xref: /openbmc/linux/fs/ext4/super.c (revision 13dd8710)
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_SB(sb)->s_mount_flags |= 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_SB(sb)->s_mount_flags |= 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(sbi->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, Opt_no_fc,
1720 #ifdef CONFIG_EXT4_DEBUG
1721 	Opt_fc_debug_max_replay,
1722 #endif
1723 	Opt_fc_debug_force
1724 };
1725 
1726 static const match_table_t tokens = {
1727 	{Opt_bsd_df, "bsddf"},
1728 	{Opt_minix_df, "minixdf"},
1729 	{Opt_grpid, "grpid"},
1730 	{Opt_grpid, "bsdgroups"},
1731 	{Opt_nogrpid, "nogrpid"},
1732 	{Opt_nogrpid, "sysvgroups"},
1733 	{Opt_resgid, "resgid=%u"},
1734 	{Opt_resuid, "resuid=%u"},
1735 	{Opt_sb, "sb=%u"},
1736 	{Opt_err_cont, "errors=continue"},
1737 	{Opt_err_panic, "errors=panic"},
1738 	{Opt_err_ro, "errors=remount-ro"},
1739 	{Opt_nouid32, "nouid32"},
1740 	{Opt_debug, "debug"},
1741 	{Opt_removed, "oldalloc"},
1742 	{Opt_removed, "orlov"},
1743 	{Opt_user_xattr, "user_xattr"},
1744 	{Opt_nouser_xattr, "nouser_xattr"},
1745 	{Opt_acl, "acl"},
1746 	{Opt_noacl, "noacl"},
1747 	{Opt_noload, "norecovery"},
1748 	{Opt_noload, "noload"},
1749 	{Opt_removed, "nobh"},
1750 	{Opt_removed, "bh"},
1751 	{Opt_commit, "commit=%u"},
1752 	{Opt_min_batch_time, "min_batch_time=%u"},
1753 	{Opt_max_batch_time, "max_batch_time=%u"},
1754 	{Opt_journal_dev, "journal_dev=%u"},
1755 	{Opt_journal_path, "journal_path=%s"},
1756 	{Opt_journal_checksum, "journal_checksum"},
1757 	{Opt_nojournal_checksum, "nojournal_checksum"},
1758 	{Opt_journal_async_commit, "journal_async_commit"},
1759 	{Opt_abort, "abort"},
1760 	{Opt_data_journal, "data=journal"},
1761 	{Opt_data_ordered, "data=ordered"},
1762 	{Opt_data_writeback, "data=writeback"},
1763 	{Opt_data_err_abort, "data_err=abort"},
1764 	{Opt_data_err_ignore, "data_err=ignore"},
1765 	{Opt_offusrjquota, "usrjquota="},
1766 	{Opt_usrjquota, "usrjquota=%s"},
1767 	{Opt_offgrpjquota, "grpjquota="},
1768 	{Opt_grpjquota, "grpjquota=%s"},
1769 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1770 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1771 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1772 	{Opt_grpquota, "grpquota"},
1773 	{Opt_noquota, "noquota"},
1774 	{Opt_quota, "quota"},
1775 	{Opt_usrquota, "usrquota"},
1776 	{Opt_prjquota, "prjquota"},
1777 	{Opt_barrier, "barrier=%u"},
1778 	{Opt_barrier, "barrier"},
1779 	{Opt_nobarrier, "nobarrier"},
1780 	{Opt_i_version, "i_version"},
1781 	{Opt_dax, "dax"},
1782 	{Opt_dax_always, "dax=always"},
1783 	{Opt_dax_inode, "dax=inode"},
1784 	{Opt_dax_never, "dax=never"},
1785 	{Opt_stripe, "stripe=%u"},
1786 	{Opt_delalloc, "delalloc"},
1787 	{Opt_warn_on_error, "warn_on_error"},
1788 	{Opt_nowarn_on_error, "nowarn_on_error"},
1789 	{Opt_lazytime, "lazytime"},
1790 	{Opt_nolazytime, "nolazytime"},
1791 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1792 	{Opt_nodelalloc, "nodelalloc"},
1793 	{Opt_removed, "mblk_io_submit"},
1794 	{Opt_removed, "nomblk_io_submit"},
1795 	{Opt_block_validity, "block_validity"},
1796 	{Opt_noblock_validity, "noblock_validity"},
1797 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1798 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1799 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1800 	{Opt_auto_da_alloc, "auto_da_alloc"},
1801 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1802 	{Opt_dioread_nolock, "dioread_nolock"},
1803 	{Opt_dioread_lock, "nodioread_nolock"},
1804 	{Opt_dioread_lock, "dioread_lock"},
1805 	{Opt_discard, "discard"},
1806 	{Opt_nodiscard, "nodiscard"},
1807 	{Opt_init_itable, "init_itable=%u"},
1808 	{Opt_init_itable, "init_itable"},
1809 	{Opt_noinit_itable, "noinit_itable"},
1810 	{Opt_no_fc, "no_fc"},
1811 	{Opt_fc_debug_force, "fc_debug_force"},
1812 #ifdef CONFIG_EXT4_DEBUG
1813 	{Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
1814 #endif
1815 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1816 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1817 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1818 	{Opt_inlinecrypt, "inlinecrypt"},
1819 	{Opt_nombcache, "nombcache"},
1820 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1821 	{Opt_prefetch_block_bitmaps, "prefetch_block_bitmaps"},
1822 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1823 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1824 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1825 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1826 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1827 	{Opt_err, NULL},
1828 };
1829 
1830 static ext4_fsblk_t get_sb_block(void **data)
1831 {
1832 	ext4_fsblk_t	sb_block;
1833 	char		*options = (char *) *data;
1834 
1835 	if (!options || strncmp(options, "sb=", 3) != 0)
1836 		return 1;	/* Default location */
1837 
1838 	options += 3;
1839 	/* TODO: use simple_strtoll with >32bit ext4 */
1840 	sb_block = simple_strtoul(options, &options, 0);
1841 	if (*options && *options != ',') {
1842 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1843 		       (char *) *data);
1844 		return 1;
1845 	}
1846 	if (*options == ',')
1847 		options++;
1848 	*data = (void *) options;
1849 
1850 	return sb_block;
1851 }
1852 
1853 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1854 static const char deprecated_msg[] =
1855 	"Mount option \"%s\" will be removed by %s\n"
1856 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1857 
1858 #ifdef CONFIG_QUOTA
1859 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1860 {
1861 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1862 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1863 	int ret = -1;
1864 
1865 	if (sb_any_quota_loaded(sb) && !old_qname) {
1866 		ext4_msg(sb, KERN_ERR,
1867 			"Cannot change journaled "
1868 			"quota options when quota turned on");
1869 		return -1;
1870 	}
1871 	if (ext4_has_feature_quota(sb)) {
1872 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1873 			 "ignored when QUOTA feature is enabled");
1874 		return 1;
1875 	}
1876 	qname = match_strdup(args);
1877 	if (!qname) {
1878 		ext4_msg(sb, KERN_ERR,
1879 			"Not enough memory for storing quotafile name");
1880 		return -1;
1881 	}
1882 	if (old_qname) {
1883 		if (strcmp(old_qname, qname) == 0)
1884 			ret = 1;
1885 		else
1886 			ext4_msg(sb, KERN_ERR,
1887 				 "%s quota file already specified",
1888 				 QTYPE2NAME(qtype));
1889 		goto errout;
1890 	}
1891 	if (strchr(qname, '/')) {
1892 		ext4_msg(sb, KERN_ERR,
1893 			"quotafile must be on filesystem root");
1894 		goto errout;
1895 	}
1896 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1897 	set_opt(sb, QUOTA);
1898 	return 1;
1899 errout:
1900 	kfree(qname);
1901 	return ret;
1902 }
1903 
1904 static int clear_qf_name(struct super_block *sb, int qtype)
1905 {
1906 
1907 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1908 	char *old_qname = get_qf_name(sb, sbi, qtype);
1909 
1910 	if (sb_any_quota_loaded(sb) && old_qname) {
1911 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1912 			" when quota turned on");
1913 		return -1;
1914 	}
1915 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1916 	synchronize_rcu();
1917 	kfree(old_qname);
1918 	return 1;
1919 }
1920 #endif
1921 
1922 #define MOPT_SET	0x0001
1923 #define MOPT_CLEAR	0x0002
1924 #define MOPT_NOSUPPORT	0x0004
1925 #define MOPT_EXPLICIT	0x0008
1926 #define MOPT_CLEAR_ERR	0x0010
1927 #define MOPT_GTE0	0x0020
1928 #ifdef CONFIG_QUOTA
1929 #define MOPT_Q		0
1930 #define MOPT_QFMT	0x0040
1931 #else
1932 #define MOPT_Q		MOPT_NOSUPPORT
1933 #define MOPT_QFMT	MOPT_NOSUPPORT
1934 #endif
1935 #define MOPT_DATAJ	0x0080
1936 #define MOPT_NO_EXT2	0x0100
1937 #define MOPT_NO_EXT3	0x0200
1938 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1939 #define MOPT_STRING	0x0400
1940 #define MOPT_SKIP	0x0800
1941 #define	MOPT_2		0x1000
1942 
1943 static const struct mount_opts {
1944 	int	token;
1945 	int	mount_opt;
1946 	int	flags;
1947 } ext4_mount_opts[] = {
1948 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1949 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1950 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1951 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1952 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1953 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1954 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1955 	 MOPT_EXT4_ONLY | MOPT_SET},
1956 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1957 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1958 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1959 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1960 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1961 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1962 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1963 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1964 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1965 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1966 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1967 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1968 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1969 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1970 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1971 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1972 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1973 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1974 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1975 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1976 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1977 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1978 	 MOPT_NO_EXT2},
1979 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1980 	 MOPT_NO_EXT2},
1981 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1982 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1983 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1984 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1985 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1986 	{Opt_commit, 0, MOPT_GTE0},
1987 	{Opt_max_batch_time, 0, MOPT_GTE0},
1988 	{Opt_min_batch_time, 0, MOPT_GTE0},
1989 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1990 	{Opt_init_itable, 0, MOPT_GTE0},
1991 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1992 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1993 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1994 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1995 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1996 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1997 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1998 	{Opt_stripe, 0, MOPT_GTE0},
1999 	{Opt_resuid, 0, MOPT_GTE0},
2000 	{Opt_resgid, 0, MOPT_GTE0},
2001 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
2002 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
2003 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
2004 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
2005 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
2006 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
2007 	 MOPT_NO_EXT2 | MOPT_DATAJ},
2008 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
2009 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
2010 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2011 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
2012 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
2013 #else
2014 	{Opt_acl, 0, MOPT_NOSUPPORT},
2015 	{Opt_noacl, 0, MOPT_NOSUPPORT},
2016 #endif
2017 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
2018 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
2019 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
2020 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
2021 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
2022 							MOPT_SET | MOPT_Q},
2023 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
2024 							MOPT_SET | MOPT_Q},
2025 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
2026 							MOPT_SET | MOPT_Q},
2027 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2028 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
2029 							MOPT_CLEAR | MOPT_Q},
2030 	{Opt_usrjquota, 0, MOPT_Q},
2031 	{Opt_grpjquota, 0, MOPT_Q},
2032 	{Opt_offusrjquota, 0, MOPT_Q},
2033 	{Opt_offgrpjquota, 0, MOPT_Q},
2034 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
2035 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
2036 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
2037 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
2038 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
2039 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
2040 	{Opt_prefetch_block_bitmaps, EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS,
2041 	 MOPT_SET},
2042 	{Opt_no_fc, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2043 	 MOPT_CLEAR | MOPT_2 | MOPT_EXT4_ONLY},
2044 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2045 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
2046 #ifdef CONFIG_EXT4_DEBUG
2047 	{Opt_fc_debug_max_replay, 0, MOPT_GTE0},
2048 #endif
2049 	{Opt_err, 0, 0}
2050 };
2051 
2052 #ifdef CONFIG_UNICODE
2053 static const struct ext4_sb_encodings {
2054 	__u16 magic;
2055 	char *name;
2056 	char *version;
2057 } ext4_sb_encoding_map[] = {
2058 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
2059 };
2060 
2061 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
2062 				 const struct ext4_sb_encodings **encoding,
2063 				 __u16 *flags)
2064 {
2065 	__u16 magic = le16_to_cpu(es->s_encoding);
2066 	int i;
2067 
2068 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
2069 		if (magic == ext4_sb_encoding_map[i].magic)
2070 			break;
2071 
2072 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
2073 		return -EINVAL;
2074 
2075 	*encoding = &ext4_sb_encoding_map[i];
2076 	*flags = le16_to_cpu(es->s_encoding_flags);
2077 
2078 	return 0;
2079 }
2080 #endif
2081 
2082 static int ext4_set_test_dummy_encryption(struct super_block *sb,
2083 					  const char *opt,
2084 					  const substring_t *arg,
2085 					  bool is_remount)
2086 {
2087 #ifdef CONFIG_FS_ENCRYPTION
2088 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2089 	int err;
2090 
2091 	/*
2092 	 * This mount option is just for testing, and it's not worthwhile to
2093 	 * implement the extra complexity (e.g. RCU protection) that would be
2094 	 * needed to allow it to be set or changed during remount.  We do allow
2095 	 * it to be specified during remount, but only if there is no change.
2096 	 */
2097 	if (is_remount && !sbi->s_dummy_enc_policy.policy) {
2098 		ext4_msg(sb, KERN_WARNING,
2099 			 "Can't set test_dummy_encryption on remount");
2100 		return -1;
2101 	}
2102 	err = fscrypt_set_test_dummy_encryption(sb, arg->from,
2103 						&sbi->s_dummy_enc_policy);
2104 	if (err) {
2105 		if (err == -EEXIST)
2106 			ext4_msg(sb, KERN_WARNING,
2107 				 "Can't change test_dummy_encryption on remount");
2108 		else if (err == -EINVAL)
2109 			ext4_msg(sb, KERN_WARNING,
2110 				 "Value of option \"%s\" is unrecognized", opt);
2111 		else
2112 			ext4_msg(sb, KERN_WARNING,
2113 				 "Error processing option \"%s\" [%d]",
2114 				 opt, err);
2115 		return -1;
2116 	}
2117 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2118 #else
2119 	ext4_msg(sb, KERN_WARNING,
2120 		 "Test dummy encryption mount option ignored");
2121 #endif
2122 	return 1;
2123 }
2124 
2125 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
2126 			    substring_t *args, unsigned long *journal_devnum,
2127 			    unsigned int *journal_ioprio, int is_remount)
2128 {
2129 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2130 	const struct mount_opts *m;
2131 	kuid_t uid;
2132 	kgid_t gid;
2133 	int arg = 0;
2134 
2135 #ifdef CONFIG_QUOTA
2136 	if (token == Opt_usrjquota)
2137 		return set_qf_name(sb, USRQUOTA, &args[0]);
2138 	else if (token == Opt_grpjquota)
2139 		return set_qf_name(sb, GRPQUOTA, &args[0]);
2140 	else if (token == Opt_offusrjquota)
2141 		return clear_qf_name(sb, USRQUOTA);
2142 	else if (token == Opt_offgrpjquota)
2143 		return clear_qf_name(sb, GRPQUOTA);
2144 #endif
2145 	switch (token) {
2146 	case Opt_noacl:
2147 	case Opt_nouser_xattr:
2148 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
2149 		break;
2150 	case Opt_sb:
2151 		return 1;	/* handled by get_sb_block() */
2152 	case Opt_removed:
2153 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
2154 		return 1;
2155 	case Opt_abort:
2156 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
2157 		return 1;
2158 	case Opt_i_version:
2159 		sb->s_flags |= SB_I_VERSION;
2160 		return 1;
2161 	case Opt_lazytime:
2162 		sb->s_flags |= SB_LAZYTIME;
2163 		return 1;
2164 	case Opt_nolazytime:
2165 		sb->s_flags &= ~SB_LAZYTIME;
2166 		return 1;
2167 	case Opt_inlinecrypt:
2168 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2169 		sb->s_flags |= SB_INLINECRYPT;
2170 #else
2171 		ext4_msg(sb, KERN_ERR, "inline encryption not supported");
2172 #endif
2173 		return 1;
2174 	}
2175 
2176 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2177 		if (token == m->token)
2178 			break;
2179 
2180 	if (m->token == Opt_err) {
2181 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
2182 			 "or missing value", opt);
2183 		return -1;
2184 	}
2185 
2186 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2187 		ext4_msg(sb, KERN_ERR,
2188 			 "Mount option \"%s\" incompatible with ext2", opt);
2189 		return -1;
2190 	}
2191 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2192 		ext4_msg(sb, KERN_ERR,
2193 			 "Mount option \"%s\" incompatible with ext3", opt);
2194 		return -1;
2195 	}
2196 
2197 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
2198 		return -1;
2199 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
2200 		return -1;
2201 	if (m->flags & MOPT_EXPLICIT) {
2202 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2203 			set_opt2(sb, EXPLICIT_DELALLOC);
2204 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2205 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
2206 		} else
2207 			return -1;
2208 	}
2209 	if (m->flags & MOPT_CLEAR_ERR)
2210 		clear_opt(sb, ERRORS_MASK);
2211 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
2212 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
2213 			 "options when quota turned on");
2214 		return -1;
2215 	}
2216 
2217 	if (m->flags & MOPT_NOSUPPORT) {
2218 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
2219 	} else if (token == Opt_commit) {
2220 		if (arg == 0)
2221 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
2222 		else if (arg > INT_MAX / HZ) {
2223 			ext4_msg(sb, KERN_ERR,
2224 				 "Invalid commit interval %d, "
2225 				 "must be smaller than %d",
2226 				 arg, INT_MAX / HZ);
2227 			return -1;
2228 		}
2229 		sbi->s_commit_interval = HZ * arg;
2230 	} else if (token == Opt_debug_want_extra_isize) {
2231 		if ((arg & 1) ||
2232 		    (arg < 4) ||
2233 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2234 			ext4_msg(sb, KERN_ERR,
2235 				 "Invalid want_extra_isize %d", arg);
2236 			return -1;
2237 		}
2238 		sbi->s_want_extra_isize = arg;
2239 	} else if (token == Opt_max_batch_time) {
2240 		sbi->s_max_batch_time = arg;
2241 	} else if (token == Opt_min_batch_time) {
2242 		sbi->s_min_batch_time = arg;
2243 	} else if (token == Opt_inode_readahead_blks) {
2244 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2245 			ext4_msg(sb, KERN_ERR,
2246 				 "EXT4-fs: inode_readahead_blks must be "
2247 				 "0 or a power of 2 smaller than 2^31");
2248 			return -1;
2249 		}
2250 		sbi->s_inode_readahead_blks = arg;
2251 	} else if (token == Opt_init_itable) {
2252 		set_opt(sb, INIT_INODE_TABLE);
2253 		if (!args->from)
2254 			arg = EXT4_DEF_LI_WAIT_MULT;
2255 		sbi->s_li_wait_mult = arg;
2256 	} else if (token == Opt_max_dir_size_kb) {
2257 		sbi->s_max_dir_size_kb = arg;
2258 #ifdef CONFIG_EXT4_DEBUG
2259 	} else if (token == Opt_fc_debug_max_replay) {
2260 		sbi->s_fc_debug_max_replay = arg;
2261 #endif
2262 	} else if (token == Opt_stripe) {
2263 		sbi->s_stripe = arg;
2264 	} else if (token == Opt_resuid) {
2265 		uid = make_kuid(current_user_ns(), arg);
2266 		if (!uid_valid(uid)) {
2267 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2268 			return -1;
2269 		}
2270 		sbi->s_resuid = uid;
2271 	} else if (token == Opt_resgid) {
2272 		gid = make_kgid(current_user_ns(), arg);
2273 		if (!gid_valid(gid)) {
2274 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2275 			return -1;
2276 		}
2277 		sbi->s_resgid = gid;
2278 	} else if (token == Opt_journal_dev) {
2279 		if (is_remount) {
2280 			ext4_msg(sb, KERN_ERR,
2281 				 "Cannot specify journal on remount");
2282 			return -1;
2283 		}
2284 		*journal_devnum = arg;
2285 	} else if (token == Opt_journal_path) {
2286 		char *journal_path;
2287 		struct inode *journal_inode;
2288 		struct path path;
2289 		int error;
2290 
2291 		if (is_remount) {
2292 			ext4_msg(sb, KERN_ERR,
2293 				 "Cannot specify journal on remount");
2294 			return -1;
2295 		}
2296 		journal_path = match_strdup(&args[0]);
2297 		if (!journal_path) {
2298 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2299 				"journal device string");
2300 			return -1;
2301 		}
2302 
2303 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2304 		if (error) {
2305 			ext4_msg(sb, KERN_ERR, "error: could not find "
2306 				"journal device path: error %d", error);
2307 			kfree(journal_path);
2308 			return -1;
2309 		}
2310 
2311 		journal_inode = d_inode(path.dentry);
2312 		if (!S_ISBLK(journal_inode->i_mode)) {
2313 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2314 				"is not a block device", journal_path);
2315 			path_put(&path);
2316 			kfree(journal_path);
2317 			return -1;
2318 		}
2319 
2320 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2321 		path_put(&path);
2322 		kfree(journal_path);
2323 	} else if (token == Opt_journal_ioprio) {
2324 		if (arg > 7) {
2325 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2326 				 " (must be 0-7)");
2327 			return -1;
2328 		}
2329 		*journal_ioprio =
2330 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2331 	} else if (token == Opt_test_dummy_encryption) {
2332 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2333 						      is_remount);
2334 	} else if (m->flags & MOPT_DATAJ) {
2335 		if (is_remount) {
2336 			if (!sbi->s_journal)
2337 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2338 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2339 				ext4_msg(sb, KERN_ERR,
2340 					 "Cannot change data mode on remount");
2341 				return -1;
2342 			}
2343 		} else {
2344 			clear_opt(sb, DATA_FLAGS);
2345 			sbi->s_mount_opt |= m->mount_opt;
2346 		}
2347 #ifdef CONFIG_QUOTA
2348 	} else if (m->flags & MOPT_QFMT) {
2349 		if (sb_any_quota_loaded(sb) &&
2350 		    sbi->s_jquota_fmt != m->mount_opt) {
2351 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2352 				 "quota options when quota turned on");
2353 			return -1;
2354 		}
2355 		if (ext4_has_feature_quota(sb)) {
2356 			ext4_msg(sb, KERN_INFO,
2357 				 "Quota format mount options ignored "
2358 				 "when QUOTA feature is enabled");
2359 			return 1;
2360 		}
2361 		sbi->s_jquota_fmt = m->mount_opt;
2362 #endif
2363 	} else if (token == Opt_dax || token == Opt_dax_always ||
2364 		   token == Opt_dax_inode || token == Opt_dax_never) {
2365 #ifdef CONFIG_FS_DAX
2366 		switch (token) {
2367 		case Opt_dax:
2368 		case Opt_dax_always:
2369 			if (is_remount &&
2370 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2371 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2372 			fail_dax_change_remount:
2373 				ext4_msg(sb, KERN_ERR, "can't change "
2374 					 "dax mount option while remounting");
2375 				return -1;
2376 			}
2377 			if (is_remount &&
2378 			    (test_opt(sb, DATA_FLAGS) ==
2379 			     EXT4_MOUNT_JOURNAL_DATA)) {
2380 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2381 					     "both data=journal and dax");
2382 				    return -1;
2383 			}
2384 			ext4_msg(sb, KERN_WARNING,
2385 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2386 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2387 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2388 			break;
2389 		case Opt_dax_never:
2390 			if (is_remount &&
2391 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2392 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2393 				goto fail_dax_change_remount;
2394 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2395 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2396 			break;
2397 		case Opt_dax_inode:
2398 			if (is_remount &&
2399 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2400 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2401 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2402 				goto fail_dax_change_remount;
2403 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2404 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2405 			/* Strictly for printing options */
2406 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2407 			break;
2408 		}
2409 #else
2410 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2411 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2412 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2413 		return -1;
2414 #endif
2415 	} else if (token == Opt_data_err_abort) {
2416 		sbi->s_mount_opt |= m->mount_opt;
2417 	} else if (token == Opt_data_err_ignore) {
2418 		sbi->s_mount_opt &= ~m->mount_opt;
2419 	} else {
2420 		if (!args->from)
2421 			arg = 1;
2422 		if (m->flags & MOPT_CLEAR)
2423 			arg = !arg;
2424 		else if (unlikely(!(m->flags & MOPT_SET))) {
2425 			ext4_msg(sb, KERN_WARNING,
2426 				 "buggy handling of option %s", opt);
2427 			WARN_ON(1);
2428 			return -1;
2429 		}
2430 		if (m->flags & MOPT_2) {
2431 			if (arg != 0)
2432 				sbi->s_mount_opt2 |= m->mount_opt;
2433 			else
2434 				sbi->s_mount_opt2 &= ~m->mount_opt;
2435 		} else {
2436 			if (arg != 0)
2437 				sbi->s_mount_opt |= m->mount_opt;
2438 			else
2439 				sbi->s_mount_opt &= ~m->mount_opt;
2440 		}
2441 	}
2442 	return 1;
2443 }
2444 
2445 static int parse_options(char *options, struct super_block *sb,
2446 			 unsigned long *journal_devnum,
2447 			 unsigned int *journal_ioprio,
2448 			 int is_remount)
2449 {
2450 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2451 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2452 	substring_t args[MAX_OPT_ARGS];
2453 	int token;
2454 
2455 	if (!options)
2456 		return 1;
2457 
2458 	while ((p = strsep(&options, ",")) != NULL) {
2459 		if (!*p)
2460 			continue;
2461 		/*
2462 		 * Initialize args struct so we know whether arg was
2463 		 * found; some options take optional arguments.
