xref: /linux/fs/ext4/super.c (revision f4738f56d1dc62aaba69b33702a5ab098f1b8c63)
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;
772 		handle = jbd2_journal_start(journal, 1);
773 		if (IS_ERR(handle))
774 			goto write_directly;
775 		if (jbd2_journal_get_write_access(handle, sbh)) {
776 			jbd2_journal_stop(handle);
777 			goto write_directly;
778 		}
779 
780 		if (sbi->s_add_error_count > 0)
781 			call_notify_err = true;
782 
783 		ext4_update_super(sbi->s_sb);
784 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
785 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
786 				 "superblock detected");
787 			clear_buffer_write_io_error(sbh);
788 			set_buffer_uptodate(sbh);
789 		}
790 
791 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
792 			jbd2_journal_stop(handle);
793 			goto write_directly;
794 		}
795 		jbd2_journal_stop(handle);
796 
797 		if (call_notify_err)
798 			ext4_notify_error_sysfs(sbi);
799 
800 		return;
801 	}
802 write_directly:
803 	/*
804 	 * Write through journal failed. Write sb directly to get error info
805 	 * out and hope for the best.
806 	 */
807 	ext4_commit_super(sbi->s_sb);
808 	ext4_notify_error_sysfs(sbi);
809 }
810 
811 #define ext4_error_ratelimit(sb)					\
812 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
813 			     "EXT4-fs error")
814 
815 void __ext4_error(struct super_block *sb, const char *function,
816 		  unsigned int line, bool force_ro, int error, __u64 block,
817 		  const char *fmt, ...)
818 {
819 	struct va_format vaf;
820 	va_list args;
821 
822 	if (unlikely(ext4_forced_shutdown(sb)))
823 		return;
824 
825 	trace_ext4_error(sb, function, line);
826 	if (ext4_error_ratelimit(sb)) {
827 		va_start(args, fmt);
828 		vaf.fmt = fmt;
829 		vaf.va = &args;
830 		printk(KERN_CRIT
831 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
832 		       sb->s_id, function, line, current->comm, &vaf);
833 		va_end(args);
834 	}
835 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
836 
837 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
838 }
839 
840 void __ext4_error_inode(struct inode *inode, const char *function,
841 			unsigned int line, ext4_fsblk_t block, int error,
842 			const char *fmt, ...)
843 {
844 	va_list args;
845 	struct va_format vaf;
846 
847 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
848 		return;
849 
850 	trace_ext4_error(inode->i_sb, function, line);
851 	if (ext4_error_ratelimit(inode->i_sb)) {
852 		va_start(args, fmt);
853 		vaf.fmt = fmt;
854 		vaf.va = &args;
855 		if (block)
856 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
857 			       "inode #%lu: block %llu: comm %s: %pV\n",
858 			       inode->i_sb->s_id, function, line, inode->i_ino,
859 			       block, current->comm, &vaf);
860 		else
861 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
862 			       "inode #%lu: comm %s: %pV\n",
863 			       inode->i_sb->s_id, function, line, inode->i_ino,
864 			       current->comm, &vaf);
865 		va_end(args);
866 	}
867 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
868 
869 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
870 			  function, line);
871 }
872 
873 void __ext4_error_file(struct file *file, const char *function,
874 		       unsigned int line, ext4_fsblk_t block,
875 		       const char *fmt, ...)
876 {
877 	va_list args;
878 	struct va_format vaf;
879 	struct inode *inode = file_inode(file);
880 	char pathname[80], *path;
881 
882 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
883 		return;
884 
885 	trace_ext4_error(inode->i_sb, function, line);
886 	if (ext4_error_ratelimit(inode->i_sb)) {
887 		path = file_path(file, pathname, sizeof(pathname));
888 		if (IS_ERR(path))
889 			path = "(unknown)";
890 		va_start(args, fmt);
891 		vaf.fmt = fmt;
892 		vaf.va = &args;
893 		if (block)
894 			printk(KERN_CRIT
895 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
896 			       "block %llu: comm %s: path %s: %pV\n",
897 			       inode->i_sb->s_id, function, line, inode->i_ino,
898 			       block, current->comm, path, &vaf);
899 		else
900 			printk(KERN_CRIT
901 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
902 			       "comm %s: path %s: %pV\n",
903 			       inode->i_sb->s_id, function, line, inode->i_ino,
904 			       current->comm, path, &vaf);
905 		va_end(args);
906 	}
907 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
908 
909 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
910 			  function, line);
911 }
912 
913 const char *ext4_decode_error(struct super_block *sb, int errno,
914 			      char nbuf[16])
915 {
916 	char *errstr = NULL;
917 
918 	switch (errno) {
919 	case -EFSCORRUPTED:
920 		errstr = "Corrupt filesystem";
921 		break;
922 	case -EFSBADCRC:
923 		errstr = "Filesystem failed CRC";
924 		break;
925 	case -EIO:
926 		errstr = "IO failure";
927 		break;
928 	case -ENOMEM:
929 		errstr = "Out of memory";
930 		break;
931 	case -EROFS:
932 		if (!sb || (EXT4_SB(sb)->s_journal &&
933 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
934 			errstr = "Journal has aborted";
935 		else
936 			errstr = "Readonly filesystem";
937 		break;
938 	default:
939 		/* If the caller passed in an extra buffer for unknown
940 		 * errors, textualise them now.  Else we just return
941 		 * NULL. */
942 		if (nbuf) {
943 			/* Check for truncated error codes... */
944 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
945 				errstr = nbuf;
946 		}
947 		break;
948 	}
949 
950 	return errstr;
951 }
952 
953 /* __ext4_std_error decodes expected errors from journaling functions
954  * automatically and invokes the appropriate error response.  */
955 
956 void __ext4_std_error(struct super_block *sb, const char *function,
957 		      unsigned int line, int errno)
958 {
959 	char nbuf[16];
960 	const char *errstr;
961 
962 	if (unlikely(ext4_forced_shutdown(sb)))
963 		return;
964 
965 	/* Special case: if the error is EROFS, and we're not already
966 	 * inside a transaction, then there's really no point in logging
967 	 * an error. */
968 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
969 		return;
970 
971 	if (ext4_error_ratelimit(sb)) {
972 		errstr = ext4_decode_error(sb, errno, nbuf);
973 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
974 		       sb->s_id, function, line, errstr);
975 	}
976 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
977 
978 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
979 }
980 
981 void __ext4_msg(struct super_block *sb,
982 		const char *prefix, const char *fmt, ...)
983 {
984 	struct va_format vaf;
985 	va_list args;
986 
987 	if (sb) {
988 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
989 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
990 				  "EXT4-fs"))
991 			return;
992 	}
993 
994 	va_start(args, fmt);
995 	vaf.fmt = fmt;
996 	vaf.va = &args;
997 	if (sb)
998 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
999 	else
1000 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
1001 	va_end(args);
1002 }
1003 
1004 static int ext4_warning_ratelimit(struct super_block *sb)
1005 {
1006 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
1007 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1008 			    "EXT4-fs warning");
1009 }
1010 
1011 void __ext4_warning(struct super_block *sb, const char *function,
1012 		    unsigned int line, const char *fmt, ...)
1013 {
1014 	struct va_format vaf;
1015 	va_list args;
1016 
1017 	if (!ext4_warning_ratelimit(sb))
1018 		return;
1019 
1020 	va_start(args, fmt);
1021 	vaf.fmt = fmt;
1022 	vaf.va = &args;
1023 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1024 	       sb->s_id, function, line, &vaf);
1025 	va_end(args);
1026 }
1027 
1028 void __ext4_warning_inode(const struct inode *inode, const char *function,
1029 			  unsigned int line, const char *fmt, ...)
1030 {
1031 	struct va_format vaf;
1032 	va_list args;
1033 
1034 	if (!ext4_warning_ratelimit(inode->i_sb))
1035 		return;
1036 
1037 	va_start(args, fmt);
1038 	vaf.fmt = fmt;
1039 	vaf.va = &args;
1040 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1041 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
1042 	       function, line, inode->i_ino, current->comm, &vaf);
1043 	va_end(args);
1044 }
1045 
1046 void __ext4_grp_locked_error(const char *function, unsigned int line,
1047 			     struct super_block *sb, ext4_group_t grp,
1048 			     unsigned long ino, ext4_fsblk_t block,
1049 			     const char *fmt, ...)
1050 __releases(bitlock)
1051 __acquires(bitlock)
1052 {
1053 	struct va_format vaf;
1054 	va_list args;
1055 
1056 	if (unlikely(ext4_forced_shutdown(sb)))
1057 		return;
1058 
1059 	trace_ext4_error(sb, function, line);
1060 	if (ext4_error_ratelimit(sb)) {
1061 		va_start(args, fmt);
1062 		vaf.fmt = fmt;
1063 		vaf.va = &args;
1064 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1065 		       sb->s_id, function, line, grp);
1066 		if (ino)
1067 			printk(KERN_CONT "inode %lu: ", ino);
1068 		if (block)
1069 			printk(KERN_CONT "block %llu:",
1070 			       (unsigned long long) block);
1071 		printk(KERN_CONT "%pV\n", &vaf);
1072 		va_end(args);
1073 	}
1074 
1075 	if (test_opt(sb, ERRORS_CONT)) {
1076 		if (test_opt(sb, WARN_ON_ERROR))
1077 			WARN_ON_ONCE(1);
1078 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1079 		if (!bdev_read_only(sb->s_bdev)) {
1080 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1081 					line);
1082 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1083 		}
1084 		return;
1085 	}
1086 	ext4_unlock_group(sb, grp);
1087 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1088 	/*
1089 	 * We only get here in the ERRORS_RO case; relocking the group
1090 	 * may be dangerous, but nothing bad will happen since the
1091 	 * filesystem will have already been marked read/only and the
1092 	 * journal has been aborted.  We return 1 as a hint to callers
1093 	 * who might what to use the return value from
1094 	 * ext4_grp_locked_error() to distinguish between the
1095 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1096 	 * aggressively from the ext4 function in question, with a
1097 	 * more appropriate error code.
1098 	 */
1099 	ext4_lock_group(sb, grp);
1100 	return;
1101 }
1102 
1103 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1104 				     ext4_group_t group,
1105 				     unsigned int flags)
1106 {
1107 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1108 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1109 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1110 	int ret;
1111 
1112 	if (!grp || !gdp)
1113 		return;
1114 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1115 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1116 					    &grp->bb_state);
1117 		if (!ret)
1118 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1119 					   grp->bb_free);
1120 	}
1121 
1122 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1123 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1124 					    &grp->bb_state);
1125 		if (!ret && gdp) {
1126 			int count;
1127 
1128 			count = ext4_free_inodes_count(sb, gdp);
1129 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1130 					   count);
1131 		}
1132 	}
1133 }
1134 
1135 void ext4_update_dynamic_rev(struct super_block *sb)
1136 {
1137 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1138 
1139 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1140 		return;
1141 
1142 	ext4_warning(sb,
1143 		     "updating to rev %d because of new feature flag, "
1144 		     "running e2fsck is recommended",
1145 		     EXT4_DYNAMIC_REV);
1146 
1147 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1148 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1149 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1150 	/* leave es->s_feature_*compat flags alone */
1151 	/* es->s_uuid will be set by e2fsck if empty */
1152 
1153 	/*
1154 	 * The rest of the superblock fields should be zero, and if not it
1155 	 * means they are likely already in use, so leave them alone.  We
1156 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1157 	 */
1158 }
1159 
1160 static inline struct inode *orphan_list_entry(struct list_head *l)
1161 {
1162 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1163 }
1164 
1165 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1166 {
1167 	struct list_head *l;
1168 
1169 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1170 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1171 
1172 	printk(KERN_ERR "sb_info orphan list:\n");
1173 	list_for_each(l, &sbi->s_orphan) {
1174 		struct inode *inode = orphan_list_entry(l);
1175 		printk(KERN_ERR "  "
1176 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1177 		       inode->i_sb->s_id, inode->i_ino, inode,
1178 		       inode->i_mode, inode->i_nlink,
1179 		       NEXT_ORPHAN(inode));
1180 	}
1181 }
1182 
1183 #ifdef CONFIG_QUOTA
1184 static int ext4_quota_off(struct super_block *sb, int type);
1185 
1186 static inline void ext4_quotas_off(struct super_block *sb, int type)
1187 {
1188 	BUG_ON(type > EXT4_MAXQUOTAS);
1189 
1190 	/* Use our quota_off function to clear inode flags etc. */
1191 	for (type--; type >= 0; type--)
1192 		ext4_quota_off(sb, type);
1193 }
1194 
1195 /*
1196  * This is a helper function which is used in the mount/remount
1197  * codepaths (which holds s_umount) to fetch the quota file name.
1198  */
1199 static inline char *get_qf_name(struct super_block *sb,
1200 				struct ext4_sb_info *sbi,
1201 				int type)
1202 {
1203 	return rcu_dereference_protected(sbi->s_qf_names[type],
1204 					 lockdep_is_held(&sb->s_umount));
1205 }
1206 #else
1207 static inline void ext4_quotas_off(struct super_block *sb, int type)
1208 {
1209 }
1210 #endif
1211 
1212 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1213 {
1214 	ext4_fsblk_t block;
1215 	int err;
1216 
1217 	block = ext4_count_free_clusters(sbi->s_sb);
1218 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1219 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1220 				  GFP_KERNEL);
1221 	if (!err) {
1222 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1223 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1224 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1225 					  GFP_KERNEL);
1226 	}
1227 	if (!err)
1228 		err = percpu_counter_init(&sbi->s_dirs_counter,
1229 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1230 	if (!err)
1231 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1232 					  GFP_KERNEL);
1233 	if (!err)
1234 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1235 					  GFP_KERNEL);
1236 	if (!err)
1237 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1238 
1239 	if (err)
1240 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1241 
1242 	return err;
1243 }
1244 
1245 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1246 {
1247 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1248 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1249 	percpu_counter_destroy(&sbi->s_dirs_counter);
1250 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1251 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1252 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1253 }
1254 
1255 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1256 {
1257 	struct buffer_head **group_desc;
1258 	int i;
1259 
1260 	rcu_read_lock();
1261 	group_desc = rcu_dereference(sbi->s_group_desc);
1262 	for (i = 0; i < sbi->s_gdb_count; i++)
1263 		brelse(group_desc[i]);
1264 	kvfree(group_desc);
1265 	rcu_read_unlock();
1266 }
1267 
1268 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1269 {
1270 	struct flex_groups **flex_groups;
1271 	int i;
1272 
1273 	rcu_read_lock();
1274 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1275 	if (flex_groups) {
1276 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1277 			kvfree(flex_groups[i]);
1278 		kvfree(flex_groups);
1279 	}
1280 	rcu_read_unlock();
1281 }
1282 
1283 static void ext4_put_super(struct super_block *sb)
1284 {
1285 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1286 	struct ext4_super_block *es = sbi->s_es;
1287 	int aborted = 0;
1288 	int err;
1289 
1290 	/*
1291 	 * Unregister sysfs before destroying jbd2 journal.
1292 	 * Since we could still access attr_journal_task attribute via sysfs
1293 	 * path which could have sbi->s_journal->j_task as NULL
1294 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1295 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1296 	 * read metadata verify failed then will queue error work.
1297 	 * update_super_work will call start_this_handle may trigger
1298 	 * BUG_ON.
1299 	 */
1300 	ext4_unregister_sysfs(sb);
1301 
1302 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1303 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1304 			 &sb->s_uuid);
1305 
1306 	ext4_unregister_li_request(sb);
1307 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1308 
1309 	flush_work(&sbi->s_sb_upd_work);
1310 	destroy_workqueue(sbi->rsv_conversion_wq);
1311 	ext4_release_orphan_info(sb);
1312 
1313 	if (sbi->s_journal) {
1314 		aborted = is_journal_aborted(sbi->s_journal);
1315 		err = jbd2_journal_destroy(sbi->s_journal);
1316 		sbi->s_journal = NULL;
1317 		if ((err < 0) && !aborted) {
1318 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1319 		}
1320 	}
1321 
1322 	ext4_es_unregister_shrinker(sbi);
1323 	timer_shutdown_sync(&sbi->s_err_report);
1324 	ext4_release_system_zone(sb);
1325 	ext4_mb_release(sb);
1326 	ext4_ext_release(sb);
1327 
1328 	if (!sb_rdonly(sb) && !aborted) {
1329 		ext4_clear_feature_journal_needs_recovery(sb);
1330 		ext4_clear_feature_orphan_present(sb);
1331 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1332 	}
1333 	if (!sb_rdonly(sb))
1334 		ext4_commit_super(sb);
1335 
1336 	ext4_group_desc_free(sbi);
1337 	ext4_flex_groups_free(sbi);
1338 	ext4_percpu_param_destroy(sbi);
1339 #ifdef CONFIG_QUOTA
1340 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1341 		kfree(get_qf_name(sb, sbi, i));
1342 #endif
1343 
1344 	/* Debugging code just in case the in-memory inode orphan list
1345 	 * isn't empty.  The on-disk one can be non-empty if we've
1346 	 * detected an error and taken the fs readonly, but the
1347 	 * in-memory list had better be clean by this point. */
1348 	if (!list_empty(&sbi->s_orphan))
1349 		dump_orphan_list(sb, sbi);
1350 	ASSERT(list_empty(&sbi->s_orphan));
1351 
1352 	sync_blockdev(sb->s_bdev);
1353 	invalidate_bdev(sb->s_bdev);
1354 	if (sbi->s_journal_bdev) {
1355 		/*
1356 		 * Invalidate the journal device's buffers.  We don't want them
1357 		 * floating about in memory - the physical journal device may
1358 		 * hotswapped, and it breaks the `ro-after' testing code.
1359 		 */
1360 		sync_blockdev(sbi->s_journal_bdev);
1361 		invalidate_bdev(sbi->s_journal_bdev);
1362 	}
1363 
1364 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1365 	sbi->s_ea_inode_cache = NULL;
1366 
1367 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1368 	sbi->s_ea_block_cache = NULL;
1369 
1370 	ext4_stop_mmpd(sbi);
1371 
1372 	brelse(sbi->s_sbh);
1373 	sb->s_fs_info = NULL;
1374 	/*
1375 	 * Now that we are completely done shutting down the
1376 	 * superblock, we need to actually destroy the kobject.
1377 	 */
1378 	kobject_put(&sbi->s_kobj);
1379 	wait_for_completion(&sbi->s_kobj_unregister);
1380 	if (sbi->s_chksum_driver)
1381 		crypto_free_shash(sbi->s_chksum_driver);
1382 	kfree(sbi->s_blockgroup_lock);
1383 	fs_put_dax(sbi->s_daxdev, NULL);
1384 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1385 #if IS_ENABLED(CONFIG_UNICODE)
1386 	utf8_unload(sb->s_encoding);
1387 #endif
1388 	kfree(sbi);
1389 }
1390 
1391 static struct kmem_cache *ext4_inode_cachep;
1392 
1393 /*
1394  * Called inside transaction, so use GFP_NOFS
1395  */
1396 static struct inode *ext4_alloc_inode(struct super_block *sb)
1397 {
1398 	struct ext4_inode_info *ei;
1399 
1400 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1401 	if (!ei)
1402 		return NULL;
1403 
1404 	inode_set_iversion(&ei->vfs_inode, 1);
1405 	ei->i_flags = 0;
1406 	spin_lock_init(&ei->i_raw_lock);
1407 	ei->i_prealloc_node = RB_ROOT;
1408 	atomic_set(&ei->i_prealloc_active, 0);
1409 	rwlock_init(&ei->i_prealloc_lock);
1410 	ext4_es_init_tree(&ei->i_es_tree);
1411 	rwlock_init(&ei->i_es_lock);
1412 	INIT_LIST_HEAD(&ei->i_es_list);
1413 	ei->i_es_all_nr = 0;
1414 	ei->i_es_shk_nr = 0;
1415 	ei->i_es_shrink_lblk = 0;
1416 	ei->i_reserved_data_blocks = 0;
1417 	spin_lock_init(&(ei->i_block_reservation_lock));
1418 	ext4_init_pending_tree(&ei->i_pending_tree);
1419 #ifdef CONFIG_QUOTA
1420 	ei->i_reserved_quota = 0;
1421 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1422 #endif
1423 	ei->jinode = NULL;
1424 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1425 	spin_lock_init(&ei->i_completed_io_lock);
1426 	ei->i_sync_tid = 0;
1427 	ei->i_datasync_tid = 0;
1428 	atomic_set(&ei->i_unwritten, 0);
1429 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1430 	ext4_fc_init_inode(&ei->vfs_inode);
1431 	mutex_init(&ei->i_fc_lock);
1432 	return &ei->vfs_inode;
1433 }
1434 
1435 static int ext4_drop_inode(struct inode *inode)
1436 {
1437 	int drop = generic_drop_inode(inode);
1438 
1439 	if (!drop)
1440 		drop = fscrypt_drop_inode(inode);
1441 
1442 	trace_ext4_drop_inode(inode, drop);
1443 	return drop;
1444 }
1445 
1446 static void ext4_free_in_core_inode(struct inode *inode)
1447 {
1448 	fscrypt_free_inode(inode);
1449 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1450 		pr_warn("%s: inode %ld still in fc list",
1451 			__func__, inode->i_ino);
1452 	}
1453 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1454 }
1455 
1456 static void ext4_destroy_inode(struct inode *inode)
1457 {
1458 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1459 		ext4_msg(inode->i_sb, KERN_ERR,
1460 			 "Inode %lu (%p): orphan list check failed!",
1461 			 inode->i_ino, EXT4_I(inode));
1462 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1463 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1464 				true);
1465 		dump_stack();
1466 	}
1467 
1468 	if (EXT4_I(inode)->i_reserved_data_blocks)
1469 		ext4_msg(inode->i_sb, KERN_ERR,
1470 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1471 			 inode->i_ino, EXT4_I(inode),
1472 			 EXT4_I(inode)->i_reserved_data_blocks);
1473 }
1474 
1475 static void ext4_shutdown(struct super_block *sb)
1476 {
1477        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1478 }
1479 
1480 static void init_once(void *foo)
1481 {
1482 	struct ext4_inode_info *ei = foo;
1483 
1484 	INIT_LIST_HEAD(&ei->i_orphan);
1485 	init_rwsem(&ei->xattr_sem);
1486 	init_rwsem(&ei->i_data_sem);
1487 	inode_init_once(&ei->vfs_inode);
1488 	ext4_fc_init_inode(&ei->vfs_inode);
1489 }
1490 
1491 static int __init init_inodecache(void)
1492 {
1493 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1494 				sizeof(struct ext4_inode_info), 0,
1495 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1496 					SLAB_ACCOUNT),
1497 				offsetof(struct ext4_inode_info, i_data),
1498 				sizeof_field(struct ext4_inode_info, i_data),
1499 				init_once);
1500 	if (ext4_inode_cachep == NULL)
1501 		return -ENOMEM;
1502 	return 0;
1503 }
1504 
1505 static void destroy_inodecache(void)
1506 {
1507 	/*
1508 	 * Make sure all delayed rcu free inodes are flushed before we
1509 	 * destroy cache.
