xref: /openbmc/linux/fs/ext4/super.c (revision dfc53baa)
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  * This works like sb_bread() except it uses ERR_PTR for error
146  * returns.  Currently with sb_bread it's impossible to distinguish
147  * between ENOMEM and EIO situations (since both result in a NULL
148  * return.
149  */
150 struct buffer_head *
151 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
152 {
153 	struct buffer_head *bh = sb_getblk(sb, block);
154 
155 	if (bh == NULL)
156 		return ERR_PTR(-ENOMEM);
157 	if (ext4_buffer_uptodate(bh))
158 		return bh;
159 	ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
160 	wait_on_buffer(bh);
161 	if (buffer_uptodate(bh))
162 		return bh;
163 	put_bh(bh);
164 	return ERR_PTR(-EIO);
165 }
166 
167 static int ext4_verify_csum_type(struct super_block *sb,
168 				 struct ext4_super_block *es)
169 {
170 	if (!ext4_has_feature_metadata_csum(sb))
171 		return 1;
172 
173 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
174 }
175 
176 static __le32 ext4_superblock_csum(struct super_block *sb,
177 				   struct ext4_super_block *es)
178 {
179 	struct ext4_sb_info *sbi = EXT4_SB(sb);
180 	int offset = offsetof(struct ext4_super_block, s_checksum);
181 	__u32 csum;
182 
183 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
184 
185 	return cpu_to_le32(csum);
186 }
187 
188 static int ext4_superblock_csum_verify(struct super_block *sb,
189 				       struct ext4_super_block *es)
190 {
191 	if (!ext4_has_metadata_csum(sb))
192 		return 1;
193 
194 	return es->s_checksum == ext4_superblock_csum(sb, es);
195 }
196 
197 void ext4_superblock_csum_set(struct super_block *sb)
198 {
199 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
200 
201 	if (!ext4_has_metadata_csum(sb))
202 		return;
203 
204 	es->s_checksum = ext4_superblock_csum(sb, es);
205 }
206 
207 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
208 			       struct ext4_group_desc *bg)
209 {
210 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
211 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
212 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
213 }
214 
215 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
216 			       struct ext4_group_desc *bg)
217 {
218 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
219 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
220 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
221 }
222 
223 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
224 			      struct ext4_group_desc *bg)
225 {
226 	return le32_to_cpu(bg->bg_inode_table_lo) |
227 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
228 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
229 }
230 
231 __u32 ext4_free_group_clusters(struct super_block *sb,
232 			       struct ext4_group_desc *bg)
233 {
234 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
235 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
236 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
237 }
238 
239 __u32 ext4_free_inodes_count(struct super_block *sb,
240 			      struct ext4_group_desc *bg)
241 {
242 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
243 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
244 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
245 }
246 
247 __u32 ext4_used_dirs_count(struct super_block *sb,
248 			      struct ext4_group_desc *bg)
249 {
250 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
251 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
252 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
253 }
254 
255 __u32 ext4_itable_unused_count(struct super_block *sb,
256 			      struct ext4_group_desc *bg)
257 {
258 	return le16_to_cpu(bg->bg_itable_unused_lo) |
259 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
260 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
261 }
262 
263 void ext4_block_bitmap_set(struct super_block *sb,
264 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
265 {
266 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
267 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
268 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
269 }
270 
271 void ext4_inode_bitmap_set(struct super_block *sb,
272 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
273 {
274 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
275 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
276 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
277 }
278 
279 void ext4_inode_table_set(struct super_block *sb,
280 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
281 {
282 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
283 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
284 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
285 }
286 
287 void ext4_free_group_clusters_set(struct super_block *sb,
288 				  struct ext4_group_desc *bg, __u32 count)
289 {
290 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
291 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
292 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
293 }
294 
295 void ext4_free_inodes_set(struct super_block *sb,
296 			  struct ext4_group_desc *bg, __u32 count)
297 {
298 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
299 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
300 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
301 }
302 
303 void ext4_used_dirs_set(struct super_block *sb,
304 			  struct ext4_group_desc *bg, __u32 count)
305 {
306 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
307 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
308 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
309 }
310 
311 void ext4_itable_unused_set(struct super_block *sb,
312 			  struct ext4_group_desc *bg, __u32 count)
313 {
314 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
315 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
316 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
317 }
318 
319 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
320 {
321 	time64_t now = ktime_get_real_seconds();
322 
323 	now = clamp_val(now, 0, (1ull << 40) - 1);
324 
325 	*lo = cpu_to_le32(lower_32_bits(now));
326 	*hi = upper_32_bits(now);
327 }
328 
329 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
330 {
331 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
332 }
333 #define ext4_update_tstamp(es, tstamp) \
334 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
335 #define ext4_get_tstamp(es, tstamp) \
336 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
337 
338 static void __save_error_info(struct super_block *sb, int error,
339 			      __u32 ino, __u64 block,
340 			      const char *func, unsigned int line)
341 {
342 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
343 	int err;
344 
345 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
346 	if (bdev_read_only(sb->s_bdev))
347 		return;
348 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
349 	ext4_update_tstamp(es, s_last_error_time);
350 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
351 	es->s_last_error_line = cpu_to_le32(line);
352 	es->s_last_error_ino = cpu_to_le32(ino);
353 	es->s_last_error_block = cpu_to_le64(block);
354 	switch (error) {
355 	case EIO:
356 		err = EXT4_ERR_EIO;
357 		break;
358 	case ENOMEM:
359 		err = EXT4_ERR_ENOMEM;
360 		break;
361 	case EFSBADCRC:
362 		err = EXT4_ERR_EFSBADCRC;
363 		break;
364 	case 0:
365 	case EFSCORRUPTED:
366 		err = EXT4_ERR_EFSCORRUPTED;
367 		break;
368 	case ENOSPC:
369 		err = EXT4_ERR_ENOSPC;
370 		break;
371 	case ENOKEY:
372 		err = EXT4_ERR_ENOKEY;
373 		break;
374 	case EROFS:
375 		err = EXT4_ERR_EROFS;
376 		break;
377 	case EFBIG:
378 		err = EXT4_ERR_EFBIG;
379 		break;
380 	case EEXIST:
381 		err = EXT4_ERR_EEXIST;
382 		break;
383 	case ERANGE:
384 		err = EXT4_ERR_ERANGE;
385 		break;
386 	case EOVERFLOW:
387 		err = EXT4_ERR_EOVERFLOW;
388 		break;
389 	case EBUSY:
390 		err = EXT4_ERR_EBUSY;
391 		break;
392 	case ENOTDIR:
393 		err = EXT4_ERR_ENOTDIR;
394 		break;
395 	case ENOTEMPTY:
396 		err = EXT4_ERR_ENOTEMPTY;
397 		break;
398 	case ESHUTDOWN:
399 		err = EXT4_ERR_ESHUTDOWN;
400 		break;
401 	case EFAULT:
402 		err = EXT4_ERR_EFAULT;
403 		break;
404 	default:
405 		err = EXT4_ERR_UNKNOWN;
406 	}
407 	es->s_last_error_errcode = err;
408 	if (!es->s_first_error_time) {
409 		es->s_first_error_time = es->s_last_error_time;
410 		es->s_first_error_time_hi = es->s_last_error_time_hi;
411 		strncpy(es->s_first_error_func, func,
412 			sizeof(es->s_first_error_func));
413 		es->s_first_error_line = cpu_to_le32(line);
414 		es->s_first_error_ino = es->s_last_error_ino;
415 		es->s_first_error_block = es->s_last_error_block;
416 		es->s_first_error_errcode = es->s_last_error_errcode;
417 	}
418 	/*
419 	 * Start the daily error reporting function if it hasn't been
420 	 * started already
421 	 */
422 	if (!es->s_error_count)
423 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
424 	le32_add_cpu(&es->s_error_count, 1);
425 }
426 
427 static void save_error_info(struct super_block *sb, int error,
428 			    __u32 ino, __u64 block,
429 			    const char *func, unsigned int line)
430 {
431 	__save_error_info(sb, error, ino, block, func, line);
432 	if (!bdev_read_only(sb->s_bdev))
433 		ext4_commit_super(sb, 1);
434 }
435 
436 /*
437  * The del_gendisk() function uninitializes the disk-specific data
438  * structures, including the bdi structure, without telling anyone
439  * else.  Once this happens, any attempt to call mark_buffer_dirty()
440  * (for example, by ext4_commit_super), will cause a kernel OOPS.
441  * This is a kludge to prevent these oops until we can put in a proper
442  * hook in del_gendisk() to inform the VFS and file system layers.
443  */
444 static int block_device_ejected(struct super_block *sb)
445 {
446 	struct inode *bd_inode = sb->s_bdev->bd_inode;
447 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
448 
449 	return bdi->dev == NULL;
450 }
451 
452 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
453 {
454 	struct super_block		*sb = journal->j_private;
455 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
456 	int				error = is_journal_aborted(journal);
457 	struct ext4_journal_cb_entry	*jce;
458 
459 	BUG_ON(txn->t_state == T_FINISHED);
460 
461 	ext4_process_freed_data(sb, txn->t_tid);
462 
463 	spin_lock(&sbi->s_md_lock);
464 	while (!list_empty(&txn->t_private_list)) {
465 		jce = list_entry(txn->t_private_list.next,
466 				 struct ext4_journal_cb_entry, jce_list);
467 		list_del_init(&jce->jce_list);
468 		spin_unlock(&sbi->s_md_lock);
469 		jce->jce_func(sb, jce, error);
470 		spin_lock(&sbi->s_md_lock);
471 	}
472 	spin_unlock(&sbi->s_md_lock);
473 }
474 
475 static bool system_going_down(void)
476 {
477 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
478 		|| system_state == SYSTEM_RESTART;
479 }
480 
481 /* Deal with the reporting of failure conditions on a filesystem such as
482  * inconsistencies detected or read IO failures.
483  *
484  * On ext2, we can store the error state of the filesystem in the
485  * superblock.  That is not possible on ext4, because we may have other
486  * write ordering constraints on the superblock which prevent us from
487  * writing it out straight away; and given that the journal is about to
488  * be aborted, we can't rely on the current, or future, transactions to
489  * write out the superblock safely.
490  *
491  * We'll just use the jbd2_journal_abort() error code to record an error in
492  * the journal instead.  On recovery, the journal will complain about
493  * that error until we've noted it down and cleared it.
494  */
495 
496 static void ext4_handle_error(struct super_block *sb)
497 {
498 	if (test_opt(sb, WARN_ON_ERROR))
499 		WARN_ON_ONCE(1);
500 
501 	if (sb_rdonly(sb))
502 		return;
503 
504 	if (!test_opt(sb, ERRORS_CONT)) {
505 		journal_t *journal = EXT4_SB(sb)->s_journal;
506 
507 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
508 		if (journal)
509 			jbd2_journal_abort(journal, -EIO);
510 	}
511 	/*
512 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
513 	 * could panic during 'reboot -f' as the underlying device got already
514 	 * disabled.
515 	 */
516 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
517 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
518 		/*
519 		 * Make sure updated value of ->s_mount_flags will be visible
520 		 * before ->s_flags update
521 		 */
522 		smp_wmb();
523 		sb->s_flags |= SB_RDONLY;
524 	} else if (test_opt(sb, ERRORS_PANIC)) {
525 		panic("EXT4-fs (device %s): panic forced after error\n",
526 			sb->s_id);
527 	}
528 }
529 
530 #define ext4_error_ratelimit(sb)					\
531 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
532 			     "EXT4-fs error")
533 
534 void __ext4_error(struct super_block *sb, const char *function,
535 		  unsigned int line, int error, __u64 block,
536 		  const char *fmt, ...)
537 {
538 	struct va_format vaf;
539 	va_list args;
540 
541 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
542 		return;
543 
544 	trace_ext4_error(sb, function, line);
545 	if (ext4_error_ratelimit(sb)) {
546 		va_start(args, fmt);
547 		vaf.fmt = fmt;
548 		vaf.va = &args;
549 		printk(KERN_CRIT
550 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
551 		       sb->s_id, function, line, current->comm, &vaf);
552 		va_end(args);
553 	}
554 	save_error_info(sb, error, 0, block, function, line);
555 	ext4_handle_error(sb);
556 }
557 
558 void __ext4_error_inode(struct inode *inode, const char *function,
559 			unsigned int line, ext4_fsblk_t block, int error,
560 			const char *fmt, ...)
561 {
562 	va_list args;
563 	struct va_format vaf;
564 
565 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
566 		return;
567 
568 	trace_ext4_error(inode->i_sb, function, line);
569 	if (ext4_error_ratelimit(inode->i_sb)) {
570 		va_start(args, fmt);
571 		vaf.fmt = fmt;
572 		vaf.va = &args;
573 		if (block)
574 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
575 			       "inode #%lu: block %llu: comm %s: %pV\n",
576 			       inode->i_sb->s_id, function, line, inode->i_ino,
577 			       block, current->comm, &vaf);
578 		else
579 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
580 			       "inode #%lu: comm %s: %pV\n",
581 			       inode->i_sb->s_id, function, line, inode->i_ino,
582 			       current->comm, &vaf);
583 		va_end(args);
584 	}
585 	save_error_info(inode->i_sb, error, inode->i_ino, block,
586 			function, line);
587 	ext4_handle_error(inode->i_sb);
588 }
589 
590 void __ext4_error_file(struct file *file, const char *function,
591 		       unsigned int line, ext4_fsblk_t block,
592 		       const char *fmt, ...)
593 {
594 	va_list args;
595 	struct va_format vaf;
596 	struct inode *inode = file_inode(file);
597 	char pathname[80], *path;
598 
599 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
600 		return;
601 
602 	trace_ext4_error(inode->i_sb, function, line);
603 	if (ext4_error_ratelimit(inode->i_sb)) {
604 		path = file_path(file, pathname, sizeof(pathname));
605 		if (IS_ERR(path))
606 			path = "(unknown)";
607 		va_start(args, fmt);
608 		vaf.fmt = fmt;
609 		vaf.va = &args;
610 		if (block)
611 			printk(KERN_CRIT
612 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
613 			       "block %llu: comm %s: path %s: %pV\n",
614 			       inode->i_sb->s_id, function, line, inode->i_ino,
615 			       block, current->comm, path, &vaf);
616 		else
617 			printk(KERN_CRIT
618 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
619 			       "comm %s: path %s: %pV\n",
620 			       inode->i_sb->s_id, function, line, inode->i_ino,
621 			       current->comm, path, &vaf);
622 		va_end(args);
623 	}
624 	save_error_info(inode->i_sb, EFSCORRUPTED, inode->i_ino, block,
625 			function, line);
626 	ext4_handle_error(inode->i_sb);
627 }
628 
629 const char *ext4_decode_error(struct super_block *sb, int errno,
630 			      char nbuf[16])
631 {
632 	char *errstr = NULL;
633 
634 	switch (errno) {
635 	case -EFSCORRUPTED:
636 		errstr = "Corrupt filesystem";
637 		break;
638 	case -EFSBADCRC:
639 		errstr = "Filesystem failed CRC";
640 		break;
641 	case -EIO:
642 		errstr = "IO failure";
643 		break;
644 	case -ENOMEM:
645 		errstr = "Out of memory";
646 		break;
647 	case -EROFS:
648 		if (!sb || (EXT4_SB(sb)->s_journal &&
649 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
650 			errstr = "Journal has aborted";
651 		else
652 			errstr = "Readonly filesystem";
653 		break;
654 	default:
655 		/* If the caller passed in an extra buffer for unknown
656 		 * errors, textualise them now.  Else we just return
657 		 * NULL. */
658 		if (nbuf) {
659 			/* Check for truncated error codes... */
660 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
661 				errstr = nbuf;
662 		}
663 		break;
664 	}
665 
666 	return errstr;
667 }
668 
669 /* __ext4_std_error decodes expected errors from journaling functions
670  * automatically and invokes the appropriate error response.  */
671 
672 void __ext4_std_error(struct super_block *sb, const char *function,
673 		      unsigned int line, int errno)
674 {
675 	char nbuf[16];
676 	const char *errstr;
677 
678 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
679 		return;
680 
681 	/* Special case: if the error is EROFS, and we're not already
682 	 * inside a transaction, then there's really no point in logging
683 	 * an error. */
684 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
685 		return;
686 
687 	if (ext4_error_ratelimit(sb)) {
688 		errstr = ext4_decode_error(sb, errno, nbuf);
689 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
690 		       sb->s_id, function, line, errstr);
691 	}
692 
693 	save_error_info(sb, -errno, 0, 0, function, line);
694 	ext4_handle_error(sb);
695 }
696 
697 /*
698  * ext4_abort is a much stronger failure handler than ext4_error.  The
699  * abort function may be used to deal with unrecoverable failures such
700  * as journal IO errors or ENOMEM at a critical moment in log management.
701  *
702  * We unconditionally force the filesystem into an ABORT|READONLY state,
703  * unless the error response on the fs has been set to panic in which
704  * case we take the easy way out and panic immediately.
705  */
706 
707 void __ext4_abort(struct super_block *sb, const char *function,
708 		  unsigned int line, int error, const char *fmt, ...)
709 {
710 	struct va_format vaf;
711 	va_list args;
712 
713 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
714 		return;
715 
716 	save_error_info(sb, error, 0, 0, function, line);
717 	va_start(args, fmt);
718 	vaf.fmt = fmt;
719 	vaf.va = &args;
720 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
721 	       sb->s_id, function, line, &vaf);
722 	va_end(args);
723 
724 	if (sb_rdonly(sb) == 0) {
725 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
726 		if (EXT4_SB(sb)->s_journal)
727 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
728 
729 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
730 		/*
731 		 * Make sure updated value of ->s_mount_flags will be visible
732 		 * before ->s_flags update
733 		 */
734 		smp_wmb();
735 		sb->s_flags |= SB_RDONLY;
736 	}
737 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down())
738 		panic("EXT4-fs panic from previous error\n");
739 }
740 
741 void __ext4_msg(struct super_block *sb,
742 		const char *prefix, const char *fmt, ...)
743 {
744 	struct va_format vaf;
745 	va_list args;
746 
747 	atomic_inc(&EXT4_SB(sb)->s_msg_count);
748 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
749 		return;
750 
751 	va_start(args, fmt);
752 	vaf.fmt = fmt;
753 	vaf.va = &args;
754 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
755 	va_end(args);
756 }
757 
758 static int ext4_warning_ratelimit(struct super_block *sb)
759 {
760 	atomic_inc(&EXT4_SB(sb)->s_warning_count);
761 	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
762 			    "EXT4-fs warning");
763 }
764 
765 void __ext4_warning(struct super_block *sb, const char *function,
766 		    unsigned int line, const char *fmt, ...)
767 {
768 	struct va_format vaf;
769 	va_list args;
770 
771 	if (!ext4_warning_ratelimit(sb))
772 		return;
773 
774 	va_start(args, fmt);
775 	vaf.fmt = fmt;
776 	vaf.va = &args;
777 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
778 	       sb->s_id, function, line, &vaf);
779 	va_end(args);
780 }
781 
782 void __ext4_warning_inode(const struct inode *inode, const char *function,
783 			  unsigned int line, const char *fmt, ...)
784 {
785 	struct va_format vaf;
786 	va_list args;
787 
788 	if (!ext4_warning_ratelimit(inode->i_sb))
789 		return;
790 
791 	va_start(args, fmt);
792 	vaf.fmt = fmt;
793 	vaf.va = &args;
794 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
795 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
796 	       function, line, inode->i_ino, current->comm, &vaf);
797 	va_end(args);
798 }
799 
800 void __ext4_grp_locked_error(const char *function, unsigned int line,
801 			     struct super_block *sb, ext4_group_t grp,
802 			     unsigned long ino, ext4_fsblk_t block,
803 			     const char *fmt, ...)
804 __releases(bitlock)
805 __acquires(bitlock)
806 {
807 	struct va_format vaf;
808 	va_list args;
809 
810 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
811 		return;
812 
813 	trace_ext4_error(sb, function, line);
814 	__save_error_info(sb, EFSCORRUPTED, ino, block, function, line);
815 
816 	if (ext4_error_ratelimit(sb)) {
817 		va_start(args, fmt);
818 		vaf.fmt = fmt;
819 		vaf.va = &args;
820 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
821 		       sb->s_id, function, line, grp);
822 		if (ino)
823 			printk(KERN_CONT "inode %lu: ", ino);
824 		if (block)
825 			printk(KERN_CONT "block %llu:",
826 			       (unsigned long long) block);
827 		printk(KERN_CONT "%pV\n", &vaf);
828 		va_end(args);
829 	}
830 
831 	if (test_opt(sb, WARN_ON_ERROR))
832 		WARN_ON_ONCE(1);
833 
834 	if (test_opt(sb, ERRORS_CONT)) {
835 		ext4_commit_super(sb, 0);
836 		return;
837 	}
838 
839 	ext4_unlock_group(sb, grp);
840 	ext4_commit_super(sb, 1);
841 	ext4_handle_error(sb);
842 	/*
843 	 * We only get here in the ERRORS_RO case; relocking the group
844 	 * may be dangerous, but nothing bad will happen since the
845 	 * filesystem will have already been marked read/only and the
846 	 * journal has been aborted.  We return 1 as a hint to callers
847 	 * who might what to use the return value from
848 	 * ext4_grp_locked_error() to distinguish between the
849 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
850 	 * aggressively from the ext4 function in question, with a
851 	 * more appropriate error code.
852 	 */
853 	ext4_lock_group(sb, grp);
854 	return;
855 }
856 
857 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
858 				     ext4_group_t group,
859 				     unsigned int flags)
860 {
861 	struct ext4_sb_info *sbi = EXT4_SB(sb);
862 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
863 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
864 	int ret;
865 
866 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
867 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
868 					    &grp->bb_state);
869 		if (!ret)
870 			percpu_counter_sub(&sbi->s_freeclusters_counter,
871 					   grp->bb_free);
872 	}
873 
874 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
875 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
876 					    &grp->bb_state);
877 		if (!ret && gdp) {
878 			int count;
879 
880 			count = ext4_free_inodes_count(sb, gdp);
881 			percpu_counter_sub(&sbi->s_freeinodes_counter,
882 					   count);
883 		}
884 	}
885 }
886 
887 void ext4_update_dynamic_rev(struct super_block *sb)
888 {
889 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
890 
891 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
892 		return;
893 
894 	ext4_warning(sb,
895 		     "updating to rev %d because of new feature flag, "
896 		     "running e2fsck is recommended",
897 		     EXT4_DYNAMIC_REV);
898 
899 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
900 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
901 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
902 	/* leave es->s_feature_*compat flags alone */
903 	/* es->s_uuid will be set by e2fsck if empty */
904 
905 	/*
906 	 * The rest of the superblock fields should be zero, and if not it
907 	 * means they are likely already in use, so leave them alone.  We
908 	 * can leave it up to e2fsck to clean up any inconsistencies there.
909 	 */
910 }
911 
912 /*
913  * Open the external journal device
914  */
915 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
916 {
917 	struct block_device *bdev;
918 
919 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
920 	if (IS_ERR(bdev))
921 		goto fail;
922 	return bdev;
923 
924 fail:
925 	ext4_msg(sb, KERN_ERR,
926 		 "failed to open journal device unknown-block(%u,%u) %ld",
927 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
928 	return NULL;
929 }
930 
931 /*
932  * Release the journal device
933  */
934 static void ext4_blkdev_put(struct block_device *bdev)
935 {
936 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
937 }
938 
939 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
940 {
941 	struct block_device *bdev;
942 	bdev = sbi->journal_bdev;
943 	if (bdev) {
944 		ext4_blkdev_put(bdev);
945 		sbi->journal_bdev = NULL;
946 	}
947 }
948 
949 static inline struct inode *orphan_list_entry(struct list_head *l)
950 {
951 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
952 }
953 
954 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
955 {
956 	struct list_head *l;
957 
958 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
959 		 le32_to_cpu(sbi->s_es->s_last_orphan));
960 
961 	printk(KERN_ERR "sb_info orphan list:\n");
962 	list_for_each(l, &sbi->s_orphan) {
963 		struct inode *inode = orphan_list_entry(l);
964 		printk(KERN_ERR "  "
965 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
966 		       inode->i_sb->s_id, inode->i_ino, inode,
967 		       inode->i_mode, inode->i_nlink,
968 		       NEXT_ORPHAN(inode));
969 	}
970 }
971 
972 #ifdef CONFIG_QUOTA
973 static int ext4_quota_off(struct super_block *sb, int type);
974 
975 static inline void ext4_quota_off_umount(struct super_block *sb)
976 {
977 	int type;
978 
979 	/* Use our quota_off function to clear inode flags etc. */
980 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
981 		ext4_quota_off(sb, type);
982 }
983 
984 /*
985  * This is a helper function which is used in the mount/remount
986  * codepaths (which holds s_umount) to fetch the quota file name.
