {
5634 		if (journal != NULL) {
5635 			ext4_error(sb, "Journal got removed while the fs was "
5636 				   "mounted!");
5637 			return -EFSCORRUPTED;
5638 		}
5639 		return 0;
5640 	}
5641 	jbd2_journal_lock_updates(journal);
5642 	err = jbd2_journal_flush(journal);
5643 	if (err < 0)
5644 		goto out;
5645 
5646 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5647 		ext4_clear_feature_journal_needs_recovery(sb);
5648 		ext4_commit_super(sb);
5649 	}
5650 out:
5651 	jbd2_journal_unlock_updates(journal);
5652 	return err;
5653 }
5654 
5655 /*
5656  * If we are mounting (or read-write remounting) a filesystem whose journal
5657  * has recorded an error from a previous lifetime, move that error to the
5658  * main filesystem now.
5659  */
5660 static int ext4_clear_journal_err(struct super_block *sb,
5661 				   struct ext4_super_block *es)
5662 {
5663 	journal_t *journal;
5664 	int j_errno;
5665 	const char *errstr;
5666 
5667 	if (!ext4_has_feature_journal(sb)) {
5668 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5669 		return -EFSCORRUPTED;
5670 	}
5671 
5672 	journal = EXT4_SB(sb)->s_journal;
5673 
5674 	/*
5675 	 * Now check for any error status which may have been recorded in the
5676 	 * journal by a prior ext4_error() or ext4_abort()
5677 	 */
5678 
5679 	j_errno = jbd2_journal_errno(journal);
5680 	if (j_errno) {
5681 		char nbuf[16];
5682 
5683 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5684 		ext4_warning(sb, "Filesystem error recorded "
5685 			     "from previous mount: %s", errstr);
5686 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5687 
5688 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5689 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5690 		ext4_commit_super(sb);
5691 
5692 		jbd2_journal_clear_err(journal);
5693 		jbd2_journal_update_sb_errno(journal);
5694 	}
5695 	return 0;
5696 }
5697 
5698 /*
5699  * Force the running and committing transactions to commit,
5700  * and wait on the commit.
5701  */
5702 int ext4_force_commit(struct super_block *sb)
5703 {
5704 	journal_t *journal;
5705 
5706 	if (sb_rdonly(sb))
5707 		return 0;
5708 
5709 	journal = EXT4_SB(sb)->s_journal;
5710 	return ext4_journal_force_commit(journal);
5711 }
5712 
5713 static int ext4_sync_fs(struct super_block *sb, int wait)
5714 {
5715 	int ret = 0;
5716 	tid_t target;
5717 	bool needs_barrier = false;
5718 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5719 
5720 	if (unlikely(ext4_forced_shutdown(sbi)))
5721 		return 0;
5722 
5723 	trace_ext4_sync_fs(sb, wait);
5724 	flush_workqueue(sbi->rsv_conversion_wq);
5725 	/*
5726 	 * Writeback quota in non-journalled quota case - journalled quota has
5727 	 * no dirty dquots
5728 	 */
5729 	dquot_writeback_dquots(sb, -1);
5730 	/*
5731 	 * Data writeback is possible w/o journal transaction, so barrier must
5732 	 * being sent at the end of the function. But we can skip it if
5733 	 * transaction_commit will do it for us.
5734 	 */
5735 	if (sbi->s_journal) {
5736 		target = jbd2_get_latest_transaction(sbi->s_journal);
5737 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5738 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5739 			needs_barrier = true;
5740 
5741 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5742 			if (wait)
5743 				ret = jbd2_log_wait_commit(sbi->s_journal,
5744 							   target);
5745 		}
5746 	} else if (wait && test_opt(sb, BARRIER))
5747 		needs_barrier = true;
5748 	if (needs_barrier) {
5749 		int err;
5750 		err = blkdev_issue_flush(sb->s_bdev);
5751 		if (!ret)
5752 			ret = err;
5753 	}
5754 
5755 	return ret;
5756 }
5757 
5758 /*
5759  * LVM calls this function before a (read-only) snapshot is created.  This
5760  * gives us a chance to flush the journal completely and mark the fs clean.
5761  *
5762  * Note that only this function cannot bring a filesystem to be in a clean
5763  * state independently. It relies on upper layer to stop all data & metadata
5764  * modifications.
5765  */
5766 static int ext4_freeze(struct super_block *sb)
5767 {
5768 	int error = 0;
5769 	journal_t *journal;
5770 
5771 	if (sb_rdonly(sb))
5772 		return 0;
5773 
5774 	journal = EXT4_SB(sb)->s_journal;
5775 
5776 	if (journal) {
5777 		/* Now we set up the journal barrier. */
5778 		jbd2_journal_lock_updates(journal);
5779 
5780 		/*
5781 		 * Don't clear the needs_recovery flag if we failed to
5782 		 * flush the journal.
