xref: /linux/fs/ext4/super.c (revision ed30aef3c864f99111e16d4ea5cf29488d99a278)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/cleancache.h>
43 #include <linux/uaccess.h>
44 #include <linux/iversion.h>
45 #include <linux/unicode.h>
46 #include <linux/part_stat.h>
47 #include <linux/kthread.h>
48 #include <linux/freezer.h>
49 
50 #include "ext4.h"
51 #include "ext4_extents.h"	/* Needed for trace points definition */
52 #include "ext4_jbd2.h"
53 #include "xattr.h"
54 #include "acl.h"
55 #include "mballoc.h"
56 #include "fsmap.h"
57 
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/ext4.h>
60 
61 static struct ext4_lazy_init *ext4_li_info;
62 static struct mutex ext4_li_mtx;
63 static struct ratelimit_state ext4_mount_msg_ratelimit;
64 
65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
66 			     unsigned long journal_devnum);
67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
68 static int ext4_commit_super(struct super_block *sb, int sync);
69 static int ext4_mark_recovery_complete(struct super_block *sb,
70 					struct ext4_super_block *es);
71 static int ext4_clear_journal_err(struct super_block *sb,
72 				  struct ext4_super_block *es);
73 static int ext4_sync_fs(struct super_block *sb, int wait);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79 		       const char *dev_name, void *data);
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 int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 static struct inode *ext4_get_journal_inode(struct super_block *sb,
87 					    unsigned int journal_inum);
88 
89 /*
90  * Lock ordering
91  *
92  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
93  * i_mmap_rwsem (inode->i_mmap_rwsem)!
94  *
95  * page fault path:
96  * mmap_lock -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
97  *   page lock -> i_data_sem (rw)
98  *
99  * buffered write path:
100  * sb_start_write -> i_mutex -> mmap_lock
101  * sb_start_write -> i_mutex -> transaction start -> page lock ->
102  *   i_data_sem (rw)
103  *
104  * truncate:
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
106  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
107  *   i_data_sem (rw)
108  *
109  * direct IO:
110  * sb_start_write -> i_mutex -> mmap_lock
111  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
112  *
113  * writepages:
114  * transaction start -> page lock(s) -> i_data_sem (rw)
115  */
116 
117 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
118 static struct file_system_type ext2_fs_type = {
119 	.owner		= THIS_MODULE,
120 	.name		= "ext2",
121 	.mount		= ext4_mount,
122 	.kill_sb	= kill_block_super,
123 	.fs_flags	= FS_REQUIRES_DEV,
124 };
125 MODULE_ALIAS_FS("ext2");
126 MODULE_ALIAS("ext2");
127 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
128 #else
129 #define IS_EXT2_SB(sb) (0)
130 #endif
131 
132 
133 static struct file_system_type ext3_fs_type = {
134 	.owner		= THIS_MODULE,
135 	.name		= "ext3",
136 	.mount		= ext4_mount,
137 	.kill_sb	= kill_block_super,
138 	.fs_flags	= FS_REQUIRES_DEV,
139 };
140 MODULE_ALIAS_FS("ext3");
141 MODULE_ALIAS("ext3");
142 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
143 
144 
145 static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags,
146 				  bh_end_io_t *end_io)
147 {
148 	/*
149 	 * buffer's verified bit is no longer valid after reading from
150 	 * disk again due to write out error, clear it to make sure we
151 	 * recheck the buffer contents.
152 	 */
153 	clear_buffer_verified(bh);
154 
155 	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
156 	get_bh(bh);
157 	submit_bh(REQ_OP_READ, op_flags, bh);
158 }
159 
160 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
161 			 bh_end_io_t *end_io)
162 {
163 	BUG_ON(!buffer_locked(bh));
164 
165 	if (ext4_buffer_uptodate(bh)) {
166 		unlock_buffer(bh);
167 		return;
168 	}
169 	__ext4_read_bh(bh, op_flags, end_io);
170 }
171 
172 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
173 {
174 	BUG_ON(!buffer_locked(bh));
175 
176 	if (ext4_buffer_uptodate(bh)) {
177 		unlock_buffer(bh);
178 		return 0;
179 	}
180 
181 	__ext4_read_bh(bh, op_flags, end_io);
182 
183 	wait_on_buffer(bh);
184 	if (buffer_uptodate(bh))
185 		return 0;
186 	return -EIO;
187 }
188 
189 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
190 {
191 	if (trylock_buffer(bh)) {
192 		if (wait)
193 			return ext4_read_bh(bh, op_flags, NULL);
194 		ext4_read_bh_nowait(bh, op_flags, NULL);
195 		return 0;
196 	}
197 	if (wait) {
198 		wait_on_buffer(bh);
199 		if (buffer_uptodate(bh))
200 			return 0;
201 		return -EIO;
202 	}
203 	return 0;
204 }
205 
206 /*
207  * This works like __bread_gfp() except it uses ERR_PTR for error
208  * returns.  Currently with sb_bread it's impossible to distinguish
209  * between ENOMEM and EIO situations (since both result in a NULL
210  * return.
211  */
212 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
213 					       sector_t block, int op_flags,
214 					       gfp_t gfp)
215 {
216 	struct buffer_head *bh;
217 	int ret;
218 
219 	bh = sb_getblk_gfp(sb, block, gfp);
220 	if (bh == NULL)
221 		return ERR_PTR(-ENOMEM);
222 	if (ext4_buffer_uptodate(bh))
223 		return bh;
224 
225 	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
226 	if (ret) {
227 		put_bh(bh);
228 		return ERR_PTR(ret);
229 	}
230 	return bh;
231 }
232 
233 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
234 				   int op_flags)
235 {
236 	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
237 }
238 
239 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
240 					    sector_t block)
241 {
242 	return __ext4_sb_bread_gfp(sb, block, 0, 0);
243 }
244 
245 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
246 {
247 	struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
248 
249 	if (likely(bh)) {
250 		ext4_read_bh_lock(bh, REQ_RAHEAD, false);
251 		brelse(bh);
252 	}
253 }
254 
255 static int ext4_verify_csum_type(struct super_block *sb,
256 				 struct ext4_super_block *es)
257 {
258 	if (!ext4_has_feature_metadata_csum(sb))
259 		return 1;
260 
261 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
262 }
263 
264 static __le32 ext4_superblock_csum(struct super_block *sb,
265 				   struct ext4_super_block *es)
266 {
267 	struct ext4_sb_info *sbi = EXT4_SB(sb);
268 	int offset = offsetof(struct ext4_super_block, s_checksum);
269 	__u32 csum;
270 
271 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
272 
273 	return cpu_to_le32(csum);
274 }
275 
276 static int ext4_superblock_csum_verify(struct super_block *sb,
277 				       struct ext4_super_block *es)
278 {
279 	if (!ext4_has_metadata_csum(sb))
280 		return 1;
281 
282 	return es->s_checksum == ext4_superblock_csum(sb, es);
283 }
284 
285 void ext4_superblock_csum_set(struct super_block *sb)
286 {
287 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
288 
289 	if (!ext4_has_metadata_csum(sb))
290 		return;
291 
292 	/*
293 	 * Locking the superblock prevents the scenario
294 	 * where:
295 	 *  1) a first thread pauses during checksum calculation.
296 	 *  2) a second thread updates the superblock, recalculates
297 	 *     the checksum, and updates s_checksum
298 	 *  3) the first thread resumes and finishes its checksum calculation
299 	 *     and updates s_checksum with a potentially stale or torn value.
300 	 */
301 	lock_buffer(EXT4_SB(sb)->s_sbh);
302 	es->s_checksum = ext4_superblock_csum(sb, es);
303 	unlock_buffer(EXT4_SB(sb)->s_sbh);
304 }
305 
306 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
307 			       struct ext4_group_desc *bg)
308 {
309 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
310 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
311 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
312 }
313 
314 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
315 			       struct ext4_group_desc *bg)
316 {
317 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
318 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
319 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
320 }
321 
322 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
323 			      struct ext4_group_desc *bg)
324 {
325 	return le32_to_cpu(bg->bg_inode_table_lo) |
326 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
327 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
328 }
329 
330 __u32 ext4_free_group_clusters(struct super_block *sb,
331 			       struct ext4_group_desc *bg)
332 {
333 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
334 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
335 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
336 }
337 
338 __u32 ext4_free_inodes_count(struct super_block *sb,
339 			      struct ext4_group_desc *bg)
340 {
341 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
342 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
343 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
344 }
345 
346 __u32 ext4_used_dirs_count(struct super_block *sb,
347 			      struct ext4_group_desc *bg)
348 {
349 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
350 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
351 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
352 }
353 
354 __u32 ext4_itable_unused_count(struct super_block *sb,
355 			      struct ext4_group_desc *bg)
356 {
357 	return le16_to_cpu(bg->bg_itable_unused_lo) |
358 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
359 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
360 }
361 
362 void ext4_block_bitmap_set(struct super_block *sb,
363 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
364 {
365 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
366 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
367 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
368 }
369 
370 void ext4_inode_bitmap_set(struct super_block *sb,
371 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
372 {
373 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
374 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
375 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
376 }
377 
378 void ext4_inode_table_set(struct super_block *sb,
379 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
380 {
381 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
382 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
383 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
384 }
385 
386 void ext4_free_group_clusters_set(struct super_block *sb,
387 				  struct ext4_group_desc *bg, __u32 count)
388 {
389 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
390 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
391 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
392 }
393 
394 void ext4_free_inodes_set(struct super_block *sb,
395 			  struct ext4_group_desc *bg, __u32 count)
396 {
397 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
398 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
399 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
400 }
401 
402 void ext4_used_dirs_set(struct super_block *sb,
403 			  struct ext4_group_desc *bg, __u32 count)
404 {
405 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
406 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
407 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
408 }
409 
410 void ext4_itable_unused_set(struct super_block *sb,
411 			  struct ext4_group_desc *bg, __u32 count)
412 {
413 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
414 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
415 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
416 }
417 
418 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
419 {
420 	time64_t now = ktime_get_real_seconds();
421 
422 	now = clamp_val(now, 0, (1ull << 40) - 1);
423 
424 	*lo = cpu_to_le32(lower_32_bits(now));
425 	*hi = upper_32_bits(now);
426 }
427 
428 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
429 {
430 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
431 }
432 #define ext4_update_tstamp(es, tstamp) \
433 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
434 #define ext4_get_tstamp(es, tstamp) \
435 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
436 
437 static void __save_error_info(struct super_block *sb, int error,
438 			      __u32 ino, __u64 block,
439 			      const char *func, unsigned int line)
440 {
441 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
442 	int err;
443 
444 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
445 	if (bdev_read_only(sb->s_bdev))
446 		return;
447 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
448 	ext4_update_tstamp(es, s_last_error_time);
449 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
450 	es->s_last_error_line = cpu_to_le32(line);
451 	es->s_last_error_ino = cpu_to_le32(ino);
452 	es->s_last_error_block = cpu_to_le64(block);
453 	switch (error) {
454 	case EIO:
455 		err = EXT4_ERR_EIO;
456 		break;
457 	case ENOMEM:
458 		err = EXT4_ERR_ENOMEM;
459 		break;
460 	case EFSBADCRC:
461 		err = EXT4_ERR_EFSBADCRC;
462 		break;
463 	case 0:
464 	case EFSCORRUPTED:
465 		err = EXT4_ERR_EFSCORRUPTED;
466 		break;
467 	case ENOSPC:
468 		err = EXT4_ERR_ENOSPC;
469 		break;
470 	case ENOKEY:
471 		err = EXT4_ERR_ENOKEY;
472 		break;
473 	case EROFS:
474 		err = EXT4_ERR_EROFS;
475 		break;
476 	case EFBIG:
477 		err = EXT4_ERR_EFBIG;
478 		break;
479 	case EEXIST:
480 		err = EXT4_ERR_EEXIST;
481 		break;
482 	case ERANGE:
483 		err = EXT4_ERR_ERANGE;
484 		break;
485 	case EOVERFLOW:
486 		err = EXT4_ERR_EOVERFLOW;
487 		break;
488 	case EBUSY:
489 		err = EXT4_ERR_EBUSY;
490 		break;
491 	case ENOTDIR:
492 		err = EXT4_ERR_ENOTDIR;
493 		break;
494 	case ENOTEMPTY:
495 		err = EXT4_ERR_ENOTEMPTY;
496 		break;
497 	case ESHUTDOWN:
498 		err = EXT4_ERR_ESHUTDOWN;
499 		break;
500 	case EFAULT:
501 		err = EXT4_ERR_EFAULT;
502 		break;
503 	default:
504 		err = EXT4_ERR_UNKNOWN;
505 	}
506 	es->s_last_error_errcode = err;
507 	if (!es->s_first_error_time) {
508 		es->s_first_error_time = es->s_last_error_time;
509 		es->s_first_error_time_hi = es->s_last_error_time_hi;
510 		strncpy(es->s_first_error_func, func,
511 			sizeof(es->s_first_error_func));
512 		es->s_first_error_line = cpu_to_le32(line);
513 		es->s_first_error_ino = es->s_last_error_ino;
514 		es->s_first_error_block = es->s_last_error_block;
515 		es->s_first_error_errcode = es->s_last_error_errcode;
516 	}
517 	/*
518 	 * Start the daily error reporting function if it hasn't been
519 	 * started already
520 	 */
521 	if (!es->s_error_count)
522 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
523 	le32_add_cpu(&es->s_error_count, 1);
524 }
525 
526 static void save_error_info(struct super_block *sb, int error,
527 			    __u32 ino, __u64 block,
528 			    const char *func, unsigned int line)
529 {
530 	__save_error_info(sb, error, ino, block, func, line);
531 	if (!bdev_read_only(sb->s_bdev))
532 		ext4_commit_super(sb, 1);
533 }
534 
535 /*
536  * The del_gendisk() function uninitializes the disk-specific data
537  * structures, including the bdi structure, without telling anyone
538  * else.  Once this happens, any attempt to call mark_buffer_dirty()
539  * (for example, by ext4_commit_super), will cause a kernel OOPS.
540  * This is a kludge to prevent these oops until we can put in a proper
541  * hook in del_gendisk() to inform the VFS and file system layers.
542  */
543 static int block_device_ejected(struct super_block *sb)
544 {
545 	struct inode *bd_inode = sb->s_bdev->bd_inode;
546 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
547 
548 	return bdi->dev == NULL;
549 }
550 
551 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
552 {
553 	struct super_block		*sb = journal->j_private;
554 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
555 	int				error = is_journal_aborted(journal);
556 	struct ext4_journal_cb_entry	*jce;
557 
558 	BUG_ON(txn->t_state == T_FINISHED);
559 
560 	ext4_process_freed_data(sb, txn->t_tid);
561 
562 	spin_lock(&sbi->s_md_lock);
563 	while (!list_empty(&txn->t_private_list)) {
564 		jce = list_entry(txn->t_private_list.next,
565 				 struct ext4_journal_cb_entry, jce_list);
566 		list_del_init(&jce->jce_list);
567 		spin_unlock(&sbi->s_md_lock);
568 		jce->jce_func(sb, jce, error);
569 		spin_lock(&sbi->s_md_lock);
570 	}
571 	spin_unlock(&sbi->s_md_lock);
572 }
573 
574 /*
575  * This writepage callback for write_cache_pages()
576  * takes care of a few cases after page cleaning.
577  *
578  * write_cache_pages() already checks for dirty pages
579  * and calls clear_page_dirty_for_io(), which we want,
580  * to write protect the pages.
581  *
582  * However, we may have to redirty a page (see below.)
583  */
584 static int ext4_journalled_writepage_callback(struct page *page,
585 					      struct writeback_control *wbc,
586 					      void *data)
587 {
588 	transaction_t *transaction = (transaction_t *) data;
589 	struct buffer_head *bh, *head;
590 	struct journal_head *jh;
591 
592 	bh = head = page_buffers(page);
593 	do {
594 		/*
595 		 * We have to redirty a page in these cases:
596 		 * 1) If buffer is dirty, it means the page was dirty because it
597 		 * contains a buffer that needs checkpointing. So the dirty bit
598 		 * needs to be preserved so that checkpointing writes the buffer
599 		 * properly.
600 		 * 2) If buffer is not part of the committing transaction
601 		 * (we may have just accidentally come across this buffer because
602 		 * inode range tracking is not exact) or if the currently running
603 		 * transaction already contains this buffer as well, dirty bit
604 		 * needs to be preserved so that the buffer gets writeprotected
605 		 * properly on running transaction's commit.
606 		 */
607 		jh = bh2jh(bh);
608 		if (buffer_dirty(bh) ||
609 		    (jh && (jh->b_transaction != transaction ||
610 			    jh->b_next_transaction))) {
611 			redirty_page_for_writepage(wbc, page);
612 			goto out;
613 		}
614 	} while ((bh = bh->b_this_page) != head);
615 
616 out:
617 	return AOP_WRITEPAGE_ACTIVATE;
618 }
619 
620 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
621 {
622 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
623 	struct writeback_control wbc = {
624 		.sync_mode =  WB_SYNC_ALL,
625 		.nr_to_write = LONG_MAX,
626 		.range_start = jinode->i_dirty_start,
627 		.range_end = jinode->i_dirty_end,
628         };
629 
630 	return write_cache_pages(mapping, &wbc,
631 				 ext4_journalled_writepage_callback,
632 				 jinode->i_transaction);
633 }
634 
635 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
636 {
637 	int ret;
638 
639 	if (ext4_should_journal_data(jinode->i_vfs_inode))
640 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
641 	else
642 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
643 
644 	return ret;
645 }
646 
647 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
648 {
649 	int ret = 0;
650 
651 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
652 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
653 
654 	return ret;
655 }
656 
657 static bool system_going_down(void)
658 {
659 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
660 		|| system_state == SYSTEM_RESTART;
661 }
662 
663 /* Deal with the reporting of failure conditions on a filesystem such as
664  * inconsistencies detected or read IO failures.
665  *
666  * On ext2, we can store the error state of the filesystem in the
667  * superblock.  That is not possible on ext4, because we may have other
668  * write ordering constraints on the superblock which prevent us from
669  * writing it out straight away; and given that the journal is about to
670  * be aborted, we can't rely on the current, or future, transactions to
671  * write out the superblock safely.
672  *
673  * We'll just use the jbd2_journal_abort() error code to record an error in
674  * the journal instead.  On recovery, the journal will complain about
675  * that error until we've noted it down and cleared it.
676  */
677 
678 static void ext4_handle_error(struct super_block *sb)
679 {
680 	if (test_opt(sb, WARN_ON_ERROR))
681 		WARN_ON_ONCE(1);
682 
683 	if (sb_rdonly(sb))
684 		return;
685 
686 	if (!test_opt(sb, ERRORS_CONT)) {
687 		journal_t *journal = EXT4_SB(sb)->s_journal;
688 
689 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
690 		if (journal)
691 			jbd2_journal_abort(journal, -EIO);
692 	}
693 	/*
694 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
695 	 * could panic during 'reboot -f' as the underlying device got already
696 	 * disabled.
697 	 */
698 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
699 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
700 		/*
701 		 * Make sure updated value of ->s_mount_flags will be visible
702 		 * before ->s_flags update
703 		 */
704 		smp_wmb();
705 		sb->s_flags |= SB_RDONLY;
706 	} else if (test_opt(sb, ERRORS_PANIC)) {
707 		panic("EXT4-fs (device %s): panic forced after error\n",
708 			sb->s_id);
709 	}
710 }
711 
712 #define ext4_error_ratelimit(sb)					\
713 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
714 			     "EXT4-fs error")
715 
716 void __ext4_error(struct super_block *sb, const char *function,
717 		  unsigned int line, int error, __u64 block,
718 		  const char *fmt, ...)
719 {
720 	struct va_format vaf;
721 	va_list args;
722 
723 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
724 		return;
725 
726 	trace_ext4_error(sb, function, line);
727 	if (ext4_error_ratelimit(sb)) {
728 		va_start(args, fmt);
729 		vaf.fmt = fmt;
730 		vaf.va = &args;
731 		printk(KERN_CRIT
732 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
733 		       sb->s_id, function, line, current->comm, &vaf);
734 		va_end(args);
735 	}
736 	save_error_info(sb, error, 0, block, function, line);
737 	ext4_handle_error(sb);
738 }
739 
740 void __ext4_error_inode(struct inode *inode, const char *function,
741 			unsigned int line, ext4_fsblk_t block, int error,
742 			const char *fmt, ...)
743 {
744 	va_list args;
745 	struct va_format vaf;
746 
747 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
748 		return;
749 
750 	trace_ext4_error(inode->i_sb, function, line);
751 	if (ext4_error_ratelimit(inode->i_sb)) {
752 		va_start(args, fmt);
753 		vaf.fmt = fmt;
754 		vaf.va = &args;
755 		if (block)
756 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
757 			       "inode #%lu: block %llu: comm %s: %pV\n",
758 			       inode->i_sb->s_id, function, line, inode->i_ino,
759 			       block, current->comm, &vaf);
760 		else
761 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
762 			       "inode #%lu: comm %s: %pV\n",
763 			       inode->i_sb->s_id, function, line, inode->i_ino,
764 			       current->comm, &vaf);
765 		va_end(args);
766 	}
767 	save_error_info(inode->i_sb, error, inode->i_ino, block,
768 			function, line);
769 	ext4_handle_error(inode->i_sb);
770 }
771 
772 void __ext4_error_file(struct file *file, const char *function,
773 		       unsigned int line, ext4_fsblk_t block,
774 		       const char *fmt, ...)
775 {
776 	va_list args;
777 	struct va_format vaf;
778 	struct inode *inode = file_inode(file);
779 	char pathname[80], *path;
780 
781 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
782 		return;
783 
784 	trace_ext4_error(inode->i_sb, function, line);
785 	if (ext4_error_ratelimit(inode->i_sb)) {
786 		path = file_path(file, pathname, sizeof(pathname));
787 		if (IS_ERR(path))
788 			path = "(unknown)";
789 		va_start(args, fmt);
790 		vaf.fmt = fmt;
791 		vaf.va = &args;
792 		if (block)
793 			printk(KERN_CRIT
794 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
795 			       "block %llu: comm %s: path %s: %pV\n",
796 			       inode->i_sb->s_id, function, line, inode->i_ino,
797 			       block, current->comm, path, &vaf);
798 		else
799 			printk(KERN_CRIT
800 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
801 			       "comm %s: path %s: %pV\n",
802 			       inode->i_sb->s_id, function, line, inode->i_ino,
803 			       current->comm, path, &vaf);
804 		va_end(args);
805 	}
806 	save_error_info(inode->i_sb, EFSCORRUPTED, inode->i_ino, block,
807 			function, line);
808 	ext4_handle_error(inode->i_sb);
809 }
810 
811 const char *ext4_decode_error(struct super_block *sb, int errno,
812 			      char nbuf[16])
813 {
814 	char *errstr = NULL;
815 
816 	switch (errno) {
817 	case -EFSCORRUPTED:
818 		errstr = "Corrupt filesystem";
819 		break;
820 	case -EFSBADCRC:
821 		errstr = "Filesystem failed CRC";
822 		break;
823 	case -EIO:
824 		errstr = "IO failure";
825 		break;
826 	case -ENOMEM:
827 		errstr = "Out of memory";
828 		break;
829 	case -EROFS:
830 		if (!sb || (EXT4_SB(sb)->s_journal &&
831 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
832 			errstr = "Journal has aborted";
833 		else
834 			errstr = "Readonly filesystem";
835 		break;
836 	default:
837 		/* If the caller passed in an extra buffer for unknown
838 		 * errors, textualise them now.  Else we just return
839 		 * NULL. */
840 		if (nbuf) {
841 			/* Check for truncated error codes... */
842 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
843 				errstr = nbuf;
844 		}
845 		break;
846 	}
847 
848 	return errstr;
849 }
850 
851 /* __ext4_std_error decodes expected errors from journaling functions
852  * automatically and invokes the appropriate error response.  */
853 
854 void __ext4_std_error(struct super_block *sb, const char *function,
855 		      unsigned int line, int errno)
856 {
857 	char nbuf[16];
858 	const char *errstr;
859 
860 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
861 		return;
862 
863 	/* Special case: if the error is EROFS, and we're not already
864 	 * inside a transaction, then there's really no point in logging
865 	 * an error. */
866 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
867 		return;
868 
869 	if (ext4_error_ratelimit(sb)) {
870 		errstr = ext4_decode_error(sb, errno, nbuf);
871 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
872 		       sb->s_id, function, line, errstr);
873 	}
874 
875 	save_error_info(sb, -errno, 0, 0, function, line);
876 	ext4_handle_error(sb);
877 }
878 
879 /*
880  * ext4_abort is a much stronger failure handler than ext4_error.  The
881  * abort function may be used to deal with unrecoverable failures such
882  * as journal IO errors or ENOMEM at a critical moment in log management.
883  *
884  * We unconditionally force the filesystem into an ABORT|READONLY state,
885  * unless the error response on the fs has been set to panic in which
886  * case we take the easy way out and panic immediately.
887  */
888 
889 void __ext4_abort(struct super_block *sb, const char *function,
890 		  unsigned int line, int error, const char *fmt, ...)
891 {
892 	struct va_format vaf;
893 	va_list args;
894 
895 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
896 		return;
897 
898 	save_error_info(sb, error, 0, 0, function, line);
899 	va_start(args, fmt);
900 	vaf.fmt = fmt;
901 	vaf.va = &args;
902 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
903 	       sb->s_id, function, line, &vaf);
904 	va_end(args);
905 
906 	if (sb_rdonly(sb) == 0) {
907 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
908 		if (EXT4_SB(sb)->s_journal)
909 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
910 
911 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
912 		/*
913 		 * Make sure updated value of ->s_mount_flags will be visible
914 		 * before ->s_flags update
915 		 */
916 		smp_wmb();
917 		sb->s_flags |= SB_RDONLY;
918 	}
919 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down())
920 		panic("EXT4-fs panic from previous error\n");
921 }
922 
923 void __ext4_msg(struct super_block *sb,
924 		const char *prefix, const char *fmt, ...)
925 {
926 	struct va_format vaf;
927 	va_list args;
928 
929 	atomic_inc(&EXT4_SB(sb)->s_msg_count);
930 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
931 		return;
932 
933 	va_start(args, fmt);
934 	vaf.fmt = fmt;
935 	vaf.va = &args;
936 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
937 	va_end(args);
938 }
939 
940 static int ext4_warning_ratelimit(struct super_block *sb)
941 {
942 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
943 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
944 			    "EXT4-fs warning");
945 }
946 
947 void __ext4_warning(struct super_block *sb, const char *function,
948 		    unsigned int line, const char *fmt, ...)