2464 		 */
2465 		args[0].to = args[0].from = NULL;
2466 		token = match_token(p, tokens, args);
2467 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2468 				     journal_ioprio, is_remount) < 0)
2469 			return 0;
2470 	}
2471 #ifdef CONFIG_QUOTA
2472 	/*
2473 	 * We do the test below only for project quotas. 'usrquota' and
2474 	 * 'grpquota' mount options are allowed even without quota feature
2475 	 * to support legacy quotas in quota files.
2476 	 */
2477 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2478 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2479 			 "Cannot enable project quota enforcement.");
2480 		return 0;
2481 	}
2482 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2483 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2484 	if (usr_qf_name || grp_qf_name) {
2485 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2486 			clear_opt(sb, USRQUOTA);
2487 
2488 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2489 			clear_opt(sb, GRPQUOTA);
2490 
2491 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2492 			ext4_msg(sb, KERN_ERR, "old and new quota "
2493 					"format mixing");
2494 			return 0;
2495 		}
2496 
2497 		if (!sbi->s_jquota_fmt) {
2498 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2499 					"not specified");
2500 			return 0;
2501 		}
2502 	}
2503 #endif
2504 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2505 		int blocksize =
2506 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2507 		if (blocksize < PAGE_SIZE)
2508 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2509 				 "experimental mount option 'dioread_nolock' "
2510 				 "for blocksize < PAGE_SIZE");
2511 	}
2512 	return 1;
2513 }
2514 
2515 static inline void ext4_show_quota_options(struct seq_file *seq,
2516 					   struct super_block *sb)
2517 {
2518 #if defined(CONFIG_QUOTA)
2519 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2520 	char *usr_qf_name, *grp_qf_name;
2521 
2522 	if (sbi->s_jquota_fmt) {
2523 		char *fmtname = "";
2524 
2525 		switch (sbi->s_jquota_fmt) {
2526 		case QFMT_VFS_OLD:
2527 			fmtname = "vfsold";
2528 			break;
2529 		case QFMT_VFS_V0:
2530 			fmtname = "vfsv0";
2531 			break;
2532 		case QFMT_VFS_V1:
2533 			fmtname = "vfsv1";
2534 			break;
2535 		}
2536 		seq_printf(seq, ",jqfmt=%s", fmtname);
2537 	}
2538 
2539 	rcu_read_lock();
2540 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2541 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2542 	if (usr_qf_name)
2543 		seq_show_option(seq, "usrjquota", usr_qf_name);
2544 	if (grp_qf_name)
2545 		seq_show_option(seq, "grpjquota", grp_qf_name);
2546 	rcu_read_unlock();
2547 #endif
2548 }
2549 
2550 static const char *token2str(int token)
2551 {
2552 	const struct match_token *t;
2553 
2554 	for (t = tokens; t->token != Opt_err; t++)
2555 		if (t->token == token && !strchr(t->pattern, '='))
2556 			break;
2557 	return t->pattern;
2558 }
2559 
2560 /*
2561  * Show an option if
2562  *  - it's set to a non-default value OR
2563  *  - if the per-sb default is different from the global default
2564  */
2565 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2566 			      int nodefs)
2567 {
2568 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2569 	struct ext4_super_block *es = sbi->s_es;
2570 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2571 	const struct mount_opts *m;
2572 	char sep = nodefs ? '\n' : ',';
2573 
2574 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2575 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2576 
2577 	if (sbi->s_sb_block != 1)
2578 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2579 
2580 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2581 		int want_set = m->flags & MOPT_SET;
2582 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2583 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2584 			continue;
2585 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2586 			continue; /* skip if same as the default */
2587 		if ((want_set &&
2588 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2589 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2590 			continue; /* select Opt_noFoo vs Opt_Foo */
2591 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2592 	}
2593 
2594 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2595 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2596 		SEQ_OPTS_PRINT("resuid=%u",
2597 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2598 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2599 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2600 		SEQ_OPTS_PRINT("resgid=%u",
2601 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2602 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2603 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2604 		SEQ_OPTS_PUTS("errors=remount-ro");
2605 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2606 		SEQ_OPTS_PUTS("errors=continue");
2607 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2608 		SEQ_OPTS_PUTS("errors=panic");
2609 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2610 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2611 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2612 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2613 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2614 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2615 	if (sb->s_flags & SB_I_VERSION)
2616 		SEQ_OPTS_PUTS("i_version");
2617 	if (nodefs || sbi->s_stripe)
2618 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2619 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2620 			(sbi->s_mount_opt ^ def_mount_opt)) {
2621 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2622 			SEQ_OPTS_PUTS("data=journal");
2623 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2624 			SEQ_OPTS_PUTS("data=ordered");
2625 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2626 			SEQ_OPTS_PUTS("data=writeback");
2627 	}
2628 	if (nodefs ||
2629 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2630 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2631 			       sbi->s_inode_readahead_blks);
2632 
2633 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2634 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2635 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2636 	if (nodefs || sbi->s_max_dir_size_kb)
2637 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2638 	if (test_opt(sb, DATA_ERR_ABORT))
2639 		SEQ_OPTS_PUTS("data_err=abort");
2640 
2641 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2642 
2643 	if (sb->s_flags & SB_INLINECRYPT)
2644 		SEQ_OPTS_PUTS("inlinecrypt");
2645 
2646 	if (test_opt(sb, DAX_ALWAYS)) {
2647 		if (IS_EXT2_SB(sb))
2648 			SEQ_OPTS_PUTS("dax");
2649 		else
2650 			SEQ_OPTS_PUTS("dax=always");
2651 	} else if (test_opt2(sb, DAX_NEVER)) {
2652 		SEQ_OPTS_PUTS("dax=never");
2653 	} else if (test_opt2(sb, DAX_INODE)) {
2654 		SEQ_OPTS_PUTS("dax=inode");
2655 	}
2656 
2657 	if (test_opt2(sb, JOURNAL_FAST_COMMIT))
2658 		SEQ_OPTS_PUTS("fast_commit");
2659 
2660 	ext4_show_quota_options(seq, sb);
2661 	return 0;
2662 }
2663 
2664 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2665 {
2666 	return _ext4_show_options(seq, root->d_sb, 0);
2667 }
2668 
2669 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2670 {
2671 	struct super_block *sb = seq->private;
2672 	int rc;
2673 
2674 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2675 	rc = _ext4_show_options(seq, sb, 1);
2676 	seq_puts(seq, "\n");
2677 	return rc;
2678 }
2679 
2680 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2681 			    int read_only)
2682 {
2683 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2684 	int err = 0;
2685 
2686 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2687 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2688 			 "forcing read-only mode");
2689 		err = -EROFS;
2690 		goto done;
2691 	}
2692 	if (read_only)
2693 		goto done;
2694 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2695 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2696 			 "running e2fsck is recommended");
2697 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2698 		ext4_msg(sb, KERN_WARNING,
2699 			 "warning: mounting fs with errors, "
2700 			 "running e2fsck is recommended");
2701 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2702 		 le16_to_cpu(es->s_mnt_count) >=
2703 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2704 		ext4_msg(sb, KERN_WARNING,
2705 			 "warning: maximal mount count reached, "
2706 			 "running e2fsck is recommended");
2707 	else if (le32_to_cpu(es->s_checkinterval) &&
2708 		 (ext4_get_tstamp(es, s_lastcheck) +
2709 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2710 		ext4_msg(sb, KERN_WARNING,
2711 			 "warning: checktime reached, "
2712 			 "running e2fsck is recommended");
2713 	if (!sbi->s_journal)
2714 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2715 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2716 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2717 	le16_add_cpu(&es->s_mnt_count, 1);
2718 	ext4_update_tstamp(es, s_mtime);
2719 	if (sbi->s_journal)
2720 		ext4_set_feature_journal_needs_recovery(sb);
2721 
2722 	err = ext4_commit_super(sb, 1);
2723 done:
2724 	if (test_opt(sb, DEBUG))
2725 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2726 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2727 			sb->s_blocksize,
2728 			sbi->s_groups_count,
2729 			EXT4_BLOCKS_PER_GROUP(sb),
2730 			EXT4_INODES_PER_GROUP(sb),
2731 			sbi->s_mount_opt, sbi->s_mount_opt2);
2732 
2733 	cleancache_init_fs(sb);
2734 	return err;
2735 }
2736 
2737 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2738 {
2739 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2740 	struct flex_groups **old_groups, **new_groups;
2741 	int size, i, j;
2742 
2743 	if (!sbi->s_log_groups_per_flex)
2744 		return 0;
2745 
2746 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2747 	if (size <= sbi->s_flex_groups_allocated)
2748 		return 0;
2749 
2750 	new_groups = kvzalloc(roundup_pow_of_two(size *
2751 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2752 	if (!new_groups) {
2753 		ext4_msg(sb, KERN_ERR,
2754 			 "not enough memory for %d flex group pointers", size);
2755 		return -ENOMEM;
2756 	}
2757 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2758 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2759 					 sizeof(struct flex_groups)),
2760 					 GFP_KERNEL);
2761 		if (!new_groups[i]) {
2762 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2763 				kvfree(new_groups[j]);
2764 			kvfree(new_groups);
2765 			ext4_msg(sb, KERN_ERR,
2766 				 "not enough memory for %d flex groups", size);
2767 			return -ENOMEM;
2768 		}
2769 	}
2770 	rcu_read_lock();
2771 	old_groups = rcu_dereference(sbi->s_flex_groups);
2772 	if (old_groups)
2773 		memcpy(new_groups, old_groups,
2774 		       (sbi->s_flex_groups_allocated *
2775 			sizeof(struct flex_groups *)));
2776 	rcu_read_unlock();
2777 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2778 	sbi->s_flex_groups_allocated = size;
2779 	if (old_groups)
2780 		ext4_kvfree_array_rcu(old_groups);
2781 	return 0;
2782 }
2783 
2784 static int ext4_fill_flex_info(struct super_block *sb)
2785 {
2786 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2787 	struct ext4_group_desc *gdp = NULL;
2788 	struct flex_groups *fg;
2789 	ext4_group_t flex_group;
2790 	int i, err;
2791 
2792 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2793 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2794 		sbi->s_log_groups_per_flex = 0;
2795 		return 1;
2796 	}
2797 
2798 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2799 	if (err)
2800 		goto failed;
2801 
2802 	for (i = 0; i < sbi->s_groups_count; i++) {
2803 		gdp = ext4_get_group_desc(sb, i, NULL);
2804 
2805 		flex_group = ext4_flex_group(sbi, i);
2806 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2807 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2808 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2809 			     &fg->free_clusters);
2810 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2811 	}
2812 
2813 	return 1;
2814 failed:
2815 	return 0;
2816 }
2817 
2818 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2819 				   struct ext4_group_desc *gdp)
2820 {
2821 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2822 	__u16 crc = 0;
2823 	__le32 le_group = cpu_to_le32(block_group);
2824 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2825 
2826 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2827 		/* Use new metadata_csum algorithm */
2828 		__u32 csum32;
2829 		__u16 dummy_csum = 0;
2830 
2831 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2832 				     sizeof(le_group));
2833 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2834 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2835 				     sizeof(dummy_csum));
2836 		offset += sizeof(dummy_csum);
2837 		if (offset < sbi->s_desc_size)
2838 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2839 					     sbi->s_desc_size - offset);
2840 
2841 		crc = csum32 & 0xFFFF;
2842 		goto out;
2843 	}
2844 
2845 	/* old crc16 code */
2846 	if (!ext4_has_feature_gdt_csum(sb))
2847 		return 0;
2848 
2849 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2850 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2851 	crc = crc16(crc, (__u8 *)gdp, offset);
2852 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2853 	/* for checksum of struct ext4_group_desc do the rest...*/
2854 	if (ext4_has_feature_64bit(sb) &&
2855 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2856 		crc = crc16(crc, (__u8 *)gdp + offset,
2857 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2858 				offset);
2859 
2860 out:
2861 	return cpu_to_le16(crc);
2862 }
2863 
2864 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2865 				struct ext4_group_desc *gdp)
2866 {
2867 	if (ext4_has_group_desc_csum(sb) &&
2868 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2869 		return 0;
2870 
2871 	return 1;
2872 }
2873 
2874 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2875 			      struct ext4_group_desc *gdp)
2876 {
2877 	if (!ext4_has_group_desc_csum(sb))
2878 		return;
2879 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2880 }
2881 
2882 /* Called at mount-time, super-block is locked */
2883 static int ext4_check_descriptors(struct super_block *sb,
2884 				  ext4_fsblk_t sb_block,
2885 				  ext4_group_t *first_not_zeroed)
2886 {
2887 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2888 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2889 	ext4_fsblk_t last_block;
2890 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2891 	ext4_fsblk_t block_bitmap;
2892 	ext4_fsblk_t inode_bitmap;
2893 	ext4_fsblk_t inode_table;
2894 	int flexbg_flag = 0;
2895 	ext4_group_t i, grp = sbi->s_groups_count;
2896 
2897 	if (ext4_has_feature_flex_bg(sb))
2898 		flexbg_flag = 1;
2899 
2900 	ext4_debug("Checking group descriptors");
2901 
2902 	for (i = 0; i < sbi->s_groups_count; i++) {
2903 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2904 
2905 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2906 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2907 		else
2908 			last_block = first_block +
2909 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2910 
2911 		if ((grp == sbi->s_groups_count) &&
2912 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2913 			grp = i;
2914 
2915 		block_bitmap = ext4_block_bitmap(sb, gdp);
2916 		if (block_bitmap == sb_block) {
2917 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2918 				 "Block bitmap for group %u overlaps "
2919 				 "superblock", i);
2920 			if (!sb_rdonly(sb))
2921 				return 0;
2922 		}
2923 		if (block_bitmap >= sb_block + 1 &&
2924 		    block_bitmap <= last_bg_block) {
2925 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2926 				 "Block bitmap for group %u overlaps "
2927 				 "block group descriptors", i);
2928 			if (!sb_rdonly(sb))
2929 				return 0;
2930 		}
2931 		if (block_bitmap < first_block || block_bitmap > last_block) {
2932 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2933 			       "Block bitmap for group %u not in group "
2934 			       "(block %llu)!", i, block_bitmap);
2935 			return 0;
2936 		}
2937 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2938 		if (inode_bitmap == sb_block) {
2939 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2940 				 "Inode bitmap for group %u overlaps "
2941 				 "superblock", i);
2942 			if (!sb_rdonly(sb))
2943 				return 0;
2944 		}
2945 		if (inode_bitmap >= sb_block + 1 &&
2946 		    inode_bitmap <= last_bg_block) {
2947 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2948 				 "Inode bitmap for group %u overlaps "
2949 				 "block group descriptors", i);
2950 			if (!sb_rdonly(sb))
2951 				return 0;
2952 		}
2953 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2954 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2955 			       "Inode bitmap for group %u not in group "
2956 			       "(block %llu)!", i, inode_bitmap);
2957 			return 0;
2958 		}
2959 		inode_table = ext4_inode_table(sb, gdp);
2960 		if (inode_table == sb_block) {
2961 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2962 				 "Inode table for group %u overlaps "
2963 				 "superblock", i);
2964 			if (!sb_rdonly(sb))
2965 				return 0;
2966 		}
2967 		if (inode_table >= sb_block + 1 &&
2968 		    inode_table <= last_bg_block) {
2969 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2970 				 "Inode table for group %u overlaps "
2971 				 "block group descriptors", i);
2972 			if (!sb_rdonly(sb))
2973 				return 0;
2974 		}
2975 		if (inode_table < first_block ||
2976 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2977 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2978 			       "Inode table for group %u not in group "
2979 			       "(block %llu)!", i, inode_table);
2980 			return 0;
2981 		}
2982 		ext4_lock_group(sb, i);
2983 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2984 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2985 				 "Checksum for group %u failed (%u!=%u)",
2986 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2987 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2988 			if (!sb_rdonly(sb)) {
2989 				ext4_unlock_group(sb, i);
2990 				return 0;
2991 			}
2992 		}
2993 		ext4_unlock_group(sb, i);
2994 		if (!flexbg_flag)
2995 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2996 	}
2997 	if (NULL != first_not_zeroed)
2998 		*first_not_zeroed = grp;
2999 	return 1;
3000 }
3001 
3002 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
3003  * the superblock) which were deleted from all directories, but held open by
3004  * a process at the time of a crash.  We walk the list and try to delete these
3005  * inodes at recovery time (only with a read-write filesystem).