1510 	 */
1511 	rcu_barrier();
1512 	kmem_cache_destroy(ext4_inode_cachep);
1513 }
1514 
1515 void ext4_clear_inode(struct inode *inode)
1516 {
1517 	ext4_fc_del(inode);
1518 	invalidate_inode_buffers(inode);
1519 	clear_inode(inode);
1520 	ext4_discard_preallocations(inode, 0);
1521 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1522 	dquot_drop(inode);
1523 	if (EXT4_I(inode)->jinode) {
1524 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1525 					       EXT4_I(inode)->jinode);
1526 		jbd2_free_inode(EXT4_I(inode)->jinode);
1527 		EXT4_I(inode)->jinode = NULL;
1528 	}
1529 	fscrypt_put_encryption_info(inode);
1530 	fsverity_cleanup_inode(inode);
1531 }
1532 
1533 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1534 					u64 ino, u32 generation)
1535 {
1536 	struct inode *inode;
1537 
1538 	/*
1539 	 * Currently we don't know the generation for parent directory, so
1540 	 * a generation of 0 means "accept any"
1541 	 */
1542 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1543 	if (IS_ERR(inode))
1544 		return ERR_CAST(inode);
1545 	if (generation && inode->i_generation != generation) {
1546 		iput(inode);
1547 		return ERR_PTR(-ESTALE);
1548 	}
1549 
1550 	return inode;
1551 }
1552 
1553 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1554 					int fh_len, int fh_type)
1555 {
1556 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1557 				    ext4_nfs_get_inode);
1558 }
1559 
1560 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1561 					int fh_len, int fh_type)
1562 {
1563 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1564 				    ext4_nfs_get_inode);
1565 }
1566 
1567 static int ext4_nfs_commit_metadata(struct inode *inode)
1568 {
1569 	struct writeback_control wbc = {
1570 		.sync_mode = WB_SYNC_ALL
1571 	};
1572 
1573 	trace_ext4_nfs_commit_metadata(inode);
1574 	return ext4_write_inode(inode, &wbc);
1575 }
1576 
1577 #ifdef CONFIG_QUOTA
1578 static const char * const quotatypes[] = INITQFNAMES;
1579 #define QTYPE2NAME(t) (quotatypes[t])
1580 
1581 static int ext4_write_dquot(struct dquot *dquot);
1582 static int ext4_acquire_dquot(struct dquot *dquot);
1583 static int ext4_release_dquot(struct dquot *dquot);
1584 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1585 static int ext4_write_info(struct super_block *sb, int type);
1586 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1587 			 const struct path *path);
1588 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1589 			       size_t len, loff_t off);
1590 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1591 				const char *data, size_t len, loff_t off);
1592 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1593 			     unsigned int flags);
1594 
1595 static struct dquot **ext4_get_dquots(struct inode *inode)
1596 {
1597 	return EXT4_I(inode)->i_dquot;
1598 }
1599 
1600 static const struct dquot_operations ext4_quota_operations = {
1601 	.get_reserved_space	= ext4_get_reserved_space,
1602 	.write_dquot		= ext4_write_dquot,
1603 	.acquire_dquot		= ext4_acquire_dquot,
1604 	.release_dquot		= ext4_release_dquot,
1605 	.mark_dirty		= ext4_mark_dquot_dirty,
1606 	.write_info		= ext4_write_info,
1607 	.alloc_dquot		= dquot_alloc,
1608 	.destroy_dquot		= dquot_destroy,
1609 	.get_projid		= ext4_get_projid,
1610 	.get_inode_usage	= ext4_get_inode_usage,
1611 	.get_next_id		= dquot_get_next_id,
1612 };
1613 
1614 static const struct quotactl_ops ext4_qctl_operations = {
1615 	.quota_on	= ext4_quota_on,
1616 	.quota_off	= ext4_quota_off,
1617 	.quota_sync	= dquot_quota_sync,
1618 	.get_state	= dquot_get_state,
1619 	.set_info	= dquot_set_dqinfo,
1620 	.get_dqblk	= dquot_get_dqblk,
1621 	.set_dqblk	= dquot_set_dqblk,
1622 	.get_nextdqblk	= dquot_get_next_dqblk,
1623 };
1624 #endif
1625 
1626 static const struct super_operations ext4_sops = {
1627 	.alloc_inode	= ext4_alloc_inode,
1628 	.free_inode	= ext4_free_in_core_inode,
1629 	.destroy_inode	= ext4_destroy_inode,
1630 	.write_inode	= ext4_write_inode,
1631 	.dirty_inode	= ext4_dirty_inode,
1632 	.drop_inode	= ext4_drop_inode,
1633 	.evict_inode	= ext4_evict_inode,
1634 	.put_super	= ext4_put_super,
1635 	.sync_fs	= ext4_sync_fs,
1636 	.freeze_fs	= ext4_freeze,
1637 	.unfreeze_fs	= ext4_unfreeze,
1638 	.statfs		= ext4_statfs,
1639 	.show_options	= ext4_show_options,
1640 	.shutdown	= ext4_shutdown,
1641 #ifdef CONFIG_QUOTA
1642 	.quota_read	= ext4_quota_read,
1643 	.quota_write	= ext4_quota_write,
1644 	.get_dquots	= ext4_get_dquots,
1645 #endif
1646 };
1647 
1648 static const struct export_operations ext4_export_ops = {
1649 	.fh_to_dentry = ext4_fh_to_dentry,
1650 	.fh_to_parent = ext4_fh_to_parent,
1651 	.get_parent = ext4_get_parent,
1652 	.commit_metadata = ext4_nfs_commit_metadata,
1653 };
1654 
1655 enum {
1656 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1657 	Opt_resgid, Opt_resuid, Opt_sb,
1658 	Opt_nouid32, Opt_debug, Opt_removed,
1659 	Opt_user_xattr, Opt_acl,
1660 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1661 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1662 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1663 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1664 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1665 	Opt_inlinecrypt,
1666 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1667 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1668 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1669 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1670 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1671 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1672 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1673 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1674 	Opt_dioread_nolock, Opt_dioread_lock,
1675 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1676 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1677 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1678 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1679 #ifdef CONFIG_EXT4_DEBUG
1680 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1681 #endif
1682 };
1683 
1684 static const struct constant_table ext4_param_errors[] = {
1685 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1686 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1687 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1688 	{}
1689 };
1690 
1691 static const struct constant_table ext4_param_data[] = {
1692 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1693 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1694 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1695 	{}
1696 };
1697 
1698 static const struct constant_table ext4_param_data_err[] = {
1699 	{"abort",	Opt_data_err_abort},
1700 	{"ignore",	Opt_data_err_ignore},
1701 	{}
1702 };
1703 
1704 static const struct constant_table ext4_param_jqfmt[] = {
1705 	{"vfsold",	QFMT_VFS_OLD},
1706 	{"vfsv0",	QFMT_VFS_V0},
1707 	{"vfsv1",	QFMT_VFS_V1},
1708 	{}
1709 };
1710 
1711 static const struct constant_table ext4_param_dax[] = {
1712 	{"always",	Opt_dax_always},
1713 	{"inode",	Opt_dax_inode},
1714 	{"never",	Opt_dax_never},
1715 	{}
1716 };
1717 
1718 /* String parameter that allows empty argument */
1719 #define fsparam_string_empty(NAME, OPT) \
1720 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1721 
1722 /*
1723  * Mount option specification
1724  * We don't use fsparam_flag_no because of the way we set the
1725  * options and the way we show them in _ext4_show_options(). To
1726  * keep the changes to a minimum, let's keep the negative options
1727  * separate for now.
1728  */
1729 static const struct fs_parameter_spec ext4_param_specs[] = {
1730 	fsparam_flag	("bsddf",		Opt_bsd_df),
1731 	fsparam_flag	("minixdf",		Opt_minix_df),
1732 	fsparam_flag	("grpid",		Opt_grpid),
1733 	fsparam_flag	("bsdgroups",		Opt_grpid),
1734 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1735 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1736 	fsparam_u32	("resgid",		Opt_resgid),
1737 	fsparam_u32	("resuid",		Opt_resuid),
1738 	fsparam_u32	("sb",			Opt_sb),
1739 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1740 	fsparam_flag	("nouid32",		Opt_nouid32),
1741 	fsparam_flag	("debug",		Opt_debug),
1742 	fsparam_flag	("oldalloc",		Opt_removed),
1743 	fsparam_flag	("orlov",		Opt_removed),
1744 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1745 	fsparam_flag	("acl",			Opt_acl),
1746 	fsparam_flag	("norecovery",		Opt_noload),
1747 	fsparam_flag	("noload",		Opt_noload),
1748 	fsparam_flag	("bh",			Opt_removed),
1749 	fsparam_flag	("nobh",		Opt_removed),
1750 	fsparam_u32	("commit",		Opt_commit),
1751 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1752 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1753 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1754 	fsparam_bdev	("journal_path",	Opt_journal_path),
1755 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1756 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1757 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1758 	fsparam_flag	("abort",		Opt_abort),
1759 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1760 	fsparam_enum	("data_err",		Opt_data_err,
1761 						ext4_param_data_err),
1762 	fsparam_string_empty
1763 			("usrjquota",		Opt_usrjquota),
1764 	fsparam_string_empty
1765 			("grpjquota",		Opt_grpjquota),
1766 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1767 	fsparam_flag	("grpquota",		Opt_grpquota),
1768 	fsparam_flag	("quota",		Opt_quota),
1769 	fsparam_flag	("noquota",		Opt_noquota),
1770 	fsparam_flag	("usrquota",		Opt_usrquota),
1771 	fsparam_flag	("prjquota",		Opt_prjquota),
1772 	fsparam_flag	("barrier",		Opt_barrier),
1773 	fsparam_u32	("barrier",		Opt_barrier),
1774 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1775 	fsparam_flag	("i_version",		Opt_removed),
1776 	fsparam_flag	("dax",			Opt_dax),
1777 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1778 	fsparam_u32	("stripe",		Opt_stripe),
1779 	fsparam_flag	("delalloc",		Opt_delalloc),
1780 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1781 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1782 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1783 	fsparam_u32	("debug_want_extra_isize",
1784 						Opt_debug_want_extra_isize),
1785 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1786 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1787 	fsparam_flag	("block_validity",	Opt_block_validity),
1788 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1789 	fsparam_u32	("inode_readahead_blks",
1790 						Opt_inode_readahead_blks),
1791 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1792 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1793 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1794 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1795 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1796 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1797 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1798 	fsparam_flag	("discard",		Opt_discard),
1799 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1800 	fsparam_u32	("init_itable",		Opt_init_itable),
1801 	fsparam_flag	("init_itable",		Opt_init_itable),
1802 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1803 #ifdef CONFIG_EXT4_DEBUG
1804 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1805 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1806 #endif
1807 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1808 	fsparam_flag	("test_dummy_encryption",
1809 						Opt_test_dummy_encryption),
1810 	fsparam_string	("test_dummy_encryption",
1811 						Opt_test_dummy_encryption),
1812 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1813 	fsparam_flag	("nombcache",		Opt_nombcache),
1814 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1815 	fsparam_flag	("prefetch_block_bitmaps",
1816 						Opt_removed),
1817 	fsparam_flag	("no_prefetch_block_bitmaps",
1818 						Opt_no_prefetch_block_bitmaps),
1819 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1820 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1821 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1822 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1823 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1824 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1825 	{}
1826 };
1827 
1828 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1829 
1830 #define MOPT_SET	0x0001
1831 #define MOPT_CLEAR	0x0002
1832 #define MOPT_NOSUPPORT	0x0004
1833 #define MOPT_EXPLICIT	0x0008
1834 #ifdef CONFIG_QUOTA
1835 #define MOPT_Q		0
1836 #define MOPT_QFMT	0x0010
1837 #else
1838 #define MOPT_Q		MOPT_NOSUPPORT
1839 #define MOPT_QFMT	MOPT_NOSUPPORT
1840 #endif
1841 #define MOPT_NO_EXT2	0x0020
1842 #define MOPT_NO_EXT3	0x0040
1843 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1844 #define MOPT_SKIP	0x0080
1845 #define	MOPT_2		0x0100
1846 
1847 static const struct mount_opts {
1848 	int	token;
1849 	int	mount_opt;
1850 	int	flags;
1851 } ext4_mount_opts[] = {
1852 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1853 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1854 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1855 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1856 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1857 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1858 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1859 	 MOPT_EXT4_ONLY | MOPT_SET},
1860 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1861 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1862 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1863 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1864 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1865 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1866 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1867 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1868 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1869 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1870 	{Opt_commit, 0, MOPT_NO_EXT2},
1871 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1872 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1873 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1874 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1875 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1876 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1877 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1878 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1879 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1880 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1881 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1882 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1883 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1884 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1885 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1886 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1887 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1888 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1889 	{Opt_data, 0, MOPT_NO_EXT2},
1890 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1891 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1892 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1893 #else
1894 	{Opt_acl, 0, MOPT_NOSUPPORT},
1895 #endif
1896 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1897 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1898 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1899 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1900 							MOPT_SET | MOPT_Q},
1901 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1902 							MOPT_SET | MOPT_Q},
1903 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1904 							MOPT_SET | MOPT_Q},
1905 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1906 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1907 							MOPT_CLEAR | MOPT_Q},
1908 	{Opt_usrjquota, 0, MOPT_Q},
1909 	{Opt_grpjquota, 0, MOPT_Q},
1910 	{Opt_jqfmt, 0, MOPT_QFMT},
1911 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1912 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1913 	 MOPT_SET},
1914 #ifdef CONFIG_EXT4_DEBUG
1915 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1916 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1917 #endif
1918 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1919 	{Opt_err, 0, 0}
1920 };
1921 
1922 #if IS_ENABLED(CONFIG_UNICODE)
1923 static const struct ext4_sb_encodings {
1924 	__u16 magic;
1925 	char *name;
1926 	unsigned int version;
1927 } ext4_sb_encoding_map[] = {
1928 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1929 };
1930 
1931 static const struct ext4_sb_encodings *
1932 ext4_sb_read_encoding(const struct ext4_super_block *es)
1933 {
1934 	__u16 magic = le16_to_cpu(es->s_encoding);
1935 	int i;
1936 
1937 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1938 		if (magic == ext4_sb_encoding_map[i].magic)
1939 			return &ext4_sb_encoding_map[i];
1940 
1941 	return NULL;
1942 }
1943 #endif
1944 
1945 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1946 #define EXT4_SPEC_JQFMT				(1 <<  1)
1947 #define EXT4_SPEC_DATAJ				(1 <<  2)
1948 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1949 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1950 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1951 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1952 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1953 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1954 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1955 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1956 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1957 #define EXT4_SPEC_s_stripe			(1 << 13)
1958 #define EXT4_SPEC_s_resuid			(1 << 14)
1959 #define EXT4_SPEC_s_resgid			(1 << 15)
1960 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1961 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1962 #define EXT4_SPEC_s_sb_block			(1 << 18)
1963 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1964 
1965 struct ext4_fs_context {
1966 	char		*s_qf_names[EXT4_MAXQUOTAS];
1967 	struct fscrypt_dummy_policy dummy_enc_policy;
1968 	int		s_jquota_fmt;	/* Format of quota to use */
1969 #ifdef CONFIG_EXT4_DEBUG
1970 	int s_fc_debug_max_replay;
1971 #endif
1972 	unsigned short	qname_spec;
1973 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1974 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1975 	unsigned long	journal_devnum;
1976 	unsigned long	s_commit_interval;
1977 	unsigned long	s_stripe;
1978 	unsigned int	s_inode_readahead_blks;
1979 	unsigned int	s_want_extra_isize;
1980 	unsigned int	s_li_wait_mult;
1981 	unsigned int	s_max_dir_size_kb;
1982 	unsigned int	journal_ioprio;
1983 	unsigned int	vals_s_mount_opt;
1984 	unsigned int	mask_s_mount_opt;
1985 	unsigned int	vals_s_mount_opt2;
1986 	unsigned int	mask_s_mount_opt2;
1987 	unsigned int	opt_flags;	/* MOPT flags */
1988 	unsigned int	spec;
1989 	u32		s_max_batch_time;
1990 	u32		s_min_batch_time;
1991 	kuid_t		s_resuid;
1992 	kgid_t		s_resgid;
1993 	ext4_fsblk_t	s_sb_block;
1994 };
1995 
1996 static void ext4_fc_free(struct fs_context *fc)
1997 {
1998 	struct ext4_fs_context *ctx = fc->fs_private;
1999 	int i;
2000 
2001 	if (!ctx)
2002 		return;
2003 
2004 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2005 		kfree(ctx->s_qf_names[i]);
2006 
2007 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2008 	kfree(ctx);
2009 }
2010 
2011 int ext4_init_fs_context(struct fs_context *fc)
2012 {
2013 	struct ext4_fs_context *ctx;
2014 
2015 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2016 	if (!ctx)
2017 		return -ENOMEM;
2018 
2019 	fc->fs_private = ctx;
2020 	fc->ops = &ext4_context_ops;
2021 
2022 	return 0;
2023 }
2024 
2025 #ifdef CONFIG_QUOTA
2026 /*
2027  * Note the name of the specified quota file.
2028  */
2029 static int note_qf_name(struct fs_context *fc, int qtype,
2030 		       struct fs_parameter *param)
2031 {
2032 	struct ext4_fs_context *ctx = fc->fs_private;
2033 	char *qname;
2034 
2035 	if (param->size < 1) {
2036 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2037 		return -EINVAL;
2038 	}
2039 	if (strchr(param->string, '/')) {
2040 		ext4_msg(NULL, KERN_ERR,
2041 			 "quotafile must be on filesystem root");
2042 		return -EINVAL;
2043 	}
2044 	if (ctx->s_qf_names[qtype]) {
2045 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2046 			ext4_msg(NULL, KERN_ERR,
2047 				 "%s quota file already specified",
2048 				 QTYPE2NAME(qtype));
2049 			return -EINVAL;
2050 		}
2051 		return 0;
2052 	}
2053 
2054 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2055 	if (!qname) {
2056 		ext4_msg(NULL, KERN_ERR,
2057 			 "Not enough memory for storing quotafile name");
2058 		return -ENOMEM;
2059 	}
2060 	ctx->s_qf_names[qtype] = qname;
2061 	ctx->qname_spec |= 1 << qtype;
2062 	ctx->spec |= EXT4_SPEC_JQUOTA;
2063 	return 0;
2064 }
2065 
2066 /*
2067  * Clear the name of the specified quota file.
2068  */
2069 static int unnote_qf_name(struct fs_context *fc, int qtype)
2070 {
2071 	struct ext4_fs_context *ctx = fc->fs_private;
2072 
2073 	if (ctx->s_qf_names[qtype])
2074 		kfree(ctx->s_qf_names[qtype]);
2075 
2076 	ctx->s_qf_names[qtype] = NULL;
2077 	ctx->qname_spec |= 1 << qtype;
2078 	ctx->spec |= EXT4_SPEC_JQUOTA;
2079 	return 0;
2080 }
2081 #endif
2082 
2083 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2084 					    struct ext4_fs_context *ctx)
2085 {
2086 	int err;
2087 
2088 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2089 		ext4_msg(NULL, KERN_WARNING,
2090 			 "test_dummy_encryption option not supported");
2091 		return -EINVAL;
2092 	}
2093 	err = fscrypt_parse_test_dummy_encryption(param,
2094 						  &ctx->dummy_enc_policy);
2095 	if (err == -EINVAL) {
2096 		ext4_msg(NULL, KERN_WARNING,
2097 			 "Value of option \"%s\" is unrecognized", param->key);
2098 	} else if (err == -EEXIST) {
2099 		ext4_msg(NULL, KERN_WARNING,
2100 			 "Conflicting test_dummy_encryption options");
2101 		return -EINVAL;
2102 	}
2103 	return err;
2104 }
2105 
2106 #define EXT4_SET_CTX(name)						\
2107 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2108 				  unsigned long flag)			\
2109 {									\
2110 	ctx->mask_s_##name |= flag;					\
2111 	ctx->vals_s_##name |= flag;					\
2112 }
2113 
2114 #define EXT4_CLEAR_CTX(name)						\
2115 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2116 				    unsigned long flag)			\
2117 {									\
2118 	ctx->mask_s_##name |= flag;					\
2119 	ctx->vals_s_##name &= ~flag;					\
2120 }
2121 
2122 #define EXT4_TEST_CTX(name)						\
2123 static inline unsigned long						\
2124 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2125 {									\
2126 	return (ctx->vals_s_##name & flag);				\
2127 }
2128 
2129 EXT4_SET_CTX(flags); /* set only */
2130 EXT4_SET_CTX(mount_opt);
2131 EXT4_CLEAR_CTX(mount_opt);
2132 EXT4_TEST_CTX(mount_opt);
2133 EXT4_SET_CTX(mount_opt2);
2134 EXT4_CLEAR_CTX(mount_opt2);
2135 EXT4_TEST_CTX(mount_opt2);
2136 
2137 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2138 {
2139 	struct ext4_fs_context *ctx = fc->fs_private;
2140 	struct fs_parse_result result;
2141 	const struct mount_opts *m;
2142 	int is_remount;
2143 	kuid_t uid;
2144 	kgid_t gid;
2145 	int token;
2146 
2147 	token = fs_parse(fc, ext4_param_specs, param, &result);
2148 	if (token < 0)
2149 		return token;
2150 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2151 
2152 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2153 		if (token == m->token)
2154 			break;
2155 
2156 	ctx->opt_flags |= m->flags;
2157 
2158 	if (m->flags & MOPT_EXPLICIT) {
2159 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2160 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2161 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2162 			ctx_set_mount_opt2(ctx,
2163 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2164 		} else
2165 			return -EINVAL;
2166 	}
2167 
2168 	if (m->flags & MOPT_NOSUPPORT) {
2169 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2170 			 param->key);
2171 		return 0;
2172 	}
2173 
2174 	switch (token) {
2175 #ifdef CONFIG_QUOTA
2176 	case Opt_usrjquota:
2177 		if (!*param->string)
2178 			return unnote_qf_name(fc, USRQUOTA);
2179 		else
2180 			return note_qf_name(fc, USRQUOTA, param);
2181 	case Opt_grpjquota:
2182 		if (!*param->string)
2183 			return unnote_qf_name(fc, GRPQUOTA);
2184 		else
2185 			return note_qf_name(fc, GRPQUOTA, param);
2186 #endif
2187 	case Opt_sb:
2188 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2189 			ext4_msg(NULL, KERN_WARNING,
2190 				 "Ignoring %s option on remount", param->key);
2191 		} else {
2192 			ctx->s_sb_block = result.uint_32;
2193 			ctx->spec |= EXT4_SPEC_s_sb_block;
2194 		}
2195 		return 0;
2196 	case Opt_removed:
2197 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2198 			 param->key);
2199 		return 0;
2200 	case Opt_inlinecrypt:
2201 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2202 		ctx_set_flags(ctx, SB_INLINECRYPT);
2203 #else
2204 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2205 #endif
2206 		return 0;
2207 	case Opt_errors:
2208 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2209 		ctx_set_mount_opt(ctx, result.uint_32);
2210 		return 0;
2211 #ifdef CONFIG_QUOTA
2212 	case Opt_jqfmt:
2213 		ctx->s_jquota_fmt = result.uint_32;
2214 		ctx->spec |= EXT4_SPEC_JQFMT;
2215 		return 0;
2216 #endif
2217 	case Opt_data:
2218 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2219 		ctx_set_mount_opt(ctx, result.uint_32);
2220 		ctx->spec |= EXT4_SPEC_DATAJ;
2221 		return 0;
2222 	case Opt_commit:
2223 		if (result.uint_32 == 0)
2224 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2225 		else if (result.uint_32 > INT_MAX / HZ) {
2226 			ext4_msg(NULL, KERN_ERR,
2227 				 "Invalid commit interval %d, "
2228 				 "must be smaller than %d",
2229 				 result.uint_32, INT_MAX / HZ);
2230 			return -EINVAL;
2231 		}
2232 		ctx->s_commit_interval = HZ * result.uint_32;
2233 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2234 		return 0;
2235 	case Opt_debug_want_extra_isize:
2236 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2237 			ext4_msg(NULL, KERN_ERR,
2238 				 "Invalid want_extra_isize %d", result.uint_32);
2239 			return -EINVAL;
2240 		}
2241 		ctx->s_want_extra_isize = result.uint_32;
2242 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2243 		return 0;
2244 	case Opt_max_batch_time:
2245 		ctx->s_max_batch_time = result.uint_32;
2246 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2247 		return 0;
2248 	case Opt_min_batch_time:
2249 		ctx->s_min_batch_time = result.uint_32;
2250 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2251 		return 0;
2252 	case Opt_inode_readahead_blks:
2253 		if (result.uint_32 &&
2254 		    (result.uint_32 > (1 << 30) ||
2255 		     !is_power_of_2(result.uint_32))) {
2256 			ext4_msg(NULL, KERN_ERR,
2257 				 "EXT4-fs: inode_readahead_blks must be "
2258 				 "0 or a power of 2 smaller than 2^31");
2259 			return -EINVAL;
2260 		}
2261 		ctx->s_inode_readahead_blks = result.uint_32;
2262 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2263 		return 0;
2264 	case Opt_init_itable:
2265 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2266 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2267 		if (param->type == fs_value_is_string)
2268 			ctx->s_li_wait_mult = result.uint_32;
2269 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2270 		return 0;
2271 	case Opt_max_dir_size_kb:
2272 		ctx->s_max_dir_size_kb = result.uint_32;
2273 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2274 		return 0;
2275 #ifdef CONFIG_EXT4_DEBUG
2276 	case Opt_fc_debug_max_replay:
2277 		ctx->s_fc_debug_max_replay = result.uint_32;
2278 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2279 		return 0;
2280 #endif
2281 	case Opt_stripe:
2282 		ctx->s_stripe = result.uint_32;
2283 		ctx->spec |= EXT4_SPEC_s_stripe;
2284 		return 0;
2285 	case Opt_resuid:
2286 		uid = make_kuid(current_user_ns(), result.uint_32);
2287 		if (!uid_valid(uid)) {
2288 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2289 				 result.uint_32);
2290 			return -EINVAL;
2291 		}
2292 		ctx->s_resuid = uid;
2293 		ctx->spec |= EXT4_SPEC_s_resuid;
2294 		return 0;
2295 	case Opt_resgid:
2296 		gid = make_kgid(current_user_ns(), result.uint_32);
2297 		if (!gid_valid(gid)) {
2298 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2299 				 result.uint_32);
2300 			return -EINVAL;
2301 		}
2302 		ctx->s_resgid = gid;
2303 		ctx->spec |= EXT4_SPEC_s_resgid;
2304 		return 0;
2305 	case Opt_journal_dev:
2306 		if (is_remount) {
2307 			ext4_msg(NULL, KERN_ERR,
2308 				 "Cannot specify journal on remount");
2309 			return -EINVAL;
2310 		}
2311 		ctx->journal_devnum = result.uint_32;
2312 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2313 		return 0;
2314 	case Opt_journal_path:
2315 	{
2316 		struct inode *journal_inode;
2317 		struct path path;
2318 		int error;
2319 
2320 		if (is_remount) {
2321 			ext4_msg(NULL, KERN_ERR,
2322 				 "Cannot specify journal on remount");
2323 			return -EINVAL;
2324 		}
2325 
2326 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2327 		if (error) {
2328 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2329 				 "journal device path");
2330 			return -EINVAL;
2331 		}
2332 
2333 		journal_inode = d_inode(path.dentry);
2334 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2335 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2336 		path_put(&path);
2337 		return 0;
2338 	}
2339 	case Opt_journal_ioprio:
2340 		if (result.uint_32 > 7) {
2341 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2342 				 " (must be 0-7)");
2343 			return -EINVAL;
2344 		}
2345 		ctx->journal_ioprio =
2346 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2347 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2348 		return 0;
2349 	case Opt_test_dummy_encryption:
2350 		return ext4_parse_test_dummy_encryption(param, ctx);
2351 	case Opt_dax:
2352 	case Opt_dax_type:
2353 #ifdef CONFIG_FS_DAX
2354 	{
2355 		int type = (token == Opt_dax) ?
