xref: /openbmc/linux/fs/ext4/super.c (revision 141e5239)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static int ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static const struct fs_parameter_spec ext4_param_specs[];
97 
98 /*
99  * Lock ordering
100  *
101  * page fault path:
102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
103  *   -> page lock -> i_data_sem (rw)
104  *
105  * buffered write path:
106  * sb_start_write -> i_mutex -> mmap_lock
107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
108  *   i_data_sem (rw)
109  *
110  * truncate:
111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
112  *   page lock
113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
114  *   i_data_sem (rw)
115  *
116  * direct IO:
117  * sb_start_write -> i_mutex -> mmap_lock
118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
119  *
120  * writepages:
121  * transaction start -> page lock(s) -> i_data_sem (rw)
122  */
123 
124 static const struct fs_context_operations ext4_context_ops = {
125 	.parse_param	= ext4_parse_param,
126 	.get_tree	= ext4_get_tree,
127 	.reconfigure	= ext4_reconfigure,
128 	.free		= ext4_fc_free,
129 };
130 
131 
132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
133 static struct file_system_type ext2_fs_type = {
134 	.owner			= THIS_MODULE,
135 	.name			= "ext2",
136 	.init_fs_context	= ext4_init_fs_context,
137 	.parameters		= ext4_param_specs,
138 	.kill_sb		= kill_block_super,
139 	.fs_flags		= FS_REQUIRES_DEV,
140 };
141 MODULE_ALIAS_FS("ext2");
142 MODULE_ALIAS("ext2");
143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
144 #else
145 #define IS_EXT2_SB(sb) (0)
146 #endif
147 
148 
149 static struct file_system_type ext3_fs_type = {
150 	.owner			= THIS_MODULE,
151 	.name			= "ext3",
152 	.init_fs_context	= ext4_init_fs_context,
153 	.parameters		= ext4_param_specs,
154 	.kill_sb		= kill_block_super,
155 	.fs_flags		= FS_REQUIRES_DEV,
156 };
157 MODULE_ALIAS_FS("ext3");
158 MODULE_ALIAS("ext3");
159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
160 
161 
162 static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags,
163 				  bh_end_io_t *end_io)
164 {
165 	/*
166 	 * buffer's verified bit is no longer valid after reading from
167 	 * disk again due to write out error, clear it to make sure we
168 	 * recheck the buffer contents.
169 	 */
170 	clear_buffer_verified(bh);
171 
172 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
173 	get_bh(bh);
174 	submit_bh(REQ_OP_READ, op_flags, bh);
175 }
176 
177 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
178 			 bh_end_io_t *end_io)
179 {
180 	BUG_ON(!buffer_locked(bh));
181 
182 	if (ext4_buffer_uptodate(bh)) {
183 		unlock_buffer(bh);
184 		return;
185 	}
186 	__ext4_read_bh(bh, op_flags, end_io);
187 }
188 
189 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
190 {
191 	BUG_ON(!buffer_locked(bh));
192 
193 	if (ext4_buffer_uptodate(bh)) {
194 		unlock_buffer(bh);
195 		return 0;
196 	}
197 
198 	__ext4_read_bh(bh, op_flags, end_io);
199 
200 	wait_on_buffer(bh);
201 	if (buffer_uptodate(bh))
202 		return 0;
203 	return -EIO;
204 }
205 
206 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
207 {
208 	if (trylock_buffer(bh)) {
209 		if (wait)
210 			return ext4_read_bh(bh, op_flags, NULL);
211 		ext4_read_bh_nowait(bh, op_flags, NULL);
212 		return 0;
213 	}
214 	if (wait) {
215 		wait_on_buffer(bh);
216 		if (buffer_uptodate(bh))
217 			return 0;
218 		return -EIO;
219 	}
220 	return 0;
221 }
222 
223 /*
224  * This works like __bread_gfp() except it uses ERR_PTR for error
225  * returns.  Currently with sb_bread it's impossible to distinguish
226  * between ENOMEM and EIO situations (since both result in a NULL
227  * return.
228  */
229 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
230 					       sector_t block, int op_flags,
231 					       gfp_t gfp)
232 {
233 	struct buffer_head *bh;
234 	int ret;
235 
236 	bh = sb_getblk_gfp(sb, block, gfp);
237 	if (bh == NULL)
238 		return ERR_PTR(-ENOMEM);
239 	if (ext4_buffer_uptodate(bh))
240 		return bh;
241 
242 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
243 	if (ret) {
244 		put_bh(bh);
245 		return ERR_PTR(ret);
246 	}
247 	return bh;
248 }
249 
250 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
251 				   int op_flags)
252 {
253 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
254 }
255 
256 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
257 					    sector_t block)
258 {
259 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
260 }
261 
262 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
263 {
264 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
265 
266 	if (likely(bh)) {
267 		ext4_read_bh_lock(bh, REQ_RAHEAD, false);
268 		brelse(bh);
269 	}
270 }
271 
272 static int ext4_verify_csum_type(struct super_block *sb,
273 				 struct ext4_super_block *es)
274 {
275 	if (!ext4_has_feature_metadata_csum(sb))
276 		return 1;
277 
278 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
279 }
280 
281 __le32 ext4_superblock_csum(struct super_block *sb,
282 			    struct ext4_super_block *es)
283 {
284 	struct ext4_sb_info *sbi = EXT4_SB(sb);
285 	int offset = offsetof(struct ext4_super_block, s_checksum);
286 	__u32 csum;
287 
288 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
289 
290 	return cpu_to_le32(csum);
291 }
292 
293 static int ext4_superblock_csum_verify(struct super_block *sb,
294 				       struct ext4_super_block *es)
295 {
296 	if (!ext4_has_metadata_csum(sb))
297 		return 1;
298 
299 	return es->s_checksum == ext4_superblock_csum(sb, es);
300 }
301 
302 void ext4_superblock_csum_set(struct super_block *sb)
303 {
304 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
305 
306 	if (!ext4_has_metadata_csum(sb))
307 		return;
308 
309 	es->s_checksum = ext4_superblock_csum(sb, es);
310 }
311 
312 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
313 			       struct ext4_group_desc *bg)
314 {
315 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
316 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
317 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
318 }
319 
320 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
321 			       struct ext4_group_desc *bg)
322 {
323 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
324 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
325 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
326 }
327 
328 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
329 			      struct ext4_group_desc *bg)
330 {
331 	return le32_to_cpu(bg->bg_inode_table_lo) |
332 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
333 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
334 }
335 
336 __u32 ext4_free_group_clusters(struct super_block *sb,
337 			       struct ext4_group_desc *bg)
338 {
339 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
340 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
341 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
342 }
343 
344 __u32 ext4_free_inodes_count(struct super_block *sb,
345 			      struct ext4_group_desc *bg)
346 {
347 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
348 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
349 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
350 }
351 
352 __u32 ext4_used_dirs_count(struct super_block *sb,
353 			      struct ext4_group_desc *bg)
354 {
355 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
356 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
357 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
358 }
359 
360 __u32 ext4_itable_unused_count(struct super_block *sb,
361 			      struct ext4_group_desc *bg)
362 {
363 	return le16_to_cpu(bg->bg_itable_unused_lo) |
364 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
365 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
366 }
367 
368 void ext4_block_bitmap_set(struct super_block *sb,
369 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
370 {
371 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
372 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
373 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
374 }
375 
376 void ext4_inode_bitmap_set(struct super_block *sb,
377 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
378 {
379 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
380 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
381 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
382 }
383 
384 void ext4_inode_table_set(struct super_block *sb,
385 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
386 {
387 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
388 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
389 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
390 }
391 
392 void ext4_free_group_clusters_set(struct super_block *sb,
393 				  struct ext4_group_desc *bg, __u32 count)
394 {
395 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
396 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
397 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
398 }
399 
400 void ext4_free_inodes_set(struct super_block *sb,
401 			  struct ext4_group_desc *bg, __u32 count)
402 {
403 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
404 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
405 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
406 }
407 
408 void ext4_used_dirs_set(struct super_block *sb,
409 			  struct ext4_group_desc *bg, __u32 count)
410 {
411 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
412 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
413 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
414 }
415 
416 void ext4_itable_unused_set(struct super_block *sb,
417 			  struct ext4_group_desc *bg, __u32 count)
418 {
419 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
420 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
421 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
422 }
423 
424 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
425 {
426 	now = clamp_val(now, 0, (1ull << 40) - 1);
427 
428 	*lo = cpu_to_le32(lower_32_bits(now));
429 	*hi = upper_32_bits(now);
430 }
431 
432 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
433 {
434 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
435 }
436 #define ext4_update_tstamp(es, tstamp) \
437 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
438 			     ktime_get_real_seconds())
439 #define ext4_get_tstamp(es, tstamp) \
440 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
441 
442 /*
443  * The del_gendisk() function uninitializes the disk-specific data
444  * structures, including the bdi structure, without telling anyone
445  * else.  Once this happens, any attempt to call mark_buffer_dirty()
446  * (for example, by ext4_commit_super), will cause a kernel OOPS.
447  * This is a kludge to prevent these oops until we can put in a proper
448  * hook in del_gendisk() to inform the VFS and file system layers.
449  */
450 static int block_device_ejected(struct super_block *sb)
451 {
452 	struct inode *bd_inode = sb->s_bdev->bd_inode;
453 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
454 
455 	return bdi->dev == NULL;
456 }
457 
458 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
459 {
460 	struct super_block		*sb = journal->j_private;
461 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
462 	int				error = is_journal_aborted(journal);
463 	struct ext4_journal_cb_entry	*jce;
464 
465 	BUG_ON(txn->t_state == T_FINISHED);
466 
467 	ext4_process_freed_data(sb, txn->t_tid);
468 
469 	spin_lock(&sbi->s_md_lock);
470 	while (!list_empty(&txn->t_private_list)) {
471 		jce = list_entry(txn->t_private_list.next,
472 				 struct ext4_journal_cb_entry, jce_list);
473 		list_del_init(&jce->jce_list);
474 		spin_unlock(&sbi->s_md_lock);
475 		jce->jce_func(sb, jce, error);
476 		spin_lock(&sbi->s_md_lock);
477 	}
478 	spin_unlock(&sbi->s_md_lock);
479 }
480 
481 /*
482  * This writepage callback for write_cache_pages()
483  * takes care of a few cases after page cleaning.
484  *
485  * write_cache_pages() already checks for dirty pages
486  * and calls clear_page_dirty_for_io(), which we want,
487  * to write protect the pages.
488  *
489  * However, we may have to redirty a page (see below.)
490  */
491 static int ext4_journalled_writepage_callback(struct page *page,
492 					      struct writeback_control *wbc,
493 					      void *data)
494 {
495 	transaction_t *transaction = (transaction_t *) data;
496 	struct buffer_head *bh, *head;
497 	struct journal_head *jh;
498 
499 	bh = head = page_buffers(page);
500 	do {
501 		/*
502 		 * We have to redirty a page in these cases:
503 		 * 1) If buffer is dirty, it means the page was dirty because it
504 		 * contains a buffer that needs checkpointing. So the dirty bit
505 		 * needs to be preserved so that checkpointing writes the buffer
506 		 * properly.
507 		 * 2) If buffer is not part of the committing transaction
508 		 * (we may have just accidentally come across this buffer because
509 		 * inode range tracking is not exact) or if the currently running
510 		 * transaction already contains this buffer as well, dirty bit
511 		 * needs to be preserved so that the buffer gets writeprotected
512 		 * properly on running transaction's commit.
513 		 */
514 		jh = bh2jh(bh);
515 		if (buffer_dirty(bh) ||
516 		    (jh && (jh->b_transaction != transaction ||
517 			    jh->b_next_transaction))) {
518 			redirty_page_for_writepage(wbc, page);
519 			goto out;
520 		}
521 	} while ((bh = bh->b_this_page) != head);
522 
523 out:
524 	return AOP_WRITEPAGE_ACTIVATE;
525 }
526 
527 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
528 {
529 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
530 	struct writeback_control wbc = {
531 		.sync_mode =  WB_SYNC_ALL,
532 		.nr_to_write = LONG_MAX,
533 		.range_start = jinode->i_dirty_start,
534 		.range_end = jinode->i_dirty_end,
535         };
536 
537 	return write_cache_pages(mapping, &wbc,
538 				 ext4_journalled_writepage_callback,
539 				 jinode->i_transaction);
540 }
541 
542 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
543 {
544 	int ret;
545 
546 	if (ext4_should_journal_data(jinode->i_vfs_inode))
547 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
548 	else
549 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
550 
551 	return ret;
552 }
553 
554 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
555 {
556 	int ret = 0;
557 
558 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
559 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
560 
561 	return ret;
562 }
563 
564 static bool system_going_down(void)
565 {
566 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
567 		|| system_state == SYSTEM_RESTART;
568 }
569 
570 struct ext4_err_translation {
571 	int code;
572 	int errno;
573 };
574 
575 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
576 
577 static struct ext4_err_translation err_translation[] = {
578 	EXT4_ERR_TRANSLATE(EIO),
579 	EXT4_ERR_TRANSLATE(ENOMEM),
580 	EXT4_ERR_TRANSLATE(EFSBADCRC),
581 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
582 	EXT4_ERR_TRANSLATE(ENOSPC),
583 	EXT4_ERR_TRANSLATE(ENOKEY),
584 	EXT4_ERR_TRANSLATE(EROFS),
585 	EXT4_ERR_TRANSLATE(EFBIG),
586 	EXT4_ERR_TRANSLATE(EEXIST),
587 	EXT4_ERR_TRANSLATE(ERANGE),
588 	EXT4_ERR_TRANSLATE(EOVERFLOW),
589 	EXT4_ERR_TRANSLATE(EBUSY),
590 	EXT4_ERR_TRANSLATE(ENOTDIR),
591 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
592 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
593 	EXT4_ERR_TRANSLATE(EFAULT),
594 };
595 
596 static int ext4_errno_to_code(int errno)
597 {
598 	int i;
599 
600 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
601 		if (err_translation[i].errno == errno)
602 			return err_translation[i].code;
603 	return EXT4_ERR_UNKNOWN;
604 }
605 
606 static void save_error_info(struct super_block *sb, int error,
607 			    __u32 ino, __u64 block,
608 			    const char *func, unsigned int line)
609 {
610 	struct ext4_sb_info *sbi = EXT4_SB(sb);
611 
612 	/* We default to EFSCORRUPTED error... */
613 	if (error == 0)
614 		error = EFSCORRUPTED;
615 
616 	spin_lock(&sbi->s_error_lock);
617 	sbi->s_add_error_count++;
618 	sbi->s_last_error_code = error;
619 	sbi->s_last_error_line = line;
620 	sbi->s_last_error_ino = ino;
621 	sbi->s_last_error_block = block;
622 	sbi->s_last_error_func = func;
623 	sbi->s_last_error_time = ktime_get_real_seconds();
624 	if (!sbi->s_first_error_time) {
625 		sbi->s_first_error_code = error;
626 		sbi->s_first_error_line = line;
627 		sbi->s_first_error_ino = ino;
628 		sbi->s_first_error_block = block;
629 		sbi->s_first_error_func = func;
630 		sbi->s_first_error_time = sbi->s_last_error_time;
631 	}
632 	spin_unlock(&sbi->s_error_lock);
633 }
634 
635 /* Deal with the reporting of failure conditions on a filesystem such as
636  * inconsistencies detected or read IO failures.
637  *
638  * On ext2, we can store the error state of the filesystem in the
639  * superblock.  That is not possible on ext4, because we may have other
640  * write ordering constraints on the superblock which prevent us from
641  * writing it out straight away; and given that the journal is about to
642  * be aborted, we can't rely on the current, or future, transactions to
643  * write out the superblock safely.
644  *
645  * We'll just use the jbd2_journal_abort() error code to record an error in
646  * the journal instead.  On recovery, the journal will complain about
647  * that error until we've noted it down and cleared it.
648  *
649  * If force_ro is set, we unconditionally force the filesystem into an
650  * ABORT|READONLY state, unless the error response on the fs has been set to
651  * panic in which case we take the easy way out and panic immediately. This is
652  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
653  * at a critical moment in log management.
654  */
655 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
656 			      __u32 ino, __u64 block,
657 			      const char *func, unsigned int line)
658 {
659 	journal_t *journal = EXT4_SB(sb)->s_journal;
660 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
661 
662 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
663 	if (test_opt(sb, WARN_ON_ERROR))
664 		WARN_ON_ONCE(1);
665 
666 	if (!continue_fs && !sb_rdonly(sb)) {
667 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
668 		if (journal)
669 			jbd2_journal_abort(journal, -EIO);
670 	}
671 
672 	if (!bdev_read_only(sb->s_bdev)) {
673 		save_error_info(sb, error, ino, block, func, line);
674 		/*
675 		 * In case the fs should keep running, we need to writeout
676 		 * superblock through the journal. Due to lock ordering
677 		 * constraints, it may not be safe to do it right here so we
678 		 * defer superblock flushing to a workqueue.
679 		 */
680 		if (continue_fs && journal)
681 			schedule_work(&EXT4_SB(sb)->s_error_work);
682 		else
683 			ext4_commit_super(sb);
684 	}
685 
686 	/*
687 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
688 	 * could panic during 'reboot -f' as the underlying device got already
689 	 * disabled.
690 	 */
691 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
692 		panic("EXT4-fs (device %s): panic forced after error\n",
693 			sb->s_id);
694 	}
695 
696 	if (sb_rdonly(sb) || continue_fs)
697 		return;
698 
699 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
700 	/*
701 	 * Make sure updated value of ->s_mount_flags will be visible before
702 	 * ->s_flags update
703 	 */
704 	smp_wmb();
705 	sb->s_flags |= SB_RDONLY;
706 }
707 
708 static void flush_stashed_error_work(struct work_struct *work)
709 {
710 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
711 						s_error_work);
712 	journal_t *journal = sbi->s_journal;
713 	handle_t *handle;
714 
715 	/*
716 	 * If the journal is still running, we have to write out superblock
717 	 * through the journal to avoid collisions of other journalled sb
718 	 * updates.
719 	 *
720 	 * We use directly jbd2 functions here to avoid recursing back into
721 	 * ext4 error handling code during handling of previous errors.
722 	 */
723 	if (!sb_rdonly(sbi->s_sb) && journal) {
724 		struct buffer_head *sbh = sbi->s_sbh;
725 		handle = jbd2_journal_start(journal, 1);
726 		if (IS_ERR(handle))
727 			goto write_directly;
728 		if (jbd2_journal_get_write_access(handle, sbh)) {
729 			jbd2_journal_stop(handle);
730 			goto write_directly;
731 		}
732 		ext4_update_super(sbi->s_sb);
733 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
734 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
735 				 "superblock detected");
736 			clear_buffer_write_io_error(sbh);
737 			set_buffer_uptodate(sbh);
738 		}
739 
740 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
741 			jbd2_journal_stop(handle);
742 			goto write_directly;
743 		}
744 		jbd2_journal_stop(handle);
745 		ext4_notify_error_sysfs(sbi);
746 		return;
747 	}
748 write_directly:
749 	/*
750 	 * Write through journal failed. Write sb directly to get error info
751 	 * out and hope for the best.
752 	 */
753 	ext4_commit_super(sbi->s_sb);
754 	ext4_notify_error_sysfs(sbi);
755 }
756 
757 #define ext4_error_ratelimit(sb)					\
758 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
759 			     "EXT4-fs error")
760 
761 void __ext4_error(struct super_block *sb, const char *function,
762 		  unsigned int line, bool force_ro, int error, __u64 block,
763 		  const char *fmt, ...)
764 {
765 	struct va_format vaf;
766 	va_list args;
767 
768 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
769 		return;
770 
771 	trace_ext4_error(sb, function, line);
772 	if (ext4_error_ratelimit(sb)) {
773 		va_start(args, fmt);
774 		vaf.fmt = fmt;
775 		vaf.va = &args;
776 		printk(KERN_CRIT
777 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
778 		       sb->s_id, function, line, current->comm, &vaf);
779 		va_end(args);
780 	}
781 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
782 
783 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
784 }
785 
786 void __ext4_error_inode(struct inode *inode, const char *function,
787 			unsigned int line, ext4_fsblk_t block, int error,
788 			const char *fmt, ...)
789 {
790 	va_list args;
791 	struct va_format vaf;
792 
793 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
794 		return;
795 
796 	trace_ext4_error(inode->i_sb, function, line);
797 	if (ext4_error_ratelimit(inode->i_sb)) {
798 		va_start(args, fmt);
799 		vaf.fmt = fmt;
800 		vaf.va = &args;
801 		if (block)
802 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
803 			       "inode #%lu: block %llu: comm %s: %pV\n",
804 			       inode->i_sb->s_id, function, line, inode->i_ino,
805 			       block, current->comm, &vaf);
806 		else
807 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
808 			       "inode #%lu: comm %s: %pV\n",
809 			       inode->i_sb->s_id, function, line, inode->i_ino,
810 			       current->comm, &vaf);
811 		va_end(args);
812 	}
813 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
814 
815 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
816 			  function, line);
817 }
818 
819 void __ext4_error_file(struct file *file, const char *function,
820 		       unsigned int line, ext4_fsblk_t block,
821 		       const char *fmt, ...)
822 {
823 	va_list args;
824 	struct va_format vaf;
825 	struct inode *inode = file_inode(file);
826 	char pathname[80], *path;
827 
828 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
829 		return;
830 
831 	trace_ext4_error(inode->i_sb, function, line);
832 	if (ext4_error_ratelimit(inode->i_sb)) {
833 		path = file_path(file, pathname, sizeof(pathname));
834 		if (IS_ERR(path))
835 			path = "(unknown)";
836 		va_start(args, fmt);
837 		vaf.fmt = fmt;
838 		vaf.va = &args;
839 		if (block)
840 			printk(KERN_CRIT
841 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
842 			       "block %llu: comm %s: path %s: %pV\n",
843 			       inode->i_sb->s_id, function, line, inode->i_ino,
844 			       block, current->comm, path, &vaf);
845 		else
846 			printk(KERN_CRIT
847 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
848 			       "comm %s: path %s: %pV\n",
849 			       inode->i_sb->s_id, function, line, inode->i_ino,
850 			       current->comm, path, &vaf);
851 		va_end(args);
852 	}
853 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
854 
855 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
856 			  function, line);
857 }
858 
859 const char *ext4_decode_error(struct super_block *sb, int errno,
860 			      char nbuf[16])
861 {
862 	char *errstr = NULL;
863 
864 	switch (errno) {
865 	case -EFSCORRUPTED:
866 		errstr = "Corrupt filesystem";
867 		break;
868 	case -EFSBADCRC:
869 		errstr = "Filesystem failed CRC";
870 		break;
871 	case -EIO:
872 		errstr = "IO failure";
873 		break;
874 	case -ENOMEM:
875 		errstr = "Out of memory";
876 		break;
877 	case -EROFS:
878 		if (!sb || (EXT4_SB(sb)->s_journal &&
879 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
880 			errstr = "Journal has aborted";
881 		else
882 			errstr = "Readonly filesystem";
883 		break;
884 	default:
885 		/* If the caller passed in an extra buffer for unknown
886 		 * errors, textualise them now.  Else we just return
887 		 * NULL. */
888 		if (nbuf) {
889 			/* Check for truncated error codes... */
890 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
891 				errstr = nbuf;
892 		}
893 		break;
894 	}
895 
896 	return errstr;
897 }
898 
899 /* __ext4_std_error decodes expected errors from journaling functions
900  * automatically and invokes the appropriate error response.  */
901 
902 void __ext4_std_error(struct super_block *sb, const char *function,
903 		      unsigned int line, int errno)
904 {
905 	char nbuf[16];
906 	const char *errstr;
907 
908 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
909 		return;
910 
911 	/* Special case: if the error is EROFS, and we're not already
912 	 * inside a transaction, then there's really no point in logging
913 	 * an error. */
914 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
915 		return;
916 
917 	if (ext4_error_ratelimit(sb)) {
918 		errstr = ext4_decode_error(sb, errno, nbuf);
919 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
920 		       sb->s_id, function, line, errstr);
921 	}
922 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
923 
924 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
925 }
926 
927 void __ext4_msg(struct super_block *sb,
928 		const char *prefix, const char *fmt, ...)
929 {
930 	struct va_format vaf;
931 	va_list args;
932 
933 	if (sb) {
934 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
935 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
936 				  "EXT4-fs"))
937 			return;
938 	}
939 
940 	va_start(args, fmt);
941 	vaf.fmt = fmt;
942 	vaf.va = &args;
943 	if (sb)
944 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
945 	else
946 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
947 	va_end(args);
948 }
949 
950 static int ext4_warning_ratelimit(struct super_block *sb)
951 {
952 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
953 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
954 			    "EXT4-fs warning");
955 }
956 
957 void __ext4_warning(struct super_block *sb, const char *function,
958 		    unsigned int line, const char *fmt, ...)
959 {
960 	struct va_format vaf;
961 	va_list args;
962 
963 	if (!ext4_warning_ratelimit(sb))
964 		return;
965 
966 	va_start(args, fmt);
967 	vaf.fmt = fmt;
968 	vaf.va = &args;
969 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
970 	       sb->s_id, function, line, &vaf);
971 	va_end(args);
972 }
973 
974 void __ext4_warning_inode(const struct inode *inode, const char *function,
975 			  unsigned int line, const char *fmt, ...)
976 {
977 	struct va_format vaf;
978 	va_list args;
979 
980 	if (!ext4_warning_ratelimit(inode->i_sb))
981 		return;
982 
983 	va_start(args, fmt);
984 	vaf.fmt = fmt;
985 	vaf.va = &args;
986 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
987 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
988 	       function, line, inode->i_ino, current->comm, &vaf);
989 	va_end(args);
990 }
991 
992 void __ext4_grp_locked_error(const char *function, unsigned int line,
993 			     struct super_block *sb, ext4_group_t grp,
994 			     unsigned long ino, ext4_fsblk_t block,
995 			     const char *fmt, ...)
996 __releases(bitlock)
997 __acquires(bitlock)
998 {
999 	struct va_format vaf;
1000 	va_list args;
1001 
1002 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
1003 		return;
1004 
1005 	trace_ext4_error(sb, function, line);
1006 	if (ext4_error_ratelimit(sb)) {
1007 		va_start(args, fmt);
1008 		vaf.fmt = fmt;
1009 		vaf.va = &args;
1010 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1011 		       sb->s_id, function, line, grp);
1012 		if (ino)
1013 			printk(KERN_CONT "inode %lu: ", ino);
1014 		if (block)
1015 			printk(KERN_CONT "block %llu:",
1016 			       (unsigned long long) block);
1017 		printk(KERN_CONT "%pV\n", &vaf);
1018 		va_end(args);
1019 	}
1020 
1021 	if (test_opt(sb, ERRORS_CONT)) {
1022 		if (test_opt(sb, WARN_ON_ERROR))
1023 			WARN_ON_ONCE(1);
1024 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1025 		if (!bdev_read_only(sb->s_bdev)) {
1026 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1027 					line);
1028 			schedule_work(&EXT4_SB(sb)->s_error_work);
1029 		}
1030 		return;
1031 	}
1032 	ext4_unlock_group(sb, grp);
1033 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1034 	/*
1035 	 * We only get here in the ERRORS_RO case; relocking the group
1036 	 * may be dangerous, but nothing bad will happen since the
1037 	 * filesystem will have already been marked read/only and the
1038 	 * journal has been aborted.  We return 1 as a hint to callers
1039 	 * who might what to use the return value from
1040 	 * ext4_grp_locked_error() to distinguish between the
1041 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1042 	 * aggressively from the ext4 function in question, with a
1043 	 * more appropriate error code.
