xref: /openbmc/linux/fs/ext4/super.c (revision e5242c5f)
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, bool simu_fail)
165 {
166 	if (simu_fail) {
167 		clear_buffer_uptodate(bh);
168 		unlock_buffer(bh);
169 		return;
170 	}
171 
172 	/*
173 	 * buffer's verified bit is no longer valid after reading from
174 	 * disk again due to write out error, clear it to make sure we
175 	 * recheck the buffer contents.
176 	 */
177 	clear_buffer_verified(bh);
178 
179 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
180 	get_bh(bh);
181 	submit_bh(REQ_OP_READ | op_flags, bh);
182 }
183 
184 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
185 			 bh_end_io_t *end_io, bool simu_fail)
186 {
187 	BUG_ON(!buffer_locked(bh));
188 
189 	if (ext4_buffer_uptodate(bh)) {
190 		unlock_buffer(bh);
191 		return;
192 	}
193 	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
194 }
195 
196 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
197 		 bh_end_io_t *end_io, bool simu_fail)
198 {
199 	BUG_ON(!buffer_locked(bh));
200 
201 	if (ext4_buffer_uptodate(bh)) {
202 		unlock_buffer(bh);
203 		return 0;
204 	}
205 
206 	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
207 
208 	wait_on_buffer(bh);
209 	if (buffer_uptodate(bh))
210 		return 0;
211 	return -EIO;
212 }
213 
214 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
215 {
216 	lock_buffer(bh);
217 	if (!wait) {
218 		ext4_read_bh_nowait(bh, op_flags, NULL, false);
219 		return 0;
220 	}
221 	return ext4_read_bh(bh, op_flags, NULL, false);
222 }
223 
224 /*
225  * This works like __bread_gfp() except it uses ERR_PTR for error
226  * returns.  Currently with sb_bread it's impossible to distinguish
227  * between ENOMEM and EIO situations (since both result in a NULL
228  * return.
229  */
230 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
231 					       sector_t block,
232 					       blk_opf_t op_flags, gfp_t gfp)
233 {
234 	struct buffer_head *bh;
235 	int ret;
236 
237 	bh = sb_getblk_gfp(sb, block, gfp);
238 	if (bh == NULL)
239 		return ERR_PTR(-ENOMEM);
240 	if (ext4_buffer_uptodate(bh))
241 		return bh;
242 
243 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
244 	if (ret) {
245 		put_bh(bh);
246 		return ERR_PTR(ret);
247 	}
248 	return bh;
249 }
250 
251 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
252 				   blk_opf_t op_flags)
253 {
254 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
255 }
256 
257 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
258 					    sector_t block)
259 {
260 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
261 }
262 
263 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
264 {
265 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
266 
267 	if (likely(bh)) {
268 		if (trylock_buffer(bh))
269 			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL, false);
270 		brelse(bh);
271 	}
272 }
273 
274 static int ext4_verify_csum_type(struct super_block *sb,
275 				 struct ext4_super_block *es)
276 {
277 	if (!ext4_has_feature_metadata_csum(sb))
278 		return 1;
279 
280 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
281 }
282 
283 __le32 ext4_superblock_csum(struct super_block *sb,
284 			    struct ext4_super_block *es)
285 {
286 	struct ext4_sb_info *sbi = EXT4_SB(sb);
287 	int offset = offsetof(struct ext4_super_block, s_checksum);
288 	__u32 csum;
289 
290 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
291 
292 	return cpu_to_le32(csum);
293 }
294 
295 static int ext4_superblock_csum_verify(struct super_block *sb,
296 				       struct ext4_super_block *es)
297 {
298 	if (!ext4_has_metadata_csum(sb))
299 		return 1;
300 
301 	return es->s_checksum == ext4_superblock_csum(sb, es);
302 }
303 
304 void ext4_superblock_csum_set(struct super_block *sb)
305 {
306 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
307 
308 	if (!ext4_has_metadata_csum(sb))
309 		return;
310 
311 	es->s_checksum = ext4_superblock_csum(sb, es);
312 }
313 
314 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
323 			       struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
328 }
329 
330 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
331 			      struct ext4_group_desc *bg)
332 {
333 	return le32_to_cpu(bg->bg_inode_table_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
336 }
337 
338 __u32 ext4_free_group_clusters(struct super_block *sb,
339 			       struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_free_inodes_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(READ_ONCE(bg->bg_free_inodes_count_lo)) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(READ_ONCE(bg->bg_free_inodes_count_hi)) << 16 : 0);
352 }
353 
354 __u32 ext4_used_dirs_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
360 }
361 
362 __u32 ext4_itable_unused_count(struct super_block *sb,
363 			      struct ext4_group_desc *bg)
364 {
365 	return le16_to_cpu(bg->bg_itable_unused_lo) |
366 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
367 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
368 }
369 
370 void ext4_block_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_bitmap_set(struct super_block *sb,
379 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_inode_table_set(struct super_block *sb,
387 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
388 {
389 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
392 }
393 
394 void ext4_free_group_clusters_set(struct super_block *sb,
395 				  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_free_inodes_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	WRITE_ONCE(bg->bg_free_inodes_count_lo, cpu_to_le16((__u16)count));
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		WRITE_ONCE(bg->bg_free_inodes_count_hi, cpu_to_le16(count >> 16));
408 }
409 
410 void ext4_used_dirs_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
416 }
417 
418 void ext4_itable_unused_set(struct super_block *sb,
419 			  struct ext4_group_desc *bg, __u32 count)
420 {
421 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
422 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
423 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
424 }
425 
426 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
427 {
428 	now = clamp_val(now, 0, (1ull << 40) - 1);
429 
430 	*lo = cpu_to_le32(lower_32_bits(now));
431 	*hi = upper_32_bits(now);
432 }
433 
434 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
435 {
436 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
437 }
438 #define ext4_update_tstamp(es, tstamp) \
439 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
440 			     ktime_get_real_seconds())
441 #define ext4_get_tstamp(es, tstamp) \
442 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
443 
444 #define EXT4_SB_REFRESH_INTERVAL_SEC (3600) /* seconds (1 hour) */
445 #define EXT4_SB_REFRESH_INTERVAL_KB (16384) /* kilobytes (16MB) */
446 
447 /*
448  * The ext4_maybe_update_superblock() function checks and updates the
449  * superblock if needed.
450  *
451  * This function is designed to update the on-disk superblock only under
452  * certain conditions to prevent excessive disk writes and unnecessary
453  * waking of the disk from sleep. The superblock will be updated if:
454  * 1. More than an hour has passed since the last superblock update, and
455  * 2. More than 16MB have been written since the last superblock update.
456  *
457  * @sb: The superblock
458  */
459 static void ext4_maybe_update_superblock(struct super_block *sb)
460 {
461 	struct ext4_sb_info *sbi = EXT4_SB(sb);
462 	struct ext4_super_block *es = sbi->s_es;
463 	journal_t *journal = sbi->s_journal;
464 	time64_t now;
465 	__u64 last_update;
466 	__u64 lifetime_write_kbytes;
467 	__u64 diff_size;
468 
469 	if (sb_rdonly(sb) || !(sb->s_flags & SB_ACTIVE) ||
470 	    !journal || (journal->j_flags & JBD2_UNMOUNT))
471 		return;
472 
473 	now = ktime_get_real_seconds();
474 	last_update = ext4_get_tstamp(es, s_wtime);
475 
476 	if (likely(now - last_update < EXT4_SB_REFRESH_INTERVAL_SEC))
477 		return;
478 
479 	lifetime_write_kbytes = sbi->s_kbytes_written +
480 		((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
481 		  sbi->s_sectors_written_start) >> 1);
482 
483 	/* Get the number of kilobytes not written to disk to account
484 	 * for statistics and compare with a multiple of 16 MB. This
485 	 * is used to determine when the next superblock commit should
486 	 * occur (i.e. not more often than once per 16MB if there was
487 	 * less written in an hour).
488 	 */
489 	diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written);
490 
491 	if (diff_size > EXT4_SB_REFRESH_INTERVAL_KB)
492 		schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
493 }
494 
495 /*
496  * The del_gendisk() function uninitializes the disk-specific data
497  * structures, including the bdi structure, without telling anyone
498  * else.  Once this happens, any attempt to call mark_buffer_dirty()
499  * (for example, by ext4_commit_super), will cause a kernel OOPS.
500  * This is a kludge to prevent these oops until we can put in a proper
501  * hook in del_gendisk() to inform the VFS and file system layers.
502  */
503 static int block_device_ejected(struct super_block *sb)
504 {
505 	struct inode *bd_inode = sb->s_bdev->bd_inode;
506 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
507 
508 	return bdi->dev == NULL;
509 }
510 
511 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
512 {
513 	struct super_block		*sb = journal->j_private;
514 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
515 	int				error = is_journal_aborted(journal);
516 	struct ext4_journal_cb_entry	*jce;
517 
518 	BUG_ON(txn->t_state == T_FINISHED);
519 
520 	ext4_process_freed_data(sb, txn->t_tid);
521 	ext4_maybe_update_superblock(sb);
522 
523 	spin_lock(&sbi->s_md_lock);
524 	while (!list_empty(&txn->t_private_list)) {
525 		jce = list_entry(txn->t_private_list.next,
526 				 struct ext4_journal_cb_entry, jce_list);
527 		list_del_init(&jce->jce_list);
528 		spin_unlock(&sbi->s_md_lock);
529 		jce->jce_func(sb, jce, error);
530 		spin_lock(&sbi->s_md_lock);
531 	}
532 	spin_unlock(&sbi->s_md_lock);
533 }
534 
535 /*
536  * This writepage callback for write_cache_pages()
537  * takes care of a few cases after page cleaning.
538  *
539  * write_cache_pages() already checks for dirty pages
540  * and calls clear_page_dirty_for_io(), which we want,
541  * to write protect the pages.
542  *
543  * However, we may have to redirty a page (see below.)
544  */
545 static int ext4_journalled_writepage_callback(struct folio *folio,
546 					      struct writeback_control *wbc,
547 					      void *data)
548 {
549 	transaction_t *transaction = (transaction_t *) data;
550 	struct buffer_head *bh, *head;
551 	struct journal_head *jh;
552 
553 	bh = head = folio_buffers(folio);
554 	do {
555 		/*
556 		 * We have to redirty a page in these cases:
557 		 * 1) If buffer is dirty, it means the page was dirty because it
558 		 * contains a buffer that needs checkpointing. So the dirty bit
559 		 * needs to be preserved so that checkpointing writes the buffer
560 		 * properly.
561 		 * 2) If buffer is not part of the committing transaction
562 		 * (we may have just accidentally come across this buffer because
563 		 * inode range tracking is not exact) or if the currently running
564 		 * transaction already contains this buffer as well, dirty bit
565 		 * needs to be preserved so that the buffer gets writeprotected
566 		 * properly on running transaction's commit.
567 		 */
568 		jh = bh2jh(bh);
569 		if (buffer_dirty(bh) ||
570 		    (jh && (jh->b_transaction != transaction ||
571 			    jh->b_next_transaction))) {
572 			folio_redirty_for_writepage(wbc, folio);
573 			goto out;
574 		}
575 	} while ((bh = bh->b_this_page) != head);
576 
577 out:
578 	return AOP_WRITEPAGE_ACTIVATE;
579 }
580 
581 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
582 {
583 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
584 	struct writeback_control wbc = {
585 		.sync_mode =  WB_SYNC_ALL,
586 		.nr_to_write = LONG_MAX,
587 		.range_start = jinode->i_dirty_start,
588 		.range_end = jinode->i_dirty_end,
589         };
590 
591 	return write_cache_pages(mapping, &wbc,
592 				 ext4_journalled_writepage_callback,
593 				 jinode->i_transaction);
594 }
595 
596 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
597 {
598 	int ret;
599 
600 	if (ext4_should_journal_data(jinode->i_vfs_inode))
601 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
602 	else
603 		ret = ext4_normal_submit_inode_data_buffers(jinode);
604 	return ret;
605 }
606 
607 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
608 {
609 	int ret = 0;
610 
611 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
612 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
613 
614 	return ret;
615 }
616 
617 static bool system_going_down(void)
618 {
619 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
620 		|| system_state == SYSTEM_RESTART;
621 }
622 
623 struct ext4_err_translation {
624 	int code;
625 	int errno;
626 };
627 
628 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
629 
630 static struct ext4_err_translation err_translation[] = {
631 	EXT4_ERR_TRANSLATE(EIO),
632 	EXT4_ERR_TRANSLATE(ENOMEM),
633 	EXT4_ERR_TRANSLATE(EFSBADCRC),
634 	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
635 	EXT4_ERR_TRANSLATE(ENOSPC),
636 	EXT4_ERR_TRANSLATE(ENOKEY),
637 	EXT4_ERR_TRANSLATE(EROFS),
638 	EXT4_ERR_TRANSLATE(EFBIG),
639 	EXT4_ERR_TRANSLATE(EEXIST),
640 	EXT4_ERR_TRANSLATE(ERANGE),
641 	EXT4_ERR_TRANSLATE(EOVERFLOW),
642 	EXT4_ERR_TRANSLATE(EBUSY),
643 	EXT4_ERR_TRANSLATE(ENOTDIR),
644 	EXT4_ERR_TRANSLATE(ENOTEMPTY),
645 	EXT4_ERR_TRANSLATE(ESHUTDOWN),
646 	EXT4_ERR_TRANSLATE(EFAULT),
647 };
648 
649 static int ext4_errno_to_code(int errno)
650 {
651 	int i;
652 
653 	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
654 		if (err_translation[i].errno == errno)
655 			return err_translation[i].code;
656 	return EXT4_ERR_UNKNOWN;
657 }
658 
659 static void save_error_info(struct super_block *sb, int error,
660 			    __u32 ino, __u64 block,
661 			    const char *func, unsigned int line)
662 {
663 	struct ext4_sb_info *sbi = EXT4_SB(sb);
664 
665 	/* We default to EFSCORRUPTED error... */
666 	if (error == 0)
667 		error = EFSCORRUPTED;
668 
669 	spin_lock(&sbi->s_error_lock);
670 	sbi->s_add_error_count++;
671 	sbi->s_last_error_code = error;
672 	sbi->s_last_error_line = line;
673 	sbi->s_last_error_ino = ino;
674 	sbi->s_last_error_block = block;
675 	sbi->s_last_error_func = func;
676 	sbi->s_last_error_time = ktime_get_real_seconds();
677 	if (!sbi->s_first_error_time) {
678 		sbi->s_first_error_code = error;
679 		sbi->s_first_error_line = line;
680 		sbi->s_first_error_ino = ino;
681 		sbi->s_first_error_block = block;
682 		sbi->s_first_error_func = func;
683 		sbi->s_first_error_time = sbi->s_last_error_time;
684 	}
685 	spin_unlock(&sbi->s_error_lock);
686 }
687 
688 /* Deal with the reporting of failure conditions on a filesystem such as
689  * inconsistencies detected or read IO failures.
690  *
691  * On ext2, we can store the error state of the filesystem in the
692  * superblock.  That is not possible on ext4, because we may have other
693  * write ordering constraints on the superblock which prevent us from
694  * writing it out straight away; and given that the journal is about to
695  * be aborted, we can't rely on the current, or future, transactions to
696  * write out the superblock safely.
697  *
698  * We'll just use the jbd2_journal_abort() error code to record an error in
699  * the journal instead.  On recovery, the journal will complain about
700  * that error until we've noted it down and cleared it.
701  *
702  * If force_ro is set, we unconditionally force the filesystem into an
703  * ABORT|READONLY state, unless the error response on the fs has been set to
704  * panic in which case we take the easy way out and panic immediately. This is
705  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
706  * at a critical moment in log management.
707  */
708 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
709 			      __u32 ino, __u64 block,
710 			      const char *func, unsigned int line)
711 {
712 	journal_t *journal = EXT4_SB(sb)->s_journal;
713 	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
714 
715 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
716 	if (test_opt(sb, WARN_ON_ERROR))
717 		WARN_ON_ONCE(1);
718 
719 	if (!continue_fs && !sb_rdonly(sb)) {
720 		set_bit(EXT4_FLAGS_SHUTDOWN, &EXT4_SB(sb)->s_ext4_flags);
721 		if (journal)
722 			jbd2_journal_abort(journal, -EIO);
723 	}
724 
725 	if (!bdev_read_only(sb->s_bdev)) {
726 		save_error_info(sb, error, ino, block, func, line);
727 		/*
728 		 * In case the fs should keep running, we need to writeout
729 		 * superblock through the journal. Due to lock ordering
730 		 * constraints, it may not be safe to do it right here so we
731 		 * defer superblock flushing to a workqueue.
732 		 */
733 		if (continue_fs && journal)
734 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
735 		else
736 			ext4_commit_super(sb);
737 	}
738 
739 	/*
740 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
741 	 * could panic during 'reboot -f' as the underlying device got already
742 	 * disabled.
743 	 */
744 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
745 		panic("EXT4-fs (device %s): panic forced after error\n",
746 			sb->s_id);
747 	}
748 
749 	if (sb_rdonly(sb) || continue_fs)
750 		return;
751 
752 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
753 	/*
754 	 * EXT4_FLAGS_SHUTDOWN was set which stops all filesystem
755 	 * modifications. We don't set SB_RDONLY because that requires
756 	 * sb->s_umount semaphore and setting it without proper remount
757 	 * procedure is confusing code such as freeze_super() leading to
758 	 * deadlocks and other problems.
759 	 */
760 }
761 
762 static void update_super_work(struct work_struct *work)
763 {
764 	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
765 						s_sb_upd_work);
766 	journal_t *journal = sbi->s_journal;
767 	handle_t *handle;
768 
769 	/*
770 	 * If the journal is still running, we have to write out superblock
771 	 * through the journal to avoid collisions of other journalled sb
772 	 * updates.
773 	 *
774 	 * We use directly jbd2 functions here to avoid recursing back into
775 	 * ext4 error handling code during handling of previous errors.
776 	 */
777 	if (!sb_rdonly(sbi->s_sb) && journal) {
778 		struct buffer_head *sbh = sbi->s_sbh;
779 		bool call_notify_err = false;
780 
781 		handle = jbd2_journal_start(journal, 1);
782 		if (IS_ERR(handle))
783 			goto write_directly;
784 		if (jbd2_journal_get_write_access(handle, sbh)) {
785 			jbd2_journal_stop(handle);
786 			goto write_directly;
787 		}
788 
789 		if (sbi->s_add_error_count > 0)
790 			call_notify_err = true;
791 
792 		ext4_update_super(sbi->s_sb);
793 		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
794 			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
795 				 "superblock detected");
796 			clear_buffer_write_io_error(sbh);
797 			set_buffer_uptodate(sbh);
798 		}
799 
800 		if (jbd2_journal_dirty_metadata(handle, sbh)) {
801 			jbd2_journal_stop(handle);
802 			goto write_directly;
803 		}
804 		jbd2_journal_stop(handle);
805 
806 		if (call_notify_err)
807 			ext4_notify_error_sysfs(sbi);
808 
809 		return;
810 	}
811 write_directly:
812 	/*
813 	 * Write through journal failed. Write sb directly to get error info
814 	 * out and hope for the best.
815 	 */
816 	ext4_commit_super(sbi->s_sb);
817 	ext4_notify_error_sysfs(sbi);
818 }
819 
820 #define ext4_error_ratelimit(sb)					\
821 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
822 			     "EXT4-fs error")
823 
824 void __ext4_error(struct super_block *sb, const char *function,
825 		  unsigned int line, bool force_ro, int error, __u64 block,
826 		  const char *fmt, ...)
827 {
828 	struct va_format vaf;
829 	va_list args;
830 
831 	if (unlikely(ext4_forced_shutdown(sb)))
832 		return;
833 
834 	trace_ext4_error(sb, function, line);
835 	if (ext4_error_ratelimit(sb)) {
836 		va_start(args, fmt);
837 		vaf.fmt = fmt;
838 		vaf.va = &args;
839 		printk(KERN_CRIT
840 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
841 		       sb->s_id, function, line, current->comm, &vaf);
842 		va_end(args);
843 	}
844 	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
845 
846 	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
847 }
848 
849 void __ext4_error_inode(struct inode *inode, const char *function,
850 			unsigned int line, ext4_fsblk_t block, int error,
851 			const char *fmt, ...)
852 {
853 	va_list args;
854 	struct va_format vaf;
855 
856 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
857 		return;
858 
859 	trace_ext4_error(inode->i_sb, function, line);
860 	if (ext4_error_ratelimit(inode->i_sb)) {
861 		va_start(args, fmt);
862 		vaf.fmt = fmt;
863 		vaf.va = &args;
864 		if (block)
865 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
866 			       "inode #%lu: block %llu: comm %s: %pV\n",
867 			       inode->i_sb->s_id, function, line, inode->i_ino,
868 			       block, current->comm, &vaf);
869 		else
870 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
871 			       "inode #%lu: comm %s: %pV\n",
872 			       inode->i_sb->s_id, function, line, inode->i_ino,
873 			       current->comm, &vaf);
874 		va_end(args);
875 	}
876 	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
877 
878 	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
879 			  function, line);
880 }
881 
882 void __ext4_error_file(struct file *file, const char *function,
883 		       unsigned int line, ext4_fsblk_t block,
884 		       const char *fmt, ...)
885 {
886 	va_list args;
887 	struct va_format vaf;
888 	struct inode *inode = file_inode(file);
889 	char pathname[80], *path;
890 
891 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
892 		return;
893 
894 	trace_ext4_error(inode->i_sb, function, line);
895 	if (ext4_error_ratelimit(inode->i_sb)) {
896 		path = file_path(file, pathname, sizeof(pathname));
897 		if (IS_ERR(path))
898 			path = "(unknown)";
899 		va_start(args, fmt);
900 		vaf.fmt = fmt;
901 		vaf.va = &args;
902 		if (block)
903 			printk(KERN_CRIT
904 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
905 			       "block %llu: comm %s: path %s: %pV\n",
906 			       inode->i_sb->s_id, function, line, inode->i_ino,
907 			       block, current->comm, path, &vaf);
908 		else
909 			printk(KERN_CRIT
910 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
911 			       "comm %s: path %s: %pV\n",
912 			       inode->i_sb->s_id, function, line, inode->i_ino,
913 			       current->comm, path, &vaf);
914 		va_end(args);
915 	}
916 	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
917 
918 	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
919 			  function, line);
920 }
921 
922 const char *ext4_decode_error(struct super_block *sb, int errno,
923 			      char nbuf[16])
924 {
925 	char *errstr = NULL;
926 
927 	switch (errno) {
928 	case -EFSCORRUPTED:
929 		errstr = "Corrupt filesystem";
930 		break;
931 	case -EFSBADCRC:
932 		errstr = "Filesystem failed CRC";
933 		break;
934 	case -EIO:
935 		errstr = "IO failure";
936 		break;
937 	case -ENOMEM:
938 		errstr = "Out of memory";
939 		break;
940 	case -EROFS:
941 		if (!sb || (EXT4_SB(sb)->s_journal &&
942 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
943 			errstr = "Journal has aborted";
944 		else
945 			errstr = "Readonly filesystem";
946 		break;
947 	default:
948 		/* If the caller passed in an extra buffer for unknown
949 		 * errors, textualise them now.  Else we just return
950 		 * NULL. */
951 		if (nbuf) {
952 			/* Check for truncated error codes... */
953 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
954 				errstr = nbuf;
955 		}
956 		break;
957 	}
958 
959 	return errstr;
960 }
961 
962 /* __ext4_std_error decodes expected errors from journaling functions
963  * automatically and invokes the appropriate error response.  */
964 
965 void __ext4_std_error(struct super_block *sb, const char *function,
966 		      unsigned int line, int errno)
967 {
968 	char nbuf[16];
969 	const char *errstr;
970 
971 	if (unlikely(ext4_forced_shutdown(sb)))
972 		return;
973 
974 	/* Special case: if the error is EROFS, and we're not already
975 	 * inside a transaction, then there's really no point in logging
976 	 * an error. */
977 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
978 		return;
979 
980 	if (ext4_error_ratelimit(sb)) {
981 		errstr = ext4_decode_error(sb, errno, nbuf);
982 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
983 		       sb->s_id, function, line, errstr);
984 	}
985 	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
986 
987 	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
988 }
989 
990 void __ext4_msg(struct super_block *sb,
991 		const char *prefix, const char *fmt, ...)
992 {
993 	struct va_format vaf;
994 	va_list args;
995 
996 	if (sb) {
997 		atomic_inc(&EXT4_SB(sb)->s_msg_count);
998 		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
999 				  "EXT4-fs"))
1000 			return;
1001 	}
1002 
1003 	va_start(args, fmt);
1004 	vaf.fmt = fmt;
1005 	vaf.va = &args;
1006 	if (sb)
1007 		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
1008 	else
1009 		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
1010 	va_end(args);
1011 }
1012 
1013 static int ext4_warning_ratelimit(struct super_block *sb)
1014 {
1015 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
1016 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
1017 			    "EXT4-fs warning");
1018 }
1019 
1020 void __ext4_warning(struct super_block *sb, const char *function,
1021 		    unsigned int line, const char *fmt, ...)
1022 {
1023 	struct va_format vaf;
1024 	va_list args;
1025 
1026 	if (!ext4_warning_ratelimit(sb))
1027 		return;
1028 
1029 	va_start(args, fmt);
1030 	vaf.fmt = fmt;
1031 	vaf.va = &args;
1032 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
1033 	       sb->s_id, function, line, &vaf);
1034 	va_end(args);
1035 }
1036 
1037 void __ext4_warning_inode(const struct inode *inode, const char *function,
1038 			  unsigned int line, const char *fmt, ...)
1039 {
1040 	struct va_format vaf;
1041 	va_list args;
1042 
1043 	if (!ext4_warning_ratelimit(inode->i_sb))
1044 		return;
1045 
1046 	va_start(args, fmt);
1047 	vaf.fmt = fmt;
1048 	vaf.va = &args;
1049 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
1050 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
1051 	       function, line, inode->i_ino, current->comm, &vaf);
1052 	va_end(args);
1053 }
1054 
1055 void __ext4_grp_locked_error(const char *function, unsigned int line,
1056 			     struct super_block *sb, ext4_group_t grp,
1057 			     unsigned long ino, ext4_fsblk_t block,
1058 			     const char *fmt, ...)
1059 __releases(bitlock)
1060 __acquires(bitlock)
1061 {
1062 	struct va_format vaf;
1063 	va_list args;
1064 
1065 	if (unlikely(ext4_forced_shutdown(sb)))
1066 		return;
1067 
1068 	trace_ext4_error(sb, function, line);
1069 	if (ext4_error_ratelimit(sb)) {
1070 		va_start(args, fmt);
1071 		vaf.fmt = fmt;
1072 		vaf.va = &args;
1073 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1074 		       sb->s_id, function, line, grp);
1075 		if (ino)
1076 			printk(KERN_CONT "inode %lu: ", ino);
1077 		if (block)
1078 			printk(KERN_CONT "block %llu:",
1079 			       (unsigned long long) block);
1080 		printk(KERN_CONT "%pV\n", &vaf);
1081 		va_end(args);
1082 	}
1083 
1084 	if (test_opt(sb, ERRORS_CONT)) {
1085 		if (test_opt(sb, WARN_ON_ERROR))
1086 			WARN_ON_ONCE(1);
1087 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1088 		if (!bdev_read_only(sb->s_bdev)) {
1089 			save_error_info(sb, EFSCORRUPTED, ino, block, function,
1090 					line);
1091 			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
1092 		}
1093 		return;
1094 	}
1095 	ext4_unlock_group(sb, grp);
1096 	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1097 	/*
1098 	 * We only get here in the ERRORS_RO case; relocking the group
1099 	 * may be dangerous, but nothing bad will happen since the
1100 	 * filesystem will have already been marked read/only and the
1101 	 * journal has been aborted.  We return 1 as a hint to callers
1102 	 * who might what to use the return value from
1103 	 * ext4_grp_locked_error() to distinguish between the
1104 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1105 	 * aggressively from the ext4 function in question, with a
1106 	 * more appropriate error code.