3006  *
3007  * In order to keep the orphan inode chain consistent during traversal (in
3008  * case of crash during recovery), we link each inode into the superblock
3009  * orphan list_head and handle it the same way as an inode deletion during
3010  * normal operation (which journals the operations for us).
3011  *
3012  * We only do an iget() and an iput() on each inode, which is very safe if we
3013  * accidentally point at an in-use or already deleted inode.  The worst that
3014  * can happen in this case is that we get a "bit already cleared" message from
3015  * ext4_free_inode().  The only reason we would point at a wrong inode is if
3016  * e2fsck was run on this filesystem, and it must have already done the orphan
3017  * inode cleanup for us, so we can safely abort without any further action.
3018  */
3019 static void ext4_orphan_cleanup(struct super_block *sb,
3020 				struct ext4_super_block *es)
3021 {
3022 	unsigned int s_flags = sb->s_flags;
3023 	int ret, nr_orphans = 0, nr_truncates = 0;
3024 #ifdef CONFIG_QUOTA
3025 	int quota_update = 0;
3026 	int i;
3027 #endif
3028 	if (!es->s_last_orphan) {
3029 		jbd_debug(4, "no orphan inodes to clean up\n");
3030 		return;
3031 	}
3032 
3033 	if (bdev_read_only(sb->s_bdev)) {
3034 		ext4_msg(sb, KERN_ERR, "write access "
3035 			"unavailable, skipping orphan cleanup");
3036 		return;
3037 	}
3038 
3039 	/* Check if feature set would not allow a r/w mount */
3040 	if (!ext4_feature_set_ok(sb, 0)) {
3041 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
3042 			 "unknown ROCOMPAT features");
3043 		return;
3044 	}
3045 
3046 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3047 		/* don't clear list on RO mount w/ errors */
3048 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
3049 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
3050 				  "clearing orphan list.\n");
3051 			es->s_last_orphan = 0;
3052 		}
3053 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3054 		return;
3055 	}
3056 
3057 	if (s_flags & SB_RDONLY) {
3058 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
3059 		sb->s_flags &= ~SB_RDONLY;
3060 	}
3061 #ifdef CONFIG_QUOTA
3062 	/* Needed for iput() to work correctly and not trash data */
3063 	sb->s_flags |= SB_ACTIVE;
3064 
3065 	/*
3066 	 * Turn on quotas which were not enabled for read-only mounts if
3067 	 * filesystem has quota feature, so that they are updated correctly.
3068 	 */
3069 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
3070 		int ret = ext4_enable_quotas(sb);
3071 
3072 		if (!ret)
3073 			quota_update = 1;
3074 		else
3075 			ext4_msg(sb, KERN_ERR,
3076 				"Cannot turn on quotas: error %d", ret);
3077 	}
3078 
3079 	/* Turn on journaled quotas used for old sytle */
3080 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3081 		if (EXT4_SB(sb)->s_qf_names[i]) {
3082 			int ret = ext4_quota_on_mount(sb, i);
3083 
3084 			if (!ret)
3085 				quota_update = 1;
3086 			else
3087 				ext4_msg(sb, KERN_ERR,
3088 					"Cannot turn on journaled "
3089 					"quota: type %d: error %d", i, ret);
3090 		}
3091 	}
3092 #endif
3093 
3094 	while (es->s_last_orphan) {
3095 		struct inode *inode;
3096 
3097 		/*
3098 		 * We may have encountered an error during cleanup; if
3099 		 * so, skip the rest.
3100 		 */
3101 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3102 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3103 			es->s_last_orphan = 0;
3104 			break;
3105 		}
3106 
3107 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
3108 		if (IS_ERR(inode)) {
3109 			es->s_last_orphan = 0;
3110 			break;
3111 		}
3112 
3113 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
3114 		dquot_initialize(inode);
3115 		if (inode->i_nlink) {
3116 			if (test_opt(sb, DEBUG))
3117 				ext4_msg(sb, KERN_DEBUG,
3118 					"%s: truncating inode %lu to %lld bytes",
3119 					__func__, inode->i_ino, inode->i_size);
3120 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
3121 				  inode->i_ino, inode->i_size);
3122 			inode_lock(inode);
3123 			truncate_inode_pages(inode->i_mapping, inode->i_size);
3124 			ret = ext4_truncate(inode);
3125 			if (ret)
3126 				ext4_std_error(inode->i_sb, ret);
3127 			inode_unlock(inode);
3128 			nr_truncates++;
3129 		} else {
3130 			if (test_opt(sb, DEBUG))
3131 				ext4_msg(sb, KERN_DEBUG,
3132 					"%s: deleting unreferenced inode %lu",
3133 					__func__, inode->i_ino);
3134 			jbd_debug(2, "deleting unreferenced inode %lu\n",
3135 				  inode->i_ino);
3136 			nr_orphans++;
3137 		}
3138 		iput(inode);  /* The delete magic happens here! */
3139 	}
3140 
3141 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
3142 
3143 	if (nr_orphans)
3144 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
3145 		       PLURAL(nr_orphans));
3146 	if (nr_truncates)
3147 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
3148 		       PLURAL(nr_truncates));
3149 #ifdef CONFIG_QUOTA
3150 	/* Turn off quotas if they were enabled for orphan cleanup */
3151 	if (quota_update) {
3152 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3153 			if (sb_dqopt(sb)->files[i])
3154 				dquot_quota_off(sb, i);
3155 		}
3156 	}
3157 #endif
3158 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
3159 }
3160 
3161 /*
3162  * Maximal extent format file size.
3163  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3164  * extent format containers, within a sector_t, and within i_blocks
3165  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3166  * so that won't be a limiting factor.
3167  *
3168  * However there is other limiting factor. We do store extents in the form
3169  * of starting block and length, hence the resulting length of the extent
3170  * covering maximum file size must fit into on-disk format containers as
3171  * well. Given that length is always by 1 unit bigger than max unit (because
3172  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3173  *
3174  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3175  */
3176 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3177 {
3178 	loff_t res;
3179 	loff_t upper_limit = MAX_LFS_FILESIZE;
3180 
3181 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3182 
3183 	if (!has_huge_files) {
3184 		upper_limit = (1LL << 32) - 1;
3185 
3186 		/* total blocks in file system block size */
3187 		upper_limit >>= (blkbits - 9);
3188 		upper_limit <<= blkbits;
3189 	}
3190 
3191 	/*
3192 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3193 	 * by one fs block, so ee_len can cover the extent of maximum file
3194 	 * size
3195 	 */
3196 	res = (1LL << 32) - 1;
3197 	res <<= blkbits;
3198 
3199 	/* Sanity check against vm- & vfs- imposed limits */
3200 	if (res > upper_limit)
3201 		res = upper_limit;
3202 
3203 	return res;
3204 }
3205 
3206 /*
3207  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3208  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3209  * We need to be 1 filesystem block less than the 2^48 sector limit.
3210  */
3211 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3212 {
3213 	loff_t res = EXT4_NDIR_BLOCKS;
3214 	int meta_blocks;
3215 	loff_t upper_limit;
3216 	/* This is calculated to be the largest file size for a dense, block
3217 	 * mapped file such that the file's total number of 512-byte sectors,
3218 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3219 	 *
3220 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3221 	 * number of 512-byte sectors of the file.
3222 	 */
3223 
3224 	if (!has_huge_files) {
3225 		/*
3226 		 * !has_huge_files or implies that the inode i_block field
3227 		 * represents total file blocks in 2^32 512-byte sectors ==
3228 		 * size of vfs inode i_blocks * 8
3229 		 */
3230 		upper_limit = (1LL << 32) - 1;
3231 
3232 		/* total blocks in file system block size */
3233 		upper_limit >>= (bits - 9);
3234 
3235 	} else {
3236 		/*
3237 		 * We use 48 bit ext4_inode i_blocks
3238 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3239 		 * represent total number of blocks in
3240 		 * file system block size
3241 		 */
3242 		upper_limit = (1LL << 48) - 1;
3243 
3244 	}
3245 
3246 	/* indirect blocks */
3247 	meta_blocks = 1;
3248 	/* double indirect blocks */
3249 	meta_blocks += 1 + (1LL << (bits-2));
3250 	/* tripple indirect blocks */
3251 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3252 
3253 	upper_limit -= meta_blocks;
3254 	upper_limit <<= bits;
3255 
3256 	res += 1LL << (bits-2);
3257 	res += 1LL << (2*(bits-2));
3258 	res += 1LL << (3*(bits-2));
3259 	res <<= bits;
3260 	if (res > upper_limit)
3261 		res = upper_limit;
3262 
3263 	if (res > MAX_LFS_FILESIZE)
3264 		res = MAX_LFS_FILESIZE;
3265 
3266 	return res;
3267 }
3268 
3269 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3270 				   ext4_fsblk_t logical_sb_block, int nr)
3271 {
3272 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3273 	ext4_group_t bg, first_meta_bg;
3274 	int has_super = 0;
3275 
3276 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3277 
3278 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3279 		return logical_sb_block + nr + 1;
3280 	bg = sbi->s_desc_per_block * nr;
3281 	if (ext4_bg_has_super(sb, bg))
3282 		has_super = 1;
3283 
3284 	/*
3285 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3286 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3287 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3288 	 * compensate.
3289 	 */
3290 	if (sb->s_blocksize == 1024 && nr == 0 &&
3291 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3292 		has_super++;
3293 
3294 	return (has_super + ext4_group_first_block_no(sb, bg));
3295 }
3296 
3297 /**
3298  * ext4_get_stripe_size: Get the stripe size.
3299  * @sbi: In memory super block info
3300  *
3301  * If we have specified it via mount option, then
3302  * use the mount option value. If the value specified at mount time is
3303  * greater than the blocks per group use the super block value.
3304  * If the super block value is greater than blocks per group return 0.
3305  * Allocator needs it be less than blocks per group.
3306  *
3307  */
3308 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3309 {
3310 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3311 	unsigned long stripe_width =
3312 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3313 	int ret;
3314 
3315 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3316 		ret = sbi->s_stripe;
3317 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3318 		ret = stripe_width;
3319 	else if (stride && stride <= sbi->s_blocks_per_group)
3320 		ret = stride;
3321 	else
3322 		ret = 0;
3323 
3324 	/*
3325 	 * If the stripe width is 1, this makes no sense and
3326 	 * we set it to 0 to turn off stripe handling code.
3327 	 */
3328 	if (ret <= 1)
3329 		ret = 0;
3330 
3331 	return ret;
3332 }
3333 
3334 /*
3335  * Check whether this filesystem can be mounted based on
3336  * the features present and the RDONLY/RDWR mount requested.
3337  * Returns 1 if this filesystem can be mounted as requested,
3338  * 0 if it cannot be.
3339  */
3340 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3341 {
3342 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3343 		ext4_msg(sb, KERN_ERR,
3344 			"Couldn't mount because of "
3345 			"unsupported optional features (%x)",
3346 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3347 			~EXT4_FEATURE_INCOMPAT_SUPP));
3348 		return 0;
3349 	}
3350 
3351 #ifndef CONFIG_UNICODE
3352 	if (ext4_has_feature_casefold(sb)) {
3353 		ext4_msg(sb, KERN_ERR,
3354 			 "Filesystem with casefold feature cannot be "
3355 			 "mounted without CONFIG_UNICODE");
3356 		return 0;
3357 	}
3358 #endif
3359 
3360 	if (readonly)
3361 		return 1;
3362 
3363 	if (ext4_has_feature_readonly(sb)) {
3364 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3365 		sb->s_flags |= SB_RDONLY;
3366 		return 1;
3367 	}
3368 
3369 	/* Check that feature set is OK for a read-write mount */
3370 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3371 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3372 			 "unsupported optional features (%x)",
3373 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3374 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3375 		return 0;
3376 	}
3377 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3378 		ext4_msg(sb, KERN_ERR,
3379 			 "Can't support bigalloc feature without "
3380 			 "extents feature\n");
3381 		return 0;
3382 	}
3383 
3384 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3385 	if (!readonly && (ext4_has_feature_quota(sb) ||
3386 			  ext4_has_feature_project(sb))) {
3387 		ext4_msg(sb, KERN_ERR,
3388 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3389 		return 0;
3390 	}
3391 #endif  /* CONFIG_QUOTA */
3392 	return 1;
3393 }
3394 
3395 /*
3396  * This function is called once a day if we have errors logged
3397  * on the file system
3398  */
3399 static void print_daily_error_info(struct timer_list *t)
3400 {
3401 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3402 	struct super_block *sb = sbi->s_sb;
3403 	struct ext4_super_block *es = sbi->s_es;
3404 
3405 	if (es->s_error_count)
3406 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3407 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3408 			 le32_to_cpu(es->s_error_count));
3409 	if (es->s_first_error_time) {
3410 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3411 		       sb->s_id,
3412 		       ext4_get_tstamp(es, s_first_error_time),
3413 		       (int) sizeof(es->s_first_error_func),
3414 		       es->s_first_error_func,
3415 		       le32_to_cpu(es->s_first_error_line));
3416 		if (es->s_first_error_ino)
3417 			printk(KERN_CONT ": inode %u",
3418 			       le32_to_cpu(es->s_first_error_ino));
3419 		if (es->s_first_error_block)
3420 			printk(KERN_CONT ": block %llu", (unsigned long long)
3421 			       le64_to_cpu(es->s_first_error_block));
3422 		printk(KERN_CONT "\n");
3423 	}
3424 	if (es->s_last_error_time) {
3425 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3426 		       sb->s_id,
3427 		       ext4_get_tstamp(es, s_last_error_time),
3428 		       (int) sizeof(es->s_last_error_func),
3429 		       es->s_last_error_func,
3430 		       le32_to_cpu(es->s_last_error_line));
3431 		if (es->s_last_error_ino)
3432 			printk(KERN_CONT ": inode %u",
3433 			       le32_to_cpu(es->s_last_error_ino));
3434 		if (es->s_last_error_block)
3435 			printk(KERN_CONT ": block %llu", (unsigned long long)
3436 			       le64_to_cpu(es->s_last_error_block));
3437 		printk(KERN_CONT "\n");
3438 	}
3439 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3440 }
3441 
3442 /* Find next suitable group and run ext4_init_inode_table */
3443 static int ext4_run_li_request(struct ext4_li_request *elr)
3444 {
3445 	struct ext4_group_desc *gdp = NULL;
3446 	struct super_block *sb = elr->lr_super;
3447 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3448 	ext4_group_t group = elr->lr_next_group;
3449 	unsigned long timeout = 0;
3450 	unsigned int prefetch_ios = 0;
3451 	int ret = 0;
3452 
3453 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3454 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3455 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3456 		if (prefetch_ios)
3457 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3458 					      prefetch_ios);
3459 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3460 					    prefetch_ios);
3461 		if (group >= elr->lr_next_group) {
3462 			ret = 1;
3463 			if (elr->lr_first_not_zeroed != ngroups &&
3464 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3465 				elr->lr_next_group = elr->lr_first_not_zeroed;
3466 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3467 				ret = 0;
3468 			}
3469 		}
3470 		return ret;
3471 	}
3472 
3473 	for (; group < ngroups; group++) {
3474 		gdp = ext4_get_group_desc(sb, group, NULL);
3475 		if (!gdp) {
3476 			ret = 1;
3477 			break;
3478 		}
3479 
3480 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3481 			break;
3482 	}
3483 
3484 	if (group >= ngroups)
3485 		ret = 1;
3486 
3487 	if (!ret) {
3488 		timeout = jiffies;
3489 		ret = ext4_init_inode_table(sb, group,
3490 					    elr->lr_timeout ? 0 : 1);
3491 		trace_ext4_lazy_itable_init(sb, group);
3492 		if (elr->lr_timeout == 0) {
3493 			timeout = (jiffies - timeout) *
3494 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3495 			elr->lr_timeout = timeout;
3496 		}
3497 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3498 		elr->lr_next_group = group + 1;
3499 	}
3500 	return ret;
3501 }
3502 
3503 /*
3504  * Remove lr_request from the list_request and free the
3505  * request structure. Should be called with li_list_mtx held
3506  */
3507 static void ext4_remove_li_request(struct ext4_li_request *elr)
3508 {
3509 	if (!elr)
3510 		return;
3511 
3512 	list_del(&elr->lr_request);
3513 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3514 	kfree(elr);
3515 }
3516 
3517 static void ext4_unregister_li_request(struct super_block *sb)
3518 {
3519 	mutex_lock(&ext4_li_mtx);
3520 	if (!ext4_li_info) {
3521 		mutex_unlock(&ext4_li_mtx);
3522 		return;
3523 	}
3524 
3525 	mutex_lock(&ext4_li_info->li_list_mtx);
3526 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3527 	mutex_unlock(&ext4_li_info->li_list_mtx);
3528 	mutex_unlock(&ext4_li_mtx);
3529 }
3530 
3531 static struct task_struct *ext4_lazyinit_task;
3532 
3533 /*
3534  * This is the function where ext4lazyinit thread lives. It walks
3535  * through the request list searching for next scheduled filesystem.
3536  * When such a fs is found, run the lazy initialization request
3537  * (ext4_rn_li_request) and keep track of the time spend in this
3538  * function. Based on that time we compute next schedule time of
3539  * the request. When walking through the list is complete, compute
3540  * next waking time and put itself into sleep.