1044 	 */
1045 	ext4_lock_group(sb, grp);
1046 	return;
1047 }
1048 
1049 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1050 				     ext4_group_t group,
1051 				     unsigned int flags)
1052 {
1053 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1054 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1055 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1056 	int ret;
1057 
1058 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1059 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1060 					    &grp->bb_state);
1061 		if (!ret)
1062 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1063 					   grp->bb_free);
1064 	}
1065 
1066 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1067 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1068 					    &grp->bb_state);
1069 		if (!ret && gdp) {
1070 			int count;
1071 
1072 			count = ext4_free_inodes_count(sb, gdp);
1073 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1074 					   count);
1075 		}
1076 	}
1077 }
1078 
1079 void ext4_update_dynamic_rev(struct super_block *sb)
1080 {
1081 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1082 
1083 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1084 		return;
1085 
1086 	ext4_warning(sb,
1087 		     "updating to rev %d because of new feature flag, "
1088 		     "running e2fsck is recommended",
1089 		     EXT4_DYNAMIC_REV);
1090 
1091 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1092 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1093 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1094 	/* leave es->s_feature_*compat flags alone */
1095 	/* es->s_uuid will be set by e2fsck if empty */
1096 
1097 	/*
1098 	 * The rest of the superblock fields should be zero, and if not it
1099 	 * means they are likely already in use, so leave them alone.  We
1100 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1101 	 */
1102 }
1103 
1104 /*
1105  * Open the external journal device
1106  */
1107 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1108 {
1109 	struct block_device *bdev;
1110 
1111 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1112 	if (IS_ERR(bdev))
1113 		goto fail;
1114 	return bdev;
1115 
1116 fail:
1117 	ext4_msg(sb, KERN_ERR,
1118 		 "failed to open journal device unknown-block(%u,%u) %ld",
1119 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1120 	return NULL;
1121 }
1122 
1123 /*
1124  * Release the journal device
1125  */
1126 static void ext4_blkdev_put(struct block_device *bdev)
1127 {
1128 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1129 }
1130 
1131 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1132 {
1133 	struct block_device *bdev;
1134 	bdev = sbi->s_journal_bdev;
1135 	if (bdev) {
1136 		ext4_blkdev_put(bdev);
1137 		sbi->s_journal_bdev = NULL;
1138 	}
1139 }
1140 
1141 static inline struct inode *orphan_list_entry(struct list_head *l)
1142 {
1143 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1144 }
1145 
1146 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1147 {
1148 	struct list_head *l;
1149 
1150 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1151 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1152 
1153 	printk(KERN_ERR "sb_info orphan list:\n");
1154 	list_for_each(l, &sbi->s_orphan) {
1155 		struct inode *inode = orphan_list_entry(l);
1156 		printk(KERN_ERR "  "
1157 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1158 		       inode->i_sb->s_id, inode->i_ino, inode,
1159 		       inode->i_mode, inode->i_nlink,
1160 		       NEXT_ORPHAN(inode));
1161 	}
1162 }
1163 
1164 #ifdef CONFIG_QUOTA
1165 static int ext4_quota_off(struct super_block *sb, int type);
1166 
1167 static inline void ext4_quota_off_umount(struct super_block *sb)
1168 {
1169 	int type;
1170 
1171 	/* Use our quota_off function to clear inode flags etc. */
1172 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1173 		ext4_quota_off(sb, type);
1174 }
1175 
1176 /*
1177  * This is a helper function which is used in the mount/remount
1178  * codepaths (which holds s_umount) to fetch the quota file name.
1179  */
1180 static inline char *get_qf_name(struct super_block *sb,
1181 				struct ext4_sb_info *sbi,
1182 				int type)
1183 {
1184 	return rcu_dereference_protected(sbi->s_qf_names[type],
1185 					 lockdep_is_held(&sb->s_umount));
1186 }
1187 #else
1188 static inline void ext4_quota_off_umount(struct super_block *sb)
1189 {
1190 }
1191 #endif
1192 
1193 static void ext4_put_super(struct super_block *sb)
1194 {
1195 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1196 	struct ext4_super_block *es = sbi->s_es;
1197 	struct buffer_head **group_desc;
1198 	struct flex_groups **flex_groups;
1199 	int aborted = 0;
1200 	int i, err;
1201 
1202 	/*
1203 	 * Unregister sysfs before destroying jbd2 journal.
1204 	 * Since we could still access attr_journal_task attribute via sysfs
1205 	 * path which could have sbi->s_journal->j_task as NULL
1206 	 * Unregister sysfs before flush sbi->s_error_work.
1207 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1208 	 * read metadata verify failed then will queue error work.
1209 	 * flush_stashed_error_work will call start_this_handle may trigger
1210 	 * BUG_ON.
1211 	 */
1212 	ext4_unregister_sysfs(sb);
1213 
1214 	ext4_unregister_li_request(sb);
1215 	ext4_quota_off_umount(sb);
1216 
1217 	flush_work(&sbi->s_error_work);
1218 	destroy_workqueue(sbi->rsv_conversion_wq);
1219 	ext4_release_orphan_info(sb);
1220 
1221 	if (sbi->s_journal) {
1222 		aborted = is_journal_aborted(sbi->s_journal);
1223 		err = jbd2_journal_destroy(sbi->s_journal);
1224 		sbi->s_journal = NULL;
1225 		if ((err < 0) && !aborted) {
1226 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1227 		}
1228 	}
1229 
1230 	ext4_es_unregister_shrinker(sbi);
1231 	del_timer_sync(&sbi->s_err_report);
1232 	ext4_release_system_zone(sb);
1233 	ext4_mb_release(sb);
1234 	ext4_ext_release(sb);
1235 
1236 	if (!sb_rdonly(sb) && !aborted) {
1237 		ext4_clear_feature_journal_needs_recovery(sb);
1238 		ext4_clear_feature_orphan_present(sb);
1239 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1240 	}
1241 	if (!sb_rdonly(sb))
1242 		ext4_commit_super(sb);
1243 
1244 	rcu_read_lock();
1245 	group_desc = rcu_dereference(sbi->s_group_desc);
1246 	for (i = 0; i < sbi->s_gdb_count; i++)
1247 		brelse(group_desc[i]);
1248 	kvfree(group_desc);
1249 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1250 	if (flex_groups) {
1251 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1252 			kvfree(flex_groups[i]);
1253 		kvfree(flex_groups);
1254 	}
1255 	rcu_read_unlock();
1256 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1257 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1258 	percpu_counter_destroy(&sbi->s_dirs_counter);
1259 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1260 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1261 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1262 #ifdef CONFIG_QUOTA
1263 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1264 		kfree(get_qf_name(sb, sbi, i));
1265 #endif
1266 
1267 	/* Debugging code just in case the in-memory inode orphan list
1268 	 * isn't empty.  The on-disk one can be non-empty if we've
1269 	 * detected an error and taken the fs readonly, but the
1270 	 * in-memory list had better be clean by this point. */
1271 	if (!list_empty(&sbi->s_orphan))
1272 		dump_orphan_list(sb, sbi);
1273 	ASSERT(list_empty(&sbi->s_orphan));
1274 
1275 	sync_blockdev(sb->s_bdev);
1276 	invalidate_bdev(sb->s_bdev);
1277 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1278 		/*
1279 		 * Invalidate the journal device's buffers.  We don't want them
1280 		 * floating about in memory - the physical journal device may
1281 		 * hotswapped, and it breaks the `ro-after' testing code.
1282 		 */
1283 		sync_blockdev(sbi->s_journal_bdev);
1284 		invalidate_bdev(sbi->s_journal_bdev);
1285 		ext4_blkdev_remove(sbi);
1286 	}
1287 
1288 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1289 	sbi->s_ea_inode_cache = NULL;
1290 
1291 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1292 	sbi->s_ea_block_cache = NULL;
1293 
1294 	ext4_stop_mmpd(sbi);
1295 
1296 	brelse(sbi->s_sbh);
1297 	sb->s_fs_info = NULL;
1298 	/*
1299 	 * Now that we are completely done shutting down the
1300 	 * superblock, we need to actually destroy the kobject.
1301 	 */
1302 	kobject_put(&sbi->s_kobj);
1303 	wait_for_completion(&sbi->s_kobj_unregister);
1304 	if (sbi->s_chksum_driver)
1305 		crypto_free_shash(sbi->s_chksum_driver);
1306 	kfree(sbi->s_blockgroup_lock);
1307 	fs_put_dax(sbi->s_daxdev);
1308 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1309 #if IS_ENABLED(CONFIG_UNICODE)
1310 	utf8_unload(sb->s_encoding);
1311 #endif
1312 	kfree(sbi);
1313 }
1314 
1315 static struct kmem_cache *ext4_inode_cachep;
1316 
1317 /*
1318  * Called inside transaction, so use GFP_NOFS
1319  */
1320 static struct inode *ext4_alloc_inode(struct super_block *sb)
1321 {
1322 	struct ext4_inode_info *ei;
1323 
1324 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1325 	if (!ei)
1326 		return NULL;
1327 
1328 	inode_set_iversion(&ei->vfs_inode, 1);
1329 	spin_lock_init(&ei->i_raw_lock);
1330 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1331 	atomic_set(&ei->i_prealloc_active, 0);
1332 	spin_lock_init(&ei->i_prealloc_lock);
1333 	ext4_es_init_tree(&ei->i_es_tree);
1334 	rwlock_init(&ei->i_es_lock);
1335 	INIT_LIST_HEAD(&ei->i_es_list);
1336 	ei->i_es_all_nr = 0;
1337 	ei->i_es_shk_nr = 0;
1338 	ei->i_es_shrink_lblk = 0;
1339 	ei->i_reserved_data_blocks = 0;
1340 	spin_lock_init(&(ei->i_block_reservation_lock));
1341 	ext4_init_pending_tree(&ei->i_pending_tree);
1342 #ifdef CONFIG_QUOTA
1343 	ei->i_reserved_quota = 0;
1344 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1345 #endif
1346 	ei->jinode = NULL;
1347 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1348 	spin_lock_init(&ei->i_completed_io_lock);
1349 	ei->i_sync_tid = 0;
1350 	ei->i_datasync_tid = 0;
1351 	atomic_set(&ei->i_unwritten, 0);
1352 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1353 	ext4_fc_init_inode(&ei->vfs_inode);
1354 	mutex_init(&ei->i_fc_lock);
1355 	return &ei->vfs_inode;
1356 }
1357 
1358 static int ext4_drop_inode(struct inode *inode)
1359 {
1360 	int drop = generic_drop_inode(inode);
1361 
1362 	if (!drop)
1363 		drop = fscrypt_drop_inode(inode);
1364 
1365 	trace_ext4_drop_inode(inode, drop);
1366 	return drop;
1367 }
1368 
1369 static void ext4_free_in_core_inode(struct inode *inode)
1370 {
1371 	fscrypt_free_inode(inode);
1372 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1373 		pr_warn("%s: inode %ld still in fc list",
1374 			__func__, inode->i_ino);
1375 	}
1376 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1377 }
1378 
1379 static void ext4_destroy_inode(struct inode *inode)
1380 {
1381 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1382 		ext4_msg(inode->i_sb, KERN_ERR,
1383 			 "Inode %lu (%p): orphan list check failed!",
1384 			 inode->i_ino, EXT4_I(inode));
1385 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1386 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1387 				true);
1388 		dump_stack();
1389 	}
1390 
1391 	if (EXT4_I(inode)->i_reserved_data_blocks)
1392 		ext4_msg(inode->i_sb, KERN_ERR,
1393 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1394 			 inode->i_ino, EXT4_I(inode),
1395 			 EXT4_I(inode)->i_reserved_data_blocks);
1396 }
1397 
1398 static void init_once(void *foo)
1399 {
1400 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1401 
1402 	INIT_LIST_HEAD(&ei->i_orphan);
1403 	init_rwsem(&ei->xattr_sem);
1404 	init_rwsem(&ei->i_data_sem);
1405 	inode_init_once(&ei->vfs_inode);
1406 	ext4_fc_init_inode(&ei->vfs_inode);
1407 }
1408 
1409 static int __init init_inodecache(void)
1410 {
1411 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1412 				sizeof(struct ext4_inode_info), 0,
1413 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1414 					SLAB_ACCOUNT),
1415 				offsetof(struct ext4_inode_info, i_data),
1416 				sizeof_field(struct ext4_inode_info, i_data),
1417 				init_once);
1418 	if (ext4_inode_cachep == NULL)
1419 		return -ENOMEM;
1420 	return 0;
1421 }
1422 
1423 static void destroy_inodecache(void)
1424 {
1425 	/*
1426 	 * Make sure all delayed rcu free inodes are flushed before we
1427 	 * destroy cache.
1428 	 */
1429 	rcu_barrier();
1430 	kmem_cache_destroy(ext4_inode_cachep);
1431 }
1432 
1433 void ext4_clear_inode(struct inode *inode)
1434 {
1435 	ext4_fc_del(inode);
1436 	invalidate_inode_buffers(inode);
1437 	clear_inode(inode);
1438 	ext4_discard_preallocations(inode, 0);
1439 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1440 	dquot_drop(inode);
1441 	if (EXT4_I(inode)->jinode) {
1442 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1443 					       EXT4_I(inode)->jinode);
1444 		jbd2_free_inode(EXT4_I(inode)->jinode);
1445 		EXT4_I(inode)->jinode = NULL;
1446 	}
1447 	fscrypt_put_encryption_info(inode);
1448 	fsverity_cleanup_inode(inode);
1449 }
1450 
1451 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1452 					u64 ino, u32 generation)
1453 {
1454 	struct inode *inode;
1455 
1456 	/*
1457 	 * Currently we don't know the generation for parent directory, so
1458 	 * a generation of 0 means "accept any"
1459 	 */
1460 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1461 	if (IS_ERR(inode))
1462 		return ERR_CAST(inode);
1463 	if (generation && inode->i_generation != generation) {
1464 		iput(inode);
1465 		return ERR_PTR(-ESTALE);
1466 	}
1467 
1468 	return inode;
1469 }
1470 
1471 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1472 					int fh_len, int fh_type)
1473 {
1474 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1475 				    ext4_nfs_get_inode);
1476 }
1477 
1478 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1479 					int fh_len, int fh_type)
1480 {
1481 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1482 				    ext4_nfs_get_inode);
1483 }
1484 
1485 static int ext4_nfs_commit_metadata(struct inode *inode)
1486 {
1487 	struct writeback_control wbc = {
1488 		.sync_mode = WB_SYNC_ALL
1489 	};
1490 
1491 	trace_ext4_nfs_commit_metadata(inode);
1492 	return ext4_write_inode(inode, &wbc);
1493 }
1494 
1495 #ifdef CONFIG_FS_ENCRYPTION
1496 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1497 {
1498 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1499 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1500 }
1501 
1502 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1503 							void *fs_data)
1504 {
1505 	handle_t *handle = fs_data;
1506 	int res, res2, credits, retries = 0;
1507 
1508 	/*
1509 	 * Encrypting the root directory is not allowed because e2fsck expects
1510 	 * lost+found to exist and be unencrypted, and encrypting the root
1511 	 * directory would imply encrypting the lost+found directory as well as
1512 	 * the filename "lost+found" itself.
1513 	 */
1514 	if (inode->i_ino == EXT4_ROOT_INO)
1515 		return -EPERM;
1516 
1517 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1518 		return -EINVAL;
1519 
1520 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1521 		return -EOPNOTSUPP;
1522 
1523 	res = ext4_convert_inline_data(inode);
1524 	if (res)
1525 		return res;
1526 
1527 	/*
1528 	 * If a journal handle was specified, then the encryption context is
1529 	 * being set on a new inode via inheritance and is part of a larger
1530 	 * transaction to create the inode.  Otherwise the encryption context is
1531 	 * being set on an existing inode in its own transaction.  Only in the
1532 	 * latter case should the "retry on ENOSPC" logic be used.
1533 	 */
1534 
1535 	if (handle) {
1536 		res = ext4_xattr_set_handle(handle, inode,
1537 					    EXT4_XATTR_INDEX_ENCRYPTION,
1538 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1539 					    ctx, len, 0);
1540 		if (!res) {
1541 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1542 			ext4_clear_inode_state(inode,
1543 					EXT4_STATE_MAY_INLINE_DATA);
1544 			/*
1545 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1546 			 * S_DAX may be disabled
1547 			 */
1548 			ext4_set_inode_flags(inode, false);
1549 		}
1550 		return res;
1551 	}
1552 
1553 	res = dquot_initialize(inode);
1554 	if (res)
1555 		return res;
1556 retry:
1557 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1558 				     &credits);
1559 	if (res)
1560 		return res;
1561 
1562 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1563 	if (IS_ERR(handle))
1564 		return PTR_ERR(handle);
1565 
1566 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1567 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1568 				    ctx, len, 0);
1569 	if (!res) {
1570 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1571 		/*
1572 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1573 		 * S_DAX may be disabled
1574 		 */
1575 		ext4_set_inode_flags(inode, false);
1576 		res = ext4_mark_inode_dirty(handle, inode);
1577 		if (res)
1578 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1579 	}
1580 	res2 = ext4_journal_stop(handle);
1581 
1582 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1583 		goto retry;
1584 	if (!res)
1585 		res = res2;
1586 	return res;
1587 }
1588 
1589 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1590 {
1591 	return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1592 }
1593 
1594 static bool ext4_has_stable_inodes(struct super_block *sb)
1595 {
1596 	return ext4_has_feature_stable_inodes(sb);
1597 }
1598 
1599 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1600 				       int *ino_bits_ret, int *lblk_bits_ret)
1601 {
1602 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1603 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1604 }
1605 
1606 static const struct fscrypt_operations ext4_cryptops = {
1607 	.key_prefix		= "ext4:",
1608 	.get_context		= ext4_get_context,
1609 	.set_context		= ext4_set_context,
1610 	.get_dummy_policy	= ext4_get_dummy_policy,
1611 	.empty_dir		= ext4_empty_dir,
1612 	.has_stable_inodes	= ext4_has_stable_inodes,
1613 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1614 };
1615 #endif
1616 
1617 #ifdef CONFIG_QUOTA
1618 static const char * const quotatypes[] = INITQFNAMES;
1619 #define QTYPE2NAME(t) (quotatypes[t])
1620 
1621 static int ext4_write_dquot(struct dquot *dquot);
1622 static int ext4_acquire_dquot(struct dquot *dquot);
1623 static int ext4_release_dquot(struct dquot *dquot);
1624 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1625 static int ext4_write_info(struct super_block *sb, int type);
1626 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1627 			 const struct path *path);
1628 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1629 			       size_t len, loff_t off);
1630 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1631 				const char *data, size_t len, loff_t off);
1632 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1633 			     unsigned int flags);
1634 
1635 static struct dquot **ext4_get_dquots(struct inode *inode)
1636 {
1637 	return EXT4_I(inode)->i_dquot;
1638 }
1639 
1640 static const struct dquot_operations ext4_quota_operations = {
1641 	.get_reserved_space	= ext4_get_reserved_space,
1642 	.write_dquot		= ext4_write_dquot,
1643 	.acquire_dquot		= ext4_acquire_dquot,
1644 	.release_dquot		= ext4_release_dquot,
1645 	.mark_dirty		= ext4_mark_dquot_dirty,
1646 	.write_info		= ext4_write_info,
1647 	.alloc_dquot		= dquot_alloc,
1648 	.destroy_dquot		= dquot_destroy,
1649 	.get_projid		= ext4_get_projid,
1650 	.get_inode_usage	= ext4_get_inode_usage,
1651 	.get_next_id		= dquot_get_next_id,
1652 };
1653 
1654 static const struct quotactl_ops ext4_qctl_operations = {
1655 	.quota_on	= ext4_quota_on,
1656 	.quota_off	= ext4_quota_off,
1657 	.quota_sync	= dquot_quota_sync,
1658 	.get_state	= dquot_get_state,
1659 	.set_info	= dquot_set_dqinfo,
1660 	.get_dqblk	= dquot_get_dqblk,
1661 	.set_dqblk	= dquot_set_dqblk,
1662 	.get_nextdqblk	= dquot_get_next_dqblk,
1663 };
1664 #endif
1665 
1666 static const struct super_operations ext4_sops = {
1667 	.alloc_inode	= ext4_alloc_inode,
1668 	.free_inode	= ext4_free_in_core_inode,
1669 	.destroy_inode	= ext4_destroy_inode,
1670 	.write_inode	= ext4_write_inode,
1671 	.dirty_inode	= ext4_dirty_inode,
1672 	.drop_inode	= ext4_drop_inode,
1673 	.evict_inode	= ext4_evict_inode,
1674 	.put_super	= ext4_put_super,
1675 	.sync_fs	= ext4_sync_fs,
1676 	.freeze_fs	= ext4_freeze,
1677 	.unfreeze_fs	= ext4_unfreeze,
1678 	.statfs		= ext4_statfs,
1679 	.show_options	= ext4_show_options,
1680 #ifdef CONFIG_QUOTA
1681 	.quota_read	= ext4_quota_read,
1682 	.quota_write	= ext4_quota_write,
1683 	.get_dquots	= ext4_get_dquots,
1684 #endif
1685 };
1686 
1687 static const struct export_operations ext4_export_ops = {
1688 	.fh_to_dentry = ext4_fh_to_dentry,
1689 	.fh_to_parent = ext4_fh_to_parent,
1690 	.get_parent = ext4_get_parent,
1691 	.commit_metadata = ext4_nfs_commit_metadata,
1692 };
1693 
1694 enum {
1695 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1696 	Opt_resgid, Opt_resuid, Opt_sb,
1697 	Opt_nouid32, Opt_debug, Opt_removed,
1698 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1699 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1700 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1701 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1702 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1703 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1704 	Opt_inlinecrypt,
1705 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1706 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1707 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1708 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1709 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1710 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1711 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1712 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1713 	Opt_dioread_nolock, Opt_dioread_lock,
1714 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1715 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1716 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1717 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1718 #ifdef CONFIG_EXT4_DEBUG
1719 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1720 #endif
1721 };
1722 
1723 static const struct constant_table ext4_param_errors[] = {
1724 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1725 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1726 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1727 	{}
1728 };
1729 
1730 static const struct constant_table ext4_param_data[] = {
1731 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1732 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1733 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1734 	{}
1735 };
1736 
1737 static const struct constant_table ext4_param_data_err[] = {
1738 	{"abort",	Opt_data_err_abort},
1739 	{"ignore",	Opt_data_err_ignore},
1740 	{}
1741 };
1742 
1743 static const struct constant_table ext4_param_jqfmt[] = {
1744 	{"vfsold",	QFMT_VFS_OLD},
1745 	{"vfsv0",	QFMT_VFS_V0},
1746 	{"vfsv1",	QFMT_VFS_V1},
1747 	{}
1748 };
1749 
1750 static const struct constant_table ext4_param_dax[] = {
1751 	{"always",	Opt_dax_always},
1752 	{"inode",	Opt_dax_inode},
1753 	{"never",	Opt_dax_never},
1754 	{}
1755 };
1756 
1757 /* String parameter that allows empty argument */
1758 #define fsparam_string_empty(NAME, OPT) \
1759 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1760 
1761 /*
1762  * Mount option specification
1763  * We don't use fsparam_flag_no because of the way we set the
1764  * options and the way we show them in _ext4_show_options(). To
1765  * keep the changes to a minimum, let's keep the negative options
1766  * separate for now.