949 {
950 	struct va_format vaf;
951 	va_list args;
952 
953 	if (!ext4_warning_ratelimit(sb))
954 		return;
955 
956 	va_start(args, fmt);
957 	vaf.fmt = fmt;
958 	vaf.va = &args;
959 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
960 	       sb->s_id, function, line, &vaf);
961 	va_end(args);
962 }
963 
964 void __ext4_warning_inode(const struct inode *inode, const char *function,
965 			  unsigned int line, const char *fmt, ...)
966 {
967 	struct va_format vaf;
968 	va_list args;
969 
970 	if (!ext4_warning_ratelimit(inode->i_sb))
971 		return;
972 
973 	va_start(args, fmt);
974 	vaf.fmt = fmt;
975 	vaf.va = &args;
976 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
977 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
978 	       function, line, inode->i_ino, current->comm, &vaf);
979 	va_end(args);
980 }
981 
982 void __ext4_grp_locked_error(const char *function, unsigned int line,
983 			     struct super_block *sb, ext4_group_t grp,
984 			     unsigned long ino, ext4_fsblk_t block,
985 			     const char *fmt, ...)
986 __releases(bitlock)
987 __acquires(bitlock)
988 {
989 	struct va_format vaf;
990 	va_list args;
991 
992 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
993 		return;
994 
995 	trace_ext4_error(sb, function, line);
996 	__save_error_info(sb, EFSCORRUPTED, ino, block, function, line);
997 
998 	if (ext4_error_ratelimit(sb)) {
999 		va_start(args, fmt);
1000 		vaf.fmt = fmt;
1001 		vaf.va = &args;
1002 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1003 		       sb->s_id, function, line, grp);
1004 		if (ino)
1005 			printk(KERN_CONT "inode %lu: ", ino);
1006 		if (block)
1007 			printk(KERN_CONT "block %llu:",
1008 			       (unsigned long long) block);
1009 		printk(KERN_CONT "%pV\n", &vaf);
1010 		va_end(args);
1011 	}
1012 
1013 	if (test_opt(sb, WARN_ON_ERROR))
1014 		WARN_ON_ONCE(1);
1015 
1016 	if (test_opt(sb, ERRORS_CONT)) {
1017 		ext4_commit_super(sb, 0);
1018 		return;
1019 	}
1020 
1021 	ext4_unlock_group(sb, grp);
1022 	ext4_commit_super(sb, 1);
1023 	ext4_handle_error(sb);
1024 	/*
1025 	 * We only get here in the ERRORS_RO case; relocking the group
1026 	 * may be dangerous, but nothing bad will happen since the
1027 	 * filesystem will have already been marked read/only and the
1028 	 * journal has been aborted.  We return 1 as a hint to callers
1029 	 * who might what to use the return value from
1030 	 * ext4_grp_locked_error() to distinguish between the
1031 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1032 	 * aggressively from the ext4 function in question, with a
1033 	 * more appropriate error code.
1034 	 */
1035 	ext4_lock_group(sb, grp);
1036 	return;
1037 }
1038 
1039 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1040 				     ext4_group_t group,
1041 				     unsigned int flags)
1042 {
1043 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1044 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1045 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1046 	int ret;
1047 
1048 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1049 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1050 					    &grp->bb_state);
1051 		if (!ret)
1052 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1053 					   grp->bb_free);
1054 	}
1055 
1056 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1057 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1058 					    &grp->bb_state);
1059 		if (!ret && gdp) {
1060 			int count;
1061 
1062 			count = ext4_free_inodes_count(sb, gdp);
1063 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1064 					   count);
1065 		}
1066 	}
1067 }
1068 
1069 void ext4_update_dynamic_rev(struct super_block *sb)
1070 {
1071 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1072 
1073 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1074 		return;
1075 
1076 	ext4_warning(sb,
1077 		     "updating to rev %d because of new feature flag, "
1078 		     "running e2fsck is recommended",
1079 		     EXT4_DYNAMIC_REV);
1080 
1081 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1082 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1083 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1084 	/* leave es->s_feature_*compat flags alone */
1085 	/* es->s_uuid will be set by e2fsck if empty */
1086 
1087 	/*
1088 	 * The rest of the superblock fields should be zero, and if not it
1089 	 * means they are likely already in use, so leave them alone.  We
1090 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1091 	 */
1092 }
1093 
1094 /*
1095  * Open the external journal device
1096  */
1097 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1098 {
1099 	struct block_device *bdev;
1100 
1101 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1102 	if (IS_ERR(bdev))
1103 		goto fail;
1104 	return bdev;
1105 
1106 fail:
1107 	ext4_msg(sb, KERN_ERR,
1108 		 "failed to open journal device unknown-block(%u,%u) %ld",
1109 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1110 	return NULL;
1111 }
1112 
1113 /*
1114  * Release the journal device
1115  */
1116 static void ext4_blkdev_put(struct block_device *bdev)
1117 {
1118 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1119 }
1120 
1121 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1122 {
1123 	struct block_device *bdev;
1124 	bdev = sbi->s_journal_bdev;
1125 	if (bdev) {
1126 		ext4_blkdev_put(bdev);
1127 		sbi->s_journal_bdev = NULL;
1128 	}
1129 }
1130 
1131 static inline struct inode *orphan_list_entry(struct list_head *l)
1132 {
1133 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1134 }
1135 
1136 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1137 {
1138 	struct list_head *l;
1139 
1140 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1141 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1142 
1143 	printk(KERN_ERR "sb_info orphan list:\n");
1144 	list_for_each(l, &sbi->s_orphan) {
1145 		struct inode *inode = orphan_list_entry(l);
1146 		printk(KERN_ERR "  "
1147 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1148 		       inode->i_sb->s_id, inode->i_ino, inode,
1149 		       inode->i_mode, inode->i_nlink,
1150 		       NEXT_ORPHAN(inode));
1151 	}
1152 }
1153 
1154 #ifdef CONFIG_QUOTA
1155 static int ext4_quota_off(struct super_block *sb, int type);
1156 
1157 static inline void ext4_quota_off_umount(struct super_block *sb)
1158 {
1159 	int type;
1160 
1161 	/* Use our quota_off function to clear inode flags etc. */
1162 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1163 		ext4_quota_off(sb, type);
1164 }
1165 
1166 /*
1167  * This is a helper function which is used in the mount/remount
1168  * codepaths (which holds s_umount) to fetch the quota file name.
1169  */
1170 static inline char *get_qf_name(struct super_block *sb,
1171 				struct ext4_sb_info *sbi,
1172 				int type)
1173 {
1174 	return rcu_dereference_protected(sbi->s_qf_names[type],
1175 					 lockdep_is_held(&sb->s_umount));
1176 }
1177 #else
1178 static inline void ext4_quota_off_umount(struct super_block *sb)
1179 {
1180 }
1181 #endif
1182 
1183 static void ext4_put_super(struct super_block *sb)
1184 {
1185 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1186 	struct ext4_super_block *es = sbi->s_es;
1187 	struct buffer_head **group_desc;
1188 	struct flex_groups **flex_groups;
1189 	int aborted = 0;
1190 	int i, err;
1191 
1192 	ext4_unregister_li_request(sb);
1193 	ext4_quota_off_umount(sb);
1194 
1195 	destroy_workqueue(sbi->rsv_conversion_wq);
1196 
1197 	/*
1198 	 * Unregister sysfs before destroying jbd2 journal.
1199 	 * Since we could still access attr_journal_task attribute via sysfs
1200 	 * path which could have sbi->s_journal->j_task as NULL
1201 	 */
1202 	ext4_unregister_sysfs(sb);
1203 
1204 	if (sbi->s_journal) {
1205 		aborted = is_journal_aborted(sbi->s_journal);
1206 		err = jbd2_journal_destroy(sbi->s_journal);
1207 		sbi->s_journal = NULL;
1208 		if ((err < 0) && !aborted) {
1209 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1210 		}
1211 	}
1212 
1213 	ext4_es_unregister_shrinker(sbi);
1214 	del_timer_sync(&sbi->s_err_report);
1215 	ext4_release_system_zone(sb);
1216 	ext4_mb_release(sb);
1217 	ext4_ext_release(sb);
1218 
1219 	if (!sb_rdonly(sb) && !aborted) {
1220 		ext4_clear_feature_journal_needs_recovery(sb);
1221 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1222 	}
1223 	if (!sb_rdonly(sb))
1224 		ext4_commit_super(sb, 1);
1225 
1226 	rcu_read_lock();
1227 	group_desc = rcu_dereference(sbi->s_group_desc);
1228 	for (i = 0; i < sbi->s_gdb_count; i++)
1229 		brelse(group_desc[i]);
1230 	kvfree(group_desc);
1231 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1232 	if (flex_groups) {
1233 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1234 			kvfree(flex_groups[i]);
1235 		kvfree(flex_groups);
1236 	}
1237 	rcu_read_unlock();
1238 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1239 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1240 	percpu_counter_destroy(&sbi->s_dirs_counter);
1241 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1242 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1243 #ifdef CONFIG_QUOTA
1244 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1245 		kfree(get_qf_name(sb, sbi, i));
1246 #endif
1247 
1248 	/* Debugging code just in case the in-memory inode orphan list
1249 	 * isn't empty.  The on-disk one can be non-empty if we've
1250 	 * detected an error and taken the fs readonly, but the
1251 	 * in-memory list had better be clean by this point. */
1252 	if (!list_empty(&sbi->s_orphan))
1253 		dump_orphan_list(sb, sbi);
1254 	J_ASSERT(list_empty(&sbi->s_orphan));
1255 
1256 	sync_blockdev(sb->s_bdev);
1257 	invalidate_bdev(sb->s_bdev);
1258 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1259 		/*
1260 		 * Invalidate the journal device's buffers.  We don't want them
1261 		 * floating about in memory - the physical journal device may
1262 		 * hotswapped, and it breaks the `ro-after' testing code.
1263 		 */
1264 		sync_blockdev(sbi->s_journal_bdev);
1265 		invalidate_bdev(sbi->s_journal_bdev);
1266 		ext4_blkdev_remove(sbi);
1267 	}
1268 
1269 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1270 	sbi->s_ea_inode_cache = NULL;
1271 
1272 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1273 	sbi->s_ea_block_cache = NULL;
1274 
1275 	if (sbi->s_mmp_tsk)
1276 		kthread_stop(sbi->s_mmp_tsk);
1277 	brelse(sbi->s_sbh);
1278 	sb->s_fs_info = NULL;
1279 	/*
1280 	 * Now that we are completely done shutting down the
1281 	 * superblock, we need to actually destroy the kobject.
1282 	 */
1283 	kobject_put(&sbi->s_kobj);
1284 	wait_for_completion(&sbi->s_kobj_unregister);
1285 	if (sbi->s_chksum_driver)
1286 		crypto_free_shash(sbi->s_chksum_driver);
1287 	kfree(sbi->s_blockgroup_lock);
1288 	fs_put_dax(sbi->s_daxdev);
1289 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1290 #ifdef CONFIG_UNICODE
1291 	utf8_unload(sb->s_encoding);
1292 #endif
1293 	kfree(sbi);
1294 }
1295 
1296 static struct kmem_cache *ext4_inode_cachep;
1297 
1298 /*
1299  * Called inside transaction, so use GFP_NOFS
1300  */
1301 static struct inode *ext4_alloc_inode(struct super_block *sb)
1302 {
1303 	struct ext4_inode_info *ei;
1304 
1305 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1306 	if (!ei)
1307 		return NULL;
1308 
1309 	inode_set_iversion(&ei->vfs_inode, 1);
1310 	spin_lock_init(&ei->i_raw_lock);
1311 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1312 	atomic_set(&ei->i_prealloc_active, 0);
1313 	spin_lock_init(&ei->i_prealloc_lock);
1314 	ext4_es_init_tree(&ei->i_es_tree);
1315 	rwlock_init(&ei->i_es_lock);
1316 	INIT_LIST_HEAD(&ei->i_es_list);
1317 	ei->i_es_all_nr = 0;
1318 	ei->i_es_shk_nr = 0;
1319 	ei->i_es_shrink_lblk = 0;
1320 	ei->i_reserved_data_blocks = 0;
1321 	spin_lock_init(&(ei->i_block_reservation_lock));
1322 	ext4_init_pending_tree(&ei->i_pending_tree);
1323 #ifdef CONFIG_QUOTA
1324 	ei->i_reserved_quota = 0;
1325 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1326 #endif
1327 	ei->jinode = NULL;
1328 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1329 	spin_lock_init(&ei->i_completed_io_lock);
1330 	ei->i_sync_tid = 0;
1331 	ei->i_datasync_tid = 0;
1332 	atomic_set(&ei->i_unwritten, 0);
1333 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1334 	ext4_fc_init_inode(&ei->vfs_inode);
1335 	mutex_init(&ei->i_fc_lock);
1336 	return &ei->vfs_inode;
1337 }
1338 
1339 static int ext4_drop_inode(struct inode *inode)
1340 {
1341 	int drop = generic_drop_inode(inode);
1342 
1343 	if (!drop)
1344 		drop = fscrypt_drop_inode(inode);
1345 
1346 	trace_ext4_drop_inode(inode, drop);
1347 	return drop;
1348 }
1349 
1350 static void ext4_free_in_core_inode(struct inode *inode)
1351 {
1352 	fscrypt_free_inode(inode);
1353 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1354 		pr_warn("%s: inode %ld still in fc list",
1355 			__func__, inode->i_ino);
1356 	}
1357 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1358 }
1359 
1360 static void ext4_destroy_inode(struct inode *inode)
1361 {
1362 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1363 		ext4_msg(inode->i_sb, KERN_ERR,
1364 			 "Inode %lu (%p): orphan list check failed!",
1365 			 inode->i_ino, EXT4_I(inode));
1366 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1367 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1368 				true);
1369 		dump_stack();
1370 	}
1371 }
1372 
1373 static void init_once(void *foo)
1374 {
1375 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1376 
1377 	INIT_LIST_HEAD(&ei->i_orphan);
1378 	init_rwsem(&ei->xattr_sem);
1379 	init_rwsem(&ei->i_data_sem);
1380 	init_rwsem(&ei->i_mmap_sem);
1381 	inode_init_once(&ei->vfs_inode);
1382 	ext4_fc_init_inode(&ei->vfs_inode);
1383 }
1384 
1385 static int __init init_inodecache(void)
1386 {
1387 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1388 				sizeof(struct ext4_inode_info), 0,
1389 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1390 					SLAB_ACCOUNT),
1391 				offsetof(struct ext4_inode_info, i_data),
1392 				sizeof_field(struct ext4_inode_info, i_data),
1393 				init_once);
1394 	if (ext4_inode_cachep == NULL)
1395 		return -ENOMEM;
1396 	return 0;
1397 }
1398 
1399 static void destroy_inodecache(void)
1400 {
1401 	/*
1402 	 * Make sure all delayed rcu free inodes are flushed before we
1403 	 * destroy cache.
1404 	 */
1405 	rcu_barrier();
1406 	kmem_cache_destroy(ext4_inode_cachep);
1407 }
1408 
1409 void ext4_clear_inode(struct inode *inode)
1410 {
1411 	ext4_fc_del(inode);
1412 	invalidate_inode_buffers(inode);
1413 	clear_inode(inode);
1414 	ext4_discard_preallocations(inode, 0);
1415 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1416 	dquot_drop(inode);
1417 	if (EXT4_I(inode)->jinode) {
1418 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1419 					       EXT4_I(inode)->jinode);
1420 		jbd2_free_inode(EXT4_I(inode)->jinode);
1421 		EXT4_I(inode)->jinode = NULL;
1422 	}
1423 	fscrypt_put_encryption_info(inode);
1424 	fsverity_cleanup_inode(inode);
1425 }
1426 
1427 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1428 					u64 ino, u32 generation)
1429 {
1430 	struct inode *inode;
1431 
1432 	/*
1433 	 * Currently we don't know the generation for parent directory, so
1434 	 * a generation of 0 means "accept any"
1435 	 */
1436 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1437 	if (IS_ERR(inode))
1438 		return ERR_CAST(inode);
1439 	if (generation && inode->i_generation != generation) {
1440 		iput(inode);
1441 		return ERR_PTR(-ESTALE);
1442 	}
1443 
1444 	return inode;
1445 }
1446 
1447 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1448 					int fh_len, int fh_type)
1449 {
1450 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1451 				    ext4_nfs_get_inode);
1452 }
1453 
1454 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1455 					int fh_len, int fh_type)
1456 {
1457 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1458 				    ext4_nfs_get_inode);
1459 }
1460 
1461 static int ext4_nfs_commit_metadata(struct inode *inode)
1462 {
1463 	struct writeback_control wbc = {
1464 		.sync_mode = WB_SYNC_ALL
1465 	};
1466 
1467 	trace_ext4_nfs_commit_metadata(inode);
1468 	return ext4_write_inode(inode, &wbc);
1469 }
1470 
1471 /*
1472  * Try to release metadata pages (indirect blocks, directories) which are
1473  * mapped via the block device.  Since these pages could have journal heads
1474  * which would prevent try_to_free_buffers() from freeing them, we must use
1475  * jbd2 layer's try_to_free_buffers() function to release them.
1476  */
1477 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1478 				 gfp_t wait)
1479 {
1480 	journal_t *journal = EXT4_SB(sb)->s_journal;
1481 
1482 	WARN_ON(PageChecked(page));
1483 	if (!page_has_buffers(page))
1484 		return 0;
1485 	if (journal)
1486 		return jbd2_journal_try_to_free_buffers(journal, page);
1487 
1488 	return try_to_free_buffers(page);
1489 }
1490 
1491 #ifdef CONFIG_FS_ENCRYPTION
1492 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1493 {
1494 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1495 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1496 }
1497 
1498 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1499 							void *fs_data)
1500 {
1501 	handle_t *handle = fs_data;
1502 	int res, res2, credits, retries = 0;
1503 
1504 	/*
1505 	 * Encrypting the root directory is not allowed because e2fsck expects
1506 	 * lost+found to exist and be unencrypted, and encrypting the root
1507 	 * directory would imply encrypting the lost+found directory as well as
1508 	 * the filename "lost+found" itself.
1509 	 */
1510 	if (inode->i_ino == EXT4_ROOT_INO)
1511 		return -EPERM;
1512 
1513 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1514 		return -EINVAL;
1515 
1516 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1517 		return -EOPNOTSUPP;
1518 
1519 	res = ext4_convert_inline_data(inode);
1520 	if (res)
1521 		return res;
1522 
1523 	/*
1524 	 * If a journal handle was specified, then the encryption context is
1525 	 * being set on a new inode via inheritance and is part of a larger
1526 	 * transaction to create the inode.  Otherwise the encryption context is
1527 	 * being set on an existing inode in its own transaction.  Only in the
1528 	 * latter case should the "retry on ENOSPC" logic be used.
