xref: /openbmc/linux/fs/ext4/super.c (revision 64a38367b45015de42521c4835541f43838caf39)
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 	es->s_checksum = ext4_superblock_csum(sb, es);
293 }
294 
295 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
296 			       struct ext4_group_desc *bg)
297 {
298 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
299 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
300 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
301 }
302 
303 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
304 			       struct ext4_group_desc *bg)
305 {
306 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
307 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
308 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
309 }
310 
311 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
312 			      struct ext4_group_desc *bg)
313 {
314 	return le32_to_cpu(bg->bg_inode_table_lo) |
315 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
316 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
317 }
318 
319 __u32 ext4_free_group_clusters(struct super_block *sb,
320 			       struct ext4_group_desc *bg)
321 {
322 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
323 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
324 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
325 }
326 
327 __u32 ext4_free_inodes_count(struct super_block *sb,
328 			      struct ext4_group_desc *bg)
329 {
330 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
331 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
332 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
333 }
334 
335 __u32 ext4_used_dirs_count(struct super_block *sb,
336 			      struct ext4_group_desc *bg)
337 {
338 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
339 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
340 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
341 }
342 
343 __u32 ext4_itable_unused_count(struct super_block *sb,
344 			      struct ext4_group_desc *bg)
345 {
346 	return le16_to_cpu(bg->bg_itable_unused_lo) |
347 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
348 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
349 }
350 
351 void ext4_block_bitmap_set(struct super_block *sb,
352 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
353 {
354 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
355 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
356 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
357 }
358 
359 void ext4_inode_bitmap_set(struct super_block *sb,
360 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
361 {
362 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
363 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
364 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
365 }
366 
367 void ext4_inode_table_set(struct super_block *sb,
368 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
369 {
370 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
371 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
372 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
373 }
374 
375 void ext4_free_group_clusters_set(struct super_block *sb,
376 				  struct ext4_group_desc *bg, __u32 count)
377 {
378 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
379 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
380 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
381 }
382 
383 void ext4_free_inodes_set(struct super_block *sb,
384 			  struct ext4_group_desc *bg, __u32 count)
385 {
386 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
387 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
388 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
389 }
390 
391 void ext4_used_dirs_set(struct super_block *sb,
392 			  struct ext4_group_desc *bg, __u32 count)
393 {
394 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
395 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
396 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
397 }
398 
399 void ext4_itable_unused_set(struct super_block *sb,
400 			  struct ext4_group_desc *bg, __u32 count)
401 {
402 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
403 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
404 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
405 }
406 
407 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
408 {
409 	time64_t now = ktime_get_real_seconds();
410 
411 	now = clamp_val(now, 0, (1ull << 40) - 1);
412 
413 	*lo = cpu_to_le32(lower_32_bits(now));
414 	*hi = upper_32_bits(now);
415 }
416 
417 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
418 {
419 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
420 }
421 #define ext4_update_tstamp(es, tstamp) \
422 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
423 #define ext4_get_tstamp(es, tstamp) \
424 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
425 
426 static void __save_error_info(struct super_block *sb, int error,
427 			      __u32 ino, __u64 block,
428 			      const char *func, unsigned int line)
429 {
430 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
431 	int err;
432 
433 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
434 	if (bdev_read_only(sb->s_bdev))
435 		return;
436 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
437 	ext4_update_tstamp(es, s_last_error_time);
438 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
439 	es->s_last_error_line = cpu_to_le32(line);
440 	es->s_last_error_ino = cpu_to_le32(ino);
441 	es->s_last_error_block = cpu_to_le64(block);
442 	switch (error) {
443 	case EIO:
444 		err = EXT4_ERR_EIO;
445 		break;
446 	case ENOMEM:
447 		err = EXT4_ERR_ENOMEM;
448 		break;
449 	case EFSBADCRC:
450 		err = EXT4_ERR_EFSBADCRC;
451 		break;
452 	case 0:
453 	case EFSCORRUPTED:
454 		err = EXT4_ERR_EFSCORRUPTED;
455 		break;
456 	case ENOSPC:
457 		err = EXT4_ERR_ENOSPC;
458 		break;
459 	case ENOKEY:
460 		err = EXT4_ERR_ENOKEY;
461 		break;
462 	case EROFS:
463 		err = EXT4_ERR_EROFS;
464 		break;
465 	case EFBIG:
466 		err = EXT4_ERR_EFBIG;
467 		break;
468 	case EEXIST:
469 		err = EXT4_ERR_EEXIST;
470 		break;
471 	case ERANGE:
472 		err = EXT4_ERR_ERANGE;
473 		break;
474 	case EOVERFLOW:
475 		err = EXT4_ERR_EOVERFLOW;
476 		break;
477 	case EBUSY:
478 		err = EXT4_ERR_EBUSY;
479 		break;
480 	case ENOTDIR:
481 		err = EXT4_ERR_ENOTDIR;
482 		break;
483 	case ENOTEMPTY:
484 		err = EXT4_ERR_ENOTEMPTY;
485 		break;
486 	case ESHUTDOWN:
487 		err = EXT4_ERR_ESHUTDOWN;
488 		break;
489 	case EFAULT:
490 		err = EXT4_ERR_EFAULT;
491 		break;
492 	default:
493 		err = EXT4_ERR_UNKNOWN;
494 	}
495 	es->s_last_error_errcode = err;
496 	if (!es->s_first_error_time) {
497 		es->s_first_error_time = es->s_last_error_time;
498 		es->s_first_error_time_hi = es->s_last_error_time_hi;
499 		strncpy(es->s_first_error_func, func,
500 			sizeof(es->s_first_error_func));
501 		es->s_first_error_line = cpu_to_le32(line);
502 		es->s_first_error_ino = es->s_last_error_ino;
503 		es->s_first_error_block = es->s_last_error_block;
504 		es->s_first_error_errcode = es->s_last_error_errcode;
505 	}
506 	/*
507 	 * Start the daily error reporting function if it hasn't been
508 	 * started already
509 	 */
510 	if (!es->s_error_count)
511 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
512 	le32_add_cpu(&es->s_error_count, 1);
513 }
514 
515 static void save_error_info(struct super_block *sb, int error,
516 			    __u32 ino, __u64 block,
517 			    const char *func, unsigned int line)
518 {
519 	__save_error_info(sb, error, ino, block, func, line);
520 	if (!bdev_read_only(sb->s_bdev))
521 		ext4_commit_super(sb, 1);
522 }
523 
524 /*
525  * The del_gendisk() function uninitializes the disk-specific data
526  * structures, including the bdi structure, without telling anyone
527  * else.  Once this happens, any attempt to call mark_buffer_dirty()
528  * (for example, by ext4_commit_super), will cause a kernel OOPS.
529  * This is a kludge to prevent these oops until we can put in a proper
530  * hook in del_gendisk() to inform the VFS and file system layers.
531  */
532 static int block_device_ejected(struct super_block *sb)
533 {
534 	struct inode *bd_inode = sb->s_bdev->bd_inode;
535 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
536 
537 	return bdi->dev == NULL;
538 }
539 
540 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
541 {
542 	struct super_block		*sb = journal->j_private;
543 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
544 	int				error = is_journal_aborted(journal);
545 	struct ext4_journal_cb_entry	*jce;
546 
547 	BUG_ON(txn->t_state == T_FINISHED);
548 
549 	ext4_process_freed_data(sb, txn->t_tid);
550 
551 	spin_lock(&sbi->s_md_lock);
552 	while (!list_empty(&txn->t_private_list)) {
553 		jce = list_entry(txn->t_private_list.next,
554 				 struct ext4_journal_cb_entry, jce_list);
555 		list_del_init(&jce->jce_list);
556 		spin_unlock(&sbi->s_md_lock);
557 		jce->jce_func(sb, jce, error);
558 		spin_lock(&sbi->s_md_lock);
559 	}
560 	spin_unlock(&sbi->s_md_lock);
561 }
562 
563 /*
564  * This writepage callback for write_cache_pages()
565  * takes care of a few cases after page cleaning.
566  *
567  * write_cache_pages() already checks for dirty pages
568  * and calls clear_page_dirty_for_io(), which we want,
569  * to write protect the pages.
570  *
571  * However, we may have to redirty a page (see below.)
572  */
573 static int ext4_journalled_writepage_callback(struct page *page,
574 					      struct writeback_control *wbc,
575 					      void *data)
576 {
577 	transaction_t *transaction = (transaction_t *) data;
578 	struct buffer_head *bh, *head;
579 	struct journal_head *jh;
580 
581 	bh = head = page_buffers(page);
582 	do {
583 		/*
584 		 * We have to redirty a page in these cases:
585 		 * 1) If buffer is dirty, it means the page was dirty because it
586 		 * contains a buffer that needs checkpointing. So the dirty bit
587 		 * needs to be preserved so that checkpointing writes the buffer
588 		 * properly.
589 		 * 2) If buffer is not part of the committing transaction
590 		 * (we may have just accidentally come across this buffer because
591 		 * inode range tracking is not exact) or if the currently running
592 		 * transaction already contains this buffer as well, dirty bit
593 		 * needs to be preserved so that the buffer gets writeprotected
594 		 * properly on running transaction's commit.
595 		 */
596 		jh = bh2jh(bh);
597 		if (buffer_dirty(bh) ||
598 		    (jh && (jh->b_transaction != transaction ||
599 			    jh->b_next_transaction))) {
600 			redirty_page_for_writepage(wbc, page);
601 			goto out;
602 		}
603 	} while ((bh = bh->b_this_page) != head);
604 
605 out:
606 	return AOP_WRITEPAGE_ACTIVATE;
607 }
608 
609 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
610 {
611 	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
612 	struct writeback_control wbc = {
613 		.sync_mode =  WB_SYNC_ALL,
614 		.nr_to_write = LONG_MAX,
615 		.range_start = jinode->i_dirty_start,
616 		.range_end = jinode->i_dirty_end,
617         };
618 
619 	return write_cache_pages(mapping, &wbc,
620 				 ext4_journalled_writepage_callback,
621 				 jinode->i_transaction);
622 }
623 
624 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
625 {
626 	int ret;
627 
628 	if (ext4_should_journal_data(jinode->i_vfs_inode))
629 		ret = ext4_journalled_submit_inode_data_buffers(jinode);
630 	else
631 		ret = jbd2_journal_submit_inode_data_buffers(jinode);
632 
633 	return ret;
634 }
635 
636 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
637 {
638 	int ret = 0;
639 
640 	if (!ext4_should_journal_data(jinode->i_vfs_inode))
641 		ret = jbd2_journal_finish_inode_data_buffers(jinode);
642 
643 	return ret;
644 }
645 
646 static bool system_going_down(void)
647 {
648 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
649 		|| system_state == SYSTEM_RESTART;
650 }
651 
652 /* Deal with the reporting of failure conditions on a filesystem such as
653  * inconsistencies detected or read IO failures.
654  *
655  * On ext2, we can store the error state of the filesystem in the
656  * superblock.  That is not possible on ext4, because we may have other
657  * write ordering constraints on the superblock which prevent us from
658  * writing it out straight away; and given that the journal is about to
659  * be aborted, we can't rely on the current, or future, transactions to
660  * write out the superblock safely.
661  *
662  * We'll just use the jbd2_journal_abort() error code to record an error in
663  * the journal instead.  On recovery, the journal will complain about
664  * that error until we've noted it down and cleared it.
665  */
666 
667 static void ext4_handle_error(struct super_block *sb)
668 {
669 	if (test_opt(sb, WARN_ON_ERROR))
670 		WARN_ON_ONCE(1);
671 
672 	if (sb_rdonly(sb))
673 		return;
674 
675 	if (!test_opt(sb, ERRORS_CONT)) {
676 		journal_t *journal = EXT4_SB(sb)->s_journal;
677 
678 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
679 		if (journal)
680 			jbd2_journal_abort(journal, -EIO);
681 	}
682 	/*
683 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
684 	 * could panic during 'reboot -f' as the underlying device got already
685 	 * disabled.
686 	 */
687 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
688 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
689 		/*
690 		 * Make sure updated value of ->s_mount_flags will be visible
691 		 * before ->s_flags update
692 		 */
693 		smp_wmb();
694 		sb->s_flags |= SB_RDONLY;
695 	} else if (test_opt(sb, ERRORS_PANIC)) {
696 		panic("EXT4-fs (device %s): panic forced after error\n",
697 			sb->s_id);
698 	}
699 }
700 
701 #define ext4_error_ratelimit(sb)					\
702 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
703 			     "EXT4-fs error")
704 
705 void __ext4_error(struct super_block *sb, const char *function,
706 		  unsigned int line, int error, __u64 block,
707 		  const char *fmt, ...)
708 {
709 	struct va_format vaf;
710 	va_list args;
711 
712 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
713 		return;
714 
715 	trace_ext4_error(sb, function, line);
716 	if (ext4_error_ratelimit(sb)) {
717 		va_start(args, fmt);
718 		vaf.fmt = fmt;
719 		vaf.va = &args;
720 		printk(KERN_CRIT
721 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
722 		       sb->s_id, function, line, current->comm, &vaf);
723 		va_end(args);
724 	}
725 	save_error_info(sb, error, 0, block, function, line);
726 	ext4_handle_error(sb);
727 }
728 
729 void __ext4_error_inode(struct inode *inode, const char *function,
730 			unsigned int line, ext4_fsblk_t block, int error,
731 			const char *fmt, ...)
732 {
733 	va_list args;
734 	struct va_format vaf;
735 
736 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
737 		return;
738 
739 	trace_ext4_error(inode->i_sb, function, line);
740 	if (ext4_error_ratelimit(inode->i_sb)) {
741 		va_start(args, fmt);
742 		vaf.fmt = fmt;
743 		vaf.va = &args;
744 		if (block)
745 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
746 			       "inode #%lu: block %llu: comm %s: %pV\n",
747 			       inode->i_sb->s_id, function, line, inode->i_ino,
748 			       block, current->comm, &vaf);
749 		else
750 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
751 			       "inode #%lu: comm %s: %pV\n",
752 			       inode->i_sb->s_id, function, line, inode->i_ino,
753 			       current->comm, &vaf);
754 		va_end(args);
755 	}
756 	save_error_info(inode->i_sb, error, inode->i_ino, block,
757 			function, line);
758 	ext4_handle_error(inode->i_sb);
759 }
760 
761 void __ext4_error_file(struct file *file, const char *function,
762 		       unsigned int line, ext4_fsblk_t block,
763 		       const char *fmt, ...)
764 {
765 	va_list args;
766 	struct va_format vaf;
767 	struct inode *inode = file_inode(file);
768 	char pathname[80], *path;
769 
770 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
771 		return;
772 
773 	trace_ext4_error(inode->i_sb, function, line);
774 	if (ext4_error_ratelimit(inode->i_sb)) {
775 		path = file_path(file, pathname, sizeof(pathname));
776 		if (IS_ERR(path))
777 			path = "(unknown)";
778 		va_start(args, fmt);
779 		vaf.fmt = fmt;
780 		vaf.va = &args;
781 		if (block)
782 			printk(KERN_CRIT
783 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
784 			       "block %llu: comm %s: path %s: %pV\n",
785 			       inode->i_sb->s_id, function, line, inode->i_ino,
786 			       block, current->comm, path, &vaf);
787 		else
788 			printk(KERN_CRIT
789 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
790 			       "comm %s: path %s: %pV\n",
791 			       inode->i_sb->s_id, function, line, inode->i_ino,
792 			       current->comm, path, &vaf);
793 		va_end(args);
794 	}
795 	save_error_info(inode->i_sb, EFSCORRUPTED, inode->i_ino, block,
796 			function, line);
797 	ext4_handle_error(inode->i_sb);
798 }
799 
800 const char *ext4_decode_error(struct super_block *sb, int errno,
801 			      char nbuf[16])
802 {
803 	char *errstr = NULL;
804 
805 	switch (errno) {
806 	case -EFSCORRUPTED:
807 		errstr = "Corrupt filesystem";
808 		break;
809 	case -EFSBADCRC:
810 		errstr = "Filesystem failed CRC";
811 		break;
812 	case -EIO:
813 		errstr = "IO failure";
814 		break;
815 	case -ENOMEM:
816 		errstr = "Out of memory";
817 		break;
818 	case -EROFS:
819 		if (!sb || (EXT4_SB(sb)->s_journal &&
820 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
821 			errstr = "Journal has aborted";
822 		else
823 			errstr = "Readonly filesystem";
824 		break;
825 	default:
826 		/* If the caller passed in an extra buffer for unknown
827 		 * errors, textualise them now.  Else we just return
828 		 * NULL. */
829 		if (nbuf) {
830 			/* Check for truncated error codes... */
831 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
832 				errstr = nbuf;
833 		}
834 		break;
835 	}
836 
837 	return errstr;
838 }
839 
840 /* __ext4_std_error decodes expected errors from journaling functions
841  * automatically and invokes the appropriate error response.  */
842 
843 void __ext4_std_error(struct super_block *sb, const char *function,
844 		      unsigned int line, int errno)
845 {
846 	char nbuf[16];
847 	const char *errstr;
848 
849 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
850 		return;
851 
852 	/* Special case: if the error is EROFS, and we're not already
853 	 * inside a transaction, then there's really no point in logging
854 	 * an error. */
855 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
856 		return;
857 
858 	if (ext4_error_ratelimit(sb)) {
859 		errstr = ext4_decode_error(sb, errno, nbuf);
860 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
861 		       sb->s_id, function, line, errstr);
862 	}
863 
864 	save_error_info(sb, -errno, 0, 0, function, line);
865 	ext4_handle_error(sb);
866 }
867 
868 /*
869  * ext4_abort is a much stronger failure handler than ext4_error.  The
870  * abort function may be used to deal with unrecoverable failures such
871  * as journal IO errors or ENOMEM at a critical moment in log management.
872  *
873  * We unconditionally force the filesystem into an ABORT|READONLY state,
874  * unless the error response on the fs has been set to panic in which
875  * case we take the easy way out and panic immediately.
876  */
877 
878 void __ext4_abort(struct super_block *sb, const char *function,
879 		  unsigned int line, int error, const char *fmt, ...)
880 {
881 	struct va_format vaf;
882 	va_list args;
883 
884 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
885 		return;
886 
887 	save_error_info(sb, error, 0, 0, function, line);
888 	va_start(args, fmt);
889 	vaf.fmt = fmt;
890 	vaf.va = &args;
891 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
892 	       sb->s_id, function, line, &vaf);
893 	va_end(args);
894 
895 	if (sb_rdonly(sb) == 0) {
896 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
897 		if (EXT4_SB(sb)->s_journal)
898 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
899 
900 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
901 		/*
902 		 * Make sure updated value of ->s_mount_flags will be visible
903 		 * before ->s_flags update
904 		 */
905 		smp_wmb();
906 		sb->s_flags |= SB_RDONLY;
907 	}
908 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down())
909 		panic("EXT4-fs panic from previous error\n");
910 }
911 
912 void __ext4_msg(struct super_block *sb,
913 		const char *prefix, const char *fmt, ...)
914 {
915 	struct va_format vaf;
916 	va_list args;
917 
918 	atomic_inc(&EXT4_SB(sb)->s_msg_count);
919 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
920 		return;
921 
922 	va_start(args, fmt);
923 	vaf.fmt = fmt;
924 	vaf.va = &args;
925 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
926 	va_end(args);
927 }
928 
929 static int ext4_warning_ratelimit(struct super_block *sb)
930 {
931 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
932 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
933 			    "EXT4-fs warning");
934 }
935 
936 void __ext4_warning(struct super_block *sb, const char *function,
937 		    unsigned int line, const char *fmt, ...)
938 {
939 	struct va_format vaf;
940 	va_list args;
941 
942 	if (!ext4_warning_ratelimit(sb))
943 		return;
944 
945 	va_start(args, fmt);
946 	vaf.fmt = fmt;
947 	vaf.va = &args;
948 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
949 	       sb->s_id, function, line, &vaf);
950 	va_end(args);
951 }
952 
953 void __ext4_warning_inode(const struct inode *inode, const char *function,
954 			  unsigned int line, const char *fmt, ...)
955 {
956 	struct va_format vaf;
957 	va_list args;
958 
959 	if (!ext4_warning_ratelimit(inode->i_sb))
960 		return;
961 
962 	va_start(args, fmt);
963 	vaf.fmt = fmt;
964 	vaf.va = &args;
965 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
966 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
967 	       function, line, inode->i_ino, current->comm, &vaf);
968 	va_end(args);
969 }
970 
971 void __ext4_grp_locked_error(const char *function, unsigned int line,
972 			     struct super_block *sb, ext4_group_t grp,
973 			     unsigned long ino, ext4_fsblk_t block,
974 			     const char *fmt, ...)
975 __releases(bitlock)
976 __acquires(bitlock)
977 {
978 	struct va_format vaf;
979 	va_list args;
980 
981 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
982 		return;
983 
984 	trace_ext4_error(sb, function, line);
985 	__save_error_info(sb, EFSCORRUPTED, ino, block, function, line);
986 
987 	if (ext4_error_ratelimit(sb)) {
988 		va_start(args, fmt);
989 		vaf.fmt = fmt;
990 		vaf.va = &args;
991 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
992 		       sb->s_id, function, line, grp);
993 		if (ino)
994 			printk(KERN_CONT "inode %lu: ", ino);
995 		if (block)
996 			printk(KERN_CONT "block %llu:",
997 			       (unsigned long long) block);
998 		printk(KERN_CONT "%pV\n", &vaf);
999 		va_end(args);
1000 	}
1001 
1002 	if (test_opt(sb, WARN_ON_ERROR))
1003 		WARN_ON_ONCE(1);
1004 
1005 	if (test_opt(sb, ERRORS_CONT)) {
1006 		ext4_commit_super(sb, 0);
1007 		return;
1008 	}
1009 
1010 	ext4_unlock_group(sb, grp);
1011 	ext4_commit_super(sb, 1);
1012 	ext4_handle_error(sb);
1013 	/*
1014 	 * We only get here in the ERRORS_RO case; relocking the group
1015 	 * may be dangerous, but nothing bad will happen since the
1016 	 * filesystem will have already been marked read/only and the
1017 	 * journal has been aborted.  We return 1 as a hint to callers
1018 	 * who might what to use the return value from
1019 	 * ext4_grp_locked_error() to distinguish between the
1020 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1021 	 * aggressively from the ext4 function in question, with a
1022 	 * more appropriate error code.
1023 	 */
1024 	ext4_lock_group(sb, grp);
1025 	return;
1026 }
1027 
1028 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1029 				     ext4_group_t group,
1030 				     unsigned int flags)
1031 {
1032 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1033 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1034 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1035 	int ret;
1036 
1037 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1038 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1039 					    &grp->bb_state);
1040 		if (!ret)
1041 			percpu_counter_sub(&sbi->s_freeclusters_counter,
1042 					   grp->bb_free);
1043 	}
1044 
1045 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1046 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1047 					    &grp->bb_state);
1048 		if (!ret && gdp) {
1049 			int count;
1050 
1051 			count = ext4_free_inodes_count(sb, gdp);
1052 			percpu_counter_sub(&sbi->s_freeinodes_counter,
1053 					   count);
1054 		}
1055 	}
1056 }
1057 
1058 void ext4_update_dynamic_rev(struct super_block *sb)
1059 {
1060 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1061 
1062 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1063 		return;
1064 
1065 	ext4_warning(sb,
1066 		     "updating to rev %d because of new feature flag, "
1067 		     "running e2fsck is recommended",
1068 		     EXT4_DYNAMIC_REV);
1069 
1070 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1071 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1072 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1073 	/* leave es->s_feature_*compat flags alone */
1074 	/* es->s_uuid will be set by e2fsck if empty */
1075 
1076 	/*
1077 	 * The rest of the superblock fields should be zero, and if not it
1078 	 * means they are likely already in use, so leave them alone.  We
1079 	 * can leave it up to e2fsck to clean up any inconsistencies there.
1080 	 */
1081 }
1082 
1083 /*
1084  * Open the external journal device
1085  */
1086 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1087 {
1088 	struct block_device *bdev;
1089 
1090 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1091 	if (IS_ERR(bdev))
1092 		goto fail;
1093 	return bdev;
1094 
1095 fail:
1096 	ext4_msg(sb, KERN_ERR,
1097 		 "failed to open journal device unknown-block(%u,%u) %ld",
1098 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1099 	return NULL;
1100 }
1101 
1102 /*
1103  * Release the journal device
1104  */
1105 static void ext4_blkdev_put(struct block_device *bdev)
1106 {
1107 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1108 }
1109 
1110 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1111 {
1112 	struct block_device *bdev;
1113 	bdev = sbi->s_journal_bdev;
1114 	if (bdev) {
1115 		ext4_blkdev_put(bdev);
1116 		sbi->s_journal_bdev = NULL;
1117 	}
1118 }
1119 
1120 static inline struct inode *orphan_list_entry(struct list_head *l)
1121 {
1122 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1123 }
1124 
1125 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1126 {
1127 	struct list_head *l;
1128 
1129 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1130 		 le32_to_cpu(sbi->s_es->s_last_orphan));
1131 
1132 	printk(KERN_ERR "sb_info orphan list:\n");
1133 	list_for_each(l, &sbi->s_orphan) {
1134 		struct inode *inode = orphan_list_entry(l);
1135 		printk(KERN_ERR "  "
1136 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1137 		       inode->i_sb->s_id, inode->i_ino, inode,
1138 		       inode->i_mode, inode->i_nlink,
1139 		       NEXT_ORPHAN(inode));
1140 	}
1141 }
1142 
1143 #ifdef CONFIG_QUOTA
1144 static int ext4_quota_off(struct super_block *sb, int type);
1145 
1146 static inline void ext4_quota_off_umount(struct super_block *sb)
1147 {
1148 	int type;
1149 
1150 	/* Use our quota_off function to clear inode flags etc. */
1151 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
1152 		ext4_quota_off(sb, type);
1153 }
1154 
1155 /*
1156  * This is a helper function which is used in the mount/remount
1157  * codepaths (which holds s_umount) to fetch the quota file name.
