xref: /openbmc/linux/fs/ext4/super.c (revision e15a5365)
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 	ext4_show_quota_options(seq, sb);
2642 	return 0;
2643 }
2644 
2645 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2646 {
2647 	return _ext4_show_options(seq, root->d_sb, 0);
2648 }
2649 
2650 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2651 {
2652 	struct super_block *sb = seq->private;
2653 	int rc;
2654 
2655 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2656 	rc = _ext4_show_options(seq, sb, 1);
2657 	seq_puts(seq, "\n");
2658 	return rc;
2659 }
2660 
2661 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2662 			    int read_only)
2663 {
2664 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2665 	int err = 0;
2666 
2667 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2668 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2669 			 "forcing read-only mode");
2670 		err = -EROFS;
2671 		goto done;
2672 	}
2673 	if (read_only)
2674 		goto done;
2675 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2676 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2677 			 "running e2fsck is recommended");
2678 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2679 		ext4_msg(sb, KERN_WARNING,
2680 			 "warning: mounting fs with errors, "
2681 			 "running e2fsck is recommended");
2682 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2683 		 le16_to_cpu(es->s_mnt_count) >=
2684 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2685 		ext4_msg(sb, KERN_WARNING,
2686 			 "warning: maximal mount count reached, "
2687 			 "running e2fsck is recommended");
2688 	else if (le32_to_cpu(es->s_checkinterval) &&
2689 		 (ext4_get_tstamp(es, s_lastcheck) +
2690 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2691 		ext4_msg(sb, KERN_WARNING,
2692 			 "warning: checktime reached, "
2693 			 "running e2fsck is recommended");
2694 	if (!sbi->s_journal)
2695 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2696 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2697 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2698 	le16_add_cpu(&es->s_mnt_count, 1);
2699 	ext4_update_tstamp(es, s_mtime);
2700 	if (sbi->s_journal)
2701 		ext4_set_feature_journal_needs_recovery(sb);
2702 
2703 	err = ext4_commit_super(sb, 1);
2704 done:
2705 	if (test_opt(sb, DEBUG))
2706 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2707 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2708 			sb->s_blocksize,
2709 			sbi->s_groups_count,
2710 			EXT4_BLOCKS_PER_GROUP(sb),
2711 			EXT4_INODES_PER_GROUP(sb),
2712 			sbi->s_mount_opt, sbi->s_mount_opt2);
2713 
2714 	cleancache_init_fs(sb);
2715 	return err;
2716 }
2717 
2718 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2719 {
2720 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2721 	struct flex_groups **old_groups, **new_groups;
2722 	int size, i, j;
2723 
2724 	if (!sbi->s_log_groups_per_flex)
2725 		return 0;
2726 
2727 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2728 	if (size <= sbi->s_flex_groups_allocated)
2729 		return 0;
2730 
2731 	new_groups = kvzalloc(roundup_pow_of_two(size *
2732 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2733 	if (!new_groups) {
2734 		ext4_msg(sb, KERN_ERR,
2735 			 "not enough memory for %d flex group pointers", size);
2736 		return -ENOMEM;
2737 	}
2738 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2739 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2740 					 sizeof(struct flex_groups)),
2741 					 GFP_KERNEL);
2742 		if (!new_groups[i]) {
2743 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2744 				kvfree(new_groups[j]);
2745 			kvfree(new_groups);
2746 			ext4_msg(sb, KERN_ERR,
2747 				 "not enough memory for %d flex groups", size);
2748 			return -ENOMEM;
2749 		}
2750 	}
2751 	rcu_read_lock();
2752 	old_groups = rcu_dereference(sbi->s_flex_groups);
2753 	if (old_groups)
2754 		memcpy(new_groups, old_groups,
2755 		       (sbi->s_flex_groups_allocated *
2756 			sizeof(struct flex_groups *)));
2757 	rcu_read_unlock();
2758 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2759 	sbi->s_flex_groups_allocated = size;
2760 	if (old_groups)
2761 		ext4_kvfree_array_rcu(old_groups);
2762 	return 0;
2763 }
2764 
2765 static int ext4_fill_flex_info(struct super_block *sb)
2766 {
2767 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2768 	struct ext4_group_desc *gdp = NULL;
2769 	struct flex_groups *fg;
2770 	ext4_group_t flex_group;
2771 	int i, err;
2772 
2773 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2774 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2775 		sbi->s_log_groups_per_flex = 0;
2776 		return 1;
2777 	}
2778 
2779 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2780 	if (err)
2781 		goto failed;
2782 
2783 	for (i = 0; i < sbi->s_groups_count; i++) {
2784 		gdp = ext4_get_group_desc(sb, i, NULL);
2785 
2786 		flex_group = ext4_flex_group(sbi, i);
2787 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2788 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2789 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2790 			     &fg->free_clusters);
2791 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2792 	}
2793 
2794 	return 1;
2795 failed:
2796 	return 0;
2797 }
2798 
2799 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2800 				   struct ext4_group_desc *gdp)
2801 {
2802 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2803 	__u16 crc = 0;
2804 	__le32 le_group = cpu_to_le32(block_group);
2805 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2806 
2807 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2808 		/* Use new metadata_csum algorithm */
2809 		__u32 csum32;
2810 		__u16 dummy_csum = 0;
2811 
2812 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2813 				     sizeof(le_group));
2814 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2815 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2816 				     sizeof(dummy_csum));
2817 		offset += sizeof(dummy_csum);
2818 		if (offset < sbi->s_desc_size)
2819 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2820 					     sbi->s_desc_size - offset);
2821 
2822 		crc = csum32 & 0xFFFF;
2823 		goto out;
2824 	}
2825 
2826 	/* old crc16 code */
2827 	if (!ext4_has_feature_gdt_csum(sb))
2828 		return 0;
2829 
2830 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2831 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2832 	crc = crc16(crc, (__u8 *)gdp, offset);
2833 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2834 	/* for checksum of struct ext4_group_desc do the rest...*/
2835 	if (ext4_has_feature_64bit(sb) &&
2836 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2837 		crc = crc16(crc, (__u8 *)gdp + offset,
2838 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2839 				offset);
2840 
2841 out:
2842 	return cpu_to_le16(crc);
2843 }
2844 
2845 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2846 				struct ext4_group_desc *gdp)
2847 {
2848 	if (ext4_has_group_desc_csum(sb) &&
2849 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2850 		return 0;
2851 
2852 	return 1;
2853 }
2854 
2855 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2856 			      struct ext4_group_desc *gdp)
2857 {
2858 	if (!ext4_has_group_desc_csum(sb))
2859 		return;
2860 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2861 }
2862 
2863 /* Called at mount-time, super-block is locked */
2864 static int ext4_check_descriptors(struct super_block *sb,
2865 				  ext4_fsblk_t sb_block,
2866 				  ext4_group_t *first_not_zeroed)
2867 {
2868 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2869 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2870 	ext4_fsblk_t last_block;
2871 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2872 	ext4_fsblk_t block_bitmap;
2873 	ext4_fsblk_t inode_bitmap;
2874 	ext4_fsblk_t inode_table;
2875 	int flexbg_flag = 0;
2876 	ext4_group_t i, grp = sbi->s_groups_count;
2877 
2878 	if (ext4_has_feature_flex_bg(sb))
2879 		flexbg_flag = 1;
2880 
2881 	ext4_debug("Checking group descriptors");
2882 
2883 	for (i = 0; i < sbi->s_groups_count; i++) {
2884 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2885 
2886 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2887 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2888 		else
2889 			last_block = first_block +
2890 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2891 
2892 		if ((grp == sbi->s_groups_count) &&
2893 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2894 			grp = i;
2895 
2896 		block_bitmap = ext4_block_bitmap(sb, gdp);
2897 		if (block_bitmap == sb_block) {
2898 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2899 				 "Block bitmap for group %u overlaps "
2900 				 "superblock", i);
2901 			if (!sb_rdonly(sb))
2902 				return 0;
2903 		}
2904 		if (block_bitmap >= sb_block + 1 &&
2905 		    block_bitmap <= last_bg_block) {
2906 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2907 				 "Block bitmap for group %u overlaps "
2908 				 "block group descriptors", i);
2909 			if (!sb_rdonly(sb))
2910 				return 0;
2911 		}
2912 		if (block_bitmap < first_block || block_bitmap > last_block) {
2913 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2914 			       "Block bitmap for group %u not in group "
2915 			       "(block %llu)!", i, block_bitmap);
2916 			return 0;
2917 		}
2918 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2919 		if (inode_bitmap == sb_block) {
2920 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2921 				 "Inode bitmap for group %u overlaps "
2922 				 "superblock", i);
2923 			if (!sb_rdonly(sb))
2924 				return 0;
2925 		}
2926 		if (inode_bitmap >= sb_block + 1 &&
2927 		    inode_bitmap <= last_bg_block) {
2928 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2929 				 "Inode bitmap for group %u overlaps "
2930 				 "block group descriptors", i);
2931 			if (!sb_rdonly(sb))
2932 				return 0;
2933 		}
2934 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2935 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2936 			       "Inode bitmap for group %u not in group "
2937 			       "(block %llu)!", i, inode_bitmap);
2938 			return 0;
2939 		}
2940 		inode_table = ext4_inode_table(sb, gdp);
2941 		if (inode_table == sb_block) {
2942 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2943 				 "Inode table for group %u overlaps "
2944 				 "superblock", i);
2945 			if (!sb_rdonly(sb))
2946 				return 0;
2947 		}
2948 		if (inode_table >= sb_block + 1 &&
2949 		    inode_table <= last_bg_block) {
2950 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2951 				 "Inode table for group %u overlaps "
2952 				 "block group descriptors", i);
2953 			if (!sb_rdonly(sb))
2954 				return 0;
2955 		}
2956 		if (inode_table < first_block ||
2957 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2958 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2959 			       "Inode table for group %u not in group "
2960 			       "(block %llu)!", i, inode_table);
2961 			return 0;
2962 		}
2963 		ext4_lock_group(sb, i);
2964 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2965 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2966 				 "Checksum for group %u failed (%u!=%u)",
2967 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2968 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2969 			if (!sb_rdonly(sb)) {
2970 				ext4_unlock_group(sb, i);
2971 				return 0;
2972 			}
2973 		}
2974 		ext4_unlock_group(sb, i);
2975 		if (!flexbg_flag)
2976 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2977 	}
2978 	if (NULL != first_not_zeroed)
2979 		*first_not_zeroed = grp;
2980 	return 1;
2981 }
2982 
2983 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2984  * the superblock) which were deleted from all directories, but held open by
2985  * a process at the time of a crash.  We walk the list and try to delete these
2986  * inodes at recovery time (only with a read-write filesystem).
2987  *
2988  * In order to keep the orphan inode chain consistent during traversal (in
2989  * case of crash during recovery), we link each inode into the superblock
2990  * orphan list_head and handle it the same way as an inode deletion during
2991  * normal operation (which journals the operations for us).
2992  *
2993  * We only do an iget() and an iput() on each inode, which is very safe if we
2994  * accidentally point at an in-use or already deleted inode.  The worst that
2995  * can happen in this case is that we get a "bit already cleared" message from
2996  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2997  * e2fsck was run on this filesystem, and it must have already done the orphan
2998  * inode cleanup for us, so we can safely abort without any further action.
2999  */
3000 static void ext4_orphan_cleanup(struct super_block *sb,
3001 				struct ext4_super_block *es)
3002 {
3003 	unsigned int s_flags = sb->s_flags;
3004 	int ret, nr_orphans = 0, nr_truncates = 0;
3005 #ifdef CONFIG_QUOTA
3006 	int quota_update = 0;
3007 	int i;
3008 #endif
3009 	if (!es->s_last_orphan) {
3010 		jbd_debug(4, "no orphan inodes to clean up\n");
3011 		return;
3012 	}
3013 
3014 	if (bdev_read_only(sb->s_bdev)) {
3015 		ext4_msg(sb, KERN_ERR, "write access "
3016 			"unavailable, skipping orphan cleanup");
3017 		return;
3018 	}
3019 
3020 	/* Check if feature set would not allow a r/w mount */
3021 	if (!ext4_feature_set_ok(sb, 0)) {
3022 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
3023 			 "unknown ROCOMPAT features");
3024 		return;
3025 	}
3026 
3027 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3028 		/* don't clear list on RO mount w/ errors */
3029 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
3030 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
3031 				  "clearing orphan list.\n");
3032 			es->s_last_orphan = 0;
3033 		}
3034 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3035 		return;
3036 	}
3037 
3038 	if (s_flags & SB_RDONLY) {
3039 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
3040 		sb->s_flags &= ~SB_RDONLY;
3041 	}
3042 #ifdef CONFIG_QUOTA
3043 	/* Needed for iput() to work correctly and not trash data */
3044 	sb->s_flags |= SB_ACTIVE;
3045 
3046 	/*
3047 	 * Turn on quotas which were not enabled for read-only mounts if
3048 	 * filesystem has quota feature, so that they are updated correctly.
3049 	 */
3050 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
3051 		int ret = ext4_enable_quotas(sb);
3052 
3053 		if (!ret)
3054 			quota_update = 1;
3055 		else
3056 			ext4_msg(sb, KERN_ERR,
3057 				"Cannot turn on quotas: error %d", ret);
3058 	}
3059 
3060 	/* Turn on journaled quotas used for old sytle */
3061 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3062 		if (EXT4_SB(sb)->s_qf_names[i]) {
3063 			int ret = ext4_quota_on_mount(sb, i);
3064 
3065 			if (!ret)
3066 				quota_update = 1;
3067 			else
3068 				ext4_msg(sb, KERN_ERR,
3069 					"Cannot turn on journaled "
3070 					"quota: type %d: error %d", i, ret);
3071 		}
3072 	}
3073 #endif
3074 
3075 	while (es->s_last_orphan) {
3076 		struct inode *inode;
3077 
3078 		/*
3079 		 * We may have encountered an error during cleanup; if
3080 		 * so, skip the rest.
3081 		 */
3082 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
3083 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
3084 			es->s_last_orphan = 0;
3085 			break;
3086 		}
3087 
3088 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
3089 		if (IS_ERR(inode)) {
3090 			es->s_last_orphan = 0;
3091 			break;
3092 		}
3093 
3094 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
3095 		dquot_initialize(inode);
3096 		if (inode->i_nlink) {
3097 			if (test_opt(sb, DEBUG))
3098 				ext4_msg(sb, KERN_DEBUG,
3099 					"%s: truncating inode %lu to %lld bytes",
3100 					__func__, inode->i_ino, inode->i_size);
3101 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
3102 				  inode->i_ino, inode->i_size);
3103 			inode_lock(inode);
3104 			truncate_inode_pages(inode->i_mapping, inode->i_size);
3105 			ret = ext4_truncate(inode);
3106 			if (ret)
3107 				ext4_std_error(inode->i_sb, ret);
3108 			inode_unlock(inode);
3109 			nr_truncates++;
3110 		} else {
3111 			if (test_opt(sb, DEBUG))
3112 				ext4_msg(sb, KERN_DEBUG,
3113 					"%s: deleting unreferenced inode %lu",
3114 					__func__, inode->i_ino);
3115 			jbd_debug(2, "deleting unreferenced inode %lu\n",
3116 				  inode->i_ino);
3117 			nr_orphans++;
3118 		}
3119 		iput(inode);  /* The delete magic happens here! */
3120 	}
3121 
3122 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
3123 
3124 	if (nr_orphans)
3125 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
3126 		       PLURAL(nr_orphans));
3127 	if (nr_truncates)
3128 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
3129 		       PLURAL(nr_truncates));
3130 #ifdef CONFIG_QUOTA
3131 	/* Turn off quotas if they were enabled for orphan cleanup */
3132 	if (quota_update) {
3133 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
3134 			if (sb_dqopt(sb)->files[i])
3135 				dquot_quota_off(sb, i);
3136 		}
3137 	}
3138 #endif
3139 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
3140 }
3141 
3142 /*
3143  * Maximal extent format file size.
3144  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3145  * extent format containers, within a sector_t, and within i_blocks
3146  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3147  * so that won't be a limiting factor.