3541  */
3542 static int ext4_lazyinit_thread(void *arg)
3543 {
3544 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3545 	struct list_head *pos, *n;
3546 	struct ext4_li_request *elr;
3547 	unsigned long next_wakeup, cur;
3548 
3549 	BUG_ON(NULL == eli);
3550 
3551 cont_thread:
3552 	while (true) {
3553 		next_wakeup = MAX_JIFFY_OFFSET;
3554 
3555 		mutex_lock(&eli->li_list_mtx);
3556 		if (list_empty(&eli->li_request_list)) {
3557 			mutex_unlock(&eli->li_list_mtx);
3558 			goto exit_thread;
3559 		}
3560 		list_for_each_safe(pos, n, &eli->li_request_list) {
3561 			int err = 0;
3562 			int progress = 0;
3563 			elr = list_entry(pos, struct ext4_li_request,
3564 					 lr_request);
3565 
3566 			if (time_before(jiffies, elr->lr_next_sched)) {
3567 				if (time_before(elr->lr_next_sched, next_wakeup))
3568 					next_wakeup = elr->lr_next_sched;
3569 				continue;
3570 			}
3571 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3572 				if (sb_start_write_trylock(elr->lr_super)) {
3573 					progress = 1;
3574 					/*
3575 					 * We hold sb->s_umount, sb can not
3576 					 * be removed from the list, it is
3577 					 * now safe to drop li_list_mtx
3578 					 */
3579 					mutex_unlock(&eli->li_list_mtx);
3580 					err = ext4_run_li_request(elr);
3581 					sb_end_write(elr->lr_super);
3582 					mutex_lock(&eli->li_list_mtx);
3583 					n = pos->next;
3584 				}
3585 				up_read((&elr->lr_super->s_umount));
3586 			}
3587 			/* error, remove the lazy_init job */
3588 			if (err) {
3589 				ext4_remove_li_request(elr);
3590 				continue;
3591 			}
3592 			if (!progress) {
3593 				elr->lr_next_sched = jiffies +
3594 					(prandom_u32()
3595 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3596 			}
3597 			if (time_before(elr->lr_next_sched, next_wakeup))
3598 				next_wakeup = elr->lr_next_sched;
3599 		}
3600 		mutex_unlock(&eli->li_list_mtx);
3601 
3602 		try_to_freeze();
3603 
3604 		cur = jiffies;
3605 		if ((time_after_eq(cur, next_wakeup)) ||
3606 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3607 			cond_resched();
3608 			continue;
3609 		}
3610 
3611 		schedule_timeout_interruptible(next_wakeup - cur);
3612 
3613 		if (kthread_should_stop()) {
3614 			ext4_clear_request_list();
3615 			goto exit_thread;
3616 		}
3617 	}
3618 
3619 exit_thread:
3620 	/*
3621 	 * It looks like the request list is empty, but we need
3622 	 * to check it under the li_list_mtx lock, to prevent any
3623 	 * additions into it, and of course we should lock ext4_li_mtx
3624 	 * to atomically free the list and ext4_li_info, because at
3625 	 * this point another ext4 filesystem could be registering
3626 	 * new one.
3627 	 */
3628 	mutex_lock(&ext4_li_mtx);
3629 	mutex_lock(&eli->li_list_mtx);
3630 	if (!list_empty(&eli->li_request_list)) {
3631 		mutex_unlock(&eli->li_list_mtx);
3632 		mutex_unlock(&ext4_li_mtx);
3633 		goto cont_thread;
3634 	}
3635 	mutex_unlock(&eli->li_list_mtx);
3636 	kfree(ext4_li_info);
3637 	ext4_li_info = NULL;
3638 	mutex_unlock(&ext4_li_mtx);
3639 
3640 	return 0;
3641 }
3642 
3643 static void ext4_clear_request_list(void)
3644 {
3645 	struct list_head *pos, *n;
3646 	struct ext4_li_request *elr;
3647 
3648 	mutex_lock(&ext4_li_info->li_list_mtx);
3649 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3650 		elr = list_entry(pos, struct ext4_li_request,
3651 				 lr_request);
3652 		ext4_remove_li_request(elr);
3653 	}
3654 	mutex_unlock(&ext4_li_info->li_list_mtx);
3655 }
3656 
3657 static int ext4_run_lazyinit_thread(void)
3658 {
3659 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3660 					 ext4_li_info, "ext4lazyinit");
3661 	if (IS_ERR(ext4_lazyinit_task)) {
3662 		int err = PTR_ERR(ext4_lazyinit_task);
3663 		ext4_clear_request_list();
3664 		kfree(ext4_li_info);
3665 		ext4_li_info = NULL;
3666 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3667 				 "initialization thread\n",
3668 				 err);
3669 		return err;
3670 	}
3671 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3672 	return 0;
3673 }
3674 
3675 /*
3676  * Check whether it make sense to run itable init. thread or not.
3677  * If there is at least one uninitialized inode table, return
3678  * corresponding group number, else the loop goes through all
3679  * groups and return total number of groups.
3680  */
3681 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3682 {
3683 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3684 	struct ext4_group_desc *gdp = NULL;
3685 
3686 	if (!ext4_has_group_desc_csum(sb))
3687 		return ngroups;
3688 
3689 	for (group = 0; group < ngroups; group++) {
3690 		gdp = ext4_get_group_desc(sb, group, NULL);
3691 		if (!gdp)
3692 			continue;
3693 
3694 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3695 			break;
3696 	}
3697 
3698 	return group;
3699 }
3700 
3701 static int ext4_li_info_new(void)
3702 {
3703 	struct ext4_lazy_init *eli = NULL;
3704 
3705 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3706 	if (!eli)
3707 		return -ENOMEM;
3708 
3709 	INIT_LIST_HEAD(&eli->li_request_list);
3710 	mutex_init(&eli->li_list_mtx);
3711 
3712 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3713 
3714 	ext4_li_info = eli;
3715 
3716 	return 0;
3717 }
3718 
3719 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3720 					    ext4_group_t start)
3721 {
3722 	struct ext4_li_request *elr;
3723 
3724 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3725 	if (!elr)
3726 		return NULL;
3727 
3728 	elr->lr_super = sb;
3729 	elr->lr_first_not_zeroed = start;
3730 	if (test_opt(sb, PREFETCH_BLOCK_BITMAPS))
3731 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3732 	else {
3733 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3734 		elr->lr_next_group = start;
3735 	}
3736 
3737 	/*
3738 	 * Randomize first schedule time of the request to
3739 	 * spread the inode table initialization requests
3740 	 * better.
3741 	 */
3742 	elr->lr_next_sched = jiffies + (prandom_u32() %
3743 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3744 	return elr;
3745 }
3746 
3747 int ext4_register_li_request(struct super_block *sb,
3748 			     ext4_group_t first_not_zeroed)
3749 {
3750 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3751 	struct ext4_li_request *elr = NULL;
3752 	ext4_group_t ngroups = sbi->s_groups_count;
3753 	int ret = 0;
3754 
3755 	mutex_lock(&ext4_li_mtx);
3756 	if (sbi->s_li_request != NULL) {
3757 		/*
3758 		 * Reset timeout so it can be computed again, because
3759 		 * s_li_wait_mult might have changed.
3760 		 */
3761 		sbi->s_li_request->lr_timeout = 0;
3762 		goto out;
3763 	}
3764 
3765 	if (!test_opt(sb, PREFETCH_BLOCK_BITMAPS) &&
3766 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3767 	     !test_opt(sb, INIT_INODE_TABLE)))
3768 		goto out;
3769 
3770 	elr = ext4_li_request_new(sb, first_not_zeroed);
3771 	if (!elr) {
3772 		ret = -ENOMEM;
3773 		goto out;
3774 	}
3775 
3776 	if (NULL == ext4_li_info) {
3777 		ret = ext4_li_info_new();
3778 		if (ret)
3779 			goto out;
3780 	}
3781 
3782 	mutex_lock(&ext4_li_info->li_list_mtx);
3783 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3784 	mutex_unlock(&ext4_li_info->li_list_mtx);
3785 
3786 	sbi->s_li_request = elr;
3787 	/*
3788 	 * set elr to NULL here since it has been inserted to
3789 	 * the request_list and the removal and free of it is
3790 	 * handled by ext4_clear_request_list from now on.
3791 	 */
3792 	elr = NULL;
3793 
3794 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3795 		ret = ext4_run_lazyinit_thread();
3796 		if (ret)
3797 			goto out;
3798 	}
3799 out:
3800 	mutex_unlock(&ext4_li_mtx);
3801 	if (ret)
3802 		kfree(elr);
3803 	return ret;
3804 }
3805 
3806 /*
3807  * We do not need to lock anything since this is called on
3808  * module unload.
3809  */
3810 static void ext4_destroy_lazyinit_thread(void)
3811 {
3812 	/*
3813 	 * If thread exited earlier
3814 	 * there's nothing to be done.
3815 	 */
3816 	if (!ext4_li_info || !ext4_lazyinit_task)
3817 		return;
3818 
3819 	kthread_stop(ext4_lazyinit_task);
3820 }
3821 
3822 static int set_journal_csum_feature_set(struct super_block *sb)
3823 {
3824 	int ret = 1;
3825 	int compat, incompat;
3826 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3827 
3828 	if (ext4_has_metadata_csum(sb)) {
3829 		/* journal checksum v3 */
3830 		compat = 0;
3831 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3832 	} else {
3833 		/* journal checksum v1 */
3834 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3835 		incompat = 0;
3836 	}
3837 
3838 	jbd2_journal_clear_features(sbi->s_journal,
3839 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3840 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3841 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3842 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3843 		ret = jbd2_journal_set_features(sbi->s_journal,
3844 				compat, 0,
3845 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3846 				incompat);
3847 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3848 		ret = jbd2_journal_set_features(sbi->s_journal,
3849 				compat, 0,
3850 				incompat);
3851 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3852 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3853 	} else {
3854 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3855 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3856 	}
3857 
3858 	return ret;
3859 }
3860 
3861 /*
3862  * Note: calculating the overhead so we can be compatible with
3863  * historical BSD practice is quite difficult in the face of
3864  * clusters/bigalloc.  This is because multiple metadata blocks from
3865  * different block group can end up in the same allocation cluster.
3866  * Calculating the exact overhead in the face of clustered allocation
3867  * requires either O(all block bitmaps) in memory or O(number of block
3868  * groups**2) in time.  We will still calculate the superblock for
3869  * older file systems --- and if we come across with a bigalloc file
3870  * system with zero in s_overhead_clusters the estimate will be close to
3871  * correct especially for very large cluster sizes --- but for newer
3872  * file systems, it's better to calculate this figure once at mkfs
3873  * time, and store it in the superblock.  If the superblock value is
3874  * present (even for non-bigalloc file systems), we will use it.
3875  */
3876 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3877 			  char *buf)
3878 {
3879 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3880 	struct ext4_group_desc	*gdp;
3881 	ext4_fsblk_t		first_block, last_block, b;
3882 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3883 	int			s, j, count = 0;
3884 
3885 	if (!ext4_has_feature_bigalloc(sb))
3886 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3887 			sbi->s_itb_per_group + 2);
3888 
3889 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3890 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3891 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3892 	for (i = 0; i < ngroups; i++) {
3893 		gdp = ext4_get_group_desc(sb, i, NULL);
3894 		b = ext4_block_bitmap(sb, gdp);
3895 		if (b >= first_block && b <= last_block) {
3896 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3897 			count++;
3898 		}
3899 		b = ext4_inode_bitmap(sb, gdp);
3900 		if (b >= first_block && b <= last_block) {
3901 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3902 			count++;
3903 		}
3904 		b = ext4_inode_table(sb, gdp);
3905 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3906 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3907 				int c = EXT4_B2C(sbi, b - first_block);
3908 				ext4_set_bit(c, buf);
3909 				count++;
3910 			}
3911 		if (i != grp)
3912 			continue;
3913 		s = 0;
3914 		if (ext4_bg_has_super(sb, grp)) {
3915 			ext4_set_bit(s++, buf);
3916 			count++;
3917 		}
3918 		j = ext4_bg_num_gdb(sb, grp);
3919 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3920 			ext4_error(sb, "Invalid number of block group "
3921 				   "descriptor blocks: %d", j);
3922 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3923 		}
3924 		count += j;
3925 		for (; j > 0; j--)
3926 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3927 	}
3928 	if (!count)
3929 		return 0;
3930 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3931 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3932 }
3933 
3934 /*
3935  * Compute the overhead and stash it in sbi->s_overhead
3936  */
3937 int ext4_calculate_overhead(struct super_block *sb)
3938 {
3939 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3940 	struct ext4_super_block *es = sbi->s_es;
3941 	struct inode *j_inode;
3942 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3943 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3944 	ext4_fsblk_t overhead = 0;
3945 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3946 
3947 	if (!buf)
3948 		return -ENOMEM;
3949 
3950 	/*
3951 	 * Compute the overhead (FS structures).  This is constant
3952 	 * for a given filesystem unless the number of block groups
3953 	 * changes so we cache the previous value until it does.
3954 	 */
3955 
3956 	/*
3957 	 * All of the blocks before first_data_block are overhead
3958 	 */
3959 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3960 
3961 	/*
3962 	 * Add the overhead found in each block group
3963 	 */
3964 	for (i = 0; i < ngroups; i++) {
3965 		int blks;
3966 
3967 		blks = count_overhead(sb, i, buf);
3968 		overhead += blks;
3969 		if (blks)
3970 			memset(buf, 0, PAGE_SIZE);
3971 		cond_resched();
3972 	}
3973 
3974 	/*
3975 	 * Add the internal journal blocks whether the journal has been
3976 	 * loaded or not
3977 	 */
3978 	if (sbi->s_journal && !sbi->s_journal_bdev)
3979 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3980 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3981 		/* j_inum for internal journal is non-zero */
3982 		j_inode = ext4_get_journal_inode(sb, j_inum);
3983 		if (j_inode) {
3984 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3985 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3986 			iput(j_inode);
3987 		} else {
3988 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3989 		}
3990 	}
3991 	sbi->s_overhead = overhead;
3992 	smp_wmb();
3993 	free_page((unsigned long) buf);
3994 	return 0;
3995 }
3996 
3997 static void ext4_set_resv_clusters(struct super_block *sb)
3998 {
3999 	ext4_fsblk_t resv_clusters;
4000 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4001 
4002 	/*
4003 	 * There's no need to reserve anything when we aren't using extents.
4004 	 * The space estimates are exact, there are no unwritten extents,
4005 	 * hole punching doesn't need new metadata... This is needed especially
4006 	 * to keep ext2/3 backward compatibility.
4007 	 */
4008 	if (!ext4_has_feature_extents(sb))
4009 		return;
4010 	/*
4011 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
4012 	 * This should cover the situations where we can not afford to run
4013 	 * out of space like for example punch hole, or converting
4014 	 * unwritten extents in delalloc path. In most cases such
4015 	 * allocation would require 1, or 2 blocks, higher numbers are
4016 	 * very rare.
4017 	 */
4018 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4019 			 sbi->s_cluster_bits);
4020 
4021 	do_div(resv_clusters, 50);
4022 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4023 
4024 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4025 }
4026 
4027 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
4028 {
4029 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
4030 	char *orig_data = kstrdup(data, GFP_KERNEL);
4031 	struct buffer_head *bh, **group_desc;
4032 	struct ext4_super_block *es = NULL;
4033 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4034 	struct flex_groups **flex_groups;
4035 	ext4_fsblk_t block;
4036 	ext4_fsblk_t sb_block = get_sb_block(&data);
4037 	ext4_fsblk_t logical_sb_block;
4038 	unsigned long offset = 0;
4039 	unsigned long journal_devnum = 0;
4040 	unsigned long def_mount_opts;
4041 	struct inode *root;
4042 	const char *descr;
4043 	int ret = -ENOMEM;
4044 	int blocksize, clustersize;
4045 	unsigned int db_count;
4046 	unsigned int i;
4047 	int needs_recovery, has_huge_files;
4048 	__u64 blocks_count;
4049 	int err = 0;
4050 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4051 	ext4_group_t first_not_zeroed;
4052 
4053 	if ((data && !orig_data) || !sbi)
4054 		goto out_free_base;
4055 
4056 	sbi->s_daxdev = dax_dev;
4057 	sbi->s_blockgroup_lock =
4058 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4059 	if (!sbi->s_blockgroup_lock)
4060 		goto out_free_base;
4061 
4062 	sb->s_fs_info = sbi;
4063 	sbi->s_sb = sb;
4064 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4065 	sbi->s_sb_block = sb_block;
4066 	if (sb->s_bdev->bd_part)
4067 		sbi->s_sectors_written_start =
4068 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
4069 
4070 	/* Cleanup superblock name */
4071 	strreplace(sb->s_id, '/', '!');
4072 
4073 	/* -EINVAL is default */
4074 	ret = -EINVAL;
4075 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4076 	if (!blocksize) {
4077 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4078 		goto out_fail;
4079 	}
4080 
4081 	/*
4082 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4083 	 * block sizes.  We need to calculate the offset from buffer start.
4084 	 */
4085 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4086 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4087 		offset = do_div(logical_sb_block, blocksize);
4088 	} else {
4089 		logical_sb_block = sb_block;
4090 	}
4091 
4092 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4093 	if (IS_ERR(bh)) {
4094 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4095 		ret = PTR_ERR(bh);
4096 		bh = NULL;
4097 		goto out_fail;
4098 	}
4099 	/*
4100 	 * Note: s_es must be initialized as soon as possible because
4101 	 *       some ext4 macro-instructions depend on its value
4102 	 */
4103 	es = (struct ext4_super_block *) (bh->b_data + offset);
4104 	sbi->s_es = es;
4105 	sb->s_magic = le16_to_cpu(es->s_magic);
4106 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4107 		goto cantfind_ext4;
4108 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4109 
4110 	/* Warn if metadata_csum and gdt_csum are both set. */
4111 	if (ext4_has_feature_metadata_csum(sb) &&
4112 	    ext4_has_feature_gdt_csum(sb))
4113 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4114 			     "redundant flags; please run fsck.");
4115 
4116 	/* Check for a known checksum algorithm */
4117 	if (!ext4_verify_csum_type(sb, es)) {
4118 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4119 			 "unknown checksum algorithm.");
4120 		silent = 1;
4121 		goto cantfind_ext4;
4122 	}
4123 
4124 	/* Load the checksum driver */
4125 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4126 	if (IS_ERR(sbi->s_chksum_driver)) {
4127 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4128 		ret = PTR_ERR(sbi->s_chksum_driver);
4129 		sbi->s_chksum_driver = NULL;
4130 		goto failed_mount;
4131 	}
4132 
4133 	/* Check superblock checksum */
4134 	if (!ext4_superblock_csum_verify(sb, es)) {
4135 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4136 			 "invalid superblock checksum.  Run e2fsck?");
4137 		silent = 1;
4138 		ret = -EFSBADCRC;
4139 		goto cantfind_ext4;
4140 	}
4141 
4142 	/* Precompute checksum seed for all metadata */
4143 	if (ext4_has_feature_csum_seed(sb))
4144 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4145 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4146 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4147 					       sizeof(es->s_uuid));
4148 
4149 	/* Set defaults before we parse the mount options */
4150 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4151 	set_opt(sb, INIT_INODE_TABLE);
4152 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4153 		set_opt(sb, DEBUG);
4154 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4155 		set_opt(sb, GRPID);
4156 	if (def_mount_opts & EXT4_DEFM_UID16)
4157 		set_opt(sb, NO_UID32);
4158 	/* xattr user namespace & acls are now defaulted on */
4159 	set_opt(sb, XATTR_USER);
4160 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4161 	set_opt(sb, POSIX_ACL);
4162 #endif
4163 	if (ext4_has_feature_fast_commit(sb))
4164 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4165 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4166 	if (ext4_has_metadata_csum(sb))
4167 		set_opt(sb, JOURNAL_CHECKSUM);
4168 
4169 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4170 		set_opt(sb, JOURNAL_DATA);
4171 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4172 		set_opt(sb, ORDERED_DATA);
4173 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4174 		set_opt(sb, WRITEBACK_DATA);
4175 
4176 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4177 		set_opt(sb, ERRORS_PANIC);
4178 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4179 		set_opt(sb, ERRORS_CONT);
4180 	else
4181 		set_opt(sb, ERRORS_RO);
4182 	/* block_validity enabled by default; disable with noblock_validity */
4183 	set_opt(sb, BLOCK_VALIDITY);
4184 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4185 		set_opt(sb, DISCARD);
4186 
4187 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4188 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4189 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4190 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4191 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4192 
4193 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4194 		set_opt(sb, BARRIER);
4195 
4196 	/*
4197 	 * enable delayed allocation by default
4198 	 * Use -o nodelalloc to turn it off
4199 	 */
4200 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4201 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4202 		set_opt(sb, DELALLOC);
4203 
4204 	/*
4205 	 * set default s_li_wait_mult for lazyinit, for the case there is
4206 	 * no mount option specified.