987  */
988 static inline char *get_qf_name(struct super_block *sb,
989 				struct ext4_sb_info *sbi,
990 				int type)
991 {
992 	return rcu_dereference_protected(sbi->s_qf_names[type],
993 					 lockdep_is_held(&sb->s_umount));
994 }
995 #else
996 static inline void ext4_quota_off_umount(struct super_block *sb)
997 {
998 }
999 #endif
1000 
1001 static void ext4_put_super(struct super_block *sb)
1002 {
1003 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1004 	struct ext4_super_block *es = sbi->s_es;
1005 	struct buffer_head **group_desc;
1006 	struct flex_groups **flex_groups;
1007 	int aborted = 0;
1008 	int i, err;
1009 
1010 	ext4_unregister_li_request(sb);
1011 	ext4_quota_off_umount(sb);
1012 
1013 	destroy_workqueue(sbi->rsv_conversion_wq);
1014 
1015 	/*
1016 	 * Unregister sysfs before destroying jbd2 journal.
1017 	 * Since we could still access attr_journal_task attribute via sysfs
1018 	 * path which could have sbi->s_journal->j_task as NULL
1019 	 */
1020 	ext4_unregister_sysfs(sb);
1021 
1022 	if (sbi->s_journal) {
1023 		aborted = is_journal_aborted(sbi->s_journal);
1024 		err = jbd2_journal_destroy(sbi->s_journal);
1025 		sbi->s_journal = NULL;
1026 		if ((err < 0) && !aborted) {
1027 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1028 		}
1029 	}
1030 
1031 	ext4_es_unregister_shrinker(sbi);
1032 	del_timer_sync(&sbi->s_err_report);
1033 	ext4_release_system_zone(sb);
1034 	ext4_mb_release(sb);
1035 	ext4_ext_release(sb);
1036 
1037 	if (!sb_rdonly(sb) && !aborted) {
1038 		ext4_clear_feature_journal_needs_recovery(sb);
1039 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1040 	}
1041 	if (!sb_rdonly(sb))
1042 		ext4_commit_super(sb, 1);
1043 
1044 	rcu_read_lock();
1045 	group_desc = rcu_dereference(sbi->s_group_desc);
1046 	for (i = 0; i < sbi->s_gdb_count; i++)
1047 		brelse(group_desc[i]);
1048 	kvfree(group_desc);
1049 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1050 	if (flex_groups) {
1051 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1052 			kvfree(flex_groups[i]);
1053 		kvfree(flex_groups);
1054 	}
1055 	rcu_read_unlock();
1056 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1057 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1058 	percpu_counter_destroy(&sbi->s_dirs_counter);
1059 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1060 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1061 #ifdef CONFIG_QUOTA
1062 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1063 		kfree(get_qf_name(sb, sbi, i));
1064 #endif
1065 
1066 	/* Debugging code just in case the in-memory inode orphan list
1067 	 * isn't empty.  The on-disk one can be non-empty if we've
1068 	 * detected an error and taken the fs readonly, but the
1069 	 * in-memory list had better be clean by this point. */
1070 	if (!list_empty(&sbi->s_orphan))
1071 		dump_orphan_list(sb, sbi);
1072 	J_ASSERT(list_empty(&sbi->s_orphan));
1073 
1074 	sync_blockdev(sb->s_bdev);
1075 	invalidate_bdev(sb->s_bdev);
1076 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1077 		/*
1078 		 * Invalidate the journal device's buffers.  We don't want them
1079 		 * floating about in memory - the physical journal device may
1080 		 * hotswapped, and it breaks the `ro-after' testing code.
1081 		 */
1082 		sync_blockdev(sbi->journal_bdev);
1083 		invalidate_bdev(sbi->journal_bdev);
1084 		ext4_blkdev_remove(sbi);
1085 	}
1086 
1087 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1088 	sbi->s_ea_inode_cache = NULL;
1089 
1090 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1091 	sbi->s_ea_block_cache = NULL;
1092 
1093 	if (sbi->s_mmp_tsk)
1094 		kthread_stop(sbi->s_mmp_tsk);
1095 	brelse(sbi->s_sbh);
1096 	sb->s_fs_info = NULL;
1097 	/*
1098 	 * Now that we are completely done shutting down the
1099 	 * superblock, we need to actually destroy the kobject.
1100 	 */
1101 	kobject_put(&sbi->s_kobj);
1102 	wait_for_completion(&sbi->s_kobj_unregister);
1103 	if (sbi->s_chksum_driver)
1104 		crypto_free_shash(sbi->s_chksum_driver);
1105 	kfree(sbi->s_blockgroup_lock);
1106 	fs_put_dax(sbi->s_daxdev);
1107 	fscrypt_free_dummy_context(&sbi->s_dummy_enc_ctx);
1108 #ifdef CONFIG_UNICODE
1109 	utf8_unload(sbi->s_encoding);
1110 #endif
1111 	kfree(sbi);
1112 }
1113 
1114 static struct kmem_cache *ext4_inode_cachep;
1115 
1116 /*
1117  * Called inside transaction, so use GFP_NOFS
1118  */
1119 static struct inode *ext4_alloc_inode(struct super_block *sb)
1120 {
1121 	struct ext4_inode_info *ei;
1122 
1123 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1124 	if (!ei)
1125 		return NULL;
1126 
1127 	inode_set_iversion(&ei->vfs_inode, 1);
1128 	spin_lock_init(&ei->i_raw_lock);
1129 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1130 	atomic_set(&ei->i_prealloc_active, 0);
1131 	spin_lock_init(&ei->i_prealloc_lock);
1132 	ext4_es_init_tree(&ei->i_es_tree);
1133 	rwlock_init(&ei->i_es_lock);
1134 	INIT_LIST_HEAD(&ei->i_es_list);
1135 	ei->i_es_all_nr = 0;
1136 	ei->i_es_shk_nr = 0;
1137 	ei->i_es_shrink_lblk = 0;
1138 	ei->i_reserved_data_blocks = 0;
1139 	spin_lock_init(&(ei->i_block_reservation_lock));
1140 	ext4_init_pending_tree(&ei->i_pending_tree);
1141 #ifdef CONFIG_QUOTA
1142 	ei->i_reserved_quota = 0;
1143 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1144 #endif
1145 	ei->jinode = NULL;
1146 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1147 	spin_lock_init(&ei->i_completed_io_lock);
1148 	ei->i_sync_tid = 0;
1149 	ei->i_datasync_tid = 0;
1150 	atomic_set(&ei->i_unwritten, 0);
1151 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1152 	return &ei->vfs_inode;
1153 }
1154 
1155 static int ext4_drop_inode(struct inode *inode)
1156 {
1157 	int drop = generic_drop_inode(inode);
1158 
1159 	if (!drop)
1160 		drop = fscrypt_drop_inode(inode);
1161 
1162 	trace_ext4_drop_inode(inode, drop);
1163 	return drop;
1164 }
1165 
1166 static void ext4_free_in_core_inode(struct inode *inode)
1167 {
1168 	fscrypt_free_inode(inode);
1169 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1170 }
1171 
1172 static void ext4_destroy_inode(struct inode *inode)
1173 {
1174 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1175 		ext4_msg(inode->i_sb, KERN_ERR,
1176 			 "Inode %lu (%p): orphan list check failed!",
1177 			 inode->i_ino, EXT4_I(inode));
1178 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1179 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1180 				true);
1181 		dump_stack();
1182 	}
1183 }
1184 
1185 static void init_once(void *foo)
1186 {
1187 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1188 
1189 	INIT_LIST_HEAD(&ei->i_orphan);
1190 	init_rwsem(&ei->xattr_sem);
1191 	init_rwsem(&ei->i_data_sem);
1192 	init_rwsem(&ei->i_mmap_sem);
1193 	inode_init_once(&ei->vfs_inode);
1194 }
1195 
1196 static int __init init_inodecache(void)
1197 {
1198 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1199 				sizeof(struct ext4_inode_info), 0,
1200 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1201 					SLAB_ACCOUNT),
1202 				offsetof(struct ext4_inode_info, i_data),
1203 				sizeof_field(struct ext4_inode_info, i_data),
1204 				init_once);
1205 	if (ext4_inode_cachep == NULL)
1206 		return -ENOMEM;
1207 	return 0;
1208 }
1209 
1210 static void destroy_inodecache(void)
1211 {
1212 	/*
1213 	 * Make sure all delayed rcu free inodes are flushed before we
1214 	 * destroy cache.
1215 	 */
1216 	rcu_barrier();
1217 	kmem_cache_destroy(ext4_inode_cachep);
1218 }
1219 
1220 void ext4_clear_inode(struct inode *inode)
1221 {
1222 	invalidate_inode_buffers(inode);
1223 	clear_inode(inode);
1224 	ext4_discard_preallocations(inode, 0);
1225 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1226 	dquot_drop(inode);
1227 	if (EXT4_I(inode)->jinode) {
1228 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1229 					       EXT4_I(inode)->jinode);
1230 		jbd2_free_inode(EXT4_I(inode)->jinode);
1231 		EXT4_I(inode)->jinode = NULL;
1232 	}
1233 	fscrypt_put_encryption_info(inode);
1234 	fsverity_cleanup_inode(inode);
1235 }
1236 
1237 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1238 					u64 ino, u32 generation)
1239 {
1240 	struct inode *inode;
1241 
1242 	/*
1243 	 * Currently we don't know the generation for parent directory, so
1244 	 * a generation of 0 means "accept any"
1245 	 */
1246 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1247 	if (IS_ERR(inode))
1248 		return ERR_CAST(inode);
1249 	if (generation && inode->i_generation != generation) {
1250 		iput(inode);
1251 		return ERR_PTR(-ESTALE);
1252 	}
1253 
1254 	return inode;
1255 }
1256 
1257 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1258 					int fh_len, int fh_type)
1259 {
1260 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1261 				    ext4_nfs_get_inode);
1262 }
1263 
1264 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1265 					int fh_len, int fh_type)
1266 {
1267 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1268 				    ext4_nfs_get_inode);
1269 }
1270 
1271 static int ext4_nfs_commit_metadata(struct inode *inode)
1272 {
1273 	struct writeback_control wbc = {
1274 		.sync_mode = WB_SYNC_ALL
1275 	};
1276 
1277 	trace_ext4_nfs_commit_metadata(inode);
1278 	return ext4_write_inode(inode, &wbc);
1279 }
1280 
1281 /*
1282  * Try to release metadata pages (indirect blocks, directories) which are
1283  * mapped via the block device.  Since these pages could have journal heads
1284  * which would prevent try_to_free_buffers() from freeing them, we must use
1285  * jbd2 layer's try_to_free_buffers() function to release them.
1286  */
1287 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1288 				 gfp_t wait)
1289 {
1290 	journal_t *journal = EXT4_SB(sb)->s_journal;
1291 
1292 	WARN_ON(PageChecked(page));
1293 	if (!page_has_buffers(page))
1294 		return 0;
1295 	if (journal)
1296 		return jbd2_journal_try_to_free_buffers(journal, page);
1297 
1298 	return try_to_free_buffers(page);
1299 }
1300 
1301 #ifdef CONFIG_FS_ENCRYPTION
1302 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1303 {
1304 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1305 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1306 }
1307 
1308 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1309 							void *fs_data)
1310 {
1311 	handle_t *handle = fs_data;
1312 	int res, res2, credits, retries = 0;
1313 
1314 	/*
1315 	 * Encrypting the root directory is not allowed because e2fsck expects
1316 	 * lost+found to exist and be unencrypted, and encrypting the root
1317 	 * directory would imply encrypting the lost+found directory as well as
1318 	 * the filename "lost+found" itself.
1319 	 */
1320 	if (inode->i_ino == EXT4_ROOT_INO)
1321 		return -EPERM;
1322 
1323 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1324 		return -EINVAL;
1325 
1326 	if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1327 		return -EOPNOTSUPP;
1328 
1329 	res = ext4_convert_inline_data(inode);
1330 	if (res)
1331 		return res;
1332 
1333 	/*
1334 	 * If a journal handle was specified, then the encryption context is
1335 	 * being set on a new inode via inheritance and is part of a larger
1336 	 * transaction to create the inode.  Otherwise the encryption context is
1337 	 * being set on an existing inode in its own transaction.  Only in the
1338 	 * latter case should the "retry on ENOSPC" logic be used.
1339 	 */
1340 
1341 	if (handle) {
1342 		res = ext4_xattr_set_handle(handle, inode,
1343 					    EXT4_XATTR_INDEX_ENCRYPTION,
1344 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1345 					    ctx, len, 0);
1346 		if (!res) {
1347 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1348 			ext4_clear_inode_state(inode,
1349 					EXT4_STATE_MAY_INLINE_DATA);
1350 			/*
1351 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1352 			 * S_DAX may be disabled
1353 			 */
1354 			ext4_set_inode_flags(inode, false);
1355 		}
1356 		return res;
1357 	}
1358 
1359 	res = dquot_initialize(inode);
1360 	if (res)
1361 		return res;
1362 retry:
1363 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1364 				     &credits);
1365 	if (res)
1366 		return res;
1367 
1368 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1369 	if (IS_ERR(handle))
1370 		return PTR_ERR(handle);
1371 
1372 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1373 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1374 				    ctx, len, 0);
1375 	if (!res) {
1376 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1377 		/*
1378 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1379 		 * S_DAX may be disabled
1380 		 */
1381 		ext4_set_inode_flags(inode, false);
1382 		res = ext4_mark_inode_dirty(handle, inode);
1383 		if (res)
1384 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1385 	}
1386 	res2 = ext4_journal_stop(handle);
1387 
1388 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1389 		goto retry;
1390 	if (!res)
1391 		res = res2;
1392 	return res;
1393 }
1394 
1395 static const union fscrypt_context *
1396 ext4_get_dummy_context(struct super_block *sb)
1397 {
1398 	return EXT4_SB(sb)->s_dummy_enc_ctx.ctx;
1399 }
1400 
1401 static bool ext4_has_stable_inodes(struct super_block *sb)
1402 {
1403 	return ext4_has_feature_stable_inodes(sb);
1404 }
1405 
1406 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1407 				       int *ino_bits_ret, int *lblk_bits_ret)
1408 {
1409 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1410 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1411 }
1412 
1413 static const struct fscrypt_operations ext4_cryptops = {
1414 	.key_prefix		= "ext4:",
1415 	.get_context		= ext4_get_context,
1416 	.set_context		= ext4_set_context,
1417 	.get_dummy_context	= ext4_get_dummy_context,
1418 	.empty_dir		= ext4_empty_dir,
1419 	.max_namelen		= EXT4_NAME_LEN,
1420 	.has_stable_inodes	= ext4_has_stable_inodes,
1421 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1422 };
1423 #endif
1424 
1425 #ifdef CONFIG_QUOTA
1426 static const char * const quotatypes[] = INITQFNAMES;
1427 #define QTYPE2NAME(t) (quotatypes[t])
1428 
1429 static int ext4_write_dquot(struct dquot *dquot);
1430 static int ext4_acquire_dquot(struct dquot *dquot);
1431 static int ext4_release_dquot(struct dquot *dquot);
1432 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1433 static int ext4_write_info(struct super_block *sb, int type);
1434 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1435 			 const struct path *path);
1436 static int ext4_quota_on_mount(struct super_block *sb, int type);
1437 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1438 			       size_t len, loff_t off);
1439 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1440 				const char *data, size_t len, loff_t off);
1441 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1442 			     unsigned int flags);
1443 static int ext4_enable_quotas(struct super_block *sb);
1444 
1445 static struct dquot **ext4_get_dquots(struct inode *inode)
1446 {
1447 	return EXT4_I(inode)->i_dquot;
1448 }
1449 
1450 static const struct dquot_operations ext4_quota_operations = {
1451 	.get_reserved_space	= ext4_get_reserved_space,
1452 	.write_dquot		= ext4_write_dquot,
1453 	.acquire_dquot		= ext4_acquire_dquot,
1454 	.release_dquot		= ext4_release_dquot,
1455 	.mark_dirty		= ext4_mark_dquot_dirty,
1456 	.write_info		= ext4_write_info,
1457 	.alloc_dquot		= dquot_alloc,
1458 	.destroy_dquot		= dquot_destroy,
1459 	.get_projid		= ext4_get_projid,
1460 	.get_inode_usage	= ext4_get_inode_usage,
1461 	.get_next_id		= dquot_get_next_id,
1462 };
1463 
1464 static const struct quotactl_ops ext4_qctl_operations = {
1465 	.quota_on	= ext4_quota_on,
1466 	.quota_off	= ext4_quota_off,
1467 	.quota_sync	= dquot_quota_sync,
1468 	.get_state	= dquot_get_state,
1469 	.set_info	= dquot_set_dqinfo,
1470 	.get_dqblk	= dquot_get_dqblk,
1471 	.set_dqblk	= dquot_set_dqblk,
1472 	.get_nextdqblk	= dquot_get_next_dqblk,
1473 };
1474 #endif
1475 
1476 static const struct super_operations ext4_sops = {
1477 	.alloc_inode	= ext4_alloc_inode,
1478 	.free_inode	= ext4_free_in_core_inode,
1479 	.destroy_inode	= ext4_destroy_inode,
1480 	.write_inode	= ext4_write_inode,
1481 	.dirty_inode	= ext4_dirty_inode,
1482 	.drop_inode	= ext4_drop_inode,
1483 	.evict_inode	= ext4_evict_inode,
1484 	.put_super	= ext4_put_super,
1485 	.sync_fs	= ext4_sync_fs,
1486 	.freeze_fs	= ext4_freeze,
1487 	.unfreeze_fs	= ext4_unfreeze,
1488 	.statfs		= ext4_statfs,
1489 	.remount_fs	= ext4_remount,
1490 	.show_options	= ext4_show_options,
1491 #ifdef CONFIG_QUOTA
1492 	.quota_read	= ext4_quota_read,
1493 	.quota_write	= ext4_quota_write,
1494 	.get_dquots	= ext4_get_dquots,
1495 #endif
1496 	.bdev_try_to_free_page = bdev_try_to_free_page,
1497 };
1498 
1499 static const struct export_operations ext4_export_ops = {
1500 	.fh_to_dentry = ext4_fh_to_dentry,
1501 	.fh_to_parent = ext4_fh_to_parent,
1502 	.get_parent = ext4_get_parent,
1503 	.commit_metadata = ext4_nfs_commit_metadata,
1504 };
1505 
1506 enum {
1507 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1508 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1509 	Opt_nouid32, Opt_debug, Opt_removed,
1510 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1511 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1512 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1513 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1514 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1515 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1516 	Opt_inlinecrypt,
1517 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1518 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1519 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1520 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1521 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1522 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1523 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1524 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1525 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1526 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1527 	Opt_dioread_nolock, Opt_dioread_lock,
1528 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1529 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1530 	Opt_prefetch_block_bitmaps,
1531 };
1532 
1533 static const match_table_t tokens = {
1534 	{Opt_bsd_df, "bsddf"},
1535 	{Opt_minix_df, "minixdf"},
1536 	{Opt_grpid, "grpid"},
1537 	{Opt_grpid, "bsdgroups"},
1538 	{Opt_nogrpid, "nogrpid"},
1539 	{Opt_nogrpid, "sysvgroups"},
1540 	{Opt_resgid, "resgid=%u"},
1541 	{Opt_resuid, "resuid=%u"},
1542 	{Opt_sb, "sb=%u"},
1543 	{Opt_err_cont, "errors=continue"},
1544 	{Opt_err_panic, "errors=panic"},
1545 	{Opt_err_ro, "errors=remount-ro"},
1546 	{Opt_nouid32, "nouid32"},
1547 	{Opt_debug, "debug"},
1548 	{Opt_removed, "oldalloc"},
1549 	{Opt_removed, "orlov"},
1550 	{Opt_user_xattr, "user_xattr"},
1551 	{Opt_nouser_xattr, "nouser_xattr"},
1552 	{Opt_acl, "acl"},
1553 	{Opt_noacl, "noacl"},
1554 	{Opt_noload, "norecovery"},
1555 	{Opt_noload, "noload"},
1556 	{Opt_removed, "nobh"},
1557 	{Opt_removed, "bh"},
1558 	{Opt_commit, "commit=%u"},
1559 	{Opt_min_batch_time, "min_batch_time=%u"},
1560 	{Opt_max_batch_time, "max_batch_time=%u"},
1561 	{Opt_journal_dev, "journal_dev=%u"},
1562 	{Opt_journal_path, "journal_path=%s"},
1563 	{Opt_journal_checksum, "journal_checksum"},
1564 	{Opt_nojournal_checksum, "nojournal_checksum"},
1565 	{Opt_journal_async_commit, "journal_async_commit"},
1566 	{Opt_abort, "abort"},
1567 	{Opt_data_journal, "data=journal"},
1568 	{Opt_data_ordered, "data=ordered"},
1569 	{Opt_data_writeback, "data=writeback"},
1570 	{Opt_data_err_abort, "data_err=abort"},
1571 	{Opt_data_err_ignore, "data_err=ignore"},
1572 	{Opt_offusrjquota, "usrjquota="},
1573 	{Opt_usrjquota, "usrjquota=%s"},
1574 	{Opt_offgrpjquota, "grpjquota="},
1575 	{Opt_grpjquota, "grpjquota=%s"},
1576 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1577 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1578 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1579 	{Opt_grpquota, "grpquota"},
1580 	{Opt_noquota, "noquota"},
1581 	{Opt_quota, "quota"},
1582 	{Opt_usrquota, "usrquota"},
1583 	{Opt_prjquota, "prjquota"},
1584 	{Opt_barrier, "barrier=%u"},
1585 	{Opt_barrier, "barrier"},
1586 	{Opt_nobarrier, "nobarrier"},
1587 	{Opt_i_version, "i_version"},
1588 	{Opt_dax, "dax"},
1589 	{Opt_dax_always, "dax=always"},
1590 	{Opt_dax_inode, "dax=inode"},
1591 	{Opt_dax_never, "dax=never"},
1592 	{Opt_stripe, "stripe=%u"},
1593 	{Opt_delalloc, "delalloc"},
1594 	{Opt_warn_on_error, "warn_on_error"},
1595 	{Opt_nowarn_on_error, "nowarn_on_error"},
1596 	{Opt_lazytime, "lazytime"},
1597 	{Opt_nolazytime, "nolazytime"},
1598 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1599 	{Opt_nodelalloc, "nodelalloc"},
1600 	{Opt_removed, "mblk_io_submit"},
1601 	{Opt_removed, "nomblk_io_submit"},
1602 	{Opt_block_validity, "block_validity"},
1603 	{Opt_noblock_validity, "noblock_validity"},
1604 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1605 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1606 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1607 	{Opt_auto_da_alloc, "auto_da_alloc"},
1608 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1609 	{Opt_dioread_nolock, "dioread_nolock"},
1610 	{Opt_dioread_lock, "nodioread_nolock"},
1611 	{Opt_dioread_lock, "dioread_lock"},
1612 	{Opt_discard, "discard"},
1613 	{Opt_nodiscard, "nodiscard"},
1614 	{Opt_init_itable, "init_itable=%u"},
1615 	{Opt_init_itable, "init_itable"},
1616 	{Opt_noinit_itable, "noinit_itable"},
1617 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1618 	{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1619 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1620 	{Opt_inlinecrypt, "inlinecrypt"},
1621 	{Opt_nombcache, "nombcache"},
1622 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1623 	{Opt_prefetch_block_bitmaps, "prefetch_block_bitmaps"},
1624 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1625 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1626 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1627 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1628 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1629 	{Opt_err, NULL},
1630 };
1631 
1632 static ext4_fsblk_t get_sb_block(void **data)
1633 {
1634 	ext4_fsblk_t	sb_block;
1635 	char		*options = (char *) *data;
1636 
1637 	if (!options || strncmp(options, "sb=", 3) != 0)
1638 		return 1;	/* Default location */
1639 
1640 	options += 3;
1641 	/* TODO: use simple_strtoll with >32bit ext4 */
1642 	sb_block = simple_strtoul(options, &options, 0);
1643 	if (*options && *options != ',') {
1644 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1645 		       (char *) *data);
1646 		return 1;
1647 	}
1648 	if (*options == ',')
1649 		options++;
1650 	*data = (void *) options;
1651 
1652 	return sb_block;
1653 }
1654 
1655 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1656 static const char deprecated_msg[] =
1657 	"Mount option \"%s\" will be removed by %s\n"
1658 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1659 
1660 #ifdef CONFIG_QUOTA
1661 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1662 {
1663 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1664 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1665 	int ret = -1;
1666 
1667 	if (sb_any_quota_loaded(sb) && !old_qname) {
1668 		ext4_msg(sb, KERN_ERR,
1669 			"Cannot change journaled "
1670 			"quota options when quota turned on");
1671 		return -1;
1672 	}
1673 	if (ext4_has_feature_quota(sb)) {
1674 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1675 			 "ignored when QUOTA feature is enabled");
1676 		return 1;
1677 	}
1678 	qname = match_strdup(args);
1679 	if (!qname) {
1680 		ext4_msg(sb, KERN_ERR,
1681 			"Not enough memory for storing quotafile name");
1682 		return -1;
1683 	}
1684 	if (old_qname) {
1685 		if (strcmp(old_qname, qname) == 0)
1686 			ret = 1;
1687 		else
1688 			ext4_msg(sb, KERN_ERR,
1689 				 "%s quota file already specified",
1690 				 QTYPE2NAME(qtype));
1691 		goto errout;
1692 	}
1693 	if (strchr(qname, '/')) {
1694 		ext4_msg(sb, KERN_ERR,
1695 			"quotafile must be on filesystem root");
1696 		goto errout;
1697 	}
1698 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1699 	set_opt(sb, QUOTA);
1700 	return 1;
1701 errout:
1702 	kfree(qname);
1703 	return ret;
1704 }
1705 
1706 static int clear_qf_name(struct super_block *sb, int qtype)
1707 {
1708 
1709 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1710 	char *old_qname = get_qf_name(sb, sbi, qtype);
1711 
1712 	if (sb_any_quota_loaded(sb) && old_qname) {
1713 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1714 			" when quota turned on");
1715 		return -1;
1716 	}
1717 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1718 	synchronize_rcu();
1719 	kfree(old_qname);
1720 	return 1;
1721 }
1722 #endif
1723 
1724 #define MOPT_SET	0x0001
1725 #define MOPT_CLEAR	0x0002
1726 #define MOPT_NOSUPPORT	0x0004
1727 #define MOPT_EXPLICIT	0x0008
1728 #define MOPT_CLEAR_ERR	0x0010
1729 #define MOPT_GTE0	0x0020
1730 #ifdef CONFIG_QUOTA
1731 #define MOPT_Q		0
1732 #define MOPT_QFMT	0x0040
1733 #else
1734 #define MOPT_Q		MOPT_NOSUPPORT
1735 #define MOPT_QFMT	MOPT_NOSUPPORT
1736 #endif
1737 #define MOPT_DATAJ	0x0080
1738 #define MOPT_NO_EXT2	0x0100
1739 #define MOPT_NO_EXT3	0x0200
1740 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1741 #define MOPT_STRING	0x0400
1742 #define MOPT_SKIP	0x0800
1743 
1744 static const struct mount_opts {
1745 	int	token;
1746 	int	mount_opt;
1747 	int	flags;
1748 } ext4_mount_opts[] = {
1749 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1750 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1751 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1752 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1753 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1754 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1755 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1756 	 MOPT_EXT4_ONLY | MOPT_SET},
1757 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1758 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1759 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1760 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1761 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1762 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1763 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1764 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1765 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1766 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1767 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1768 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1769 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1770 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1771 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1772 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1773 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1774 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1775 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1776 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1777 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1778 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1779 	 MOPT_NO_EXT2},
1780 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1781 	 MOPT_NO_EXT2},
1782 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1783 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1784 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1785 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1786 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1787 	{Opt_commit, 0, MOPT_GTE0},
1788 	{Opt_max_batch_time, 0, MOPT_GTE0},
1789 	{Opt_min_batch_time, 0, MOPT_GTE0},
1790 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1791 	{Opt_init_itable, 0, MOPT_GTE0},
1792 	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
1793 	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
1794 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1795 	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
1796 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1797 	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
1798 		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
1799 	{Opt_stripe, 0, MOPT_GTE0},
1800 	{Opt_resuid, 0, MOPT_GTE0},
1801 	{Opt_resgid, 0, MOPT_GTE0},
1802 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1803 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1804 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1805 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1806 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1807 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1808 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1809 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1810 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1811 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1812 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1813 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1814 #else
1815 	{Opt_acl, 0, MOPT_NOSUPPORT},
1816 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1817 #endif
1818 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1819 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1820 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1821 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1822 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1823 							MOPT_SET | MOPT_Q},
1824 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1825 							MOPT_SET | MOPT_Q},
1826 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1827 							MOPT_SET | MOPT_Q},
1828 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1829 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1830 							MOPT_CLEAR | MOPT_Q},
1831 	{Opt_usrjquota, 0, MOPT_Q},
1832 	{Opt_grpjquota, 0, MOPT_Q},
1833 	{Opt_offusrjquota, 0, MOPT_Q},
1834 	{Opt_offgrpjquota, 0, MOPT_Q},
1835 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1836 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1837 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1838 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1839 	{Opt_test_dummy_encryption, 0, MOPT_STRING},
1840 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1841 	{Opt_prefetch_block_bitmaps, EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS,
1842 	 MOPT_SET},
1843 	{Opt_err, 0, 0}
1844 };
1845 
1846 #ifdef CONFIG_UNICODE
1847 static const struct ext4_sb_encodings {
1848 	__u16 magic;
1849 	char *name;
1850 	char *version;
1851 } ext4_sb_encoding_map[] = {
1852 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1853 };
1854 
1855 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1856 				 const struct ext4_sb_encodings **encoding,
1857 				 __u16 *flags)
1858 {
1859 	__u16 magic = le16_to_cpu(es->s_encoding);
1860 	int i;
1861 
1862 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1863 		if (magic == ext4_sb_encoding_map[i].magic)
1864 			break;
1865 
1866 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1867 		return -EINVAL;
1868 
1869 	*encoding = &ext4_sb_encoding_map[i];
1870 	*flags = le16_to_cpu(es->s_encoding_flags);
1871 
1872 	return 0;
1873 }
1874 #endif
1875 
1876 static int ext4_set_test_dummy_encryption(struct super_block *sb,
1877 					  const char *opt,
1878 					  const substring_t *arg,
1879 					  bool is_remount)
1880 {
1881 #ifdef CONFIG_FS_ENCRYPTION
1882 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1883 	int err;
1884 
1885 	/*
1886 	 * This mount option is just for testing, and it's not worthwhile to
1887 	 * implement the extra complexity (e.g. RCU protection) that would be
1888 	 * needed to allow it to be set or changed during remount.  We do allow
1889 	 * it to be specified during remount, but only if there is no change.