1158  */
1159 static inline char *get_qf_name(struct super_block *sb,
1160 				struct ext4_sb_info *sbi,
1161 				int type)
1162 {
1163 	return rcu_dereference_protected(sbi->s_qf_names[type],
1164 					 lockdep_is_held(&sb->s_umount));
1165 }
1166 #else
1167 static inline void ext4_quota_off_umount(struct super_block *sb)
1168 {
1169 }
1170 #endif
1171 
1172 static void ext4_put_super(struct super_block *sb)
1173 {
1174 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1175 	struct ext4_super_block *es = sbi->s_es;
1176 	struct buffer_head **group_desc;
1177 	struct flex_groups **flex_groups;
1178 	int aborted = 0;
1179 	int i, err;
1180 
1181 	ext4_unregister_li_request(sb);
1182 	ext4_quota_off_umount(sb);
1183 
1184 	destroy_workqueue(sbi->rsv_conversion_wq);
1185 
1186 	/*
1187 	 * Unregister sysfs before destroying jbd2 journal.
1188 	 * Since we could still access attr_journal_task attribute via sysfs
1189 	 * path which could have sbi->s_journal->j_task as NULL
1190 	 */
1191 	ext4_unregister_sysfs(sb);
1192 
1193 	if (sbi->s_journal) {
1194 		aborted = is_journal_aborted(sbi->s_journal);
1195 		err = jbd2_journal_destroy(sbi->s_journal);
1196 		sbi->s_journal = NULL;
1197 		if ((err < 0) && !aborted) {
1198 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1199 		}
1200 	}
1201 
1202 	ext4_es_unregister_shrinker(sbi);
1203 	del_timer_sync(&sbi->s_err_report);
1204 	ext4_release_system_zone(sb);
1205 	ext4_mb_release(sb);
1206 	ext4_ext_release(sb);
1207 
1208 	if (!sb_rdonly(sb) && !aborted) {
1209 		ext4_clear_feature_journal_needs_recovery(sb);
1210 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1211 	}
1212 	if (!sb_rdonly(sb))
1213 		ext4_commit_super(sb, 1);
1214 
1215 	rcu_read_lock();
1216 	group_desc = rcu_dereference(sbi->s_group_desc);
1217 	for (i = 0; i < sbi->s_gdb_count; i++)
1218 		brelse(group_desc[i]);
1219 	kvfree(group_desc);
1220 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1221 	if (flex_groups) {
1222 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1223 			kvfree(flex_groups[i]);
1224 		kvfree(flex_groups);
1225 	}
1226 	rcu_read_unlock();
1227 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1228 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1229 	percpu_counter_destroy(&sbi->s_dirs_counter);
1230 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1231 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1232 #ifdef CONFIG_QUOTA
1233 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1234 		kfree(get_qf_name(sb, sbi, i));
1235 #endif
1236 
1237 	/* Debugging code just in case the in-memory inode orphan list
1238 	 * isn't empty.  The on-disk one can be non-empty if we've
1239 	 * detected an error and taken the fs readonly, but the
1240 	 * in-memory list had better be clean by this point. */
1241 	if (!list_empty(&sbi->s_orphan))
1242 		dump_orphan_list(sb, sbi);
1243 	J_ASSERT(list_empty(&sbi->s_orphan));
1244 
1245 	sync_blockdev(sb->s_bdev);
1246 	invalidate_bdev(sb->s_bdev);
1247 	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1248 		/*
1249 		 * Invalidate the journal device's buffers.  We don't want them
1250 		 * floating about in memory - the physical journal device may
1251 		 * hotswapped, and it breaks the `ro-after' testing code.
1252 		 */
1253 		sync_blockdev(sbi->s_journal_bdev);
1254 		invalidate_bdev(sbi->s_journal_bdev);
1255 		ext4_blkdev_remove(sbi);
1256 	}
1257 
1258 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1259 	sbi->s_ea_inode_cache = NULL;
1260 
1261 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1262 	sbi->s_ea_block_cache = NULL;
1263 
1264 	if (sbi->s_mmp_tsk)
1265 		kthread_stop(sbi->s_mmp_tsk);
1266 	brelse(sbi->s_sbh);
1267 	sb->s_fs_info = NULL;
1268 	/*
1269 	 * Now that we are completely done shutting down the
1270 	 * superblock, we need to actually destroy the kobject.
1271 	 */
1272 	kobject_put(&sbi->s_kobj);
1273 	wait_for_completion(&sbi->s_kobj_unregister);
1274 	if (sbi->s_chksum_driver)
1275 		crypto_free_shash(sbi->s_chksum_driver);
1276 	kfree(sbi->s_blockgroup_lock);
1277 	fs_put_dax(sbi->s_daxdev);
1278 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1279 #ifdef CONFIG_UNICODE
1280 	utf8_unload(sb->s_encoding);
1281 #endif
1282 	kfree(sbi);
1283 }
1284 
1285 static struct kmem_cache *ext4_inode_cachep;
1286 
1287 /*
1288  * Called inside transaction, so use GFP_NOFS
1289  */
1290 static struct inode *ext4_alloc_inode(struct super_block *sb)
1291 {
1292 	struct ext4_inode_info *ei;
1293 
1294 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1295 	if (!ei)
1296 		return NULL;
1297 
1298 	inode_set_iversion(&ei->vfs_inode, 1);
1299 	spin_lock_init(&ei->i_raw_lock);
1300 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1301 	atomic_set(&ei->i_prealloc_active, 0);
1302 	spin_lock_init(&ei->i_prealloc_lock);
1303 	ext4_es_init_tree(&ei->i_es_tree);
1304 	rwlock_init(&ei->i_es_lock);
1305 	INIT_LIST_HEAD(&ei->i_es_list);
1306 	ei->i_es_all_nr = 0;
1307 	ei->i_es_shk_nr = 0;
1308 	ei->i_es_shrink_lblk = 0;
1309 	ei->i_reserved_data_blocks = 0;
1310 	spin_lock_init(&(ei->i_block_reservation_lock));
1311 	ext4_init_pending_tree(&ei->i_pending_tree);
1312 #ifdef CONFIG_QUOTA
1313 	ei->i_reserved_quota = 0;
1314 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1315 #endif
1316 	ei->jinode = NULL;
1317 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1318 	spin_lock_init(&ei->i_completed_io_lock);
1319 	ei->i_sync_tid = 0;
1320 	ei->i_datasync_tid = 0;
1321 	atomic_set(&ei->i_unwritten, 0);
1322 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1323 	ext4_fc_init_inode(&ei->vfs_inode);
1324 	mutex_init(&ei->i_fc_lock);
1325 	return &ei->vfs_inode;
1326 }
1327 
1328 static int ext4_drop_inode(struct inode *inode)
1329 {
1330 	int drop = generic_drop_inode(inode);
1331 
1332 	if (!drop)
1333 		drop = fscrypt_drop_inode(inode);
1334 
1335 	trace_ext4_drop_inode(inode, drop);
1336 	return drop;
1337 }
1338 
1339 static void ext4_free_in_core_inode(struct inode *inode)
1340 {
1341 	fscrypt_free_inode(inode);
1342 	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1343 		pr_warn("%s: inode %ld still in fc list",
1344 			__func__, inode->i_ino);
1345 	}
1346 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1347 }
1348 
1349 static void ext4_destroy_inode(struct inode *inode)
1350 {
1351 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1352 		ext4_msg(inode->i_sb, KERN_ERR,
1353 			 "Inode %lu (%p): orphan list check failed!",
1354 			 inode->i_ino, EXT4_I(inode));
1355 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1356 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1357 				true);
1358 		dump_stack();
1359 	}
1360 }
1361 
1362 static void init_once(void *foo)
1363 {
1364 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1365 
1366 	INIT_LIST_HEAD(&ei->i_orphan);
1367 	init_rwsem(&ei->xattr_sem);
1368 	init_rwsem(&ei->i_data_sem);
1369 	init_rwsem(&ei->i_mmap_sem);
1370 	inode_init_once(&ei->vfs_inode);
1371 	ext4_fc_init_inode(&ei->vfs_inode);
1372 }
1373 
1374 static int __init init_inodecache(void)
1375 {
1376 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1377 				sizeof(struct ext4_inode_info), 0,
1378 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1379 					SLAB_ACCOUNT),
1380 				offsetof(struct ext4_inode_info, i_data),
1381 				sizeof_field(struct ext4_inode_info, i_data),
1382 				init_once);
1383 	if (ext4_inode_cachep == NULL)
1384 		return -ENOMEM;
1385 	return 0;
1386 }
1387 
1388 static void destroy_inodecache(void)
1389 {
1390 	/*
1391 	 * Make sure all delayed rcu free inodes are flushed before we
1392 	 * destroy cache.
1393 	 */
1394 	rcu_barrier();
1395 	kmem_cache_destroy(ext4_inode_cachep);
1396 }
1397 
1398 void ext4_clear_inode(struct inode *inode)
1399 {
1400 	ext4_fc_del(inode);
1401 	invalidate_inode_buffers(inode);
1402 	clear_inode(inode);
1403 	ext4_discard_preallocations(inode, 0);
1404 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1405 	dquot_drop(inode);
1406 	if (EXT4_I(inode)->jinode) {
1407 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1408 					       EXT4_I(inode)->jinode);
1409 		jbd2_free_inode(EXT4_I(inode)->jinode);
1410 		EXT4_I(inode)->jinode = NULL;
1411 	}
1412 	fscrypt_put_encryption_info(inode);
1413 	fsverity_cleanup_inode(inode);
1414 }
1415 
1416 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1417 					u64 ino, u32 generation)
1418 {
1419 	struct inode *inode;
1420 
1421 	/*
1422 	 * Currently we don't know the generation for parent directory, so
1423 	 * a generation of 0 means "accept any"
1424 	 */
1425 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1426 	if (IS_ERR(inode))
1427 		return ERR_CAST(inode);
1428 	if (generation && inode->i_generation != generation) {
1429 		iput(inode);
1430 		return ERR_PTR(-ESTALE);
1431 	}
1432 
1433 	return inode;
1434 }
1435 
1436 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1437 					int fh_len, int fh_type)
1438 {
1439 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1440 				    ext4_nfs_get_inode);
1441 }
1442 
1443 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1444 					int fh_len, int fh_type)
1445 {
1446 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1447 				    ext4_nfs_get_inode);
1448 }
1449 
1450 static int ext4_nfs_commit_metadata(struct inode *inode)
1451 {
1452 	struct writeback_control wbc = {
1453 		.sync_mode = WB_SYNC_ALL
1454 	};
1455 
1456 	trace_ext4_nfs_commit_metadata(inode);
1457 	return ext4_write_inode(inode, &wbc);
1458 }
1459 
1460 /*
1461  * Try to release metadata pages (indirect blocks, directories) which are
1462  * mapped via the block device.  Since these pages could have journal heads
1463  * which would prevent try_to_free_buffers() from freeing them, we must use
1464  * jbd2 layer's try_to_free_buffers() function to release them.
1465  */
1466 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1467 				 gfp_t wait)
1468 {
1469 	journal_t *journal = EXT4_SB(sb)->s_journal;
1470 
1471 	WARN_ON(PageChecked(page));
1472 	if (!page_has_buffers(page))
1473 		return 0;
1474 	if (journal)
1475 		return jbd2_journal_try_to_free_buffers(journal, page);
1476 
1477 	return try_to_free_buffers(page);
1478 }
1479 
1480 #ifdef CONFIG_FS_ENCRYPTION
1481 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1482 {
1483 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1484 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1485 }
1486 
1487 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1488 							void *fs_data)
1489 {
1490 	handle_t *handle = fs_data;
1491 	int res, res2, credits, retries = 0;
1492 
1493 	/*
1494 	 * Encrypting the root directory is not allowed because e2fsck expects
1495 	 * lost+found to exist and be unencrypted, and encrypting the root
1496 	 * directory would imply encrypting the lost+found directory as well as
1497 	 * the filename "lost+found" itself.
1498 	 */
1499 	if (inode->i_ino == EXT4_ROOT_INO)
1500 		return -EPERM;
1501 
1502 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1503 		return -EINVAL;
1504 
1505 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1506 		return -EOPNOTSUPP;
1507 
1508 	res = ext4_convert_inline_data(inode);
1509 	if (res)
1510 		return res;
1511 
1512 	/*
1513 	 * If a journal handle was specified, then the encryption context is
1514 	 * being set on a new inode via inheritance and is part of a larger
1515 	 * transaction to create the inode.  Otherwise the encryption context is
1516 	 * being set on an existing inode in its own transaction.  Only in the
1517 	 * latter case should the "retry on ENOSPC" logic be used.
1518 	 */
1519 
1520 	if (handle) {
1521 		res = ext4_xattr_set_handle(handle, inode,
1522 					    EXT4_XATTR_INDEX_ENCRYPTION,
1523 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1524 					    ctx, len, 0);
1525 		if (!res) {
1526 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1527 			ext4_clear_inode_state(inode,
1528 					EXT4_STATE_MAY_INLINE_DATA);
1529 			/*
1530 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1531 			 * S_DAX may be disabled
1532 			 */
1533 			ext4_set_inode_flags(inode, false);
1534 		}
1535 		return res;
1536 	}
1537 
1538 	res = dquot_initialize(inode);
1539 	if (res)
1540 		return res;
1541 retry:
1542 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1543 				     &credits);
1544 	if (res)
1545 		return res;
1546 
1547 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1548 	if (IS_ERR(handle))
1549 		return PTR_ERR(handle);
1550 
1551 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1552 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1553 				    ctx, len, 0);
1554 	if (!res) {
1555 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1556 		/*
1557 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1558 		 * S_DAX may be disabled
1559 		 */
1560 		ext4_set_inode_flags(inode, false);
1561 		res = ext4_mark_inode_dirty(handle, inode);
1562 		if (res)
1563 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1564 	}
1565 	res2 = ext4_journal_stop(handle);
1566 
1567 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1568 		goto retry;
1569 	if (!res)
1570 		res = res2;
1571 	return res;
1572 }
1573 
1574 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1575 {
1576 	return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1577 }
1578 
1579 static bool ext4_has_stable_inodes(struct super_block *sb)
1580 {
1581 	return ext4_has_feature_stable_inodes(sb);
1582 }
1583 
1584 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1585 				       int *ino_bits_ret, int *lblk_bits_ret)
1586 {
1587 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1588 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1589 }
1590 
1591 static const struct fscrypt_operations ext4_cryptops = {
1592 	.key_prefix		= "ext4:",
1593 	.get_context		= ext4_get_context,
1594 	.set_context		= ext4_set_context,
1595 	.get_dummy_policy	= ext4_get_dummy_policy,
1596 	.empty_dir		= ext4_empty_dir,
1597 	.max_namelen		= EXT4_NAME_LEN,
1598 	.has_stable_inodes	= ext4_has_stable_inodes,
1599 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1600 };
1601 #endif
1602 
1603 #ifdef CONFIG_QUOTA
1604 static const char * const quotatypes[] = INITQFNAMES;
1605 #define QTYPE2NAME(t) (quotatypes[t])
1606 
1607 static int ext4_write_dquot(struct dquot *dquot);
1608 static int ext4_acquire_dquot(struct dquot *dquot);
1609 static int ext4_release_dquot(struct dquot *dquot);
1610 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1611 static int ext4_write_info(struct super_block *sb, int type);
1612 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1613 			 const struct path *path);
1614 static int ext4_quota_on_mount(struct super_block *sb, int type);
1615 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1616 			       size_t len, loff_t off);
1617 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1618 				const char *data, size_t len, loff_t off);
1619 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1620 			     unsigned int flags);
1621 static int ext4_enable_quotas(struct super_block *sb);
1622 
1623 static struct dquot **ext4_get_dquots(struct inode *inode)
1624 {
1625 	return EXT4_I(inode)->i_dquot;
1626 }
1627 
1628 static const struct dquot_operations ext4_quota_operations = {
1629 	.get_reserved_space	= ext4_get_reserved_space,
1630 	.write_dquot		= ext4_write_dquot,
1631 	.acquire_dquot		= ext4_acquire_dquot,
1632 	.release_dquot		= ext4_release_dquot,
1633 	.mark_dirty		= ext4_mark_dquot_dirty,
1634 	.write_info		= ext4_write_info,
1635 	.alloc_dquot		= dquot_alloc,
1636 	.destroy_dquot		= dquot_destroy,
1637 	.get_projid		= ext4_get_projid,
1638 	.get_inode_usage	= ext4_get_inode_usage,
1639 	.get_next_id		= dquot_get_next_id,
1640 };
1641 
1642 static const struct quotactl_ops ext4_qctl_operations = {
1643 	.quota_on	= ext4_quota_on,
1644 	.quota_off	= ext4_quota_off,
1645 	.quota_sync	= dquot_quota_sync,
1646 	.get_state	= dquot_get_state,
1647 	.set_info	= dquot_set_dqinfo,
1648 	.get_dqblk	= dquot_get_dqblk,
1649 	.set_dqblk	= dquot_set_dqblk,
1650 	.get_nextdqblk	= dquot_get_next_dqblk,
1651 };
1652 #endif
1653 
1654 static const struct super_operations ext4_sops = {
1655 	.alloc_inode	= ext4_alloc_inode,
1656 	.free_inode	= ext4_free_in_core_inode,
1657 	.destroy_inode	= ext4_destroy_inode,
1658 	.write_inode	= ext4_write_inode,
1659 	.dirty_inode	= ext4_dirty_inode,
1660 	.drop_inode	= ext4_drop_inode,
1661 	.evict_inode	= ext4_evict_inode,
1662 	.put_super	= ext4_put_super,
1663 	.sync_fs	= ext4_sync_fs,
1664 	.freeze_fs	= ext4_freeze,
1665 	.unfreeze_fs	= ext4_unfreeze,
1666 	.statfs		= ext4_statfs,
1667 	.remount_fs	= ext4_remount,
1668 	.show_options	= ext4_show_options,
1669 #ifdef CONFIG_QUOTA
1670 	.quota_read	= ext4_quota_read,
1671 	.quota_write	= ext4_quota_write,
1672 	.get_dquots	= ext4_get_dquots,
1673 #endif
1674 	.bdev_try_to_free_page = bdev_try_to_free_page,
1675 };
1676 
1677 static const struct export_operations ext4_export_ops = {
1678 	.fh_to_dentry = ext4_fh_to_dentry,
1679 	.fh_to_parent = ext4_fh_to_parent,
1680 	.get_parent = ext4_get_parent,
1681 	.commit_metadata = ext4_nfs_commit_metadata,
1682 };
1683 
1684 enum {
1685 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1686 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1687 	Opt_nouid32, Opt_debug, Opt_removed,
1688 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1689 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1690 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1691 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1692 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1693 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1694 	Opt_inlinecrypt,
1695 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1696 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1697 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1698 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1699 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1700 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1701 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1702 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1703 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1704 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1705 	Opt_dioread_nolock, Opt_dioread_lock,
1706 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1707 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1708 	Opt_prefetch_block_bitmaps,
1709 #ifdef CONFIG_EXT4_DEBUG
1710 	Opt_fc_debug_max_replay, Opt_fc_debug_force
1711 #endif
1712 };
1713 
1714 static const match_table_t tokens = {
1715 	{Opt_bsd_df, "bsddf"},
1716 	{Opt_minix_df, "minixdf"},
1717 	{Opt_grpid, "grpid"},
1718 	{Opt_grpid, "bsdgroups"},
1719 	{Opt_nogrpid, "nogrpid"},
1720 	{Opt_nogrpid, "sysvgroups"},
1721 	{Opt_resgid, "resgid=%u"},
1722 	{Opt_resuid, "resuid=%u"},
1723 	{Opt_sb, "sb=%u"},
1724 	{Opt_err_cont, "errors=continue"},
1725 	{Opt_err_panic, "errors=panic"},
1726 	{Opt_err_ro, "errors=remount-ro"},
1727 	{Opt_nouid32, "nouid32"},
1728 	{Opt_debug, "debug"},
1729 	{Opt_removed, "oldalloc"},
1730 	{Opt_removed, "orlov"},
1731 	{Opt_user_xattr, "user_xattr"},
1732 	{Opt_nouser_xattr, "nouser_xattr"},
1733 	{Opt_acl, "acl"},
1734 	{Opt_noacl, "noacl"},
1735 	{Opt_noload, "norecovery"},
1736 	{Opt_noload, "noload"},
1737 	{Opt_removed, "nobh"},
1738 	{Opt_removed, "bh"},
1739 	{Opt_commit, "commit=%u"},
1740 	{Opt_min_batch_time, "min_batch_time=%u"},
1741 	{Opt_max_batch_time, "max_batch_time=%u"},
1742 	{Opt_journal_dev, "journal_dev=%u"},
1743 	{Opt_journal_path, "journal_path=%s"},
1744 	{Opt_journal_checksum, "journal_checksum"},
1745 	{Opt_nojournal_checksum, "nojournal_checksum"},
1746 	{Opt_journal_async_commit, "journal_async_commit"},
1747 	{Opt_abort, "abort"},
1748 	{Opt_data_journal, "data=journal"},
1749 	{Opt_data_ordered, "data=ordered"},
1750 	{Opt_data_writeback, "data=writeback"},
1751 	{Opt_data_err_abort, "data_err=abort"},
1752 	{Opt_data_err_ignore, "data_err=ignore"},
1753 	{Opt_offusrjquota, "usrjquota="},
1754 	{Opt_usrjquota, "usrjquota=%s"},
1755 	{Opt_offgrpjquota, "grpjquota="},
1756 	{Opt_grpjquota, "grpjquota=%s"},
1757 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1758 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1759 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1760 	{Opt_grpquota, "grpquota"},
1761 	{Opt_noquota, "noquota"},
1762 	{Opt_quota, "quota"},
1763 	{Opt_usrquota, "usrquota"},
1764 	{Opt_prjquota, "prjquota"},
1765 	{Opt_barrier, "barrier=%u"},
1766 	{Opt_barrier, "barrier"},
1767 	{Opt_nobarrier, "nobarrier"},
1768 	{Opt_i_version, "i_version"},
1769 	{Opt_dax, "dax"},
1770 	{Opt_dax_always, "dax=always"},
1771 	{Opt_dax_inode, "dax=inode"},
1772 	{Opt_dax_never, "dax=never"},
1773 	{Opt_stripe, "stripe=%u"},
1774 	{Opt_delalloc, "delalloc"},
1775 	{Opt_warn_on_error, "warn_on_error"},
1776 	{Opt_nowarn_on_error, "nowarn_on_error"},
1777 	{Opt_lazytime, "lazytime"},
1778 	{Opt_nolazytime, "nolazytime"},
1779 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1780 	{Opt_nodelalloc, "nodelalloc"},
1781 	{Opt_removed, "mblk_io_submit"},
1782 	{Opt_removed, "nomblk_io_submit"},
1783 	{Opt_block_validity, "block_validity"},
1784 	{Opt_noblock_validity, "noblock_validity"},
1785 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1786 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1787 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1788 	{Opt_auto_da_alloc, "auto_da_alloc"},
1789 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1790 	{Opt_dioread_nolock, "dioread_nolock"},
1791 	{Opt_dioread_lock, "nodioread_nolock"},
1792 	{Opt_dioread_lock, "dioread_lock"},
1793 	{Opt_discard, "discard"},
1794 	{Opt_nodiscard, "nodiscard"},
1795 	{Opt_init_itable, "init_itable=%u"},
1796 	{Opt_init_itable, "init_itable"},
1797 	{Opt_noinit_itable, "noinit_itable"},
1798 #ifdef CONFIG_EXT4_DEBUG
1799 	{Opt_fc_debug_force, "fc_debug_force"},
1800 	{Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
1801 #endif
1802 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1803 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1804 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1805 	{Opt_inlinecrypt, "inlinecrypt"},
1806 	{Opt_nombcache, "nombcache"},
1807 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1808 	{Opt_prefetch_block_bitmaps, "prefetch_block_bitmaps"},
1809 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1810 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1811 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1812 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1813 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1814 	{Opt_err, NULL},
1815 };
1816 
1817 static ext4_fsblk_t get_sb_block(void **data)
1818 {
1819 	ext4_fsblk_t	sb_block;
1820 	char		*options = (char *) *data;
1821 
1822 	if (!options || strncmp(options, "sb=", 3) != 0)
1823 		return 1;	/* Default location */
1824 
1825 	options += 3;
1826 	/* TODO: use simple_strtoll with >32bit ext4 */
1827 	sb_block = simple_strtoul(options, &options, 0);
1828 	if (*options && *options != ',') {
1829 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1830 		       (char *) *data);
1831 		return 1;
1832 	}
1833 	if (*options == ',')
1834 		options++;
1835 	*data = (void *) options;
1836 
1837 	return sb_block;
1838 }
1839 
1840 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1841 static const char deprecated_msg[] =
1842 	"Mount option \"%s\" will be removed by %s\n"
1843 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1844 
1845 #ifdef CONFIG_QUOTA
1846 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1847 {
1848 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1849 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1850 	int ret = -1;
1851 
1852 	if (sb_any_quota_loaded(sb) && !old_qname) {
1853 		ext4_msg(sb, KERN_ERR,
1854 			"Cannot change journaled "
1855 			"quota options when quota turned on");
1856 		return -1;
1857 	}
1858 	if (ext4_has_feature_quota(sb)) {
1859 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1860 			 "ignored when QUOTA feature is enabled");
1861 		return 1;
1862 	}
1863 	qname = match_strdup(args);
1864 	if (!qname) {
1865 		ext4_msg(sb, KERN_ERR,
1866 			"Not enough memory for storing quotafile name");
1867 		return -1;
1868 	}
1869 	if (old_qname) {
1870 		if (strcmp(old_qname, qname) == 0)
1871 			ret = 1;
1872 		else
1873 			ext4_msg(sb, KERN_ERR,
1874 				 "%s quota file already specified",
1875 				 QTYPE2NAME(qtype));
1876 		goto errout;
1877 	}
1878 	if (strchr(qname, '/')) {
1879 		ext4_msg(sb, KERN_ERR,
1880 			"quotafile must be on filesystem root");
1881 		goto errout;
1882 	}
1883 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1884 	set_opt(sb, QUOTA);
1885 	return 1;
1886 errout:
1887 	kfree(qname);
1888 	return ret;
1889 }
1890 
1891 static int clear_qf_name(struct super_block *sb, int qtype)
1892 {
1893 
1894 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1895 	char *old_qname = get_qf_name(sb, sbi, qtype);
1896 
1897 	if (sb_any_quota_loaded(sb) && old_qname) {
1898 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1899 			" when quota turned on");
1900 		return -1;
1901 	}
1902 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1903 	synchronize_rcu();
1904 	kfree(old_qname);
1905 	return 1;
1906 }
1907 #endif
1908 
1909 #define MOPT_SET	0x0001
1910 #define MOPT_CLEAR	0x0002
1911 #define MOPT_NOSUPPORT	0x0004
1912 #define MOPT_EXPLICIT	0x0008
1913 #define MOPT_CLEAR_ERR	0x0010
1914 #define MOPT_GTE0	0x0020
1915 #ifdef CONFIG_QUOTA
1916 #define MOPT_Q		0
1917 #define MOPT_QFMT	0x0040
1918 #else
1919 #define MOPT_Q		MOPT_NOSUPPORT
1920 #define MOPT_QFMT	MOPT_NOSUPPORT
1921 #endif
1922 #define MOPT_DATAJ	0x0080
1923 #define MOPT_NO_EXT2	0x0100
1924 #define MOPT_NO_EXT3	0x0200
1925 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1926 #define MOPT_STRING	0x0400
1927 #define MOPT_SKIP	0x0800
1928 #define	MOPT_2		0x1000
1929 
1930 static const struct mount_opts {
1931 	int	token;
1932 	int	mount_opt;
1933 	int	flags;
1934 } ext4_mount_opts[] = {
1935 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1936 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1937 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1938 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1939 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1940 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1941 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1942 	 MOPT_EXT4_ONLY | MOPT_SET},
1943 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1944 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1945 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1946 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1947 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1948 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1949 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1950 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1951 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1952 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1953 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1954 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1955 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1956 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1957 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1958 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1959 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1960 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1961 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1962 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1963 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1964 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1965 	 MOPT_NO_EXT2},
1966 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1967 	 MOPT_NO_EXT2},
1968 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1969 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1970 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1971 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1972 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1973 	{Opt_commit, 0, MOPT_GTE0},
1974 	{Opt_max_batch_time, 0, MOPT_GTE0},
1975 	{Opt_min_batch_time, 0, MOPT_GTE0},
1976 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1977 	{Opt_init_itable, 0, MOPT_GTE0},
1978 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1979 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1980 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1981 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1982 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1983 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1984 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1985 	{Opt_stripe, 0, MOPT_GTE0},
1986 	{Opt_resuid, 0, MOPT_GTE0},
1987 	{Opt_resgid, 0, MOPT_GTE0},
1988 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1989 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1990 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1991 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1992 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1993 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1994 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1995 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1996 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1997 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1998 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1999 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
2000 #else
2001 	{Opt_acl, 0, MOPT_NOSUPPORT},
2002 	{Opt_noacl, 0, MOPT_NOSUPPORT},
2003 #endif
2004 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
2005 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
2006 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
2007 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
2008 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
2009 							MOPT_SET | MOPT_Q},
2010 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
2011 							MOPT_SET | MOPT_Q},
2012 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
2013 							MOPT_SET | MOPT_Q},
2014 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2015 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
2016 							MOPT_CLEAR | MOPT_Q},
2017 	{Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
2018 	{Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
2019 	{Opt_offusrjquota, 0, MOPT_Q},
2020 	{Opt_offgrpjquota, 0, MOPT_Q},
2021 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
2022 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
2023 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
2024 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
2025 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
2026 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
2027 	{Opt_prefetch_block_bitmaps, EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS,
2028 	 MOPT_SET},
2029 #ifdef CONFIG_EXT4_DEBUG
2030 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2031 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
2032 	{Opt_fc_debug_max_replay, 0, MOPT_GTE0},
2033 #endif
2034 	{Opt_err, 0, 0}
2035 };
2036 
2037 #ifdef CONFIG_UNICODE
2038 static const struct ext4_sb_encodings {
2039 	__u16 magic;
2040 	char *name;
2041 	char *version;
2042 } ext4_sb_encoding_map[] = {
2043 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
2044 };
2045 
2046 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
2047 				 const struct ext4_sb_encodings **encoding,
2048 				 __u16 *flags)
2049 {
2050 	__u16 magic = le16_to_cpu(es->s_encoding);
2051 	int i;
2052 
2053 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
2054 		if (magic == ext4_sb_encoding_map[i].magic)
2055 			break;
2056 
2057 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
2058 		return -EINVAL;
2059 
2060 	*encoding = &ext4_sb_encoding_map[i];
2061 	*flags = le16_to_cpu(es->s_encoding_flags);
2062 
2063 	return 0;
2064 }
2065 #endif
2066 
2067 static int ext4_set_test_dummy_encryption(struct super_block *sb,
2068 					  const char *opt,
2069 					  const substring_t *arg,
2070 					  bool is_remount)
2071 {
2072 #ifdef CONFIG_FS_ENCRYPTION
2073 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2074 	int err;
2075 
2076 	/*
2077 	 * This mount option is just for testing, and it's not worthwhile to
2078 	 * implement the extra complexity (e.g. RCU protection) that would be
2079 	 * needed to allow it to be set or changed during remount.  We do allow
2080 	 * it to be specified during remount, but only if there is no change.