1529 	 */
1530 
1531 	if (handle) {
1532 		res = ext4_xattr_set_handle(handle, inode,
1533 					    EXT4_XATTR_INDEX_ENCRYPTION,
1534 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1535 					    ctx, len, 0);
1536 		if (!res) {
1537 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1538 			ext4_clear_inode_state(inode,
1539 					EXT4_STATE_MAY_INLINE_DATA);
1540 			/*
1541 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1542 			 * S_DAX may be disabled
1543 			 */
1544 			ext4_set_inode_flags(inode, false);
1545 		}
1546 		return res;
1547 	}
1548 
1549 	res = dquot_initialize(inode);
1550 	if (res)
1551 		return res;
1552 retry:
1553 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1554 				     &credits);
1555 	if (res)
1556 		return res;
1557 
1558 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1559 	if (IS_ERR(handle))
1560 		return PTR_ERR(handle);
1561 
1562 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1563 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1564 				    ctx, len, 0);
1565 	if (!res) {
1566 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1567 		/*
1568 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1569 		 * S_DAX may be disabled
1570 		 */
1571 		ext4_set_inode_flags(inode, false);
1572 		res = ext4_mark_inode_dirty(handle, inode);
1573 		if (res)
1574 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1575 	}
1576 	res2 = ext4_journal_stop(handle);
1577 
1578 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1579 		goto retry;
1580 	if (!res)
1581 		res = res2;
1582 	return res;
1583 }
1584 
1585 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1586 {
1587 	return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1588 }
1589 
1590 static bool ext4_has_stable_inodes(struct super_block *sb)
1591 {
1592 	return ext4_has_feature_stable_inodes(sb);
1593 }
1594 
1595 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1596 				       int *ino_bits_ret, int *lblk_bits_ret)
1597 {
1598 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1599 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1600 }
1601 
1602 static const struct fscrypt_operations ext4_cryptops = {
1603 	.key_prefix		= "ext4:",
1604 	.get_context		= ext4_get_context,
1605 	.set_context		= ext4_set_context,
1606 	.get_dummy_policy	= ext4_get_dummy_policy,
1607 	.empty_dir		= ext4_empty_dir,
1608 	.max_namelen		= EXT4_NAME_LEN,
1609 	.has_stable_inodes	= ext4_has_stable_inodes,
1610 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1611 };
1612 #endif
1613 
1614 #ifdef CONFIG_QUOTA
1615 static const char * const quotatypes[] = INITQFNAMES;
1616 #define QTYPE2NAME(t) (quotatypes[t])
1617 
1618 static int ext4_write_dquot(struct dquot *dquot);
1619 static int ext4_acquire_dquot(struct dquot *dquot);
1620 static int ext4_release_dquot(struct dquot *dquot);
1621 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1622 static int ext4_write_info(struct super_block *sb, int type);
1623 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1624 			 const struct path *path);
1625 static int ext4_quota_on_mount(struct super_block *sb, int type);
1626 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1627 			       size_t len, loff_t off);
1628 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1629 				const char *data, size_t len, loff_t off);
1630 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1631 			     unsigned int flags);
1632 static int ext4_enable_quotas(struct super_block *sb);
1633 
1634 static struct dquot **ext4_get_dquots(struct inode *inode)
1635 {
1636 	return EXT4_I(inode)->i_dquot;
1637 }
1638 
1639 static const struct dquot_operations ext4_quota_operations = {
1640 	.get_reserved_space	= ext4_get_reserved_space,
1641 	.write_dquot		= ext4_write_dquot,
1642 	.acquire_dquot		= ext4_acquire_dquot,
1643 	.release_dquot		= ext4_release_dquot,
1644 	.mark_dirty		= ext4_mark_dquot_dirty,
1645 	.write_info		= ext4_write_info,
1646 	.alloc_dquot		= dquot_alloc,
1647 	.destroy_dquot		= dquot_destroy,
1648 	.get_projid		= ext4_get_projid,
1649 	.get_inode_usage	= ext4_get_inode_usage,
1650 	.get_next_id		= dquot_get_next_id,
1651 };
1652 
1653 static const struct quotactl_ops ext4_qctl_operations = {
1654 	.quota_on	= ext4_quota_on,
1655 	.quota_off	= ext4_quota_off,
1656 	.quota_sync	= dquot_quota_sync,
1657 	.get_state	= dquot_get_state,
1658 	.set_info	= dquot_set_dqinfo,
1659 	.get_dqblk	= dquot_get_dqblk,
1660 	.set_dqblk	= dquot_set_dqblk,
1661 	.get_nextdqblk	= dquot_get_next_dqblk,
1662 };
1663 #endif
1664 
1665 static const struct super_operations ext4_sops = {
1666 	.alloc_inode	= ext4_alloc_inode,
1667 	.free_inode	= ext4_free_in_core_inode,
1668 	.destroy_inode	= ext4_destroy_inode,
1669 	.write_inode	= ext4_write_inode,
1670 	.dirty_inode	= ext4_dirty_inode,
1671 	.drop_inode	= ext4_drop_inode,
1672 	.evict_inode	= ext4_evict_inode,
1673 	.put_super	= ext4_put_super,
1674 	.sync_fs	= ext4_sync_fs,
1675 	.freeze_fs	= ext4_freeze,
1676 	.unfreeze_fs	= ext4_unfreeze,
1677 	.statfs		= ext4_statfs,
1678 	.remount_fs	= ext4_remount,
1679 	.show_options	= ext4_show_options,
1680 #ifdef CONFIG_QUOTA
1681 	.quota_read	= ext4_quota_read,
1682 	.quota_write	= ext4_quota_write,
1683 	.get_dquots	= ext4_get_dquots,
1684 #endif
1685 	.bdev_try_to_free_page = bdev_try_to_free_page,
1686 };
1687 
1688 static const struct export_operations ext4_export_ops = {
1689 	.fh_to_dentry = ext4_fh_to_dentry,
1690 	.fh_to_parent = ext4_fh_to_parent,
1691 	.get_parent = ext4_get_parent,
1692 	.commit_metadata = ext4_nfs_commit_metadata,
1693 };
1694 
1695 enum {
1696 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1697 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1698 	Opt_nouid32, Opt_debug, Opt_removed,
1699 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1700 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1701 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1702 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1703 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1704 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1705 	Opt_inlinecrypt,
1706 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1707 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1708 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1709 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1710 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1711 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1712 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1713 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1714 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1715 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1716 	Opt_dioread_nolock, Opt_dioread_lock,
1717 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1718 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1719 	Opt_prefetch_block_bitmaps,
1720 #ifdef CONFIG_EXT4_DEBUG
1721 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1722 #endif
1723 };
1724 
1725 static const match_table_t tokens = {
1726 	{Opt_bsd_df, "bsddf"},
1727 	{Opt_minix_df, "minixdf"},
1728 	{Opt_grpid, "grpid"},
1729 	{Opt_grpid, "bsdgroups"},
1730 	{Opt_nogrpid, "nogrpid"},
1731 	{Opt_nogrpid, "sysvgroups"},
1732 	{Opt_resgid, "resgid=%u"},
1733 	{Opt_resuid, "resuid=%u"},
1734 	{Opt_sb, "sb=%u"},
1735 	{Opt_err_cont, "errors=continue"},
1736 	{Opt_err_panic, "errors=panic"},
1737 	{Opt_err_ro, "errors=remount-ro"},
1738 	{Opt_nouid32, "nouid32"},
1739 	{Opt_debug, "debug"},
1740 	{Opt_removed, "oldalloc"},
1741 	{Opt_removed, "orlov"},
1742 	{Opt_user_xattr, "user_xattr"},
1743 	{Opt_nouser_xattr, "nouser_xattr"},
1744 	{Opt_acl, "acl"},
1745 	{Opt_noacl, "noacl"},
1746 	{Opt_noload, "norecovery"},
1747 	{Opt_noload, "noload"},
1748 	{Opt_removed, "nobh"},
1749 	{Opt_removed, "bh"},
1750 	{Opt_commit, "commit=%u"},
1751 	{Opt_min_batch_time, "min_batch_time=%u"},
1752 	{Opt_max_batch_time, "max_batch_time=%u"},
1753 	{Opt_journal_dev, "journal_dev=%u"},
1754 	{Opt_journal_path, "journal_path=%s"},
1755 	{Opt_journal_checksum, "journal_checksum"},
1756 	{Opt_nojournal_checksum, "nojournal_checksum"},
1757 	{Opt_journal_async_commit, "journal_async_commit"},
1758 	{Opt_abort, "abort"},
1759 	{Opt_data_journal, "data=journal"},
1760 	{Opt_data_ordered, "data=ordered"},
1761 	{Opt_data_writeback, "data=writeback"},
1762 	{Opt_data_err_abort, "data_err=abort"},
1763 	{Opt_data_err_ignore, "data_err=ignore"},
1764 	{Opt_offusrjquota, "usrjquota="},
1765 	{Opt_usrjquota, "usrjquota=%s"},
1766 	{Opt_offgrpjquota, "grpjquota="},
1767 	{Opt_grpjquota, "grpjquota=%s"},
1768 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1769 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1770 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1771 	{Opt_grpquota, "grpquota"},
1772 	{Opt_noquota, "noquota"},
1773 	{Opt_quota, "quota"},
1774 	{Opt_usrquota, "usrquota"},
1775 	{Opt_prjquota, "prjquota"},
1776 	{Opt_barrier, "barrier=%u"},
1777 	{Opt_barrier, "barrier"},
1778 	{Opt_nobarrier, "nobarrier"},
1779 	{Opt_i_version, "i_version"},
1780 	{Opt_dax, "dax"},
1781 	{Opt_dax_always, "dax=always"},
1782 	{Opt_dax_inode, "dax=inode"},
1783 	{Opt_dax_never, "dax=never"},
1784 	{Opt_stripe, "stripe=%u"},
1785 	{Opt_delalloc, "delalloc"},
1786 	{Opt_warn_on_error, "warn_on_error"},
1787 	{Opt_nowarn_on_error, "nowarn_on_error"},
1788 	{Opt_lazytime, "lazytime"},
1789 	{Opt_nolazytime, "nolazytime"},
1790 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1791 	{Opt_nodelalloc, "nodelalloc"},
1792 	{Opt_removed, "mblk_io_submit"},
1793 	{Opt_removed, "nomblk_io_submit"},
1794 	{Opt_block_validity, "block_validity"},
1795 	{Opt_noblock_validity, "noblock_validity"},
1796 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1797 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1798 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1799 	{Opt_auto_da_alloc, "auto_da_alloc"},
1800 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1801 	{Opt_dioread_nolock, "dioread_nolock"},
1802 	{Opt_dioread_lock, "nodioread_nolock"},
1803 	{Opt_dioread_lock, "dioread_lock"},
1804 	{Opt_discard, "discard"},
1805 	{Opt_nodiscard, "nodiscard"},
1806 	{Opt_init_itable, "init_itable=%u"},
1807 	{Opt_init_itable, "init_itable"},
1808 	{Opt_noinit_itable, "noinit_itable"},
1809 #ifdef CONFIG_EXT4_DEBUG
1810 	{Opt_fc_debug_force, "fc_debug_force"},
1811 	{Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
1812 #endif
1813 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1814 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1815 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1816 	{Opt_inlinecrypt, "inlinecrypt"},
1817 	{Opt_nombcache, "nombcache"},
1818 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1819 	{Opt_prefetch_block_bitmaps, "prefetch_block_bitmaps"},
1820 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1821 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1822 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1823 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1824 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1825 	{Opt_err, NULL},
1826 };
1827 
1828 static ext4_fsblk_t get_sb_block(void **data)
1829 {
1830 	ext4_fsblk_t	sb_block;
1831 	char		*options = (char *) *data;
1832 
1833 	if (!options || strncmp(options, "sb=", 3) != 0)
1834 		return 1;	/* Default location */
1835 
1836 	options += 3;
1837 	/* TODO: use simple_strtoll with >32bit ext4 */
1838 	sb_block = simple_strtoul(options, &options, 0);
1839 	if (*options && *options != ',') {
1840 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1841 		       (char *) *data);
1842 		return 1;
1843 	}
1844 	if (*options == ',')
1845 		options++;
1846 	*data = (void *) options;
1847 
1848 	return sb_block;
1849 }
1850 
1851 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1852 static const char deprecated_msg[] =
1853 	"Mount option \"%s\" will be removed by %s\n"
1854 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1855 
1856 #ifdef CONFIG_QUOTA
1857 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1858 {
1859 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1860 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1861 	int ret = -1;
1862 
1863 	if (sb_any_quota_loaded(sb) && !old_qname) {
1864 		ext4_msg(sb, KERN_ERR,
1865 			"Cannot change journaled "
1866 			"quota options when quota turned on");
1867 		return -1;
1868 	}
1869 	if (ext4_has_feature_quota(sb)) {
1870 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1871 			 "ignored when QUOTA feature is enabled");
1872 		return 1;
1873 	}
1874 	qname = match_strdup(args);
1875 	if (!qname) {
1876 		ext4_msg(sb, KERN_ERR,
1877 			"Not enough memory for storing quotafile name");
1878 		return -1;
1879 	}
1880 	if (old_qname) {
1881 		if (strcmp(old_qname, qname) == 0)
1882 			ret = 1;
1883 		else
1884 			ext4_msg(sb, KERN_ERR,
1885 				 "%s quota file already specified",
1886 				 QTYPE2NAME(qtype));
1887 		goto errout;
1888 	}
1889 	if (strchr(qname, '/')) {
1890 		ext4_msg(sb, KERN_ERR,
1891 			"quotafile must be on filesystem root");
1892 		goto errout;
1893 	}
1894 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1895 	set_opt(sb, QUOTA);
1896 	return 1;
1897 errout:
1898 	kfree(qname);
1899 	return ret;
1900 }
1901 
1902 static int clear_qf_name(struct super_block *sb, int qtype)
1903 {
1904 
1905 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1906 	char *old_qname = get_qf_name(sb, sbi, qtype);
1907 
1908 	if (sb_any_quota_loaded(sb) && old_qname) {
1909 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1910 			" when quota turned on");
1911 		return -1;
1912 	}
1913 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1914 	synchronize_rcu();
1915 	kfree(old_qname);
1916 	return 1;
1917 }
1918 #endif
1919 
1920 #define MOPT_SET	0x0001
1921 #define MOPT_CLEAR	0x0002
1922 #define MOPT_NOSUPPORT	0x0004
1923 #define MOPT_EXPLICIT	0x0008
1924 #define MOPT_CLEAR_ERR	0x0010
1925 #define MOPT_GTE0	0x0020
1926 #ifdef CONFIG_QUOTA
1927 #define MOPT_Q		0
1928 #define MOPT_QFMT	0x0040
1929 #else
1930 #define MOPT_Q		MOPT_NOSUPPORT
1931 #define MOPT_QFMT	MOPT_NOSUPPORT
1932 #endif
1933 #define MOPT_DATAJ	0x0080
1934 #define MOPT_NO_EXT2	0x0100
1935 #define MOPT_NO_EXT3	0x0200
1936 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1937 #define MOPT_STRING	0x0400
1938 #define MOPT_SKIP	0x0800
1939 #define	MOPT_2		0x1000
1940 
1941 static const struct mount_opts {
1942 	int	token;
1943 	int	mount_opt;
1944 	int	flags;
1945 } ext4_mount_opts[] = {
1946 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1947 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1948 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1949 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1950 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1951 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1952 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1953 	 MOPT_EXT4_ONLY | MOPT_SET},
1954 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1955 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1956 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1957 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1958 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1959 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1960 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1961 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1962 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1963 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1964 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1965 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1966 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1967 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1968 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1969 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1970 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1971 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1972 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1973 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1974 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1975 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1976 	 MOPT_NO_EXT2},
1977 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1978 	 MOPT_NO_EXT2},
1979 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1980 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1981 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1982 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1983 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1984 	{Opt_commit, 0, MOPT_GTE0},
1985 	{Opt_max_batch_time, 0, MOPT_GTE0},
1986 	{Opt_min_batch_time, 0, MOPT_GTE0},
1987 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1988 	{Opt_init_itable, 0, MOPT_GTE0},
1989 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1990 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1991 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1992 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1993 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1994 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1995 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1996 	{Opt_stripe, 0, MOPT_GTE0},
1997 	{Opt_resuid, 0, MOPT_GTE0},
1998 	{Opt_resgid, 0, MOPT_GTE0},
1999 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
2000 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
2001 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
2002 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
2003 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
2004 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
2005 	 MOPT_NO_EXT2 | MOPT_DATAJ},
2006 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
2007 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
2008 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2009 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
2010 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
2011 #else
2012 	{Opt_acl, 0, MOPT_NOSUPPORT},
2013 	{Opt_noacl, 0, MOPT_NOSUPPORT},
2014 #endif
2015 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
2016 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
2017 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
2018 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
2019 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
2020 							MOPT_SET | MOPT_Q},
2021 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
2022 							MOPT_SET | MOPT_Q},
2023 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
2024 							MOPT_SET | MOPT_Q},
2025 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2026 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
2027 							MOPT_CLEAR | MOPT_Q},
2028 	{Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
2029 	{Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
2030 	{Opt_offusrjquota, 0, MOPT_Q},
2031 	{Opt_offgrpjquota, 0, MOPT_Q},
2032 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
2033 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
2034 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
2035 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
2036 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
2037 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
2038 	{Opt_prefetch_block_bitmaps, EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS,
2039 	 MOPT_SET},
2040 #ifdef CONFIG_EXT4_DEBUG
2041 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2042 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
2043 	{Opt_fc_debug_max_replay, 0, MOPT_GTE0},
2044 #endif
2045 	{Opt_err, 0, 0}
2046 };
2047 
2048 #ifdef CONFIG_UNICODE
2049 static const struct ext4_sb_encodings {
2050 	__u16 magic;
2051 	char *name;
2052 	char *version;
2053 } ext4_sb_encoding_map[] = {
2054 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
2055 };
2056 
2057 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
2058 				 const struct ext4_sb_encodings **encoding,
2059 				 __u16 *flags)
2060 {
2061 	__u16 magic = le16_to_cpu(es->s_encoding);
2062 	int i;
2063 
2064 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
2065 		if (magic == ext4_sb_encoding_map[i].magic)
2066 			break;
2067 
2068 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
2069 		return -EINVAL;
2070 
2071 	*encoding = &ext4_sb_encoding_map[i];
2072 	*flags = le16_to_cpu(es->s_encoding_flags);
2073 
2074 	return 0;
2075 }
2076 #endif
2077 
2078 static int ext4_set_test_dummy_encryption(struct super_block *sb,
2079 					  const char *opt,
2080 					  const substring_t *arg,
2081 					  bool is_remount)
2082 {
2083 #ifdef CONFIG_FS_ENCRYPTION
2084 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2085 	int err;
2086 
2087 	/*
2088 	 * This mount option is just for testing, and it's not worthwhile to
2089 	 * implement the extra complexity (e.g. RCU protection) that would be
2090 	 * needed to allow it to be set or changed during remount.  We do allow
2091 	 * it to be specified during remount, but only if there is no change.
2092 	 */
2093 	if (is_remount && !sbi->s_dummy_enc_policy.policy) {
2094 		ext4_msg(sb, KERN_WARNING,
2095 			 "Can't set test_dummy_encryption on remount");
2096 		return -1;
2097 	}
2098 	err = fscrypt_set_test_dummy_encryption(sb, arg->from,
2099 						&sbi->s_dummy_enc_policy);
2100 	if (err) {
2101 		if (err == -EEXIST)
2102 			ext4_msg(sb, KERN_WARNING,
2103 				 "Can't change test_dummy_encryption on remount");
2104 		else if (err == -EINVAL)
2105 			ext4_msg(sb, KERN_WARNING,
2106 				 "Value of option \"%s\" is unrecognized", opt);
2107 		else
2108 			ext4_msg(sb, KERN_WARNING,
2109 				 "Error processing option \"%s\" [%d]",
2110 				 opt, err);
2111 		return -1;
2112 	}
2113 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2114 #else
2115 	ext4_msg(sb, KERN_WARNING,
2116 		 "Test dummy encryption mount option ignored");
2117 #endif
2118 	return 1;
2119 }
2120 
2121 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
2122 			    substring_t *args, unsigned long *journal_devnum,
2123 			    unsigned int *journal_ioprio, int is_remount)
2124 {
2125 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2126 	const struct mount_opts *m;
2127 	kuid_t uid;
2128 	kgid_t gid;
2129 	int arg = 0;
2130 
2131 #ifdef CONFIG_QUOTA
2132 	if (token == Opt_usrjquota)
2133 		return set_qf_name(sb, USRQUOTA, &args[0]);
2134 	else if (token == Opt_grpjquota)
2135 		return set_qf_name(sb, GRPQUOTA, &args[0]);
2136 	else if (token == Opt_offusrjquota)
2137 		return clear_qf_name(sb, USRQUOTA);
2138 	else if (token == Opt_offgrpjquota)
2139 		return clear_qf_name(sb, GRPQUOTA);
2140 #endif
2141 	switch (token) {
2142 	case Opt_noacl:
2143 	case Opt_nouser_xattr:
2144 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
2145 		break;
2146 	case Opt_sb:
2147 		return 1;	/* handled by get_sb_block() */
2148 	case Opt_removed:
2149 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
2150 		return 1;
2151 	case Opt_abort:
2152 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
2153 		return 1;
2154 	case Opt_i_version:
2155 		sb->s_flags |= SB_I_VERSION;
2156 		return 1;
2157 	case Opt_lazytime:
2158 		sb->s_flags |= SB_LAZYTIME;
2159 		return 1;
2160 	case Opt_nolazytime:
2161 		sb->s_flags &= ~SB_LAZYTIME;
2162 		return 1;
2163 	case Opt_inlinecrypt:
2164 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2165 		sb->s_flags |= SB_INLINECRYPT;
2166 #else
2167 		ext4_msg(sb, KERN_ERR, "inline encryption not supported");
2168 #endif
2169 		return 1;
2170 	}
2171 
2172 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2173 		if (token == m->token)
2174 			break;
2175 
2176 	if (m->token == Opt_err) {
2177 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
2178 			 "or missing value", opt);
2179 		return -1;
2180 	}
2181 
2182 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2183 		ext4_msg(sb, KERN_ERR,
2184 			 "Mount option \"%s\" incompatible with ext2", opt);
2185 		return -1;
2186 	}
2187 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2188 		ext4_msg(sb, KERN_ERR,
2189 			 "Mount option \"%s\" incompatible with ext3", opt);
2190 		return -1;
2191 	}
2192 
2193 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
2194 		return -1;
2195 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
2196 		return -1;
2197 	if (m->flags & MOPT_EXPLICIT) {
2198 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2199 			set_opt2(sb, EXPLICIT_DELALLOC);
2200 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2201 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
2202 		} else
2203 			return -1;
2204 	}
2205 	if (m->flags & MOPT_CLEAR_ERR)
2206 		clear_opt(sb, ERRORS_MASK);
2207 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
2208 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
2209 			 "options when quota turned on");
2210 		return -1;
2211 	}
2212 
2213 	if (m->flags & MOPT_NOSUPPORT) {
2214 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
2215 	} else if (token == Opt_commit) {
2216 		if (arg == 0)
2217 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
2218 		else if (arg > INT_MAX / HZ) {
2219 			ext4_msg(sb, KERN_ERR,
2220 				 "Invalid commit interval %d, "
2221 				 "must be smaller than %d",
2222 				 arg, INT_MAX / HZ);
2223 			return -1;
2224 		}
2225 		sbi->s_commit_interval = HZ * arg;
2226 	} else if (token == Opt_debug_want_extra_isize) {
2227 		if ((arg & 1) ||
2228 		    (arg < 4) ||
2229 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2230 			ext4_msg(sb, KERN_ERR,
2231 				 "Invalid want_extra_isize %d", arg);
2232 			return -1;
2233 		}
2234 		sbi->s_want_extra_isize = arg;
2235 	} else if (token == Opt_max_batch_time) {
2236 		sbi->s_max_batch_time = arg;
2237 	} else if (token == Opt_min_batch_time) {
2238 		sbi->s_min_batch_time = arg;
2239 	} else if (token == Opt_inode_readahead_blks) {
2240 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2241 			ext4_msg(sb, KERN_ERR,
2242 				 "EXT4-fs: inode_readahead_blks must be "
2243 				 "0 or a power of 2 smaller than 2^31");
2244 			return -1;
2245 		}
2246 		sbi->s_inode_readahead_blks = arg;
2247 	} else if (token == Opt_init_itable) {
2248 		set_opt(sb, INIT_INODE_TABLE);
2249 		if (!args->from)
2250 			arg = EXT4_DEF_LI_WAIT_MULT;
2251 		sbi->s_li_wait_mult = arg;
2252 	} else if (token == Opt_max_dir_size_kb) {
2253 		sbi->s_max_dir_size_kb = arg;
2254 #ifdef CONFIG_EXT4_DEBUG
2255 	} else if (token == Opt_fc_debug_max_replay) {
2256 		sbi->s_fc_debug_max_replay = arg;
2257 #endif
2258 	} else if (token == Opt_stripe) {
2259 		sbi->s_stripe = arg;
2260 	} else if (token == Opt_resuid) {
2261 		uid = make_kuid(current_user_ns(), arg);
2262 		if (!uid_valid(uid)) {
2263 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2264 			return -1;
2265 		}
2266 		sbi->s_resuid = uid;
2267 	} else if (token == Opt_resgid) {
2268 		gid = make_kgid(current_user_ns(), arg);
2269 		if (!gid_valid(gid)) {
2270 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2271 			return -1;
2272 		}
2273 		sbi->s_resgid = gid;
2274 	} else if (token == Opt_journal_dev) {
2275 		if (is_remount) {
2276 			ext4_msg(sb, KERN_ERR,
2277 				 "Cannot specify journal on remount");
2278 			return -1;
2279 		}
2280 		*journal_devnum = arg;
2281 	} else if (token == Opt_journal_path) {
2282 		char *journal_path;
2283 		struct inode *journal_inode;
2284 		struct path path;
2285 		int error;
2286 
2287 		if (is_remount) {
2288 			ext4_msg(sb, KERN_ERR,
2289 				 "Cannot specify journal on remount");
2290 			return -1;
2291 		}
2292 		journal_path = match_strdup(&args[0]);
2293 		if (!journal_path) {
2294 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2295 				"journal device string");
2296 			return -1;
2297 		}
2298 
2299 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2300 		if (error) {
2301 			ext4_msg(sb, KERN_ERR, "error: could not find "
2302 				"journal device path: error %d", error);
2303 			kfree(journal_path);
2304 			return -1;
2305 		}
2306 
2307 		journal_inode = d_inode(path.dentry);
2308 		if (!S_ISBLK(journal_inode->i_mode)) {
2309 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2310 				"is not a block device", journal_path);
2311 			path_put(&path);
2312 			kfree(journal_path);
2313 			return -1;
2314 		}
2315 
2316 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2317 		path_put(&path);
2318 		kfree(journal_path);
2319 	} else if (token == Opt_journal_ioprio) {
2320 		if (arg > 7) {
2321 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2322 				 " (must be 0-7)");
2323 			return -1;
2324 		}
2325 		*journal_ioprio =
2326 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2327 	} else if (token == Opt_test_dummy_encryption) {
2328 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2329 						      is_remount);
2330 	} else if (m->flags & MOPT_DATAJ) {
2331 		if (is_remount) {
2332 			if (!sbi->s_journal)
2333 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2334 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2335 				ext4_msg(sb, KERN_ERR,
2336 					 "Cannot change data mode on remount");
2337 				return -1;
2338 			}
2339 		} else {
2340 			clear_opt(sb, DATA_FLAGS);
2341 			sbi->s_mount_opt |= m->mount_opt;
2342 		}
2343 #ifdef CONFIG_QUOTA
2344 	} else if (m->flags & MOPT_QFMT) {
2345 		if (sb_any_quota_loaded(sb) &&
2346 		    sbi->s_jquota_fmt != m->mount_opt) {
2347 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2348 				 "quota options when quota turned on");
2349 			return -1;
2350 		}
2351 		if (ext4_has_feature_quota(sb)) {
2352 			ext4_msg(sb, KERN_INFO,
2353 				 "Quota format mount options ignored "
2354 				 "when QUOTA feature is enabled");
2355 			return 1;
2356 		}
2357 		sbi->s_jquota_fmt = m->mount_opt;
2358 #endif
2359 	} else if (token == Opt_dax || token == Opt_dax_always ||
2360 		   token == Opt_dax_inode || token == Opt_dax_never) {
2361 #ifdef CONFIG_FS_DAX
2362 		switch (token) {
2363 		case Opt_dax:
2364 		case Opt_dax_always:
2365 			if (is_remount &&
2366 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2367 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2368 			fail_dax_change_remount:
2369 				ext4_msg(sb, KERN_ERR, "can't change "
2370 					 "dax mount option while remounting");
2371 				return -1;
2372 			}
2373 			if (is_remount &&
2374 			    (test_opt(sb, DATA_FLAGS) ==
2375 			     EXT4_MOUNT_JOURNAL_DATA)) {
2376 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2377 					     "both data=journal and dax");
2378 				    return -1;
2379 			}
2380 			ext4_msg(sb, KERN_WARNING,
2381 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2382 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2383 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2384 			break;
2385 		case Opt_dax_never:
2386 			if (is_remount &&
2387 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2388 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2389 				goto fail_dax_change_remount;
2390 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2391 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2392 			break;
2393 		case Opt_dax_inode:
2394 			if (is_remount &&
2395 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2396 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2397 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2398 				goto fail_dax_change_remount;
2399 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2400 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2401 			/* Strictly for printing options */
2402 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2403 			break;
2404 		}
2405 #else
2406 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2407 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2408 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2409 		return -1;
2410 #endif
2411 	} else if (token == Opt_data_err_abort) {
2412 		sbi->s_mount_opt |= m->mount_opt;
2413 	} else if (token == Opt_data_err_ignore) {
2414 		sbi->s_mount_opt &= ~m->mount_opt;
2415 	} else {
2416 		if (!args->from)
2417 			arg = 1;
2418 		if (m->flags & MOPT_CLEAR)
2419 			arg = !arg;
2420 		else if (unlikely(!(m->flags & MOPT_SET))) {
2421 			ext4_msg(sb, KERN_WARNING,
2422 				 "buggy handling of option %s", opt);
2423 			WARN_ON(1);
2424 			return -1;
2425 		}
2426 		if (m->flags & MOPT_2) {
2427 			if (arg != 0)
2428 				sbi->s_mount_opt2 |= m->mount_opt;
2429 			else
2430 				sbi->s_mount_opt2 &= ~m->mount_opt;
2431 		} else {
2432 			if (arg != 0)
2433 				sbi->s_mount_opt |= m->mount_opt;
2434 			else
2435 				sbi->s_mount_opt &= ~m->mount_opt;
2436 		}
2437 	}
2438 	return 1;
2439 }
2440 
2441 static int parse_options(char *options, struct super_block *sb,
2442 			 unsigned long *journal_devnum,
2443 			 unsigned int *journal_ioprio,
2444 			 int is_remount)
2445 {
2446 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2447 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2448 	substring_t args[MAX_OPT_ARGS];
2449 	int token;
2450 
2451 	if (!options)
2452 		return 1;
2453 
2454 	while ((p = strsep(&options, ",")) != NULL) {
2455 		if (!*p)
2456 			continue;
2457 		/*
2458 		 * Initialize args struct so we know whether arg was
2459 		 * found; some options take optional arguments.
2460 		 */
2461 		args[0].to = args[0].from = NULL;
2462 		token = match_token(p, tokens, args);
2463 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2464 				     journal_ioprio, is_remount) < 0)
2465 			return 0;
2466 	}
2467 #ifdef CONFIG_QUOTA
2468 	/*
2469 	 * We do the test below only for project quotas. 'usrquota' and
2470 	 * 'grpquota' mount options are allowed even without quota feature
2471 	 * to support legacy quotas in quota files.
