xref: /openbmc/linux/fs/ext4/super.c (revision 6fcd6fea)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/uaccess.h>
43 #include <linux/iversion.h>
44 #include <linux/unicode.h>
45 #include <linux/part_stat.h>
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 #include <linux/fsnotify.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 
52 #include "ext4.h"
53 #include "ext4_extents.h"	/* Needed for trace points definition */
54 #include "ext4_jbd2.h"
55 #include "xattr.h"
56 #include "acl.h"
57 #include "mballoc.h"
58 #include "fsmap.h"
59 
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/ext4.h>
62 
63 static struct ext4_lazy_init *ext4_li_info;
64 static DEFINE_MUTEX(ext4_li_mtx);
65 static struct ratelimit_state ext4_mount_msg_ratelimit;
66 
67 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
68 			     unsigned long journal_devnum);
69 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
70 static void ext4_update_super(struct super_block *sb);
71 static int ext4_commit_super(struct super_block *sb);
72 static int ext4_mark_recovery_complete(struct super_block *sb,
73 					struct ext4_super_block *es);
74 static int ext4_clear_journal_err(struct super_block *sb,
75 				  struct ext4_super_block *es);
76 static int ext4_sync_fs(struct super_block *sb, int wait);
77 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
78 static int ext4_unfreeze(struct super_block *sb);
79 static int ext4_freeze(struct super_block *sb);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 static int ext4_validate_options(struct fs_context *fc);
88 static int ext4_check_opt_consistency(struct fs_context *fc,
89 				      struct super_block *sb);
90 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
91 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
92 static int ext4_get_tree(struct fs_context *fc);
93 static int ext4_reconfigure(struct fs_context *fc);
94 static void ext4_fc_free(struct fs_context *fc);
95 static int ext4_init_fs_context(struct fs_context *fc);
96 static void ext4_kill_sb(struct super_block *sb);
97 static const struct fs_parameter_spec ext4_param_specs[];
98 
99 /*
100  * Lock ordering
101  *
102  * page fault path:
103  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
104  *   -> page lock -> i_data_sem (rw)
105  *
106  * buffered write path:
107  * sb_start_write -> i_mutex -> mmap_lock
108  * sb_start_write -> i_mutex -> transaction start -> page lock ->
109  *   i_data_sem (rw)
110  *
111  * truncate:
112  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
113  *   page lock
114  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
115  *   i_data_sem (rw)
116  *
117  * direct IO:
118  * sb_start_write -> i_mutex -> mmap_lock
119  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
120  *
121  * writepages:
122  * transaction start -> page lock(s) -> i_data_sem (rw)
123  */
124 
125 static const struct fs_context_operations ext4_context_ops = {
126 	.parse_param	= ext4_parse_param,
127 	.get_tree	= ext4_get_tree,
128 	.reconfigure	= ext4_reconfigure,
129 	.free		= ext4_fc_free,
130 };
131 
132 
133 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
134 static struct file_system_type ext2_fs_type = {
135 	.owner			= THIS_MODULE,
136 	.name			= "ext2",
137 	.init_fs_context	= ext4_init_fs_context,
138 	.parameters		= ext4_param_specs,
139 	.kill_sb		= ext4_kill_sb,
140 	.fs_flags		= FS_REQUIRES_DEV,
141 };
142 MODULE_ALIAS_FS("ext2");
143 MODULE_ALIAS("ext2");
144 #define IS_EXT2_SB(sb) ((sb)->s_type == &ext2_fs_type)
145 #else
146 #define IS_EXT2_SB(sb) (0)
147 #endif
148 
149 
150 static struct file_system_type ext3_fs_type = {
151 	.owner			= THIS_MODULE,
152 	.name			= "ext3",
153 	.init_fs_context	= ext4_init_fs_context,
154 	.parameters		= ext4_param_specs,
155 	.kill_sb		= ext4_kill_sb,
156 	.fs_flags		= FS_REQUIRES_DEV,
157 };
158 MODULE_ALIAS_FS("ext3");
159 MODULE_ALIAS("ext3");
160 #define IS_EXT3_SB(sb) ((sb)->s_type == &ext3_fs_type)
161 
162 
163 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
164 				  bh_end_io_t *end_io)
165 {
166 	/*
167 	 * buffer's verified bit is no longer valid after reading from
168 	 * disk again due to write out error, clear it to make sure we
169 	 * recheck the buffer contents.
170 	 */
171 	clear_buffer_verified(bh);
172 
173 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
174 	get_bh(bh);
175 	submit_bh(REQ_OP_READ | op_flags, bh);
176 }
177 
178 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
179 			 bh_end_io_t *end_io)
180 {
181 	BUG_ON(!buffer_locked(bh));
182 
183 	if (ext4_buffer_uptodate(bh)) {
184 		unlock_buffer(bh);
185 		return;
186 	}
187 	__ext4_read_bh(bh, op_flags, end_io);
188 }
189 
190 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
191 {
192 	BUG_ON(!buffer_locked(bh));
193 
194 	if (ext4_buffer_uptodate(bh)) {
195 		unlock_buffer(bh);
196 		return 0;
197 	}
198 
199 	__ext4_read_bh(bh, op_flags, end_io);
200 
201 	wait_on_buffer(bh);
202 	if (buffer_uptodate(bh))
203 		return 0;
204 	return -EIO;
205 }
206 
207 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
208 {
209 	lock_buffer(bh);
210 	if (!wait) {
211 		ext4_read_bh_nowait(bh, op_flags, NULL);
212 		return 0;
213 	}
214 	return ext4_read_bh(bh, op_flags, NULL);
215 }
216 
217 /*
218  * This works like __bread_gfp() except it uses ERR_PTR for error
219  * returns.  Currently with sb_bread it's impossible to distinguish
220  * between ENOMEM and EIO situations (since both result in a NULL
221  * return.
222  */
223 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
224 					       sector_t block,
225 					       blk_opf_t op_flags, gfp_t gfp)
226 {
227 	struct buffer_head *bh;
228 	int ret;
229 
230 	bh = sb_getblk_gfp(sb, block, gfp);
231 	if (bh == NULL)
232 		return ERR_PTR(-ENOMEM);
233 	if (ext4_buffer_uptodate(bh))
234 		return bh;
235 
236 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
237 	if (ret) {
238 		put_bh(bh);
239 		return ERR_PTR(ret);
240 	}
241 	return bh;
242 }
243 
244 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
245 				   blk_opf_t op_flags)
246 {
247 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
248 }
249 
250 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
251 					    sector_t block)
252 {
253 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
254 }
255 
256 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
257 {
258 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
259 
260 	if (likely(bh)) {
261 		if (trylock_buffer(bh))
262 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
263 		brelse(bh);
264 	}
265 }
266 
267 static int ext4_verify_csum_type(struct super_block *sb,
268 				 struct ext4_super_block *es)
269 {
270 	if (!ext4_has_feature_metadata_csum(sb))
271 		return 1;
272 
273 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
274 }
275 
276 __le32 ext4_superblock_csum(struct super_block *sb,
277 			    struct ext4_super_block *es)
278 {
279 	struct ext4_sb_info *sbi = EXT4_SB(sb);
280 	int offset = offsetof(struct ext4_super_block, s_checksum);
281 	__u32 csum;
282 
283 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
284 
285 	return cpu_to_le32(csum);
286 }
287 
288 static int ext4_superblock_csum_verify(struct super_block *sb,
289 				       struct ext4_super_block *es)
290 {
291 	if (!ext4_has_metadata_csum(sb))
292 		return 1;
293 
294 	return es->s_checksum == ext4_superblock_csum(sb, es);
295 }
296 
297 void ext4_superblock_csum_set(struct super_block *sb)
298 {
299 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
300 
301 	if (!ext4_has_metadata_csum(sb))
302 		return;
303 
304 	es->s_checksum = ext4_superblock_csum(sb, es);
305 }
306 
307 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
308 			       struct ext4_group_desc *bg)
309 {
310 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
311 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
312 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
313 }
314 
315 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
316 			       struct ext4_group_desc *bg)
317 {
318 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
319 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
320 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
321 }
322 
323 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
324 			      struct ext4_group_desc *bg)
325 {
326 	return le32_to_cpu(bg->bg_inode_table_lo) |
327 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
328 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
329 }
330 
331 __u32 ext4_free_group_clusters(struct super_block *sb,
332 			       struct ext4_group_desc *bg)
333 {
334 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
335 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
336 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
337 }
338 
339 __u32 ext4_free_inodes_count(struct super_block *sb,
340 			      struct ext4_group_desc *bg)
341 {
342 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
343 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
344 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
345 }
346 
347 __u32 ext4_used_dirs_count(struct super_block *sb,
348 			      struct ext4_group_desc *bg)
349 {
350 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
351 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
352 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
353 }
354 
355 __u32 ext4_itable_unused_count(struct super_block *sb,
356 			      struct ext4_group_desc *bg)
357 {
358 	return le16_to_cpu(bg->bg_itable_unused_lo) |
359 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
360 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
361 }
362 
363 void ext4_block_bitmap_set(struct super_block *sb,
364 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
365 {
366 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
367 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
368 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
369 }
370 
371 void ext4_inode_bitmap_set(struct super_block *sb,
372 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
373 {
374 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
375 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
376 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
377 }
378 
379 void ext4_inode_table_set(struct super_block *sb,
380 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
381 {
382 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
383 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
384 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
385 }
386 
387 void ext4_free_group_clusters_set(struct super_block *sb,
388 				  struct ext4_group_desc *bg, __u32 count)
389 {
390 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
391 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
392 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
393 }
394 
395 void ext4_free_inodes_set(struct super_block *sb,
396 			  struct ext4_group_desc *bg, __u32 count)
397 {
398 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
399 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
400 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
401 }
402 
403 void ext4_used_dirs_set(struct super_block *sb,
404 			  struct ext4_group_desc *bg, __u32 count)
405 {
406 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
407 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
408 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
409 }
410 
411 void ext4_itable_unused_set(struct super_block *sb,
412 			  struct ext4_group_desc *bg, __u32 count)
413 {
414 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
415 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
416 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
417 }
418 
419 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
420 {
421 	now = clamp_val(now, 0, (1ull << 40) - 1);
422 
423 	*lo = cpu_to_le32(lower_32_bits(now));
424 	*hi = upper_32_bits(now);
425 }
426 
427 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
428 {
429 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
430 }
431 #define ext4_update_tstamp(es, tstamp) \
432 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
433 			     ktime_get_real_seconds())
434 #define ext4_get_tstamp(es, tstamp) \
435 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
436 
437 #define EXT4_SB_REFRESH_INTERVAL_SEC (3600) /* seconds (1 hour) */
438 #define EXT4_SB_REFRESH_INTERVAL_KB (16384) /* kilobytes (16MB) */
439 
440 /*
441  * The ext4_maybe_update_superblock() function checks and updates the
442  * superblock if needed.
443  *
444  * This function is designed to update the on-disk superblock only under
445  * certain conditions to prevent excessive disk writes and unnecessary
446  * waking of the disk from sleep. The superblock will be updated if:
447  * 1. More than an hour has passed since the last superblock update, and
448  * 2. More than 16MB have been written since the last superblock update.
449  *
450  * @sb: The superblock
451  */
452 static void ext4_maybe_update_superblock(struct super_block *sb)
453 {
454 	struct ext4_sb_info *sbi = EXT4_SB(sb);
455 	struct ext4_super_block *es = sbi->s_es;
456 	journal_t *journal = sbi->s_journal;
457 	time64_t now;
458 	__u64 last_update;
459 	__u64 lifetime_write_kbytes;
460 	__u64 diff_size;
461 
462 	if (sb_rdonly(sb) || !(sb->s_flags & SB_ACTIVE) ||
463 	    !journal || (journal->j_flags & JBD2_UNMOUNT))
464 		return;
465 
466 	now = ktime_get_real_seconds();
467 	last_update = ext4_get_tstamp(es, s_wtime);
468 
469 	if (likely(now - last_update < EXT4_SB_REFRESH_INTERVAL_SEC))
470 		return;
471 
472 	lifetime_write_kbytes = sbi->s_kbytes_written +
473 		((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
474 		  sbi->s_sectors_written_start) >> 1);
475 
476 	/* Get the number of kilobytes not written to disk to account
477 	 * for statistics and compare with a multiple of 16 MB. This
478 	 * is used to determine when the next superblock commit should
479 	 * occur (i.e. not more often than once per 16MB if there was
480 	 * less written in an hour).
481 	 */
482 	diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written);
483 
484 	if (diff_size > EXT4_SB_REFRESH_INTERVAL_KB)
485 		schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
486 }
487 
488 /*
489  * The del_gendisk() function uninitializes the disk-specific data
490  * structures, including the bdi structure, without telling anyone
491  * else.  Once this happens, any attempt to call mark_buffer_dirty()
492  * (for example, by ext4_commit_super), will cause a kernel OOPS.
493  * This is a kludge to prevent these oops until we can put in a proper
494  * hook in del_gendisk() to inform the VFS and file system layers.
495  */
496 static int block_device_ejected(struct super_block *sb)
497 {
498 	struct inode *bd_inode = sb->s_bdev->bd_inode;
499 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
500 
501 	return bdi->dev == NULL;
502 }
503 
504 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
505 {
506 	struct super_block		*sb = journal->j_private;
507 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
508 	int				error = is_journal_aborted(journal);
509 	struct ext4_journal_cb_entry	*jce;
510 
511 	BUG_ON(txn->t_state == T_FINISHED);
512 
513 	ext4_process_freed_data(sb, txn->t_tid);
514 	ext4_maybe_update_superblock(sb);
515 
516 	spin_lock(&sbi->s_md_lock);
517 	while (!list_empty(&txn->t_private_list)) {
518 		jce = list_entry(txn->t_private_list.next,
519 				 struct ext4_journal_cb_entry, jce_list);
520 		list_del_init(&jce->jce_list);
521 		spin_unlock(&sbi->s_md_lock);
522 		jce->jce_func(sb, jce, error);
523 		spin_lock(&sbi->s_md_lock);
524 	}
525 	spin_unlock(&sbi->s_md_lock);
526 }
527 
528 /*
529  * This writepage callback for write_cache_pages()
530  * takes care of a few cases after page cleaning.
531  *
532  * write_cache_pages() already checks for dirty pages
533  * and calls clear_page_dirty_for_io(), which we want,
534  * to write protect the pages.
535  *
536  * However, we may have to redirty a page (see below.)
537  */
538 static int ext4_journalled_writepage_callback(struct folio *folio,
539 					      struct writeback_control *wbc,
540 					      void *data)
541 {
542 	transaction_t *transaction = (transaction_t *) data;
543 	struct buffer_head *bh, *head;
544 	struct journal_head *jh;
545 
546 	bh = head = folio_buffers(folio);
547 	do {
548 		/*
549 		 * We have to redirty a page in these cases:
550 		 * 1) If buffer is dirty, it means the page was dirty because it
551 		 * contains a buffer that needs checkpointing. So the dirty bit
552 		 * needs to be preserved so that checkpointing writes the buffer
553 		 * properly.
554 		 * 2) If buffer is not part of the committing transaction
555 		 * (we may have just accidentally come across this buffer because
556 		 * inode range tracking is not exact) or if the currently running
557 		 * transaction already contains this buffer as well, dirty bit
558 		 * needs to be preserved so that the buffer gets writeprotected
559 		 * properly on running transaction's commit.
560 		 */
561 		jh = bh2jh(bh);
562 		if (buffer_dirty(bh) ||
563 		    (jh && (jh->b_transaction != transaction ||
564 			    jh->b_next_transaction))) {
565 			folio_redirty_for_writepage(wbc, folio);
566 			goto out;
567 		}
568 	} while ((bh = bh->b_this_page) != head);
569 
570 out:
571 	return AOP_WRITEPAGE_ACTIVATE;
572 }
573 
574 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
575 {
576 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
577 	struct writeback_control wbc = {
578 		.sync_mode =  WB_SYNC_ALL,
579 		.nr_to_write = LONG_MAX,
580 		.range_start = jinode->i_dirty_start,
581 		.range_end = jinode->i_dirty_end,
582         };
583 
584 	return write_cache_pages(mapping, &wbc,
585 				 ext4_journalled_writepage_callback,
586 				 jinode->i_transaction);
587 }
588 
589 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
590 {
591 	int ret;
592 
593 	if (ext4_should_journal_data(jinode->i_vfs_inode))
594 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
595 	else
596 		ret = ext4_normal_submit_inode_data_buffers(jinode);
597 	return ret;
598 }
599 
600 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
601 {
602 	int ret = 0;
603 
604 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
605 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
606 
607 	return ret;
608 }
609 
610 static bool system_going_down(void)
611 {
612 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
613 		|| system_state == SYSTEM_RESTART;
614 }
615 
616 struct ext4_err_translation {
617 	int code;
618 	int errno;
619 };
620 
621 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
622 
623 static struct ext4_err_translation err_translation[] = {
624 	EXT4_ERR_TRANSLATE(EIO),
625 	EXT4_ERR_TRANSLATE(ENOMEM),
626 	EXT4_ERR_TRANSLATE(EFSBADCRC),
627 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
628 	EXT4_ERR_TRANSLATE(ENOSPC),
629 	EXT4_ERR_TRANSLATE(ENOKEY),
630 	EXT4_ERR_TRANSLATE(EROFS),
631 	EXT4_ERR_TRANSLATE(EFBIG),
632 	EXT4_ERR_TRANSLATE(EEXIST),
633 	EXT4_ERR_TRANSLATE(ERANGE),
634 	EXT4_ERR_TRANSLATE(EOVERFLOW),
635 	EXT4_ERR_TRANSLATE(EBUSY),
636 	EXT4_ERR_TRANSLATE(ENOTDIR),
637 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
638 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
639 	EXT4_ERR_TRANSLATE(EFAULT),
640 };
641 
642 static int ext4_errno_to_code(int errno)
643 {
644 	int i;
645 
646 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
647 		if (err_translation[i].errno == errno)
648 			return err_translation[i].code;
649 	return EXT4_ERR_UNKNOWN;
650 }
651 
652 static void save_error_info(struct super_block *sb, int error,
653 			    __u32 ino, __u64 block,
654 			    const char *func, unsigned int line)
655 {
656 	struct ext4_sb_info *sbi = EXT4_SB(sb);
657 
658 	/* We default to EFSCORRUPTED error... */
659 	if (error == 0)
660 		error = EFSCORRUPTED;
661 
662 	spin_lock(&sbi->s_error_lock);
663 	sbi->s_add_error_count++;
664 	sbi->s_last_error_code = error;
665 	sbi->s_last_error_line = line;
666 	sbi->s_last_error_ino = ino;
667 	sbi->s_last_error_block = block;
668 	sbi->s_last_error_func = func;
669 	sbi->s_last_error_time = ktime_get_real_seconds();
670 	if (!sbi->s_first_error_time) {
671 		sbi->s_first_error_code = error;
672 		sbi->s_first_error_line = line;
673 		sbi->s_first_error_ino = ino;
674 		sbi->s_first_error_block = block;
675 		sbi->s_first_error_func = func;
676 		sbi->s_first_error_time = sbi->s_last_error_time;
677 	}
678 	spin_unlock(&sbi->s_error_lock);
679 }
680 
681 /* Deal with the reporting of failure conditions on a filesystem such as
682  * inconsistencies detected or read IO failures.
683  *
684  * On ext2, we can store the error state of the filesystem in the
685  * superblock.  That is not possible on ext4, because we may have other
686  * write ordering constraints on the superblock which prevent us from
687  * writing it out straight away; and given that the journal is about to
688  * be aborted, we can't rely on the current, or future, transactions to
689  * write out the superblock safely.
690  *
691  * We'll just use the jbd2_journal_abort() error code to record an error in
692  * the journal instead.  On recovery, the journal will complain about
693  * that error until we've noted it down and cleared it.
694  *
695  * If force_ro is set, we unconditionally force the filesystem into an
696  * ABORT|READONLY state, unless the error response on the fs has been set to
697  * panic in which case we take the easy way out and panic immediately. This is
698  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
699  * at a critical moment in log management.
700  */
701 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
702 			      __u32 ino, __u64 block,
703 			      const char *func, unsigned int line)
704 {
705 	journal_t *journal = EXT4_SB(sb)->s_journal;
706 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
707 
708 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
709 	if (test_opt(sb, WARN_ON_ERROR))
710 		WARN_ON_ONCE(1);
711 
712 	if (!continue_fs && !sb_rdonly(sb)) {
713 		set_bit(EXT4_FLAGS_SHUTDOWN, &EXT4_SB(sb)->s_ext4_flags);
714 		if (journal)
715 			jbd2_journal_abort(journal, -EIO);
716 	}
717 
718 	if (!bdev_read_only(sb->s_bdev)) {
719 		save_error_info(sb, error, ino, block, func, line);
720 		/*
721 		 * In case the fs should keep running, we need to writeout
722 		 * superblock through the journal. Due to lock ordering
723 		 * constraints, it may not be safe to do it right here so we
724 		 * defer superblock flushing to a workqueue.
725 		 */
726 		if (continue_fs && journal)
727 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
728 		else
729 			ext4_commit_super(sb);
730 	}
731 
732 	/*
733 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
734 	 * could panic during 'reboot -f' as the underlying device got already
735 	 * disabled.
736 	 */
737 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
738 		panic("EXT4-fs (device %s): panic forced after error\n",
739 			sb->s_id);
740 	}
741 
742 	if (sb_rdonly(sb) || continue_fs)
743 		return;
744 
745 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
746 	/*
747 	 * Make sure updated value of ->s_mount_flags will be visible before
748 	 * ->s_flags update
749 	 */
750 	smp_wmb();
751 	sb->s_flags |= SB_RDONLY;
752 }
753 
754 static void update_super_work(struct work_struct *work)
755 {
756 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
757 						s_sb_upd_work);
758 	journal_t *journal = sbi->s_journal;
759 	handle_t *handle;
760 
761 	/*
762 	 * If the journal is still running, we have to write out superblock
763 	 * through the journal to avoid collisions of other journalled sb
764 	 * updates.
765 	 *
766 	 * We use directly jbd2 functions here to avoid recursing back into
767 	 * ext4 error handling code during handling of previous errors.
768 	 */
769 	if (!sb_rdonly(sbi->s_sb) && journal) {
770 		struct buffer_head *sbh = sbi->s_sbh;
771 		bool call_notify_err = false;
772 
773 		handle = jbd2_journal_start(journal, 1);
774 		if (IS_ERR(handle))
775 			goto write_directly;
776 		if (jbd2_journal_get_write_access(handle, sbh)) {
777 			jbd2_journal_stop(handle);
778 			goto write_directly;
779 		}
780 
781 		if (sbi->s_add_error_count > 0)
782 			call_notify_err = true;
783 
784 		ext4_update_super(sbi->s_sb);
785 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
786 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
787 				 "superblock detected");
788 			clear_buffer_write_io_error(sbh);
789 			set_buffer_uptodate(sbh);
790 		}
791 
792 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
793 			jbd2_journal_stop(handle);
794 			goto write_directly;
795 		}
796 		jbd2_journal_stop(handle);
797 
798 		if (call_notify_err)
799 			ext4_notify_error_sysfs(sbi);
800 
801 		return;
802 	}
803 write_directly:
804 	/*
805 	 * Write through journal failed. Write sb directly to get error info
806 	 * out and hope for the best.
807 	 */
808 	ext4_commit_super(sbi->s_sb);
809 	ext4_notify_error_sysfs(sbi);
810 }
811 
812 #define ext4_error_ratelimit(sb)					\
813 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
814 			     "EXT4-fs error")
815 
816 void __ext4_error(struct super_block *sb, const char *function,
817 		  unsigned int line, bool force_ro, int error, __u64 block,
818 		  const char *fmt, ...)
819 {
820 	struct va_format vaf;
821 	va_list args;
822 
823 	if (unlikely(ext4_forced_shutdown(sb)))
824 		return;
825 
826 	trace_ext4_error(sb, function, line);
827 	if (ext4_error_ratelimit(sb)) {
828 		va_start(args, fmt);
829 		vaf.fmt = fmt;
830 		vaf.va = &args;
831 		printk(KERN_CRIT
832 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
833 		       sb->s_id, function, line, current->comm, &vaf);
834 		va_end(args);
835 	}
836 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
837 
838 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
839 }
840 
841 void __ext4_error_inode(struct inode *inode, const char *function,
842 			unsigned int line, ext4_fsblk_t block, int error,
843 			const char *fmt, ...)
844 {
845 	va_list args;
846 	struct va_format vaf;
847 
848 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
849 		return;
850 
851 	trace_ext4_error(inode->i_sb, function, line);
852 	if (ext4_error_ratelimit(inode->i_sb)) {
853 		va_start(args, fmt);
854 		vaf.fmt = fmt;
855 		vaf.va = &args;
856 		if (block)
857 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
858 			       "inode #%lu: block %llu: comm %s: %pV\n",
859 			       inode->i_sb->s_id, function, line, inode->i_ino,
860 			       block, current->comm, &vaf);
861 		else
862 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
863 			       "inode #%lu: comm %s: %pV\n",
864 			       inode->i_sb->s_id, function, line, inode->i_ino,
865 			       current->comm, &vaf);
866 		va_end(args);
867 	}
868 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
869 
870 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
871 			  function, line);
872 }
873 
874 void __ext4_error_file(struct file *file, const char *function,
875 		       unsigned int line, ext4_fsblk_t block,
876 		       const char *fmt, ...)
877 {
878 	va_list args;
879 	struct va_format vaf;
880 	struct inode *inode = file_inode(file);
881 	char pathname[80], *path;
882 
883 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
884 		return;
885 
886 	trace_ext4_error(inode->i_sb, function, line);
887 	if (ext4_error_ratelimit(inode->i_sb)) {
888 		path = file_path(file, pathname, sizeof(pathname));
889 		if (IS_ERR(path))
890 			path = "(unknown)";
891 		va_start(args, fmt);
892 		vaf.fmt = fmt;
893 		vaf.va = &args;
894 		if (block)
895 			printk(KERN_CRIT
896 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
897 			       "block %llu: comm %s: path %s: %pV\n",
898 			       inode->i_sb->s_id, function, line, inode->i_ino,
899 			       block, current->comm, path, &vaf);
900 		else
901 			printk(KERN_CRIT
902 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
903 			       "comm %s: path %s: %pV\n",
904 			       inode->i_sb->s_id, function, line, inode->i_ino,
905 			       current->comm, path, &vaf);
906 		va_end(args);
907 	}
908 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
909 
910 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
911 			  function, line);
912 }
913 
914 const char *ext4_decode_error(struct super_block *sb, int errno,
915 			      char nbuf[16])
916 {
917 	char *errstr = NULL;
918 
919 	switch (errno) {
920 	case -EFSCORRUPTED:
921 		errstr = "Corrupt filesystem";
922 		break;
923 	case -EFSBADCRC:
924 		errstr = "Filesystem failed CRC";
925 		break;
926 	case -EIO:
927 		errstr = "IO failure";
928 		break;
929 	case -ENOMEM:
930 		errstr = "Out of memory";
931 		break;
932 	case -EROFS:
933 		if (!sb || (EXT4_SB(sb)->s_journal &&
934 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
935 			errstr = "Journal has aborted";
936 		else
937 			errstr = "Readonly filesystem";
938 		break;
939 	default:
940 		/* If the caller passed in an extra buffer for unknown
941 		 * errors, textualise them now.  Else we just return
942 		 * NULL. */
943 		if (nbuf) {
944 			/* Check for truncated error codes... */
945 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
946 				errstr = nbuf;
947 		}
948 		break;
949 	}
950 
951 	return errstr;
952 }
953 
954 /* __ext4_std_error decodes expected errors from journaling functions
955  * automatically and invokes the appropriate error response.  */
956 
957 void __ext4_std_error(struct super_block *sb, const char *function,
958 		      unsigned int line, int errno)
959 {
960 	char nbuf[16];
961 	const char *errstr;
962 
963 	if (unlikely(ext4_forced_shutdown(sb)))
964 		return;
965 
966 	/* Special case: if the error is EROFS, and we're not already
967 	 * inside a transaction, then there's really no point in logging
968 	 * an error. */
969 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
970 		return;
971 
972 	if (ext4_error_ratelimit(sb)) {
973 		errstr = ext4_decode_error(sb, errno, nbuf);
974 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
975 		       sb->s_id, function, line, errstr);
976 	}
977 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
978 
979 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
980 }
981 
982 void __ext4_msg(struct super_block *sb,
983 		const char *prefix, const char *fmt, ...)
984 {
985 	struct va_format vaf;
986 	va_list args;
987 
988 	if (sb) {
989 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
990 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
991 				  "EXT4-fs"))
992 			return;
993 	}
994 
995 	va_start(args, fmt);
996 	vaf.fmt = fmt;
997 	vaf.va = &args;
998 	if (sb)
999 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
1000 	else
1001 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
1002 	va_end(args);
1003 }
1004 
1005 static int ext4_warning_ratelimit(struct super_block *sb)
1006 {
1007 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
1008 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1009 			    "EXT4-fs warning");
1010 }
1011 
1012 void __ext4_warning(struct super_block *sb, const char *function,
1013 		    unsigned int line, const char *fmt, ...)