1767  */
1768 static const struct fs_parameter_spec ext4_param_specs[] = {
1769 	fsparam_flag	("bsddf",		Opt_bsd_df),
1770 	fsparam_flag	("minixdf",		Opt_minix_df),
1771 	fsparam_flag	("grpid",		Opt_grpid),
1772 	fsparam_flag	("bsdgroups",		Opt_grpid),
1773 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1774 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1775 	fsparam_u32	("resgid",		Opt_resgid),
1776 	fsparam_u32	("resuid",		Opt_resuid),
1777 	fsparam_u32	("sb",			Opt_sb),
1778 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1779 	fsparam_flag	("nouid32",		Opt_nouid32),
1780 	fsparam_flag	("debug",		Opt_debug),
1781 	fsparam_flag	("oldalloc",		Opt_removed),
1782 	fsparam_flag	("orlov",		Opt_removed),
1783 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1784 	fsparam_flag	("nouser_xattr",	Opt_nouser_xattr),
1785 	fsparam_flag	("acl",			Opt_acl),
1786 	fsparam_flag	("noacl",		Opt_noacl),
1787 	fsparam_flag	("norecovery",		Opt_noload),
1788 	fsparam_flag	("noload",		Opt_noload),
1789 	fsparam_flag	("bh",			Opt_removed),
1790 	fsparam_flag	("nobh",		Opt_removed),
1791 	fsparam_u32	("commit",		Opt_commit),
1792 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1793 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1794 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1795 	fsparam_bdev	("journal_path",	Opt_journal_path),
1796 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1797 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1798 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1799 	fsparam_flag	("abort",		Opt_abort),
1800 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1801 	fsparam_enum	("data_err",		Opt_data_err,
1802 						ext4_param_data_err),
1803 	fsparam_string_empty
1804 			("usrjquota",		Opt_usrjquota),
1805 	fsparam_string_empty
1806 			("grpjquota",		Opt_grpjquota),
1807 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1808 	fsparam_flag	("grpquota",		Opt_grpquota),
1809 	fsparam_flag	("quota",		Opt_quota),
1810 	fsparam_flag	("noquota",		Opt_noquota),
1811 	fsparam_flag	("usrquota",		Opt_usrquota),
1812 	fsparam_flag	("prjquota",		Opt_prjquota),
1813 	fsparam_flag	("barrier",		Opt_barrier),
1814 	fsparam_u32	("barrier",		Opt_barrier),
1815 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1816 	fsparam_flag	("i_version",		Opt_i_version),
1817 	fsparam_flag	("dax",			Opt_dax),
1818 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1819 	fsparam_u32	("stripe",		Opt_stripe),
1820 	fsparam_flag	("delalloc",		Opt_delalloc),
1821 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1822 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1823 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1824 	fsparam_u32	("debug_want_extra_isize",
1825 						Opt_debug_want_extra_isize),
1826 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1827 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1828 	fsparam_flag	("block_validity",	Opt_block_validity),
1829 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1830 	fsparam_u32	("inode_readahead_blks",
1831 						Opt_inode_readahead_blks),
1832 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1833 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1834 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1835 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1836 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1837 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1838 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1839 	fsparam_flag	("discard",		Opt_discard),
1840 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1841 	fsparam_u32	("init_itable",		Opt_init_itable),
1842 	fsparam_flag	("init_itable",		Opt_init_itable),
1843 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1844 #ifdef CONFIG_EXT4_DEBUG
1845 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1846 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1847 #endif
1848 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1849 	fsparam_flag	("test_dummy_encryption",
1850 						Opt_test_dummy_encryption),
1851 	fsparam_string	("test_dummy_encryption",
1852 						Opt_test_dummy_encryption),
1853 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1854 	fsparam_flag	("nombcache",		Opt_nombcache),
1855 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1856 	fsparam_flag	("prefetch_block_bitmaps",
1857 						Opt_removed),
1858 	fsparam_flag	("no_prefetch_block_bitmaps",
1859 						Opt_no_prefetch_block_bitmaps),
1860 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1861 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1862 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1863 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1864 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1865 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1866 	{}
1867 };
1868 
1869 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1870 #define DEFAULT_MB_OPTIMIZE_SCAN	(-1)
1871 
1872 static const char deprecated_msg[] =
1873 	"Mount option \"%s\" will be removed by %s\n"
1874 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1875 
1876 #define MOPT_SET	0x0001
1877 #define MOPT_CLEAR	0x0002
1878 #define MOPT_NOSUPPORT	0x0004
1879 #define MOPT_EXPLICIT	0x0008
1880 #ifdef CONFIG_QUOTA
1881 #define MOPT_Q		0
1882 #define MOPT_QFMT	0x0010
1883 #else
1884 #define MOPT_Q		MOPT_NOSUPPORT
1885 #define MOPT_QFMT	MOPT_NOSUPPORT
1886 #endif
1887 #define MOPT_NO_EXT2	0x0020
1888 #define MOPT_NO_EXT3	0x0040
1889 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1890 #define MOPT_SKIP	0x0080
1891 #define	MOPT_2		0x0100
1892 
1893 static const struct mount_opts {
1894 	int	token;
1895 	int	mount_opt;
1896 	int	flags;
1897 } ext4_mount_opts[] = {
1898 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1899 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1900 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1901 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1902 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1903 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1904 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1905 	 MOPT_EXT4_ONLY | MOPT_SET},
1906 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1907 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1908 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1909 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1910 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1911 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1912 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1913 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1914 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1915 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1916 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1917 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1918 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1919 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1920 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1921 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1922 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1923 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1924 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1925 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1926 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1927 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1928 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1929 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1930 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1931 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1932 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1933 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1934 	{Opt_data, 0, MOPT_NO_EXT2},
1935 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1936 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1937 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1938 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1939 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1940 #else
1941 	{Opt_acl, 0, MOPT_NOSUPPORT},
1942 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1943 #endif
1944 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1945 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1946 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1947 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1948 							MOPT_SET | MOPT_Q},
1949 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1950 							MOPT_SET | MOPT_Q},
1951 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1952 							MOPT_SET | MOPT_Q},
1953 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1954 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1955 							MOPT_CLEAR | MOPT_Q},
1956 	{Opt_usrjquota, 0, MOPT_Q},
1957 	{Opt_grpjquota, 0, MOPT_Q},
1958 	{Opt_jqfmt, 0, MOPT_QFMT},
1959 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1960 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1961 	 MOPT_SET},
1962 #ifdef CONFIG_EXT4_DEBUG
1963 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1964 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1965 #endif
1966 	{Opt_err, 0, 0}
1967 };
1968 
1969 #if IS_ENABLED(CONFIG_UNICODE)
1970 static const struct ext4_sb_encodings {
1971 	__u16 magic;
1972 	char *name;
1973 	unsigned int version;
1974 } ext4_sb_encoding_map[] = {
1975 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1976 };
1977 
1978 static const struct ext4_sb_encodings *
1979 ext4_sb_read_encoding(const struct ext4_super_block *es)
1980 {
1981 	__u16 magic = le16_to_cpu(es->s_encoding);
1982 	int i;
1983 
1984 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1985 		if (magic == ext4_sb_encoding_map[i].magic)
1986 			return &ext4_sb_encoding_map[i];
1987 
1988 	return NULL;
1989 }
1990 #endif
1991 
1992 static int ext4_set_test_dummy_encryption(struct super_block *sb, char *arg)
1993 {
1994 #ifdef CONFIG_FS_ENCRYPTION
1995 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1996 	int err;
1997 
1998 	err = fscrypt_set_test_dummy_encryption(sb, arg,
1999 						&sbi->s_dummy_enc_policy);
2000 	if (err) {
2001 		ext4_msg(sb, KERN_WARNING,
2002 			 "Error while setting test dummy encryption [%d]", err);
2003 		return err;
2004 	}
2005 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2006 #endif
2007 	return 0;
2008 }
2009 
2010 #define EXT4_SPEC_JQUOTA			(1 <<  0)
2011 #define EXT4_SPEC_JQFMT				(1 <<  1)
2012 #define EXT4_SPEC_DATAJ				(1 <<  2)
2013 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
2014 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
2015 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
2016 #define EXT4_SPEC_DUMMY_ENCRYPTION		(1 <<  6)
2017 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
2018 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
2019 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
2020 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
2021 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
2022 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
2023 #define EXT4_SPEC_s_stripe			(1 << 13)
2024 #define EXT4_SPEC_s_resuid			(1 << 14)
2025 #define EXT4_SPEC_s_resgid			(1 << 15)
2026 #define EXT4_SPEC_s_commit_interval		(1 << 16)
2027 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
2028 #define EXT4_SPEC_s_sb_block			(1 << 18)
2029 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
2030 
2031 struct ext4_fs_context {
2032 	char		*s_qf_names[EXT4_MAXQUOTAS];
2033 	char		*test_dummy_enc_arg;
2034 	int		s_jquota_fmt;	/* Format of quota to use */
2035 #ifdef CONFIG_EXT4_DEBUG
2036 	int s_fc_debug_max_replay;
2037 #endif
2038 	unsigned short	qname_spec;
2039 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
2040 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
2041 	unsigned long	journal_devnum;
2042 	unsigned long	s_commit_interval;
2043 	unsigned long	s_stripe;
2044 	unsigned int	s_inode_readahead_blks;
2045 	unsigned int	s_want_extra_isize;
2046 	unsigned int	s_li_wait_mult;
2047 	unsigned int	s_max_dir_size_kb;
2048 	unsigned int	journal_ioprio;
2049 	unsigned int	vals_s_mount_opt;
2050 	unsigned int	mask_s_mount_opt;
2051 	unsigned int	vals_s_mount_opt2;
2052 	unsigned int	mask_s_mount_opt2;
2053 	unsigned long	vals_s_mount_flags;
2054 	unsigned long	mask_s_mount_flags;
2055 	unsigned int	opt_flags;	/* MOPT flags */
2056 	unsigned int	spec;
2057 	u32		s_max_batch_time;
2058 	u32		s_min_batch_time;
2059 	kuid_t		s_resuid;
2060 	kgid_t		s_resgid;
2061 	ext4_fsblk_t	s_sb_block;
2062 };
2063 
2064 static void ext4_fc_free(struct fs_context *fc)
2065 {
2066 	struct ext4_fs_context *ctx = fc->fs_private;
2067 	int i;
2068 
2069 	if (!ctx)
2070 		return;
2071 
2072 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2073 		kfree(ctx->s_qf_names[i]);
2074 
2075 	kfree(ctx->test_dummy_enc_arg);
2076 	kfree(ctx);
2077 }
2078 
2079 int ext4_init_fs_context(struct fs_context *fc)
2080 {
2081 	struct ext4_fs_context *ctx;
2082 
2083 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2084 	if (!ctx)
2085 		return -ENOMEM;
2086 
2087 	fc->fs_private = ctx;
2088 	fc->ops = &ext4_context_ops;
2089 
2090 	return 0;
2091 }
2092 
2093 #ifdef CONFIG_QUOTA
2094 /*
2095  * Note the name of the specified quota file.
2096  */
2097 static int note_qf_name(struct fs_context *fc, int qtype,
2098 		       struct fs_parameter *param)
2099 {
2100 	struct ext4_fs_context *ctx = fc->fs_private;
2101 	char *qname;
2102 
2103 	if (param->size < 1) {
2104 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2105 		return -EINVAL;
2106 	}
2107 	if (strchr(param->string, '/')) {
2108 		ext4_msg(NULL, KERN_ERR,
2109 			 "quotafile must be on filesystem root");
2110 		return -EINVAL;
2111 	}
2112 	if (ctx->s_qf_names[qtype]) {
2113 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2114 			ext4_msg(NULL, KERN_ERR,
2115 				 "%s quota file already specified",
2116 				 QTYPE2NAME(qtype));
2117 			return -EINVAL;
2118 		}
2119 		return 0;
2120 	}
2121 
2122 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2123 	if (!qname) {
2124 		ext4_msg(NULL, KERN_ERR,
2125 			 "Not enough memory for storing quotafile name");
2126 		return -ENOMEM;
2127 	}
2128 	ctx->s_qf_names[qtype] = qname;
2129 	ctx->qname_spec |= 1 << qtype;
2130 	ctx->spec |= EXT4_SPEC_JQUOTA;
2131 	return 0;
2132 }
2133 
2134 /*
2135  * Clear the name of the specified quota file.
2136  */
2137 static int unnote_qf_name(struct fs_context *fc, int qtype)
2138 {
2139 	struct ext4_fs_context *ctx = fc->fs_private;
2140 
2141 	if (ctx->s_qf_names[qtype])
2142 		kfree(ctx->s_qf_names[qtype]);
2143 
2144 	ctx->s_qf_names[qtype] = NULL;
2145 	ctx->qname_spec |= 1 << qtype;
2146 	ctx->spec |= EXT4_SPEC_JQUOTA;
2147 	return 0;
2148 }
2149 #endif
2150 
2151 #define EXT4_SET_CTX(name)						\
2152 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2153 				  unsigned long flag)			\
2154 {									\
2155 	ctx->mask_s_##name |= flag;					\
2156 	ctx->vals_s_##name |= flag;					\
2157 }
2158 
2159 #define EXT4_CLEAR_CTX(name)						\
2160 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2161 				    unsigned long flag)			\
2162 {									\
2163 	ctx->mask_s_##name |= flag;					\
2164 	ctx->vals_s_##name &= ~flag;					\
2165 }
2166 
2167 #define EXT4_TEST_CTX(name)						\
2168 static inline unsigned long						\
2169 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2170 {									\
2171 	return (ctx->vals_s_##name & flag);				\
2172 }
2173 
2174 EXT4_SET_CTX(flags); /* set only */
2175 EXT4_SET_CTX(mount_opt);
2176 EXT4_CLEAR_CTX(mount_opt);
2177 EXT4_TEST_CTX(mount_opt);
2178 EXT4_SET_CTX(mount_opt2);
2179 EXT4_CLEAR_CTX(mount_opt2);
2180 EXT4_TEST_CTX(mount_opt2);
2181 
2182 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2183 {
2184 	set_bit(bit, &ctx->mask_s_mount_flags);
2185 	set_bit(bit, &ctx->vals_s_mount_flags);
2186 }
2187 
2188 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2189 {
2190 	struct ext4_fs_context *ctx = fc->fs_private;
2191 	struct fs_parse_result result;
2192 	const struct mount_opts *m;
2193 	int is_remount;
2194 	kuid_t uid;
2195 	kgid_t gid;
2196 	int token;
2197 
2198 	token = fs_parse(fc, ext4_param_specs, param, &result);
2199 	if (token < 0)
2200 		return token;
2201 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2202 
2203 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2204 		if (token == m->token)
2205 			break;
2206 
2207 	ctx->opt_flags |= m->flags;
2208 
2209 	if (m->flags & MOPT_EXPLICIT) {
2210 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2211 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2212 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2213 			ctx_set_mount_opt2(ctx,
2214 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2215 		} else
2216 			return -EINVAL;
2217 	}
2218 
2219 	if (m->flags & MOPT_NOSUPPORT) {
2220 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2221 			 param->key);
2222 		return 0;
2223 	}
2224 
2225 	switch (token) {
2226 #ifdef CONFIG_QUOTA
2227 	case Opt_usrjquota:
2228 		if (!*param->string)
2229 			return unnote_qf_name(fc, USRQUOTA);
2230 		else
2231 			return note_qf_name(fc, USRQUOTA, param);
2232 	case Opt_grpjquota:
2233 		if (!*param->string)
2234 			return unnote_qf_name(fc, GRPQUOTA);
2235 		else
2236 			return note_qf_name(fc, GRPQUOTA, param);
2237 #endif
2238 	case Opt_noacl:
2239 	case Opt_nouser_xattr:
2240 		ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "3.5");
2241 		break;
2242 	case Opt_sb:
2243 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2244 			ext4_msg(NULL, KERN_WARNING,
2245 				 "Ignoring %s option on remount", param->key);
2246 		} else {
2247 			ctx->s_sb_block = result.uint_32;
2248 			ctx->spec |= EXT4_SPEC_s_sb_block;
2249 		}
2250 		return 0;
2251 	case Opt_removed:
2252 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2253 			 param->key);
2254 		return 0;
2255 	case Opt_abort:
2256 		ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2257 		return 0;
2258 	case Opt_i_version:
2259 		ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "5.20");
2260 		ext4_msg(NULL, KERN_WARNING, "Use iversion instead\n");
2261 		ctx_set_flags(ctx, SB_I_VERSION);
2262 		return 0;
2263 	case Opt_inlinecrypt:
2264 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2265 		ctx_set_flags(ctx, SB_INLINECRYPT);
2266 #else
2267 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2268 #endif
2269 		return 0;
2270 	case Opt_errors:
2271 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2272 		ctx_set_mount_opt(ctx, result.uint_32);
2273 		return 0;
2274 #ifdef CONFIG_QUOTA
2275 	case Opt_jqfmt:
2276 		ctx->s_jquota_fmt = result.uint_32;
2277 		ctx->spec |= EXT4_SPEC_JQFMT;
2278 		return 0;
2279 #endif
2280 	case Opt_data:
2281 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2282 		ctx_set_mount_opt(ctx, result.uint_32);
2283 		ctx->spec |= EXT4_SPEC_DATAJ;
2284 		return 0;
2285 	case Opt_commit:
2286 		if (result.uint_32 == 0)
2287 			ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2288 		else if (result.uint_32 > INT_MAX / HZ) {
2289 			ext4_msg(NULL, KERN_ERR,
2290 				 "Invalid commit interval %d, "
2291 				 "must be smaller than %d",
2292 				 result.uint_32, INT_MAX / HZ);
2293 			return -EINVAL;
2294 		}
2295 		ctx->s_commit_interval = HZ * result.uint_32;
2296 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2297 		return 0;
2298 	case Opt_debug_want_extra_isize:
2299 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2300 			ext4_msg(NULL, KERN_ERR,
2301 				 "Invalid want_extra_isize %d", result.uint_32);
2302 			return -EINVAL;
2303 		}
2304 		ctx->s_want_extra_isize = result.uint_32;
2305 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2306 		return 0;
2307 	case Opt_max_batch_time:
2308 		ctx->s_max_batch_time = result.uint_32;
2309 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2310 		return 0;
2311 	case Opt_min_batch_time:
2312 		ctx->s_min_batch_time = result.uint_32;
2313 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2314 		return 0;
2315 	case Opt_inode_readahead_blks:
2316 		if (result.uint_32 &&
2317 		    (result.uint_32 > (1 << 30) ||
2318 		     !is_power_of_2(result.uint_32))) {
2319 			ext4_msg(NULL, KERN_ERR,
2320 				 "EXT4-fs: inode_readahead_blks must be "
2321 				 "0 or a power of 2 smaller than 2^31");
2322 			return -EINVAL;
2323 		}
2324 		ctx->s_inode_readahead_blks = result.uint_32;
2325 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2326 		return 0;
2327 	case Opt_init_itable:
2328 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2329 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2330 		if (param->type == fs_value_is_string)
2331 			ctx->s_li_wait_mult = result.uint_32;
2332 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2333 		return 0;
2334 	case Opt_max_dir_size_kb:
2335 		ctx->s_max_dir_size_kb = result.uint_32;
2336 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2337 		return 0;
2338 #ifdef CONFIG_EXT4_DEBUG
2339 	case Opt_fc_debug_max_replay:
2340 		ctx->s_fc_debug_max_replay = result.uint_32;
2341 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2342 		return 0;
2343 #endif
2344 	case Opt_stripe:
2345 		ctx->s_stripe = result.uint_32;
2346 		ctx->spec |= EXT4_SPEC_s_stripe;
2347 		return 0;
2348 	case Opt_resuid:
2349 		uid = make_kuid(current_user_ns(), result.uint_32);
2350 		if (!uid_valid(uid)) {
2351 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2352 				 result.uint_32);
2353 			return -EINVAL;
2354 		}
2355 		ctx->s_resuid = uid;
2356 		ctx->spec |= EXT4_SPEC_s_resuid;
2357 		return 0;
2358 	case Opt_resgid:
2359 		gid = make_kgid(current_user_ns(), result.uint_32);
2360 		if (!gid_valid(gid)) {
2361 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2362 				 result.uint_32);
2363 			return -EINVAL;
2364 		}
2365 		ctx->s_resgid = gid;
2366 		ctx->spec |= EXT4_SPEC_s_resgid;
2367 		return 0;
2368 	case Opt_journal_dev:
2369 		if (is_remount) {
2370 			ext4_msg(NULL, KERN_ERR,
2371 				 "Cannot specify journal on remount");
2372 			return -EINVAL;
2373 		}
2374 		ctx->journal_devnum = result.uint_32;
2375 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2376 		return 0;
2377 	case Opt_journal_path:
2378 	{
2379 		struct inode *journal_inode;
2380 		struct path path;
2381 		int error;
2382 
2383 		if (is_remount) {
2384 			ext4_msg(NULL, KERN_ERR,
2385 				 "Cannot specify journal on remount");
2386 			return -EINVAL;
2387 		}
2388 
2389 		error = fs_lookup_param(fc, param, 1, &path);
2390 		if (error) {
2391 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2392 				 "journal device path");
2393 			return -EINVAL;
2394 		}
2395 
2396 		journal_inode = d_inode(path.dentry);
2397 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2398 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2399 		path_put(&path);
2400 		return 0;
2401 	}
2402 	case Opt_journal_ioprio:
2403 		if (result.uint_32 > 7) {
2404 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2405 				 " (must be 0-7)");
2406 			return -EINVAL;
2407 		}
2408 		ctx->journal_ioprio =
2409 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2410 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2411 		return 0;
2412 	case Opt_test_dummy_encryption:
2413 #ifdef CONFIG_FS_ENCRYPTION
2414 		if (param->type == fs_value_is_flag) {
2415 			ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
2416 			ctx->test_dummy_enc_arg = NULL;
2417 			return 0;
2418 		}
2419 		if (*param->string &&
2420 		    !(!strcmp(param->string, "v1") ||
2421 		      !strcmp(param->string, "v2"))) {
2422 			ext4_msg(NULL, KERN_WARNING,
2423 				 "Value of option \"%s\" is unrecognized",
2424 				 param->key);
2425 			return -EINVAL;
2426 		}
2427 		ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
2428 		ctx->test_dummy_enc_arg = kmemdup_nul(param->string, param->size,
2429 						      GFP_KERNEL);
2430 #else
2431 		ext4_msg(NULL, KERN_WARNING,
2432 			 "Test dummy encryption mount option ignored");
2433 #endif
2434 		return 0;
2435 	case Opt_dax:
2436 	case Opt_dax_type:
2437 #ifdef CONFIG_FS_DAX
2438 	{
2439 		int type = (token == Opt_dax) ?
2440 			   Opt_dax : result.uint_32;
2441 
2442 		switch (type) {
2443 		case Opt_dax:
2444 		case Opt_dax_always:
2445 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2446 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2447 			break;
2448 		case Opt_dax_never:
2449 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2450 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2451 			break;
2452 		case Opt_dax_inode:
2453 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2454 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2455 			/* Strictly for printing options */
2456 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2457 			break;
2458 		}
2459 		return 0;
2460 	}
2461 #else
2462 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2463 		return -EINVAL;
2464 #endif
2465 	case Opt_data_err:
2466 		if (result.uint_32 == Opt_data_err_abort)
2467 			ctx_set_mount_opt(ctx, m->mount_opt);
2468 		else if (result.uint_32 == Opt_data_err_ignore)
2469 			ctx_clear_mount_opt(ctx, m->mount_opt);
2470 		return 0;
2471 	case Opt_mb_optimize_scan:
2472 		if (result.int_32 == 1) {
2473 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2474 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2475 		} else if (result.int_32 == 0) {
2476 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2477 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2478 		} else {
2479 			ext4_msg(NULL, KERN_WARNING,
2480 				 "mb_optimize_scan should be set to 0 or 1.");
2481 			return -EINVAL;
2482 		}
2483 		return 0;
2484 	}
2485 
2486 	/*
2487 	 * At this point we should only be getting options requiring MOPT_SET,
2488 	 * or MOPT_CLEAR. Anything else is a bug
2489 	 */
2490 	if (m->token == Opt_err) {
2491 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2492 			 param->key);
2493 		WARN_ON(1);
2494 		return -EINVAL;
2495 	}
2496 
2497 	else {
2498 		unsigned int set = 0;
2499 
2500 		if ((param->type == fs_value_is_flag) ||
2501 		    result.uint_32 > 0)
2502 			set = 1;
2503 
2504 		if (m->flags & MOPT_CLEAR)
2505 			set = !set;
2506 		else if (unlikely(!(m->flags & MOPT_SET))) {
2507 			ext4_msg(NULL, KERN_WARNING,
2508 				 "buggy handling of option %s",
2509 				 param->key);
2510 			WARN_ON(1);
2511 			return -EINVAL;
2512 		}
2513 		if (m->flags & MOPT_2) {
2514 			if (set != 0)
2515 				ctx_set_mount_opt2(ctx, m->mount_opt);
2516 			else
2517 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2518 		} else {
2519 			if (set != 0)
2520 				ctx_set_mount_opt(ctx, m->mount_opt);
2521 			else
2522 				ctx_clear_mount_opt(ctx, m->mount_opt);
2523 		}
2524 	}
2525 
2526 	return 0;
2527 }
2528 
2529 static int parse_options(struct fs_context *fc, char *options)
2530 {
2531 	struct fs_parameter param;
2532 	int ret;
2533 	char *key;
2534 
2535 	if (!options)
2536 		return 0;
2537 
2538 	while ((key = strsep(&options, ",")) != NULL) {
2539 		if (*key) {
2540 			size_t v_len = 0;
2541 			char *value = strchr(key, '=');
2542 
2543 			param.type = fs_value_is_flag;
2544 			param.string = NULL;
2545 
2546 			if (value) {
2547 				if (value == key)
2548 					continue;
2549 
2550 				*value++ = 0;
2551 				v_len = strlen(value);
2552 				param.string = kmemdup_nul(value, v_len,
2553 							   GFP_KERNEL);
2554 				if (!param.string)
2555 					return -ENOMEM;
2556 				param.type = fs_value_is_string;
2557 			}
2558 
2559 			param.key = key;
2560 			param.size = v_len;
2561 
2562 			ret = ext4_parse_param(fc, &param);
2563 			if (param.string)
2564 				kfree(param.string);
2565 			if (ret < 0)
2566 				return ret;
2567 		}
2568 	}
2569 
2570 	ret = ext4_validate_options(fc);
2571 	if (ret < 0)
2572 		return ret;
2573 
2574 	return 0;
2575 }
2576 
2577 static int parse_apply_sb_mount_options(struct super_block *sb,
2578 					struct ext4_fs_context *m_ctx)
2579 {
2580 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2581 	char *s_mount_opts = NULL;
2582 	struct ext4_fs_context *s_ctx = NULL;
2583 	struct fs_context *fc = NULL;
2584 	int ret = -ENOMEM;
2585 
2586 	if (!sbi->s_es->s_mount_opts[0])
2587 		return 0;
2588 
2589 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2590 				sizeof(sbi->s_es->s_mount_opts),
2591 				GFP_KERNEL);
2592 	if (!s_mount_opts)
2593 		return ret;
2594 
2595 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2596 	if (!fc)
2597 		goto out_free;
2598 
2599 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2600 	if (!s_ctx)
2601 		goto out_free;
2602 
2603 	fc->fs_private = s_ctx;
2604 	fc->s_fs_info = sbi;
2605 
2606 	ret = parse_options(fc, s_mount_opts);
2607 	if (ret < 0)
2608 		goto parse_failed;
2609 
2610 	ret = ext4_check_opt_consistency(fc, sb);
2611 	if (ret < 0) {
2612 parse_failed:
2613 		ext4_msg(sb, KERN_WARNING,
2614 			 "failed to parse options in superblock: %s",
2615 			 s_mount_opts);
2616 		ret = 0;
2617 		goto out_free;
2618 	}
2619 
2620 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2621 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2622 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2623 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2624 
2625 	ret = ext4_apply_options(fc, sb);
2626 
2627 out_free:
2628 	kfree(s_ctx);
2629 	kfree(fc);
2630 	kfree(s_mount_opts);
2631 	return ret;
2632 }
2633 
2634 static void ext4_apply_quota_options(struct fs_context *fc,
2635 				     struct super_block *sb)
2636 {
2637 #ifdef CONFIG_QUOTA
2638 	bool quota_feature = ext4_has_feature_quota(sb);
2639 	struct ext4_fs_context *ctx = fc->fs_private;
2640 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2641 	char *qname;
2642 	int i;
2643 
2644 	if (quota_feature)
2645 		return;
2646 
2647 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2648 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2649 			if (!(ctx->qname_spec & (1 << i)))
2650 				continue;
2651 
2652 			qname = ctx->s_qf_names[i]; /* May be NULL */
2653 			if (qname)
2654 				set_opt(sb, QUOTA);
2655 			ctx->s_qf_names[i] = NULL;
2656 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2657 						lockdep_is_held(&sb->s_umount));
2658 			if (qname)
2659 				kfree_rcu(qname);
2660 		}
2661 	}
2662 
2663 	if (ctx->spec & EXT4_SPEC_JQFMT)
2664 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2665 #endif
2666 }
2667 
2668 /*
2669  * Check quota settings consistency.
2670  */
2671 static int ext4_check_quota_consistency(struct fs_context *fc,
2672 					struct super_block *sb)
2673 {
2674 #ifdef CONFIG_QUOTA
2675 	struct ext4_fs_context *ctx = fc->fs_private;
2676 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2677 	bool quota_feature = ext4_has_feature_quota(sb);
2678 	bool quota_loaded = sb_any_quota_loaded(sb);
2679 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2680 	int quota_flags, i;
2681 
2682 	/*
2683 	 * We do the test below only for project quotas. 'usrquota' and
2684 	 * 'grpquota' mount options are allowed even without quota feature
2685 	 * to support legacy quotas in quota files.
2686 	 */
2687 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2688 	    !ext4_has_feature_project(sb)) {
2689 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2690 			 "Cannot enable project quota enforcement.");
2691 		return -EINVAL;
2692 	}
2693 
2694 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2695 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2696 	if (quota_loaded &&
2697 	    ctx->mask_s_mount_opt & quota_flags &&
2698 	    !ctx_test_mount_opt(ctx, quota_flags))
2699 		goto err_quota_change;
2700 
2701 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2702 
2703 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2704 			if (!(ctx->qname_spec & (1 << i)))
2705 				continue;
2706 
2707 			if (quota_loaded &&
2708 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2709 				goto err_jquota_change;
2710 
2711 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2712 			    strcmp(get_qf_name(sb, sbi, i),
2713 				   ctx->s_qf_names[i]) != 0)
2714 				goto err_jquota_specified;
2715 		}
2716 
2717 		if (quota_feature) {
2718 			ext4_msg(NULL, KERN_INFO,
2719 				 "Journaled quota options ignored when "
2720 				 "QUOTA feature is enabled");
2721 			return 0;
2722 		}
2723 	}
2724 
2725 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2726 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2727 			goto err_jquota_change;
2728 		if (quota_feature) {
2729 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2730 				 "ignored when QUOTA feature is enabled");
2731 			return 0;
2732 		}
2733 	}
2734 
2735 	/* Make sure we don't mix old and new quota format */
2736 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2737 		       ctx->s_qf_names[USRQUOTA]);
2738 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2739 		       ctx->s_qf_names[GRPQUOTA]);
2740 
2741 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2742 		    test_opt(sb, USRQUOTA));
2743 
2744 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2745 		    test_opt(sb, GRPQUOTA));
2746 
2747 	if (usr_qf_name) {
2748 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2749 		usrquota = false;
2750 	}
2751 	if (grp_qf_name) {
2752 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2753 		grpquota = false;
2754 	}
2755 
2756 	if (usr_qf_name || grp_qf_name) {
2757 		if (usrquota || grpquota) {
2758 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2759 				 "format mixing");
2760 			return -EINVAL;
2761 		}
2762 
2763 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2764 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2765 				 "not specified");
2766 			return -EINVAL;
2767 		}
2768 	}
2769 
2770 	return 0;
2771 
2772 err_quota_change:
2773 	ext4_msg(NULL, KERN_ERR,
2774 		 "Cannot change quota options when quota turned on");
2775 	return -EINVAL;
2776 err_jquota_change:
2777 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2778 		 "options when quota turned on");
2779 	return -EINVAL;
2780 err_jquota_specified:
2781 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2782 		 QTYPE2NAME(i));
2783 	return -EINVAL;
2784 #else
2785 	return 0;
2786 #endif
2787 }
2788 
2789 static int ext4_check_opt_consistency(struct fs_context *fc,
2790 				      struct super_block *sb)
2791 {
2792 	struct ext4_fs_context *ctx = fc->fs_private;
2793 	struct ext4_sb_info *sbi = fc->s_fs_info;
2794 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2795 
2796 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2797 		ext4_msg(NULL, KERN_ERR,
2798 			 "Mount option(s) incompatible with ext2");
2799 		return -EINVAL;
2800 	}
2801 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2802 		ext4_msg(NULL, KERN_ERR,
2803 			 "Mount option(s) incompatible with ext3");
2804 		return -EINVAL;
2805 	}
2806 
2807 	if (ctx->s_want_extra_isize >
2808 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2809 		ext4_msg(NULL, KERN_ERR,
2810 			 "Invalid want_extra_isize %d",
2811 			 ctx->s_want_extra_isize);
2812 		return -EINVAL;
2813 	}
2814 
2815 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2816 		int blocksize =
2817 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2818 		if (blocksize < PAGE_SIZE)
2819 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2820 				 "experimental mount option 'dioread_nolock' "
2821 				 "for blocksize < PAGE_SIZE");
2822 	}
2823 
2824 #ifdef CONFIG_FS_ENCRYPTION
2825 	/*
2826 	 * This mount option is just for testing, and it's not worthwhile to
2827 	 * implement the extra complexity (e.g. RCU protection) that would be
2828 	 * needed to allow it to be set or changed during remount.  We do allow
2829 	 * it to be specified during remount, but only if there is no change.