5783 		 */
5784 		error = jbd2_journal_flush(journal);
5785 		if (error < 0)
5786 			goto out;
5787 
5788 		/* Journal blocked and flushed, clear needs_recovery flag. */
5789 		ext4_clear_feature_journal_needs_recovery(sb);
5790 	}
5791 
5792 	error = ext4_commit_super(sb);
5793 out:
5794 	if (journal)
5795 		/* we rely on upper layer to stop further updates */
5796 		jbd2_journal_unlock_updates(journal);
5797 	return error;
5798 }
5799 
5800 /*
5801  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5802  * flag here, even though the filesystem is not technically dirty yet.
5803  */
5804 static int ext4_unfreeze(struct super_block *sb)
5805 {
5806 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5807 		return 0;
5808 
5809 	if (EXT4_SB(sb)->s_journal) {
5810 		/* Reset the needs_recovery flag before the fs is unlocked. */
5811 		ext4_set_feature_journal_needs_recovery(sb);
5812 	}
5813 
5814 	ext4_commit_super(sb);
5815 	return 0;
5816 }
5817 
5818 /*
5819  * Structure to save mount options for ext4_remount's benefit
5820  */
5821 struct ext4_mount_options {
5822 	unsigned long s_mount_opt;
5823 	unsigned long s_mount_opt2;
5824 	kuid_t s_resuid;
5825 	kgid_t s_resgid;
5826 	unsigned long s_commit_interval;
5827 	u32 s_min_batch_time, s_max_batch_time;
5828 #ifdef CONFIG_QUOTA
5829 	int s_jquota_fmt;
5830 	char *s_qf_names[EXT4_MAXQUOTAS];
5831 #endif
5832 };
5833 
5834 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5835 {
5836 	struct ext4_super_block *es;
5837 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5838 	unsigned long old_sb_flags, vfs_flags;
5839 	struct ext4_mount_options old_opts;
5840 	int enable_quota = 0;
5841 	ext4_group_t g;
5842 	int err = 0;
5843 #ifdef CONFIG_QUOTA
5844 	int i, j;
5845 	char *to_free[EXT4_MAXQUOTAS];
5846 #endif
5847 	char *orig_data = kstrdup(data, GFP_KERNEL);
5848 	struct ext4_parsed_options parsed_opts;
5849 
5850 	parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5851 	parsed_opts.journal_devnum = 0;
5852 
5853 	if (data && !orig_data)
5854 		return -ENOMEM;
5855 
5856 	/* Store the original options */
5857 	old_sb_flags = sb->s_flags;
5858 	old_opts.s_mount_opt = sbi->s_mount_opt;
5859 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5860 	old_opts.s_resuid = sbi->s_resuid;
5861 	old_opts.s_resgid = sbi->s_resgid;
5862 	old_opts.s_commit_interval = sbi->s_commit_interval;
5863 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5864 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5865 #ifdef CONFIG_QUOTA
5866 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5867 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5868 		if (sbi->s_qf_names[i]) {
5869 			char *qf_name = get_qf_name(sb, sbi, i);
5870 
5871 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5872 			if (!old_opts.s_qf_names[i]) {
5873 				for (j = 0; j < i; j++)
5874 					kfree(old_opts.s_qf_names[j]);
5875 				kfree(orig_data);
5876 				return -ENOMEM;
5877 			}
5878 		} else
5879 			old_opts.s_qf_names[i] = NULL;
5880 #endif
5881 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5882 		parsed_opts.journal_ioprio =
5883 			sbi->s_journal->j_task->io_context->ioprio;
5884 
5885 	/*
5886 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5887 	 * either way we need to make sure it matches in both *flags and
5888 	 * s_flags. Copy those selected flags from *flags to s_flags
5889 	 */
5890 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5891 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5892 
5893 	if (!parse_options(data, sb, &parsed_opts, 1)) {
5894 		err = -EINVAL;
5895 		goto restore_opts;
5896 	}
5897 
5898 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5899 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5900 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5901 			 "during remount not supported; ignoring");
5902 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5903 	}
5904 
5905 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5906 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5907 			ext4_msg(sb, KERN_ERR, "can't mount with "
5908 				 "both data=journal and delalloc");
5909 			err = -EINVAL;
5910 			goto restore_opts;
5911 		}
5912 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5913 			ext4_msg(sb, KERN_ERR, "can't mount with "
5914 				 "both data=journal and dioread_nolock");
5915 			err = -EINVAL;
5916 			goto restore_opts;
5917 		}
5918 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5919 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5920 			ext4_msg(sb, KERN_ERR, "can't mount with "
5921 				"journal_async_commit in data=ordered mode");