1014 {
1015 	struct va_format vaf;
1016 	va_list args;
1017 
1018 	if (!ext4_warning_ratelimit(sb))
1019 		return;
1020 
1021 	va_start(args, fmt);
1022 	vaf.fmt = fmt;
1023 	vaf.va = &args;
1024 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1025 	       sb->s_id, function, line, &vaf);
1026 	va_end(args);
1027 }
1028 
1029 void __ext4_warning_inode(const struct inode *inode, const char *function,
1030 			  unsigned int line, const char *fmt, ...)
1031 {
1032 	struct va_format vaf;
1033 	va_list args;
1034 
1035 	if (!ext4_warning_ratelimit(inode->i_sb))
1036 		return;
1037 
1038 	va_start(args, fmt);
1039 	vaf.fmt = fmt;
1040 	vaf.va = &args;
1041 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1042 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
1043 	       function, line, inode->i_ino, current->comm, &vaf);
1044 	va_end(args);
1045 }
1046 
1047 void __ext4_grp_locked_error(const char *function, unsigned int line,
1048 			     struct super_block *sb, ext4_group_t grp,
1049 			     unsigned long ino, ext4_fsblk_t block,
1050 			     const char *fmt, ...)
1051 __releases(bitlock)
1052 __acquires(bitlock)
1053 {
1054 	struct va_format vaf;
1055 	va_list args;
1056 
1057 	if (unlikely(ext4_forced_shutdown(sb)))
1058 		return;
1059 
1060 	trace_ext4_error(sb, function, line);
1061 	if (ext4_error_ratelimit(sb)) {
1062 		va_start(args, fmt);
1063 		vaf.fmt = fmt;
1064 		vaf.va = &args;
1065 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1066 		       sb->s_id, function, line, grp);
1067 		if (ino)
1068 			printk(KERN_CONT "inode %lu: ", ino);
1069 		if (block)
1070 			printk(KERN_CONT "block %llu:",
1071 			       (unsigned long long) block);
1072 		printk(KERN_CONT "%pV\n", &vaf);
1073 		va_end(args);
1074 	}
1075 
1076 	if (test_opt(sb, ERRORS_CONT)) {
1077 		if (test_opt(sb, WARN_ON_ERROR))
1078 			WARN_ON_ONCE(1);
1079 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1080 		if (!bdev_read_only(sb->s_bdev)) {
1081 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1082 					line);
1083 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1084 		}
1085 		return;
1086 	}
1087 	ext4_unlock_group(sb, grp);
1088 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1089 	/*
1090 	 * We only get here in the ERRORS_RO case; relocking the group
1091 	 * may be dangerous, but nothing bad will happen since the
1092 	 * filesystem will have already been marked read/only and the
1093 	 * journal has been aborted.  We return 1 as a hint to callers
1094 	 * who might what to use the return value from
1095 	 * ext4_grp_locked_error() to distinguish between the
1096 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1097 	 * aggressively from the ext4 function in question, with a
1098 	 * more appropriate error code.
1099 	 */
1100 	ext4_lock_group(sb, grp);
1101 	return;
1102 }
1103 
1104 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1105 				     ext4_group_t group,
1106 				     unsigned int flags)
1107 {
1108 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1109 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1110 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1111 	int ret;
1112 
1113 	if (!grp || !gdp)
1114 		return;
1115 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1116 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1117 					    &grp->bb_state);
1118 		if (!ret)
1119 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1120 					   grp->bb_free);
1121 	}
1122 
1123 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1124 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1125 					    &grp->bb_state);
1126 		if (!ret && gdp) {
1127 			int count;
1128 
1129 			count = ext4_free_inodes_count(sb, gdp);
1130 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1131 					   count);
1132 		}
1133 	}
1134 }
1135 
1136 void ext4_update_dynamic_rev(struct super_block *sb)
1137 {
1138 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1139 
1140 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1141 		return;
1142 
1143 	ext4_warning(sb,
1144 		     "updating to rev %d because of new feature flag, "
1145 		     "running e2fsck is recommended",
1146 		     EXT4_DYNAMIC_REV);
1147 
1148 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1149 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1150 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1151 	/* leave es->s_feature_*compat flags alone */
1152 	/* es->s_uuid will be set by e2fsck if empty */
1153 
1154 	/*
1155 	 * The rest of the superblock fields should be zero, and if not it
1156 	 * means they are likely already in use, so leave them alone.  We
1157 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1158 	 */
1159 }
1160 
1161 static inline struct inode *orphan_list_entry(struct list_head *l)
1162 {
1163 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1164 }
1165 
1166 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1167 {
1168 	struct list_head *l;
1169 
1170 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1171 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1172 
1173 	printk(KERN_ERR "sb_info orphan list:\n");
1174 	list_for_each(l, &sbi->s_orphan) {
1175 		struct inode *inode = orphan_list_entry(l);
1176 		printk(KERN_ERR "  "
1177 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1178 		       inode->i_sb->s_id, inode->i_ino, inode,
1179 		       inode->i_mode, inode->i_nlink,
1180 		       NEXT_ORPHAN(inode));
1181 	}
1182 }
1183 
1184 #ifdef CONFIG_QUOTA
1185 static int ext4_quota_off(struct super_block *sb, int type);
1186 
1187 static inline void ext4_quotas_off(struct super_block *sb, int type)
1188 {
1189 	BUG_ON(type > EXT4_MAXQUOTAS);
1190 
1191 	/* Use our quota_off function to clear inode flags etc. */
1192 	for (type--; type >= 0; type--)
1193 		ext4_quota_off(sb, type);
1194 }
1195 
1196 /*
1197  * This is a helper function which is used in the mount/remount
1198  * codepaths (which holds s_umount) to fetch the quota file name.
1199  */
1200 static inline char *get_qf_name(struct super_block *sb,
1201 				struct ext4_sb_info *sbi,
1202 				int type)
1203 {
1204 	return rcu_dereference_protected(sbi->s_qf_names[type],
1205 					 lockdep_is_held(&sb->s_umount));
1206 }
1207 #else
1208 static inline void ext4_quotas_off(struct super_block *sb, int type)
1209 {
1210 }
1211 #endif
1212 
1213 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1214 {
1215 	ext4_fsblk_t block;
1216 	int err;
1217 
1218 	block = ext4_count_free_clusters(sbi->s_sb);
1219 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1220 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1221 				  GFP_KERNEL);
1222 	if (!err) {
1223 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1224 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1225 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1226 					  GFP_KERNEL);
1227 	}
1228 	if (!err)
1229 		err = percpu_counter_init(&sbi->s_dirs_counter,
1230 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1231 	if (!err)
1232 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1233 					  GFP_KERNEL);
1234 	if (!err)
1235 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1236 					  GFP_KERNEL);
1237 	if (!err)
1238 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1239 
1240 	if (err)
1241 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1242 
1243 	return err;
1244 }
1245 
1246 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1247 {
1248 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1249 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1250 	percpu_counter_destroy(&sbi->s_dirs_counter);
1251 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1252 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1253 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1254 }
1255 
1256 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1257 {
1258 	struct buffer_head **group_desc;
1259 	int i;
1260 
1261 	rcu_read_lock();
1262 	group_desc = rcu_dereference(sbi->s_group_desc);
1263 	for (i = 0; i < sbi->s_gdb_count; i++)
1264 		brelse(group_desc[i]);
1265 	kvfree(group_desc);
1266 	rcu_read_unlock();
1267 }
1268 
1269 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1270 {
1271 	struct flex_groups **flex_groups;
1272 	int i;
1273 
1274 	rcu_read_lock();
1275 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1276 	if (flex_groups) {
1277 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1278 			kvfree(flex_groups[i]);
1279 		kvfree(flex_groups);
1280 	}
1281 	rcu_read_unlock();
1282 }
1283 
1284 static void ext4_put_super(struct super_block *sb)
1285 {
1286 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1287 	struct ext4_super_block *es = sbi->s_es;
1288 	int aborted = 0;
1289 	int err;
1290 
1291 	/*
1292 	 * Unregister sysfs before destroying jbd2 journal.
1293 	 * Since we could still access attr_journal_task attribute via sysfs
1294 	 * path which could have sbi->s_journal->j_task as NULL
1295 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1296 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1297 	 * read metadata verify failed then will queue error work.
1298 	 * update_super_work will call start_this_handle may trigger
1299 	 * BUG_ON.
1300 	 */
1301 	ext4_unregister_sysfs(sb);
1302 
1303 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1304 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1305 			 &sb->s_uuid);
1306 
1307 	ext4_unregister_li_request(sb);
1308 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1309 
1310 	flush_work(&sbi->s_sb_upd_work);
1311 	destroy_workqueue(sbi->rsv_conversion_wq);
1312 	ext4_release_orphan_info(sb);
1313 
1314 	if (sbi->s_journal) {
1315 		aborted = is_journal_aborted(sbi->s_journal);
1316 		err = jbd2_journal_destroy(sbi->s_journal);
1317 		sbi->s_journal = NULL;
1318 		if ((err < 0) && !aborted) {
1319 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1320 		}
1321 	}
1322 
1323 	ext4_es_unregister_shrinker(sbi);
1324 	timer_shutdown_sync(&sbi->s_err_report);
1325 	ext4_release_system_zone(sb);
1326 	ext4_mb_release(sb);
1327 	ext4_ext_release(sb);
1328 
1329 	if (!sb_rdonly(sb) && !aborted) {
1330 		ext4_clear_feature_journal_needs_recovery(sb);
1331 		ext4_clear_feature_orphan_present(sb);
1332 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1333 	}
1334 	if (!sb_rdonly(sb))
1335 		ext4_commit_super(sb);
1336 
1337 	ext4_group_desc_free(sbi);
1338 	ext4_flex_groups_free(sbi);
1339 	ext4_percpu_param_destroy(sbi);
1340 #ifdef CONFIG_QUOTA
1341 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1342 		kfree(get_qf_name(sb, sbi, i));
1343 #endif
1344 
1345 	/* Debugging code just in case the in-memory inode orphan list
1346 	 * isn't empty.  The on-disk one can be non-empty if we've
1347 	 * detected an error and taken the fs readonly, but the
1348 	 * in-memory list had better be clean by this point. */
1349 	if (!list_empty(&sbi->s_orphan))
1350 		dump_orphan_list(sb, sbi);
1351 	ASSERT(list_empty(&sbi->s_orphan));
1352 
1353 	sync_blockdev(sb->s_bdev);
1354 	invalidate_bdev(sb->s_bdev);
1355 	if (sbi->s_journal_bdev) {
1356 		/*
1357 		 * Invalidate the journal device's buffers.  We don't want them
1358 		 * floating about in memory - the physical journal device may
1359 		 * hotswapped, and it breaks the `ro-after' testing code.
1360 		 */
1361 		sync_blockdev(sbi->s_journal_bdev);
1362 		invalidate_bdev(sbi->s_journal_bdev);
1363 	}
1364 
1365 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1366 	sbi->s_ea_inode_cache = NULL;
1367 
1368 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1369 	sbi->s_ea_block_cache = NULL;
1370 
1371 	ext4_stop_mmpd(sbi);
1372 
1373 	brelse(sbi->s_sbh);
1374 	sb->s_fs_info = NULL;
1375 	/*
1376 	 * Now that we are completely done shutting down the
1377 	 * superblock, we need to actually destroy the kobject.
1378 	 */
1379 	kobject_put(&sbi->s_kobj);
1380 	wait_for_completion(&sbi->s_kobj_unregister);
1381 	if (sbi->s_chksum_driver)
1382 		crypto_free_shash(sbi->s_chksum_driver);
1383 	kfree(sbi->s_blockgroup_lock);
1384 	fs_put_dax(sbi->s_daxdev, NULL);
1385 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1386 #if IS_ENABLED(CONFIG_UNICODE)
1387 	utf8_unload(sb->s_encoding);
1388 #endif
1389 	kfree(sbi);
1390 }
1391 
1392 static struct kmem_cache *ext4_inode_cachep;
1393 
1394 /*
1395  * Called inside transaction, so use GFP_NOFS
1396  */
1397 static struct inode *ext4_alloc_inode(struct super_block *sb)
1398 {
1399 	struct ext4_inode_info *ei;
1400 
1401 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1402 	if (!ei)
1403 		return NULL;
1404 
1405 	inode_set_iversion(&ei->vfs_inode, 1);
1406 	ei->i_flags = 0;
1407 	spin_lock_init(&ei->i_raw_lock);
1408 	ei->i_prealloc_node = RB_ROOT;
1409 	atomic_set(&ei->i_prealloc_active, 0);
1410 	rwlock_init(&ei->i_prealloc_lock);
1411 	ext4_es_init_tree(&ei->i_es_tree);
1412 	rwlock_init(&ei->i_es_lock);
1413 	INIT_LIST_HEAD(&ei->i_es_list);
1414 	ei->i_es_all_nr = 0;
1415 	ei->i_es_shk_nr = 0;
1416 	ei->i_es_shrink_lblk = 0;
1417 	ei->i_reserved_data_blocks = 0;
1418 	spin_lock_init(&(ei->i_block_reservation_lock));
1419 	ext4_init_pending_tree(&ei->i_pending_tree);
1420 #ifdef CONFIG_QUOTA
1421 	ei->i_reserved_quota = 0;
1422 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1423 #endif
1424 	ei->jinode = NULL;
1425 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1426 	spin_lock_init(&ei->i_completed_io_lock);
1427 	ei->i_sync_tid = 0;
1428 	ei->i_datasync_tid = 0;
1429 	atomic_set(&ei->i_unwritten, 0);
1430 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1431 	ext4_fc_init_inode(&ei->vfs_inode);
1432 	mutex_init(&ei->i_fc_lock);
1433 	return &ei->vfs_inode;
1434 }
1435 
1436 static int ext4_drop_inode(struct inode *inode)
1437 {
1438 	int drop = generic_drop_inode(inode);
1439 
1440 	if (!drop)
1441 		drop = fscrypt_drop_inode(inode);
1442 
1443 	trace_ext4_drop_inode(inode, drop);
1444 	return drop;
1445 }
1446 
1447 static void ext4_free_in_core_inode(struct inode *inode)
1448 {
1449 	fscrypt_free_inode(inode);
1450 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1451 		pr_warn("%s: inode %ld still in fc list",
1452 			__func__, inode->i_ino);
1453 	}
1454 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1455 }
1456 
1457 static void ext4_destroy_inode(struct inode *inode)
1458 {
1459 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1460 		ext4_msg(inode->i_sb, KERN_ERR,
1461 			 "Inode %lu (%p): orphan list check failed!",
1462 			 inode->i_ino, EXT4_I(inode));
1463 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1464 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1465 				true);
1466 		dump_stack();
1467 	}
1468 
1469 	if (EXT4_I(inode)->i_reserved_data_blocks)
1470 		ext4_msg(inode->i_sb, KERN_ERR,
1471 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1472 			 inode->i_ino, EXT4_I(inode),
1473 			 EXT4_I(inode)->i_reserved_data_blocks);
1474 }
1475 
1476 static void ext4_shutdown(struct super_block *sb)
1477 {
1478        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1479 }
1480 
1481 static void init_once(void *foo)
1482 {
1483 	struct ext4_inode_info *ei = foo;
1484 
1485 	INIT_LIST_HEAD(&ei->i_orphan);
1486 	init_rwsem(&ei->xattr_sem);
1487 	init_rwsem(&ei->i_data_sem);
1488 	inode_init_once(&ei->vfs_inode);
1489 	ext4_fc_init_inode(&ei->vfs_inode);
1490 }
1491 
1492 static int __init init_inodecache(void)
1493 {
1494 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1495 				sizeof(struct ext4_inode_info), 0,
1496 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1497 					SLAB_ACCOUNT),
1498 				offsetof(struct ext4_inode_info, i_data),
1499 				sizeof_field(struct ext4_inode_info, i_data),
1500 				init_once);
1501 	if (ext4_inode_cachep == NULL)
1502 		return -ENOMEM;
1503 	return 0;
1504 }
1505 
1506 static void destroy_inodecache(void)
1507 {
1508 	/*
1509 	 * Make sure all delayed rcu free inodes are flushed before we
1510 	 * destroy cache.
1511 	 */
1512 	rcu_barrier();
1513 	kmem_cache_destroy(ext4_inode_cachep);
1514 }
1515 
1516 void ext4_clear_inode(struct inode *inode)
1517 {
1518 	ext4_fc_del(inode);
1519 	invalidate_inode_buffers(inode);
1520 	clear_inode(inode);
1521 	ext4_discard_preallocations(inode, 0);
1522 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1523 	dquot_drop(inode);
1524 	if (EXT4_I(inode)->jinode) {
1525 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1526 					       EXT4_I(inode)->jinode);
1527 		jbd2_free_inode(EXT4_I(inode)->jinode);
1528 		EXT4_I(inode)->jinode = NULL;
1529 	}
1530 	fscrypt_put_encryption_info(inode);
1531 	fsverity_cleanup_inode(inode);
1532 }
1533 
1534 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1535 					u64 ino, u32 generation)
1536 {
1537 	struct inode *inode;
1538 
1539 	/*
1540 	 * Currently we don't know the generation for parent directory, so
1541 	 * a generation of 0 means "accept any"
1542 	 */
1543 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1544 	if (IS_ERR(inode))
1545 		return ERR_CAST(inode);
1546 	if (generation && inode->i_generation != generation) {
1547 		iput(inode);
1548 		return ERR_PTR(-ESTALE);
1549 	}
1550 
1551 	return inode;
1552 }
1553 
1554 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1555 					int fh_len, int fh_type)
1556 {
1557 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1558 				    ext4_nfs_get_inode);
1559 }
1560 
1561 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1562 					int fh_len, int fh_type)
1563 {
1564 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1565 				    ext4_nfs_get_inode);
1566 }
1567 
1568 static int ext4_nfs_commit_metadata(struct inode *inode)
1569 {
1570 	struct writeback_control wbc = {
1571 		.sync_mode = WB_SYNC_ALL
1572 	};
1573 
1574 	trace_ext4_nfs_commit_metadata(inode);
1575 	return ext4_write_inode(inode, &wbc);
1576 }
1577 
1578 #ifdef CONFIG_QUOTA
1579 static const char * const quotatypes[] = INITQFNAMES;
1580 #define QTYPE2NAME(t) (quotatypes[t])
1581 
1582 static int ext4_write_dquot(struct dquot *dquot);
1583 static int ext4_acquire_dquot(struct dquot *dquot);
1584 static int ext4_release_dquot(struct dquot *dquot);
1585 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1586 static int ext4_write_info(struct super_block *sb, int type);
1587 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1588 			 const struct path *path);
1589 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1590 			       size_t len, loff_t off);
1591 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1592 				const char *data, size_t len, loff_t off);
1593 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1594 			     unsigned int flags);
1595 
1596 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1597 {
1598 	return EXT4_I(inode)->i_dquot;
1599 }
1600 
1601 static const struct dquot_operations ext4_quota_operations = {
1602 	.get_reserved_space	= ext4_get_reserved_space,
1603 	.write_dquot		= ext4_write_dquot,
1604 	.acquire_dquot		= ext4_acquire_dquot,
1605 	.release_dquot		= ext4_release_dquot,
1606 	.mark_dirty		= ext4_mark_dquot_dirty,
1607 	.write_info		= ext4_write_info,
1608 	.alloc_dquot		= dquot_alloc,
1609 	.destroy_dquot		= dquot_destroy,
1610 	.get_projid		= ext4_get_projid,
1611 	.get_inode_usage	= ext4_get_inode_usage,
1612 	.get_next_id		= dquot_get_next_id,
1613 };
1614 
1615 static const struct quotactl_ops ext4_qctl_operations = {
1616 	.quota_on	= ext4_quota_on,
1617 	.quota_off	= ext4_quota_off,
1618 	.quota_sync	= dquot_quota_sync,
1619 	.get_state	= dquot_get_state,
1620 	.set_info	= dquot_set_dqinfo,
1621 	.get_dqblk	= dquot_get_dqblk,
1622 	.set_dqblk	= dquot_set_dqblk,
1623 	.get_nextdqblk	= dquot_get_next_dqblk,
1624 };
1625 #endif
1626 
1627 static const struct super_operations ext4_sops = {
1628 	.alloc_inode	= ext4_alloc_inode,
1629 	.free_inode	= ext4_free_in_core_inode,
1630 	.destroy_inode	= ext4_destroy_inode,
1631 	.write_inode	= ext4_write_inode,
1632 	.dirty_inode	= ext4_dirty_inode,
1633 	.drop_inode	= ext4_drop_inode,
1634 	.evict_inode	= ext4_evict_inode,
1635 	.put_super	= ext4_put_super,
1636 	.sync_fs	= ext4_sync_fs,
1637 	.freeze_fs	= ext4_freeze,
1638 	.unfreeze_fs	= ext4_unfreeze,
1639 	.statfs		= ext4_statfs,
1640 	.show_options	= ext4_show_options,
1641 	.shutdown	= ext4_shutdown,
1642 #ifdef CONFIG_QUOTA
1643 	.quota_read	= ext4_quota_read,
1644 	.quota_write	= ext4_quota_write,
1645 	.get_dquots	= ext4_get_dquots,
1646 #endif
1647 };
1648 
1649 static const struct export_operations ext4_export_ops = {
1650 	.fh_to_dentry = ext4_fh_to_dentry,
1651 	.fh_to_parent = ext4_fh_to_parent,
1652 	.get_parent = ext4_get_parent,
1653 	.commit_metadata = ext4_nfs_commit_metadata,
1654 };
1655 
1656 enum {
1657 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1658 	Opt_resgid, Opt_resuid, Opt_sb,
1659 	Opt_nouid32, Opt_debug, Opt_removed,
1660 	Opt_user_xattr, Opt_acl,
1661 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1662 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1663 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1664 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1665 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1666 	Opt_inlinecrypt,
1667 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1668 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1669 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1670 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1671 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1672 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1673 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1674 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1675 	Opt_dioread_nolock, Opt_dioread_lock,
1676 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1677 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1678 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1679 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1680 #ifdef CONFIG_EXT4_DEBUG
1681 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1682 #endif
1683 };
1684 
1685 static const struct constant_table ext4_param_errors[] = {
1686 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1687 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1688 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1689 	{}
1690 };
1691 
1692 static const struct constant_table ext4_param_data[] = {
1693 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1694 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1695 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1696 	{}
1697 };
1698 
1699 static const struct constant_table ext4_param_data_err[] = {
1700 	{"abort",	Opt_data_err_abort},
1701 	{"ignore",	Opt_data_err_ignore},
1702 	{}
1703 };
1704 
1705 static const struct constant_table ext4_param_jqfmt[] = {
1706 	{"vfsold",	QFMT_VFS_OLD},
1707 	{"vfsv0",	QFMT_VFS_V0},
1708 	{"vfsv1",	QFMT_VFS_V1},
1709 	{}
1710 };
1711 
1712 static const struct constant_table ext4_param_dax[] = {
1713 	{"always",	Opt_dax_always},
1714 	{"inode",	Opt_dax_inode},
1715 	{"never",	Opt_dax_never},
1716 	{}
1717 };
1718 
1719 /* String parameter that allows empty argument */
1720 #define fsparam_string_empty(NAME, OPT) \
1721 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1722 
1723 /*
1724  * Mount option specification
1725  * We don't use fsparam_flag_no because of the way we set the
1726  * options and the way we show them in _ext4_show_options(). To
1727  * keep the changes to a minimum, let's keep the negative options
1728  * separate for now.
1729  */
1730 static const struct fs_parameter_spec ext4_param_specs[] = {
1731 	fsparam_flag	("bsddf",		Opt_bsd_df),
1732 	fsparam_flag	("minixdf",		Opt_minix_df),
1733 	fsparam_flag	("grpid",		Opt_grpid),
1734 	fsparam_flag	("bsdgroups",		Opt_grpid),
1735 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1736 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1737 	fsparam_u32	("resgid",		Opt_resgid),
1738 	fsparam_u32	("resuid",		Opt_resuid),
1739 	fsparam_u32	("sb",			Opt_sb),
1740 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1741 	fsparam_flag	("nouid32",		Opt_nouid32),
1742 	fsparam_flag	("debug",		Opt_debug),
1743 	fsparam_flag	("oldalloc",		Opt_removed),
1744 	fsparam_flag	("orlov",		Opt_removed),
1745 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1746 	fsparam_flag	("acl",			Opt_acl),
1747 	fsparam_flag	("norecovery",		Opt_noload),
1748 	fsparam_flag	("noload",		Opt_noload),
1749 	fsparam_flag	("bh",			Opt_removed),
1750 	fsparam_flag	("nobh",		Opt_removed),
1751 	fsparam_u32	("commit",		Opt_commit),
1752 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1753 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1754 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1755 	fsparam_bdev	("journal_path",	Opt_journal_path),
1756 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1757 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1758 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1759 	fsparam_flag	("abort",		Opt_abort),
1760 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1761 	fsparam_enum	("data_err",		Opt_data_err,
1762 						ext4_param_data_err),
1763 	fsparam_string_empty
1764 			("usrjquota",		Opt_usrjquota),
1765 	fsparam_string_empty
1766 			("grpjquota",		Opt_grpjquota),
1767 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1768 	fsparam_flag	("grpquota",		Opt_grpquota),
1769 	fsparam_flag	("quota",		Opt_quota),
1770 	fsparam_flag	("noquota",		Opt_noquota),
1771 	fsparam_flag	("usrquota",		Opt_usrquota),
1772 	fsparam_flag	("prjquota",		Opt_prjquota),
1773 	fsparam_flag	("barrier",		Opt_barrier),
1774 	fsparam_u32	("barrier",		Opt_barrier),
1775 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1776 	fsparam_flag	("i_version",		Opt_removed),
1777 	fsparam_flag	("dax",			Opt_dax),
1778 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1779 	fsparam_u32	("stripe",		Opt_stripe),
1780 	fsparam_flag	("delalloc",		Opt_delalloc),
1781 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1782 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1783 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1784 	fsparam_u32	("debug_want_extra_isize",
1785 						Opt_debug_want_extra_isize),
1786 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1787 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1788 	fsparam_flag	("block_validity",	Opt_block_validity),
1789 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1790 	fsparam_u32	("inode_readahead_blks",
1791 						Opt_inode_readahead_blks),
1792 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1793 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1794 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1795 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1796 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1797 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1798 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1799 	fsparam_flag	("discard",		Opt_discard),
1800 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1801 	fsparam_u32	("init_itable",		Opt_init_itable),
1802 	fsparam_flag	("init_itable",		Opt_init_itable),
1803 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1804 #ifdef CONFIG_EXT4_DEBUG
1805 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1806 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1807 #endif
1808 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1809 	fsparam_flag	("test_dummy_encryption",
1810 						Opt_test_dummy_encryption),
1811 	fsparam_string	("test_dummy_encryption",
1812 						Opt_test_dummy_encryption),
1813 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1814 	fsparam_flag	("nombcache",		Opt_nombcache),
1815 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1816 	fsparam_flag	("prefetch_block_bitmaps",
1817 						Opt_removed),
1818 	fsparam_flag	("no_prefetch_block_bitmaps",
1819 						Opt_no_prefetch_block_bitmaps),
1820 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1821 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1822 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1823 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1824 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1825 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1826 	{}
1827 };
1828 
1829 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1830 
1831 #define MOPT_SET	0x0001
1832 #define MOPT_CLEAR	0x0002
1833 #define MOPT_NOSUPPORT	0x0004
1834 #define MOPT_EXPLICIT	0x0008
1835 #ifdef CONFIG_QUOTA
1836 #define MOPT_Q		0
1837 #define MOPT_QFMT	0x0010
1838 #else
1839 #define MOPT_Q		MOPT_NOSUPPORT
1840 #define MOPT_QFMT	MOPT_NOSUPPORT
1841 #endif
1842 #define MOPT_NO_EXT2	0x0020
1843 #define MOPT_NO_EXT3	0x0040
1844 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1845 #define MOPT_SKIP	0x0080
1846 #define	MOPT_2		0x0100
1847 
1848 static const struct mount_opts {
1849 	int	token;
1850 	int	mount_opt;
1851 	int	flags;
1852 } ext4_mount_opts[] = {
1853 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1854 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1855 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1856 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1857 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1858 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1859 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1860 	 MOPT_EXT4_ONLY | MOPT_SET},
1861 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1862 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1863 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1864 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1865 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1866 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1867 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1868 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1869 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1870 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1871 	{Opt_commit, 0, MOPT_NO_EXT2},
1872 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1873 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1874 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1875 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1876 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1877 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1878 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1879 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1880 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1881 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1882 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1883 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1884 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1885 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1886 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1887 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1888 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1889 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1890 	{Opt_data, 0, MOPT_NO_EXT2},
1891 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1892 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1893 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1894 #else
1895 	{Opt_acl, 0, MOPT_NOSUPPORT},
1896 #endif
1897 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1898 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1899 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1900 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1901 							MOPT_SET | MOPT_Q},
1902 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1903 							MOPT_SET | MOPT_Q},
1904 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1905 							MOPT_SET | MOPT_Q},
1906 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1907 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1908 							MOPT_CLEAR | MOPT_Q},
1909 	{Opt_usrjquota, 0, MOPT_Q},
1910 	{Opt_grpjquota, 0, MOPT_Q},
1911 	{Opt_jqfmt, 0, MOPT_QFMT},
1912 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1913 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1914 	 MOPT_SET},
1915 #ifdef CONFIG_EXT4_DEBUG
1916 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1917 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1918 #endif
1919 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1920 	{Opt_err, 0, 0}
1921 };
1922 
1923 #if IS_ENABLED(CONFIG_UNICODE)
1924 static const struct ext4_sb_encodings {
1925 	__u16 magic;
1926 	char *name;
1927 	unsigned int version;
1928 } ext4_sb_encoding_map[] = {
1929 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1930 };
1931 
1932 static const struct ext4_sb_encodings *
1933 ext4_sb_read_encoding(const struct ext4_super_block *es)
1934 {
1935 	__u16 magic = le16_to_cpu(es->s_encoding);
1936 	int i;
1937 
1938 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1939 		if (magic == ext4_sb_encoding_map[i].magic)
1940 			return &ext4_sb_encoding_map[i];
1941 
1942 	return NULL;
1943 }
1944 #endif
1945 
1946 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1947 #define EXT4_SPEC_JQFMT				(1 <<  1)
1948 #define EXT4_SPEC_DATAJ				(1 <<  2)
1949 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1950 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1951 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1952 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1953 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1954 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1955 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1956 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1957 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1958 #define EXT4_SPEC_s_stripe			(1 << 13)
1959 #define EXT4_SPEC_s_resuid			(1 << 14)
1960 #define EXT4_SPEC_s_resgid			(1 << 15)
1961 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1962 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1963 #define EXT4_SPEC_s_sb_block			(1 << 18)
1964 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1965 
1966 struct ext4_fs_context {
1967 	char		*s_qf_names[EXT4_MAXQUOTAS];
1968 	struct fscrypt_dummy_policy dummy_enc_policy;
1969 	int		s_jquota_fmt;	/* Format of quota to use */
1970 #ifdef CONFIG_EXT4_DEBUG
1971 	int s_fc_debug_max_replay;
1972 #endif
1973 	unsigned short	qname_spec;
1974 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1975 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1976 	unsigned long	journal_devnum;
1977 	unsigned long	s_commit_interval;
1978 	unsigned long	s_stripe;
1979 	unsigned int	s_inode_readahead_blks;
1980 	unsigned int	s_want_extra_isize;
1981 	unsigned int	s_li_wait_mult;
1982 	unsigned int	s_max_dir_size_kb;
1983 	unsigned int	journal_ioprio;
1984 	unsigned int	vals_s_mount_opt;
1985 	unsigned int	mask_s_mount_opt;
1986 	unsigned int	vals_s_mount_opt2;
1987 	unsigned int	mask_s_mount_opt2;
1988 	unsigned int	opt_flags;	/* MOPT flags */
1989 	unsigned int	spec;
1990 	u32		s_max_batch_time;
1991 	u32		s_min_batch_time;
1992 	kuid_t		s_resuid;
1993 	kgid_t		s_resgid;
1994 	ext4_fsblk_t	s_sb_block;
1995 };
1996 
1997 static void ext4_fc_free(struct fs_context *fc)
1998 {
1999 	struct ext4_fs_context *ctx = fc->fs_private;
2000 	int i;
2001 
2002 	if (!ctx)
2003 		return;
2004 
2005 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2006 		kfree(ctx->s_qf_names[i]);
2007 
2008 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2009 	kfree(ctx);
2010 }
2011 
2012 int ext4_init_fs_context(struct fs_context *fc)
2013 {
2014 	struct ext4_fs_context *ctx;
2015 
2016 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2017 	if (!ctx)
2018 		return -ENOMEM;
2019 
2020 	fc->fs_private = ctx;
2021 	fc->ops = &ext4_context_ops;
2022 
2023 	return 0;
2024 }
2025 
2026 #ifdef CONFIG_QUOTA
2027 /*
2028  * Note the name of the specified quota file.