2472 	 */
2473 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2474 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2475 			 "Cannot enable project quota enforcement.");
2476 		return 0;
2477 	}
2478 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2479 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2480 	if (usr_qf_name || grp_qf_name) {
2481 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2482 			clear_opt(sb, USRQUOTA);
2483 
2484 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2485 			clear_opt(sb, GRPQUOTA);
2486 
2487 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2488 			ext4_msg(sb, KERN_ERR, "old and new quota "
2489 					"format mixing");
2490 			return 0;
2491 		}
2492 
2493 		if (!sbi->s_jquota_fmt) {
2494 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2495 					"not specified");
2496 			return 0;
2497 		}
2498 	}
2499 #endif
2500 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2501 		int blocksize =
2502 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2503 		if (blocksize < PAGE_SIZE)
2504 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2505 				 "experimental mount option 'dioread_nolock' "
2506 				 "for blocksize < PAGE_SIZE");
2507 	}
2508 	return 1;
2509 }
2510 
2511 static inline void ext4_show_quota_options(struct seq_file *seq,
2512 					   struct super_block *sb)
2513 {
2514 #if defined(CONFIG_QUOTA)
2515 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2516 	char *usr_qf_name, *grp_qf_name;
2517 
2518 	if (sbi->s_jquota_fmt) {
2519 		char *fmtname = "";
2520 
2521 		switch (sbi->s_jquota_fmt) {
2522 		case QFMT_VFS_OLD:
2523 			fmtname = "vfsold";
2524 			break;
2525 		case QFMT_VFS_V0:
2526 			fmtname = "vfsv0";
2527 			break;
2528 		case QFMT_VFS_V1:
2529 			fmtname = "vfsv1";
2530 			break;
2531 		}
2532 		seq_printf(seq, ",jqfmt=%s", fmtname);
2533 	}
2534 
2535 	rcu_read_lock();
2536 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2537 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2538 	if (usr_qf_name)
2539 		seq_show_option(seq, "usrjquota", usr_qf_name);
2540 	if (grp_qf_name)
2541 		seq_show_option(seq, "grpjquota", grp_qf_name);
2542 	rcu_read_unlock();
2543 #endif
2544 }
2545 
2546 static const char *token2str(int token)
2547 {
2548 	const struct match_token *t;
2549 
2550 	for (t = tokens; t->token != Opt_err; t++)
2551 		if (t->token == token && !strchr(t->pattern, '='))
2552 			break;
2553 	return t->pattern;
2554 }
2555 
2556 /*
2557  * Show an option if
2558  *  - it's set to a non-default value OR
2559  *  - if the per-sb default is different from the global default
2560  */
2561 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2562 			      int nodefs)
2563 {
2564 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2565 	struct ext4_super_block *es = sbi->s_es;
2566 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2567 	const struct mount_opts *m;
2568 	char sep = nodefs ? '\n' : ',';
2569 
2570 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2571 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2572 
2573 	if (sbi->s_sb_block != 1)
2574 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2575 
2576 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2577 		int want_set = m->flags & MOPT_SET;
2578 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2579 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2580 			continue;
2581 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2582 			continue; /* skip if same as the default */
2583 		if ((want_set &&
2584 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2585 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2586 			continue; /* select Opt_noFoo vs Opt_Foo */
2587 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2588 	}
2589 
2590 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2591 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2592 		SEQ_OPTS_PRINT("resuid=%u",
2593 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2594 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2595 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2596 		SEQ_OPTS_PRINT("resgid=%u",
2597 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2598 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2599 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2600 		SEQ_OPTS_PUTS("errors=remount-ro");
2601 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2602 		SEQ_OPTS_PUTS("errors=continue");
2603 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2604 		SEQ_OPTS_PUTS("errors=panic");
2605 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2606 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2607 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2608 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2609 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2610 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2611 	if (sb->s_flags & SB_I_VERSION)
2612 		SEQ_OPTS_PUTS("i_version");
2613 	if (nodefs || sbi->s_stripe)
2614 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2615 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2616 			(sbi->s_mount_opt ^ def_mount_opt)) {
2617 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2618 			SEQ_OPTS_PUTS("data=journal");
2619 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2620 			SEQ_OPTS_PUTS("data=ordered");
2621 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2622 			SEQ_OPTS_PUTS("data=writeback");
2623 	}
2624 	if (nodefs ||
2625 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2626 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2627 			       sbi->s_inode_readahead_blks);
2628 
2629 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2630 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2631 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2632 	if (nodefs || sbi->s_max_dir_size_kb)
2633 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2634 	if (test_opt(sb, DATA_ERR_ABORT))
2635 		SEQ_OPTS_PUTS("data_err=abort");
2636 
2637 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2638 
2639 	if (sb->s_flags & SB_INLINECRYPT)
2640 		SEQ_OPTS_PUTS("inlinecrypt");
2641 
2642 	if (test_opt(sb, DAX_ALWAYS)) {
2643 		if (IS_EXT2_SB(sb))
2644 			SEQ_OPTS_PUTS("dax");
2645 		else
2646 			SEQ_OPTS_PUTS("dax=always");
2647 	} else if (test_opt2(sb, DAX_NEVER)) {
2648 		SEQ_OPTS_PUTS("dax=never");
2649 	} else if (test_opt2(sb, DAX_INODE)) {
2650 		SEQ_OPTS_PUTS("dax=inode");
2651 	}
2652 
2653 	if (test_opt2(sb, JOURNAL_FAST_COMMIT))
2654 		SEQ_OPTS_PUTS("fast_commit");
2655 
2656 	ext4_show_quota_options(seq, sb);
2657 	return 0;
2658 }
2659 
2660 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2661 {
2662 	return _ext4_show_options(seq, root->d_sb, 0);
2663 }
2664 
2665 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2666 {
2667 	struct super_block *sb = seq->private;
2668 	int rc;
2669 
2670 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2671 	rc = _ext4_show_options(seq, sb, 1);
2672 	seq_puts(seq, "\n");
2673 	return rc;
2674 }
2675 
2676 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2677 			    int read_only)
2678 {
2679 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2680 	int err = 0;
2681 
2682 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2683 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2684 			 "forcing read-only mode");
2685 		err = -EROFS;
2686 		goto done;
2687 	}
2688 	if (read_only)
2689 		goto done;
2690 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2691 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2692 			 "running e2fsck is recommended");
2693 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2694 		ext4_msg(sb, KERN_WARNING,
2695 			 "warning: mounting fs with errors, "
2696 			 "running e2fsck is recommended");
2697 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2698 		 le16_to_cpu(es->s_mnt_count) >=
2699 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2700 		ext4_msg(sb, KERN_WARNING,
2701 			 "warning: maximal mount count reached, "
2702 			 "running e2fsck is recommended");
2703 	else if (le32_to_cpu(es->s_checkinterval) &&
2704 		 (ext4_get_tstamp(es, s_lastcheck) +
2705 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2706 		ext4_msg(sb, KERN_WARNING,
2707 			 "warning: checktime reached, "
2708 			 "running e2fsck is recommended");
2709 	if (!sbi->s_journal)
2710 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2711 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2712 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2713 	le16_add_cpu(&es->s_mnt_count, 1);
2714 	ext4_update_tstamp(es, s_mtime);
2715 	if (sbi->s_journal)
2716 		ext4_set_feature_journal_needs_recovery(sb);
2717 
2718 	err = ext4_commit_super(sb, 1);
2719 done:
2720 	if (test_opt(sb, DEBUG))
2721 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2722 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2723 			sb->s_blocksize,
2724 			sbi->s_groups_count,
2725 			EXT4_BLOCKS_PER_GROUP(sb),
2726 			EXT4_INODES_PER_GROUP(sb),
2727 			sbi->s_mount_opt, sbi->s_mount_opt2);
2728 
2729 	cleancache_init_fs(sb);
2730 	return err;
2731 }
2732 
2733 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2734 {
2735 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2736 	struct flex_groups **old_groups, **new_groups;
2737 	int size, i, j;
2738 
2739 	if (!sbi->s_log_groups_per_flex)
2740 		return 0;
2741 
2742 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2743 	if (size <= sbi->s_flex_groups_allocated)
2744 		return 0;
2745 
2746 	new_groups = kvzalloc(roundup_pow_of_two(size *
2747 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2748 	if (!new_groups) {
2749 		ext4_msg(sb, KERN_ERR,
2750 			 "not enough memory for %d flex group pointers", size);
2751 		return -ENOMEM;
2752 	}
2753 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2754 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2755 					 sizeof(struct flex_groups)),
2756 					 GFP_KERNEL);
2757 		if (!new_groups[i]) {
2758 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2759 				kvfree(new_groups[j]);
2760 			kvfree(new_groups);
2761 			ext4_msg(sb, KERN_ERR,
2762 				 "not enough memory for %d flex groups", size);
2763 			return -ENOMEM;
2764 		}
2765 	}
2766 	rcu_read_lock();
2767 	old_groups = rcu_dereference(sbi->s_flex_groups);
2768 	if (old_groups)
2769 		memcpy(new_groups, old_groups,
2770 		       (sbi->s_flex_groups_allocated *
2771 			sizeof(struct flex_groups *)));
2772 	rcu_read_unlock();
2773 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2774 	sbi->s_flex_groups_allocated = size;
2775 	if (old_groups)
2776 		ext4_kvfree_array_rcu(old_groups);
2777 	return 0;
2778 }
2779 
2780 static int ext4_fill_flex_info(struct super_block *sb)
2781 {
2782 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2783 	struct ext4_group_desc *gdp = NULL;
2784 	struct flex_groups *fg;
2785 	ext4_group_t flex_group;
2786 	int i, err;
2787 
2788 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2789 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2790 		sbi->s_log_groups_per_flex = 0;
2791 		return 1;
2792 	}
2793 
2794 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2795 	if (err)
2796 		goto failed;
2797 
2798 	for (i = 0; i < sbi->s_groups_count; i++) {
2799 		gdp = ext4_get_group_desc(sb, i, NULL);
2800 
2801 		flex_group = ext4_flex_group(sbi, i);
2802 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2803 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2804 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2805 			     &fg->free_clusters);
2806 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2807 	}
2808 
2809 	return 1;
2810 failed:
2811 	return 0;
2812 }
2813 
2814 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2815 				   struct ext4_group_desc *gdp)
2816 {
2817 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2818 	__u16 crc = 0;
2819 	__le32 le_group = cpu_to_le32(block_group);
2820 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2821 
2822 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2823 		/* Use new metadata_csum algorithm */
2824 		__u32 csum32;
2825 		__u16 dummy_csum = 0;
2826 
2827 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2828 				     sizeof(le_group));
2829 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2830 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2831 				     sizeof(dummy_csum));
2832 		offset += sizeof(dummy_csum);
2833 		if (offset < sbi->s_desc_size)
2834 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2835 					     sbi->s_desc_size - offset);
2836 
2837 		crc = csum32 & 0xFFFF;
2838 		goto out;
2839 	}
2840 
2841 	/* old crc16 code */
2842 	if (!ext4_has_feature_gdt_csum(sb))
2843 		return 0;
2844 
2845 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2846 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2847 	crc = crc16(crc, (__u8 *)gdp, offset);
2848 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2849 	/* for checksum of struct ext4_group_desc do the rest...*/
2850 	if (ext4_has_feature_64bit(sb) &&
2851 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2852 		crc = crc16(crc, (__u8 *)gdp + offset,
2853 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2854 				offset);
2855 
2856 out:
2857 	return cpu_to_le16(crc);
2858 }
2859 
2860 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2861 				struct ext4_group_desc *gdp)
2862 {
2863 	if (ext4_has_group_desc_csum(sb) &&
2864 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2865 		return 0;
2866 
2867 	return 1;
2868 }
2869 
2870 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2871 			      struct ext4_group_desc *gdp)
2872 {
2873 	if (!ext4_has_group_desc_csum(sb))
2874 		return;
2875 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2876 }
2877 
2878 /* Called at mount-time, super-block is locked */
2879 static int ext4_check_descriptors(struct super_block *sb,
2880 				  ext4_fsblk_t sb_block,
2881 				  ext4_group_t *first_not_zeroed)
2882 {
2883 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2884 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2885 	ext4_fsblk_t last_block;
2886 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2887 	ext4_fsblk_t block_bitmap;
2888 	ext4_fsblk_t inode_bitmap;
2889 	ext4_fsblk_t inode_table;
2890 	int flexbg_flag = 0;
2891 	ext4_group_t i, grp = sbi->s_groups_count;
2892 
2893 	if (ext4_has_feature_flex_bg(sb))
2894 		flexbg_flag = 1;
2895 
2896 	ext4_debug("Checking group descriptors");
2897 
2898 	for (i = 0; i < sbi->s_groups_count; i++) {
2899 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2900 
2901 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2902 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2903 		else
2904 			last_block = first_block +
2905 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2906 
2907 		if ((grp == sbi->s_groups_count) &&
2908 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2909 			grp = i;
2910 
2911 		block_bitmap = ext4_block_bitmap(sb, gdp);
2912 		if (block_bitmap == sb_block) {
2913 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2914 				 "Block bitmap for group %u overlaps "
2915 				 "superblock", i);
2916 			if (!sb_rdonly(sb))
2917 				return 0;
2918 		}
2919 		if (block_bitmap >= sb_block + 1 &&
2920 		    block_bitmap <= last_bg_block) {
2921 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2922 				 "Block bitmap for group %u overlaps "
2923 				 "block group descriptors", i);
2924 			if (!sb_rdonly(sb))
2925 				return 0;
2926 		}
2927 		if (block_bitmap < first_block || block_bitmap > last_block) {
2928 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2929 			       "Block bitmap for group %u not in group "
2930 			       "(block %llu)!", i, block_bitmap);
2931 			return 0;
2932 		}
2933 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2934 		if (inode_bitmap == sb_block) {
2935 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2936 				 "Inode bitmap for group %u overlaps "
2937 				 "superblock", i);
2938 			if (!sb_rdonly(sb))
2939 				return 0;
2940 		}
2941 		if (inode_bitmap >= sb_block + 1 &&
2942 		    inode_bitmap <= last_bg_block) {
2943 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2944 				 "Inode bitmap for group %u overlaps "
2945 				 "block group descriptors", i);
2946 			if (!sb_rdonly(sb))
2947 				return 0;
2948 		}
2949 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2950 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2951 			       "Inode bitmap for group %u not in group "
2952 			       "(block %llu)!", i, inode_bitmap);
2953 			return 0;
2954 		}
2955 		inode_table = ext4_inode_table(sb, gdp);
2956 		if (inode_table == sb_block) {
2957 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2958 				 "Inode table for group %u overlaps "
2959 				 "superblock", i);
2960 			if (!sb_rdonly(sb))
2961 				return 0;
2962 		}
2963 		if (inode_table >= sb_block + 1 &&
2964 		    inode_table <= last_bg_block) {
2965 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2966 				 "Inode table for group %u overlaps "
2967 				 "block group descriptors", i);
2968 			if (!sb_rdonly(sb))
2969 				return 0;
2970 		}
2971 		if (inode_table < first_block ||
2972 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2973 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2974 			       "Inode table for group %u not in group "
2975 			       "(block %llu)!", i, inode_table);
2976 			return 0;
2977 		}
2978 		ext4_lock_group(sb, i);
2979 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2980 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2981 				 "Checksum for group %u failed (%u!=%u)",
2982 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2983 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2984 			if (!sb_rdonly(sb)) {
2985 				ext4_unlock_group(sb, i);
2986 				return 0;
2987 			}
2988 		}
2989 		ext4_unlock_group(sb, i);
2990 		if (!flexbg_flag)
2991 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2992 	}
2993 	if (NULL != first_not_zeroed)
2994 		*first_not_zeroed = grp;
2995 	return 1;
2996 }
2997 
2998 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2999  * the superblock) which were deleted from all directories, but held open by
3000  * a process at the time of a crash.  We walk the list and try to delete these
3001  * inodes at recovery time (only with a read-write filesystem).
3002  *
3003  * In order to keep the orphan inode chain consistent during traversal (in
3004  * case of crash during recovery), we link each inode into the superblock
3005  * orphan list_head and handle it the same way as an inode deletion during
3006  * normal operation (which journals the operations for us).
3007  *
3008  * We only do an iget() and an iput() on each inode, which is very safe if we
3009  * accidentally point at an in-use or already deleted inode.  The worst that
3010  * can happen in this case is that we get a "bit already cleared" message from
3011  * ext4_free_inode().  The only reason we would point at a wrong inode is if
3012  * e2fsck was run on this filesystem, and it must have already done the orphan
3013  * inode cleanup for us, so we can safely abort without any further action.
3014  */
3015 static void ext4_orphan_cleanup(struct super_block *sb,
3016 				struct ext4_super_block *es)
3017 {
3018 	unsigned int s_flags = sb->s_flags;
3019 	int ret, nr_orphans = 0, nr_truncates = 0;
3020 #ifdef CONFIG_QUOTA
3021 	int quota_update = 0;
3022 	int i;
3023 #endif
3024 	if (!es->s_last_orphan) {
3025 		jbd_debug(4, "no orphan inodes to clean up\n");
3026 		return;
3027 	}
3028 
3029 	if (bdev_read_only(sb->s_bdev)) {
3030 		ext4_msg(sb, KERN_ERR, "write access "
3031 			"unavailable, skipping orphan cleanup");
3032 		return;
3033 	}
3034 
3035 	/* Check if feature set would not allow a r/w mount */
3036 	if (!ext4_feature_set_ok(sb, 0)) {
3037 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
3038 			 "unknown ROCOMPAT features");
3039 		return;
3040 	}
3041 
3042 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3043 		/* don't clear list on RO mount w/ errors */
3044 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
3045 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
3046 				  "clearing orphan list.\n");
3047 			es->s_last_orphan = 0;
3048 		}
3049 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3050 		return;
3051 	}
3052 
3053 	if (s_flags & SB_RDONLY) {
3054 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
3055 		sb->s_flags &= ~SB_RDONLY;
3056 	}
3057 #ifdef CONFIG_QUOTA
3058 	/* Needed for iput() to work correctly and not trash data */
3059 	sb->s_flags |= SB_ACTIVE;
3060 
3061 	/*
3062 	 * Turn on quotas which were not enabled for read-only mounts if
3063 	 * filesystem has quota feature, so that they are updated correctly.
3064 	 */
3065 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
3066 		int ret = ext4_enable_quotas(sb);
3067 
3068 		if (!ret)
3069 			quota_update = 1;
3070 		else
3071 			ext4_msg(sb, KERN_ERR,
3072 				"Cannot turn on quotas: error %d", ret);
3073 	}
3074 
3075 	/* Turn on journaled quotas used for old sytle */
3076 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3077 		if (EXT4_SB(sb)->s_qf_names[i]) {
3078 			int ret = ext4_quota_on_mount(sb, i);
3079 
3080 			if (!ret)
3081 				quota_update = 1;
3082 			else
3083 				ext4_msg(sb, KERN_ERR,
3084 					"Cannot turn on journaled "
3085 					"quota: type %d: error %d", i, ret);
3086 		}
3087 	}
3088 #endif
3089 
3090 	while (es->s_last_orphan) {
3091 		struct inode *inode;
3092 
3093 		/*
3094 		 * We may have encountered an error during cleanup; if
3095 		 * so, skip the rest.
3096 		 */
3097 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3098 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3099 			es->s_last_orphan = 0;
3100 			break;
3101 		}
3102 
3103 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
3104 		if (IS_ERR(inode)) {
3105 			es->s_last_orphan = 0;
3106 			break;
3107 		}
3108 
3109 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
3110 		dquot_initialize(inode);
3111 		if (inode->i_nlink) {
3112 			if (test_opt(sb, DEBUG))
3113 				ext4_msg(sb, KERN_DEBUG,
3114 					"%s: truncating inode %lu to %lld bytes",
3115 					__func__, inode->i_ino, inode->i_size);
3116 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
3117 				  inode->i_ino, inode->i_size);
3118 			inode_lock(inode);
3119 			truncate_inode_pages(inode->i_mapping, inode->i_size);
3120 			ret = ext4_truncate(inode);
3121 			if (ret)
3122 				ext4_std_error(inode->i_sb, ret);
3123 			inode_unlock(inode);
3124 			nr_truncates++;
3125 		} else {
3126 			if (test_opt(sb, DEBUG))
3127 				ext4_msg(sb, KERN_DEBUG,
3128 					"%s: deleting unreferenced inode %lu",
3129 					__func__, inode->i_ino);
3130 			jbd_debug(2, "deleting unreferenced inode %lu\n",
3131 				  inode->i_ino);
3132 			nr_orphans++;
3133 		}
3134 		iput(inode);  /* The delete magic happens here! */
3135 	}
3136 
3137 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
3138 
3139 	if (nr_orphans)
3140 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
3141 		       PLURAL(nr_orphans));
3142 	if (nr_truncates)
3143 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
3144 		       PLURAL(nr_truncates));
3145 #ifdef CONFIG_QUOTA
3146 	/* Turn off quotas if they were enabled for orphan cleanup */
3147 	if (quota_update) {
3148 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3149 			if (sb_dqopt(sb)->files[i])
3150 				dquot_quota_off(sb, i);
3151 		}
3152 	}
3153 #endif
3154 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
3155 }
3156 
3157 /*
3158  * Maximal extent format file size.
3159  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3160  * extent format containers, within a sector_t, and within i_blocks
3161  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3162  * so that won't be a limiting factor.
3163  *
3164  * However there is other limiting factor. We do store extents in the form
3165  * of starting block and length, hence the resulting length of the extent
3166  * covering maximum file size must fit into on-disk format containers as
3167  * well. Given that length is always by 1 unit bigger than max unit (because
3168  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3169  *
3170  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3171  */
3172 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3173 {
3174 	loff_t res;
3175 	loff_t upper_limit = MAX_LFS_FILESIZE;
3176 
3177 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3178 
3179 	if (!has_huge_files) {
3180 		upper_limit = (1LL << 32) - 1;
3181 
3182 		/* total blocks in file system block size */
3183 		upper_limit >>= (blkbits - 9);
3184 		upper_limit <<= blkbits;
3185 	}
3186 
3187 	/*
3188 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3189 	 * by one fs block, so ee_len can cover the extent of maximum file
3190 	 * size
3191 	 */
3192 	res = (1LL << 32) - 1;
3193 	res <<= blkbits;
3194 
3195 	/* Sanity check against vm- & vfs- imposed limits */
3196 	if (res > upper_limit)
3197 		res = upper_limit;
3198 
3199 	return res;
3200 }
3201 
3202 /*
3203  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3204  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3205  * We need to be 1 filesystem block less than the 2^48 sector limit.
3206  */
3207 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3208 {
3209 	loff_t res = EXT4_NDIR_BLOCKS;
3210 	int meta_blocks;
3211 	loff_t upper_limit;
3212 	/* This is calculated to be the largest file size for a dense, block
3213 	 * mapped file such that the file's total number of 512-byte sectors,
3214 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3215 	 *
3216 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3217 	 * number of 512-byte sectors of the file.
3218 	 */
3219 
3220 	if (!has_huge_files) {
3221 		/*
3222 		 * !has_huge_files or implies that the inode i_block field
3223 		 * represents total file blocks in 2^32 512-byte sectors ==
3224 		 * size of vfs inode i_blocks * 8
3225 		 */
3226 		upper_limit = (1LL << 32) - 1;
3227 
3228 		/* total blocks in file system block size */
3229 		upper_limit >>= (bits - 9);
3230 
3231 	} else {
3232 		/*
3233 		 * We use 48 bit ext4_inode i_blocks
3234 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3235 		 * represent total number of blocks in
3236 		 * file system block size
3237 		 */
3238 		upper_limit = (1LL << 48) - 1;
3239 
3240 	}
3241 
3242 	/* indirect blocks */
3243 	meta_blocks = 1;
3244 	/* double indirect blocks */
3245 	meta_blocks += 1 + (1LL << (bits-2));
3246 	/* tripple indirect blocks */
3247 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3248 
3249 	upper_limit -= meta_blocks;
3250 	upper_limit <<= bits;
3251 
3252 	res += 1LL << (bits-2);
3253 	res += 1LL << (2*(bits-2));
3254 	res += 1LL << (3*(bits-2));
3255 	res <<= bits;
3256 	if (res > upper_limit)
3257 		res = upper_limit;
3258 
3259 	if (res > MAX_LFS_FILESIZE)
3260 		res = MAX_LFS_FILESIZE;
3261 
3262 	return res;
3263 }
3264 
3265 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3266 				   ext4_fsblk_t logical_sb_block, int nr)
3267 {
3268 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3269 	ext4_group_t bg, first_meta_bg;
3270 	int has_super = 0;
3271 
3272 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3273 
3274 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3275 		return logical_sb_block + nr + 1;
3276 	bg = sbi->s_desc_per_block * nr;
3277 	if (ext4_bg_has_super(sb, bg))
3278 		has_super = 1;
3279 
3280 	/*
3281 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3282 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3283 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3284 	 * compensate.
3285 	 */
3286 	if (sb->s_blocksize == 1024 && nr == 0 &&
3287 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3288 		has_super++;
3289 
3290 	return (has_super + ext4_group_first_block_no(sb, bg));
3291 }
3292 
3293 /**
3294  * ext4_get_stripe_size: Get the stripe size.
3295  * @sbi: In memory super block info
3296  *
3297  * If we have specified it via mount option, then
3298  * use the mount option value. If the value specified at mount time is
3299  * greater than the blocks per group use the super block value.
3300  * If the super block value is greater than blocks per group return 0.
3301  * Allocator needs it be less than blocks per group.
3302  *
3303  */
3304 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3305 {
3306 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3307 	unsigned long stripe_width =
3308 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3309 	int ret;
3310 
3311 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3312 		ret = sbi->s_stripe;
3313 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3314 		ret = stripe_width;
3315 	else if (stride && stride <= sbi->s_blocks_per_group)
3316 		ret = stride;
3317 	else
3318 		ret = 0;
3319 
3320 	/*
3321 	 * If the stripe width is 1, this makes no sense and
3322 	 * we set it to 0 to turn off stripe handling code.
3323 	 */
3324 	if (ret <= 1)
3325 		ret = 0;
3326 
3327 	return ret;
3328 }
3329 
3330 /*
3331  * Check whether this filesystem can be mounted based on
3332  * the features present and the RDONLY/RDWR mount requested.
3333  * Returns 1 if this filesystem can be mounted as requested,
3334  * 0 if it cannot be.