2081 	 */
2082 	if (is_remount && !sbi->s_dummy_enc_policy.policy) {
2083 		ext4_msg(sb, KERN_WARNING,
2084 			 "Can't set test_dummy_encryption on remount");
2085 		return -1;
2086 	}
2087 	err = fscrypt_set_test_dummy_encryption(sb, arg->from,
2088 						&sbi->s_dummy_enc_policy);
2089 	if (err) {
2090 		if (err == -EEXIST)
2091 			ext4_msg(sb, KERN_WARNING,
2092 				 "Can't change test_dummy_encryption on remount");
2093 		else if (err == -EINVAL)
2094 			ext4_msg(sb, KERN_WARNING,
2095 				 "Value of option \"%s\" is unrecognized", opt);
2096 		else
2097 			ext4_msg(sb, KERN_WARNING,
2098 				 "Error processing option \"%s\" [%d]",
2099 				 opt, err);
2100 		return -1;
2101 	}
2102 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2103 #else
2104 	ext4_msg(sb, KERN_WARNING,
2105 		 "Test dummy encryption mount option ignored");
2106 #endif
2107 	return 1;
2108 }
2109 
2110 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
2111 			    substring_t *args, unsigned long *journal_devnum,
2112 			    unsigned int *journal_ioprio, int is_remount)
2113 {
2114 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2115 	const struct mount_opts *m;
2116 	kuid_t uid;
2117 	kgid_t gid;
2118 	int arg = 0;
2119 
2120 #ifdef CONFIG_QUOTA
2121 	if (token == Opt_usrjquota)
2122 		return set_qf_name(sb, USRQUOTA, &args[0]);
2123 	else if (token == Opt_grpjquota)
2124 		return set_qf_name(sb, GRPQUOTA, &args[0]);
2125 	else if (token == Opt_offusrjquota)
2126 		return clear_qf_name(sb, USRQUOTA);
2127 	else if (token == Opt_offgrpjquota)
2128 		return clear_qf_name(sb, GRPQUOTA);
2129 #endif
2130 	switch (token) {
2131 	case Opt_noacl:
2132 	case Opt_nouser_xattr:
2133 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
2134 		break;
2135 	case Opt_sb:
2136 		return 1;	/* handled by get_sb_block() */
2137 	case Opt_removed:
2138 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
2139 		return 1;
2140 	case Opt_abort:
2141 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
2142 		return 1;
2143 	case Opt_i_version:
2144 		sb->s_flags |= SB_I_VERSION;
2145 		return 1;
2146 	case Opt_lazytime:
2147 		sb->s_flags |= SB_LAZYTIME;
2148 		return 1;
2149 	case Opt_nolazytime:
2150 		sb->s_flags &= ~SB_LAZYTIME;
2151 		return 1;
2152 	case Opt_inlinecrypt:
2153 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2154 		sb->s_flags |= SB_INLINECRYPT;
2155 #else
2156 		ext4_msg(sb, KERN_ERR, "inline encryption not supported");
2157 #endif
2158 		return 1;
2159 	}
2160 
2161 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
2162 		if (token == m->token)
2163 			break;
2164 
2165 	if (m->token == Opt_err) {
2166 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
2167 			 "or missing value", opt);
2168 		return -1;
2169 	}
2170 
2171 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2172 		ext4_msg(sb, KERN_ERR,
2173 			 "Mount option \"%s\" incompatible with ext2", opt);
2174 		return -1;
2175 	}
2176 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2177 		ext4_msg(sb, KERN_ERR,
2178 			 "Mount option \"%s\" incompatible with ext3", opt);
2179 		return -1;
2180 	}
2181 
2182 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
2183 		return -1;
2184 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
2185 		return -1;
2186 	if (m->flags & MOPT_EXPLICIT) {
2187 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2188 			set_opt2(sb, EXPLICIT_DELALLOC);
2189 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2190 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
2191 		} else
2192 			return -1;
2193 	}
2194 	if (m->flags & MOPT_CLEAR_ERR)
2195 		clear_opt(sb, ERRORS_MASK);
2196 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
2197 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
2198 			 "options when quota turned on");
2199 		return -1;
2200 	}
2201 
2202 	if (m->flags & MOPT_NOSUPPORT) {
2203 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
2204 	} else if (token == Opt_commit) {
2205 		if (arg == 0)
2206 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
2207 		else if (arg > INT_MAX / HZ) {
2208 			ext4_msg(sb, KERN_ERR,
2209 				 "Invalid commit interval %d, "
2210 				 "must be smaller than %d",
2211 				 arg, INT_MAX / HZ);
2212 			return -1;
2213 		}
2214 		sbi->s_commit_interval = HZ * arg;
2215 	} else if (token == Opt_debug_want_extra_isize) {
2216 		if ((arg & 1) ||
2217 		    (arg < 4) ||
2218 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2219 			ext4_msg(sb, KERN_ERR,
2220 				 "Invalid want_extra_isize %d", arg);
2221 			return -1;
2222 		}
2223 		sbi->s_want_extra_isize = arg;
2224 	} else if (token == Opt_max_batch_time) {
2225 		sbi->s_max_batch_time = arg;
2226 	} else if (token == Opt_min_batch_time) {
2227 		sbi->s_min_batch_time = arg;
2228 	} else if (token == Opt_inode_readahead_blks) {
2229 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2230 			ext4_msg(sb, KERN_ERR,
2231 				 "EXT4-fs: inode_readahead_blks must be "
2232 				 "0 or a power of 2 smaller than 2^31");
2233 			return -1;
2234 		}
2235 		sbi->s_inode_readahead_blks = arg;
2236 	} else if (token == Opt_init_itable) {
2237 		set_opt(sb, INIT_INODE_TABLE);
2238 		if (!args->from)
2239 			arg = EXT4_DEF_LI_WAIT_MULT;
2240 		sbi->s_li_wait_mult = arg;
2241 	} else if (token == Opt_max_dir_size_kb) {
2242 		sbi->s_max_dir_size_kb = arg;
2243 #ifdef CONFIG_EXT4_DEBUG
2244 	} else if (token == Opt_fc_debug_max_replay) {
2245 		sbi->s_fc_debug_max_replay = arg;
2246 #endif
2247 	} else if (token == Opt_stripe) {
2248 		sbi->s_stripe = arg;
2249 	} else if (token == Opt_resuid) {
2250 		uid = make_kuid(current_user_ns(), arg);
2251 		if (!uid_valid(uid)) {
2252 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2253 			return -1;
2254 		}
2255 		sbi->s_resuid = uid;
2256 	} else if (token == Opt_resgid) {
2257 		gid = make_kgid(current_user_ns(), arg);
2258 		if (!gid_valid(gid)) {
2259 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2260 			return -1;
2261 		}
2262 		sbi->s_resgid = gid;
2263 	} else if (token == Opt_journal_dev) {
2264 		if (is_remount) {
2265 			ext4_msg(sb, KERN_ERR,
2266 				 "Cannot specify journal on remount");
2267 			return -1;
2268 		}
2269 		*journal_devnum = arg;
2270 	} else if (token == Opt_journal_path) {
2271 		char *journal_path;
2272 		struct inode *journal_inode;
2273 		struct path path;
2274 		int error;
2275 
2276 		if (is_remount) {
2277 			ext4_msg(sb, KERN_ERR,
2278 				 "Cannot specify journal on remount");
2279 			return -1;
2280 		}
2281 		journal_path = match_strdup(&args[0]);
2282 		if (!journal_path) {
2283 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2284 				"journal device string");
2285 			return -1;
2286 		}
2287 
2288 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2289 		if (error) {
2290 			ext4_msg(sb, KERN_ERR, "error: could not find "
2291 				"journal device path: error %d", error);
2292 			kfree(journal_path);
2293 			return -1;
2294 		}
2295 
2296 		journal_inode = d_inode(path.dentry);
2297 		if (!S_ISBLK(journal_inode->i_mode)) {
2298 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2299 				"is not a block device", journal_path);
2300 			path_put(&path);
2301 			kfree(journal_path);
2302 			return -1;
2303 		}
2304 
2305 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2306 		path_put(&path);
2307 		kfree(journal_path);
2308 	} else if (token == Opt_journal_ioprio) {
2309 		if (arg > 7) {
2310 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2311 				 " (must be 0-7)");
2312 			return -1;
2313 		}
2314 		*journal_ioprio =
2315 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2316 	} else if (token == Opt_test_dummy_encryption) {
2317 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2318 						      is_remount);
2319 	} else if (m->flags & MOPT_DATAJ) {
2320 		if (is_remount) {
2321 			if (!sbi->s_journal)
2322 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2323 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2324 				ext4_msg(sb, KERN_ERR,
2325 					 "Cannot change data mode on remount");
2326 				return -1;
2327 			}
2328 		} else {
2329 			clear_opt(sb, DATA_FLAGS);
2330 			sbi->s_mount_opt |= m->mount_opt;
2331 		}
2332 #ifdef CONFIG_QUOTA
2333 	} else if (m->flags & MOPT_QFMT) {
2334 		if (sb_any_quota_loaded(sb) &&
2335 		    sbi->s_jquota_fmt != m->mount_opt) {
2336 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2337 				 "quota options when quota turned on");
2338 			return -1;
2339 		}
2340 		if (ext4_has_feature_quota(sb)) {
2341 			ext4_msg(sb, KERN_INFO,
2342 				 "Quota format mount options ignored "
2343 				 "when QUOTA feature is enabled");
2344 			return 1;
2345 		}
2346 		sbi->s_jquota_fmt = m->mount_opt;
2347 #endif
2348 	} else if (token == Opt_dax || token == Opt_dax_always ||
2349 		   token == Opt_dax_inode || token == Opt_dax_never) {
2350 #ifdef CONFIG_FS_DAX
2351 		switch (token) {
2352 		case Opt_dax:
2353 		case Opt_dax_always:
2354 			if (is_remount &&
2355 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2356 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2357 			fail_dax_change_remount:
2358 				ext4_msg(sb, KERN_ERR, "can't change "
2359 					 "dax mount option while remounting");
2360 				return -1;
2361 			}
2362 			if (is_remount &&
2363 			    (test_opt(sb, DATA_FLAGS) ==
2364 			     EXT4_MOUNT_JOURNAL_DATA)) {
2365 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2366 					     "both data=journal and dax");
2367 				    return -1;
2368 			}
2369 			ext4_msg(sb, KERN_WARNING,
2370 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2371 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2372 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2373 			break;
2374 		case Opt_dax_never:
2375 			if (is_remount &&
2376 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2377 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2378 				goto fail_dax_change_remount;
2379 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2380 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2381 			break;
2382 		case Opt_dax_inode:
2383 			if (is_remount &&
2384 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2385 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2386 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2387 				goto fail_dax_change_remount;
2388 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2389 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2390 			/* Strictly for printing options */
2391 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2392 			break;
2393 		}
2394 #else
2395 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2396 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2397 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2398 		return -1;
2399 #endif
2400 	} else if (token == Opt_data_err_abort) {
2401 		sbi->s_mount_opt |= m->mount_opt;
2402 	} else if (token == Opt_data_err_ignore) {
2403 		sbi->s_mount_opt &= ~m->mount_opt;
2404 	} else {
2405 		if (!args->from)
2406 			arg = 1;
2407 		if (m->flags & MOPT_CLEAR)
2408 			arg = !arg;
2409 		else if (unlikely(!(m->flags & MOPT_SET))) {
2410 			ext4_msg(sb, KERN_WARNING,
2411 				 "buggy handling of option %s", opt);
2412 			WARN_ON(1);
2413 			return -1;
2414 		}
2415 		if (m->flags & MOPT_2) {
2416 			if (arg != 0)
2417 				sbi->s_mount_opt2 |= m->mount_opt;
2418 			else
2419 				sbi->s_mount_opt2 &= ~m->mount_opt;
2420 		} else {
2421 			if (arg != 0)
2422 				sbi->s_mount_opt |= m->mount_opt;
2423 			else
2424 				sbi->s_mount_opt &= ~m->mount_opt;
2425 		}
2426 	}
2427 	return 1;
2428 }
2429 
2430 static int parse_options(char *options, struct super_block *sb,
2431 			 unsigned long *journal_devnum,
2432 			 unsigned int *journal_ioprio,
2433 			 int is_remount)
2434 {
2435 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2436 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2437 	substring_t args[MAX_OPT_ARGS];
2438 	int token;
2439 
2440 	if (!options)
2441 		return 1;
2442 
2443 	while ((p = strsep(&options, ",")) != NULL) {
2444 		if (!*p)
2445 			continue;
2446 		/*
2447 		 * Initialize args struct so we know whether arg was
2448 		 * found; some options take optional arguments.
2449 		 */
2450 		args[0].to = args[0].from = NULL;
2451 		token = match_token(p, tokens, args);
2452 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2453 				     journal_ioprio, is_remount) < 0)
2454 			return 0;
2455 	}
2456 #ifdef CONFIG_QUOTA
2457 	/*
2458 	 * We do the test below only for project quotas. 'usrquota' and
2459 	 * 'grpquota' mount options are allowed even without quota feature
2460 	 * to support legacy quotas in quota files.