1107 	 */
1108 	ext4_lock_group(sb, grp);
1109 	return;
1110 }
1111 
1112 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1113 				     ext4_group_t group,
1114 				     unsigned int flags)
1115 {
1116 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1117 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1118 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1119 	int ret;
1120 
1121 	if (!grp || !gdp)
1122 		return;
1123 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1124 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1125 					    &grp->bb_state);
1126 		if (!ret)
1127 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1128 					   grp->bb_free);
1129 	}
1130 
1131 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1132 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1133 					    &grp->bb_state);
1134 		if (!ret && gdp) {
1135 			int count;
1136 
1137 			count = ext4_free_inodes_count(sb, gdp);
1138 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1139 					   count);
1140 		}
1141 	}
1142 }
1143 
1144 void ext4_update_dynamic_rev(struct super_block *sb)
1145 {
1146 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1147 
1148 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1149 		return;
1150 
1151 	ext4_warning(sb,
1152 		     "updating to rev %d because of new feature flag, "
1153 		     "running e2fsck is recommended",
1154 		     EXT4_DYNAMIC_REV);
1155 
1156 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1157 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1158 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1159 	/* leave es->s_feature_*compat flags alone */
1160 	/* es->s_uuid will be set by e2fsck if empty */
1161 
1162 	/*
1163 	 * The rest of the superblock fields should be zero, and if not it
1164 	 * means they are likely already in use, so leave them alone.  We
1165 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1166 	 */
1167 }
1168 
1169 static inline struct inode *orphan_list_entry(struct list_head *l)
1170 {
1171 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1172 }
1173 
1174 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1175 {
1176 	struct list_head *l;
1177 
1178 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1179 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1180 
1181 	printk(KERN_ERR "sb_info orphan list:\n");
1182 	list_for_each(l, &sbi->s_orphan) {
1183 		struct inode *inode = orphan_list_entry(l);
1184 		printk(KERN_ERR "  "
1185 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1186 		       inode->i_sb->s_id, inode->i_ino, inode,
1187 		       inode->i_mode, inode->i_nlink,
1188 		       NEXT_ORPHAN(inode));
1189 	}
1190 }
1191 
1192 #ifdef CONFIG_QUOTA
1193 static int ext4_quota_off(struct super_block *sb, int type);
1194 
1195 static inline void ext4_quotas_off(struct super_block *sb, int type)
1196 {
1197 	BUG_ON(type > EXT4_MAXQUOTAS);
1198 
1199 	/* Use our quota_off function to clear inode flags etc. */
1200 	for (type--; type >= 0; type--)
1201 		ext4_quota_off(sb, type);
1202 }
1203 
1204 /*
1205  * This is a helper function which is used in the mount/remount
1206  * codepaths (which holds s_umount) to fetch the quota file name.
1207  */
1208 static inline char *get_qf_name(struct super_block *sb,
1209 				struct ext4_sb_info *sbi,
1210 				int type)
1211 {
1212 	return rcu_dereference_protected(sbi->s_qf_names[type],
1213 					 lockdep_is_held(&sb->s_umount));
1214 }
1215 #else
1216 static inline void ext4_quotas_off(struct super_block *sb, int type)
1217 {
1218 }
1219 #endif
1220 
1221 static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
1222 {
1223 	ext4_fsblk_t block;
1224 	int err;
1225 
1226 	block = ext4_count_free_clusters(sbi->s_sb);
1227 	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
1228 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
1229 				  GFP_KERNEL);
1230 	if (!err) {
1231 		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
1232 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
1233 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
1234 					  GFP_KERNEL);
1235 	}
1236 	if (!err)
1237 		err = percpu_counter_init(&sbi->s_dirs_counter,
1238 					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
1239 	if (!err)
1240 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
1241 					  GFP_KERNEL);
1242 	if (!err)
1243 		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
1244 					  GFP_KERNEL);
1245 	if (!err)
1246 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
1247 
1248 	if (err)
1249 		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");
1250 
1251 	return err;
1252 }
1253 
1254 static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
1255 {
1256 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1257 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1258 	percpu_counter_destroy(&sbi->s_dirs_counter);
1259 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1260 	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1261 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1262 }
1263 
1264 static void ext4_group_desc_free(struct ext4_sb_info *sbi)
1265 {
1266 	struct buffer_head **group_desc;
1267 	int i;
1268 
1269 	rcu_read_lock();
1270 	group_desc = rcu_dereference(sbi->s_group_desc);
1271 	for (i = 0; i < sbi->s_gdb_count; i++)
1272 		brelse(group_desc[i]);
1273 	kvfree(group_desc);
1274 	rcu_read_unlock();
1275 }
1276 
1277 static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
1278 {
1279 	struct flex_groups **flex_groups;
1280 	int i;
1281 
1282 	rcu_read_lock();
1283 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1284 	if (flex_groups) {
1285 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1286 			kvfree(flex_groups[i]);
1287 		kvfree(flex_groups);
1288 	}
1289 	rcu_read_unlock();
1290 }
1291 
1292 static void ext4_put_super(struct super_block *sb)
1293 {
1294 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1295 	struct ext4_super_block *es = sbi->s_es;
1296 	int aborted = 0;
1297 	int err;
1298 
1299 	/*
1300 	 * Unregister sysfs before destroying jbd2 journal.
1301 	 * Since we could still access attr_journal_task attribute via sysfs
1302 	 * path which could have sbi->s_journal->j_task as NULL
1303 	 * Unregister sysfs before flush sbi->s_sb_upd_work.
1304 	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1305 	 * read metadata verify failed then will queue error work.
1306 	 * update_super_work will call start_this_handle may trigger
1307 	 * BUG_ON.
1308 	 */
1309 	ext4_unregister_sysfs(sb);
1310 
1311 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1312 		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
1313 			 &sb->s_uuid);
1314 
1315 	ext4_unregister_li_request(sb);
1316 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
1317 
1318 	flush_work(&sbi->s_sb_upd_work);
1319 	destroy_workqueue(sbi->rsv_conversion_wq);
1320 	ext4_release_orphan_info(sb);
1321 
1322 	if (sbi->s_journal) {
1323 		aborted = is_journal_aborted(sbi->s_journal);
1324 		err = jbd2_journal_destroy(sbi->s_journal);
1325 		sbi->s_journal = NULL;
1326 		if ((err < 0) && !aborted) {
1327 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1328 		}
1329 	}
1330 
1331 	ext4_es_unregister_shrinker(sbi);
1332 	timer_shutdown_sync(&sbi->s_err_report);
1333 	ext4_release_system_zone(sb);
1334 	ext4_mb_release(sb);
1335 	ext4_ext_release(sb);
1336 
1337 	if (!sb_rdonly(sb) && !aborted) {
1338 		ext4_clear_feature_journal_needs_recovery(sb);
1339 		ext4_clear_feature_orphan_present(sb);
1340 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1341 	}
1342 	if (!sb_rdonly(sb))
1343 		ext4_commit_super(sb);
1344 
1345 	ext4_group_desc_free(sbi);
1346 	ext4_flex_groups_free(sbi);
1347 	ext4_percpu_param_destroy(sbi);
1348 #ifdef CONFIG_QUOTA
1349 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
1350 		kfree(get_qf_name(sb, sbi, i));
1351 #endif
1352 
1353 	/* Debugging code just in case the in-memory inode orphan list
1354 	 * isn't empty.  The on-disk one can be non-empty if we've
1355 	 * detected an error and taken the fs readonly, but the
1356 	 * in-memory list had better be clean by this point. */
1357 	if (!list_empty(&sbi->s_orphan))
1358 		dump_orphan_list(sb, sbi);
1359 	ASSERT(list_empty(&sbi->s_orphan));
1360 
1361 	sync_blockdev(sb->s_bdev);
1362 	invalidate_bdev(sb->s_bdev);
1363 	if (sbi->s_journal_bdev) {
1364 		/*
1365 		 * Invalidate the journal device's buffers.  We don't want them
1366 		 * floating about in memory - the physical journal device may
1367 		 * hotswapped, and it breaks the `ro-after' testing code.
1368 		 */
1369 		sync_blockdev(sbi->s_journal_bdev);
1370 		invalidate_bdev(sbi->s_journal_bdev);
1371 	}
1372 
1373 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1374 	sbi->s_ea_inode_cache = NULL;
1375 
1376 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1377 	sbi->s_ea_block_cache = NULL;
1378 
1379 	ext4_stop_mmpd(sbi);
1380 
1381 	brelse(sbi->s_sbh);
1382 	sb->s_fs_info = NULL;
1383 	/*
1384 	 * Now that we are completely done shutting down the
1385 	 * superblock, we need to actually destroy the kobject.
1386 	 */
1387 	kobject_put(&sbi->s_kobj);
1388 	wait_for_completion(&sbi->s_kobj_unregister);
1389 	if (sbi->s_chksum_driver)
1390 		crypto_free_shash(sbi->s_chksum_driver);
1391 	kfree(sbi->s_blockgroup_lock);
1392 	fs_put_dax(sbi->s_daxdev, NULL);
1393 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1394 #if IS_ENABLED(CONFIG_UNICODE)
1395 	utf8_unload(sb->s_encoding);
1396 #endif
1397 	kfree(sbi);
1398 }
1399 
1400 static struct kmem_cache *ext4_inode_cachep;
1401 
1402 /*
1403  * Called inside transaction, so use GFP_NOFS
1404  */
1405 static struct inode *ext4_alloc_inode(struct super_block *sb)
1406 {
1407 	struct ext4_inode_info *ei;
1408 
1409 	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1410 	if (!ei)
1411 		return NULL;
1412 
1413 	inode_set_iversion(&ei->vfs_inode, 1);
1414 	ei->i_flags = 0;
1415 	spin_lock_init(&ei->i_raw_lock);
1416 	ei->i_prealloc_node = RB_ROOT;
1417 	atomic_set(&ei->i_prealloc_active, 0);
1418 	rwlock_init(&ei->i_prealloc_lock);
1419 	ext4_es_init_tree(&ei->i_es_tree);
1420 	rwlock_init(&ei->i_es_lock);
1421 	INIT_LIST_HEAD(&ei->i_es_list);
1422 	ei->i_es_all_nr = 0;
1423 	ei->i_es_shk_nr = 0;
1424 	ei->i_es_shrink_lblk = 0;
1425 	ei->i_reserved_data_blocks = 0;
1426 	spin_lock_init(&(ei->i_block_reservation_lock));
1427 	ext4_init_pending_tree(&ei->i_pending_tree);
1428 #ifdef CONFIG_QUOTA
1429 	ei->i_reserved_quota = 0;
1430 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1431 #endif
1432 	ei->jinode = NULL;
1433 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1434 	spin_lock_init(&ei->i_completed_io_lock);
1435 	ei->i_sync_tid = 0;
1436 	ei->i_datasync_tid = 0;
1437 	atomic_set(&ei->i_unwritten, 0);
1438 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1439 	ext4_fc_init_inode(&ei->vfs_inode);
1440 	mutex_init(&ei->i_fc_lock);
1441 	return &ei->vfs_inode;
1442 }
1443 
1444 static int ext4_drop_inode(struct inode *inode)
1445 {
1446 	int drop = generic_drop_inode(inode);
1447 
1448 	if (!drop)
1449 		drop = fscrypt_drop_inode(inode);
1450 
1451 	trace_ext4_drop_inode(inode, drop);
1452 	return drop;
1453 }
1454 
1455 static void ext4_free_in_core_inode(struct inode *inode)
1456 {
1457 	fscrypt_free_inode(inode);
1458 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1459 		pr_warn("%s: inode %ld still in fc list",
1460 			__func__, inode->i_ino);
1461 	}
1462 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1463 }
1464 
1465 static void ext4_destroy_inode(struct inode *inode)
1466 {
1467 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1468 		ext4_msg(inode->i_sb, KERN_ERR,
1469 			 "Inode %lu (%p): orphan list check failed!",
1470 			 inode->i_ino, EXT4_I(inode));
1471 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1472 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1473 				true);
1474 		dump_stack();
1475 	}
1476 
1477 	if (EXT4_I(inode)->i_reserved_data_blocks)
1478 		ext4_msg(inode->i_sb, KERN_ERR,
1479 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1480 			 inode->i_ino, EXT4_I(inode),
1481 			 EXT4_I(inode)->i_reserved_data_blocks);
1482 }
1483 
1484 static void ext4_shutdown(struct super_block *sb)
1485 {
1486        ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
1487 }
1488 
1489 static void init_once(void *foo)
1490 {
1491 	struct ext4_inode_info *ei = foo;
1492 
1493 	INIT_LIST_HEAD(&ei->i_orphan);
1494 	init_rwsem(&ei->xattr_sem);
1495 	init_rwsem(&ei->i_data_sem);
1496 	inode_init_once(&ei->vfs_inode);
1497 	ext4_fc_init_inode(&ei->vfs_inode);
1498 }
1499 
1500 static int __init init_inodecache(void)
1501 {
1502 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1503 				sizeof(struct ext4_inode_info), 0,
1504 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1505 					SLAB_ACCOUNT),
1506 				offsetof(struct ext4_inode_info, i_data),
1507 				sizeof_field(struct ext4_inode_info, i_data),
1508 				init_once);
1509 	if (ext4_inode_cachep == NULL)
1510 		return -ENOMEM;
1511 	return 0;
1512 }
1513 
1514 static void destroy_inodecache(void)
1515 {
1516 	/*
1517 	 * Make sure all delayed rcu free inodes are flushed before we
1518 	 * destroy cache.
1519 	 */
1520 	rcu_barrier();
1521 	kmem_cache_destroy(ext4_inode_cachep);
1522 }
1523 
1524 void ext4_clear_inode(struct inode *inode)
1525 {
1526 	ext4_fc_del(inode);
1527 	invalidate_inode_buffers(inode);
1528 	clear_inode(inode);
1529 	ext4_discard_preallocations(inode, 0);
1530 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1531 	dquot_drop(inode);
1532 	if (EXT4_I(inode)->jinode) {
1533 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1534 					       EXT4_I(inode)->jinode);
1535 		jbd2_free_inode(EXT4_I(inode)->jinode);
1536 		EXT4_I(inode)->jinode = NULL;
1537 	}
1538 	fscrypt_put_encryption_info(inode);
1539 	fsverity_cleanup_inode(inode);
1540 }
1541 
1542 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1543 					u64 ino, u32 generation)
1544 {
1545 	struct inode *inode;
1546 
1547 	/*
1548 	 * Currently we don't know the generation for parent directory, so
1549 	 * a generation of 0 means "accept any"
1550 	 */
1551 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1552 	if (IS_ERR(inode))
1553 		return ERR_CAST(inode);
1554 	if (generation && inode->i_generation != generation) {
1555 		iput(inode);
1556 		return ERR_PTR(-ESTALE);
1557 	}
1558 
1559 	return inode;
1560 }
1561 
1562 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1563 					int fh_len, int fh_type)
1564 {
1565 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1566 				    ext4_nfs_get_inode);
1567 }
1568 
1569 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1570 					int fh_len, int fh_type)
1571 {
1572 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1573 				    ext4_nfs_get_inode);
1574 }
1575 
1576 static int ext4_nfs_commit_metadata(struct inode *inode)
1577 {
1578 	struct writeback_control wbc = {
1579 		.sync_mode = WB_SYNC_ALL
1580 	};
1581 
1582 	trace_ext4_nfs_commit_metadata(inode);
1583 	return ext4_write_inode(inode, &wbc);
1584 }
1585 
1586 #ifdef CONFIG_QUOTA
1587 static const char * const quotatypes[] = INITQFNAMES;
1588 #define QTYPE2NAME(t) (quotatypes[t])
1589 
1590 static int ext4_write_dquot(struct dquot *dquot);
1591 static int ext4_acquire_dquot(struct dquot *dquot);
1592 static int ext4_release_dquot(struct dquot *dquot);
1593 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1594 static int ext4_write_info(struct super_block *sb, int type);
1595 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1596 			 const struct path *path);
1597 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1598 			       size_t len, loff_t off);
1599 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1600 				const char *data, size_t len, loff_t off);
1601 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1602 			     unsigned int flags);
1603 
1604 static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
1605 {
1606 	return EXT4_I(inode)->i_dquot;
1607 }
1608 
1609 static const struct dquot_operations ext4_quota_operations = {
1610 	.get_reserved_space	= ext4_get_reserved_space,
1611 	.write_dquot		= ext4_write_dquot,
1612 	.acquire_dquot		= ext4_acquire_dquot,
1613 	.release_dquot		= ext4_release_dquot,
1614 	.mark_dirty		= ext4_mark_dquot_dirty,
1615 	.write_info		= ext4_write_info,
1616 	.alloc_dquot		= dquot_alloc,
1617 	.destroy_dquot		= dquot_destroy,
1618 	.get_projid		= ext4_get_projid,
1619 	.get_inode_usage	= ext4_get_inode_usage,
1620 	.get_next_id		= dquot_get_next_id,
1621 };
1622 
1623 static const struct quotactl_ops ext4_qctl_operations = {
1624 	.quota_on	= ext4_quota_on,
1625 	.quota_off	= ext4_quota_off,
1626 	.quota_sync	= dquot_quota_sync,
1627 	.get_state	= dquot_get_state,
1628 	.set_info	= dquot_set_dqinfo,
1629 	.get_dqblk	= dquot_get_dqblk,
1630 	.set_dqblk	= dquot_set_dqblk,
1631 	.get_nextdqblk	= dquot_get_next_dqblk,
1632 };
1633 #endif
1634 
1635 static const struct super_operations ext4_sops = {
1636 	.alloc_inode	= ext4_alloc_inode,
1637 	.free_inode	= ext4_free_in_core_inode,
1638 	.destroy_inode	= ext4_destroy_inode,
1639 	.write_inode	= ext4_write_inode,
1640 	.dirty_inode	= ext4_dirty_inode,
1641 	.drop_inode	= ext4_drop_inode,
1642 	.evict_inode	= ext4_evict_inode,
1643 	.put_super	= ext4_put_super,
1644 	.sync_fs	= ext4_sync_fs,
1645 	.freeze_fs	= ext4_freeze,
1646 	.unfreeze_fs	= ext4_unfreeze,
1647 	.statfs		= ext4_statfs,
1648 	.show_options	= ext4_show_options,
1649 	.shutdown	= ext4_shutdown,
1650 #ifdef CONFIG_QUOTA
1651 	.quota_read	= ext4_quota_read,
1652 	.quota_write	= ext4_quota_write,
1653 	.get_dquots	= ext4_get_dquots,
1654 #endif
1655 };
1656 
1657 static const struct export_operations ext4_export_ops = {
1658 	.fh_to_dentry = ext4_fh_to_dentry,
1659 	.fh_to_parent = ext4_fh_to_parent,
1660 	.get_parent = ext4_get_parent,
1661 	.commit_metadata = ext4_nfs_commit_metadata,
1662 };
1663 
1664 enum {
1665 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1666 	Opt_resgid, Opt_resuid, Opt_sb,
1667 	Opt_nouid32, Opt_debug, Opt_removed,
1668 	Opt_user_xattr, Opt_acl,
1669 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1670 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1671 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1672 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1673 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1674 	Opt_inlinecrypt,
1675 	Opt_usrjquota, Opt_grpjquota, Opt_quota,
1676 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1677 	Opt_usrquota, Opt_grpquota, Opt_prjquota,
1678 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1679 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1680 	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1681 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1682 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1683 	Opt_dioread_nolock, Opt_dioread_lock,
1684 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1685 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1686 	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1687 	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1688 #ifdef CONFIG_EXT4_DEBUG
1689 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1690 #endif
1691 };
1692 
1693 static const struct constant_table ext4_param_errors[] = {
1694 	{"continue",	EXT4_MOUNT_ERRORS_CONT},
1695 	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
1696 	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
1697 	{}
1698 };
1699 
1700 static const struct constant_table ext4_param_data[] = {
1701 	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
1702 	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
1703 	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
1704 	{}
1705 };
1706 
1707 static const struct constant_table ext4_param_data_err[] = {
1708 	{"abort",	Opt_data_err_abort},
1709 	{"ignore",	Opt_data_err_ignore},
1710 	{}
1711 };
1712 
1713 static const struct constant_table ext4_param_jqfmt[] = {
1714 	{"vfsold",	QFMT_VFS_OLD},
1715 	{"vfsv0",	QFMT_VFS_V0},
1716 	{"vfsv1",	QFMT_VFS_V1},
1717 	{}
1718 };
1719 
1720 static const struct constant_table ext4_param_dax[] = {
1721 	{"always",	Opt_dax_always},
1722 	{"inode",	Opt_dax_inode},
1723 	{"never",	Opt_dax_never},
1724 	{}
1725 };
1726 
1727 /* String parameter that allows empty argument */
1728 #define fsparam_string_empty(NAME, OPT) \
1729 	__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1730 
1731 /*
1732  * Mount option specification
1733  * We don't use fsparam_flag_no because of the way we set the
1734  * options and the way we show them in _ext4_show_options(). To
1735  * keep the changes to a minimum, let's keep the negative options
1736  * separate for now.
1737  */
1738 static const struct fs_parameter_spec ext4_param_specs[] = {
1739 	fsparam_flag	("bsddf",		Opt_bsd_df),
1740 	fsparam_flag	("minixdf",		Opt_minix_df),
1741 	fsparam_flag	("grpid",		Opt_grpid),
1742 	fsparam_flag	("bsdgroups",		Opt_grpid),
1743 	fsparam_flag	("nogrpid",		Opt_nogrpid),
1744 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
1745 	fsparam_u32	("resgid",		Opt_resgid),
1746 	fsparam_u32	("resuid",		Opt_resuid),
1747 	fsparam_u32	("sb",			Opt_sb),
1748 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
1749 	fsparam_flag	("nouid32",		Opt_nouid32),
1750 	fsparam_flag	("debug",		Opt_debug),
1751 	fsparam_flag	("oldalloc",		Opt_removed),
1752 	fsparam_flag	("orlov",		Opt_removed),
1753 	fsparam_flag	("user_xattr",		Opt_user_xattr),
1754 	fsparam_flag	("acl",			Opt_acl),
1755 	fsparam_flag	("norecovery",		Opt_noload),
1756 	fsparam_flag	("noload",		Opt_noload),
1757 	fsparam_flag	("bh",			Opt_removed),
1758 	fsparam_flag	("nobh",		Opt_removed),
1759 	fsparam_u32	("commit",		Opt_commit),
1760 	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
1761 	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
1762 	fsparam_u32	("journal_dev",		Opt_journal_dev),
1763 	fsparam_bdev	("journal_path",	Opt_journal_path),
1764 	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
1765 	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
1766 	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
1767 	fsparam_flag	("abort",		Opt_abort),
1768 	fsparam_enum	("data",		Opt_data, ext4_param_data),
1769 	fsparam_enum	("data_err",		Opt_data_err,
1770 						ext4_param_data_err),
1771 	fsparam_string_empty
1772 			("usrjquota",		Opt_usrjquota),
1773 	fsparam_string_empty
1774 			("grpjquota",		Opt_grpjquota),
1775 	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
1776 	fsparam_flag	("grpquota",		Opt_grpquota),
1777 	fsparam_flag	("quota",		Opt_quota),
1778 	fsparam_flag	("noquota",		Opt_noquota),
1779 	fsparam_flag	("usrquota",		Opt_usrquota),
1780 	fsparam_flag	("prjquota",		Opt_prjquota),
1781 	fsparam_flag	("barrier",		Opt_barrier),
1782 	fsparam_u32	("barrier",		Opt_barrier),
1783 	fsparam_flag	("nobarrier",		Opt_nobarrier),
1784 	fsparam_flag	("i_version",		Opt_removed),
1785 	fsparam_flag	("dax",			Opt_dax),
1786 	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
1787 	fsparam_u32	("stripe",		Opt_stripe),
1788 	fsparam_flag	("delalloc",		Opt_delalloc),
1789 	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
1790 	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
1791 	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
1792 	fsparam_u32	("debug_want_extra_isize",
1793 						Opt_debug_want_extra_isize),
1794 	fsparam_flag	("mblk_io_submit",	Opt_removed),
1795 	fsparam_flag	("nomblk_io_submit",	Opt_removed),
1796 	fsparam_flag	("block_validity",	Opt_block_validity),
1797 	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
1798 	fsparam_u32	("inode_readahead_blks",
1799 						Opt_inode_readahead_blks),
1800 	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
1801 	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
1802 	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
1803 	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
1804 	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
1805 	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
1806 	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
1807 	fsparam_flag	("discard",		Opt_discard),
1808 	fsparam_flag	("nodiscard",		Opt_nodiscard),
1809 	fsparam_u32	("init_itable",		Opt_init_itable),
1810 	fsparam_flag	("init_itable",		Opt_init_itable),
1811 	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
1812 #ifdef CONFIG_EXT4_DEBUG
1813 	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
1814 	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
1815 #endif
1816 	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
1817 	fsparam_flag	("test_dummy_encryption",
1818 						Opt_test_dummy_encryption),
1819 	fsparam_string	("test_dummy_encryption",
1820 						Opt_test_dummy_encryption),
1821 	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
1822 	fsparam_flag	("nombcache",		Opt_nombcache),
1823 	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
1824 	fsparam_flag	("prefetch_block_bitmaps",
1825 						Opt_removed),
1826 	fsparam_flag	("no_prefetch_block_bitmaps",
1827 						Opt_no_prefetch_block_bitmaps),
1828 	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
1829 	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
1830 	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
1831 	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
1832 	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
1833 	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
1834 	{}
1835 };
1836 
1837 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1838 
1839 #define MOPT_SET	0x0001
1840 #define MOPT_CLEAR	0x0002
1841 #define MOPT_NOSUPPORT	0x0004
1842 #define MOPT_EXPLICIT	0x0008
1843 #ifdef CONFIG_QUOTA
1844 #define MOPT_Q		0
1845 #define MOPT_QFMT	0x0010
1846 #else
1847 #define MOPT_Q		MOPT_NOSUPPORT
1848 #define MOPT_QFMT	MOPT_NOSUPPORT
1849 #endif
1850 #define MOPT_NO_EXT2	0x0020
1851 #define MOPT_NO_EXT3	0x0040
1852 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1853 #define MOPT_SKIP	0x0080
1854 #define	MOPT_2		0x0100
1855 
1856 static const struct mount_opts {
1857 	int	token;
1858 	int	mount_opt;
1859 	int	flags;
1860 } ext4_mount_opts[] = {
1861 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1862 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1863 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1864 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1865 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1866 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1867 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1868 	 MOPT_EXT4_ONLY | MOPT_SET},
1869 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1870 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1871 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1872 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1873 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1874 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1875 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1876 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1877 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1878 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1879 	{Opt_commit, 0, MOPT_NO_EXT2},
1880 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1881 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1882 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1883 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1884 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1885 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1886 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1887 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1888 	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1889 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1890 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1891 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1892 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1893 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1894 	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
1895 	{Opt_journal_dev, 0, MOPT_NO_EXT2},
1896 	{Opt_journal_path, 0, MOPT_NO_EXT2},
1897 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1898 	{Opt_data, 0, MOPT_NO_EXT2},
1899 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1900 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1901 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1902 #else
1903 	{Opt_acl, 0, MOPT_NOSUPPORT},
1904 #endif
1905 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1906 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1907 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1908 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1909 							MOPT_SET | MOPT_Q},
1910 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1911 							MOPT_SET | MOPT_Q},
1912 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1913 							MOPT_SET | MOPT_Q},
1914 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1915 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1916 							MOPT_CLEAR | MOPT_Q},
1917 	{Opt_usrjquota, 0, MOPT_Q},
1918 	{Opt_grpjquota, 0, MOPT_Q},
1919 	{Opt_jqfmt, 0, MOPT_QFMT},
1920 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1921 	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1922 	 MOPT_SET},
1923 #ifdef CONFIG_EXT4_DEBUG
1924 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1925 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1926 #endif
1927 	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
1928 	{Opt_err, 0, 0}
1929 };
1930 
1931 #if IS_ENABLED(CONFIG_UNICODE)
1932 static const struct ext4_sb_encodings {
1933 	__u16 magic;
1934 	char *name;
1935 	unsigned int version;
1936 } ext4_sb_encoding_map[] = {
1937 	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1938 };
1939 
1940 static const struct ext4_sb_encodings *
1941 ext4_sb_read_encoding(const struct ext4_super_block *es)
1942 {
1943 	__u16 magic = le16_to_cpu(es->s_encoding);
1944 	int i;
1945 
1946 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1947 		if (magic == ext4_sb_encoding_map[i].magic)
1948 			return &ext4_sb_encoding_map[i];
1949 
1950 	return NULL;
1951 }
1952 #endif
1953 
1954 #define EXT4_SPEC_JQUOTA			(1 <<  0)
1955 #define EXT4_SPEC_JQFMT				(1 <<  1)
1956 #define EXT4_SPEC_DATAJ				(1 <<  2)
1957 #define EXT4_SPEC_SB_BLOCK			(1 <<  3)
1958 #define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
1959 #define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
1960 #define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
1961 #define EXT4_SPEC_s_max_batch_time		(1 <<  8)
1962 #define EXT4_SPEC_s_min_batch_time		(1 <<  9)
1963 #define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
1964 #define EXT4_SPEC_s_li_wait_mult		(1 << 11)
1965 #define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
1966 #define EXT4_SPEC_s_stripe			(1 << 13)
1967 #define EXT4_SPEC_s_resuid			(1 << 14)
1968 #define EXT4_SPEC_s_resgid			(1 << 15)
1969 #define EXT4_SPEC_s_commit_interval		(1 << 16)
1970 #define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
1971 #define EXT4_SPEC_s_sb_block			(1 << 18)
1972 #define EXT4_SPEC_mb_optimize_scan		(1 << 19)
1973 
1974 struct ext4_fs_context {
1975 	char		*s_qf_names[EXT4_MAXQUOTAS];
1976 	struct fscrypt_dummy_policy dummy_enc_policy;
1977 	int		s_jquota_fmt;	/* Format of quota to use */
1978 #ifdef CONFIG_EXT4_DEBUG
1979 	int s_fc_debug_max_replay;
1980 #endif
1981 	unsigned short	qname_spec;
1982 	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
1983 	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
1984 	unsigned long	journal_devnum;
1985 	unsigned long	s_commit_interval;
1986 	unsigned long	s_stripe;
1987 	unsigned int	s_inode_readahead_blks;
1988 	unsigned int	s_want_extra_isize;
1989 	unsigned int	s_li_wait_mult;
1990 	unsigned int	s_max_dir_size_kb;
1991 	unsigned int	journal_ioprio;
1992 	unsigned int	vals_s_mount_opt;
1993 	unsigned int	mask_s_mount_opt;
1994 	unsigned int	vals_s_mount_opt2;
1995 	unsigned int	mask_s_mount_opt2;
1996 	unsigned int	opt_flags;	/* MOPT flags */
1997 	unsigned int	spec;
1998 	u32		s_max_batch_time;
1999 	u32		s_min_batch_time;
2000 	kuid_t		s_resuid;
2001 	kgid_t		s_resgid;
2002 	ext4_fsblk_t	s_sb_block;
2003 };
2004 
2005 static void ext4_fc_free(struct fs_context *fc)
2006 {
2007 	struct ext4_fs_context *ctx = fc->fs_private;
2008 	int i;
2009 
2010 	if (!ctx)
2011 		return;
2012 
2013 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
2014 		kfree(ctx->s_qf_names[i]);
2015 
2016 	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
2017 	kfree(ctx);
2018 }
2019 
2020 int ext4_init_fs_context(struct fs_context *fc)
2021 {
2022 	struct ext4_fs_context *ctx;
2023 
2024 	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2025 	if (!ctx)
2026 		return -ENOMEM;
2027 
2028 	fc->fs_private = ctx;
2029 	fc->ops = &ext4_context_ops;
2030 
2031 	return 0;
2032 }
2033 
2034 #ifdef CONFIG_QUOTA
2035 /*
2036  * Note the name of the specified quota file.