2029  */
2030 static int note_qf_name(struct fs_context *fc, int qtype,
2031 		       struct fs_parameter *param)
2032 {
2033 	struct ext4_fs_context *ctx = fc->fs_private;
2034 	char *qname;
2035 
2036 	if (param->size < 1) {
2037 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2038 		return -EINVAL;
2039 	}
2040 	if (strchr(param->string, '/')) {
2041 		ext4_msg(NULL, KERN_ERR,
2042 			 "quotafile must be on filesystem root");
2043 		return -EINVAL;
2044 	}
2045 	if (ctx->s_qf_names[qtype]) {
2046 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2047 			ext4_msg(NULL, KERN_ERR,
2048 				 "%s quota file already specified",
2049 				 QTYPE2NAME(qtype));
2050 			return -EINVAL;
2051 		}
2052 		return 0;
2053 	}
2054 
2055 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2056 	if (!qname) {
2057 		ext4_msg(NULL, KERN_ERR,
2058 			 "Not enough memory for storing quotafile name");
2059 		return -ENOMEM;
2060 	}
2061 	ctx->s_qf_names[qtype] = qname;
2062 	ctx->qname_spec |= 1 << qtype;
2063 	ctx->spec |= EXT4_SPEC_JQUOTA;
2064 	return 0;
2065 }
2066 
2067 /*
2068  * Clear the name of the specified quota file.
2069  */
2070 static int unnote_qf_name(struct fs_context *fc, int qtype)
2071 {
2072 	struct ext4_fs_context *ctx = fc->fs_private;
2073 
2074 	if (ctx->s_qf_names[qtype])
2075 		kfree(ctx->s_qf_names[qtype]);
2076 
2077 	ctx->s_qf_names[qtype] = NULL;
2078 	ctx->qname_spec |= 1 << qtype;
2079 	ctx->spec |= EXT4_SPEC_JQUOTA;
2080 	return 0;
2081 }
2082 #endif
2083 
2084 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2085 					    struct ext4_fs_context *ctx)
2086 {
2087 	int err;
2088 
2089 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2090 		ext4_msg(NULL, KERN_WARNING,
2091 			 "test_dummy_encryption option not supported");
2092 		return -EINVAL;
2093 	}
2094 	err = fscrypt_parse_test_dummy_encryption(param,
2095 						  &ctx->dummy_enc_policy);
2096 	if (err == -EINVAL) {
2097 		ext4_msg(NULL, KERN_WARNING,
2098 			 "Value of option \"%s\" is unrecognized", param->key);
2099 	} else if (err == -EEXIST) {
2100 		ext4_msg(NULL, KERN_WARNING,
2101 			 "Conflicting test_dummy_encryption options");
2102 		return -EINVAL;
2103 	}
2104 	return err;
2105 }
2106 
2107 #define EXT4_SET_CTX(name)						\
2108 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2109 				  unsigned long flag)			\
2110 {									\
2111 	ctx->mask_s_##name |= flag;					\
2112 	ctx->vals_s_##name |= flag;					\
2113 }
2114 
2115 #define EXT4_CLEAR_CTX(name)						\
2116 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2117 				    unsigned long flag)			\
2118 {									\
2119 	ctx->mask_s_##name |= flag;					\
2120 	ctx->vals_s_##name &= ~flag;					\
2121 }
2122 
2123 #define EXT4_TEST_CTX(name)						\
2124 static inline unsigned long						\
2125 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2126 {									\
2127 	return (ctx->vals_s_##name & flag);				\
2128 }
2129 
2130 EXT4_SET_CTX(flags); /* set only */
2131 EXT4_SET_CTX(mount_opt);
2132 EXT4_CLEAR_CTX(mount_opt);
2133 EXT4_TEST_CTX(mount_opt);
2134 EXT4_SET_CTX(mount_opt2);
2135 EXT4_CLEAR_CTX(mount_opt2);
2136 EXT4_TEST_CTX(mount_opt2);
2137 
2138 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2139 {
2140 	struct ext4_fs_context *ctx = fc->fs_private;
2141 	struct fs_parse_result result;
2142 	const struct mount_opts *m;
2143 	int is_remount;
2144 	kuid_t uid;
2145 	kgid_t gid;
2146 	int token;
2147 
2148 	token = fs_parse(fc, ext4_param_specs, param, &result);
2149 	if (token < 0)
2150 		return token;
2151 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2152 
2153 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2154 		if (token == m->token)
2155 			break;
2156 
2157 	ctx->opt_flags |= m->flags;
2158 
2159 	if (m->flags & MOPT_EXPLICIT) {
2160 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2161 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2162 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2163 			ctx_set_mount_opt2(ctx,
2164 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2165 		} else
2166 			return -EINVAL;
2167 	}
2168 
2169 	if (m->flags & MOPT_NOSUPPORT) {
2170 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2171 			 param->key);
2172 		return 0;
2173 	}
2174 
2175 	switch (token) {
2176 #ifdef CONFIG_QUOTA
2177 	case Opt_usrjquota:
2178 		if (!*param->string)
2179 			return unnote_qf_name(fc, USRQUOTA);
2180 		else
2181 			return note_qf_name(fc, USRQUOTA, param);
2182 	case Opt_grpjquota:
2183 		if (!*param->string)
2184 			return unnote_qf_name(fc, GRPQUOTA);
2185 		else
2186 			return note_qf_name(fc, GRPQUOTA, param);
2187 #endif
2188 	case Opt_sb:
2189 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2190 			ext4_msg(NULL, KERN_WARNING,
2191 				 "Ignoring %s option on remount", param->key);
2192 		} else {
2193 			ctx->s_sb_block = result.uint_32;
2194 			ctx->spec |= EXT4_SPEC_s_sb_block;
2195 		}
2196 		return 0;
2197 	case Opt_removed:
2198 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2199 			 param->key);
2200 		return 0;
2201 	case Opt_inlinecrypt:
2202 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2203 		ctx_set_flags(ctx, SB_INLINECRYPT);
2204 #else
2205 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2206 #endif
2207 		return 0;
2208 	case Opt_errors:
2209 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2210 		ctx_set_mount_opt(ctx, result.uint_32);
2211 		return 0;
2212 #ifdef CONFIG_QUOTA
2213 	case Opt_jqfmt:
2214 		ctx->s_jquota_fmt = result.uint_32;
2215 		ctx->spec |= EXT4_SPEC_JQFMT;
2216 		return 0;
2217 #endif
2218 	case Opt_data:
2219 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2220 		ctx_set_mount_opt(ctx, result.uint_32);
2221 		ctx->spec |= EXT4_SPEC_DATAJ;
2222 		return 0;
2223 	case Opt_commit:
2224 		if (result.uint_32 == 0)
2225 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2226 		else if (result.uint_32 > INT_MAX / HZ) {
2227 			ext4_msg(NULL, KERN_ERR,
2228 				 "Invalid commit interval %d, "
2229 				 "must be smaller than %d",
2230 				 result.uint_32, INT_MAX / HZ);
2231 			return -EINVAL;
2232 		}
2233 		ctx->s_commit_interval = HZ * result.uint_32;
2234 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2235 		return 0;
2236 	case Opt_debug_want_extra_isize:
2237 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2238 			ext4_msg(NULL, KERN_ERR,
2239 				 "Invalid want_extra_isize %d", result.uint_32);
2240 			return -EINVAL;
2241 		}
2242 		ctx->s_want_extra_isize = result.uint_32;
2243 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2244 		return 0;
2245 	case Opt_max_batch_time:
2246 		ctx->s_max_batch_time = result.uint_32;
2247 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2248 		return 0;
2249 	case Opt_min_batch_time:
2250 		ctx->s_min_batch_time = result.uint_32;
2251 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2252 		return 0;
2253 	case Opt_inode_readahead_blks:
2254 		if (result.uint_32 &&
2255 		    (result.uint_32 > (1 << 30) ||
2256 		     !is_power_of_2(result.uint_32))) {
2257 			ext4_msg(NULL, KERN_ERR,
2258 				 "EXT4-fs: inode_readahead_blks must be "
2259 				 "0 or a power of 2 smaller than 2^31");
2260 			return -EINVAL;
2261 		}
2262 		ctx->s_inode_readahead_blks = result.uint_32;
2263 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2264 		return 0;
2265 	case Opt_init_itable:
2266 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2267 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2268 		if (param->type == fs_value_is_string)
2269 			ctx->s_li_wait_mult = result.uint_32;
2270 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2271 		return 0;
2272 	case Opt_max_dir_size_kb:
2273 		ctx->s_max_dir_size_kb = result.uint_32;
2274 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2275 		return 0;
2276 #ifdef CONFIG_EXT4_DEBUG
2277 	case Opt_fc_debug_max_replay:
2278 		ctx->s_fc_debug_max_replay = result.uint_32;
2279 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2280 		return 0;
2281 #endif
2282 	case Opt_stripe:
2283 		ctx->s_stripe = result.uint_32;
2284 		ctx->spec |= EXT4_SPEC_s_stripe;
2285 		return 0;
2286 	case Opt_resuid:
2287 		uid = make_kuid(current_user_ns(), result.uint_32);
2288 		if (!uid_valid(uid)) {
2289 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2290 				 result.uint_32);
2291 			return -EINVAL;
2292 		}
2293 		ctx->s_resuid = uid;
2294 		ctx->spec |= EXT4_SPEC_s_resuid;
2295 		return 0;
2296 	case Opt_resgid:
2297 		gid = make_kgid(current_user_ns(), result.uint_32);
2298 		if (!gid_valid(gid)) {
2299 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2300 				 result.uint_32);
2301 			return -EINVAL;
2302 		}
2303 		ctx->s_resgid = gid;
2304 		ctx->spec |= EXT4_SPEC_s_resgid;
2305 		return 0;
2306 	case Opt_journal_dev:
2307 		if (is_remount) {
2308 			ext4_msg(NULL, KERN_ERR,
2309 				 "Cannot specify journal on remount");
2310 			return -EINVAL;
2311 		}
2312 		ctx->journal_devnum = result.uint_32;
2313 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2314 		return 0;
2315 	case Opt_journal_path:
2316 	{
2317 		struct inode *journal_inode;
2318 		struct path path;
2319 		int error;
2320 
2321 		if (is_remount) {
2322 			ext4_msg(NULL, KERN_ERR,
2323 				 "Cannot specify journal on remount");
2324 			return -EINVAL;
2325 		}
2326 
2327 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2328 		if (error) {
2329 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2330 				 "journal device path");
2331 			return -EINVAL;
2332 		}
2333 
2334 		journal_inode = d_inode(path.dentry);
2335 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2336 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2337 		path_put(&path);
2338 		return 0;
2339 	}
2340 	case Opt_journal_ioprio:
2341 		if (result.uint_32 > 7) {
2342 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2343 				 " (must be 0-7)");
2344 			return -EINVAL;
2345 		}
2346 		ctx->journal_ioprio =
2347 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2348 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2349 		return 0;
2350 	case Opt_test_dummy_encryption:
2351 		return ext4_parse_test_dummy_encryption(param, ctx);
2352 	case Opt_dax:
2353 	case Opt_dax_type:
2354 #ifdef CONFIG_FS_DAX
2355 	{
2356 		int type = (token == Opt_dax) ?
2357 			   Opt_dax : result.uint_32;
2358 
2359 		switch (type) {
2360 		case Opt_dax:
2361 		case Opt_dax_always:
2362 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2363 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2364 			break;
2365 		case Opt_dax_never:
2366 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2367 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2368 			break;
2369 		case Opt_dax_inode:
2370 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2371 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2372 			/* Strictly for printing options */
2373 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2374 			break;
2375 		}
2376 		return 0;
2377 	}
2378 #else
2379 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2380 		return -EINVAL;
2381 #endif
2382 	case Opt_data_err:
2383 		if (result.uint_32 == Opt_data_err_abort)
2384 			ctx_set_mount_opt(ctx, m->mount_opt);
2385 		else if (result.uint_32 == Opt_data_err_ignore)
2386 			ctx_clear_mount_opt(ctx, m->mount_opt);
2387 		return 0;
2388 	case Opt_mb_optimize_scan:
2389 		if (result.int_32 == 1) {
2390 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2391 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2392 		} else if (result.int_32 == 0) {
2393 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2394 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2395 		} else {
2396 			ext4_msg(NULL, KERN_WARNING,
2397 				 "mb_optimize_scan should be set to 0 or 1.");
2398 			return -EINVAL;
2399 		}
2400 		return 0;
2401 	}
2402 
2403 	/*
2404 	 * At this point we should only be getting options requiring MOPT_SET,
2405 	 * or MOPT_CLEAR. Anything else is a bug
2406 	 */
2407 	if (m->token == Opt_err) {
2408 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2409 			 param->key);
2410 		WARN_ON(1);
2411 		return -EINVAL;
2412 	}
2413 
2414 	else {
2415 		unsigned int set = 0;
2416 
2417 		if ((param->type == fs_value_is_flag) ||
2418 		    result.uint_32 > 0)
2419 			set = 1;
2420 
2421 		if (m->flags & MOPT_CLEAR)
2422 			set = !set;
2423 		else if (unlikely(!(m->flags & MOPT_SET))) {
2424 			ext4_msg(NULL, KERN_WARNING,
2425 				 "buggy handling of option %s",
2426 				 param->key);
2427 			WARN_ON(1);
2428 			return -EINVAL;
2429 		}
2430 		if (m->flags & MOPT_2) {
2431 			if (set != 0)
2432 				ctx_set_mount_opt2(ctx, m->mount_opt);
2433 			else
2434 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2435 		} else {
2436 			if (set != 0)
2437 				ctx_set_mount_opt(ctx, m->mount_opt);
2438 			else
2439 				ctx_clear_mount_opt(ctx, m->mount_opt);
2440 		}
2441 	}
2442 
2443 	return 0;
2444 }
2445 
2446 static int parse_options(struct fs_context *fc, char *options)
2447 {
2448 	struct fs_parameter param;
2449 	int ret;
2450 	char *key;
2451 
2452 	if (!options)
2453 		return 0;
2454 
2455 	while ((key = strsep(&options, ",")) != NULL) {
2456 		if (*key) {
2457 			size_t v_len = 0;
2458 			char *value = strchr(key, '=');
2459 
2460 			param.type = fs_value_is_flag;
2461 			param.string = NULL;
2462 
2463 			if (value) {
2464 				if (value == key)
2465 					continue;
2466 
2467 				*value++ = 0;
2468 				v_len = strlen(value);
2469 				param.string = kmemdup_nul(value, v_len,
2470 							   GFP_KERNEL);
2471 				if (!param.string)
2472 					return -ENOMEM;
2473 				param.type = fs_value_is_string;
2474 			}
2475 
2476 			param.key = key;
2477 			param.size = v_len;
2478 
2479 			ret = ext4_parse_param(fc, &param);
2480 			if (param.string)
2481 				kfree(param.string);
2482 			if (ret < 0)
2483 				return ret;
2484 		}
2485 	}
2486 
2487 	ret = ext4_validate_options(fc);
2488 	if (ret < 0)
2489 		return ret;
2490 
2491 	return 0;
2492 }
2493 
2494 static int parse_apply_sb_mount_options(struct super_block *sb,
2495 					struct ext4_fs_context *m_ctx)
2496 {
2497 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2498 	char *s_mount_opts = NULL;
2499 	struct ext4_fs_context *s_ctx = NULL;
2500 	struct fs_context *fc = NULL;
2501 	int ret = -ENOMEM;
2502 
2503 	if (!sbi->s_es->s_mount_opts[0])
2504 		return 0;
2505 
2506 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2507 				sizeof(sbi->s_es->s_mount_opts),
2508 				GFP_KERNEL);
2509 	if (!s_mount_opts)
2510 		return ret;
2511 
2512 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2513 	if (!fc)
2514 		goto out_free;
2515 
2516 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2517 	if (!s_ctx)
2518 		goto out_free;
2519 
2520 	fc->fs_private = s_ctx;
2521 	fc->s_fs_info = sbi;
2522 
2523 	ret = parse_options(fc, s_mount_opts);
2524 	if (ret < 0)
2525 		goto parse_failed;
2526 
2527 	ret = ext4_check_opt_consistency(fc, sb);
2528 	if (ret < 0) {
2529 parse_failed:
2530 		ext4_msg(sb, KERN_WARNING,
2531 			 "failed to parse options in superblock: %s",
2532 			 s_mount_opts);
2533 		ret = 0;
2534 		goto out_free;
2535 	}
2536 
2537 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2538 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2539 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2540 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2541 
2542 	ext4_apply_options(fc, sb);
2543 	ret = 0;
2544 
2545 out_free:
2546 	if (fc) {
2547 		ext4_fc_free(fc);
2548 		kfree(fc);
2549 	}
2550 	kfree(s_mount_opts);
2551 	return ret;
2552 }
2553 
2554 static void ext4_apply_quota_options(struct fs_context *fc,
2555 				     struct super_block *sb)
2556 {
2557 #ifdef CONFIG_QUOTA
2558 	bool quota_feature = ext4_has_feature_quota(sb);
2559 	struct ext4_fs_context *ctx = fc->fs_private;
2560 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2561 	char *qname;
2562 	int i;
2563 
2564 	if (quota_feature)
2565 		return;
2566 
2567 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2568 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2569 			if (!(ctx->qname_spec & (1 << i)))
2570 				continue;
2571 
2572 			qname = ctx->s_qf_names[i]; /* May be NULL */
2573 			if (qname)
2574 				set_opt(sb, QUOTA);
2575 			ctx->s_qf_names[i] = NULL;
2576 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2577 						lockdep_is_held(&sb->s_umount));
2578 			if (qname)
2579 				kfree_rcu_mightsleep(qname);
2580 		}
2581 	}
2582 
2583 	if (ctx->spec & EXT4_SPEC_JQFMT)
2584 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2585 #endif
2586 }
2587 
2588 /*
2589  * Check quota settings consistency.
2590  */
2591 static int ext4_check_quota_consistency(struct fs_context *fc,
2592 					struct super_block *sb)
2593 {
2594 #ifdef CONFIG_QUOTA
2595 	struct ext4_fs_context *ctx = fc->fs_private;
2596 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2597 	bool quota_feature = ext4_has_feature_quota(sb);
2598 	bool quota_loaded = sb_any_quota_loaded(sb);
2599 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2600 	int quota_flags, i;
2601 
2602 	/*
2603 	 * We do the test below only for project quotas. 'usrquota' and
2604 	 * 'grpquota' mount options are allowed even without quota feature
2605 	 * to support legacy quotas in quota files.
2606 	 */
2607 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2608 	    !ext4_has_feature_project(sb)) {
2609 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2610 			 "Cannot enable project quota enforcement.");
2611 		return -EINVAL;
2612 	}
2613 
2614 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2615 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2616 	if (quota_loaded &&
2617 	    ctx->mask_s_mount_opt & quota_flags &&
2618 	    !ctx_test_mount_opt(ctx, quota_flags))
2619 		goto err_quota_change;
2620 
2621 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2622 
2623 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2624 			if (!(ctx->qname_spec & (1 << i)))
2625 				continue;
2626 
2627 			if (quota_loaded &&
2628 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2629 				goto err_jquota_change;
2630 
2631 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2632 			    strcmp(get_qf_name(sb, sbi, i),
2633 				   ctx->s_qf_names[i]) != 0)
2634 				goto err_jquota_specified;
2635 		}
2636 
2637 		if (quota_feature) {
2638 			ext4_msg(NULL, KERN_INFO,
2639 				 "Journaled quota options ignored when "
2640 				 "QUOTA feature is enabled");
2641 			return 0;
2642 		}
2643 	}
2644 
2645 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2646 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2647 			goto err_jquota_change;
2648 		if (quota_feature) {
2649 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2650 				 "ignored when QUOTA feature is enabled");
2651 			return 0;
2652 		}
2653 	}
2654 
2655 	/* Make sure we don't mix old and new quota format */
2656 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2657 		       ctx->s_qf_names[USRQUOTA]);
2658 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2659 		       ctx->s_qf_names[GRPQUOTA]);
2660 
2661 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2662 		    test_opt(sb, USRQUOTA));
2663 
2664 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2665 		    test_opt(sb, GRPQUOTA));
2666 
2667 	if (usr_qf_name) {
2668 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2669 		usrquota = false;
2670 	}
2671 	if (grp_qf_name) {
2672 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2673 		grpquota = false;
2674 	}
2675 
2676 	if (usr_qf_name || grp_qf_name) {
2677 		if (usrquota || grpquota) {
2678 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2679 				 "format mixing");
2680 			return -EINVAL;
2681 		}
2682 
2683 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2684 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2685 				 "not specified");
2686 			return -EINVAL;
2687 		}
2688 	}
2689 
2690 	return 0;
2691 
2692 err_quota_change:
2693 	ext4_msg(NULL, KERN_ERR,
2694 		 "Cannot change quota options when quota turned on");
2695 	return -EINVAL;
2696 err_jquota_change:
2697 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2698 		 "options when quota turned on");
2699 	return -EINVAL;
2700 err_jquota_specified:
2701 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2702 		 QTYPE2NAME(i));
2703 	return -EINVAL;
2704 #else
2705 	return 0;
2706 #endif
2707 }
2708 
2709 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2710 					    struct super_block *sb)
2711 {
2712 	const struct ext4_fs_context *ctx = fc->fs_private;
2713 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2714 
2715 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2716 		return 0;
2717 
2718 	if (!ext4_has_feature_encrypt(sb)) {
2719 		ext4_msg(NULL, KERN_WARNING,
2720 			 "test_dummy_encryption requires encrypt feature");
2721 		return -EINVAL;
2722 	}
2723 	/*
2724 	 * This mount option is just for testing, and it's not worthwhile to
2725 	 * implement the extra complexity (e.g. RCU protection) that would be
2726 	 * needed to allow it to be set or changed during remount.  We do allow
2727 	 * it to be specified during remount, but only if there is no change.