2830 	 */
2831 	if ((ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION) &&
2832 	    is_remount && !sbi->s_dummy_enc_policy.policy) {
2833 		ext4_msg(NULL, KERN_WARNING,
2834 			 "Can't set test_dummy_encryption on remount");
2835 		return -1;
2836 	}
2837 #endif
2838 
2839 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2840 		if (!sbi->s_journal) {
2841 			ext4_msg(NULL, KERN_WARNING,
2842 				 "Remounting file system with no journal "
2843 				 "so ignoring journalled data option");
2844 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2845 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2846 			   test_opt(sb, DATA_FLAGS)) {
2847 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2848 				 "on remount");
2849 			return -EINVAL;
2850 		}
2851 	}
2852 
2853 	if (is_remount) {
2854 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2855 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2856 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2857 				 "both data=journal and dax");
2858 			return -EINVAL;
2859 		}
2860 
2861 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2862 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2863 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2864 fail_dax_change_remount:
2865 			ext4_msg(NULL, KERN_ERR, "can't change "
2866 				 "dax mount option while remounting");
2867 			return -EINVAL;
2868 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2869 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2870 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2871 			goto fail_dax_change_remount;
2872 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2873 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2874 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2875 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2876 			goto fail_dax_change_remount;
2877 		}
2878 	}
2879 
2880 	return ext4_check_quota_consistency(fc, sb);
2881 }
2882 
2883 static int ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2884 {
2885 	struct ext4_fs_context *ctx = fc->fs_private;
2886 	struct ext4_sb_info *sbi = fc->s_fs_info;
2887 	int ret = 0;
2888 
2889 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2890 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2891 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2892 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2893 	sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2894 	sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2895 	sb->s_flags &= ~ctx->mask_s_flags;
2896 	sb->s_flags |= ctx->vals_s_flags;
2897 
2898 	/*
2899 	 * i_version differs from common mount option iversion so we have
2900 	 * to let vfs know that it was set, otherwise it would get cleared
2901 	 * on remount
2902 	 */
2903 	if (ctx->mask_s_flags & SB_I_VERSION)
2904 		fc->sb_flags |= SB_I_VERSION;
2905 
2906 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2907 	APPLY(s_commit_interval);
2908 	APPLY(s_stripe);
2909 	APPLY(s_max_batch_time);
2910 	APPLY(s_min_batch_time);
2911 	APPLY(s_want_extra_isize);
2912 	APPLY(s_inode_readahead_blks);
2913 	APPLY(s_max_dir_size_kb);
2914 	APPLY(s_li_wait_mult);
2915 	APPLY(s_resgid);
2916 	APPLY(s_resuid);
2917 
2918 #ifdef CONFIG_EXT4_DEBUG
2919 	APPLY(s_fc_debug_max_replay);
2920 #endif
2921 
2922 	ext4_apply_quota_options(fc, sb);
2923 
2924 	if (ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION)
2925 		ret = ext4_set_test_dummy_encryption(sb, ctx->test_dummy_enc_arg);
2926 
2927 	return ret;
2928 }
2929 
2930 
2931 static int ext4_validate_options(struct fs_context *fc)
2932 {
2933 #ifdef CONFIG_QUOTA
2934 	struct ext4_fs_context *ctx = fc->fs_private;
2935 	char *usr_qf_name, *grp_qf_name;
2936 
2937 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2938 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2939 
2940 	if (usr_qf_name || grp_qf_name) {
2941 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2942 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2943 
2944 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2945 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2946 
2947 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2948 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2949 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2950 				 "format mixing");
2951 			return -EINVAL;
2952 		}
2953 	}
2954 #endif
2955 	return 1;
2956 }
2957 
2958 static inline void ext4_show_quota_options(struct seq_file *seq,
2959 					   struct super_block *sb)
2960 {
2961 #if defined(CONFIG_QUOTA)
2962 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2963 	char *usr_qf_name, *grp_qf_name;
2964 
2965 	if (sbi->s_jquota_fmt) {
2966 		char *fmtname = "";
2967 
2968 		switch (sbi->s_jquota_fmt) {
2969 		case QFMT_VFS_OLD:
2970 			fmtname = "vfsold";
2971 			break;
2972 		case QFMT_VFS_V0:
2973 			fmtname = "vfsv0";
2974 			break;
2975 		case QFMT_VFS_V1:
2976 			fmtname = "vfsv1";
2977 			break;
2978 		}
2979 		seq_printf(seq, ",jqfmt=%s", fmtname);
2980 	}
2981 
2982 	rcu_read_lock();
2983 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2984 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2985 	if (usr_qf_name)
2986 		seq_show_option(seq, "usrjquota", usr_qf_name);
2987 	if (grp_qf_name)
2988 		seq_show_option(seq, "grpjquota", grp_qf_name);
2989 	rcu_read_unlock();
2990 #endif
2991 }
2992 
2993 static const char *token2str(int token)
2994 {
2995 	const struct fs_parameter_spec *spec;
2996 
2997 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2998 		if (spec->opt == token && !spec->type)
2999 			break;
3000 	return spec->name;
3001 }
3002 
3003 /*
3004  * Show an option if
3005  *  - it's set to a non-default value OR
3006  *  - if the per-sb default is different from the global default
3007  */
3008 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
3009 			      int nodefs)
3010 {
3011 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3012 	struct ext4_super_block *es = sbi->s_es;
3013 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
3014 	const struct mount_opts *m;
3015 	char sep = nodefs ? '\n' : ',';
3016 
3017 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
3018 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
3019 
3020 	if (sbi->s_sb_block != 1)
3021 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
3022 
3023 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
3024 		int want_set = m->flags & MOPT_SET;
3025 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
3026 		    m->flags & MOPT_SKIP)
3027 			continue;
3028 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
3029 			continue; /* skip if same as the default */
3030 		if ((want_set &&
3031 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
3032 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
3033 			continue; /* select Opt_noFoo vs Opt_Foo */
3034 		SEQ_OPTS_PRINT("%s", token2str(m->token));
3035 	}
3036 
3037 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
3038 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
3039 		SEQ_OPTS_PRINT("resuid=%u",
3040 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
3041 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
3042 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
3043 		SEQ_OPTS_PRINT("resgid=%u",
3044 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
3045 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
3046 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3047 		SEQ_OPTS_PUTS("errors=remount-ro");
3048 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3049 		SEQ_OPTS_PUTS("errors=continue");
3050 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3051 		SEQ_OPTS_PUTS("errors=panic");
3052 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3053 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3054 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3055 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3056 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3057 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3058 	if (sb->s_flags & SB_I_VERSION)
3059 		SEQ_OPTS_PUTS("i_version");
3060 	if (nodefs || sbi->s_stripe)
3061 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3062 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3063 			(sbi->s_mount_opt ^ def_mount_opt)) {
3064 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3065 			SEQ_OPTS_PUTS("data=journal");
3066 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3067 			SEQ_OPTS_PUTS("data=ordered");
3068 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3069 			SEQ_OPTS_PUTS("data=writeback");
3070 	}
3071 	if (nodefs ||
3072 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3073 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3074 			       sbi->s_inode_readahead_blks);
3075 
3076 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3077 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3078 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3079 	if (nodefs || sbi->s_max_dir_size_kb)
3080 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3081 	if (test_opt(sb, DATA_ERR_ABORT))
3082 		SEQ_OPTS_PUTS("data_err=abort");
3083 
3084 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3085 
3086 	if (sb->s_flags & SB_INLINECRYPT)
3087 		SEQ_OPTS_PUTS("inlinecrypt");
3088 
3089 	if (test_opt(sb, DAX_ALWAYS)) {
3090 		if (IS_EXT2_SB(sb))
3091 			SEQ_OPTS_PUTS("dax");
3092 		else
3093 			SEQ_OPTS_PUTS("dax=always");
3094 	} else if (test_opt2(sb, DAX_NEVER)) {
3095 		SEQ_OPTS_PUTS("dax=never");
3096 	} else if (test_opt2(sb, DAX_INODE)) {
3097 		SEQ_OPTS_PUTS("dax=inode");
3098 	}
3099 	ext4_show_quota_options(seq, sb);
3100 	return 0;
3101 }
3102 
3103 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3104 {
3105 	return _ext4_show_options(seq, root->d_sb, 0);
3106 }
3107 
3108 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3109 {
3110 	struct super_block *sb = seq->private;
3111 	int rc;
3112 
3113 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3114 	rc = _ext4_show_options(seq, sb, 1);
3115 	seq_puts(seq, "\n");
3116 	return rc;
3117 }
3118 
3119 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3120 			    int read_only)
3121 {
3122 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3123 	int err = 0;
3124 
3125 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3126 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3127 			 "forcing read-only mode");
3128 		err = -EROFS;
3129 		goto done;
3130 	}
3131 	if (read_only)
3132 		goto done;
3133 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3134 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3135 			 "running e2fsck is recommended");
3136 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3137 		ext4_msg(sb, KERN_WARNING,
3138 			 "warning: mounting fs with errors, "
3139 			 "running e2fsck is recommended");
3140 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3141 		 le16_to_cpu(es->s_mnt_count) >=
3142 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3143 		ext4_msg(sb, KERN_WARNING,
3144 			 "warning: maximal mount count reached, "
3145 			 "running e2fsck is recommended");
3146 	else if (le32_to_cpu(es->s_checkinterval) &&
3147 		 (ext4_get_tstamp(es, s_lastcheck) +
3148 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3149 		ext4_msg(sb, KERN_WARNING,
3150 			 "warning: checktime reached, "
3151 			 "running e2fsck is recommended");
3152 	if (!sbi->s_journal)
3153 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3154 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3155 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3156 	le16_add_cpu(&es->s_mnt_count, 1);
3157 	ext4_update_tstamp(es, s_mtime);
3158 	if (sbi->s_journal) {
3159 		ext4_set_feature_journal_needs_recovery(sb);
3160 		if (ext4_has_feature_orphan_file(sb))
3161 			ext4_set_feature_orphan_present(sb);
3162 	}
3163 
3164 	err = ext4_commit_super(sb);
3165 done:
3166 	if (test_opt(sb, DEBUG))
3167 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3168 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3169 			sb->s_blocksize,
3170 			sbi->s_groups_count,
3171 			EXT4_BLOCKS_PER_GROUP(sb),
3172 			EXT4_INODES_PER_GROUP(sb),
3173 			sbi->s_mount_opt, sbi->s_mount_opt2);
3174 	return err;
3175 }
3176 
3177 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3178 {
3179 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3180 	struct flex_groups **old_groups, **new_groups;
3181 	int size, i, j;
3182 
3183 	if (!sbi->s_log_groups_per_flex)
3184 		return 0;
3185 
3186 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3187 	if (size <= sbi->s_flex_groups_allocated)
3188 		return 0;
3189 
3190 	new_groups = kvzalloc(roundup_pow_of_two(size *
3191 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3192 	if (!new_groups) {
3193 		ext4_msg(sb, KERN_ERR,
3194 			 "not enough memory for %d flex group pointers", size);
3195 		return -ENOMEM;
3196 	}
3197 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3198 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3199 					 sizeof(struct flex_groups)),
3200 					 GFP_KERNEL);
3201 		if (!new_groups[i]) {
3202 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3203 				kvfree(new_groups[j]);
3204 			kvfree(new_groups);
3205 			ext4_msg(sb, KERN_ERR,
3206 				 "not enough memory for %d flex groups", size);
3207 			return -ENOMEM;
3208 		}
3209 	}
3210 	rcu_read_lock();
3211 	old_groups = rcu_dereference(sbi->s_flex_groups);
3212 	if (old_groups)
3213 		memcpy(new_groups, old_groups,
3214 		       (sbi->s_flex_groups_allocated *
3215 			sizeof(struct flex_groups *)));
3216 	rcu_read_unlock();
3217 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3218 	sbi->s_flex_groups_allocated = size;
3219 	if (old_groups)
3220 		ext4_kvfree_array_rcu(old_groups);
3221 	return 0;
3222 }
3223 
3224 static int ext4_fill_flex_info(struct super_block *sb)
3225 {
3226 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3227 	struct ext4_group_desc *gdp = NULL;
3228 	struct flex_groups *fg;
3229 	ext4_group_t flex_group;
3230 	int i, err;
3231 
3232 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3233 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3234 		sbi->s_log_groups_per_flex = 0;
3235 		return 1;
3236 	}
3237 
3238 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3239 	if (err)
3240 		goto failed;
3241 
3242 	for (i = 0; i < sbi->s_groups_count; i++) {
3243 		gdp = ext4_get_group_desc(sb, i, NULL);
3244 
3245 		flex_group = ext4_flex_group(sbi, i);
3246 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3247 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3248 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3249 			     &fg->free_clusters);
3250 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3251 	}
3252 
3253 	return 1;
3254 failed:
3255 	return 0;
3256 }
3257 
3258 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3259 				   struct ext4_group_desc *gdp)
3260 {
3261 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3262 	__u16 crc = 0;
3263 	__le32 le_group = cpu_to_le32(block_group);
3264 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3265 
3266 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3267 		/* Use new metadata_csum algorithm */
3268 		__u32 csum32;
3269 		__u16 dummy_csum = 0;
3270 
3271 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3272 				     sizeof(le_group));
3273 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3274 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3275 				     sizeof(dummy_csum));
3276 		offset += sizeof(dummy_csum);
3277 		if (offset < sbi->s_desc_size)
3278 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3279 					     sbi->s_desc_size - offset);
3280 
3281 		crc = csum32 & 0xFFFF;
3282 		goto out;
3283 	}
3284 
3285 	/* old crc16 code */
3286 	if (!ext4_has_feature_gdt_csum(sb))
3287 		return 0;
3288 
3289 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3290 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3291 	crc = crc16(crc, (__u8 *)gdp, offset);
3292 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3293 	/* for checksum of struct ext4_group_desc do the rest...*/
3294 	if (ext4_has_feature_64bit(sb) &&
3295 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
3296 		crc = crc16(crc, (__u8 *)gdp + offset,
3297 			    le16_to_cpu(sbi->s_es->s_desc_size) -
3298 				offset);
3299 
3300 out:
3301 	return cpu_to_le16(crc);
3302 }
3303 
3304 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3305 				struct ext4_group_desc *gdp)
3306 {
3307 	if (ext4_has_group_desc_csum(sb) &&
3308 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3309 		return 0;
3310 
3311 	return 1;
3312 }
3313 
3314 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3315 			      struct ext4_group_desc *gdp)
3316 {
3317 	if (!ext4_has_group_desc_csum(sb))
3318 		return;
3319 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3320 }
3321 
3322 /* Called at mount-time, super-block is locked */
3323 static int ext4_check_descriptors(struct super_block *sb,
3324 				  ext4_fsblk_t sb_block,
3325 				  ext4_group_t *first_not_zeroed)
3326 {
3327 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3328 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3329 	ext4_fsblk_t last_block;
3330 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3331 	ext4_fsblk_t block_bitmap;
3332 	ext4_fsblk_t inode_bitmap;
3333 	ext4_fsblk_t inode_table;
3334 	int flexbg_flag = 0;
3335 	ext4_group_t i, grp = sbi->s_groups_count;
3336 
3337 	if (ext4_has_feature_flex_bg(sb))
3338 		flexbg_flag = 1;
3339 
3340 	ext4_debug("Checking group descriptors");
3341 
3342 	for (i = 0; i < sbi->s_groups_count; i++) {
3343 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3344 
3345 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3346 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3347 		else
3348 			last_block = first_block +
3349 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3350 
3351 		if ((grp == sbi->s_groups_count) &&
3352 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3353 			grp = i;
3354 
3355 		block_bitmap = ext4_block_bitmap(sb, gdp);
3356 		if (block_bitmap == sb_block) {
3357 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3358 				 "Block bitmap for group %u overlaps "
3359 				 "superblock", i);
3360 			if (!sb_rdonly(sb))
3361 				return 0;
3362 		}
3363 		if (block_bitmap >= sb_block + 1 &&
3364 		    block_bitmap <= last_bg_block) {
3365 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3366 				 "Block bitmap for group %u overlaps "
3367 				 "block group descriptors", i);
3368 			if (!sb_rdonly(sb))
3369 				return 0;
3370 		}
3371 		if (block_bitmap < first_block || block_bitmap > last_block) {
3372 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3373 			       "Block bitmap for group %u not in group "
3374 			       "(block %llu)!", i, block_bitmap);
3375 			return 0;
3376 		}
3377 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3378 		if (inode_bitmap == sb_block) {
3379 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3380 				 "Inode bitmap for group %u overlaps "
3381 				 "superblock", i);
3382 			if (!sb_rdonly(sb))
3383 				return 0;
3384 		}
3385 		if (inode_bitmap >= sb_block + 1 &&
3386 		    inode_bitmap <= last_bg_block) {
3387 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3388 				 "Inode bitmap for group %u overlaps "
3389 				 "block group descriptors", i);
3390 			if (!sb_rdonly(sb))
3391 				return 0;
3392 		}
3393 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3394 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3395 			       "Inode bitmap for group %u not in group "
3396 			       "(block %llu)!", i, inode_bitmap);
3397 			return 0;
3398 		}
3399 		inode_table = ext4_inode_table(sb, gdp);
3400 		if (inode_table == sb_block) {
3401 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3402 				 "Inode table for group %u overlaps "
3403 				 "superblock", i);
3404 			if (!sb_rdonly(sb))
3405 				return 0;
3406 		}
3407 		if (inode_table >= sb_block + 1 &&
3408 		    inode_table <= last_bg_block) {
3409 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3410 				 "Inode table for group %u overlaps "
3411 				 "block group descriptors", i);
3412 			if (!sb_rdonly(sb))
3413 				return 0;
3414 		}
3415 		if (inode_table < first_block ||
3416 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3417 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3418 			       "Inode table for group %u not in group "
3419 			       "(block %llu)!", i, inode_table);
3420 			return 0;
3421 		}
3422 		ext4_lock_group(sb, i);
3423 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3424 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3425 				 "Checksum for group %u failed (%u!=%u)",
3426 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3427 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3428 			if (!sb_rdonly(sb)) {
3429 				ext4_unlock_group(sb, i);
3430 				return 0;
3431 			}
3432 		}
3433 		ext4_unlock_group(sb, i);
3434 		if (!flexbg_flag)
3435 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3436 	}
3437 	if (NULL != first_not_zeroed)
3438 		*first_not_zeroed = grp;
3439 	return 1;
3440 }
3441 
3442 /*
3443  * Maximal extent format file size.
3444  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3445  * extent format containers, within a sector_t, and within i_blocks
3446  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3447  * so that won't be a limiting factor.
3448  *
3449  * However there is other limiting factor. We do store extents in the form
3450  * of starting block and length, hence the resulting length of the extent
3451  * covering maximum file size must fit into on-disk format containers as
3452  * well. Given that length is always by 1 unit bigger than max unit (because
3453  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3454  *
3455  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3456  */
3457 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3458 {
3459 	loff_t res;
3460 	loff_t upper_limit = MAX_LFS_FILESIZE;
3461 
3462 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3463 
3464 	if (!has_huge_files) {
3465 		upper_limit = (1LL << 32) - 1;
3466 
3467 		/* total blocks in file system block size */
3468 		upper_limit >>= (blkbits - 9);
3469 		upper_limit <<= blkbits;
3470 	}
3471 
3472 	/*
3473 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3474 	 * by one fs block, so ee_len can cover the extent of maximum file
3475 	 * size
3476 	 */
3477 	res = (1LL << 32) - 1;
3478 	res <<= blkbits;
3479 
3480 	/* Sanity check against vm- & vfs- imposed limits */
3481 	if (res > upper_limit)
3482 		res = upper_limit;
3483 
3484 	return res;
3485 }
3486 
3487 /*
3488  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3489  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3490  * We need to be 1 filesystem block less than the 2^48 sector limit.
3491  */
3492 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3493 {
3494 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3495 	int meta_blocks;
3496 	unsigned int ppb = 1 << (bits - 2);
3497 
3498 	/*
3499 	 * This is calculated to be the largest file size for a dense, block
3500 	 * mapped file such that the file's total number of 512-byte sectors,
3501 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3502 	 *
3503 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3504 	 * number of 512-byte sectors of the file.
3505 	 */
3506 	if (!has_huge_files) {
3507 		/*
3508 		 * !has_huge_files or implies that the inode i_block field
3509 		 * represents total file blocks in 2^32 512-byte sectors ==
3510 		 * size of vfs inode i_blocks * 8
3511 		 */
3512 		upper_limit = (1LL << 32) - 1;
3513 
3514 		/* total blocks in file system block size */
3515 		upper_limit >>= (bits - 9);
3516 
3517 	} else {
3518 		/*
3519 		 * We use 48 bit ext4_inode i_blocks
3520 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3521 		 * represent total number of blocks in
3522 		 * file system block size
3523 		 */
3524 		upper_limit = (1LL << 48) - 1;
3525 
3526 	}
3527 
3528 	/* Compute how many blocks we can address by block tree */
3529 	res += ppb;
3530 	res += ppb * ppb;
3531 	res += ((loff_t)ppb) * ppb * ppb;
3532 	/* Compute how many metadata blocks are needed */
3533 	meta_blocks = 1;
3534 	meta_blocks += 1 + ppb;
3535 	meta_blocks += 1 + ppb + ppb * ppb;
3536 	/* Does block tree limit file size? */
3537 	if (res + meta_blocks <= upper_limit)
3538 		goto check_lfs;
3539 
3540 	res = upper_limit;
3541 	/* How many metadata blocks are needed for addressing upper_limit? */
3542 	upper_limit -= EXT4_NDIR_BLOCKS;
3543 	/* indirect blocks */
3544 	meta_blocks = 1;
3545 	upper_limit -= ppb;
3546 	/* double indirect blocks */
3547 	if (upper_limit < ppb * ppb) {
3548 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3549 		res -= meta_blocks;
3550 		goto check_lfs;
3551 	}
3552 	meta_blocks += 1 + ppb;
3553 	upper_limit -= ppb * ppb;
3554 	/* tripple indirect blocks for the rest */
3555 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3556 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3557 	res -= meta_blocks;
3558 check_lfs:
3559 	res <<= bits;
3560 	if (res > MAX_LFS_FILESIZE)
3561 		res = MAX_LFS_FILESIZE;
3562 
3563 	return res;
3564 }
3565 
3566 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3567 				   ext4_fsblk_t logical_sb_block, int nr)
3568 {
3569 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3570 	ext4_group_t bg, first_meta_bg;
3571 	int has_super = 0;
3572 
3573 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3574 
3575 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3576 		return logical_sb_block + nr + 1;
3577 	bg = sbi->s_desc_per_block * nr;
3578 	if (ext4_bg_has_super(sb, bg))
3579 		has_super = 1;
3580 
3581 	/*
3582 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3583 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3584 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3585 	 * compensate.
3586 	 */
3587 	if (sb->s_blocksize == 1024 && nr == 0 &&
3588 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3589 		has_super++;
3590 
3591 	return (has_super + ext4_group_first_block_no(sb, bg));
3592 }
3593 
3594 /**
3595  * ext4_get_stripe_size: Get the stripe size.
3596  * @sbi: In memory super block info
3597  *
3598  * If we have specified it via mount option, then
3599  * use the mount option value. If the value specified at mount time is
3600  * greater than the blocks per group use the super block value.
3601  * If the super block value is greater than blocks per group return 0.
3602  * Allocator needs it be less than blocks per group.
3603  *
3604  */
3605 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3606 {
3607 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3608 	unsigned long stripe_width =
3609 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3610 	int ret;
3611 
3612 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3613 		ret = sbi->s_stripe;
3614 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3615 		ret = stripe_width;
3616 	else if (stride && stride <= sbi->s_blocks_per_group)
3617 		ret = stride;
3618 	else
3619 		ret = 0;
3620 
3621 	/*
3622 	 * If the stripe width is 1, this makes no sense and
3623 	 * we set it to 0 to turn off stripe handling code.
3624 	 */
3625 	if (ret <= 1)
3626 		ret = 0;
3627 
3628 	return ret;
3629 }
3630 
3631 /*
3632  * Check whether this filesystem can be mounted based on
3633  * the features present and the RDONLY/RDWR mount requested.
3634  * Returns 1 if this filesystem can be mounted as requested,
3635  * 0 if it cannot be.