2037  */
2038 static int note_qf_name(struct fs_context *fc, int qtype,
2039 		       struct fs_parameter *param)
2040 {
2041 	struct ext4_fs_context *ctx = fc->fs_private;
2042 	char *qname;
2043 
2044 	if (param->size < 1) {
2045 		ext4_msg(NULL, KERN_ERR, "Missing quota name");
2046 		return -EINVAL;
2047 	}
2048 	if (strchr(param->string, '/')) {
2049 		ext4_msg(NULL, KERN_ERR,
2050 			 "quotafile must be on filesystem root");
2051 		return -EINVAL;
2052 	}
2053 	if (ctx->s_qf_names[qtype]) {
2054 		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2055 			ext4_msg(NULL, KERN_ERR,
2056 				 "%s quota file already specified",
2057 				 QTYPE2NAME(qtype));
2058 			return -EINVAL;
2059 		}
2060 		return 0;
2061 	}
2062 
2063 	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2064 	if (!qname) {
2065 		ext4_msg(NULL, KERN_ERR,
2066 			 "Not enough memory for storing quotafile name");
2067 		return -ENOMEM;
2068 	}
2069 	ctx->s_qf_names[qtype] = qname;
2070 	ctx->qname_spec |= 1 << qtype;
2071 	ctx->spec |= EXT4_SPEC_JQUOTA;
2072 	return 0;
2073 }
2074 
2075 /*
2076  * Clear the name of the specified quota file.
2077  */
2078 static int unnote_qf_name(struct fs_context *fc, int qtype)
2079 {
2080 	struct ext4_fs_context *ctx = fc->fs_private;
2081 
2082 	if (ctx->s_qf_names[qtype])
2083 		kfree(ctx->s_qf_names[qtype]);
2084 
2085 	ctx->s_qf_names[qtype] = NULL;
2086 	ctx->qname_spec |= 1 << qtype;
2087 	ctx->spec |= EXT4_SPEC_JQUOTA;
2088 	return 0;
2089 }
2090 #endif
2091 
2092 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2093 					    struct ext4_fs_context *ctx)
2094 {
2095 	int err;
2096 
2097 	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2098 		ext4_msg(NULL, KERN_WARNING,
2099 			 "test_dummy_encryption option not supported");
2100 		return -EINVAL;
2101 	}
2102 	err = fscrypt_parse_test_dummy_encryption(param,
2103 						  &ctx->dummy_enc_policy);
2104 	if (err == -EINVAL) {
2105 		ext4_msg(NULL, KERN_WARNING,
2106 			 "Value of option \"%s\" is unrecognized", param->key);
2107 	} else if (err == -EEXIST) {
2108 		ext4_msg(NULL, KERN_WARNING,
2109 			 "Conflicting test_dummy_encryption options");
2110 		return -EINVAL;
2111 	}
2112 	return err;
2113 }
2114 
2115 #define EXT4_SET_CTX(name)						\
2116 static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
2117 				  unsigned long flag)			\
2118 {									\
2119 	ctx->mask_s_##name |= flag;					\
2120 	ctx->vals_s_##name |= flag;					\
2121 }
2122 
2123 #define EXT4_CLEAR_CTX(name)						\
2124 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
2125 				    unsigned long flag)			\
2126 {									\
2127 	ctx->mask_s_##name |= flag;					\
2128 	ctx->vals_s_##name &= ~flag;					\
2129 }
2130 
2131 #define EXT4_TEST_CTX(name)						\
2132 static inline unsigned long						\
2133 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
2134 {									\
2135 	return (ctx->vals_s_##name & flag);				\
2136 }
2137 
2138 EXT4_SET_CTX(flags); /* set only */
2139 EXT4_SET_CTX(mount_opt);
2140 EXT4_CLEAR_CTX(mount_opt);
2141 EXT4_TEST_CTX(mount_opt);
2142 EXT4_SET_CTX(mount_opt2);
2143 EXT4_CLEAR_CTX(mount_opt2);
2144 EXT4_TEST_CTX(mount_opt2);
2145 
2146 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2147 {
2148 	struct ext4_fs_context *ctx = fc->fs_private;
2149 	struct fs_parse_result result;
2150 	const struct mount_opts *m;
2151 	int is_remount;
2152 	kuid_t uid;
2153 	kgid_t gid;
2154 	int token;
2155 
2156 	token = fs_parse(fc, ext4_param_specs, param, &result);
2157 	if (token < 0)
2158 		return token;
2159 	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2160 
2161 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2162 		if (token == m->token)
2163 			break;
2164 
2165 	ctx->opt_flags |= m->flags;
2166 
2167 	if (m->flags & MOPT_EXPLICIT) {
2168 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2169 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2170 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2171 			ctx_set_mount_opt2(ctx,
2172 				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2173 		} else
2174 			return -EINVAL;
2175 	}
2176 
2177 	if (m->flags & MOPT_NOSUPPORT) {
2178 		ext4_msg(NULL, KERN_ERR, "%s option not supported",
2179 			 param->key);
2180 		return 0;
2181 	}
2182 
2183 	switch (token) {
2184 #ifdef CONFIG_QUOTA
2185 	case Opt_usrjquota:
2186 		if (!*param->string)
2187 			return unnote_qf_name(fc, USRQUOTA);
2188 		else
2189 			return note_qf_name(fc, USRQUOTA, param);
2190 	case Opt_grpjquota:
2191 		if (!*param->string)
2192 			return unnote_qf_name(fc, GRPQUOTA);
2193 		else
2194 			return note_qf_name(fc, GRPQUOTA, param);
2195 #endif
2196 	case Opt_sb:
2197 		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2198 			ext4_msg(NULL, KERN_WARNING,
2199 				 "Ignoring %s option on remount", param->key);
2200 		} else {
2201 			ctx->s_sb_block = result.uint_32;
2202 			ctx->spec |= EXT4_SPEC_s_sb_block;
2203 		}
2204 		return 0;
2205 	case Opt_removed:
2206 		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2207 			 param->key);
2208 		return 0;
2209 	case Opt_inlinecrypt:
2210 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2211 		ctx_set_flags(ctx, SB_INLINECRYPT);
2212 #else
2213 		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2214 #endif
2215 		return 0;
2216 	case Opt_errors:
2217 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2218 		ctx_set_mount_opt(ctx, result.uint_32);
2219 		return 0;
2220 #ifdef CONFIG_QUOTA
2221 	case Opt_jqfmt:
2222 		ctx->s_jquota_fmt = result.uint_32;
2223 		ctx->spec |= EXT4_SPEC_JQFMT;
2224 		return 0;
2225 #endif
2226 	case Opt_data:
2227 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2228 		ctx_set_mount_opt(ctx, result.uint_32);
2229 		ctx->spec |= EXT4_SPEC_DATAJ;
2230 		return 0;
2231 	case Opt_commit:
2232 		if (result.uint_32 == 0)
2233 			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
2234 		else if (result.uint_32 > INT_MAX / HZ) {
2235 			ext4_msg(NULL, KERN_ERR,
2236 				 "Invalid commit interval %d, "
2237 				 "must be smaller than %d",
2238 				 result.uint_32, INT_MAX / HZ);
2239 			return -EINVAL;
2240 		}
2241 		ctx->s_commit_interval = HZ * result.uint_32;
2242 		ctx->spec |= EXT4_SPEC_s_commit_interval;
2243 		return 0;
2244 	case Opt_debug_want_extra_isize:
2245 		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2246 			ext4_msg(NULL, KERN_ERR,
2247 				 "Invalid want_extra_isize %d", result.uint_32);
2248 			return -EINVAL;
2249 		}
2250 		ctx->s_want_extra_isize = result.uint_32;
2251 		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2252 		return 0;
2253 	case Opt_max_batch_time:
2254 		ctx->s_max_batch_time = result.uint_32;
2255 		ctx->spec |= EXT4_SPEC_s_max_batch_time;
2256 		return 0;
2257 	case Opt_min_batch_time:
2258 		ctx->s_min_batch_time = result.uint_32;
2259 		ctx->spec |= EXT4_SPEC_s_min_batch_time;
2260 		return 0;
2261 	case Opt_inode_readahead_blks:
2262 		if (result.uint_32 &&
2263 		    (result.uint_32 > (1 << 30) ||
2264 		     !is_power_of_2(result.uint_32))) {
2265 			ext4_msg(NULL, KERN_ERR,
2266 				 "EXT4-fs: inode_readahead_blks must be "
2267 				 "0 or a power of 2 smaller than 2^31");
2268 			return -EINVAL;
2269 		}
2270 		ctx->s_inode_readahead_blks = result.uint_32;
2271 		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2272 		return 0;
2273 	case Opt_init_itable:
2274 		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2275 		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2276 		if (param->type == fs_value_is_string)
2277 			ctx->s_li_wait_mult = result.uint_32;
2278 		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2279 		return 0;
2280 	case Opt_max_dir_size_kb:
2281 		ctx->s_max_dir_size_kb = result.uint_32;
2282 		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2283 		return 0;
2284 #ifdef CONFIG_EXT4_DEBUG
2285 	case Opt_fc_debug_max_replay:
2286 		ctx->s_fc_debug_max_replay = result.uint_32;
2287 		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2288 		return 0;
2289 #endif
2290 	case Opt_stripe:
2291 		ctx->s_stripe = result.uint_32;
2292 		ctx->spec |= EXT4_SPEC_s_stripe;
2293 		return 0;
2294 	case Opt_resuid:
2295 		uid = make_kuid(current_user_ns(), result.uint_32);
2296 		if (!uid_valid(uid)) {
2297 			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2298 				 result.uint_32);
2299 			return -EINVAL;
2300 		}
2301 		ctx->s_resuid = uid;
2302 		ctx->spec |= EXT4_SPEC_s_resuid;
2303 		return 0;
2304 	case Opt_resgid:
2305 		gid = make_kgid(current_user_ns(), result.uint_32);
2306 		if (!gid_valid(gid)) {
2307 			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2308 				 result.uint_32);
2309 			return -EINVAL;
2310 		}
2311 		ctx->s_resgid = gid;
2312 		ctx->spec |= EXT4_SPEC_s_resgid;
2313 		return 0;
2314 	case Opt_journal_dev:
2315 		if (is_remount) {
2316 			ext4_msg(NULL, KERN_ERR,
2317 				 "Cannot specify journal on remount");
2318 			return -EINVAL;
2319 		}
2320 		ctx->journal_devnum = result.uint_32;
2321 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2322 		return 0;
2323 	case Opt_journal_path:
2324 	{
2325 		struct inode *journal_inode;
2326 		struct path path;
2327 		int error;
2328 
2329 		if (is_remount) {
2330 			ext4_msg(NULL, KERN_ERR,
2331 				 "Cannot specify journal on remount");
2332 			return -EINVAL;
2333 		}
2334 
2335 		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
2336 		if (error) {
2337 			ext4_msg(NULL, KERN_ERR, "error: could not find "
2338 				 "journal device path");
2339 			return -EINVAL;
2340 		}
2341 
2342 		journal_inode = d_inode(path.dentry);
2343 		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2344 		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2345 		path_put(&path);
2346 		return 0;
2347 	}
2348 	case Opt_journal_ioprio:
2349 		if (result.uint_32 > 7) {
2350 			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2351 				 " (must be 0-7)");
2352 			return -EINVAL;
2353 		}
2354 		ctx->journal_ioprio =
2355 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2356 		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2357 		return 0;
2358 	case Opt_test_dummy_encryption:
2359 		return ext4_parse_test_dummy_encryption(param, ctx);
2360 	case Opt_dax:
2361 	case Opt_dax_type:
2362 #ifdef CONFIG_FS_DAX
2363 	{
2364 		int type = (token == Opt_dax) ?
2365 			   Opt_dax : result.uint_32;
2366 
2367 		switch (type) {
2368 		case Opt_dax:
2369 		case Opt_dax_always:
2370 			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2371 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2372 			break;
2373 		case Opt_dax_never:
2374 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2375 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2376 			break;
2377 		case Opt_dax_inode:
2378 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2379 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2380 			/* Strictly for printing options */
2381 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2382 			break;
2383 		}
2384 		return 0;
2385 	}
2386 #else
2387 		ext4_msg(NULL, KERN_INFO, "dax option not supported");
2388 		return -EINVAL;
2389 #endif
2390 	case Opt_data_err:
2391 		if (result.uint_32 == Opt_data_err_abort)
2392 			ctx_set_mount_opt(ctx, m->mount_opt);
2393 		else if (result.uint_32 == Opt_data_err_ignore)
2394 			ctx_clear_mount_opt(ctx, m->mount_opt);
2395 		return 0;
2396 	case Opt_mb_optimize_scan:
2397 		if (result.int_32 == 1) {
2398 			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2399 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2400 		} else if (result.int_32 == 0) {
2401 			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2402 			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2403 		} else {
2404 			ext4_msg(NULL, KERN_WARNING,
2405 				 "mb_optimize_scan should be set to 0 or 1.");
2406 			return -EINVAL;
2407 		}
2408 		return 0;
2409 	}
2410 
2411 	/*
2412 	 * At this point we should only be getting options requiring MOPT_SET,
2413 	 * or MOPT_CLEAR. Anything else is a bug
2414 	 */
2415 	if (m->token == Opt_err) {
2416 		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2417 			 param->key);
2418 		WARN_ON(1);
2419 		return -EINVAL;
2420 	}
2421 
2422 	else {
2423 		unsigned int set = 0;
2424 
2425 		if ((param->type == fs_value_is_flag) ||
2426 		    result.uint_32 > 0)
2427 			set = 1;
2428 
2429 		if (m->flags & MOPT_CLEAR)
2430 			set = !set;
2431 		else if (unlikely(!(m->flags & MOPT_SET))) {
2432 			ext4_msg(NULL, KERN_WARNING,
2433 				 "buggy handling of option %s",
2434 				 param->key);
2435 			WARN_ON(1);
2436 			return -EINVAL;
2437 		}
2438 		if (m->flags & MOPT_2) {
2439 			if (set != 0)
2440 				ctx_set_mount_opt2(ctx, m->mount_opt);
2441 			else
2442 				ctx_clear_mount_opt2(ctx, m->mount_opt);
2443 		} else {
2444 			if (set != 0)
2445 				ctx_set_mount_opt(ctx, m->mount_opt);
2446 			else
2447 				ctx_clear_mount_opt(ctx, m->mount_opt);
2448 		}
2449 	}
2450 
2451 	return 0;
2452 }
2453 
2454 static int parse_options(struct fs_context *fc, char *options)
2455 {
2456 	struct fs_parameter param;
2457 	int ret;
2458 	char *key;
2459 
2460 	if (!options)
2461 		return 0;
2462 
2463 	while ((key = strsep(&options, ",")) != NULL) {
2464 		if (*key) {
2465 			size_t v_len = 0;
2466 			char *value = strchr(key, '=');
2467 
2468 			param.type = fs_value_is_flag;
2469 			param.string = NULL;
2470 
2471 			if (value) {
2472 				if (value == key)
2473 					continue;
2474 
2475 				*value++ = 0;
2476 				v_len = strlen(value);
2477 				param.string = kmemdup_nul(value, v_len,
2478 							   GFP_KERNEL);
2479 				if (!param.string)
2480 					return -ENOMEM;
2481 				param.type = fs_value_is_string;
2482 			}
2483 
2484 			param.key = key;
2485 			param.size = v_len;
2486 
2487 			ret = ext4_parse_param(fc, &param);
2488 			if (param.string)
2489 				kfree(param.string);
2490 			if (ret < 0)
2491 				return ret;
2492 		}
2493 	}
2494 
2495 	ret = ext4_validate_options(fc);
2496 	if (ret < 0)
2497 		return ret;
2498 
2499 	return 0;
2500 }
2501 
2502 static int parse_apply_sb_mount_options(struct super_block *sb,
2503 					struct ext4_fs_context *m_ctx)
2504 {
2505 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2506 	char *s_mount_opts = NULL;
2507 	struct ext4_fs_context *s_ctx = NULL;
2508 	struct fs_context *fc = NULL;
2509 	int ret = -ENOMEM;
2510 
2511 	if (!sbi->s_es->s_mount_opts[0])
2512 		return 0;
2513 
2514 	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2515 				sizeof(sbi->s_es->s_mount_opts),
2516 				GFP_KERNEL);
2517 	if (!s_mount_opts)
2518 		return ret;
2519 
2520 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2521 	if (!fc)
2522 		goto out_free;
2523 
2524 	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2525 	if (!s_ctx)
2526 		goto out_free;
2527 
2528 	fc->fs_private = s_ctx;
2529 	fc->s_fs_info = sbi;
2530 
2531 	ret = parse_options(fc, s_mount_opts);
2532 	if (ret < 0)
2533 		goto parse_failed;
2534 
2535 	ret = ext4_check_opt_consistency(fc, sb);
2536 	if (ret < 0) {
2537 parse_failed:
2538 		ext4_msg(sb, KERN_WARNING,
2539 			 "failed to parse options in superblock: %s",
2540 			 s_mount_opts);
2541 		ret = 0;
2542 		goto out_free;
2543 	}
2544 
2545 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2546 		m_ctx->journal_devnum = s_ctx->journal_devnum;
2547 	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2548 		m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2549 
2550 	ext4_apply_options(fc, sb);
2551 	ret = 0;
2552 
2553 out_free:
2554 	if (fc) {
2555 		ext4_fc_free(fc);
2556 		kfree(fc);
2557 	}
2558 	kfree(s_mount_opts);
2559 	return ret;
2560 }
2561 
2562 static void ext4_apply_quota_options(struct fs_context *fc,
2563 				     struct super_block *sb)
2564 {
2565 #ifdef CONFIG_QUOTA
2566 	bool quota_feature = ext4_has_feature_quota(sb);
2567 	struct ext4_fs_context *ctx = fc->fs_private;
2568 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2569 	char *qname;
2570 	int i;
2571 
2572 	if (quota_feature)
2573 		return;
2574 
2575 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2576 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2577 			if (!(ctx->qname_spec & (1 << i)))
2578 				continue;
2579 
2580 			qname = ctx->s_qf_names[i]; /* May be NULL */
2581 			if (qname)
2582 				set_opt(sb, QUOTA);
2583 			ctx->s_qf_names[i] = NULL;
2584 			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2585 						lockdep_is_held(&sb->s_umount));
2586 			if (qname)
2587 				kfree_rcu_mightsleep(qname);
2588 		}
2589 	}
2590 
2591 	if (ctx->spec & EXT4_SPEC_JQFMT)
2592 		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2593 #endif
2594 }
2595 
2596 /*
2597  * Check quota settings consistency.
2598  */
2599 static int ext4_check_quota_consistency(struct fs_context *fc,
2600 					struct super_block *sb)
2601 {
2602 #ifdef CONFIG_QUOTA
2603 	struct ext4_fs_context *ctx = fc->fs_private;
2604 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2605 	bool quota_feature = ext4_has_feature_quota(sb);
2606 	bool quota_loaded = sb_any_quota_loaded(sb);
2607 	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2608 	int quota_flags, i;
2609 
2610 	/*
2611 	 * We do the test below only for project quotas. 'usrquota' and
2612 	 * 'grpquota' mount options are allowed even without quota feature
2613 	 * to support legacy quotas in quota files.
2614 	 */
2615 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2616 	    !ext4_has_feature_project(sb)) {
2617 		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2618 			 "Cannot enable project quota enforcement.");
2619 		return -EINVAL;
2620 	}
2621 
2622 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2623 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2624 	if (quota_loaded &&
2625 	    ctx->mask_s_mount_opt & quota_flags &&
2626 	    !ctx_test_mount_opt(ctx, quota_flags))
2627 		goto err_quota_change;
2628 
2629 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
2630 
2631 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2632 			if (!(ctx->qname_spec & (1 << i)))
2633 				continue;
2634 
2635 			if (quota_loaded &&
2636 			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2637 				goto err_jquota_change;
2638 
2639 			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2640 			    strcmp(get_qf_name(sb, sbi, i),
2641 				   ctx->s_qf_names[i]) != 0)
2642 				goto err_jquota_specified;
2643 		}
2644 
2645 		if (quota_feature) {
2646 			ext4_msg(NULL, KERN_INFO,
2647 				 "Journaled quota options ignored when "
2648 				 "QUOTA feature is enabled");
2649 			return 0;
2650 		}
2651 	}
2652 
2653 	if (ctx->spec & EXT4_SPEC_JQFMT) {
2654 		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2655 			goto err_jquota_change;
2656 		if (quota_feature) {
2657 			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2658 				 "ignored when QUOTA feature is enabled");
2659 			return 0;
2660 		}
2661 	}
2662 
2663 	/* Make sure we don't mix old and new quota format */
2664 	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2665 		       ctx->s_qf_names[USRQUOTA]);
2666 	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2667 		       ctx->s_qf_names[GRPQUOTA]);
2668 
2669 	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2670 		    test_opt(sb, USRQUOTA));
2671 
2672 	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2673 		    test_opt(sb, GRPQUOTA));
2674 
2675 	if (usr_qf_name) {
2676 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2677 		usrquota = false;
2678 	}
2679 	if (grp_qf_name) {
2680 		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2681 		grpquota = false;
2682 	}
2683 
2684 	if (usr_qf_name || grp_qf_name) {
2685 		if (usrquota || grpquota) {
2686 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2687 				 "format mixing");
2688 			return -EINVAL;
2689 		}
2690 
2691 		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2692 			ext4_msg(NULL, KERN_ERR, "journaled quota format "
2693 				 "not specified");
2694 			return -EINVAL;
2695 		}
2696 	}
2697 
2698 	return 0;
2699 
2700 err_quota_change:
2701 	ext4_msg(NULL, KERN_ERR,
2702 		 "Cannot change quota options when quota turned on");
2703 	return -EINVAL;
2704 err_jquota_change:
2705 	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2706 		 "options when quota turned on");
2707 	return -EINVAL;
2708 err_jquota_specified:
2709 	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2710 		 QTYPE2NAME(i));
2711 	return -EINVAL;
2712 #else
2713 	return 0;
2714 #endif
2715 }
2716 
2717 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2718 					    struct super_block *sb)
2719 {
2720 	const struct ext4_fs_context *ctx = fc->fs_private;
2721 	const struct ext4_sb_info *sbi = EXT4_SB(sb);
2722 
2723 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2724 		return 0;
2725 
2726 	if (!ext4_has_feature_encrypt(sb)) {
2727 		ext4_msg(NULL, KERN_WARNING,
2728 			 "test_dummy_encryption requires encrypt feature");
2729 		return -EINVAL;
2730 	}
2731 	/*
2732 	 * This mount option is just for testing, and it's not worthwhile to
2733 	 * implement the extra complexity (e.g. RCU protection) that would be
2734 	 * needed to allow it to be set or changed during remount.  We do allow
2735 	 * it to be specified during remount, but only if there is no change.