5922 			err = -EINVAL;
5923 			goto restore_opts;
5924 		}
5925 	}
5926 
5927 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5928 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5929 		err = -EINVAL;
5930 		goto restore_opts;
5931 	}
5932 
5933 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5934 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5935 
5936 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5937 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5938 
5939 	es = sbi->s_es;
5940 
5941 	if (sbi->s_journal) {
5942 		ext4_init_journal_params(sb, sbi->s_journal);
5943 		set_task_ioprio(sbi->s_journal->j_task, parsed_opts.journal_ioprio);
5944 	}
5945 
5946 	/* Flush outstanding errors before changing fs state */
5947 	flush_work(&sbi->s_error_work);
5948 
5949 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5950 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
5951 			err = -EROFS;
5952 			goto restore_opts;
5953 		}
5954 
5955 		if (*flags & SB_RDONLY) {
5956 			err = sync_filesystem(sb);
5957 			if (err < 0)
5958 				goto restore_opts;
5959 			err = dquot_suspend(sb, -1);
5960 			if (err < 0)
5961 				goto restore_opts;
5962 
5963 			/*
5964 			 * First of all, the unconditional stuff we have to do
5965 			 * to disable replay of the journal when we next remount
5966 			 */
5967 			sb->s_flags |= SB_RDONLY;
5968 
5969 			/*
5970 			 * OK, test if we are remounting a valid rw partition
5971 			 * readonly, and if so set the rdonly flag and then
5972 			 * mark the partition as valid again.
5973 			 */
5974 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5975 			    (sbi->s_mount_state & EXT4_VALID_FS))
5976 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5977 
5978 			if (sbi->s_journal) {
5979 				/*
5980 				 * We let remount-ro finish even if marking fs
5981 				 * as clean failed...
5982 				 */
5983 				ext4_mark_recovery_complete(sb, es);
5984 			}
5985 			if (sbi->s_mmp_tsk)
5986 				kthread_stop(sbi->s_mmp_tsk);
5987 		} else {
5988 			/* Make sure we can mount this feature set readwrite */
5989 			if (ext4_has_feature_readonly(sb) ||
5990 			    !ext4_feature_set_ok(sb, 0)) {
5991 				err = -EROFS;
5992 				goto restore_opts;
5993 			}
5994 			/*
5995 			 * Make sure the group descriptor checksums
5996 			 * are sane.  If they aren't, refuse to remount r/w.
5997 			 */
5998 			for (g = 0; g < sbi->s_groups_count; g++) {
5999 				struct ext4_group_desc *gdp =
6000 					ext4_get_group_desc(sb, g, NULL);
6001 
6002 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6003 					ext4_msg(sb, KERN_ERR,
6004 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6005 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6006 					       le16_to_cpu(gdp->bg_checksum));
6007 					err = -EFSBADCRC;
6008 					goto restore_opts;
6009 				}
6010 			}
6011 
6012 			/*
6013 			 * If we have an unprocessed orphan list hanging
6014 			 * around from a previously readonly bdev mount,
6015 			 * require a full umount/remount for now.
6016 			 */
6017 			if (es->s_last_orphan) {
6018 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6019 				       "remount RDWR because of unprocessed "
6020 				       "orphan inode list.  Please "
6021 				       "umount/remount instead");
6022 				err = -EINVAL;
6023 				goto restore_opts;
6024 			}
6025 
6026 			/*
6027 			 * Mounting a RDONLY partition read-write, so reread
6028 			 * and store the current valid flag.  (It may have
6029 			 * been changed by e2fsck since we originally mounted
6030 			 * the partition.)
6031 			 */
6032 			if (sbi->s_journal) {
6033 				err = ext4_clear_journal_err(sb, es);
6034 				if (err)
6035 					goto restore_opts;
6036 			}
6037 			sbi->s_mount_state = le16_to_cpu(es->s_state);
6038 
6039 			err = ext4_setup_super(sb, es, 0);
6040 			if (err)
6041 				goto restore_opts;
6042 
6043 			sb->s_flags &= ~SB_RDONLY;
6044 			if (ext4_has_feature_mmp(sb))
6045 				if (ext4_multi_mount_protect(sb,
6046 						le64_to_cpu(es->s_mmp_block))) {
6047 					err = -EROFS;
6048 					goto restore_opts;
6049 				}
6050 			enable_quota = 1;
6051 		}
6052 	}
6053 
6054 	/*
6055 	 * Reinitialize lazy itable initialization thread based on
6056 	 * current settings
6057 	 */
6058 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6059 		ext4_unregister_li_request(sb);
6060 	else {
6061 		ext4_group_t first_not_zeroed;
6062 		first_not_zeroed = ext4_has_uninit_itable(sb);
6063 		ext4_register_li_request(sb, first_not_zeroed);
6064 	}
6065 
6066 	/*
6067 	 * Handle creation of system zone data early because it can fail.