2728 	 */
2729 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2730 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2731 						 &ctx->dummy_enc_policy))
2732 			return 0;
2733 		ext4_msg(NULL, KERN_WARNING,
2734 			 "Can't set or change test_dummy_encryption on remount");
2735 		return -EINVAL;
2736 	}
2737 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2738 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2739 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2740 						 &ctx->dummy_enc_policy))
2741 			return 0;
2742 		ext4_msg(NULL, KERN_WARNING,
2743 			 "Conflicting test_dummy_encryption options");
2744 		return -EINVAL;
2745 	}
2746 	return 0;
2747 }
2748 
2749 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2750 					     struct super_block *sb)
2751 {
2752 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2753 	    /* if already set, it was already verified to be the same */
2754 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2755 		return;
2756 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2757 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2758 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2759 }
2760 
2761 static int ext4_check_opt_consistency(struct fs_context *fc,
2762 				      struct super_block *sb)
2763 {
2764 	struct ext4_fs_context *ctx = fc->fs_private;
2765 	struct ext4_sb_info *sbi = fc->s_fs_info;
2766 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2767 	int err;
2768 
2769 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2770 		ext4_msg(NULL, KERN_ERR,
2771 			 "Mount option(s) incompatible with ext2");
2772 		return -EINVAL;
2773 	}
2774 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2775 		ext4_msg(NULL, KERN_ERR,
2776 			 "Mount option(s) incompatible with ext3");
2777 		return -EINVAL;
2778 	}
2779 
2780 	if (ctx->s_want_extra_isize >
2781 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2782 		ext4_msg(NULL, KERN_ERR,
2783 			 "Invalid want_extra_isize %d",
2784 			 ctx->s_want_extra_isize);
2785 		return -EINVAL;
2786 	}
2787 
2788 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2789 		int blocksize =
2790 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2791 		if (blocksize < PAGE_SIZE)
2792 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2793 				 "experimental mount option 'dioread_nolock' "
2794 				 "for blocksize < PAGE_SIZE");
2795 	}
2796 
2797 	err = ext4_check_test_dummy_encryption(fc, sb);
2798 	if (err)
2799 		return err;
2800 
2801 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2802 		if (!sbi->s_journal) {
2803 			ext4_msg(NULL, KERN_WARNING,
2804 				 "Remounting file system with no journal "
2805 				 "so ignoring journalled data option");
2806 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2807 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2808 			   test_opt(sb, DATA_FLAGS)) {
2809 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2810 				 "on remount");
2811 			return -EINVAL;
2812 		}
2813 	}
2814 
2815 	if (is_remount) {
2816 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2817 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2818 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2819 				 "both data=journal and dax");
2820 			return -EINVAL;
2821 		}
2822 
2823 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2824 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2825 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2826 fail_dax_change_remount:
2827 			ext4_msg(NULL, KERN_ERR, "can't change "
2828 				 "dax mount option while remounting");
2829 			return -EINVAL;
2830 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2831 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2832 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2833 			goto fail_dax_change_remount;
2834 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2835 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2836 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2837 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2838 			goto fail_dax_change_remount;
2839 		}
2840 	}
2841 
2842 	return ext4_check_quota_consistency(fc, sb);
2843 }
2844 
2845 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2846 {
2847 	struct ext4_fs_context *ctx = fc->fs_private;
2848 	struct ext4_sb_info *sbi = fc->s_fs_info;
2849 
2850 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2851 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2852 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2853 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2854 	sb->s_flags &= ~ctx->mask_s_flags;
2855 	sb->s_flags |= ctx->vals_s_flags;
2856 
2857 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2858 	APPLY(s_commit_interval);
2859 	APPLY(s_stripe);
2860 	APPLY(s_max_batch_time);
2861 	APPLY(s_min_batch_time);
2862 	APPLY(s_want_extra_isize);
2863 	APPLY(s_inode_readahead_blks);
2864 	APPLY(s_max_dir_size_kb);
2865 	APPLY(s_li_wait_mult);
2866 	APPLY(s_resgid);
2867 	APPLY(s_resuid);
2868 
2869 #ifdef CONFIG_EXT4_DEBUG
2870 	APPLY(s_fc_debug_max_replay);
2871 #endif
2872 
2873 	ext4_apply_quota_options(fc, sb);
2874 	ext4_apply_test_dummy_encryption(ctx, sb);
2875 }
2876 
2877 
2878 static int ext4_validate_options(struct fs_context *fc)
2879 {
2880 #ifdef CONFIG_QUOTA
2881 	struct ext4_fs_context *ctx = fc->fs_private;
2882 	char *usr_qf_name, *grp_qf_name;
2883 
2884 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2885 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2886 
2887 	if (usr_qf_name || grp_qf_name) {
2888 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2889 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2890 
2891 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2892 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2893 
2894 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2895 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2896 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2897 				 "format mixing");
2898 			return -EINVAL;
2899 		}
2900 	}
2901 #endif
2902 	return 1;
2903 }
2904 
2905 static inline void ext4_show_quota_options(struct seq_file *seq,
2906 					   struct super_block *sb)
2907 {
2908 #if defined(CONFIG_QUOTA)
2909 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2910 	char *usr_qf_name, *grp_qf_name;
2911 
2912 	if (sbi->s_jquota_fmt) {
2913 		char *fmtname = "";
2914 
2915 		switch (sbi->s_jquota_fmt) {
2916 		case QFMT_VFS_OLD:
2917 			fmtname = "vfsold";
2918 			break;
2919 		case QFMT_VFS_V0:
2920 			fmtname = "vfsv0";
2921 			break;
2922 		case QFMT_VFS_V1:
2923 			fmtname = "vfsv1";
2924 			break;
2925 		}
2926 		seq_printf(seq, ",jqfmt=%s", fmtname);
2927 	}
2928 
2929 	rcu_read_lock();
2930 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2931 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2932 	if (usr_qf_name)
2933 		seq_show_option(seq, "usrjquota", usr_qf_name);
2934 	if (grp_qf_name)
2935 		seq_show_option(seq, "grpjquota", grp_qf_name);
2936 	rcu_read_unlock();
2937 #endif
2938 }
2939 
2940 static const char *token2str(int token)
2941 {
2942 	const struct fs_parameter_spec *spec;
2943 
2944 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2945 		if (spec->opt == token && !spec->type)
2946 			break;
2947 	return spec->name;
2948 }
2949 
2950 /*
2951  * Show an option if
2952  *  - it's set to a non-default value OR
2953  *  - if the per-sb default is different from the global default
2954  */
2955 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2956 			      int nodefs)
2957 {
2958 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2959 	struct ext4_super_block *es = sbi->s_es;
2960 	int def_errors;
2961 	const struct mount_opts *m;
2962 	char sep = nodefs ? '\n' : ',';
2963 
2964 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2965 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2966 
2967 	if (sbi->s_sb_block != 1)
2968 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2969 
2970 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2971 		int want_set = m->flags & MOPT_SET;
2972 		int opt_2 = m->flags & MOPT_2;
2973 		unsigned int mount_opt, def_mount_opt;
2974 
2975 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2976 		    m->flags & MOPT_SKIP)
2977 			continue;
2978 
2979 		if (opt_2) {
2980 			mount_opt = sbi->s_mount_opt2;
2981 			def_mount_opt = sbi->s_def_mount_opt2;
2982 		} else {
2983 			mount_opt = sbi->s_mount_opt;
2984 			def_mount_opt = sbi->s_def_mount_opt;
2985 		}
2986 		/* skip if same as the default */
2987 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2988 			continue;
2989 		/* select Opt_noFoo vs Opt_Foo */
2990 		if ((want_set &&
2991 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2992 		    (!want_set && (mount_opt & m->mount_opt)))
2993 			continue;
2994 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2995 	}
2996 
2997 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2998 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2999 		SEQ_OPTS_PRINT("resuid=%u",
3000 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
3001 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
3002 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
3003 		SEQ_OPTS_PRINT("resgid=%u",
3004 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
3005 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
3006 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3007 		SEQ_OPTS_PUTS("errors=remount-ro");
3008 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3009 		SEQ_OPTS_PUTS("errors=continue");
3010 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3011 		SEQ_OPTS_PUTS("errors=panic");
3012 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3013 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3014 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3015 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3016 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3017 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3018 	if (nodefs || sbi->s_stripe)
3019 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3020 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3021 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3022 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3023 			SEQ_OPTS_PUTS("data=journal");
3024 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3025 			SEQ_OPTS_PUTS("data=ordered");
3026 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3027 			SEQ_OPTS_PUTS("data=writeback");
3028 	}
3029 	if (nodefs ||
3030 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3031 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3032 			       sbi->s_inode_readahead_blks);
3033 
3034 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3035 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3036 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3037 	if (nodefs || sbi->s_max_dir_size_kb)
3038 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3039 	if (test_opt(sb, DATA_ERR_ABORT))
3040 		SEQ_OPTS_PUTS("data_err=abort");
3041 
3042 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3043 
3044 	if (sb->s_flags & SB_INLINECRYPT)
3045 		SEQ_OPTS_PUTS("inlinecrypt");
3046 
3047 	if (test_opt(sb, DAX_ALWAYS)) {
3048 		if (IS_EXT2_SB(sb))
3049 			SEQ_OPTS_PUTS("dax");
3050 		else
3051 			SEQ_OPTS_PUTS("dax=always");
3052 	} else if (test_opt2(sb, DAX_NEVER)) {
3053 		SEQ_OPTS_PUTS("dax=never");
3054 	} else if (test_opt2(sb, DAX_INODE)) {
3055 		SEQ_OPTS_PUTS("dax=inode");
3056 	}
3057 
3058 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3059 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3060 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3061 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3062 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3063 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3064 	}
3065 
3066 	ext4_show_quota_options(seq, sb);
3067 	return 0;
3068 }
3069 
3070 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3071 {
3072 	return _ext4_show_options(seq, root->d_sb, 0);
3073 }
3074 
3075 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3076 {
3077 	struct super_block *sb = seq->private;
3078 	int rc;
3079 
3080 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3081 	rc = _ext4_show_options(seq, sb, 1);
3082 	seq_puts(seq, "\n");
3083 	return rc;
3084 }
3085 
3086 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3087 			    int read_only)
3088 {
3089 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3090 	int err = 0;
3091 
3092 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3093 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3094 			 "forcing read-only mode");
3095 		err = -EROFS;
3096 		goto done;
3097 	}
3098 	if (read_only)
3099 		goto done;
3100 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3101 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3102 			 "running e2fsck is recommended");
3103 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3104 		ext4_msg(sb, KERN_WARNING,
3105 			 "warning: mounting fs with errors, "
3106 			 "running e2fsck is recommended");
3107 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3108 		 le16_to_cpu(es->s_mnt_count) >=
3109 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3110 		ext4_msg(sb, KERN_WARNING,
3111 			 "warning: maximal mount count reached, "
3112 			 "running e2fsck is recommended");
3113 	else if (le32_to_cpu(es->s_checkinterval) &&
3114 		 (ext4_get_tstamp(es, s_lastcheck) +
3115 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3116 		ext4_msg(sb, KERN_WARNING,
3117 			 "warning: checktime reached, "
3118 			 "running e2fsck is recommended");
3119 	if (!sbi->s_journal)
3120 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3121 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3122 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3123 	le16_add_cpu(&es->s_mnt_count, 1);
3124 	ext4_update_tstamp(es, s_mtime);
3125 	if (sbi->s_journal) {
3126 		ext4_set_feature_journal_needs_recovery(sb);
3127 		if (ext4_has_feature_orphan_file(sb))
3128 			ext4_set_feature_orphan_present(sb);
3129 	}
3130 
3131 	err = ext4_commit_super(sb);
3132 done:
3133 	if (test_opt(sb, DEBUG))
3134 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3135 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3136 			sb->s_blocksize,
3137 			sbi->s_groups_count,
3138 			EXT4_BLOCKS_PER_GROUP(sb),
3139 			EXT4_INODES_PER_GROUP(sb),
3140 			sbi->s_mount_opt, sbi->s_mount_opt2);
3141 	return err;
3142 }
3143 
3144 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3145 {
3146 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3147 	struct flex_groups **old_groups, **new_groups;
3148 	int size, i, j;
3149 
3150 	if (!sbi->s_log_groups_per_flex)
3151 		return 0;
3152 
3153 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3154 	if (size <= sbi->s_flex_groups_allocated)
3155 		return 0;
3156 
3157 	new_groups = kvzalloc(roundup_pow_of_two(size *
3158 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3159 	if (!new_groups) {
3160 		ext4_msg(sb, KERN_ERR,
3161 			 "not enough memory for %d flex group pointers", size);
3162 		return -ENOMEM;
3163 	}
3164 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3165 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3166 					 sizeof(struct flex_groups)),
3167 					 GFP_KERNEL);
3168 		if (!new_groups[i]) {
3169 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3170 				kvfree(new_groups[j]);
3171 			kvfree(new_groups);
3172 			ext4_msg(sb, KERN_ERR,
3173 				 "not enough memory for %d flex groups", size);
3174 			return -ENOMEM;
3175 		}
3176 	}
3177 	rcu_read_lock();
3178 	old_groups = rcu_dereference(sbi->s_flex_groups);
3179 	if (old_groups)
3180 		memcpy(new_groups, old_groups,
3181 		       (sbi->s_flex_groups_allocated *
3182 			sizeof(struct flex_groups *)));
3183 	rcu_read_unlock();
3184 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3185 	sbi->s_flex_groups_allocated = size;
3186 	if (old_groups)
3187 		ext4_kvfree_array_rcu(old_groups);
3188 	return 0;
3189 }
3190 
3191 static int ext4_fill_flex_info(struct super_block *sb)
3192 {
3193 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3194 	struct ext4_group_desc *gdp = NULL;
3195 	struct flex_groups *fg;
3196 	ext4_group_t flex_group;
3197 	int i, err;
3198 
3199 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3200 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3201 		sbi->s_log_groups_per_flex = 0;
3202 		return 1;
3203 	}
3204 
3205 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3206 	if (err)
3207 		goto failed;
3208 
3209 	for (i = 0; i < sbi->s_groups_count; i++) {
3210 		gdp = ext4_get_group_desc(sb, i, NULL);
3211 
3212 		flex_group = ext4_flex_group(sbi, i);
3213 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3214 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3215 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3216 			     &fg->free_clusters);
3217 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3218 	}
3219 
3220 	return 1;
3221 failed:
3222 	return 0;
3223 }
3224 
3225 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3226 				   struct ext4_group_desc *gdp)
3227 {
3228 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3229 	__u16 crc = 0;
3230 	__le32 le_group = cpu_to_le32(block_group);
3231 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3232 
3233 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3234 		/* Use new metadata_csum algorithm */
3235 		__u32 csum32;
3236 		__u16 dummy_csum = 0;
3237 
3238 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3239 				     sizeof(le_group));
3240 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3241 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3242 				     sizeof(dummy_csum));
3243 		offset += sizeof(dummy_csum);
3244 		if (offset < sbi->s_desc_size)
3245 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3246 					     sbi->s_desc_size - offset);
3247 
3248 		crc = csum32 & 0xFFFF;
3249 		goto out;
3250 	}
3251 
3252 	/* old crc16 code */
3253 	if (!ext4_has_feature_gdt_csum(sb))
3254 		return 0;
3255 
3256 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3257 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3258 	crc = crc16(crc, (__u8 *)gdp, offset);
3259 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3260 	/* for checksum of struct ext4_group_desc do the rest...*/
3261 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3262 		crc = crc16(crc, (__u8 *)gdp + offset,
3263 			    sbi->s_desc_size - offset);
3264 
3265 out:
3266 	return cpu_to_le16(crc);
3267 }
3268 
3269 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3270 				struct ext4_group_desc *gdp)
3271 {
3272 	if (ext4_has_group_desc_csum(sb) &&
3273 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3274 		return 0;
3275 
3276 	return 1;
3277 }
3278 
3279 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3280 			      struct ext4_group_desc *gdp)
3281 {
3282 	if (!ext4_has_group_desc_csum(sb))
3283 		return;
3284 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3285 }
3286 
3287 /* Called at mount-time, super-block is locked */
3288 static int ext4_check_descriptors(struct super_block *sb,
3289 				  ext4_fsblk_t sb_block,
3290 				  ext4_group_t *first_not_zeroed)
3291 {
3292 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3293 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3294 	ext4_fsblk_t last_block;
3295 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3296 	ext4_fsblk_t block_bitmap;
3297 	ext4_fsblk_t inode_bitmap;
3298 	ext4_fsblk_t inode_table;
3299 	int flexbg_flag = 0;
3300 	ext4_group_t i, grp = sbi->s_groups_count;
3301 
3302 	if (ext4_has_feature_flex_bg(sb))
3303 		flexbg_flag = 1;
3304 
3305 	ext4_debug("Checking group descriptors");
3306 
3307 	for (i = 0; i < sbi->s_groups_count; i++) {
3308 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3309 
3310 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3311 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3312 		else
3313 			last_block = first_block +
3314 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3315 
3316 		if ((grp == sbi->s_groups_count) &&
3317 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3318 			grp = i;
3319 
3320 		block_bitmap = ext4_block_bitmap(sb, gdp);
3321 		if (block_bitmap == sb_block) {
3322 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3323 				 "Block bitmap for group %u overlaps "
3324 				 "superblock", i);
3325 			if (!sb_rdonly(sb))
3326 				return 0;
3327 		}
3328 		if (block_bitmap >= sb_block + 1 &&
3329 		    block_bitmap <= last_bg_block) {
3330 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3331 				 "Block bitmap for group %u overlaps "
3332 				 "block group descriptors", i);
3333 			if (!sb_rdonly(sb))
3334 				return 0;
3335 		}
3336 		if (block_bitmap < first_block || block_bitmap > last_block) {
3337 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3338 			       "Block bitmap for group %u not in group "
3339 			       "(block %llu)!", i, block_bitmap);
3340 			return 0;
3341 		}
3342 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3343 		if (inode_bitmap == sb_block) {
3344 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3345 				 "Inode bitmap for group %u overlaps "
3346 				 "superblock", i);
3347 			if (!sb_rdonly(sb))
3348 				return 0;
3349 		}
3350 		if (inode_bitmap >= sb_block + 1 &&
3351 		    inode_bitmap <= last_bg_block) {
3352 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3353 				 "Inode bitmap for group %u overlaps "
3354 				 "block group descriptors", i);
3355 			if (!sb_rdonly(sb))
3356 				return 0;
3357 		}
3358 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3359 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3360 			       "Inode bitmap for group %u not in group "
3361 			       "(block %llu)!", i, inode_bitmap);
3362 			return 0;
3363 		}
3364 		inode_table = ext4_inode_table(sb, gdp);
3365 		if (inode_table == sb_block) {
3366 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3367 				 "Inode table for group %u overlaps "
3368 				 "superblock", i);
3369 			if (!sb_rdonly(sb))
3370 				return 0;
3371 		}
3372 		if (inode_table >= sb_block + 1 &&
3373 		    inode_table <= last_bg_block) {
3374 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3375 				 "Inode table for group %u overlaps "
3376 				 "block group descriptors", i);
3377 			if (!sb_rdonly(sb))
3378 				return 0;
3379 		}
3380 		if (inode_table < first_block ||
3381 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3382 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3383 			       "Inode table for group %u not in group "
3384 			       "(block %llu)!", i, inode_table);
3385 			return 0;
3386 		}
3387 		ext4_lock_group(sb, i);
3388 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3389 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3390 				 "Checksum for group %u failed (%u!=%u)",
3391 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3392 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3393 			if (!sb_rdonly(sb)) {
3394 				ext4_unlock_group(sb, i);
3395 				return 0;
3396 			}
3397 		}
3398 		ext4_unlock_group(sb, i);
3399 		if (!flexbg_flag)
3400 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3401 	}
3402 	if (NULL != first_not_zeroed)
3403 		*first_not_zeroed = grp;
3404 	return 1;
3405 }
3406 
3407 /*
3408  * Maximal extent format file size.
3409  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3410  * extent format containers, within a sector_t, and within i_blocks
3411  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3412  * so that won't be a limiting factor.
3413  *
3414  * However there is other limiting factor. We do store extents in the form
3415  * of starting block and length, hence the resulting length of the extent
3416  * covering maximum file size must fit into on-disk format containers as
3417  * well. Given that length is always by 1 unit bigger than max unit (because
3418  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3419  *
3420  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3421  */
3422 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3423 {
3424 	loff_t res;
3425 	loff_t upper_limit = MAX_LFS_FILESIZE;
3426 
3427 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3428 
3429 	if (!has_huge_files) {
3430 		upper_limit = (1LL << 32) - 1;
3431 
3432 		/* total blocks in file system block size */
3433 		upper_limit >>= (blkbits - 9);
3434 		upper_limit <<= blkbits;
3435 	}
3436 
3437 	/*
3438 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3439 	 * by one fs block, so ee_len can cover the extent of maximum file
3440 	 * size
3441 	 */
3442 	res = (1LL << 32) - 1;
3443 	res <<= blkbits;
3444 
3445 	/* Sanity check against vm- & vfs- imposed limits */
3446 	if (res > upper_limit)
3447 		res = upper_limit;
3448 
3449 	return res;
3450 }
3451 
3452 /*
3453  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3454  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3455  * We need to be 1 filesystem block less than the 2^48 sector limit.
3456  */
3457 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3458 {
3459 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3460 	int meta_blocks;
3461 	unsigned int ppb = 1 << (bits - 2);
3462 
3463 	/*
3464 	 * This is calculated to be the largest file size for a dense, block
3465 	 * mapped file such that the file's total number of 512-byte sectors,
3466 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3467 	 *
3468 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3469 	 * number of 512-byte sectors of the file.
3470 	 */
3471 	if (!has_huge_files) {
3472 		/*
3473 		 * !has_huge_files or implies that the inode i_block field
3474 		 * represents total file blocks in 2^32 512-byte sectors ==
3475 		 * size of vfs inode i_blocks * 8
3476 		 */
3477 		upper_limit = (1LL << 32) - 1;
3478 
3479 		/* total blocks in file system block size */
3480 		upper_limit >>= (bits - 9);
3481 
3482 	} else {
3483 		/*
3484 		 * We use 48 bit ext4_inode i_blocks
3485 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3486 		 * represent total number of blocks in
3487 		 * file system block size
3488 		 */
3489 		upper_limit = (1LL << 48) - 1;
3490 
3491 	}
3492 
3493 	/* Compute how many blocks we can address by block tree */
3494 	res += ppb;
3495 	res += ppb * ppb;
3496 	res += ((loff_t)ppb) * ppb * ppb;
3497 	/* Compute how many metadata blocks are needed */
3498 	meta_blocks = 1;
3499 	meta_blocks += 1 + ppb;
3500 	meta_blocks += 1 + ppb + ppb * ppb;
3501 	/* Does block tree limit file size? */
3502 	if (res + meta_blocks <= upper_limit)
3503 		goto check_lfs;
3504 
3505 	res = upper_limit;
3506 	/* How many metadata blocks are needed for addressing upper_limit? */
3507 	upper_limit -= EXT4_NDIR_BLOCKS;
3508 	/* indirect blocks */
3509 	meta_blocks = 1;
3510 	upper_limit -= ppb;
3511 	/* double indirect blocks */
3512 	if (upper_limit < ppb * ppb) {
3513 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3514 		res -= meta_blocks;
3515 		goto check_lfs;
3516 	}
3517 	meta_blocks += 1 + ppb;
3518 	upper_limit -= ppb * ppb;
3519 	/* tripple indirect blocks for the rest */
3520 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3521 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3522 	res -= meta_blocks;
3523 check_lfs:
3524 	res <<= bits;
3525 	if (res > MAX_LFS_FILESIZE)
3526 		res = MAX_LFS_FILESIZE;
3527 
3528 	return res;
3529 }
3530 
3531 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3532 				   ext4_fsblk_t logical_sb_block, int nr)
3533 {
3534 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3535 	ext4_group_t bg, first_meta_bg;
3536 	int has_super = 0;
3537 
3538 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3539 
3540 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3541 		return logical_sb_block + nr + 1;
3542 	bg = sbi->s_desc_per_block * nr;
3543 	if (ext4_bg_has_super(sb, bg))
3544 		has_super = 1;
3545 
3546 	/*
3547 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3548 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3549 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3550 	 * compensate.
3551 	 */
3552 	if (sb->s_blocksize == 1024 && nr == 0 &&
3553 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3554 		has_super++;
3555 
3556 	return (has_super + ext4_group_first_block_no(sb, bg));
3557 }
3558 
3559 /**
3560  * ext4_get_stripe_size: Get the stripe size.
3561  * @sbi: In memory super block info
3562  *
3563  * If we have specified it via mount option, then
3564  * use the mount option value. If the value specified at mount time is
3565  * greater than the blocks per group use the super block value.
3566  * If the super block value is greater than blocks per group return 0.
3567  * Allocator needs it be less than blocks per group.
3568  *
3569  */
3570 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3571 {
3572 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3573 	unsigned long stripe_width =
3574 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3575 	int ret;
3576 
3577 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3578 		ret = sbi->s_stripe;
3579 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3580 		ret = stripe_width;
3581 	else if (stride && stride <= sbi->s_blocks_per_group)
3582 		ret = stride;
3583 	else
3584 		ret = 0;
3585 
3586 	/*
3587 	 * If the stripe width is 1, this makes no sense and
3588 	 * we set it to 0 to turn off stripe handling code.
3589 	 */
3590 	if (ret <= 1)
3591 		ret = 0;
3592 
3593 	return ret;
3594 }
3595 
3596 /*
3597  * Check whether this filesystem can be mounted based on
3598  * the features present and the RDONLY/RDWR mount requested.
3599  * Returns 1 if this filesystem can be mounted as requested,
3600  * 0 if it cannot be.
3601  */
3602 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3603 {
3604 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3605 		ext4_msg(sb, KERN_ERR,
3606 			"Couldn't mount because of "
3607 			"unsupported optional features (%x)",
3608 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3609 			~EXT4_FEATURE_INCOMPAT_SUPP));
3610 		return 0;
3611 	}
3612 
3613 #if !IS_ENABLED(CONFIG_UNICODE)
3614 	if (ext4_has_feature_casefold(sb)) {
3615 		ext4_msg(sb, KERN_ERR,
3616 			 "Filesystem with casefold feature cannot be "
3617 			 "mounted without CONFIG_UNICODE");
3618 		return 0;
3619 	}
3620 #endif
3621 
3622 	if (readonly)
3623 		return 1;
3624 
3625 	if (ext4_has_feature_readonly(sb)) {
3626 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3627 		sb->s_flags |= SB_RDONLY;
3628 		return 1;
3629 	}
3630 
3631 	/* Check that feature set is OK for a read-write mount */
3632 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3633 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3634 			 "unsupported optional features (%x)",
3635 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3636 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3637 		return 0;
3638 	}
3639 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3640 		ext4_msg(sb, KERN_ERR,
3641 			 "Can't support bigalloc feature without "
3642 			 "extents feature\n");
3643 		return 0;
3644 	}
3645 
3646 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3647 	if (!readonly && (ext4_has_feature_quota(sb) ||
3648 			  ext4_has_feature_project(sb))) {
3649 		ext4_msg(sb, KERN_ERR,
3650 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3651 		return 0;
3652 	}
3653 #endif  /* CONFIG_QUOTA */
3654 	return 1;
3655 }
3656 
3657 /*
3658  * This function is called once a day if we have errors logged
3659  * on the file system
3660  */
3661 static void print_daily_error_info(struct timer_list *t)
3662 {
3663 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3664 	struct super_block *sb = sbi->s_sb;
3665 	struct ext4_super_block *es = sbi->s_es;
3666 
3667 	if (es->s_error_count)
3668 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3669 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3670 			 le32_to_cpu(es->s_error_count));
3671 	if (es->s_first_error_time) {
3672 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3673 		       sb->s_id,
3674 		       ext4_get_tstamp(es, s_first_error_time),
3675 		       (int) sizeof(es->s_first_error_func),
3676 		       es->s_first_error_func,
3677 		       le32_to_cpu(es->s_first_error_line));
3678 		if (es->s_first_error_ino)
3679 			printk(KERN_CONT ": inode %u",
3680 			       le32_to_cpu(es->s_first_error_ino));
3681 		if (es->s_first_error_block)
3682 			printk(KERN_CONT ": block %llu", (unsigned long long)
3683 			       le64_to_cpu(es->s_first_error_block));
3684 		printk(KERN_CONT "\n");
3685 	}
3686 	if (es->s_last_error_time) {
3687 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3688 		       sb->s_id,
3689 		       ext4_get_tstamp(es, s_last_error_time),
3690 		       (int) sizeof(es->s_last_error_func),
3691 		       es->s_last_error_func,
3692 		       le32_to_cpu(es->s_last_error_line));
3693 		if (es->s_last_error_ino)
3694 			printk(KERN_CONT ": inode %u",
3695 			       le32_to_cpu(es->s_last_error_ino));
3696 		if (es->s_last_error_block)
3697 			printk(KERN_CONT ": block %llu", (unsigned long long)
3698 			       le64_to_cpu(es->s_last_error_block));
3699 		printk(KERN_CONT "\n");
3700 	}
3701 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3702 }
3703 
3704 /* Find next suitable group and run ext4_init_inode_table */
3705 static int ext4_run_li_request(struct ext4_li_request *elr)
3706 {
3707 	struct ext4_group_desc *gdp = NULL;
3708 	struct super_block *sb = elr->lr_super;
3709 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3710 	ext4_group_t group = elr->lr_next_group;
3711 	unsigned int prefetch_ios = 0;
3712 	int ret = 0;
3713 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3714 	u64 start_time;
3715 
3716 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3717 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3718 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3719 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3720 		if (group >= elr->lr_next_group) {
3721 			ret = 1;
3722 			if (elr->lr_first_not_zeroed != ngroups &&
3723 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3724 				elr->lr_next_group = elr->lr_first_not_zeroed;
3725 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3726 				ret = 0;
3727 			}
3728 		}
3729 		return ret;
3730 	}
3731 
3732 	for (; group < ngroups; group++) {
3733 		gdp = ext4_get_group_desc(sb, group, NULL);
3734 		if (!gdp) {
3735 			ret = 1;
3736 			break;
3737 		}
3738 
3739 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3740 			break;
3741 	}
3742 
3743 	if (group >= ngroups)
3744 		ret = 1;
3745 
3746 	if (!ret) {
3747 		start_time = ktime_get_real_ns();
3748 		ret = ext4_init_inode_table(sb, group,
3749 					    elr->lr_timeout ? 0 : 1);
3750 		trace_ext4_lazy_itable_init(sb, group);
3751 		if (elr->lr_timeout == 0) {
3752 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3753 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3754 		}
3755 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3756 		elr->lr_next_group = group + 1;
3757 	}
3758 	return ret;
3759 }
3760 
3761 /*
3762  * Remove lr_request from the list_request and free the
3763  * request structure. Should be called with li_list_mtx held
3764  */
3765 static void ext4_remove_li_request(struct ext4_li_request *elr)
3766 {
3767 	if (!elr)
3768 		return;
3769 
3770 	list_del(&elr->lr_request);
3771 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3772 	kfree(elr);
3773 }
3774 
3775 static void ext4_unregister_li_request(struct super_block *sb)
3776 {
3777 	mutex_lock(&ext4_li_mtx);
3778 	if (!ext4_li_info) {
3779 		mutex_unlock(&ext4_li_mtx);
3780 		return;
3781 	}
3782 
3783 	mutex_lock(&ext4_li_info->li_list_mtx);
3784 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3785 	mutex_unlock(&ext4_li_info->li_list_mtx);
3786 	mutex_unlock(&ext4_li_mtx);
3787 }
3788 
3789 static struct task_struct *ext4_lazyinit_task;
3790 
3791 /*
3792  * This is the function where ext4lazyinit thread lives. It walks
3793  * through the request list searching for next scheduled filesystem.