2736 	 */
2737 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
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 			 "Can't set or change test_dummy_encryption on remount");
2743 		return -EINVAL;
2744 	}
2745 	/* Also make sure s_mount_opts didn't contain a conflicting value. */
2746 	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2747 		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2748 						 &ctx->dummy_enc_policy))
2749 			return 0;
2750 		ext4_msg(NULL, KERN_WARNING,
2751 			 "Conflicting test_dummy_encryption options");
2752 		return -EINVAL;
2753 	}
2754 	return 0;
2755 }
2756 
2757 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2758 					     struct super_block *sb)
2759 {
2760 	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2761 	    /* if already set, it was already verified to be the same */
2762 	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2763 		return;
2764 	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2765 	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2766 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2767 }
2768 
2769 static int ext4_check_opt_consistency(struct fs_context *fc,
2770 				      struct super_block *sb)
2771 {
2772 	struct ext4_fs_context *ctx = fc->fs_private;
2773 	struct ext4_sb_info *sbi = fc->s_fs_info;
2774 	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2775 	int err;
2776 
2777 	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2778 		ext4_msg(NULL, KERN_ERR,
2779 			 "Mount option(s) incompatible with ext2");
2780 		return -EINVAL;
2781 	}
2782 	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2783 		ext4_msg(NULL, KERN_ERR,
2784 			 "Mount option(s) incompatible with ext3");
2785 		return -EINVAL;
2786 	}
2787 
2788 	if (ctx->s_want_extra_isize >
2789 	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2790 		ext4_msg(NULL, KERN_ERR,
2791 			 "Invalid want_extra_isize %d",
2792 			 ctx->s_want_extra_isize);
2793 		return -EINVAL;
2794 	}
2795 
2796 	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2797 		int blocksize =
2798 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2799 		if (blocksize < PAGE_SIZE)
2800 			ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2801 				 "experimental mount option 'dioread_nolock' "
2802 				 "for blocksize < PAGE_SIZE");
2803 	}
2804 
2805 	err = ext4_check_test_dummy_encryption(fc, sb);
2806 	if (err)
2807 		return err;
2808 
2809 	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2810 		if (!sbi->s_journal) {
2811 			ext4_msg(NULL, KERN_WARNING,
2812 				 "Remounting file system with no journal "
2813 				 "so ignoring journalled data option");
2814 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2815 		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2816 			   test_opt(sb, DATA_FLAGS)) {
2817 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2818 				 "on remount");
2819 			return -EINVAL;
2820 		}
2821 	}
2822 
2823 	if (is_remount) {
2824 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2825 		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2826 			ext4_msg(NULL, KERN_ERR, "can't mount with "
2827 				 "both data=journal and dax");
2828 			return -EINVAL;
2829 		}
2830 
2831 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2832 		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2833 		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2834 fail_dax_change_remount:
2835 			ext4_msg(NULL, KERN_ERR, "can't change "
2836 				 "dax mount option while remounting");
2837 			return -EINVAL;
2838 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2839 			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2840 			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2841 			goto fail_dax_change_remount;
2842 		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2843 			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2844 			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2845 			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2846 			goto fail_dax_change_remount;
2847 		}
2848 	}
2849 
2850 	return ext4_check_quota_consistency(fc, sb);
2851 }
2852 
2853 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2854 {
2855 	struct ext4_fs_context *ctx = fc->fs_private;
2856 	struct ext4_sb_info *sbi = fc->s_fs_info;
2857 
2858 	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2859 	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2860 	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2861 	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2862 	sb->s_flags &= ~ctx->mask_s_flags;
2863 	sb->s_flags |= ctx->vals_s_flags;
2864 
2865 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2866 	APPLY(s_commit_interval);
2867 	APPLY(s_stripe);
2868 	APPLY(s_max_batch_time);
2869 	APPLY(s_min_batch_time);
2870 	APPLY(s_want_extra_isize);
2871 	APPLY(s_inode_readahead_blks);
2872 	APPLY(s_max_dir_size_kb);
2873 	APPLY(s_li_wait_mult);
2874 	APPLY(s_resgid);
2875 	APPLY(s_resuid);
2876 
2877 #ifdef CONFIG_EXT4_DEBUG
2878 	APPLY(s_fc_debug_max_replay);
2879 #endif
2880 
2881 	ext4_apply_quota_options(fc, sb);
2882 	ext4_apply_test_dummy_encryption(ctx, sb);
2883 }
2884 
2885 
2886 static int ext4_validate_options(struct fs_context *fc)
2887 {
2888 #ifdef CONFIG_QUOTA
2889 	struct ext4_fs_context *ctx = fc->fs_private;
2890 	char *usr_qf_name, *grp_qf_name;
2891 
2892 	usr_qf_name = ctx->s_qf_names[USRQUOTA];
2893 	grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2894 
2895 	if (usr_qf_name || grp_qf_name) {
2896 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2897 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2898 
2899 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2900 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2901 
2902 		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2903 		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2904 			ext4_msg(NULL, KERN_ERR, "old and new quota "
2905 				 "format mixing");
2906 			return -EINVAL;
2907 		}
2908 	}
2909 #endif
2910 	return 1;
2911 }
2912 
2913 static inline void ext4_show_quota_options(struct seq_file *seq,
2914 					   struct super_block *sb)
2915 {
2916 #if defined(CONFIG_QUOTA)
2917 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2918 	char *usr_qf_name, *grp_qf_name;
2919 
2920 	if (sbi->s_jquota_fmt) {
2921 		char *fmtname = "";
2922 
2923 		switch (sbi->s_jquota_fmt) {
2924 		case QFMT_VFS_OLD:
2925 			fmtname = "vfsold";
2926 			break;
2927 		case QFMT_VFS_V0:
2928 			fmtname = "vfsv0";
2929 			break;
2930 		case QFMT_VFS_V1:
2931 			fmtname = "vfsv1";
2932 			break;
2933 		}
2934 		seq_printf(seq, ",jqfmt=%s", fmtname);
2935 	}
2936 
2937 	rcu_read_lock();
2938 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2939 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2940 	if (usr_qf_name)
2941 		seq_show_option(seq, "usrjquota", usr_qf_name);
2942 	if (grp_qf_name)
2943 		seq_show_option(seq, "grpjquota", grp_qf_name);
2944 	rcu_read_unlock();
2945 #endif
2946 }
2947 
2948 static const char *token2str(int token)
2949 {
2950 	const struct fs_parameter_spec *spec;
2951 
2952 	for (spec = ext4_param_specs; spec->name != NULL; spec++)
2953 		if (spec->opt == token && !spec->type)
2954 			break;
2955 	return spec->name;
2956 }
2957 
2958 /*
2959  * Show an option if
2960  *  - it's set to a non-default value OR
2961  *  - if the per-sb default is different from the global default
2962  */
2963 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2964 			      int nodefs)
2965 {
2966 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2967 	struct ext4_super_block *es = sbi->s_es;
2968 	int def_errors;
2969 	const struct mount_opts *m;
2970 	char sep = nodefs ? '\n' : ',';
2971 
2972 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2973 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2974 
2975 	if (sbi->s_sb_block != 1)
2976 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2977 
2978 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2979 		int want_set = m->flags & MOPT_SET;
2980 		int opt_2 = m->flags & MOPT_2;
2981 		unsigned int mount_opt, def_mount_opt;
2982 
2983 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2984 		    m->flags & MOPT_SKIP)
2985 			continue;
2986 
2987 		if (opt_2) {
2988 			mount_opt = sbi->s_mount_opt2;
2989 			def_mount_opt = sbi->s_def_mount_opt2;
2990 		} else {
2991 			mount_opt = sbi->s_mount_opt;
2992 			def_mount_opt = sbi->s_def_mount_opt;
2993 		}
2994 		/* skip if same as the default */
2995 		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
2996 			continue;
2997 		/* select Opt_noFoo vs Opt_Foo */
2998 		if ((want_set &&
2999 		     (mount_opt & m->mount_opt) != m->mount_opt) ||
3000 		    (!want_set && (mount_opt & m->mount_opt)))
3001 			continue;
3002 		SEQ_OPTS_PRINT("%s", token2str(m->token));
3003 	}
3004 
3005 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
3006 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
3007 		SEQ_OPTS_PRINT("resuid=%u",
3008 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
3009 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
3010 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
3011 		SEQ_OPTS_PRINT("resgid=%u",
3012 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
3013 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
3014 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3015 		SEQ_OPTS_PUTS("errors=remount-ro");
3016 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3017 		SEQ_OPTS_PUTS("errors=continue");
3018 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3019 		SEQ_OPTS_PUTS("errors=panic");
3020 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3021 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3022 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3023 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3024 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3025 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3026 	if (nodefs || sbi->s_stripe)
3027 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3028 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3029 			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3030 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3031 			SEQ_OPTS_PUTS("data=journal");
3032 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3033 			SEQ_OPTS_PUTS("data=ordered");
3034 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3035 			SEQ_OPTS_PUTS("data=writeback");
3036 	}
3037 	if (nodefs ||
3038 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3039 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3040 			       sbi->s_inode_readahead_blks);
3041 
3042 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3043 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3044 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3045 	if (nodefs || sbi->s_max_dir_size_kb)
3046 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3047 	if (test_opt(sb, DATA_ERR_ABORT))
3048 		SEQ_OPTS_PUTS("data_err=abort");
3049 
3050 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
3051 
3052 	if (sb->s_flags & SB_INLINECRYPT)
3053 		SEQ_OPTS_PUTS("inlinecrypt");
3054 
3055 	if (test_opt(sb, DAX_ALWAYS)) {
3056 		if (IS_EXT2_SB(sb))
3057 			SEQ_OPTS_PUTS("dax");
3058 		else
3059 			SEQ_OPTS_PUTS("dax=always");
3060 	} else if (test_opt2(sb, DAX_NEVER)) {
3061 		SEQ_OPTS_PUTS("dax=never");
3062 	} else if (test_opt2(sb, DAX_INODE)) {
3063 		SEQ_OPTS_PUTS("dax=inode");
3064 	}
3065 
3066 	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3067 			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3068 		SEQ_OPTS_PUTS("mb_optimize_scan=0");
3069 	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3070 			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3071 		SEQ_OPTS_PUTS("mb_optimize_scan=1");
3072 	}
3073 
3074 	ext4_show_quota_options(seq, sb);
3075 	return 0;
3076 }
3077 
3078 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3079 {
3080 	return _ext4_show_options(seq, root->d_sb, 0);
3081 }
3082 
3083 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3084 {
3085 	struct super_block *sb = seq->private;
3086 	int rc;
3087 
3088 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3089 	rc = _ext4_show_options(seq, sb, 1);
3090 	seq_puts(seq, "\n");
3091 	return rc;
3092 }
3093 
3094 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3095 			    int read_only)
3096 {
3097 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3098 	int err = 0;
3099 
3100 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3101 		ext4_msg(sb, KERN_ERR, "revision level too high, "
3102 			 "forcing read-only mode");
3103 		err = -EROFS;
3104 		goto done;
3105 	}
3106 	if (read_only)
3107 		goto done;
3108 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
3109 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3110 			 "running e2fsck is recommended");
3111 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
3112 		ext4_msg(sb, KERN_WARNING,
3113 			 "warning: mounting fs with errors, "
3114 			 "running e2fsck is recommended");
3115 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3116 		 le16_to_cpu(es->s_mnt_count) >=
3117 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3118 		ext4_msg(sb, KERN_WARNING,
3119 			 "warning: maximal mount count reached, "
3120 			 "running e2fsck is recommended");
3121 	else if (le32_to_cpu(es->s_checkinterval) &&
3122 		 (ext4_get_tstamp(es, s_lastcheck) +
3123 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3124 		ext4_msg(sb, KERN_WARNING,
3125 			 "warning: checktime reached, "
3126 			 "running e2fsck is recommended");
3127 	if (!sbi->s_journal)
3128 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3129 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3130 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3131 	le16_add_cpu(&es->s_mnt_count, 1);
3132 	ext4_update_tstamp(es, s_mtime);
3133 	if (sbi->s_journal) {
3134 		ext4_set_feature_journal_needs_recovery(sb);
3135 		if (ext4_has_feature_orphan_file(sb))
3136 			ext4_set_feature_orphan_present(sb);
3137 	}
3138 
3139 	err = ext4_commit_super(sb);
3140 done:
3141 	if (test_opt(sb, DEBUG))
3142 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3143 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3144 			sb->s_blocksize,
3145 			sbi->s_groups_count,
3146 			EXT4_BLOCKS_PER_GROUP(sb),
3147 			EXT4_INODES_PER_GROUP(sb),
3148 			sbi->s_mount_opt, sbi->s_mount_opt2);
3149 	return err;
3150 }
3151 
3152 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3153 {
3154 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3155 	struct flex_groups **old_groups, **new_groups;
3156 	int size, i, j;
3157 
3158 	if (!sbi->s_log_groups_per_flex)
3159 		return 0;
3160 
3161 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
3162 	if (size <= sbi->s_flex_groups_allocated)
3163 		return 0;
3164 
3165 	new_groups = kvzalloc(roundup_pow_of_two(size *
3166 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3167 	if (!new_groups) {
3168 		ext4_msg(sb, KERN_ERR,
3169 			 "not enough memory for %d flex group pointers", size);
3170 		return -ENOMEM;
3171 	}
3172 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3173 		new_groups[i] = kvzalloc(roundup_pow_of_two(
3174 					 sizeof(struct flex_groups)),
3175 					 GFP_KERNEL);
3176 		if (!new_groups[i]) {
3177 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
3178 				kvfree(new_groups[j]);
3179 			kvfree(new_groups);
3180 			ext4_msg(sb, KERN_ERR,
3181 				 "not enough memory for %d flex groups", size);
3182 			return -ENOMEM;
3183 		}
3184 	}
3185 	rcu_read_lock();
3186 	old_groups = rcu_dereference(sbi->s_flex_groups);
3187 	if (old_groups)
3188 		memcpy(new_groups, old_groups,
3189 		       (sbi->s_flex_groups_allocated *
3190 			sizeof(struct flex_groups *)));
3191 	rcu_read_unlock();
3192 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3193 	sbi->s_flex_groups_allocated = size;
3194 	if (old_groups)
3195 		ext4_kvfree_array_rcu(old_groups);
3196 	return 0;
3197 }
3198 
3199 static int ext4_fill_flex_info(struct super_block *sb)
3200 {
3201 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3202 	struct ext4_group_desc *gdp = NULL;
3203 	struct flex_groups *fg;
3204 	ext4_group_t flex_group;
3205 	int i, err;
3206 
3207 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3208 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3209 		sbi->s_log_groups_per_flex = 0;
3210 		return 1;
3211 	}
3212 
3213 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3214 	if (err)
3215 		goto failed;
3216 
3217 	for (i = 0; i < sbi->s_groups_count; i++) {
3218 		gdp = ext4_get_group_desc(sb, i, NULL);
3219 
3220 		flex_group = ext4_flex_group(sbi, i);
3221 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3222 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3223 		atomic64_add(ext4_free_group_clusters(sb, gdp),
3224 			     &fg->free_clusters);
3225 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3226 	}
3227 
3228 	return 1;
3229 failed:
3230 	return 0;
3231 }
3232 
3233 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3234 				   struct ext4_group_desc *gdp)
3235 {
3236 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
3237 	__u16 crc = 0;
3238 	__le32 le_group = cpu_to_le32(block_group);
3239 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3240 
3241 	if (ext4_has_metadata_csum(sbi->s_sb)) {
3242 		/* Use new metadata_csum algorithm */
3243 		__u32 csum32;
3244 		__u16 dummy_csum = 0;
3245 
3246 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3247 				     sizeof(le_group));
3248 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3249 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3250 				     sizeof(dummy_csum));
3251 		offset += sizeof(dummy_csum);
3252 		if (offset < sbi->s_desc_size)
3253 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3254 					     sbi->s_desc_size - offset);
3255 
3256 		crc = csum32 & 0xFFFF;
3257 		goto out;
3258 	}
3259 
3260 	/* old crc16 code */
3261 	if (!ext4_has_feature_gdt_csum(sb))
3262 		return 0;
3263 
3264 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3265 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3266 	crc = crc16(crc, (__u8 *)gdp, offset);
3267 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
3268 	/* for checksum of struct ext4_group_desc do the rest...*/
3269 	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
3270 		crc = crc16(crc, (__u8 *)gdp + offset,
3271 			    sbi->s_desc_size - offset);
3272 
3273 out:
3274 	return cpu_to_le16(crc);
3275 }
3276 
3277 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3278 				struct ext4_group_desc *gdp)
3279 {
3280 	if (ext4_has_group_desc_csum(sb) &&
3281 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3282 		return 0;
3283 
3284 	return 1;
3285 }
3286 
3287 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3288 			      struct ext4_group_desc *gdp)
3289 {
3290 	if (!ext4_has_group_desc_csum(sb))
3291 		return;
3292 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3293 }
3294 
3295 /* Called at mount-time, super-block is locked */
3296 static int ext4_check_descriptors(struct super_block *sb,
3297 				  ext4_fsblk_t sb_block,
3298 				  ext4_group_t *first_not_zeroed)
3299 {
3300 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3301 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3302 	ext4_fsblk_t last_block;
3303 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3304 	ext4_fsblk_t block_bitmap;
3305 	ext4_fsblk_t inode_bitmap;
3306 	ext4_fsblk_t inode_table;
3307 	int flexbg_flag = 0;
3308 	ext4_group_t i, grp = sbi->s_groups_count;
3309 
3310 	if (ext4_has_feature_flex_bg(sb))
3311 		flexbg_flag = 1;
3312 
3313 	ext4_debug("Checking group descriptors");
3314 
3315 	for (i = 0; i < sbi->s_groups_count; i++) {
3316 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3317 
3318 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
3319 			last_block = ext4_blocks_count(sbi->s_es) - 1;
3320 		else
3321 			last_block = first_block +
3322 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
3323 
3324 		if ((grp == sbi->s_groups_count) &&
3325 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3326 			grp = i;
3327 
3328 		block_bitmap = ext4_block_bitmap(sb, gdp);
3329 		if (block_bitmap == sb_block) {
3330 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3331 				 "Block bitmap for group %u overlaps "
3332 				 "superblock", i);
3333 			if (!sb_rdonly(sb))
3334 				return 0;
3335 		}
3336 		if (block_bitmap >= sb_block + 1 &&
3337 		    block_bitmap <= last_bg_block) {
3338 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3339 				 "Block bitmap for group %u overlaps "
3340 				 "block group descriptors", i);
3341 			if (!sb_rdonly(sb))
3342 				return 0;
3343 		}
3344 		if (block_bitmap < first_block || block_bitmap > last_block) {
3345 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3346 			       "Block bitmap for group %u not in group "
3347 			       "(block %llu)!", i, block_bitmap);
3348 			return 0;
3349 		}
3350 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
3351 		if (inode_bitmap == sb_block) {
3352 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3353 				 "Inode bitmap for group %u overlaps "
3354 				 "superblock", i);
3355 			if (!sb_rdonly(sb))
3356 				return 0;
3357 		}
3358 		if (inode_bitmap >= sb_block + 1 &&
3359 		    inode_bitmap <= last_bg_block) {
3360 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3361 				 "Inode bitmap for group %u overlaps "
3362 				 "block group descriptors", i);
3363 			if (!sb_rdonly(sb))
3364 				return 0;
3365 		}
3366 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
3367 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3368 			       "Inode bitmap for group %u not in group "
3369 			       "(block %llu)!", i, inode_bitmap);
3370 			return 0;
3371 		}
3372 		inode_table = ext4_inode_table(sb, gdp);
3373 		if (inode_table == sb_block) {
3374 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3375 				 "Inode table for group %u overlaps "
3376 				 "superblock", i);
3377 			if (!sb_rdonly(sb))
3378 				return 0;
3379 		}
3380 		if (inode_table >= sb_block + 1 &&
3381 		    inode_table <= last_bg_block) {
3382 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3383 				 "Inode table for group %u overlaps "
3384 				 "block group descriptors", i);
3385 			if (!sb_rdonly(sb))
3386 				return 0;
3387 		}
3388 		if (inode_table < first_block ||
3389 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
3390 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3391 			       "Inode table for group %u not in group "
3392 			       "(block %llu)!", i, inode_table);
3393 			return 0;
3394 		}
3395 		ext4_lock_group(sb, i);
3396 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3397 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3398 				 "Checksum for group %u failed (%u!=%u)",
3399 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3400 				     gdp)), le16_to_cpu(gdp->bg_checksum));
3401 			if (!sb_rdonly(sb)) {
3402 				ext4_unlock_group(sb, i);
3403 				return 0;
3404 			}
3405 		}
3406 		ext4_unlock_group(sb, i);
3407 		if (!flexbg_flag)
3408 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
3409 	}
3410 	if (NULL != first_not_zeroed)
3411 		*first_not_zeroed = grp;
3412 	return 1;
3413 }
3414 
3415 /*
3416  * Maximal extent format file size.
3417  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3418  * extent format containers, within a sector_t, and within i_blocks
3419  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3420  * so that won't be a limiting factor.
3421  *
3422  * However there is other limiting factor. We do store extents in the form
3423  * of starting block and length, hence the resulting length of the extent
3424  * covering maximum file size must fit into on-disk format containers as
3425  * well. Given that length is always by 1 unit bigger than max unit (because
3426  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3427  *
3428  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3429  */
3430 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3431 {
3432 	loff_t res;
3433 	loff_t upper_limit = MAX_LFS_FILESIZE;
3434 
3435 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3436 
3437 	if (!has_huge_files) {
3438 		upper_limit = (1LL << 32) - 1;
3439 
3440 		/* total blocks in file system block size */
3441 		upper_limit >>= (blkbits - 9);
3442 		upper_limit <<= blkbits;
3443 	}
3444 
3445 	/*
3446 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3447 	 * by one fs block, so ee_len can cover the extent of maximum file
3448 	 * size
3449 	 */
3450 	res = (1LL << 32) - 1;
3451 	res <<= blkbits;
3452 
3453 	/* Sanity check against vm- & vfs- imposed limits */
3454 	if (res > upper_limit)
3455 		res = upper_limit;
3456 
3457 	return res;
3458 }
3459 
3460 /*
3461  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3462  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3463  * We need to be 1 filesystem block less than the 2^48 sector limit.
3464  */
3465 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3466 {
3467 	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3468 	int meta_blocks;
3469 	unsigned int ppb = 1 << (bits - 2);
3470 
3471 	/*
3472 	 * This is calculated to be the largest file size for a dense, block
3473 	 * mapped file such that the file's total number of 512-byte sectors,
3474 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3475 	 *
3476 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3477 	 * number of 512-byte sectors of the file.
3478 	 */
3479 	if (!has_huge_files) {
3480 		/*
3481 		 * !has_huge_files or implies that the inode i_block field
3482 		 * represents total file blocks in 2^32 512-byte sectors ==
3483 		 * size of vfs inode i_blocks * 8
3484 		 */
3485 		upper_limit = (1LL << 32) - 1;
3486 
3487 		/* total blocks in file system block size */
3488 		upper_limit >>= (bits - 9);
3489 
3490 	} else {
3491 		/*
3492 		 * We use 48 bit ext4_inode i_blocks
3493 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3494 		 * represent total number of blocks in
3495 		 * file system block size
3496 		 */
3497 		upper_limit = (1LL << 48) - 1;
3498 
3499 	}
3500 
3501 	/* Compute how many blocks we can address by block tree */
3502 	res += ppb;
3503 	res += ppb * ppb;
3504 	res += ((loff_t)ppb) * ppb * ppb;
3505 	/* Compute how many metadata blocks are needed */
3506 	meta_blocks = 1;
3507 	meta_blocks += 1 + ppb;
3508 	meta_blocks += 1 + ppb + ppb * ppb;
3509 	/* Does block tree limit file size? */
3510 	if (res + meta_blocks <= upper_limit)
3511 		goto check_lfs;
3512 
3513 	res = upper_limit;
3514 	/* How many metadata blocks are needed for addressing upper_limit? */
3515 	upper_limit -= EXT4_NDIR_BLOCKS;
3516 	/* indirect blocks */
3517 	meta_blocks = 1;
3518 	upper_limit -= ppb;
3519 	/* double indirect blocks */
3520 	if (upper_limit < ppb * ppb) {
3521 		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3522 		res -= meta_blocks;
3523 		goto check_lfs;
3524 	}
3525 	meta_blocks += 1 + ppb;
3526 	upper_limit -= ppb * ppb;
3527 	/* tripple indirect blocks for the rest */
3528 	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3529 		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3530 	res -= meta_blocks;
3531 check_lfs:
3532 	res <<= bits;
3533 	if (res > MAX_LFS_FILESIZE)
3534 		res = MAX_LFS_FILESIZE;
3535 
3536 	return res;
3537 }
3538 
3539 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3540 				   ext4_fsblk_t logical_sb_block, int nr)
3541 {
3542 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3543 	ext4_group_t bg, first_meta_bg;
3544 	int has_super = 0;
3545 
3546 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3547 
3548 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3549 		return logical_sb_block + nr + 1;
3550 	bg = sbi->s_desc_per_block * nr;
3551 	if (ext4_bg_has_super(sb, bg))
3552 		has_super = 1;
3553 
3554 	/*
3555 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3556 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3557 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3558 	 * compensate.
3559 	 */
3560 	if (sb->s_blocksize == 1024 && nr == 0 &&
3561 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3562 		has_super++;
3563 
3564 	return (has_super + ext4_group_first_block_no(sb, bg));
3565 }
3566 
3567 /**
3568  * ext4_get_stripe_size: Get the stripe size.
3569  * @sbi: In memory super block info
3570  *
3571  * If we have specified it via mount option, then
3572  * use the mount option value. If the value specified at mount time is
3573  * greater than the blocks per group use the super block value.
3574  * If the super block value is greater than blocks per group return 0.
3575  * Allocator needs it be less than blocks per group.
3576  *
3577  */
3578 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3579 {
3580 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3581 	unsigned long stripe_width =
3582 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3583 	int ret;
3584 
3585 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3586 		ret = sbi->s_stripe;
3587 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3588 		ret = stripe_width;
3589 	else if (stride && stride <= sbi->s_blocks_per_group)
3590 		ret = stride;
3591 	else
3592 		ret = 0;
3593 
3594 	/*
3595 	 * If the stripe width is 1, this makes no sense and
3596 	 * we set it to 0 to turn off stripe handling code.
3597 	 */
3598 	if (ret <= 1)
3599 		ret = 0;
3600 
3601 	return ret;
3602 }
3603 
3604 /*
3605  * Check whether this filesystem can be mounted based on
3606  * the features present and the RDONLY/RDWR mount requested.
3607  * Returns 1 if this filesystem can be mounted as requested,
3608  * 0 if it cannot be.
3609  */
3610 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3611 {
3612 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3613 		ext4_msg(sb, KERN_ERR,
3614 			"Couldn't mount because of "
3615 			"unsupported optional features (%x)",
3616 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3617 			~EXT4_FEATURE_INCOMPAT_SUPP));
3618 		return 0;
3619 	}
3620 
3621 #if !IS_ENABLED(CONFIG_UNICODE)
3622 	if (ext4_has_feature_casefold(sb)) {
3623 		ext4_msg(sb, KERN_ERR,
3624 			 "Filesystem with casefold feature cannot be "
3625 			 "mounted without CONFIG_UNICODE");
3626 		return 0;
3627 	}
3628 #endif
3629 
3630 	if (readonly)
3631 		return 1;
3632 
3633 	if (ext4_has_feature_readonly(sb)) {
3634 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3635 		sb->s_flags |= SB_RDONLY;
3636 		return 1;
3637 	}
3638 
3639 	/* Check that feature set is OK for a read-write mount */
3640 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3641 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3642 			 "unsupported optional features (%x)",
3643 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3644 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3645 		return 0;
3646 	}
3647 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3648 		ext4_msg(sb, KERN_ERR,
3649 			 "Can't support bigalloc feature without "
3650 			 "extents feature\n");
3651 		return 0;
3652 	}
3653 
3654 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3655 	if (!readonly && (ext4_has_feature_quota(sb) ||
3656 			  ext4_has_feature_project(sb))) {
3657 		ext4_msg(sb, KERN_ERR,
3658 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3659 		return 0;
3660 	}
3661 #endif  /* CONFIG_QUOTA */
3662 	return 1;
3663 }
3664 
3665 /*
3666  * This function is called once a day if we have errors logged
3667  * on the file system
3668  */
3669 static void print_daily_error_info(struct timer_list *t)
3670 {
3671 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3672 	struct super_block *sb = sbi->s_sb;
3673 	struct ext4_super_block *es = sbi->s_es;
3674 
3675 	if (es->s_error_count)
3676 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3677 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3678 			 le32_to_cpu(es->s_error_count));
3679 	if (es->s_first_error_time) {
3680 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3681 		       sb->s_id,
3682 		       ext4_get_tstamp(es, s_first_error_time),
3683 		       (int) sizeof(es->s_first_error_func),
3684 		       es->s_first_error_func,
3685 		       le32_to_cpu(es->s_first_error_line));
3686 		if (es->s_first_error_ino)
3687 			printk(KERN_CONT ": inode %u",
3688 			       le32_to_cpu(es->s_first_error_ino));
3689 		if (es->s_first_error_block)
3690 			printk(KERN_CONT ": block %llu", (unsigned long long)
3691 			       le64_to_cpu(es->s_first_error_block));
3692 		printk(KERN_CONT "\n");
3693 	}
3694 	if (es->s_last_error_time) {
3695 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3696 		       sb->s_id,
3697 		       ext4_get_tstamp(es, s_last_error_time),
3698 		       (int) sizeof(es->s_last_error_func),
3699 		       es->s_last_error_func,
3700 		       le32_to_cpu(es->s_last_error_line));
3701 		if (es->s_last_error_ino)
3702 			printk(KERN_CONT ": inode %u",
3703 			       le32_to_cpu(es->s_last_error_ino));
3704 		if (es->s_last_error_block)
3705 			printk(KERN_CONT ": block %llu", (unsigned long long)
3706 			       le64_to_cpu(es->s_last_error_block));
3707 		printk(KERN_CONT "\n");
3708 	}
3709 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3710 }
3711 
3712 /* Find next suitable group and run ext4_init_inode_table */
3713 static int ext4_run_li_request(struct ext4_li_request *elr)
3714 {
3715 	struct ext4_group_desc *gdp = NULL;
3716 	struct super_block *sb = elr->lr_super;
3717 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3718 	ext4_group_t group = elr->lr_next_group;
3719 	unsigned int prefetch_ios = 0;
3720 	int ret = 0;
3721 	int nr = EXT4_SB(sb)->s_mb_prefetch;
3722 	u64 start_time;
3723 
3724 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3725 		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
3726 		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
3727 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
3728 		if (group >= elr->lr_next_group) {
3729 			ret = 1;
3730 			if (elr->lr_first_not_zeroed != ngroups &&
3731 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3732 				elr->lr_next_group = elr->lr_first_not_zeroed;
3733 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3734 				ret = 0;
3735 			}
3736 		}
3737 		return ret;
3738 	}
3739 
3740 	for (; group < ngroups; group++) {
3741 		gdp = ext4_get_group_desc(sb, group, NULL);
3742 		if (!gdp) {
3743 			ret = 1;
3744 			break;
3745 		}
3746 
3747 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3748 			break;
3749 	}
3750 
3751 	if (group >= ngroups)
3752 		ret = 1;
3753 
3754 	if (!ret) {
3755 		start_time = ktime_get_real_ns();
3756 		ret = ext4_init_inode_table(sb, group,
3757 					    elr->lr_timeout ? 0 : 1);
3758 		trace_ext4_lazy_itable_init(sb, group);
3759 		if (elr->lr_timeout == 0) {
3760 			elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3761 				EXT4_SB(elr->lr_super)->s_li_wait_mult);
3762 		}
3763 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3764 		elr->lr_next_group = group + 1;
3765 	}
3766 	return ret;
3767 }
3768 
3769 /*
3770  * Remove lr_request from the list_request and free the
3771  * request structure. Should be called with li_list_mtx held
3772  */
3773 static void ext4_remove_li_request(struct ext4_li_request *elr)
3774 {
3775 	if (!elr)
3776 		return;
3777 
3778 	list_del(&elr->lr_request);
3779 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3780 	kfree(elr);
3781 }
3782 
3783 static void ext4_unregister_li_request(struct super_block *sb)
3784 {
3785 	mutex_lock(&ext4_li_mtx);
3786 	if (!ext4_li_info) {
3787 		mutex_unlock(&ext4_li_mtx);
3788 		return;
3789 	}
3790 
3791 	mutex_lock(&ext4_li_info->li_list_mtx);
3792 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3793 	mutex_unlock(&ext4_li_info->li_list_mtx);
3794 	mutex_unlock(&ext4_li_mtx);
3795 }
3796 
3797 static struct task_struct *ext4_lazyinit_task;
3798 
3799 /*
3800  * This is the function where ext4lazyinit thread lives. It walks
3801  * through the request list searching for next scheduled filesystem.
3802  * When such a fs is found, run the lazy initialization request
3803  * (ext4_rn_li_request) and keep track of the time spend in this
3804  * function. Based on that time we compute next schedule time of
3805  * the request. When walking through the list is complete, compute
3806  * next waking time and put itself into sleep.