4207 	 */
4208 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4209 
4210 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4211 
4212 	if (blocksize == PAGE_SIZE)
4213 		set_opt(sb, DIOREAD_NOLOCK);
4214 
4215 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
4216 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
4217 		ext4_msg(sb, KERN_ERR,
4218 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
4219 			 blocksize, le32_to_cpu(es->s_log_block_size));
4220 		goto failed_mount;
4221 	}
4222 
4223 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4224 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4225 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4226 	} else {
4227 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4228 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4229 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4230 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4231 				 sbi->s_first_ino);
4232 			goto failed_mount;
4233 		}
4234 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4235 		    (!is_power_of_2(sbi->s_inode_size)) ||
4236 		    (sbi->s_inode_size > blocksize)) {
4237 			ext4_msg(sb, KERN_ERR,
4238 			       "unsupported inode size: %d",
4239 			       sbi->s_inode_size);
4240 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4241 			goto failed_mount;
4242 		}
4243 		/*
4244 		 * i_atime_extra is the last extra field available for
4245 		 * [acm]times in struct ext4_inode. Checking for that
4246 		 * field should suffice to ensure we have extra space
4247 		 * for all three.
4248 		 */
4249 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4250 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4251 			sb->s_time_gran = 1;
4252 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4253 		} else {
4254 			sb->s_time_gran = NSEC_PER_SEC;
4255 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4256 		}
4257 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4258 	}
4259 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4260 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4261 			EXT4_GOOD_OLD_INODE_SIZE;
4262 		if (ext4_has_feature_extra_isize(sb)) {
4263 			unsigned v, max = (sbi->s_inode_size -
4264 					   EXT4_GOOD_OLD_INODE_SIZE);
4265 
4266 			v = le16_to_cpu(es->s_want_extra_isize);
4267 			if (v > max) {
4268 				ext4_msg(sb, KERN_ERR,
4269 					 "bad s_want_extra_isize: %d", v);
4270 				goto failed_mount;
4271 			}
4272 			if (sbi->s_want_extra_isize < v)
4273 				sbi->s_want_extra_isize = v;
4274 
4275 			v = le16_to_cpu(es->s_min_extra_isize);
4276 			if (v > max) {
4277 				ext4_msg(sb, KERN_ERR,
4278 					 "bad s_min_extra_isize: %d", v);
4279 				goto failed_mount;
4280 			}
4281 			if (sbi->s_want_extra_isize < v)
4282 				sbi->s_want_extra_isize = v;
4283 		}
4284 	}
4285 
4286 	if (sbi->s_es->s_mount_opts[0]) {
4287 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4288 					      sizeof(sbi->s_es->s_mount_opts),
4289 					      GFP_KERNEL);
4290 		if (!s_mount_opts)
4291 			goto failed_mount;
4292 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
4293 				   &journal_ioprio, 0)) {
4294 			ext4_msg(sb, KERN_WARNING,
4295 				 "failed to parse options in superblock: %s",
4296 				 s_mount_opts);
4297 		}
4298 		kfree(s_mount_opts);
4299 	}
4300 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4301 	if (!parse_options((char *) data, sb, &journal_devnum,
4302 			   &journal_ioprio, 0))
4303 		goto failed_mount;
4304 
4305 #ifdef CONFIG_UNICODE
4306 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
4307 		const struct ext4_sb_encodings *encoding_info;
4308 		struct unicode_map *encoding;
4309 		__u16 encoding_flags;
4310 
4311 		if (ext4_has_feature_encrypt(sb)) {
4312 			ext4_msg(sb, KERN_ERR,
4313 				 "Can't mount with encoding and encryption");
4314 			goto failed_mount;
4315 		}
4316 
4317 		if (ext4_sb_read_encoding(es, &encoding_info,
4318 					  &encoding_flags)) {
4319 			ext4_msg(sb, KERN_ERR,
4320 				 "Encoding requested by superblock is unknown");
4321 			goto failed_mount;
4322 		}
4323 
4324 		encoding = utf8_load(encoding_info->version);
4325 		if (IS_ERR(encoding)) {
4326 			ext4_msg(sb, KERN_ERR,
4327 				 "can't mount with superblock charset: %s-%s "
4328 				 "not supported by the kernel. flags: 0x%x.",
4329 				 encoding_info->name, encoding_info->version,
4330 				 encoding_flags);
4331 			goto failed_mount;
4332 		}
4333 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4334 			 "%s-%s with flags 0x%hx", encoding_info->name,
4335 			 encoding_info->version?:"\b", encoding_flags);
4336 
4337 		sbi->s_encoding = encoding;
4338 		sbi->s_encoding_flags = encoding_flags;
4339 	}
4340 #endif
4341 
4342 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4343 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!\n");
4344 		/* can't mount with both data=journal and dioread_nolock. */
4345 		clear_opt(sb, DIOREAD_NOLOCK);
4346 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4347 			ext4_msg(sb, KERN_ERR, "can't mount with "
4348 				 "both data=journal and delalloc");
4349 			goto failed_mount;
4350 		}
4351 		if (test_opt(sb, DAX_ALWAYS)) {
4352 			ext4_msg(sb, KERN_ERR, "can't mount with "
4353 				 "both data=journal and dax");
4354 			goto failed_mount;
4355 		}
4356 		if (ext4_has_feature_encrypt(sb)) {
4357 			ext4_msg(sb, KERN_WARNING,
4358 				 "encrypted files will use data=ordered "
4359 				 "instead of data journaling mode");
4360 		}
4361 		if (test_opt(sb, DELALLOC))
4362 			clear_opt(sb, DELALLOC);
4363 	} else {
4364 		sb->s_iflags |= SB_I_CGROUPWB;
4365 	}
4366 
4367 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4368 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4369 
4370 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4371 	    (ext4_has_compat_features(sb) ||
4372 	     ext4_has_ro_compat_features(sb) ||
4373 	     ext4_has_incompat_features(sb)))
4374 		ext4_msg(sb, KERN_WARNING,
4375 		       "feature flags set on rev 0 fs, "
4376 		       "running e2fsck is recommended");
4377 
4378 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4379 		set_opt2(sb, HURD_COMPAT);
4380 		if (ext4_has_feature_64bit(sb)) {
4381 			ext4_msg(sb, KERN_ERR,
4382 				 "The Hurd can't support 64-bit file systems");
4383 			goto failed_mount;
4384 		}
4385 
4386 		/*
4387 		 * ea_inode feature uses l_i_version field which is not
4388 		 * available in HURD_COMPAT mode.
4389 		 */
4390 		if (ext4_has_feature_ea_inode(sb)) {
4391 			ext4_msg(sb, KERN_ERR,
4392 				 "ea_inode feature is not supported for Hurd");
4393 			goto failed_mount;
4394 		}
4395 	}
4396 
4397 	if (IS_EXT2_SB(sb)) {
4398 		if (ext2_feature_set_ok(sb))
4399 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4400 				 "using the ext4 subsystem");
4401 		else {
4402 			/*
4403 			 * If we're probing be silent, if this looks like
4404 			 * it's actually an ext[34] filesystem.
4405 			 */
4406 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4407 				goto failed_mount;
4408 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4409 				 "to feature incompatibilities");
4410 			goto failed_mount;
4411 		}
4412 	}
4413 
4414 	if (IS_EXT3_SB(sb)) {
4415 		if (ext3_feature_set_ok(sb))
4416 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4417 				 "using the ext4 subsystem");
4418 		else {
4419 			/*
4420 			 * If we're probing be silent, if this looks like
4421 			 * it's actually an ext4 filesystem.
4422 			 */
4423 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4424 				goto failed_mount;
4425 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4426 				 "to feature incompatibilities");
4427 			goto failed_mount;
4428 		}
4429 	}
4430 
4431 	/*
4432 	 * Check feature flags regardless of the revision level, since we
4433 	 * previously didn't change the revision level when setting the flags,
4434 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4435 	 */
4436 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4437 		goto failed_mount;
4438 
4439 	if (le32_to_cpu(es->s_log_block_size) >
4440 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4441 		ext4_msg(sb, KERN_ERR,
4442 			 "Invalid log block size: %u",
4443 			 le32_to_cpu(es->s_log_block_size));
4444 		goto failed_mount;
4445 	}
4446 	if (le32_to_cpu(es->s_log_cluster_size) >
4447 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4448 		ext4_msg(sb, KERN_ERR,
4449 			 "Invalid log cluster size: %u",
4450 			 le32_to_cpu(es->s_log_cluster_size));
4451 		goto failed_mount;
4452 	}
4453 
4454 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4455 		ext4_msg(sb, KERN_ERR,
4456 			 "Number of reserved GDT blocks insanely large: %d",
4457 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4458 		goto failed_mount;
4459 	}
4460 
4461 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4462 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4463 
4464 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4465 		if (ext4_has_feature_inline_data(sb)) {
4466 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4467 					" that may contain inline data");
4468 			goto failed_mount;
4469 		}
4470 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4471 			ext4_msg(sb, KERN_ERR,
4472 				"DAX unsupported by block device.");
4473 			goto failed_mount;
4474 		}
4475 	}
4476 
4477 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4478 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4479 			 es->s_encryption_level);
4480 		goto failed_mount;
4481 	}
4482 
4483 	if (sb->s_blocksize != blocksize) {
4484 		/* Validate the filesystem blocksize */
4485 		if (!sb_set_blocksize(sb, blocksize)) {
4486 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4487 					blocksize);
4488 			goto failed_mount;
4489 		}
4490 
4491 		brelse(bh);
4492 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4493 		offset = do_div(logical_sb_block, blocksize);
4494 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4495 		if (IS_ERR(bh)) {
4496 			ext4_msg(sb, KERN_ERR,
4497 			       "Can't read superblock on 2nd try");
4498 			ret = PTR_ERR(bh);
4499 			bh = NULL;
4500 			goto failed_mount;
4501 		}
4502 		es = (struct ext4_super_block *)(bh->b_data + offset);
4503 		sbi->s_es = es;
4504 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4505 			ext4_msg(sb, KERN_ERR,
4506 			       "Magic mismatch, very weird!");
4507 			goto failed_mount;
4508 		}
4509 	}
4510 
4511 	has_huge_files = ext4_has_feature_huge_file(sb);
4512 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4513 						      has_huge_files);
4514 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4515 
4516 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4517 	if (ext4_has_feature_64bit(sb)) {
4518 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4519 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4520 		    !is_power_of_2(sbi->s_desc_size)) {
4521 			ext4_msg(sb, KERN_ERR,
4522 			       "unsupported descriptor size %lu",
4523 			       sbi->s_desc_size);
4524 			goto failed_mount;
4525 		}
4526 	} else
4527 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4528 
4529 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4530 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4531 
4532 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4533 	if (sbi->s_inodes_per_block == 0)
4534 		goto cantfind_ext4;
4535 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4536 	    sbi->s_inodes_per_group > blocksize * 8) {
4537 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4538 			 sbi->s_inodes_per_group);
4539 		goto failed_mount;
4540 	}
4541 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4542 					sbi->s_inodes_per_block;
4543 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4544 	sbi->s_sbh = bh;
4545 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4546 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4547 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4548 
4549 	for (i = 0; i < 4; i++)
4550 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4551 	sbi->s_def_hash_version = es->s_def_hash_version;
4552 	if (ext4_has_feature_dir_index(sb)) {
4553 		i = le32_to_cpu(es->s_flags);
4554 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4555 			sbi->s_hash_unsigned = 3;
4556 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4557 #ifdef __CHAR_UNSIGNED__
4558 			if (!sb_rdonly(sb))
4559 				es->s_flags |=
4560 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4561 			sbi->s_hash_unsigned = 3;
4562 #else
4563 			if (!sb_rdonly(sb))
4564 				es->s_flags |=
4565 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4566 #endif
4567 		}
4568 	}
4569 
4570 	/* Handle clustersize */
4571 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4572 	if (ext4_has_feature_bigalloc(sb)) {
4573 		if (clustersize < blocksize) {
4574 			ext4_msg(sb, KERN_ERR,
4575 				 "cluster size (%d) smaller than "
4576 				 "block size (%d)", clustersize, blocksize);
4577 			goto failed_mount;
4578 		}
4579 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4580 			le32_to_cpu(es->s_log_block_size);
4581 		sbi->s_clusters_per_group =
4582 			le32_to_cpu(es->s_clusters_per_group);
4583 		if (sbi->s_clusters_per_group > blocksize * 8) {
4584 			ext4_msg(sb, KERN_ERR,
4585 				 "#clusters per group too big: %lu",
4586 				 sbi->s_clusters_per_group);
4587 			goto failed_mount;
4588 		}
4589 		if (sbi->s_blocks_per_group !=
4590 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4591 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4592 				 "clusters per group (%lu) inconsistent",
4593 				 sbi->s_blocks_per_group,
4594 				 sbi->s_clusters_per_group);
4595 			goto failed_mount;
4596 		}
4597 	} else {
4598 		if (clustersize != blocksize) {
4599 			ext4_msg(sb, KERN_ERR,
4600 				 "fragment/cluster size (%d) != "
4601 				 "block size (%d)", clustersize, blocksize);
4602 			goto failed_mount;
4603 		}
4604 		if (sbi->s_blocks_per_group > blocksize * 8) {
4605 			ext4_msg(sb, KERN_ERR,
4606 				 "#blocks per group too big: %lu",
4607 				 sbi->s_blocks_per_group);
4608 			goto failed_mount;
4609 		}
4610 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4611 		sbi->s_cluster_bits = 0;
4612 	}
4613 	sbi->s_cluster_ratio = clustersize / blocksize;
4614 
4615 	/* Do we have standard group size of clustersize * 8 blocks ? */
4616 	if (sbi->s_blocks_per_group == clustersize << 3)
4617 		set_opt2(sb, STD_GROUP_SIZE);
4618 
4619 	/*
4620 	 * Test whether we have more sectors than will fit in sector_t,
4621 	 * and whether the max offset is addressable by the page cache.
4622 	 */
4623 	err = generic_check_addressable(sb->s_blocksize_bits,
4624 					ext4_blocks_count(es));
4625 	if (err) {
4626 		ext4_msg(sb, KERN_ERR, "filesystem"
4627 			 " too large to mount safely on this system");
4628 		goto failed_mount;
4629 	}
4630 
4631 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4632 		goto cantfind_ext4;
4633 
4634 	/* check blocks count against device size */
4635 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4636 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4637 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4638 		       "exceeds size of device (%llu blocks)",
4639 		       ext4_blocks_count(es), blocks_count);
4640 		goto failed_mount;
4641 	}
4642 
4643 	/*
4644 	 * It makes no sense for the first data block to be beyond the end
4645 	 * of the filesystem.
4646 	 */
4647 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4648 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4649 			 "block %u is beyond end of filesystem (%llu)",
4650 			 le32_to_cpu(es->s_first_data_block),
4651 			 ext4_blocks_count(es));
4652 		goto failed_mount;
4653 	}
4654 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4655 	    (sbi->s_cluster_ratio == 1)) {
4656 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4657 			 "block is 0 with a 1k block and cluster size");
4658 		goto failed_mount;
4659 	}
4660 
4661 	blocks_count = (ext4_blocks_count(es) -
4662 			le32_to_cpu(es->s_first_data_block) +
4663 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4664 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4665 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4666 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4667 		       "(block count %llu, first data block %u, "
4668 		       "blocks per group %lu)", blocks_count,
4669 		       ext4_blocks_count(es),
4670 		       le32_to_cpu(es->s_first_data_block),
4671 		       EXT4_BLOCKS_PER_GROUP(sb));
4672 		goto failed_mount;
4673 	}
4674 	sbi->s_groups_count = blocks_count;
4675 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4676 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4677 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4678 	    le32_to_cpu(es->s_inodes_count)) {
4679 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4680 			 le32_to_cpu(es->s_inodes_count),
4681 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4682 		ret = -EINVAL;
4683 		goto failed_mount;
4684 	}
4685 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4686 		   EXT4_DESC_PER_BLOCK(sb);
4687 	if (ext4_has_feature_meta_bg(sb)) {
4688 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4689 			ext4_msg(sb, KERN_WARNING,
4690 				 "first meta block group too large: %u "
4691 				 "(group descriptor block count %u)",
4692 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4693 			goto failed_mount;
4694 		}
4695 	}
4696 	rcu_assign_pointer(sbi->s_group_desc,
4697 			   kvmalloc_array(db_count,
4698 					  sizeof(struct buffer_head *),
4699 					  GFP_KERNEL));
4700 	if (sbi->s_group_desc == NULL) {
4701 		ext4_msg(sb, KERN_ERR, "not enough memory");
4702 		ret = -ENOMEM;
4703 		goto failed_mount;
4704 	}
4705 
4706 	bgl_lock_init(sbi->s_blockgroup_lock);
4707 
4708 	/* Pre-read the descriptors into the buffer cache */
4709 	for (i = 0; i < db_count; i++) {
4710 		block = descriptor_loc(sb, logical_sb_block, i);
4711 		ext4_sb_breadahead_unmovable(sb, block);
4712 	}
4713 
4714 	for (i = 0; i < db_count; i++) {
4715 		struct buffer_head *bh;
4716 
4717 		block = descriptor_loc(sb, logical_sb_block, i);
4718 		bh = ext4_sb_bread_unmovable(sb, block);
4719 		if (IS_ERR(bh)) {
4720 			ext4_msg(sb, KERN_ERR,
4721 			       "can't read group descriptor %d", i);
4722 			db_count = i;
4723 			ret = PTR_ERR(bh);
4724 			bh = NULL;
4725 			goto failed_mount2;
4726 		}
4727 		rcu_read_lock();
4728 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4729 		rcu_read_unlock();
4730 	}
4731 	sbi->s_gdb_count = db_count;
4732 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4733 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4734 		ret = -EFSCORRUPTED;
4735 		goto failed_mount2;
4736 	}
4737 
4738 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4739 
4740 	/* Register extent status tree shrinker */
4741 	if (ext4_es_register_shrinker(sbi))
4742 		goto failed_mount3;
4743 
4744 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4745 	sbi->s_extent_max_zeroout_kb = 32;
4746 
4747 	/*
4748 	 * set up enough so that it can read an inode
4749 	 */
4750 	sb->s_op = &ext4_sops;
4751 	sb->s_export_op = &ext4_export_ops;
4752 	sb->s_xattr = ext4_xattr_handlers;
4753 #ifdef CONFIG_FS_ENCRYPTION
4754 	sb->s_cop = &ext4_cryptops;
4755 #endif
4756 #ifdef CONFIG_FS_VERITY
4757 	sb->s_vop = &ext4_verityops;
4758 #endif
4759 #ifdef CONFIG_QUOTA
4760 	sb->dq_op = &ext4_quota_operations;
4761 	if (ext4_has_feature_quota(sb))
4762 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4763 	else
4764 		sb->s_qcop = &ext4_qctl_operations;
4765 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4766 #endif
4767 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4768 
4769 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4770 	mutex_init(&sbi->s_orphan_lock);
4771 
4772 	/* Initialize fast commit stuff */
4773 	atomic_set(&sbi->s_fc_subtid, 0);
4774 	atomic_set(&sbi->s_fc_ineligible_updates, 0);
4775 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4776 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4777 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4778 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4779 	sbi->s_fc_bytes = 0;
4780 	sbi->s_mount_state &= ~EXT4_FC_INELIGIBLE;
4781 	sbi->s_mount_state &= ~EXT4_FC_COMMITTING;
4782 	spin_lock_init(&sbi->s_fc_lock);
4783 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4784 	sbi->s_fc_replay_state.fc_regions = NULL;
4785 	sbi->s_fc_replay_state.fc_regions_size = 0;
4786 	sbi->s_fc_replay_state.fc_regions_used = 0;
4787 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4788 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4789 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4790 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4791 
4792 	sb->s_root = NULL;
4793 
4794 	needs_recovery = (es->s_last_orphan != 0 ||
4795 			  ext4_has_feature_journal_needs_recovery(sb));
4796 
4797 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4798 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4799 			goto failed_mount3a;
4800 
4801 	/*
4802 	 * The first inode we look at is the journal inode.  Don't try
4803 	 * root first: it may be modified in the journal!
