xref: /linux/fs/ext4/super.c (revision 37744feebc086908fd89760650f458ab19071750)
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 void ext4_mark_recovery_complete(struct super_block *sb,
70 					struct ext4_super_block *es);
71 static void 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_sem -> 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_sem
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_sem
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 		if (EXT4_SB(sb)->s_journal &&
526 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
527 			return;
528 		panic("EXT4-fs (device %s): panic forced after error\n",
529 			sb->s_id);
530 	}
531 }
532 
533 #define ext4_error_ratelimit(sb)					\
534 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
535 			     "EXT4-fs error")
536 
537 void __ext4_error(struct super_block *sb, const char *function,
538 		  unsigned int line, int error, __u64 block,
539 		  const char *fmt, ...)
540 {
541 	struct va_format vaf;
542 	va_list args;
543 
544 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
545 		return;
546 
547 	trace_ext4_error(sb, function, line);
548 	if (ext4_error_ratelimit(sb)) {
549 		va_start(args, fmt);
550 		vaf.fmt = fmt;
551 		vaf.va = &args;
552 		printk(KERN_CRIT
553 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
554 		       sb->s_id, function, line, current->comm, &vaf);
555 		va_end(args);
556 	}
557 	save_error_info(sb, error, 0, block, function, line);
558 	ext4_handle_error(sb);
559 }
560 
561 void __ext4_error_inode(struct inode *inode, const char *function,
562 			unsigned int line, ext4_fsblk_t block, int error,
563 			const char *fmt, ...)
564 {
565 	va_list args;
566 	struct va_format vaf;
567 
568 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
569 		return;
570 
571 	trace_ext4_error(inode->i_sb, function, line);
572 	if (ext4_error_ratelimit(inode->i_sb)) {
573 		va_start(args, fmt);
574 		vaf.fmt = fmt;
575 		vaf.va = &args;
576 		if (block)
577 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
578 			       "inode #%lu: block %llu: comm %s: %pV\n",
579 			       inode->i_sb->s_id, function, line, inode->i_ino,
580 			       block, current->comm, &vaf);
581 		else
582 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
583 			       "inode #%lu: comm %s: %pV\n",
584 			       inode->i_sb->s_id, function, line, inode->i_ino,
585 			       current->comm, &vaf);
586 		va_end(args);
587 	}
588 	save_error_info(inode->i_sb, error, inode->i_ino, block,
589 			function, line);
590 	ext4_handle_error(inode->i_sb);
591 }
592 
593 void __ext4_error_file(struct file *file, const char *function,
594 		       unsigned int line, ext4_fsblk_t block,
595 		       const char *fmt, ...)
596 {
597 	va_list args;
598 	struct va_format vaf;
599 	struct inode *inode = file_inode(file);
600 	char pathname[80], *path;
601 
602 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
603 		return;
604 
605 	trace_ext4_error(inode->i_sb, function, line);
606 	if (ext4_error_ratelimit(inode->i_sb)) {
607 		path = file_path(file, pathname, sizeof(pathname));
608 		if (IS_ERR(path))
609 			path = "(unknown)";
610 		va_start(args, fmt);
611 		vaf.fmt = fmt;
612 		vaf.va = &args;
613 		if (block)
614 			printk(KERN_CRIT
615 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
616 			       "block %llu: comm %s: path %s: %pV\n",
617 			       inode->i_sb->s_id, function, line, inode->i_ino,
618 			       block, current->comm, path, &vaf);
619 		else
620 			printk(KERN_CRIT
621 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
622 			       "comm %s: path %s: %pV\n",
623 			       inode->i_sb->s_id, function, line, inode->i_ino,
624 			       current->comm, path, &vaf);
625 		va_end(args);
626 	}
627 	save_error_info(inode->i_sb, EFSCORRUPTED, inode->i_ino, block,
628 			function, line);
629 	ext4_handle_error(inode->i_sb);
630 }
631 
632 const char *ext4_decode_error(struct super_block *sb, int errno,
633 			      char nbuf[16])
634 {
635 	char *errstr = NULL;
636 
637 	switch (errno) {
638 	case -EFSCORRUPTED:
639 		errstr = "Corrupt filesystem";
640 		break;
641 	case -EFSBADCRC:
642 		errstr = "Filesystem failed CRC";
643 		break;
644 	case -EIO:
645 		errstr = "IO failure";
646 		break;
647 	case -ENOMEM:
648 		errstr = "Out of memory";
649 		break;
650 	case -EROFS:
651 		if (!sb || (EXT4_SB(sb)->s_journal &&
652 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
653 			errstr = "Journal has aborted";
654 		else
655 			errstr = "Readonly filesystem";
656 		break;
657 	default:
658 		/* If the caller passed in an extra buffer for unknown
659 		 * errors, textualise them now.  Else we just return
660 		 * NULL. */
661 		if (nbuf) {
662 			/* Check for truncated error codes... */
663 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
664 				errstr = nbuf;
665 		}
666 		break;
667 	}
668 
669 	return errstr;
670 }
671 
672 /* __ext4_std_error decodes expected errors from journaling functions
673  * automatically and invokes the appropriate error response.  */
674 
675 void __ext4_std_error(struct super_block *sb, const char *function,
676 		      unsigned int line, int errno)
677 {
678 	char nbuf[16];
679 	const char *errstr;
680 
681 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
682 		return;
683 
684 	/* Special case: if the error is EROFS, and we're not already
685 	 * inside a transaction, then there's really no point in logging
686 	 * an error. */
687 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
688 		return;
689 
690 	if (ext4_error_ratelimit(sb)) {
691 		errstr = ext4_decode_error(sb, errno, nbuf);
692 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
693 		       sb->s_id, function, line, errstr);
694 	}
695 
696 	save_error_info(sb, -errno, 0, 0, function, line);
697 	ext4_handle_error(sb);
698 }
699 
700 /*
701  * ext4_abort is a much stronger failure handler than ext4_error.  The
702  * abort function may be used to deal with unrecoverable failures such
703  * as journal IO errors or ENOMEM at a critical moment in log management.
704  *
705  * We unconditionally force the filesystem into an ABORT|READONLY state,
706  * unless the error response on the fs has been set to panic in which
707  * case we take the easy way out and panic immediately.
708  */
709 
710 void __ext4_abort(struct super_block *sb, const char *function,
711 		  unsigned int line, int error, const char *fmt, ...)
712 {
713 	struct va_format vaf;
714 	va_list args;
715 
716 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
717 		return;
718 
719 	save_error_info(sb, error, 0, 0, function, line);
720 	va_start(args, fmt);
721 	vaf.fmt = fmt;
722 	vaf.va = &args;
723 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
724 	       sb->s_id, function, line, &vaf);
725 	va_end(args);
726 
727 	if (sb_rdonly(sb) == 0) {
728 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
729 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
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 		if (EXT4_SB(sb)->s_journal)
737 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
738 	}
739 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
740 		if (EXT4_SB(sb)->s_journal &&
741 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
742 			return;
743 		panic("EXT4-fs panic from previous error\n");
744 	}
745 }
746 
747 void __ext4_msg(struct super_block *sb,
748 		const char *prefix, const char *fmt, ...)
749 {
750 	struct va_format vaf;
751 	va_list args;
752 
753 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
754 		return;
755 
756 	va_start(args, fmt);
757 	vaf.fmt = fmt;
758 	vaf.va = &args;
759 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
760 	va_end(args);
761 }
762 
763 #define ext4_warning_ratelimit(sb)					\
764 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
765 			     "EXT4-fs warning")
766 
767 void __ext4_warning(struct super_block *sb, const char *function,
768 		    unsigned int line, const char *fmt, ...)
769 {
770 	struct va_format vaf;
771 	va_list args;
772 
773 	if (!ext4_warning_ratelimit(sb))
774 		return;
775 
776 	va_start(args, fmt);
777 	vaf.fmt = fmt;
778 	vaf.va = &args;
779 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
780 	       sb->s_id, function, line, &vaf);
781 	va_end(args);
782 }
783 
784 void __ext4_warning_inode(const struct inode *inode, const char *function,
785 			  unsigned int line, const char *fmt, ...)
786 {
787 	struct va_format vaf;
788 	va_list args;
789 
790 	if (!ext4_warning_ratelimit(inode->i_sb))
791 		return;
792 
793 	va_start(args, fmt);
794 	vaf.fmt = fmt;
795 	vaf.va = &args;
796 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
797 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
798 	       function, line, inode->i_ino, current->comm, &vaf);
799 	va_end(args);
800 }
801 
802 void __ext4_grp_locked_error(const char *function, unsigned int line,
803 			     struct super_block *sb, ext4_group_t grp,
804 			     unsigned long ino, ext4_fsblk_t block,
805 			     const char *fmt, ...)
806 __releases(bitlock)
807 __acquires(bitlock)
808 {
809 	struct va_format vaf;
810 	va_list args;
811 
812 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
813 		return;
814 
815 	trace_ext4_error(sb, function, line);
816 	__save_error_info(sb, EFSCORRUPTED, ino, block, function, line);
817 
818 	if (ext4_error_ratelimit(sb)) {
819 		va_start(args, fmt);
820 		vaf.fmt = fmt;
821 		vaf.va = &args;
822 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
823 		       sb->s_id, function, line, grp);
824 		if (ino)
825 			printk(KERN_CONT "inode %lu: ", ino);
826 		if (block)
827 			printk(KERN_CONT "block %llu:",
828 			       (unsigned long long) block);
829 		printk(KERN_CONT "%pV\n", &vaf);
830 		va_end(args);
831 	}
832 
833 	if (test_opt(sb, WARN_ON_ERROR))
834 		WARN_ON_ONCE(1);
835 
836 	if (test_opt(sb, ERRORS_CONT)) {
837 		ext4_commit_super(sb, 0);
838 		return;
839 	}
840 
841 	ext4_unlock_group(sb, grp);
842 	ext4_commit_super(sb, 1);
843 	ext4_handle_error(sb);
844 	/*
845 	 * We only get here in the ERRORS_RO case; relocking the group
846 	 * may be dangerous, but nothing bad will happen since the
847 	 * filesystem will have already been marked read/only and the
848 	 * journal has been aborted.  We return 1 as a hint to callers
849 	 * who might what to use the return value from
850 	 * ext4_grp_locked_error() to distinguish between the
851 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
852 	 * aggressively from the ext4 function in question, with a
853 	 * more appropriate error code.
854 	 */
855 	ext4_lock_group(sb, grp);
856 	return;
857 }
858 
859 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
860 				     ext4_group_t group,
861 				     unsigned int flags)
862 {
863 	struct ext4_sb_info *sbi = EXT4_SB(sb);
864 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
865 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
866 	int ret;
867 
868 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
869 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
870 					    &grp->bb_state);
871 		if (!ret)
872 			percpu_counter_sub(&sbi->s_freeclusters_counter,
873 					   grp->bb_free);
874 	}
875 
876 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
877 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
878 					    &grp->bb_state);
879 		if (!ret && gdp) {
880 			int count;
881 
882 			count = ext4_free_inodes_count(sb, gdp);
883 			percpu_counter_sub(&sbi->s_freeinodes_counter,
884 					   count);
885 		}
886 	}
887 }
888 
889 void ext4_update_dynamic_rev(struct super_block *sb)
890 {
891 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
892 
893 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
894 		return;
895 
896 	ext4_warning(sb,
897 		     "updating to rev %d because of new feature flag, "
898 		     "running e2fsck is recommended",
899 		     EXT4_DYNAMIC_REV);
900 
901 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
902 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
903 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
904 	/* leave es->s_feature_*compat flags alone */
905 	/* es->s_uuid will be set by e2fsck if empty */
906 
907 	/*
908 	 * The rest of the superblock fields should be zero, and if not it
909 	 * means they are likely already in use, so leave them alone.  We
910 	 * can leave it up to e2fsck to clean up any inconsistencies there.
911 	 */
912 }
913 
914 /*
915  * Open the external journal device
916  */
917 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
918 {
919 	struct block_device *bdev;
920 
921 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
922 	if (IS_ERR(bdev))
923 		goto fail;
924 	return bdev;
925 
926 fail:
927 	ext4_msg(sb, KERN_ERR,
928 		 "failed to open journal device unknown-block(%u,%u) %ld",
929 		 MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
930 	return NULL;
931 }
932 
933 /*
934  * Release the journal device
935  */
936 static void ext4_blkdev_put(struct block_device *bdev)
937 {
938 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
939 }
940 
941 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
942 {
943 	struct block_device *bdev;
944 	bdev = sbi->journal_bdev;
945 	if (bdev) {
946 		ext4_blkdev_put(bdev);
947 		sbi->journal_bdev = NULL;
948 	}
949 }
950 
951 static inline struct inode *orphan_list_entry(struct list_head *l)
952 {
953 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
954 }
955 
956 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
957 {
958 	struct list_head *l;
959 
960 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
961 		 le32_to_cpu(sbi->s_es->s_last_orphan));
962 
963 	printk(KERN_ERR "sb_info orphan list:\n");
964 	list_for_each(l, &sbi->s_orphan) {
965 		struct inode *inode = orphan_list_entry(l);
966 		printk(KERN_ERR "  "
967 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
968 		       inode->i_sb->s_id, inode->i_ino, inode,
969 		       inode->i_mode, inode->i_nlink,
970 		       NEXT_ORPHAN(inode));
971 	}
972 }
973 
974 #ifdef CONFIG_QUOTA
975 static int ext4_quota_off(struct super_block *sb, int type);
976 
977 static inline void ext4_quota_off_umount(struct super_block *sb)
978 {
979 	int type;
980 
981 	/* Use our quota_off function to clear inode flags etc. */
982 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
983 		ext4_quota_off(sb, type);
984 }
985 
986 /*
987  * This is a helper function which is used in the mount/remount
988  * codepaths (which holds s_umount) to fetch the quota file name.
989  */
990 static inline char *get_qf_name(struct super_block *sb,
991 				struct ext4_sb_info *sbi,
992 				int type)
993 {
994 	return rcu_dereference_protected(sbi->s_qf_names[type],
995 					 lockdep_is_held(&sb->s_umount));
996 }
997 #else
998 static inline void ext4_quota_off_umount(struct super_block *sb)
999 {
1000 }
1001 #endif
1002 
1003 static void ext4_put_super(struct super_block *sb)
1004 {
1005 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1006 	struct ext4_super_block *es = sbi->s_es;
1007 	struct buffer_head **group_desc;
1008 	struct flex_groups **flex_groups;
1009 	int aborted = 0;
1010 	int i, err;
1011 
1012 	ext4_unregister_li_request(sb);
1013 	ext4_quota_off_umount(sb);
1014 
1015 	destroy_workqueue(sbi->rsv_conversion_wq);
1016 
1017 	/*
1018 	 * Unregister sysfs before destroying jbd2 journal.
1019 	 * Since we could still access attr_journal_task attribute via sysfs
1020 	 * path which could have sbi->s_journal->j_task as NULL
1021 	 */
1022 	ext4_unregister_sysfs(sb);
1023 
1024 	if (sbi->s_journal) {
1025 		aborted = is_journal_aborted(sbi->s_journal);
1026 		err = jbd2_journal_destroy(sbi->s_journal);
1027 		sbi->s_journal = NULL;
1028 		if ((err < 0) && !aborted) {
1029 			ext4_abort(sb, -err, "Couldn't clean up the journal");
1030 		}
1031 	}
1032 
1033 	ext4_es_unregister_shrinker(sbi);
1034 	del_timer_sync(&sbi->s_err_report);
1035 	ext4_release_system_zone(sb);
1036 	ext4_mb_release(sb);
1037 	ext4_ext_release(sb);
1038 
1039 	if (!sb_rdonly(sb) && !aborted) {
1040 		ext4_clear_feature_journal_needs_recovery(sb);
1041 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1042 	}
1043 	if (!sb_rdonly(sb))
1044 		ext4_commit_super(sb, 1);
1045 
1046 	rcu_read_lock();
1047 	group_desc = rcu_dereference(sbi->s_group_desc);
1048 	for (i = 0; i < sbi->s_gdb_count; i++)
1049 		brelse(group_desc[i]);
1050 	kvfree(group_desc);
1051 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1052 	if (flex_groups) {
1053 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1054 			kvfree(flex_groups[i]);
1055 		kvfree(flex_groups);
1056 	}
1057 	rcu_read_unlock();
1058 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1059 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1060 	percpu_counter_destroy(&sbi->s_dirs_counter);
1061 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1062 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1063 #ifdef CONFIG_QUOTA
1064 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1065 		kfree(get_qf_name(sb, sbi, i));
1066 #endif
1067 
1068 	/* Debugging code just in case the in-memory inode orphan list
1069 	 * isn't empty.  The on-disk one can be non-empty if we've
1070 	 * detected an error and taken the fs readonly, but the
1071 	 * in-memory list had better be clean by this point. */
1072 	if (!list_empty(&sbi->s_orphan))
1073 		dump_orphan_list(sb, sbi);
1074 	J_ASSERT(list_empty(&sbi->s_orphan));
1075 
1076 	sync_blockdev(sb->s_bdev);
1077 	invalidate_bdev(sb->s_bdev);
1078 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1079 		/*
1080 		 * Invalidate the journal device's buffers.  We don't want them
1081 		 * floating about in memory - the physical journal device may
1082 		 * hotswapped, and it breaks the `ro-after' testing code.
1083 		 */
1084 		sync_blockdev(sbi->journal_bdev);
1085 		invalidate_bdev(sbi->journal_bdev);
1086 		ext4_blkdev_remove(sbi);
1087 	}
1088 
1089 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1090 	sbi->s_ea_inode_cache = NULL;
1091 
1092 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1093 	sbi->s_ea_block_cache = NULL;
1094 
1095 	if (sbi->s_mmp_tsk)
1096 		kthread_stop(sbi->s_mmp_tsk);
1097 	brelse(sbi->s_sbh);
1098 	sb->s_fs_info = NULL;
1099 	/*
1100 	 * Now that we are completely done shutting down the
1101 	 * superblock, we need to actually destroy the kobject.
1102 	 */
1103 	kobject_put(&sbi->s_kobj);
1104 	wait_for_completion(&sbi->s_kobj_unregister);
1105 	if (sbi->s_chksum_driver)
1106 		crypto_free_shash(sbi->s_chksum_driver);
1107 	kfree(sbi->s_blockgroup_lock);
1108 	fs_put_dax(sbi->s_daxdev);
1109 #ifdef CONFIG_UNICODE
1110 	utf8_unload(sbi->s_encoding);
1111 #endif
1112 	kfree(sbi);
1113 }
1114 
1115 static struct kmem_cache *ext4_inode_cachep;
1116 
1117 /*
1118  * Called inside transaction, so use GFP_NOFS
1119  */
1120 static struct inode *ext4_alloc_inode(struct super_block *sb)
1121 {
1122 	struct ext4_inode_info *ei;
1123 
1124 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1125 	if (!ei)
1126 		return NULL;
1127 
1128 	inode_set_iversion(&ei->vfs_inode, 1);
1129 	spin_lock_init(&ei->i_raw_lock);
1130 	INIT_LIST_HEAD(&ei->i_prealloc_list);
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);
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 						wait & ~__GFP_DIRECT_RECLAIM);
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 	res = ext4_convert_inline_data(inode);
1327 	if (res)
1328 		return res;
1329 
1330 	/*
1331 	 * If a journal handle was specified, then the encryption context is
1332 	 * being set on a new inode via inheritance and is part of a larger
1333 	 * transaction to create the inode.  Otherwise the encryption context is
1334 	 * being set on an existing inode in its own transaction.  Only in the
1335 	 * latter case should the "retry on ENOSPC" logic be used.