2356 			   Opt_dax : result.uint_32;
2357 
2358 		switch (type) {
2359 		case Opt_dax:
2360 		case Opt_dax_always:
2361 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2362 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2363 			break;
2364 		case Opt_dax_never:
2365 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2366 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2367 			break;
2368 		case Opt_dax_inode:
2369 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2370 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2371 			/* Strictly for printing options */
2372 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2373 			break;
2374 		}
2375 		return 0;
2376 	}
2377 #else
2378 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2379 		return -EINVAL;
2380 #endif
2381 	case Opt_data_err:
2382 		if (result.uint_32 == Opt_data_err_abort)
2383 			ctx_set_mount_opt(ctx, m->mount_opt);
2384 		else if (result.uint_32 == Opt_data_err_ignore)
2385 			ctx_clear_mount_opt(ctx, m->mount_opt);
2386 		return 0;
2387 	case Opt_mb_optimize_scan:
2388 		if (result.int_32 == 1) {
2389 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2390 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2391 		} else if (result.int_32 == 0) {
2392 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2393 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2394 		} else {
2395 			ext4_msg(NULL, KERN_WARNING,
2396 				 "mb_optimize_scan should be set to 0 or 1.");
2397 			return -EINVAL;
2398 		}
2399 		return 0;
2400 	}
2401 
2402 	/*
2403 	 * At this point we should only be getting options requiring MOPT_SET,
2404 	 * or MOPT_CLEAR. Anything else is a bug
2405 	 */
2406 	if (m->token == Opt_err) {
2407 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2408 			 param->key);
2409 		WARN_ON(1);
2410 		return -EINVAL;
2411 	}
2412 
2413 	else {
2414 		unsigned int set = 0;
2415 
2416 		if ((param->type == fs_value_is_flag) ||
2417 		    result.uint_32 > 0)
2418 			set = 1;
2419 
2420 		if (m->flags & MOPT_CLEAR)
2421 			set = !set;
2422 		else if (unlikely(!(m->flags & MOPT_SET))) {
2423 			ext4_msg(NULL, KERN_WARNING,
2424 				 "buggy handling of option %s",
2425 				 param->key);
2426 			WARN_ON(1);
2427 			return -EINVAL;
2428 		}
2429 		if (m->flags & MOPT_2) {
2430 			if (set != 0)
2431 				ctx_set_mount_opt2(ctx, m->mount_opt);
2432 			else
2433 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2434 		} else {
2435 			if (set != 0)
2436 				ctx_set_mount_opt(ctx, m->mount_opt);
2437 			else
2438 				ctx_clear_mount_opt(ctx, m->mount_opt);
2439 		}
2440 	}
2441 
2442 	return 0;
2443 }
2444 
2445 static int parse_options(struct fs_context *fc, char *options)
2446 {
2447 	struct fs_parameter param;
2448 	int ret;
2449 	char *key;
2450 
2451 	if (!options)
2452 		return 0;
2453 
2454 	while ((key = strsep(&options, ",")) != NULL) {
2455 		if (*key) {
2456 			size_t v_len = 0;
2457 			char *value = strchr(key, '=');
2458 
2459 			param.type = fs_value_is_flag;
2460 			param.string = NULL;
2461 
2462 			if (value) {
2463 				if (value == key)
2464 					continue;
2465 
2466 				*value++ = 0;
2467 				v_len = strlen(value);
2468 				param.string = kmemdup_nul(value, v_len,
2469 							   GFP_KERNEL);
2470 				if (!param.string)
2471 					return -ENOMEM;
2472 				param.type = fs_value_is_string;
2473 			}
2474 
2475 			param.key = key;
2476 			param.size = v_len;
2477 
2478 			ret = ext4_parse_param(fc, &param);
2479 			if (param.string)
2480 				kfree(param.string);
2481 			if (ret < 0)
2482 				return ret;
2483 		}
2484 	}
2485 
2486 	ret = ext4_validate_options(fc);
2487 	if (ret < 0)
2488 		return ret;
2489 
2490 	return 0;
2491 }
2492 
2493 static int parse_apply_sb_mount_options(struct super_block *sb,
2494 					struct ext4_fs_context *m_ctx)
2495 {
2496 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2497 	char *s_mount_opts = NULL;
2498 	struct ext4_fs_context *s_ctx = NULL;
2499 	struct fs_context *fc = NULL;
2500 	int ret = -ENOMEM;
2501 
2502 	if (!sbi->s_es->s_mount_opts[0])
2503 		return 0;
2504 
2505 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2506 				sizeof(sbi->s_es->s_mount_opts),
2507 				GFP_KERNEL);
2508 	if (!s_mount_opts)
2509 		return ret;
2510 
2511 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2512 	if (!fc)
2513 		goto out_free;
2514 
2515 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2516 	if (!s_ctx)
2517 		goto out_free;
2518 
2519 	fc->fs_private = s_ctx;
2520 	fc->s_fs_info = sbi;
2521 
2522 	ret = parse_options(fc, s_mount_opts);
2523 	if (ret < 0)
2524 		goto parse_failed;
2525 
2526 	ret = ext4_check_opt_consistency(fc, sb);
2527 	if (ret < 0) {
2528 parse_failed:
2529 		ext4_msg(sb, KERN_WARNING,
2530 			 "failed to parse options in superblock: %s",
2531 			 s_mount_opts);
2532 		ret = 0;
2533 		goto out_free;
2534 	}
2535 
2536 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2537 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2538 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2539 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2540 
2541 	ext4_apply_options(fc, sb);
2542 	ret = 0;
2543 
2544 out_free:
2545 	if (fc) {
2546 		ext4_fc_free(fc);
2547 		kfree(fc);
2548 	}
2549 	kfree(s_mount_opts);
2550 	return ret;
2551 }
2552 
2553 static void ext4_apply_quota_options(struct fs_context *fc,
2554 				     struct super_block *sb)
2555 {
2556 #ifdef CONFIG_QUOTA
2557 	bool quota_feature = ext4_has_feature_quota(sb);
2558 	struct ext4_fs_context *ctx = fc->fs_private;
2559 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2560 	char *qname;
2561 	int i;
2562 
2563 	if (quota_feature)
2564 		return;
2565 
2566 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2567 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2568 			if (!(ctx->qname_spec & (1 << i)))
2569 				continue;
2570 
2571 			qname = ctx->s_qf_names[i]; /* May be NULL */
2572 			if (qname)
2573 				set_opt(sb, QUOTA);
2574 			ctx->s_qf_names[i] = NULL;
2575 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2576 						lockdep_is_held(&sb->s_umount));
2577 			if (qname)
2578 				kfree_rcu_mightsleep(qname);
2579 		}
2580 	}
2581 
2582 	if (ctx->spec & EXT4_SPEC_JQFMT)
2583 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2584 #endif
2585 }
2586 
2587 /*
2588  * Check quota settings consistency.
2589  */
2590 static int ext4_check_quota_consistency(struct fs_context *fc,
2591 					struct super_block *sb)
2592 {
2593 #ifdef CONFIG_QUOTA
2594 	struct ext4_fs_context *ctx = fc->fs_private;
2595 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2596 	bool quota_feature = ext4_has_feature_quota(sb);
2597 	bool quota_loaded = sb_any_quota_loaded(sb);
2598 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2599 	int quota_flags, i;
2600 
2601 	/*
2602 	 * We do the test below only for project quotas. 'usrquota' and
2603 	 * 'grpquota' mount options are allowed even without quota feature
2604 	 * to support legacy quotas in quota files.
2605 	 */
2606 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2607 	    !ext4_has_feature_project(sb)) {
2608 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2609 			 "Cannot enable project quota enforcement.");
2610 		return -EINVAL;
2611 	}
2612 
2613 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2614 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2615 	if (quota_loaded &&
2616 	    ctx->mask_s_mount_opt & quota_flags &&
2617 	    !ctx_test_mount_opt(ctx, quota_flags))
2618 		goto err_quota_change;
2619 
2620 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2621 
2622 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2623 			if (!(ctx->qname_spec & (1 << i)))
2624 				continue;
2625 
2626 			if (quota_loaded &&
2627 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2628 				goto err_jquota_change;
2629 
2630 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2631 			    strcmp(get_qf_name(sb, sbi, i),
2632 				   ctx->s_qf_names[i]) != 0)
2633 				goto err_jquota_specified;
2634 		}
2635 
2636 		if (quota_feature) {
2637 			ext4_msg(NULL, KERN_INFO,
2638 				 "Journaled quota options ignored when "
2639 				 "QUOTA feature is enabled");
2640 			return 0;
2641 		}
2642 	}
2643 
2644 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2645 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2646 			goto err_jquota_change;
2647 		if (quota_feature) {
2648 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2649 				 "ignored when QUOTA feature is enabled");
2650 			return 0;
2651 		}
2652 	}
2653 
2654 	/* Make sure we don't mix old and new quota format */
2655 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2656 		       ctx->s_qf_names[USRQUOTA]);
2657 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2658 		       ctx->s_qf_names[GRPQUOTA]);
2659 
2660 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2661 		    test_opt(sb, USRQUOTA));
2662 
2663 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2664 		    test_opt(sb, GRPQUOTA));
2665 
2666 	if (usr_qf_name) {
2667 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2668 		usrquota = false;
2669 	}
2670 	if (grp_qf_name) {
2671 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2672 		grpquota = false;
2673 	}
2674 
2675 	if (usr_qf_name || grp_qf_name) {
2676 		if (usrquota || grpquota) {
2677 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2678 				 "format mixing");
2679 			return -EINVAL;
2680 		}
2681 
2682 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2683 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2684 				 "not specified");
2685 			return -EINVAL;
2686 		}
2687 	}
2688 
2689 	return 0;
2690 
2691 err_quota_change:
2692 	ext4_msg(NULL, KERN_ERR,
2693 		 "Cannot change quota options when quota turned on");
2694 	return -EINVAL;
2695 err_jquota_change:
2696 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2697 		 "options when quota turned on");
2698 	return -EINVAL;
2699 err_jquota_specified:
2700 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2701 		 QTYPE2NAME(i));
2702 	return -EINVAL;
2703 #else
2704 	return 0;
2705 #endif
2706 }
2707 
2708 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2709 					    struct super_block *sb)
2710 {
2711 	const struct ext4_fs_context *ctx = fc->fs_private;
2712 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2713 
2714 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2715 		return 0;
2716 
2717 	if (!ext4_has_feature_encrypt(sb)) {
2718 		ext4_msg(NULL, KERN_WARNING,
2719 			 "test_dummy_encryption requires encrypt feature");
2720 		return -EINVAL;
2721 	}
2722 	/*
2723 	 * This mount option is just for testing, and it's not worthwhile to
2724 	 * implement the extra complexity (e.g. RCU protection) that would be
2725 	 * needed to allow it to be set or changed during remount.  We do allow
2726 	 * it to be specified during remount, but only if there is no change.
2727 	 */
2728 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2729 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2730 						 &ctx->dummy_enc_policy))
2731 			return 0;
2732 		ext4_msg(NULL, KERN_WARNING,
2733 			 "Can't set or change test_dummy_encryption on remount");
2734 		return -EINVAL;
2735 	}
2736 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2737 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2738 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2739 						 &ctx->dummy_enc_policy))
2740 			return 0;
2741 		ext4_msg(NULL, KERN_WARNING,
2742 			 "Conflicting test_dummy_encryption options");
2743 		return -EINVAL;
2744 	}
2745 	return 0;
2746 }
2747 
2748 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2749 					     struct super_block *sb)
2750 {
2751 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2752 	    /* if already set, it was already verified to be the same */
2753 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2754 		return;
2755 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2756 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2757 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2758 }
2759 
2760 static int ext4_check_opt_consistency(struct fs_context *fc,
2761 				      struct super_block *sb)
2762 {
2763 	struct ext4_fs_context *ctx = fc->fs_private;
2764 	struct ext4_sb_info *sbi = fc->s_fs_info;
2765 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2766 	int err;
2767 
2768 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2769 		ext4_msg(NULL, KERN_ERR,
2770 			 "Mount option(s) incompatible with ext2");
2771 		return -EINVAL;
2772 	}
2773 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2774 		ext4_msg(NULL, KERN_ERR,
2775 			 "Mount option(s) incompatible with ext3");
2776 		return -EINVAL;
2777 	}
2778 
2779 	if (ctx->s_want_extra_isize >
2780 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2781 		ext4_msg(NULL, KERN_ERR,
2782 			 "Invalid want_extra_isize %d",
2783 			 ctx->s_want_extra_isize);
2784 		return -EINVAL;
2785 	}
2786 
2787 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2788 		int blocksize =
2789 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2790 		if (blocksize < PAGE_SIZE)
2791 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2792 				 "experimental mount option 'dioread_nolock' "
2793 				 "for blocksize < PAGE_SIZE");
2794 	}
2795 
2796 	err = ext4_check_test_dummy_encryption(fc, sb);
2797 	if (err)
2798 		return err;
2799 
2800 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2801 		if (!sbi->s_journal) {
2802 			ext4_msg(NULL, KERN_WARNING,
2803 				 "Remounting file system with no journal "
2804 				 "so ignoring journalled data option");
2805 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2806 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2807 			   test_opt(sb, DATA_FLAGS)) {
2808 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2809 				 "on remount");
2810 			return -EINVAL;
2811 		}
2812 	}
2813 
2814 	if (is_remount) {
2815 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2816 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2817 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2818 				 "both data=journal and dax");
2819 			return -EINVAL;
2820 		}
2821 
2822 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2823 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2824 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2825 fail_dax_change_remount:
2826 			ext4_msg(NULL, KERN_ERR, "can't change "
2827 				 "dax mount option while remounting");
2828 			return -EINVAL;
2829 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2830 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2831 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2832 			goto fail_dax_change_remount;
2833 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2834 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2835 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2836 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2837 			goto fail_dax_change_remount;
2838 		}
2839 	}
2840 
2841 	return ext4_check_quota_consistency(fc, sb);
2842 }
2843 
2844 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2845 {
2846 	struct ext4_fs_context *ctx = fc->fs_private;
2847 	struct ext4_sb_info *sbi = fc->s_fs_info;
2848 
2849 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2850 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2851 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2852 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2853 	sb->s_flags &= ~ctx->mask_s_flags;
2854 	sb->s_flags |= ctx->vals_s_flags;
2855 
2856 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2857 	APPLY(s_commit_interval);
2858 	APPLY(s_stripe);
2859 	APPLY(s_max_batch_time);
2860 	APPLY(s_min_batch_time);
2861 	APPLY(s_want_extra_isize);
2862 	APPLY(s_inode_readahead_blks);
2863 	APPLY(s_max_dir_size_kb);
2864 	APPLY(s_li_wait_mult);
2865 	APPLY(s_resgid);
2866 	APPLY(s_resuid);
2867 
2868 #ifdef CONFIG_EXT4_DEBUG
2869 	APPLY(s_fc_debug_max_replay);
2870 #endif
2871 
2872 	ext4_apply_quota_options(fc, sb);
2873 	ext4_apply_test_dummy_encryption(ctx, sb);
2874 }
2875 
2876 
2877 static int ext4_validate_options(struct fs_context *fc)
2878 {
2879 #ifdef CONFIG_QUOTA
2880 	struct ext4_fs_context *ctx = fc->fs_private;
2881 	char *usr_qf_name, *grp_qf_name;
2882 
2883 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2884 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2885 
2886 	if (usr_qf_name || grp_qf_name) {
2887 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2888 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2889 
2890 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2891 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2892 
2893 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2894 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2895 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2896 				 "format mixing");
2897 			return -EINVAL;
2898 		}
2899 	}
2900 #endif
2901 	return 1;
2902 }
2903 
2904 static inline void ext4_show_quota_options(struct seq_file *seq,
2905 					   struct super_block *sb)
2906 {
2907 #if defined(CONFIG_QUOTA)
2908 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2909 	char *usr_qf_name, *grp_qf_name;
2910 
2911 	if (sbi->s_jquota_fmt) {
2912 		char *fmtname = "";
2913 
2914 		switch (sbi->s_jquota_fmt) {
2915 		case QFMT_VFS_OLD:
2916 			fmtname = "vfsold";
2917 			break;
2918 		case QFMT_VFS_V0:
2919 			fmtname = "vfsv0";
2920 			break;
2921 		case QFMT_VFS_V1:
2922 			fmtname = "vfsv1";
2923 			break;
2924 		}
2925 		seq_printf(seq, ",jqfmt=%s", fmtname);
2926 	}
2927 
2928 	rcu_read_lock();
2929 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2930 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2931 	if (usr_qf_name)
2932 		seq_show_option(seq, "usrjquota", usr_qf_name);
2933 	if (grp_qf_name)
2934 		seq_show_option(seq, "grpjquota", grp_qf_name);
2935 	rcu_read_unlock();
2936 #endif
2937 }
2938 
2939 static const char *token2str(int token)
2940 {
2941 	const struct fs_parameter_spec *spec;
2942 
2943 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2944 		if (spec->opt == token && !spec->type)
2945 			break;
2946 	return spec->name;
2947 }
2948 
2949 /*
2950  * Show an option if
2951  *  - it's set to a non-default value OR
2952  *  - if the per-sb default is different from the global default
2953  */
2954 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2955 			      int nodefs)
2956 {
2957 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2958 	struct ext4_super_block *es = sbi->s_es;
2959 	int def_errors;
2960 	const struct mount_opts *m;
2961 	char sep = nodefs ? '\n' : ',';
2962 
2963 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2964 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2965 
2966 	if (sbi->s_sb_block != 1)
2967 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2968 
2969 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2970 		int want_set = m->flags & MOPT_SET;
2971 		int opt_2 = m->flags & MOPT_2;
2972 		unsigned int mount_opt, def_mount_opt;
2973 
2974 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2975 		    m->flags & MOPT_SKIP)
2976 			continue;
2977 
2978 		if (opt_2) {
2979 			mount_opt = sbi->s_mount_opt2;
2980 			def_mount_opt = sbi->s_def_mount_opt2;
2981 		} else {
2982 			mount_opt = sbi->s_mount_opt;
2983 			def_mount_opt = sbi->s_def_mount_opt;
2984 		}
2985 		/* skip if same as the default */
2986 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2987 			continue;
2988 		/* select Opt_noFoo vs Opt_Foo */
2989 		if ((want_set &&
2990 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
2991 		    (!want_set && (mount_opt & m->mount_opt)))
2992 			continue;
2993 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2994 	}
2995 
2996 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2997 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2998 		SEQ_OPTS_PRINT("resuid=%u",
2999 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
3000 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
3001 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
3002 		SEQ_OPTS_PRINT("resgid=%u",
3003 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
3004 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
3005 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3006 		SEQ_OPTS_PUTS("errors=remount-ro");
3007 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3008 		SEQ_OPTS_PUTS("errors=continue");
3009 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3010 		SEQ_OPTS_PUTS("errors=panic");
3011 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3012 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3013 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3014 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3015 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3016 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3017 	if (nodefs || sbi->s_stripe)
3018 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3019 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3020 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3021 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3022 			SEQ_OPTS_PUTS("data=journal");
3023 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3024 			SEQ_OPTS_PUTS("data=ordered");
3025 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3026 			SEQ_OPTS_PUTS("data=writeback");
3027 	}
3028 	if (nodefs ||
3029 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3030 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3031 			       sbi->s_inode_readahead_blks);
3032 
3033 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3034 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3035 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3036 	if (nodefs || sbi->s_max_dir_size_kb)
3037 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3038 	if (test_opt(sb, DATA_ERR_ABORT))
3039 		SEQ_OPTS_PUTS("data_err=abort");
3040 
3041 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3042 
3043 	if (sb->s_flags & SB_INLINECRYPT)
3044 		SEQ_OPTS_PUTS("inlinecrypt");
3045 
3046 	if (test_opt(sb, DAX_ALWAYS)) {
3047 		if (IS_EXT2_SB(sb))
3048 			SEQ_OPTS_PUTS("dax");
3049 		else
3050 			SEQ_OPTS_PUTS("dax=always");
3051 	} else if (test_opt2(sb, DAX_NEVER)) {
3052 		SEQ_OPTS_PUTS("dax=never");
3053 	} else if (test_opt2(sb, DAX_INODE)) {
3054 		SEQ_OPTS_PUTS("dax=inode");
3055 	}
3056 
3057 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3058 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3059 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3060 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3061 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3062 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3063 	}
3064 
3065 	ext4_show_quota_options(seq, sb);
3066 	return 0;
3067 }
3068 
3069 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3070 {
3071 	return _ext4_show_options(seq, root->d_sb, 0);
3072 }
3073 
3074 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3075 {
3076 	struct super_block *sb = seq->private;
3077 	int rc;
3078 
3079 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3080 	rc = _ext4_show_options(seq, sb, 1);
3081 	seq_puts(seq, "\n");
3082 	return rc;
3083 }
3084 
3085 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3086 			    int read_only)
3087 {
3088 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3089 	int err = 0;
3090 
3091 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3092 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3093 			 "forcing read-only mode");
3094 		err = -EROFS;
3095 		goto done;
3096 	}
3097 	if (read_only)
3098 		goto done;
3099 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3100 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3101 			 "running e2fsck is recommended");
3102 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3103 		ext4_msg(sb, KERN_WARNING,
3104 			 "warning: mounting fs with errors, "
3105 			 "running e2fsck is recommended");
3106 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3107 		 le16_to_cpu(es->s_mnt_count) >=
3108 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3109 		ext4_msg(sb, KERN_WARNING,
3110 			 "warning: maximal mount count reached, "
3111 			 "running e2fsck is recommended");
3112 	else if (le32_to_cpu(es->s_checkinterval) &&
3113 		 (ext4_get_tstamp(es, s_lastcheck) +
3114 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3115 		ext4_msg(sb, KERN_WARNING,
3116 			 "warning: checktime reached, "
3117 			 "running e2fsck is recommended");
3118 	if (!sbi->s_journal)
3119 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3120 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3121 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3122 	le16_add_cpu(&es->s_mnt_count, 1);
3123 	ext4_update_tstamp(es, s_mtime);
3124 	if (sbi->s_journal) {
3125 		ext4_set_feature_journal_needs_recovery(sb);
3126 		if (ext4_has_feature_orphan_file(sb))
3127 			ext4_set_feature_orphan_present(sb);
3128 	}
3129 
3130 	err = ext4_commit_super(sb);
3131 done:
3132 	if (test_opt(sb, DEBUG))
3133 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3134 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3135 			sb->s_blocksize,
3136 			sbi->s_groups_count,
3137 			EXT4_BLOCKS_PER_GROUP(sb),
3138 			EXT4_INODES_PER_GROUP(sb),
3139 			sbi->s_mount_opt, sbi->s_mount_opt2);
3140 	return err;
3141 }
3142 
3143 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3144 {
3145 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3146 	struct flex_groups **old_groups, **new_groups;
3147 	int size, i, j;
3148 
3149 	if (!sbi->s_log_groups_per_flex)
3150 		return 0;
3151 
3152 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3153 	if (size <= sbi->s_flex_groups_allocated)
3154 		return 0;
3155 
3156 	new_groups = kvzalloc(roundup_pow_of_two(size *
3157 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3158 	if (!new_groups) {
3159 		ext4_msg(sb, KERN_ERR,
3160 			 "not enough memory for %d flex group pointers", size);
3161 		return -ENOMEM;
3162 	}
3163 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3164 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3165 					 sizeof(struct flex_groups)),
3166 					 GFP_KERNEL);
3167 		if (!new_groups[i]) {
3168 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3169 				kvfree(new_groups[j]);
3170 			kvfree(new_groups);
3171 			ext4_msg(sb, KERN_ERR,
3172 				 "not enough memory for %d flex groups", size);
3173 			return -ENOMEM;
3174 		}
3175 	}
3176 	rcu_read_lock();
3177 	old_groups = rcu_dereference(sbi->s_flex_groups);
3178 	if (old_groups)
3179 		memcpy(new_groups, old_groups,
3180 		       (sbi->s_flex_groups_allocated *
3181 			sizeof(struct flex_groups *)));
3182 	rcu_read_unlock();
3183 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3184 	sbi->s_flex_groups_allocated = size;
3185 	if (old_groups)
3186 		ext4_kvfree_array_rcu(old_groups);
3187 	return 0;
3188 }
3189 
3190 static int ext4_fill_flex_info(struct super_block *sb)
3191 {
3192 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3193 	struct ext4_group_desc *gdp = NULL;
3194 	struct flex_groups *fg;
3195 	ext4_group_t flex_group;
3196 	int i, err;
3197 
3198 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3199 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3200 		sbi->s_log_groups_per_flex = 0;
3201 		return 1;
3202 	}
3203 
3204 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3205 	if (err)
3206 		goto failed;
3207 
3208 	for (i = 0; i < sbi->s_groups_count; i++) {
3209 		gdp = ext4_get_group_desc(sb, i, NULL);
3210 
3211 		flex_group = ext4_flex_group(sbi, i);
3212 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3213 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3214 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3215 			     &fg->free_clusters);
3216 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3217 	}
3218 
3219 	return 1;
3220 failed:
3221 	return 0;
3222 }
3223 
3224 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3225 				   struct ext4_group_desc *gdp)
3226 {
3227 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3228 	__u16 crc = 0;
3229 	__le32 le_group = cpu_to_le32(block_group);
3230 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3231 
3232 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3233 		/* Use new metadata_csum algorithm */
3234 		__u32 csum32;
3235 		__u16 dummy_csum = 0;
3236 
3237 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3238 				     sizeof(le_group));
3239 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3240 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3241 				     sizeof(dummy_csum));
3242 		offset += sizeof(dummy_csum);
3243 		if (offset < sbi->s_desc_size)
3244 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3245 					     sbi->s_desc_size - offset);
3246 
3247 		crc = csum32 & 0xFFFF;
3248 		goto out;
3249 	}
3250 
3251 	/* old crc16 code */
3252 	if (!ext4_has_feature_gdt_csum(sb))
3253 		return 0;
3254 
3255 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3256 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3257 	crc = crc16(crc, (__u8 *)gdp, offset);
3258 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3259 	/* for checksum of struct ext4_group_desc do the rest...*/
3260 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3261 		crc = crc16(crc, (__u8 *)gdp + offset,
3262 			    sbi->s_desc_size - offset);
3263 
3264 out:
3265 	return cpu_to_le16(crc);
3266 }
3267 
3268 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3269 				struct ext4_group_desc *gdp)
3270 {
3271 	if (ext4_has_group_desc_csum(sb) &&
3272 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3273 		return 0;
3274 
3275 	return 1;
3276 }
3277 
3278 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3279 			      struct ext4_group_desc *gdp)
3280 {
3281 	if (!ext4_has_group_desc_csum(sb))
3282 		return;
3283 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3284 }
3285 
3286 /* Called at mount-time, super-block is locked */
3287 static int ext4_check_descriptors(struct super_block *sb,
3288 				  ext4_fsblk_t sb_block,
3289 				  ext4_group_t *first_not_zeroed)
3290 {
3291 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3292 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3293 	ext4_fsblk_t last_block;
3294 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3295 	ext4_fsblk_t block_bitmap;
3296 	ext4_fsblk_t inode_bitmap;
3297 	ext4_fsblk_t inode_table;
3298 	int flexbg_flag = 0;
3299 	ext4_group_t i, grp = sbi->s_groups_count;
3300 
3301 	if (ext4_has_feature_flex_bg(sb))
3302 		flexbg_flag = 1;
3303 
3304 	ext4_debug("Checking group descriptors");
3305 
3306 	for (i = 0; i < sbi->s_groups_count; i++) {
3307 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3308 
3309 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3310 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3311 		else
3312 			last_block = first_block +
3313 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3314 
3315 		if ((grp == sbi->s_groups_count) &&
3316 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3317 			grp = i;
3318 
3319 		block_bitmap = ext4_block_bitmap(sb, gdp);
3320 		if (block_bitmap == sb_block) {
3321 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3322 				 "Block bitmap for group %u overlaps "
3323 				 "superblock", i);
3324 			if (!sb_rdonly(sb))
3325 				return 0;
3326 		}
3327 		if (block_bitmap >= sb_block + 1 &&
3328 		    block_bitmap <= last_bg_block) {
3329 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3330 				 "Block bitmap for group %u overlaps "
3331 				 "block group descriptors", i);
3332 			if (!sb_rdonly(sb))
3333 				return 0;
3334 		}
3335 		if (block_bitmap < first_block || block_bitmap > last_block) {
3336 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3337 			       "Block bitmap for group %u not in group "
3338 			       "(block %llu)!", i, block_bitmap);
3339 			return 0;
3340 		}
3341 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3342 		if (inode_bitmap == sb_block) {
3343 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3344 				 "Inode bitmap for group %u overlaps "
3345 				 "superblock", i);
3346 			if (!sb_rdonly(sb))
3347 				return 0;
3348 		}
3349 		if (inode_bitmap >= sb_block + 1 &&
3350 		    inode_bitmap <= last_bg_block) {
3351 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3352 				 "Inode bitmap for group %u overlaps "
3353 				 "block group descriptors", i);
3354 			if (!sb_rdonly(sb))
3355 				return 0;
3356 		}
3357 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3358 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3359 			       "Inode bitmap for group %u not in group "
3360 			       "(block %llu)!", i, inode_bitmap);
3361 			return 0;
3362 		}
3363 		inode_table = ext4_inode_table(sb, gdp);
3364 		if (inode_table == sb_block) {
3365 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3366 				 "Inode table for group %u overlaps "
3367 				 "superblock", i);
3368 			if (!sb_rdonly(sb))
3369 				return 0;
3370 		}
3371 		if (inode_table >= sb_block + 1 &&
3372 		    inode_table <= last_bg_block) {
3373 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3374 				 "Inode table for group %u overlaps "
3375 				 "block group descriptors", i);
3376 			if (!sb_rdonly(sb))
3377 				return 0;
3378 		}
3379 		if (inode_table < first_block ||
3380 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3381 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3382 			       "Inode table for group %u not in group "
3383 			       "(block %llu)!", i, inode_table);
3384 			return 0;
3385 		}
3386 		ext4_lock_group(sb, i);
3387 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3388 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3389 				 "Checksum for group %u failed (%u!=%u)",
3390 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3391 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3392 			if (!sb_rdonly(sb)) {
3393 				ext4_unlock_group(sb, i);
3394 				return 0;
3395 			}
3396 		}
3397 		ext4_unlock_group(sb, i);
3398 		if (!flexbg_flag)
3399 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3400 	}
3401 	if (NULL != first_not_zeroed)
3402 		*first_not_zeroed = grp;
3403 	return 1;
3404 }
3405 
3406 /*
3407  * Maximal extent format file size.