1890 	 */
1891 	if (is_remount && !sbi->s_dummy_enc_ctx.ctx) {
1892 		ext4_msg(sb, KERN_WARNING,
1893 			 "Can't set test_dummy_encryption on remount");
1894 		return -1;
1895 	}
1896 	err = fscrypt_set_test_dummy_encryption(sb, arg, &sbi->s_dummy_enc_ctx);
1897 	if (err) {
1898 		if (err == -EEXIST)
1899 			ext4_msg(sb, KERN_WARNING,
1900 				 "Can't change test_dummy_encryption on remount");
1901 		else if (err == -EINVAL)
1902 			ext4_msg(sb, KERN_WARNING,
1903 				 "Value of option \"%s\" is unrecognized", opt);
1904 		else
1905 			ext4_msg(sb, KERN_WARNING,
1906 				 "Error processing option \"%s\" [%d]",
1907 				 opt, err);
1908 		return -1;
1909 	}
1910 	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
1911 #else
1912 	ext4_msg(sb, KERN_WARNING,
1913 		 "Test dummy encryption mount option ignored");
1914 #endif
1915 	return 1;
1916 }
1917 
1918 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1919 			    substring_t *args, unsigned long *journal_devnum,
1920 			    unsigned int *journal_ioprio, int is_remount)
1921 {
1922 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1923 	const struct mount_opts *m;
1924 	kuid_t uid;
1925 	kgid_t gid;
1926 	int arg = 0;
1927 
1928 #ifdef CONFIG_QUOTA
1929 	if (token == Opt_usrjquota)
1930 		return set_qf_name(sb, USRQUOTA, &args[0]);
1931 	else if (token == Opt_grpjquota)
1932 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1933 	else if (token == Opt_offusrjquota)
1934 		return clear_qf_name(sb, USRQUOTA);
1935 	else if (token == Opt_offgrpjquota)
1936 		return clear_qf_name(sb, GRPQUOTA);
1937 #endif
1938 	switch (token) {
1939 	case Opt_noacl:
1940 	case Opt_nouser_xattr:
1941 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1942 		break;
1943 	case Opt_sb:
1944 		return 1;	/* handled by get_sb_block() */
1945 	case Opt_removed:
1946 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1947 		return 1;
1948 	case Opt_abort:
1949 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1950 		return 1;
1951 	case Opt_i_version:
1952 		sb->s_flags |= SB_I_VERSION;
1953 		return 1;
1954 	case Opt_lazytime:
1955 		sb->s_flags |= SB_LAZYTIME;
1956 		return 1;
1957 	case Opt_nolazytime:
1958 		sb->s_flags &= ~SB_LAZYTIME;
1959 		return 1;
1960 	case Opt_inlinecrypt:
1961 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
1962 		sb->s_flags |= SB_INLINECRYPT;
1963 #else
1964 		ext4_msg(sb, KERN_ERR, "inline encryption not supported");
1965 #endif
1966 		return 1;
1967 	}
1968 
1969 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1970 		if (token == m->token)
1971 			break;
1972 
1973 	if (m->token == Opt_err) {
1974 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1975 			 "or missing value", opt);
1976 		return -1;
1977 	}
1978 
1979 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1980 		ext4_msg(sb, KERN_ERR,
1981 			 "Mount option \"%s\" incompatible with ext2", opt);
1982 		return -1;
1983 	}
1984 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1985 		ext4_msg(sb, KERN_ERR,
1986 			 "Mount option \"%s\" incompatible with ext3", opt);
1987 		return -1;
1988 	}
1989 
1990 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1991 		return -1;
1992 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1993 		return -1;
1994 	if (m->flags & MOPT_EXPLICIT) {
1995 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1996 			set_opt2(sb, EXPLICIT_DELALLOC);
1997 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1998 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1999 		} else
2000 			return -1;
2001 	}
2002 	if (m->flags & MOPT_CLEAR_ERR)
2003 		clear_opt(sb, ERRORS_MASK);
2004 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
2005 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
2006 			 "options when quota turned on");
2007 		return -1;
2008 	}
2009 
2010 	if (m->flags & MOPT_NOSUPPORT) {
2011 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
2012 	} else if (token == Opt_commit) {
2013 		if (arg == 0)
2014 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
2015 		else if (arg > INT_MAX / HZ) {
2016 			ext4_msg(sb, KERN_ERR,
2017 				 "Invalid commit interval %d, "
2018 				 "must be smaller than %d",
2019 				 arg, INT_MAX / HZ);
2020 			return -1;
2021 		}
2022 		sbi->s_commit_interval = HZ * arg;
2023 	} else if (token == Opt_debug_want_extra_isize) {
2024 		if ((arg & 1) ||
2025 		    (arg < 4) ||
2026 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
2027 			ext4_msg(sb, KERN_ERR,
2028 				 "Invalid want_extra_isize %d", arg);
2029 			return -1;
2030 		}
2031 		sbi->s_want_extra_isize = arg;
2032 	} else if (token == Opt_max_batch_time) {
2033 		sbi->s_max_batch_time = arg;
2034 	} else if (token == Opt_min_batch_time) {
2035 		sbi->s_min_batch_time = arg;
2036 	} else if (token == Opt_inode_readahead_blks) {
2037 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
2038 			ext4_msg(sb, KERN_ERR,
2039 				 "EXT4-fs: inode_readahead_blks must be "
2040 				 "0 or a power of 2 smaller than 2^31");
2041 			return -1;
2042 		}
2043 		sbi->s_inode_readahead_blks = arg;
2044 	} else if (token == Opt_init_itable) {
2045 		set_opt(sb, INIT_INODE_TABLE);
2046 		if (!args->from)
2047 			arg = EXT4_DEF_LI_WAIT_MULT;
2048 		sbi->s_li_wait_mult = arg;
2049 	} else if (token == Opt_max_dir_size_kb) {
2050 		sbi->s_max_dir_size_kb = arg;
2051 	} else if (token == Opt_stripe) {
2052 		sbi->s_stripe = arg;
2053 	} else if (token == Opt_resuid) {
2054 		uid = make_kuid(current_user_ns(), arg);
2055 		if (!uid_valid(uid)) {
2056 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
2057 			return -1;
2058 		}
2059 		sbi->s_resuid = uid;
2060 	} else if (token == Opt_resgid) {
2061 		gid = make_kgid(current_user_ns(), arg);
2062 		if (!gid_valid(gid)) {
2063 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
2064 			return -1;
2065 		}
2066 		sbi->s_resgid = gid;
2067 	} else if (token == Opt_journal_dev) {
2068 		if (is_remount) {
2069 			ext4_msg(sb, KERN_ERR,
2070 				 "Cannot specify journal on remount");
2071 			return -1;
2072 		}
2073 		*journal_devnum = arg;
2074 	} else if (token == Opt_journal_path) {
2075 		char *journal_path;
2076 		struct inode *journal_inode;
2077 		struct path path;
2078 		int error;
2079 
2080 		if (is_remount) {
2081 			ext4_msg(sb, KERN_ERR,
2082 				 "Cannot specify journal on remount");
2083 			return -1;
2084 		}
2085 		journal_path = match_strdup(&args[0]);
2086 		if (!journal_path) {
2087 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2088 				"journal device string");
2089 			return -1;
2090 		}
2091 
2092 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2093 		if (error) {
2094 			ext4_msg(sb, KERN_ERR, "error: could not find "
2095 				"journal device path: error %d", error);
2096 			kfree(journal_path);
2097 			return -1;
2098 		}
2099 
2100 		journal_inode = d_inode(path.dentry);
2101 		if (!S_ISBLK(journal_inode->i_mode)) {
2102 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2103 				"is not a block device", journal_path);
2104 			path_put(&path);
2105 			kfree(journal_path);
2106 			return -1;
2107 		}
2108 
2109 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2110 		path_put(&path);
2111 		kfree(journal_path);
2112 	} else if (token == Opt_journal_ioprio) {
2113 		if (arg > 7) {
2114 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2115 				 " (must be 0-7)");
2116 			return -1;
2117 		}
2118 		*journal_ioprio =
2119 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2120 	} else if (token == Opt_test_dummy_encryption) {
2121 		return ext4_set_test_dummy_encryption(sb, opt, &args[0],
2122 						      is_remount);
2123 	} else if (m->flags & MOPT_DATAJ) {
2124 		if (is_remount) {
2125 			if (!sbi->s_journal)
2126 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2127 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2128 				ext4_msg(sb, KERN_ERR,
2129 					 "Cannot change data mode on remount");
2130 				return -1;
2131 			}
2132 		} else {
2133 			clear_opt(sb, DATA_FLAGS);
2134 			sbi->s_mount_opt |= m->mount_opt;
2135 		}
2136 #ifdef CONFIG_QUOTA
2137 	} else if (m->flags & MOPT_QFMT) {
2138 		if (sb_any_quota_loaded(sb) &&
2139 		    sbi->s_jquota_fmt != m->mount_opt) {
2140 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2141 				 "quota options when quota turned on");
2142 			return -1;
2143 		}
2144 		if (ext4_has_feature_quota(sb)) {
2145 			ext4_msg(sb, KERN_INFO,
2146 				 "Quota format mount options ignored "
2147 				 "when QUOTA feature is enabled");
2148 			return 1;
2149 		}
2150 		sbi->s_jquota_fmt = m->mount_opt;
2151 #endif
2152 	} else if (token == Opt_dax || token == Opt_dax_always ||
2153 		   token == Opt_dax_inode || token == Opt_dax_never) {
2154 #ifdef CONFIG_FS_DAX
2155 		switch (token) {
2156 		case Opt_dax:
2157 		case Opt_dax_always:
2158 			if (is_remount &&
2159 			    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2160 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2161 			fail_dax_change_remount:
2162 				ext4_msg(sb, KERN_ERR, "can't change "
2163 					 "dax mount option while remounting");
2164 				return -1;
2165 			}
2166 			if (is_remount &&
2167 			    (test_opt(sb, DATA_FLAGS) ==
2168 			     EXT4_MOUNT_JOURNAL_DATA)) {
2169 				    ext4_msg(sb, KERN_ERR, "can't mount with "
2170 					     "both data=journal and dax");
2171 				    return -1;
2172 			}
2173 			ext4_msg(sb, KERN_WARNING,
2174 				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2175 			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
2176 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2177 			break;
2178 		case Opt_dax_never:
2179 			if (is_remount &&
2180 			    (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2181 			     (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS)))
2182 				goto fail_dax_change_remount;
2183 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2184 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2185 			break;
2186 		case Opt_dax_inode:
2187 			if (is_remount &&
2188 			    ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2189 			     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2190 			     !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE)))
2191 				goto fail_dax_change_remount;
2192 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2193 			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
2194 			/* Strictly for printing options */
2195 			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
2196 			break;
2197 		}
2198 #else
2199 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2200 		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
2201 		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
2202 		return -1;
2203 #endif
2204 	} else if (token == Opt_data_err_abort) {
2205 		sbi->s_mount_opt |= m->mount_opt;
2206 	} else if (token == Opt_data_err_ignore) {
2207 		sbi->s_mount_opt &= ~m->mount_opt;
2208 	} else {
2209 		if (!args->from)
2210 			arg = 1;
2211 		if (m->flags & MOPT_CLEAR)
2212 			arg = !arg;
2213 		else if (unlikely(!(m->flags & MOPT_SET))) {
2214 			ext4_msg(sb, KERN_WARNING,
2215 				 "buggy handling of option %s", opt);
2216 			WARN_ON(1);
2217 			return -1;
2218 		}
2219 		if (arg != 0)
2220 			sbi->s_mount_opt |= m->mount_opt;
2221 		else
2222 			sbi->s_mount_opt &= ~m->mount_opt;
2223 	}
2224 	return 1;
2225 }
2226 
2227 static int parse_options(char *options, struct super_block *sb,
2228 			 unsigned long *journal_devnum,
2229 			 unsigned int *journal_ioprio,
2230 			 int is_remount)
2231 {
2232 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2233 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2234 	substring_t args[MAX_OPT_ARGS];
2235 	int token;
2236 
2237 	if (!options)
2238 		return 1;
2239 
2240 	while ((p = strsep(&options, ",")) != NULL) {
2241 		if (!*p)
2242 			continue;
2243 		/*
2244 		 * Initialize args struct so we know whether arg was
2245 		 * found; some options take optional arguments.
2246 		 */
2247 		args[0].to = args[0].from = NULL;
2248 		token = match_token(p, tokens, args);
2249 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2250 				     journal_ioprio, is_remount) < 0)
2251 			return 0;
2252 	}
2253 #ifdef CONFIG_QUOTA
2254 	/*
2255 	 * We do the test below only for project quotas. 'usrquota' and
2256 	 * 'grpquota' mount options are allowed even without quota feature
2257 	 * to support legacy quotas in quota files.