3807  */
3808 static int ext4_lazyinit_thread(void *arg)
3809 {
3810 	struct ext4_lazy_init *eli = arg;
3811 	struct list_head *pos, *n;
3812 	struct ext4_li_request *elr;
3813 	unsigned long next_wakeup, cur;
3814 
3815 	BUG_ON(NULL == eli);
3816 	set_freezable();
3817 
3818 cont_thread:
3819 	while (true) {
3820 		next_wakeup = MAX_JIFFY_OFFSET;
3821 
3822 		mutex_lock(&eli->li_list_mtx);
3823 		if (list_empty(&eli->li_request_list)) {
3824 			mutex_unlock(&eli->li_list_mtx);
3825 			goto exit_thread;
3826 		}
3827 		list_for_each_safe(pos, n, &eli->li_request_list) {
3828 			int err = 0;
3829 			int progress = 0;
3830 			elr = list_entry(pos, struct ext4_li_request,
3831 					 lr_request);
3832 
3833 			if (time_before(jiffies, elr->lr_next_sched)) {
3834 				if (time_before(elr->lr_next_sched, next_wakeup))
3835 					next_wakeup = elr->lr_next_sched;
3836 				continue;
3837 			}
3838 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3839 				if (sb_start_write_trylock(elr->lr_super)) {
3840 					progress = 1;
3841 					/*
3842 					 * We hold sb->s_umount, sb can not
3843 					 * be removed from the list, it is
3844 					 * now safe to drop li_list_mtx
3845 					 */
3846 					mutex_unlock(&eli->li_list_mtx);
3847 					err = ext4_run_li_request(elr);
3848 					sb_end_write(elr->lr_super);
3849 					mutex_lock(&eli->li_list_mtx);
3850 					n = pos->next;
3851 				}
3852 				up_read((&elr->lr_super->s_umount));
3853 			}
3854 			/* error, remove the lazy_init job */
3855 			if (err) {
3856 				ext4_remove_li_request(elr);
3857 				continue;
3858 			}
3859 			if (!progress) {
3860 				elr->lr_next_sched = jiffies +
3861 					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
3862 			}
3863 			if (time_before(elr->lr_next_sched, next_wakeup))
3864 				next_wakeup = elr->lr_next_sched;
3865 		}
3866 		mutex_unlock(&eli->li_list_mtx);
3867 
3868 		try_to_freeze();
3869 
3870 		cur = jiffies;
3871 		if ((time_after_eq(cur, next_wakeup)) ||
3872 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3873 			cond_resched();
3874 			continue;
3875 		}
3876 
3877 		schedule_timeout_interruptible(next_wakeup - cur);
3878 
3879 		if (kthread_should_stop()) {
3880 			ext4_clear_request_list();
3881 			goto exit_thread;
3882 		}
3883 	}
3884 
3885 exit_thread:
3886 	/*
3887 	 * It looks like the request list is empty, but we need
3888 	 * to check it under the li_list_mtx lock, to prevent any
3889 	 * additions into it, and of course we should lock ext4_li_mtx
3890 	 * to atomically free the list and ext4_li_info, because at
3891 	 * this point another ext4 filesystem could be registering
3892 	 * new one.
3893 	 */
3894 	mutex_lock(&ext4_li_mtx);
3895 	mutex_lock(&eli->li_list_mtx);
3896 	if (!list_empty(&eli->li_request_list)) {
3897 		mutex_unlock(&eli->li_list_mtx);
3898 		mutex_unlock(&ext4_li_mtx);
3899 		goto cont_thread;
3900 	}
3901 	mutex_unlock(&eli->li_list_mtx);
3902 	kfree(ext4_li_info);
3903 	ext4_li_info = NULL;
3904 	mutex_unlock(&ext4_li_mtx);
3905 
3906 	return 0;
3907 }
3908 
3909 static void ext4_clear_request_list(void)
3910 {
3911 	struct list_head *pos, *n;
3912 	struct ext4_li_request *elr;
3913 
3914 	mutex_lock(&ext4_li_info->li_list_mtx);
3915 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3916 		elr = list_entry(pos, struct ext4_li_request,
3917 				 lr_request);
3918 		ext4_remove_li_request(elr);
3919 	}
3920 	mutex_unlock(&ext4_li_info->li_list_mtx);
3921 }
3922 
3923 static int ext4_run_lazyinit_thread(void)
3924 {
3925 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3926 					 ext4_li_info, "ext4lazyinit");
3927 	if (IS_ERR(ext4_lazyinit_task)) {
3928 		int err = PTR_ERR(ext4_lazyinit_task);
3929 		ext4_clear_request_list();
3930 		kfree(ext4_li_info);
3931 		ext4_li_info = NULL;
3932 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3933 				 "initialization thread\n",
3934 				 err);
3935 		return err;
3936 	}
3937 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3938 	return 0;
3939 }
3940 
3941 /*
3942  * Check whether it make sense to run itable init. thread or not.
3943  * If there is at least one uninitialized inode table, return
3944  * corresponding group number, else the loop goes through all
3945  * groups and return total number of groups.
3946  */
3947 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3948 {
3949 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3950 	struct ext4_group_desc *gdp = NULL;
3951 
3952 	if (!ext4_has_group_desc_csum(sb))
3953 		return ngroups;
3954 
3955 	for (group = 0; group < ngroups; group++) {
3956 		gdp = ext4_get_group_desc(sb, group, NULL);
3957 		if (!gdp)
3958 			continue;
3959 
3960 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3961 			break;
3962 	}
3963 
3964 	return group;
3965 }
3966 
3967 static int ext4_li_info_new(void)
3968 {
3969 	struct ext4_lazy_init *eli = NULL;
3970 
3971 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3972 	if (!eli)
3973 		return -ENOMEM;
3974 
3975 	INIT_LIST_HEAD(&eli->li_request_list);
3976 	mutex_init(&eli->li_list_mtx);
3977 
3978 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3979 
3980 	ext4_li_info = eli;
3981 
3982 	return 0;
3983 }
3984 
3985 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3986 					    ext4_group_t start)
3987 {
3988 	struct ext4_li_request *elr;
3989 
3990 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3991 	if (!elr)
3992 		return NULL;
3993 
3994 	elr->lr_super = sb;
3995 	elr->lr_first_not_zeroed = start;
3996 	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3997 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3998 		elr->lr_next_group = start;
3999 	} else {
4000 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
4001 	}
4002 
4003 	/*
4004 	 * Randomize first schedule time of the request to
4005 	 * spread the inode table initialization requests
4006 	 * better.
4007 	 */
4008 	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
4009 	return elr;
4010 }
4011 
4012 int ext4_register_li_request(struct super_block *sb,
4013 			     ext4_group_t first_not_zeroed)
4014 {
4015 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4016 	struct ext4_li_request *elr = NULL;
4017 	ext4_group_t ngroups = sbi->s_groups_count;
4018 	int ret = 0;
4019 
4020 	mutex_lock(&ext4_li_mtx);
4021 	if (sbi->s_li_request != NULL) {
4022 		/*
4023 		 * Reset timeout so it can be computed again, because
4024 		 * s_li_wait_mult might have changed.
4025 		 */
4026 		sbi->s_li_request->lr_timeout = 0;
4027 		goto out;
4028 	}
4029 
4030 	if (sb_rdonly(sb) ||
4031 	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4032 	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
4033 		goto out;
4034 
4035 	elr = ext4_li_request_new(sb, first_not_zeroed);
4036 	if (!elr) {
4037 		ret = -ENOMEM;
4038 		goto out;
4039 	}
4040 
4041 	if (NULL == ext4_li_info) {
4042 		ret = ext4_li_info_new();
4043 		if (ret)
4044 			goto out;
4045 	}
4046 
4047 	mutex_lock(&ext4_li_info->li_list_mtx);
4048 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4049 	mutex_unlock(&ext4_li_info->li_list_mtx);
4050 
4051 	sbi->s_li_request = elr;
4052 	/*
4053 	 * set elr to NULL here since it has been inserted to
4054 	 * the request_list and the removal and free of it is
4055 	 * handled by ext4_clear_request_list from now on.
4056 	 */
4057 	elr = NULL;
4058 
4059 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4060 		ret = ext4_run_lazyinit_thread();
4061 		if (ret)
4062 			goto out;
4063 	}
4064 out:
4065 	mutex_unlock(&ext4_li_mtx);
4066 	if (ret)
4067 		kfree(elr);
4068 	return ret;
4069 }
4070 
4071 /*
4072  * We do not need to lock anything since this is called on
4073  * module unload.
4074  */
4075 static void ext4_destroy_lazyinit_thread(void)
4076 {
4077 	/*
4078 	 * If thread exited earlier
4079 	 * there's nothing to be done.
4080 	 */
4081 	if (!ext4_li_info || !ext4_lazyinit_task)
4082 		return;
4083 
4084 	kthread_stop(ext4_lazyinit_task);
4085 }
4086 
4087 static int set_journal_csum_feature_set(struct super_block *sb)
4088 {
4089 	int ret = 1;
4090 	int compat, incompat;
4091 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4092 
4093 	if (ext4_has_metadata_csum(sb)) {
4094 		/* journal checksum v3 */
4095 		compat = 0;
4096 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4097 	} else {
4098 		/* journal checksum v1 */
4099 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4100 		incompat = 0;
4101 	}
4102 
4103 	jbd2_journal_clear_features(sbi->s_journal,
4104 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4105 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4106 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
4107 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4108 		ret = jbd2_journal_set_features(sbi->s_journal,
4109 				compat, 0,
4110 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4111 				incompat);
4112 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4113 		ret = jbd2_journal_set_features(sbi->s_journal,
4114 				compat, 0,
4115 				incompat);
4116 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4117 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4118 	} else {
4119 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4120 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4121 	}
4122 
4123 	return ret;
4124 }
4125 
4126 /*
4127  * Note: calculating the overhead so we can be compatible with
4128  * historical BSD practice is quite difficult in the face of
4129  * clusters/bigalloc.  This is because multiple metadata blocks from
4130  * different block group can end up in the same allocation cluster.
4131  * Calculating the exact overhead in the face of clustered allocation
4132  * requires either O(all block bitmaps) in memory or O(number of block
4133  * groups**2) in time.  We will still calculate the superblock for
4134  * older file systems --- and if we come across with a bigalloc file
4135  * system with zero in s_overhead_clusters the estimate will be close to
4136  * correct especially for very large cluster sizes --- but for newer
4137  * file systems, it's better to calculate this figure once at mkfs
4138  * time, and store it in the superblock.  If the superblock value is
4139  * present (even for non-bigalloc file systems), we will use it.
4140  */
4141 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4142 			  char *buf)
4143 {
4144 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
4145 	struct ext4_group_desc	*gdp;
4146 	ext4_fsblk_t		first_block, last_block, b;
4147 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
4148 	int			s, j, count = 0;
4149 	int			has_super = ext4_bg_has_super(sb, grp);
4150 
4151 	if (!ext4_has_feature_bigalloc(sb))
4152 		return (has_super + ext4_bg_num_gdb(sb, grp) +
4153 			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4154 			sbi->s_itb_per_group + 2);
4155 
4156 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4157 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
4158 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4159 	for (i = 0; i < ngroups; i++) {
4160 		gdp = ext4_get_group_desc(sb, i, NULL);
4161 		b = ext4_block_bitmap(sb, gdp);
4162 		if (b >= first_block && b <= last_block) {
4163 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4164 			count++;
4165 		}
4166 		b = ext4_inode_bitmap(sb, gdp);
4167 		if (b >= first_block && b <= last_block) {
4168 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4169 			count++;
4170 		}
4171 		b = ext4_inode_table(sb, gdp);
4172 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4173 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4174 				int c = EXT4_B2C(sbi, b - first_block);
4175 				ext4_set_bit(c, buf);
4176 				count++;
4177 			}
4178 		if (i != grp)
4179 			continue;
4180 		s = 0;
4181 		if (ext4_bg_has_super(sb, grp)) {
4182 			ext4_set_bit(s++, buf);
4183 			count++;
4184 		}
4185 		j = ext4_bg_num_gdb(sb, grp);
4186 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4187 			ext4_error(sb, "Invalid number of block group "
4188 				   "descriptor blocks: %d", j);
4189 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4190 		}
4191 		count += j;
4192 		for (; j > 0; j--)
4193 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4194 	}
4195 	if (!count)
4196 		return 0;
4197 	return EXT4_CLUSTERS_PER_GROUP(sb) -
4198 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4199 }
4200 
4201 /*
4202  * Compute the overhead and stash it in sbi->s_overhead
4203  */
4204 int ext4_calculate_overhead(struct super_block *sb)
4205 {
4206 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4207 	struct ext4_super_block *es = sbi->s_es;
4208 	struct inode *j_inode;
4209 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4210 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4211 	ext4_fsblk_t overhead = 0;
4212 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
4213 
4214 	if (!buf)
4215 		return -ENOMEM;
4216 
4217 	/*
4218 	 * Compute the overhead (FS structures).  This is constant
4219 	 * for a given filesystem unless the number of block groups
4220 	 * changes so we cache the previous value until it does.
4221 	 */
4222 
4223 	/*
4224 	 * All of the blocks before first_data_block are overhead
4225 	 */
4226 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4227 
4228 	/*
4229 	 * Add the overhead found in each block group
4230 	 */
4231 	for (i = 0; i < ngroups; i++) {
4232 		int blks;
4233 
4234 		blks = count_overhead(sb, i, buf);
4235 		overhead += blks;
4236 		if (blks)
4237 			memset(buf, 0, PAGE_SIZE);
4238 		cond_resched();
4239 	}
4240 
4241 	/*
4242 	 * Add the internal journal blocks whether the journal has been
4243 	 * loaded or not
4244 	 */
4245 	if (sbi->s_journal && !sbi->s_journal_bdev)
4246 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4247 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4248 		/* j_inum for internal journal is non-zero */
4249 		j_inode = ext4_get_journal_inode(sb, j_inum);
4250 		if (!IS_ERR(j_inode)) {
4251 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4252 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
4253 			iput(j_inode);
4254 		} else {
4255 			ext4_msg(sb, KERN_ERR, "can't get journal size");
4256 		}
4257 	}
4258 	sbi->s_overhead = overhead;
4259 	smp_wmb();
4260 	free_page((unsigned long) buf);
4261 	return 0;
4262 }
4263 
4264 static void ext4_set_resv_clusters(struct super_block *sb)
4265 {
4266 	ext4_fsblk_t resv_clusters;
4267 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4268 
4269 	/*
4270 	 * There's no need to reserve anything when we aren't using extents.
4271 	 * The space estimates are exact, there are no unwritten extents,
4272 	 * hole punching doesn't need new metadata... This is needed especially
4273 	 * to keep ext2/3 backward compatibility.
4274 	 */
4275 	if (!ext4_has_feature_extents(sb))
4276 		return;
4277 	/*
4278 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4279 	 * This should cover the situations where we can not afford to run
4280 	 * out of space like for example punch hole, or converting
4281 	 * unwritten extents in delalloc path. In most cases such
4282 	 * allocation would require 1, or 2 blocks, higher numbers are
4283 	 * very rare.
4284 	 */
4285 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4286 			 sbi->s_cluster_bits);
4287 
4288 	do_div(resv_clusters, 50);
4289 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4290 
4291 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4292 }
4293 
4294 static const char *ext4_quota_mode(struct super_block *sb)
4295 {
4296 #ifdef CONFIG_QUOTA
4297 	if (!ext4_quota_capable(sb))
4298 		return "none";
4299 
4300 	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4301 		return "journalled";
4302 	else
4303 		return "writeback";
4304 #else
4305 	return "disabled";
4306 #endif
4307 }
4308 
4309 static void ext4_setup_csum_trigger(struct super_block *sb,
4310 				    enum ext4_journal_trigger_type type,
4311 				    void (*trigger)(
4312 					struct jbd2_buffer_trigger_type *type,
4313 					struct buffer_head *bh,
4314 					void *mapped_data,
4315 					size_t size))
4316 {
4317 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4318 
4319 	sbi->s_journal_triggers[type].sb = sb;
4320 	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4321 }
4322 
4323 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4324 {
4325 	if (!sbi)
4326 		return;
4327 
4328 	kfree(sbi->s_blockgroup_lock);
4329 	fs_put_dax(sbi->s_daxdev, NULL);
4330 	kfree(sbi);
4331 }
4332 
4333 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4334 {
4335 	struct ext4_sb_info *sbi;
4336 
4337 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4338 	if (!sbi)
4339 		return NULL;
4340 
4341 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4342 					   NULL, NULL);
4343 
4344 	sbi->s_blockgroup_lock =
4345 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4346 
4347 	if (!sbi->s_blockgroup_lock)
4348 		goto err_out;
4349 
4350 	sb->s_fs_info = sbi;
4351 	sbi->s_sb = sb;
4352 	return sbi;
4353 err_out:
4354 	fs_put_dax(sbi->s_daxdev, NULL);
4355 	kfree(sbi);
4356 	return NULL;
4357 }
4358 
4359 static void ext4_set_def_opts(struct super_block *sb,
4360 			      struct ext4_super_block *es)
4361 {
4362 	unsigned long def_mount_opts;
4363 
4364 	/* Set defaults before we parse the mount options */
4365 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4366 	set_opt(sb, INIT_INODE_TABLE);
4367 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4368 		set_opt(sb, DEBUG);
4369 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4370 		set_opt(sb, GRPID);
4371 	if (def_mount_opts & EXT4_DEFM_UID16)
4372 		set_opt(sb, NO_UID32);
4373 	/* xattr user namespace & acls are now defaulted on */
4374 	set_opt(sb, XATTR_USER);
4375 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4376 	set_opt(sb, POSIX_ACL);
4377 #endif
4378 	if (ext4_has_feature_fast_commit(sb))
4379 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4380 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4381 	if (ext4_has_metadata_csum(sb))
4382 		set_opt(sb, JOURNAL_CHECKSUM);
4383 
4384 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4385 		set_opt(sb, JOURNAL_DATA);
4386 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4387 		set_opt(sb, ORDERED_DATA);
4388 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4389 		set_opt(sb, WRITEBACK_DATA);
4390 
4391 	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
4392 		set_opt(sb, ERRORS_PANIC);
4393 	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
4394 		set_opt(sb, ERRORS_CONT);
4395 	else
4396 		set_opt(sb, ERRORS_RO);
4397 	/* block_validity enabled by default; disable with noblock_validity */
4398 	set_opt(sb, BLOCK_VALIDITY);
4399 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4400 		set_opt(sb, DISCARD);
4401 
4402 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4403 		set_opt(sb, BARRIER);
4404 
4405 	/*
4406 	 * enable delayed allocation by default
4407 	 * Use -o nodelalloc to turn it off
4408 	 */
4409 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4410 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4411 		set_opt(sb, DELALLOC);
4412 
4413 	if (sb->s_blocksize == PAGE_SIZE)
4414 		set_opt(sb, DIOREAD_NOLOCK);
4415 }
4416 
4417 static int ext4_handle_clustersize(struct super_block *sb)
4418 {
4419 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4420 	struct ext4_super_block *es = sbi->s_es;
4421 	int clustersize;
4422 
4423 	/* Handle clustersize */
4424 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4425 	if (ext4_has_feature_bigalloc(sb)) {
4426 		if (clustersize < sb->s_blocksize) {
4427 			ext4_msg(sb, KERN_ERR,
4428 				 "cluster size (%d) smaller than "
4429 				 "block size (%lu)", clustersize, sb->s_blocksize);
4430 			return -EINVAL;
4431 		}
4432 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4433 			le32_to_cpu(es->s_log_block_size);
4434 		sbi->s_clusters_per_group =
4435 			le32_to_cpu(es->s_clusters_per_group);
4436 		if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
4437 			ext4_msg(sb, KERN_ERR,
4438 				 "#clusters per group too big: %lu",
4439 				 sbi->s_clusters_per_group);
4440 			return -EINVAL;
4441 		}
4442 		if (sbi->s_blocks_per_group !=
4443 		    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
4444 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4445 				 "clusters per group (%lu) inconsistent",
4446 				 sbi->s_blocks_per_group,
4447 				 sbi->s_clusters_per_group);
4448 			return -EINVAL;
4449 		}
4450 	} else {
4451 		if (clustersize != sb->s_blocksize) {
4452 			ext4_msg(sb, KERN_ERR,
4453 				 "fragment/cluster size (%d) != "
4454 				 "block size (%lu)", clustersize, sb->s_blocksize);
4455 			return -EINVAL;
4456 		}
4457 		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
4458 			ext4_msg(sb, KERN_ERR,
4459 				 "#blocks per group too big: %lu",
4460 				 sbi->s_blocks_per_group);
4461 			return -EINVAL;
4462 		}
4463 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4464 		sbi->s_cluster_bits = 0;
4465 	}
4466 	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
4467 
4468 	/* Do we have standard group size of clustersize * 8 blocks ? */
4469 	if (sbi->s_blocks_per_group == clustersize << 3)
4470 		set_opt2(sb, STD_GROUP_SIZE);
4471 
4472 	return 0;
4473 }
4474 
4475 static void ext4_fast_commit_init(struct super_block *sb)
4476 {
4477 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4478 
4479 	/* Initialize fast commit stuff */
4480 	atomic_set(&sbi->s_fc_subtid, 0);
4481 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4482 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4483 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4484 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4485 	sbi->s_fc_bytes = 0;
4486 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4487 	sbi->s_fc_ineligible_tid = 0;
4488 	spin_lock_init(&sbi->s_fc_lock);
4489 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4490 	sbi->s_fc_replay_state.fc_regions = NULL;
4491 	sbi->s_fc_replay_state.fc_regions_size = 0;
4492 	sbi->s_fc_replay_state.fc_regions_used = 0;
4493 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4494 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4495 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4496 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4497 }
4498 
4499 static int ext4_inode_info_init(struct super_block *sb,
4500 				struct ext4_super_block *es)
4501 {
4502 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4503 
4504 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4505 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4506 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4507 	} else {
4508 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4509 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4510 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4511 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4512 				 sbi->s_first_ino);
4513 			return -EINVAL;
4514 		}
4515 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4516 		    (!is_power_of_2(sbi->s_inode_size)) ||
4517 		    (sbi->s_inode_size > sb->s_blocksize)) {
4518 			ext4_msg(sb, KERN_ERR,
4519 			       "unsupported inode size: %d",
4520 			       sbi->s_inode_size);
4521 			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
4522 			return -EINVAL;
4523 		}
4524 		/*
4525 		 * i_atime_extra is the last extra field available for
4526 		 * [acm]times in struct ext4_inode. Checking for that
4527 		 * field should suffice to ensure we have extra space
4528 		 * for all three.
4529 		 */
4530 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4531 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4532 			sb->s_time_gran = 1;
4533 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4534 		} else {
4535 			sb->s_time_gran = NSEC_PER_SEC;
4536 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4537 		}
4538 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4539 	}
4540 
4541 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4542 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4543 			EXT4_GOOD_OLD_INODE_SIZE;
4544 		if (ext4_has_feature_extra_isize(sb)) {
4545 			unsigned v, max = (sbi->s_inode_size -
4546 					   EXT4_GOOD_OLD_INODE_SIZE);
4547 
4548 			v = le16_to_cpu(es->s_want_extra_isize);
4549 			if (v > max) {
4550 				ext4_msg(sb, KERN_ERR,
4551 					 "bad s_want_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 			v = le16_to_cpu(es->s_min_extra_isize);
4558 			if (v > max) {
4559 				ext4_msg(sb, KERN_ERR,
4560 					 "bad s_min_extra_isize: %d", v);
4561 				return -EINVAL;
4562 			}
4563 			if (sbi->s_want_extra_isize < v)
4564 				sbi->s_want_extra_isize = v;
4565 		}
4566 	}
4567 
4568 	return 0;
4569 }
4570 
4571 #if IS_ENABLED(CONFIG_UNICODE)
4572 static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4573 {
4574 	const struct ext4_sb_encodings *encoding_info;
4575 	struct unicode_map *encoding;
4576 	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4577 
4578 	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
4579 		return 0;
4580 
4581 	encoding_info = ext4_sb_read_encoding(es);
4582 	if (!encoding_info) {
4583 		ext4_msg(sb, KERN_ERR,
4584 			"Encoding requested by superblock is unknown");
4585 		return -EINVAL;
4586 	}
4587 
4588 	encoding = utf8_load(encoding_info->version);
4589 	if (IS_ERR(encoding)) {
4590 		ext4_msg(sb, KERN_ERR,
4591 			"can't mount with superblock charset: %s-%u.%u.%u "
4592 			"not supported by the kernel. flags: 0x%x.",
4593 			encoding_info->name,
4594 			unicode_major(encoding_info->version),
4595 			unicode_minor(encoding_info->version),
4596 			unicode_rev(encoding_info->version),
4597 			encoding_flags);
4598 		return -EINVAL;
4599 	}
4600 	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4601 		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4602 		unicode_major(encoding_info->version),
4603 		unicode_minor(encoding_info->version),
4604 		unicode_rev(encoding_info->version),
4605 		encoding_flags);
4606 
4607 	sb->s_encoding = encoding;
4608 	sb->s_encoding_flags = encoding_flags;
4609 
4610 	return 0;
4611 }
4612 #else
4613 static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
4614 {
4615 	return 0;
4616 }
4617 #endif
4618 
4619 static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
4620 {
4621 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4622 
4623 	/* Warn if metadata_csum and gdt_csum are both set. */
4624 	if (ext4_has_feature_metadata_csum(sb) &&
4625 	    ext4_has_feature_gdt_csum(sb))
4626 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4627 			     "redundant flags; please run fsck.");
4628 
4629 	/* Check for a known checksum algorithm */
4630 	if (!ext4_verify_csum_type(sb, es)) {
4631 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4632 			 "unknown checksum algorithm.");
4633 		return -EINVAL;
4634 	}
4635 	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4636 				ext4_orphan_file_block_trigger);
4637 
4638 	/* Load the checksum driver */
4639 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4640 	if (IS_ERR(sbi->s_chksum_driver)) {
4641 		int ret = PTR_ERR(sbi->s_chksum_driver);
4642 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4643 		sbi->s_chksum_driver = NULL;
4644 		return ret;
4645 	}
4646 
4647 	/* Check superblock checksum */
4648 	if (!ext4_superblock_csum_verify(sb, es)) {
4649 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4650 			 "invalid superblock checksum.  Run e2fsck?");
4651 		return -EFSBADCRC;
4652 	}
4653 
4654 	/* Precompute checksum seed for all metadata */
4655 	if (ext4_has_feature_csum_seed(sb))
4656 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4657 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4658 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4659 					       sizeof(es->s_uuid));
4660 	return 0;
4661 }
4662 
4663 static int ext4_check_feature_compatibility(struct super_block *sb,
4664 					    struct ext4_super_block *es,
4665 					    int silent)
4666 {
4667 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4668 
4669 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4670 	    (ext4_has_compat_features(sb) ||
4671 	     ext4_has_ro_compat_features(sb) ||
4672 	     ext4_has_incompat_features(sb)))
4673 		ext4_msg(sb, KERN_WARNING,
4674 		       "feature flags set on rev 0 fs, "
4675 		       "running e2fsck is recommended");
4676 
4677 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4678 		set_opt2(sb, HURD_COMPAT);
4679 		if (ext4_has_feature_64bit(sb)) {
4680 			ext4_msg(sb, KERN_ERR,
4681 				 "The Hurd can't support 64-bit file systems");
4682 			return -EINVAL;
4683 		}
4684 
4685 		/*
4686 		 * ea_inode feature uses l_i_version field which is not
4687 		 * available in HURD_COMPAT mode.
4688 		 */
4689 		if (ext4_has_feature_ea_inode(sb)) {
4690 			ext4_msg(sb, KERN_ERR,
4691 				 "ea_inode feature is not supported for Hurd");
4692 			return -EINVAL;
4693 		}
4694 	}
4695 
4696 	if (IS_EXT2_SB(sb)) {
4697 		if (ext2_feature_set_ok(sb))
4698 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4699 				 "using the ext4 subsystem");
4700 		else {
4701 			/*
4702 			 * If we're probing be silent, if this looks like
4703 			 * it's actually an ext[34] filesystem.
4704 			 */
4705 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4706 				return -EINVAL;
4707 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4708 				 "to feature incompatibilities");
4709 			return -EINVAL;
4710 		}
4711 	}
4712 
4713 	if (IS_EXT3_SB(sb)) {
4714 		if (ext3_feature_set_ok(sb))
4715 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4716 				 "using the ext4 subsystem");
4717 		else {
4718 			/*
4719 			 * If we're probing be silent, if this looks like
4720 			 * it's actually an ext4 filesystem.
4721 			 */
4722 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4723 				return -EINVAL;
4724 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4725 				 "to feature incompatibilities");
4726 			return -EINVAL;
4727 		}
4728 	}
4729 
4730 	/*
4731 	 * Check feature flags regardless of the revision level, since we
4732 	 * previously didn't change the revision level when setting the flags,
4733 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4734 	 */
4735 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4736 		return -EINVAL;
4737 
4738 	if (sbi->s_daxdev) {
4739 		if (sb->s_blocksize == PAGE_SIZE)
4740 			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4741 		else
4742 			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4743 	}
4744 
4745 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4746 		if (ext4_has_feature_inline_data(sb)) {
4747 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4748 					" that may contain inline data");
4749 			return -EINVAL;
4750 		}
4751 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4752 			ext4_msg(sb, KERN_ERR,
4753 				"DAX unsupported by block device.");
4754 			return -EINVAL;
4755 		}
4756 	}
4757 
4758 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4759 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4760 			 es->s_encryption_level);
4761 		return -EINVAL;
4762 	}
4763 
4764 	return 0;
4765 }
4766 
4767 static int ext4_check_geometry(struct super_block *sb,
4768 			       struct ext4_super_block *es)
4769 {
4770 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4771 	__u64 blocks_count;
4772 	int err;
4773 
4774 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
4775 		ext4_msg(sb, KERN_ERR,
4776 			 "Number of reserved GDT blocks insanely large: %d",
4777 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4778 		return -EINVAL;
4779 	}
4780 	/*
4781 	 * Test whether we have more sectors than will fit in sector_t,
4782 	 * and whether the max offset is addressable by the page cache.
4783 	 */
4784 	err = generic_check_addressable(sb->s_blocksize_bits,
4785 					ext4_blocks_count(es));
4786 	if (err) {
4787 		ext4_msg(sb, KERN_ERR, "filesystem"
4788 			 " too large to mount safely on this system");
4789 		return err;
4790 	}
4791 
4792 	/* check blocks count against device size */
4793 	blocks_count = sb_bdev_nr_blocks(sb);
4794 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4795 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4796 		       "exceeds size of device (%llu blocks)",
4797 		       ext4_blocks_count(es), blocks_count);
4798 		return -EINVAL;
4799 	}
4800 
4801 	/*
4802 	 * It makes no sense for the first data block to be beyond the end
4803 	 * of the filesystem.