3408  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3409  * extent format containers, within a sector_t, and within i_blocks
3410  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3411  * so that won't be a limiting factor.
3412  *
3413  * However there is other limiting factor. We do store extents in the form
3414  * of starting block and length, hence the resulting length of the extent
3415  * covering maximum file size must fit into on-disk format containers as
3416  * well. Given that length is always by 1 unit bigger than max unit (because
3417  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3418  *
3419  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3420  */
3421 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3422 {
3423 	loff_t res;
3424 	loff_t upper_limit = MAX_LFS_FILESIZE;
3425 
3426 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3427 
3428 	if (!has_huge_files) {
3429 		upper_limit = (1LL << 32) - 1;
3430 
3431 		/* total blocks in file system block size */
3432 		upper_limit >>= (blkbits - 9);
3433 		upper_limit <<= blkbits;
3434 	}
3435 
3436 	/*
3437 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3438 	 * by one fs block, so ee_len can cover the extent of maximum file
3439 	 * size
3440 	 */
3441 	res = (1LL << 32) - 1;
3442 	res <<= blkbits;
3443 
3444 	/* Sanity check against vm- & vfs- imposed limits */
3445 	if (res > upper_limit)
3446 		res = upper_limit;
3447 
3448 	return res;
3449 }
3450 
3451 /*
3452  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3453  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3454  * We need to be 1 filesystem block less than the 2^48 sector limit.
3455  */
3456 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3457 {
3458 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3459 	int meta_blocks;
3460 	unsigned int ppb = 1 << (bits - 2);
3461 
3462 	/*
3463 	 * This is calculated to be the largest file size for a dense, block
3464 	 * mapped file such that the file's total number of 512-byte sectors,
3465 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3466 	 *
3467 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3468 	 * number of 512-byte sectors of the file.
3469 	 */
3470 	if (!has_huge_files) {
3471 		/*
3472 		 * !has_huge_files or implies that the inode i_block field
3473 		 * represents total file blocks in 2^32 512-byte sectors ==
3474 		 * size of vfs inode i_blocks * 8
3475 		 */
3476 		upper_limit = (1LL << 32) - 1;
3477 
3478 		/* total blocks in file system block size */
3479 		upper_limit >>= (bits - 9);
3480 
3481 	} else {
3482 		/*
3483 		 * We use 48 bit ext4_inode i_blocks
3484 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3485 		 * represent total number of blocks in
3486 		 * file system block size
3487 		 */
3488 		upper_limit = (1LL << 48) - 1;
3489 
3490 	}
3491 
3492 	/* Compute how many blocks we can address by block tree */
3493 	res += ppb;
3494 	res += ppb * ppb;
3495 	res += ((loff_t)ppb) * ppb * ppb;
3496 	/* Compute how many metadata blocks are needed */
3497 	meta_blocks = 1;
3498 	meta_blocks += 1 + ppb;
3499 	meta_blocks += 1 + ppb + ppb * ppb;
3500 	/* Does block tree limit file size? */
3501 	if (res + meta_blocks <= upper_limit)
3502 		goto check_lfs;
3503 
3504 	res = upper_limit;
3505 	/* How many metadata blocks are needed for addressing upper_limit? */
3506 	upper_limit -= EXT4_NDIR_BLOCKS;
3507 	/* indirect blocks */
3508 	meta_blocks = 1;
3509 	upper_limit -= ppb;
3510 	/* double indirect blocks */
3511 	if (upper_limit < ppb * ppb) {
3512 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3513 		res -= meta_blocks;
3514 		goto check_lfs;
3515 	}
3516 	meta_blocks += 1 + ppb;
3517 	upper_limit -= ppb * ppb;
3518 	/* tripple indirect blocks for the rest */
3519 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3520 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3521 	res -= meta_blocks;
3522 check_lfs:
3523 	res <<= bits;
3524 	if (res > MAX_LFS_FILESIZE)
3525 		res = MAX_LFS_FILESIZE;
3526 
3527 	return res;
3528 }
3529 
3530 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3531 				   ext4_fsblk_t logical_sb_block, int nr)
3532 {
3533 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3534 	ext4_group_t bg, first_meta_bg;
3535 	int has_super = 0;
3536 
3537 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3538 
3539 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3540 		return logical_sb_block + nr + 1;
3541 	bg = sbi->s_desc_per_block * nr;
3542 	if (ext4_bg_has_super(sb, bg))
3543 		has_super = 1;
3544 
3545 	/*
3546 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3547 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3548 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3549 	 * compensate.
3550 	 */
3551 	if (sb->s_blocksize == 1024 && nr == 0 &&
3552 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3553 		has_super++;
3554 
3555 	return (has_super + ext4_group_first_block_no(sb, bg));
3556 }
3557 
3558 /**
3559  * ext4_get_stripe_size: Get the stripe size.
3560  * @sbi: In memory super block info
3561  *
3562  * If we have specified it via mount option, then
3563  * use the mount option value. If the value specified at mount time is
3564  * greater than the blocks per group use the super block value.
3565  * If the super block value is greater than blocks per group return 0.
3566  * Allocator needs it be less than blocks per group.
3567  *
3568  */
3569 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3570 {
3571 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3572 	unsigned long stripe_width =
3573 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3574 	int ret;
3575 
3576 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3577 		ret = sbi->s_stripe;
3578 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3579 		ret = stripe_width;
3580 	else if (stride && stride <= sbi->s_blocks_per_group)
3581 		ret = stride;
3582 	else
3583 		ret = 0;
3584 
3585 	/*
3586 	 * If the stripe width is 1, this makes no sense and
3587 	 * we set it to 0 to turn off stripe handling code.
3588 	 */
3589 	if (ret <= 1)
3590 		ret = 0;
3591 
3592 	return ret;
3593 }
3594 
3595 /*
3596  * Check whether this filesystem can be mounted based on
3597  * the features present and the RDONLY/RDWR mount requested.
3598  * Returns 1 if this filesystem can be mounted as requested,
3599  * 0 if it cannot be.
3600  */
3601 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3602 {
3603 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3604 		ext4_msg(sb, KERN_ERR,
3605 			"Couldn't mount because of "
3606 			"unsupported optional features (%x)",
3607 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3608 			~EXT4_FEATURE_INCOMPAT_SUPP));
3609 		return 0;
3610 	}
3611 
3612 #if !IS_ENABLED(CONFIG_UNICODE)
3613 	if (ext4_has_feature_casefold(sb)) {
3614 		ext4_msg(sb, KERN_ERR,
3615 			 "Filesystem with casefold feature cannot be "
3616 			 "mounted without CONFIG_UNICODE");
3617 		return 0;
3618 	}
3619 #endif
3620 
3621 	if (readonly)
3622 		return 1;
3623 
3624 	if (ext4_has_feature_readonly(sb)) {
3625 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3626 		sb->s_flags |= SB_RDONLY;
3627 		return 1;
3628 	}
3629 
3630 	/* Check that feature set is OK for a read-write mount */
3631 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3632 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3633 			 "unsupported optional features (%x)",
3634 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3635 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3636 		return 0;
3637 	}
3638 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3639 		ext4_msg(sb, KERN_ERR,
3640 			 "Can't support bigalloc feature without "
3641 			 "extents feature\n");
3642 		return 0;
3643 	}
3644 
3645 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3646 	if (!readonly && (ext4_has_feature_quota(sb) ||
3647 			  ext4_has_feature_project(sb))) {
3648 		ext4_msg(sb, KERN_ERR,
3649 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3650 		return 0;
3651 	}
3652 #endif  /* CONFIG_QUOTA */
3653 	return 1;
3654 }
3655 
3656 /*
3657  * This function is called once a day if we have errors logged
3658  * on the file system
3659  */
3660 static void print_daily_error_info(struct timer_list *t)
3661 {
3662 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3663 	struct super_block *sb = sbi->s_sb;
3664 	struct ext4_super_block *es = sbi->s_es;
3665 
3666 	if (es->s_error_count)
3667 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3668 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3669 			 le32_to_cpu(es->s_error_count));
3670 	if (es->s_first_error_time) {
3671 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3672 		       sb->s_id,
3673 		       ext4_get_tstamp(es, s_first_error_time),
3674 		       (int) sizeof(es->s_first_error_func),
3675 		       es->s_first_error_func,
3676 		       le32_to_cpu(es->s_first_error_line));
3677 		if (es->s_first_error_ino)
3678 			printk(KERN_CONT ": inode %u",
3679 			       le32_to_cpu(es->s_first_error_ino));
3680 		if (es->s_first_error_block)
3681 			printk(KERN_CONT ": block %llu", (unsigned long long)
3682 			       le64_to_cpu(es->s_first_error_block));
3683 		printk(KERN_CONT "\n");
3684 	}
3685 	if (es->s_last_error_time) {
3686 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3687 		       sb->s_id,
3688 		       ext4_get_tstamp(es, s_last_error_time),
3689 		       (int) sizeof(es->s_last_error_func),
3690 		       es->s_last_error_func,
3691 		       le32_to_cpu(es->s_last_error_line));
3692 		if (es->s_last_error_ino)
3693 			printk(KERN_CONT ": inode %u",
3694 			       le32_to_cpu(es->s_last_error_ino));
3695 		if (es->s_last_error_block)
3696 			printk(KERN_CONT ": block %llu", (unsigned long long)
3697 			       le64_to_cpu(es->s_last_error_block));
3698 		printk(KERN_CONT "\n");
3699 	}
3700 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3701 }
3702 
3703 /* Find next suitable group and run ext4_init_inode_table */
3704 static int ext4_run_li_request(struct ext4_li_request *elr)
3705 {
3706 	struct ext4_group_desc *gdp = NULL;
3707 	struct super_block *sb = elr->lr_super;
3708 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3709 	ext4_group_t group = elr->lr_next_group;
3710 	unsigned int prefetch_ios = 0;
3711 	int ret = 0;
3712 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3713 	u64 start_time;
3714 
3715 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3716 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3717 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3718 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3719 		if (group >= elr->lr_next_group) {
3720 			ret = 1;
3721 			if (elr->lr_first_not_zeroed != ngroups &&
3722 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3723 				elr->lr_next_group = elr->lr_first_not_zeroed;
3724 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3725 				ret = 0;
3726 			}
3727 		}
3728 		return ret;
3729 	}
3730 
3731 	for (; group < ngroups; group++) {
3732 		gdp = ext4_get_group_desc(sb, group, NULL);
3733 		if (!gdp) {
3734 			ret = 1;
3735 			break;
3736 		}
3737 
3738 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3739 			break;
3740 	}
3741 
3742 	if (group >= ngroups)
3743 		ret = 1;
3744 
3745 	if (!ret) {
3746 		start_time = ktime_get_real_ns();
3747 		ret = ext4_init_inode_table(sb, group,
3748 					    elr->lr_timeout ? 0 : 1);
3749 		trace_ext4_lazy_itable_init(sb, group);
3750 		if (elr->lr_timeout == 0) {
3751 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3752 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3753 		}
3754 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3755 		elr->lr_next_group = group + 1;
3756 	}
3757 	return ret;
3758 }
3759 
3760 /*
3761  * Remove lr_request from the list_request and free the
3762  * request structure. Should be called with li_list_mtx held
3763  */
3764 static void ext4_remove_li_request(struct ext4_li_request *elr)
3765 {
3766 	if (!elr)
3767 		return;
3768 
3769 	list_del(&elr->lr_request);
3770 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3771 	kfree(elr);
3772 }
3773 
3774 static void ext4_unregister_li_request(struct super_block *sb)
3775 {
3776 	mutex_lock(&ext4_li_mtx);
3777 	if (!ext4_li_info) {
3778 		mutex_unlock(&ext4_li_mtx);
3779 		return;
3780 	}
3781 
3782 	mutex_lock(&ext4_li_info->li_list_mtx);
3783 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3784 	mutex_unlock(&ext4_li_info->li_list_mtx);
3785 	mutex_unlock(&ext4_li_mtx);
3786 }
3787 
3788 static struct task_struct *ext4_lazyinit_task;
3789 
3790 /*
3791  * This is the function where ext4lazyinit thread lives. It walks
3792  * through the request list searching for next scheduled filesystem.
3793  * When such a fs is found, run the lazy initialization request
3794  * (ext4_rn_li_request) and keep track of the time spend in this
3795  * function. Based on that time we compute next schedule time of
3796  * the request. When walking through the list is complete, compute
3797  * next waking time and put itself into sleep.
3798  */
3799 static int ext4_lazyinit_thread(void *arg)
3800 {
3801 	struct ext4_lazy_init *eli = arg;
3802 	struct list_head *pos, *n;
3803 	struct ext4_li_request *elr;
3804 	unsigned long next_wakeup, cur;
3805 
3806 	BUG_ON(NULL == eli);
3807 	set_freezable();
3808 
3809 cont_thread:
3810 	while (true) {
3811 		next_wakeup = MAX_JIFFY_OFFSET;
3812 
3813 		mutex_lock(&eli->li_list_mtx);
3814 		if (list_empty(&eli->li_request_list)) {
3815 			mutex_unlock(&eli->li_list_mtx);
3816 			goto exit_thread;
3817 		}
3818 		list_for_each_safe(pos, n, &eli->li_request_list) {
3819 			int err = 0;
3820 			int progress = 0;
3821 			elr = list_entry(pos, struct ext4_li_request,
3822 					 lr_request);
3823 
3824 			if (time_before(jiffies, elr->lr_next_sched)) {
3825 				if (time_before(elr->lr_next_sched, next_wakeup))
3826 					next_wakeup = elr->lr_next_sched;
3827 				continue;
3828 			}
3829 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3830 				if (sb_start_write_trylock(elr->lr_super)) {
3831 					progress = 1;
3832 					/*
3833 					 * We hold sb->s_umount, sb can not
3834 					 * be removed from the list, it is
3835 					 * now safe to drop li_list_mtx
3836 					 */
3837 					mutex_unlock(&eli->li_list_mtx);
3838 					err = ext4_run_li_request(elr);
3839 					sb_end_write(elr->lr_super);
3840 					mutex_lock(&eli->li_list_mtx);
3841 					n = pos->next;
3842 				}
3843 				up_read((&elr->lr_super->s_umount));
3844 			}
3845 			/* error, remove the lazy_init job */
3846 			if (err) {
3847 				ext4_remove_li_request(elr);
3848 				continue;
3849 			}
3850 			if (!progress) {
3851 				elr->lr_next_sched = jiffies +
3852 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3853 			}
3854 			if (time_before(elr->lr_next_sched, next_wakeup))
3855 				next_wakeup = elr->lr_next_sched;
3856 		}
3857 		mutex_unlock(&eli->li_list_mtx);
3858 
3859 		try_to_freeze();
3860 
3861 		cur = jiffies;
3862 		if ((time_after_eq(cur, next_wakeup)) ||
3863 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3864 			cond_resched();
3865 			continue;
3866 		}
3867 
3868 		schedule_timeout_interruptible(next_wakeup - cur);
3869 
3870 		if (kthread_should_stop()) {
3871 			ext4_clear_request_list();
3872 			goto exit_thread;
3873 		}
3874 	}
3875 
3876 exit_thread:
3877 	/*
3878 	 * It looks like the request list is empty, but we need
3879 	 * to check it under the li_list_mtx lock, to prevent any
3880 	 * additions into it, and of course we should lock ext4_li_mtx
3881 	 * to atomically free the list and ext4_li_info, because at
3882 	 * this point another ext4 filesystem could be registering
3883 	 * new one.
3884 	 */
3885 	mutex_lock(&ext4_li_mtx);
3886 	mutex_lock(&eli->li_list_mtx);
3887 	if (!list_empty(&eli->li_request_list)) {
3888 		mutex_unlock(&eli->li_list_mtx);
3889 		mutex_unlock(&ext4_li_mtx);
3890 		goto cont_thread;
3891 	}
3892 	mutex_unlock(&eli->li_list_mtx);
3893 	kfree(ext4_li_info);
3894 	ext4_li_info = NULL;
3895 	mutex_unlock(&ext4_li_mtx);
3896 
3897 	return 0;
3898 }
3899 
3900 static void ext4_clear_request_list(void)
3901 {
3902 	struct list_head *pos, *n;
3903 	struct ext4_li_request *elr;
3904 
3905 	mutex_lock(&ext4_li_info->li_list_mtx);
3906 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3907 		elr = list_entry(pos, struct ext4_li_request,
3908 				 lr_request);
3909 		ext4_remove_li_request(elr);
3910 	}
3911 	mutex_unlock(&ext4_li_info->li_list_mtx);
3912 }
3913 
3914 static int ext4_run_lazyinit_thread(void)
3915 {
3916 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3917 					 ext4_li_info, "ext4lazyinit");
3918 	if (IS_ERR(ext4_lazyinit_task)) {
3919 		int err = PTR_ERR(ext4_lazyinit_task);
3920 		ext4_clear_request_list();
3921 		kfree(ext4_li_info);
3922 		ext4_li_info = NULL;
3923 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3924 				 "initialization thread\n",
3925 				 err);
3926 		return err;
3927 	}
3928 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3929 	return 0;
3930 }
3931 
3932 /*
3933  * Check whether it make sense to run itable init. thread or not.
3934  * If there is at least one uninitialized inode table, return
3935  * corresponding group number, else the loop goes through all
3936  * groups and return total number of groups.
3937  */
3938 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3939 {
3940 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3941 	struct ext4_group_desc *gdp = NULL;
3942 
3943 	if (!ext4_has_group_desc_csum(sb))
3944 		return ngroups;
3945 
3946 	for (group = 0; group < ngroups; group++) {
3947 		gdp = ext4_get_group_desc(sb, group, NULL);
3948 		if (!gdp)
3949 			continue;
3950 
3951 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3952 			break;
3953 	}
3954 
3955 	return group;
3956 }
3957 
3958 static int ext4_li_info_new(void)
3959 {
3960 	struct ext4_lazy_init *eli = NULL;
3961 
3962 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3963 	if (!eli)
3964 		return -ENOMEM;
3965 
3966 	INIT_LIST_HEAD(&eli->li_request_list);
3967 	mutex_init(&eli->li_list_mtx);
3968 
3969 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3970 
3971 	ext4_li_info = eli;
3972 
3973 	return 0;
3974 }
3975 
3976 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3977 					    ext4_group_t start)
3978 {
3979 	struct ext4_li_request *elr;
3980 
3981 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3982 	if (!elr)
3983 		return NULL;
3984 
3985 	elr->lr_super = sb;
3986 	elr->lr_first_not_zeroed = start;
3987 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3988 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3989 		elr->lr_next_group = start;
3990 	} else {
3991 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3992 	}
3993 
3994 	/*
3995 	 * Randomize first schedule time of the request to
3996 	 * spread the inode table initialization requests
3997 	 * better.
3998 	 */
3999 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
4000 	return elr;
4001 }
4002 
4003 int ext4_register_li_request(struct super_block *sb,
4004 			     ext4_group_t first_not_zeroed)
4005 {
4006 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4007 	struct ext4_li_request *elr = NULL;
4008 	ext4_group_t ngroups = sbi->s_groups_count;
4009 	int ret = 0;
4010 
4011 	mutex_lock(&ext4_li_mtx);
4012 	if (sbi->s_li_request != NULL) {
4013 		/*
4014 		 * Reset timeout so it can be computed again, because
4015 		 * s_li_wait_mult might have changed.
4016 		 */
4017 		sbi->s_li_request->lr_timeout = 0;
4018 		goto out;
4019 	}
4020 
4021 	if (sb_rdonly(sb) ||
4022 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4023 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4024 		goto out;
4025 
4026 	elr = ext4_li_request_new(sb, first_not_zeroed);
4027 	if (!elr) {
4028 		ret = -ENOMEM;
4029 		goto out;
4030 	}
4031 
4032 	if (NULL == ext4_li_info) {
4033 		ret = ext4_li_info_new();
4034 		if (ret)
4035 			goto out;
4036 	}
4037 
4038 	mutex_lock(&ext4_li_info->li_list_mtx);
4039 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4040 	mutex_unlock(&ext4_li_info->li_list_mtx);
4041 
4042 	sbi->s_li_request = elr;
4043 	/*
4044 	 * set elr to NULL here since it has been inserted to
4045 	 * the request_list and the removal and free of it is
4046 	 * handled by ext4_clear_request_list from now on.
4047 	 */
4048 	elr = NULL;
4049 
4050 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4051 		ret = ext4_run_lazyinit_thread();
4052 		if (ret)
4053 			goto out;
4054 	}
4055 out:
4056 	mutex_unlock(&ext4_li_mtx);
4057 	if (ret)
4058 		kfree(elr);
4059 	return ret;
4060 }
4061 
4062 /*
4063  * We do not need to lock anything since this is called on
4064  * module unload.
4065  */
4066 static void ext4_destroy_lazyinit_thread(void)
4067 {
4068 	/*
4069 	 * If thread exited earlier
4070 	 * there's nothing to be done.
4071 	 */
4072 	if (!ext4_li_info || !ext4_lazyinit_task)
4073 		return;
4074 
4075 	kthread_stop(ext4_lazyinit_task);
4076 }
4077 
4078 static int set_journal_csum_feature_set(struct super_block *sb)
4079 {
4080 	int ret = 1;
4081 	int compat, incompat;
4082 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4083 
4084 	if (ext4_has_metadata_csum(sb)) {
4085 		/* journal checksum v3 */
4086 		compat = 0;
4087 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4088 	} else {
4089 		/* journal checksum v1 */
4090 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4091 		incompat = 0;
4092 	}
4093 
4094 	jbd2_journal_clear_features(sbi->s_journal,
4095 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4096 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4097 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4098 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4099 		ret = jbd2_journal_set_features(sbi->s_journal,
4100 				compat, 0,
4101 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4102 				incompat);
4103 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4104 		ret = jbd2_journal_set_features(sbi->s_journal,
4105 				compat, 0,
4106 				incompat);
4107 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4108 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4109 	} else {
4110 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4111 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4112 	}
4113 
4114 	return ret;
4115 }
4116 
4117 /*
4118  * Note: calculating the overhead so we can be compatible with
4119  * historical BSD practice is quite difficult in the face of
4120  * clusters/bigalloc.  This is because multiple metadata blocks from
4121  * different block group can end up in the same allocation cluster.