1336 	 */
1337 
1338 	if (handle) {
1339 		res = ext4_xattr_set_handle(handle, inode,
1340 					    EXT4_XATTR_INDEX_ENCRYPTION,
1341 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1342 					    ctx, len, 0);
1343 		if (!res) {
1344 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1345 			ext4_clear_inode_state(inode,
1346 					EXT4_STATE_MAY_INLINE_DATA);
1347 			/*
1348 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1349 			 * S_DAX may be disabled
1350 			 */
1351 			ext4_set_inode_flags(inode);
1352 		}
1353 		return res;
1354 	}
1355 
1356 	res = dquot_initialize(inode);
1357 	if (res)
1358 		return res;
1359 retry:
1360 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1361 				     &credits);
1362 	if (res)
1363 		return res;
1364 
1365 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1366 	if (IS_ERR(handle))
1367 		return PTR_ERR(handle);
1368 
1369 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1370 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1371 				    ctx, len, 0);
1372 	if (!res) {
1373 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1374 		/*
1375 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1376 		 * S_DAX may be disabled
1377 		 */
1378 		ext4_set_inode_flags(inode);
1379 		res = ext4_mark_inode_dirty(handle, inode);
1380 		if (res)
1381 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1382 	}
1383 	res2 = ext4_journal_stop(handle);
1384 
1385 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1386 		goto retry;
1387 	if (!res)
1388 		res = res2;
1389 	return res;
1390 }
1391 
1392 static bool ext4_dummy_context(struct inode *inode)
1393 {
1394 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1395 }
1396 
1397 static bool ext4_has_stable_inodes(struct super_block *sb)
1398 {
1399 	return ext4_has_feature_stable_inodes(sb);
1400 }
1401 
1402 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1403 				       int *ino_bits_ret, int *lblk_bits_ret)
1404 {
1405 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1406 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1407 }
1408 
1409 static const struct fscrypt_operations ext4_cryptops = {
1410 	.key_prefix		= "ext4:",
1411 	.get_context		= ext4_get_context,
1412 	.set_context		= ext4_set_context,
1413 	.dummy_context		= ext4_dummy_context,
1414 	.empty_dir		= ext4_empty_dir,
1415 	.max_namelen		= EXT4_NAME_LEN,
1416 	.has_stable_inodes	= ext4_has_stable_inodes,
1417 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1418 };
1419 #endif
1420 
1421 #ifdef CONFIG_QUOTA
1422 static const char * const quotatypes[] = INITQFNAMES;
1423 #define QTYPE2NAME(t) (quotatypes[t])
1424 
1425 static int ext4_write_dquot(struct dquot *dquot);
1426 static int ext4_acquire_dquot(struct dquot *dquot);
1427 static int ext4_release_dquot(struct dquot *dquot);
1428 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1429 static int ext4_write_info(struct super_block *sb, int type);
1430 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1431 			 const struct path *path);
1432 static int ext4_quota_on_mount(struct super_block *sb, int type);
1433 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1434 			       size_t len, loff_t off);
1435 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1436 				const char *data, size_t len, loff_t off);
1437 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1438 			     unsigned int flags);
1439 static int ext4_enable_quotas(struct super_block *sb);
1440 
1441 static struct dquot **ext4_get_dquots(struct inode *inode)
1442 {
1443 	return EXT4_I(inode)->i_dquot;
1444 }
1445 
1446 static const struct dquot_operations ext4_quota_operations = {
1447 	.get_reserved_space	= ext4_get_reserved_space,
1448 	.write_dquot		= ext4_write_dquot,
1449 	.acquire_dquot		= ext4_acquire_dquot,
1450 	.release_dquot		= ext4_release_dquot,
1451 	.mark_dirty		= ext4_mark_dquot_dirty,
1452 	.write_info		= ext4_write_info,
1453 	.alloc_dquot		= dquot_alloc,
1454 	.destroy_dquot		= dquot_destroy,
1455 	.get_projid		= ext4_get_projid,
1456 	.get_inode_usage	= ext4_get_inode_usage,
1457 	.get_next_id		= dquot_get_next_id,
1458 };
1459 
1460 static const struct quotactl_ops ext4_qctl_operations = {
1461 	.quota_on	= ext4_quota_on,
1462 	.quota_off	= ext4_quota_off,
1463 	.quota_sync	= dquot_quota_sync,
1464 	.get_state	= dquot_get_state,
1465 	.set_info	= dquot_set_dqinfo,
1466 	.get_dqblk	= dquot_get_dqblk,
1467 	.set_dqblk	= dquot_set_dqblk,
1468 	.get_nextdqblk	= dquot_get_next_dqblk,
1469 };
1470 #endif
1471 
1472 static const struct super_operations ext4_sops = {
1473 	.alloc_inode	= ext4_alloc_inode,
1474 	.free_inode	= ext4_free_in_core_inode,
1475 	.destroy_inode	= ext4_destroy_inode,
1476 	.write_inode	= ext4_write_inode,
1477 	.dirty_inode	= ext4_dirty_inode,
1478 	.drop_inode	= ext4_drop_inode,
1479 	.evict_inode	= ext4_evict_inode,
1480 	.put_super	= ext4_put_super,
1481 	.sync_fs	= ext4_sync_fs,
1482 	.freeze_fs	= ext4_freeze,
1483 	.unfreeze_fs	= ext4_unfreeze,
1484 	.statfs		= ext4_statfs,
1485 	.remount_fs	= ext4_remount,
1486 	.show_options	= ext4_show_options,
1487 #ifdef CONFIG_QUOTA
1488 	.quota_read	= ext4_quota_read,
1489 	.quota_write	= ext4_quota_write,
1490 	.get_dquots	= ext4_get_dquots,
1491 #endif
1492 	.bdev_try_to_free_page = bdev_try_to_free_page,
1493 };
1494 
1495 static const struct export_operations ext4_export_ops = {
1496 	.fh_to_dentry = ext4_fh_to_dentry,
1497 	.fh_to_parent = ext4_fh_to_parent,
1498 	.get_parent = ext4_get_parent,
1499 	.commit_metadata = ext4_nfs_commit_metadata,
1500 };
1501 
1502 enum {
1503 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1504 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1505 	Opt_nouid32, Opt_debug, Opt_removed,
1506 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1507 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1508 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1509 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1510 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1511 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1512 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1513 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1514 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1515 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1516 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1517 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1518 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1519 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1520 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1521 	Opt_dioread_nolock, Opt_dioread_lock,
1522 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1523 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1524 };
1525 
1526 static const match_table_t tokens = {
1527 	{Opt_bsd_df, "bsddf"},
1528 	{Opt_minix_df, "minixdf"},
1529 	{Opt_grpid, "grpid"},
1530 	{Opt_grpid, "bsdgroups"},
1531 	{Opt_nogrpid, "nogrpid"},
1532 	{Opt_nogrpid, "sysvgroups"},
1533 	{Opt_resgid, "resgid=%u"},
1534 	{Opt_resuid, "resuid=%u"},
1535 	{Opt_sb, "sb=%u"},
1536 	{Opt_err_cont, "errors=continue"},
1537 	{Opt_err_panic, "errors=panic"},
1538 	{Opt_err_ro, "errors=remount-ro"},
1539 	{Opt_nouid32, "nouid32"},
1540 	{Opt_debug, "debug"},
1541 	{Opt_removed, "oldalloc"},
1542 	{Opt_removed, "orlov"},
1543 	{Opt_user_xattr, "user_xattr"},
1544 	{Opt_nouser_xattr, "nouser_xattr"},
1545 	{Opt_acl, "acl"},
1546 	{Opt_noacl, "noacl"},
1547 	{Opt_noload, "norecovery"},
1548 	{Opt_noload, "noload"},
1549 	{Opt_removed, "nobh"},
1550 	{Opt_removed, "bh"},
1551 	{Opt_commit, "commit=%u"},
1552 	{Opt_min_batch_time, "min_batch_time=%u"},
1553 	{Opt_max_batch_time, "max_batch_time=%u"},
1554 	{Opt_journal_dev, "journal_dev=%u"},
1555 	{Opt_journal_path, "journal_path=%s"},
1556 	{Opt_journal_checksum, "journal_checksum"},
1557 	{Opt_nojournal_checksum, "nojournal_checksum"},
1558 	{Opt_journal_async_commit, "journal_async_commit"},
1559 	{Opt_abort, "abort"},
1560 	{Opt_data_journal, "data=journal"},
1561 	{Opt_data_ordered, "data=ordered"},
1562 	{Opt_data_writeback, "data=writeback"},
1563 	{Opt_data_err_abort, "data_err=abort"},
1564 	{Opt_data_err_ignore, "data_err=ignore"},
1565 	{Opt_offusrjquota, "usrjquota="},
1566 	{Opt_usrjquota, "usrjquota=%s"},
1567 	{Opt_offgrpjquota, "grpjquota="},
1568 	{Opt_grpjquota, "grpjquota=%s"},
1569 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1570 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1571 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1572 	{Opt_grpquota, "grpquota"},
1573 	{Opt_noquota, "noquota"},
1574 	{Opt_quota, "quota"},
1575 	{Opt_usrquota, "usrquota"},
1576 	{Opt_prjquota, "prjquota"},
1577 	{Opt_barrier, "barrier=%u"},
1578 	{Opt_barrier, "barrier"},
1579 	{Opt_nobarrier, "nobarrier"},
1580 	{Opt_i_version, "i_version"},
1581 	{Opt_dax, "dax"},
1582 	{Opt_stripe, "stripe=%u"},
1583 	{Opt_delalloc, "delalloc"},
1584 	{Opt_warn_on_error, "warn_on_error"},
1585 	{Opt_nowarn_on_error, "nowarn_on_error"},
1586 	{Opt_lazytime, "lazytime"},
1587 	{Opt_nolazytime, "nolazytime"},
1588 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1589 	{Opt_nodelalloc, "nodelalloc"},
1590 	{Opt_removed, "mblk_io_submit"},
1591 	{Opt_removed, "nomblk_io_submit"},
1592 	{Opt_block_validity, "block_validity"},
1593 	{Opt_noblock_validity, "noblock_validity"},
1594 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1595 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1596 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1597 	{Opt_auto_da_alloc, "auto_da_alloc"},
1598 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1599 	{Opt_dioread_nolock, "dioread_nolock"},
1600 	{Opt_dioread_lock, "nodioread_nolock"},
1601 	{Opt_dioread_lock, "dioread_lock"},
1602 	{Opt_discard, "discard"},
1603 	{Opt_nodiscard, "nodiscard"},
1604 	{Opt_init_itable, "init_itable=%u"},
1605 	{Opt_init_itable, "init_itable"},
1606 	{Opt_noinit_itable, "noinit_itable"},
1607 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1608 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1609 	{Opt_nombcache, "nombcache"},
1610 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1611 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1612 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1613 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1614 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1615 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1616 	{Opt_err, NULL},
1617 };
1618 
1619 static ext4_fsblk_t get_sb_block(void **data)
1620 {
1621 	ext4_fsblk_t	sb_block;
1622 	char		*options = (char *) *data;
1623 
1624 	if (!options || strncmp(options, "sb=", 3) != 0)
1625 		return 1;	/* Default location */
1626 
1627 	options += 3;
1628 	/* TODO: use simple_strtoll with >32bit ext4 */
1629 	sb_block = simple_strtoul(options, &options, 0);
1630 	if (*options && *options != ',') {
1631 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1632 		       (char *) *data);
1633 		return 1;
1634 	}
1635 	if (*options == ',')
1636 		options++;
1637 	*data = (void *) options;
1638 
1639 	return sb_block;
1640 }
1641 
1642 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1643 static const char deprecated_msg[] =
1644 	"Mount option \"%s\" will be removed by %s\n"
1645 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1646 
1647 #ifdef CONFIG_QUOTA
1648 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1649 {
1650 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1651 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1652 	int ret = -1;
1653 
1654 	if (sb_any_quota_loaded(sb) && !old_qname) {
1655 		ext4_msg(sb, KERN_ERR,
1656 			"Cannot change journaled "
1657 			"quota options when quota turned on");
1658 		return -1;
1659 	}
1660 	if (ext4_has_feature_quota(sb)) {
1661 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1662 			 "ignored when QUOTA feature is enabled");
1663 		return 1;
1664 	}
1665 	qname = match_strdup(args);
1666 	if (!qname) {
1667 		ext4_msg(sb, KERN_ERR,
1668 			"Not enough memory for storing quotafile name");
1669 		return -1;
1670 	}
1671 	if (old_qname) {
1672 		if (strcmp(old_qname, qname) == 0)
1673 			ret = 1;
1674 		else
1675 			ext4_msg(sb, KERN_ERR,
1676 				 "%s quota file already specified",
1677 				 QTYPE2NAME(qtype));
1678 		goto errout;
1679 	}
1680 	if (strchr(qname, '/')) {
1681 		ext4_msg(sb, KERN_ERR,
1682 			"quotafile must be on filesystem root");
1683 		goto errout;
1684 	}
1685 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1686 	set_opt(sb, QUOTA);
1687 	return 1;
1688 errout:
1689 	kfree(qname);
1690 	return ret;
1691 }
1692 
1693 static int clear_qf_name(struct super_block *sb, int qtype)
1694 {
1695 
1696 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1697 	char *old_qname = get_qf_name(sb, sbi, qtype);
1698 
1699 	if (sb_any_quota_loaded(sb) && old_qname) {
1700 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1701 			" when quota turned on");
1702 		return -1;
1703 	}
1704 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1705 	synchronize_rcu();
1706 	kfree(old_qname);
1707 	return 1;
1708 }
1709 #endif
1710 
1711 #define MOPT_SET	0x0001
1712 #define MOPT_CLEAR	0x0002
1713 #define MOPT_NOSUPPORT	0x0004
1714 #define MOPT_EXPLICIT	0x0008
1715 #define MOPT_CLEAR_ERR	0x0010
1716 #define MOPT_GTE0	0x0020
1717 #ifdef CONFIG_QUOTA
1718 #define MOPT_Q		0
1719 #define MOPT_QFMT	0x0040
1720 #else
1721 #define MOPT_Q		MOPT_NOSUPPORT
1722 #define MOPT_QFMT	MOPT_NOSUPPORT
1723 #endif
1724 #define MOPT_DATAJ	0x0080
1725 #define MOPT_NO_EXT2	0x0100
1726 #define MOPT_NO_EXT3	0x0200
1727 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1728 #define MOPT_STRING	0x0400
1729 
1730 static const struct mount_opts {
1731 	int	token;
1732 	int	mount_opt;
1733 	int	flags;
1734 } ext4_mount_opts[] = {
1735 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1736 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1737 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1738 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1739 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1740 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1741 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1742 	 MOPT_EXT4_ONLY | MOPT_SET},
1743 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1744 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1745 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1746 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1747 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1748 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1749 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1750 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1751 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1752 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1753 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1754 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1755 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1756 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1757 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1758 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1759 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1760 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1761 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1762 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1763 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1764 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1765 	 MOPT_NO_EXT2},
1766 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1767 	 MOPT_NO_EXT2},
1768 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1769 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1770 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1771 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1772 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1773 	{Opt_commit, 0, MOPT_GTE0},
1774 	{Opt_max_batch_time, 0, MOPT_GTE0},
1775 	{Opt_min_batch_time, 0, MOPT_GTE0},
1776 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1777 	{Opt_init_itable, 0, MOPT_GTE0},
1778 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1779 	{Opt_stripe, 0, MOPT_GTE0},
1780 	{Opt_resuid, 0, MOPT_GTE0},
1781 	{Opt_resgid, 0, MOPT_GTE0},
1782 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1783 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1784 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1785 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1786 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1787 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1788 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1789 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1790 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1791 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1792 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1793 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1794 #else
1795 	{Opt_acl, 0, MOPT_NOSUPPORT},
1796 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1797 #endif
1798 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1799 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1800 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1801 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1802 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1803 							MOPT_SET | MOPT_Q},
1804 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1805 							MOPT_SET | MOPT_Q},
1806 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1807 							MOPT_SET | MOPT_Q},
1808 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1809 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1810 							MOPT_CLEAR | MOPT_Q},
1811 	{Opt_usrjquota, 0, MOPT_Q},
1812 	{Opt_grpjquota, 0, MOPT_Q},
1813 	{Opt_offusrjquota, 0, MOPT_Q},
1814 	{Opt_offgrpjquota, 0, MOPT_Q},
1815 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1816 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1817 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1818 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1819 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1820 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1821 	{Opt_err, 0, 0}
1822 };
1823 
1824 #ifdef CONFIG_UNICODE
1825 static const struct ext4_sb_encodings {
1826 	__u16 magic;
1827 	char *name;
1828 	char *version;
1829 } ext4_sb_encoding_map[] = {
1830 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1831 };
1832 
1833 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1834 				 const struct ext4_sb_encodings **encoding,
1835 				 __u16 *flags)
1836 {
1837 	__u16 magic = le16_to_cpu(es->s_encoding);
1838 	int i;
1839 
1840 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1841 		if (magic == ext4_sb_encoding_map[i].magic)
1842 			break;
1843 
1844 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1845 		return -EINVAL;
1846 
1847 	*encoding = &ext4_sb_encoding_map[i];
1848 	*flags = le16_to_cpu(es->s_encoding_flags);
1849 
1850 	return 0;
1851 }
1852 #endif
1853 
1854 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1855 			    substring_t *args, unsigned long *journal_devnum,
1856 			    unsigned int *journal_ioprio, int is_remount)
1857 {
1858 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1859 	const struct mount_opts *m;
1860 	kuid_t uid;
1861 	kgid_t gid;
1862 	int arg = 0;
1863 
1864 #ifdef CONFIG_QUOTA
1865 	if (token == Opt_usrjquota)
1866 		return set_qf_name(sb, USRQUOTA, &args[0]);
1867 	else if (token == Opt_grpjquota)
1868 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1869 	else if (token == Opt_offusrjquota)
1870 		return clear_qf_name(sb, USRQUOTA);
1871 	else if (token == Opt_offgrpjquota)
1872 		return clear_qf_name(sb, GRPQUOTA);
1873 #endif
1874 	switch (token) {
1875 	case Opt_noacl:
1876 	case Opt_nouser_xattr:
1877 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1878 		break;
1879 	case Opt_sb:
1880 		return 1;	/* handled by get_sb_block() */
1881 	case Opt_removed:
1882 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1883 		return 1;
1884 	case Opt_abort:
1885 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1886 		return 1;
1887 	case Opt_i_version:
1888 		sb->s_flags |= SB_I_VERSION;
1889 		return 1;
1890 	case Opt_lazytime:
1891 		sb->s_flags |= SB_LAZYTIME;
1892 		return 1;
1893 	case Opt_nolazytime:
1894 		sb->s_flags &= ~SB_LAZYTIME;
1895 		return 1;
1896 	}
1897 
1898 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1899 		if (token == m->token)
1900 			break;
1901 
1902 	if (m->token == Opt_err) {
1903 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1904 			 "or missing value", opt);
1905 		return -1;
1906 	}
1907 
1908 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1909 		ext4_msg(sb, KERN_ERR,
1910 			 "Mount option \"%s\" incompatible with ext2", opt);
1911 		return -1;
1912 	}
1913 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1914 		ext4_msg(sb, KERN_ERR,
1915 			 "Mount option \"%s\" incompatible with ext3", opt);
1916 		return -1;
1917 	}
1918 
1919 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1920 		return -1;
1921 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1922 		return -1;
1923 	if (m->flags & MOPT_EXPLICIT) {
1924 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1925 			set_opt2(sb, EXPLICIT_DELALLOC);
1926 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1927 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1928 		} else
1929 			return -1;
1930 	}
1931 	if (m->flags & MOPT_CLEAR_ERR)
1932 		clear_opt(sb, ERRORS_MASK);
1933 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1934 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1935 			 "options when quota turned on");
1936 		return -1;
1937 	}
1938 
1939 	if (m->flags & MOPT_NOSUPPORT) {
1940 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1941 	} else if (token == Opt_commit) {
1942 		if (arg == 0)
1943 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1944 		else if (arg > INT_MAX / HZ) {
1945 			ext4_msg(sb, KERN_ERR,
1946 				 "Invalid commit interval %d, "
1947 				 "must be smaller than %d",
1948 				 arg, INT_MAX / HZ);
1949 			return -1;
1950 		}
1951 		sbi->s_commit_interval = HZ * arg;
1952 	} else if (token == Opt_debug_want_extra_isize) {
1953 		if ((arg & 1) ||
1954 		    (arg < 4) ||
1955 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
1956 			ext4_msg(sb, KERN_ERR,
1957 				 "Invalid want_extra_isize %d", arg);
1958 			return -1;
1959 		}
1960 		sbi->s_want_extra_isize = arg;
1961 	} else if (token == Opt_max_batch_time) {
1962 		sbi->s_max_batch_time = arg;
1963 	} else if (token == Opt_min_batch_time) {
1964 		sbi->s_min_batch_time = arg;
1965 	} else if (token == Opt_inode_readahead_blks) {
1966 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1967 			ext4_msg(sb, KERN_ERR,
1968 				 "EXT4-fs: inode_readahead_blks must be "
1969 				 "0 or a power of 2 smaller than 2^31");
1970 			return -1;
1971 		}
1972 		sbi->s_inode_readahead_blks = arg;
1973 	} else if (token == Opt_init_itable) {
1974 		set_opt(sb, INIT_INODE_TABLE);
1975 		if (!args->from)
1976 			arg = EXT4_DEF_LI_WAIT_MULT;
1977 		sbi->s_li_wait_mult = arg;
1978 	} else if (token == Opt_max_dir_size_kb) {
1979 		sbi->s_max_dir_size_kb = arg;
1980 	} else if (token == Opt_stripe) {
1981 		sbi->s_stripe = arg;
1982 	} else if (token == Opt_resuid) {
1983 		uid = make_kuid(current_user_ns(), arg);
1984 		if (!uid_valid(uid)) {
1985 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1986 			return -1;
1987 		}
1988 		sbi->s_resuid = uid;
1989 	} else if (token == Opt_resgid) {
1990 		gid = make_kgid(current_user_ns(), arg);
1991 		if (!gid_valid(gid)) {
1992 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1993 			return -1;
1994 		}
1995 		sbi->s_resgid = gid;
1996 	} else if (token == Opt_journal_dev) {
1997 		if (is_remount) {
1998 			ext4_msg(sb, KERN_ERR,
1999 				 "Cannot specify journal on remount");
2000 			return -1;
2001 		}
2002 		*journal_devnum = arg;
2003 	} else if (token == Opt_journal_path) {
2004 		char *journal_path;
2005 		struct inode *journal_inode;
2006 		struct path path;
2007 		int error;
2008 
2009 		if (is_remount) {
2010 			ext4_msg(sb, KERN_ERR,
2011 				 "Cannot specify journal on remount");
2012 			return -1;
2013 		}
2014 		journal_path = match_strdup(&args[0]);
2015 		if (!journal_path) {
2016 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2017 				"journal device string");
2018 			return -1;
2019 		}
2020 
2021 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2022 		if (error) {
2023 			ext4_msg(sb, KERN_ERR, "error: could not find "
2024 				"journal device path: error %d", error);
2025 			kfree(journal_path);
2026 			return -1;
2027 		}
2028 
2029 		journal_inode = d_inode(path.dentry);
2030 		if (!S_ISBLK(journal_inode->i_mode)) {
2031 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2032 				"is not a block device", journal_path);
2033 			path_put(&path);
2034 			kfree(journal_path);
2035 			return -1;
2036 		}
2037 
2038 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2039 		path_put(&path);
2040 		kfree(journal_path);
2041 	} else if (token == Opt_journal_ioprio) {
2042 		if (arg > 7) {
2043 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2044 				 " (must be 0-7)");
2045 			return -1;
2046 		}
2047 		*journal_ioprio =
2048 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2049 	} else if (token == Opt_test_dummy_encryption) {
2050 #ifdef CONFIG_FS_ENCRYPTION
2051 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
2052 		ext4_msg(sb, KERN_WARNING,
2053 			 "Test dummy encryption mode enabled");
2054 #else
2055 		ext4_msg(sb, KERN_WARNING,
2056 			 "Test dummy encryption mount option ignored");
2057 #endif
2058 	} else if (m->flags & MOPT_DATAJ) {
2059 		if (is_remount) {
2060 			if (!sbi->s_journal)
2061 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2062 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2063 				ext4_msg(sb, KERN_ERR,
2064 					 "Cannot change data mode on remount");
2065 				return -1;
2066 			}
2067 		} else {
2068 			clear_opt(sb, DATA_FLAGS);
2069 			sbi->s_mount_opt |= m->mount_opt;
2070 		}
2071 #ifdef CONFIG_QUOTA
2072 	} else if (m->flags & MOPT_QFMT) {
2073 		if (sb_any_quota_loaded(sb) &&
2074 		    sbi->s_jquota_fmt != m->mount_opt) {
2075 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2076 				 "quota options when quota turned on");
2077 			return -1;
2078 		}
2079 		if (ext4_has_feature_quota(sb)) {
2080 			ext4_msg(sb, KERN_INFO,
2081 				 "Quota format mount options ignored "
2082 				 "when QUOTA feature is enabled");
2083 			return 1;
2084 		}
2085 		sbi->s_jquota_fmt = m->mount_opt;
2086 #endif
2087 	} else if (token == Opt_dax) {
2088 #ifdef CONFIG_FS_DAX
2089 		ext4_msg(sb, KERN_WARNING,
2090 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2091 		sbi->s_mount_opt |= m->mount_opt;
2092 #else
2093 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2094 		return -1;
2095 #endif
2096 	} else if (token == Opt_data_err_abort) {
2097 		sbi->s_mount_opt |= m->mount_opt;
2098 	} else if (token == Opt_data_err_ignore) {
2099 		sbi->s_mount_opt &= ~m->mount_opt;
2100 	} else {
2101 		if (!args->from)
2102 			arg = 1;
2103 		if (m->flags & MOPT_CLEAR)
2104 			arg = !arg;
2105 		else if (unlikely(!(m->flags & MOPT_SET))) {
2106 			ext4_msg(sb, KERN_WARNING,
2107 				 "buggy handling of option %s", opt);
2108 			WARN_ON(1);
2109 			return -1;
2110 		}
2111 		if (arg != 0)
2112 			sbi->s_mount_opt |= m->mount_opt;
2113 		else
2114 			sbi->s_mount_opt &= ~m->mount_opt;
2115 	}
2116 	return 1;
2117 }
2118 
2119 static int parse_options(char *options, struct super_block *sb,
2120 			 unsigned long *journal_devnum,
2121 			 unsigned int *journal_ioprio,
2122 			 int is_remount)
2123 {
2124 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2125 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2126 	substring_t args[MAX_OPT_ARGS];
2127 	int token;
2128 
2129 	if (!options)
2130 		return 1;
2131 
2132 	while ((p = strsep(&options, ",")) != NULL) {
2133 		if (!*p)
2134 			continue;
2135 		/*
2136 		 * Initialize args struct so we know whether arg was
2137 		 * found; some options take optional arguments.