6068 	 * Releasing of existing data is done when we are sure remount will
6069 	 * succeed.
6070 	 */
6071 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6072 		err = ext4_setup_system_zone(sb);
6073 		if (err)
6074 			goto restore_opts;
6075 	}
6076 
6077 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6078 		err = ext4_commit_super(sb);
6079 		if (err)
6080 			goto restore_opts;
6081 	}
6082 
6083 #ifdef CONFIG_QUOTA
6084 	/* Release old quota file names */
6085 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6086 		kfree(old_opts.s_qf_names[i]);
6087 	if (enable_quota) {
6088 		if (sb_any_quota_suspended(sb))
6089 			dquot_resume(sb, -1);
6090 		else if (ext4_has_feature_quota(sb)) {
6091 			err = ext4_enable_quotas(sb);
6092 			if (err)
6093 				goto restore_opts;
6094 		}
6095 	}
6096 #endif
6097 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6098 		ext4_release_system_zone(sb);
6099 
6100 	/*
6101 	 * Some options can be enabled by ext4 and/or by VFS mount flag
6102 	 * either way we need to make sure it matches in both *flags and
6103 	 * s_flags. Copy those selected flags from s_flags to *flags
6104 	 */
6105 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6106 
6107 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s. Quota mode: %s.",
6108 		 orig_data, ext4_quota_mode(sb));
6109 	kfree(orig_data);
6110 	return 0;
6111 
6112 restore_opts:
6113 	sb->s_flags = old_sb_flags;
6114 	sbi->s_mount_opt = old_opts.s_mount_opt;
6115 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6116 	sbi->s_resuid = old_opts.s_resuid;
6117 	sbi->s_resgid = old_opts.s_resgid;
6118 	sbi->s_commit_interval = old_opts.s_commit_interval;
6119 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6120 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6121 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6122 		ext4_release_system_zone(sb);
6123 #ifdef CONFIG_QUOTA
6124 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6125 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6126 		to_free[i] = get_qf_name(sb, sbi, i);
6127 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6128 	}
6129 	synchronize_rcu();
6130 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6131 		kfree(to_free[i]);
6132 #endif
6133 	kfree(orig_data);
6134 	return err;
6135 }
6136 
6137 #ifdef CONFIG_QUOTA
6138 static int ext4_statfs_project(struct super_block *sb,
6139 			       kprojid_t projid, struct kstatfs *buf)
6140 {
6141 	struct kqid qid;
6142 	struct dquot *dquot;
6143 	u64 limit;
6144 	u64 curblock;
6145 
6146 	qid = make_kqid_projid(projid);
6147 	dquot = dqget(sb, qid);
6148 	if (IS_ERR(dquot))
6149 		return PTR_ERR(dquot);
6150 	spin_lock(&dquot->dq_dqb_lock);
6151 
6152 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6153 			     dquot->dq_dqb.dqb_bhardlimit);
6154 	limit >>= sb->s_blocksize_bits;
6155 
6156 	if (limit && buf->f_blocks > limit) {
6157 		curblock = (dquot->dq_dqb.dqb_curspace +
6158 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6159 		buf->f_blocks = limit;
6160 		buf->f_bfree = buf->f_bavail =
6161 			(buf->f_blocks > curblock) ?