3148  *
3149  * However there is other limiting factor. We do store extents in the form
3150  * of starting block and length, hence the resulting length of the extent
3151  * covering maximum file size must fit into on-disk format containers as
3152  * well. Given that length is always by 1 unit bigger than max unit (because
3153  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3154  *
3155  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3156  */
3157 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3158 {
3159 	loff_t res;
3160 	loff_t upper_limit = MAX_LFS_FILESIZE;
3161 
3162 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3163 
3164 	if (!has_huge_files) {
3165 		upper_limit = (1LL << 32) - 1;
3166 
3167 		/* total blocks in file system block size */
3168 		upper_limit >>= (blkbits - 9);
3169 		upper_limit <<= blkbits;
3170 	}
3171 
3172 	/*
3173 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
3174 	 * by one fs block, so ee_len can cover the extent of maximum file
3175 	 * size
3176 	 */
3177 	res = (1LL << 32) - 1;
3178 	res <<= blkbits;
3179 
3180 	/* Sanity check against vm- & vfs- imposed limits */
3181 	if (res > upper_limit)
3182 		res = upper_limit;
3183 
3184 	return res;
3185 }
3186 
3187 /*
3188  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3189  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3190  * We need to be 1 filesystem block less than the 2^48 sector limit.
3191  */
3192 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3193 {
3194 	loff_t res = EXT4_NDIR_BLOCKS;
3195 	int meta_blocks;
3196 	loff_t upper_limit;
3197 	/* This is calculated to be the largest file size for a dense, block
3198 	 * mapped file such that the file's total number of 512-byte sectors,
3199 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
3200 	 *
3201 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3202 	 * number of 512-byte sectors of the file.
3203 	 */
3204 
3205 	if (!has_huge_files) {
3206 		/*
3207 		 * !has_huge_files or implies that the inode i_block field
3208 		 * represents total file blocks in 2^32 512-byte sectors ==
3209 		 * size of vfs inode i_blocks * 8
3210 		 */
3211 		upper_limit = (1LL << 32) - 1;
3212 
3213 		/* total blocks in file system block size */
3214 		upper_limit >>= (bits - 9);
3215 
3216 	} else {
3217 		/*
3218 		 * We use 48 bit ext4_inode i_blocks
3219 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3220 		 * represent total number of blocks in
3221 		 * file system block size
3222 		 */
3223 		upper_limit = (1LL << 48) - 1;
3224 
3225 	}
3226 
3227 	/* indirect blocks */
3228 	meta_blocks = 1;
3229 	/* double indirect blocks */
3230 	meta_blocks += 1 + (1LL << (bits-2));
3231 	/* tripple indirect blocks */
3232 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3233 
3234 	upper_limit -= meta_blocks;
3235 	upper_limit <<= bits;
3236 
3237 	res += 1LL << (bits-2);
3238 	res += 1LL << (2*(bits-2));
3239 	res += 1LL << (3*(bits-2));
3240 	res <<= bits;
3241 	if (res > upper_limit)
3242 		res = upper_limit;
3243 
3244 	if (res > MAX_LFS_FILESIZE)
3245 		res = MAX_LFS_FILESIZE;
3246 
3247 	return res;
3248 }
3249 
3250 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3251 				   ext4_fsblk_t logical_sb_block, int nr)
3252 {
3253 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3254 	ext4_group_t bg, first_meta_bg;
3255 	int has_super = 0;
3256 
3257 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3258 
3259 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3260 		return logical_sb_block + nr + 1;
3261 	bg = sbi->s_desc_per_block * nr;
3262 	if (ext4_bg_has_super(sb, bg))
3263 		has_super = 1;
3264 
3265 	/*
3266 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3267 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3268 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3269 	 * compensate.
3270 	 */
3271 	if (sb->s_blocksize == 1024 && nr == 0 &&
3272 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3273 		has_super++;
3274 
3275 	return (has_super + ext4_group_first_block_no(sb, bg));
3276 }
3277 
3278 /**
3279  * ext4_get_stripe_size: Get the stripe size.
3280  * @sbi: In memory super block info
3281  *
3282  * If we have specified it via mount option, then
3283  * use the mount option value. If the value specified at mount time is
3284  * greater than the blocks per group use the super block value.
3285  * If the super block value is greater than blocks per group return 0.
3286  * Allocator needs it be less than blocks per group.
3287  *
3288  */
3289 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3290 {
3291 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3292 	unsigned long stripe_width =
3293 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3294 	int ret;
3295 
3296 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3297 		ret = sbi->s_stripe;
3298 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3299 		ret = stripe_width;
3300 	else if (stride && stride <= sbi->s_blocks_per_group)
3301 		ret = stride;
3302 	else
3303 		ret = 0;
3304 
3305 	/*
3306 	 * If the stripe width is 1, this makes no sense and
3307 	 * we set it to 0 to turn off stripe handling code.
3308 	 */
3309 	if (ret <= 1)
3310 		ret = 0;
3311 
3312 	return ret;
3313 }
3314 
3315 /*
3316  * Check whether this filesystem can be mounted based on
3317  * the features present and the RDONLY/RDWR mount requested.
3318  * Returns 1 if this filesystem can be mounted as requested,
3319  * 0 if it cannot be.
3320  */
3321 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3322 {
3323 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3324 		ext4_msg(sb, KERN_ERR,
3325 			"Couldn't mount because of "
3326 			"unsupported optional features (%x)",
3327 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3328 			~EXT4_FEATURE_INCOMPAT_SUPP));
3329 		return 0;
3330 	}
3331 
3332 #ifndef CONFIG_UNICODE
3333 	if (ext4_has_feature_casefold(sb)) {
3334 		ext4_msg(sb, KERN_ERR,
3335 			 "Filesystem with casefold feature cannot be "
3336 			 "mounted without CONFIG_UNICODE");
3337 		return 0;
3338 	}
3339 #endif
3340 
3341 	if (readonly)
3342 		return 1;
3343 
3344 	if (ext4_has_feature_readonly(sb)) {
3345 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3346 		sb->s_flags |= SB_RDONLY;
3347 		return 1;
3348 	}
3349 
3350 	/* Check that feature set is OK for a read-write mount */
3351 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3352 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3353 			 "unsupported optional features (%x)",
3354 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3355 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3356 		return 0;
3357 	}
3358 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3359 		ext4_msg(sb, KERN_ERR,
3360 			 "Can't support bigalloc feature without "
3361 			 "extents feature\n");
3362 		return 0;
3363 	}
3364 
3365 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3366 	if (!readonly && (ext4_has_feature_quota(sb) ||
3367 			  ext4_has_feature_project(sb))) {
3368 		ext4_msg(sb, KERN_ERR,
3369 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3370 		return 0;
3371 	}
3372 #endif  /* CONFIG_QUOTA */
3373 	return 1;
3374 }
3375 
3376 /*
3377  * This function is called once a day if we have errors logged
3378  * on the file system
3379  */
3380 static void print_daily_error_info(struct timer_list *t)
3381 {
3382 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3383 	struct super_block *sb = sbi->s_sb;
3384 	struct ext4_super_block *es = sbi->s_es;
3385 
3386 	if (es->s_error_count)
3387 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3388 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3389 			 le32_to_cpu(es->s_error_count));
3390 	if (es->s_first_error_time) {
3391 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3392 		       sb->s_id,
3393 		       ext4_get_tstamp(es, s_first_error_time),
3394 		       (int) sizeof(es->s_first_error_func),
3395 		       es->s_first_error_func,
3396 		       le32_to_cpu(es->s_first_error_line));
3397 		if (es->s_first_error_ino)
3398 			printk(KERN_CONT ": inode %u",
3399 			       le32_to_cpu(es->s_first_error_ino));
3400 		if (es->s_first_error_block)
3401 			printk(KERN_CONT ": block %llu", (unsigned long long)
3402 			       le64_to_cpu(es->s_first_error_block));
3403 		printk(KERN_CONT "\n");
3404 	}
3405 	if (es->s_last_error_time) {
3406 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3407 		       sb->s_id,
3408 		       ext4_get_tstamp(es, s_last_error_time),
3409 		       (int) sizeof(es->s_last_error_func),
3410 		       es->s_last_error_func,
3411 		       le32_to_cpu(es->s_last_error_line));
3412 		if (es->s_last_error_ino)
3413 			printk(KERN_CONT ": inode %u",
3414 			       le32_to_cpu(es->s_last_error_ino));
3415 		if (es->s_last_error_block)
3416 			printk(KERN_CONT ": block %llu", (unsigned long long)
3417 			       le64_to_cpu(es->s_last_error_block));
3418 		printk(KERN_CONT "\n");
3419 	}
3420 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3421 }
3422 
3423 /* Find next suitable group and run ext4_init_inode_table */
3424 static int ext4_run_li_request(struct ext4_li_request *elr)
3425 {
3426 	struct ext4_group_desc *gdp = NULL;
3427 	struct super_block *sb = elr->lr_super;
3428 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3429 	ext4_group_t group = elr->lr_next_group;
3430 	unsigned long timeout = 0;
3431 	unsigned int prefetch_ios = 0;
3432 	int ret = 0;
3433 
3434 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3435 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3436 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3437 		if (prefetch_ios)
3438 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3439 					      prefetch_ios);
3440 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3441 					    prefetch_ios);
3442 		if (group >= elr->lr_next_group) {
3443 			ret = 1;
3444 			if (elr->lr_first_not_zeroed != ngroups &&
3445 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3446 				elr->lr_next_group = elr->lr_first_not_zeroed;
3447 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3448 				ret = 0;
3449 			}
3450 		}
3451 		return ret;
3452 	}
3453 
3454 	for (; group < ngroups; group++) {
3455 		gdp = ext4_get_group_desc(sb, group, NULL);
3456 		if (!gdp) {
3457 			ret = 1;
3458 			break;
3459 		}
3460 
3461 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3462 			break;
3463 	}
3464 
3465 	if (group >= ngroups)
3466 		ret = 1;
3467 
3468 	if (!ret) {
3469 		timeout = jiffies;
3470 		ret = ext4_init_inode_table(sb, group,
3471 					    elr->lr_timeout ? 0 : 1);
3472 		trace_ext4_lazy_itable_init(sb, group);
3473 		if (elr->lr_timeout == 0) {
3474 			timeout = (jiffies - timeout) *
3475 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3476 			elr->lr_timeout = timeout;
3477 		}
3478 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3479 		elr->lr_next_group = group + 1;
3480 	}
3481 	return ret;
3482 }
3483 
3484 /*
3485  * Remove lr_request from the list_request and free the
3486  * request structure. Should be called with li_list_mtx held
3487  */
3488 static void ext4_remove_li_request(struct ext4_li_request *elr)
3489 {
3490 	if (!elr)
3491 		return;
3492 
3493 	list_del(&elr->lr_request);
3494 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3495 	kfree(elr);
3496 }
3497 
3498 static void ext4_unregister_li_request(struct super_block *sb)
3499 {
3500 	mutex_lock(&ext4_li_mtx);
3501 	if (!ext4_li_info) {
3502 		mutex_unlock(&ext4_li_mtx);
3503 		return;
3504 	}
3505 
3506 	mutex_lock(&ext4_li_info->li_list_mtx);
3507 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3508 	mutex_unlock(&ext4_li_info->li_list_mtx);
3509 	mutex_unlock(&ext4_li_mtx);
3510 }
3511 
3512 static struct task_struct *ext4_lazyinit_task;
3513 
3514 /*
3515  * This is the function where ext4lazyinit thread lives. It walks
3516  * through the request list searching for next scheduled filesystem.
3517  * When such a fs is found, run the lazy initialization request
3518  * (ext4_rn_li_request) and keep track of the time spend in this
3519  * function. Based on that time we compute next schedule time of
3520  * the request. When walking through the list is complete, compute
3521  * next waking time and put itself into sleep.
3522  */
3523 static int ext4_lazyinit_thread(void *arg)
3524 {
3525 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3526 	struct list_head *pos, *n;
3527 	struct ext4_li_request *elr;
3528 	unsigned long next_wakeup, cur;
3529 
3530 	BUG_ON(NULL == eli);
3531 
3532 cont_thread:
3533 	while (true) {
3534 		next_wakeup = MAX_JIFFY_OFFSET;
3535 
3536 		mutex_lock(&eli->li_list_mtx);
3537 		if (list_empty(&eli->li_request_list)) {
3538 			mutex_unlock(&eli->li_list_mtx);
3539 			goto exit_thread;
3540 		}
3541 		list_for_each_safe(pos, n, &eli->li_request_list) {
3542 			int err = 0;
3543 			int progress = 0;
3544 			elr = list_entry(pos, struct ext4_li_request,
3545 					 lr_request);
3546 
3547 			if (time_before(jiffies, elr->lr_next_sched)) {
3548 				if (time_before(elr->lr_next_sched, next_wakeup))
3549 					next_wakeup = elr->lr_next_sched;
3550 				continue;
3551 			}
3552 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3553 				if (sb_start_write_trylock(elr->lr_super)) {
3554 					progress = 1;
3555 					/*
3556 					 * We hold sb->s_umount, sb can not
3557 					 * be removed from the list, it is
3558 					 * now safe to drop li_list_mtx
3559 					 */
3560 					mutex_unlock(&eli->li_list_mtx);
3561 					err = ext4_run_li_request(elr);
3562 					sb_end_write(elr->lr_super);
3563 					mutex_lock(&eli->li_list_mtx);
3564 					n = pos->next;
3565 				}
3566 				up_read((&elr->lr_super->s_umount));
3567 			}
3568 			/* error, remove the lazy_init job */
3569 			if (err) {
3570 				ext4_remove_li_request(elr);
3571 				continue;
3572 			}
3573 			if (!progress) {
3574 				elr->lr_next_sched = jiffies +
3575 					(prandom_u32()
3576 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3577 			}
3578 			if (time_before(elr->lr_next_sched, next_wakeup))
3579 				next_wakeup = elr->lr_next_sched;
3580 		}
3581 		mutex_unlock(&eli->li_list_mtx);
3582 
3583 		try_to_freeze();
3584 
3585 		cur = jiffies;
3586 		if ((time_after_eq(cur, next_wakeup)) ||
3587 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3588 			cond_resched();
3589 			continue;
3590 		}
3591 
3592 		schedule_timeout_interruptible(next_wakeup - cur);
3593 
3594 		if (kthread_should_stop()) {
3595 			ext4_clear_request_list();
3596 			goto exit_thread;
3597 		}
3598 	}
3599 
3600 exit_thread:
3601 	/*
3602 	 * It looks like the request list is empty, but we need
3603 	 * to check it under the li_list_mtx lock, to prevent any
3604 	 * additions into it, and of course we should lock ext4_li_mtx
3605 	 * to atomically free the list and ext4_li_info, because at
3606 	 * this point another ext4 filesystem could be registering
3607 	 * new one.
3608 	 */
3609 	mutex_lock(&ext4_li_mtx);
3610 	mutex_lock(&eli->li_list_mtx);
3611 	if (!list_empty(&eli->li_request_list)) {
3612 		mutex_unlock(&eli->li_list_mtx);
3613 		mutex_unlock(&ext4_li_mtx);
3614 		goto cont_thread;
3615 	}
3616 	mutex_unlock(&eli->li_list_mtx);
3617 	kfree(ext4_li_info);
3618 	ext4_li_info = NULL;
3619 	mutex_unlock(&ext4_li_mtx);
3620 
3621 	return 0;
3622 }
3623 
3624 static void ext4_clear_request_list(void)
3625 {
3626 	struct list_head *pos, *n;
3627 	struct ext4_li_request *elr;
3628 
3629 	mutex_lock(&ext4_li_info->li_list_mtx);
3630 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3631 		elr = list_entry(pos, struct ext4_li_request,
3632 				 lr_request);
3633 		ext4_remove_li_request(elr);
3634 	}
3635 	mutex_unlock(&ext4_li_info->li_list_mtx);
3636 }
3637 
3638 static int ext4_run_lazyinit_thread(void)
3639 {
3640 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3641 					 ext4_li_info, "ext4lazyinit");
3642 	if (IS_ERR(ext4_lazyinit_task)) {
3643 		int err = PTR_ERR(ext4_lazyinit_task);
3644 		ext4_clear_request_list();
3645 		kfree(ext4_li_info);
3646 		ext4_li_info = NULL;
3647 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3648 				 "initialization thread\n",
3649 				 err);
3650 		return err;
3651 	}
3652 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3653 	return 0;
3654 }
3655 
3656 /*
3657  * Check whether it make sense to run itable init. thread or not.
3658  * If there is at least one uninitialized inode table, return
3659  * corresponding group number, else the loop goes through all
3660  * groups and return total number of groups.