2461 	 */
2462 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2463 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2464 			 "Cannot enable project quota enforcement.");
2465 		return 0;
2466 	}
2467 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2468 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2469 	if (usr_qf_name || grp_qf_name) {
2470 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2471 			clear_opt(sb, USRQUOTA);
2472 
2473 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2474 			clear_opt(sb, GRPQUOTA);
2475 
2476 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2477 			ext4_msg(sb, KERN_ERR, "old and new quota "
2478 					"format mixing");
2479 			return 0;
2480 		}
2481 
2482 		if (!sbi->s_jquota_fmt) {
2483 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2484 					"not specified");
2485 			return 0;
2486 		}
2487 	}
2488 #endif
2489 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2490 		int blocksize =
2491 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2492 		if (blocksize < PAGE_SIZE)
2493 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2494 				 "experimental mount option 'dioread_nolock' "
2495 				 "for blocksize < PAGE_SIZE");
2496 	}
2497 	return 1;
2498 }
2499 
2500 static inline void ext4_show_quota_options(struct seq_file *seq,
2501 					   struct super_block *sb)
2502 {
2503 #if defined(CONFIG_QUOTA)
2504 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2505 	char *usr_qf_name, *grp_qf_name;
2506 
2507 	if (sbi->s_jquota_fmt) {
2508 		char *fmtname = "";
2509 
2510 		switch (sbi->s_jquota_fmt) {
2511 		case QFMT_VFS_OLD:
2512 			fmtname = "vfsold";
2513 			break;
2514 		case QFMT_VFS_V0:
2515 			fmtname = "vfsv0";
2516 			break;
2517 		case QFMT_VFS_V1:
2518 			fmtname = "vfsv1";
2519 			break;
2520 		}
2521 		seq_printf(seq, ",jqfmt=%s", fmtname);
2522 	}
2523 
2524 	rcu_read_lock();
2525 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2526 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2527 	if (usr_qf_name)
2528 		seq_show_option(seq, "usrjquota", usr_qf_name);
2529 	if (grp_qf_name)
2530 		seq_show_option(seq, "grpjquota", grp_qf_name);
2531 	rcu_read_unlock();
2532 #endif
2533 }
2534 
2535 static const char *token2str(int token)
2536 {
2537 	const struct match_token *t;
2538 
2539 	for (t = tokens; t->token != Opt_err; t++)
2540 		if (t->token == token && !strchr(t->pattern, '='))
2541 			break;
2542 	return t->pattern;
2543 }
2544 
2545 /*
2546  * Show an option if
2547  *  - it's set to a non-default value OR
2548  *  - if the per-sb default is different from the global default
2549  */
2550 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2551 			      int nodefs)
2552 {
2553 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2554 	struct ext4_super_block *es = sbi->s_es;
2555 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2556 	const struct mount_opts *m;
2557 	char sep = nodefs ? '\n' : ',';
2558 
2559 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2560 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2561 
2562 	if (sbi->s_sb_block != 1)
2563 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2564 
2565 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2566 		int want_set = m->flags & MOPT_SET;
2567 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2568 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2569 			continue;
2570 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2571 			continue; /* skip if same as the default */
2572 		if ((want_set &&
2573 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2574 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2575 			continue; /* select Opt_noFoo vs Opt_Foo */
2576 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2577 	}
2578 
2579 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2580 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2581 		SEQ_OPTS_PRINT("resuid=%u",
2582 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2583 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2584 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2585 		SEQ_OPTS_PRINT("resgid=%u",
2586 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2587 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2588 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2589 		SEQ_OPTS_PUTS("errors=remount-ro");
2590 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2591 		SEQ_OPTS_PUTS("errors=continue");
2592 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2593 		SEQ_OPTS_PUTS("errors=panic");
2594 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2595 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2596 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2597 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2598 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2599 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2600 	if (sb->s_flags & SB_I_VERSION)
2601 		SEQ_OPTS_PUTS("i_version");
2602 	if (nodefs || sbi->s_stripe)
2603 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2604 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2605 			(sbi->s_mount_opt ^ def_mount_opt)) {
2606 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2607 			SEQ_OPTS_PUTS("data=journal");
2608 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2609 			SEQ_OPTS_PUTS("data=ordered");
2610 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2611 			SEQ_OPTS_PUTS("data=writeback");
2612 	}
2613 	if (nodefs ||
2614 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2615 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2616 			       sbi->s_inode_readahead_blks);
2617 
2618 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2619 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2620 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2621 	if (nodefs || sbi->s_max_dir_size_kb)
2622 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2623 	if (test_opt(sb, DATA_ERR_ABORT))
2624 		SEQ_OPTS_PUTS("data_err=abort");
2625 
2626 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2627 
2628 	if (sb->s_flags & SB_INLINECRYPT)
2629 		SEQ_OPTS_PUTS("inlinecrypt");
2630 
2631 	if (test_opt(sb, DAX_ALWAYS)) {
2632 		if (IS_EXT2_SB(sb))
2633 			SEQ_OPTS_PUTS("dax");
2634 		else
2635 			SEQ_OPTS_PUTS("dax=always");
2636 	} else if (test_opt2(sb, DAX_NEVER)) {
2637 		SEQ_OPTS_PUTS("dax=never");
2638 	} else if (test_opt2(sb, DAX_INODE)) {
2639 		SEQ_OPTS_PUTS("dax=inode");
2640 	}
2641 
2642 	if (test_opt2(sb, JOURNAL_FAST_COMMIT))
2643 		SEQ_OPTS_PUTS("fast_commit");
2644 
2645 	ext4_show_quota_options(seq, sb);
2646 	return 0;
2647 }
2648 
2649 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2650 {
2651 	return _ext4_show_options(seq, root->d_sb, 0);
2652 }
2653 
2654 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2655 {
2656 	struct super_block *sb = seq->private;
2657 	int rc;
2658 
2659 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2660 	rc = _ext4_show_options(seq, sb, 1);
2661 	seq_puts(seq, "\n");
2662 	return rc;
2663 }
2664 
2665 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2666 			    int read_only)
2667 {
2668 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2669 	int err = 0;
2670 
2671 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2672 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2673 			 "forcing read-only mode");
2674 		err = -EROFS;
2675 		goto done;
2676 	}
2677 	if (read_only)
2678 		goto done;
2679 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2680 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2681 			 "running e2fsck is recommended");
2682 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2683 		ext4_msg(sb, KERN_WARNING,
2684 			 "warning: mounting fs with errors, "
2685 			 "running e2fsck is recommended");
2686 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2687 		 le16_to_cpu(es->s_mnt_count) >=
2688 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2689 		ext4_msg(sb, KERN_WARNING,
2690 			 "warning: maximal mount count reached, "
2691 			 "running e2fsck is recommended");
2692 	else if (le32_to_cpu(es->s_checkinterval) &&
2693 		 (ext4_get_tstamp(es, s_lastcheck) +
2694 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2695 		ext4_msg(sb, KERN_WARNING,
2696 			 "warning: checktime reached, "
2697 			 "running e2fsck is recommended");
2698 	if (!sbi->s_journal)
2699 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2700 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2701 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2702 	le16_add_cpu(&es->s_mnt_count, 1);
2703 	ext4_update_tstamp(es, s_mtime);
2704 	if (sbi->s_journal)
2705 		ext4_set_feature_journal_needs_recovery(sb);
2706 
2707 	err = ext4_commit_super(sb, 1);
2708 done:
2709 	if (test_opt(sb, DEBUG))
2710 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2711 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2712 			sb->s_blocksize,
2713 			sbi->s_groups_count,
2714 			EXT4_BLOCKS_PER_GROUP(sb),
2715 			EXT4_INODES_PER_GROUP(sb),
2716 			sbi->s_mount_opt, sbi->s_mount_opt2);
2717 
2718 	cleancache_init_fs(sb);
2719 	return err;
2720 }
2721 
2722 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2723 {
2724 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2725 	struct flex_groups **old_groups, **new_groups;
2726 	int size, i, j;
2727 
2728 	if (!sbi->s_log_groups_per_flex)
2729 		return 0;
2730 
2731 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2732 	if (size <= sbi->s_flex_groups_allocated)
2733 		return 0;
2734 
2735 	new_groups = kvzalloc(roundup_pow_of_two(size *
2736 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2737 	if (!new_groups) {
2738 		ext4_msg(sb, KERN_ERR,
2739 			 "not enough memory for %d flex group pointers", size);
2740 		return -ENOMEM;
2741 	}
2742 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2743 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2744 					 sizeof(struct flex_groups)),
2745 					 GFP_KERNEL);
2746 		if (!new_groups[i]) {
2747 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2748 				kvfree(new_groups[j]);
2749 			kvfree(new_groups);
2750 			ext4_msg(sb, KERN_ERR,
2751 				 "not enough memory for %d flex groups", size);
2752 			return -ENOMEM;
2753 		}
2754 	}
2755 	rcu_read_lock();
2756 	old_groups = rcu_dereference(sbi->s_flex_groups);
2757 	if (old_groups)
2758 		memcpy(new_groups, old_groups,
2759 		       (sbi->s_flex_groups_allocated *
2760 			sizeof(struct flex_groups *)));
2761 	rcu_read_unlock();
2762 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2763 	sbi->s_flex_groups_allocated = size;
2764 	if (old_groups)
2765 		ext4_kvfree_array_rcu(old_groups);
2766 	return 0;
2767 }
2768 
2769 static int ext4_fill_flex_info(struct super_block *sb)
2770 {
2771 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2772 	struct ext4_group_desc *gdp = NULL;
2773 	struct flex_groups *fg;
2774 	ext4_group_t flex_group;
2775 	int i, err;
2776 
2777 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2778 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2779 		sbi->s_log_groups_per_flex = 0;
2780 		return 1;
2781 	}
2782 
2783 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2784 	if (err)
2785 		goto failed;
2786 
2787 	for (i = 0; i < sbi->s_groups_count; i++) {
2788 		gdp = ext4_get_group_desc(sb, i, NULL);
2789 
2790 		flex_group = ext4_flex_group(sbi, i);
2791 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2792 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2793 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2794 			     &fg->free_clusters);
2795 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2796 	}
2797 
2798 	return 1;
2799 failed:
2800 	return 0;
2801 }
2802 
2803 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2804 				   struct ext4_group_desc *gdp)
2805 {
2806 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2807 	__u16 crc = 0;
2808 	__le32 le_group = cpu_to_le32(block_group);
2809 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2810 
2811 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2812 		/* Use new metadata_csum algorithm */
2813 		__u32 csum32;
2814 		__u16 dummy_csum = 0;
2815 
2816 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2817 				     sizeof(le_group));
2818 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2819 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2820 				     sizeof(dummy_csum));
2821 		offset += sizeof(dummy_csum);
2822 		if (offset < sbi->s_desc_size)
2823 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2824 					     sbi->s_desc_size - offset);
2825 
2826 		crc = csum32 & 0xFFFF;
2827 		goto out;
2828 	}
2829 
2830 	/* old crc16 code */
2831 	if (!ext4_has_feature_gdt_csum(sb))
2832 		return 0;
2833 
2834 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2835 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2836 	crc = crc16(crc, (__u8 *)gdp, offset);
2837 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2838 	/* for checksum of struct ext4_group_desc do the rest...*/
2839 	if (ext4_has_feature_64bit(sb) &&
2840 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2841 		crc = crc16(crc, (__u8 *)gdp + offset,
2842 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2843 				offset);
2844 
2845 out:
2846 	return cpu_to_le16(crc);
2847 }
2848 
2849 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2850 				struct ext4_group_desc *gdp)
2851 {
2852 	if (ext4_has_group_desc_csum(sb) &&
2853 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2854 		return 0;
2855 
2856 	return 1;
2857 }
2858 
2859 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2860 			      struct ext4_group_desc *gdp)
2861 {
2862 	if (!ext4_has_group_desc_csum(sb))
2863 		return;
2864 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2865 }
2866 
2867 /* Called at mount-time, super-block is locked */
2868 static int ext4_check_descriptors(struct super_block *sb,
2869 				  ext4_fsblk_t sb_block,
2870 				  ext4_group_t *first_not_zeroed)
2871 {
2872 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2873 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2874 	ext4_fsblk_t last_block;
2875 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2876 	ext4_fsblk_t block_bitmap;
2877 	ext4_fsblk_t inode_bitmap;
2878 	ext4_fsblk_t inode_table;
2879 	int flexbg_flag = 0;
2880 	ext4_group_t i, grp = sbi->s_groups_count;
2881 
2882 	if (ext4_has_feature_flex_bg(sb))
2883 		flexbg_flag = 1;
2884 
2885 	ext4_debug("Checking group descriptors");
2886 
2887 	for (i = 0; i < sbi->s_groups_count; i++) {
2888 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2889 
2890 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2891 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2892 		else
2893 			last_block = first_block +
2894 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2895 
2896 		if ((grp == sbi->s_groups_count) &&
2897 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2898 			grp = i;
2899 
2900 		block_bitmap = ext4_block_bitmap(sb, gdp);
2901 		if (block_bitmap == sb_block) {
2902 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2903 				 "Block bitmap for group %u overlaps "
2904 				 "superblock", i);
2905 			if (!sb_rdonly(sb))
2906 				return 0;
2907 		}
2908 		if (block_bitmap >= sb_block + 1 &&
2909 		    block_bitmap <= last_bg_block) {
2910 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2911 				 "Block bitmap for group %u overlaps "
2912 				 "block group descriptors", i);
2913 			if (!sb_rdonly(sb))
2914 				return 0;
2915 		}
2916 		if (block_bitmap < first_block || block_bitmap > last_block) {
2917 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2918 			       "Block bitmap for group %u not in group "
2919 			       "(block %llu)!", i, block_bitmap);
2920 			return 0;
2921 		}
2922 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2923 		if (inode_bitmap == sb_block) {
2924 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2925 				 "Inode bitmap for group %u overlaps "
2926 				 "superblock", i);
2927 			if (!sb_rdonly(sb))
2928 				return 0;
2929 		}
2930 		if (inode_bitmap >= sb_block + 1 &&
2931 		    inode_bitmap <= last_bg_block) {
2932 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2933 				 "Inode bitmap for group %u overlaps "
2934 				 "block group descriptors", i);
2935 			if (!sb_rdonly(sb))
2936 				return 0;
2937 		}
2938 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2939 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2940 			       "Inode bitmap for group %u not in group "
2941 			       "(block %llu)!", i, inode_bitmap);
2942 			return 0;
2943 		}
2944 		inode_table = ext4_inode_table(sb, gdp);
2945 		if (inode_table == sb_block) {
2946 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2947 				 "Inode table for group %u overlaps "
2948 				 "superblock", i);
2949 			if (!sb_rdonly(sb))
2950 				return 0;
2951 		}
2952 		if (inode_table >= sb_block + 1 &&
2953 		    inode_table <= last_bg_block) {
2954 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2955 				 "Inode table for group %u overlaps "
2956 				 "block group descriptors", i);
2957 			if (!sb_rdonly(sb))
2958 				return 0;
2959 		}
2960 		if (inode_table < first_block ||
2961 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2962 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2963 			       "Inode table for group %u not in group "
2964 			       "(block %llu)!", i, inode_table);
2965 			return 0;
2966 		}
2967 		ext4_lock_group(sb, i);
2968 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2969 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2970 				 "Checksum for group %u failed (%u!=%u)",
2971 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2972 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2973 			if (!sb_rdonly(sb)) {
2974 				ext4_unlock_group(sb, i);
2975 				return 0;
2976 			}
2977 		}
2978 		ext4_unlock_group(sb, i);
2979 		if (!flexbg_flag)
2980 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2981 	}
2982 	if (NULL != first_not_zeroed)
2983 		*first_not_zeroed = grp;
2984 	return 1;
2985 }
2986 
2987 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2988  * the superblock) which were deleted from all directories, but held open by
2989  * a process at the time of a crash.  We walk the list and try to delete these
2990  * inodes at recovery time (only with a read-write filesystem).
2991  *
2992  * In order to keep the orphan inode chain consistent during traversal (in
2993  * case of crash during recovery), we link each inode into the superblock
2994  * orphan list_head and handle it the same way as an inode deletion during
2995  * normal operation (which journals the operations for us).
2996  *
2997  * We only do an iget() and an iput() on each inode, which is very safe if we
2998  * accidentally point at an in-use or already deleted inode.  The worst that
2999  * can happen in this case is that we get a "bit already cleared" message from
3000  * ext4_free_inode().  The only reason we would point at a wrong inode is if
3001  * e2fsck was run on this filesystem, and it must have already done the orphan
3002  * inode cleanup for us, so we can safely abort without any further action.
3003  */
3004 static void ext4_orphan_cleanup(struct super_block *sb,
3005 				struct ext4_super_block *es)
3006 {
3007 	unsigned int s_flags = sb->s_flags;
3008 	int ret, nr_orphans = 0, nr_truncates = 0;
3009 #ifdef CONFIG_QUOTA
3010 	int quota_update = 0;
3011 	int i;
3012 #endif
3013 	if (!es->s_last_orphan) {
3014 		jbd_debug(4, "no orphan inodes to clean up\n");
3015 		return;
3016 	}
3017 
3018 	if (bdev_read_only(sb->s_bdev)) {
3019 		ext4_msg(sb, KERN_ERR, "write access "
3020 			"unavailable, skipping orphan cleanup");
3021 		return;
3022 	}
3023 
3024 	/* Check if feature set would not allow a r/w mount */
3025 	if (!ext4_feature_set_ok(sb, 0)) {
3026 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
3027 			 "unknown ROCOMPAT features");
3028 		return;
3029 	}
3030 
3031 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3032 		/* don't clear list on RO mount w/ errors */
3033 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
3034 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
3035 				  "clearing orphan list.\n");
3036 			es->s_last_orphan = 0;
3037 		}
3038 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3039 		return;
3040 	}
3041 
3042 	if (s_flags & SB_RDONLY) {
3043 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
3044 		sb->s_flags &= ~SB_RDONLY;
3045 	}
3046 #ifdef CONFIG_QUOTA
3047 	/* Needed for iput() to work correctly and not trash data */
3048 	sb->s_flags |= SB_ACTIVE;
3049 
3050 	/*
3051 	 * Turn on quotas which were not enabled for read-only mounts if
3052 	 * filesystem has quota feature, so that they are updated correctly.
3053 	 */
3054 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
3055 		int ret = ext4_enable_quotas(sb);
3056 
3057 		if (!ret)
3058 			quota_update = 1;
3059 		else
3060 			ext4_msg(sb, KERN_ERR,
3061 				"Cannot turn on quotas: error %d", ret);
3062 	}
3063 
3064 	/* Turn on journaled quotas used for old sytle */
3065 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3066 		if (EXT4_SB(sb)->s_qf_names[i]) {
3067 			int ret = ext4_quota_on_mount(sb, i);
3068 
3069 			if (!ret)
3070 				quota_update = 1;
3071 			else
3072 				ext4_msg(sb, KERN_ERR,
3073 					"Cannot turn on journaled "
3074 					"quota: type %d: error %d", i, ret);
3075 		}
3076 	}
3077 #endif
3078 
3079 	while (es->s_last_orphan) {
3080 		struct inode *inode;
3081 
3082 		/*
3083 		 * We may have encountered an error during cleanup; if
3084 		 * so, skip the rest.
3085 		 */
3086 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3087 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3088 			es->s_last_orphan = 0;
3089 			break;
3090 		}
3091 
3092 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
3093 		if (IS_ERR(inode)) {
3094 			es->s_last_orphan = 0;
3095 			break;
3096 		}
3097 
3098 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
3099 		dquot_initialize(inode);
3100 		if (inode->i_nlink) {
3101 			if (test_opt(sb, DEBUG))
3102 				ext4_msg(sb, KERN_DEBUG,
3103 					"%s: truncating inode %lu to %lld bytes",
3104 					__func__, inode->i_ino, inode->i_size);
3105 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
3106 				  inode->i_ino, inode->i_size);
3107 			inode_lock(inode);
3108 			truncate_inode_pages(inode->i_mapping, inode->i_size);
3109 			ret = ext4_truncate(inode);
3110 			if (ret)
3111 				ext4_std_error(inode->i_sb, ret);
3112 			inode_unlock(inode);
3113 			nr_truncates++;
3114 		} else {
3115 			if (test_opt(sb, DEBUG))
3116 				ext4_msg(sb, KERN_DEBUG,
3117 					"%s: deleting unreferenced inode %lu",
3118 					__func__, inode->i_ino);
3119 			jbd_debug(2, "deleting unreferenced inode %lu\n",
3120 				  inode->i_ino);
3121 			nr_orphans++;
3122 		}
3123 		iput(inode);  /* The delete magic happens here! */
3124 	}
3125 
3126 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
3127 
3128 	if (nr_orphans)
3129 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
3130 		       PLURAL(nr_orphans));
3131 	if (nr_truncates)
3132 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
3133 		       PLURAL(nr_truncates));
3134 #ifdef CONFIG_QUOTA
3135 	/* Turn off quotas if they were enabled for orphan cleanup */
3136 	if (quota_update) {
3137 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3138 			if (sb_dqopt(sb)->files[i])
3139 				dquot_quota_off(sb, i);
3140 		}
3141 	}
3142 #endif
3143 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
3144 }
3145 
3146 /*
3147  * Maximal extent format file size.
3148  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3149  * extent format containers, within a sector_t, and within i_blocks
3150  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3151  * so that won't be a limiting factor.
3152  *
3153  * However there is other limiting factor. We do store extents in the form
3154  * of starting block and length, hence the resulting length of the extent
3155  * covering maximum file size must fit into on-disk format containers as
3156  * well. Given that length is always by 1 unit bigger than max unit (because
3157  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3158  *
3159  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3160  */
3161 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3162 {
3163 	loff_t res;
3164 	loff_t upper_limit = MAX_LFS_FILESIZE;
3165 
3166 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3167 
3168 	if (!has_huge_files) {
3169 		upper_limit = (1LL << 32) - 1;
3170 
3171 		/* total blocks in file system block size */
3172 		upper_limit >>= (blkbits - 9);
3173 		upper_limit <<= blkbits;
3174 	}
3175 
3176 	/*
3177 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3178 	 * by one fs block, so ee_len can cover the extent of maximum file
3179 	 * size
3180 	 */
3181 	res = (1LL << 32) - 1;
3182 	res <<= blkbits;
3183 
3184 	/* Sanity check against vm- & vfs- imposed limits */
3185 	if (res > upper_limit)
3186 		res = upper_limit;
3187 
3188 	return res;
3189 }
3190 
3191 /*
3192  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3193  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3194  * We need to be 1 filesystem block less than the 2^48 sector limit.
3195  */
3196 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3197 {
3198 	loff_t res = EXT4_NDIR_BLOCKS;
3199 	int meta_blocks;
3200 	loff_t upper_limit;
3201 	/* This is calculated to be the largest file size for a dense, block
3202 	 * mapped file such that the file's total number of 512-byte sectors,
3203 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3204 	 *
3205 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3206 	 * number of 512-byte sectors of the file.
3207 	 */
3208 
3209 	if (!has_huge_files) {
3210 		/*
3211 		 * !has_huge_files or implies that the inode i_block field
3212 		 * represents total file blocks in 2^32 512-byte sectors ==
3213 		 * size of vfs inode i_blocks * 8
3214 		 */
3215 		upper_limit = (1LL << 32) - 1;
3216 
3217 		/* total blocks in file system block size */
3218 		upper_limit >>= (bits - 9);
3219 
3220 	} else {
3221 		/*
3222 		 * We use 48 bit ext4_inode i_blocks
3223 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3224 		 * represent total number of blocks in
3225 		 * file system block size
3226 		 */
3227 		upper_limit = (1LL << 48) - 1;
3228 
3229 	}
3230 
3231 	/* indirect blocks */
3232 	meta_blocks = 1;
3233 	/* double indirect blocks */
3234 	meta_blocks += 1 + (1LL << (bits-2));
3235 	/* tripple indirect blocks */
3236 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3237 
3238 	upper_limit -= meta_blocks;
3239 	upper_limit <<= bits;
3240 
3241 	res += 1LL << (bits-2);
3242 	res += 1LL << (2*(bits-2));
3243 	res += 1LL << (3*(bits-2));
3244 	res <<= bits;
3245 	if (res > upper_limit)
3246 		res = upper_limit;
3247 
3248 	if (res > MAX_LFS_FILESIZE)
3249 		res = MAX_LFS_FILESIZE;
3250 
3251 	return res;
3252 }
3253 
3254 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3255 				   ext4_fsblk_t logical_sb_block, int nr)
3256 {
3257 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3258 	ext4_group_t bg, first_meta_bg;
3259 	int has_super = 0;
3260 
3261 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3262 
3263 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3264 		return logical_sb_block + nr + 1;
3265 	bg = sbi->s_desc_per_block * nr;
3266 	if (ext4_bg_has_super(sb, bg))
3267 		has_super = 1;
3268 
3269 	/*
3270 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3271 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3272 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3273 	 * compensate.
3274 	 */
3275 	if (sb->s_blocksize == 1024 && nr == 0 &&
3276 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3277 		has_super++;
3278 
3279 	return (has_super + ext4_group_first_block_no(sb, bg));
3280 }
3281 
3282 /**
3283  * ext4_get_stripe_size: Get the stripe size.
3284  * @sbi: In memory super block info
3285  *
3286  * If we have specified it via mount option, then
3287  * use the mount option value. If the value specified at mount time is
3288  * greater than the blocks per group use the super block value.
3289  * If the super block value is greater than blocks per group return 0.
3290  * Allocator needs it be less than blocks per group.
3291  *
3292  */
3293 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3294 {
3295 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3296 	unsigned long stripe_width =
3297 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3298 	int ret;
3299 
3300 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3301 		ret = sbi->s_stripe;
3302 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3303 		ret = stripe_width;
3304 	else if (stride && stride <= sbi->s_blocks_per_group)
3305 		ret = stride;
3306 	else
3307 		ret = 0;
3308 
3309 	/*
3310 	 * If the stripe width is 1, this makes no sense and
3311 	 * we set it to 0 to turn off stripe handling code.
3312 	 */
3313 	if (ret <= 1)
3314 		ret = 0;
3315 
3316 	return ret;
3317 }
3318 
3319 /*
3320  * Check whether this filesystem can be mounted based on
3321  * the features present and the RDONLY/RDWR mount requested.
3322  * Returns 1 if this filesystem can be mounted as requested,
3323  * 0 if it cannot be.
3324  */
3325 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3326 {
3327 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3328 		ext4_msg(sb, KERN_ERR,
3329 			"Couldn't mount because of "
3330 			"unsupported optional features (%x)",
3331 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3332 			~EXT4_FEATURE_INCOMPAT_SUPP));
3333 		return 0;
3334 	}
3335 
3336 #ifndef CONFIG_UNICODE
3337 	if (ext4_has_feature_casefold(sb)) {
3338 		ext4_msg(sb, KERN_ERR,
3339 			 "Filesystem with casefold feature cannot be "
3340 			 "mounted without CONFIG_UNICODE");
3341 		return 0;
3342 	}
3343 #endif
3344 
3345 	if (readonly)
3346 		return 1;
3347 
3348 	if (ext4_has_feature_readonly(sb)) {
3349 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3350 		sb->s_flags |= SB_RDONLY;
3351 		return 1;
3352 	}
3353 
3354 	/* Check that feature set is OK for a read-write mount */
3355 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3356 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3357 			 "unsupported optional features (%x)",
3358 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3359 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3360 		return 0;
3361 	}
3362 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3363 		ext4_msg(sb, KERN_ERR,
3364 			 "Can't support bigalloc feature without "
3365 			 "extents feature\n");
3366 		return 0;
3367 	}
3368 
3369 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3370 	if (!readonly && (ext4_has_feature_quota(sb) ||
3371 			  ext4_has_feature_project(sb))) {
3372 		ext4_msg(sb, KERN_ERR,
3373 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3374 		return 0;
3375 	}
3376 #endif  /* CONFIG_QUOTA */
3377 	return 1;
3378 }
3379 
3380 /*
3381  * This function is called once a day if we have errors logged
3382  * on the file system
3383  */
3384 static void print_daily_error_info(struct timer_list *t)
3385 {
3386 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3387 	struct super_block *sb = sbi->s_sb;
3388 	struct ext4_super_block *es = sbi->s_es;
3389 
3390 	if (es->s_error_count)
3391 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3392 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3393 			 le32_to_cpu(es->s_error_count));
3394 	if (es->s_first_error_time) {
3395 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3396 		       sb->s_id,
3397 		       ext4_get_tstamp(es, s_first_error_time),
3398 		       (int) sizeof(es->s_first_error_func),
3399 		       es->s_first_error_func,
3400 		       le32_to_cpu(es->s_first_error_line));
3401 		if (es->s_first_error_ino)
3402 			printk(KERN_CONT ": inode %u",
3403 			       le32_to_cpu(es->s_first_error_ino));
3404 		if (es->s_first_error_block)
3405 			printk(KERN_CONT ": block %llu", (unsigned long long)
3406 			       le64_to_cpu(es->s_first_error_block));
3407 		printk(KERN_CONT "\n");
3408 	}
3409 	if (es->s_last_error_time) {
3410 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3411 		       sb->s_id,
3412 		       ext4_get_tstamp(es, s_last_error_time),
3413 		       (int) sizeof(es->s_last_error_func),
3414 		       es->s_last_error_func,
3415 		       le32_to_cpu(es->s_last_error_line));
3416 		if (es->s_last_error_ino)
3417 			printk(KERN_CONT ": inode %u",
3418 			       le32_to_cpu(es->s_last_error_ino));
3419 		if (es->s_last_error_block)
3420 			printk(KERN_CONT ": block %llu", (unsigned long long)
3421 			       le64_to_cpu(es->s_last_error_block));
3422 		printk(KERN_CONT "\n");
3423 	}
3424 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3425 }
3426 
3427 /* Find next suitable group and run ext4_init_inode_table */
3428 static int ext4_run_li_request(struct ext4_li_request *elr)
3429 {
3430 	struct ext4_group_desc *gdp = NULL;
3431 	struct super_block *sb = elr->lr_super;
3432 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3433 	ext4_group_t group = elr->lr_next_group;
3434 	unsigned long timeout = 0;
3435 	unsigned int prefetch_ios = 0;
3436 	int ret = 0;
3437 
3438 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3439 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3440 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3441 		if (prefetch_ios)
3442 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3443 					      prefetch_ios);
3444 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3445 					    prefetch_ios);
3446 		if (group >= elr->lr_next_group) {
3447 			ret = 1;
3448 			if (elr->lr_first_not_zeroed != ngroups &&
3449 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3450 				elr->lr_next_group = elr->lr_first_not_zeroed;
3451 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3452 				ret = 0;
3453 			}
3454 		}
3455 		return ret;
3456 	}
3457 
3458 	for (; group < ngroups; group++) {
3459 		gdp = ext4_get_group_desc(sb, group, NULL);
3460 		if (!gdp) {
3461 			ret = 1;
3462 			break;
3463 		}
3464 
3465 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3466 			break;
3467 	}
3468 
3469 	if (group >= ngroups)
3470 		ret = 1;
3471 
3472 	if (!ret) {
3473 		timeout = jiffies;
3474 		ret = ext4_init_inode_table(sb, group,
3475 					    elr->lr_timeout ? 0 : 1);
3476 		trace_ext4_lazy_itable_init(sb, group);
3477 		if (elr->lr_timeout == 0) {
3478 			timeout = (jiffies - timeout) *
3479 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3480 			elr->lr_timeout = timeout;
3481 		}
3482 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3483 		elr->lr_next_group = group + 1;
3484 	}
3485 	return ret;
3486 }
3487 
3488 /*
3489  * Remove lr_request from the list_request and free the
3490  * request structure. Should be called with li_list_mtx held
3491  */
3492 static void ext4_remove_li_request(struct ext4_li_request *elr)
3493 {
3494 	if (!elr)
3495 		return;
3496 
3497 	list_del(&elr->lr_request);
3498 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3499 	kfree(elr);
3500 }
3501 
3502 static void ext4_unregister_li_request(struct super_block *sb)
3503 {
3504 	mutex_lock(&ext4_li_mtx);
3505 	if (!ext4_li_info) {
3506 		mutex_unlock(&ext4_li_mtx);
3507 		return;
3508 	}
3509 
3510 	mutex_lock(&ext4_li_info->li_list_mtx);
3511 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3512 	mutex_unlock(&ext4_li_info->li_list_mtx);
3513 	mutex_unlock(&ext4_li_mtx);
3514 }
3515 
3516 static struct task_struct *ext4_lazyinit_task;
3517 
3518 /*
3519  * This is the function where ext4lazyinit thread lives. It walks
3520  * through the request list searching for next scheduled filesystem.