4122  * Calculating the exact overhead in the face of clustered allocation
4123  * requires either O(all block bitmaps) in memory or O(number of block
4124  * groups**2) in time.  We will still calculate the superblock for
4125  * older file systems --- and if we come across with a bigalloc file
4126  * system with zero in s_overhead_clusters the estimate will be close to
4127  * correct especially for very large cluster sizes --- but for newer
4128  * file systems, it's better to calculate this figure once at mkfs
4129  * time, and store it in the superblock.  If the superblock value is
4130  * present (even for non-bigalloc file systems), we will use it.
4131  */
4132 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4133 			  char *buf)
4134 {
4135 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4136 	struct ext4_group_desc	*gdp;
4137 	ext4_fsblk_t		first_block, last_block, b;
4138 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4139 	int			s, j, count = 0;
4140 	int			has_super = ext4_bg_has_super(sb, grp);
4141 
4142 	if (!ext4_has_feature_bigalloc(sb))
4143 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4144 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4145 			sbi->s_itb_per_group + 2);
4146 
4147 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4148 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4149 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4150 	for (i = 0; i < ngroups; i++) {
4151 		gdp = ext4_get_group_desc(sb, i, NULL);
4152 		b = ext4_block_bitmap(sb, gdp);
4153 		if (b >= first_block && b <= last_block) {
4154 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4155 			count++;
4156 		}
4157 		b = ext4_inode_bitmap(sb, gdp);
4158 		if (b >= first_block && b <= last_block) {
4159 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4160 			count++;
4161 		}
4162 		b = ext4_inode_table(sb, gdp);
4163 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4164 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4165 				int c = EXT4_B2C(sbi, b - first_block);
4166 				ext4_set_bit(c, buf);
4167 				count++;
4168 			}
4169 		if (i != grp)
4170 			continue;
4171 		s = 0;
4172 		if (ext4_bg_has_super(sb, grp)) {
4173 			ext4_set_bit(s++, buf);
4174 			count++;
4175 		}
4176 		j = ext4_bg_num_gdb(sb, grp);
4177 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4178 			ext4_error(sb, "Invalid number of block group "
4179 				   "descriptor blocks: %d", j);
4180 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4181 		}
4182 		count += j;
4183 		for (; j > 0; j--)
4184 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4185 	}
4186 	if (!count)
4187 		return 0;
4188 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4189 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4190 }
4191 
4192 /*
4193  * Compute the overhead and stash it in sbi->s_overhead
4194  */
4195 int ext4_calculate_overhead(struct super_block *sb)
4196 {
4197 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4198 	struct ext4_super_block *es = sbi->s_es;
4199 	struct inode *j_inode;
4200 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4201 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4202 	ext4_fsblk_t overhead = 0;
4203 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4204 
4205 	if (!buf)
4206 		return -ENOMEM;
4207 
4208 	/*
4209 	 * Compute the overhead (FS structures).  This is constant
4210 	 * for a given filesystem unless the number of block groups
4211 	 * changes so we cache the previous value until it does.
4212 	 */
4213 
4214 	/*
4215 	 * All of the blocks before first_data_block are overhead
4216 	 */
4217 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4218 
4219 	/*
4220 	 * Add the overhead found in each block group
4221 	 */
4222 	for (i = 0; i < ngroups; i++) {
4223 		int blks;
4224 
4225 		blks = count_overhead(sb, i, buf);
4226 		overhead += blks;
4227 		if (blks)
4228 			memset(buf, 0, PAGE_SIZE);
4229 		cond_resched();
4230 	}
4231 
4232 	/*
4233 	 * Add the internal journal blocks whether the journal has been
4234 	 * loaded or not
4235 	 */
4236 	if (sbi->s_journal && !sbi->s_journal_bdev)
4237 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4238 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4239 		/* j_inum for internal journal is non-zero */
4240 		j_inode = ext4_get_journal_inode(sb, j_inum);
4241 		if (!IS_ERR(j_inode)) {
4242 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4243 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4244 			iput(j_inode);
4245 		} else {
4246 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4247 		}
4248 	}
4249 	sbi->s_overhead = overhead;
4250 	smp_wmb();
4251 	free_page((unsigned long) buf);
4252 	return 0;
4253 }
4254 
4255 static void ext4_set_resv_clusters(struct super_block *sb)
4256 {
4257 	ext4_fsblk_t resv_clusters;
4258 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4259 
4260 	/*
4261 	 * There's no need to reserve anything when we aren't using extents.
4262 	 * The space estimates are exact, there are no unwritten extents,
4263 	 * hole punching doesn't need new metadata... This is needed especially
4264 	 * to keep ext2/3 backward compatibility.
4265 	 */
4266 	if (!ext4_has_feature_extents(sb))
4267 		return;
4268 	/*
4269 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4270 	 * This should cover the situations where we can not afford to run
4271 	 * out of space like for example punch hole, or converting
4272 	 * unwritten extents in delalloc path. In most cases such
4273 	 * allocation would require 1, or 2 blocks, higher numbers are
4274 	 * very rare.
4275 	 */
4276 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4277 			 sbi->s_cluster_bits);
4278 
4279 	do_div(resv_clusters, 50);
4280 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4281 
4282 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4283 }
4284 
4285 static const char *ext4_quota_mode(struct super_block *sb)
4286 {
4287 #ifdef CONFIG_QUOTA
4288 	if (!ext4_quota_capable(sb))
4289 		return "none";
4290 
4291 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4292 		return "journalled";
4293 	else
4294 		return "writeback";
4295 #else
4296 	return "disabled";
4297 #endif
4298 }
4299 
4300 static void ext4_setup_csum_trigger(struct super_block *sb,
4301 				    enum ext4_journal_trigger_type type,
4302 				    void (*trigger)(
4303 					struct jbd2_buffer_trigger_type *type,
4304 					struct buffer_head *bh,
4305 					void *mapped_data,
4306 					size_t size))
4307 {
4308 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4309 
4310 	sbi->s_journal_triggers[type].sb = sb;
4311 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4312 }
4313 
4314 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4315 {
4316 	if (!sbi)
4317 		return;
4318 
4319 	kfree(sbi->s_blockgroup_lock);
4320 	fs_put_dax(sbi->s_daxdev, NULL);
4321 	kfree(sbi);
4322 }
4323 
4324 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4325 {
4326 	struct ext4_sb_info *sbi;
4327 
4328 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4329 	if (!sbi)
4330 		return NULL;
4331 
4332 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4333 					   NULL, NULL);
4334 
4335 	sbi->s_blockgroup_lock =
4336 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4337 
4338 	if (!sbi->s_blockgroup_lock)
4339 		goto err_out;
4340 
4341 	sb->s_fs_info = sbi;
4342 	sbi->s_sb = sb;
4343 	return sbi;
4344 err_out:
4345 	fs_put_dax(sbi->s_daxdev, NULL);
4346 	kfree(sbi);
4347 	return NULL;
4348 }
4349 
4350 static void ext4_set_def_opts(struct super_block *sb,
4351 			      struct ext4_super_block *es)
4352 {
4353 	unsigned long def_mount_opts;
4354 
4355 	/* Set defaults before we parse the mount options */
4356 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4357 	set_opt(sb, INIT_INODE_TABLE);
4358 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4359 		set_opt(sb, DEBUG);
4360 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4361 		set_opt(sb, GRPID);
4362 	if (def_mount_opts & EXT4_DEFM_UID16)
4363 		set_opt(sb, NO_UID32);
4364 	/* xattr user namespace & acls are now defaulted on */
4365 	set_opt(sb, XATTR_USER);
4366 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4367 	set_opt(sb, POSIX_ACL);
4368 #endif
4369 	if (ext4_has_feature_fast_commit(sb))
4370 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4371 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4372 	if (ext4_has_metadata_csum(sb))
4373 		set_opt(sb, JOURNAL_CHECKSUM);
4374 
4375 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4376 		set_opt(sb, JOURNAL_DATA);
4377 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4378 		set_opt(sb, ORDERED_DATA);
4379 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4380 		set_opt(sb, WRITEBACK_DATA);
4381 
4382 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4383 		set_opt(sb, ERRORS_PANIC);
4384 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4385 		set_opt(sb, ERRORS_CONT);
4386 	else
4387 		set_opt(sb, ERRORS_RO);
4388 	/* block_validity enabled by default; disable with noblock_validity */
4389 	set_opt(sb, BLOCK_VALIDITY);
4390 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4391 		set_opt(sb, DISCARD);
4392 
4393 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4394 		set_opt(sb, BARRIER);
4395 
4396 	/*
4397 	 * enable delayed allocation by default
4398 	 * Use -o nodelalloc to turn it off
4399 	 */
4400 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4401 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4402 		set_opt(sb, DELALLOC);
4403 
4404 	if (sb->s_blocksize == PAGE_SIZE)
4405 		set_opt(sb, DIOREAD_NOLOCK);
4406 }
4407 
4408 static int ext4_handle_clustersize(struct super_block *sb)
4409 {
4410 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4411 	struct ext4_super_block *es = sbi->s_es;
4412 	int clustersize;
4413 
4414 	/* Handle clustersize */
4415 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4416 	if (ext4_has_feature_bigalloc(sb)) {
4417 		if (clustersize < sb->s_blocksize) {
4418 			ext4_msg(sb, KERN_ERR,
4419 				 "cluster size (%d) smaller than "
4420 				 "block size (%lu)", clustersize, sb->s_blocksize);
4421 			return -EINVAL;
4422 		}
4423 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4424 			le32_to_cpu(es->s_log_block_size);
4425 		sbi->s_clusters_per_group =
4426 			le32_to_cpu(es->s_clusters_per_group);
4427 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4428 			ext4_msg(sb, KERN_ERR,
4429 				 "#clusters per group too big: %lu",
4430 				 sbi->s_clusters_per_group);
4431 			return -EINVAL;
4432 		}
4433 		if (sbi->s_blocks_per_group !=
4434 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4435 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4436 				 "clusters per group (%lu) inconsistent",
4437 				 sbi->s_blocks_per_group,
4438 				 sbi->s_clusters_per_group);
4439 			return -EINVAL;
4440 		}
4441 	} else {
4442 		if (clustersize != sb->s_blocksize) {
4443 			ext4_msg(sb, KERN_ERR,
4444 				 "fragment/cluster size (%d) != "
4445 				 "block size (%lu)", clustersize, sb->s_blocksize);
4446 			return -EINVAL;
4447 		}
4448 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4449 			ext4_msg(sb, KERN_ERR,
4450 				 "#blocks per group too big: %lu",
4451 				 sbi->s_blocks_per_group);
4452 			return -EINVAL;
4453 		}
4454 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4455 		sbi->s_cluster_bits = 0;
4456 	}
4457 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4458 
4459 	/* Do we have standard group size of clustersize * 8 blocks ? */
4460 	if (sbi->s_blocks_per_group == clustersize << 3)
4461 		set_opt2(sb, STD_GROUP_SIZE);
4462 
4463 	return 0;
4464 }
4465 
4466 static void ext4_fast_commit_init(struct super_block *sb)
4467 {
4468 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4469 
4470 	/* Initialize fast commit stuff */
4471 	atomic_set(&sbi->s_fc_subtid, 0);
4472 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4473 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4474 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4475 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4476 	sbi->s_fc_bytes = 0;
4477 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4478 	sbi->s_fc_ineligible_tid = 0;
4479 	spin_lock_init(&sbi->s_fc_lock);
4480 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4481 	sbi->s_fc_replay_state.fc_regions = NULL;
4482 	sbi->s_fc_replay_state.fc_regions_size = 0;
4483 	sbi->s_fc_replay_state.fc_regions_used = 0;
4484 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4485 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4486 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4487 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4488 }
4489 
4490 static int ext4_inode_info_init(struct super_block *sb,
4491 				struct ext4_super_block *es)
4492 {
4493 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4494 
4495 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4496 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4497 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4498 	} else {
4499 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4500 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4501 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4502 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4503 				 sbi->s_first_ino);
4504 			return -EINVAL;
4505 		}
4506 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4507 		    (!is_power_of_2(sbi->s_inode_size)) ||
4508 		    (sbi->s_inode_size > sb->s_blocksize)) {
4509 			ext4_msg(sb, KERN_ERR,
4510 			       "unsupported inode size: %d",
4511 			       sbi->s_inode_size);
4512 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4513 			return -EINVAL;
4514 		}
4515 		/*
4516 		 * i_atime_extra is the last extra field available for
4517 		 * [acm]times in struct ext4_inode. Checking for that
4518 		 * field should suffice to ensure we have extra space
4519 		 * for all three.
4520 		 */
4521 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4522 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4523 			sb->s_time_gran = 1;
4524 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4525 		} else {
4526 			sb->s_time_gran = NSEC_PER_SEC;
4527 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4528 		}
4529 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4530 	}
4531 
4532 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4533 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4534 			EXT4_GOOD_OLD_INODE_SIZE;
4535 		if (ext4_has_feature_extra_isize(sb)) {
4536 			unsigned v, max = (sbi->s_inode_size -
4537 					   EXT4_GOOD_OLD_INODE_SIZE);
4538 
4539 			v = le16_to_cpu(es->s_want_extra_isize);
4540 			if (v > max) {
4541 				ext4_msg(sb, KERN_ERR,
4542 					 "bad s_want_extra_isize: %d", v);
4543 				return -EINVAL;
4544 			}
4545 			if (sbi->s_want_extra_isize < v)
4546 				sbi->s_want_extra_isize = v;
4547 
4548 			v = le16_to_cpu(es->s_min_extra_isize);
4549 			if (v > max) {
4550 				ext4_msg(sb, KERN_ERR,
4551 					 "bad s_min_extra_isize: %d", v);
4552 				return -EINVAL;
4553 			}
4554 			if (sbi->s_want_extra_isize < v)
4555 				sbi->s_want_extra_isize = v;
4556 		}
4557 	}
4558 
4559 	return 0;
4560 }
4561 
4562 #if IS_ENABLED(CONFIG_UNICODE)
4563 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4564 {
4565 	const struct ext4_sb_encodings *encoding_info;
4566 	struct unicode_map *encoding;
4567 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4568 
4569 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4570 		return 0;
4571 
4572 	encoding_info = ext4_sb_read_encoding(es);
4573 	if (!encoding_info) {
4574 		ext4_msg(sb, KERN_ERR,
4575 			"Encoding requested by superblock is unknown");
4576 		return -EINVAL;
4577 	}
4578 
4579 	encoding = utf8_load(encoding_info->version);
4580 	if (IS_ERR(encoding)) {
4581 		ext4_msg(sb, KERN_ERR,
4582 			"can't mount with superblock charset: %s-%u.%u.%u "
4583 			"not supported by the kernel. flags: 0x%x.",
4584 			encoding_info->name,
4585 			unicode_major(encoding_info->version),
4586 			unicode_minor(encoding_info->version),
4587 			unicode_rev(encoding_info->version),
4588 			encoding_flags);
4589 		return -EINVAL;
4590 	}
4591 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4592 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4593 		unicode_major(encoding_info->version),
4594 		unicode_minor(encoding_info->version),
4595 		unicode_rev(encoding_info->version),
4596 		encoding_flags);
4597 
4598 	sb->s_encoding = encoding;
4599 	sb->s_encoding_flags = encoding_flags;
4600 
4601 	return 0;
4602 }
4603 #else
4604 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4605 {
4606 	return 0;
4607 }
4608 #endif
4609 
4610 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4611 {
4612 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4613 
4614 	/* Warn if metadata_csum and gdt_csum are both set. */
4615 	if (ext4_has_feature_metadata_csum(sb) &&
4616 	    ext4_has_feature_gdt_csum(sb))
4617 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4618 			     "redundant flags; please run fsck.");
4619 
4620 	/* Check for a known checksum algorithm */
4621 	if (!ext4_verify_csum_type(sb, es)) {
4622 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4623 			 "unknown checksum algorithm.");
4624 		return -EINVAL;
4625 	}
4626 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4627 				ext4_orphan_file_block_trigger);
4628 
4629 	/* Load the checksum driver */
4630 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4631 	if (IS_ERR(sbi->s_chksum_driver)) {
4632 		int ret = PTR_ERR(sbi->s_chksum_driver);
4633 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4634 		sbi->s_chksum_driver = NULL;
4635 		return ret;
4636 	}
4637 
4638 	/* Check superblock checksum */
4639 	if (!ext4_superblock_csum_verify(sb, es)) {
4640 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4641 			 "invalid superblock checksum.  Run e2fsck?");
4642 		return -EFSBADCRC;
4643 	}
4644 
4645 	/* Precompute checksum seed for all metadata */
4646 	if (ext4_has_feature_csum_seed(sb))
4647 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4648 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4649 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4650 					       sizeof(es->s_uuid));
4651 	return 0;
4652 }
4653 
4654 static int ext4_check_feature_compatibility(struct super_block *sb,
4655 					    struct ext4_super_block *es,
4656 					    int silent)
4657 {
4658 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4659 
4660 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4661 	    (ext4_has_compat_features(sb) ||
4662 	     ext4_has_ro_compat_features(sb) ||
4663 	     ext4_has_incompat_features(sb)))
4664 		ext4_msg(sb, KERN_WARNING,
4665 		       "feature flags set on rev 0 fs, "
4666 		       "running e2fsck is recommended");
4667 
4668 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4669 		set_opt2(sb, HURD_COMPAT);
4670 		if (ext4_has_feature_64bit(sb)) {
4671 			ext4_msg(sb, KERN_ERR,
4672 				 "The Hurd can't support 64-bit file systems");
4673 			return -EINVAL;
4674 		}
4675 
4676 		/*
4677 		 * ea_inode feature uses l_i_version field which is not
4678 		 * available in HURD_COMPAT mode.
4679 		 */
4680 		if (ext4_has_feature_ea_inode(sb)) {
4681 			ext4_msg(sb, KERN_ERR,
4682 				 "ea_inode feature is not supported for Hurd");
4683 			return -EINVAL;
4684 		}
4685 	}
4686 
4687 	if (IS_EXT2_SB(sb)) {
4688 		if (ext2_feature_set_ok(sb))
4689 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4690 				 "using the ext4 subsystem");
4691 		else {
4692 			/*
4693 			 * If we're probing be silent, if this looks like
4694 			 * it's actually an ext[34] filesystem.
4695 			 */
4696 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4697 				return -EINVAL;
4698 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4699 				 "to feature incompatibilities");
4700 			return -EINVAL;
4701 		}
4702 	}
4703 
4704 	if (IS_EXT3_SB(sb)) {
4705 		if (ext3_feature_set_ok(sb))
4706 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4707 				 "using the ext4 subsystem");
4708 		else {
4709 			/*
4710 			 * If we're probing be silent, if this looks like
4711 			 * it's actually an ext4 filesystem.
4712 			 */
4713 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4714 				return -EINVAL;
4715 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4716 				 "to feature incompatibilities");
4717 			return -EINVAL;
4718 		}
4719 	}
4720 
4721 	/*
4722 	 * Check feature flags regardless of the revision level, since we
4723 	 * previously didn't change the revision level when setting the flags,
4724 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4725 	 */
4726 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4727 		return -EINVAL;
4728 
4729 	if (sbi->s_daxdev) {
4730 		if (sb->s_blocksize == PAGE_SIZE)
4731 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4732 		else
4733 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4734 	}
4735 
4736 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4737 		if (ext4_has_feature_inline_data(sb)) {
4738 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4739 					" that may contain inline data");
4740 			return -EINVAL;
4741 		}
4742 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4743 			ext4_msg(sb, KERN_ERR,
4744 				"DAX unsupported by block device.");
4745 			return -EINVAL;
4746 		}
4747 	}
4748 
4749 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4750 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4751 			 es->s_encryption_level);
4752 		return -EINVAL;
4753 	}
4754 
4755 	return 0;
4756 }
4757 
4758 static int ext4_check_geometry(struct super_block *sb,
4759 			       struct ext4_super_block *es)
4760 {
4761 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4762 	__u64 blocks_count;
4763 	int err;
4764 
4765 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4766 		ext4_msg(sb, KERN_ERR,
4767 			 "Number of reserved GDT blocks insanely large: %d",
4768 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4769 		return -EINVAL;
4770 	}
4771 	/*
4772 	 * Test whether we have more sectors than will fit in sector_t,
4773 	 * and whether the max offset is addressable by the page cache.
4774 	 */
4775 	err = generic_check_addressable(sb->s_blocksize_bits,
4776 					ext4_blocks_count(es));
4777 	if (err) {
4778 		ext4_msg(sb, KERN_ERR, "filesystem"
4779 			 " too large to mount safely on this system");
4780 		return err;
4781 	}
4782 
4783 	/* check blocks count against device size */
4784 	blocks_count = sb_bdev_nr_blocks(sb);
4785 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4786 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4787 		       "exceeds size of device (%llu blocks)",
4788 		       ext4_blocks_count(es), blocks_count);
4789 		return -EINVAL;
4790 	}
4791 
4792 	/*
4793 	 * It makes no sense for the first data block to be beyond the end
4794 	 * of the filesystem.
4795 	 */
4796 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4797 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4798 			 "block %u is beyond end of filesystem (%llu)",
4799 			 le32_to_cpu(es->s_first_data_block),
4800 			 ext4_blocks_count(es));
4801 		return -EINVAL;
4802 	}
4803 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4804 	    (sbi->s_cluster_ratio == 1)) {
4805 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4806 			 "block is 0 with a 1k block and cluster size");
4807 		return -EINVAL;
4808 	}
4809 
4810 	blocks_count = (ext4_blocks_count(es) -
4811 			le32_to_cpu(es->s_first_data_block) +
4812 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4813 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4814 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4815 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4816 		       "(block count %llu, first data block %u, "
4817 		       "blocks per group %lu)", blocks_count,
4818 		       ext4_blocks_count(es),
4819 		       le32_to_cpu(es->s_first_data_block),
4820 		       EXT4_BLOCKS_PER_GROUP(sb));
4821 		return -EINVAL;
4822 	}
4823 	sbi->s_groups_count = blocks_count;
4824 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4825 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4826 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4827 	    le32_to_cpu(es->s_inodes_count)) {
4828 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4829 			 le32_to_cpu(es->s_inodes_count),
4830 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4831 		return -EINVAL;
4832 	}
4833 
4834 	return 0;
4835 }
4836 
4837 static int ext4_group_desc_init(struct super_block *sb,
4838 				struct ext4_super_block *es,
4839 				ext4_fsblk_t logical_sb_block,
4840 				ext4_group_t *first_not_zeroed)
4841 {
4842 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4843 	unsigned int db_count;
4844 	ext4_fsblk_t block;
4845 	int i;
4846 
4847 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4848 		   EXT4_DESC_PER_BLOCK(sb);
4849 	if (ext4_has_feature_meta_bg(sb)) {
4850 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4851 			ext4_msg(sb, KERN_WARNING,
4852 				 "first meta block group too large: %u "
4853 				 "(group descriptor block count %u)",
4854 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4855 			return -EINVAL;
4856 		}
4857 	}
4858 	rcu_assign_pointer(sbi->s_group_desc,
4859 			   kvmalloc_array(db_count,
4860 					  sizeof(struct buffer_head *),
4861 					  GFP_KERNEL));
4862 	if (sbi->s_group_desc == NULL) {
4863 		ext4_msg(sb, KERN_ERR, "not enough memory");
4864 		return -ENOMEM;
4865 	}
4866 
4867 	bgl_lock_init(sbi->s_blockgroup_lock);
4868 
4869 	/* Pre-read the descriptors into the buffer cache */
4870 	for (i = 0; i < db_count; i++) {
4871 		block = descriptor_loc(sb, logical_sb_block, i);
4872 		ext4_sb_breadahead_unmovable(sb, block);
4873 	}
4874 
4875 	for (i = 0; i < db_count; i++) {
4876 		struct buffer_head *bh;
4877 
4878 		block = descriptor_loc(sb, logical_sb_block, i);
4879 		bh = ext4_sb_bread_unmovable(sb, block);
4880 		if (IS_ERR(bh)) {
4881 			ext4_msg(sb, KERN_ERR,
4882 			       "can't read group descriptor %d", i);
4883 			sbi->s_gdb_count = i;
4884 			return PTR_ERR(bh);
4885 		}
4886 		rcu_read_lock();
4887 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4888 		rcu_read_unlock();
4889 	}
4890 	sbi->s_gdb_count = db_count;
4891 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4892 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4893 		return -EFSCORRUPTED;
4894 	}
4895 
4896 	return 0;
4897 }
4898 
4899 static int ext4_load_and_init_journal(struct super_block *sb,
4900 				      struct ext4_super_block *es,
4901 				      struct ext4_fs_context *ctx)
4902 {
4903 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4904 	int err;
4905 
4906 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4907 	if (err)
4908 		return err;
4909 
4910 	if (ext4_has_feature_64bit(sb) &&
4911 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4912 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4913 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4914 		goto out;
4915 	}
4916 
4917 	if (!set_journal_csum_feature_set(sb)) {
4918 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4919 			 "feature set");
4920 		goto out;
4921 	}
4922 
4923 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4924 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4925 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4926 		ext4_msg(sb, KERN_ERR,
4927 			"Failed to set fast commit journal feature");
4928 		goto out;
4929 	}
4930 
4931 	/* We have now updated the journal if required, so we can
4932 	 * validate the data journaling mode. */
4933 	switch (test_opt(sb, DATA_FLAGS)) {
4934 	case 0:
4935 		/* No mode set, assume a default based on the journal
4936 		 * capabilities: ORDERED_DATA if the journal can
4937 		 * cope, else JOURNAL_DATA
4938 		 */
4939 		if (jbd2_journal_check_available_features
4940 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4941 			set_opt(sb, ORDERED_DATA);
4942 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4943 		} else {
4944 			set_opt(sb, JOURNAL_DATA);
4945 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4946 		}
4947 		break;
4948 
4949 	case EXT4_MOUNT_ORDERED_DATA:
4950 	case EXT4_MOUNT_WRITEBACK_DATA:
4951 		if (!jbd2_journal_check_available_features
4952 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4953 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4954 			       "requested data journaling mode");
4955 			goto out;
4956 		}
4957 		break;
4958 	default:
4959 		break;
4960 	}
4961 
4962 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4963 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4964 		ext4_msg(sb, KERN_ERR, "can't mount with "
4965 			"journal_async_commit in data=ordered mode");
4966 		goto out;
4967 	}
4968 
4969 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4970 
4971 	sbi->s_journal->j_submit_inode_data_buffers =
4972 		ext4_journal_submit_inode_data_buffers;
4973 	sbi->s_journal->j_finish_inode_data_buffers =
4974 		ext4_journal_finish_inode_data_buffers;
4975 
4976 	return 0;
4977 
4978 out:
4979 	/* flush s_sb_upd_work before destroying the journal. */
4980 	flush_work(&sbi->s_sb_upd_work);
4981 	jbd2_journal_destroy(sbi->s_journal);
4982 	sbi->s_journal = NULL;
4983 	return -EINVAL;
4984 }
4985 
4986 static int ext4_check_journal_data_mode(struct super_block *sb)
4987 {
4988 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4989 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4990 			    "data=journal disables delayed allocation, "
4991 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
4992 		/* can't mount with both data=journal and dioread_nolock. */
4993 		clear_opt(sb, DIOREAD_NOLOCK);
4994 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4995 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4996 			ext4_msg(sb, KERN_ERR, "can't mount with "
4997 				 "both data=journal and delalloc");
4998 			return -EINVAL;
4999 		}
5000 		if (test_opt(sb, DAX_ALWAYS)) {
5001 			ext4_msg(sb, KERN_ERR, "can't mount with "
5002 				 "both data=journal and dax");
5003 			return -EINVAL;
5004 		}
5005 		if (ext4_has_feature_encrypt(sb)) {
5006 			ext4_msg(sb, KERN_WARNING,
5007 				 "encrypted files will use data=ordered "
5008 				 "instead of data journaling mode");
5009 		}
5010 		if (test_opt(sb, DELALLOC))
5011 			clear_opt(sb, DELALLOC);
5012 	} else {
5013 		sb->s_iflags |= SB_I_CGROUPWB;
5014 	}
5015 
5016 	return 0;
5017 }
5018 
5019 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5020 			   int silent)
5021 {
5022 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5023 	struct ext4_super_block *es;
5024 	ext4_fsblk_t logical_sb_block;
5025 	unsigned long offset = 0;
5026 	struct buffer_head *bh;
5027 	int ret = -EINVAL;
5028 	int blocksize;
5029 
5030 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5031 	if (!blocksize) {
5032 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5033 		return -EINVAL;
5034 	}
5035 
5036 	/*
5037 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5038 	 * block sizes.  We need to calculate the offset from buffer start.