6162 			 (buf->f_blocks - curblock) : 0;
6163 	}
6164 
6165 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6166 			     dquot->dq_dqb.dqb_ihardlimit);
6167 	if (limit && buf->f_files > limit) {
6168 		buf->f_files = limit;
6169 		buf->f_ffree =
6170 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6171 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6172 	}
6173 
6174 	spin_unlock(&dquot->dq_dqb_lock);
6175 	dqput(dquot);
6176 	return 0;
6177 }
6178 #endif
6179 
6180 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6181 {
6182 	struct super_block *sb = dentry->d_sb;
6183 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6184 	struct ext4_super_block *es = sbi->s_es;
6185 	ext4_fsblk_t overhead = 0, resv_blocks;
6186 	s64 bfree;
6187 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6188 
6189 	if (!test_opt(sb, MINIX_DF))
6190 		overhead = sbi->s_overhead;
6191 
6192 	buf->f_type = EXT4_SUPER_MAGIC;
6193 	buf->f_bsize = sb->s_blocksize;
6194 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6195 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6196 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6197 	/* prevent underflow in case that few free space is available */
6198 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6199 	buf->f_bavail = buf->f_bfree -
6200 			(ext4_r_blocks_count(es) + resv_blocks);
6201 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6202 		buf->f_bavail = 0;
6203 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6204 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6205 	buf->f_namelen = EXT4_NAME_LEN;
6206 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6207 
6208 #ifdef CONFIG_QUOTA
6209 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6210 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6211 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6212 #endif
6213 	return 0;
6214 }
6215 
6216 
6217 #ifdef CONFIG_QUOTA
6218 
6219 /*
6220  * Helper functions so that transaction is started before we acquire dqio_sem
6221  * to keep correct lock ordering of transaction > dqio_sem
6222  */
6223 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6224 {
6225 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6226 }
6227 
6228 static int ext4_write_dquot(struct dquot *dquot)
6229 {
6230 	int ret, err;
6231 	handle_t *handle;
6232 	struct inode *inode;
6233 
6234 	inode = dquot_to_inode(dquot);
6235 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6236 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6237 	if (IS_ERR(handle))
6238 		return PTR_ERR(handle);
6239 	ret = dquot_commit(dquot);
6240 	err = ext4_journal_stop(handle);
6241 	if (!ret)
6242 		ret = err;
6243 	return ret;
6244 }
6245 
6246 static int ext4_acquire_dquot(struct dquot *dquot)
6247 {
6248 	int ret, err;
6249 	handle_t *handle;
6250 
6251 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6252 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6253 	if (IS_ERR(handle))
6254 		return PTR_ERR(handle);
6255 	ret = dquot_acquire(dquot);
6256 	err = ext4_journal_stop(handle);
6257 	if (!ret)
6258 		ret = err;
6259 	return ret;
6260 }
6261 
6262 static int ext4_release_dquot(struct dquot *dquot)
6263 {
6264 	int ret, err;
6265 	handle_t *handle;
6266 
6267 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6268 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6269 	if (IS_ERR(handle)) {
6270 		/* Release dquot anyway to avoid endless cycle in dqput() */
6271 		dquot_release(dquot);
6272 		return PTR_ERR(handle);
6273 	}
6274 	ret = dquot_release(dquot);
6275 	err = ext4_journal_stop(handle);
6276 	if (!ret)
6277 		ret = err;
6278 	return ret;
6279 }
6280 
6281 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6282 {
6283 	struct super_block *sb = dquot->dq_sb;
6284 
6285 	if (ext4_is_quota_journalled(sb)) {
6286 		dquot_mark_dquot_dirty(dquot);
6287 		return ext4_write_dquot(dquot);
6288 	} else {
6289 		return dquot_mark_dquot_dirty(dquot);
6290 	}
6291 }
6292 
6293 static int ext4_write_info(struct super_block *sb, int type)
6294 {
6295 	int ret, err;
6296 	handle_t *handle;
6297 
6298 	/* Data block + inode block */
6299 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6300 	if (IS_ERR(handle))
6301 		return PTR_ERR(handle);
6302 	ret = dquot_commit_info(sb, type);
6303 	err = ext4_journal_stop(handle);
6304 	if (!ret)
6305 		ret = err;
6306 	return ret;
6307 }
6308 
6309 /*
6310  * Turn on quotas during mount time - we need to find
6311  * the quota file and such...
6312  */
6313 static int ext4_quota_on_mount(struct super_block *sb, int type)
6314 {
6315 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6316 					EXT4_SB(sb)->s_jquota_fmt, type);
6317 }
6318 
6319 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6320 {
6321 	struct ext4_inode_info *ei = EXT4_I(inode);
6322 
6323 	/* The first argument of lockdep_set_subclass has to be
6324 	 * *exactly* the same as the argument to init_rwsem() --- in
6325 	 * this case, in init_once() --- or lockdep gets unhappy
6326 	 * because the name of the lock is set using the
6327 	 * stringification of the argument to init_rwsem().
6328 	 */
6329 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6330 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6331 }
6332 
6333 /*
6334  * Standard function to be called on quota_on
6335  */
6336 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6337 			 const struct path *path)
6338 {
6339 	int err;
6340 
6341 	if (!test_opt(sb, QUOTA))
6342 		return -EINVAL;
6343 
6344 	/* Quotafile not on the same filesystem? */
6345 	if (path->dentry->d_sb != sb)
6346 		return -EXDEV;
6347 
6348 	/* Quota already enabled for this file? */
6349 	if (IS_NOQUOTA(d_inode(path->dentry)))
6350 		return -EBUSY;
6351 
6352 	/* Journaling quota? */
6353 	if (EXT4_SB(sb)->s_qf_names[type]) {
6354 		/* Quotafile not in fs root? */
6355 		if (path->dentry->d_parent != sb->s_root)
6356 			ext4_msg(sb, KERN_WARNING,
6357 				"Quota file not on filesystem root. "
6358 				"Journaled quota will not work");
6359 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6360 	} else {
6361 		/*
6362 		 * Clear the flag just in case mount options changed since
6363 		 * last time.