3521  * When such a fs is found, run the lazy initialization request
3522  * (ext4_rn_li_request) and keep track of the time spend in this
3523  * function. Based on that time we compute next schedule time of
3524  * the request. When walking through the list is complete, compute
3525  * next waking time and put itself into sleep.
3526  */
3527 static int ext4_lazyinit_thread(void *arg)
3528 {
3529 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3530 	struct list_head *pos, *n;
3531 	struct ext4_li_request *elr;
3532 	unsigned long next_wakeup, cur;
3533 
3534 	BUG_ON(NULL == eli);
3535 
3536 cont_thread:
3537 	while (true) {
3538 		next_wakeup = MAX_JIFFY_OFFSET;
3539 
3540 		mutex_lock(&eli->li_list_mtx);
3541 		if (list_empty(&eli->li_request_list)) {
3542 			mutex_unlock(&eli->li_list_mtx);
3543 			goto exit_thread;
3544 		}
3545 		list_for_each_safe(pos, n, &eli->li_request_list) {
3546 			int err = 0;
3547 			int progress = 0;
3548 			elr = list_entry(pos, struct ext4_li_request,
3549 					 lr_request);
3550 
3551 			if (time_before(jiffies, elr->lr_next_sched)) {
3552 				if (time_before(elr->lr_next_sched, next_wakeup))
3553 					next_wakeup = elr->lr_next_sched;
3554 				continue;
3555 			}
3556 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3557 				if (sb_start_write_trylock(elr->lr_super)) {
3558 					progress = 1;
3559 					/*
3560 					 * We hold sb->s_umount, sb can not
3561 					 * be removed from the list, it is
3562 					 * now safe to drop li_list_mtx
3563 					 */
3564 					mutex_unlock(&eli->li_list_mtx);
3565 					err = ext4_run_li_request(elr);
3566 					sb_end_write(elr->lr_super);
3567 					mutex_lock(&eli->li_list_mtx);
3568 					n = pos->next;
3569 				}
3570 				up_read((&elr->lr_super->s_umount));
3571 			}
3572 			/* error, remove the lazy_init job */
3573 			if (err) {
3574 				ext4_remove_li_request(elr);
3575 				continue;
3576 			}
3577 			if (!progress) {
3578 				elr->lr_next_sched = jiffies +
3579 					(prandom_u32()
3580 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3581 			}
3582 			if (time_before(elr->lr_next_sched, next_wakeup))
3583 				next_wakeup = elr->lr_next_sched;
3584 		}
3585 		mutex_unlock(&eli->li_list_mtx);
3586 
3587 		try_to_freeze();
3588 
3589 		cur = jiffies;
3590 		if ((time_after_eq(cur, next_wakeup)) ||
3591 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3592 			cond_resched();
3593 			continue;
3594 		}
3595 
3596 		schedule_timeout_interruptible(next_wakeup - cur);
3597 
3598 		if (kthread_should_stop()) {
3599 			ext4_clear_request_list();
3600 			goto exit_thread;
3601 		}
3602 	}
3603 
3604 exit_thread:
3605 	/*
3606 	 * It looks like the request list is empty, but we need
3607 	 * to check it under the li_list_mtx lock, to prevent any
3608 	 * additions into it, and of course we should lock ext4_li_mtx
3609 	 * to atomically free the list and ext4_li_info, because at
3610 	 * this point another ext4 filesystem could be registering
3611 	 * new one.
3612 	 */
3613 	mutex_lock(&ext4_li_mtx);
3614 	mutex_lock(&eli->li_list_mtx);
3615 	if (!list_empty(&eli->li_request_list)) {
3616 		mutex_unlock(&eli->li_list_mtx);
3617 		mutex_unlock(&ext4_li_mtx);
3618 		goto cont_thread;
3619 	}
3620 	mutex_unlock(&eli->li_list_mtx);
3621 	kfree(ext4_li_info);
3622 	ext4_li_info = NULL;
3623 	mutex_unlock(&ext4_li_mtx);
3624 
3625 	return 0;
3626 }
3627 
3628 static void ext4_clear_request_list(void)
3629 {
3630 	struct list_head *pos, *n;
3631 	struct ext4_li_request *elr;
3632 
3633 	mutex_lock(&ext4_li_info->li_list_mtx);
3634 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3635 		elr = list_entry(pos, struct ext4_li_request,
3636 				 lr_request);
3637 		ext4_remove_li_request(elr);
3638 	}
3639 	mutex_unlock(&ext4_li_info->li_list_mtx);
3640 }
3641 
3642 static int ext4_run_lazyinit_thread(void)
3643 {
3644 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3645 					 ext4_li_info, "ext4lazyinit");
3646 	if (IS_ERR(ext4_lazyinit_task)) {
3647 		int err = PTR_ERR(ext4_lazyinit_task);
3648 		ext4_clear_request_list();
3649 		kfree(ext4_li_info);
3650 		ext4_li_info = NULL;
3651 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3652 				 "initialization thread\n",
3653 				 err);
3654 		return err;
3655 	}
3656 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3657 	return 0;
3658 }
3659 
3660 /*
3661  * Check whether it make sense to run itable init. thread or not.
3662  * If there is at least one uninitialized inode table, return
3663  * corresponding group number, else the loop goes through all
3664  * groups and return total number of groups.
3665  */
3666 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3667 {
3668 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3669 	struct ext4_group_desc *gdp = NULL;
3670 
3671 	if (!ext4_has_group_desc_csum(sb))
3672 		return ngroups;
3673 
3674 	for (group = 0; group < ngroups; group++) {
3675 		gdp = ext4_get_group_desc(sb, group, NULL);
3676 		if (!gdp)
3677 			continue;
3678 
3679 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3680 			break;
3681 	}
3682 
3683 	return group;
3684 }
3685 
3686 static int ext4_li_info_new(void)
3687 {
3688 	struct ext4_lazy_init *eli = NULL;
3689 
3690 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3691 	if (!eli)
3692 		return -ENOMEM;
3693 
3694 	INIT_LIST_HEAD(&eli->li_request_list);
3695 	mutex_init(&eli->li_list_mtx);
3696 
3697 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3698 
3699 	ext4_li_info = eli;
3700 
3701 	return 0;
3702 }
3703 
3704 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3705 					    ext4_group_t start)
3706 {
3707 	struct ext4_li_request *elr;
3708 
3709 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3710 	if (!elr)
3711 		return NULL;
3712 
3713 	elr->lr_super = sb;
3714 	elr->lr_first_not_zeroed = start;
3715 	if (test_opt(sb, PREFETCH_BLOCK_BITMAPS))
3716 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3717 	else {
3718 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3719 		elr->lr_next_group = start;
3720 	}
3721 
3722 	/*
3723 	 * Randomize first schedule time of the request to
3724 	 * spread the inode table initialization requests
3725 	 * better.
3726 	 */
3727 	elr->lr_next_sched = jiffies + (prandom_u32() %
3728 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3729 	return elr;
3730 }
3731 
3732 int ext4_register_li_request(struct super_block *sb,
3733 			     ext4_group_t first_not_zeroed)
3734 {
3735 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3736 	struct ext4_li_request *elr = NULL;
3737 	ext4_group_t ngroups = sbi->s_groups_count;
3738 	int ret = 0;
3739 
3740 	mutex_lock(&ext4_li_mtx);
3741 	if (sbi->s_li_request != NULL) {
3742 		/*
3743 		 * Reset timeout so it can be computed again, because
3744 		 * s_li_wait_mult might have changed.
3745 		 */
3746 		sbi->s_li_request->lr_timeout = 0;
3747 		goto out;
3748 	}
3749 
3750 	if (!test_opt(sb, PREFETCH_BLOCK_BITMAPS) &&
3751 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3752 	     !test_opt(sb, INIT_INODE_TABLE)))
3753 		goto out;
3754 
3755 	elr = ext4_li_request_new(sb, first_not_zeroed);
3756 	if (!elr) {
3757 		ret = -ENOMEM;
3758 		goto out;
3759 	}
3760 
3761 	if (NULL == ext4_li_info) {
3762 		ret = ext4_li_info_new();
3763 		if (ret)
3764 			goto out;
3765 	}
3766 
3767 	mutex_lock(&ext4_li_info->li_list_mtx);
3768 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3769 	mutex_unlock(&ext4_li_info->li_list_mtx);
3770 
3771 	sbi->s_li_request = elr;
3772 	/*
3773 	 * set elr to NULL here since it has been inserted to
3774 	 * the request_list and the removal and free of it is
3775 	 * handled by ext4_clear_request_list from now on.
3776 	 */
3777 	elr = NULL;
3778 
3779 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3780 		ret = ext4_run_lazyinit_thread();
3781 		if (ret)
3782 			goto out;
3783 	}
3784 out:
3785 	mutex_unlock(&ext4_li_mtx);
3786 	if (ret)
3787 		kfree(elr);
3788 	return ret;
3789 }
3790 
3791 /*
3792  * We do not need to lock anything since this is called on
3793  * module unload.
3794  */
3795 static void ext4_destroy_lazyinit_thread(void)
3796 {
3797 	/*
3798 	 * If thread exited earlier
3799 	 * there's nothing to be done.
3800 	 */
3801 	if (!ext4_li_info || !ext4_lazyinit_task)
3802 		return;
3803 
3804 	kthread_stop(ext4_lazyinit_task);
3805 }
3806 
3807 static int set_journal_csum_feature_set(struct super_block *sb)
3808 {
3809 	int ret = 1;
3810 	int compat, incompat;
3811 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3812 
3813 	if (ext4_has_metadata_csum(sb)) {
3814 		/* journal checksum v3 */
3815 		compat = 0;
3816 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3817 	} else {
3818 		/* journal checksum v1 */
3819 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3820 		incompat = 0;
3821 	}
3822 
3823 	jbd2_journal_clear_features(sbi->s_journal,
3824 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3825 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3826 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3827 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3828 		ret = jbd2_journal_set_features(sbi->s_journal,
3829 				compat, 0,
3830 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3831 				incompat);
3832 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3833 		ret = jbd2_journal_set_features(sbi->s_journal,
3834 				compat, 0,
3835 				incompat);
3836 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3837 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3838 	} else {
3839 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3840 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3841 	}
3842 
3843 	return ret;
3844 }
3845 
3846 /*
3847  * Note: calculating the overhead so we can be compatible with
3848  * historical BSD practice is quite difficult in the face of
3849  * clusters/bigalloc.  This is because multiple metadata blocks from
3850  * different block group can end up in the same allocation cluster.
3851  * Calculating the exact overhead in the face of clustered allocation
3852  * requires either O(all block bitmaps) in memory or O(number of block
3853  * groups**2) in time.  We will still calculate the superblock for
3854  * older file systems --- and if we come across with a bigalloc file
3855  * system with zero in s_overhead_clusters the estimate will be close to
3856  * correct especially for very large cluster sizes --- but for newer
3857  * file systems, it's better to calculate this figure once at mkfs
3858  * time, and store it in the superblock.  If the superblock value is
3859  * present (even for non-bigalloc file systems), we will use it.
3860  */
3861 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3862 			  char *buf)
3863 {
3864 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3865 	struct ext4_group_desc	*gdp;
3866 	ext4_fsblk_t		first_block, last_block, b;
3867 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3868 	int			s, j, count = 0;
3869 
3870 	if (!ext4_has_feature_bigalloc(sb))
3871 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3872 			sbi->s_itb_per_group + 2);
3873 
3874 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3875 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3876 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3877 	for (i = 0; i < ngroups; i++) {
3878 		gdp = ext4_get_group_desc(sb, i, NULL);
3879 		b = ext4_block_bitmap(sb, gdp);
3880 		if (b >= first_block && b <= last_block) {
3881 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3882 			count++;
3883 		}
3884 		b = ext4_inode_bitmap(sb, gdp);
3885 		if (b >= first_block && b <= last_block) {
3886 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3887 			count++;
3888 		}
3889 		b = ext4_inode_table(sb, gdp);
3890 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3891 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3892 				int c = EXT4_B2C(sbi, b - first_block);
3893 				ext4_set_bit(c, buf);
3894 				count++;
3895 			}
3896 		if (i != grp)
3897 			continue;
3898 		s = 0;
3899 		if (ext4_bg_has_super(sb, grp)) {
3900 			ext4_set_bit(s++, buf);
3901 			count++;
3902 		}
3903 		j = ext4_bg_num_gdb(sb, grp);
3904 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3905 			ext4_error(sb, "Invalid number of block group "
3906 				   "descriptor blocks: %d", j);
3907 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3908 		}
3909 		count += j;
3910 		for (; j > 0; j--)
3911 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3912 	}
3913 	if (!count)
3914 		return 0;
3915 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3916 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3917 }
3918 
3919 /*
3920  * Compute the overhead and stash it in sbi->s_overhead
3921  */
3922 int ext4_calculate_overhead(struct super_block *sb)
3923 {
3924 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3925 	struct ext4_super_block *es = sbi->s_es;
3926 	struct inode *j_inode;
3927 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3928 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3929 	ext4_fsblk_t overhead = 0;
3930 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3931 
3932 	if (!buf)
3933 		return -ENOMEM;
3934 
3935 	/*
3936 	 * Compute the overhead (FS structures).  This is constant
3937 	 * for a given filesystem unless the number of block groups
3938 	 * changes so we cache the previous value until it does.
3939 	 */
3940 
3941 	/*
3942 	 * All of the blocks before first_data_block are overhead
3943 	 */
3944 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3945 
3946 	/*
3947 	 * Add the overhead found in each block group
3948 	 */
3949 	for (i = 0; i < ngroups; i++) {
3950 		int blks;
3951 
3952 		blks = count_overhead(sb, i, buf);
3953 		overhead += blks;
3954 		if (blks)
3955 			memset(buf, 0, PAGE_SIZE);
3956 		cond_resched();
3957 	}
3958 
3959 	/*
3960 	 * Add the internal journal blocks whether the journal has been
3961 	 * loaded or not
3962 	 */
3963 	if (sbi->s_journal && !sbi->s_journal_bdev)
3964 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
3965 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3966 		/* j_inum for internal journal is non-zero */
3967 		j_inode = ext4_get_journal_inode(sb, j_inum);
3968 		if (j_inode) {
3969 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3970 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3971 			iput(j_inode);
3972 		} else {
3973 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3974 		}
3975 	}
3976 	sbi->s_overhead = overhead;
3977 	smp_wmb();
3978 	free_page((unsigned long) buf);
3979 	return 0;
3980 }
3981 
3982 static void ext4_set_resv_clusters(struct super_block *sb)
3983 {
3984 	ext4_fsblk_t resv_clusters;
3985 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3986 
3987 	/*
3988 	 * There's no need to reserve anything when we aren't using extents.
3989 	 * The space estimates are exact, there are no unwritten extents,
3990 	 * hole punching doesn't need new metadata... This is needed especially
3991 	 * to keep ext2/3 backward compatibility.
3992 	 */
3993 	if (!ext4_has_feature_extents(sb))
3994 		return;
3995 	/*
3996 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3997 	 * This should cover the situations where we can not afford to run
3998 	 * out of space like for example punch hole, or converting
3999 	 * unwritten extents in delalloc path. In most cases such
4000 	 * allocation would require 1, or 2 blocks, higher numbers are
4001 	 * very rare.
4002 	 */
4003 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4004 			 sbi->s_cluster_bits);
4005 
4006 	do_div(resv_clusters, 50);
4007 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4008 
4009 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4010 }
4011 
4012 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
4013 {
4014 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
4015 	char *orig_data = kstrdup(data, GFP_KERNEL);
4016 	struct buffer_head *bh, **group_desc;
4017 	struct ext4_super_block *es = NULL;
4018 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4019 	struct flex_groups **flex_groups;
4020 	ext4_fsblk_t block;
4021 	ext4_fsblk_t sb_block = get_sb_block(&data);
4022 	ext4_fsblk_t logical_sb_block;
4023 	unsigned long offset = 0;
4024 	unsigned long journal_devnum = 0;
4025 	unsigned long def_mount_opts;
4026 	struct inode *root;
4027 	const char *descr;
4028 	int ret = -ENOMEM;
4029 	int blocksize, clustersize;
4030 	unsigned int db_count;
4031 	unsigned int i;
4032 	int needs_recovery, has_huge_files;
4033 	__u64 blocks_count;
4034 	int err = 0;
4035 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4036 	ext4_group_t first_not_zeroed;
4037 
4038 	if ((data && !orig_data) || !sbi)
4039 		goto out_free_base;
4040 
4041 	sbi->s_daxdev = dax_dev;
4042 	sbi->s_blockgroup_lock =
4043 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4044 	if (!sbi->s_blockgroup_lock)
4045 		goto out_free_base;
4046 
4047 	sb->s_fs_info = sbi;
4048 	sbi->s_sb = sb;
4049 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4050 	sbi->s_sb_block = sb_block;
4051 	if (sb->s_bdev->bd_part)
4052 		sbi->s_sectors_written_start =
4053 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
4054 
4055 	/* Cleanup superblock name */
4056 	strreplace(sb->s_id, '/', '!');
4057 
4058 	/* -EINVAL is default */
4059 	ret = -EINVAL;
4060 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4061 	if (!blocksize) {
4062 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4063 		goto out_fail;
4064 	}
4065 
4066 	/*
4067 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4068 	 * block sizes.  We need to calculate the offset from buffer start.
4069 	 */
4070 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4071 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4072 		offset = do_div(logical_sb_block, blocksize);
4073 	} else {
4074 		logical_sb_block = sb_block;
4075 	}
4076 
4077 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4078 	if (IS_ERR(bh)) {
4079 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4080 		ret = PTR_ERR(bh);
4081 		bh = NULL;
4082 		goto out_fail;
4083 	}
4084 	/*
4085 	 * Note: s_es must be initialized as soon as possible because
4086 	 *       some ext4 macro-instructions depend on its value
4087 	 */
4088 	es = (struct ext4_super_block *) (bh->b_data + offset);
4089 	sbi->s_es = es;
4090 	sb->s_magic = le16_to_cpu(es->s_magic);
4091 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4092 		goto cantfind_ext4;
4093 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4094 
4095 	/* Warn if metadata_csum and gdt_csum are both set. */
4096 	if (ext4_has_feature_metadata_csum(sb) &&
4097 	    ext4_has_feature_gdt_csum(sb))
4098 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4099 			     "redundant flags; please run fsck.");
4100 
4101 	/* Check for a known checksum algorithm */
4102 	if (!ext4_verify_csum_type(sb, es)) {
4103 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4104 			 "unknown checksum algorithm.");
4105 		silent = 1;
4106 		goto cantfind_ext4;
4107 	}
4108 
4109 	/* Load the checksum driver */
4110 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4111 	if (IS_ERR(sbi->s_chksum_driver)) {
4112 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4113 		ret = PTR_ERR(sbi->s_chksum_driver);
4114 		sbi->s_chksum_driver = NULL;
4115 		goto failed_mount;
4116 	}
4117 
4118 	/* Check superblock checksum */
4119 	if (!ext4_superblock_csum_verify(sb, es)) {
4120 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4121 			 "invalid superblock checksum.  Run e2fsck?");
4122 		silent = 1;
4123 		ret = -EFSBADCRC;
4124 		goto cantfind_ext4;
4125 	}
4126 
4127 	/* Precompute checksum seed for all metadata */
4128 	if (ext4_has_feature_csum_seed(sb))
4129 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4130 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4131 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4132 					       sizeof(es->s_uuid));
4133 
4134 	/* Set defaults before we parse the mount options */
4135 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4136 	set_opt(sb, INIT_INODE_TABLE);
4137 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4138 		set_opt(sb, DEBUG);
4139 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4140 		set_opt(sb, GRPID);
4141 	if (def_mount_opts & EXT4_DEFM_UID16)
4142 		set_opt(sb, NO_UID32);
4143 	/* xattr user namespace & acls are now defaulted on */
4144 	set_opt(sb, XATTR_USER);
4145 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4146 	set_opt(sb, POSIX_ACL);
4147 #endif
4148 	if (ext4_has_feature_fast_commit(sb))
4149 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4150 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4151 	if (ext4_has_metadata_csum(sb))
4152 		set_opt(sb, JOURNAL_CHECKSUM);
4153 
4154 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4155 		set_opt(sb, JOURNAL_DATA);
4156 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4157 		set_opt(sb, ORDERED_DATA);
4158 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4159 		set_opt(sb, WRITEBACK_DATA);
4160 
4161 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4162 		set_opt(sb, ERRORS_PANIC);
4163 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4164 		set_opt(sb, ERRORS_CONT);
4165 	else
4166 		set_opt(sb, ERRORS_RO);
4167 	/* block_validity enabled by default; disable with noblock_validity */
4168 	set_opt(sb, BLOCK_VALIDITY);
4169 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4170 		set_opt(sb, DISCARD);
4171 
4172 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4173 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4174 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4175 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4176 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4177 
4178 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4179 		set_opt(sb, BARRIER);
4180 
4181 	/*
4182 	 * enable delayed allocation by default
4183 	 * Use -o nodelalloc to turn it off
4184 	 */
4185 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4186 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4187 		set_opt(sb, DELALLOC);
4188 
4189 	/*
4190 	 * set default s_li_wait_mult for lazyinit, for the case there is
4191 	 * no mount option specified.
4192 	 */
4193 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4194 
4195 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4196 
4197 	if (blocksize == PAGE_SIZE)
4198 		set_opt(sb, DIOREAD_NOLOCK);
4199 
4200 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
4201 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
4202 		ext4_msg(sb, KERN_ERR,
4203 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
4204 			 blocksize, le32_to_cpu(es->s_log_block_size));
4205 		goto failed_mount;
4206 	}
4207 
4208 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4209 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4210 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4211 	} else {
4212 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4213 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4214 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4215 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4216 				 sbi->s_first_ino);
4217 			goto failed_mount;
4218 		}
4219 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4220 		    (!is_power_of_2(sbi->s_inode_size)) ||
4221 		    (sbi->s_inode_size > blocksize)) {
4222 			ext4_msg(sb, KERN_ERR,
4223 			       "unsupported inode size: %d",
4224 			       sbi->s_inode_size);
4225 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4226 			goto failed_mount;
4227 		}
4228 		/*
4229 		 * i_atime_extra is the last extra field available for
4230 		 * [acm]times in struct ext4_inode. Checking for that
4231 		 * field should suffice to ensure we have extra space
4232 		 * for all three.