5039 	 */
5040 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5041 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5042 		offset = do_div(logical_sb_block, blocksize);
5043 	} else {
5044 		logical_sb_block = sbi->s_sb_block;
5045 	}
5046 
5047 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5048 	if (IS_ERR(bh)) {
5049 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5050 		return PTR_ERR(bh);
5051 	}
5052 	/*
5053 	 * Note: s_es must be initialized as soon as possible because
5054 	 *       some ext4 macro-instructions depend on its value
5055 	 */
5056 	es = (struct ext4_super_block *) (bh->b_data + offset);
5057 	sbi->s_es = es;
5058 	sb->s_magic = le16_to_cpu(es->s_magic);
5059 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5060 		if (!silent)
5061 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5062 		goto out;
5063 	}
5064 
5065 	if (le32_to_cpu(es->s_log_block_size) >
5066 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5067 		ext4_msg(sb, KERN_ERR,
5068 			 "Invalid log block size: %u",
5069 			 le32_to_cpu(es->s_log_block_size));
5070 		goto out;
5071 	}
5072 	if (le32_to_cpu(es->s_log_cluster_size) >
5073 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5074 		ext4_msg(sb, KERN_ERR,
5075 			 "Invalid log cluster size: %u",
5076 			 le32_to_cpu(es->s_log_cluster_size));
5077 		goto out;
5078 	}
5079 
5080 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5081 
5082 	/*
5083 	 * If the default block size is not the same as the real block size,
5084 	 * we need to reload it.
5085 	 */
5086 	if (sb->s_blocksize == blocksize) {
5087 		*lsb = logical_sb_block;
5088 		sbi->s_sbh = bh;
5089 		return 0;
5090 	}
5091 
5092 	/*
5093 	 * bh must be released before kill_bdev(), otherwise
5094 	 * it won't be freed and its page also. kill_bdev()
5095 	 * is called by sb_set_blocksize().
5096 	 */
5097 	brelse(bh);
5098 	/* Validate the filesystem blocksize */
5099 	if (!sb_set_blocksize(sb, blocksize)) {
5100 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5101 				blocksize);
5102 		bh = NULL;
5103 		goto out;
5104 	}
5105 
5106 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5107 	offset = do_div(logical_sb_block, blocksize);
5108 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5109 	if (IS_ERR(bh)) {
5110 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5111 		ret = PTR_ERR(bh);
5112 		bh = NULL;
5113 		goto out;
5114 	}
5115 	es = (struct ext4_super_block *)(bh->b_data + offset);
5116 	sbi->s_es = es;
5117 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5118 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5119 		goto out;
5120 	}
5121 	*lsb = logical_sb_block;
5122 	sbi->s_sbh = bh;
5123 	return 0;
5124 out:
5125 	brelse(bh);
5126 	return ret;
5127 }
5128 
5129 static void ext4_hash_info_init(struct super_block *sb)
5130 {
5131 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5132 	struct ext4_super_block *es = sbi->s_es;
5133 	unsigned int i;
5134 
5135 	for (i = 0; i < 4; i++)
5136 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5137 
5138 	sbi->s_def_hash_version = es->s_def_hash_version;
5139 	if (ext4_has_feature_dir_index(sb)) {
5140 		i = le32_to_cpu(es->s_flags);
5141 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5142 			sbi->s_hash_unsigned = 3;
5143 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5144 #ifdef __CHAR_UNSIGNED__
5145 			if (!sb_rdonly(sb))
5146 				es->s_flags |=
5147 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5148 			sbi->s_hash_unsigned = 3;
5149 #else
5150 			if (!sb_rdonly(sb))
5151 				es->s_flags |=
5152 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5153 #endif
5154 		}
5155 	}
5156 }
5157 
5158 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5159 {
5160 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5161 	struct ext4_super_block *es = sbi->s_es;
5162 	int has_huge_files;
5163 
5164 	has_huge_files = ext4_has_feature_huge_file(sb);
5165 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5166 						      has_huge_files);
5167 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5168 
5169 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5170 	if (ext4_has_feature_64bit(sb)) {
5171 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5172 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5173 		    !is_power_of_2(sbi->s_desc_size)) {
5174 			ext4_msg(sb, KERN_ERR,
5175 			       "unsupported descriptor size %lu",
5176 			       sbi->s_desc_size);
5177 			return -EINVAL;
5178 		}
5179 	} else
5180 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5181 
5182 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5183 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5184 
5185 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5186 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5187 		if (!silent)
5188 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5189 		return -EINVAL;
5190 	}
5191 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5192 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5193 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5194 			 sbi->s_inodes_per_group);
5195 		return -EINVAL;
5196 	}
5197 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5198 					sbi->s_inodes_per_block;
5199 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5200 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5201 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5202 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5203 
5204 	return 0;
5205 }
5206 
5207 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5208 {
5209 	struct ext4_super_block *es = NULL;
5210 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5211 	ext4_fsblk_t logical_sb_block;
5212 	struct inode *root;
5213 	int needs_recovery;
5214 	int err;
5215 	ext4_group_t first_not_zeroed;
5216 	struct ext4_fs_context *ctx = fc->fs_private;
5217 	int silent = fc->sb_flags & SB_SILENT;
5218 
5219 	/* Set defaults for the variables that will be set during parsing */
5220 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5221 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5222 
5223 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5224 	sbi->s_sectors_written_start =
5225 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5226 
5227 	err = ext4_load_super(sb, &logical_sb_block, silent);
5228 	if (err)
5229 		goto out_fail;
5230 
5231 	es = sbi->s_es;
5232 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5233 
5234 	err = ext4_init_metadata_csum(sb, es);
5235 	if (err)
5236 		goto failed_mount;
5237 
5238 	ext4_set_def_opts(sb, es);
5239 
5240 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5241 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5242 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5243 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5244 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5245 
5246 	/*
5247 	 * set default s_li_wait_mult for lazyinit, for the case there is
5248 	 * no mount option specified.
5249 	 */
5250 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5251 
5252 	err = ext4_inode_info_init(sb, es);
5253 	if (err)
5254 		goto failed_mount;
5255 
5256 	err = parse_apply_sb_mount_options(sb, ctx);
5257 	if (err < 0)
5258 		goto failed_mount;
5259 
5260 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5261 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5262 
5263 	err = ext4_check_opt_consistency(fc, sb);
5264 	if (err < 0)
5265 		goto failed_mount;
5266 
5267 	ext4_apply_options(fc, sb);
5268 
5269 	err = ext4_encoding_init(sb, es);
5270 	if (err)
5271 		goto failed_mount;
5272 
5273 	err = ext4_check_journal_data_mode(sb);
5274 	if (err)
5275 		goto failed_mount;
5276 
5277 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5278 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5279 
5280 	/* i_version is always enabled now */
5281 	sb->s_flags |= SB_I_VERSION;
5282 
5283 	err = ext4_check_feature_compatibility(sb, es, silent);
5284 	if (err)
5285 		goto failed_mount;
5286 
5287 	err = ext4_block_group_meta_init(sb, silent);
5288 	if (err)
5289 		goto failed_mount;
5290 
5291 	ext4_hash_info_init(sb);
5292 
5293 	err = ext4_handle_clustersize(sb);
5294 	if (err)
5295 		goto failed_mount;
5296 
5297 	err = ext4_check_geometry(sb, es);
5298 	if (err)
5299 		goto failed_mount;
5300 
5301 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5302 	spin_lock_init(&sbi->s_error_lock);
5303 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5304 
5305 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5306 	if (err)
5307 		goto failed_mount3;
5308 
5309 	err = ext4_es_register_shrinker(sbi);
5310 	if (err)
5311 		goto failed_mount3;
5312 
5313 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5314 	/*
5315 	 * It's hard to get stripe aligned blocks if stripe is not aligned with
5316 	 * cluster, just disable stripe and alert user to simpfy code and avoid
5317 	 * stripe aligned allocation which will rarely successes.
5318 	 */
5319 	if (sbi->s_stripe > 0 && sbi->s_cluster_ratio > 1 &&
5320 	    sbi->s_stripe % sbi->s_cluster_ratio != 0) {
5321 		ext4_msg(sb, KERN_WARNING,
5322 			 "stripe (%lu) is not aligned with cluster size (%u), "
5323 			 "stripe is disabled",
5324 			 sbi->s_stripe, sbi->s_cluster_ratio);
5325 		sbi->s_stripe = 0;
5326 	}
5327 	sbi->s_extent_max_zeroout_kb = 32;
5328 
5329 	/*
5330 	 * set up enough so that it can read an inode
5331 	 */
5332 	sb->s_op = &ext4_sops;
5333 	sb->s_export_op = &ext4_export_ops;
5334 	sb->s_xattr = ext4_xattr_handlers;
5335 #ifdef CONFIG_FS_ENCRYPTION
5336 	sb->s_cop = &ext4_cryptops;
5337 #endif
5338 #ifdef CONFIG_FS_VERITY
5339 	sb->s_vop = &ext4_verityops;
5340 #endif
5341 #ifdef CONFIG_QUOTA
5342 	sb->dq_op = &ext4_quota_operations;
5343 	if (ext4_has_feature_quota(sb))
5344 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5345 	else
5346 		sb->s_qcop = &ext4_qctl_operations;
5347 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5348 #endif
5349 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5350 
5351 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5352 	mutex_init(&sbi->s_orphan_lock);
5353 
5354 	ext4_fast_commit_init(sb);
5355 
5356 	sb->s_root = NULL;
5357 
5358 	needs_recovery = (es->s_last_orphan != 0 ||
5359 			  ext4_has_feature_orphan_present(sb) ||
5360 			  ext4_has_feature_journal_needs_recovery(sb));
5361 
5362 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5363 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5364 		if (err)
5365 			goto failed_mount3a;
5366 	}
5367 
5368 	err = -EINVAL;
5369 	/*
5370 	 * The first inode we look at is the journal inode.  Don't try
5371 	 * root first: it may be modified in the journal!
5372 	 */
5373 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5374 		err = ext4_load_and_init_journal(sb, es, ctx);
5375 		if (err)
5376 			goto failed_mount3a;
5377 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5378 		   ext4_has_feature_journal_needs_recovery(sb)) {
5379 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5380 		       "suppressed and not mounted read-only");
5381 		goto failed_mount3a;
5382 	} else {
5383 		/* Nojournal mode, all journal mount options are illegal */
5384 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5385 			ext4_msg(sb, KERN_ERR, "can't mount with "
5386 				 "journal_async_commit, fs mounted w/o journal");
5387 			goto failed_mount3a;
5388 		}
5389 
5390 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5391 			ext4_msg(sb, KERN_ERR, "can't mount with "
5392 				 "journal_checksum, fs mounted w/o journal");
5393 			goto failed_mount3a;
5394 		}
5395 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5396 			ext4_msg(sb, KERN_ERR, "can't mount with "
5397 				 "commit=%lu, fs mounted w/o journal",
5398 				 sbi->s_commit_interval / HZ);
5399 			goto failed_mount3a;
5400 		}
5401 		if (EXT4_MOUNT_DATA_FLAGS &
5402 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5403 			ext4_msg(sb, KERN_ERR, "can't mount with "
5404 				 "data=, fs mounted w/o journal");
5405 			goto failed_mount3a;
5406 		}
5407 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5408 		clear_opt(sb, JOURNAL_CHECKSUM);
5409 		clear_opt(sb, DATA_FLAGS);
5410 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5411 		sbi->s_journal = NULL;
5412 		needs_recovery = 0;
5413 	}
5414 
5415 	if (!test_opt(sb, NO_MBCACHE)) {
5416 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5417 		if (!sbi->s_ea_block_cache) {
5418 			ext4_msg(sb, KERN_ERR,
5419 				 "Failed to create ea_block_cache");
5420 			err = -EINVAL;
5421 			goto failed_mount_wq;
5422 		}
5423 
5424 		if (ext4_has_feature_ea_inode(sb)) {
5425 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5426 			if (!sbi->s_ea_inode_cache) {
5427 				ext4_msg(sb, KERN_ERR,
5428 					 "Failed to create ea_inode_cache");
5429 				err = -EINVAL;
5430 				goto failed_mount_wq;
5431 			}
5432 		}
5433 	}
5434 
5435 	/*
5436 	 * Get the # of file system overhead blocks from the
5437 	 * superblock if present.
5438 	 */
5439 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5440 	/* ignore the precalculated value if it is ridiculous */
5441 	if (sbi->s_overhead > ext4_blocks_count(es))
5442 		sbi->s_overhead = 0;
5443 	/*
5444 	 * If the bigalloc feature is not enabled recalculating the
5445 	 * overhead doesn't take long, so we might as well just redo
5446 	 * it to make sure we are using the correct value.
5447 	 */
5448 	if (!ext4_has_feature_bigalloc(sb))
5449 		sbi->s_overhead = 0;
5450 	if (sbi->s_overhead == 0) {
5451 		err = ext4_calculate_overhead(sb);
5452 		if (err)
5453 			goto failed_mount_wq;
5454 	}
5455 
5456 	/*
5457 	 * The maximum number of concurrent works can be high and
5458 	 * concurrency isn't really necessary.  Limit it to 1.
5459 	 */
5460 	EXT4_SB(sb)->rsv_conversion_wq =
5461 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5462 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5463 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5464 		err = -ENOMEM;
5465 		goto failed_mount4;
5466 	}
5467 
5468 	/*
5469 	 * The jbd2_journal_load will have done any necessary log recovery,
5470 	 * so we can safely mount the rest of the filesystem now.
5471 	 */
5472 
5473 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5474 	if (IS_ERR(root)) {
5475 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5476 		err = PTR_ERR(root);
5477 		root = NULL;
5478 		goto failed_mount4;
5479 	}
5480 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5481 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5482 		iput(root);
5483 		err = -EFSCORRUPTED;
5484 		goto failed_mount4;
5485 	}
5486 
5487 	sb->s_root = d_make_root(root);
5488 	if (!sb->s_root) {
5489 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5490 		err = -ENOMEM;
5491 		goto failed_mount4;
5492 	}
5493 
5494 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5495 	if (err == -EROFS) {
5496 		sb->s_flags |= SB_RDONLY;
5497 	} else if (err)
5498 		goto failed_mount4a;
5499 
5500 	ext4_set_resv_clusters(sb);
5501 
5502 	if (test_opt(sb, BLOCK_VALIDITY)) {
5503 		err = ext4_setup_system_zone(sb);
5504 		if (err) {
5505 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5506 				 "zone (%d)", err);
5507 			goto failed_mount4a;
5508 		}
5509 	}
5510 	ext4_fc_replay_cleanup(sb);
5511 
5512 	ext4_ext_init(sb);
5513 
5514 	/*
5515 	 * Enable optimize_scan if number of groups is > threshold. This can be
5516 	 * turned off by passing "mb_optimize_scan=0". This can also be
5517 	 * turned on forcefully by passing "mb_optimize_scan=1".
5518 	 */
5519 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5520 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5521 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5522 		else
5523 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5524 	}
5525 
5526 	err = ext4_mb_init(sb);
5527 	if (err) {
5528 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5529 			 err);
5530 		goto failed_mount5;
5531 	}
5532 
5533 	/*
5534 	 * We can only set up the journal commit callback once
5535 	 * mballoc is initialized
5536 	 */
5537 	if (sbi->s_journal)
5538 		sbi->s_journal->j_commit_callback =
5539 			ext4_journal_commit_callback;
5540 
5541 	err = ext4_percpu_param_init(sbi);
5542 	if (err)
5543 		goto failed_mount6;
5544 
5545 	if (ext4_has_feature_flex_bg(sb))
5546 		if (!ext4_fill_flex_info(sb)) {
5547 			ext4_msg(sb, KERN_ERR,
5548 			       "unable to initialize "
5549 			       "flex_bg meta info!");
5550 			err = -ENOMEM;
5551 			goto failed_mount6;
5552 		}
5553 
5554 	err = ext4_register_li_request(sb, first_not_zeroed);
5555 	if (err)
5556 		goto failed_mount6;
5557 
5558 	err = ext4_register_sysfs(sb);
5559 	if (err)
5560 		goto failed_mount7;
5561 
5562 	err = ext4_init_orphan_info(sb);
5563 	if (err)
5564 		goto failed_mount8;
5565 #ifdef CONFIG_QUOTA
5566 	/* Enable quota usage during mount. */
5567 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5568 		err = ext4_enable_quotas(sb);
5569 		if (err)
5570 			goto failed_mount9;
5571 	}
5572 #endif  /* CONFIG_QUOTA */
5573 
5574 	/*
5575 	 * Save the original bdev mapping's wb_err value which could be
5576 	 * used to detect the metadata async write error.
5577 	 */
5578 	spin_lock_init(&sbi->s_bdev_wb_lock);
5579 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5580 				 &sbi->s_bdev_wb_err);
5581 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5582 	ext4_orphan_cleanup(sb, es);
5583 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5584 	/*
5585 	 * Update the checksum after updating free space/inode counters and
5586 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5587 	 * checksum in the buffer cache until it is written out and
5588 	 * e2fsprogs programs trying to open a file system immediately
5589 	 * after it is mounted can fail.
5590 	 */
5591 	ext4_superblock_csum_set(sb);
5592 	if (needs_recovery) {
5593 		ext4_msg(sb, KERN_INFO, "recovery complete");
5594 		err = ext4_mark_recovery_complete(sb, es);
5595 		if (err)
5596 			goto failed_mount10;
5597 	}
5598 
5599 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5600 		ext4_msg(sb, KERN_WARNING,
5601 			 "mounting with \"discard\" option, but the device does not support discard");
5602 
5603 	if (es->s_error_count)
5604 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5605 
5606 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5607 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5608 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5609 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5610 	atomic_set(&sbi->s_warning_count, 0);
5611 	atomic_set(&sbi->s_msg_count, 0);
5612 
5613 	return 0;
5614 
5615 failed_mount10:
5616 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5617 failed_mount9: __maybe_unused
5618 	ext4_release_orphan_info(sb);
5619 failed_mount8:
5620 	ext4_unregister_sysfs(sb);
5621 	kobject_put(&sbi->s_kobj);
5622 failed_mount7:
5623 	ext4_unregister_li_request(sb);
5624 failed_mount6:
5625 	ext4_mb_release(sb);
5626 	ext4_flex_groups_free(sbi);
5627 	ext4_percpu_param_destroy(sbi);
5628 failed_mount5:
5629 	ext4_ext_release(sb);
5630 	ext4_release_system_zone(sb);
5631 failed_mount4a:
5632 	dput(sb->s_root);
5633 	sb->s_root = NULL;
5634 failed_mount4:
5635 	ext4_msg(sb, KERN_ERR, "mount failed");
5636 	if (EXT4_SB(sb)->rsv_conversion_wq)
5637 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5638 failed_mount_wq:
5639 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5640 	sbi->s_ea_inode_cache = NULL;
5641 
5642 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5643 	sbi->s_ea_block_cache = NULL;
5644 
5645 	if (sbi->s_journal) {
5646 		/* flush s_sb_upd_work before journal destroy. */
5647 		flush_work(&sbi->s_sb_upd_work);
5648 		jbd2_journal_destroy(sbi->s_journal);
5649 		sbi->s_journal = NULL;
5650 	}
5651 failed_mount3a:
5652 	ext4_es_unregister_shrinker(sbi);
5653 failed_mount3:
5654 	/* flush s_sb_upd_work before sbi destroy */
5655 	flush_work(&sbi->s_sb_upd_work);
5656 	del_timer_sync(&sbi->s_err_report);
5657 	ext4_stop_mmpd(sbi);
5658 	ext4_group_desc_free(sbi);
5659 failed_mount:
5660 	if (sbi->s_chksum_driver)
5661 		crypto_free_shash(sbi->s_chksum_driver);
5662 
5663 #if IS_ENABLED(CONFIG_UNICODE)
5664 	utf8_unload(sb->s_encoding);
5665 #endif
5666 
5667 #ifdef CONFIG_QUOTA
5668 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5669 		kfree(get_qf_name(sb, sbi, i));
5670 #endif
5671 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5672 	brelse(sbi->s_sbh);
5673 	if (sbi->s_journal_bdev) {
5674 		invalidate_bdev(sbi->s_journal_bdev);
5675 		blkdev_put(sbi->s_journal_bdev, sb);
5676 	}
5677 out_fail:
5678 	invalidate_bdev(sb->s_bdev);
5679 	sb->s_fs_info = NULL;
5680 	return err;
5681 }
5682 
5683 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5684 {
5685 	struct ext4_fs_context *ctx = fc->fs_private;
5686 	struct ext4_sb_info *sbi;
5687 	const char *descr;
5688 	int ret;
5689 
5690 	sbi = ext4_alloc_sbi(sb);
5691 	if (!sbi)
5692 		return -ENOMEM;
5693 
5694 	fc->s_fs_info = sbi;
5695 
5696 	/* Cleanup superblock name */
5697 	strreplace(sb->s_id, '/', '!');
5698 
5699 	sbi->s_sb_block = 1;	/* Default super block location */
5700 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5701 		sbi->s_sb_block = ctx->s_sb_block;
5702 
5703 	ret = __ext4_fill_super(fc, sb);
5704 	if (ret < 0)
5705 		goto free_sbi;
5706 
5707 	if (sbi->s_journal) {
5708 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5709 			descr = " journalled data mode";
5710 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5711 			descr = " ordered data mode";
5712 		else
5713 			descr = " writeback data mode";
5714 	} else
5715 		descr = "out journal";
5716 
5717 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5718 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5719 			 "Quota mode: %s.", &sb->s_uuid,
5720 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5721 			 ext4_quota_mode(sb));
5722 
5723 	/* Update the s_overhead_clusters if necessary */
5724 	ext4_update_overhead(sb, false);
5725 	return 0;
5726 
5727 free_sbi:
5728 	ext4_free_sbi(sbi);
5729 	fc->s_fs_info = NULL;
5730 	return ret;
5731 }
5732 
5733 static int ext4_get_tree(struct fs_context *fc)
5734 {
5735 	return get_tree_bdev(fc, ext4_fill_super);
5736 }
5737 
5738 /*
5739  * Setup any per-fs journal parameters now.  We'll do this both on
5740  * initial mount, once the journal has been initialised but before we've
5741  * done any recovery; and again on any subsequent remount.
5742  */
5743 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5744 {
5745 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5746 
5747 	journal->j_commit_interval = sbi->s_commit_interval;
5748 	journal->j_min_batch_time = sbi->s_min_batch_time;
5749 	journal->j_max_batch_time = sbi->s_max_batch_time;
5750 	ext4_fc_init(sb, journal);
5751 
5752 	write_lock(&journal->j_state_lock);
5753 	if (test_opt(sb, BARRIER))
5754 		journal->j_flags |= JBD2_BARRIER;
5755 	else
5756 		journal->j_flags &= ~JBD2_BARRIER;
5757 	if (test_opt(sb, DATA_ERR_ABORT))
5758 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5759 	else
5760 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5761 	/*
5762 	 * Always enable journal cycle record option, letting the journal
5763 	 * records log transactions continuously between each mount.
5764 	 */
5765 	journal->j_flags |= JBD2_CYCLE_RECORD;
5766 	write_unlock(&journal->j_state_lock);
5767 }
5768 
5769 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5770 					     unsigned int journal_inum)
5771 {
5772 	struct inode *journal_inode;
5773 
5774 	/*
5775 	 * Test for the existence of a valid inode on disk.  Bad things
5776 	 * happen if we iget() an unused inode, as the subsequent iput()
5777 	 * will try to delete it.