3335  */
3336 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3337 {
3338 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3339 		ext4_msg(sb, KERN_ERR,
3340 			"Couldn't mount because of "
3341 			"unsupported optional features (%x)",
3342 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3343 			~EXT4_FEATURE_INCOMPAT_SUPP));
3344 		return 0;
3345 	}
3346 
3347 #ifndef CONFIG_UNICODE
3348 	if (ext4_has_feature_casefold(sb)) {
3349 		ext4_msg(sb, KERN_ERR,
3350 			 "Filesystem with casefold feature cannot be "
3351 			 "mounted without CONFIG_UNICODE");
3352 		return 0;
3353 	}
3354 #endif
3355 
3356 	if (readonly)
3357 		return 1;
3358 
3359 	if (ext4_has_feature_readonly(sb)) {
3360 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3361 		sb->s_flags |= SB_RDONLY;
3362 		return 1;
3363 	}
3364 
3365 	/* Check that feature set is OK for a read-write mount */
3366 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3367 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3368 			 "unsupported optional features (%x)",
3369 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3370 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3371 		return 0;
3372 	}
3373 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3374 		ext4_msg(sb, KERN_ERR,
3375 			 "Can't support bigalloc feature without "
3376 			 "extents feature\n");
3377 		return 0;
3378 	}
3379 
3380 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3381 	if (!readonly && (ext4_has_feature_quota(sb) ||
3382 			  ext4_has_feature_project(sb))) {
3383 		ext4_msg(sb, KERN_ERR,
3384 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3385 		return 0;
3386 	}
3387 #endif  /* CONFIG_QUOTA */
3388 	return 1;
3389 }
3390 
3391 /*
3392  * This function is called once a day if we have errors logged
3393  * on the file system
3394  */
3395 static void print_daily_error_info(struct timer_list *t)
3396 {
3397 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3398 	struct super_block *sb = sbi->s_sb;
3399 	struct ext4_super_block *es = sbi->s_es;
3400 
3401 	if (es->s_error_count)
3402 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3403 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3404 			 le32_to_cpu(es->s_error_count));
3405 	if (es->s_first_error_time) {
3406 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3407 		       sb->s_id,
3408 		       ext4_get_tstamp(es, s_first_error_time),
3409 		       (int) sizeof(es->s_first_error_func),
3410 		       es->s_first_error_func,
3411 		       le32_to_cpu(es->s_first_error_line));
3412 		if (es->s_first_error_ino)
3413 			printk(KERN_CONT ": inode %u",
3414 			       le32_to_cpu(es->s_first_error_ino));
3415 		if (es->s_first_error_block)
3416 			printk(KERN_CONT ": block %llu", (unsigned long long)
3417 			       le64_to_cpu(es->s_first_error_block));
3418 		printk(KERN_CONT "\n");
3419 	}
3420 	if (es->s_last_error_time) {
3421 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3422 		       sb->s_id,
3423 		       ext4_get_tstamp(es, s_last_error_time),
3424 		       (int) sizeof(es->s_last_error_func),
3425 		       es->s_last_error_func,
3426 		       le32_to_cpu(es->s_last_error_line));
3427 		if (es->s_last_error_ino)
3428 			printk(KERN_CONT ": inode %u",
3429 			       le32_to_cpu(es->s_last_error_ino));
3430 		if (es->s_last_error_block)
3431 			printk(KERN_CONT ": block %llu", (unsigned long long)
3432 			       le64_to_cpu(es->s_last_error_block));
3433 		printk(KERN_CONT "\n");
3434 	}
3435 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3436 }
3437 
3438 /* Find next suitable group and run ext4_init_inode_table */
3439 static int ext4_run_li_request(struct ext4_li_request *elr)
3440 {
3441 	struct ext4_group_desc *gdp = NULL;
3442 	struct super_block *sb = elr->lr_super;
3443 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3444 	ext4_group_t group = elr->lr_next_group;
3445 	unsigned long timeout = 0;
3446 	unsigned int prefetch_ios = 0;
3447 	int ret = 0;
3448 
3449 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3450 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3451 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3452 		if (prefetch_ios)
3453 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3454 					      prefetch_ios);
3455 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3456 					    prefetch_ios);
3457 		if (group >= elr->lr_next_group) {
3458 			ret = 1;
3459 			if (elr->lr_first_not_zeroed != ngroups &&
3460 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3461 				elr->lr_next_group = elr->lr_first_not_zeroed;
3462 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3463 				ret = 0;
3464 			}
3465 		}
3466 		return ret;
3467 	}
3468 
3469 	for (; group < ngroups; group++) {
3470 		gdp = ext4_get_group_desc(sb, group, NULL);
3471 		if (!gdp) {
3472 			ret = 1;
3473 			break;
3474 		}
3475 
3476 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3477 			break;
3478 	}
3479 
3480 	if (group >= ngroups)
3481 		ret = 1;
3482 
3483 	if (!ret) {
3484 		timeout = jiffies;
3485 		ret = ext4_init_inode_table(sb, group,
3486 					    elr->lr_timeout ? 0 : 1);
3487 		trace_ext4_lazy_itable_init(sb, group);
3488 		if (elr->lr_timeout == 0) {
3489 			timeout = (jiffies - timeout) *
3490 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3491 			elr->lr_timeout = timeout;
3492 		}
3493 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3494 		elr->lr_next_group = group + 1;
3495 	}
3496 	return ret;
3497 }
3498 
3499 /*
3500  * Remove lr_request from the list_request and free the
3501  * request structure. Should be called with li_list_mtx held
3502  */
3503 static void ext4_remove_li_request(struct ext4_li_request *elr)
3504 {
3505 	if (!elr)
3506 		return;
3507 
3508 	list_del(&elr->lr_request);
3509 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3510 	kfree(elr);
3511 }
3512 
3513 static void ext4_unregister_li_request(struct super_block *sb)
3514 {
3515 	mutex_lock(&ext4_li_mtx);
3516 	if (!ext4_li_info) {
3517 		mutex_unlock(&ext4_li_mtx);
3518 		return;
3519 	}
3520 
3521 	mutex_lock(&ext4_li_info->li_list_mtx);
3522 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3523 	mutex_unlock(&ext4_li_info->li_list_mtx);
3524 	mutex_unlock(&ext4_li_mtx);
3525 }
3526 
3527 static struct task_struct *ext4_lazyinit_task;
3528 
3529 /*
3530  * This is the function where ext4lazyinit thread lives. It walks
3531  * through the request list searching for next scheduled filesystem.
3532  * When such a fs is found, run the lazy initialization request
3533  * (ext4_rn_li_request) and keep track of the time spend in this
3534  * function. Based on that time we compute next schedule time of
3535  * the request. When walking through the list is complete, compute
3536  * next waking time and put itself into sleep.
3537  */
3538 static int ext4_lazyinit_thread(void *arg)
3539 {
3540 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3541 	struct list_head *pos, *n;
3542 	struct ext4_li_request *elr;
3543 	unsigned long next_wakeup, cur;
3544 
3545 	BUG_ON(NULL == eli);
3546 
3547 cont_thread:
3548 	while (true) {
3549 		next_wakeup = MAX_JIFFY_OFFSET;
3550 
3551 		mutex_lock(&eli->li_list_mtx);
3552 		if (list_empty(&eli->li_request_list)) {
3553 			mutex_unlock(&eli->li_list_mtx);
3554 			goto exit_thread;
3555 		}
3556 		list_for_each_safe(pos, n, &eli->li_request_list) {
3557 			int err = 0;
3558 			int progress = 0;
3559 			elr = list_entry(pos, struct ext4_li_request,
3560 					 lr_request);
3561 
3562 			if (time_before(jiffies, elr->lr_next_sched)) {
3563 				if (time_before(elr->lr_next_sched, next_wakeup))
3564 					next_wakeup = elr->lr_next_sched;
3565 				continue;
3566 			}
3567 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3568 				if (sb_start_write_trylock(elr->lr_super)) {
3569 					progress = 1;
3570 					/*
3571 					 * We hold sb->s_umount, sb can not
3572 					 * be removed from the list, it is
3573 					 * now safe to drop li_list_mtx
3574 					 */
3575 					mutex_unlock(&eli->li_list_mtx);
3576 					err = ext4_run_li_request(elr);
3577 					sb_end_write(elr->lr_super);
3578 					mutex_lock(&eli->li_list_mtx);
3579 					n = pos->next;
3580 				}
3581 				up_read((&elr->lr_super->s_umount));
3582 			}
3583 			/* error, remove the lazy_init job */
3584 			if (err) {
3585 				ext4_remove_li_request(elr);
3586 				continue;
3587 			}
3588 			if (!progress) {
3589 				elr->lr_next_sched = jiffies +
3590 					(prandom_u32()
3591 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3592 			}
3593 			if (time_before(elr->lr_next_sched, next_wakeup))
3594 				next_wakeup = elr->lr_next_sched;
3595 		}
3596 		mutex_unlock(&eli->li_list_mtx);
3597 
3598 		try_to_freeze();
3599 
3600 		cur = jiffies;
3601 		if ((time_after_eq(cur, next_wakeup)) ||
3602 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3603 			cond_resched();
3604 			continue;
3605 		}
3606 
3607 		schedule_timeout_interruptible(next_wakeup - cur);
3608 
3609 		if (kthread_should_stop()) {
3610 			ext4_clear_request_list();
3611 			goto exit_thread;
3612 		}
3613 	}
3614 
3615 exit_thread:
3616 	/*
3617 	 * It looks like the request list is empty, but we need
3618 	 * to check it under the li_list_mtx lock, to prevent any
3619 	 * additions into it, and of course we should lock ext4_li_mtx
3620 	 * to atomically free the list and ext4_li_info, because at
3621 	 * this point another ext4 filesystem could be registering
3622 	 * new one.
3623 	 */
3624 	mutex_lock(&ext4_li_mtx);
3625 	mutex_lock(&eli->li_list_mtx);
3626 	if (!list_empty(&eli->li_request_list)) {
3627 		mutex_unlock(&eli->li_list_mtx);
3628 		mutex_unlock(&ext4_li_mtx);
3629 		goto cont_thread;
3630 	}
3631 	mutex_unlock(&eli->li_list_mtx);
3632 	kfree(ext4_li_info);
3633 	ext4_li_info = NULL;
3634 	mutex_unlock(&ext4_li_mtx);
3635 
3636 	return 0;
3637 }
3638 
3639 static void ext4_clear_request_list(void)
3640 {
3641 	struct list_head *pos, *n;
3642 	struct ext4_li_request *elr;
3643 
3644 	mutex_lock(&ext4_li_info->li_list_mtx);
3645 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3646 		elr = list_entry(pos, struct ext4_li_request,
3647 				 lr_request);
3648 		ext4_remove_li_request(elr);
3649 	}
3650 	mutex_unlock(&ext4_li_info->li_list_mtx);
3651 }
3652 
3653 static int ext4_run_lazyinit_thread(void)
3654 {
3655 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3656 					 ext4_li_info, "ext4lazyinit");
3657 	if (IS_ERR(ext4_lazyinit_task)) {
3658 		int err = PTR_ERR(ext4_lazyinit_task);
3659 		ext4_clear_request_list();
3660 		kfree(ext4_li_info);
3661 		ext4_li_info = NULL;
3662 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3663 				 "initialization thread\n",
3664 				 err);
3665 		return err;
3666 	}
3667 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3668 	return 0;
3669 }
3670 
3671 /*
3672  * Check whether it make sense to run itable init. thread or not.
3673  * If there is at least one uninitialized inode table, return
3674  * corresponding group number, else the loop goes through all
3675  * groups and return total number of groups.
3676  */
3677 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3678 {
3679 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3680 	struct ext4_group_desc *gdp = NULL;
3681 
3682 	if (!ext4_has_group_desc_csum(sb))
3683 		return ngroups;
3684 
3685 	for (group = 0; group < ngroups; group++) {
3686 		gdp = ext4_get_group_desc(sb, group, NULL);
3687 		if (!gdp)
3688 			continue;
3689 
3690 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3691 			break;
3692 	}
3693 
3694 	return group;
3695 }
3696 
3697 static int ext4_li_info_new(void)
3698 {
3699 	struct ext4_lazy_init *eli = NULL;
3700 
3701 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3702 	if (!eli)
3703 		return -ENOMEM;
3704 
3705 	INIT_LIST_HEAD(&eli->li_request_list);
3706 	mutex_init(&eli->li_list_mtx);
3707 
3708 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3709 
3710 	ext4_li_info = eli;
3711 
3712 	return 0;
3713 }
3714 
3715 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3716 					    ext4_group_t start)
3717 {
3718 	struct ext4_li_request *elr;
3719 
3720 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3721 	if (!elr)
3722 		return NULL;
3723 
3724 	elr->lr_super = sb;
3725 	elr->lr_first_not_zeroed = start;
3726 	if (test_opt(sb, PREFETCH_BLOCK_BITMAPS))
3727 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3728 	else {
3729 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3730 		elr->lr_next_group = start;
3731 	}
3732 
3733 	/*
3734 	 * Randomize first schedule time of the request to
3735 	 * spread the inode table initialization requests
3736 	 * better.
3737 	 */
3738 	elr->lr_next_sched = jiffies + (prandom_u32() %
3739 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3740 	return elr;
3741 }
3742 
3743 int ext4_register_li_request(struct super_block *sb,
3744 			     ext4_group_t first_not_zeroed)
3745 {
3746 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3747 	struct ext4_li_request *elr = NULL;
3748 	ext4_group_t ngroups = sbi->s_groups_count;
3749 	int ret = 0;
3750 
3751 	mutex_lock(&ext4_li_mtx);
3752 	if (sbi->s_li_request != NULL) {
3753 		/*
3754 		 * Reset timeout so it can be computed again, because
3755 		 * s_li_wait_mult might have changed.
3756 		 */
3757 		sbi->s_li_request->lr_timeout = 0;
3758 		goto out;
3759 	}
3760 
3761 	if (!test_opt(sb, PREFETCH_BLOCK_BITMAPS) &&
3762 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3763 	     !test_opt(sb, INIT_INODE_TABLE)))
3764 		goto out;
3765 
3766 	elr = ext4_li_request_new(sb, first_not_zeroed);
3767 	if (!elr) {
3768 		ret = -ENOMEM;
3769 		goto out;
3770 	}
3771 
3772 	if (NULL == ext4_li_info) {
3773 		ret = ext4_li_info_new();
3774 		if (ret)
3775 			goto out;
3776 	}
3777 
3778 	mutex_lock(&ext4_li_info->li_list_mtx);
3779 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3780 	mutex_unlock(&ext4_li_info->li_list_mtx);
3781 
3782 	sbi->s_li_request = elr;
3783 	/*
3784 	 * set elr to NULL here since it has been inserted to
3785 	 * the request_list and the removal and free of it is
3786 	 * handled by ext4_clear_request_list from now on.
3787 	 */
3788 	elr = NULL;
3789 
3790 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3791 		ret = ext4_run_lazyinit_thread();
3792 		if (ret)
3793 			goto out;
3794 	}
3795 out:
3796 	mutex_unlock(&ext4_li_mtx);
3797 	if (ret)
3798 		kfree(elr);
3799 	return ret;
3800 }
3801 
3802 /*
3803  * We do not need to lock anything since this is called on
3804  * module unload.
3805  */
3806 static void ext4_destroy_lazyinit_thread(void)
3807 {
3808 	/*
3809 	 * If thread exited earlier
3810 	 * there's nothing to be done.
3811 	 */
3812 	if (!ext4_li_info || !ext4_lazyinit_task)
3813 		return;
3814 
3815 	kthread_stop(ext4_lazyinit_task);
3816 }
3817 
3818 static int set_journal_csum_feature_set(struct super_block *sb)
3819 {
3820 	int ret = 1;
3821 	int compat, incompat;
3822 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3823 
3824 	if (ext4_has_metadata_csum(sb)) {
3825 		/* journal checksum v3 */
3826 		compat = 0;
3827 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3828 	} else {
3829 		/* journal checksum v1 */
3830 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3831 		incompat = 0;
3832 	}
3833 
3834 	jbd2_journal_clear_features(sbi->s_journal,
3835 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3836 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3837 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3838 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3839 		ret = jbd2_journal_set_features(sbi->s_journal,
3840 				compat, 0,
3841 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3842 				incompat);
3843 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3844 		ret = jbd2_journal_set_features(sbi->s_journal,
3845 				compat, 0,
3846 				incompat);
3847 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3848 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3849 	} else {
3850 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3851 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3852 	}
3853 
3854 	return ret;
3855 }
3856 
3857 /*
3858  * Note: calculating the overhead so we can be compatible with
3859  * historical BSD practice is quite difficult in the face of
3860  * clusters/bigalloc.  This is because multiple metadata blocks from
3861  * different block group can end up in the same allocation cluster.
3862  * Calculating the exact overhead in the face of clustered allocation
3863  * requires either O(all block bitmaps) in memory or O(number of block
3864  * groups**2) in time.  We will still calculate the superblock for
3865  * older file systems --- and if we come across with a bigalloc file
3866  * system with zero in s_overhead_clusters the estimate will be close to
3867  * correct especially for very large cluster sizes --- but for newer
3868  * file systems, it's better to calculate this figure once at mkfs
3869  * time, and store it in the superblock.  If the superblock value is
3870  * present (even for non-bigalloc file systems), we will use it.
3871  */
3872 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3873 			  char *buf)
3874 {
3875 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3876 	struct ext4_group_desc	*gdp;
3877 	ext4_fsblk_t		first_block, last_block, b;
3878 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3879 	int			s, j, count = 0;
3880 
3881 	if (!ext4_has_feature_bigalloc(sb))
3882 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3883 			sbi->s_itb_per_group + 2);
3884 
3885 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3886 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3887 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3888 	for (i = 0; i < ngroups; i++) {
3889 		gdp = ext4_get_group_desc(sb, i, NULL);
3890 		b = ext4_block_bitmap(sb, gdp);
3891 		if (b >= first_block && b <= last_block) {
3892 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3893 			count++;
3894 		}
3895 		b = ext4_inode_bitmap(sb, gdp);
3896 		if (b >= first_block && b <= last_block) {
3897 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3898 			count++;
3899 		}
3900 		b = ext4_inode_table(sb, gdp);
3901 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3902 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3903 				int c = EXT4_B2C(sbi, b - first_block);
3904 				ext4_set_bit(c, buf);
3905 				count++;
3906 			}
3907 		if (i != grp)
3908 			continue;
3909 		s = 0;
3910 		if (ext4_bg_has_super(sb, grp)) {
3911 			ext4_set_bit(s++, buf);
3912 			count++;
3913 		}
3914 		j = ext4_bg_num_gdb(sb, grp);
3915 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3916 			ext4_error(sb, "Invalid number of block group "
3917 				   "descriptor blocks: %d", j);
3918 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3919 		}
3920 		count += j;
3921 		for (; j > 0; j--)
3922 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3923 	}
3924 	if (!count)
3925 		return 0;
3926 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3927 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3928 }
3929 
3930 /*
3931  * Compute the overhead and stash it in sbi->s_overhead
3932  */
3933 int ext4_calculate_overhead(struct super_block *sb)
3934 {
3935 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3936 	struct ext4_super_block *es = sbi->s_es;
3937 	struct inode *j_inode;
3938 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3939 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3940 	ext4_fsblk_t overhead = 0;
3941 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3942 
3943 	if (!buf)
3944 		return -ENOMEM;
3945 
3946 	/*
3947 	 * Compute the overhead (FS structures).  This is constant
3948 	 * for a given filesystem unless the number of block groups
3949 	 * changes so we cache the previous value until it does.
3950 	 */
3951 
3952 	/*
3953 	 * All of the blocks before first_data_block are overhead
3954 	 */
3955 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3956 
3957 	/*
3958 	 * Add the overhead found in each block group
3959 	 */
3960 	for (i = 0; i < ngroups; i++) {
3961 		int blks;
3962 
3963 		blks = count_overhead(sb, i, buf);
3964 		overhead += blks;
3965 		if (blks)
3966 			memset(buf, 0, PAGE_SIZE);
3967 		cond_resched();
3968 	}
3969 
3970 	/*
3971 	 * Add the internal journal blocks whether the journal has been
3972 	 * loaded or not
3973 	 */
3974 	if (sbi->s_journal && !sbi->s_journal_bdev)
3975 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
3976 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3977 		/* j_inum for internal journal is non-zero */
3978 		j_inode = ext4_get_journal_inode(sb, j_inum);
3979 		if (j_inode) {
3980 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3981 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3982 			iput(j_inode);
3983 		} else {
3984 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3985 		}
3986 	}
3987 	sbi->s_overhead = overhead;
3988 	smp_wmb();
3989 	free_page((unsigned long) buf);
3990 	return 0;
3991 }
3992 
3993 static void ext4_set_resv_clusters(struct super_block *sb)
3994 {
3995 	ext4_fsblk_t resv_clusters;
3996 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3997 
3998 	/*
3999 	 * There's no need to reserve anything when we aren't using extents.
4000 	 * The space estimates are exact, there are no unwritten extents,
4001 	 * hole punching doesn't need new metadata... This is needed especially
4002 	 * to keep ext2/3 backward compatibility.
4003 	 */
4004 	if (!ext4_has_feature_extents(sb))
4005 		return;
4006 	/*
4007 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4008 	 * This should cover the situations where we can not afford to run
4009 	 * out of space like for example punch hole, or converting
4010 	 * unwritten extents in delalloc path. In most cases such
4011 	 * allocation would require 1, or 2 blocks, higher numbers are
4012 	 * very rare.
4013 	 */
4014 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4015 			 sbi->s_cluster_bits);
4016 
4017 	do_div(resv_clusters, 50);
4018 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4019 
4020 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4021 }
4022 
4023 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
4024 {
4025 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
4026 	char *orig_data = kstrdup(data, GFP_KERNEL);
4027 	struct buffer_head *bh, **group_desc;
4028 	struct ext4_super_block *es = NULL;
4029 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4030 	struct flex_groups **flex_groups;
4031 	ext4_fsblk_t block;
4032 	ext4_fsblk_t sb_block = get_sb_block(&data);
4033 	ext4_fsblk_t logical_sb_block;
4034 	unsigned long offset = 0;
4035 	unsigned long journal_devnum = 0;
4036 	unsigned long def_mount_opts;
4037 	struct inode *root;
4038 	const char *descr;
4039 	int ret = -ENOMEM;
4040 	int blocksize, clustersize;
4041 	unsigned int db_count;
4042 	unsigned int i;
4043 	int needs_recovery, has_huge_files;
4044 	__u64 blocks_count;
4045 	int err = 0;
4046 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4047 	ext4_group_t first_not_zeroed;
4048 
4049 	if ((data && !orig_data) || !sbi)
4050 		goto out_free_base;
4051 
4052 	sbi->s_daxdev = dax_dev;
4053 	sbi->s_blockgroup_lock =
4054 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4055 	if (!sbi->s_blockgroup_lock)
4056 		goto out_free_base;
4057 
4058 	sb->s_fs_info = sbi;
4059 	sbi->s_sb = sb;
4060 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4061 	sbi->s_sb_block = sb_block;
4062 	if (sb->s_bdev->bd_part)
4063 		sbi->s_sectors_written_start =
4064 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
4065 
4066 	/* Cleanup superblock name */
4067 	strreplace(sb->s_id, '/', '!');
4068 
4069 	/* -EINVAL is default */
4070 	ret = -EINVAL;
4071 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4072 	if (!blocksize) {
4073 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4074 		goto out_fail;
4075 	}
4076 
4077 	/*
4078 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4079 	 * block sizes.  We need to calculate the offset from buffer start.
4080 	 */
4081 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4082 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4083 		offset = do_div(logical_sb_block, blocksize);
4084 	} else {
4085 		logical_sb_block = sb_block;
4086 	}
4087 
4088 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4089 	if (IS_ERR(bh)) {
4090 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4091 		ret = PTR_ERR(bh);
4092 		bh = NULL;
4093 		goto out_fail;
4094 	}
4095 	/*
4096 	 * Note: s_es must be initialized as soon as possible because
4097 	 *       some ext4 macro-instructions depend on its value
4098 	 */
4099 	es = (struct ext4_super_block *) (bh->b_data + offset);
4100 	sbi->s_es = es;
4101 	sb->s_magic = le16_to_cpu(es->s_magic);
4102 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4103 		goto cantfind_ext4;
4104 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4105 
4106 	/* Warn if metadata_csum and gdt_csum are both set. */
4107 	if (ext4_has_feature_metadata_csum(sb) &&
4108 	    ext4_has_feature_gdt_csum(sb))
4109 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4110 			     "redundant flags; please run fsck.");
4111 
4112 	/* Check for a known checksum algorithm */
4113 	if (!ext4_verify_csum_type(sb, es)) {
4114 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4115 			 "unknown checksum algorithm.");
4116 		silent = 1;
4117 		goto cantfind_ext4;
4118 	}
4119 
4120 	/* Load the checksum driver */
4121 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4122 	if (IS_ERR(sbi->s_chksum_driver)) {
4123 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4124 		ret = PTR_ERR(sbi->s_chksum_driver);
4125 		sbi->s_chksum_driver = NULL;
4126 		goto failed_mount;
4127 	}
4128 
4129 	/* Check superblock checksum */
4130 	if (!ext4_superblock_csum_verify(sb, es)) {
4131 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4132 			 "invalid superblock checksum.  Run e2fsck?");
4133 		silent = 1;
4134 		ret = -EFSBADCRC;
4135 		goto cantfind_ext4;
4136 	}
4137 
4138 	/* Precompute checksum seed for all metadata */
4139 	if (ext4_has_feature_csum_seed(sb))
4140 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4141 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4142 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4143 					       sizeof(es->s_uuid));
4144 
4145 	/* Set defaults before we parse the mount options */
4146 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4147 	set_opt(sb, INIT_INODE_TABLE);
4148 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4149 		set_opt(sb, DEBUG);
4150 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4151 		set_opt(sb, GRPID);
4152 	if (def_mount_opts & EXT4_DEFM_UID16)
4153 		set_opt(sb, NO_UID32);
4154 	/* xattr user namespace & acls are now defaulted on */
4155 	set_opt(sb, XATTR_USER);
4156 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4157 	set_opt(sb, POSIX_ACL);
4158 #endif
4159 	if (ext4_has_feature_fast_commit(sb))
4160 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4161 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4162 	if (ext4_has_metadata_csum(sb))
4163 		set_opt(sb, JOURNAL_CHECKSUM);
4164 
4165 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4166 		set_opt(sb, JOURNAL_DATA);
4167 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4168 		set_opt(sb, ORDERED_DATA);
4169 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4170 		set_opt(sb, WRITEBACK_DATA);
4171 
4172 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4173 		set_opt(sb, ERRORS_PANIC);
4174 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4175 		set_opt(sb, ERRORS_CONT);
4176 	else
4177 		set_opt(sb, ERRORS_RO);
4178 	/* block_validity enabled by default; disable with noblock_validity */
4179 	set_opt(sb, BLOCK_VALIDITY);
4180 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4181 		set_opt(sb, DISCARD);
4182 
4183 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4184 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4185 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4186 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4187 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4188 
4189 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4190 		set_opt(sb, BARRIER);
4191 
4192 	/*
4193 	 * enable delayed allocation by default
4194 	 * Use -o nodelalloc to turn it off
4195 	 */
4196 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4197 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4198 		set_opt(sb, DELALLOC);
4199 
4200 	/*
4201 	 * set default s_li_wait_mult for lazyinit, for the case there is
4202 	 * no mount option specified.
4203 	 */
4204 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4205 
4206 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4207 
4208 	if (blocksize == PAGE_SIZE)
4209 		set_opt(sb, DIOREAD_NOLOCK);
4210 
4211 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
4212 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
4213 		ext4_msg(sb, KERN_ERR,
4214 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
4215 			 blocksize, le32_to_cpu(es->s_log_block_size));
4216 		goto failed_mount;
4217 	}
4218 
4219 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4220 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4221 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4222 	} else {
4223 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4224 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4225 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4226 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4227 				 sbi->s_first_ino);
4228 			goto failed_mount;
4229 		}
4230 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4231 		    (!is_power_of_2(sbi->s_inode_size)) ||
4232 		    (sbi->s_inode_size > blocksize)) {
4233 			ext4_msg(sb, KERN_ERR,
4234 			       "unsupported inode size: %d",
4235 			       sbi->s_inode_size);
4236 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4237 			goto failed_mount;
4238 		}
4239 		/*
4240 		 * i_atime_extra is the last extra field available for
4241 		 * [acm]times in struct ext4_inode. Checking for that
4242 		 * field should suffice to ensure we have extra space
4243 		 * for all three.