2258 	 */
2259 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2260 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2261 			 "Cannot enable project quota enforcement.");
2262 		return 0;
2263 	}
2264 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2265 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2266 	if (usr_qf_name || grp_qf_name) {
2267 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2268 			clear_opt(sb, USRQUOTA);
2269 
2270 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2271 			clear_opt(sb, GRPQUOTA);
2272 
2273 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2274 			ext4_msg(sb, KERN_ERR, "old and new quota "
2275 					"format mixing");
2276 			return 0;
2277 		}
2278 
2279 		if (!sbi->s_jquota_fmt) {
2280 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2281 					"not specified");
2282 			return 0;
2283 		}
2284 	}
2285 #endif
2286 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2287 		int blocksize =
2288 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2289 		if (blocksize < PAGE_SIZE)
2290 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2291 				 "experimental mount option 'dioread_nolock' "
2292 				 "for blocksize < PAGE_SIZE");
2293 	}
2294 	return 1;
2295 }
2296 
2297 static inline void ext4_show_quota_options(struct seq_file *seq,
2298 					   struct super_block *sb)
2299 {
2300 #if defined(CONFIG_QUOTA)
2301 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2302 	char *usr_qf_name, *grp_qf_name;
2303 
2304 	if (sbi->s_jquota_fmt) {
2305 		char *fmtname = "";
2306 
2307 		switch (sbi->s_jquota_fmt) {
2308 		case QFMT_VFS_OLD:
2309 			fmtname = "vfsold";
2310 			break;
2311 		case QFMT_VFS_V0:
2312 			fmtname = "vfsv0";
2313 			break;
2314 		case QFMT_VFS_V1:
2315 			fmtname = "vfsv1";
2316 			break;
2317 		}
2318 		seq_printf(seq, ",jqfmt=%s", fmtname);
2319 	}
2320 
2321 	rcu_read_lock();
2322 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2323 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2324 	if (usr_qf_name)
2325 		seq_show_option(seq, "usrjquota", usr_qf_name);
2326 	if (grp_qf_name)
2327 		seq_show_option(seq, "grpjquota", grp_qf_name);
2328 	rcu_read_unlock();
2329 #endif
2330 }
2331 
2332 static const char *token2str(int token)
2333 {
2334 	const struct match_token *t;
2335 
2336 	for (t = tokens; t->token != Opt_err; t++)
2337 		if (t->token == token && !strchr(t->pattern, '='))
2338 			break;
2339 	return t->pattern;
2340 }
2341 
2342 /*
2343  * Show an option if
2344  *  - it's set to a non-default value OR
2345  *  - if the per-sb default is different from the global default
2346  */
2347 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2348 			      int nodefs)
2349 {
2350 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2351 	struct ext4_super_block *es = sbi->s_es;
2352 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2353 	const struct mount_opts *m;
2354 	char sep = nodefs ? '\n' : ',';
2355 
2356 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2357 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2358 
2359 	if (sbi->s_sb_block != 1)
2360 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2361 
2362 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2363 		int want_set = m->flags & MOPT_SET;
2364 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2365 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
2366 			continue;
2367 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2368 			continue; /* skip if same as the default */
2369 		if ((want_set &&
2370 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2371 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2372 			continue; /* select Opt_noFoo vs Opt_Foo */
2373 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2374 	}
2375 
2376 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2377 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2378 		SEQ_OPTS_PRINT("resuid=%u",
2379 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2380 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2381 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2382 		SEQ_OPTS_PRINT("resgid=%u",
2383 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2384 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2385 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2386 		SEQ_OPTS_PUTS("errors=remount-ro");
2387 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2388 		SEQ_OPTS_PUTS("errors=continue");
2389 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2390 		SEQ_OPTS_PUTS("errors=panic");
2391 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2392 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2393 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2394 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2395 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2396 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2397 	if (sb->s_flags & SB_I_VERSION)
2398 		SEQ_OPTS_PUTS("i_version");
2399 	if (nodefs || sbi->s_stripe)
2400 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2401 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2402 			(sbi->s_mount_opt ^ def_mount_opt)) {
2403 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2404 			SEQ_OPTS_PUTS("data=journal");
2405 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2406 			SEQ_OPTS_PUTS("data=ordered");
2407 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2408 			SEQ_OPTS_PUTS("data=writeback");
2409 	}
2410 	if (nodefs ||
2411 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2412 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2413 			       sbi->s_inode_readahead_blks);
2414 
2415 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2416 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2417 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2418 	if (nodefs || sbi->s_max_dir_size_kb)
2419 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2420 	if (test_opt(sb, DATA_ERR_ABORT))
2421 		SEQ_OPTS_PUTS("data_err=abort");
2422 
2423 	fscrypt_show_test_dummy_encryption(seq, sep, sb);
2424 
2425 	if (sb->s_flags & SB_INLINECRYPT)
2426 		SEQ_OPTS_PUTS("inlinecrypt");
2427 
2428 	if (test_opt(sb, DAX_ALWAYS)) {
2429 		if (IS_EXT2_SB(sb))
2430 			SEQ_OPTS_PUTS("dax");
2431 		else
2432 			SEQ_OPTS_PUTS("dax=always");
2433 	} else if (test_opt2(sb, DAX_NEVER)) {
2434 		SEQ_OPTS_PUTS("dax=never");
2435 	} else if (test_opt2(sb, DAX_INODE)) {
2436 		SEQ_OPTS_PUTS("dax=inode");
2437 	}
2438 
2439 	ext4_show_quota_options(seq, sb);
2440 	return 0;
2441 }
2442 
2443 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2444 {
2445 	return _ext4_show_options(seq, root->d_sb, 0);
2446 }
2447 
2448 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2449 {
2450 	struct super_block *sb = seq->private;
2451 	int rc;
2452 
2453 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2454 	rc = _ext4_show_options(seq, sb, 1);
2455 	seq_puts(seq, "\n");
2456 	return rc;
2457 }
2458 
2459 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2460 			    int read_only)
2461 {
2462 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2463 	int err = 0;
2464 
2465 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2466 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2467 			 "forcing read-only mode");
2468 		err = -EROFS;
2469 		goto done;
2470 	}
2471 	if (read_only)
2472 		goto done;
2473 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2474 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2475 			 "running e2fsck is recommended");
2476 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2477 		ext4_msg(sb, KERN_WARNING,
2478 			 "warning: mounting fs with errors, "
2479 			 "running e2fsck is recommended");
2480 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2481 		 le16_to_cpu(es->s_mnt_count) >=
2482 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2483 		ext4_msg(sb, KERN_WARNING,
2484 			 "warning: maximal mount count reached, "
2485 			 "running e2fsck is recommended");
2486 	else if (le32_to_cpu(es->s_checkinterval) &&
2487 		 (ext4_get_tstamp(es, s_lastcheck) +
2488 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2489 		ext4_msg(sb, KERN_WARNING,
2490 			 "warning: checktime reached, "
2491 			 "running e2fsck is recommended");
2492 	if (!sbi->s_journal)
2493 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2494 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2495 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2496 	le16_add_cpu(&es->s_mnt_count, 1);
2497 	ext4_update_tstamp(es, s_mtime);
2498 	if (sbi->s_journal)
2499 		ext4_set_feature_journal_needs_recovery(sb);
2500 
2501 	err = ext4_commit_super(sb, 1);
2502 done:
2503 	if (test_opt(sb, DEBUG))
2504 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2505 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2506 			sb->s_blocksize,
2507 			sbi->s_groups_count,
2508 			EXT4_BLOCKS_PER_GROUP(sb),
2509 			EXT4_INODES_PER_GROUP(sb),
2510 			sbi->s_mount_opt, sbi->s_mount_opt2);
2511 
2512 	cleancache_init_fs(sb);
2513 	return err;
2514 }
2515 
2516 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2517 {
2518 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2519 	struct flex_groups **old_groups, **new_groups;
2520 	int size, i, j;
2521 
2522 	if (!sbi->s_log_groups_per_flex)
2523 		return 0;
2524 
2525 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2526 	if (size <= sbi->s_flex_groups_allocated)
2527 		return 0;
2528 
2529 	new_groups = kvzalloc(roundup_pow_of_two(size *
2530 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2531 	if (!new_groups) {
2532 		ext4_msg(sb, KERN_ERR,
2533 			 "not enough memory for %d flex group pointers", size);
2534 		return -ENOMEM;
2535 	}
2536 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2537 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2538 					 sizeof(struct flex_groups)),
2539 					 GFP_KERNEL);
2540 		if (!new_groups[i]) {
2541 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2542 				kvfree(new_groups[j]);
2543 			kvfree(new_groups);
2544 			ext4_msg(sb, KERN_ERR,
2545 				 "not enough memory for %d flex groups", size);
2546 			return -ENOMEM;
2547 		}
2548 	}
2549 	rcu_read_lock();
2550 	old_groups = rcu_dereference(sbi->s_flex_groups);
2551 	if (old_groups)
2552 		memcpy(new_groups, old_groups,
2553 		       (sbi->s_flex_groups_allocated *
2554 			sizeof(struct flex_groups *)));
2555 	rcu_read_unlock();
2556 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2557 	sbi->s_flex_groups_allocated = size;
2558 	if (old_groups)
2559 		ext4_kvfree_array_rcu(old_groups);
2560 	return 0;
2561 }
2562 
2563 static int ext4_fill_flex_info(struct super_block *sb)
2564 {
2565 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2566 	struct ext4_group_desc *gdp = NULL;
2567 	struct flex_groups *fg;
2568 	ext4_group_t flex_group;
2569 	int i, err;
2570 
2571 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2572 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2573 		sbi->s_log_groups_per_flex = 0;
2574 		return 1;
2575 	}
2576 
2577 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2578 	if (err)
2579 		goto failed;
2580 
2581 	for (i = 0; i < sbi->s_groups_count; i++) {
2582 		gdp = ext4_get_group_desc(sb, i, NULL);
2583 
2584 		flex_group = ext4_flex_group(sbi, i);
2585 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2586 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2587 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2588 			     &fg->free_clusters);
2589 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2590 	}
2591 
2592 	return 1;
2593 failed:
2594 	return 0;
2595 }
2596 
2597 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2598 				   struct ext4_group_desc *gdp)
2599 {
2600 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2601 	__u16 crc = 0;
2602 	__le32 le_group = cpu_to_le32(block_group);
2603 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2604 
2605 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2606 		/* Use new metadata_csum algorithm */
2607 		__u32 csum32;
2608 		__u16 dummy_csum = 0;
2609 
2610 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2611 				     sizeof(le_group));
2612 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2613 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2614 				     sizeof(dummy_csum));
2615 		offset += sizeof(dummy_csum);
2616 		if (offset < sbi->s_desc_size)
2617 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2618 					     sbi->s_desc_size - offset);
2619 
2620 		crc = csum32 & 0xFFFF;
2621 		goto out;
2622 	}
2623 
2624 	/* old crc16 code */
2625 	if (!ext4_has_feature_gdt_csum(sb))
2626 		return 0;
2627 
2628 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2629 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2630 	crc = crc16(crc, (__u8 *)gdp, offset);
2631 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2632 	/* for checksum of struct ext4_group_desc do the rest...*/
2633 	if (ext4_has_feature_64bit(sb) &&
2634 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2635 		crc = crc16(crc, (__u8 *)gdp + offset,
2636 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2637 				offset);
2638 
2639 out:
2640 	return cpu_to_le16(crc);
2641 }
2642 
2643 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2644 				struct ext4_group_desc *gdp)
2645 {
2646 	if (ext4_has_group_desc_csum(sb) &&
2647 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2648 		return 0;
2649 
2650 	return 1;
2651 }
2652 
2653 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2654 			      struct ext4_group_desc *gdp)
2655 {
2656 	if (!ext4_has_group_desc_csum(sb))
2657 		return;
2658 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2659 }
2660 
2661 /* Called at mount-time, super-block is locked */
2662 static int ext4_check_descriptors(struct super_block *sb,
2663 				  ext4_fsblk_t sb_block,
2664 				  ext4_group_t *first_not_zeroed)
2665 {
2666 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2667 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2668 	ext4_fsblk_t last_block;
2669 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2670 	ext4_fsblk_t block_bitmap;
2671 	ext4_fsblk_t inode_bitmap;
2672 	ext4_fsblk_t inode_table;
2673 	int flexbg_flag = 0;
2674 	ext4_group_t i, grp = sbi->s_groups_count;
2675 
2676 	if (ext4_has_feature_flex_bg(sb))
2677 		flexbg_flag = 1;
2678 
2679 	ext4_debug("Checking group descriptors");
2680 
2681 	for (i = 0; i < sbi->s_groups_count; i++) {
2682 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2683 
2684 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2685 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2686 		else
2687 			last_block = first_block +
2688 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2689 
2690 		if ((grp == sbi->s_groups_count) &&
2691 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2692 			grp = i;
2693 
2694 		block_bitmap = ext4_block_bitmap(sb, gdp);
2695 		if (block_bitmap == sb_block) {
2696 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2697 				 "Block bitmap for group %u overlaps "
2698 				 "superblock", i);
2699 			if (!sb_rdonly(sb))
2700 				return 0;
2701 		}
2702 		if (block_bitmap >= sb_block + 1 &&
2703 		    block_bitmap <= last_bg_block) {
2704 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2705 				 "Block bitmap for group %u overlaps "
2706 				 "block group descriptors", i);
2707 			if (!sb_rdonly(sb))
2708 				return 0;
2709 		}
2710 		if (block_bitmap < first_block || block_bitmap > last_block) {
2711 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2712 			       "Block bitmap for group %u not in group "
2713 			       "(block %llu)!", i, block_bitmap);
2714 			return 0;
2715 		}
2716 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2717 		if (inode_bitmap == sb_block) {
2718 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2719 				 "Inode bitmap for group %u overlaps "
2720 				 "superblock", i);
2721 			if (!sb_rdonly(sb))
2722 				return 0;
2723 		}
2724 		if (inode_bitmap >= sb_block + 1 &&
2725 		    inode_bitmap <= last_bg_block) {
2726 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2727 				 "Inode bitmap for group %u overlaps "
2728 				 "block group descriptors", i);
2729 			if (!sb_rdonly(sb))
2730 				return 0;
2731 		}
2732 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2733 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2734 			       "Inode bitmap for group %u not in group "
2735 			       "(block %llu)!", i, inode_bitmap);
2736 			return 0;
2737 		}
2738 		inode_table = ext4_inode_table(sb, gdp);
2739 		if (inode_table == sb_block) {
2740 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2741 				 "Inode table for group %u overlaps "
2742 				 "superblock", i);
2743 			if (!sb_rdonly(sb))
2744 				return 0;
2745 		}
2746 		if (inode_table >= sb_block + 1 &&
2747 		    inode_table <= last_bg_block) {
2748 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2749 				 "Inode table for group %u overlaps "
2750 				 "block group descriptors", i);
2751 			if (!sb_rdonly(sb))
2752 				return 0;
2753 		}
2754 		if (inode_table < first_block ||
2755 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2756 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2757 			       "Inode table for group %u not in group "
2758 			       "(block %llu)!", i, inode_table);
2759 			return 0;
2760 		}
2761 		ext4_lock_group(sb, i);
2762 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2763 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2764 				 "Checksum for group %u failed (%u!=%u)",
2765 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2766 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2767 			if (!sb_rdonly(sb)) {
2768 				ext4_unlock_group(sb, i);
2769 				return 0;
2770 			}
2771 		}
2772 		ext4_unlock_group(sb, i);
2773 		if (!flexbg_flag)
2774 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2775 	}
2776 	if (NULL != first_not_zeroed)
2777 		*first_not_zeroed = grp;
2778 	return 1;
2779 }
2780 
2781 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2782  * the superblock) which were deleted from all directories, but held open by
2783  * a process at the time of a crash.  We walk the list and try to delete these
2784  * inodes at recovery time (only with a read-write filesystem).
2785  *
2786  * In order to keep the orphan inode chain consistent during traversal (in
2787  * case of crash during recovery), we link each inode into the superblock
2788  * orphan list_head and handle it the same way as an inode deletion during
2789  * normal operation (which journals the operations for us).
2790  *
2791  * We only do an iget() and an iput() on each inode, which is very safe if we
2792  * accidentally point at an in-use or already deleted inode.  The worst that
2793  * can happen in this case is that we get a "bit already cleared" message from
2794  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2795  * e2fsck was run on this filesystem, and it must have already done the orphan
2796  * inode cleanup for us, so we can safely abort without any further action.
2797  */
2798 static void ext4_orphan_cleanup(struct super_block *sb,
2799 				struct ext4_super_block *es)
2800 {
2801 	unsigned int s_flags = sb->s_flags;
2802 	int ret, nr_orphans = 0, nr_truncates = 0;
2803 #ifdef CONFIG_QUOTA
2804 	int quota_update = 0;
2805 	int i;
2806 #endif
2807 	if (!es->s_last_orphan) {
2808 		jbd_debug(4, "no orphan inodes to clean up\n");
2809 		return;
2810 	}
2811 
2812 	if (bdev_read_only(sb->s_bdev)) {
2813 		ext4_msg(sb, KERN_ERR, "write access "
2814 			"unavailable, skipping orphan cleanup");
2815 		return;
2816 	}
2817 
2818 	/* Check if feature set would not allow a r/w mount */
2819 	if (!ext4_feature_set_ok(sb, 0)) {
2820 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2821 			 "unknown ROCOMPAT features");
2822 		return;
2823 	}
2824 
2825 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2826 		/* don't clear list on RO mount w/ errors */
2827 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2828 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2829 				  "clearing orphan list.\n");
2830 			es->s_last_orphan = 0;
2831 		}
2832 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2833 		return;
2834 	}
2835 
2836 	if (s_flags & SB_RDONLY) {
2837 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2838 		sb->s_flags &= ~SB_RDONLY;
2839 	}
2840 #ifdef CONFIG_QUOTA
2841 	/* Needed for iput() to work correctly and not trash data */
2842 	sb->s_flags |= SB_ACTIVE;
2843 
2844 	/*
2845 	 * Turn on quotas which were not enabled for read-only mounts if
2846 	 * filesystem has quota feature, so that they are updated correctly.
2847 	 */
2848 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2849 		int ret = ext4_enable_quotas(sb);
2850 
2851 		if (!ret)
2852 			quota_update = 1;
2853 		else
2854 			ext4_msg(sb, KERN_ERR,
2855 				"Cannot turn on quotas: error %d", ret);
2856 	}
2857 
2858 	/* Turn on journaled quotas used for old sytle */
2859 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2860 		if (EXT4_SB(sb)->s_qf_names[i]) {
2861 			int ret = ext4_quota_on_mount(sb, i);
2862 
2863 			if (!ret)
2864 				quota_update = 1;
2865 			else
2866 				ext4_msg(sb, KERN_ERR,
2867 					"Cannot turn on journaled "
2868 					"quota: type %d: error %d", i, ret);
2869 		}
2870 	}
2871 #endif
2872 
2873 	while (es->s_last_orphan) {
2874 		struct inode *inode;
2875 
2876 		/*
2877 		 * We may have encountered an error during cleanup; if
2878 		 * so, skip the rest.
2879 		 */
2880 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2881 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2882 			es->s_last_orphan = 0;
2883 			break;
2884 		}
2885 
2886 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2887 		if (IS_ERR(inode)) {
2888 			es->s_last_orphan = 0;
2889 			break;
2890 		}
2891 
2892 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2893 		dquot_initialize(inode);
2894 		if (inode->i_nlink) {
2895 			if (test_opt(sb, DEBUG))
2896 				ext4_msg(sb, KERN_DEBUG,
2897 					"%s: truncating inode %lu to %lld bytes",
2898 					__func__, inode->i_ino, inode->i_size);
2899 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2900 				  inode->i_ino, inode->i_size);
2901 			inode_lock(inode);
2902 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2903 			ret = ext4_truncate(inode);
2904 			if (ret)
2905 				ext4_std_error(inode->i_sb, ret);
2906 			inode_unlock(inode);
2907 			nr_truncates++;
2908 		} else {
2909 			if (test_opt(sb, DEBUG))
2910 				ext4_msg(sb, KERN_DEBUG,
2911 					"%s: deleting unreferenced inode %lu",
2912 					__func__, inode->i_ino);
2913 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2914 				  inode->i_ino);
2915 			nr_orphans++;
2916 		}
2917 		iput(inode);  /* The delete magic happens here! */
2918 	}
2919 
2920 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2921 
2922 	if (nr_orphans)
2923 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2924 		       PLURAL(nr_orphans));
2925 	if (nr_truncates)
2926 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2927 		       PLURAL(nr_truncates));
2928 #ifdef CONFIG_QUOTA
2929 	/* Turn off quotas if they were enabled for orphan cleanup */
2930 	if (quota_update) {
2931 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2932 			if (sb_dqopt(sb)->files[i])
2933 				dquot_quota_off(sb, i);
2934 		}
2935 	}
2936 #endif
2937 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2938 }
2939 
2940 /*
2941  * Maximal extent format file size.
2942  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2943  * extent format containers, within a sector_t, and within i_blocks
2944  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2945  * so that won't be a limiting factor.
2946  *
2947  * However there is other limiting factor. We do store extents in the form
2948  * of starting block and length, hence the resulting length of the extent
2949  * covering maximum file size must fit into on-disk format containers as
2950  * well. Given that length is always by 1 unit bigger than max unit (because
2951  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2952  *
2953  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2954  */
2955 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2956 {
2957 	loff_t res;
2958 	loff_t upper_limit = MAX_LFS_FILESIZE;
2959 
2960 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2961 
2962 	if (!has_huge_files) {
2963 		upper_limit = (1LL << 32) - 1;
2964 
2965 		/* total blocks in file system block size */
2966 		upper_limit >>= (blkbits - 9);
2967 		upper_limit <<= blkbits;
2968 	}
2969 
2970 	/*
2971 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2972 	 * by one fs block, so ee_len can cover the extent of maximum file
2973 	 * size
2974 	 */
2975 	res = (1LL << 32) - 1;
2976 	res <<= blkbits;
2977 
2978 	/* Sanity check against vm- & vfs- imposed limits */
2979 	if (res > upper_limit)
2980 		res = upper_limit;
2981 
2982 	return res;
2983 }
2984 
2985 /*
2986  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2987  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2988  * We need to be 1 filesystem block less than the 2^48 sector limit.
2989  */
2990 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2991 {
2992 	loff_t res = EXT4_NDIR_BLOCKS;
2993 	int meta_blocks;
2994 	loff_t upper_limit;
2995 	/* This is calculated to be the largest file size for a dense, block
2996 	 * mapped file such that the file's total number of 512-byte sectors,
2997 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2998 	 *
2999 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3000 	 * number of 512-byte sectors of the file.
3001 	 */
3002 
3003 	if (!has_huge_files) {
3004 		/*
3005 		 * !has_huge_files or implies that the inode i_block field
3006 		 * represents total file blocks in 2^32 512-byte sectors ==
3007 		 * size of vfs inode i_blocks * 8
3008 		 */
3009 		upper_limit = (1LL << 32) - 1;
3010 
3011 		/* total blocks in file system block size */
3012 		upper_limit >>= (bits - 9);
3013 
3014 	} else {
3015 		/*
3016 		 * We use 48 bit ext4_inode i_blocks
3017 		 * With EXT4_HUGE_FILE_FL set the i_blocks
3018 		 * represent total number of blocks in
3019 		 * file system block size
3020 		 */
3021 		upper_limit = (1LL << 48) - 1;
3022 
3023 	}
3024 
3025 	/* indirect blocks */
3026 	meta_blocks = 1;
3027 	/* double indirect blocks */
3028 	meta_blocks += 1 + (1LL << (bits-2));
3029 	/* tripple indirect blocks */
3030 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3031 
3032 	upper_limit -= meta_blocks;
3033 	upper_limit <<= bits;
3034 
3035 	res += 1LL << (bits-2);
3036 	res += 1LL << (2*(bits-2));
3037 	res += 1LL << (3*(bits-2));
3038 	res <<= bits;
3039 	if (res > upper_limit)
3040 		res = upper_limit;
3041 
3042 	if (res > MAX_LFS_FILESIZE)
3043 		res = MAX_LFS_FILESIZE;
3044 
3045 	return res;
3046 }
3047 
3048 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3049 				   ext4_fsblk_t logical_sb_block, int nr)
3050 {
3051 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3052 	ext4_group_t bg, first_meta_bg;
3053 	int has_super = 0;
3054 
3055 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3056 
3057 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3058 		return logical_sb_block + nr + 1;
3059 	bg = sbi->s_desc_per_block * nr;
3060 	if (ext4_bg_has_super(sb, bg))
3061 		has_super = 1;
3062 
3063 	/*
3064 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3065 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3066 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3067 	 * compensate.
3068 	 */
3069 	if (sb->s_blocksize == 1024 && nr == 0 &&
3070 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3071 		has_super++;
3072 
3073 	return (has_super + ext4_group_first_block_no(sb, bg));
3074 }
3075 
3076 /**
3077  * ext4_get_stripe_size: Get the stripe size.
3078  * @sbi: In memory super block info
3079  *
3080  * If we have specified it via mount option, then
3081  * use the mount option value. If the value specified at mount time is
3082  * greater than the blocks per group use the super block value.
3083  * If the super block value is greater than blocks per group return 0.
3084  * Allocator needs it be less than blocks per group.
3085  *
3086  */
3087 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3088 {
3089 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3090 	unsigned long stripe_width =
3091 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3092 	int ret;
3093 
3094 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3095 		ret = sbi->s_stripe;
3096 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3097 		ret = stripe_width;
3098 	else if (stride && stride <= sbi->s_blocks_per_group)
3099 		ret = stride;
3100 	else
3101 		ret = 0;
3102 
3103 	/*
3104 	 * If the stripe width is 1, this makes no sense and
3105 	 * we set it to 0 to turn off stripe handling code.
3106 	 */
3107 	if (ret <= 1)
3108 		ret = 0;
3109 
3110 	return ret;
3111 }
3112 
3113 /*
3114  * Check whether this filesystem can be mounted based on
3115  * the features present and the RDONLY/RDWR mount requested.
3116  * Returns 1 if this filesystem can be mounted as requested,
3117  * 0 if it cannot be.
3118  */
3119 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
3120 {
3121 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
3122 		ext4_msg(sb, KERN_ERR,
3123 			"Couldn't mount because of "
3124 			"unsupported optional features (%x)",
3125 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3126 			~EXT4_FEATURE_INCOMPAT_SUPP));
3127 		return 0;
3128 	}
3129 
3130 #ifndef CONFIG_UNICODE
3131 	if (ext4_has_feature_casefold(sb)) {
3132 		ext4_msg(sb, KERN_ERR,
3133 			 "Filesystem with casefold feature cannot be "
3134 			 "mounted without CONFIG_UNICODE");
3135 		return 0;
3136 	}
3137 #endif
3138 
3139 	if (readonly)
3140 		return 1;
3141 
3142 	if (ext4_has_feature_readonly(sb)) {
3143 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3144 		sb->s_flags |= SB_RDONLY;
3145 		return 1;
3146 	}
3147 
3148 	/* Check that feature set is OK for a read-write mount */
3149 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3150 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3151 			 "unsupported optional features (%x)",
3152 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3153 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3154 		return 0;
3155 	}
3156 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3157 		ext4_msg(sb, KERN_ERR,
3158 			 "Can't support bigalloc feature without "
3159 			 "extents feature\n");
3160 		return 0;
3161 	}
3162 
3163 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3164 	if (!readonly && (ext4_has_feature_quota(sb) ||
3165 			  ext4_has_feature_project(sb))) {
3166 		ext4_msg(sb, KERN_ERR,
3167 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3168 		return 0;
3169 	}
3170 #endif  /* CONFIG_QUOTA */
3171 	return 1;
3172 }
3173 
3174 /*
3175  * This function is called once a day if we have errors logged
3176  * on the file system
3177  */
3178 static void print_daily_error_info(struct timer_list *t)
3179 {
3180 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3181 	struct super_block *sb = sbi->s_sb;
3182 	struct ext4_super_block *es = sbi->s_es;
3183 
3184 	if (es->s_error_count)
3185 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3186 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3187 			 le32_to_cpu(es->s_error_count));
3188 	if (es->s_first_error_time) {
3189 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3190 		       sb->s_id,
3191 		       ext4_get_tstamp(es, s_first_error_time),
3192 		       (int) sizeof(es->s_first_error_func),
3193 		       es->s_first_error_func,
3194 		       le32_to_cpu(es->s_first_error_line));
3195 		if (es->s_first_error_ino)
3196 			printk(KERN_CONT ": inode %u",
3197 			       le32_to_cpu(es->s_first_error_ino));
3198 		if (es->s_first_error_block)
3199 			printk(KERN_CONT ": block %llu", (unsigned long long)
3200 			       le64_to_cpu(es->s_first_error_block));
3201 		printk(KERN_CONT "\n");
3202 	}
3203 	if (es->s_last_error_time) {
3204 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3205 		       sb->s_id,
3206 		       ext4_get_tstamp(es, s_last_error_time),
3207 		       (int) sizeof(es->s_last_error_func),
3208 		       es->s_last_error_func,
3209 		       le32_to_cpu(es->s_last_error_line));
3210 		if (es->s_last_error_ino)
3211 			printk(KERN_CONT ": inode %u",
3212 			       le32_to_cpu(es->s_last_error_ino));
3213 		if (es->s_last_error_block)
3214 			printk(KERN_CONT ": block %llu", (unsigned long long)
3215 			       le64_to_cpu(es->s_last_error_block));
3216 		printk(KERN_CONT "\n");
3217 	}
3218 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3219 }
3220 
3221 /* Find next suitable group and run ext4_init_inode_table */
3222 static int ext4_run_li_request(struct ext4_li_request *elr)
3223 {
3224 	struct ext4_group_desc *gdp = NULL;
3225 	struct super_block *sb = elr->lr_super;
3226 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3227 	ext4_group_t group = elr->lr_next_group;
3228 	unsigned long timeout = 0;
3229 	unsigned int prefetch_ios = 0;
3230 	int ret = 0;
3231 
3232 	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3233 		elr->lr_next_group = ext4_mb_prefetch(sb, group,
3234 				EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3235 		if (prefetch_ios)
3236 			ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3237 					      prefetch_ios);
3238 		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3239 					    prefetch_ios);
3240 		if (group >= elr->lr_next_group) {
3241 			ret = 1;
3242 			if (elr->lr_first_not_zeroed != ngroups &&
3243 			    !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3244 				elr->lr_next_group = elr->lr_first_not_zeroed;
3245 				elr->lr_mode = EXT4_LI_MODE_ITABLE;
3246 				ret = 0;
3247 			}
3248 		}
3249 		return ret;
3250 	}
3251 
3252 	for (; group < ngroups; group++) {
3253 		gdp = ext4_get_group_desc(sb, group, NULL);
3254 		if (!gdp) {
3255 			ret = 1;
3256 			break;
3257 		}
3258 
3259 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3260 			break;
3261 	}
3262 
3263 	if (group >= ngroups)
3264 		ret = 1;
3265 
3266 	if (!ret) {
3267 		timeout = jiffies;
3268 		ret = ext4_init_inode_table(sb, group,
3269 					    elr->lr_timeout ? 0 : 1);
3270 		trace_ext4_lazy_itable_init(sb, group);
3271 		if (elr->lr_timeout == 0) {
3272 			timeout = (jiffies - timeout) *
3273 				EXT4_SB(elr->lr_super)->s_li_wait_mult;
3274 			elr->lr_timeout = timeout;
3275 		}
3276 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3277 		elr->lr_next_group = group + 1;
3278 	}
3279 	return ret;
3280 }
3281 
3282 /*
3283  * Remove lr_request from the list_request and free the
3284  * request structure. Should be called with li_list_mtx held
3285  */
3286 static void ext4_remove_li_request(struct ext4_li_request *elr)
3287 {
3288 	if (!elr)
3289 		return;
3290 
3291 	list_del(&elr->lr_request);
3292 	EXT4_SB(elr->lr_super)->s_li_request = NULL;
3293 	kfree(elr);
3294 }
3295 
3296 static void ext4_unregister_li_request(struct super_block *sb)
3297 {
3298 	mutex_lock(&ext4_li_mtx);
3299 	if (!ext4_li_info) {
3300 		mutex_unlock(&ext4_li_mtx);
3301 		return;
3302 	}
3303 
3304 	mutex_lock(&ext4_li_info->li_list_mtx);
3305 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3306 	mutex_unlock(&ext4_li_info->li_list_mtx);
3307 	mutex_unlock(&ext4_li_mtx);
3308 }
3309 
3310 static struct task_struct *ext4_lazyinit_task;
3311 
3312 /*
3313  * This is the function where ext4lazyinit thread lives. It walks
3314  * through the request list searching for next scheduled filesystem.