3636  */
3637 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3638 {
3639 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3640 		ext4_msg(sb, KERN_ERR,
3641 			"Couldn't mount because of "
3642 			"unsupported optional features (%x)",
3643 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3644 			~EXT4_FEATURE_INCOMPAT_SUPP));
3645 		return 0;
3646 	}
3647 
3648 #if !IS_ENABLED(CONFIG_UNICODE)
3649 	if (ext4_has_feature_casefold(sb)) {
3650 		ext4_msg(sb, KERN_ERR,
3651 			 "Filesystem with casefold feature cannot be "
3652 			 "mounted without CONFIG_UNICODE");
3653 		return 0;
3654 	}
3655 #endif
3656 
3657 	if (readonly)
3658 		return 1;
3659 
3660 	if (ext4_has_feature_readonly(sb)) {
3661 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3662 		sb->s_flags |= SB_RDONLY;
3663 		return 1;
3664 	}
3665 
3666 	/* Check that feature set is OK for a read-write mount */
3667 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3668 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3669 			 "unsupported optional features (%x)",
3670 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3671 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3672 		return 0;
3673 	}
3674 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3675 		ext4_msg(sb, KERN_ERR,
3676 			 "Can't support bigalloc feature without "
3677 			 "extents feature\n");
3678 		return 0;
3679 	}
3680 
3681 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3682 	if (!readonly && (ext4_has_feature_quota(sb) ||
3683 			  ext4_has_feature_project(sb))) {
3684 		ext4_msg(sb, KERN_ERR,
3685 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3686 		return 0;
3687 	}
3688 #endif  /* CONFIG_QUOTA */
3689 	return 1;
3690 }
3691 
3692 /*
3693  * This function is called once a day if we have errors logged
3694  * on the file system
3695  */
3696 static void print_daily_error_info(struct timer_list *t)
3697 {
3698 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3699 	struct super_block *sb = sbi->s_sb;
3700 	struct ext4_super_block *es = sbi->s_es;
3701 
3702 	if (es->s_error_count)
3703 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3704 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3705 			 le32_to_cpu(es->s_error_count));
3706 	if (es->s_first_error_time) {
3707 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3708 		       sb->s_id,
3709 		       ext4_get_tstamp(es, s_first_error_time),
3710 		       (int) sizeof(es->s_first_error_func),
3711 		       es->s_first_error_func,
3712 		       le32_to_cpu(es->s_first_error_line));
3713 		if (es->s_first_error_ino)
3714 			printk(KERN_CONT ": inode %u",
3715 			       le32_to_cpu(es->s_first_error_ino));
3716 		if (es->s_first_error_block)
3717 			printk(KERN_CONT ": block %llu", (unsigned long long)
3718 			       le64_to_cpu(es->s_first_error_block));
3719 		printk(KERN_CONT "\n");
3720 	}
3721 	if (es->s_last_error_time) {
3722 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3723 		       sb->s_id,
3724 		       ext4_get_tstamp(es, s_last_error_time),
3725 		       (int) sizeof(es->s_last_error_func),
3726 		       es->s_last_error_func,
3727 		       le32_to_cpu(es->s_last_error_line));
3728 		if (es->s_last_error_ino)
3729 			printk(KERN_CONT ": inode %u",
3730 			       le32_to_cpu(es->s_last_error_ino));
3731 		if (es->s_last_error_block)
3732 			printk(KERN_CONT ": block %llu", (unsigned long long)
3733 			       le64_to_cpu(es->s_last_error_block));
3734 		printk(KERN_CONT "\n");
3735 	}
3736 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3737 }
3738 
3739 /* Find next suitable group and run ext4_init_inode_table */
3740 static int ext4_run_li_request(struct ext4_li_request *elr)
3741 {
3742 	struct ext4_group_desc *gdp = NULL;
3743 	struct super_block *sb = elr->lr_super;
3744 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3745 	ext4_group_t group = elr->lr_next_group;
3746 	unsigned int prefetch_ios = 0;
3747 	int ret = 0;
3748 	u64 start_time;
3749 
3750 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3751 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3752 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3753 		if (prefetch_ios)
3754 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3755 					      prefetch_ios);
3756 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3757 					    prefetch_ios);
3758 		if (group >= elr->lr_next_group) {
3759 			ret = 1;
3760 			if (elr->lr_first_not_zeroed != ngroups &&
3761 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3762 				elr->lr_next_group = elr->lr_first_not_zeroed;
3763 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3764 				ret = 0;
3765 			}
3766 		}
3767 		return ret;
3768 	}
3769 
3770 	for (; group < ngroups; group++) {
3771 		gdp = ext4_get_group_desc(sb, group, NULL);
3772 		if (!gdp) {
3773 			ret = 1;
3774 			break;
3775 		}
3776 
3777 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3778 			break;
3779 	}
3780 
3781 	if (group >= ngroups)
3782 		ret = 1;
3783 
3784 	if (!ret) {
3785 		start_time = ktime_get_real_ns();
3786 		ret = ext4_init_inode_table(sb, group,
3787 					    elr->lr_timeout ? 0 : 1);
3788 		trace_ext4_lazy_itable_init(sb, group);
3789 		if (elr->lr_timeout == 0) {
3790 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3791 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3792 		}
3793 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3794 		elr->lr_next_group = group + 1;
3795 	}
3796 	return ret;
3797 }
3798 
3799 /*
3800  * Remove lr_request from the list_request and free the
3801  * request structure. Should be called with li_list_mtx held
3802  */
3803 static void ext4_remove_li_request(struct ext4_li_request *elr)
3804 {
3805 	if (!elr)
3806 		return;
3807 
3808 	list_del(&elr->lr_request);
3809 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3810 	kfree(elr);
3811 }
3812 
3813 static void ext4_unregister_li_request(struct super_block *sb)
3814 {
3815 	mutex_lock(&ext4_li_mtx);
3816 	if (!ext4_li_info) {
3817 		mutex_unlock(&ext4_li_mtx);
3818 		return;
3819 	}
3820 
3821 	mutex_lock(&ext4_li_info->li_list_mtx);
3822 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3823 	mutex_unlock(&ext4_li_info->li_list_mtx);
3824 	mutex_unlock(&ext4_li_mtx);
3825 }
3826 
3827 static struct task_struct *ext4_lazyinit_task;
3828 
3829 /*
3830  * This is the function where ext4lazyinit thread lives. It walks
3831  * through the request list searching for next scheduled filesystem.
3832  * When such a fs is found, run the lazy initialization request
3833  * (ext4_rn_li_request) and keep track of the time spend in this
3834  * function. Based on that time we compute next schedule time of
3835  * the request. When walking through the list is complete, compute
3836  * next waking time and put itself into sleep.
3837  */
3838 static int ext4_lazyinit_thread(void *arg)
3839 {
3840 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3841 	struct list_head *pos, *n;
3842 	struct ext4_li_request *elr;
3843 	unsigned long next_wakeup, cur;
3844 
3845 	BUG_ON(NULL == eli);
3846 
3847 cont_thread:
3848 	while (true) {
3849 		next_wakeup = MAX_JIFFY_OFFSET;
3850 
3851 		mutex_lock(&eli->li_list_mtx);
3852 		if (list_empty(&eli->li_request_list)) {
3853 			mutex_unlock(&eli->li_list_mtx);
3854 			goto exit_thread;
3855 		}
3856 		list_for_each_safe(pos, n, &eli->li_request_list) {
3857 			int err = 0;
3858 			int progress = 0;
3859 			elr = list_entry(pos, struct ext4_li_request,
3860 					 lr_request);
3861 
3862 			if (time_before(jiffies, elr->lr_next_sched)) {
3863 				if (time_before(elr->lr_next_sched, next_wakeup))
3864 					next_wakeup = elr->lr_next_sched;
3865 				continue;
3866 			}
3867 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3868 				if (sb_start_write_trylock(elr->lr_super)) {
3869 					progress = 1;
3870 					/*
3871 					 * We hold sb->s_umount, sb can not
3872 					 * be removed from the list, it is
3873 					 * now safe to drop li_list_mtx
3874 					 */
3875 					mutex_unlock(&eli->li_list_mtx);
3876 					err = ext4_run_li_request(elr);
3877 					sb_end_write(elr->lr_super);
3878 					mutex_lock(&eli->li_list_mtx);
3879 					n = pos->next;
3880 				}
3881 				up_read((&elr->lr_super->s_umount));
3882 			}
3883 			/* error, remove the lazy_init job */
3884 			if (err) {
3885 				ext4_remove_li_request(elr);
3886 				continue;
3887 			}
3888 			if (!progress) {
3889 				elr->lr_next_sched = jiffies +
3890 					(prandom_u32()
3891 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3892 			}
3893 			if (time_before(elr->lr_next_sched, next_wakeup))
3894 				next_wakeup = elr->lr_next_sched;
3895 		}
3896 		mutex_unlock(&eli->li_list_mtx);
3897 
3898 		try_to_freeze();
3899 
3900 		cur = jiffies;
3901 		if ((time_after_eq(cur, next_wakeup)) ||
3902 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3903 			cond_resched();
3904 			continue;
3905 		}
3906 
3907 		schedule_timeout_interruptible(next_wakeup - cur);
3908 
3909 		if (kthread_should_stop()) {
3910 			ext4_clear_request_list();
3911 			goto exit_thread;
3912 		}
3913 	}
3914 
3915 exit_thread:
3916 	/*
3917 	 * It looks like the request list is empty, but we need
3918 	 * to check it under the li_list_mtx lock, to prevent any
3919 	 * additions into it, and of course we should lock ext4_li_mtx
3920 	 * to atomically free the list and ext4_li_info, because at
3921 	 * this point another ext4 filesystem could be registering
3922 	 * new one.
3923 	 */
3924 	mutex_lock(&ext4_li_mtx);
3925 	mutex_lock(&eli->li_list_mtx);
3926 	if (!list_empty(&eli->li_request_list)) {
3927 		mutex_unlock(&eli->li_list_mtx);
3928 		mutex_unlock(&ext4_li_mtx);
3929 		goto cont_thread;
3930 	}
3931 	mutex_unlock(&eli->li_list_mtx);
3932 	kfree(ext4_li_info);
3933 	ext4_li_info = NULL;
3934 	mutex_unlock(&ext4_li_mtx);
3935 
3936 	return 0;
3937 }
3938 
3939 static void ext4_clear_request_list(void)
3940 {
3941 	struct list_head *pos, *n;
3942 	struct ext4_li_request *elr;
3943 
3944 	mutex_lock(&ext4_li_info->li_list_mtx);
3945 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3946 		elr = list_entry(pos, struct ext4_li_request,
3947 				 lr_request);
3948 		ext4_remove_li_request(elr);
3949 	}
3950 	mutex_unlock(&ext4_li_info->li_list_mtx);
3951 }
3952 
3953 static int ext4_run_lazyinit_thread(void)
3954 {
3955 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3956 					 ext4_li_info, "ext4lazyinit");
3957 	if (IS_ERR(ext4_lazyinit_task)) {
3958 		int err = PTR_ERR(ext4_lazyinit_task);
3959 		ext4_clear_request_list();
3960 		kfree(ext4_li_info);
3961 		ext4_li_info = NULL;
3962 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3963 				 "initialization thread\n",
3964 				 err);
3965 		return err;
3966 	}
3967 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3968 	return 0;
3969 }
3970 
3971 /*
3972  * Check whether it make sense to run itable init. thread or not.
3973  * If there is at least one uninitialized inode table, return
3974  * corresponding group number, else the loop goes through all
3975  * groups and return total number of groups.
3976  */
3977 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3978 {
3979 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3980 	struct ext4_group_desc *gdp = NULL;
3981 
3982 	if (!ext4_has_group_desc_csum(sb))
3983 		return ngroups;
3984 
3985 	for (group = 0; group < ngroups; group++) {
3986 		gdp = ext4_get_group_desc(sb, group, NULL);
3987 		if (!gdp)
3988 			continue;
3989 
3990 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3991 			break;
3992 	}
3993 
3994 	return group;
3995 }
3996 
3997 static int ext4_li_info_new(void)
3998 {
3999 	struct ext4_lazy_init *eli = NULL;
4000 
4001 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
4002 	if (!eli)
4003 		return -ENOMEM;
4004 
4005 	INIT_LIST_HEAD(&eli->li_request_list);
4006 	mutex_init(&eli->li_list_mtx);
4007 
4008 	eli->li_state |= EXT4_LAZYINIT_QUIT;
4009 
4010 	ext4_li_info = eli;
4011 
4012 	return 0;
4013 }
4014 
4015 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
4016 					    ext4_group_t start)
4017 {
4018 	struct ext4_li_request *elr;
4019 
4020 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
4021 	if (!elr)
4022 		return NULL;
4023 
4024 	elr->lr_super = sb;
4025 	elr->lr_first_not_zeroed = start;
4026 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
4027 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
4028 		elr->lr_next_group = start;
4029 	} else {
4030 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
4031 	}
4032 
4033 	/*
4034 	 * Randomize first schedule time of the request to
4035 	 * spread the inode table initialization requests
4036 	 * better.
4037 	 */
4038 	elr->lr_next_sched = jiffies + (prandom_u32() %
4039 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
4040 	return elr;
4041 }
4042 
4043 int ext4_register_li_request(struct super_block *sb,
4044 			     ext4_group_t first_not_zeroed)
4045 {
4046 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4047 	struct ext4_li_request *elr = NULL;
4048 	ext4_group_t ngroups = sbi->s_groups_count;
4049 	int ret = 0;
4050 
4051 	mutex_lock(&ext4_li_mtx);
4052 	if (sbi->s_li_request != NULL) {
4053 		/*
4054 		 * Reset timeout so it can be computed again, because
4055 		 * s_li_wait_mult might have changed.
4056 		 */
4057 		sbi->s_li_request->lr_timeout = 0;
4058 		goto out;
4059 	}
4060 
4061 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4062 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
4063 	     !test_opt(sb, INIT_INODE_TABLE)))
4064 		goto out;
4065 
4066 	elr = ext4_li_request_new(sb, first_not_zeroed);
4067 	if (!elr) {
4068 		ret = -ENOMEM;
4069 		goto out;
4070 	}
4071 
4072 	if (NULL == ext4_li_info) {
4073 		ret = ext4_li_info_new();
4074 		if (ret)
4075 			goto out;
4076 	}
4077 
4078 	mutex_lock(&ext4_li_info->li_list_mtx);
4079 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4080 	mutex_unlock(&ext4_li_info->li_list_mtx);
4081 
4082 	sbi->s_li_request = elr;
4083 	/*
4084 	 * set elr to NULL here since it has been inserted to
4085 	 * the request_list and the removal and free of it is
4086 	 * handled by ext4_clear_request_list from now on.
4087 	 */
4088 	elr = NULL;
4089 
4090 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4091 		ret = ext4_run_lazyinit_thread();
4092 		if (ret)
4093 			goto out;
4094 	}
4095 out:
4096 	mutex_unlock(&ext4_li_mtx);
4097 	if (ret)
4098 		kfree(elr);
4099 	return ret;
4100 }
4101 
4102 /*
4103  * We do not need to lock anything since this is called on
4104  * module unload.
4105  */
4106 static void ext4_destroy_lazyinit_thread(void)
4107 {
4108 	/*
4109 	 * If thread exited earlier
4110 	 * there's nothing to be done.
4111 	 */
4112 	if (!ext4_li_info || !ext4_lazyinit_task)
4113 		return;
4114 
4115 	kthread_stop(ext4_lazyinit_task);
4116 }
4117 
4118 static int set_journal_csum_feature_set(struct super_block *sb)
4119 {
4120 	int ret = 1;
4121 	int compat, incompat;
4122 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4123 
4124 	if (ext4_has_metadata_csum(sb)) {
4125 		/* journal checksum v3 */
4126 		compat = 0;
4127 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4128 	} else {
4129 		/* journal checksum v1 */
4130 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4131 		incompat = 0;
4132 	}
4133 
4134 	jbd2_journal_clear_features(sbi->s_journal,
4135 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4136 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4137 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4138 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4139 		ret = jbd2_journal_set_features(sbi->s_journal,
4140 				compat, 0,
4141 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4142 				incompat);
4143 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4144 		ret = jbd2_journal_set_features(sbi->s_journal,
4145 				compat, 0,
4146 				incompat);
4147 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4148 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4149 	} else {
4150 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4151 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4152 	}
4153 
4154 	return ret;
4155 }
4156 
4157 /*
4158  * Note: calculating the overhead so we can be compatible with
4159  * historical BSD practice is quite difficult in the face of
4160  * clusters/bigalloc.  This is because multiple metadata blocks from
4161  * different block group can end up in the same allocation cluster.
4162  * Calculating the exact overhead in the face of clustered allocation
4163  * requires either O(all block bitmaps) in memory or O(number of block
4164  * groups**2) in time.  We will still calculate the superblock for
4165  * older file systems --- and if we come across with a bigalloc file
4166  * system with zero in s_overhead_clusters the estimate will be close to
4167  * correct especially for very large cluster sizes --- but for newer
4168  * file systems, it's better to calculate this figure once at mkfs
4169  * time, and store it in the superblock.  If the superblock value is
4170  * present (even for non-bigalloc file systems), we will use it.
4171  */
4172 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4173 			  char *buf)
4174 {
4175 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4176 	struct ext4_group_desc	*gdp;
4177 	ext4_fsblk_t		first_block, last_block, b;
4178 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4179 	int			s, j, count = 0;
4180 	int			has_super = ext4_bg_has_super(sb, grp);
4181 
4182 	if (!ext4_has_feature_bigalloc(sb))
4183 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4184 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4185 			sbi->s_itb_per_group + 2);
4186 
4187 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4188 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4189 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4190 	for (i = 0; i < ngroups; i++) {
4191 		gdp = ext4_get_group_desc(sb, i, NULL);
4192 		b = ext4_block_bitmap(sb, gdp);
4193 		if (b >= first_block && b <= last_block) {
4194 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4195 			count++;
4196 		}
4197 		b = ext4_inode_bitmap(sb, gdp);
4198 		if (b >= first_block && b <= last_block) {
4199 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4200 			count++;
4201 		}
4202 		b = ext4_inode_table(sb, gdp);
4203 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4204 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4205 				int c = EXT4_B2C(sbi, b - first_block);
4206 				ext4_set_bit(c, buf);
4207 				count++;
4208 			}
4209 		if (i != grp)
4210 			continue;
4211 		s = 0;
4212 		if (ext4_bg_has_super(sb, grp)) {
4213 			ext4_set_bit(s++, buf);
4214 			count++;
4215 		}
4216 		j = ext4_bg_num_gdb(sb, grp);
4217 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4218 			ext4_error(sb, "Invalid number of block group "
4219 				   "descriptor blocks: %d", j);
4220 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4221 		}
4222 		count += j;
4223 		for (; j > 0; j--)
4224 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4225 	}
4226 	if (!count)
4227 		return 0;
4228 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4229 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4230 }
4231 
4232 /*
4233  * Compute the overhead and stash it in sbi->s_overhead
4234  */
4235 int ext4_calculate_overhead(struct super_block *sb)
4236 {
4237 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4238 	struct ext4_super_block *es = sbi->s_es;
4239 	struct inode *j_inode;
4240 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4241 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4242 	ext4_fsblk_t overhead = 0;
4243 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4244 
4245 	if (!buf)
4246 		return -ENOMEM;
4247 
4248 	/*
4249 	 * Compute the overhead (FS structures).  This is constant
4250 	 * for a given filesystem unless the number of block groups
4251 	 * changes so we cache the previous value until it does.
4252 	 */
4253 
4254 	/*
4255 	 * All of the blocks before first_data_block are overhead
4256 	 */
4257 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4258 
4259 	/*
4260 	 * Add the overhead found in each block group
4261 	 */
4262 	for (i = 0; i < ngroups; i++) {
4263 		int blks;
4264 
4265 		blks = count_overhead(sb, i, buf);
4266 		overhead += blks;
4267 		if (blks)
4268 			memset(buf, 0, PAGE_SIZE);
4269 		cond_resched();
4270 	}
4271 
4272 	/*
4273 	 * Add the internal journal blocks whether the journal has been
4274 	 * loaded or not
4275 	 */
4276 	if (sbi->s_journal && !sbi->s_journal_bdev)
4277 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4278 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4279 		/* j_inum for internal journal is non-zero */
4280 		j_inode = ext4_get_journal_inode(sb, j_inum);
4281 		if (j_inode) {
4282 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4283 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4284 			iput(j_inode);
4285 		} else {
4286 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4287 		}
4288 	}
4289 	sbi->s_overhead = overhead;
4290 	smp_wmb();
4291 	free_page((unsigned long) buf);
4292 	return 0;
4293 }
4294 
4295 static void ext4_set_resv_clusters(struct super_block *sb)
4296 {
4297 	ext4_fsblk_t resv_clusters;
4298 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4299 
4300 	/*
4301 	 * There's no need to reserve anything when we aren't using extents.
4302 	 * The space estimates are exact, there are no unwritten extents,
4303 	 * hole punching doesn't need new metadata... This is needed especially
4304 	 * to keep ext2/3 backward compatibility.
4305 	 */
4306 	if (!ext4_has_feature_extents(sb))
4307 		return;
4308 	/*
4309 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4310 	 * This should cover the situations where we can not afford to run
4311 	 * out of space like for example punch hole, or converting
4312 	 * unwritten extents in delalloc path. In most cases such
4313 	 * allocation would require 1, or 2 blocks, higher numbers are
4314 	 * very rare.
4315 	 */
4316 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4317 			 sbi->s_cluster_bits);
4318 
4319 	do_div(resv_clusters, 50);
4320 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4321 
4322 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4323 }
4324 
4325 static const char *ext4_quota_mode(struct super_block *sb)
4326 {
4327 #ifdef CONFIG_QUOTA
4328 	if (!ext4_quota_capable(sb))
4329 		return "none";
4330 
4331 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4332 		return "journalled";
4333 	else
4334 		return "writeback";
4335 #else
4336 	return "disabled";
4337 #endif
4338 }
4339 
4340 static void ext4_setup_csum_trigger(struct super_block *sb,
4341 				    enum ext4_journal_trigger_type type,
4342 				    void (*trigger)(
4343 					struct jbd2_buffer_trigger_type *type,
4344 					struct buffer_head *bh,
4345 					void *mapped_data,
4346 					size_t size))
4347 {
4348 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4349 
4350 	sbi->s_journal_triggers[type].sb = sb;
4351 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4352 }
4353 
4354 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4355 {
4356 	if (!sbi)
4357 		return;
4358 
4359 	kfree(sbi->s_blockgroup_lock);
4360 	fs_put_dax(sbi->s_daxdev);
4361 	kfree(sbi);
4362 }
4363 
4364 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4365 {
4366 	struct ext4_sb_info *sbi;
4367 
4368 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4369 	if (!sbi)
4370 		return NULL;
4371 
4372 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off);
4373 
4374 	sbi->s_blockgroup_lock =
4375 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4376 
4377 	if (!sbi->s_blockgroup_lock)
4378 		goto err_out;
4379 
4380 	sb->s_fs_info = sbi;
4381 	sbi->s_sb = sb;
4382 	return sbi;
4383 err_out:
4384 	fs_put_dax(sbi->s_daxdev);
4385 	kfree(sbi);
4386 	return NULL;
4387 }
4388 
4389 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
4390 {
4391 	struct buffer_head *bh, **group_desc;
4392 	struct ext4_super_block *es = NULL;
4393 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4394 	struct flex_groups **flex_groups;
4395 	ext4_fsblk_t block;
4396 	ext4_fsblk_t logical_sb_block;
4397 	unsigned long offset = 0;
4398 	unsigned long def_mount_opts;
4399 	struct inode *root;
4400 	int ret = -ENOMEM;
4401 	int blocksize, clustersize;
4402 	unsigned int db_count;
4403 	unsigned int i;
4404 	int needs_recovery, has_huge_files;
4405 	__u64 blocks_count;
4406 	int err = 0;
4407 	ext4_group_t first_not_zeroed;
4408 	struct ext4_fs_context *ctx = fc->fs_private;
4409 	int silent = fc->sb_flags & SB_SILENT;
4410 
4411 	/* Set defaults for the variables that will be set during parsing */
4412 	ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4413 
4414 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4415 	sbi->s_sectors_written_start =
4416 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4417 
4418 	/* -EINVAL is default */
4419 	ret = -EINVAL;
4420 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4421 	if (!blocksize) {
4422 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4423 		goto out_fail;
4424 	}
4425 
4426 	/*
4427 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4428 	 * block sizes.  We need to calculate the offset from buffer start.
4429 	 */
4430 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4431 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4432 		offset = do_div(logical_sb_block, blocksize);
4433 	} else {
4434 		logical_sb_block = sbi->s_sb_block;
4435 	}
4436 
4437 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4438 	if (IS_ERR(bh)) {
4439 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4440 		ret = PTR_ERR(bh);
4441 		goto out_fail;
4442 	}
4443 	/*
4444 	 * Note: s_es must be initialized as soon as possible because
4445 	 *       some ext4 macro-instructions depend on its value
4446 	 */
4447 	es = (struct ext4_super_block *) (bh->b_data + offset);
4448 	sbi->s_es = es;
4449 	sb->s_magic = le16_to_cpu(es->s_magic);
4450 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4451 		goto cantfind_ext4;
4452 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4453 
4454 	/* Warn if metadata_csum and gdt_csum are both set. */
4455 	if (ext4_has_feature_metadata_csum(sb) &&
4456 	    ext4_has_feature_gdt_csum(sb))
4457 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4458 			     "redundant flags; please run fsck.");
4459 
4460 	/* Check for a known checksum algorithm */
4461 	if (!ext4_verify_csum_type(sb, es)) {
4462 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4463 			 "unknown checksum algorithm.");
4464 		silent = 1;
4465 		goto cantfind_ext4;
4466 	}
4467 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4468 				ext4_orphan_file_block_trigger);
4469 
4470 	/* Load the checksum driver */
4471 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4472 	if (IS_ERR(sbi->s_chksum_driver)) {
4473 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4474 		ret = PTR_ERR(sbi->s_chksum_driver);
4475 		sbi->s_chksum_driver = NULL;
4476 		goto failed_mount;
4477 	}
4478 
4479 	/* Check superblock checksum */
4480 	if (!ext4_superblock_csum_verify(sb, es)) {
4481 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4482 			 "invalid superblock checksum.  Run e2fsck?");
4483 		silent = 1;
4484 		ret = -EFSBADCRC;
4485 		goto cantfind_ext4;
4486 	}
4487 
4488 	/* Precompute checksum seed for all metadata */
4489 	if (ext4_has_feature_csum_seed(sb))
4490 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4491 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4492 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4493 					       sizeof(es->s_uuid));
4494 
4495 	/* Set defaults before we parse the mount options */
4496 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4497 	set_opt(sb, INIT_INODE_TABLE);
4498 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4499 		set_opt(sb, DEBUG);
4500 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4501 		set_opt(sb, GRPID);
4502 	if (def_mount_opts & EXT4_DEFM_UID16)
4503 		set_opt(sb, NO_UID32);
4504 	/* xattr user namespace & acls are now defaulted on */
4505 	set_opt(sb, XATTR_USER);
4506 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4507 	set_opt(sb, POSIX_ACL);
4508 #endif
4509 	if (ext4_has_feature_fast_commit(sb))
4510 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4511 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4512 	if (ext4_has_metadata_csum(sb))
4513 		set_opt(sb, JOURNAL_CHECKSUM);
4514 
4515 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4516 		set_opt(sb, JOURNAL_DATA);
4517 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4518 		set_opt(sb, ORDERED_DATA);
4519 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4520 		set_opt(sb, WRITEBACK_DATA);
4521 
4522 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4523 		set_opt(sb, ERRORS_PANIC);
4524 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4525 		set_opt(sb, ERRORS_CONT);
4526 	else
4527 		set_opt(sb, ERRORS_RO);
4528 	/* block_validity enabled by default; disable with noblock_validity */
4529 	set_opt(sb, BLOCK_VALIDITY);
4530 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4531 		set_opt(sb, DISCARD);
4532 
4533 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4534 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4535 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4536 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4537 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4538 
4539 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4540 		set_opt(sb, BARRIER);
4541 
4542 	/*
4543 	 * enable delayed allocation by default
4544 	 * Use -o nodelalloc to turn it off
4545 	 */
4546 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4547 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4548 		set_opt(sb, DELALLOC);
4549 
4550 	/*
4551 	 * set default s_li_wait_mult for lazyinit, for the case there is
4552 	 * no mount option specified.
4553 	 */
4554 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4555 
4556 	if (le32_to_cpu(es->s_log_block_size) >
4557 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4558 		ext4_msg(sb, KERN_ERR,
4559 			 "Invalid log block size: %u",
4560 			 le32_to_cpu(es->s_log_block_size));
4561 		goto failed_mount;
4562 	}
4563 	if (le32_to_cpu(es->s_log_cluster_size) >
4564 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4565 		ext4_msg(sb, KERN_ERR,
4566 			 "Invalid log cluster size: %u",
4567 			 le32_to_cpu(es->s_log_cluster_size));
4568 		goto failed_mount;
4569 	}
4570 
4571 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4572 
4573 	if (blocksize == PAGE_SIZE)
4574 		set_opt(sb, DIOREAD_NOLOCK);
4575 
4576 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4577 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4578 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4579 	} else {
4580 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4581 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4582 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4583 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4584 				 sbi->s_first_ino);
4585 			goto failed_mount;
4586 		}
4587 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4588 		    (!is_power_of_2(sbi->s_inode_size)) ||
4589 		    (sbi->s_inode_size > blocksize)) {
4590 			ext4_msg(sb, KERN_ERR,
4591 			       "unsupported inode size: %d",
4592 			       sbi->s_inode_size);
4593 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4594 			goto failed_mount;
4595 		}
4596 		/*
4597 		 * i_atime_extra is the last extra field available for
4598 		 * [acm]times in struct ext4_inode. Checking for that
4599 		 * field should suffice to ensure we have extra space
4600 		 * for all three.