4804 	 */
4805 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4806 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4807 			 "block %u is beyond end of filesystem (%llu)",
4808 			 le32_to_cpu(es->s_first_data_block),
4809 			 ext4_blocks_count(es));
4810 		return -EINVAL;
4811 	}
4812 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4813 	    (sbi->s_cluster_ratio == 1)) {
4814 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4815 			 "block is 0 with a 1k block and cluster size");
4816 		return -EINVAL;
4817 	}
4818 
4819 	blocks_count = (ext4_blocks_count(es) -
4820 			le32_to_cpu(es->s_first_data_block) +
4821 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4822 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4823 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4824 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4825 		       "(block count %llu, first data block %u, "
4826 		       "blocks per group %lu)", blocks_count,
4827 		       ext4_blocks_count(es),
4828 		       le32_to_cpu(es->s_first_data_block),
4829 		       EXT4_BLOCKS_PER_GROUP(sb));
4830 		return -EINVAL;
4831 	}
4832 	sbi->s_groups_count = blocks_count;
4833 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4834 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4835 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4836 	    le32_to_cpu(es->s_inodes_count)) {
4837 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4838 			 le32_to_cpu(es->s_inodes_count),
4839 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4840 		return -EINVAL;
4841 	}
4842 
4843 	return 0;
4844 }
4845 
4846 static int ext4_group_desc_init(struct super_block *sb,
4847 				struct ext4_super_block *es,
4848 				ext4_fsblk_t logical_sb_block,
4849 				ext4_group_t *first_not_zeroed)
4850 {
4851 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4852 	unsigned int db_count;
4853 	ext4_fsblk_t block;
4854 	int i;
4855 
4856 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4857 		   EXT4_DESC_PER_BLOCK(sb);
4858 	if (ext4_has_feature_meta_bg(sb)) {
4859 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4860 			ext4_msg(sb, KERN_WARNING,
4861 				 "first meta block group too large: %u "
4862 				 "(group descriptor block count %u)",
4863 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4864 			return -EINVAL;
4865 		}
4866 	}
4867 	rcu_assign_pointer(sbi->s_group_desc,
4868 			   kvmalloc_array(db_count,
4869 					  sizeof(struct buffer_head *),
4870 					  GFP_KERNEL));
4871 	if (sbi->s_group_desc == NULL) {
4872 		ext4_msg(sb, KERN_ERR, "not enough memory");
4873 		return -ENOMEM;
4874 	}
4875 
4876 	bgl_lock_init(sbi->s_blockgroup_lock);
4877 
4878 	/* Pre-read the descriptors into the buffer cache */
4879 	for (i = 0; i < db_count; i++) {
4880 		block = descriptor_loc(sb, logical_sb_block, i);
4881 		ext4_sb_breadahead_unmovable(sb, block);
4882 	}
4883 
4884 	for (i = 0; i < db_count; i++) {
4885 		struct buffer_head *bh;
4886 
4887 		block = descriptor_loc(sb, logical_sb_block, i);
4888 		bh = ext4_sb_bread_unmovable(sb, block);
4889 		if (IS_ERR(bh)) {
4890 			ext4_msg(sb, KERN_ERR,
4891 			       "can't read group descriptor %d", i);
4892 			sbi->s_gdb_count = i;
4893 			return PTR_ERR(bh);
4894 		}
4895 		rcu_read_lock();
4896 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4897 		rcu_read_unlock();
4898 	}
4899 	sbi->s_gdb_count = db_count;
4900 	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
4901 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4902 		return -EFSCORRUPTED;
4903 	}
4904 
4905 	return 0;
4906 }
4907 
4908 static int ext4_load_and_init_journal(struct super_block *sb,
4909 				      struct ext4_super_block *es,
4910 				      struct ext4_fs_context *ctx)
4911 {
4912 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4913 	int err;
4914 
4915 	err = ext4_load_journal(sb, es, ctx->journal_devnum);
4916 	if (err)
4917 		return err;
4918 
4919 	if (ext4_has_feature_64bit(sb) &&
4920 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4921 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4922 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4923 		goto out;
4924 	}
4925 
4926 	if (!set_journal_csum_feature_set(sb)) {
4927 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4928 			 "feature set");
4929 		goto out;
4930 	}
4931 
4932 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4933 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4934 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4935 		ext4_msg(sb, KERN_ERR,
4936 			"Failed to set fast commit journal feature");
4937 		goto out;
4938 	}
4939 
4940 	/* We have now updated the journal if required, so we can
4941 	 * validate the data journaling mode. */
4942 	switch (test_opt(sb, DATA_FLAGS)) {
4943 	case 0:
4944 		/* No mode set, assume a default based on the journal
4945 		 * capabilities: ORDERED_DATA if the journal can
4946 		 * cope, else JOURNAL_DATA
4947 		 */
4948 		if (jbd2_journal_check_available_features
4949 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4950 			set_opt(sb, ORDERED_DATA);
4951 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4952 		} else {
4953 			set_opt(sb, JOURNAL_DATA);
4954 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4955 		}
4956 		break;
4957 
4958 	case EXT4_MOUNT_ORDERED_DATA:
4959 	case EXT4_MOUNT_WRITEBACK_DATA:
4960 		if (!jbd2_journal_check_available_features
4961 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4962 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4963 			       "requested data journaling mode");
4964 			goto out;
4965 		}
4966 		break;
4967 	default:
4968 		break;
4969 	}
4970 
4971 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4972 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4973 		ext4_msg(sb, KERN_ERR, "can't mount with "
4974 			"journal_async_commit in data=ordered mode");
4975 		goto out;
4976 	}
4977 
4978 	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
4979 
4980 	sbi->s_journal->j_submit_inode_data_buffers =
4981 		ext4_journal_submit_inode_data_buffers;
4982 	sbi->s_journal->j_finish_inode_data_buffers =
4983 		ext4_journal_finish_inode_data_buffers;
4984 
4985 	return 0;
4986 
4987 out:
4988 	/* flush s_sb_upd_work before destroying the journal. */
4989 	flush_work(&sbi->s_sb_upd_work);
4990 	jbd2_journal_destroy(sbi->s_journal);
4991 	sbi->s_journal = NULL;
4992 	return -EINVAL;
4993 }
4994 
4995 static int ext4_check_journal_data_mode(struct super_block *sb)
4996 {
4997 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4998 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
4999 			    "data=journal disables delayed allocation, "
5000 			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
5001 		/* can't mount with both data=journal and dioread_nolock. */
5002 		clear_opt(sb, DIOREAD_NOLOCK);
5003 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5004 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5005 			ext4_msg(sb, KERN_ERR, "can't mount with "
5006 				 "both data=journal and delalloc");
5007 			return -EINVAL;
5008 		}
5009 		if (test_opt(sb, DAX_ALWAYS)) {
5010 			ext4_msg(sb, KERN_ERR, "can't mount with "
5011 				 "both data=journal and dax");
5012 			return -EINVAL;
5013 		}
5014 		if (ext4_has_feature_encrypt(sb)) {
5015 			ext4_msg(sb, KERN_WARNING,
5016 				 "encrypted files will use data=ordered "
5017 				 "instead of data journaling mode");
5018 		}
5019 		if (test_opt(sb, DELALLOC))
5020 			clear_opt(sb, DELALLOC);
5021 	} else {
5022 		sb->s_iflags |= SB_I_CGROUPWB;
5023 	}
5024 
5025 	return 0;
5026 }
5027 
5028 static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
5029 			   int silent)
5030 {
5031 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5032 	struct ext4_super_block *es;
5033 	ext4_fsblk_t logical_sb_block;
5034 	unsigned long offset = 0;
5035 	struct buffer_head *bh;
5036 	int ret = -EINVAL;
5037 	int blocksize;
5038 
5039 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
5040 	if (!blocksize) {
5041 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
5042 		return -EINVAL;
5043 	}
5044 
5045 	/*
5046 	 * The ext4 superblock will not be buffer aligned for other than 1kB
5047 	 * block sizes.  We need to calculate the offset from buffer start.
5048 	 */
5049 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
5050 		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5051 		offset = do_div(logical_sb_block, blocksize);
5052 	} else {
5053 		logical_sb_block = sbi->s_sb_block;
5054 	}
5055 
5056 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5057 	if (IS_ERR(bh)) {
5058 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
5059 		return PTR_ERR(bh);
5060 	}
5061 	/*
5062 	 * Note: s_es must be initialized as soon as possible because
5063 	 *       some ext4 macro-instructions depend on its value
5064 	 */
5065 	es = (struct ext4_super_block *) (bh->b_data + offset);
5066 	sbi->s_es = es;
5067 	sb->s_magic = le16_to_cpu(es->s_magic);
5068 	if (sb->s_magic != EXT4_SUPER_MAGIC) {
5069 		if (!silent)
5070 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5071 		goto out;
5072 	}
5073 
5074 	if (le32_to_cpu(es->s_log_block_size) >
5075 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5076 		ext4_msg(sb, KERN_ERR,
5077 			 "Invalid log block size: %u",
5078 			 le32_to_cpu(es->s_log_block_size));
5079 		goto out;
5080 	}
5081 	if (le32_to_cpu(es->s_log_cluster_size) >
5082 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
5083 		ext4_msg(sb, KERN_ERR,
5084 			 "Invalid log cluster size: %u",
5085 			 le32_to_cpu(es->s_log_cluster_size));
5086 		goto out;
5087 	}
5088 
5089 	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
5090 
5091 	/*
5092 	 * If the default block size is not the same as the real block size,
5093 	 * we need to reload it.
5094 	 */
5095 	if (sb->s_blocksize == blocksize) {
5096 		*lsb = logical_sb_block;
5097 		sbi->s_sbh = bh;
5098 		return 0;
5099 	}
5100 
5101 	/*
5102 	 * bh must be released before kill_bdev(), otherwise
5103 	 * it won't be freed and its page also. kill_bdev()
5104 	 * is called by sb_set_blocksize().
5105 	 */
5106 	brelse(bh);
5107 	/* Validate the filesystem blocksize */
5108 	if (!sb_set_blocksize(sb, blocksize)) {
5109 		ext4_msg(sb, KERN_ERR, "bad block size %d",
5110 				blocksize);
5111 		bh = NULL;
5112 		goto out;
5113 	}
5114 
5115 	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
5116 	offset = do_div(logical_sb_block, blocksize);
5117 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
5118 	if (IS_ERR(bh)) {
5119 		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
5120 		ret = PTR_ERR(bh);
5121 		bh = NULL;
5122 		goto out;
5123 	}
5124 	es = (struct ext4_super_block *)(bh->b_data + offset);
5125 	sbi->s_es = es;
5126 	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
5127 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
5128 		goto out;
5129 	}
5130 	*lsb = logical_sb_block;
5131 	sbi->s_sbh = bh;
5132 	return 0;
5133 out:
5134 	brelse(bh);
5135 	return ret;
5136 }
5137 
5138 static void ext4_hash_info_init(struct super_block *sb)
5139 {
5140 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5141 	struct ext4_super_block *es = sbi->s_es;
5142 	unsigned int i;
5143 
5144 	for (i = 0; i < 4; i++)
5145 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
5146 
5147 	sbi->s_def_hash_version = es->s_def_hash_version;
5148 	if (ext4_has_feature_dir_index(sb)) {
5149 		i = le32_to_cpu(es->s_flags);
5150 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
5151 			sbi->s_hash_unsigned = 3;
5152 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
5153 #ifdef __CHAR_UNSIGNED__
5154 			if (!sb_rdonly(sb))
5155 				es->s_flags |=
5156 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
5157 			sbi->s_hash_unsigned = 3;
5158 #else
5159 			if (!sb_rdonly(sb))
5160 				es->s_flags |=
5161 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
5162 #endif
5163 		}
5164 	}
5165 }
5166 
5167 static int ext4_block_group_meta_init(struct super_block *sb, int silent)
5168 {
5169 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5170 	struct ext4_super_block *es = sbi->s_es;
5171 	int has_huge_files;
5172 
5173 	has_huge_files = ext4_has_feature_huge_file(sb);
5174 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
5175 						      has_huge_files);
5176 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
5177 
5178 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
5179 	if (ext4_has_feature_64bit(sb)) {
5180 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
5181 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
5182 		    !is_power_of_2(sbi->s_desc_size)) {
5183 			ext4_msg(sb, KERN_ERR,
5184 			       "unsupported descriptor size %lu",
5185 			       sbi->s_desc_size);
5186 			return -EINVAL;
5187 		}
5188 	} else
5189 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
5190 
5191 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
5192 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
5193 
5194 	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
5195 	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
5196 		if (!silent)
5197 			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5198 		return -EINVAL;
5199 	}
5200 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
5201 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
5202 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
5203 			 sbi->s_inodes_per_group);
5204 		return -EINVAL;
5205 	}
5206 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
5207 					sbi->s_inodes_per_block;
5208 	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
5209 	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
5210 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
5211 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
5212 
5213 	return 0;
5214 }
5215 
5216 /*
5217  * It's hard to get stripe aligned blocks if stripe is not aligned with
5218  * cluster, just disable stripe and alert user to simplify code and avoid
5219  * stripe aligned allocation which will rarely succeed.
5220  */
5221 static bool ext4_is_stripe_incompatible(struct super_block *sb, unsigned long stripe)
5222 {
5223 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5224 	return (stripe > 0 && sbi->s_cluster_ratio > 1 &&
5225 		stripe % sbi->s_cluster_ratio != 0);
5226 }
5227 
5228 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
5229 {
5230 	struct ext4_super_block *es = NULL;
5231 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5232 	ext4_fsblk_t logical_sb_block;
5233 	struct inode *root;
5234 	int needs_recovery;
5235 	int err;
5236 	ext4_group_t first_not_zeroed;
5237 	struct ext4_fs_context *ctx = fc->fs_private;
5238 	int silent = fc->sb_flags & SB_SILENT;
5239 
5240 	/* Set defaults for the variables that will be set during parsing */
5241 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
5242 		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5243 
5244 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
5245 	sbi->s_sectors_written_start =
5246 		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
5247 
5248 	err = ext4_load_super(sb, &logical_sb_block, silent);
5249 	if (err)
5250 		goto out_fail;
5251 
5252 	es = sbi->s_es;
5253 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
5254 
5255 	err = ext4_init_metadata_csum(sb, es);
5256 	if (err)
5257 		goto failed_mount;
5258 
5259 	ext4_set_def_opts(sb, es);
5260 
5261 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
5262 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
5263 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
5264 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
5265 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
5266 
5267 	/*
5268 	 * set default s_li_wait_mult for lazyinit, for the case there is
5269 	 * no mount option specified.
5270 	 */
5271 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
5272 
5273 	err = ext4_inode_info_init(sb, es);
5274 	if (err)
5275 		goto failed_mount;
5276 
5277 	err = parse_apply_sb_mount_options(sb, ctx);
5278 	if (err < 0)
5279 		goto failed_mount;
5280 
5281 	sbi->s_def_mount_opt = sbi->s_mount_opt;
5282 	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
5283 
5284 	err = ext4_check_opt_consistency(fc, sb);
5285 	if (err < 0)
5286 		goto failed_mount;
5287 
5288 	ext4_apply_options(fc, sb);
5289 
5290 	err = ext4_encoding_init(sb, es);
5291 	if (err)
5292 		goto failed_mount;
5293 
5294 	err = ext4_check_journal_data_mode(sb);
5295 	if (err)
5296 		goto failed_mount;
5297 
5298 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5299 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5300 
5301 	/* i_version is always enabled now */
5302 	sb->s_flags |= SB_I_VERSION;
5303 
5304 	err = ext4_check_feature_compatibility(sb, es, silent);
5305 	if (err)
5306 		goto failed_mount;
5307 
5308 	err = ext4_block_group_meta_init(sb, silent);
5309 	if (err)
5310 		goto failed_mount;
5311 
5312 	ext4_hash_info_init(sb);
5313 
5314 	err = ext4_handle_clustersize(sb);
5315 	if (err)
5316 		goto failed_mount;
5317 
5318 	err = ext4_check_geometry(sb, es);
5319 	if (err)
5320 		goto failed_mount;
5321 
5322 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5323 	spin_lock_init(&sbi->s_error_lock);
5324 	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
5325 
5326 	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
5327 	if (err)
5328 		goto failed_mount3;
5329 
5330 	err = ext4_es_register_shrinker(sbi);
5331 	if (err)
5332 		goto failed_mount3;
5333 
5334 	sbi->s_stripe = ext4_get_stripe_size(sbi);
5335 	if (ext4_is_stripe_incompatible(sb, sbi->s_stripe)) {
5336 		ext4_msg(sb, KERN_WARNING,
5337 			 "stripe (%lu) is not aligned with cluster size (%u), "
5338 			 "stripe is disabled",
5339 			 sbi->s_stripe, sbi->s_cluster_ratio);
5340 		sbi->s_stripe = 0;
5341 	}
5342 	sbi->s_extent_max_zeroout_kb = 32;
5343 
5344 	/*
5345 	 * set up enough so that it can read an inode
5346 	 */
5347 	sb->s_op = &ext4_sops;
5348 	sb->s_export_op = &ext4_export_ops;
5349 	sb->s_xattr = ext4_xattr_handlers;
5350 #ifdef CONFIG_FS_ENCRYPTION
5351 	sb->s_cop = &ext4_cryptops;
5352 #endif
5353 #ifdef CONFIG_FS_VERITY
5354 	sb->s_vop = &ext4_verityops;
5355 #endif
5356 #ifdef CONFIG_QUOTA
5357 	sb->dq_op = &ext4_quota_operations;
5358 	if (ext4_has_feature_quota(sb))
5359 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
5360 	else
5361 		sb->s_qcop = &ext4_qctl_operations;
5362 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5363 #endif
5364 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5365 
5366 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5367 	mutex_init(&sbi->s_orphan_lock);
5368 
5369 	ext4_fast_commit_init(sb);
5370 
5371 	sb->s_root = NULL;
5372 
5373 	needs_recovery = (es->s_last_orphan != 0 ||
5374 			  ext4_has_feature_orphan_present(sb) ||
5375 			  ext4_has_feature_journal_needs_recovery(sb));
5376 
5377 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
5378 		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
5379 		if (err)
5380 			goto failed_mount3a;
5381 	}
5382 
5383 	err = -EINVAL;
5384 	/*
5385 	 * The first inode we look at is the journal inode.  Don't try
5386 	 * root first: it may be modified in the journal!
5387 	 */
5388 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5389 		err = ext4_load_and_init_journal(sb, es, ctx);
5390 		if (err)
5391 			goto failed_mount3a;
5392 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5393 		   ext4_has_feature_journal_needs_recovery(sb)) {
5394 		ext4_msg(sb, KERN_ERR, "required journal recovery "
5395 		       "suppressed and not mounted read-only");
5396 		goto failed_mount3a;
5397 	} else {
5398 		/* Nojournal mode, all journal mount options are illegal */
5399 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5400 			ext4_msg(sb, KERN_ERR, "can't mount with "
5401 				 "journal_async_commit, fs mounted w/o journal");
5402 			goto failed_mount3a;
5403 		}
5404 
5405 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5406 			ext4_msg(sb, KERN_ERR, "can't mount with "
5407 				 "journal_checksum, fs mounted w/o journal");
5408 			goto failed_mount3a;
5409 		}
5410 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5411 			ext4_msg(sb, KERN_ERR, "can't mount with "
5412 				 "commit=%lu, fs mounted w/o journal",
5413 				 sbi->s_commit_interval / HZ);
5414 			goto failed_mount3a;
5415 		}
5416 		if (EXT4_MOUNT_DATA_FLAGS &
5417 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5418 			ext4_msg(sb, KERN_ERR, "can't mount with "
5419 				 "data=, fs mounted w/o journal");
5420 			goto failed_mount3a;
5421 		}
5422 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5423 		clear_opt(sb, JOURNAL_CHECKSUM);
5424 		clear_opt(sb, DATA_FLAGS);
5425 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
5426 		sbi->s_journal = NULL;
5427 		needs_recovery = 0;
5428 	}
5429 
5430 	if (!test_opt(sb, NO_MBCACHE)) {
5431 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
5432 		if (!sbi->s_ea_block_cache) {
5433 			ext4_msg(sb, KERN_ERR,
5434 				 "Failed to create ea_block_cache");
5435 			err = -EINVAL;
5436 			goto failed_mount_wq;
5437 		}
5438 
5439 		if (ext4_has_feature_ea_inode(sb)) {
5440 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5441 			if (!sbi->s_ea_inode_cache) {
5442 				ext4_msg(sb, KERN_ERR,
5443 					 "Failed to create ea_inode_cache");
5444 				err = -EINVAL;
5445 				goto failed_mount_wq;
5446 			}
5447 		}
5448 	}
5449 
5450 	/*
5451 	 * Get the # of file system overhead blocks from the
5452 	 * superblock if present.
5453 	 */
5454 	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5455 	/* ignore the precalculated value if it is ridiculous */
5456 	if (sbi->s_overhead > ext4_blocks_count(es))
5457 		sbi->s_overhead = 0;
5458 	/*
5459 	 * If the bigalloc feature is not enabled recalculating the
5460 	 * overhead doesn't take long, so we might as well just redo
5461 	 * it to make sure we are using the correct value.
5462 	 */
5463 	if (!ext4_has_feature_bigalloc(sb))
5464 		sbi->s_overhead = 0;
5465 	if (sbi->s_overhead == 0) {
5466 		err = ext4_calculate_overhead(sb);
5467 		if (err)
5468 			goto failed_mount_wq;
5469 	}
5470 
5471 	/*
5472 	 * The maximum number of concurrent works can be high and
5473 	 * concurrency isn't really necessary.  Limit it to 1.
5474 	 */
5475 	EXT4_SB(sb)->rsv_conversion_wq =
5476 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5477 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
5478 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5479 		err = -ENOMEM;
5480 		goto failed_mount4;
5481 	}
5482 
5483 	/*
5484 	 * The jbd2_journal_load will have done any necessary log recovery,
5485 	 * so we can safely mount the rest of the filesystem now.
5486 	 */
5487 
5488 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5489 	if (IS_ERR(root)) {
5490 		ext4_msg(sb, KERN_ERR, "get root inode failed");
5491 		err = PTR_ERR(root);
5492 		root = NULL;
5493 		goto failed_mount4;
5494 	}
5495 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5496 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5497 		iput(root);
5498 		err = -EFSCORRUPTED;
5499 		goto failed_mount4;
5500 	}
5501 
5502 	sb->s_root = d_make_root(root);
5503 	if (!sb->s_root) {
5504 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
5505 		err = -ENOMEM;
5506 		goto failed_mount4;
5507 	}
5508 
5509 	err = ext4_setup_super(sb, es, sb_rdonly(sb));
5510 	if (err == -EROFS) {
5511 		sb->s_flags |= SB_RDONLY;
5512 	} else if (err)
5513 		goto failed_mount4a;
5514 
5515 	ext4_set_resv_clusters(sb);
5516 
5517 	if (test_opt(sb, BLOCK_VALIDITY)) {
5518 		err = ext4_setup_system_zone(sb);
5519 		if (err) {
5520 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5521 				 "zone (%d)", err);
5522 			goto failed_mount4a;
5523 		}
5524 	}
5525 	ext4_fc_replay_cleanup(sb);
5526 
5527 	ext4_ext_init(sb);
5528 
5529 	/*
5530 	 * Enable optimize_scan if number of groups is > threshold. This can be
5531 	 * turned off by passing "mb_optimize_scan=0". This can also be
5532 	 * turned on forcefully by passing "mb_optimize_scan=1".
5533 	 */
5534 	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5535 		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5536 			set_opt2(sb, MB_OPTIMIZE_SCAN);
5537 		else
5538 			clear_opt2(sb, MB_OPTIMIZE_SCAN);
5539 	}
5540 
5541 	err = ext4_mb_init(sb);
5542 	if (err) {
5543 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5544 			 err);
5545 		goto failed_mount5;
5546 	}
5547 
5548 	/*
5549 	 * We can only set up the journal commit callback once
5550 	 * mballoc is initialized
5551 	 */
5552 	if (sbi->s_journal)
5553 		sbi->s_journal->j_commit_callback =
5554 			ext4_journal_commit_callback;
5555 
5556 	err = ext4_percpu_param_init(sbi);
5557 	if (err)
5558 		goto failed_mount6;
5559 
5560 	if (ext4_has_feature_flex_bg(sb))
5561 		if (!ext4_fill_flex_info(sb)) {
5562 			ext4_msg(sb, KERN_ERR,
5563 			       "unable to initialize "
5564 			       "flex_bg meta info!");
5565 			err = -ENOMEM;
5566 			goto failed_mount6;
5567 		}
5568 
5569 	err = ext4_register_li_request(sb, first_not_zeroed);
5570 	if (err)
5571 		goto failed_mount6;
5572 
5573 	err = ext4_init_orphan_info(sb);
5574 	if (err)
5575 		goto failed_mount7;
5576 #ifdef CONFIG_QUOTA
5577 	/* Enable quota usage during mount. */
5578 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5579 		err = ext4_enable_quotas(sb);
5580 		if (err)
5581 			goto failed_mount8;
5582 	}
5583 #endif  /* CONFIG_QUOTA */
5584 
5585 	/*
5586 	 * Save the original bdev mapping's wb_err value which could be
5587 	 * used to detect the metadata async write error.
5588 	 */
5589 	spin_lock_init(&sbi->s_bdev_wb_lock);
5590 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5591 				 &sbi->s_bdev_wb_err);
5592 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5593 	ext4_orphan_cleanup(sb, es);
5594 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5595 	/*
5596 	 * Update the checksum after updating free space/inode counters and
5597 	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5598 	 * checksum in the buffer cache until it is written out and
5599 	 * e2fsprogs programs trying to open a file system immediately
5600 	 * after it is mounted can fail.
5601 	 */
5602 	ext4_superblock_csum_set(sb);
5603 	if (needs_recovery) {
5604 		ext4_msg(sb, KERN_INFO, "recovery complete");
5605 		err = ext4_mark_recovery_complete(sb, es);
5606 		if (err)
5607 			goto failed_mount9;
5608 	}
5609 
5610 	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5611 		ext4_msg(sb, KERN_WARNING,
5612 			 "mounting with \"discard\" option, but the device does not support discard");
5613 
5614 	if (es->s_error_count)
5615 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5616 
5617 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5618 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5619 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5620 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5621 	atomic_set(&sbi->s_warning_count, 0);
5622 	atomic_set(&sbi->s_msg_count, 0);
5623 
5624 	/* Register sysfs after all initializations are complete. */
5625 	err = ext4_register_sysfs(sb);
5626 	if (err)
5627 		goto failed_mount9;
5628 
5629 	return 0;
5630 
5631 failed_mount9:
5632 	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
5633 failed_mount8: __maybe_unused
5634 	ext4_release_orphan_info(sb);
5635 failed_mount7:
5636 	ext4_unregister_li_request(sb);
5637 failed_mount6:
5638 	ext4_mb_release(sb);
5639 	ext4_flex_groups_free(sbi);
5640 	ext4_percpu_param_destroy(sbi);
5641 failed_mount5:
5642 	ext4_ext_release(sb);
5643 	ext4_release_system_zone(sb);
5644 failed_mount4a:
5645 	dput(sb->s_root);
5646 	sb->s_root = NULL;
5647 failed_mount4:
5648 	ext4_msg(sb, KERN_ERR, "mount failed");
5649 	if (EXT4_SB(sb)->rsv_conversion_wq)
5650 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5651 failed_mount_wq:
5652 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5653 	sbi->s_ea_inode_cache = NULL;
5654 
5655 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5656 	sbi->s_ea_block_cache = NULL;
5657 
5658 	if (sbi->s_journal) {
5659 		/* flush s_sb_upd_work before journal destroy. */
5660 		flush_work(&sbi->s_sb_upd_work);
5661 		jbd2_journal_destroy(sbi->s_journal);
5662 		sbi->s_journal = NULL;
5663 	}
5664 failed_mount3a:
5665 	ext4_es_unregister_shrinker(sbi);
5666 failed_mount3:
5667 	/* flush s_sb_upd_work before sbi destroy */
5668 	flush_work(&sbi->s_sb_upd_work);
5669 	ext4_stop_mmpd(sbi);
5670 	del_timer_sync(&sbi->s_err_report);
5671 	ext4_group_desc_free(sbi);
5672 failed_mount:
5673 	if (sbi->s_chksum_driver)
5674 		crypto_free_shash(sbi->s_chksum_driver);
5675 
5676 #if IS_ENABLED(CONFIG_UNICODE)
5677 	utf8_unload(sb->s_encoding);
5678 #endif
5679 
5680 #ifdef CONFIG_QUOTA
5681 	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
5682 		kfree(get_qf_name(sb, sbi, i));
5683 #endif
5684 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5685 	brelse(sbi->s_sbh);
5686 	if (sbi->s_journal_bdev) {
5687 		invalidate_bdev(sbi->s_journal_bdev);
5688 		blkdev_put(sbi->s_journal_bdev, sb);
5689 	}
5690 out_fail:
5691 	invalidate_bdev(sb->s_bdev);
5692 	sb->s_fs_info = NULL;
5693 	return err;
5694 }
5695 
5696 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5697 {
5698 	struct ext4_fs_context *ctx = fc->fs_private;
5699 	struct ext4_sb_info *sbi;
5700 	const char *descr;
5701 	int ret;
5702 
5703 	sbi = ext4_alloc_sbi(sb);
5704 	if (!sbi)
5705 		return -ENOMEM;
5706 
5707 	fc->s_fs_info = sbi;
5708 
5709 	/* Cleanup superblock name */
5710 	strreplace(sb->s_id, '/', '!');
5711 
5712 	sbi->s_sb_block = 1;	/* Default super block location */
5713 	if (ctx->spec & EXT4_SPEC_s_sb_block)
5714 		sbi->s_sb_block = ctx->s_sb_block;
5715 
5716 	ret = __ext4_fill_super(fc, sb);
5717 	if (ret < 0)
5718 		goto free_sbi;
5719 
5720 	if (sbi->s_journal) {
5721 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5722 			descr = " journalled data mode";
5723 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5724 			descr = " ordered data mode";
5725 		else
5726 			descr = " writeback data mode";
5727 	} else
5728 		descr = "out journal";
5729 
5730 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5731 		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
5732 			 "Quota mode: %s.", &sb->s_uuid,
5733 			 sb_rdonly(sb) ? "ro" : "r/w", descr,
5734 			 ext4_quota_mode(sb));
5735 
5736 	/* Update the s_overhead_clusters if necessary */
5737 	ext4_update_overhead(sb, false);
5738 	return 0;
5739 
5740 free_sbi:
5741 	ext4_free_sbi(sbi);
5742 	fc->s_fs_info = NULL;
5743 	return ret;
5744 }
5745 
5746 static int ext4_get_tree(struct fs_context *fc)
5747 {
5748 	return get_tree_bdev(fc, ext4_fill_super);
5749 }
5750 
5751 /*
5752  * Setup any per-fs journal parameters now.  We'll do this both on
5753  * initial mount, once the journal has been initialised but before we've
5754  * done any recovery; and again on any subsequent remount.