3315  * When such a fs is found, run the lazy initialization request
3316  * (ext4_rn_li_request) and keep track of the time spend in this
3317  * function. Based on that time we compute next schedule time of
3318  * the request. When walking through the list is complete, compute
3319  * next waking time and put itself into sleep.
3320  */
3321 static int ext4_lazyinit_thread(void *arg)
3322 {
3323 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3324 	struct list_head *pos, *n;
3325 	struct ext4_li_request *elr;
3326 	unsigned long next_wakeup, cur;
3327 
3328 	BUG_ON(NULL == eli);
3329 
3330 cont_thread:
3331 	while (true) {
3332 		next_wakeup = MAX_JIFFY_OFFSET;
3333 
3334 		mutex_lock(&eli->li_list_mtx);
3335 		if (list_empty(&eli->li_request_list)) {
3336 			mutex_unlock(&eli->li_list_mtx);
3337 			goto exit_thread;
3338 		}
3339 		list_for_each_safe(pos, n, &eli->li_request_list) {
3340 			int err = 0;
3341 			int progress = 0;
3342 			elr = list_entry(pos, struct ext4_li_request,
3343 					 lr_request);
3344 
3345 			if (time_before(jiffies, elr->lr_next_sched)) {
3346 				if (time_before(elr->lr_next_sched, next_wakeup))
3347 					next_wakeup = elr->lr_next_sched;
3348 				continue;
3349 			}
3350 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3351 				if (sb_start_write_trylock(elr->lr_super)) {
3352 					progress = 1;
3353 					/*
3354 					 * We hold sb->s_umount, sb can not
3355 					 * be removed from the list, it is
3356 					 * now safe to drop li_list_mtx
3357 					 */
3358 					mutex_unlock(&eli->li_list_mtx);
3359 					err = ext4_run_li_request(elr);
3360 					sb_end_write(elr->lr_super);
3361 					mutex_lock(&eli->li_list_mtx);
3362 					n = pos->next;
3363 				}
3364 				up_read((&elr->lr_super->s_umount));
3365 			}
3366 			/* error, remove the lazy_init job */
3367 			if (err) {
3368 				ext4_remove_li_request(elr);
3369 				continue;
3370 			}
3371 			if (!progress) {
3372 				elr->lr_next_sched = jiffies +
3373 					(prandom_u32()
3374 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3375 			}
3376 			if (time_before(elr->lr_next_sched, next_wakeup))
3377 				next_wakeup = elr->lr_next_sched;
3378 		}
3379 		mutex_unlock(&eli->li_list_mtx);
3380 
3381 		try_to_freeze();
3382 
3383 		cur = jiffies;
3384 		if ((time_after_eq(cur, next_wakeup)) ||
3385 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3386 			cond_resched();
3387 			continue;
3388 		}
3389 
3390 		schedule_timeout_interruptible(next_wakeup - cur);
3391 
3392 		if (kthread_should_stop()) {
3393 			ext4_clear_request_list();
3394 			goto exit_thread;
3395 		}
3396 	}
3397 
3398 exit_thread:
3399 	/*
3400 	 * It looks like the request list is empty, but we need
3401 	 * to check it under the li_list_mtx lock, to prevent any
3402 	 * additions into it, and of course we should lock ext4_li_mtx
3403 	 * to atomically free the list and ext4_li_info, because at
3404 	 * this point another ext4 filesystem could be registering
3405 	 * new one.
3406 	 */
3407 	mutex_lock(&ext4_li_mtx);
3408 	mutex_lock(&eli->li_list_mtx);
3409 	if (!list_empty(&eli->li_request_list)) {
3410 		mutex_unlock(&eli->li_list_mtx);
3411 		mutex_unlock(&ext4_li_mtx);
3412 		goto cont_thread;
3413 	}
3414 	mutex_unlock(&eli->li_list_mtx);
3415 	kfree(ext4_li_info);
3416 	ext4_li_info = NULL;
3417 	mutex_unlock(&ext4_li_mtx);
3418 
3419 	return 0;
3420 }
3421 
3422 static void ext4_clear_request_list(void)
3423 {
3424 	struct list_head *pos, *n;
3425 	struct ext4_li_request *elr;
3426 
3427 	mutex_lock(&ext4_li_info->li_list_mtx);
3428 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3429 		elr = list_entry(pos, struct ext4_li_request,
3430 				 lr_request);
3431 		ext4_remove_li_request(elr);
3432 	}
3433 	mutex_unlock(&ext4_li_info->li_list_mtx);
3434 }
3435 
3436 static int ext4_run_lazyinit_thread(void)
3437 {
3438 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3439 					 ext4_li_info, "ext4lazyinit");
3440 	if (IS_ERR(ext4_lazyinit_task)) {
3441 		int err = PTR_ERR(ext4_lazyinit_task);
3442 		ext4_clear_request_list();
3443 		kfree(ext4_li_info);
3444 		ext4_li_info = NULL;
3445 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3446 				 "initialization thread\n",
3447 				 err);
3448 		return err;
3449 	}
3450 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3451 	return 0;
3452 }
3453 
3454 /*
3455  * Check whether it make sense to run itable init. thread or not.
3456  * If there is at least one uninitialized inode table, return
3457  * corresponding group number, else the loop goes through all
3458  * groups and return total number of groups.
3459  */
3460 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3461 {
3462 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3463 	struct ext4_group_desc *gdp = NULL;
3464 
3465 	if (!ext4_has_group_desc_csum(sb))
3466 		return ngroups;
3467 
3468 	for (group = 0; group < ngroups; group++) {
3469 		gdp = ext4_get_group_desc(sb, group, NULL);
3470 		if (!gdp)
3471 			continue;
3472 
3473 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3474 			break;
3475 	}
3476 
3477 	return group;
3478 }
3479 
3480 static int ext4_li_info_new(void)
3481 {
3482 	struct ext4_lazy_init *eli = NULL;
3483 
3484 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3485 	if (!eli)
3486 		return -ENOMEM;
3487 
3488 	INIT_LIST_HEAD(&eli->li_request_list);
3489 	mutex_init(&eli->li_list_mtx);
3490 
3491 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3492 
3493 	ext4_li_info = eli;
3494 
3495 	return 0;
3496 }
3497 
3498 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3499 					    ext4_group_t start)
3500 {
3501 	struct ext4_li_request *elr;
3502 
3503 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3504 	if (!elr)
3505 		return NULL;
3506 
3507 	elr->lr_super = sb;
3508 	elr->lr_first_not_zeroed = start;
3509 	if (test_opt(sb, PREFETCH_BLOCK_BITMAPS))
3510 		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3511 	else {
3512 		elr->lr_mode = EXT4_LI_MODE_ITABLE;
3513 		elr->lr_next_group = start;
3514 	}
3515 
3516 	/*
3517 	 * Randomize first schedule time of the request to
3518 	 * spread the inode table initialization requests
3519 	 * better.
3520 	 */
3521 	elr->lr_next_sched = jiffies + (prandom_u32() %
3522 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3523 	return elr;
3524 }
3525 
3526 int ext4_register_li_request(struct super_block *sb,
3527 			     ext4_group_t first_not_zeroed)
3528 {
3529 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3530 	struct ext4_li_request *elr = NULL;
3531 	ext4_group_t ngroups = sbi->s_groups_count;
3532 	int ret = 0;
3533 
3534 	mutex_lock(&ext4_li_mtx);
3535 	if (sbi->s_li_request != NULL) {
3536 		/*
3537 		 * Reset timeout so it can be computed again, because
3538 		 * s_li_wait_mult might have changed.
3539 		 */
3540 		sbi->s_li_request->lr_timeout = 0;
3541 		goto out;
3542 	}
3543 
3544 	if (!test_opt(sb, PREFETCH_BLOCK_BITMAPS) &&
3545 	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3546 	     !test_opt(sb, INIT_INODE_TABLE)))
3547 		goto out;
3548 
3549 	elr = ext4_li_request_new(sb, first_not_zeroed);
3550 	if (!elr) {
3551 		ret = -ENOMEM;
3552 		goto out;
3553 	}
3554 
3555 	if (NULL == ext4_li_info) {
3556 		ret = ext4_li_info_new();
3557 		if (ret)
3558 			goto out;
3559 	}
3560 
3561 	mutex_lock(&ext4_li_info->li_list_mtx);
3562 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3563 	mutex_unlock(&ext4_li_info->li_list_mtx);
3564 
3565 	sbi->s_li_request = elr;
3566 	/*
3567 	 * set elr to NULL here since it has been inserted to
3568 	 * the request_list and the removal and free of it is
3569 	 * handled by ext4_clear_request_list from now on.
3570 	 */
3571 	elr = NULL;
3572 
3573 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3574 		ret = ext4_run_lazyinit_thread();
3575 		if (ret)
3576 			goto out;
3577 	}
3578 out:
3579 	mutex_unlock(&ext4_li_mtx);
3580 	if (ret)
3581 		kfree(elr);
3582 	return ret;
3583 }
3584 
3585 /*
3586  * We do not need to lock anything since this is called on
3587  * module unload.
3588  */
3589 static void ext4_destroy_lazyinit_thread(void)
3590 {
3591 	/*
3592 	 * If thread exited earlier
3593 	 * there's nothing to be done.
3594 	 */
3595 	if (!ext4_li_info || !ext4_lazyinit_task)
3596 		return;
3597 
3598 	kthread_stop(ext4_lazyinit_task);
3599 }
3600 
3601 static int set_journal_csum_feature_set(struct super_block *sb)
3602 {
3603 	int ret = 1;
3604 	int compat, incompat;
3605 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3606 
3607 	if (ext4_has_metadata_csum(sb)) {
3608 		/* journal checksum v3 */
3609 		compat = 0;
3610 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3611 	} else {
3612 		/* journal checksum v1 */
3613 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3614 		incompat = 0;
3615 	}
3616 
3617 	jbd2_journal_clear_features(sbi->s_journal,
3618 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3619 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3620 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3621 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3622 		ret = jbd2_journal_set_features(sbi->s_journal,
3623 				compat, 0,
3624 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3625 				incompat);
3626 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3627 		ret = jbd2_journal_set_features(sbi->s_journal,
3628 				compat, 0,
3629 				incompat);
3630 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3631 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3632 	} else {
3633 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3634 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3635 	}
3636 
3637 	return ret;
3638 }
3639 
3640 /*
3641  * Note: calculating the overhead so we can be compatible with
3642  * historical BSD practice is quite difficult in the face of
3643  * clusters/bigalloc.  This is because multiple metadata blocks from
3644  * different block group can end up in the same allocation cluster.
3645  * Calculating the exact overhead in the face of clustered allocation
3646  * requires either O(all block bitmaps) in memory or O(number of block
3647  * groups**2) in time.  We will still calculate the superblock for
3648  * older file systems --- and if we come across with a bigalloc file
3649  * system with zero in s_overhead_clusters the estimate will be close to
3650  * correct especially for very large cluster sizes --- but for newer
3651  * file systems, it's better to calculate this figure once at mkfs
3652  * time, and store it in the superblock.  If the superblock value is
3653  * present (even for non-bigalloc file systems), we will use it.
3654  */
3655 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3656 			  char *buf)
3657 {
3658 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3659 	struct ext4_group_desc	*gdp;
3660 	ext4_fsblk_t		first_block, last_block, b;
3661 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3662 	int			s, j, count = 0;
3663 
3664 	if (!ext4_has_feature_bigalloc(sb))
3665 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3666 			sbi->s_itb_per_group + 2);
3667 
3668 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3669 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3670 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3671 	for (i = 0; i < ngroups; i++) {
3672 		gdp = ext4_get_group_desc(sb, i, NULL);
3673 		b = ext4_block_bitmap(sb, gdp);
3674 		if (b >= first_block && b <= last_block) {
3675 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3676 			count++;
3677 		}
3678 		b = ext4_inode_bitmap(sb, gdp);
3679 		if (b >= first_block && b <= last_block) {
3680 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3681 			count++;
3682 		}
3683 		b = ext4_inode_table(sb, gdp);
3684 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3685 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3686 				int c = EXT4_B2C(sbi, b - first_block);
3687 				ext4_set_bit(c, buf);
3688 				count++;
3689 			}
3690 		if (i != grp)
3691 			continue;
3692 		s = 0;
3693 		if (ext4_bg_has_super(sb, grp)) {
3694 			ext4_set_bit(s++, buf);
3695 			count++;
3696 		}
3697 		j = ext4_bg_num_gdb(sb, grp);
3698 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3699 			ext4_error(sb, "Invalid number of block group "
3700 				   "descriptor blocks: %d", j);
3701 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3702 		}
3703 		count += j;
3704 		for (; j > 0; j--)
3705 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3706 	}
3707 	if (!count)
3708 		return 0;
3709 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3710 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3711 }
3712 
3713 /*
3714  * Compute the overhead and stash it in sbi->s_overhead
3715  */
3716 int ext4_calculate_overhead(struct super_block *sb)
3717 {
3718 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3719 	struct ext4_super_block *es = sbi->s_es;
3720 	struct inode *j_inode;
3721 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3722 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3723 	ext4_fsblk_t overhead = 0;
3724 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3725 
3726 	if (!buf)
3727 		return -ENOMEM;
3728 
3729 	/*
3730 	 * Compute the overhead (FS structures).  This is constant
3731 	 * for a given filesystem unless the number of block groups
3732 	 * changes so we cache the previous value until it does.
3733 	 */
3734 
3735 	/*
3736 	 * All of the blocks before first_data_block are overhead
3737 	 */
3738 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3739 
3740 	/*
3741 	 * Add the overhead found in each block group
3742 	 */
3743 	for (i = 0; i < ngroups; i++) {
3744 		int blks;
3745 
3746 		blks = count_overhead(sb, i, buf);
3747 		overhead += blks;
3748 		if (blks)
3749 			memset(buf, 0, PAGE_SIZE);
3750 		cond_resched();
3751 	}
3752 
3753 	/*
3754 	 * Add the internal journal blocks whether the journal has been
3755 	 * loaded or not
3756 	 */
3757 	if (sbi->s_journal && !sbi->journal_bdev)
3758 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3759 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3760 		/* j_inum for internal journal is non-zero */
3761 		j_inode = ext4_get_journal_inode(sb, j_inum);
3762 		if (j_inode) {
3763 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3764 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3765 			iput(j_inode);
3766 		} else {
3767 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3768 		}
3769 	}
3770 	sbi->s_overhead = overhead;
3771 	smp_wmb();
3772 	free_page((unsigned long) buf);
3773 	return 0;
3774 }
3775 
3776 static void ext4_set_resv_clusters(struct super_block *sb)
3777 {
3778 	ext4_fsblk_t resv_clusters;
3779 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3780 
3781 	/*
3782 	 * There's no need to reserve anything when we aren't using extents.
3783 	 * The space estimates are exact, there are no unwritten extents,
3784 	 * hole punching doesn't need new metadata... This is needed especially
3785 	 * to keep ext2/3 backward compatibility.
3786 	 */
3787 	if (!ext4_has_feature_extents(sb))
3788 		return;
3789 	/*
3790 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3791 	 * This should cover the situations where we can not afford to run
3792 	 * out of space like for example punch hole, or converting
3793 	 * unwritten extents in delalloc path. In most cases such
3794 	 * allocation would require 1, or 2 blocks, higher numbers are
3795 	 * very rare.
3796 	 */
3797 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3798 			 sbi->s_cluster_bits);
3799 
3800 	do_div(resv_clusters, 50);
3801 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3802 
3803 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3804 }
3805 
3806 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3807 {
3808 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3809 	char *orig_data = kstrdup(data, GFP_KERNEL);
3810 	struct buffer_head *bh, **group_desc;
3811 	struct ext4_super_block *es = NULL;
3812 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3813 	struct flex_groups **flex_groups;
3814 	ext4_fsblk_t block;
3815 	ext4_fsblk_t sb_block = get_sb_block(&data);
3816 	ext4_fsblk_t logical_sb_block;
3817 	unsigned long offset = 0;
3818 	unsigned long journal_devnum = 0;
3819 	unsigned long def_mount_opts;
3820 	struct inode *root;
3821 	const char *descr;
3822 	int ret = -ENOMEM;
3823 	int blocksize, clustersize;
3824 	unsigned int db_count;
3825 	unsigned int i;
3826 	int needs_recovery, has_huge_files;
3827 	__u64 blocks_count;
3828 	int err = 0;
3829 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3830 	ext4_group_t first_not_zeroed;
3831 
3832 	if ((data && !orig_data) || !sbi)
3833 		goto out_free_base;
3834 
3835 	sbi->s_daxdev = dax_dev;
3836 	sbi->s_blockgroup_lock =
3837 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3838 	if (!sbi->s_blockgroup_lock)
3839 		goto out_free_base;
3840 
3841 	sb->s_fs_info = sbi;
3842 	sbi->s_sb = sb;
3843 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3844 	sbi->s_sb_block = sb_block;
3845 	if (sb->s_bdev->bd_part)
3846 		sbi->s_sectors_written_start =
3847 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3848 
3849 	/* Cleanup superblock name */
3850 	strreplace(sb->s_id, '/', '!');
3851 
3852 	/* -EINVAL is default */
3853 	ret = -EINVAL;
3854 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3855 	if (!blocksize) {
3856 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3857 		goto out_fail;
3858 	}
3859 
3860 	/*
3861 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3862 	 * block sizes.  We need to calculate the offset from buffer start.
3863 	 */
3864 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3865 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3866 		offset = do_div(logical_sb_block, blocksize);
3867 	} else {
3868 		logical_sb_block = sb_block;
3869 	}
3870 
3871 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3872 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3873 		goto out_fail;
3874 	}
3875 	/*
3876 	 * Note: s_es must be initialized as soon as possible because
3877 	 *       some ext4 macro-instructions depend on its value
3878 	 */
3879 	es = (struct ext4_super_block *) (bh->b_data + offset);
3880 	sbi->s_es = es;
3881 	sb->s_magic = le16_to_cpu(es->s_magic);
3882 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3883 		goto cantfind_ext4;
3884 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3885 
3886 	/* Warn if metadata_csum and gdt_csum are both set. */
3887 	if (ext4_has_feature_metadata_csum(sb) &&
3888 	    ext4_has_feature_gdt_csum(sb))
3889 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3890 			     "redundant flags; please run fsck.");
3891 
3892 	/* Check for a known checksum algorithm */
3893 	if (!ext4_verify_csum_type(sb, es)) {
3894 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3895 			 "unknown checksum algorithm.");
3896 		silent = 1;
3897 		goto cantfind_ext4;
3898 	}
3899 
3900 	/* Load the checksum driver */
3901 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3902 	if (IS_ERR(sbi->s_chksum_driver)) {
3903 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3904 		ret = PTR_ERR(sbi->s_chksum_driver);
3905 		sbi->s_chksum_driver = NULL;
3906 		goto failed_mount;
3907 	}
3908 
3909 	/* Check superblock checksum */
3910 	if (!ext4_superblock_csum_verify(sb, es)) {
3911 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3912 			 "invalid superblock checksum.  Run e2fsck?");
3913 		silent = 1;
3914 		ret = -EFSBADCRC;
3915 		goto cantfind_ext4;
3916 	}
3917 
3918 	/* Precompute checksum seed for all metadata */
3919 	if (ext4_has_feature_csum_seed(sb))
3920 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3921 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3922 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3923 					       sizeof(es->s_uuid));
3924 
3925 	/* Set defaults before we parse the mount options */
3926 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3927 	set_opt(sb, INIT_INODE_TABLE);
3928 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3929 		set_opt(sb, DEBUG);
3930 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3931 		set_opt(sb, GRPID);
3932 	if (def_mount_opts & EXT4_DEFM_UID16)
3933 		set_opt(sb, NO_UID32);
3934 	/* xattr user namespace & acls are now defaulted on */
3935 	set_opt(sb, XATTR_USER);
3936 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3937 	set_opt(sb, POSIX_ACL);
3938 #endif
3939 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3940 	if (ext4_has_metadata_csum(sb))
3941 		set_opt(sb, JOURNAL_CHECKSUM);
3942 
3943 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3944 		set_opt(sb, JOURNAL_DATA);
3945 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3946 		set_opt(sb, ORDERED_DATA);
3947 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3948 		set_opt(sb, WRITEBACK_DATA);
3949 
3950 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3951 		set_opt(sb, ERRORS_PANIC);
3952 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3953 		set_opt(sb, ERRORS_CONT);
3954 	else
3955 		set_opt(sb, ERRORS_RO);
3956 	/* block_validity enabled by default; disable with noblock_validity */
3957 	set_opt(sb, BLOCK_VALIDITY);
3958 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3959 		set_opt(sb, DISCARD);
3960 
3961 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3962 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3963 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3964 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3965 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3966 
3967 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3968 		set_opt(sb, BARRIER);
3969 
3970 	/*
3971 	 * enable delayed allocation by default
3972 	 * Use -o nodelalloc to turn it off
3973 	 */
3974 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3975 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3976 		set_opt(sb, DELALLOC);
3977 
3978 	/*
3979 	 * set default s_li_wait_mult for lazyinit, for the case there is
3980 	 * no mount option specified.
3981 	 */
3982 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3983 
3984 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3985 
3986 	if (blocksize == PAGE_SIZE)
3987 		set_opt(sb, DIOREAD_NOLOCK);
3988 
3989 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3990 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3991 		ext4_msg(sb, KERN_ERR,
3992 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3993 			 blocksize, le32_to_cpu(es->s_log_block_size));
3994 		goto failed_mount;
3995 	}
3996 
3997 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3998 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3999 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4000 	} else {
4001 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4002 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4003 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4004 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4005 				 sbi->s_first_ino);
4006 			goto failed_mount;
4007 		}
4008 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4009 		    (!is_power_of_2(sbi->s_inode_size)) ||
4010 		    (sbi->s_inode_size > blocksize)) {
4011 			ext4_msg(sb, KERN_ERR,
4012 			       "unsupported inode size: %d",
4013 			       sbi->s_inode_size);
4014 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4015 			goto failed_mount;
4016 		}
4017 		/*
4018 		 * i_atime_extra is the last extra field available for
4019 		 * [acm]times in struct ext4_inode. Checking for that
4020 		 * field should suffice to ensure we have extra space
4021 		 * for all three.
4022 		 */
4023 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4024 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4025 			sb->s_time_gran = 1;
4026 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4027 		} else {
4028 			sb->s_time_gran = NSEC_PER_SEC;
4029 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4030 		}
4031 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4032 	}
4033 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4034 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4035 			EXT4_GOOD_OLD_INODE_SIZE;
4036 		if (ext4_has_feature_extra_isize(sb)) {
4037 			unsigned v, max = (sbi->s_inode_size -
4038 					   EXT4_GOOD_OLD_INODE_SIZE);
4039 
4040 			v = le16_to_cpu(es->s_want_extra_isize);
4041 			if (v > max) {
4042 				ext4_msg(sb, KERN_ERR,
4043 					 "bad s_want_extra_isize: %d", v);
4044 				goto failed_mount;
4045 			}
4046 			if (sbi->s_want_extra_isize < v)
4047 				sbi->s_want_extra_isize = v;
4048 
4049 			v = le16_to_cpu(es->s_min_extra_isize);
4050 			if (v > max) {
4051 				ext4_msg(sb, KERN_ERR,
4052 					 "bad s_min_extra_isize: %d", v);
4053 				goto failed_mount;
4054 			}
4055 			if (sbi->s_want_extra_isize < v)
4056 				sbi->s_want_extra_isize = v;
4057 		}
4058 	}
4059 
4060 	if (sbi->s_es->s_mount_opts[0]) {
4061 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
4062 					      sizeof(sbi->s_es->s_mount_opts),
4063 					      GFP_KERNEL);
4064 		if (!s_mount_opts)
4065 			goto failed_mount;
4066 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
4067 				   &journal_ioprio, 0)) {
4068 			ext4_msg(sb, KERN_WARNING,
4069 				 "failed to parse options in superblock: %s",
4070 				 s_mount_opts);
4071 		}
4072 		kfree(s_mount_opts);
4073 	}
4074 	sbi->s_def_mount_opt = sbi->s_mount_opt;
4075 	if (!parse_options((char *) data, sb, &journal_devnum,
4076 			   &journal_ioprio, 0))
4077 		goto failed_mount;
4078 
4079 #ifdef CONFIG_UNICODE
4080 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
4081 		const struct ext4_sb_encodings *encoding_info;
4082 		struct unicode_map *encoding;
4083 		__u16 encoding_flags;
4084 
4085 		if (ext4_has_feature_encrypt(sb)) {
4086 			ext4_msg(sb, KERN_ERR,
4087 				 "Can't mount with encoding and encryption");
4088 			goto failed_mount;
4089 		}
4090 
4091 		if (ext4_sb_read_encoding(es, &encoding_info,
4092 					  &encoding_flags)) {
4093 			ext4_msg(sb, KERN_ERR,
4094 				 "Encoding requested by superblock is unknown");
4095 			goto failed_mount;
4096 		}
4097 
4098 		encoding = utf8_load(encoding_info->version);
4099 		if (IS_ERR(encoding)) {
4100 			ext4_msg(sb, KERN_ERR,
4101 				 "can't mount with superblock charset: %s-%s "
4102 				 "not supported by the kernel. flags: 0x%x.",
4103 				 encoding_info->name, encoding_info->version,
4104 				 encoding_flags);
4105 			goto failed_mount;
4106 		}
4107 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4108 			 "%s-%s with flags 0x%hx", encoding_info->name,
4109 			 encoding_info->version?:"\b", encoding_flags);
4110 
4111 		sbi->s_encoding = encoding;
4112 		sbi->s_encoding_flags = encoding_flags;
4113 	}
4114 #endif
4115 
4116 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4117 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!\n");
4118 		/* can't mount with both data=journal and dioread_nolock. */
4119 		clear_opt(sb, DIOREAD_NOLOCK);
4120 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4121 			ext4_msg(sb, KERN_ERR, "can't mount with "
4122 				 "both data=journal and delalloc");
4123 			goto failed_mount;
4124 		}
4125 		if (test_opt(sb, DAX_ALWAYS)) {
4126 			ext4_msg(sb, KERN_ERR, "can't mount with "
4127 				 "both data=journal and dax");
4128 			goto failed_mount;
4129 		}
4130 		if (ext4_has_feature_encrypt(sb)) {
4131 			ext4_msg(sb, KERN_WARNING,
4132 				 "encrypted files will use data=ordered "
4133 				 "instead of data journaling mode");
4134 		}
4135 		if (test_opt(sb, DELALLOC))
4136 			clear_opt(sb, DELALLOC);
4137 	} else {
4138 		sb->s_iflags |= SB_I_CGROUPWB;
4139 	}
4140 
4141 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4142 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4143 
4144 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4145 	    (ext4_has_compat_features(sb) ||
4146 	     ext4_has_ro_compat_features(sb) ||
4147 	     ext4_has_incompat_features(sb)))
4148 		ext4_msg(sb, KERN_WARNING,
4149 		       "feature flags set on rev 0 fs, "
4150 		       "running e2fsck is recommended");
4151 
4152 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4153 		set_opt2(sb, HURD_COMPAT);
4154 		if (ext4_has_feature_64bit(sb)) {
4155 			ext4_msg(sb, KERN_ERR,
4156 				 "The Hurd can't support 64-bit file systems");
4157 			goto failed_mount;
4158 		}
4159 
4160 		/*
4161 		 * ea_inode feature uses l_i_version field which is not
4162 		 * available in HURD_COMPAT mode.