4601 		 */
4602 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4603 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4604 			sb->s_time_gran = 1;
4605 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4606 		} else {
4607 			sb->s_time_gran = NSEC_PER_SEC;
4608 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4609 		}
4610 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4611 	}
4612 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4613 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4614 			EXT4_GOOD_OLD_INODE_SIZE;
4615 		if (ext4_has_feature_extra_isize(sb)) {
4616 			unsigned v, max = (sbi->s_inode_size -
4617 					   EXT4_GOOD_OLD_INODE_SIZE);
4618 
4619 			v = le16_to_cpu(es->s_want_extra_isize);
4620 			if (v > max) {
4621 				ext4_msg(sb, KERN_ERR,
4622 					 "bad s_want_extra_isize: %d", v);
4623 				goto failed_mount;
4624 			}
4625 			if (sbi->s_want_extra_isize < v)
4626 				sbi->s_want_extra_isize = v;
4627 
4628 			v = le16_to_cpu(es->s_min_extra_isize);
4629 			if (v > max) {
4630 				ext4_msg(sb, KERN_ERR,
4631 					 "bad s_min_extra_isize: %d", v);
4632 				goto failed_mount;
4633 			}
4634 			if (sbi->s_want_extra_isize < v)
4635 				sbi->s_want_extra_isize = v;
4636 		}
4637 	}
4638 
4639 	err = parse_apply_sb_mount_options(sb, ctx);
4640 	if (err < 0)
4641 		goto failed_mount;
4642 
4643 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4644 
4645 	err = ext4_check_opt_consistency(fc, sb);
4646 	if (err < 0)
4647 		goto failed_mount;
4648 
4649 	err = ext4_apply_options(fc, sb);
4650 	if (err < 0)
4651 		goto failed_mount;
4652 
4653 #if IS_ENABLED(CONFIG_UNICODE)
4654 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4655 		const struct ext4_sb_encodings *encoding_info;
4656 		struct unicode_map *encoding;
4657 		__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4658 
4659 		encoding_info = ext4_sb_read_encoding(es);
4660 		if (!encoding_info) {
4661 			ext4_msg(sb, KERN_ERR,
4662 				 "Encoding requested by superblock is unknown");
4663 			goto failed_mount;
4664 		}
4665 
4666 		encoding = utf8_load(encoding_info->version);
4667 		if (IS_ERR(encoding)) {
4668 			ext4_msg(sb, KERN_ERR,
4669 				 "can't mount with superblock charset: %s-%u.%u.%u "
4670 				 "not supported by the kernel. flags: 0x%x.",
4671 				 encoding_info->name,
4672 				 unicode_major(encoding_info->version),
4673 				 unicode_minor(encoding_info->version),
4674 				 unicode_rev(encoding_info->version),
4675 				 encoding_flags);
4676 			goto failed_mount;
4677 		}
4678 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4679 			 "%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4680 			 unicode_major(encoding_info->version),
4681 			 unicode_minor(encoding_info->version),
4682 			 unicode_rev(encoding_info->version),
4683 			 encoding_flags);
4684 
4685 		sb->s_encoding = encoding;
4686 		sb->s_encoding_flags = encoding_flags;
4687 	}
4688 #endif
4689 
4690 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4691 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4692 		/* can't mount with both data=journal and dioread_nolock. */
4693 		clear_opt(sb, DIOREAD_NOLOCK);
4694 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4695 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4696 			ext4_msg(sb, KERN_ERR, "can't mount with "
4697 				 "both data=journal and delalloc");
4698 			goto failed_mount;
4699 		}
4700 		if (test_opt(sb, DAX_ALWAYS)) {
4701 			ext4_msg(sb, KERN_ERR, "can't mount with "
4702 				 "both data=journal and dax");
4703 			goto failed_mount;
4704 		}
4705 		if (ext4_has_feature_encrypt(sb)) {
4706 			ext4_msg(sb, KERN_WARNING,
4707 				 "encrypted files will use data=ordered "
4708 				 "instead of data journaling mode");
4709 		}
4710 		if (test_opt(sb, DELALLOC))
4711 			clear_opt(sb, DELALLOC);
4712 	} else {
4713 		sb->s_iflags |= SB_I_CGROUPWB;
4714 	}
4715 
4716 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4717 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4718 
4719 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4720 	    (ext4_has_compat_features(sb) ||
4721 	     ext4_has_ro_compat_features(sb) ||
4722 	     ext4_has_incompat_features(sb)))
4723 		ext4_msg(sb, KERN_WARNING,
4724 		       "feature flags set on rev 0 fs, "
4725 		       "running e2fsck is recommended");
4726 
4727 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4728 		set_opt2(sb, HURD_COMPAT);
4729 		if (ext4_has_feature_64bit(sb)) {
4730 			ext4_msg(sb, KERN_ERR,
4731 				 "The Hurd can't support 64-bit file systems");
4732 			goto failed_mount;
4733 		}
4734 
4735 		/*
4736 		 * ea_inode feature uses l_i_version field which is not
4737 		 * available in HURD_COMPAT mode.
4738 		 */
4739 		if (ext4_has_feature_ea_inode(sb)) {
4740 			ext4_msg(sb, KERN_ERR,
4741 				 "ea_inode feature is not supported for Hurd");
4742 			goto failed_mount;
4743 		}
4744 	}
4745 
4746 	if (IS_EXT2_SB(sb)) {
4747 		if (ext2_feature_set_ok(sb))
4748 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4749 				 "using the ext4 subsystem");
4750 		else {
4751 			/*
4752 			 * If we're probing be silent, if this looks like
4753 			 * it's actually an ext[34] filesystem.
4754 			 */
4755 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4756 				goto failed_mount;
4757 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4758 				 "to feature incompatibilities");
4759 			goto failed_mount;
4760 		}
4761 	}
4762 
4763 	if (IS_EXT3_SB(sb)) {
4764 		if (ext3_feature_set_ok(sb))
4765 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4766 				 "using the ext4 subsystem");
4767 		else {
4768 			/*
4769 			 * If we're probing be silent, if this looks like
4770 			 * it's actually an ext4 filesystem.
4771 			 */
4772 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4773 				goto failed_mount;
4774 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4775 				 "to feature incompatibilities");
4776 			goto failed_mount;
4777 		}
4778 	}
4779 
4780 	/*
4781 	 * Check feature flags regardless of the revision level, since we
4782 	 * previously didn't change the revision level when setting the flags,
4783 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4784 	 */
4785 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4786 		goto failed_mount;
4787 
4788 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4789 		ext4_msg(sb, KERN_ERR,
4790 			 "Number of reserved GDT blocks insanely large: %d",
4791 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4792 		goto failed_mount;
4793 	}
4794 
4795 	if (sbi->s_daxdev) {
4796 		if (blocksize == PAGE_SIZE)
4797 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4798 		else
4799 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4800 	}
4801 
4802 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4803 		if (ext4_has_feature_inline_data(sb)) {
4804 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4805 					" that may contain inline data");
4806 			goto failed_mount;
4807 		}
4808 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4809 			ext4_msg(sb, KERN_ERR,
4810 				"DAX unsupported by block device.");
4811 			goto failed_mount;
4812 		}
4813 	}
4814 
4815 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4816 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4817 			 es->s_encryption_level);
4818 		goto failed_mount;
4819 	}
4820 
4821 	if (sb->s_blocksize != blocksize) {
4822 		/*
4823 		 * bh must be released before kill_bdev(), otherwise
4824 		 * it won't be freed and its page also. kill_bdev()
4825 		 * is called by sb_set_blocksize().
4826 		 */
4827 		brelse(bh);
4828 		/* Validate the filesystem blocksize */
4829 		if (!sb_set_blocksize(sb, blocksize)) {
4830 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4831 					blocksize);
4832 			bh = NULL;
4833 			goto failed_mount;
4834 		}
4835 
4836 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4837 		offset = do_div(logical_sb_block, blocksize);
4838 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4839 		if (IS_ERR(bh)) {
4840 			ext4_msg(sb, KERN_ERR,
4841 			       "Can't read superblock on 2nd try");
4842 			ret = PTR_ERR(bh);
4843 			bh = NULL;
4844 			goto failed_mount;
4845 		}
4846 		es = (struct ext4_super_block *)(bh->b_data + offset);
4847 		sbi->s_es = es;
4848 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4849 			ext4_msg(sb, KERN_ERR,
4850 			       "Magic mismatch, very weird!");
4851 			goto failed_mount;
4852 		}
4853 	}
4854 
4855 	has_huge_files = ext4_has_feature_huge_file(sb);
4856 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4857 						      has_huge_files);
4858 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4859 
4860 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4861 	if (ext4_has_feature_64bit(sb)) {
4862 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4863 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4864 		    !is_power_of_2(sbi->s_desc_size)) {
4865 			ext4_msg(sb, KERN_ERR,
4866 			       "unsupported descriptor size %lu",
4867 			       sbi->s_desc_size);
4868 			goto failed_mount;
4869 		}
4870 	} else
4871 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4872 
4873 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4874 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4875 
4876 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4877 	if (sbi->s_inodes_per_block == 0)
4878 		goto cantfind_ext4;
4879 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4880 	    sbi->s_inodes_per_group > blocksize * 8) {
4881 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4882 			 sbi->s_inodes_per_group);
4883 		goto failed_mount;
4884 	}
4885 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4886 					sbi->s_inodes_per_block;
4887 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4888 	sbi->s_sbh = bh;
4889 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4890 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4891 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4892 
4893 	for (i = 0; i < 4; i++)
4894 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4895 	sbi->s_def_hash_version = es->s_def_hash_version;
4896 	if (ext4_has_feature_dir_index(sb)) {
4897 		i = le32_to_cpu(es->s_flags);
4898 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4899 			sbi->s_hash_unsigned = 3;
4900 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4901 #ifdef __CHAR_UNSIGNED__
4902 			if (!sb_rdonly(sb))
4903 				es->s_flags |=
4904 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4905 			sbi->s_hash_unsigned = 3;
4906 #else
4907 			if (!sb_rdonly(sb))
4908 				es->s_flags |=
4909 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4910 #endif
4911 		}
4912 	}
4913 
4914 	/* Handle clustersize */
4915 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4916 	if (ext4_has_feature_bigalloc(sb)) {
4917 		if (clustersize < blocksize) {
4918 			ext4_msg(sb, KERN_ERR,
4919 				 "cluster size (%d) smaller than "
4920 				 "block size (%d)", clustersize, blocksize);
4921 			goto failed_mount;
4922 		}
4923 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4924 			le32_to_cpu(es->s_log_block_size);
4925 		sbi->s_clusters_per_group =
4926 			le32_to_cpu(es->s_clusters_per_group);
4927 		if (sbi->s_clusters_per_group > blocksize * 8) {
4928 			ext4_msg(sb, KERN_ERR,
4929 				 "#clusters per group too big: %lu",
4930 				 sbi->s_clusters_per_group);
4931 			goto failed_mount;
4932 		}
4933 		if (sbi->s_blocks_per_group !=
4934 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4935 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4936 				 "clusters per group (%lu) inconsistent",
4937 				 sbi->s_blocks_per_group,
4938 				 sbi->s_clusters_per_group);
4939 			goto failed_mount;
4940 		}
4941 	} else {
4942 		if (clustersize != blocksize) {
4943 			ext4_msg(sb, KERN_ERR,
4944 				 "fragment/cluster size (%d) != "
4945 				 "block size (%d)", clustersize, blocksize);
4946 			goto failed_mount;
4947 		}
4948 		if (sbi->s_blocks_per_group > blocksize * 8) {
4949 			ext4_msg(sb, KERN_ERR,
4950 				 "#blocks per group too big: %lu",
4951 				 sbi->s_blocks_per_group);
4952 			goto failed_mount;
4953 		}
4954 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4955 		sbi->s_cluster_bits = 0;
4956 	}
4957 	sbi->s_cluster_ratio = clustersize / blocksize;
4958 
4959 	/* Do we have standard group size of clustersize * 8 blocks ? */
4960 	if (sbi->s_blocks_per_group == clustersize << 3)
4961 		set_opt2(sb, STD_GROUP_SIZE);
4962 
4963 	/*
4964 	 * Test whether we have more sectors than will fit in sector_t,
4965 	 * and whether the max offset is addressable by the page cache.
4966 	 */
4967 	err = generic_check_addressable(sb->s_blocksize_bits,
4968 					ext4_blocks_count(es));
4969 	if (err) {
4970 		ext4_msg(sb, KERN_ERR, "filesystem"
4971 			 " too large to mount safely on this system");
4972 		goto failed_mount;
4973 	}
4974 
4975 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4976 		goto cantfind_ext4;
4977 
4978 	/* check blocks count against device size */
4979 	blocks_count = sb_bdev_nr_blocks(sb);
4980 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4981 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4982 		       "exceeds size of device (%llu blocks)",
4983 		       ext4_blocks_count(es), blocks_count);
4984 		goto failed_mount;
4985 	}
4986 
4987 	/*
4988 	 * It makes no sense for the first data block to be beyond the end
4989 	 * of the filesystem.
4990 	 */
4991 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4992 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4993 			 "block %u is beyond end of filesystem (%llu)",
4994 			 le32_to_cpu(es->s_first_data_block),
4995 			 ext4_blocks_count(es));
4996 		goto failed_mount;
4997 	}
4998 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4999 	    (sbi->s_cluster_ratio == 1)) {
5000 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
5001 			 "block is 0 with a 1k block and cluster size");
5002 		goto failed_mount;
5003 	}
5004 
5005 	blocks_count = (ext4_blocks_count(es) -
5006 			le32_to_cpu(es->s_first_data_block) +
5007 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
5008 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
5009 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
5010 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
5011 		       "(block count %llu, first data block %u, "
5012 		       "blocks per group %lu)", blocks_count,
5013 		       ext4_blocks_count(es),
5014 		       le32_to_cpu(es->s_first_data_block),
5015 		       EXT4_BLOCKS_PER_GROUP(sb));
5016 		goto failed_mount;
5017 	}
5018 	sbi->s_groups_count = blocks_count;
5019 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
5020 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
5021 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
5022 	    le32_to_cpu(es->s_inodes_count)) {
5023 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
5024 			 le32_to_cpu(es->s_inodes_count),
5025 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
5026 		ret = -EINVAL;
5027 		goto failed_mount;
5028 	}
5029 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
5030 		   EXT4_DESC_PER_BLOCK(sb);
5031 	if (ext4_has_feature_meta_bg(sb)) {
5032 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
5033 			ext4_msg(sb, KERN_WARNING,
5034 				 "first meta block group too large: %u "
5035 				 "(group descriptor block count %u)",
5036 				 le32_to_cpu(es->s_first_meta_bg), db_count);
5037 			goto failed_mount;
5038 		}
5039 	}
5040 	rcu_assign_pointer(sbi->s_group_desc,
5041 			   kvmalloc_array(db_count,
5042 					  sizeof(struct buffer_head *),
5043 					  GFP_KERNEL));
5044 	if (sbi->s_group_desc == NULL) {
5045 		ext4_msg(sb, KERN_ERR, "not enough memory");
5046 		ret = -ENOMEM;
5047 		goto failed_mount;
5048 	}
5049 
5050 	bgl_lock_init(sbi->s_blockgroup_lock);
5051 
5052 	/* Pre-read the descriptors into the buffer cache */
5053 	for (i = 0; i < db_count; i++) {
5054 		block = descriptor_loc(sb, logical_sb_block, i);
5055 		ext4_sb_breadahead_unmovable(sb, block);
5056 	}
5057 
5058 	for (i = 0; i < db_count; i++) {
5059 		struct buffer_head *bh;
5060 
5061 		block = descriptor_loc(sb, logical_sb_block, i);
5062 		bh = ext4_sb_bread_unmovable(sb, block);
5063 		if (IS_ERR(bh)) {
5064 			ext4_msg(sb, KERN_ERR,
5065 			       "can't read group descriptor %d", i);
5066 			db_count = i;
5067 			ret = PTR_ERR(bh);
5068 			goto failed_mount2;
5069 		}
5070 		rcu_read_lock();
5071 		rcu_dereference(sbi->s_group_desc)[i] = bh;
5072 		rcu_read_unlock();
5073 	}
5074 	sbi->s_gdb_count = db_count;
5075 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
5076 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
5077 		ret = -EFSCORRUPTED;
5078 		goto failed_mount2;
5079 	}
5080 
5081 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5082 	spin_lock_init(&sbi->s_error_lock);
5083 	INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5084 
5085 	/* Register extent status tree shrinker */
5086 	if (ext4_es_register_shrinker(sbi))
5087 		goto failed_mount3;
5088 
5089 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5090 	sbi->s_extent_max_zeroout_kb = 32;
5091 
5092 	/*
5093 	 * set up enough so that it can read an inode
5094 	 */
5095 	sb->s_op = &ext4_sops;
5096 	sb->s_export_op = &ext4_export_ops;
5097 	sb->s_xattr = ext4_xattr_handlers;
5098 #ifdef CONFIG_FS_ENCRYPTION
5099 	sb->s_cop = &ext4_cryptops;
5100 #endif
5101 #ifdef CONFIG_FS_VERITY
5102 	sb->s_vop = &ext4_verityops;
5103 #endif
5104 #ifdef CONFIG_QUOTA
5105 	sb->dq_op = &ext4_quota_operations;
5106 	if (ext4_has_feature_quota(sb))
5107 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5108 	else
5109 		sb->s_qcop = &ext4_qctl_operations;
5110 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5111 #endif
5112 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5113 
5114 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5115 	mutex_init(&sbi->s_orphan_lock);
5116 
5117 	/* Initialize fast commit stuff */
5118 	atomic_set(&sbi->s_fc_subtid, 0);
5119 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
5120 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
5121 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
5122 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
5123 	sbi->s_fc_bytes = 0;
5124 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
5125 	sbi->s_fc_ineligible_tid = 0;
5126 	spin_lock_init(&sbi->s_fc_lock);
5127 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
5128 	sbi->s_fc_replay_state.fc_regions = NULL;
5129 	sbi->s_fc_replay_state.fc_regions_size = 0;
5130 	sbi->s_fc_replay_state.fc_regions_used = 0;
5131 	sbi->s_fc_replay_state.fc_regions_valid = 0;
5132 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
5133 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
5134 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
5135 
5136 	sb->s_root = NULL;
5137 
5138 	needs_recovery = (es->s_last_orphan != 0 ||
5139 			  ext4_has_feature_orphan_present(sb) ||
5140 			  ext4_has_feature_journal_needs_recovery(sb));
5141 
5142 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5143 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5144 			goto failed_mount3a;
5145 
5146 	/*
5147 	 * The first inode we look at is the journal inode.  Don't try
5148 	 * root first: it may be modified in the journal!
5149 	 */
5150 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5151 		err = ext4_load_journal(sb, es, ctx->journal_devnum);
5152 		if (err)
5153 			goto failed_mount3a;
5154 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5155 		   ext4_has_feature_journal_needs_recovery(sb)) {
5156 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5157 		       "suppressed and not mounted read-only");
5158 		goto failed_mount_wq;
5159 	} else {
5160 		/* Nojournal mode, all journal mount options are illegal */
5161 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5162 			ext4_msg(sb, KERN_ERR, "can't mount with "
5163 				 "journal_checksum, fs mounted w/o journal");
5164 			goto failed_mount_wq;
5165 		}
5166 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5167 			ext4_msg(sb, KERN_ERR, "can't mount with "
5168 				 "journal_async_commit, fs mounted w/o journal");
5169 			goto failed_mount_wq;
5170 		}
5171 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5172 			ext4_msg(sb, KERN_ERR, "can't mount with "
5173 				 "commit=%lu, fs mounted w/o journal",
5174 				 sbi->s_commit_interval / HZ);
5175 			goto failed_mount_wq;
5176 		}
5177 		if (EXT4_MOUNT_DATA_FLAGS &
5178 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5179 			ext4_msg(sb, KERN_ERR, "can't mount with "
5180 				 "data=, fs mounted w/o journal");
5181 			goto failed_mount_wq;
5182 		}
5183 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5184 		clear_opt(sb, JOURNAL_CHECKSUM);
5185 		clear_opt(sb, DATA_FLAGS);
5186 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5187 		sbi->s_journal = NULL;
5188 		needs_recovery = 0;
5189 		goto no_journal;
5190 	}
5191 
5192 	if (ext4_has_feature_64bit(sb) &&
5193 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5194 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
5195 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
5196 		goto failed_mount_wq;
5197 	}
5198 
5199 	if (!set_journal_csum_feature_set(sb)) {
5200 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
5201 			 "feature set");
5202 		goto failed_mount_wq;
5203 	}
5204 
5205 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
5206 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5207 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
5208 		ext4_msg(sb, KERN_ERR,
5209 			"Failed to set fast commit journal feature");
5210 		goto failed_mount_wq;
5211 	}
5212 
5213 	/* We have now updated the journal if required, so we can
5214 	 * validate the data journaling mode. */
5215 	switch (test_opt(sb, DATA_FLAGS)) {
5216 	case 0:
5217 		/* No mode set, assume a default based on the journal
5218 		 * capabilities: ORDERED_DATA if the journal can
5219 		 * cope, else JOURNAL_DATA
5220 		 */
5221 		if (jbd2_journal_check_available_features
5222 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5223 			set_opt(sb, ORDERED_DATA);
5224 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
5225 		} else {
5226 			set_opt(sb, JOURNAL_DATA);
5227 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
5228 		}
5229 		break;
5230 
5231 	case EXT4_MOUNT_ORDERED_DATA:
5232 	case EXT4_MOUNT_WRITEBACK_DATA:
5233 		if (!jbd2_journal_check_available_features
5234 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5235 			ext4_msg(sb, KERN_ERR, "Journal does not support "
5236 			       "requested data journaling mode");
5237 			goto failed_mount_wq;
5238 		}
5239 		break;
5240 	default:
5241 		break;
5242 	}
5243 
5244 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5245 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5246 		ext4_msg(sb, KERN_ERR, "can't mount with "
5247 			"journal_async_commit in data=ordered mode");
5248 		goto failed_mount_wq;
5249 	}
5250 
5251 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5252 
5253 	sbi->s_journal->j_submit_inode_data_buffers =
5254 		ext4_journal_submit_inode_data_buffers;
5255 	sbi->s_journal->j_finish_inode_data_buffers =
5256 		ext4_journal_finish_inode_data_buffers;
5257 
5258 no_journal:
5259 	if (!test_opt(sb, NO_MBCACHE)) {
5260 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5261 		if (!sbi->s_ea_block_cache) {
5262 			ext4_msg(sb, KERN_ERR,
5263 				 "Failed to create ea_block_cache");
5264 			goto failed_mount_wq;
5265 		}
5266 
5267 		if (ext4_has_feature_ea_inode(sb)) {
5268 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5269 			if (!sbi->s_ea_inode_cache) {
5270 				ext4_msg(sb, KERN_ERR,
5271 					 "Failed to create ea_inode_cache");
5272 				goto failed_mount_wq;
5273 			}
5274 		}
5275 	}
5276 
5277 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
5278 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5279 		goto failed_mount_wq;
5280 	}
5281 
5282 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
5283 	    !ext4_has_feature_encrypt(sb)) {
5284 		ext4_set_feature_encrypt(sb);
5285 		ext4_commit_super(sb);
5286 	}
5287 
5288 	/*
5289 	 * Get the # of file system overhead blocks from the
5290 	 * superblock if present.
5291 	 */
5292 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5293 	/* ignore the precalculated value if it is ridiculous */
5294 	if (sbi->s_overhead > ext4_blocks_count(es))
5295 		sbi->s_overhead = 0;
5296 	/*
5297 	 * If the bigalloc feature is not enabled recalculating the
5298 	 * overhead doesn't take long, so we might as well just redo
5299 	 * it to make sure we are using the correct value.
5300 	 */
5301 	if (!ext4_has_feature_bigalloc(sb))
5302 		sbi->s_overhead = 0;
5303 	if (sbi->s_overhead == 0) {
5304 		err = ext4_calculate_overhead(sb);
5305 		if (err)
5306 			goto failed_mount_wq;
5307 	}
5308 
5309 	/*
5310 	 * The maximum number of concurrent works can be high and
5311 	 * concurrency isn't really necessary.  Limit it to 1.
5312 	 */
5313 	EXT4_SB(sb)->rsv_conversion_wq =
5314 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5315 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5316 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5317 		ret = -ENOMEM;
5318 		goto failed_mount4;
5319 	}
5320 
5321 	/*
5322 	 * The jbd2_journal_load will have done any necessary log recovery,
5323 	 * so we can safely mount the rest of the filesystem now.
5324 	 */
5325 
5326 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5327 	if (IS_ERR(root)) {
5328 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5329 		ret = PTR_ERR(root);
5330 		root = NULL;
5331 		goto failed_mount4;
5332 	}
5333 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5334 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5335 		iput(root);
5336 		goto failed_mount4;
5337 	}
5338 
5339 	sb->s_root = d_make_root(root);
5340 	if (!sb->s_root) {
5341 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5342 		ret = -ENOMEM;
5343 		goto failed_mount4;
5344 	}
5345 
5346 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5347 	if (ret == -EROFS) {
5348 		sb->s_flags |= SB_RDONLY;
5349 		ret = 0;
5350 	} else if (ret)
5351 		goto failed_mount4a;
5352 
5353 	ext4_set_resv_clusters(sb);
5354 
5355 	if (test_opt(sb, BLOCK_VALIDITY)) {
5356 		err = ext4_setup_system_zone(sb);
5357 		if (err) {
5358 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5359 				 "zone (%d)", err);
5360 			goto failed_mount4a;
5361 		}
5362 	}
5363 	ext4_fc_replay_cleanup(sb);
5364 
5365 	ext4_ext_init(sb);
5366 
5367 	/*
5368 	 * Enable optimize_scan if number of groups is > threshold. This can be
5369 	 * turned off by passing "mb_optimize_scan=0". This can also be
5370 	 * turned on forcefully by passing "mb_optimize_scan=1".
5371 	 */
5372 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5373 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5374 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5375 		else
5376 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5377 	}
5378 
5379 	err = ext4_mb_init(sb);
5380 	if (err) {
5381 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5382 			 err);
5383 		goto failed_mount5;
5384 	}
5385 
5386 	/*
5387 	 * We can only set up the journal commit callback once
5388 	 * mballoc is initialized
5389 	 */
5390 	if (sbi->s_journal)
5391 		sbi->s_journal->j_commit_callback =
5392 			ext4_journal_commit_callback;
5393 
5394 	block = ext4_count_free_clusters(sb);
5395 	ext4_free_blocks_count_set(sbi->s_es,
5396 				   EXT4_C2B(sbi, block));
5397 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5398 				  GFP_KERNEL);
5399 	if (!err) {
5400 		unsigned long freei = ext4_count_free_inodes(sb);
5401 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5402 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5403 					  GFP_KERNEL);
5404 	}
5405 	/*
5406 	 * Update the checksum after updating free space/inode
5407 	 * counters.  Otherwise the superblock can have an incorrect
5408 	 * checksum in the buffer cache until it is written out and
5409 	 * e2fsprogs programs trying to open a file system immediately
5410 	 * after it is mounted can fail.
5411 	 */
5412 	ext4_superblock_csum_set(sb);
5413 	if (!err)
5414 		err = percpu_counter_init(&sbi->s_dirs_counter,
5415 					  ext4_count_dirs(sb), GFP_KERNEL);
5416 	if (!err)
5417 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5418 					  GFP_KERNEL);
5419 	if (!err)
5420 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5421 					  GFP_KERNEL);
5422 	if (!err)
5423 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5424 
5425 	if (err) {
5426 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5427 		goto failed_mount6;
5428 	}
5429 
5430 	if (ext4_has_feature_flex_bg(sb))
5431 		if (!ext4_fill_flex_info(sb)) {
5432 			ext4_msg(sb, KERN_ERR,
5433 			       "unable to initialize "
5434 			       "flex_bg meta info!");
5435 			ret = -ENOMEM;
5436 			goto failed_mount6;
5437 		}
5438 
5439 	err = ext4_register_li_request(sb, first_not_zeroed);
5440 	if (err)
5441 		goto failed_mount6;
5442 
5443 	err = ext4_register_sysfs(sb);
5444 	if (err)
5445 		goto failed_mount7;
5446 
5447 	err = ext4_init_orphan_info(sb);
5448 	if (err)
5449 		goto failed_mount8;
5450 #ifdef CONFIG_QUOTA
5451 	/* Enable quota usage during mount. */
5452 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5453 		err = ext4_enable_quotas(sb);
5454 		if (err)
5455 			goto failed_mount9;
5456 	}
5457 #endif  /* CONFIG_QUOTA */
5458 
5459 	/*
5460 	 * Save the original bdev mapping's wb_err value which could be
5461 	 * used to detect the metadata async write error.