4244 		 */
4245 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4246 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4247 			sb->s_time_gran = 1;
4248 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4249 		} else {
4250 			sb->s_time_gran = NSEC_PER_SEC;
4251 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4252 		}
4253 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4254 	}
4255 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4256 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4257 			EXT4_GOOD_OLD_INODE_SIZE;
4258 		if (ext4_has_feature_extra_isize(sb)) {
4259 			unsigned v, max = (sbi->s_inode_size -
4260 					   EXT4_GOOD_OLD_INODE_SIZE);
4261 
4262 			v = le16_to_cpu(es->s_want_extra_isize);
4263 			if (v > max) {
4264 				ext4_msg(sb, KERN_ERR,
4265 					 "bad s_want_extra_isize: %d", v);
4266 				goto failed_mount;
4267 			}
4268 			if (sbi->s_want_extra_isize < v)
4269 				sbi->s_want_extra_isize = v;
4270 
4271 			v = le16_to_cpu(es->s_min_extra_isize);
4272 			if (v > max) {
4273 				ext4_msg(sb, KERN_ERR,
4274 					 "bad s_min_extra_isize: %d", v);
4275 				goto failed_mount;
4276 			}
4277 			if (sbi->s_want_extra_isize < v)
4278 				sbi->s_want_extra_isize = v;
4279 		}
4280 	}
4281 
4282 	if (sbi->s_es->s_mount_opts[0]) {
4283 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4284 					      sizeof(sbi->s_es->s_mount_opts),
4285 					      GFP_KERNEL);
4286 		if (!s_mount_opts)
4287 			goto failed_mount;
4288 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
4289 				   &journal_ioprio, 0)) {
4290 			ext4_msg(sb, KERN_WARNING,
4291 				 "failed to parse options in superblock: %s",
4292 				 s_mount_opts);
4293 		}
4294 		kfree(s_mount_opts);
4295 	}
4296 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4297 	if (!parse_options((char *) data, sb, &journal_devnum,
4298 			   &journal_ioprio, 0))
4299 		goto failed_mount;
4300 
4301 #ifdef CONFIG_UNICODE
4302 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4303 		const struct ext4_sb_encodings *encoding_info;
4304 		struct unicode_map *encoding;
4305 		__u16 encoding_flags;
4306 
4307 		if (ext4_has_feature_encrypt(sb)) {
4308 			ext4_msg(sb, KERN_ERR,
4309 				 "Can't mount with encoding and encryption");
4310 			goto failed_mount;
4311 		}
4312 
4313 		if (ext4_sb_read_encoding(es, &encoding_info,
4314 					  &encoding_flags)) {
4315 			ext4_msg(sb, KERN_ERR,
4316 				 "Encoding requested by superblock is unknown");
4317 			goto failed_mount;
4318 		}
4319 
4320 		encoding = utf8_load(encoding_info->version);
4321 		if (IS_ERR(encoding)) {
4322 			ext4_msg(sb, KERN_ERR,
4323 				 "can't mount with superblock charset: %s-%s "
4324 				 "not supported by the kernel. flags: 0x%x.",
4325 				 encoding_info->name, encoding_info->version,
4326 				 encoding_flags);
4327 			goto failed_mount;
4328 		}
4329 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4330 			 "%s-%s with flags 0x%hx", encoding_info->name,
4331 			 encoding_info->version?:"\b", encoding_flags);
4332 
4333 		sb->s_encoding = encoding;
4334 		sb->s_encoding_flags = encoding_flags;
4335 	}
4336 #endif
4337 
4338 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4339 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4340 		/* can't mount with both data=journal and dioread_nolock. */
4341 		clear_opt(sb, DIOREAD_NOLOCK);
4342 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4343 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4344 			ext4_msg(sb, KERN_ERR, "can't mount with "
4345 				 "both data=journal and delalloc");
4346 			goto failed_mount;
4347 		}
4348 		if (test_opt(sb, DAX_ALWAYS)) {
4349 			ext4_msg(sb, KERN_ERR, "can't mount with "
4350 				 "both data=journal and dax");
4351 			goto failed_mount;
4352 		}
4353 		if (ext4_has_feature_encrypt(sb)) {
4354 			ext4_msg(sb, KERN_WARNING,
4355 				 "encrypted files will use data=ordered "
4356 				 "instead of data journaling mode");
4357 		}
4358 		if (test_opt(sb, DELALLOC))
4359 			clear_opt(sb, DELALLOC);
4360 	} else {
4361 		sb->s_iflags |= SB_I_CGROUPWB;
4362 	}
4363 
4364 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4365 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4366 
4367 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4368 	    (ext4_has_compat_features(sb) ||
4369 	     ext4_has_ro_compat_features(sb) ||
4370 	     ext4_has_incompat_features(sb)))
4371 		ext4_msg(sb, KERN_WARNING,
4372 		       "feature flags set on rev 0 fs, "
4373 		       "running e2fsck is recommended");
4374 
4375 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4376 		set_opt2(sb, HURD_COMPAT);
4377 		if (ext4_has_feature_64bit(sb)) {
4378 			ext4_msg(sb, KERN_ERR,
4379 				 "The Hurd can't support 64-bit file systems");
4380 			goto failed_mount;
4381 		}
4382 
4383 		/*
4384 		 * ea_inode feature uses l_i_version field which is not
4385 		 * available in HURD_COMPAT mode.
4386 		 */
4387 		if (ext4_has_feature_ea_inode(sb)) {
4388 			ext4_msg(sb, KERN_ERR,
4389 				 "ea_inode feature is not supported for Hurd");
4390 			goto failed_mount;
4391 		}
4392 	}
4393 
4394 	if (IS_EXT2_SB(sb)) {
4395 		if (ext2_feature_set_ok(sb))
4396 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4397 				 "using the ext4 subsystem");
4398 		else {
4399 			/*
4400 			 * If we're probing be silent, if this looks like
4401 			 * it's actually an ext[34] filesystem.
4402 			 */
4403 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4404 				goto failed_mount;
4405 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4406 				 "to feature incompatibilities");
4407 			goto failed_mount;
4408 		}
4409 	}
4410 
4411 	if (IS_EXT3_SB(sb)) {
4412 		if (ext3_feature_set_ok(sb))
4413 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4414 				 "using the ext4 subsystem");
4415 		else {
4416 			/*
4417 			 * If we're probing be silent, if this looks like
4418 			 * it's actually an ext4 filesystem.
4419 			 */
4420 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4421 				goto failed_mount;
4422 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4423 				 "to feature incompatibilities");
4424 			goto failed_mount;
4425 		}
4426 	}
4427 
4428 	/*
4429 	 * Check feature flags regardless of the revision level, since we
4430 	 * previously didn't change the revision level when setting the flags,
4431 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4432 	 */
4433 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4434 		goto failed_mount;
4435 
4436 	if (le32_to_cpu(es->s_log_block_size) >
4437 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4438 		ext4_msg(sb, KERN_ERR,
4439 			 "Invalid log block size: %u",
4440 			 le32_to_cpu(es->s_log_block_size));
4441 		goto failed_mount;
4442 	}
4443 	if (le32_to_cpu(es->s_log_cluster_size) >
4444 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4445 		ext4_msg(sb, KERN_ERR,
4446 			 "Invalid log cluster size: %u",
4447 			 le32_to_cpu(es->s_log_cluster_size));
4448 		goto failed_mount;
4449 	}
4450 
4451 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4452 		ext4_msg(sb, KERN_ERR,
4453 			 "Number of reserved GDT blocks insanely large: %d",
4454 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4455 		goto failed_mount;
4456 	}
4457 
4458 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4459 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4460 
4461 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4462 		if (ext4_has_feature_inline_data(sb)) {
4463 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4464 					" that may contain inline data");
4465 			goto failed_mount;
4466 		}
4467 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4468 			ext4_msg(sb, KERN_ERR,
4469 				"DAX unsupported by block device.");
4470 			goto failed_mount;
4471 		}
4472 	}
4473 
4474 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4475 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4476 			 es->s_encryption_level);
4477 		goto failed_mount;
4478 	}
4479 
4480 	if (sb->s_blocksize != blocksize) {
4481 		/* Validate the filesystem blocksize */
4482 		if (!sb_set_blocksize(sb, blocksize)) {
4483 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4484 					blocksize);
4485 			goto failed_mount;
4486 		}
4487 
4488 		brelse(bh);
4489 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4490 		offset = do_div(logical_sb_block, blocksize);
4491 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4492 		if (IS_ERR(bh)) {
4493 			ext4_msg(sb, KERN_ERR,
4494 			       "Can't read superblock on 2nd try");
4495 			ret = PTR_ERR(bh);
4496 			bh = NULL;
4497 			goto failed_mount;
4498 		}
4499 		es = (struct ext4_super_block *)(bh->b_data + offset);
4500 		sbi->s_es = es;
4501 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4502 			ext4_msg(sb, KERN_ERR,
4503 			       "Magic mismatch, very weird!");
4504 			goto failed_mount;
4505 		}
4506 	}
4507 
4508 	has_huge_files = ext4_has_feature_huge_file(sb);
4509 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4510 						      has_huge_files);
4511 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4512 
4513 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4514 	if (ext4_has_feature_64bit(sb)) {
4515 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4516 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4517 		    !is_power_of_2(sbi->s_desc_size)) {
4518 			ext4_msg(sb, KERN_ERR,
4519 			       "unsupported descriptor size %lu",
4520 			       sbi->s_desc_size);
4521 			goto failed_mount;
4522 		}
4523 	} else
4524 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4525 
4526 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4527 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4528 
4529 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4530 	if (sbi->s_inodes_per_block == 0)
4531 		goto cantfind_ext4;
4532 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4533 	    sbi->s_inodes_per_group > blocksize * 8) {
4534 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4535 			 sbi->s_inodes_per_group);
4536 		goto failed_mount;
4537 	}
4538 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4539 					sbi->s_inodes_per_block;
4540 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4541 	sbi->s_sbh = bh;
4542 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4543 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4544 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4545 
4546 	for (i = 0; i < 4; i++)
4547 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4548 	sbi->s_def_hash_version = es->s_def_hash_version;
4549 	if (ext4_has_feature_dir_index(sb)) {
4550 		i = le32_to_cpu(es->s_flags);
4551 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4552 			sbi->s_hash_unsigned = 3;
4553 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4554 #ifdef __CHAR_UNSIGNED__
4555 			if (!sb_rdonly(sb))
4556 				es->s_flags |=
4557 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4558 			sbi->s_hash_unsigned = 3;
4559 #else
4560 			if (!sb_rdonly(sb))
4561 				es->s_flags |=
4562 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4563 #endif
4564 		}
4565 	}
4566 
4567 	/* Handle clustersize */
4568 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4569 	if (ext4_has_feature_bigalloc(sb)) {
4570 		if (clustersize < blocksize) {
4571 			ext4_msg(sb, KERN_ERR,
4572 				 "cluster size (%d) smaller than "
4573 				 "block size (%d)", clustersize, blocksize);
4574 			goto failed_mount;
4575 		}
4576 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4577 			le32_to_cpu(es->s_log_block_size);
4578 		sbi->s_clusters_per_group =
4579 			le32_to_cpu(es->s_clusters_per_group);
4580 		if (sbi->s_clusters_per_group > blocksize * 8) {
4581 			ext4_msg(sb, KERN_ERR,
4582 				 "#clusters per group too big: %lu",
4583 				 sbi->s_clusters_per_group);
4584 			goto failed_mount;
4585 		}
4586 		if (sbi->s_blocks_per_group !=
4587 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4588 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4589 				 "clusters per group (%lu) inconsistent",
4590 				 sbi->s_blocks_per_group,
4591 				 sbi->s_clusters_per_group);
4592 			goto failed_mount;
4593 		}
4594 	} else {
4595 		if (clustersize != blocksize) {
4596 			ext4_msg(sb, KERN_ERR,
4597 				 "fragment/cluster size (%d) != "
4598 				 "block size (%d)", clustersize, blocksize);
4599 			goto failed_mount;
4600 		}
4601 		if (sbi->s_blocks_per_group > blocksize * 8) {
4602 			ext4_msg(sb, KERN_ERR,
4603 				 "#blocks per group too big: %lu",
4604 				 sbi->s_blocks_per_group);
4605 			goto failed_mount;
4606 		}
4607 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4608 		sbi->s_cluster_bits = 0;
4609 	}
4610 	sbi->s_cluster_ratio = clustersize / blocksize;
4611 
4612 	/* Do we have standard group size of clustersize * 8 blocks ? */
4613 	if (sbi->s_blocks_per_group == clustersize << 3)
4614 		set_opt2(sb, STD_GROUP_SIZE);
4615 
4616 	/*
4617 	 * Test whether we have more sectors than will fit in sector_t,
4618 	 * and whether the max offset is addressable by the page cache.
4619 	 */
4620 	err = generic_check_addressable(sb->s_blocksize_bits,
4621 					ext4_blocks_count(es));
4622 	if (err) {
4623 		ext4_msg(sb, KERN_ERR, "filesystem"
4624 			 " too large to mount safely on this system");
4625 		goto failed_mount;
4626 	}
4627 
4628 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4629 		goto cantfind_ext4;
4630 
4631 	/* check blocks count against device size */
4632 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4633 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4634 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4635 		       "exceeds size of device (%llu blocks)",
4636 		       ext4_blocks_count(es), blocks_count);
4637 		goto failed_mount;
4638 	}
4639 
4640 	/*
4641 	 * It makes no sense for the first data block to be beyond the end
4642 	 * of the filesystem.
4643 	 */
4644 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4645 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4646 			 "block %u is beyond end of filesystem (%llu)",
4647 			 le32_to_cpu(es->s_first_data_block),
4648 			 ext4_blocks_count(es));
4649 		goto failed_mount;
4650 	}
4651 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4652 	    (sbi->s_cluster_ratio == 1)) {
4653 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4654 			 "block is 0 with a 1k block and cluster size");
4655 		goto failed_mount;
4656 	}
4657 
4658 	blocks_count = (ext4_blocks_count(es) -
4659 			le32_to_cpu(es->s_first_data_block) +
4660 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4661 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4662 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4663 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4664 		       "(block count %llu, first data block %u, "
4665 		       "blocks per group %lu)", blocks_count,
4666 		       ext4_blocks_count(es),
4667 		       le32_to_cpu(es->s_first_data_block),
4668 		       EXT4_BLOCKS_PER_GROUP(sb));
4669 		goto failed_mount;
4670 	}
4671 	sbi->s_groups_count = blocks_count;
4672 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4673 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4674 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4675 	    le32_to_cpu(es->s_inodes_count)) {
4676 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4677 			 le32_to_cpu(es->s_inodes_count),
4678 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4679 		ret = -EINVAL;
4680 		goto failed_mount;
4681 	}
4682 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4683 		   EXT4_DESC_PER_BLOCK(sb);
4684 	if (ext4_has_feature_meta_bg(sb)) {
4685 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4686 			ext4_msg(sb, KERN_WARNING,
4687 				 "first meta block group too large: %u "
4688 				 "(group descriptor block count %u)",
4689 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4690 			goto failed_mount;
4691 		}
4692 	}
4693 	rcu_assign_pointer(sbi->s_group_desc,
4694 			   kvmalloc_array(db_count,
4695 					  sizeof(struct buffer_head *),
4696 					  GFP_KERNEL));
4697 	if (sbi->s_group_desc == NULL) {
4698 		ext4_msg(sb, KERN_ERR, "not enough memory");
4699 		ret = -ENOMEM;
4700 		goto failed_mount;
4701 	}
4702 
4703 	bgl_lock_init(sbi->s_blockgroup_lock);
4704 
4705 	/* Pre-read the descriptors into the buffer cache */
4706 	for (i = 0; i < db_count; i++) {
4707 		block = descriptor_loc(sb, logical_sb_block, i);
4708 		ext4_sb_breadahead_unmovable(sb, block);
4709 	}
4710 
4711 	for (i = 0; i < db_count; i++) {
4712 		struct buffer_head *bh;
4713 
4714 		block = descriptor_loc(sb, logical_sb_block, i);
4715 		bh = ext4_sb_bread_unmovable(sb, block);
4716 		if (IS_ERR(bh)) {
4717 			ext4_msg(sb, KERN_ERR,
4718 			       "can't read group descriptor %d", i);
4719 			db_count = i;
4720 			ret = PTR_ERR(bh);
4721 			bh = NULL;
4722 			goto failed_mount2;
4723 		}
4724 		rcu_read_lock();
4725 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4726 		rcu_read_unlock();
4727 	}
4728 	sbi->s_gdb_count = db_count;
4729 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4730 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4731 		ret = -EFSCORRUPTED;
4732 		goto failed_mount2;
4733 	}
4734 
4735 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4736 
4737 	/* Register extent status tree shrinker */
4738 	if (ext4_es_register_shrinker(sbi))
4739 		goto failed_mount3;
4740 
4741 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4742 	sbi->s_extent_max_zeroout_kb = 32;
4743 
4744 	/*
4745 	 * set up enough so that it can read an inode
4746 	 */
4747 	sb->s_op = &ext4_sops;
4748 	sb->s_export_op = &ext4_export_ops;
4749 	sb->s_xattr = ext4_xattr_handlers;
4750 #ifdef CONFIG_FS_ENCRYPTION
4751 	sb->s_cop = &ext4_cryptops;
4752 #endif
4753 #ifdef CONFIG_FS_VERITY
4754 	sb->s_vop = &ext4_verityops;
4755 #endif
4756 #ifdef CONFIG_QUOTA
4757 	sb->dq_op = &ext4_quota_operations;
4758 	if (ext4_has_feature_quota(sb))
4759 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4760 	else
4761 		sb->s_qcop = &ext4_qctl_operations;
4762 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4763 #endif
4764 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4765 
4766 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4767 	mutex_init(&sbi->s_orphan_lock);
4768 
4769 	/* Initialize fast commit stuff */
4770 	atomic_set(&sbi->s_fc_subtid, 0);
4771 	atomic_set(&sbi->s_fc_ineligible_updates, 0);
4772 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4773 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4774 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4775 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4776 	sbi->s_fc_bytes = 0;
4777 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4778 	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
4779 	spin_lock_init(&sbi->s_fc_lock);
4780 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4781 	sbi->s_fc_replay_state.fc_regions = NULL;
4782 	sbi->s_fc_replay_state.fc_regions_size = 0;
4783 	sbi->s_fc_replay_state.fc_regions_used = 0;
4784 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4785 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4786 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4787 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4788 
4789 	sb->s_root = NULL;
4790 
4791 	needs_recovery = (es->s_last_orphan != 0 ||
4792 			  ext4_has_feature_journal_needs_recovery(sb));
4793 
4794 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4795 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4796 			goto failed_mount3a;
4797 
4798 	/*
4799 	 * The first inode we look at is the journal inode.  Don't try
4800 	 * root first: it may be modified in the journal!
4801 	 */
4802 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4803 		err = ext4_load_journal(sb, es, journal_devnum);
4804 		if (err)
4805 			goto failed_mount3a;
4806 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4807 		   ext4_has_feature_journal_needs_recovery(sb)) {
4808 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4809 		       "suppressed and not mounted read-only");
4810 		goto failed_mount_wq;
4811 	} else {
4812 		/* Nojournal mode, all journal mount options are illegal */
4813 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4814 			ext4_msg(sb, KERN_ERR, "can't mount with "
4815 				 "journal_checksum, fs mounted w/o journal");
4816 			goto failed_mount_wq;
4817 		}
4818 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4819 			ext4_msg(sb, KERN_ERR, "can't mount with "
4820 				 "journal_async_commit, fs mounted w/o journal");
4821 			goto failed_mount_wq;
4822 		}
4823 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4824 			ext4_msg(sb, KERN_ERR, "can't mount with "
4825 				 "commit=%lu, fs mounted w/o journal",
4826 				 sbi->s_commit_interval / HZ);
4827 			goto failed_mount_wq;
4828 		}
4829 		if (EXT4_MOUNT_DATA_FLAGS &
4830 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4831 			ext4_msg(sb, KERN_ERR, "can't mount with "
4832 				 "data=, fs mounted w/o journal");
4833 			goto failed_mount_wq;
4834 		}
4835 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4836 		clear_opt(sb, JOURNAL_CHECKSUM);
4837 		clear_opt(sb, DATA_FLAGS);
4838 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4839 		sbi->s_journal = NULL;
4840 		needs_recovery = 0;
4841 		goto no_journal;
4842 	}
4843 
4844 	if (ext4_has_feature_64bit(sb) &&
4845 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4846 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4847 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4848 		goto failed_mount_wq;
4849 	}
4850 
4851 	if (!set_journal_csum_feature_set(sb)) {
4852 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4853 			 "feature set");
4854 		goto failed_mount_wq;
4855 	}
4856 
4857 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4858 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4859 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4860 		ext4_msg(sb, KERN_ERR,
4861 			"Failed to set fast commit journal feature");
4862 		goto failed_mount_wq;
4863 	}
4864 
4865 	/* We have now updated the journal if required, so we can
4866 	 * validate the data journaling mode. */
4867 	switch (test_opt(sb, DATA_FLAGS)) {
4868 	case 0:
4869 		/* No mode set, assume a default based on the journal
4870 		 * capabilities: ORDERED_DATA if the journal can
4871 		 * cope, else JOURNAL_DATA
4872 		 */
4873 		if (jbd2_journal_check_available_features
4874 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4875 			set_opt(sb, ORDERED_DATA);
4876 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4877 		} else {
4878 			set_opt(sb, JOURNAL_DATA);
4879 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4880 		}
4881 		break;
4882 
4883 	case EXT4_MOUNT_ORDERED_DATA:
4884 	case EXT4_MOUNT_WRITEBACK_DATA:
4885 		if (!jbd2_journal_check_available_features
4886 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4887 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4888 			       "requested data journaling mode");
4889 			goto failed_mount_wq;
4890 		}
4891 	default:
4892 		break;
4893 	}
4894 
4895 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4896 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4897 		ext4_msg(sb, KERN_ERR, "can't mount with "
4898 			"journal_async_commit in data=ordered mode");
4899 		goto failed_mount_wq;
4900 	}
4901 
4902 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4903 
4904 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4905 	sbi->s_journal->j_submit_inode_data_buffers =
4906 		ext4_journal_submit_inode_data_buffers;
4907 	sbi->s_journal->j_finish_inode_data_buffers =
4908 		ext4_journal_finish_inode_data_buffers;
4909 
4910 no_journal:
4911 	if (!test_opt(sb, NO_MBCACHE)) {
4912 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4913 		if (!sbi->s_ea_block_cache) {
4914 			ext4_msg(sb, KERN_ERR,
4915 				 "Failed to create ea_block_cache");
4916 			goto failed_mount_wq;
4917 		}
4918 
4919 		if (ext4_has_feature_ea_inode(sb)) {
4920 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4921 			if (!sbi->s_ea_inode_cache) {
4922 				ext4_msg(sb, KERN_ERR,
4923 					 "Failed to create ea_inode_cache");
4924 				goto failed_mount_wq;
4925 			}
4926 		}
4927 	}
4928 
4929 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4930 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4931 		goto failed_mount_wq;
4932 	}
4933 
4934 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4935 	    !ext4_has_feature_encrypt(sb)) {
4936 		ext4_set_feature_encrypt(sb);
4937 		ext4_commit_super(sb, 1);
4938 	}
4939 
4940 	/*
4941 	 * Get the # of file system overhead blocks from the
4942 	 * superblock if present.
4943 	 */
4944 	if (es->s_overhead_clusters)
4945 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4946 	else {
4947 		err = ext4_calculate_overhead(sb);
4948 		if (err)
4949 			goto failed_mount_wq;
4950 	}
4951 
4952 	/*
4953 	 * The maximum number of concurrent works can be high and
4954 	 * concurrency isn't really necessary.  Limit it to 1.
4955 	 */
4956 	EXT4_SB(sb)->rsv_conversion_wq =
4957 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4958 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4959 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4960 		ret = -ENOMEM;
4961 		goto failed_mount4;
4962 	}
4963 
4964 	/*
4965 	 * The jbd2_journal_load will have done any necessary log recovery,
4966 	 * so we can safely mount the rest of the filesystem now.
4967 	 */
4968 
4969 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4970 	if (IS_ERR(root)) {
4971 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4972 		ret = PTR_ERR(root);
4973 		root = NULL;
4974 		goto failed_mount4;
4975 	}
4976 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4977 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4978 		iput(root);
4979 		goto failed_mount4;
4980 	}
4981 
4982 #ifdef CONFIG_UNICODE
4983 	if (sb->s_encoding)
4984 		sb->s_d_op = &ext4_dentry_ops;
4985 #endif
4986 
4987 	sb->s_root = d_make_root(root);
4988 	if (!sb->s_root) {
4989 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4990 		ret = -ENOMEM;
4991 		goto failed_mount4;
4992 	}
4993 
4994 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4995 	if (ret == -EROFS) {
4996 		sb->s_flags |= SB_RDONLY;
4997 		ret = 0;
4998 	} else if (ret)
4999 		goto failed_mount4a;
5000 
5001 	ext4_set_resv_clusters(sb);
5002 
5003 	if (test_opt(sb, BLOCK_VALIDITY)) {
5004 		err = ext4_setup_system_zone(sb);
5005 		if (err) {
5006 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5007 				 "zone (%d)", err);
5008 			goto failed_mount4a;
5009 		}
5010 	}
5011 	ext4_fc_replay_cleanup(sb);
5012 
5013 	ext4_ext_init(sb);
5014 	err = ext4_mb_init(sb);
5015 	if (err) {
5016 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5017 			 err);
5018 		goto failed_mount5;
5019 	}
5020 
5021 	block = ext4_count_free_clusters(sb);
5022 	ext4_free_blocks_count_set(sbi->s_es,
5023 				   EXT4_C2B(sbi, block));
5024 	ext4_superblock_csum_set(sb);
5025 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5026 				  GFP_KERNEL);
5027 	if (!err) {
5028 		unsigned long freei = ext4_count_free_inodes(sb);
5029 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5030 		ext4_superblock_csum_set(sb);
5031 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5032 					  GFP_KERNEL);
5033 	}
5034 	if (!err)
5035 		err = percpu_counter_init(&sbi->s_dirs_counter,
5036 					  ext4_count_dirs(sb), GFP_KERNEL);
5037 	if (!err)
5038 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5039 					  GFP_KERNEL);
5040 	if (!err)
5041 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5042 
5043 	if (err) {
5044 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5045 		goto failed_mount6;
5046 	}
5047 
5048 	if (ext4_has_feature_flex_bg(sb))
5049 		if (!ext4_fill_flex_info(sb)) {
5050 			ext4_msg(sb, KERN_ERR,
5051 			       "unable to initialize "
5052 			       "flex_bg meta info!");
5053 			goto failed_mount6;
5054 		}
5055 
5056 	err = ext4_register_li_request(sb, first_not_zeroed);
5057 	if (err)
5058 		goto failed_mount6;
5059 
5060 	err = ext4_register_sysfs(sb);
5061 	if (err)
5062 		goto failed_mount7;
5063 
5064 #ifdef CONFIG_QUOTA
5065 	/* Enable quota usage during mount. */
5066 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5067 		err = ext4_enable_quotas(sb);
5068 		if (err)
5069 			goto failed_mount8;
5070 	}
5071 #endif  /* CONFIG_QUOTA */
5072 
5073 	/*
5074 	 * Save the original bdev mapping's wb_err value which could be
5075 	 * used to detect the metadata async write error.