2138 		 */
2139 		args[0].to = args[0].from = NULL;
2140 		token = match_token(p, tokens, args);
2141 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2142 				     journal_ioprio, is_remount) < 0)
2143 			return 0;
2144 	}
2145 #ifdef CONFIG_QUOTA
2146 	/*
2147 	 * We do the test below only for project quotas. 'usrquota' and
2148 	 * 'grpquota' mount options are allowed even without quota feature
2149 	 * to support legacy quotas in quota files.
2150 	 */
2151 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2152 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2153 			 "Cannot enable project quota enforcement.");
2154 		return 0;
2155 	}
2156 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2157 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2158 	if (usr_qf_name || grp_qf_name) {
2159 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2160 			clear_opt(sb, USRQUOTA);
2161 
2162 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2163 			clear_opt(sb, GRPQUOTA);
2164 
2165 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2166 			ext4_msg(sb, KERN_ERR, "old and new quota "
2167 					"format mixing");
2168 			return 0;
2169 		}
2170 
2171 		if (!sbi->s_jquota_fmt) {
2172 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2173 					"not specified");
2174 			return 0;
2175 		}
2176 	}
2177 #endif
2178 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2179 		int blocksize =
2180 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2181 		if (blocksize < PAGE_SIZE)
2182 			ext4_msg(sb, KERN_WARNING, "Warning: mounting with an "
2183 				 "experimental mount option 'dioread_nolock' "
2184 				 "for blocksize < PAGE_SIZE");
2185 	}
2186 	return 1;
2187 }
2188 
2189 static inline void ext4_show_quota_options(struct seq_file *seq,
2190 					   struct super_block *sb)
2191 {
2192 #if defined(CONFIG_QUOTA)
2193 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2194 	char *usr_qf_name, *grp_qf_name;
2195 
2196 	if (sbi->s_jquota_fmt) {
2197 		char *fmtname = "";
2198 
2199 		switch (sbi->s_jquota_fmt) {
2200 		case QFMT_VFS_OLD:
2201 			fmtname = "vfsold";
2202 			break;
2203 		case QFMT_VFS_V0:
2204 			fmtname = "vfsv0";
2205 			break;
2206 		case QFMT_VFS_V1:
2207 			fmtname = "vfsv1";
2208 			break;
2209 		}
2210 		seq_printf(seq, ",jqfmt=%s", fmtname);
2211 	}
2212 
2213 	rcu_read_lock();
2214 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2215 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2216 	if (usr_qf_name)
2217 		seq_show_option(seq, "usrjquota", usr_qf_name);
2218 	if (grp_qf_name)
2219 		seq_show_option(seq, "grpjquota", grp_qf_name);
2220 	rcu_read_unlock();
2221 #endif
2222 }
2223 
2224 static const char *token2str(int token)
2225 {
2226 	const struct match_token *t;
2227 
2228 	for (t = tokens; t->token != Opt_err; t++)
2229 		if (t->token == token && !strchr(t->pattern, '='))
2230 			break;
2231 	return t->pattern;
2232 }
2233 
2234 /*
2235  * Show an option if
2236  *  - it's set to a non-default value OR
2237  *  - if the per-sb default is different from the global default
2238  */
2239 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2240 			      int nodefs)
2241 {
2242 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2243 	struct ext4_super_block *es = sbi->s_es;
2244 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2245 	const struct mount_opts *m;
2246 	char sep = nodefs ? '\n' : ',';
2247 
2248 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2249 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2250 
2251 	if (sbi->s_sb_block != 1)
2252 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2253 
2254 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2255 		int want_set = m->flags & MOPT_SET;
2256 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2257 		    (m->flags & MOPT_CLEAR_ERR))
2258 			continue;
2259 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2260 			continue; /* skip if same as the default */
2261 		if ((want_set &&
2262 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2263 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2264 			continue; /* select Opt_noFoo vs Opt_Foo */
2265 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2266 	}
2267 
2268 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2269 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2270 		SEQ_OPTS_PRINT("resuid=%u",
2271 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2272 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2273 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2274 		SEQ_OPTS_PRINT("resgid=%u",
2275 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2276 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2277 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2278 		SEQ_OPTS_PUTS("errors=remount-ro");
2279 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2280 		SEQ_OPTS_PUTS("errors=continue");
2281 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2282 		SEQ_OPTS_PUTS("errors=panic");
2283 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2284 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2285 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2286 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2287 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2288 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2289 	if (sb->s_flags & SB_I_VERSION)
2290 		SEQ_OPTS_PUTS("i_version");
2291 	if (nodefs || sbi->s_stripe)
2292 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2293 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2294 			(sbi->s_mount_opt ^ def_mount_opt)) {
2295 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2296 			SEQ_OPTS_PUTS("data=journal");
2297 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2298 			SEQ_OPTS_PUTS("data=ordered");
2299 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2300 			SEQ_OPTS_PUTS("data=writeback");
2301 	}
2302 	if (nodefs ||
2303 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2304 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2305 			       sbi->s_inode_readahead_blks);
2306 
2307 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2308 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2309 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2310 	if (nodefs || sbi->s_max_dir_size_kb)
2311 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2312 	if (test_opt(sb, DATA_ERR_ABORT))
2313 		SEQ_OPTS_PUTS("data_err=abort");
2314 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2315 		SEQ_OPTS_PUTS("test_dummy_encryption");
2316 
2317 	ext4_show_quota_options(seq, sb);
2318 	return 0;
2319 }
2320 
2321 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2322 {
2323 	return _ext4_show_options(seq, root->d_sb, 0);
2324 }
2325 
2326 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2327 {
2328 	struct super_block *sb = seq->private;
2329 	int rc;
2330 
2331 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2332 	rc = _ext4_show_options(seq, sb, 1);
2333 	seq_puts(seq, "\n");
2334 	return rc;
2335 }
2336 
2337 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2338 			    int read_only)
2339 {
2340 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2341 	int err = 0;
2342 
2343 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2344 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2345 			 "forcing read-only mode");
2346 		err = -EROFS;
2347 	}
2348 	if (read_only)
2349 		goto done;
2350 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2351 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2352 			 "running e2fsck is recommended");
2353 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2354 		ext4_msg(sb, KERN_WARNING,
2355 			 "warning: mounting fs with errors, "
2356 			 "running e2fsck is recommended");
2357 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2358 		 le16_to_cpu(es->s_mnt_count) >=
2359 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2360 		ext4_msg(sb, KERN_WARNING,
2361 			 "warning: maximal mount count reached, "
2362 			 "running e2fsck is recommended");
2363 	else if (le32_to_cpu(es->s_checkinterval) &&
2364 		 (ext4_get_tstamp(es, s_lastcheck) +
2365 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2366 		ext4_msg(sb, KERN_WARNING,
2367 			 "warning: checktime reached, "
2368 			 "running e2fsck is recommended");
2369 	if (!sbi->s_journal)
2370 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2371 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2372 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2373 	le16_add_cpu(&es->s_mnt_count, 1);
2374 	ext4_update_tstamp(es, s_mtime);
2375 	if (sbi->s_journal)
2376 		ext4_set_feature_journal_needs_recovery(sb);
2377 
2378 	err = ext4_commit_super(sb, 1);
2379 done:
2380 	if (test_opt(sb, DEBUG))
2381 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2382 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2383 			sb->s_blocksize,
2384 			sbi->s_groups_count,
2385 			EXT4_BLOCKS_PER_GROUP(sb),
2386 			EXT4_INODES_PER_GROUP(sb),
2387 			sbi->s_mount_opt, sbi->s_mount_opt2);
2388 
2389 	cleancache_init_fs(sb);
2390 	return err;
2391 }
2392 
2393 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2394 {
2395 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2396 	struct flex_groups **old_groups, **new_groups;
2397 	int size, i, j;
2398 
2399 	if (!sbi->s_log_groups_per_flex)
2400 		return 0;
2401 
2402 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2403 	if (size <= sbi->s_flex_groups_allocated)
2404 		return 0;
2405 
2406 	new_groups = kvzalloc(roundup_pow_of_two(size *
2407 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2408 	if (!new_groups) {
2409 		ext4_msg(sb, KERN_ERR,
2410 			 "not enough memory for %d flex group pointers", size);
2411 		return -ENOMEM;
2412 	}
2413 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2414 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2415 					 sizeof(struct flex_groups)),
2416 					 GFP_KERNEL);
2417 		if (!new_groups[i]) {
2418 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2419 				kvfree(new_groups[j]);
2420 			kvfree(new_groups);
2421 			ext4_msg(sb, KERN_ERR,
2422 				 "not enough memory for %d flex groups", size);
2423 			return -ENOMEM;
2424 		}
2425 	}
2426 	rcu_read_lock();
2427 	old_groups = rcu_dereference(sbi->s_flex_groups);
2428 	if (old_groups)
2429 		memcpy(new_groups, old_groups,
2430 		       (sbi->s_flex_groups_allocated *
2431 			sizeof(struct flex_groups *)));
2432 	rcu_read_unlock();
2433 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2434 	sbi->s_flex_groups_allocated = size;
2435 	if (old_groups)
2436 		ext4_kvfree_array_rcu(old_groups);
2437 	return 0;
2438 }
2439 
2440 static int ext4_fill_flex_info(struct super_block *sb)
2441 {
2442 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2443 	struct ext4_group_desc *gdp = NULL;
2444 	struct flex_groups *fg;
2445 	ext4_group_t flex_group;
2446 	int i, err;
2447 
2448 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2449 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2450 		sbi->s_log_groups_per_flex = 0;
2451 		return 1;
2452 	}
2453 
2454 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2455 	if (err)
2456 		goto failed;
2457 
2458 	for (i = 0; i < sbi->s_groups_count; i++) {
2459 		gdp = ext4_get_group_desc(sb, i, NULL);
2460 
2461 		flex_group = ext4_flex_group(sbi, i);
2462 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2463 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2464 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2465 			     &fg->free_clusters);
2466 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2467 	}
2468 
2469 	return 1;
2470 failed:
2471 	return 0;
2472 }
2473 
2474 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2475 				   struct ext4_group_desc *gdp)
2476 {
2477 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2478 	__u16 crc = 0;
2479 	__le32 le_group = cpu_to_le32(block_group);
2480 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2481 
2482 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2483 		/* Use new metadata_csum algorithm */
2484 		__u32 csum32;
2485 		__u16 dummy_csum = 0;
2486 
2487 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2488 				     sizeof(le_group));
2489 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2490 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2491 				     sizeof(dummy_csum));
2492 		offset += sizeof(dummy_csum);
2493 		if (offset < sbi->s_desc_size)
2494 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2495 					     sbi->s_desc_size - offset);
2496 
2497 		crc = csum32 & 0xFFFF;
2498 		goto out;
2499 	}
2500 
2501 	/* old crc16 code */
2502 	if (!ext4_has_feature_gdt_csum(sb))
2503 		return 0;
2504 
2505 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2506 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2507 	crc = crc16(crc, (__u8 *)gdp, offset);
2508 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2509 	/* for checksum of struct ext4_group_desc do the rest...*/
2510 	if (ext4_has_feature_64bit(sb) &&
2511 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2512 		crc = crc16(crc, (__u8 *)gdp + offset,
2513 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2514 				offset);
2515 
2516 out:
2517 	return cpu_to_le16(crc);
2518 }
2519 
2520 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2521 				struct ext4_group_desc *gdp)
2522 {
2523 	if (ext4_has_group_desc_csum(sb) &&
2524 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2525 		return 0;
2526 
2527 	return 1;
2528 }
2529 
2530 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2531 			      struct ext4_group_desc *gdp)
2532 {
2533 	if (!ext4_has_group_desc_csum(sb))
2534 		return;
2535 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2536 }
2537 
2538 /* Called at mount-time, super-block is locked */
2539 static int ext4_check_descriptors(struct super_block *sb,
2540 				  ext4_fsblk_t sb_block,
2541 				  ext4_group_t *first_not_zeroed)
2542 {
2543 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2544 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2545 	ext4_fsblk_t last_block;
2546 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2547 	ext4_fsblk_t block_bitmap;
2548 	ext4_fsblk_t inode_bitmap;
2549 	ext4_fsblk_t inode_table;
2550 	int flexbg_flag = 0;
2551 	ext4_group_t i, grp = sbi->s_groups_count;
2552 
2553 	if (ext4_has_feature_flex_bg(sb))
2554 		flexbg_flag = 1;
2555 
2556 	ext4_debug("Checking group descriptors");
2557 
2558 	for (i = 0; i < sbi->s_groups_count; i++) {
2559 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2560 
2561 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2562 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2563 		else
2564 			last_block = first_block +
2565 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2566 
2567 		if ((grp == sbi->s_groups_count) &&
2568 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2569 			grp = i;
2570 
2571 		block_bitmap = ext4_block_bitmap(sb, gdp);
2572 		if (block_bitmap == sb_block) {
2573 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2574 				 "Block bitmap for group %u overlaps "
2575 				 "superblock", i);
2576 			if (!sb_rdonly(sb))
2577 				return 0;
2578 		}
2579 		if (block_bitmap >= sb_block + 1 &&
2580 		    block_bitmap <= last_bg_block) {
2581 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2582 				 "Block bitmap for group %u overlaps "
2583 				 "block group descriptors", i);
2584 			if (!sb_rdonly(sb))
2585 				return 0;
2586 		}
2587 		if (block_bitmap < first_block || block_bitmap > last_block) {
2588 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2589 			       "Block bitmap for group %u not in group "
2590 			       "(block %llu)!", i, block_bitmap);
2591 			return 0;
2592 		}
2593 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2594 		if (inode_bitmap == sb_block) {
2595 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2596 				 "Inode bitmap for group %u overlaps "
2597 				 "superblock", i);
2598 			if (!sb_rdonly(sb))
2599 				return 0;
2600 		}
2601 		if (inode_bitmap >= sb_block + 1 &&
2602 		    inode_bitmap <= last_bg_block) {
2603 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2604 				 "Inode bitmap for group %u overlaps "
2605 				 "block group descriptors", i);
2606 			if (!sb_rdonly(sb))
2607 				return 0;
2608 		}
2609 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2610 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2611 			       "Inode bitmap for group %u not in group "
2612 			       "(block %llu)!", i, inode_bitmap);
2613 			return 0;
2614 		}
2615 		inode_table = ext4_inode_table(sb, gdp);
2616 		if (inode_table == sb_block) {
2617 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2618 				 "Inode table for group %u overlaps "
2619 				 "superblock", i);
2620 			if (!sb_rdonly(sb))
2621 				return 0;
2622 		}
2623 		if (inode_table >= sb_block + 1 &&
2624 		    inode_table <= last_bg_block) {
2625 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2626 				 "Inode table for group %u overlaps "
2627 				 "block group descriptors", i);
2628 			if (!sb_rdonly(sb))
2629 				return 0;
2630 		}
2631 		if (inode_table < first_block ||
2632 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2633 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2634 			       "Inode table for group %u not in group "
2635 			       "(block %llu)!", i, inode_table);
2636 			return 0;
2637 		}
2638 		ext4_lock_group(sb, i);
2639 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2640 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2641 				 "Checksum for group %u failed (%u!=%u)",
2642 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2643 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2644 			if (!sb_rdonly(sb)) {
2645 				ext4_unlock_group(sb, i);
2646 				return 0;
2647 			}
2648 		}
2649 		ext4_unlock_group(sb, i);
2650 		if (!flexbg_flag)
2651 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2652 	}
2653 	if (NULL != first_not_zeroed)
2654 		*first_not_zeroed = grp;
2655 	return 1;
2656 }
2657 
2658 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2659  * the superblock) which were deleted from all directories, but held open by
2660  * a process at the time of a crash.  We walk the list and try to delete these
2661  * inodes at recovery time (only with a read-write filesystem).
2662  *
2663  * In order to keep the orphan inode chain consistent during traversal (in
2664  * case of crash during recovery), we link each inode into the superblock
2665  * orphan list_head and handle it the same way as an inode deletion during
2666  * normal operation (which journals the operations for us).
2667  *
2668  * We only do an iget() and an iput() on each inode, which is very safe if we
2669  * accidentally point at an in-use or already deleted inode.  The worst that
2670  * can happen in this case is that we get a "bit already cleared" message from
2671  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2672  * e2fsck was run on this filesystem, and it must have already done the orphan
2673  * inode cleanup for us, so we can safely abort without any further action.
2674  */
2675 static void ext4_orphan_cleanup(struct super_block *sb,
2676 				struct ext4_super_block *es)
2677 {
2678 	unsigned int s_flags = sb->s_flags;
2679 	int ret, nr_orphans = 0, nr_truncates = 0;
2680 #ifdef CONFIG_QUOTA
2681 	int quota_update = 0;
2682 	int i;
2683 #endif
2684 	if (!es->s_last_orphan) {
2685 		jbd_debug(4, "no orphan inodes to clean up\n");
2686 		return;
2687 	}
2688 
2689 	if (bdev_read_only(sb->s_bdev)) {
2690 		ext4_msg(sb, KERN_ERR, "write access "
2691 			"unavailable, skipping orphan cleanup");
2692 		return;
2693 	}
2694 
2695 	/* Check if feature set would not allow a r/w mount */
2696 	if (!ext4_feature_set_ok(sb, 0)) {
2697 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2698 			 "unknown ROCOMPAT features");
2699 		return;
2700 	}
2701 
2702 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2703 		/* don't clear list on RO mount w/ errors */
2704 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2705 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2706 				  "clearing orphan list.\n");
2707 			es->s_last_orphan = 0;
2708 		}
2709 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2710 		return;
2711 	}
2712 
2713 	if (s_flags & SB_RDONLY) {
2714 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2715 		sb->s_flags &= ~SB_RDONLY;
2716 	}
2717 #ifdef CONFIG_QUOTA
2718 	/* Needed for iput() to work correctly and not trash data */
2719 	sb->s_flags |= SB_ACTIVE;
2720 
2721 	/*
2722 	 * Turn on quotas which were not enabled for read-only mounts if
2723 	 * filesystem has quota feature, so that they are updated correctly.
2724 	 */
2725 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2726 		int ret = ext4_enable_quotas(sb);
2727 
2728 		if (!ret)
2729 			quota_update = 1;
2730 		else
2731 			ext4_msg(sb, KERN_ERR,
2732 				"Cannot turn on quotas: error %d", ret);
2733 	}
2734 
2735 	/* Turn on journaled quotas used for old sytle */
2736 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2737 		if (EXT4_SB(sb)->s_qf_names[i]) {
2738 			int ret = ext4_quota_on_mount(sb, i);
2739 
2740 			if (!ret)
2741 				quota_update = 1;
2742 			else
2743 				ext4_msg(sb, KERN_ERR,
2744 					"Cannot turn on journaled "
2745 					"quota: type %d: error %d", i, ret);
2746 		}
2747 	}
2748 #endif
2749 
2750 	while (es->s_last_orphan) {
2751 		struct inode *inode;
2752 
2753 		/*
2754 		 * We may have encountered an error during cleanup; if
2755 		 * so, skip the rest.