3661  */
3662 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3663 {
3664 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3665 	struct ext4_group_desc *gdp = NULL;
3666 
3667 	if (!ext4_has_group_desc_csum(sb))
3668 		return ngroups;
3669 
3670 	for (group = 0; group < ngroups; group++) {
3671 		gdp = ext4_get_group_desc(sb, group, NULL);
3672 		if (!gdp)
3673 			continue;
3674 
3675 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3676 			break;
3677 	}
3678 
3679 	return group;
3680 }
3681 
3682 static int ext4_li_info_new(void)
3683 {
3684 	struct ext4_lazy_init *eli = NULL;
3685 
3686 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3687 	if (!eli)
3688 		return -ENOMEM;
3689 
3690 	INIT_LIST_HEAD(&eli->li_request_list);
3691 	mutex_init(&eli->li_list_mtx);
3692 
3693 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3694 
3695 	ext4_li_info = eli;
3696 
3697 	return 0;
3698 }
3699 
3700 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3701 					    ext4_group_t start)
3702 {
3703 	struct ext4_li_request *elr;
3704 
3705 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3706 	if (!elr)
3707 		return NULL;
3708 
3709 	elr->lr_super = sb;
3710 	elr->lr_first_not_zeroed = start;
3711 	if (test_opt(sb, PREFETCH_BLOCK_BITMAPS))
3712 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3713 	else {
3714 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3715 		elr->lr_next_group = start;
3716 	}
3717 
3718 	/*
3719 	 * Randomize first schedule time of the request to
3720 	 * spread the inode table initialization requests
3721 	 * better.
3722 	 */
3723 	elr->lr_next_sched = jiffies + (prandom_u32() %
3724 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3725 	return elr;
3726 }
3727 
3728 int ext4_register_li_request(struct super_block *sb,
3729 			     ext4_group_t first_not_zeroed)
3730 {
3731 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3732 	struct ext4_li_request *elr = NULL;
3733 	ext4_group_t ngroups = sbi->s_groups_count;
3734 	int ret = 0;
3735 
3736 	mutex_lock(&ext4_li_mtx);
3737 	if (sbi->s_li_request != NULL) {
3738 		/*
3739 		 * Reset timeout so it can be computed again, because
3740 		 * s_li_wait_mult might have changed.
3741 		 */
3742 		sbi->s_li_request->lr_timeout = 0;
3743 		goto out;
3744 	}
3745 
3746 	if (!test_opt(sb, PREFETCH_BLOCK_BITMAPS) &&
3747 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3748 	     !test_opt(sb, INIT_INODE_TABLE)))
3749 		goto out;
3750 
3751 	elr = ext4_li_request_new(sb, first_not_zeroed);
3752 	if (!elr) {
3753 		ret = -ENOMEM;
3754 		goto out;
3755 	}
3756 
3757 	if (NULL == ext4_li_info) {
3758 		ret = ext4_li_info_new();
3759 		if (ret)
3760 			goto out;
3761 	}
3762 
3763 	mutex_lock(&ext4_li_info->li_list_mtx);
3764 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3765 	mutex_unlock(&ext4_li_info->li_list_mtx);
3766 
3767 	sbi->s_li_request = elr;
3768 	/*
3769 	 * set elr to NULL here since it has been inserted to
3770 	 * the request_list and the removal and free of it is
3771 	 * handled by ext4_clear_request_list from now on.
3772 	 */
3773 	elr = NULL;
3774 
3775 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3776 		ret = ext4_run_lazyinit_thread();
3777 		if (ret)
3778 			goto out;
3779 	}
3780 out:
3781 	mutex_unlock(&ext4_li_mtx);
3782 	if (ret)
3783 		kfree(elr);
3784 	return ret;
3785 }
3786 
3787 /*
3788  * We do not need to lock anything since this is called on
3789  * module unload.
3790  */
3791 static void ext4_destroy_lazyinit_thread(void)
3792 {
3793 	/*
3794 	 * If thread exited earlier
3795 	 * there's nothing to be done.
3796 	 */
3797 	if (!ext4_li_info || !ext4_lazyinit_task)
3798 		return;
3799 
3800 	kthread_stop(ext4_lazyinit_task);
3801 }
3802 
3803 static int set_journal_csum_feature_set(struct super_block *sb)
3804 {
3805 	int ret = 1;
3806 	int compat, incompat;
3807 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3808 
3809 	if (ext4_has_metadata_csum(sb)) {
3810 		/* journal checksum v3 */
3811 		compat = 0;
3812 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3813 	} else {
3814 		/* journal checksum v1 */
3815 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3816 		incompat = 0;
3817 	}
3818 
3819 	jbd2_journal_clear_features(sbi->s_journal,
3820 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3821 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3822 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3823 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3824 		ret = jbd2_journal_set_features(sbi->s_journal,
3825 				compat, 0,
3826 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3827 				incompat);
3828 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3829 		ret = jbd2_journal_set_features(sbi->s_journal,
3830 				compat, 0,
3831 				incompat);
3832 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3833 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3834 	} else {
3835 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3836 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3837 	}
3838 
3839 	return ret;
3840 }
3841 
3842 /*
3843  * Note: calculating the overhead so we can be compatible with
3844  * historical BSD practice is quite difficult in the face of
3845  * clusters/bigalloc.  This is because multiple metadata blocks from
3846  * different block group can end up in the same allocation cluster.
3847  * Calculating the exact overhead in the face of clustered allocation
3848  * requires either O(all block bitmaps) in memory or O(number of block
3849  * groups**2) in time.  We will still calculate the superblock for
3850  * older file systems --- and if we come across with a bigalloc file
3851  * system with zero in s_overhead_clusters the estimate will be close to
3852  * correct especially for very large cluster sizes --- but for newer
3853  * file systems, it's better to calculate this figure once at mkfs
3854  * time, and store it in the superblock.  If the superblock value is
3855  * present (even for non-bigalloc file systems), we will use it.
3856  */
3857 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3858 			  char *buf)
3859 {
3860 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3861 	struct ext4_group_desc	*gdp;
3862 	ext4_fsblk_t		first_block, last_block, b;
3863 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3864 	int			s, j, count = 0;
3865 
3866 	if (!ext4_has_feature_bigalloc(sb))
3867 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3868 			sbi->s_itb_per_group + 2);
3869 
3870 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3871 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3872 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3873 	for (i = 0; i < ngroups; i++) {
3874 		gdp = ext4_get_group_desc(sb, i, NULL);
3875 		b = ext4_block_bitmap(sb, gdp);
3876 		if (b >= first_block && b <= last_block) {
3877 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3878 			count++;
3879 		}
3880 		b = ext4_inode_bitmap(sb, gdp);
3881 		if (b >= first_block && b <= last_block) {
3882 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3883 			count++;
3884 		}
3885 		b = ext4_inode_table(sb, gdp);
3886 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3887 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3888 				int c = EXT4_B2C(sbi, b - first_block);
3889 				ext4_set_bit(c, buf);
3890 				count++;
3891 			}
3892 		if (i != grp)
3893 			continue;
3894 		s = 0;
3895 		if (ext4_bg_has_super(sb, grp)) {
3896 			ext4_set_bit(s++, buf);
3897 			count++;
3898 		}
3899 		j = ext4_bg_num_gdb(sb, grp);
3900 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3901 			ext4_error(sb, "Invalid number of block group "
3902 				   "descriptor blocks: %d", j);
3903 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3904 		}
3905 		count += j;
3906 		for (; j > 0; j--)
3907 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3908 	}
3909 	if (!count)
3910 		return 0;
3911 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3912 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3913 }
3914 
3915 /*
3916  * Compute the overhead and stash it in sbi->s_overhead
3917  */
3918 int ext4_calculate_overhead(struct super_block *sb)
3919 {
3920 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3921 	struct ext4_super_block *es = sbi->s_es;
3922 	struct inode *j_inode;
3923 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3924 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3925 	ext4_fsblk_t overhead = 0;
3926 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3927 
3928 	if (!buf)
3929 		return -ENOMEM;
3930 
3931 	/*
3932 	 * Compute the overhead (FS structures).  This is constant
3933 	 * for a given filesystem unless the number of block groups
3934 	 * changes so we cache the previous value until it does.
3935 	 */
3936 
3937 	/*
3938 	 * All of the blocks before first_data_block are overhead
3939 	 */
3940 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3941 
3942 	/*
3943 	 * Add the overhead found in each block group
3944 	 */
3945 	for (i = 0; i < ngroups; i++) {
3946 		int blks;
3947 
3948 		blks = count_overhead(sb, i, buf);
3949 		overhead += blks;
3950 		if (blks)
3951 			memset(buf, 0, PAGE_SIZE);
3952 		cond_resched();
3953 	}
3954 
3955 	/*
3956 	 * Add the internal journal blocks whether the journal has been
3957 	 * loaded or not
3958 	 */
3959 	if (sbi->s_journal && !sbi->s_journal_bdev)
3960 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
3961 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3962 		/* j_inum for internal journal is non-zero */
3963 		j_inode = ext4_get_journal_inode(sb, j_inum);
3964 		if (j_inode) {
3965 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3966 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3967 			iput(j_inode);
3968 		} else {
3969 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3970 		}
3971 	}
3972 	sbi->s_overhead = overhead;
3973 	smp_wmb();
3974 	free_page((unsigned long) buf);
3975 	return 0;
3976 }
3977 
3978 static void ext4_set_resv_clusters(struct super_block *sb)
3979 {
3980 	ext4_fsblk_t resv_clusters;
3981 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3982 
3983 	/*
3984 	 * There's no need to reserve anything when we aren't using extents.
3985 	 * The space estimates are exact, there are no unwritten extents,
3986 	 * hole punching doesn't need new metadata... This is needed especially
3987 	 * to keep ext2/3 backward compatibility.
3988 	 */
3989 	if (!ext4_has_feature_extents(sb))
3990 		return;
3991 	/*
3992 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3993 	 * This should cover the situations where we can not afford to run
3994 	 * out of space like for example punch hole, or converting
3995 	 * unwritten extents in delalloc path. In most cases such
3996 	 * allocation would require 1, or 2 blocks, higher numbers are
3997 	 * very rare.
3998 	 */
3999 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4000 			 sbi->s_cluster_bits);
4001 
4002 	do_div(resv_clusters, 50);
4003 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4004 
4005 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4006 }
4007 
4008 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
4009 {
4010 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
4011 	char *orig_data = kstrdup(data, GFP_KERNEL);
4012 	struct buffer_head *bh, **group_desc;
4013 	struct ext4_super_block *es = NULL;
4014 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4015 	struct flex_groups **flex_groups;
4016 	ext4_fsblk_t block;
4017 	ext4_fsblk_t sb_block = get_sb_block(&data);
4018 	ext4_fsblk_t logical_sb_block;
4019 	unsigned long offset = 0;
4020 	unsigned long journal_devnum = 0;
4021 	unsigned long def_mount_opts;
4022 	struct inode *root;
4023 	const char *descr;
4024 	int ret = -ENOMEM;
4025 	int blocksize, clustersize;
4026 	unsigned int db_count;
4027 	unsigned int i;
4028 	int needs_recovery, has_huge_files;
4029 	__u64 blocks_count;
4030 	int err = 0;
4031 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4032 	ext4_group_t first_not_zeroed;
4033 
4034 	if ((data && !orig_data) || !sbi)
4035 		goto out_free_base;
4036 
4037 	sbi->s_daxdev = dax_dev;
4038 	sbi->s_blockgroup_lock =
4039 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4040 	if (!sbi->s_blockgroup_lock)
4041 		goto out_free_base;
4042 
4043 	sb->s_fs_info = sbi;
4044 	sbi->s_sb = sb;
4045 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4046 	sbi->s_sb_block = sb_block;
4047 	if (sb->s_bdev->bd_part)
4048 		sbi->s_sectors_written_start =
4049 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
4050 
4051 	/* Cleanup superblock name */
4052 	strreplace(sb->s_id, '/', '!');
4053 
4054 	/* -EINVAL is default */
4055 	ret = -EINVAL;
4056 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4057 	if (!blocksize) {
4058 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4059 		goto out_fail;
4060 	}
4061 
4062 	/*
4063 	 * The ext4 superblock will not be buffer aligned for other than 1kB
4064 	 * block sizes.  We need to calculate the offset from buffer start.
4065 	 */
4066 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4067 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4068 		offset = do_div(logical_sb_block, blocksize);
4069 	} else {
4070 		logical_sb_block = sb_block;
4071 	}
4072 
4073 	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4074 	if (IS_ERR(bh)) {
4075 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
4076 		ret = PTR_ERR(bh);
4077 		bh = NULL;
4078 		goto out_fail;
4079 	}
4080 	/*
4081 	 * Note: s_es must be initialized as soon as possible because
4082 	 *       some ext4 macro-instructions depend on its value
4083 	 */
4084 	es = (struct ext4_super_block *) (bh->b_data + offset);
4085 	sbi->s_es = es;
4086 	sb->s_magic = le16_to_cpu(es->s_magic);
4087 	if (sb->s_magic != EXT4_SUPER_MAGIC)
4088 		goto cantfind_ext4;
4089 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4090 
4091 	/* Warn if metadata_csum and gdt_csum are both set. */
4092 	if (ext4_has_feature_metadata_csum(sb) &&
4093 	    ext4_has_feature_gdt_csum(sb))
4094 		ext4_warning(sb, "metadata_csum and uninit_bg are "
4095 			     "redundant flags; please run fsck.");
4096 
4097 	/* Check for a known checksum algorithm */
4098 	if (!ext4_verify_csum_type(sb, es)) {
4099 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4100 			 "unknown checksum algorithm.");
4101 		silent = 1;
4102 		goto cantfind_ext4;
4103 	}
4104 
4105 	/* Load the checksum driver */
4106 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4107 	if (IS_ERR(sbi->s_chksum_driver)) {
4108 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4109 		ret = PTR_ERR(sbi->s_chksum_driver);
4110 		sbi->s_chksum_driver = NULL;
4111 		goto failed_mount;
4112 	}
4113 
4114 	/* Check superblock checksum */
4115 	if (!ext4_superblock_csum_verify(sb, es)) {
4116 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4117 			 "invalid superblock checksum.  Run e2fsck?");
4118 		silent = 1;
4119 		ret = -EFSBADCRC;
4120 		goto cantfind_ext4;
4121 	}
4122 
4123 	/* Precompute checksum seed for all metadata */
4124 	if (ext4_has_feature_csum_seed(sb))
4125 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4126 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4127 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4128 					       sizeof(es->s_uuid));
4129 
4130 	/* Set defaults before we parse the mount options */
4131 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4132 	set_opt(sb, INIT_INODE_TABLE);
4133 	if (def_mount_opts & EXT4_DEFM_DEBUG)
4134 		set_opt(sb, DEBUG);
4135 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4136 		set_opt(sb, GRPID);
4137 	if (def_mount_opts & EXT4_DEFM_UID16)
4138 		set_opt(sb, NO_UID32);
4139 	/* xattr user namespace & acls are now defaulted on */
4140 	set_opt(sb, XATTR_USER);
4141 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4142 	set_opt(sb, POSIX_ACL);
4143 #endif
4144 	if (ext4_has_feature_fast_commit(sb))
4145 		set_opt2(sb, JOURNAL_FAST_COMMIT);
4146 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
4147 	if (ext4_has_metadata_csum(sb))
4148 		set_opt(sb, JOURNAL_CHECKSUM);
4149 
4150 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4151 		set_opt(sb, JOURNAL_DATA);
4152 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4153 		set_opt(sb, ORDERED_DATA);
4154 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4155 		set_opt(sb, WRITEBACK_DATA);
4156 
4157 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4158 		set_opt(sb, ERRORS_PANIC);
4159 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4160 		set_opt(sb, ERRORS_CONT);
4161 	else
4162 		set_opt(sb, ERRORS_RO);
4163 	/* block_validity enabled by default; disable with noblock_validity */
4164 	set_opt(sb, BLOCK_VALIDITY);
4165 	if (def_mount_opts & EXT4_DEFM_DISCARD)
4166 		set_opt(sb, DISCARD);
4167 
4168 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4169 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4170 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4171 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4172 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4173 
4174 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4175 		set_opt(sb, BARRIER);
4176 
4177 	/*
4178 	 * enable delayed allocation by default
4179 	 * Use -o nodelalloc to turn it off
4180 	 */
4181 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4182 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4183 		set_opt(sb, DELALLOC);
4184 
4185 	/*
4186 	 * set default s_li_wait_mult for lazyinit, for the case there is
4187 	 * no mount option specified.