6364 		 */
6365 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6366 	}
6367 
6368 	/*
6369 	 * When we journal data on quota file, we have to flush journal to see
6370 	 * all updates to the file when we bypass pagecache...
6371 	 */
6372 	if (EXT4_SB(sb)->s_journal &&
6373 	    ext4_should_journal_data(d_inode(path->dentry))) {
6374 		/*
6375 		 * We don't need to lock updates but journal_flush() could
6376 		 * otherwise be livelocked...
6377 		 */
6378 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6379 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
6380 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6381 		if (err)
6382 			return err;
6383 	}
6384 
6385 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6386 	err = dquot_quota_on(sb, type, format_id, path);
6387 	if (err) {
6388 		lockdep_set_quota_inode(path->dentry->d_inode,
6389 					     I_DATA_SEM_NORMAL);
6390 	} else {
6391 		struct inode *inode = d_inode(path->dentry);
6392 		handle_t *handle;
6393 
6394 		/*
6395 		 * Set inode flags to prevent userspace from messing with quota
6396 		 * files. If this fails, we return success anyway since quotas
6397 		 * are already enabled and this is not a hard failure.
6398 		 */
6399 		inode_lock(inode);
6400 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6401 		if (IS_ERR(handle))
6402 			goto unlock_inode;
6403 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6404 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6405 				S_NOATIME | S_IMMUTABLE);
6406 		err = ext4_mark_inode_dirty(handle, inode);
6407 		ext4_journal_stop(handle);
6408 	unlock_inode:
6409 		inode_unlock(inode);
6410 	}
6411 	return err;
6412 }
6413 
6414 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6415 			     unsigned int flags)
6416 {
6417 	int err;
6418 	struct inode *qf_inode;
6419 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6420 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6421 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6422 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6423 	};
6424 
6425 	BUG_ON(!ext4_has_feature_quota(sb));
6426 
6427 	if (!qf_inums[type])
6428 		return -EPERM;
6429 
6430 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6431 	if (IS_ERR(qf_inode)) {
6432 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6433 		return PTR_ERR(qf_inode);
6434 	}
6435 
6436 	/* Don't account quota for quota files to avoid recursion */
6437 	qf_inode->i_flags |= S_NOQUOTA;
6438 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6439 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6440 	if (err)
6441 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6442 	iput(qf_inode);
6443 
6444 	return err;
6445 }
6446 
6447 /* Enable usage tracking for all quota types. */
6448 static int ext4_enable_quotas(struct super_block *sb)
6449 {
6450 	int type, err = 0;
6451 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6452 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6453 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6454 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6455 	};
6456 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6457 		test_opt(sb, USRQUOTA),
6458 		test_opt(sb, GRPQUOTA),
6459 		test_opt(sb, PRJQUOTA),
6460 	};
6461 
6462 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6463 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6464 		if (qf_inums[type]) {
6465 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6466 				DQUOT_USAGE_ENABLED |
6467 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6468 			if (err) {
6469 				ext4_warning(sb,
6470 					"Failed to enable quota tracking "
6471 					"(type=%d, err=%d). Please run "
6472 					"e2fsck to fix.", type, err);
6473 				for (type--; type >= 0; type--)
6474 					dquot_quota_off(sb, type);
6475 
6476 				return err;
6477 			}
6478 		}
6479 	}
6480 	return 0;
6481 }
6482 
6483 static int ext4_quota_off(struct super_block *sb, int type)
6484 {
6485 	struct inode *inode = sb_dqopt(sb)->files[type];
6486 	handle_t *handle;
6487 	int err;
6488 
6489 	/* Force all delayed allocation blocks to be allocated.
6490 	 * Caller already holds s_umount sem */
6491 	if (test_opt(sb, DELALLOC))
6492 		sync_filesystem(sb);
6493 
6494 	if (!inode || !igrab(inode))
6495 		goto out;
6496 
6497 	err = dquot_quota_off(sb, type);
6498 	if (err || ext4_has_feature_quota(sb))
6499 		goto out_put;
6500 
6501 	inode_lock(inode);
6502 	/*
6503 	 * Update modification times of quota files when userspace can
6504 	 * start looking at them. If we fail, we return success anyway since
6505 	 * this is not a hard failure and quotas are already disabled.