4233 		 */
4234 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4235 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4236 			sb->s_time_gran = 1;
4237 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4238 		} else {
4239 			sb->s_time_gran = NSEC_PER_SEC;
4240 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4241 		}
4242 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4243 	}
4244 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4245 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4246 			EXT4_GOOD_OLD_INODE_SIZE;
4247 		if (ext4_has_feature_extra_isize(sb)) {
4248 			unsigned v, max = (sbi->s_inode_size -
4249 					   EXT4_GOOD_OLD_INODE_SIZE);
4250 
4251 			v = le16_to_cpu(es->s_want_extra_isize);
4252 			if (v > max) {
4253 				ext4_msg(sb, KERN_ERR,
4254 					 "bad s_want_extra_isize: %d", v);
4255 				goto failed_mount;
4256 			}
4257 			if (sbi->s_want_extra_isize < v)
4258 				sbi->s_want_extra_isize = v;
4259 
4260 			v = le16_to_cpu(es->s_min_extra_isize);
4261 			if (v > max) {
4262 				ext4_msg(sb, KERN_ERR,
4263 					 "bad s_min_extra_isize: %d", v);
4264 				goto failed_mount;
4265 			}
4266 			if (sbi->s_want_extra_isize < v)
4267 				sbi->s_want_extra_isize = v;
4268 		}
4269 	}
4270 
4271 	if (sbi->s_es->s_mount_opts[0]) {
4272 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4273 					      sizeof(sbi->s_es->s_mount_opts),
4274 					      GFP_KERNEL);
4275 		if (!s_mount_opts)
4276 			goto failed_mount;
4277 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
4278 				   &journal_ioprio, 0)) {
4279 			ext4_msg(sb, KERN_WARNING,
4280 				 "failed to parse options in superblock: %s",
4281 				 s_mount_opts);
4282 		}
4283 		kfree(s_mount_opts);
4284 	}
4285 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4286 	if (!parse_options((char *) data, sb, &journal_devnum,
4287 			   &journal_ioprio, 0))
4288 		goto failed_mount;
4289 
4290 #ifdef CONFIG_UNICODE
4291 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4292 		const struct ext4_sb_encodings *encoding_info;
4293 		struct unicode_map *encoding;
4294 		__u16 encoding_flags;
4295 
4296 		if (ext4_has_feature_encrypt(sb)) {
4297 			ext4_msg(sb, KERN_ERR,
4298 				 "Can't mount with encoding and encryption");
4299 			goto failed_mount;
4300 		}
4301 
4302 		if (ext4_sb_read_encoding(es, &encoding_info,
4303 					  &encoding_flags)) {
4304 			ext4_msg(sb, KERN_ERR,
4305 				 "Encoding requested by superblock is unknown");
4306 			goto failed_mount;
4307 		}
4308 
4309 		encoding = utf8_load(encoding_info->version);
4310 		if (IS_ERR(encoding)) {
4311 			ext4_msg(sb, KERN_ERR,
4312 				 "can't mount with superblock charset: %s-%s "
4313 				 "not supported by the kernel. flags: 0x%x.",
4314 				 encoding_info->name, encoding_info->version,
4315 				 encoding_flags);
4316 			goto failed_mount;
4317 		}
4318 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4319 			 "%s-%s with flags 0x%hx", encoding_info->name,
4320 			 encoding_info->version?:"\b", encoding_flags);
4321 
4322 		sb->s_encoding = encoding;
4323 		sb->s_encoding_flags = encoding_flags;
4324 	}
4325 #endif
4326 
4327 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4328 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4329 		/* can't mount with both data=journal and dioread_nolock. */
4330 		clear_opt(sb, DIOREAD_NOLOCK);
4331 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4332 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4333 			ext4_msg(sb, KERN_ERR, "can't mount with "
4334 				 "both data=journal and delalloc");
4335 			goto failed_mount;
4336 		}
4337 		if (test_opt(sb, DAX_ALWAYS)) {
4338 			ext4_msg(sb, KERN_ERR, "can't mount with "
4339 				 "both data=journal and dax");
4340 			goto failed_mount;
4341 		}
4342 		if (ext4_has_feature_encrypt(sb)) {
4343 			ext4_msg(sb, KERN_WARNING,
4344 				 "encrypted files will use data=ordered "
4345 				 "instead of data journaling mode");
4346 		}
4347 		if (test_opt(sb, DELALLOC))
4348 			clear_opt(sb, DELALLOC);
4349 	} else {
4350 		sb->s_iflags |= SB_I_CGROUPWB;
4351 	}
4352 
4353 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4354 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4355 
4356 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4357 	    (ext4_has_compat_features(sb) ||
4358 	     ext4_has_ro_compat_features(sb) ||
4359 	     ext4_has_incompat_features(sb)))
4360 		ext4_msg(sb, KERN_WARNING,
4361 		       "feature flags set on rev 0 fs, "
4362 		       "running e2fsck is recommended");
4363 
4364 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4365 		set_opt2(sb, HURD_COMPAT);
4366 		if (ext4_has_feature_64bit(sb)) {
4367 			ext4_msg(sb, KERN_ERR,
4368 				 "The Hurd can't support 64-bit file systems");
4369 			goto failed_mount;
4370 		}
4371 
4372 		/*
4373 		 * ea_inode feature uses l_i_version field which is not
4374 		 * available in HURD_COMPAT mode.
4375 		 */
4376 		if (ext4_has_feature_ea_inode(sb)) {
4377 			ext4_msg(sb, KERN_ERR,
4378 				 "ea_inode feature is not supported for Hurd");
4379 			goto failed_mount;
4380 		}
4381 	}
4382 
4383 	if (IS_EXT2_SB(sb)) {
4384 		if (ext2_feature_set_ok(sb))
4385 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4386 				 "using the ext4 subsystem");
4387 		else {
4388 			/*
4389 			 * If we're probing be silent, if this looks like
4390 			 * it's actually an ext[34] filesystem.
4391 			 */
4392 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4393 				goto failed_mount;
4394 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4395 				 "to feature incompatibilities");
4396 			goto failed_mount;
4397 		}
4398 	}
4399 
4400 	if (IS_EXT3_SB(sb)) {
4401 		if (ext3_feature_set_ok(sb))
4402 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4403 				 "using the ext4 subsystem");
4404 		else {
4405 			/*
4406 			 * If we're probing be silent, if this looks like
4407 			 * it's actually an ext4 filesystem.
4408 			 */
4409 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4410 				goto failed_mount;
4411 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4412 				 "to feature incompatibilities");
4413 			goto failed_mount;
4414 		}
4415 	}
4416 
4417 	/*
4418 	 * Check feature flags regardless of the revision level, since we
4419 	 * previously didn't change the revision level when setting the flags,
4420 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4421 	 */
4422 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4423 		goto failed_mount;
4424 
4425 	if (le32_to_cpu(es->s_log_block_size) >
4426 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4427 		ext4_msg(sb, KERN_ERR,
4428 			 "Invalid log block size: %u",
4429 			 le32_to_cpu(es->s_log_block_size));
4430 		goto failed_mount;
4431 	}
4432 	if (le32_to_cpu(es->s_log_cluster_size) >
4433 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4434 		ext4_msg(sb, KERN_ERR,
4435 			 "Invalid log cluster size: %u",
4436 			 le32_to_cpu(es->s_log_cluster_size));
4437 		goto failed_mount;
4438 	}
4439 
4440 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4441 		ext4_msg(sb, KERN_ERR,
4442 			 "Number of reserved GDT blocks insanely large: %d",
4443 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4444 		goto failed_mount;
4445 	}
4446 
4447 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4448 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4449 
4450 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4451 		if (ext4_has_feature_inline_data(sb)) {
4452 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4453 					" that may contain inline data");
4454 			goto failed_mount;
4455 		}
4456 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4457 			ext4_msg(sb, KERN_ERR,
4458 				"DAX unsupported by block device.");
4459 			goto failed_mount;
4460 		}
4461 	}
4462 
4463 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4464 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4465 			 es->s_encryption_level);
4466 		goto failed_mount;
4467 	}
4468 
4469 	if (sb->s_blocksize != blocksize) {
4470 		/* Validate the filesystem blocksize */
4471 		if (!sb_set_blocksize(sb, blocksize)) {
4472 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4473 					blocksize);
4474 			goto failed_mount;
4475 		}
4476 
4477 		brelse(bh);
4478 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4479 		offset = do_div(logical_sb_block, blocksize);
4480 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4481 		if (IS_ERR(bh)) {
4482 			ext4_msg(sb, KERN_ERR,
4483 			       "Can't read superblock on 2nd try");
4484 			ret = PTR_ERR(bh);
4485 			bh = NULL;
4486 			goto failed_mount;
4487 		}
4488 		es = (struct ext4_super_block *)(bh->b_data + offset);
4489 		sbi->s_es = es;
4490 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4491 			ext4_msg(sb, KERN_ERR,
4492 			       "Magic mismatch, very weird!");
4493 			goto failed_mount;
4494 		}
4495 	}
4496 
4497 	has_huge_files = ext4_has_feature_huge_file(sb);
4498 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4499 						      has_huge_files);
4500 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4501 
4502 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4503 	if (ext4_has_feature_64bit(sb)) {
4504 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4505 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4506 		    !is_power_of_2(sbi->s_desc_size)) {
4507 			ext4_msg(sb, KERN_ERR,
4508 			       "unsupported descriptor size %lu",
4509 			       sbi->s_desc_size);
4510 			goto failed_mount;
4511 		}
4512 	} else
4513 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4514 
4515 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4516 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4517 
4518 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4519 	if (sbi->s_inodes_per_block == 0)
4520 		goto cantfind_ext4;
4521 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4522 	    sbi->s_inodes_per_group > blocksize * 8) {
4523 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4524 			 sbi->s_inodes_per_group);
4525 		goto failed_mount;
4526 	}
4527 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4528 					sbi->s_inodes_per_block;
4529 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4530 	sbi->s_sbh = bh;
4531 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4532 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4533 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4534 
4535 	for (i = 0; i < 4; i++)
4536 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4537 	sbi->s_def_hash_version = es->s_def_hash_version;
4538 	if (ext4_has_feature_dir_index(sb)) {
4539 		i = le32_to_cpu(es->s_flags);
4540 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4541 			sbi->s_hash_unsigned = 3;
4542 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4543 #ifdef __CHAR_UNSIGNED__
4544 			if (!sb_rdonly(sb))
4545 				es->s_flags |=
4546 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4547 			sbi->s_hash_unsigned = 3;
4548 #else
4549 			if (!sb_rdonly(sb))
4550 				es->s_flags |=
4551 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4552 #endif
4553 		}
4554 	}
4555 
4556 	/* Handle clustersize */
4557 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4558 	if (ext4_has_feature_bigalloc(sb)) {
4559 		if (clustersize < blocksize) {
4560 			ext4_msg(sb, KERN_ERR,
4561 				 "cluster size (%d) smaller than "
4562 				 "block size (%d)", clustersize, blocksize);
4563 			goto failed_mount;
4564 		}
4565 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4566 			le32_to_cpu(es->s_log_block_size);
4567 		sbi->s_clusters_per_group =
4568 			le32_to_cpu(es->s_clusters_per_group);
4569 		if (sbi->s_clusters_per_group > blocksize * 8) {
4570 			ext4_msg(sb, KERN_ERR,
4571 				 "#clusters per group too big: %lu",
4572 				 sbi->s_clusters_per_group);
4573 			goto failed_mount;
4574 		}
4575 		if (sbi->s_blocks_per_group !=
4576 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4577 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4578 				 "clusters per group (%lu) inconsistent",
4579 				 sbi->s_blocks_per_group,
4580 				 sbi->s_clusters_per_group);
4581 			goto failed_mount;
4582 		}
4583 	} else {
4584 		if (clustersize != blocksize) {
4585 			ext4_msg(sb, KERN_ERR,
4586 				 "fragment/cluster size (%d) != "
4587 				 "block size (%d)", clustersize, blocksize);
4588 			goto failed_mount;
4589 		}
4590 		if (sbi->s_blocks_per_group > blocksize * 8) {
4591 			ext4_msg(sb, KERN_ERR,
4592 				 "#blocks per group too big: %lu",
4593 				 sbi->s_blocks_per_group);
4594 			goto failed_mount;
4595 		}
4596 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4597 		sbi->s_cluster_bits = 0;
4598 	}
4599 	sbi->s_cluster_ratio = clustersize / blocksize;
4600 
4601 	/* Do we have standard group size of clustersize * 8 blocks ? */
4602 	if (sbi->s_blocks_per_group == clustersize << 3)
4603 		set_opt2(sb, STD_GROUP_SIZE);
4604 
4605 	/*
4606 	 * Test whether we have more sectors than will fit in sector_t,
4607 	 * and whether the max offset is addressable by the page cache.
4608 	 */
4609 	err = generic_check_addressable(sb->s_blocksize_bits,
4610 					ext4_blocks_count(es));
4611 	if (err) {
4612 		ext4_msg(sb, KERN_ERR, "filesystem"
4613 			 " too large to mount safely on this system");
4614 		goto failed_mount;
4615 	}
4616 
4617 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4618 		goto cantfind_ext4;
4619 
4620 	/* check blocks count against device size */
4621 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4622 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4623 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4624 		       "exceeds size of device (%llu blocks)",
4625 		       ext4_blocks_count(es), blocks_count);
4626 		goto failed_mount;
4627 	}
4628 
4629 	/*
4630 	 * It makes no sense for the first data block to be beyond the end
4631 	 * of the filesystem.
4632 	 */
4633 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4634 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4635 			 "block %u is beyond end of filesystem (%llu)",
4636 			 le32_to_cpu(es->s_first_data_block),
4637 			 ext4_blocks_count(es));
4638 		goto failed_mount;
4639 	}
4640 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4641 	    (sbi->s_cluster_ratio == 1)) {
4642 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4643 			 "block is 0 with a 1k block and cluster size");
4644 		goto failed_mount;
4645 	}
4646 
4647 	blocks_count = (ext4_blocks_count(es) -
4648 			le32_to_cpu(es->s_first_data_block) +
4649 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4650 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4651 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4652 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4653 		       "(block count %llu, first data block %u, "
4654 		       "blocks per group %lu)", blocks_count,
4655 		       ext4_blocks_count(es),
4656 		       le32_to_cpu(es->s_first_data_block),
4657 		       EXT4_BLOCKS_PER_GROUP(sb));
4658 		goto failed_mount;
4659 	}
4660 	sbi->s_groups_count = blocks_count;
4661 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4662 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4663 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4664 	    le32_to_cpu(es->s_inodes_count)) {
4665 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4666 			 le32_to_cpu(es->s_inodes_count),
4667 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4668 		ret = -EINVAL;
4669 		goto failed_mount;
4670 	}
4671 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4672 		   EXT4_DESC_PER_BLOCK(sb);
4673 	if (ext4_has_feature_meta_bg(sb)) {
4674 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4675 			ext4_msg(sb, KERN_WARNING,
4676 				 "first meta block group too large: %u "
4677 				 "(group descriptor block count %u)",
4678 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4679 			goto failed_mount;
4680 		}
4681 	}
4682 	rcu_assign_pointer(sbi->s_group_desc,
4683 			   kvmalloc_array(db_count,
4684 					  sizeof(struct buffer_head *),
4685 					  GFP_KERNEL));
4686 	if (sbi->s_group_desc == NULL) {
4687 		ext4_msg(sb, KERN_ERR, "not enough memory");
4688 		ret = -ENOMEM;
4689 		goto failed_mount;
4690 	}
4691 
4692 	bgl_lock_init(sbi->s_blockgroup_lock);
4693 
4694 	/* Pre-read the descriptors into the buffer cache */
4695 	for (i = 0; i < db_count; i++) {
4696 		block = descriptor_loc(sb, logical_sb_block, i);
4697 		ext4_sb_breadahead_unmovable(sb, block);
4698 	}
4699 
4700 	for (i = 0; i < db_count; i++) {
4701 		struct buffer_head *bh;
4702 
4703 		block = descriptor_loc(sb, logical_sb_block, i);
4704 		bh = ext4_sb_bread_unmovable(sb, block);
4705 		if (IS_ERR(bh)) {
4706 			ext4_msg(sb, KERN_ERR,
4707 			       "can't read group descriptor %d", i);
4708 			db_count = i;
4709 			ret = PTR_ERR(bh);
4710 			bh = NULL;
4711 			goto failed_mount2;
4712 		}
4713 		rcu_read_lock();
4714 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4715 		rcu_read_unlock();
4716 	}
4717 	sbi->s_gdb_count = db_count;
4718 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4719 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4720 		ret = -EFSCORRUPTED;
4721 		goto failed_mount2;
4722 	}
4723 
4724 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4725 
4726 	/* Register extent status tree shrinker */
4727 	if (ext4_es_register_shrinker(sbi))
4728 		goto failed_mount3;
4729 
4730 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4731 	sbi->s_extent_max_zeroout_kb = 32;
4732 
4733 	/*
4734 	 * set up enough so that it can read an inode
4735 	 */
4736 	sb->s_op = &ext4_sops;
4737 	sb->s_export_op = &ext4_export_ops;
4738 	sb->s_xattr = ext4_xattr_handlers;
4739 #ifdef CONFIG_FS_ENCRYPTION
4740 	sb->s_cop = &ext4_cryptops;
4741 #endif
4742 #ifdef CONFIG_FS_VERITY
4743 	sb->s_vop = &ext4_verityops;
4744 #endif
4745 #ifdef CONFIG_QUOTA
4746 	sb->dq_op = &ext4_quota_operations;
4747 	if (ext4_has_feature_quota(sb))
4748 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4749 	else
4750 		sb->s_qcop = &ext4_qctl_operations;
4751 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4752 #endif
4753 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4754 
4755 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4756 	mutex_init(&sbi->s_orphan_lock);
4757 
4758 	/* Initialize fast commit stuff */
4759 	atomic_set(&sbi->s_fc_subtid, 0);
4760 	atomic_set(&sbi->s_fc_ineligible_updates, 0);
4761 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4762 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4763 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4764 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4765 	sbi->s_fc_bytes = 0;
4766 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4767 	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
4768 	spin_lock_init(&sbi->s_fc_lock);
4769 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4770 	sbi->s_fc_replay_state.fc_regions = NULL;
4771 	sbi->s_fc_replay_state.fc_regions_size = 0;
4772 	sbi->s_fc_replay_state.fc_regions_used = 0;
4773 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4774 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4775 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4776 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4777 
4778 	sb->s_root = NULL;
4779 
4780 	needs_recovery = (es->s_last_orphan != 0 ||
4781 			  ext4_has_feature_journal_needs_recovery(sb));
4782 
4783 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4784 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4785 			goto failed_mount3a;
4786 
4787 	/*
4788 	 * The first inode we look at is the journal inode.  Don't try
4789 	 * root first: it may be modified in the journal!
4790 	 */
4791 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4792 		err = ext4_load_journal(sb, es, journal_devnum);
4793 		if (err)
4794 			goto failed_mount3a;
4795 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4796 		   ext4_has_feature_journal_needs_recovery(sb)) {
4797 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4798 		       "suppressed and not mounted read-only");
4799 		goto failed_mount_wq;
4800 	} else {
4801 		/* Nojournal mode, all journal mount options are illegal */
4802 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4803 			ext4_msg(sb, KERN_ERR, "can't mount with "
4804 				 "journal_checksum, fs mounted w/o journal");
4805 			goto failed_mount_wq;
4806 		}
4807 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4808 			ext4_msg(sb, KERN_ERR, "can't mount with "
4809 				 "journal_async_commit, fs mounted w/o journal");
4810 			goto failed_mount_wq;
4811 		}
4812 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4813 			ext4_msg(sb, KERN_ERR, "can't mount with "
4814 				 "commit=%lu, fs mounted w/o journal",
4815 				 sbi->s_commit_interval / HZ);
4816 			goto failed_mount_wq;
4817 		}
4818 		if (EXT4_MOUNT_DATA_FLAGS &
4819 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4820 			ext4_msg(sb, KERN_ERR, "can't mount with "
4821 				 "data=, fs mounted w/o journal");
4822 			goto failed_mount_wq;
4823 		}
4824 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4825 		clear_opt(sb, JOURNAL_CHECKSUM);
4826 		clear_opt(sb, DATA_FLAGS);
4827 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4828 		sbi->s_journal = NULL;
4829 		needs_recovery = 0;
4830 		goto no_journal;
4831 	}
4832 
4833 	if (ext4_has_feature_64bit(sb) &&
4834 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4835 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4836 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4837 		goto failed_mount_wq;
4838 	}
4839 
4840 	if (!set_journal_csum_feature_set(sb)) {
4841 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4842 			 "feature set");
4843 		goto failed_mount_wq;
4844 	}
4845 
4846 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4847 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4848 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4849 		ext4_msg(sb, KERN_ERR,
4850 			"Failed to set fast commit journal feature");
4851 		goto failed_mount_wq;
4852 	}
4853 
4854 	/* We have now updated the journal if required, so we can
4855 	 * validate the data journaling mode. */
4856 	switch (test_opt(sb, DATA_FLAGS)) {
4857 	case 0:
4858 		/* No mode set, assume a default based on the journal
4859 		 * capabilities: ORDERED_DATA if the journal can
4860 		 * cope, else JOURNAL_DATA
4861 		 */
4862 		if (jbd2_journal_check_available_features
4863 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4864 			set_opt(sb, ORDERED_DATA);
4865 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4866 		} else {
4867 			set_opt(sb, JOURNAL_DATA);
4868 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4869 		}
4870 		break;
4871 
4872 	case EXT4_MOUNT_ORDERED_DATA:
4873 	case EXT4_MOUNT_WRITEBACK_DATA:
4874 		if (!jbd2_journal_check_available_features
4875 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4876 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4877 			       "requested data journaling mode");
4878 			goto failed_mount_wq;
4879 		}
4880 	default:
4881 		break;
4882 	}
4883 
4884 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4885 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4886 		ext4_msg(sb, KERN_ERR, "can't mount with "
4887 			"journal_async_commit in data=ordered mode");
4888 		goto failed_mount_wq;
4889 	}
4890 
4891 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4892 
4893 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4894 	sbi->s_journal->j_submit_inode_data_buffers =
4895 		ext4_journal_submit_inode_data_buffers;
4896 	sbi->s_journal->j_finish_inode_data_buffers =
4897 		ext4_journal_finish_inode_data_buffers;
4898 
4899 no_journal:
4900 	if (!test_opt(sb, NO_MBCACHE)) {
4901 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4902 		if (!sbi->s_ea_block_cache) {
4903 			ext4_msg(sb, KERN_ERR,
4904 				 "Failed to create ea_block_cache");
4905 			goto failed_mount_wq;
4906 		}
4907 
4908 		if (ext4_has_feature_ea_inode(sb)) {
4909 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4910 			if (!sbi->s_ea_inode_cache) {
4911 				ext4_msg(sb, KERN_ERR,
4912 					 "Failed to create ea_inode_cache");
4913 				goto failed_mount_wq;
4914 			}
4915 		}
4916 	}
4917 
4918 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4919 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4920 		goto failed_mount_wq;
4921 	}
4922 
4923 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4924 	    !ext4_has_feature_encrypt(sb)) {
4925 		ext4_set_feature_encrypt(sb);
4926 		ext4_commit_super(sb, 1);
4927 	}
4928 
4929 	/*
4930 	 * Get the # of file system overhead blocks from the
4931 	 * superblock if present.
4932 	 */
4933 	if (es->s_overhead_clusters)
4934 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4935 	else {
4936 		err = ext4_calculate_overhead(sb);
4937 		if (err)
4938 			goto failed_mount_wq;
4939 	}
4940 
4941 	/*
4942 	 * The maximum number of concurrent works can be high and
4943 	 * concurrency isn't really necessary.  Limit it to 1.
4944 	 */
4945 	EXT4_SB(sb)->rsv_conversion_wq =
4946 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4947 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4948 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4949 		ret = -ENOMEM;
4950 		goto failed_mount4;
4951 	}
4952 
4953 	/*
4954 	 * The jbd2_journal_load will have done any necessary log recovery,
4955 	 * so we can safely mount the rest of the filesystem now.
4956 	 */
4957 
4958 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4959 	if (IS_ERR(root)) {
4960 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4961 		ret = PTR_ERR(root);
4962 		root = NULL;
4963 		goto failed_mount4;
4964 	}
4965 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4966 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4967 		iput(root);
4968 		goto failed_mount4;
4969 	}
4970 
4971 #ifdef CONFIG_UNICODE
4972 	if (sb->s_encoding)
4973 		sb->s_d_op = &ext4_dentry_ops;
4974 #endif
4975 
4976 	sb->s_root = d_make_root(root);
4977 	if (!sb->s_root) {
4978 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4979 		ret = -ENOMEM;
4980 		goto failed_mount4;
4981 	}
4982 
4983 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4984 	if (ret == -EROFS) {
4985 		sb->s_flags |= SB_RDONLY;
4986 		ret = 0;
4987 	} else if (ret)
4988 		goto failed_mount4a;
4989 
4990 	ext4_set_resv_clusters(sb);
4991 
4992 	if (test_opt(sb, BLOCK_VALIDITY)) {
4993 		err = ext4_setup_system_zone(sb);
4994 		if (err) {
4995 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
4996 				 "zone (%d)", err);
4997 			goto failed_mount4a;
4998 		}
4999 	}
5000 	ext4_fc_replay_cleanup(sb);
5001 
5002 	ext4_ext_init(sb);
5003 	err = ext4_mb_init(sb);
5004 	if (err) {
5005 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5006 			 err);
5007 		goto failed_mount5;
5008 	}
5009 
5010 	block = ext4_count_free_clusters(sb);
5011 	ext4_free_blocks_count_set(sbi->s_es,
5012 				   EXT4_C2B(sbi, block));
5013 	ext4_superblock_csum_set(sb);
5014 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5015 				  GFP_KERNEL);
5016 	if (!err) {
5017 		unsigned long freei = ext4_count_free_inodes(sb);
5018 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5019 		ext4_superblock_csum_set(sb);
5020 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5021 					  GFP_KERNEL);
5022 	}
5023 	if (!err)
5024 		err = percpu_counter_init(&sbi->s_dirs_counter,
5025 					  ext4_count_dirs(sb), GFP_KERNEL);
5026 	if (!err)
5027 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5028 					  GFP_KERNEL);
5029 	if (!err)
5030 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5031 
5032 	if (err) {
5033 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5034 		goto failed_mount6;
5035 	}
5036 
5037 	if (ext4_has_feature_flex_bg(sb))
5038 		if (!ext4_fill_flex_info(sb)) {
5039 			ext4_msg(sb, KERN_ERR,
5040 			       "unable to initialize "
5041 			       "flex_bg meta info!");
5042 			goto failed_mount6;
5043 		}
5044 
5045 	err = ext4_register_li_request(sb, first_not_zeroed);
5046 	if (err)
5047 		goto failed_mount6;
5048 
5049 	err = ext4_register_sysfs(sb);
5050 	if (err)
5051 		goto failed_mount7;
5052 
5053 #ifdef CONFIG_QUOTA
5054 	/* Enable quota usage during mount. */
5055 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5056 		err = ext4_enable_quotas(sb);
5057 		if (err)
5058 			goto failed_mount8;
5059 	}
5060 #endif  /* CONFIG_QUOTA */
5061 
5062 	/*
5063 	 * Save the original bdev mapping's wb_err value which could be
5064 	 * used to detect the metadata async write error.