4188 	 */
4189 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4190 
4191 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4192 
4193 	if (blocksize == PAGE_SIZE)
4194 		set_opt(sb, DIOREAD_NOLOCK);
4195 
4196 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
4197 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
4198 		ext4_msg(sb, KERN_ERR,
4199 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
4200 			 blocksize, le32_to_cpu(es->s_log_block_size));
4201 		goto failed_mount;
4202 	}
4203 
4204 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4205 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4206 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4207 	} else {
4208 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4209 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4210 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4211 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4212 				 sbi->s_first_ino);
4213 			goto failed_mount;
4214 		}
4215 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4216 		    (!is_power_of_2(sbi->s_inode_size)) ||
4217 		    (sbi->s_inode_size > blocksize)) {
4218 			ext4_msg(sb, KERN_ERR,
4219 			       "unsupported inode size: %d",
4220 			       sbi->s_inode_size);
4221 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4222 			goto failed_mount;
4223 		}
4224 		/*
4225 		 * i_atime_extra is the last extra field available for
4226 		 * [acm]times in struct ext4_inode. Checking for that
4227 		 * field should suffice to ensure we have extra space
4228 		 * for all three.
4229 		 */
4230 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4231 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4232 			sb->s_time_gran = 1;
4233 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4234 		} else {
4235 			sb->s_time_gran = NSEC_PER_SEC;
4236 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4237 		}
4238 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4239 	}
4240 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4241 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4242 			EXT4_GOOD_OLD_INODE_SIZE;
4243 		if (ext4_has_feature_extra_isize(sb)) {
4244 			unsigned v, max = (sbi->s_inode_size -
4245 					   EXT4_GOOD_OLD_INODE_SIZE);
4246 
4247 			v = le16_to_cpu(es->s_want_extra_isize);
4248 			if (v > max) {
4249 				ext4_msg(sb, KERN_ERR,
4250 					 "bad s_want_extra_isize: %d", v);
4251 				goto failed_mount;
4252 			}
4253 			if (sbi->s_want_extra_isize < v)
4254 				sbi->s_want_extra_isize = v;
4255 
4256 			v = le16_to_cpu(es->s_min_extra_isize);
4257 			if (v > max) {
4258 				ext4_msg(sb, KERN_ERR,
4259 					 "bad s_min_extra_isize: %d", v);
4260 				goto failed_mount;
4261 			}
4262 			if (sbi->s_want_extra_isize < v)
4263 				sbi->s_want_extra_isize = v;
4264 		}
4265 	}
4266 
4267 	if (sbi->s_es->s_mount_opts[0]) {
4268 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4269 					      sizeof(sbi->s_es->s_mount_opts),
4270 					      GFP_KERNEL);
4271 		if (!s_mount_opts)
4272 			goto failed_mount;
4273 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
4274 				   &journal_ioprio, 0)) {
4275 			ext4_msg(sb, KERN_WARNING,
4276 				 "failed to parse options in superblock: %s",
4277 				 s_mount_opts);
4278 		}
4279 		kfree(s_mount_opts);
4280 	}
4281 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4282 	if (!parse_options((char *) data, sb, &journal_devnum,
4283 			   &journal_ioprio, 0))
4284 		goto failed_mount;
4285 
4286 #ifdef CONFIG_UNICODE
4287 	if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4288 		const struct ext4_sb_encodings *encoding_info;
4289 		struct unicode_map *encoding;
4290 		__u16 encoding_flags;
4291 
4292 		if (ext4_has_feature_encrypt(sb)) {
4293 			ext4_msg(sb, KERN_ERR,
4294 				 "Can't mount with encoding and encryption");
4295 			goto failed_mount;
4296 		}
4297 
4298 		if (ext4_sb_read_encoding(es, &encoding_info,
4299 					  &encoding_flags)) {
4300 			ext4_msg(sb, KERN_ERR,
4301 				 "Encoding requested by superblock is unknown");
4302 			goto failed_mount;
4303 		}
4304 
4305 		encoding = utf8_load(encoding_info->version);
4306 		if (IS_ERR(encoding)) {
4307 			ext4_msg(sb, KERN_ERR,
4308 				 "can't mount with superblock charset: %s-%s "
4309 				 "not supported by the kernel. flags: 0x%x.",
4310 				 encoding_info->name, encoding_info->version,
4311 				 encoding_flags);
4312 			goto failed_mount;
4313 		}
4314 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4315 			 "%s-%s with flags 0x%hx", encoding_info->name,
4316 			 encoding_info->version?:"\b", encoding_flags);
4317 
4318 		sb->s_encoding = encoding;
4319 		sb->s_encoding_flags = encoding_flags;
4320 	}
4321 #endif
4322 
4323 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4324 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4325 		/* can't mount with both data=journal and dioread_nolock. */
4326 		clear_opt(sb, DIOREAD_NOLOCK);
4327 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4328 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4329 			ext4_msg(sb, KERN_ERR, "can't mount with "
4330 				 "both data=journal and delalloc");
4331 			goto failed_mount;
4332 		}
4333 		if (test_opt(sb, DAX_ALWAYS)) {
4334 			ext4_msg(sb, KERN_ERR, "can't mount with "
4335 				 "both data=journal and dax");
4336 			goto failed_mount;
4337 		}
4338 		if (ext4_has_feature_encrypt(sb)) {
4339 			ext4_msg(sb, KERN_WARNING,
4340 				 "encrypted files will use data=ordered "
4341 				 "instead of data journaling mode");
4342 		}
4343 		if (test_opt(sb, DELALLOC))
4344 			clear_opt(sb, DELALLOC);
4345 	} else {
4346 		sb->s_iflags |= SB_I_CGROUPWB;
4347 	}
4348 
4349 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4350 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4351 
4352 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4353 	    (ext4_has_compat_features(sb) ||
4354 	     ext4_has_ro_compat_features(sb) ||
4355 	     ext4_has_incompat_features(sb)))
4356 		ext4_msg(sb, KERN_WARNING,
4357 		       "feature flags set on rev 0 fs, "
4358 		       "running e2fsck is recommended");
4359 
4360 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4361 		set_opt2(sb, HURD_COMPAT);
4362 		if (ext4_has_feature_64bit(sb)) {
4363 			ext4_msg(sb, KERN_ERR,
4364 				 "The Hurd can't support 64-bit file systems");
4365 			goto failed_mount;
4366 		}
4367 
4368 		/*
4369 		 * ea_inode feature uses l_i_version field which is not
4370 		 * available in HURD_COMPAT mode.
4371 		 */
4372 		if (ext4_has_feature_ea_inode(sb)) {
4373 			ext4_msg(sb, KERN_ERR,
4374 				 "ea_inode feature is not supported for Hurd");
4375 			goto failed_mount;
4376 		}
4377 	}
4378 
4379 	if (IS_EXT2_SB(sb)) {
4380 		if (ext2_feature_set_ok(sb))
4381 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4382 				 "using the ext4 subsystem");
4383 		else {
4384 			/*
4385 			 * If we're probing be silent, if this looks like
4386 			 * it's actually an ext[34] filesystem.
4387 			 */
4388 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4389 				goto failed_mount;
4390 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4391 				 "to feature incompatibilities");
4392 			goto failed_mount;
4393 		}
4394 	}
4395 
4396 	if (IS_EXT3_SB(sb)) {
4397 		if (ext3_feature_set_ok(sb))
4398 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4399 				 "using the ext4 subsystem");
4400 		else {
4401 			/*
4402 			 * If we're probing be silent, if this looks like
4403 			 * it's actually an ext4 filesystem.
4404 			 */
4405 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4406 				goto failed_mount;
4407 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4408 				 "to feature incompatibilities");
4409 			goto failed_mount;
4410 		}
4411 	}
4412 
4413 	/*
4414 	 * Check feature flags regardless of the revision level, since we
4415 	 * previously didn't change the revision level when setting the flags,
4416 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4417 	 */
4418 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4419 		goto failed_mount;
4420 
4421 	if (le32_to_cpu(es->s_log_block_size) >
4422 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4423 		ext4_msg(sb, KERN_ERR,
4424 			 "Invalid log block size: %u",
4425 			 le32_to_cpu(es->s_log_block_size));
4426 		goto failed_mount;
4427 	}
4428 	if (le32_to_cpu(es->s_log_cluster_size) >
4429 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4430 		ext4_msg(sb, KERN_ERR,
4431 			 "Invalid log cluster size: %u",
4432 			 le32_to_cpu(es->s_log_cluster_size));
4433 		goto failed_mount;
4434 	}
4435 
4436 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4437 		ext4_msg(sb, KERN_ERR,
4438 			 "Number of reserved GDT blocks insanely large: %d",
4439 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4440 		goto failed_mount;
4441 	}
4442 
4443 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4444 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4445 
4446 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4447 		if (ext4_has_feature_inline_data(sb)) {
4448 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4449 					" that may contain inline data");
4450 			goto failed_mount;
4451 		}
4452 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4453 			ext4_msg(sb, KERN_ERR,
4454 				"DAX unsupported by block device.");
4455 			goto failed_mount;
4456 		}
4457 	}
4458 
4459 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4460 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4461 			 es->s_encryption_level);
4462 		goto failed_mount;
4463 	}
4464 
4465 	if (sb->s_blocksize != blocksize) {
4466 		/* Validate the filesystem blocksize */
4467 		if (!sb_set_blocksize(sb, blocksize)) {
4468 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4469 					blocksize);
4470 			goto failed_mount;
4471 		}
4472 
4473 		brelse(bh);
4474 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4475 		offset = do_div(logical_sb_block, blocksize);
4476 		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4477 		if (IS_ERR(bh)) {
4478 			ext4_msg(sb, KERN_ERR,
4479 			       "Can't read superblock on 2nd try");
4480 			ret = PTR_ERR(bh);
4481 			bh = NULL;
4482 			goto failed_mount;
4483 		}
4484 		es = (struct ext4_super_block *)(bh->b_data + offset);
4485 		sbi->s_es = es;
4486 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4487 			ext4_msg(sb, KERN_ERR,
4488 			       "Magic mismatch, very weird!");
4489 			goto failed_mount;
4490 		}
4491 	}
4492 
4493 	has_huge_files = ext4_has_feature_huge_file(sb);
4494 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4495 						      has_huge_files);
4496 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4497 
4498 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4499 	if (ext4_has_feature_64bit(sb)) {
4500 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4501 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4502 		    !is_power_of_2(sbi->s_desc_size)) {
4503 			ext4_msg(sb, KERN_ERR,
4504 			       "unsupported descriptor size %lu",
4505 			       sbi->s_desc_size);
4506 			goto failed_mount;
4507 		}
4508 	} else
4509 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4510 
4511 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4512 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4513 
4514 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4515 	if (sbi->s_inodes_per_block == 0)
4516 		goto cantfind_ext4;
4517 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4518 	    sbi->s_inodes_per_group > blocksize * 8) {
4519 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4520 			 sbi->s_inodes_per_group);
4521 		goto failed_mount;
4522 	}
4523 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4524 					sbi->s_inodes_per_block;
4525 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4526 	sbi->s_sbh = bh;
4527 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4528 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4529 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4530 
4531 	for (i = 0; i < 4; i++)
4532 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4533 	sbi->s_def_hash_version = es->s_def_hash_version;
4534 	if (ext4_has_feature_dir_index(sb)) {
4535 		i = le32_to_cpu(es->s_flags);
4536 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4537 			sbi->s_hash_unsigned = 3;
4538 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4539 #ifdef __CHAR_UNSIGNED__
4540 			if (!sb_rdonly(sb))
4541 				es->s_flags |=
4542 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4543 			sbi->s_hash_unsigned = 3;
4544 #else
4545 			if (!sb_rdonly(sb))
4546 				es->s_flags |=
4547 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4548 #endif
4549 		}
4550 	}
4551 
4552 	/* Handle clustersize */
4553 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4554 	if (ext4_has_feature_bigalloc(sb)) {
4555 		if (clustersize < blocksize) {
4556 			ext4_msg(sb, KERN_ERR,
4557 				 "cluster size (%d) smaller than "
4558 				 "block size (%d)", clustersize, blocksize);
4559 			goto failed_mount;
4560 		}
4561 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4562 			le32_to_cpu(es->s_log_block_size);
4563 		sbi->s_clusters_per_group =
4564 			le32_to_cpu(es->s_clusters_per_group);
4565 		if (sbi->s_clusters_per_group > blocksize * 8) {
4566 			ext4_msg(sb, KERN_ERR,
4567 				 "#clusters per group too big: %lu",
4568 				 sbi->s_clusters_per_group);
4569 			goto failed_mount;
4570 		}
4571 		if (sbi->s_blocks_per_group !=
4572 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4573 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4574 				 "clusters per group (%lu) inconsistent",
4575 				 sbi->s_blocks_per_group,
4576 				 sbi->s_clusters_per_group);
4577 			goto failed_mount;
4578 		}
4579 	} else {
4580 		if (clustersize != blocksize) {
4581 			ext4_msg(sb, KERN_ERR,
4582 				 "fragment/cluster size (%d) != "
4583 				 "block size (%d)", clustersize, blocksize);
4584 			goto failed_mount;
4585 		}
4586 		if (sbi->s_blocks_per_group > blocksize * 8) {
4587 			ext4_msg(sb, KERN_ERR,
4588 				 "#blocks per group too big: %lu",
4589 				 sbi->s_blocks_per_group);
4590 			goto failed_mount;
4591 		}
4592 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4593 		sbi->s_cluster_bits = 0;
4594 	}
4595 	sbi->s_cluster_ratio = clustersize / blocksize;
4596 
4597 	/* Do we have standard group size of clustersize * 8 blocks ? */
4598 	if (sbi->s_blocks_per_group == clustersize << 3)
4599 		set_opt2(sb, STD_GROUP_SIZE);
4600 
4601 	/*
4602 	 * Test whether we have more sectors than will fit in sector_t,
4603 	 * and whether the max offset is addressable by the page cache.
4604 	 */
4605 	err = generic_check_addressable(sb->s_blocksize_bits,
4606 					ext4_blocks_count(es));
4607 	if (err) {
4608 		ext4_msg(sb, KERN_ERR, "filesystem"
4609 			 " too large to mount safely on this system");
4610 		goto failed_mount;
4611 	}
4612 
4613 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4614 		goto cantfind_ext4;
4615 
4616 	/* check blocks count against device size */
4617 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4618 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4619 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4620 		       "exceeds size of device (%llu blocks)",
4621 		       ext4_blocks_count(es), blocks_count);
4622 		goto failed_mount;
4623 	}
4624 
4625 	/*
4626 	 * It makes no sense for the first data block to be beyond the end
4627 	 * of the filesystem.