2756 		 */
2757 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2758 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2759 			es->s_last_orphan = 0;
2760 			break;
2761 		}
2762 
2763 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2764 		if (IS_ERR(inode)) {
2765 			es->s_last_orphan = 0;
2766 			break;
2767 		}
2768 
2769 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2770 		dquot_initialize(inode);
2771 		if (inode->i_nlink) {
2772 			if (test_opt(sb, DEBUG))
2773 				ext4_msg(sb, KERN_DEBUG,
2774 					"%s: truncating inode %lu to %lld bytes",
2775 					__func__, inode->i_ino, inode->i_size);
2776 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2777 				  inode->i_ino, inode->i_size);
2778 			inode_lock(inode);
2779 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2780 			ret = ext4_truncate(inode);
2781 			if (ret)
2782 				ext4_std_error(inode->i_sb, ret);
2783 			inode_unlock(inode);
2784 			nr_truncates++;
2785 		} else {
2786 			if (test_opt(sb, DEBUG))
2787 				ext4_msg(sb, KERN_DEBUG,
2788 					"%s: deleting unreferenced inode %lu",
2789 					__func__, inode->i_ino);
2790 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2791 				  inode->i_ino);
2792 			nr_orphans++;
2793 		}
2794 		iput(inode);  /* The delete magic happens here! */
2795 	}
2796 
2797 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2798 
2799 	if (nr_orphans)
2800 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2801 		       PLURAL(nr_orphans));
2802 	if (nr_truncates)
2803 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2804 		       PLURAL(nr_truncates));
2805 #ifdef CONFIG_QUOTA
2806 	/* Turn off quotas if they were enabled for orphan cleanup */
2807 	if (quota_update) {
2808 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2809 			if (sb_dqopt(sb)->files[i])
2810 				dquot_quota_off(sb, i);
2811 		}
2812 	}
2813 #endif
2814 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2815 }
2816 
2817 /*
2818  * Maximal extent format file size.
2819  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2820  * extent format containers, within a sector_t, and within i_blocks
2821  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2822  * so that won't be a limiting factor.
2823  *
2824  * However there is other limiting factor. We do store extents in the form
2825  * of starting block and length, hence the resulting length of the extent
2826  * covering maximum file size must fit into on-disk format containers as
2827  * well. Given that length is always by 1 unit bigger than max unit (because
2828  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2829  *
2830  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2831  */
2832 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2833 {
2834 	loff_t res;
2835 	loff_t upper_limit = MAX_LFS_FILESIZE;
2836 
2837 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2838 
2839 	if (!has_huge_files) {
2840 		upper_limit = (1LL << 32) - 1;
2841 
2842 		/* total blocks in file system block size */
2843 		upper_limit >>= (blkbits - 9);
2844 		upper_limit <<= blkbits;
2845 	}
2846 
2847 	/*
2848 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2849 	 * by one fs block, so ee_len can cover the extent of maximum file
2850 	 * size
2851 	 */
2852 	res = (1LL << 32) - 1;
2853 	res <<= blkbits;
2854 
2855 	/* Sanity check against vm- & vfs- imposed limits */
2856 	if (res > upper_limit)
2857 		res = upper_limit;
2858 
2859 	return res;
2860 }
2861 
2862 /*
2863  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2864  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2865  * We need to be 1 filesystem block less than the 2^48 sector limit.
2866  */
2867 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2868 {
2869 	loff_t res = EXT4_NDIR_BLOCKS;
2870 	int meta_blocks;
2871 	loff_t upper_limit;
2872 	/* This is calculated to be the largest file size for a dense, block
2873 	 * mapped file such that the file's total number of 512-byte sectors,
2874 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2875 	 *
2876 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2877 	 * number of 512-byte sectors of the file.
2878 	 */
2879 
2880 	if (!has_huge_files) {
2881 		/*
2882 		 * !has_huge_files or implies that the inode i_block field
2883 		 * represents total file blocks in 2^32 512-byte sectors ==
2884 		 * size of vfs inode i_blocks * 8
2885 		 */
2886 		upper_limit = (1LL << 32) - 1;
2887 
2888 		/* total blocks in file system block size */
2889 		upper_limit >>= (bits - 9);
2890 
2891 	} else {
2892 		/*
2893 		 * We use 48 bit ext4_inode i_blocks
2894 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2895 		 * represent total number of blocks in
2896 		 * file system block size
2897 		 */
2898 		upper_limit = (1LL << 48) - 1;
2899 
2900 	}
2901 
2902 	/* indirect blocks */
2903 	meta_blocks = 1;
2904 	/* double indirect blocks */
2905 	meta_blocks += 1 + (1LL << (bits-2));
2906 	/* tripple indirect blocks */
2907 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2908 
2909 	upper_limit -= meta_blocks;
2910 	upper_limit <<= bits;
2911 
2912 	res += 1LL << (bits-2);
2913 	res += 1LL << (2*(bits-2));
2914 	res += 1LL << (3*(bits-2));
2915 	res <<= bits;
2916 	if (res > upper_limit)
2917 		res = upper_limit;
2918 
2919 	if (res > MAX_LFS_FILESIZE)
2920 		res = MAX_LFS_FILESIZE;
2921 
2922 	return res;
2923 }
2924 
2925 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2926 				   ext4_fsblk_t logical_sb_block, int nr)
2927 {
2928 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2929 	ext4_group_t bg, first_meta_bg;
2930 	int has_super = 0;
2931 
2932 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2933 
2934 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2935 		return logical_sb_block + nr + 1;
2936 	bg = sbi->s_desc_per_block * nr;
2937 	if (ext4_bg_has_super(sb, bg))
2938 		has_super = 1;
2939 
2940 	/*
2941 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2942 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2943 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2944 	 * compensate.
2945 	 */
2946 	if (sb->s_blocksize == 1024 && nr == 0 &&
2947 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2948 		has_super++;
2949 
2950 	return (has_super + ext4_group_first_block_no(sb, bg));
2951 }
2952 
2953 /**
2954  * ext4_get_stripe_size: Get the stripe size.
2955  * @sbi: In memory super block info
2956  *
2957  * If we have specified it via mount option, then
2958  * use the mount option value. If the value specified at mount time is
2959  * greater than the blocks per group use the super block value.
2960  * If the super block value is greater than blocks per group return 0.
2961  * Allocator needs it be less than blocks per group.
2962  *
2963  */
2964 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2965 {
2966 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2967 	unsigned long stripe_width =
2968 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2969 	int ret;
2970 
2971 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2972 		ret = sbi->s_stripe;
2973 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2974 		ret = stripe_width;
2975 	else if (stride && stride <= sbi->s_blocks_per_group)
2976 		ret = stride;
2977 	else
2978 		ret = 0;
2979 
2980 	/*
2981 	 * If the stripe width is 1, this makes no sense and
2982 	 * we set it to 0 to turn off stripe handling code.
2983 	 */
2984 	if (ret <= 1)
2985 		ret = 0;
2986 
2987 	return ret;
2988 }
2989 
2990 /*
2991  * Check whether this filesystem can be mounted based on
2992  * the features present and the RDONLY/RDWR mount requested.
2993  * Returns 1 if this filesystem can be mounted as requested,
2994  * 0 if it cannot be.
2995  */
2996 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2997 {
2998 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2999 		ext4_msg(sb, KERN_ERR,
3000 			"Couldn't mount because of "
3001 			"unsupported optional features (%x)",
3002 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3003 			~EXT4_FEATURE_INCOMPAT_SUPP));
3004 		return 0;
3005 	}
3006 
3007 #ifndef CONFIG_UNICODE
3008 	if (ext4_has_feature_casefold(sb)) {
3009 		ext4_msg(sb, KERN_ERR,
3010 			 "Filesystem with casefold feature cannot be "
3011 			 "mounted without CONFIG_UNICODE");
3012 		return 0;
3013 	}
3014 #endif
3015 
3016 	if (readonly)
3017 		return 1;
3018 
3019 	if (ext4_has_feature_readonly(sb)) {
3020 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3021 		sb->s_flags |= SB_RDONLY;
3022 		return 1;
3023 	}
3024 
3025 	/* Check that feature set is OK for a read-write mount */
3026 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3027 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3028 			 "unsupported optional features (%x)",
3029 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3030 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3031 		return 0;
3032 	}
3033 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3034 		ext4_msg(sb, KERN_ERR,
3035 			 "Can't support bigalloc feature without "
3036 			 "extents feature\n");
3037 		return 0;
3038 	}
3039 
3040 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3041 	if (!readonly && (ext4_has_feature_quota(sb) ||
3042 			  ext4_has_feature_project(sb))) {
3043 		ext4_msg(sb, KERN_ERR,
3044 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3045 		return 0;
3046 	}
3047 #endif  /* CONFIG_QUOTA */
3048 	return 1;
3049 }
3050 
3051 /*
3052  * This function is called once a day if we have errors logged
3053  * on the file system
3054  */
3055 static void print_daily_error_info(struct timer_list *t)
3056 {
3057 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3058 	struct super_block *sb = sbi->s_sb;
3059 	struct ext4_super_block *es = sbi->s_es;
3060 
3061 	if (es->s_error_count)
3062 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3063 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3064 			 le32_to_cpu(es->s_error_count));
3065 	if (es->s_first_error_time) {
3066 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3067 		       sb->s_id,
3068 		       ext4_get_tstamp(es, s_first_error_time),
3069 		       (int) sizeof(es->s_first_error_func),
3070 		       es->s_first_error_func,
3071 		       le32_to_cpu(es->s_first_error_line));
3072 		if (es->s_first_error_ino)
3073 			printk(KERN_CONT ": inode %u",
3074 			       le32_to_cpu(es->s_first_error_ino));
3075 		if (es->s_first_error_block)
3076 			printk(KERN_CONT ": block %llu", (unsigned long long)
3077 			       le64_to_cpu(es->s_first_error_block));
3078 		printk(KERN_CONT "\n");
3079 	}
3080 	if (es->s_last_error_time) {
3081 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3082 		       sb->s_id,
3083 		       ext4_get_tstamp(es, s_last_error_time),
3084 		       (int) sizeof(es->s_last_error_func),
3085 		       es->s_last_error_func,
3086 		       le32_to_cpu(es->s_last_error_line));
3087 		if (es->s_last_error_ino)
3088 			printk(KERN_CONT ": inode %u",
3089 			       le32_to_cpu(es->s_last_error_ino));
3090 		if (es->s_last_error_block)
3091 			printk(KERN_CONT ": block %llu", (unsigned long long)
3092 			       le64_to_cpu(es->s_last_error_block));
3093 		printk(KERN_CONT "\n");
3094 	}
3095 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3096 }
3097 
3098 /* Find next suitable group and run ext4_init_inode_table */
3099 static int ext4_run_li_request(struct ext4_li_request *elr)
3100 {
3101 	struct ext4_group_desc *gdp = NULL;
3102 	ext4_group_t group, ngroups;
3103 	struct super_block *sb;
3104 	unsigned long timeout = 0;
3105 	int ret = 0;
3106 
3107 	sb = elr->lr_super;
3108 	ngroups = EXT4_SB(sb)->s_groups_count;
3109 
3110 	for (group = elr->lr_next_group; group < ngroups; group++) {
3111 		gdp = ext4_get_group_desc(sb, group, NULL);
3112 		if (!gdp) {
3113 			ret = 1;
3114 			break;
3115 		}
3116 
3117 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3118 			break;
3119 	}
3120 
3121 	if (group >= ngroups)
3122 		ret = 1;
3123 
3124 	if (!ret) {
3125 		timeout = jiffies;
3126 		ret = ext4_init_inode_table(sb, group,
3127 					    elr->lr_timeout ? 0 : 1);
3128 		if (elr->lr_timeout == 0) {
3129 			timeout = (jiffies - timeout) *
3130 				  elr->lr_sbi->s_li_wait_mult;
3131 			elr->lr_timeout = timeout;
3132 		}
3133 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3134 		elr->lr_next_group = group + 1;
3135 	}
3136 	return ret;
3137 }
3138 
3139 /*
3140  * Remove lr_request from the list_request and free the
3141  * request structure. Should be called with li_list_mtx held
3142  */
3143 static void ext4_remove_li_request(struct ext4_li_request *elr)
3144 {
3145 	struct ext4_sb_info *sbi;
3146 
3147 	if (!elr)
3148 		return;
3149 
3150 	sbi = elr->lr_sbi;
3151 
3152 	list_del(&elr->lr_request);
3153 	sbi->s_li_request = NULL;
3154 	kfree(elr);
3155 }
3156 
3157 static void ext4_unregister_li_request(struct super_block *sb)
3158 {
3159 	mutex_lock(&ext4_li_mtx);
3160 	if (!ext4_li_info) {
3161 		mutex_unlock(&ext4_li_mtx);
3162 		return;
3163 	}
3164 
3165 	mutex_lock(&ext4_li_info->li_list_mtx);
3166 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3167 	mutex_unlock(&ext4_li_info->li_list_mtx);
3168 	mutex_unlock(&ext4_li_mtx);
3169 }
3170 
3171 static struct task_struct *ext4_lazyinit_task;
3172 
3173 /*
3174  * This is the function where ext4lazyinit thread lives. It walks
3175  * through the request list searching for next scheduled filesystem.
3176  * When such a fs is found, run the lazy initialization request
3177  * (ext4_rn_li_request) and keep track of the time spend in this
3178  * function. Based on that time we compute next schedule time of
3179  * the request. When walking through the list is complete, compute
3180  * next waking time and put itself into sleep.
3181  */
3182 static int ext4_lazyinit_thread(void *arg)
3183 {
3184 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3185 	struct list_head *pos, *n;
3186 	struct ext4_li_request *elr;
3187 	unsigned long next_wakeup, cur;
3188 
3189 	BUG_ON(NULL == eli);
3190 
3191 cont_thread:
3192 	while (true) {
3193 		next_wakeup = MAX_JIFFY_OFFSET;
3194 
3195 		mutex_lock(&eli->li_list_mtx);
3196 		if (list_empty(&eli->li_request_list)) {
3197 			mutex_unlock(&eli->li_list_mtx);
3198 			goto exit_thread;
3199 		}
3200 		list_for_each_safe(pos, n, &eli->li_request_list) {
3201 			int err = 0;
3202 			int progress = 0;
3203 			elr = list_entry(pos, struct ext4_li_request,
3204 					 lr_request);
3205 
3206 			if (time_before(jiffies, elr->lr_next_sched)) {
3207 				if (time_before(elr->lr_next_sched, next_wakeup))
3208 					next_wakeup = elr->lr_next_sched;
3209 				continue;
3210 			}
3211 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3212 				if (sb_start_write_trylock(elr->lr_super)) {
3213 					progress = 1;
3214 					/*
3215 					 * We hold sb->s_umount, sb can not
3216 					 * be removed from the list, it is
3217 					 * now safe to drop li_list_mtx
3218 					 */
3219 					mutex_unlock(&eli->li_list_mtx);
3220 					err = ext4_run_li_request(elr);
3221 					sb_end_write(elr->lr_super);
3222 					mutex_lock(&eli->li_list_mtx);
3223 					n = pos->next;
3224 				}
3225 				up_read((&elr->lr_super->s_umount));
3226 			}
3227 			/* error, remove the lazy_init job */
3228 			if (err) {
3229 				ext4_remove_li_request(elr);
3230 				continue;
3231 			}
3232 			if (!progress) {
3233 				elr->lr_next_sched = jiffies +
3234 					(prandom_u32()
3235 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3236 			}
3237 			if (time_before(elr->lr_next_sched, next_wakeup))
3238 				next_wakeup = elr->lr_next_sched;
3239 		}
3240 		mutex_unlock(&eli->li_list_mtx);
3241 
3242 		try_to_freeze();
3243 
3244 		cur = jiffies;
3245 		if ((time_after_eq(cur, next_wakeup)) ||
3246 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3247 			cond_resched();
3248 			continue;
3249 		}
3250 
3251 		schedule_timeout_interruptible(next_wakeup - cur);
3252 
3253 		if (kthread_should_stop()) {
3254 			ext4_clear_request_list();
3255 			goto exit_thread;
3256 		}
3257 	}
3258 
3259 exit_thread:
3260 	/*
3261 	 * It looks like the request list is empty, but we need
3262 	 * to check it under the li_list_mtx lock, to prevent any
3263 	 * additions into it, and of course we should lock ext4_li_mtx
3264 	 * to atomically free the list and ext4_li_info, because at
3265 	 * this point another ext4 filesystem could be registering
3266 	 * new one.
3267 	 */
3268 	mutex_lock(&ext4_li_mtx);
3269 	mutex_lock(&eli->li_list_mtx);
3270 	if (!list_empty(&eli->li_request_list)) {
3271 		mutex_unlock(&eli->li_list_mtx);
3272 		mutex_unlock(&ext4_li_mtx);
3273 		goto cont_thread;
3274 	}
3275 	mutex_unlock(&eli->li_list_mtx);
3276 	kfree(ext4_li_info);
3277 	ext4_li_info = NULL;
3278 	mutex_unlock(&ext4_li_mtx);
3279 
3280 	return 0;
3281 }
3282 
3283 static void ext4_clear_request_list(void)
3284 {
3285 	struct list_head *pos, *n;
3286 	struct ext4_li_request *elr;
3287 
3288 	mutex_lock(&ext4_li_info->li_list_mtx);
3289 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3290 		elr = list_entry(pos, struct ext4_li_request,
3291 				 lr_request);
3292 		ext4_remove_li_request(elr);
3293 	}
3294 	mutex_unlock(&ext4_li_info->li_list_mtx);
3295 }
3296 
3297 static int ext4_run_lazyinit_thread(void)
3298 {
3299 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3300 					 ext4_li_info, "ext4lazyinit");
3301 	if (IS_ERR(ext4_lazyinit_task)) {
3302 		int err = PTR_ERR(ext4_lazyinit_task);
3303 		ext4_clear_request_list();
3304 		kfree(ext4_li_info);
3305 		ext4_li_info = NULL;
3306 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3307 				 "initialization thread\n",
3308 				 err);
3309 		return err;
3310 	}
3311 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3312 	return 0;
3313 }
3314 
3315 /*
3316  * Check whether it make sense to run itable init. thread or not.
3317  * If there is at least one uninitialized inode table, return
3318  * corresponding group number, else the loop goes through all
3319  * groups and return total number of groups.
3320  */
3321 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3322 {
3323 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3324 	struct ext4_group_desc *gdp = NULL;
3325 
3326 	if (!ext4_has_group_desc_csum(sb))
3327 		return ngroups;
3328 
3329 	for (group = 0; group < ngroups; group++) {
3330 		gdp = ext4_get_group_desc(sb, group, NULL);
3331 		if (!gdp)
3332 			continue;
3333 
3334 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3335 			break;
3336 	}
3337 
3338 	return group;
3339 }
3340 
3341 static int ext4_li_info_new(void)
3342 {
3343 	struct ext4_lazy_init *eli = NULL;
3344 
3345 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3346 	if (!eli)
3347 		return -ENOMEM;
3348 
3349 	INIT_LIST_HEAD(&eli->li_request_list);
3350 	mutex_init(&eli->li_list_mtx);
3351 
3352 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3353 
3354 	ext4_li_info = eli;
3355 
3356 	return 0;
3357 }
3358 
3359 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3360 					    ext4_group_t start)
3361 {
3362 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3363 	struct ext4_li_request *elr;
3364 
3365 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3366 	if (!elr)
3367 		return NULL;
3368 
3369 	elr->lr_super = sb;
3370 	elr->lr_sbi = sbi;
3371 	elr->lr_next_group = start;
3372 
3373 	/*
3374 	 * Randomize first schedule time of the request to
3375 	 * spread the inode table initialization requests
3376 	 * better.
3377 	 */
3378 	elr->lr_next_sched = jiffies + (prandom_u32() %
3379 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3380 	return elr;
3381 }
3382 
3383 int ext4_register_li_request(struct super_block *sb,
3384 			     ext4_group_t first_not_zeroed)
3385 {
3386 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3387 	struct ext4_li_request *elr = NULL;
3388 	ext4_group_t ngroups = sbi->s_groups_count;
3389 	int ret = 0;
3390 
3391 	mutex_lock(&ext4_li_mtx);
3392 	if (sbi->s_li_request != NULL) {
3393 		/*
3394 		 * Reset timeout so it can be computed again, because
3395 		 * s_li_wait_mult might have changed.
3396 		 */
3397 		sbi->s_li_request->lr_timeout = 0;
3398 		goto out;
3399 	}
3400 
3401 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3402 	    !test_opt(sb, INIT_INODE_TABLE))
3403 		goto out;
3404 
3405 	elr = ext4_li_request_new(sb, first_not_zeroed);
3406 	if (!elr) {
3407 		ret = -ENOMEM;
3408 		goto out;
3409 	}
3410 
3411 	if (NULL == ext4_li_info) {
3412 		ret = ext4_li_info_new();
3413 		if (ret)
3414 			goto out;
3415 	}
3416 
3417 	mutex_lock(&ext4_li_info->li_list_mtx);
3418 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3419 	mutex_unlock(&ext4_li_info->li_list_mtx);
3420 
3421 	sbi->s_li_request = elr;
3422 	/*
3423 	 * set elr to NULL here since it has been inserted to
3424 	 * the request_list and the removal and free of it is
3425 	 * handled by ext4_clear_request_list from now on.
3426 	 */
3427 	elr = NULL;
3428 
3429 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3430 		ret = ext4_run_lazyinit_thread();
3431 		if (ret)
3432 			goto out;
3433 	}
3434 out:
3435 	mutex_unlock(&ext4_li_mtx);
3436 	if (ret)
3437 		kfree(elr);
3438 	return ret;
3439 }
3440 
3441 /*
3442  * We do not need to lock anything since this is called on
3443  * module unload.
3444  */
3445 static void ext4_destroy_lazyinit_thread(void)
3446 {
3447 	/*
3448 	 * If thread exited earlier
3449 	 * there's nothing to be done.
3450 	 */
3451 	if (!ext4_li_info || !ext4_lazyinit_task)
3452 		return;
3453 
3454 	kthread_stop(ext4_lazyinit_task);
3455 }
3456 
3457 static int set_journal_csum_feature_set(struct super_block *sb)
3458 {
3459 	int ret = 1;
3460 	int compat, incompat;
3461 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3462 
3463 	if (ext4_has_metadata_csum(sb)) {
3464 		/* journal checksum v3 */
3465 		compat = 0;
3466 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3467 	} else {
3468 		/* journal checksum v1 */
3469 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3470 		incompat = 0;
3471 	}
3472 
3473 	jbd2_journal_clear_features(sbi->s_journal,
3474 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3475 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3476 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3477 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3478 		ret = jbd2_journal_set_features(sbi->s_journal,
3479 				compat, 0,
3480 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3481 				incompat);
3482 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3483 		ret = jbd2_journal_set_features(sbi->s_journal,
3484 				compat, 0,
3485 				incompat);
3486 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3487 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3488 	} else {
3489 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3490 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3491 	}
3492 
3493 	return ret;
3494 }
3495 
3496 /*
3497  * Note: calculating the overhead so we can be compatible with
3498  * historical BSD practice is quite difficult in the face of
3499  * clusters/bigalloc.  This is because multiple metadata blocks from
3500  * different block group can end up in the same allocation cluster.