5778 	 */
5779 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5780 	if (IS_ERR(journal_inode)) {
5781 		ext4_msg(sb, KERN_ERR, "no journal found");
5782 		return ERR_CAST(journal_inode);
5783 	}
5784 	if (!journal_inode->i_nlink) {
5785 		make_bad_inode(journal_inode);
5786 		iput(journal_inode);
5787 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5788 		return ERR_PTR(-EFSCORRUPTED);
5789 	}
5790 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5791 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5792 		iput(journal_inode);
5793 		return ERR_PTR(-EFSCORRUPTED);
5794 	}
5795 
5796 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5797 		  journal_inode, journal_inode->i_size);
5798 	return journal_inode;
5799 }
5800 
5801 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5802 {
5803 	struct ext4_map_blocks map;
5804 	int ret;
5805 
5806 	if (journal->j_inode == NULL)
5807 		return 0;
5808 
5809 	map.m_lblk = *block;
5810 	map.m_len = 1;
5811 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5812 	if (ret <= 0) {
5813 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5814 			 "journal bmap failed: block %llu ret %d\n",
5815 			 *block, ret);
5816 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5817 		return ret;
5818 	}
5819 	*block = map.m_pblk;
5820 	return 0;
5821 }
5822 
5823 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5824 					  unsigned int journal_inum)
5825 {
5826 	struct inode *journal_inode;
5827 	journal_t *journal;
5828 
5829 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5830 	if (IS_ERR(journal_inode))
5831 		return ERR_CAST(journal_inode);
5832 
5833 	journal = jbd2_journal_init_inode(journal_inode);
5834 	if (IS_ERR(journal)) {
5835 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5836 		iput(journal_inode);
5837 		return ERR_CAST(journal);
5838 	}
5839 	journal->j_private = sb;
5840 	journal->j_bmap = ext4_journal_bmap;
5841 	ext4_init_journal_params(sb, journal);
5842 	return journal;
5843 }
5844 
5845 static struct block_device *ext4_get_journal_blkdev(struct super_block *sb,
5846 					dev_t j_dev, ext4_fsblk_t *j_start,
5847 					ext4_fsblk_t *j_len)
5848 {
5849 	struct buffer_head *bh;
5850 	struct block_device *bdev;
5851 	int hblock, blocksize;
5852 	ext4_fsblk_t sb_block;
5853 	unsigned long offset;
5854 	struct ext4_super_block *es;
5855 	int errno;
5856 
5857 	/* see get_tree_bdev why this is needed and safe */
5858 	up_write(&sb->s_umount);
5859 	bdev = blkdev_get_by_dev(j_dev, BLK_OPEN_READ | BLK_OPEN_WRITE, sb,
5860 				 &fs_holder_ops);
5861 	down_write(&sb->s_umount);
5862 	if (IS_ERR(bdev)) {
5863 		ext4_msg(sb, KERN_ERR,
5864 			 "failed to open journal device unknown-block(%u,%u) %ld",
5865 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev));
5866 		return ERR_CAST(bdev);
5867 	}
5868 
5869 	blocksize = sb->s_blocksize;
5870 	hblock = bdev_logical_block_size(bdev);
5871 	if (blocksize < hblock) {
5872 		ext4_msg(sb, KERN_ERR,
5873 			"blocksize too small for journal device");
5874 		errno = -EINVAL;
5875 		goto out_bdev;
5876 	}
5877 
5878 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5879 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5880 	set_blocksize(bdev, blocksize);
5881 	bh = __bread(bdev, sb_block, blocksize);
5882 	if (!bh) {
5883 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5884 		       "external journal");
5885 		errno = -EINVAL;
5886 		goto out_bdev;
5887 	}
5888 
5889 	es = (struct ext4_super_block *) (bh->b_data + offset);
5890 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5891 	    !(le32_to_cpu(es->s_feature_incompat) &
5892 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5893 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
5894 		errno = -EFSCORRUPTED;
5895 		goto out_bh;
5896 	}
5897 
5898 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5899 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5900 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5901 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
5902 		errno = -EFSCORRUPTED;
5903 		goto out_bh;
5904 	}
5905 
5906 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5907 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5908 		errno = -EFSCORRUPTED;
5909 		goto out_bh;
5910 	}
5911 
5912 	*j_start = sb_block + 1;
5913 	*j_len = ext4_blocks_count(es);
5914 	brelse(bh);
5915 	return bdev;
5916 
5917 out_bh:
5918 	brelse(bh);
5919 out_bdev:
5920 	blkdev_put(bdev, sb);
5921 	return ERR_PTR(errno);
5922 }
5923 
5924 static journal_t *ext4_open_dev_journal(struct super_block *sb,
5925 					dev_t j_dev)
5926 {
5927 	journal_t *journal;
5928 	ext4_fsblk_t j_start;
5929 	ext4_fsblk_t j_len;
5930 	struct block_device *journal_bdev;
5931 	int errno = 0;
5932 
5933 	journal_bdev = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
5934 	if (IS_ERR(journal_bdev))
5935 		return ERR_CAST(journal_bdev);
5936 
5937 	journal = jbd2_journal_init_dev(journal_bdev, sb->s_bdev, j_start,
5938 					j_len, sb->s_blocksize);
5939 	if (IS_ERR(journal)) {
5940 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5941 		errno = PTR_ERR(journal);
5942 		goto out_bdev;
5943 	}
5944 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5945 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5946 					"user (unsupported) - %d",
5947 			be32_to_cpu(journal->j_superblock->s_nr_users));
5948 		errno = -EINVAL;
5949 		goto out_journal;
5950 	}
5951 	journal->j_private = sb;
5952 	EXT4_SB(sb)->s_journal_bdev = journal_bdev;
5953 	ext4_init_journal_params(sb, journal);
5954 	return journal;
5955 
5956 out_journal:
5957 	jbd2_journal_destroy(journal);
5958 out_bdev:
5959 	blkdev_put(journal_bdev, sb);
5960 	return ERR_PTR(errno);
5961 }
5962 
5963 static int ext4_load_journal(struct super_block *sb,
5964 			     struct ext4_super_block *es,
5965 			     unsigned long journal_devnum)
5966 {
5967 	journal_t *journal;
5968 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5969 	dev_t journal_dev;
5970 	int err = 0;
5971 	int really_read_only;
5972 	int journal_dev_ro;
5973 
5974 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5975 		return -EFSCORRUPTED;
5976 
5977 	if (journal_devnum &&
5978 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5979 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5980 			"numbers have changed");
5981 		journal_dev = new_decode_dev(journal_devnum);
5982 	} else
5983 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5984 
5985 	if (journal_inum && journal_dev) {
5986 		ext4_msg(sb, KERN_ERR,
5987 			 "filesystem has both journal inode and journal device!");
5988 		return -EINVAL;
5989 	}
5990 
5991 	if (journal_inum) {
5992 		journal = ext4_open_inode_journal(sb, journal_inum);
5993 		if (IS_ERR(journal))
5994 			return PTR_ERR(journal);
5995 	} else {
5996 		journal = ext4_open_dev_journal(sb, journal_dev);
5997 		if (IS_ERR(journal))
5998 			return PTR_ERR(journal);
5999 	}
6000 
6001 	journal_dev_ro = bdev_read_only(journal->j_dev);
6002 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
6003 
6004 	if (journal_dev_ro && !sb_rdonly(sb)) {
6005 		ext4_msg(sb, KERN_ERR,
6006 			 "journal device read-only, try mounting with '-o ro'");
6007 		err = -EROFS;
6008 		goto err_out;
6009 	}
6010 
6011 	/*
6012 	 * Are we loading a blank journal or performing recovery after a
6013 	 * crash?  For recovery, we need to check in advance whether we
6014 	 * can get read-write access to the device.
6015 	 */
6016 	if (ext4_has_feature_journal_needs_recovery(sb)) {
6017 		if (sb_rdonly(sb)) {
6018 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
6019 					"required on readonly filesystem");
6020 			if (really_read_only) {
6021 				ext4_msg(sb, KERN_ERR, "write access "
6022 					"unavailable, cannot proceed "
6023 					"(try mounting with noload)");
6024 				err = -EROFS;
6025 				goto err_out;
6026 			}
6027 			ext4_msg(sb, KERN_INFO, "write access will "
6028 			       "be enabled during recovery");
6029 		}
6030 	}
6031 
6032 	if (!(journal->j_flags & JBD2_BARRIER))
6033 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6034 
6035 	if (!ext4_has_feature_journal_needs_recovery(sb))
6036 		err = jbd2_journal_wipe(journal, !really_read_only);
6037 	if (!err) {
6038 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6039 		__le16 orig_state;
6040 		bool changed = false;
6041 
6042 		if (save)
6043 			memcpy(save, ((char *) es) +
6044 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6045 		err = jbd2_journal_load(journal);
6046 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6047 				   save, EXT4_S_ERR_LEN)) {
6048 			memcpy(((char *) es) + EXT4_S_ERR_START,
6049 			       save, EXT4_S_ERR_LEN);
6050 			changed = true;
6051 		}
6052 		kfree(save);
6053 		orig_state = es->s_state;
6054 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6055 					   EXT4_ERROR_FS);
6056 		if (orig_state != es->s_state)
6057 			changed = true;
6058 		/* Write out restored error information to the superblock */
6059 		if (changed && !really_read_only) {
6060 			int err2;
6061 			err2 = ext4_commit_super(sb);
6062 			err = err ? : err2;
6063 		}
6064 	}
6065 
6066 	if (err) {
6067 		ext4_msg(sb, KERN_ERR, "error loading journal");
6068 		goto err_out;
6069 	}
6070 
6071 	EXT4_SB(sb)->s_journal = journal;
6072 	err = ext4_clear_journal_err(sb, es);
6073 	if (err) {
6074 		EXT4_SB(sb)->s_journal = NULL;
6075 		jbd2_journal_destroy(journal);
6076 		return err;
6077 	}
6078 
6079 	if (!really_read_only && journal_devnum &&
6080 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6081 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6082 		ext4_commit_super(sb);
6083 	}
6084 	if (!really_read_only && journal_inum &&
6085 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6086 		es->s_journal_inum = cpu_to_le32(journal_inum);
6087 		ext4_commit_super(sb);
6088 	}
6089 
6090 	return 0;
6091 
6092 err_out:
6093 	jbd2_journal_destroy(journal);
6094 	return err;
6095 }
6096 
6097 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6098 static void ext4_update_super(struct super_block *sb)
6099 {
6100 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6101 	struct ext4_super_block *es = sbi->s_es;
6102 	struct buffer_head *sbh = sbi->s_sbh;
6103 
6104 	lock_buffer(sbh);
6105 	/*
6106 	 * If the file system is mounted read-only, don't update the
6107 	 * superblock write time.  This avoids updating the superblock
6108 	 * write time when we are mounting the root file system
6109 	 * read/only but we need to replay the journal; at that point,
6110 	 * for people who are east of GMT and who make their clock
6111 	 * tick in localtime for Windows bug-for-bug compatibility,
6112 	 * the clock is set in the future, and this will cause e2fsck
6113 	 * to complain and force a full file system check.
6114 	 */
6115 	if (!sb_rdonly(sb))
6116 		ext4_update_tstamp(es, s_wtime);
6117 	es->s_kbytes_written =
6118 		cpu_to_le64(sbi->s_kbytes_written +
6119 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6120 		      sbi->s_sectors_written_start) >> 1));
6121 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6122 		ext4_free_blocks_count_set(es,
6123 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6124 				&sbi->s_freeclusters_counter)));
6125 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6126 		es->s_free_inodes_count =
6127 			cpu_to_le32(percpu_counter_sum_positive(
6128 				&sbi->s_freeinodes_counter));
6129 	/* Copy error information to the on-disk superblock */
6130 	spin_lock(&sbi->s_error_lock);
6131 	if (sbi->s_add_error_count > 0) {
6132 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6133 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6134 			__ext4_update_tstamp(&es->s_first_error_time,
6135 					     &es->s_first_error_time_hi,
6136 					     sbi->s_first_error_time);
6137 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6138 				sizeof(es->s_first_error_func));
6139 			es->s_first_error_line =
6140 				cpu_to_le32(sbi->s_first_error_line);
6141 			es->s_first_error_ino =
6142 				cpu_to_le32(sbi->s_first_error_ino);
6143 			es->s_first_error_block =
6144 				cpu_to_le64(sbi->s_first_error_block);
6145 			es->s_first_error_errcode =
6146 				ext4_errno_to_code(sbi->s_first_error_code);
6147 		}
6148 		__ext4_update_tstamp(&es->s_last_error_time,
6149 				     &es->s_last_error_time_hi,
6150 				     sbi->s_last_error_time);
6151 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6152 			sizeof(es->s_last_error_func));
6153 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6154 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6155 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6156 		es->s_last_error_errcode =
6157 				ext4_errno_to_code(sbi->s_last_error_code);
6158 		/*
6159 		 * Start the daily error reporting function if it hasn't been
6160 		 * started already
6161 		 */
6162 		if (!es->s_error_count)
6163 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6164 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6165 		sbi->s_add_error_count = 0;
6166 	}
6167 	spin_unlock(&sbi->s_error_lock);
6168 
6169 	ext4_superblock_csum_set(sb);
6170 	unlock_buffer(sbh);
6171 }
6172 
6173 static int ext4_commit_super(struct super_block *sb)
6174 {
6175 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6176 
6177 	if (!sbh)
6178 		return -EINVAL;
6179 	if (block_device_ejected(sb))
6180 		return -ENODEV;
6181 
6182 	ext4_update_super(sb);
6183 
6184 	lock_buffer(sbh);
6185 	/* Buffer got discarded which means block device got invalidated */
6186 	if (!buffer_mapped(sbh)) {
6187 		unlock_buffer(sbh);
6188 		return -EIO;
6189 	}
6190 
6191 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6192 		/*
6193 		 * Oh, dear.  A previous attempt to write the
6194 		 * superblock failed.  This could happen because the
6195 		 * USB device was yanked out.  Or it could happen to
6196 		 * be a transient write error and maybe the block will
6197 		 * be remapped.  Nothing we can do but to retry the
6198 		 * write and hope for the best.
6199 		 */
6200 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6201 		       "superblock detected");
6202 		clear_buffer_write_io_error(sbh);
6203 		set_buffer_uptodate(sbh);
6204 	}
6205 	get_bh(sbh);
6206 	/* Clear potential dirty bit if it was journalled update */
6207 	clear_buffer_dirty(sbh);
6208 	sbh->b_end_io = end_buffer_write_sync;
6209 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6210 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6211 	wait_on_buffer(sbh);
6212 	if (buffer_write_io_error(sbh)) {
6213 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6214 		       "superblock");
6215 		clear_buffer_write_io_error(sbh);
6216 		set_buffer_uptodate(sbh);
6217 		return -EIO;
6218 	}
6219 	return 0;
6220 }
6221 
6222 /*
6223  * Have we just finished recovery?  If so, and if we are mounting (or
6224  * remounting) the filesystem readonly, then we will end up with a
6225  * consistent fs on disk.  Record that fact.
6226  */
6227 static int ext4_mark_recovery_complete(struct super_block *sb,
6228 				       struct ext4_super_block *es)
6229 {
6230 	int err;
6231 	journal_t *journal = EXT4_SB(sb)->s_journal;
6232 
6233 	if (!ext4_has_feature_journal(sb)) {
6234 		if (journal != NULL) {
6235 			ext4_error(sb, "Journal got removed while the fs was "
6236 				   "mounted!");
6237 			return -EFSCORRUPTED;
6238 		}
6239 		return 0;
6240 	}
6241 	jbd2_journal_lock_updates(journal);
6242 	err = jbd2_journal_flush(journal, 0);
6243 	if (err < 0)
6244 		goto out;
6245 
6246 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6247 	    ext4_has_feature_orphan_present(sb))) {
6248 		if (!ext4_orphan_file_empty(sb)) {
6249 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6250 			err = -EFSCORRUPTED;
6251 			goto out;
6252 		}
6253 		ext4_clear_feature_journal_needs_recovery(sb);
6254 		ext4_clear_feature_orphan_present(sb);
6255 		ext4_commit_super(sb);
6256 	}
6257 out:
6258 	jbd2_journal_unlock_updates(journal);
6259 	return err;
6260 }
6261 
6262 /*
6263  * If we are mounting (or read-write remounting) a filesystem whose journal
6264  * has recorded an error from a previous lifetime, move that error to the
6265  * main filesystem now.
6266  */
6267 static int ext4_clear_journal_err(struct super_block *sb,
6268 				   struct ext4_super_block *es)
6269 {
6270 	journal_t *journal;
6271 	int j_errno;
6272 	const char *errstr;
6273 
6274 	if (!ext4_has_feature_journal(sb)) {
6275 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6276 		return -EFSCORRUPTED;
6277 	}
6278 
6279 	journal = EXT4_SB(sb)->s_journal;
6280 
6281 	/*
6282 	 * Now check for any error status which may have been recorded in the
6283 	 * journal by a prior ext4_error() or ext4_abort()
6284 	 */
6285 
6286 	j_errno = jbd2_journal_errno(journal);
6287 	if (j_errno) {
6288 		char nbuf[16];
6289 
6290 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6291 		ext4_warning(sb, "Filesystem error recorded "
6292 			     "from previous mount: %s", errstr);
6293 
6294 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6295 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6296 		j_errno = ext4_commit_super(sb);
6297 		if (j_errno)
6298 			return j_errno;
6299 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6300 
6301 		jbd2_journal_clear_err(journal);
6302 		jbd2_journal_update_sb_errno(journal);
6303 	}
6304 	return 0;
6305 }
6306 
6307 /*
6308  * Force the running and committing transactions to commit,
6309  * and wait on the commit.
6310  */
6311 int ext4_force_commit(struct super_block *sb)
6312 {
6313 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6314 }
6315 
6316 static int ext4_sync_fs(struct super_block *sb, int wait)
6317 {
6318 	int ret = 0;
6319 	tid_t target;
6320 	bool needs_barrier = false;
6321 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6322 
6323 	if (unlikely(ext4_forced_shutdown(sb)))
6324 		return 0;
6325 
6326 	trace_ext4_sync_fs(sb, wait);
6327 	flush_workqueue(sbi->rsv_conversion_wq);
6328 	/*
6329 	 * Writeback quota in non-journalled quota case - journalled quota has
6330 	 * no dirty dquots
6331 	 */
6332 	dquot_writeback_dquots(sb, -1);
6333 	/*
6334 	 * Data writeback is possible w/o journal transaction, so barrier must
6335 	 * being sent at the end of the function. But we can skip it if
6336 	 * transaction_commit will do it for us.
6337 	 */
6338 	if (sbi->s_journal) {
6339 		target = jbd2_get_latest_transaction(sbi->s_journal);
6340 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6341 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6342 			needs_barrier = true;
6343 
6344 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6345 			if (wait)
6346 				ret = jbd2_log_wait_commit(sbi->s_journal,
6347 							   target);
6348 		}
6349 	} else if (wait && test_opt(sb, BARRIER))
6350 		needs_barrier = true;
6351 	if (needs_barrier) {
6352 		int err;
6353 		err = blkdev_issue_flush(sb->s_bdev);
6354 		if (!ret)
6355 			ret = err;
6356 	}
6357 
6358 	return ret;
6359 }
6360 
6361 /*
6362  * LVM calls this function before a (read-only) snapshot is created.  This
6363  * gives us a chance to flush the journal completely and mark the fs clean.
6364  *
6365  * Note that only this function cannot bring a filesystem to be in a clean
6366  * state independently. It relies on upper layer to stop all data & metadata
6367  * modifications.
6368  */
6369 static int ext4_freeze(struct super_block *sb)
6370 {
6371 	int error = 0;
6372 	journal_t *journal = EXT4_SB(sb)->s_journal;
6373 
6374 	if (journal) {
6375 		/* Now we set up the journal barrier. */
6376 		jbd2_journal_lock_updates(journal);
6377 
6378 		/*
6379 		 * Don't clear the needs_recovery flag if we failed to
6380 		 * flush the journal.
6381 		 */
6382 		error = jbd2_journal_flush(journal, 0);
6383 		if (error < 0)
6384 			goto out;
6385 
6386 		/* Journal blocked and flushed, clear needs_recovery flag. */
6387 		ext4_clear_feature_journal_needs_recovery(sb);
6388 		if (ext4_orphan_file_empty(sb))
6389 			ext4_clear_feature_orphan_present(sb);
6390 	}
6391 
6392 	error = ext4_commit_super(sb);
6393 out:
6394 	if (journal)
6395 		/* we rely on upper layer to stop further updates */
6396 		jbd2_journal_unlock_updates(journal);
6397 	return error;
6398 }
6399 
6400 /*
6401  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6402  * flag here, even though the filesystem is not technically dirty yet.
6403  */
6404 static int ext4_unfreeze(struct super_block *sb)
6405 {
6406 	if (ext4_forced_shutdown(sb))
6407 		return 0;
6408 
6409 	if (EXT4_SB(sb)->s_journal) {
6410 		/* Reset the needs_recovery flag before the fs is unlocked. */
6411 		ext4_set_feature_journal_needs_recovery(sb);
6412 		if (ext4_has_feature_orphan_file(sb))
6413 			ext4_set_feature_orphan_present(sb);
6414 	}
6415 
6416 	ext4_commit_super(sb);
6417 	return 0;
6418 }
6419 
6420 /*
6421  * Structure to save mount options for ext4_remount's benefit
6422  */
6423 struct ext4_mount_options {
6424 	unsigned long s_mount_opt;
6425 	unsigned long s_mount_opt2;
6426 	kuid_t s_resuid;
6427 	kgid_t s_resgid;
6428 	unsigned long s_commit_interval;
6429 	u32 s_min_batch_time, s_max_batch_time;
6430 #ifdef CONFIG_QUOTA
6431 	int s_jquota_fmt;
6432 	char *s_qf_names[EXT4_MAXQUOTAS];
6433 #endif
6434 };
6435 
6436 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6437 {
6438 	struct ext4_fs_context *ctx = fc->fs_private;
6439 	struct ext4_super_block *es;
6440 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6441 	unsigned long old_sb_flags;
6442 	struct ext4_mount_options old_opts;
6443 	ext4_group_t g;
6444 	int err = 0;
6445 #ifdef CONFIG_QUOTA
6446 	int enable_quota = 0;
6447 	int i, j;
6448 	char *to_free[EXT4_MAXQUOTAS];
6449 #endif
6450 
6451 
6452 	/* Store the original options */
6453 	old_sb_flags = sb->s_flags;
6454 	old_opts.s_mount_opt = sbi->s_mount_opt;
6455 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6456 	old_opts.s_resuid = sbi->s_resuid;
6457 	old_opts.s_resgid = sbi->s_resgid;
6458 	old_opts.s_commit_interval = sbi->s_commit_interval;
6459 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6460 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6461 #ifdef CONFIG_QUOTA
6462 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6463 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6464 		if (sbi->s_qf_names[i]) {
6465 			char *qf_name = get_qf_name(sb, sbi, i);
6466 
6467 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6468 			if (!old_opts.s_qf_names[i]) {
6469 				for (j = 0; j < i; j++)
6470 					kfree(old_opts.s_qf_names[j]);
6471 				return -ENOMEM;
6472 			}
6473 		} else
6474 			old_opts.s_qf_names[i] = NULL;
6475 #endif
6476 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6477 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6478 			ctx->journal_ioprio =
6479 				sbi->s_journal->j_task->io_context->ioprio;
6480 		else
6481 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6482 
6483 	}
6484 
6485 	ext4_apply_options(fc, sb);
6486 
6487 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6488 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6489 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6490 			 "during remount not supported; ignoring");
6491 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6492 	}
6493 
6494 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6495 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6496 			ext4_msg(sb, KERN_ERR, "can't mount with "
6497 				 "both data=journal and delalloc");
6498 			err = -EINVAL;
6499 			goto restore_opts;
6500 		}
6501 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6502 			ext4_msg(sb, KERN_ERR, "can't mount with "
6503 				 "both data=journal and dioread_nolock");
6504 			err = -EINVAL;
6505 			goto restore_opts;
6506 		}
6507 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6508 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6509 			ext4_msg(sb, KERN_ERR, "can't mount with "
6510 				"journal_async_commit in data=ordered mode");
6511 			err = -EINVAL;
6512 			goto restore_opts;
6513 		}
6514 	}
6515 
6516 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6517 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6518 		err = -EINVAL;
6519 		goto restore_opts;
6520 	}
6521 
6522 	if (test_opt2(sb, ABORT))
6523 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6524 
6525 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6526 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6527 
6528 	es = sbi->s_es;
6529 
6530 	if (sbi->s_journal) {
6531 		ext4_init_journal_params(sb, sbi->s_journal);
6532 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6533 	}
6534 
6535 	/* Flush outstanding errors before changing fs state */
6536 	flush_work(&sbi->s_sb_upd_work);
6537 
6538 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6539 		if (ext4_forced_shutdown(sb)) {
6540 			err = -EROFS;
6541 			goto restore_opts;
6542 		}
6543 
6544 		if (fc->sb_flags & SB_RDONLY) {
6545 			err = sync_filesystem(sb);
6546 			if (err < 0)
6547 				goto restore_opts;
6548 			err = dquot_suspend(sb, -1);
6549 			if (err < 0)
6550 				goto restore_opts;
6551 
6552 			/*
6553 			 * First of all, the unconditional stuff we have to do
6554 			 * to disable replay of the journal when we next remount
6555 			 */
6556 			sb->s_flags |= SB_RDONLY;
6557 
6558 			/*
6559 			 * OK, test if we are remounting a valid rw partition
6560 			 * readonly, and if so set the rdonly flag and then
6561 			 * mark the partition as valid again.
6562 			 */
6563 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6564 			    (sbi->s_mount_state & EXT4_VALID_FS))
6565 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6566 
6567 			if (sbi->s_journal) {
6568 				/*
6569 				 * We let remount-ro finish even if marking fs
6570 				 * as clean failed...