5755  */
5756 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5757 {
5758 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5759 
5760 	journal->j_commit_interval = sbi->s_commit_interval;
5761 	journal->j_min_batch_time = sbi->s_min_batch_time;
5762 	journal->j_max_batch_time = sbi->s_max_batch_time;
5763 	ext4_fc_init(sb, journal);
5764 
5765 	write_lock(&journal->j_state_lock);
5766 	if (test_opt(sb, BARRIER))
5767 		journal->j_flags |= JBD2_BARRIER;
5768 	else
5769 		journal->j_flags &= ~JBD2_BARRIER;
5770 	if (test_opt(sb, DATA_ERR_ABORT))
5771 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5772 	else
5773 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5774 	/*
5775 	 * Always enable journal cycle record option, letting the journal
5776 	 * records log transactions continuously between each mount.
5777 	 */
5778 	journal->j_flags |= JBD2_CYCLE_RECORD;
5779 	write_unlock(&journal->j_state_lock);
5780 }
5781 
5782 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5783 					     unsigned int journal_inum)
5784 {
5785 	struct inode *journal_inode;
5786 
5787 	/*
5788 	 * Test for the existence of a valid inode on disk.  Bad things
5789 	 * happen if we iget() an unused inode, as the subsequent iput()
5790 	 * will try to delete it.
5791 	 */
5792 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5793 	if (IS_ERR(journal_inode)) {
5794 		ext4_msg(sb, KERN_ERR, "no journal found");
5795 		return ERR_CAST(journal_inode);
5796 	}
5797 	if (!journal_inode->i_nlink) {
5798 		make_bad_inode(journal_inode);
5799 		iput(journal_inode);
5800 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5801 		return ERR_PTR(-EFSCORRUPTED);
5802 	}
5803 	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
5804 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5805 		iput(journal_inode);
5806 		return ERR_PTR(-EFSCORRUPTED);
5807 	}
5808 
5809 	ext4_debug("Journal inode found at %p: %lld bytes\n",
5810 		  journal_inode, journal_inode->i_size);
5811 	return journal_inode;
5812 }
5813 
5814 static int ext4_journal_bmap(journal_t *journal, sector_t *block)
5815 {
5816 	struct ext4_map_blocks map;
5817 	int ret;
5818 
5819 	if (journal->j_inode == NULL)
5820 		return 0;
5821 
5822 	map.m_lblk = *block;
5823 	map.m_len = 1;
5824 	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
5825 	if (ret <= 0) {
5826 		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
5827 			 "journal bmap failed: block %llu ret %d\n",
5828 			 *block, ret);
5829 		jbd2_journal_abort(journal, ret ? ret : -EIO);
5830 		return ret;
5831 	}
5832 	*block = map.m_pblk;
5833 	return 0;
5834 }
5835 
5836 static journal_t *ext4_open_inode_journal(struct super_block *sb,
5837 					  unsigned int journal_inum)
5838 {
5839 	struct inode *journal_inode;
5840 	journal_t *journal;
5841 
5842 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5843 	if (IS_ERR(journal_inode))
5844 		return ERR_CAST(journal_inode);
5845 
5846 	journal = jbd2_journal_init_inode(journal_inode);
5847 	if (IS_ERR(journal)) {
5848 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5849 		iput(journal_inode);
5850 		return ERR_CAST(journal);
5851 	}
5852 	journal->j_private = sb;
5853 	journal->j_bmap = ext4_journal_bmap;
5854 	ext4_init_journal_params(sb, journal);
5855 	return journal;
5856 }
5857 
5858 static struct block_device *ext4_get_journal_blkdev(struct super_block *sb,
5859 					dev_t j_dev, ext4_fsblk_t *j_start,
5860 					ext4_fsblk_t *j_len)
5861 {
5862 	struct buffer_head *bh;
5863 	struct block_device *bdev;
5864 	int hblock, blocksize;
5865 	ext4_fsblk_t sb_block;
5866 	unsigned long offset;
5867 	struct ext4_super_block *es;
5868 	int errno;
5869 
5870 	/* see get_tree_bdev why this is needed and safe */
5871 	up_write(&sb->s_umount);
5872 	bdev = blkdev_get_by_dev(j_dev, BLK_OPEN_READ | BLK_OPEN_WRITE, sb,
5873 				 &fs_holder_ops);
5874 	down_write(&sb->s_umount);
5875 	if (IS_ERR(bdev)) {
5876 		ext4_msg(sb, KERN_ERR,
5877 			 "failed to open journal device unknown-block(%u,%u) %ld",
5878 			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev));
5879 		return ERR_CAST(bdev);
5880 	}
5881 
5882 	blocksize = sb->s_blocksize;
5883 	hblock = bdev_logical_block_size(bdev);
5884 	if (blocksize < hblock) {
5885 		ext4_msg(sb, KERN_ERR,
5886 			"blocksize too small for journal device");
5887 		errno = -EINVAL;
5888 		goto out_bdev;
5889 	}
5890 
5891 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5892 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5893 	set_blocksize(bdev, blocksize);
5894 	bh = __bread(bdev, sb_block, blocksize);
5895 	if (!bh) {
5896 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5897 		       "external journal");
5898 		errno = -EINVAL;
5899 		goto out_bdev;
5900 	}
5901 
5902 	es = (struct ext4_super_block *) (bh->b_data + offset);
5903 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5904 	    !(le32_to_cpu(es->s_feature_incompat) &
5905 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5906 		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
5907 		errno = -EFSCORRUPTED;
5908 		goto out_bh;
5909 	}
5910 
5911 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5912 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5913 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5914 		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
5915 		errno = -EFSCORRUPTED;
5916 		goto out_bh;
5917 	}
5918 
5919 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5920 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5921 		errno = -EFSCORRUPTED;
5922 		goto out_bh;
5923 	}
5924 
5925 	*j_start = sb_block + 1;
5926 	*j_len = ext4_blocks_count(es);
5927 	brelse(bh);
5928 	return bdev;
5929 
5930 out_bh:
5931 	brelse(bh);
5932 out_bdev:
5933 	blkdev_put(bdev, sb);
5934 	return ERR_PTR(errno);
5935 }
5936 
5937 static journal_t *ext4_open_dev_journal(struct super_block *sb,
5938 					dev_t j_dev)
5939 {
5940 	journal_t *journal;
5941 	ext4_fsblk_t j_start;
5942 	ext4_fsblk_t j_len;
5943 	struct block_device *journal_bdev;
5944 	int errno = 0;
5945 
5946 	journal_bdev = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
5947 	if (IS_ERR(journal_bdev))
5948 		return ERR_CAST(journal_bdev);
5949 
5950 	journal = jbd2_journal_init_dev(journal_bdev, sb->s_bdev, j_start,
5951 					j_len, sb->s_blocksize);
5952 	if (IS_ERR(journal)) {
5953 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5954 		errno = PTR_ERR(journal);
5955 		goto out_bdev;
5956 	}
5957 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5958 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5959 					"user (unsupported) - %d",
5960 			be32_to_cpu(journal->j_superblock->s_nr_users));
5961 		errno = -EINVAL;
5962 		goto out_journal;
5963 	}
5964 	journal->j_private = sb;
5965 	EXT4_SB(sb)->s_journal_bdev = journal_bdev;
5966 	ext4_init_journal_params(sb, journal);
5967 	return journal;
5968 
5969 out_journal:
5970 	jbd2_journal_destroy(journal);
5971 out_bdev:
5972 	blkdev_put(journal_bdev, sb);
5973 	return ERR_PTR(errno);
5974 }
5975 
5976 static int ext4_load_journal(struct super_block *sb,
5977 			     struct ext4_super_block *es,
5978 			     unsigned long journal_devnum)
5979 {
5980 	journal_t *journal;
5981 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5982 	dev_t journal_dev;
5983 	int err = 0;
5984 	int really_read_only;
5985 	int journal_dev_ro;
5986 
5987 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5988 		return -EFSCORRUPTED;
5989 
5990 	if (journal_devnum &&
5991 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5992 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5993 			"numbers have changed");
5994 		journal_dev = new_decode_dev(journal_devnum);
5995 	} else
5996 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5997 
5998 	if (journal_inum && journal_dev) {
5999 		ext4_msg(sb, KERN_ERR,
6000 			 "filesystem has both journal inode and journal device!");
6001 		return -EINVAL;
6002 	}
6003 
6004 	if (journal_inum) {
6005 		journal = ext4_open_inode_journal(sb, journal_inum);
6006 		if (IS_ERR(journal))
6007 			return PTR_ERR(journal);
6008 	} else {
6009 		journal = ext4_open_dev_journal(sb, journal_dev);
6010 		if (IS_ERR(journal))
6011 			return PTR_ERR(journal);
6012 	}
6013 
6014 	journal_dev_ro = bdev_read_only(journal->j_dev);
6015 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
6016 
6017 	if (journal_dev_ro && !sb_rdonly(sb)) {
6018 		ext4_msg(sb, KERN_ERR,
6019 			 "journal device read-only, try mounting with '-o ro'");
6020 		err = -EROFS;
6021 		goto err_out;
6022 	}
6023 
6024 	/*
6025 	 * Are we loading a blank journal or performing recovery after a
6026 	 * crash?  For recovery, we need to check in advance whether we
6027 	 * can get read-write access to the device.
6028 	 */
6029 	if (ext4_has_feature_journal_needs_recovery(sb)) {
6030 		if (sb_rdonly(sb)) {
6031 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
6032 					"required on readonly filesystem");
6033 			if (really_read_only) {
6034 				ext4_msg(sb, KERN_ERR, "write access "
6035 					"unavailable, cannot proceed "
6036 					"(try mounting with noload)");
6037 				err = -EROFS;
6038 				goto err_out;
6039 			}
6040 			ext4_msg(sb, KERN_INFO, "write access will "
6041 			       "be enabled during recovery");
6042 		}
6043 	}
6044 
6045 	if (!(journal->j_flags & JBD2_BARRIER))
6046 		ext4_msg(sb, KERN_INFO, "barriers disabled");
6047 
6048 	if (!ext4_has_feature_journal_needs_recovery(sb))
6049 		err = jbd2_journal_wipe(journal, !really_read_only);
6050 	if (!err) {
6051 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
6052 		__le16 orig_state;
6053 		bool changed = false;
6054 
6055 		if (save)
6056 			memcpy(save, ((char *) es) +
6057 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
6058 		err = jbd2_journal_load(journal);
6059 		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
6060 				   save, EXT4_S_ERR_LEN)) {
6061 			memcpy(((char *) es) + EXT4_S_ERR_START,
6062 			       save, EXT4_S_ERR_LEN);
6063 			changed = true;
6064 		}
6065 		kfree(save);
6066 		orig_state = es->s_state;
6067 		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
6068 					   EXT4_ERROR_FS);
6069 		if (orig_state != es->s_state)
6070 			changed = true;
6071 		/* Write out restored error information to the superblock */
6072 		if (changed && !really_read_only) {
6073 			int err2;
6074 			err2 = ext4_commit_super(sb);
6075 			err = err ? : err2;
6076 		}
6077 	}
6078 
6079 	if (err) {
6080 		ext4_msg(sb, KERN_ERR, "error loading journal");
6081 		goto err_out;
6082 	}
6083 
6084 	EXT4_SB(sb)->s_journal = journal;
6085 	err = ext4_clear_journal_err(sb, es);
6086 	if (err) {
6087 		EXT4_SB(sb)->s_journal = NULL;
6088 		jbd2_journal_destroy(journal);
6089 		return err;
6090 	}
6091 
6092 	if (!really_read_only && journal_devnum &&
6093 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
6094 		es->s_journal_dev = cpu_to_le32(journal_devnum);
6095 		ext4_commit_super(sb);
6096 	}
6097 	if (!really_read_only && journal_inum &&
6098 	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
6099 		es->s_journal_inum = cpu_to_le32(journal_inum);
6100 		ext4_commit_super(sb);
6101 	}
6102 
6103 	return 0;
6104 
6105 err_out:
6106 	jbd2_journal_destroy(journal);
6107 	return err;
6108 }
6109 
6110 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
6111 static void ext4_update_super(struct super_block *sb)
6112 {
6113 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6114 	struct ext4_super_block *es = sbi->s_es;
6115 	struct buffer_head *sbh = sbi->s_sbh;
6116 
6117 	lock_buffer(sbh);
6118 	/*
6119 	 * If the file system is mounted read-only, don't update the
6120 	 * superblock write time.  This avoids updating the superblock
6121 	 * write time when we are mounting the root file system
6122 	 * read/only but we need to replay the journal; at that point,
6123 	 * for people who are east of GMT and who make their clock
6124 	 * tick in localtime for Windows bug-for-bug compatibility,
6125 	 * the clock is set in the future, and this will cause e2fsck
6126 	 * to complain and force a full file system check.
6127 	 */
6128 	if (!sb_rdonly(sb))
6129 		ext4_update_tstamp(es, s_wtime);
6130 	es->s_kbytes_written =
6131 		cpu_to_le64(sbi->s_kbytes_written +
6132 		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6133 		      sbi->s_sectors_written_start) >> 1));
6134 	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6135 		ext4_free_blocks_count_set(es,
6136 			EXT4_C2B(sbi, percpu_counter_sum_positive(
6137 				&sbi->s_freeclusters_counter)));
6138 	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6139 		es->s_free_inodes_count =
6140 			cpu_to_le32(percpu_counter_sum_positive(
6141 				&sbi->s_freeinodes_counter));
6142 	/* Copy error information to the on-disk superblock */
6143 	spin_lock(&sbi->s_error_lock);
6144 	if (sbi->s_add_error_count > 0) {
6145 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6146 		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6147 			__ext4_update_tstamp(&es->s_first_error_time,
6148 					     &es->s_first_error_time_hi,
6149 					     sbi->s_first_error_time);
6150 			strncpy(es->s_first_error_func, sbi->s_first_error_func,
6151 				sizeof(es->s_first_error_func));
6152 			es->s_first_error_line =
6153 				cpu_to_le32(sbi->s_first_error_line);
6154 			es->s_first_error_ino =
6155 				cpu_to_le32(sbi->s_first_error_ino);
6156 			es->s_first_error_block =
6157 				cpu_to_le64(sbi->s_first_error_block);
6158 			es->s_first_error_errcode =
6159 				ext4_errno_to_code(sbi->s_first_error_code);
6160 		}
6161 		__ext4_update_tstamp(&es->s_last_error_time,
6162 				     &es->s_last_error_time_hi,
6163 				     sbi->s_last_error_time);
6164 		strncpy(es->s_last_error_func, sbi->s_last_error_func,
6165 			sizeof(es->s_last_error_func));
6166 		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6167 		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6168 		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6169 		es->s_last_error_errcode =
6170 				ext4_errno_to_code(sbi->s_last_error_code);
6171 		/*
6172 		 * Start the daily error reporting function if it hasn't been
6173 		 * started already
6174 		 */
6175 		if (!es->s_error_count)
6176 			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6177 		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6178 		sbi->s_add_error_count = 0;
6179 	}
6180 	spin_unlock(&sbi->s_error_lock);
6181 
6182 	ext4_superblock_csum_set(sb);
6183 	unlock_buffer(sbh);
6184 }
6185 
6186 static int ext4_commit_super(struct super_block *sb)
6187 {
6188 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6189 
6190 	if (!sbh)
6191 		return -EINVAL;
6192 	if (block_device_ejected(sb))
6193 		return -ENODEV;
6194 
6195 	ext4_update_super(sb);
6196 
6197 	lock_buffer(sbh);
6198 	/* Buffer got discarded which means block device got invalidated */
6199 	if (!buffer_mapped(sbh)) {
6200 		unlock_buffer(sbh);
6201 		return -EIO;
6202 	}
6203 
6204 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6205 		/*
6206 		 * Oh, dear.  A previous attempt to write the
6207 		 * superblock failed.  This could happen because the
6208 		 * USB device was yanked out.  Or it could happen to
6209 		 * be a transient write error and maybe the block will
6210 		 * be remapped.  Nothing we can do but to retry the
6211 		 * write and hope for the best.
6212 		 */
6213 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
6214 		       "superblock detected");
6215 		clear_buffer_write_io_error(sbh);
6216 		set_buffer_uptodate(sbh);
6217 	}
6218 	get_bh(sbh);
6219 	/* Clear potential dirty bit if it was journalled update */
6220 	clear_buffer_dirty(sbh);
6221 	sbh->b_end_io = end_buffer_write_sync;
6222 	submit_bh(REQ_OP_WRITE | REQ_SYNC |
6223 		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
6224 	wait_on_buffer(sbh);
6225 	if (buffer_write_io_error(sbh)) {
6226 		ext4_msg(sb, KERN_ERR, "I/O error while writing "
6227 		       "superblock");
6228 		clear_buffer_write_io_error(sbh);
6229 		set_buffer_uptodate(sbh);
6230 		return -EIO;
6231 	}
6232 	return 0;
6233 }
6234 
6235 /*
6236  * Have we just finished recovery?  If so, and if we are mounting (or
6237  * remounting) the filesystem readonly, then we will end up with a
6238  * consistent fs on disk.  Record that fact.
6239  */
6240 static int ext4_mark_recovery_complete(struct super_block *sb,
6241 				       struct ext4_super_block *es)
6242 {
6243 	int err;
6244 	journal_t *journal = EXT4_SB(sb)->s_journal;
6245 
6246 	if (!ext4_has_feature_journal(sb)) {
6247 		if (journal != NULL) {
6248 			ext4_error(sb, "Journal got removed while the fs was "
6249 				   "mounted!");
6250 			return -EFSCORRUPTED;
6251 		}
6252 		return 0;
6253 	}
6254 	jbd2_journal_lock_updates(journal);
6255 	err = jbd2_journal_flush(journal, 0);
6256 	if (err < 0)
6257 		goto out;
6258 
6259 	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6260 	    ext4_has_feature_orphan_present(sb))) {
6261 		if (!ext4_orphan_file_empty(sb)) {
6262 			ext4_error(sb, "Orphan file not empty on read-only fs.");
6263 			err = -EFSCORRUPTED;
6264 			goto out;
6265 		}
6266 		ext4_clear_feature_journal_needs_recovery(sb);
6267 		ext4_clear_feature_orphan_present(sb);
6268 		ext4_commit_super(sb);
6269 	}
6270 out:
6271 	jbd2_journal_unlock_updates(journal);
6272 	return err;
6273 }
6274 
6275 /*
6276  * If we are mounting (or read-write remounting) a filesystem whose journal
6277  * has recorded an error from a previous lifetime, move that error to the
6278  * main filesystem now.
6279  */
6280 static int ext4_clear_journal_err(struct super_block *sb,
6281 				   struct ext4_super_block *es)
6282 {
6283 	journal_t *journal;
6284 	int j_errno;
6285 	const char *errstr;
6286 
6287 	if (!ext4_has_feature_journal(sb)) {
6288 		ext4_error(sb, "Journal got removed while the fs was mounted!");
6289 		return -EFSCORRUPTED;
6290 	}
6291 
6292 	journal = EXT4_SB(sb)->s_journal;
6293 
6294 	/*
6295 	 * Now check for any error status which may have been recorded in the
6296 	 * journal by a prior ext4_error() or ext4_abort()
6297 	 */
6298 
6299 	j_errno = jbd2_journal_errno(journal);
6300 	if (j_errno) {
6301 		char nbuf[16];
6302 
6303 		errstr = ext4_decode_error(sb, j_errno, nbuf);
6304 		ext4_warning(sb, "Filesystem error recorded "
6305 			     "from previous mount: %s", errstr);
6306 
6307 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6308 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6309 		j_errno = ext4_commit_super(sb);
6310 		if (j_errno)
6311 			return j_errno;
6312 		ext4_warning(sb, "Marked fs in need of filesystem check.");
6313 
6314 		jbd2_journal_clear_err(journal);
6315 		jbd2_journal_update_sb_errno(journal);
6316 	}
6317 	return 0;
6318 }
6319 
6320 /*
6321  * Force the running and committing transactions to commit,
6322  * and wait on the commit.
6323  */
6324 int ext4_force_commit(struct super_block *sb)
6325 {
6326 	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
6327 }
6328 
6329 static int ext4_sync_fs(struct super_block *sb, int wait)
6330 {
6331 	int ret = 0;
6332 	tid_t target;
6333 	bool needs_barrier = false;
6334 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6335 
6336 	if (unlikely(ext4_forced_shutdown(sb)))
6337 		return 0;
6338 
6339 	trace_ext4_sync_fs(sb, wait);
6340 	flush_workqueue(sbi->rsv_conversion_wq);
6341 	/*
6342 	 * Writeback quota in non-journalled quota case - journalled quota has
6343 	 * no dirty dquots
6344 	 */
6345 	dquot_writeback_dquots(sb, -1);
6346 	/*
6347 	 * Data writeback is possible w/o journal transaction, so barrier must
6348 	 * being sent at the end of the function. But we can skip it if
6349 	 * transaction_commit will do it for us.
6350 	 */
6351 	if (sbi->s_journal) {
6352 		target = jbd2_get_latest_transaction(sbi->s_journal);
6353 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6354 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6355 			needs_barrier = true;
6356 
6357 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6358 			if (wait)
6359 				ret = jbd2_log_wait_commit(sbi->s_journal,
6360 							   target);
6361 		}
6362 	} else if (wait && test_opt(sb, BARRIER))
6363 		needs_barrier = true;
6364 	if (needs_barrier) {
6365 		int err;
6366 		err = blkdev_issue_flush(sb->s_bdev);
6367 		if (!ret)
6368 			ret = err;
6369 	}
6370 
6371 	return ret;
6372 }
6373 
6374 /*
6375  * LVM calls this function before a (read-only) snapshot is created.  This
6376  * gives us a chance to flush the journal completely and mark the fs clean.
6377  *
6378  * Note that only this function cannot bring a filesystem to be in a clean
6379  * state independently. It relies on upper layer to stop all data & metadata
6380  * modifications.
6381  */
6382 static int ext4_freeze(struct super_block *sb)
6383 {
6384 	int error = 0;
6385 	journal_t *journal = EXT4_SB(sb)->s_journal;
6386 
6387 	if (journal) {
6388 		/* Now we set up the journal barrier. */
6389 		jbd2_journal_lock_updates(journal);
6390 
6391 		/*
6392 		 * Don't clear the needs_recovery flag if we failed to
6393 		 * flush the journal.
6394 		 */
6395 		error = jbd2_journal_flush(journal, 0);
6396 		if (error < 0)
6397 			goto out;
6398 
6399 		/* Journal blocked and flushed, clear needs_recovery flag. */
6400 		ext4_clear_feature_journal_needs_recovery(sb);
6401 		if (ext4_orphan_file_empty(sb))
6402 			ext4_clear_feature_orphan_present(sb);
6403 	}
6404 
6405 	error = ext4_commit_super(sb);
6406 out:
6407 	if (journal)
6408 		/* we rely on upper layer to stop further updates */
6409 		jbd2_journal_unlock_updates(journal);
6410 	return error;
6411 }
6412 
6413 /*
6414  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6415  * flag here, even though the filesystem is not technically dirty yet.
6416  */
6417 static int ext4_unfreeze(struct super_block *sb)
6418 {
6419 	if (ext4_forced_shutdown(sb))
6420 		return 0;
6421 
6422 	if (EXT4_SB(sb)->s_journal) {
6423 		/* Reset the needs_recovery flag before the fs is unlocked. */
6424 		ext4_set_feature_journal_needs_recovery(sb);
6425 		if (ext4_has_feature_orphan_file(sb))
6426 			ext4_set_feature_orphan_present(sb);
6427 	}
6428 
6429 	ext4_commit_super(sb);
6430 	return 0;
6431 }
6432 
6433 /*
6434  * Structure to save mount options for ext4_remount's benefit
6435  */
6436 struct ext4_mount_options {
6437 	unsigned long s_mount_opt;
6438 	unsigned long s_mount_opt2;
6439 	kuid_t s_resuid;
6440 	kgid_t s_resgid;
6441 	unsigned long s_commit_interval;
6442 	u32 s_min_batch_time, s_max_batch_time;
6443 #ifdef CONFIG_QUOTA
6444 	int s_jquota_fmt;
6445 	char *s_qf_names[EXT4_MAXQUOTAS];
6446 #endif
6447 };
6448 
6449 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6450 {
6451 	struct ext4_fs_context *ctx = fc->fs_private;
6452 	struct ext4_super_block *es;
6453 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6454 	unsigned long old_sb_flags;
6455 	struct ext4_mount_options old_opts;
6456 	ext4_group_t g;
6457 	int err = 0;
6458 	int alloc_ctx;
6459 #ifdef CONFIG_QUOTA
6460 	int enable_quota = 0;
6461 	int i, j;
6462 	char *to_free[EXT4_MAXQUOTAS];
6463 #endif
6464 
6465 
6466 	/* Store the original options */
6467 	old_sb_flags = sb->s_flags;
6468 	old_opts.s_mount_opt = sbi->s_mount_opt;
6469 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6470 	old_opts.s_resuid = sbi->s_resuid;
6471 	old_opts.s_resgid = sbi->s_resgid;
6472 	old_opts.s_commit_interval = sbi->s_commit_interval;
6473 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
6474 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
6475 #ifdef CONFIG_QUOTA
6476 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6477 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6478 		if (sbi->s_qf_names[i]) {
6479 			char *qf_name = get_qf_name(sb, sbi, i);
6480 
6481 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6482 			if (!old_opts.s_qf_names[i]) {
6483 				for (j = 0; j < i; j++)
6484 					kfree(old_opts.s_qf_names[j]);
6485 				return -ENOMEM;
6486 			}
6487 		} else
6488 			old_opts.s_qf_names[i] = NULL;
6489 #endif
6490 	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6491 		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6492 			ctx->journal_ioprio =
6493 				sbi->s_journal->j_task->io_context->ioprio;
6494 		else
6495 			ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6496 
6497 	}
6498 
6499 	if ((ctx->spec & EXT4_SPEC_s_stripe) &&
6500 	    ext4_is_stripe_incompatible(sb, ctx->s_stripe)) {
6501 		ext4_msg(sb, KERN_WARNING,
6502 			 "stripe (%lu) is not aligned with cluster size (%u), "
6503 			 "stripe is disabled",
6504 			 ctx->s_stripe, sbi->s_cluster_ratio);
6505 		ctx->s_stripe = 0;
6506 	}
6507 
6508 	/*
6509 	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
6510 	 * two calls to ext4_should_dioread_nolock() to return inconsistent
6511 	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
6512 	 * here s_writepages_rwsem to avoid race between writepages ops and
6513 	 * remount.