5076 	 */
5077 	spin_lock_init(&sbi->s_bdev_wb_lock);
5078 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5079 				 &sbi->s_bdev_wb_err);
5080 	sb->s_bdev->bd_super = sb;
5081 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5082 	ext4_orphan_cleanup(sb, es);
5083 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5084 	if (needs_recovery) {
5085 		ext4_msg(sb, KERN_INFO, "recovery complete");
5086 		err = ext4_mark_recovery_complete(sb, es);
5087 		if (err)
5088 			goto failed_mount8;
5089 	}
5090 	if (EXT4_SB(sb)->s_journal) {
5091 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5092 			descr = " journalled data mode";
5093 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5094 			descr = " ordered data mode";
5095 		else
5096 			descr = " writeback data mode";
5097 	} else
5098 		descr = "out journal";
5099 
5100 	if (test_opt(sb, DISCARD)) {
5101 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5102 		if (!blk_queue_discard(q))
5103 			ext4_msg(sb, KERN_WARNING,
5104 				 "mounting with \"discard\" option, but "
5105 				 "the device does not support discard");
5106 	}
5107 
5108 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5109 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5110 			 "Opts: %.*s%s%s", descr,
5111 			 (int) sizeof(sbi->s_es->s_mount_opts),
5112 			 sbi->s_es->s_mount_opts,
5113 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
5114 
5115 	if (es->s_error_count)
5116 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5117 
5118 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5119 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5120 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5121 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5122 	atomic_set(&sbi->s_warning_count, 0);
5123 	atomic_set(&sbi->s_msg_count, 0);
5124 
5125 	kfree(orig_data);
5126 	return 0;
5127 
5128 cantfind_ext4:
5129 	if (!silent)
5130 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5131 	goto failed_mount;
5132 
5133 failed_mount8:
5134 	ext4_unregister_sysfs(sb);
5135 	kobject_put(&sbi->s_kobj);
5136 failed_mount7:
5137 	ext4_unregister_li_request(sb);
5138 failed_mount6:
5139 	ext4_mb_release(sb);
5140 	rcu_read_lock();
5141 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5142 	if (flex_groups) {
5143 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5144 			kvfree(flex_groups[i]);
5145 		kvfree(flex_groups);
5146 	}
5147 	rcu_read_unlock();
5148 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5149 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5150 	percpu_counter_destroy(&sbi->s_dirs_counter);
5151 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5152 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5153 failed_mount5:
5154 	ext4_ext_release(sb);
5155 	ext4_release_system_zone(sb);
5156 failed_mount4a:
5157 	dput(sb->s_root);
5158 	sb->s_root = NULL;
5159 failed_mount4:
5160 	ext4_msg(sb, KERN_ERR, "mount failed");
5161 	if (EXT4_SB(sb)->rsv_conversion_wq)
5162 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5163 failed_mount_wq:
5164 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5165 	sbi->s_ea_inode_cache = NULL;
5166 
5167 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5168 	sbi->s_ea_block_cache = NULL;
5169 
5170 	if (sbi->s_journal) {
5171 		jbd2_journal_destroy(sbi->s_journal);
5172 		sbi->s_journal = NULL;
5173 	}
5174 failed_mount3a:
5175 	ext4_es_unregister_shrinker(sbi);
5176 failed_mount3:
5177 	del_timer_sync(&sbi->s_err_report);
5178 	if (sbi->s_mmp_tsk)
5179 		kthread_stop(sbi->s_mmp_tsk);
5180 failed_mount2:
5181 	rcu_read_lock();
5182 	group_desc = rcu_dereference(sbi->s_group_desc);
5183 	for (i = 0; i < db_count; i++)
5184 		brelse(group_desc[i]);
5185 	kvfree(group_desc);
5186 	rcu_read_unlock();
5187 failed_mount:
5188 	if (sbi->s_chksum_driver)
5189 		crypto_free_shash(sbi->s_chksum_driver);
5190 
5191 #ifdef CONFIG_UNICODE
5192 	utf8_unload(sb->s_encoding);
5193 #endif
5194 
5195 #ifdef CONFIG_QUOTA
5196 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5197 		kfree(get_qf_name(sb, sbi, i));
5198 #endif
5199 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5200 	ext4_blkdev_remove(sbi);
5201 	brelse(bh);
5202 out_fail:
5203 	sb->s_fs_info = NULL;
5204 	kfree(sbi->s_blockgroup_lock);
5205 out_free_base:
5206 	kfree(sbi);
5207 	kfree(orig_data);
5208 	fs_put_dax(dax_dev);
5209 	return err ? err : ret;
5210 }
5211 
5212 /*
5213  * Setup any per-fs journal parameters now.  We'll do this both on
5214  * initial mount, once the journal has been initialised but before we've
5215  * done any recovery; and again on any subsequent remount.
5216  */
5217 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5218 {
5219 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5220 
5221 	journal->j_commit_interval = sbi->s_commit_interval;
5222 	journal->j_min_batch_time = sbi->s_min_batch_time;
5223 	journal->j_max_batch_time = sbi->s_max_batch_time;
5224 	ext4_fc_init(sb, journal);
5225 
5226 	write_lock(&journal->j_state_lock);
5227 	if (test_opt(sb, BARRIER))
5228 		journal->j_flags |= JBD2_BARRIER;
5229 	else
5230 		journal->j_flags &= ~JBD2_BARRIER;
5231 	if (test_opt(sb, DATA_ERR_ABORT))
5232 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5233 	else
5234 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5235 	write_unlock(&journal->j_state_lock);
5236 }
5237 
5238 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5239 					     unsigned int journal_inum)
5240 {
5241 	struct inode *journal_inode;
5242 
5243 	/*
5244 	 * Test for the existence of a valid inode on disk.  Bad things
5245 	 * happen if we iget() an unused inode, as the subsequent iput()
5246 	 * will try to delete it.
5247 	 */
5248 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5249 	if (IS_ERR(journal_inode)) {
5250 		ext4_msg(sb, KERN_ERR, "no journal found");
5251 		return NULL;
5252 	}
5253 	if (!journal_inode->i_nlink) {
5254 		make_bad_inode(journal_inode);
5255 		iput(journal_inode);
5256 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5257 		return NULL;
5258 	}
5259 
5260 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5261 		  journal_inode, journal_inode->i_size);
5262 	if (!S_ISREG(journal_inode->i_mode)) {
5263 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5264 		iput(journal_inode);
5265 		return NULL;
5266 	}
5267 	return journal_inode;
5268 }
5269 
5270 static journal_t *ext4_get_journal(struct super_block *sb,
5271 				   unsigned int journal_inum)
5272 {
5273 	struct inode *journal_inode;
5274 	journal_t *journal;
5275 
5276 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5277 		return NULL;
5278 
5279 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5280 	if (!journal_inode)
5281 		return NULL;
5282 
5283 	journal = jbd2_journal_init_inode(journal_inode);
5284 	if (!journal) {
5285 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5286 		iput(journal_inode);
5287 		return NULL;
5288 	}
5289 	journal->j_private = sb;
5290 	ext4_init_journal_params(sb, journal);
5291 	return journal;
5292 }
5293 
5294 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5295 				       dev_t j_dev)
5296 {
5297 	struct buffer_head *bh;
5298 	journal_t *journal;
5299 	ext4_fsblk_t start;
5300 	ext4_fsblk_t len;
5301 	int hblock, blocksize;
5302 	ext4_fsblk_t sb_block;
5303 	unsigned long offset;
5304 	struct ext4_super_block *es;
5305 	struct block_device *bdev;
5306 
5307 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5308 		return NULL;
5309 
5310 	bdev = ext4_blkdev_get(j_dev, sb);
5311 	if (bdev == NULL)
5312 		return NULL;
5313 
5314 	blocksize = sb->s_blocksize;
5315 	hblock = bdev_logical_block_size(bdev);
5316 	if (blocksize < hblock) {
5317 		ext4_msg(sb, KERN_ERR,
5318 			"blocksize too small for journal device");
5319 		goto out_bdev;
5320 	}
5321 
5322 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5323 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5324 	set_blocksize(bdev, blocksize);
5325 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5326 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5327 		       "external journal");
5328 		goto out_bdev;
5329 	}
5330 
5331 	es = (struct ext4_super_block *) (bh->b_data + offset);
5332 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5333 	    !(le32_to_cpu(es->s_feature_incompat) &
5334 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5335 		ext4_msg(sb, KERN_ERR, "external journal has "
5336 					"bad superblock");
5337 		brelse(bh);
5338 		goto out_bdev;
5339 	}
5340 
5341 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5342 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5343 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5344 		ext4_msg(sb, KERN_ERR, "external journal has "
5345 				       "corrupt superblock");
5346 		brelse(bh);
5347 		goto out_bdev;
5348 	}
5349 
5350 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5351 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5352 		brelse(bh);
5353 		goto out_bdev;
5354 	}
5355 
5356 	len = ext4_blocks_count(es);
5357 	start = sb_block + 1;
5358 	brelse(bh);	/* we're done with the superblock */
5359 
5360 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5361 					start, len, blocksize);
5362 	if (!journal) {
5363 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5364 		goto out_bdev;
5365 	}
5366 	journal->j_private = sb;
5367 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5368 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5369 		goto out_journal;
5370 	}
5371 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5372 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5373 					"user (unsupported) - %d",
5374 			be32_to_cpu(journal->j_superblock->s_nr_users));
5375 		goto out_journal;
5376 	}
5377 	EXT4_SB(sb)->s_journal_bdev = bdev;
5378 	ext4_init_journal_params(sb, journal);
5379 	return journal;
5380 
5381 out_journal:
5382 	jbd2_journal_destroy(journal);
5383 out_bdev:
5384 	ext4_blkdev_put(bdev);
5385 	return NULL;
5386 }
5387 
5388 static int ext4_load_journal(struct super_block *sb,
5389 			     struct ext4_super_block *es,
5390 			     unsigned long journal_devnum)
5391 {
5392 	journal_t *journal;
5393 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5394 	dev_t journal_dev;
5395 	int err = 0;
5396 	int really_read_only;
5397 	int journal_dev_ro;
5398 
5399 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5400 		return -EFSCORRUPTED;
5401 
5402 	if (journal_devnum &&
5403 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5404 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5405 			"numbers have changed");
5406 		journal_dev = new_decode_dev(journal_devnum);
5407 	} else
5408 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5409 
5410 	if (journal_inum && journal_dev) {
5411 		ext4_msg(sb, KERN_ERR,
5412 			 "filesystem has both journal inode and journal device!");
5413 		return -EINVAL;
5414 	}
5415 
5416 	if (journal_inum) {
5417 		journal = ext4_get_journal(sb, journal_inum);
5418 		if (!journal)
5419 			return -EINVAL;
5420 	} else {
5421 		journal = ext4_get_dev_journal(sb, journal_dev);
5422 		if (!journal)
5423 			return -EINVAL;
5424 	}
5425 
5426 	journal_dev_ro = bdev_read_only(journal->j_dev);
5427 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5428 
5429 	if (journal_dev_ro && !sb_rdonly(sb)) {
5430 		ext4_msg(sb, KERN_ERR,
5431 			 "journal device read-only, try mounting with '-o ro'");
5432 		err = -EROFS;
5433 		goto err_out;
5434 	}
5435 
5436 	/*
5437 	 * Are we loading a blank journal or performing recovery after a
5438 	 * crash?  For recovery, we need to check in advance whether we
5439 	 * can get read-write access to the device.
5440 	 */
5441 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5442 		if (sb_rdonly(sb)) {
5443 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5444 					"required on readonly filesystem");
5445 			if (really_read_only) {
5446 				ext4_msg(sb, KERN_ERR, "write access "
5447 					"unavailable, cannot proceed "
5448 					"(try mounting with noload)");
5449 				err = -EROFS;
5450 				goto err_out;
5451 			}
5452 			ext4_msg(sb, KERN_INFO, "write access will "
5453 			       "be enabled during recovery");
5454 		}
5455 	}
5456 
5457 	if (!(journal->j_flags & JBD2_BARRIER))
5458 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5459 
5460 	if (!ext4_has_feature_journal_needs_recovery(sb))
5461 		err = jbd2_journal_wipe(journal, !really_read_only);
5462 	if (!err) {
5463 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5464 		if (save)
5465 			memcpy(save, ((char *) es) +
5466 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5467 		err = jbd2_journal_load(journal);
5468 		if (save)
5469 			memcpy(((char *) es) + EXT4_S_ERR_START,
5470 			       save, EXT4_S_ERR_LEN);
5471 		kfree(save);
5472 	}
5473 
5474 	if (err) {
5475 		ext4_msg(sb, KERN_ERR, "error loading journal");
5476 		goto err_out;
5477 	}
5478 
5479 	EXT4_SB(sb)->s_journal = journal;
5480 	err = ext4_clear_journal_err(sb, es);
5481 	if (err) {
5482 		EXT4_SB(sb)->s_journal = NULL;
5483 		jbd2_journal_destroy(journal);
5484 		return err;
5485 	}
5486 
5487 	if (!really_read_only && journal_devnum &&
5488 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5489 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5490 
5491 		/* Make sure we flush the recovery flag to disk. */
5492 		ext4_commit_super(sb, 1);
5493 	}
5494 
5495 	return 0;
5496 
5497 err_out:
5498 	jbd2_journal_destroy(journal);
5499 	return err;
5500 }
5501 
5502 static int ext4_commit_super(struct super_block *sb, int sync)
5503 {
5504 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5505 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5506 	int error = 0;
5507 
5508 	if (!sbh || block_device_ejected(sb))
5509 		return error;
5510 
5511 	/*
5512 	 * If the file system is mounted read-only, don't update the
5513 	 * superblock write time.  This avoids updating the superblock
5514 	 * write time when we are mounting the root file system
5515 	 * read/only but we need to replay the journal; at that point,
5516 	 * for people who are east of GMT and who make their clock
5517 	 * tick in localtime for Windows bug-for-bug compatibility,
5518 	 * the clock is set in the future, and this will cause e2fsck
5519 	 * to complain and force a full file system check.
5520 	 */
5521 	if (!(sb->s_flags & SB_RDONLY))
5522 		ext4_update_tstamp(es, s_wtime);
5523 	if (sb->s_bdev->bd_part)
5524 		es->s_kbytes_written =
5525 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5526 			    ((part_stat_read(sb->s_bdev->bd_part,
5527 					     sectors[STAT_WRITE]) -
5528 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5529 	else
5530 		es->s_kbytes_written =
5531 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5532 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5533 		ext4_free_blocks_count_set(es,
5534 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5535 				&EXT4_SB(sb)->s_freeclusters_counter)));
5536 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5537 		es->s_free_inodes_count =
5538 			cpu_to_le32(percpu_counter_sum_positive(
5539 				&EXT4_SB(sb)->s_freeinodes_counter));
5540 	BUFFER_TRACE(sbh, "marking dirty");
5541 	ext4_superblock_csum_set(sb);
5542 	if (sync)
5543 		lock_buffer(sbh);
5544 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5545 		/*
5546 		 * Oh, dear.  A previous attempt to write the
5547 		 * superblock failed.  This could happen because the
5548 		 * USB device was yanked out.  Or it could happen to
5549 		 * be a transient write error and maybe the block will
5550 		 * be remapped.  Nothing we can do but to retry the
5551 		 * write and hope for the best.
5552 		 */
5553 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5554 		       "superblock detected");
5555 		clear_buffer_write_io_error(sbh);
5556 		set_buffer_uptodate(sbh);
5557 	}
5558 	mark_buffer_dirty(sbh);
5559 	if (sync) {
5560 		unlock_buffer(sbh);
5561 		error = __sync_dirty_buffer(sbh,
5562 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5563 		if (buffer_write_io_error(sbh)) {
5564 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5565 			       "superblock");
5566 			clear_buffer_write_io_error(sbh);
5567 			set_buffer_uptodate(sbh);
5568 		}
5569 	}
5570 	return error;
5571 }
5572 
5573 /*
5574  * Have we just finished recovery?  If so, and if we are mounting (or
5575  * remounting) the filesystem readonly, then we will end up with a
5576  * consistent fs on disk.  Record that fact.
5577  */
5578 static int ext4_mark_recovery_complete(struct super_block *sb,
5579 				       struct ext4_super_block *es)
5580 {
5581 	int err;
5582 	journal_t *journal = EXT4_SB(sb)->s_journal;
5583 
5584 	if (!ext4_has_feature_journal(sb)) {
5585 		if (journal != NULL) {
5586 			ext4_error(sb, "Journal got removed while the fs was "
5587 				   "mounted!");
5588 			return -EFSCORRUPTED;
5589 		}
5590 		return 0;
5591 	}
5592 	jbd2_journal_lock_updates(journal);
5593 	err = jbd2_journal_flush(journal);
5594 	if (err < 0)
5595 		goto out;
5596 
5597 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5598 		ext4_clear_feature_journal_needs_recovery(sb);
5599 		ext4_commit_super(sb, 1);
5600 	}
5601 out:
5602 	jbd2_journal_unlock_updates(journal);
5603 	return err;
5604 }
5605 
5606 /*
5607  * If we are mounting (or read-write remounting) a filesystem whose journal
5608  * has recorded an error from a previous lifetime, move that error to the
5609  * main filesystem now.
5610  */
5611 static int ext4_clear_journal_err(struct super_block *sb,
5612 				   struct ext4_super_block *es)
5613 {
5614 	journal_t *journal;
5615 	int j_errno;
5616 	const char *errstr;
5617 
5618 	if (!ext4_has_feature_journal(sb)) {
5619 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5620 		return -EFSCORRUPTED;
5621 	}
5622 
5623 	journal = EXT4_SB(sb)->s_journal;
5624 
5625 	/*
5626 	 * Now check for any error status which may have been recorded in the
5627 	 * journal by a prior ext4_error() or ext4_abort()
5628 	 */
5629 
5630 	j_errno = jbd2_journal_errno(journal);
5631 	if (j_errno) {
5632 		char nbuf[16];
5633 
5634 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5635 		ext4_warning(sb, "Filesystem error recorded "
5636 			     "from previous mount: %s", errstr);
5637 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5638 
5639 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5640 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5641 		ext4_commit_super(sb, 1);
5642 
5643 		jbd2_journal_clear_err(journal);
5644 		jbd2_journal_update_sb_errno(journal);
5645 	}
5646 	return 0;
5647 }
5648 
5649 /*
5650  * Force the running and committing transactions to commit,
5651  * and wait on the commit.
5652  */
5653 int ext4_force_commit(struct super_block *sb)
5654 {
5655 	journal_t *journal;
5656 
5657 	if (sb_rdonly(sb))
5658 		return 0;
5659 
5660 	journal = EXT4_SB(sb)->s_journal;
5661 	return ext4_journal_force_commit(journal);
5662 }
5663 
5664 static int ext4_sync_fs(struct super_block *sb, int wait)
5665 {
5666 	int ret = 0;
5667 	tid_t target;
5668 	bool needs_barrier = false;
5669 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5670 
5671 	if (unlikely(ext4_forced_shutdown(sbi)))
5672 		return 0;
5673 
5674 	trace_ext4_sync_fs(sb, wait);
5675 	flush_workqueue(sbi->rsv_conversion_wq);
5676 	/*
5677 	 * Writeback quota in non-journalled quota case - journalled quota has
5678 	 * no dirty dquots
5679 	 */
5680 	dquot_writeback_dquots(sb, -1);
5681 	/*
5682 	 * Data writeback is possible w/o journal transaction, so barrier must
5683 	 * being sent at the end of the function. But we can skip it if
5684 	 * transaction_commit will do it for us.
5685 	 */
5686 	if (sbi->s_journal) {
5687 		target = jbd2_get_latest_transaction(sbi->s_journal);
5688 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5689 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5690 			needs_barrier = true;
5691 
5692 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5693 			if (wait)
5694 				ret = jbd2_log_wait_commit(sbi->s_journal,
5695 							   target);
5696 		}
5697 	} else if (wait && test_opt(sb, BARRIER))
5698 		needs_barrier = true;
5699 	if (needs_barrier) {
5700 		int err;
5701 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL);
5702 		if (!ret)
5703 			ret = err;
5704 	}
5705 
5706 	return ret;
5707 }
5708 
5709 /*
5710  * LVM calls this function before a (read-only) snapshot is created.  This
5711  * gives us a chance to flush the journal completely and mark the fs clean.
5712  *
5713  * Note that only this function cannot bring a filesystem to be in a clean
5714  * state independently. It relies on upper layer to stop all data & metadata
5715  * modifications.
5716  */
5717 static int ext4_freeze(struct super_block *sb)
5718 {
5719 	int error = 0;
5720 	journal_t *journal;
5721 
5722 	if (sb_rdonly(sb))
5723 		return 0;
5724 
5725 	journal = EXT4_SB(sb)->s_journal;
5726 
5727 	if (journal) {
5728 		/* Now we set up the journal barrier. */
5729 		jbd2_journal_lock_updates(journal);
5730 
5731 		/*
5732 		 * Don't clear the needs_recovery flag if we failed to
5733 		 * flush the journal.
5734 		 */
5735 		error = jbd2_journal_flush(journal);
5736 		if (error < 0)
5737 			goto out;
5738 
5739 		/* Journal blocked and flushed, clear needs_recovery flag. */
5740 		ext4_clear_feature_journal_needs_recovery(sb);
5741 	}
5742 
5743 	error = ext4_commit_super(sb, 1);
5744 out:
5745 	if (journal)
5746 		/* we rely on upper layer to stop further updates */
5747 		jbd2_journal_unlock_updates(journal);
5748 	return error;
5749 }
5750 
5751 /*
5752  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5753  * flag here, even though the filesystem is not technically dirty yet.
5754  */
5755 static int ext4_unfreeze(struct super_block *sb)
5756 {
5757 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5758 		return 0;
5759 
5760 	if (EXT4_SB(sb)->s_journal) {
5761 		/* Reset the needs_recovery flag before the fs is unlocked. */
5762 		ext4_set_feature_journal_needs_recovery(sb);
5763 	}
5764 
5765 	ext4_commit_super(sb, 1);
5766 	return 0;
5767 }
5768 
5769 /*
5770  * Structure to save mount options for ext4_remount's benefit
5771  */
5772 struct ext4_mount_options {
5773 	unsigned long s_mount_opt;
5774 	unsigned long s_mount_opt2;
5775 	kuid_t s_resuid;
5776 	kgid_t s_resgid;
5777 	unsigned long s_commit_interval;
5778 	u32 s_min_batch_time, s_max_batch_time;
5779 #ifdef CONFIG_QUOTA
5780 	int s_jquota_fmt;
5781 	char *s_qf_names[EXT4_MAXQUOTAS];
5782 #endif
5783 };
5784 
5785 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5786 {
5787 	struct ext4_super_block *es;
5788 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5789 	unsigned long old_sb_flags, vfs_flags;
5790 	struct ext4_mount_options old_opts;
5791 	int enable_quota = 0;
5792 	ext4_group_t g;
5793 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5794 	int err = 0;
5795 #ifdef CONFIG_QUOTA
5796 	int i, j;
5797 	char *to_free[EXT4_MAXQUOTAS];
5798 #endif
5799 	char *orig_data = kstrdup(data, GFP_KERNEL);
5800 
5801 	if (data && !orig_data)
5802 		return -ENOMEM;
5803 
5804 	/* Store the original options */
5805 	old_sb_flags = sb->s_flags;
5806 	old_opts.s_mount_opt = sbi->s_mount_opt;
5807 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5808 	old_opts.s_resuid = sbi->s_resuid;
5809 	old_opts.s_resgid = sbi->s_resgid;
5810 	old_opts.s_commit_interval = sbi->s_commit_interval;
5811 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5812 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5813 #ifdef CONFIG_QUOTA
5814 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5815 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5816 		if (sbi->s_qf_names[i]) {
5817 			char *qf_name = get_qf_name(sb, sbi, i);
5818 
5819 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5820 			if (!old_opts.s_qf_names[i]) {
5821 				for (j = 0; j < i; j++)
5822 					kfree(old_opts.s_qf_names[j]);
5823 				kfree(orig_data);
5824 				return -ENOMEM;
5825 			}
5826 		} else
5827 			old_opts.s_qf_names[i] = NULL;
5828 #endif
5829 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5830 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5831 
5832 	/*
5833 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5834 	 * either way we need to make sure it matches in both *flags and
5835 	 * s_flags. Copy those selected flags from *flags to s_flags
5836 	 */
5837 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5838 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5839 
5840 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5841 		err = -EINVAL;
5842 		goto restore_opts;
5843 	}
5844 
5845 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5846 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5847 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5848 			 "during remount not supported; ignoring");
5849 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5850 	}
5851 
5852 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5853 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5854 			ext4_msg(sb, KERN_ERR, "can't mount with "
5855 				 "both data=journal and delalloc");
5856 			err = -EINVAL;
5857 			goto restore_opts;
5858 		}
5859 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5860 			ext4_msg(sb, KERN_ERR, "can't mount with "
5861 				 "both data=journal and dioread_nolock");
5862 			err = -EINVAL;
5863 			goto restore_opts;
5864 		}
5865 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5866 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5867 			ext4_msg(sb, KERN_ERR, "can't mount with "
5868 				"journal_async_commit in data=ordered mode");
5869 			err = -EINVAL;
5870 			goto restore_opts;
5871 		}
5872 	}
5873 
5874 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5875 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5876 		err = -EINVAL;
5877 		goto restore_opts;
5878 	}
5879 
5880 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5881 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5882 
5883 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5884 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5885 
5886 	es = sbi->s_es;
5887 
5888 	if (sbi->s_journal) {
5889 		ext4_init_journal_params(sb, sbi->s_journal);
5890 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5891 	}
5892 
5893 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5894 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
5895 			err = -EROFS;
5896 			goto restore_opts;
5897 		}
5898 
5899 		if (*flags & SB_RDONLY) {
5900 			err = sync_filesystem(sb);
5901 			if (err < 0)
5902 				goto restore_opts;
5903 			err = dquot_suspend(sb, -1);
5904 			if (err < 0)
5905 				goto restore_opts;
5906 
5907 			/*
5908 			 * First of all, the unconditional stuff we have to do
5909 			 * to disable replay of the journal when we next remount
5910 			 */
5911 			sb->s_flags |= SB_RDONLY;
5912 
5913 			/*
5914 			 * OK, test if we are remounting a valid rw partition
5915 			 * readonly, and if so set the rdonly flag and then
5916 			 * mark the partition as valid again.