4163 		 */
4164 		if (ext4_has_feature_ea_inode(sb)) {
4165 			ext4_msg(sb, KERN_ERR,
4166 				 "ea_inode feature is not supported for Hurd");
4167 			goto failed_mount;
4168 		}
4169 	}
4170 
4171 	if (IS_EXT2_SB(sb)) {
4172 		if (ext2_feature_set_ok(sb))
4173 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4174 				 "using the ext4 subsystem");
4175 		else {
4176 			/*
4177 			 * If we're probing be silent, if this looks like
4178 			 * it's actually an ext[34] filesystem.
4179 			 */
4180 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4181 				goto failed_mount;
4182 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4183 				 "to feature incompatibilities");
4184 			goto failed_mount;
4185 		}
4186 	}
4187 
4188 	if (IS_EXT3_SB(sb)) {
4189 		if (ext3_feature_set_ok(sb))
4190 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4191 				 "using the ext4 subsystem");
4192 		else {
4193 			/*
4194 			 * If we're probing be silent, if this looks like
4195 			 * it's actually an ext4 filesystem.
4196 			 */
4197 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4198 				goto failed_mount;
4199 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4200 				 "to feature incompatibilities");
4201 			goto failed_mount;
4202 		}
4203 	}
4204 
4205 	/*
4206 	 * Check feature flags regardless of the revision level, since we
4207 	 * previously didn't change the revision level when setting the flags,
4208 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4209 	 */
4210 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4211 		goto failed_mount;
4212 
4213 	if (le32_to_cpu(es->s_log_block_size) >
4214 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4215 		ext4_msg(sb, KERN_ERR,
4216 			 "Invalid log block size: %u",
4217 			 le32_to_cpu(es->s_log_block_size));
4218 		goto failed_mount;
4219 	}
4220 	if (le32_to_cpu(es->s_log_cluster_size) >
4221 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4222 		ext4_msg(sb, KERN_ERR,
4223 			 "Invalid log cluster size: %u",
4224 			 le32_to_cpu(es->s_log_cluster_size));
4225 		goto failed_mount;
4226 	}
4227 
4228 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4229 		ext4_msg(sb, KERN_ERR,
4230 			 "Number of reserved GDT blocks insanely large: %d",
4231 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4232 		goto failed_mount;
4233 	}
4234 
4235 	if (bdev_dax_supported(sb->s_bdev, blocksize))
4236 		set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4237 
4238 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4239 		if (ext4_has_feature_inline_data(sb)) {
4240 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4241 					" that may contain inline data");
4242 			goto failed_mount;
4243 		}
4244 		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4245 			ext4_msg(sb, KERN_ERR,
4246 				"DAX unsupported by block device.");
4247 			goto failed_mount;
4248 		}
4249 	}
4250 
4251 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4252 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4253 			 es->s_encryption_level);
4254 		goto failed_mount;
4255 	}
4256 
4257 	if (sb->s_blocksize != blocksize) {
4258 		/* Validate the filesystem blocksize */
4259 		if (!sb_set_blocksize(sb, blocksize)) {
4260 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4261 					blocksize);
4262 			goto failed_mount;
4263 		}
4264 
4265 		brelse(bh);
4266 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4267 		offset = do_div(logical_sb_block, blocksize);
4268 		bh = sb_bread_unmovable(sb, logical_sb_block);
4269 		if (!bh) {
4270 			ext4_msg(sb, KERN_ERR,
4271 			       "Can't read superblock on 2nd try");
4272 			goto failed_mount;
4273 		}
4274 		es = (struct ext4_super_block *)(bh->b_data + offset);
4275 		sbi->s_es = es;
4276 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4277 			ext4_msg(sb, KERN_ERR,
4278 			       "Magic mismatch, very weird!");
4279 			goto failed_mount;
4280 		}
4281 	}
4282 
4283 	has_huge_files = ext4_has_feature_huge_file(sb);
4284 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4285 						      has_huge_files);
4286 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4287 
4288 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4289 	if (ext4_has_feature_64bit(sb)) {
4290 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4291 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4292 		    !is_power_of_2(sbi->s_desc_size)) {
4293 			ext4_msg(sb, KERN_ERR,
4294 			       "unsupported descriptor size %lu",
4295 			       sbi->s_desc_size);
4296 			goto failed_mount;
4297 		}
4298 	} else
4299 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4300 
4301 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4302 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4303 
4304 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4305 	if (sbi->s_inodes_per_block == 0)
4306 		goto cantfind_ext4;
4307 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4308 	    sbi->s_inodes_per_group > blocksize * 8) {
4309 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4310 			 sbi->s_inodes_per_group);
4311 		goto failed_mount;
4312 	}
4313 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4314 					sbi->s_inodes_per_block;
4315 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4316 	sbi->s_sbh = bh;
4317 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4318 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4319 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4320 
4321 	for (i = 0; i < 4; i++)
4322 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4323 	sbi->s_def_hash_version = es->s_def_hash_version;
4324 	if (ext4_has_feature_dir_index(sb)) {
4325 		i = le32_to_cpu(es->s_flags);
4326 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4327 			sbi->s_hash_unsigned = 3;
4328 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4329 #ifdef __CHAR_UNSIGNED__
4330 			if (!sb_rdonly(sb))
4331 				es->s_flags |=
4332 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4333 			sbi->s_hash_unsigned = 3;
4334 #else
4335 			if (!sb_rdonly(sb))
4336 				es->s_flags |=
4337 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4338 #endif
4339 		}
4340 	}
4341 
4342 	/* Handle clustersize */
4343 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4344 	if (ext4_has_feature_bigalloc(sb)) {
4345 		if (clustersize < blocksize) {
4346 			ext4_msg(sb, KERN_ERR,
4347 				 "cluster size (%d) smaller than "
4348 				 "block size (%d)", clustersize, blocksize);
4349 			goto failed_mount;
4350 		}
4351 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4352 			le32_to_cpu(es->s_log_block_size);
4353 		sbi->s_clusters_per_group =
4354 			le32_to_cpu(es->s_clusters_per_group);
4355 		if (sbi->s_clusters_per_group > blocksize * 8) {
4356 			ext4_msg(sb, KERN_ERR,
4357 				 "#clusters per group too big: %lu",
4358 				 sbi->s_clusters_per_group);
4359 			goto failed_mount;
4360 		}
4361 		if (sbi->s_blocks_per_group !=
4362 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4363 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4364 				 "clusters per group (%lu) inconsistent",
4365 				 sbi->s_blocks_per_group,
4366 				 sbi->s_clusters_per_group);
4367 			goto failed_mount;
4368 		}
4369 	} else {
4370 		if (clustersize != blocksize) {
4371 			ext4_msg(sb, KERN_ERR,
4372 				 "fragment/cluster size (%d) != "
4373 				 "block size (%d)", clustersize, blocksize);
4374 			goto failed_mount;
4375 		}
4376 		if (sbi->s_blocks_per_group > blocksize * 8) {
4377 			ext4_msg(sb, KERN_ERR,
4378 				 "#blocks per group too big: %lu",
4379 				 sbi->s_blocks_per_group);
4380 			goto failed_mount;
4381 		}
4382 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4383 		sbi->s_cluster_bits = 0;
4384 	}
4385 	sbi->s_cluster_ratio = clustersize / blocksize;
4386 
4387 	/* Do we have standard group size of clustersize * 8 blocks ? */
4388 	if (sbi->s_blocks_per_group == clustersize << 3)
4389 		set_opt2(sb, STD_GROUP_SIZE);
4390 
4391 	/*
4392 	 * Test whether we have more sectors than will fit in sector_t,
4393 	 * and whether the max offset is addressable by the page cache.
4394 	 */
4395 	err = generic_check_addressable(sb->s_blocksize_bits,
4396 					ext4_blocks_count(es));
4397 	if (err) {
4398 		ext4_msg(sb, KERN_ERR, "filesystem"
4399 			 " too large to mount safely on this system");
4400 		goto failed_mount;
4401 	}
4402 
4403 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4404 		goto cantfind_ext4;
4405 
4406 	/* check blocks count against device size */
4407 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4408 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4409 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4410 		       "exceeds size of device (%llu blocks)",
4411 		       ext4_blocks_count(es), blocks_count);
4412 		goto failed_mount;
4413 	}
4414 
4415 	/*
4416 	 * It makes no sense for the first data block to be beyond the end
4417 	 * of the filesystem.
4418 	 */
4419 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4420 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4421 			 "block %u is beyond end of filesystem (%llu)",
4422 			 le32_to_cpu(es->s_first_data_block),
4423 			 ext4_blocks_count(es));
4424 		goto failed_mount;
4425 	}
4426 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4427 	    (sbi->s_cluster_ratio == 1)) {
4428 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4429 			 "block is 0 with a 1k block and cluster size");
4430 		goto failed_mount;
4431 	}
4432 
4433 	blocks_count = (ext4_blocks_count(es) -
4434 			le32_to_cpu(es->s_first_data_block) +
4435 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4436 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4437 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4438 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4439 		       "(block count %llu, first data block %u, "
4440 		       "blocks per group %lu)", blocks_count,
4441 		       ext4_blocks_count(es),
4442 		       le32_to_cpu(es->s_first_data_block),
4443 		       EXT4_BLOCKS_PER_GROUP(sb));
4444 		goto failed_mount;
4445 	}
4446 	sbi->s_groups_count = blocks_count;
4447 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4448 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4449 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4450 	    le32_to_cpu(es->s_inodes_count)) {
4451 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4452 			 le32_to_cpu(es->s_inodes_count),
4453 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4454 		ret = -EINVAL;
4455 		goto failed_mount;
4456 	}
4457 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4458 		   EXT4_DESC_PER_BLOCK(sb);
4459 	if (ext4_has_feature_meta_bg(sb)) {
4460 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4461 			ext4_msg(sb, KERN_WARNING,
4462 				 "first meta block group too large: %u "
4463 				 "(group descriptor block count %u)",
4464 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4465 			goto failed_mount;
4466 		}
4467 	}
4468 	rcu_assign_pointer(sbi->s_group_desc,
4469 			   kvmalloc_array(db_count,
4470 					  sizeof(struct buffer_head *),
4471 					  GFP_KERNEL));
4472 	if (sbi->s_group_desc == NULL) {
4473 		ext4_msg(sb, KERN_ERR, "not enough memory");
4474 		ret = -ENOMEM;
4475 		goto failed_mount;
4476 	}
4477 
4478 	bgl_lock_init(sbi->s_blockgroup_lock);
4479 
4480 	/* Pre-read the descriptors into the buffer cache */
4481 	for (i = 0; i < db_count; i++) {
4482 		block = descriptor_loc(sb, logical_sb_block, i);
4483 		sb_breadahead_unmovable(sb, block);
4484 	}
4485 
4486 	for (i = 0; i < db_count; i++) {
4487 		struct buffer_head *bh;
4488 
4489 		block = descriptor_loc(sb, logical_sb_block, i);
4490 		bh = sb_bread_unmovable(sb, block);
4491 		if (!bh) {
4492 			ext4_msg(sb, KERN_ERR,
4493 			       "can't read group descriptor %d", i);
4494 			db_count = i;
4495 			goto failed_mount2;
4496 		}
4497 		rcu_read_lock();
4498 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4499 		rcu_read_unlock();
4500 	}
4501 	sbi->s_gdb_count = db_count;
4502 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4503 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4504 		ret = -EFSCORRUPTED;
4505 		goto failed_mount2;
4506 	}
4507 
4508 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4509 
4510 	/* Register extent status tree shrinker */
4511 	if (ext4_es_register_shrinker(sbi))
4512 		goto failed_mount3;
4513 
4514 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4515 	sbi->s_extent_max_zeroout_kb = 32;
4516 
4517 	/*
4518 	 * set up enough so that it can read an inode
4519 	 */
4520 	sb->s_op = &ext4_sops;
4521 	sb->s_export_op = &ext4_export_ops;
4522 	sb->s_xattr = ext4_xattr_handlers;
4523 #ifdef CONFIG_FS_ENCRYPTION
4524 	sb->s_cop = &ext4_cryptops;
4525 #endif
4526 #ifdef CONFIG_FS_VERITY
4527 	sb->s_vop = &ext4_verityops;
4528 #endif
4529 #ifdef CONFIG_QUOTA
4530 	sb->dq_op = &ext4_quota_operations;
4531 	if (ext4_has_feature_quota(sb))
4532 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4533 	else
4534 		sb->s_qcop = &ext4_qctl_operations;
4535 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4536 #endif
4537 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4538 
4539 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4540 	mutex_init(&sbi->s_orphan_lock);
4541 
4542 	sb->s_root = NULL;
4543 
4544 	needs_recovery = (es->s_last_orphan != 0 ||
4545 			  ext4_has_feature_journal_needs_recovery(sb));
4546 
4547 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4548 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4549 			goto failed_mount3a;
4550 
4551 	/*
4552 	 * The first inode we look at is the journal inode.  Don't try
4553 	 * root first: it may be modified in the journal!
4554 	 */
4555 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4556 		err = ext4_load_journal(sb, es, journal_devnum);
4557 		if (err)
4558 			goto failed_mount3a;
4559 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4560 		   ext4_has_feature_journal_needs_recovery(sb)) {
4561 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4562 		       "suppressed and not mounted read-only");
4563 		goto failed_mount_wq;
4564 	} else {
4565 		/* Nojournal mode, all journal mount options are illegal */
4566 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4567 			ext4_msg(sb, KERN_ERR, "can't mount with "
4568 				 "journal_checksum, fs mounted w/o journal");
4569 			goto failed_mount_wq;
4570 		}
4571 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4572 			ext4_msg(sb, KERN_ERR, "can't mount with "
4573 				 "journal_async_commit, fs mounted w/o journal");
4574 			goto failed_mount_wq;
4575 		}
4576 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4577 			ext4_msg(sb, KERN_ERR, "can't mount with "
4578 				 "commit=%lu, fs mounted w/o journal",
4579 				 sbi->s_commit_interval / HZ);
4580 			goto failed_mount_wq;
4581 		}
4582 		if (EXT4_MOUNT_DATA_FLAGS &
4583 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4584 			ext4_msg(sb, KERN_ERR, "can't mount with "
4585 				 "data=, fs mounted w/o journal");
4586 			goto failed_mount_wq;
4587 		}
4588 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4589 		clear_opt(sb, JOURNAL_CHECKSUM);
4590 		clear_opt(sb, DATA_FLAGS);
4591 		sbi->s_journal = NULL;
4592 		needs_recovery = 0;
4593 		goto no_journal;
4594 	}
4595 
4596 	if (ext4_has_feature_64bit(sb) &&
4597 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4598 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4599 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4600 		goto failed_mount_wq;
4601 	}
4602 
4603 	if (!set_journal_csum_feature_set(sb)) {
4604 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4605 			 "feature set");
4606 		goto failed_mount_wq;
4607 	}
4608 
4609 	/* We have now updated the journal if required, so we can
4610 	 * validate the data journaling mode. */
4611 	switch (test_opt(sb, DATA_FLAGS)) {
4612 	case 0:
4613 		/* No mode set, assume a default based on the journal
4614 		 * capabilities: ORDERED_DATA if the journal can
4615 		 * cope, else JOURNAL_DATA
4616 		 */
4617 		if (jbd2_journal_check_available_features
4618 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4619 			set_opt(sb, ORDERED_DATA);
4620 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4621 		} else {
4622 			set_opt(sb, JOURNAL_DATA);
4623 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4624 		}
4625 		break;
4626 
4627 	case EXT4_MOUNT_ORDERED_DATA:
4628 	case EXT4_MOUNT_WRITEBACK_DATA:
4629 		if (!jbd2_journal_check_available_features
4630 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4631 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4632 			       "requested data journaling mode");
4633 			goto failed_mount_wq;
4634 		}
4635 	default:
4636 		break;
4637 	}
4638 
4639 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4640 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4641 		ext4_msg(sb, KERN_ERR, "can't mount with "
4642 			"journal_async_commit in data=ordered mode");
4643 		goto failed_mount_wq;
4644 	}
4645 
4646 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4647 
4648 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4649 
4650 no_journal:
4651 	if (!test_opt(sb, NO_MBCACHE)) {
4652 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4653 		if (!sbi->s_ea_block_cache) {
4654 			ext4_msg(sb, KERN_ERR,
4655 				 "Failed to create ea_block_cache");
4656 			goto failed_mount_wq;
4657 		}
4658 
4659 		if (ext4_has_feature_ea_inode(sb)) {
4660 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4661 			if (!sbi->s_ea_inode_cache) {
4662 				ext4_msg(sb, KERN_ERR,
4663 					 "Failed to create ea_inode_cache");
4664 				goto failed_mount_wq;
4665 			}
4666 		}
4667 	}
4668 
4669 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4670 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4671 		goto failed_mount_wq;
4672 	}
4673 
4674 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4675 	    !ext4_has_feature_encrypt(sb)) {
4676 		ext4_set_feature_encrypt(sb);
4677 		ext4_commit_super(sb, 1);
4678 	}
4679 
4680 	/*
4681 	 * Get the # of file system overhead blocks from the
4682 	 * superblock if present.
4683 	 */
4684 	if (es->s_overhead_clusters)
4685 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4686 	else {
4687 		err = ext4_calculate_overhead(sb);
4688 		if (err)
4689 			goto failed_mount_wq;
4690 	}
4691 
4692 	/*
4693 	 * The maximum number of concurrent works can be high and
4694 	 * concurrency isn't really necessary.  Limit it to 1.
4695 	 */
4696 	EXT4_SB(sb)->rsv_conversion_wq =
4697 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4698 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4699 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4700 		ret = -ENOMEM;
4701 		goto failed_mount4;
4702 	}
4703 
4704 	/*
4705 	 * The jbd2_journal_load will have done any necessary log recovery,
4706 	 * so we can safely mount the rest of the filesystem now.
4707 	 */
4708 
4709 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4710 	if (IS_ERR(root)) {
4711 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4712 		ret = PTR_ERR(root);
4713 		root = NULL;
4714 		goto failed_mount4;
4715 	}
4716 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4717 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4718 		iput(root);
4719 		goto failed_mount4;
4720 	}
4721 
4722 #ifdef CONFIG_UNICODE
4723 	if (sbi->s_encoding)
4724 		sb->s_d_op = &ext4_dentry_ops;
4725 #endif
4726 
4727 	sb->s_root = d_make_root(root);
4728 	if (!sb->s_root) {
4729 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4730 		ret = -ENOMEM;
4731 		goto failed_mount4;
4732 	}
4733 
4734 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4735 	if (ret == -EROFS) {
4736 		sb->s_flags |= SB_RDONLY;
4737 		ret = 0;
4738 	} else if (ret)
4739 		goto failed_mount4a;
4740 
4741 	ext4_set_resv_clusters(sb);
4742 
4743 	if (test_opt(sb, BLOCK_VALIDITY)) {
4744 		err = ext4_setup_system_zone(sb);
4745 		if (err) {
4746 			ext4_msg(sb, KERN_ERR, "failed to initialize system "
4747 				 "zone (%d)", err);
4748 			goto failed_mount4a;
4749 		}
4750 	}
4751 
4752 	ext4_ext_init(sb);
4753 	err = ext4_mb_init(sb);
4754 	if (err) {
4755 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4756 			 err);
4757 		goto failed_mount5;
4758 	}
4759 
4760 	block = ext4_count_free_clusters(sb);
4761 	ext4_free_blocks_count_set(sbi->s_es,
4762 				   EXT4_C2B(sbi, block));
4763 	ext4_superblock_csum_set(sb);
4764 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4765 				  GFP_KERNEL);
4766 	if (!err) {
4767 		unsigned long freei = ext4_count_free_inodes(sb);
4768 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4769 		ext4_superblock_csum_set(sb);
4770 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4771 					  GFP_KERNEL);
4772 	}
4773 	if (!err)
4774 		err = percpu_counter_init(&sbi->s_dirs_counter,
4775 					  ext4_count_dirs(sb), GFP_KERNEL);
4776 	if (!err)
4777 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4778 					  GFP_KERNEL);
4779 	if (!err)
4780 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
4781 
4782 	if (err) {
4783 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4784 		goto failed_mount6;
4785 	}
4786 
4787 	if (ext4_has_feature_flex_bg(sb))
4788 		if (!ext4_fill_flex_info(sb)) {
4789 			ext4_msg(sb, KERN_ERR,
4790 			       "unable to initialize "
4791 			       "flex_bg meta info!");
4792 			goto failed_mount6;
4793 		}
4794 
4795 	err = ext4_register_li_request(sb, first_not_zeroed);
4796 	if (err)
4797 		goto failed_mount6;
4798 
4799 	err = ext4_register_sysfs(sb);
4800 	if (err)
4801 		goto failed_mount7;
4802 
4803 #ifdef CONFIG_QUOTA
4804 	/* Enable quota usage during mount. */
4805 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4806 		err = ext4_enable_quotas(sb);
4807 		if (err)
4808 			goto failed_mount8;
4809 	}
4810 #endif  /* CONFIG_QUOTA */
4811 
4812 	/*
4813 	 * Save the original bdev mapping's wb_err value which could be
4814 	 * used to detect the metadata async write error.