3794  * When such a fs is found, run the lazy initialization request
3795  * (ext4_rn_li_request) and keep track of the time spend in this
3796  * function. Based on that time we compute next schedule time of
3797  * the request. When walking through the list is complete, compute
3798  * next waking time and put itself into sleep.
3799  */
3800 static int ext4_lazyinit_thread(void *arg)
3801 {
3802 	struct ext4_lazy_init *eli = arg;
3803 	struct list_head *pos, *n;
3804 	struct ext4_li_request *elr;
3805 	unsigned long next_wakeup, cur;
3806 
3807 	BUG_ON(NULL == eli);
3808 	set_freezable();
3809 
3810 cont_thread:
3811 	while (true) {
3812 		next_wakeup = MAX_JIFFY_OFFSET;
3813 
3814 		mutex_lock(&eli->li_list_mtx);
3815 		if (list_empty(&eli->li_request_list)) {
3816 			mutex_unlock(&eli->li_list_mtx);
3817 			goto exit_thread;
3818 		}
3819 		list_for_each_safe(pos, n, &eli->li_request_list) {
3820 			int err = 0;
3821 			int progress = 0;
3822 			elr = list_entry(pos, struct ext4_li_request,
3823 					 lr_request);
3824 
3825 			if (time_before(jiffies, elr->lr_next_sched)) {
3826 				if (time_before(elr->lr_next_sched, next_wakeup))
3827 					next_wakeup = elr->lr_next_sched;
3828 				continue;
3829 			}
3830 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3831 				if (sb_start_write_trylock(elr->lr_super)) {
3832 					progress = 1;
3833 					/*
3834 					 * We hold sb->s_umount, sb can not
3835 					 * be removed from the list, it is
3836 					 * now safe to drop li_list_mtx
3837 					 */
3838 					mutex_unlock(&eli->li_list_mtx);
3839 					err = ext4_run_li_request(elr);
3840 					sb_end_write(elr->lr_super);
3841 					mutex_lock(&eli->li_list_mtx);
3842 					n = pos->next;
3843 				}
3844 				up_read((&elr->lr_super->s_umount));
3845 			}
3846 			/* error, remove the lazy_init job */
3847 			if (err) {
3848 				ext4_remove_li_request(elr);
3849 				continue;
3850 			}
3851 			if (!progress) {
3852 				elr->lr_next_sched = jiffies +
3853 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3854 			}
3855 			if (time_before(elr->lr_next_sched, next_wakeup))
3856 				next_wakeup = elr->lr_next_sched;
3857 		}
3858 		mutex_unlock(&eli->li_list_mtx);
3859 
3860 		try_to_freeze();
3861 
3862 		cur = jiffies;
3863 		if ((time_after_eq(cur, next_wakeup)) ||
3864 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3865 			cond_resched();
3866 			continue;
3867 		}
3868 
3869 		schedule_timeout_interruptible(next_wakeup - cur);
3870 
3871 		if (kthread_should_stop()) {
3872 			ext4_clear_request_list();
3873 			goto exit_thread;
3874 		}
3875 	}
3876 
3877 exit_thread:
3878 	/*
3879 	 * It looks like the request list is empty, but we need
3880 	 * to check it under the li_list_mtx lock, to prevent any
3881 	 * additions into it, and of course we should lock ext4_li_mtx
3882 	 * to atomically free the list and ext4_li_info, because at
3883 	 * this point another ext4 filesystem could be registering
3884 	 * new one.
3885 	 */
3886 	mutex_lock(&ext4_li_mtx);
3887 	mutex_lock(&eli->li_list_mtx);
3888 	if (!list_empty(&eli->li_request_list)) {
3889 		mutex_unlock(&eli->li_list_mtx);
3890 		mutex_unlock(&ext4_li_mtx);
3891 		goto cont_thread;
3892 	}
3893 	mutex_unlock(&eli->li_list_mtx);
3894 	kfree(ext4_li_info);
3895 	ext4_li_info = NULL;
3896 	mutex_unlock(&ext4_li_mtx);
3897 
3898 	return 0;
3899 }
3900 
3901 static void ext4_clear_request_list(void)
3902 {
3903 	struct list_head *pos, *n;
3904 	struct ext4_li_request *elr;
3905 
3906 	mutex_lock(&ext4_li_info->li_list_mtx);
3907 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3908 		elr = list_entry(pos, struct ext4_li_request,
3909 				 lr_request);
3910 		ext4_remove_li_request(elr);
3911 	}
3912 	mutex_unlock(&ext4_li_info->li_list_mtx);
3913 }
3914 
3915 static int ext4_run_lazyinit_thread(void)
3916 {
3917 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3918 					 ext4_li_info, "ext4lazyinit");
3919 	if (IS_ERR(ext4_lazyinit_task)) {
3920 		int err = PTR_ERR(ext4_lazyinit_task);
3921 		ext4_clear_request_list();
3922 		kfree(ext4_li_info);
3923 		ext4_li_info = NULL;
3924 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3925 				 "initialization thread\n",
3926 				 err);
3927 		return err;
3928 	}
3929 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3930 	return 0;
3931 }
3932 
3933 /*
3934  * Check whether it make sense to run itable init. thread or not.
3935  * If there is at least one uninitialized inode table, return
3936  * corresponding group number, else the loop goes through all
3937  * groups and return total number of groups.
3938  */
3939 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3940 {
3941 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3942 	struct ext4_group_desc *gdp = NULL;
3943 
3944 	if (!ext4_has_group_desc_csum(sb))
3945 		return ngroups;
3946 
3947 	for (group = 0; group < ngroups; group++) {
3948 		gdp = ext4_get_group_desc(sb, group, NULL);
3949 		if (!gdp)
3950 			continue;
3951 
3952 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3953 			break;
3954 	}
3955 
3956 	return group;
3957 }
3958 
3959 static int ext4_li_info_new(void)
3960 {
3961 	struct ext4_lazy_init *eli = NULL;
3962 
3963 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3964 	if (!eli)
3965 		return -ENOMEM;
3966 
3967 	INIT_LIST_HEAD(&eli->li_request_list);
3968 	mutex_init(&eli->li_list_mtx);
3969 
3970 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3971 
3972 	ext4_li_info = eli;
3973 
3974 	return 0;
3975 }
3976 
3977 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3978 					    ext4_group_t start)
3979 {
3980 	struct ext4_li_request *elr;
3981 
3982 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3983 	if (!elr)
3984 		return NULL;
3985 
3986 	elr->lr_super = sb;
3987 	elr->lr_first_not_zeroed = start;
3988 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3989 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3990 		elr->lr_next_group = start;
3991 	} else {
3992 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3993 	}
3994 
3995 	/*
3996 	 * Randomize first schedule time of the request to
3997 	 * spread the inode table initialization requests
3998 	 * better.
3999 	 */
4000 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
4001 	return elr;
4002 }
4003 
4004 int ext4_register_li_request(struct super_block *sb,
4005 			     ext4_group_t first_not_zeroed)
4006 {
4007 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4008 	struct ext4_li_request *elr = NULL;
4009 	ext4_group_t ngroups = sbi->s_groups_count;
4010 	int ret = 0;
4011 
4012 	mutex_lock(&ext4_li_mtx);
4013 	if (sbi->s_li_request != NULL) {
4014 		/*
4015 		 * Reset timeout so it can be computed again, because
4016 		 * s_li_wait_mult might have changed.
4017 		 */
4018 		sbi->s_li_request->lr_timeout = 0;
4019 		goto out;
4020 	}
4021 
4022 	if (sb_rdonly(sb) ||
4023 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4024 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4025 		goto out;
4026 
4027 	elr = ext4_li_request_new(sb, first_not_zeroed);
4028 	if (!elr) {
4029 		ret = -ENOMEM;
4030 		goto out;
4031 	}
4032 
4033 	if (NULL == ext4_li_info) {
4034 		ret = ext4_li_info_new();
4035 		if (ret)
4036 			goto out;
4037 	}
4038 
4039 	mutex_lock(&ext4_li_info->li_list_mtx);
4040 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4041 	mutex_unlock(&ext4_li_info->li_list_mtx);
4042 
4043 	sbi->s_li_request = elr;
4044 	/*
4045 	 * set elr to NULL here since it has been inserted to
4046 	 * the request_list and the removal and free of it is
4047 	 * handled by ext4_clear_request_list from now on.
4048 	 */
4049 	elr = NULL;
4050 
4051 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4052 		ret = ext4_run_lazyinit_thread();
4053 		if (ret)
4054 			goto out;
4055 	}
4056 out:
4057 	mutex_unlock(&ext4_li_mtx);
4058 	if (ret)
4059 		kfree(elr);
4060 	return ret;
4061 }
4062 
4063 /*
4064  * We do not need to lock anything since this is called on
4065  * module unload.
4066  */
4067 static void ext4_destroy_lazyinit_thread(void)
4068 {
4069 	/*
4070 	 * If thread exited earlier
4071 	 * there's nothing to be done.
4072 	 */
4073 	if (!ext4_li_info || !ext4_lazyinit_task)
4074 		return;
4075 
4076 	kthread_stop(ext4_lazyinit_task);
4077 }
4078 
4079 static int set_journal_csum_feature_set(struct super_block *sb)
4080 {
4081 	int ret = 1;
4082 	int compat, incompat;
4083 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4084 
4085 	if (ext4_has_metadata_csum(sb)) {
4086 		/* journal checksum v3 */
4087 		compat = 0;
4088 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4089 	} else {
4090 		/* journal checksum v1 */
4091 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4092 		incompat = 0;
4093 	}
4094 
4095 	jbd2_journal_clear_features(sbi->s_journal,
4096 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4097 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4098 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4099 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4100 		ret = jbd2_journal_set_features(sbi->s_journal,
4101 				compat, 0,
4102 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4103 				incompat);
4104 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4105 		ret = jbd2_journal_set_features(sbi->s_journal,
4106 				compat, 0,
4107 				incompat);
4108 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4109 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4110 	} else {
4111 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4112 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4113 	}
4114 
4115 	return ret;
4116 }
4117 
4118 /*
4119  * Note: calculating the overhead so we can be compatible with
4120  * historical BSD practice is quite difficult in the face of
4121  * clusters/bigalloc.  This is because multiple metadata blocks from
4122  * different block group can end up in the same allocation cluster.
4123  * Calculating the exact overhead in the face of clustered allocation
4124  * requires either O(all block bitmaps) in memory or O(number of block
4125  * groups**2) in time.  We will still calculate the superblock for
4126  * older file systems --- and if we come across with a bigalloc file
4127  * system with zero in s_overhead_clusters the estimate will be close to
4128  * correct especially for very large cluster sizes --- but for newer
4129  * file systems, it's better to calculate this figure once at mkfs
4130  * time, and store it in the superblock.  If the superblock value is
4131  * present (even for non-bigalloc file systems), we will use it.
4132  */
4133 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4134 			  char *buf)
4135 {
4136 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4137 	struct ext4_group_desc	*gdp;
4138 	ext4_fsblk_t		first_block, last_block, b;
4139 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4140 	int			s, j, count = 0;
4141 	int			has_super = ext4_bg_has_super(sb, grp);
4142 
4143 	if (!ext4_has_feature_bigalloc(sb))
4144 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4145 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4146 			sbi->s_itb_per_group + 2);
4147 
4148 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4149 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4150 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4151 	for (i = 0; i < ngroups; i++) {
4152 		gdp = ext4_get_group_desc(sb, i, NULL);
4153 		b = ext4_block_bitmap(sb, gdp);
4154 		if (b >= first_block && b <= last_block) {
4155 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4156 			count++;
4157 		}
4158 		b = ext4_inode_bitmap(sb, gdp);
4159 		if (b >= first_block && b <= last_block) {
4160 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4161 			count++;
4162 		}
4163 		b = ext4_inode_table(sb, gdp);
4164 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4165 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4166 				int c = EXT4_B2C(sbi, b - first_block);
4167 				ext4_set_bit(c, buf);
4168 				count++;
4169 			}
4170 		if (i != grp)
4171 			continue;
4172 		s = 0;
4173 		if (ext4_bg_has_super(sb, grp)) {
4174 			ext4_set_bit(s++, buf);
4175 			count++;
4176 		}
4177 		j = ext4_bg_num_gdb(sb, grp);
4178 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4179 			ext4_error(sb, "Invalid number of block group "
4180 				   "descriptor blocks: %d", j);
4181 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4182 		}
4183 		count += j;
4184 		for (; j > 0; j--)
4185 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4186 	}
4187 	if (!count)
4188 		return 0;
4189 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4190 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4191 }
4192 
4193 /*
4194  * Compute the overhead and stash it in sbi->s_overhead
4195  */
4196 int ext4_calculate_overhead(struct super_block *sb)
4197 {
4198 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4199 	struct ext4_super_block *es = sbi->s_es;
4200 	struct inode *j_inode;
4201 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4202 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4203 	ext4_fsblk_t overhead = 0;
4204 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4205 
4206 	if (!buf)
4207 		return -ENOMEM;
4208 
4209 	/*
4210 	 * Compute the overhead (FS structures).  This is constant
4211 	 * for a given filesystem unless the number of block groups
4212 	 * changes so we cache the previous value until it does.
4213 	 */
4214 
4215 	/*
4216 	 * All of the blocks before first_data_block are overhead
4217 	 */
4218 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4219 
4220 	/*
4221 	 * Add the overhead found in each block group
4222 	 */
4223 	for (i = 0; i < ngroups; i++) {
4224 		int blks;
4225 
4226 		blks = count_overhead(sb, i, buf);
4227 		overhead += blks;
4228 		if (blks)
4229 			memset(buf, 0, PAGE_SIZE);
4230 		cond_resched();
4231 	}
4232 
4233 	/*
4234 	 * Add the internal journal blocks whether the journal has been
4235 	 * loaded or not
4236 	 */
4237 	if (sbi->s_journal && !sbi->s_journal_bdev)
4238 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4239 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4240 		/* j_inum for internal journal is non-zero */
4241 		j_inode = ext4_get_journal_inode(sb, j_inum);
4242 		if (!IS_ERR(j_inode)) {
4243 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4244 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4245 			iput(j_inode);
4246 		} else {
4247 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4248 		}
4249 	}
4250 	sbi->s_overhead = overhead;
4251 	smp_wmb();
4252 	free_page((unsigned long) buf);
4253 	return 0;
4254 }
4255 
4256 static void ext4_set_resv_clusters(struct super_block *sb)
4257 {
4258 	ext4_fsblk_t resv_clusters;
4259 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4260 
4261 	/*
4262 	 * There's no need to reserve anything when we aren't using extents.
4263 	 * The space estimates are exact, there are no unwritten extents,
4264 	 * hole punching doesn't need new metadata... This is needed especially
4265 	 * to keep ext2/3 backward compatibility.
4266 	 */
4267 	if (!ext4_has_feature_extents(sb))
4268 		return;
4269 	/*
4270 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4271 	 * This should cover the situations where we can not afford to run
4272 	 * out of space like for example punch hole, or converting
4273 	 * unwritten extents in delalloc path. In most cases such
4274 	 * allocation would require 1, or 2 blocks, higher numbers are
4275 	 * very rare.
4276 	 */
4277 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4278 			 sbi->s_cluster_bits);
4279 
4280 	do_div(resv_clusters, 50);
4281 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4282 
4283 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4284 }
4285 
4286 static const char *ext4_quota_mode(struct super_block *sb)
4287 {
4288 #ifdef CONFIG_QUOTA
4289 	if (!ext4_quota_capable(sb))
4290 		return "none";
4291 
4292 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4293 		return "journalled";
4294 	else
4295 		return "writeback";
4296 #else
4297 	return "disabled";
4298 #endif
4299 }
4300 
4301 static void ext4_setup_csum_trigger(struct super_block *sb,
4302 				    enum ext4_journal_trigger_type type,
4303 				    void (*trigger)(
4304 					struct jbd2_buffer_trigger_type *type,
4305 					struct buffer_head *bh,
4306 					void *mapped_data,
4307 					size_t size))
4308 {
4309 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4310 
4311 	sbi->s_journal_triggers[type].sb = sb;
4312 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4313 }
4314 
4315 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4316 {
4317 	if (!sbi)
4318 		return;
4319 
4320 	kfree(sbi->s_blockgroup_lock);
4321 	fs_put_dax(sbi->s_daxdev, NULL);
4322 	kfree(sbi);
4323 }
4324 
4325 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4326 {
4327 	struct ext4_sb_info *sbi;
4328 
4329 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4330 	if (!sbi)
4331 		return NULL;
4332 
4333 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4334 					   NULL, NULL);
4335 
4336 	sbi->s_blockgroup_lock =
4337 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4338 
4339 	if (!sbi->s_blockgroup_lock)
4340 		goto err_out;
4341 
4342 	sb->s_fs_info = sbi;
4343 	sbi->s_sb = sb;
4344 	return sbi;
4345 err_out:
4346 	fs_put_dax(sbi->s_daxdev, NULL);
4347 	kfree(sbi);
4348 	return NULL;
4349 }
4350 
4351 static void ext4_set_def_opts(struct super_block *sb,
4352 			      struct ext4_super_block *es)
4353 {
4354 	unsigned long def_mount_opts;
4355 
4356 	/* Set defaults before we parse the mount options */
4357 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4358 	set_opt(sb, INIT_INODE_TABLE);
4359 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4360 		set_opt(sb, DEBUG);
4361 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4362 		set_opt(sb, GRPID);
4363 	if (def_mount_opts & EXT4_DEFM_UID16)
4364 		set_opt(sb, NO_UID32);
4365 	/* xattr user namespace & acls are now defaulted on */
4366 	set_opt(sb, XATTR_USER);
4367 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4368 	set_opt(sb, POSIX_ACL);
4369 #endif
4370 	if (ext4_has_feature_fast_commit(sb))
4371 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4372 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4373 	if (ext4_has_metadata_csum(sb))
4374 		set_opt(sb, JOURNAL_CHECKSUM);
4375 
4376 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4377 		set_opt(sb, JOURNAL_DATA);
4378 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4379 		set_opt(sb, ORDERED_DATA);
4380 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4381 		set_opt(sb, WRITEBACK_DATA);
4382 
4383 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4384 		set_opt(sb, ERRORS_PANIC);
4385 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4386 		set_opt(sb, ERRORS_CONT);
4387 	else
4388 		set_opt(sb, ERRORS_RO);
4389 	/* block_validity enabled by default; disable with noblock_validity */
4390 	set_opt(sb, BLOCK_VALIDITY);
4391 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4392 		set_opt(sb, DISCARD);
4393 
4394 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4395 		set_opt(sb, BARRIER);
4396 
4397 	/*
4398 	 * enable delayed allocation by default
4399 	 * Use -o nodelalloc to turn it off
4400 	 */
4401 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4402 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4403 		set_opt(sb, DELALLOC);
4404 
4405 	if (sb->s_blocksize == PAGE_SIZE)
4406 		set_opt(sb, DIOREAD_NOLOCK);
4407 }
4408 
4409 static int ext4_handle_clustersize(struct super_block *sb)
4410 {
4411 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4412 	struct ext4_super_block *es = sbi->s_es;
4413 	int clustersize;
4414 
4415 	/* Handle clustersize */
4416 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4417 	if (ext4_has_feature_bigalloc(sb)) {
4418 		if (clustersize < sb->s_blocksize) {
4419 			ext4_msg(sb, KERN_ERR,
4420 				 "cluster size (%d) smaller than "
4421 				 "block size (%lu)", clustersize, sb->s_blocksize);
4422 			return -EINVAL;
4423 		}
4424 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4425 			le32_to_cpu(es->s_log_block_size);
4426 		sbi->s_clusters_per_group =
4427 			le32_to_cpu(es->s_clusters_per_group);
4428 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4429 			ext4_msg(sb, KERN_ERR,
4430 				 "#clusters per group too big: %lu",
4431 				 sbi->s_clusters_per_group);
4432 			return -EINVAL;
4433 		}
4434 		if (sbi->s_blocks_per_group !=
4435 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4436 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4437 				 "clusters per group (%lu) inconsistent",
4438 				 sbi->s_blocks_per_group,
4439 				 sbi->s_clusters_per_group);
4440 			return -EINVAL;
4441 		}
4442 	} else {
4443 		if (clustersize != sb->s_blocksize) {
4444 			ext4_msg(sb, KERN_ERR,
4445 				 "fragment/cluster size (%d) != "
4446 				 "block size (%lu)", clustersize, sb->s_blocksize);
4447 			return -EINVAL;
4448 		}
4449 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4450 			ext4_msg(sb, KERN_ERR,
4451 				 "#blocks per group too big: %lu",
4452 				 sbi->s_blocks_per_group);
4453 			return -EINVAL;
4454 		}
4455 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4456 		sbi->s_cluster_bits = 0;
4457 	}
4458 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4459 
4460 	/* Do we have standard group size of clustersize * 8 blocks ? */
4461 	if (sbi->s_blocks_per_group == clustersize << 3)
4462 		set_opt2(sb, STD_GROUP_SIZE);
4463 
4464 	return 0;
4465 }
4466 
4467 static void ext4_fast_commit_init(struct super_block *sb)
4468 {
4469 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4470 
4471 	/* Initialize fast commit stuff */
4472 	atomic_set(&sbi->s_fc_subtid, 0);
4473 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4474 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4475 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4476 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4477 	sbi->s_fc_bytes = 0;
4478 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4479 	sbi->s_fc_ineligible_tid = 0;
4480 	spin_lock_init(&sbi->s_fc_lock);
4481 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4482 	sbi->s_fc_replay_state.fc_regions = NULL;
4483 	sbi->s_fc_replay_state.fc_regions_size = 0;
4484 	sbi->s_fc_replay_state.fc_regions_used = 0;
4485 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4486 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4487 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4488 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4489 }
4490 
4491 static int ext4_inode_info_init(struct super_block *sb,
4492 				struct ext4_super_block *es)
4493 {
4494 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4495 
4496 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4497 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4498 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4499 	} else {
4500 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4501 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4502 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4503 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4504 				 sbi->s_first_ino);
4505 			return -EINVAL;
4506 		}
4507 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4508 		    (!is_power_of_2(sbi->s_inode_size)) ||
4509 		    (sbi->s_inode_size > sb->s_blocksize)) {
4510 			ext4_msg(sb, KERN_ERR,
4511 			       "unsupported inode size: %d",
4512 			       sbi->s_inode_size);
4513 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4514 			return -EINVAL;
4515 		}
4516 		/*
4517 		 * i_atime_extra is the last extra field available for
4518 		 * [acm]times in struct ext4_inode. Checking for that
4519 		 * field should suffice to ensure we have extra space
4520 		 * for all three.
4521 		 */
4522 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4523 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4524 			sb->s_time_gran = 1;
4525 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4526 		} else {
4527 			sb->s_time_gran = NSEC_PER_SEC;
4528 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4529 		}
4530 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4531 	}
4532 
4533 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4534 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4535 			EXT4_GOOD_OLD_INODE_SIZE;
4536 		if (ext4_has_feature_extra_isize(sb)) {
4537 			unsigned v, max = (sbi->s_inode_size -
4538 					   EXT4_GOOD_OLD_INODE_SIZE);
4539 
4540 			v = le16_to_cpu(es->s_want_extra_isize);
4541 			if (v > max) {
4542 				ext4_msg(sb, KERN_ERR,
4543 					 "bad s_want_extra_isize: %d", v);
4544 				return -EINVAL;
4545 			}
4546 			if (sbi->s_want_extra_isize < v)
4547 				sbi->s_want_extra_isize = v;
4548 
4549 			v = le16_to_cpu(es->s_min_extra_isize);
4550 			if (v > max) {
4551 				ext4_msg(sb, KERN_ERR,
4552 					 "bad s_min_extra_isize: %d", v);
4553 				return -EINVAL;
4554 			}
4555 			if (sbi->s_want_extra_isize < v)
4556 				sbi->s_want_extra_isize = v;
4557 		}
4558 	}
4559 
4560 	return 0;
4561 }
4562 
4563 #if IS_ENABLED(CONFIG_UNICODE)
4564 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4565 {
4566 	const struct ext4_sb_encodings *encoding_info;
4567 	struct unicode_map *encoding;
4568 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4569 
4570 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4571 		return 0;
4572 
4573 	encoding_info = ext4_sb_read_encoding(es);
4574 	if (!encoding_info) {
4575 		ext4_msg(sb, KERN_ERR,
4576 			"Encoding requested by superblock is unknown");
4577 		return -EINVAL;
4578 	}
4579 
4580 	encoding = utf8_load(encoding_info->version);
4581 	if (IS_ERR(encoding)) {
4582 		ext4_msg(sb, KERN_ERR,
4583 			"can't mount with superblock charset: %s-%u.%u.%u "
4584 			"not supported by the kernel. flags: 0x%x.",
4585 			encoding_info->name,
4586 			unicode_major(encoding_info->version),
4587 			unicode_minor(encoding_info->version),
4588 			unicode_rev(encoding_info->version),
4589 			encoding_flags);
4590 		return -EINVAL;
4591 	}
4592 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4593 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4594 		unicode_major(encoding_info->version),
4595 		unicode_minor(encoding_info->version),
4596 		unicode_rev(encoding_info->version),
4597 		encoding_flags);
4598 
4599 	sb->s_encoding = encoding;
4600 	sb->s_encoding_flags = encoding_flags;
4601 
4602 	return 0;
4603 }
4604 #else
4605 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4606 {
4607 	return 0;
4608 }
4609 #endif
4610 
4611 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4612 {
4613 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4614 
4615 	/* Warn if metadata_csum and gdt_csum are both set. */
4616 	if (ext4_has_feature_metadata_csum(sb) &&
4617 	    ext4_has_feature_gdt_csum(sb))
4618 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4619 			     "redundant flags; please run fsck.");
4620 
4621 	/* Check for a known checksum algorithm */
4622 	if (!ext4_verify_csum_type(sb, es)) {
4623 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4624 			 "unknown checksum algorithm.");
4625 		return -EINVAL;
4626 	}
4627 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4628 				ext4_orphan_file_block_trigger);
4629 
4630 	/* Load the checksum driver */
4631 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4632 	if (IS_ERR(sbi->s_chksum_driver)) {
4633 		int ret = PTR_ERR(sbi->s_chksum_driver);
4634 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4635 		sbi->s_chksum_driver = NULL;
4636 		return ret;
4637 	}
4638 
4639 	/* Check superblock checksum */
4640 	if (!ext4_superblock_csum_verify(sb, es)) {
4641 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4642 			 "invalid superblock checksum.  Run e2fsck?");
4643 		return -EFSBADCRC;
4644 	}
4645 
4646 	/* Precompute checksum seed for all metadata */
4647 	if (ext4_has_feature_csum_seed(sb))
4648 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4649 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4650 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4651 					       sizeof(es->s_uuid));
4652 	return 0;
4653 }
4654 
4655 static int ext4_check_feature_compatibility(struct super_block *sb,
4656 					    struct ext4_super_block *es,
4657 					    int silent)
4658 {
4659 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4660 
4661 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4662 	    (ext4_has_compat_features(sb) ||
4663 	     ext4_has_ro_compat_features(sb) ||
4664 	     ext4_has_incompat_features(sb)))
4665 		ext4_msg(sb, KERN_WARNING,
4666 		       "feature flags set on rev 0 fs, "
4667 		       "running e2fsck is recommended");
4668 
4669 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4670 		set_opt2(sb, HURD_COMPAT);
4671 		if (ext4_has_feature_64bit(sb)) {
4672 			ext4_msg(sb, KERN_ERR,
4673 				 "The Hurd can't support 64-bit file systems");
4674 			return -EINVAL;
4675 		}
4676 
4677 		/*
4678 		 * ea_inode feature uses l_i_version field which is not
4679 		 * available in HURD_COMPAT mode.
4680 		 */
4681 		if (ext4_has_feature_ea_inode(sb)) {
4682 			ext4_msg(sb, KERN_ERR,
4683 				 "ea_inode feature is not supported for Hurd");
4684 			return -EINVAL;
4685 		}
4686 	}
4687 
4688 	if (IS_EXT2_SB(sb)) {
4689 		if (ext2_feature_set_ok(sb))
4690 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4691 				 "using the ext4 subsystem");
4692 		else {
4693 			/*
4694 			 * If we're probing be silent, if this looks like
4695 			 * it's actually an ext[34] filesystem.
4696 			 */
4697 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4698 				return -EINVAL;
4699 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4700 				 "to feature incompatibilities");
4701 			return -EINVAL;
4702 		}
4703 	}
4704 
4705 	if (IS_EXT3_SB(sb)) {
4706 		if (ext3_feature_set_ok(sb))
4707 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4708 				 "using the ext4 subsystem");
4709 		else {
4710 			/*
4711 			 * If we're probing be silent, if this looks like
4712 			 * it's actually an ext4 filesystem.