6506 	 */
6507 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6508 	if (IS_ERR(handle)) {
6509 		err = PTR_ERR(handle);
6510 		goto out_unlock;
6511 	}
6512 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6513 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6514 	inode->i_mtime = inode->i_ctime = current_time(inode);
6515 	err = ext4_mark_inode_dirty(handle, inode);
6516 	ext4_journal_stop(handle);
6517 out_unlock:
6518 	inode_unlock(inode);
6519 out_put:
6520 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6521 	iput(inode);
6522 	return err;
6523 out:
6524 	return dquot_quota_off(sb, type);
6525 }
6526 
6527 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6528  * acquiring the locks... As quota files are never truncated and quota code
6529  * itself serializes the operations (and no one else should touch the files)
6530  * we don't have to be afraid of races */
6531 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6532 			       size_t len, loff_t off)
6533 {
6534 	struct inode *inode = sb_dqopt(sb)->files[type];
6535 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6536 	int offset = off & (sb->s_blocksize - 1);
6537 	int tocopy;
6538 	size_t toread;
6539 	struct buffer_head *bh;
6540 	loff_t i_size = i_size_read(inode);
6541 
6542 	if (off > i_size)
6543 		return 0;
6544 	if (off+len > i_size)
6545 		len = i_size-off;
6546 	toread = len;
6547 	while (toread > 0) {
6548 		tocopy = sb->s_blocksize - offset < toread ?
6549 				sb->s_blocksize - offset : toread;
6550 		bh = ext4_bread(NULL, inode, blk, 0);
6551 		if (IS_ERR(bh))
6552 			return PTR_ERR(bh);
6553 		if (!bh)	/* A hole? */
6554 			memset(data, 0, tocopy);
6555 		else
6556 			memcpy(data, bh->b_data+offset, tocopy);
6557 		brelse(bh);
6558 		offset = 0;
6559 		toread -= tocopy;
6560 		data += tocopy;
6561 		blk++;
6562 	}
6563 	return len;
6564 }
6565 
6566 /* Write to quotafile (we know the transaction is already started and has
6567  * enough credits) */
6568 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6569 				const char *data, size_t len, loff_t off)
6570 {
6571 	struct inode *inode = sb_dqopt(sb)->files[type];
6572 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6573 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6574 	int retries = 0;
6575 	struct buffer_head *bh;
6576 	handle_t *handle = journal_current_handle();
6577 
6578 	if (EXT4_SB(sb)->s_journal && !handle) {
6579 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6580 			" cancelled because transaction is not started",
6581 			(unsigned long long)off, (unsigned long long)len);
6582 		return -EIO;
6583 	}
6584 	/*
6585 	 * Since we account only one data block in transaction credits,
6586 	 * then it is impossible to cross a block boundary.
6587 	 */
6588 	if (sb->s_blocksize - offset < len) {
6589 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6590 			" cancelled because not block aligned",
6591 			(unsigned long long)off, (unsigned long long)len);
6592 		return -EIO;
6593 	}
6594 
6595 	do {
6596 		bh = ext4_bread(handle, inode, blk,
6597 				EXT4_GET_BLOCKS_CREATE |
6598 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6599 	} while (PTR_ERR(bh) == -ENOSPC &&
6600 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6601 	if (IS_ERR(bh))
6602 		return PTR_ERR(bh);
6603 	if (!bh)
6604 		goto out;
6605 	BUFFER_TRACE(bh, "get write access");
6606 	err = ext4_journal_get_write_access(handle, bh);
6607 	if (err) {
6608 		brelse(bh);
6609 		return err;
6610 	}
6611 	lock_buffer(bh);
6612 	memcpy(bh->b_data+offset, data, len);
6613 	flush_dcache_page(bh->b_page);
6614 	unlock_buffer(bh);
6615 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6616 	brelse(bh);
6617 out:
6618 	if (inode->i_size < off + len) {
6619 		i_size_write(inode, off + len);
6620 		EXT4_I(inode)->i_disksize = inode->i_size;
6621 		err2 = ext4_mark_inode_dirty(handle, inode);
6622 		if (unlikely(err2 && !err))
6623 			err = err2;
6624 	}
6625 	return err ? err : len;
6626 }
6627 #endif
6628 
6629 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6630 		       const char *dev_name, void *data)
6631 {
6632 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6633 }
6634 