5462 	 */
5463 	spin_lock_init(&sbi->s_bdev_wb_lock);
5464 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5465 				 &sbi->s_bdev_wb_err);
5466 	sb->s_bdev->bd_super = sb;
5467 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5468 	ext4_orphan_cleanup(sb, es);
5469 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5470 	if (needs_recovery) {
5471 		ext4_msg(sb, KERN_INFO, "recovery complete");
5472 		err = ext4_mark_recovery_complete(sb, es);
5473 		if (err)
5474 			goto failed_mount9;
5475 	}
5476 
5477 	if (test_opt(sb, DISCARD)) {
5478 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5479 		if (!blk_queue_discard(q))
5480 			ext4_msg(sb, KERN_WARNING,
5481 				 "mounting with \"discard\" option, but "
5482 				 "the device does not support discard");
5483 	}
5484 
5485 	if (es->s_error_count)
5486 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5487 
5488 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5489 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5490 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5491 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5492 	atomic_set(&sbi->s_warning_count, 0);
5493 	atomic_set(&sbi->s_msg_count, 0);
5494 
5495 	return 0;
5496 
5497 cantfind_ext4:
5498 	if (!silent)
5499 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5500 	goto failed_mount;
5501 
5502 failed_mount9:
5503 	ext4_release_orphan_info(sb);
5504 failed_mount8:
5505 	ext4_unregister_sysfs(sb);
5506 	kobject_put(&sbi->s_kobj);
5507 failed_mount7:
5508 	ext4_unregister_li_request(sb);
5509 failed_mount6:
5510 	ext4_mb_release(sb);
5511 	rcu_read_lock();
5512 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5513 	if (flex_groups) {
5514 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5515 			kvfree(flex_groups[i]);
5516 		kvfree(flex_groups);
5517 	}
5518 	rcu_read_unlock();
5519 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5520 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5521 	percpu_counter_destroy(&sbi->s_dirs_counter);
5522 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5523 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5524 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5525 failed_mount5:
5526 	ext4_ext_release(sb);
5527 	ext4_release_system_zone(sb);
5528 failed_mount4a:
5529 	dput(sb->s_root);
5530 	sb->s_root = NULL;
5531 failed_mount4:
5532 	ext4_msg(sb, KERN_ERR, "mount failed");
5533 	if (EXT4_SB(sb)->rsv_conversion_wq)
5534 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5535 failed_mount_wq:
5536 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5537 	sbi->s_ea_inode_cache = NULL;
5538 
5539 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5540 	sbi->s_ea_block_cache = NULL;
5541 
5542 	if (sbi->s_journal) {
5543 		/* flush s_error_work before journal destroy. */
5544 		flush_work(&sbi->s_error_work);
5545 		jbd2_journal_destroy(sbi->s_journal);
5546 		sbi->s_journal = NULL;
5547 	}
5548 failed_mount3a:
5549 	ext4_es_unregister_shrinker(sbi);
5550 failed_mount3:
5551 	/* flush s_error_work before sbi destroy */
5552 	flush_work(&sbi->s_error_work);
5553 	del_timer_sync(&sbi->s_err_report);
5554 	ext4_stop_mmpd(sbi);
5555 failed_mount2:
5556 	rcu_read_lock();
5557 	group_desc = rcu_dereference(sbi->s_group_desc);
5558 	for (i = 0; i < db_count; i++)
5559 		brelse(group_desc[i]);
5560 	kvfree(group_desc);
5561 	rcu_read_unlock();
5562 failed_mount:
5563 	if (sbi->s_chksum_driver)
5564 		crypto_free_shash(sbi->s_chksum_driver);
5565 
5566 #if IS_ENABLED(CONFIG_UNICODE)
5567 	utf8_unload(sb->s_encoding);
5568 #endif
5569 
5570 #ifdef CONFIG_QUOTA
5571 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5572 		kfree(get_qf_name(sb, sbi, i));
5573 #endif
5574 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5575 	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5576 	brelse(bh);
5577 	ext4_blkdev_remove(sbi);
5578 out_fail:
5579 	sb->s_fs_info = NULL;
5580 	return err ? err : ret;
5581 }
5582 
5583 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5584 {
5585 	struct ext4_fs_context *ctx = fc->fs_private;
5586 	struct ext4_sb_info *sbi;
5587 	const char *descr;
5588 	int ret;
5589 
5590 	sbi = ext4_alloc_sbi(sb);
5591 	if (!sbi)
5592 		return -ENOMEM;
5593 
5594 	fc->s_fs_info = sbi;
5595 
5596 	/* Cleanup superblock name */
5597 	strreplace(sb->s_id, '/', '!');
5598 
5599 	sbi->s_sb_block = 1;	/* Default super block location */
5600 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5601 		sbi->s_sb_block = ctx->s_sb_block;
5602 
5603 	ret = __ext4_fill_super(fc, sb);
5604 	if (ret < 0)
5605 		goto free_sbi;
5606 
5607 	if (sbi->s_journal) {
5608 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5609 			descr = " journalled data mode";
5610 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5611 			descr = " ordered data mode";
5612 		else
5613 			descr = " writeback data mode";
5614 	} else
5615 		descr = "out journal";
5616 
5617 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5618 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5619 			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
5620 
5621 	/* Update the s_overhead_clusters if necessary */
5622 	ext4_update_overhead(sb);
5623 	return 0;
5624 
5625 free_sbi:
5626 	ext4_free_sbi(sbi);
5627 	fc->s_fs_info = NULL;
5628 	return ret;
5629 }
5630 
5631 static int ext4_get_tree(struct fs_context *fc)
5632 {
5633 	return get_tree_bdev(fc, ext4_fill_super);
5634 }
5635 
5636 /*
5637  * Setup any per-fs journal parameters now.  We'll do this both on
5638  * initial mount, once the journal has been initialised but before we've
5639  * done any recovery; and again on any subsequent remount.
5640  */
5641 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5642 {
5643 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5644 
5645 	journal->j_commit_interval = sbi->s_commit_interval;
5646 	journal->j_min_batch_time = sbi->s_min_batch_time;
5647 	journal->j_max_batch_time = sbi->s_max_batch_time;
5648 	ext4_fc_init(sb, journal);
5649 
5650 	write_lock(&journal->j_state_lock);
5651 	if (test_opt(sb, BARRIER))
5652 		journal->j_flags |= JBD2_BARRIER;
5653 	else
5654 		journal->j_flags &= ~JBD2_BARRIER;
5655 	if (test_opt(sb, DATA_ERR_ABORT))
5656 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5657 	else
5658 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5659 	write_unlock(&journal->j_state_lock);
5660 }
5661 
5662 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5663 					     unsigned int journal_inum)
5664 {
5665 	struct inode *journal_inode;
5666 
5667 	/*
5668 	 * Test for the existence of a valid inode on disk.  Bad things
5669 	 * happen if we iget() an unused inode, as the subsequent iput()
5670 	 * will try to delete it.
5671 	 */
5672 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5673 	if (IS_ERR(journal_inode)) {
5674 		ext4_msg(sb, KERN_ERR, "no journal found");
5675 		return NULL;
5676 	}
5677 	if (!journal_inode->i_nlink) {
5678 		make_bad_inode(journal_inode);
5679 		iput(journal_inode);
5680 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5681 		return NULL;
5682 	}
5683 
5684 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5685 		  journal_inode, journal_inode->i_size);
5686 	if (!S_ISREG(journal_inode->i_mode)) {
5687 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5688 		iput(journal_inode);
5689 		return NULL;
5690 	}
5691 	return journal_inode;
5692 }
5693 
5694 static journal_t *ext4_get_journal(struct super_block *sb,
5695 				   unsigned int journal_inum)
5696 {
5697 	struct inode *journal_inode;
5698 	journal_t *journal;
5699 
5700 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5701 		return NULL;
5702 
5703 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5704 	if (!journal_inode)
5705 		return NULL;
5706 
5707 	journal = jbd2_journal_init_inode(journal_inode);
5708 	if (!journal) {
5709 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5710 		iput(journal_inode);
5711 		return NULL;
5712 	}
5713 	journal->j_private = sb;
5714 	ext4_init_journal_params(sb, journal);
5715 	return journal;
5716 }
5717 
5718 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5719 				       dev_t j_dev)
5720 {
5721 	struct buffer_head *bh;
5722 	journal_t *journal;
5723 	ext4_fsblk_t start;
5724 	ext4_fsblk_t len;
5725 	int hblock, blocksize;
5726 	ext4_fsblk_t sb_block;
5727 	unsigned long offset;
5728 	struct ext4_super_block *es;
5729 	struct block_device *bdev;
5730 
5731 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5732 		return NULL;
5733 
5734 	bdev = ext4_blkdev_get(j_dev, sb);
5735 	if (bdev == NULL)
5736 		return NULL;
5737 
5738 	blocksize = sb->s_blocksize;
5739 	hblock = bdev_logical_block_size(bdev);
5740 	if (blocksize < hblock) {
5741 		ext4_msg(sb, KERN_ERR,
5742 			"blocksize too small for journal device");
5743 		goto out_bdev;
5744 	}
5745 
5746 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5747 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5748 	set_blocksize(bdev, blocksize);
5749 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5750 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5751 		       "external journal");
5752 		goto out_bdev;
5753 	}
5754 
5755 	es = (struct ext4_super_block *) (bh->b_data + offset);
5756 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5757 	    !(le32_to_cpu(es->s_feature_incompat) &
5758 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5759 		ext4_msg(sb, KERN_ERR, "external journal has "
5760 					"bad superblock");
5761 		brelse(bh);
5762 		goto out_bdev;
5763 	}
5764 
5765 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5766 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5767 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5768 		ext4_msg(sb, KERN_ERR, "external journal has "
5769 				       "corrupt superblock");
5770 		brelse(bh);
5771 		goto out_bdev;
5772 	}
5773 
5774 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5775 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5776 		brelse(bh);
5777 		goto out_bdev;
5778 	}
5779 
5780 	len = ext4_blocks_count(es);
5781 	start = sb_block + 1;
5782 	brelse(bh);	/* we're done with the superblock */
5783 
5784 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5785 					start, len, blocksize);
5786 	if (!journal) {
5787 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5788 		goto out_bdev;
5789 	}
5790 	journal->j_private = sb;
5791 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5792 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5793 		goto out_journal;
5794 	}
5795 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5796 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5797 					"user (unsupported) - %d",
5798 			be32_to_cpu(journal->j_superblock->s_nr_users));
5799 		goto out_journal;
5800 	}
5801 	EXT4_SB(sb)->s_journal_bdev = bdev;
5802 	ext4_init_journal_params(sb, journal);
5803 	return journal;
5804 
5805 out_journal:
5806 	jbd2_journal_destroy(journal);
5807 out_bdev:
5808 	ext4_blkdev_put(bdev);
5809 	return NULL;
5810 }
5811 
5812 static int ext4_load_journal(struct super_block *sb,
5813 			     struct ext4_super_block *es,
5814 			     unsigned long journal_devnum)
5815 {
5816 	journal_t *journal;
5817 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5818 	dev_t journal_dev;
5819 	int err = 0;
5820 	int really_read_only;
5821 	int journal_dev_ro;
5822 
5823 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5824 		return -EFSCORRUPTED;
5825 
5826 	if (journal_devnum &&
5827 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5828 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5829 			"numbers have changed");
5830 		journal_dev = new_decode_dev(journal_devnum);
5831 	} else
5832 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5833 
5834 	if (journal_inum && journal_dev) {
5835 		ext4_msg(sb, KERN_ERR,
5836 			 "filesystem has both journal inode and journal device!");
5837 		return -EINVAL;
5838 	}
5839 
5840 	if (journal_inum) {
5841 		journal = ext4_get_journal(sb, journal_inum);
5842 		if (!journal)
5843 			return -EINVAL;
5844 	} else {
5845 		journal = ext4_get_dev_journal(sb, journal_dev);
5846 		if (!journal)
5847 			return -EINVAL;
5848 	}
5849 
5850 	journal_dev_ro = bdev_read_only(journal->j_dev);
5851 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5852 
5853 	if (journal_dev_ro && !sb_rdonly(sb)) {
5854 		ext4_msg(sb, KERN_ERR,
5855 			 "journal device read-only, try mounting with '-o ro'");
5856 		err = -EROFS;
5857 		goto err_out;
5858 	}
5859 
5860 	/*
5861 	 * Are we loading a blank journal or performing recovery after a
5862 	 * crash?  For recovery, we need to check in advance whether we
5863 	 * can get read-write access to the device.
5864 	 */
5865 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5866 		if (sb_rdonly(sb)) {
5867 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5868 					"required on readonly filesystem");
5869 			if (really_read_only) {
5870 				ext4_msg(sb, KERN_ERR, "write access "
5871 					"unavailable, cannot proceed "
5872 					"(try mounting with noload)");
5873 				err = -EROFS;
5874 				goto err_out;
5875 			}
5876 			ext4_msg(sb, KERN_INFO, "write access will "
5877 			       "be enabled during recovery");
5878 		}
5879 	}
5880 
5881 	if (!(journal->j_flags & JBD2_BARRIER))
5882 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5883 
5884 	if (!ext4_has_feature_journal_needs_recovery(sb))
5885 		err = jbd2_journal_wipe(journal, !really_read_only);
5886 	if (!err) {
5887 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5888 		if (save)
5889 			memcpy(save, ((char *) es) +
5890 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5891 		err = jbd2_journal_load(journal);
5892 		if (save)
5893 			memcpy(((char *) es) + EXT4_S_ERR_START,
5894 			       save, EXT4_S_ERR_LEN);
5895 		kfree(save);
5896 	}
5897 
5898 	if (err) {
5899 		ext4_msg(sb, KERN_ERR, "error loading journal");
5900 		goto err_out;
5901 	}
5902 
5903 	EXT4_SB(sb)->s_journal = journal;
5904 	err = ext4_clear_journal_err(sb, es);
5905 	if (err) {
5906 		EXT4_SB(sb)->s_journal = NULL;
5907 		jbd2_journal_destroy(journal);
5908 		return err;
5909 	}
5910 
5911 	if (!really_read_only && journal_devnum &&
5912 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5913 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5914 
5915 		/* Make sure we flush the recovery flag to disk. */
5916 		ext4_commit_super(sb);
5917 	}
5918 
5919 	return 0;
5920 
5921 err_out:
5922 	jbd2_journal_destroy(journal);
5923 	return err;
5924 }
5925 
5926 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5927 static void ext4_update_super(struct super_block *sb)
5928 {
5929 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5930 	struct ext4_super_block *es = sbi->s_es;
5931 	struct buffer_head *sbh = sbi->s_sbh;
5932 
5933 	lock_buffer(sbh);
5934 	/*
5935 	 * If the file system is mounted read-only, don't update the
5936 	 * superblock write time.  This avoids updating the superblock
5937 	 * write time when we are mounting the root file system
5938 	 * read/only but we need to replay the journal; at that point,
5939 	 * for people who are east of GMT and who make their clock
5940 	 * tick in localtime for Windows bug-for-bug compatibility,
5941 	 * the clock is set in the future, and this will cause e2fsck
5942 	 * to complain and force a full file system check.
5943 	 */
5944 	if (!(sb->s_flags & SB_RDONLY))
5945 		ext4_update_tstamp(es, s_wtime);
5946 	es->s_kbytes_written =
5947 		cpu_to_le64(sbi->s_kbytes_written +
5948 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5949 		      sbi->s_sectors_written_start) >> 1));
5950 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5951 		ext4_free_blocks_count_set(es,
5952 			EXT4_C2B(sbi, percpu_counter_sum_positive(
5953 				&sbi->s_freeclusters_counter)));
5954 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5955 		es->s_free_inodes_count =
5956 			cpu_to_le32(percpu_counter_sum_positive(
5957 				&sbi->s_freeinodes_counter));
5958 	/* Copy error information to the on-disk superblock */
5959 	spin_lock(&sbi->s_error_lock);
5960 	if (sbi->s_add_error_count > 0) {
5961 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5962 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5963 			__ext4_update_tstamp(&es->s_first_error_time,
5964 					     &es->s_first_error_time_hi,
5965 					     sbi->s_first_error_time);
5966 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
5967 				sizeof(es->s_first_error_func));
5968 			es->s_first_error_line =
5969 				cpu_to_le32(sbi->s_first_error_line);
5970 			es->s_first_error_ino =
5971 				cpu_to_le32(sbi->s_first_error_ino);
5972 			es->s_first_error_block =
5973 				cpu_to_le64(sbi->s_first_error_block);
5974 			es->s_first_error_errcode =
5975 				ext4_errno_to_code(sbi->s_first_error_code);
5976 		}
5977 		__ext4_update_tstamp(&es->s_last_error_time,
5978 				     &es->s_last_error_time_hi,
5979 				     sbi->s_last_error_time);
5980 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
5981 			sizeof(es->s_last_error_func));
5982 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5983 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5984 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5985 		es->s_last_error_errcode =
5986 				ext4_errno_to_code(sbi->s_last_error_code);
5987 		/*
5988 		 * Start the daily error reporting function if it hasn't been
5989 		 * started already
5990 		 */
5991 		if (!es->s_error_count)
5992 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5993 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5994 		sbi->s_add_error_count = 0;
5995 	}
5996 	spin_unlock(&sbi->s_error_lock);
5997 
5998 	ext4_superblock_csum_set(sb);
5999 	unlock_buffer(sbh);
6000 }
6001 
6002 static int ext4_commit_super(struct super_block *sb)
6003 {
6004 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6005 	int error = 0;
6006 
6007 	if (!sbh)
6008 		return -EINVAL;
6009 	if (block_device_ejected(sb))
6010 		return -ENODEV;
6011 
6012 	ext4_update_super(sb);
6013 
6014 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6015 		/*
6016 		 * Oh, dear.  A previous attempt to write the
6017 		 * superblock failed.  This could happen because the
6018 		 * USB device was yanked out.  Or it could happen to
6019 		 * be a transient write error and maybe the block will
6020 		 * be remapped.  Nothing we can do but to retry the
6021 		 * write and hope for the best.
6022 		 */
6023 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6024 		       "superblock detected");
6025 		clear_buffer_write_io_error(sbh);
6026 		set_buffer_uptodate(sbh);
6027 	}
6028 	BUFFER_TRACE(sbh, "marking dirty");
6029 	mark_buffer_dirty(sbh);
6030 	error = __sync_dirty_buffer(sbh,
6031 		REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
6032 	if (buffer_write_io_error(sbh)) {
6033 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6034 		       "superblock");
6035 		clear_buffer_write_io_error(sbh);
6036 		set_buffer_uptodate(sbh);
6037 	}
6038 	return error;
6039 }
6040 
6041 /*
6042  * Have we just finished recovery?  If so, and if we are mounting (or
6043  * remounting) the filesystem readonly, then we will end up with a
6044  * consistent fs on disk.  Record that fact.
6045  */
6046 static int ext4_mark_recovery_complete(struct super_block *sb,
6047 				       struct ext4_super_block *es)
6048 {
6049 	int err;
6050 	journal_t *journal = EXT4_SB(sb)->s_journal;
6051 
6052 	if (!ext4_has_feature_journal(sb)) {
6053 		if (journal != NULL) {
6054 			ext4_error(sb, "Journal got removed while the fs was "
6055 				   "mounted!");
6056 			return -EFSCORRUPTED;
6057 		}
6058 		return 0;
6059 	}
6060 	jbd2_journal_lock_updates(journal);
6061 	err = jbd2_journal_flush(journal, 0);
6062 	if (err < 0)
6063 		goto out;
6064 
6065 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6066 	    ext4_has_feature_orphan_present(sb))) {
6067 		if (!ext4_orphan_file_empty(sb)) {
6068 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6069 			err = -EFSCORRUPTED;
6070 			goto out;
6071 		}
6072 		ext4_clear_feature_journal_needs_recovery(sb);
6073 		ext4_clear_feature_orphan_present(sb);
6074 		ext4_commit_super(sb);
6075 	}
6076 out:
6077 	jbd2_journal_unlock_updates(journal);
6078 	return err;
6079 }
6080 
6081 /*
6082  * If we are mounting (or read-write remounting) a filesystem whose journal
6083  * has recorded an error from a previous lifetime, move that error to the
6084  * main filesystem now.
6085  */
6086 static int ext4_clear_journal_err(struct super_block *sb,
6087 				   struct ext4_super_block *es)
6088 {
6089 	journal_t *journal;
6090 	int j_errno;
6091 	const char *errstr;
6092 
6093 	if (!ext4_has_feature_journal(sb)) {
6094 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6095 		return -EFSCORRUPTED;
6096 	}
6097 
6098 	journal = EXT4_SB(sb)->s_journal;
6099 
6100 	/*
6101 	 * Now check for any error status which may have been recorded in the
6102 	 * journal by a prior ext4_error() or ext4_abort()
6103 	 */
6104 
6105 	j_errno = jbd2_journal_errno(journal);
6106 	if (j_errno) {
6107 		char nbuf[16];
6108 
6109 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6110 		ext4_warning(sb, "Filesystem error recorded "
6111 			     "from previous mount: %s", errstr);
6112 		ext4_warning(sb, "Marking fs in need of filesystem check.");
6113 
6114 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6115 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6116 		ext4_commit_super(sb);
6117 
6118 		jbd2_journal_clear_err(journal);
6119 		jbd2_journal_update_sb_errno(journal);
6120 	}
6121 	return 0;
6122 }
6123 
6124 /*
6125  * Force the running and committing transactions to commit,
6126  * and wait on the commit.
6127  */
6128 int ext4_force_commit(struct super_block *sb)
6129 {
6130 	journal_t *journal;
6131 
6132 	if (sb_rdonly(sb))
6133 		return 0;
6134 
6135 	journal = EXT4_SB(sb)->s_journal;
6136 	return ext4_journal_force_commit(journal);
6137 }
6138 
6139 static int ext4_sync_fs(struct super_block *sb, int wait)
6140 {
6141 	int ret = 0;
6142 	tid_t target;
6143 	bool needs_barrier = false;
6144 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6145 
6146 	if (unlikely(ext4_forced_shutdown(sbi)))
6147 		return 0;
6148 
6149 	trace_ext4_sync_fs(sb, wait);
6150 	flush_workqueue(sbi->rsv_conversion_wq);
6151 	/*
6152 	 * Writeback quota in non-journalled quota case - journalled quota has
6153 	 * no dirty dquots
6154 	 */
6155 	dquot_writeback_dquots(sb, -1);
6156 	/*
6157 	 * Data writeback is possible w/o journal transaction, so barrier must
6158 	 * being sent at the end of the function. But we can skip it if
6159 	 * transaction_commit will do it for us.
6160 	 */
6161 	if (sbi->s_journal) {
6162 		target = jbd2_get_latest_transaction(sbi->s_journal);
6163 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6164 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6165 			needs_barrier = true;
6166 
6167 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6168 			if (wait)
6169 				ret = jbd2_log_wait_commit(sbi->s_journal,
6170 							   target);
6171 		}
6172 	} else if (wait && test_opt(sb, BARRIER))
6173 		needs_barrier = true;
6174 	if (needs_barrier) {
6175 		int err;
6176 		err = blkdev_issue_flush(sb->s_bdev);
6177 		if (!ret)
6178 			ret = err;
6179 	}
6180 
6181 	return ret;
6182 }
6183 
6184 /*
6185  * LVM calls this function before a (read-only) snapshot is created.  This
6186  * gives us a chance to flush the journal completely and mark the fs clean.
6187  *
6188  * Note that only this function cannot bring a filesystem to be in a clean
6189  * state independently. It relies on upper layer to stop all data & metadata
6190  * modifications.
6191  */
6192 static int ext4_freeze(struct super_block *sb)
6193 {
6194 	int error = 0;
6195 	journal_t *journal;
6196 
6197 	if (sb_rdonly(sb))
6198 		return 0;
6199 
6200 	journal = EXT4_SB(sb)->s_journal;
6201 
6202 	if (journal) {
6203 		/* Now we set up the journal barrier. */
6204 		jbd2_journal_lock_updates(journal);
6205 
6206 		/*
6207 		 * Don't clear the needs_recovery flag if we failed to
6208 		 * flush the journal.
6209 		 */
6210 		error = jbd2_journal_flush(journal, 0);
6211 		if (error < 0)
6212 			goto out;
6213 
6214 		/* Journal blocked and flushed, clear needs_recovery flag. */
6215 		ext4_clear_feature_journal_needs_recovery(sb);
6216 		if (ext4_orphan_file_empty(sb))
6217 			ext4_clear_feature_orphan_present(sb);
6218 	}
6219 
6220 	error = ext4_commit_super(sb);
6221 out:
6222 	if (journal)
6223 		/* we rely on upper layer to stop further updates */
6224 		jbd2_journal_unlock_updates(journal);
6225 	return error;
6226 }
6227 
6228 /*
6229  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6230  * flag here, even though the filesystem is not technically dirty yet.
6231  */
6232 static int ext4_unfreeze(struct super_block *sb)
6233 {
6234 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6235 		return 0;
6236 
6237 	if (EXT4_SB(sb)->s_journal) {
6238 		/* Reset the needs_recovery flag before the fs is unlocked. */
6239 		ext4_set_feature_journal_needs_recovery(sb);
6240 		if (ext4_has_feature_orphan_file(sb))
6241 			ext4_set_feature_orphan_present(sb);
6242 	}
6243 
6244 	ext4_commit_super(sb);
6245 	return 0;
6246 }
6247 
6248 /*
6249  * Structure to save mount options for ext4_remount's benefit
6250  */
6251 struct ext4_mount_options {
6252 	unsigned long s_mount_opt;
6253 	unsigned long s_mount_opt2;
6254 	kuid_t s_resuid;
6255 	kgid_t s_resgid;
6256 	unsigned long s_commit_interval;
6257 	u32 s_min_batch_time, s_max_batch_time;
6258 #ifdef CONFIG_QUOTA
6259 	int s_jquota_fmt;
6260 	char *s_qf_names[EXT4_MAXQUOTAS];
6261 #endif
6262 };
6263 
6264 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6265 {
6266 	struct ext4_fs_context *ctx = fc->fs_private;
6267 	struct ext4_super_block *es;
6268 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6269 	unsigned long old_sb_flags;
6270 	struct ext4_mount_options old_opts;
6271 	ext4_group_t g;
6272 	int err = 0;
6273 #ifdef CONFIG_QUOTA
6274 	int enable_quota = 0;
6275 	int i, j;
6276 	char *to_free[EXT4_MAXQUOTAS];
6277 #endif
6278 
6279 	ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6280 
6281 	/* Store the original options */
6282 	old_sb_flags = sb->s_flags;
6283 	old_opts.s_mount_opt = sbi->s_mount_opt;
6284 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6285 	old_opts.s_resuid = sbi->s_resuid;
6286 	old_opts.s_resgid = sbi->s_resgid;
6287 	old_opts.s_commit_interval = sbi->s_commit_interval;
6288 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6289 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6290 #ifdef CONFIG_QUOTA
6291 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6292 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6293 		if (sbi->s_qf_names[i]) {
6294 			char *qf_name = get_qf_name(sb, sbi, i);
6295 
6296 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6297 			if (!old_opts.s_qf_names[i]) {
6298 				for (j = 0; j < i; j++)
6299 					kfree(old_opts.s_qf_names[j]);
6300 				return -ENOMEM;
6301 			}
6302 		} else
6303 			old_opts.s_qf_names[i] = NULL;
6304 #endif
6305 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6306 		ctx->journal_ioprio =
6307 			sbi->s_journal->j_task->io_context->ioprio;
6308 
6309 	ext4_apply_options(fc, sb);
6310 
6311 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6312 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6313 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6314 			 "during remount not supported; ignoring");
6315 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6316 	}
6317 
6318 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6319 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6320 			ext4_msg(sb, KERN_ERR, "can't mount with "
6321 				 "both data=journal and delalloc");
6322 			err = -EINVAL;
6323 			goto restore_opts;
6324 		}
6325 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6326 			ext4_msg(sb, KERN_ERR, "can't mount with "
6327 				 "both data=journal and dioread_nolock");
6328 			err = -EINVAL;
6329 			goto restore_opts;
6330 		}
6331 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6332 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6333 			ext4_msg(sb, KERN_ERR, "can't mount with "
6334 				"journal_async_commit in data=ordered mode");
6335 			err = -EINVAL;
6336 			goto restore_opts;
6337 		}
6338 	}
6339 
6340 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6341 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6342 		err = -EINVAL;
6343 		goto restore_opts;
6344 	}
6345 
6346 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6347 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6348 
6349 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6350 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6351 
6352 	es = sbi->s_es;
6353 
6354 	if (sbi->s_journal) {
6355 		ext4_init_journal_params(sb, sbi->s_journal);
6356 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6357 	}
6358 
6359 	/* Flush outstanding errors before changing fs state */
6360 	flush_work(&sbi->s_error_work);
6361 
6362 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6363 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6364 			err = -EROFS;
6365 			goto restore_opts;
6366 		}
6367 
6368 		if (fc->sb_flags & SB_RDONLY) {
6369 			err = sync_filesystem(sb);
6370 			if (err < 0)
6371 				goto restore_opts;
6372 			err = dquot_suspend(sb, -1);
6373 			if (err < 0)
6374 				goto restore_opts;
6375 
6376 			/*
6377 			 * First of all, the unconditional stuff we have to do
6378 			 * to disable replay of the journal when we next remount
6379 			 */
6380 			sb->s_flags |= SB_RDONLY;
6381 
6382 			/*
6383 			 * OK, test if we are remounting a valid rw partition
6384 			 * readonly, and if so set the rdonly flag and then
6385 			 * mark the partition as valid again.