4804 	 */
4805 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4806 		err = ext4_load_journal(sb, es, journal_devnum);
4807 		if (err)
4808 			goto failed_mount3a;
4809 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4810 		   ext4_has_feature_journal_needs_recovery(sb)) {
4811 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4812 		       "suppressed and not mounted read-only");
4813 		goto failed_mount_wq;
4814 	} else {
4815 		/* Nojournal mode, all journal mount options are illegal */
4816 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4817 			ext4_msg(sb, KERN_ERR, "can't mount with "
4818 				 "journal_checksum, fs mounted w/o journal");
4819 			goto failed_mount_wq;
4820 		}
4821 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4822 			ext4_msg(sb, KERN_ERR, "can't mount with "
4823 				 "journal_async_commit, fs mounted w/o journal");
4824 			goto failed_mount_wq;
4825 		}
4826 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4827 			ext4_msg(sb, KERN_ERR, "can't mount with "
4828 				 "commit=%lu, fs mounted w/o journal",
4829 				 sbi->s_commit_interval / HZ);
4830 			goto failed_mount_wq;
4831 		}
4832 		if (EXT4_MOUNT_DATA_FLAGS &
4833 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4834 			ext4_msg(sb, KERN_ERR, "can't mount with "
4835 				 "data=, fs mounted w/o journal");
4836 			goto failed_mount_wq;
4837 		}
4838 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4839 		clear_opt(sb, JOURNAL_CHECKSUM);
4840 		clear_opt(sb, DATA_FLAGS);
4841 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4842 		sbi->s_journal = NULL;
4843 		needs_recovery = 0;
4844 		goto no_journal;
4845 	}
4846 
4847 	if (ext4_has_feature_64bit(sb) &&
4848 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4849 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4850 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4851 		goto failed_mount_wq;
4852 	}
4853 
4854 	if (!set_journal_csum_feature_set(sb)) {
4855 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4856 			 "feature set");
4857 		goto failed_mount_wq;
4858 	}
4859 
4860 	/* We have now updated the journal if required, so we can
4861 	 * validate the data journaling mode. */
4862 	switch (test_opt(sb, DATA_FLAGS)) {
4863 	case 0:
4864 		/* No mode set, assume a default based on the journal
4865 		 * capabilities: ORDERED_DATA if the journal can
4866 		 * cope, else JOURNAL_DATA
4867 		 */
4868 		if (jbd2_journal_check_available_features
4869 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4870 			set_opt(sb, ORDERED_DATA);
4871 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4872 		} else {
4873 			set_opt(sb, JOURNAL_DATA);
4874 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4875 		}
4876 		break;
4877 
4878 	case EXT4_MOUNT_ORDERED_DATA:
4879 	case EXT4_MOUNT_WRITEBACK_DATA:
4880 		if (!jbd2_journal_check_available_features
4881 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4882 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4883 			       "requested data journaling mode");
4884 			goto failed_mount_wq;
4885 		}
4886 	default:
4887 		break;
4888 	}
4889 
4890 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4891 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4892 		ext4_msg(sb, KERN_ERR, "can't mount with "
4893 			"journal_async_commit in data=ordered mode");
4894 		goto failed_mount_wq;
4895 	}
4896 
4897 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4898 
4899 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4900 	sbi->s_journal->j_submit_inode_data_buffers =
4901 		ext4_journal_submit_inode_data_buffers;
4902 	sbi->s_journal->j_finish_inode_data_buffers =
4903 		ext4_journal_finish_inode_data_buffers;
4904 
4905 no_journal:
4906 	if (!test_opt(sb, NO_MBCACHE)) {
4907 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4908 		if (!sbi->s_ea_block_cache) {
4909 			ext4_msg(sb, KERN_ERR,
4910 				 "Failed to create ea_block_cache");
4911 			goto failed_mount_wq;
4912 		}
4913 
4914 		if (ext4_has_feature_ea_inode(sb)) {
4915 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4916 			if (!sbi->s_ea_inode_cache) {
4917 				ext4_msg(sb, KERN_ERR,
4918 					 "Failed to create ea_inode_cache");
4919 				goto failed_mount_wq;
4920 			}
4921 		}
4922 	}
4923 
4924 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4925 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4926 		goto failed_mount_wq;
4927 	}
4928 
4929 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4930 	    !ext4_has_feature_encrypt(sb)) {
4931 		ext4_set_feature_encrypt(sb);
4932 		ext4_commit_super(sb, 1);
4933 	}
4934 
4935 	/*
4936 	 * Get the # of file system overhead blocks from the
4937 	 * superblock if present.
4938 	 */
4939 	if (es->s_overhead_clusters)
4940 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4941 	else {
4942 		err = ext4_calculate_overhead(sb);
4943 		if (err)
4944 			goto failed_mount_wq;
4945 	}
4946 
4947 	/*
4948 	 * The maximum number of concurrent works can be high and
4949 	 * concurrency isn't really necessary.  Limit it to 1.
4950 	 */
4951 	EXT4_SB(sb)->rsv_conversion_wq =
4952 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4953 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4954 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4955 		ret = -ENOMEM;
4956 		goto failed_mount4;
4957 	}
4958 
4959 	/*
4960 	 * The jbd2_journal_load will have done any necessary log recovery,
4961 	 * so we can safely mount the rest of the filesystem now.
4962 	 */
4963 
4964 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4965 	if (IS_ERR(root)) {
4966 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4967 		ret = PTR_ERR(root);
4968 		root = NULL;
4969 		goto failed_mount4;
4970 	}
4971 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4972 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4973 		iput(root);
4974 		goto failed_mount4;
4975 	}
4976 
4977 #ifdef CONFIG_UNICODE
4978 	if (sbi->s_encoding)
4979 		sb->s_d_op = &ext4_dentry_ops;
4980 #endif
4981 
4982 	sb->s_root = d_make_root(root);
4983 	if (!sb->s_root) {
4984 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4985 		ret = -ENOMEM;
4986 		goto failed_mount4;
4987 	}
4988 
4989 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4990 	if (ret == -EROFS) {
4991 		sb->s_flags |= SB_RDONLY;
4992 		ret = 0;
4993 	} else if (ret)
4994 		goto failed_mount4a;
4995 
4996 	ext4_set_resv_clusters(sb);
4997 
4998 	if (test_opt(sb, BLOCK_VALIDITY)) {
4999 		err = ext4_setup_system_zone(sb);
5000 		if (err) {
5001 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
5002 				 "zone (%d)", err);
5003 			goto failed_mount4a;
5004 		}
5005 	}
5006 	ext4_fc_replay_cleanup(sb);
5007 
5008 	ext4_ext_init(sb);
5009 	err = ext4_mb_init(sb);
5010 	if (err) {
5011 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5012 			 err);
5013 		goto failed_mount5;
5014 	}
5015 
5016 	block = ext4_count_free_clusters(sb);
5017 	ext4_free_blocks_count_set(sbi->s_es,
5018 				   EXT4_C2B(sbi, block));
5019 	ext4_superblock_csum_set(sb);
5020 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5021 				  GFP_KERNEL);
5022 	if (!err) {
5023 		unsigned long freei = ext4_count_free_inodes(sb);
5024 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5025 		ext4_superblock_csum_set(sb);
5026 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5027 					  GFP_KERNEL);
5028 	}
5029 	if (!err)
5030 		err = percpu_counter_init(&sbi->s_dirs_counter,
5031 					  ext4_count_dirs(sb), GFP_KERNEL);
5032 	if (!err)
5033 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5034 					  GFP_KERNEL);
5035 	if (!err)
5036 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5037 
5038 	if (err) {
5039 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5040 		goto failed_mount6;
5041 	}
5042 
5043 	if (ext4_has_feature_flex_bg(sb))
5044 		if (!ext4_fill_flex_info(sb)) {
5045 			ext4_msg(sb, KERN_ERR,
5046 			       "unable to initialize "
5047 			       "flex_bg meta info!");
5048 			goto failed_mount6;
5049 		}
5050 
5051 	err = ext4_register_li_request(sb, first_not_zeroed);
5052 	if (err)
5053 		goto failed_mount6;
5054 
5055 	err = ext4_register_sysfs(sb);
5056 	if (err)
5057 		goto failed_mount7;
5058 
5059 #ifdef CONFIG_QUOTA
5060 	/* Enable quota usage during mount. */
5061 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5062 		err = ext4_enable_quotas(sb);
5063 		if (err)
5064 			goto failed_mount8;
5065 	}
5066 #endif  /* CONFIG_QUOTA */
5067 
5068 	/*
5069 	 * Save the original bdev mapping's wb_err value which could be
5070 	 * used to detect the metadata async write error.
5071 	 */
5072 	spin_lock_init(&sbi->s_bdev_wb_lock);
5073 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5074 				 &sbi->s_bdev_wb_err);
5075 	sb->s_bdev->bd_super = sb;
5076 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5077 	ext4_orphan_cleanup(sb, es);
5078 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5079 	if (needs_recovery) {
5080 		ext4_msg(sb, KERN_INFO, "recovery complete");
5081 		err = ext4_mark_recovery_complete(sb, es);
5082 		if (err)
5083 			goto failed_mount8;
5084 	}
5085 	if (EXT4_SB(sb)->s_journal) {
5086 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5087 			descr = " journalled data mode";
5088 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5089 			descr = " ordered data mode";
5090 		else
5091 			descr = " writeback data mode";
5092 	} else
5093 		descr = "out journal";
5094 
5095 	if (test_opt(sb, DISCARD)) {
5096 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5097 		if (!blk_queue_discard(q))
5098 			ext4_msg(sb, KERN_WARNING,
5099 				 "mounting with \"discard\" option, but "
5100 				 "the device does not support discard");
5101 	}
5102 
5103 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5104 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5105 			 "Opts: %.*s%s%s", descr,
5106 			 (int) sizeof(sbi->s_es->s_mount_opts),
5107 			 sbi->s_es->s_mount_opts,
5108 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
5109 
5110 	if (es->s_error_count)
5111 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5112 
5113 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5114 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5115 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5116 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5117 	atomic_set(&sbi->s_warning_count, 0);
5118 	atomic_set(&sbi->s_msg_count, 0);
5119 
5120 	kfree(orig_data);
5121 	return 0;
5122 
5123 cantfind_ext4:
5124 	if (!silent)
5125 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5126 	goto failed_mount;
5127 
5128 failed_mount8:
5129 	ext4_unregister_sysfs(sb);
5130 	kobject_put(&sbi->s_kobj);
5131 failed_mount7:
5132 	ext4_unregister_li_request(sb);
5133 failed_mount6:
5134 	ext4_mb_release(sb);
5135 	rcu_read_lock();
5136 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5137 	if (flex_groups) {
5138 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5139 			kvfree(flex_groups[i]);
5140 		kvfree(flex_groups);
5141 	}
5142 	rcu_read_unlock();
5143 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5144 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5145 	percpu_counter_destroy(&sbi->s_dirs_counter);
5146 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5147 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5148 failed_mount5:
5149 	ext4_ext_release(sb);
5150 	ext4_release_system_zone(sb);
5151 failed_mount4a:
5152 	dput(sb->s_root);
5153 	sb->s_root = NULL;
5154 failed_mount4:
5155 	ext4_msg(sb, KERN_ERR, "mount failed");
5156 	if (EXT4_SB(sb)->rsv_conversion_wq)
5157 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5158 failed_mount_wq:
5159 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5160 	sbi->s_ea_inode_cache = NULL;
5161 
5162 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5163 	sbi->s_ea_block_cache = NULL;
5164 
5165 	if (sbi->s_journal) {
5166 		jbd2_journal_destroy(sbi->s_journal);
5167 		sbi->s_journal = NULL;
5168 	}
5169 failed_mount3a:
5170 	ext4_es_unregister_shrinker(sbi);
5171 failed_mount3:
5172 	del_timer_sync(&sbi->s_err_report);
5173 	if (sbi->s_mmp_tsk)
5174 		kthread_stop(sbi->s_mmp_tsk);
5175 failed_mount2:
5176 	rcu_read_lock();
5177 	group_desc = rcu_dereference(sbi->s_group_desc);
5178 	for (i = 0; i < db_count; i++)
5179 		brelse(group_desc[i]);
5180 	kvfree(group_desc);
5181 	rcu_read_unlock();
5182 failed_mount:
5183 	if (sbi->s_chksum_driver)
5184 		crypto_free_shash(sbi->s_chksum_driver);
5185 
5186 #ifdef CONFIG_UNICODE
5187 	utf8_unload(sbi->s_encoding);
5188 #endif
5189 
5190 #ifdef CONFIG_QUOTA
5191 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5192 		kfree(get_qf_name(sb, sbi, i));
5193 #endif
5194 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5195 	ext4_blkdev_remove(sbi);
5196 	brelse(bh);
5197 out_fail:
5198 	sb->s_fs_info = NULL;
5199 	kfree(sbi->s_blockgroup_lock);
5200 out_free_base:
5201 	kfree(sbi);
5202 	kfree(orig_data);
5203 	fs_put_dax(dax_dev);
5204 	return err ? err : ret;
5205 }
5206 
5207 /*
5208  * Setup any per-fs journal parameters now.  We'll do this both on
5209  * initial mount, once the journal has been initialised but before we've
5210  * done any recovery; and again on any subsequent remount.
5211  */
5212 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5213 {
5214 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5215 
5216 	journal->j_commit_interval = sbi->s_commit_interval;
5217 	journal->j_min_batch_time = sbi->s_min_batch_time;
5218 	journal->j_max_batch_time = sbi->s_max_batch_time;
5219 	ext4_fc_init(sb, journal);
5220 
5221 	write_lock(&journal->j_state_lock);
5222 	if (test_opt(sb, BARRIER))
5223 		journal->j_flags |= JBD2_BARRIER;
5224 	else
5225 		journal->j_flags &= ~JBD2_BARRIER;
5226 	if (test_opt(sb, DATA_ERR_ABORT))
5227 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5228 	else
5229 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5230 	write_unlock(&journal->j_state_lock);
5231 }
5232 
5233 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5234 					     unsigned int journal_inum)
5235 {
5236 	struct inode *journal_inode;
5237 
5238 	/*
5239 	 * Test for the existence of a valid inode on disk.  Bad things
5240 	 * happen if we iget() an unused inode, as the subsequent iput()
5241 	 * will try to delete it.
5242 	 */
5243 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5244 	if (IS_ERR(journal_inode)) {
5245 		ext4_msg(sb, KERN_ERR, "no journal found");
5246 		return NULL;
5247 	}
5248 	if (!journal_inode->i_nlink) {
5249 		make_bad_inode(journal_inode);
5250 		iput(journal_inode);
5251 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5252 		return NULL;
5253 	}
5254 
5255 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5256 		  journal_inode, journal_inode->i_size);
5257 	if (!S_ISREG(journal_inode->i_mode)) {
5258 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5259 		iput(journal_inode);
5260 		return NULL;
5261 	}
5262 	return journal_inode;
5263 }
5264 
5265 static journal_t *ext4_get_journal(struct super_block *sb,
5266 				   unsigned int journal_inum)
5267 {
5268 	struct inode *journal_inode;
5269 	journal_t *journal;
5270 
5271 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5272 		return NULL;
5273 
5274 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5275 	if (!journal_inode)
5276 		return NULL;
5277 
5278 	journal = jbd2_journal_init_inode(journal_inode);
5279 	if (!journal) {
5280 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5281 		iput(journal_inode);
5282 		return NULL;
5283 	}
5284 	journal->j_private = sb;
5285 	ext4_init_journal_params(sb, journal);
5286 	return journal;
5287 }
5288 
5289 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5290 				       dev_t j_dev)
5291 {
5292 	struct buffer_head *bh;
5293 	journal_t *journal;
5294 	ext4_fsblk_t start;
5295 	ext4_fsblk_t len;
5296 	int hblock, blocksize;
5297 	ext4_fsblk_t sb_block;
5298 	unsigned long offset;
5299 	struct ext4_super_block *es;
5300 	struct block_device *bdev;
5301 
5302 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5303 		return NULL;
5304 
5305 	bdev = ext4_blkdev_get(j_dev, sb);
5306 	if (bdev == NULL)
5307 		return NULL;
5308 
5309 	blocksize = sb->s_blocksize;
5310 	hblock = bdev_logical_block_size(bdev);
5311 	if (blocksize < hblock) {
5312 		ext4_msg(sb, KERN_ERR,
5313 			"blocksize too small for journal device");
5314 		goto out_bdev;
5315 	}
5316 
5317 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5318 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5319 	set_blocksize(bdev, blocksize);
5320 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5321 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5322 		       "external journal");
5323 		goto out_bdev;
5324 	}
5325 
5326 	es = (struct ext4_super_block *) (bh->b_data + offset);
5327 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5328 	    !(le32_to_cpu(es->s_feature_incompat) &
5329 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5330 		ext4_msg(sb, KERN_ERR, "external journal has "
5331 					"bad superblock");
5332 		brelse(bh);
5333 		goto out_bdev;
5334 	}
5335 
5336 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5337 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5338 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5339 		ext4_msg(sb, KERN_ERR, "external journal has "
5340 				       "corrupt superblock");
5341 		brelse(bh);
5342 		goto out_bdev;
5343 	}
5344 
5345 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5346 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5347 		brelse(bh);
5348 		goto out_bdev;
5349 	}
5350 
5351 	len = ext4_blocks_count(es);
5352 	start = sb_block + 1;
5353 	brelse(bh);	/* we're done with the superblock */
5354 
5355 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5356 					start, len, blocksize);
5357 	if (!journal) {
5358 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5359 		goto out_bdev;
5360 	}
5361 	journal->j_private = sb;
5362 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5363 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5364 		goto out_journal;
5365 	}
5366 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5367 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5368 					"user (unsupported) - %d",
5369 			be32_to_cpu(journal->j_superblock->s_nr_users));
5370 		goto out_journal;
5371 	}
5372 	EXT4_SB(sb)->s_journal_bdev = bdev;
5373 	ext4_init_journal_params(sb, journal);
5374 	return journal;
5375 
5376 out_journal:
5377 	jbd2_journal_destroy(journal);
5378 out_bdev:
5379 	ext4_blkdev_put(bdev);
5380 	return NULL;
5381 }
5382 
5383 static int ext4_load_journal(struct super_block *sb,
5384 			     struct ext4_super_block *es,
5385 			     unsigned long journal_devnum)
5386 {
5387 	journal_t *journal;
5388 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5389 	dev_t journal_dev;
5390 	int err = 0;
5391 	int really_read_only;
5392 	int journal_dev_ro;
5393 
5394 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5395 		return -EFSCORRUPTED;
5396 
5397 	if (journal_devnum &&
5398 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5399 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5400 			"numbers have changed");
5401 		journal_dev = new_decode_dev(journal_devnum);
5402 	} else
5403 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5404 
5405 	if (journal_inum && journal_dev) {
5406 		ext4_msg(sb, KERN_ERR,
5407 			 "filesystem has both journal inode and journal device!");
5408 		return -EINVAL;
5409 	}
5410 
5411 	if (journal_inum) {
5412 		journal = ext4_get_journal(sb, journal_inum);
5413 		if (!journal)
5414 			return -EINVAL;
5415 	} else {
5416 		journal = ext4_get_dev_journal(sb, journal_dev);
5417 		if (!journal)
5418 			return -EINVAL;
5419 	}
5420 
5421 	journal_dev_ro = bdev_read_only(journal->j_dev);
5422 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5423 
5424 	if (journal_dev_ro && !sb_rdonly(sb)) {
5425 		ext4_msg(sb, KERN_ERR,
5426 			 "journal device read-only, try mounting with '-o ro'");
5427 		err = -EROFS;
5428 		goto err_out;
5429 	}
5430 
5431 	/*
5432 	 * Are we loading a blank journal or performing recovery after a
5433 	 * crash?  For recovery, we need to check in advance whether we
5434 	 * can get read-write access to the device.