4713 			 */
4714 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4715 				return -EINVAL;
4716 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4717 				 "to feature incompatibilities");
4718 			return -EINVAL;
4719 		}
4720 	}
4721 
4722 	/*
4723 	 * Check feature flags regardless of the revision level, since we
4724 	 * previously didn't change the revision level when setting the flags,
4725 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4726 	 */
4727 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4728 		return -EINVAL;
4729 
4730 	if (sbi->s_daxdev) {
4731 		if (sb->s_blocksize == PAGE_SIZE)
4732 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4733 		else
4734 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4735 	}
4736 
4737 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4738 		if (ext4_has_feature_inline_data(sb)) {
4739 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4740 					" that may contain inline data");
4741 			return -EINVAL;
4742 		}
4743 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4744 			ext4_msg(sb, KERN_ERR,
4745 				"DAX unsupported by block device.");
4746 			return -EINVAL;
4747 		}
4748 	}
4749 
4750 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4751 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4752 			 es->s_encryption_level);
4753 		return -EINVAL;
4754 	}
4755 
4756 	return 0;
4757 }
4758 
4759 static int ext4_check_geometry(struct super_block *sb,
4760 			       struct ext4_super_block *es)
4761 {
4762 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4763 	__u64 blocks_count;
4764 	int err;
4765 
4766 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4767 		ext4_msg(sb, KERN_ERR,
4768 			 "Number of reserved GDT blocks insanely large: %d",
4769 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4770 		return -EINVAL;
4771 	}
4772 	/*
4773 	 * Test whether we have more sectors than will fit in sector_t,
4774 	 * and whether the max offset is addressable by the page cache.
4775 	 */
4776 	err = generic_check_addressable(sb->s_blocksize_bits,
4777 					ext4_blocks_count(es));
4778 	if (err) {
4779 		ext4_msg(sb, KERN_ERR, "filesystem"
4780 			 " too large to mount safely on this system");
4781 		return err;
4782 	}
4783 
4784 	/* check blocks count against device size */
4785 	blocks_count = sb_bdev_nr_blocks(sb);
4786 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4787 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4788 		       "exceeds size of device (%llu blocks)",
4789 		       ext4_blocks_count(es), blocks_count);
4790 		return -EINVAL;
4791 	}
4792 
4793 	/*
4794 	 * It makes no sense for the first data block to be beyond the end
4795 	 * of the filesystem.
4796 	 */
4797 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4798 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4799 			 "block %u is beyond end of filesystem (%llu)",
4800 			 le32_to_cpu(es->s_first_data_block),
4801 			 ext4_blocks_count(es));
4802 		return -EINVAL;
4803 	}
4804 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4805 	    (sbi->s_cluster_ratio == 1)) {
4806 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4807 			 "block is 0 with a 1k block and cluster size");
4808 		return -EINVAL;
4809 	}
4810 
4811 	blocks_count = (ext4_blocks_count(es) -
4812 			le32_to_cpu(es->s_first_data_block) +
4813 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4814 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4815 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4816 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4817 		       "(block count %llu, first data block %u, "
4818 		       "blocks per group %lu)", blocks_count,
4819 		       ext4_blocks_count(es),
4820 		       le32_to_cpu(es->s_first_data_block),
4821 		       EXT4_BLOCKS_PER_GROUP(sb));
4822 		return -EINVAL;
4823 	}
4824 	sbi->s_groups_count = blocks_count;
4825 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4826 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4827 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4828 	    le32_to_cpu(es->s_inodes_count)) {
4829 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4830 			 le32_to_cpu(es->s_inodes_count),
4831 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4832 		return -EINVAL;
4833 	}
4834 
4835 	return 0;
4836 }
4837 
4838 static int ext4_group_desc_init(struct super_block *sb,
4839 				struct ext4_super_block *es,
4840 				ext4_fsblk_t logical_sb_block,
4841 				ext4_group_t *first_not_zeroed)
4842 {
4843 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4844 	unsigned int db_count;
4845 	ext4_fsblk_t block;
4846 	int i;
4847 
4848 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4849 		   EXT4_DESC_PER_BLOCK(sb);
4850 	if (ext4_has_feature_meta_bg(sb)) {
4851 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4852 			ext4_msg(sb, KERN_WARNING,
4853 				 "first meta block group too large: %u "
4854 				 "(group descriptor block count %u)",
4855 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4856 			return -EINVAL;
4857 		}
4858 	}
4859 	rcu_assign_pointer(sbi->s_group_desc,
4860 			   kvmalloc_array(db_count,
4861 					  sizeof(struct buffer_head *),
4862 					  GFP_KERNEL));
4863 	if (sbi->s_group_desc == NULL) {
4864 		ext4_msg(sb, KERN_ERR, "not enough memory");
4865 		return -ENOMEM;
4866 	}
4867 
4868 	bgl_lock_init(sbi->s_blockgroup_lock);
4869 
4870 	/* Pre-read the descriptors into the buffer cache */
4871 	for (i = 0; i < db_count; i++) {
4872 		block = descriptor_loc(sb, logical_sb_block, i);
4873 		ext4_sb_breadahead_unmovable(sb, block);
4874 	}
4875 
4876 	for (i = 0; i < db_count; i++) {
4877 		struct buffer_head *bh;
4878 
4879 		block = descriptor_loc(sb, logical_sb_block, i);
4880 		bh = ext4_sb_bread_unmovable(sb, block);
4881 		if (IS_ERR(bh)) {
4882 			ext4_msg(sb, KERN_ERR,
4883 			       "can't read group descriptor %d", i);
4884 			sbi->s_gdb_count = i;
4885 			return PTR_ERR(bh);
4886 		}
4887 		rcu_read_lock();
4888 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4889 		rcu_read_unlock();
4890 	}
4891 	sbi->s_gdb_count = db_count;
4892 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4893 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4894 		return -EFSCORRUPTED;
4895 	}
4896 
4897 	return 0;
4898 }
4899 
4900 static int ext4_load_and_init_journal(struct super_block *sb,
4901 				      struct ext4_super_block *es,
4902 				      struct ext4_fs_context *ctx)
4903 {
4904 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4905 	int err;
4906 
4907 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4908 	if (err)
4909 		return err;
4910 
4911 	if (ext4_has_feature_64bit(sb) &&
4912 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4913 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4914 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4915 		goto out;
4916 	}
4917 
4918 	if (!set_journal_csum_feature_set(sb)) {
4919 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4920 			 "feature set");
4921 		goto out;
4922 	}
4923 
4924 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4925 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4926 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4927 		ext4_msg(sb, KERN_ERR,
4928 			"Failed to set fast commit journal feature");
4929 		goto out;
4930 	}
4931 
4932 	/* We have now updated the journal if required, so we can
4933 	 * validate the data journaling mode. */
4934 	switch (test_opt(sb, DATA_FLAGS)) {
4935 	case 0:
4936 		/* No mode set, assume a default based on the journal
4937 		 * capabilities: ORDERED_DATA if the journal can
4938 		 * cope, else JOURNAL_DATA
4939 		 */
4940 		if (jbd2_journal_check_available_features
4941 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4942 			set_opt(sb, ORDERED_DATA);
4943 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4944 		} else {
4945 			set_opt(sb, JOURNAL_DATA);
4946 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4947 		}
4948 		break;
4949 
4950 	case EXT4_MOUNT_ORDERED_DATA:
4951 	case EXT4_MOUNT_WRITEBACK_DATA:
4952 		if (!jbd2_journal_check_available_features
4953 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4954 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4955 			       "requested data journaling mode");
4956 			goto out;
4957 		}
4958 		break;
4959 	default:
4960 		break;
4961 	}
4962 
4963 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4964 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4965 		ext4_msg(sb, KERN_ERR, "can't mount with "
4966 			"journal_async_commit in data=ordered mode");
4967 		goto out;
4968 	}
4969 
4970 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4971 
4972 	sbi->s_journal->j_submit_inode_data_buffers =
4973 		ext4_journal_submit_inode_data_buffers;
4974 	sbi->s_journal->j_finish_inode_data_buffers =
4975 		ext4_journal_finish_inode_data_buffers;
4976 
4977 	return 0;
4978 
4979 out:
4980 	/* flush s_sb_upd_work before destroying the journal. */
4981 	flush_work(&sbi->s_sb_upd_work);
4982 	jbd2_journal_destroy(sbi->s_journal);
4983 	sbi->s_journal = NULL;
4984 	return -EINVAL;
4985 }
4986 
4987 static int ext4_check_journal_data_mode(struct super_block *sb)
4988 {
4989 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4990 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4991 			    "data=journal disables delayed allocation, "
4992 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4993 		/* can't mount with both data=journal and dioread_nolock. */
4994 		clear_opt(sb, DIOREAD_NOLOCK);
4995 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4996 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4997 			ext4_msg(sb, KERN_ERR, "can't mount with "
4998 				 "both data=journal and delalloc");
4999 			return -EINVAL;
5000 		}
5001 		if (test_opt(sb, DAX_ALWAYS)) {
5002 			ext4_msg(sb, KERN_ERR, "can't mount with "
5003 				 "both data=journal and dax");
5004 			return -EINVAL;
5005 		}
5006 		if (ext4_has_feature_encrypt(sb)) {
5007 			ext4_msg(sb, KERN_WARNING,
5008 				 "encrypted files will use data=ordered "
5009 				 "instead of data journaling mode");
5010 		}
5011 		if (test_opt(sb, DELALLOC))
5012 			clear_opt(sb, DELALLOC);
5013 	} else {
5014 		sb->s_iflags |= SB_I_CGROUPWB;
5015 	}
5016 
5017 	return 0;
5018 }
5019 
5020 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5021 			   int silent)
5022 {
5023 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5024 	struct ext4_super_block *es;
5025 	ext4_fsblk_t logical_sb_block;
5026 	unsigned long offset = 0;
5027 	struct buffer_head *bh;
5028 	int ret = -EINVAL;
5029 	int blocksize;
5030 
5031 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5032 	if (!blocksize) {
5033 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5034 		return -EINVAL;
5035 	}
5036 
5037 	/*
5038 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5039 	 * block sizes.  We need to calculate the offset from buffer start.
5040 	 */
5041 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5042 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5043 		offset = do_div(logical_sb_block, blocksize);
5044 	} else {
5045 		logical_sb_block = sbi->s_sb_block;
5046 	}
5047 
5048 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5049 	if (IS_ERR(bh)) {
5050 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5051 		return PTR_ERR(bh);
5052 	}
5053 	/*
5054 	 * Note: s_es must be initialized as soon as possible because
5055 	 *       some ext4 macro-instructions depend on its value
5056 	 */
5057 	es = (struct ext4_super_block *) (bh->b_data + offset);
5058 	sbi->s_es = es;
5059 	sb->s_magic = le16_to_cpu(es->s_magic);
5060 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5061 		if (!silent)
5062 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5063 		goto out;
5064 	}
5065 
5066 	if (le32_to_cpu(es->s_log_block_size) >
5067 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5068 		ext4_msg(sb, KERN_ERR,
5069 			 "Invalid log block size: %u",
5070 			 le32_to_cpu(es->s_log_block_size));
5071 		goto out;
5072 	}
5073 	if (le32_to_cpu(es->s_log_cluster_size) >
5074 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5075 		ext4_msg(sb, KERN_ERR,
5076 			 "Invalid log cluster size: %u",
5077 			 le32_to_cpu(es->s_log_cluster_size));
5078 		goto out;
5079 	}
5080 
5081 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5082 
5083 	/*
5084 	 * If the default block size is not the same as the real block size,
5085 	 * we need to reload it.
5086 	 */
5087 	if (sb->s_blocksize == blocksize) {
5088 		*lsb = logical_sb_block;
5089 		sbi->s_sbh = bh;
5090 		return 0;
5091 	}
5092 
5093 	/*
5094 	 * bh must be released before kill_bdev(), otherwise
5095 	 * it won't be freed and its page also. kill_bdev()
5096 	 * is called by sb_set_blocksize().
5097 	 */
5098 	brelse(bh);
5099 	/* Validate the filesystem blocksize */
5100 	if (!sb_set_blocksize(sb, blocksize)) {
5101 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5102 				blocksize);
5103 		bh = NULL;
5104 		goto out;
5105 	}
5106 
5107 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5108 	offset = do_div(logical_sb_block, blocksize);
5109 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5110 	if (IS_ERR(bh)) {
5111 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5112 		ret = PTR_ERR(bh);
5113 		bh = NULL;
5114 		goto out;
5115 	}
5116 	es = (struct ext4_super_block *)(bh->b_data + offset);
5117 	sbi->s_es = es;
5118 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5119 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5120 		goto out;
5121 	}
5122 	*lsb = logical_sb_block;
5123 	sbi->s_sbh = bh;
5124 	return 0;
5125 out:
5126 	brelse(bh);
5127 	return ret;
5128 }
5129 
5130 static void ext4_hash_info_init(struct super_block *sb)
5131 {
5132 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5133 	struct ext4_super_block *es = sbi->s_es;
5134 	unsigned int i;
5135 
5136 	for (i = 0; i < 4; i++)
5137 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5138 
5139 	sbi->s_def_hash_version = es->s_def_hash_version;
5140 	if (ext4_has_feature_dir_index(sb)) {
5141 		i = le32_to_cpu(es->s_flags);
5142 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5143 			sbi->s_hash_unsigned = 3;
5144 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5145 #ifdef __CHAR_UNSIGNED__
5146 			if (!sb_rdonly(sb))
5147 				es->s_flags |=
5148 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5149 			sbi->s_hash_unsigned = 3;
5150 #else
5151 			if (!sb_rdonly(sb))
5152 				es->s_flags |=
5153 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5154 #endif
5155 		}
5156 	}
5157 }
5158 
5159 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5160 {
5161 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5162 	struct ext4_super_block *es = sbi->s_es;
5163 	int has_huge_files;
5164 
5165 	has_huge_files = ext4_has_feature_huge_file(sb);
5166 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5167 						      has_huge_files);
5168 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5169 
5170 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5171 	if (ext4_has_feature_64bit(sb)) {
5172 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5173 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5174 		    !is_power_of_2(sbi->s_desc_size)) {
5175 			ext4_msg(sb, KERN_ERR,
5176 			       "unsupported descriptor size %lu",
5177 			       sbi->s_desc_size);
5178 			return -EINVAL;
5179 		}
5180 	} else
5181 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5182 
5183 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5184 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5185 
5186 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5187 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5188 		if (!silent)
5189 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5190 		return -EINVAL;
5191 	}
5192 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5193 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5194 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5195 			 sbi->s_inodes_per_group);
5196 		return -EINVAL;
5197 	}
5198 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5199 					sbi->s_inodes_per_block;
5200 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5201 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5202 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5203 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5204 
5205 	return 0;
5206 }
5207 
5208 /*
5209  * It's hard to get stripe aligned blocks if stripe is not aligned with
5210  * cluster, just disable stripe and alert user to simplify code and avoid
5211  * stripe aligned allocation which will rarely succeed.
5212  */
5213 static bool ext4_is_stripe_incompatible(struct super_block *sb, unsigned long stripe)
5214 {
5215 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5216 	return (stripe > 0 && sbi->s_cluster_ratio > 1 &&
5217 		stripe % sbi->s_cluster_ratio != 0);
5218 }
5219 
5220 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5221 {
5222 	struct ext4_super_block *es = NULL;
5223 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5224 	ext4_fsblk_t logical_sb_block;
5225 	struct inode *root;
5226 	int needs_recovery;
5227 	int err;
5228 	ext4_group_t first_not_zeroed;
5229 	struct ext4_fs_context *ctx = fc->fs_private;
5230 	int silent = fc->sb_flags & SB_SILENT;
5231 
5232 	/* Set defaults for the variables that will be set during parsing */
5233 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5234 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5235 
5236 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5237 	sbi->s_sectors_written_start =
5238 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5239 
5240 	err = ext4_load_super(sb, &logical_sb_block, silent);
5241 	if (err)
5242 		goto out_fail;
5243 
5244 	es = sbi->s_es;
5245 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5246 
5247 	err = ext4_init_metadata_csum(sb, es);
5248 	if (err)
5249 		goto failed_mount;
5250 
5251 	ext4_set_def_opts(sb, es);
5252 
5253 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5254 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5255 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5256 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5257 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5258 
5259 	/*
5260 	 * set default s_li_wait_mult for lazyinit, for the case there is
5261 	 * no mount option specified.
5262 	 */
5263 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5264 
5265 	err = ext4_inode_info_init(sb, es);
5266 	if (err)
5267 		goto failed_mount;
5268 
5269 	err = parse_apply_sb_mount_options(sb, ctx);
5270 	if (err < 0)
5271 		goto failed_mount;
5272 
5273 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5274 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5275 
5276 	err = ext4_check_opt_consistency(fc, sb);
5277 	if (err < 0)
5278 		goto failed_mount;
5279 
5280 	ext4_apply_options(fc, sb);
5281 
5282 	err = ext4_encoding_init(sb, es);
5283 	if (err)
5284 		goto failed_mount;
5285 
5286 	err = ext4_check_journal_data_mode(sb);
5287 	if (err)
5288 		goto failed_mount;
5289 
5290 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5291 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5292 
5293 	/* i_version is always enabled now */
5294 	sb->s_flags |= SB_I_VERSION;
5295 
5296 	err = ext4_check_feature_compatibility(sb, es, silent);
5297 	if (err)
5298 		goto failed_mount;
5299 
5300 	err = ext4_block_group_meta_init(sb, silent);
5301 	if (err)
5302 		goto failed_mount;
5303 
5304 	ext4_hash_info_init(sb);
5305 
5306 	err = ext4_handle_clustersize(sb);
5307 	if (err)
5308 		goto failed_mount;
5309 
5310 	err = ext4_check_geometry(sb, es);
5311 	if (err)
5312 		goto failed_mount;
5313 
5314 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5315 	spin_lock_init(&sbi->s_error_lock);
5316 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5317 
5318 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5319 	if (err)
5320 		goto failed_mount3;
5321 
5322 	err = ext4_es_register_shrinker(sbi);
5323 	if (err)
5324 		goto failed_mount3;
5325 
5326 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5327 	if (ext4_is_stripe_incompatible(sb, sbi->s_stripe)) {
5328 		ext4_msg(sb, KERN_WARNING,
5329 			 "stripe (%lu) is not aligned with cluster size (%u), "
5330 			 "stripe is disabled",
5331 			 sbi->s_stripe, sbi->s_cluster_ratio);
5332 		sbi->s_stripe = 0;
5333 	}
5334 	sbi->s_extent_max_zeroout_kb = 32;
5335 
5336 	/*
5337 	 * set up enough so that it can read an inode
5338 	 */
5339 	sb->s_op = &ext4_sops;
5340 	sb->s_export_op = &ext4_export_ops;
5341 	sb->s_xattr = ext4_xattr_handlers;
5342 #ifdef CONFIG_FS_ENCRYPTION
5343 	sb->s_cop = &ext4_cryptops;
5344 #endif
5345 #ifdef CONFIG_FS_VERITY
5346 	sb->s_vop = &ext4_verityops;
5347 #endif
5348 #ifdef CONFIG_QUOTA
5349 	sb->dq_op = &ext4_quota_operations;
5350 	if (ext4_has_feature_quota(sb))
5351 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5352 	else
5353 		sb->s_qcop = &ext4_qctl_operations;
5354 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5355 #endif
5356 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5357 
5358 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5359 	mutex_init(&sbi->s_orphan_lock);
5360 
5361 	ext4_fast_commit_init(sb);
5362 
5363 	sb->s_root = NULL;
5364 
5365 	needs_recovery = (es->s_last_orphan != 0 ||
5366 			  ext4_has_feature_orphan_present(sb) ||
5367 			  ext4_has_feature_journal_needs_recovery(sb));
5368 
5369 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5370 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5371 		if (err)
5372 			goto failed_mount3a;
5373 	}
5374 
5375 	err = -EINVAL;
5376 	/*
5377 	 * The first inode we look at is the journal inode.  Don't try
5378 	 * root first: it may be modified in the journal!
5379 	 */
5380 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5381 		err = ext4_load_and_init_journal(sb, es, ctx);
5382 		if (err)
5383 			goto failed_mount3a;
5384 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5385 		   ext4_has_feature_journal_needs_recovery(sb)) {
5386 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5387 		       "suppressed and not mounted read-only");
5388 		goto failed_mount3a;
5389 	} else {
5390 		/* Nojournal mode, all journal mount options are illegal */
5391 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5392 			ext4_msg(sb, KERN_ERR, "can't mount with "
5393 				 "journal_async_commit, fs mounted w/o journal");
5394 			goto failed_mount3a;
5395 		}
5396 
5397 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5398 			ext4_msg(sb, KERN_ERR, "can't mount with "
5399 				 "journal_checksum, fs mounted w/o journal");
5400 			goto failed_mount3a;
5401 		}
5402 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5403 			ext4_msg(sb, KERN_ERR, "can't mount with "
5404 				 "commit=%lu, fs mounted w/o journal",
5405 				 sbi->s_commit_interval / HZ);
5406 			goto failed_mount3a;
5407 		}
5408 		if (EXT4_MOUNT_DATA_FLAGS &
5409 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5410 			ext4_msg(sb, KERN_ERR, "can't mount with "
5411 				 "data=, fs mounted w/o journal");
5412 			goto failed_mount3a;
5413 		}
5414 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5415 		clear_opt(sb, JOURNAL_CHECKSUM);
5416 		clear_opt(sb, DATA_FLAGS);
5417 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5418 		sbi->s_journal = NULL;
5419 		needs_recovery = 0;
5420 	}
5421 
5422 	if (!test_opt(sb, NO_MBCACHE)) {
5423 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5424 		if (!sbi->s_ea_block_cache) {
5425 			ext4_msg(sb, KERN_ERR,
5426 				 "Failed to create ea_block_cache");
5427 			err = -EINVAL;
5428 			goto failed_mount_wq;
5429 		}
5430 
5431 		if (ext4_has_feature_ea_inode(sb)) {
5432 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5433 			if (!sbi->s_ea_inode_cache) {
5434 				ext4_msg(sb, KERN_ERR,
5435 					 "Failed to create ea_inode_cache");
5436 				err = -EINVAL;
5437 				goto failed_mount_wq;
5438 			}
5439 		}
5440 	}
5441 
5442 	/*
5443 	 * Get the # of file system overhead blocks from the
5444 	 * superblock if present.
5445 	 */
5446 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5447 	/* ignore the precalculated value if it is ridiculous */
5448 	if (sbi->s_overhead > ext4_blocks_count(es))
5449 		sbi->s_overhead = 0;
5450 	/*
5451 	 * If the bigalloc feature is not enabled recalculating the
5452 	 * overhead doesn't take long, so we might as well just redo
5453 	 * it to make sure we are using the correct value.
5454 	 */
5455 	if (!ext4_has_feature_bigalloc(sb))
5456 		sbi->s_overhead = 0;
5457 	if (sbi->s_overhead == 0) {
5458 		err = ext4_calculate_overhead(sb);
5459 		if (err)
5460 			goto failed_mount_wq;
5461 	}
5462 
5463 	/*
5464 	 * The maximum number of concurrent works can be high and
5465 	 * concurrency isn't really necessary.  Limit it to 1.
5466 	 */
5467 	EXT4_SB(sb)->rsv_conversion_wq =
5468 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5469 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5470 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5471 		err = -ENOMEM;
5472 		goto failed_mount4;
5473 	}
5474 
5475 	/*
5476 	 * The jbd2_journal_load will have done any necessary log recovery,
5477 	 * so we can safely mount the rest of the filesystem now.
5478 	 */
5479 
5480 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5481 	if (IS_ERR(root)) {
5482 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5483 		err = PTR_ERR(root);
5484 		root = NULL;
5485 		goto failed_mount4;
5486 	}
5487 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5488 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5489 		iput(root);
5490 		err = -EFSCORRUPTED;
5491 		goto failed_mount4;
5492 	}
5493 
5494 	sb->s_root = d_make_root(root);
5495 	if (!sb->s_root) {
5496 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5497 		err = -ENOMEM;
5498 		goto failed_mount4;
5499 	}
5500 
5501 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5502 	if (err == -EROFS) {
5503 		sb->s_flags |= SB_RDONLY;
5504 	} else if (err)
5505 		goto failed_mount4a;
5506 
5507 	ext4_set_resv_clusters(sb);
5508 
5509 	if (test_opt(sb, BLOCK_VALIDITY)) {
5510 		err = ext4_setup_system_zone(sb);
5511 		if (err) {
5512 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5513 				 "zone (%d)", err);
5514 			goto failed_mount4a;
5515 		}
5516 	}
5517 	ext4_fc_replay_cleanup(sb);
5518 
5519 	ext4_ext_init(sb);
5520 
5521 	/*
5522 	 * Enable optimize_scan if number of groups is > threshold. This can be
5523 	 * turned off by passing "mb_optimize_scan=0". This can also be
5524 	 * turned on forcefully by passing "mb_optimize_scan=1".
5525 	 */
5526 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5527 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5528 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5529 		else
5530 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5531 	}
5532 
5533 	err = ext4_mb_init(sb);
5534 	if (err) {
5535 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5536 			 err);
5537 		goto failed_mount5;
5538 	}
5539 
5540 	/*
5541 	 * We can only set up the journal commit callback once
5542 	 * mballoc is initialized
5543 	 */
5544 	if (sbi->s_journal)
5545 		sbi->s_journal->j_commit_callback =
5546 			ext4_journal_commit_callback;
5547 
5548 	err = ext4_percpu_param_init(sbi);
5549 	if (err)
5550 		goto failed_mount6;
5551 
5552 	if (ext4_has_feature_flex_bg(sb))
5553 		if (!ext4_fill_flex_info(sb)) {
5554 			ext4_msg(sb, KERN_ERR,
5555 			       "unable to initialize "
5556 			       "flex_bg meta info!");
5557 			err = -ENOMEM;
5558 			goto failed_mount6;
5559 		}
5560 
5561 	err = ext4_register_li_request(sb, first_not_zeroed);
5562 	if (err)
5563 		goto failed_mount6;
5564 
5565 	err = ext4_init_orphan_info(sb);
5566 	if (err)
5567 		goto failed_mount7;
5568 #ifdef CONFIG_QUOTA
5569 	/* Enable quota usage during mount. */
5570 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5571 		err = ext4_enable_quotas(sb);
5572 		if (err)
5573 			goto failed_mount8;
5574 	}
5575 #endif  /* CONFIG_QUOTA */
5576 
5577 	/*
5578 	 * Save the original bdev mapping's wb_err value which could be
5579 	 * used to detect the metadata async write error.
5580 	 */
5581 	spin_lock_init(&sbi->s_bdev_wb_lock);
5582 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5583 				 &sbi->s_bdev_wb_err);
5584 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5585 	ext4_orphan_cleanup(sb, es);
5586 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5587 	/*
5588 	 * Update the checksum after updating free space/inode counters and
5589 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5590 	 * checksum in the buffer cache until it is written out and
5591 	 * e2fsprogs programs trying to open a file system immediately
5592 	 * after it is mounted can fail.