6386 			 */
6387 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6388 			    (sbi->s_mount_state & EXT4_VALID_FS))
6389 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6390 
6391 			if (sbi->s_journal) {
6392 				/*
6393 				 * We let remount-ro finish even if marking fs
6394 				 * as clean failed...
6395 				 */
6396 				ext4_mark_recovery_complete(sb, es);
6397 			}
6398 		} else {
6399 			/* Make sure we can mount this feature set readwrite */
6400 			if (ext4_has_feature_readonly(sb) ||
6401 			    !ext4_feature_set_ok(sb, 0)) {
6402 				err = -EROFS;
6403 				goto restore_opts;
6404 			}
6405 			/*
6406 			 * Make sure the group descriptor checksums
6407 			 * are sane.  If they aren't, refuse to remount r/w.
6408 			 */
6409 			for (g = 0; g < sbi->s_groups_count; g++) {
6410 				struct ext4_group_desc *gdp =
6411 					ext4_get_group_desc(sb, g, NULL);
6412 
6413 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6414 					ext4_msg(sb, KERN_ERR,
6415 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6416 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6417 					       le16_to_cpu(gdp->bg_checksum));
6418 					err = -EFSBADCRC;
6419 					goto restore_opts;
6420 				}
6421 			}
6422 
6423 			/*
6424 			 * If we have an unprocessed orphan list hanging
6425 			 * around from a previously readonly bdev mount,
6426 			 * require a full umount/remount for now.
6427 			 */
6428 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6429 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6430 				       "remount RDWR because of unprocessed "
6431 				       "orphan inode list.  Please "
6432 				       "umount/remount instead");
6433 				err = -EINVAL;
6434 				goto restore_opts;
6435 			}
6436 
6437 			/*
6438 			 * Mounting a RDONLY partition read-write, so reread
6439 			 * and store the current valid flag.  (It may have
6440 			 * been changed by e2fsck since we originally mounted
6441 			 * the partition.)
6442 			 */
6443 			if (sbi->s_journal) {
6444 				err = ext4_clear_journal_err(sb, es);
6445 				if (err)
6446 					goto restore_opts;
6447 			}
6448 			sbi->s_mount_state = le16_to_cpu(es->s_state);
6449 
6450 			err = ext4_setup_super(sb, es, 0);
6451 			if (err)
6452 				goto restore_opts;
6453 
6454 			sb->s_flags &= ~SB_RDONLY;
6455 			if (ext4_has_feature_mmp(sb))
6456 				if (ext4_multi_mount_protect(sb,
6457 						le64_to_cpu(es->s_mmp_block))) {
6458 					err = -EROFS;
6459 					goto restore_opts;
6460 				}
6461 #ifdef CONFIG_QUOTA
6462 			enable_quota = 1;
6463 #endif
6464 		}
6465 	}
6466 
6467 	/*
6468 	 * Reinitialize lazy itable initialization thread based on
6469 	 * current settings
6470 	 */
6471 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6472 		ext4_unregister_li_request(sb);
6473 	else {
6474 		ext4_group_t first_not_zeroed;
6475 		first_not_zeroed = ext4_has_uninit_itable(sb);
6476 		ext4_register_li_request(sb, first_not_zeroed);
6477 	}
6478 
6479 	/*
6480 	 * Handle creation of system zone data early because it can fail.
6481 	 * Releasing of existing data is done when we are sure remount will
6482 	 * succeed.
6483 	 */
6484 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6485 		err = ext4_setup_system_zone(sb);
6486 		if (err)
6487 			goto restore_opts;
6488 	}
6489 
6490 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6491 		err = ext4_commit_super(sb);
6492 		if (err)
6493 			goto restore_opts;
6494 	}
6495 
6496 #ifdef CONFIG_QUOTA
6497 	/* Release old quota file names */
6498 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6499 		kfree(old_opts.s_qf_names[i]);
6500 	if (enable_quota) {
6501 		if (sb_any_quota_suspended(sb))
6502 			dquot_resume(sb, -1);
6503 		else if (ext4_has_feature_quota(sb)) {
6504 			err = ext4_enable_quotas(sb);
6505 			if (err)
6506 				goto restore_opts;
6507 		}
6508 	}
6509 #endif
6510 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6511 		ext4_release_system_zone(sb);
6512 
6513 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6514 		ext4_stop_mmpd(sbi);
6515 
6516 	return 0;
6517 
6518 restore_opts:
6519 	sb->s_flags = old_sb_flags;
6520 	sbi->s_mount_opt = old_opts.s_mount_opt;
6521 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6522 	sbi->s_resuid = old_opts.s_resuid;
6523 	sbi->s_resgid = old_opts.s_resgid;
6524 	sbi->s_commit_interval = old_opts.s_commit_interval;
6525 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6526 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6527 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6528 		ext4_release_system_zone(sb);
6529 #ifdef CONFIG_QUOTA
6530 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6531 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6532 		to_free[i] = get_qf_name(sb, sbi, i);
6533 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6534 	}
6535 	synchronize_rcu();
6536 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6537 		kfree(to_free[i]);
6538 #endif
6539 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6540 		ext4_stop_mmpd(sbi);
6541 	return err;
6542 }
6543 
6544 static int ext4_reconfigure(struct fs_context *fc)
6545 {
6546 	struct super_block *sb = fc->root->d_sb;
6547 	int ret;
6548 
6549 	fc->s_fs_info = EXT4_SB(sb);
6550 
6551 	ret = ext4_check_opt_consistency(fc, sb);
6552 	if (ret < 0)
6553 		return ret;
6554 
6555 	ret = __ext4_remount(fc, sb);
6556 	if (ret < 0)
6557 		return ret;
6558 
6559 	ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6560 		 ext4_quota_mode(sb));
6561 
6562 	return 0;
6563 }
6564 
6565 #ifdef CONFIG_QUOTA
6566 static int ext4_statfs_project(struct super_block *sb,
6567 			       kprojid_t projid, struct kstatfs *buf)
6568 {
6569 	struct kqid qid;
6570 	struct dquot *dquot;
6571 	u64 limit;
6572 	u64 curblock;
6573 
6574 	qid = make_kqid_projid(projid);
6575 	dquot = dqget(sb, qid);
6576 	if (IS_ERR(dquot))
6577 		return PTR_ERR(dquot);
6578 	spin_lock(&dquot->dq_dqb_lock);
6579 
6580 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6581 			     dquot->dq_dqb.dqb_bhardlimit);
6582 	limit >>= sb->s_blocksize_bits;
6583 
6584 	if (limit && buf->f_blocks > limit) {
6585 		curblock = (dquot->dq_dqb.dqb_curspace +
6586 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6587 		buf->f_blocks = limit;
6588 		buf->f_bfree = buf->f_bavail =
6589 			(buf->f_blocks > curblock) ?
6590 			 (buf->f_blocks - curblock) : 0;
6591 	}
6592 
6593 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6594 			     dquot->dq_dqb.dqb_ihardlimit);
6595 	if (limit && buf->f_files > limit) {
6596 		buf->f_files = limit;
6597 		buf->f_ffree =
6598 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6599 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6600 	}
6601 
6602 	spin_unlock(&dquot->dq_dqb_lock);
6603 	dqput(dquot);
6604 	return 0;
6605 }
6606 #endif
6607 
6608 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6609 {
6610 	struct super_block *sb = dentry->d_sb;
6611 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6612 	struct ext4_super_block *es = sbi->s_es;
6613 	ext4_fsblk_t overhead = 0, resv_blocks;
6614 	s64 bfree;
6615 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6616 
6617 	if (!test_opt(sb, MINIX_DF))
6618 		overhead = sbi->s_overhead;
6619 
6620 	buf->f_type = EXT4_SUPER_MAGIC;
6621 	buf->f_bsize = sb->s_blocksize;
6622 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6623 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6624 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6625 	/* prevent underflow in case that few free space is available */
6626 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6627 	buf->f_bavail = buf->f_bfree -
6628 			(ext4_r_blocks_count(es) + resv_blocks);
6629 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6630 		buf->f_bavail = 0;
6631 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6632 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6633 	buf->f_namelen = EXT4_NAME_LEN;
6634 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6635 
6636 #ifdef CONFIG_QUOTA
6637 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6638 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6639 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6640 #endif
6641 	return 0;
6642 }
6643 
6644 
6645 #ifdef CONFIG_QUOTA
6646 
6647 /*
6648  * Helper functions so that transaction is started before we acquire dqio_sem
6649  * to keep correct lock ordering of transaction > dqio_sem
6650  */
6651 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6652 {
6653 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6654 }
6655 
6656 static int ext4_write_dquot(struct dquot *dquot)
6657 {
6658 	int ret, err;
6659 	handle_t *handle;
6660 	struct inode *inode;
6661 
6662 	inode = dquot_to_inode(dquot);
6663 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6664 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6665 	if (IS_ERR(handle))
6666 		return PTR_ERR(handle);
6667 	ret = dquot_commit(dquot);
6668 	err = ext4_journal_stop(handle);
6669 	if (!ret)
6670 		ret = err;
6671 	return ret;
6672 }
6673 
6674 static int ext4_acquire_dquot(struct dquot *dquot)
6675 {
6676 	int ret, err;
6677 	handle_t *handle;
6678 
6679 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6680 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6681 	if (IS_ERR(handle))
6682 		return PTR_ERR(handle);
6683 	ret = dquot_acquire(dquot);
6684 	err = ext4_journal_stop(handle);
6685 	if (!ret)
6686 		ret = err;
6687 	return ret;
6688 }
6689 
6690 static int ext4_release_dquot(struct dquot *dquot)
6691 {
6692 	int ret, err;
6693 	handle_t *handle;
6694 
6695 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6696 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6697 	if (IS_ERR(handle)) {
6698 		/* Release dquot anyway to avoid endless cycle in dqput() */
6699 		dquot_release(dquot);
6700 		return PTR_ERR(handle);
6701 	}
6702 	ret = dquot_release(dquot);
6703 	err = ext4_journal_stop(handle);
6704 	if (!ret)
6705 		ret = err;
6706 	return ret;
6707 }
6708 
6709 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6710 {
6711 	struct super_block *sb = dquot->dq_sb;
6712 
6713 	if (ext4_is_quota_journalled(sb)) {
6714 		dquot_mark_dquot_dirty(dquot);
6715 		return ext4_write_dquot(dquot);
6716 	} else {
6717 		return dquot_mark_dquot_dirty(dquot);
6718 	}
6719 }
6720 
6721 static int ext4_write_info(struct super_block *sb, int type)
6722 {
6723 	int ret, err;
6724 	handle_t *handle;
6725 
6726 	/* Data block + inode block */
6727 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6728 	if (IS_ERR(handle))
6729 		return PTR_ERR(handle);
6730 	ret = dquot_commit_info(sb, type);
6731 	err = ext4_journal_stop(handle);
6732 	if (!ret)
6733 		ret = err;
6734 	return ret;
6735 }
6736 
6737 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6738 {
6739 	struct ext4_inode_info *ei = EXT4_I(inode);
6740 
6741 	/* The first argument of lockdep_set_subclass has to be
6742 	 * *exactly* the same as the argument to init_rwsem() --- in
6743 	 * this case, in init_once() --- or lockdep gets unhappy
6744 	 * because the name of the lock is set using the
6745 	 * stringification of the argument to init_rwsem().
6746 	 */
6747 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6748 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6749 }
6750 
6751 /*
6752  * Standard function to be called on quota_on
6753  */
6754 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6755 			 const struct path *path)
6756 {
6757 	int err;
6758 
6759 	if (!test_opt(sb, QUOTA))
6760 		return -EINVAL;
6761 
6762 	/* Quotafile not on the same filesystem? */
6763 	if (path->dentry->d_sb != sb)
6764 		return -EXDEV;
6765 
6766 	/* Quota already enabled for this file? */
6767 	if (IS_NOQUOTA(d_inode(path->dentry)))
6768 		return -EBUSY;
6769 
6770 	/* Journaling quota? */
6771 	if (EXT4_SB(sb)->s_qf_names[type]) {
6772 		/* Quotafile not in fs root? */
6773 		if (path->dentry->d_parent != sb->s_root)
6774 			ext4_msg(sb, KERN_WARNING,
6775 				"Quota file not on filesystem root. "
6776 				"Journaled quota will not work");
6777 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6778 	} else {
6779 		/*
6780 		 * Clear the flag just in case mount options changed since
6781 		 * last time.
6782 		 */
6783 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6784 	}
6785 
6786 	/*
6787 	 * When we journal data on quota file, we have to flush journal to see
6788 	 * all updates to the file when we bypass pagecache...
6789 	 */
6790 	if (EXT4_SB(sb)->s_journal &&
6791 	    ext4_should_journal_data(d_inode(path->dentry))) {
6792 		/*
6793 		 * We don't need to lock updates but journal_flush() could
6794 		 * otherwise be livelocked...
6795 		 */
6796 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6797 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6798 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6799 		if (err)
6800 			return err;
6801 	}
6802 
6803 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6804 	err = dquot_quota_on(sb, type, format_id, path);
6805 	if (!err) {
6806 		struct inode *inode = d_inode(path->dentry);
6807 		handle_t *handle;
6808 
6809 		/*
6810 		 * Set inode flags to prevent userspace from messing with quota
6811 		 * files. If this fails, we return success anyway since quotas
6812 		 * are already enabled and this is not a hard failure.
6813 		 */
6814 		inode_lock(inode);
6815 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6816 		if (IS_ERR(handle))
6817 			goto unlock_inode;
6818 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6819 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6820 				S_NOATIME | S_IMMUTABLE);
6821 		err = ext4_mark_inode_dirty(handle, inode);
6822 		ext4_journal_stop(handle);
6823 	unlock_inode:
6824 		inode_unlock(inode);
6825 		if (err)
6826 			dquot_quota_off(sb, type);
6827 	}
6828 	if (err)
6829 		lockdep_set_quota_inode(path->dentry->d_inode,
6830 					     I_DATA_SEM_NORMAL);
6831 	return err;
6832 }
6833 
6834 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6835 			     unsigned int flags)
6836 {
6837 	int err;
6838 	struct inode *qf_inode;
6839 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6840 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6841 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6842 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6843 	};
6844 
6845 	BUG_ON(!ext4_has_feature_quota(sb));
6846 
6847 	if (!qf_inums[type])
6848 		return -EPERM;
6849 
6850 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6851 	if (IS_ERR(qf_inode)) {
6852 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6853 		return PTR_ERR(qf_inode);
6854 	}
6855 
6856 	/* Don't account quota for quota files to avoid recursion */
6857 	qf_inode->i_flags |= S_NOQUOTA;
6858 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6859 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6860 	if (err)
6861 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6862 	iput(qf_inode);
6863 
6864 	return err;
6865 }
6866 
6867 /* Enable usage tracking for all quota types. */
6868 int ext4_enable_quotas(struct super_block *sb)
6869 {
6870 	int type, err = 0;
6871 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6872 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6873 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6874 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6875 	};
6876 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6877 		test_opt(sb, USRQUOTA),
6878 		test_opt(sb, GRPQUOTA),
6879 		test_opt(sb, PRJQUOTA),
6880 	};
6881 
6882 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6883 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6884 		if (qf_inums[type]) {
6885 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6886 				DQUOT_USAGE_ENABLED |
6887 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6888 			if (err) {
6889 				ext4_warning(sb,
6890 					"Failed to enable quota tracking "
6891 					"(type=%d, err=%d). Please run "
6892 					"e2fsck to fix.", type, err);
6893 				for (type--; type >= 0; type--) {
6894 					struct inode *inode;
6895 
6896 					inode = sb_dqopt(sb)->files[type];
6897 					if (inode)
6898 						inode = igrab(inode);
6899 					dquot_quota_off(sb, type);
6900 					if (inode) {
6901 						lockdep_set_quota_inode(inode,
6902 							I_DATA_SEM_NORMAL);
6903 						iput(inode);
6904 					}
6905 				}
6906 
6907 				return err;
6908 			}
6909 		}
6910 	}
6911 	return 0;
6912 }
6913 
6914 static int ext4_quota_off(struct super_block *sb, int type)
6915 {
6916 	struct inode *inode = sb_dqopt(sb)->files[type];
6917 	handle_t *handle;
6918 	int err;
6919 
6920 	/* Force all delayed allocation blocks to be allocated.
6921 	 * Caller already holds s_umount sem */
6922 	if (test_opt(sb, DELALLOC))
6923 		sync_filesystem(sb);
6924 
6925 	if (!inode || !igrab(inode))
6926 		goto out;
6927 
6928 	err = dquot_quota_off(sb, type);
6929 	if (err || ext4_has_feature_quota(sb))
6930 		goto out_put;
6931 
6932 	inode_lock(inode);
6933 	/*
6934 	 * Update modification times of quota files when userspace can
6935 	 * start looking at them. If we fail, we return success anyway since
6936 	 * this is not a hard failure and quotas are already disabled.
6937 	 */
6938 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6939 	if (IS_ERR(handle)) {
6940 		err = PTR_ERR(handle);
6941 		goto out_unlock;
6942 	}
6943 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6944 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6945 	inode->i_mtime = inode->i_ctime = current_time(inode);
6946 	err = ext4_mark_inode_dirty(handle, inode);
6947 	ext4_journal_stop(handle);
6948 out_unlock:
6949 	inode_unlock(inode);
6950 out_put:
6951 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6952 	iput(inode);
6953 	return err;
6954 out:
6955 	return dquot_quota_off(sb, type);
6956 }
6957 
6958 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6959  * acquiring the locks... As quota files are never truncated and quota code
6960  * itself serializes the operations (and no one else should touch the files)
6961  * we don't have to be afraid of races */
6962 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6963 			       size_t len, loff_t off)
6964 {
6965 	struct inode *inode = sb_dqopt(sb)->files[type];
6966 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6967 	int offset = off & (sb->s_blocksize - 1);
6968 	int tocopy;
6969 	size_t toread;
6970 	struct buffer_head *bh;
6971 	loff_t i_size = i_size_read(inode);
6972 
6973 	if (off > i_size)
6974 		return 0;
6975 	if (off+len > i_size)
6976 		len = i_size-off;
6977 	toread = len;
6978 	while (toread > 0) {
6979 		tocopy = sb->s_blocksize - offset < toread ?
6980 				sb->s_blocksize - offset : toread;
6981 		bh = ext4_bread(NULL, inode, blk, 0);
6982 		if (IS_ERR(bh))
6983 			return PTR_ERR(bh);
6984 		if (!bh)	/* A hole? */
6985 			memset(data, 0, tocopy);
6986 		else
6987 			memcpy(data, bh->b_data+offset, tocopy);
6988 		brelse(bh);
6989 		offset = 0;
6990 		toread -= tocopy;
6991 		data += tocopy;
6992 		blk++;
6993 	}
6994 	return len;
6995 }
6996 
6997 /* Write to quotafile (we know the transaction is already started and has
6998  * enough credits) */
6999 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7000 				const char *data, size_t len, loff_t off)
7001 {
7002 	struct inode *inode = sb_dqopt(sb)->files[type];
7003 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7004 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7005 	int retries = 0;
7006 	struct buffer_head *bh;
7007 	handle_t *handle = journal_current_handle();
7008 
7009 	if (!handle) {
7010 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7011 			" cancelled because transaction is not started",
7012 			(unsigned long long)off, (unsigned long long)len);
7013 		return -EIO;
7014 	}
7015 	/*
7016 	 * Since we account only one data block in transaction credits,
7017 	 * then it is impossible to cross a block boundary.
7018 	 */
7019 	if (sb->s_blocksize - offset < len) {
7020 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7021 			" cancelled because not block aligned",
7022 			(unsigned long long)off, (unsigned long long)len);
7023 		return -EIO;
7024 	}
7025 
7026 	do {
7027 		bh = ext4_bread(handle, inode, blk,
7028 				EXT4_GET_BLOCKS_CREATE |
7029 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7030 	} while (PTR_ERR(bh) == -ENOSPC &&
7031 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7032 	if (IS_ERR(bh))
7033 		return PTR_ERR(bh);
7034 	if (!bh)
7035 		goto out;
7036 	BUFFER_TRACE(bh, "get write access");
7037 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7038 	if (err) {
7039 		brelse(bh);
7040 		return err;
7041 	}
7042 	lock_buffer(bh);
7043 	memcpy(bh->b_data+offset, data, len);
7044 	flush_dcache_page(bh->b_page);
7045 	unlock_buffer(bh);
7046 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7047 	brelse(bh);
7048 out:
7049 	if (inode->i_size < off + len) {
7050 		i_size_write(inode, off + len);
7051 		EXT4_I(inode)->i_disksize = inode->i_size;
7052 		err2 = ext4_mark_inode_dirty(handle, inode);
7053 		if (unlikely(err2 && !err))
7054 			err = err2;
7055 	}
7056 	return err ? err : len;
7057 }
7058 #endif
7059 
7060 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7061 static inline void register_as_ext2(void)
7062 {
7063 	int err = register_filesystem(&ext2_fs_type);
7064 	if (err)
7065 		printk(KERN_WARNING
7066 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7067 }
7068 
7069 static inline void unregister_as_ext2(void)
7070 {
7071 	unregister_filesystem(&ext2_fs_type);
7072 }
7073 
7074 static inline int ext2_feature_set_ok(struct super_block *sb)
7075 {
7076 	if (ext4_has_unknown_ext2_incompat_features(sb))
7077 		return 0;
7078 	if (sb_rdonly(sb))
7079 		return 1;
7080 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7081 		return 0;
7082 	return 1;
7083 }
7084 #else
7085 static inline void register_as_ext2(void) { }
7086 static inline void unregister_as_ext2(void) { }
7087 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7088 #endif
7089 
7090 static inline void register_as_ext3(void)
7091 {
7092 	int err = register_filesystem(&ext3_fs_type);
7093 	if (err)
7094 		printk(KERN_WARNING
7095 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7096 }
7097 
7098 static inline void unregister_as_ext3(void)
7099 {
7100 	unregister_filesystem(&ext3_fs_type);
7101 }
7102 
7103 static inline int ext3_feature_set_ok(struct super_block *sb)
7104 {
7105 	if (ext4_has_unknown_ext3_incompat_features(sb))
7106 		return 0;
7107 	if (!ext4_has_feature_journal(sb))
7108 		return 0;
7109 	if (sb_rdonly(sb))
7110 		return 1;
7111 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7112 		return 0;
7113 	return 1;
7114 }
7115 
7116 static struct file_system_type ext4_fs_type = {
7117 	.owner			= THIS_MODULE,
7118 	.name			= "ext4",
7119 	.init_fs_context	= ext4_init_fs_context,
7120 	.parameters		= ext4_param_specs,
7121 	.kill_sb		= kill_block_super,
7122 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7123 };
7124 MODULE_ALIAS_FS("ext4");
7125 
7126 /* Shared across all ext4 file systems */
7127 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7128 
7129 static int __init ext4_init_fs(void)
7130 {
7131 	int i, err;
7132 
7133 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7134 	ext4_li_info = NULL;
7135 
7136 	/* Build-time check for flags consistency */
7137 	ext4_check_flag_values();
7138 
7139 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7140 		init_waitqueue_head(&ext4__ioend_wq[i]);
7141 
7142 	err = ext4_init_es();
7143 	if (err)
7144 		return err;
7145 
7146 	err = ext4_init_pending();
7147 	if (err)
7148 		goto out7;
7149 
7150 	err = ext4_init_post_read_processing();
7151 	if (err)
7152 		goto out6;
7153 
7154 	err = ext4_init_pageio();
7155 	if (err)
7156 		goto out5;
7157 
7158 	err = ext4_init_system_zone();
7159 	if (err)
7160 		goto out4;
7161 
7162 	err = ext4_init_sysfs();
7163 	if (err)
7164 		goto out3;
7165 
7166 	err = ext4_init_mballoc();
7167 	if (err)
7168 		goto out2;
7169 	err = init_inodecache();
7170 	if (err)
7171 		goto out1;
7172 
7173 	err = ext4_fc_init_dentry_cache();
7174 	if (err)
7175 		goto out05;
7176 
7177 	register_as_ext3();
7178 	register_as_ext2();
7179 	err = register_filesystem(&ext4_fs_type);
7180 	if (err)
7181 		goto out;
7182 
7183 	return 0;
7184 out:
7185 	unregister_as_ext2();
7186 	unregister_as_ext3();
7187 	ext4_fc_destroy_dentry_cache();
7188 out05:
7189 	destroy_inodecache();
7190 out1:
7191 	ext4_exit_mballoc();
7192 out2:
7193 	ext4_exit_sysfs();
7194 out3:
7195 	ext4_exit_system_zone();
7196 out4:
7197 	ext4_exit_pageio();
7198 out5:
7199 	ext4_exit_post_read_processing();
7200 out6:
7201 	ext4_exit_pending();
7202 out7:
7203 	ext4_exit_es();
7204 
7205 	return err;
7206 }
7207 
7208 static void __exit ext4_exit_fs(void)
7209 {
7210 	ext4_destroy_lazyinit_thread();
7211 	unregister_as_ext2();
7212 	unregister_as_ext3();
7213 	unregister_filesystem(&ext4_fs_type);
7214 	ext4_fc_destroy_dentry_cache();
7215 	destroy_inodecache();
7216 	ext4_exit_mballoc();
7217 	ext4_exit_sysfs();
7218 	ext4_exit_system_zone();
7219 	ext4_exit_pageio();
7220 	ext4_exit_post_read_processing();
7221 	ext4_exit_es();
7222 	ext4_exit_pending();
7223 }
7224 
7225 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7226 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7227 MODULE_LICENSE("GPL");
7228 MODULE_SOFTDEP("pre: crc32c");
7229 module_init(ext4_init_fs)
7230 module_exit(ext4_exit_fs)
7231