4628 	 */
4629 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4630 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4631 			 "block %u is beyond end of filesystem (%llu)",
4632 			 le32_to_cpu(es->s_first_data_block),
4633 			 ext4_blocks_count(es));
4634 		goto failed_mount;
4635 	}
4636 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4637 	    (sbi->s_cluster_ratio == 1)) {
4638 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4639 			 "block is 0 with a 1k block and cluster size");
4640 		goto failed_mount;
4641 	}
4642 
4643 	blocks_count = (ext4_blocks_count(es) -
4644 			le32_to_cpu(es->s_first_data_block) +
4645 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4646 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4647 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4648 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4649 		       "(block count %llu, first data block %u, "
4650 		       "blocks per group %lu)", blocks_count,
4651 		       ext4_blocks_count(es),
4652 		       le32_to_cpu(es->s_first_data_block),
4653 		       EXT4_BLOCKS_PER_GROUP(sb));
4654 		goto failed_mount;
4655 	}
4656 	sbi->s_groups_count = blocks_count;
4657 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4658 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4659 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4660 	    le32_to_cpu(es->s_inodes_count)) {
4661 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4662 			 le32_to_cpu(es->s_inodes_count),
4663 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4664 		ret = -EINVAL;
4665 		goto failed_mount;
4666 	}
4667 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4668 		   EXT4_DESC_PER_BLOCK(sb);
4669 	if (ext4_has_feature_meta_bg(sb)) {
4670 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4671 			ext4_msg(sb, KERN_WARNING,
4672 				 "first meta block group too large: %u "
4673 				 "(group descriptor block count %u)",
4674 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4675 			goto failed_mount;
4676 		}
4677 	}
4678 	rcu_assign_pointer(sbi->s_group_desc,
4679 			   kvmalloc_array(db_count,
4680 					  sizeof(struct buffer_head *),
4681 					  GFP_KERNEL));
4682 	if (sbi->s_group_desc == NULL) {
4683 		ext4_msg(sb, KERN_ERR, "not enough memory");
4684 		ret = -ENOMEM;
4685 		goto failed_mount;
4686 	}
4687 
4688 	bgl_lock_init(sbi->s_blockgroup_lock);
4689 
4690 	/* Pre-read the descriptors into the buffer cache */
4691 	for (i = 0; i < db_count; i++) {
4692 		block = descriptor_loc(sb, logical_sb_block, i);
4693 		ext4_sb_breadahead_unmovable(sb, block);
4694 	}
4695 
4696 	for (i = 0; i < db_count; i++) {
4697 		struct buffer_head *bh;
4698 
4699 		block = descriptor_loc(sb, logical_sb_block, i);
4700 		bh = ext4_sb_bread_unmovable(sb, block);
4701 		if (IS_ERR(bh)) {
4702 			ext4_msg(sb, KERN_ERR,
4703 			       "can't read group descriptor %d", i);
4704 			db_count = i;
4705 			ret = PTR_ERR(bh);
4706 			bh = NULL;
4707 			goto failed_mount2;
4708 		}
4709 		rcu_read_lock();
4710 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4711 		rcu_read_unlock();
4712 	}
4713 	sbi->s_gdb_count = db_count;
4714 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4715 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4716 		ret = -EFSCORRUPTED;
4717 		goto failed_mount2;
4718 	}
4719 
4720 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4721 
4722 	/* Register extent status tree shrinker */
4723 	if (ext4_es_register_shrinker(sbi))
4724 		goto failed_mount3;
4725 
4726 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4727 	sbi->s_extent_max_zeroout_kb = 32;
4728 
4729 	/*
4730 	 * set up enough so that it can read an inode
4731 	 */
4732 	sb->s_op = &ext4_sops;
4733 	sb->s_export_op = &ext4_export_ops;
4734 	sb->s_xattr = ext4_xattr_handlers;
4735 #ifdef CONFIG_FS_ENCRYPTION
4736 	sb->s_cop = &ext4_cryptops;
4737 #endif
4738 #ifdef CONFIG_FS_VERITY
4739 	sb->s_vop = &ext4_verityops;
4740 #endif
4741 #ifdef CONFIG_QUOTA
4742 	sb->dq_op = &ext4_quota_operations;
4743 	if (ext4_has_feature_quota(sb))
4744 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4745 	else
4746 		sb->s_qcop = &ext4_qctl_operations;
4747 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4748 #endif
4749 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4750 
4751 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4752 	mutex_init(&sbi->s_orphan_lock);
4753 
4754 	/* Initialize fast commit stuff */
4755 	atomic_set(&sbi->s_fc_subtid, 0);
4756 	atomic_set(&sbi->s_fc_ineligible_updates, 0);
4757 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
4758 	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
4759 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
4760 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
4761 	sbi->s_fc_bytes = 0;
4762 	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
4763 	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
4764 	spin_lock_init(&sbi->s_fc_lock);
4765 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
4766 	sbi->s_fc_replay_state.fc_regions = NULL;
4767 	sbi->s_fc_replay_state.fc_regions_size = 0;
4768 	sbi->s_fc_replay_state.fc_regions_used = 0;
4769 	sbi->s_fc_replay_state.fc_regions_valid = 0;
4770 	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
4771 	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
4772 	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
4773 
4774 	sb->s_root = NULL;
4775 
4776 	needs_recovery = (es->s_last_orphan != 0 ||
4777 			  ext4_has_feature_journal_needs_recovery(sb));
4778 
4779 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4780 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4781 			goto failed_mount3a;
4782 
4783 	/*
4784 	 * The first inode we look at is the journal inode.  Don't try
4785 	 * root first: it may be modified in the journal!
4786 	 */
4787 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4788 		err = ext4_load_journal(sb, es, journal_devnum);
4789 		if (err)
4790 			goto failed_mount3a;
4791 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4792 		   ext4_has_feature_journal_needs_recovery(sb)) {
4793 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4794 		       "suppressed and not mounted read-only");
4795 		goto failed_mount_wq;
4796 	} else {
4797 		/* Nojournal mode, all journal mount options are illegal */
4798 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4799 			ext4_msg(sb, KERN_ERR, "can't mount with "
4800 				 "journal_checksum, fs mounted w/o journal");
4801 			goto failed_mount_wq;
4802 		}
4803 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4804 			ext4_msg(sb, KERN_ERR, "can't mount with "
4805 				 "journal_async_commit, fs mounted w/o journal");
4806 			goto failed_mount_wq;
4807 		}
4808 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4809 			ext4_msg(sb, KERN_ERR, "can't mount with "
4810 				 "commit=%lu, fs mounted w/o journal",
4811 				 sbi->s_commit_interval / HZ);
4812 			goto failed_mount_wq;
4813 		}
4814 		if (EXT4_MOUNT_DATA_FLAGS &
4815 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4816 			ext4_msg(sb, KERN_ERR, "can't mount with "
4817 				 "data=, fs mounted w/o journal");
4818 			goto failed_mount_wq;
4819 		}
4820 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4821 		clear_opt(sb, JOURNAL_CHECKSUM);
4822 		clear_opt(sb, DATA_FLAGS);
4823 		clear_opt2(sb, JOURNAL_FAST_COMMIT);
4824 		sbi->s_journal = NULL;
4825 		needs_recovery = 0;
4826 		goto no_journal;
4827 	}
4828 
4829 	if (ext4_has_feature_64bit(sb) &&
4830 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4831 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4832 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4833 		goto failed_mount_wq;
4834 	}
4835 
4836 	if (!set_journal_csum_feature_set(sb)) {
4837 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4838 			 "feature set");
4839 		goto failed_mount_wq;
4840 	}
4841 
4842 	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4843 		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4844 					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
4845 		ext4_msg(sb, KERN_ERR,
4846 			"Failed to set fast commit journal feature");
4847 		goto failed_mount_wq;
4848 	}
4849 
4850 	/* We have now updated the journal if required, so we can
4851 	 * validate the data journaling mode. */
4852 	switch (test_opt(sb, DATA_FLAGS)) {
4853 	case 0:
4854 		/* No mode set, assume a default based on the journal
4855 		 * capabilities: ORDERED_DATA if the journal can
4856 		 * cope, else JOURNAL_DATA
4857 		 */
4858 		if (jbd2_journal_check_available_features
4859 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4860 			set_opt(sb, ORDERED_DATA);
4861 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4862 		} else {
4863 			set_opt(sb, JOURNAL_DATA);
4864 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4865 		}
4866 		break;
4867 
4868 	case EXT4_MOUNT_ORDERED_DATA:
4869 	case EXT4_MOUNT_WRITEBACK_DATA:
4870 		if (!jbd2_journal_check_available_features
4871 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4872 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4873 			       "requested data journaling mode");
4874 			goto failed_mount_wq;
4875 		}
4876 	default:
4877 		break;
4878 	}
4879 
4880 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4881 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4882 		ext4_msg(sb, KERN_ERR, "can't mount with "
4883 			"journal_async_commit in data=ordered mode");
4884 		goto failed_mount_wq;
4885 	}
4886 
4887 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4888 
4889 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4890 	sbi->s_journal->j_submit_inode_data_buffers =
4891 		ext4_journal_submit_inode_data_buffers;
4892 	sbi->s_journal->j_finish_inode_data_buffers =
4893 		ext4_journal_finish_inode_data_buffers;
4894 
4895 no_journal:
4896 	if (!test_opt(sb, NO_MBCACHE)) {
4897 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4898 		if (!sbi->s_ea_block_cache) {
4899 			ext4_msg(sb, KERN_ERR,
4900 				 "Failed to create ea_block_cache");
4901 			goto failed_mount_wq;
4902 		}
4903 
4904 		if (ext4_has_feature_ea_inode(sb)) {
4905 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4906 			if (!sbi->s_ea_inode_cache) {
4907 				ext4_msg(sb, KERN_ERR,
4908 					 "Failed to create ea_inode_cache");
4909 				goto failed_mount_wq;
4910 			}
4911 		}
4912 	}
4913 
4914 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4915 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4916 		goto failed_mount_wq;
4917 	}
4918 
4919 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4920 	    !ext4_has_feature_encrypt(sb)) {
4921 		ext4_set_feature_encrypt(sb);
4922 		ext4_commit_super(sb, 1);
4923 	}
4924 
4925 	/*
4926 	 * Get the # of file system overhead blocks from the
4927 	 * superblock if present.
4928 	 */
4929 	if (es->s_overhead_clusters)
4930 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4931 	else {
4932 		err = ext4_calculate_overhead(sb);
4933 		if (err)
4934 			goto failed_mount_wq;
4935 	}
4936 
4937 	/*
4938 	 * The maximum number of concurrent works can be high and
4939 	 * concurrency isn't really necessary.  Limit it to 1.
4940 	 */
4941 	EXT4_SB(sb)->rsv_conversion_wq =
4942 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4943 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4944 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4945 		ret = -ENOMEM;
4946 		goto failed_mount4;
4947 	}
4948 
4949 	/*
4950 	 * The jbd2_journal_load will have done any necessary log recovery,
4951 	 * so we can safely mount the rest of the filesystem now.
4952 	 */
4953 
4954 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4955 	if (IS_ERR(root)) {
4956 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4957 		ret = PTR_ERR(root);
4958 		root = NULL;
4959 		goto failed_mount4;
4960 	}
4961 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4962 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4963 		iput(root);
4964 		goto failed_mount4;
4965 	}
4966 
4967 #ifdef CONFIG_UNICODE
4968 	if (sb->s_encoding)
4969 		sb->s_d_op = &ext4_dentry_ops;
4970 #endif
4971 
4972 	sb->s_root = d_make_root(root);
4973 	if (!sb->s_root) {
4974 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4975 		ret = -ENOMEM;
4976 		goto failed_mount4;
4977 	}
4978 
4979 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4980 	if (ret == -EROFS) {
4981 		sb->s_flags |= SB_RDONLY;
4982 		ret = 0;
4983 	} else if (ret)
4984 		goto failed_mount4a;
4985 
4986 	ext4_set_resv_clusters(sb);
4987 
4988 	if (test_opt(sb, BLOCK_VALIDITY)) {
4989 		err = ext4_setup_system_zone(sb);
4990 		if (err) {
4991 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
4992 				 "zone (%d)", err);
4993 			goto failed_mount4a;
4994 		}
4995 	}
4996 	ext4_fc_replay_cleanup(sb);
4997 
4998 	ext4_ext_init(sb);
4999 	err = ext4_mb_init(sb);
5000 	if (err) {
5001 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5002 			 err);
5003 		goto failed_mount5;
5004 	}
5005 
5006 	block = ext4_count_free_clusters(sb);
5007 	ext4_free_blocks_count_set(sbi->s_es,
5008 				   EXT4_C2B(sbi, block));
5009 	ext4_superblock_csum_set(sb);
5010 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5011 				  GFP_KERNEL);
5012 	if (!err) {
5013 		unsigned long freei = ext4_count_free_inodes(sb);
5014 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5015 		ext4_superblock_csum_set(sb);
5016 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5017 					  GFP_KERNEL);
5018 	}
5019 	if (!err)
5020 		err = percpu_counter_init(&sbi->s_dirs_counter,
5021 					  ext4_count_dirs(sb), GFP_KERNEL);
5022 	if (!err)
5023 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5024 					  GFP_KERNEL);
5025 	if (!err)
5026 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5027 
5028 	if (err) {
5029 		ext4_msg(sb, KERN_ERR, "insufficient memory");
5030 		goto failed_mount6;
5031 	}
5032 
5033 	if (ext4_has_feature_flex_bg(sb))
5034 		if (!ext4_fill_flex_info(sb)) {
5035 			ext4_msg(sb, KERN_ERR,
5036 			       "unable to initialize "
5037 			       "flex_bg meta info!");
5038 			goto failed_mount6;
5039 		}
5040 
5041 	err = ext4_register_li_request(sb, first_not_zeroed);
5042 	if (err)
5043 		goto failed_mount6;
5044 
5045 	err = ext4_register_sysfs(sb);
5046 	if (err)
5047 		goto failed_mount7;
5048 
5049 #ifdef CONFIG_QUOTA
5050 	/* Enable quota usage during mount. */
5051 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5052 		err = ext4_enable_quotas(sb);
5053 		if (err)
5054 			goto failed_mount8;
5055 	}
5056 #endif  /* CONFIG_QUOTA */
5057 
5058 	/*
5059 	 * Save the original bdev mapping's wb_err value which could be
5060 	 * used to detect the metadata async write error.
5061 	 */
5062 	spin_lock_init(&sbi->s_bdev_wb_lock);
5063 	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5064 				 &sbi->s_bdev_wb_err);
5065 	sb->s_bdev->bd_super = sb;
5066 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5067 	ext4_orphan_cleanup(sb, es);
5068 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5069 	if (needs_recovery) {
5070 		ext4_msg(sb, KERN_INFO, "recovery complete");
5071 		err = ext4_mark_recovery_complete(sb, es);
5072 		if (err)
5073 			goto failed_mount8;
5074 	}
5075 	if (EXT4_SB(sb)->s_journal) {
5076 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5077 			descr = " journalled data mode";
5078 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5079 			descr = " ordered data mode";
5080 		else
5081 			descr = " writeback data mode";
5082 	} else
5083 		descr = "out journal";
5084 
5085 	if (test_opt(sb, DISCARD)) {
5086 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
5087 		if (!blk_queue_discard(q))
5088 			ext4_msg(sb, KERN_WARNING,
5089 				 "mounting with \"discard\" option, but "
5090 				 "the device does not support discard");
5091 	}
5092 
5093 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5094 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5095 			 "Opts: %.*s%s%s", descr,
5096 			 (int) sizeof(sbi->s_es->s_mount_opts),
5097 			 sbi->s_es->s_mount_opts,
5098 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
5099 
5100 	if (es->s_error_count)
5101 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5102 
5103 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5104 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5105 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5106 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5107 	atomic_set(&sbi->s_warning_count, 0);
5108 	atomic_set(&sbi->s_msg_count, 0);
5109 
5110 	kfree(orig_data);
5111 	return 0;
5112 
5113 cantfind_ext4:
5114 	if (!silent)
5115 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5116 	goto failed_mount;
5117 
5118 failed_mount8:
5119 	ext4_unregister_sysfs(sb);
5120 	kobject_put(&sbi->s_kobj);
5121 failed_mount7:
5122 	ext4_unregister_li_request(sb);
5123 failed_mount6:
5124 	ext4_mb_release(sb);
5125 	rcu_read_lock();
5126 	flex_groups = rcu_dereference(sbi->s_flex_groups);
5127 	if (flex_groups) {
5128 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5129 			kvfree(flex_groups[i]);
5130 		kvfree(flex_groups);
5131 	}
5132 	rcu_read_unlock();
5133 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
5134 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
5135 	percpu_counter_destroy(&sbi->s_dirs_counter);
5136 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5137 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
5138 failed_mount5:
5139 	ext4_ext_release(sb);
5140 	ext4_release_system_zone(sb);
5141 failed_mount4a:
5142 	dput(sb->s_root);
5143 	sb->s_root = NULL;
5144 failed_mount4:
5145 	ext4_msg(sb, KERN_ERR, "mount failed");
5146 	if (EXT4_SB(sb)->rsv_conversion_wq)
5147 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5148 failed_mount_wq:
5149 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5150 	sbi->s_ea_inode_cache = NULL;
5151 
5152 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5153 	sbi->s_ea_block_cache = NULL;
5154 
5155 	if (sbi->s_journal) {
5156 		jbd2_journal_destroy(sbi->s_journal);
5157 		sbi->s_journal = NULL;
5158 	}
5159 failed_mount3a:
5160 	ext4_es_unregister_shrinker(sbi);
5161 failed_mount3:
5162 	del_timer_sync(&sbi->s_err_report);
5163 	if (sbi->s_mmp_tsk)
5164 		kthread_stop(sbi->s_mmp_tsk);
5165 failed_mount2:
5166 	rcu_read_lock();
5167 	group_desc = rcu_dereference(sbi->s_group_desc);
5168 	for (i = 0; i < db_count; i++)
5169 		brelse(group_desc[i]);
5170 	kvfree(group_desc);
5171 	rcu_read_unlock();
5172 failed_mount:
5173 	if (sbi->s_chksum_driver)
5174 		crypto_free_shash(sbi->s_chksum_driver);
5175 
5176 #ifdef CONFIG_UNICODE
5177 	utf8_unload(sb->s_encoding);
5178 #endif
5179 
5180 #ifdef CONFIG_QUOTA
5181 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5182 		kfree(get_qf_name(sb, sbi, i));
5183 #endif
5184 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5185 	ext4_blkdev_remove(sbi);
5186 	brelse(bh);
5187 out_fail:
5188 	sb->s_fs_info = NULL;
5189 	kfree(sbi->s_blockgroup_lock);
5190 out_free_base:
5191 	kfree(sbi);
5192 	kfree(orig_data);
5193 	fs_put_dax(dax_dev);
5194 	return err ? err : ret;
5195 }
5196 
5197 /*
5198  * Setup any per-fs journal parameters now.  We'll do this both on
5199  * initial mount, once the journal has been initialised but before we've
5200  * done any recovery; and again on any subsequent remount.