3501  * Calculating the exact overhead in the face of clustered allocation
3502  * requires either O(all block bitmaps) in memory or O(number of block
3503  * groups**2) in time.  We will still calculate the superblock for
3504  * older file systems --- and if we come across with a bigalloc file
3505  * system with zero in s_overhead_clusters the estimate will be close to
3506  * correct especially for very large cluster sizes --- but for newer
3507  * file systems, it's better to calculate this figure once at mkfs
3508  * time, and store it in the superblock.  If the superblock value is
3509  * present (even for non-bigalloc file systems), we will use it.
3510  */
3511 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3512 			  char *buf)
3513 {
3514 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3515 	struct ext4_group_desc	*gdp;
3516 	ext4_fsblk_t		first_block, last_block, b;
3517 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3518 	int			s, j, count = 0;
3519 
3520 	if (!ext4_has_feature_bigalloc(sb))
3521 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3522 			sbi->s_itb_per_group + 2);
3523 
3524 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3525 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3526 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3527 	for (i = 0; i < ngroups; i++) {
3528 		gdp = ext4_get_group_desc(sb, i, NULL);
3529 		b = ext4_block_bitmap(sb, gdp);
3530 		if (b >= first_block && b <= last_block) {
3531 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3532 			count++;
3533 		}
3534 		b = ext4_inode_bitmap(sb, gdp);
3535 		if (b >= first_block && b <= last_block) {
3536 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3537 			count++;
3538 		}
3539 		b = ext4_inode_table(sb, gdp);
3540 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3541 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3542 				int c = EXT4_B2C(sbi, b - first_block);
3543 				ext4_set_bit(c, buf);
3544 				count++;
3545 			}
3546 		if (i != grp)
3547 			continue;
3548 		s = 0;
3549 		if (ext4_bg_has_super(sb, grp)) {
3550 			ext4_set_bit(s++, buf);
3551 			count++;
3552 		}
3553 		j = ext4_bg_num_gdb(sb, grp);
3554 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3555 			ext4_error(sb, "Invalid number of block group "
3556 				   "descriptor blocks: %d", j);
3557 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3558 		}
3559 		count += j;
3560 		for (; j > 0; j--)
3561 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3562 	}
3563 	if (!count)
3564 		return 0;
3565 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3566 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3567 }
3568 
3569 /*
3570  * Compute the overhead and stash it in sbi->s_overhead
3571  */
3572 int ext4_calculate_overhead(struct super_block *sb)
3573 {
3574 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3575 	struct ext4_super_block *es = sbi->s_es;
3576 	struct inode *j_inode;
3577 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3578 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3579 	ext4_fsblk_t overhead = 0;
3580 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3581 
3582 	if (!buf)
3583 		return -ENOMEM;
3584 
3585 	/*
3586 	 * Compute the overhead (FS structures).  This is constant
3587 	 * for a given filesystem unless the number of block groups
3588 	 * changes so we cache the previous value until it does.
3589 	 */
3590 
3591 	/*
3592 	 * All of the blocks before first_data_block are overhead
3593 	 */
3594 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3595 
3596 	/*
3597 	 * Add the overhead found in each block group
3598 	 */
3599 	for (i = 0; i < ngroups; i++) {
3600 		int blks;
3601 
3602 		blks = count_overhead(sb, i, buf);
3603 		overhead += blks;
3604 		if (blks)
3605 			memset(buf, 0, PAGE_SIZE);
3606 		cond_resched();
3607 	}
3608 
3609 	/*
3610 	 * Add the internal journal blocks whether the journal has been
3611 	 * loaded or not
3612 	 */
3613 	if (sbi->s_journal && !sbi->journal_bdev)
3614 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3615 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
3616 		/* j_inum for internal journal is non-zero */
3617 		j_inode = ext4_get_journal_inode(sb, j_inum);
3618 		if (j_inode) {
3619 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3620 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3621 			iput(j_inode);
3622 		} else {
3623 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3624 		}
3625 	}
3626 	sbi->s_overhead = overhead;
3627 	smp_wmb();
3628 	free_page((unsigned long) buf);
3629 	return 0;
3630 }
3631 
3632 static void ext4_set_resv_clusters(struct super_block *sb)
3633 {
3634 	ext4_fsblk_t resv_clusters;
3635 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3636 
3637 	/*
3638 	 * There's no need to reserve anything when we aren't using extents.
3639 	 * The space estimates are exact, there are no unwritten extents,
3640 	 * hole punching doesn't need new metadata... This is needed especially
3641 	 * to keep ext2/3 backward compatibility.
3642 	 */
3643 	if (!ext4_has_feature_extents(sb))
3644 		return;
3645 	/*
3646 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3647 	 * This should cover the situations where we can not afford to run
3648 	 * out of space like for example punch hole, or converting
3649 	 * unwritten extents in delalloc path. In most cases such
3650 	 * allocation would require 1, or 2 blocks, higher numbers are
3651 	 * very rare.
3652 	 */
3653 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3654 			 sbi->s_cluster_bits);
3655 
3656 	do_div(resv_clusters, 50);
3657 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3658 
3659 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3660 }
3661 
3662 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3663 {
3664 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3665 	char *orig_data = kstrdup(data, GFP_KERNEL);
3666 	struct buffer_head *bh, **group_desc;
3667 	struct ext4_super_block *es = NULL;
3668 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3669 	struct flex_groups **flex_groups;
3670 	ext4_fsblk_t block;
3671 	ext4_fsblk_t sb_block = get_sb_block(&data);
3672 	ext4_fsblk_t logical_sb_block;
3673 	unsigned long offset = 0;
3674 	unsigned long journal_devnum = 0;
3675 	unsigned long def_mount_opts;
3676 	struct inode *root;
3677 	const char *descr;
3678 	int ret = -ENOMEM;
3679 	int blocksize, clustersize;
3680 	unsigned int db_count;
3681 	unsigned int i;
3682 	int needs_recovery, has_huge_files, has_bigalloc;
3683 	__u64 blocks_count;
3684 	int err = 0;
3685 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3686 	ext4_group_t first_not_zeroed;
3687 
3688 	if ((data && !orig_data) || !sbi)
3689 		goto out_free_base;
3690 
3691 	sbi->s_daxdev = dax_dev;
3692 	sbi->s_blockgroup_lock =
3693 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3694 	if (!sbi->s_blockgroup_lock)
3695 		goto out_free_base;
3696 
3697 	sb->s_fs_info = sbi;
3698 	sbi->s_sb = sb;
3699 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3700 	sbi->s_sb_block = sb_block;
3701 	if (sb->s_bdev->bd_part)
3702 		sbi->s_sectors_written_start =
3703 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3704 
3705 	/* Cleanup superblock name */
3706 	strreplace(sb->s_id, '/', '!');
3707 
3708 	/* -EINVAL is default */
3709 	ret = -EINVAL;
3710 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3711 	if (!blocksize) {
3712 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3713 		goto out_fail;
3714 	}
3715 
3716 	/*
3717 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3718 	 * block sizes.  We need to calculate the offset from buffer start.
3719 	 */
3720 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3721 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3722 		offset = do_div(logical_sb_block, blocksize);
3723 	} else {
3724 		logical_sb_block = sb_block;
3725 	}
3726 
3727 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3728 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3729 		goto out_fail;
3730 	}
3731 	/*
3732 	 * Note: s_es must be initialized as soon as possible because
3733 	 *       some ext4 macro-instructions depend on its value
3734 	 */
3735 	es = (struct ext4_super_block *) (bh->b_data + offset);
3736 	sbi->s_es = es;
3737 	sb->s_magic = le16_to_cpu(es->s_magic);
3738 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3739 		goto cantfind_ext4;
3740 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3741 
3742 	/* Warn if metadata_csum and gdt_csum are both set. */
3743 	if (ext4_has_feature_metadata_csum(sb) &&
3744 	    ext4_has_feature_gdt_csum(sb))
3745 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3746 			     "redundant flags; please run fsck.");
3747 
3748 	/* Check for a known checksum algorithm */
3749 	if (!ext4_verify_csum_type(sb, es)) {
3750 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3751 			 "unknown checksum algorithm.");
3752 		silent = 1;
3753 		goto cantfind_ext4;
3754 	}
3755 
3756 	/* Load the checksum driver */
3757 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3758 	if (IS_ERR(sbi->s_chksum_driver)) {
3759 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3760 		ret = PTR_ERR(sbi->s_chksum_driver);
3761 		sbi->s_chksum_driver = NULL;
3762 		goto failed_mount;
3763 	}
3764 
3765 	/* Check superblock checksum */
3766 	if (!ext4_superblock_csum_verify(sb, es)) {
3767 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3768 			 "invalid superblock checksum.  Run e2fsck?");
3769 		silent = 1;
3770 		ret = -EFSBADCRC;
3771 		goto cantfind_ext4;
3772 	}
3773 
3774 	/* Precompute checksum seed for all metadata */
3775 	if (ext4_has_feature_csum_seed(sb))
3776 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3777 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3778 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3779 					       sizeof(es->s_uuid));
3780 
3781 	/* Set defaults before we parse the mount options */
3782 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3783 	set_opt(sb, INIT_INODE_TABLE);
3784 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3785 		set_opt(sb, DEBUG);
3786 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3787 		set_opt(sb, GRPID);
3788 	if (def_mount_opts & EXT4_DEFM_UID16)
3789 		set_opt(sb, NO_UID32);
3790 	/* xattr user namespace & acls are now defaulted on */
3791 	set_opt(sb, XATTR_USER);
3792 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3793 	set_opt(sb, POSIX_ACL);
3794 #endif
3795 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3796 	if (ext4_has_metadata_csum(sb))
3797 		set_opt(sb, JOURNAL_CHECKSUM);
3798 
3799 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3800 		set_opt(sb, JOURNAL_DATA);
3801 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3802 		set_opt(sb, ORDERED_DATA);
3803 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3804 		set_opt(sb, WRITEBACK_DATA);
3805 
3806 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3807 		set_opt(sb, ERRORS_PANIC);
3808 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3809 		set_opt(sb, ERRORS_CONT);
3810 	else
3811 		set_opt(sb, ERRORS_RO);
3812 	/* block_validity enabled by default; disable with noblock_validity */
3813 	set_opt(sb, BLOCK_VALIDITY);
3814 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3815 		set_opt(sb, DISCARD);
3816 
3817 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3818 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3819 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3820 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3821 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3822 
3823 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3824 		set_opt(sb, BARRIER);
3825 
3826 	/*
3827 	 * enable delayed allocation by default
3828 	 * Use -o nodelalloc to turn it off
3829 	 */
3830 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3831 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3832 		set_opt(sb, DELALLOC);
3833 
3834 	/*
3835 	 * set default s_li_wait_mult for lazyinit, for the case there is
3836 	 * no mount option specified.
3837 	 */
3838 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3839 
3840 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3841 
3842 	if (blocksize == PAGE_SIZE)
3843 		set_opt(sb, DIOREAD_NOLOCK);
3844 
3845 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3846 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3847 		ext4_msg(sb, KERN_ERR,
3848 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3849 			 blocksize, le32_to_cpu(es->s_log_block_size));
3850 		goto failed_mount;
3851 	}
3852 
3853 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3854 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3855 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3856 	} else {
3857 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3858 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3859 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3860 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3861 				 sbi->s_first_ino);
3862 			goto failed_mount;
3863 		}
3864 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3865 		    (!is_power_of_2(sbi->s_inode_size)) ||
3866 		    (sbi->s_inode_size > blocksize)) {
3867 			ext4_msg(sb, KERN_ERR,
3868 			       "unsupported inode size: %d",
3869 			       sbi->s_inode_size);
3870 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
3871 			goto failed_mount;
3872 		}
3873 		/*
3874 		 * i_atime_extra is the last extra field available for
3875 		 * [acm]times in struct ext4_inode. Checking for that
3876 		 * field should suffice to ensure we have extra space
3877 		 * for all three.
3878 		 */
3879 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
3880 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
3881 			sb->s_time_gran = 1;
3882 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
3883 		} else {
3884 			sb->s_time_gran = NSEC_PER_SEC;
3885 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
3886 		}
3887 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
3888 	}
3889 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3890 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3891 			EXT4_GOOD_OLD_INODE_SIZE;
3892 		if (ext4_has_feature_extra_isize(sb)) {
3893 			unsigned v, max = (sbi->s_inode_size -
3894 					   EXT4_GOOD_OLD_INODE_SIZE);
3895 
3896 			v = le16_to_cpu(es->s_want_extra_isize);
3897 			if (v > max) {
3898 				ext4_msg(sb, KERN_ERR,
3899 					 "bad s_want_extra_isize: %d", v);
3900 				goto failed_mount;
3901 			}
3902 			if (sbi->s_want_extra_isize < v)
3903 				sbi->s_want_extra_isize = v;
3904 
3905 			v = le16_to_cpu(es->s_min_extra_isize);
3906 			if (v > max) {
3907 				ext4_msg(sb, KERN_ERR,
3908 					 "bad s_min_extra_isize: %d", v);
3909 				goto failed_mount;
3910 			}
3911 			if (sbi->s_want_extra_isize < v)
3912 				sbi->s_want_extra_isize = v;
3913 		}
3914 	}
3915 
3916 	if (sbi->s_es->s_mount_opts[0]) {
3917 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3918 					      sizeof(sbi->s_es->s_mount_opts),
3919 					      GFP_KERNEL);
3920 		if (!s_mount_opts)
3921 			goto failed_mount;
3922 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3923 				   &journal_ioprio, 0)) {
3924 			ext4_msg(sb, KERN_WARNING,
3925 				 "failed to parse options in superblock: %s",
3926 				 s_mount_opts);
3927 		}
3928 		kfree(s_mount_opts);
3929 	}
3930 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3931 	if (!parse_options((char *) data, sb, &journal_devnum,
3932 			   &journal_ioprio, 0))
3933 		goto failed_mount;
3934 
3935 #ifdef CONFIG_UNICODE
3936 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3937 		const struct ext4_sb_encodings *encoding_info;
3938 		struct unicode_map *encoding;
3939 		__u16 encoding_flags;
3940 
3941 		if (ext4_has_feature_encrypt(sb)) {
3942 			ext4_msg(sb, KERN_ERR,
3943 				 "Can't mount with encoding and encryption");
3944 			goto failed_mount;
3945 		}
3946 
3947 		if (ext4_sb_read_encoding(es, &encoding_info,
3948 					  &encoding_flags)) {
3949 			ext4_msg(sb, KERN_ERR,
3950 				 "Encoding requested by superblock is unknown");
3951 			goto failed_mount;
3952 		}
3953 
3954 		encoding = utf8_load(encoding_info->version);
3955 		if (IS_ERR(encoding)) {
3956 			ext4_msg(sb, KERN_ERR,
3957 				 "can't mount with superblock charset: %s-%s "
3958 				 "not supported by the kernel. flags: 0x%x.",
3959 				 encoding_info->name, encoding_info->version,
3960 				 encoding_flags);
3961 			goto failed_mount;
3962 		}
3963 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3964 			 "%s-%s with flags 0x%hx", encoding_info->name,
3965 			 encoding_info->version?:"\b", encoding_flags);
3966 
3967 		sbi->s_encoding = encoding;
3968 		sbi->s_encoding_flags = encoding_flags;
3969 	}
3970 #endif
3971 
3972 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3973 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!\n");
3974 		clear_opt(sb, DIOREAD_NOLOCK);
3975 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3976 			ext4_msg(sb, KERN_ERR, "can't mount with "
3977 				 "both data=journal and delalloc");
3978 			goto failed_mount;
3979 		}
3980 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3981 			ext4_msg(sb, KERN_ERR, "can't mount with "
3982 				 "both data=journal and dioread_nolock");
3983 			goto failed_mount;
3984 		}
3985 		if (test_opt(sb, DAX)) {
3986 			ext4_msg(sb, KERN_ERR, "can't mount with "
3987 				 "both data=journal and dax");
3988 			goto failed_mount;
3989 		}
3990 		if (ext4_has_feature_encrypt(sb)) {
3991 			ext4_msg(sb, KERN_WARNING,
3992 				 "encrypted files will use data=ordered "
3993 				 "instead of data journaling mode");
3994 		}
3995 		if (test_opt(sb, DELALLOC))
3996 			clear_opt(sb, DELALLOC);
3997 	} else {
3998 		sb->s_iflags |= SB_I_CGROUPWB;
3999 	}
4000 
4001 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4002 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4003 
4004 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4005 	    (ext4_has_compat_features(sb) ||
4006 	     ext4_has_ro_compat_features(sb) ||
4007 	     ext4_has_incompat_features(sb)))
4008 		ext4_msg(sb, KERN_WARNING,
4009 		       "feature flags set on rev 0 fs, "
4010 		       "running e2fsck is recommended");
4011 
4012 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4013 		set_opt2(sb, HURD_COMPAT);
4014 		if (ext4_has_feature_64bit(sb)) {
4015 			ext4_msg(sb, KERN_ERR,
4016 				 "The Hurd can't support 64-bit file systems");
4017 			goto failed_mount;
4018 		}
4019 
4020 		/*
4021 		 * ea_inode feature uses l_i_version field which is not
4022 		 * available in HURD_COMPAT mode.
4023 		 */
4024 		if (ext4_has_feature_ea_inode(sb)) {
4025 			ext4_msg(sb, KERN_ERR,
4026 				 "ea_inode feature is not supported for Hurd");
4027 			goto failed_mount;
4028 		}
4029 	}
4030 
4031 	if (IS_EXT2_SB(sb)) {
4032 		if (ext2_feature_set_ok(sb))
4033 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4034 				 "using the ext4 subsystem");
4035 		else {
4036 			/*
4037 			 * If we're probing be silent, if this looks like
4038 			 * it's actually an ext[34] filesystem.
4039 			 */
4040 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4041 				goto failed_mount;
4042 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4043 				 "to feature incompatibilities");
4044 			goto failed_mount;
4045 		}
4046 	}
4047 
4048 	if (IS_EXT3_SB(sb)) {
4049 		if (ext3_feature_set_ok(sb))
4050 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4051 				 "using the ext4 subsystem");
4052 		else {
4053 			/*
4054 			 * If we're probing be silent, if this looks like
4055 			 * it's actually an ext4 filesystem.
4056 			 */
4057 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4058 				goto failed_mount;
4059 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4060 				 "to feature incompatibilities");
4061 			goto failed_mount;
4062 		}
4063 	}
4064 
4065 	/*
4066 	 * Check feature flags regardless of the revision level, since we
4067 	 * previously didn't change the revision level when setting the flags,
4068 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4069 	 */
4070 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4071 		goto failed_mount;
4072 
4073 	if (le32_to_cpu(es->s_log_block_size) >
4074 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4075 		ext4_msg(sb, KERN_ERR,
4076 			 "Invalid log block size: %u",
4077 			 le32_to_cpu(es->s_log_block_size));
4078 		goto failed_mount;
4079 	}
4080 	if (le32_to_cpu(es->s_log_cluster_size) >
4081 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4082 		ext4_msg(sb, KERN_ERR,
4083 			 "Invalid log cluster size: %u",
4084 			 le32_to_cpu(es->s_log_cluster_size));
4085 		goto failed_mount;
4086 	}
4087 
4088 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4089 		ext4_msg(sb, KERN_ERR,
4090 			 "Number of reserved GDT blocks insanely large: %d",
4091 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4092 		goto failed_mount;
4093 	}
4094 
4095 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
4096 		if (ext4_has_feature_inline_data(sb)) {
4097 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4098 					" that may contain inline data");
4099 			goto failed_mount;
4100 		}
4101 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
4102 			ext4_msg(sb, KERN_ERR,
4103 				"DAX unsupported by block device.");
4104 			goto failed_mount;
4105 		}
4106 	}
4107 
4108 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4109 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4110 			 es->s_encryption_level);
4111 		goto failed_mount;
4112 	}
4113 
4114 	if (sb->s_blocksize != blocksize) {
4115 		/* Validate the filesystem blocksize */
4116 		if (!sb_set_blocksize(sb, blocksize)) {
4117 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4118 					blocksize);
4119 			goto failed_mount;
4120 		}
4121 
4122 		brelse(bh);
4123 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4124 		offset = do_div(logical_sb_block, blocksize);
4125 		bh = sb_bread_unmovable(sb, logical_sb_block);
4126 		if (!bh) {
4127 			ext4_msg(sb, KERN_ERR,
4128 			       "Can't read superblock on 2nd try");
4129 			goto failed_mount;
4130 		}
4131 		es = (struct ext4_super_block *)(bh->b_data + offset);
4132 		sbi->s_es = es;
4133 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4134 			ext4_msg(sb, KERN_ERR,
4135 			       "Magic mismatch, very weird!");
4136 			goto failed_mount;
4137 		}
4138 	}
4139 
4140 	has_huge_files = ext4_has_feature_huge_file(sb);
4141 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4142 						      has_huge_files);
4143 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4144 
4145 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4146 	if (ext4_has_feature_64bit(sb)) {
4147 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4148 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4149 		    !is_power_of_2(sbi->s_desc_size)) {
4150 			ext4_msg(sb, KERN_ERR,
4151 			       "unsupported descriptor size %lu",
4152 			       sbi->s_desc_size);
4153 			goto failed_mount;
4154 		}
4155 	} else
4156 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4157 
4158 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4159 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4160 
4161 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4162 	if (sbi->s_inodes_per_block == 0)
4163 		goto cantfind_ext4;
4164 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4165 	    sbi->s_inodes_per_group > blocksize * 8) {
4166 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4167 			 sbi->s_inodes_per_group);
4168 		goto failed_mount;
4169 	}
4170 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4171 					sbi->s_inodes_per_block;
4172 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4173 	sbi->s_sbh = bh;
4174 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4175 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4176 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4177 
4178 	for (i = 0; i < 4; i++)
4179 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4180 	sbi->s_def_hash_version = es->s_def_hash_version;
4181 	if (ext4_has_feature_dir_index(sb)) {
4182 		i = le32_to_cpu(es->s_flags);
4183 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4184 			sbi->s_hash_unsigned = 3;
4185 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4186 #ifdef __CHAR_UNSIGNED__
4187 			if (!sb_rdonly(sb))
4188 				es->s_flags |=
4189 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4190 			sbi->s_hash_unsigned = 3;
4191 #else
4192 			if (!sb_rdonly(sb))
4193 				es->s_flags |=
4194 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4195 #endif
4196 		}
4197 	}
4198 
4199 	/* Handle clustersize */
4200 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4201 	has_bigalloc = ext4_has_feature_bigalloc(sb);
4202 	if (has_bigalloc) {
4203 		if (clustersize < blocksize) {
4204 			ext4_msg(sb, KERN_ERR,
4205 				 "cluster size (%d) smaller than "
4206 				 "block size (%d)", clustersize, blocksize);
4207 			goto failed_mount;
4208 		}
4209 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4210 			le32_to_cpu(es->s_log_block_size);
4211 		sbi->s_clusters_per_group =
4212 			le32_to_cpu(es->s_clusters_per_group);
4213 		if (sbi->s_clusters_per_group > blocksize * 8) {
4214 			ext4_msg(sb, KERN_ERR,
4215 				 "#clusters per group too big: %lu",
4216 				 sbi->s_clusters_per_group);
4217 			goto failed_mount;
4218 		}
4219 		if (sbi->s_blocks_per_group !=
4220 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4221 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4222 				 "clusters per group (%lu) inconsistent",
4223 				 sbi->s_blocks_per_group,
4224 				 sbi->s_clusters_per_group);
4225 			goto failed_mount;
4226 		}
4227 	} else {
4228 		if (clustersize != blocksize) {
4229 			ext4_msg(sb, KERN_ERR,
4230 				 "fragment/cluster size (%d) != "
4231 				 "block size (%d)", clustersize, blocksize);
4232 			goto failed_mount;
4233 		}
4234 		if (sbi->s_blocks_per_group > blocksize * 8) {
4235 			ext4_msg(sb, KERN_ERR,
4236 				 "#blocks per group too big: %lu",
4237 				 sbi->s_blocks_per_group);
4238 			goto failed_mount;
4239 		}
4240 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4241 		sbi->s_cluster_bits = 0;
4242 	}
4243 	sbi->s_cluster_ratio = clustersize / blocksize;
4244 
4245 	/* Do we have standard group size of clustersize * 8 blocks ? */
4246 	if (sbi->s_blocks_per_group == clustersize << 3)
4247 		set_opt2(sb, STD_GROUP_SIZE);
4248 
4249 	/*
4250 	 * Test whether we have more sectors than will fit in sector_t,
4251 	 * and whether the max offset is addressable by the page cache.