5593 	 */
5594 	ext4_superblock_csum_set(sb);
5595 	if (needs_recovery) {
5596 		ext4_msg(sb, KERN_INFO, "recovery complete");
5597 		err = ext4_mark_recovery_complete(sb, es);
5598 		if (err)
5599 			goto failed_mount9;
5600 	}
5601 
5602 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5603 		ext4_msg(sb, KERN_WARNING,
5604 			 "mounting with \"discard\" option, but the device does not support discard");
5605 
5606 	if (es->s_error_count)
5607 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5608 
5609 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5610 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5611 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5612 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5613 	atomic_set(&sbi->s_warning_count, 0);
5614 	atomic_set(&sbi->s_msg_count, 0);
5615 
5616 	/* Register sysfs after all initializations are complete. */
5617 	err = ext4_register_sysfs(sb);
5618 	if (err)
5619 		goto failed_mount9;
5620 
5621 	return 0;
5622 
5623 failed_mount9:
5624 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5625 failed_mount8: __maybe_unused
5626 	ext4_release_orphan_info(sb);
5627 failed_mount7:
5628 	ext4_unregister_li_request(sb);
5629 failed_mount6:
5630 	ext4_mb_release(sb);
5631 	ext4_flex_groups_free(sbi);
5632 	ext4_percpu_param_destroy(sbi);
5633 failed_mount5:
5634 	ext4_ext_release(sb);
5635 	ext4_release_system_zone(sb);
5636 failed_mount4a:
5637 	dput(sb->s_root);
5638 	sb->s_root = NULL;
5639 failed_mount4:
5640 	ext4_msg(sb, KERN_ERR, "mount failed");
5641 	if (EXT4_SB(sb)->rsv_conversion_wq)
5642 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5643 failed_mount_wq:
5644 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5645 	sbi->s_ea_inode_cache = NULL;
5646 
5647 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5648 	sbi->s_ea_block_cache = NULL;
5649 
5650 	if (sbi->s_journal) {
5651 		/* flush s_sb_upd_work before journal destroy. */
5652 		flush_work(&sbi->s_sb_upd_work);
5653 		jbd2_journal_destroy(sbi->s_journal);
5654 		sbi->s_journal = NULL;
5655 	}
5656 failed_mount3a:
5657 	ext4_es_unregister_shrinker(sbi);
5658 failed_mount3:
5659 	/* flush s_sb_upd_work before sbi destroy */
5660 	flush_work(&sbi->s_sb_upd_work);
5661 	del_timer_sync(&sbi->s_err_report);
5662 	ext4_stop_mmpd(sbi);
5663 	ext4_group_desc_free(sbi);
5664 failed_mount:
5665 	if (sbi->s_chksum_driver)
5666 		crypto_free_shash(sbi->s_chksum_driver);
5667 
5668 #if IS_ENABLED(CONFIG_UNICODE)
5669 	utf8_unload(sb->s_encoding);
5670 #endif
5671 
5672 #ifdef CONFIG_QUOTA
5673 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5674 		kfree(get_qf_name(sb, sbi, i));
5675 #endif
5676 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5677 	brelse(sbi->s_sbh);
5678 	if (sbi->s_journal_bdev) {
5679 		invalidate_bdev(sbi->s_journal_bdev);
5680 		blkdev_put(sbi->s_journal_bdev, sb);
5681 	}
5682 out_fail:
5683 	invalidate_bdev(sb->s_bdev);
5684 	sb->s_fs_info = NULL;
5685 	return err;
5686 }
5687 
5688 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5689 {
5690 	struct ext4_fs_context *ctx = fc->fs_private;
5691 	struct ext4_sb_info *sbi;
5692 	const char *descr;
5693 	int ret;
5694 
5695 	sbi = ext4_alloc_sbi(sb);
5696 	if (!sbi)
5697 		return -ENOMEM;
5698 
5699 	fc->s_fs_info = sbi;
5700 
5701 	/* Cleanup superblock name */
5702 	strreplace(sb->s_id, '/', '!');
5703 
5704 	sbi->s_sb_block = 1;	/* Default super block location */
5705 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5706 		sbi->s_sb_block = ctx->s_sb_block;
5707 
5708 	ret = __ext4_fill_super(fc, sb);
5709 	if (ret < 0)
5710 		goto free_sbi;
5711 
5712 	if (sbi->s_journal) {
5713 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5714 			descr = " journalled data mode";
5715 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5716 			descr = " ordered data mode";
5717 		else
5718 			descr = " writeback data mode";
5719 	} else
5720 		descr = "out journal";
5721 
5722 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5723 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5724 			 "Quota mode: %s.", &sb->s_uuid,
5725 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5726 			 ext4_quota_mode(sb));
5727 
5728 	/* Update the s_overhead_clusters if necessary */
5729 	ext4_update_overhead(sb, false);
5730 	return 0;
5731 
5732 free_sbi:
5733 	ext4_free_sbi(sbi);
5734 	fc->s_fs_info = NULL;
5735 	return ret;
5736 }
5737 
5738 static int ext4_get_tree(struct fs_context *fc)
5739 {
5740 	return get_tree_bdev(fc, ext4_fill_super);
5741 }
5742 
5743 /*
5744  * Setup any per-fs journal parameters now.  We'll do this both on
5745  * initial mount, once the journal has been initialised but before we've
5746  * done any recovery; and again on any subsequent remount.
5747  */
5748 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5749 {
5750 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5751 
5752 	journal->j_commit_interval = sbi->s_commit_interval;
5753 	journal->j_min_batch_time = sbi->s_min_batch_time;
5754 	journal->j_max_batch_time = sbi->s_max_batch_time;
5755 	ext4_fc_init(sb, journal);
5756 
5757 	write_lock(&journal->j_state_lock);
5758 	if (test_opt(sb, BARRIER))
5759 		journal->j_flags |= JBD2_BARRIER;
5760 	else
5761 		journal->j_flags &= ~JBD2_BARRIER;
5762 	if (test_opt(sb, DATA_ERR_ABORT))
5763 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5764 	else
5765 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5766 	/*
5767 	 * Always enable journal cycle record option, letting the journal
5768 	 * records log transactions continuously between each mount.
5769 	 */
5770 	journal->j_flags |= JBD2_CYCLE_RECORD;
5771 	write_unlock(&journal->j_state_lock);
5772 }
5773 
5774 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5775 					     unsigned int journal_inum)
5776 {
5777 	struct inode *journal_inode;
5778 
5779 	/*
5780 	 * Test for the existence of a valid inode on disk.  Bad things
5781 	 * happen if we iget() an unused inode, as the subsequent iput()
5782 	 * will try to delete it.
5783 	 */
5784 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5785 	if (IS_ERR(journal_inode)) {
5786 		ext4_msg(sb, KERN_ERR, "no journal found");
5787 		return ERR_CAST(journal_inode);
5788 	}
5789 	if (!journal_inode->i_nlink) {
5790 		make_bad_inode(journal_inode);
5791 		iput(journal_inode);
5792 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5793 		return ERR_PTR(-EFSCORRUPTED);
5794 	}
5795 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5796 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5797 		iput(journal_inode);
5798 		return ERR_PTR(-EFSCORRUPTED);
5799 	}
5800 
5801 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5802 		  journal_inode, journal_inode->i_size);
5803 	return journal_inode;
5804 }
5805 
5806 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5807 {
5808 	struct ext4_map_blocks map;
5809 	int ret;
5810 
5811 	if (journal->j_inode == NULL)
5812 		return 0;
5813 
5814 	map.m_lblk = *block;
5815 	map.m_len = 1;
5816 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5817 	if (ret <= 0) {
5818 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5819 			 "journal bmap failed: block %llu ret %d\n",
5820 			 *block, ret);
5821 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5822 		return ret;
5823 	}
5824 	*block = map.m_pblk;
5825 	return 0;
5826 }
5827 
5828 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5829 					  unsigned int journal_inum)
5830 {
5831 	struct inode *journal_inode;
5832 	journal_t *journal;
5833 
5834 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5835 	if (IS_ERR(journal_inode))
5836 		return ERR_CAST(journal_inode);
5837 
5838 	journal = jbd2_journal_init_inode(journal_inode);
5839 	if (IS_ERR(journal)) {
5840 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5841 		iput(journal_inode);
5842 		return ERR_CAST(journal);
5843 	}
5844 	journal->j_private = sb;
5845 	journal->j_bmap = ext4_journal_bmap;
5846 	ext4_init_journal_params(sb, journal);
5847 	return journal;
5848 }
5849 
5850 static struct block_device *ext4_get_journal_blkdev(struct super_block *sb,
5851 					dev_t j_dev, ext4_fsblk_t *j_start,
5852 					ext4_fsblk_t *j_len)
5853 {
5854 	struct buffer_head *bh;
5855 	struct block_device *bdev;
5856 	int hblock, blocksize;
5857 	ext4_fsblk_t sb_block;
5858 	unsigned long offset;
5859 	struct ext4_super_block *es;
5860 	int errno;
5861 
5862 	/* see get_tree_bdev why this is needed and safe */
5863 	up_write(&sb->s_umount);
5864 	bdev = blkdev_get_by_dev(j_dev, BLK_OPEN_READ | BLK_OPEN_WRITE, sb,
5865 				 &fs_holder_ops);
5866 	down_write(&sb->s_umount);
5867 	if (IS_ERR(bdev)) {
5868 		ext4_msg(sb, KERN_ERR,
5869 			 "failed to open journal device unknown-block(%u,%u) %ld",
5870 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev));
5871 		return ERR_CAST(bdev);
5872 	}
5873 
5874 	blocksize = sb->s_blocksize;
5875 	hblock = bdev_logical_block_size(bdev);
5876 	if (blocksize < hblock) {
5877 		ext4_msg(sb, KERN_ERR,
5878 			"blocksize too small for journal device");
5879 		errno = -EINVAL;
5880 		goto out_bdev;
5881 	}
5882 
5883 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5884 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5885 	set_blocksize(bdev, blocksize);
5886 	bh = __bread(bdev, sb_block, blocksize);
5887 	if (!bh) {
5888 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5889 		       "external journal");
5890 		errno = -EINVAL;
5891 		goto out_bdev;
5892 	}
5893 
5894 	es = (struct ext4_super_block *) (bh->b_data + offset);
5895 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5896 	    !(le32_to_cpu(es->s_feature_incompat) &
5897 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5898 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
5899 		errno = -EFSCORRUPTED;
5900 		goto out_bh;
5901 	}
5902 
5903 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5904 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5905 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5906 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
5907 		errno = -EFSCORRUPTED;
5908 		goto out_bh;
5909 	}
5910 
5911 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5912 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5913 		errno = -EFSCORRUPTED;
5914 		goto out_bh;
5915 	}
5916 
5917 	*j_start = sb_block + 1;
5918 	*j_len = ext4_blocks_count(es);
5919 	brelse(bh);
5920 	return bdev;
5921 
5922 out_bh:
5923 	brelse(bh);
5924 out_bdev:
5925 	blkdev_put(bdev, sb);
5926 	return ERR_PTR(errno);
5927 }
5928 
5929 static journal_t *ext4_open_dev_journal(struct super_block *sb,
5930 					dev_t j_dev)
5931 {
5932 	journal_t *journal;
5933 	ext4_fsblk_t j_start;
5934 	ext4_fsblk_t j_len;
5935 	struct block_device *journal_bdev;
5936 	int errno = 0;
5937 
5938 	journal_bdev = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
5939 	if (IS_ERR(journal_bdev))
5940 		return ERR_CAST(journal_bdev);
5941 
5942 	journal = jbd2_journal_init_dev(journal_bdev, sb->s_bdev, j_start,
5943 					j_len, sb->s_blocksize);
5944 	if (IS_ERR(journal)) {
5945 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5946 		errno = PTR_ERR(journal);
5947 		goto out_bdev;
5948 	}
5949 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5950 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5951 					"user (unsupported) - %d",
5952 			be32_to_cpu(journal->j_superblock->s_nr_users));
5953 		errno = -EINVAL;
5954 		goto out_journal;
5955 	}
5956 	journal->j_private = sb;
5957 	EXT4_SB(sb)->s_journal_bdev = journal_bdev;
5958 	ext4_init_journal_params(sb, journal);
5959 	return journal;
5960 
5961 out_journal:
5962 	jbd2_journal_destroy(journal);
5963 out_bdev:
5964 	blkdev_put(journal_bdev, sb);
5965 	return ERR_PTR(errno);
5966 }
5967 
5968 static int ext4_load_journal(struct super_block *sb,
5969 			     struct ext4_super_block *es,
5970 			     unsigned long journal_devnum)
5971 {
5972 	journal_t *journal;
5973 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5974 	dev_t journal_dev;
5975 	int err = 0;
5976 	int really_read_only;
5977 	int journal_dev_ro;
5978 
5979 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5980 		return -EFSCORRUPTED;
5981 
5982 	if (journal_devnum &&
5983 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5984 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5985 			"numbers have changed");
5986 		journal_dev = new_decode_dev(journal_devnum);
5987 	} else
5988 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5989 
5990 	if (journal_inum && journal_dev) {
5991 		ext4_msg(sb, KERN_ERR,
5992 			 "filesystem has both journal inode and journal device!");
5993 		return -EINVAL;
5994 	}
5995 
5996 	if (journal_inum) {
5997 		journal = ext4_open_inode_journal(sb, journal_inum);
5998 		if (IS_ERR(journal))
5999 			return PTR_ERR(journal);
6000 	} else {
6001 		journal = ext4_open_dev_journal(sb, journal_dev);
6002 		if (IS_ERR(journal))
6003 			return PTR_ERR(journal);
6004 	}
6005 
6006 	journal_dev_ro = bdev_read_only(journal->j_dev);
6007 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
6008 
6009 	if (journal_dev_ro && !sb_rdonly(sb)) {
6010 		ext4_msg(sb, KERN_ERR,
6011 			 "journal device read-only, try mounting with '-o ro'");
6012 		err = -EROFS;
6013 		goto err_out;
6014 	}
6015 
6016 	/*
6017 	 * Are we loading a blank journal or performing recovery after a
6018 	 * crash?  For recovery, we need to check in advance whether we
6019 	 * can get read-write access to the device.
6020 	 */
6021 	if (ext4_has_feature_journal_needs_recovery(sb)) {
6022 		if (sb_rdonly(sb)) {
6023 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
6024 					"required on readonly filesystem");
6025 			if (really_read_only) {
6026 				ext4_msg(sb, KERN_ERR, "write access "
6027 					"unavailable, cannot proceed "
6028 					"(try mounting with noload)");
6029 				err = -EROFS;
6030 				goto err_out;
6031 			}
6032 			ext4_msg(sb, KERN_INFO, "write access will "
6033 			       "be enabled during recovery");
6034 		}
6035 	}
6036 
6037 	if (!(journal->j_flags & JBD2_BARRIER))
6038 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6039 
6040 	if (!ext4_has_feature_journal_needs_recovery(sb))
6041 		err = jbd2_journal_wipe(journal, !really_read_only);
6042 	if (!err) {
6043 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6044 		__le16 orig_state;
6045 		bool changed = false;
6046 
6047 		if (save)
6048 			memcpy(save, ((char *) es) +
6049 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6050 		err = jbd2_journal_load(journal);
6051 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6052 				   save, EXT4_S_ERR_LEN)) {
6053 			memcpy(((char *) es) + EXT4_S_ERR_START,
6054 			       save, EXT4_S_ERR_LEN);
6055 			changed = true;
6056 		}
6057 		kfree(save);
6058 		orig_state = es->s_state;
6059 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6060 					   EXT4_ERROR_FS);
6061 		if (orig_state != es->s_state)
6062 			changed = true;
6063 		/* Write out restored error information to the superblock */
6064 		if (changed && !really_read_only) {
6065 			int err2;
6066 			err2 = ext4_commit_super(sb);
6067 			err = err ? : err2;
6068 		}
6069 	}
6070 
6071 	if (err) {
6072 		ext4_msg(sb, KERN_ERR, "error loading journal");
6073 		goto err_out;
6074 	}
6075 
6076 	EXT4_SB(sb)->s_journal = journal;
6077 	err = ext4_clear_journal_err(sb, es);
6078 	if (err) {
6079 		EXT4_SB(sb)->s_journal = NULL;
6080 		jbd2_journal_destroy(journal);
6081 		return err;
6082 	}
6083 
6084 	if (!really_read_only && journal_devnum &&
6085 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6086 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6087 		ext4_commit_super(sb);
6088 	}
6089 	if (!really_read_only && journal_inum &&
6090 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6091 		es->s_journal_inum = cpu_to_le32(journal_inum);
6092 		ext4_commit_super(sb);
6093 	}
6094 
6095 	return 0;
6096 
6097 err_out:
6098 	jbd2_journal_destroy(journal);
6099 	return err;
6100 }
6101 
6102 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6103 static void ext4_update_super(struct super_block *sb)
6104 {
6105 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6106 	struct ext4_super_block *es = sbi->s_es;
6107 	struct buffer_head *sbh = sbi->s_sbh;
6108 
6109 	lock_buffer(sbh);
6110 	/*
6111 	 * If the file system is mounted read-only, don't update the
6112 	 * superblock write time.  This avoids updating the superblock
6113 	 * write time when we are mounting the root file system
6114 	 * read/only but we need to replay the journal; at that point,
6115 	 * for people who are east of GMT and who make their clock
6116 	 * tick in localtime for Windows bug-for-bug compatibility,
6117 	 * the clock is set in the future, and this will cause e2fsck
6118 	 * to complain and force a full file system check.
6119 	 */
6120 	if (!sb_rdonly(sb))
6121 		ext4_update_tstamp(es, s_wtime);
6122 	es->s_kbytes_written =
6123 		cpu_to_le64(sbi->s_kbytes_written +
6124 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6125 		      sbi->s_sectors_written_start) >> 1));
6126 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6127 		ext4_free_blocks_count_set(es,
6128 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6129 				&sbi->s_freeclusters_counter)));
6130 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6131 		es->s_free_inodes_count =
6132 			cpu_to_le32(percpu_counter_sum_positive(
6133 				&sbi->s_freeinodes_counter));
6134 	/* Copy error information to the on-disk superblock */
6135 	spin_lock(&sbi->s_error_lock);
6136 	if (sbi->s_add_error_count > 0) {
6137 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6138 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6139 			__ext4_update_tstamp(&es->s_first_error_time,
6140 					     &es->s_first_error_time_hi,
6141 					     sbi->s_first_error_time);
6142 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6143 				sizeof(es->s_first_error_func));
6144 			es->s_first_error_line =
6145 				cpu_to_le32(sbi->s_first_error_line);
6146 			es->s_first_error_ino =
6147 				cpu_to_le32(sbi->s_first_error_ino);
6148 			es->s_first_error_block =
6149 				cpu_to_le64(sbi->s_first_error_block);
6150 			es->s_first_error_errcode =
6151 				ext4_errno_to_code(sbi->s_first_error_code);
6152 		}
6153 		__ext4_update_tstamp(&es->s_last_error_time,
6154 				     &es->s_last_error_time_hi,
6155 				     sbi->s_last_error_time);
6156 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6157 			sizeof(es->s_last_error_func));
6158 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6159 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6160 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6161 		es->s_last_error_errcode =
6162 				ext4_errno_to_code(sbi->s_last_error_code);
6163 		/*
6164 		 * Start the daily error reporting function if it hasn't been
6165 		 * started already
6166 		 */
6167 		if (!es->s_error_count)
6168 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6169 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6170 		sbi->s_add_error_count = 0;
6171 	}
6172 	spin_unlock(&sbi->s_error_lock);
6173 
6174 	ext4_superblock_csum_set(sb);
6175 	unlock_buffer(sbh);
6176 }
6177 
6178 static int ext4_commit_super(struct super_block *sb)
6179 {
6180 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6181 
6182 	if (!sbh)
6183 		return -EINVAL;
6184 	if (block_device_ejected(sb))
6185 		return -ENODEV;
6186 
6187 	ext4_update_super(sb);
6188 
6189 	lock_buffer(sbh);
6190 	/* Buffer got discarded which means block device got invalidated */
6191 	if (!buffer_mapped(sbh)) {
6192 		unlock_buffer(sbh);
6193 		return -EIO;
6194 	}
6195 
6196 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6197 		/*
6198 		 * Oh, dear.  A previous attempt to write the
6199 		 * superblock failed.  This could happen because the
6200 		 * USB device was yanked out.  Or it could happen to
6201 		 * be a transient write error and maybe the block will
6202 		 * be remapped.  Nothing we can do but to retry the
6203 		 * write and hope for the best.
6204 		 */
6205 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6206 		       "superblock detected");
6207 		clear_buffer_write_io_error(sbh);
6208 		set_buffer_uptodate(sbh);
6209 	}
6210 	get_bh(sbh);
6211 	/* Clear potential dirty bit if it was journalled update */
6212 	clear_buffer_dirty(sbh);
6213 	sbh->b_end_io = end_buffer_write_sync;
6214 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6215 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6216 	wait_on_buffer(sbh);
6217 	if (buffer_write_io_error(sbh)) {
6218 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6219 		       "superblock");
6220 		clear_buffer_write_io_error(sbh);
6221 		set_buffer_uptodate(sbh);
6222 		return -EIO;
6223 	}
6224 	return 0;
6225 }
6226 
6227 /*
6228  * Have we just finished recovery?  If so, and if we are mounting (or
6229  * remounting) the filesystem readonly, then we will end up with a
6230  * consistent fs on disk.  Record that fact.
6231  */
6232 static int ext4_mark_recovery_complete(struct super_block *sb,
6233 				       struct ext4_super_block *es)
6234 {
6235 	int err;
6236 	journal_t *journal = EXT4_SB(sb)->s_journal;
6237 
6238 	if (!ext4_has_feature_journal(sb)) {
6239 		if (journal != NULL) {
6240 			ext4_error(sb, "Journal got removed while the fs was "
6241 				   "mounted!");
6242 			return -EFSCORRUPTED;
6243 		}
6244 		return 0;
6245 	}
6246 	jbd2_journal_lock_updates(journal);
6247 	err = jbd2_journal_flush(journal, 0);
6248 	if (err < 0)
6249 		goto out;
6250 
6251 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6252 	    ext4_has_feature_orphan_present(sb))) {
6253 		if (!ext4_orphan_file_empty(sb)) {
6254 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6255 			err = -EFSCORRUPTED;
6256 			goto out;
6257 		}
6258 		ext4_clear_feature_journal_needs_recovery(sb);
6259 		ext4_clear_feature_orphan_present(sb);
6260 		ext4_commit_super(sb);
6261 	}
6262 out:
6263 	jbd2_journal_unlock_updates(journal);
6264 	return err;
6265 }
6266 
6267 /*
6268  * If we are mounting (or read-write remounting) a filesystem whose journal
6269  * has recorded an error from a previous lifetime, move that error to the
6270  * main filesystem now.
6271  */
6272 static int ext4_clear_journal_err(struct super_block *sb,
6273 				   struct ext4_super_block *es)
6274 {
6275 	journal_t *journal;
6276 	int j_errno;
6277 	const char *errstr;
6278 
6279 	if (!ext4_has_feature_journal(sb)) {
6280 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6281 		return -EFSCORRUPTED;
6282 	}
6283 
6284 	journal = EXT4_SB(sb)->s_journal;
6285 
6286 	/*
6287 	 * Now check for any error status which may have been recorded in the
6288 	 * journal by a prior ext4_error() or ext4_abort()
6289 	 */
6290 
6291 	j_errno = jbd2_journal_errno(journal);
6292 	if (j_errno) {
6293 		char nbuf[16];
6294 
6295 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6296 		ext4_warning(sb, "Filesystem error recorded "
6297 			     "from previous mount: %s", errstr);
6298 
6299 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6300 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6301 		j_errno = ext4_commit_super(sb);
6302 		if (j_errno)
6303 			return j_errno;
6304 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6305 
6306 		jbd2_journal_clear_err(journal);
6307 		jbd2_journal_update_sb_errno(journal);
6308 	}
6309 	return 0;
6310 }
6311 
6312 /*
6313  * Force the running and committing transactions to commit,
6314  * and wait on the commit.
6315  */
6316 int ext4_force_commit(struct super_block *sb)
6317 {
6318 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6319 }
6320 
6321 static int ext4_sync_fs(struct super_block *sb, int wait)
6322 {
6323 	int ret = 0;
6324 	tid_t target;
6325 	bool needs_barrier = false;
6326 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6327 
6328 	if (unlikely(ext4_forced_shutdown(sb)))
6329 		return 0;
6330 
6331 	trace_ext4_sync_fs(sb, wait);
6332 	flush_workqueue(sbi->rsv_conversion_wq);
6333 	/*
6334 	 * Writeback quota in non-journalled quota case - journalled quota has
6335 	 * no dirty dquots
6336 	 */
6337 	dquot_writeback_dquots(sb, -1);
6338 	/*
6339 	 * Data writeback is possible w/o journal transaction, so barrier must
6340 	 * being sent at the end of the function. But we can skip it if
6341 	 * transaction_commit will do it for us.
6342 	 */
6343 	if (sbi->s_journal) {
6344 		target = jbd2_get_latest_transaction(sbi->s_journal);
6345 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6346 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6347 			needs_barrier = true;
6348 
6349 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6350 			if (wait)
6351 				ret = jbd2_log_wait_commit(sbi->s_journal,
6352 							   target);
6353 		}
6354 	} else if (wait && test_opt(sb, BARRIER))
6355 		needs_barrier = true;
6356 	if (needs_barrier) {
6357 		int err;
6358 		err = blkdev_issue_flush(sb->s_bdev);
6359 		if (!ret)
6360 			ret = err;
6361 	}
6362 
6363 	return ret;
6364 }
6365 
6366 /*
6367  * LVM calls this function before a (read-only) snapshot is created.  This
6368  * gives us a chance to flush the journal completely and mark the fs clean.
6369  *
6370  * Note that only this function cannot bring a filesystem to be in a clean
6371  * state independently. It relies on upper layer to stop all data & metadata
6372  * modifications.
6373  */
6374 static int ext4_freeze(struct super_block *sb)
6375 {
6376 	int error = 0;
6377 	journal_t *journal = EXT4_SB(sb)->s_journal;
6378 
6379 	if (journal) {
6380 		/* Now we set up the journal barrier. */
6381 		jbd2_journal_lock_updates(journal);
6382 
6383 		/*
6384 		 * Don't clear the needs_recovery flag if we failed to
6385 		 * flush the journal.
6386 		 */
6387 		error = jbd2_journal_flush(journal, 0);
6388 		if (error < 0)
6389 			goto out;
6390 
6391 		/* Journal blocked and flushed, clear needs_recovery flag. */
6392 		ext4_clear_feature_journal_needs_recovery(sb);
6393 		if (ext4_orphan_file_empty(sb))
6394 			ext4_clear_feature_orphan_present(sb);
6395 	}
6396 
6397 	error = ext4_commit_super(sb);
6398 out:
6399 	if (journal)
6400 		/* we rely on upper layer to stop further updates */
6401 		jbd2_journal_unlock_updates(journal);
6402 	return error;
6403 }
6404 
6405 /*
6406  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6407  * flag here, even though the filesystem is not technically dirty yet.
6408  */
6409 static int ext4_unfreeze(struct super_block *sb)
6410 {
6411 	if (ext4_forced_shutdown(sb))
6412 		return 0;
6413 
6414 	if (EXT4_SB(sb)->s_journal) {
6415 		/* Reset the needs_recovery flag before the fs is unlocked. */
6416 		ext4_set_feature_journal_needs_recovery(sb);
6417 		if (ext4_has_feature_orphan_file(sb))
6418 			ext4_set_feature_orphan_present(sb);
6419 	}
6420 
6421 	ext4_commit_super(sb);
6422 	return 0;
6423 }
6424 
6425 /*
6426  * Structure to save mount options for ext4_remount's benefit
6427  */
6428 struct ext4_mount_options {
6429 	unsigned long s_mount_opt;
6430 	unsigned long s_mount_opt2;
6431 	kuid_t s_resuid;
6432 	kgid_t s_resgid;
6433 	unsigned long s_commit_interval;
6434 	u32 s_min_batch_time, s_max_batch_time;
6435 #ifdef CONFIG_QUOTA
6436 	int s_jquota_fmt;
6437 	char *s_qf_names[EXT4_MAXQUOTAS];
6438 #endif
6439 };
6440 
6441 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6442 {
6443 	struct ext4_fs_context *ctx = fc->fs_private;
6444 	struct ext4_super_block *es;
6445 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6446 	unsigned long old_sb_flags;
6447 	struct ext4_mount_options old_opts;
6448 	ext4_group_t g;
6449 	int err = 0;
6450 	int alloc_ctx;
6451 #ifdef CONFIG_QUOTA
6452 	int enable_quota = 0;
6453 	int i, j;
6454 	char *to_free[EXT4_MAXQUOTAS];
6455 #endif
6456 
6457 
6458 	/* Store the original options */
6459 	old_sb_flags = sb->s_flags;
6460 	old_opts.s_mount_opt = sbi->s_mount_opt;
6461 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6462 	old_opts.s_resuid = sbi->s_resuid;
6463 	old_opts.s_resgid = sbi->s_resgid;
6464 	old_opts.s_commit_interval = sbi->s_commit_interval;
6465 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6466 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6467 #ifdef CONFIG_QUOTA
6468 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6469 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6470 		if (sbi->s_qf_names[i]) {
6471 			char *qf_name = get_qf_name(sb, sbi, i);
6472 
6473 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6474 			if (!old_opts.s_qf_names[i]) {
6475 				for (j = 0; j < i; j++)
6476 					kfree(old_opts.s_qf_names[j]);
6477 				return -ENOMEM;
6478 			}
6479 		} else
6480 			old_opts.s_qf_names[i] = NULL;
6481 #endif
6482 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6483 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6484 			ctx->journal_ioprio =
6485 				sbi->s_journal->j_task->io_context->ioprio;
6486 		else
6487 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6488 
6489 	}
6490 
6491 	if ((ctx->spec & EXT4_SPEC_s_stripe) &&
6492 	    ext4_is_stripe_incompatible(sb, ctx->s_stripe)) {
6493 		ext4_msg(sb, KERN_WARNING,
6494 			 "stripe (%lu) is not aligned with cluster size (%u), "
6495 			 "stripe is disabled",
6496 			 ctx->s_stripe, sbi->s_cluster_ratio);
6497 		ctx->s_stripe = 0;
6498 	}
6499 
6500 	/*
6501 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6502 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6503 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6504 	 * here s_writepages_rwsem to avoid race between writepages ops and
6505 	 * remount.