5435 	 */
5436 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5437 		if (sb_rdonly(sb)) {
5438 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5439 					"required on readonly filesystem");
5440 			if (really_read_only) {
5441 				ext4_msg(sb, KERN_ERR, "write access "
5442 					"unavailable, cannot proceed "
5443 					"(try mounting with noload)");
5444 				err = -EROFS;
5445 				goto err_out;
5446 			}
5447 			ext4_msg(sb, KERN_INFO, "write access will "
5448 			       "be enabled during recovery");
5449 		}
5450 	}
5451 
5452 	if (!(journal->j_flags & JBD2_BARRIER))
5453 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5454 
5455 	if (!ext4_has_feature_journal_needs_recovery(sb))
5456 		err = jbd2_journal_wipe(journal, !really_read_only);
5457 	if (!err) {
5458 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5459 		if (save)
5460 			memcpy(save, ((char *) es) +
5461 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5462 		err = jbd2_journal_load(journal);
5463 		if (save)
5464 			memcpy(((char *) es) + EXT4_S_ERR_START,
5465 			       save, EXT4_S_ERR_LEN);
5466 		kfree(save);
5467 	}
5468 
5469 	if (err) {
5470 		ext4_msg(sb, KERN_ERR, "error loading journal");
5471 		goto err_out;
5472 	}
5473 
5474 	EXT4_SB(sb)->s_journal = journal;
5475 	err = ext4_clear_journal_err(sb, es);
5476 	if (err) {
5477 		EXT4_SB(sb)->s_journal = NULL;
5478 		jbd2_journal_destroy(journal);
5479 		return err;
5480 	}
5481 
5482 	if (!really_read_only && journal_devnum &&
5483 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5484 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5485 
5486 		/* Make sure we flush the recovery flag to disk. */
5487 		ext4_commit_super(sb, 1);
5488 	}
5489 
5490 	return 0;
5491 
5492 err_out:
5493 	jbd2_journal_destroy(journal);
5494 	return err;
5495 }
5496 
5497 static int ext4_commit_super(struct super_block *sb, int sync)
5498 {
5499 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5500 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5501 	int error = 0;
5502 
5503 	if (!sbh || block_device_ejected(sb))
5504 		return error;
5505 
5506 	/*
5507 	 * If the file system is mounted read-only, don't update the
5508 	 * superblock write time.  This avoids updating the superblock
5509 	 * write time when we are mounting the root file system
5510 	 * read/only but we need to replay the journal; at that point,
5511 	 * for people who are east of GMT and who make their clock
5512 	 * tick in localtime for Windows bug-for-bug compatibility,
5513 	 * the clock is set in the future, and this will cause e2fsck
5514 	 * to complain and force a full file system check.
5515 	 */
5516 	if (!(sb->s_flags & SB_RDONLY))
5517 		ext4_update_tstamp(es, s_wtime);
5518 	if (sb->s_bdev->bd_part)
5519 		es->s_kbytes_written =
5520 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5521 			    ((part_stat_read(sb->s_bdev->bd_part,
5522 					     sectors[STAT_WRITE]) -
5523 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5524 	else
5525 		es->s_kbytes_written =
5526 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5527 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5528 		ext4_free_blocks_count_set(es,
5529 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5530 				&EXT4_SB(sb)->s_freeclusters_counter)));
5531 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5532 		es->s_free_inodes_count =
5533 			cpu_to_le32(percpu_counter_sum_positive(
5534 				&EXT4_SB(sb)->s_freeinodes_counter));
5535 	BUFFER_TRACE(sbh, "marking dirty");
5536 	ext4_superblock_csum_set(sb);
5537 	if (sync)
5538 		lock_buffer(sbh);
5539 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5540 		/*
5541 		 * Oh, dear.  A previous attempt to write the
5542 		 * superblock failed.  This could happen because the
5543 		 * USB device was yanked out.  Or it could happen to
5544 		 * be a transient write error and maybe the block will
5545 		 * be remapped.  Nothing we can do but to retry the
5546 		 * write and hope for the best.
5547 		 */
5548 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5549 		       "superblock detected");
5550 		clear_buffer_write_io_error(sbh);
5551 		set_buffer_uptodate(sbh);
5552 	}
5553 	mark_buffer_dirty(sbh);
5554 	if (sync) {
5555 		unlock_buffer(sbh);
5556 		error = __sync_dirty_buffer(sbh,
5557 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5558 		if (buffer_write_io_error(sbh)) {
5559 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5560 			       "superblock");
5561 			clear_buffer_write_io_error(sbh);
5562 			set_buffer_uptodate(sbh);
5563 		}
5564 	}
5565 	return error;
5566 }
5567 
5568 /*
5569  * Have we just finished recovery?  If so, and if we are mounting (or
5570  * remounting) the filesystem readonly, then we will end up with a
5571  * consistent fs on disk.  Record that fact.
5572  */
5573 static int ext4_mark_recovery_complete(struct super_block *sb,
5574 				       struct ext4_super_block *es)
5575 {
5576 	int err;
5577 	journal_t *journal = EXT4_SB(sb)->s_journal;
5578 
5579 	if (!ext4_has_feature_journal(sb)) {
5580 		if (journal != NULL) {
5581 			ext4_error(sb, "Journal got removed while the fs was "
5582 				   "mounted!");
5583 			return -EFSCORRUPTED;
5584 		}
5585 		return 0;
5586 	}
5587 	jbd2_journal_lock_updates(journal);
5588 	err = jbd2_journal_flush(journal);
5589 	if (err < 0)
5590 		goto out;
5591 
5592 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5593 		ext4_clear_feature_journal_needs_recovery(sb);
5594 		ext4_commit_super(sb, 1);
5595 	}
5596 out:
5597 	jbd2_journal_unlock_updates(journal);
5598 	return err;
5599 }
5600 
5601 /*
5602  * If we are mounting (or read-write remounting) a filesystem whose journal
5603  * has recorded an error from a previous lifetime, move that error to the
5604  * main filesystem now.
5605  */
5606 static int ext4_clear_journal_err(struct super_block *sb,
5607 				   struct ext4_super_block *es)
5608 {
5609 	journal_t *journal;
5610 	int j_errno;
5611 	const char *errstr;
5612 
5613 	if (!ext4_has_feature_journal(sb)) {
5614 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5615 		return -EFSCORRUPTED;
5616 	}
5617 
5618 	journal = EXT4_SB(sb)->s_journal;
5619 
5620 	/*
5621 	 * Now check for any error status which may have been recorded in the
5622 	 * journal by a prior ext4_error() or ext4_abort()
5623 	 */
5624 
5625 	j_errno = jbd2_journal_errno(journal);
5626 	if (j_errno) {
5627 		char nbuf[16];
5628 
5629 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5630 		ext4_warning(sb, "Filesystem error recorded "
5631 			     "from previous mount: %s", errstr);
5632 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5633 
5634 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5635 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5636 		ext4_commit_super(sb, 1);
5637 
5638 		jbd2_journal_clear_err(journal);
5639 		jbd2_journal_update_sb_errno(journal);
5640 	}
5641 	return 0;
5642 }
5643 
5644 /*
5645  * Force the running and committing transactions to commit,
5646  * and wait on the commit.
5647  */
5648 int ext4_force_commit(struct super_block *sb)
5649 {
5650 	journal_t *journal;
5651 
5652 	if (sb_rdonly(sb))
5653 		return 0;
5654 
5655 	journal = EXT4_SB(sb)->s_journal;
5656 	return ext4_journal_force_commit(journal);
5657 }
5658 
5659 static int ext4_sync_fs(struct super_block *sb, int wait)
5660 {
5661 	int ret = 0;
5662 	tid_t target;
5663 	bool needs_barrier = false;
5664 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5665 
5666 	if (unlikely(ext4_forced_shutdown(sbi)))
5667 		return 0;
5668 
5669 	trace_ext4_sync_fs(sb, wait);
5670 	flush_workqueue(sbi->rsv_conversion_wq);
5671 	/*
5672 	 * Writeback quota in non-journalled quota case - journalled quota has
5673 	 * no dirty dquots
5674 	 */
5675 	dquot_writeback_dquots(sb, -1);
5676 	/*
5677 	 * Data writeback is possible w/o journal transaction, so barrier must
5678 	 * being sent at the end of the function. But we can skip it if
5679 	 * transaction_commit will do it for us.
5680 	 */
5681 	if (sbi->s_journal) {
5682 		target = jbd2_get_latest_transaction(sbi->s_journal);
5683 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5684 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5685 			needs_barrier = true;
5686 
5687 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5688 			if (wait)
5689 				ret = jbd2_log_wait_commit(sbi->s_journal,
5690 							   target);
5691 		}
5692 	} else if (wait && test_opt(sb, BARRIER))
5693 		needs_barrier = true;
5694 	if (needs_barrier) {
5695 		int err;
5696 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL);
5697 		if (!ret)
5698 			ret = err;
5699 	}
5700 
5701 	return ret;
5702 }
5703 
5704 /*
5705  * LVM calls this function before a (read-only) snapshot is created.  This
5706  * gives us a chance to flush the journal completely and mark the fs clean.
5707  *
5708  * Note that only this function cannot bring a filesystem to be in a clean
5709  * state independently. It relies on upper layer to stop all data & metadata
5710  * modifications.
5711  */
5712 static int ext4_freeze(struct super_block *sb)
5713 {
5714 	int error = 0;
5715 	journal_t *journal;
5716 
5717 	if (sb_rdonly(sb))
5718 		return 0;
5719 
5720 	journal = EXT4_SB(sb)->s_journal;
5721 
5722 	if (journal) {
5723 		/* Now we set up the journal barrier. */
5724 		jbd2_journal_lock_updates(journal);
5725 
5726 		/*
5727 		 * Don't clear the needs_recovery flag if we failed to
5728 		 * flush the journal.
5729 		 */
5730 		error = jbd2_journal_flush(journal);
5731 		if (error < 0)
5732 			goto out;
5733 
5734 		/* Journal blocked and flushed, clear needs_recovery flag. */
5735 		ext4_clear_feature_journal_needs_recovery(sb);
5736 	}
5737 
5738 	error = ext4_commit_super(sb, 1);
5739 out:
5740 	if (journal)
5741 		/* we rely on upper layer to stop further updates */
5742 		jbd2_journal_unlock_updates(journal);
5743 	return error;
5744 }
5745 
5746 /*
5747  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5748  * flag here, even though the filesystem is not technically dirty yet.
5749  */
5750 static int ext4_unfreeze(struct super_block *sb)
5751 {
5752 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5753 		return 0;
5754 
5755 	if (EXT4_SB(sb)->s_journal) {
5756 		/* Reset the needs_recovery flag before the fs is unlocked. */
5757 		ext4_set_feature_journal_needs_recovery(sb);
5758 	}
5759 
5760 	ext4_commit_super(sb, 1);
5761 	return 0;
5762 }
5763 
5764 /*
5765  * Structure to save mount options for ext4_remount's benefit
5766  */
5767 struct ext4_mount_options {
5768 	unsigned long s_mount_opt;
5769 	unsigned long s_mount_opt2;
5770 	kuid_t s_resuid;
5771 	kgid_t s_resgid;
5772 	unsigned long s_commit_interval;
5773 	u32 s_min_batch_time, s_max_batch_time;
5774 #ifdef CONFIG_QUOTA
5775 	int s_jquota_fmt;
5776 	char *s_qf_names[EXT4_MAXQUOTAS];
5777 #endif
5778 };
5779 
5780 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5781 {
5782 	struct ext4_super_block *es;
5783 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5784 	unsigned long old_sb_flags, vfs_flags;
5785 	struct ext4_mount_options old_opts;
5786 	int enable_quota = 0;
5787 	ext4_group_t g;
5788 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5789 	int err = 0;
5790 #ifdef CONFIG_QUOTA
5791 	int i, j;
5792 	char *to_free[EXT4_MAXQUOTAS];
5793 #endif
5794 	char *orig_data = kstrdup(data, GFP_KERNEL);
5795 
5796 	if (data && !orig_data)
5797 		return -ENOMEM;
5798 
5799 	/* Store the original options */
5800 	old_sb_flags = sb->s_flags;
5801 	old_opts.s_mount_opt = sbi->s_mount_opt;
5802 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5803 	old_opts.s_resuid = sbi->s_resuid;
5804 	old_opts.s_resgid = sbi->s_resgid;
5805 	old_opts.s_commit_interval = sbi->s_commit_interval;
5806 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5807 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5808 #ifdef CONFIG_QUOTA
5809 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5810 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5811 		if (sbi->s_qf_names[i]) {
5812 			char *qf_name = get_qf_name(sb, sbi, i);
5813 
5814 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5815 			if (!old_opts.s_qf_names[i]) {
5816 				for (j = 0; j < i; j++)
5817 					kfree(old_opts.s_qf_names[j]);
5818 				kfree(orig_data);
5819 				return -ENOMEM;
5820 			}
5821 		} else
5822 			old_opts.s_qf_names[i] = NULL;
5823 #endif
5824 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5825 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5826 
5827 	/*
5828 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5829 	 * either way we need to make sure it matches in both *flags and
5830 	 * s_flags. Copy those selected flags from *flags to s_flags
5831 	 */
5832 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5833 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5834 
5835 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5836 		err = -EINVAL;
5837 		goto restore_opts;
5838 	}
5839 
5840 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5841 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5842 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5843 			 "during remount not supported; ignoring");
5844 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5845 	}
5846 
5847 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5848 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5849 			ext4_msg(sb, KERN_ERR, "can't mount with "
5850 				 "both data=journal and delalloc");
5851 			err = -EINVAL;
5852 			goto restore_opts;
5853 		}
5854 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5855 			ext4_msg(sb, KERN_ERR, "can't mount with "
5856 				 "both data=journal and dioread_nolock");
5857 			err = -EINVAL;
5858 			goto restore_opts;
5859 		}
5860 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5861 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5862 			ext4_msg(sb, KERN_ERR, "can't mount with "
5863 				"journal_async_commit in data=ordered mode");
5864 			err = -EINVAL;
5865 			goto restore_opts;
5866 		}
5867 	}
5868 
5869 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5870 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5871 		err = -EINVAL;
5872 		goto restore_opts;
5873 	}
5874 
5875 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5876 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5877 
5878 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5879 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5880 
5881 	es = sbi->s_es;
5882 
5883 	if (sbi->s_journal) {
5884 		ext4_init_journal_params(sb, sbi->s_journal);
5885 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5886 	}
5887 
5888 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5889 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5890 			err = -EROFS;
5891 			goto restore_opts;
5892 		}
5893 
5894 		if (*flags & SB_RDONLY) {
5895 			err = sync_filesystem(sb);
5896 			if (err < 0)
5897 				goto restore_opts;
5898 			err = dquot_suspend(sb, -1);
5899 			if (err < 0)
5900 				goto restore_opts;
5901 
5902 			/*
5903 			 * First of all, the unconditional stuff we have to do
5904 			 * to disable replay of the journal when we next remount
5905 			 */
5906 			sb->s_flags |= SB_RDONLY;
5907 
5908 			/*
5909 			 * OK, test if we are remounting a valid rw partition
5910 			 * readonly, and if so set the rdonly flag and then
5911 			 * mark the partition as valid again.
5912 			 */
5913 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5914 			    (sbi->s_mount_state & EXT4_VALID_FS))
5915 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5916 
5917 			if (sbi->s_journal) {
5918 				/*
5919 				 * We let remount-ro finish even if marking fs
5920 				 * as clean failed...
5921 				 */
5922 				ext4_mark_recovery_complete(sb, es);
5923 			}
5924 			if (sbi->s_mmp_tsk)
5925 				kthread_stop(sbi->s_mmp_tsk);
5926 		} else {
5927 			/* Make sure we can mount this feature set readwrite */
5928 			if (ext4_has_feature_readonly(sb) ||
5929 			    !ext4_feature_set_ok(sb, 0)) {
5930 				err = -EROFS;
5931 				goto restore_opts;
5932 			}
5933 			/*
5934 			 * Make sure the group descriptor checksums
5935 			 * are sane.  If they aren't, refuse to remount r/w.
5936 			 */
5937 			for (g = 0; g < sbi->s_groups_count; g++) {
5938 				struct ext4_group_desc *gdp =
5939 					ext4_get_group_desc(sb, g, NULL);
5940 
5941 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5942 					ext4_msg(sb, KERN_ERR,
5943 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5944 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5945 					       le16_to_cpu(gdp->bg_checksum));
5946 					err = -EFSBADCRC;
5947 					goto restore_opts;
5948 				}
5949 			}
5950 
5951 			/*
5952 			 * If we have an unprocessed orphan list hanging
5953 			 * around from a previously readonly bdev mount,
5954 			 * require a full umount/remount for now.
5955 			 */
5956 			if (es->s_last_orphan) {
5957 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5958 				       "remount RDWR because of unprocessed "
5959 				       "orphan inode list.  Please "
5960 				       "umount/remount instead");
5961 				err = -EINVAL;
5962 				goto restore_opts;
5963 			}
5964 
5965 			/*
5966 			 * Mounting a RDONLY partition read-write, so reread
5967 			 * and store the current valid flag.  (It may have
5968 			 * been changed by e2fsck since we originally mounted
5969 			 * the partition.)
5970 			 */
5971 			if (sbi->s_journal) {
5972 				err = ext4_clear_journal_err(sb, es);
5973 				if (err)
5974 					goto restore_opts;
5975 			}
5976 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5977 
5978 			err = ext4_setup_super(sb, es, 0);
5979 			if (err)
5980 				goto restore_opts;
5981 
5982 			sb->s_flags &= ~SB_RDONLY;
5983 			if (ext4_has_feature_mmp(sb))
5984 				if (ext4_multi_mount_protect(sb,
5985 						le64_to_cpu(es->s_mmp_block))) {
5986 					err = -EROFS;
5987 					goto restore_opts;
5988 				}
5989 			enable_quota = 1;
5990 		}
5991 	}
5992 
5993 	/*
5994 	 * Reinitialize lazy itable initialization thread based on
5995 	 * current settings
5996 	 */
5997 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5998 		ext4_unregister_li_request(sb);
5999 	else {
6000 		ext4_group_t first_not_zeroed;
6001 		first_not_zeroed = ext4_has_uninit_itable(sb);
6002 		ext4_register_li_request(sb, first_not_zeroed);
6003 	}
6004 
6005 	/*
6006 	 * Handle creation of system zone data early because it can fail.
6007 	 * Releasing of existing data is done when we are sure remount will
6008 	 * succeed.
6009 	 */
6010 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6011 		err = ext4_setup_system_zone(sb);
6012 		if (err)
6013 			goto restore_opts;
6014 	}
6015 
6016 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6017 		err = ext4_commit_super(sb, 1);
6018 		if (err)
6019 			goto restore_opts;
6020 	}
6021 
6022 #ifdef CONFIG_QUOTA
6023 	/* Release old quota file names */
6024 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6025 		kfree(old_opts.s_qf_names[i]);
6026 	if (enable_quota) {
6027 		if (sb_any_quota_suspended(sb))
6028 			dquot_resume(sb, -1);
6029 		else if (ext4_has_feature_quota(sb)) {
6030 			err = ext4_enable_quotas(sb);
6031 			if (err)
6032 				goto restore_opts;
6033 		}
6034 	}
6035 #endif
6036 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6037 		ext4_release_system_zone(sb);
6038 
6039 	/*
6040 	 * Some options can be enabled by ext4 and/or by VFS mount flag
6041 	 * either way we need to make sure it matches in both *flags and
6042 	 * s_flags. Copy those selected flags from s_flags to *flags
6043 	 */
6044 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6045 
6046 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
6047 	kfree(orig_data);
6048 	return 0;
6049 
6050 restore_opts:
6051 	sb->s_flags = old_sb_flags;
6052 	sbi->s_mount_opt = old_opts.s_mount_opt;
6053 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6054 	sbi->s_resuid = old_opts.s_resuid;
6055 	sbi->s_resgid = old_opts.s_resgid;
6056 	sbi->s_commit_interval = old_opts.s_commit_interval;
6057 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6058 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6059 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6060 		ext4_release_system_zone(sb);
6061 #ifdef CONFIG_QUOTA
6062 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6063 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6064 		to_free[i] = get_qf_name(sb, sbi, i);
6065 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6066 	}
6067 	synchronize_rcu();
6068 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6069 		kfree(to_free[i]);
6070 #endif
6071 	kfree(orig_data);
6072 	return err;
6073 }
6074 
6075 #ifdef CONFIG_QUOTA
6076 static int ext4_statfs_project(struct super_block *sb,
6077 			       kprojid_t projid, struct kstatfs *buf)
6078 {
6079 	struct kqid qid;
6080 	struct dquot *dquot;
6081 	u64 limit;
6082 	u64 curblock;
6083 
6084 	qid = make_kqid_projid(projid);
6085 	dquot = dqget(sb, qid);
6086 	if (IS_ERR(dquot))
6087 		return PTR_ERR(dquot);
6088 	spin_lock(&dquot->dq_dqb_lock);
6089 
6090 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6091 			     dquot->dq_dqb.dqb_bhardlimit);
6092 	limit >>= sb->s_blocksize_bits;
6093 
6094 	if (limit && buf->f_blocks > limit) {
6095 		curblock = (dquot->dq_dqb.dqb_curspace +
6096 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6097 		buf->f_blocks = limit;
6098 		buf->f_bfree = buf->f_bavail =
6099 			(buf->f_blocks > curblock) ?