4252 	 */
4253 	err = generic_check_addressable(sb->s_blocksize_bits,
4254 					ext4_blocks_count(es));
4255 	if (err) {
4256 		ext4_msg(sb, KERN_ERR, "filesystem"
4257 			 " too large to mount safely on this system");
4258 		goto failed_mount;
4259 	}
4260 
4261 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4262 		goto cantfind_ext4;
4263 
4264 	/* check blocks count against device size */
4265 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4266 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4267 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4268 		       "exceeds size of device (%llu blocks)",
4269 		       ext4_blocks_count(es), blocks_count);
4270 		goto failed_mount;
4271 	}
4272 
4273 	/*
4274 	 * It makes no sense for the first data block to be beyond the end
4275 	 * of the filesystem.
4276 	 */
4277 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4278 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4279 			 "block %u is beyond end of filesystem (%llu)",
4280 			 le32_to_cpu(es->s_first_data_block),
4281 			 ext4_blocks_count(es));
4282 		goto failed_mount;
4283 	}
4284 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4285 	    (sbi->s_cluster_ratio == 1)) {
4286 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4287 			 "block is 0 with a 1k block and cluster size");
4288 		goto failed_mount;
4289 	}
4290 
4291 	blocks_count = (ext4_blocks_count(es) -
4292 			le32_to_cpu(es->s_first_data_block) +
4293 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4294 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4295 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4296 		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4297 		       "(block count %llu, first data block %u, "
4298 		       "blocks per group %lu)", blocks_count,
4299 		       ext4_blocks_count(es),
4300 		       le32_to_cpu(es->s_first_data_block),
4301 		       EXT4_BLOCKS_PER_GROUP(sb));
4302 		goto failed_mount;
4303 	}
4304 	sbi->s_groups_count = blocks_count;
4305 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4306 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4307 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4308 	    le32_to_cpu(es->s_inodes_count)) {
4309 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4310 			 le32_to_cpu(es->s_inodes_count),
4311 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4312 		ret = -EINVAL;
4313 		goto failed_mount;
4314 	}
4315 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4316 		   EXT4_DESC_PER_BLOCK(sb);
4317 	if (ext4_has_feature_meta_bg(sb)) {
4318 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4319 			ext4_msg(sb, KERN_WARNING,
4320 				 "first meta block group too large: %u "
4321 				 "(group descriptor block count %u)",
4322 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4323 			goto failed_mount;
4324 		}
4325 	}
4326 	rcu_assign_pointer(sbi->s_group_desc,
4327 			   kvmalloc_array(db_count,
4328 					  sizeof(struct buffer_head *),
4329 					  GFP_KERNEL));
4330 	if (sbi->s_group_desc == NULL) {
4331 		ext4_msg(sb, KERN_ERR, "not enough memory");
4332 		ret = -ENOMEM;
4333 		goto failed_mount;
4334 	}
4335 
4336 	bgl_lock_init(sbi->s_blockgroup_lock);
4337 
4338 	/* Pre-read the descriptors into the buffer cache */
4339 	for (i = 0; i < db_count; i++) {
4340 		block = descriptor_loc(sb, logical_sb_block, i);
4341 		sb_breadahead_unmovable(sb, block);
4342 	}
4343 
4344 	for (i = 0; i < db_count; i++) {
4345 		struct buffer_head *bh;
4346 
4347 		block = descriptor_loc(sb, logical_sb_block, i);
4348 		bh = sb_bread_unmovable(sb, block);
4349 		if (!bh) {
4350 			ext4_msg(sb, KERN_ERR,
4351 			       "can't read group descriptor %d", i);
4352 			db_count = i;
4353 			goto failed_mount2;
4354 		}
4355 		rcu_read_lock();
4356 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4357 		rcu_read_unlock();
4358 	}
4359 	sbi->s_gdb_count = db_count;
4360 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4361 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4362 		ret = -EFSCORRUPTED;
4363 		goto failed_mount2;
4364 	}
4365 
4366 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4367 
4368 	/* Register extent status tree shrinker */
4369 	if (ext4_es_register_shrinker(sbi))
4370 		goto failed_mount3;
4371 
4372 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4373 	sbi->s_extent_max_zeroout_kb = 32;
4374 
4375 	/*
4376 	 * set up enough so that it can read an inode
4377 	 */
4378 	sb->s_op = &ext4_sops;
4379 	sb->s_export_op = &ext4_export_ops;
4380 	sb->s_xattr = ext4_xattr_handlers;
4381 #ifdef CONFIG_FS_ENCRYPTION
4382 	sb->s_cop = &ext4_cryptops;
4383 #endif
4384 #ifdef CONFIG_FS_VERITY
4385 	sb->s_vop = &ext4_verityops;
4386 #endif
4387 #ifdef CONFIG_QUOTA
4388 	sb->dq_op = &ext4_quota_operations;
4389 	if (ext4_has_feature_quota(sb))
4390 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4391 	else
4392 		sb->s_qcop = &ext4_qctl_operations;
4393 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4394 #endif
4395 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4396 
4397 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4398 	mutex_init(&sbi->s_orphan_lock);
4399 
4400 	sb->s_root = NULL;
4401 
4402 	needs_recovery = (es->s_last_orphan != 0 ||
4403 			  ext4_has_feature_journal_needs_recovery(sb));
4404 
4405 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4406 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4407 			goto failed_mount3a;
4408 
4409 	/*
4410 	 * The first inode we look at is the journal inode.  Don't try
4411 	 * root first: it may be modified in the journal!
4412 	 */
4413 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4414 		err = ext4_load_journal(sb, es, journal_devnum);
4415 		if (err)
4416 			goto failed_mount3a;
4417 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4418 		   ext4_has_feature_journal_needs_recovery(sb)) {
4419 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4420 		       "suppressed and not mounted read-only");
4421 		goto failed_mount_wq;
4422 	} else {
4423 		/* Nojournal mode, all journal mount options are illegal */
4424 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4425 			ext4_msg(sb, KERN_ERR, "can't mount with "
4426 				 "journal_checksum, fs mounted w/o journal");
4427 			goto failed_mount_wq;
4428 		}
4429 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4430 			ext4_msg(sb, KERN_ERR, "can't mount with "
4431 				 "journal_async_commit, fs mounted w/o journal");
4432 			goto failed_mount_wq;
4433 		}
4434 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4435 			ext4_msg(sb, KERN_ERR, "can't mount with "
4436 				 "commit=%lu, fs mounted w/o journal",
4437 				 sbi->s_commit_interval / HZ);
4438 			goto failed_mount_wq;
4439 		}
4440 		if (EXT4_MOUNT_DATA_FLAGS &
4441 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4442 			ext4_msg(sb, KERN_ERR, "can't mount with "
4443 				 "data=, fs mounted w/o journal");
4444 			goto failed_mount_wq;
4445 		}
4446 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4447 		clear_opt(sb, JOURNAL_CHECKSUM);
4448 		clear_opt(sb, DATA_FLAGS);
4449 		sbi->s_journal = NULL;
4450 		needs_recovery = 0;
4451 		goto no_journal;
4452 	}
4453 
4454 	if (ext4_has_feature_64bit(sb) &&
4455 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4456 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4457 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4458 		goto failed_mount_wq;
4459 	}
4460 
4461 	if (!set_journal_csum_feature_set(sb)) {
4462 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4463 			 "feature set");
4464 		goto failed_mount_wq;
4465 	}
4466 
4467 	/* We have now updated the journal if required, so we can
4468 	 * validate the data journaling mode. */
4469 	switch (test_opt(sb, DATA_FLAGS)) {
4470 	case 0:
4471 		/* No mode set, assume a default based on the journal
4472 		 * capabilities: ORDERED_DATA if the journal can
4473 		 * cope, else JOURNAL_DATA
4474 		 */
4475 		if (jbd2_journal_check_available_features
4476 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4477 			set_opt(sb, ORDERED_DATA);
4478 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4479 		} else {
4480 			set_opt(sb, JOURNAL_DATA);
4481 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4482 		}
4483 		break;
4484 
4485 	case EXT4_MOUNT_ORDERED_DATA:
4486 	case EXT4_MOUNT_WRITEBACK_DATA:
4487 		if (!jbd2_journal_check_available_features
4488 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4489 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4490 			       "requested data journaling mode");
4491 			goto failed_mount_wq;
4492 		}
4493 	default:
4494 		break;
4495 	}
4496 
4497 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4498 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4499 		ext4_msg(sb, KERN_ERR, "can't mount with "
4500 			"journal_async_commit in data=ordered mode");
4501 		goto failed_mount_wq;
4502 	}
4503 
4504 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4505 
4506 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4507 
4508 no_journal:
4509 	if (!test_opt(sb, NO_MBCACHE)) {
4510 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4511 		if (!sbi->s_ea_block_cache) {
4512 			ext4_msg(sb, KERN_ERR,
4513 				 "Failed to create ea_block_cache");
4514 			goto failed_mount_wq;
4515 		}
4516 
4517 		if (ext4_has_feature_ea_inode(sb)) {
4518 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4519 			if (!sbi->s_ea_inode_cache) {
4520 				ext4_msg(sb, KERN_ERR,
4521 					 "Failed to create ea_inode_cache");
4522 				goto failed_mount_wq;
4523 			}
4524 		}
4525 	}
4526 
4527 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4528 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4529 		goto failed_mount_wq;
4530 	}
4531 
4532 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4533 	    !ext4_has_feature_encrypt(sb)) {
4534 		ext4_set_feature_encrypt(sb);
4535 		ext4_commit_super(sb, 1);
4536 	}
4537 
4538 	/*
4539 	 * Get the # of file system overhead blocks from the
4540 	 * superblock if present.
4541 	 */
4542 	if (es->s_overhead_clusters)
4543 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4544 	else {
4545 		err = ext4_calculate_overhead(sb);
4546 		if (err)
4547 			goto failed_mount_wq;
4548 	}
4549 
4550 	/*
4551 	 * The maximum number of concurrent works can be high and
4552 	 * concurrency isn't really necessary.  Limit it to 1.
4553 	 */
4554 	EXT4_SB(sb)->rsv_conversion_wq =
4555 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4556 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4557 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4558 		ret = -ENOMEM;
4559 		goto failed_mount4;
4560 	}
4561 
4562 	/*
4563 	 * The jbd2_journal_load will have done any necessary log recovery,
4564 	 * so we can safely mount the rest of the filesystem now.
4565 	 */
4566 
4567 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4568 	if (IS_ERR(root)) {
4569 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4570 		ret = PTR_ERR(root);
4571 		root = NULL;
4572 		goto failed_mount4;
4573 	}
4574 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4575 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4576 		iput(root);
4577 		goto failed_mount4;
4578 	}
4579 
4580 #ifdef CONFIG_UNICODE
4581 	if (sbi->s_encoding)
4582 		sb->s_d_op = &ext4_dentry_ops;
4583 #endif
4584 
4585 	sb->s_root = d_make_root(root);
4586 	if (!sb->s_root) {
4587 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4588 		ret = -ENOMEM;
4589 		goto failed_mount4;
4590 	}
4591 
4592 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4593 	if (ret == -EROFS) {
4594 		sb->s_flags |= SB_RDONLY;
4595 		ret = 0;
4596 	} else if (ret)
4597 		goto failed_mount4a;
4598 
4599 	ext4_set_resv_clusters(sb);
4600 
4601 	err = ext4_setup_system_zone(sb);
4602 	if (err) {
4603 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4604 			 "zone (%d)", err);
4605 		goto failed_mount4a;
4606 	}
4607 
4608 	ext4_ext_init(sb);
4609 	err = ext4_mb_init(sb);
4610 	if (err) {
4611 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4612 			 err);
4613 		goto failed_mount5;
4614 	}
4615 
4616 	block = ext4_count_free_clusters(sb);
4617 	ext4_free_blocks_count_set(sbi->s_es,
4618 				   EXT4_C2B(sbi, block));
4619 	ext4_superblock_csum_set(sb);
4620 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4621 				  GFP_KERNEL);
4622 	if (!err) {
4623 		unsigned long freei = ext4_count_free_inodes(sb);
4624 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4625 		ext4_superblock_csum_set(sb);
4626 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4627 					  GFP_KERNEL);
4628 	}
4629 	if (!err)
4630 		err = percpu_counter_init(&sbi->s_dirs_counter,
4631 					  ext4_count_dirs(sb), GFP_KERNEL);
4632 	if (!err)
4633 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4634 					  GFP_KERNEL);
4635 	if (!err)
4636 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
4637 
4638 	if (err) {
4639 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4640 		goto failed_mount6;
4641 	}
4642 
4643 	if (ext4_has_feature_flex_bg(sb))
4644 		if (!ext4_fill_flex_info(sb)) {
4645 			ext4_msg(sb, KERN_ERR,
4646 			       "unable to initialize "
4647 			       "flex_bg meta info!");
4648 			goto failed_mount6;
4649 		}
4650 
4651 	err = ext4_register_li_request(sb, first_not_zeroed);
4652 	if (err)
4653 		goto failed_mount6;
4654 
4655 	err = ext4_register_sysfs(sb);
4656 	if (err)
4657 		goto failed_mount7;
4658 
4659 #ifdef CONFIG_QUOTA
4660 	/* Enable quota usage during mount. */
4661 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4662 		err = ext4_enable_quotas(sb);
4663 		if (err)
4664 			goto failed_mount8;
4665 	}
4666 #endif  /* CONFIG_QUOTA */
4667 
4668 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4669 	ext4_orphan_cleanup(sb, es);
4670 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4671 	if (needs_recovery) {
4672 		ext4_msg(sb, KERN_INFO, "recovery complete");
4673 		ext4_mark_recovery_complete(sb, es);
4674 	}
4675 	if (EXT4_SB(sb)->s_journal) {
4676 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4677 			descr = " journalled data mode";
4678 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4679 			descr = " ordered data mode";
4680 		else
4681 			descr = " writeback data mode";
4682 	} else
4683 		descr = "out journal";
4684 
4685 	if (test_opt(sb, DISCARD)) {
4686 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4687 		if (!blk_queue_discard(q))
4688 			ext4_msg(sb, KERN_WARNING,
4689 				 "mounting with \"discard\" option, but "
4690 				 "the device does not support discard");
4691 	}
4692 
4693 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4694 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4695 			 "Opts: %.*s%s%s", descr,
4696 			 (int) sizeof(sbi->s_es->s_mount_opts),
4697 			 sbi->s_es->s_mount_opts,
4698 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4699 
4700 	if (es->s_error_count)
4701 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4702 
4703 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4704 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4705 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4706 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4707 
4708 	kfree(orig_data);
4709 	return 0;
4710 
4711 cantfind_ext4:
4712 	if (!silent)
4713 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4714 	goto failed_mount;
4715 
4716 #ifdef CONFIG_QUOTA
4717 failed_mount8:
4718 	ext4_unregister_sysfs(sb);
4719 #endif
4720 failed_mount7:
4721 	ext4_unregister_li_request(sb);
4722 failed_mount6:
4723 	ext4_mb_release(sb);
4724 	rcu_read_lock();
4725 	flex_groups = rcu_dereference(sbi->s_flex_groups);
4726 	if (flex_groups) {
4727 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
4728 			kvfree(flex_groups[i]);
4729 		kvfree(flex_groups);
4730 	}
4731 	rcu_read_unlock();
4732 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4733 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4734 	percpu_counter_destroy(&sbi->s_dirs_counter);
4735 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4736 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
4737 failed_mount5:
4738 	ext4_ext_release(sb);
4739 	ext4_release_system_zone(sb);
4740 failed_mount4a:
4741 	dput(sb->s_root);
4742 	sb->s_root = NULL;
4743 failed_mount4:
4744 	ext4_msg(sb, KERN_ERR, "mount failed");
4745 	if (EXT4_SB(sb)->rsv_conversion_wq)
4746 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4747 failed_mount_wq:
4748 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4749 	sbi->s_ea_inode_cache = NULL;
4750 
4751 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4752 	sbi->s_ea_block_cache = NULL;
4753 
4754 	if (sbi->s_journal) {
4755 		jbd2_journal_destroy(sbi->s_journal);
4756 		sbi->s_journal = NULL;
4757 	}
4758 failed_mount3a:
4759 	ext4_es_unregister_shrinker(sbi);
4760 failed_mount3:
4761 	del_timer_sync(&sbi->s_err_report);
4762 	if (sbi->s_mmp_tsk)
4763 		kthread_stop(sbi->s_mmp_tsk);
4764 failed_mount2:
4765 	rcu_read_lock();
4766 	group_desc = rcu_dereference(sbi->s_group_desc);
4767 	for (i = 0; i < db_count; i++)
4768 		brelse(group_desc[i]);
4769 	kvfree(group_desc);
4770 	rcu_read_unlock();
4771 failed_mount:
4772 	if (sbi->s_chksum_driver)
4773 		crypto_free_shash(sbi->s_chksum_driver);
4774 
4775 #ifdef CONFIG_UNICODE
4776 	utf8_unload(sbi->s_encoding);
4777 #endif
4778 
4779 #ifdef CONFIG_QUOTA
4780 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4781 		kfree(get_qf_name(sb, sbi, i));
4782 #endif
4783 	ext4_blkdev_remove(sbi);
4784 	brelse(bh);
4785 out_fail:
4786 	sb->s_fs_info = NULL;
4787 	kfree(sbi->s_blockgroup_lock);
4788 out_free_base:
4789 	kfree(sbi);
4790 	kfree(orig_data);
4791 	fs_put_dax(dax_dev);
4792 	return err ? err : ret;
4793 }
4794 
4795 /*
4796  * Setup any per-fs journal parameters now.  We'll do this both on
4797  * initial mount, once the journal has been initialised but before we've
4798  * done any recovery; and again on any subsequent remount.
4799  */
4800 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4801 {
4802 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4803 
4804 	journal->j_commit_interval = sbi->s_commit_interval;
4805 	journal->j_min_batch_time = sbi->s_min_batch_time;
4806 	journal->j_max_batch_time = sbi->s_max_batch_time;
4807 
4808 	write_lock(&journal->j_state_lock);
4809 	if (test_opt(sb, BARRIER))
4810 		journal->j_flags |= JBD2_BARRIER;
4811 	else
4812 		journal->j_flags &= ~JBD2_BARRIER;
4813 	if (test_opt(sb, DATA_ERR_ABORT))
4814 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4815 	else
4816 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4817 	write_unlock(&journal->j_state_lock);
4818 }
4819 
4820 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4821 					     unsigned int journal_inum)
4822 {
4823 	struct inode *journal_inode;
4824 
4825 	/*
4826 	 * Test for the existence of a valid inode on disk.  Bad things
4827 	 * happen if we iget() an unused inode, as the subsequent iput()
4828 	 * will try to delete it.