6571 				 */
6572 				ext4_mark_recovery_complete(sb, es);
6573 			}
6574 		} else {
6575 			/* Make sure we can mount this feature set readwrite */
6576 			if (ext4_has_feature_readonly(sb) ||
6577 			    !ext4_feature_set_ok(sb, 0)) {
6578 				err = -EROFS;
6579 				goto restore_opts;
6580 			}
6581 			/*
6582 			 * Make sure the group descriptor checksums
6583 			 * are sane.  If they aren't, refuse to remount r/w.
6584 			 */
6585 			for (g = 0; g < sbi->s_groups_count; g++) {
6586 				struct ext4_group_desc *gdp =
6587 					ext4_get_group_desc(sb, g, NULL);
6588 
6589 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6590 					ext4_msg(sb, KERN_ERR,
6591 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6592 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6593 					       le16_to_cpu(gdp->bg_checksum));
6594 					err = -EFSBADCRC;
6595 					goto restore_opts;
6596 				}
6597 			}
6598 
6599 			/*
6600 			 * If we have an unprocessed orphan list hanging
6601 			 * around from a previously readonly bdev mount,
6602 			 * require a full umount/remount for now.
6603 			 */
6604 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6605 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6606 				       "remount RDWR because of unprocessed "
6607 				       "orphan inode list.  Please "
6608 				       "umount/remount instead");
6609 				err = -EINVAL;
6610 				goto restore_opts;
6611 			}
6612 
6613 			/*
6614 			 * Mounting a RDONLY partition read-write, so reread
6615 			 * and store the current valid flag.  (It may have
6616 			 * been changed by e2fsck since we originally mounted
6617 			 * the partition.)
6618 			 */
6619 			if (sbi->s_journal) {
6620 				err = ext4_clear_journal_err(sb, es);
6621 				if (err)
6622 					goto restore_opts;
6623 			}
6624 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6625 					      ~EXT4_FC_REPLAY);
6626 
6627 			err = ext4_setup_super(sb, es, 0);
6628 			if (err)
6629 				goto restore_opts;
6630 
6631 			sb->s_flags &= ~SB_RDONLY;
6632 			if (ext4_has_feature_mmp(sb)) {
6633 				err = ext4_multi_mount_protect(sb,
6634 						le64_to_cpu(es->s_mmp_block));
6635 				if (err)
6636 					goto restore_opts;
6637 			}
6638 #ifdef CONFIG_QUOTA
6639 			enable_quota = 1;
6640 #endif
6641 		}
6642 	}
6643 
6644 	/*
6645 	 * Handle creation of system zone data early because it can fail.
6646 	 * Releasing of existing data is done when we are sure remount will
6647 	 * succeed.
6648 	 */
6649 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6650 		err = ext4_setup_system_zone(sb);
6651 		if (err)
6652 			goto restore_opts;
6653 	}
6654 
6655 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6656 		err = ext4_commit_super(sb);
6657 		if (err)
6658 			goto restore_opts;
6659 	}
6660 
6661 #ifdef CONFIG_QUOTA
6662 	if (enable_quota) {
6663 		if (sb_any_quota_suspended(sb))
6664 			dquot_resume(sb, -1);
6665 		else if (ext4_has_feature_quota(sb)) {
6666 			err = ext4_enable_quotas(sb);
6667 			if (err)
6668 				goto restore_opts;
6669 		}
6670 	}
6671 	/* Release old quota file names */
6672 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6673 		kfree(old_opts.s_qf_names[i]);
6674 #endif
6675 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6676 		ext4_release_system_zone(sb);
6677 
6678 	/*
6679 	 * Reinitialize lazy itable initialization thread based on
6680 	 * current settings
6681 	 */
6682 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6683 		ext4_unregister_li_request(sb);
6684 	else {
6685 		ext4_group_t first_not_zeroed;
6686 		first_not_zeroed = ext4_has_uninit_itable(sb);
6687 		ext4_register_li_request(sb, first_not_zeroed);
6688 	}
6689 
6690 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6691 		ext4_stop_mmpd(sbi);
6692 
6693 	return 0;
6694 
6695 restore_opts:
6696 	/*
6697 	 * If there was a failing r/w to ro transition, we may need to
6698 	 * re-enable quota
6699 	 */
6700 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6701 	    sb_any_quota_suspended(sb))
6702 		dquot_resume(sb, -1);
6703 	sb->s_flags = old_sb_flags;
6704 	sbi->s_mount_opt = old_opts.s_mount_opt;
6705 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6706 	sbi->s_resuid = old_opts.s_resuid;
6707 	sbi->s_resgid = old_opts.s_resgid;
6708 	sbi->s_commit_interval = old_opts.s_commit_interval;
6709 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6710 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6711 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6712 		ext4_release_system_zone(sb);
6713 #ifdef CONFIG_QUOTA
6714 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6715 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6716 		to_free[i] = get_qf_name(sb, sbi, i);
6717 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6718 	}
6719 	synchronize_rcu();
6720 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6721 		kfree(to_free[i]);
6722 #endif
6723 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6724 		ext4_stop_mmpd(sbi);
6725 	return err;
6726 }
6727 
6728 static int ext4_reconfigure(struct fs_context *fc)
6729 {
6730 	struct super_block *sb = fc->root->d_sb;
6731 	int ret;
6732 
6733 	fc->s_fs_info = EXT4_SB(sb);
6734 
6735 	ret = ext4_check_opt_consistency(fc, sb);
6736 	if (ret < 0)
6737 		return ret;
6738 
6739 	ret = __ext4_remount(fc, sb);
6740 	if (ret < 0)
6741 		return ret;
6742 
6743 	ext4_msg(sb, KERN_INFO, "re-mounted %pU %s. Quota mode: %s.",
6744 		 &sb->s_uuid, sb_rdonly(sb) ? "ro" : "r/w",
6745 		 ext4_quota_mode(sb));
6746 
6747 	return 0;
6748 }
6749 
6750 #ifdef CONFIG_QUOTA
6751 static int ext4_statfs_project(struct super_block *sb,
6752 			       kprojid_t projid, struct kstatfs *buf)
6753 {
6754 	struct kqid qid;
6755 	struct dquot *dquot;
6756 	u64 limit;
6757 	u64 curblock;
6758 
6759 	qid = make_kqid_projid(projid);
6760 	dquot = dqget(sb, qid);
6761 	if (IS_ERR(dquot))
6762 		return PTR_ERR(dquot);
6763 	spin_lock(&dquot->dq_dqb_lock);
6764 
6765 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6766 			     dquot->dq_dqb.dqb_bhardlimit);
6767 	limit >>= sb->s_blocksize_bits;
6768 
6769 	if (limit && buf->f_blocks > limit) {
6770 		curblock = (dquot->dq_dqb.dqb_curspace +
6771 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6772 		buf->f_blocks = limit;
6773 		buf->f_bfree = buf->f_bavail =
6774 			(buf->f_blocks > curblock) ?
6775 			 (buf->f_blocks - curblock) : 0;
6776 	}
6777 
6778 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6779 			     dquot->dq_dqb.dqb_ihardlimit);
6780 	if (limit && buf->f_files > limit) {
6781 		buf->f_files = limit;
6782 		buf->f_ffree =
6783 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6784 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6785 	}
6786 
6787 	spin_unlock(&dquot->dq_dqb_lock);
6788 	dqput(dquot);
6789 	return 0;
6790 }
6791 #endif
6792 
6793 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6794 {
6795 	struct super_block *sb = dentry->d_sb;
6796 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6797 	struct ext4_super_block *es = sbi->s_es;
6798 	ext4_fsblk_t overhead = 0, resv_blocks;
6799 	s64 bfree;
6800 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6801 
6802 	if (!test_opt(sb, MINIX_DF))
6803 		overhead = sbi->s_overhead;
6804 
6805 	buf->f_type = EXT4_SUPER_MAGIC;
6806 	buf->f_bsize = sb->s_blocksize;
6807 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6808 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6809 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6810 	/* prevent underflow in case that few free space is available */
6811 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6812 	buf->f_bavail = buf->f_bfree -
6813 			(ext4_r_blocks_count(es) + resv_blocks);
6814 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6815 		buf->f_bavail = 0;
6816 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6817 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6818 	buf->f_namelen = EXT4_NAME_LEN;
6819 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6820 
6821 #ifdef CONFIG_QUOTA
6822 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6823 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6824 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6825 #endif
6826 	return 0;
6827 }
6828 
6829 
6830 #ifdef CONFIG_QUOTA
6831 
6832 /*
6833  * Helper functions so that transaction is started before we acquire dqio_sem
6834  * to keep correct lock ordering of transaction > dqio_sem
6835  */
6836 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6837 {
6838 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6839 }
6840 
6841 static int ext4_write_dquot(struct dquot *dquot)
6842 {
6843 	int ret, err;
6844 	handle_t *handle;
6845 	struct inode *inode;
6846 
6847 	inode = dquot_to_inode(dquot);
6848 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6849 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6850 	if (IS_ERR(handle))
6851 		return PTR_ERR(handle);
6852 	ret = dquot_commit(dquot);
6853 	err = ext4_journal_stop(handle);
6854 	if (!ret)
6855 		ret = err;
6856 	return ret;
6857 }
6858 
6859 static int ext4_acquire_dquot(struct dquot *dquot)
6860 {
6861 	int ret, err;
6862 	handle_t *handle;
6863 
6864 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6865 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6866 	if (IS_ERR(handle))
6867 		return PTR_ERR(handle);
6868 	ret = dquot_acquire(dquot);
6869 	err = ext4_journal_stop(handle);
6870 	if (!ret)
6871 		ret = err;
6872 	return ret;
6873 }
6874 
6875 static int ext4_release_dquot(struct dquot *dquot)
6876 {
6877 	int ret, err;
6878 	handle_t *handle;
6879 
6880 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6881 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6882 	if (IS_ERR(handle)) {
6883 		/* Release dquot anyway to avoid endless cycle in dqput() */
6884 		dquot_release(dquot);
6885 		return PTR_ERR(handle);
6886 	}
6887 	ret = dquot_release(dquot);
6888 	err = ext4_journal_stop(handle);
6889 	if (!ret)
6890 		ret = err;
6891 	return ret;
6892 }
6893 
6894 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6895 {
6896 	struct super_block *sb = dquot->dq_sb;
6897 
6898 	if (ext4_is_quota_journalled(sb)) {
6899 		dquot_mark_dquot_dirty(dquot);
6900 		return ext4_write_dquot(dquot);
6901 	} else {
6902 		return dquot_mark_dquot_dirty(dquot);
6903 	}
6904 }
6905 
6906 static int ext4_write_info(struct super_block *sb, int type)
6907 {
6908 	int ret, err;
6909 	handle_t *handle;
6910 
6911 	/* Data block + inode block */
6912 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6913 	if (IS_ERR(handle))
6914 		return PTR_ERR(handle);
6915 	ret = dquot_commit_info(sb, type);
6916 	err = ext4_journal_stop(handle);
6917 	if (!ret)
6918 		ret = err;
6919 	return ret;
6920 }
6921 
6922 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6923 {
6924 	struct ext4_inode_info *ei = EXT4_I(inode);
6925 
6926 	/* The first argument of lockdep_set_subclass has to be
6927 	 * *exactly* the same as the argument to init_rwsem() --- in
6928 	 * this case, in init_once() --- or lockdep gets unhappy
6929 	 * because the name of the lock is set using the
6930 	 * stringification of the argument to init_rwsem().
6931 	 */
6932 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6933 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6934 }
6935 
6936 /*
6937  * Standard function to be called on quota_on
6938  */
6939 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6940 			 const struct path *path)
6941 {
6942 	int err;
6943 
6944 	if (!test_opt(sb, QUOTA))
6945 		return -EINVAL;
6946 
6947 	/* Quotafile not on the same filesystem? */
6948 	if (path->dentry->d_sb != sb)
6949 		return -EXDEV;
6950 
6951 	/* Quota already enabled for this file? */
6952 	if (IS_NOQUOTA(d_inode(path->dentry)))
6953 		return -EBUSY;
6954 
6955 	/* Journaling quota? */
6956 	if (EXT4_SB(sb)->s_qf_names[type]) {
6957 		/* Quotafile not in fs root? */
6958 		if (path->dentry->d_parent != sb->s_root)
6959 			ext4_msg(sb, KERN_WARNING,
6960 				"Quota file not on filesystem root. "
6961 				"Journaled quota will not work");
6962 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6963 	} else {
6964 		/*
6965 		 * Clear the flag just in case mount options changed since
6966 		 * last time.
6967 		 */
6968 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6969 	}
6970 
6971 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6972 	err = dquot_quota_on(sb, type, format_id, path);
6973 	if (!err) {
6974 		struct inode *inode = d_inode(path->dentry);
6975 		handle_t *handle;
6976 
6977 		/*
6978 		 * Set inode flags to prevent userspace from messing with quota
6979 		 * files. If this fails, we return success anyway since quotas
6980 		 * are already enabled and this is not a hard failure.
6981 		 */
6982 		inode_lock(inode);
6983 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6984 		if (IS_ERR(handle))
6985 			goto unlock_inode;
6986 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6987 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6988 				S_NOATIME | S_IMMUTABLE);
6989 		err = ext4_mark_inode_dirty(handle, inode);
6990 		ext4_journal_stop(handle);
6991 	unlock_inode:
6992 		inode_unlock(inode);
6993 		if (err)
6994 			dquot_quota_off(sb, type);
6995 	}
6996 	if (err)
6997 		lockdep_set_quota_inode(path->dentry->d_inode,
6998 					     I_DATA_SEM_NORMAL);
6999 	return err;
7000 }
7001 
7002 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
7003 {
7004 	switch (type) {
7005 	case USRQUOTA:
7006 		return qf_inum == EXT4_USR_QUOTA_INO;
7007 	case GRPQUOTA:
7008 		return qf_inum == EXT4_GRP_QUOTA_INO;
7009 	case PRJQUOTA:
7010 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7011 	default:
7012 		BUG();
7013 	}
7014 }
7015 
7016 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7017 			     unsigned int flags)
7018 {
7019 	int err;
7020 	struct inode *qf_inode;
7021 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7022 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7023 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7024 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7025 	};
7026 
7027 	BUG_ON(!ext4_has_feature_quota(sb));
7028 
7029 	if (!qf_inums[type])
7030 		return -EPERM;
7031 
7032 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7033 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7034 				qf_inums[type], type);
7035 		return -EUCLEAN;
7036 	}
7037 
7038 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7039 	if (IS_ERR(qf_inode)) {
7040 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7041 				qf_inums[type], type);
7042 		return PTR_ERR(qf_inode);
7043 	}
7044 
7045 	/* Don't account quota for quota files to avoid recursion */
7046 	qf_inode->i_flags |= S_NOQUOTA;
7047 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7048 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7049 	if (err)
7050 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7051 	iput(qf_inode);
7052 
7053 	return err;
7054 }
7055 
7056 /* Enable usage tracking for all quota types. */
7057 int ext4_enable_quotas(struct super_block *sb)
7058 {
7059 	int type, err = 0;
7060 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7061 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7062 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7063 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7064 	};
7065 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7066 		test_opt(sb, USRQUOTA),
7067 		test_opt(sb, GRPQUOTA),
7068 		test_opt(sb, PRJQUOTA),
7069 	};
7070 
7071 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7072 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7073 		if (qf_inums[type]) {
7074 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7075 				DQUOT_USAGE_ENABLED |
7076 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7077 			if (err) {
7078 				ext4_warning(sb,
7079 					"Failed to enable quota tracking "
7080 					"(type=%d, err=%d, ino=%lu). "
7081 					"Please run e2fsck to fix.", type,
7082 					err, qf_inums[type]);
7083 
7084 				ext4_quotas_off(sb, type);
7085 				return err;
7086 			}
7087 		}
7088 	}
7089 	return 0;
7090 }
7091 
7092 static int ext4_quota_off(struct super_block *sb, int type)
7093 {
7094 	struct inode *inode = sb_dqopt(sb)->files[type];
7095 	handle_t *handle;
7096 	int err;
7097 
7098 	/* Force all delayed allocation blocks to be allocated.
7099 	 * Caller already holds s_umount sem */
7100 	if (test_opt(sb, DELALLOC))
7101 		sync_filesystem(sb);
7102 
7103 	if (!inode || !igrab(inode))
7104 		goto out;
7105 
7106 	err = dquot_quota_off(sb, type);
7107 	if (err || ext4_has_feature_quota(sb))
7108 		goto out_put;
7109 	/*
7110 	 * When the filesystem was remounted read-only first, we cannot cleanup
7111 	 * inode flags here. Bad luck but people should be using QUOTA feature
7112 	 * these days anyway.
7113 	 */
7114 	if (sb_rdonly(sb))
7115 		goto out_put;
7116 
7117 	inode_lock(inode);
7118 	/*
7119 	 * Update modification times of quota files when userspace can
7120 	 * start looking at them. If we fail, we return success anyway since
7121 	 * this is not a hard failure and quotas are already disabled.
7122 	 */
7123 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7124 	if (IS_ERR(handle)) {
7125 		err = PTR_ERR(handle);
7126 		goto out_unlock;
7127 	}
7128 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7129 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7130 	inode->i_mtime = inode_set_ctime_current(inode);
7131 	err = ext4_mark_inode_dirty(handle, inode);
7132 	ext4_journal_stop(handle);
7133 out_unlock:
7134 	inode_unlock(inode);
7135 out_put:
7136 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7137 	iput(inode);
7138 	return err;
7139 out:
7140 	return dquot_quota_off(sb, type);
7141 }
7142 
7143 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7144  * acquiring the locks... As quota files are never truncated and quota code
7145  * itself serializes the operations (and no one else should touch the files)
7146  * we don't have to be afraid of races */
7147 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7148 			       size_t len, loff_t off)
7149 {
7150 	struct inode *inode = sb_dqopt(sb)->files[type];
7151 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7152 	int offset = off & (sb->s_blocksize - 1);
7153 	int tocopy;
7154 	size_t toread;
7155 	struct buffer_head *bh;
7156 	loff_t i_size = i_size_read(inode);
7157 
7158 	if (off > i_size)
7159 		return 0;
7160 	if (off+len > i_size)
7161 		len = i_size-off;
7162 	toread = len;
7163 	while (toread > 0) {
7164 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7165 		bh = ext4_bread(NULL, inode, blk, 0);
7166 		if (IS_ERR(bh))
7167 			return PTR_ERR(bh);
7168 		if (!bh)	/* A hole? */
7169 			memset(data, 0, tocopy);
7170 		else
7171 			memcpy(data, bh->b_data+offset, tocopy);
7172 		brelse(bh);
7173 		offset = 0;
7174 		toread -= tocopy;
7175 		data += tocopy;
7176 		blk++;
7177 	}
7178 	return len;
7179 }
7180 
7181 /* Write to quotafile (we know the transaction is already started and has
7182  * enough credits) */
7183 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7184 				const char *data, size_t len, loff_t off)
7185 {
7186 	struct inode *inode = sb_dqopt(sb)->files[type];
7187 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7188 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7189 	int retries = 0;
7190 	struct buffer_head *bh;
7191 	handle_t *handle = journal_current_handle();
7192 
7193 	if (!handle) {
7194 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7195 			" cancelled because transaction is not started",
7196 			(unsigned long long)off, (unsigned long long)len);
7197 		return -EIO;
7198 	}
7199 	/*
7200 	 * Since we account only one data block in transaction credits,
7201 	 * then it is impossible to cross a block boundary.
7202 	 */
7203 	if (sb->s_blocksize - offset < len) {
7204 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7205 			" cancelled because not block aligned",
7206 			(unsigned long long)off, (unsigned long long)len);
7207 		return -EIO;
7208 	}
7209 
7210 	do {
7211 		bh = ext4_bread(handle, inode, blk,
7212 				EXT4_GET_BLOCKS_CREATE |
7213 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7214 	} while (PTR_ERR(bh) == -ENOSPC &&
7215 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7216 	if (IS_ERR(bh))
7217 		return PTR_ERR(bh);
7218 	if (!bh)
7219 		goto out;
7220 	BUFFER_TRACE(bh, "get write access");
7221 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7222 	if (err) {
7223 		brelse(bh);
7224 		return err;
7225 	}
7226 	lock_buffer(bh);
7227 	memcpy(bh->b_data+offset, data, len);
7228 	flush_dcache_page(bh->b_page);
7229 	unlock_buffer(bh);
7230 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7231 	brelse(bh);
7232 out:
7233 	if (inode->i_size < off + len) {
7234 		i_size_write(inode, off + len);
7235 		EXT4_I(inode)->i_disksize = inode->i_size;
7236 		err2 = ext4_mark_inode_dirty(handle, inode);
7237 		if (unlikely(err2 && !err))
7238 			err = err2;
7239 	}
7240 	return err ? err : len;
7241 }
7242 #endif
7243 
7244 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7245 static inline void register_as_ext2(void)
7246 {
7247 	int err = register_filesystem(&ext2_fs_type);
7248 	if (err)
7249 		printk(KERN_WARNING
7250 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7251 }
7252 
7253 static inline void unregister_as_ext2(void)
7254 {
7255 	unregister_filesystem(&ext2_fs_type);
7256 }
7257 
7258 static inline int ext2_feature_set_ok(struct super_block *sb)
7259 {
7260 	if (ext4_has_unknown_ext2_incompat_features(sb))
7261 		return 0;
7262 	if (sb_rdonly(sb))
7263 		return 1;
7264 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7265 		return 0;
7266 	return 1;
7267 }
7268 #else
7269 static inline void register_as_ext2(void) { }
7270 static inline void unregister_as_ext2(void) { }
7271 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7272 #endif
7273 
7274 static inline void register_as_ext3(void)
7275 {
7276 	int err = register_filesystem(&ext3_fs_type);
7277 	if (err)
7278 		printk(KERN_WARNING
7279 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7280 }
7281 
7282 static inline void unregister_as_ext3(void)
7283 {
7284 	unregister_filesystem(&ext3_fs_type);
7285 }
7286 
7287 static inline int ext3_feature_set_ok(struct super_block *sb)
7288 {
7289 	if (ext4_has_unknown_ext3_incompat_features(sb))
7290 		return 0;
7291 	if (!ext4_has_feature_journal(sb))
7292 		return 0;
7293 	if (sb_rdonly(sb))
7294 		return 1;
7295 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7296 		return 0;
7297 	return 1;
7298 }
7299 
7300 static void ext4_kill_sb(struct super_block *sb)
7301 {
7302 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7303 	struct block_device *journal_bdev = sbi ? sbi->s_journal_bdev : NULL;
7304 
7305 	kill_block_super(sb);
7306 
7307 	if (journal_bdev)
7308 		blkdev_put(journal_bdev, sb);
7309 }
7310 
7311 static struct file_system_type ext4_fs_type = {
7312 	.owner			= THIS_MODULE,
7313 	.name			= "ext4",
7314 	.init_fs_context	= ext4_init_fs_context,
7315 	.parameters		= ext4_param_specs,
7316 	.kill_sb		= ext4_kill_sb,
7317 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7318 };
7319 MODULE_ALIAS_FS("ext4");
7320 
7321 /* Shared across all ext4 file systems */
7322 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7323 
7324 static int __init ext4_init_fs(void)
7325 {
7326 	int i, err;
7327 
7328 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7329 	ext4_li_info = NULL;
7330 
7331 	/* Build-time check for flags consistency */
7332 	ext4_check_flag_values();
7333 
7334 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7335 		init_waitqueue_head(&ext4__ioend_wq[i]);
7336 
7337 	err = ext4_init_es();
7338 	if (err)
7339 		return err;
7340 
7341 	err = ext4_init_pending();
7342 	if (err)
7343 		goto out7;
7344 
7345 	err = ext4_init_post_read_processing();
7346 	if (err)
7347 		goto out6;
7348 
7349 	err = ext4_init_pageio();
7350 	if (err)
7351 		goto out5;
7352 
7353 	err = ext4_init_system_zone();
7354 	if (err)
7355 		goto out4;
7356 
7357 	err = ext4_init_sysfs();
7358 	if (err)
7359 		goto out3;
7360 
7361 	err = ext4_init_mballoc();
7362 	if (err)
7363 		goto out2;
7364 	err = init_inodecache();
7365 	if (err)
7366 		goto out1;
7367 
7368 	err = ext4_fc_init_dentry_cache();
7369 	if (err)
7370 		goto out05;
7371 
7372 	register_as_ext3();
7373 	register_as_ext2();
7374 	err = register_filesystem(&ext4_fs_type);
7375 	if (err)
7376 		goto out;
7377 
7378 	return 0;
7379 out:
7380 	unregister_as_ext2();
7381 	unregister_as_ext3();
7382 	ext4_fc_destroy_dentry_cache();
7383 out05:
7384 	destroy_inodecache();
7385 out1:
7386 	ext4_exit_mballoc();
7387 out2:
7388 	ext4_exit_sysfs();
7389 out3:
7390 	ext4_exit_system_zone();
7391 out4:
7392 	ext4_exit_pageio();
7393 out5:
7394 	ext4_exit_post_read_processing();
7395 out6:
7396 	ext4_exit_pending();
7397 out7:
7398 	ext4_exit_es();
7399 
7400 	return err;
7401 }
7402 
7403 static void __exit ext4_exit_fs(void)
7404 {
7405 	ext4_destroy_lazyinit_thread();
7406 	unregister_as_ext2();
7407 	unregister_as_ext3();
7408 	unregister_filesystem(&ext4_fs_type);
7409 	ext4_fc_destroy_dentry_cache();
7410 	destroy_inodecache();
7411 	ext4_exit_mballoc();
7412 	ext4_exit_sysfs();
7413 	ext4_exit_system_zone();
7414 	ext4_exit_pageio();
7415 	ext4_exit_post_read_processing();
7416 	ext4_exit_es();
7417 	ext4_exit_pending();
7418 }
7419 
7420 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7421 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7422 MODULE_LICENSE("GPL");
7423 MODULE_SOFTDEP("pre: crc32c");
7424 module_init(ext4_init_fs)
7425 module_exit(ext4_exit_fs)
7426