6100 			 (buf->f_blocks - curblock) : 0;
6101 	}
6102 
6103 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6104 			     dquot->dq_dqb.dqb_ihardlimit);
6105 	if (limit && buf->f_files > limit) {
6106 		buf->f_files = limit;
6107 		buf->f_ffree =
6108 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6109 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6110 	}
6111 
6112 	spin_unlock(&dquot->dq_dqb_lock);
6113 	dqput(dquot);
6114 	return 0;
6115 }
6116 #endif
6117 
6118 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6119 {
6120 	struct super_block *sb = dentry->d_sb;
6121 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6122 	struct ext4_super_block *es = sbi->s_es;
6123 	ext4_fsblk_t overhead = 0, resv_blocks;
6124 	u64 fsid;
6125 	s64 bfree;
6126 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6127 
6128 	if (!test_opt(sb, MINIX_DF))
6129 		overhead = sbi->s_overhead;
6130 
6131 	buf->f_type = EXT4_SUPER_MAGIC;
6132 	buf->f_bsize = sb->s_blocksize;
6133 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6134 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6135 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6136 	/* prevent underflow in case that few free space is available */
6137 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6138 	buf->f_bavail = buf->f_bfree -
6139 			(ext4_r_blocks_count(es) + resv_blocks);
6140 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6141 		buf->f_bavail = 0;
6142 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6143 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6144 	buf->f_namelen = EXT4_NAME_LEN;
6145 	fsid = le64_to_cpup((void *)es->s_uuid) ^
6146 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
6147 	buf->f_fsid = u64_to_fsid(fsid);
6148 
6149 #ifdef CONFIG_QUOTA
6150 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6151 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6152 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6153 #endif
6154 	return 0;
6155 }
6156 
6157 
6158 #ifdef CONFIG_QUOTA
6159 
6160 /*
6161  * Helper functions so that transaction is started before we acquire dqio_sem
6162  * to keep correct lock ordering of transaction > dqio_sem
6163  */
6164 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6165 {
6166 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6167 }
6168 
6169 static int ext4_write_dquot(struct dquot *dquot)
6170 {
6171 	int ret, err;
6172 	handle_t *handle;
6173 	struct inode *inode;
6174 
6175 	inode = dquot_to_inode(dquot);
6176 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6177 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6178 	if (IS_ERR(handle))
6179 		return PTR_ERR(handle);
6180 	ret = dquot_commit(dquot);
6181 	err = ext4_journal_stop(handle);
6182 	if (!ret)
6183 		ret = err;
6184 	return ret;
6185 }
6186 
6187 static int ext4_acquire_dquot(struct dquot *dquot)
6188 {
6189 	int ret, err;
6190 	handle_t *handle;
6191 
6192 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6193 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6194 	if (IS_ERR(handle))
6195 		return PTR_ERR(handle);
6196 	ret = dquot_acquire(dquot);
6197 	err = ext4_journal_stop(handle);
6198 	if (!ret)
6199 		ret = err;
6200 	return ret;
6201 }
6202 
6203 static int ext4_release_dquot(struct dquot *dquot)
6204 {
6205 	int ret, err;
6206 	handle_t *handle;
6207 
6208 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6209 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6210 	if (IS_ERR(handle)) {
6211 		/* Release dquot anyway to avoid endless cycle in dqput() */
6212 		dquot_release(dquot);
6213 		return PTR_ERR(handle);
6214 	}
6215 	ret = dquot_release(dquot);
6216 	err = ext4_journal_stop(handle);
6217 	if (!ret)
6218 		ret = err;
6219 	return ret;
6220 }
6221 
6222 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6223 {
6224 	struct super_block *sb = dquot->dq_sb;
6225 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6226 
6227 	/* Are we journaling quotas? */
6228 	if (ext4_has_feature_quota(sb) ||
6229 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
6230 		dquot_mark_dquot_dirty(dquot);
6231 		return ext4_write_dquot(dquot);
6232 	} else {
6233 		return dquot_mark_dquot_dirty(dquot);
6234 	}
6235 }
6236 
6237 static int ext4_write_info(struct super_block *sb, int type)
6238 {
6239 	int ret, err;
6240 	handle_t *handle;
6241 
6242 	/* Data block + inode block */
6243 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6244 	if (IS_ERR(handle))
6245 		return PTR_ERR(handle);
6246 	ret = dquot_commit_info(sb, type);
6247 	err = ext4_journal_stop(handle);
6248 	if (!ret)
6249 		ret = err;
6250 	return ret;
6251 }
6252 
6253 /*
6254  * Turn on quotas during mount time - we need to find
6255  * the quota file and such...
6256  */
6257 static int ext4_quota_on_mount(struct super_block *sb, int type)
6258 {
6259 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6260 					EXT4_SB(sb)->s_jquota_fmt, type);
6261 }
6262 
6263 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6264 {
6265 	struct ext4_inode_info *ei = EXT4_I(inode);
6266 
6267 	/* The first argument of lockdep_set_subclass has to be
6268 	 * *exactly* the same as the argument to init_rwsem() --- in
6269 	 * this case, in init_once() --- or lockdep gets unhappy
6270 	 * because the name of the lock is set using the
6271 	 * stringification of the argument to init_rwsem().
6272 	 */
6273 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6274 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6275 }
6276 
6277 /*
6278  * Standard function to be called on quota_on
6279  */
6280 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6281 			 const struct path *path)
6282 {
6283 	int err;
6284 
6285 	if (!test_opt(sb, QUOTA))
6286 		return -EINVAL;
6287 
6288 	/* Quotafile not on the same filesystem? */
6289 	if (path->dentry->d_sb != sb)
6290 		return -EXDEV;
6291 
6292 	/* Quota already enabled for this file? */
6293 	if (IS_NOQUOTA(d_inode(path->dentry)))
6294 		return -EBUSY;
6295 
6296 	/* Journaling quota? */
6297 	if (EXT4_SB(sb)->s_qf_names[type]) {
6298 		/* Quotafile not in fs root? */
6299 		if (path->dentry->d_parent != sb->s_root)
6300 			ext4_msg(sb, KERN_WARNING,
6301 				"Quota file not on filesystem root. "
6302 				"Journaled quota will not work");
6303 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6304 	} else {
6305 		/*
6306 		 * Clear the flag just in case mount options changed since
6307 		 * last time.
6308 		 */
6309 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6310 	}
6311 
6312 	/*
6313 	 * When we journal data on quota file, we have to flush journal to see
6314 	 * all updates to the file when we bypass pagecache...
6315 	 */
6316 	if (EXT4_SB(sb)->s_journal &&
6317 	    ext4_should_journal_data(d_inode(path->dentry))) {
6318 		/*
6319 		 * We don't need to lock updates but journal_flush() could
6320 		 * otherwise be livelocked...
6321 		 */
6322 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6323 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
6324 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6325 		if (err)
6326 			return err;
6327 	}
6328 
6329 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6330 	err = dquot_quota_on(sb, type, format_id, path);
6331 	if (err) {
6332 		lockdep_set_quota_inode(path->dentry->d_inode,
6333 					     I_DATA_SEM_NORMAL);
6334 	} else {
6335 		struct inode *inode = d_inode(path->dentry);
6336 		handle_t *handle;
6337 
6338 		/*
6339 		 * Set inode flags to prevent userspace from messing with quota
6340 		 * files. If this fails, we return success anyway since quotas
6341 		 * are already enabled and this is not a hard failure.
6342 		 */
6343 		inode_lock(inode);
6344 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6345 		if (IS_ERR(handle))
6346 			goto unlock_inode;
6347 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6348 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6349 				S_NOATIME | S_IMMUTABLE);
6350 		err = ext4_mark_inode_dirty(handle, inode);
6351 		ext4_journal_stop(handle);
6352 	unlock_inode:
6353 		inode_unlock(inode);
6354 	}
6355 	return err;
6356 }
6357 
6358 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6359 			     unsigned int flags)
6360 {
6361 	int err;
6362 	struct inode *qf_inode;
6363 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6364 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6365 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6366 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6367 	};
6368 
6369 	BUG_ON(!ext4_has_feature_quota(sb));
6370 
6371 	if (!qf_inums[type])
6372 		return -EPERM;
6373 
6374 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6375 	if (IS_ERR(qf_inode)) {
6376 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6377 		return PTR_ERR(qf_inode);
6378 	}
6379 
6380 	/* Don't account quota for quota files to avoid recursion */
6381 	qf_inode->i_flags |= S_NOQUOTA;
6382 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6383 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6384 	if (err)
6385 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6386 	iput(qf_inode);
6387 
6388 	return err;
6389 }
6390 
6391 /* Enable usage tracking for all quota types. */
6392 static int ext4_enable_quotas(struct super_block *sb)
6393 {
6394 	int type, err = 0;
6395 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6396 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6397 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6398 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6399 	};
6400 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6401 		test_opt(sb, USRQUOTA),
6402 		test_opt(sb, GRPQUOTA),
6403 		test_opt(sb, PRJQUOTA),
6404 	};
6405 
6406 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6407 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6408 		if (qf_inums[type]) {
6409 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6410 				DQUOT_USAGE_ENABLED |
6411 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6412 			if (err) {
6413 				ext4_warning(sb,
6414 					"Failed to enable quota tracking "
6415 					"(type=%d, err=%d). Please run "
6416 					"e2fsck to fix.", type, err);
6417 				for (type--; type >= 0; type--)
6418 					dquot_quota_off(sb, type);
6419 
6420 				return err;
6421 			}
6422 		}
6423 	}
6424 	return 0;
6425 }
6426 
6427 static int ext4_quota_off(struct super_block *sb, int type)
6428 {
6429 	struct inode *inode = sb_dqopt(sb)->files[type];
6430 	handle_t *handle;
6431 	int err;
6432 
6433 	/* Force all delayed allocation blocks to be allocated.
6434 	 * Caller already holds s_umount sem */
6435 	if (test_opt(sb, DELALLOC))
6436 		sync_filesystem(sb);
6437 
6438 	if (!inode || !igrab(inode))
6439 		goto out;
6440 
6441 	err = dquot_quota_off(sb, type);
6442 	if (err || ext4_has_feature_quota(sb))
6443 		goto out_put;
6444 
6445 	inode_lock(inode);
6446 	/*
6447 	 * Update modification times of quota files when userspace can
6448 	 * start looking at them. If we fail, we return success anyway since
6449 	 * this is not a hard failure and quotas are already disabled.
6450 	 */
6451 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6452 	if (IS_ERR(handle)) {
6453 		err = PTR_ERR(handle);
6454 		goto out_unlock;
6455 	}
6456 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6457 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6458 	inode->i_mtime = inode->i_ctime = current_time(inode);
6459 	err = ext4_mark_inode_dirty(handle, inode);
6460 	ext4_journal_stop(handle);
6461 out_unlock:
6462 	inode_unlock(inode);
6463 out_put:
6464 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6465 	iput(inode);
6466 	return err;
6467 out:
6468 	return dquot_quota_off(sb, type);
6469 }
6470 
6471 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6472  * acquiring the locks... As quota files are never truncated and quota code
6473  * itself serializes the operations (and no one else should touch the files)
6474  * we don't have to be afraid of races */
6475 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6476 			       size_t len, loff_t off)
6477 {
6478 	struct inode *inode = sb_dqopt(sb)->files[type];
6479 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6480 	int offset = off & (sb->s_blocksize - 1);
6481 	int tocopy;
6482 	size_t toread;
6483 	struct buffer_head *bh;
6484 	loff_t i_size = i_size_read(inode);
6485 
6486 	if (off > i_size)
6487 		return 0;
6488 	if (off+len > i_size)
6489 		len = i_size-off;
6490 	toread = len;
6491 	while (toread > 0) {
6492 		tocopy = sb->s_blocksize - offset < toread ?
6493 				sb->s_blocksize - offset : toread;
6494 		bh = ext4_bread(NULL, inode, blk, 0);
6495 		if (IS_ERR(bh))
6496 			return PTR_ERR(bh);
6497 		if (!bh)	/* A hole? */
6498 			memset(data, 0, tocopy);
6499 		else
6500 			memcpy(data, bh->b_data+offset, tocopy);
6501 		brelse(bh);
6502 		offset = 0;
6503 		toread -= tocopy;
6504 		data += tocopy;
6505 		blk++;
6506 	}
6507 	return len;
6508 }
6509 
6510 /* Write to quotafile (we know the transaction is already started and has
6511  * enough credits) */
6512 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6513 				const char *data, size_t len, loff_t off)
6514 {
6515 	struct inode *inode = sb_dqopt(sb)->files[type];
6516 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6517 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6518 	int retries = 0;
6519 	struct buffer_head *bh;
6520 	handle_t *handle = journal_current_handle();
6521 
6522 	if (EXT4_SB(sb)->s_journal && !handle) {
6523 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6524 			" cancelled because transaction is not started",
6525 			(unsigned long long)off, (unsigned long long)len);
6526 		return -EIO;
6527 	}
6528 	/*
6529 	 * Since we account only one data block in transaction credits,
6530 	 * then it is impossible to cross a block boundary.
6531 	 */
6532 	if (sb->s_blocksize - offset < len) {
6533 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6534 			" cancelled because not block aligned",
6535 			(unsigned long long)off, (unsigned long long)len);
6536 		return -EIO;
6537 	}
6538 
6539 	do {
6540 		bh = ext4_bread(handle, inode, blk,
6541 				EXT4_GET_BLOCKS_CREATE |
6542 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6543 	} while (PTR_ERR(bh) == -ENOSPC &&
6544 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6545 	if (IS_ERR(bh))
6546 		return PTR_ERR(bh);
6547 	if (!bh)
6548 		goto out;
6549 	BUFFER_TRACE(bh, "get write access");
6550 	err = ext4_journal_get_write_access(handle, bh);
6551 	if (err) {
6552 		brelse(bh);
6553 		return err;
6554 	}
6555 	lock_buffer(bh);
6556 	memcpy(bh->b_data+offset, data, len);
6557 	flush_dcache_page(bh->b_page);
6558 	unlock_buffer(bh);
6559 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6560 	brelse(bh);
6561 out:
6562 	if (inode->i_size < off + len) {
6563 		ext4_fc_track_range(inode,
6564 			(inode->i_size > 0 ? inode->i_size - 1 : 0)
6565 				>> inode->i_sb->s_blocksize_bits,
6566 			(off + len) >> inode->i_sb->s_blocksize_bits);
6567 		i_size_write(inode, off + len);
6568 		EXT4_I(inode)->i_disksize = inode->i_size;
6569 		err2 = ext4_mark_inode_dirty(handle, inode);
6570 		if (unlikely(err2 && !err))
6571 			err = err2;
6572 	}
6573 	return err ? err : len;
6574 }
6575 #endif
6576 
6577 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6578 		       const char *dev_name, void *data)
6579 {
6580 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6581 }
6582 
6583 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6584 static inline void register_as_ext2(void)
6585 {
6586 	int err = register_filesystem(&ext2_fs_type);
6587 	if (err)
6588 		printk(KERN_WARNING
6589 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6590 }
6591 
6592 static inline void unregister_as_ext2(void)
6593 {
6594 	unregister_filesystem(&ext2_fs_type);
6595 }
6596 
6597 static inline int ext2_feature_set_ok(struct super_block *sb)
6598 {
6599 	if (ext4_has_unknown_ext2_incompat_features(sb))
6600 		return 0;
6601 	if (sb_rdonly(sb))
6602 		return 1;
6603 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6604 		return 0;
6605 	return 1;
6606 }
6607 #else
6608 static inline void register_as_ext2(void) { }
6609 static inline void unregister_as_ext2(void) { }
6610 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6611 #endif
6612 
6613 static inline void register_as_ext3(void)
6614 {
6615 	int err = register_filesystem(&ext3_fs_type);
6616 	if (err)
6617 		printk(KERN_WARNING
6618 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6619 }
6620 
6621 static inline void unregister_as_ext3(void)
6622 {
6623 	unregister_filesystem(&ext3_fs_type);
6624 }
6625 
6626 static inline int ext3_feature_set_ok(struct super_block *sb)
6627 {
6628 	if (ext4_has_unknown_ext3_incompat_features(sb))
6629 		return 0;
6630 	if (!ext4_has_feature_journal(sb))
6631 		return 0;
6632 	if (sb_rdonly(sb))
6633 		return 1;
6634 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6635 		return 0;
6636 	return 1;
6637 }
6638 
6639 static struct file_system_type ext4_fs_type = {
6640 	.owner		= THIS_MODULE,
6641 	.name		= "ext4",
6642 	.mount		= ext4_mount,
6643 	.kill_sb	= kill_block_super,
6644 	.fs_flags	= FS_REQUIRES_DEV,
6645 };
6646 MODULE_ALIAS_FS("ext4");
6647 
6648 /* Shared across all ext4 file systems */
6649 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6650 
6651 static int __init ext4_init_fs(void)
6652 {
6653 	int i, err;
6654 
6655 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6656 	ext4_li_info = NULL;
6657 	mutex_init(&ext4_li_mtx);
6658 
6659 	/* Build-time check for flags consistency */
6660 	ext4_check_flag_values();
6661 
6662 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6663 		init_waitqueue_head(&ext4__ioend_wq[i]);
6664 
6665 	err = ext4_init_es();
6666 	if (err)
6667 		return err;
6668 
6669 	err = ext4_init_pending();
6670 	if (err)
6671 		goto out7;
6672 
6673 	err = ext4_init_post_read_processing();
6674 	if (err)
6675 		goto out6;
6676 
6677 	err = ext4_init_pageio();
6678 	if (err)
6679 		goto out5;
6680 
6681 	err = ext4_init_system_zone();
6682 	if (err)
6683 		goto out4;
6684 
6685 	err = ext4_init_sysfs();
6686 	if (err)
6687 		goto out3;
6688 
6689 	err = ext4_init_mballoc();
6690 	if (err)
6691 		goto out2;
6692 	err = init_inodecache();
6693 	if (err)
6694 		goto out1;
6695 
6696 	err = ext4_fc_init_dentry_cache();
6697 	if (err)
6698 		goto out05;
6699 
6700 	register_as_ext3();
6701 	register_as_ext2();
6702 	err = register_filesystem(&ext4_fs_type);
6703 	if (err)
6704 		goto out;
6705 
6706 	return 0;
6707 out:
6708 	unregister_as_ext2();
6709 	unregister_as_ext3();
6710 out05:
6711 	destroy_inodecache();
6712 out1:
6713 	ext4_exit_mballoc();
6714 out2:
6715 	ext4_exit_sysfs();
6716 out3:
6717 	ext4_exit_system_zone();
6718 out4:
6719 	ext4_exit_pageio();
6720 out5:
6721 	ext4_exit_post_read_processing();
6722 out6:
6723 	ext4_exit_pending();
6724 out7:
6725 	ext4_exit_es();
6726 
6727 	return err;
6728 }
6729 
6730 static void __exit ext4_exit_fs(void)
6731 {
6732 	ext4_destroy_lazyinit_thread();
6733 	unregister_as_ext2();
6734 	unregister_as_ext3();
6735 	unregister_filesystem(&ext4_fs_type);
6736 	destroy_inodecache();
6737 	ext4_exit_mballoc();
6738 	ext4_exit_sysfs();
6739 	ext4_exit_system_zone();
6740 	ext4_exit_pageio();
6741 	ext4_exit_post_read_processing();
6742 	ext4_exit_es();
6743 	ext4_exit_pending();
6744 }
6745 
6746 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6747 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6748 MODULE_LICENSE("GPL");
6749 MODULE_SOFTDEP("pre: crc32c");
6750 module_init(ext4_init_fs)
6751 module_exit(ext4_exit_fs)
6752