6514 	 */
6515 	alloc_ctx = ext4_writepages_down_write(sb);
6516 	ext4_apply_options(fc, sb);
6517 	ext4_writepages_up_write(sb, alloc_ctx);
6518 
6519 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6520 	    test_opt(sb, JOURNAL_CHECKSUM)) {
6521 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6522 			 "during remount not supported; ignoring");
6523 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6524 	}
6525 
6526 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6527 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6528 			ext4_msg(sb, KERN_ERR, "can't mount with "
6529 				 "both data=journal and delalloc");
6530 			err = -EINVAL;
6531 			goto restore_opts;
6532 		}
6533 		if (test_opt(sb, DIOREAD_NOLOCK)) {
6534 			ext4_msg(sb, KERN_ERR, "can't mount with "
6535 				 "both data=journal and dioread_nolock");
6536 			err = -EINVAL;
6537 			goto restore_opts;
6538 		}
6539 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6540 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6541 			ext4_msg(sb, KERN_ERR, "can't mount with "
6542 				"journal_async_commit in data=ordered mode");
6543 			err = -EINVAL;
6544 			goto restore_opts;
6545 		}
6546 	}
6547 
6548 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6549 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6550 		err = -EINVAL;
6551 		goto restore_opts;
6552 	}
6553 
6554 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6555 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6556 
6557 	es = sbi->s_es;
6558 
6559 	if (sbi->s_journal) {
6560 		ext4_init_journal_params(sb, sbi->s_journal);
6561 		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6562 	}
6563 
6564 	/* Flush outstanding errors before changing fs state */
6565 	flush_work(&sbi->s_sb_upd_work);
6566 
6567 	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6568 		if (ext4_forced_shutdown(sb)) {
6569 			err = -EROFS;
6570 			goto restore_opts;
6571 		}
6572 
6573 		if (fc->sb_flags & SB_RDONLY) {
6574 			err = sync_filesystem(sb);
6575 			if (err < 0)
6576 				goto restore_opts;
6577 			err = dquot_suspend(sb, -1);
6578 			if (err < 0)
6579 				goto restore_opts;
6580 
6581 			/*
6582 			 * First of all, the unconditional stuff we have to do
6583 			 * to disable replay of the journal when we next remount
6584 			 */
6585 			sb->s_flags |= SB_RDONLY;
6586 
6587 			/*
6588 			 * OK, test if we are remounting a valid rw partition
6589 			 * readonly, and if so set the rdonly flag and then
6590 			 * mark the partition as valid again.
6591 			 */
6592 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6593 			    (sbi->s_mount_state & EXT4_VALID_FS))
6594 				es->s_state = cpu_to_le16(sbi->s_mount_state);
6595 
6596 			if (sbi->s_journal) {
6597 				/*
6598 				 * We let remount-ro finish even if marking fs
6599 				 * as clean failed...
6600 				 */
6601 				ext4_mark_recovery_complete(sb, es);
6602 			}
6603 		} else {
6604 			/* Make sure we can mount this feature set readwrite */
6605 			if (ext4_has_feature_readonly(sb) ||
6606 			    !ext4_feature_set_ok(sb, 0)) {
6607 				err = -EROFS;
6608 				goto restore_opts;
6609 			}
6610 			/*
6611 			 * Make sure the group descriptor checksums
6612 			 * are sane.  If they aren't, refuse to remount r/w.
6613 			 */
6614 			for (g = 0; g < sbi->s_groups_count; g++) {
6615 				struct ext4_group_desc *gdp =
6616 					ext4_get_group_desc(sb, g, NULL);
6617 
6618 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6619 					ext4_msg(sb, KERN_ERR,
6620 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
6621 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6622 					       le16_to_cpu(gdp->bg_checksum));
6623 					err = -EFSBADCRC;
6624 					goto restore_opts;
6625 				}
6626 			}
6627 
6628 			/*
6629 			 * If we have an unprocessed orphan list hanging
6630 			 * around from a previously readonly bdev mount,
6631 			 * require a full umount/remount for now.
6632 			 */
6633 			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6634 				ext4_msg(sb, KERN_WARNING, "Couldn't "
6635 				       "remount RDWR because of unprocessed "
6636 				       "orphan inode list.  Please "
6637 				       "umount/remount instead");
6638 				err = -EINVAL;
6639 				goto restore_opts;
6640 			}
6641 
6642 			/*
6643 			 * Mounting a RDONLY partition read-write, so reread
6644 			 * and store the current valid flag.  (It may have
6645 			 * been changed by e2fsck since we originally mounted
6646 			 * the partition.)
6647 			 */
6648 			if (sbi->s_journal) {
6649 				err = ext4_clear_journal_err(sb, es);
6650 				if (err)
6651 					goto restore_opts;
6652 			}
6653 			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6654 					      ~EXT4_FC_REPLAY);
6655 
6656 			err = ext4_setup_super(sb, es, 0);
6657 			if (err)
6658 				goto restore_opts;
6659 
6660 			sb->s_flags &= ~SB_RDONLY;
6661 			if (ext4_has_feature_mmp(sb)) {
6662 				err = ext4_multi_mount_protect(sb,
6663 						le64_to_cpu(es->s_mmp_block));
6664 				if (err)
6665 					goto restore_opts;
6666 			}
6667 #ifdef CONFIG_QUOTA
6668 			enable_quota = 1;
6669 #endif
6670 		}
6671 	}
6672 
6673 	/*
6674 	 * Handle creation of system zone data early because it can fail.
6675 	 * Releasing of existing data is done when we are sure remount will
6676 	 * succeed.
6677 	 */
6678 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6679 		err = ext4_setup_system_zone(sb);
6680 		if (err)
6681 			goto restore_opts;
6682 	}
6683 
6684 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6685 		err = ext4_commit_super(sb);
6686 		if (err)
6687 			goto restore_opts;
6688 	}
6689 
6690 #ifdef CONFIG_QUOTA
6691 	if (enable_quota) {
6692 		if (sb_any_quota_suspended(sb))
6693 			dquot_resume(sb, -1);
6694 		else if (ext4_has_feature_quota(sb)) {
6695 			err = ext4_enable_quotas(sb);
6696 			if (err)
6697 				goto restore_opts;
6698 		}
6699 	}
6700 	/* Release old quota file names */
6701 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6702 		kfree(old_opts.s_qf_names[i]);
6703 #endif
6704 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6705 		ext4_release_system_zone(sb);
6706 
6707 	/*
6708 	 * Reinitialize lazy itable initialization thread based on
6709 	 * current settings
6710 	 */
6711 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6712 		ext4_unregister_li_request(sb);
6713 	else {
6714 		ext4_group_t first_not_zeroed;
6715 		first_not_zeroed = ext4_has_uninit_itable(sb);
6716 		ext4_register_li_request(sb, first_not_zeroed);
6717 	}
6718 
6719 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6720 		ext4_stop_mmpd(sbi);
6721 
6722 	/*
6723 	 * Handle aborting the filesystem as the last thing during remount to
6724 	 * avoid obsure errors during remount when some option changes fail to
6725 	 * apply due to shutdown filesystem.
6726 	 */
6727 	if (test_opt2(sb, ABORT))
6728 		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6729 
6730 	return 0;
6731 
6732 restore_opts:
6733 	/*
6734 	 * If there was a failing r/w to ro transition, we may need to
6735 	 * re-enable quota
6736 	 */
6737 	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
6738 	    sb_any_quota_suspended(sb))
6739 		dquot_resume(sb, -1);
6740 
6741 	alloc_ctx = ext4_writepages_down_write(sb);
6742 	sb->s_flags = old_sb_flags;
6743 	sbi->s_mount_opt = old_opts.s_mount_opt;
6744 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6745 	sbi->s_resuid = old_opts.s_resuid;
6746 	sbi->s_resgid = old_opts.s_resgid;
6747 	sbi->s_commit_interval = old_opts.s_commit_interval;
6748 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6749 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6750 	ext4_writepages_up_write(sb, alloc_ctx);
6751 
6752 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6753 		ext4_release_system_zone(sb);
6754 #ifdef CONFIG_QUOTA
6755 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6756 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6757 		to_free[i] = get_qf_name(sb, sbi, i);
6758 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6759 	}
6760 	synchronize_rcu();
6761 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6762 		kfree(to_free[i]);
6763 #endif
6764 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6765 		ext4_stop_mmpd(sbi);
6766 	return err;
6767 }
6768 
6769 static int ext4_reconfigure(struct fs_context *fc)
6770 {
6771 	struct super_block *sb = fc->root->d_sb;
6772 	int ret;
6773 
6774 	fc->s_fs_info = EXT4_SB(sb);
6775 
6776 	ret = ext4_check_opt_consistency(fc, sb);
6777 	if (ret < 0)
6778 		return ret;
6779 
6780 	ret = __ext4_remount(fc, sb);
6781 	if (ret < 0)
6782 		return ret;
6783 
6784 	ext4_msg(sb, KERN_INFO, "re-mounted %pU %s. Quota mode: %s.",
6785 		 &sb->s_uuid, sb_rdonly(sb) ? "ro" : "r/w",
6786 		 ext4_quota_mode(sb));
6787 
6788 	return 0;
6789 }
6790 
6791 #ifdef CONFIG_QUOTA
6792 static int ext4_statfs_project(struct super_block *sb,
6793 			       kprojid_t projid, struct kstatfs *buf)
6794 {
6795 	struct kqid qid;
6796 	struct dquot *dquot;
6797 	u64 limit;
6798 	u64 curblock;
6799 
6800 	qid = make_kqid_projid(projid);
6801 	dquot = dqget(sb, qid);
6802 	if (IS_ERR(dquot))
6803 		return PTR_ERR(dquot);
6804 	spin_lock(&dquot->dq_dqb_lock);
6805 
6806 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6807 			     dquot->dq_dqb.dqb_bhardlimit);
6808 	limit >>= sb->s_blocksize_bits;
6809 
6810 	if (limit && buf->f_blocks > limit) {
6811 		curblock = (dquot->dq_dqb.dqb_curspace +
6812 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6813 		buf->f_blocks = limit;
6814 		buf->f_bfree = buf->f_bavail =
6815 			(buf->f_blocks > curblock) ?
6816 			 (buf->f_blocks - curblock) : 0;
6817 	}
6818 
6819 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6820 			     dquot->dq_dqb.dqb_ihardlimit);
6821 	if (limit && buf->f_files > limit) {
6822 		buf->f_files = limit;
6823 		buf->f_ffree =
6824 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6825 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6826 	}
6827 
6828 	spin_unlock(&dquot->dq_dqb_lock);
6829 	dqput(dquot);
6830 	return 0;
6831 }
6832 #endif
6833 
6834 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6835 {
6836 	struct super_block *sb = dentry->d_sb;
6837 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6838 	struct ext4_super_block *es = sbi->s_es;
6839 	ext4_fsblk_t overhead = 0, resv_blocks;
6840 	s64 bfree;
6841 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6842 
6843 	if (!test_opt(sb, MINIX_DF))
6844 		overhead = sbi->s_overhead;
6845 
6846 	buf->f_type = EXT4_SUPER_MAGIC;
6847 	buf->f_bsize = sb->s_blocksize;
6848 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6849 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6850 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6851 	/* prevent underflow in case that few free space is available */
6852 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6853 	buf->f_bavail = buf->f_bfree -
6854 			(ext4_r_blocks_count(es) + resv_blocks);
6855 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6856 		buf->f_bavail = 0;
6857 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6858 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6859 	buf->f_namelen = EXT4_NAME_LEN;
6860 	buf->f_fsid = uuid_to_fsid(es->s_uuid);
6861 
6862 #ifdef CONFIG_QUOTA
6863 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6864 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6865 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6866 #endif
6867 	return 0;
6868 }
6869 
6870 
6871 #ifdef CONFIG_QUOTA
6872 
6873 /*
6874  * Helper functions so that transaction is started before we acquire dqio_sem
6875  * to keep correct lock ordering of transaction > dqio_sem
6876  */
6877 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6878 {
6879 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6880 }
6881 
6882 static int ext4_write_dquot(struct dquot *dquot)
6883 {
6884 	int ret, err;
6885 	handle_t *handle;
6886 	struct inode *inode;
6887 
6888 	inode = dquot_to_inode(dquot);
6889 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6890 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6891 	if (IS_ERR(handle))
6892 		return PTR_ERR(handle);
6893 	ret = dquot_commit(dquot);
6894 	if (ret < 0)
6895 		ext4_error_err(dquot->dq_sb, -ret,
6896 			       "Failed to commit dquot type %d",
6897 			       dquot->dq_id.type);
6898 	err = ext4_journal_stop(handle);
6899 	if (!ret)
6900 		ret = err;
6901 	return ret;
6902 }
6903 
6904 static int ext4_acquire_dquot(struct dquot *dquot)
6905 {
6906 	int ret, err;
6907 	handle_t *handle;
6908 
6909 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6910 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6911 	if (IS_ERR(handle))
6912 		return PTR_ERR(handle);
6913 	ret = dquot_acquire(dquot);
6914 	if (ret < 0)
6915 		ext4_error_err(dquot->dq_sb, -ret,
6916 			      "Failed to acquire dquot type %d",
6917 			      dquot->dq_id.type);
6918 	err = ext4_journal_stop(handle);
6919 	if (!ret)
6920 		ret = err;
6921 	return ret;
6922 }
6923 
6924 static int ext4_release_dquot(struct dquot *dquot)
6925 {
6926 	int ret, err;
6927 	handle_t *handle;
6928 
6929 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6930 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6931 	if (IS_ERR(handle)) {
6932 		/* Release dquot anyway to avoid endless cycle in dqput() */
6933 		dquot_release(dquot);
6934 		return PTR_ERR(handle);
6935 	}
6936 	ret = dquot_release(dquot);
6937 	if (ret < 0)
6938 		ext4_error_err(dquot->dq_sb, -ret,
6939 			       "Failed to release dquot type %d",
6940 			       dquot->dq_id.type);
6941 	err = ext4_journal_stop(handle);
6942 	if (!ret)
6943 		ret = err;
6944 	return ret;
6945 }
6946 
6947 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6948 {
6949 	struct super_block *sb = dquot->dq_sb;
6950 
6951 	if (ext4_is_quota_journalled(sb)) {
6952 		dquot_mark_dquot_dirty(dquot);
6953 		return ext4_write_dquot(dquot);
6954 	} else {
6955 		return dquot_mark_dquot_dirty(dquot);
6956 	}
6957 }
6958 
6959 static int ext4_write_info(struct super_block *sb, int type)
6960 {
6961 	int ret, err;
6962 	handle_t *handle;
6963 
6964 	/* Data block + inode block */
6965 	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
6966 	if (IS_ERR(handle))
6967 		return PTR_ERR(handle);
6968 	ret = dquot_commit_info(sb, type);
6969 	err = ext4_journal_stop(handle);
6970 	if (!ret)
6971 		ret = err;
6972 	return ret;
6973 }
6974 
6975 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6976 {
6977 	struct ext4_inode_info *ei = EXT4_I(inode);
6978 
6979 	/* The first argument of lockdep_set_subclass has to be
6980 	 * *exactly* the same as the argument to init_rwsem() --- in
6981 	 * this case, in init_once() --- or lockdep gets unhappy
6982 	 * because the name of the lock is set using the
6983 	 * stringification of the argument to init_rwsem().
6984 	 */
6985 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6986 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6987 }
6988 
6989 /*
6990  * Standard function to be called on quota_on
6991  */
6992 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6993 			 const struct path *path)
6994 {
6995 	int err;
6996 
6997 	if (!test_opt(sb, QUOTA))
6998 		return -EINVAL;
6999 
7000 	/* Quotafile not on the same filesystem? */
7001 	if (path->dentry->d_sb != sb)
7002 		return -EXDEV;
7003 
7004 	/* Quota already enabled for this file? */
7005 	if (IS_NOQUOTA(d_inode(path->dentry)))
7006 		return -EBUSY;
7007 
7008 	/* Journaling quota? */
7009 	if (EXT4_SB(sb)->s_qf_names[type]) {
7010 		/* Quotafile not in fs root? */
7011 		if (path->dentry->d_parent != sb->s_root)
7012 			ext4_msg(sb, KERN_WARNING,
7013 				"Quota file not on filesystem root. "
7014 				"Journaled quota will not work");
7015 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
7016 	} else {
7017 		/*
7018 		 * Clear the flag just in case mount options changed since
7019 		 * last time.
7020 		 */
7021 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
7022 	}
7023 
7024 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
7025 	err = dquot_quota_on(sb, type, format_id, path);
7026 	if (!err) {
7027 		struct inode *inode = d_inode(path->dentry);
7028 		handle_t *handle;
7029 
7030 		/*
7031 		 * Set inode flags to prevent userspace from messing with quota
7032 		 * files. If this fails, we return success anyway since quotas
7033 		 * are already enabled and this is not a hard failure.
7034 		 */
7035 		inode_lock(inode);
7036 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7037 		if (IS_ERR(handle))
7038 			goto unlock_inode;
7039 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
7040 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
7041 				S_NOATIME | S_IMMUTABLE);
7042 		err = ext4_mark_inode_dirty(handle, inode);
7043 		ext4_journal_stop(handle);
7044 	unlock_inode:
7045 		inode_unlock(inode);
7046 		if (err)
7047 			dquot_quota_off(sb, type);
7048 	}
7049 	if (err)
7050 		lockdep_set_quota_inode(path->dentry->d_inode,
7051 					     I_DATA_SEM_NORMAL);
7052 	return err;
7053 }
7054 
7055 static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
7056 {
7057 	switch (type) {
7058 	case USRQUOTA:
7059 		return qf_inum == EXT4_USR_QUOTA_INO;
7060 	case GRPQUOTA:
7061 		return qf_inum == EXT4_GRP_QUOTA_INO;
7062 	case PRJQUOTA:
7063 		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
7064 	default:
7065 		BUG();
7066 	}
7067 }
7068 
7069 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
7070 			     unsigned int flags)
7071 {
7072 	int err;
7073 	struct inode *qf_inode;
7074 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7075 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7076 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7077 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7078 	};
7079 
7080 	BUG_ON(!ext4_has_feature_quota(sb));
7081 
7082 	if (!qf_inums[type])
7083 		return -EPERM;
7084 
7085 	if (!ext4_check_quota_inum(type, qf_inums[type])) {
7086 		ext4_error(sb, "Bad quota inum: %lu, type: %d",
7087 				qf_inums[type], type);
7088 		return -EUCLEAN;
7089 	}
7090 
7091 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
7092 	if (IS_ERR(qf_inode)) {
7093 		ext4_error(sb, "Bad quota inode: %lu, type: %d",
7094 				qf_inums[type], type);
7095 		return PTR_ERR(qf_inode);
7096 	}
7097 
7098 	/* Don't account quota for quota files to avoid recursion */
7099 	qf_inode->i_flags |= S_NOQUOTA;
7100 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
7101 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
7102 	if (err)
7103 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
7104 	iput(qf_inode);
7105 
7106 	return err;
7107 }
7108 
7109 /* Enable usage tracking for all quota types. */
7110 int ext4_enable_quotas(struct super_block *sb)
7111 {
7112 	int type, err = 0;
7113 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
7114 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
7115 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
7116 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
7117 	};
7118 	bool quota_mopt[EXT4_MAXQUOTAS] = {
7119 		test_opt(sb, USRQUOTA),
7120 		test_opt(sb, GRPQUOTA),
7121 		test_opt(sb, PRJQUOTA),
7122 	};
7123 
7124 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
7125 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
7126 		if (qf_inums[type]) {
7127 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
7128 				DQUOT_USAGE_ENABLED |
7129 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
7130 			if (err) {
7131 				ext4_warning(sb,
7132 					"Failed to enable quota tracking "
7133 					"(type=%d, err=%d, ino=%lu). "
7134 					"Please run e2fsck to fix.", type,
7135 					err, qf_inums[type]);
7136 
7137 				ext4_quotas_off(sb, type);
7138 				return err;
7139 			}
7140 		}
7141 	}
7142 	return 0;
7143 }
7144 
7145 static int ext4_quota_off(struct super_block *sb, int type)
7146 {
7147 	struct inode *inode = sb_dqopt(sb)->files[type];
7148 	handle_t *handle;
7149 	int err;
7150 
7151 	/* Force all delayed allocation blocks to be allocated.
7152 	 * Caller already holds s_umount sem */
7153 	if (test_opt(sb, DELALLOC))
7154 		sync_filesystem(sb);
7155 
7156 	if (!inode || !igrab(inode))
7157 		goto out;
7158 
7159 	err = dquot_quota_off(sb, type);
7160 	if (err || ext4_has_feature_quota(sb))
7161 		goto out_put;
7162 	/*
7163 	 * When the filesystem was remounted read-only first, we cannot cleanup
7164 	 * inode flags here. Bad luck but people should be using QUOTA feature
7165 	 * these days anyway.
7166 	 */
7167 	if (sb_rdonly(sb))
7168 		goto out_put;
7169 
7170 	inode_lock(inode);
7171 	/*
7172 	 * Update modification times of quota files when userspace can
7173 	 * start looking at them. If we fail, we return success anyway since
7174 	 * this is not a hard failure and quotas are already disabled.
7175 	 */
7176 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
7177 	if (IS_ERR(handle)) {
7178 		err = PTR_ERR(handle);
7179 		goto out_unlock;
7180 	}
7181 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7182 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7183 	inode->i_mtime = inode_set_ctime_current(inode);
7184 	err = ext4_mark_inode_dirty(handle, inode);
7185 	ext4_journal_stop(handle);
7186 out_unlock:
7187 	inode_unlock(inode);
7188 out_put:
7189 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7190 	iput(inode);
7191 	return err;
7192 out:
7193 	return dquot_quota_off(sb, type);
7194 }
7195 
7196 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7197  * acquiring the locks... As quota files are never truncated and quota code
7198  * itself serializes the operations (and no one else should touch the files)
7199  * we don't have to be afraid of races */
7200 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7201 			       size_t len, loff_t off)
7202 {
7203 	struct inode *inode = sb_dqopt(sb)->files[type];
7204 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7205 	int offset = off & (sb->s_blocksize - 1);
7206 	int tocopy;
7207 	size_t toread;
7208 	struct buffer_head *bh;
7209 	loff_t i_size = i_size_read(inode);
7210 
7211 	if (off > i_size)
7212 		return 0;
7213 	if (off+len > i_size)
7214 		len = i_size-off;
7215 	toread = len;
7216 	while (toread > 0) {
7217 		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
7218 		bh = ext4_bread(NULL, inode, blk, 0);
7219 		if (IS_ERR(bh))
7220 			return PTR_ERR(bh);
7221 		if (!bh)	/* A hole? */
7222 			memset(data, 0, tocopy);
7223 		else
7224 			memcpy(data, bh->b_data+offset, tocopy);
7225 		brelse(bh);
7226 		offset = 0;
7227 		toread -= tocopy;
7228 		data += tocopy;
7229 		blk++;
7230 	}
7231 	return len;
7232 }
7233 
7234 /* Write to quotafile (we know the transaction is already started and has
7235  * enough credits) */
7236 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7237 				const char *data, size_t len, loff_t off)
7238 {
7239 	struct inode *inode = sb_dqopt(sb)->files[type];
7240 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7241 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7242 	int retries = 0;
7243 	struct buffer_head *bh;
7244 	handle_t *handle = journal_current_handle();
7245 
7246 	if (!handle) {
7247 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7248 			" cancelled because transaction is not started",
7249 			(unsigned long long)off, (unsigned long long)len);
7250 		return -EIO;
7251 	}
7252 	/*
7253 	 * Since we account only one data block in transaction credits,
7254 	 * then it is impossible to cross a block boundary.
7255 	 */
7256 	if (sb->s_blocksize - offset < len) {
7257 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7258 			" cancelled because not block aligned",
7259 			(unsigned long long)off, (unsigned long long)len);
7260 		return -EIO;
7261 	}
7262 
7263 	do {
7264 		bh = ext4_bread(handle, inode, blk,
7265 				EXT4_GET_BLOCKS_CREATE |
7266 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
7267 	} while (PTR_ERR(bh) == -ENOSPC &&
7268 		 ext4_should_retry_alloc(inode->i_sb, &retries));
7269 	if (IS_ERR(bh))
7270 		return PTR_ERR(bh);
7271 	if (!bh)
7272 		goto out;
7273 	BUFFER_TRACE(bh, "get write access");
7274 	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7275 	if (err) {
7276 		brelse(bh);
7277 		return err;
7278 	}
7279 	lock_buffer(bh);
7280 	memcpy(bh->b_data+offset, data, len);
7281 	flush_dcache_page(bh->b_page);
7282 	unlock_buffer(bh);
7283 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
7284 	brelse(bh);
7285 out:
7286 	if (inode->i_size < off + len) {
7287 		i_size_write(inode, off + len);
7288 		EXT4_I(inode)->i_disksize = inode->i_size;
7289 		err2 = ext4_mark_inode_dirty(handle, inode);
7290 		if (unlikely(err2 && !err))
7291 			err = err2;
7292 	}
7293 	return err ? err : len;
7294 }
7295 #endif
7296 
7297 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7298 static inline void register_as_ext2(void)
7299 {
7300 	int err = register_filesystem(&ext2_fs_type);
7301 	if (err)
7302 		printk(KERN_WARNING
7303 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7304 }
7305 
7306 static inline void unregister_as_ext2(void)
7307 {
7308 	unregister_filesystem(&ext2_fs_type);
7309 }
7310 
7311 static inline int ext2_feature_set_ok(struct super_block *sb)
7312 {
7313 	if (ext4_has_unknown_ext2_incompat_features(sb))
7314 		return 0;
7315 	if (sb_rdonly(sb))
7316 		return 1;
7317 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
7318 		return 0;
7319 	return 1;
7320 }
7321 #else
7322 static inline void register_as_ext2(void) { }
7323 static inline void unregister_as_ext2(void) { }
7324 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7325 #endif
7326 
7327 static inline void register_as_ext3(void)
7328 {
7329 	int err = register_filesystem(&ext3_fs_type);
7330 	if (err)
7331 		printk(KERN_WARNING
7332 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7333 }
7334 
7335 static inline void unregister_as_ext3(void)
7336 {
7337 	unregister_filesystem(&ext3_fs_type);
7338 }
7339 
7340 static inline int ext3_feature_set_ok(struct super_block *sb)
7341 {
7342 	if (ext4_has_unknown_ext3_incompat_features(sb))
7343 		return 0;
7344 	if (!ext4_has_feature_journal(sb))
7345 		return 0;
7346 	if (sb_rdonly(sb))
7347 		return 1;
7348 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
7349 		return 0;
7350 	return 1;
7351 }
7352 
7353 static void ext4_kill_sb(struct super_block *sb)
7354 {
7355 	struct ext4_sb_info *sbi = EXT4_SB(sb);
7356 	struct block_device *journal_bdev = sbi ? sbi->s_journal_bdev : NULL;
7357 
7358 	kill_block_super(sb);
7359 
7360 	if (journal_bdev)
7361 		blkdev_put(journal_bdev, sb);
7362 }
7363 
7364 static struct file_system_type ext4_fs_type = {
7365 	.owner			= THIS_MODULE,
7366 	.name			= "ext4",
7367 	.init_fs_context	= ext4_init_fs_context,
7368 	.parameters		= ext4_param_specs,
7369 	.kill_sb		= ext4_kill_sb,
7370 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7371 };
7372 MODULE_ALIAS_FS("ext4");
7373 
7374 /* Shared across all ext4 file systems */
7375 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7376 
7377 static int __init ext4_init_fs(void)
7378 {
7379 	int i, err;
7380 
7381 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7382 	ext4_li_info = NULL;
7383 
7384 	/* Build-time check for flags consistency */
7385 	ext4_check_flag_values();
7386 
7387 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7388 		init_waitqueue_head(&ext4__ioend_wq[i]);
7389 
7390 	err = ext4_init_es();
7391 	if (err)
7392 		return err;
7393 
7394 	err = ext4_init_pending();
7395 	if (err)
7396 		goto out7;
7397 
7398 	err = ext4_init_post_read_processing();
7399 	if (err)
7400 		goto out6;
7401 
7402 	err = ext4_init_pageio();
7403 	if (err)
7404 		goto out5;
7405 
7406 	err = ext4_init_system_zone();
7407 	if (err)
7408 		goto out4;
7409 
7410 	err = ext4_init_sysfs();
7411 	if (err)
7412 		goto out3;
7413 
7414 	err = ext4_init_mballoc();
7415 	if (err)
7416 		goto out2;
7417 	err = init_inodecache();
7418 	if (err)
7419 		goto out1;
7420 
7421 	err = ext4_fc_init_dentry_cache();
7422 	if (err)
7423 		goto out05;
7424 
7425 	register_as_ext3();
7426 	register_as_ext2();
7427 	err = register_filesystem(&ext4_fs_type);
7428 	if (err)
7429 		goto out;
7430 
7431 	return 0;
7432 out:
7433 	unregister_as_ext2();
7434 	unregister_as_ext3();
7435 	ext4_fc_destroy_dentry_cache();
7436 out05:
7437 	destroy_inodecache();
7438 out1:
7439 	ext4_exit_mballoc();
7440 out2:
7441 	ext4_exit_sysfs();
7442 out3:
7443 	ext4_exit_system_zone();
7444 out4:
7445 	ext4_exit_pageio();
7446 out5:
7447 	ext4_exit_post_read_processing();
7448 out6:
7449 	ext4_exit_pending();
7450 out7:
7451 	ext4_exit_es();
7452 
7453 	return err;
7454 }
7455 
7456 static void __exit ext4_exit_fs(void)
7457 {
7458 	ext4_destroy_lazyinit_thread();
7459 	unregister_as_ext2();
7460 	unregister_as_ext3();
7461 	unregister_filesystem(&ext4_fs_type);
7462 	ext4_fc_destroy_dentry_cache();
7463 	destroy_inodecache();
7464 	ext4_exit_mballoc();
7465 	ext4_exit_sysfs();
7466 	ext4_exit_system_zone();
7467 	ext4_exit_pageio();
7468 	ext4_exit_post_read_processing();
7469 	ext4_exit_es();
7470 	ext4_exit_pending();
7471 }
7472 
7473 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7474 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7475 MODULE_LICENSE("GPL");
7476 MODULE_SOFTDEP("pre: crc32c");
7477 module_init(ext4_init_fs)
7478 module_exit(ext4_exit_fs)
7479