5201  */
5202 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5203 {
5204 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5205 
5206 	journal->j_commit_interval = sbi->s_commit_interval;
5207 	journal->j_min_batch_time = sbi->s_min_batch_time;
5208 	journal->j_max_batch_time = sbi->s_max_batch_time;
5209 	ext4_fc_init(sb, journal);
5210 
5211 	write_lock(&journal->j_state_lock);
5212 	if (test_opt(sb, BARRIER))
5213 		journal->j_flags |= JBD2_BARRIER;
5214 	else
5215 		journal->j_flags &= ~JBD2_BARRIER;
5216 	if (test_opt(sb, DATA_ERR_ABORT))
5217 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5218 	else
5219 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5220 	write_unlock(&journal->j_state_lock);
5221 }
5222 
5223 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5224 					     unsigned int journal_inum)
5225 {
5226 	struct inode *journal_inode;
5227 
5228 	/*
5229 	 * Test for the existence of a valid inode on disk.  Bad things
5230 	 * happen if we iget() an unused inode, as the subsequent iput()
5231 	 * will try to delete it.
5232 	 */
5233 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5234 	if (IS_ERR(journal_inode)) {
5235 		ext4_msg(sb, KERN_ERR, "no journal found");
5236 		return NULL;
5237 	}
5238 	if (!journal_inode->i_nlink) {
5239 		make_bad_inode(journal_inode);
5240 		iput(journal_inode);
5241 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5242 		return NULL;
5243 	}
5244 
5245 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5246 		  journal_inode, journal_inode->i_size);
5247 	if (!S_ISREG(journal_inode->i_mode)) {
5248 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5249 		iput(journal_inode);
5250 		return NULL;
5251 	}
5252 	return journal_inode;
5253 }
5254 
5255 static journal_t *ext4_get_journal(struct super_block *sb,
5256 				   unsigned int journal_inum)
5257 {
5258 	struct inode *journal_inode;
5259 	journal_t *journal;
5260 
5261 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5262 		return NULL;
5263 
5264 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5265 	if (!journal_inode)
5266 		return NULL;
5267 
5268 	journal = jbd2_journal_init_inode(journal_inode);
5269 	if (!journal) {
5270 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5271 		iput(journal_inode);
5272 		return NULL;
5273 	}
5274 	journal->j_private = sb;
5275 	ext4_init_journal_params(sb, journal);
5276 	return journal;
5277 }
5278 
5279 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5280 				       dev_t j_dev)
5281 {
5282 	struct buffer_head *bh;
5283 	journal_t *journal;
5284 	ext4_fsblk_t start;
5285 	ext4_fsblk_t len;
5286 	int hblock, blocksize;
5287 	ext4_fsblk_t sb_block;
5288 	unsigned long offset;
5289 	struct ext4_super_block *es;
5290 	struct block_device *bdev;
5291 
5292 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5293 		return NULL;
5294 
5295 	bdev = ext4_blkdev_get(j_dev, sb);
5296 	if (bdev == NULL)
5297 		return NULL;
5298 
5299 	blocksize = sb->s_blocksize;
5300 	hblock = bdev_logical_block_size(bdev);
5301 	if (blocksize < hblock) {
5302 		ext4_msg(sb, KERN_ERR,
5303 			"blocksize too small for journal device");
5304 		goto out_bdev;
5305 	}
5306 
5307 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5308 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5309 	set_blocksize(bdev, blocksize);
5310 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5311 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5312 		       "external journal");
5313 		goto out_bdev;
5314 	}
5315 
5316 	es = (struct ext4_super_block *) (bh->b_data + offset);
5317 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5318 	    !(le32_to_cpu(es->s_feature_incompat) &
5319 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5320 		ext4_msg(sb, KERN_ERR, "external journal has "
5321 					"bad superblock");
5322 		brelse(bh);
5323 		goto out_bdev;
5324 	}
5325 
5326 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5327 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5328 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5329 		ext4_msg(sb, KERN_ERR, "external journal has "
5330 				       "corrupt superblock");
5331 		brelse(bh);
5332 		goto out_bdev;
5333 	}
5334 
5335 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5336 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5337 		brelse(bh);
5338 		goto out_bdev;
5339 	}
5340 
5341 	len = ext4_blocks_count(es);
5342 	start = sb_block + 1;
5343 	brelse(bh);	/* we're done with the superblock */
5344 
5345 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5346 					start, len, blocksize);
5347 	if (!journal) {
5348 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5349 		goto out_bdev;
5350 	}
5351 	journal->j_private = sb;
5352 	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5353 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5354 		goto out_journal;
5355 	}
5356 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5357 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5358 					"user (unsupported) - %d",
5359 			be32_to_cpu(journal->j_superblock->s_nr_users));
5360 		goto out_journal;
5361 	}
5362 	EXT4_SB(sb)->s_journal_bdev = bdev;
5363 	ext4_init_journal_params(sb, journal);
5364 	return journal;
5365 
5366 out_journal:
5367 	jbd2_journal_destroy(journal);
5368 out_bdev:
5369 	ext4_blkdev_put(bdev);
5370 	return NULL;
5371 }
5372 
5373 static int ext4_load_journal(struct super_block *sb,
5374 			     struct ext4_super_block *es,
5375 			     unsigned long journal_devnum)
5376 {
5377 	journal_t *journal;
5378 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5379 	dev_t journal_dev;
5380 	int err = 0;
5381 	int really_read_only;
5382 	int journal_dev_ro;
5383 
5384 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5385 		return -EFSCORRUPTED;
5386 
5387 	if (journal_devnum &&
5388 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5389 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5390 			"numbers have changed");
5391 		journal_dev = new_decode_dev(journal_devnum);
5392 	} else
5393 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5394 
5395 	if (journal_inum && journal_dev) {
5396 		ext4_msg(sb, KERN_ERR,
5397 			 "filesystem has both journal inode and journal device!");
5398 		return -EINVAL;
5399 	}
5400 
5401 	if (journal_inum) {
5402 		journal = ext4_get_journal(sb, journal_inum);
5403 		if (!journal)
5404 			return -EINVAL;
5405 	} else {
5406 		journal = ext4_get_dev_journal(sb, journal_dev);
5407 		if (!journal)
5408 			return -EINVAL;
5409 	}
5410 
5411 	journal_dev_ro = bdev_read_only(journal->j_dev);
5412 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5413 
5414 	if (journal_dev_ro && !sb_rdonly(sb)) {
5415 		ext4_msg(sb, KERN_ERR,
5416 			 "journal device read-only, try mounting with '-o ro'");
5417 		err = -EROFS;
5418 		goto err_out;
5419 	}
5420 
5421 	/*
5422 	 * Are we loading a blank journal or performing recovery after a
5423 	 * crash?  For recovery, we need to check in advance whether we
5424 	 * can get read-write access to the device.
5425 	 */
5426 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5427 		if (sb_rdonly(sb)) {
5428 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5429 					"required on readonly filesystem");
5430 			if (really_read_only) {
5431 				ext4_msg(sb, KERN_ERR, "write access "
5432 					"unavailable, cannot proceed "
5433 					"(try mounting with noload)");
5434 				err = -EROFS;
5435 				goto err_out;
5436 			}
5437 			ext4_msg(sb, KERN_INFO, "write access will "
5438 			       "be enabled during recovery");
5439 		}
5440 	}
5441 
5442 	if (!(journal->j_flags & JBD2_BARRIER))
5443 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5444 
5445 	if (!ext4_has_feature_journal_needs_recovery(sb))
5446 		err = jbd2_journal_wipe(journal, !really_read_only);
5447 	if (!err) {
5448 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5449 		if (save)
5450 			memcpy(save, ((char *) es) +
5451 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5452 		err = jbd2_journal_load(journal);
5453 		if (save)
5454 			memcpy(((char *) es) + EXT4_S_ERR_START,
5455 			       save, EXT4_S_ERR_LEN);
5456 		kfree(save);
5457 	}
5458 
5459 	if (err) {
5460 		ext4_msg(sb, KERN_ERR, "error loading journal");
5461 		goto err_out;
5462 	}
5463 
5464 	EXT4_SB(sb)->s_journal = journal;
5465 	err = ext4_clear_journal_err(sb, es);
5466 	if (err) {
5467 		EXT4_SB(sb)->s_journal = NULL;
5468 		jbd2_journal_destroy(journal);
5469 		return err;
5470 	}
5471 
5472 	if (!really_read_only && journal_devnum &&
5473 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5474 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5475 
5476 		/* Make sure we flush the recovery flag to disk. */
5477 		ext4_commit_super(sb, 1);
5478 	}
5479 
5480 	return 0;
5481 
5482 err_out:
5483 	jbd2_journal_destroy(journal);
5484 	return err;
5485 }
5486 
5487 static int ext4_commit_super(struct super_block *sb, int sync)
5488 {
5489 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5490 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5491 	int error = 0;
5492 
5493 	if (!sbh || block_device_ejected(sb))
5494 		return error;
5495 
5496 	/*
5497 	 * If the file system is mounted read-only, don't update the
5498 	 * superblock write time.  This avoids updating the superblock
5499 	 * write time when we are mounting the root file system
5500 	 * read/only but we need to replay the journal; at that point,
5501 	 * for people who are east of GMT and who make their clock
5502 	 * tick in localtime for Windows bug-for-bug compatibility,
5503 	 * the clock is set in the future, and this will cause e2fsck
5504 	 * to complain and force a full file system check.
5505 	 */
5506 	if (!(sb->s_flags & SB_RDONLY))
5507 		ext4_update_tstamp(es, s_wtime);
5508 	if (sb->s_bdev->bd_part)
5509 		es->s_kbytes_written =
5510 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5511 			    ((part_stat_read(sb->s_bdev->bd_part,
5512 					     sectors[STAT_WRITE]) -
5513 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5514 	else
5515 		es->s_kbytes_written =
5516 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5517 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5518 		ext4_free_blocks_count_set(es,
5519 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5520 				&EXT4_SB(sb)->s_freeclusters_counter)));
5521 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5522 		es->s_free_inodes_count =
5523 			cpu_to_le32(percpu_counter_sum_positive(
5524 				&EXT4_SB(sb)->s_freeinodes_counter));
5525 	BUFFER_TRACE(sbh, "marking dirty");
5526 	ext4_superblock_csum_set(sb);
5527 	if (sync)
5528 		lock_buffer(sbh);
5529 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5530 		/*
5531 		 * Oh, dear.  A previous attempt to write the
5532 		 * superblock failed.  This could happen because the
5533 		 * USB device was yanked out.  Or it could happen to
5534 		 * be a transient write error and maybe the block will
5535 		 * be remapped.  Nothing we can do but to retry the
5536 		 * write and hope for the best.
5537 		 */
5538 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5539 		       "superblock detected");
5540 		clear_buffer_write_io_error(sbh);
5541 		set_buffer_uptodate(sbh);
5542 	}
5543 	mark_buffer_dirty(sbh);
5544 	if (sync) {
5545 		unlock_buffer(sbh);
5546 		error = __sync_dirty_buffer(sbh,
5547 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5548 		if (buffer_write_io_error(sbh)) {
5549 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5550 			       "superblock");
5551 			clear_buffer_write_io_error(sbh);
5552 			set_buffer_uptodate(sbh);
5553 		}
5554 	}
5555 	return error;
5556 }
5557 
5558 /*
5559  * Have we just finished recovery?  If so, and if we are mounting (or
5560  * remounting) the filesystem readonly, then we will end up with a
5561  * consistent fs on disk.  Record that fact.
5562  */
5563 static int ext4_mark_recovery_complete(struct super_block *sb,
5564 				       struct ext4_super_block *es)
5565 {
5566 	int err;
5567 	journal_t *journal = EXT4_SB(sb)->s_journal;
5568 
5569 	if (!ext4_has_feature_journal(sb)) {
5570 		if (journal != NULL) {
5571 			ext4_error(sb, "Journal got removed while the fs was "
5572 				   "mounted!");
5573 			return -EFSCORRUPTED;
5574 		}
5575 		return 0;
5576 	}
5577 	jbd2_journal_lock_updates(journal);
5578 	err = jbd2_journal_flush(journal);
5579 	if (err < 0)
5580 		goto out;
5581 
5582 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5583 		ext4_clear_feature_journal_needs_recovery(sb);
5584 		ext4_commit_super(sb, 1);
5585 	}
5586 out:
5587 	jbd2_journal_unlock_updates(journal);
5588 	return err;
5589 }
5590 
5591 /*
5592  * If we are mounting (or read-write remounting) a filesystem whose journal
5593  * has recorded an error from a previous lifetime, move that error to the
5594  * main filesystem now.
5595  */
5596 static int ext4_clear_journal_err(struct super_block *sb,
5597 				   struct ext4_super_block *es)
5598 {
5599 	journal_t *journal;
5600 	int j_errno;
5601 	const char *errstr;
5602 
5603 	if (!ext4_has_feature_journal(sb)) {
5604 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5605 		return -EFSCORRUPTED;
5606 	}
5607 
5608 	journal = EXT4_SB(sb)->s_journal;
5609 
5610 	/*
5611 	 * Now check for any error status which may have been recorded in the
5612 	 * journal by a prior ext4_error() or ext4_abort()
5613 	 */
5614 
5615 	j_errno = jbd2_journal_errno(journal);
5616 	if (j_errno) {
5617 		char nbuf[16];
5618 
5619 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5620 		ext4_warning(sb, "Filesystem error recorded "
5621 			     "from previous mount: %s", errstr);
5622 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5623 
5624 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5625 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5626 		ext4_commit_super(sb, 1);
5627 
5628 		jbd2_journal_clear_err(journal);
5629 		jbd2_journal_update_sb_errno(journal);
5630 	}
5631 	return 0;
5632 }
5633 
5634 /*
5635  * Force the running and committing transactions to commit,
5636  * and wait on the commit.
5637  */
5638 int ext4_force_commit(struct super_block *sb)
5639 {
5640 	journal_t *journal;
5641 
5642 	if (sb_rdonly(sb))
5643 		return 0;
5644 
5645 	journal = EXT4_SB(sb)->s_journal;
5646 	return ext4_journal_force_commit(journal);
5647 }
5648 
5649 static int ext4_sync_fs(struct super_block *sb, int wait)
5650 {
5651 	int ret = 0;
5652 	tid_t target;
5653 	bool needs_barrier = false;
5654 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5655 
5656 	if (unlikely(ext4_forced_shutdown(sbi)))
5657 		return 0;
5658 
5659 	trace_ext4_sync_fs(sb, wait);
5660 	flush_workqueue(sbi->rsv_conversion_wq);
5661 	/*
5662 	 * Writeback quota in non-journalled quota case - journalled quota has
5663 	 * no dirty dquots
5664 	 */
5665 	dquot_writeback_dquots(sb, -1);
5666 	/*
5667 	 * Data writeback is possible w/o journal transaction, so barrier must
5668 	 * being sent at the end of the function. But we can skip it if
5669 	 * transaction_commit will do it for us.