5917 			 */
5918 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5919 			    (sbi->s_mount_state & EXT4_VALID_FS))
5920 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5921 
5922 			if (sbi->s_journal) {
5923 				/*
5924 				 * We let remount-ro finish even if marking fs
5925 				 * as clean failed...
5926 				 */
5927 				ext4_mark_recovery_complete(sb, es);
5928 			}
5929 			if (sbi->s_mmp_tsk)
5930 				kthread_stop(sbi->s_mmp_tsk);
5931 		} else {
5932 			/* Make sure we can mount this feature set readwrite */
5933 			if (ext4_has_feature_readonly(sb) ||
5934 			    !ext4_feature_set_ok(sb, 0)) {
5935 				err = -EROFS;
5936 				goto restore_opts;
5937 			}
5938 			/*
5939 			 * Make sure the group descriptor checksums
5940 			 * are sane.  If they aren't, refuse to remount r/w.
5941 			 */
5942 			for (g = 0; g < sbi->s_groups_count; g++) {
5943 				struct ext4_group_desc *gdp =
5944 					ext4_get_group_desc(sb, g, NULL);
5945 
5946 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5947 					ext4_msg(sb, KERN_ERR,
5948 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5949 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5950 					       le16_to_cpu(gdp->bg_checksum));
5951 					err = -EFSBADCRC;
5952 					goto restore_opts;
5953 				}
5954 			}
5955 
5956 			/*
5957 			 * If we have an unprocessed orphan list hanging
5958 			 * around from a previously readonly bdev mount,
5959 			 * require a full umount/remount for now.
5960 			 */
5961 			if (es->s_last_orphan) {
5962 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5963 				       "remount RDWR because of unprocessed "
5964 				       "orphan inode list.  Please "
5965 				       "umount/remount instead");
5966 				err = -EINVAL;
5967 				goto restore_opts;
5968 			}
5969 
5970 			/*
5971 			 * Mounting a RDONLY partition read-write, so reread
5972 			 * and store the current valid flag.  (It may have
5973 			 * been changed by e2fsck since we originally mounted
5974 			 * the partition.)
5975 			 */
5976 			if (sbi->s_journal) {
5977 				err = ext4_clear_journal_err(sb, es);
5978 				if (err)
5979 					goto restore_opts;
5980 			}
5981 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5982 
5983 			err = ext4_setup_super(sb, es, 0);
5984 			if (err)
5985 				goto restore_opts;
5986 
5987 			sb->s_flags &= ~SB_RDONLY;
5988 			if (ext4_has_feature_mmp(sb))
5989 				if (ext4_multi_mount_protect(sb,
5990 						le64_to_cpu(es->s_mmp_block))) {
5991 					err = -EROFS;
5992 					goto restore_opts;
5993 				}
5994 			enable_quota = 1;
5995 		}
5996 	}
5997 
5998 	/*
5999 	 * Reinitialize lazy itable initialization thread based on
6000 	 * current settings
6001 	 */
6002 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6003 		ext4_unregister_li_request(sb);
6004 	else {
6005 		ext4_group_t first_not_zeroed;
6006 		first_not_zeroed = ext4_has_uninit_itable(sb);
6007 		ext4_register_li_request(sb, first_not_zeroed);
6008 	}
6009 
6010 	/*
6011 	 * Handle creation of system zone data early because it can fail.
6012 	 * Releasing of existing data is done when we are sure remount will
6013 	 * succeed.
6014 	 */
6015 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6016 		err = ext4_setup_system_zone(sb);
6017 		if (err)
6018 			goto restore_opts;
6019 	}
6020 
6021 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6022 		err = ext4_commit_super(sb, 1);
6023 		if (err)
6024 			goto restore_opts;
6025 	}
6026 
6027 #ifdef CONFIG_QUOTA
6028 	/* Release old quota file names */
6029 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6030 		kfree(old_opts.s_qf_names[i]);
6031 	if (enable_quota) {
6032 		if (sb_any_quota_suspended(sb))
6033 			dquot_resume(sb, -1);
6034 		else if (ext4_has_feature_quota(sb)) {
6035 			err = ext4_enable_quotas(sb);
6036 			if (err)
6037 				goto restore_opts;
6038 		}
6039 	}
6040 #endif
6041 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6042 		ext4_release_system_zone(sb);
6043 
6044 	/*
6045 	 * Some options can be enabled by ext4 and/or by VFS mount flag
6046 	 * either way we need to make sure it matches in both *flags and
6047 	 * s_flags. Copy those selected flags from s_flags to *flags
6048 	 */
6049 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6050 
6051 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
6052 	kfree(orig_data);
6053 	return 0;
6054 
6055 restore_opts:
6056 	sb->s_flags = old_sb_flags;
6057 	sbi->s_mount_opt = old_opts.s_mount_opt;
6058 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6059 	sbi->s_resuid = old_opts.s_resuid;
6060 	sbi->s_resgid = old_opts.s_resgid;
6061 	sbi->s_commit_interval = old_opts.s_commit_interval;
6062 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6063 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6064 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6065 		ext4_release_system_zone(sb);
6066 #ifdef CONFIG_QUOTA
6067 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6068 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6069 		to_free[i] = get_qf_name(sb, sbi, i);
6070 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6071 	}
6072 	synchronize_rcu();
6073 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6074 		kfree(to_free[i]);
6075 #endif
6076 	kfree(orig_data);
6077 	return err;
6078 }
6079 
6080 #ifdef CONFIG_QUOTA
6081 static int ext4_statfs_project(struct super_block *sb,
6082 			       kprojid_t projid, struct kstatfs *buf)
6083 {
6084 	struct kqid qid;
6085 	struct dquot *dquot;
6086 	u64 limit;
6087 	u64 curblock;
6088 
6089 	qid = make_kqid_projid(projid);
6090 	dquot = dqget(sb, qid);
6091 	if (IS_ERR(dquot))
6092 		return PTR_ERR(dquot);
6093 	spin_lock(&dquot->dq_dqb_lock);
6094 
6095 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6096 			     dquot->dq_dqb.dqb_bhardlimit);
6097 	limit >>= sb->s_blocksize_bits;
6098 
6099 	if (limit && buf->f_blocks > limit) {
6100 		curblock = (dquot->dq_dqb.dqb_curspace +
6101 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6102 		buf->f_blocks = limit;
6103 		buf->f_bfree = buf->f_bavail =
6104 			(buf->f_blocks > curblock) ?
6105 			 (buf->f_blocks - curblock) : 0;
6106 	}
6107 
6108 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6109 			     dquot->dq_dqb.dqb_ihardlimit);
6110 	if (limit && buf->f_files > limit) {
6111 		buf->f_files = limit;
6112 		buf->f_ffree =
6113 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6114 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6115 	}
6116 
6117 	spin_unlock(&dquot->dq_dqb_lock);
6118 	dqput(dquot);
6119 	return 0;
6120 }
6121 #endif
6122 
6123 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6124 {
6125 	struct super_block *sb = dentry->d_sb;
6126 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6127 	struct ext4_super_block *es = sbi->s_es;
6128 	ext4_fsblk_t overhead = 0, resv_blocks;
6129 	u64 fsid;
6130 	s64 bfree;
6131 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6132 
6133 	if (!test_opt(sb, MINIX_DF))
6134 		overhead = sbi->s_overhead;
6135 
6136 	buf->f_type = EXT4_SUPER_MAGIC;
6137 	buf->f_bsize = sb->s_blocksize;
6138 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6139 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6140 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6141 	/* prevent underflow in case that few free space is available */
6142 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6143 	buf->f_bavail = buf->f_bfree -
6144 			(ext4_r_blocks_count(es) + resv_blocks);
6145 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6146 		buf->f_bavail = 0;
6147 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6148 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6149 	buf->f_namelen = EXT4_NAME_LEN;
6150 	fsid = le64_to_cpup((void *)es->s_uuid) ^
6151 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
6152 	buf->f_fsid = u64_to_fsid(fsid);
6153 
6154 #ifdef CONFIG_QUOTA
6155 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6156 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6157 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6158 #endif
6159 	return 0;
6160 }
6161 
6162 
6163 #ifdef CONFIG_QUOTA
6164 
6165 /*
6166  * Helper functions so that transaction is started before we acquire dqio_sem
6167  * to keep correct lock ordering of transaction > dqio_sem
6168  */
6169 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6170 {
6171 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6172 }
6173 
6174 static int ext4_write_dquot(struct dquot *dquot)
6175 {
6176 	int ret, err;
6177 	handle_t *handle;
6178 	struct inode *inode;
6179 
6180 	inode = dquot_to_inode(dquot);
6181 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6182 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6183 	if (IS_ERR(handle))
6184 		return PTR_ERR(handle);
6185 	ret = dquot_commit(dquot);
6186 	err = ext4_journal_stop(handle);
6187 	if (!ret)
6188 		ret = err;
6189 	return ret;
6190 }
6191 
6192 static int ext4_acquire_dquot(struct dquot *dquot)
6193 {
6194 	int ret, err;
6195 	handle_t *handle;
6196 
6197 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6198 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6199 	if (IS_ERR(handle))
6200 		return PTR_ERR(handle);
6201 	ret = dquot_acquire(dquot);
6202 	err = ext4_journal_stop(handle);
6203 	if (!ret)
6204 		ret = err;
6205 	return ret;
6206 }
6207 
6208 static int ext4_release_dquot(struct dquot *dquot)
6209 {
6210 	int ret, err;
6211 	handle_t *handle;
6212 
6213 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6214 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6215 	if (IS_ERR(handle)) {
6216 		/* Release dquot anyway to avoid endless cycle in dqput() */
6217 		dquot_release(dquot);
6218 		return PTR_ERR(handle);
6219 	}
6220 	ret = dquot_release(dquot);
6221 	err = ext4_journal_stop(handle);
6222 	if (!ret)
6223 		ret = err;
6224 	return ret;
6225 }
6226 
6227 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6228 {
6229 	struct super_block *sb = dquot->dq_sb;
6230 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6231 
6232 	/* Are we journaling quotas? */
6233 	if (ext4_has_feature_quota(sb) ||
6234 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
6235 		dquot_mark_dquot_dirty(dquot);
6236 		return ext4_write_dquot(dquot);
6237 	} else {
6238 		return dquot_mark_dquot_dirty(dquot);
6239 	}
6240 }
6241 
6242 static int ext4_write_info(struct super_block *sb, int type)
6243 {
6244 	int ret, err;
6245 	handle_t *handle;
6246 
6247 	/* Data block + inode block */
6248 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6249 	if (IS_ERR(handle))
6250 		return PTR_ERR(handle);
6251 	ret = dquot_commit_info(sb, type);
6252 	err = ext4_journal_stop(handle);
6253 	if (!ret)
6254 		ret = err;
6255 	return ret;
6256 }
6257 
6258 /*
6259  * Turn on quotas during mount time - we need to find
6260  * the quota file and such...
6261  */
6262 static int ext4_quota_on_mount(struct super_block *sb, int type)
6263 {
6264 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6265 					EXT4_SB(sb)->s_jquota_fmt, type);
6266 }
6267 
6268 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6269 {
6270 	struct ext4_inode_info *ei = EXT4_I(inode);
6271 
6272 	/* The first argument of lockdep_set_subclass has to be
6273 	 * *exactly* the same as the argument to init_rwsem() --- in
6274 	 * this case, in init_once() --- or lockdep gets unhappy
6275 	 * because the name of the lock is set using the
6276 	 * stringification of the argument to init_rwsem().
6277 	 */
6278 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6279 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6280 }
6281 
6282 /*
6283  * Standard function to be called on quota_on
6284  */
6285 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6286 			 const struct path *path)
6287 {
6288 	int err;
6289 
6290 	if (!test_opt(sb, QUOTA))
6291 		return -EINVAL;
6292 
6293 	/* Quotafile not on the same filesystem? */
6294 	if (path->dentry->d_sb != sb)
6295 		return -EXDEV;
6296 
6297 	/* Quota already enabled for this file? */
6298 	if (IS_NOQUOTA(d_inode(path->dentry)))
6299 		return -EBUSY;
6300 
6301 	/* Journaling quota? */
6302 	if (EXT4_SB(sb)->s_qf_names[type]) {
6303 		/* Quotafile not in fs root? */
6304 		if (path->dentry->d_parent != sb->s_root)
6305 			ext4_msg(sb, KERN_WARNING,
6306 				"Quota file not on filesystem root. "
6307 				"Journaled quota will not work");
6308 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6309 	} else {
6310 		/*
6311 		 * Clear the flag just in case mount options changed since
6312 		 * last time.
6313 		 */
6314 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6315 	}
6316 
6317 	/*
6318 	 * When we journal data on quota file, we have to flush journal to see
6319 	 * all updates to the file when we bypass pagecache...
6320 	 */
6321 	if (EXT4_SB(sb)->s_journal &&
6322 	    ext4_should_journal_data(d_inode(path->dentry))) {
6323 		/*
6324 		 * We don't need to lock updates but journal_flush() could
6325 		 * otherwise be livelocked...
6326 		 */
6327 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6328 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
6329 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6330 		if (err)
6331 			return err;
6332 	}
6333 
6334 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6335 	err = dquot_quota_on(sb, type, format_id, path);
6336 	if (err) {
6337 		lockdep_set_quota_inode(path->dentry->d_inode,
6338 					     I_DATA_SEM_NORMAL);
6339 	} else {
6340 		struct inode *inode = d_inode(path->dentry);
6341 		handle_t *handle;
6342 
6343 		/*
6344 		 * Set inode flags to prevent userspace from messing with quota
6345 		 * files. If this fails, we return success anyway since quotas
6346 		 * are already enabled and this is not a hard failure.
6347 		 */
6348 		inode_lock(inode);
6349 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6350 		if (IS_ERR(handle))
6351 			goto unlock_inode;
6352 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6353 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6354 				S_NOATIME | S_IMMUTABLE);
6355 		err = ext4_mark_inode_dirty(handle, inode);
6356 		ext4_journal_stop(handle);
6357 	unlock_inode:
6358 		inode_unlock(inode);
6359 	}
6360 	return err;
6361 }
6362 
6363 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6364 			     unsigned int flags)
6365 {
6366 	int err;
6367 	struct inode *qf_inode;
6368 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6369 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6370 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6371 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6372 	};
6373 
6374 	BUG_ON(!ext4_has_feature_quota(sb));
6375 
6376 	if (!qf_inums[type])
6377 		return -EPERM;
6378 
6379 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6380 	if (IS_ERR(qf_inode)) {
6381 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6382 		return PTR_ERR(qf_inode);
6383 	}
6384 
6385 	/* Don't account quota for quota files to avoid recursion */
6386 	qf_inode->i_flags |= S_NOQUOTA;
6387 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6388 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6389 	if (err)
6390 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6391 	iput(qf_inode);
6392 
6393 	return err;
6394 }
6395 
6396 /* Enable usage tracking for all quota types. */
6397 static int ext4_enable_quotas(struct super_block *sb)
6398 {
6399 	int type, err = 0;
6400 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6401 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6402 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6403 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6404 	};
6405 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6406 		test_opt(sb, USRQUOTA),
6407 		test_opt(sb, GRPQUOTA),
6408 		test_opt(sb, PRJQUOTA),
6409 	};
6410 
6411 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6412 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6413 		if (qf_inums[type]) {
6414 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6415 				DQUOT_USAGE_ENABLED |
6416 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6417 			if (err) {
6418 				ext4_warning(sb,
6419 					"Failed to enable quota tracking "
6420 					"(type=%d, err=%d). Please run "
6421 					"e2fsck to fix.", type, err);
6422 				for (type--; type >= 0; type--)
6423 					dquot_quota_off(sb, type);
6424 
6425 				return err;
6426 			}
6427 		}
6428 	}
6429 	return 0;
6430 }
6431 
6432 static int ext4_quota_off(struct super_block *sb, int type)
6433 {
6434 	struct inode *inode = sb_dqopt(sb)->files[type];
6435 	handle_t *handle;
6436 	int err;
6437 
6438 	/* Force all delayed allocation blocks to be allocated.
6439 	 * Caller already holds s_umount sem */
6440 	if (test_opt(sb, DELALLOC))
6441 		sync_filesystem(sb);
6442 
6443 	if (!inode || !igrab(inode))
6444 		goto out;
6445 
6446 	err = dquot_quota_off(sb, type);
6447 	if (err || ext4_has_feature_quota(sb))
6448 		goto out_put;
6449 
6450 	inode_lock(inode);
6451 	/*
6452 	 * Update modification times of quota files when userspace can
6453 	 * start looking at them. If we fail, we return success anyway since
6454 	 * this is not a hard failure and quotas are already disabled.
6455 	 */
6456 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6457 	if (IS_ERR(handle)) {
6458 		err = PTR_ERR(handle);
6459 		goto out_unlock;
6460 	}
6461 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6462 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6463 	inode->i_mtime = inode->i_ctime = current_time(inode);
6464 	err = ext4_mark_inode_dirty(handle, inode);
6465 	ext4_journal_stop(handle);
6466 out_unlock:
6467 	inode_unlock(inode);
6468 out_put:
6469 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6470 	iput(inode);
6471 	return err;
6472 out:
6473 	return dquot_quota_off(sb, type);
6474 }
6475 
6476 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6477  * acquiring the locks... As quota files are never truncated and quota code
6478  * itself serializes the operations (and no one else should touch the files)
6479  * we don't have to be afraid of races */
6480 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6481 			       size_t len, loff_t off)
6482 {
6483 	struct inode *inode = sb_dqopt(sb)->files[type];
6484 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6485 	int offset = off & (sb->s_blocksize - 1);
6486 	int tocopy;
6487 	size_t toread;
6488 	struct buffer_head *bh;
6489 	loff_t i_size = i_size_read(inode);
6490 
6491 	if (off > i_size)
6492 		return 0;
6493 	if (off+len > i_size)
6494 		len = i_size-off;
6495 	toread = len;
6496 	while (toread > 0) {
6497 		tocopy = sb->s_blocksize - offset < toread ?
6498 				sb->s_blocksize - offset : toread;
6499 		bh = ext4_bread(NULL, inode, blk, 0);
6500 		if (IS_ERR(bh))
6501 			return PTR_ERR(bh);
6502 		if (!bh)	/* A hole? */
6503 			memset(data, 0, tocopy);
6504 		else
6505 			memcpy(data, bh->b_data+offset, tocopy);
6506 		brelse(bh);
6507 		offset = 0;
6508 		toread -= tocopy;
6509 		data += tocopy;
6510 		blk++;
6511 	}
6512 	return len;
6513 }
6514 
6515 /* Write to quotafile (we know the transaction is already started and has
6516  * enough credits) */
6517 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6518 				const char *data, size_t len, loff_t off)
6519 {
6520 	struct inode *inode = sb_dqopt(sb)->files[type];
6521 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6522 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6523 	int retries = 0;
6524 	struct buffer_head *bh;
6525 	handle_t *handle = journal_current_handle();
6526 
6527 	if (EXT4_SB(sb)->s_journal && !handle) {
6528 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6529 			" cancelled because transaction is not started",
6530 			(unsigned long long)off, (unsigned long long)len);
6531 		return -EIO;
6532 	}
6533 	/*
6534 	 * Since we account only one data block in transaction credits,
6535 	 * then it is impossible to cross a block boundary.
6536 	 */
6537 	if (sb->s_blocksize - offset < len) {
6538 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6539 			" cancelled because not block aligned",
6540 			(unsigned long long)off, (unsigned long long)len);
6541 		return -EIO;
6542 	}
6543 
6544 	do {
6545 		bh = ext4_bread(handle, inode, blk,
6546 				EXT4_GET_BLOCKS_CREATE |
6547 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6548 	} while (PTR_ERR(bh) == -ENOSPC &&
6549 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6550 	if (IS_ERR(bh))
6551 		return PTR_ERR(bh);
6552 	if (!bh)
6553 		goto out;
6554 	BUFFER_TRACE(bh, "get write access");
6555 	err = ext4_journal_get_write_access(handle, bh);
6556 	if (err) {
6557 		brelse(bh);
6558 		return err;
6559 	}
6560 	lock_buffer(bh);
6561 	memcpy(bh->b_data+offset, data, len);
6562 	flush_dcache_page(bh->b_page);
6563 	unlock_buffer(bh);
6564 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6565 	brelse(bh);
6566 out:
6567 	if (inode->i_size < off + len) {
6568 		i_size_write(inode, off + len);
6569 		EXT4_I(inode)->i_disksize = inode->i_size;
6570 		err2 = ext4_mark_inode_dirty(handle, inode);
6571 		if (unlikely(err2 && !err))
6572 			err = err2;
6573 	}
6574 	return err ? err : len;
6575 }
6576 #endif
6577 
6578 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6579 		       const char *dev_name, void *data)
6580 {
6581 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6582 }
6583 
6584 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6585 static inline void register_as_ext2(void)
6586 {
6587 	int err = register_filesystem(&ext2_fs_type);
6588 	if (err)
6589 		printk(KERN_WARNING
6590 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6591 }
6592 
6593 static inline void unregister_as_ext2(void)
6594 {
6595 	unregister_filesystem(&ext2_fs_type);
6596 }
6597 
6598 static inline int ext2_feature_set_ok(struct super_block *sb)
6599 {
6600 	if (ext4_has_unknown_ext2_incompat_features(sb))
6601 		return 0;
6602 	if (sb_rdonly(sb))
6603 		return 1;
6604 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6605 		return 0;
6606 	return 1;
6607 }
6608 #else
6609 static inline void register_as_ext2(void) { }
6610 static inline void unregister_as_ext2(void) { }
6611 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6612 #endif
6613 
6614 static inline void register_as_ext3(void)
6615 {
6616 	int err = register_filesystem(&ext3_fs_type);
6617 	if (err)
6618 		printk(KERN_WARNING
6619 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6620 }
6621 
6622 static inline void unregister_as_ext3(void)
6623 {
6624 	unregister_filesystem(&ext3_fs_type);
6625 }
6626 
6627 static inline int ext3_feature_set_ok(struct super_block *sb)
6628 {
6629 	if (ext4_has_unknown_ext3_incompat_features(sb))
6630 		return 0;
6631 	if (!ext4_has_feature_journal(sb))
6632 		return 0;
6633 	if (sb_rdonly(sb))
6634 		return 1;
6635 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6636 		return 0;
6637 	return 1;
6638 }
6639 
6640 static struct file_system_type ext4_fs_type = {
6641 	.owner		= THIS_MODULE,
6642 	.name		= "ext4",
6643 	.mount		= ext4_mount,
6644 	.kill_sb	= kill_block_super,
6645 	.fs_flags	= FS_REQUIRES_DEV,
6646 };
6647 MODULE_ALIAS_FS("ext4");
6648 
6649 /* Shared across all ext4 file systems */
6650 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6651 
6652 static int __init ext4_init_fs(void)
6653 {
6654 	int i, err;
6655 
6656 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6657 	ext4_li_info = NULL;
6658 	mutex_init(&ext4_li_mtx);
6659 
6660 	/* Build-time check for flags consistency */
6661 	ext4_check_flag_values();
6662 
6663 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6664 		init_waitqueue_head(&ext4__ioend_wq[i]);
6665 
6666 	err = ext4_init_es();
6667 	if (err)
6668 		return err;
6669 
6670 	err = ext4_init_pending();
6671 	if (err)
6672 		goto out7;
6673 
6674 	err = ext4_init_post_read_processing();
6675 	if (err)
6676 		goto out6;
6677 
6678 	err = ext4_init_pageio();
6679 	if (err)
6680 		goto out5;
6681 
6682 	err = ext4_init_system_zone();
6683 	if (err)
6684 		goto out4;
6685 
6686 	err = ext4_init_sysfs();
6687 	if (err)
6688 		goto out3;
6689 
6690 	err = ext4_init_mballoc();
6691 	if (err)
6692 		goto out2;
6693 	err = init_inodecache();
6694 	if (err)
6695 		goto out1;
6696 
6697 	err = ext4_fc_init_dentry_cache();
6698 	if (err)
6699 		goto out05;
6700 
6701 	register_as_ext3();
6702 	register_as_ext2();
6703 	err = register_filesystem(&ext4_fs_type);
6704 	if (err)
6705 		goto out;
6706 
6707 	return 0;
6708 out:
6709 	unregister_as_ext2();
6710 	unregister_as_ext3();
6711 out05:
6712 	destroy_inodecache();
6713 out1:
6714 	ext4_exit_mballoc();
6715 out2:
6716 	ext4_exit_sysfs();
6717 out3:
6718 	ext4_exit_system_zone();
6719 out4:
6720 	ext4_exit_pageio();
6721 out5:
6722 	ext4_exit_post_read_processing();
6723 out6:
6724 	ext4_exit_pending();
6725 out7:
6726 	ext4_exit_es();
6727 
6728 	return err;
6729 }
6730 
6731 static void __exit ext4_exit_fs(void)
6732 {
6733 	ext4_destroy_lazyinit_thread();
6734 	unregister_as_ext2();
6735 	unregister_as_ext3();
6736 	unregister_filesystem(&ext4_fs_type);
6737 	destroy_inodecache();
6738 	ext4_exit_mballoc();
6739 	ext4_exit_sysfs();
6740 	ext4_exit_system_zone();
6741 	ext4_exit_pageio();
6742 	ext4_exit_post_read_processing();
6743 	ext4_exit_es();
6744 	ext4_exit_pending();
6745 }
6746 
6747 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6748 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6749 MODULE_LICENSE("GPL");
6750 MODULE_SOFTDEP("pre: crc32c");
6751 module_init(ext4_init_fs)
6752 module_exit(ext4_exit_fs)
6753