6635 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6636 static inline void register_as_ext2(void)
6637 {
6638 	int err = register_filesystem(&ext2_fs_type);
6639 	if (err)
6640 		printk(KERN_WARNING
6641 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6642 }
6643 
6644 static inline void unregister_as_ext2(void)
6645 {
6646 	unregister_filesystem(&ext2_fs_type);
6647 }
6648 
6649 static inline int ext2_feature_set_ok(struct super_block *sb)
6650 {
6651 	if (ext4_has_unknown_ext2_incompat_features(sb))
6652 		return 0;
6653 	if (sb_rdonly(sb))
6654 		return 1;
6655 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6656 		return 0;
6657 	return 1;
6658 }
6659 #else
6660 static inline void register_as_ext2(void) { }
6661 static inline void unregister_as_ext2(void) { }
6662 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6663 #endif
6664 
6665 static inline void register_as_ext3(void)
6666 {
6667 	int err = register_filesystem(&ext3_fs_type);
6668 	if (err)
6669 		printk(KERN_WARNING
6670 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6671 }
6672 
6673 static inline void unregister_as_ext3(void)
6674 {
6675 	unregister_filesystem(&ext3_fs_type);
6676 }
6677 
6678 static inline int ext3_feature_set_ok(struct super_block *sb)
6679 {
6680 	if (ext4_has_unknown_ext3_incompat_features(sb))
6681 		return 0;
6682 	if (!ext4_has_feature_journal(sb))
6683 		return 0;
6684 	if (sb_rdonly(sb))
6685 		return 1;
6686 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6687 		return 0;
6688 	return 1;
6689 }
6690 
6691 static struct file_system_type ext4_fs_type = {
6692 	.owner		= THIS_MODULE,
6693 	.name		= "ext4",
6694 	.mount		= ext4_mount,
6695 	.kill_sb	= kill_block_super,
6696 	.fs_flags	= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
6697 };
6698 MODULE_ALIAS_FS("ext4");
6699 
6700 /* Shared across all ext4 file systems */
6701 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6702 
6703 static int __init ext4_init_fs(void)
6704 {
6705 	int i, err;
6706 
6707 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6708 	ext4_li_info = NULL;
6709 
6710 	/* Build-time check for flags consistency */
6711 	ext4_check_flag_values();
6712 
6713 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6714 		init_waitqueue_head(&ext4__ioend_wq[i]);
6715 
6716 	err = ext4_init_es();
6717 	if (err)
6718 		return err;
6719 
6720 	err = ext4_init_pending();
6721 	if (err)
6722 		goto out7;
6723 
6724 	err = ext4_init_post_read_processing();
6725 	if (err)
6726 		goto out6;
6727 
6728 	err = ext4_init_pageio();
6729 	if (err)
6730 		goto out5;
6731 
6732 	err = ext4_init_system_zone();
6733 	if (err)
6734 		goto out4;
6735 
6736 	err = ext4_init_sysfs();
6737 	if (err)
6738 		goto out3;
6739 
6740 	err = ext4_init_mballoc();
6741 	if (err)
6742 		goto out2;
6743 	err = init_inodecache();
6744 	if (err)
6745 		goto out1;
6746 
6747 	err = ext4_fc_init_dentry_cache();
6748 	if (err)
6749 		goto out05;
6750 
6751 	register_as_ext3();
6752 	register_as_ext2();
6753 	err = register_filesystem(&ext4_fs_type);
6754 	if (err)
6755 		goto out;
6756 
6757 	return 0;
6758 out:
6759 	unregister_as_ext2();
6760 	unregister_as_ext3();
6761 out05:
6762 	destroy_inodecache();
6763 out1:
6764 	ext4_exit_mballoc();
6765 out2:
6766 	ext4_exit_sysfs();
6767 out3:
6768 	ext4_exit_system_zone();
6769 out4:
6770 	ext4_exit_pageio();
6771 out5:
6772 	ext4_exit_post_read_processing();
6773 out6:
6774 	ext4_exit_pending();
6775 out7:
6776 	ext4_exit_es();
6777 
6778 	return err;
6779 }
6780 
6781 static void __exit ext4_exit_fs(void)
6782 {
6783 	ext4_destroy_lazyinit_thread();
6784 	unregister_as_ext2();
6785 	unregister_as_ext3();
6786 	unregister_filesystem(&ext4_fs_type);
6787 	destroy_inodecache();
6788 	ext4_exit_mballoc();
6789 	ext4_exit_sysfs();
6790 	ext4_exit_system_zone();
6791 	ext4_exit_pageio();
6792 	ext4_exit_post_read_processing();
6793 	ext4_exit_es();
6794 	ext4_exit_pending();
6795 }
6796 
6797 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6798 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6799 MODULE_LICENSE("GPL");
6800 MODULE_SOFTDEP("pre: crc32c");
6801 module_init(ext4_init_fs)
6802 module_exit(ext4_exit_fs)
6803