5670 	 */
5671 	if (sbi->s_journal) {
5672 		target = jbd2_get_latest_transaction(sbi->s_journal);
5673 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5674 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5675 			needs_barrier = true;
5676 
5677 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5678 			if (wait)
5679 				ret = jbd2_log_wait_commit(sbi->s_journal,
5680 							   target);
5681 		}
5682 	} else if (wait && test_opt(sb, BARRIER))
5683 		needs_barrier = true;
5684 	if (needs_barrier) {
5685 		int err;
5686 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL);
5687 		if (!ret)
5688 			ret = err;
5689 	}
5690 
5691 	return ret;
5692 }
5693 
5694 /*
5695  * LVM calls this function before a (read-only) snapshot is created.  This
5696  * gives us a chance to flush the journal completely and mark the fs clean.
5697  *
5698  * Note that only this function cannot bring a filesystem to be in a clean
5699  * state independently. It relies on upper layer to stop all data & metadata
5700  * modifications.
5701  */
5702 static int ext4_freeze(struct super_block *sb)
5703 {
5704 	int error = 0;
5705 	journal_t *journal;
5706 
5707 	if (sb_rdonly(sb))
5708 		return 0;
5709 
5710 	journal = EXT4_SB(sb)->s_journal;
5711 
5712 	if (journal) {
5713 		/* Now we set up the journal barrier. */
5714 		jbd2_journal_lock_updates(journal);
5715 
5716 		/*
5717 		 * Don't clear the needs_recovery flag if we failed to
5718 		 * flush the journal.
5719 		 */
5720 		error = jbd2_journal_flush(journal);
5721 		if (error < 0)
5722 			goto out;
5723 
5724 		/* Journal blocked and flushed, clear needs_recovery flag. */
5725 		ext4_clear_feature_journal_needs_recovery(sb);
5726 	}
5727 
5728 	error = ext4_commit_super(sb, 1);
5729 out:
5730 	if (journal)
5731 		/* we rely on upper layer to stop further updates */
5732 		jbd2_journal_unlock_updates(journal);
5733 	return error;
5734 }
5735 
5736 /*
5737  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5738  * flag here, even though the filesystem is not technically dirty yet.
5739  */
5740 static int ext4_unfreeze(struct super_block *sb)
5741 {
5742 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5743 		return 0;
5744 
5745 	if (EXT4_SB(sb)->s_journal) {
5746 		/* Reset the needs_recovery flag before the fs is unlocked. */
5747 		ext4_set_feature_journal_needs_recovery(sb);
5748 	}
5749 
5750 	ext4_commit_super(sb, 1);
5751 	return 0;
5752 }
5753 
5754 /*
5755  * Structure to save mount options for ext4_remount's benefit
5756  */
5757 struct ext4_mount_options {
5758 	unsigned long s_mount_opt;
5759 	unsigned long s_mount_opt2;
5760 	kuid_t s_resuid;
5761 	kgid_t s_resgid;
5762 	unsigned long s_commit_interval;
5763 	u32 s_min_batch_time, s_max_batch_time;
5764 #ifdef CONFIG_QUOTA
5765 	int s_jquota_fmt;
5766 	char *s_qf_names[EXT4_MAXQUOTAS];
5767 #endif
5768 };
5769 
5770 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5771 {
5772 	struct ext4_super_block *es;
5773 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5774 	unsigned long old_sb_flags, vfs_flags;
5775 	struct ext4_mount_options old_opts;
5776 	int enable_quota = 0;
5777 	ext4_group_t g;
5778 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5779 	int err = 0;
5780 #ifdef CONFIG_QUOTA
5781 	int i, j;
5782 	char *to_free[EXT4_MAXQUOTAS];
5783 #endif
5784 	char *orig_data = kstrdup(data, GFP_KERNEL);
5785 
5786 	if (data && !orig_data)
5787 		return -ENOMEM;
5788 
5789 	/* Store the original options */
5790 	old_sb_flags = sb->s_flags;
5791 	old_opts.s_mount_opt = sbi->s_mount_opt;
5792 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5793 	old_opts.s_resuid = sbi->s_resuid;
5794 	old_opts.s_resgid = sbi->s_resgid;
5795 	old_opts.s_commit_interval = sbi->s_commit_interval;
5796 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5797 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5798 #ifdef CONFIG_QUOTA
5799 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5800 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5801 		if (sbi->s_qf_names[i]) {
5802 			char *qf_name = get_qf_name(sb, sbi, i);
5803 
5804 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5805 			if (!old_opts.s_qf_names[i]) {
5806 				for (j = 0; j < i; j++)
5807 					kfree(old_opts.s_qf_names[j]);
5808 				kfree(orig_data);
5809 				return -ENOMEM;
5810 			}
5811 		} else
5812 			old_opts.s_qf_names[i] = NULL;
5813 #endif
5814 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5815 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5816 
5817 	/*
5818 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5819 	 * either way we need to make sure it matches in both *flags and
5820 	 * s_flags. Copy those selected flags from *flags to s_flags
5821 	 */
5822 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5823 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5824 
5825 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5826 		err = -EINVAL;
5827 		goto restore_opts;
5828 	}
5829 
5830 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5831 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5832 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5833 			 "during remount not supported; ignoring");
5834 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5835 	}
5836 
5837 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5838 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5839 			ext4_msg(sb, KERN_ERR, "can't mount with "
5840 				 "both data=journal and delalloc");
5841 			err = -EINVAL;
5842 			goto restore_opts;
5843 		}
5844 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5845 			ext4_msg(sb, KERN_ERR, "can't mount with "
5846 				 "both data=journal and dioread_nolock");
5847 			err = -EINVAL;
5848 			goto restore_opts;
5849 		}
5850 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5851 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5852 			ext4_msg(sb, KERN_ERR, "can't mount with "
5853 				"journal_async_commit in data=ordered mode");
5854 			err = -EINVAL;
5855 			goto restore_opts;
5856 		}
5857 	}
5858 
5859 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5860 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5861 		err = -EINVAL;
5862 		goto restore_opts;
5863 	}
5864 
5865 	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5866 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5867 
5868 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5869 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5870 
5871 	es = sbi->s_es;
5872 
5873 	if (sbi->s_journal) {
5874 		ext4_init_journal_params(sb, sbi->s_journal);
5875 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5876 	}
5877 
5878 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5879 		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
5880 			err = -EROFS;
5881 			goto restore_opts;
5882 		}
5883 
5884 		if (*flags & SB_RDONLY) {
5885 			err = sync_filesystem(sb);
5886 			if (err < 0)
5887 				goto restore_opts;
5888 			err = dquot_suspend(sb, -1);
5889 			if (err < 0)
5890 				goto restore_opts;
5891 
5892 			/*
5893 			 * First of all, the unconditional stuff we have to do
5894 			 * to disable replay of the journal when we next remount
5895 			 */
5896 			sb->s_flags |= SB_RDONLY;
5897 
5898 			/*
5899 			 * OK, test if we are remounting a valid rw partition
5900 			 * readonly, and if so set the rdonly flag and then
5901 			 * mark the partition as valid again.
5902 			 */
5903 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5904 			    (sbi->s_mount_state & EXT4_VALID_FS))
5905 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5906 
5907 			if (sbi->s_journal) {
5908 				/*
5909 				 * We let remount-ro finish even if marking fs
5910 				 * as clean failed...
5911 				 */
5912 				ext4_mark_recovery_complete(sb, es);
5913 			}
5914 			if (sbi->s_mmp_tsk)
5915 				kthread_stop(sbi->s_mmp_tsk);
5916 		} else {
5917 			/* Make sure we can mount this feature set readwrite */
5918 			if (ext4_has_feature_readonly(sb) ||
5919 			    !ext4_feature_set_ok(sb, 0)) {
5920 				err = -EROFS;
5921 				goto restore_opts;
5922 			}
5923 			/*
5924 			 * Make sure the group descriptor checksums
5925 			 * are sane.  If they aren't, refuse to remount r/w.
5926 			 */
5927 			for (g = 0; g < sbi->s_groups_count; g++) {
5928 				struct ext4_group_desc *gdp =
5929 					ext4_get_group_desc(sb, g, NULL);
5930 
5931 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5932 					ext4_msg(sb, KERN_ERR,
5933 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5934 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5935 					       le16_to_cpu(gdp->bg_checksum));
5936 					err = -EFSBADCRC;
5937 					goto restore_opts;
5938 				}
5939 			}
5940 
5941 			/*
5942 			 * If we have an unprocessed orphan list hanging
5943 			 * around from a previously readonly bdev mount,
5944 			 * require a full umount/remount for now.
5945 			 */
5946 			if (es->s_last_orphan) {
5947 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5948 				       "remount RDWR because of unprocessed "
5949 				       "orphan inode list.  Please "
5950 				       "umount/remount instead");
5951 				err = -EINVAL;
5952 				goto restore_opts;
5953 			}
5954 
5955 			/*
5956 			 * Mounting a RDONLY partition read-write, so reread
5957 			 * and store the current valid flag.  (It may have
5958 			 * been changed by e2fsck since we originally mounted
5959 			 * the partition.)
5960 			 */
5961 			if (sbi->s_journal) {
5962 				err = ext4_clear_journal_err(sb, es);
5963 				if (err)
5964 					goto restore_opts;
5965 			}
5966 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5967 
5968 			err = ext4_setup_super(sb, es, 0);
5969 			if (err)
5970 				goto restore_opts;
5971 
5972 			sb->s_flags &= ~SB_RDONLY;
5973 			if (ext4_has_feature_mmp(sb))
5974 				if (ext4_multi_mount_protect(sb,
5975 						le64_to_cpu(es->s_mmp_block))) {
5976 					err = -EROFS;
5977 					goto restore_opts;
5978 				}
5979 			enable_quota = 1;
5980 		}
5981 	}
5982 
5983 	/*
5984 	 * Reinitialize lazy itable initialization thread based on
5985 	 * current settings
5986 	 */
5987 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5988 		ext4_unregister_li_request(sb);
5989 	else {
5990 		ext4_group_t first_not_zeroed;
5991 		first_not_zeroed = ext4_has_uninit_itable(sb);
5992 		ext4_register_li_request(sb, first_not_zeroed);
5993 	}
5994 
5995 	/*
5996 	 * Handle creation of system zone data early because it can fail.
5997 	 * Releasing of existing data is done when we are sure remount will
5998 	 * succeed.
5999 	 */
6000 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6001 		err = ext4_setup_system_zone(sb);
6002 		if (err)
6003 			goto restore_opts;
6004 	}
6005 
6006 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6007 		err = ext4_commit_super(sb, 1);
6008 		if (err)
6009 			goto restore_opts;
6010 	}
6011 
6012 #ifdef CONFIG_QUOTA
6013 	/* Release old quota file names */
6014 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6015 		kfree(old_opts.s_qf_names[i]);
6016 	if (enable_quota) {
6017 		if (sb_any_quota_suspended(sb))
6018 			dquot_resume(sb, -1);
6019 		else if (ext4_has_feature_quota(sb)) {
6020 			err = ext4_enable_quotas(sb);
6021 			if (err)
6022 				goto restore_opts;
6023 		}
6024 	}
6025 #endif
6026 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6027 		ext4_release_system_zone(sb);
6028 
6029 	/*
6030 	 * Some options can be enabled by ext4 and/or by VFS mount flag
6031 	 * either way we need to make sure it matches in both *flags and
6032 	 * s_flags. Copy those selected flags from s_flags to *flags
6033 	 */
6034 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6035 
6036 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
6037 	kfree(orig_data);
6038 	return 0;
6039 
6040 restore_opts:
6041 	sb->s_flags = old_sb_flags;
6042 	sbi->s_mount_opt = old_opts.s_mount_opt;
6043 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6044 	sbi->s_resuid = old_opts.s_resuid;
6045 	sbi->s_resgid = old_opts.s_resgid;
6046 	sbi->s_commit_interval = old_opts.s_commit_interval;
6047 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
6048 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
6049 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6050 		ext4_release_system_zone(sb);
6051 #ifdef CONFIG_QUOTA
6052 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6053 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6054 		to_free[i] = get_qf_name(sb, sbi, i);
6055 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6056 	}
6057 	synchronize_rcu();
6058 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
6059 		kfree(to_free[i]);
6060 #endif
6061 	kfree(orig_data);
6062 	return err;
6063 }
6064 
6065 #ifdef CONFIG_QUOTA
6066 static int ext4_statfs_project(struct super_block *sb,
6067 			       kprojid_t projid, struct kstatfs *buf)
6068 {
6069 	struct kqid qid;
6070 	struct dquot *dquot;
6071 	u64 limit;
6072 	u64 curblock;
6073 
6074 	qid = make_kqid_projid(projid);
6075 	dquot = dqget(sb, qid);
6076 	if (IS_ERR(dquot))
6077 		return PTR_ERR(dquot);
6078 	spin_lock(&dquot->dq_dqb_lock);
6079 
6080 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6081 			     dquot->dq_dqb.dqb_bhardlimit);
6082 	limit >>= sb->s_blocksize_bits;
6083 
6084 	if (limit && buf->f_blocks > limit) {
6085 		curblock = (dquot->dq_dqb.dqb_curspace +
6086 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6087 		buf->f_blocks = limit;
6088 		buf->f_bfree = buf->f_bavail =
6089 			(buf->f_blocks > curblock) ?
6090 			 (buf->f_blocks - curblock) : 0;
6091 	}
6092 
6093 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6094 			     dquot->dq_dqb.dqb_ihardlimit);
6095 	if (limit && buf->f_files > limit) {
6096 		buf->f_files = limit;
6097 		buf->f_ffree =
6098 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6099 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6100 	}
6101 
6102 	spin_unlock(&dquot->dq_dqb_lock);
6103 	dqput(dquot);
6104 	return 0;
6105 }
6106 #endif
6107 
6108 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6109 {
6110 	struct super_block *sb = dentry->d_sb;
6111 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6112 	struct ext4_super_block *es = sbi->s_es;
6113 	ext4_fsblk_t overhead = 0, resv_blocks;
6114 	u64 fsid;
6115 	s64 bfree;
6116 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6117 
6118 	if (!test_opt(sb, MINIX_DF))
6119 		overhead = sbi->s_overhead;
6120 
6121 	buf->f_type = EXT4_SUPER_MAGIC;
6122 	buf->f_bsize = sb->s_blocksize;
6123 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6124 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6125 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6126 	/* prevent underflow in case that few free space is available */
6127 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6128 	buf->f_bavail = buf->f_bfree -
6129 			(ext4_r_blocks_count(es) + resv_blocks);
6130 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6131 		buf->f_bavail = 0;
6132 	buf->f_files = le32_to_cpu(es->s_inodes_count);
6133 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6134 	buf->f_namelen = EXT4_NAME_LEN;
6135 	fsid = le64_to_cpup((void *)es->s_uuid) ^
6136 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
6137 	buf->f_fsid = u64_to_fsid(fsid);
6138 
6139 #ifdef CONFIG_QUOTA
6140 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6141 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
6142 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6143 #endif
6144 	return 0;
6145 }
6146 
6147 
6148 #ifdef CONFIG_QUOTA
6149 
6150 /*
6151  * Helper functions so that transaction is started before we acquire dqio_sem
6152  * to keep correct lock ordering of transaction > dqio_sem
6153  */
6154 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6155 {
6156 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6157 }
6158 
6159 static int ext4_write_dquot(struct dquot *dquot)
6160 {
6161 	int ret, err;
6162 	handle_t *handle;
6163 	struct inode *inode;
6164 
6165 	inode = dquot_to_inode(dquot);
6166 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6167 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6168 	if (IS_ERR(handle))
6169 		return PTR_ERR(handle);
6170 	ret = dquot_commit(dquot);
6171 	err = ext4_journal_stop(handle);
6172 	if (!ret)
6173 		ret = err;
6174 	return ret;
6175 }
6176 
6177 static int ext4_acquire_dquot(struct dquot *dquot)
6178 {
6179 	int ret, err;
6180 	handle_t *handle;
6181 
6182 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6183 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6184 	if (IS_ERR(handle))
6185 		return PTR_ERR(handle);
6186 	ret = dquot_acquire(dquot);
6187 	err = ext4_journal_stop(handle);
6188 	if (!ret)
6189 		ret = err;
6190 	return ret;
6191 }
6192 
6193 static int ext4_release_dquot(struct dquot *dquot)
6194 {
6195 	int ret, err;
6196 	handle_t *handle;
6197 
6198 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6199 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6200 	if (IS_ERR(handle)) {
6201 		/* Release dquot anyway to avoid endless cycle in dqput() */
6202 		dquot_release(dquot);
6203 		return PTR_ERR(handle);
6204 	}
6205 	ret = dquot_release(dquot);
6206 	err = ext4_journal_stop(handle);
6207 	if (!ret)
6208 		ret = err;
6209 	return ret;
6210 }
6211 
6212 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6213 {
6214 	struct super_block *sb = dquot->dq_sb;
6215 	struct ext4_sb_info *sbi = EXT4_SB(sb);
6216 
6217 	/* Are we journaling quotas? */
6218 	if (ext4_has_feature_quota(sb) ||
6219 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
6220 		dquot_mark_dquot_dirty(dquot);
6221 		return ext4_write_dquot(dquot);
6222 	} else {
6223 		return dquot_mark_dquot_dirty(dquot);
6224 	}
6225 }
6226 
6227 static int ext4_write_info(struct super_block *sb, int type)
6228 {
6229 	int ret, err;
6230 	handle_t *handle;
6231 
6232 	/* Data block + inode block */
6233 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6234 	if (IS_ERR(handle))
6235 		return PTR_ERR(handle);
6236 	ret = dquot_commit_info(sb, type);
6237 	err = ext4_journal_stop(handle);
6238 	if (!ret)
6239 		ret = err;
6240 	return ret;
6241 }
6242 
6243 /*
6244  * Turn on quotas during mount time - we need to find
6245  * the quota file and such...