5065 	 */
5066 	spin_lock_init(&sbi->s_bdev_wb_lock);
5067 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5068 				 &sbi->s_bdev_wb_err);
5069 	sb->s_bdev->bd_super = sb;
5070 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5071 	ext4_orphan_cleanup(sb, es);
5072 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5073 	if (needs_recovery) {
5074 		ext4_msg(sb, KERN_INFO, "recovery complete");
5075 		err = ext4_mark_recovery_complete(sb, es);
5076 		if (err)
5077 			goto failed_mount8;
5078 	}
5079 	if (EXT4_SB(sb)->s_journal) {
5080 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5081 			descr = " journalled data mode";
5082 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5083 			descr = " ordered data mode";
5084 		else
5085 			descr = " writeback data mode";
5086 	} else
5087 		descr = "out journal";
5088 
5089 	if (test_opt(sb, DISCARD)) {
5090 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5091 		if (!blk_queue_discard(q))
5092 			ext4_msg(sb, KERN_WARNING,
5093 				 "mounting with \"discard\" option, but "
5094 				 "the device does not support discard");
5095 	}
5096 
5097 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5098 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5099 			 "Opts: %.*s%s%s", descr,
5100 			 (int) sizeof(sbi->s_es->s_mount_opts),
5101 			 sbi->s_es->s_mount_opts,
5102 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
5103 
5104 	if (es->s_error_count)
5105 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5106 
5107 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5108 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5109 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5110 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5111 	atomic_set(&sbi->s_warning_count, 0);
5112 	atomic_set(&sbi->s_msg_count, 0);
5113 
5114 	kfree(orig_data);
5115 	return 0;
5116 
5117 cantfind_ext4:
5118 	if (!silent)
5119 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5120 	goto failed_mount;
5121 
5122 failed_mount8:
5123 	ext4_unregister_sysfs(sb);
5124 	kobject_put(&sbi->s_kobj);
5125 failed_mount7:
5126 	ext4_unregister_li_request(sb);
5127 failed_mount6:
5128 	ext4_mb_release(sb);
5129 	rcu_read_lock();
5130 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5131 	if (flex_groups) {
5132 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5133 			kvfree(flex_groups[i]);
5134 		kvfree(flex_groups);
5135 	}
5136 	rcu_read_unlock();
5137 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5138 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5139 	percpu_counter_destroy(&sbi->s_dirs_counter);
5140 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5141 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5142 failed_mount5:
5143 	ext4_ext_release(sb);
5144 	ext4_release_system_zone(sb);
5145 failed_mount4a:
5146 	dput(sb->s_root);
5147 	sb->s_root = NULL;
5148 failed_mount4:
5149 	ext4_msg(sb, KERN_ERR, "mount failed");
5150 	if (EXT4_SB(sb)->rsv_conversion_wq)
5151 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5152 failed_mount_wq:
5153 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5154 	sbi->s_ea_inode_cache = NULL;
5155 
5156 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5157 	sbi->s_ea_block_cache = NULL;
5158 
5159 	if (sbi->s_journal) {
5160 		jbd2_journal_destroy(sbi->s_journal);
5161 		sbi->s_journal = NULL;
5162 	}
5163 failed_mount3a:
5164 	ext4_es_unregister_shrinker(sbi);
5165 failed_mount3:
5166 	del_timer_sync(&sbi->s_err_report);
5167 	if (sbi->s_mmp_tsk)
5168 		kthread_stop(sbi->s_mmp_tsk);
5169 failed_mount2:
5170 	rcu_read_lock();
5171 	group_desc = rcu_dereference(sbi->s_group_desc);
5172 	for (i = 0; i < db_count; i++)
5173 		brelse(group_desc[i]);
5174 	kvfree(group_desc);
5175 	rcu_read_unlock();
5176 failed_mount:
5177 	if (sbi->s_chksum_driver)
5178 		crypto_free_shash(sbi->s_chksum_driver);
5179 
5180 #ifdef CONFIG_UNICODE
5181 	utf8_unload(sb->s_encoding);
5182 #endif
5183 
5184 #ifdef CONFIG_QUOTA
5185 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5186 		kfree(get_qf_name(sb, sbi, i));
5187 #endif
5188 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5189 	ext4_blkdev_remove(sbi);
5190 	brelse(bh);
5191 out_fail:
5192 	sb->s_fs_info = NULL;
5193 	kfree(sbi->s_blockgroup_lock);
5194 out_free_base:
5195 	kfree(sbi);
5196 	kfree(orig_data);
5197 	fs_put_dax(dax_dev);
5198 	return err ? err : ret;
5199 }
5200 
5201 /*
5202  * Setup any per-fs journal parameters now.  We'll do this both on
5203  * initial mount, once the journal has been initialised but before we've
5204  * done any recovery; and again on any subsequent remount.
5205  */
5206 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5207 {
5208 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5209 
5210 	journal->j_commit_interval = sbi->s_commit_interval;
5211 	journal->j_min_batch_time = sbi->s_min_batch_time;
5212 	journal->j_max_batch_time = sbi->s_max_batch_time;
5213 	ext4_fc_init(sb, journal);
5214 
5215 	write_lock(&journal->j_state_lock);
5216 	if (test_opt(sb, BARRIER))
5217 		journal->j_flags |= JBD2_BARRIER;
5218 	else
5219 		journal->j_flags &= ~JBD2_BARRIER;
5220 	if (test_opt(sb, DATA_ERR_ABORT))
5221 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5222 	else
5223 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5224 	write_unlock(&journal->j_state_lock);
5225 }
5226 
5227 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5228 					     unsigned int journal_inum)
5229 {
5230 	struct inode *journal_inode;
5231 
5232 	/*
5233 	 * Test for the existence of a valid inode on disk.  Bad things
5234 	 * happen if we iget() an unused inode, as the subsequent iput()
5235 	 * will try to delete it.
5236 	 */
5237 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5238 	if (IS_ERR(journal_inode)) {
5239 		ext4_msg(sb, KERN_ERR, "no journal found");
5240 		return NULL;
5241 	}
5242 	if (!journal_inode->i_nlink) {
5243 		make_bad_inode(journal_inode);
5244 		iput(journal_inode);
5245 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5246 		return NULL;
5247 	}
5248 
5249 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5250 		  journal_inode, journal_inode->i_size);
5251 	if (!S_ISREG(journal_inode->i_mode)) {
5252 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5253 		iput(journal_inode);
5254 		return NULL;
5255 	}
5256 	return journal_inode;
5257 }
5258 
5259 static journal_t *ext4_get_journal(struct super_block *sb,
5260 				   unsigned int journal_inum)
5261 {
5262 	struct inode *journal_inode;
5263 	journal_t *journal;
5264 
5265 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5266 		return NULL;
5267 
5268 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5269 	if (!journal_inode)
5270 		return NULL;
5271 
5272 	journal = jbd2_journal_init_inode(journal_inode);
5273 	if (!journal) {
5274 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5275 		iput(journal_inode);
5276 		return NULL;
5277 	}
5278 	journal->j_private = sb;
5279 	ext4_init_journal_params(sb, journal);
5280 	return journal;
5281 }
5282 
5283 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5284 				       dev_t j_dev)
5285 {
5286 	struct buffer_head *bh;
5287 	journal_t *journal;
5288 	ext4_fsblk_t start;
5289 	ext4_fsblk_t len;
5290 	int hblock, blocksize;
5291 	ext4_fsblk_t sb_block;
5292 	unsigned long offset;
5293 	struct ext4_super_block *es;
5294 	struct block_device *bdev;
5295 
5296 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5297 		return NULL;
5298 
5299 	bdev = ext4_blkdev_get(j_dev, sb);
5300 	if (bdev == NULL)
5301 		return NULL;
5302 
5303 	blocksize = sb->s_blocksize;
5304 	hblock = bdev_logical_block_size(bdev);
5305 	if (blocksize < hblock) {
5306 		ext4_msg(sb, KERN_ERR,
5307 			"blocksize too small for journal device");
5308 		goto out_bdev;
5309 	}
5310 
5311 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5312 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5313 	set_blocksize(bdev, blocksize);
5314 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5315 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5316 		       "external journal");
5317 		goto out_bdev;
5318 	}
5319 
5320 	es = (struct ext4_super_block *) (bh->b_data + offset);
5321 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5322 	    !(le32_to_cpu(es->s_feature_incompat) &
5323 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5324 		ext4_msg(sb, KERN_ERR, "external journal has "
5325 					"bad superblock");
5326 		brelse(bh);
5327 		goto out_bdev;
5328 	}
5329 
5330 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5331 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5332 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5333 		ext4_msg(sb, KERN_ERR, "external journal has "
5334 				       "corrupt superblock");
5335 		brelse(bh);
5336 		goto out_bdev;
5337 	}
5338 
5339 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5340 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5341 		brelse(bh);
5342 		goto out_bdev;
5343 	}
5344 
5345 	len = ext4_blocks_count(es);
5346 	start = sb_block + 1;
5347 	brelse(bh);	/* we're done with the superblock */
5348 
5349 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5350 					start, len, blocksize);
5351 	if (!journal) {
5352 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5353 		goto out_bdev;
5354 	}
5355 	journal->j_private = sb;
5356 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5357 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5358 		goto out_journal;
5359 	}
5360 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5361 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5362 					"user (unsupported) - %d",
5363 			be32_to_cpu(journal->j_superblock->s_nr_users));
5364 		goto out_journal;
5365 	}
5366 	EXT4_SB(sb)->s_journal_bdev = bdev;
5367 	ext4_init_journal_params(sb, journal);
5368 	return journal;
5369 
5370 out_journal:
5371 	jbd2_journal_destroy(journal);
5372 out_bdev:
5373 	ext4_blkdev_put(bdev);
5374 	return NULL;
5375 }
5376 
5377 static int ext4_load_journal(struct super_block *sb,
5378 			     struct ext4_super_block *es,
5379 			     unsigned long journal_devnum)
5380 {
5381 	journal_t *journal;
5382 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5383 	dev_t journal_dev;
5384 	int err = 0;
5385 	int really_read_only;
5386 	int journal_dev_ro;
5387 
5388 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5389 		return -EFSCORRUPTED;
5390 
5391 	if (journal_devnum &&
5392 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5393 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5394 			"numbers have changed");
5395 		journal_dev = new_decode_dev(journal_devnum);
5396 	} else
5397 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5398 
5399 	if (journal_inum && journal_dev) {
5400 		ext4_msg(sb, KERN_ERR,
5401 			 "filesystem has both journal inode and journal device!");
5402 		return -EINVAL;
5403 	}
5404 
5405 	if (journal_inum) {
5406 		journal = ext4_get_journal(sb, journal_inum);
5407 		if (!journal)
5408 			return -EINVAL;
5409 	} else {
5410 		journal = ext4_get_dev_journal(sb, journal_dev);
5411 		if (!journal)
5412 			return -EINVAL;
5413 	}
5414 
5415 	journal_dev_ro = bdev_read_only(journal->j_dev);
5416 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5417 
5418 	if (journal_dev_ro && !sb_rdonly(sb)) {
5419 		ext4_msg(sb, KERN_ERR,
5420 			 "journal device read-only, try mounting with '-o ro'");
5421 		err = -EROFS;
5422 		goto err_out;
5423 	}
5424 
5425 	/*
5426 	 * Are we loading a blank journal or performing recovery after a
5427 	 * crash?  For recovery, we need to check in advance whether we
5428 	 * can get read-write access to the device.
5429 	 */
5430 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5431 		if (sb_rdonly(sb)) {
5432 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5433 					"required on readonly filesystem");
5434 			if (really_read_only) {
5435 				ext4_msg(sb, KERN_ERR, "write access "
5436 					"unavailable, cannot proceed "
5437 					"(try mounting with noload)");
5438 				err = -EROFS;
5439 				goto err_out;
5440 			}
5441 			ext4_msg(sb, KERN_INFO, "write access will "
5442 			       "be enabled during recovery");
5443 		}
5444 	}
5445 
5446 	if (!(journal->j_flags & JBD2_BARRIER))
5447 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5448 
5449 	if (!ext4_has_feature_journal_needs_recovery(sb))
5450 		err = jbd2_journal_wipe(journal, !really_read_only);
5451 	if (!err) {
5452 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5453 		if (save)
5454 			memcpy(save, ((char *) es) +
5455 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5456 		err = jbd2_journal_load(journal);
5457 		if (save)
5458 			memcpy(((char *) es) + EXT4_S_ERR_START,
5459 			       save, EXT4_S_ERR_LEN);
5460 		kfree(save);
5461 	}
5462 
5463 	if (err) {
5464 		ext4_msg(sb, KERN_ERR, "error loading journal");
5465 		goto err_out;
5466 	}
5467 
5468 	EXT4_SB(sb)->s_journal = journal;
5469 	err = ext4_clear_journal_err(sb, es);
5470 	if (err) {
5471 		EXT4_SB(sb)->s_journal = NULL;
5472 		jbd2_journal_destroy(journal);
5473 		return err;
5474 	}
5475 
5476 	if (!really_read_only && journal_devnum &&
5477 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5478 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5479 
5480 		/* Make sure we flush the recovery flag to disk. */
5481 		ext4_commit_super(sb, 1);
5482 	}
5483 
5484 	return 0;
5485 
5486 err_out:
5487 	jbd2_journal_destroy(journal);
5488 	return err;
5489 }
5490 
5491 static int ext4_commit_super(struct super_block *sb, int sync)
5492 {
5493 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5494 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5495 	int error = 0;
5496 
5497 	if (!sbh || block_device_ejected(sb))
5498 		return error;
5499 
5500 	/*
5501 	 * If the file system is mounted read-only, don't update the
5502 	 * superblock write time.  This avoids updating the superblock
5503 	 * write time when we are mounting the root file system
5504 	 * read/only but we need to replay the journal; at that point,
5505 	 * for people who are east of GMT and who make their clock
5506 	 * tick in localtime for Windows bug-for-bug compatibility,
5507 	 * the clock is set in the future, and this will cause e2fsck
5508 	 * to complain and force a full file system check.
5509 	 */
5510 	if (!(sb->s_flags & SB_RDONLY))
5511 		ext4_update_tstamp(es, s_wtime);
5512 	if (sb->s_bdev->bd_part)
5513 		es->s_kbytes_written =
5514 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5515 			    ((part_stat_read(sb->s_bdev->bd_part,
5516 					     sectors[STAT_WRITE]) -
5517 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5518 	else
5519 		es->s_kbytes_written =
5520 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5521 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5522 		ext4_free_blocks_count_set(es,
5523 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5524 				&EXT4_SB(sb)->s_freeclusters_counter)));
5525 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5526 		es->s_free_inodes_count =
5527 			cpu_to_le32(percpu_counter_sum_positive(
5528 				&EXT4_SB(sb)->s_freeinodes_counter));
5529 	BUFFER_TRACE(sbh, "marking dirty");
5530 	ext4_superblock_csum_set(sb);
5531 	if (sync)
5532 		lock_buffer(sbh);
5533 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5534 		/*
5535 		 * Oh, dear.  A previous attempt to write the
5536 		 * superblock failed.  This could happen because the
5537 		 * USB device was yanked out.  Or it could happen to
5538 		 * be a transient write error and maybe the block will
5539 		 * be remapped.  Nothing we can do but to retry the
5540 		 * write and hope for the best.
5541 		 */
5542 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5543 		       "superblock detected");
5544 		clear_buffer_write_io_error(sbh);
5545 		set_buffer_uptodate(sbh);
5546 	}
5547 	mark_buffer_dirty(sbh);
5548 	if (sync) {
5549 		unlock_buffer(sbh);
5550 		error = __sync_dirty_buffer(sbh,
5551 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5552 		if (buffer_write_io_error(sbh)) {
5553 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5554 			       "superblock");
5555 			clear_buffer_write_io_error(sbh);
5556 			set_buffer_uptodate(sbh);
5557 		}
5558 	}
5559 	return error;
5560 }
5561 
5562 /*
5563  * Have we just finished recovery?  If so, and if we are mounting (or
5564  * remounting) the filesystem readonly, then we will end up with a
5565  * consistent fs on disk.  Record that fact.
5566  */
5567 static int ext4_mark_recovery_complete(struct super_block *sb,
5568 				       struct ext4_super_block *es)
5569 {
5570 	int err;
5571 	journal_t *journal = EXT4_SB(sb)->s_journal;
5572 
5573 	if (!ext4_has_feature_journal(sb)) {
5574 		if (journal != NULL) {
5575 			ext4_error(sb, "Journal got removed while the fs was "
5576 				   "mounted!");
5577 			return -EFSCORRUPTED;
5578 		}
5579 		return 0;
5580 	}
5581 	jbd2_journal_lock_updates(journal);
5582 	err = jbd2_journal_flush(journal);
5583 	if (err < 0)
5584 		goto out;
5585 
5586 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5587 		ext4_clear_feature_journal_needs_recovery(sb);
5588 		ext4_commit_super(sb, 1);
5589 	}
5590 out:
5591 	jbd2_journal_unlock_updates(journal);
5592 	return err;
5593 }
5594 
5595 /*
5596  * If we are mounting (or read-write remounting) a filesystem whose journal
5597  * has recorded an error from a previous lifetime, move that error to the
5598  * main filesystem now.
5599  */
5600 static int ext4_clear_journal_err(struct super_block *sb,
5601 				   struct ext4_super_block *es)
5602 {
5603 	journal_t *journal;
5604 	int j_errno;
5605 	const char *errstr;
5606 
5607 	if (!ext4_has_feature_journal(sb)) {
5608 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5609 		return -EFSCORRUPTED;
5610 	}
5611 
5612 	journal = EXT4_SB(sb)->s_journal;
5613 
5614 	/*
5615 	 * Now check for any error status which may have been recorded in the
5616 	 * journal by a prior ext4_error() or ext4_abort()
5617 	 */
5618 
5619 	j_errno = jbd2_journal_errno(journal);
5620 	if (j_errno) {
5621 		char nbuf[16];
5622 
5623 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5624 		ext4_warning(sb, "Filesystem error recorded "
5625 			     "from previous mount: %s", errstr);
5626 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5627 
5628 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5629 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5630 		ext4_commit_super(sb, 1);
5631 
5632 		jbd2_journal_clear_err(journal);
5633 		jbd2_journal_update_sb_errno(journal);
5634 	}
5635 	return 0;
5636 }
5637 
5638 /*
5639  * Force the running and committing transactions to commit,
5640  * and wait on the commit.
5641  */
5642 int ext4_force_commit(struct super_block *sb)
5643 {
5644 	journal_t *journal;
5645 
5646 	if (sb_rdonly(sb))
5647 		return 0;
5648 
5649 	journal = EXT4_SB(sb)->s_journal;
5650 	return ext4_journal_force_commit(journal);
5651 }
5652 
5653 static int ext4_sync_fs(struct super_block *sb, int wait)
5654 {
5655 	int ret = 0;
5656 	tid_t target;
5657 	bool needs_barrier = false;
5658 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5659 
5660 	if (unlikely(ext4_forced_shutdown(sbi)))
5661 		return 0;
5662 
5663 	trace_ext4_sync_fs(sb, wait);
5664 	flush_workqueue(sbi->rsv_conversion_wq);
5665 	/*
5666 	 * Writeback quota in non-journalled quota case - journalled quota has
5667 	 * no dirty dquots
5668 	 */
5669 	dquot_writeback_dquots(sb, -1);
5670 	/*
5671 	 * Data writeback is possible w/o journal transaction, so barrier must
5672 	 * being sent at the end of the function. But we can skip it if
5673 	 * transaction_commit will do it for us.
5674 	 */
5675 	if (sbi->s_journal) {
5676 		target = jbd2_get_latest_transaction(sbi->s_journal);
5677 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5678 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5679 			needs_barrier = true;
5680 
5681 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5682 			if (wait)
5683 				ret = jbd2_log_wait_commit(sbi->s_journal,
5684 							   target);
5685 		}
5686 	} else if (wait && test_opt(sb, BARRIER))
5687 		needs_barrier = true;
5688 	if (needs_barrier) {
5689 		int err;
5690 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL);
5691 		if (!ret)
5692 			ret = err;
5693 	}
5694 
5695 	return ret;
5696 }
5697 
5698 /*
5699  * LVM calls this function before a (read-only) snapshot is created.  This
5700  * gives us a chance to flush the journal completely and mark the fs clean.
5701  *
5702  * Note that only this function cannot bring a filesystem to be in a clean
5703  * state independently. It relies on upper layer to stop all data & metadata
5704  * modifications.
5705  */
5706 static int ext4_freeze(struct super_block *sb)
5707 {
5708 	int error = 0;
5709 	journal_t *journal;
5710 
5711 	if (sb_rdonly(sb))
5712 		return 0;
5713 
5714 	journal = EXT4_SB(sb)->s_journal;
5715 
5716 	if (journal) {
5717 		/* Now we set up the journal barrier. */
5718 		jbd2_journal_lock_updates(journal);
5719 
5720 		/*
5721 		 * Don't clear the needs_recovery flag if we failed to
5722 		 * flush the journal.
5723 		 */
5724 		error = jbd2_journal_flush(journal);
5725 		if (error < 0)
5726 			goto out;
5727 
5728 		/* Journal blocked and flushed, clear needs_recovery flag. */
5729 		ext4_clear_feature_journal_needs_recovery(sb);
5730 	}
5731 
5732 	error = ext4_commit_super(sb, 1);
5733 out:
5734 	if (journal)
5735 		/* we rely on upper layer to stop further updates */
5736 		jbd2_journal_unlock_updates(journal);
5737 	return error;
5738 }
5739 
5740 /*
5741  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5742  * flag here, even though the filesystem is not technically dirty yet.
5743  */
5744 static int ext4_unfreeze(struct super_block *sb)
5745 {
5746 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5747 		return 0;
5748 
5749 	if (EXT4_SB(sb)->s_journal) {
5750 		/* Reset the needs_recovery flag before the fs is unlocked. */
5751 		ext4_set_feature_journal_needs_recovery(sb);
5752 	}
5753 
5754 	ext4_commit_super(sb, 1);
5755 	return 0;
5756 }
5757 
5758 /*
5759  * Structure to save mount options for ext4_remount's benefit
5760  */
5761 struct ext4_mount_options {
5762 	unsigned long s_mount_opt;
5763 	unsigned long s_mount_opt2;
5764 	kuid_t s_resuid;
5765 	kgid_t s_resgid;
5766 	unsigned long s_commit_interval;
5767 	u32 s_min_batch_time, s_max_batch_time;
5768 #ifdef CONFIG_QUOTA
5769 	int s_jquota_fmt;
5770 	char *s_qf_names[EXT4_MAXQUOTAS];
5771 #endif
5772 };
5773 
5774 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5775 {
5776 	struct ext4_super_block *es;
5777 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5778 	unsigned long old_sb_flags, vfs_flags;
5779 	struct ext4_mount_options old_opts;
5780 	int enable_quota = 0;
5781 	ext4_group_t g;
5782 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5783 	int err = 0;
5784 #ifdef CONFIG_QUOTA
5785 	int i, j;
5786 	char *to_free[EXT4_MAXQUOTAS];
5787 #endif
5788 	char *orig_data = kstrdup(data, GFP_KERNEL);
5789 
5790 	if (data && !orig_data)
5791 		return -ENOMEM;
5792 
5793 	/* Store the original options */
5794 	old_sb_flags = sb->s_flags;
5795 	old_opts.s_mount_opt = sbi->s_mount_opt;
5796 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5797 	old_opts.s_resuid = sbi->s_resuid;
5798 	old_opts.s_resgid = sbi->s_resgid;
5799 	old_opts.s_commit_interval = sbi->s_commit_interval;
5800 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5801 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5802 #ifdef CONFIG_QUOTA
5803 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5804 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5805 		if (sbi->s_qf_names[i]) {
5806 			char *qf_name = get_qf_name(sb, sbi, i);
5807 
5808 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5809 			if (!old_opts.s_qf_names[i]) {
5810 				for (j = 0; j < i; j++)
5811 					kfree(old_opts.s_qf_names[j]);
5812 				kfree(orig_data);
5813 				return -ENOMEM;
5814 			}
5815 		} else
5816 			old_opts.s_qf_names[i] = NULL;
5817 #endif
5818 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5819 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5820 
5821 	/*
5822 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5823 	 * either way we need to make sure it matches in both *flags and
5824 	 * s_flags. Copy those selected flags from *flags to s_flags
5825 	 */
5826 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5827 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5828 
5829 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5830 		err = -EINVAL;
5831 		goto restore_opts;
5832 	}
5833 
5834 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5835 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5836 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5837 			 "during remount not supported; ignoring");
5838 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5839 	}
5840 
5841 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5842 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5843 			ext4_msg(sb, KERN_ERR, "can't mount with "
5844 				 "both data=journal and delalloc");
5845 			err = -EINVAL;
5846 			goto restore_opts;
5847 		}
5848 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5849 			ext4_msg(sb, KERN_ERR, "can't mount with "
5850 				 "both data=journal and dioread_nolock");
5851 			err = -EINVAL;
5852 			goto restore_opts;
5853 		}
5854 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5855 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5856 			ext4_msg(sb, KERN_ERR, "can't mount with "
5857 				"journal_async_commit in data=ordered mode");
5858 			err = -EINVAL;
5859 			goto restore_opts;
5860 		}
5861 	}
5862 
5863 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5864 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5865 		err = -EINVAL;
5866 		goto restore_opts;
5867 	}
5868 
5869 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5870 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5871 
5872 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5873 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5874 
5875 	es = sbi->s_es;
5876 
5877 	if (sbi->s_journal) {
5878 		ext4_init_journal_params(sb, sbi->s_journal);
5879 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5880 	}
5881 
5882 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5883 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
5884 			err = -EROFS;
5885 			goto restore_opts;
5886 		}
5887 
5888 		if (*flags & SB_RDONLY) {
5889 			err = sync_filesystem(sb);
5890 			if (err < 0)
5891 				goto restore_opts;
5892 			err = dquot_suspend(sb, -1);
5893 			if (err < 0)
5894 				goto restore_opts;
5895 
5896 			/*
5897 			 * First of all, the unconditional stuff we have to do
5898 			 * to disable replay of the journal when we next remount
5899 			 */
5900 			sb->s_flags |= SB_RDONLY;
5901 
5902 			/*
5903 			 * OK, test if we are remounting a valid rw partition
5904 			 * readonly, and if so set the rdonly flag and then
5905 			 * mark the partition as valid again.