4815 	 */
4816 	spin_lock_init(&sbi->s_bdev_wb_lock);
4817 	if (!sb_rdonly(sb))
4818 		errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
4819 					 &sbi->s_bdev_wb_err);
4820 	sb->s_bdev->bd_super = sb;
4821 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4822 	ext4_orphan_cleanup(sb, es);
4823 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4824 	if (needs_recovery) {
4825 		ext4_msg(sb, KERN_INFO, "recovery complete");
4826 		err = ext4_mark_recovery_complete(sb, es);
4827 		if (err)
4828 			goto failed_mount8;
4829 	}
4830 	if (EXT4_SB(sb)->s_journal) {
4831 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4832 			descr = " journalled data mode";
4833 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4834 			descr = " ordered data mode";
4835 		else
4836 			descr = " writeback data mode";
4837 	} else
4838 		descr = "out journal";
4839 
4840 	if (test_opt(sb, DISCARD)) {
4841 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4842 		if (!blk_queue_discard(q))
4843 			ext4_msg(sb, KERN_WARNING,
4844 				 "mounting with \"discard\" option, but "
4845 				 "the device does not support discard");
4846 	}
4847 
4848 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4849 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4850 			 "Opts: %.*s%s%s", descr,
4851 			 (int) sizeof(sbi->s_es->s_mount_opts),
4852 			 sbi->s_es->s_mount_opts,
4853 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4854 
4855 	if (es->s_error_count)
4856 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4857 
4858 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4859 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4860 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4861 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4862 	atomic_set(&sbi->s_warning_count, 0);
4863 	atomic_set(&sbi->s_msg_count, 0);
4864 
4865 	kfree(orig_data);
4866 	return 0;
4867 
4868 cantfind_ext4:
4869 	if (!silent)
4870 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4871 	goto failed_mount;
4872 
4873 failed_mount8:
4874 	ext4_unregister_sysfs(sb);
4875 failed_mount7:
4876 	ext4_unregister_li_request(sb);
4877 failed_mount6:
4878 	ext4_mb_release(sb);
4879 	rcu_read_lock();
4880 	flex_groups = rcu_dereference(sbi->s_flex_groups);
4881 	if (flex_groups) {
4882 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
4883 			kvfree(flex_groups[i]);
4884 		kvfree(flex_groups);
4885 	}
4886 	rcu_read_unlock();
4887 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4888 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4889 	percpu_counter_destroy(&sbi->s_dirs_counter);
4890 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4891 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
4892 failed_mount5:
4893 	ext4_ext_release(sb);
4894 	ext4_release_system_zone(sb);
4895 failed_mount4a:
4896 	dput(sb->s_root);
4897 	sb->s_root = NULL;
4898 failed_mount4:
4899 	ext4_msg(sb, KERN_ERR, "mount failed");
4900 	if (EXT4_SB(sb)->rsv_conversion_wq)
4901 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4902 failed_mount_wq:
4903 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4904 	sbi->s_ea_inode_cache = NULL;
4905 
4906 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4907 	sbi->s_ea_block_cache = NULL;
4908 
4909 	if (sbi->s_journal) {
4910 		jbd2_journal_destroy(sbi->s_journal);
4911 		sbi->s_journal = NULL;
4912 	}
4913 failed_mount3a:
4914 	ext4_es_unregister_shrinker(sbi);
4915 failed_mount3:
4916 	del_timer_sync(&sbi->s_err_report);
4917 	if (sbi->s_mmp_tsk)
4918 		kthread_stop(sbi->s_mmp_tsk);
4919 failed_mount2:
4920 	rcu_read_lock();
4921 	group_desc = rcu_dereference(sbi->s_group_desc);
4922 	for (i = 0; i < db_count; i++)
4923 		brelse(group_desc[i]);
4924 	kvfree(group_desc);
4925 	rcu_read_unlock();
4926 failed_mount:
4927 	if (sbi->s_chksum_driver)
4928 		crypto_free_shash(sbi->s_chksum_driver);
4929 
4930 #ifdef CONFIG_UNICODE
4931 	utf8_unload(sbi->s_encoding);
4932 #endif
4933 
4934 #ifdef CONFIG_QUOTA
4935 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4936 		kfree(get_qf_name(sb, sbi, i));
4937 #endif
4938 	fscrypt_free_dummy_context(&sbi->s_dummy_enc_ctx);
4939 	ext4_blkdev_remove(sbi);
4940 	brelse(bh);
4941 out_fail:
4942 	sb->s_fs_info = NULL;
4943 	kfree(sbi->s_blockgroup_lock);
4944 out_free_base:
4945 	kfree(sbi);
4946 	kfree(orig_data);
4947 	fs_put_dax(dax_dev);
4948 	return err ? err : ret;
4949 }
4950 
4951 /*
4952  * Setup any per-fs journal parameters now.  We'll do this both on
4953  * initial mount, once the journal has been initialised but before we've
4954  * done any recovery; and again on any subsequent remount.
4955  */
4956 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4957 {
4958 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4959 
4960 	journal->j_commit_interval = sbi->s_commit_interval;
4961 	journal->j_min_batch_time = sbi->s_min_batch_time;
4962 	journal->j_max_batch_time = sbi->s_max_batch_time;
4963 
4964 	write_lock(&journal->j_state_lock);
4965 	if (test_opt(sb, BARRIER))
4966 		journal->j_flags |= JBD2_BARRIER;
4967 	else
4968 		journal->j_flags &= ~JBD2_BARRIER;
4969 	if (test_opt(sb, DATA_ERR_ABORT))
4970 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4971 	else
4972 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4973 	write_unlock(&journal->j_state_lock);
4974 }
4975 
4976 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4977 					     unsigned int journal_inum)
4978 {
4979 	struct inode *journal_inode;
4980 
4981 	/*
4982 	 * Test for the existence of a valid inode on disk.  Bad things
4983 	 * happen if we iget() an unused inode, as the subsequent iput()
4984 	 * will try to delete it.
4985 	 */
4986 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4987 	if (IS_ERR(journal_inode)) {
4988 		ext4_msg(sb, KERN_ERR, "no journal found");
4989 		return NULL;
4990 	}
4991 	if (!journal_inode->i_nlink) {
4992 		make_bad_inode(journal_inode);
4993 		iput(journal_inode);
4994 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4995 		return NULL;
4996 	}
4997 
4998 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4999 		  journal_inode, journal_inode->i_size);
5000 	if (!S_ISREG(journal_inode->i_mode)) {
5001 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
5002 		iput(journal_inode);
5003 		return NULL;
5004 	}
5005 	return journal_inode;
5006 }
5007 
5008 static journal_t *ext4_get_journal(struct super_block *sb,
5009 				   unsigned int journal_inum)
5010 {
5011 	struct inode *journal_inode;
5012 	journal_t *journal;
5013 
5014 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5015 		return NULL;
5016 
5017 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
5018 	if (!journal_inode)
5019 		return NULL;
5020 
5021 	journal = jbd2_journal_init_inode(journal_inode);
5022 	if (!journal) {
5023 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5024 		iput(journal_inode);
5025 		return NULL;
5026 	}
5027 	journal->j_private = sb;
5028 	ext4_init_journal_params(sb, journal);
5029 	return journal;
5030 }
5031 
5032 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5033 				       dev_t j_dev)
5034 {
5035 	struct buffer_head *bh;
5036 	journal_t *journal;
5037 	ext4_fsblk_t start;
5038 	ext4_fsblk_t len;
5039 	int hblock, blocksize;
5040 	ext4_fsblk_t sb_block;
5041 	unsigned long offset;
5042 	struct ext4_super_block *es;
5043 	struct block_device *bdev;
5044 
5045 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5046 		return NULL;
5047 
5048 	bdev = ext4_blkdev_get(j_dev, sb);
5049 	if (bdev == NULL)
5050 		return NULL;
5051 
5052 	blocksize = sb->s_blocksize;
5053 	hblock = bdev_logical_block_size(bdev);
5054 	if (blocksize < hblock) {
5055 		ext4_msg(sb, KERN_ERR,
5056 			"blocksize too small for journal device");
5057 		goto out_bdev;
5058 	}
5059 
5060 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5061 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5062 	set_blocksize(bdev, blocksize);
5063 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
5064 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5065 		       "external journal");
5066 		goto out_bdev;
5067 	}
5068 
5069 	es = (struct ext4_super_block *) (bh->b_data + offset);
5070 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5071 	    !(le32_to_cpu(es->s_feature_incompat) &
5072 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5073 		ext4_msg(sb, KERN_ERR, "external journal has "
5074 					"bad superblock");
5075 		brelse(bh);
5076 		goto out_bdev;
5077 	}
5078 
5079 	if ((le32_to_cpu(es->s_feature_ro_compat) &
5080 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5081 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
5082 		ext4_msg(sb, KERN_ERR, "external journal has "
5083 				       "corrupt superblock");
5084 		brelse(bh);
5085 		goto out_bdev;
5086 	}
5087 
5088 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5089 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5090 		brelse(bh);
5091 		goto out_bdev;
5092 	}
5093 
5094 	len = ext4_blocks_count(es);
5095 	start = sb_block + 1;
5096 	brelse(bh);	/* we're done with the superblock */
5097 
5098 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5099 					start, len, blocksize);
5100 	if (!journal) {
5101 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
5102 		goto out_bdev;
5103 	}
5104 	journal->j_private = sb;
5105 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
5106 	wait_on_buffer(journal->j_sb_buffer);
5107 	if (!buffer_uptodate(journal->j_sb_buffer)) {
5108 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5109 		goto out_journal;
5110 	}
5111 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5112 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
5113 					"user (unsupported) - %d",
5114 			be32_to_cpu(journal->j_superblock->s_nr_users));
5115 		goto out_journal;
5116 	}
5117 	EXT4_SB(sb)->journal_bdev = bdev;
5118 	ext4_init_journal_params(sb, journal);
5119 	return journal;
5120 
5121 out_journal:
5122 	jbd2_journal_destroy(journal);
5123 out_bdev:
5124 	ext4_blkdev_put(bdev);
5125 	return NULL;
5126 }
5127 
5128 static int ext4_load_journal(struct super_block *sb,
5129 			     struct ext4_super_block *es,
5130 			     unsigned long journal_devnum)
5131 {
5132 	journal_t *journal;
5133 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5134 	dev_t journal_dev;
5135 	int err = 0;
5136 	int really_read_only;
5137 	int journal_dev_ro;
5138 
5139 	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5140 		return -EFSCORRUPTED;
5141 
5142 	if (journal_devnum &&
5143 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5144 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5145 			"numbers have changed");
5146 		journal_dev = new_decode_dev(journal_devnum);
5147 	} else
5148 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5149 
5150 	if (journal_inum && journal_dev) {
5151 		ext4_msg(sb, KERN_ERR,
5152 			 "filesystem has both journal inode and journal device!");
5153 		return -EINVAL;
5154 	}
5155 
5156 	if (journal_inum) {
5157 		journal = ext4_get_journal(sb, journal_inum);
5158 		if (!journal)
5159 			return -EINVAL;
5160 	} else {
5161 		journal = ext4_get_dev_journal(sb, journal_dev);
5162 		if (!journal)
5163 			return -EINVAL;
5164 	}
5165 
5166 	journal_dev_ro = bdev_read_only(journal->j_dev);
5167 	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5168 
5169 	if (journal_dev_ro && !sb_rdonly(sb)) {
5170 		ext4_msg(sb, KERN_ERR,
5171 			 "journal device read-only, try mounting with '-o ro'");
5172 		err = -EROFS;
5173 		goto err_out;
5174 	}
5175 
5176 	/*
5177 	 * Are we loading a blank journal or performing recovery after a
5178 	 * crash?  For recovery, we need to check in advance whether we
5179 	 * can get read-write access to the device.
5180 	 */
5181 	if (ext4_has_feature_journal_needs_recovery(sb)) {
5182 		if (sb_rdonly(sb)) {
5183 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5184 					"required on readonly filesystem");
5185 			if (really_read_only) {
5186 				ext4_msg(sb, KERN_ERR, "write access "
5187 					"unavailable, cannot proceed "
5188 					"(try mounting with noload)");
5189 				err = -EROFS;
5190 				goto err_out;
5191 			}
5192 			ext4_msg(sb, KERN_INFO, "write access will "
5193 			       "be enabled during recovery");
5194 		}
5195 	}
5196 
5197 	if (!(journal->j_flags & JBD2_BARRIER))
5198 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5199 
5200 	if (!ext4_has_feature_journal_needs_recovery(sb))
5201 		err = jbd2_journal_wipe(journal, !really_read_only);
5202 	if (!err) {
5203 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5204 		if (save)
5205 			memcpy(save, ((char *) es) +
5206 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5207 		err = jbd2_journal_load(journal);
5208 		if (save)
5209 			memcpy(((char *) es) + EXT4_S_ERR_START,
5210 			       save, EXT4_S_ERR_LEN);
5211 		kfree(save);
5212 	}
5213 
5214 	if (err) {
5215 		ext4_msg(sb, KERN_ERR, "error loading journal");
5216 		goto err_out;
5217 	}
5218 
5219 	EXT4_SB(sb)->s_journal = journal;
5220 	err = ext4_clear_journal_err(sb, es);
5221 	if (err) {
5222 		EXT4_SB(sb)->s_journal = NULL;
5223 		jbd2_journal_destroy(journal);
5224 		return err;
5225 	}
5226 
5227 	if (!really_read_only && journal_devnum &&
5228 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5229 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5230 
5231 		/* Make sure we flush the recovery flag to disk. */
5232 		ext4_commit_super(sb, 1);
5233 	}
5234 
5235 	return 0;
5236 
5237 err_out:
5238 	jbd2_journal_destroy(journal);
5239 	return err;
5240 }
5241 
5242 static int ext4_commit_super(struct super_block *sb, int sync)
5243 {
5244 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5245 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5246 	int error = 0;
5247 
5248 	if (!sbh || block_device_ejected(sb))
5249 		return error;
5250 
5251 	/*
5252 	 * If the file system is mounted read-only, don't update the
5253 	 * superblock write time.  This avoids updating the superblock
5254 	 * write time when we are mounting the root file system
5255 	 * read/only but we need to replay the journal; at that point,
5256 	 * for people who are east of GMT and who make their clock
5257 	 * tick in localtime for Windows bug-for-bug compatibility,
5258 	 * the clock is set in the future, and this will cause e2fsck
5259 	 * to complain and force a full file system check.
5260 	 */
5261 	if (!(sb->s_flags & SB_RDONLY))
5262 		ext4_update_tstamp(es, s_wtime);
5263 	if (sb->s_bdev->bd_part)
5264 		es->s_kbytes_written =
5265 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5266 			    ((part_stat_read(sb->s_bdev->bd_part,
5267 					     sectors[STAT_WRITE]) -
5268 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5269 	else
5270 		es->s_kbytes_written =
5271 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5272 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5273 		ext4_free_blocks_count_set(es,
5274 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5275 				&EXT4_SB(sb)->s_freeclusters_counter)));
5276 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5277 		es->s_free_inodes_count =
5278 			cpu_to_le32(percpu_counter_sum_positive(
5279 				&EXT4_SB(sb)->s_freeinodes_counter));
5280 	BUFFER_TRACE(sbh, "marking dirty");
5281 	ext4_superblock_csum_set(sb);
5282 	if (sync)
5283 		lock_buffer(sbh);
5284 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5285 		/*
5286 		 * Oh, dear.  A previous attempt to write the
5287 		 * superblock failed.  This could happen because the
5288 		 * USB device was yanked out.  Or it could happen to
5289 		 * be a transient write error and maybe the block will
5290 		 * be remapped.  Nothing we can do but to retry the
5291 		 * write and hope for the best.
5292 		 */
5293 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5294 		       "superblock detected");
5295 		clear_buffer_write_io_error(sbh);
5296 		set_buffer_uptodate(sbh);
5297 	}
5298 	mark_buffer_dirty(sbh);
5299 	if (sync) {
5300 		unlock_buffer(sbh);
5301 		error = __sync_dirty_buffer(sbh,
5302 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5303 		if (buffer_write_io_error(sbh)) {
5304 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5305 			       "superblock");
5306 			clear_buffer_write_io_error(sbh);
5307 			set_buffer_uptodate(sbh);
5308 		}
5309 	}
5310 	return error;
5311 }
5312 
5313 /*
5314  * Have we just finished recovery?  If so, and if we are mounting (or
5315  * remounting) the filesystem readonly, then we will end up with a
5316  * consistent fs on disk.  Record that fact.
5317  */
5318 static int ext4_mark_recovery_complete(struct super_block *sb,
5319 				       struct ext4_super_block *es)
5320 {
5321 	int err;
5322 	journal_t *journal = EXT4_SB(sb)->s_journal;
5323 
5324 	if (!ext4_has_feature_journal(sb)) {
5325 		if (journal != NULL) {
5326 			ext4_error(sb, "Journal got removed while the fs was "
5327 				   "mounted!");
5328 			return -EFSCORRUPTED;
5329 		}
5330 		return 0;
5331 	}
5332 	jbd2_journal_lock_updates(journal);
5333 	err = jbd2_journal_flush(journal);
5334 	if (err < 0)
5335 		goto out;
5336 
5337 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5338 		ext4_clear_feature_journal_needs_recovery(sb);
5339 		ext4_commit_super(sb, 1);
5340 	}
5341 out:
5342 	jbd2_journal_unlock_updates(journal);
5343 	return err;
5344 }
5345 
5346 /*
5347  * If we are mounting (or read-write remounting) a filesystem whose journal
5348  * has recorded an error from a previous lifetime, move that error to the
5349  * main filesystem now.
5350  */
5351 static int ext4_clear_journal_err(struct super_block *sb,
5352 				   struct ext4_super_block *es)
5353 {
5354 	journal_t *journal;
5355 	int j_errno;
5356 	const char *errstr;
5357 
5358 	if (!ext4_has_feature_journal(sb)) {
5359 		ext4_error(sb, "Journal got removed while the fs was mounted!");
5360 		return -EFSCORRUPTED;
5361 	}
5362 
5363 	journal = EXT4_SB(sb)->s_journal;
5364 
5365 	/*
5366 	 * Now check for any error status which may have been recorded in the
5367 	 * journal by a prior ext4_error() or ext4_abort()
5368 	 */
5369 
5370 	j_errno = jbd2_journal_errno(journal);
5371 	if (j_errno) {
5372 		char nbuf[16];
5373 
5374 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5375 		ext4_warning(sb, "Filesystem error recorded "
5376 			     "from previous mount: %s", errstr);
5377 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5378 
5379 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5380 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5381 		ext4_commit_super(sb, 1);
5382 
5383 		jbd2_journal_clear_err(journal);
5384 		jbd2_journal_update_sb_errno(journal);
5385 	}
5386 	return 0;
5387 }
5388 
5389 /*
5390  * Force the running and committing transactions to commit,
5391  * and wait on the commit.
5392  */
5393 int ext4_force_commit(struct super_block *sb)
5394 {
5395 	journal_t *journal;
5396 
5397 	if (sb_rdonly(sb))
5398 		return 0;
5399 
5400 	journal = EXT4_SB(sb)->s_journal;
5401 	return ext4_journal_force_commit(journal);
5402 }
5403 
5404 static int ext4_sync_fs(struct super_block *sb, int wait)
5405 {
5406 	int ret = 0;
5407 	tid_t target;
5408 	bool needs_barrier = false;
5409 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5410 
5411 	if (unlikely(ext4_forced_shutdown(sbi)))
5412 		return 0;
5413 
5414 	trace_ext4_sync_fs(sb, wait);
5415 	flush_workqueue(sbi->rsv_conversion_wq);
5416 	/*
5417 	 * Writeback quota in non-journalled quota case - journalled quota has
5418 	 * no dirty dquots
5419 	 */
5420 	dquot_writeback_dquots(sb, -1);
5421 	/*
5422 	 * Data writeback is possible w/o journal transaction, so barrier must
5423 	 * being sent at the end of the function. But we can skip it if
5424 	 * transaction_commit will do it for us.
5425 	 */
5426 	if (sbi->s_journal) {
5427 		target = jbd2_get_latest_transaction(sbi->s_journal);
5428 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5429 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5430 			needs_barrier = true;
5431 
5432 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5433 			if (wait)
5434 				ret = jbd2_log_wait_commit(sbi->s_journal,
5435 							   target);
5436 		}
5437 	} else if (wait && test_opt(sb, BARRIER))
5438 		needs_barrier = true;
5439 	if (needs_barrier) {
5440 		int err;
5441 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL);
5442 		if (!ret)
5443 			ret = err;
5444 	}
5445 
5446 	return ret;
5447 }
5448 
5449 /*
5450  * LVM calls this function before a (read-only) snapshot is created.  This
5451  * gives us a chance to flush the journal completely and mark the fs clean.
5452  *
5453  * Note that only this function cannot bring a filesystem to be in a clean
5454  * state independently. It relies on upper layer to stop all data & metadata
5455  * modifications.
5456  */
5457 static int ext4_freeze(struct super_block *sb)
5458 {
5459 	int error = 0;
5460 	journal_t *journal;
5461 
5462 	if (sb_rdonly(sb))
5463 		return 0;
5464 
5465 	journal = EXT4_SB(sb)->s_journal;
5466 
5467 	if (journal) {
5468 		/* Now we set up the journal barrier. */
5469 		jbd2_journal_lock_updates(journal);
5470 
5471 		/*
5472 		 * Don't clear the needs_recovery flag if we failed to
5473 		 * flush the journal.
5474 		 */
5475 		error = jbd2_journal_flush(journal);
5476 		if (error < 0)
5477 			goto out;
5478 
5479 		/* Journal blocked and flushed, clear needs_recovery flag. */
5480 		ext4_clear_feature_journal_needs_recovery(sb);
5481 	}
5482 
5483 	error = ext4_commit_super(sb, 1);
5484 out:
5485 	if (journal)
5486 		/* we rely on upper layer to stop further updates */
5487 		jbd2_journal_unlock_updates(journal);
5488 	return error;
5489 }
5490 
5491 /*
5492  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5493  * flag here, even though the filesystem is not technically dirty yet.
5494  */
5495 static int ext4_unfreeze(struct super_block *sb)
5496 {
5497 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5498 		return 0;
5499 
5500 	if (EXT4_SB(sb)->s_journal) {
5501 		/* Reset the needs_recovery flag before the fs is unlocked. */
5502 		ext4_set_feature_journal_needs_recovery(sb);
5503 	}
5504 
5505 	ext4_commit_super(sb, 1);
5506 	return 0;
5507 }
5508 
5509 /*
5510  * Structure to save mount options for ext4_remount's benefit
5511  */
5512 struct ext4_mount_options {
5513 	unsigned long s_mount_opt;
5514 	unsigned long s_mount_opt2;
5515 	kuid_t s_resuid;
5516 	kgid_t s_resgid;
5517 	unsigned long s_commit_interval;
5518 	u32 s_min_batch_time, s_max_batch_time;
5519 #ifdef CONFIG_QUOTA
5520 	int s_jquota_fmt;
5521 	char *s_qf_names[EXT4_MAXQUOTAS];
5522 #endif
5523 };
5524 
5525 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5526 {
5527 	struct ext4_super_block *es;
5528 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5529 	unsigned long old_sb_flags, vfs_flags;
5530 	struct ext4_mount_options old_opts;
5531 	int enable_quota = 0;
5532 	ext4_group_t g;
5533 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5534 	int err = 0;
5535 #ifdef CONFIG_QUOTA
5536 	int i, j;
5537 	char *to_free[EXT4_MAXQUOTAS];
5538 #endif
5539 	char *orig_data = kstrdup(data, GFP_KERNEL);
5540 
5541 	if (data && !orig_data)
5542 		return -ENOMEM;
5543 
5544 	/* Store the original options */
5545 	old_sb_flags = sb->s_flags;
5546 	old_opts.s_mount_opt = sbi->s_mount_opt;
5547 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5548 	old_opts.s_resuid = sbi->s_resuid;
5549 	old_opts.s_resgid = sbi->s_resgid;
5550 	old_opts.s_commit_interval = sbi->s_commit_interval;
5551 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5552 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5553 #ifdef CONFIG_QUOTA
5554 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5555 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5556 		if (sbi->s_qf_names[i]) {
5557 			char *qf_name = get_qf_name(sb, sbi, i);
5558 
5559 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5560 			if (!old_opts.s_qf_names[i]) {
5561 				for (j = 0; j < i; j++)
5562 					kfree(old_opts.s_qf_names[j]);
5563 				kfree(orig_data);
5564 				return -ENOMEM;
5565 			}
5566 		} else
5567 			old_opts.s_qf_names[i] = NULL;
5568 #endif
5569 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5570 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5571 
5572 	/*
5573 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5574 	 * either way we need to make sure it matches in both *flags and
5575 	 * s_flags. Copy those selected flags from *flags to s_flags
5576 	 */
5577 	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
5578 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
5579 
5580 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5581 		err = -EINVAL;
5582 		goto restore_opts;
5583 	}
5584 
5585 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5586 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5587 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5588 			 "during remount not supported; ignoring");
5589 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5590 	}
5591 
5592 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5593 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5594 			ext4_msg(sb, KERN_ERR, "can't mount with "
5595 				 "both data=journal and delalloc");
5596 			err = -EINVAL;
5597 			goto restore_opts;
5598 		}
5599 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5600 			ext4_msg(sb, KERN_ERR, "can't mount with "
5601 				 "both data=journal and dioread_nolock");
5602 			err = -EINVAL;
5603 			goto restore_opts;
5604 		}
5605 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5606 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5607 			ext4_msg(sb, KERN_ERR, "can't mount with "
5608 				"journal_async_commit in data=ordered mode");
5609 			err = -EINVAL;
5610 			goto restore_opts;
5611 		}
5612 	}
5613 
5614 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5615 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5616 		err = -EINVAL;
5617 		goto restore_opts;
5618 	}
5619 
5620 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5621 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5622 
5623 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5624 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5625 
5626 	es = sbi->s_es;
5627 
5628 	if (sbi->s_journal) {
5629 		ext4_init_journal_params(sb, sbi->s_journal);
5630 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5631 	}
5632 
5633 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5634 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5635 			err = -EROFS;
5636 			goto restore_opts;
5637 		}
5638 
5639 		if (*flags & SB_RDONLY) {
5640 			err = sync_filesystem(sb);
5641 			if (err < 0)
5642 				goto restore_opts;
5643 			err = dquot_suspend(sb, -1);
5644 			if (err < 0)
5645 				goto restore_opts;
5646 
5647 			/*
5648 			 * First of all, the unconditional stuff we have to do
5649 			 * to disable replay of the journal when we next remount
5650 			 */
5651 			sb->s_flags |= SB_RDONLY;
5652 
5653 			/*
5654 			 * OK, test if we are remounting a valid rw partition
5655 			 * readonly, and if so set the rdonly flag and then
5656 			 * mark the partition as valid again.
5657 			 */
5658 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5659 			    (sbi->s_mount_state & EXT4_VALID_FS))
5660 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5661 
5662 			if (sbi->s_journal) {
5663 				/*
5664 				 * We let remount-ro finish even if marking fs
5665 				 * as clean failed...