4829 	 */
4830 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4831 	if (IS_ERR(journal_inode)) {
4832 		ext4_msg(sb, KERN_ERR, "no journal found");
4833 		return NULL;
4834 	}
4835 	if (!journal_inode->i_nlink) {
4836 		make_bad_inode(journal_inode);
4837 		iput(journal_inode);
4838 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4839 		return NULL;
4840 	}
4841 
4842 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4843 		  journal_inode, journal_inode->i_size);
4844 	if (!S_ISREG(journal_inode->i_mode)) {
4845 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4846 		iput(journal_inode);
4847 		return NULL;
4848 	}
4849 	return journal_inode;
4850 }
4851 
4852 static journal_t *ext4_get_journal(struct super_block *sb,
4853 				   unsigned int journal_inum)
4854 {
4855 	struct inode *journal_inode;
4856 	journal_t *journal;
4857 
4858 	BUG_ON(!ext4_has_feature_journal(sb));
4859 
4860 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4861 	if (!journal_inode)
4862 		return NULL;
4863 
4864 	journal = jbd2_journal_init_inode(journal_inode);
4865 	if (!journal) {
4866 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4867 		iput(journal_inode);
4868 		return NULL;
4869 	}
4870 	journal->j_private = sb;
4871 	ext4_init_journal_params(sb, journal);
4872 	return journal;
4873 }
4874 
4875 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4876 				       dev_t j_dev)
4877 {
4878 	struct buffer_head *bh;
4879 	journal_t *journal;
4880 	ext4_fsblk_t start;
4881 	ext4_fsblk_t len;
4882 	int hblock, blocksize;
4883 	ext4_fsblk_t sb_block;
4884 	unsigned long offset;
4885 	struct ext4_super_block *es;
4886 	struct block_device *bdev;
4887 
4888 	BUG_ON(!ext4_has_feature_journal(sb));
4889 
4890 	bdev = ext4_blkdev_get(j_dev, sb);
4891 	if (bdev == NULL)
4892 		return NULL;
4893 
4894 	blocksize = sb->s_blocksize;
4895 	hblock = bdev_logical_block_size(bdev);
4896 	if (blocksize < hblock) {
4897 		ext4_msg(sb, KERN_ERR,
4898 			"blocksize too small for journal device");
4899 		goto out_bdev;
4900 	}
4901 
4902 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4903 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4904 	set_blocksize(bdev, blocksize);
4905 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4906 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4907 		       "external journal");
4908 		goto out_bdev;
4909 	}
4910 
4911 	es = (struct ext4_super_block *) (bh->b_data + offset);
4912 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4913 	    !(le32_to_cpu(es->s_feature_incompat) &
4914 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4915 		ext4_msg(sb, KERN_ERR, "external journal has "
4916 					"bad superblock");
4917 		brelse(bh);
4918 		goto out_bdev;
4919 	}
4920 
4921 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4922 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4923 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4924 		ext4_msg(sb, KERN_ERR, "external journal has "
4925 				       "corrupt superblock");
4926 		brelse(bh);
4927 		goto out_bdev;
4928 	}
4929 
4930 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4931 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4932 		brelse(bh);
4933 		goto out_bdev;
4934 	}
4935 
4936 	len = ext4_blocks_count(es);
4937 	start = sb_block + 1;
4938 	brelse(bh);	/* we're done with the superblock */
4939 
4940 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4941 					start, len, blocksize);
4942 	if (!journal) {
4943 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4944 		goto out_bdev;
4945 	}
4946 	journal->j_private = sb;
4947 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4948 	wait_on_buffer(journal->j_sb_buffer);
4949 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4950 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4951 		goto out_journal;
4952 	}
4953 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4954 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4955 					"user (unsupported) - %d",
4956 			be32_to_cpu(journal->j_superblock->s_nr_users));
4957 		goto out_journal;
4958 	}
4959 	EXT4_SB(sb)->journal_bdev = bdev;
4960 	ext4_init_journal_params(sb, journal);
4961 	return journal;
4962 
4963 out_journal:
4964 	jbd2_journal_destroy(journal);
4965 out_bdev:
4966 	ext4_blkdev_put(bdev);
4967 	return NULL;
4968 }
4969 
4970 static int ext4_load_journal(struct super_block *sb,
4971 			     struct ext4_super_block *es,
4972 			     unsigned long journal_devnum)
4973 {
4974 	journal_t *journal;
4975 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4976 	dev_t journal_dev;
4977 	int err = 0;
4978 	int really_read_only;
4979 
4980 	BUG_ON(!ext4_has_feature_journal(sb));
4981 
4982 	if (journal_devnum &&
4983 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4984 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4985 			"numbers have changed");
4986 		journal_dev = new_decode_dev(journal_devnum);
4987 	} else
4988 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4989 
4990 	really_read_only = bdev_read_only(sb->s_bdev);
4991 
4992 	/*
4993 	 * Are we loading a blank journal or performing recovery after a
4994 	 * crash?  For recovery, we need to check in advance whether we
4995 	 * can get read-write access to the device.
4996 	 */
4997 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4998 		if (sb_rdonly(sb)) {
4999 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
5000 					"required on readonly filesystem");
5001 			if (really_read_only) {
5002 				ext4_msg(sb, KERN_ERR, "write access "
5003 					"unavailable, cannot proceed "
5004 					"(try mounting with noload)");
5005 				return -EROFS;
5006 			}
5007 			ext4_msg(sb, KERN_INFO, "write access will "
5008 			       "be enabled during recovery");
5009 		}
5010 	}
5011 
5012 	if (journal_inum && journal_dev) {
5013 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
5014 		       "and inode journals!");
5015 		return -EINVAL;
5016 	}
5017 
5018 	if (journal_inum) {
5019 		if (!(journal = ext4_get_journal(sb, journal_inum)))
5020 			return -EINVAL;
5021 	} else {
5022 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
5023 			return -EINVAL;
5024 	}
5025 
5026 	if (!(journal->j_flags & JBD2_BARRIER))
5027 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5028 
5029 	if (!ext4_has_feature_journal_needs_recovery(sb))
5030 		err = jbd2_journal_wipe(journal, !really_read_only);
5031 	if (!err) {
5032 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5033 		if (save)
5034 			memcpy(save, ((char *) es) +
5035 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5036 		err = jbd2_journal_load(journal);
5037 		if (save)
5038 			memcpy(((char *) es) + EXT4_S_ERR_START,
5039 			       save, EXT4_S_ERR_LEN);
5040 		kfree(save);
5041 	}
5042 
5043 	if (err) {
5044 		ext4_msg(sb, KERN_ERR, "error loading journal");
5045 		jbd2_journal_destroy(journal);
5046 		return err;
5047 	}
5048 
5049 	EXT4_SB(sb)->s_journal = journal;
5050 	ext4_clear_journal_err(sb, es);
5051 
5052 	if (!really_read_only && journal_devnum &&
5053 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5054 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5055 
5056 		/* Make sure we flush the recovery flag to disk. */
5057 		ext4_commit_super(sb, 1);
5058 	}
5059 
5060 	return 0;
5061 }
5062 
5063 static int ext4_commit_super(struct super_block *sb, int sync)
5064 {
5065 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5066 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5067 	int error = 0;
5068 
5069 	if (!sbh || block_device_ejected(sb))
5070 		return error;
5071 
5072 	/*
5073 	 * The superblock bh should be mapped, but it might not be if the
5074 	 * device was hot-removed. Not much we can do but fail the I/O.
5075 	 */
5076 	if (!buffer_mapped(sbh))
5077 		return error;
5078 
5079 	/*
5080 	 * If the file system is mounted read-only, don't update the
5081 	 * superblock write time.  This avoids updating the superblock
5082 	 * write time when we are mounting the root file system
5083 	 * read/only but we need to replay the journal; at that point,
5084 	 * for people who are east of GMT and who make their clock
5085 	 * tick in localtime for Windows bug-for-bug compatibility,
5086 	 * the clock is set in the future, and this will cause e2fsck
5087 	 * to complain and force a full file system check.
5088 	 */
5089 	if (!(sb->s_flags & SB_RDONLY))
5090 		ext4_update_tstamp(es, s_wtime);
5091 	if (sb->s_bdev->bd_part)
5092 		es->s_kbytes_written =
5093 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5094 			    ((part_stat_read(sb->s_bdev->bd_part,
5095 					     sectors[STAT_WRITE]) -
5096 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5097 	else
5098 		es->s_kbytes_written =
5099 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5100 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5101 		ext4_free_blocks_count_set(es,
5102 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5103 				&EXT4_SB(sb)->s_freeclusters_counter)));
5104 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5105 		es->s_free_inodes_count =
5106 			cpu_to_le32(percpu_counter_sum_positive(
5107 				&EXT4_SB(sb)->s_freeinodes_counter));
5108 	BUFFER_TRACE(sbh, "marking dirty");
5109 	ext4_superblock_csum_set(sb);
5110 	if (sync)
5111 		lock_buffer(sbh);
5112 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5113 		/*
5114 		 * Oh, dear.  A previous attempt to write the
5115 		 * superblock failed.  This could happen because the
5116 		 * USB device was yanked out.  Or it could happen to
5117 		 * be a transient write error and maybe the block will
5118 		 * be remapped.  Nothing we can do but to retry the
5119 		 * write and hope for the best.
5120 		 */
5121 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5122 		       "superblock detected");
5123 		clear_buffer_write_io_error(sbh);
5124 		set_buffer_uptodate(sbh);
5125 	}
5126 	mark_buffer_dirty(sbh);
5127 	if (sync) {
5128 		unlock_buffer(sbh);
5129 		error = __sync_dirty_buffer(sbh,
5130 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5131 		if (buffer_write_io_error(sbh)) {
5132 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5133 			       "superblock");
5134 			clear_buffer_write_io_error(sbh);
5135 			set_buffer_uptodate(sbh);
5136 		}
5137 	}
5138 	return error;
5139 }
5140 
5141 /*
5142  * Have we just finished recovery?  If so, and if we are mounting (or
5143  * remounting) the filesystem readonly, then we will end up with a
5144  * consistent fs on disk.  Record that fact.
5145  */
5146 static void ext4_mark_recovery_complete(struct super_block *sb,
5147 					struct ext4_super_block *es)
5148 {
5149 	journal_t *journal = EXT4_SB(sb)->s_journal;
5150 
5151 	if (!ext4_has_feature_journal(sb)) {
5152 		BUG_ON(journal != NULL);
5153 		return;
5154 	}
5155 	jbd2_journal_lock_updates(journal);
5156 	if (jbd2_journal_flush(journal) < 0)
5157 		goto out;
5158 
5159 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5160 		ext4_clear_feature_journal_needs_recovery(sb);
5161 		ext4_commit_super(sb, 1);
5162 	}
5163 
5164 out:
5165 	jbd2_journal_unlock_updates(journal);
5166 }
5167 
5168 /*
5169  * If we are mounting (or read-write remounting) a filesystem whose journal
5170  * has recorded an error from a previous lifetime, move that error to the
5171  * main filesystem now.
5172  */
5173 static void ext4_clear_journal_err(struct super_block *sb,
5174 				   struct ext4_super_block *es)
5175 {
5176 	journal_t *journal;
5177 	int j_errno;
5178 	const char *errstr;
5179 
5180 	BUG_ON(!ext4_has_feature_journal(sb));
5181 
5182 	journal = EXT4_SB(sb)->s_journal;
5183 
5184 	/*
5185 	 * Now check for any error status which may have been recorded in the
5186 	 * journal by a prior ext4_error() or ext4_abort()
5187 	 */
5188 
5189 	j_errno = jbd2_journal_errno(journal);
5190 	if (j_errno) {
5191 		char nbuf[16];
5192 
5193 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5194 		ext4_warning(sb, "Filesystem error recorded "
5195 			     "from previous mount: %s", errstr);
5196 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5197 
5198 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5199 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5200 		ext4_commit_super(sb, 1);
5201 
5202 		jbd2_journal_clear_err(journal);
5203 		jbd2_journal_update_sb_errno(journal);
5204 	}
5205 }
5206 
5207 /*
5208  * Force the running and committing transactions to commit,
5209  * and wait on the commit.
5210  */
5211 int ext4_force_commit(struct super_block *sb)
5212 {
5213 	journal_t *journal;
5214 
5215 	if (sb_rdonly(sb))
5216 		return 0;
5217 
5218 	journal = EXT4_SB(sb)->s_journal;
5219 	return ext4_journal_force_commit(journal);
5220 }
5221 
5222 static int ext4_sync_fs(struct super_block *sb, int wait)
5223 {
5224 	int ret = 0;
5225 	tid_t target;
5226 	bool needs_barrier = false;
5227 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5228 
5229 	if (unlikely(ext4_forced_shutdown(sbi)))
5230 		return 0;
5231 
5232 	trace_ext4_sync_fs(sb, wait);
5233 	flush_workqueue(sbi->rsv_conversion_wq);
5234 	/*
5235 	 * Writeback quota in non-journalled quota case - journalled quota has
5236 	 * no dirty dquots
5237 	 */
5238 	dquot_writeback_dquots(sb, -1);
5239 	/*
5240 	 * Data writeback is possible w/o journal transaction, so barrier must
5241 	 * being sent at the end of the function. But we can skip it if
5242 	 * transaction_commit will do it for us.
5243 	 */
5244 	if (sbi->s_journal) {
5245 		target = jbd2_get_latest_transaction(sbi->s_journal);
5246 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5247 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5248 			needs_barrier = true;
5249 
5250 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5251 			if (wait)
5252 				ret = jbd2_log_wait_commit(sbi->s_journal,
5253 							   target);
5254 		}
5255 	} else if (wait && test_opt(sb, BARRIER))
5256 		needs_barrier = true;
5257 	if (needs_barrier) {
5258 		int err;
5259 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5260 		if (!ret)
5261 			ret = err;
5262 	}
5263 
5264 	return ret;
5265 }
5266 
5267 /*
5268  * LVM calls this function before a (read-only) snapshot is created.  This
5269  * gives us a chance to flush the journal completely and mark the fs clean.
5270  *
5271  * Note that only this function cannot bring a filesystem to be in a clean
5272  * state independently. It relies on upper layer to stop all data & metadata
5273  * modifications.
5274  */
5275 static int ext4_freeze(struct super_block *sb)
5276 {
5277 	int error = 0;
5278 	journal_t *journal;
5279 
5280 	if (sb_rdonly(sb))
5281 		return 0;
5282 
5283 	journal = EXT4_SB(sb)->s_journal;
5284 
5285 	if (journal) {
5286 		/* Now we set up the journal barrier. */
5287 		jbd2_journal_lock_updates(journal);
5288 
5289 		/*
5290 		 * Don't clear the needs_recovery flag if we failed to
5291 		 * flush the journal.
5292 		 */
5293 		error = jbd2_journal_flush(journal);
5294 		if (error < 0)
5295 			goto out;
5296 
5297 		/* Journal blocked and flushed, clear needs_recovery flag. */
5298 		ext4_clear_feature_journal_needs_recovery(sb);
5299 	}
5300 
5301 	error = ext4_commit_super(sb, 1);
5302 out:
5303 	if (journal)
5304 		/* we rely on upper layer to stop further updates */
5305 		jbd2_journal_unlock_updates(journal);
5306 	return error;
5307 }
5308 
5309 /*
5310  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5311  * flag here, even though the filesystem is not technically dirty yet.
5312  */
5313 static int ext4_unfreeze(struct super_block *sb)
5314 {
5315 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5316 		return 0;
5317 
5318 	if (EXT4_SB(sb)->s_journal) {
5319 		/* Reset the needs_recovery flag before the fs is unlocked. */
5320 		ext4_set_feature_journal_needs_recovery(sb);
5321 	}
5322 
5323 	ext4_commit_super(sb, 1);
5324 	return 0;
5325 }
5326 
5327 /*
5328  * Structure to save mount options for ext4_remount's benefit
5329  */
5330 struct ext4_mount_options {
5331 	unsigned long s_mount_opt;
5332 	unsigned long s_mount_opt2;
5333 	kuid_t s_resuid;
5334 	kgid_t s_resgid;
5335 	unsigned long s_commit_interval;
5336 	u32 s_min_batch_time, s_max_batch_time;
5337 #ifdef CONFIG_QUOTA
5338 	int s_jquota_fmt;
5339 	char *s_qf_names[EXT4_MAXQUOTAS];
5340 #endif
5341 };
5342 
5343 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5344 {
5345 	struct ext4_super_block *es;
5346 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5347 	unsigned long old_sb_flags;
5348 	struct ext4_mount_options old_opts;
5349 	int enable_quota = 0;
5350 	ext4_group_t g;
5351 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5352 	int err = 0;
5353 #ifdef CONFIG_QUOTA
5354 	int i, j;
5355 	char *to_free[EXT4_MAXQUOTAS];
5356 #endif
5357 	char *orig_data = kstrdup(data, GFP_KERNEL);
5358 
5359 	if (data && !orig_data)
5360 		return -ENOMEM;
5361 
5362 	/* Store the original options */
5363 	old_sb_flags = sb->s_flags;
5364 	old_opts.s_mount_opt = sbi->s_mount_opt;
5365 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5366 	old_opts.s_resuid = sbi->s_resuid;
5367 	old_opts.s_resgid = sbi->s_resgid;
5368 	old_opts.s_commit_interval = sbi->s_commit_interval;
5369 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5370 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5371 #ifdef CONFIG_QUOTA
5372 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5373 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5374 		if (sbi->s_qf_names[i]) {
5375 			char *qf_name = get_qf_name(sb, sbi, i);
5376 
5377 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5378 			if (!old_opts.s_qf_names[i]) {
5379 				for (j = 0; j < i; j++)
5380 					kfree(old_opts.s_qf_names[j]);
5381 				kfree(orig_data);
5382 				return -ENOMEM;
5383 			}
5384 		} else
5385 			old_opts.s_qf_names[i] = NULL;
5386 #endif
5387 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5388 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5389 
5390 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5391 		err = -EINVAL;
5392 		goto restore_opts;
5393 	}
5394 
5395 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5396 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5397 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5398 			 "during remount not supported; ignoring");
5399 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5400 	}
5401 
5402 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5403 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5404 			ext4_msg(sb, KERN_ERR, "can't mount with "
5405 				 "both data=journal and delalloc");
5406 			err = -EINVAL;
5407 			goto restore_opts;
5408 		}
5409 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5410 			ext4_msg(sb, KERN_ERR, "can't mount with "
5411 				 "both data=journal and dioread_nolock");
5412 			err = -EINVAL;
5413 			goto restore_opts;
5414 		}
5415 		if (test_opt(sb, DAX)) {
5416 			ext4_msg(sb, KERN_ERR, "can't mount with "
5417 				 "both data=journal and dax");
5418 			err = -EINVAL;
5419 			goto restore_opts;
5420 		}
5421 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5422 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5423 			ext4_msg(sb, KERN_ERR, "can't mount with "
5424 				"journal_async_commit in data=ordered mode");
5425 			err = -EINVAL;
5426 			goto restore_opts;
5427 		}
5428 	}
5429 
5430 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5431 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5432 		err = -EINVAL;
5433 		goto restore_opts;
5434 	}
5435 
5436 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5437 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5438 			"dax flag with busy inodes while remounting");
5439 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5440 	}
5441 
5442 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5443 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
5444 
5445 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5446 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5447 
5448 	es = sbi->s_es;
5449 
5450 	if (sbi->s_journal) {
5451 		ext4_init_journal_params(sb, sbi->s_journal);
5452 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5453 	}
5454 
5455 	if (*flags & SB_LAZYTIME)
5456 		sb->s_flags |= SB_LAZYTIME;
5457 
5458 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5459 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5460 			err = -EROFS;
5461 			goto restore_opts;
5462 		}
5463 
5464 		if (*flags & SB_RDONLY) {
5465 			err = sync_filesystem(sb);
5466 			if (err < 0)
5467 				goto restore_opts;
5468 			err = dquot_suspend(sb, -1);
5469 			if (err < 0)
5470 				goto restore_opts;
5471 
5472 			/*
5473 			 * First of all, the unconditional stuff we have to do
5474 			 * to disable replay of the journal when we next remount
5475 			 */
5476 			sb->s_flags |= SB_RDONLY;
5477 
5478 			/*
5479 			 * OK, test if we are remounting a valid rw partition
5480 			 * readonly, and if so set the rdonly flag and then
5481 			 * mark the partition as valid again.
5482 			 */
5483 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5484 			    (sbi->s_mount_state & EXT4_VALID_FS))
5485 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5486 
5487 			if (sbi->s_journal)
5488 				ext4_mark_recovery_complete(sb, es);
5489 			if (sbi->s_mmp_tsk)
5490 				kthread_stop(sbi->s_mmp_tsk);
5491 		} else {
5492 			/* Make sure we can mount this feature set readwrite */
5493 			if (ext4_has_feature_readonly(sb) ||
5494 			    !ext4_feature_set_ok(sb, 0)) {
5495 				err = -EROFS;
5496 				goto restore_opts;
5497 			}
5498 			/*
5499 			 * Make sure the group descriptor checksums
5500 			 * are sane.  If they aren't, refuse to remount r/w.
5501 			 */
5502 			for (g = 0; g < sbi->s_groups_count; g++) {
5503 				struct ext4_group_desc *gdp =
5504 					ext4_get_group_desc(sb, g, NULL);
5505 
5506 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5507 					ext4_msg(sb, KERN_ERR,
5508 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5509 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5510 					       le16_to_cpu(gdp->bg_checksum));
5511 					err = -EFSBADCRC;
5512 					goto restore_opts;
5513 				}
5514 			}
5515 
5516 			/*
5517 			 * If we have an unprocessed orphan list hanging
5518 			 * around from a previously readonly bdev mount,
5519 			 * require a full umount/remount for now.
5520 			 */
5521 			if (es->s_last_orphan) {
5522 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5523 				       "remount RDWR because of unprocessed "
5524 				       "orphan inode list.  Please "
5525 				       "umount/remount instead");
5526 				err = -EINVAL;
5527 				goto restore_opts;
5528 			}
5529 
5530 			/*
5531 			 * Mounting a RDONLY partition read-write, so reread
5532 			 * and store the current valid flag.  (It may have
5533 			 * been changed by e2fsck since we originally mounted
5534 			 * the partition.)