6246  */
6247 static int ext4_quota_on_mount(struct super_block *sb, int type)
6248 {
6249 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6250 					EXT4_SB(sb)->s_jquota_fmt, type);
6251 }
6252 
6253 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6254 {
6255 	struct ext4_inode_info *ei = EXT4_I(inode);
6256 
6257 	/* The first argument of lockdep_set_subclass has to be
6258 	 * *exactly* the same as the argument to init_rwsem() --- in
6259 	 * this case, in init_once() --- or lockdep gets unhappy
6260 	 * because the name of the lock is set using the
6261 	 * stringification of the argument to init_rwsem().
6262 	 */
6263 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6264 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6265 }
6266 
6267 /*
6268  * Standard function to be called on quota_on
6269  */
6270 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6271 			 const struct path *path)
6272 {
6273 	int err;
6274 
6275 	if (!test_opt(sb, QUOTA))
6276 		return -EINVAL;
6277 
6278 	/* Quotafile not on the same filesystem? */
6279 	if (path->dentry->d_sb != sb)
6280 		return -EXDEV;
6281 
6282 	/* Quota already enabled for this file? */
6283 	if (IS_NOQUOTA(d_inode(path->dentry)))
6284 		return -EBUSY;
6285 
6286 	/* Journaling quota? */
6287 	if (EXT4_SB(sb)->s_qf_names[type]) {
6288 		/* Quotafile not in fs root? */
6289 		if (path->dentry->d_parent != sb->s_root)
6290 			ext4_msg(sb, KERN_WARNING,
6291 				"Quota file not on filesystem root. "
6292 				"Journaled quota will not work");
6293 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6294 	} else {
6295 		/*
6296 		 * Clear the flag just in case mount options changed since
6297 		 * last time.
6298 		 */
6299 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6300 	}
6301 
6302 	/*
6303 	 * When we journal data on quota file, we have to flush journal to see
6304 	 * all updates to the file when we bypass pagecache...
6305 	 */
6306 	if (EXT4_SB(sb)->s_journal &&
6307 	    ext4_should_journal_data(d_inode(path->dentry))) {
6308 		/*
6309 		 * We don't need to lock updates but journal_flush() could
6310 		 * otherwise be livelocked...
6311 		 */
6312 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6313 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
6314 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6315 		if (err)
6316 			return err;
6317 	}
6318 
6319 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6320 	err = dquot_quota_on(sb, type, format_id, path);
6321 	if (err) {
6322 		lockdep_set_quota_inode(path->dentry->d_inode,
6323 					     I_DATA_SEM_NORMAL);
6324 	} else {
6325 		struct inode *inode = d_inode(path->dentry);
6326 		handle_t *handle;
6327 
6328 		/*
6329 		 * Set inode flags to prevent userspace from messing with quota
6330 		 * files. If this fails, we return success anyway since quotas
6331 		 * are already enabled and this is not a hard failure.
6332 		 */
6333 		inode_lock(inode);
6334 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6335 		if (IS_ERR(handle))
6336 			goto unlock_inode;
6337 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6338 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6339 				S_NOATIME | S_IMMUTABLE);
6340 		err = ext4_mark_inode_dirty(handle, inode);
6341 		ext4_journal_stop(handle);
6342 	unlock_inode:
6343 		inode_unlock(inode);
6344 	}
6345 	return err;
6346 }
6347 
6348 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6349 			     unsigned int flags)
6350 {
6351 	int err;
6352 	struct inode *qf_inode;
6353 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6354 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6355 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6356 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6357 	};
6358 
6359 	BUG_ON(!ext4_has_feature_quota(sb));
6360 
6361 	if (!qf_inums[type])
6362 		return -EPERM;
6363 
6364 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6365 	if (IS_ERR(qf_inode)) {
6366 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6367 		return PTR_ERR(qf_inode);
6368 	}
6369 
6370 	/* Don't account quota for quota files to avoid recursion */
6371 	qf_inode->i_flags |= S_NOQUOTA;
6372 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6373 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6374 	if (err)
6375 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6376 	iput(qf_inode);
6377 
6378 	return err;
6379 }
6380 
6381 /* Enable usage tracking for all quota types. */
6382 static int ext4_enable_quotas(struct super_block *sb)
6383 {
6384 	int type, err = 0;
6385 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6386 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6387 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6388 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6389 	};
6390 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6391 		test_opt(sb, USRQUOTA),
6392 		test_opt(sb, GRPQUOTA),
6393 		test_opt(sb, PRJQUOTA),
6394 	};
6395 
6396 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6397 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6398 		if (qf_inums[type]) {
6399 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6400 				DQUOT_USAGE_ENABLED |
6401 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6402 			if (err) {
6403 				ext4_warning(sb,
6404 					"Failed to enable quota tracking "
6405 					"(type=%d, err=%d). Please run "
6406 					"e2fsck to fix.", type, err);
6407 				for (type--; type >= 0; type--)
6408 					dquot_quota_off(sb, type);
6409 
6410 				return err;
6411 			}
6412 		}
6413 	}
6414 	return 0;
6415 }
6416 
6417 static int ext4_quota_off(struct super_block *sb, int type)
6418 {
6419 	struct inode *inode = sb_dqopt(sb)->files[type];
6420 	handle_t *handle;
6421 	int err;
6422 
6423 	/* Force all delayed allocation blocks to be allocated.
6424 	 * Caller already holds s_umount sem */
6425 	if (test_opt(sb, DELALLOC))
6426 		sync_filesystem(sb);
6427 
6428 	if (!inode || !igrab(inode))
6429 		goto out;
6430 
6431 	err = dquot_quota_off(sb, type);
6432 	if (err || ext4_has_feature_quota(sb))
6433 		goto out_put;
6434 
6435 	inode_lock(inode);
6436 	/*
6437 	 * Update modification times of quota files when userspace can
6438 	 * start looking at them. If we fail, we return success anyway since
6439 	 * this is not a hard failure and quotas are already disabled.
6440 	 */
6441 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6442 	if (IS_ERR(handle)) {
6443 		err = PTR_ERR(handle);
6444 		goto out_unlock;
6445 	}
6446 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6447 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6448 	inode->i_mtime = inode->i_ctime = current_time(inode);
6449 	err = ext4_mark_inode_dirty(handle, inode);
6450 	ext4_journal_stop(handle);
6451 out_unlock:
6452 	inode_unlock(inode);
6453 out_put:
6454 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6455 	iput(inode);
6456 	return err;
6457 out:
6458 	return dquot_quota_off(sb, type);
6459 }
6460 
6461 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6462  * acquiring the locks... As quota files are never truncated and quota code
6463  * itself serializes the operations (and no one else should touch the files)
6464  * we don't have to be afraid of races */
6465 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6466 			       size_t len, loff_t off)
6467 {
6468 	struct inode *inode = sb_dqopt(sb)->files[type];
6469 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6470 	int offset = off & (sb->s_blocksize - 1);
6471 	int tocopy;
6472 	size_t toread;
6473 	struct buffer_head *bh;
6474 	loff_t i_size = i_size_read(inode);
6475 
6476 	if (off > i_size)
6477 		return 0;
6478 	if (off+len > i_size)
6479 		len = i_size-off;
6480 	toread = len;
6481 	while (toread > 0) {
6482 		tocopy = sb->s_blocksize - offset < toread ?
6483 				sb->s_blocksize - offset : toread;
6484 		bh = ext4_bread(NULL, inode, blk, 0);
6485 		if (IS_ERR(bh))
6486 			return PTR_ERR(bh);
6487 		if (!bh)	/* A hole? */
6488 			memset(data, 0, tocopy);
6489 		else
6490 			memcpy(data, bh->b_data+offset, tocopy);
6491 		brelse(bh);
6492 		offset = 0;
6493 		toread -= tocopy;
6494 		data += tocopy;
6495 		blk++;
6496 	}
6497 	return len;
6498 }
6499 
6500 /* Write to quotafile (we know the transaction is already started and has
6501  * enough credits) */
6502 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6503 				const char *data, size_t len, loff_t off)
6504 {
6505 	struct inode *inode = sb_dqopt(sb)->files[type];
6506 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6507 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6508 	int retries = 0;
6509 	struct buffer_head *bh;
6510 	handle_t *handle = journal_current_handle();
6511 
6512 	if (EXT4_SB(sb)->s_journal && !handle) {
6513 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6514 			" cancelled because transaction is not started",
6515 			(unsigned long long)off, (unsigned long long)len);
6516 		return -EIO;
6517 	}
6518 	/*
6519 	 * Since we account only one data block in transaction credits,
6520 	 * then it is impossible to cross a block boundary.
6521 	 */
6522 	if (sb->s_blocksize - offset < len) {
6523 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6524 			" cancelled because not block aligned",
6525 			(unsigned long long)off, (unsigned long long)len);
6526 		return -EIO;
6527 	}
6528 
6529 	do {
6530 		bh = ext4_bread(handle, inode, blk,
6531 				EXT4_GET_BLOCKS_CREATE |
6532 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6533 	} while (PTR_ERR(bh) == -ENOSPC &&
6534 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6535 	if (IS_ERR(bh))
6536 		return PTR_ERR(bh);
6537 	if (!bh)
6538 		goto out;
6539 	BUFFER_TRACE(bh, "get write access");
6540 	err = ext4_journal_get_write_access(handle, bh);
6541 	if (err) {
6542 		brelse(bh);
6543 		return err;
6544 	}
6545 	lock_buffer(bh);
6546 	memcpy(bh->b_data+offset, data, len);
6547 	flush_dcache_page(bh->b_page);
6548 	unlock_buffer(bh);
6549 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6550 	brelse(bh);
6551 out:
6552 	if (inode->i_size < off + len) {
6553 		i_size_write(inode, off + len);
6554 		EXT4_I(inode)->i_disksize = inode->i_size;
6555 		err2 = ext4_mark_inode_dirty(handle, inode);
6556 		if (unlikely(err2 && !err))
6557 			err = err2;
6558 	}
6559 	return err ? err : len;
6560 }
6561 #endif
6562 
6563 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6564 		       const char *dev_name, void *data)
6565 {
6566 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6567 }
6568 
6569 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6570 static inline void register_as_ext2(void)
6571 {
6572 	int err = register_filesystem(&ext2_fs_type);
6573 	if (err)
6574 		printk(KERN_WARNING
6575 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6576 }
6577 
6578 static inline void unregister_as_ext2(void)
6579 {
6580 	unregister_filesystem(&ext2_fs_type);
6581 }
6582 
6583 static inline int ext2_feature_set_ok(struct super_block *sb)
6584 {
6585 	if (ext4_has_unknown_ext2_incompat_features(sb))
6586 		return 0;
6587 	if (sb_rdonly(sb))
6588 		return 1;
6589 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6590 		return 0;
6591 	return 1;
6592 }
6593 #else
6594 static inline void register_as_ext2(void) { }
6595 static inline void unregister_as_ext2(void) { }
6596 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6597 #endif
6598 
6599 static inline void register_as_ext3(void)
6600 {
6601 	int err = register_filesystem(&ext3_fs_type);
6602 	if (err)
6603 		printk(KERN_WARNING
6604 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6605 }
6606 
6607 static inline void unregister_as_ext3(void)
6608 {
6609 	unregister_filesystem(&ext3_fs_type);
6610 }
6611 
6612 static inline int ext3_feature_set_ok(struct super_block *sb)
6613 {
6614 	if (ext4_has_unknown_ext3_incompat_features(sb))
6615 		return 0;
6616 	if (!ext4_has_feature_journal(sb))
6617 		return 0;
6618 	if (sb_rdonly(sb))
6619 		return 1;
6620 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6621 		return 0;
6622 	return 1;
6623 }
6624 
6625 static struct file_system_type ext4_fs_type = {
6626 	.owner		= THIS_MODULE,
6627 	.name		= "ext4",
6628 	.mount		= ext4_mount,
6629 	.kill_sb	= kill_block_super,
6630 	.fs_flags	= FS_REQUIRES_DEV,
6631 };
6632 MODULE_ALIAS_FS("ext4");
6633 
6634 /* Shared across all ext4 file systems */
6635 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6636 
6637 static int __init ext4_init_fs(void)
6638 {
6639 	int i, err;
6640 
6641 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6642 	ext4_li_info = NULL;
6643 	mutex_init(&ext4_li_mtx);
6644 
6645 	/* Build-time check for flags consistency */
6646 	ext4_check_flag_values();
6647 
6648 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6649 		init_waitqueue_head(&ext4__ioend_wq[i]);
6650 
6651 	err = ext4_init_es();
6652 	if (err)
6653 		return err;
6654 
6655 	err = ext4_init_pending();
6656 	if (err)
6657 		goto out7;
6658 
6659 	err = ext4_init_post_read_processing();
6660 	if (err)
6661 		goto out6;
6662 
6663 	err = ext4_init_pageio();
6664 	if (err)
6665 		goto out5;
6666 
6667 	err = ext4_init_system_zone();
6668 	if (err)
6669 		goto out4;
6670 
6671 	err = ext4_init_sysfs();
6672 	if (err)
6673 		goto out3;
6674 
6675 	err = ext4_init_mballoc();
6676 	if (err)
6677 		goto out2;
6678 	err = init_inodecache();
6679 	if (err)
6680 		goto out1;
6681 
6682 	err = ext4_fc_init_dentry_cache();
6683 	if (err)
6684 		goto out05;
6685 
6686 	register_as_ext3();
6687 	register_as_ext2();
6688 	err = register_filesystem(&ext4_fs_type);
6689 	if (err)
6690 		goto out;
6691 
6692 	return 0;
6693 out:
6694 	unregister_as_ext2();
6695 	unregister_as_ext3();
6696 out05:
6697 	destroy_inodecache();
6698 out1:
6699 	ext4_exit_mballoc();
6700 out2:
6701 	ext4_exit_sysfs();
6702 out3:
6703 	ext4_exit_system_zone();
6704 out4:
6705 	ext4_exit_pageio();
6706 out5:
6707 	ext4_exit_post_read_processing();
6708 out6:
6709 	ext4_exit_pending();
6710 out7:
6711 	ext4_exit_es();
6712 
6713 	return err;
6714 }
6715 
6716 static void __exit ext4_exit_fs(void)
6717 {
6718 	ext4_destroy_lazyinit_thread();
6719 	unregister_as_ext2();
6720 	unregister_as_ext3();
6721 	unregister_filesystem(&ext4_fs_type);
6722 	destroy_inodecache();
6723 	ext4_exit_mballoc();
6724 	ext4_exit_sysfs();
6725 	ext4_exit_system_zone();
6726 	ext4_exit_pageio();
6727 	ext4_exit_post_read_processing();
6728 	ext4_exit_es();
6729 	ext4_exit_pending();
6730 }
6731 
6732 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6733 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6734 MODULE_LICENSE("GPL");
6735 MODULE_SOFTDEP("pre: crc32c");
6736 module_init(ext4_init_fs)
6737 module_exit(ext4_exit_fs)
6738