5666 				 */
5667 				ext4_mark_recovery_complete(sb, es);
5668 			}
5669 			if (sbi->s_mmp_tsk)
5670 				kthread_stop(sbi->s_mmp_tsk);
5671 		} else {
5672 			/* Make sure we can mount this feature set readwrite */
5673 			if (ext4_has_feature_readonly(sb) ||
5674 			    !ext4_feature_set_ok(sb, 0)) {
5675 				err = -EROFS;
5676 				goto restore_opts;
5677 			}
5678 			/*
5679 			 * Make sure the group descriptor checksums
5680 			 * are sane.  If they aren't, refuse to remount r/w.
5681 			 */
5682 			for (g = 0; g < sbi->s_groups_count; g++) {
5683 				struct ext4_group_desc *gdp =
5684 					ext4_get_group_desc(sb, g, NULL);
5685 
5686 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5687 					ext4_msg(sb, KERN_ERR,
5688 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5689 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5690 					       le16_to_cpu(gdp->bg_checksum));
5691 					err = -EFSBADCRC;
5692 					goto restore_opts;
5693 				}
5694 			}
5695 
5696 			/*
5697 			 * If we have an unprocessed orphan list hanging
5698 			 * around from a previously readonly bdev mount,
5699 			 * require a full umount/remount for now.
5700 			 */
5701 			if (es->s_last_orphan) {
5702 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5703 				       "remount RDWR because of unprocessed "
5704 				       "orphan inode list.  Please "
5705 				       "umount/remount instead");
5706 				err = -EINVAL;
5707 				goto restore_opts;
5708 			}
5709 
5710 			/*
5711 			 * Update the original bdev mapping's wb_err value
5712 			 * which could be used to detect the metadata async
5713 			 * write error.
5714 			 */
5715 			errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5716 						 &sbi->s_bdev_wb_err);
5717 
5718 			/*
5719 			 * Mounting a RDONLY partition read-write, so reread
5720 			 * and store the current valid flag.  (It may have
5721 			 * been changed by e2fsck since we originally mounted
5722 			 * the partition.)
5723 			 */
5724 			if (sbi->s_journal) {
5725 				err = ext4_clear_journal_err(sb, es);
5726 				if (err)
5727 					goto restore_opts;
5728 			}
5729 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5730 
5731 			err = ext4_setup_super(sb, es, 0);
5732 			if (err)
5733 				goto restore_opts;
5734 
5735 			sb->s_flags &= ~SB_RDONLY;
5736 			if (ext4_has_feature_mmp(sb))
5737 				if (ext4_multi_mount_protect(sb,
5738 						le64_to_cpu(es->s_mmp_block))) {
5739 					err = -EROFS;
5740 					goto restore_opts;
5741 				}
5742 			enable_quota = 1;
5743 		}
5744 	}
5745 
5746 	/*
5747 	 * Reinitialize lazy itable initialization thread based on
5748 	 * current settings
5749 	 */
5750 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5751 		ext4_unregister_li_request(sb);
5752 	else {
5753 		ext4_group_t first_not_zeroed;
5754 		first_not_zeroed = ext4_has_uninit_itable(sb);
5755 		ext4_register_li_request(sb, first_not_zeroed);
5756 	}
5757 
5758 	/*
5759 	 * Handle creation of system zone data early because it can fail.
5760 	 * Releasing of existing data is done when we are sure remount will
5761 	 * succeed.
5762 	 */
5763 	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->system_blks) {
5764 		err = ext4_setup_system_zone(sb);
5765 		if (err)
5766 			goto restore_opts;
5767 	}
5768 
5769 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5770 		err = ext4_commit_super(sb, 1);
5771 		if (err)
5772 			goto restore_opts;
5773 	}
5774 
5775 #ifdef CONFIG_QUOTA
5776 	/* Release old quota file names */
5777 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5778 		kfree(old_opts.s_qf_names[i]);
5779 	if (enable_quota) {
5780 		if (sb_any_quota_suspended(sb))
5781 			dquot_resume(sb, -1);
5782 		else if (ext4_has_feature_quota(sb)) {
5783 			err = ext4_enable_quotas(sb);
5784 			if (err)
5785 				goto restore_opts;
5786 		}
5787 	}
5788 #endif
5789 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->system_blks)
5790 		ext4_release_system_zone(sb);
5791 
5792 	/*
5793 	 * Some options can be enabled by ext4 and/or by VFS mount flag
5794 	 * either way we need to make sure it matches in both *flags and
5795 	 * s_flags. Copy those selected flags from s_flags to *flags
5796 	 */
5797 	*flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
5798 
5799 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5800 	kfree(orig_data);
5801 	return 0;
5802 
5803 restore_opts:
5804 	sb->s_flags = old_sb_flags;
5805 	sbi->s_mount_opt = old_opts.s_mount_opt;
5806 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5807 	sbi->s_resuid = old_opts.s_resuid;
5808 	sbi->s_resgid = old_opts.s_resgid;
5809 	sbi->s_commit_interval = old_opts.s_commit_interval;
5810 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5811 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5812 	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->system_blks)
5813 		ext4_release_system_zone(sb);
5814 #ifdef CONFIG_QUOTA
5815 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5816 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5817 		to_free[i] = get_qf_name(sb, sbi, i);
5818 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5819 	}
5820 	synchronize_rcu();
5821 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5822 		kfree(to_free[i]);
5823 #endif
5824 	kfree(orig_data);
5825 	return err;
5826 }
5827 
5828 #ifdef CONFIG_QUOTA
5829 static int ext4_statfs_project(struct super_block *sb,
5830 			       kprojid_t projid, struct kstatfs *buf)
5831 {
5832 	struct kqid qid;
5833 	struct dquot *dquot;
5834 	u64 limit;
5835 	u64 curblock;
5836 
5837 	qid = make_kqid_projid(projid);
5838 	dquot = dqget(sb, qid);
5839 	if (IS_ERR(dquot))
5840 		return PTR_ERR(dquot);
5841 	spin_lock(&dquot->dq_dqb_lock);
5842 
5843 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
5844 			     dquot->dq_dqb.dqb_bhardlimit);
5845 	limit >>= sb->s_blocksize_bits;
5846 
5847 	if (limit && buf->f_blocks > limit) {
5848 		curblock = (dquot->dq_dqb.dqb_curspace +
5849 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5850 		buf->f_blocks = limit;
5851 		buf->f_bfree = buf->f_bavail =
5852 			(buf->f_blocks > curblock) ?
5853 			 (buf->f_blocks - curblock) : 0;
5854 	}
5855 
5856 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
5857 			     dquot->dq_dqb.dqb_ihardlimit);
5858 	if (limit && buf->f_files > limit) {
5859 		buf->f_files = limit;
5860 		buf->f_ffree =
5861 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5862 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5863 	}
5864 
5865 	spin_unlock(&dquot->dq_dqb_lock);
5866 	dqput(dquot);
5867 	return 0;
5868 }
5869 #endif
5870 
5871 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5872 {
5873 	struct super_block *sb = dentry->d_sb;
5874 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5875 	struct ext4_super_block *es = sbi->s_es;
5876 	ext4_fsblk_t overhead = 0, resv_blocks;
5877 	u64 fsid;
5878 	s64 bfree;
5879 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5880 
5881 	if (!test_opt(sb, MINIX_DF))
5882 		overhead = sbi->s_overhead;
5883 
5884 	buf->f_type = EXT4_SUPER_MAGIC;
5885 	buf->f_bsize = sb->s_blocksize;
5886 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5887 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5888 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5889 	/* prevent underflow in case that few free space is available */
5890 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5891 	buf->f_bavail = buf->f_bfree -
5892 			(ext4_r_blocks_count(es) + resv_blocks);
5893 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5894 		buf->f_bavail = 0;
5895 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5896 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5897 	buf->f_namelen = EXT4_NAME_LEN;
5898 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5899 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5900 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5901 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5902 
5903 #ifdef CONFIG_QUOTA
5904 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5905 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5906 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5907 #endif
5908 	return 0;
5909 }
5910 
5911 
5912 #ifdef CONFIG_QUOTA
5913 
5914 /*
5915  * Helper functions so that transaction is started before we acquire dqio_sem
5916  * to keep correct lock ordering of transaction > dqio_sem
5917  */
5918 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5919 {
5920 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5921 }
5922 
5923 static int ext4_write_dquot(struct dquot *dquot)
5924 {
5925 	int ret, err;
5926 	handle_t *handle;
5927 	struct inode *inode;
5928 
5929 	inode = dquot_to_inode(dquot);
5930 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5931 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5932 	if (IS_ERR(handle))
5933 		return PTR_ERR(handle);
5934 	ret = dquot_commit(dquot);
5935 	err = ext4_journal_stop(handle);
5936 	if (!ret)
5937 		ret = err;
5938 	return ret;
5939 }
5940 
5941 static int ext4_acquire_dquot(struct dquot *dquot)
5942 {
5943 	int ret, err;
5944 	handle_t *handle;
5945 
5946 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5947 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5948 	if (IS_ERR(handle))
5949 		return PTR_ERR(handle);
5950 	ret = dquot_acquire(dquot);
5951 	err = ext4_journal_stop(handle);
5952 	if (!ret)
5953 		ret = err;
5954 	return ret;
5955 }
5956 
5957 static int ext4_release_dquot(struct dquot *dquot)
5958 {
5959 	int ret, err;
5960 	handle_t *handle;
5961 
5962 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5963 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5964 	if (IS_ERR(handle)) {
5965 		/* Release dquot anyway to avoid endless cycle in dqput() */
5966 		dquot_release(dquot);
5967 		return PTR_ERR(handle);
5968 	}
5969 	ret = dquot_release(dquot);
5970 	err = ext4_journal_stop(handle);
5971 	if (!ret)
5972 		ret = err;
5973 	return ret;
5974 }
5975 
5976 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5977 {
5978 	struct super_block *sb = dquot->dq_sb;
5979 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5980 
5981 	/* Are we journaling quotas? */
5982 	if (ext4_has_feature_quota(sb) ||
5983 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5984 		dquot_mark_dquot_dirty(dquot);
5985 		return ext4_write_dquot(dquot);
5986 	} else {
5987 		return dquot_mark_dquot_dirty(dquot);
5988 	}
5989 }
5990 
5991 static int ext4_write_info(struct super_block *sb, int type)
5992 {
5993 	int ret, err;
5994 	handle_t *handle;
5995 
5996 	/* Data block + inode block */
5997 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5998 	if (IS_ERR(handle))
5999 		return PTR_ERR(handle);
6000 	ret = dquot_commit_info(sb, type);
6001 	err = ext4_journal_stop(handle);
6002 	if (!ret)
6003 		ret = err;
6004 	return ret;
6005 }
6006 
6007 /*
6008  * Turn on quotas during mount time - we need to find
6009  * the quota file and such...
6010  */
6011 static int ext4_quota_on_mount(struct super_block *sb, int type)
6012 {
6013 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
6014 					EXT4_SB(sb)->s_jquota_fmt, type);
6015 }
6016 
6017 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6018 {
6019 	struct ext4_inode_info *ei = EXT4_I(inode);
6020 
6021 	/* The first argument of lockdep_set_subclass has to be
6022 	 * *exactly* the same as the argument to init_rwsem() --- in
6023 	 * this case, in init_once() --- or lockdep gets unhappy
6024 	 * because the name of the lock is set using the
6025 	 * stringification of the argument to init_rwsem().
6026 	 */
6027 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
6028 	lockdep_set_subclass(&ei->i_data_sem, subclass);
6029 }
6030 
6031 /*
6032  * Standard function to be called on quota_on
6033  */
6034 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6035 			 const struct path *path)
6036 {
6037 	int err;
6038 
6039 	if (!test_opt(sb, QUOTA))
6040 		return -EINVAL;
6041 
6042 	/* Quotafile not on the same filesystem? */
6043 	if (path->dentry->d_sb != sb)
6044 		return -EXDEV;
6045 	/* Journaling quota? */
6046 	if (EXT4_SB(sb)->s_qf_names[type]) {
6047 		/* Quotafile not in fs root? */
6048 		if (path->dentry->d_parent != sb->s_root)
6049 			ext4_msg(sb, KERN_WARNING,
6050 				"Quota file not on filesystem root. "
6051 				"Journaled quota will not work");
6052 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6053 	} else {
6054 		/*
6055 		 * Clear the flag just in case mount options changed since
6056 		 * last time.
6057 		 */
6058 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6059 	}
6060 
6061 	/*
6062 	 * When we journal data on quota file, we have to flush journal to see
6063 	 * all updates to the file when we bypass pagecache...
6064 	 */
6065 	if (EXT4_SB(sb)->s_journal &&
6066 	    ext4_should_journal_data(d_inode(path->dentry))) {
6067 		/*
6068 		 * We don't need to lock updates but journal_flush() could
6069 		 * otherwise be livelocked...
6070 		 */
6071 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6072 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
6073 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6074 		if (err)
6075 			return err;
6076 	}
6077 
6078 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6079 	err = dquot_quota_on(sb, type, format_id, path);
6080 	if (err) {
6081 		lockdep_set_quota_inode(path->dentry->d_inode,
6082 					     I_DATA_SEM_NORMAL);
6083 	} else {
6084 		struct inode *inode = d_inode(path->dentry);
6085 		handle_t *handle;
6086 
6087 		/*
6088 		 * Set inode flags to prevent userspace from messing with quota
6089 		 * files. If this fails, we return success anyway since quotas
6090 		 * are already enabled and this is not a hard failure.
6091 		 */
6092 		inode_lock(inode);
6093 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6094 		if (IS_ERR(handle))
6095 			goto unlock_inode;
6096 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6097 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6098 				S_NOATIME | S_IMMUTABLE);
6099 		err = ext4_mark_inode_dirty(handle, inode);
6100 		ext4_journal_stop(handle);
6101 	unlock_inode:
6102 		inode_unlock(inode);
6103 	}
6104 	return err;
6105 }
6106 
6107 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6108 			     unsigned int flags)
6109 {
6110 	int err;
6111 	struct inode *qf_inode;
6112 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6113 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6114 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6115 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6116 	};
6117 
6118 	BUG_ON(!ext4_has_feature_quota(sb));
6119 
6120 	if (!qf_inums[type])
6121 		return -EPERM;
6122 
6123 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6124 	if (IS_ERR(qf_inode)) {
6125 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6126 		return PTR_ERR(qf_inode);
6127 	}
6128 
6129 	/* Don't account quota for quota files to avoid recursion */
6130 	qf_inode->i_flags |= S_NOQUOTA;
6131 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6132 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6133 	if (err)
6134 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6135 	iput(qf_inode);
6136 
6137 	return err;
6138 }
6139 
6140 /* Enable usage tracking for all quota types. */
6141 static int ext4_enable_quotas(struct super_block *sb)
6142 {
6143 	int type, err = 0;
6144 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6145 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6146 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6147 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6148 	};
6149 	bool quota_mopt[EXT4_MAXQUOTAS] = {
6150 		test_opt(sb, USRQUOTA),
6151 		test_opt(sb, GRPQUOTA),
6152 		test_opt(sb, PRJQUOTA),
6153 	};
6154 
6155 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6156 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6157 		if (qf_inums[type]) {
6158 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6159 				DQUOT_USAGE_ENABLED |
6160 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6161 			if (err) {
6162 				ext4_warning(sb,
6163 					"Failed to enable quota tracking "
6164 					"(type=%d, err=%d). Please run "
6165 					"e2fsck to fix.", type, err);
6166 				for (type--; type >= 0; type--)
6167 					dquot_quota_off(sb, type);
6168 
6169 				return err;
6170 			}
6171 		}
6172 	}
6173 	return 0;
6174 }
6175 
6176 static int ext4_quota_off(struct super_block *sb, int type)
6177 {
6178 	struct inode *inode = sb_dqopt(sb)->files[type];
6179 	handle_t *handle;
6180 	int err;
6181 
6182 	/* Force all delayed allocation blocks to be allocated.
6183 	 * Caller already holds s_umount sem */
6184 	if (test_opt(sb, DELALLOC))
6185 		sync_filesystem(sb);
6186 
6187 	if (!inode || !igrab(inode))
6188 		goto out;
6189 
6190 	err = dquot_quota_off(sb, type);
6191 	if (err || ext4_has_feature_quota(sb))
6192 		goto out_put;
6193 
6194 	inode_lock(inode);
6195 	/*
6196 	 * Update modification times of quota files when userspace can
6197 	 * start looking at them. If we fail, we return success anyway since
6198 	 * this is not a hard failure and quotas are already disabled.
6199 	 */
6200 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6201 	if (IS_ERR(handle)) {
6202 		err = PTR_ERR(handle);
6203 		goto out_unlock;
6204 	}
6205 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6206 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6207 	inode->i_mtime = inode->i_ctime = current_time(inode);
6208 	err = ext4_mark_inode_dirty(handle, inode);
6209 	ext4_journal_stop(handle);
6210 out_unlock:
6211 	inode_unlock(inode);
6212 out_put:
6213 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6214 	iput(inode);
6215 	return err;
6216 out:
6217 	return dquot_quota_off(sb, type);
6218 }
6219 
6220 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6221  * acquiring the locks... As quota files are never truncated and quota code
6222  * itself serializes the operations (and no one else should touch the files)
6223  * we don't have to be afraid of races */
6224 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6225 			       size_t len, loff_t off)
6226 {
6227 	struct inode *inode = sb_dqopt(sb)->files[type];
6228 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6229 	int offset = off & (sb->s_blocksize - 1);
6230 	int tocopy;
6231 	size_t toread;
6232 	struct buffer_head *bh;
6233 	loff_t i_size = i_size_read(inode);
6234 
6235 	if (off > i_size)
6236 		return 0;
6237 	if (off+len > i_size)
6238 		len = i_size-off;
6239 	toread = len;
6240 	while (toread > 0) {
6241 		tocopy = sb->s_blocksize - offset < toread ?
6242 				sb->s_blocksize - offset : toread;
6243 		bh = ext4_bread(NULL, inode, blk, 0);
6244 		if (IS_ERR(bh))
6245 			return PTR_ERR(bh);
6246 		if (!bh)	/* A hole? */
6247 			memset(data, 0, tocopy);
6248 		else
6249 			memcpy(data, bh->b_data+offset, tocopy);
6250 		brelse(bh);
6251 		offset = 0;
6252 		toread -= tocopy;
6253 		data += tocopy;
6254 		blk++;
6255 	}
6256 	return len;
6257 }
6258 
6259 /* Write to quotafile (we know the transaction is already started and has
6260  * enough credits) */
6261 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6262 				const char *data, size_t len, loff_t off)
6263 {
6264 	struct inode *inode = sb_dqopt(sb)->files[type];
6265 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6266 	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6267 	int retries = 0;
6268 	struct buffer_head *bh;
6269 	handle_t *handle = journal_current_handle();
6270 
6271 	if (EXT4_SB(sb)->s_journal && !handle) {
6272 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6273 			" cancelled because transaction is not started",
6274 			(unsigned long long)off, (unsigned long long)len);
6275 		return -EIO;
6276 	}
6277 	/*
6278 	 * Since we account only one data block in transaction credits,
6279 	 * then it is impossible to cross a block boundary.
6280 	 */
6281 	if (sb->s_blocksize - offset < len) {
6282 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6283 			" cancelled because not block aligned",
6284 			(unsigned long long)off, (unsigned long long)len);
6285 		return -EIO;
6286 	}
6287 
6288 	do {
6289 		bh = ext4_bread(handle, inode, blk,
6290 				EXT4_GET_BLOCKS_CREATE |
6291 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6292 	} while (PTR_ERR(bh) == -ENOSPC &&
6293 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6294 	if (IS_ERR(bh))
6295 		return PTR_ERR(bh);
6296 	if (!bh)
6297 		goto out;
6298 	BUFFER_TRACE(bh, "get write access");
6299 	err = ext4_journal_get_write_access(handle, bh);
6300 	if (err) {
6301 		brelse(bh);
6302 		return err;
6303 	}
6304 	lock_buffer(bh);
6305 	memcpy(bh->b_data+offset, data, len);
6306 	flush_dcache_page(bh->b_page);
6307 	unlock_buffer(bh);
6308 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6309 	brelse(bh);
6310 out:
6311 	if (inode->i_size < off + len) {
6312 		i_size_write(inode, off + len);
6313 		EXT4_I(inode)->i_disksize = inode->i_size;
6314 		err2 = ext4_mark_inode_dirty(handle, inode);
6315 		if (unlikely(err2 && !err))
6316 			err = err2;
6317 	}
6318 	return err ? err : len;
6319 }
6320 #endif
6321 
6322 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6323 		       const char *dev_name, void *data)
6324 {
6325 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6326 }
6327 
6328 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6329 static inline void register_as_ext2(void)
6330 {
6331 	int err = register_filesystem(&ext2_fs_type);
6332 	if (err)
6333 		printk(KERN_WARNING
6334 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6335 }
6336 
6337 static inline void unregister_as_ext2(void)
6338 {
6339 	unregister_filesystem(&ext2_fs_type);
6340 }
6341 
6342 static inline int ext2_feature_set_ok(struct super_block *sb)
6343 {
6344 	if (ext4_has_unknown_ext2_incompat_features(sb))
6345 		return 0;
6346 	if (sb_rdonly(sb))
6347 		return 1;
6348 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6349 		return 0;
6350 	return 1;
6351 }
6352 #else
6353 static inline void register_as_ext2(void) { }
6354 static inline void unregister_as_ext2(void) { }
6355 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6356 #endif
6357 
6358 static inline void register_as_ext3(void)
6359 {
6360 	int err = register_filesystem(&ext3_fs_type);
6361 	if (err)
6362 		printk(KERN_WARNING
6363 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6364 }
6365 
6366 static inline void unregister_as_ext3(void)
6367 {
6368 	unregister_filesystem(&ext3_fs_type);
6369 }
6370 
6371 static inline int ext3_feature_set_ok(struct super_block *sb)
6372 {
6373 	if (ext4_has_unknown_ext3_incompat_features(sb))
6374 		return 0;
6375 	if (!ext4_has_feature_journal(sb))
6376 		return 0;
6377 	if (sb_rdonly(sb))
6378 		return 1;
6379 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6380 		return 0;
6381 	return 1;
6382 }
6383 
6384 static struct file_system_type ext4_fs_type = {
6385 	.owner		= THIS_MODULE,
6386 	.name		= "ext4",
6387 	.mount		= ext4_mount,
6388 	.kill_sb	= kill_block_super,
6389 	.fs_flags	= FS_REQUIRES_DEV,
6390 };
6391 MODULE_ALIAS_FS("ext4");
6392 
6393 /* Shared across all ext4 file systems */
6394 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6395 
6396 static int __init ext4_init_fs(void)
6397 {
6398 	int i, err;
6399 
6400 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6401 	ext4_li_info = NULL;
6402 	mutex_init(&ext4_li_mtx);
6403 
6404 	/* Build-time check for flags consistency */
6405 	ext4_check_flag_values();
6406 
6407 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6408 		init_waitqueue_head(&ext4__ioend_wq[i]);
6409 
6410 	err = ext4_init_es();
6411 	if (err)
6412 		return err;
6413 
6414 	err = ext4_init_pending();
6415 	if (err)
6416 		goto out7;
6417 
6418 	err = ext4_init_post_read_processing();
6419 	if (err)
6420 		goto out6;
6421 
6422 	err = ext4_init_pageio();
6423 	if (err)
6424 		goto out5;
6425 
6426 	err = ext4_init_system_zone();
6427 	if (err)
6428 		goto out4;
6429 
6430 	err = ext4_init_sysfs();
6431 	if (err)
6432 		goto out3;
6433 
6434 	err = ext4_init_mballoc();
6435 	if (err)
6436 		goto out2;
6437 	err = init_inodecache();
6438 	if (err)
6439 		goto out1;
6440 	register_as_ext3();
6441 	register_as_ext2();
6442 	err = register_filesystem(&ext4_fs_type);
6443 	if (err)
6444 		goto out;
6445 
6446 	return 0;
6447 out:
6448 	unregister_as_ext2();
6449 	unregister_as_ext3();
6450 	destroy_inodecache();
6451 out1:
6452 	ext4_exit_mballoc();
6453 out2:
6454 	ext4_exit_sysfs();
6455 out3:
6456 	ext4_exit_system_zone();
6457 out4:
6458 	ext4_exit_pageio();
6459 out5:
6460 	ext4_exit_post_read_processing();
6461 out6:
6462 	ext4_exit_pending();
6463 out7:
6464 	ext4_exit_es();
6465 
6466 	return err;
6467 }
6468 
6469 static void __exit ext4_exit_fs(void)
6470 {
6471 	ext4_destroy_lazyinit_thread();
6472 	unregister_as_ext2();
6473 	unregister_as_ext3();
6474 	unregister_filesystem(&ext4_fs_type);
6475 	destroy_inodecache();
6476 	ext4_exit_mballoc();
6477 	ext4_exit_sysfs();
6478 	ext4_exit_system_zone();
6479 	ext4_exit_pageio();
6480 	ext4_exit_post_read_processing();
6481 	ext4_exit_es();
6482 	ext4_exit_pending();
6483 }
6484 
6485 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6486 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6487 MODULE_LICENSE("GPL");
6488 MODULE_SOFTDEP("pre: crc32c");
6489 module_init(ext4_init_fs)
6490 module_exit(ext4_exit_fs)
6491