5535 			 */
5536 			if (sbi->s_journal)
5537 				ext4_clear_journal_err(sb, es);
5538 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5539 
5540 			err = ext4_setup_super(sb, es, 0);
5541 			if (err)
5542 				goto restore_opts;
5543 
5544 			sb->s_flags &= ~SB_RDONLY;
5545 			if (ext4_has_feature_mmp(sb))
5546 				if (ext4_multi_mount_protect(sb,
5547 						le64_to_cpu(es->s_mmp_block))) {
5548 					err = -EROFS;
5549 					goto restore_opts;
5550 				}
5551 			enable_quota = 1;
5552 		}
5553 	}
5554 
5555 	/*
5556 	 * Reinitialize lazy itable initialization thread based on
5557 	 * current settings
5558 	 */
5559 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5560 		ext4_unregister_li_request(sb);
5561 	else {
5562 		ext4_group_t first_not_zeroed;
5563 		first_not_zeroed = ext4_has_uninit_itable(sb);
5564 		ext4_register_li_request(sb, first_not_zeroed);
5565 	}
5566 
5567 	ext4_setup_system_zone(sb);
5568 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5569 		err = ext4_commit_super(sb, 1);
5570 		if (err)
5571 			goto restore_opts;
5572 	}
5573 
5574 #ifdef CONFIG_QUOTA
5575 	/* Release old quota file names */
5576 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5577 		kfree(old_opts.s_qf_names[i]);
5578 	if (enable_quota) {
5579 		if (sb_any_quota_suspended(sb))
5580 			dquot_resume(sb, -1);
5581 		else if (ext4_has_feature_quota(sb)) {
5582 			err = ext4_enable_quotas(sb);
5583 			if (err)
5584 				goto restore_opts;
5585 		}
5586 	}
5587 #endif
5588 
5589 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5590 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5591 	kfree(orig_data);
5592 	return 0;
5593 
5594 restore_opts:
5595 	sb->s_flags = old_sb_flags;
5596 	sbi->s_mount_opt = old_opts.s_mount_opt;
5597 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5598 	sbi->s_resuid = old_opts.s_resuid;
5599 	sbi->s_resgid = old_opts.s_resgid;
5600 	sbi->s_commit_interval = old_opts.s_commit_interval;
5601 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5602 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5603 #ifdef CONFIG_QUOTA
5604 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5605 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5606 		to_free[i] = get_qf_name(sb, sbi, i);
5607 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5608 	}
5609 	synchronize_rcu();
5610 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5611 		kfree(to_free[i]);
5612 #endif
5613 	kfree(orig_data);
5614 	return err;
5615 }
5616 
5617 #ifdef CONFIG_QUOTA
5618 static int ext4_statfs_project(struct super_block *sb,
5619 			       kprojid_t projid, struct kstatfs *buf)
5620 {
5621 	struct kqid qid;
5622 	struct dquot *dquot;
5623 	u64 limit;
5624 	u64 curblock;
5625 
5626 	qid = make_kqid_projid(projid);
5627 	dquot = dqget(sb, qid);
5628 	if (IS_ERR(dquot))
5629 		return PTR_ERR(dquot);
5630 	spin_lock(&dquot->dq_dqb_lock);
5631 
5632 	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
5633 			     dquot->dq_dqb.dqb_bhardlimit);
5634 	limit >>= sb->s_blocksize_bits;
5635 
5636 	if (limit && buf->f_blocks > limit) {
5637 		curblock = (dquot->dq_dqb.dqb_curspace +
5638 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5639 		buf->f_blocks = limit;
5640 		buf->f_bfree = buf->f_bavail =
5641 			(buf->f_blocks > curblock) ?
5642 			 (buf->f_blocks - curblock) : 0;
5643 	}
5644 
5645 	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
5646 			     dquot->dq_dqb.dqb_ihardlimit);
5647 	if (limit && buf->f_files > limit) {
5648 		buf->f_files = limit;
5649 		buf->f_ffree =
5650 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5651 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5652 	}
5653 
5654 	spin_unlock(&dquot->dq_dqb_lock);
5655 	dqput(dquot);
5656 	return 0;
5657 }
5658 #endif
5659 
5660 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5661 {
5662 	struct super_block *sb = dentry->d_sb;
5663 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5664 	struct ext4_super_block *es = sbi->s_es;
5665 	ext4_fsblk_t overhead = 0, resv_blocks;
5666 	u64 fsid;
5667 	s64 bfree;
5668 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5669 
5670 	if (!test_opt(sb, MINIX_DF))
5671 		overhead = sbi->s_overhead;
5672 
5673 	buf->f_type = EXT4_SUPER_MAGIC;
5674 	buf->f_bsize = sb->s_blocksize;
5675 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5676 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5677 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5678 	/* prevent underflow in case that few free space is available */
5679 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5680 	buf->f_bavail = buf->f_bfree -
5681 			(ext4_r_blocks_count(es) + resv_blocks);
5682 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5683 		buf->f_bavail = 0;
5684 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5685 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5686 	buf->f_namelen = EXT4_NAME_LEN;
5687 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5688 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5689 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5690 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5691 
5692 #ifdef CONFIG_QUOTA
5693 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5694 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5695 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5696 #endif
5697 	return 0;
5698 }
5699 
5700 
5701 #ifdef CONFIG_QUOTA
5702 
5703 /*
5704  * Helper functions so that transaction is started before we acquire dqio_sem
5705  * to keep correct lock ordering of transaction > dqio_sem
5706  */
5707 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5708 {
5709 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5710 }
5711 
5712 static int ext4_write_dquot(struct dquot *dquot)
5713 {
5714 	int ret, err;
5715 	handle_t *handle;
5716 	struct inode *inode;
5717 
5718 	inode = dquot_to_inode(dquot);
5719 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5720 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5721 	if (IS_ERR(handle))
5722 		return PTR_ERR(handle);
5723 	ret = dquot_commit(dquot);
5724 	err = ext4_journal_stop(handle);
5725 	if (!ret)
5726 		ret = err;
5727 	return ret;
5728 }
5729 
5730 static int ext4_acquire_dquot(struct dquot *dquot)
5731 {
5732 	int ret, err;
5733 	handle_t *handle;
5734 
5735 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5736 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5737 	if (IS_ERR(handle))
5738 		return PTR_ERR(handle);
5739 	ret = dquot_acquire(dquot);
5740 	err = ext4_journal_stop(handle);
5741 	if (!ret)
5742 		ret = err;
5743 	return ret;
5744 }
5745 
5746 static int ext4_release_dquot(struct dquot *dquot)
5747 {
5748 	int ret, err;
5749 	handle_t *handle;
5750 
5751 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5752 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5753 	if (IS_ERR(handle)) {
5754 		/* Release dquot anyway to avoid endless cycle in dqput() */
5755 		dquot_release(dquot);
5756 		return PTR_ERR(handle);
5757 	}
5758 	ret = dquot_release(dquot);
5759 	err = ext4_journal_stop(handle);
5760 	if (!ret)
5761 		ret = err;
5762 	return ret;
5763 }
5764 
5765 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5766 {
5767 	struct super_block *sb = dquot->dq_sb;
5768 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5769 
5770 	/* Are we journaling quotas? */
5771 	if (ext4_has_feature_quota(sb) ||
5772 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5773 		dquot_mark_dquot_dirty(dquot);
5774 		return ext4_write_dquot(dquot);
5775 	} else {
5776 		return dquot_mark_dquot_dirty(dquot);
5777 	}
5778 }
5779 
5780 static int ext4_write_info(struct super_block *sb, int type)
5781 {
5782 	int ret, err;
5783 	handle_t *handle;
5784 
5785 	/* Data block + inode block */
5786 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5787 	if (IS_ERR(handle))
5788 		return PTR_ERR(handle);
5789 	ret = dquot_commit_info(sb, type);
5790 	err = ext4_journal_stop(handle);
5791 	if (!ret)
5792 		ret = err;
5793 	return ret;
5794 }
5795 
5796 /*
5797  * Turn on quotas during mount time - we need to find
5798  * the quota file and such...
5799  */
5800 static int ext4_quota_on_mount(struct super_block *sb, int type)
5801 {
5802 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5803 					EXT4_SB(sb)->s_jquota_fmt, type);
5804 }
5805 
5806 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5807 {
5808 	struct ext4_inode_info *ei = EXT4_I(inode);
5809 
5810 	/* The first argument of lockdep_set_subclass has to be
5811 	 * *exactly* the same as the argument to init_rwsem() --- in
5812 	 * this case, in init_once() --- or lockdep gets unhappy
5813 	 * because the name of the lock is set using the
5814 	 * stringification of the argument to init_rwsem().
5815 	 */
5816 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5817 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5818 }
5819 
5820 /*
5821  * Standard function to be called on quota_on
5822  */
5823 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5824 			 const struct path *path)
5825 {
5826 	int err;
5827 
5828 	if (!test_opt(sb, QUOTA))
5829 		return -EINVAL;
5830 
5831 	/* Quotafile not on the same filesystem? */
5832 	if (path->dentry->d_sb != sb)
5833 		return -EXDEV;
5834 	/* Journaling quota? */
5835 	if (EXT4_SB(sb)->s_qf_names[type]) {
5836 		/* Quotafile not in fs root? */
5837 		if (path->dentry->d_parent != sb->s_root)
5838 			ext4_msg(sb, KERN_WARNING,
5839 				"Quota file not on filesystem root. "
5840 				"Journaled quota will not work");
5841 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5842 	} else {
5843 		/*
5844 		 * Clear the flag just in case mount options changed since
5845 		 * last time.
5846 		 */
5847 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5848 	}
5849 
5850 	/*
5851 	 * When we journal data on quota file, we have to flush journal to see
5852 	 * all updates to the file when we bypass pagecache...
5853 	 */
5854 	if (EXT4_SB(sb)->s_journal &&
5855 	    ext4_should_journal_data(d_inode(path->dentry))) {
5856 		/*
5857 		 * We don't need to lock updates but journal_flush() could
5858 		 * otherwise be livelocked...
5859 		 */
5860 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5861 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5862 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5863 		if (err)
5864 			return err;
5865 	}
5866 
5867 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5868 	err = dquot_quota_on(sb, type, format_id, path);
5869 	if (err) {
5870 		lockdep_set_quota_inode(path->dentry->d_inode,
5871 					     I_DATA_SEM_NORMAL);
5872 	} else {
5873 		struct inode *inode = d_inode(path->dentry);
5874 		handle_t *handle;
5875 
5876 		/*
5877 		 * Set inode flags to prevent userspace from messing with quota
5878 		 * files. If this fails, we return success anyway since quotas
5879 		 * are already enabled and this is not a hard failure.
5880 		 */
5881 		inode_lock(inode);
5882 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5883 		if (IS_ERR(handle))
5884 			goto unlock_inode;
5885 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5886 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5887 				S_NOATIME | S_IMMUTABLE);
5888 		ext4_mark_inode_dirty(handle, inode);
5889 		ext4_journal_stop(handle);
5890 	unlock_inode:
5891 		inode_unlock(inode);
5892 	}
5893 	return err;
5894 }
5895 
5896 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5897 			     unsigned int flags)
5898 {
5899 	int err;
5900 	struct inode *qf_inode;
5901 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5902 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5903 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5904 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5905 	};
5906 
5907 	BUG_ON(!ext4_has_feature_quota(sb));
5908 
5909 	if (!qf_inums[type])
5910 		return -EPERM;
5911 
5912 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5913 	if (IS_ERR(qf_inode)) {
5914 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5915 		return PTR_ERR(qf_inode);
5916 	}
5917 
5918 	/* Don't account quota for quota files to avoid recursion */
5919 	qf_inode->i_flags |= S_NOQUOTA;
5920 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5921 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
5922 	if (err)
5923 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5924 	iput(qf_inode);
5925 
5926 	return err;
5927 }
5928 
5929 /* Enable usage tracking for all quota types. */
5930 static int ext4_enable_quotas(struct super_block *sb)
5931 {
5932 	int type, err = 0;
5933 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5934 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5935 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5936 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5937 	};
5938 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5939 		test_opt(sb, USRQUOTA),
5940 		test_opt(sb, GRPQUOTA),
5941 		test_opt(sb, PRJQUOTA),
5942 	};
5943 
5944 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5945 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5946 		if (qf_inums[type]) {
5947 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5948 				DQUOT_USAGE_ENABLED |
5949 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5950 			if (err) {
5951 				ext4_warning(sb,
5952 					"Failed to enable quota tracking "
5953 					"(type=%d, err=%d). Please run "
5954 					"e2fsck to fix.", type, err);
5955 				for (type--; type >= 0; type--)
5956 					dquot_quota_off(sb, type);
5957 
5958 				return err;
5959 			}
5960 		}
5961 	}
5962 	return 0;
5963 }
5964 
5965 static int ext4_quota_off(struct super_block *sb, int type)
5966 {
5967 	struct inode *inode = sb_dqopt(sb)->files[type];
5968 	handle_t *handle;
5969 	int err;
5970 
5971 	/* Force all delayed allocation blocks to be allocated.
5972 	 * Caller already holds s_umount sem */
5973 	if (test_opt(sb, DELALLOC))
5974 		sync_filesystem(sb);
5975 
5976 	if (!inode || !igrab(inode))
5977 		goto out;
5978 
5979 	err = dquot_quota_off(sb, type);
5980 	if (err || ext4_has_feature_quota(sb))
5981 		goto out_put;
5982 
5983 	inode_lock(inode);
5984 	/*
5985 	 * Update modification times of quota files when userspace can
5986 	 * start looking at them. If we fail, we return success anyway since
5987 	 * this is not a hard failure and quotas are already disabled.
5988 	 */
5989 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5990 	if (IS_ERR(handle))
5991 		goto out_unlock;
5992 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5993 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5994 	inode->i_mtime = inode->i_ctime = current_time(inode);
5995 	ext4_mark_inode_dirty(handle, inode);
5996 	ext4_journal_stop(handle);
5997 out_unlock:
5998 	inode_unlock(inode);
5999 out_put:
6000 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6001 	iput(inode);
6002 	return err;
6003 out:
6004 	return dquot_quota_off(sb, type);
6005 }
6006 
6007 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6008  * acquiring the locks... As quota files are never truncated and quota code
6009  * itself serializes the operations (and no one else should touch the files)
6010  * we don't have to be afraid of races */
6011 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6012 			       size_t len, loff_t off)
6013 {
6014 	struct inode *inode = sb_dqopt(sb)->files[type];
6015 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6016 	int offset = off & (sb->s_blocksize - 1);
6017 	int tocopy;
6018 	size_t toread;
6019 	struct buffer_head *bh;
6020 	loff_t i_size = i_size_read(inode);
6021 
6022 	if (off > i_size)
6023 		return 0;
6024 	if (off+len > i_size)
6025 		len = i_size-off;
6026 	toread = len;
6027 	while (toread > 0) {
6028 		tocopy = sb->s_blocksize - offset < toread ?
6029 				sb->s_blocksize - offset : toread;
6030 		bh = ext4_bread(NULL, inode, blk, 0);
6031 		if (IS_ERR(bh))
6032 			return PTR_ERR(bh);
6033 		if (!bh)	/* A hole? */
6034 			memset(data, 0, tocopy);
6035 		else
6036 			memcpy(data, bh->b_data+offset, tocopy);
6037 		brelse(bh);
6038 		offset = 0;
6039 		toread -= tocopy;
6040 		data += tocopy;
6041 		blk++;
6042 	}
6043 	return len;
6044 }
6045 
6046 /* Write to quotafile (we know the transaction is already started and has
6047  * enough credits) */
6048 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6049 				const char *data, size_t len, loff_t off)
6050 {
6051 	struct inode *inode = sb_dqopt(sb)->files[type];
6052 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6053 	int err, offset = off & (sb->s_blocksize - 1);
6054 	int retries = 0;
6055 	struct buffer_head *bh;
6056 	handle_t *handle = journal_current_handle();
6057 
6058 	if (EXT4_SB(sb)->s_journal && !handle) {
6059 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6060 			" cancelled because transaction is not started",
6061 			(unsigned long long)off, (unsigned long long)len);
6062 		return -EIO;
6063 	}
6064 	/*
6065 	 * Since we account only one data block in transaction credits,
6066 	 * then it is impossible to cross a block boundary.
6067 	 */
6068 	if (sb->s_blocksize - offset < len) {
6069 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6070 			" cancelled because not block aligned",
6071 			(unsigned long long)off, (unsigned long long)len);
6072 		return -EIO;
6073 	}
6074 
6075 	do {
6076 		bh = ext4_bread(handle, inode, blk,
6077 				EXT4_GET_BLOCKS_CREATE |
6078 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6079 	} while (PTR_ERR(bh) == -ENOSPC &&
6080 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6081 	if (IS_ERR(bh))
6082 		return PTR_ERR(bh);
6083 	if (!bh)
6084 		goto out;
6085 	BUFFER_TRACE(bh, "get write access");
6086 	err = ext4_journal_get_write_access(handle, bh);
6087 	if (err) {
6088 		brelse(bh);
6089 		return err;
6090 	}
6091 	lock_buffer(bh);
6092 	memcpy(bh->b_data+offset, data, len);
6093 	flush_dcache_page(bh->b_page);
6094 	unlock_buffer(bh);
6095 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6096 	brelse(bh);
6097 out:
6098 	if (inode->i_size < off + len) {
6099 		i_size_write(inode, off + len);
6100 		EXT4_I(inode)->i_disksize = inode->i_size;
6101 		ext4_mark_inode_dirty(handle, inode);
6102 	}
6103 	return len;
6104 }
6105 #endif
6106 
6107 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6108 		       const char *dev_name, void *data)
6109 {
6110 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6111 }
6112 
6113 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6114 static inline void register_as_ext2(void)
6115 {
6116 	int err = register_filesystem(&ext2_fs_type);
6117 	if (err)
6118 		printk(KERN_WARNING
6119 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6120 }
6121 
6122 static inline void unregister_as_ext2(void)
6123 {
6124 	unregister_filesystem(&ext2_fs_type);
6125 }
6126 
6127 static inline int ext2_feature_set_ok(struct super_block *sb)
6128 {
6129 	if (ext4_has_unknown_ext2_incompat_features(sb))
6130 		return 0;
6131 	if (sb_rdonly(sb))
6132 		return 1;
6133 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6134 		return 0;
6135 	return 1;
6136 }
6137 #else
6138 static inline void register_as_ext2(void) { }
6139 static inline void unregister_as_ext2(void) { }
6140 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6141 #endif
6142 
6143 static inline void register_as_ext3(void)
6144 {
6145 	int err = register_filesystem(&ext3_fs_type);
6146 	if (err)
6147 		printk(KERN_WARNING
6148 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6149 }
6150 
6151 static inline void unregister_as_ext3(void)
6152 {
6153 	unregister_filesystem(&ext3_fs_type);
6154 }
6155 
6156 static inline int ext3_feature_set_ok(struct super_block *sb)
6157 {
6158 	if (ext4_has_unknown_ext3_incompat_features(sb))
6159 		return 0;
6160 	if (!ext4_has_feature_journal(sb))
6161 		return 0;
6162 	if (sb_rdonly(sb))
6163 		return 1;
6164 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6165 		return 0;
6166 	return 1;
6167 }
6168 
6169 static struct file_system_type ext4_fs_type = {
6170 	.owner		= THIS_MODULE,
6171 	.name		= "ext4",
6172 	.mount		= ext4_mount,
6173 	.kill_sb	= kill_block_super,
6174 	.fs_flags	= FS_REQUIRES_DEV,
6175 };
6176 MODULE_ALIAS_FS("ext4");
6177 
6178 /* Shared across all ext4 file systems */
6179 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6180 
6181 static int __init ext4_init_fs(void)
6182 {
6183 	int i, err;
6184 
6185 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6186 	ext4_li_info = NULL;
6187 	mutex_init(&ext4_li_mtx);
6188 
6189 	/* Build-time check for flags consistency */
6190 	ext4_check_flag_values();
6191 
6192 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6193 		init_waitqueue_head(&ext4__ioend_wq[i]);
6194 
6195 	err = ext4_init_es();
6196 	if (err)
6197 		return err;
6198 
6199 	err = ext4_init_pending();
6200 	if (err)
6201 		goto out7;
6202 
6203 	err = ext4_init_post_read_processing();
6204 	if (err)
6205 		goto out6;
6206 
6207 	err = ext4_init_pageio();
6208 	if (err)
6209 		goto out5;
6210 
6211 	err = ext4_init_system_zone();
6212 	if (err)
6213 		goto out4;
6214 
6215 	err = ext4_init_sysfs();
6216 	if (err)
6217 		goto out3;
6218 
6219 	err = ext4_init_mballoc();
6220 	if (err)
6221 		goto out2;
6222 	err = init_inodecache();
6223 	if (err)
6224 		goto out1;
6225 	register_as_ext3();
6226 	register_as_ext2();
6227 	err = register_filesystem(&ext4_fs_type);
6228 	if (err)
6229 		goto out;
6230 
6231 	return 0;
6232 out:
6233 	unregister_as_ext2();
6234 	unregister_as_ext3();
6235 	destroy_inodecache();
6236 out1:
6237 	ext4_exit_mballoc();
6238 out2:
6239 	ext4_exit_sysfs();
6240 out3:
6241 	ext4_exit_system_zone();
6242 out4:
6243 	ext4_exit_pageio();
6244 out5:
6245 	ext4_exit_post_read_processing();
6246 out6:
6247 	ext4_exit_pending();
6248 out7:
6249 	ext4_exit_es();
6250 
6251 	return err;
6252 }
6253 
6254 static void __exit ext4_exit_fs(void)
6255 {
6256 	ext4_destroy_lazyinit_thread();
6257 	unregister_as_ext2();
6258 	unregister_as_ext3();
6259 	unregister_filesystem(&ext4_fs_type);
6260 	destroy_inodecache();
6261 	ext4_exit_mballoc();
6262 	ext4_exit_sysfs();
6263 	ext4_exit_system_zone();
6264 	ext4_exit_pageio();
6265 	ext4_exit_post_read_processing();
6266 	ext4_exit_es();
6267 	ext4_exit_pending();
6268 }
6269 
6270 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6271 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6272 MODULE_LICENSE("GPL");
6273 MODULE_SOFTDEP("pre: crc32c");
6274 module_init(ext4_init_fs)
6275 module_exit(ext4_exit_fs)
6276