5906 			 */
5907 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5908 			    (sbi->s_mount_state & EXT4_VALID_FS))
5909 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5910 
5911 			if (sbi->s_journal) {
5912 				/*
5913 				 * We let remount-ro finish even if marking fs
5914 				 * as clean failed...
5915 				 */
5916 				ext4_mark_recovery_complete(sb, es);
5917 			}
5918 			if (sbi->s_mmp_tsk)
5919 				kthread_stop(sbi->s_mmp_tsk);
5920 		} else {
5921 			/* Make sure we can mount this feature set readwrite */
5922 			if (ext4_has_feature_readonly(sb) ||
5923 			    !ext4_feature_set_ok(sb, 0)) {
5924 				err = -EROFS;
5925 				goto restore_opts;
5926 			}
5927 			/*
5928 			 * Make sure the group descriptor checksums
5929 			 * are sane.  If they aren't, refuse to remount r/w.
5930 			 */
5931 			for (g = 0; g < sbi->s_groups_count; g++) {
5932 				struct ext4_group_desc *gdp =
5933 					ext4_get_group_desc(sb, g, NULL);
5934 
5935 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5936 					ext4_msg(sb, KERN_ERR,
5937 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5938 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5939 					       le16_to_cpu(gdp->bg_checksum));
5940 					err = -EFSBADCRC;
5941 					goto restore_opts;
5942 				}
5943 			}
5944 
5945 			/*
5946 			 * If we have an unprocessed orphan list hanging
5947 			 * around from a previously readonly bdev mount,
5948 			 * require a full umount/remount for now.
5949 			 */
5950 			if (es->s_last_orphan) {
5951 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5952 				       "remount RDWR because of unprocessed "
5953 				       "orphan inode list.  Please "
5954 				       "umount/remount instead");
5955 				err = -EINVAL;
5956 				goto restore_opts;
5957 			}
5958 
5959 			/*
5960 			 * Mounting a RDONLY partition read-write, so reread
5961 			 * and store the current valid flag.  (It may have
5962 			 * been changed by e2fsck since we originally mounted
5963 			 * the partition.)
5964 			 */
5965 			if (sbi->s_journal) {
5966 				err = ext4_clear_journal_err(sb, es);
5967 				if (err)
5968 					goto restore_opts;
5969 			}
5970 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5971 
5972 			err = ext4_setup_super(sb, es, 0);
5973 			if (err)
5974 				goto restore_opts;
5975 
5976 			sb->s_flags &= ~SB_RDONLY;
5977 			if (ext4_has_feature_mmp(sb))
5978 				if (ext4_multi_mount_protect(sb,
5979 						le64_to_cpu(es->s_mmp_block))) {
5980 					err = -EROFS;
5981 					goto restore_opts;
5982 				}
5983 			enable_quota = 1;
5984 		}
5985 	}
5986 
5987 	/*
5988 	 * Reinitialize lazy itable initialization thread based on
5989 	 * current settings
5990 	 */
5991 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5992 		ext4_unregister_li_request(sb);
5993 	else {
5994 		ext4_group_t first_not_zeroed;
5995 		first_not_zeroed = ext4_has_uninit_itable(sb);
5996 		ext4_register_li_request(sb, first_not_zeroed);
5997 	}
5998 
5999 	/*
6000 	 * Handle creation of system zone data early because it can fail.
6001 	 * Releasing of existing data is done when we are sure remount will
6002 	 * succeed.
6003 	 */
6004 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6005 		err = ext4_setup_system_zone(sb);
6006 		if (err)
6007 			goto restore_opts;
6008 	}
6009 
6010 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6011 		err = ext4_commit_super(sb, 1);
6012 		if (err)
6013 			goto restore_opts;
6014 	}
6015 
6016 #ifdef CONFIG_QUOTA
6017 	/* Release old quota file names */
6018 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6019 		kfree(old_opts.s_qf_names[i]);
6020 	if (enable_quota) {
6021 		if (sb_any_quota_suspended(sb))
6022 			dquot_resume(sb, -1);
6023 		else if (ext4_has_feature_quota(sb)) {
6024 			err = ext4_enable_quotas(sb);
6025 			if (err)
6026 				goto restore_opts;
6027 		}
6028 	}
6029 #endif
6030 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6031 		ext4_release_system_zone(sb);
6032 
6033 	/*
6034 	 * Some options can be enabled by ext4 and/or by VFS mount flag
6035 	 * either way we need to make sure it matches in both *flags and
6036 	 * s_flags. Copy those selected flags from s_flags to *flags
6037 	 */
6038 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6039 
6040 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
6041 	kfree(orig_data);
6042 	return 0;
6043 
6044 restore_opts:
6045 	sb->s_flags = old_sb_flags;
6046 	sbi->s_mount_opt = old_opts.s_mount_opt;
6047 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6048 	sbi->s_resuid = old_opts.s_resuid;
6049 	sbi->s_resgid = old_opts.s_resgid;
6050 	sbi->s_commit_interval = old_opts.s_commit_interval;
6051 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6052 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6053 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6054 		ext4_release_system_zone(sb);
6055 #ifdef CONFIG_QUOTA
6056 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6057 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6058 		to_free[i] = get_qf_name(sb, sbi, i);
6059 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6060 	}
6061 	synchronize_rcu();
6062 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6063 		kfree(to_free[i]);
6064 #endif
6065 	kfree(orig_data);
6066 	return err;
6067 }
6068 
6069 #ifdef CONFIG_QUOTA
6070 static int ext4_statfs_project(struct super_block *sb,
6071 			       kprojid_t projid, struct kstatfs *buf)
6072 {
6073 	struct kqid qid;
6074 	struct dquot *dquot;
6075 	u64 limit;
6076 	u64 curblock;
6077 
6078 	qid = make_kqid_projid(projid);
6079 	dquot = dqget(sb, qid);
6080 	if (IS_ERR(dquot))
6081 		return PTR_ERR(dquot);
6082 	spin_lock(&dquot->dq_dqb_lock);
6083 
6084 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6085 			     dquot->dq_dqb.dqb_bhardlimit);
6086 	limit >>= sb->s_blocksize_bits;
6087 
6088 	if (limit && buf->f_blocks > limit) {
6089 		curblock = (dquot->dq_dqb.dqb_curspace +
6090 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6091 		buf->f_blocks = limit;
6092 		buf->f_bfree = buf->f_bavail =
6093 			(buf->f_blocks > curblock) ?
6094 			 (buf->f_blocks - curblock) : 0;
6095 	}
6096 
6097 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6098 			     dquot->dq_dqb.dqb_ihardlimit);
6099 	if (limit && buf->f_files > limit) {
6100 		buf->f_files = limit;
6101 		buf->f_ffree =
6102 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6103 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6104 	}
6105 
6106 	spin_unlock(&dquot->dq_dqb_lock);
6107 	dqput(dquot);
6108 	return 0;
6109 }
6110 #endif
6111 
6112 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6113 {
6114 	struct super_block *sb = dentry->d_sb;
6115 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6116 	struct ext4_super_block *es = sbi->s_es;
6117 	ext4_fsblk_t overhead = 0, resv_blocks;
6118 	u64 fsid;
6119 	s64 bfree;
6120 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6121 
6122 	if (!test_opt(sb, MINIX_DF))
6123 		overhead = sbi->s_overhead;
6124 
6125 	buf->f_type = EXT4_SUPER_MAGIC;
6126 	buf->f_bsize = sb->s_blocksize;
6127 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6128 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6129 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6130 	/* prevent underflow in case that few free space is available */
6131 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6132 	buf->f_bavail = buf->f_bfree -
6133 			(ext4_r_blocks_count(es) + resv_blocks);
6134 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6135 		buf->f_bavail = 0;
6136 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6137 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6138 	buf->f_namelen = EXT4_NAME_LEN;
6139 	fsid = le64_to_cpup((void *)es->s_uuid) ^
6140 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
6141 	buf->f_fsid = u64_to_fsid(fsid);
6142 
6143 #ifdef CONFIG_QUOTA
6144 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6145 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6146 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6147 #endif
6148 	return 0;
6149 }
6150 
6151 
6152 #ifdef CONFIG_QUOTA
6153 
6154 /*
6155  * Helper functions so that transaction is started before we acquire dqio_sem
6156  * to keep correct lock ordering of transaction > dqio_sem
6157  */
6158 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6159 {
6160 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6161 }
6162 
6163 static int ext4_write_dquot(struct dquot *dquot)
6164 {
6165 	int ret, err;
6166 	handle_t *handle;
6167 	struct inode *inode;
6168 
6169 	inode = dquot_to_inode(dquot);
6170 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6171 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6172 	if (IS_ERR(handle))
6173 		return PTR_ERR(handle);
6174 	ret = dquot_commit(dquot);
6175 	err = ext4_journal_stop(handle);
6176 	if (!ret)
6177 		ret = err;
6178 	return ret;
6179 }
6180 
6181 static int ext4_acquire_dquot(struct dquot *dquot)
6182 {
6183 	int ret, err;
6184 	handle_t *handle;
6185 
6186 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6187 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6188 	if (IS_ERR(handle))
6189 		return PTR_ERR(handle);
6190 	ret = dquot_acquire(dquot);
6191 	err = ext4_journal_stop(handle);
6192 	if (!ret)
6193 		ret = err;
6194 	return ret;
6195 }
6196 
6197 static int ext4_release_dquot(struct dquot *dquot)
6198 {
6199 	int ret, err;
6200 	handle_t *handle;
6201 
6202 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6203 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6204 	if (IS_ERR(handle)) {
6205 		/* Release dquot anyway to avoid endless cycle in dqput() */
6206 		dquot_release(dquot);
6207 		return PTR_ERR(handle);
6208 	}
6209 	ret = dquot_release(dquot);
6210 	err = ext4_journal_stop(handle);
6211 	if (!ret)
6212 		ret = err;
6213 	return ret;
6214 }
6215 
6216 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6217 {
6218 	struct super_block *sb = dquot->dq_sb;
6219 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6220 
6221 	/* Are we journaling quotas? */
6222 	if (ext4_has_feature_quota(sb) ||
6223 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
6224 		dquot_mark_dquot_dirty(dquot);
6225 		return ext4_write_dquot(dquot);
6226 	} else {
6227 		return dquot_mark_dquot_dirty(dquot);
6228 	}
6229 }
6230 
6231 static int ext4_write_info(struct super_block *sb, int type)
6232 {
6233 	int ret, err;
6234 	handle_t *handle;
6235 
6236 	/* Data block + inode block */
6237 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6238 	if (IS_ERR(handle))
6239 		return PTR_ERR(handle);
6240 	ret = dquot_commit_info(sb, type);
6241 	err = ext4_journal_stop(handle);
6242 	if (!ret)
6243 		ret = err;
6244 	return ret;
6245 }
6246 
6247 /*
6248  * Turn on quotas during mount time - we need to find
6249  * the quota file and such...
6250  */
6251 static int ext4_quota_on_mount(struct super_block *sb, int type)
6252 {
6253 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6254 					EXT4_SB(sb)->s_jquota_fmt, type);
6255 }
6256 
6257 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6258 {
6259 	struct ext4_inode_info *ei = EXT4_I(inode);
6260 
6261 	/* The first argument of lockdep_set_subclass has to be
6262 	 * *exactly* the same as the argument to init_rwsem() --- in
6263 	 * this case, in init_once() --- or lockdep gets unhappy
6264 	 * because the name of the lock is set using the
6265 	 * stringification of the argument to init_rwsem().
6266 	 */
6267 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6268 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6269 }
6270 
6271 /*
6272  * Standard function to be called on quota_on
6273  */
6274 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6275 			 const struct path *path)
6276 {
6277 	int err;
6278 
6279 	if (!test_opt(sb, QUOTA))
6280 		return -EINVAL;
6281 
6282 	/* Quotafile not on the same filesystem? */
6283 	if (path->dentry->d_sb != sb)
6284 		return -EXDEV;
6285 
6286 	/* Quota already enabled for this file? */
6287 	if (IS_NOQUOTA(d_inode(path->dentry)))
6288 		return -EBUSY;
6289 
6290 	/* Journaling quota? */
6291 	if (EXT4_SB(sb)->s_qf_names[type]) {
6292 		/* Quotafile not in fs root? */
6293 		if (path->dentry->d_parent != sb->s_root)
6294 			ext4_msg(sb, KERN_WARNING,
6295 				"Quota file not on filesystem root. "
6296 				"Journaled quota will not work");
6297 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6298 	} else {
6299 		/*
6300 		 * Clear the flag just in case mount options changed since
6301 		 * last time.
6302 		 */
6303 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6304 	}
6305 
6306 	/*
6307 	 * When we journal data on quota file, we have to flush journal to see
6308 	 * all updates to the file when we bypass pagecache...
6309 	 */
6310 	if (EXT4_SB(sb)->s_journal &&
6311 	    ext4_should_journal_data(d_inode(path->dentry))) {
6312 		/*
6313 		 * We don't need to lock updates but journal_flush() could
6314 		 * otherwise be livelocked...
6315 		 */
6316 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6317 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
6318 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6319 		if (err)
6320 			return err;
6321 	}
6322 
6323 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6324 	err = dquot_quota_on(sb, type, format_id, path);
6325 	if (err) {
6326 		lockdep_set_quota_inode(path->dentry->d_inode,
6327 					     I_DATA_SEM_NORMAL);
6328 	} else {
6329 		struct inode *inode = d_inode(path->dentry);
6330 		handle_t *handle;
6331 
6332 		/*
6333 		 * Set inode flags to prevent userspace from messing with quota
6334 		 * files. If this fails, we return success anyway since quotas
6335 		 * are already enabled and this is not a hard failure.
6336 		 */
6337 		inode_lock(inode);
6338 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6339 		if (IS_ERR(handle))
6340 			goto unlock_inode;
6341 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6342 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6343 				S_NOATIME | S_IMMUTABLE);
6344 		err = ext4_mark_inode_dirty(handle, inode);
6345 		ext4_journal_stop(handle);
6346 	unlock_inode:
6347 		inode_unlock(inode);
6348 	}
6349 	return err;
6350 }
6351 
6352 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6353 			     unsigned int flags)
6354 {
6355 	int err;
6356 	struct inode *qf_inode;
6357 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6358 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6359 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6360 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6361 	};
6362 
6363 	BUG_ON(!ext4_has_feature_quota(sb));
6364 
6365 	if (!qf_inums[type])
6366 		return -EPERM;
6367 
6368 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6369 	if (IS_ERR(qf_inode)) {
6370 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6371 		return PTR_ERR(qf_inode);
6372 	}
6373 
6374 	/* Don't account quota for quota files to avoid recursion */
6375 	qf_inode->i_flags |= S_NOQUOTA;
6376 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6377 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6378 	if (err)
6379 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6380 	iput(qf_inode);
6381 
6382 	return err;
6383 }
6384 
6385 /* Enable usage tracking for all quota types. */
6386 static int ext4_enable_quotas(struct super_block *sb)
6387 {
6388 	int type, err = 0;
6389 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6390 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6391 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6392 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6393 	};
6394 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6395 		test_opt(sb, USRQUOTA),
6396 		test_opt(sb, GRPQUOTA),
6397 		test_opt(sb, PRJQUOTA),
6398 	};
6399 
6400 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6401 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6402 		if (qf_inums[type]) {
6403 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6404 				DQUOT_USAGE_ENABLED |
6405 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6406 			if (err) {
6407 				ext4_warning(sb,
6408 					"Failed to enable quota tracking "
6409 					"(type=%d, err=%d). Please run "
6410 					"e2fsck to fix.", type, err);
6411 				for (type--; type >= 0; type--)
6412 					dquot_quota_off(sb, type);
6413 
6414 				return err;
6415 			}
6416 		}
6417 	}
6418 	return 0;
6419 }
6420 
6421 static int ext4_quota_off(struct super_block *sb, int type)
6422 {
6423 	struct inode *inode = sb_dqopt(sb)->files[type];
6424 	handle_t *handle;
6425 	int err;
6426 
6427 	/* Force all delayed allocation blocks to be allocated.
6428 	 * Caller already holds s_umount sem */
6429 	if (test_opt(sb, DELALLOC))
6430 		sync_filesystem(sb);
6431 
6432 	if (!inode || !igrab(inode))
6433 		goto out;
6434 
6435 	err = dquot_quota_off(sb, type);
6436 	if (err || ext4_has_feature_quota(sb))
6437 		goto out_put;
6438 
6439 	inode_lock(inode);
6440 	/*
6441 	 * Update modification times of quota files when userspace can
6442 	 * start looking at them. If we fail, we return success anyway since
6443 	 * this is not a hard failure and quotas are already disabled.
6444 	 */
6445 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6446 	if (IS_ERR(handle)) {
6447 		err = PTR_ERR(handle);
6448 		goto out_unlock;
6449 	}
6450 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6451 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6452 	inode->i_mtime = inode->i_ctime = current_time(inode);
6453 	err = ext4_mark_inode_dirty(handle, inode);
6454 	ext4_journal_stop(handle);
6455 out_unlock:
6456 	inode_unlock(inode);
6457 out_put:
6458 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6459 	iput(inode);
6460 	return err;
6461 out:
6462 	return dquot_quota_off(sb, type);
6463 }
6464 
6465 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6466  * acquiring the locks... As quota files are never truncated and quota code
6467  * itself serializes the operations (and no one else should touch the files)
6468  * we don't have to be afraid of races */
6469 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6470 			       size_t len, loff_t off)
6471 {
6472 	struct inode *inode = sb_dqopt(sb)->files[type];
6473 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6474 	int offset = off & (sb->s_blocksize - 1);
6475 	int tocopy;
6476 	size_t toread;
6477 	struct buffer_head *bh;
6478 	loff_t i_size = i_size_read(inode);
6479 
6480 	if (off > i_size)
6481 		return 0;
6482 	if (off+len > i_size)
6483 		len = i_size-off;
6484 	toread = len;
6485 	while (toread > 0) {
6486 		tocopy = sb->s_blocksize - offset < toread ?
6487 				sb->s_blocksize - offset : toread;
6488 		bh = ext4_bread(NULL, inode, blk, 0);
6489 		if (IS_ERR(bh))
6490 			return PTR_ERR(bh);
6491 		if (!bh)	/* A hole? */
6492 			memset(data, 0, tocopy);
6493 		else
6494 			memcpy(data, bh->b_data+offset, tocopy);
6495 		brelse(bh);
6496 		offset = 0;
6497 		toread -= tocopy;
6498 		data += tocopy;
6499 		blk++;
6500 	}
6501 	return len;
6502 }
6503 
6504 /* Write to quotafile (we know the transaction is already started and has
6505  * enough credits) */
6506 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6507 				const char *data, size_t len, loff_t off)
6508 {
6509 	struct inode *inode = sb_dqopt(sb)->files[type];
6510 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6511 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6512 	int retries = 0;
6513 	struct buffer_head *bh;
6514 	handle_t *handle = journal_current_handle();
6515 
6516 	if (EXT4_SB(sb)->s_journal && !handle) {
6517 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6518 			" cancelled because transaction is not started",
6519 			(unsigned long long)off, (unsigned long long)len);
6520 		return -EIO;
6521 	}
6522 	/*
6523 	 * Since we account only one data block in transaction credits,
6524 	 * then it is impossible to cross a block boundary.
6525 	 */
6526 	if (sb->s_blocksize - offset < len) {
6527 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6528 			" cancelled because not block aligned",
6529 			(unsigned long long)off, (unsigned long long)len);
6530 		return -EIO;
6531 	}
6532 
6533 	do {
6534 		bh = ext4_bread(handle, inode, blk,
6535 				EXT4_GET_BLOCKS_CREATE |
6536 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6537 	} while (PTR_ERR(bh) == -ENOSPC &&
6538 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6539 	if (IS_ERR(bh))
6540 		return PTR_ERR(bh);
6541 	if (!bh)
6542 		goto out;
6543 	BUFFER_TRACE(bh, "get write access");
6544 	err = ext4_journal_get_write_access(handle, bh);
6545 	if (err) {
6546 		brelse(bh);
6547 		return err;
6548 	}
6549 	lock_buffer(bh);
6550 	memcpy(bh->b_data+offset, data, len);
6551 	flush_dcache_page(bh->b_page);
6552 	unlock_buffer(bh);
6553 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6554 	brelse(bh);
6555 out:
6556 	if (inode->i_size < off + len) {
6557 		i_size_write(inode, off + len);
6558 		EXT4_I(inode)->i_disksize = inode->i_size;
6559 		err2 = ext4_mark_inode_dirty(handle, inode);
6560 		if (unlikely(err2 && !err))
6561 			err = err2;
6562 	}
6563 	return err ? err : len;
6564 }
6565 #endif
6566 
6567 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6568 		       const char *dev_name, void *data)
6569 {
6570 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6571 }
6572 
6573 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6574 static inline void register_as_ext2(void)
6575 {
6576 	int err = register_filesystem(&ext2_fs_type);
6577 	if (err)
6578 		printk(KERN_WARNING
6579 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6580 }
6581 
6582 static inline void unregister_as_ext2(void)
6583 {
6584 	unregister_filesystem(&ext2_fs_type);
6585 }
6586 
6587 static inline int ext2_feature_set_ok(struct super_block *sb)
6588 {
6589 	if (ext4_has_unknown_ext2_incompat_features(sb))
6590 		return 0;
6591 	if (sb_rdonly(sb))
6592 		return 1;
6593 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6594 		return 0;
6595 	return 1;
6596 }
6597 #else
6598 static inline void register_as_ext2(void) { }
6599 static inline void unregister_as_ext2(void) { }
6600 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6601 #endif
6602 
6603 static inline void register_as_ext3(void)
6604 {
6605 	int err = register_filesystem(&ext3_fs_type);
6606 	if (err)
6607 		printk(KERN_WARNING
6608 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6609 }
6610 
6611 static inline void unregister_as_ext3(void)
6612 {
6613 	unregister_filesystem(&ext3_fs_type);
6614 }
6615 
6616 static inline int ext3_feature_set_ok(struct super_block *sb)
6617 {
6618 	if (ext4_has_unknown_ext3_incompat_features(sb))
6619 		return 0;
6620 	if (!ext4_has_feature_journal(sb))
6621 		return 0;
6622 	if (sb_rdonly(sb))
6623 		return 1;
6624 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6625 		return 0;
6626 	return 1;
6627 }
6628 
6629 static struct file_system_type ext4_fs_type = {
6630 	.owner		= THIS_MODULE,
6631 	.name		= "ext4",
6632 	.mount		= ext4_mount,
6633 	.kill_sb	= kill_block_super,
6634 	.fs_flags	= FS_REQUIRES_DEV,
6635 };
6636 MODULE_ALIAS_FS("ext4");
6637 
6638 /* Shared across all ext4 file systems */
6639 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6640 
6641 static int __init ext4_init_fs(void)
6642 {
6643 	int i, err;
6644 
6645 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6646 	ext4_li_info = NULL;
6647 	mutex_init(&ext4_li_mtx);
6648 
6649 	/* Build-time check for flags consistency */
6650 	ext4_check_flag_values();
6651 
6652 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6653 		init_waitqueue_head(&ext4__ioend_wq[i]);
6654 
6655 	err = ext4_init_es();
6656 	if (err)
6657 		return err;
6658 
6659 	err = ext4_init_pending();
6660 	if (err)
6661 		goto out7;
6662 
6663 	err = ext4_init_post_read_processing();
6664 	if (err)
6665 		goto out6;
6666 
6667 	err = ext4_init_pageio();
6668 	if (err)
6669 		goto out5;
6670 
6671 	err = ext4_init_system_zone();
6672 	if (err)
6673 		goto out4;
6674 
6675 	err = ext4_init_sysfs();
6676 	if (err)
6677 		goto out3;
6678 
6679 	err = ext4_init_mballoc();
6680 	if (err)
6681 		goto out2;
6682 	err = init_inodecache();
6683 	if (err)
6684 		goto out1;
6685 
6686 	err = ext4_fc_init_dentry_cache();
6687 	if (err)
6688 		goto out05;
6689 
6690 	register_as_ext3();
6691 	register_as_ext2();
6692 	err = register_filesystem(&ext4_fs_type);
6693 	if (err)
6694 		goto out;
6695 
6696 	return 0;
6697 out:
6698 	unregister_as_ext2();
6699 	unregister_as_ext3();
6700 out05:
6701 	destroy_inodecache();
6702 out1:
6703 	ext4_exit_mballoc();
6704 out2:
6705 	ext4_exit_sysfs();
6706 out3:
6707 	ext4_exit_system_zone();
6708 out4:
6709 	ext4_exit_pageio();
6710 out5:
6711 	ext4_exit_post_read_processing();
6712 out6:
6713 	ext4_exit_pending();
6714 out7:
6715 	ext4_exit_es();
6716 
6717 	return err;
6718 }
6719 
6720 static void __exit ext4_exit_fs(void)
6721 {
6722 	ext4_destroy_lazyinit_thread();
6723 	unregister_as_ext2();
6724 	unregister_as_ext3();
6725 	unregister_filesystem(&ext4_fs_type);
6726 	destroy_inodecache();
6727 	ext4_exit_mballoc();
6728 	ext4_exit_sysfs();
6729 	ext4_exit_system_zone();
6730 	ext4_exit_pageio();
6731 	ext4_exit_post_read_processing();
6732 	ext4_exit_es();
6733 	ext4_exit_pending();
6734 }
6735 
6736 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6737 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6738 MODULE_LICENSE("GPL");
6739 MODULE_SOFTDEP("pre: crc32c");
6740 module_init(ext4_init_fs)
6741 module_exit(ext4_exit_fs)
6742