6506 	 */
6507 	alloc_ctx = ext4_writepages_down_write(sb);
6508 	ext4_apply_options(fc, sb);
6509 	ext4_writepages_up_write(sb, alloc_ctx);
6510 
6511 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6512 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6513 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6514 			 "during remount not supported; ignoring");
6515 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6516 	}
6517 
6518 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6519 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6520 			ext4_msg(sb, KERN_ERR, "can't mount with "
6521 				 "both data=journal and delalloc");
6522 			err = -EINVAL;
6523 			goto restore_opts;
6524 		}
6525 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6526 			ext4_msg(sb, KERN_ERR, "can't mount with "
6527 				 "both data=journal and dioread_nolock");
6528 			err = -EINVAL;
6529 			goto restore_opts;
6530 		}
6531 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6532 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6533 			ext4_msg(sb, KERN_ERR, "can't mount with "
6534 				"journal_async_commit in data=ordered mode");
6535 			err = -EINVAL;
6536 			goto restore_opts;
6537 		}
6538 	}
6539 
6540 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6541 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6542 		err = -EINVAL;
6543 		goto restore_opts;
6544 	}
6545 
6546 	if (test_opt2(sb, ABORT))
6547 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6548 
6549 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6550 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6551 
6552 	es = sbi->s_es;
6553 
6554 	if (sbi->s_journal) {
6555 		ext4_init_journal_params(sb, sbi->s_journal);
6556 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6557 	}
6558 
6559 	/* Flush outstanding errors before changing fs state */
6560 	flush_work(&sbi->s_sb_upd_work);
6561 
6562 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6563 		if (ext4_forced_shutdown(sb)) {
6564 			err = -EROFS;
6565 			goto restore_opts;
6566 		}
6567 
6568 		if (fc->sb_flags & SB_RDONLY) {
6569 			err = sync_filesystem(sb);
6570 			if (err < 0)
6571 				goto restore_opts;
6572 			err = dquot_suspend(sb, -1);
6573 			if (err < 0)
6574 				goto restore_opts;
6575 
6576 			/*
6577 			 * First of all, the unconditional stuff we have to do
6578 			 * to disable replay of the journal when we next remount
6579 			 */
6580 			sb->s_flags |= SB_RDONLY;
6581 
6582 			/*
6583 			 * OK, test if we are remounting a valid rw partition
6584 			 * readonly, and if so set the rdonly flag and then
6585 			 * mark the partition as valid again.
6586 			 */
6587 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6588 			    (sbi->s_mount_state & EXT4_VALID_FS))
6589 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6590 
6591 			if (sbi->s_journal) {
6592 				/*
6593 				 * We let remount-ro finish even if marking fs
6594 				 * as clean failed...
6595 				 */
6596 				ext4_mark_recovery_complete(sb, es);
6597 			}
6598 		} else {
6599 			/* Make sure we can mount this feature set readwrite */
6600 			if (ext4_has_feature_readonly(sb) ||
6601 			    !ext4_feature_set_ok(sb, 0)) {
6602 				err = -EROFS;
6603 				goto restore_opts;
6604 			}
6605 			/*
6606 			 * Make sure the group descriptor checksums
6607 			 * are sane.  If they aren't, refuse to remount r/w.
6608 			 */
6609 			for (g = 0; g < sbi->s_groups_count; g++) {
6610 				struct ext4_group_desc *gdp =
6611 					ext4_get_group_desc(sb, g, NULL);
6612 
6613 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6614 					ext4_msg(sb, KERN_ERR,
6615 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6616 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6617 					       le16_to_cpu(gdp->bg_checksum));
6618 					err = -EFSBADCRC;
6619 					goto restore_opts;
6620 				}
6621 			}
6622 
6623 			/*
6624 			 * If we have an unprocessed orphan list hanging
6625 			 * around from a previously readonly bdev mount,
6626 			 * require a full umount/remount for now.
6627 			 */
6628 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6629 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6630 				       "remount RDWR because of unprocessed "
6631 				       "orphan inode list.  Please "
6632 				       "umount/remount instead");
6633 				err = -EINVAL;
6634 				goto restore_opts;
6635 			}
6636 
6637 			/*
6638 			 * Mounting a RDONLY partition read-write, so reread
6639 			 * and store the current valid flag.  (It may have
6640 			 * been changed by e2fsck since we originally mounted
6641 			 * the partition.)
6642 			 */
6643 			if (sbi->s_journal) {
6644 				err = ext4_clear_journal_err(sb, es);
6645 				if (err)
6646 					goto restore_opts;
6647 			}
6648 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6649 					      ~EXT4_FC_REPLAY);
6650 
6651 			err = ext4_setup_super(sb, es, 0);
6652 			if (err)
6653 				goto restore_opts;
6654 
6655 			sb->s_flags &= ~SB_RDONLY;
6656 			if (ext4_has_feature_mmp(sb)) {
6657 				err = ext4_multi_mount_protect(sb,
6658 						le64_to_cpu(es->s_mmp_block));
6659 				if (err)
6660 					goto restore_opts;
6661 			}
6662 #ifdef CONFIG_QUOTA
6663 			enable_quota = 1;
6664 #endif
6665 		}
6666 	}
6667 
6668 	/*
6669 	 * Handle creation of system zone data early because it can fail.
6670 	 * Releasing of existing data is done when we are sure remount will
6671 	 * succeed.
6672 	 */
6673 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6674 		err = ext4_setup_system_zone(sb);
6675 		if (err)
6676 			goto restore_opts;
6677 	}
6678 
6679 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6680 		err = ext4_commit_super(sb);
6681 		if (err)
6682 			goto restore_opts;
6683 	}
6684 
6685 #ifdef CONFIG_QUOTA
6686 	if (enable_quota) {
6687 		if (sb_any_quota_suspended(sb))
6688 			dquot_resume(sb, -1);
6689 		else if (ext4_has_feature_quota(sb)) {
6690 			err = ext4_enable_quotas(sb);
6691 			if (err)
6692 				goto restore_opts;
6693 		}
6694 	}
6695 	/* Release old quota file names */
6696 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6697 		kfree(old_opts.s_qf_names[i]);
6698 #endif
6699 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6700 		ext4_release_system_zone(sb);
6701 
6702 	/*
6703 	 * Reinitialize lazy itable initialization thread based on
6704 	 * current settings
6705 	 */
6706 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6707 		ext4_unregister_li_request(sb);
6708 	else {
6709 		ext4_group_t first_not_zeroed;
6710 		first_not_zeroed = ext4_has_uninit_itable(sb);
6711 		ext4_register_li_request(sb, first_not_zeroed);
6712 	}
6713 
6714 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6715 		ext4_stop_mmpd(sbi);
6716 
6717 	return 0;
6718 
6719 restore_opts:
6720 	/*
6721 	 * If there was a failing r/w to ro transition, we may need to
6722 	 * re-enable quota
6723 	 */
6724 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6725 	    sb_any_quota_suspended(sb))
6726 		dquot_resume(sb, -1);
6727 
6728 	alloc_ctx = ext4_writepages_down_write(sb);
6729 	sb->s_flags = old_sb_flags;
6730 	sbi->s_mount_opt = old_opts.s_mount_opt;
6731 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6732 	sbi->s_resuid = old_opts.s_resuid;
6733 	sbi->s_resgid = old_opts.s_resgid;
6734 	sbi->s_commit_interval = old_opts.s_commit_interval;
6735 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6736 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6737 	ext4_writepages_up_write(sb, alloc_ctx);
6738 
6739 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6740 		ext4_release_system_zone(sb);
6741 #ifdef CONFIG_QUOTA
6742 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6743 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6744 		to_free[i] = get_qf_name(sb, sbi, i);
6745 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6746 	}
6747 	synchronize_rcu();
6748 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6749 		kfree(to_free[i]);
6750 #endif
6751 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6752 		ext4_stop_mmpd(sbi);
6753 	return err;
6754 }
6755 
6756 static int ext4_reconfigure(struct fs_context *fc)
6757 {
6758 	struct super_block *sb = fc->root->d_sb;
6759 	int ret;
6760 
6761 	fc->s_fs_info = EXT4_SB(sb);
6762 
6763 	ret = ext4_check_opt_consistency(fc, sb);
6764 	if (ret < 0)
6765 		return ret;
6766 
6767 	ret = __ext4_remount(fc, sb);
6768 	if (ret < 0)
6769 		return ret;
6770 
6771 	ext4_msg(sb, KERN_INFO, "re-mounted %pU %s. Quota mode: %s.",
6772 		 &sb->s_uuid, sb_rdonly(sb) ? "ro" : "r/w",
6773 		 ext4_quota_mode(sb));
6774 
6775 	return 0;
6776 }
6777 
6778 #ifdef CONFIG_QUOTA
6779 static int ext4_statfs_project(struct super_block *sb,
6780 			       kprojid_t projid, struct kstatfs *buf)
6781 {
6782 	struct kqid qid;
6783 	struct dquot *dquot;
6784 	u64 limit;
6785 	u64 curblock;
6786 
6787 	qid = make_kqid_projid(projid);
6788 	dquot = dqget(sb, qid);
6789 	if (IS_ERR(dquot))
6790 		return PTR_ERR(dquot);
6791 	spin_lock(&dquot->dq_dqb_lock);
6792 
6793 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6794 			     dquot->dq_dqb.dqb_bhardlimit);
6795 	limit >>= sb->s_blocksize_bits;
6796 
6797 	if (limit && buf->f_blocks > limit) {
6798 		curblock = (dquot->dq_dqb.dqb_curspace +
6799 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6800 		buf->f_blocks = limit;
6801 		buf->f_bfree = buf->f_bavail =
6802 			(buf->f_blocks > curblock) ?
6803 			 (buf->f_blocks - curblock) : 0;
6804 	}
6805 
6806 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6807 			     dquot->dq_dqb.dqb_ihardlimit);
6808 	if (limit && buf->f_files > limit) {
6809 		buf->f_files = limit;
6810 		buf->f_ffree =
6811 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6812 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6813 	}
6814 
6815 	spin_unlock(&dquot->dq_dqb_lock);
6816 	dqput(dquot);
6817 	return 0;
6818 }
6819 #endif
6820 
6821 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6822 {
6823 	struct super_block *sb = dentry->d_sb;
6824 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6825 	struct ext4_super_block *es = sbi->s_es;
6826 	ext4_fsblk_t overhead = 0, resv_blocks;
6827 	s64 bfree;
6828 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6829 
6830 	if (!test_opt(sb, MINIX_DF))
6831 		overhead = sbi->s_overhead;
6832 
6833 	buf->f_type = EXT4_SUPER_MAGIC;
6834 	buf->f_bsize = sb->s_blocksize;
6835 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6836 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6837 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6838 	/* prevent underflow in case that few free space is available */
6839 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6840 	buf->f_bavail = buf->f_bfree -
6841 			(ext4_r_blocks_count(es) + resv_blocks);
6842 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6843 		buf->f_bavail = 0;
6844 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6845 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6846 	buf->f_namelen = EXT4_NAME_LEN;
6847 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6848 
6849 #ifdef CONFIG_QUOTA
6850 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6851 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6852 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6853 #endif
6854 	return 0;
6855 }
6856 
6857 
6858 #ifdef CONFIG_QUOTA
6859 
6860 /*
6861  * Helper functions so that transaction is started before we acquire dqio_sem
6862  * to keep correct lock ordering of transaction > dqio_sem
6863  */
6864 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6865 {
6866 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6867 }
6868 
6869 static int ext4_write_dquot(struct dquot *dquot)
6870 {
6871 	int ret, err;
6872 	handle_t *handle;
6873 	struct inode *inode;
6874 
6875 	inode = dquot_to_inode(dquot);
6876 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6877 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6878 	if (IS_ERR(handle))
6879 		return PTR_ERR(handle);
6880 	ret = dquot_commit(dquot);
6881 	if (ret < 0)
6882 		ext4_error_err(dquot->dq_sb, -ret,
6883 			       "Failed to commit dquot type %d",
6884 			       dquot->dq_id.type);
6885 	err = ext4_journal_stop(handle);
6886 	if (!ret)
6887 		ret = err;
6888 	return ret;
6889 }
6890 
6891 static int ext4_acquire_dquot(struct dquot *dquot)
6892 {
6893 	int ret, err;
6894 	handle_t *handle;
6895 
6896 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6897 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6898 	if (IS_ERR(handle))
6899 		return PTR_ERR(handle);
6900 	ret = dquot_acquire(dquot);
6901 	if (ret < 0)
6902 		ext4_error_err(dquot->dq_sb, -ret,
6903 			      "Failed to acquire dquot type %d",
6904 			      dquot->dq_id.type);
6905 	err = ext4_journal_stop(handle);
6906 	if (!ret)
6907 		ret = err;
6908 	return ret;
6909 }
6910 
6911 static int ext4_release_dquot(struct dquot *dquot)
6912 {
6913 	int ret, err;
6914 	handle_t *handle;
6915 
6916 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6917 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6918 	if (IS_ERR(handle)) {
6919 		/* Release dquot anyway to avoid endless cycle in dqput() */
6920 		dquot_release(dquot);
6921 		return PTR_ERR(handle);
6922 	}
6923 	ret = dquot_release(dquot);
6924 	if (ret < 0)
6925 		ext4_error_err(dquot->dq_sb, -ret,
6926 			       "Failed to release dquot type %d",
6927 			       dquot->dq_id.type);
6928 	err = ext4_journal_stop(handle);
6929 	if (!ret)
6930 		ret = err;
6931 	return ret;
6932 }
6933 
6934 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6935 {
6936 	struct super_block *sb = dquot->dq_sb;
6937 
6938 	if (ext4_is_quota_journalled(sb)) {
6939 		dquot_mark_dquot_dirty(dquot);
6940 		return ext4_write_dquot(dquot);
6941 	} else {
6942 		return dquot_mark_dquot_dirty(dquot);
6943 	}
6944 }
6945 
6946 static int ext4_write_info(struct super_block *sb, int type)
6947 {
6948 	int ret, err;
6949 	handle_t *handle;
6950 
6951 	/* Data block + inode block */
6952 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6953 	if (IS_ERR(handle))
6954 		return PTR_ERR(handle);
6955 	ret = dquot_commit_info(sb, type);
6956 	err = ext4_journal_stop(handle);
6957 	if (!ret)
6958 		ret = err;
6959 	return ret;
6960 }
6961 
6962 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6963 {
6964 	struct ext4_inode_info *ei = EXT4_I(inode);
6965 
6966 	/* The first argument of lockdep_set_subclass has to be
6967 	 * *exactly* the same as the argument to init_rwsem() --- in
6968 	 * this case, in init_once() --- or lockdep gets unhappy
6969 	 * because the name of the lock is set using the
6970 	 * stringification of the argument to init_rwsem().
6971 	 */
6972 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6973 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6974 }
6975 
6976 /*
6977  * Standard function to be called on quota_on
6978  */
6979 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6980 			 const struct path *path)
6981 {
6982 	int err;
6983 
6984 	if (!test_opt(sb, QUOTA))
6985 		return -EINVAL;
6986 
6987 	/* Quotafile not on the same filesystem? */
6988 	if (path->dentry->d_sb != sb)
6989 		return -EXDEV;
6990 
6991 	/* Quota already enabled for this file? */
6992 	if (IS_NOQUOTA(d_inode(path->dentry)))
6993 		return -EBUSY;
6994 
6995 	/* Journaling quota? */
6996 	if (EXT4_SB(sb)->s_qf_names[type]) {
6997 		/* Quotafile not in fs root? */
6998 		if (path->dentry->d_parent != sb->s_root)
6999 			ext4_msg(sb, KERN_WARNING,
7000 				"Quota file not on filesystem root. "
7001 				"Journaled quota will not work");
7002 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
7003 	} else {
7004 		/*
7005 		 * Clear the flag just in case mount options changed since
7006 		 * last time.
7007 		 */
7008 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
7009 	}
7010 
7011 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
7012 	err = dquot_quota_on(sb, type, format_id, path);
7013 	if (!err) {
7014 		struct inode *inode = d_inode(path->dentry);
7015 		handle_t *handle;
7016 
7017 		/*
7018 		 * Set inode flags to prevent userspace from messing with quota
7019 		 * files. If this fails, we return success anyway since quotas
7020 		 * are already enabled and this is not a hard failure.
7021 		 */
7022 		inode_lock(inode);
7023 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7024 		if (IS_ERR(handle))
7025 			goto unlock_inode;
7026 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
7027 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
7028 				S_NOATIME | S_IMMUTABLE);
7029 		err = ext4_mark_inode_dirty(handle, inode);
7030 		ext4_journal_stop(handle);
7031 	unlock_inode:
7032 		inode_unlock(inode);
7033 		if (err)
7034 			dquot_quota_off(sb, type);
7035 	}
7036 	if (err)
7037 		lockdep_set_quota_inode(path->dentry->d_inode,
7038 					     I_DATA_SEM_NORMAL);
7039 	return err;
7040 }
7041 
7042 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
7043 {
7044 	switch (type) {
7045 	case USRQUOTA:
7046 		return qf_inum == EXT4_USR_QUOTA_INO;
7047 	case GRPQUOTA:
7048 		return qf_inum == EXT4_GRP_QUOTA_INO;
7049 	case PRJQUOTA:
7050 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7051 	default:
7052 		BUG();
7053 	}
7054 }
7055 
7056 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7057 			     unsigned int flags)
7058 {
7059 	int err;
7060 	struct inode *qf_inode;
7061 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7062 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7063 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7064 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7065 	};
7066 
7067 	BUG_ON(!ext4_has_feature_quota(sb));
7068 
7069 	if (!qf_inums[type])
7070 		return -EPERM;
7071 
7072 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7073 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7074 				qf_inums[type], type);
7075 		return -EUCLEAN;
7076 	}
7077 
7078 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7079 	if (IS_ERR(qf_inode)) {
7080 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7081 				qf_inums[type], type);
7082 		return PTR_ERR(qf_inode);
7083 	}
7084 
7085 	/* Don't account quota for quota files to avoid recursion */
7086 	qf_inode->i_flags |= S_NOQUOTA;
7087 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7088 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7089 	if (err)
7090 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7091 	iput(qf_inode);
7092 
7093 	return err;
7094 }
7095 
7096 /* Enable usage tracking for all quota types. */
7097 int ext4_enable_quotas(struct super_block *sb)
7098 {
7099 	int type, err = 0;
7100 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7101 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7102 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7103 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7104 	};
7105 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7106 		test_opt(sb, USRQUOTA),
7107 		test_opt(sb, GRPQUOTA),
7108 		test_opt(sb, PRJQUOTA),
7109 	};
7110 
7111 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7112 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7113 		if (qf_inums[type]) {
7114 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7115 				DQUOT_USAGE_ENABLED |
7116 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7117 			if (err) {
7118 				ext4_warning(sb,
7119 					"Failed to enable quota tracking "
7120 					"(type=%d, err=%d, ino=%lu). "
7121 					"Please run e2fsck to fix.", type,
7122 					err, qf_inums[type]);
7123 
7124 				ext4_quotas_off(sb, type);
7125 				return err;
7126 			}
7127 		}
7128 	}
7129 	return 0;
7130 }
7131 
7132 static int ext4_quota_off(struct super_block *sb, int type)
7133 {
7134 	struct inode *inode = sb_dqopt(sb)->files[type];
7135 	handle_t *handle;
7136 	int err;
7137 
7138 	/* Force all delayed allocation blocks to be allocated.
7139 	 * Caller already holds s_umount sem */
7140 	if (test_opt(sb, DELALLOC))
7141 		sync_filesystem(sb);
7142 
7143 	if (!inode || !igrab(inode))
7144 		goto out;
7145 
7146 	err = dquot_quota_off(sb, type);
7147 	if (err || ext4_has_feature_quota(sb))
7148 		goto out_put;
7149 	/*
7150 	 * When the filesystem was remounted read-only first, we cannot cleanup
7151 	 * inode flags here. Bad luck but people should be using QUOTA feature
7152 	 * these days anyway.
7153 	 */
7154 	if (sb_rdonly(sb))
7155 		goto out_put;
7156 
7157 	inode_lock(inode);
7158 	/*
7159 	 * Update modification times of quota files when userspace can
7160 	 * start looking at them. If we fail, we return success anyway since
7161 	 * this is not a hard failure and quotas are already disabled.
7162 	 */
7163 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7164 	if (IS_ERR(handle)) {
7165 		err = PTR_ERR(handle);
7166 		goto out_unlock;
7167 	}
7168 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7169 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7170 	inode->i_mtime = inode_set_ctime_current(inode);
7171 	err = ext4_mark_inode_dirty(handle, inode);
7172 	ext4_journal_stop(handle);
7173 out_unlock:
7174 	inode_unlock(inode);
7175 out_put:
7176 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7177 	iput(inode);
7178 	return err;
7179 out:
7180 	return dquot_quota_off(sb, type);
7181 }
7182 
7183 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7184  * acquiring the locks... As quota files are never truncated and quota code
7185  * itself serializes the operations (and no one else should touch the files)
7186  * we don't have to be afraid of races */
7187 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7188 			       size_t len, loff_t off)
7189 {
7190 	struct inode *inode = sb_dqopt(sb)->files[type];
7191 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7192 	int offset = off & (sb->s_blocksize - 1);
7193 	int tocopy;
7194 	size_t toread;
7195 	struct buffer_head *bh;
7196 	loff_t i_size = i_size_read(inode);
7197 
7198 	if (off > i_size)
7199 		return 0;
7200 	if (off+len > i_size)
7201 		len = i_size-off;
7202 	toread = len;
7203 	while (toread > 0) {
7204 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7205 		bh = ext4_bread(NULL, inode, blk, 0);
7206 		if (IS_ERR(bh))
7207 			return PTR_ERR(bh);
7208 		if (!bh)	/* A hole? */
7209 			memset(data, 0, tocopy);
7210 		else
7211 			memcpy(data, bh->b_data+offset, tocopy);
7212 		brelse(bh);
7213 		offset = 0;
7214 		toread -= tocopy;
7215 		data += tocopy;
7216 		blk++;
7217 	}
7218 	return len;
7219 }
7220 
7221 /* Write to quotafile (we know the transaction is already started and has
7222  * enough credits) */
7223 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7224 				const char *data, size_t len, loff_t off)
7225 {
7226 	struct inode *inode = sb_dqopt(sb)->files[type];
7227 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7228 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7229 	int retries = 0;
7230 	struct buffer_head *bh;
7231 	handle_t *handle = journal_current_handle();
7232 
7233 	if (!handle) {
7234 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7235 			" cancelled because transaction is not started",
7236 			(unsigned long long)off, (unsigned long long)len);
7237 		return -EIO;
7238 	}
7239 	/*
7240 	 * Since we account only one data block in transaction credits,
7241 	 * then it is impossible to cross a block boundary.
7242 	 */
7243 	if (sb->s_blocksize - offset < len) {
7244 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7245 			" cancelled because not block aligned",
7246 			(unsigned long long)off, (unsigned long long)len);
7247 		return -EIO;
7248 	}
7249 
7250 	do {
7251 		bh = ext4_bread(handle, inode, blk,
7252 				EXT4_GET_BLOCKS_CREATE |
7253 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7254 	} while (PTR_ERR(bh) == -ENOSPC &&
7255 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7256 	if (IS_ERR(bh))
7257 		return PTR_ERR(bh);
7258 	if (!bh)
7259 		goto out;
7260 	BUFFER_TRACE(bh, "get write access");
7261 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7262 	if (err) {
7263 		brelse(bh);
7264 		return err;
7265 	}
7266 	lock_buffer(bh);
7267 	memcpy(bh->b_data+offset, data, len);
7268 	flush_dcache_page(bh->b_page);
7269 	unlock_buffer(bh);
7270 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7271 	brelse(bh);
7272 out:
7273 	if (inode->i_size < off + len) {
7274 		i_size_write(inode, off + len);
7275 		EXT4_I(inode)->i_disksize = inode->i_size;
7276 		err2 = ext4_mark_inode_dirty(handle, inode);
7277 		if (unlikely(err2 && !err))
7278 			err = err2;
7279 	}
7280 	return err ? err : len;
7281 }
7282 #endif
7283 
7284 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7285 static inline void register_as_ext2(void)
7286 {
7287 	int err = register_filesystem(&ext2_fs_type);
7288 	if (err)
7289 		printk(KERN_WARNING
7290 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7291 }
7292 
7293 static inline void unregister_as_ext2(void)
7294 {
7295 	unregister_filesystem(&ext2_fs_type);
7296 }
7297 
7298 static inline int ext2_feature_set_ok(struct super_block *sb)
7299 {
7300 	if (ext4_has_unknown_ext2_incompat_features(sb))
7301 		return 0;
7302 	if (sb_rdonly(sb))
7303 		return 1;
7304 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7305 		return 0;
7306 	return 1;
7307 }
7308 #else
7309 static inline void register_as_ext2(void) { }
7310 static inline void unregister_as_ext2(void) { }
7311 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7312 #endif
7313 
7314 static inline void register_as_ext3(void)
7315 {
7316 	int err = register_filesystem(&ext3_fs_type);
7317 	if (err)
7318 		printk(KERN_WARNING
7319 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7320 }
7321 
7322 static inline void unregister_as_ext3(void)
7323 {
7324 	unregister_filesystem(&ext3_fs_type);
7325 }
7326 
7327 static inline int ext3_feature_set_ok(struct super_block *sb)
7328 {
7329 	if (ext4_has_unknown_ext3_incompat_features(sb))
7330 		return 0;
7331 	if (!ext4_has_feature_journal(sb))
7332 		return 0;
7333 	if (sb_rdonly(sb))
7334 		return 1;
7335 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7336 		return 0;
7337 	return 1;
7338 }
7339 
7340 static void ext4_kill_sb(struct super_block *sb)
7341 {
7342 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7343 	struct block_device *journal_bdev = sbi ? sbi->s_journal_bdev : NULL;
7344 
7345 	kill_block_super(sb);
7346 
7347 	if (journal_bdev)
7348 		blkdev_put(journal_bdev, sb);
7349 }
7350 
7351 static struct file_system_type ext4_fs_type = {
7352 	.owner			= THIS_MODULE,
7353 	.name			= "ext4",
7354 	.init_fs_context	= ext4_init_fs_context,
7355 	.parameters		= ext4_param_specs,
7356 	.kill_sb		= ext4_kill_sb,
7357 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7358 };
7359 MODULE_ALIAS_FS("ext4");
7360 
7361 /* Shared across all ext4 file systems */
7362 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7363 
7364 static int __init ext4_init_fs(void)
7365 {
7366 	int i, err;
7367 
7368 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7369 	ext4_li_info = NULL;
7370 
7371 	/* Build-time check for flags consistency */
7372 	ext4_check_flag_values();
7373 
7374 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7375 		init_waitqueue_head(&ext4__ioend_wq[i]);
7376 
7377 	err = ext4_init_es();
7378 	if (err)
7379 		return err;
7380 
7381 	err = ext4_init_pending();
7382 	if (err)
7383 		goto out7;
7384 
7385 	err = ext4_init_post_read_processing();
7386 	if (err)
7387 		goto out6;
7388 
7389 	err = ext4_init_pageio();
7390 	if (err)
7391 		goto out5;
7392 
7393 	err = ext4_init_system_zone();
7394 	if (err)
7395 		goto out4;
7396 
7397 	err = ext4_init_sysfs();
7398 	if (err)
7399 		goto out3;
7400 
7401 	err = ext4_init_mballoc();
7402 	if (err)
7403 		goto out2;
7404 	err = init_inodecache();
7405 	if (err)
7406 		goto out1;
7407 
7408 	err = ext4_fc_init_dentry_cache();
7409 	if (err)
7410 		goto out05;
7411 
7412 	register_as_ext3();
7413 	register_as_ext2();
7414 	err = register_filesystem(&ext4_fs_type);
7415 	if (err)
7416 		goto out;
7417 
7418 	return 0;
7419 out:
7420 	unregister_as_ext2();
7421 	unregister_as_ext3();
7422 	ext4_fc_destroy_dentry_cache();
7423 out05:
7424 	destroy_inodecache();
7425 out1:
7426 	ext4_exit_mballoc();
7427 out2:
7428 	ext4_exit_sysfs();
7429 out3:
7430 	ext4_exit_system_zone();
7431 out4:
7432 	ext4_exit_pageio();
7433 out5:
7434 	ext4_exit_post_read_processing();
7435 out6:
7436 	ext4_exit_pending();
7437 out7:
7438 	ext4_exit_es();
7439 
7440 	return err;
7441 }
7442 
7443 static void __exit ext4_exit_fs(void)
7444 {
7445 	ext4_destroy_lazyinit_thread();
7446 	unregister_as_ext2();
7447 	unregister_as_ext3();
7448 	unregister_filesystem(&ext4_fs_type);
7449 	ext4_fc_destroy_dentry_cache();
7450 	destroy_inodecache();
7451 	ext4_exit_mballoc();
7452 	ext4_exit_sysfs();
7453 	ext4_exit_system_zone();
7454 	ext4_exit_pageio();
7455 	ext4_exit_post_read_processing();
7456 	ext4_exit_es();
7457 	ext4_exit_pending();
7458 }
7459 
7460 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7461 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7462 MODULE_LICENSE("GPL");
7463 MODULE_SOFTDEP("pre: crc32c");
7464 module_init(ext4_init_fs)
7465 module_exit(ext4_exit_fs)
7466